JPS6328086B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is to produce a novel copolymer aqueous dispersion with excellent filler dispersibility and excellent adhesion to hydrophobic fibers such as polypropylene, nylon, and polyester, as well as to substrates such as metals, glass, and plastics. Regarding the method. Recently, the primary base fabric for tufted carpets has been shifting to polypropylene split yarn fabrics due to the shortage of conventional jute fabrics, and polypropylene split yarn fabrics are also being used for artificial turf due to its water resistance. There are many. However, since this polypropylene fabric has almost no water absorption, when a water-dispersed adhesive is used, the adhesive strength with the pile or with the secondary base fabric (backing) tends to be insufficient. On the other hand, in carpet manufacturing, in order to reduce production costs, a large amount of filler, which is cheaper than resin, is often blended as an adhesive component. There is a need for an adhesive that does not reduce adhesive strength when mixed with other adhesives. As a result of intensive research into the development of a water-dispersible adhesive that exhibits excellent filler dispersibility and excellent adhesion to polypropylene fabrics, the present inventors discovered that, in the coexistence of a specific polymer, a specific vinyl monomer It was discovered that an aqueous copolymer dispersion obtained by emulsion polymerization of a copolymer is not only extremely useful as a base resin for adhesives, but also useful for other uses, and in completing the present invention. I've reached it. That is, according to the present invention, (A) a conjugated diolefin having 4 to 6 carbon atoms, an acrylic acid alkyl ester derived from an alkanol having 1 to 18 carbon atoms, and an alkanol having 4 to 18 carbon atoms; 25-99% by weight of one or more monomers selected from the group consisting of methacrylic acid alkyl esters, (B) ethylenically unsaturated aromatic monomer, number of carbon atoms 1-3
0-74% by weight of one or more monomers selected from methacrylic acid alkyl esters derived from alkanols and acrylonitrile, and (C) 1-10% by weight of one or more monomers of ethylenically unsaturated carboxylic acids.
% by weight, when (D) 50 to 90 moles of a sulfo group-containing vinyl monomer and/or 5 to 200 moles of maleic acid or its anhydride are copolymerized per 100 moles of acrylic acid. A water-soluble copolymer consisting of a salt of a polymer having an average molecular weight of 500 to 20,000 obtained by A method for producing an aqueous copolymer dispersion is provided, which comprises at least emulsion polymerization. The conjugated diolefins having 4 to 6 carbon atoms used as the first component (A) in the aqueous copolymer dispersion obtained by the method of the present invention include butadiene-1,3,
2-Methylbutadiene-1,3,2-chlorobutadiene-1,3,2,3-dimethylbutadiene-
However, considering copolymerizability with other monomers and economic efficiency, butadiene-1,3
It is preferable to use Acrylic acid alkyl esters derived from alkanols having 1 to 18 carbon atoms and methacrylic acid alkyl esters derived from alkanols having 4 to 18 carbon atoms, which are also used as the first component (A), can be prepared by ordinary emulsion polymerization. If it is used for
Any of them may be used, such as methyl acrylate, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl or octadecyl acrylate, or butyl methacrylate, pentyl, hexyl, heptyl, Octyl or octadecyl are preferably used. These monomers are used alone or in combination of two or more to internally plasticize the copolymer, but if the proportion is less than 25% by weight, the internal plasticizing ability will be low and the film forming temperature will be low. It becomes high and a homogeneous film cannot be formed. In order to obtain a further sufficient effect, the content is preferably 30% by weight or more. 1st
The upper limit of component (A) is 1% by weight of the required amount of third component (C).
In relation to the above, it is 99% by weight. Examples of the ethylenically unsaturated aromatic monomer of the second component (B) include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, 2,4-dibromustyrene, etc., and have 1 to 3 carbon atoms. Examples of methacrylic acid alkyl esters derived from alkanols include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate. These monomers and acrylonitrile may be used for the purpose of imparting hardness to the copolymer film, but if their proportion is more than 74% by weight, the film will be too hard and the temperature at which the film is formed from the aqueous dispersion will be raised. However, it is not possible to form a homogeneous coating film. One or more of these second component monomers (B) are used in an amount of 0 to 74% by weight. Examples of the ethylenically unsaturated carboxylic acid of the third component (C) include acrylic acid, methacrylic acid, crotonic acid,
Examples include maleic acid and its anhydride, fumaric acid, itaconic acid, and unsaturated dicarboxylic acid monoalkyl esters such as monomethyl maleate, monoethyl fumarate, mono-n-butyl itaconate, and the like. These monomers (C) are necessary components to improve the mechanical stability, freeze stability, and filler dispersibility of the aqueous copolymer dispersion, as well as to improve the adhesion of the film to the substrate. If the proportion is less than 1% by weight, there will be no effect, and if it exceeds 10% by weight, the water resistance of the film will decrease. Therefore, the monomer of the third component
One or more of (C) is used in an amount of 1 to 10% by weight. When producing the copolymer aqueous dispersion, unless otherwise specified, in addition to the above monomers (A), (B) and (C),
One or more types of other copolymerizable monomers (B') can be used. Examples of such a monomer (B') include vinyl esters such as vinyl acetate and vinyl propionate, vinylidene halides such as vinylidene chloride and vinylidene bromide, 2-hydroxyethyl acrylate, and 2-hydroxyethyl acrylate. ―
Hydroxyalkyl esters of ethylenically unsaturated carboxylic acids such as hydroxypropyl, 2-hydroxyethyl methacrylate, etc., glycidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl acrylate, glycidyl methacrylate, etc., and acrylamide, methacrylamide, Examples include N-methylol-acrylamide, N-butoxymethylacrylamide, diacetone acrylamide, and the like. In producing an aqueous copolymer dispersion according to the method of the present invention, one of the features of the present invention is to use a specific water-soluble copolymer (D). This water-soluble copolymer (D) is obtained by copolymerizing 5 to 90 moles of a sulfo group-containing vinyl monomer and/or 5 to 200 moles of maleic acid or its anhydride per 100 moles of acrylic acid, and has an average molecular weight of 500 to 500. 20000 preferably 1000
