JP4796836B2 - Aqueous binder for inorganic fiber and heat insulating sound absorbing material for inorganic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a formaldehyde free water-based mineral fiber binder composition with rapid hardening reaction in a short period to give a binder cured material with excellent strength and a mineral fiber insulating acoustic material using it. <P>SOLUTION: The mineral fiber insulating acoustic material is molded using the water-based mineral fiber binder composition comprising polycarboxylic acids containing 2 or more carboxyl group in the molecule, a cross-linking agent and a hardening accelerator containing at least one or over of hydrosulfite(s), wherein the number of moles of the functional group capable of reacting with the carboxyl group in the cross-linking agent based on the number of moles of the carboxyl group in the polycarboxylic acids is 0.8-1.5 in a mole ratio. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to an aqueous binder for inorganic fibers that does not contain formaldehyde and an inorganic fiber heat insulating sound absorbing material using the same, which can be suitably used for heat insulating sound absorbing materials made of inorganic fibers such as glass wool or rock wool.

  Conventionally, in heat-absorbing sound-absorbing materials made of inorganic fibers such as glass wool or rock wool, phenolic resin-based binders mainly composed of phenol / formaldehyde resin (or resol type phenolic resin) are widely used as binders for bonding fibers together. in use. These phenolic resin-based binders are heat-cured in a relatively short time and a strong cured product is obtained, so that the inorganic fiber heat-absorbing sound-absorbing material using this is shape-retaining, thickness-restorability after opening the compressed package, Excellent bending resistance.

  However, when a phenolic resin binder is used, formaldehyde is released during the manufacturing process, particularly when the binder is cured. Therefore, the treatment and response of the released formaldehyde has become a problem. Particularly in recent years, due to the reduction of environmental load, the regulation of formaldehyde emission has been demanded by laws and regulations, etc., and binders for inorganic fiber heat-absorbing sound-absorbing materials with low environmental load are desired, and many proposals have been made. ing.

  For example, Patent Document 1 listed below includes (a) a polyacid containing at least two carboxylic acid groups, acid anhydride groups, or salts thereof, (b) a polyol containing at least two hydroxyl groups, and (C) containing a phosphorus-containing accelerator, and the equivalent ratio of the carboxylic acid group, acid anhydride group, or salt thereof: the hydroxyl group is about 1 / 0.01 to about 1 A curable aqueous composition is disclosed wherein the carboxylic acid group, acid anhydride group, or salt thereof is neutralized with a non-volatile base to the extent of about 35% or less.

  Further, Patent Document 2 below discloses a binder resin suitable for inorganic fibers such as glass or stone wool, which is a mixture of two different types of acid anhydrides and amines but does not contain a polymer but contains a reaction product. ing.

  Patent Document 3 listed below discloses a water-soluble composition containing a polycarboxylic acid polymer having a number average molecular weight of less than 5,000 and a polyol and having a pH adjusted to less than 3.5. Is disclosed.

Further, Patent Document 4 below discloses an aqueous binder for producing a glass fiber heat insulating material having an infinite water dilutability or dispersibility of an epoxy compound and an epoxy crosslinking agent.
JP-A-6-184285 Special table 2003-505538 gazette US Pat. No. 6,331,350 International Publication No. 03/104284 Pamphlet

  The formaldehyde-free binder is cured by cross-linking by amidation reaction, imidization reaction, or esterification reaction between a carboxyl group in polycarboxylic acids and an active hydrogen such as amino group, imino group, or hydroxyl group. . However, since the reaction rate is slower than the reaction between methylol groups of phenol / formaldehyde resin, it is necessary to increase the temperature of the curing oven in the binder curing process when manufacturing the inorganic fiber thermal insulation material. Moreover, it is necessary to lengthen the time of the curing process, which impairs economic efficiency and productivity. In order to improve the reaction rate, phosphorus-containing compounds such as hypophosphites are generally used as curing accelerators. However, in the case of phosphorus-containing compounds, it is necessary to lower the pH of the binder in order to accelerate the curing reaction, and curing may not be completed due to external factors. When used under high humidity, the binder deteriorates, reducing the bonding strength between inorganic fibers, causing swelling called “swelling”, and conversely shrinking in the thickness direction, maintaining the shape. And heat insulation may be impaired.

  Accordingly, an object of the present invention is to provide an aqueous binder for inorganic fibers that does not contain formaldehyde, the curing reaction proceeds rapidly and is completed in a short time, and the resulting cured binder has excellent strength, and uses the same. An object of the present invention is to provide a heat insulating sound absorbing material for inorganic fibers.

  In order to achieve the above object, the aqueous binder for inorganic fibers of the present invention comprises a curing accelerator containing at least one polycarboxylic acid containing two or more carboxyl groups in the molecule, a crosslinking agent, and bisulfites. The number of moles of the functional group capable of reacting with the carboxyl group in the crosslinking agent is 0.8 to 1.5 in terms of mole ratio with respect to the number of moles of the carboxyl group in the polycarboxylic acid. It is characterized by that.

  The aqueous binder for inorganic fibers of the present invention is made of polycarboxylic acids and is a formaldehyde-free binder, so that it does not release formaldehyde at the time of heat curing and can reduce environmental burdens in exhaust gas and the like. In addition, by using bisulfite as a curing accelerator, the heat curing of the binder can proceed relatively quickly, and the cross-linking reaction is sufficiently improved, so that the cross-linking can be made dense. it can. And by making the molar number of the functional group which can react with the carboxyl group in the said crosslinking agent into 0.8-1.5 by molar ratio with respect to the molar number of the carboxyl group in polycarboxylic acids, polycarboxylic acid is obtained. The acid and the crosslinking agent can be reacted without excess or deficiency, a strong binder cured product can be obtained, and various physical properties of the inorganic fiber heat-absorbing sound-absorbing material as the final product are not impaired.

  In the aqueous binder for inorganic fibers of the present invention, the polycarboxylic acid is preferably an acrylic resin-based polycarboxylic acid having an acid value of 350 to 850 mgKOH / g and a weight average molecular weight of 1,000 to 15,000. According to this, a cured binder having high strength is obtained, and the binding (adhesive force) between the fibers becomes strong.

  In the aqueous fiber binder for inorganic fibers of the present invention, the crosslinking agent preferably contains at least one dialkanolamine. According to this, among the functional groups contained in the crosslinking agent, the imino group reacts with the carboxyl group faster than the hydroxyl group, and further, the delay in crosslinking of the binder due to steric hindrance and the incomplete portion are reduced. The curing time can be shortened, and further, the productivity can be improved and the strength of the obtained binder cured product can be improved.

  In the aqueous fiber binder for inorganic fibers of the present invention, the curing accelerator contains at least one selected from lithium hydrogen sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, magnesium hydrogen sulfite, calcium hydrogen sulfite and ammonium hydrogen sulfite. It is preferable. According to this, the progress of the curing of the binder is accelerated, and the curing process of the binder can be simplified.

  Moreover, it is preferable that pH of the aqueous | water-based binder for inorganic fibers of this invention is adjusted to 6.0-8.0 with the volatile basic compound. The aqueous binder for inorganic fibers of the present invention can cause heat curing to proceed relatively quickly even under weakly acidic to weakly basic conditions of pH 6.0 to 8.0 by using the above-mentioned curing accelerator, In addition, since the crosslinking reaction by imidization and esterification reaction is sufficiently improved, the curing reaction proceeds quickly, and a high-strength binder cured product can be obtained, and further, there is no corrosion of production equipment due to acid. Maintenance costs, equipment costs, wastewater treatment costs, etc. can be reduced.

