CN1849422A - Flame-retardant fiber sheet and its molding - Google Patents

Abstract

The invention aims to provide a fiber sheet with excellent flame retardance and a molded product thereof. Provided is a flame-retardant fiber sheet wherein fibers contain expanded graphite. The expanded graphite expands when exposed to high temperatures, thereby imparting self-extinguishing properties to the fibrous sheet. The molded product of the flame-retardant fiber sheet has high flame retardancy and is harmless to humans and animals, and therefore, it can be used for interior materials of automobiles and buildings, for example.

Description

Flame-retardant fiber sheet and its molding

technical field

The present invention relates to a flame-retardant fiber sheet and its molding used for interior materials of automobiles and buildings.

Background technique

In the past, as such a fiber sheet, a needle-punched non-woven fabric or a needle-punched felt obtained by intertwining a fiber web by a needle punching method, and a resin non-woven fabric obtained by bonding a fiber web by a synthetic resin are provided. Cloth, resin felt, braided fabric of fibers, etc. (see, for example, JP-A-11-61616 and JP-A-8-39596).

Such fibers are required to have flame retardancy in addition to soundproofing and heat insulating properties. Conventionally, flame retardants such as tetrachlorophthalic acid, tetrabromophthalic acid, tetrabromobisphenol A, antimony trioxide, and chlorinated paraffin are contained in the fiber sheet in order to impart flame retardancy to the fiber sheet.

However, even if the above-mentioned flame retardant is used, the flame retardancy of the fiber sheet is not sufficient, and there is also a problem that the flame retardant generates toxicity.

Contents of the invention

As means for solving the above-mentioned problems, the present invention provides a flame-retardant fiber sheet containing expanded graphite in fibers.

The fiber is preferably a hollow fiber or a hollow fiber is mixed therein, more preferably a low melting point fiber having a melting point of 180° C. or less is mixed in the fiber.

)。When molding the fiber sheet, the fibers are preferably bonded with a synthetic resin adhesive. In this case, it is preferable that the synthetic resin binder is an aqueous solution, and the expanded graphite is dispersed in the aqueous solution to be impregnated into the fiber sheet, and a water-soluble resin is preferably dissolved in the aqueous solution. And, it is preferable that the synthetic resin binder is a phenolic resin, and has undergone sulfomethylation and/or sulfinylmethylation (sulfimecil

).

The present invention further provides a molded product obtained by molding the above-mentioned flame-retardant fiber sheet into a predetermined shape. The airflow resistance of the molded product is preferably 0.1 to 100 kPa·s/m.

Furthermore, the present invention provides a laminate in which other fiber sheets are laminated on one or both sides of the above-mentioned flame-retardant fiber sheet via a porous thermoplastic film, and a molded product in which the laminate is molded into a predetermined shape. . The airflow resistance of the molded product is preferably 0.1 to 100 kPa·s/m.

When the flame-retardant fiber sheet of the present invention is exposed to high temperature, the expanded graphite contained therein expands to impart self-extinguishing properties to the fiber sheet. When the fibers are hollow fibers or hollow fibers are mixed therein, the rigidity of the fiber sheet increases. Also, if low-melting-point fibers having a melting point of 180°C or less are mixed in the fibers, or the fibers are bonded by a synthetic resin binder, the fibrous sheet can obtain formability. Usually, the synthetic resin binder is an aqueous solution, and the expanded graphite is dispersed in the aqueous solution and impregnated in the fiber sheet. If a water-soluble resin is dissolved in the aqueous solution, the aqueous solution can be thickened to prevent expansion of the graphite. Precipitate and improve the adhesion of expanded graphite to fibers. Furthermore, this water-soluble resin also serves as a mold release agent, and can improve the mold release property of the molded product when the flame-retardant fiber sheet is press-molded.

The fiber sheet of the invention has high flame retardancy and is harmless to humans and animals.

Description of drawings

FIG. 1 is an explanatory diagram showing the principle of measurement of ventilation resistance.

Detailed ways

The present invention will be described in detail below.

[fiber]

Examples of fibers used in the present invention include synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polyurethane fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, acetate fibers, wool, mohair, cashmere, Natural fibers such as camel hair, alpaca hair, vicuña hair, angora goat hair, silk, red silk cotton, broadleaf cattail fiber (ガマ繊维), pulp, cotton, coconut fiber, hemp fiber, bamboo fiber, kenaf fiber, Rayon (rayon, chemical staple fiber), high wet modulus viscose fiber, cupro fiber, acetate, triacetate and other cellulosic rayon, glass fiber, carbon fiber, ceramic fiber, asbestos fiber, etc. Inorganic fibers, regenerated fibers obtained by carding scraps of fiber products using these fibers, and the like. These fibers may be used alone or in combination of two or more.

More preferred fibers are hollow fibers.

The hollow fiber is made of polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate, poly-1,4-dimethylcyclohexane terephthalate Polyesters such as esters, nylon 6, nylon 66, nylon 46, nylon 10 and other polyamides, polyethylene, polypropylene and other polyolefins, acrylic, polyurethane, polyvinyl chloride, polyvinylidene chloride, acetate and other thermoplastic resins composition. These hollow fibers may be used alone or in combination of two or more.

The hollow fiber is produced by a known method such as melt spinning or preferential elution of one of the components in the fiber obtained by composite spinning two types of polymers.

The hollow fiber has one, two or more hollow tubes with circular or elliptical cross sections, and the hollow ratio is 5% to 70%, preferably 10% to 50%. The hollow ratio is the ratio of the cross-sectional area of the hollow tube to the cross-sectional area of the fiber.

In addition, the fineness of the hollow fiber is in the range of 1 dtex to 50 dtex, preferably in the range of 2 dtex to 20 dtex.

When the above-mentioned hollow fiber is used in combination with other fibers, the above-mentioned hollow fiber is preferably mixed in an amount of 30% by mass or more.

When the above hollow fiber is used, the rigidity of the fiber sheet is enhanced by the effect of the hollow tube.

Furthermore, low-melting fibers having a melting point of 180°C or less can also be used in the present invention. Examples of such low-melting fibers include polyolefin fibers such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer, polyvinyl chloride fibers, polyurethane fibers, polyester fibers, and polyester copolymers. Textile fibers, polyamide fibers, polyamide copolymer fibers, etc. These low melting point fibers may be used alone or in combination of two or more.

The fineness range of the low melting point fiber is 0.1dtex-60dtex.

The above-mentioned low-melting-point fiber is usually mixed with the above-mentioned fiber at a ratio of 1 to 50% by mass.

[expanded graphite]

The expanded graphite used in the present invention is obtained by immersing natural graphite in a mixed solution such as sulfuric acid and nitric acid, and adding an oxidizing agent such as hydrogen peroxide or hydrochloric acid. The expansion start temperature is about 150°C to 300°C, and the expansion volume is About 30~300ml/g, the particle size is about 300~30 mesh.

When adding expanded graphite to the fiber sheet, the expanded graphite can be dispersed in a synthetic resin binder (latex, latex, etc.) and added together with the synthetic resin binder. In addition, after the fiber sheet is impregnated with synthetic resin, In addition, sodium polyacrylate, polyacrylate partially saponified, polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose in which expanded graphite is prepared; and acrylate and/or Copolymers of methacrylate and acrylic acid and/or methacrylic acid, or emulsions and aqueous solutions of alkali-soluble resins such as slightly crosslinked products of the copolymers, and fiber sheets are coated and impregnated with these latexes and aqueous solutions.

For the dispersion of expanded graphite in synthetic resin, latex, or aqueous solution, it is preferable to use a homogenizer, ultrasonic emulsification device, or the like.

