TWI839801B - Polyisocyanate composition, cured film, adhesive resin composition, adhesive resin sheet, and laminated film - Google Patents

Abstract

The present invention provides a polyisocyanate composition, etc. The polyisocyanate composition is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and at least one polyester polyol selected from the group consisting of a difunctional polyester polyol (A) having a number average molecular weight Mn of 500 or more and a trifunctional or higher polyester polyol (B) having a number average molecular weight Mn of 500 or more, wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol is 1.5 to 30.0, and the weight average molecular weight of the polyisocyanate composition is 1400 to 800000.

Description

Polyisocyanate composition, cured film, adhesive resin composition, adhesive resin sheet, and laminated film

The present invention relates to a polyisocyanate composition, a hardened film, an adhesive resin composition, an adhesive resin sheet, and a laminate film.

In recent years, plastic films or adhesives have been used in various fields due to their wide range of functions. In this case, applications have increased not only to flat parts, but also to curved parts or parts with bending movements, which were previously less common. For example, the bonding of flexible displays or foldable displays, automotive components, etc. has seen a rapid increase in demand in recent years. As a result, for curved surfaces or bends, highly flexible films or adhesives with good tracking, stretchability, and bending resistance and strong toughness are required. In addition, for optical uses, higher transparency is also required, specifically a haze value of 3.0% or less.

For example, Patent Document 1 discloses a method for producing a prepolymer for polyurethane coating having stretchability, which method comprises reacting an aliphatic diisocyanate or alicyclic diisocyanate with a polycaprolactone diol and/or triol having a number average molecular weight of 500 to 1500. In addition, Patent Document 2 discloses a mixture, which is a mixture of a prepolymer obtained by reacting an aliphatic diisocyanate or alicyclic diisocyanate with a polytetramethylene glycol having a number average molecular weight of 700 to 1500, and a prepolymer obtained by reacting an aliphatic diisocyanate or alicyclic diisocyanate with a polycaprolactone polyol having a number average molecular weight of 500 to 1500.

[Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent Publication No. 61-028518

[Patent document 2] Japanese Patent Publication No. 02-001718

However, the softness of the polyisocyanate modified by polyester polyol or polyether polyol described in Patent Document 1 or Patent Document 2 etc. has room for improvement. Moreover, in these documents, the research is limited to the use in coatings, and no specific research is conducted on the application in adhesives. Furthermore, no attention is paid to the correlation between the structure and transparency of polyisocyanate.

The present invention is made in view of the above situation, and provides a polyisocyanate composition, which can obtain a cured film formed by curing the polyisocyanate composition alone, which has good flexibility and transparency, and excellent elongation and tensile fracture stress, as well as an adhesive resin composition and an adhesive resin sheet with excellent adhesion, curability and transparency. In addition, the present invention provides a laminated film having the above-mentioned adhesive resin sheet.

That is, the present invention includes the following forms.

(1) A polyisocyanate composition, which is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and at least one polyester polyol selected from the group consisting of a difunctional polyester polyol (A) having a number average molecular weight Mn of 500 or more and a trifunctional or higher polyester polyol (B) having a number average molecular weight Mn of 500 or more, wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol is 1.5 or more and 30.0 or less, and the weight average molecular weight of the polyisocyanate composition is 1400 or more and 800000 or less.

(2) The polyisocyanate composition as described in (1), wherein the average number of isocyanate functional groups of the polyisocyanate composition is greater than 2.0 and less than 6.0.

(3) The polyisocyanate composition as described in (1) or (2), wherein the isocyanate group content of the polyisocyanate composition is not less than 1.0 mass % and not more than 8.7 mass %.

(4) A polyisocyanate composition as described in any one of (1) to (3), wherein the content of the polyester polyol (A) is 0.1 to 900 parts by mass relative to 100 parts by mass of the diisocyanate, and the content of the polyester polyol (B) is 0.1 to 900 parts by mass relative to 100 parts by mass of the diisocyanate.

(5) A polyisocyanate composition as described in any one of (1) to (4), wherein the polyester polyol is a polycaprolactone polyol.

(6) The polyisocyanate composition described in any one of (1) to (5), when applied on glass and stored at 23°C and 65% humidity for 168 hours, forms a cured film with a thickness of 40 μm and a König hardness of 60 times or less at 23°C.

(7) The polyisocyanate composition described in (6), wherein the haze value measured by a haze meter when the cured film having a film thickness of 40 μm is attached to a glass having a haze value of 0.1% is 3.0% or less.

(8) A cured film comprising a polyisocyanate composition as described in any one of (1) to (5) and a resin composition of a polyol having a glass transition temperature of 0°C to 100°C, wherein the elongation in a tensile test measured at a speed of 20 mm/min is 140% or more, the stress at 140% is 25.0 MPa or less, and the tensile fracture stress is 1.2 times or more of the stress at 140% above the elongation.

(9) A cured film as described in (8), wherein the content of the polyisocyanate composition is not less than 0.01 parts by mass and not more than 200 parts by mass relative to 100 parts by mass of the polyol.

(10) An adhesive resin composition comprising a polyisocyanate composition as described in any one of (1) to (7), and a polymer containing a crosslinking functional group having a glass transition temperature of 0.0°C or less.

(11) The adhesive resin composition described in (10), wherein the polymer containing the cross-linking functional group is an acrylic polymer or a urethane polymer.

(12) The adhesive resin composition as described in (10) or (11), wherein the polymer containing a crosslinking functional group is obtained by copolymerizing a polymerizable (meth) acrylic monomer having a crosslinking functional group and a (meth) acrylic ester monomer having a carbon number of 1 to 18 at the end of the ester group, and the glass transition temperature Tg is between -75.0°C and 0.0°C.

(13) The adhesive resin composition as described in any one of (10) to (12), wherein the weight average molecular weight of the polymer containing a crosslinking functional group is 1.0×10 ⁵ or more and 5.0×10 ⁶ or less.

(14) The adhesive resin composition as described in any one of (10) to (13), wherein the cross-linking functional group is selected from at least one of the group consisting of hydroxyl, epoxy, cyclobutyl, carboxyl, vinyl, and amino.

(15) An adhesive resin composition as described in any one of (10) to (14), wherein the content of the polyisocyanate composition is not less than 0.01 parts by mass and not more than 20.00 parts by mass relative to 100 parts by mass of the polymer containing crosslinking functional groups.

(16) An adhesive resin sheet, which is obtained by hardening the adhesive resin composition described in any one of (10) to (15) by heat or light.

(17) The adhesive resin sheet as described in (16), wherein the thickness of the adhesive resin sheet is greater than 1 μm and less than 1000 μm.

(18) The adhesive resin sheet described in (16) or (17), wherein the gel fraction is not less than 20.0 mass % and not more than 99.9 mass %.

(19) The adhesive resin sheet described in any one of (16) to (18), wherein the 180-degree peeling adhesion measured at 23°C and a speed of 300 mm/min is 0.05 N/20 mm or more and 65.00 N/20 mm or less.

(20) An adhesive resin sheet as described in any one of (16) to (19), wherein the adhesive resin sheet having a thickness of 50 μm is attached to a glass having a haze value of 0.1% and the haze value measured by a haze meter is less than 2.0%.

(21) A laminated film, which is a film substrate laminated on at least one surface of the adhesive resin sheet described in any one of (16) to (20).

(22) A laminate film as described in (21), wherein the film substrate is at least one selected from the group consisting of polyester resins, acetate resins, polyether sulfide resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and triacetylcellulose resins.

(23) A multilayer film as described in (21) or (22), wherein the multilayer film is used for optical purposes.

According to the polyisocyanate composition of the above-mentioned form, a polyisocyanate composition can be provided, which can obtain a cured film formed by curing the polyisocyanate composition alone, which has good flexibility and transparency, and excellent elongation and tensile fracture stress, as well as an adhesive resin composition and an adhesive resin sheet with excellent adhesion, curability and transparency. In addition, the present invention can provide a laminated film having the above-mentioned adhesive resin sheet.

Furthermore, in this specification, "polyol" means a compound having two or more hydroxyl groups (-OH) in one molecule.

In addition, in this specification, "polyisocyanate" means a reaction product obtained by combining multiple monomer compounds having two or more isocyanate groups (-NCO).

In addition, in this specification, unless otherwise specified, "(meth)acrylic acid" includes methacrylic acid and acrylic acid, and "(meth)acrylate" includes methacrylate and acrylate.

《Polyisocyanate composition》

The polyisocyanate composition of the present embodiment is derived from a diisocyanate and at least one polyester polyol selected from the group consisting of a bifunctional polyester polyol (A) having a number average molecular weight of 500 or more (hereinafter referred to as "polyester polyol (A)") and a trifunctional or higher polyester polyol (B) having a number average molecular weight Mn of 500 or more (hereinafter referred to as "polyester polyol (B)"). That is, the polyisocyanate composition of the present embodiment is a reaction product of a diisocyanate and one or more of the above polyester polyols, including a polyisocyanate modified by one or more of the above polyester polyols. The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

In the polyisocyanate composition of the present embodiment, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol (A) and/or the polyester polyol (B) (molar ratio of isocyanate group/hydroxyl group) is 1.5 to 30.0, preferably 2.0 to 25.0, more preferably 2.1 to 23.0, further preferably 2.2 to 20.0, further preferably 2.3 to 20.0, further preferably 2.4 to 20.0, particularly preferably 2.5 to 20.0, and most preferably 2.52 to 20.0.

The molar ratio of isocyanate group/hydroxyl group can be calculated, for example, using the molar amount of hydroxyl group of polyester polyol (A) and/or polyester polyol (B) used in the preparation of the polyisocyanate composition and the molar amount of isocyanate group of diisocyanate.

The weight average molecular weight of the polyisocyanate composition of this embodiment is 1400 or more, preferably 1500 or more, more preferably 2000 or more, further preferably 2500 or more, and particularly preferably 3000 or more.

The upper limit of the weight average molecular weight of the polyisocyanate composition of this embodiment is not particularly limited and can be set to 800,000.

The weight average molecular weight of the polyisocyanate composition of this embodiment can be measured, for example, by gel permeation chromatography (hereinafter sometimes abbreviated as "GPC").

Since the polyisocyanate composition of this embodiment has the above-mentioned structure, the hardness of the cured film formed by curing the polyisocyanate composition alone is lower than before, and the softness and transparency are good. In addition, by using the polyisocyanate composition of this embodiment, a cured film with a stress lower than before at an elongation of 140%, a higher elongation than before, and a higher tensile fracture stress than before can be obtained. Furthermore, by using the polyisocyanate composition of this embodiment, an adhesive resin sheet with excellent adhesion, curability and transparency can be obtained.

Next, the components of the polyisocyanate composition of this embodiment are described in detail below.

<Polyisocyanate>

Polyisocyanate is a compound that contains structural units derived from diisocyanate and one or more of the above-mentioned polyester polyols in one molecule.

When the polyisocyanate composition of the present embodiment is derived from diisocyanate and polyester polyol (A) and polyester polyol (B), it may be a polyisocyanate having all structural units derived from diisocyanate and polyester polyol (A) and polyester polyol (B) in one molecule, or a mixture of a polyisocyanate having structural units derived from diisocyanate and polyester polyol (A) in one molecule and a polyisocyanate having structural units derived from diisocyanate and polyester polyol (B) in one molecule.