  On the other hand, an inorganic fiber heat-absorbing sound-absorbing material of the present invention is characterized in that the inorganic fiber-based aqueous binder of the present invention is applied to inorganic fibers and heat-cured and molded. According to this, since the formaldehyde which does not have a bad influence on an environment is not emitted at the time of manufacture, the inorganic fiber heat insulation sound-absorbing material which has little environmental load and does not impair the conventional physical property can be obtained.

  The aqueous binder for inorganic fibers of the present invention is made of polycarboxylic acids and is a formaldehyde-free binder, so that it does not release formaldehyde at the time of heat curing and can reduce environmental burdens in exhaust gas and the like. In addition, the bisulfite as a curing accelerator allows the binder to be heated and cured relatively quickly, and the crosslinking reaction is sufficiently improved, so that the crosslinking can be made dense. And by making the molar number of the functional group which can react with the carboxyl group in the said crosslinking agent into 0.8-1.5 by molar ratio with respect to the molar number of the carboxyl group in polycarboxylic acids, polycarboxylic acid is obtained. The acids and the crosslinking agent can be reacted without excess and deficiency, a strong binder cured product is obtained, and various physical properties of the inorganic fiber heat insulating sound absorbing material as the final product are not impaired.

  And the inorganic fiber heat insulation sound-absorbing material obtained by using the aqueous binder for inorganic fiber of the present invention is the thickness dimension of the heat insulation material related to the heat insulation sound-absorbing performance depending on the environmental conditions, for example, temperature or humidity, and the self-supporting property at the time of construction. It has the same physical properties as those using conventional phenolic binders, and is suitable as a core material for heat insulation, sound absorbing materials, or vacuum heat insulating materials for houses, buildings, etc. Can be used for

  The aqueous binder for inorganic fibers of the present invention is a water-soluble composition containing polycarboxylic acids containing two or more carboxyl groups in the molecule, a crosslinking agent, and a curing accelerator containing at least one bisulfite. It is a composition.

  Examples of the polycarboxylic acids used in the aqueous binder for inorganic fibers of the present invention include polycarboxylic acid monomers, polyester resin-based polycarboxylic acids, amide resin-based polycarboxylic acids, and acrylic resin-based polycarboxylic acids.

  Examples of the polycarboxylic acid monomer include aliphatic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, and tricarballylic acid. Polycarboxylic acids; oxypolycarboxylic acids such as malic acid, tartronic acid, tartaric acid, citric acid; aromatic polycarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, benzenetricarboxylic acid, trimellitic acid, and pyromellitic acid It is done.

  Examples of the polyester resin-based polycarboxylic acids include 1,2-ethanediol (ethylene glycol), 1,2-propanediol (propylene glycol), 1,3-propanediol, and 2,2-methyl-1,3-propane. Diol, 2-butyl-2-ethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-2,4-butanediol, 1,5-pentanediol, 3 -Methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hexanediol, 2-hydroxymethyl -2-Methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-2-methyl-1,3-propane Aliphatic polyols such as all, 1,2,6-hexanetriol, 2,2-bis (hydroxymethyl) -2,3-propanediol; selected from sugars such as glucose, fructose, mannitol, sorbitol, maltitol What has an acid value obtained by ester-polymerizing polyols and the said polycarboxylic acid monomer is mentioned.

  Examples of the polyamide resin-based polycarboxylic acids include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1, 6-diaminohexane, 3,3'-iminobis (propylamine), 3- (methylamino) propylamine, 3- (dimethylamino) propylamine, 3- (ethylamino) propylamine, 3- (butylamino) propyl Aliphatic polyamines such as amine, N-methyl-3,3'-iminobis (propylamine), polyethyleneimine; phenylenediamine, o-tolidine, m-toluylenediamine, m-xylylenediamine, dianisidine, diaminodiphenyl ether Aromatic polyamines such as 1,4-diaminoanthraquinone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4'-diamino-3,3'-diethyldiphenylmethane Piperazine, 2-methylpiperazine, 1- (2-aminoethyl) piperazine, 2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, bis (aminopropyl) piperazine, 1,3-di (4- A polyamine selected from heterocyclic amines such as piperidyl) propane, 3-amino-1,2,4-triazole, 1-aminoethyl-2-methylimidazole, and the polycarboxylic acid monomer. And having an acid value obtained.

  Examples of the acrylic resin-based polycarboxylic acids include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaconic acid, α-β-methyleneglutaric acid, maleic acid Monoalkyl, monoalkyl fumarate, maleic anhydride, acrylic anhydride, β- (meth) acryloyloxyethylene hydrodiene phthalate, β- (meth) acryloyloxyethylene hydrogen maleate, β- (meth) acryloyloxyethylene hydro Examples thereof include those obtained by polymerizing one or more selected from ethylenically unsaturated carboxylic acid monomers such as diene succinate.

  In the present invention, it is preferable to use acrylic resin-based polycarboxylic acids as the polycarboxylic acids. Polyester-based polycarboxylic acids and polyamide resin-based polycarboxylic acids are subjected to an exchange reaction simultaneously with crosslinking during the curing reaction with a crosslinking agent, that is, ester bonds and amide bonds in the polycarboxylic acids are cleaved by heat, Since monomers and oligomers are formed and there is a possibility that a reaction occurs in which these are recombined, the curing reaction of the binder may take time or the curing may be insufficient. In the case of acids, the above exchange reaction does not occur at the same time, so that the curing time can be shortened, and further, a sufficiently cured binder cured product can be obtained.

  The acid value of the polycarboxylic acids is preferably 350 to 850 mgKOH / g, more preferably 550 to 750 mgKOH / g. When the acid value of the polycarboxylic acid is less than 350 mgKOH / g, the crosslinked structure of the cured product obtained by heat-curing the aqueous binder tends to be rough, and the strength and rigidity of the binder cured product tend to decrease. The thickness of the inorganic fiber insulation sound-absorbing sound-absorbing material after being opened in a compressed package (hereinafter referred to as “restoration”) and the rigidity of the board are reduced, and the insulation, sound-absorbing property, or self-supporting property, ie during construction Workability may be impaired. Moreover, when the acid value of polycarboxylic acids exceeds 850 mgKOH / g, the crosslinked structure after binder curing tends to become too dense and brittle, and when used as a binder for an inorganic fiber heat-absorbing sound absorbing material, the desired performance is obtained. In the case where the unreacted carboxyl group remains in the cured product even after curing, the resulting inorganic fiber heat-absorbing sound-absorbing material absorbs moisture under high humidity, for example, and the binding force between the fiber and the fiber by the binder There may be a problem such as lowering of the image quality. The acid value of the acrylic resin-based polycarboxylic acids in the present invention is expressed in milligrams of potassium hydroxide required to neutralize 1 g of the acrylic resin-based polycarboxylic acids.