When using a supersonic emulsification device, the expanded graphite is refined and evenly dispersed in the aqueous solution and latex. If the synthetic resin binder uniformly dispersed with expanded graphite is impregnated in the fiber sheet, the expanded graphite will easily penetrate into the fiber sheet, thereby improving the flame retardancy of the fiber sheet.

[Thermally expandable granules]

In the present invention, heat-expandable granules may be added to the fiber sheet during use. The heat-expandable particulate body is composed of, for example, a thermoplastic resin having a low softening point and a low-boiling point solvent. As a thermoplastic resin with a low softening point, for example: methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethyl acrylate Hexyl ester, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, methacrylic acid Aliphatic or cyclic acrylates such as isobutyl, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, stearyl methacrylate, lauryl methacrylate, etc. and/or methacrylate, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether Other vinyl (base) ethers, styrene, α-methylstyrene and other styrenes, acrylonitrile, methacrylonitrile and other nitrile monomers, vinyl acetate and vinyl propionate and other fatty acid vinyl esters, vinyl chloride , vinylidene chloride, vinylidene fluoride, vinylidene fluoride and other halogen-containing monomers, ethylene, propylene and other olefins, isoprene, chloroprene, butadiene and other dienes, acrylic acid, methacrylic acid, itaconic Acid, maleic acid, crotonic acid, atropic acid, citric acid and other α, β-unsaturated carboxylic acids, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate Ester, 2-hydroxypropyl acrylate, allyl alcohol and other hydroxyl-containing monomers, acrylamide, methacrylamide, diacetone acrylamide and other amides, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate Ester, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate and other amino-containing monomers, glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether and other epoxy-containing monomers body, and water-soluble monomers such as vinylpyrrolidone, vinylpyridine, vinylcarbazole, and the above-mentioned γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriacetoxysilane, p-trimethoxysilylstyrene, p-triethoxysilylstyrene, p-trimethoxysilyl-α-methylstyrene, p-triethoxysilyl-α-methylbenzene Ethylene, γ-(acryloyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-β(N-vinylbenzylaminoethyl-γ-aminopropyl)trimethoxysilane One, two or more polymers of hydrolyzable silyl group-containing vinyl monomers such as hydrochloride, or polymers of the above polymers coated with polyacrylic acid esters such as divinylbenzene and diethylene glycol diacrylate Or methacrylate, diallyl phthalate, allyl glycidyl ether and other cross-linked polymers, polyamides with low softening points, polyesters with low softening points, etc., preferably have a softening temperature of 180°C or below point of thermoplastic resin. As a low boiling point solvent, such as: n-hexane, cyclohexane, n-pentane, isopentane, n-butane, isobutane, n-heptane, n-octane, isooctane, gasoline, ether, acetone, benzene, etc. Organic solvents with a boiling point of 150°C or less. And the heat-expandable granules are composed of expandable beads impregnated with the above-mentioned low-boiling-point solvent in the above-mentioned thermoplastic resin granules, and microcapsules filled with the above-mentioned low-boiling-point solvent in the shell of the above-mentioned low-softening-point thermoplastic resin. The diameter of the granules is usually 0.5 to 1000 μm.

As the heat-expandable particles used in the present invention, there are heat-expandable inorganic particles such as vermiculite, perlite, and natural glassy hollow microspheres.

[fiber sheet]

The fibrous sheet of the present invention is produced by the following method: utilizing the method of intertwining fiber webs or fiber mats by needle punching; or by impregnating or mixing low melting point fibers or synthetic resin binders in fiber webs or fiber mats Bonding, or intertwining fiber webs or fiber mats by needle punching and then impregnating synthetic resin adhesives for bonding; and methods of weaving fibers, etc.

The above-mentioned expanded graphite or heat-expandable particles are usually mixed in the fiber before the fiber is made into a sheet or mat, but when the sheet or mat is impregnated or mixed with a synthetic resin binder, it may also be mixed with the synthetic resin binder. middle. The mixing ratio may be arbitrary, but usually 0.5 to 50% by mass of the expanded graphite is added to the fibers. When using the heat-expandable granules, 0.1 to 50% by mass of the granules are added.

After impregnating or mixing the synthetic resin solution into the sheeted fibers, the sheeted fibers are dried. When the synthetic resin binder contained in the sheet-like fiber is a thermosetting resin, it can be stored for a long time if the resin is brought into the B state, and it can be molded at low temperature for a short time.

[synthetic resin adhesive]

As a synthetic resin used as a binder for the above fibers, 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 polyurethane resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-benzene Thermoplastic synthetic resins such as ethylene copolymer, ethylene-propylene copolymer, ethylene-propylene terpolymer, ethylene-vinyl acetate copolymer, polyurethane resin, melamine resin, thermosetting acrylic resin, urea resin, phenol resin, cyclo Thermosetting synthetic resins such as epoxy resins and thermosetting polyesters, etc., polyurethane resin prepolymers, epoxy resin prepolymers, melamine resin prepolymers, urea resin prepolymers, phenolic resins, etc. Synthesis of prepolymers, diallyl phthalate prepolymers, acrylic oligomers, polyisocyanates, methacrylate monomers, diallyl phthalate monomers, etc. prepolymers, oligomers, monomers, etc. Resin precursor. The aforementioned synthetic resins may be used alone or in combination of two or more, and are usually used as latex, latex, aqueous solution, organic solvent, or the like.

When the above-mentioned synthetic resin adhesive is an aqueous solution, it is preferable to dissolve a water-soluble resin in the aqueous solution in advance. As the above-mentioned water-soluble resin, for example: sodium polyacrylate, partially saponified polyacrylate, polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, etc., and can also be used : Alkali-soluble resins such as copolymers of acrylates and/or methacrylates and acrylic acid and/or methacrylic acid, or slightly cross-linked products of the copolymers. The aforementioned copolymers or slightly crosslinked copolymers are usually supplied as latexes.

If the above-mentioned water-soluble resin is added and dissolved in the above-mentioned synthetic resin aqueous solution, the expanded graphite dispersed in the aqueous solution is not easy to precipitate due to its thickening effect or dispersion effect, thereby obtaining a uniform impregnation solution. Moreover, the water-soluble resin can enhance the adhesion of the expanded graphite to the fiber, and effectively prevent the expanded graphite from detaching from the fiber sheet.

The above-mentioned water-soluble resin is usually used in the above-mentioned aqueous solution in an amount of about 0.1 to 20% by mass in terms of solid content.

When impregnating the above-mentioned sheet-formed fibers with a synthetic resin, the sheet-formed fibers are usually impregnated in a liquid synthetic resin or a synthetic resin solution, or the sheet-formed fibers are sprayed, scraped, roll-coated, flow-coated, etc. Apply liquid synthetic resin or synthetic resin solution.

To adjust the amount of synthetic resin in the synthetic resin-impregnated or mixed sheet-like fibers, the sheet-like fibers are squeezed using squeeze rolls or pressure plates after the synthetic resin has been impregnated or mixed. At this time, although the thickness of the sheet-formed fiber is reduced, the rigidity is high when the hollow fiber is contained in the sheet-formed fiber, and the thickness is elastically restored after extrusion, thereby maintaining a certain thickness. In particular, when the sheeted fibers contain low-melting fibers, it is preferable to sheet the fibers in advance, heat to melt the low-melting fibers, and bond the fibers with the melt. In this way, the strength and rigidity of the fibrous sheet are further improved, the handleability at the time of synthetic resin impregnation is also improved, and the recovery of the thickness after extrusion is also remarkable.