It is a salt of ~10,000 polymers. Examples of the sulfo group-containing vinyl monomer include allylsulfonic acid, methallylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid,
The sulfo group of these sulfo group-containing polymerizable monomers, which include methacrylate ethyl sulfonic acid, vinyl sulfonic acid, etc., may be converted into a salt form in advance. The sulfo group-containing vinyl monomer is used in an amount of 5 to 90 moles per 100 moles of acrylic acid. Maleic acid or its anhydride is acrylic acid 100%
5 to 200 mol per mole, preferably 10 to 100 mol are used. The polymerization method for the water-soluble copolymer (D) may be any possible polymerization method such as solution polymerization, bulk polymerization, emulsion polymerization, etc. As the salt for the water-soluble copolymer (D), alkali metal salts or ammonium salts such as sodium salts and potassium salts are preferable, but some salts of alkaline earth metals may also be used. You can leave the sum part. If the coexistence ratio of the water-soluble copolymer (D) during emulsion polymerization is less than 0.1 part by weight per 100 parts by weight of the mixture of monomers (A), (B) and (C), the dispersibility of the filler will be affected. and no effect was observed in improving adhesion, and 10
If the amount exceeds 1 part by weight, the copolymerizability of the mixture of monomers (A), (B) and (C) will be significantly inhibited and the polymerization rate will decrease.
An emulsified dispersion liquid in a stable particle state cannot be obtained, and the water resistance of the film also decreases. The preferred range of the amount of water-soluble copolymer used is a mixture of monomers (A), (B) and (C).
The amount is 0.3 to 7 parts by weight per 100 parts by weight. The aqueous copolymer dispersion of the present invention is prepared by an emulsion polymerization method. For example, monomers (A), (B) and
The mixture (C) may be emulsified and dispersed in water using an emulsifier, and emulsion polymerization may be carried out at 0 to 100°C using a free radical generating catalyst in the coexistence of the water-soluble copolymer (D). In addition, in the synthesis of the aqueous copolymer dispersion, additives commonly used in emulsion polymerization can be used as necessary, such as chain transfer agents, polymerization stabilization, and buffering effects. Examples include electrolytes such as ethylenediaminetetraacetic acid, phosphates, sulfates, etc., antioxidants for the purpose of preventing deterioration of copolymers, ultraviolet absorbers, and the like. The aqueous copolymer dispersion obtained by emulsion polymerization with the above composition until the polymerization rate reaches 98% or more is prepared by adding a PH adjuster to improve mechanical stability and freeze stability. is preferably adjusted to between 7 and 10. The aqueous copolymer dispersion after emulsion polymerization is preferably stripped or concentrated to remove unreacted monomers and adjust the solid content to 40 to 55%. The aqueous copolymer dispersion thus obtained by the method of the present invention has excellent filler dispersibility and excellent adhesion to substrates such as hydrophobic fibers, metals, glass, and plastics. ,
Not only is it suitable as a base resin for adhesives, but it can also be used as a fiber treatment agent and a base resin for paints. Surprisingly, the aqueous copolymer dispersion obtained by the method of the present invention exhibits less skinning phenomenon during storage, and even more surprisingly, the aqueous copolymer dispersion obtained by the method of the present invention If a carpet is manufactured using a blended adhesive, blister may occur (when the adhesive dries, boiling occurs inside the adhesive, and some of the adhesive blows out onto the back side of the carpet, significantly damaging the appearance). phenomenon) can be prevented from occurring. Due to its excellent adhesion to hydrophobic fibers, when the aqueous copolymer dispersion obtained by the method of the present invention is used as a binder for nonwoven fabrics and spunbond fabrics made of fibers with low water absorption such as nylon and polyester, it can be used as a binder for conventional anionic fibers. Alternatively, it exhibits extremely superior adhesive strength compared to an aqueous copolymer dispersion obtained by emulsion polymerization using a nonionic emulsifier. Next, the present invention will be explained in more detail with reference to Examples. Note that "parts" and "%" in each example are based on weight. Examples 1 to 6 and Comparative Examples 1 to 3 50 parts of butadiene, 47 parts of styrene, 3 parts of acrylic acid
Part, "Sodium salt of polymer obtained by polymerizing acrylic acid and methallylsulfonic acid or maleic acid" Amounts listed in Table 1 below, 0.7 part of sodium alkylbenzenesulfonate, 0.1 part of ammonium ethylenediaminetetraacetate, tertiary dodecyl mercaptan 0.3 parts of potassium persulfate, 0.3 parts of potassium persulfate, and 120 parts of ion-exchanged water were placed in a nitrogen-substituted autoclave equipped with a stirrer, and polymerization was carried out at 60°C for 12 hours. Next, the pH was adjusted to 8.5 with solid alkali, and unreacted was removed by stripping. Monomers were removed and concentrated to obtain an aqueous copolymer dispersion with a solid content of 54%. Next, using the copolymer aqueous dispersion, a second
Adjust the adhesive compound for carpet packing by making the formulation shown in the table, and apply it to the carpet consisting of acrylic loops and primary polypropylene base fabric at a weight of 1400 g per 1 m ² , and use chute as the secondary base fabric. They were pasted together and dried in a hot air dryer at 140°C for 10 minutes to create a carpet. Next, cut this carpet into 5cm wide pieces,
A peel test of the secondary base fabric and a thread removal test of the acrylic loop thread were conducted. In addition, the back surface of the carpet was observed and blisters were determined. The test results are shown in Table 1. From Table 1, it can be seen that all the aqueous copolymer dispersions of the examples of the present invention showed good results.

