JP2007211161A - Aqueous binder for inorganic fiber heat-insulating/sound-absorbing material, and inorganic fiber heat-insulating/sound-absorbing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous binder for an inorganic fiber heat-insulating/sound-absorbing material which contains no formaldehyde, cures promptly completing the curing in a short time and forms its cured product having excellent strength; and to provide the inorganic fiber heat-insulating/sound-absorbing material with use of the binder. <P>SOLUTION: The aqueous binder for the inorganic fiber heat-insulating/sound-absorbing material, contains polycarboxylic acids obtained by polymerizing an ethylenically unsaturated monomer and having 500-900 mg KOH/g acid value, and a crosslinking agent containing an alcohol having an amino group and/or an imino group. Where the molar ratio of the total number of moles of a hydroxy group, an amino group and an imino group in the crosslinking agent to the number of moles of a carboxy group in the polycarboxylic acids is 0.8-1.5; and the molar ratio of the total number of moles of an amino group and an imino group in the crosslinking agent to the number of moles of a carboxy group in the polycarboxylic acids is 0.2-0.8. The inorganic fiber heat-insulating/sound-absorbing material is molded with use of the binder. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an aqueous binder for an inorganic fiber heat-insulating material 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.

  Patent Document 2 listed below includes (a) a polyacid having at least two carboxyl groups, acid anhydride groups, or salts thereof, (b) a phosphorus-containing accelerator, (c) a hydroxy group, and a primary amino group. Containing an active hydrogen compound containing at least two active hydrogen groups selected from the group consisting of a secondary amino group and a mixture thereof, and the equivalent number of the carboxyl group, acid anhydride group, or salt thereof; The ratio of the equivalent number of active hydrogen compounds is about 1 / 0.01 to about 1/3, and the carboxyl group, acid anhydride group, or salt thereof is neutralized with a fixed base in an amount of less than about 35%. Disclosed is a method of reinforcing a cellulose substrate with a formaldehyde-free curable aqueous composition.

  Patent Document 3 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 4 listed below discloses a binder suitable for a synthetic glassy fiber containing a resin obtained by mixing a carboxylic acid and an alkanolamine under reaction conditions, and a carboxylic acid group-containing polymer. Has been.
JP-A-6-184285 Japanese Patent Laid-Open No. 7-189131 Special table 2003-505538 Special table 2004-503643 gazette

  The binder containing no formaldehyde is crosslinked by an amidation reaction, an imidization reaction, or an esterification reaction between a carboxyl group in the polycarboxylic acid and an active hydrogen such as an amino group, an imino group, or a hydroxyl group in the crosslinking agent. And harden.

  Here, the esterification reaction between the carboxyl group in the polycarboxylic acid and the hydroxyl group in the cross-linking agent has a slower reaction rate than the reaction between the methylol groups of the phenol / formaldehyde resin. In the binder curing process at the time of manufacturing the material, it is necessary to increase the temperature of the curing oven, and it is necessary to lengthen the time of the curing process, which is inferior in economic efficiency and productivity.

  On the other hand, it is known that the amidation reaction or imidation reaction by the carboxyl group in the polycarboxylic acid and the amino group or imino group in the crosslinking agent proceeds more rapidly than the esterification reaction described above. As disclosed in Patent Documents 1 to 4, various formaldehyde-free water-based binders using alkanolamine as a cross-linking agent for polycarboxylic acids have been studied.

  However, even when such a binder is used as a binder for an inorganic fiber heat-absorbing sound-absorbing material, the degree of crosslinking tends to be insufficient, and the oven temperature in the curing process can be sufficiently reduced or shortened. There wasn't.

  For example, the binder disclosed in Patent Document 1 has a molar ratio of the functional group capable of reacting with the carboxyl group to the molar number of the carboxyl group in the polyacrylic acid in a molar ratio of 0.2 to 0. As a binder for an inorganic fiber heat-absorbing sound-absorbing material, the degree of crosslinking is insufficient. Therefore, although sufficient performance can be provided as a fiber sheet or heat-resistant nonwoven fabric, sufficient physical properties as an inorganic heat insulating sound-absorbing material, such as product thickness and restored thickness when unpacked from compressed packaging, are ensured. It was difficult.

  Furthermore, since the binder disclosed in Patent Document 2 has a low content of carboxyl groups involved in the crosslinking of the emulsion polymer as a main component, the binder tends to exhibit thermoplasticity. In some cases, the binder adheres to the conveyor with inorganic fibers, or the binder at the bonding portion between the inorganic fibers tends to be lost, making it impossible to produce an inorganic fiber heat insulating sound absorbing material having a desired thickness.

  In Patent Documents 3 and 4, imino groups and carboxyl groups are reacted first in the binder preparation stage, and in the binder curing process at the time of manufacturing the inorganic fiber heat-absorbing sound absorbing material, curing is advanced only by esterification reaction. However, since imidation reaction of imino group and carboxyl group cannot be utilized, reduction of oven temperature in curing process or shortening of time is insufficient, resulting in poor economic efficiency and productivity.

  Therefore, an object of the present invention is to contain an aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material that does not contain formaldehyde, the curing reaction proceeds quickly and is completed in a short time, and the obtained binder cured product has excellent strength, and An object of the present invention is to provide an inorganic fiber heat insulating sound absorbing material using the same.

  In achieving the above object, the aqueous binder for heat insulating sound absorbers of inorganic fibers of the present invention comprises an acid value of 500 to 900 mg KOH / g polycarboxylic acid obtained by polymerizing an ethylenically unsaturated monomer, an amino group and / or an imino group. And a cross-linking agent containing an alcohol having a number of moles of a hydroxyl group, an amino group, and an imino group in the cross-linking agent with respect to the number of moles of the carboxyl group in the polycarboxylic acid is 0 in molar ratio. 0.8 to 1.5, and the total number of moles of the amino group and the imino group in the cross-linking agent with respect to the number of moles of the carboxyl group in the polycarboxylic acid is 0.2 to 0. 8 is a feature.

  The aqueous binder for an inorganic fiber heat-insulating sound absorber of the present invention is made of polycarboxylic acids and is a formaldehyde-free binder, so that it can be cured without releasing formaldehyde at the time of heat curing, Can be reduced. In addition, by using a crosslinking agent containing an alcohol having an amino group and / or an imino group, and by adding the hydroxyl group, amino group, and imino group in the crosslinking agent to the polycarboxylic acids so as to have the above molar ratio. The heat curing of the binder can be rapidly advanced, and the inorganic fiber heat insulating sound absorbing material can be manufactured without increasing the temperature of the curing oven and lengthening the time of the curing process. Furthermore, since the crosslinking reaction is also sufficiently improved, the crosslinking can be made dense, and an inorganic fiber heat-absorbing and sound-absorbing material having sufficient physical properties can be obtained.