As described above, when the fiber of the present invention contains hollow fibers and is formed into a sheet, the sheet becomes highly rigid, and the content of the synthetic resin binder in the sheeted fiber can be made smaller than that of a sheet without the hollow fiber. The content of synthetic resin binder in the fiber.

When the synthetic resin binder is an aqueous synthetic resin latex, it is preferable to add expanded graphite to the aqueous synthetic resin latex and apply ultrasonic waves to disperse it. In this case, the wavelength of the ultrasonic waves is preferably 10 to 700 kHz. When ultrasonic waves are applied, the expanded graphite can be miniaturized so that it can be impregnated into the fiber sheet.

The synthetic resin binder used in the present invention is preferably a phenolic resin. The phenolic resin used in the present invention will be described in detail below.

Phenolic resins are obtained by condensing phenolic compounds with aldehydes and/or aldehyde donors. To make it water-soluble, the phenolic resin may also be sulfomethylated and/or sulfinylmethylated.

The phenolic resin of the present invention is impregnated into the sheet base material in the form of an aqueous solution of an initial condensate (initial condensate liquid). The initial condensate liquid can also use the following water-soluble organic solvents as required: methanol, ethanol, isopropanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-butanol, Amyl alcohol, isoamyl alcohol, n-hexanol, methyl amyl alcohol, 2-ethyl butanol, n-heptanol, n-octanol, trimethylnonanol, cyclohexanol, benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, pine Aromatic alcohol, diacetone alcohol and other alcohols; acetone, methyl acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, diethyl ketone, di-n-propyl Dimethyl ketone, diisobutyl ketone, acetonyl acetone, dimethyl ether, cyclohexanone, methylcyclohexanone, acetophenone, camphor and other ketones; ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1 , 3-propylene glycol, polyethylene glycol and other glycols; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether and other glycols Ethers; esters of the above glycols such as ethylene glycol diacetate and diethylene glycol monoethyl ether acetate or their derivatives; ethers such as 1,4 dioxane, diethyl cellosolve agent, diethyl carbitol, ethyl lactate, isopropyl lactate, diethylene glycol diacetate, dimethylformamide, etc.

[phenolic compounds]

As the phenolic compound used in the above-mentioned phenolic resin, it can be monohydric phenol or polyhydric phenol, or a mixture of monohydric phenol and polyhydric phenol. However, when only monohydric phenol is used, formaldehyde is easily released during and after curing. Preference is therefore given to using polyphenols or mixtures of monohydric and polyhydric phenols.

[Monohydric phenol]

Examples of the monohydric phenol include: phenol, o-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol, xylenol, 3,5-xylenol, butylphenol, t-butylphenol Alkyl phenol, nonyl phenol, o-fluorophenol, m-fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, o-iodophenol , m-iodophenol, p-iodophenol, o-aminophenol, m-aminophenol, p-aminophenol, o-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-dinitrophenol, 2,4, Monohydric phenol substitutes such as 6-trinitrophenol; polycyclic monohydric phenols such as naphthol, etc. These monohydric phenols can be used alone or in combination of two or more kinds.

[Polyphenols]

Examples of the polyhydric phenol include: resorcinol, alkylresorcinol, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, poroglucinol, bisphenol , Dihydroxynaphthalene, etc. These polyphenols may be used alone or in combination of two or more. Among these polyhydric phenols, resorcinol or alkylresorcinol is preferable, and alkylresorcinol which reacts with aldehyde faster than resorcinol is particularly preferable.

Examples of alkyl resorcinol include: 5-methylresorcinol, 5-ethylresorcinol, 5-propylresorcinol, 5-n-butylresorcinol, 4, 5-dimethylresorcinol, 2,5-dimethylresorcinol, 4,5-diethylresorcinol, 2,5-diethylresorcinol, 4,5- Dipropylresorcinol, 2,5-dipropylresorcinol, 4-methyl-5-ethylresorcinol, 2-methyl-5-ethylresorcinol, 2- Methyl-5-propylresorcinol, 2,4,5-trimethylresorcinol, 2,4,5-triethylresorcinol, etc.

The polyphenol mixture obtained by dry distillation of kerogen shale produced in Estonia is inexpensive, and contains a large amount of various highly reactive alkyl resorcinols other than 5-methylresorcinol, so it is an effective method of the present invention. Especially preferred polyphenol raw materials.

In the present invention, the above-mentioned phenolic compound is condensed with an aldehyde and/or an aldehyde donor (aldehyde). The above-mentioned aldehyde donor refers to a compound that generates an aldehyde when decomposed, or a mixture thereof. Examples of such aldehydes include formaldehyde, acetaldehyde, propionaldehyde, chloral, furfural, glyoxal, n-butyraldehyde, hexanal, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, phenylacetaldehyde, As for o-tolualdehyde, salicylaldehyde, etc., as an aldehyde donor, paraformaldehyde, trioxane, hexamethylenetetramine, tetraoxymethylene, etc. can be illustrated, for example.

As described above, in order to improve the stability of the water-soluble phenolic resin, it is preferable to subject the above-mentioned phenolic resin to sulfomethylation and/or sulfinylmethylation treatment.

[Sulfomethylating agent]

Examples of sulfomethylating agents that can be used to improve the stability of water-soluble phenolic resins include mixing sulfurous acid, acid sulfurous acid or metaacid sulfurous acid with alkali metals or trimethylamine and benzyltrimethyl Ammonium and other quaternary amines or water-soluble sulfites obtained by reacting quaternary ammonium, and aldehyde adducts obtained by reacting these water-soluble sulfites with aldehydes.

The aldehyde adducts are formaldehyde, acetaldehyde, propionaldehyde, chloral, furfural, glyoxal, n-butyraldehyde, hexanal, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, phenylacetaldehyde, o-toluene Formaldehyde, salicylaldehyde and other aldehydes are obtained by addition reaction with the above-mentioned water-soluble sulfurous acid, for example, the aldehyde adduct formed by formaldehyde and sulfite is hydroxymethanesulfonate.

[sulfinyl methylating agent]

Examples of sulfinyl methylating agents that can be used to improve the stability of water-soluble phenolic resins include alkali metal sulfoxylates of aliphatic and aromatic aldehydes such as sodium formaldehyde sulfoxylate (Diaobai powder) and benzaldehyde sodium sulfoxylate. Sulfates; bisulfites (dithionites) of alkali metals and alkaline earth metals such as sodium bisulfite and magnesium bisulfite; hydroxyalkane sulfinates such as hydroxymethanesulfinate, etc.

When producing the above-mentioned phenolic resins, the following basic substances can be mixed as catalysts or pH adjusters according to their needs, for example: hydrochloric acid, sulfuric acid, orthophosphoric acid, boric acid, oxalic acid, formic acid, acetic acid, butyric acid, benzenesulfonate Acids, inorganic or organic acids such as phenolsulfonic acid, p-toluenesulfonic acid, naphthalene-α-sulfonic acid, naphthalene-β-sulfonic acid, esters of organic acids such as dimethyl oxalate, maleic anhydride, phthalic anhydride Acid anhydrides such as ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium oxalate, ammonium acetate, ammonium phosphate, ammonium thiocyanate, ammonium iminosulfonate and other ammonium salts, monochloroacetic acid or its sodium salt, α, α'-di Organic halides such as chloropropanol, hydrochlorides of amines such as triethanolamine hydrochloride and aniline hydrochloride, urea adducts such as salicylic acid urea adducts, stearic acid urea adducts, heptanoic acid urea adducts, etc. substances, N-trimethyltaurine, zinc chloride, ferric chloride and other acidic substances, ammonia, amines, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and other alkali metals and alkaline earth metal hydrogen Oxides of alkaline earth metals such as oxides and lime, weak acid salts of alkali metals such as sodium carbonate, sodium sulfite, sodium acetate, and sodium phosphate, etc.

