JPH1112946A - Water-based resin composition for nonwoven fabric, nonwoven fabric and asphalt roofing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonwoven fabric excellent in heat-resistant shape stability, mechanical strength and elongation, and suitable as an asphalt roofing sheet. SOLUTION: This water-based resin composition comprises (A) a water-based polyurethane resin 300-5,000 eq./10<6> g in urethane group concentration, 0.2-1.5 dl/g in reduced viscosity, containing >=50 eq./10<6> g of sulfonic acid metal salt group and/or carboxyl group and >=0 deg.C in glass transition temperature, (B) at least one kind selected from the group consisting of polyvinyl alcohol, starch and water-soluble modified cellulose, and, if needed, (C) a curing agent reactive with the component A and/or component B, and (D) a neutralizing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin composition for a nonwoven fabric comprising a polyurethane resin as an active ingredient, and more particularly to a nonwoven fabric provided with the resin composition and having excellent heat resistance, strength, elongation and water resistance. And a nonwoven fabric obtained by roofing a sheet of asphalt on the nonwoven fabric.

[0002]

2. Description of the Related Art Conventionally, as a base fabric for an asphalt roofing sheet, a heat-bonded non-woven fabric, a needle-punched non-woven fabric or the like has been used as it is or after being impregnated with a resin. However, when the nonwoven fabric is used as an asphalt roofing sheet, the heat-resistant morphology is insufficient, and when asphalt impregnation at a high temperature, when the nonwoven fabric is stretched by the processing tension and commercialized with distortion remaining, the waterproof sheet is formed. When heated by sunlight after construction, it shrinks, and the asphalt waterproof sheet cannot exhibit the intended waterproof performance, which is a problem.
In order to solve such problems, polyvinyl alcohol-based fibers having good heat stability are mixed and used, and a method of processing a base fabric is devised. For example, a blended base fabric of a polyester fiber and a polyvinyl alcohol fiber is impregnated with a resin containing polyvinyl alcohol or starch as a main component. After heat-fixing, then needle punching from the other side,
Japanese Patent Application Laid-Open No. 08-246358 discloses a two-layer nonwoven fabric made of glass fiber, polyvinyl alcohol-based fiber, and polyester fiber.

[0003]

However, polyvinyl alcohol-based fibers and glass fibers are expensive, and complicated fiber processing as described above is costly. The use of needle-punched non-woven fabrics has been demanded, but the use of these non-woven fabrics cannot be used because the form stability and other properties are significantly reduced. In order to supplement the performance of the nonwoven fabric, it has been considered to impregnate and use a resin.However, a general acrylic emulsion that is crosslinked with an amino resin is
In applications requiring heat resistance during processing and after construction, such as asphalt roofing sheets, if an inexpensive polyester nonwoven fabric is used for the base fabric, no heat resistant form stability can be obtained. Similarly, when using the above-described povar or starch resin having a high softening point, there is a problem that basic characteristics such as heat-resistant morphological stability, strength and elongation are insufficient and practical characteristics cannot be obtained.

[0004]

In view of such circumstances, the present inventors have conducted intensive studies to obtain a water-based resin for nonwoven fabric having excellent heat-resistant form stability, strength, and elongation. The aqueous resin composition containing, as a main component, one or more of an aqueous polyurethane resin comprising a polyester diol, an organic diisocyanate compound and, if necessary, a chain extender having a molecular weight of less than 500, and at least one of polyvinyl alcohol, starch, and water-soluble modified cellulose is a polyester. The present inventors have found that even when a nonwoven fabric is used as a base fabric, good heat-resistant morphological stability and other properties can be obtained, and have reached the present invention. That is, according to the present invention, the urethane group concentration obtained by reacting a polyester diol (a) having a number average molecular weight of 500 or more, an organic diisocyanate compound (b), and a chain extender (c) having a molecular weight of less than 500 at a ratio shown in Formula 1 is adjusted. 300-5,000
Equivalent weight / 10 ⁶ g and reduced viscosity of 0.2 to 1.5 dl
/ G, and a polyurethane resin (A) containing 50 equivalents / 10 ⁶ g or more of a sulfonic acid metal base and / or a carboxyl group and having a glass transition temperature of 0 ° C. or more, and polyvinyl alcohol, starch, and water-soluble modified cellulose. Or 1
A water-based resin composition containing at least one kind of (B), a curing agent (C) which can react with (A) and / or (B) if necessary, and a neutralizing agent (D), and (A) , (B),
(C) and (D) are aqueous resin compositions for nonwoven fabrics having the ratios shown in Formulas 2 to 4, and nonwoven fabrics and asphalt roofing sheets using the same. Formula 1: 0.8 <(b) / ((a) + (c)) ≦ 1 (equivalent ratio) Formula 2: (A) / (B) = 20/80 to 80/20 (solid weight ratio) Formula 3: ((A) + (B)) / (C) = 100/0 to 70/30 (solid weight ratio) Formula 4: (D) / (acid value of A) = 0.1 to 20 (equivalent ratio) )

