JP2017066278A - Moisture curable urethane composition and coating material - Google Patents

Abstract

[PROBLEMS] The problem to be solved by the present invention is that there is no dripping at the time of construction, and the temperature at the time of the test specified in the tensile performance of urethane rubber system in “Table 1 Performance of waterproofing coating film for roof” of JIS A6021: 2011. An object of the present invention is to provide a material that can easily apply a coating material that satisfies the high-strength standards of 23 ° C. and 60 ° C. and is excellent in transparency.
The present invention relates to an amorphous polyol (a-1-1) and a polyol (a-1) containing a chain extender (a-1-2) and a polyisocyanate (a-2). Urethane prepolymer (A) having an isocyanate group as a reaction product, oxazolidine group as a reaction product of polyol (b-1), polyisocyanate (b-2) and N-2-hydroxyalkyloxazolidine (b-3) The present invention provides a moisture-curing urethane composition comprising a urethane compound (B) having an acid catalyst, an acid catalyst (C), and a thixotropic agent (D).
[Selection figure] None

Description

  The present invention relates to a useful moisture-curable urethane composition having excellent high strength.

  In recent years, there is a growing need for higher strength and higher toughness for waterproofing materials and reinforcing resin for the purpose of improving durability of urethane materials. In particular, as a waterproof material, a standard of “high-strength type” has been established in JIS A6021, and the industry is actively developing materials that satisfy this standard.

  As a material satisfying the high-strength standard, for example, a two-component fast-curing polyurethane is disclosed (for example, see Patent Document 1). The fast-cure polyurethane is instantly cured by spray coating, so it is easy to construct a large area. However, there is a problem that handling is poor due to the need for large-scale machine operation and the fact that the reaction is too fast. .

  In recent years, there has been a growing need for visual confirmation of the cracking status of concrete, etc., which is the base material. There is a growing need, and the diversification of needs for materials that meet high strength standards.

JP 2007-113249 A

  The problem to be solved by the present invention is that there is no dripping at the time of construction, and a test temperature of 23 ° C. stipulated in the tensile performance of urethane rubber system in “Table 1-Performance of waterproof coating material for roof” in JIS A6021: 2011, And a material that can easily apply a coating material that satisfies the standard of a high-strength type at 60 ° C. (hereinafter abbreviated as “high-strength type standard”) and is excellent in transparency.

  The present invention is a reaction product of a non-crystalline polyol (a-1-1) and a polyol (a-1) containing a chain extender (a-1-2) and a polyisocyanate (a-2). Urethane prepolymer (A) having an isocyanate group, urethane compound having an oxazolidine group which is a reaction product of polyol (b-1), polyisocyanate (b-2) and N-2-hydroxyalkyloxazolidine (b-3) A moisture-curable urethane composition characterized by containing (B), an acid catalyst (C), and a thixotropic agent (D), and a coating material characterized by being a moisture-cured product thereof It is to provide.

  The moisture-curable urethane composition of the present invention does not sag at the time of construction, can easily produce a coating film by glazing or the like, and can be constructed without using a large machine. In addition, a cured product obtained by moisture-curing the moisture-curable urethane composition of the present invention satisfies the standard of the high-strength type standard, and therefore has extremely high strength. Moreover, since the obtained coating | covering material is excellent in transparency, the crack condition etc. of concrete etc. which are base | substrates can be confirmed visually. Therefore, the moisture-curable urethane composition of the present invention can be suitably used as a covering material for civil engineering construction, and can be particularly suitably used as a waterproof material and a concrete repair material.

  The moisture curable urethane composition of the present invention comprises an amorphous polyol (a-1-1), a polyol (a-1) containing a chain extender (a-1-2), and a polyisocyanate (a-2). And a reaction product of urethane prepolymer (A) having an isocyanate group, which is a reaction product with polyol), polyol (b-1), polyisocyanate (b-2) and N-2-hydroxyalkyloxazolidine (b-3). It contains a urethane compound (B) having a certain oxazolidine group, an acid catalyst (C), and a thixotropic agent (D) as essential components.

  The amorphous polyol (a-1-1) is an essential component for obtaining particularly excellent transparency. In the present invention, the term “non-crystalline” means that the peak of heat of crystallization or heat of fusion cannot be confirmed in DSC (Differential Scanning Calorimetry) measurement based on JISK7121: 2012.