  The weight average molecular weight of the polycarboxylic acids is preferably 1,000 to 15,000, more preferably 2,000 to 10,000, and particularly preferably 2,000 to 5,000. If the weight average molecular weight of the polycarboxylic acid exceeds 15,000, the viscosity of the binder after the evaporation of water from the binder application is remarkably increased, and the fluidity after application to the inorganic fiber or after application tends to be inferior. On the other hand, it tends to be difficult to uniformly apply the binder. In addition, the adhesiveness of the binder attached to the inorganic fiber tends to increase. If the adhesiveness of the binder attached to the inorganic fiber is high, the fiber to which the binder is attached becomes more likely to adhere to the production equipment, and the production line becomes dirty. In some cases, the fiber on the surface of the heat insulating material for inorganic fibers becomes agglomerated and adheres to the production equipment, resulting in problems such as partial lack of appearance and thickness of the resulting product. On the other hand, when the weight average molecular weight of the polycarboxylic acids is less than 1,000, the binder component is easily volatilized as fume by heating at the time of curing, and the amount of the binder attached to the inorganic fibers is likely to be reduced. Therefore, when it is an inorganic fiber heat insulating sound-absorbing material, various physical properties are reduced, or it is necessary to suppress the degree of polymerization at the time of polymerization of polycarboxylic acids, so that the ethylenically unsaturated monomer tends to remain, Odor may be generated and a new environmental load may be generated. If the weight average molecular weight of the polycarboxylic acid is within the above range, the viscosity of the aqueous binder for inorganic fibers can be easily adjusted, and the fluidity at the time of application to inorganic fibers or after application can be improved. Variation in the amount of binder adhering to can be suppressed. In the production of an inorganic fiber heat-absorbing sound-absorbing material, the step of applying the binder to the fiber is often performed in a high-temperature atmosphere of about 200 to 350 ° C. immediately after being fiberized by a centrifugal method or the like. Evaporation of moisture can be improved. In addition, the weight average molecular weight of the polycarboxylic acids is related not only to the fluidity of the binder but also to the curing speed and the crosslinking density after curing. Even if the polycarboxylic acids having the same acid value have different molecular weights, The curing speed of the resin and the strength of the cured binder vary, and the physical properties of the resulting inorganic fiber heat-absorbing sound-absorbing material also change. For example, as the weight average molecular weight of polycarboxylic acids decreases, the curing rate of the binder increases, but the cured binder tends to become brittle, and depending on the production conditions of the production line, the desired physical properties may not be obtained. is there. When the weight average molecular weight of the polycarboxylic acids is within the above range, the fluidity of the binder and various physical properties of the resulting inorganic fiber heat-absorbing sound absorbing material can be optimized.

  In the present invention, the polycarboxylic acids are particularly preferably acrylic resin-based polycarboxylic acids having an acid value of 350 to 850 mgKOH / g and a weight average molecular weight of 1,000 to 15,000. In view of ease of control of the molecular weight of the acrylic resin-based polycarboxylic acids, an acrylic resin-based polycarboxylic acid using acrylic acid is preferable as the ethylenically unsaturated carboxylic acid monomer. In addition, when adjusting the acid value of the acrylic resin-based polycarboxylic acid to a high region of 700 mgKOH / g or more, the acrylic resin-based polycarboxylic acid using maleic acid or fumaric acid as the ethylenically unsaturated carboxylic acid monomer Is preferred.

  Moreover, in this invention, when adjusting the acid value of polycarboxylic acid, the ethylenically unsaturated monomer which does not contain a carboxyl group can also be used together with the said polycarboxylic acid.

  Examples of the ethylenically unsaturated monomer containing no carboxyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cetyl (meth) acrylate, n-stearyl (meth) acrylate, diethylene glycol ethoxy (meth) acrylate, methyl-3-methoxy (meth) acrylate, ethyl-3-methoxy (meth) acrylate, butyl -3-Methoxy (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 2- Droxypropyl acrylate, 4-hydroxybutyl acrylate, mono (meth) acrylate of trivalent or higher polyol, aminoalkyl (meth) acrylate, N-alkylaminoalkyl (meth) acrylate, N, N-dialkylaminoalkyl (meth) Acrylic monomers such as acrylates; Vinyl-based compounds such as vinyl alkyl ethers, N-alkyl vinyl amines, N, N-dialkyl vinyl amines, N-vinyl pyridines, N-vinyl imidazoles, N- (alkyl) aminoalkyl vinyl amines Monomer; (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide, N, N-dialkylaminoalkyl (meth) acrylamide, diacetone (meth) acrylamide, N-vinylform Amide monomers such as amide, N-vinylacetamide and N-vinylpyrrolidone; Aliphatic unsaturated hydrocarbons such as ethylene, propylene, isobutylene, isoprene and butadiene; styrene, α-methylstyrene, p-methoxystyrene, vinyl Styrene monomers such as toluene, p-hydroxystyrene, p-acetoxystyrene; vinyl ester monomers such as vinyl acetate and vinyl propionate; acrylonitrile, glycidyl (meth) acrylate and the like. These can use together 1 type (s) or 2 or more types. However, N-methylol (meth) acrylamide and methyl-N-methylol (meth) acrylamide are preferably not used since they release formaldehyde with the crosslinking reaction when heated.

  The crosslinking agent used in the aqueous binder for inorganic fibers of the present invention is a compound having a functional group capable of reacting with a carboxyl group, and preferably contains at least one dialkanolamine. In the present invention, the “functional group capable of reacting with a carboxyl group” means a hydroxyl group, an amino group, an imino group, and an epoxy group.

  Dialkanolamines are polyols having an imino group and a hydroxyl group. When the reactivity of the imino group and the hydroxyl group with respect to the carboxyl group is compared, the imino group tends to react faster than the hydroxyl group. Therefore, the reactivity with a carboxyl group can be improved by using dialkanolamines as a crosslinking agent.

  Examples of the dialkanolamines include diethanolamine, diisopropanolamine, and the like, and diethanolamine is more preferable because of the speed of reaction with polycarboxylic acids.

  Among the crosslinking agents, compounds other than dialkanolamine include (a) 1,2-ethanediol (ethylene glycol) and its dimer or trimer, 1,2-propanediol (propylene glycol) And dimer or trimer thereof, 1,3-propanediol, 2,2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,3-butane Diol, 1,4-butanediol, 2-methyl-2,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1 , 6-hexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hexanediol, 2-hydroxymethyl-2-methyl-1,3-propane Fats such as all, 2-ethyl-2-hydroxymethyl-2-methyl-1,3-propanediol, 1,2,6-hexanetriol, 2,2-bis (hydroxymethyl) -2,3-propanediol Group polyols; trialkanolamines such as triethanolamine and triisopropanolamine; sugars such as glucose, fructose, mannitol, sorbitol, maltitol, and the above polyols, and polyester polyols such as phthalic acid, adipic acid, and azelaic acid Compounds having a hydroxyl group such as polyethylene glycol, polypropylene glycol, acrylic resin polyol, (b) ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1, -Diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 3,3'-iminobis (propylamine), 3- (methylamino) propylamine, 3- (dimethylamino ) Aliphatic polyamines such as propylamine, 3- (ethylamino) propylamine, 3- (butylamino) propylamine, N-methyl-3,3′-iminobis (propylamine), polyethyleneimine; -Tolidine, m-toluylenediamine, m-xylylenediamine, dianisidine, diaminodiphenyl ether, 1,4-diaminoanthraquinone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide 4,4'-diamino-3,3'-diethyldiphenylme Aromatic polyamines such as tan; piperazine, 2-methylpiperazine, 1- (2-aminoethyl) piperazine, 2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, bis (aminopropyl) piperazine, 1, Heterocyclic amines such as 3-di (4-piperidyl) propane, 3-amino-1,2,4-triazole, and 1-aminoethyl-2-methylimidazole, and further, ethylene oxide or Compounds containing amino groups or imino groups such as polyamine polyols with propylene oxide added, (c) propanediol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, hexanediol diglycidyl ether, neopentyl Glycoldi Ricidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol polyglycidyl ether, polypropylene polyglycidyl ether, cyclohexanediol diglycidyl ether, sorbitol polyglycidyl ether adipic acid diglycidyl ester, azelaic acid diglycidyl ester, tetrahydro Aliphatic epoxies such as phthalic acid diglycidyl ester and hexahydrophthalic acid diglycidyl ester; bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, cresol phenol polyglycidyl ether, novolac phenol polyglycidyl ether, phthalic acid diglycidyl ester, etc. Contains epoxy groups such as aromatic epoxies That compound, and the like. These can use together 1 type (s) or 2 or more types.

