JP5737180B2 - Unsaturated urethane oligomer, curable resin composition, transparent laminate and method for producing the same - Google Patents

Description

  The present invention relates to a flame retardant unsaturated urethane oligomer suitable for a method for producing a transparent laminate by curing a curable resin composition sandwiched between a pair of transparent substrates, and a curing containing the unsaturated urethane oligomer. The present invention relates to a curable resin composition, a transparent laminate having a cured resin layer composed of a cured product of the curable resin composition, and a method for producing a transparent laminate using the curable resin composition.

  As a transparent laminate having a pair of transparent substrates and an adhesive resin layer sandwiched between the transparent substrates, a laminated glass in which a pair of glass plates are integrated via an adhesive resin layer is known. . The laminated glass is used as a windshield for automobiles because broken glass fragments adhere to the film-like adhesive resin layer and do not scatter. Further, the laminated glass is used as a window glass for buildings (safety glass, crime prevention glass, fire prevention safety glass, etc.) because it is difficult to penetrate and has excellent strength. Therefore, when used as a window glass, the adhesive resin layer may be required to have good flame retardance in addition to excellent transparency.

  The fire safety glass is a glass that functions as a fire door in the event of a fire and functions as a safety glass in normal times. Usually, the resin material used for the adhesive resin layer of laminated glass gradually decomposes into low molecular weight substances when the decomposition temperature is reached. If the temperature that decomposes into volatile substances is higher than the ignition temperature of the volatile substances that are generated, it will ignite and ignite. Therefore, the resin material of the adhesive resin layer for fire safety safety glass includes a resin material that suppresses the oxidation reaction of the decomposition product, a resin material that does not volatilize even if the decomposition product is generated, and is crosslinked simultaneously with thermal decomposition. It is necessary to use a resin material that carbonizes by causing a reaction or a cyclization reaction, that is, a resin material having high flame retardancy.

The following are proposed as laminated glass using a resin material having high flame retardancy as the resin material of the adhesive resin layer.
(1) Fire safety glass using a fluorine-containing copolymer as a resin material for the adhesive resin layer (Patent Document 1).
(2) Laminated glass obtained by adding a phosphorus-based flame retardant to the resin material of the adhesive resin layer (Patent Document 2).

However, in the fireproof safety glass (1), the flame retardance is improved, but the adhesion between the glass plate and the adhesive resin layer is insufficient. Therefore, a haze value becomes high and it is difficult to use it as a window glass.
In the laminated glass of (2), since the phosphorus-based flame retardant is not easily mixed with the resin material of the adhesive resin layer, the transparency is impaired or the flame retardancy is not uniform. Moreover, in order to express a flame retardance, it is necessary to increase the addition amount of a phosphorus flame retardant. However, if the amount of phosphorus-based flame retardant added is large, the mechanical properties such as the strength of the adhesive resin layer are impaired, or the added flame retardant migrates inside the adhesive resin layer over time. Problems occur.

In addition, as a resin material expected to be flame retardant, a urethane prepolymer composition using a phosphorus-containing flame retardant polyol as a raw material is disclosed (Patent Document 3).
However, when this urethane prepolymer composition is used for the adhesive resin layer of laminated glass, there is a concern about durability.

Moreover, the following method is known as a manufacturing method of a laminated glass.
(I) A method of producing a laminated glass by sandwiching an adhesive resin film between a pair of transparent substrates and thermocompression bonding the laminate.
(Ii) A method of manufacturing a laminated glass by injecting a liquid curable resin between a pair of transparent substrates whose periphery is sealed, and then curing the curable resin (Patent Document 4).

The method (ii) has a wider variety of curable resins than the method (i), and it is easy to obtain a cured product having various physical properties according to the purpose, and an easily curable resin (especially a photocurable resin). ) Can be used to simplify the manufacturing process.
However, the method (ii) has a drawback that bubbles tend to remain in the resin when the curable resin is injected.

As a method for preventing the generation of bubbles, a vacuum lamination method is known. For example, the following method is known as a method for producing laminated glass by the reduced pressure lamination method.
(Iii) A layer of the photocurable resin composition is formed on one transparent substrate, and another transparent substrate is stacked on the layer of the photocurable resin composition under reduced pressure to form a pair of transparent A method for producing a laminated glass, in which a photocurable resin composition is sealed between substrates and then photocured under atmospheric pressure (Patent Document 5).

As a photocurable resin composition, a photocurable resin composition containing an unsaturated urethane oligomer has been proposed (Patent Document 5). Moreover, the photocurable resin composition containing an unsaturated urethane oligomer is known also as a photocurable resin composition suitable for the method of (iii) (patent document 6).
In the photocurable resin composition containing an unsaturated urethane oligomer, the characteristics of the cured product can be adjusted by using an unsaturated urethane oligomer and various monomers in combination. However, the conventional photocurable resin composition cannot obtain a cured product having good flame retardancy.

Japanese Patent Application Laid-Open No. 08-132560 JP 2007-261837 A Japanese Patent Laid-Open No. 11-263906 JP 2005-041747 A International Publication No. 2008/081838 International Publication No. 2009/016943

  The present invention provides an unsaturated urethane oligomer and a curable resin composition capable of obtaining a cured product having excellent transparency and flame retardancy. Moreover, the curable resin composition used for the method of manufacturing a transparent laminated body is provided. Furthermore, the transparent laminated body which is excellent in transparency and excellent in a flame retardance, and its manufacturing method are provided.

The present invention is the following [1] to [1 3 ].
[1] Reaction product of the following polyol component (A1), polyisocyanate compound (A2), and unsaturated hydroxy compound (A3) below, and an average of 2 to 4 curable functional groups per molecule An unsaturated urethane oligomer (A) having a phosphorus content of 1 to 7% by mass.
Polyol component (A1): A polyol component containing the following polyol (a1) and the following polyol (a2) .
Polyol (a1): A polyol having 2 to 3 hydroxyl groups per molecule, a hydroxyl value of 35 to 150 mgKOH / g, and having a phosphorus atom in the molecule.
Polyol (a2): A polyoxyalkylene polyol having 2 hydroxyl groups per molecule and a hydroxyl value of 20 to 120 mgKOH / g and having no phosphorus atom in the molecule.
Unsaturated hydroxy compound (A3): A compound having the following curable functional group and hydroxyl group.
Curable functional _{group: CH 2 = C (R)} C (O) O- ( wherein, R is a hydrogen atom or a methyl group).

[2] The unsaturated urethane oligomer (A ) according to [1], wherein the ratio of the polyol (a2) is 0.2 to 4 mol with respect to 1 mol of the polyol (a1 ).

[3] A curable resin composition comprising the unsaturated urethane oligomer (A) of [1] or [2].
[4] The curable resin composition according to [3], which is a curable resin composition used in a method for producing a transparent laminate by curing a curable resin composition sandwiched between a pair of transparent substrates.
[5] The curable resin composition according to [4], further including the following monomer (B).
Monomer (B): a compound represented by CH ₂ ═C (R) C (O) O—R ² (wherein R is a hydrogen atom or a methyl group, and R ² has 1 to 1 hydroxyl groups) 2 and a hydroxyalkyl group having 3 to 4 carbon atoms).

[6] The curable resin composition of [4] or [5], further comprising the following monomer (C).
Monomer (C): a compound represented by CH ₂ ═C (R) C (O) O—R ³ (wherein R is a hydrogen atom or a methyl group, and R ³ has 8 to 8 carbon atoms) 22 alkyl groups).
[7] The curable resin composition of [4] to [6], further comprising a photopolymerization initiator (D).
[8] The curable resin composition according to [4] to [7], wherein the phosphorus content in the curable resin composition (100% by mass) is 0.1 to 5% by mass.

[9] A transparent laminate having a pair of transparent substrates and a cured resin layer sandwiched between the transparent substrates, wherein the cured resin is a curable resin composition according to [4] to [8]. A transparent laminate that is a cured product of the above.
[10] The transparent laminate according to [9], wherein at least one of the pair of transparent substrates is a glass plate.

[11] In a reduced-pressure atmosphere, a sealed space containing the curable resin compositions [4] to [8] is formed between the pair of transparent substrates, and the pair of transparent substrates and the pair of transparent substrates A first step of producing a laminated precursor having the curable resin composition sealed in between, and the laminated precursor is placed in an atmosphere having a pressure higher than the reduced-pressure atmosphere, and the curing is performed in the atmosphere. The manufacturing method of a transparent laminated body which has a 2nd process of hardening an adhesive resin composition.
[12] The method according to [11], wherein the reduced-pressure atmosphere is a pressure atmosphere of 100 Pa or less, and the atmosphere having a higher pressure than the reduced-pressure atmosphere is an atmospheric pressure atmosphere.
[13] The curable resin composition is a photocurable resin composition, and in the second step, the laminated precursor is irradiated with light to cure the curable resin composition. [11] or [12 ] Manufacturing method.