  As the non-crystalline polyol (a-1-1), specifically, for example, non-crystalline polyester polyol which is a reaction product of low molecular weight glycol and aromatic polybasic acid; low molecular weight glycol having a side chain A non-crystalline polyester polyol which is a reaction product of a polybasic acid and an aliphatic polybasic acid; a non-crystalline polyether polyol obtained by ring-opening addition of a cyclic ether monomer having a side chain with a low molecular weight glycol as an initiator; Non-crystalline polycarbonate polyol, which is a reaction product of a low molecular weight glycol and a carbonate, can be used. The “low molecular weight” means a number average molecular weight in the range of 50 to 400. In addition, the said number average molecular weight shows the value obtained by measuring similarly to the number average molecular weight of the said non-crystalline polyol (a-1-1).

  Examples of the low molecular weight glycol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8. -Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, bisphenol A, bisphenol F, hydrogenated bisphenol A, Hydrogenated bisphenol F or the like can be used. These compounds may be used alone or in combination of two or more.

  Examples of the aromatic polybasic acid include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, and the like. These compounds may be used alone or in combination of two or more.

  Examples of the low molecular weight glycol having a side chain include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, and 2-methyl-1,5-pentane. Diol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol and the like can be used. . These compounds may be used alone or in combination of two or more.

  Examples of the aliphatic polybasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid and the like. These compounds may be used alone or in combination of two or more.

  Examples of the cyclic ether monomer having a side chain include propylene oxide and butylene oxide. These compounds may be used alone or in combination of two or more.

  Examples of the carbonate ester having a side chain include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like. These compounds may be used alone or in combination of two or more.

  As the non-crystalline polyol (a-1-1), non-crystalline polymer obtained by ring-opening addition of a cyclic ether monomer having a side chain with a low molecular weight glycol as an initiator from the viewpoint of obtaining excellent transparency. It is preferable to use an ether polyol and / or a non-crystalline polycarbonate polyol which is a reaction product of two or more kinds of low molecular weight glycols and carbonates. From the viewpoint of obtaining excellent high strength, polyoxypropylene glycol, It is more preferable to use a polycarbonate polyol using 1,5-pentanediol and 1,6-hexanediol as raw materials.

  The number average molecular weight of the non-crystalline polyol (a-1-1) is preferably in the range of 500 to 5,000, preferably in the range of 700 to 4,000, from the viewpoint of obtaining excellent transparency. More preferably. In addition, the number average molecular weight of the said non-crystalline polyol (a-1-1) shows the value obtained by measuring on condition of the following by gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000" (7.8 mm ID x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 “TSKgel G2000” (7.8 mm ID × 30 cm) × 1 detector: RI (differential refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

  The chain extender (a-1-2) is an essential component for satisfying the high strength form standard. The use of the chain extender (a-1-2) increases the urethane group concentration, and a polyurethane having a high mechanical strength can be obtained by forming a sea-island structure in the resulting polyurethane. Widely known in the field. However, excellent transparency can be obtained by combining with the amorphous polyol (a-1-1) to obtain a urethane prepolymer (A) and further combining with the urethane compound (B) having an oxazolidine group described later. It was found that the high strength type standard was satisfied.

  Examples of the chain extender (a-1-2) include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, and tripropylene glycol. , Butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9- Nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3 -Propanediol, 3-methyl-1,5-pentanediol Aliphatic polyols such as 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, glycerin, trimethylolpropane, ditrimethylolpropane, trimethylolpropane, pentaerythritol; 1,4-cyclohexanedi Aliphatic polyols such as methanol and hydrogenated bisphenol A; aromatic polyols such as bisphenol A, alkylene oxide adducts of bisphenol A, bisphenol S, alkylene oxide adducts of bisphenol S, and the like can be used. These chain extenders may be used alone or in combination of two or more. Among these, it is preferable to use one or more chain extenders selected from the group consisting of dipropylene glycol, propylene glycol and butanediol from the viewpoint of further improving the high strength and storage stability.

  The number average molecular weight of the chain extender (a-1-2) is preferably in the range of 50 to 450 from the viewpoint of tensile strength. In addition, the number average molecular weight of the said chain extender (a-1-2) shows the value obtained by measuring similarly to the number average molecular weight of the said non-crystalline polyol (a-1-1).

