JP2015052090A - Moisture-curable hot melt adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-curable hot melt adhesive which has a fast solidification rate and can exhibit excellent initial adhesive strength.SOLUTION: Provided is a moisture-curable adhesive comprising an urethane prepolymer having terminal isocyanate groups, formed by reacting a polyol compound with a polyisocyanate compound, the polyol compound including 15 to 45 wt% of a crystalline polyester polyol (A) formed by a condensation reaction of a linear polycarboxylic acid having 8 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms, 5 to 40 wt% of an amorphous polyester polyol (B) having a softening point of 40°C or less, 5 to 30 wt% of an amorphous polyester polyol (C) having a softening point of 60°C or more, and 5 to 45 wt% of a polyether polyol (D) having a number average molecular weight of 3000 or less.

Description

  The present invention relates to a moisture curable hot melt adhesive that has a high solidification rate and can exhibit excellent initial adhesive strength.

  2. Description of the Related Art Conventionally, design properties are imparted by adhering a decorative sheet with makeup such as coloring to the surface of a base material such as furniture, exterior material, and interior material using an adhesive.

  As an adhesive used for adhesion between a base material and a decorative sheet, an adhesive containing an organic solvent and a moisture curable hot melt adhesive are known. In particular, moisture-curing hot melt adhesives are often used because they do not contain volatile organic compounds (VOC) that cause sick house syndrome and are measures against occupational hygiene and environmental pollution.

  As the moisture curable hot melt adhesive, for example, a hot melt adhesive containing, as a main component, a urethane prepolymer having an isocyanate group at the molecular end is used (for example, Patent Document 1). Such a moisture-curing hot melt adhesive is applied to a substrate in a heated and melted state, and then cooled and solidified to express initial adhesive strength. After that, by leaving the substrate coated with the moisture-curable hot melt adhesive for a certain period of time, the isocyanate group reacts with the moisture contained in the atmosphere or the substrate, so that the urethane prepolymer has a crosslinked structure. The moisture curable hot melt adhesive is cured and the adhesive strength is further improved.

JP 2001-262113 A

  However, although the moisture-curing hot melt adhesive can exhibit excellent initial adhesive strength, it has a low solidification rate when it is cooled and solidified after coating. From the viewpoint of design and functionality, many substrates having a complicated shape such as a curved surface portion, a concavo-convex portion, a corner portion or a groove portion are used. When a decorative sheet is bonded to a base material using a moisture-curable hot melt adhesive while the decorative sheet is bent or bent in accordance with the shape of the base material, the applied moisture-curable hot melt is applied. It takes time for the adhesive to cool and solidify to develop the initial adhesive strength. Therefore, after the decorative sheet is bonded to the base material via the moisture-curable hot melt adhesive, before the initial adhesive strength is developed. The problem arises that the decorative sheet that has been bent or bent peels off due to its restoring force.

  Accordingly, an object of the present invention is to provide a base material having a complicated shape with a fast solidification speed and an excellent initial adhesive strength, and adhere to an adherend such as a decorative sheet along the shape of the base material. Can be reduced after the substrate is bonded via a moisture-curable hot-melt adhesive and before the moisture-curable hot-melt adhesive develops the initial adhesive strength. It is to provide a possible moisture curable hot melt adhesive.

The moisture curable hot melt adhesive of the present invention is
15 to 45% by weight of a crystalline polyester polyol (A) obtained by condensation polymerization of a linear polycarboxylic acid having 8 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms,
Amorphous polyester polyol (B) having a softening point of 40 ° C. or lower, 5 to 40% by weight,
A polyol compound comprising 5 to 30% by weight of an amorphous polyester polyol (C) having a softening point of 60 ° C. or higher, and 5 to 45% by weight of a polyether polyol (D) having a number average molecular weight of 3000 or less; It is characterized by containing a urethane prepolymer obtained by reacting with a polyisocyanate compound and having an isocyanate group at the terminal.

  The moisture curable hot melt adhesive of the present invention is not only excellent in initial adhesive strength but also has a high solidification rate. Therefore, the moisture curable hot melt adhesive can quickly cool and solidify after coating, and can exhibit excellent initial adhesive strength at an early stage. Therefore, according to the moisture curable hot melt adhesive of the present invention, after bonding an adherend such as a decorative sheet along the shape of the base material to the base material having a complicated shape through the adhesive. Further, it is possible to reduce the peeling of the adherend from the base material until the moisture-curing hot melt adhesive is cooled and solidified to exhibit the initial adhesive strength.

  The moisture curable hot melt adhesive of the present invention contains a urethane prepolymer which is obtained by reacting a polyol compound and a polyisocyanate compound and has an isocyanate group at the terminal.

[Polyol compound]
As the polyol compound used in the present invention, a polyol compound having two or more hydroxy groups in one molecule is used. The polyol compound includes a crystalline polyester polyol (A), an amorphous polyester polyol (B) having a softening point of 40 ° C. or lower, an amorphous polyester polyol (C) having a softening point of 60 ° C. or higher, and a polyether polyol. (D) is included.

