JPH0772390B2 - Composition for carpet backing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for carpet backing, more specifically, it has good drying efficiency, high peeling strength and yarn removal strength, and a drying step after bonding. And a composition for carpet backing having good blister resistance.

[Conventional technology]

Conventionally, a composition for carpet backing is prepared by adding an inorganic filler and, if necessary, a dispersant, an aging stabilizer, a defoaming agent, a foaming agent, a cross-linking agent, etc. to a copolymer latex, and further adding a thickener to a suitable amount. It is manufactured by adjusting the viscosity.

Such a carpet backing composition is applied to all backed carpets such as tufted carpets, knitted carpets or hook carpets. In addition, as a backing method at that time, for example, in the case of tufted carpet, on the back surface of the raw machine obtained by tufting polypropylene tufted yarn such as nylon crimped yarn and polyester crimped yarn on a primary base fabric such as polypropylene. , Apply the composition for carpet backing and dry it with hot air, or
After applying the composition, a secondary base fabric such as jute woven fabric or synthetic fiber non-woven fabric is laminated and dried with hot air to obtain a tufted carpet.

Therefore, the required properties of the composition for carpet backing include high tufting yarn removal strength and high peel strength between the primary and secondary base fabrics in the manufacturing process or product, and good drying efficiency in the drying process. The blister resistance (no blistering) of the composition is required.

[Problems to be solved by the invention]

Unfortunately, however, no conventional carpet backing composition has been found that satisfies all the above-mentioned required properties.

In particular, in recent years, in the carpet manufacturing process, a drying method has been adopted in which a large-sized dryer (modular type) is used to increase the carpet running speed in a dryer under high temperature and high air flow conditions in order to improve productivity. However, in this method, there have been problems such as blister resistance, reduction in yarn removal strength due to insufficient drying, or reduction in peel strength between the primary and secondary base fabrics. In order to solve this problem, a composition for carpet backing having good drying property is desired, and a method for increasing the solid content concentration in the composition has been proposed. In this method, the fluidity and filling of the composition are improved. The dispersibility and viscosity stability of the agent are deteriorated, and the above problems have not been sufficiently solved. In addition, this method requires a high concentration of the copolymer latex, which is also problematic in the production of the copolymer latex. That is, in order to increase the concentration of the composition, for example, the particle size of the copolymer latex that constitutes the composition must be increased to cause a decrease in viscosity. It becomes a big problem.

An object of the present invention is to solve the above-mentioned conventional technical problems, and to provide a composition for carpet backing, which has high yarn removal strength and peeling strength, and has good drying efficiency and blister resistance in a drying step.

[Means for solving problems]

In order to achieve the above object, the present invention provides (a) an aliphatic conjugated diene monomer, an acrylate ester having an alkyl group having 2 to 10 carbon atoms, and a methacrylic acid having an alkyl group having 6 to 14 carbon atoms. 25 to 65% by weight of one or more monomers selected from esters, (b) 0.5 to 8% by weight of an ethylenically unsaturated carboxylic acid monomer, and (c) another monomer which is copolymerizable with these. Water-soluble cellulose ether having a gelation temperature of 40 to 80 ° C per 100 parts by weight of a copolymer latex (solid content) having an average particle size of 700 to 3000Å, which is obtained by emulsion polymerization of 27 to 74.5% by weight of the body. A carpet backing composition comprising 4 parts by weight and a filler.

In the present invention, as the aliphatic conjugated diene-based monomer which is the component (a) used in the copolymer latex,
Examples thereof include 1,3-butadiene, isoprene, and 2-chloro-1,3-butadiene, and among these, 1,3-butadiene is preferable.

Examples of the acrylate ester having an alkyl group having 2 to 10 carbon atoms include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.
Examples of the methacrylic acid ester having 14 alkyl groups include 2-ethylhexyl methacrylate and lauryl methacrylate. These aliphatic conjugated diene-based monomers, acrylic acid ester and methacrylic acid ester monomers can be used alone or in combination of two or more.