  As the usage-amount of the said chain extender (a-1-2), 1-40 mass with respect to the total amount of the said polyol (a-1) and polyisocyanate (a-2) from the point of tensile strength. % Is preferable, and the range of 3 to 30% by mass is more preferable.

  The polyol (a-1) contains the non-crystalline polyol (a-1-1) and the chain extender (a-1-2) as essential components. It does not contain ingredients.

  Examples of the crystalline component include crystalline polyether polyol, crystalline polyester polyol, crystalline polycarbonate polyol, and the like.

  Examples of the polyisocyanate (a-2) include aromatic diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, carbodiimidized diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, naphthalene diisocyanate, phenylene diisocyanate, xylylene diisocyanate; hexamethylene diisocyanate. In addition, aliphatic or alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and cyclohexane diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, it is more preferable to use one or more polyisocyanates selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate from the viewpoint that the high strength and storage stability can be further improved.

  As a method for producing the urethane prepolymer (A), the molar ratio (NCO / OH) of the hydroxyl group of the polyol (a-1) to the isocyanate group of the polyisocyanate (a-2) is preferably 1. Using the method of reacting the polyol (a-1) and the polyisocyanate (a-2) in the range of .2 to 1.9 provides excellent high strength at a test temperature of 60 ° C. It is preferable from the point.

  The urethane prepolymer (A) has an isocyanate group, and as its isocyanate group content (hereinafter abbreviated as “NCO%”), excellent high strength at a test temperature of 60 ° C. and good From the viewpoint of obtaining storage stability, it is preferably 4% by mass or more, more preferably in the range of 4-10% by mass, and still more preferably in the range of 4.5-8% by mass.

  The weight average molecular weight of the urethane prepolymer (A) is preferably in the range of 1,000 to 20,000 from the viewpoint of further improving the curing rate, adhesiveness, high strength and storage stability. The range of 4,000 to 8,000 is more preferable. In addition, the weight average molecular weight of the said urethane prepolymer (A) shows the value obtained by measuring similarly to the number average molecular weight of the said non-crystalline polyol (a-1-1).

  Examples of the polyol (b-1) used as a raw material for the urethane compound (B) having the oxazolidine group include polyether polyol, polyester polyol, polycarbonate polyol, polyacryl polyol, dimer diol, and polybutadiene polyol. it can. These polyols may be used alone or in combination of two or more. Among these, it is preferable to use a polyether polyol from the viewpoint that workability and flexibility can be further improved.

  Examples of the first polyether polyol include polyoxyethylene polyol, polyoxypropylene polyol, polyoxytetramethylene polyol, polyoxyethylene polyoxypropylene polyol, polyoxyethylene polyoxytetramethylene polyol, and polyoxypropylene polyoxytetramethylene polyol. Etc. can be used. These polyether polyols may be used alone or in combination of two or more.

  The number average molecular weight of the polyol (b-1) is preferably in the range of 500 to 5,000, more preferably in the range of 800 to 3,000, from the viewpoint that workability and flexibility can be further improved. In addition, the number average molecular weight of the said polyol (b-1) shows the value obtained by measuring similarly to the number average molecular weight of the said polytetramethylene glycol (a-1-1).

  As said polyisocyanate (b-2) used as a raw material of the urethane compound (B) which has the said oxazolidine group, the thing similar to the said polyisocyanate (a-2) can be used.

  As said N-2-hydroxyalkyl oxazolidine (b-3), what was obtained by reacting an aldehyde compound and a dihydroxyalkylamine compound can be used, for example.

  As the aldehyde compound, for example, formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, benzaldehyde and the like can be used. These compounds may be used alone or in combination of two or more.

  Examples of the dihydroxyalkylamine compound that can be used include diethanolamine and dipropanolamine. These compounds may be used alone or in combination of two or more.

  The urethane compound (B) is obtained by reacting the polyol (b-1), the polyisocyanate (b-2), and the N-2-hydroxyalkyloxazolidine (b-3) by a known method, The number of oxazolidine groups is preferably in the range of 1 to 4, more preferably in the range of 1 to 3, from the viewpoints of tensile performance and workability at low temperatures and high temperatures.

