KR20210008043A - Moisture-curable urethane hot melt resin composition, and laminate - Google Patents

Abstract

The present invention is a urethane prepolymer having an isocyanate group, which is made of a polyol (A), a polyisocyanate (B), and a compound (C) having at least one polymerizable unsaturated group and having at least two hydroxyl groups as essential raw materials ( It is to provide a moisture-curable polyurethane hot-melt resin composition comprising i), a photopolymerization initiator (ii), and a light stabilizer (iii), and a laminate having a cured product layer thereof. Further, the present invention provides a laminate comprising a substrate and a cured product layer of the 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 compositions containing urethane prepolymer as a main component are widely used for bonding metal materials, wood materials, plastics, rubber, textile products, synthetic leather, paper products, etc., and It is used in various fields such as decorative plates, automobile interior materials, and medical care.

The characteristics of the moisture-curable urethane hot-melt resin composition are solvent-free like other hot-melt adhesives, and in addition to obtaining initial adhesive strength by cooling and solidification, moisture in the air or the adherend within a period of about 24 to 72 hours after adhesion By reacting, the final adhesive strength and heat resistance that cannot be expressed in other hot melt adhesives are obtained. However, like other hot melt adhesives, it is not easy to further increase the initial adhesive strength only by cooling and solidifying.

As a method capable of solving this problem, a method of introducing a polymerizable unsaturated group to the terminal of a urethane prepolymer using 2-hydroxyethyl acrylate or the like is disclosed (see, for example, Patent Document 1). In this method, a sufficient initial adhesive strength is obtained by UV curing, but there is a problem that the final adhesive strength is inferior.

In addition, in order to promote use in various fields, the demand for weather resistance for UV exposure is also increasing, and development of materials satisfying all of them 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 excellent in initial adhesive strength, final adhesive strength, and weather resistance.

The present invention is a urethane prepolymer having an isocyanate group, which is made of a polyol (A), a polyisocyanate (B), and a compound (C) having at least one polymerizable unsaturated group and having at least two hydroxyl groups as essential raw materials ( It is to provide a moisture-curable polyurethane hot-melt resin composition comprising i), a photopolymerization initiator (ii), and a light stabilizer (iii), and a laminate having a cured product layer thereof.

The moisture curing 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), and a compound (C) having at least one polymerizable unsaturated group, and having at least two hydroxyl groups as essential raw materials. , A urethane prepolymer having an isocyanate group (i), a photopolymerization initiator (ii), and a light stabilizer (iii).

The urethane prepolymer (i) is obtained by using a polyol (A), a polyisocyanate (B), and a compound (C) having one or more polymerizable unsaturated groups, and having two or more hydroxyl groups as essential raw materials, It has 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, and more preferably in the range of 500 to 100,000, from the viewpoint of obtaining even more excellent mechanical strength of the film. In addition, the number average molecular weight of the polyol (A) represents a value measured by a gel permeation chromatography (GPC) method.

As the amount of the polyol (A) to be used, the polyol (A), the polyisocyanate (B), the compound (C), the photopolymerization initiator (ii), and the photostabilizer are obtained from the viewpoint of obtaining even more excellent adhesive strength and mechanical strength of the film. It is preferably in the range of 50 to 95% by mass, and more preferably in the range of 60 to 90% by mass of the total mass with (iii).

Examples of the polyisocyanate (B) include aliphatic polyisocyanates or alicyclic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate. ; Aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, xylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; These isocyanurates 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, from the viewpoint of obtaining even more excellent adhesive strength and mechanical strength of the film, polyol (A), polyisocyanate (B), compound (C), photopolymerization initiator (ii), and light eyes It is preferably in the range of 1 to 50% by mass, and more preferably in the range of 3 to 40% by mass of the total mass of the tablet (iii).

The compound (C) has one or more polymerizable unsaturated groups, and has 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), and excellent initial adhesive strength can be obtained by irradiation with ultraviolet rays or the like. have. Further, since the urethane prepolymer (i) has an isocyanate group at the molecular end, it is possible to obtain a final adhesive strength superior in moisture curing.

