JP2018177937A - Moisture curing type hot melt adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture curing type hot melt adhesive excellent in ordinary adhesive strength and heat creep resistance and excellent in initial adhesion (initial setability) of urethane foam under high temperature (40 ° C.).
SOLUTION: The moisture-curable hot melt adhesive of the present invention is a polyester which is a condensation polymer of a linear polycarboxylic acid having 6 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms. A polyol, a polyether polyol, an acrylic copolymer having a glass transition temperature of 50 to 90 ° C., and a reaction product of a raw material composition containing a tackifier and a polyisocyanate compound, and containing an isocyanate group at an end Containing 10 to 30% by mass of the polyester polyol, 30 to 50% by mass of the polyether polyol, 10 to 20% by mass of the acrylic copolymer, and 5 to 15% by mass of the tackifier. It features.
[Selected figure] None

Description

  The present invention relates to a moisture curable hot melt adhesive.

  Conventionally, cushioning properties and weight reduction have been provided by bonding a cushioning material such as urethane foam to a floor plate material using an adhesive.

  As an adhesive used for adhesion of a floor board and a urethane foam, a water-based emulsion adhesive and a moisture-curable hot melt adhesive are known. Among them, a moisture curing type hot melt adhesive is often used because it can be a measure for improving productivity because the solidification thereof is fast.

  As the moisture curing type hot melt adhesive, for example, a hot melt type adhesive containing a urethane prepolymer having an isocyanate group at a molecular end as a main component is used (for example, Patent Document 1). Such a moisture-curable hot-melt adhesive is applied to a substrate in a heat-melted state and then solidified by cooling to develop an initial adhesive strength. Thereafter, 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 air and the substrate to cause the urethane prepolymer to have a crosslinked structure. The moisture-curable hot melt adhesive cures to further improve the adhesive strength.

JP 2001-262113 A

  However, although the above-mentioned moisture curing type hot melt adhesive can express excellent initial adhesive strength, by the time when the moisture curing type hot melt adhesive coated by the ambient temperature etc. cools and solidifies and develops initial adhesive strength. It takes time, and there is a problem that the urethane foam may partially exfoliate or float before developing the initial adhesive strength. Especially in summer, the temperature is high, and it takes a long time for the moisture-curable hot melt adhesive to cool and solidify to develop the initial adhesive strength, and the urethane foam may easily be partially peeled off or float. Become.

  Therefore, the object of the present invention is to provide a basic performance required for a moisture-curable hot melt adhesive, even at high temperature (40 ° C.) immediately after application of the adhesive while having high levels of normal adhesive strength and heat creep resistance. It is an object of the present invention to provide a moisture-curable hot melt adhesive capable of developing excellent initial adhesion (initial setability).

  The moisture-curable hot melt adhesive of the present invention is a polyester polyol or polyether which is a condensation polymer of a linear polycarboxylic acid having 6 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms. A polyol, an acrylic copolymer having a glass transition temperature of 50 to 90 ° C., and a reaction product of a raw material composition containing a tackifier and a polyisocyanate compound, and containing an isocyanate group at the terminal, When the total amount of the polyester polyol, the polyether polyol, the acrylic copolymer, the tackifier and the polyisocyanate compound is 100% by mass, 10 to 30% by mass of the polyester polyol and 30 to 50 of the polyetherpolyol Mass%, 10 to 20 mass% of the above-mentioned acrylic copolymer, and the above-mentioned tackifier 5 to 1 Characterized in that it comprises a mass%.

  The moisture-curable hot melt adhesive is characterized in that the polyester polyol is a polyester polyol.

  The moisture-curable hot melt adhesive is characterized in that the melt viscosity at 120 ° C. is 20000 mPa · s or less.

  The moisture-curable hot melt adhesive of the present invention is a basic performance required for a moisture-curable hot melt adhesive, while having high levels of normal adhesive strength and heat creep resistance at high temperatures (40 ° C.) It is excellent in the initial adhesiveness (initial settability) of urethane foam.

  The moisture-curable hot melt adhesive of the present invention is a polyester polyol or polyether which is a condensation polymer of a linear polycarboxylic acid having 6 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms. It is a reactant of a polyol, an acrylic copolymer having a glass transition temperature of 50 to 90 ° C., and a raw material composition containing a tackifier and a polyisocyanate compound, and has an isocyanate group at the end.

