JPS63333A - Composition for preparaing foamed article - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a foam-forming composition obtained by a special polymerization method. The present invention relates to a modified foam-forming composition that can be used to form a foam.

[Prior art and its problems] Conventionally, natural and synthetic resin aqueous dispersions have been treated with foaming agents, coagulants,
It is known to form a foam by adding a cross-linking agent and other additives, mechanically foaming the foam, applying it to Omurakami, or pouring it into a mold, drying, coagulating, and curing. Such natural and synthetic resin aqueous dispersions include natural rubber latex, styrene-butadiene copolymer aqueous dispersions, and acrylic acid ester copolymer aqueous dispersions. The formed foams are used in a variety of applications due to their structural advantages such as light weight, wall thickness, texture, and feel.

However, many of these foams are inferior in performance such as mechanical strength and durability, and in order to be used in a wider range of applications, improvements such as higher strength and higher durability are required. For example, natural rubber and butadiene copolymers improve light resistance, heat resistance, and mechanical strength, while acrylic ester copolymers improve mechanical strength, solvent resistance, cold resistance, and elasticity. is necessary.

On the other hand, various methods have been proposed for forming foams from polyurethane aqueous dispersions and the like, and these foams are attracting attention as having high performance that has improved the above-mentioned drawbacks.

However, the conventional mechanical foaming methods for polyurethane aqueous dispersions are not satisfactory in terms of foam moldability, and the inherent properties of the resin have not been exploited for a wide range of applications, and improvements are needed. 0 For example, it is unsatisfactory in terms of stable and wide foaming moldability that can freely form foams with a high expansion ratio and a high coating thickness, and improvements are needed.

In this way, when forming a foam from a synthetic resin aqueous dispersion,
Although there is a strong demand for foams to combine excellent physical properties such as high strength and durability with foam moldability that allows them to be freely molded into stable and industrially useful forms, it has not been possible to achieve this. Important and difficult technical matters in such conventional techniques are concentrated in foam moldability, strength of the resin film, and the balance between the two. That is, when foaming an aqueous dispersion, bubbles are generated and maintained finely and uniformly, and the bubbles are coalesced from the aqueous dispersion, which is essentially a weak aqueous dispersion, to form partition walls containing bubbles. The objective is to form a resin film strong enough to withstand permanent bubble retention without causing disappearance.

To this end, various improvements have been made, for example, by blending a styrene-butadiene system with a urethane dispersion. For example, JP-A-59-52883 discloses incorporating random type nonionic activators of ethylene oxide and propylene oxide into a blend. Furthermore, Japanese Patent Application Laid-Open No. 81-16498 discloses that it is effective to add a phosphate to the blend. Japanese Patent Publication No. 1981-1
Japanese Patent No. 8797 discloses that an alkyl mercaptan is added during polymerization, and the resulting butadiene-based aqueous dispersion is blended with an aqueous urethane dispersion. The above method is judged to be superior to the conventional technique in terms of foam moldability and dispersion stability, and it is also judged that the strength of the resin film has been improved to some extent.

However, the above-mentioned improvement methods may not be sufficient to be applied to a wide variety of applications. That is, foam moldability and dispersion stability are insufficient under some conditions. For example, foam moldability is not sufficient at low temperatures, dispersion stability is not sufficient at high temperatures, and the reinforcing effect of the resin film is not necessarily sufficient.

The present invention aims to further improve the foam moldability and dispersion stability under such severe conditions, and further improve the resin film strength, that is, the foam strength, beyond the limits of improvement by mere blending or additive auxiliaries. The object of the present invention is to provide an improved foam molding composition that can be applied to a wide variety of applications with increasingly sophisticated and diversified required properties.

[Means for Solving the Problems] The present inventors have developed foam properties that are significantly improved in terms of strength, durability, etc., and foam moldability that allows the foam to be freely molded into forms that are stable and industrially useful even at low temperatures. As a result of intensive research on the moldability of foams from aqueous dispersions of synthetic resins, we found that self-dispersing polyamides are polymers obtained by (co)polymerizing unsaturated monomers in an aqueous medium in the presence of -. The inventors have discovered that the use of an aqueous dispersion can impart excellent foam properties and foam moldability, and have arrived at the present invention.