(Crystalline polyester polyol (A))
The crystalline polyester polyol (A) is obtained by condensation polymerization of a linear polycarboxylic acid having 8 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms.

  Preferred examples of the linear polycarboxylic acid having 8 to 12 carbon atoms include linear aliphatic dicarboxylic acids having 8 to 12 carbon atoms. Specific examples include sebacic acid (carbon number 10) and decamethylene dicarboxylic acid (carbon number 12).

  The linear polycarboxylic acid preferably has an even number of carbon atoms. According to the linear polycarboxylic acid having an even number of carbon atoms, it has higher crystallinity, so that it can be applied to a substrate having a complicated shape after bonding until the initial adhesive strength is expressed. A moisture-curable hot-melt adhesive that can be bonded without peeling off the adhesive can be provided.

  The linear polyol having 2 to 6 carbon atoms is preferably a linear alkylene glycol having 2 to 6 carbon atoms. Specific examples include ethylene glycol (carbon number 2), butanediol (carbon number 4), and hexanediol (carbon number 6).

  The linear polyol having 2 to 6 carbon atoms preferably has an even number of carbon atoms. A linear polyol having an even number of carbon atoms and having 2 to 6 carbon atoms has a higher crystallinity, and thus a base material having a complicated shape after bonding and until the initial adhesive strength is developed. Thus, it is possible to provide a moisture-curable hot melt adhesive that can be bonded to the object without peeling off.

  In the present invention, the crystalline polyester polyol means that the endothermic amount of the melting curve measured at a heating rate of 10 ° C./min in the differential scanning calorimetry (DSC) measurement defined in JIS K7121 is 3 cal / g. The polyester polyol which is the above is meant. In addition, the non-crystalline polyester polyol is an endothermic amount of a melting curve measured at a heating rate of 10 ° C./min in a differential scanning calorimetry (DSC) measurement specified in JIS K7121 is less than 3 cal / g. Means polyester polyol.

  The hydroxyl value of the crystalline polyester polyol (A) is preferably 5 to 200, more preferably 10 to 150, and particularly preferably 20 to 40. With a crystalline polyester polyol (A) having a hydroxyl value that is too low, the applicability of the moisture-curable hot-melt adhesive may be reduced. Further, the crystalline polyester polyol (A) having a hydroxyl value that is too high may not sufficiently improve the initial adhesive strength of the moisture-curable hot melt adhesive.

  In the present invention, the hydroxyl value of the polyester polyol or polyether polyol means the amount (g) of potassium hydroxide required to acetylate the hydroxyl group contained in 1 g of the polyester polyol or polyether polyol. Specifically, it can be measured by acetylating a hydroxyl group in a polyester polyol or polyether polyol with acetic anhydride and titrating unused acetic anhydride with potassium hydroxide.

  The number average molecular weight of the crystalline polyester polyol (A) is preferably 1000 to 20000, more preferably 1000 to 10000, and particularly preferably 1000 to 5000. If the number average molecular weight is too small, the crystalline polyester polyol (A) may not be able to sufficiently improve the initial adhesive strength of the moisture curable hot melt adhesive. Moreover, in the case of the crystalline polyester polyol (A) having a number average molecular weight that is too large, there is a possibility that the coating property of the moisture curable hot melt adhesive may be lowered.

  In the present invention, the number average molecular weight of the polyester polyol and the polyether polyol can be measured using a gel permeation chromatography (GPC) method. For example, a sample solution is prepared by dissolving polyester polyol or polyether polyol in tetrahydrofuran (THF) so as to have a concentration of 1.0% by weight, and the GPC method using the sample solution according to the following measuring apparatus and measurement conditions. Thus, it can be carried out using a refractive index detector with reference to standard polystyrene.

  As a measuring device, for example, a system (all manufactured by Shimadzu Corp.) comprising LC-9A for liquid feeding device, RID-6A for refractive index detector, CTO-6A for column oven, and C-R4A for data analysis device. Can be used. As the GPC column, for example, three GPC-805 (exclusion limit of 4 million) and one GPC-804 (exclusion limit of 400,000) (all manufactured by Shimadzu Corporation) can be connected in this order and used. The measurement conditions are a sample injection volume of 25 μl (liter), an eluent tetrahydrofuran (THF), a liquid feed volume of 1.0 ml / min, and a column temperature of 45 ° C.

  Although content of crystalline polyester polyol (A) in a polyol compound is limited to 15 to 45 weight%, 15 to 35 weight% is preferable and 20 to 30 weight% is more preferable. The moisture curable hot melt adhesive having a content of the crystalline polyester polyol (A) within the above range is excellent in initial adhesive strength and further improved in adhesive strength after moisture curing. In addition, when using multiple types of crystalline polyester polyol (A), let content of crystalline polyester polyol (A) be total content of multiple types of crystalline polyester polyol (A).

(Amorphous polyester polyol (B))
The softening point of the amorphous polyester polyol (B) is limited to 40 ° C. or less. According to the non-crystalline polyester polyol (B) having a softening point within the above range, it is possible to provide a moisture curable hot melt adhesive with improved adhesive strength after moisture curing.