  In the aqueous binder for heat-absorbing material for inorganic fibers of the present invention, the polycarboxylic acids preferably have 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.

  Moreover, in the aqueous binder for an inorganic fiber heat-absorbing and sound-absorbing material of the present invention, it is preferable that the crosslinking agent 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.

  Moreover, in the aqueous binder for an inorganic fiber heat-absorbing and sound-absorbing material of the present invention, the curing accelerator is preferably contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the polycarboxylic acids and the crosslinking agent. . 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 0.1-5 mass parts of ammonium sulfate is contained with respect to a total of 100 mass parts of the said polycarboxylic acids and the said crosslinking agent in the aqueous | water-based binder for inorganic fiber heat-insulating acoustic materials of this invention. According to this, since the alkali component eluted from the inorganic fiber can be neutralized and the hydrolysis of the binder cured product can be suppressed, the physical properties of the inorganic fiber heat-insulating sound absorbing material are deteriorated due to environmental factors such as high humidity. Can be prevented.

  Moreover, in the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention, one aqueous dispersion selected from waxes or a mixture of waxes and heavy oils is obtained by combining the polycarboxylic acids and the crosslinking agent. It is preferable to contain 0.1-5 mass parts in conversion of solid content with respect to a total of 100 mass parts. The above-mentioned waxes, or a mixture of waxes and heavy oils, acts as a release agent, dustproof agent, or water repellent agent that suppresses adhesion to production equipment during the production of an inorganic fiber heat-absorbing sound absorbing material. In particular, the polycarboxylic acid-based binder has better adhesion to metal compared to the phenol / formaldehyde resin-based binder, so it easily adheres to the binder cured characters with inorganic fibers on a metal conveyor, Although productivity may be impaired, releasability can be imparted to the binder by using the above waxes or a mixture of waxes and heavy oils, and the above problems can be prevented.

  Moreover, in the aqueous binder for an inorganic fiber heat-absorbing and sound-absorbing material of the present invention, the silane coupling agent may be contained in an amount of 0.1 to 2 parts by mass with respect to a total of 100 parts by mass of the polycarboxylic acids and the crosslinking agent. preferable. According to this, the silane coupling agent can improve the adhesiveness in the interface of an inorganic fiber and a binder, and can improve each physical property of the inorganic fiber heat insulating sound-absorbing material obtained.

  On the other hand, the inorganic fiber heat-absorbing and sound-absorbing material of the present invention is characterized in that the above-mentioned aqueous binder for inorganic fiber and heat-absorbing and sound-absorbing material is imparted to inorganic fibers and heat-cured and molded. According to this, since the formaldehyde which does not have an unfavorable influence on the environment is not released at the time of production, an inorganic fiber heat insulating sound absorbing material which has little environmental load and does not impair the conventional physical properties can be obtained.

  The aqueous binder for heat-absorbing material for inorganic fibers of the present invention is composed of polycarboxylic acids and is a formaldehyde-free binder, so that it can be cured without releasing formaldehyde at the time of heat curing, and in the exhaust gas etc. Can be reduced. In addition, by using a crosslinking agent containing an alcohol having an amino group and / or an imino group, and by adding the hydroxyl group, amino group, and imino group in the crosslinking agent to the polycarboxylic acids so as to have the above molar ratio. The heat curing of the binder can be rapidly advanced, and the inorganic fiber heat insulating sound absorbing material can be manufactured without increasing the temperature of the curing oven and lengthening the time of the curing process. Furthermore, since the crosslinking reaction is also sufficiently improved, the crosslinking can be made dense, and an inorganic fiber heat-absorbing and sound-absorbing material having sufficient physical properties can be obtained.

  And the inorganic fiber heat insulation sound-absorbing material obtained by using the aqueous binder for inorganic fiber heat-absorbing sound absorption material of the present invention is the thickness dimension of the heat insulation material related to the heat insulation sound absorption performance depending on environmental conditions, for example, temperature or humidity, It has the same physical properties as those using conventional phenolic binders, without lowering the rigidity related to the self-supporting property, and is a heat insulating material for houses and buildings, a sound absorbing material, or a core material for vacuum heat insulating materials. Can be suitably used.

  The aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention contains polycarboxylic acids having an acid value of 500 to 900 mgKOH / g obtained by polymerizing an ethylenically unsaturated monomer, and an alcohol having an amino group and / or an imino group. It is a water-soluble composition containing a crosslinking agent.

  The polycarboxylic acid used in the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention is one or more monomers selected from ethylenically unsaturated carboxylic acid monomers, either alone or ethylenically containing no carboxyl group. It is obtained by polymerization using an unsaturated monomer in combination.

  Examples of the ethylenically unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaconic acid, α-β-methyleneglutaric acid. , Monoalkyl maleate, monoalkyl fumarate, maleic anhydride, acrylic anhydride, β- (meth) acryloyloxyethylene hydrodiene phthalate, β- (meth) acryloyloxyethylene hydromaleate, β- (meth) acryloyl Examples thereof include oxyethylene hydrogen succinate.

  Considering the ease of controlling the molecular weight of the polycarboxylic acids, it is preferable to use acrylic acid. Moreover, when adjusting the acid value of polycarboxylic acid to the high area | region of 780 mgKOH / g or more, it is preferable to use maleic acid or fumaric 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 not used because they cause a crosslinking reaction and release formaldehyde when heated.

