JP2019203083A - Moisture-curable urethane hot-melt resin composition and laminate - Google Patents

Abstract

An object of the present invention is to provide a moisture-curable urethane hot melt resin composition which is excellent in initial adhesive strength and weather resistance. According to the present invention, a polyol (A), a polyisocyanate (B), and a compound (C) having at least one (meth) acryloyl group and having one hydroxyl group are essential raw materials. , A urethane prepolymer having an isocyanate group and a (meth) acryloyl group (i), a photopolymerization initiator (ii), and a light stabilizer (iii). The present invention provides a composition and a laminate having a cured product layer thereof. The light stabilizer (iii) preferably contains a hindered amine compound (iii-X) and / or a nitrogen-containing heterocyclic compound (iii-Y). [Selection diagram] None

Description

  The present invention relates to a moisture curable urethane hot melt resin composition and a laminate.

  Moisture curable urethane hot melt resin composition mainly composed of urethane prepolymer is widely used for bonding metal materials, wood materials, plastics, rubber, textile products, synthetic leather, paper products, etc. It is used in various fields such as decorative panels, automobile interior materials, and clothing.

  The characteristics of the moisture curable urethane hot melt resin composition are solvent-free as with other hot melt adhesives, and in addition to obtaining initial adhesive strength by cooling and solidification, furthermore, about 24 to 72 hours after adhesion. By reacting with the moisture in the air or the adherend within the time, the final adhesive strength that cannot be expressed with other hot melt adhesives can be obtained (see, for example, Patent Document 1). However, as with other hot melt adhesives, it is not easy to further increase the initial adhesive strength only by cooling and solidifying.

  Furthermore, in order to promote utilization in various fields, the demand for weather resistance against ultraviolet exposure is also increasing, and the development of materials that satisfy all of these demands is required.

JP 2018-167003 A

  The problem to be solved by the present invention is to provide a moisture curable urethane hot melt resin composition having excellent initial adhesive strength and weather resistance.

  The present invention provides an isocyanate group comprising, as essential raw materials, a polyol (A), a polyisocyanate (B), and a compound (C) having at least one (meth) acryloyl group and having one hydroxyl group. A moisture curable polyurethane hot melt resin composition comprising a urethane prepolymer (i) having a (meth) acryloyl group, a photopolymerization initiator (ii), and a light stabilizer (iii); and The present invention provides a laminate having the cured product layer.

  The moisture curable urethane hot melt resin composition of the present invention is excellent in initial adhesive strength and weather resistance.

  The moisture curable urethane hot melt resin composition of the present invention is a compound (C) having a polyol (A), a polyisocyanate (B), one (meth) acryloyl group, and one hydroxyl group. And a urethane prepolymer having an isocyanate group (i) a photopolymerization initiator (ii) and a light stabilizer (iii).

  The urethane prepolymer (i) has as an essential raw material a polyol (A), a polyisocyanate (B), and a compound (C) having one or more (meth) acryloyl groups and one hydroxyl group. It is obtained and has an isocyanate group and a (meth) acryloyl group.

  As said polyol (A), polyester polyol, polycaprolactone polyol, polyether polyol, polycarbonate polyol, acrylic polyol, polyurethane polyol etc. can be used, for example. These polyols may be used alone or in combination of two or more.

  The number average molecular weight of the polyol (A) is preferably in the range of 300 to 150,000, more preferably in the range of 500 to 100,000, from the viewpoint of obtaining a further excellent mechanical strength of the film. . In addition, the number average molecular weight of the said polyol (A) shows the value measured by the gel permeation chromatography (GPC) method.

  As the usage-amount of the said polyol (A), it is 50-95 mass% in the total mass of the raw material which comprises a urethane prepolymer (i) from the point from which the further outstanding adhesive strength and the mechanical strength of a film | membrane are obtained. It is preferable that it is the range of 60-90 mass%.