These monomers are essential components for imparting appropriate flexibility and adhesive strength to the obtained copolymer latex,
The proportion thereof is 25 to 65% by weight, preferably 30 to 60% by weight in the copolymer latex raw material. If it is less than 25% by weight, the flexibility and adhesive strength will be poor, while if it exceeds 65% by weight, the resulting carpet will be too soft and the peel strength will be low.

Examples of the (b) ethylenically unsaturated carboxylic acid monomer used in the present invention include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like.
These ethylenically unsaturated carboxylic acid monomers may be used alone or in combination of two or more, but a combination of acrylic acid and metal acrylic acid in an appropriate amount is preferable.
The amount of ethylenically unsaturated carboxylic acid monomer used is 0.5 to 8
%, Preferably 0.7 to 7.5% by weight. 0.5% by weight
If it is less than the above range, the stability of the latex during polymerization is poor and a coagulated product is likely to be produced, and the mechanical and chemical stability of the latex obtained is poor, and the resulting composition for carpet backing is not preferable because it changes over time. On the other hand, 8% by weight
When it exceeds, the latex obtained has a high viscosity and lacks practicality.

Further, (c) other monomers copolymerizable with the above monomers include aromatic vinyl compounds, vinyl cyanide compounds,
Examples thereof include vinyl acetate, acrylamide, alkyl methacrylate having 1 to 5 carbon atoms, and preferably 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 may be used alone or in combination of two or more. In particular, when methyl methacrylate is used as the other monomer for copolymerization, the polymerization stability can be remarkably improved, and thus it is preferably applied.

The amount of these other monomers (c) used is 27 to 74.5% by weight, preferably 30 to 69.5% by weight in the copolymer latex raw material. With a composition for carpet backing using less than 27% by weight of latex, the obtained carpet feel becomes too soft, while when it exceeds 74.5% by weight, it becomes too hard on the contrary, which causes trouble in handling and construction. The main physical properties of the yarn removal strength and the peel strength from the secondary base fabric are poor.

The present invention is to first obtain a copolymer latex by emulsion polymerization of the above monomers, where the emulsifiers are sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium diphenyl ether disulfonate, and succinic acid. One or more anionic emulsifiers such as sodium dialkyl ester sulfonate and nonionic emulsifiers such as polyoxyethylene alkyl ester and polyoxyethylene alkyl allyl ether can be used. In particular, as an emulsifier that can remarkably exhibit the effects of the present invention, sodium diphenyl ether disulfonate can be mentioned.

The amount of the emulsifier used is usually 0.2 to 4.0% by weight, and preferably 0.5 to 3.0% by weight (hereinafter the same) based on the total weight of the monomers. When the amount of the emulsifier used is too small, such as coagulation, the polymerization stability deteriorates, while when the amount used 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.

Further, as the chain transfer agent used for lowering the degree of polymerization in the polymerization reaction and causing an almost ideal chain transfer reaction, t-dodecyl mercaptan, octyl mercaptan, n-tetradecyl mercaptan, octyl captan, t The mercaptans such as -hexyl mercaptan and n-hexyl mercaptan, and halogen compounds such as carbon tetrachloride and ethyl bromide are usually used in an amount of 0 to 0.5% by weight.

Further, as the polymerization initiator, persulfate-based initiators such as potassium persulfate, sodium persulfate, and ammonium persulfate, organic substances such as cumene hydroperoxide, isopropylbenzene hydroperoxide, paraffin hydroperoxide, and benzoyl peroxide. Examples thereof include peroxides and hydrogen peroxide. Particularly, when cumene hydroperoxide is used, a copolymer latex having excellent drying efficiency, which is the object of the present invention, can be obtained. The amount of the polymerization initiator used is preferably 0.03 to 2.5% by weight,
It is 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, A chelating agent such as glycine, alanine, and sodium ethylenediaminetetraacetate can also be used in combination.

In emulsion polymerization, in addition to the emulsifier, chain transfer agent, polymerization initiator, etc., various electrolytes, pH adjusters, etc. may be used in combination, if necessary. For example, 100 parts by weight of the monomers (a) to (c) are added. On the other hand, 100 to 300 parts by weight of water and the emulsifier, chain transfer agent, polymerization initiator and the like are used in an amount within the above range and the polymerization temperature is 5 to 80
C., preferably 30 to 50.degree. C., under a polymerization condition of a polymerization time of 15 to 30 hours, the average particle diameter in the obtained copolymer latex is
It is performed so as to be 700 to 3000Å, preferably 750 to 2800Å. When the average particle size obtained is less than 700Å, the blister resistance is poor, and the viscosity of the carpet backing composition changes with time. On the other hand, when it exceeds 3000 liters, it is necessary to use a large amount of water-soluble cellulose ether, which is a thickener described later, which is not preferable in terms of price. Further, the fluidity of the composition for carpet backing is lowered and the workability is deteriorated.

The method of adding each of the monomers (a) to (c) at the time of emulsion polymerization is not particularly limited, and an arbitrary method such as a batch addition method, a continuous addition method or a divided addition method is adopted.

The polymerization conversion rate of the obtained copolymer latex is preferably 99.0% or more.

Incidentally, the average particle size of the copolymer latex, after treating the copolymer latex with osmic acid, by taking an electron microscope photograph of 30,000 times, by measuring the particle size of 100 particles by number average Desired.

The composition for carpet backing of the present invention usually has a viscosity of 20,000 to 40,000 cps, preferably 25,000 to 35,000 c.
ps, and its solid content concentration is 55 to 85% by weight, preferably 60
It is prepared by adding a water-soluble cellulose ether which is a thickener and, if necessary, water so that the content becomes -80% by weight. If the viscosity is less than 20,000 cps, the permeability to the carpet becomes large and the peel strength becomes weak. Meanwhile, 40,000 cps
If it exceeds the range, the coatability deteriorates and unevenness occurs. Further, if the solid content concentration is less than 55% by weight, the water content is too much and the drying efficiency is poor, and as a result, the yarn removal strength and the peeling strength may decrease, and if it exceeds 85% by weight, the viscosity increases and the coating efficiency increases. Deterioration or uneven coating causes variations in quality such as peel strength and feeling.

Examples of the water-soluble cellulose ether, which is a thickener used in the present invention, include methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose and the like, of which hydroxypropyl methyl cellulose is most preferable. Thickening of these water-soluble cellulose ethers such as sodium polyacrylate, carboxymethyl cellulose, hydroxymethyl cellulose,
You may use together 20% by weight or less what has a water retention function or fluidity.

When the thickener was gradually heated, a sharp increase in viscosity was observed,
The temperature at which the gelled state is reached is called the gelling temperature. The gelling temperature of the water-soluble cellulose ether used in the present invention is 40 to 80.
C, preferably 50 to 75C. If it is less than 40 ° C, the stability of the carpet backing composition is poor, and if it exceeds 80 ° C, the blister resistance is poor.

The amount of the water-soluble cellulose ether added in the present invention is 0.2 with respect to the copolymer latex weight part (solid content).
-4 parts by weight, preferably 0.5-3.5 parts by weight. If it is less than 0.5 part by weight, the blister resistance is poor, and if it exceeds 4 parts by weight, the viscosity of the composition is too high and the fluidity is poor, which is not preferable in processing.

In the present invention, the gelling temperature is 40 to 80 ° C. as a thickening agent, by using a water-soluble cellulose ether, the drying efficiency of the composition for carpet backing is good, and the peel strength,
The reason why the yarn removal strength is high and the blister resistance is good in the drying process after laminating is not always clear, but during drying, the moisture starts to evaporate and gels before reaching the temperature, which causes adverse effects due to blister and heating. It is considered that the product can be ideally produced by preventing gelation and releasing gelation upon completion of drying and cooling.

If the gelling temperature is not within the above range even with a cellulose ether diameter, the blister resistance is insufficient, and the water content of the carpet and the peel strength of the carpet / jute are poor. That is, the thickening agent that can be used in the present invention, the gelling temperature of the water-soluble cellulose ether is 40 ~ 80 ℃.
It was only prepared in. Even when the gelling temperature is within the above range, non-cellulose ether type polyvinyl alcohol, polymethacrylic acid, etc. have an insufficient blister resistance, and the moisture content of the carpet and the peel strength of the carpet / jute are poor, which is not preferable. .

Next, as the filler used in the present invention, inorganic filler such as calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, barium sulfate, silicic acid, silicate, titanium oxide, magnesium carbonate, calcium carbonate, etc. Agents may be included, but are not limited to. These fillers may be used alone or in combination of two or more.

The use ratio of the copolymer latex and the filler is not particularly limited, but usually 50 to 800 parts by weight of the filler, preferably 150 to 700 parts by weight, relative to 100 parts by weight (solid content) of the latex. It is a degree.

As described above, the composition for carpet backing according to the present invention contains a copolymer latex, a specific water-soluble cellulose ether and a filler as main components, but if necessary, a dispersant, a defoaming agent, and a crosslinking agent. , Foaming agent, colorant, flame retardant,
Preservatives, anti-aging agents, stabilizers, vulcanization accelerators, antistatic agents, pH adjusters and the like can be added.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

The parts and% in the examples are by weight unless otherwise specified.

Various test methods in the examples are as follows.

(1) Peel strength Measured by the rug test method of JIS L-1021. That is, a backing composition having a solid content of 68% was applied to a raw fabric made by tufting nylon crimped yarn on a polypropylene primary base cloth, and then 7 ounce jute was bonded as a secondary base cloth by pressure bonding. After drying at ℃ × 20 minutes, the peel strength between the secondary base cloth and the raw fabric was measured.

(2) Initial peel strength A backing composition having a solid content of 68% is applied to a raw fabric made by tufting nylon crimped yarn on a polypropylene primary base cloth, and then 7 ounce jute is press bonded as a secondary base cloth. The peel strength at the initial stage (5 minutes and 8 minutes after laminating) after laminating and drying at 120 ° C. was measured according to JIS L-1021.

(3) Blister resistance The undried carpet was placed in a hot air dryer at a temperature of 180 ° C. and visually observed for blisters (fire blisters) generated during drying. The judgment was carried out in the grades 1 to 5.
The 1st grade had no blister and was 5
A class hub lister is generated on the entire surface.

(4) Moisture content Using a wood moisture meter (Ket Co., M-SA type), a needle was pierced from the secondary base cloth side of the carpet to measure the moisture content of the carpet. When the water content is high, the peel strength at the initial stage of drying is weak, and the dryness after processing (drying at 120 ° C for 20 minutes) is poor, and thus the peel strength of the product is weak.

Examples 1 to 6 and Comparative Examples 1 to 13 In addition to 100 parts of monomers of various charging compositions shown in Table 1, an emulsifier, a chain transfer agent and a polymerization initiator, L-ascorbic acid 0.07 part, sulfuric acid first Iron 0.005 parts, sodium ethylenediaminetetraacetate 0.01 parts and water 200 parts 100
In a stainless steel reactor at a polymerization temperature of 35-60 ° C for 20
Polymerization is carried out by stirring for a time, and copolymer latex AK
Got Polymerization was carried out by batch charging, but the polymerization conversion rates of all the obtained latexes were 99.0% or more, the polymerization stability was good except for latex F, and there was almost no coagulated product.

Table 1 also shows the polymerization rate and average particle size of the obtained copolymer latex. The average particle diameter is a value measured according to the above-mentioned microscope method.

Next, the copolymer latexes A to K100 thus obtained
To parts by weight (solid content), in addition to the composition having the composition shown in Table 2, 0.8 parts by weight of potassium pyrophosphate, 1.5 parts by weight of polyoxyethylene nonylphenol ether, and 1.0 part by weight of styrenated phenol were added (however, filling The agent, heavy calcium carbonate, was added last), after thoroughly dispersing,
Viscosity about 30,000cps (Brookfield viscometer, BM type N
The composition for carpet backing was prepared by adjusting water-soluble cellulose ether, which is a thickener, and water so as to be measured under the conditions of 6 rpm using o.4), and various carpet tests were conducted.