According to the unsaturated urethane oligomer of the present invention, a cured product having excellent transparency and flame retardancy can be obtained.
According to the curable resin composition of the present invention, a cured product having excellent transparency and flame retardancy can be obtained.
The transparent laminate of the present invention is excellent in transparency and flame retardancy.
According to the method for producing a transparent laminate of the present invention, a transparent laminate having excellent transparency and excellent flame retardancy can be produced.

It is sectional drawing which shows 1 process in manufacture of a transparent laminated body.

In this specification, the curable functional group represented by CH ₂ ═C (R) C (O) O— (wherein R is a hydrogen atom or a methyl group) is an acryloyloxy group (where R is a hydrogen atom). Or a methacryloyloxy group (when R is a methyl group), and the group represented by the formula is also referred to as a (meth) acryloyloxy group. Similarly, “(meth) acrylate” is used as a general term for “acrylate” and “methacrylate”.

<Unsaturated urethane oligomer>
The unsaturated urethane oligomer (A) of the present invention is a urethane (meth) acrylate oligomer having an average of 2 to 4 curable functional groups per molecule and a phosphorus content of 1 to 6% by mass.
Curable functional _{group: CH 2 = C (R)} C (O) O- ( wherein, R is a hydrogen atom or a methyl group).

  The unsaturated urethane oligomer (A) is suitable as one component of a curable resin composition used in a method for producing a transparent laminate by curing a curable resin composition sandwiched between a pair of transparent substrates. It is. Since the unsaturated urethane oligomer (A) has a phosphorus atom in the molecule, the cured product has flame retardancy.

  The average number of curable functional groups per molecule of the unsaturated urethane oligomer (A) is 2 to 4, and preferably 2 to 3. If the average number of curable functional groups is 2 or more, a crosslinked structure can be introduced into a part of the cured resin layer, heat resistance is increased, and the cured resin layer is less likely to flow and deform when exposed to high temperatures. If the average number of curable functional groups is 4 or less, the crosslink density will not be too high, the flexibility of the cured resin layer will be good, and the impact resistance will be good.

  The average number of curable functional groups per molecule of the unsaturated urethane oligomer (A) is the number of hydroxyl groups of the polyol component (A1), the number of isocyanate groups of the polyisocyanate compound (A2), and the curability of the unsaturated hydroxy compound (A3). It is adjusted by the number of functional groups and the number of hydroxyl groups. Diisocyanate having 2 isocyanate groups is preferable as the polyisocyanate compound (A2), and unsaturated monool having 1 curable functional group is preferable as the unsaturated hydroxy compound (A3). The average number of curable functional groups per molecule of the obtained unsaturated urethane oligomer (A) is usually substantially the same as the average number of hydroxyl groups per molecule of the polyol component (A1). For example, by using only a diol as the polyol component (A1), an unsaturated urethane oligomer (A) having an average number of curable functional groups per molecule of 2 can be obtained. Similarly, by using diol and triol as the polyol component (A1), an unsaturated urethane oligomer (A) having an average curable functional group number between 2 and 3 is obtained, and only triol is obtained as the polyol component (A1). When used, an unsaturated urethane oligomer (A) having an average number of curable functional groups of 3 is obtained.

A plurality of curable functional groups present in one molecule may be the same or different. However, usually, when having a plurality of curable functional groups in one molecule, it is preferable that they have the same curable functional group.
The curable functional group in the unsaturated urethane oligomer (A) is preferably an acryloyloxy group. The curable functional group in the unsaturated urethane oligomer (A) tends to be less reactive as the unsaturated urethane oligomer (A) has a higher molecular weight, and when used in combination with a relatively low molecular weight compound, both cure. In order to reduce the difference in the reactivity of the functional group, it is preferable that the reactivity of the curable functional group in the unsaturated urethane oligomer (A) is high. Therefore, the curable functional group in the unsaturated urethane oligomer (A) is preferably an acryloyloxy group having a higher reactivity than the methacryloyloxy group.

  Phosphorus content in unsaturated urethane oligomer (A) (100 mass%) is 1-7 mass%, and 1-4 mass% is preferable. When the phosphorus content is 1% by mass or more, a sufficient flame retardant effect can be obtained. When the phosphorus content is 7% by mass or less, there is no generation of heterogeneous oligomers due to high molecular weight (gelation) of oligomers or lowering of compatibility during the production of unsaturated urethane oligomer (A), and curing. Since the cured | curing material obtained by hardening | curing an adhesive composition has sufficient transparency, it is preferable.

The unsaturated urethane oligomer (A) is a reaction product of the polyol component (A1), the polyisocyanate compound (A2), and the unsaturated hydroxy compound (A3). Examples of a method for obtaining the reaction product include the following: The method of (1)-(3) is mentioned.
(1) A method in which a polyol component (A1), a polyisocyanate compound (A2), and an unsaturated hydroxy compound (A3) are simultaneously reacted.
(2) After reacting the polyisocyanate compound (A2) and the unsaturated hydroxy compound (A3) in a stoichiometrically excessive condition with an isocyanate group, the resulting reaction product is further reacted with a polyol component (A1). How to make.
(3) After reacting the polyol component (A1) and the polyisocyanate compound (A2) in a stoichiometrically excessive condition with an isocyanate group being excessive, the resulting reaction product is further reacted with an unsaturated hydroxy compound (A3). How to make.

Although the method (1) is easy, variations in the molecular weight and viscosity of the unsaturated urethane oligomer (A) are easily observed, which is not industrially preferable.
In the method (2), when the number of hydroxyl groups in the polyol component (A1) is 3 or more, an ultrahigh molecular weight product (gel component) is hardly generated.
The method (3) is industrially preferable because a qualitative unsaturated urethane oligomer (A) can be obtained constantly.

Examples of the method (3) include a method having the following step (3-1) and step (3-2).
(3-1) If necessary, the polyol component (A1) and the polyisocyanate compound (A2) are reacted in a stoichiometrically excessive condition with an isocyanate group in the presence of a urethanization catalyst to obtain an isocyanate group-terminated urethane prepolymer. Obtaining.
(3-2) A step of reacting the unsaturated hydroxy compound (A3) with an isocyanate group at the terminal of the urethane prepolymer in the presence of a polymerization inhibitor as necessary.

Step (3-1):
Examples of the urethanization catalyst include cobalt naphthenate, zinc naphthenate, zinc 2-ethylhexanoate, dibutyltin dilaurate, tin 2-ethylhexanoate, triethylamine, 1,4-diabicyclo [2.2.2] octane, and the like. It is done.
The ratio of the polyol component (A1) and the polyisocyanate compound (A2) is preferably such that the molar ratio of isocyanate group: hydroxyl group is 1.2: 1-3: 1, Is more preferred. The reaction temperature is preferably a temperature in a normal urethanization reaction, that is, 30 to 90 ° C.

Step (3-2):
Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-hydroquinone, o-nitrotoluene and the like. The amount of the polymerization inhibitor is preferably 50 to 5,000 ppm with respect to the unsaturated hydroxy compound (A3).
The ratio of the urethane prepolymer and the unsaturated hydroxy compound (A3) is preferably such that the molar ratio of isocyanate group: hydroxyl group is 1: 1 to 1: 1.5. The reaction temperature is preferably 30 to 90 ° C.

(Polyol component (A1))
The polyol component (A1) is a polyol component containing a polyol (a1) having a phosphorus atom in the molecule as an essential component, preferably further containing a polyol (a2), and if necessary, another polyol (a3). May be included.

  The phosphorus content in the polyol component (A1) (100% by mass) is more than 1% by mass, preferably 10% by mass or less, and more preferably 1.1 to 8.5% by mass. By using the polyol component (A1) having a phosphorus content exceeding 1% by mass, the phosphorus content in the unsaturated urethane oligomer (A) can be made 1% by mass or more. Although the polyol component (A1) having a phosphorus content exceeding 10% by mass can be used, the compatibility with other components may be lowered, and the compatibility can be reduced by setting the phosphorus content to 10% by mass or less. It can be set as a favorable polyol component (A1).

(Polyol (a1))
The polyol (a1) is a polyol having 2 to 3 hydroxyl groups per molecule, a hydroxyl value of 35 to 150 mgKOH / g, and having a phosphorus atom in the molecule. A polyol (a1) may be used individually by 1 type, and may use 2 or more types together.