  Examples of the polyisocyanate (B) include aliphatic polyisocyanates or cycloaliphatic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate; polymethylene polyphenyl polyisocyanate, Aromatic polyisocyanates such as diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, xylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate; these isocyanurate bodies and the like can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanate is preferably used, and diphenylmethane diisocyanate is more preferable from the viewpoint that a further excellent adhesive strength can be obtained.

  As the usage-amount of the said polyisocyanate (B), 1-50 mass in the total mass of the raw material which comprises a urethane prepolymer (i) from the point from which the further outstanding adhesive strength and the mechanical strength of a film | membrane are obtained. % Is preferable, and the range of 3 to 40% by mass is more preferable.

  The compound (C) has at least one (meth) acryloyl group and one hydroxyl group. By using this compound (C) as a raw material for the urethane prepolymer (i), a (meth) acryloyl group can be introduced at the end of the urethane prepolymer (i), and excellent initial adhesion can be achieved by irradiation with ultraviolet rays or the like. Strength can be obtained. Furthermore, since there are other isocyanate groups at the end of the urethane prepolymer (i), the final adhesive strength by moisture curing can be obtained.

  In the present invention, “(meth) acryloyl group” means one or both of acryloyl group and methacryloyl group, and “(meth) acrylate” means either one or both of acrylate and methacrylate. .

  As the ratio of the isocyanate group to the (meth) acryloyl group at the end of the urethane prepolymer (i) ((meth) acryloyl group / isocyanate group), there is a further balance between the initial adhesive strength and the final adhesive strength. From the point obtained, the range is preferably 0.1 to 0.6, and more preferably 0.2 to 0.4.

  Examples of the compound (C) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl. (Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyethylacrylamide and the like can be used. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use 2-hydroxyethyl (meth) acrylate from the viewpoint that a (meth) acryloyl group can be easily introduced and excellent initial adhesive strength can be obtained.

  As the usage-amount of the said compound (C), in the range which is 0.01-10 mass% in the total mass of the raw material which comprises urethane (meth) acrylate (i) from the point from which much more excellent initial adhesive strength is obtained. It is preferable that the range is 0.1 to 5% by mass.

  As a method for producing the urethane prepolymer (i), for example, the polyol (A) and the polyisocyanate (B) are reacted to obtain a urethane prepolymer having an isocyanate group, and then the compound (C) is reacted. Can be manufactured.

  As an equivalent ratio (isocyanate group / hydroxyl group) between the isocyanate group possessed by the polyisocyanate (B) and the hydroxyl group possessed by the polyol (A) and the compound (C) when the urethane prepolymer (i) is produced. From the point that even better initial adhesive strength and final adhesive strength can be obtained, the range is preferably 1.1 to 10, more preferably 1.2 to 3, and 1.5 to 2.5. A range is more preferred.

  Examples of the photopolymerization initiator (ii) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1- [4- (2-hydroxyethoxy) phenyl]. 2-hydroxy-2-methyl-1-propan-1-one, thioxanthone, thioxanthone derivatives, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine Oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl) -butan-1-one and the like can be used. These photopolymerization initiators may be used alone or in combination of two or more.

  As the usage-amount of the said photoinitiator (ii), the range which is 0.0001-10 mass parts with respect to 100 mass parts of said urethane prepolymer (i) from the point from which much more outstanding ultraviolet-curing property is obtained. It is preferable that the range of 0.1-5 mass parts is more preferable.

  The light stabilizer (iii) is an essential component for obtaining excellent weather resistance. In addition, the weather resistance of the present invention means discoloration resistance due to continuous irradiation of sunlight, and in the embodiment of the present invention, UVA that most closely simulates the short wavelength region of 295 to 365 nm of sunlight. The results of a weather resistance test using a QUV accelerated weather resistance tester (Q-LAB Corporation) equipped with a -340 lamp are shown.