The results are shown in Table 2.

As is clear from Tables 1 and 2, Examples 1 to 6 using the copolymer latex of the present invention have high carpet peeling strength and good blister resistance.

On the other hand, in Comparative Examples 1 and 2, when a copolymer latex was used in which the amount of butadiene (a) the aliphatic conjugated diene monomer in the monomer charging composition was outside the range of the present invention, Example 3 is a case in which 2-ethylhexyl acrylate, which is an acrylic ester having an alkyl group, is outside the scope of the present invention. In both cases, the peeling strength and initial peeling strength of the composition for carpet backing are weak and the blister resistance is low. It is also bad, and the moisture content of the carpet is high.

In Comparative Examples 4 and 5, itaconic acid and acrylic acid, which are ethylenically unsaturated carboxylic acid monomers (b) in the monomer charging composition, are outside the scope of the present invention (Comparative Example 4 is less than the lower limit value, 5 is When the copolymer latex having the upper limit value) is used, the dryness of the carpet backing composition is poor, and therefore the initial peel strength is weak and the peel strength after processing is weak.

Comparative Examples 6 and 7 are those in which the average particle size of the copolymer latex is outside the range of the present invention (Comparative Example 6 is less than the lower limit value and 7 is more than the upper limit value), but the composition for carpet backing is used. Has poor blister resistance, weak peel strength, and high water content.

In Comparative Examples 8 and 9, the composition of the copolymer latex was within the range of the present invention, and the amount of the water-soluble cellulose ether was outside the range of the present invention (Comparative Example 8 is less than the lower limit value, 9 is the upper limit value). However, the blister resistance is poor, the peel strength is weak, and the water content is high.

Comparative Example 10 is a case where the composition of the copolymer latex is within the range of the present invention and the gelling temperature of the water-soluble cellulose ether is outside the range, but the blister resistance is poor, the peel strength is weak, and the water content is There are also many.

Comparative Example 11 is a case where the composition of the copolymer latex is within the range of the present invention, and the type of thickener and the gelling temperature are outside the range of the present invention, but the blister resistance is poor and the peel strength is also It is weak and has a high water content.

Comparative Examples 12 and 13 are those in which the composition of the copolymer latex and the gel temperature of the thickener are within the scope of the present invention, and a non-cellulose ether outside the scope of the present invention is used as the thickener, but the blistering resistance is high. Poor property and weak peel strength.

〔The invention's effect〕

The carpet backing composition of the present invention has better dryness than conventional ones, the peel strength and the yarn removal strength of the resulting carpet are improved, and the blister resistance is also improved. Therefore, it is possible to increase the running speed during carpet drying, and it is possible to provide a composition for carpet backing suitable for a system that enhances productivity, that is, a drying system that uses a large-sized dryer and that operates at a high temperature and with a large air volume.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tatenuma 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (56) Reference JP-A-62-110987 (JP, A) JP 52-103588 (JP, A) JP-B 51-9078 (JP, B1)

Claims (1)

[Claims] 1. A compound selected from (a) an aliphatic conjugated diene monomer, an acrylate ester having an alkyl group having 2 to 10 carbon atoms and a methacrylic acid ester having an alkyl group having 6 to 14 carbon atoms. 25-65% by weight of one or more monomers,
(B) 0.5 to 8% by weight of an ethylenically unsaturated carboxylic acid monomer, and (c) 2 to 74.5 other monomers copolymerizable with them.
The average particle system obtained by emulsion polymerizing with wt% is 700 to 3
Water-soluble cellulose ether with a gelation temperature of 40-80 ℃ per 100 parts by weight of 000Å copolymer latex (solid content)
A composition for carpet backing, which comprises 0.2 to 4 parts by weight and a filler.