JP2010090490A - Flame retardant fiber sheet - Google Patents

Abstract

An object of the present invention is to provide a lightweight and incombustible fiber sheet.
There is provided a non-combustible fiber sheet, which is a fiber sheet mainly composed of alumina fibers, in which a synthetic resin is applied and / or impregnated and / or mixed. The fiber sheet is easy to mold and can be molded into a predetermined shape according to the application.
[Selection figure] None

Description

  The present invention relates to a fiber sheet mainly composed of alumina fibers.

Conventionally, as a fiber sheet used for, for example, automobile interior materials, synthetic fibers such as polypropylene fiber, polyester fiber, and acrylic fiber are entangled by needle punching, bound by a synthetic resin, or the above synthetic resin When some or all of the fibers are low-melting synthetic fibers, those that have been heat-sealed or made into sheets have been used. However, especially in the case of fiber sheets used for automobile interior materials, etc., flame retardant It is required to be sex.
In order to make the fiber sheet flame retardant, a method of applying or impregnating or mixing a flame retardant such as a phosphoric acid flame retardant, a dicarboxylic acid halide, antimony trioxide, and paraffin chloride is usually employed. Has been.

JP 2002-348766 A JP-A-10-226952 Japanese Patent Laid-Open No. 10-168756

  However, according to the above method, the fiber itself constituting the sheet is flammable, and the flame retardant is separated from the sheet.

As a means for solving the above-described conventional problems, the present invention is a fiber sheet mainly composed of alumina fibers, in which a synthetic resin is applied and / or impregnated and / or mixed. A fiber sheet is provided.
The synthetic resin is preferably a low melting point synthetic resin and / or a phenolic resin, the phenolic resin is sulfomethylated and / or sulfimethylated, and the low melting point synthetic resin is fibrous. Is desirable.
Usually, the fiber sheet is formed into a predetermined shape.

[Action]
In the present invention, since the sheet is mainly composed of alumina fibers that are incombustible, a highly incombustible or incombustible and lightweight fiber sheet can be obtained.

Phenol-based resins are relatively flame retardant among synthetic resins and are inexpensive, and are therefore suitable synthetic resins for use as binders or moldability imparting agents in the above sheets.
When using a phenol-based resin, it is desirable to make the aqueous resin solution stable in a wide pH range by sulfomethylation and / or sulfimethylation.
When a low melting point synthetic resin is used, the sheet can be softened by heating and cold press molding can be performed. In this case, when a fibrous material is used as the low-melting-point synthetic resin, the binding force increases because the low-melting synthetic resin is strongly entangled with alumina fibers and the like.
The said fiber sheet is shape | molded by the predetermined shape normally according to a use.

〔effect〕
The fiber sheet of the present invention is suitable for automobile interior materials and the like because it is non-combustible or highly flame-retardant and lightweight.

The present invention is described in detail below.
[Fiber sheet mainly composed of alumina fibers]
The alumina fiber sheet of the present invention is formed by, for example, forming an alumina fiber precursor spun by a blowing method using a spinning solution obtained by adding a silicon compound to a basic aluminum chloride aqueous solution, and firing the alumina fiber precursor sheet to obtain an alumina fiber. A method of forming a sheet is common. Details of the above method are described in detail in, for example, Japanese Patent Application Laid-Open Nos. 2007-325331 and 2008-7933. Needle punching may be applied to the alumina fiber precursor sheet produced by the above method or the alumina fiber sheet obtained therefrom.

  Examples of the alumina fiber sheet include ceramic fibers other than alumina fibers, inorganic fibers such as glass fibers and carbon fibers, polyethylene fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polypropylene fibers, polyester fibers, polyamide fibers, acrylic fibers, and urethane fibers. , Synthetic fiber such as polyvinyl chloride fiber, polyvinylidene chloride fiber, acetate fiber, wool, mohair, cashmere, camel hair, alpaca, vicuna, angora, silk thread, kiwatah, gama fiber, pulp, cotton, palm fiber, hemp fiber, Natural fibers such as bamboo fibers and kenaf fibers, biodegradable fibers made from lactic acid obtained from starch such as corn, cellulose artificial fibers such as rayon (human silk, sufu), polynosic, cupra, acetate, triacetate, etc. Organic fibers are mixed Which may be, but to ensure the non-combustible sheet, it is desirable to mix the amount of more than 15 wt% of the fiber sheet total amount in the case of the organic fibers. In the case of inorganic fibers, it is desirable to use an amount that does not adversely affect the physical properties of the alumina fiber sheet, for example, lightness, that is, a mixing amount of 25% by mass or less of the total amount of the fiber sheet.

