JP2000319615A - Dispersion of hot-melt adhesive powder, thermal adhesive sheet, interior material, thermoformable fiber sheet and carpet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersion in which a hot-melt adhesive powder is difficult to be precipitated by dispersing a hot-melt adhesive powder in water, adding and mixing a slightly crosslinked polyacrylic acid thereto, and then neutralizing the dispersion with addition of an alkali and provide a manufactured article of a uniform quality using the dispersion. SOLUTION: A slightly crosslinked polyacrylic acid can be produced by precipitation polymerization process. As a solvent is used a solvent in which an acrylic acid is dissolved but a polyacrylic acid is not dissolved, namely, an organic solvent such as a benzene or the like. In the solvent, an acrylic acid, a crosslinking agent and a polymerization initiator are mixed and polymerized to precipitate a slightly crosslinked polyacrylic acid in the form of powders. The polyacrylic acid precipitated is dried to form a powder thereof. A hot-melt adhesive powder is usually dispersed in water in an amount of 1-60 wt.% and a slightly crosslinked polyacrylic acid is added to water so that a viscosity of the hot-melt adhesive dispersion finally attains 50-2,000 cps/ 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt adhesive powder dispersion used for attaching a hot-melt adhesive powder to cloth, nonwoven fabric, etc., a heat-adhesive sheet using the same, an interior material, The present invention relates to a thermoformable fiber sheet and a carpet.

[0002]

2. Description of the Related Art For example, a hot-melt adhesive powder is applied to the surface of a cloth or a nonwoven fabric in order to impart thermal adhesiveness to the cloth or the nonwoven fabric. In order to apply the hot melt adhesive powder to cloth or nonwoven fabric, conventionally, a method of applying a dispersion obtained by dispersing the hot melt adhesive powder in water by a mesh roller, or spraying the hot melt adhesive powder is used. And the like.

[0003] However, in the method using a mesh roller, fuzz of a cloth or a non-woven fabric is liable to enter the mesh of the mesh to cause clogging, and in the method of spraying the adhesive powder, the adhesive powder is used for the cloth or the non-woven fabric. However, there is a problem that it is difficult to fix on the surface of the cloth and enters between the naps of the cloth or the non-woven fabric, so that a large thermal adhesiveness cannot be obtained.

[0004] Therefore, the powder of the hot melt adhesive is
A dispersion in which a thickener is dispersed in water has been proposed. Since such a hot-melt adhesive dispersion has a structural viscosity, even if there is fuzz on the surface to be coated, it does not enter between the fuzz and adheres to the surface of the fuzz, and after drying, the surface of the surface to be coated has A state in which the hot melt adhesive powder adheres efficiently can be obtained.

[0005]

In the above-mentioned hot melt adhesive dispersion, the thickener conventionally mainly used is:
It was sodium polyacrylate. However, the sodium polyacrylate has a strong hygroscopic property, and when added to water, it is extremely liable to become a flour, and it takes a long time to uniformly dissolve it in water. Further, since the hot melt adhesive dispersion thickened by the sodium polyacrylate cannot prevent the hot melt adhesive powder from settling, the hot melt adhesive dispersion must be constantly stirred. If the stirring is not sufficient, there is a problem that the hot melt adhesive powder adhering to the surface to be coated becomes non-uniform.

Accordingly, an object of the present invention is to provide a hot melt adhesive powder dispersion in which the hot melt adhesive powder is unlikely to settle, and a product having uniform quality using the same.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a dispersion obtained by dispersing a hot melt adhesive powder in water, wherein the dispersion is a fine cross-linking agent. And a hot-melt adhesive powder dispersion characterized by using polyacrylic acid. In addition,
As used herein, the term "microcrosslinking" refers to crosslinking at such a low density that water solubility is maintained.

In the dispersion, it is preferable to disperse the hot melt adhesive powder in the water, add and mix the finely crosslinked polyacrylic acid, and then neutralize by adding an alkali. The water may be mixed with the finely crosslinked polyacrylic acid, and then neutralized by adding an alkali, and then the powder of the hot melt adhesive may be dispersed, or the hot melt adhesive may be dispersed in the water. The powder of the agent may be dispersed and the dispersion may be made alkaline, and then the finely crosslinked polyacrylic acid may be added and mixed to increase the viscosity. When neutralized with alkali like this,
Although a high viscosity is easily obtained, neutralization with the alkali is not necessarily required.

[0009] In the hot melt adhesive powder dispersion, the dispersion using finely crosslinked polyacrylic acid as a thickener exhibits plastic flow, and the sedimentation of the hot melt adhesive powder is substantially prevented. Therefore, it is not always necessary to stir the hot melt adhesive powder dispersion. In addition, the finely crosslinked polyacrylic acid is not easily turned into a powder when added to and mixed with water, so that it can be relatively easily dispersed and dissolved in water.

[0010] The product obtained by spray-coating or spray-mixing the above-mentioned hot-melt adhesive powder dispersion is one in which the hot-melt adhesive powder is uniformly adhered or mixed, and is uniform in quality. Therefore, the present invention also provides
The present invention provides a heat-adhesive sheet obtained by spray-coating the hot-melt adhesive powder dispersion on one surface of a base sheet and then drying it. The base sheet may be impregnated with a synthetic resin. When the base sheet has air permeability, when the hot melt adhesive powder dispersion is spray-coated on one side of the base sheet, suction is performed from the other side of the base sheet. Is preferred.

