JPS6230172A - Carpet-backing adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a carpet-backing adhesive composition having excellent thermal deterioration resistance, by adding specific amounts of metal- sequestering agent and antioxidant to a specific butadiene copolymer latex. CONSTITUTION:The objective carpet-backing adhesive composition can be produced by compounding (A) 100pts.(wt.) (solid basis) of a butadiene copolymer latex containing 0.5-10(wt)%, preferably 1.0-5.0% ethylenic unsaturated dicarboxylic acid (e.g. fumaric acid) with (B) >=0.01pt., preferably 2-3pts. of a metal-sequestering agent (e.g. ethylenediaminetetraacetic acid) and (C) preferably 0.2-1.5pts. of an antioxidant [e.g. 2,2'-methylenebis(4-methyl-6-tert- butylphenol)].

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an adhesive composition for carpet backing having excellent heat deterioration resistance (oxidative deterioration prevention) performance.

(Prior art) Conventional carpet lining adhesive compositions include natural rubber latex, synthetic rubber latex, or resin emulsion, fillers, filler dispersants, anti-aging agents (antioxidants), vulcanizing agents, and vulcanization accelerators. It is obtained by blending , thickeners, etc., and is applied to the back side of the carpet material for the purpose of adhering the carpet material to a secondary base fabric such as jute and preventing the pile threads from being removed from the carpet material. It is used.

Among these, carpet lining adhesives mainly composed of styrene-butadiene copolymer latex modified with ethylene-unsodated carboxylic acid and calcium carbonate are widely used due to their excellent economic efficiency and adhesive strength. There is.

In recent years, as the demand for floor heating carpets has increased, the resistance of carpet backing adhesive compositions to oxidative degradation at high temperatures has become more important than ever. For this reason, various antioxidants such as phenolic antioxidants, phosphate compounds, and peroxide decomposers such as disulfides and thioethers can be added to adhesive compositions, either partially or in combination. Efforts have been made to improve resistance to deterioration.

(Problem to be solved by the invention) However, recently, carpets with a soft feel have become preferred, so a soft copolymer latex with a high butadiene content, which is particularly susceptible to oxidative deterioration, is used as the latex. In many cases, the addition of anti-aging agents alone cannot meet the recent high demands for prevention of oxidative deterioration.

(Means for Solving the Problems) As a result of intensive studies by the present inventors to solve the above problems, surprisingly, a butadiene copolymer latex modified with a specific ethylenically unsaturated dicarboxylic acid was found. The present inventors have discovered that an adhesive composition containing a metal sequestrant, a sequestering agent, and an antioxidant exhibits a high degree of antioxidant performance not previously available, and has thus arrived at the present invention.

That is, the present invention uses 0.1% by weight to 100 parts by weight (solid content) of a butadiene copolymer latex modified with 0.5% to 10% by weight of ethylenically unsaturated dicarboxylic acid.
The present invention provides a carpet backing adhesive composition containing at least parts by weight of a sequestering agent and an antiaging agent.

The butadiene-based copolymer latex used in the present invention is produced by emulsifying butadiene, ethylenically unsaturated dicarboxylic acid, and other copolymerizable monomers in an aqueous medium using known emulsifiers, polymerization initiators, chain transfer agents, etc. It can be easily obtained by polymerization methods well known to those skilled in the art.

The butadiene copolymer in the present invention is 0.5% to 10% by weight, preferably 1.0% to 5.0% by weight.
It is necessary to contain parts by weight of ethylenically unsaturated dicarboxylic acid. When a monocarboxylic acid such as acrylic acid or methacrylic acid is used as the unsaturated carboxylic acid, an adhesive with a high degree of antioxidant ability cannot be obtained even in the presence of a sequestering agent and an anti-aging agent. When used, the presence of sequestering agents and anti-aging agents results in adhesives having a specifically high degree of antioxidant performance.

Examples of unsaturated dicarboxylic acids include fumaric acid, maleic acid, itaconic acid, and esters thereof, which can be used alone or in combination.

In addition to unsaturated dicarboxylic acids, monocarboxylic acids can also be used in combination without reducing the antioxidant performance.

If the proportion of unsaturated dicarboxylic acid is less than 0.5M1-%, the chemical and mechanical stability of the latex will be insufficient, making it difficult to prepare an adhesive containing a large amount of calcium carbonate, which is not preferable. If it exceeds 10% by weight, the viscosity of the latex becomes very high (at about 50% concentration), and the water resistance of the dried film of the adhesive composition decreases significantly, which is not preferable.

Butadiene content in the butadiene copolymer of the present invention,
The types of other copolymerizable monomers are not particularly limited, but butadiene is about 30! The content is preferably in the range of i% to 70% by weight, and other copolymerizable monomers include aromatic vinyl compounds such as styrene and α-methylstyrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, Alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl acrylate, hydroxyethyl acrylate, (meth)acrylamide, and the like can be used.

The sequestering agent used in the present invention has the effect of inactivating or sequestering metal ions such as iron present in the adhesive, and the use of a metal deactivating agent (chelating agent) or a heavy metal sequestering agent are preferable, and include, for example, the following.

Ethylenediaminetetraacetic acid (EDTA), ethylenediaminediorthohydroxyphenylacetic acid (EDDMA), hydroxyethylethylenediaminetriacetic acid ff (EDTA-
OH), ethylenediaminetetrakis (methylenephosphonic acid), oxanilide.

Dicarboxylic acid dihydrazide, dicarboxylic acid bis-phenyl hydrazide, salicylic acid hydrazide.

N-Salicyloyl-N'-salicylidene hydrazide.

Bis-salicyloyl-dicarboxylic acid dihydrazide.

Bis-acylated dicarboxylic acid dihydrazide, salicyloyl-hydrazinotriazine.

The amount of metal sequestering agent used is 0.011 parts by weight or more per 100 parts by weight of the butadiene copolymer latex.

If the amount is less than 0.01 part by weight, the antioxidant performance of the adhesive will not improve. As the amount of sequestering agent increases, the antioxidant performance also improves, but when it is used in excess of about 2 to 3 parts by weight, there is almost no improvement in the antioxidant effect with increasing amount of sequestering agent, and approximately 31 parts by weight is observed. There is no point in using more than Kagebu.

The sequestering agent is insoluble in water and does not form a stable aqueous dispersion.
If it cannot be used, an aqueous dispersion can be prepared using a suitable solvent or emulsifier. Further, the metal sequestering agent may be used by being blended with other compounding agents during the preparation of the adhesive composition, or may be used by being blended with the butadiene copolymer latex in advance.

The type of anti-aging agent that can be used in the carpet lining adhesive composition of the present invention is not particularly limited, but one or more types of antioxidants such as phenolic antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants may be used. is preferred. As a phenolic antioxidant, 2. z-methylenebis(4-methyl-6-tert-butylphenol), 2.2'-
Methylene bis(4-ethyl-6-tert-butylphenol), 4,4'-butylene bis(3-methyl-
6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-7'tylphenol), styrenated phenol, 1,1,3-tris(2-
Methyl-4-hydroxy-5-tert-butylphenyl)butane, 1.3.5-trimethyl-2,4,6-
Examples of sulfur-based antioxidants include tris(3,5-tert-7"f-4-hydroxybenzyl)benzene, and examples of sulfur-based antioxidants include dilauryl, thiodipropionate,
Examples of the antioxidant include distearyl-thiodipropionate and 2-mercaptobenzimidazole, and examples of the phosphorus antioxidant include distearyl pentaerythritol diphosphite and tributylphosphite.

The amount of anti-aging agent used is preferably 0. The amount of IM is most preferably 0.2 to 1.5 parts by weight.

As the amount of antioxidant used increases, the antioxidant effect of the adhesive also improves, but if it is used in excess of about 2 to 3 parts, the increase in antioxidant effect will hardly improve the antioxidant effect. Most anti-aging agents are in powder form, so in actual use, they must be made into an aqueous dispersion using an emulsifier or a solvent or plasticizer if necessary, or an emulsified butadiene copolymer. It is preferable to add it during synthesis by polymerization.

The adhesive compositions of the present invention may further contain conventional formulations such as fillers such as calcium carbonate, dispersants, stabilizers, defoamers, thickeners and the like.

The adhesive composition of the present invention can be applied to the production of all carpets such as tufted carpets, needle punch carpets, knitted carpets, and hook carpets, but the dry film does not yellow even when heated at 150°C for 4 hours or more. Since it does not harden, it can be suitably used in the manufacture of carpets for floor heating, which requires an adhesive that exhibits little oxidative deterioration at high temperatures.

The present invention will be further explained in detail with reference to Examples below, where all parts and % in Examples and Comparative Examples mean parts by weight and % by weight.

Examples 1 to 6 110 parts of water, 3 parts of sodium dodecylbenzenesulfonate, 0.9 parts of sodium bicarbonate, sodium persulfate, and tF1 were placed in a temperature-controlled pressurized reactor equipped with a stirrer under a nitrogen atmosphere. Monomers and a chain transfer agent in the indicated proportions were added, and emulsion polymerization was carried out at 80° C. for 10 hours to obtain latexes of Examples 1 to 3. The polymerization rate was about 90-98%. Next, adjust the pH of the latex to 7 to 8 with caustic soda,
Steams) IJ tubing was performed to remove unreacted monomers.

Using the butadiene copolymer thus obtained, an adhesive composition for carpet backing having the formulation shown below was obtained.

Butadiene copolymer latex (solid content) 100 parts Calcium carbonate (LW4000-Shimizu Kogyo) 400 parts Anti-aging agent 2LX (bisphenol-based Kawaguchi Chemical) 1.0
Part TSA7341 (antifoaming agent, Toshiba Silicon) 00
6 parts Total solids 70% Viscosity 18000 cps (B
L, #4, 12rrXT1) A cast film with a thickness of INIL was prepared from the obtained adhesive composition and dried at room temperature for 24 hours. The dried film of the adhesive was then heated at 50° C. in an open gear for a certain period of time to conduct an oxidation acceleration test.

The evaluation was determined by grading the adhesive film into the following five grades depending on the degree of yellowing (compared to the blank).

Grade 5 No yellowing Grade 4 Slight yellowing Grade 3 or yellowing Grade 2 Severe yellowing Grade 1 Severe yellowing (brown) Film curing Examples 1 to 6
Heat resistance test using butadiene latex (
Accelerated oxidation test) The results are shown in Table 1.

Comparative Examples 1-2 A butadiene copolymer latex was obtained in the same manner as in Example 1 except that 2 parts of acrylic acid and methacrylic acid were used as unsaturated carboxylic acids, and the adhesive film was subjected to an accelerated oxidation test. . The results are shown in Table 1.

From Table 1, the antioxidant ability of the adhesive composition (dry film) containing a predetermined amount of a sequestering agent and an antiaging agent is excellent when a butadiene copolymer latex modified with an unsaturated dicarboxylic acid is used as the latex. However, when a butadiene-based copolymer latex modified with a monocarboxylic acid was used, it was found to be significantly inferior.

Examples 7 to 11 Adhesives were prepared in the same manner as in Example 1, except that the butadiene copolymer latex obtained in Example 1 was used and the type and blending ratio of the sequestering agent was changed, and oxidation promotion was performed. A test was conducted. The results are shown in Table 2.

Comparative Examples 3 to 4 Table 2 shows the oxidation acceleration test results of adhesive films obtained in Example I using a sequestering agent in a proportion outside the range of the present invention.

From the results in Table 1-2, it can be seen that the antioxidant performance of the adhesive film is considerably inferior if the adhesive composition does not contain a metal sequestering agent, or even if it does contain it, the amount is below the range of the present invention.

Examples 12 to 15 Using the butadiene copolymer latex obtained in Example 1, adhesives were prepared in the same manner as in Example 1, except that the type and blending ratio of the anti-aging agent were changed, and oxidation promotion was performed. A test was conducted. The results are shown in Table 3.

Comparative Examples 5-6 Table 3 shows the oxidation acceleration test results of adhesive films in Examples 12-15 in which no or a small amount of anti-aging agent was used.

From the results in Table 3, it can be seen that when the adhesive composition does not contain an anti-aging agent or contains only a very small amount of anti-aging agent, the anti-oxidation performance of the adhesive film is considerably inferior.

Table 1 Hiroshi 1・

Claims (1)

[Claims] Butadiene copolymer latex 1 modified with 0.5% to 10% by weight of ethylenically unsaturated dicarboxylic acid
An adhesive composition for carpet lining, characterized in that it contains 0.01 parts by weight or more of a sequestering agent and an anti-aging agent per 0.00 parts by weight (solid content).