WO2019225148A1 - Moisture-curable urethane hot melt resin composition and multilayer body - Google Patents

Abstract

The present invention provides: a moisture-curable polyurethane hot melt resin composition which is characterized by containing (i) a urethane prepolymer having an isocyanate group, which uses, as essential starting materials, (A) a polyol, (B) a polyisocyanate and (C) a compound that has one or more polymerizable unsaturated groups and two or more hydroxyl groups, (ii) a photopolymerization initiator and (iii) a light stabilizer; and a multilayer body which comprises a layer of a cured product of this moisture-curable polyurethane hot melt resin composition. The present invention also provides a multilayer body which is characterized by comprising a base material and a layer of a cured product of the above-described moisture-curable urethane hot melt resin composition. It is preferable that the light stabilizer (iii) contains a hindered amine compound (iii-X) and/or a nitrogen-containing heterocyclic compound (iii-Y).

Description

Moisture curable urethane hot melt resin composition and laminate

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 moisture-curable urethane hot-melt resin composition is characterized by being solvent-free as with other hot-melt adhesives, and in addition to obtaining initial adhesive strength by cooling and solidification, and further, about 24 to 72 hours after adhesion. By reacting in the air or with the moisture of the adherend within this time, it is possible to obtain the final adhesive strength and heat resistance that cannot be expressed by other hot melt adhesives. However, as with other hot melt adhesives, it is not easy to further increase the initial adhesive strength only by cooling and solidifying.

As a method that can solve this problem, a method of introducing a polymerizable unsaturated group at the end of a urethane prepolymer using 2-hydroxyethyl acrylate or the like is disclosed (for example, see Patent Document 1). . This method has a problem that the final adhesive strength is inferior although sufficient initial adhesive strength can be obtained by ultraviolet curing.

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

International Publication No. 2008/093653

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, final 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 polymerizable unsaturated group and having at least two hydroxyl groups. A moisture curable polyurethane hot melt resin composition characterized by containing a urethane prepolymer (i), a photopolymerization initiator (ii), and a light stabilizer (iii), and a cured product layer thereof, The laminated body which has is provided.

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

The moisture curable urethane hot melt resin composition of the present invention comprises a polyol (A), a polyisocyanate (B), a compound having one or more polymerizable unsaturated groups and two or more hydroxyl groups (C ) And a urethane prepolymer having an isocyanate group (i) a photopolymerization initiator (ii) and a light stabilizer (iii).

The urethane prepolymer (i) is an essential raw material comprising a polyol (A), a polyisocyanate (B), and a compound (C) having one or more polymerizable unsaturated groups and two or more hydroxyl groups. Obtained and having an isocyanate group.

As the polyol (A), for example, polyester polyol, polycaprolactone polyol, polyether polyol, polycarbonate polyol, acrylic polyol, polyurethane polyol and the like can be used. 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 that a more excellent mechanical strength of the film can be obtained. . In addition, the number average molecular weight of the said polyol (A) shows the value measured by the gel permeation chromatography (GPC) method.

As for the amount of the polyol (A) used, polyol (A), polyisocyanate (B), compound (C) and photopolymerization are started from the point that even better adhesive strength and mechanical strength of the film can be obtained. The total mass of the agent (ii) and the light stabilizer (iii) is preferably in the range of 50 to 95% by mass, and more preferably in the range of 60 to 90% by 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.

As the amount of the polyisocyanate (B) used, the polyol (A), the polyisocyanate (B), the compound (C), and photopolymerization are obtained from the viewpoint that a further excellent adhesive strength and mechanical strength of the film can be obtained. It is preferably in the range of 1 to 50% by weight, more preferably in the range of 3 to 40% by weight, based on the total weight of the initiator (ii) and the light stabilizer (iii).

The compound (C) has one or more polymerizable unsaturated groups and two or more hydroxyl groups. By using this compound (C) as a raw material for the urethane prepolymer (i), a polymerizable unsaturated group can be introduced into the molecule of the urethane prepolymer (i). Adhesive strength can be obtained. Furthermore, since the urethane prepolymer (i) has an isocyanate group at the molecular end, excellent final adhesive strength can be obtained by moisture curing.