  In the present invention, the crosslinking agent is preferably a water-soluble compound. If it is a water-insoluble compound, it is necessary to emulsify the aqueous binder for inorganic fibers. However, if it is an emulsion or aqueous dispersion binder, it will have a property of forming a film at a relatively low temperature. When producing a heat insulating sound-absorbing material for a fiber, the binder is easily formed into a film before curing. As a result, the compatibility with the polycarboxylic acids decreases, or a phenomenon occurs in which only the surface is first formed into a film and water is trapped inside, and the curing rate of the binder becomes slow, or the obtained binder curing In some cases, the physical properties of the inorganic fiber heat-absorbing sound-absorbing material may be impaired due to a decrease in strength of the object.

  The crosslinking agent is preferably a compound having a molecular weight of 50 to 500. When a crosslinking agent having a relatively high molecular weight is used, the curing rate of the binder tends to be slow. In the production process of an inorganic fiber heat-absorbing sound absorbing material, it takes time for the binder curing step or increases the temperature of the binder curing oven. Productivity and economic efficiency may be impaired.

  And in the aqueous | water-based binder for inorganic fibers of this invention, the mole number of the functional group which can react with the carboxyl group in the said crosslinking agent is 0.8 mole ratio with respect to the mole number of the carboxyl group of the said polycarboxylic acid. It is necessary to contain polycarboxylic acids and a crosslinking agent so as to be -1.5, preferably 0.9-1.2, and preferably 0.95-1.1. It is more preferable to make it contain. When the molar ratio is less than 0.8, the carboxyl group of the polycarboxylic acid remains even after the binder is cured, and when it exceeds 1.5, the crosslinking agent and the binder remain after the binder is cured. Due to environmental factors such as moisture resistance of the heat insulating sound-absorbing material, physical properties tend to decrease, excess polycarboxylic acids or cross-linking agents tend to be produced, and the economy is also inferior. If the number of moles of the functional group capable of reacting with the carboxyl group in the crosslinking agent is within the above range relative to the number of moles of the carboxyl group of the polycarboxylic acid, both the polycarboxylic acid and the crosslinking agent are crosslinked at the time of binder curing without excess or deficiency. Since the structure is formed, the strength of the cured binder is increased, and various properties of the obtained inorganic fiber heat-absorbing sound-absorbing material can be optimized.

  As a hardening accelerator used for the aqueous | water-based binder for inorganic fibers of this invention, at least 1 or more types of bisulfites are contained.

  Bisulfites are highly effective in accelerating curing reactions such as amidation reaction, imidation reaction or esterification reaction between polycarboxylic acids and cross-linking agents, and are water-soluble compounds, making them easy as aqueous binders. Can be blended.

  Examples of hydrogen sulfites include lithium hydrogen sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, magnesium hydrogen sulfite, calcium hydrogen sulfite, and ammonium hydrogen sulfite. Among them, the content of sulfite ions having a hardening promoting action is included. High lithium bisulfite, sodium bisulfite, and ammonium bisulfite are more preferable.

  In the present invention, as a curing accelerator, other curing accelerators as used in the prior art may be used in combination, and as such a curing accelerator, sodium hypophosphite is used. , Hypophosphites such as potassium hypophosphite, calcium hypophosphite and magnesium hypophosphite; organic phosphorus compounds such as tris (3-hydroxypropyl) phosphine; tetraethylphosphonium salt, triethylbenzylphosphonium salt, tetran Quaternary phosphonium salts such as -butylphosphonium salt and tri-n-butylmethylphosphonium salt; Lewis acid compounds such as boron trifluoride amine complex, zinc chloride, aluminum chloride and magnesium chloride; titanium lactate, titanium triethanolaminate, Water-soluble organometallic compounds such as zirconyl acetate . These can use together 1 type (s) or 2 or more types.

  And it is preferable that content of hydrogen sulfites in a hardening accelerator is 20-100 mass%, and 40-100 mass% is more preferable. When the content of hydrogen sulfites is 20% by mass or more, the effect of accelerating curing by the hydrogen sulfites is sufficiently exhibited.

  The content of the curing accelerator in the aqueous binder for inorganic fibers of the present invention is preferably 0.1 to 10 parts by mass in terms of solid content with respect to 100 parts by mass in total of the polycarboxylic acids and the crosslinking agent, 0.5-5 mass parts is more preferable. If the amount is less than 0.1 parts by mass, the curing reaction between the polycarboxylic acids and the crosslinking agent cannot be accelerated sufficiently. If the amount exceeds 10 parts by mass, the effect of curing acceleration commensurate with the increase in content is not observed. Since an excessive amount of bisulfite is hydrophilic, the moisture resistance and water resistance of the cured binder may be impaired.

  And as for the aqueous | water-based binder for inorganic fiber, it is preferable that pH is adjusted to 6.0-8.0 with the volatile basic compound, and it is more preferable that it is adjusted to 6.0-7.0, 6.0 to 6.5 is particularly preferable. When the pH is less than 6.0, the production equipment may be corroded due to long-term use, and there is a tendency to require wastewater treatment costs. When the pH exceeds 8.0, the crosslinking in the binder is likely to occur. The reaction becomes slow, curing is not completed, or heating for a long time is required to complete the curing, and it is easy to impair the productivity. The various physical properties are easily impaired. If the pH of the aqueous binder for inorganic fibers is within the above range, the corrosion of the production equipment can be suppressed, and the wastewater treatment can be facilitated, so that the maintenance cost can be reduced.

  Examples of the volatile basic compound used for adjusting the pH include ammonia water and amines, and it is preferable to use ammonia water in consideration of an odor generated during curing.

  In the aqueous binder for inorganic fibers of the present invention, a silane coupling agent may be further used. The silane coupling agent acts at the interface between the inorganic fiber and the binder, and can improve the adhesion of the binder to the inorganic fiber.

  Examples of silane coupling agents include γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and other aminosilane coupling agents, And epoxy silane coupling agents such as -glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyldimethoxysilane. These can use together 1 type (s) or 2 or more types.

  And as for content of a silane coupling agent, 0.1-2.0 mass parts is preferable in conversion of solid content with respect to a total of 100 mass parts of polycarboxylic acids and a crosslinking agent.

  In the aqueous binder for inorganic fibers of the present invention, at least one aqueous dispersion selected from waxes or a mixture of waxes and heavy oils may be used.

  The aqueous binder component of the present invention has better adhesion to metals compared to phenol / formaldehyde resin, so that the binder easily adheres to equipment such as a conveyor in the curing process of the binder applied to the inorganic fiber, and at the same time is inorganic. The fibers may be attached to the production equipment. As a result, irregularities are likely to occur on the surface of the resulting inorganic fiber product, and the appearance of the product may be impaired. Also, in order to remove the lump of inorganic fibers adhered to the manufacturing equipment, it is complicated at high temperatures. Work may be required and there may be problems such as loss of productivity. However, by blending the above waxes or a mixture of waxes and heavy oils into the binder, these components can be insulated with inorganic fibers. It acts as a mold release agent during the production of the sound absorbing material and can solve these problems. At the same time, the waxes or the mixture of waxes and heavy oils can remain in the binder cured product to improve the water repellency of the inorganic fiber heat-absorbing sound-absorbing material.