The present invention further provides an interior material, wherein the thermal adhesive sheet is used as a skin material, and the skin material is adhered to the surface of an interior material base material, and the hot melt adhesive powder dispersion. After spray-mixing with a fiber, the thermoformable fiber sheet characterized in that the fiber was processed into a sheet shape, a fibrous sheet molded product characterized by molding the thermoformable fiber sheet, and a carpet body. After spray coating the hot melt adhesive powder dispersion on the back,
A carpet characterized by forming a backing material scattered in a dot shape by drying. In the carpet, another sheet may be adhered to the backing material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Hot melt adhesive powder dispersion] The hot melt adhesive used in the present invention is, for example, a polyolefin-based resin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, or the polyolefin-based resin. Modified resin, polyvinyl chloride, polyurethane, polyester, polyester copolymer, polyamide, or a mixture of two or more of polyamide copolymer, etc., the powder of the hot melt adhesive is usually 50 to 300 mesh It is about the size.

The thickener used in the present invention is a slightly crosslinked polyacrylic acid. This finely crosslinked polyacrylic acid can be usually produced by the following precipitation polymerization method. As a solvent, acrylic acid dissolves, but polyacrylic acid does not dissolve, for example, an organic solvent such as benzene, ethyl acetate, cyclohexane, and toluene or a mixture thereof is used. Mix the initiator. Examples of the crosslinking agent include, for example, polyfunctional vinyl monomers such as divinylbenzene, diallyl phthalate, tetraallyloxyethane, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane dimethacrylate,
Sugars such as allyl saccharose can be used. The crosslinking agent is used in an amount of usually 1% or less, preferably around 0.05%, based on acrylic acid.

Examples of the polymerization initiator include benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide, cyclohexanone peroxide, t-butyl peroxide, t-butylperoxybenzoate,
-Butylperoxy-2-ethylhexanate, t-butylperoxypivalate, t-butylperoxyneodecanoate, 3,5,5-trimethylhexanoyl peroxide, diisopropylbenzene hydroperoxide, lauroyl peroxide , Peroxide polymerization initiators such as dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis- 2,
4'-dimethylvaleronitrile, 2,2'-azobis-
2-cyclopropylpropionitrile, 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, 1,1'-azobiscyclohexane-1-carbonitrile, 2-phenylazo-4-methoxy-2 , 4-Dimethylvaleronitrile, 2,2'-azobis-N, N'-
An azo-based polymerization initiator such as dimethyleneisobutyramide can be used.

When acrylic acid is polymerized in a solvent as described above, finely crosslinked polyacrylic acid precipitates in the form of powder. The precipitated polyacrylic acid is dried to a powder. The polyacrylic acid obtained in this manner is crosslinked at such a low density that water solubility is maintained. When the crosslink density of the polyacrylic acid increases, the polyacrylic acid becomes water-swellable and hardly dissolves in water, and when the crosslink density further increases, the polyacrylic acid becomes water-insoluble.

To prepare the hot melt adhesive powder dispersion of the present invention, first, the finely crosslinked polyacrylic acid and the hot melt adhesive powder are added to water and stirred to form a dispersion. preferable. At this stage, the finely crosslinked polyacrylic acid does not increase in viscosity so much and does not easily become a powdered joint, so that it is relatively easy to uniformly disperse it in water. The hot melt adhesive powder need not be added to water at the same time as the finely crosslinked 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 finely crosslinked polyacrylic acid is finally (including the case of neutralization and thickening). The viscosity of the hot melt adhesive dispersion is 50 to 2000 cps /
Add to the water to reach 25 ° C. The finely crosslinked polyacrylic acid added to water as described above dissolves and thickens the water (dispersion), but in order to further increase the viscosity,
Neutralize with alkali. When neutralized with an 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 expands and the water further increases. It can be thickened (or thickened with a small amount).

As the alkali, ammonia and amines such as triethanolamine, diisopropanolamine, aminomethylpropanol, tromethamine and tetrahydroxypropylethylenediamine are preferably used. Examples of the alkali include sodium hydroxide and potassium hydroxide. Can also be used. The amount of the alkali to be added is usually determined with reference to the pH of the dispersion being about 6 to 9.
In addition, a part of the carboxyl groups in the finely crosslinked polyacrylic acid may be converted into a salt in advance by an alkali, but since the degree of neutralization is high, the powder easily disperses into water when dispersed in water. The degree of neutralization needs to be set low enough not to form a flour.

As described above, the hot-melt adhesive powder dispersion using micro-crosslinked polyacrylic acid as a thickener exhibits plastic flow, and the settling of the hot-melt adhesive powder is substantially prevented. .

The hot melt adhesive powder dispersion includes:
For example, higher alcohol sulfate (Na salt or amine salt), alkyl allyl sulfonate (Na salt or amine salt), alkyl naphthalene sulfonate (Na salt or amine salt), alkyl naphthalene sulfonate condensate, alkyl phosphate, dialkyl Sulfosuccinate,
Rosin soap, anionic surfactant such as fatty acid salt (Na salt or amine salt), polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether,
Nonionic surfactants such as polyoxyethylene alkyl ester, polyoxyethylene alkyl amide, sorbitan alkyl ester, polyoxyethylene sorbitan alkyl ester, octadecylamine acetate, imidazoline derivative acetate, polyalkylene polyamine derivative or salt thereof, octadecyltrimethylammonium chloride One or more surfactants such as cationic surfactants such as trimethylaminoethylalkylamide halogenide, alkylpyridinium sulfate and alkyltrimethylammonium halide may be added as a dispersant.