The nonwoven fabric to which the aqueous resin composition for a nonwoven fabric of the present invention has been applied is excellent in heat-resistant form stability (hereinafter simply referred to as "heat-resistant") to not only a polyvinyl alcohol-based fabric but also a polyester-based fabric and a short-fiber fabric. It is excellent in morphology), strength, and elongation, and a nonwoven fabric suitable for an asphalt roofing sheet can be obtained.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The number average molecular weight used in the present invention is 50.
In the polyester diol (a) of 0 or more, preferably 1,000 to 3,000, the acid component is selected from the total acid components.
The content of the aromatic dicarboxylic acid is preferably at least 60 mol%, more preferably at least 80 mol%. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-p, p'-dicarboxylic acid, diphenyl-m, m '
-Dicarboxylic acid, diphenylmethane-p, p'-dicarboxylic acid, 2,2'-bis (4-carboxyphenyl) propane, indene dicarboxylic acid and the like, and one or more of these may be used in combination. preferable. These aromatic dicarboxylic acids can be arbitrarily selected from physical properties and economy, but it is preferable to use terephthalic acid and isophthalic acid alone or in combination from the viewpoint of mechanical properties and water dispersibility, and more preferably. Is that terephthalic acid is in the range of 40 to 100 mol% of the total acid component. In addition, 3 such as trimellitic anhydride
A carboxylic acid having a functionality of at least one may be used in an amount of 10 mol% or less.

[0007] If necessary, the acid component 4
Succinic acid, glutaric acid, adipic acid, azelaic acid, in an amount of less than 0 mol%, more preferably less than 20 mol%,
An aliphatic dicarboxylic acid such as sebacic acid, dodecanedioic acid and dimer acid, or an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, tetrahydrophthalic acid and hexahydroisophthalic acid can be used. Care must be taken because the presence of the aliphatic dicarboxylic acid or the alicyclic dicarboxylic acid lowers the heat resistance and the storage stability of the aqueous dispersion. It is preferable to use cyclohexanedicarboxylic acid or sebacic acid in less than 20 mol% of the acid component in consideration of the physical properties of the coating film and the storage stability.

Further, when it is desired to introduce a carboxyl group into the polyester diol, an acid anhydride such as phthalic anhydride or trimellitic anhydride is added to the polyester diol after the polymerization to give 18%.
The mixture is added at 0 to 220 ° C. under normal pressure to modify the end with carboxy or copolymerize maleic acid or fumaric acid containing an unsaturated double bond at a concentration of 10 mol% or less.
It becomes possible by graft-modifying acrylic acid or the like with (meth) acrylic acid ester or the like.

The polyester diol (a) of the present invention is a hard polyester diol whose acid component is mainly composed of an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic acid, and a soft polyester diol mainly composed of an aliphatic dicarboxylic acid. May be blended and used.

The glycol components used in the polyester diol (a) used in the present invention include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 3-methyl-1,
5-pentanediol, 2-ethyl-2-butylpropanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, dimethylol heptane, dimethylol pentane, diethylene glycol, triethylene glycol, cyclohexane dimethanol , TCD glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide and / or propylene oxide adduct of bisphenol A, ethylene oxide and / or propylene oxide adduct of bisphenol F, ethylene oxide or propylene oxide addition of bisphenol S Things and the like. Among them, it is particularly preferable that the ethylene oxide and / or propylene oxide adduct of bisphenol A represented by the general formula (a) is contained in an amount of 20 to 100 mol% based on the total polyol.