  The above waxes are not strictly defined, but are solids at room temperature, but when heated to about 40 ° C. or higher, they become liquids with relatively high fluidity, specifically, beeswax, Animal waxes such as lanolin wax and shellac wax, plant waxes such as carnauba wax, wax wax, rice wax and candelilla wax, mineral waxes such as montan wax and ozokerite, petroleum waxes such as paraffin wax and microcrystalline wax. And synthetic waxes such as Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polycarbonate wax, palm oil fatty acid ester, beef tallow fatty acid ester, stearamide, dipeptadecyl ketone and hardened castor oil. These can use together 1 type (s) or 2 or more types. Of these, paraffin wax, polyethylene wax, and polypropylene wax are preferred from the viewpoint of economy.

  As heavy oils, those composed of paraffin or naphthene, which are aliphatic hydrocarbons having approximately 15 to 120 carbon atoms, are used. Heavy oils have a chemical structure relatively similar to waxes and have high fluidity, and therefore act as plasticizers for waxes. Therefore, when heating to cure the aqueous binder, the fluidity of the waxes can be increased, the wax and heavy oil can be applied evenly on the inorganic fibers, and the inorganic fiber heat insulating sound absorbing material can be separated. Variations in moldability and water repellency can be suppressed.

Classification of heavy oils is carried out by the viscosity, there can be used preferably has in the region of 320mm ² / s~680mm ² / s at VG (Viscosity Grade). In heavy oils having a relatively low viscosity, for example, VG of less than 320 mm ² / s, there is a tendency for components having 30 or less carbon atoms, particularly 20 or less carbon atoms to increase, and during heating during binder curing If the viscosity is high and, for example, VG exceeds 680 mm ² / s, mixing with the dispersant during emulsification takes time, and productivity may be impaired.

  When the waxes and the heavy oils are used in combination, the mass ratio of the waxes and the heavy oils is not particularly limited, but waxes: heavy oils = 40: 60 to 95: 5. It is preferable. When the ratio of heavy oils exceeds 60% by mass, the water repellency of the water repellent increases at room temperature, resulting in a decrease in the water repellency of the resulting inorganic fiber heat-absorbing and sound-absorbing material for a long period of time. There is. On the other hand, when the ratio of heavy oils is less than 5% by mass, when using high melting point waxes, the plasticizing effect of the waxes is reduced, and the water repellency of the resulting inorganic fiber heat insulating sound absorbing material varies. May occur. Therefore, it is more preferable that the use ratio of the heavy oils is appropriately adjusted in accordance with the melting point of the waxes used or the desired water repellency.

  Generally, since waxes and heavy oils are hydrophobic materials, when adding waxes or a mixture of waxes and heavy oils to a binder, It is preferably used after being dispersed or emulsified in water.

  There are no particular restrictions on the above-mentioned waxes and dispersants for heavy oils in water, and various surfactants, water-soluble resins, etc. may be mentioned, and the type and amount of the dispersant should be set as appropriate. Is preferred.

  The content of the wax or the mixture of the wax and heavy oil is 0.1 to 5 parts by mass in terms of solid content with respect to 100 parts by mass in total of the polycarboxylic acids and the crosslinking agent. Preferably, 0.5 to 3 parts by mass is more preferable, and 0.5 to 2 parts by mass is particularly preferable. When the content is less than 0.1 parts by mass, improvement in releasability and water repellency is hardly observed, and even when the content exceeds 5.0 parts by mass, the water repellency is not improved in proportion to the increase in content. It is not preferable because it is uneconomical.

  Moreover, in the aqueous binder for inorganic fibers of the present invention, a dustproof agent, a colorant, and the like may be further added as necessary.

  The aqueous binder for inorganic fibers of the present invention is selected from the above-mentioned polycarboxylic acids, crosslinking agents, curing accelerators, and if necessary, waxes or a mixture of waxes and heavy oils. A seed water dispersion, a silane coupling agent, and the like can be prepared by mixing using a tank equipped with a stirrer such as a dissolver.

  In the most preferable embodiment of the aqueous binder for inorganic fibers according to the present invention, the polycarboxylic acid is an acrylic resin-based polycarboxylic acid having an acid value of 350 to 850 mgKOH / g and a weight average molecular weight of 1,000 to 15,000. The crosslinking agent contains at least one dialkanolamine, and the curing accelerator is selected from lithium bisulfite, sodium bisulfite, potassium bisulfite, magnesium bisulfite, calcium bisulfite and ammonium bisulfite. What contains at least 1 type and the pH of the aqueous | water-based binder for inorganic fibers is adjusted to 6.0-8.0 with the volatile basic compound is mentioned.

  Examples of the aqueous binder include emulsions, colloidal dispersions, and water-soluble compositions. However, emulsions and colloidal dispersions have poor miscibility between the dispersed resin component and water, and are water as a medium. When volatilizes, it has the characteristic that it is easy to form a film. If the resin composition in the binder forms a film before curing, the fluidity of the binder on the fiber surface is liable to be impaired, and not only an inorganic heat-insulating sound-absorbing material with a uniform amount of binder can be obtained, but also fibers. In some cases, there are many portions that are not bonded by the binder, and it is difficult to maintain the shape of the product. In addition, in colloidal dispersions and emulsions, once the medium water is volatilized and a film is formed, it is difficult to return to the aqueous material again. Tend to occur.

  On the other hand, when the aqueous binder is a water-soluble composition, since there is no film formation due to volatilization of water, the above problems do not occur. Therefore, it is preferable to prepare the aqueous binder for inorganic fibers of the present invention as a water-soluble composition.

  Here, the emulsion refers to an emulsion emulsified with an emulsifier different from the resin component, for example, a surfactant, and the colloidal dispersion refers to a material dispersed in water by a functional group in the resin component. Both are milky white in appearance. On the other hand, a water-soluble composition refers to a resin component that is completely dissolved in water, and has an appearance that is transparent or nearly transparent.

  Moreover, 5-40 mass% is preferable and, as for the solid content of the aqueous | water-based binder for inorganic fibers, 10-30 mass% is more preferable. If the solid content is less than 5% by mass, the amount of water increases, and it may take time in the curing process, which may impair the productivity. If it exceeds 40% by mass, the viscosity increases and the fluidity of the binder decreases. .

  Next, the inorganic fiber heat insulating sound absorbing material of the present invention will be described.

  The inorganic fiber heat-absorbing sound-absorbing material of the present invention is obtained by forming the above-mentioned aqueous binder for inorganic fibers on inorganic fibers and heating and curing the binder.

  The inorganic fiber heat insulating sound-absorbing material of the present invention can be produced, for example, as follows. That is, first, the molten inorganic raw material is fiberized with a fiberizing apparatus, and immediately after that, the above-mentioned aqueous binder for inorganic fibers is applied to the inorganic fibers. Next, the inorganic fiber to which the aqueous binder for inorganic fibers is applied is deposited on a perforated conveyor to form a bulky inorganic fiber heat insulating material intermediate, and the upper and lower sides are spaced so as to have a desired thickness. It feeds into a pair of perforated conveyors or the like and heats it while narrowing it, and cures the aqueous binder for inorganic fibers to form an inorganic fiber heat insulating sound absorbing material. And a skin material etc. are coat | covered as needed, and a product is obtained by cut | disconnecting the inorganic fiber heat insulation sound-absorbing material to the desired width | variety and length. Hereinafter, each step will be described in more detail.

It does not specifically limit as an inorganic fiber used for the inorganic fiber heat insulation sound-absorbing material of this invention, The glass wool, the rock wool, etc. which are used for the normal heat insulation sound absorption material can be used. Various methods such as a flame method, a blow-off method, and a centrifugal method (also referred to as a rotary method) can be used as a method for forming inorganic fibers. In particular, when the inorganic fiber is glass wool, it is preferable to use a centrifugal method. In addition, the density of the target inorganic fiber heat-insulating material may be a density used in ordinary heat-insulating materials and sound-absorbing materials, and is preferably in the range of 5 to 300 kg / m ³ .