  The acid value of the polycarboxylic acids needs to be 500 to 900 mgKOH / g, preferably 600 to 900 mgKOH / g, and more preferably 650 to 900 mgKOH / g. When the acid value of the polycarboxylic acid is less than 500 mgKOH / g, the crosslinked structure of a cured product obtained by heat-curing the aqueous binder becomes rough, and the strength and rigidity of the binder cured product tend to be reduced. Therefore, the inorganic fiber heat insulating sound-absorbing material obtained using this binder is reduced in thickness restoration after opening the compressed package (hereinafter referred to as “restoration”), rigidity as a board is reduced, heat insulation, sound absorption, Or independence, ie, workability | operativity at the time of construction may be impaired. On the other hand, if the acid value of the polycarboxylic acid exceeds 900 mgKOH / g, the crosslinked structure after curing the binder tends to be too dense and brittle. Therefore, an inorganic fiber heat-absorbing sound-absorbing material obtained by using this binder has unreacted carboxyl groups remaining in the cured product even when it does not reach the desired performance, or after curing, for example, absorbs moisture under high humidity. As a result, there may be a problem that the bonding force between the fibers due to the binder is reduced. In the present invention, the acid value of polycarboxylic acids is expressed in milligrams of potassium hydroxide required to neutralize 1 g of 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. When 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 is poor and uniform with respect to the inorganic fiber. It becomes difficult to apply the binder. In addition, binders attached to inorganic fibers tend to be more tacky, so the fibers to which the binders are attached are more likely to adhere to the production equipment, and dirt on the production line and fibers on the surface of the inorganic fiber heat-absorbing sound absorber are agglomerated. Thus, there are cases where problems such as partial adhesion of the appearance and thickness dimension of the product obtained due to adhering to the manufacturing equipment are caused. On the other hand, when the weight average molecular weight of the polycarboxylic acid 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 fiber 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 polycarboxylic acids is related not only to the fluidity of the binder but also to the crosslinking density after curing. Even if the polycarboxylic acids having the same acid value have different molecular weights, the strength of the cured binder Fluctuates, 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 cured binder tends to be brittle, and the desired physical properties may not be obtained. However, if the weight average molecular weight of the polycarboxylic acids is within the above range, It is possible to optimize the fluidity of the binder and various physical properties of the obtained inorganic fiber heat-absorbing sound-absorbing material.

  The crosslinking agent used for the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention contains at least an alcohol having an amino group and / or an imino group.

  Examples of the functional group that can react with the carboxyl group of the polycarboxylic acid to form a crosslink include an amino group, an imino group, a hydroxyl group, an epoxy group, and a methylol group.

  From the viewpoint of the reaction rate with the carboxyl group, the hydroxyl group is the slowest functional group among the functional groups.

  On the other hand, it has advantages and disadvantages with a relatively fast functional group. For example, a methylol group has a high possibility of releasing formaldehyde in the reaction with a carboxyl group and does not meet the object of the present invention.

  In addition, the epoxy group is poor in affinity with water, and when using a crosslinking agent containing an epoxy group in an aqueous binder, the crosslinking agent is made into an aqueous dispersion or other hydrophilic groups in the molecular structure. It is necessary to contain. Since this aqueous dispersion has high film-forming properties at low temperatures, the film is formed before the binder is cured, and the cross-linking agent in the binder becomes non-uniform. In addition, binder formation in the inorganic fiber heat-absorbing and sound-absorbing material manufacturing equipment, particularly the cotton collecting process before the curing process may become prominent due to film formation, and the productivity and physical properties of the inorganic fiber heat-absorbing and sound-absorbing material are lowered. Further, introduction of other hydrophilic groups into the molecular structure may impair the water resistance of the binder. Furthermore, the epoxy group may be ring-opened in water and changed to a hydroxyl group depending on the pH of the binder, and it is difficult to ensure stable productivity and quality.

  Examples of the compound having an amino group or imino group include amines, but amines generally have an odor problem, and are amines that are crosslinking agents in the binder preparation step or the production of an inorganic fiber heat-absorbing sound absorbing material. Volatilizes and causes new environmental loads such as odor.

  In the present invention, an alcohol having an amino group and / or an imino group is used as a crosslinking agent. The alcohol contains an amino group and / or imino group and a hydroxyl group in the molecule, thereby reducing the vapor pressure or increasing the boiling point, and can suppress the environmental load caused by odors such as amines. In addition, since the molecule contains an amino group and / or imino group that reacts with a carboxyl group more rapidly than a hydroxyl group, the curing oven temperature during the production of an inorganic fiber heat-absorbing sound absorbing material is reduced, the curing time is shortened, or the binder is crosslinked. By improving the degree, the productivity and physical properties of the inorganic fiber heat-absorbing sound-absorbing material can be improved.

  Examples of the alcohol include alkanolamines such as ethanolamine, isopropanolamine, diethanolamine, and diisopropanolamine; aliphatic polyamines [eg, 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- (dimethyl Amino) propylamine, 3- (ethylamino) propylamine, 3- (butylamino) propylamine, N-methyl-3,3′-iminobis (propylamine), polyethyleneimine, etc.], aromatic polyamine [For example, phenylenediamine, o-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′-diethyldiphenylmethane, etc.], heterocyclic amines [eg piperazine, 2-methylpiperazine, 1- (2-aminoethyl) piperazine, 2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, bis (aminopropyl) piperazine, 1,3-di (4-piperidyl) propane, 3-amino-1,2,4-triazole, 1-amino Such as ethyl-2-methylimidazole], ethylene oxide, or Polyamine polyol obtained by adding propylene oxide.

  In the present invention, it is preferable to contain at least one kind of dialkanolamines such as diethanolamine and diisopropanolamine as a crosslinking agent.

  The dialkanolamines have a low molecular weight compared to the above polyamine-based polyol, but have a boiling point of 200 ° C. or higher, so that they have high reactivity with polycarboxylic acids, and are suitable for the production of an inorganic fiber heat insulating material. There is little volatilization in the curing process and it is economical.

  Moreover, the aqueous binder for an inorganic fiber heat-absorbing and sound-absorbing material of the present invention may further use a polyol other than the alcohol as a crosslinking agent.

  Such a polyol is not particularly limited, but is preferably a water-soluble polyol. Specifically, 1,2-ethanediol (ethylene glycol) and its dimer or trimer, 2-propanediol (propylene glycol) and its dimer or trimer, 1,3-propanediol, 2,2-methyl-1,3-propanediol, 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- -Methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-2-methyl-1,3-propanediol, 1,2,6-hexanetriol, 2,2-bis (hydroxymethyl) -2 Aliphatic polyols such as 1,3-propanediol; trialkanolamines such as triethanolamine and triisopropanolamine; sugars such as glucose, fructose, mannitol, sorbitol, maltitol, and the above polyols, phthalic acid, and adipine Examples thereof include polyester polyols such as acid and azelaic acid, polyethylene glycol, polypropylene glycol, and acrylic resin-based polyol. These can use together 1 type (s) or 2 or more types. Of these, trialkanolamines are preferred because they have a high boiling point and are difficult to volatilize.

  In the aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material of the present invention, the total number of moles of hydroxyl groups, amino groups and imino groups in the crosslinking agent is 0 in terms of mole ratio relative to the number of moles of carboxyl groups in the polycarboxylic acids. The polycarboxylic acids and the crosslinking agent are contained so that the total number of moles of the amino group and the imino group in the crosslinking agent is 0.2 to 0.8. There is a need.