That is, the present invention provides a method for forming a foam characterized by comprising an aqueous polymer dispersion obtained by polymerizing a conjugated diene and/or an ethylenically unsaturated monomer in an aqueous medium containing a self-dispersed polymer. to provide a composition for use.

As self-dispersing polymers, polyurethane, polyester and epoxy resins are preferably used alone or in mixtures. As the conjugated diene and/or ethylenically unsaturated monomer, butadiene and a mixture of ethylenically unsaturated monomers copolymerizable with butadiene are preferred.

The conjugated dienes used in the present invention include phtadiene-1,3,2-methyl-butadiene-1.3,2-
Examples include chlorbutadiene-1, 3, etc., but if copolymerizability with other monomers and economic efficiency are taken into account, butadiene-1.
It is preferable to use 1 and 3.

Examples of the ethylenically unsaturated monomer used in the present invention include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate,
Propyl methacrylate, butyl acrylate, butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, hebutyl acrylate, heptyl methacrylate, octyl acrylate, octyl methacrylate, octadecyl acrylate, methacrylate Acrylic acid alkyl esters and methacrylic acid alkyl esters such as octadecyl acid; ethylenically unsaturated aromatic monomers such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene, 2,4-dibromustyrene, etc. unsaturated nitriles such as acrylonitrile and methacrylonitrile; acrylic acid, methacrylic acid, crotonic acid, maleic acid and its anhydrides, fumaric acid, itaconic acid, and unsaturated dicarboxylic acid monoalkyl esters, such as monomethyl maleate, fumaric acid Ethylenically unsaturated carboxylic acids such as monoethyl acid and mono-n-butyl itaconate; vinyl esters such as vinyl acetate and vinyl propionate; vinylidene halides such as vinylidene chloride and vinylidene bromide; 2-hydroxyethyl acrylate; Hydroxy alkyl esters of ethylenically unsaturated hepcarboxylic acids such as 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, etc.; glycidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl acrylate, glycidyl methacrylate, etc.; Examples of radically polymerizable monomers include rheamide, methacrylamide, N-methylol-J-reacrylamide, N-methylolmethacrylamide, N-butoxymethylacrylamide, and diacetone acrylamide.

Next, polyurethane, polyester and epoxy resins suitable as self-dispersing polymers for use in the present invention will be described.

The self-dispersing polyurethane used in the present invention is
A polyurethane resin made by chain-elongating a polyurethane prepolymer consisting of a polyol such as a polyester polyol or polyether polyol and an aromatic, aliphatic, or alicyclic diisocyanate with a low molecular weight compound having two or more active hydrogens such as a diol or diamine. The following methods are known as methods for zero dispersion or dissolution, which refers to stable dispersion or dissolution in water.

(1) A method in which ionic groups such as hydroxyl groups, amino groups, and carboxyl groups are introduced into the side chains or terminals of polyurethane to impart wood-philic properties, and the polyurethane is dispersed or dissolved in water by self-emulsification.

(2) A method in which a water-soluble polyol such as polyethylene glycol is used as a polyol as the main raw material of polyurethane to form a wood-philic polyurethane and to disperse or dissolve it in water.

The water-dispersed polyurethane used in the present invention is not limited to a single dispersion or dissolution method as described above, but a mixture obtained by each method can also be used. Examples of these water-soluble or water-dispersible polyurethanes include the "Noidran" series (manufactured by Dainippon Ink & Chemicals Co., Ltd.) as a commercially available product.