[0011]

Embedded image (Wherein R ₁ and R ₂ are hydrogen or a methyl group;
m and n are each 1 or more, and at the same time, 2 ≦ m + n
≦ 6. )

The polyol is particularly excellent in heat resistance when immersion-processed in asphalt, and can obtain excellent properties in both strength and elongation of the nonwoven fabric. As other glycols, ethylene glycol, neopentyl glycol, hexanediol, pentanediol, and 3-methyl-1,5-pentanediol are preferable in terms of physical properties, storage stability of the aqueous dispersion, and cost. In addition, glycerin, trimethylolpropane, pentaerythritol, etc.
A polyol having a functionality of not less than 10 mol% may be used.

The polyurethane resin (A) obtained after the reaction of the polyester diol (a) with the organic diisocyanate compound used in the present invention is used as an aqueous solution or aqueous dispersion. In order to dissolve or disperse the polyurethane resin in water, it is necessary that the polyurethane resin contains 50 equivalents / 10 ⁶ g or more, preferably 100 to 800 equivalents of the metal sulfonic acid group and / or carboxyl group. When these functional groups are less than 50 equivalents / 10 ⁶ g, not only does the solubility or dispersibility of the polyurethane resin in water decrease, but also the compatibility with polyvinyl alcohol, starch, and water-soluble modified cellulose blended in the present invention, Miscibility decreases.

As a method for introducing a metal sulfonate group into a polyurethane resin, a dicarboxylic acid or polyol containing a metal sulfonate group is copolymerized in the above-mentioned polyester diol, or a diol containing a metal sulfonate group is used as a chain extender. There is a way to do that. Of these, a method of copolymerizing a polyester diol with a metal sulfonic acid base is preferred from the viewpoint of solubility during synthesis.

Examples of the dicarboxylic acid or polyol containing a sulfonic acid metal base include sulfoterephthalic acid, 5-
Sulfoisophthalic acid, 4-sulfonaphthalene-2,7-
Metal salts such as dicarboxylic acid and 5 [4-sulfophenoxy] isophthalic acid, or 2-sulfo-1,4-butanedioxide
And metal salts such as 2,5-dimethyl-3-sulfo-2,5-hexanediol. Examples of the metal salt include salts of Li, Na, K, Mg, Ca, Cu, Fe and the like. Among them, particularly preferred is 5-sodium sulfoisophthalic acid.

Examples of the method for introducing a carboxyl group into the polyurethane resin include the above-mentioned method of adding a carboxylic acid anhydride to the polyester diol and the method of using a carboxyl group-containing chain extender. A method using a chain extender is preferred.

When producing a polyurethane resin, the chain extender (c) having a molecular weight of less than 500, which is used if necessary, is a compound having two or more functional groups having high reactivity with isocyanate groups. Preferably, these functional groups are two, but three or more compounds may be used in combination. These chain extenders have the effect of increasing the urethane group concentration in the polyurethane resin and imparting toughness specific to the polyurethane resin.

Specific examples of the chain extender include ethylene glycol, propylene glycol, tetramethylene glycol, 1,6-hexanediol, cyclohexanedimethanol, diethylene glycol, neopentyl glycol, and 3-methyl-1,5-pentanediol. Glycols, monoethanolamine, amino alcohols such as N-methylethanolamine, hexamethylenediamine, isophoronediamine, 4,4-diaminodiphenylmethane, diamines such as diaminodiphenylether, and the like. Include dimethylolpropionic acid, dimethylolbutanoic acid, tartaric acid and the like.

Of these, neopentyl glycol and 1,6-hexanediol are preferred, and dimethylolpropionic acid and dimethylolbutanoic acid are preferred for imparting an acid value.

The organic diisocyanate compound (b) used for producing the polyurethane resin (A) of the present invention includes tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate and the like. Aromatic diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 4,4 '
-Aliphatic and alicyclic diisocyanates such as diisocyanate cyclohexylmethane, hydrogenated diphenylmethane diisocyanate and hydrogenated xylylene diisocyanate. Of these, tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate are particularly preferable from the viewpoint of heat resistance.

The polyurethane resin (A) of the present invention contains the above-mentioned polyester diol (a), organic isocyanate compound (b) and, if necessary, a chain extender (c) having a molecular weight of less than 500 at a ratio represented by the following formula (1). It is obtained by reacting.
If (b) / ((a) + (c)) is less than 0.8, the molecular weight of the polyurethane resin is too low and heat resistant morphology, strength and elongation cannot be obtained. If it exceeds 1, excess isocyanate remains. Adversely affects storage stability. After dissolving the polyurethane resin (A) of the present invention in an organic solvent, the organic isocyanate compound (b) is charged at a ratio shown in Formula 1 to 60 to 9
A method in which the polyester diol (a) is reacted with an equivalent excess of the isocyanate compound (b) at 60 to 90 ° C. before the chain extender (c).
Is synthesized at a ratio shown in the formula 1, and further reacted to complete the polymerization.