  Examples of the light stabilizer (iii) include a hindered amine compound (iii-X), a nitrogen-containing heterocyclic compound (iii-Y), a thiol compound, a thioether compound, a benzophenone compound, and a benzoate compound. These light stabilizers (iii) may be used alone or in combination of two or more. Among these, it is preferable to use a hindered amine compound (iii-X) and / or a nitrogen-containing heterocyclic compound (iii-Y) from the viewpoint that a further excellent weather resistance is obtained, and the hindered amine compound (iii- More preferably, X) and the nitrogen-containing heterocyclic compound (iii-Y) are used in combination.

  Examples of the hindered amine compound (iii-X) include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethylpiperidine sebacate). -4-yl), tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl- 4-piperidyl) 1,2,3,4-butanetetracarboxylate, (mixed 2,2,6,6-tetramethyl-4-piperidyl / tridecyl) 1,2,3,4-butanetetracarboxylate, Mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl) 1,2,3,4-butanetetracarboxylate, 8-acetyl-3-dodecyl-7,7, , It can be used 9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione. These compounds may be used alone or in combination of two or more.

  Examples of the nitrogen-containing heterocyclic compound (iii-Y) include N, N-bis (2-ethylhexyl)-[(1,2,4-triazol-1-yl) methyl] amine, 2- [2 -Hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzo Triazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-tert-amyl-5′-isobutylphenyl) ) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-isobutyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydro) Xy-3'-isobutyl-5'-propylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'- Benzotriazole compounds such as hydroxy-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-5 ′-(1,1,3,3-tetramethyl) phenyl] benzotriazole, and {mixed 2- [4 -[2-Hydroxy-3-tridecyloxypropyl] oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine} 2- [4- [ 2-hydroxy-3-dodecyloxypropyl] oxy] oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3 - use of triazine compounds such as triazines. These nitrogen-containing heterocyclic compounds may be used alone or in combination of two or more.

  As the usage-amount of the said light stabilizer (iii), it is the range of 0.001-20 mass parts with respect to 100 mass parts of said urethane prepolymers (i) from the point from which the further outstanding weather resistance is obtained. The range of 0.01 to 10 parts by mass is more preferable, the range of 0.1 to 5 parts by mass is more preferable, and the range of 0.5 to 3 parts by mass is particularly preferable.

  In the case where the hindered amine compound (iii-X) and the nitrogen-containing heterocyclic compound (iii-Y) are used in combination, the mass ratio [(iii-X) from the point that even better weather resistance is obtained. / (Iii-Y)] is preferably in the range of 90/10 to 10/90, more preferably in the range of 20/80 to 80/20, and still more preferably in the range of 75/25 to 25/75.

  The total mass of the hindered amine compound (iii-X) and the nitrogen-containing heterocyclic compound (iii-Y) is 70 mass in the light stabilizer (iii) from the viewpoint that much more excellent weather resistance is obtained. % Or more, preferably 80% by mass or more, and more preferably 90% by mass or more.

  The moisture curable urethane hot melt resin composition of the present invention contains the urethane prepolymer (i), the photopolymerization initiator (ii), and the light stabilizer (iii) as essential components. Depending on the case, other additives may be contained.

  Examples of the other additives include a curing catalyst, a tackifier, a plasticizer, a stabilizer, a filler, a dye, a pigment, a fluorescent brightening agent, a silane coupling agent, a wax, and a thermoplastic resin. it can. These additives may be used alone or in combination of two or more.

  As the melt viscosity of the moisture curable urethane hot melt resin composition, the viscosity at 80 ° C. is preferably 300 Pa · s or less.

  Next, the laminated body of this invention is demonstrated.

  The laminate of the present invention has a base material and a cured product layer of the moisture curable urethane hot melt resin composition.