As the compound (C), for example, 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) A compound represented by, a compound represented by the following general formula (5), a compound represented by the following general formula (6), and the like 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 straight-chain alkylene group having 1 to 9 carbon atoms)

(In 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 represents an alkylene group having 1 to 5 carbon atoms. Indicate)

(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 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, in pentaerythritol di(meth)acrylate, R ¹ in General Formula (1) has a structure having 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 [dimethylolpropanedi(meth)acrylate], dimethylolmethanedi(meth)acrylate (general R ¹ in formula (1) has 3 carbon atoms and has two atomic groups having a polymerizable unsaturated group), diethylolmethanedi(meth)acrylate, diethylolpropanedi(meth)acrylate ( R ¹ in the general formula (1) has 5 carbon atoms and has two atomic groups having a polymerizable unsaturated group), dipropanolmethanedi(meth)acrylate, dipropanolpropanedi(meth)acrylate (general R ¹ in formula (1) has 7 carbon atoms and has two atomic groups having a polymerizable unsaturated group), dibutanolmethanedi(meth)acrylate, dibutanolpropanedi(meth)acrylate (general formula In (1), R ¹ has 9 carbon atoms and has two atomic groups having a polymerizable unsaturated group) 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 dimethylol methane di (meth) acrylate from the viewpoint of obtaining even more excellent initial adhesive strength.

In addition, in this invention, "(meth)acrylate" means either or both of an acrylate and a methacrylate.

In the general formula (2), R ² and R ⁴ have an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group. In the general formula (2), 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 two or more and five or less, and more preferably two or more and three or less Have in the range of.

In addition, 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.

As a specific example of the compound represented by the general formula (2), for example, bis(3-acryloyloxy-2-hydroxypropoxy)methane (R ² and R ⁴ in the general formula (2) are carbon atoms It has the number of 2, has one atomic group having a polymerizable unsaturated group, and R ³ has 1 carbon atom), 1,2-bis(3-acryloyloxy-2-hydroxypropoxy)ethane (general In formula (2), R ² and R ⁴ have 2 carbon atoms, have one atomic group having a polymerizable unsaturated group, and R ³ is 2 carbon atoms), 1,3-bis(3-acrylo) Yloxy-2-hydroxypropoxy) propane (R ² and R ⁴ in the general formula (2) have 2 carbon atoms, have one atomic group having a polymerizable unsaturated group, and R ³ is ), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (R ² and R ⁴ in general formula (2) have 2 carbon atoms and an atomic group having a polymerizable unsaturated group And R ³ is one having 4 carbon atoms), 1,5-bis(3-acryloyloxy-2-hydroxypropoxy)pentane (R ² and R ⁴ in the general formula (2) are It has 2 carbon atoms, has one atomic group having a polymerizable unsaturated group, and R ³ has 5 carbon atoms. 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 of obtaining even more excellent initial adhesive strength.

The amount of compound (C) used is the total mass of polyol (A), polyisocyanate (B), compound (C), photopolymerization initiator (ii), and light stabilizer (iii) from the viewpoint of obtaining even more excellent initial adhesive strength. It is preferably in the range of 0.01 to 50% by mass, more preferably in the range of 0.1 to 30% by mass, more preferably in the range of 0.5 to 20% by mass, and particularly preferably in the range of 1 to 15% by mass.

The urethane prepolymer (i) is obtained by reacting the polyol (A) with the polyisocyanate (B) and the compound (C), and the hydroxyl group of the compound (C) reacts with the polyisocyanate (B), A polymerizable unsaturated group is introduced inside, and an isocyanate group capable of forming a crosslinked structure by reacting with moisture present in the air or in the gas to which the urethane prepolymer is applied has at the molecular end.

As a method for producing the urethane prepolymer (i), for example, polyisocyanate (B) is put in a reaction vessel containing the polyol (A) and compound (C), and the isocyanate group of the polyisocyanate (B), The polyol (A) and the compound (C) can be produced by reacting in excess of the hydroxyl groups contained therein.

When preparing the urethane prepolymer (i), the equivalent ratio of the isocyanate group of the polyisocyanate (B) and the hydroxyl group of the polyol (A) and compound (C) (isocyanate group/hydroxyl group) is further excellent. From the viewpoint of obtaining initial adhesive strength and final adhesive strength, it is preferably in the range of 1.1 to 10, and more preferably in the range of 1.15 to 8.