  In the present invention, the softening point of the amorphous polyester polyol is a value measured according to the ring and ball method defined in JIS K6863.

  Preferred examples of the amorphous polyester polyol (B) include those obtained by condensation polymerization of a polycarboxylic acid and a polyol. Examples of the polycarboxylic acid include terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and suberin. Examples include acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid. In addition, as the polyol, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol 1,10-decanediol, diethylene glycol, cyclohexanediol and the like.

  10-150 are preferable, as for the hydroxyl value of an amorphous polyester polyol (B), 10-100 are more preferable, and 20-40 are especially preferable. If the amorphous polyester polyol (B) has a hydroxyl value that is too low, the coatability of the moisture-curable hot melt adhesive may be reduced. Moreover, in the amorphous polyester polyol (B) whose hydroxyl value is too high, there is a possibility that the adhesive strength of the moisture curable hot melt adhesive may be lowered.

  1000-10000 are preferable and, as for the number average molecular weight of an amorphous polyester polyol (B), 1000-5000 are more preferable. If the number average molecular weight is too small, the amorphous polyester polyol (B) may not be able to sufficiently improve the initial adhesive strength of the moisture-curable hot melt adhesive. Moreover, in the amorphous polyester polyol (B) whose number average molecular weight is too large, there is a possibility that the applicability of the moisture curable hot melt adhesive may be lowered.

  The content of the amorphous polyester polyol (B) in the polyol compound is limited to 5 to 40% by weight, preferably 10 to 35% by weight, and more preferably 20 to 35% by weight. The moisture curable hot melt adhesive having a content of the amorphous polyester polyol (B) within the above range is excellent in initial adhesive strength and further improved in adhesive strength after moisture curing. In addition, when using multiple types of non-crystalline polyester polyol (B), let content of non-crystalline polyester polyol (B) be total content of multiple types of non-crystalline polyester polyol (B).

(Amorphous polyester polyol (C))
The softening point of the amorphous polyester polyol (C) is limited to 60 ° C. or higher, but 70 to 110 ° C. is preferable. According to the amorphous polyester polyol (C) having a softening point within the above range, the initial adhesive strength of the moisture-curable hot melt adhesive can be improved.

  Preferred examples of the amorphous polyester polyol (C) include those obtained by condensation polymerization of a polycarboxylic acid and a polyol. Examples of the polycarboxylic acid include terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and suberin. Examples include acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid. In addition, as the polyol, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol 1,10-decanediol, diethylene glycol, cyclohexanediol and the like.

  The number average molecular weight of the amorphous polyester polyol (C) is preferably from 1,000 to 10,000, more preferably from 1,000 to 5,000. If the number average molecular weight is too small, the amorphous polyester polyol (C) may not be able to sufficiently improve the initial adhesive strength of the moisture-curable hot melt adhesive. Moreover, in the amorphous polyester polyol (C) whose number average molecular weight is too large, there is a possibility that the coating property of the moisture curable hot melt adhesive may be lowered.

  The hydroxy value of the amorphous polyester polyol (C) is preferably 10 to 150, more preferably 10 to 100, and particularly preferably 30 to 60. If the amorphous polyester polyol (C) has a hydroxyl value that is too low, the coatability of the moisture-curable hot melt adhesive may be reduced. Moreover, in the amorphous polyester polyol (C) whose hydroxyl value is too high, there is a possibility that the adhesive strength of the moisture curable hot melt adhesive may be lowered.

  Although content of the amorphous polyester polyol (C) in a polyol compound is limited to 5 to 30 weight%, 10 to 30 weight% is preferable and 15 to 30 weight% is more preferable. The moisture curable hot melt adhesive in which the content of the amorphous polyester polyol (C) is within the above range is excellent in initial adhesive strength. In addition, when using multiple types of non-crystalline polyester polyol (C), let content of non-crystalline polyester polyol (C) be the total content of multiple types of non-crystalline polyester polyol (C).

(Polyether polyol (D))
The number average molecular weight of the polyether polyol (D) is limited to 3000 or less, but is preferably 100 to 3000, more preferably 500 to 3000, and particularly preferably 1000 to 3000. According to the polyether polyol (D) having a number average molecular weight within the above range, it is possible to provide a moisture curable hot-melt adhesive having excellent initial adhesive strength and excellent adhesive strength after moisture curing. .

  Examples of the polyether polyol (D) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene polyoxypropylene glycol, and an alkylene oxide adduct of bisphenol A. In polyoxyethylene polyoxypropylene glycol, the arrangement of polyoxyethylene units and polyoxypropylene units may be random or block. The alkylene oxide adduct of bisphenol A can be obtained, for example, by subjecting an active hydrogen of bisphenol A to an alkylene oxide addition reaction. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and isobutylene oxide. When two or more types of alkylene oxide are added to bisphenol A, the arrangement of each alkylene oxide unit may be random or block.

  Among these, as the polyether polyol (D), polypropylene glycol, polyoxyethylene polyoxypropylene glycol, and an alkylene oxide adduct of bisphenol A are preferable. Of the alkylene oxide adducts of bisphenol A, an adduct formed by adding ethylene oxide and / or propylene oxide to bisphenol A is more preferable.