  Examples of the base material include wood base materials such as plywood, MDF (medium density fiber board), and particle board; metal base materials such as aluminum and iron; polyester, polyamide, polystyrene, polycarbonate, vinyl chloride, and ethylene-vinyl acetate. Sheet base material obtained using resin such as polymer, polyvinyl alcohol, polyethylene, polypropylene; calcium silicate plate; paper; metal foil; veneer; fiber base material such as nonwoven fabric and woven fabric; synthetic leather; paper; rubber Substrate; glass substrate and the like can be used. The thickness of the base material is determined according to the application used, and is, for example, in the range of 1 to 500 mm.

  As a method of applying the moisture curable urethane hot melt resin composition on the substrate, for example, a moisture curable urethane hot melt resin composition melted at 70 to 200 ° C. is roll coater, spray coater, T -Coating methods such as a tie coater, knife coater, comma coater; a method of applying to a substrate using a precision method such as dispenser, spray, ink jet printing, screen printing, offset printing, etc.

  As a hardened | cured material layer of the said moisture hardening type urethane hot-melt composition, although suitably determined according to the use used, it is the range of 0.001-3 cm, for example.

  The applied moisture curable urethane hot melt composition can obtain an excellent initial adhesive strength by irradiation with active energy rays. Examples of the active energy rays include ultraviolet rays, electron beams, X-rays, infrared rays, and visible rays. Among these, ultraviolet rays are preferable because initial adhesive strength can be easily obtained.

  When irradiating the ultraviolet rays, for example, a light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a hydrogen lamp, a deuterium lamp, a halogen lamp, a xenon lamp, a carbon arc lamp, or a fluorescent lamp can be used.

The irradiation amount of the ultraviolet rays is from 0.05 to 5 J / cm ² , more preferably from 0.1 to 3 J / cm ² , and particularly preferably from 0.3 to 1 in terms of obtaining even better initial adhesive strength. It may be in the range of 5 J / cm ² . In addition, the irradiation amount of the ultraviolet rays is based on a value measured in a wavelength region of 300 to 390 nm using a UV checker “UVR-N1” manufactured by GS Yuasa Corporation.

  In order to age the isocyanate group of the urethane prepolymer (i) after the ultraviolet irradiation, it is preferably cured at a temperature of 20 to 40 ° C. for 1 to 3 days.

  As described above, the moisture curable urethane hot melt resin composition of the present invention is excellent in initial adhesive strength, final adhesive strength, and weather resistance.

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

[Synthesis Example 1] Synthesis of urethane prepolymer (i-1) Polyester polyol (reaction product of 1,6-hexanediol and sebacic acid, number average molecular weight) in a 2 liter four-necked flask equipped with a stirrer and a thermometer 5,000, hereinafter abbreviated as “PEs-1”) 80 parts by mass, polyester polyol (reaction product of ethylene glycol, neopentyl glycol, adipic acid and isophthalic acid, number average molecular weight; 2,000, below Was abbreviated as “PEs-2”) and dehydrated under reduced pressure heating conditions until the water content was 0.05% by mass relative to the total amount in the flask.
Next, after cooling to 70 ° C., 12 parts by mass of 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) was added, and the temperature was raised to 100 ° C., followed by 2-hydroxyethyl acrylate (hereinafter referred to as “HEA”). 1.1 parts by mass and 2.4 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, hereinafter abbreviated as “Irg184”) are added, and the isocyanate group content is increased under a nitrogen atmosphere. The urethane prepolymer (i-1) (NCO%; 1.0%) was obtained by reacting at 110 ° C. for about 3 hours until it became constant.

[Synthesis Example 2] Synthesis of Urethane Prepolymer (i-2) A 2 liter four-necked flask equipped with a stirrer and a thermometer was charged with 50 parts by mass of PEs-1 and 50 parts by mass of PEs-2, and heated under reduced pressure. Below, it dehydrated until the water | moisture content with respect to the whole quantity in a flask became 0.05 mass%.
Next, after cooling to 70 ° C., 16.5 parts by mass of MDI was added, and after raising the temperature to 100 ° C., 1.4 parts by mass of HEA and 2.4 parts by mass of Irg184 were added, and the isocyanate group content was increased under a nitrogen atmosphere. By making it react at 110 degreeC for about 3 hours until it became constant, urethane prepolymer (i-2) (NCO%; 1.4%) was obtained.

