JPH086077B2 - Carpet backing agent - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a carpet backing agent, and more specifically, to a carpet backing agent having excellent feeling and further excellent strength characteristics such as peel strength and yarn removal strength in carpet. Regarding

(Prior Art) A copolymer latex used for a carpet backing agent provides mechanical and chemical stability of the backing agent and pigment dispersion stability, and has a peel strength and a moderate strength for a backed work piece. Gives texture, dimensional stability, etc.

In a recent carpet backing agent, the proportion of the inorganic filler is increasing in order to reduce the cost. for that reason,
The strength characteristics of the backing agent, such as peeling strength and yarn removal strength, are deteriorated, resulting in a hard texture. Conventional copolymer latexes used in these backing agents include butadiene / styrene / ethylenically unsaturated carboxylic acid copolymers. The backing agent using these latexes cannot satisfy both properties of soft feeling and high strength desired as a carpet in a composition containing a large amount of inorganic filler.

Then, in order to solve this problem, there is a method of decreasing the particle size of the copolymerized latex or increasing the proportion of the ethylenically unsaturated carboxylic acid in the copolymer. Further, there is a method in which t-dodecyl mercaptan or the like is added as a chain transfer agent all at once or in divided portions to reduce the gel content of the copolymer.

(Problems to be Solved by the Invention) However, these conventional carpet backing agents have not yet fully met the demands for satisfying both properties of soft feeling and high strength.

An object of the present invention is to solve the problems of conventional carpet backing agents, and to provide a carpet backing agent having further improved strength characteristics such as peeling strength and yarn removal strength in soft feeling.

(Means for Solving the Problem) In order to solve this problem, as a result of various researches on a method for producing a copolymer latex for blending a carpet backing agent, a specific polymerization chain transfer agent was specified at the time of emulsion polymerization. It was found that the carpet backing agent using the copolymerized latex obtained by using it in a ratio has excellent properties in which soft feeling and high strength are well balanced.

That is, the present invention is, as the first invention, (a) an aliphatic conjugated diene, an alkyl acrylate having an alkyl group having 2 to 10 carbon atoms, and 6 carbon atoms.
2 to 70% by weight of at least one monomer selected from alkyl methacrylates having 14 to 14 alkyl groups, (b) 0 to 8% by weight of ethylenically unsaturated carboxylic acid, and (c) above (a) And a monomer mixture consisting of 22 to 98% by weight of another monomer copolymerizable with (b) (total 100 parts by weight).
Emulsion polymerization in an aqueous medium in the presence of 0.05 to 20 parts by weight of a polymerization chain transfer agent consisting of 5 to 100% by weight of α-methylstyrene dimer and 95 to 0% by weight of another polymerization chain transfer agent per 00 parts by weight. The present invention provides a carpet backing agent containing a copolymer latex thus obtained and an inorganic filler as main components.

Furthermore, the present invention provides (a) an aliphatic conjugated diene, an alkyl acrylate ester having an alkyl group having 2 to 10 carbon atoms, and 6 carbon atoms as the second invention.
2 to 70% by weight of at least one monomer selected from alkyl methacrylates having 14 to 14 alkyl groups, (b) 0 to 8% by weight of ethylenically unsaturated carboxylic acid, and (c) above (a) And a monomer mixture consisting of 22 to 98% by weight of another monomer copolymerizable with (b) (total 100 parts by weight).
(B) 5 to 95% by weight of at least one compound selected from (a) terpinolene, α-terpinene, γ-terpinene and dipentene, and (b) alkyl mercaptans, carbon tetrachloride, xanthogen disulfides and thiuram. Weight chain transfer agent consisting of 95 to 5% by weight of at least one compound selected from disulfides
A carpet backing agent comprising a copolymer latex obtained by emulsion polymerization in an aqueous medium in the presence of 0.05 to 20 parts by weight and an inorganic filler as main components.

 Hereinafter, the present invention will be described in detail.

Examples of the aliphatic conjugated diene-based monomer as the component (a) used for producing the copolymer latex of the present invention include 1,3-butadiene, isoprene and 2-chloro-1,3-butadiene. Among these,
1,3-butadiene is preferred.

Examples of the acrylic acid alkyl ester having an alkyl group having 2 to 10 carbon atoms as the component (a) include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like, and having 6 to 14 carbon atoms. Examples of the methacrylic acid alkyl ester having an alkyl group include 2-ethylhexyl methacrylate and lauryl methacrylate.