  In order to impart the binder to the inorganic fibers, it is applied and sprayed using a spray device or the like. The amount of the binder applied can be adjusted by the same method as that for a conventional binder not containing a water repellent. The amount of the binder to be applied varies depending on the density and use of the inorganic fiber heat-absorbing sound absorbing material. Preferably, the range of 0.5-9 mass% is more preferable.

  The timing of applying the binder to the inorganic fiber sound-absorbing heat insulating material may be any time after fiberization, but in order to efficiently apply the binder, it is preferable to apply it immediately after fiberization.

  The inorganic fiber to which the binder has been applied by the above process is deposited on a perforated conveyor and becomes a bulky inorganic fiber intermediate. Here, when depositing on the perforated conveyor, it is more preferable to suck by the suction device from the opposite side of the perforated conveyor on which the inorganic fibers are deposited.

  After that, the inorganic fiber intermediate that continuously moves on the perforated conveyor is sent to a pair of upper and lower perforated conveyors and the like that are spaced so as to have a desired thickness, and at the same time, the binder is removed by heated hot air. After curing and forming the inorganic fiber heat-absorbing sound-absorbing material into a mat shape, it is cut into a desired width and length.

  Although the heat curing temperature of a binder is not specifically limited, 200-350 degreeC is preferable. Further, the heat curing time is appropriately adjusted between 30 seconds and 10 minutes depending on the density and thickness of the inorganic fiber heat-absorbing sound-absorbing material.

  The inorganic fiber heat-absorbing sound-absorbing material of the present invention may be used as it is, or may be used after being covered with a skin material. As the skin material, paper, synthetic resin film, metal foil film, non-woven fabric, woven fabric, or a combination thereof can be used.

  The inorganic fiber heat-insulating and sound-absorbing material of the present invention thus obtained does not release formaldehyde during the heat curing of the binder, and therefore has less environmental impact than conventional phenol-formaldehyde binders. is there.

  Hereinafter, the present invention will be described in more detail by way of examples. In the following description, “part” and “%” are based on mass unless otherwise specified.

<Evaluation of curability of binder>
Example 1
A resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water is 100 parts in terms of solid content. , 61.0 parts of triethanolamine as a crosslinking agent and 4.0 parts of sodium bisulfite as a curing accelerator were mixed (total molar amount of hydroxyl group of crosslinking agent / mol of carboxyl group of acrylic resin-based polycarboxylic acid). Amount = 1.0), a water-soluble composition having a pH of 3.2 was obtained, and diluted with water so that the solid content was 50%, whereby an aqueous binder for inorganic fibers of Example 1 was obtained.

(Example 2)
A resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water is 100 parts in terms of solid content. , 42.3 parts of diethanolamine as a crosslinking agent and 4.0 parts of sodium bisulfite as a curing accelerator were mixed (total molar amount of hydroxyl group and imino group of crosslinking agent / carboxyl group of acrylic resin-based polycarboxylic acid). Molar amount = 1.0) to obtain a water-soluble composition having a pH of 3.3, and diluted with water so that the solid content was 50%, whereby an aqueous binder for inorganic fibers of Example 2 was obtained.

(Example 3)
100 parts of a resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water, Mix 44.4 parts of diethanolamine as a crosslinking agent and 4.0 parts of ammonium hydrogen sulfite as a curing accelerator (total molar amount of imino group and hydroxyl group of crosslinking agent / mol of carboxyl group of acrylic resin-based polycarboxylic acid) The water-soluble composition adjusted to pH 7.0 with 25% aqueous ammonia was diluted with water so that the solid content was 50% to obtain an aqueous binder for inorganic fibers of Example 3. It was.

(Comparative Example 1)
100 parts of a resin solution (solid content 50%) in which acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved with water And 61.0 parts of triethanolamine as a crosslinking agent (total molar amount of hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin-based polycarboxylic acid = 1.0), and water solution at pH 3.3 The aqueous composition for inorganic fibers of Comparative Example 1 was obtained by diluting with water such that the solid content was 50%.

(Comparative Example 2)
A resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water is 100 parts in terms of solid content. , 61.0 parts of triethanolamine as a crosslinking agent and 4.0 parts of sodium hypophosphite as a curing accelerator (total molar amount of hydroxyl group of crosslinking agent / carboxyl group of acrylic resin-based polycarboxylic acid) The water-soluble composition having a pH of 3.2 was obtained and diluted with water so that the solid content was 50%, whereby the aqueous binder for inorganic fibers of Example 1 was obtained.

(Comparative Example 3)
A resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water is 100 parts in terms of solid content. Then, 42.3 parts of diethanolamine as a crosslinking agent was mixed (total molar amount of hydroxyl group and imino group of crosslinking agent / mol amount of carboxyl group of acrylic resin-based polycarboxylic acid = 1.0), and water-soluble at pH 3.3. An aqueous composition for inorganic fiber of Comparative Example 3 was obtained by diluting with water such that the solid content was 50%.

(Comparative Example 4)
A resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water is 100 parts in terms of solid content. 42.3 parts of diethanolamine as a crosslinking agent and 4.0 parts of sodium hypophosphite as a curing accelerator (total molar amount of hydroxyl group and imino group of crosslinking agent / carboxyl of acrylic resin-based polycarboxylic acid) Molar amount of group = 1.0) to obtain a water-soluble composition having a pH of 3.3, and diluted with water so that the solid content was 50%, whereby an aqueous binder for inorganic fibers of Comparative Example 4 was obtained. .

(Comparative Example 5)
100 parts of a resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water, 44.4 parts of diethanolamine was mixed as a crosslinking agent (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin polycarboxylic acid = 1.05), and pH 7 with 25% aqueous ammonia. The water-soluble composition adjusted to 0.0 was diluted with water so that the solid content was 50%, to obtain an aqueous binder for inorganic fibers of Comparative Example 5.

  The curing behavior of the aqueous binder for inorganic fibers of Examples 1 to 3 and Comparative Examples 1 to 5 was measured by the following method. The results are shown in FIGS.

[Evaluation of curing behavior]
The curing behavior at 150 ° C. of the binders of Examples 1 to 3 and Comparative Examples 1 to 5 was evaluated by using ARES manufactured by TA Instruments. Used as a measurement tool for the measurement tool, heated from 30 ° C to 150 ° C at 4 ° C / min, then held at 150 ° C for 60 minutes, storage modulus at a frequency of 1 rad / sec and strain of 1.0% The time change of G ′ was measured.

  In the evaluation of the curing behavior, as shown in FIGS. 1 to 3, Examples 1 to 3 are Comparative Examples 1, 3, 5 which are binders not containing a curing accelerator, and sodium phosphite as a curing accelerator. Compared with the comparative examples 2 and 4 used, it turns out that the start of hardening is quick and a storage elastic modulus becomes high in a short time. As is clear from the comparison between Example 3 and Comparative Example 5 (see FIG. 3), the pH of the binder was adjusted to 7.0 by using bisulfite as a curing accelerator. However, it can be seen that the storage elastic modulus is improved in a short time, and the time until the curing is completed can be shortened.