(manufacture of phenolic resin)

The above-mentioned phenolic resin (initial condensate) can be produced according to the usual method, specifically, it can be produced by the following method: (a) a method of condensing a monohydric phenol and/or a polyhydric phenol with an aldehyde, (b) a method of condensing a monohydric phenol The initial condensate obtained by condensation of phenol and aldehydes and/or the initial condensate obtained by condensation of polyphenols and aldehydes is condensed with monohydric phenol and/or polyhydric phenol, (c) making monohydric phenol and polyhydric phenol and Initial condensate obtained by condensing aldehydes, method of condensing monohydric phenol and/or polyphenol A method of condensing an initial condensate, (e) condensing an initial condensate obtained by condensing a monohydric phenol and an aldehyde and/or an initial condensate obtained by condensing a polyhydric phenol and an aldehyde, and condensing a monohydric phenol, a polyhydric phenol, and an aldehyde A method of condensing the obtained initial condensate, etc.

Preferred phenolic resins in the present invention are phenol-alkylresorcinol cocondensates. The aqueous solution of the above-mentioned phenol-alkylresorcinol cocondensate (initial condensate) has good stability, and has the advantage that it can be stored for a long time under normal temperature conditions compared with the condensate (initial condensate) formed only by phenol . In addition, the fibrous sheet obtained by impregnating the aqueous solution into the sheet base material and pre-curing has good stability, and the fibrous sheet does not lose its moldability even if it is stored for a long period of time. In addition, because of the high reactivity of alkyl resorcinol with aldehydes, free aldehydes are captured and reacted, so the amount of free aldehydes in the resin is reduced. A preferred method for producing the above-mentioned phenol-alkylresorcinol cocondensate is to first react phenol and aldehyde to produce a phenolic resin initial condensate, and then add an alkylresorcinol to the phenolic resin initial condensate. Phenols, if desired, and methods of adding aldehydes and allowing them to react.

For example, in the above (a) condensation of monohydric phenols and/or polyhydric phenols and aldehydes, usually 0.2 to 3 moles of aldehydes are added to 1 mole of monohydric phenols, and 0.1 to 0.8 moles of aldehydes are added to 1 mole of polyhydric phenols. class, and add a solvent and a third component as required, and heat and react for 8 to 20 hours at a liquid temperature of 55 to 100°C. At this time, the aldehydes can be added at the beginning of the reaction, or added in portions or continuously dropwise.

When the initial condensate of the above-mentioned phenolic resin is subjected to sulfomethylation and/or sulfinic acid methylation, a sulfomethylating agent and/or sulfinyl group may be added to the initial condensate at any stage. Methylating agent, so as to carry out sulfomethylation and/or sulfinyl methylation of phenolic compound and/or initial condensate.

The addition of the sulfomethylating agent and/or the sulfinylmethylating agent can be performed at any stage before, during, or after the condensation reaction.

The total addition amount of the sulfomethylating agent and/or the sulfomethylating agent is usually 0.001 mol to 1.5 mol with respect to 1 mol of the phenolic compound. When the total addition amount is 0.001 mol or less, the hydrophilicity of the phenolic resin is insufficient, and when it is 1.5 mol or more, the water resistance of the phenolic resin becomes poor. In order to keep properties such as the curability of the initial condensate produced and the physical properties of the cured resin well, it is preferably about 0.01 to 0.8 mol.

The sulfomethylating agent and/or sulfinyl methylating agent added for sulfomethylation and/or sulfinyl methylation of the initial condensate and the methylol and /or the aromatic ring of the initial condensate reacts to introduce a sulfomethyl group and/or a sulfinylmethyl group into the initial condensate.

In this way, the aqueous solution of the initial condensate of sulfomethylated and/or sulfinated phenolic resin is stable in a wide range of acidity (pH1.0) to alkalinity, even in acidic, neutral and All ranges of alkalinity are curable. Especially when it is acidic, it is cured, and the remaining methylol groups are reduced, so there is no worry about the formation of formaldehyde due to the decomposition of the cured product.

In the present invention, as the above-mentioned phenolic resin, if necessary, urea, thiourea, melamine, thiomelamine, dicyandiamide, guanidine, guanamine, methylguanamine, benzoguanamine, 2, The 6-diamino-1,3-diamine amine resin monomer and/or the initial condensate formed by the amine resin monomer are co-condensed with the phenolic compound and/or the initial condensate.

In addition, aldehydes and/or aldehyde donors, or curing agents such as hydroxyalkylated triazone derivatives may be further added to the phenolic resin initial condensate (including initial cocondensate) of the present invention.

As the above-mentioned aldehyde and/or aldehyde donor, the same aldehyde and/or aldehyde donor used in the manufacture of the initial condensate (initial cocondensate) of phenolic resin can be used, and the hydroxyalkylated triazone derivative Compounds can be obtained by reaction between urea compounds, amines and aldehydes and/or aldehyde donors. Examples of the above-mentioned urea compounds used in the production of hydroxyalkylated triazone derivatives include urea, thiourea, alkyl urea such as methyl urea, alkyl thiourea such as methyl thiourea, and phenyl urea. , naphthyl urea, halogenated phenyl urea, and nitroalkyl urea, etc. alone or as a mixture of two or more. Particularly preferred urea compounds are urea or thiourea. As amines, except aliphatic amines such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, pentylamine, benzylamine, furfurylamine, ethanolamine, ethylenediamine, hexamethylenediamine, hexamethylenetetramine In addition to the amines, ammonia can also be exemplified, and these can be used alone or as a mixture of two or more. The aldehyde and/or aldehyde donor used in the production of the hydroxyalkylated triazone derivative is the same as the aldehyde and/or aldehyde donor used in the production of the initial condensate of the phenolic resin.

When synthesizing the above-mentioned hydroxyalkylated triazone derivatives, usually according to 1 mole of urea compounds, amines and/or ammonia are 0.1-1.2 moles, and aldehydes and/or aldehyde donors are used in a ratio of 1.5-4.0 moles. its reaction. When carrying out the above reaction, the order of addition of these substances is arbitrary, but as a preferred reaction method, the required amount of aldehyde and/or aldehyde donor is first charged into the reactor, usually while maintaining a temperature of 60° C. or below While slowly adding the required amount of amines and/or ammonia, and then adding the required amount of urea compounds, and heating and stirring at 80-90°C for 2-3 hours to react. As the aldehyde and/or aldehyde donor, 37% formalin is usually used, but in order to increase the concentration of the reaction product, a part of it may be replaced with paraformaldehyde. In addition, when hexamethylenetetramine is used, a reaction product having a higher solid content can be obtained. The reaction between urea compounds, amines and/or ammonia and aldehydes and/or aldehyde donors is usually carried out in aqueous solution, but methanol, ethanol, isopropanol, n-butanol, ethylene glycol, diethylene glycol can also be used One or two or more mixtures of alcohols to replace part or all of water, and one or two water-soluble organic solvents such as ketones such as acetone and methyl ethyl ketone can also be added. a mixture of one or more species. The amount of the curing agent added is 10 to 100 parts by mass relative to 100 parts by mass of the initial condensate (initial cocondensate) of the phenolic resin of the present invention in the case of aldehydes and aldehyde donors. In the case of an alkylated triazone derivative, the amount is 10 to 500 parts by mass relative to 100 parts by mass of the initial condensation product (initial cocondensation product) of the above-mentioned phenolic resin.