When a carboxyl group is used for imparting water solubility or water dispersibility, it must be neutralized with a neutralizing agent. In order to obtain good solubility and dispersibility in water,
A carboxyl group concentration of 500 equivalents / 10 ⁶ g or more is required, but a carboxyl group concentration of 100 to 250 equivalents / 1 is required.
0 as ⁶ g, is preferably used in combination with metal sulfonate described above.

Further, as the component of the polyester resin (A) other than the above, there may be mentioned a dicarboxylic acid or a polyol containing a metal base of a known acidic phosphorus compound.

As the neutralizing agent (D), ammonia water, methylethanolamine, diethylethanolamine, N
-Methyl-diethanolamine, bis-hydroxypropyl-methylamine, tri-n-butylamine, triethylamine, bis-2-hydroxypropylamine, N
-Methyl-ethanolamine, aminomethylpropanol, 3-amino-1-propanolamine, isopropanolamine, 2-amino-2-hydroxymethyl 1-
Amines such as 3-propanediol, aminomethyl-propanediol, cyclohexylamine and t-butylamine; salts of weak acids and strong bases such as sodium carbonate and potassium carbonate; and hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide. Things and the like. If these neutralizing agents remain in the coating film after drying and curing, they adversely affect the physical properties of the coating film. Therefore, low-boiling amines such as aqueous ammonia and dimethylethanolamine that volatilize and do not remain after drying and curing are preferable. When a neutralizing agent is used, the ratio of the acid value of the neutralizing agent (D) to the acid value of the polyurethane resin (A) is 0.1 to 20 (equivalent ratio) as shown in Formula 4,
Preferably it is 1-2 (equivalent ratio). This ratio is 0.
If it is less than 1 (equivalent ratio), the carboxyl group cannot be charged and desorbed, and good water dispersibility cannot be obtained. On the other hand, if it exceeds 20 (equivalent ratio), it will remain in the coating film after drying to lower the water resistance, or adverse effects such as hydrolysis of the polyurethane resin during storage of the aqueous dispersion.

The polyester resin of the present invention can be dissolved or dispersed in water by a known method. That is,
Generally, a method of polymerizing polyurethane in a hydrophilic low-boiling solvent such as a methyl ethyl ketone / isopropyl alcohol system and then substituting water with water is used.

Although it is desirable for the work or environment to contain as little co-solvent as possible, the polyurethane resin may be used for the purpose of increasing the affinity for water and assisting the dispersibility in water. The co-solvent is an organic compound having a solubility of 20 g or more in 1 liter of water at 20 ° C. Specific examples thereof include aliphatic and alicyclic alcohols, ethers, esters and ketone compounds. For example, monohydric alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol and tert-butanol, glycols such as ethylene glycol and propylene glycol, methyl cellosolve, and ethyl cellosolve ,
ethylene glycol alkyl ethers such as n-butyl cellosolve and acetates thereof, ethyl carbitol, diethylene glycol alkyl ethers such as n-butyl carbitol and acetates thereof, propylene glycol alkyl ethers and acetates thereof, dioxane, tetrahydrofuran and the like Ethers, esters such as ethyl acetate, and ketones such as methyl ethyl ketone, cyclohexanone, cyclooctanone, cyclodecanone, and isophorone. Particularly preferred are n-butyl cellosolve, n-butyl carbitol,
And propylene glycol monoethyl ether.

The polyurethane resin (A) used in the present invention has a glass transition temperature of 0 ° C. or more, preferably 30 to 110.
° C. When the temperature is lower than 0 ° C., the heat resistance morphology becomes poor.
If the temperature exceeds 110 ° C., the material becomes too hard, and the elongation of the nonwoven fabric is reduced.

The reduced viscosity of the polyurethane resin (A) used in the present invention is 0.2 dl / g or more, preferably 0.3 dl / g.
/ G or more. If it is less than 0.2 dl / g, good heat resistant morphology, strength and elongation of the nonwoven fabric cannot be obtained. The number average molecular weight is preferably 3,000 or more, more preferably 8,000 to 25,000.