(Polyester polyol)
The raw material composition contains a polyester polyol. The polyester polyol is a condensation polymer of a linear polycarboxylic acid having 6 to 12 carbon atoms and a linear polyol having 2 to 6 carbon atoms.

  The moisture curable hot melt adhesive contains a polyester polyol. By using a polyester polyol, expression of excellent initial adhesive strength of the moisture-curable hot melt adhesive is achieved. The polyester polyol may be crystalline or non-crystalline, but a polyester polyol having a crystallinity (crystalline polyester polyol) is preferred because the normal adhesive strength of the moisture-curable hot melt adhesive is improved. .

  Whether or not the polyester polyol is crystalline is judged based on the following criteria. In the present invention, the crystalline polyester polyol means that the heat absorption of the melting curve measured at a temperature rising rate of 10 ° C./min in the measurement of differential scanning calorimetry (DSC) defined in JIS K 7121 is 3 cal / g (12 It means a polyester polyol which is not less than .558 J / g). With the non-crystalline polyester polyol, the endotherm of the melting curve measured at a temperature rising rate of 10 ° C./min in the measurement of differential scanning calorimetry (DSC) defined in JIS K7121 is 3 cal / g (12.558 J / m g) means polyester polyols which are less than.

  As a linear polycarboxylic acid having 6 to 12 carbon atoms, a linear aliphatic dicarboxylic acid having 6 to 12 carbon atoms is preferably mentioned. Specifically, adipic acid (6 carbon atoms), sebacine Examples include acids (carbon number 10) and dodecanedioic acid (carbon number 12).

  As a C2-C6 linear polyol, C2-C6 linear alkylene glycol is mentioned preferably. Specifically, ethylene glycol (carbon number 2), butanediol (carbon number 4), and hexanediol (carbon number 6) can be mentioned.

  The polyester polyol is excellent in the initial adhesive strength of the moisture-curable hot melt adhesive, and thus has a linear dicarboxylic acid having a carboxy group at both ends and a carbon number of 12, and a hydroxyl group at both ends. And a linear polyol having 6 carbon atoms is preferable, and a condensation polymer of dodecanedioic acid (1,10-decanedicarboxylic acid) and 1,6-hexanediol is preferably included. .

  The number average molecular weight of the polyester polyol is 400 to 10,000, preferably 1,000 to 5,000, and more preferably 2,000 to 4,000. When the number average molecular weight of the polyester polyol is in the above range, the molecular chain length between cross-linking points in the urethane prepolymer becomes an appropriate length, and the moisture-curable hot melt adhesive has excellent initial adhesion (initial settability). Have.

  In addition, the number average molecular weight of polyester polyol, polyether polyol, and an acryl-type copolymer says the value measured in the following way. The number average molecular weight can be measured using gel permeation chromatography (GPC). For example, a sample solution is prepared by dissolving a polymer to be measured in tetrahydrofuran (THF) so as to have a concentration of 1.0% by mass, and using this sample solution, a GPC method based on the following measuring device and measuring conditions Thus, it can be performed using a refractive index detector based on standard polystyrene.

  As a measurement device, for example, a system (a product made by Shimadzu Corp.) in which the liquid delivery device is LC-9A, the refractive index detector is RID-6A, the column oven is CTO-6A, and the data analysis device is C-R4A It can be used. As the GPC column, for example, three GPC-805s (exclusion limit 4,000,000) and one GPC-804 (exclusion limit 400,000) (all manufactured by Shimadzu Corporation) can be connected in this order and used. The measurement conditions are: sample injection volume 25 μL (liter), eluent tetrahydrofuran (THF), flow volume 1.0 mL / min, column temperature 45 ° C.

  The content of polyester polyol in the raw material composition is 10 to 30% by mass, when the total amount of polyester polyol, polyether polyol, acrylic copolymer, tackifier and polyisocyanate compound is 100% by mass. And 15 to 25% by mass are preferable. When the content of the polyester polyol is 10% by mass or more, the moisture-curable hot melt adhesive is excellent in initial adhesive strength. When the content of the polyester polyol is 30% by mass or less, the open time of the moisture-curable hot melt adhesive becomes long, the high adhesive strength is maintained, and the heat creep resistance is improved.