  When the total number of moles of hydroxyl groups, amino groups, and imino groups in the crosslinking agent with respect to the number of moles of carboxyl groups in the polycarboxylic acids is less than 0.8 in terms of mole ratio, the carboxyl groups of the polycarboxylic acids are binders It tends to remain after curing. On the other hand, if it exceeds 1.5, the crosslinking agent remains unreacted even after the binder is cured, so that the physical properties deteriorate due to environmental factors such as moisture resistance of the obtained inorganic fiber heat-absorbing sound absorbing material, or excess poly Carboxylic acids or cross-linking agents are likely to be produced, resulting in poor economic efficiency. If the total number of hydroxyl groups, amino groups, and imino groups in the crosslinking agent relative to the number of moles of carboxyl groups in the polycarboxylic acid is within the above range, both the polycarboxylic acid and the crosslinking agent can be cured without excess or deficiency. Since a crosslinked structure is sometimes formed, the strength of the binder cured product becomes strong, and various physical properties of the obtained inorganic fiber heat-absorbing and sound-absorbing material can be optimized.

  Further, when the total number of moles of the amino group and the imino group in the crosslinking agent with respect to the number of moles of the carboxyl group in the polycarboxylic acid is less than 0.2 in terms of mole ratio, And the hydroxyl group becomes dominant, and it becomes difficult to lower the curing oven temperature and shorten the curing time in the curing step when producing the inorganic fiber heat-absorbing sound-absorbing material. On the other hand, when it exceeds 0.8, amide bonds and imide bonds having high hydrophilicity are increased during binder crosslinking, and the physical properties deteriorate due to environmental factors such as moisture resistance of the obtained inorganic fiber heat-absorbing sound-absorbing material. If the total number of moles of amino groups and imino groups in the cross-linking agent with respect to the number of moles of carboxyl groups in the polycarboxylic acid is within the above range, the curing of the binder proceeds rapidly, and the inorganic fiber heat insulating sound absorbing material is produced. It is possible to improve the productivity by relaxing or shortening the curing conditions at the time, and to optimize the physical properties of the obtained inorganic fiber heat insulating material.

  In the aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material of the present invention, the total number of moles of hydroxyl groups, amino groups and imino groups in the cross-linking agent with respect to the number of moles of carboxyl groups in the polycarboxylic acids is 0. It is preferable to contain so that it may become 9-1.2, and it is more preferable to contain so that it may become 0.95-1.1.

  The total number of moles of the amino group and imino group in the crosslinking agent with respect to the number of moles of the carboxyl group in the polycarboxylic acid is preferably 0.25 to 0.8. It is more preferable to make it contain so that it may become 3-0.7.

  As the curing accelerator used in the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention, an amidation reaction or an imidation reaction between a carboxyl group of the polycarboxylic acid and an amino group, imino group or hydroxyl group in the crosslinking agent Or what promotes esterification reaction is mentioned, A water-soluble compound is preferable.

  Examples of such curing accelerators include hypophosphites such as sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite; and organic phosphorus such as tris (3-hydroxypropyl) phosphine. Compounds; quaternary phosphonium salts such as tetraethylphosphonium salt, triethylbenzylphosphonium salt, tetra n-butylphosphonium salt, tri n-butylmethylphosphonium salt; boron trifluoride amine complex, zinc chloride, aluminum chloride, magnesium chloride, etc. Lewis acid compounds; water-soluble organometallic compounds such as titanium lactate, titanium triethanolamate, and zirconyl acetate. These can use together 1 type (s) or 2 or more types. Among them, calcium hypophosphite and tris (3-hydroxypropyl) phosphine have a high curing acceleration effect even in a small amount, and even if they remain in the binder cured product, they hardly impair the moisture resistance of the binder cured product. preferable.

  And it is preferable that it is 0.1-10 mass parts with respect to a total of 100 mass parts of the said polycarboxylic acids and the said crosslinking agent, and, as for content of a hardening accelerator, 1-5 mass parts is more preferable. When the content of the curing accelerator is less than 0.1 parts by mass, the effect of promoting curing is hardly recognized, and when the content exceeds 10 parts by mass, the effect of promoting curing with respect to the added amount is not observed, This is economical, and may remain in the cured binder and impair the water resistance of the cured binder.

  The aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of the present invention preferably further contains ammonium sulfate.

  The aqueous binder for heat insulating sound absorbers of inorganic fibers of the present invention reacts with polycarboxylic acids and a crosslinking agent containing an alcohol having an amino group and / or an imino group to form an amide bond, an imide bond or an ester bond. However, since the above bond is easily hydrolyzed by the alkali component eluted from the inorganic fiber, the bond strength between the inorganic fibers of the binder may be reduced in the use of the inorganic fiber heat-absorbing sound absorbing material over time.

  On the other hand, when ammonium sulfate is blended in the binder composition, ammonium ions are volatilized as ammonia by heating in the binder curing step and remain in the binder as an acid. For this reason, by containing ammonium sulfate, it is possible to neutralize the alkaline component eluted from the inorganic fiber, and as a result, it is possible to suppress the hydrolysis of the cross-linked portion in the binder, so that various properties of the inorganic fiber heat-absorbing sound absorbing material can be maintained for a long period of time. .

  And 0.1-5 mass parts is preferable with respect to a total of 100 mass parts of polycarboxylic acids and a crosslinking agent, and, as for content of ammonium sulfate, 1-3 mass parts is more preferable. When the amount is less than 0.1 parts by mass, the effect of neutralizing the eluted alkaline component is insufficient. When the amount exceeds 5 parts by mass, the amount is excessive to neutralize the eluted alkaline component. Water resistance may be impaired.

  The aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material of the present invention preferably further contains at least one water dispersion selected from waxes or a mixture of waxes and heavy oils.

  In general, polycarboxylic acids have better adhesion to metals than phenol / formaldehyde resins, so in the curing process of binders applied to inorganic fibers, binders easily adhere to equipment such as conveyors, and at the same time inorganic fibers May adhere to the manufacturing equipment. As a result, it is easy to cause irregularities on the surface of the resulting inorganic fiber product, which tends to impair the appearance of the product, and to remove the lump of inorganic fibers adhered to the manufacturing equipment, so that complicated work at high temperatures However, by blending the above waxes or a mixture of waxes and heavy oils into a binder, these components can be used as an inorganic fiber heat-absorbing sound absorbing material. It acts as a mold release agent during production 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 that is 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 reduced.