The above-mentioned hot melt adhesive powder dispersion further contains, for example, alkali metal salts such as sodium, potassium and lithium such as polyacrylic acid, polymethacrylic acid and alginic acid, and water-soluble synthetic polymers such as polyethylene oxide. , Trollooi, gluten, below mallow, Noritsugi and other water-soluble natural polymers such as water-soluble natural polymers composed of vegetable mucilage; polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, Vinyl chloride resin, vinylidene chloride resin, styrene resin, vinyl acetate resin, fluorine resin, thermoplastic acrylic resin, thermoplastic polyester,
Thermosetting resin such as thermoplastic polyamide, thermoplastic urethane resin, epoxy resin, melamine resin, urea resin, phenol resin, resorcin resin, alkylresorcin resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile- Synthetic resin emulsion such as butadiene-styrene copolymer; 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 copolymer, styrene-rubber Powders of synthetic rubbers or elastomers such as block copolymers such as intermediate block-styrene copolymers or emulsions thereof may be added. If necessary, fillers such as calcium carbonate, talc, gypsum, silica, carbon black, wood powder, walnut powder, coconut powder, starch, etc., pigments, dyes, flame retardants, flame retardants, insect repellents, preservatives, aging An inhibitor, an ultraviolet absorber, a fluorescent dye, a surfactant, a foaming agent, or a softener such as paraffin, wax, or silicone, a water repellent, an oil repellent, a release agent, or a plasticizer may be added.

In the case where the dispersion obtained by dispersing the hot-melt adhesive powder in water is made alkaline by the third component or by an alkali added separately, the finely-crosslinked dispersion is added to the dispersion. By adding and mixing the polyacrylic acid of the type, the viscosity can be increased to a high degree without further adding an alkali.

As a method for applying the hot-melt adhesive powder dispersion to the surface to be coated, a method in which high pressure is directly applied to the dispersion and the dispersion is air-sprayed is preferable. According to this method, even when the viscosity of the hot melt adhesive powder dispersion is high, the dispersion can be spray-applied efficiently. At this time, the hot melt adhesive powder dispersion does not necessarily need to be stirred, but may be. The coating amount is usually 1 to 100 g / m ² as solid content. The hot melt adhesive powder dispersion may be prepared in advance at a high concentration, and may be diluted with water to a desired concentration before use.

Since the hot melt adhesive powder dispersion spray-coated as described above has a structural viscosity, even if the surface to be coated has fuzz, it does not enter between the fuzz.
The burrs adhere to the surface, and after drying, a state is obtained in which the hot melt adhesive powder efficiently adheres to the surface of the surface to be coated.
Further, since the hot melt adhesive powder dispersion is applied without settling, the hot melt adhesive powder can uniformly adhere to the surface to be coated.

[Heat-adhesive sheet] The heat-adhesive sheet of the present invention is obtained by spray-coating the above-mentioned hot-melt adhesive powder dispersion on one surface of a substrate sheet and then drying. As described above, the hot melt adhesive powder efficiently and uniformly adheres to the surface of such a heat adhesive sheet. In the heat adhesive sheet,
Since the bonding pressure is applied pointwise, it works effectively and uniformly, and when the substrate sheet has air permeability, the air permeability is not hindered.

Examples of the base sheet include synthetic fibers such as polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, acrylic fiber, urethane fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber and acetate fiber, pulp, cotton, and the like. Recycling obtained by defibrating natural fibers such as wool, palm fiber, hemp fiber, bamboo fiber, etc., glass fibers, carbon fibers, ceramic fibers, inorganic fibers such as asbestos, or fiber products using these fibers. A knitted or nonwoven fabric composed of one or more fibers such as fibers, or an open cell sheet or a porous sheet of a plastic such as polyurethane, polyethylene, polypropylene, polyamide, polyester, or polyvinyl chloride can be used. .

The base sheet may be, for example, polyethylene, polypropylene, ethylene-propylene copolymer,
Ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, fluororesin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, acrylonitrile-butadiene copolymer, Thermoplastic synthetic resin such as styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer and / or urethane resin, melamine resin, thermosetting acrylic resin, urea resin,
A thermosetting synthetic resin such as a phenol resin, a resorcin resin, an alkyl resorcin resin, an epoxy resin, and a thermosetting polyester may be impregnated.

When the base material sheet is impregnated with the synthetic resin in this manner, the softened material of the hot melt adhesive applied to the back surface of the base material sheet in a point-like manner due to the sealing effect of the synthetic resin during the pressure bonding. It does not migrate to the surface of the substrate sheet. Therefore, the surface of the heat-adhesive sheet, for example, the surface of the skin material, is free from bumps due to the transfer of the hot melt adhesive, and the appearance is improved. Further, the synthetic resin impregnated in the base sheet increases the rigidity of the base sheet, and improves the dimensional stability of the base sheet against changes in temperature and humidity.

The amount of impregnation of the synthetic resin is usually ^{2 to} 500 g / m ^2.
And In order to impregnate the base sheet with the synthetic resin, the base sheet is immersed in a solution or emulsion of the synthetic resin, or the solution or emulsion is applied to one or both sides of the base sheet by a spray gun, a roll coater, a knife coater or the like. Apply and then dry. A foaming agent may be added to the synthetic resin solution or emulsion. When a thermosetting synthetic resin is impregnated as the synthetic resin, the thermosetting synthetic resin may be cured by heating at the time of the drying.