The self-dispersing polyester in the present invention is (1) one prepared by copolycondensation of a dicarboxylic acid having an alkali metal sulfonic acid salt in an aromatic nucleus, and (2) one prepared by adding a polycarboxylic acid anhydride to a polyester and neutralized with a base. , (3) copolycondensation of polyethylene glycol, and combinations thereof. Examples of dicarboxylic acids having an alkali metal sulfonic acid salt in the aromatic nucleus used in the self-dispersing polyester include alkali metal salts such as sulfoterephthalic acid, 5-sulfoisophthalic acid, and 4-sulfonaphthalene-2,7-dicarboxylic acid. It will be done. Also included are ester-forming derivatives used in the production of ordinary polyesters, such as lower alcohol esters such as methyl esters and ethyl esters of these carboxylic acids. Among these, the most preferred alkali metal salts of 5-sulfoinphthalic acid and sulfoterephthalic acid are sodium salts and potassium salts.These sulfonic acid alkali metal salt-containing compounds are essential components for making polyester resins water-soluble. Naturally, this content affects the dispersibility and solubility of the polyester resin in water.The self-dispersing polyester of the present invention includes those that are transparently dissolved in water and those that are dispersed in an emulsion state. This is adjusted, for example, by the content of the alkali metal sulfonic acid salt-containing compound. This is 15 mol% of the total carboxylic acid component.
If the amount is higher, the water resistance of the resulting resin will decrease significantly,
If it is less than 3 mol%, hydrophilicity may be insufficient and a stable water-dispersed polyester resin may not be obtained. The preferred amount used is 5 to 10 mol% of the total carboxylic acid component.

Other aromatic carboxylic acids include terephthalic acid, isophthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, trimellitic anhydride,
Examples include pyromellitic anhydride, and ester-forming derivatives thereof are also included. It is desirable to use such an aromatic carboxylic acid in an amount of 50 mol% or more of the total carboxylic acid component, including the above-mentioned dicarboxylic acid having an alkali metal sulfonic acid salt in the aromatic nucleus.If it is less than 50 mol%, the mechanical properties of the resulting resin will be affected. In addition to decreasing the adhesiveness, the adhesiveness may increase. The amount of aromatic carboxylic acid used is preferably 70 mol%
The above content is particularly preferably 70 to 97 mol%.

Carboxylic acids other than aromatic carboxylic acids include succinic acid,
Examples include aliphatic and alicyclic carboxylic acids such as maleic acid, fumaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, timer acid, and cyclohexanedicarboxylic acid, and ester-forming derivatives of these acids. included.

These carboxylic acids are used within the remaining range of all carboxylic acids other than aromatic carboxylic acids. The polyol component is not particularly limited, and all polyols commonly used in polyester resins can be used, such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,8-hexane. Diol, 1.4-
Cyclohexane dimetatool, 1,4-bis(hydroxyethoxy)benzene, hydrogenated bisphenol A, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, glycerin, trimethylolpropane, trimethylolethane,
Examples include pentaerythritol.

When dispersing polyester in water, if the content of alkali metal sulfonate is relatively large, the temperature is 40°C to 10°C.
It can be self-dispersed and made aqueous by simply stirring in warm water at 0°C. However, if the alkali sulfonic acid total salt content is relatively low and it is difficult to make it aqueous, use a small amount of organic solvent, such as lower alcohols or glycol. It can also be made aqueous with the help of esters, cellosolves, cyclic ethers, ketones, etc. These water-soluble or water-dispersible polyesters include, for example, the commercially available “Finetex-
Examples include the ESJ series (manufactured by Dainippon Ink & Chemicals).

The self-dispersing epoxy resin in the present invention is an epoxy resin obtained by modifying the epoxy resin with another compound and introducing a segment with emulsifying power into the molecule to impart self-dispersing properties.

For example, JP-A-53-1228 discloses a grafted epoxy resin obtained by polymerizing a monomer mixture containing a carboxylic acid monomer using a free radical generator such as benzoyl peroxide in the presence of an epoxy resin. It has been shown that resins can be stably dispersed in aqueous media containing bases. - As an example, there is a polymer represented by the structural formula (1) described below, and a commercially available product is Dick Fine GM-280 (manufactured by Dainippon Ink & Chemicals).

In addition, JP-A-58-43382 discloses a composition in which an epoxy resin and a carboxyl-functional polymer are reacted in the presence of a specific tertiary amine.

In addition, JP-A-55-3481 and JP-A-55-3482 disclose that a carboxyl group-functional polymer is esterified with an epoxy resin in the presence of an amine esterification catalyst, and a self-dispersing epoxy resin that can be self-dispersed in water with a base is produced. Ester copolymers are disclosed.

The ratio of the self-dispersed polymer (A) to the conjugated diene and/or ethylenically unsaturated monomer (B) used in the present invention is not particularly limited, but the solid content weight ratio (
A)/(B) = 5/95 to 3515 is preferred.