In the present invention, the polyurethane resin is used alone,
Alternatively, if necessary, two or more kinds can be used in combination.

The nonwoven fabric water-soluble resin composition of the present invention contains a polyurethane resin (A) and any one or more of polyvinyl alcohol, starch, and water-soluble modified cellulose (B). (A) / (B) = 20/8
0-80 / 20, preferably 40 / 60-60 / 40
(Solid weight ratio). In the formula 1, if (A) is less than 20 solid weight, it becomes too brittle,
The strength and elongation of the nonwoven fabric are reduced, and when it exceeds 80 solid weight, the heat resistant formability is reduced.

The polyvinyl alcohol includes partially saponified and completely saponified ones. From the viewpoint of heat resistance, a completely saponified one having a saponification degree of 95% or more is preferred. Although the molecular weight is not specified, those having a polymerization degree of 100 to 1,000 are preferable. If the degree of polymerization is too high, the viscosity of the solution increases, which is not preferable. Further, a carboxyl-modified product may be used. Starch includes those made from potato, corn, wheat, rice and the like. It is preferable to use an acid or amylase to form a soluble starch in order to improve solubility. Examples of the water-soluble modified cellulose include hydroxyethyl cellulose, methyl cellulose, methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, sodium carboxymethyl cellulose, cellulose nitrate carboxymethyl ether, and the like. Among them, it is particularly preferable to use polyvinyl alcohol having a polymerization degree of 10 to 1000 alone or in combination with soluble starch or water-soluble modified cellulose from the viewpoint of solubility and viscosity.

The aqueous resin composition for a nonwoven fabric of the present invention can be used as it is, but from the viewpoint of physical properties such as heat resistance and water resistance, a curing agent (C) which can react with (A) and / or (B). Is more preferably blended in the ratio shown in the second formula. The cross-linking agent must be a water-soluble or water-dispersible, and includes, for example, an amino resin, an epoxy compound and an isocyanate compound. In the second formula, a preferable compounding ratio is ((A) + (B)) / (C) = 5/95.
２０20/80 (solid weight ratio). (C) ratio is 3
If it exceeds 0 solid weight ratio, the heat-resistant morphology will decrease.

Examples of the amino resin include formaldehyde adducts such as urea, melamine and benzoguanamine.
Further, there may be mentioned alkyl ether compounds of alcohols having 1 to 6 carbon atoms. Specifically, methoxylated methylol urea, methoxylated methylol-
N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine and the like are preferable, and methoxylated methylol melamine is preferable.

As the epoxy compound, bisphenol A
Diglycidyl ethers and oligomers thereof, diglycidyl ethers of hydrogenated bisphenol A and oligomers thereof, diglycidyl orthophthalate, diglycidyl isophthalate, diglycidyl terephthalate, diglycidyl p-oxybenzoate, tetrahydrophthalate Acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol di Glycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, Triglycidyl citrate, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether And glycerol alkylene oxide adduct triglycidyl ether.

Further, as the isocyanate compound, there are aromatic and aliphatic diisocyanates and polyisocyanates having more than two valencies, and either low molecular weight compounds or high molecular weight compounds may be used. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds Amounts and, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine,
Dimethylolpropionic acid, low molecular weight active hydrogen compounds such as dimethylolbutanoic acid or various polyester polyols, polyether polyols, terminal isocyanate group-containing compounds obtained by reacting with a high molecular weight active hydrogen compound such as polyamides and the like. Can be

For use in an aqueous system, the isocyanate compound is preferably a blocked isocyanate. As the isocyanate blocking agent, for example, phenol,
Phenols such as thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, acetoxime, methylethylketoxime, cyclohexanone oxime and its oximes, alcohols such as methanol, ethanol, propanol, butanol, Halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol;
tertiary alcohols such as t-butanol and t-pentanol, ε-caprolactam, δ-valerolactam,
lactams such as γ-butyrolactam and β-propyl lactam; and active methylene compounds such as aromatic amines, imides, acetylacetone, acetoacetate, and malonic acid ethyl ester, mercaptans, imines, and urea. And diaryl compounds such as sodium bisulfite. The blocked isocyanate can be obtained by subjecting the above isocyanate compound to an isocyanate blocking agent to undergo an addition reaction by a conventionally known appropriate method. These need to be dissolved or dispersed in water,
The emulsion is forcibly emulsified in the presence of an emulsifier, or is usually used after being modified with a polyether polyol, a carboxyl group-containing diol, or the like.