Classification of heavy oils is carried out by the viscosity, VG (Viscosity Grade) which in the region of 320mm ² / s~680mm ² / s at that, can be preferably used in the present invention. In heavy oils having a relatively low viscosity, for example, VG of less than 320 mm ² / s, components having a carbon number of 30 or less, in particular, a carbon number of 20 or less tend to increase. When it becomes easy to volatilize and the viscosity is high, for example, VG exceeds 680 mm ² / s, it takes time to mix with the dispersant when emulsifying, which may impair productivity.

  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.

  The aqueous binder for heat insulation of inorganic fibers of the present invention preferably further contains a silane coupling agent. 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.

  When an aminosilane coupling agent is used, if it is added directly to the aqueous binder for insulating inorganic fibers, hydrolysis and condensation reaction of the silane site may occur, and a white water-insoluble material may be generated. It is preferable that the ring agent is dissolved in water in advance and then added after ammonia water or the like is added to adjust the alkalinity to hydrolyze the silane site.

  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. If it is less than 0.1 parts by mass, the effect of the silane coupling agent is hardly recognized, and even if it exceeds 2.0 parts by mass, the adhesiveness does not improve in proportion to the increase in content, which is uneconomical. This is not preferable.

  Moreover, in the aqueous | water-based binder for inorganic fiber heat insulation materials of this invention, you may further add various additives, such as a dustproof agent and a coloring agent, as needed.

  The aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material of the present invention is selected from the above polycarboxylic acids, a crosslinking agent, a curing accelerator, and if necessary, a wax or a mixture of waxes and heavy oils. One type of water dispersion, silane coupling agent, and the like can be prepared by mixing using a tank equipped with a stirrer such as a dissolver.

  As the most preferable embodiment of the aqueous binder for heat insulating and absorbing material for inorganic fibers of the present invention, the polycarboxylic acids are polycarboxylic acids having an acid value of 500 to 900 mg KOH / g obtained by polymerizing an ethylenically unsaturated monomer, and the crosslinking agent is , Containing at least one dialkanolamine, and the curing accelerator is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the polycarboxylic acids and the crosslinking agent, and the polycarboxylic acids The total number of moles of hydroxyl groups, amino groups, and imino groups in the crosslinking agent is 0.8 to 1.5 in terms of mole ratio relative to the number of moles of carboxyl groups in the crosslinking agent, and the carboxyls in the polycarboxylic acids The total number of moles of the amino group and the imino group in the crosslinking agent is 0.2 to 0.8 in terms of mole ratio relative to the number of moles of the group.

  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 components and water, and water as a medium is volatilized. Then, 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 an inorganic fiber heat-absorbing sound absorbing material 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 heat insulation materials 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. .

  In addition, the pH of the aqueous binder for an inorganic fiber heat-absorbing sound-absorbing material is not particularly limited because it is determined by the course of preparation, but it is acidic because it contains polycarboxylic acids, and the pH is about 3-5.

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

  The inorganic fiber heat insulating sound-absorbing material of the present invention is obtained by applying the above-mentioned aqueous binder for an inorganic fiber heat-absorbing sound absorbing material to 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 made into a fiber by a fiberizing apparatus, and immediately after that, the binder is applied to the inorganic fiber. Next, a pair of upper and lower perforated holes are formed so as to form a bulky inorganic fiber heat insulating material intermediate by depositing inorganic fibers provided with a binder on a perforated conveyor and having a desired thickness. It is fed into a conveyor or the like and heated while being narrowed to cure the binder, thereby forming 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 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is 100 parts in terms of solid content, and 48 ethanol is used as a crosslinking agent. 0.0 part is mixed (total molar amount of imino group and hydroxyl group of cross-linking agent / mol amount of carboxyl group of polycarboxylic acid = 1.0, molar amount of imino group of cross-linking agent / mol of carboxyl group of polycarboxylic acid) (Amount = 0.33) was diluted with water so that the solid content was 50%, to obtain an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 1.

(Example 2)
A resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is 100 parts in terms of solid content, and 48 ethanol is used as a crosslinking agent. 0.0 part and 4.0 parts of sodium hypophosphite as a curing accelerator are mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.0, crosslinking Inorganic fiber heat insulation of Example 2 by diluting a water-soluble composition obtained by adding a molar amount of imino groups of the agent / a molar amount of carboxyl groups of the polycarboxylic acids = 0.33) to a solid content of 50%. An aqueous binder for sound absorbing material was obtained.

(Example 3)
As a polycarboxylic acid, a resin solution (solid content 40%) in which a polycarboxylic acid composed of styrene and maleic acid (acid value 890 mgKOH / g, weight average molecular weight 14,000) is dissolved in water is 100 parts in terms of solid content. And 44.4 parts of diethanolamine as a crosslinking agent (total molar amount of hydroxyl group and imino group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 0.8, molar amount of imino group of crosslinking agent / poly A water-soluble composition having a carboxyl group of carboxylic acids = 0.27) was diluted with water so as to have a solid content of 50%, whereby an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 3 was obtained.

(Comparative Example 1)
100 parts of a resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is converted into solid content, and triethanolamine is used as a crosslinking agent. Was diluted with water so that the solid content was 50%. 68.1 parts of the above mixture was mixed (molar amount of the hydroxyl group of the crosslinking agent / molar amount of the carboxyl group of the polycarboxylic acid = 1.0). Thus, an aqueous binder for inorganic fibers of Comparative Example 1 was obtained.

(Comparative Example 2)
100 parts of a resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is converted into solid content, and triethanolamine is used as a crosslinking agent. 68.1 parts and 4.0 parts of sodium hypophosphite as a curing accelerator were mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.0). The water-soluble composition was diluted with water so that the solid content was 50%, and an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Comparative Example 2 was obtained.

(Comparative Example 3)
As a polycarboxylic acid, a resin solution (solid content 40%) in which a polycarboxylic acid composed of styrene and maleic acid (acid value 890 mgKOH / g, weight average molecular weight 14,000) is dissolved in water is 100 parts in terms of solid content. , 30.5 parts of diethanolamine and 26.8 parts of glycerol as a crosslinking agent (total molar amount of hydroxyl group and imino group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.1, crosslinking agent) The aqueous composition for inorganic fibers of Comparative Example 3 was diluted with water so that the solid content was 50%. A binder was obtained.

[Evaluation of curing behavior]
The curing behavior at 150 ° C. of the binders of Examples 1 to 3 and Comparative Examples 1 to 3 was evaluated by using an ARES manufactured by TA Instruments. The measurement jig is used for 25 mm diameter quettes, heated from 30 ° C. to 150 ° C. at 4 ° C./min, then held at 150 ° C., storage frequency G at a measurement frequency of 1 rad / s and strain of 1%. The time change of 'was measured, and the results are shown in FIGS.