[Synthesis Example 3] Synthesis of Urethane Prepolymer (i-3) A 2 liter four-necked flask equipped with a stirrer and a thermometer was charged with 50 parts by mass of PEs-1 and 50 parts by mass of PEs-2, and heated under reduced pressure. Below, it dehydrated until the water | moisture content with respect to the whole quantity in a flask became 0.05 mass%.
Next, after cooling to 70 ° C., 14.4 parts by mass of MDI was added, and after raising the temperature to 100 ° C., 1.1 parts by mass of HEA and 2.4 parts by mass of Irg 184 were added. The urethane prepolymer (i-3) (NCO%; 1.0%) was obtained by reacting at 110 ° C. for about 3 hours until it became constant.

[Comparative Synthesis Example 1] Synthesis of Urethane Prepolymer (iR-1) 89.5 parts by mass of PEs-1 was charged into a 2 liter four-necked flask equipped with a stirrer and a thermometer, and heated under reduced pressure. It dehydrated until the water | moisture content with respect to the whole quantity became 0.05 mass%.
Next, after cooling to 70 ° C., 10.5 parts by mass of MDI was added, the temperature was raised to 100 ° C., and the reaction was carried out at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant. Polymer (iR-1) (NCO%; 1.9%) was obtained.

[Example 1]
100 parts by mass of the urethane prepolymer (i-1) obtained in Synthesis Example 1, bis (1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate (hereinafter, “hindered amine (1)” 1 part by mass, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole (hereinafter abbreviated as “benzotriazole (1)”). ) 1 part by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Example 2]
100 parts by mass of urethane prepolymer (i-2) obtained in Synthesis Example 2, 1 part by mass of hindered amine (1), triazine compound (“Tinuvin (registered trademark) 400” manufactured by BASF, hereinafter referred to as “triazine (1)”) Abbreviated.) 1 part by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Example 3]
100 parts by mass of urethane prepolymer (i-3) obtained in Synthesis Example 3, 1 part by mass of hindered amine (2), and 1 part by mass of benzotriazole (1) are blended to obtain a moisture curable polyurethane hot melt resin composition. It was.

[Example 4]
100 parts by mass of urethane prepolymer (i-1) obtained in Synthesis Example 4, 1 part by mass of hindered amine (2), and 1 part by mass of triazine (1) were blended to obtain a moisture curable polyurethane hot melt resin composition. .

[Example 5]
100 parts by mass of urethane prepolymer (i-2) obtained in Synthesis Example 5, 1.5 parts by mass of hindered amine (1), 1.5 parts by mass of benzotriazole (1) are blended to form a moisture curable polyurethane hot melt resin. A composition was obtained.

[Example 6]
A moisture curable polyurethane hot melt resin composition containing 100 parts by mass of the urethane prepolymer (i-3) obtained in Synthesis Example 6, 1 part by mass of hindered amine (1), and 1.5 parts by mass of benzotriazole (1). Got.

[Comparative Example 1]
100 parts by mass of urethane prepolymer (iR-1) obtained in Comparative Synthesis Example 1, 1 part by mass of hindered amine (1), and 1 part by mass of benzotriazole (1) are blended to obtain a moisture curable polyurethane hot melt resin composition. Obtained.

[Comparative Example 2]
100 parts by mass of the urethane prepolymer (i-1) obtained in Synthesis Example 1 was used as a moisture curable polyurethane hot melt resin composition.