In the synthetic resin binder used in the present invention, also can add mixed calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, calcium sulfite, calcium phosphate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, Magnesium oxide, titanium oxide, iron oxide, zinc oxide, aluminum oxide, silicon dioxide, diatomaceous earth, dolomite, gypsum, talc, clay, asbestos, mica, calcium silicate, bentonite, silica, carbon black, Iron powder, aluminum powder, glass powder, stone powder, blast furnace slag, fly ash, cement, zirconia and other inorganic fillers; natural rubber or its derivatives; styrene-butadiene rubber, acrylonitrile-butadiene rubber, neoprene Polyvinyl alcohol, sodium alginate, starch, starch derivatives, bone glue, gelatin, blood powder, methyl cellulose, Carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylate, polyacrylamide and other water-soluble polymers and natural rubber; calcium carbonate, talc, gypsum, carbon black, wood flour, walnut powder, coconut shell flour, wheat flour , rice flour and other fillers; surfactants; higher fatty acids such as stearic acid and palmitic acid, higher alcohols such as palmitic alcohol and stearyl alcohol; fatty acid esters such as butyl stearate and glyceryl monostearate; fatty acid amides; Brazilian coconut wax and other natural waxes and synthetic waxes; paraffin wax, paraffin oil, silicone oil, silicone resin, fluororesin, polyvinyl alcohol, grease and other mold release agents; azodicarbonamide, dinitro Organic foaming agents such as pentamethylenetetramine, P, P'-oxobisbenzenesulfonyl hydrazide, azobisisobutyronitrile (Azobis-2,2'-(2-Mecholgropionitril)); carbonic acid Sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate and other inorganic foaming agents; natural glassy hollow microspheres, perlite, glass balls, foamed glass, hollow ceramics and other hollow particles; expanded polyethylene, expanded polystyrene , expanded polypropylene and other plastic foams or foamed particles; pigments, dyes, antioxidants, antistatic agents, crystallization accelerators, phosphorus compounds, nitrogen compounds, sulfur compounds, boron compounds, bromine compounds , guanidine compounds, phosphate compounds, phosphate ester compounds, amine resins and other flame retardants, fire retardants, water repellents, oil repellents, insect repellents, preservatives, waxes, lubricants, antiaging agents, ultraviolet rays Absorbent; DOP, DBP, phthalate plasticizers such as dicyclohexyl phthalate, and other plasticizers such as tricresyl phosphate, etc.

The fibrous sheet of the present invention is formed into a flat plate or a predetermined shape, and is generally suitable for thermocompression molding. When the above-mentioned fibrous sheet contains thermally expandable particles, the thermal expansion of the thermally expandable particles is restricted during the above-mentioned press molding. The thickness of the fibrous sheet is carried out side by side. When the fibrous sheet is heated to an expansion temperature or higher of the thermally expandable particulates contained therein while limiting the thickness, the thermally expandable particulates expand. As described above, since the thickness of the fiber sheet is limited, the expansion of the particles compresses the surrounding fibers, thereby increasing the density of the fiber portion and increasing the rigidity. However, the porosity of the fiber sheet as a whole does not change, so the weight also does not change. After the fibrous sheet of the present invention is formed into a flat plate by thermocompression, it can also be formed into a predetermined shape by thermocompression, and when it contains low-melting fiber or thermoplastic resin binder, it can also be heated to make the low-melting fiber or thermoplastic resin After the adhesive is softened, it is formed into a specified shape by cold pressing. The fibrous sheet of the present invention can also be used by stacking several sheets.

The fiber sheet material of the present invention can be used, for example, as roof materials for automobiles, instrument panel sound-absorbing materials, hood sound-absorbing materials, engine lower cover sound-absorbing materials, cylinder cover sound-absorbing materials, shock-absorbing and sound-absorbing materials, carpets, instrument panels, car doors, etc. Base materials for interior materials such as trim strips, reinforcing materials or sound-absorbing materials laminated on the base materials, heat insulating materials, building materials, etc.

The airflow resistance of the molded article obtained from the fibrous sheet of the present invention is preferably 0.1 to 100 kPa·s/m.

Among them, the ventilation resistance R (Pa.s/m) is a scale indicating the degree of ventilation of the air-permeable material. The measurement of the ventilation resistance R is carried out by a steady flow differential pressure measurement method. As shown in Fig. 1, a test piece T is placed in a cylindrical air passage W, and the pressure in the air passage W on the starting point side of the arrow in the figure is measured under a constant air flow V (direction of the arrow in the figure). The pressure difference between P1 and the end point P2 of the arrow in the figure, and then the ventilation resistance R can be calculated according to the following formula.

(Formula) R＝ΔP/V

Among them, ΔP (=P1-P2): pressure difference (Pa), V: ventilation volume per unit area (m ³ /m ² .s), and ventilation resistance R (Pa·s/m) and ventilation degree C (m /Pa·s) has a relationship of C=1/R.

Ventilation resistance can be measured, for example, with an air permeability tester (product name: KES-F8-AP1, manufactured by Kato-tech Co., Ltd., steady flow differential pressure measurement method).

Molded products with ventilation resistance in the range of 0.1 to 100kPa·s/m have good sound absorption.

Furthermore, this fiber sheet may be laminated with other materials such as a skin material, a lining material, and a core material.

A laminate may be formed by laminating other fibrous sheets on one or both sides of the fibrous sheet of the present invention via a porous thermoplastic film.

The porous thermoplastic film is made of, for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer and other polyolefin resins (including modified polyolefin resins), polychlorinated A film composed of one, two or more mixtures of ethylene, polyurethane, polyester, polyester copolymer, polyamide, polyamide copolymer, etc.

The above-mentioned laminate is obtained, for example, by laminating a thermoplastic film extruded from a mold T on a flame-retardant fiber sheet, and then laminating other fiber sheets on the fiber sheet and subjecting it to thermocompression molding. .

The above-mentioned porous thermoplastic film may also be pre-set as a porous film, and after the film is laminated on the flame-retardant fiber sheet, holes may be opened by needles or the like, but the fiber sheet is, for example, squeezed from the mold T The heat-softened thermoplastic film is laminated, and once extruded, fine pores are formed on the film. The pores are formed by fluff on the surface of the fiber sheet. In this method, the step of making the film porous is unnecessary, and the fine pores have a good influence on the sound absorption of the product.

The airflow resistance of the laminate obtained by molding the above laminate into a predetermined shape is preferably 0.1 to 100 kPa·s/m. Molded products with ventilation resistance in the range of 0.1 to 100kPa·s/m have excellent sound absorption.

Hereinafter, the present invention will be described in detail through examples. However, the present invention is not limited to the examples shown below.

[Example 1]

A fiber web composed of 80 mass% polyester fibers (denier: 12dtex, fiber length: 52mm) and 20 mass% low-melting polyester fibers (softening point: 110°C, denier: 8dtex, fiber length: 54mm) , and made into a sheet-like fiber (weight per unit area: 500 g/m ² , thickness: 15 mm) by a needle punching method. 20 parts by mass of expanded graphite (expansion start temperature: 300° C. to 320° C., expansion ratio: 100 times) was added and mixed to 80 parts by mass of phenol-formaldehyde initial condensate (50% by mass solid content) to prepare an impregnating solution. The viscosity of this immersion liquid is 100 mPa·s. Using this impregnating liquid, impregnate it into the above-mentioned sheet-like fibers so that the solid content becomes 50% by mass, and then dry the sheet at a temperature of 100 to 120°C for 3 minutes while pumping air in a drying chamber to precure the sheet. Fiber sheet is made by materializing fiber. The precured fiber sheet was thermocompressed at a temperature of 200° C. for 60 seconds to obtain a molded product with a thickness of 10 mm. Air permeability tester (product name: KES-F8-AP1, manufactured by Kato-tech Co., Ltd., V=4×10 ^-2 (m/s)) was used to measure the air resistance of the molded product (the same applies to Example 2 and later). . The ventilation resistance of this molding was 3.5 kPa·s/m.