二

二酮結構、異氰尿酸酯結構、尿素結構、胺基甲酸酯結構、及縮二脲結 構所組成之群中之至少1種以上之結構。其中，較佳為具有選自由胺基甲酸酯結構、脲基甲酸酯結構、縮二脲結構、尿素結構、脲二酮結構、及異氰尿酸酯結構所組成之群中之至少1種結構，更佳為具有選自由胺基甲酸酯結構、脲基甲酸酯結構、縮二脲結構、尿素結構、及脲二酮結構所組成之群中之至少1種結構，進而較佳為具有選自由胺基甲酸酯結構、脲基甲酸酯結構、尿素結構、及脲二酮結構所組成之群中之至少1種結構，進而較佳為具有選自由胺基甲酸酯結構、脲基甲酸酯結構、及脲二酮結構所組成之群中之至少1種結構，進而較佳為具有選自由胺基甲酸酯結構、脲基甲酸酯結構所組成之群中之至少1種結構，尤佳為具有胺基甲酸酯結構。 The polyisocyanate has an allophanate structure, a uretdione structure, an imine structure,

two

The present invention relates to a hydroxyl group-containing ester having at least one structure selected from the group consisting of a diketone structure, an isocyanurate structure, a urea structure, a carbamate structure, and a biuret structure. Among them, it is preferred to have at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, a biuret structure, a urea structure, a uretdione structure, and an isocyanurate structure, and it is more preferred to have at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, a biuret structure, a urea structure, and a uretdione structure, and it is further preferred to have at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, a biuret structure, a urea structure, and a uretdione structure. The present invention further preferably has at least one structure selected from the group consisting of an ester structure, an allophanate structure, a urea structure, and a uretdione structure, and further preferably has at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, and a uretdione structure, and further preferably has at least one structure selected from the group consisting of a carbamate structure and an allophanate structure, and particularly preferably has a carbamate structure.

[Diisocyanate]

The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

Examples of aliphatic diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, (2,6-diisocyanato)hexanoic acid ethyl ester, 1,6-diisocyanatohexane (hereinafter sometimes referred to as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, etc., but are not limited thereto. These aliphatic diisocyanates may be used alone or in combination of two or more.

烷等，但並未限定於以上。可單獨使用1種該等脂環族二異氰酸酯，亦可將2種以上該等脂環族二異氰酸酯組合使用。 Examples of the alicyclic diisocyanate include 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter, sometimes referred to as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl-1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter, sometimes referred to as "IPDI"), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter, sometimes referred to as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylcyclohexane.

Such alicyclic diisocyanates may be used alone or in combination of two or more.

Any of the aliphatic diisocyanates and alicyclic diisocyanates may be used alone, or two or more aliphatic diisocyanates and alicyclic diisocyanates may be used in combination.

In addition, from the perspective of softness, the mass ratio of alicyclic diisocyanate to aliphatic diisocyanate is preferably 0/100 or more and 30/70 or less.

Among them, as the diisocyanate, 1,4-diisocyanatobutane, HDI, 1,5-pentamethylene diisocyanate (PDI), 1,7-diisocyanatoheptane, 1,8-diisocyanatooctane, IPDI, hydrogenated XDI, or hydrogenated MDI is preferred, HDI, PDI, or IPDI is more preferred, HDI or PDI is further preferred, and HDI is particularly preferred.

In the production of polyisocyanates, in addition to the above-mentioned diisocyanates, the following isocyanate monomers can be used.

(1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), xylylene diisocyanate (XDI), and m-tetramethylxylene diisocyanate (TMXDI).

(2) Triisocyanates such as 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter sometimes referred to as "NTI"), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as "HTI"), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter sometimes referred to as "GTI"), and lysine triisocyanate (hereinafter sometimes referred to as "LTI").

[Polyester polyol (A) and polyester polyol (B)]

Polyester polyol (A) is a bifunctional polyester polyol (diol) with a molecular weight of 500 or more.

Polyester polyol (B) is a trifunctional or higher polyester polyol with a number average molecular weight of 500 or more.

The number average molecular weight of the polyester polyol (A) is 500 or more, preferably 800 or more, more preferably 1500 or more, and further preferably 1800 or more. By making the number average molecular weight of the polyester polyol (A) above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is lower and the softness is good.

On the other hand, the upper limit of the number average molecular weight of the polyester polyol (A) is not particularly limited, and can be, for example, 12,000, 10,000, 8,000, 7,000, preferably 6,000, more preferably 5,000, and even more preferably 4,500.

The number average molecular weight Mn of the polyester polyol (A) is, for example, the number average molecular weight based on polystyrene obtained by GPC measurement. In addition, when two or more polyester polyols (A) are mixed for use, the number average molecular weight of the mixture is calculated and used.

The number average molecular weight of the polyester polyol (B) is 500 or more, preferably 800 or more. By making the number average molecular weight of the polyester polyol (B) above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is lower and the softness is good.

On the other hand, the upper limit of the number average molecular weight of the polyester polyol (B) is not particularly limited, and can be, for example, 12,000, 10,000, 8,000, 6,000, 4,000, preferably 3,500, more preferably 3,000, and even more preferably 2,500.

The number average molecular weight Mn of the polyester polyol (B) is, for example, the number average molecular weight based on polystyrene obtained by GPC measurement. In addition, when two or more polyester polyols (B) are mixed for use, the number average molecular weight of the mixture is calculated and used.

As polyester polyol (A), for example, any one of the following polyester polyols (1) or (2) can be cited.

(1) Polyester polyols obtained by the condensation reaction of a single dibasic acid or a mixture of two or more dibasic acids with a single diol or a mixture of two or more diols.

(2) Polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with diols.

Examples of the above-mentioned dibasic acid include succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid and other carboxylic acids.

Examples of the above-mentioned diols include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, etc.

Among them, as polyester polyol (A), difunctional polycaprolactone polyol is preferred.

Examples of commercially available bifunctional polycaprolactone polyols include "PLACCEL 210" (number average molecular weight 1000, hydroxyl value 112.8 mgKOH/g, acid value 0.09 mgKOH/g), "PLACCEL 210CP" (number average molecular weight 1000, hydroxyl value 112.8 mgKOH/g, acid value 0.16 mgKOH/g), "PLACCEL 212" (number average molecular weight 1250, hydroxyl value 90.8 mgKOH/g, acid value 0.09 mgKOH/g), "PLACCEL 212CP" (number average molecular weight 1250, hydroxyl value 90.2 mgKOH/g, acid value 0.14 mgKOH/g), "PLACCEL "PLACCEL 220" (number average molecular weight 2000, hydroxyl value 56.7mgKOH/g, acid value 0.06mgKOH/g), "PLACCEL 220CPB" (number average molecular weight 2000, hydroxyl value 57.2mgKOH/g, acid value 0.16mgKOH/g), "PLACCEL 220CPT" (number average molecular weight 2000, hydroxyl value 56.6mgKOH/g, acid value 0.02mgKOH/g), "PLACCEL 230" (number average molecular weight 3000, hydroxyl value 37.6mgKOH/g, acid value 0.07mgKOH/g), "PLACCEL 240 (number average molecular weight 4000, hydroxyl value 28.5mgKOH/g, acid value 0.07mgKOH/g), etc.

As a difunctional polycaprolactone polyol, from the perspective of hydrolysis resistance and reaction stability during polyisocyanate synthesis, it is better to use one with a lower acid value.

As the polyester polyol (B), a polyester polyol having three or more functional groups may be used, preferably a polyester polyol having three or more functional groups but less than ten functional groups, more preferably a polyester polyol having three or more functional groups but less than seven functional groups, further preferably a polyester polyol having three or more functional groups but less than five functional groups, particularly preferably a polyester polyol having three or more functional groups but less than four functional groups, and most preferably a trifunctional polyester polyol (triol).

As the trifunctional polyester polyol (B), for example, any one of the following polyester polyols (1) or (2) can be cited.

(1) Polyester polyols obtained by the condensation reaction of a single dibasic acid or a mixture of two or more dibasic acids with a single triol or a mixture of two or more triols.

(2) Polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with triols.

Examples of the above-mentioned dibasic acid include succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid and other carboxylic acids.

Examples of the above-mentioned triols include trihydroxymethylpropane, glycerin, pentaerythritol, 2-hydroxymethylpropanediol, and ethoxylated trihydroxymethylpropane.

Among them, as the trifunctional polyester polyol (B), trifunctional polycaprolactone polyol is preferred.

Examples of commercially available trifunctional polycaprolactone polyols include "PLACCEL 305" (number average molecular weight 550, hydroxyl value 305.6 mgKOH/g, acid value 0.50 mgKOH/g), "PLACCEL 308" (number average molecular weight 850, hydroxyl value 195.3 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 309" (number average molecular weight 900, hydroxyl value 187.3 mgKOH/g, acid value 0.20 mgKOH/g), "PLACCEL 312" (number average molecular weight 1250, hydroxyl value 136.1 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 313" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 314" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 315" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 316" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 317" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 318" (number average molecular weight 1500, hydroxyl value 140.6 mgKOH/g, acid value 0.38 mgKOH/g), "PLACCEL 319 320" (number average molecular weight 2000, hydroxyl value 85.4mgKOH/g, acid value 0.29mgKOH/g), etc.

In the polyisocyanate composition of the present embodiment, the content (addition amount) of the polyester polyol (A) is preferably 0.1 to 900 parts by mass, more preferably 0.5 to 800 parts by mass, more preferably 1 to 700 parts by mass, and more preferably 1 to 600 parts by mass, relative to 100 parts by mass of diisocyanate.

By making the content of polyester polyol (A) above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is lower and the flexibility is better. In addition, an adhesive resin sheet with better adhesion and curability can be obtained. On the other hand, by making the content of polyester polyol (A) below the above upper limit, the polyisocyanate composition can be made without gelling and maintained in a liquid state, the elongation and breaking strength are higher, and the flexibility of the adhesive resin sheet is better.

The content of polyester polyol (A) can be calculated, for example, from the amounts of diisocyanate and polyester polyol (A) formulated during the production of the polyisocyanate composition, and the yield of the obtained polyisocyanate composition.

In the polyisocyanate composition of the present embodiment, the content (addition amount) of the polyester polyol (B) is preferably 0.1 to 900 parts by mass, more preferably 0.5 to 800 parts by mass, more preferably 1 to 700 parts by mass, and more preferably 1 to 600 parts by mass, relative to 100 parts by mass of diisocyanate.

By making the content of polyester polyol (B) above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is lower and the flexibility is better. In addition, an adhesive resin sheet with better adhesion and curability can be obtained. On the other hand, by making the content of polyester polyol (B) below the above upper limit, the polyisocyanate composition can be made without gelling and maintained in a liquid state, and the adhesive resin sheet can be made with better flexibility.

The content of polyester polyol (B) can be calculated, for example, from the amounts of diisocyanate and polyester polyol (B) formulated during the production of the polyisocyanate composition, and the yield of the obtained polyisocyanate composition.

<Method for producing polyisocyanate composition>

The polyisocyanate is obtained by reacting the above-mentioned diisocyanate with one or more polyester polyols selected from the group consisting of polyester polyols (A) and polyester polyols (B). In the following, polyester polyols (A) and polyester polyols (B) may be collectively referred to as polyester polyols.

When polyester polyol (A) and polyester polyol (B) are used in combination, polyester polyol (A) and polyester polyol (B) may be used separately or in the form of a mixture. When used in the form of a mixture, they may be mixed before reacting with diisocyanate, or after reacting each polyester polyol with diisocyanate to prepare polyisocyanate.