The base sheet may be coated or impregnated with a fluorine-based or silicone-based water repellent, an oil repellent, a flame retardant, a flame retardant, an ultraviolet absorber, or the like.

The amount of the hot melt adhesive powder dispersion applied by spraying is usually 1 to 100 g / m ² as a solid content.
When the base material sheet has air permeability,
It is preferable to suction from the surface of the substrate sheet opposite to the surface to which the dispersion is applied. Such suction prevents splashing of the hot-melt adhesive powder due to impact at the time of spraying, so that the hot-melt adhesive powder can be reliably adsorbed to the surface of the base sheet.

After the dispersion is spray-coated as described above, the substrate sheet is dried by heating. The conditions for the heating and drying are a temperature equal to or higher than the melting point of the hot melt adhesive used, and are generally 70 ° C. or higher and about 1 to 10 minutes. When the thermosetting synthetic resin is impregnated in the base sheet, the thermosetting synthetic resin may be cured at the time of the heating and drying.

The heat-adhesive sheet of the present invention obtained as described above can be used as a skin material of an automobile interior material, a backing material of a base material of an automobile interior material, or a core material of clothes or the like. .

[Interior Material] The interior material of the present invention comprises the above-mentioned heat-adhesive sheet as a skin material, and the skin material is adhered to the surface of the interior material base material. When the heat-adhesive sheet is used as a skin material, the base sheet is made of artificial leather, leather, fiber knitted fabric, nonwoven fabric, or polyurethane foam, polyethylene foam, polypropylene foam, polystyrene foam, poly It is preferable to use a laminate with a plastic foam such as a vinyl chloride foam.

As the interior material base material, for example, polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, aramid fiber, acrylic fiber, urethane fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber,
Synthetic fiber such as acetate fiber, rayon, cupra, etc., wood fiber such as pulp, wood chip, natural fiber such as cotton, wool, silk, hemp, kenaf fiber, coconut fiber, glass fiber, asbestos, ceramic fiber, carbon fiber, metal fiber, etc. Inorganic fibers, or mixed fibers of two or more of the above fibers, or recycled fibers obtained by defibrating scraps of products using the above fibers, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate Copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, fluororesin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer Polymer, acrylonitrile-butadiene-styrene copolymer Thermoplastic synthetic resin or urethane resin etc., melamine resins, thermosetting acrylic resins, urea resins,
Thermosetting synthetic resins such as phenolic resin, resorcinol resin, alkyl resorcinol resin, epoxy resin, thermosetting polyester, urethane resin prepolymer, epoxy resin prepolymer, melamine resin prepolymer, urea resin prepolymer, phenol resin prepolymer A fiber sheet bonded with a synthetic resin precursor such as a polymer, a diallyl phthalate prepolymer, an acrylic oligomer, a polyvalent isocyanate, a prepolymer such as a methacrylic ester monomer or a diallyl phthalate monomer, an oligomer, a monomer, etc. Needle punch felt bound by punching, synthetic resin impregnated felt obtained by impregnating the above synthetic resin and / or synthetic resin precursor into the needle punch felt, melting point 200
℃ or less polyethylene fiber, polypropylene fiber, polyester fiber, thermoplastic fiber, polyurethane fiber, polystyrene, thermoplastic fiber bonded by needle punching and / or heat setting if desired by mixing one or more kinds of low melting fiber such as polyamide fiber. A synthetic resin foam sheet such as polyvinyl chloride, a fiber-reinforced synthetic resin foam sheet in which the above fibers are mixed as reinforcing fibers, and a synthetic resin obtained by impregnating the above synthetic resin and / or synthetic resin precursor into the above synthetic resin foam sheet Examples include an impregnated synthetic resin foam sheet, cardboard or waste paper impregnated with the synthetic resin and / or synthetic resin precursor, and a laminated base material in which two or more of the above base materials are laminated. A foaming agent may be added to the synthetic resin or the synthetic resin precursor used for the interior material base material. The interior material base material is provided with moldability by a synthetic resin or a synthetic resin precursor or a low-melting fiber used as a binder or an impregnating agent.

In the interior material base material, it is desirable to impregnate a porous material with an initial condensate of the thermosetting synthetic resin. Further, the porous material impregnated with the initial condensate is dried by heating and drying. It is desirable to slightly condense the initial condensate to be in the B state. By setting the initial condensate impregnated in the porous material to the B state, the hardening time of the initial condensate can be shortened, and the hot pressing for a short time provides good moldability to the interior material base material. In addition to being able to be provided, 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 excellent in shape retention and heat resistance can be obtained.

As the initial condensate of the thermosetting synthetic resin, it is preferable to use a phenolic initial condensate which is an initial condensate of a monohydric phenol and / or a polyhydric phenol with an aldehyde. And / or condensation of the polyhydric phenol with the aldehyde is carried out with ammonia and / or
Alternatively, the reaction is preferably performed in the presence of an amine, and the phenolic precondensate is preferably sulfomethylated and / or sulfimethylated.