The content of isocyanate groups in the urethane prepolymer (i) (hereinafter, abbreviated as ``NCO%'') is preferably in the range of 1 to 10% by mass, and 1.5 to 8% by mass, from the viewpoint of obtaining even more excellent final adhesive strength. The range of% is more preferable. In addition, the NCO% of the urethane prepolymer (i) represents a value measured by a potentiometric titration method in accordance with JISK1603-1:2007.

The concentration of the polymerizable unsaturated group 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 concentration of the polymerizable unsaturated group of the urethane prepolymer (i) represents a value calculated based on the reaction raw material used.

Examples of the photopolymerization initiator (ii) include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxy Oxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone, thioxanthone derivative, 2,2'-dimethoxy-1,2-diphenylethan-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.

The total mass of the polyol (A), polyisocyanate (B), compound (C), photoinitiator (ii), and light stabilizer (iii) as the amount of the photopolymerization initiator (ii) to be used, since even more excellent ultraviolet curing properties are obtained. It 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.

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

As the light stabilizer (iii), for example, a hindered amine compound (iii-X), a nitrogen-containing heterocyclic compound (iii-Y), a thiol compound, a thioether compound, a benzophenone compound, a benzoate compound, and the like can be used. I can. 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 of obtaining even more excellent weather resistance, and a hindered amine compound (iii- It is more preferable to use X) and a nitrogen-containing heterocyclic compound (iii-Y) together.

Examples of the hindered amine compound (iii-X) include bis sebacic acid (2,2,6,6-tetramethyl-4-piperidyl), bis sebacic acid (1,2,2,6, 6-pentamethylpiperidin-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-butanetetra Carboxylate, 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.

As said nitrogen-containing heterocyclic compound (iii-Y), for example, 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-Chlorobenzotriazole, 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 '-Hydroxy-3'-isobutyl-5'-propylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole , 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-5'-(1,1,3,3-tetramethyl)phenyl]benzotriazole, etc. Benzotriazole compound or {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 ) Triazine compounds, such as -1,3,5-triazine, etc. are used. These triazole compounds may be used alone or in combination of two or more.

The amount of light stabilizer (iii) used is preferably in the range of 0.001 to 20 parts by mass, and more preferably in the range of 0.01 to 10 parts by mass, based on 100 parts by mass of the urethane prepolymer (i), from the viewpoint of obtaining even more excellent weather resistance. It is preferable, and a range of 0.1 to 5 parts by mass is more preferable, and a 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 obtained because even more excellent weather resistance is obtained. )] 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 preferably 70% by mass or more in the light stabilizer (iii) from the viewpoint of obtaining even more excellent weather resistance. And 80 mass% or more is more preferable, and 90 mass% or more is still more preferable.

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, but may contain other additives as necessary. .

As the above other additives, for example, curing catalysts, tackifiers, plasticizers, stabilizers, fillers, dyes, pigments, optical brighteners, silane coupling agents, waxes, thermoplastic resins, and the like can be used. 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 substrate and a cured product layer of the moisture-curable urethane hot-melt resin composition.

Examples of the substrate include wooden substrates such as plywood, MDF (medium density fiber board), and particle board; Metal substrates such as aluminum and iron; Sheet substrates obtained using resins such as polyester, polyamide, polystyrene, polycarbonate, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyethylene, and polypropylene; Calcium silicate plate; G; Metal foil; Veneer; Fiber substrates such as nonwoven fabrics and woven fabrics; Synthetic Leather; G; Rubber substrate; A glass substrate or the like can be used. The thickness of the substrate is determined depending on the intended use, but is in the range of 1 to 500 mm, for example.

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 used as a roll coater, spray coater, T-die coater, knife coater. , A coater method such as a comma coater; A method of applying to a substrate using a precision method such as dispenser, spray, inkjet printing, screen printing, offset printing, etc. can be mentioned.

As the cured product layer of the moisture-curable urethane hot melt composition, it is appropriately determined depending on the intended use, but is in the range of 0.001 to 3 cm, for example.

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

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

The irradiation amount of the ultraviolet rays is preferably in the range of 0.05 to 5 J/cm 2, more preferably 0.1 to 3 J/cm 2, and particularly preferably 0.3 to 1.5 J/cm 2 from the viewpoint of obtaining even more excellent initial adhesive strength. In addition, the irradiation amount of the ultraviolet rays 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.

After the ultraviolet irradiation, in order to age the isocyanate groups of the urethane prepolymer (i), it is preferable to cure for 1 to 3 days at a temperature of preferably 20 to 40°C.

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.

(Example)

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 4-neck flask equipped with a stirrer and a thermometer, 4 parts by mass of dimethylolmethane diacrylate and a polyester polyol (reactant of 1,6-hexanediol and adipic acid, number average molecular weight; 4,500, or less `` (Abbreviated as "PEs") 76.6 parts by mass was added, and under reduced pressure heating conditions, dehydration was performed until the moisture relative to the total amount in the flask became 0.05% by mass.

Subsequently, 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 a photopolymerization initiator (1-hydroxycyclohexylphenyl Add 0.5 parts by mass of ketone, hereinafter abbreviated as "Irg184"), and react in a nitrogen atmosphere at 110°C for about 3 hours until the content of isocyanate groups becomes constant, thereby making the urethane prepolymer (i-1) (polymerizable unsaturated group Concentration; 0.37 mol/kg, NCO%; 3.2%) was obtained.

[Synthesis Example 2] Synthesis of urethane prepolymer (i-2)

4 parts by mass of 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane and 79.9 parts by mass of PEs were added to a 2-liter 4-neck flask equipped with a stirrer and thermometer, and under reduced pressure heating conditions Then, it was dehydrated until the water content of the flask was 0.05% by mass.

Then, after cooling to 70°C, 15.6 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and the reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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)

In a 2-liter 4-neck flask equipped with a stirrer and a thermometer, compound (3-1) (in general formula (3), R ⁵ represents a hydrogen atom, R ⁶ represents a methyl group, and n represents an integer of 1. One) was added to 4 parts by mass and 79.5 parts by mass of PEs, and dehydrated under reduced pressure heating conditions until the water content in the flask was 0.05% by mass.

Then, after cooling to 70°C, 16 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and the reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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)

In a 2-liter 4-neck flask equipped with a stirrer and a thermometer, compound (3-2) (in general formula (3), R ⁵ represents a methyl group, R ⁶ represents a hydrogen atom, and n represents an integer of 1). Thing) was added 4 parts by mass and 79.9 parts by mass of PEs, and dehydrated under reduced pressure heating conditions until the water content of the flask was 0.05% by mass.

Then, after cooling to 70°C, 15.6 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and the reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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)

In a 2-liter 4-neck flask equipped with a stirrer and a thermometer, compound (4-1) (in the general formula (4), R ⁷ represents a hydrogen atom, n represents an integer of 3) and 4 parts by mass , 79.9 parts by mass of PEs were added, and dehydration was carried out under reduced pressure heating conditions until the water content in the flask was 0.05% by mass.

Then, after cooling to 70°C, 15.6 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and the reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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)

4 mass of compound (5-1) (in general formula (5), R ⁸ represents a hydrogen atom and R ⁹ and R ¹⁰ represent a methyl group) into a 2-liter 4-neck flask equipped with a stirrer and thermometer A portion and 81.5 parts by mass of PEs were added, and dehydration was performed under reduced pressure heating conditions until the water content in the flask was 0.05% by mass.

Then, after cooling to 70°C, 14 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and the reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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, 4 parts by mass of compound (6-1) (in the general formula (6), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ all represent a methyl group) Wow, 82.5 parts by mass of PEs was added, and under reduced pressure heating conditions, dehydration was performed until the moisture relative to the total amount in the flask became 0.05% by mass.

Then, after cooling to 70°C, 13 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and reaction was performed at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. As a result, a 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)

Into a 2-liter 4-neck flask equipped with a stirrer and a thermometer, 89.5 parts by mass of PEs was put, and under reduced pressure heating conditions, dehydration was performed until the moisture relative to the total amount in the flask became 0.05% by mass.