That is, as a method for producing a polyisocyanate composition, for example, the following methods can be cited: reacting diisocyanate, polyester polyol (A) and polyester polyol (B) simultaneously to obtain a polyisocyanate composition; mixing the product obtained by reacting diisocyanate with polyester polyol (A) and the product obtained by reacting diisocyanate with polyester polyol (B) to obtain a polyisocyanate composition; reacting diisocyanate with polyester polyol (A) or polyester polyol (B), and then further reacting the remaining polyester polyol to obtain a polyisocyanate composition.

During the reaction, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol (A) and the polyester polyol (B) (molar ratio of isocyanate group/hydroxyl group) is 1.5 to 30, preferably 2.0 to 25, more preferably 2.1 to 23, further preferably 2.2 to 20, further preferably 2.3 to 20.0, further preferably 2.4 to 20.0, further preferably 2.5 to 20.0, and most preferably 2.52 to 20.0.

The reaction of polyester polyol and diisocyanate is carried out as follows. The reaction temperature is usually above room temperature (about 23°C) and below 200°C, preferably above 60°C and below 180°C, and preferably above 60°C and below 170°C. If the reaction temperature is above the lower limit, the reaction time becomes shorter. On the other hand, if the reaction temperature is below the upper limit, the undesirable viscosity increase and gelation of the polyisocyanate caused by the side reaction can be further avoided, and the coloring of the generated polyisocyanate can also be further avoided.

The reaction can be carried out in the absence of a solvent, or using any solvent inert to isocyanate groups. In addition, in order to promote the reaction between isocyanate groups and hydroxyl groups, a known catalyst can be used as needed.

<Physical properties of polyisocyanate composition>

The isocyanate group content (NCO group content) of the polyisocyanate composition of the present embodiment is preferably 1.0 mass% to 8.7 mass% relative to the total mass of the polyisocyanate composition in a state where the solvent or diisocyanate is substantially not included, more preferably 1.5 mass% to 8.6 mass%, further preferably 2.0 mass% to 8.5 mass%, further preferably 2.5 mass% to 8.5 mass%, further preferably 2.7 mass% to 8.5 mass%, and particularly preferably 2.9 mass% to 8.5 mass%.

The NCO group content can be determined, for example, by reacting the isocyanate group of the polyisocyanate composition with an excess of amine (such as dibutylamine) and back-titrating the remaining amine with an acid such as hydrochloric acid.

The average isocyanate functional group number of the polyisocyanate composition of this embodiment is preferably 2.0 to 6.0, and more preferably 2.1 to 5.9, in order to improve the curability and flexibility of the adhesive resin composition.

The average isocyanate functional group number of the polyisocyanate composition of this embodiment can be measured using the method described in the following embodiment.

When the polyisocyanate composition of this embodiment is diluted with a solvent such as butyl acetate or ethyl acetate, it is preferably a liquid at 23°C from the perspective of handling such as formulation.

《Hardening Film 1》

The cured film 1 of this embodiment is formed by curing the above-mentioned polyisocyanate composition alone.

The hardness of the cured film 1 of this embodiment is relatively low, and its softness and transparency are good.

The cured film 1 of this embodiment can be manufactured, for example, by diluting or dissolving the above-mentioned polyisocyanate composition with a solvent as needed, applying it to the adherend using a coating machine, drying it as needed, and curing it by heat.

In the case where the cured film 1 of the present embodiment is a cured film with a thickness of 40 μm formed by the reaction of the moisture in the air with the polyisocyanate composition after the polyisocyanate composition is applied to the glass and stored in an environment of 23°C and 65% humidity for 168 hours, the Koenig hardness of the cured film in an environment of 23°C is 60 times or less, preferably 59 times or less, and more preferably 58 times or less. By making the Koenig hardness below the above upper limit, the hardness is lower and the softness is better. On the other hand, the lower limit of the Koenig hardness of the cured film is not particularly limited, for example, it can be set to 3 times, 4 times, or 5 times.

In the case where the cured film 1 of the present embodiment is a cured film with a thickness of 40 μm formed by the reaction of the moisture in the air with the polyisocyanate composition after the polyisocyanate composition is applied to the glass and stored in an environment of 23°C and 65% humidity for 168 hours, the haze value measured by a haze meter when the cured film is attached to a glass with a haze value of 0.1% is preferably 3.0% or less, more preferably 2.9% or less, and further preferably 2.8% or less. By making the haze value of the cured film below the upper limit, the transparency is better. On the other hand, the lower limit of the haze value of the cured film is not particularly limited, and the closer to 0.0%, the better, for example, it can be set to 0.0% or 0.05%.

《Hard Film 2》

The polyisocyanate composition can also be used as a curing agent component of the resin composition. That is, the cured film 2 of the present embodiment is formed by curing a resin composition comprising the polyisocyanate composition and a polyol (preferably an acrylic polyol). The cured film 2 can function as an adhesive layer, for example.

In the above resin composition, relative to 100 parts by mass of the polyol, the content of the above polyisocyanate composition is preferably 0.01 parts by mass to 200 parts by mass, more preferably 0.05 parts by mass to 190 parts by mass, and further preferably 0.10 parts by mass to 180 parts by mass.

In the above resin composition, the molar ratio NCO/OH of the isocyanate group of the polyisocyanate composition relative to the hydroxyl group of the polyol can be determined according to the desired physical properties of the resin film, and is usually above 0.01 and below 50.

In the case where the cured film 2 of the present embodiment is a cured film having a thickness of 40 μm formed by curing the resin composition at 90° C. for 30 minutes and storing it at 23° C. and 65% humidity for 168 hours, it is preferred that the elongation in the tensile test measured at a speed of 20 mm/min by placing the test piece in a tensile tester with a clamp distance of 20 mm is 140% or more, the stress at the elongation of 140% is 25.0 MPa or less, and the tensile fracture is 100% or more. The cracking stress is 1.2 times or more of the stress when the elongation is 140%, the resin composition comprises the polyisocyanate composition and the polyol in such a manner that the molar ratio NCO/OH of the isocyanate group of the polyisocyanate composition to the hydroxyl group of the polyol is 1, the glass transition temperature of the polyol is 0° C. to 100° C., the hydroxyl value is 10 mgKOH/g to 400 mgKOH/g, and the weight average molecular weight is 5.0×10 ³ to 2.0×10 ⁵ , and the test piece is obtained by cutting the cured film into a piece with a width of 10 mm and a length of 100 mm.

Furthermore, the above elongation is preferably 140% or more, more preferably 145% or more, further preferably 150% or more, particularly preferably 155% or more, and most preferably 160% or more. On the other hand, the upper limit of the above elongation can be set to 5000%, for example.

Furthermore, the stress when the elongation is 140% is preferably 25.0 MPa or less, more preferably 24.0 MPa or less, and further preferably 23.0 MPa or less. On the other hand, the lower limit of the stress when the elongation is 140% can be set to 0.01 MPa, for example.

Furthermore, the tensile fracture stress is preferably 1.2 times or more of the stress at the above elongation of 140%, more preferably 1.3 times or more, further preferably 1.4 times or more, further preferably 1.5 times or more, further preferably 1.6 times, and particularly preferably 1.7 times. On the other hand, the upper limit of the ratio of the tensile fracture stress to the stress at the above elongation of 140% can be set to 30 times, for example.

By making the elongation above the lower limit value or more, making the stress at the elongation of 140% below the upper limit value, and making the ratio of the tensile fracture stress to the stress at the elongation of 140% above the lower limit value, the cured film 2 has better tracking performance, flexibility, bending resistance, impact resistance, and durability to the adherend.

《Adhesive resin composition》

The adhesive resin composition of this embodiment includes the above-mentioned polyisocyanate composition and a polymer containing cross-linking functional groups with a glass transition temperature of 0.0°C or less.

The adhesive resin composition of this embodiment includes the above-mentioned polyisocyanate composition, which can form an adhesive layer with higher flexibility than the previous adhesive layer, and can obtain an adhesive resin sheet with excellent adhesion, retention, curability, transparency, bending resistance, step tracking, impact resistance, and durability.

Next, the various components contained in the adhesive resin composition of this embodiment are described in detail below.

<Polymers containing cross-linking functional groups>

The glass transition temperature of the polymer containing a crosslinking functional group is below 0.0°C, preferably -75.0°C to 0.0°C, more preferably -75.0°C to -5.0°C, further preferably -75.0°C to -7.0°C, and particularly preferably -75.0°C to -10.0°C. By making the glass transition temperature Tg of the polymer containing a crosslinking functional group within the above range, the adhesive resin composition tends to have a better adhesion. The glass transition temperature of a polymer containing a crosslinking functional group can be, for example, the following value, which is obtained by dispersing an organic solvent and water in a solution containing a polymer containing a crosslinking functional group under reduced pressure and then vacuum drying the solution, using a differential scanning calorimetry (DSC) measuring device at a temperature increase rate of 5°C/min.

The weight average molecular weight Mw of the polymer containing a crosslinking functional group is preferably 1.0×10 ⁵ to 5.0×10 ⁶ , more preferably 1.5×10 ⁵ to 4.0×10 ⁶ , further preferably 2.0×10 ⁵ to 3.0×10 ⁶ , and particularly preferably 2.5×10 ⁵ to 2.5×10 ^6. By making the weight average molecular weight of the polymer containing a crosslinking functional group within the above range, the adhesion, retention, flexibility, bending resistance, step tracking, impact resistance, and durability of the cured product of the adhesive resin composition tend to become better. The weight average molecular weight Mw of the polyol can be measured, for example, by the method described in the following examples.

As a polymer containing a crosslinking functional group, it is sufficient to be a polymer containing a crosslinking functional group that can react with the isocyanate group of the above-mentioned polyisocyanate composition. As a crosslinking functional group, for example, a hydroxyl group, a thiol group, an amino group, an epoxy group, an oxycyclobutyl group, a carboxyl group, a vinyl group, an amino group, etc. can be cited, among which a hydroxyl group, an epoxy group, a carboxyl group, a vinyl group, or an amino group is preferred, a hydroxyl group, an epoxy group, an oxycyclobutyl group, a carboxyl group, or an amino group is more preferred, a hydroxyl group, a carboxyl group, an amino group is further preferred, and a hydroxyl group is particularly preferred. That is, as a polymer containing a crosslinking functional group, a polyol is preferred.

Specific examples of polymers containing crosslinking functional groups include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, epoxy resins, fluorine-containing polyols, acrylic polymers, and urethane polymers.

Among them, the polymer containing a cross-linking functional group is preferably an acrylic polymer or a urethane polymer.

[Aliphatic polyols]

Examples of the above-mentioned aliphatic hydrocarbon polyols include terminal hydroxylated polybutadiene or its hydrogenated product.

[Polyether polyol]

As the above-mentioned polyether polyol, for example, one obtained by any of the following methods (1) to (3) can be cited.

(1) Polyether polyol or polytetramethylene ether glycol obtained by adding a single alkylene oxide or a mixture of alkylene oxides to a single polyol or a mixture of polyols.

(2) Polyether polyols obtained by reacting multifunctional compounds with alkylene oxides.

(3) The so-called polymer polyol obtained by polymerizing acrylamide etc. using the polyether polyol obtained in (1) or (2) as a medium.