[Example 2]

Add and mix 60 mass parts of phenol-formaldehyde initial condensation products (50% mass solid content), 20 mass parts of polyvinyl alcohol (10 mass parts solid content, degree of saponification: 98.5mol%) and 20 mass parts of expanded graphite (expanded Start temperature: 300°C to 320°C, expansion rate: 100 times) to prepare the impregnation solution. The viscosity of this dipping solution is 250 mPa·s. Except using this impregnating liquid instead of the impregnating liquid in Example 1, the compression molding was carried out in the same manner as in Example 1 to obtain a 10 mm thick molded article, and the ventilation resistance of this molded article was 4.1 kPa·s/m.

[Example 3]

Add and mix 60 mass parts of phenol-formaldehyde initial condensate (50% mass solid content), 15 mass parts polyvinyl alcohol (10 mass mass solid content, degree of saponification: 98.5mol%), 4 mass parts of polyvinyl alcohol as an alkali-soluble The post-crosslinked copolymer latex of ethyl acrylate and methacrylic acid of the adhesive is PRIMAL, ASE-60 (manufactured by Rohm and Haas, trade name), 20 parts by mass of expanded graphite (expansion start temperature: 300°C to 320°C , Expansion rate: 130 times) and 1 mass part of 27% by mass ammonia water to prepare an immersion solution. The viscosity of this immersion liquid is 950 mPa·s. Except using this impregnating liquid instead of the impregnating liquid in Example 1, press molding was carried out in the same manner as in Example 1 to obtain a 10 mm thick molded article, and the air resistance of this molded article was 4.6 kPa·s/m.

[Comparative example 1]

In addition to using phosphorus-containing and nitrogen-based flame retardants to replace the expanded graphite in Example 1, impregnation, pre-curing and compression molding are performed in the same manner as in Example 1 to obtain a 10mm thick molding. The ventilation resistance of this molding It is 3.3kPa·s/m.

The above-mentioned Examples 1, 2, 3 and Comparative Example 1 were tested for the stability of the impregnation solution and the flame retardancy of the molded product, and the results are shown in Table 1.

flame retardant

UL94: Based on the UL94 standard, the length is 125mm and the thickness is 10mm.

FMVSS-302: According to the FMVSS-302 method, the length is 350mm, the width is 100mm, and the thickness is 10mm.

Stability of impregnation solution

Investigate the stability of the immersion solution left at room temperature. Evaluation criteria are as follows.

⊚: A stable and uniform solution even if left standing for 7 days or more.

◯: The expanded graphite starts to separate after 2 to 3 days.

×: 10 to 20 minutes after the preparation of the immersion liquid, the expanded graphite precipitated and separated.

Table 1 flame retardant Stability of impregnation solution UL94 FMVSS-302 Example 1 V-0 non-combustible x Example 2 V-0 non-combustible ○ Example 3 V-0 non-combustible ◎ Example 4 unqualified non-combustible ◎

[Example 4]

Use 50% by mass of hollow polyester fiber (hollow ratio: 20%, fineness: 7dtex, fiber length: 60mm), 20% by mass of vinylon fiber (fineness: 12dtex, fiber length: 45mm) and 30% by mass of hemp A fiber web composed of fibers (denier: 20dtex, fiber length: 40mm), and a sheet-like fiber (weight per unit area: 450g/m ² , thickness: 15mm) was prepared by needle punching. Add 50 parts by mass of phenol-alkylresorcinol-formaldehyde initial cocondensate (50% by mass solid content), 17 parts by mass of carboxymethylcellulose (1 mass% solid content), 5 parts by mass of PRIMAL, ASE-60, 27 parts by mass of expanded graphite (expansion start temperature: 300°C, expansion rate: 150 times) and 1 part by mass of 27% by mass ammonia water used in the embodiment 3 of the tackifier to obtain a viscosity 2000mPa·s impregnating liquid, the impregnating liquid is impregnated in the above-mentioned sheet fiber so that the solid content reaches 40% by mass, and then dried at 100°C for 3 minutes in a drying chamber to pre-cure the impregnated fiber. Sheeting of fibers to produce fiber sheets. This precured fiber sheet was heat press-molded at a temperature of 220° C. for 60 seconds to obtain a molded product with a thickness of 10 mm. The flame retardancy of this molding is V-0 in the UL94 standard. In addition, there is no precipitation of expanded graphite in the immersion liquid, and the workability is excellent. The ventilation resistance of this molding was 7.5 kPa·s/m.

[Example 5]

Using 60% by mass of hollow polyester fiber (hollow rate: 20%, fineness: 25dtex, fiber length: 50mm), 10% by mass of kenaf fiber (fineness: 30dtex, fiber length: 45mm) and 30% by mass of low Melting point polyester fiber (softening point: 120°C, denier: 7dtex, fiber length: 45mm) is used to make a sheet of fiber (weight per unit area: 400g/m ² , thickness: 25mm). Add and mix 20 parts by mass of sulfomethylated phenol-alkyl resorcinol-formaldehyde initial stage cocondensate (55% by mass solid content), 1 mass part of carbon black dispersion (30 mass% by mass), 3 Parts by mass of zirconium-based waterproofing agent (40% by mass solid content), 20 parts by mass of polyvinyl alcohol (6% by mass solid content, degree of saponification: 99mol%), 5 parts by mass of PRIMAL as a tackifier, TT-615 (manufactured by Rohm and Haas, trade name), 3 parts by mass of expanded graphite (expansion start temperature: 220°C, expansion rate: 200 times), 0.5 parts by mass of 27 mass% ammonia water, and 47.5 parts by mass of water to obtain a viscosity The immersion liquid is 840mPa·s. Using this impregnating liquid, impregnate it into the above-mentioned sheet-like fibers so that the solid content becomes 40% by mass, and then dry the sheet at 100 to 120°C for 3 minutes while pumping air in a drying chamber to precure the sheet. The fiber is materialized to produce a fiber sheet. In addition, as a skin material, 30 parts by mass of sulfomethylated phenol-alkyl resorcinol-formaldehyde initial cocondensate (55% mass solid content), 1 mass part of carbon black dispersion (30 mass% solid content), 2 mass parts of fluorine-based water and oil repellent (20 mass % solid content), 3 mass parts of phosphorus-containing, nitrogen-based flame retardants and 64 mass parts of water impregnated in The polyester non-woven fabric (weight per unit area: 30 g/m ² ) manufactured by the method, so that the solid content reaches 30% by mass, is then dried in a drying chamber at a temperature of 130-150°C for 2 minutes while pumping air. The non-woven fabric is pre-cured to obtain a non-woven fabric skin material. Next, when the pre-cured non-woven fabric skin material was laminated on the above-mentioned fiber sheet and molded into a predetermined shape by hot pressing at a temperature of 200°C for 60 seconds, a product with good shape and excellent water and oil repellency and rigidity was obtained. moldings. At the same time, during the molded product and molding operation, compared with the conventional glass wool, there is no scattering of dust from the glass or injury to the human body by the glass, so the workability is excellent. In addition, the flame retardancy of this molded product is V-0 in the UL94 standard, and it is a useful molded product as a sound absorbing material for a hood. The ventilation resistance of this molding was 20.5 kPa·s/m.