Of these aliphatic conjugated diene-based monomers, acrylic acid alkyl ester and methacrylic acid alkyl ester monomers can be used alone or in combination of two or more.

These monomers (a) are essential components for imparting appropriate flexibility and adhesive strength to the resulting copolymer,
The ratio is 2 in the polymer constituents of the copolymer latex.
~ 70% by weight. When it is necessary to maintain a specific three-dimensional shape such as a car carpet, the monomer (a) component is preferably 2 to 10% by weight. The monomer (a) component is preferably 20 to 65
% By weight. If the proportion is less than 2% by weight, the copolymer is inferior in flexibility and adhesive strength. On the other hand, if the proportion is more than 70% by weight, the resulting carpet is too soft, and the peeling strength and the yarn removal strength are low, and the blister resistance is further reduced. Also gets worse.

The (b) ethylenically unsaturated carboxylic acid monomer used in the present invention includes, for example, itaconic acid, acrylic acid,
Examples include methacrylic acid, fumaric acid, and maleic acid. These ethylenically unsaturated carboxylic acid monomers are 1
Although it is possible to use one kind alone or two or more kinds in combination,
A suitable combination of acrylic acid and methacrylic acid is preferred. The proportion of the ethylenically unsaturated carboxylic acid monomer (b) used is 0 to 8% by weight in the polymer constituents, preferably 0.1.
5 to 4.5% by weight. If the proportion used exceeds 8% by weight, the viscosity of the latex obtained will be high, making it impractical.

Further, (c) other monomers copolymerizable with each of the above monomers are aromatic vinyl compounds, vinyl cyanide compounds, vinyl acetate, acrylamide, methacrylic acid alkyl esters having 1 to 5 carbon atoms, preferably Examples include methyl methacrylate.

Among these, examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene and chlorostyrene, and styrene is particularly preferable. Furthermore, examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile, and of these, acrylonitrile is preferable. These other monomers (c) may be used alone or in combination of two or more. In particular, as the other monomer,
When copolymerizing using methyl methacrylate,
It is preferable because the polymerization stability can be remarkably improved.

The proportion of these other monomers (c) used is 22 to 98% by weight, preferably 25 to 80% by weight, based on the polymer constituent components.
In the carpet backing composition using the latex in which the use ratio is less than 22% by weight, the texture of the resulting carpet becomes too soft. On the other hand, if the usage rate exceeds 98% by weight, it will be too hard on the contrary, and it will hinder the handling and construction. In addition, the main physical properties of the carpet, namely the yarn removal strength and the peeling strength from the secondary base cloth, will be inferior. It also becomes worse.

The copolymer latex in the present invention is obtained by emulsion-polymerizing the above-mentioned monomer mixture in an aqueous medium, but the feature of the present invention is that this emulsion-polymerization is carried out in the presence of a specific chain transfer agent. is there.

That is, in the first invention of the present invention, in the presence of a polymerization chain transfer agent consisting of 5 to 100% by weight of α-methylstyrene dimer and 0 to 95% by weight of another polymerization chain transfer agent,
Further, in the second invention of the present invention, 5 to 95% by weight of at least one compound selected from (a) terpinolene, α-terpinene, γ-terpinene and dipentene
And (b) an alkylmercaptan, carbon tetrachloride, xanthogen disulfides and at least one compound selected from thiuram disulfides in an amount of 95 to 5% by weight.

The first invention and the second invention will be described in detail below.

The polymerization chain transfer agent (hereinafter referred to as the polymerization chain transfer agent (I)) used in the first invention comprises 5 to 100% by weight of α-methylstyrene dimer and 0 to 95% by weight of another polymerization chain transfer agent.

As the α-methylstyrene dimer, (i) 2-4-diphenyl-4-methyl-1-pentene, (b) 2-4-diphenyl-4-methyl-2-pentene, and (c) There is 1-1-3-trimethyl-3-phenylindane. As the α-methylstyrene dimer, a preferable composition is (a) component 40% by weight or more, (b) component and / or (c) component 60% by weight or less,
More preferably, the component (a) is 50% by weight or more, (b)
The amount of the component and / or the component (c) is 50% by weight or less, and particularly preferably, the amount of the component (a) is 70% by weight or more, and the amount of the component (b) and / or the component (c) is 30% by weight or less. The higher the composition ratio of the component (a), the more excellent the chain transfer effect.