Examples of the above-mentioned polyols include glycerin and propylene glycol.

Examples of the above-mentioned alkylene oxides include ethylene oxide, propylene oxide, etc.

Examples of the above-mentioned multifunctional compounds include ethylenediamine, ethanolamine, etc.

[Polyester polyol]

As the above-mentioned polyester polyol, for example, any one of the following (1) or (2) polyester polyols can be cited.

(1) A polyester polyol resin obtained by the condensation reaction of a single dibasic acid or a mixture of two or more dibasic acids with a single polyol or a mixture of two or more polyols.

(2) Polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone with polyol.

Examples of the above-mentioned dibasic acid include succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid and other carboxylic acids.

Examples of the above-mentioned polyols include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trihydroxymethylpropane, glycerin, pentaerythritol, 2-hydroxymethylpropanediol, and ethoxylated trihydroxymethylpropane.

[Epoxy resin]

Examples of the epoxy resin include novolac epoxy resin, β-methyl epichlorohydrin epoxy resin, epoxy ethylene oxide type epoxy resin, glycidyl ether epoxy resin, glycol ether epoxy resin, epoxy aliphatic unsaturated compound, epoxidized fatty acid ester, ester polycarboxylic acid, amino glycidyl epoxy resin, halogenated epoxy resin, resorcinol epoxy resin, and epoxy resins obtained by modifying the epoxy resins with amino compounds, polyamide compounds, and the like.

[Fluorinated polyols]

As the above-mentioned fluorine-containing polyol, for example, there can be cited copolymers of fluoroolefins, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl esters, etc. disclosed in Reference 1 (Japanese Patent Publication No. 57-34107), Reference 2 (Japanese Patent Publication No. 61-275311), etc.

[Acrylic polymer]

The acrylic polymer contains one or more polymerizable (meth) acrylic monomer units having a cross-linking functional group. As the cross-linking functional group, it is preferred to contain a hydroxyl group, a carboxyl group, an epoxy group, or a vinyl group, more preferably a hydroxyl group or a carboxyl group, and further preferably a hydroxyl group.

The acrylic polymer may contain a crosslinking functional group alone or in combination of two or more different types of crosslinking functional groups. That is, the acrylic polymer may be obtained by polymerizing a polymerizable (meth) acrylic monomer having a crosslinking functional group alone or by copolymerizing two or more polymerizable (meth) acrylic monomers having different types of crosslinking functional groups in combination.

In addition to the polymerizable (meth)acrylic monomer units having a cross-linking functional group, the acrylic polymer may contain one or more polymerizable (meth)acrylic monomer units not having a cross-linking functional group.

That is, the acrylic polymer is obtained by polymerizing one or more polymerizable (meth) acrylic monomers having a crosslinking functional group, or by copolymerizing one or more polymerizable (meth) acrylic monomers having a crosslinking functional group with one or more polymerizable (meth) acrylic monomers not having a crosslinking functional group.

The acrylic polymer preferably contains, in addition to the polymerizable (meth) acrylic monomer unit having a cross-linking functional group, one or more (meth) acrylic ester monomer units having a carbon number of 1 to 18 at the end of the ester group.

That is, the acrylic polymer may be obtained by copolymerizing one or more polymerizable (meth) acrylic monomers having a crosslinking functional group and one or more (meth) acrylic ester monomers having a carbon number of 1 to 18 at the end of the ester group. The (meth) acrylic ester monomer may or may not have a crosslinking functional group, preferably not having a crosslinking functional group.

The number of carbon atoms at the end of the ester group of the (meth)acrylate monomer is preferably 1 or more and 18 or less.

As the above-mentioned polymerizable (meth) acrylic monomers having crosslinking functional groups, for example, those shown in (i) to (v) below can be cited. These can be used alone or in combination of two or more.

(i) Acrylic acid esters having a hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, and 8-hydroxyoctyl acrylate.

(ii) Methacrylates having a hydroxyl group such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, and 8-hydroxyoctyl methacrylate.

(iii) (Meth)acrylates with polyhydroxyl groups, such as glycerol monoacrylate or methacrylate, trihydroxymethylpropane monoacrylate or methacrylate.

(iv) Unsaturated carboxylic acids such as acrylic acid and methacrylic acid.

(v) (Meth)acrylates with epoxy groups such as glycidyl methacrylate.

Examples of the (meth)acrylate monomer having a carbon number of 1 to 18 at the end of the ester group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, and octyl (meth)acrylate. (Meth)acrylates such as isononyl acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, benzyl (meth)acrylate, and cyclohexyl (meth)acrylate. These may be used alone or in combination of two or more.

In addition to the polymerizable (meth)acrylic monomer units having cross-linking functional groups, the acrylic polymer may further include other monomer units other than the above-mentioned (meth)acrylate monomers.

That is, the acrylic polymer is obtained by polymerizing one or more polymerizable (meth) acrylic monomers having a crosslinking functional group, or by copolymerizing one or more polymerizable (meth) acrylic monomers having a crosslinking functional group with one or more other monomers. The other monomers may or may not have a crosslinking functional group, preferably not having a crosslinking functional group.

As other monomers, for example, those shown in the following (i) to (ii) can be cited. These can be used alone or in combination of two or more.

(i) Unsaturated amides such as (methyl)acrylamide, N-hydroxymethylacrylamide, diacetoneacrylamide, dimethylaminopropylacrylamide, etc.

啉、(甲基)丙烯酸二甲胺基乙酯、(甲基)丙烯酸二乙胺基乙酯。 (ii) Styrene, vinyl toluene, vinyl acetate, (meth)acrylonitrile, N-vinyl pyrrolidone, N-vinyl caprolactam, acrylamide

phenoxyethylene, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate.

Furthermore, as other monomers copolymerizable with the above-mentioned polymerizable (meth) acrylic monomers having a crosslinking functional group, polymerizable ultraviolet-stable monomers disclosed in Japanese Patent Laid-Open No. 1-261409 (reference 3) and Japanese Patent Laid-Open No. 3-006273 (reference 4) can be used.

Specific examples of the above-mentioned polymerizable ultraviolet-stable monomer include 4-(methyl)acryloyloxy-2, 2, 6, 6-tetramethylpiperidine, 4-(methyl)acryloylamino-2, 2, 6, 6-tetramethylpiperidine, 1-crotonyl-4-crotonyloxy-2, 2, 6, 6-tetramethylpiperidine, and 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone.

For example, by subjecting the above-mentioned monomer components to solution polymerization in the presence of a known free radical polymerization initiator such as a peroxide or azo compound, and diluting with an organic solvent as needed, an acrylic polymer can be obtained.

When obtaining an acrylic polymer with a water-based matrix, it can be produced by a method of converting an olefinic unsaturated compound into a water layer by solution polymerization or by a known method such as emulsion polymerization. In this case, the acidic part of the monomer containing carboxylic acid such as acrylic acid and methacrylic acid or the monomer containing sulfonic acid can be neutralized with amine or ammonia to give water solubility or water dispersibility.

[Ratio of content to hardener component]

In the adhesive resin composition of the present embodiment, the content of the polyisocyanate composition is preferably 0.01 to 20.00 parts by mass, more preferably 0.03 to 15.00 parts by mass, and further preferably 0.05 to 13.0 parts by mass, relative to 100 parts by mass of the polymer containing the crosslinking functional group.

<Other ingredients>

The adhesive resin composition of this embodiment may further include other additives.

As other additives, for example, hardeners other than polyisocyanate compositions that can react with polymers containing crosslinking functional groups, hardening catalysts, solvents, pigments (physical pigments, coloring pigments, metal pigments, etc.), adhesion-imparting resins, photopolymerization initiators, ultraviolet light absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents that inhibit coloring during the baking step, coating conditioners, flow conditioners, pigment dispersants, defoamers, thickeners, film-forming aids, etc. can be cited.

Examples of the above-mentioned hardener include melamine resins, urea resins, epoxy-containing compounds or resins, carboxyl-containing compounds or resins, acid anhydrides, alkoxysilane-containing compounds or resins, hydrazide compounds, etc.

The above-mentioned hardening catalyst may be an alkaline compound or a Lewis acid compound.

As the above-mentioned alkaline compound, for example, metal hydroxides, metal alkoxides, metal carboxylates, metal acetylacetonate, hydroxides of onium salts, onium carboxylates, halides of onium salts, metal salts of active methylene compounds, onium salts of active methylene compounds, aminosilanes, amines, phosphines, etc. As the above-mentioned onium salt, ammonium salts, phosphonium salts or cobalt salts are preferred.

Examples of the above-mentioned Lewis acidic compounds include organic tin compounds, organic zinc compounds, organic titanium compounds, organic zirconium compounds, etc.

Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene glycol dimethyl ether, methyl ethyl ketone, acetone, methyl Isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, isopropyl alcohol, 1-propanol, isobutyl alcohol, 1-butanol, tert-butyl alcohol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, isopentane, hexane, isohexane, cyclohexane, solvent naphtha, mineral spirits, etc. These solvents may be used alone or in combination of two or more.

In addition, as pigments (physical pigments, coloring pigments, metal pigments, etc.), ultraviolet absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents for inhibiting coloring during the baking step, coating conditioners, flow conditioners, pigment dispersants, defoamers, thickeners and film-forming aids, known ones can be appropriately selected for use.

<Method for producing adhesive resin composition>

The adhesive resin composition can be manufactured by a previously known method. For example, a melt kneading method using a Banbury mixer, a single-screw extruder, a twin-screw extruder, a bidirectional kneader, a multi-screw extruder, etc. can be used to dissolve or disperse the components and then apply them to the scratch film by a coating machine, etc., and then heat to remove the solvent.

In order to achieve the effects of lightening, softening, and improving adhesion, the adhesive resin composition of this embodiment can be foamed. As the foaming method, there are chemical methods, physical methods, and the use of thermal expansion microspheres. Bubbles can be distributed inside the material by adding chemical foaming agents such as inorganic foaming agents or organic foaming agents, physical foaming agents, etc., or adding thermal expansion microspheres.

In addition, by adding hollow fillers (expanded balls), it is possible to achieve weight reduction, flexibility, and improved adhesion.

In order to adjust the adhesive force, the adhesive resin composition of the present embodiment may be added with an adhesive-imparting resin. As the adhesive-imparting resin, for example, rosin-based adhesive-imparting resins, terpene-based adhesive-imparting resins, petroleum-based adhesive-imparting resins, styrene-based adhesive-imparting resins, etc. may be cited. Such adhesive-imparting resins may be used alone or in combination of two or more. In addition, the softening point of the adhesive-imparting resin is preferably above 90°C and below 160°C.

《Adhesive resin sheet》

The adhesive resin sheet of this embodiment is formed by hardening the above-mentioned adhesive resin composition by heat or light.

The adhesive resin sheet of this embodiment has excellent adhesion, bending resistance, holding power, curability, step tracking, impact resistance, durability, and transparency.

The thickness of the adhesive resin sheet (adhesive layer) of this embodiment can be appropriately determined according to the intended use, preferably 1 μm to 1000 μm, more preferably 2 μm to 900 μm, further preferably 3 μm to 800 μm, and particularly preferably 5 μm to 700 μm.

The adhesive resin sheet of the present embodiment can be manufactured, for example, by applying the adhesive resin composition to a substrate, drying it as needed, and then hardening it.