[Synthetic resin]
A synthetic resin is applied and / or impregnated and / or mixed with the fiber sheet of the present invention.
Examples of the synthetic resin used in the present invention include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene terpolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, and polyvinyl acetate. , Fluororesins, thermoplastic acrylic resins, thermoplastic polyesters, thermoplastic polyamides, thermoplastic urethane resins, acrylonitrile-butadiene copolymers, styrene-butadiene copolymers, acrylonitrile-butadiene-styrene copolymers, etc. , Urethane resin, melamine resin, thermosetting acrylic resin, urea resin, phenolic resin, epoxy resin, thermosetting polyester, etc. are used, but urethane resin that produces the synthetic resin Prepoly -Epoxy resin prepolymer, melamine resin prepolymer, urea resin prepolymer (initial condensate), phenol resin prepolymer (initial condensate), diallyl phthalate prepolymer, acrylic oligomer, polyvalent isocyanate, methacrylic ester monomer, diallyl Synthetic resin precursors such as prepolymers such as phthalate monomers, oligomers, and monomers may be used. The above synthetic resins may be used alone or in combination of two or more, and are usually used as powder, emulsion, latex, aqueous solution, organic solvent solution and the like.

Desirable as the synthetic resin used in the present invention is a phenolic resin. Hereinafter, the phenolic resin used in the present invention will be described.
The phenolic resin is obtained by condensing a phenolic compound with formaldehyde and / or a formaldehyde donor.

[Phenolic compounds]
The phenolic compound used in the phenolic resin may be a monohydric phenol, a polyhydric phenol, or a mixture of a monohydric phenol and a polyhydric phenol. When only monohydric phenol is used, formaldehyde is easily released during and after curing. Therefore, polyhydric phenol or a mixture of monohydric phenol and polyhydric phenol is preferably used.

[Monohydric phenol]
Examples of the monohydric phenol include phenol, alkylphenols such as o-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol, xylenol, 3,5-xylenol, butylphenol, t-butylphenol, and nonylphenol, and o-fluoro. Phenol, m-fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, o-iodophenol, m-iodo Phenol, p-iodophenol, o-aminophenol, m-aminophenol, p-aminophenol, o-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-dinitro Examples include monohydric phenol substitutes such as enol and 2,4,6-trinitrophenol, and polycyclic monohydric phenols such as naphthol. These monohydric phenols may be used alone or in combination of two or more. I can do it.

[Polyphenol]
Examples of the polyhydric phenol include resorcin, alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, phloroglucin, bisphenol, dihydroxynaphthalene, and the like. These polyhydric phenols are used alone or in combination of two or more. can do. Among the polyhydric phenols, preferred is resorcin or alkylresorcin, and particularly preferred is alkylresorcin, which has a higher reaction rate with aldehyde than resorcin.

Examples of the alkyl resorcin include, for example, 5-methyl resorcin, 5-ethyl resorcin, 5-propyl resorcin, 5-n-butyl resorcin, 4,5-dimethyl resorcin, 2,5-dimethyl resorcin, 4,5-diethyl resorcin, 2 , 5-diethyl resorcin, 4,5-dipropyl resorcin, 2,5-dipropyl resorcin, 4-methyl-5-ethyl resorcin, 2-methyl-5-ethyl resorcin, 2-methyl-5-propyl resorcin, 2 , 4,5-trimethylresorcin, 2,4,5-triethylresorcin and the like.
A polyhydric phenol mixture obtained by dry distillation of an Estonia oil shale is inexpensive and contains a large amount of highly reactive various alkylresorcins in addition to 5-methylresorcin. Therefore, it is a particularly preferable polyhydric phenol raw material in the present invention.

[Formaldehyde donor]
In the present invention, the phenolic compound is condensed with formaldehyde and / or a formaldehyde donor, and the formaldehyde donor means a compound that forms and provides formaldehyde when decomposed or a mixture of two or more thereof. Examples of such aldehyde donors include paraformaldehyde, trioxane, hexamethylenetetramine, tetraoxymethylene and the like. In the present invention, formaldehyde and formaldehyde donor are collectively referred to as formaldehyde hereinafter.

[Production of phenolic resins]
There are two types of the phenolic resin, a resole obtained by reacting with an alkali catalyst with an excess of formaldehyde with respect to the phenolic compound, and an acid catalyst with an excess of phenol with respect to the formaldehyde. There are novolaks obtained by reacting, and resole consists of a mixture of various phenol alcohols added with phenol and formaldehyde, usually provided in aqueous solution, novolac is a variety of dihydroxydiphenylmethane series in which phenol is further condensed with phenol. It consists of a derivative and is usually provided as a powder.
In the phenolic resin used in the present invention, first, the phenolic compound and formaldehyde are condensed to form an initial condensate, and after the initial condensate is adhered to the fiber sheet, a curing catalyst and / or Resinized by heating.
In order to produce the above condensate, monohydric phenol and formaldehyde may be condensed to form a monohydric phenol single initial condensate, or a mixture of monohydric phenol and polyhydric phenol may be condensed with formaldehyde. The monohydric phenol-polyhydric phenol initial cocondensate may be used. In order to produce the initial condensate, either one or both of monohydric phenol and polyhydric phenol may be used as the initial condensate in advance.