Examples of the compound (C) include a compound represented by the following general formula (1), a compound represented by the following general formula (2), a compound represented by the following general formula (3), and the following general formula (4). The compound shown, the compound shown by the following general formula (5), the compound shown by the following general formula (6), etc. can be used.

(In general formula (1), R ¹ represents a structure having at least one atomic group containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms.)

(In the general formula (2), R ² and R ⁴ each independently represent a structure having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group, and R ³ has 1 to 5 carbon atoms. Represents an alkylene group of

(In general formula (3), R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.)

(In the general formula (4), R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 3)

(In General Formula (5), R ⁸ , R ⁹ and R ¹⁰ each represent a hydrogen atom or a methyl group.)

(In General Formula (6), R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each represent a hydrogen atom or a methyl group.)

R ¹ in the general formula (1) represents a structure having two or more atomic groups containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms. For example, pentaerythritol di (meth) acrylate has a structure in which R ¹ in the general formula (1) has two atomic groups containing a polymerizable unsaturated group in the side chain of a propylene group having 3 carbon atoms.

Specific examples of the compound represented by the general formula (1) include, for example, pentaerythritol di (meth) acrylate [dimethylolpropane di (meth) acrylate], dimethylolmethane di (meth) acrylate (general formula (1) R ^{1 in} them has 3 carbon atoms and has 2 atomic groups having a polymerizable unsaturated group.), Diethylolmethane di (meth) acrylate, diethylolpropane di (meth) acrylate (R ¹ in the general formula (1) has 5 carbon atoms and has 2 atomic groups having a polymerizable unsaturated group), dipropanolmethane di (meth) acrylate, dipropanol propanedioic R ¹ in (meth) acrylate (formula (1) is of a carbon atoms 7, der having two atomic group having a polymerizable unsaturated group .), Di-butanol methane di R ¹ in (meth) acrylate, di-butanol propane di (meth) acrylate (Formula (1) is of a carbon atoms 9, an atomic group having a polymerizable unsaturated group 2) 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 pentaerythritol di (meth) acrylate and / or dimethylolmethane di (meth) acrylate from the viewpoint that a further excellent initial adhesive strength can be obtained.

In the present invention, “(meth) acrylate” refers to either one or both of acrylate and methacrylate.

R ² and R ⁴ in the general formula (2) have a structure having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group. In the general formula (2), it has a total of two or more structures having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group, preferably in the range of 2 or more and 5 or less, More preferably, it has in the range of 2 or more and 3 or less.

R ³ in the general formula (2) represents an alkylene group having 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentyl group.

Specific examples of the compound represented by the general formula (2) include, for example, bis (3-acryloyloxy-2-hydroxypropoxy) methane (R ² and R ⁴ in the general formula (2) are those having 2 carbon atoms. 1 having an atomic group having a polymerizable unsaturated group, and R ³ is one having 1 carbon atom.), 1,2-bis (3-acryloyloxy-2-hydroxypropoxy) ethane ( R ² and R ⁴ in the general formula (2) are those having 2 carbon atoms, having one atomic group having a polymerizable unsaturated group, and R ³ is having 2 carbon atoms. ), 1,3-bis (3-acryloyloxy-2-hydroxypropoxy) propane (wherein R ² and R ⁴ in the general formula (2) have ² carbon atoms and have an atomic group having a polymerizable unsaturated group) are those having one 1, R ³ is a carbon atom 3 is of.), 1,4-bis ^{R 2} and ^{R 4} in (3-acryloyloxy-2-hydroxypropoxy) butane (formula (2) by way of 2 carbon atoms, a polymerizable unsaturated And R ³ has 4 carbon atoms.), 1,5-bis (3-acryloyloxy-2-hydroxypropoxy) pentane (in general formula (2)) And R ² and R ⁴ have 2 carbon atoms, have one atomic group having a polymerizable unsaturated group, and R ³ has 5 carbon atoms). it can. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use 1,4-bis (3-acryloyloxy-2-hydroxypropoxy) butane from the viewpoint that a further excellent initial adhesive strength can be obtained.

