JP2013082919A - Moisture-curable hot-melt adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-curable hot-melt adhesive exhibiting excellent adhesion properties to even a non-porous base material.SOLUTION: The moisture-curable hot-melt adhesive contains: a urethane prepolymer (a) having an isocyanate group at both terminals of one molecular thereof; and a polymer (b) having a hydrolyzable silyl group. It is preferable that the urethane prepolymer (a) is obtained by reacting a polyisocyanate compound with at least one polyol compound selected from the group comprising polyester polyol, polycaprolactone polyol, polyether polyol, polyalkylene polyol and polycarbonate polyol.

Description

  The present invention relates to a moisture curable hot melt adhesive for bonding an adherend to a non-porous substrate.

  Conventionally, hot melt adhesives that cure by reacting with moisture are known. Hot melt adhesives are often used for bonding applications that require high adhesion and durability.

  Various hot melt adhesives have been studied. For example, hot melt adhesives mainly composed of a urethane prepolymer having an isocyanate group at the molecular terminal are used (Patent Document 1 and 2). In such a hot-melt adhesive, a part of the isocyanate group reacts with moisture (water) to become an amine, and the produced amine reacts with another isocyanate group to form a crosslinked structure and is cured.

  The moisture curable hot melt adhesive does not contain a solvent and is solid at room temperature. Therefore, when adhering an adherend to a substrate using such a moisture curable hot melt adhesive, the moisture curable hot melt adhesive is applied to the back surface of the adherend while heated and melted. The substrate and the substrate are bonded to the moisture-curing hot melt adhesive applied while the adhesive is melted or softened, and then the adhesive is cooled and solidified in a short time. Bonded and integrated. Further, the adherend is generally subjected to an easy adhesion treatment such as a corona treatment depending on the application, thereby improving the adhesive strength with the moisture curable hot melt adhesive.

  A wide variety of substrates are used depending on the application. Examples of base materials include inorganic base materials such as aluminum, iron, stainless steel, gypsum board and glass, wood base materials such as wood, MDF (medium density fiber board), particle board, laminated wood, and plywood, ABS, Examples thereof include plastic base materials such as PET and polystyrene.

JP-A-11-320805 JP 2009-242557 A

  However, there is an increasing demand for the adhesion of moisture-curing hot melt adhesives to various substrates. For example, in the case of a wood-based substrate, the anchor effect is expected because most of the wood-based substrates are porous. However, a non-porous substrate made of a metal, a synthetic resin, or the like does not sufficiently exhibit the anchor effect, and the adhesiveness of the moisture curable hot melt adhesive to the non-porous substrate may not be sufficient. Furthermore, in order to improve the corrosion resistance, surface treatment such as electrodeposition coating such as acrylic resin or melamine-acrylic resin or alumite treatment is performed on the surface of the non-porous substrate made of metal such as aluminum. In the non-porous substrate subjected to such a surface treatment, the adhesive strength with the hot melt adhesive is further reduced. Therefore, the non-porous substrate that has been subjected to the surface treatment needs to be further subjected to easy adhesion treatment such as corona discharge treatment and plasma treatment, resulting in an increase in the number of manufacturing steps and a decrease in yield. was there. Further, when the adhesive strength of the moisture curable hot melt adhesive to the base material is low, there is also a problem that the adherend bonded and integrated to the base material peels off after a long time in a high temperature environment.

  Accordingly, an object of the present invention is to provide a moisture curable hot melt adhesive that exhibits excellent adhesion even to a non-porous substrate.

  The moisture-curable hot melt adhesive of the present invention is characterized by containing a urethane prepolymer (a) having an isocyanate group at both molecular ends and a polymer (b) having a hydrolyzable silyl group.

  It is preferable to contain the said polymer (b) 1-50 weight part with respect to 100 weight part of urethane prepolymers (a).

  The moisture curable hot melt adhesive of the present invention is solid at normal temperature, melted by heating, and physically solidified by a decrease in temperature, and bonded by chemically curing with moisture (water). Moisture curable to develop force. Although the mechanism of chemically curing the moisture-curing hot melt adhesive of the present invention is not clear, the following can be considered.

  The moisture-curable hot melt adhesive of the present invention includes, as basic components, a urethane prepolymer (a) having an isocyanate group at both molecular ends and a polymer (b) having a hydrolyzable silyl group. The isocyanate group of this urethane prepolymer (a) is a group having a relatively high reactivity, and reacts with moisture (water) contained in the substrate or air to which the adhesive is applied, thereby producing a urethane prepolymer. A urethane bond is formed between them to increase the molecular weight of the urethane prepolymer. Furthermore, the hydrolyzable silyl group of the polymer (b) is also hydrolyzed by moisture (water) contained in the substrate or air to form a silanol group, and then the polymer (b ) To form a siloxane bond, and the polymer (b) has a high molecular weight. Formation of the siloxane bond from the hydrolyzable silyl group is promoted by the catalytic action of the urethane bond formed earlier. In the moisture curable hot melt adhesive of the present invention, it can be considered that the adhesive strength can be expressed by curing by increasing the molecular weight of the urethane prepolymer (a) and increasing the molecular weight of the polymer (b).

  The moisture curable hot melt adhesive of the present invention is used after the moisture curing by using the urethane prepolymer (a) having an isocyanate group at both molecular terminals and the polymer (b) having a hydrolyzable silyl group in combination. It becomes possible to express excellent adhesive strength. Therefore, according to such a moisture curing type hot melt adhesive, the adherend can be bonded to a non-porous substrate with an excellent adhesive force, and surface treatment such as electrodeposition coating or anodizing treatment. It is not necessary to perform easy adhesion treatment such as corona discharge treatment or plasma treatment on the non-porous substrate subjected to the above.