The aqueous polymer dispersion in the present invention is prepared by a conventional emulsion polymerization method under reaction conditions of pH 3 to 5, θ to 100°C x 5 to 15 hours. The substance (mixture) is dispersed in water, preferably without emulsifiers, and a free radical generating catalyst 1 such as K
P S (lhS203), A P S ((NH4
)2s20g), the resulting polymer water dispersion can be emulsion polymerized preferably at 40°C to 70°C using an aqueous catalyst such as hydrogen peroxide, or an oily catalyst such as t-butyl hydroperoxide or cumene hydroperoxide. The liquid has a pH of 5
~8, with a viscosity of about 30 to 1000 cP, preferably pH 8 to 8 with an alkaline solution to improve stability.
Adjusted to 9.

Furthermore, in the present invention, additives commonly used in emulsion polymerization, such as chain transfer agents, ethylenediaminetetraacetic acid for the purpose of polymerization stabilization and buffering effects, etc. may be used as necessary.

The aqueous polymer dispersion obtained by the above method is concentrated to the required solids content, for example by a method such as stripping.

Foams obtained using compositions made by adding other additives based on the aqueous polymer dispersion thus obtained have mechanical strength, heat resistance, cold resistance, light resistance, and It can exhibit excellent physical properties such as solvent properties and elasticity that cannot be obtained with conventional methods.

Other additives include foaming aids, viscosity modifiers, crosslinking agents, and the like.

Foaming aids include sodium laurate, coconut oil soap, sodium myristate, ammonium stearate, sodium palmitate, sodium oleate,
Used are sodium higher alcohol sulfate, sodium higher fatty acid amide alkyl sulfonate, saponin, gelatin, or casein. Carbon number 1-20
Fluorosurfactants having a perfluoroalkyl group or a fluoroalkyl group are also used.

Viscosity modifiers include casein, alginate, gum arabic, bentonite, clay, carboxylated methylcellulose, and polyvinyl alcohol.

Polyvinylpyrrolidone copolymers, polyethylene oxide polymers, polyacrylic acid emulsions, etc. are used. The amount of these added is usually 0.1 to 5 parts, preferably 0.5 to 3 parts. The viscosity of synthetic resin emulsion is 1
000 to 15000 cP is suitable.

As the crosslinking agent, water-soluble melamine-formaldehyde resin, water-soluble urea-formaldehyde resin, water-soluble or water-dispersible epoxy resin, aziridine compound, polyisocyanate resin, etc. are used.

In order to fully reflect the elastic properties of a foam like polyurethane resin, it is effective to add silicone oil. For example, dimethyl silicone oil,
Examples include methylphenyl silicone oil, amino-modified silicone oil, and polyether-modified silicone oil. The amount added is 0.1 to 3 parts by weight per 100 parts by weight of the emulsion. Pre-emulsified silicone oil may also be used.

In addition, colorants, fillers, anti-aging agents, anti-mold agents, etc. may be used within the range that does not impair the purpose of the present invention.

The composition thus adjusted to an appropriate viscosity is then foamed in a rubber latex by a known method to convert it into a composition having uniform, fine cells. In this case, mechanical foaming is most common, but the type of foaming machine is not particularly limited, and those generally used for foaming rubber latex can be used. - Examples are as follows. Contains a random copolymer, adjusted to an appropriate viscosity, and optionally foaming aids,
The composition containing a viscosity modifier, a foam stabilizer, a crosslinking agent, etc. is fed into a foaming machine by a gear pump, etc. 6 On the other hand,
Gas (usually air) is pumped into the foaming machine by a compressor or the like.

Each flow rate is coated by a gauge.The emulsion and gas fed into the foaming machine are mixed there.The gas fed is finely divided and dispersed into one composition by a rotating cylinder, and the foamed composition is thus mixed. Things come out of the foam machine. The amount of gas mixed in (the ratio of gas to the composition), which is related to the density of the composition foam obtained by drying, is controlled by controlling the amount of gas injected, and the size of the bubbles is determined by controlled by the viscosity of the cylinder and the rotational speed of the cylinder. (Note that a hand mixer is experimentally sufficient for foaming the composition.) In this case, the foaming ratio is generally 1.5 to 6.