A curing accelerator can be used in combination with these crosslinking agents. For amino resins, organic acids such as paratoluenesulfonic acid and dodecylbenzenesulfonic acid, and amine blocks thereof can be used.For isocyanate compounds, tin compounds and zinc acetate can be used. For compounds, amine compounds, imidazoles and the like can be used.

The aqueous resin composition for a nonwoven fabric of the present invention is used by impregnating a base fabric. As the base cloth, polyester base cloth such as polyethylene terephthalate or polybutylene terephthalate of long fiber or short fiber, polyvinyl alcohol (vinylon) base cloth, polyolefin base cloth such as polyethylene or polypropylene, nylon 6, nylon 66
And the like, and can be used alone or in combination, but the present invention does not limit the type of the base fabric. Of these, polyethylene terephthalate and polyvinyl alcohol-based fabrics are preferred in terms of cost and heat resistance, and polyethylene terephthalate-based fabrics alone are more preferred in terms of cost. However,
This base fabric has not been put into practical use due to the lack of heat resistance, strength, and elongation of conventional impregnating agents such as acrylic resin, polyvinyl alcohol, and starch, but the aqueous resin composition for a nonwoven fabric of the present invention is not used. By using it, excellent physical properties can be obtained at low cost.

The amount of the aqueous resin for nonwoven fabric impregnated in the base fabric is 10 to 50% by weight, preferably 20 to 40% by weight. If the impregnation amount is less than 10% by weight or more than 50% by weight, the heat resistance formability, strength and elongation are undesirably reduced.

[0040]

The present invention will be specifically described below with reference to examples. In the examples, “part (s)” means “part (s) by weight”. Each measurement item followed the following method.

(1) Reduced viscosity ηsp / c (dl / g) 0.10 g of a sufficiently dried polyester resin was mixed with a phenol / tetrachloroethane (6/4 by weight) mixed solvent 25
It dissolved in cc and measured at 30 degreeC.

(2) Molecular weight The number average molecular weight was determined by GPC in terms of polystyrene.

(3) Acid Value A 0.2 g sample was precisely weighed and dissolved in 20 ml of chloroform. Then, it was determined by titration with 0.01 N potassium hydroxide (ethanol solution). Phenolphthalein was used as the indicator.

(4) Glass transition point temperature The glass transition point was measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC). The sample was prepared by placing 5 mg of the sample in an aluminum holding lid type container and crimping it.

(5) Composition Analysis of Polyester Resin The composition was analyzed by NMR (nuclear magnetic resonance method) or the like.

(6) Storage Stability of Aqueous Resin Composition An aqueous solution or an aqueous dispersion was stored at room temperature for one month, and then visually judged. ：: good, △: a small amount of precipitate or gel-like substance is generated, ×: separation, gelling XX: good dispersion is not obtained at the initial stage

(7) Heat resistant formability A non-woven fabric of 120 g / m ² prepared by needle punching 3 denier short fiber polyethylene terephthalate was impregnated with the aqueous resin composition, squeezed with a roll, and dried at about 20% by weight.
After pre-drying at 40 ° C.
It was dried and cured at 50 ° C. for 5 minutes. The obtained resin-impregnated nonwoven fabric was cut into a width of 5 cm, and immersed in a 200 ° C. silicone oil bath with a load of 2 kg for 10 seconds. The deformation ratio before and after the test was calculated by the following equation. The smaller the absolute value of the numerical value, the better. Heat resistant formability = (W−W ₀ ) × 100 / W ₀ (%) W ₀ : initial sample width (5 cm), W: sample width after heat treatment

(8) Breaking strength and elongation The nonwoven fabric prepared in (7) is 5 cm wide and 10 c between chucks.
It was measured with a Tensilon type tensile tester in m. The larger the numerical values of both the breaking strength and the elongation, the better.

(9) Dimensional stability after asphalt impregnation Asphalt was melted and impregnated at 200 ° C. into the nonwoven fabric prepared in (7) to prepare an asphalt roofing sheet. Leave this in a hot air oven at 80 ° C for 250 hours,
The dimensional change before and after standing was measured.