The polyol (a1) can be obtained as a commercial product. The following are mentioned as this commercial item.
“FC450” (number of hydroxyl groups: 2, hydroxyl value: 450 mgKOH / g, phosphorus content: 7.2 mass%) manufactured by Adeka Corporation,
“Weston 430” manufactured by Weston Chemical Co., Ltd. (number of hydroxyl groups: 3, hydroxyl value: 395 mg KOH / g, phosphorus content: 12.0 mass%),
"Nonen R0412-15" (number of hydroxyl groups: 2, hydroxyl value: 40 mgKOH / g, phosphorus content: 11.0 mass%) manufactured by Maruhishi Oil Chemical Co., Ltd.
“Nonen R0811-9” manufactured by Maruhishi Oil Chemical Co., Ltd. (number of hydroxyl groups: 2, hydroxyl value: 142 mgKOH / g, phosphorus content: 12.0% by mass),
“OP550” manufactured by Clariant (hydroxyl number: 2, hydroxyl value: 145 mg KOH / g, phosphorus content: 17.0% by mass), etc.

  The number of hydroxyl groups per molecule of the polyol (a1) is 2 to 3, and 2 is preferable. If the number of hydroxyl groups per molecule of the polyol (a1) is 2 to 3, an unsaturated urethane oligomer (A) having an average number of curable functional groups per molecule of 2 to 4 can be easily obtained.

The hydroxyl value of the polyol (a1) is 35 to 150 mgKOH / g, preferably 40 to 145 mgKOH / g. If the hydroxyl value of the polyol (a1) is 35 mgKOH / g or more, the molecular weight of the polyol (a1) does not become too large, so the viscosity of the polyol (a1) does not become too large, and there is no problem in workability. When the hydroxyl value of the polyol (a1) is 145 mgKOH / g or less, the compatibility with the monomer (B) is improved and the transparency of the cured product is improved.
The hydroxyl value of the polyol (a1) is measured according to JIS K1557-1 (2007 edition). The same applies to the hydroxyl value of other polyols.

(Polyol (a2))
The polyol (a2) is a polyoxyalkylene polyol having 2 hydroxyl groups per molecule and a hydroxyl value of 20 to 120 mgKOH / g and having no phosphorus atom in the molecule.

The polyol (a2) is a polyol having a polyoxyalkylene chain comprising an oxyalkylene group, and is preferably a polyoxyalkylene polyol obtained by ring-opening addition polymerization of a monoepoxide as an initiator in the presence of a catalyst.
A polyol (a2) may be used individually by 1 type, and may use 2 or more types together.

  Examples of the catalyst include diethyl zinc, iron chloride, metalloporphyrin, double metal cyanide complex, cesium compound, alkali (earth) metal compound, and double metal cyanide complex is preferable. When a polyoxyalkylene polyol having a low hydroxyl value is obtained by reacting propylene oxide with a general-purpose alkali metal compound catalyst (potassium hydroxide, etc.), the isomerization reaction of propylene oxide easily occurs and the degree of unsaturation increases. . A cured product containing an unsaturated urethane oligomer (A) obtained using a polyoxyalkylene polyol having a high degree of unsaturation may have insufficient mechanical properties. The unsaturation degree of the polyol (a2) is preferably 0.05 meq / g or less.

  As the double metal cyanide complex, a complex mainly composed of zinc hexacyanocobaltate is preferable, and an ether and / or alcohol complex of zinc hexacyanocobaltate is particularly preferable. Examples of the ether and / or alcohol complex of zinc hexacyanocobaltate include those described in JP-B-46-27250. As the ether, ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether and the like are preferable, and glyme is particularly preferable from the viewpoint of easy handling at the time of producing the complex. As the alcohol, tert-butanol, tert-butyl cellosolve and the like are preferable.

  The number of active hydrogens in the initiator is 2. The active hydrogen means an active hydrogen atom that can react with a monoepoxide, such as a hydrogen atom of a hydroxyl group or a hydrogen atom of an amino group. As the active hydrogen, a hydrogen atom of a hydroxyl group is preferable. Therefore, a polyhydroxy compound having 2 hydroxyl groups is preferable as the initiator. As the initiator, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, polyol (a2) obtained by reacting these with alkylene oxide And lower molecular weight polyoxyalkylene polyols. When a double metal cyanide complex is used, the molecular weight of the initiator is preferably 500 to 1,500. An initiator may be used individually by 1 type and may use 2 or more types together.

  Monoepoxide is a compound having one epoxy ring. Examples of the monoepoxide include alkylene oxide, glycidyl ether, glycidyl ester and the like, and alkylene oxide is preferable. Examples of the alkylene oxide include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, and the like, and ethylene oxide and propylene oxide are preferable. A monoepoxide may be used individually by 1 type and may use 2 or more types together. When two or more kinds of monoepoxides are used in combination, any polymerization method of block polymerization and random polymerization may be used, and both block polymerization and random polymerization may be combined.

The polyol (a2) is preferably a polyoxypropylene polyol obtained using only propylene oxide as a monoepoxide, or a poly (oxypropylene / oxyethylene) polyol obtained using propylene oxide and a small amount of ethylene oxide as a monoepoxide.
Examples of the polyoxyalkylene polyol other than the polyoxyalkylene polyol obtained by reacting a monoepoxide with an initiator include polyoxytetramethylene polyol.

  The number of hydroxyl groups per molecule of the polyol (a2) is 2. If the number of hydroxyl groups per molecule of the polyol (a2) is 2, an unsaturated urethane oligomer (A) having an average curable functional group number of 2 to 4 per molecule can be easily obtained.

  The hydroxyl value of the polyol (a2) is 20 to 120 mgKOH / g. If the hydroxyl value is within this range, the molecular weight of the polyol (a2) is not too large and the viscosity can be suppressed, which is industrially useful. When the hydroxyl value of the polyol (a2) is 20 mgKOH / g or more, the compatibility with the polyol (a1) is good, and the cured product obtained by curing the curable composition has sufficient transparency. When the hydroxyl value of the polyol (a2) is 120 mgKOH / g or less, the compatibility with the monomer (B) and the like is good, and the cured product has sufficient transparency.

  The proportion of the polyol (a2) is adjusted so that the phosphorus content in the polyol component (A1) (100% by mass) is 1 to 7% by mass. The proportion of the polyol (a2) is preferably from 0.2 to 4 mol, more preferably from 0.4 to 2.5 mol, per 1 mol of the polyol (a1). If the ratio of a polyol (a2) is this range, it can be compatible with transparency and flame retardance of the hardened | cured material obtained by hardening | curing a curable composition. When the ratio of the polyol (a2) is 0.2 mol or more, the compatibility with the monomer (B) is good, and the cured product has sufficient transparency. When the ratio of the polyol (a2) is 4 mol or less, the cured product has sufficient flame retardancy.

(Polyol (a3))
The polyol (a3) is a polyol that is neither the polyol (a1) nor the polyol (a2). Examples of the polyol (a3) include polyoxyalkylene polyols having 3 or more hydroxyl groups. Moreover, polyols, such as a polyester polyol, a polycaprolactone polyol, a polycarbonate polyol, a polybutadiene polyol, are mentioned.

  The polyol (a3) is not an essential component, and the proportion of the polyol (a3) is adjusted so that the phosphorus content in the polyol component (A1) (100% by mass) is 1 to 7% by mass. When using a polyol (a3), the mass ratio in a polyol component (A1) shall be a small quantity. The proportion of the polyol (a3) is preferably 25% by mass or less, more preferably 10% by mass or less, out of 100% by mass of the polyol component (A1).

(Polyisocyanate compound (A2))
The polyisocyanate compound (A2) is obtained by modifying alicyclic polyisocyanates, aliphatic polyisocyanates, aromatic ring-containing aliphatic polyisocyanates having an average number of isocyanate groups of 2 or more per molecule, and aromatic ring-containing aliphatic polyisocyanates. Examples thereof include modified polyisocyanates. An aromatic polyisocyanate having an isocyanate group bonded to an aromatic ring is preferably not used because it has a high possibility of causing yellowing of a cured product.

  2-4 are preferable and, as for the average number of isocyanate groups per molecule of a polyisocyanate compound (A2), 2 is especially preferable. That is, as the polyisocyanate compound (A2), diisocyanate is preferable. A polyisocyanate compound (A2) may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the polyisocyanate compound (A2) include diisocyanates such as isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, prepolymer modified products, nurate modified products, urea modified products, and carbodiimide modified products of the diisocyanate. And isophorone diisocyanate and hexamethylene diisocyanate are particularly preferable.

(Unsaturated hydroxy compound (A3))
The unsaturated hydroxy compound (A3) is a compound having a curable functional group and a hydroxyl group, and two or more curable functional groups may be present in one molecule, and two or more hydroxyl groups are present in one molecule. It may be. In order to produce an unsaturated urethane oligomer (A) having an average of 2 to 4 curable functional groups per molecule, a compound having one curable functional group and one hydroxyl group in one molecule is preferable.