The α-methylstyrene dimer is usually synthesized by dimerizing α-methylstyrene. Various methods are known for the dimerization (Japanese Patent Application Laid-Open Nos. 54-48742, 49, 49).
No. 126656 gazette), and other methods may be used.

The α-methylstyrene dimer is an impurity, for example, unreacted α-methylstyrene, α-methylstyrene oligomer other than the components (a), (b) and (c), within a range that does not impair the object of the present invention, It may contain an α-methylstyrene polymer.

Further, the α-methylstyrene dimer can be used in an unpurified state after the synthesis of the α-methylstyrene dimer as long as it does not impair the object of the present invention.

As the other polymerization chain transfer agent used in combination with the α-methylstyrene dimer, a known polymerization chain transfer agent used in general emulsion polymerization can be used. Specifically, for example, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, t-
Mercaptans such as tetradecyl mercaptan; xanthogen disulfides such as dimethylxanthogen disulfide, diethylxanthogen disulfide, diisopropylxanthogen disulfide; thiuram disulfides such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide; carbon tetrachloride, bromide Halogenated hydrocarbons such as ethylene; hydrocarbons such as pentaphenylethane; and acrolein, methacrolein, allyl alcohol, 2-ethylhexyl thioglycolate, terpinolene, α-terpinene, γ-terpinene, dipentene and the like. it can. These may be used alone or in combination of two or more. Among these, mercaptans, xanthogen disulfides, thiuram disulfides, carbon tetrachloride and the like are preferably used.

When these other chain transfer agents are used in combination, the reactivity during polymerization can be increased, which is preferable.

The proportion of α-methylstyrene dimer in the polymerization chain transfer agent (I) is 5 to 100% by weight, preferably 10 to 100% by weight,
More preferably, it is 10 to 95% by weight. If the proportion of the α-methylstyrene dimer is less than 5% by weight, it is impossible to obtain a copolymer latex having excellent peeling strength and yarn removal strength.

The amount of the polymerization chain transfer agent (I) used is 100% of the monomer mixture.
It is 0.05 to 20 parts by weight, preferably 0.07 to 7 parts by weight per part by weight. If the amount of the polymerization chain transfer agent (I) used is less than 0.05 parts by weight, the peel strength and the yarn removal strength will be poor. On the other hand, when the amount used exceeds 20 parts by weight, the blister resistance is lowered, the peeling strength and the yarn removal strength are poor, which is not preferable, and the stability during polymerization is deteriorated.

The amount of α-methylstyrene dimer used is preferably 0.05 to 10 parts by weight per 100 parts by weight of the monomer mixture.

Next, the polymerization chain transfer agent used in the second invention (hereinafter referred to as the polymerization chain transfer agent (II)) is (a) at least one compound selected from terpinolene, α-terpinene, γ-terpinene and dipentene ( Hereinafter, "component (a)") and (b) at least one compound selected from alkyl mercaptans, carbon tetrachloride, xanthogen disulfides and thiuram disulfides (hereinafter referred to as "component (b)") Consists of.

Specific examples of the alkyl mercaptans of the component (b) include octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, t-tetradecyl mercaptan, n-hexadecyl mercaptan. . Of these, t-dodecyl mercaptan is preferably used.

Specific examples of the xanthogen disulfides include diethylxanthogen disulfide, dimethylxanthogen disulfide, diisopropylxanthogen disulfide and the like.

Specific examples of thiuram disulfides include tetramethyl thiuram monosulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram disulfide and the like.

The ratio of the component (a) in the polymerization chain transfer agent (II) is 5 to 95.
%, Preferably 10 to 90% by weight. If the proportion of component (a) of (II) in this polymerization chain transfer agent is less than 5% by weight or exceeds 95% by weight, the combined effect of components (a) and (b) cannot be obtained, and the object of the present invention is to It is impossible to obtain a carpet backing agent having excellent peeling strength, yarn removal strength and blister resistance.