As the use amount of the compound (C), the polyol (A), the polyisocyanate (B), the compound (C), the photopolymerization initiator (ii), and the light stability are obtained from the point that even better initial adhesive strength is obtained. The total mass of the agent (iii) is preferably in the range of 0.01 to 50% by mass, more preferably in the range of 0.1 to 30% by mass, still more preferably in the range of 0.5 to 20% by mass. A range of ˜15% by weight is particularly preferred.

The urethane prepolymer (i) is obtained by reacting the polyol (A), the polyisocyanate (B) and the compound (C), and the hydroxyl group of the compound (C) is polyisocyanate (B). ) To form a cross-linked structure by reacting with moisture present in the air or in the substrate to which the urethane prepolymer is applied. It has an isocyanate group at the molecular end.

As a method for producing the urethane prepolymer (i), for example, the polyisocyanate (B) is put into a reaction vessel containing the polyol (A) and the compound (C), and the isocyanate group contained in the polyisocyanate (B). However, it can manufacture by making it react on the conditions which become excess with respect to the hydroxyl group which the said polyol (A) and compound (C) have.

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 standpoint of obtaining even better initial and final adhesive strengths, it is preferably in the range of 1.1 to 10, and more preferably in the range of 1.15 to 8.

The isocyanate group content (hereinafter abbreviated as “NCO%”) of the urethane prepolymer (i) is in the range of 1 to 10% by mass from the standpoint of obtaining even better final adhesive strength. The range of 1.5 to 8% by mass is more preferable. The NCO% of the urethane prepolymer (i) is a value measured by potentiometric titration in accordance with JISK1603-1: 2007.

The polymerizable unsaturated group concentration of the urethane prepolymer (i) is preferably in the range of 0.0004 to 2 mol / kg, and more preferably in the range of 0.001 to 1 mol / kg. In addition, the polymerizable unsaturated group density | concentration of the said urethane prepolymer (i) shows the value computed based on the used reaction raw material.

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), a polyol (A), a polyisocyanate (B), a compound (C), and a photoinitiator (ii) from the point which can obtain the further outstanding ultraviolet-curing property. Is preferably in the range of 0.0001 to 10% by mass, and more preferably in the range of 0.005 to 5% by mass in the total mass of the light stabilizer (iii).

The light stabilizer (iii) is an essential component for obtaining excellent weather resistance. 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 faithfully simulates a 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 hindered amine compounds (iii-X), nitrogen-containing heterocyclic compounds (iii-Y), thiol compounds, thioether compounds, benzophenone compounds, and benzoate compounds. These light stabilizers (iii) may be used alone or in combination of two or more. Among these, it is preferable to use the hindered amine compound (iii-X) and / or the nitrogen-containing heterocyclic compound (iii-Y) from the viewpoint that a further excellent weather resistance can be 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 9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione and the like can be used. 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′-hydride) Roxy-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 Using triazine compounds such as 5-triazine. These triazole compounds may be used alone or in combination of two or more.

The amount of the light stabilizer (iii) used is in the range of 0.001 to 20 parts by mass with respect to 100 parts by mass of the urethane prepolymer (i) from the viewpoint of obtaining even better weather resistance. The range of 0.01 to 10 parts by mass is more preferable, the range of 0.1 to 5 parts by mass is still more preferable, and the range of 0.5 to 3 parts by mass is particularly preferable.

When the hindered amine compound (iii-X) and the nitrogen-containing heterocyclic compound (iii-Y) are used in combination, the mass ratio [(iii-X) / (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.

Next, the laminate of the present invention will be described.

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.

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

The cured product layer of the moisture curable urethane hot melt composition is appropriately determined according to the intended use, and is, for example, in the range of 0.001 to 3 cm.

The applied moisture curable urethane hot melt composition can obtain excellent initial adhesive strength by irradiating 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 from the viewpoint that a further excellent initial adhesive strength is obtained. It may be in the range of 5 J / cm ² . The amount of UV irradiation is based on a value measured in a wavelength range 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 using examples.