As a method of applying the adhesive resin composition to the substrate, for example, a coating method using an applicator, a roller coater, a doctor blade coater, a gravure coater, etc. can be cited. In the case of drying after the above coating, for example, a heat drying method of placing the obtained laminate in a dryer, for example, at a temperature of 50°C to 150°C for 1 minute to 30 minutes can be cited. Alternatively, as other drying methods, for example, natural drying, hot air drying, infrared drying, etc. can be cited.

The substrate is not particularly limited, and examples thereof include: high-grade paper, coated paper, glossy coated paper, thermal paper, inkjet paper, etc.; woven fabrics, non-woven fabrics, etc.; resin films such as polyvinyl chloride, synthetic paper, polyethylene terephthalate (PET), polypropylene, polyethylene, cellulose triacetate, cellulose diacetate, polystyrene, polycarbonate, nylon, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polyimide, etc.; porous resin films such as porous polypropylene films; evaporated films obtained by evaporating metals such as aluminum on PET, polyolefins, etc.; metal foils, etc. The substrate may be one that has been subjected to a peeling treatment on the surface.

The heating temperature during hardening can be set to be above 70℃ and below 160℃, above 75℃ and below 155℃, or above 80℃ and below 150℃.

Regarding the adhesive resin sheet of the present embodiment, the gel fraction is preferably 20.0 mass % to 99.9 mass %, more preferably 25.0 mass % to 99.9 mass %, further preferably 30.0 mass % to 99.9 mass %, particularly preferably 32.0 mass % to 99.9 mass %, and most preferably 35.0 mass % to 99.9 mass %. The gel fraction is obtained by peeling off the above-exfoliated polymer from a laminate of an adhesive resin sheet having a thickness of 50 μm. The above-mentioned adhesive resin sheet obtained from the polyethylene terephthalate film was stored in an environment of 23°C and 50% RH for 7 days, then wrapped with a mesh sheet, immersed in ethyl acetate at 23°C for 1 week, taken out, and dried at 120°C for 2 hours. The 50μm thick adhesive resin sheet was obtained by applying the above-mentioned adhesive resin composition on a 38μm thick polyethylene terephthalate film that had been peeled, drying it at 135°C for 3 minutes to harden it, and then storing it at 23°C and 50% RH for 7 days. By making the gel fraction above the above lower limit, the adhesion, retention, durability, bending resistance, and hardening properties are more excellent.

Furthermore, the gel fraction mentioned here is the percentage of the mass of the above-mentioned adhesive resin sheet after being immersed in ethyl acetate and then dried relative to the mass of the above-mentioned adhesive resin sheet before being immersed in ethyl acetate.

Regarding the adhesive resin sheet of the present embodiment, the 180-degree peeling adhesion is preferably 0.05N/20mm to 65.00N/20mm, more preferably 0.05N/20mm to 64.50N/20mm, further preferably 0.05N/20mm to 64.00N/20mm, particularly preferably 0.05N/20mm to 63.50N/20mm, and most preferably 0.05N/20mm to 63.00N/20mm. The 180-degree peeling adhesion is for a sheet having a thickness of 50μm and a width of The laminate of the adhesive resin sheet with a thickness of 20 mm and a length of 100 mm was attached to the SUS304BA plate as the adherend, and a 2kg roller was used for one reciprocating press bonding. After curing at 23°C for 30 minutes, the adhesive resin sheet with a thickness of 50 μm, a width of 20 mm and a length of 100 mm was measured at a speed of 300 mm/min at 23°C. The adhesive resin composition was applied to a polyethylene terephthalate film with a thickness of 25 μm, dried at 135°C for 3 minutes to harden, and then stored at 23°C and 50% RH for 7 days. By making the 180-degree peeling adhesion above the above lower limit, the adhesion is more excellent.

Regarding the adhesive resin sheet of the present embodiment, the adhesive resin sheet having a thickness of 50 μm is attached to a glass having a haze value of 0.1% and the haze value measured by a haze meter is preferably 2.0% or less, more preferably 1.8% or less, further preferably 1.6% or less, particularly preferably 1.3% or less, and most preferably 1.0% or less. The adhesive resin sheet having a thickness of 50 μm is obtained by applying the above-mentioned adhesive resin composition on a polyethylene terephthalate film having a thickness of 38 μm and subjected to a peeling treatment, drying at 135°C for 3 minutes to harden it, and then storing it at 23°C and 50% RH for 7 days, and peeling it from the above-mentioned polyethylene terephthalate film having been subjected to a peeling treatment. By making the haze value below the above upper limit, the transparency is better. On the other hand, the lower limit of the haze value of the above adhesive resin sheet is not particularly limited, and the closer to 0.0%, the better. For example, it can be set to 0.0% or 0.05%.

《Accumulative membrane》

The laminated film of this embodiment is formed by laminating a film substrate on at least one surface of the above-mentioned adhesive resin sheet.

The laminated film of this embodiment is suitable for use in optical components, and is particularly suitable for use in optical applications where it is attached to a metal film or metal electrode. As the metal film, there are examples of films containing metals, metal oxides, or mixtures thereof, without particular limitation, such as ITO (indium tin oxide), ZnO, SnO, and CTO (cadmium tin oxide) films. The thickness of the metal film is not particularly limited, and is about 10 to 200 nm. Usually, metal films such as ITO are disposed on transparent plastic film substrates such as polyethylene terephthalate films (PET films) and used as transparent conductive films. When attaching the laminated film of this embodiment to the metal film, it is preferred to attach the surface of the adhesive resin sheet side to the metal film.

Furthermore, the metal electrode mentioned above may be an electrode containing a metal, a metal oxide or a mixture thereof, and is not particularly limited. Examples thereof include electrodes of ITO, silver, copper, and CNT (carbon nanotube).

As an example of a specific use of the multilayer film of this embodiment, a touch panel can be cited. The adhesive sheet for touch panels is used, for example, in the manufacture of electrostatic capacitive touch panels to bond a transparent conductive film provided with a metal film such as ITO to a polymethyl methacrylate resin (PMMA) plate, a hard coating film, a glass lens, etc. The above-mentioned touch panel is not particularly limited, and can be used, for example, in mobile phones, tablet computers, portable information terminals, etc.

Furthermore, an optical component can be used as a film substrate of the laminated film of this embodiment. In this case, the above-mentioned adhesive resin composition can be directly applied to the optical component and dried to remove the polymerization solvent, etc., to obtain an adhesive optical component in which the adhesive resin sheet is formed on the optical component. Alternatively, the adhesive resin sheet formed on the spacer after the peeling treatment can be appropriately transferred to the optical component to obtain an adhesive optical component.

Furthermore, the peeled sheet used in the production of the above-mentioned adhesive optical component can be directly used as a spacer for the adhesive optical component, which can simplify the steps.

Furthermore, in the above-mentioned adhesive optical component, when forming the adhesive layer, a fixed layer can be formed on the surface of the optical component, or the adhesive layer can be formed after various easy-to-bond treatments such as corona treatment and plasma treatment. Furthermore, the surface of the adhesive layer can be subjected to easy-to-bond treatment.

The above-mentioned adhesive optical component can be used as a transparent conductive film with an adhesive layer by using a transparent conductive film as an optical component. The transparent conductive film has a metal film such as the above-mentioned ITO as a transparent conductive film on one side of a transparent plastic film substrate. On the other side of the transparent plastic film substrate, there is a laminated film of this embodiment. On the transparent plastic film substrate, a transparent conductive film can be provided via a primer layer. Furthermore, the primer layer can be provided in multiple layers. An oligomer migration prevention layer can be provided between the transparent plastic film substrate and the adhesive resin sheet.

As the transparent plastic film substrate, there is no particular limitation, and various plastic films with transparency can be used. The plastic film can be formed by a single layer of film. For example, as its material, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, triacetyl cellulose resins, etc. can be cited. Among them, polyester resins, polyimide resins and polyether sulfone resins are particularly preferred. The thickness of the above-mentioned film substrate is preferably 15~200μm.

The surface of the above-mentioned film substrate may be subjected to etching treatment or primer treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical treatment, oxidation, etc. in advance to improve the adhesion between the transparent conductive film or primer layer disposed thereon and the above-mentioned film substrate. In addition, before the transparent conductive film or primer layer is disposed, dust removal and cleaning may be performed by solvent cleaning or ultrasonic cleaning as needed.

The constituent material and thickness of the transparent conductive film are not particularly limited, as exemplified in the metal film. The base coating layer may be formed of an inorganic substance, an organic substance, or a mixture of an inorganic substance and an organic substance. For example, as inorganic substances, there may be cited NaF (1.3), Na ₃ AlF ₆ (1.35), LiF (1.36), MgF ₂ (1.38), CaF ₂ (1.4), BaF ₂ (1.3), SiO ₂ (1.46), LaF ₃ (1.55), CeF ₃ (1.63), Al ₂ O ₃ (1.63), etc. [The values in parentheses of the above materials are the refractive index of light]. Among them, SiO ₂ , MgF ₂ , Al ₂ O ₃ , etc. are preferred, and SiO ₂ is particularly preferred. In addition to the above, a composite oxide containing about 10 to 40 parts by weight of calcium oxide and about 0 to 20 parts by weight of tin oxide relative to indium oxide can be used.

In addition, as organic materials, acrylic resins, polyurethane resins, melamine resins, alkyd resins, silicone polymers, organic silane condensates, etc. can be cited. At least one of these organic materials is used. As the organic material, it is particularly desirable to use a thermosetting resin that is a mixture of melamine resins, alkyd resins, and organic silane condensates.

There is no particular restriction on the thickness of the base coating layer. Based on the optical design and the effect of preventing oligomers from being generated from the above-mentioned film substrate, it is usually around 1~300nm, preferably 5~300nm.

The transparent conductive film with adhesive layer can be used in the formation of various devices such as touch panels, liquid crystal displays, organic EL (electroluminescence) displays, etc. It is particularly suitable for use as an electrode plate for touch panels. The touch panel is suitable for various detection methods (such as resistance film method, electrostatic capacitance method, etc.).

Regarding the electrostatic capacitive touch panel, a transparent conductive film having a prescribed pattern shape is usually formed on the entire surface of the display portion of the display. The transparent conductive film with the adhesive layer is appropriately laminated in a manner that the adhesive layer and the patterned transparent conductive film face to face.

Furthermore, the above-mentioned adhesive optical component can be used as an optical film with an adhesive layer by using an optical film for an image display device as an optical component.

As an optical film, it can be used in the formation of image display devices such as liquid crystal display devices and organic EL display devices, and its type is not particularly limited. For example, as an optical film, a polarizing plate can be cited. Polarizing plates are generally used in polarizing elements with a transparent protective film on one or both sides.

[Implementation example]

The present embodiment is described in more detail below based on embodiments and comparative examples, but the present embodiment is not limited to the following embodiments.

<Test items>

For the polyisocyanate compositions produced in the examples and comparative examples, various physical properties were measured and evaluated according to the methods shown below.

[Physical properties 1]

(Isocyanate group content)

First, accurately weigh a test sample (W g) of more than 2 g but less than 3 g and place it in a flask. Next, add 20 mL of toluene to dissolve the test sample. Next, add 20 mL of a 2-N concentration di-n-butylamine toluene solution, mix, and place at room temperature for 15 minutes. Next, add 70 mL of isopropanol and mix. Next, titrate the solution with a 1-N concentration hydrochloric acid solution (factor F) into the indicator. Set the obtained titration value as V2 mL. Next, in the absence of a polyisocyanate sample, set the obtained titration value as V1 ml. Next, calculate the isocyanate group content (NCO%) (mass %) of the polyisocyanate composition by the following formula. In addition, NCO% is the value calculated without the solvent.