  Although content of polyether polyol (D) in a polyol compound is limited to 5-45 weight%, 5-30 weight% is preferable and 10-20 weight% is more preferable. A moisture-curable hot melt adhesive having a polyether polyol (D) content within the above range is excellent in initial adhesive strength and adhesive strength after moisture curing. In addition, when using multiple types of polyether polyol (D), let content of polyether polyol (D) be total content of multiple types of polyether polyol (D).

  In addition to the above-described crystalline polyester polyol (A), non-crystalline polyester polyol (B), non-crystalline polyester polyol (C), and polyether polyol (D), the polyol compound inhibits the object of the present invention. Other polyols may be included as long as they are not. Examples of other polyols include polyester polyol, polyether polyol, polycaprolactone, polyalkylene polyol, and polycarbonate.

[Polyisocyanate compound]
The moisture curable hot melt adhesive of the present invention contains a urethane prepolymer obtained by reacting a polyol compound and a polyisocyanate compound. The polyisocyanate compound is a polyisocyanate compound having two or more isocyanate groups in one molecule.

  Examples of the polyisocyanate compound include 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4-diphenylmethane diisocyanate (2,4-MDI), 2,2'-diphenylmethane diisocyanate (2,2 ' -MDI), carbodiimide modified diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, carbodiimidized diphenylmethane polyisocyanate, tolylene diisocyanate (TDI, 2,4, 2,6, or mixtures thereof), xylylene diisocyanate (XDI) 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate (HDI), dimer acid diiso Annate, norbornene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), cyclohexane diisocyanate, dicyclohexylmethane Examples thereof include diisocyanate and isophorone diisocyanate. These may be used alone or in combination of two or more.

  Of these, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and carbodiimide-modified diphenylmethane diisocyanate are preferable.

[Urethane prepolymer]
The urethane prepolymer contained in the moisture-curable hot-melt adhesive of the present invention includes the above-described components, that is, a crystalline polyester polyol (A), an amorphous polyester polyol (B), and an amorphous polyester polyol (C). And a polyol compound containing polyether polyol (D) and a polyisocyanate compound are obtained.

  When synthesizing the urethane prepolymer, the molar ratio ([NCO] / [OH]) of the sum of the isocyanate groups (NCO) of the polyisocyanate compound and the sum of the hydroxyl groups (OH) of the polyol compound, It is preferable to set it as 1.5-3. When the molar ratio ([NCO] / [OH]) is less than 1.5, the viscosity of the resulting urethane prepolymer becomes too high, and there is a possibility that the coatability and workability of the moisture curable hot melt adhesive may be reduced. is there. When the molar ratio ([NCO] / [OH]) exceeds 3, the resulting moisture-curable hot melt adhesive contains a large amount of polyisocyanate compound that has not reacted with the polyol compound, and the moisture-curable hot melt adhesive. The moisture-curing hot-melt adhesive may foam when curing.

  As a method for synthesizing a urethane prepolymer, for example, a polyol compound is heated to 80 to 120 ° C. to be in a molten state, dehydrated under reduced pressure, etc., and then a polyisocyanate compound is added to the molten polyol compound in a nitrogen atmosphere. And the method of making a polyol compound and polyisocyanate react is used preferably.

[Other additives]
The moisture curable hot melt adhesive of the present invention may further contain other additives in addition to the urethane prepolymer described above. Other additives include tackifying resins, oils, plasticizers, thermoplastic resins, curing catalysts, stabilizers, fillers, antioxidants, light stabilizers, UV absorbers, polymers with hydrolyzable silyl groups, Coloring agents, flame retardants, fragrances, pigments, dyes and the like can be mentioned.

  Examples of tackifying resins include rosin resins, terpene resins, aliphatic petroleum resins, and aromatic petroleum resins. The ring-and-ball softening point of the tackifying resin is preferably 90 to 150 ° C.

  Examples of the oil include process oil, extender oil, softener, naphthenic oil, paraffinic oil,

  Examples of the plasticizer include phosphoric acid esters such as tributyl phosphate and tricresyl phosphate, phthalic acid esters such as dioctyl phthalate, fatty acid-basic acid esters such as glycerin monooleate, and fatty acid diacids such as dioctyl adipate. Hydrocarbon oils such as basic esters, aliphatic esters such as butyl oleate and methyl acetylricinoleate, trimellitic esters, chlorinated paraffins, alkyldiphenyls, partially hydrogenated terphenyls, process oils, epoxidized soybean oil , Epoxy plasticizers of benzyl epoxy stearate, vinyl polymers obtained by polymerizing vinyl monomers, esters of polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, pentaerythritol ester Etc., and the like.

  Examples of the thermoplastic resin include acrylic polymers, methacrylic polymers, polyvinyl acetate, polystyrene derivatives, polyisobutene, polyolefins, polyalkylene oxides, polyurethanes, polyamides, natural rubber, polybutadiene, polyisoprene, and nitro. Butadiene rubber (NBR), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), hydrogenated nitro Butadiene rubber (hydrogenated NBR), hydrogenated styrene-butadiene-styrene block copolymer (hydrogenated SBS), hydrogenated styrene-isoprene-styrene block copolymer (hydrogenated SIS), and hydrogenated styrene-ethylene-butylene -St Such emission block copolymer (hydrogenated SEBS) and the like.

  The curing catalyst is used to improve the moisture reactivity of the moisture curable hot melt adhesive. As the catalyst, an amine curing catalyst or a tin curing catalyst is used. The amine-based curing catalyst is preferably a morpholine-based compound. Specifically, 2,2′-dimorpholinodiethyl ether, bis (2,6-dimethylmorpholinoethyl) ether, bis (2- (2,6-dimethyl) -4-morpholino) ethyl)-(2- (4-morpholino) ethyl) amine, bis (2- (2,6-dimethyl-4-morpholino) ethyl)-(2- (2,6-diethyl-4-) Morpholino) ethyl) amine, tris (2- (4-morpholino) ethyl) amine, tris (2- (4-morpholino) propyl) amine, tris (2- (4-morpholino) butyl) amine, tris (2- ( 2,6-dimethyl-4-morpholino) ethyl) amine, tris (2- (2,6-diethyl-4-morpholino) ethyl) amine, tris (2- (2-ethyl-4-) And bis (lino) ethyl) amine, tris (2- (2-ethyl-4-morpholino) ethylamine, etc. Examples of tin-based curing catalysts include stannous acetate, dibutyltin dilaurate, dibutyltin dioctate, and dibutyltin diacetate. , Dioctyltin dilaurate, dioctyltin dioctate, dioctyltin diacetate, and stannous dioctanoate.

  The stabilizer is preferably an organic phosphorus compound. Specifically, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tris (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl Examples include diphenyl phosphate, tris (isopropylphenyl) phosphate, cresyl diphenyl phosphate, triphenyl phosphite, triphenyl phosphine, triphenyl phosphine oxide, and aromatic phosphoric acid condensed ester. Among these, organic phosphorus compounds that are solid at room temperature are preferable, and triphenyl phosphate, triphenyl phosphine, triphenyl phosphine oxide, and aromatic phosphoric acid condensed esters are more preferable. According to the organophosphorus compound, the thermal stability of the moisture curable hot melt adhesive can be improved without reducing the curing rate of the moisture curable hot melt adhesive.

  Examples of the filler include, for example, silica, talc, clay, calcium carbonate, magnesium carbonate, anhydrous silicon, hydrous silicon, calcium silicate, titanium dioxide, carbon black, bentonite, organic bentonite, shirasu balloon, glass microballoon, phenol Examples thereof include organic microballoons made of resins and vinylidene chloride resins, and particles made of resins such as PVC and PMMA.

  Examples of the antioxidant include a monophenol antioxidant, a bisphenol antioxidant, and a polyphenol antioxidant.

  As the light stabilizer, for example, a hindered amine light stabilizer is preferably used. Among these, a hindered amine light stabilizer in which the amine moiety is a tertiary amine is more preferable. Specifically, N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidine-4- Yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) decanedioate) Ester, reaction product of 1,1-dimethylethyl hydroperoxide and octane, bis (1,2,2,6,6, -pentamethyl-4-piperidyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidylseba Kate, and Scan etc. (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate and the like.

  Examples of ultraviolet absorbers include benzotriazole ultraviolet absorbers and benzophenone ultraviolet absorbers.

  The polymer having a hydrolyzable silyl group has at least one crosslinkable hydrolyzable silyl group in one molecule. The hydrolyzable silyl group is a group in which the hydrolyzable group is bonded to a silicon atom. Examples of the hydrolyzable group include a hydrogen atom, a halogen atom, an alkoxy group, an acyl oxide group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyl oxide group. It is done.

  As the hydrolyzable silyl group, an alkoxysilyl group in which an alkoxy group is bonded to a silicon atom is preferable because no harmful by-product is formed after the reaction. Examples of the alkoxy group include methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, tert-butoxy group, phenoxy group, and benzyloxy group. Of these, a methoxy group and an ethoxy group are preferable.

  Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group and triphenoxysilyl group; dialkoxysilyl such as dimethoxymethylsilyl group and diethoxymethylsilyl group Groups; monoalkoxysilyl groups such as methoxydimethylsilyl group and ethoxydimethylsilyl group. The polymer having a hydrolyzable silyl group may have one or more of these alkoxysilyl groups.

  Preferable examples of the main chain of the polymer having a hydrolyzable silyl group include polyalkylene oxide, polyether polyol, (meth) acrylic acid ester polymer, polyolefin, and polyester. Examples of the polyalkylene oxide include polyethylene oxide, polypropylene oxide, and polybutylene oxide. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers and block copolymers thereof, and alkylene oxide adducts of bisphenol A. As a monomer which comprises a (meth) acrylic acid ester polymer, the alkyl (meth) acrylate whose carbon number of an alkyl group becomes like this. Preferably it is 1-12, More preferably, it is 2-8. In the present invention, (meth) acrylic acid means both acrylic acid and methacrylic acid. Examples of the polyolefin include homopolymers and copolymers such as ethylene and propylene, and specifically, polyethylene (for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE). ), Metallocene-catalyzed polyethylene, high-density polyethylene (HDPE), etc.), polypropylene (PP), ethylene-α-olefin copolymers (ethylene-propylene copolymers, etc.), and the like. As the polyester, a polyester polyol is preferably exemplified. Specifically, it is obtained by condensing glycols such as ethylene glycol, propylene glycol, neopentyl glycol, and tetramethylene glycol with dicarboxylic acids such as terephthalic acid, isophthalic acid, sebacic acid, succinic acid, phthalic acid, and adipic acid. And polyester polyols that can be used.

[Cosmetic materials]
The moisture curable hot melt adhesive of the present invention described above is suitably used for a cosmetic material. In the decorative material, the moisture-curable hot melt adhesive of the present invention is preferably used for bonding and integrating the base material and the decorative sheet.

  The configuration of the decorative material is not particularly limited, and includes a configuration of a conventionally known decorative material. For example, a cosmetic material in which a base material and a decorative sheet are bonded and integrated with the moisture-curable hot melt adhesive of the present invention can be mentioned.

  The moisture curable hot melt adhesive of the present invention is excellent in solidification speed and can exhibit excellent initial adhesive strength after solidification. Therefore, immediately after bonding the base material and the decorative sheet through the moisture curable hot melt adhesive, the moisture curable hot melt adhesive quickly cools and solidifies so that the base material and the decorative sheet have sufficient adhesive strength. Can be glued. Therefore, even if it is a base material which has complicated shapes, such as a curved surface part, an uneven | corrugated | grooved part, a corner | angular part, and a groove part, it can bond together to a base material, without peeling a decorative sheet along the shape of a base material. Furthermore, the moisture curable hot melt adhesive of the present invention can further improve the adhesive strength after moisture curing, and can firmly bond and integrate the base material and the decorative sheet. Therefore, even when the decorative material is placed in a high-temperature environment, the moisture-curable hot melt adhesive exhibits excellent heat-resistant adhesiveness, and the base material and the decorative sheet are firmly bonded and integrated without peeling. Can be maintained.

  As a method for producing a decorative material, for example, a moisture-curing hot melt adhesive is melted by heating to 70 to 160 ° C., and then applied onto one of a base material or a decorative sheet and applied moisture. A laminate is obtained by laminating the other of the base material or the decorative sheet to the curable hot-melt adhesive, and the moisture-curable hot-melt adhesive is cured by curing the laminated body, whereby the adhesive layer is formed. There is a method of forming a decorative material in which a base material and a decorative sheet are bonded and integrated by an adhesive layer while being formed.

  Examples of the method for applying the heat-cured moisture-curable hot melt adhesive to the substrate or the decorative sheet include a roll coater, a spray coater, a T-die coater, and a knife coater.

  In addition, before curing the laminate, it is preferable to press the substrate, the moisture-curable hot melt adhesive, and the decorative sheet by performing a roll press, a flat press, a belt press or the like on the laminate.

  Base materials used for decorative materials include vinyl chloride resin, vinylidene chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, polyamide resin, polyester resin, polyurethane resin, polyvinyl alcohol resin, ethylene-vinyl acetate copolymer resin , Synthetic resin board made of synthetic resin such as chlorinated polypropylene resin and melamine resin; natural wood, plywood, medium density fiber substrate (medium density fiber board (MDF)), particle board, rigid fiber board, semi-rigid fiber board And wood such as laminated wood; inorganic boards; and metal plates made of metals such as aluminum, iron, and stainless steel. Primer treatment such as plasma treatment, electrodeposition coating treatment such as acrylic resin and melamine acrylic resin, and alumite treatment is performed on the surface of the base material that is to be integrated with the adhesive layer. Also good. In addition to the groove portion, a curved surface portion such as an R portion or an inverted R portion may be formed on the base material.

  Examples of decorative sheets include polyester, nylon, polystyrene, polycarbonate, vinyl chloride, ethylene-vinyl acetate copolymer, synthetic resin sheets containing synthetic resins such as polyvinyl alcohol, polyethylene, and polypropylene, paper, veneer, and metal foil. It is done. The decorativeness of the decorative sheet may be enhanced by applying a color or pattern to the surface.

  The decorative material of the present invention is preferably used as, for example, exterior materials such as flooring, wooden doors and panels, window frames, sills, handrails, skirting boards, edges, kitchens, and closets, interior materials, and furniture.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

  First, the crystalline polyester polyols (A1) to (A4), the amorphous polyester polyols (B1) to (B3), the amorphous polyester polyols (C1) to (C2) used in the examples and comparative examples described below, Detailed description will be given below for each of the polyether polyols (D1) to (D6) and the polyisocyanate.