(Polyether polyol)
The raw material composition contains a polyether polyol. The polyether polyol is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene polyoxypropylene glycol, and an alkylene oxide adduct of bisphenol A represented by the structural formula 1 It can be mentioned. As a polyether polyol, polypropylene glycol, polyoxyethylene polyoxypropylene glycol, and the alkylene oxide adduct of bisphenol A are preferable, and polypropylene glycol is more preferable. Among the alkylene oxide adducts of bisphenol A, an adduct formed by adding ethylene oxide and / or propylene oxide to bisphenol A is more preferable. In polyoxyethylene polyoxypropylene glycol, the arrangement of the polyoxyethylene unit and the polyoxypropylene unit may be random or block. The alkylene oxide adduct of bisphenol A is obtained, for example, by subjecting the 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 alkylene oxides are added to bisphenol A, the arrangement of each alkylene oxide unit may be random or block.

  It is preferable that the polyether polyol contained in the raw material composition does not contain a hydrolyzable silyl group. The hydrolyzable silyl group is a group formed by bonding 1 to 3 hydrolyzable groups to a silicon atom.

  The hydrolyzable group of the hydrolyzable silyl group is not particularly limited, and examples thereof include a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an aminooxy group, a mercapto group and an alkenyloxy group.

式中、ｎ及びｍは、正の整数である。

In the formula, n and m are positive integers.

  The number average molecular weight of the polyether polyol is 400 to 10,000, preferably 700 to 5,000, and more preferably 1,500 to 2,500. When the number average molecular weight of the polyether polyol is within the above range, the molecular length between cross-linking points in the urethane prepolymer becomes an appropriate length, and the moisture-curable hot melt adhesive has excellent initial adhesion (initial setability) Have.

  The content of the polyether polyol in the raw material composition is 30 to 50 mass% when the total amount of the polyester polyol, the polyether polyol, the acrylic copolymer, the tackifier and the polyisocyanate compound is 100 mass%. 35-45 mass% is preferable. When the content of the polyether polyol is 30% by mass or more, the melt viscosity of the moisture-curable hot melt adhesive is lowered, the workability is improved, and the normal adhesion is improved. When the content of the moisture-curable hot melt adhesive is 50% by mass or less, the moisture-curable hot melt adhesive has excellent initial adhesion (initial settability).

  The raw material composition may contain a polyol other than the above polyester polyol and the above polyether polyol, as long as the physical properties of the moisture curable hot melt adhesive are not impaired. Examples of such polyols include polyalkylene polyols and polycarbonates.

(Acrylic copolymer)
The acrylic copolymer is a copolymer of (meth) acrylic acid and an acrylic monomer. In the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid. The acrylic copolymer may be used alone or in combination of two or more.

  The acrylic monomer is not particularly limited as long as it is copolymerizable with (meth) acrylic acid, and examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate and n-butyl Meta) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n- And alkyl (meth) acrylates such as nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate and lauryl (meth) methacrylate. The acrylic monomers may be used alone or in combination of two or more. In the present invention, (meth) acrylate means acrylate or methacrylate.

  The acrylic copolymer may be, for example, Evonik Japan Co., Ltd. under the trade names "Dynacoal AC1630", "Dynacole AC1920", "Dynacole AC4830" and "Dynacole AC1750", and Mitsubishi Rayon Co. with the trade name "Dianal BR-". 113 and Dianal BR-122.

  60000 or more is preferable and, as for the number average molecular weight of an acryl-type copolymer, 120,000 or more is more preferable. When the number average molecular weight of the acrylic copolymer is 60000 or more, the molecular weight of the acrylic copolymer is large, so the intermolecular cohesion is large, and the moisture-curable hot melt adhesive has excellent initial adhesive strength. The number average molecular weight of the acrylic copolymer is preferably at most 200,000, and more preferably at most 150,000. It is preferable that the number average molecular weight of the acrylic copolymer is 200,000 or less, since a remarkable increase in viscosity is prevented and the workability is improved.

  The glass transition temperature of the acrylic copolymer is 50 to 90 ° C., preferably 60 to 80 ° C. When the glass transition temperature of the acrylic copolymer is within the above range, the time from melting to setting of the moisture-curable hot melt adhesive becomes appropriate, and the moisture-curable hot melt adhesive has excellent initial adhesive strength. Have.

  The glass transition temperature of the acrylic copolymer is measured by DSC according to JIS K7121, and after heating and cooling at a rate of 10 ° C./min, in a second run under a rate condition of 10 ° C./min Let it be the temperature at the midpoint of the step of the measured DSC curve.

  The content of the acrylic copolymer in the raw material composition is 10 to 20% by mass, when the total amount of the polyester polyol, polyether polyol, acrylic copolymer, tackifier and polyisocyanate compound is 100% by mass. 12 to 18% by mass is preferable. When the content of the acrylic copolymer is 10% by mass or more, the moisture-curable hot melt adhesive has excellent initial adhesive strength. When the content of the acrylic copolymer is 20% by mass or less, the melt viscosity of the moisture-curable hot melt adhesive is lowered, and the workability and the normal adhesive strength are improved.

(Tackifier)
The raw material composition contains a tackifier. Examples of tackifiers include rosin resins, terpene resins, aliphatic petroleum resins, and aromatic petroleum resins. The ring and ball softening point of the tackifier is preferably 90 to 150 ° C., and more preferably 95 to 109 ° C., because adhesion strength in a normal state is improved. Ring and ball softening point refers to the temperature measured in accordance with JAI-7-1999 (Japan Adhesive Industry Association Standard). The tackifier may be used alone or in combination of two or more.

  The content of the tackifier in the raw material composition is 5 to 15% by mass, when the total amount of the polyester polyol, the polyether polyol, the acrylic copolymer, the tackifier and the polyisocyanate compound is 100% by mass. And 7 to 13% by mass are preferable. When the content of the tackifier is 5% by mass or more, the open time of the moisture-curable hot melt adhesive becomes long, and the normal adhesive strength is improved. When the content of the tackifier is 15% by mass or less, the moisture-curable hot melt adhesive has excellent initial adhesion (initial settability).

(Polyisocyanate compound)
The polyisocyanate compound refers to a compound having two or more isocyanate groups in one molecule.

  Examples of polyisocyanate compounds include 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4-diphenylmethane diisocyanate (2,4-MDI), and 2,2′-diphenylmethane diisocyanate (2,2 ′ -MDI), carbodiimide-modified diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, carbodiimidated diphenylmethane polyisocyanate, tolylene diisocyanate (TDI, 2, 4 or 2, 6 or mixture thereof), xylylene diisocyanate (XDI) 1,5-Naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate (HDI), dimer acid diisocyanate , Norbornene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), cyclohexane diisocyanate, dicyclohexyl Methane diisocyanate, isophorone diisocyanate and the like can be mentioned. The polyisocyanate compound may be used alone or in combination of two or more.

  As the polyisocyanate compound, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and carbodiimide-modified diphenylmethane diisocyanate are preferable, and 4,4'-diphenylmethane diisocyanate is more preferable.

(Urethane prepolymer)
The moisture-curable hot melt adhesive contains a urethane prepolymer which is a reaction product of a raw material composition and a polyisocyanate compound and which has an isocyanate group at the end.

  Specifically, the urethane prepolymer is obtained by reacting a raw material composition containing polyester polyol, polyether polyol, acrylic copolymer and tackifying resin with a polyisocyanate compound.

  The ratio of the total number of moles of isocyanate groups (-NCO) to the total number of moles of hydroxyl groups (-OH) (total number of moles of isocyanate groups / total number of moles of hydroxyl groups) in the raw material composition and the polyisocyanate compound in total is 1 5 to 3 is preferable, and 1.8 to 2.2 is more preferable. Moisture curing type hot when the ratio of the total number of moles of isocyanate groups (-NCO) to the total number of moles of hydroxyl groups (-OH) (total number of isocyanate groups / total number of hydroxyl groups) is 1.5 or more Melt adhesives have excellent thermal creep resistance. Unreacted polyisocyanate compound when the ratio of the total number of moles of isocyanate group (-NCO) and the total number of moles of hydroxyl group (-OH) (total number of isocyanate groups / total number of hydroxyl groups) is 3 or less And suppress the foaming of the moisture-curable hot melt adhesive during the moisture curing of the moisture-curable hot melt adhesive.

  As a synthesis method of urethane prepolymer, for example, a raw material composition containing polyester polyol, polyether polyol, acrylic copolymer and tackifier is heated to 80 to 140 ° C. to be in a molten state, and the raw material composition is decompressed. Dehydration treatment is done at the bottom. Thereafter, a polyisocyanate compound is added to the raw material composition in a molten state under a nitrogen atmosphere, and the raw material composition and the polyisocyanate compound are reacted to synthesize a urethane prepolymer.

(Other additives)
The moisture-curable hot melt adhesive contains the above-mentioned urethane prepolymer, but may contain an additive other than the urethane prepolymer.

  Additives are not particularly limited as long as they do not impair the physical properties of the moisture-curable hot melt adhesive, and examples thereof include oils, plasticizers, thermoplastic resins, curing catalysts, stabilizers, fillers, antioxidants, and light stability. Agents, UV absorbers, colorants, flame retardants, perfumes, pigments, dyes, polymers having hydrolyzable silyl groups, and the like. The additives may be used alone or in combination of two or more.

  Examples of oils include process oils, extender oils, softeners, naphthenic oils and paraffinic oils. The oils may be used alone or in combination of two or more.

  As the plasticizer, for example, phosphate esters such as tributyl phosphate and tricresyl phosphate, phthalate esters such as dioctyl phthalate, fatty acid-basic acid esters such as glycerin monooleate, fatty acid dibasic such as dioctyl adipate Basic acid ester, aliphatic ester such as butyl oleate, methyl acetyl ricinoleate, trimellitic ester, chlorinated paraffin, alkyl diphenyl, hydrocarbon oil such as partially hydrogenated terphenyl, process oil, epoxidized soybean oil , Epoxy plasticizers for epoxy benzyl stearate, vinyl polymers obtained by polymerizing vinyl monomers, and polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate and pentaerythritol ester. An ester of Le and the like. The plasticizer may be used alone or in combination of two or more.

  As a thermoplastic resin, for example, polyvinyl acetate, polystyrene derivative, polyisobutene, polyolefins, polyalkylene oxides, polyurethanes, polyamides, natural rubber, polybutadiene, polyisoprene, nitrobutadiene rubber (NBR), styrene-butadiene- Styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), hydrogenated nitrobutadiene rubber (hydrogenated NBR), hydrogenated Styrene-butadiene-styrene block copolymer (hydrogenated SBS), hydrogenated styrene-isoprene-styrene block copolymer (hydrogenated SIS), and hydrogenated styrene-ethylene-butylene-styrene block copolymer (hydrogenated SEBS) ) It can be mentioned. The thermoplastic resins may be used alone or in combination of two or more.

  The curing catalyst is used to improve the moisture reactivity of the moisture curable hot melt adhesive. As a catalyst, an amine curing catalyst, a tin curing catalyst, etc. are used. The amine curing catalyst is not particularly limited, but is preferably a morpholine compound. Specific examples of morpholine compounds include 2,2′-dimorpholinodiethyl ether, bis (2,6-dimethylmorpholinoethyl) ether, and 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-morpholino) ethyl) amine, Examples of the tin-based curing catalyst include, but are not limited to, tin (1) acid, dibutyltin dilaurate, dibutyltin dioctate, and dibutyltin di-thioate. Acetate, dioctyltin dilaurate, dioctyltin dioctoate, dioctyltin diacetate, and stannous dioctoate etc. The curing catalyst may be used alone or in combination of two or more.

  The stabilizer is not particularly limited, but an organic phosphorus compound is preferable. Examples of organic phosphorus compounds include tricresyl phosphate, triethyl phosphate, tributyl phosphate, tris (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, tris And isopropylphenyl) phosphate, cresyl diphenyl phosphate, triphenyl phosphite, triphenyl phosphine, triphenyl phosphine oxide, aromatic phosphoric acid condensed ester. Among them, organic phosphorus compounds which are solid at normal temperature are preferable, and triphenyl phosphite, triphenyl phosphine, triphenyl phosphine oxide, and aromatic phosphoric acid condensed ester 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 speed of the moisture curable hot melt adhesive. The stabilizers may be used alone or in combination of two or more.

  Examples of fillers 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 formed of resins and vinylidene chloride resins and the like, and particles formed of resins such as PVC (polyvinyl chloride) and PMMA (polymethyl methacrylate). The fillers may be used alone or in combination of two or more.

  Examples of the antioxidant include monophenol-based antioxidants, bisphenol-based antioxidants, and polyphenol-based antioxidants. The antioxidant may be used alone or in combination of two or more.

  As the light stabilizer, for example, a hindered amine light stabilizer is suitably used. Among them, hindered amine light stabilizers in which the amine moiety is a tertiary amine are more preferable. As a light stabilizer, for example, 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 decanedioate -Piperidinyl) 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 -Piperidylse Sebacate, and bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) can be mentioned are. Light stabilizers such sebacate may also be alone, or two or more are used alone.

  As a ultraviolet absorber, a benzotriazole type ultraviolet absorber, a benzophenone type ultraviolet absorber, etc. are mentioned, for example. The ultraviolet absorber may be used alone or in combination of two or more.

  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 a 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. Be

  As the hydrolyzable silyl group, an alkoxysilyl group in which an alkoxy group is bonded to a silicon atom is preferable because no harmful byproducts are generated after the reaction. As said alkoxy group, a methoxy group, an ethoxy group, a propyloxy group, isopropyloxy group, butoxy group, a tert- butoxy group, a phenoxy group, a benzyloxy group etc. can be mentioned, for example. Among these, methoxy and ethoxy are preferable.

  Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group and triphenoxysilyl group; dialkoxysilyl groups such as dimethoxymethylsilyl group and diethoxymethylsilyl group And 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.

  Preferred examples of the main chain of the polymer having a hydrolyzable silyl group include polyalkylene oxides, polyether polyols, (meth) acrylate polymers and polyolefins. 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 of these, and alkylene oxide adducts of bisphenol A. As a monomer which comprises a (meth) acrylate type 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. Examples of the polyolefin include homopolymers and copolymers such as ethylene and propylene. Specifically, polyethylene (for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE) And metallocene catalyzed polyethylene, high density polyethylene (HDPE), etc., polypropylene (PP), ethylene-α-olefin copolymer (ethylene-propylene copolymer etc.) and the like.

[Flooring]
The moisture-curable hot melt adhesive of the present invention described above is suitably used for the production of flooring. The moisture-curable hot melt adhesive is preferably used to bond and integrate a floor board and a foam (preferably, a urethane foam).

  It does not restrict | limit especially as a structure of a flooring, The structure of a conventionally well-known floor board and foam (foam) is mentioned. For example, there is a floor material in which a floor plate and a foam sheet are bonded and integrated by the moisture-curable hot melt adhesive.

  Since the moisture curing type hot melt adhesive has the constitution as described above, while the basic performance required for the moisture curing type hot melt adhesive is high in ordinary adhesive strength and heat creep resistance, Since the retention of foam at high temperature (40 ° C.) is excellent, peeling and lifting of foam can be suppressed even under high temperature in summer.

  The melt viscosity of the moisture-curable hot melt adhesive is preferably 20000 mP · s or less at 120 ° C. When the melt viscosity of the moisture-curable hot melt adhesive is 20000 mP · s or less, excellent workability is obtained. The melt viscosity of the moisture-curable hot melt adhesive is measured using a B-type viscometer under conditions of a temperature of 120 ° C. and a rotation speed of 20 rpm in accordance with Japan Adhesive Industry Association standard JAI-7-1999. It refers to the melt viscosity obtained. In addition, as a Brookfield viscometer, it is marketed from Brookfield Co., Ltd., for example under the trade name "B-shaped Viscometer digital rheometer DVII (rotor No. 29)".

  As a manufacturing method of a floor material, for example, after making it harden by heating a moisture hardening type hot melt adhesive at 100-120 ° C, it applies to the back side of a floor board material, and is applied to a moisture hardening type hot melt adhesive applied The foams are stacked to obtain a laminate. There is a method of curing a moisture-curable hot melt adhesive by curing the laminate, thereby forming an adhesive layer and obtaining a floor material in which a floor board and a foam are adhered and integrated by the adhesive layer. It can be mentioned.

  A roll coater, a spray coater, etc. are mentioned as a method of apply | coating the heat-melted moisture hardening type hot melt adhesive on a floor board material.

  In addition, the floor plate material, the moisture-curable hot melt adhesive, and the foam may be crimped in the thickness direction by performing roll press, flat press, belt press, etc. on the laminate before curing the laminate. preferable.

  As floor plate materials used for floor materials, 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 resins such as chlorinated polypropylene resin and melamine resin; natural wood, plywood, medium density fiber board (MDF) particle board, hard 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. The floor board may be made of one or more of these materials. In the floor board material, plasma treatment, electrodeposition coating treatment such as acrylic resin and melamine acrylic resin, and primer treatment such as alumite treatment are performed on the surface to be adhesively integrated with the adhesive layer, if necessary. It may be Moreover, a groove part, embossing, etc. may be formed in the surface adhesively integrated with the adhesive layer.

  The usage of the moisture curable hot melt adhesive will be described. After the moisture curing type hot melt adhesive is heated and melted at 100 to 130 ° C., the moisture curing type hot melt adhesive in a molten state is drained from a storage container such as an aluminum pack and applied to an adherend. Another adherend is superimposed on the moisture-curable hot melt adhesive applied to the adherend, and the two adherends are superimposed via the moisture-curable hot melt adhesive. At this time, since the moisture-curable hot melt adhesive maintains excellent initial adhesive strength for a long time, the two adherends are reliably superposed via the moisture-curable hot melt adhesive. Can be held. Furthermore, since the moisture-curable hot melt adhesive has a long open time, alignment of two adherends can be easily performed.

  Thereafter, the moisture curable hot melt adhesive is cured by leaving the moisture curable hot melt adhesive at preferably 20 to 25 ° C. in an environment of relative humidity 50 to 60% for 120 to 168 hours. Thus, two adherends can be bonded and integrated. The moisture curable hot melt adhesive has excellent normal adhesive strength and heat creep resistance so that the two adherends are stably bonded and integrated over a long period of time.

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

  First, details of each component used for producing a moisture-curable hot melt adhesive in Examples and Comparative Examples described later will be described.

(Polyester polyol)
・ Crystalline polyester polyol (A1)
Crystalline polyester polyol (number average molecular weight: 3600, Ube Industries, Ltd.) formed by condensation polymerization of dodecanedioic acid (C12) (1, 10-decanedicarboxylic acid) and 1,6-hexanediol (C6) Product name "ETERNACOLL 3010")
・ Crystalline polyester polyol (A2)
Crystalline polyester polyol obtained by condensation polymerization of adipic acid (carbon number 6) and 1,6-hexanediol (carbon number 6) (number average molecular weight: 2000, manufactured by Toyokuni Oil Co., Ltd .; trade name "HS2H-201AP")
・ Crystalline polyester polyol (A3)
Crystalline polyester polyol obtained by condensation polymerization of sebacic acid (10 carbon atoms) and 1,6-hexanediol (6 carbon atoms) (number average molecular weight: 2000, manufactured by Toyokuni Oil Co., Ltd., trade name "HS2H-200S")
・ Non-crystalline polyester polyol (A4)
Amorphous polyester polyol (number average molecular weight: 2000, manufactured by Toyokuni Oil Co., Ltd., trade name "HS2F-237P")

(Polyether polyol)
・ Polyether polyol (B1)
Polypropylene glycol (number average molecular weight: 2000, manufactured by Asahi Glass Co., Ltd., trade name "EXENOL 2020")
・ Polyether polyol (B2)
Polypropylene glycol (number average molecular weight: 3000, manufactured by Asahi Glass Co., Ltd., trade name "EXENOL 3020"
・ Polyether polyol (B3)
Polypropylene glycol (number average molecular weight: 1000, manufactured by Asahi Glass Co., Ltd., trade name "EXENOL 1020")

(Acrylic copolymer)
-Acrylic copolymer (C1) (number average molecular weight: 140,000, glass transition temperature: 65 ° C, manufactured by Evonik Japan, trade name "DYNACOAL AC1750")
-Acrylic copolymer (C2) (number average molecular weight: 60000, glass transition temperature: 63 ° C, manufactured by Evonik Japan, trade name "DYNACOL AC1630")

(Tackifier)
· Tackifier (D1) (ring ball rapid softening point: 100 to 108 ° C. KOMO manufactured by CHEMICALS, trade name "KF-454S")
-Tackifier (D2) (ring and ball softening point: 110 to 116 ° C KOMO manufactured by CHEMICALS, trade name "KF-462S")

(Polyisocyanate compound)
・ 4,4'-diphenylmethane diisocyanate

(Examples 1 to 11, Comparative Examples 1 to 8)
Polyester polyols (A1) to (A3), polyether polyols (B1) to (B3), acrylic copolymers (C1) to (C2) and tackifiers (D1) of predetermined amounts shown in Table 1 (D2) was charged into a 1-liter four-necked flask having a stirring blade, heated to 140 ° C. to melt, and a raw material composition in a molten state was obtained.

  The obtained raw material composition was subjected to dehydration treatment under a reduced pressure of 133.3 Pa (1 mmHg) or less, and then the inside of the flask was purged with nitrogen gas, and the raw material composition was cooled to 80 ° C. Next, to the raw material composition in the flask, a predetermined amount of 4,4'-diphenylmethane diisocyanate shown in Table 1 was added. Ratio of the total number of moles of isocyanate groups (-NCO) to the total number of moles of hydroxyl groups (-OH) in the total amount of the raw material composition and 4,4'-diphenylmethane diisocyanate (total number of moles of isocyanate groups / total moles of hydroxyl groups The numbers are shown in Table 1.

  The inside of the flask was reacted by stirring under a nitrogen gas atmosphere for 3 hours to obtain a moisture-curable hot melt adhesive containing a urethane prepolymer having an isocyanate group at the end.

  The obtained moisture curable hot melt adhesive was measured for melt viscosity at 120 ° C., initial convergence test (initial adhesion test), normal adhesive strength and heat creep test according to the following procedure, and the results are shown in Table 1 It was shown to.

(Melt viscosity)
Using a B-type viscometer commercially available from Brookfield Co., Ltd. under the trade name “B-type viscometer digital rheometer DVII (rotor No. 29)”, the temperature is 120 according to JAI-7-1999 based on Japan Adhesive Industry Association standards It measured on the conditions of ° C.
The case where the viscosity was 20000 mPa · s or less was taken as “○”, and the case where it exceeded 20000 mPa · s was taken as “x”.

(Initial Settability Test (Initial Adhesion Test))
After the moisture-curable hot melt adhesive is heated to 120 ° C. and melted, the molten moisture-curable hot melt adhesive is a flat rectangular olefin sheet (thickness 180 μm) whose surface temperature is adjusted to 40 ° C. The coating thickness was 50 μm on one side. Thereafter, an olefin sheet is superposed on a medium density fiber (medium density fiber board, hereinafter referred to as MDF) substrate whose surface temperature is adjusted to 40 ° C. via a coated moisture-curable hot melt adhesive, A test piece was obtained by rolling a rubber roll on an olefin sheet and pressing the olefin sheet and the MDF substrate.

  After placing the test piece horizontally so that the olefin sheet was on the lower surface under an atmosphere of 40 ° C., a weight of 30 g / 25 mm was applied in the vertical direction to one end in the length direction of the olefin sheet. After 2 minutes in this state, the length (mm) at which the olefin sheet peeled was measured.

(Normal adhesive strength)
After the moisture-curable hot melt adhesive was heated to 120 ° C. for melting, a molten moisture-curable hot melt adhesive was applied to the MDF substrate at a coating weight of 60 g / m ² . Thereafter, after laminating the urethane foam through the coated moisture-curable hot melt adhesive, the rubber roll is rolled on the urethane foam to press-bond the urethane foam and the MDF substrate, thereby a laminate is obtained. I got

Next, the moisture curable hot melt adhesive was cooled and solidified by leaving the laminate under an environment of temperature 23 ° C. and relative humidity 55% for 1 hour. Thereafter, the moisture curable hot melt adhesive was moisture cured by leaving the laminate at a temperature of 23 ° C. and a relative humidity of 55% for one week. And it cut into the square of the size of 50 mm x 50 mm from a layered product, and obtained the test piece. The maximum tensile strength when the urethane foam was pulled from the adhesive surface in the vertical direction at a moving speed of 5 mm / min was measured as “normal adhesion strength (N / mm ² )”.

(Heat resistant creep test)
Test pieces were prepared in the same manner as the above-described procedure for measurement of normal adhesive strength. In a temperature environment of 60 ° C., the test piece was placed horizontally so that the urethane foam was on the lower surface, and then one edge of the urethane foam was subjected to a load of 500 g / 25 mm in the vertical direction. After 24 hours in this state, the length (mm) at which the urethane foam peeled was measured.

Claims (3)

  Polyester polyol which is a condensation polymer of linear polycarboxylic acid having 6 to 12 carbons and linear polyol having 2 to 6 carbons, polyether polyol, glass transition temperature is 50 to 90 ° C. An acrylic copolymer, and a reaction product of a raw material composition containing a tackifier and a polyisocyanate compound, and containing an isocyanate group at the end, the above polyester polyol, the above polyether polyol, the above acrylic The total amount of the copolymer, the tackifier and the polyisocyanate compound is 100% by mass, 10 to 30% by mass of the polyester polyol, 30 to 50% by mass of the polyether polyol, and 10 to 20 of the acrylic copolymer Moisture-curable type characterized in that it contains by mass and 5 to 15% by mass of the above-mentioned tackifier Ttomeruto adhesive.   The moisture curable hot melt adhesive according to claim 1, wherein the polyester polyol is a polyester polyol. The moisture curable hot melt adhesive according to claim 1 or 2, wherein the melt viscosity at 120 ° C is 20000 mPa · s or less.