  In addition, according to the moisture curable hot melt adhesive of the present invention, it is possible to bond a non-porous substrate and an adherend with an excellent adhesive force. This can be maintained even when the ambient temperature where the non-porous substrate and the adherend are integrally bonded by the mold hot melt adhesive becomes high.

  The moisture-curable hot melt adhesive of the present invention is characterized by containing a urethane prepolymer (a) having an isocyanate group at both molecular ends and a polymer (b) having a hydrolyzable silyl group.

[Urethane prepolymer (a)]
The urethane prepolymer (a) used in the moisture curable hot melt adhesive of the present invention is a urethane prepolymer obtained by reacting a polyol compound and a polyisocyanate compound and having isocyanate groups at both ends of the molecular chain. Preferably mentioned. The urethane prepolymer (a) does not have a hydrolyzable silyl group capable of crosslinking in the molecule.

  The polyol compound is a compound having two or more hydroxyl groups in one molecule. Preferred examples of the polyol compound include polyester polyol, polycaprolactone polyol, polyether polyol, polyalkylene polyol, and polycarbonate polyol. These polyol compounds may be used independently and may be used in combination of 2 or more types.

  First, examples of the polyester polyol include a polyester polyol obtained by condensation polymerization of a polyvalent carboxylic acid and a polyol. As polyvalent carboxylic acids, succinic acid, terephthalic acid, isophthalic acid, dodecanedioic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelain And dicarboxylic acids such as acid, sebacic acid, and dodecamethylene dicarboxylic acid. Especially, as polyvalent carboxylic acid, linear dicarboxylic acid is preferable. According to the linear dicarboxylic acid, it is possible to provide a moisture-curable hot melt adhesive that exhibits excellent adhesive strength after moisture curing. 4 or more are preferable and, as for carbon number of linear dicarboxylic acid, 4-12 are more preferable. Moreover, it is particularly preferable that the linear dicarboxylic acid has an even number of carbon atoms. Specific examples of such linear dicarboxylic acids include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. While the linear dicarboxylic acid having 4 to 12 carbon atoms and an even number has high crystallinity, it can improve the adhesive force after moisture curing of a moisture-curable hot melt adhesive using the same, Depending on the type of non-porous substrate, it is possible to reduce the adhesive strength of moisture-curing hot melt adhesive before moisture curing, and the moisture-curing hot melt adhesive before moisture curing can be applied to the interface of the non-porous substrate. Can be easily peeled off. In such a case, if a defect such as misalignment occurs when the adherend is bonded to the non-porous substrate, the adherend is peeled off from the non-porous substrate and reattached, It is also possible to reuse the body or the non-porous substrate, thereby providing a moisture curable hot melt adhesive that can improve the yield in the manufacturing process. Examples of the polyol include propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, and cyclohexanediol. Is mentioned. The polyvalent carboxylic acid and the polyol may be used alone or in combination of two or more. The hydroxyl value of the polyester polyol is preferably 2 to 160 mgKOH / g.

  As the polyester polyol, a polyester polyol obtained by condensation polymerization of a polyvalent carboxylic acid composed only of a linear dicarboxylic acid and a polyol is preferably exemplified. Also, a combination of a polyester polyol formed by condensation polymerization of a polyvalent carboxylic acid consisting of only a linear dicarboxylic acid and a polyol, and a polyester polyol formed by condensation polymerization of a polyvalent carboxylic acid containing an aromatic dicarboxylic acid and a polyol. It is more preferable to use them. Preferred examples of the aromatic dicarboxylic acid include isophthalic acid and terephthalic acid.

  In the polyol compound, the content of the polyester polyol obtained by condensation polymerization of a polyvalent carboxylic acid composed only of a linear dicarboxylic acid and the polyol is preferably at least 10% by weight, more preferably 10 to 100% by weight. -50% by weight is particularly preferred, and 15-45% by weight is most preferred.

  Next, examples of the polycaprolactone polyol include polycaprolactone polyol obtained by ring-opening addition polymerization of a lactone compound to the polyol. As a polyol, the thing similar to the polyol mentioned above in the polyester polyol is mentioned. Examples of the lactone compound include β-propiolactone, pivalolactone, δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, and trimethyl-ε-caprolactone.

  Next, examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers and block copolymers thereof, and polyoxyalkylene-modified products of bisphenol A.

  Examples of the modified polyoxyalkylene of bisphenol A include polyether polyols obtained by adding an alkylene oxide to an active hydrogen moiety such as a hydroxy group of the bisphenol A skeleton. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and isobutylene oxide. It is preferable that one or two or more types of alkylene oxides are modified with 1 to 10 moles of monomer units at both ends of the bisphenol A skeleton.

  Next, examples of the polyalkylene polyol include polybutadiene polyol, hydrogenated polybutadiene polyol, and hydrogenated polyisoprene polyol.

  Examples of the polycarbonate polyol include polyhexamethylene carbonate polyol and polycyclohexane dimethylene carbonate polyol.

  Among the above-mentioned compounds, polyester polyols, polyether polyols, and polycaprolactone polyols are preferably used as the polyol compound. Polyester polyol A obtained by condensation polymerization of sebacic acid and 1,6-hexanediol; adipic acid and terephthalic acid Polyester polyol B obtained by condensation polymerization of acid and 1,6-hexanediol; Polyester polyol C obtained by condensation polymerization of dodecanedioic acid and 1,6-hexanediol; Isophthalic acid, adipic acid, sebacic acid and ethylene Polyester polyol D obtained by condensation polymerization of glycol, neopentyl glycol and 1,6-hexanediol; polyester obtained by condensation polymerization of adipic acid and 1,6-hexanediol Copolymers of polyethylene glycol and polypropylene glycol; polyol E; polypropylene glycol polyoxyalkylene modified product of bisphenol A; and polycaprolactone polyol is more preferably used. According to these polyol compounds, excellent adhesiveness can be imparted to the moisture-curable hot melt adhesive.

  Next, the polyisocyanate compound is a compound having two or more isocyanate groups in one molecule. As the polyisocyanate, 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 diisocyanate, Rubornene 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 polyisocyanate compounds 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. Of the polyisocyanate compounds, diphenylmethane diisocyanate is preferably used because it can impart more excellent adhesiveness to the moisture-curable hot melt adhesive.

  As a method for synthesizing the urethane prepolymer (a), the polyol compound was heated to 80 to 120 ° C. and melted, and then the melt obtained was dehydrated under reduced pressure, and then the melt was subjected to a nitrogen atmosphere. A method of adding a polyisocyanate compound and reacting the polyol compound with the polyisocyanate is preferably used.

  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 1.5-4.0. If the molar ratio ([NCO] / [OH]) is less than 1.5, the viscosity of the urethane prepolymer obtained may be too high. Further, if the molar ratio ([NCO] / [OH]) exceeds 4.0, foaming may occur remarkably during moisture curing.

[Polymer (b)]
The polymer (b) having a hydrolyzable silyl group used in the moisture curable hot melt adhesive of the present invention 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. .

  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. In the alkoxysilyl group, 1 to 3 hydrolyzable groups can be bonded to one silicon atom, but when a plurality of hydrolyzable groups are bonded to one silicon atom, the hydrolyzable group The groups may all be of the same type or a combination of different types. In addition, the number of hydrolyzable groups bonded to one silicon atom is preferably 2 or 3 from the viewpoint of the curability and storage stability of the moisture curable hot melt adhesive. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, an n-butoxy group, a t-butoxy group, a phenoxy group, and a benzyloxy group. preferable.

  Examples of the alkoxysilyl group in which an alkoxy group is bonded to a silicon atom include, for example, trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, triphenoxysilyl group; dimethoxymethylsilyl group, dimethoxy Examples include dialkoxysilyl groups such as ethoxymethylsilyl group; monoalkoxysilyl groups such as methoxydimethylsilyl group and ethoxydimethylsilyl group. The polymer (b) may have one or two or more of these alkoxysilyl groups.

  The method for introducing a hydrolyzable silyl group into the polymer (b) is not particularly limited. For example, (1) a hydrosilane having a hydrolyzable silyl group is allowed to act on a polymer having an unsaturated group modified in the molecule. And (2) a method in which a polymer having an unsaturated group modified in the molecule is reacted with a compound having a mercapto group and a hydrolyzable silyl group.

  Examples of the main chain skeleton of the polymer (b) having a hydrolyzable silyl group include polyalkylene oxide, saturated hydrocarbon polymer, (meth) acrylic acid ester polymer, polyester polyol, polyether polyol, polychloroprene. Obtained by radical polymerization of monomers such as polyisoprene, isoprene or butadiene and acrylonitrile and / or styrene, polybutadiene, isoprene or butadiene, acrylonitrile and styrene, vinyl acetate, acrylonitrile and styrene. By vinyl polymer, graft polymer obtained by polymerizing vinyl monomer in the above polymer, polysulfide polymer, nylon 6 by ring-opening polymerization of ε-caprolactam, polycondensation of hexamethylenediamine and adipic acid. Nylon 6 · 6, nylon 6 · 10 by condensation polymerization of hexamethylenediamine and sebacic acid, nylon 11 by condensation polymerization of ε-aminoundecanoic acid, nylon 12 by ring-opening polymerization of ε-aminolaurolactam, among the above nylons Examples thereof include polyamide polymers such as copolymer nylon having two or more components, polycarbonate polymers produced by condensation polymerization of bisphenol A and carbonyl chloride, diallyl phthalate polymers, and the like.

  Among them, as the main chain skeleton of the polymer (b) having a hydrolyzable silyl group, polyalkylene oxide, saturated hydrocarbon polymer, (meth) acrylic acid ester polymer, polyester polyol, and polyether polyol can be used. preferable. In addition, (meth) acrylic acid means acrylic acid or methacrylic acid.

First, polyalkylene oxide is a heavy chain containing a repeating unit whose main chain is represented by the general formula — (R—O) _n — (wherein R represents an alkylene group having 1 to 14 carbon atoms). Refers to coalescence. R is preferably an alkylene group having 1 to 4 carbon atoms. The main chain skeleton of the polyalkylene oxide may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units. Examples of the polyalkylene oxide include polyethylene oxide, polypropylene oxide, polybutylene oxide, and polytetramethylene oxide.

  Next, the saturated hydrocarbon polymer means a polymer containing no carbon-carbon unsaturated bond. Examples of the saturated hydrocarbon polymer include polymers of olefin monomers such as ethylene, propylene, butene, and isobutylene. Specifically, polyethylene (for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), metallocene catalyzed polyethylene, high density polyethylene (HDPE)), polypropylene (PP), Examples include ethylene-α-olefin copolymers (such as ethylene-propylene copolymers) and amorphous polyα-olefins. The saturated hydrocarbon polymer may be a polymer obtained by polymerizing a diene compound such as butadiene or isoprene and then hydrogenating it.

  Next, as monomers constituting the (meth) acrylic acid ester-based polymer, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate , Isooctyl acrylate, isononyl acrylate, isomyristyl acrylate, stearyl acrylate, isobornyl acrylate, benzyl acrylate, 2-butoxyethyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, hexanediol diacrylate, ethylene Glycol diacrylate, propylene glycol diacrylate, neopentyl glyco Diacrylate, trimethylolpropane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, epoxy acrylate, polyester acrylate, urethane acrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate, 3-hydroxy-3-methylbutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate , 2- [acryloyloxy] ethyl-2 Hydroxyethylphthalic acid, 2- [acryloyloxy] ethyl-2-hydroxypropylphthalic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl Methacrylate, isooctyl methacrylate, isononyl methacrylate, isomyristyl methacrylate, stearyl methacrylate, isobornyl methacrylate, benzyl methacrylate, 2-butoxyethyl methacrylate, 2-phenoxyethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, hexanediol dimethacrylate, Ethylene glycol dimetac Relate, propylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylol, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 6-hydroxyhexyl methacrylate, 3-hydroxy-3-methylbuty Methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, pentaerythritol trimethacrylate, 2- [methacryloyloxy] ethyl-2-hydroxyethylphthalic acid, 2- [methacryloyloxy] ethyl-2-hydroxypropylphthalic acid, etc. Can be mentioned. n-Butyl acrylate and methyl methacrylate are preferred. The (meth) acrylic acid ester monomer may be used alone or in combination of two or more.

  It is also possible to copolymerize other monomers in the (meth) acrylic acid ester polymer. Examples of such monomers include styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and divinylbenzene. Styrene derivatives, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate and other compounds having a vinyl ester group, maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, ( (Meth) acrylonitrile, (meth) acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propylvinylether, n-butylvinylether, isobutylvinylether, tert-butyl Ru vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, ethylene glycol butyl vinyl ether, triethylene glycol methyl vinyl ether, benzoic acid (4-vinyloxy) butyl, ethylene glycol Divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, butane-1,4-diol-divinyl ether, hexane-1,6-diol-divinyl ether, cyclohexane-1,4-dimethanol Divinyl ether, di (4-vinyloxy) butyl isophthalate, glutar Di (4-vinyloxy) butyl acid, di (4-vinyloxy) butyl trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol Examples thereof include compounds having a vinyloxy group such as monovinyl ether, diethylene glycol monovinyl ether, 3-aminopropyl vinyl ether, 2- (N, N-diethylamino) ethyl vinyl ether, urethane vinyl ether, and polyester vinyl ether. These monomers may be used alone or in combination of two or more.

  The (meth) acrylic acid ester polymer is obtained by polymerizing the above-described monomers. The polymerization method is not particularly limited, and a known method can be used. For example, free radical polymerization method, anion polymerization method, cation polymerization method, UV radical polymerization method, living anion polymerization method, living cation polymerization method, living Examples include various polymerization methods such as radical polymerization.

  Next, as the polyester polyol, glycols such as ethylene glycol, propylene glycol, neopentyl glycol, and tetramethylene glycol are condensed with dicarboxylic acids such as terephthalic acid, isophthalic acid, sebacic acid, succinic acid, phthalic acid, and adipic acid. The polyester polyol obtained by polymerizing is mentioned.

  Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers and block copolymers thereof, and polyoxyalkylene-modified products of bisphenol A.

  A commercial item can also be used as a polymer (b) containing the hydrolysable silyl group mentioned above. For example, as a commercially available polyalkylene oxide containing a hydrolyzable silyl group, MS polymer S-203, S-303, Silyl MA-440, Silyl SAT-200, SAT-350 and SAT-400 manufactured by Kaneka Corporation; hydrolysis As a commercially available product of polyether polyol containing a reactive silyl group, Exstar ESS-3620, ESS-2420, ESS2410 and ESS3430 manufactured by Asahi Glass Co., Ltd. As a commercial product of a (meth) acrylic acid ester-based polymer having a hydrolyzable silyl group AROFON US-6100 series manufactured by Toa Gosei Co., Ltd. Commercially available saturated hydrocarbon polymers containing hydrolyzable silyl groups include Best Plast 206, EP2412 and EP2403 manufactured by Evonik Degussa Japan.

  The number average molecular weight Mn of the polymer (b) having a hydrolyzable silyl group is preferably 3,000 to 100,000, more preferably 4,000 to 30,000. If the number average molecular weight of the polymer (b) is less than 3,000, the adhesiveness of the resulting moisture curable hot melt adhesive may not be sufficiently improved. Moreover, when the number average molecular weight of the polymer (b) exceeds 100,000, the melt viscosity of the resulting moisture-curable hot melt adhesive becomes too high, and the coatability may be lowered.

  In the present invention, the number average molecular weight Mn of the polymer (b) having a hydrolyzable silyl group can be measured by a method using gel permeation chromatography (GPC).