[Example 6]

80% by mass of hollow polyester fibers (hollow rate: 25%, fineness: 6dtex, fiber length: 55mm) and 20% by mass of low-melting polyester fibers (softening point: 120°C, fineness: 3dtex, fiber length: 45mm), the low-melting point polyester fibers contained in the fiber web are melted, and the fibers are bonded to each other by the melt to obtain a sheet-like fiber (weight per unit area : 400g/m ² , thickness: 30mm). Prepare the carbon black dispersion liquid (30 mass % solid content) of sulfinyl methylated phenol-alkyl resorcinol-formaldehyde primary cocondensate (50% mass solid content) of 30 mass parts, 0.5 mass part , 2 mass parts of fluorine-based water and oil repellent (20 mass % solid content), 5 mass parts of acrylic resin latex (50 mass % solid content), 3 mass parts of PRIMAL used in embodiment 3, ASE-60 , 5 parts by mass of heat-expandable granules (capsule type, MatmotoMicrosoft F-100: trade name manufactured by Matsumoto Yuyu Pharmaceutical Co., Ltd., shell softening temperature is 135 to 145° C.), 3 parts by mass of expanded graphite ( Expansion start temperature: 200° C., expansion rate: 150 times), 0.1 mass part of colloidal silica, 0.5 mass part of 27 mass % ammonia water, and 50.9 mass parts of water to form an immersion solution with a viscosity of 850 mPa·s. Using this impregnating liquid, impregnate it into the above-mentioned sheet-forming fibers so that the solid content becomes 40% by mass, and then dry the sheet at a temperature of 100 to 110°C for 3 minutes while pumping air in a drying chamber to precure the sheet. The fiber is materialized to produce a fiber sheet. The precured fiber sheet was molded into a predetermined shape by hot pressing at 180° C. for 60 seconds, and the heat-expandable particles were expanded while controlling the thickness to obtain a molded product. This molded product is excellent in sound absorption, rigidity, and water and oil repellency. The flame retardancy of this molded product is V-0 in the UL94 standard, and it is possible to obtain a molded product which is useful as a sound-absorbing material for an instrument panel of an automobile body and a shock-absorbing sound-absorbing material. The ventilation resistance of this molding was 30.3 kPa·s/m.

[Example 7]

In embodiment 6, as skin material, by 60 mass parts phenol-alkylresorcinol-formaldehyde initial cocondensate (55% mass solid content), 2 mass parts fluorine-based water and oil repellent (15 mass parts % solid content), 1 part by mass of carbon black dispersion (30% by mass solid content), 0.5 parts by mass of expanded graphite (expansion start temperature: 200°C, expansion rate: 150 times), 10 parts by mass of methyl cellulose (4% by mass aqueous solution) and 26.5 parts by mass of water impregnated in a polyester nonwoven fabric sheet with a weight per unit area of 80 g/m ² manufactured by the needle punching method to make the polyester nonwoven fabric The solid content in the cloth is 25% by mass, and polyamide powder (passing through 200 mesh) with a melting point of 120°C is used as a hot-melt adhesive and coated on the non-woven fabric at a coating amount of 5g/ ^m2 The back side of the sheet is then dried in a drying chamber at a temperature of 130-140° C. for 2 minutes, so that the hot-melt adhesive is attached to the back side of the non-woven fabric sheet and simultaneously pre-cured to obtain a skin material. The skin material was laminated on the precured fiber sheet obtained in Example 6, and molded into a predetermined shape by hot pressing at a temperature of 180° C. for 60 seconds, and the heat-expandable particles were expanded while limiting the thickness. To produce moldings. This molded product is excellent in sound absorption, rigidity, and water and oil repellency. The flame retardancy is also V-0 in the UL94 standard, and it can be used as a molded roof material for automobiles. The ventilation resistance of this molding was 31.0 kPa·s/m.

[Example 8]

60% by mass of polyester fiber (denier: 1.5dtex, fiber length: 45mm), 10% by mass of low-melting polyester fiber (softening point: 110°C, finer: 3dtex, fiber length: 54mm) and 30% by mass The hollow polyester fiber (hollow rate: 25%, fineness: 3dtex, fiber length: 50mm) is composed of a fiber web, and the sheet fiber (weight per unit area: 350g/m ² , thickness : 20mm). Then make the carbon black dispersion liquid (30 mass % solid content) of the sulfomethylated phenol-alkylresorcinol-formaldehyde primary cocondensate (50% mass solid content) of 40 mass parts, 0.5 mass part , 3 parts by mass of fluorine-based water and oil repellent (15 mass % solid content), 20 mass parts of polyvinyl alcohol (8 mass % solid content, degree of saponification: 99.5 mol %), 2 mass parts of PRIMAL used in Example 3, ASE-60 (manufactured by Rohm and Haas, trade name) and 1 part by mass of PRIMAL used in Example 5, TT-615 (manufactured by Rohm and Haas, trade name), 0.2 parts by mass of expanded graphite A (expansion start temperature: 130°C to 150°C, expansion rate: 150 times), 7 parts by mass of expanded graphite B (expansion start temperature: 300°C to 320°C, expansion rate: 150 times), 0.5 parts by mass of 27% by mass ammonia water, 0.1 parts by mass of 2,6-di-tert-butyl-p-cresol antioxidant and 25.7 parts by mass of water to form an immersion solution with a viscosity of 1200 mPa·s. Using this impregnating liquid, impregnate it into the above-mentioned sheet-like fibers so that the solid content becomes 40% by mass, and then dry the sheet at a temperature of 100 to 110°C for 3 minutes while pumping air in a drying chamber to precure the sheet. The fiber is materialized to produce a fiber sheet. And, as the skin material, by 40 mass parts sulfomethylated phenol-alkyl resorcinol-formaldehyde primary cocondensate (55% mass solid content), 1 mass part of carbon black dispersion liquid (30 mass % solid content) and 2 mass parts of fluorine-based water and oil repellent (15 mass % solid content) impregnated in the meta-type aromatic polyamide fiber non-woven fabric sheet (weight per unit area: 40g/m ² , fineness: 5dtex), so that the solid content in the aramid fiber non-woven fabric sheet reaches 20% by mass, and then dry in a drying room at a temperature of 140-150°C for 2 minutes to pre-cure the aromatic polyamide fiber non-woven fabric sheet. A family of polyamide fiber non-woven sheets to make skin materials. Next, the skin material is laminated on the above-mentioned fiber sheet, and molded into a predetermined shape by hot pressing at a temperature of 210° C. for 60 seconds, and the expanded graphite A in the fiber sheet is expanded while limiting the thickness to obtain a molded product. . This molded product is excellent in sound absorption, rigidity, heat resistance, and water and oil repellency. The flame retardancy is also V-0 in the UL94 standard, so it can be used as a sound-absorbing material for the hood of an automobile or an under-hood sound-absorbing material. The ventilation resistance of this molding was 10.2 kPa·s/m.

[Example 9]

In a synthetic resin bonded felt (weight per unit area: 800 g/m ² , thickness: 25 mm) using regenerated fibers, the impregnating solution used in Example 4 was impregnated so that the solid content in the felt became 10 mass %, and then dried in a drying room at a temperature of 100-130°C for 2 minutes to remove moisture, and then heat-molded at a temperature of 200-230°C for 3 minutes to obtain a fiber sheet. The fiber sheet is excellent in flame retardancy, and its molded product can be used for car carpets. The ventilation resistance of this molding was 6.6 kPa·s/m.