Examples of the porous material include fiber aggregates such as nonwoven fabrics, felts, knitted fabrics, and laminates thereof; polyurethane foams having open cells, polyolefin foams such as polyethylene and polypropylene, and polyvinyl chloride foams. There are plastic foams having a continuous foaming structure such as polystyrene foam, amino resin foam such as melamine resin and urea resin, and phenol resin foam; sintered bodies of plastic beads.

In order to adhere the skin material to the interior material base material, the hot melt adhesive powder adhered and formed on the back surface of the skin material is heated and softened, and then the two are bonded together. When molding the interior material base material into a desired shape, the molding of the interior material base material is performed before bonding the skin material, simultaneously with bonding the skin material, or after bonding the skin material. It may be performed at any time. As a molding method, when the interior material base material contains a thermoplastic synthetic resin or low melting point fiber, the interior material base material is usually heated to soften the thermoplastic synthetic resin or low melting point fiber. The method of cold press forming after the, or the method of vacuum forming is applied when the skin material is impermeable, and when the interior material base material contains a thermosetting synthetic resin, Usually, a method of hot-press molding the interior material base material is applied.

In the case where the above-mentioned skin material has air permeability and is molded after bonding the skin material to the interior material base material, the air contained in the interior material base material or the interior material base material may be removed. The gas (for example, formalin gas in the case of phenolic resin, or water or carbon dioxide gas in the case of polyvalent isocyanate) contained in the synthetic resin contained in the hot-melt adhesive powder (softened product) at the time of molding. Since the gas passes through the gap and is smoothly discharged from the skin material to the outside, a puncture phenomenon does not occur in the manufactured interior material, and the problem of odor due to residual gas is eliminated.

The interior material of the present invention can be used in various applications, and is suitable as, for example, an interior material for a trunk room of an automobile or an interior material for a dashboard. In the interior material, the adhesive layer of the hot-melt adhesive powder is scattered in a dot-like manner, so that the rigidity of the adhesive layer does not affect the molding shape of the interior material or the uneven shape of the surface. The molded shape and the uneven shape of are sharply molded. When the skin material is breathable, the adhesive layer also has breathability, so that the obtained interior material has excellent soundproofing.

[Thermoformable Fiber Sheet and Molded Fiber Sheet] The thermoformable fiber sheet of the present invention is obtained by spray-mixing the hot-melt adhesive powder dispersion of the present invention with the fiber, and then forming the fiber into a sheet. It is obtained by processing
The fiber sheet molded product of the present invention is obtained by molding the thermoformable fiber sheet.

As the fibers, the same fibers as those constituting the base sheet in the above-mentioned heat-adhesive sheet can be used, and are usually mixed with a hot melt adhesive powder dispersion as a floc. The mixing amount of the dispersion with respect to the fibers is preferably about 5 to 40% by weight. Since the hot melt adhesive powder dispersion is mixed with the fibers by spraying, the hot melt adhesive powder in the dispersion is easily mixed uniformly with the fibers. If the fibers are agitated when spraying the dispersion, the uniformity can be further improved.

The fiber obtained by mixing the above-mentioned dispersion liquid is made into a card web by, for example, a carding machine, and a plurality of the card webs are laminated to form a fleece. The fleece is needle punched if desired, and is then usually heat treated.
The heat treatment is performed by hot air heating or the like by a ventilation dryer, so as to soften the hot melt adhesive powder in the dispersion and bind the fibers to each other.

The raw fiber sheet produced in this manner is cut into a desired size, heated at a temperature not lower than the softening point of the hot melt adhesive, and then cold pressed to obtain a fiber sheet molded product. Can be. When a non-breathable film is laminated on the fiber sheet, vacuum forming can be applied.

The obtained fiber sheet molded product is used as a ceiling material, a door trim, a rear parcel, a trunk room interior material of a car, a heat insulating material of a building, a door face material and the like. In the present invention, since the hot-melt adhesive powder dispersion is sprayed and mixed with the fibers, the hot-melt adhesive powder is easily mixed uniformly with the fibers, and therefore, the thermoformable fiber sheet having uniform physical properties, and further the fibers A sheet formation is obtained.

[Carpet] The carpet of the present invention is obtained by spray-coating the hot-melt adhesive powder dispersion of the present invention on the back of the carpet body and then drying to form dotted backing material. It is. The type of carpet in the present invention is not particularly limited, and may be a tufted carpet in which a pile portion is formed by tufting a pile yarn on a base fabric, or needle punching from one or both sides of a fiber layer. And a needle punch carpet in which fibers are entangled and / or raised.

The carpet body according to the present invention includes, for example, polyester fiber, polyethylene fiber, polypropylene fiber, polyamide fiber, acrylic fiber, urethane fiber,
Synthetic fibers such as polyvinyl chloride fiber, polyvinylidene chloride fiber and acetate fiber, natural fibers such as pulp, cotton, silk, wool, palm fiber, hemp fiber, kenaf fiber, bamboo fiber, glass fiber, carbon fiber, ceramic fiber, It is constituted by one or more kinds of fibers such as inorganic fibers such as asbestos or regenerated fibers obtained by defibrating scraps of fiber products using these fibers.

In the present invention, the hot melt adhesive powder dispersion is spray-coated on the back surface of the carpet body. According to this spray coating, a required amount of backing material can be applied and formed on the back surface of the carpet body more efficiently than when using a device such as a roll coater or a knife coater, and the cost of raw materials can be reduced. Can be.