[Crystalline Polyester Polyol (A)]
・ Crystalline polyester polyol (A1)
Crystalline polyester polyol obtained by condensation polymerization of decamethylene dicarboxylic acid (carbon number 12) and hexanediol (carbon number 6), hydroxyl value 31, number average molecular weight 3,500, product name “Dynacol 7380” manufactured by Evonik Degussa
・ Crystalline polyester polyol (A2)
Crystalline polyester polyol obtained by condensation polymerization of sebacic acid (10 carbon atoms) and hexanediol (6 carbon atoms), hydroxyl value 32, number average molecular weight 3500, manufactured by Toyokuni Oil Products Co., Ltd. “HS 2H-350S”
・ Crystalline polyester polyol (A3)
Crystalline polyester polyol obtained by condensation polymerization of decamethylene dicarboxylic acid (12 carbon atoms) and ethylene glycol (2 carbon atoms), hydroxyl value 31, number average molecular weight 3500
・ Crystalline polyester polyol (A4)
Crystalline polyester polyol obtained by condensation polymerization of adipic acid (6 carbon atoms) and hexanediol (6 carbon atoms), hydroxyl value 25, number average molecular weight 4500, manufactured by Toyokuni Oil Co., Ltd. Trade name “HS 2H-451A”

[Amorphous polyester polyol (B)]
・ Amorphous polyester polyol (B1)
Amorphous polyester polyol obtained by condensation polymerization of isophthalic acid, adipic acid and sebacic acid, ethylene glycol, neopentyl glycol and 1,6-hexanediol, softening point of 30 ° C. or lower, glass transition temperature of −15 ° C., hydroxyl group Value 35, number average molecular weight 3000, product name “HS 2F-305S” manufactured by Toyokuni Oil
・ Amorphous polyester polyol (B2)
Amorphous polyester polyol, softening point 30 ° C. or lower, glass transition temperature −15 ° C., hydroxyl value 28, number average molecular weight 3500, product name “Dynacol 7210” manufactured by Evonik Degussa
・ Amorphous polyester polyol (B3)
Amorphous polyester polyol, softening point 30 ° C. or lower, glass transition temperature −31 ° C., hydroxyl value 32, number average molecular weight 3500, product name “Polyol 2000” manufactured by Toyokuni Oil Co., Ltd.

[Amorphous polyester polyol (C)]
・ Amorphous polyester polyol (C1)
Amorphous polyester polyol, softening point 77 ° C, hydroxyl value 52, number average molecular weight 2500, trade name "HM-204" manufactured by Arakawa Chemical Co., Ltd.
・ Amorphous polyester polyol (C2)
Non-crystalline polyester polyol, softening point 81 ° C., hydroxyl value 32, number average molecular weight 3000, product name “Polyol 1000” manufactured by Toyokuni Oil Co., Ltd.

[Polyether polyol (D)]
・ Polyether polyol (D1)
Propylene oxide adduct of bisphenol A, number average molecular weight 800, product name “BPX55” manufactured by ADEKA
・ Polyether polyol (D2)
Polypropylene glycol, number average molecular weight 700, hydroxyl value 160, manufactured by Asahi Glass Co., Ltd., trade name “Exenol 720”
・ Polyether polyol (D3)
Polypropylene glycol, number average molecular weight 1000, hydroxyl value 112, trade name “Exenol 1020” manufactured by Asahi Glass Co., Ltd.
・ Polyether polyol (D4)
Polypropylene glycol, number average molecular weight 3000, hydroxyl value 35, manufactured by Asahi Glass Co., Ltd., trade name “Excenol 3020”
・ Polyether polyol (D5)
Polypropylene glycol polyol, number average molecular weight 5000, hydroxyl value 28, product name “Preminol 5001” manufactured by Asahi Glass Co., Ltd.
・ Polyether polyol (D6)
Polypropylene glycol polyol, number average molecular weight 10,000, hydroxyl value 11, manufactured by Asahi Glass Co., Ltd. “Preminol 4001”

[Polyisocyanate]
・ 4,4'-diphenylmethane diisocyanate

(Examples 1-7 and Comparative Examples 1-4)
As the polyol compound, crystalline polyester polyols (A1) to (A4), amorphous polyester polyols (B1) to (B3), amorphous polyester polyols (C1) to (C2), polyether polyols (D1) to (D) D6) is put in a 1-liter four-necked flask having stirring blades in the blending amounts shown in Table 1, respectively, and melted by heating to 120 ° C. to obtain a molten mixture, and the pressure is reduced to 1 mmHg or less. The mixture was dehydrated and the temperature of the mixture was cooled to 80 ° C. after purging the flask with nitrogen gas. Next, 4,4′-diphenylmethane diisocyanate was added as a polyisocyanate compound in the flask in the amount shown in Table 1, and stirred for 3 hours in a nitrogen gas atmosphere. Thereby, the polyol compound and the polyisocyanate compound reacted to obtain a moisture-curable hot melt adhesive containing a urethane prepolymer having an isocyanate group at the terminal.

  In Table 1, crystalline polyester polyols (A1) to (A4), amorphous polyester polyols (B1) to (B3), and amorphous polyester polyols (C1) to (C2) with respect to the total weight of the polyol compound. The respective weight ratios (% by weight) of the polyether polyols (D1) to (D6) are listed in the “Polyol compound [% by weight]” column.