  As the unsaturated hydroxy compound (A3), a hydroxyalkyl (meth) acrylate having a hydroxyalkyl having 1 to 10 carbon atoms is preferable, and a hydroxyalkyl (meth) acrylate having a hydroxyalkyl having 1 to 5 carbon atoms is more preferable. . In order to obtain a highly reactive unsaturated urethane oligomer (A), the curable functional group is preferably an acryloyloxy group. Accordingly, the unsaturated hydroxy compound (A3) is more preferably a hydroxyalkyl acrylate having a hydroxyalkyl having 1 to 5 carbon atoms.

  Specific examples of the unsaturated hydroxy compound (A3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4 -Hydroxybutyl (meth) acrylate, pentanediol mono (meth) acrylate, hexanediol mono (meth) acrylate and the like are mentioned, and 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable, Hydroxyethyl acrylate and 2-hydroxypropyl acrylate are particularly preferable. An unsaturated hydroxy compound (A3) may be used individually by 1 type, and may use 2 or more types together.

<Curable resin composition>
The curable resin composition of the present invention is a composition containing an unsaturated urethane oligomer (A). The curable resin composition sandwiched between a pair of transparent substrates, which will be described later, is cured to form a transparent laminate. It is suitable as a curable resin composition used in the production method.

(Other ingredients)
The curable resin composition containing the unsaturated urethane oligomer (A) can be used for adhesives, coating agents, and other applications. Various additives can be added to the curable resin composition depending on the application. It is usually essential to add a curing agent for curing the curable resin composition, and a radical generator or a photopolymerization initiator is preferable as the curing agent. A curable resin composition containing a curing agent that generates radicals by heat is a thermosetting type, and a curable resin composition containing a photopolymerization initiator is a photocurable type.

  In the curable resin composition containing the unsaturated urethane oligomer (A), monomers such as a monomer (B) and other monomers (F) described later are blended for adjusting the physical properties of the cured product. It is preferable. As the monomer, a compound having 1 to 6 curable functional groups is preferable, and a compound having 1 to 2 curable functional groups is more preferable. In terms of obtaining a hard cured product, a compound having 3 to 6 curable functional groups is preferred. Moreover, a low viscosity compound is preferable as a monomer from the point which improves the applicability | paintability of curable resin composition. Monomers with low viscosity are sometimes referred to as reactive diluents. Furthermore, you may mix | blend curable compounds other than the said monomers, such as other below-mentioned unsaturated oligomer (E).

  Various additives that do not participate in the reaction may be added to the curable resin composition. As this additive, the below-mentioned additive (G) etc. are mentioned, for example. Moreover, in order to improve applicability | paintability, you may use a solvent as components other than the structural component of curable resin composition. The curable resin composition is applied using a solvent, and then the curable resin composition is cured by removing the solvent. However, since it is not preferable to have a volatile component as a curable resin composition suitable for the production of a transparent laminate described later, no solvent is used.

(Curable resin composition suitable for production of transparent laminate)
The curable resin composition used in the method for producing a transparent laminate by curing a curable resin composition sandwiched between a pair of transparent substrates according to the present invention comprises an unsaturated urethane oligomer (A) as an essential component. It is preferable that the monomer (B), the monomer (C), the photopolymerization initiator (D), and / or other unsaturated oligomers (E) are further contained, and if necessary, other monomers The body (F), additive (G), etc. may further be included.

  The unsaturated urethane oligomer (A) is preferably added so that the phosphorus content in the curable resin composition (100% by mass) is 0.1 to 5% by mass, and 0.1 to 3% by mass. It is more preferable to add so that it becomes. If phosphorus content is 0.1 mass% or more, the hardened | cured material obtained by hardening | curing curable resin composition can express a flame retardance. When the phosphorus content is 5% by mass or less, the cured product is not hard and brittle, and the impact resistance of the transparent laminate obtained by curing the curable resin composition sandwiched between the pair of transparent substrates is sufficient.

The unsaturated urethane oligomer (A) is preferably 10 to 100 parts by mass, more preferably 40 to 60 parts by mass, out of a total of 100 parts by mass of the components (A) to (C), (E) and (F). If unsaturated urethane oligomer (A) is 10 mass parts or more, the flame retardance of hardened | cured material will become favorable.
When including a monomer (B), 25-65 mass parts is preferable among the total 100 mass parts of (A)-(C), (E), and (F) component, and 35-50 mass parts is preferable. More preferred. When the monomer (B) is 65 parts by mass or less, the compatibility with the unsaturated urethane oligomer (A) is good, and the cured product obtained by curing the curable composition has sufficient transparency.

When the monomer (C) is included, 3 to 50 parts by mass is preferable and 5 to 25 parts by mass is preferable among the total 100 parts by mass of the components (A) to (C), (E) and (F). More preferred. If the ratio of a monomer (C) is 3 mass parts or more, the softness | flexibility of hardened | cured material can improve and the viscosity of curable resin composition can also be lowered | hung, and it is industrially useful.
When including a photoinitiator (D), 0.01-10 mass parts is preferable with respect to a total of 100 mass parts of (A)-(C), (E), and (F) component, and 0.0. 1-2.5 mass parts is more preferable.

When including other oligomer (E), 3-55 mass parts is preferable among 30 to 50 mass parts in total among 100 mass parts of a total of (A)-(C), (E), and (F) component. More preferred. When the ratio of the other oligomer (E) is 3 parts by mass or more, the flexibility of the cured product is improved and the viscosity of the curable resin composition can be lowered, which is industrially useful.
When other monomer (F) is included, 50 parts by mass or less is preferable and 40 parts by mass or less is preferable among the total 100 parts by mass of the components (A) to (C), (E) and (F). More preferred.
When the additive (G) is included, 5 parts by mass or less is preferable and 3 parts by mass or less is more preferable with respect to 100 parts by mass in total of the components (A) to (C), (E) and (F). .

(Monomer (B))
The monomer (B) is a compound represented by CH ₂ ═C (R) C (O) O—R ² , where R is a hydrogen atom or a methyl group, and R ² has 1 to ² hydroxyl groups. And a hydroxyalkyl group having 3 to 4 carbon atoms. The monomer (B) is effective as a component that increases the hydrophilicity of the cured product of the curable resin composition and improves the affinity between the cured product and the surface of the transparent substrate (glass plate). By using (B), the adhesion between the cured product and the transparent substrate is improved.

  The monomer (B) is a (meth) acrylate having a hydroxyalkyl group or a dihydroxyalkyl group, and is preferably a methacrylate in order to proceed the reaction with the unsaturated urethane oligomer (A) uniformly. That is, even if the curable functional group of the unsaturated urethane oligomer (A) is an acryloyloxy group, the reactivity is low, and when the curable functional group of the monomer (B) is an acryloyloxy group, both curable functional groups are present. There is a possibility that a difference in reactivity between groups becomes large and uniform curing cannot be obtained. Therefore, a combination in which the curable functional group of the unsaturated urethane oligomer (A) is an acryloyloxy group and the curable functional group of the monomer (B) is a methacryloyloxy group is preferable. A monomer (B) may be used individually by 1 type, and may use 2 or more types together.

When the number of hydroxyl groups of the monomer (B) is 2 or less, the cured product is hardly brittle. Therefore, the number of hydroxyl groups of R ² is 1 to 2, more preferably 1.
The number of carbon atoms in ^{R 2} of the monomer (B) is 3-4. When R ² has 3 or more carbon atoms, the compatibility with the unsaturated urethane oligomer (A) having a long chain structure is good, and a cured product obtained by curing the curable composition has sufficient transparency. When the carbon number of R ² is 4 or less, the hydroxyl group density becomes high and sufficient adhesion can be obtained.

  Examples of the monomer (B) include 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate and the like, and 2-hydroxybutyl methacrylate is preferable.

(Monomer (C))
The monomer (C) is a compound represented by CH ₂ ═C (R) C (O) O—R ³ (where R is a hydrogen atom or a methyl group, and R ³ has 8 to 22 carbon atoms) It is an alkyl group of For the same reason as the monomer (B), the monomer (C) is preferably methacrylate, but the monomer (C) has a higher molecular weight than the monomer (B), so it may be An acrylate may also be used. A monomer (C) may be used individually by 1 type, and may use 2 or more types together.

  When the curable resin composition contains the monomer (C), the elastic modulus of the cured product is lowered and the tear resistance is easily improved. Moreover, if carbon number of an alkyl group is 8 or more, there is little volatility and the glass transition temperature of hardened | cured material can be reduced. When the carbon number of the alkyl group is 22 or less, the alcohol component of the raw material can be easily obtained via a natural product and is more industrial.

  Examples of the monomer (C) include n-dodecyl methacrylate, n-octadecyl methacrylate, n-behenyl methacrylate and the like, and n-dodecyl methacrylate and n-octadecyl methacrylate are particularly preferable.