In the evaluation of the curing behavior, Example 1 and Comparative Example 1, and Example 3 and Comparative Example 3 do not contain a curing accelerator, and the difference in the curing behavior of the binder due to the difference in the crosslinking agent can be observed. it can. When Examples 1 and 3 are compared with Comparative Examples 1 and 3, it can be seen that the aqueous binders of Examples 1 and 3 start curing quickly and have a high storage elastic modulus in a short time. Further, Example 2 and Comparative Example 2 each contain a curing accelerator, but even when these are compared, the binder of Example 2 is shorter in time and has a higher elastic modulus. It can be seen that
Thereby, it turns out that the storage elastic modulus improves the binder of this invention in a short time, and can shorten the time to completion of hardening.

<Evaluation of physical properties of heat insulating material with inorganic fiber insulation>
Example 4
A resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is 100 parts in terms of solid content, and 48 ethanol is used as a crosslinking agent. 0.0 part and 6.0 parts of calcium hypophosphite as a curing accelerator were mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.0, A water-soluble composition having a molar amount of imino group / a molar amount of carboxyl group of polycarboxylic acids = 0.33) was obtained. Furthermore, as a silane coupling agent, an aqueous solution in which γ-aminopropyltriethoxysilane was dissolved in water and adjusted to pH 8.5 with aqueous ammonia was added so that the aminosilane coupling component was 0.3 parts and stirred. Then, it was diluted with water so that the solid content was 15%, and the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 4 was obtained.

(Example 5)
As a polycarboxylic acid, a resin solution (solid content 50%) in which a polycarboxylic acid composed of acrylic acid and methyl acrylate (acid value 530 mgKOH / g, weight average molecular weight 2,000) is dissolved in water is 100 parts in terms of solid content. , 27.8 parts diethanolamine and 16.2 parts glycerol as a crosslinking agent and 4.0 parts sodium hypophosphite as a curing accelerator (total molar amount of imino group and hydroxyl group of the crosslinking agent / poly A molar amount of carboxylic acid carboxyl group = 1.40, a molar amount of imino group of the crosslinking agent / a molar amount of polycarboxylic acid carboxyl group = 0.28) was obtained. Further, as a silane coupling agent, an aqueous solution in which γ-aminopropyltriethoxysilane was dissolved in water and adjusted to pH 8.5 with aqueous ammonia was added so that the aminosilane coupling component was 0.4 parts. After stirring, it is diluted with water so that the solid content becomes 18%, and 4.0 parts of paraffin wax aqueous dispersion with a solid content of 40% is further added. An aqueous binder was obtained.

(Example 6)
As a polycarboxylic acid, a resin solution (solid content 40%) in which a polycarboxylic acid composed of styrene and maleic acid (acid value 890 mgKOH / g, weight average molecular weight 14,000) is dissolved in water is 100 parts in terms of solid content. And 44.4 parts of diethanolamine as a crosslinking agent (total molar amount of hydroxyl group and imino group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 0.8, molar amount of imino group of crosslinking agent / poly A water-soluble composition in which the molar amount of carboxyl groups of carboxylic acids = 0.27) was obtained. Further, an aqueous solution prepared by dissolving γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent in water and adjusting the pH to 8.5 with aqueous ammonia becomes 0.4 parts of aminosilane coupling component. And then diluted with water so that the solid content becomes 15%, and 4.0 parts of paraffin wax aqueous dispersion having a solid content of 40% is added. An aqueous binder for the material was obtained.

(Example 7)
As a polycarboxylic acid, a resin solution (solid content 50%) in which a polycarboxylic acid composed of acrylic acid and methyl acrylate (acid value 710 mg KOH / g, weight average molecular weight 5,000) is dissolved in water is 100 parts in terms of solid content. , 53.3 parts of diisopropanolamine as a crosslinking agent and 3.0 parts of tris (3-hydroxypropyl) phosphine as a curing accelerator (total molar amount of imino group and hydroxyl group of the crosslinking agent / polycarboxylic acids) The molar amount of carboxyl group = 0.95, the molar amount of imino group of the crosslinking agent / the molar amount of carboxyl group of the polycarboxylic acid = 0.32) was obtained, and γ was used as the silane coupling agent. -(2-aminoethyl) aminopropyltrimethoxysilane was dissolved in water and an aqueous solution adjusted to pH 8.5 with aqueous ammonia was added. After aminosilane coupling component is added and stirred so as to 0.3 parts, solid content was diluted with water so that 15%, 40% solids olefin wax: the viscosity grade of 320 mm 2 / ^s An aqueous dispersion for an inorganic fiber heat-absorbing material of Example 7 was obtained by adding 5.0 parts of a heavy oil = 1: 1 aqueous dispersion.

(Example 8)
100 parts of a resin solution (solid content 50%) in which polycarboxylic acid composed of acrylic acid and methyl acrylate (acid value 710 mgKOH / g, weight average molecular weight 5,000) is dissolved in water as a polycarboxylic acid in terms of solid content And 58.0 parts of a polyamine polyol obtained by adding 2 moles of ethylene oxide to 1 mole of diethylenetriamine as a crosslinking agent and 3.0 parts of calcium hypophosphite as a curing accelerator (the imino group and hydroxyl group of the crosslinking agent) (A total molar amount / a molar amount of carboxyl group of polycarboxylic acid = 1.20, a molar amount of imino group of crosslinking agent / a molar amount of carboxyl group of polycarboxylic acid = 0.72) Further, γ- (2-aminoethyl) aminopropyltrimethoxysilane is dissolved in water as a silane coupling agent, A) After adding an aqueous solution adjusted to pH 8.5 with water so that the aminosilane coupling component is 0.3 parts, the solution is diluted with water so that the solid content is 15%, and the solid content is 40%. Olefin wax: 5.0 parts of a water dispersion of a heavy oil = 1: 1 heavy oil having a viscosity grade of 320 mm ² / s was added to obtain an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 8.

Example 9
As a polycarboxylic acid, a resin solution (solid content 40%) in which a polycarboxylic acid (acid value 720 mgKOH / g, weight average molecular weight 17,500) composed of acrylic acid, maleic acid and methyl acrylate is dissolved in water is solid. 100 parts by weight, 49.4 parts of diethanolamine as a crosslinking agent, and 4.0 parts of sodium hypophosphite as a curing accelerator (total molar amount of hydroxyl groups in crosslinking agent / carboxyl of polycarboxylic acids) The molar amount of the group = 1.10, the molar amount of the imino group of the cross-linking agent / the molar amount of the carboxyl group of the polycarboxylic acid = 0.37) was obtained, and γ- An aqueous solution prepared by dissolving (2-aminoethyl) aminopropyltrimethoxysilane in water and adjusting the pH to 8.5 with aqueous ammonia was added to an aminosilane cup. After adding and stirring so that the solid component becomes 0.3 part, it is diluted with water so that the solid content becomes 12%, and 4.0 part of an aqueous dispersion of olefin wax having a solid content of 35% is added. Thus, an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 9 was obtained.