(8) Moisture Resistance The nonwoven fabric prepared in (7) was allowed to stand at 60 ° C. and a relative humidity of 95% for one week, and evaluated by the retention of breaking strength before and after that.

(9) Synthesis Example of Polyester Diol Resin Synthesis of Polyester Diol (a) 4 equipped with a stirrer, thermometer and Vigreux fractionating tube
97 parts of dimethyl terephthalate, 91 parts of dimethyl isophthalate, 9 parts of sodium 3,5-dicarbomethoxybenzenesulfonate, 41 parts of ethylene glycol, 71 parts of neopentyl glycol, and 0.3 part of tetrabutyl titanate as a catalyst 180
A transesterification reaction was carried out for 5 hours while distilling off methanol generated at ~ 230 ° C outside the system. Next, the Vigreux fractionation tube was removed, and the reaction system was set to 5 mm over 30 minutes.
The pressure was reduced to Hg, and the temperature was raised to 210 ° C. during this time. Further, a polycondensation reaction was performed at 0.3 mmHg and 230 ° C. for 10 minutes to obtain a polyester diol (a). As a result of analysis such as NMR, the obtained polyester diol was found to be terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // ethylene glycol / neopentyl glycol =
50/47/3 // 49/51 (molar ratio), pale yellow having a reduced viscosity of 0.15 dl / g, a number average molecular weight of 2,000, an acid value of 10 equivalents / 10 ⁶ g, and a glass transition temperature of 62 ° C. It was a transparent resin. Table 1 shows the results.

Synthesis of Polyester Diols (b) to (e) Polyester diols (b) to (e) were synthesized in the same manner as polyester diol (a). Table 1 shows the results.

Synthesis of Polyurethane Resin (A) In a four-necked flask equipped with a stirrer, a thermometer and a cooler, 273 parts of methyl ethyl ketone was charged, and 100 parts of the polyester diol (a) was dissolved at 70 ° C. Then, 10.8 parts of isophorone diisocyanate was charged and reacted at the boiling point of methyl ethyl ketone for 1 hour. Then, 0.01 parts of dibutyltin dilaurate as a catalyst was added,
The reaction was performed for 3 hours until the remaining isocyanate disappeared. Then, the mixture was cooled to 50 ° C., and 68 parts of isopropyl alcohol was added.
Aqueous polyurethane resin (A) was prepared by charging 261 parts of ion-exchanged water heated to 0 ° C. and gently reducing the pressure to distill off the solvent.
I got The polyurethane resin (A) was a translucent stable emulsion containing no solvent. Table 2 shows the results.

Synthesis of Polyurethane Resins (B) to (C) Polyurethane resins (B) to (C) were synthesized in the same manner as the polyurethane resin (A). Table 2 shows the results.

Synthesis of Polyurethane Resin (D) A four-necked flask equipped with a stirrer, a thermometer and a cooler was charged with 325 parts of methyl ethyl ketone, and 80 parts of polyester diol (d) and 10 parts of neopentyl glycol as a chain extender were added. 3 parts of dimethylolpropionic acid to 70
Dissolved at ° C. Then, 32.2 parts of 4,4'-diphenylmethane diisocyanate was charged and reacted at the boiling point of methyl ethyl ketone for 1 hour. Then, 0.02 part of dibutyltin dilaurate as a catalyst was added, and the reaction was further continued for 3 hours until the remaining isocyanate disappeared. Then, the mixture was cooled to 50 ° C., and 81 parts of isopropyl alcohol and 4.5 parts of triethylamine as a neutralizing agent were dissolved in 60 parts.
325 parts of ion-exchanged water heated to 0 ° C. were charged, and the pressure was gradually reduced to distill off the solvent to obtain an aqueous polyurethane resin (D). Table 2 shows the results.

Synthesis of Polyurethane Resin (E) Polyurethane resin (E) was synthesized in the same manner as polyurethane resin (D). Table 2 shows the results.

Synthesis of Comparative Polyurethane Resins (F) to (G) Comparative Polyurethane (F) to Polyurethane (F)
(G) was synthesized. Table 3 shows the results.