In the present invention, a desirable phenolic resin is a phenol-alkylresorcin cocondensate. The phenol-alkylresorcin cocondensate is stable in an aqueous solution of the cocondensate (initial cocondensate) and is stored for a long time at room temperature as compared with a condensate (initial condensate) composed only of phenol. There is an advantage that you can. Further, the fiber sheet obtained by impregnating or applying the aqueous solution to the sheet base material and pre-curing is good, and the moldability is not lost even if the fiber sheet is stored for a long period of time. Furthermore, alkylresorcin has a high reactivity with formaldehydes and captures and reacts with a free aldehyde, so that it also has an advantage of reducing the amount of free aldehyde in the resin.
A desirable method for producing the phenol-alkylresorcin cocondensate is to first react phenol with formaldehyde to produce a phenolic resin initial condensate, and then add alkylresorcin to the phenolic resin initial condensate. If it becomes, it is a method of adding formaldehyde and reacting.

  For example, in the above-mentioned condensation of (a) monohydric phenol and / or polyhydric phenol and formaldehyde, usually 0.2 to 3 mol of formaldehyde is 1 mol of monohydric phenol and formaldehyde is 1 mol of polyhydric phenol. 0.1 to 0.8 mol of the compound and, if necessary, a solvent and a third component are added, and the mixture is heated and reacted at a liquid temperature of 55 to 100 ° C. for 8 to 20 hours. At this time, all the formaldehydes may be added at the start of the reaction, or may be added in divided portions or continuously.

  Furthermore, in the present invention, as the phenolic resin, if desired, urea, thiourea, melamine, thiomelamine, dicyandiamine, guanidine, guanamine, acetoguanamine, benzoguanamine, 2,6-diamino-1,3-diamine amino series An initial condensate composed of a resin monomer and / or the amino resin monomer may be added to cause co-condensation with the phenol compound and / or the initial condensate.

  During the production of the phenolic resin, before, during or after the reaction, for example, hydrochloric acid, sulfuric acid, orthophosphoric acid, boric acid, oxalic acid, formic acid, acetic acid, butyric acid, benzenesulfonic acid, phenolsulfonic acid, para Inorganic or organic acids such as toluenesulfonic acid, naphthalene-α-sulfonic acid, naphthalene-β-sulfonic acid, esters of organic acids such as dimethyl oxalate, acid anhydrides such as maleic anhydride, phthalic anhydride, Ammonium salts such as ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium oxalate, ammonium acetate, ammonium phosphate, ammonium thiocyanate, ammonium imidosulfonate, monochloroacetic acid or sodium salt thereof, organic halides such as α, α'-dichlorohydrin, Triethanolamine hydrochloride , Hydrochlorides of amines such as aniline hydrochloride, urea adducts such as urea adducts salicylate, urea stearate, urea adduct heptanoate, acidic substances such as N-trimethyltaurine, zinc chloride, ferric chloride, ammonia, amines Alkali metals such as sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, hydroxides of alkaline earth metals, oxides of alkaline earth metals such as lime, sodium carbonate, sodium sulfite, sodium acetate An alkaline substance such as weak acid salts of alkali metals such as sodium phosphate may be mixed as a catalyst or a pH adjuster.

The initial condensate (including the initial cocondensate) of the phenolic resin of the present invention may be further mixed with a curing agent such as the above formaldehydes or alkylolated triazone derivatives.
The alkylolated triazone derivative is obtained by a reaction of a urea compound, an amine and formaldehyde. Examples of the urea compounds used in the production of alkylolated triazone derivatives include alkyl ureas such as urea, thiourea and methylurea, alkylthioureas such as methylthiourea, phenylurea, naphthylurea, halogenated phenylurea, and nitrated alkyl. Examples thereof include urea alone or a mixture of two or more. A particularly desirable urea compound is urea or thiourea. In addition, amines such as aliphatic amines such as methylamine, ethylamine, propylamine, isopropylamine, butylamine and amylamine, amines such as benzylamine, furfurylamine, ethanolamine, ethylenediamine, hexamethylenediamine and hexamethylenetetramine, as well as ammonia. These are used alone or as a mixture of two or more. The formaldehydes used in the production of the alkylolated triazone derivative are the same as the formaldehydes used in the production of the initial condensate of phenolic resin.
In the synthesis of the above-mentioned alkylolated triazone derivative, a ratio of 0.1 to 1.2 mol of amines and / or ammonia and a ratio of 1.5 to 4.0 mol of formaldehydes is usually 1 mol of urea compound. React with. In the above reaction, the order of addition is arbitrary, but as a preferred reaction method, first, the required amount of formaldehydes is charged into the reactor, and the amines and / or ammonia are usually kept at a temperature of 60 ° C. or lower. There is a method in which a required amount is gradually added, and a required amount of a urea compound is further added, followed by stirring and heating at 80 to 90 ° C. for 2 to 3 hours. As formaldehydes, 37% formalin is usually used, but a part thereof may be replaced with paraformaldehyde in order to increase the concentration of the reaction product. When hexamethylenetetramine is used, a reaction product having a higher solid content can be obtained. Reactions of urea compounds, amines and / or ammonia, and formaldehydes are usually carried out in aqueous solution, but instead of part or all of water, methanol, ethanol, isopropanol, n-butanol, ethylene glycol, diethylene glycol, etc. These alcohols may be used alone or as a mixture of two or more kinds, and water-soluble organic solvents such as ketones such as acetone and methyl ethyl ketone may be used alone or in combination of two or more kinds. The addition amount of the curing agent is 10 to 100 parts by mass with respect to 100 parts by mass of the initial condensate (initial cocondensate) of the phenolic resin of the present invention in the case of formaldehyde, and the phenol in the case of an alkylolated triazone derivative. It is 10 to 500 parts by mass with respect to 100 parts by mass of the initial condensate (initial cocondensate) of the resin.