[Example 10]

70% by mass of kenaf fibers (denier: 30dtex, fiber length: 40mm) and 30% by mass of polypropylene fibers (softening point: 140°C, finer: 1.5dtex, fiber length: 40mm) were heated at a temperature of 180°C. To form a fiber web, the polypropylene fibers contained in the fiber web were melted, and the fibers were bonded to each other by the melt to obtain sheet-like fibers (weight per unit area: 500 g/m ² , thickness: 15 mm). Adding and mixing 85 parts by mass of acrylic resin latex (50% by mass solid content), 5 parts by mass of expanded graphite (expansion start temperature: 300°C, expansion rate: 150 times) and 10 parts by mass of polyvinyl alcohol aqueous solution (10 mass % solid content, saponification degree: 85 mol%) impregnation liquid, which is impregnated in the above-mentioned sheet fiber so that the solid content becomes 30 mass %, and then dried in a drying room at 100 to 130 ° C for 2 minutes to obtain Fiber sheet. The fiber sheet was then placed in a drying chamber at 150 to 180° C. for 5 minutes to melt the polypropylene fiber melt, and then cold pressed to obtain a molded product with a thickness of 5 mm. The molded product is excellent in rigidity and flame retardancy. Can be used for car door panels. The ventilation resistance of this molding was 90.5 kPa·s/m.

[Example 11]

A fiber composed of 95% by mass of polyester fiber (denier: 1.5dtex, fiber length: 36mm) and 5% by mass of low-melting polyester fiber (softening point: 110°C, finer: 4dtex, fiber length: 40mm) was used web, and a sheet-like fiber (weight per unit area: 80 g/m ² , thickness: 2 mm) was produced by a needle punching method. Added and mixed 65 parts by mass of phenol-alkylresorcinol-formaldehyde initial stage cocondensate (50% by mass solid content), 10 parts by mass of water-soluble epoxy resin (60% by mass solid content), 3 parts by mass Expanded graphite (expansion start temperature: 300 ° C, expansion rate: 150 times), 22 mass parts of polyvinyl alcohol aqueous solution (5 mass % solid content, saponification degree: 99.5 mol %) impregnation solution, and spray it Coat the above-mentioned sheet-like fiber so that the solid content becomes 40% by mass, and then dry it in a drying room at 150 to 180°C for 2 minutes, and use the obtained fiber sheet as a composite material consisting of rigid polyurethane foam and a skin material. Reinforcement material for substrates used in automotive molding roofs. The fiber sheet can be used as a reinforcing material excellent in rigidity and good in flame retardancy.

[Example 12]

With 30 mass parts of acrylic latex (50% mass solid content), 15 mass parts of polyvinyl alcohol (10% mass solid content, degree of saponification: 98.5mol%), 10 mass parts of PRIMAL, ASE-60 (Rohm and Haas Made by the company, trade name), 20 parts by mass of expanded graphite (expansion start temperature: 300 to 320°C, expansion rate: 130 times, particle size: 80 mesh), 1 part by mass of 27% by mass ammonia water, and 24 parts by mass of Water was mixed and ultrasonically stirred (frequency: 30 kHz, 5 minutes), and then the expanded graphite was dispersed while being finely divided. The viscosity of this aqueous solution was 840 mPa·s.

When the above-mentioned aqueous solution was impregnated into the sheet-formed fiber (weight per unit area: 50 g/m ² , thickness: 15 mm) of Example 1, expanded graphite was impregnated into the interior of the sheet-formed fiber. This is interpreted to mean that the particle size dispersibility of the expanded graphite becomes excellent because the expanded graphite is refined by the stirring of the ultrasonic waves.

[Example 13]

40% by mass of polyester fiber (denier: 5dtex, fiber length: 25mm), 20% by mass of low-melting polyester fiber (softening point: 110°C, finer: 2.5dtex, fiber length: 20mm) and 40% by mass kenaf fibers (denier: 40detx, fiber length: 30mm), the low-melting point polyester fibers contained in the fiber web are melted, and the fibers are bonded to each other by the melt to obtain a sheet Chemical fibers (weight per unit area: 250g/m ² , thickness: 30mm). Use the sulfomethylated phenol-alkylresorcinol-formaldehyde primary cocondensate (50% mass solid content) of 40 mass parts, the carbon black dispersion liquid (30% mass solid content) of 1 mass part, 2 An impregnating liquid composed of fluorine-based water and oil repellent (20 mass % solid content) and 57 mass parts water is impregnated in the above-mentioned sheet fiber so that the solid content reaches 40 mass %, Then dry at a temperature of 140-150° C. for 10 minutes in a drying chamber. Next, apply the expanded graphite dispersion obtained in Example 12 on both sides of the above-mentioned sheeted fibers by spraying, so that the amount of expanded graphite on each side is 40 g/m ² It was dried at a temperature of 5 minutes to obtain a pre-cured fiber sheet coated with expanded graphite. Polyethylene was then extruded to a thickness of 20 μm on the back of a nonwoven fabric having a weight per unit area of 50 g/m ² , which was composed of polyester fibers and produced by a spunbond method, to obtain a laminated nonwoven fabric. Using this non-woven fabric, 98 mass parts of the above-mentioned impregnation liquid was added and mixed with a flame retardant compound impregnating liquid of 2 mass parts of phosphorus and nitrogen flame retardants, so that the solid content reached 45%. The content of mass % is dried in a drying room at a temperature of 140-150° C. for 30 seconds to obtain a skin material. The skin material was laminated on the above-mentioned precured fiber sheet, and hot press-molded at a temperature of 200° C. for 45 seconds to obtain a molded product. The ventilation resistance of this molding was 58.3 kPa·s/m. In addition, the flame retardancy of this molded product is V-0 in the UL94 standard, and it can be used as an instrument panel sound-absorbing material and a shock-absorbing sound-absorbing material of an automobile body with excellent sound-absorbing properties.

The fibrous sheet of the present invention has high flame retardancy and is harmless to humans and animals, so it is extremely useful, for example, as interior materials for automobiles and buildings.

Claims (12)

1. A flame-retardant fiber sheet characterized by containing expanded graphite in the fiber. 2. The flame-retardant fiber sheet according to claim 1, wherein the fibers are hollow fibers or hollow fibers are mixed therein. 3. The flame-retardant fibrous sheet according to claim 1 or 2, wherein low-melting-point fibers having a melting point of 180°C or less are mixed in the fibers. 4. The flame-retardant fiber sheet according to any one of claims 1 to 3, wherein the fibers are bonded by a synthetic resin adhesive. 5. The flame-retardant fiber sheet according to claim 4, wherein the synthetic resin binder is an aqueous solution, and the expanded graphite is dispersed in the aqueous solution and impregnated in the fiber sheet . 6. The flame-retardant sheet according to claim 5, wherein a water-soluble resin is dissolved in the aqueous solution. 7. The flame-retardant fibrous sheet according to claim 5 or 6, wherein the synthetic resin binder is a phenolic resin which has been sulfomethylated and/or sulfinylmethylated. 8. A molded article obtained by molding the flame-retardant fiber sheet according to any one of claims 1 to 7 into a predetermined shape. 9. The molded article according to claim 8, wherein the ventilation resistance is 0.1 to 100 kPa·s/m. 10. A laminate, characterized in that on one or both sides of the flame-retardant fiber sheet according to any one of claims 1 to 7, another fiber sheet is laminated with a porous thermoplastic film interposed therebetween. material. 11. A molded article obtained by molding the laminate according to claim 10 into a predetermined shape. 12. The molded article according to claim 11, wherein the ventilation resistance is 0.1 to 100 kPa·s/m.