(Photopolymerization initiator (D))
When the curable resin composition of this invention contains a photoinitiator (D), it becomes a photocurable resin composition.
As the photopolymerization initiator (D), those which are excited by irradiation with visible light or ultraviolet light (wavelength 300 to 400 nm) and are activated to promote the curing reaction are preferable. A benzoin ether photopolymerization initiator, α-hydroxyalkyl Examples thereof include a phenone photopolymerization initiator and an acyl phosphine oxide photopolymerization initiator.

  Specific examples of the photopolymerization initiator (D) include benzophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, acetophenone, 3-methylacetophenone, benzoyl, benzoin isobutyl ether, benzoin Isopropyl ether, benzoin ethyl ether, anthraquinone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2- Hydroxy-2-methyl-1-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and the like, such as 1-hydroxycyclohexyl phenyl ketone, 1- [4- (2- Hydroxy Toxi) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, etc. are preferred, and they can be cured sufficiently even in a small amount. An acyl phosphine oxide-based photopolymerization initiator such as bis (2,4,6-trimethylbenzoyl) -phenyl phosphine oxide is particularly preferred from the viewpoint of curing the conductive resin composition. A photoinitiator (D) may be used individually by 1 type, and may use 2 or more types together.

(Other unsaturated oligomers (E))
The curable resin composition of the present invention may contain a small amount of an unsaturated oligomer (E) other than the unsaturated urethane oligomer (A) for the purpose of adjusting the viscosity of the composition and the physical properties of the cured product.
Other unsaturated oligomers (E) include urethane (meth) acrylate oligomers obtained using polyols that do not contain phosphorus atoms, poly (meth) acrylates of polyoxyalkylene polyols, poly (meth) acrylates of polyester polyols, and the like. Can be mentioned.

(Other monomer (F))
The curable resin composition of the present invention is a monomer (F) ((meth) acrylate other than the monomer (B) and the monomer (C) for the purpose of adjusting the physical properties of the resulting cured product. Etc.) may be included in a small amount. Examples of the other monomer (F) include poly (meth) acrylate of polyhydric alcohol.

  However, when manufacturing a transparent laminated body by the pressure reduction laminating method mentioned later, it is not preferable that curable resin composition contains a low boiling-point compound. In the method of injecting and curing a liquid curable resin composition between a pair of transparent substrates sealed at the periphery, even when injecting with a reduced pressure between the transparent substrates, it is exposed to a reduced pressure at the time of injection. Since the surface area of the curable resin composition is narrow and the degree of vacuum need not be so high, volatilization is a problem even if the curable resin composition contains a compound having a relatively low boiling point. There are few. On the other hand, in the reduced pressure laminating method, the curable resin composition is exposed to reduced pressure in a state where the curable resin composition spreads over almost the entire surface excluding the peripheral portion of the transparent substrate. Therefore, if the curable resin composition contains a low boiling point compound, The disappearance due to volatilization is severe, and the composition of the curable resin composition may change greatly. In addition, it becomes difficult to maintain a reduced pressure atmosphere at a required reduced pressure level due to volatilization of volatile compounds.

  Components that tend to have a low boiling point in the curable resin composition are mainly monomers. The monomer (B) is a hydroxyalkyl (meth) acrylate and has a sufficiently high boiling point. Further, the monomer (C) has a higher boiling point than the alkyl group having a large number of carbon atoms, even if it is an alkyl (meth) acrylate. Alkyl (meth) acrylates having a low carbon number of the alkyl group often have a low boiling point, and the curable resin composition containing such a low boiling point alkyl (meth) acrylate as another monomer (F) is: It cannot be used as a curable resin composition for producing a transparent laminate by a reduced pressure lamination method. The curable resin composition that can be used in the reduced pressure lamination method preferably does not contain a monomer having a normal pressure boiling point of 150 ° C. or lower, preferably 200 ° C. or lower.

(Additive (G))
Examples of the additive (G) include ultraviolet absorbers (benzotriazoles, hydroxyphenyltriazines, etc.), light stabilizers (hindered amines, etc.), pigments, dyes, metal oxide fine particles, fillers, and the like.

(Viscosity of curable resin composition)
Of the present invention, the viscosity of the curable resin composition used in the method for producing a transparent laminate, likewise the viscosity of the present invention curable resin composition which can be used in other applications, the viscosity V ₄₀ at 40 ° C. It is preferably 50 Pa · s or less. The viscosity V ₂₅ at 25 ° C. is preferably 0.05 Pa · s or more.
Viscosity is measured using an E-type viscometer (Toki Sangyo Co., Ltd., RE-85U). However, when the viscosity of the composition is 100 Pa · s or less, 1 ° 34 ′ × R24 is used as the rotor, and when the viscosity is higher than that, 3 ° × R9.7 is used as the rotor.

When the viscosity V ₄₀ is 50 Pa · s or less, the fluidity is good, and when used in the reduced pressure laminating method described later, bubbles that do not easily disappear in the curable resin composition are hardly generated. However, when the curable resin composition is used for an application in which a solvent can be used, the solvent is added to increase fluidity to perform application, etc., and then the curable resin composition obtained by removing the solvent is cured. Can be made. When V ₂₅ of the curable resin composition is 0.05 Pa · s or more, the physical properties of the cured product are improved.

  In the curable resin composition used in the method for producing the transparent laminate of the present invention described above, the specific unsaturated urethane oligomer (A) obtained by using the specific polyol component (A1) described above. Therefore, when the composition is cured, a cured product having excellent transparency and flame retardancy is obtained.

  It is preferable to use the curable resin composition of this invention as a curable resin composition for manufacturing the transparent laminated body mentioned later. However, the present invention is not limited to this application, and can be used for other applications as a curable resin, particularly as a photocurable resin. As other uses, a curable resin composition for producing a laminate having the same structure as the transparent laminate described later, wherein one transparent substrate is an opaque substrate or a transparent substrate having low transmittance of transmitted light. It is. An example of such a laminate is a solar cell module. In such a laminate, at least one substrate is transparent so that light necessary for curing the photocurable resin composition can be incident thereon. When the substrates on both sides are opaque, the thermosetting resin composition can be used for thermosetting, but even if the opaque substrate is opaque to visible light, for example against ultraviolet rays necessary for photocuring. If it is transparent, a photocurable resin composition can be used even if both surfaces are opaque substrates.

  As a transparent substrate with low light transmittance, a glass substrate on which a thin film solar cell is formed is used, and a layer made of a cured product of the curable resin composition of the present invention is formed between the glass substrate and a solar cell module Can be provided. By the joining layer which consists of hardened | cured material of the curable resin composition of this invention, a flame retardance performance can be provided to a solar cell module, and safety | security can be improved when installing in a building. As the thin film solar cell, a power generation layer made of thin film silicon or a compound semiconductor (such as copper-indium-gallium-selenium) can be used. A power generation layer made of thin film silicon can be provided on both glass substrates, or a thin film silicon substrate and a glass substrate on which a compound semiconductor thin film is formed can be combined and laminated. In the case of a solar cell module, both substrates such as a glass substrate may be transparent.

  Furthermore, a plurality of solar cell substrates made of single crystal silicon or microcrystalline silicon are arranged between a pair of glass substrates, and the solar cell substrate is interposed between the glass substrates by a cured product of the curable resin composition of the present invention. It can also be enclosed. One side of the glass substrate may be a waterproof resin sheet. Such a solar cell module has flame retardancy, and safety is improved when it is installed in a building. In addition, even if a part of the solar cell substrate to be encapsulated is defective and excessive current flows to generate heat, it is encapsulated by using the cured product of the curable resin composition of the present invention as the encapsulating resin. Since the resin has flame retardancy, safety can be improved.

<Transparent laminate>
The transparent laminate of the present invention has a pair of transparent substrates and a cured resin layer sandwiched between the transparent substrates. In addition, this transparent laminated body and this transparent substrate mean that it is transparent with respect to visible light.

Examples of the transparent substrate include a glass plate or a resin plate. If a glass plate is used, a laminated glass is obtained. If a polycarbonate plate is used as the resin plate, a lightweight transparent panel having high impact resistance can be obtained. Further, a glass plate and a resin plate may be used in combination.
The size of the transparent substrate is not particularly limited, but can be widely used as a transparent member to be installed in an opening for a building or a vehicle if it is a transparent substrate having at least one side of 300 mm or more, more preferably 600 mm or more. . In normal applications, a size of 4 m ² or less is appropriate.

The layer of the cured resin contained in the transparent laminate is a layer made of a cured product of the curable resin composition of the present invention.
The thickness of the cured resin layer is preferably 0.2 to 4.0 mm. When the thickness of the cured resin layer is 0.2 mm or more, the mechanical strength of the transparent laminate is good. When the thickness of the cured resin layer is 4.0 mm or less, the transparent laminate is excellent in transparency and can be used as a window glass.