[Sulfomethylation and / or sulfimethylation of phenolic resins]
In order to improve the stability of the water-soluble phenolic resin, it is desirable to sulfomethylate and / or sulfmethylate the phenolic resin.

[Sulfomethylating agent]
Examples of sulfomethylating agents that can be used to improve the stability of water-soluble phenolic resins include sulfite, bisulfite or metabisulfite, and alkali metals or quaternary amines or quaternary compounds such as trimethylamine or benzyltrimethylammonium. Examples thereof include water-soluble sulfites obtained by reacting with secondary ammonium and aldehyde adducts obtained by reacting these water-soluble sulfites with aldehydes.
Examples of the aldehyde adduct include formaldehyde, acetaldehyde, propionaldehyde, chloral, furfural, glyoxal, n-butyraldehyde, caproaldehyde, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde, etc. An aldehyde adduct composed of formaldehyde and sulfite is, for example, hydroxymethanesulfonate.

[Sulfimethylating agent]
Sulfimethylating agents that can be used to improve the stability of water-soluble phenolic resins include aliphatic and aromatic aldehyde alkali metal sulfoxylates such as formaldehyde sodium sulfoxylate (Longalite) and benzaldehyde sodium sulfoxylate. Examples thereof include alkali metals such as sodium hydrosulfite and magnesium hydrosulfite, hydrosulfites (dithionates) of alkaline earth metals, and hydroxyalkanesulfinates such as hydroxymethanesulfinate.

When the above-mentioned phenolic resin initial condensate is sulfomethylated and / or sulfimethylated, a sulfomethylating agent and / or a sulfimethylating agent may be added to the initial condensate at an optional stage to obtain a phenolic compound and / or initial condensate. Is sulfomethylated and / or sulfimethylated.
The addition of the sulfomethylating agent and / or the sulfymethylating agent may be performed at any stage before, during or after the condensation reaction.

  The total amount of the sulfomethylating agent and / or sulfmethylating agent is usually 0.001 to 1.5 mol with respect to 1 mol of the phenol compound. When it is 0.001 mol or less, the hydrophilicity of the phenolic resin is not sufficient, and when it is 1.5 mol or more, the water resistance of the phenolic resin is deteriorated. In order to satisfactorily maintain performance such as curability of the initial condensate to be produced and physical properties of the resin after curing, the content is preferably about 0.01 to 0.8 mol.

  The sulfomethylating agent and / or sulfimethylating agent added to sulfomethylate and / or sulfmethylate the initial condensate reacts with the methylol group of the initial condensate and / or the aromatic ring of the initial condensate, A sulfomethyl group and / or a sulfimethyl group is introduced into the initial condensate.

  The aqueous solution of the precondensate of the phenolic resin thus sulfomethylated and / or sulfimethylated is stable in a wide range from acidic (pH 1.0) to alkaline, and in any of acidic, neutral and alkaline regions. Can be cured. In particular, when cured on the acidic side, residual methylol groups are reduced, and the cured product is not decomposed to generate formaldehyde.

  The synthetic resin used in the present invention further includes 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, alumina, silica, diatomaceous earth, dolomite, gypsum, talc, clay, asbestos, mica, calcium silicate, bentonite, white carbon, carbon black, iron powder, aluminum powder, glass powder, stone powder, blast furnace slag, fly ash Inorganic fillers such as cement, zirconia powder; natural rubber or derivatives thereof; styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, isoprene rubber, isoprene-isobutylene rubber Synthetic rubber: polyvinyl alcohol, sodium alginate, starch, starch derivatives, glue, gelatin, blood powder, water-soluble polymers such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyacrylate, polyacrylamide, and natural gums; wood flour, Organic fillers such as walnut powder, coconut powder, wheat flour and rice flour; higher fatty acids such as stearic acid and palmitic acid; higher alcohols such as palmityl alcohol and stearyl alcohol; esters of fatty acids such as butyryl stearate and glycerin monostearate Fatty acid amides; natural waxes such as carnauba wax; synthetic waxes; mold release agents such as paraffins, paraffin oil, silicone oil, silicone resin, fluororesin, polyvinyl alcohol, grease; Organic foaming agents such as sodium bicarbonate, potassium bicarbonate, heavy carbonate, dinitrosopentamethylenetetramine, P, P′-oxybis (benzenesulfonylhydrazide), azobis-2,2 ′-(2-methylgropionitrile) Inorganic foaming agents such as ammonium carbonate; hollow particles such as shirasu balloon, perlite, glass balloon, foamed glass, hollow ceramics; plastic foams and foamed particles such as foamed polyethylene, foamed polystyrene, foamed polypropylene; pigments, dyes, antioxidants Agents, antistatic agents, crystallization accelerators, phosphorus compounds, nitrogen compounds, sulfur compounds, boron compounds, bromine compounds, guanidine compounds, phosphate compounds, phosphate ester compounds, amino resins, etc. Flame retardant, flame retardant, water repellent, oil repellent, insect repellent, antiseptic, waxes, surfactant, Lubricants, antioxidants, UV absorbers; DBP, DOP, phthalate plasticizers such as dicyclohexyl phthalate, and other plasticizers such as tricresyl phosphate may be added and mixed.