The amount of the polymerization chain transfer agent (II) used is 100% of the monomer mixture.
It is 0.05 to 20 parts by weight, preferably 0.07 to 7 parts by weight per part by weight. If the amount of the polymerized chain transfer agent (II) used is less than 0.05 parts by weight, the peel strength and the yarn removal strength will be poor, and if it exceeds 20 parts by weight, the blister resistance will be reduced and the peel strength and the yarn removal strength will be poor, which is not preferable.

The amount of component (a) used is the monomer mixture.
It is preferably used in the range of 0.05 to 10 parts by weight per 100 parts by weight.

The copolymer latex in the present invention can be produced by a conventionally known emulsion polymerization method except that the above-mentioned monomer mixture and polymerization chain transfer agent are used.
That is, it can be obtained by adding a monomer mixture, a polymerization initiator, an emulsifier, a polymerization chain transfer agent and the like to an aqueous medium (usually water) to carry out emulsion polymerization.

The polymerization emulsifier used in the emulsion polymerization in the present invention is not particularly limited, for example, sodium dodecylbenzene sulfonate, sodium lauryl sulfate, sodium diphenyl ether disulfonate, sodium succinate dialkyl ester sulfonate, potassium oleate, alkylnaphthalene sulfonate. One or two of anionic emulsifiers such as sodium salts of formalin condensates, or nonionic emulsifiers such as polyoxyethylene alkyl esters and polyoxyethylene alkyl allyl ethers.
More than one species can be used. An emulsifier that can remarkably exhibit the effects of the present invention is an anionic emulsifier, and it is particularly preferable to use sodium diphenyl ether disulfonate and a sodium salt of an alkylnaphthalene sulfonic acid formalin condensate in combination.

The amount of emulsifier used is usually 0, based on the total weight of the monomers.
It is 2 to 0.4% by weight, preferably 0.5 to 3.0% by weight. When the use amount of the emulsifier is too small, such as coagulation is generated, the polymerization stability becomes poor, while when the use amount is too large, the average particle size of the copolymer latex becomes small, and in the production of the composition for carpet backing. The dispersibility of the filler, which will be described later, becomes poor, and the viscosity changes with time after compounding.

Next, the polymerization initiator used in the emulsion polymerization in the present invention is not particularly limited, and examples thereof include persulfate initiators such as potassium persulfate, sodium persulfate, and ammonium persulfate, cumene hydroperoxide, and isopropylbenzene. Examples thereof include organic oxides such as hydroperoxide, paramenthane hydroperoxide, and benzoyl peroxide, and hydrogen peroxide. The amount of the polymerization initiator used is preferably 0.03 to 2.5 with respect to the total weight of the monomers.
%, Particularly preferably 0.05 to 2.0% by weight.

In order to accelerate the emulsion polymerization, for example, sodium pyrobisulfite, sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, glucose, formaldehyde, sodium sulfoxylate, L-ascorbic acid, a reducing agent such as sodium hydrogen sulfite, Glycine, alanine,
A chelating agent such as sodium ethylenediaminetetraacetate can also be used in combination.

Further, the preferred glass transition temperature (Tg) of the copolymer latex is + 30 ° C to -50 ° C. Tg is + 30 ℃
If it becomes higher, the soft feeling of the carpet cannot be obtained. On the other hand, when Tg is lower than -50 ° C, the peeling strength and the yarn removal strength of the carpet are poor, and a good carpet cannot be obtained.
The glass transition temperature (Tg) in the present invention is a value calculated by the following formula.

W (i); weight fraction of monomer (i) of copolymer Tg (i); Tg of homopolymer of monomer (i) expressed as an absolute value. The glass transition temperature of the coalescence is as follows: poly (1,3-butadiene) = 183 ° K, polystyrene = 373 ° K, polymethylmethacrylate = 378 ° K, polymethacrylic acid = 501 ° K, polyitaconic acid = 553 ° K,
Polyacrylic acid = 379 ° K, polyacrylonitrile = 376
K, 2-ethylhexyl polyacrylate = 203 K.

In addition, in the emulsion polymerization, in addition to the emulsifier, the chain transfer agent, the polymerization initiator, and the like, various electrolytes, a pH adjusting agent, and the like can be used in combination, if necessary.

The emulsion polymerization method and its conditions in the present invention are not particularly limited, and can be carried out under the conventionally known methods and conditions.

For example, the addition method of the polymerization chain transfer agent may be a batch addition method, a divided addition method, a continuous addition method, or a combination thereof.