<Evaluation of physical properties of heat insulating material with inorganic fiber insulation>
Example 4
A resin solution (solid content 35%) in which an acrylic resin-based polycarboxylic acid (acid value 710 mgKOH / g, weight average molecular weight 14,000) composed of styrene and maleic acid is dissolved in water is crosslinked with 100 parts in terms of solid content. 59.7 parts of triethanolamine as an agent and 6.0 parts of potassium hydrogen sulfite as a curing accelerator were mixed (total molar amount of hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin-based polycarboxylic acid = 0.95) to obtain a water-soluble composition having a pH of 3.2, and after adding 0.3 part of γ-aminopropyltriethoxysilane as a silane coupling agent and stirring, the solid content was 15%. The aqueous fiber binder for Example 4 was obtained by diluting with water.

(Example 5)
100 parts of a resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water, 61.0 parts of triethanolpropane as a crosslinking agent, 15.1 parts of glycerol, and 4.0 parts of sodium bisulfite as a curing accelerator were mixed (total molar amount of hydroxyl groups in the crosslinking agent / acrylic resin-based polycarboxylic acid). The molar amount of the carboxyl group of the acid = 1.40) to obtain a water-soluble composition having a pH of 3.3. Further, 0.3 part of γ-aminopropyltriethoxysilane was added as a silane coupling agent and stirred. Then, it diluted with water so that solid content might be 18%, and the aqueous | water-based binder for inorganic fiber of Example 5 was obtained.

(Example 6)
100 parts of a resin solution (solid content 40%) obtained by dissolving an acrylic resin-based polycarboxylic acid composed of methyl acrylate and ethyl acrylate (acid value 380 mgKOH / g, weight average molecular weight 7,800) with water in terms of solid content And 26.9 parts of triethanolamine as a crosslinking agent and 4.0 parts of ammonium hydrogen sulfite as a curing accelerator (total molar amount of imino group and hydroxyl group of the crosslinking agent / acrylic resin-based polycarboxylic acid) To obtain a water-soluble composition having a pH of 3.2, and 0.2 parts of γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent. After adding and stirring, it is diluted with water so that the solid content is 15%, 4.0 parts of paraffin wax aqueous dispersion with a solid content of 40% is added, To obtain an inorganic fibrous aqueous binder for 施例 6.

(Example 7)
A resin solution (solid content 45%) in which acrylic resin-based polycarboxylic acid (acid value 710 mgKOH / g, weight average molecular weight 14,000) composed of acrylic acid, maleic acid and methyl acrylate is dissolved in water is converted into solid content. 100 parts, 42.1 parts of diethanolamine as a crosslinking agent, and 3.0 parts of lithium hydrogen sulfite as a curing accelerator (total molar amount of imino group and hydroxyl group of the crosslinking agent / acrylic resin-based polycarboxylic acid) Molar amount of carboxyl group = 0.95) to obtain a water-soluble composition having a pH of 3.3, and 0.3 parts of γ- (2-aminoethyl) aminopropyltrimethoxysilane was further added as a silane coupling agent. After stirring, the mixture is diluted with water so that the solid content becomes 15%, and an olefin wax having a solid content of 40%: a weight grade of 320 mm ² / s An aqueous dispersion for inorganic fibers of Example 7 was obtained by adding 5.0 parts of a water dispersion of quality oil = 1: 1.

(Example 8)
100 parts of a resin solution (solid content 40%) in which acrylic resin-based polycarboxylic acid (acid value 630 mgKOH / g, weight average molecular weight 24,000) composed of acrylic acid and methyl acrylate is dissolved in water, Mixing 47.2 parts of diethanolamine as a crosslinking agent and 5.0 parts of sodium hydrogen sulfite as a curing accelerator (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin = 1.20) to obtain a water-soluble composition having a pH of 3.3, and 0.2 parts of γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent was added and stirred. The aqueous binder for inorganic fibers of Example 8 was diluted with water so that the solid content was 12%, and 4.0 parts of a 40% solid content paraffin wax aqueous dispersion was added. It was obtained.

Example 9
Solid resin converted resin solution (solid content 50%) in which acrylic resin polycarboxylic acid (acid value 720 mgKOH / g, weight average molecular weight 2,800) consisting of acrylic acid, maleic acid and methyl acrylate is dissolved in water 100 parts, 66.9 parts of triethanolamine as a crosslinking agent, and 4.0 parts of sodium bisulfite as a curing accelerator (total molar amount of crosslinking agent and hydroxyl group / acrylic resin-based polycarboxylic acid) The water-soluble composition was adjusted to pH 6.5 with 25% aqueous ammonia, and 0.3 parts of γ-aminopropyltriethoxysilane was used as a silane coupling agent. Was added and stirred, diluted with water to a solid content of 15%, and 5.0 parts of a 40% solid paraffin wax aqueous dispersion was added. 9 was obtained inorganic fibers aqueous binder.

(Example 10)
Solid resin converted resin solution (solid content 50%) in which acrylic resin polycarboxylic acid (acid value 720 mgKOH / g, weight average molecular weight 2,800) consisting of acrylic acid, maleic acid and methyl acrylate is dissolved in water 100 parts, 47.2 parts of diethanolamine as a crosslinking agent, and 4.0 parts of sodium bisulfite as a curing accelerator (total molar amount of crosslinking agent and hydroxyl group / carboxyl of acrylic resin-based polycarboxylic acid) The amount of the group is 1.05), and a water-soluble composition adjusted to pH 6.5 with 25% aqueous ammonia is obtained. Further, 0.3 part of γ-aminopropyltriethoxysilane is added as a silane coupling agent. After stirring, the mixture was diluted with water so that the solid content was 15%, and 5.0 parts of a paraffin wax aqueous dispersion having a solid content of 40% was added. 0 was obtained inorganic fibers aqueous binder.

(Comparative Example 6)
100 parts of a resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water, Mixing 61.0 parts of triethanolpropane and 15.1 parts of glycerol as a crosslinking agent (total molar amount of hydroxyl groups of crosslinking agent / molar amount of carboxyl groups of acrylic resin-based polycarboxylic acid = 1.40), Obtain a water-soluble composition having a pH of 3.4, add 0.3 part of γ-aminopropyltriethoxysilane as a silane coupling agent and stir, then dilute with water so that the solid content becomes 18%. Thus, an aqueous binder for inorganic fibers of Comparative Example 6 was obtained.

(Comparative Example 7)
100 parts of a resin solution (solid content 50%) in which an acrylic resin-based polycarboxylic acid (acid value 690 mgKOH / g, weight average molecular weight 2,000) composed of acrylic acid and methyl acrylate is dissolved in water, 61.0 parts triethanolpropane as a crosslinking agent, 15.1 parts glycerol, and 6.0 parts calcium hypophosphite as a curing accelerator were mixed (total molar amount of hydroxyl groups in the crosslinking agent / acrylic resin-based poly The molar amount of the carboxyl group of the carboxylic acid = 1.40) to obtain a water-soluble composition having a pH of 2.0. Further, 0.3 part of γ-aminopropyltriethoxysilane as a silane coupling agent was added and stirred. Then, it was diluted with water so that the solid content was 18%, and an aqueous binder for inorganic fibers of Comparative Example 7 was obtained.

(Comparative Example 8)
A resin solution (solid content 45%) in which acrylic resin-based polycarboxylic acid (acid value 710 mgKOH / g, weight average molecular weight 14,000) composed of acrylic acid, maleic acid and methyl acrylate is dissolved in water is converted into solid content. 100 parts and 42.1 parts of diethanolamine as a crosslinking agent are mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin-based polycarboxylic acid = 0.95), pH 3.2 After adding 0.3 part of γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent and stirring, the solid content is 15%. Dilute with water and add olefin wax with a solid content of 40%: 5.0 parts of an aqueous dispersion of heavy oil = 1: 1 with a viscosity grade of 320 mm ² / s for comparison The aqueous binder for inorganic fibers of Example 8 was obtained.