Further preferred as the synthetic resin of the present invention is a low-melting-point synthetic resin having a melting point of 200 ° C. or lower, such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, low-melting point polyester, and low-melting point polyamide. The low melting point synthetic resin is preferably in the form of a fiber in order to entangle other fibers or the low melting point synthetic resin in the sheet.
When the low-melting-point synthetic resin is used as the synthetic resin, the fiber sheet becomes thermoplastic and is easily heated and softened, so that cold press forming, vacuum and / or pressure forming are facilitated.

  When a liquid synthetic resin or a synthetic resin solution is applied and / or impregnated and / or mixed with the fiber sheet, the fiber sheet is dried after being applied, impregnated or mixed. When the synthetic resin contained in the fiber sheet is a thermosetting resin, when the resin is in the B state, it can be stored for a long time and can be molded at a low temperature and a short time.

In order to apply or impregnate the fiber sheet with a synthetic resin, the fiber sheet is usually immersed in a liquid synthetic resin or a synthetic resin solution, or a liquid synthetic resin or a synthetic resin solution is sprayed on the fiber sheet, or a knife is used. Apply with a coater, roll coater, flow coater, etc.
In order to adjust the amount of the synthetic resin in the fiber sheet impregnated or mixed with the synthetic resin, after impregnating or mixing the synthetic resin, the fiber sheet is squeezed using a drawing roll or a press machine. In this case, the thickness of the fiber sheet is reduced, but the alumina fiber, which is the main component of the fiber sheet, has high rigidity, and after squeezing, the thickness is elastically restored, and a certain thickness is secured. In particular, when the fiber sheet contains low melting point synthetic fibers, the fiber sheet is heated to melt the low melting point synthetic resin or the low melting point synthetic fibers, and the fibers are bound by the melt. It is desirable to keep it. If it does so, intensity | strength and rigidity will further improve this fiber sheet, the workability | operativity at the time of a synthetic resin impregnation will improve, and the restoration | restoration of the thickness after drawing will also become remarkable.

  When the synthetic resin is a phenolic resin, in the case of a novolak, it is generally mixed with a fiber as a powdery initial condensate and formed into a sheet, and when the synthetic resin is an aqueous solution of an initial condensate (initial condensate liquid), The fiber sheet is impregnated or coated. The initial condensate liquid is optionally methanol, ethanol, isopropanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, methyl. Alcohols such as amyl alcohol, 2-ethylbutanol, n-heptanol, n-octanol, trimethyl alcohol, cyclohexanol, benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, abiethyl alcohol, diacetone alcohol, acetone, methylacetone , Methyl ethyl ketone, methyl-n-propyl ketone, diisobutyl ketone, acetonyl acetone, methyl oxide, cyclohexanone, methyl cyclohexano , Ketones such as acetophenone, camphor, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, polyethylene glycol and other glycols, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl Ethers, glycol ethers such as triethylene glycol monomethyl ether, esters of the above glycols such as ethylene glycol diacetate and diethylene glycol monoethyl ether acetate and their derivatives, ethers such as 1,4-dioxane, diethyl cellosolve, diethyl carb Tall, ethyl lactate, isopropyl lactate, jig Call diacetate, a water-soluble organic solvent such as dimethylformamide may be used.

[Molding of fiber sheet]
The fiber sheet of the present invention is molded into a flat plate shape or a predetermined shape, and hot press molding is applied to normal molding. The fiber sheet of the present invention may be formed into a predetermined shape by hot pressing after being formed into a flat plate shape by hot pressing, and includes a low melting point synthetic resin, a low melting point synthetic resin fiber or other thermoplastic resin. If it is, the low-melting point synthetic resin or thermoplastic resin may be softened by heating and then molded into a predetermined shape by cold pressing. A plurality of the fiber sheets of the present invention may be used in a stacked manner. The fiber sheet of the present invention is, for example, a base material for an interior material such as a ceiling material of an automobile, a dash silencer, a hood silencer, an engine under cover silencer, a cylinder head cover silencer, a dash outer silencer, a floor mat, a dashboard, and a door trim. It is useful as a reinforcing material laminated on the material, a sound absorbing material, a heat insulating material, a building material or the like.