The spray coating amount of the hot melt adhesive powder dispersion is usually from ² to 500 g / m ² as solid content.
When this dispersion is spray-coated on the back surface of the carpet body, it is preferable to suck the carpet body from the front side. Since the dispersion liquid of the present invention applied in this manner has structural viscosity, even if there is fuzz on the surface to be coated, it does not enter between the fuzz but adheres to the fuzz surface. Therefore,
After drying, the hot melt adhesive powder efficiently adheres to the surface to be coated, and a point-like scattered state is obtained.

After the hot-melt adhesive powder dispersion is spray-coated on the back surface of the carpet body, the carpet body is dried. Drying is preferably performed under heating at a temperature equal to or higher than the melting point of the hot melt adhesive applied to the carpet body, usually at 70 ° C. or higher for about 1 to 10 minutes. By this drying, the thermoplastic resin applied to the carpet body becomes a backing material for the obtained carpet.

[0052] In the carpet thus manufactured, the backing material is scattered and formed in dots, so that the carpet is excellent in air permeability. In particular, when the carpet is used as a floor carpet for a vehicle,
Demonstrate excellent sound absorption.

In the carpet of the present invention, another sheet may be further adhered to the backing material formed on the back surface of the carpet body. Other sheet types can be appropriately selected according to the purpose of use of the carpet,
For example, 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, cupra, woody materials such as pulp and wood chips Fiber sheet made of natural fiber such as fiber, cotton, wool, silk, hemp, kenaf fiber, coconut fiber, or inorganic fiber such as glass fiber, asbestos, ceramic fiber, carbon fiber, metal fiber, or two or more of the above fibers Fiber sheet made of mixed fiber of the above, or recycled fiber obtained by defibrating scrap of a product using the above fiber, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride , Polyvinylidene chloride, polystyrene, polyvinyl acetate, Thermoplastic resins such as acrylic resin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, Thermosetting synthetic resin such as urethane resin, melamine resin, thermosetting acrylic resin, urea resin, phenol resin, resorcin resin, alkylresorcin resin, epoxy resin, thermosetting polyester, or urethane resin prepolymer, epoxy resin Prepolymer, melamine resin prepolymer, urea resin prepolymer, phenol resin prepolymer, diallyl phthalate prepolymer,
A fiber sheet bonded with a synthetic resin precursor such as an acrylic oligomer, a polyvalent isocyanate, a methacrylic ester monomer, a diallyl phthalate monomer, or a prepolymer, an oligomer, or a monomer, and a needle punch obtained by bonding a card web of the fiber by needle punching. Felt, needle punch felt, synthetic resin and / or
Alternatively, a synthetic resin impregnated fiber sheet impregnated with a synthetic resin precursor, and the above fibers mixed with one or more low-melting fibers such as polyethylene fibers, polypropylene fibers, polyester fibers, and polyamide fibers having a melting point of 200 ° C. or less, If possible, a synthetic resin foam sheet of thermoplastic felt, polyurethane, polystyrene, polyvinyl chloride, or the like bound by needle punching and / or heat setting, a fiber-reinforced synthetic resin foam sheet in which the above fibers are mixed as reinforcing fibers, A synthetic resin impregnated synthetic resin foam sheet in which a resin and / or a synthetic resin precursor is impregnated in the synthetic resin foam sheet, cardboard or waste paper impregnated with the synthetic resin and / or the synthetic resin precursor, or the fibrous sheet. There is a laminated fiber sheet in which two or more types are laminated. Synthetic resin or synthetic resin precursor used for the fiber sheet,
A blowing agent may be added.

The above-mentioned bonding may be carried out by heating the carpet from the back side to soften the backing material, overlapping another sheet on the back side of the carpet, and pressing the carpet. Particularly when the carpet of the present invention is used as a floor carpet for a vehicle, a felt, a silencer composed of a foam sheet or the like is set in a lower mold of a press mold, and after softening a backing material of the carpet, It is introduced into the press mold and subjected to press molding. By such press molding, the carpet and the silencer can be formed into a shape conforming to the floor shape of the vehicle, and at the same time, the carpet and the silencer can be bonded.

Further, in this case, the backing material is softened by heating the carpet from the back side, or the hot-melt adhesive powder dispersion is spray-coated on the back side of the carpet body, and then immediately dried without drying. A floor carpet may be formed by stacking a silencer on the side, pressing and heating and drying to form a raw floor carpet material, cutting the raw material into predetermined dimensions, and thermoforming. The thermoforming is usually carried out by heating the raw cut material and performing cold press forming, or by hot pressing the raw cut material.

[0056]

EXAMPLES Hereinafter, the present invention will be described more specifically 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 throughout water in water, the dispersion was stirred and finely crosslinked polyacrylic acid (Nippon Pure Chemical Co., Ltd.)
Manufactured by Junron PW-110) as a thickener a.
After stirring to make the mixture uniform, aqueous ammonia was added to increase the viscosity. Table 1 shows the mixing ratio of each component. The resulting hot melt adhesive powder dispersions A1 to A4 were placed in a 200 cc glass bottle, allowed to stand at room temperature for 2 months, and the storage stability of the dispersions A1 to A4 was examined. Table 1 shows the results.

[0058]

[Table 1] ◎… No abnormalities such as separation ○… Slightly separated at the top

Comparative Example 1 Hot melt adhesive powder dispersions A5 to A8 were prepared in the same manner as in Example 1 except that the above-mentioned thickener a and aqueous ammonia were not used, and the storage stability was examined. Table 2 shows the mixing ratio of each component and the results of the storage stability.