  The number average molecular weight of the urethane compound (B) is preferably in the range of 500 to 15,000 from the viewpoint of further improving the adhesion to the substrate and the curing rate. In addition, the number average molecular weight of the said urethane compound (B) shows the value measured similarly to the said polytetramethylene glycol (a-1-1).

  The urethane compound (B) is used in an amount that can further improve the tensile performance at low temperatures and high temperatures, the curing rate, the adhesion to the substrate, the high strength, and the storage stability. The range of 10 to 100 parts by mass is preferable with respect to 100 parts by mass of the polymer (A), and the range of 20 to 60 parts by mass is more preferable.

  The acid catalyst (C) promotes dissociation of the oxazolidine group of the urethane compound (B). For example, sulfuric acid, hydrochloric acid, phosphoric acid, carbonic acid, alkylbenzenesulfonic acid, benzoic acid, salicylic acid, formic acid, acetic acid, Organic acids or inorganic acids such as maleic acid and fumaric acid; salts thereof and the like can be used. These acid catalysts may be used alone or in combination of two or more. Among these, it is preferable to use one or more acid catalysts selected from the group consisting of phosphoric acid, salicylic acid and phosphate from the viewpoint of further improving the curability.

  As the usage-amount of the said acid catalyst (C), it is preferable that it is the range of 0.01-1 mass part with respect to 100 mass parts of said urethane compounds (B) from a sclerosing | hardenable point.

  The thixotropic agent (D) is an essential component for imparting thixotropy to the moisture-curable urethane composition and preventing sagging during construction.

  Examples of the thixotropic agent (D) include organic compounds such as amide wax, hydrogenated castor oil, 1,3,5-tris (trialkoxysilylalkyl) isocyanurate; inorganic compounds such as fumed silica and carbon black Etc. can be used. These thixotropic agents may be used alone or in combination of two or more. Among these, it is preferable to use fumed silica since the compatibility with the urethane prepolymer (A) and the urethane compound (B) is good and excellent transparency is obtained.

  The fumed silica may be either unmodified fumed silica (fumed silica) or a particle surface of fumed silica that has been hydrophobically modified with various surface treatment agents.

 The fumed silica is obtained by a dry method, and specifically is silicon dioxide obtained by vaporizing silicon tetrachloride and hydrolyzing it in a high-temperature flame. However, in the manufacturing process, an aggregate of these is formed.

  Siloxane groups and silanol groups are present on the surface of the agglomerated silicon dioxide and show hydrophilicity. On the other hand, hydrophobicity is imparted by reacting this silanol group with a surface treatment agent.

  Examples of the surface treating agent include dimethyldichlorosilane, dimethyl silicone oil, hexamethyldisilazane, octylsilane, hexadecylsilane, aminosilane, methacrylsilane, octamethylcyclotetrasiloxane, polydimethylsiloxane, and the like.

As the specific surface area by the BET method of the fumed silica is preferably in the range of 30~300m ² / g, and more preferably in the range of 60~200m ² / g.

  Examples of the hydrophilic type of the fumed silica include “Aerosil 50”, “Aerosil 90G”, “Aerosil 130”, “Aerosil 200”, “Aerosil 200CF”, “Aerosil 200V”, “Aerosil 300”, “Aerosil 300CF”. "(Nippon Aerosil Co., Ltd.) etc. can be obtained as a commercial item.

  As the hydrophobic type, “Aerosil DT4”, “Aerosil NA200Y”, “Aerosil NA50H”, “Aerosil NAX50”, “Aerosil NAX50”, “Aerosil R104”, “Aerosil R106”, “Aerosil R202”, “Aerosil” R202W90, “Aerosil R504”, “Aerosil R711”, “Aerosil R700”, “Aerosil R805”, “Aerosil R805”, “Aerosil R805VV90”, “Aerosil R812”, “Aerosil 812S”, “Aerosil R816”, “Aerosil” R8200, Aerosil R972, Aerosil R972V, Aerosil R974, Aerosil RA200HS, Aerosil RX200, Aerosil RX300, Aerosil RX50 ", you are possible to obtain" Aerosil RY200 "," Aerosil RY200S "," Aerosil RY300 "," Aerosil RY50 "(or more, Nippon Aerosil Co., Ltd.) as a commercially available product and the like. In addition to Nippon Aerosil Co., Ltd., similar fumed silica can be obtained from Tokuyama Corporation.