(Evaluation)
The adhesiveness of the moisture curable hot melt adhesive was evaluated by the following procedure. The results are shown in Table 1.

(Initial bond strength)
After the moisture curable hot melt adhesive was heated to 120 ° C. and melted, the molten moisture curable hot melt adhesive was applied to one surface of the olefin sheet (thickness 180 μm) with a coating thickness of 40 μm. Then, after superimposing it on a medium density fiber base material (medium density fiber board (MDF)) whose surface temperature was adjusted to 35 ° C. via a moisture-curable hot melt adhesive coated with an olefin sheet, the rubber roll rolled the olefin. A test piece was obtained by pressure-bonding the sheet and the medium density fiber base material.

  Next, the moisture-curable hot melt adhesive was cooled and solidified by leaving the test piece in an environment of 23 ° C. and 55% relative humidity for 1 hour. Thereafter, the olefin sheet was peeled from the medium density fiber base material at a peeling angle of 180 degrees and a peeling speed of 250 mm / min, and the maximum peel strength at this time was measured as “initial peel strength (N / 25 mm)”.

(Adhesive strength after moisture curing)
A test piece was prepared in the same manner as in the above procedure for measuring the initial adhesive strength. Next, the moisture-curable hot melt adhesive was cooled and solidified by leaving the test piece in an environment of 23 ° C. and 55% relative humidity for 1 hour. Thereafter, the test piece was left to stand in an environment of a temperature of 23 ° C. and a relative humidity of 55% for one week to cure the moisture-curable hot melt adhesive. Then, the olefin sheet was peeled from the medium density fiber base material at a peeling angle of 180 degrees and a peeling speed of 250 mm / min, and the maximum peel strength at this time was measured as “normal peel strength (N / 25 mm)”.

(Heat resistant creep resistance)
A test piece (width 1 cm) was prepared in the same manner as in the above procedure for measuring the initial adhesive strength. Next, the moisture-curable hot melt adhesive was cooled and solidified by leaving the test piece in an environment of 23 ° C. and 55% relative humidity for 1 hour. Thereafter, the test piece was left to stand in an environment of a temperature of 23 ° C. and a relative humidity of 55% for one week to cure the moisture-curable hot melt adhesive. Under a temperature environment of 60 ° C., the test piece was placed horizontally so that the olefin sheet was on the lower surface, and then a 2 kg weight was suspended vertically at one end in the length direction of the olefin sheet. After the lapse of 1 hour in this state, the longest length (mm) at which the olefin sheet was peeled from the medium density fiber substrate was measured.

(Bending test)
After the moisture-curing hot melt adhesive is heated to 120 ° C. and melted, the moisture-curing hot melt adhesive in a molten state is applied to one surface of a flat rectangular olefin sheet (thickness 180 μm, width 1 cm). Coating was performed at 40 μm. On the other hand, the surface temperature of the medium density fiber base material (medium density fiber board (MDF)) having a square pillar shape was adjusted to 35 ° C. Next, one half of the olefin sheet (thickness 180 μm) extending from one end edge to the center in the width direction was bonded to one surface of a square columnar medium density fiber substrate via a moisture-curable hot melt adhesive. Thereafter, one half of the olefin sheet was pressure-bonded to one surface of a quadrangular columnar medium density fiber substrate with a rubber roll. Next, the other half part extending from the other end edge to the center in the width direction of the olefin sheet is perpendicular to one half part of the olefin sheet along one ridge angle at the four-side end edge of one surface of the quadrangular columnar medium density fiber substrate. The other half was bonded to the other surface adjacent to one surface of the quadrangular columnar medium density fiber substrate at right angles via a moisture-curable hot melt adhesive. Then, the other half part of the olefin sheet was pressure-bonded to the other surface of the square-columnar medium density fiber base material with a rubber roll, thereby obtaining a laminate. The laminated body is allowed to stand for 1 hour in an environment at a temperature of 23 ° C. and a relative humidity of 55% to cool and solidify the moisture-curable hot melt adhesive. At this time, the olefin sheet peels from the medium density fiber substrate. It was observed whether or not. In Table 1, “◯” and “x” are as follows.
○: The olefin sheet was not peeled off.
X: The olefin sheet peeled off.

Claims (2)

15 to 45% by weight of a crystalline polyester polyol (A) obtained by condensation polymerization of a linear polycarboxylic acid having 8 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms,
Amorphous polyester polyol (B) having a softening point of 40 ° C. or lower, 5 to 40% by weight,
A polyol compound comprising 5 to 30% by weight of an amorphous polyester polyol (C) having a softening point of 60 ° C. or higher, and 5 to 45% by weight of a polyether polyol (D) having a number average molecular weight of 3000 or less; A moisture-curable hot melt adhesive comprising a urethane prepolymer obtained by reacting with a polyisocyanate compound and having an isocyanate group at a terminal.   The moisture-curable hot-melt adhesive according to claim 1, wherein the moisture-curable hot-melt adhesive is used for bonding and integrating the base material and the decorative sheet.