Synthesis of Comparative Acrylic Resin (H) In a four-necked flask equipped with a thermometer and a condenser, 700 parts of ion-exchanged water, 1.5 parts of sodium dodecylbenzenesulfonate as an emulsifier, 80 parts of methyl methacrylate, and butyl acrylate 20 parts were charged and heated to 80 ° C. under a nitrogen atmosphere while stirring. Two solid portions of an aqueous solution of potassium persulfate as a polymerization initiator were added to initiate polymerization. Further, a mixed monomer of 160 parts of methyl methacrylate, 25 parts of butyl acrylate, and 15 parts of hydroxyethyl acrylate, and 4 solid parts of an aqueous potassium persulfate solution were added dropwise over 1 hour, and after the addition was completed, the mixture was reacted for 3 hours to obtain an acrylic emulsion. . The resulting emulsion had no residual monomer odor and was milky white and stable.

Example 1 An aqueous resin composition having a solid content of 15% was prepared by mixing 40 solid parts of an aqueous polyurethane resin dispersion (a), 60 solid parts of a completely saponified polyvinyl alcohol having a degree of polymerization of 300, and ion-exchanged water. Created. This aqueous resin was stable at room temperature. When the properties of the nonwoven fabric were evaluated using this, good physical properties as shown in Table 4 were obtained.

Examples 2 to 5 The characteristics of the nonwoven fabric were evaluated in the same manner as in Example 1. Table 4 shows the results
Shown in

Comparative Examples 1 to 6 The characteristics of the nonwoven fabric were evaluated in the same manner as in Example 1. Table 4 shows the results
Shown in

Comparative Example 7 A comparative acrylic emulsion (H) (100 solid parts) and methylated melamine Sumimar M40W (Sumitomo Chemical Co., Ltd.) (25 solid parts) were mixed and evaluated in the same manner as in Example 1. The morphology was significantly poor at -65%.

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 4]

[0066]

[Table 5]

As is clear from Tables 1 to 5, the aqueous resin composition for a nonwoven fabric of the present invention has excellent stability, and furthermore has good heat-resistant form stability, strength and strength even in an inexpensive polyethylene terephthalate-based nonwoven fabric. An excellent asphalt roofing sheet having excellent elongation and other physical properties can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI E04D 5/02 D06M 15/327 Z

Claims (5)

[Claims] 1. A urethane group concentration obtained by reacting a polyester diol (a) having a number average molecular weight of 500 or more, an organic diisocyanate compound (b) and, if necessary, a chain extender (c) having a molecular weight of less than 500 at a ratio shown in Formula 1. 300 ~
5,000 equivalent / 10 ⁶ g and reduced viscosity of 0.2 to
Polyurethane resin (A) containing 1.5 dl / g and containing a sulfonic acid metal base and / or a carboxyl group in an amount of 50 equivalents / 10 ⁶ g or more and having a glass transition temperature of 0 ° C. or more, and polyvinyl alcohol, starch, and water-soluble modification An aqueous resin composition containing any one or more types of cellulose (B), and a curing agent (C) and a neutralizing agent (D) that can react with (A) and / or (B) if necessary. And an aqueous resin composition for a nonwoven fabric, wherein (A), (B), (C) and (D) have the ratios shown in Formulas 2 to 4. Formula 1: 0.8 <(b) / ((a) + (c)) ≦ 1 (equivalent ratio) Formula 2: (A) / (B) = 20/80 to 80/20 (solid weight ratio) Formula 3: ((A) + (B)) / (C) = 100/0 to 70/30 (solid weight ratio) Formula 4: (D) / (acid value of A) = 0.1 to 20 (equivalent ratio) ) 2. The aqueous resin composition for a nonwoven fabric according to claim 1 is added to a base fabric mainly composed of polyester fibers in a solid content of 1%.
Nonwoven fabric impregnated with 0 to 50% by weight. 3. An asphalt roofing sheet prepared by immersing the nonwoven fabric of claim 2 in molten asphalt. 4. The aqueous resin composition for a non-woven fabric according to claim 1, wherein the polyester diol (a) has an aromatic dicarboxylic acid in an amount of 20 to 100% by mole of the total acid component. 5. A polyester diol (a) comprising, as a glycol component, an ethylene oxide and / or propylene oxide adduct of bisphenol A represented by the following general formula (A):
The aqueous resin composition for a nonwoven fabric according to claim 1, wherein the water-based resin composition is contained in the aqueous resin composition. Embedded image (Wherein R ₁ and R ₂ are hydrogen or a methyl group;
n is a number of 1 or more and 2 ≦ m + n ≦ 6 at the same time.
It is. )