The foamed composition is poured into a mold or cast onto a substrate and dried. In this case, a doctor knife is generally used to coat Omurakami to a uniform thickness. The base materials include m's fabrics, fiber knitted fabrics, textile products such as raised fabrics, flocked fabrics, and nonwoven fabrics, paper, polyvinyl chloride sheets, leather sheets, release paper, and type II films such as polypropylene and polyester. , a glass plate, a metal plate, etc., respectively.

When the applied composition containing bubbles is dried, the dispersion medium (water) is removed, and a foam material having uniform and fine bubbles is obtained. The drying temperature is 80-180°C, preferably 100-140°C. When the emulsion is cured by heat treatment, the drying is followed by heat treatment.

[Effects of the Invention] When the composition for forming a foam according to the present invention is used, the foam formed is stable even at low temperatures, so it is easy to form various types of foam under all conditions, and the resulting foam has a low density. In other words, it has sufficient strength even at high expansion ratios and can be used for various purposes. For example, synthetic leather for bags, clothing, shoes, and other uses, artificial leather, and other fake leather-like coated fabrics,
Carpets (backings), kotatsu mats, entrance/bath mats, sponge sheets or other molded products, how to use them not only to form foam, but also to serve as an adhesive layer while forming foam, and to form foam. 1. For example, a foam layer is formed between the base material (I) and the base material (II) and the base materials are fixed together at the same time, or the upper part of one base material. These include those in which a foam is formed and the base material and another dense base material are fixed at the same time, and foam flocking in which the foam also serves as a binder for the pile. In addition, the formed foam is embossed to give a secondary uneven pattern.

This is an example of another characteristic of the foam of the present invention, which is good adhesion of the cell walls under constant heat/pressure, and the remaining characteristics are high expansion ratio and high ionicity.

The above examples of applications and uses are not limiting, but are merely examples that take advantage of the wide range of industrially advantageous foam-forming features of the present invention.

Next, the present invention will be specifically explained with reference to Examples. Note that the numbers of parts and percentages shown in each sentence are parts by weight and percentages by weight unless otherwise specified.

Example 1 In a nitrogen-substituted autoclave, 200 parts of ion-exchanged water, 50 parts of butadiene, 40 parts of styrene, 10 parts of acrylonitrile, and 100 parts of Hytran AP-20 (water-dispersed polyurethane, manufactured by Dainippon Ink & Chemicals Co., Ltd.) were charged. At a polymerization temperature of 55°C, 0.1 part of potassium persulfate was added to initiate polymerization. The polymerization rate was 38.3% 6 hours after the start of polymerization.
The mixture was cooled to obtain an aqueous polymer dispersion (A).

Add an aqueous solution of carboxymethyl cellulose to a viscosity of 80
00 cP, then 1 part of silicone oil, 3 parts of glycerol triglycidyl ether, and 4 parts of ammonium stearate were added and mixed uniformly.

This mixture was foamed using a continuous Fi mechanical foaming machine (manufactured by Suga Kikai), applied onto cotton broadcloth, and heat-treated at 120° C. for 8 minutes to obtain a foamed sheet with uniform fine bubbles and a smooth surface. This foamed sheet was found to be excellent in abrasion resistance, light resistance, etc.

Example 2 100 parts of the water-dispersed polyurethane used in Example 1 was replaced with Finetex ES-8751, which is a water-dispersed polyester.
Polymerization was carried out in the same manner as in Example 1 except that 00 parts (manufactured by Dainippon Ink & Chemicals) was used to obtain a polymer aqueous dispersion (B).
I got it. Table 1 shows the physical properties of a composition obtained by blending this product in the same manner as in Example 1.

Example 3 100 parts of the water-dispersible polyurethane used in Example 1 was mixed with Dick Fine GN-280, a water-dispersible epoxy resin.
Polymerization was carried out in the same manner as in Example 1, except that 100 parts (manufactured by Dainippon Ink and Chemicals) was used, and polymer aqueous dispersion (C
) was obtained. Table 1 shows the physical properties of a composition obtained by blending this product in the same manner as in Example 1.