The ventilation resistance of the molded product obtained from the fiber sheet of the present invention is desirably 0.01 to 100 kPa · s / m.
Here, the ventilation resistance R (Pa · s / m) is a scale representing the degree of ventilation of the breathable material. The measurement of the ventilation resistance R is performed by a steady flow differential pressure measurement method. As shown in FIG. 1, a test piece T is arranged in a cylindrical air passage W, and the pressure in the air passage W on the start point side of the arrow in the figure in a state of a constant air flow V (the direction of the arrow in the figure). By measuring the pressure difference between P1 and the end point P2 of the arrow in the figure, the ventilation resistance R can be obtained from the following equation.
(Formula) R = ΔP / V
Here, ΔP (= P1−P2): Pressure difference (Pa), V: Air flow rate per unit area (m ³ / m ² · s). The ventilation resistance R (Pa · s / m) is in a relationship of air permeability C (m / Pa · s) and C = 1 / R.
The ventilation resistance can be measured by, for example, an air permeability tester (product name: KES-F8-AP1, manufactured by Kato Tech Co., Ltd., steady flow differential pressure measurement method).
A molded product having a ventilation resistance in the range of 0.01 to 100 kPa · s / m is excellent in sound absorption.

You may laminate | stack other materials, such as a skin material, a back surface material, a core material, and another fiber sheet, on the single side | surface or both surfaces of the fiber sheet of this invention. Adhesion between the fiber sheet of the present invention and another material may be performed via a hot melt sheet or hot melt adhesive powder, or when the synthetic resin is applied to the fiber sheet, the fiber sheet may be adhered by the synthetic resin. .
Examples of the hot melt sheet and hot melt adhesive powder include polyolefin resins (including modified polyolefin resins) such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and polyurethane. A low melting point synthetic resin such as one kind or a mixture of two or more kinds such as polyester, polyester copolymer, polyamide and polyamide copolymer is used as a material.
When the hot melt sheet is used for adhesion, for example, the hot melt sheet extruded from a T-die is laminated on the fiber sheet of the present invention, and another material is laminated on the fiber sheet and hot press molding is performed. .
Furthermore, in order to attach the fiber sheet to the part, it is possible to use a metal fitting, use the above-mentioned adhesive, or if the part is plastic, it can be attached by using heat fusion, high frequency, or ultrasonic adhesive. .

In order to ensure air permeability, the hot melt sheet is desirably porous. In order to make the hot melt sheet porous, the hot melt sheet is previously provided with pores, or the hot melt sheet is laminated on the fiber sheet and then provided with a needle or the like, or the fiber sheet is provided with a porous material. For example, when a hot-softened hot melt sheet extruded from a T-die is laminated and pressed, fine pores are formed in the film. The pores are formed by fluff on the surface of the fiber sheet. This method does not require the step of previously making the hot melt sheet porous, and the fine pores have a positive effect on the sound absorption of the product. When the fibrous or powdery hot melt adhesive is used for bonding, the air permeability of the laminate is ensured.
It is desirable that the ventilation resistance of the laminate obtained by molding the laminate into a predetermined shape is 0.01 to 100 kPa · s / m. A molded product having a ventilation resistance in the range of 0.01 to 100 kPa · s / m is excellent in sound absorption.

  Hereinafter, the present invention will be described by way of examples. In addition, this invention is not limited only to the Example shown below.

[Example 1]
Needle punching into a web of mixed fibers composed of 80% by mass of alumina fibers (fineness: 12.5 dtex, fiber length: 55 mm) and 20% by mass of low melting point polyester fibers (softening point: 110 ° C., fineness: 15 dtex, fiber length: 50 mm) Was applied to produce a fiber sheet having a basis weight of 120 g / m ² . Next, a phenol-formaldehyde initial condensate (45 mass% solid aqueous solution) as a synthetic resin was coated and impregnated with a roll so that the coating amount was 30 mass% with respect to the fiber sheet, and then at 130 to 140 ° C. The fiber sheet was dried for 3 minutes, and the fiber sheet was pre-cured to bring the phenol-formaldehyde initial condensate into the B state, thereby obtaining a non-combustible fiber sheet. The obtained noncombustible fiber sheet was hot-press-molded at 200 ° C. for 60 seconds to obtain a molded product having a thickness of 3 mm.

[Example 2]
Recycled alumina flakes were made into cotton with an opening machine to obtain anti-wool cotton. Next, a novolak-type phenol resin powder containing hexamethylenetetramine (particle size: 20 to 30 μm, melting point: 78 to 85 ° C.) is added so as to be 30% by mass with respect to the anti-wool, and the anti-wool is further added. After opening and mixing to form a fleece, both sides of the fleece were precured with hot air at 150 ° C. to make the phenol resin a B state, and a nonflammable fiber sheet having a thickness of 15 mm and a basis weight of 800 g / m ² was obtained. . The obtained non-combustible fiber sheet was hot-press-molded at 200 ° C. for 60 seconds to obtain a molded product having a thickness of 5 mm.