Isocyanate group content (mass %) = (V1-V2) × F × 42/(W × 1000) × 100

[Physical properties 2]

(Number average molecular weight and weight average molecular weight)

The number average molecular weight and weight average molecular weight are based on polystyrene and are measured by gel permeation chromatography (GPC) using the following apparatus.

(Measurement conditions)

Device: Tosoh Co., Ltd., HLC-802A

Column: Made by Tosoh Co., Ltd., G1000HXL × 1 piece, G2000HXL × 1 piece, G3000HXL × 1 piece

Carrier: Tetrahydrofuran

Testing method: differential refractometer

[Physical properties 3]

(Average number of isocyanate functional groups)

The average isocyanate functional group number (average NCO number) of the polyisocyanate composition is calculated by the following formula. In the formula, "Mn" means the number average molecular weight, and the value measured in the above "Physical Property 2" is used. "NCO%" uses the value calculated in the above "Physical Property 1".

Average number of isocyanate functional groups = (Mn×NCO%×0.01)/42

[Physical properties 4]

(Glass transition temperature Tg)

The glass transition temperature of the polyol and the polymer containing cross-linking functional groups used in the preparation of the resin composition is the following value, which is obtained by dispersing the organic solvent and water in the acrylic polyol solution or the polymer solution containing cross-linking functional groups under reduced pressure and then vacuum drying, and measuring it using a differential scanning calorimeter (DSC) measuring device at a heating rate of 5°C/min.

[Preparation of a hardened film 1 composed solely of a polyisocyanate composition]

Each polyisocyanate composition was applied to the release film using an applicator and stored at 23°C and 65% humidity for 168 hours to obtain a cured film with a thickness of 40μm.

[Evaluation 1]

(Softness of hardened film)

For the hardened film, the Koenig hardness (times) in a 23°C environment is measured using a Koenig hardness tester (BYK Gardner's Pendulum hardness tester). Those with a Koenig hardness of 60 times or less are evaluated as having low hardness and good softness.

[Production of hardened film 2]

The polyisocyanate compositions and the resin composition-preparing polyols were mixed in such a manner that the molar ratio of the isocyanate group of the polyisocyanate composition to the hydroxyl group of the resin composition-preparing polyol (NCO/OH) was 1, thereby obtaining resin compositions. The obtained resin compositions were applied to a polypropylene (PP) plate by an applicator, cured at 90°C for 30 minutes, and stored at 23°C and 65% humidity for 168 hours to obtain a cured film 2 with a film thickness of 40μm.

[Evaluation 2]

(Stress, elongation, and tensile fracture stress at 140% elongation)

For the obtained cured film 2, a test piece with a width of 10 mm and a length of 100 mm was placed in a tensile testing machine with a clamp distance of 20 mm, and a tensile test was performed at a speed of 20 mm/min to measure the stress, elongation, and tensile fracture stress at an elongation of 140%. The stress at an elongation of 140% was 25.0 MPa or less, the elongation was 140% or more, and the tensile fracture stress was 1.2 times or more of the stress at an elongation of 140%, and the ratio of the stress at an elongation of 140%, the elongation, and the tensile fracture stress to the stress at an elongation of 140% was evaluated as good. In addition, the ones with larger elongation, lower stress at 140% elongation and tensile fracture stress of 1.2 times or more of the stress at 140% elongation are evaluated as having better bending resistance.

[Preparation of adhesive resin composition X]

Relative to 100 parts by weight of the solid content of the polymer (acrylic polymer) OH1 containing a crosslinking functional group, 1.0 parts by weight (solid content) of each polyisocyanate composition and ethyl acetate were added to prepare an adhesive resin composition X with a solid content of 25% by weight.

[Preparation of adhesive resin composition Y]

Relative to 100 parts by weight of the solid content of the polymer (acrylic polymer) OH2 containing a crosslinking functional group, 2.0 parts by weight (solid content) of each polyisocyanate composition and ethyl acetate were added to prepare an adhesive resin composition Y with a solid content of 25% by weight.

[Production of adhesive resin sheet 1]

(Preparation of adhesive resin sheet for 180 degree peeling adhesion measurement)

Adhesive resin composition X or adhesive resin composition Y was applied to a 25 μm thick polyethylene terephthalate (PET) film by an applicator in such a way that the thickness after drying was 50 μm, and dried at 135°C for 3 minutes. Thereafter, the film was stored at 23°C and 50% RH for 7 days to obtain an adhesive resin sheet for 180-degree peel adhesion measurement.

[Rating 3]

(Adhesion)

The laminated body of the adhesive resin sheet with a thickness of 50μm, a width of 20mm and a length of 100mm obtained in the above "Preparation of Adhesive Resin Sheet 1" was attached to the SUS304BA plate as the adherend, and a 2kg roller was used to perform a reciprocating press bonding once. After curing at 23℃ for 30 minutes, the 180-degree peeling adhesion was measured at a speed of 300mm/minute at 23℃ using a tensile tester. The 180-degree peeling adhesion of 0.05N/20mm or more was evaluated as good adhesion.

[Production of adhesive resin sheet 2]

(Preparation of adhesive resin sheets for gel fraction measurement)

Adhesive resin composition X or adhesive resin composition Y was applied to a 38 μm thick PET film that had been peeled by an applicator in such a way that the thickness after drying was 50 μm, and dried at 135°C for 3 minutes. Thereafter, it was stored at 23°C and 50% RH for 7 days to obtain an adhesive resin sheet for gel fraction measurement.

[Rating 4]

(hardening)

Use about 0.1g to 0.2g of the adhesive resin sheet obtained in the above "Adhesive resin sheet preparation 2", wrap it with a mesh sheet, immerse it in ethyl acetate for 1 week, and dry it at 120℃ for 2 hours. Then, calculate the gel fraction (mass %) using the following formula. Those with a gel fraction of 20.0 mass % or more are evaluated as having good curability.

(Gel fraction) = (sample mass after drying) / (sample mass before ethyl acetate addition) × 100

[Production of adhesive resin sheet 3]

(Preparation of a laminate with adhesive resin sheets for haze value measurement)

Adhesive resin composition X or adhesive resin composition Y was applied to a 38 μm thick polyethylene terephthalate film that had been subjected to peeling treatment, dried at 135°C for 3 minutes to harden, and then stored at 23°C and 50% RH for 7 days. The adhesive resin sheet with a thickness of 50 μm was obtained by peeling off the above-mentioned polyethylene terephthalate film that had been subjected to peeling treatment. The adhesive resin sheet was bonded to a glass with a haze value of 0.1% to obtain a laminate having an adhesive resin sheet for measuring haze value.

[Rating 5]

(Transparency)

For the laminate obtained by laminating the cured film obtained in the above "Preparation of the Cured Film of the Polyisocyanate Composition" on a glass with a haze value of 0.1% and the laminate obtained in the above "Preparation of the Adhesive Resin Sheet 3", the surface on the opposite side of the glass (i.e. the surface coated with the polyisocyanate composition or the adhesive resin composition) of the two surfaces of each laminate was placed on the light source side, and the haze was measured using a haze meter (HMG-2DP) manufactured by Suga Test Instruments. The haze value of 3.0% or less was evaluated as having good transparency.

<Manufacturing of polyols using resin compositions>

[Synthesis Example 1-1]

(Manufacturing of polyols using resin compositions)

In a four-necked flask equipped with a stirring device, a thermometer, a cooling tube, and a nitrogen inlet, 29 parts by mass of butyl acetate was added, and the temperature was raised to 112°C while nitrogen was introduced. After reaching 112°C, the introduction of nitrogen was stopped, and a mixture containing 22.3 parts by mass of 2-hydroxyethyl methacrylate, 8.0 parts by mass of methyl methacrylate, 26.1 parts by mass of butyl acrylate, 42.3 parts by mass of styrene, 1.3 parts by mass of acrylic acid, and 2 parts by mass of 2,2'-azobis(isobutyronitrile) was added dropwise over 5 hours. Next, the mixture was stirred at 115°C while nitrogen was introduced for 3 hours, and then cooled to 60°C, and the butyl acetate solution was added to obtain a resin composition having a solid content of 60% by mass to prepare a polyol solution. The glass transition temperature Tg of the polyol prepared from the resin composition is 29.5°C, the hydroxyl value relative to the resin solid content is 139 mgKOH/g, and the weight average molecular weight Mw is 2.75×10 ⁴ .

<Synthesis of polymers containing cross-linking functional groups>

[Synthesis Example 2-1]

(Synthesis of polymer OH1 containing cross-linking functional groups (acrylic polymer))

In a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a cooling tube, 97 parts by mass of n-butyl acrylate (BA) and 3 parts by mass of 4-hydroxybutyl acrylate (4-HBA) were added, and 145 parts by mass of ethyl acetate as a solvent was added. Next, while stirring under a nitrogen atmosphere, 0.14 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) was added as a polymerization initiator, and the reaction was carried out at 63°C for 9 hours. After the reaction, the reaction was cooled to obtain an acrylic polymer OH1 with a solid content concentration of 42.1% by mass. The glass transition temperature of the acrylic polymer OH1 measured by removing the solvent was -54.0°C, and the weight average molecular weight was 8.2×10 ⁵ .

[Synthesis Example 2-2]

(Synthesis of polymers containing cross-linking functional groups (acrylic polymers) OH2)

In a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a cooling tube, 97 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3 parts by mass of 4-hydroxybutyl acrylate (4-HBA) were added, and 145 parts by mass of ethyl acetate as a solvent was added. Next, while stirring under a nitrogen atmosphere, 0.14 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added, and the reaction was carried out at 63°C for 9 hours. After the reaction, the reaction was cooled to obtain an acrylic polymer OH2 with a solid content concentration of 42.2% by mass. The glass transition temperature of the acrylic polymer OH2 measured by removing the solvent was -69.0°C, and the weight average molecular weight was 8.7×10 ⁵ .

<Manufacturing of polyisocyanate compositions>

[Implementation Example 1]

(Manufacturing of polyisocyanate composition PA-a1)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 120 parts by mass of a difunctional polycaprolactone diol (hereinafter sometimes referred to as "polyester polyol A1") (manufactured by Daicel, trade name "PLACCEL 220CPT", number average molecular weight 2000, hydroxyl value 56.6 mgKOH/g, acid value 0.02 mgKOH/g) (the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyester polyol A1 is 9.8) were added under a nitrogen flow, and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 55.0% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain polyisocyanate composition PA-a1. The obtained polyisocyanate composition PA-a1 was analyzed by H-NMR (Hydrogen-Nuclear Magnetic Resonance) and C-NMR (Carbon-Nuclear Magnetic Resonance) to confirm the presence of urethane bonds and allophanate bonds. Among these bonds, the molar ratio of urethane bonds was the highest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

二

二酮基、異氰尿酸基、脲基、胺基甲酸酯基、及縮二脲基檢測到之合計莫耳量為1%以上者，計為該鍵存在。又，於以下實施例中亦採用相同方法，對鍵進行計數。 Furthermore, the structure was determined by NMR (nuclear magnetic resonance) analysis by measuring the ratio (molar %) of each bond relative to the allophanate group, uretdione group, imine group,

two

The total molar amount of diketone group, isocyanurate group, urea group, carbamate group, and biuret group detected is 1% or more, and the bond is counted. In addition, the same method is also used in the following examples to count the bonds.