Comparative Example 1 Ion-exchanged water 1 was placed in a nitrogen-substituted autoclave with a stirrer.
10 parts, Luxstar DS-801 (manufactured by Dainippon Ink & Chemicals Co., Ltd.) as a solid content of 1.0 parts, sodium diphenyl ether sulfonate and Eucol 271A (manufactured by Nippon Nyukazai Oil) 1.0 parts, tertiary dodecyl mercaptan 0. 5 parts, ammonium ethylenediaminetetraacetate 0.1
100 parts of the monomer composition (50 parts of butadiene)
40 parts of styrene, 10 parts of acrylonitrile) was added with 0.5 part of potassium persulfate, and emulsion polymerization was carried out at 60° C. with stirring until the polymerization rate was 89.0%. Next, 1.0 part of sodium hexametaphosphate was added to the aqueous polymer dispersion after polymerization.
A solution of 0.5 part of sodium tripolyphosphate dissolved in 10% potassium hydroxide solution was added, and unreacted monomers were removed by steam distillation.Cicondensation was performed to obtain a solid content of 55.0%, a viscosity of 100 cP, and a pH of 8.9. An acrylonitrile-styrene-butadiene copolymer aqueous dispersion (11) was obtained. Table 1 shows the physical properties of the Mi product obtained by blending the obtained copolymer in the same manner as in Example 1.

Comparative Example 2 60 parts of butadiene, 30 parts of acrylonitrile, 10671 parts of methacrylic acid, 3 parts of sodium alkylbenzenesulfonate
Department (Neoperex F-25, Kako Atlas product),
Ethylene oxide and propylene oxide 90:1
0.5 part of polyalkylene gelicol ether having polymer buttons randomly copolymerized at a molar ratio of 0 (Targitol XD, manufactured by Union Carbide), 0.5 part of sodium pyrophosphate, 0.1 part of ammonium ethylenediaminetetraacetate , tertiary dodecyl mercaptan 0.3
parts, potassium persulfate 0.3 parts and ion exchange water 120 parts
1 part into a nitrogen-substituted autoclave with a stirrer, and
Polymerization was carried out at 0°C for 15 hours, and unreacted monomers were removed and concentrated by stripping to obtain an aqueous acrylonitrile-butadiene copolymer dispersion (solid content 55%, viscosity 3θOcP, pH 5.7). E) was obtained. Table 1 shows the physical properties of a composition obtained by blending the obtained copolymer in the same manner as in Example 1.

Table 1 ■ In the table, (a) is for 2.5 times foaming liquid (1+u+ coating), (b) is for 7 times foaming liquid (5 mm coating)■ "Foaming liquid condition" is when 500cc of mechanically foaming liquid is used. The state of the bubbles when it was placed in a beaker and the state of the bubbles when it was allowed to stand for 5 minutes and then the upper layer thickness of about 1 cm+* was scraped off were observed and compared.

■: Bubbles are fine and uniform, with no change.

O: The bubbles were fine and uniform, but slightly coarsened.

Δ: Bubbles were slightly non-uniform and quite coarse.

×: Contains many coarse bubbles and is extremely heterogeneous.

■ The "state of the foam" was investigated by observing the state of the cells in the cross section of the foam and the smoothness of the surface.

■ = Fine and uniform air bubbles with a smooth surface.

O: There are coarse bubbles and the surface smoothness is slightly inferior.

Δ: Bubble is rough and there are some cracks.

X: There are cracks.

■ "Abrasion strength" was measured using a Gakushin type abrasion tester (number of times until failure under a flat method load of 500 g).

■: Good for 1000 times or more Q: 999 times to 20
0 times Δ: 193 times to 50 times ×: 48 times or less■ "
Regarding "light resistance", the degree of discoloration and abrasion strength after 20 hours of irradiation with a fade meter were examined.

Degree of discoloration @: No discoloration O: Slight yellowing Δ: Yellowing ×: Significant discoloration (yellowing)

Claims (3)

[Claims] (1) For forming a foam characterized by comprising an aqueous polymer dispersion obtained by polymerizing a conjugated diene and/or an ethylenically unsaturated monomer in an aqueous medium containing a self-dispersed polymer. Composition. (2) The composition for forming a foam according to claim 1, wherein the self-dispersing polymer is an aqueous polymer containing at least one selected from polyurethane, polyester, and epoxy resin. (3) The composition for forming a foam according to claim 1, wherein the conjugated diene and/or the ethylenically unsaturated monomer is a mixture of butadiene and an ethylenically unsaturated monomer copolymerizable with butadiene. .