Example 3
Recycled alumina flakes were made into cotton with an opening machine to obtain anti-wool cotton. Next, hexamethylenetetramine-containing novolac-type phenol resin powder (particle size: 20 to 30 μm, melting point: 78 to 85 ° C.) was added so as to be 20% by mass with respect to the anti-wool. The fleece is formed by fusing to open a fleece, and both sides of the fleece are precured with hot air at 150 ° C. to bring the phenol resin into a B state to obtain a non-combustible fiber sheet having a thickness of 15 mm and a basis weight of 600 g / m ^2. It was. The obtained non-combustible fiber sheet was hot-press-molded at 200 ° C. for 60 seconds to obtain a molded product having a thickness of 5 mm.

[Comparative Example 1]
A mixed fiber web comprising 80% by mass of polyester fiber (fineness: 6.6 dtex, fiber length: 60 mm) and 20% by mass of low melting point polyester fiber (softening point: 110 ° C., fineness: 3.3 dtex, fiber length: 55 mm). A fiber sheet having a basis weight of 120 g / m ² was manufactured by performing needle punching. Next, a mixed solution composed of 70% by mass of a phenol-formaldehyde initial condensate (45% by mass solid solution) as a synthetic resin and 30% by mass of a melamine-coated ammonium polyphosphate powder (particle size: 20 to 40 μm) as a flame retardant The fiber sheet was coated and impregnated with a roll so as to give a coating amount of 60% by mass, dried at 130 to 140 ° C. for 5 minutes, precured, and then hot pressed at 200 ° C. for 60 seconds. As a result, a molded product having a thickness of 3 mm was obtained.

[Flame retardance test]
Table 1 shows the results obtained by using the molded products obtained in Examples 1, 2, 3 and Comparative Example 1 and performing the flame retardancy according to the UL94 standard at the normal state and after the durability test.

  From Table 1, it can be seen that the molded products of the examples have good flame retardance even after the state and durability test (almost non-flammable), but the comparative examples have poor flame retardance after the durability test.

Example 4
Needle punching was further applied to a 100% by mass sheet of alumina fibers (fineness: 12 dtex, fiber length: 60 mm) to produce a fiber sheet having a basis weight of 100 g / m ² . Next, after applying and impregnating a phenol-alkylresorcin-formaldehyde initial condensate (50 mass% solid content aqueous solution) as a synthetic resin with a roll so as to be an application amount of 40 mass% with respect to the fiber sheet, 130- It was dried and cured at 140 ° C. for 1 minute to give the phenol-alkylresorcin-formaldehyde initial condensate in the B state to obtain a nonflammable fiber sheet. Using the non-combustible fiber sheet as a skin material, and using a glass wool raw cotton (weight per unit area 700 g / m ² ) coated with 15% by mass of an uncured resol type phenol resin as a base material, the back surface of the non-combustible fiber sheet And glass wool raw cotton were polymerized and subjected to hot press molding at 200 ° C. for 60 seconds to obtain a molded product having a thickness of 10 mm. As a result of measuring the molded product according to the FMVSS-302 method, the flame retardancy was incombustible.

Example 5
Phenol-formaldehyde initial condensate (50% by weight solids aqueous solution) 30 parts by weight, carbon black dispersion (30% by weight solids) 1 part by weight, fluorinated water and oil repellent (20% by weight solids) 0.5 A mixed solution consisting of part by mass and 68.5 parts by mass of water was uniformly mixed using a homomixer to prepare a synthetic resin solution. The above synthesis is performed on the back surface of a fiber sheet (weight per unit area 30 g / m ² ) obtained by heating 90 parts by mass of alumina fiber and 10 parts by mass of low-melting polyester fiber (melting point 120 ° C.) at 200 ° C. for 0.5 minutes. The resin liquid is applied to the fiber sheet by spray coating so that the solid content is 30% by mass, dried in a drying chamber at 140 to 150 ° C. for 2 minutes, precured, and the phenol-formaldehyde initial condensate is brought into a B state. A non-combustible fiber sheet was obtained. Using the non-combustible fiber sheet as a skin material, and using a glass wool raw cotton (weight per unit area 600 g / m ² ) coated with 15% by mass of an uncured resol type phenol resin as a base material, the back surface of the non-combustible fiber sheet Glass wool raw cotton was polymerized and hot-pressed at 200 ° C. for 65 seconds to obtain a molded product having a thickness of 10 mm. This product is non-combustible according to the safety standard of automobile interior goods, the FMVSS-302 method, and is a lightweight and excellent molded product with excellent weather resistance.