[Example 2]

(Manufacturing of polyisocyanate composition PA-a2)

In a four-necked flask equipped with a thermometer, a stirring wing, and a reflux cooling tube, 100 parts by mass of HDI and 135 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 8.7) are added under a nitrogen flow and stirred, and the temperature in the reactor is maintained at 100°C. The reaction is stopped at the time point when the yield is 58.0% by mass. After filtering the reaction solution, unreacted HDI is removed by a thin film distillation device to obtain a polyisocyanate composition PA-a2. The obtained polyisocyanate composition PA-a2 is analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups is the largest. Then, butyl acetate was added to the obtained polyisocyanate composition to dilute it to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 3]

(Manufacturing of polyisocyanate composition PA-a3)

In a four-necked flask equipped with a thermometer, a stirring wing, and a reflux cooling tube, 100 parts by mass of HDI, 0.5 parts by mass of 1,3-butanediol, and 125 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 9.4) were added under a nitrogen flow and stirred. The temperature in the reactor was maintained at 160°C for 20 minutes, then reduced to 100°C and maintained. The reaction was stopped at a yield of 56.0% by mass. After filtering the reaction solution, unreacted HDI was removed by a thin film distillation device to obtain a polyisocyanate composition PA-a3. The obtained polyisocyanate composition PA-a3 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate group, allophanate group, uretdione group, and urea group. Among these groups, the molar ratio of carbamate group was the largest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 4]

(Manufacturing of polyisocyanate composition PA-a4)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 150 parts by mass of a difunctional polycaprolactone diol (hereinafter sometimes referred to as "polyester polyol A2") (manufactured by Daicel, trade name "PLACCEL 230", number average molecular weight 3000, hydroxyl value 37.6 mgKOH/g, acid value 0.07 mgKOH/g) (the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyester polyol A2 is 11.8) were added under a nitrogen flow, and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 60.5% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain polyisocyanate composition PA-a4. The obtained polyisocyanate composition PA-a4 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the highest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was solid at 23°C.

[Implementation Example 5]

(Manufacturing of polyisocyanate composition PA-a5)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 200 parts by mass of difunctional polycaprolactone diol (hereinafter sometimes referred to as "polyester polyol A3") (manufactured by Daicel, trade name "PLACCEL 240", number average molecular weight 4000, hydroxyl value 28.5 mgKOH/g, acid value 0.07 mgKOH/g) (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A3 is 11.7) were added under nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 67.0% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain polyisocyanate composition PA-a5. The obtained polyisocyanate composition PA-a5 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the highest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was solid at 23°C.

[Implementation Example 6]

(Manufacturing of polyisocyanate composition PA-a6)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI, 0.8 parts by mass of 2-ethylhexanol, and 125 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 9.4) were added under a nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at a time point when the yield was 56.0% by mass. After filtering the reaction solution, unreacted HDI was removed by a thin film distillation device to obtain a polyisocyanate composition PA-a6. The obtained polyisocyanate composition PA-a6 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the largest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 7]

(Manufacturing of polyisocyanate composition PA-a7)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI, 0.5 parts by mass of 1,3-butanediol, and 118 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 10.0) were added under a nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at a time point when the yield was 54.7% by mass. After filtering the reaction solution, the unreacted HDI was removed by a thin film distillation device to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 1:3 parts by mass of polyester polyol A was added to 100 parts by mass of the intermediate of the obtained polyisocyanate composition under a nitrogen flow, and the mixture was kept at 100°C for 2 hours to obtain a polyisocyanate composition PA-a7. The obtained polyisocyanate composition PA-a7 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the largest. Subsequently, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 8]

(Manufacturing of polyisocyanate composition PA-a8)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 37.5 parts by mass of trifunctional polycaprolactone polyol (hereinafter sometimes referred to as "polyester polyol B1") (manufactured by Daicel, trade name "PLACCEL 308", number average molecular weight 850, hydroxyl value 195.3 mgKOH/g, acid value 0.38 mgKOH/g) (the molar ratio of isocyanate group of HDI to hydroxyl group of polyester polyol B1 is 9.1) were added under nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 40.5% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain polyisocyanate composition PA-a8. The obtained polyisocyanate composition PA-a8 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the highest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Examples 9 to 12]

(Manufacturing of polyisocyanate compositions PA-a9~PA-a12)

In addition to the formula shown in Table 2, each polyisocyanate composition was prepared using the same method as Example 8. The obtained polyisocyanate composition was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the largest. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 13]

(Manufacturing of polyisocyanate composition PA-a13)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI, 1.0 parts by mass of 1,3-butanediol, and 115 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 10.2) were added under a nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at a yield of 53.0% by mass. After filtering the reaction solution, unreacted HDI was removed by a thin film distillation device to obtain a polyisocyanate composition PA-a13. The obtained polyisocyanate composition PA-a13 was analyzed by H-NMR and C-NMR to confirm the presence of urethane bonds and allophanate bonds. Among these bonds, the molar ratio of urethane bonds was the largest. Then, ethyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Example 14]

(Manufacturing of polyisocyanate composition PA-a14)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI, 1.5 parts by mass of 1,3-butanediol, and 112 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 10.5) are added under a nitrogen flow and stirred, and the temperature in the reactor is maintained at 100°C. The reaction is stopped at a time point when the yield is 51.5% by mass. After filtering the reaction solution, unreacted HDI is removed by a thin film distillation device to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 1:3 parts by mass of polyester polyol A was added to 100 parts by mass of the intermediate of the obtained polyisocyanate composition under a nitrogen flow, and 2-ethylhexyl acid phosphate (manufactured by Chengbei Chemical Industry Co., Ltd., trade name "JP508T") was added at 90 ppm by mass relative to the resin. The temperature in the reactor was maintained at 95°C for 120 minutes to obtain the polyisocyanate component PA-a14. The obtained polyisocyanate composition PA-a14 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the largest. Thereafter, ethyl acetate was added to the obtained polyisocyanate composition to dilute it to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 15]

(Manufacturing of polyisocyanate composition PA-a15)

In a four-necked flask equipped with a thermometer, a stirring wing, and a reflux cooling tube, 100 parts by mass of HDI, 2.0 parts by mass of 1,3-butanediol, and 130 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 9.1) are added under a nitrogen flow and stirred. The temperature in the reactor is maintained at 160°C for 20 minutes, then reduced to 100°C and maintained. The reaction is stopped at a yield of 56.3% by mass. After filtering the reaction solution, unreacted HDI is removed by a thin film distillation device to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 2 parts by mass of polyester polyol A1 and 0.2 parts by mass of methyl polyalkylene glycol (repeating unit n=15) were added to 100 parts by mass of the intermediate of the obtained polyisocyanate composition under a nitrogen flow and stirred. 2-ethylhexyl acid phosphate (manufactured by Chengbei Chemical Industry Co., Ltd., trade name "JP508T") was added at 90 ppm by mass relative to the resin. The temperature in the reactor was maintained at 95°C for 120 minutes to obtain polyisocyanate component PA-a15. The obtained polyisocyanate composition PA-a15 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate group, allophanate group, uretdione group, and urea group. Among these groups, the molar ratio of carbamate group was the highest. Then, ethyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 16]

(Manufacturing of polyisocyanate composition PA-a16)

In a four-necked flask equipped with a thermometer, a stirring wing, and a reflux cooling tube, 100 parts by mass of HDI, 2.5 parts by mass of 1,3-butanediol, and 135 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 8.7) are added under a nitrogen flow and stirred. The temperature in the reactor is maintained at 160°C for 20 minutes, then reduced to 100°C and maintained. The reaction is stopped at a yield of 58.7% by mass. After filtering the reaction solution, unreacted HDI is removed by a thin film distillation device to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 1:3 parts by mass of polyester polyol A was added to 100 parts by mass of the intermediate of the obtained polyisocyanate composition under a nitrogen flow, and 2-ethylhexyl acid phosphate (manufactured by Chengbei Chemical Industry Co., Ltd., trade name "JP508T") was added at 90 ppm by mass relative to the resin, and the temperature in the reactor was maintained at 95°C for 120 minutes to obtain polyisocyanate component PA-a16. The obtained polyisocyanate composition PA-a16 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate group, allophanate group, uretdione group, and urea group. Among these groups, the molar ratio of carbamate group was the largest. Thereafter, ethyl acetate was added to the obtained polyisocyanate composition to dilute it to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Example 17]

(Manufacturing of polyisocyanate composition PA-a17)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 215 parts by mass of difunctional polycaprolactone diol (hereinafter sometimes referred to as "polyester polyol A3") (manufactured by Daicel, trade name "PLACCEL 240", number average molecular weight 4000, hydroxyl value 28.5 mgKOH/g, acid value 0.07 mgKOH/g) (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A3 is 10.9) were added under a nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 69.0% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain polyisocyanate composition PA-a17. The obtained polyisocyanate composition PA-a17 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the highest. Thereafter, ethyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was solid at 23°C.

[Implementation Example 18]

(Manufacturing of polyisocyanate composition PA-a18)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 115 parts by mass of polyester polyol A1 (the molar ratio of the isocyanate group of HDI to the hydroxyl group of polyester polyol A1 is 10.2) were added under a nitrogen flow and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield was 52.2% by mass. After filtering the reaction solution, the unreacted HDI was removed by a thin film distillation device to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 1.0 mass part of 1,3-butanediol was added to 100 mass parts of the intermediate of the obtained polyisocyanate composition under a nitrogen flow, and the temperature in the reactor was maintained at 160°C for 1 hour to obtain the polyisocyanate component PA-a18. The obtained polyisocyanate composition PA-a18 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate group, allophanate group, uretdione group, and urea group. Among these groups, the molar ratio of carbamate group was the largest. Thereafter, ethyl acetate was added to the obtained polyisocyanate composition to dilute it to a solid content of 70 mass%. The polyisocyanate composition in this state was liquid at 23°C.