(Comparative Example 9)
Solid resin converted resin solution (solid content 50%) in which acrylic resin polycarboxylic acid (acid value 720 mgKOH / g, weight average molecular weight 2,800) consisting of acrylic acid, maleic acid and methyl acrylate is dissolved in water 100 parts and 47.2 parts of diethanolamine as a crosslinking agent were mixed (total molar amount of hydroxyl group of crosslinking agent / molar amount of carboxyl group of acrylic resin-based polycarboxylic acid = 1.05), and 25% aqueous ammonia To obtain a water-soluble composition adjusted to pH 6.5, and after adding 0.3 part of γ-aminopropyltriethoxysilane as a silane coupling agent and stirring, the solid content is 15%. The mixture was diluted with water, and 5.0 parts of a 40% solid content paraffin wax aqueous dispersion was added to obtain an aqueous binder for inorganic fibers of Comparative Example 9.

(Comparative Example 10)
100 parts of a resol-type phenol resin precursor having a monomer content of 10% or less, a dimer of 80% or more, and a free phenol of 1% or less, dispersed in water, and γ- (2 -Aminoethyl) 0.2 parts of aminopropyltrimethoxysilane, 1.0 part of ammonium sulfate as a curing accelerator, and 450 parts of water were prepared in an open tank equipped with a dissolver, and the solid content was stirred. It diluted with water so that it might become 15%, and the aqueous binder for inorganic fibers of the comparative example 10 was obtained.

  About the inorganic fiber heat insulation sound-absorbing material using the aqueous | water-based binder for inorganic fiber of Examples 4-10 and Comparative Examples 6-10, the restorability, formaldehyde discharge | release amount, and tearing load were evaluated with the following method. The results are summarized in Table 1.

[Evaluation of resilience 1]
After applying the inorganic fiber aqueous binders of Examples 4 to 10 and Comparative Examples 6 to 10 to the glass fibers fiberized by the centrifugal method so as to have a predetermined adhesion amount, they are present while sucking with a suction device. It was deposited on a hole conveyor to form an intermediate of an inorganic fiber heat-absorbing sound absorbing material. The intermediate is heated in a 220 ° C. hot air oven for 3 minutes to cure the binder, and each of the inorganic fiber heat insulating sound absorbing materials (glass wool) having a density of 16 kg / m ³ , a thickness of 100 mm, and a binder adhesion of 3.0% is obtained. Obtained. Then, the glass wool was compressed until the thickness became 1/8, and the glass wool was inserted into a low density polyethylene bag and left in an environment of a temperature of 40 ° C. and a humidity of 95%. After 1 day, 14 days, and 28 days, the glass wool was opened, the restored thickness of the glass wool was measured, and the comparison with the initial thickness was evaluated.

[Evaluation of resilience 2]
The same operation as in Restoration Evaluation 1 was performed except that the temperature of the hot air oven was changed to 260 ° C.

[Evaluation of formaldehyde emission]
The gas generated during the curing of the glass wool binder used for the evaluation of the resilience was collected in a 4-liter odor bag, and the amount of formaldehyde released was measured using a gas detector.

  When the glass wool obtained using the phenolic binder of Comparative Example 10 was cured, 40 ppm of formaldehyde was detected, but the binder containing the acrylic resin-based polycarboxylic acid of Examples 4 to 10 and Comparative Examples 6 to 9 was used. Formaldehyde was not detected when the glass wool obtained was cured.

[Evaluation of tearing load]
After applying the inorganic fiber aqueous binders of Examples 4 to 10 and Comparative Examples 6 to 10 to the glass fibers fiberized by the centrifugal method so as to have a predetermined adhesion amount, they are present while sucking with a suction device. It was deposited on a hole conveyor to form an intermediate of an inorganic fiber heat-absorbing sound absorbing material. The intermediate is heated in hot air at 220 ° C. for 5 minutes to cure the binder, and heat insulation and absorption of inorganic fiber having a density of 32 kg / m ³ , a length of 1350 mm, a width of 430 mm, a thickness of 50 mm, and a binder adhesion of 6.0% Each material (glass wool board) was obtained. Then, the end face portion of the obtained 32 kg / m ³ glass wool board was sandwiched with a chuck of a universal testing machine in the thickness direction, and the tear load was measured at a speed of 1 m / min.

  From the above results, the inorganic fiber heat-absorbing sound-absorbing material using the inorganic fiber aqueous binders of Comparative Examples 6 to 9 had a low tear load and was not in a practical range. In addition, when the curing temperature of the binder is lowered, it can be estimated that the thickness is sag and swollen, and the curability of the binder is insufficient.

  On the other hand, the inorganic fiber heat-absorbing sound absorbing material using the inorganic fiber aqueous binder of Comparative Examples 6 to 9 has a high tear load, and even when the curing temperature of the binder is lowered, a difference in performance is observed in the resilience evaluation. The binders are excellent in curability, and in particular, Examples 7, 8, and 10 using dialkanolamine as a crosslinking agent and polycarboxylic acids have an acid value of around 700 mg KOH / g, or a weight average molecular weight of 2, The inorganic fiber heat insulating sound absorbing materials of Examples 4, 5, 7, and 10 using acrylic resin-based polycarboxylic acid of 000 to 15,000 have high tear strength, and in particular, dialkanolamine is used as a crosslinking agent. In addition, as polycarboxylic acids, an acrylic resin-based polymer having an acid value of around 700 mg KOH / g and a weight average molecular weight of 2,000 to 15,000 is used. Inorganic fiber insulation sound-absorbing material of Example 7 and 10 using the carboxylic acid was high tear strength ones.

  Since the aqueous binder for inorganic fibers of the present invention does not contain formaldehyde at all, it can be used as a binder for an inorganic fiber heat-absorbing and sound-absorbing material that has a low environmental load and can be suitably used as a heat-insulating or sound-absorbing material for houses and buildings. .

4 is a chart showing curing behavior of aqueous binders for inorganic fibers of Example 1 and Comparative Examples 1 and 2; It is a graph which shows the hardening behavior of the water-based binder for inorganic fibers of Example 2 and Comparative Examples 3 and 4. 6 is a chart showing curing behavior of aqueous binders for inorganic fibers of Example 3 and Comparative Example 5.

Claims (6)

  A polycarboxylic acid containing two or more carboxyl groups in the molecule, a crosslinking agent, and a curing accelerator containing at least one bisulfite, and the number of moles of carboxyl groups in the polycarboxylic acids On the other hand, the number of moles of the functional group capable of reacting with the carboxyl group in the crosslinking agent is 0.8 to 1.5 in a molar ratio.   The aqueous binder for inorganic fibers according to claim 1, wherein the polycarboxylic acid is an acrylic resin-based polycarboxylic acid having an acid value of 350 to 850 mgKOH / g and a weight average molecular weight of 1,000 to 15,000.   The aqueous binder for inorganic fibers according to claim 1 or 2, wherein the crosslinking agent contains at least one dialkanolamine.   The said hardening accelerator contains at least 1 sort (s) chosen from lithium hydrogen sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, magnesium hydrogen sulfite, calcium hydrogen sulfite, and ammonium hydrogen sulfite in any one of Claims 1-3. The aqueous binder for inorganic fibers as described.   The aqueous binder for inorganic fibers according to any one of claims 1 to 4, wherein the pH is adjusted to 6.0 to 8.0 with a volatile basic compound.   An inorganic fiber heat-absorbing sound-absorbing material obtained by applying the aqueous fiber binder for inorganic fibers according to any one of claims 1 to 5 to an inorganic fiber, followed by heating and curing.