[0060]

[Table 2]

Comparative Example 2 Hot melt adhesive powder dispersions A9 to A12 were produced in the same manner as in Example 1 except that 0.5% sodium polyacrylate was used instead of the thickener a and the aqueous ammonia. , And the storage stability was examined. Table 3 shows the mixing ratios of the components and the results of storage stability.

[0062]

[Table 3]

As is clear from Example 1 and Comparative Examples 1 and 2, simply increasing the viscosity of the hot melt adhesive powder dispersion does not improve the standing stability, and uses finely crosslinked polyacrylic acid. As a result, the storage stability for the first time is dramatically improved.

Example 2 15 parts by weight of ethylene-vinyl acetate copolymer (EVA) powder having a particle size of 200 mesh and
0.1 parts by weight of a surfactant comprising sodium dialkyl sulfosuccinate as a dispersant and finely crosslinked polyacrylic acid (Junron PW-
150) 0.5 part by weight was added, and ammonia water was further added with stirring to obtain a hot melt adhesive powder dispersion B having a pH of 8.0 and a viscosity of 720 cp / 25 ° C. When the obtained dispersion B was allowed to stand at room temperature, it did not separate even after 3 months or more, and was extremely stable.

Using the hot melt adhesive powder dispersion B, a heat-adhesive skin material and interior material were produced as follows. As the skin material (base sheet), needle-punched non-woven fabric made of polyester fiber (basis weight 120 g / m ² )
It was used.

As shown in FIG. 1, the skin material 3 is pulled out from the roll 15 and introduced on a permeable belt conveyor 16 made of a net, felt, etc., and a suction box 17 abutting on the back of the belt conveyor 16. Vacuum sucked from behind. A vacuum path 18 with a valve 19 communicates with the suction box 17. In this state, the hot melt adhesive powder dispersion B was sprayed from above onto the surface of the skin material 3 by the spray device 20. The dispersion B is filled in a spray tank 21 of the spray device 20, and the dispersion B is pressurized by high-pressure air introduced from a pressure pipe 22 and sprayed while being stirred by a stirrer 23.

The hot melt adhesive powder dispersion B was
The spray was applied to the surface of the skin material 3 in an amount of 5 g / m ² (dry) as a solid content. At this time, since the skin material 3 is sucked from the back side by the suction box 17, the hot melt adhesive powder in the dispersion B is adsorbed on the surface of the skin material 3 without splashing and scattering due to spray impact. Was.

After the dispersion B was applied by spraying, the skin material 3 was introduced into a drying chamber 24 and dried by heating at 150 ° C. for 2 minutes. In this way, as shown in FIG. 2, the EVA powder was fixed on the skin material 3 which was a polyester fiber needle punched non-woven fabric, and the adhesive layer 4 scattered in a dotted manner on the bonding surface was formed. The skin material 3 was cut to a predetermined size by a cutter 25.

On the other hand, mixed fibers obtained by mixing polyester fibers and polypropylene fibers at a weight ratio of 1: 1 are entangled by a needle punch, and then the polypropylene fibers are softened by a heat treatment to bind the mixed fibers. The sheet (interior material base material) was used. As shown in FIG. 3, the obtained fiber sheet was used as a cushion layer 2 and heated at 250 ° C. for 30 seconds to soften the polypropylene fibers of the cushion layer 2. It was set on a cold press device 26 having a mold 27 and an upper mold 28.

A cold press is performed by the cold press device 26 to form irregularities on the surface of the cushion layer 2.
The adhesive layer 4 of the skin material 3 is softened by residual heat obtained by heating and softening the polypropylene fibers of the cushion layer 2,
The skin material 3 was bonded to the cushion layer 2 via the adhesive layer 4. In this way, the interior material 1 for a trunk room of an automobile having sharp irregularities as shown in FIG. 4 was manufactured.

Example 3 The surface material produced in Example 2 was overlaid on the surface of an interior material substrate made of glass wool impregnated with a thermosetting phenolic resin, and hot-pressed. An interior material having good moldability was obtained.

Example 4 Instead of the above-mentioned skin material, a non-woven fabric (basis weight 50 g / m ² ) made of flame-retardant, water- and oil-repellent acrylic / polyester was used, and a hot melt adhesive powder dispersion B was used. Except that the application amount of 10 g / m ² (dry)
A heat-adhesive sheet was produced in the same manner as in Example 2. When the produced heat-adhesive sheet was placed on a thermosetting phenolic resin-impregnated glass wool and subjected to hot-press molding, it was excellent in flame retardancy, water repellency and oil repellency, and a molded article having good adhesiveness and moldability of the sheet. was gotten.

Example 5 A nonwoven fabric made of polyester fiber was immersed in a 50% by weight aqueous solution of an alkylresorcin resin, and then heated and dried at 100 ° C. for 5 minutes to obtain a base sheet.
The resin impregnation rate of the base sheet was 20 g / m ² as a solid content. A heat-adhesive sheet was produced in the same manner as in Example 2 except that the obtained base sheet was used in place of the above-mentioned skin material, and vacuum suction from the back side was not performed.