  In the transparent laminate of the present invention described above, the cured resin layer sandwiched between the transparent substrates is made of a cured product of the curable resin composition of the present invention, and thus has excellent transparency and flame retardancy. Excellent in properties.

<Method for producing transparent laminate>
The transparent laminate of the present invention can be produced by a known production method (for example, a method of sandwiching a curable resin composition between a pair of transparent substrates and curing the curable resin composition). It is preferable to manufacture by a reduced pressure lamination method using a curable resin composition. The decompression lamination method itself is described in International Publication No. 2008/081838 and International Publication No. 2009/016943.

  The feature of the reduced pressure lamination method is that a curable resin composition layer is formed on one transparent substrate, and another transparent substrate is stacked on the curable resin composition layer in a reduced pressure atmosphere. The curable resin composition is hermetically sealed between the transparent substrates and then placed in a pressure atmosphere (usually an atmospheric pressure atmosphere) higher than the reduced-pressure atmosphere to cure the curable resin composition. For this reason, the manufacturing method of the transparent laminated body of this invention makes the following 1st process and 2nd process essential.

1st process: The said hardening which formed the sealed space which accommodated the curable resin composition inside between a pair of transparent substrates in a pressure-reduced atmosphere, and was sealed between a pair of transparent substrates and this pair of transparent substrates. The process of manufacturing the lamination | stacking precursor which has a conductive resin composition.
2nd process: The process of putting the said lamination | stacking precursor in the atmosphere whose pressure is higher than the said pressure reduction atmosphere, and hardening the said curable resin composition in the atmosphere.

The reduced pressure atmosphere in the first step is preferably a pressure atmosphere of 1 kPa or less, and more preferably a pressure atmosphere of 100 Pa or less. Further, if the pressure in the reduced-pressure atmosphere is too low, the curable resin composition such as a monomer may be volatilized. Therefore, the reduced-pressure atmosphere is preferably a pressure atmosphere of 1 Pa or more, and more preferably a pressure atmosphere of 10 Pa or more.
The atmosphere having a higher pressure than the reduced-pressure atmosphere in the second step is preferably a pressure atmosphere of 50 kPa or more, and more preferably a pressure atmosphere of 100 kPa or more. The pressure atmosphere in the second step is usually an atmospheric pressure atmosphere.
Hereinafter, the manufacturing method will be described by taking as an example the case where the atmosphere having a higher pressure than the reduced-pressure atmosphere is an atmospheric pressure atmosphere.

  In the first step, even if bubbles remain in the curable resin composition in the sealed space, the bubbles are likely to disappear before the curable resin composition is cured, and a cured resin layer having no bubbles is easily obtained. . When the laminated precursor formed in the first step is placed under atmospheric pressure, pressure is also applied to the curable resin composition in the sealed space due to the pressure from the transparent substrate under atmospheric pressure. On the other hand, since the inside of the bubbles in the curable resin composition is at the reduced-pressure atmospheric pressure in the first step, the volume of the bubbles is reduced by the pressure applied to the curable resin composition in the second step. When this gas dissolves in the curable resin composition, the bubbles disappear. In order to eliminate bubbles, it is preferable to hold the lamination precursor under atmospheric pressure for a while before the curable resin composition is cured. The holding time is preferably 5 minutes or more, but the holding time may be shorter when there are no bubbles or when the bubbles are very small and quickly disappear.

  In the first step, the reduced-pressure atmosphere is required at the stage of forming the sealed space, and is not required at the previous stage. For example, a sealing material having a predetermined thickness is provided around the periphery of one surface of one transparent substrate, and the curable resin composition is supplied to the surface of the transparent substrate in a region surrounded by the sealing material to be curable. When forming the layer of the resin composition, these steps can be performed in an atmospheric pressure atmosphere. The sealed space is preferably formed as follows.

  The transparent substrate having the layer of the curable resin composition obtained as described above and the other transparent substrate are put in a reduced pressure chamber to have a predetermined arrangement. That is, a transparent substrate having a layer of a curable resin composition was placed on a horizontal surface plate with the layer of the curable resin composition facing up, and the other transparent substrate was attached to the tip of a cylinder that could be moved up and down. It attaches to the lower surface of a horizontal surface plate, and both transparent substrates are located in parallel, without making the layer of curable resin composition contact the other transparent substrate. Thereafter, the decompression chamber is closed and evacuated, and the inside of the decompression chamber is set to a predetermined decompressed atmosphere. After the inside of the decompression chamber becomes a predetermined decompression atmosphere, the cylinder is operated and both transparent substrates are overlapped via the layer of the curable resin composition, and the curable resin is placed in the space surrounded by the both transparent substrates and the sealing material. The composition is sealed to form a laminated precursor. After forming the lamination precursor, the inside of the reduced pressure chamber is returned to the atmospheric pressure atmosphere, and the lamination precursor is taken out from the reduced pressure chamber.

  The adhesion strength between the transparent substrates and the sealing material may be such that no gas enters from the interface between the transparent substrate and the sealing material when the lamination precursor is placed under atmospheric pressure. For example, a layer of a pressure sensitive adhesive can be provided on the surface of the sealing material to adhere the transparent substrate and the sealing material. If necessary, a curable adhesive is provided at the interface between the transparent substrate and the sealing material, or the sealing material is formed of a curable resin to form a laminated precursor, and then taken out from the vacuum chamber or from the vacuum chamber. Thereafter, the adhesive strength between the transparent substrate and the sealing material can be increased by curing the curable adhesive or the curable resin.

  The second step is a step of placing the lamination precursor under atmospheric pressure and curing the curable resin composition. When the curable resin composition is a thermosetting curable resin, it is thermoset. More preferably, a photocurable resin composition is used as the curable resin composition and photocured. Photocuring can be performed by irradiating light from a light source such as an ultraviolet lamp through a transparent substrate. The light irradiation is preferably performed for 3 to 30 minutes. As described above, it is preferable to harden the curable resin composition after holding the laminated precursor for a while under atmospheric pressure. By curing the curable resin composition, the curable resin composition becomes a cured resin, and the transparent laminate as described above is obtained.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited only to these examples.
Examples 1 to 12 are examples, and examples 13 to 16 are comparative examples.

(Phosphorus content)
The phosphorus content in each sample was measured by atomic absorption spectrometry using an inductively coupled plasma emission spectrophotometer (Seiko Instruments, SPS3100).

(viscosity)
The viscosity V ₂₅ at 25 ° C. of the curable resin composition was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., RE-85U). However, when the viscosity of the composition was 100 Pa · s or less, 1 ° 34 ′ × R24 was used as the rotor, and when the viscosity was higher than that, 3 ° × R9.7 was used as the rotor.

(Transmittance)
The transmittance was measured as an evaluation of the transparency of the portion where the cured resin layer of the transparent laminate was present. The transmittance was measured according to ASTM D1003 using Hazeguard II (manufactured by Toyo Seiki Seisakusho).
The transmittance of the transparent laminate is preferably 90% or more from the viewpoint of clear visibility when used as a laminated glass, for example.

(Fire test)
Building standard law construction order Article 109-2 Act 2 Article 9 No. 2 (2) The technical standards specified in the government ordinance are provided in the electric furnace, and similar in smaller test specimens A fire test was conducted. A 100 × 100 mm laminated glass was prepared, and a portion of the glass on the non-heated surface was peeled off so that the cured resin layer could come into contact with air. One piece of the laminated glass is installed on the door surface of the electric furnace with the front door open so that the heating surface of the test body faces the inside of the thermostatic chamber, and the door surface of the electric furnace is closed. The heated surface was brought into contact with air. The temperature chamber was heated so that the temperature profile was almost the same as the temperature profile defined by the Cabinet Order of Article 109-2 of the Building Standards Act, Article 2, Item 9 of the Building Standards Act. In the temperature rising process for 20 minutes, the case where no flame was generated from the non-heated surface was evaluated as “pass”; the case where the flame was generated from the non-heated surface was determined as “fail”.

(Polyol (a1))
Polyol (c-1): “FC450” (number of hydroxyl groups: 2, hydroxyl value: 450 mgKOH / g, phosphorus content: 7.2 mass%) manufactured by Adeka Company.
Polyol (c-2): “Weston 430” manufactured by Weston Chemical Co., Ltd. (number of hydroxyl groups: 3, hydroxyl value: 395 mg KOH / g, phosphorus content: 12.0 mass%).
Polyol (c-3): “Nonen R0412-15” manufactured by Maruhishi Oil Chemical Co., Ltd. (number of hydroxyl groups: 2, hydroxyl value: 40 mgKOH / g, phosphorus content: 11.0% by mass).
Polyol (c-4): “Nonen R0811-9” manufactured by Maruhishi Oil Chemical Co., Ltd. (hydroxyl number: 2, hydroxyl value: 142 mgKOH / g, phosphorus content: 12.0% by mass).
Polyol (c-5): “OP550” manufactured by Clariant (number of hydroxyl groups: 2, hydroxyl value: 145 mg KOH / g, phosphorus content: 17.0 mass%).