Example 6
A fiber web composed of 70% by mass of alumina fibers (fineness: 12 dtex, fiber length: 60 mm) and low melting point polyester fibers (softening point: 110 ° C., fineness: 10 dtex, fiber length: 60 mm) is used. The low-melting polyester fiber contained therein was melted, and the fibers were bonded together by the melt to produce a fiber sheet (weight per unit area: 400 g / m ² , thickness: 40 mm). Next, 30 parts by mass of the phenol-formaldehyde initial condensate (50% by mass aqueous solution) used in Example 5, 1 part by mass of a carbon black dispersion (30% by mass solids), a fluorine-based water / oil repellent (20 (Mass% solid content) The fiber sheet is dipped in a mixed solution consisting of 0.5 parts by mass and 68.5 parts by mass of water, impregnated so that the fiber sheet has a solid content of 40% by mass, and dried. It dried for 3 minutes at 100-110 degreeC, attracting | sucking indoors, this impregnation fiber sheet was pre-cured, and this phenol-formaldehyde initial condensate was made into the B state, and the nonflammable fiber sheet was obtained. Next, the non-combustible fiber sheet was used as a base material, the non-combustible fiber sheet prepared in Example 4 was polymerized as a skin material, and hot-pressed into a predetermined shape at 200 ° C. for 60 seconds. This product is non-combustible according to the safety standard of automobile interior goods, the FMVSS-302 method, and is a lightweight and excellent molded product with excellent weather resistance.

Example 7
Recycled alumina fiber was made into cotton with an opening machine to obtain anti-wool cotton. Next, hexamethylenetetramine-containing novolac-type phenol resin powder (particle diameter: 20 to 30 μm, melting point: 78 to 85 ° C.) was added so as to be 15% by mass with respect to the anti-wool, and the anti-wool was further opened. After fleece mixing to form a fleece, the fleece was precured with hot air at 150 ° C. to bring the phenol resin into a B state, and a nonflammable fiber sheet having a thickness of 15 mm and a basis weight of 1000 g / m ² was obtained. The obtained noncombustible fiber sheet was hot-press-molded at 200 ° C. for 60 seconds to obtain a molded product having a thickness of 3 mm. This is V94 of UL94 standard, is lightweight, excellent in weather resistance and rigidity, and is useful as an automobile door trim or dashboard.

Example 8
A fiber sheet composed of 80% by mass of alumina fibers (fineness: 10.5 dtex, fiber length: 65 mm) and 20% by mass of polyester fibers (fineness: 12 dtex, fiber length: 60 mm) is subjected to needle punching, and a basis weight of 80 g / m ^2. The fiber sheet was manufactured. Next, 30 parts by mass of sulfomethylated / phenol-alkylresorcin-formaldehyde initial cocondensate (50 mass% solid aqueous solution), 1 part by mass of carbon black dispersion (30 mass% solid), fluorine-based water and oil repellent (20% by mass solid content) A mixed liquid consisting of 1.5 parts by mass and 67.5 parts by mass of water is prepared, the fiber sheet is immersed in the mixed liquid, and the mixed liquid is solidified in the fiber sheet to 40 mass. % Impregnated so that the impregnated fiber sheet has 20 parts by mass of polyamide powder (softening point: 130 ° C., particle size: 40 to 50 μm) as hot melt adhesive on the back side of the impregnated fiber sheet to 80 parts by mass of water. The dispersed dispersion is applied by spraying to a solid content of 25% by mass, dried at 130 to 140 ° C. for 2 minutes, and the fiber sheet is precured to form the sulfomethylated / feature. Lumpur - alkylresorcin - formaldehyde initial co-condensation product is B state to obtain a skin material made of noncombustible fibrous sheet. Next, the non-combustible fiber sheet according to Example 6 was used as a base material, and the skin material of the non-combustible fiber sheet was polymerized on both surfaces thereof, followed by hot-press press forming at 210 ° C. for 60 seconds to obtain a molded product. This molded product has a ventilation resistance of 40.5 kPa · s / m, flame resistance is V94 of UL94 standard, is lightweight, has good sound absorption and weather resistance, automotive hood silencer and engine undercover silencer Useful as.

  Since the fiber sheet of the present invention is incombustible or highly flame-retardant and lightweight, it is extremely useful for automobile interior materials and the like.

It is explanatory drawing explaining the measuring method of ventilation resistance R. FIG.

Explanation of symbols

W Ventilation path T Test piece

Claims (5)

  A non-combustible fiber sheet, characterized in that it is a fiber sheet mainly composed of alumina fibers, wherein the sheet is coated and / or impregnated and / or mixed with a synthetic resin.   The incombustible fiber sheet according to claim 1, wherein the synthetic resin is a low-melting-point synthetic resin and / or a phenol resin.   The incombustible fiber sheet according to claim 2, wherein the phenolic resin is sulfomethylated and / or sulfimethylated.   The incombustible fiber sheet according to claim 2 or 3, wherein the low-melting-point synthetic resin is fibrous.   The non-combustible fiber sheet according to any one of claims 1 to 4, wherein the fiber sheet is formed into a predetermined shape.