The addition method of the monomer mixture may be a batch addition method, a divided addition method, a continuous addition method, or a combination thereof.

And, for example, with respect to 100 parts by weight of the monomers (a) to (c), 80 to 300 parts by weight of water, the emulsifier, the chain transfer agent, the polymerization initiator and the like are used in an amount within the above range. Under the polymerization conditions of a polymerization temperature of 5 to 80 ° C., preferably 30 to 50 ° C. and a polymerization time of 15 to 30 hours, a copolymer latex having good polymerization stability can be obtained.

Next, examples of the inorganic filler used in the present invention include calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, barium sulfate, silicic acid, silicates, titanium oxide, magnesium carbonate, calcium carbonate and the like. However, the present invention is not limited to these.

These inorganic fillers may be used alone or in combination of two or more.

The ratio of the copolymer latex and the inorganic filler to be used is usually 30 to 800 parts by weight, preferably 1 to 100 parts by weight (solid content) of the copolymer latex.
It is from 00 to 700 parts by weight.

As described above, the carpet backing agent of the present invention is
The main component is a copolymer latex and an inorganic filler,
If necessary, a dispersant, an antifoaming agent, a crosslinking agent, a foaming agent,
Colorants, flame retardants, antiseptics, antiaging agents, stabilizers, vulcanization accelerators, antistatic agents, pH adjusters and the like can be added.

(Examples) Hereinafter, the present invention will be described more specifically with reference to Examples. In addition, "%" and "part" in an Example are weight standards.

(1) Production of Copolymer Latex Monomers 10 of various charging compositions shown in Tables 1 and 2
In addition to 0 parts, an emulsifier, a chain transfer agent and a polymerization initiator, 0.01 parts of sodium ethylenediaminetetraacetate, and 150 parts of water were charged into a stainless reactor having an internal volume of 100 and stirred at a polymerization temperature of 40 to 60 ° C. for 20 hours. Polymerization is carried out to obtain copolymer latexes A to H (Example) and copolymer latexes a to
n (comparative example) was obtained. Polymerization was carried out by batch charging, but all the obtained latexes had a polymerization conversion rate of 99.0% or more, good polymerization stability, and almost no coagulated product. The pH of each of the obtained copolymer latexes was adjusted to 8.0 with sodium hydroxide, and the solid content concentration was adjusted to 50% by heating under reduced pressure.

The α-methylstyrene dimer used here,
The α-methylstyrene dimer used in the following Examples and Comparative Examples is as follows.

Product Name: Nofiner MSD (NOF Corporation) group formed The gel contents of the copolymer latexes A to H and a to n are obtained by the following method.

The gel content is the ratio of the toluene insoluble portion of the copolymer latex, specifically, the latex is adjusted to pH 8,
The copolymer in the latex was coagulated with isopropanol, washed and dried to give a solid content of 0.3 g toluene 100 m
It is the weight ratio of the residual solid content to the total solid content obtained by immersing in l for 20 hours at room temperature and then filtering with a 120 mesh wire mesh.

(2) Adjustment of Carpet Backing Agent The copolymer backings A to H and a to n were used to prepare a carpet backing agent according to the following formulation. Carpet backing agent-containing copolymer latex 100 parts Sodium tripolyphosphate 1.0 part Polyoxyethylene nonylphenol ether 0.5 part Styrenated phenol 1.0 part Heavy calcium carbonate (added last) 350 parts Viscosity after sufficiently dispersing these compounds Is 25000-3
0000cps (Brookfield viscometer, BM type No.4-6rpm
(Measured under the conditions described above), a fixed component was adjusted to 73% with a thickener and water, and used in the following various tests for evaluation. The result is the third
It is shown in Tables and Table 4.

Peel strength Measured by the rug test method of JIS L-1021. That is, a composition for backing with a solid content concentration of 73% was applied at a rate of 1 kg (Wet) / m ² to a raw fabric made by tufting nylon crimped yarn on a polypropylene primary base fabric, and then used as a secondary base fabric. The ounce jute was pressure-bonded and stuck together, dried at 120 ° C. for 20 minutes, and then the peel strength between the secondary base cloth and the raw fabric was measured.

Pull-out strength According to JIS L-1021, the pull-out strength of one pile was measured under the same conditions as above.

A carpet prepared according to the same conditions as above according to JIS L-1201 was measured using an Olsen type bending resistance tester. The smaller the number, the softer the texture of the carpet.

 The above results are summarized as follows.

All of Examples 1 to 8 are within the scope of the present invention, and carpet backing agents excellent in peeling strength and yarn removal strength in soft feeling are obtained. Note that Examples 1 to 4 relate to the first invention, and Examples 5 to 8 relate to the second invention.

Comparative Example 1 is an example in which the use ratio of the two kinds of polymerization chain transfer agents in the first invention is out of the range of the invention, and both the peel strength and the yarn removal strength are small.

Comparative Examples 2 to 4 are examples in which the amount of the polymerization chain transfer agent in the first invention is out of the range of the invention, and both the peel strength and the yarn removal strength are small.

Comparative Examples 5 and 6 are examples in which butadiene is out of the range of the invention in the monomer composition in the first invention, and the soft handability, peel strength, and yarn removal strength are poorly balanced.

Comparative Example 7 is an example in which the ethylenically unsaturated carboxylic acid monomer in the monomer composition in the first invention is out of the range of the invention, and the soft hand property, the peel strength and the yarn removal strength are poorly balanced. .

Comparative Example 8 is an example in which the use ratio of the two kinds of polymerization chain transfer agents in the second invention is outside the range of the invention, and the peel strength and the yarn removal strength are small.

Comparative Examples 9 to 11 are examples in which the amount of the chain transfer agent in the second invention is outside the range of the invention, and both the peel strength and the yarn removal strength are small.

Comparative Examples 12 and 13 are examples in which butadiene is out of the range of the invention in the monomer composition in the second invention, and the soft handability, peel strength, and yarn removal strength are poorly balanced.

Comparative Example 14 is an example in which the ethylenically unsaturated carboxylic acid monomer in the monomer composition in the second invention is out of the range of the invention, and the balance of soft hand property, peeling strength, and yarn removal strength is poor. .

[Effects of the Invention] The carpet backing agent of the present invention is excellent in the soft feel of the resulting carpet, and also in its peeling strength and yarn removal strength, and the balance between the two is extremely good. Therefore, the carpet backing agent of the present invention can be suitably used in a wide range from contracts to simple household rugs.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Hiraharu 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (56) Reference JP-A-64-77682 (JP, A) Kai 63-249782 (JP, A) JP 52-103588 (JP, A) JP 63-154712 (JP, A) JP 61-155413 (JP, A)

Claims (2)

[Claims] 1. An (a) aliphatic conjugated diene having 2 to 10 carbon atoms.
At least one monomer selected from the group consisting of alkyl acrylates having an alkyl group and methacrylic acid alkyl esters having an alkyl group having 6 to 14 carbon atoms.
To 70% by weight, (b) 0 to 8% by weight of ethylenically unsaturated carboxylic acid, and (c) 22 to 98% by weight of another monomer copolymerizable with the above (a) and (b). The mixture of monomers (100 parts by weight in total) was added to the mixture 1
A copolymer latex obtained by emulsion polymerization in an aqueous medium in the presence of 0.05 to 10 parts by weight of α-methylstyrene dimer as a chain transfer agent per 00 parts by weight, and an inorganic filler as a main component. Carpet backing agent. 2. (a) Aliphatic conjugated diene having 2 to 10 carbon atoms.
At least one monomer selected from the group consisting of alkyl acrylates having an alkyl group and methacrylic acid alkyl esters having an alkyl group having 6 to 14 carbon atoms.
To 70% by weight, (b) 0 to 8% by weight of ethylenically unsaturated carboxylic acid, and (c) 22 to 98% by weight of another monomer copolymerizable with the above (a) and (b). The mixture of monomers (100 parts by weight in total) was added to the mixture 1
(B) 5 to 95% by weight of at least one compound selected from (a) terpinolene, α-terpinene, γ-terpinene and dipentene, and (b) alkyl mercaptans, carbon tetrachloride, xanthogen disulfides and thiuram. Polymerization chain transfer agent consisting of 95 to 5% by weight of at least one compound selected from disulfides
A carpet backing agent comprising a copolymer latex obtained by emulsion polymerization in an aqueous medium in the presence of 0.05 to 20 parts by weight and an inorganic filler as main components.