(Example 10)
A resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is 100 parts in terms of solid content, and 48 ethanol is used as a crosslinking agent. 0.0 part and 6.0 parts of calcium hypophosphite as a curing accelerator were mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.0, A water-soluble composition having a molar amount of imino group / a molar amount of carboxyl group of polycarboxylic acids = 0.33) was obtained. Furthermore, an aqueous solution prepared by dissolving 2.0 parts of ammonium sulfate as an alkali component neutralizing agent and γ-aminopropyltriethoxysilane as a silane coupling agent in water and adjusting the pH to 8.5 with aqueous ammonia was used. After adding and agitating the ring component to 0.3 part, dilute with water so that the solid content is 15%, and add 4.0 parts of paraffin wax aqueous dispersion with a solid content of 40%. The water-based binder for inorganic fiber heat-absorbing and sound-absorbing materials of Example 10 was obtained.

(Comparative Example 4)
100 parts of a resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is converted into solid content, and triethanolamine is used as a crosslinking agent. 68.1 parts and 6.0 parts of calcium hypophosphite as a curing accelerator were mixed (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acids = 1.0). A water-soluble composition was obtained. Furthermore, as a silane coupling agent, an aqueous solution in which γ-aminopropyltriethoxysilane was dissolved in water and adjusted to pH 8.5 with aqueous ammonia was added so that the aminosilane coupling component was 0.3 part and stirred. Then, it diluted with water so that solid content might be 15%, and obtained the water-based binder for inorganic fiber heat insulation materials of the comparative example 4.

(Comparative Example 5)
A resin solution (solid content 45%) in which polyacrylic acid (acid value 770 mgKOH / g, weight average molecular weight 8,000) is dissolved in water as a polycarboxylic acid is 100 parts in terms of solid content, and diethanolamine is 31 as a crosslinking agent. .2 parts and 4.0 parts of sodium hypophosphite as a curing accelerator (total molar amount of imino group and hydroxyl group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acids = 0.65, crosslinking) A water-soluble composition having a molar amount of imino group of the agent / a molar amount of carboxyl group of the polycarboxylic acid = 0.22) was obtained. Furthermore, as a silane coupling agent, an aqueous solution in which γ-aminopropyltriethoxysilane was dissolved in water and adjusted to pH 8.5 with aqueous ammonia was added so that the aminosilane coupling component was 0.3 parts and stirred. After that, it was diluted with water so that the solid content was 15%, and 4.0 parts of paraffin wax aqueous dispersion having a solid content of 40% was added to obtain an aqueous binder for an inorganic fiber heat insulating sound absorbing material of Comparative Example 5. It was.

(Comparative Example 6)
As a polycarboxylic acid, a resin solution (solid content 40%) in which a polycarboxylic acid (acid value 890 mgKOH / g, weight average molecular weight 14,000) composed of styrene and maleic acid is dissolved in water is 100 in terms of solid content. And 88.8 parts of diethanolamine as a crosslinking agent (total molar amount of hydroxyl group and imino group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.6, molar amount of imino group of crosslinking agent) / Mole amount of carboxyl group of polycarboxylic acids = 0.53) was obtained. Further, an aqueous solution prepared by dissolving γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent in water and adjusting the pH to 8.5 with aqueous ammonia becomes 0.4 parts of aminosilane coupling component. After adding and stirring as described above, the mixture was diluted with water so that the solid content was 15%, and 4.0 parts of a 40% solid content paraffin wax aqueous dispersion was added. An aqueous binder for the material was obtained.

(Comparative Example 7)
As a polycarboxylic acid, a resin solution (solid content 50%) in which an acrylic resin (acid value 720 mgKOH / g, weight average molecular weight 4,000) made of acrylic acid and methyl acrylate is dissolved in water is 100 in terms of solid content. 13.5 parts of diethanolamine as a crosslinking agent, 31.5 parts of glycerol, and 4.0 parts of sodium hypophosphite as a curing accelerator (total molar amount of imino group and hydroxyl group of the crosslinking agent) The molar amount of carboxyl groups of polycarboxylic acids = 1.0, the molar amount of imino groups of the crosslinking agent / the molar amount of carboxyl groups of the polycarboxylic acids = 0.07) was obtained. Further, as the silane coupling agent, an aqueous solution prepared by dissolving γ-aminopropyltriethoxysilane in water and adjusting the pH to 8.5 with aqueous ammonia as the silane coupling agent is 0.4 parts by aminosilane coupling component. The mixture was stirred and diluted with water so that the solid content was 18%, and 4.0 parts of paraffin wax aqueous dispersion having a solid content of 40% was further added. An aqueous binder for an inorganic fiber heat-absorbing sound absorbing material was obtained.

(Comparative Example 8)
As a polycarboxylic acid, a resin solution (solid content 50%) in which a polycarboxylic acid (acid value 420 mgKOH / g, weight average molecular weight 8,000) composed of acrylic acid, methyl acrylate and ethyl acrylate is dissolved in water is used as a solid content. 100 parts in terms of conversion, 26.2 parts of diethanolamine as a crosslinking agent, and 6.0 parts of calcium hypophosphite as a curing accelerator (total molar amount of imino group and hydroxyl group of crosslinking agent / carboxyl of polycarboxylic acids) A water-soluble composition in which the molar amount of the group = 1.0, the molar amount of the imino group of the crosslinking agent / the molar amount of the carboxyl group of the polycarboxylic acid = 0.33) was obtained. Further, as the silane coupling agent, an aqueous solution prepared by dissolving γ-aminopropyltriethoxysilane in water and adjusting the pH to 8.5 with aqueous ammonia as the silane coupling agent is 0.4 parts by aminosilane coupling component. And then diluted with water so that the solid content becomes 18%. Further, an olefin wax with a solid content of 40%: heavy oil with a viscosity grade of 320 mm ² / s = 1: 1 part of the aqueous dispersion 5.0 was added to obtain an aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Comparative Example 8.