【table】

[Table] * Examples 7 to 13 and Comparative Examples 4 to 6 manufactured by San Nopco Co., Ltd. 100 parts of the monomer mixture listed in Table 3, average molecular weight
0.5 parts of sodium salt of 3000 acrylic acid (1 mol)/methallylsulfonic acid (0.25 mol) copolymer;
0.7 parts of sodium alkylbenzenesulfonate, 0.1 part of ammonium ethylenediaminetetraacetate, 0.3 parts of tertiary dodecyl mercaptan, 0.3 parts of potassium persulfate, and 120 parts of ion-exchanged water were placed in a nitrogen-substituted autoclave equipped with a stirrer, and polymerized at 60°C for 12 hours. Next, the pH was adjusted to 8.5 with caustic soda, and unreacted monomers were removed and concentrated by stripping to obtain an aqueous copolymer dispersion with a solid content of 54%. Next, an adhesive compound and a carpet were prepared in the same manner as in Example 1, and the same performance tests as in Example 1 were conducted. Table 3 shows the test results. As shown in Table 3, all of the aqueous copolymer dispersions of the examples of the present invention showed good results.

[Table] Examples 14 to 19 and Comparative Examples 7 to 10 Ion-exchanged water was added to a stainless steel reaction pot with a stirrer.
120 parts and 1.5 parts of alkylbenzenesulfonic acid sodium salt, each having an average molecular weight of 3000.
Prepare the amount listed in Table 4 of the sodium salt of acrylic acid (1 mol)/methylylsulfonic acid (0.5 mol) copolymer or the sodium salt of acrylic acid (1 mol)/maleic acid (0.5 mol) copolymer. , 55
℃, 100 parts of the monomer mixture listed in Table 4, 0.5 part of concentrated potassium sulfate, and 0.5 part of bisulfite sodium formalin condensate were continuously added dropwise over 3 hours, and
The reaction was continued for hours to obtain an aqueous copolymer dispersion with a solid content of 45%. The pH of the obtained aqueous copolymer dispersion was adjusted to 7 with aqueous ammonia. Next, a polyester nonwoven fabric with a fiber weight of 30 g/m ² was impregnated with these copolymer aqueous dispersions,
After squeezing with a mangle, dry at 140℃ for 5 minutes,
A nonwoven fabric with a resin solid content/fiber weight ratio of 25/75 was created. Next, the obtained nonwoven fabric was subjected to a washing test and a dry cleaning test. The test results are shown in Table 4. As shown in Table 4, the examples of the present invention showed good results.

【table】

Claims (1)

[Claims] 1 (A) Conjugated diolefin having 4 to 6 carbon atoms, acrylic acid alkyl ester derived from alkanol having 1 to 18 carbon atoms, and 4 to 18 carbon atoms
(B) an ethylenically unsaturated aromatic monomer, an alkanol having 1 to 3 carbon atoms; One or more monomers selected from methacrylic acid alkyl esters and acrylonitrile derived from
When emulsion polymerizing a monomer mixture consisting of 74% by weight and (C) 1 to 10% by weight of one or more monomers of ethylenically unsaturated carboxylic acid, (D) acrylic acid
5 to 90 sulfo group-containing vinyl monomers per 100 moles
mol and/or average molecular weight obtained by copolymerizing 5 to 200 mol of maleic acid or its anhydride
A water-soluble copolymer consisting of a salt of 500 to 20,000 polymers is allowed to coexist in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of a mixture of monomers (A), (B), and (C), and emulsion polymerization is carried out. A method for producing an aqueous copolymer dispersion, characterized by: