A method for manufacturing heat-bondable sheet having water repellency

[Industrial Application Field] The present invention relates to a method for manufacturing a water-repellent heat-adhesive sheet used for, for example, a hood silencer in an automobile engine room.

[0002] For example, a hood silencer in an automobile engine room has a structure in which a skin material made of a fiber sheet is adhered to a surface of a porous sheet. When the skin material is adhered to the surface of the porous sheet, a hot melt sheet is usually used, but the hot melt sheet is not breathable and hinders the soundproofing property of the hood silencer.

[0003] Therefore, recently, when adhering a skin material to the surface of a porous sheet, a hot melt adhesive powder is used. In this case, the hot melt adhesive powder is adhered to the adhesive surface of the skin material, and the skin material is superposed on the surface of the porous sheet and heat-bonded.

[0004] As a method of adhering the hot melt adhesive powder to the skin material adhesive surface, a method of spraying the hot melt adhesive powder on the skin material adhesive surface or an aqueous dispersion in which the hot melt adhesive is dispersed in water. A method of spraying and drying the liquid is applied.

[0005] However, there is fluff on the surface of the fiber sheet which is the skin material, and if the hot melt adhesive powder penetrates to the root of the fluff, the hot melt adhesive powder may be covered with the fluff and may not work effectively for adhesion. There is. Therefore, it has recently been proposed to impart structural viscosity to an aqueous dispersion of hot melt adhesive powder and then spray it on the adhesive surface of the fiber sheet (WO00 / 52110).

[0006] [Problem to be Solved by the Invention] For example, in the case of a hood silencer in an engine room of an automobile, a water repellent treatment is applied so that water does not permeate even if water adheres to the surface of the skin material. To apply water-repellent treatment to the skin material, (1) First, impregnate the skin material with a water-repellent aqueous solution and heat-dry it, then spray the adhesive surface with a hot-melt adhesive powder aqueous dispersion and heat-dry it. , (2) Hot melt adhesive A method of adding a water repellent to an aqueous dispersion and spraying it on the adhesive surface of the skin material.

[0007] In the method (1) above, the heating and drying step is required twice, and especially when processing a long sheet, it is necessary to pass through two heating and drying furnaces, which is troublesome equipment. The cost is also high. In particular, when the skin material is first impregnated with a water-repellent aqueous liquid and dried by heating, then when the hot melt adhesive powder aqueous dispersion is sprayed on the skin adhesive surface, the aqueous dispersion is repelled and becomes uniform. There is a problem that the aqueous dispersion cannot be applied.

[0008] In the method (2) above, the heating and drying step is one step, but since the hot melt adhesive powder aqueous dispersion has structural viscosity, the aqueous dispersion containing the water repellent is included. Since the liquid stays on the adhesive surface of the skin material and does not easily penetrate into the surface of the skin material, sufficient water repellency is not imparted to the surface of the skin material.

[Means for Solving the Problems] In order to solve the above problems, the present invention impregnates a fiber sheet (3A) with an aqueous water repellent solution, and then in an undried state, the fiber sheet (3A). ) Hot melt adhesive powder having structural viscosity on the surface (4) Spray the aqueous dispersion and dry it to attach the hot melt adhesive powder (4) to the upper end of the fluff on the surface of the fiber sheet (3A). It provides a method for manufacturing a water-repellent hot-adhesive sheet (1). The hot melt adhesive powder (4) The aqueous dispersion is preferably imparted with structural viscosity by an alkaline thickening type thickener, and the water repellent aqueous liquid and / or the hot melt adhesive powder ( 4) A flame retardant may be added to the aqueous dispersion.

[Action] After impregnating the fiber sheet (3A) with the water-repellent aqueous solution, the hot-melt adhesive powder (4) aqueous dispersion is sprayed on the surface of the fiber sheet in an undried state. The aqueous dispersion is uniformly applied without being repelled by the adhesive surface of the fiber sheet (3A). Further, since the aqueous dispersion has structural viscosity, when sprayed on the adhesive surface of the fiber sheet (3A), the aqueous dispersion is less likely to cause dripping or the like on the adhesive surface of the fiber sheet (3A). Is easily applied uniformly to the adhesive surface of the fiber sheet (3A) in a predetermined amount, and the aqueous dispersion does not easily enter the inside of the fluff on the adhesive surface of the fiber sheet (3A). (4) will almost always adhere to the tip surface of the fluff.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. [Water-repellent aqueous solution] As the water-repellent agent used for the water-repellent treatment of the fiber sheet in the present invention, general hydrocarbon derivatives such as paraffin and wax, fatty acid derivatives, organopolysiloxane, fluorocarbon, fatty acid zirconium salt and the like are used. These water repellents are used in the form of aqueous dispersions or aqueous solutions such as aqueous emulsions. In the above aqueous liquid, the water repellent is usually contained in the range of 0.05 to 20% by weight.

[Hot Melt Adhesive Powder Aqueous Dispersion] The hot melt adhesive used in the present invention is, for example, a polyolefin resin such as polyethylene, polypropylene, an ethylene-vinyl acetate copolymer, or an ethylene-ethyl acrylate copolymer. Alternatively, the modified product of the polyolefin resin, polyvinyl chloride, polyurethane, polyester, polyester copolymer, polyamide, polyamide copolymer and the like may be used alone or in combination of two or more, and the powder of the hot melt adhesive is usually used. The size is about 50 to 300 mesh.

[0013] The hot melt adhesive powder is dispersed in water to prepare an aqueous dispersion, and a water-soluble thickener is added to impart structural viscosity to the aqueous dispersion. Examples of the water-soluble thickener include polyacrylic acids such as sodium polyacrylate, ammonium polyacrylate, sodium polymethacrylate, and ammonium polymethacrylate, salts of polymethacrylic acid, polyvinyl alcohol, polyethylene oxide, carboxymethyl cellulose, and methyl cellulose. , Viscous, starch, modified starch, casein, gelatin, arabic gum, pectin and the like. The water-soluble thickener tends to form a powder when dissolved in water. Therefore, a particularly desirable thickener in the present invention is an alkaline thickening type thickener.

[0014] The first thickening agent desirable as the alkaline thickening type thickener is an alkaline thickening type acrylic copolymer emulsion, and the desirable second thickening agent is a microcrosslinked poly. Acrylic acid. Examples of the alkali thickening type acrylic copolymer include a copolymer of an acrylic acid ester and an α, β-unsaturated carboxylic acid, an acrylic acid ester, and another vinyl copolymerizable with the acrylic acid ester. A multiple copolymer of a monomer and an α, β-unsaturated carboxylic acid can be used.

[0015] Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and tetrahydrofurfuryl acrylate. Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, stearyl methacrylate, lauryl methacrylate, β-hydroxyethyl acrylate, β-hydroxy Examples thereof include ethyl methacrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0016] Examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, atropic acid, and citraconic acid.

[0017] Examples of other vinyl monomers copolymerizable with the above acrylic acid ester include ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether, styrene, and α-. Stylenes such as methylstyrene, cyano group-containing monomers such as (meth) acrylonitrile, isocyanate group-containing monomers such as (meth) acryloyl isocyanate, m-isopropenyl-α, α-dimethylbenzylisocyanate, diacetoneacrylamide. , N-vinylformamide, N-vinylacetamide and other amide group-containing monomers, p-sulfonic acid styrene, 2- (acryloylamino) -2-methylpropanesulfonic acid and other sulfonate group-containing monomers, mercaptopropyltri Examples thereof include mercapto group-containing monomers such as methoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, and mercaptopropyltrimethoxysilane.

[0018] In the acrylic copolymer emulsion, the α, β-unsaturated carboxylic acid is water-soluble when the α, β-unsaturated carboxylic acid is salted with an alkali. It is contained in the acrylic copolymer in a sufficient amount to become. The amount of the α, β-unsaturated carboxylic acid varies depending on the above acrylic acid ester, other vinyl monomer or the type of the α, β-unsaturated carboxylic acid, but is usually 20 to 60 in the copolymer. It is contained in% by weight, preferably 30 to 50% by weight.

[0019] The acrylic copolymer may be crosslinked to such an extent that it does not adversely affect its water solubility. In this case, a polyfunctional vinyl monomer such as divinylbenzene, methylene bisacrylamide, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, and diallyl phthalate is contained in the copolymer. Introduce.

[0020] In order to prepare a hot melt adhesive powder aqueous dispersion using the alkaline thickening type acrylic copolymer emulsion as a thickener, first, the acrylic copolymer emulsion and the hot melt adhesive are prepared. It is preferable to add the powder to water and stir to obtain a dispersion. At this stage, since the acrylic copolymer emulsion is not thickened, it is extremely easy to disperse it uniformly in water. The powder of the hot melt adhesive does not need to be added to water at the same time as the acrylic copolymer emulsion, and may be added to water at any stage, but is preferably added before thickening.

[0021] The hot melt adhesive powder is usually dispersed in water in the range of 1 to 60% by weight, and the acrylic copolymer emulsion is the viscosity of the hot melt adhesive aqueous dispersion after alkali thickening. Is added to the water so that the value is 50 to 2000 mPa · s / 25 ° C. For example, when a 30% by weight emulsion of a copolymer obtained by copolymerizing ethyl acrylate and methacrylic acid at a weight ratio of 6: 4 is used, the amount of the emulsion added is about 0.1 to 10% by weight.

[0022] As described above, the acrylic copolymer emulsion and the powder of the hot melt adhesive are added to water, and after uniformly mixing, an alkali is added. Then, the carboxylic acid derived from the α, β-unsaturated carboxylic acid contained in the acrylic copolymer becomes a salt, the copolymer becomes water-soluble, and the dispersion liquid is thickened. Examples of the alkali include ammonia and amines; alkali metals such as sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide and hydroxides of alkaline earth metals; oxides of alkaline earth metals such as lime; carbon dioxide. Weak acid salts of alkali metals such as sodium, sodium sulfite, sodium acetate, and sodium phosphate can be used. The amount of the alkali added is usually determined with the pH of the dispersion liquid being about 6 to 9 as a guide. As described above, the hot melt adhesive powder aqueous dispersion using the alkaline thickening type acrylic copolymer emulsion as a thickener exhibits plastic flow, and the precipitation of the hot melt adhesive powder is substantially prevented. ..

On the other hand, the finely crosslinked polyacrylic acid, which is a desirable second thickener, can usually be produced by the following precipitation polymerization method. As the solvent, one in which acrylic acid is dissolved and polyacrylic acid is not dissolved, for example, an organic solvent such as benzene, ethyl acetate, cyclohexane, toluene or a mixture thereof is used, and acrylic acid, a cross-linking agent and polymerization are used in the solvent. Mix the initiator. Examples of the cross-linking agent include polyfunctional vinyl monomers such as divinylbenzene, diallyl phthalate, tetraaryloxyethane, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and trimethylolpropane dimethacrylate, and saccharides such as allyl saccharose. Can be used. The cross-linking agent is usually used in an amount of 1% or less, preferably about 0.05% with respect to acrylic acid.

[0024] Examples of the polymerization initiator include benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, t-butyl peroxide, t-butyl peroxybenzoate, and t-. Butyperoxy-2-ethylhexanate, t-butylperoxypivalate, t-butylperoxyneodecanoate, 3,5,5-trimethylhexanoyl peroxide, diisopropylbenzenehydroperoxide, lauroyl peroxide, Peroxide-based polymerization initiators such as dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitronitrile, 2,2'-azobis-2 , 4'-Dimethylvaleronitrile, 2,2'-azobis-2-cyclopropylpropionitrile, 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, 1,1'-azobiscyclohexane Use azo polymerization initiators such as -1-carbonitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis-N, N'-dimethyleneisobutyramidine. be able to.

[0025] When acrylic acid is polymerized in a solvent as described above, microcrosslinked polyacrylic acid is precipitated in the form of powder. The precipitated polyacrylic acid is dried to obtain a powder. The polyacrylic acid thus obtained is crosslinked at a low density such that water solubility is maintained. When the crosslink density of the polyacrylic acid is high, the polyacrylic acid becomes water-swellable and difficult to dissolve in water, and when the crosslink density is further high, it becomes water-insoluble.

[0026] In order to prepare an aqueous dispersion of a hot melt adhesive powder using the microcrosslinked polyacrylic acid as a thickener, first, the powder of the microcrosslinked polyacrylic acid and the hot melt adhesive is watered. It is preferable to add and stir to the dispersion liquid. At this stage, the microcrosslinked polyacrylic acid is not so thickened and is unlikely to form a splicing powder, so that it is relatively easy to disperse it uniformly in water. The powder of the hot melt adhesive does not need to be added to water at the same time as the microcrosslinked polyacrylic acid, and may be added to water at any stage, but is preferably added before thickening. The hot melt adhesive powder is usually dispersed in water in the range of 1 to 60% by weight, and the microcrosslinked polyacrylic acid is finally (including the case of neutralizing and thickening) the hot melt. The adhesive dispersion is added to the water so that the viscosity of the adhesive dispersion is 50 to 2000 mPa · s / 25 ° C.

[0027] The microcrosslinked polyacrylic acid added to water as described above dissolves and thickens the water (dispersion liquid), but in order to further increase the viscosity, it is neutralized with an alkali. When neutralized with alkali, a negative charge is generated along the polymer skeleton of the polyacrylic acid, and the negative charges repel each other, so that the bent / curved polymer skeleton is elongated and the water is further increased. It can be made sticky (or thickened with a small amount). As the alkali, it is preferable to use ammonia or amines such as triethanolamine, diisopropanolamine, aminomethylpropanol, tromethamine and tetrahydroxypropylethylenediamine, but sodium hydroxide, potassium hydroxide and the like should be used. You can also. The amount of the alkali added is usually determined with the pH of the dispersion liquid being about 6 to 9 as a guide.

[0028] A part of the carboxyl groups in the microcrosslinked polyacrylic acid may be salted in advance by an alkali, but if the degree of neutralization is high, it becomes a splicing powder when dispersed in water. Since it is easy, it is necessary to set the degree of neutralization low enough not to form crosslinks.

[0029] As described above, the hot melt adhesive powder aqueous dispersion using the microcrosslinked polyacrylic acid as a thickener exhibits plastic flow, and the settling of the hot melt adhesive powder is substantially prevented.

[0030] As a thickener in the hot melt adhesive powder aqueous dispersion of the present invention, an alkaline thickening type acrylic copolymer emulsion and a microcrosslinked polyacrylic acid can be used in combination.

[0031] Examples of the hot melt adhesive powder aqueous dispersion include higher alcohol sulfate (Na salt or amine salt), alkylallyl sulfonate (Na salt or amine salt), and alkylnaphthalene sulfonate (Na salt or amine salt). Anionic surfactants such as salts), alkylnaphthalene sulfonate condensates, alkyl phosphates, dialkyl sulfosuccinates, rosin soaps, fatty acid salts (Na salts or amine salts), polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers. , Polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamine, polyoxyethylene alkyl amide, sorbitan alkyl ester, polyoxyethylene sorbitan alkyl ester and other nonionic surfactants, octadecylamine acetate, imidazoline derivative One or two kinds of surfactants such as acetate, polyalkylene polyamine derivative or salt thereof, octadecyltrimethylammonium chloride, trimethylaminoethylalkylamide halogenide, alkylpyridinium sulfate, cationic surfactant such as alkyltrimethylammonium halogenide The above may be added as a dispersant.

[0032] Further, in the hot melt adhesive powder aqueous dispersion, for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, vinyl chloride resin, vinylidene chloride resin, styrene. Based resin, vinyl acetate resin, fluorine resin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, epoxy resin, melamine resin, urea resin, phenol resin, resorcin resin, alkyl resorcin resin, etc. Synthetic resin emulsions such as thermocurable resins, acrylonitrile-butadiene copolymers, styrene-butadiene copolymers, acrylonitrile-butadiene-styrene copolymers; acrylic rubber, butyl rubber, silicon rubber, urethane rubber, fluoride rubber, Polysulfide rubber, graft rubber, butadiene rubber, isoprene rubber, chloroprene rubber, polyisobutylene rubber, polybutene rubber, isobutene-isoprene rubber, acrylate-butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, pyridine-butadiene rubber, Styrene-isoprene rubber, acrylonitrile-chloroprene rubber, styrene-chloroprene rubber, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-hydrogenated polyolefin-styrene copolymer, butadiene-styrene block co-weight Combined, synthetic rubber or elastomer powders such as block copolymers such as styrene-rubber intermediate block-styrene copolymers or emulsions thereof may be added. If necessary, fillers such as calcium carbonate, talc, gypsum, silica, carbon black, wood flour, walnut powder, coconut husk powder, starch, celluloses such as carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, pigments, dyes, insect repellents , Preservatives, anti-aging agents, UV absorbers, fluorescent dyes, surfactants, foaming agents, softeners such as paraffin, wax and silicone, oil repellents, mold release agents, plasticizers and the like may be added.

[0033] When the dispersion in which the powder of the hot melt adhesive is dispersed in water is made alkaline by the third component or by an alkali added separately, the alkali is added to the dispersion. It can be thickened by adding and mixing a viscous type thickener.

[Heat Adhesive Sheet] Examples of the fiber sheet used in the heat adhesive sheet of the present invention include polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, acrylic fiber, urethane fiber, polyvinyl chloride fiber, and poly. Synthetic fibers such as vinylidene chloride fiber and acetate fiber, natural fibers such as pulp, cotton, wool, palm fiber, hemp fiber and bamboo fiber, glass fiber, carbon fiber, ceramic fiber, inorganic fiber such as asbestos, or these fibers There are knitted textiles or non-woven fabrics made of one or more kinds of fibers such as recycled fibers obtained by defibrating the scraps of used textile products. A napped layer may be formed on the surface of the fiber sheet by needling or tufting. Desirable fiber sheets include polyester fibers, polyamide fibers, natural fibers, inorganic fibers having a melting point of 250 ° C or higher, polyester fibers having a melting point of 200 ° C or lower, polyamide fibers, polyethylene fibers, polypropylene fibers, etc. There are thermoformable non-woven fibers in which seeds and above are mixed. The fiber sheet is first subjected to a water repellent treatment.

[0035] In the water-repellent treatment, the fiber sheet is immersed in a water-repellent aqueous solution. The impregnation amount of the water repellent agent is controlled by the concentration of the water repellent agent in the water repellent aqueous solution or the impregnation amount of the water repellent aqueous solution. To control the impregnation amount of the water-repellent aqueous solution, the fiber sheet is squeezed with a drawing roll in the water-repellent aqueous solution, or the fiber sheet is taken out from the water-repellent aqueous solution and then the fiber sheet is squeezed with a drawing roll. It is done by squeezing. Normally, the water repellent is 0.01 g / m as a solid content in the fiber sheet.²~ 20g / m²Impregnated to some extent.

[0036] After impregnating the fiber sheet with the water-repellent aqueous solution by a spray method, a dipping method, or the like, the hot-melt adhesive is adhered before the water-repellent aqueous solution impregnated in the fiber sheet dries. The agent powder aqueous dispersion is sprayed on the fiber sheet adhesive surface. As a method of spraying the above-mentioned hot melt adhesive powder aqueous dispersion on the adhesive surface of the fiber sheet, a method of directly applying a high pressure to the aqueous dispersion and air-spraying the aqueous dispersion is preferable. According to such a method, even when the viscosity of the hot melt adhesive powder aqueous dispersion is high, the aqueous dispersion can be efficiently spray-coated. At this time, the hot melt adhesive powder aqueous dispersion does not necessarily have to be agitated, but may be agitated. The coating amount is usually 1 to 100 g / m as a solid content.²Is. The hot melt adhesive powder aqueous dispersion may be produced in advance at a high concentration and diluted with water to a desired concentration at the time of use. Since the hot melt adhesive powder aqueous dispersion liquid spray-coated as described above has structural viscosity, it does not enter between the fluffs on the adhesive surface of the fiber sheet, but adheres to the fluff surface, and after drying, the fluff. A state in which the hot melt adhesive powder is efficiently adhered to the tip of the water is obtained. Further, since the hot melt adhesive powder aqueous dispersion is applied without sedimentation, the hot melt adhesive powder can be uniformly adhered to the surface to be coated.

[0037] When the hot melt adhesive powder aqueous dispersion is sprayed on the fiber sheet adhesive surface, it is preferable to suck the hot melt adhesive powder from the surface opposite to the adhesive surface. By sucking in this way, it is possible to prevent the hot melt adhesive powder from rebounding due to an impact at the time of spraying, and to reliably adsorb the hot melt adhesive powder to the fiber sheet adhesive surface. After spray-coating the aqueous dispersion as described above, the fiber sheet is heated and dried. The conditions for the heat drying are a temperature equal to or higher than the melting point of the hot melt adhesive used, and usually about 1 to 10 minutes at 70 ° C. or higher. In this way, the heat-adhesive sheet is manufactured.

[Flame-retardant treatment] When the heat-adhesive sheet is used as a skin material for an interior material arranged near a heating element, such as a hood silencer in an engine room, the flame-retardant treatment is performed. It is desirable to apply. Examples of the flame retardant used in the flame retardant treatment include ammonium bromide, ammonium chloride, ammonium phosphate, ammonium sulfate, zinc chloride, aluminum hydroxide, magnesium hydroxide, antimony trioxide, antimony pentoxide, and boric acid. Inorganic flame retardants such as zinc, barium metaborate, molybdenum oxide, organic flame retardants such as halogen compounds, phosphorus compounds, nitrogen compounds and sulfur compounds, chlorine chloride resins such as vinylidene chloride resin and vinyl chloride resin. General materials such as synthetic resins and flame-retardant synthetic resins such as fluorine-based synthetic resins such as vinylidene fluoride resin are used, and two or more of these flame-retardant agents may be mixed, particularly inorganic and organic. When used in combination with the system, an excellent flame retardant effect can be obtained. These fueling agents are preferably added to the water repellent aqueous solution or the hot melt adhesive powder aqueous dispersion.

[0039] The heat-adhesive sheet of the present invention obtained as described above is used for a skin material for automobile interior materials such as a hood silencer for an automobile engine room, a backing material for a base material of an automobile interior material, and an automobile flooring. It can be used for carpets, core materials for clothes, etc.

[Interior Material] The interior material of the present invention is formed by using the heat-adhesive sheet as a skin material and adhering the skin material to the surface of the interior material base material. Examples of the interior material base material include synthetic fibers such as polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, aramid fiber, acrylic fiber, urethane fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, acetate fiber, rayon, and cupra. , Wood fibers such as pulp and wood chips, cotton, wool, silk, hemp, Kenaf fibers, natural fibers such as palm fibers, glass fibers, asbestos, ceramic fibers, carbon fibers, inorganic fibers such as metal fibers, or the above two types of fibers. Recycled fibers obtained by defibrating the above mixed fibers or scraps of products using the above fibers are polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and thermoplastic. Vinylidene, polystyrene, polyvinyl acetate, fluororesin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene co-weight Thermoplastic synthetic resins such as coalescing, urethane resins, melamine resins, thermocurable acrylic resins, urea resins, phenolic resins, resorcin resins, alkylresorcin resins, epoxy resins, thermocurable polyesters, etc. Prepolymers such as urethane resin prepolymer, epoxy resin prepolymer, melamine resin prepolymer, urea resin prepolymer, phenol resin prepolymer, diallyl phthalate prepolymer, acrylic oligomer, thermoplastic isocyanate, methacrylic ester monomer, diallyl phthalate monomer, etc. A fiber sheet bonded with a synthetic resin precursor such as an oligomer or a monomer, a needle punch felt obtained by binding a card web of the fiber by needle punching, and the needle punch felt impregnated with the synthetic resin and / or the synthetic resin precursor. Synthetic resin impregnated felt, melting point 20 on the above fibers Thermoplastic felt, melamine resin obtained by mixing one or more low melting point fibers such as polyethylene fiber, polypropylene fiber, polyester fiber, polyamide fiber, etc. at 0 ° C or less and binding by needle punching and / or heating setting if desired. , Polyurethane, polystyrene, polyvinyl chloride and other synthetic resin foam sheets, fiber-reinforced synthetic resin foam sheets mixed with the fibers as reinforcing fibers, the synthetic resin and / or synthetic resin precursors in the synthetic resin foam sheet. There are a synthetic resin impregnated synthetic resin foam sheet impregnated, a thick paper or a waste paper impregnated with the synthetic resin and / or a synthetic resin precursor, or a laminated base material in which two or more kinds of the above base materials are laminated. A foaming agent may be added to the synthetic resin or synthetic resin precursor used for the interior material base material. The interior material base material is imparted with moldability by a synthetic resin or synthetic resin precursor used as a binder or an impregnating agent, a low melting point fiber, or the like.

[0041] In the interior material base material, it is desirable to impregnate the porous material with the initial condensate of the thermosetting synthetic resin, and further, heat-dry the porous material impregnated with the initial condensate and heat-dry the porous material. It is desirable to slightly condense the initial condensate to bring it into the B state. By putting the initial condensate impregnated in the porous material into the B state, the curing time of the initial condensate can be shortened, and good moldability can be given to the interior material base material by hot pressing for a short time. At the same time, the interior material base material can be stored for a long period of time. In such an interior material base material, since the thermosetting synthetic resin in the B state is completely cured by hot pressing, an interior material base material having excellent shape retention and heat resistance can be obtained.

[0042] As the initial condensate of the thermosetting synthetic resin, it is preferable to use a phenol-based initial condensate which is an initial condensate of monovalent phenol and / or polyhydric phenol and aldehyde, and the phenol-based initial condensate is preferable. The condensate is preferably sulfomethylated and / or sulfimylated.

[0043] Examples of the porous material include fiber aggregates such as organic or inorganic fiber non-woven fabrics, felts, knitted fabrics, and laminates thereof, polyurethane foams having open cells, polyolefin foams such as polyethylene and polypropylene, and polys. There are vinyl chloride foams, polystyrene foams, amino resin foams such as melamine resin and urea resin, continuous foaming plastic foams such as phenol resin foams, and sintered plastic beads.

[0044] In order to bond the skin material to the interior material base material, the hot melt adhesive powder adhered to and formed on the back surface of the skin material is heat-softened and then bonded together. When the interior material base material is molded into a desired shape, the interior material base material is molded before the skin material is bonded, at the same time when the skin material is bonded, or after the skin material is bonded. It may be done at any time. As a molding method, when the interior material base material contains a thermoplastic synthetic resin or a low melting point fiber, the interior material base material is usually heated to soften the thermoplastic synthetic resin or the low melting point fiber. A method of cold press molding after cooling, or a method of vacuum forming when the skin material is non-breathable is applied, and when the interior material base material contains a thermosetting synthetic resin, the method is applied. Usually, a method of hot press molding the interior material base material is applied.

[0045] When the skin material is made of a fiber sheet and has hot melt adhesive powder scattered on the adhesive surface, it has breathability, and the skin material is attached to the interior material base material before molding. In the case of the air contained in the interior material base material or the gas generated from the synthetic resin contained in the interior material base material (for example, formalin gas in the case of phenol resin, in the case of polyvalent isocyanate). Water or carbon dioxide gas) passes through the gaps between the hot melt adhesive powders (softened materials) scattered on the fiber sheet adhesive surface during molding, and is smoothly discharged to the outside world from the skin material. The puncture phenomenon does not occur in the interior material to be used, and the problem of odor due to residual gas is solved.

[0046] The interior material of the present invention can be used for various purposes, and is suitable as, for example, a hood silencer for an automobile engine room, a trunk room interior material, a dashboard interior material, and the like. In the interior material, since the adhesive layers of the hot melt adhesive powder are scattered in dots, the rigidity of the adhesive layer does not affect the molding shape or the uneven shape of the surface of the interior material, and therefore the interior material. The molding shape and uneven shape of the above are sharply molded. Further, since the skin material has breathability and the adhesive layer also has breathability, the obtained interior material has excellent soundproofing property.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples. [Example 1] After dispersing a polyamide adhesive powder having a particle size of 250 mesh in water, the emulsion of a 30% solid ethyl acrylate-methacrylic acid copolymer is thickened while stirring the dispersion. Add as agent a, or add microcross-linked polyacrylic acid (manufactured by Nippon Junyaku Co., Ltd., Junron PW-110) as thickener b, stir to make it uniform, and then add aqueous ammonia to increase. I was sticky. Table 1 shows the mixing ratio of each component. The obtained hot melt adhesive powder dispersions A1 to 8 were placed in a 200 cc glass bottle and allowed to stand at room temperature for 2 months, and the standing stability of the dispersions A1 to 8 was examined. The results are shown in Table 1.

[0048] [Table 1]<img file="JP3824512B2_D0001.tif" />[Comparative Example 1] Hot melt adhesive powder dispersions A9 to 12 were produced in the same manner as in Example 1 except that the above thickeners a and b and aqueous ammonia were not used, and the stability after standing was examined. .. Table 2 shows the mixing ratio of each component and the results of standing stability.

[0050] [Table 2]<img file="JP3824512B2_D0002.tif" />[Comparative Example 2] Hot melt adhesive powder dispersions A13 to 16 are used in the same manner as in Example 1 except that 0.5% sodium polyacrylate is used instead of the thickeners a and b and aqueous ammonia. It was manufactured and its stability after standing was examined. Table 3 shows the mixing ratio of each component and the results of standing stability.

[0052] [Table 3]<img file="JP3824512B2_D0003.tif" />[0053] As is clear from Example 1 and Comparative Examples 1 and 2, simply thickening the hot melt adhesive powder dispersion does not improve the standing stability, and is an alkaline thickening type acrylic copolymer. For the first time, the use of emulsions or microcrosslinked polyacrylic acids dramatically improves storage stability.

[Example 2] In 15 parts by weight of ethylene-vinyl acetate copolymer (EVA) powder having a particle size of 200 mesh, 0.1 part by weight of a surfactant composed of sodium dialkyl sulfosuccinate as a dispersant and as a thickener. Add 1.5 parts by weight of the emulsion of n-butyl methacrylate-itaconic acid copolymer, add more aqueous ammonia with stirring, and add hot melt adhesive powder dispersion B with pH 8.0 and viscosity 310 mPa · s / 25 ° C. Got When the obtained dispersion B was left at room temperature, it did not separate even after 3 months or more and was extremely stable.

[0055] Further, in 15 parts by weight of ethylene-vinyl acetate copolymer (EVA) powder having a particle size of 200 mesh, 0.1 part by weight of a surfactant composed of sodium dialkyl sulfosuccinate as a dispersant and a microcrosslinked type as a thickener. Add 0.5 parts by weight of polyacrylic acid (manufactured by Nippon Junyaku Co., Ltd., Junron PW-150), add ammonia water with stirring, and hot melt with pH 8.0 and viscosity 720 mPa · s / 25 ° C. Adhesive powder dispersion C was obtained. When the obtained dispersion C was left at room temperature, it did not separate even after 3 months or more and was extremely stable.

Using the hot melt adhesive powder dispersions B and C, respectively, a heat-adhesive skin material and interior material were produced as follows. As the skin material (fiber sheet), a needle punched non-woven fabric made of polyester fiber (with a basis weight of 120 g / m)²)It was used. As shown in FIG. 1, the fiber sheet (3A) is drawn from the roll (15) and is filled with a 2% by weight aqueous dispersion of a fluorocarbon-based water repellent in a treatment tank (16) with a guide roll (17,18,19). ), The fiber sheet (3A) is taken out of the treatment tank (16), and the water repellent content is 0.5 g / m by the drawing roll (20).²Controlled by (solid content). The fiber sheet (3A) was introduced onto a breathable belt conveyor (21) made of a net, felt, etc., and was evacuated from the back side by a suction box (22) abutting on the back surface of the belt conveyor (21). .. A vacuum path (23) with a valve (24) is connected to the suction box (22). In this state, the hot melt adhesive powder dispersions B and C were sprayed from above on the surface of the undried fiber sheet (3A) by the spray device (25). The spray tank (26) of the spray device (25) is filled with the dispersions B and C, and the dispersions B and C are introduced from the pressure pipe (27) while being agitated by the stirrer (28). It is pressurized and sprayed by high pressure air. The hot melt adhesive powder dispersions B and C were sprayed onto the surface of the fiber sheet (3A) as a solid content of 5 g / m.²It was applied in a (dry) amount. At this time, since the fiber sheet (3A) is sucked from the back side by the suction box (22), the hot melt adhesive powder in the dispersions B and C is spray-impacted on the surface of the fiber sheet (3A). It was adsorbed without bouncing and scattering. After spray-coating the dispersions B and C, the fiber sheet (3A) was introduced into a drying chamber (29) and dried by heating at 170 ° C. for 2 minutes. In this way, as shown in FIG. 2, EVA powder is fixed on the fiber sheet (3A) which is a polyester fiber needle punch non-woven fabric, and an adhesive layer (4) scattered in dots on the adhesive surface is formed. A water-repellent heat-adhesive sheet (1) can be obtained. The water-repellent heat-adhesive sheet (1) was cut to a predetermined size by a cutter (30) to form a skin material (3).

[0057] On the other hand, mixed fibers obtained by mixing polyester fibers and polypropylene fibers in a weight ratio of 1: 1 are entangled by needle punching, and then the polypropylene fibers are softened by heat treatment to bind the mixed fibers to a sheet. It was used as a base material for interior materials. As shown in FIG. 3, the obtained interior material base material is used as a cushion layer (2) and heated at 250 ° C. for 30 seconds to soften the polypropylene fibers of the cushion layer (2), and the above-mentioned epidermis is placed on the cushion layer (2). The materials (3) were stacked and set in a cold press device (31) equipped with a lower mold (32) and an upper mold (33). Cold pressing is performed by the cold pressing device (31) to form irregularities on the surface of the cushion layer (2), and at the same time, the skin material (3) is generated by the residual heat obtained by heating and softening the polypropylene fibers of the cushion layer (2). ) Was softened, and the skin material (3) was adhered to the cushion layer (2) via the adhesive layer (4). In this way, the interior material (5) of the trunk room of an automobile in which sharp irregularities were formed as shown in FIG. 4 was manufactured.