  As the use amount of the thixotropic agent (D), dripping at the time of construction can be satisfactorily suppressed, and the viscosity of the moisture-curing urethane composition is in an appropriate range, and good workability can be obtained. The range is preferably 0.01 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the urethane prepolymer (A) and the urethane compound (B).

  The moisture-curable urethane composition of the present invention contains the urethane prepolymer (A), the urethane compound (B), the acid catalyst (C), and the thixotropic agent (D) as essential components. However, if necessary, other additives may be contained.

  Examples of the other additives include plasticizers, fillers, organic solvents, pigments, thixotropic agents, process oils, UV inhibitors, reinforcing materials, aggregates, curing accelerators, flame retardants, and the like. it can. These additives may be used alone or in combination of two or more. Among these, it is preferable to add a plasticizer from the viewpoint of improving the elongation at break and the elongation between grips at break.

  Examples of the plasticizer include 2-ethylhexyl phthalate, dibutyl phthalate, dioctyl phthalate, diundecyl phthalate, dilauryl phthalate, butyl benzyl phthalate, diisodecyl phthalate, dibutyl adipate, dioctyl adipate, diisononyl adipate, diisononyl adipate, dioctyl azelate, Dioctyl sebacate, trioctyl phosphate, triphenyl phosphate and the like can be used. These plasticizers may be used alone or in combination of two or more. When the plasticizer is used, the amount used is in the range of 0.5 to 30% by mass with respect to 100 parts by mass in total of the urethane prepolymer (A) and the urethane compound (B) having the oxazolidine group. Preferably, the range of 1-20 mass% is more preferable.

  The moisture-curable urethane composition of the present invention does not sag at the time of construction, can easily produce a coating film by glazing or the like, and can be constructed without using a large machine. In addition, a cured product obtained by moisture-curing the moisture-curable urethane composition of the present invention satisfies the standard of the high-strength type standard, and therefore has extremely high strength. Moreover, since the obtained coating | covering material is excellent in transparency, the crack condition etc. of concrete etc. which are base | substrates can be confirmed visually. Therefore, the moisture-curable urethane composition of the present invention can be suitably used as a covering material for civil engineering construction, and can be particularly suitably used as a waterproof material and a concrete repair material.

  As a base (base) to be applied when the moisture-curable urethane composition of the present invention is used as a civil engineering-related coating material, an inorganic base material such as concrete, asphalt, or mortar; metal, wood, fabric, plastic, or the like is used. be able to. Moreover, although the thickness at the time of apply | coating is suitably determined according to a use, it is the range of 0.1-10 mm, for example.

  The moisture curable urethane composition is cured by moisture to obtain a cured product. Examples of the moisture curing method include a method of curing for 5 to 10 days under conditions of 25 ° C. and a humidity of 50%.

The cured product obtained by the above method satisfies the high-strength form standard, that is, the tensile strength (temperature at the time of test 23 ° C.) measured in accordance with JIS A6021: 2011 of the cured product is 10 N / mm ² or more. , Tensile strength (test temperature 60 ° C.) is 6 N / mm ² or more, elongation at break (test temperature 23 ° C.) is 200% or more, elongation between grips at break (test time) The temperature 23 ° C.) is 120% or more, and the elongation between the grips at the time of break (test temperature 60 ° C.) is 100% or more.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Synthesis Example 1] Synthesis of Urethane Prepolymer (A-1) 300 parts by mass of polyoxypropylene glycol having a number average molecular weight of 1,000 (hereinafter abbreviated as “PPG1000”) and polyoxypropylene having a number average molecular weight of 3,000 180 parts by mass of glycol (hereinafter abbreviated as “PPG3000”) and 170 parts by mass of dipropylene glycol (hereinafter abbreviated as “DPG”) were mixed, and toluene diisocyanate (hereinafter abbreviated as “TDI”) 350. Mass parts were added and reacted at 90 ° C. for 8 hours under a nitrogen stream to obtain NCO%; 4.6% by mass of urethane prepolymer (A-1).

[Synthesis Example 2] Synthesis of urethane prepolymer (A-2) 300 parts by mass of PPG1000, 360 parts by mass of PPG3000, and 70 parts by mass of DPG were mixed, and 270 parts by mass of TDI was added thereto. It was made to react at 0 degreeC for 8 hours, and obtained NCO%; 6.3 mass% urethane prepolymer (A-2).