  For example, a sample solution is prepared by dissolving a polymer (b) having a hydrolyzable silyl group in tetrahydrofuran (THF) so as to have a concentration of 1.0% by weight, and GPC according to the following conditions is prepared using this sample solution. According to the method, it can be measured using a refractive index detector based on standard polystyrene.

  In the GPC method, a system (all manufactured by Shimadzu Corp.) comprising LC-9A for the liquid feeding device, RID-6A for the refractive index detector, CTO-6A for the column oven, and C-R4A for the data analysis device is used. In addition, GPC columns are used by connecting three GPC-805 (exclusion limit of 4 million) and one GPC-804 (exclusion limit of 400,000) (all manufactured by Shimadzu Corporation) in this order. 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.

  The blending amount of the polymer (b) is preferably 1 to 50 parts by weight and more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the urethane prepolymer (a). If the blending amount of the polymer (b) is too small, the adhesive strength of the moisture curable hot melt adhesive may be reduced. Moreover, when there are too many compounding quantities of a polymer (b), there exists a possibility that the moisture hardening rate and adhesive force of a moisture hardening type hot-melt-adhesive may fall.

  The moisture curable hot melt adhesive of the present invention may further contain a tackifier resin, an oil, a thermoplastic resin, and the like in order to enhance the adhesiveness.

  Examples of tackifying resins include rosin resins, terpene resins, aliphatic petroleum resins, and aromatic petroleum resins. Preferably, those having a ring and ball softening point of 90 to 150 ° C are used.

  The tackifier resin may be used alone or in combination of two or more depending on the compatibility with other components and the type of adherend.

  Further, as the oil, oils that are generally known as process oils, extender oils, softeners and the like as rubber softeners are generally used. Examples include aromatic oils, naphthenic oils other than aromatic oils, and paraffinic oils.

  Examples of the thermoplastic resin include a styrene-conjugated diene block copolymer and an ethylene-vinyl acetate copolymer.

  In addition, the moisture-curable hot melt adhesive of the present invention may contain a tertiary amine-based or tin-based curing catalyst in order to increase moisture reactivity.

  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-) Ruhorino) ethyl) amine, tris (2- (2-ethyl-4-morpholino) ethylamine and the like.

  Examples of the tin-based curing catalyst include stannous acetate, dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, dioctyltin diacetate, and stannous dioctanoate.

  The moisture curable hot melt adhesive of the present invention may contain the above-described curing catalyst. When the moisture curable hot melt adhesive contains a curing catalyst, the content of the curing catalyst in the moisture curable hot melt adhesive is preferably 5% by weight or less, and more preferably 0.01 to 1% by weight.

  In addition, the moisture curable hot melt adhesive of the present invention contains, as other additives, stabilizers, anti-aging agents, wetting agents, thickeners, antifoaming agents, colorants, fillers, softening agents and the like. May be.

  As the stabilizer, various compounds can be added, and among them, organic phosphorus compounds are preferable. Specifically, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tris (2-ethylhexyl) phosphate, tributoxy Examples include ethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, tris (isopropylphenyl) phosphate, cresyl diphenyl phosphate, triphenyl phosphite, triphenyl phosphine, and triphenyl phosphine oxide.

  The R & B softening point of the moisture curable hot melt adhesive of the present invention is preferably 40 ° C or higher, more preferably 50 ° C to 120 ° C. When the R & B softening point is less than 40 ° C., the moisture-curable hot melt adhesive is liquid or viscous at room temperature, so that it is difficult to obtain the initial adhesive strength, and the adherend is bonded to the substrate. The adherend may float or peel off. On the other hand, when the R & B softening point exceeds 120 ° C., the melt viscosity of the hot melt adhesive is increased, and the applicability may be lowered.

  In the present invention, the R & B softening point of the moisture curable hot melt adhesive is a value measured according to JIS K 2207.

  The above-described moisture-curable hot melt adhesive of the present invention is suitably used for bonding an adherend to a substrate.

  Examples of the material constituting the base material include vinyl chloride resin, vinylidene chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, polyamide resin, polyester resin, polyurethane resin, polyvinyl alcohol resin, and ethylene-vinyl acetate copolymer. Synthetic resin such as resin, chlorinated polypropylene resin, melamine resin; natural wood, plywood, MDF (medium density fiber board), particle board, hard fiber board, semi-hard fiber board, laminated wood, etc .; aluminum, iron, A metal such as stainless steel is used.

  The substrate may be either a porous substrate or a non-porous substrate, but the moisture curable hot melt adhesive of the present invention exhibits excellent adhesive strength with conventional moisture curable hot melt adhesives. Excellent adhesion strength can be expressed even for non-porous substrates that are difficult to do. Therefore, as a base material, a non-porous base material is preferable and the non-porous base material which consists of a synthetic resin or a metal is more preferable.

  The adherends 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, chlorinated polypropylene. Examples thereof include a sheet made of a synthetic resin such as a resin, a board made of wood, a board made of impregnation with the synthetic resin, a metal foil such as an aluminum foil, paper, and cloth. These adherends can also be used as a laminate in which two or more kinds are laminated. Moreover, it is preferable to give a color and a pattern to the surface of a to-be-adhered body, and this can improve the decorativeness of the to-be-adhered body surface.

  It is preferable that at least the surface of the adherend facing the substrate is subjected to an easy adhesion treatment for improving the adhesive strength with the moisture curable hot melt adhesive. Examples of the easy adhesion treatment include corona discharge treatment, plasma treatment, ozone gas treatment, flame treatment, pre-heat treatment, and treatment for forming a primer layer. The primer layer includes a binder resin. Examples of the binder resin include polyurethane resins, polyester resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymers, acrylic resins, polyvinyl alcohol resins, polyvinyl acetal resins, Examples thereof include a copolymer of ethylene and vinyl acetate or acrylic acid, a copolymer of ethylene and styrene and / or butadiene, and an epoxy resin. The primer layer may contain rubber such as butadiene rubber and acrylic rubber, or elastomer.

  In order to bond the substrate and the adherend, for example, a moisture curable hot melt adhesive is melted by heating in the range of 60 to 150 ° C., and then roll coater, spray coater, T die coater, knife A method is used in which the substrate is applied onto an adherend using a coater or the like, and the adherend is bonded onto the substrate so that the surface on which the adhesive is applied faces the substrate, and is appropriately pressure-bonded. . Moreover, the method of apply | coating the moisture-curable hot-melt-adhesive heat-melted on the base material similarly to the above, and sticking a to-be-adhered body on the application surface can also be used.

  When using a base material made of a metal such as aluminum, iron or stainless steel, the base material may not be heated in advance before the base material and the adherend are bonded together as described above. It is preferable to heat to 35-60 degreeC.

  As described above, the moisture-curable hot melt adhesive of the present invention is applied to a non-porous substrate that has been subjected to a surface treatment such as electrodeposition coating of synthetic resin or anodizing treatment in order to improve corrosion resistance, decorativeness, etc. On the other hand, it is possible to express an excellent adhesive force without performing an easy adhesion treatment on the non-porous substrate. Therefore, the moisture-curable hot melt adhesive of the present invention is a non-porous substrate that has been subjected to surface treatment such as electrodeposition coating of synthetic resin or alumite treatment, particularly an aluminum non-porous substrate that has been subjected to the surface treatment. It is preferably used for bonding the material and the adherend together.

  Examples of synthetic resins used for electrodeposition coating include acrylic resins, melamine resins, melamine-acrylic resins, urethane resins, and epoxy resins. Moreover, as a melamine-acrylic resin, the resin etc. which the melamine resin bridge | crosslinked between the principal chains which consist of acrylic resins are mentioned. A synthetic resin may be used individually by 1 type, and may use 2 or more types together.

  Furthermore, since the moisture-curable hot melt adhesive has low adhesion before moisture curing depending on the type of the non-porous substrate, it can be easily peeled off from the interface of the non-porous substrate. In such a case, if a defect such as misalignment occurs when the adherend is bonded to the non-porous substrate, the adherend is peeled off from the non-porous substrate and reattached, It is also possible to reuse the body or the non-porous substrate, thereby improving the yield in the manufacturing process. As the non-porous substrate having low adhesion of the moisture-curable hot melt adhesive before moisture curing, a non-porous substrate subjected to electrodeposition coating of a synthetic resin such as melamine-acrylic resin is used. Can be mentioned.

  The base material on which the adherend is bonded by the moisture-curable hot melt adhesive of the present invention can be used for stair step plates, door frames, window frames, sills, handrails, indoor panels, solar panels, and the like. .

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to a following example.

[Urethane prepolymer (a1)]
Polyester obtained by condensation polymerization of 100 parts by weight of polyester polyol A (hydroxyl value: 30) obtained by condensation polymerization of sebacic acid and 1,6-hexanediol, and adipic acid, terephthalic acid and 1,6-hexanediol 200 parts by weight of polyol B (hydroxyl value: 25) and 30 parts by weight of polycaprolactone polyol (manufactured by Solvay, trade name: CAPA6500) were heated and melted at 100 ° C., depressurized to 133 Pa or less for 1 hour and dehydrated. . By adding 50 parts by weight of diphenylmethane diisocyanate to the dehydrated product thus obtained and reacting for 3 hours under a nitrogen atmosphere, a urethane prepolymer having isocyanate groups that are solid at room temperature (20 ° C.) at both molecular ends ( a1) was obtained.

[Urethane prepolymer (a2)]
Polyester polyol C (hydroxyl value: 30) 220 parts by weight obtained by condensation polymerization of dodecanedioic acid and 1,6-hexanediol, condensation polymerization of adipic acid, terephthalic acid and 1,6-hexanediol Polyester polyol B (hydroxyl value: 25), 300 parts by weight of polyester polyol B (hydroxyl value: 25), and isopolyphthalic acid, adipic acid and sebacic acid, and ethylene glycol, neopentyl glycol and 1,6-hexanediol are subjected to condensation polymerization. 35) 220 parts by weight were heated and melted at 100 ° C., and dehydrated under reduced pressure to 133 Pa or less over 1 hour. By adding 100 parts by weight of diphenylmethane diisocyanate to the dehydrated product obtained in this manner and reacting for 3 hours, a urethane prepolymer having isocyanate groups that are solid at room temperature (20 ° C.) at both molecular ends ( a2) was obtained.

[Urethane prepolymer (a3)]
100 parts by weight of polyester polyol C (hydroxyl value: 30) obtained by condensation polymerization of dodecanedioic acid and 1,6-hexanediol, and condensation polymerization of adipic acid, terephthalic acid and 1,6-hexanediol Polyester polyol B (hydroxyl value: 25), 200 parts by weight of polyester polyol B (hydroxyl value: 25), and condensation polymerization of isophthalic acid, adipic acid and sebacic acid with ethylene glycol, neopentyl glycol and 1,6-hexanediol. 35) 50 parts by weight of polypropylene glycol (hydroxyl value: 36, manufactured by Asahi Glass Co., Ltd., Exenol 3020) as polyether polyol A is heated and melted at 100 ° C., depressurized to 133 Pa or less over 1 hour, and dehydrated. did. By adding 50 parts by weight of diphenylmethane diisocyanate to the dehydrated product thus obtained and reacting for 3 hours under a nitrogen atmosphere, a urethane prepolymer having isocyanate groups that are solid at room temperature (20 ° C.) at both molecular ends ( a3) was obtained.

[Urethane prepolymer (a4)]
80 parts by weight of polyester polyol C (hydroxyl value: 30) obtained by condensation polymerization of dodecanedioic acid and 1,6-hexanediol, and polyester polyol E obtained by condensation polymerization of adipic acid and 1,6-hexanediol (Hydroxyl value: 25) 20 parts by weight, 200 parts by weight of polyester polyol B (hydroxyl value: 25) obtained by condensation polymerization of adipic acid and terephthalic acid and 1,6-hexanediol, and polyester polyol F (Evonik Degussa) DYNACOL 7210) 60 parts by weight and 40 parts by weight of bisphenol A polypropylene glycol modification (ADEKA BPX-55) as polyether polyol B were heated and melted at 100 ° C. and taken to 133 Pa or less for 1 hour. And dehydrated. By adding 60 parts by weight of diphenylmethane diisocyanate to the dehydrated product thus obtained and reacting for 3 hours under a nitrogen atmosphere, a urethane prepolymer having isocyanate groups that are solid at normal temperature (20 ° C.) at both molecular ends ( a4) was obtained.

[Urethane prepolymer (a5)]
100 parts by weight of polyester polyol C (hydroxyl value: 30) obtained by condensation polymerization of dodecanedioic acid and 1,6-hexanediol, and condensation polymerization of adipic acid, terephthalic acid and 1,6-hexanediol 150 parts by weight of polyester polyol B (hydroxyl value: 25), 50 parts by weight of polyester polyol G (byron 550 manufactured by Toyobo Co., Ltd.), isophthalic acid, adipic acid and sebacic acid, ethylene glycol, neopentyl glycol and 1,6-hexane 50 parts by weight of polyester polyol D (hydroxyl value: 35) obtained by condensation polymerization of diol and 50 parts by weight of polyester polyol H (HS 2F-237P manufactured by Toyokuni Seiyaku Co., Ltd.) are heated and melted at 100 ° C., and 133 Pa or less. And dehydrated under reduced pressure over 1 hour. By adding 50 parts by weight of diphenylmethane diisocyanate to the dehydrated product thus obtained and reacting for 3 hours under a nitrogen atmosphere, a urethane prepolymer having isocyanate groups that are solid at room temperature (20 ° C.) at both molecular ends ( a5) was obtained.

[Polymer having hydrolyzable silyl group (b1)]
As the polymer (b1) having a hydrolyzable silyl group, a polyalkylene oxide having a hydrolyzable silyl group (trade name: MS polymer S303, number average molecular weight Mn 8,000, manufactured by Kaneka Corporation) was prepared.

[Polymer having hydrolyzable silyl group (b2)]
As the polymer (b2) having a hydrolyzable silyl group, a polyether polyol having a hydrolyzable silyl group (trade name: Exester ESS 3430, number average molecular weight Mn 17,000, manufactured by Asahi Glass) was prepared.

[Polymer having hydrolyzable silyl group (b3)]
As the polymer (b3) having a hydrolyzable silyl group, an acrylic ester polymer having a hydrolyzable silyl group (trade name: ARUFON US-6110, manufactured by Toagosei Co., Ltd., number average molecular weight 3,200) was prepared.

[Polymer having hydrolyzable silyl group (b4)]
As a polymer (b4) having a hydrolyzable silyl group, a saturated hydrocarbon polymer having a hydrolyzable silyl group (trade name: Best Plast 206, number average molecular weight Mn 10,600, manufactured by Evonik Degussa) was prepared.

[Polymer having hydrolyzable silyl group (b5)]
As the polymer (b5) having a hydrolyzable silyl group, an acrylic ester polymer having a hydrolyzable silyl group (trade name: Silyl MA440 manufactured by Kaneka Corporation) was prepared.

[Examples 1 to 11 and Comparative Examples 1 to 5]
To the urethane prepolymers (a1) to (a5), the polymers (b1) to (b5) having the hydrolyzable silyl group are added so as to have the blending amounts shown in Table 1, respectively, and are added in a nitrogen atmosphere. The mixture was melt-mixed for 30 minutes while being heated to 100 ° C. to obtain a solid moisture-curable hot melt adhesive at room temperature (20 ° C.).

[Evaluation]
A peel strength test and a heat resistance test were performed on the moisture-curable hot melt adhesives obtained in Examples 1 to 11 and Comparative Examples 1 to 5. The results are shown in Table 1.

[Peel strength test (cured for 72 hours)]
The moisture-curable hot melt adhesive was heated and melted at 120 ° C. with a gear pump applicator, and applied to an olefin sheet (thickness: 0.15 μm) using a slit coater so that the film thickness after application was 50 μm. In the gear pump applicator, the applicator temperature was set to 100 ° C., the hose temperature was set to 110 ° C., and the slit coater temperature was set to 120 ° C.

  Next, immediately after applying the moisture curable hot melt adhesive, an olefin sheet coated with the moisture curable hot melt adhesive and a non-coated melamine-acrylic resin that has been heated to 40 ° C. and electrodeposited. The porous aluminum substrate (1) is overlapped with the surface of the olefin sheet coated with the moisture-curable hot melt adhesive so that the one surface of the non-porous aluminum substrate (1) faces the olefin sheet. A test piece (25 mm in width and 200 mm in length) is obtained by laminating a silicon rubber roll on the sheet and bonding the olefin sheet and the non-porous aluminum substrate (1) through a moisture-curable hot melt adhesive. Was made.

  After the test piece was cured for 72 hours in an atmosphere at a temperature of 20 ° C. and a relative humidity of 60%, the olefin sheet was 200 mm / min in the 180 ° direction from one end to the other end in the length direction from the test piece. Peeling was performed at a peeling speed, and the peel strength (N / 25 mm) at this time was measured by an autograph.

  Furthermore, instead of the non-porous aluminum substrate (1) electrodeposited with melamine-acrylic resin, a non-porous aluminum substrate (1) that has been electrodeposited with melamine-acrylic resin and further subjected to plasma treatment ( 2) Other than using a non-porous aluminum substrate (3) that has been anodized, a non-porous aluminum substrate (4) electrodeposited with a transparent acrylic resin, or a non-porous ABS resin substrate In the same manner as described above, a test piece was prepared and the peel strength was measured.

[Peel strength test (1 hour curing)]
Using the non-porous aluminum base material (1) electrodeposited with the moisture-curable hot melt adhesive and the melamine-acrylic resin of Example 4, the peel strength test (72-hour curing) was performed in the same manner as described above. A test piece was prepared.

  After the test piece was cured for 1 hour in an atmosphere at a temperature of 20 ° C. and a relative humidity of 60%, the olefin sheet was 200 mm / min in the 180 ° direction from one end to the other end of the length direction from the test piece. Peeling was performed at a peeling speed, and the peel strength (N / 25 mm) at this time was measured by an autograph. When the test piece and the olefin sheet were peeled, all of the moisture-curable hot melt adhesive layer was interfacial broken. The lower the adhesive strength of the moisture curable hot melt adhesive layer, the more the interface breaks.

[Heat resistance test]
The moisture-curable hot melt adhesive was heated and melted at 120 ° C. with a gear pump applicator, and applied to an olefin sheet (thickness: 0.15 μm) using a slit coater so that the film thickness after application was 50 μm. In the gear pump applicator, the applicator temperature was set to 100 ° C., the hose temperature was set to 110 ° C., and the slit coater temperature was set to 120 ° C.

  Next, immediately after applying the moisture curable hot melt adhesive, an olefin sheet coated with the moisture curable hot melt adhesive and a non-coated melamine-acrylic resin that has been heated to 40 ° C. and electrodeposited. The porous aluminum substrate (1) is overlapped with the surface of the olefin sheet coated with the moisture-curable hot melt adhesive so that the one surface of the non-porous aluminum substrate (1) faces the olefin sheet. A test piece (25 mm in width and 200 mm in length) is obtained by laminating a silicon rubber roll on the sheet and bonding the olefin sheet and the non-porous aluminum substrate (1) through a moisture-curable hot melt adhesive. Was made.

  After the test piece was cured for 72 hours in an atmosphere at a temperature of 20 ° C. and a relative humidity of 60%, both ends of the test piece were fixed horizontally so that the olefin sheet was on the lower side, and 500 g / 25 mm was attached to one end of the olefin sheet. After being left to stand in a 100 ° C. atmosphere for 24 hours in a state where the load was suspended in the 90 ° direction, the width (mm) at which the olefin sheet was peeled off from the substrate was measured.

  Furthermore, instead of the non-porous aluminum substrate (1) electrodeposited with melamine-acrylic resin, a non-porous aluminum substrate (1) that has been electrodeposited with melamine-acrylic resin and further subjected to plasma treatment ( 2) Other than using a non-porous aluminum substrate (3) that has been anodized, a non-porous aluminum substrate (4) electrodeposited with a transparent acrylic resin, or a non-porous ABS resin substrate In the same manner as described above, a test piece was prepared and the peel strength was measured.

  In the heat resistance test using a non-porous ABS resin substrate, both ends of the test piece are fixed horizontally, and a load of 500 g / 25 mm is suspended from one end of the olefin sheet in a 90 ° direction for 24 hours. In addition, the temperature of the atmosphere was set to 60 ° C.

Claims (4)

  A moisture-curable hot melt adhesive comprising a urethane prepolymer (a) having an isocyanate group at both molecular ends and a polymer (b) having a hydrolyzable silyl group.   The urethane prepolymer (a) is obtained by reacting at least one polyol compound selected from the group consisting of polyester polyol, polycaprolactone polyol, polyether polyol, polyalkylene polyol, and polycarbonate polyol with a polyisocyanate compound. The moisture-curable hot-melt adhesive according to claim 1, wherein the adhesive is a moisture-curable hot-melt adhesive.   The main chain skeleton of the polymer (b) having a hydrolyzable silyl group contains a polyalkylene oxide, a saturated hydrocarbon polymer, a (meth) acrylate polymer, a polyester polyol, or a polyether polyol. The moisture curable hot melt adhesive according to claim 1 or 2.   The moisture-curable hot melt adhesive according to any one of claims 1 to 3, wherein the polymer (b) is contained in an amount of 1 to 50 parts by weight based on 100 parts by weight of the urethane prepolymer (a).