[0074] A cloth to which no adhesive was applied was placed on the adhesive-adhered surface of the manufactured heat-adhesive sheet.
The two were pressed with an iron and heat bonded. As a result of observing the surface of the heat-adhesive sheet after this heat bonding, no bumps were observed on the sheet surface due to the transfer of the hot melt adhesive. Thereafter, the obtained laminated sample was subjected to a 180 ° peel test using a tensile tester, and as a result, the adhesive strength was 1.2 kg / cm 2.

Example 6 The hot melt adhesive powder dispersion A-2 produced in Example 1 was stirred in a mixer while the cotton-like material of the regenerated fiber obtained by defibrating the scrap of the fiber product was stirred. Was sprayed. The dispersion A-2 was spray-mixed in such an amount that the mixing ratio of the polyamide adhesive powder to the regenerated fibers was 15% by weight. The regenerated fiber obtained by mixing the dispersion A-2 in this manner was made into a card web by a carding machine, and 10 layers of the web were laminated to form a fleece.
The obtained fleece was pressed between iron plates heated to 220 ° C. for 1 minute to soften the polyamide adhesive powder in the fleece,
The regenerated fibers were bound together. The obtained raw material was cut into a predetermined size, heated at 200 ° C., and then cold-pressed at a pressure of 3 kg / cm ² to obtain a base material for an automobile ceiling material.

Example 7 A partially neutralized product of finely crosslinked polyacrylic acid as a thickener was added to 40 parts by weight of a polyester copolymer adhesive powder having a particle size of 250 mesh (Nippon Pure Chemical Co., Ltd.)
0.1% by weight and fluorescent dye 0.00
One part by weight was added, and 1.5 parts by weight of aqueous ammonia was further added with stirring to obtain a hot melt adhesive powder dispersion C having a pH of 8.0 and a viscosity of 1500 cp / 25 ° C. When the obtained dispersion C was allowed to stand at room temperature, it did not separate even after 4 months or more, and was extremely stable.

The dispersion C was spray-coated on the back surface of the carpet body made of acrylic / cotton at a coating amount of 60 g / m ² (dry), and then heated and dried to form a dotted backing material. A non-woven fabric made of polyester fiber (basis weight 15 g / m ² ) was stacked on the back of the carpet on which the backing material had been formed, and heated and pressed, and a carpet laminate having excellent adhesion between the non-woven fabric and the carpet body was obtained. The thing was manufactured.

[0078]

In the hot melt adhesive powder dispersion of the present invention, the hot melt adhesive powder hardly settles. The heat-adhesive sheet, thermoformable fiber sheet, carpet obtained by spray-coating and mixing the hot melt adhesive powder dispersion, and the interior material and fiber sheet molded product using the same have uniform quality. .

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a process for manufacturing a heat-adhesive sheet (skin material) according to an embodiment of the present invention.

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

FIG. 3 is a schematic side view showing a state where the 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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Interior material 2 ... Cushion layer (Interior material base material) 3 ... Skin material (Base material sheet) 4 ... Adhesive layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kunori Ito 5 213 Nahobata-cho, Tokai City, Aichi Prefecture 5 Nagoya Yuka Co., Ltd. F-term (reference) 3B120 CA04 DB02 4J004 AA06 AA07 AA09 AA10 AA15 AA16 AB03 CA02 CA03 CA04 CA05 CA06 CA07 CB01 CC02 GA01 4J040 DF011 JA03 JA09 JB01 JB11 KA25 MA10 MB02 NA11 NA12 PB03

Claims (12)

[Claims] 1. A hot melt adhesive comprising a dispersion of a powder of a hot melt adhesive in water, wherein a finely crosslinked polyacrylic acid is used as a thickener of the dispersion. Powder dispersion. 2. The powder of the hot melt adhesive is dispersed in the water, and the finely crosslinked polyacrylic acid is added and mixed, and then neutralized by adding an alkali.
A hot melt adhesive powder dispersion as described in the above. 3. The water is mixed with the finely crosslinked polyacrylic acid and then neutralized by adding an alkali.
2. The hot melt adhesive powder dispersion according to claim 1, wherein the hot melt adhesive powder is dispersed. 4. The hot melt according to claim 1, wherein said hot melt adhesive powder is dispersed in said water, said dispersion is made alkaline, and said finely crosslinked polyacrylic acid is added and mixed to thicken said hot melt adhesive. Melt adhesive powder dispersion. 5. A heat-adhesive sheet obtained by spray-coating the hot-melt adhesive powder dispersion according to claim 1 on one surface of a substrate sheet, followed by drying. . 6. The heat-adhesive sheet according to claim 5, wherein the base sheet is impregnated with a synthetic resin. 7. The base sheet having air permeability, and the other side of the base sheet is spray-coated with the hot melt adhesive powder dispersion on one side of the base sheet. The heat-adhesive sheet according to claim 5, which is sucked from the sheet. 8. An interior material, characterized in that the thermal adhesive sheet according to claim 5 is used as a skin material, and the skin material is adhered to the surface of the interior material base material. 9. A thermoformable fiber sheet obtained by spray-mixing the hot-melt adhesive powder dispersion according to any one of claims 1 to 4 to a fiber and processing the fiber into a sheet. 10. A fiber sheet molded product obtained by molding the thermoformable fiber sheet according to claim 9. 11. A hot-melt adhesive powder dispersion according to any one of claims 1 to 4, which is spray-coated on the back surface of the carpet body, followed by drying to form a dotted backing material. And carpet. 12. The carpet according to claim 11, wherein another sheet is adhered to the backing material.