[Synthesis Example 1] Synthesis of Urethane Prepolymer (i-1) In a 2 liter four-necked flask equipped with a stirrer and a thermometer, 4 parts by mass of dimethylolmethane diacrylate, polyester polyol (1,6-hexanediol) And adipic acid, number average molecular weight: 4,500, hereinafter abbreviated as “PEs”.) 76.6 parts by mass, and under reduced pressure heating conditions, the moisture content relative to the total amount in the flask is 0.05 mass Dehydrated to%.
Next, after cooling to 70 ° C., 18.9 parts by mass of 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) was added, the temperature was raised to 100 ° C., and then a photopolymerization initiator (1-hydroxycyclohexyl) was added. 0.5 parts by mass of phenylketone (hereinafter abbreviated as “Irg184”) was added, and a urethane prepolymer (i-1) was reacted at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content was constant. ) (Polymerizable unsaturated group concentration; 0.37 mol / kg, NCO%; 3.2%).

[Synthesis Example 2] Synthesis of urethane prepolymer (i-2) 4 parts by mass of 1,4-bis (3-acryloyloxy-2-hydroxypropoxy) butane was added to a 2 liter four-necked flask equipped with a stirrer and a thermometer. And 79.9 parts by mass of PEs were dehydrated under reduced pressure heating conditions until the water content was 0.05% by mass with respect to the total amount in the flask.
Next, after cooling to 70 ° C., 15.6 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for about 3 hours, urethane prepolymer (i-2) (polymerizable unsaturated group concentration; 0.23 mol / kg, NCO%; 2.6%) was obtained.

[Synthesis Example 3] Synthesis of Urethane Prepolymer (i-3) Into a 2-liter 4-necked flask equipped with a stirrer and a thermometer, compound (3-1) (in formula (3), R ⁵ represents a hydrogen atom). R ⁶ represents a methyl group, and n represents an integer of 1.) 4 parts by mass and 79.5 parts by mass of PEs were added, and the moisture content relative to the total amount in the flask was 0.05 under reduced pressure heating conditions. It dehydrated until it became the mass%.
Next, after cooling to 70 ° C., 16 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and about 3 at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for a period of time, urethane prepolymer (i-3) (polymerizable unsaturated group concentration; 0.24 mol / kg, NCO%; 2.7%) was obtained.

[Synthesis Example 4] Synthesis of Urethane Prepolymer (i-4) Into a 2-liter 4-neck flask equipped with a stirrer and a thermometer, compound (3-2) (in formula (3), R ⁵ represents a methyl group). And R ⁶ represents a hydrogen atom, and n represents an integer of 1.) 4 parts by weight and PEs 79.9 parts by weight, and under reduced pressure heating conditions, the water content relative to the total amount in the flask was 0.05. It dehydrated until it became the mass%.
Next, after cooling to 70 ° C., 15.6 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for about 3 hours, urethane prepolymer (i-4) (polymerizable unsaturated group concentration; 0.23 mol / kg, NCO%; 2.5%) was obtained.

[Synthesis Example 5] Synthesis of Urethane Prepolymer (i-5) Into a 2 liter 4-neck flask equipped with a stirrer and a thermometer, compound (4-1) (in formula (4), R ⁷ represents a hydrogen atom). 4 wherein n represents an integer of 3) and 79.9 parts by mass of PEs were charged and dehydrated under reduced pressure heating until the water content was 0.05% by mass relative to the total amount in the flask.
Next, after cooling to 70 ° C., 15.6 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for about 3 hours, urethane prepolymer (i-5) (polymerizable unsaturated group concentration; 0.23 mol / kg, NCO%; 2.6%) was obtained.

[Synthesis Example 6] Synthesis of Urethane Prepolymer (i-6) Compound (5-1) (in formula (5), R ⁸ represents a hydrogen atom) in a 2-liter 4-neck flask equipped with a stirrer and a thermometer. And R ⁹ and R ¹⁰ each represent a methyl group.) 4 parts by mass and 81.5 parts by mass of PEs, and under reduced pressure heating conditions until the water content becomes 0.05% by mass with respect to the total amount in the flask Dehydrated.
Next, after cooling to 70 ° C., 14 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg184 was added, and about 3 at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for a period of time, urethane prepolymer (i-6) (polymerizable unsaturated group concentration; 0.16 mol / kg, NCO%; 2.2%) was obtained.

[Synthesis Example 7] Synthesis of Urethane Prepolymer (i-7) To a 2-liter 4-neck flask equipped with a stirrer and a thermometer, compound (6-1) (in formula (6), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ all represent a methyl group.) 4 parts by mass and 82.5 parts by mass of PEs were added and dehydrated under reduced pressure heating conditions until the water content was 0.05% by mass with respect to the total amount in the flask. did.
Next, after cooling to 70 ° C., 13 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and about 3 at 110 ° C. until the isocyanate group content became constant in a nitrogen atmosphere. By reacting for a period of time, urethane prepolymer (i-7) (polymerizable unsaturated group concentration; 0.13 mol / kg, NCO%; 2.1%) was obtained.

[Comparative Synthesis Example 1] Synthesis of Urethane Prepolymer (iR-1) A 2 liter 4-necked flask equipped with a stirrer and a thermometer was charged with 89.5 parts by mass of PEs, and the water content relative to the total amount in the flask under reduced pressure heating conditions. Was dehydrated to 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 mixture was reacted at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant. Polymer (iR-1) (polymerizable unsaturated group concentration; 0 mol / kg, NCO%; 1.7%) was obtained.

[Comparative Synthesis Example 2] Synthesis of urethane prepolymer (iR-2) 87.2 parts by mass of PEs was charged into a 2 liter four-necked flask equipped with a stirrer and a thermometer, and the water content relative to the total amount in the flask under reduced pressure heating conditions. Was dehydrated to 0.05 mass%.
Next, after cooling to 70 ° C., 10.3 parts by mass of MDI was added, the temperature was raised to 100 ° C., 0.5 part by mass of Irg 184 was added, and the content of the isocyanate group was kept constant at 110 ° C. under a nitrogen atmosphere. After reacting for about 3 hours, 2 parts by weight of 2-hydroxyethyl acrylate (hereinafter abbreviated as “HEA”) was added and reacted for about 1 hour to react with the urethane prepolymer (iR-2) (polymerizable unsaturated group concentration). 0.17 mol / kg, NCO%; 1.0%).

[Example 1]
100 parts by mass of the urethane prepolymer (i-1) obtained in Synthesis Example 1, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), bis (1,2,2,6,6) sebacate -Pentamethylpiperidin-4-yl) (hereinafter abbreviated as "hindered amine (1)") 1 part by mass, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl]- One part by weight of 2H-benzotriazole (hereinafter abbreviated as “benzotriazole (1)”) 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, 0.5 part by mass of photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1 part by mass of hindered amine (1), triazine compound (BASF Corporation) “Tinuvin (registered trademark) 400” (hereinafter abbreviated as “triazine (1)”) 1 part by mass was blended to obtain a moisture-curable polyurethane hot melt resin composition.

[Example 3]
100 parts by mass of the urethane prepolymer (i-3) obtained in Synthesis Example 3, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1 part by mass of a hindered amine (2), and benzotriazole (1) 1 part by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Example 4]
100 parts by mass of urethane prepolymer (i-4) obtained in Synthesis Example 4, 0.5 part by mass of photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1 part by mass of hindered amine (2), triazine (1) 1 By blending parts by mass, a moisture-curable polyurethane hot melt resin composition was obtained.

[Example 5]
100 parts by mass of the urethane prepolymer (i-5) obtained in Synthesis Example 5, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1.5 parts by mass of hindered amine (1), benzotriazole ( 1) 1.5 parts by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Example 6]
100 parts by mass of urethane prepolymer (i-6) obtained in Synthesis Example 6, 0.5 part by mass of photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1 part by mass of hindered amine (1), benzotriazole (1) 1.5 parts by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Example 7]
100 parts by mass of the urethane prepolymer (i-7) obtained in Synthesis Example 7, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1.5 parts by mass of hindered amine (1), benzotriazole ( 1) 1 part by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Comparative Example 1]
100 parts by mass of the 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 (iR-2) obtained in Comparative Synthesis Example 2, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone), 1 part by mass of hindered amine (1), benzotriazole ( 1) 1 part by mass was blended to obtain a moisture curable polyurethane hot melt resin composition.

[Comparative Example 3]
100 parts by mass of the urethane prepolymer (i-1) obtained in Synthesis Example 1 and 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) were blended to prepare a moisture-curable polyurethane hot melt resin composition. Obtained.

[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 final bond strength]
The moisture curable urethane hot melt resin compositions obtained in the examples and comparative examples were melted at 120 ° C. for 1 hour, respectively, and then a roll coater was used on the polyethylene terephthalate substrate so that the thickness was 50 μm. Applied. 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. The test piece was cured for 72 hours in an atmosphere of 23 ° C. and 50% humidity, and then subjected to a load of 500 g with respect to a width of 25 mm in a 90 ° direction in an atmosphere of 80 ° C., and polyethylene after 15 minutes after 1 hour. The peel length of the terephthalate substrate 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 conducted 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.

The moisture curable urethane hot melt resin composition of the present invention was found to have excellent initial adhesive strength, final adhesive strength, and weather resistance.

On the other hand, Comparative Example 1 was an embodiment in which the compound (C) was not used and no polymerizable unsaturated group was introduced into the urethane prepolymer (i), but the initial adhesive strength was poor.

Comparative Example 2 was an embodiment in which 2-hydroxyethyl acrylate was used as a raw material instead of the compound (C), but the final adhesive strength was poor.

Comparative Example 3 was an embodiment in which the light stabilizer (iii) was not used, but the weather resistance was poor.

Claims (7)

1. A urethane prepolymer having an isocyanate group, comprising as an essential raw material a polyol (A), a polyisocyanate (B), and a compound (C) having at least one polymerizable unsaturated group and having at least two hydroxyl groups. A moisture-curable polyurethane hot melt resin composition comprising a polymer (i), a photopolymerization initiator (ii), and a light stabilizer (iii).
2. The compound (C) is a compound represented by the following general formula (1), a compound represented by the following general formula (2), a compound represented by the following general formula (3), a compound represented by the following general formula (4) The moisture-curable urethane hot melt resin composition according to claim 1, which is at least one selected from the group consisting of a compound represented by the following general formula (5) and a compound represented by the following general formula (6).
   

   

   (In general formula (1), R ¹ represents a structure having at least one atomic group containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms.)
   

   

   (In the general formula (2), R ² and R ⁴ each independently represent a structure having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group, and R ³ has 1 to 5 carbon atoms. Represents an alkylene group of
   

   

   (In general formula (3), R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.)
   

   

   (In the general formula (4), R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 3)
   

   

   (In General Formula (5), R ⁸ , R ⁹ and R ¹⁰ each represent a hydrogen atom or a methyl group.)
   

   

   (In General Formula (6), R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each represent a hydrogen atom or a methyl group.)
3. The moisture-curable urethane hot melt resin composition according to claim 1 or 2, wherein the urethane prepolymer (i) has a polymerizable unsaturated group concentration in the range of 0.0004 to 2 mol / kg.
4. The moisture curable urethane hot melt resin composition according to any one of claims 1 to 3, wherein the urethane prepolymer (i) has an isocyanate group content of 1 to 10% by mass.
5. The light stabilizer (iii) contains a hindered amine compound (iii-X) and / or a nitrogen-containing heterocyclic compound (iii-Y) according to any one of claims 1 to 4. Moisture curable polyurethane hot melt resin composition.
6. The moisture according to any one of claims 1 to 5, wherein a content of the light stabilizer (iii) is in a range of 0.001 to 20 parts by mass with respect to 100 parts by mass of the urethane prepolymer (i). A curable polyurethane hot melt resin composition.
7. 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 6.