(Polyol (a2))
Polyol (d-1): Zinc hexacyanocobaltate-glyme complex was used as a catalyst, propylene oxide was reacted with an initiator to deactivate the catalyst, and then potassium hydroxide was used as a catalyst to react with ethylene oxide. The catalyst was deactivated and purified to obtain a polyoxyalkylene polyol (hydroxyl number: 2, hydroxyl value: 28 mgKOH / g, oxyethylene group ratio: 24% by mass).
Polyol (d-2): Potassium hydroxide was used as a catalyst, propylene oxide was reacted with the initiator and purified to obtain a polyoxyalkylene polyol (hydroxyl number: 2, hydroxyl value: 112 mgKOH / g).

(Polyol component (A1))
Polyols (c-1) to (c-5) and polyols (d-1) to (d-2) are mixed at the molar ratio shown in Table 1, and polyol components (b-1) to (b-8) are mixed. )
The phosphorus content in the polyol components (b-1) to (b-8) was measured. The results are shown in Table 1. Moreover, the hues of the polyol components (b-1) to (b-8) were observed. The results are shown in Table 1.

[Example 1]
15.5 parts by mass (0.1 mol) of isophorone diisocyanate (hereinafter referred to as IPDI) is added to 100 parts by mass (0.05 mol) of the polyol component (b-3), and dibutyltin dilaurate (hereinafter DBTDL). In the presence of 0.01 part by mass of (A), the reaction was carried out at 80 ° C. for 4 hours to obtain a urethane prepolymer. To the urethane prepolymer, 0.05 part by mass of DBTDL and 0.05 part by mass of hydroquinone monomethyl ether (hereinafter referred to as HQME) are added, and 2-hydroxyethyl acrylate (hereinafter referred to as HEA) at 50 ° C. 8.0 parts by mass (0.1 mol) was added, stirred at 60 ° C., and reacted until the isocyanate groups disappeared while measuring the isocyanate group content by NCO titration according to JIS K1603-1. The urethane acrylate oligomer (e-1) was obtained.

  40 parts by mass of urethane acrylate oligomer (e-1), 40 parts by mass of 2-hydroxybutyl methacrylate (hereinafter referred to as HBMA), and 20 parts by mass of n-dodecyl methacrylate (hereinafter referred to as DMA) were mixed. 1 part by mass of 1-hydroxycyclohexyl phenyl ketone (hereinafter referred to as HCHPK) was added to prepare a photocurable resin composition.

[Example 2]
A urethane acrylate oligomer (e-2) was obtained in the same manner as in Example 1 except that the polyol (b-4) was used instead of the polyol (b-3) to prepare a photocurable resin composition.

[Example 3]
7.5 parts by weight (0.065 moles) of IPDI is added to 100 parts by weight (0.05 moles) of polyol (b-5) and reacted at 80 ° C. for 4 hours in the presence of 0.01 parts by weight of DBTDL. To obtain a urethane prepolymer. 0.05 parts by mass of DBTDL and 0.05 parts by mass of HQME are added to the urethane prepolymer, 5.0 parts by mass (0.03 mol) of HEA is added at 50 ° C., and the mixture is stirred at 60 ° C. While measuring the isocyanate group content by NCO titration according to K1603-1, the reaction was carried out until the isocyanate group disappeared to obtain a urethane acrylate oligomer (e-3).
40 parts by mass of urethane acrylate oligomer, 40 parts by mass of HBMA, and 20 parts by mass of DMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 4]
A urethane acrylate oligomer (e-4) was obtained in the same manner as in Example 3 except that the polyol (b-6) was used instead of the polyol (b-5) to prepare a photocurable resin composition.

[Example 5]
To 100 parts by mass (0.05 mol) of polyol (b-6), 10 parts by mass (0.06 mol) of IPDI was added and reacted at 80 ° C. for 4 hours in the presence of 0.01 part by mass of DBTDL. A urethane prepolymer was obtained. Add 0.05 parts by mass of DBTDL and 0.05 parts by mass of HQME to the urethane prepolymer, add 5.0 parts by mass (0.02 mol) of HEA at 50 ° C, and stir at 60 ° C. While measuring the isocyanate group content by NCO titration according to K1603-1, the reaction was carried out until the isocyanate group disappeared to obtain a urethane acrylate oligomer (e-5).
40 parts by mass of urethane acrylate oligomer (e-5), 40 parts by mass of HBMA, and 20 parts by mass of DMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 6]
10 parts by mass of the urethane acrylate oligomer (e-4) obtained in Example 4, 40 parts by mass of HBMA, 50 parts by mass of the urethane acrylate oligomer (e-8) obtained in Example 13 were mixed, and 1 of HCHPK A part by mass was added to prepare a photocurable resin composition.

[Example 7]
80 parts by mass of the urethane acrylate oligomer (e-4) obtained in Example 4 and 20 parts by mass of HBMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 8]
1 part by mass of HCHPK was added to 100 parts by mass of the urethane acrylate oligomer (e-4) obtained in Example 4 to prepare a photocurable resin composition.

[Example 9]
A urethane acrylate oligomer (e-6) was obtained in the same manner as in Example 4 except that the polyol (b-7) was used instead of the polyol (b-6), and a photocurable resin was obtained in the same manner as in Example 6. A composition was prepared.

[Example 10]
80 parts by mass of the urethane acrylate oligomer (e-6) obtained in Example 9 and 20 parts by mass of HBMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 11]
7.0 parts by mass (0.065 mol) of hexamethylene diisocyanate (hereinafter referred to as HDI) is added to 100 parts by mass (0.05 mol) of polyol (b-6), and 0.01 parts by mass of DBTDL. Was reacted at 80 ° C. for 4 hours to obtain a urethane prepolymer. 0.05 parts by mass of DBTDL and 0.05 parts by mass of HQME are added to the urethane prepolymer, 5.0 parts by mass (0.03 mol) of HEA is added at 50 ° C., and the mixture is stirred at 60 ° C. While measuring the isocyanate group content by NCO titration according to K1603-1, the reaction was carried out until the isocyanate group disappeared to obtain a urethane acrylate oligomer (e-7).
10 parts by mass of urethane acrylate oligomer (e-7), 40 parts by mass of HBMA, 50 parts by mass of urethane acrylate oligomer (e-8) obtained in Example 13 were mixed, 1 part by mass of HCHPK was added, and light A curable resin composition was prepared.

[Example 12]
10 parts by mass of urethane acrylate oligomer (e-4) obtained in Example 4, 40 parts by mass of 2-hydroxypropyl methacrylate (hereinafter referred to as HPMA), urethane acrylate oligomer (e-8) obtained in Example 13 ) And 1 part by mass of HCHPK were added to prepare a photocurable resin composition.

[Example 13]
A urethane acrylate oligomer (e-8) was obtained in the same manner as in Example 1 except that the polyol (b-8) was used instead of the polyol (b-3).
40 parts by mass of urethane acrylate oligomer (e-8), 40 parts by mass of HPMA, and 20 parts by mass of DMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 14]
5 parts by mass of the urethane acrylate oligomer (e-4) obtained in Example 4, 40 parts by mass of HPMA, and 55 parts by mass of the urethane acrylate oligomer (e-8) obtained in Example 13 were mixed, and 1 of HCHPK A part by mass was added to prepare a photocurable resin composition.

[Example 15]
A urethane acrylate oligomer (e-9) was obtained in the same manner as in Example 1 except that the polyol (b-1) was used instead of the polyol (b-3).
40 parts by mass of urethane acrylate oligomer (e-9), 40 parts by mass of HBMA, and 20 parts by mass of DMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Example 16]
A urethane acrylate oligomer (e-10) was obtained in the same manner as in Example 1 except that the polyol (b-2) was used instead of the polyol (b-3).
40 parts by mass of urethane acrylate oligomer (e-10), 40 parts by mass of HBMA, and 20 parts by mass of DMA were mixed, and 1 part by mass of HCHPK was added to prepare a photocurable resin composition.

[Physical properties of unsaturated urethane oligomer (A)]
The phosphorus content was measured for each urethane acrylate oligomer. The results are shown in Table 2.

[Physical properties of curable resin composition]
About each curable resin composition obtained in Examples 1-16, phosphorus content was measured. Moreover, the viscosity was measured about each curable resin composition obtained in Examples 1-14. The results are shown in Table 3 and Table 4.