[Implementation Example 19]

(Manufacturing of polyisocyanate composition PA-a19)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI and 35.0 parts by mass of trifunctional polycaprolactone polyol (hereinafter sometimes referred to as "polyester polyol B1") (manufactured by Daicel, trade name "PLACCEL 308", number average molecular weight 850, hydroxyl value 195.3 mgKOH/g, acid value 0.38 mgKOH/g) (the molar ratio of isocyanate group of HDI to hydroxyl group of polyester polyol B1 is 9.8) were added under nitrogen flow, and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield reached 40.7% by mass. After filtering the reaction solution, unreacted HDI was removed by thin film distillation to obtain an intermediate of a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 4.0 parts by mass of polyester polyol B1 was added to 100 parts by mass of the intermediate of the obtained polyisocyanate composition under a nitrogen flow, and 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., trade name "JP508T") was added at 90 ppm by mass relative to the resin, and the temperature in the reactor was maintained at 95°C for 120 minutes to obtain a polyisocyanate component PA-a19. The obtained polyisocyanate composition PA-a19 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the highest. Subsequently, ethyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Example 20]

(Manufacturing of polyisocyanate composition PA-a20)

In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux cooling tube, 100 parts by mass of HDI, 36.0 parts by mass of trifunctional polycaprolactone polyol (hereinafter sometimes referred to as "polyester polyol B1") (manufactured by Daicel, trade name "PLACCEL 308", number average molecular weight 850, hydroxyl value 195.3 mgKOH/g, acid value 0.38 mgKOH/g), and 100 parts by mass of trifunctional polycaprolactone polyol (hereinafter sometimes referred to as "polyester polyol B2") (manufactured by Daicel, trade name "PLACCEL 312", number average molecular weight 1250, hydroxyl value 136.1 mgKOH/g): 4.0 parts by mass (the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyester polyols B1 and B2 is 8.8) and stirred, and the temperature in the reactor was maintained at 100°C. The reaction was stopped at the time point when the yield was 41.7% by mass. After filtering the reaction solution, the unreacted HDI was removed by a thin film distillation device to obtain a polyisocyanate composition PA-a20. The obtained polyisocyanate composition PA-a20 was analyzed by H-NMR and C-NMR to confirm the presence of carbamate groups and allophanate groups. Among these groups, the molar ratio of carbamate groups was the largest. Thereafter, ethyl acetate was added to the obtained polyisocyanate composition to dilute it to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Comparison Example 1]

(Manufacturing of polyisocyanate composition PA-b1)

In a four-necked flask equipped with a thermometer, a stirring blade and a reflux cooling tube, 100 parts by mass of HDI and 8.9 parts by mass of trihydroxymethylpropane were added under a nitrogen flow, and the temperature in the reactor was kept at 75°C for 5 hours while stirring to carry out the urethanization reaction. After filtering the reaction solution, the unreacted HDI was removed using a thin film evaporator to obtain a polyisocyanate composition PA-b1 containing an isocyanurate-type polyisocyanate. Subsequently, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Comparison Example 2~3]

(Manufacturing of polyisocyanate compositions PA-b2~PA-b3)

In addition to the formula shown in Table 3, the same method as Example 1 was used to obtain each polyisocyanate composition. Then, butyl acetate was added to the obtained polyisocyanate composition and diluted to a solid content of 70% by mass. The polyisocyanate composition in this state was liquid at 23°C.

[Comparison Example 4]

(Manufacturing of polyisocyanate composition PA-b4)

The interior of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was replaced with nitrogen, and 1000 g of HDI was added. While stirring at 60°C, 0.09 g of tetramethylammonium octanoate and 1.3 g of isobutyl alcohol were added as catalysts. After 4.5 hours, the reaction endpoint was confirmed by measuring the refractive index of the reaction solution, and 0.2 g of phosphoric acid was added to stop the reaction. Afterwards, the reaction solution was filtered, and the unreacted HDI monomer was removed by a thin film distillation device to obtain polyisocyanate. The isocyanate content of the obtained polyisocyanate was 23.1% by mass, and the average functional group number of the isocyanate group was 3.4. The obtained polyisocyanate composition PA-b4 was analyzed by H-NMR and C-NMR to confirm the presence of isocyanuric acid groups. Among these groups, the molar ratio of isocyanuric acid groups is the highest.

[Comparison Example 5]

(Manufacturing of polyisocyanate composition PA-b5)

The interior of a four-necked flask equipped with a stirrer, a thermometer, and a cooling tube was replaced with nitrogen, and 1000 g of HDI, 7.2 g of water, and 600 g of ethylene glycol monomethyl ether acetate were mixed at room temperature and reacted at 140°C under normal pressure for 120 minutes. Then, the reaction was carried out at 160°C for 1 hour. No precipitate or turbidity was observed. After that, the reaction solution was filtered, and the unreacted HDI monomer and solvent were removed by a thin film distillation device to obtain polyisocyanate. The isocyanate content of the obtained polyisocyanate was 23.4% by mass, and the average functional group number of the isocyanate group was 3.4. The obtained polyisocyanate composition PA-b5 was analyzed by H-NMR and C-NMR to confirm the presence of biuret.

The physical properties of the polyisocyanate compositions obtained in the examples and comparative examples, and the results of the evaluations performed using the above-described methods are shown in the following Tables 1 to 3. Furthermore, in Comparative Example 1, when the stress at an elongation of 140% was measured, the elongation was not elongated to 140%, and the stress at the fracture point was 73 MPa, which could not be measured, so it was marked as "-" in the table. The same is true for Comparative Examples 4 and 5.

In addition, in Tables 1 to 3, each abbreviation means the following compound.

(Polyester polyol (A))

A1: Difunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 220CPT", number average molecular weight 2000, hydroxyl value 56.6 mgKOH/g, acid value 0.02 mgKOH/g

A2: Difunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 230", number average molecular weight 3000, hydroxyl value 37.6 mgKOH/g, acid value 0.07 mgKOH/g

A3: Difunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 240", number average molecular weight 4000, hydroxyl value 28.5mgKOH/g, acid value 0.07mgKOH/g

(Other diols (A'))

A'1: Polytetramethylene ether glycol, manufactured by Mitsubishi Chemical Co., Ltd., trade name "PTMG1000", number average molecular weight 1000

A'2: Polyether polyol, manufactured by Asahi Glass Co., Ltd., trade name "Excenol 2020", number average molecular weight 2000

(Polyester polyol (B))

B1: trifunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 308", number average molecular weight 850, hydroxyl value 195.3 mgKOH/g, acid value 0.38 mgKOH/g

B2: trifunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 312", number average molecular weight 1250, hydroxyl value 136.1 mgKOH/g, acid value 0.38 mgKOH/g

B3: trifunctional polycaprolactone polyol, manufactured by Daicel, trade name "PLACCEL 305", number average molecular weight 550

(Other trihydric polyols (B'))

B'1: Trihydroxymethylpropane (TMP)

As shown in Tables 1 to 3, in the polyisocyanate compositions PA-a1 to PA-a20 (Examples 1 to 20) derived from aliphatic or alicyclic diisocyanates and polyester polyols (A) or polyester polyols (B) having specific physical properties, in which the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol is within a specific numerical range and the weight average molecular weight is within a specific numerical range, a cured film obtained by curing the polyisocyanate composition alone has low hardness, good flexibility and transparency, low stress at 140% elongation, high elongation and tensile fracture stress, and excellent bending resistance, and an adhesive resin sheet with excellent adhesion, curability and transparency is obtained.

In contrast, as shown in Table 4, in the polyisocyanate compositions PA-b1 to PA-b5 (Comparative Examples 1 to 5) derived from diisocyanate and polyols not having the above-mentioned properties, it is not possible to obtain the hardness and transparency of the cured film 1 formed by curing the polyisocyanate composition alone, the stress, elongation and tensile fracture stress when the elongation is 140% when the cured film 2 is made, and the adhesion, curability and transparency when the adhesive resin sheet is made are all excellent.

[Industrial availability]

According to the polyisocyanate composition of this embodiment, a polyisocyanate composition can be provided, which can obtain a cured film formed by curing the polyisocyanate composition alone, which has good softness and transparency, and excellent elongation and tensile fracture stress, as well as an adhesive resin composition and an adhesive resin sheet with excellent adhesion, curability and transparency. In addition, the present invention can provide a laminated film having the above-mentioned adhesive resin sheet.

Claims (23)

A polyisocyanate composition is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and at least one polyester polyol selected from the group consisting of a difunctional polyester polyol (A) having a number average molecular weight Mn of 500 or more and a trifunctional or higher polyester polyol (B) having a number average molecular weight Mn of 500 or more, wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyester polyol is 1.5 or more and 30.0 or less, and the weight average molecular weight of the polyisocyanate composition is 3000 or more and 800000 or less. As in claim 1, the polyisocyanate composition, wherein the average number of isocyanate functional groups of the polyisocyanate composition is greater than 2.0 and less than 6.0. The polyisocyanate composition of claim 1 or 2, wherein the isocyanate group content of the polyisocyanate composition is greater than 1.0 mass % and less than 8.7 mass %. The polyisocyanate composition of claim 1 or 2, wherein the content of the polyester polyol (A) is 0.1 to 900 parts by mass relative to 100 parts by mass of the diisocyanate, and the content of the polyester polyol (B) is 0.1 to 900 parts by mass relative to 100 parts by mass of the diisocyanate. The polyisocyanate composition of claim 1 or 2, wherein the polyester polyol is polycaprolactone polyol. For example, the polyisocyanate composition of claim 1 or 2 is applied on glass and stored in an environment of 23°C and 65% humidity for 168 hours to form a cured film with a thickness of 40 μm, and a Koenig hardness of less than 60 times in an environment of 23°C. The polyisocyanate composition of claim 6, wherein the haze value measured by a haze meter when the above-mentioned cured film having a film thickness of 40 μm is attached to a glass having a haze value of 0.1% is less than 3.0%. A cured film comprising a polyisocyanate composition as claimed in claim 1 or 2 and a polyol resin composition having a glass transition temperature of 0°C or higher and 100°C or lower, wherein the elongation in a tensile test measured at a speed of 20 mm/min is 140% or higher, the stress at 140% is 25.0 MPa or lower, and the tensile fracture stress is 1.2 times or more of the stress at 140% above. For example, in the cured film of claim 8, the content of the polyisocyanate composition is not less than 0.01 parts by mass and not more than 200 parts by mass relative to 100 parts by mass of the polyol. An adhesive resin composition comprising a polyisocyanate composition as claimed in claim 1 or 2, and a polymer containing a crosslinking functional group having a glass transition temperature of 0.0°C or less. As in claim 10, the adhesive resin composition, wherein the polymer containing the cross-linking functional group is an acrylic polymer or a urethane polymer. As in claim 10, the adhesive resin composition, wherein the polymer containing crosslinking functional groups is obtained by copolymerizing a polymerizable (meth) acrylic monomer having a crosslinking functional group and a (meth) acrylic ester monomer having an ester terminal with a carbon number of 1 to 18, and the glass transition temperature Tg is above -75.0℃ and below 0.0℃. The adhesive resin composition of claim 10, wherein the weight average molecular weight of the polymer containing the crosslinking functional group is 1.0×10 ⁵ or more and 5.0×10 ⁶ or less. As in claim 10, the adhesive resin composition, wherein the cross-linking functional group is selected from at least one of the group consisting of hydroxyl, epoxy, cyclobutyl, carboxyl, vinyl, and amino. As in claim 10, the adhesive resin composition, wherein the content of the polyisocyanate composition is not less than 0.01 parts by mass and not more than 20.00 parts by mass relative to 100 parts by mass of the polymer containing the crosslinking functional group. An adhesive resin sheet is formed by hardening the adhesive resin composition of claim 10 by heat or light. As in claim 16, the adhesive resin sheet has a thickness of not less than 1 μm and not more than 1000 μm. For example, the adhesive resin sheet in claim 16 has a gel fraction of 20.0% by mass and less than 99.9% by mass. For example, the adhesive resin sheet of claim 16 has a 180-degree peeling adhesion measured at 23°C at a speed of 300 mm/min of not less than 0.05 N/20 mm and not more than 65.00 N/20 mm. For example, the adhesive resin sheet of claim 16, wherein the adhesive resin sheet with a thickness of 50 μm is attached to glass with a haze value of 0.1% and the haze value measured by a haze meter is less than 2.0%. A laminated film, which is a film substrate laminated on at least one surface of the adhesive resin sheet as claimed in claim 16. The laminated film of claim 21, wherein the film substrate is at least one selected from the group consisting of polyester resins, acetate resins, polyether sulfide resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and triacetyl cellulose resins. The multilayer film of claim 21, wherein the multilayer film is used for optical purposes.