Subsequently, after cooling to 70° C., 10.5 parts by mass of MDI was added, the temperature was raised to 100° C., and then reacted at 110° C. for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere to prepare a urethane prepolymer (iR-1 ) (Polymerizable unsaturated group concentration; 0 mol/kg, NCO%; 1.7%) was obtained.

[Comparative Synthesis Example 2] Synthesis of Urethane Prepolymer (iR-2)

Into a 2-liter 4-neck flask equipped with a stirrer and a thermometer, 87.2 parts by mass of PEs was put, and under reduced pressure heating conditions, dehydration was performed until the moisture relative to the total amount in the flask became 0.05% by mass.

Subsequently, after cooling to 70°C, 10.3 parts by mass of MDI was added, the temperature was raised to 100°C, 0.5 parts by mass of Irg184 was added, and reacted at 110°C for about 3 hours until the isocyanate group content became constant in a nitrogen atmosphere. , 2 parts by mass of 2-hydroxyethyl acrylate (hereinafter abbreviated as "HEA") was added and reacted for about 1 hour to make the urethane prepolymer (iR-2) (polymerizable unsaturated group concentration; 0.17 mol/kg, NCO%; 1.0%) was obtained.

[Example 1]

100 parts by mass of the urethane prepolymer (i-1) obtained in Synthesis Example 1, 0.5 parts by mass of the photopolymerization initiator (1-hydroxycyclohexylphenyl ketone), bis sebacic acid (1,2,2,6,6-pentamethylpiperi) Din-4-yl) (hereinafter abbreviated as "hindered amine (1)") 1 part by mass, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H -1 part by mass of 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 the urethane prepolymer (i-2) obtained in Synthesis Example 2, 0.5 parts by mass of a photopolymerization initiator (1-hydroxycyclohexylphenyl ketone), 1 part by mass of hindered amine (1), and a triazine compound ("Tinuvin manufactured by BASF) (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 the photopolymerization initiator (1-hydroxycyclohexylphenyl ketone), 1 part by mass of hindered amine (2), 1 part by mass of benzotriazole (1) The parts were blended to obtain a moisture-curable polyurethane hot melt resin composition.

[Example 4]

100 parts by mass of the urethane prepolymer (i-4) obtained in Synthesis Example 4, 0.5 parts by mass of the photopolymerization initiator (1-hydroxycyclohexylphenyl ketone), 1 part by mass of hindered amine (2), and 1 part by mass of triazine (1) Blended to obtain a moisture-curable polyurethane hot melt resin composition.

[Example 5]

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

[Example 6]

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

[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 photopolymerization initiator (1-hydroxycyclohexylphenyl ketone), 1 part by mass of hindered amine (1), 1 part by mass of benzotriazole (1) By blending parts by mass, a moisture-curable polyurethane hot melt resin composition was obtained.

[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-hydroxycyclohexylphenyl ketone) were blended to obtain 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 Synthesis Examples and Comparative Synthesis Examples represent values measured under the following conditions by a 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 and used.

「TSKgel G5000」(7.8㎜I.D.×30cm)×1ea

「TSKgel G4000」(7.8㎜I.D.×30cm)×1ea

「TSKgel G3000」(7.8㎜I.D.×30cm)×1ea

「TSKgel G2000」(7.8㎜I.D.×30cm)×1ea

Detector: RI (differential refractometer)

Column temperature: 40°C

Eluent: Tetrahydrofuran (THF)

Flow rate: 1.0mL/min

Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by 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 of initial peeling property

The moisture-curable urethane hot-melt resin composition obtained in Examples and Comparative Examples was melted at 120° C. for 1 hour, and then coated on a 200 μm-thick corona-treated polyethylene terephthalate substrate to a thickness of 100 μm using a roll coater. did. Thereafter, the coated surface was irradiated with UV rays of 0.65 J/cm 2 using a high-pressure mercury lamp, and a 200 μm-thick corona-treated polyethylene terephthalate substrate was further adhered to the irradiated surface, followed by 180° peeling after 3 minutes The strength (N/inch) was measured according to JISK7311-1995, and evaluated as follows.

"T"; 60N/inch or more

"F"; Less than 60N/inch

(2) Initial heat creep resistance test method

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 applied onto a polyethylene terephthalate substrate to a thickness of 50 μm using a roll coater. Thereafter, the coated surface was irradiated with an ultraviolet ray of 0.65 J/cm 2 using a high-pressure mercury lamp, and an MDF (medium density fiber board) was placed on the irradiated surface and bonded. After 5 minutes of bonding, in an atmosphere of 35°C, a load of 75 g was applied in the direction of 90° with respect to a width of 25 mm, and the peeling length of the polyethylene terephthalate substrate after 15 minutes was measured, and evaluated as follows.

"T"; Less than 5mm

"F"; 5mm or more

[Evaluation method of final adhesive strength]

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 applied onto a polyethylene terephthalate substrate to a thickness of 50 μm using a roll coater. Thereafter, the coated surface was irradiated with an ultraviolet ray of 0.65 J/cm 2 using a high-pressure mercury lamp, and an MDF (medium density fiber board) was placed on the irradiated surface and bonded. After curing this test piece in an atmosphere of 23°C and 50% humidity for 72 hours, a load of 500 g for a width of 25 mm was applied in the direction of 90° in an atmosphere of 80°C, and the peeling length of the polyethylene terephthalate substrate after 15 minutes was measured. And evaluated as follows.

"T"; Less than 5mm

"F"; 5mm or more

[Method of evaluating weatherability]

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 coated on a release paper placed on a hot plate heated at 120° C. to a thickness of 100 μm. This coated article 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 weather resistance tester "QUV/basic" equipped with a UVA-340 bulb (UV irradiation amount: 0.78 W/m 2, temperature 45°C), and the discoloration before and after UV irradiation. From the difference (ΔE), the evaluation of weather resistance was evaluated as follows.

"One"; ΔE is less than or equal to 1

"2"; ΔE greater than 1 and less than 5

"3"; ΔE greater than 5 and less than 7.5

"4"; ΔE exceeds 7.5

[Table 1]

[Table 2]

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

On the other hand, in Comparative Example 1, although the compound (C) was not used and a polymerizable unsaturated group was not introduced into the urethane prepolymer (i), the initial adhesive strength was poor.

In Comparative Example 2, 2-hydroxyethyl acrylate was used as a raw material instead of Compound (C), but the final adhesive strength was poor.

In Comparative Example 3, the light stabilizer (iii) was not used, but the weather resistance was poor.

Claims (7)

Polyol (A), polyisocyanate (B), and compound (C) having one or more polymerizable unsaturated groups and two or more hydroxyl groups as essential raw materials, urethane prepolymer (i) having an isocyanate group, photopolymerization A moisture-curable polyurethane hot melt resin composition comprising an initiator (ii) and a light stabilizer (iii). The method of claim 1,
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), and a compound represented by the following general formula (4) , A moisture-curable urethane hot melt resin composition of 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 straight-chain alkylene group having 1 to 9 carbon atoms)

(In 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 represents an alkylene group having 1 to 5 carbon atoms. Indicate)

(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 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) The method according to claim 1 or 2,
The moisture-curable urethane hot melt resin composition in which the concentration of the polymerizable unsaturated group of the urethane prepolymer (i) is in the range of 0.0004 to 2 mol/kg. The method according to any one of claims 1 to 3,
The moisture-curable urethane hot-melt resin composition wherein the urethane prepolymer (i) has an isocyanate group content in the range of 1 to 10% by mass. The method according to any one of claims 1 to 4,
The moisture-curable polyurethane hot melt resin composition wherein the light stabilizer (iii) contains a hindered amine compound (iii-X) and/or a nitrogen-containing heterocyclic compound (iii-Y). The method according to any one of claims 1 to 5,
A moisture-curable polyurethane hot-melt resin composition in which the content of the light stabilizer (iii) is in the range of 0.001 to 20 parts by mass with respect to 100 parts by mass of the urethane prepolymer (i). A laminate comprising a substrate and a cured product layer of the moisture-curable urethane hot-melt resin composition according to any one of claims 1 to 6.