[Example 3] When the skin material produced in Example 2 was superposed on the surface of an interior material base material made of thermosetting phenol resin impregnated glass wool and hot-press molded, the adhesiveness of the skin material and the adhesiveness of the skin material were obtained. An interior material having good moldability was obtained. The interior material is useful as a food silencer for an automobile engine room.

[Example 4] Instead of the above-mentioned skin material, a non-woven fabric made of acrylic / polyester (weight: 50 g / m)²), Add 3% by weight of chlorinated paraffin and 2% by weight of antimony oxide as flame retardants to the water repellent water dispersion, and apply 10 g / m of hot melt adhesive powder dispersions B and C.²A water-repellent heat-adhesive sheet was produced in the same manner as in Example 2 except that it was (dried). When the produced water-repellent heat-adhesive sheet was superposed on a thermosetting phenol resin impregnated glass wool and heat-press molded, it was excellent in flame retardancy, water repellency and oil repellency, and the adhesiveness and moldability of the sheet were good. A molded product was obtained.

[Example 5] A heat-adhesive sheet was produced in the same manner as in Example 2 except that a non-woven fabric made of polyester fiber was used and vacuum suction was not performed from the back side. A cloth to which no adhesive was applied was placed on the adhesive-adhesive surface of the manufactured heat-adhesive sheet, and pressed with an iron at a hanging surface of 140 ° C to heat-bond the two. As a result of observing the surface of the heat-adhesive sheet after this heat-bonding, no lumps due to the migration of the hot-melt adhesive were observed on the sheet surface. After that, the obtained bonded sample was subjected to a 180 ° peeling test using a tensile tester, and as a result, the adhesive strength was 1.2 kg / cm.²Met.

[Example 6] 40 parts by weight of polyester copolymer adhesive powder having a particle size of 250 mesh, 1 part by weight of an emulsion of an ethyl acrylate-methacrylic acid copolymer as a thickener, and 0.001 part by weight of a fluorescent dye. Was added, and 2.5 parts by weight of aqueous ammonia was further added with stirring to obtain a hot melt adhesive powder dispersion D having a pH of 8.0 and a viscosity of 620 mPa · s / 25 ° C. When the obtained dispersion D was left at room temperature, it did not separate even after 4 months or more, and was extremely stable.

[0062] In addition, a partially neutralized product of microcrosslinked polyacrylic acid as a thickener in 40 parts by weight of polyester copolymer adhesive powder having a particle size of 250 mesh (manufactured by Nippon Junyaku Co., Ltd., Leosic 250H). 0.1 part by weight and 0.001 part by weight of fluorescent dye were added, and 1.5 parts by weight of aqueous ammonia was further added with stirring to obtain a hot melt adhesive powder dispersion E having a pH of 8.0 and a viscosity of 1500 mPa · s / 25 ° C. .. When the obtained dispersion E was left at room temperature, it did not separate even after 4 months or more and was extremely stable.

[0063] 120 g / m of 1% by weight water dispersion of silicone-based water repellent is applied to the surface of the carpet body made of acrylic / cotton.²Sprayed at the rate of. When the carpet body is undried, the dispersion liquid D or E is applied to the back surface in an amount of 60 g / m.²After spray coating with (drying), it was heat-dried to form a backing material which is a water-repellent heat-bonding sheet in which hot melt adhesives are scattered in dots. On the back surface of the carpet on which the backing material is formed in this way, a non-woven fabric made of polyester fibers (with a basis weight of 15 g / m)²), And heat pressure was applied to produce a carpet laminate having excellent adhesiveness between the non-woven fabric and the carpet body and having water repellency.

[0064] [Effect of the Invention] The water-repellent heat-adhesive sheet of the present invention has excellent heat-adhesiveness, breathability and water repellency, and is used for automobile ceiling materials, door trims, rear parcels, trunk room interior materials, engine room hood silencers, etc. It is useful as a skin material for interior materials, a lining material for a base material for automobile interior materials, and a core material for clothes and the like.

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 is a schematic side view showing a process of manufacturing a water-repellent heat-adhesive sheet (skin material) according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a water-repellent heat-adhesive sheet (skin material) according to an embodiment of the present invention.

FIG. 3 is a schematic side view showing a state in which the water-repellent heat-adhesive sheet (skin material) in FIG. 2 is adhered to an interior material base material (cushion layer).

FIG. 4 is a side sectional view of an interior material according to an embodiment of the present invention.

[Description of sign] 1 Water-repellent heat-adhesive sheet 2 Cushion layer (interior material base material) 3A Fiber sheet 3 Skin material 4 Adhesive layer 5 Interior material