Synthesis Example 3 Synthesis of Urethane Prepolymer (A-3) Polycarbonate polyol (using 1,5-pentanediol and 1,6-hexanediol as raw materials, number average molecular weight 1,000 (hereinafter “1,5 PG / 1. Abbreviated as “1,6HG-PC1000”.) 300 parts by mass, 180 parts by mass of PPG 3000 and 170 parts by mass of DPG were mixed, 350 parts by mass of TDI was added thereto, and the mixture was reacted at 90 ° C. for 8 hours in a nitrogen stream. , NCO%; 4.6% by mass of urethane prepolymer (A-3) was obtained.

[Synthesis Example 4] Synthesis of Urethane Prepolymer (A-4) Polycarbonate polyol (using 1,5-pentanediol and 1,6-hexanediol as raw materials, number average molecular weight 3,000 (hereinafter referred to as “1,5PG / "1,6HG-PC3000")) 300 parts by mass, PPG3000 380 parts by mass, DPG 60 parts by mass are mixed, and TDI is added 260 parts by mass, and the mixture is reacted at 90 ° C. for 8 hours in a nitrogen stream. , NCO%; 6.9% by mass of urethane prepolymer (A-4) was obtained.

[Synthesis Example 5] Synthesis of urethane prepolymer (A-5) 570 parts by mass of PPG3000 and 140 parts by mass of DPG were mixed, 290 parts by mass of TDI was added thereto, and the mixture was reacted at 90 ° C for 8 hours under a nitrogen stream. NCO%; 5.7 mass% urethane prepolymer (A-5) was obtained.

[Comparative Synthesis Example 1] Synthesis of Urethane Prepolymer (A′-1) Polyoxytetramethylene glycol (number average molecular weight 1,000 (hereinafter abbreviated as “PTMG1000”)) is 300 parts by mass, PPG3000 is 440 parts by mass, 40 parts by mass of DPG was mixed, 220 parts by mass of TDI was added thereto, and the mixture was reacted at 90 ° C. for 8 hours under a nitrogen stream to obtain NCO%; 5.9% by mass of urethane prepolymer (A′-1). .

[Comparative Synthesis Example 2] Synthesis of urethane prepolymer (A'-2) 300 parts by mass of PTMG1000, 180 parts by mass of PPG3000, 170 parts by mass of DPG, 350 parts by mass of TDI were added thereto, and under a nitrogen stream, It was made to react at 90 degreeC for 8 hours, and NCO%; 4.6 mass% urethane prepolymer (A'-2) was obtained.

Comparative Synthesis Example 3 Synthesis of Urethane Prepolymer (A′-3) Polycarbonate polyol (using 1,6-hexanediol as a raw material, number average molecular weight 3,000 (hereinafter abbreviated as “1,6HG-PC1000”) .) 300 parts by mass, 180 parts by mass of PPG 3000, and 170 parts by mass of DPG were mixed, 350 parts by mass of TDI was added thereto, and the mixture was reacted at 90 ° C. for 8 hours under a nitrogen stream. NCO%: 4.6% by mass Of urethane prepolymer (A′-3) was obtained.

[Comparative Synthesis Example 4] Synthesis of Urethane Prepolymer (A′-4) 1,000 parts by mass of PPG1000 was added, 392 parts by mass of TDI was added thereto, and reacted at 90 ° C. for 8 hours under a nitrogen stream, NCO%; 7.6 mass% urethane prepolymer (A'-4) was obtained.

[Synthesis Example 6] Synthesis of urethane compound (B-1) Polyoxyethylene polyoxypropylene glycol (number average molecular weight; 1,000, content of oxyethylene structure; 20% by mass, hereinafter abbreviated as “EOPO”). ) And 80 parts by mass of TDI were reacted to obtain a urethane prepolymer of NCO%; 16.8% by mass. Next, while stirring by adding 40 parts by mass of xylene, 114.5 of N-2-isopropyl-3- (2-hydroxyethyl) -1,3-oxazolidine (hereinafter abbreviated as “OXZ-1”) was added. The mass part was slowly dropped while suppressing heat generation. After confirming that the exotherm had subsided, the mixture was stirred at 70 ° C. for 8 hours to obtain a urethane compound (B-1) having an oxazolidine group.