[Measurement method of number average molecular weight]
The number average molecular weights of polyols and the like used in the synthesis examples and comparative synthesis examples show values measured under the following conditions 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 × 30 cm) × 1 “TSKgel G4000” (7.8 mmID × 30 cm) × 1 “TSKgel G3000” (7.8 mm ID × 30 cm) × 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

[Evaluation method of initial adhesive strength]
(1) Test method for initial peeling property After the moisture-curable urethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120 ° C. for 1 hour, respectively, a corona-treated polyethylene terephthalate group having a thickness of 200 μm was used. It apply | coated so that it might become a thickness of 100 micrometers using the roll coater on the material. Thereafter, the coated surface was irradiated with 0.65 J / cm ² ultraviolet rays using a high-pressure mercury lamp, and a 200 μm thick corona-treated polyethylene terephthalate substrate was further bonded to the irradiated surface, and 3 minutes from the bonding. Later, 180 ° peel strength (N / inch) was measured in accordance with JIS K7311-1995 and evaluated as follows.
“T”: 60 N / inch or more “F”: less than 60 N / inch

(2) Test method for initial heat-resistant creep resistance After the moisture-curable urethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120 ° C. for 1 hour, a roll coater was placed on a polyethylene terephthalate substrate. It was applied to a thickness of 50 μm. Thereafter, the coated surface was irradiated with 0.65 J / cm ² of ultraviolet rays using a high-pressure mercury lamp, and MDF (medium density fiber board) was placed on the irradiated surface and bonded. 5 minutes after bonding, in a 35 ° C. atmosphere, a 75 g load was applied to the 25 mm width in the 90 ° direction, and the peel length of the polyethylene terephthalate substrate after 15 minutes was measured and evaluated as follows. .
“T”: less than 5 mm “F”: 5 mm or more

[Evaluation method of weather resistance]
The moisture curable urethane hot melt resin compositions obtained in Examples and Comparative Examples were each melted at 120 ° C. for 1 hour and then 100 μm on release paper placed on a hot plate preheated to 120 ° C. The coating was made so as to be thick. This coated product was stored at 25 ° C. and 50% humidity for 24 hours and cured to obtain a film. Using this film, a UV irradiation test was performed using a QUV accelerated weathering tester “QUV / basic” equipped with a UVA-340 bulb (UV irradiation amount: 0.78 W / m ² , temperature 45 ° C.). The weather resistance was evaluated as follows by the difference in color change (ΔE) before and after UV irradiation.
“1”; ΔE is 1 or less.
“2”; ΔE exceeds 1 and is 5 or less.
“3”; ΔE is more than 5 and 7.5 or less.
“4”; ΔE exceeds 7.5.

  It was found that the moisture-curable urethane hot melt resin composition of the present invention has excellent initial adhesive strength and weather resistance.

  On the other hand, Comparative Example 1 was an embodiment in which the compound (C) was not used and a (meth) acryloyl group was not introduced into the urethane prepolymer (i), but the initial adhesive strength was poor.

  In Comparative Example 2, the light stabilizer (iii) was not used, but the weather resistance was poor.

Claims (5)

Isocyanate group and (meth) acryloyl having as essential raw materials a polyol (A), a polyisocyanate (B), and a compound (C) having at least one (meth) acryloyl group and one hydroxyl group. A moisture-curable polyurethane hot melt resin composition comprising a urethane prepolymer (i) having a group, a photopolymerization initiator (ii), and a light stabilizer (iii). The moisture-curable polyurethane hot melt resin composition according to claim 1, wherein the compound (C) is 2-hydroxyethyl (meth) acrylate. The moisture-curable polyurethane hot according to claim 1 or 2, wherein the light stabilizer (iii) contains a hindered amine compound (iii-X) and / or a nitrogen-containing heterocyclic compound (iii-Y). Melt resin composition. The moisture according to any one of claims 1 to 3, wherein the content of the light stabilizer (iii) is in the range of 0.001 to 30 parts by mass with respect to 100 parts by mass of the urethane prepolymer (i). A curable polyurethane hot melt resin composition. A laminate comprising a base material and a cured product layer of the moisture-curable urethane hot melt resin composition according to any one of claims 1 to 4.