[Manufacture of laminates]
Using each curable resin composition obtained in Examples 1-14, a transparent laminate (laminated glass) was produced as follows.
Each curable resin composition was stored in a vacuum chamber in an open state while being put in a container, and was used after defoaming by reducing the pressure in the vacuum chamber to about 200 Pa · s and holding for 10 minutes. .

  As a transparent substrate, two soda lime glasses having a length of 610 mm, a width of 610 mm, and a thickness of 2 mm were prepared. After sticking a double-sided adhesive tape (seal material) having a thickness of 1 mm and a width of 10 mm along the edges of the four sides of one transparent substrate, the release film on the upper surface of the double-sided adhesive tape was removed.

  An ultraviolet curable resin for sealing prepared by uniformly mixing 100 parts by mass of urethane acrylate oligomer (manufactured by Kyoeisha Chemical Co., Ltd., product name “UF8001G”) and 1 part by mass of benzoin isopropyl ether (polymerization initiator) in advance On the upper surface of the adhesive tape, a coating thickness of about 0.3 mm was applied with a dispenser to form an ultraviolet curable resin layer for sealing. The curable resin composition was dropped at a plurality of locations using a dispenser in a region surrounded by the double-sided adhesive tape on the surface of the transparent substrate on which the double-sided adhesive tape was applied, so that the total mass was 380 g.

As shown in FIG. 1, the transparent substrate 10 in which the curable resin composition 14 was dropped in a region surrounded by the double-sided adhesive tape 12 (sealing material) was placed horizontally in the decompression chamber 26.
The other transparent substrate 16 is held on the upper surface plate 30 in the decompression chamber 26 by using the suction pad 32, is opposed to the transparent substrate 10 in parallel, and the distance from the transparent substrate 10 is 10 mm. .

The decompression chamber 26 was sealed, and the vacuum pump 28 was operated to evacuate the interior of the decompression chamber 26 to about 30 Pa. At this time, foaming of the curable resin composition 14 did not continue.
The upper platen 30 was lowered by the cylinder 34, and the transparent substrate 10 and the transparent substrate 16 were pressure-bonded with a pressure of 2 kPa and held for 1 minute.
The inside of the decompression chamber 26 was returned to atmospheric pressure in about 30 seconds, and a laminated precursor in which the transparent substrate 10 and the transparent substrate 16 were in close contact with each other through the uncured layer of the curable resin composition 14 was obtained.

The upper surface plate 30 was raised by the cylinder 34, and the laminated precursor adhered to the suction pad 32 of the upper surface plate 30 was peeled from the upper surface plate 30.
For sealing the upper surface of the double-sided adhesive tape 12 by irradiating UV light from a fiber light source using a high-pressure mercury lamp as a light source through the transparent substrate 16 to the portion where the double-sided adhesive tape 12 exists on the outer periphery of the laminated precursor. The ultraviolet curable resin 36 was cured. Thereafter, the laminated precursor was kept horizontal and allowed to stand for about 1 hour.

In the curable resin compositions of Examples 1 and 2 in which V ₂₅ is 0.10 Pa · s or less, liquid leakage occurs from the sealing material when the inside of the vacuum chamber is returned to atmospheric pressure. Application of was difficult. Therefore, for Examples 1 and 2, pasted together through a double-sided adhesive tape with a pair of transparent substrates pasted in advance, partially peeled off the upper side sealing material to provide an opening, using the syringe from the gap A predetermined amount of the curable resin composition was injected between the transparent substrates. Next, after standing in a vertical position for a long time and collecting the mixed bubbles on the upper side of the sealing material, the injection port was again brought into close contact with the double-sided adhesive tape so as to push out the collected bubbles, and sealed. Thereafter, the laminated precursor was kept horizontal and allowed to stand for about 24 hours.

A transparent laminate (laminated glass) is obtained by curing the curable resin composition 14 by irradiating ultraviolet rays having an intensity of 1 mW / cm ² for 10 minutes uniformly from both sides of the laminate precursor with a high-pressure mercury lamp. Obtained. The evaluation results of the transparent laminate are shown in Table 3 and Table 4.

The transparent laminates of Examples 1 to 12 using a curable resin composition having a phosphorus content of 0.1% by mass or more had good flame retardancy and good transparency.
On the other hand, since the transparent laminated bodies of Examples 13 and 14 used a curable resin composition having a phosphorus content of less than 0.1% by mass, the flame retardancy was insufficient. In the curable resin compositions of Examples 15 and 16, since the hydroxyl value of the polyol (a1) was high, the urethane acrylate oligomer and the monomer were not compatible. Therefore, in Examples 15 and 16, the transparent laminate was not manufactured.
A transparent laminate was obtained in the same manner by replacing DMA used in Examples with n-octadecyl methacrylate. Results similar to those shown in Table 2 were obtained.

The curable resin composition of the present invention is useful as a raw material for the adhesive resin layer of laminated glass, and the transparent laminate of the present invention is laminated glass (windshield glass, safety glass, security glass, fire safety glass, etc.), It is useful for displays, solar cell modules and the like.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2009-178257, filed on July 30, 2009, are cited herein as disclosure of the specification of the present invention. Incorporated.

DESCRIPTION OF SYMBOLS 10 Transparent substrate 12 Double-sided adhesive tape 14 Curable resin composition 16 Transparent substrate 26 Depressurization chamber 28 Vacuum pump 30 Top plate 32 Adsorption pad 34 Cylinder 36 UV curable resin for sealing

Claims (13)

It is a reaction product of the following polyol component (A1), polyisocyanate compound (A2), and unsaturated hydroxy compound (A3) below, and has an average of 2 to 4 curable functional groups per molecule, Unsaturated urethane oligomer (A) whose phosphorus content is 1-7 mass%.
Polyol component (A1): A polyol component containing the following polyol (a1) and the following polyol (a2) .
Polyol (a1): A polyol having 2 to 3 hydroxyl groups per molecule, a hydroxyl value of 35 to 150 mgKOH / g, and having a phosphorus atom in the molecule.
Polyol (a2): A polyoxyalkylene polyol having 2 hydroxyl groups per molecule and a hydroxyl value of 20 to 120 mgKOH / g and having no phosphorus atom in the molecule.
Unsaturated hydroxy compound (A3): A compound having the following curable functional group and hydroxyl group.
Curable functional _{group: CH 2 = C (R)} C (O) O- ( wherein, R is a hydrogen atom or a methyl group). The unsaturated urethane oligomer (A ) of Claim 1 whose ratio of the said polyol (a2) is 0.2-4 mol with respect to 1 mol of a polyol (a1 ).   A curable resin composition comprising the unsaturated urethane oligomer (A) according to claim 1 or 2.   The curable resin composition according to claim 3, which is a curable resin composition used in a method for producing a transparent laminate by curing a curable resin composition sandwiched between a pair of transparent substrates. The curable resin composition of Claim 4 which further contains the following monomer (B).
Monomer (B): a compound represented by CH ₂ ═C (R) C (O) O—R ² (wherein R is a hydrogen atom or a methyl group, and R ² has 1 to 1 hydroxyl groups) 2 and a hydroxyalkyl group having 3 to 4 carbon atoms). The curable resin composition according to claim 4 or 5, further comprising the following monomer (C).
Monomer (C): a compound represented by CH ₂ ═C (R) C (O) O—R ³ (wherein R is a hydrogen atom or a methyl group, and R ³ has 8 to 8 carbon atoms) 22 alkyl groups).   The curable resin composition according to any one of claims 4 to 6, further comprising a photopolymerization initiator (D).   Curable resin composition as described in any one of Claims 4-7 whose phosphorus content in curable resin composition (100 mass%) is 0.1-5 mass%. A transparent laminate having a pair of transparent substrates and a layer of cured resin sandwiched between the transparent substrates,
The transparent laminated body whose said cured resin is a hardened | cured material of the curable resin composition as described in any one of Claims 4-8.   The transparent laminate according to claim 9, wherein at least one of the pair of transparent substrates is a glass plate. In a reduced-pressure atmosphere, a sealed space containing the curable resin composition according to any one of claims 4 to 8 is formed between a pair of transparent substrates, and the pair of transparent substrates and the pair of transparent substrates are formed. A first step of producing a laminated precursor having the curable resin composition sealed between transparent substrates;
A method for producing a transparent laminate, comprising: placing the laminate precursor in an atmosphere having a higher pressure than the reduced-pressure atmosphere, and curing the curable resin composition in the atmosphere.   The manufacturing method according to claim 11, wherein the reduced-pressure atmosphere is a pressure atmosphere of 100 Pa or less, and the atmosphere having a higher pressure than the reduced-pressure atmosphere is an atmospheric pressure atmosphere.   The production according to claim 11 or 12, wherein the curable resin composition is a photocurable resin composition, and in the second step, the laminated precursor is irradiated with light to cure the curable resin composition. Method.

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