[Example 1]
Moisture-curing type by uniformly mixing the urethane prepolymer (A), urethane compound (B), acid catalyst (C), and thixotropic agent (D) shown in Table 1 in a sealed mixing container. A urethane composition was obtained.

[Examples 2 to 6 and Comparative Examples 1 to 5]
A moisture curable urethane composition in the same manner as in Example 1 except that the types and / or amounts of the urethane prepolymer (A) and the urethane compound (B) and the types of plasticizer were changed as shown in Tables 1 and 2. Got.

[Tensile performance test]
A tensile test was performed in accordance with JIS A6021: 2011 “6.6.1 Tensile performance test at 23 ° C.”, the tensile strength (N / mm ² ) at a test temperature of 23 ° C., the elongation at break (%), And the elongation rate between the grips at the time of breaking was measured.
In addition, a tensile test was performed in accordance with JIS A6021: 2011 “6.6.2 Tensile performance test at −20 ° C. and 60 ° C.”, tensile strength (N / mm ² ) at a test temperature of 60 ° C., and at break The elongation (%) between grips was measured.

[Transparency evaluation method]
The moisture-curing urethane compositions obtained in the examples and comparative examples were applied on newspaper with a thickness of 2 mm and left for 7 days under conditions of 25 ° C. and 50% humidity to obtain a cured product. Thereafter, it was visually observed from the top of the cured product whether or not the letters on the newspaper could be confirmed.

[Evaluation method of sagging during construction]
The moisture-curing urethane compositions obtained in Examples and Comparative Examples were applied to a concrete plate standing vertically on a desk using a brush. At this time, when the dripping of the moisture curable urethane composition was not confirmed, “◯” was evaluated, and when it was confirmed, “×” was evaluated.

Abbreviations in Tables 1 and 2 will be described.
“Aerosil 200”; “Aerosil 200” manufactured by Nippon Aerosil Co., Ltd.

  Examples 1 to 6, which are the moisture curable urethane composition of the present invention, satisfy the standards of high strength type standards, have excellent transparency, and were not found to sag during construction.

  On the other hand, although Comparative Examples 1-3 were the aspects containing the crystal component as a polyol (a-1), all were unsatisfactory in transparency.

  Although the comparative example 4 is an aspect which does not use a chain extender (a-1-2), the standard of the high intensity | strength specification was not able to be satisfy | filled.

  Although the comparative example 5 is an aspect which does not use a thixotropic agent (D), sagging was confirmed at the time of construction.

Claims (7)

Reaction product of polyol (a-1) and polyisocyanate (a-2) containing non-crystalline polyol (a-1-1) and chain extender (a-1-2) and no crystal component A urethane prepolymer (A) having an isocyanate group,
A urethane compound (B) having an oxazolidine group, which is a reaction product of a polyol (b-1), a polyisocyanate (b-2), and an N-2-hydroxyalkyloxazolidine (b-3), an acid catalyst (C), and A moisture-curable urethane composition comprising a thixotropic agent (D). The non-crystalline polyol (a-1-1) is a polycarbonate polyol using polyoxypropylene glycol and / or 1,5-pentanediol and 1,6-hexanediol as raw materials. Moisture curable urethane composition. The moisture-curable urethane composition according to claim 1, wherein the chain extender (a-1-2) is one or more selected from the group consisting of dipropylene glycol, propylene glycol, and butanediol. The moisture-curable urethane composition according to claim 1, wherein the polyisocyanate (a-2) is one or more selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate. The moisture-curable urethane composition according to claim 1, wherein the thixotropic agent (D) is fumed silica. The tensile strength (test temperature 23 ° C.) measured in accordance with JIS A6021: 2011 of the cured product is 10 N / mm ² or more, and the tensile strength (test temperature 60 ° C.) is 6 N / mm ² or more. The elongation at break (temperature at test 23 ° C) is 200% or more, the elongation between the grips at break (test temperature 23 ° C) is 120% or more, and the elongation between the grips at break ( The moisture-curable urethane composition according to claim 1, wherein the temperature during testing is 60% or more. It is a moisture hardened | cured material of the moisture hardening type urethane composition of any one of Claims 1-6, The coating | covering material characterized by the above-mentioned.