(Comparative Example 9)
As a polycarboxylic acid, a resin solution (solid content 35%) in which a polycarboxylic acid (acid value 940 mgKOH / g, weight average molecular weight 16,000) composed of styrene and maleic acid is dissolved in water is 100 in terms of solid content. Part and 58.6 parts of diethanolamine as a crosslinking agent (total molar amount of hydroxyl group and imino group of crosslinking agent / molar amount of carboxyl group of polycarboxylic acid = 1.0, molar amount of imino group of crosslinking agent) / Mole amount of carboxyl group of polycarboxylic acids = 0.33) was obtained. Further, an aqueous solution prepared by dissolving γ- (2-aminoethyl) aminopropyltrimethoxysilane as a silane coupling agent in water and adjusting the pH to 8.5 with aqueous ammonia becomes 0.4 parts of aminosilane coupling component. After adding and stirring as described above, the mixture was diluted with water so that the solid content was 12%, and 2.0 parts of an aqueous olefin wax dispersion with a solid content of 30% was added. An aqueous binder for the material was obtained.

(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 water-based binder for inorganic fiber heat-insulation sound-absorbing materials 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 heat insulation sound-absorbing materials of Examples 4-10 and Comparative Examples 4-10, the restorability, the formaldehyde discharge | release amount, and the tear load were evaluated by the following method. The results are summarized in Table 1.

[Evaluation of resilience 1]
After applying the water-based binder for thermal insulation material for inorganic fibers of Examples 4 to 10 and Comparative Examples 4 to 10 to a predetermined adhesion amount on glass fibers fiberized by the centrifugal method, each is sucked with a suction device. While being deposited on a perforated conveyor, an intermediate of an inorganic fiber heat-absorbing sound-absorbing material was formed. The intermediate is heated in a hot air oven at 220 ° C. for 3 minutes to cure the binder, and an inorganic fiber heat-insulating sound absorbing material (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 40 ° C. and 95% humidity. 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 water-based binder for thermal insulation material for inorganic fibers of Examples 4 to 10 and Comparative Examples 4 to 10 to a predetermined adhesion amount on glass fibers fiberized by the centrifugal method, each is sucked with a suction device. While being deposited on a perforated conveyor, an intermediate of an inorganic fiber heat-absorbing sound-absorbing material was formed. The intermediate is heated in a hot air of 220 ° C. for 5 minutes to cure the binder, and an inorganic fiber adiabatic sound absorbing material 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 between the chucks of a universal testing machine in the thickness direction, and the tear load was measured at a speed of 1 m / min.

  These results are summarized in Table 1.

  In the inorganic fiber heat-insulating and sound-absorbing materials of Comparative Examples 4 to 6, those cured at 260 ° C. are close to the practical range, but at 220 ° C., the thickness sag is noticeable and the binder is not sufficiently cured. Can be estimated. Further, the tear load was lower than that of the phenolic binder (Comparative Example 10) currently in practical use.

  Moreover, when the inorganic fiber heat-absorbing and sound-absorbing material of Comparative Example 7 was cured at 260 ° C., the swelling of the thickness over time was observed at a binder curing temperature of 220 ° C. Insufficient curing is estimated. Further, the tear load was lower than that of the phenolic binder (Comparative Example 10) currently in practical use.

  Moreover, although the same result is observed also in the comparative example 8, even if hardening progresses here, it is estimated that the crosslinking degree of a binder is insufficient. Further, the tear load was lower than that of the phenolic binder (Comparative Example 10) currently in practical use.

  Further, in Comparative Example 9, the restored thickness is rapidly decreased regardless of the curing temperature. This can be presumed that since the number of carboxyl groups in the polycarboxylic acids is large (acid value is high), the degree of crosslinking of the binder becomes too dense and, on the contrary, it becomes brittle.

  On the other hand, the inorganic fiber heat-absorbing and sound-absorbing materials of Examples 4 to 10 have high tear loads, and even when the curing temperature of the binder is lowered, no performance difference is observed in the resilience evaluation, and the curability of the binder is excellent. In particular, the inorganic fiber heat insulating sound absorbing materials of Examples 4 and 10 obtained using polycarboxylic acids having a weight average molecular weight of 2,000 to 15,000 and dialkanolamine are those having high tear strength. there were.

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

4 is a chart showing the curing behavior of the aqueous binder for an inorganic fiber heat-absorbing sound absorbing material of Example 1 and Comparative Example 1. It is a graph which shows the hardening behavior of the aqueous | water-based binder for inorganic fiber heat insulation materials of Example 2 and Comparative Example 2. FIG. It is a graph which shows the hardening behavior of the aqueous | water-based binder for inorganic fiber heat insulation materials of Example 3 and Comparative Example 3.

Claims (8)

Polycarboxylic acids having an acid value of 500 to 900 mg KOH / g obtained by polymerizing an ethylenically unsaturated monomer;
A crosslinking agent containing an alcohol having an amino group and / or an imino group,
The total number of moles of the hydroxyl group, amino group and imino group in the crosslinking agent is 0.8 to 1.5 in terms of mole ratio relative to the number of moles of the carboxyl group in the polycarboxylic acid.
Inorganic, wherein the total number of moles of amino groups and imino groups in the cross-linking agent is 0.2 to 0.8 in terms of mole ratio relative to the number of moles of carboxyl groups in the polycarboxylic acids. Aqueous binder for fiber insulation   The aqueous binder for an inorganic fiber heat-absorbing sound absorbing material according to claim 1, wherein the polycarboxylic acids have 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 inorganic fiber heat-insulating sound absorbing material according to any one of claims 1 to 3, wherein the curing accelerator is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the polycarboxylic acids and the crosslinking agent. Water-based binder.   The aqueous inorganic fiber heat-absorbing material according to any one of claims 1 to 4, comprising 0.1 to 5 parts by mass of ammonium sulfate with respect to 100 parts by mass in total of the polycarboxylic acids and the crosslinking agent. binder.   One aqueous dispersion selected from waxes, or a mixture of waxes and heavy oils, in a solid content conversion of 0.1 parts by weight relative to a total of 100 parts by mass of the polycarboxylic acids and the crosslinking agent. The water-based binder for an inorganic fiber heat-absorbing sound absorbing material according to any one of claims 1 to 5, which is contained in an amount of 1 to 5 parts by mass.   The inorganic fiber heat insulation sound absorption as described in any one of Claims 1-6 which contains 0.1-2 mass parts of silane coupling agents with respect to a total of 100 mass parts of the said polycarboxylic acids and the said crosslinking agent. Water-based binder for materials.   An inorganic fiber heat-absorbing sound-absorbing material, wherein the water-based binder according to any one of claims 1 to 7 is applied to inorganic fibers and cured by heating.