JPS6290376A - Composition for carpet backing - 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 Field of Application) The present invention relates to a backing composition for rugs such as carpets, needle punches, mats and the like. More specifically, the present invention relates to a rug backing composition that has excellent moldability of the backing layer, thereby exhibiting excellent cosmetic effects, and also has water resistance, heat resistance, weather resistance, and high compression recovery rate after long-term use. be.

(Prior Art) Conventionally, as a rug backing composition, natural rubber, S
Various additives such as foaming agents, foaming aids, crosslinking agents, anti-aging agents, thickeners, foam stabilizers, dispersants, gelling agents, fillers, etc. are appropriately combined with rubber latex such as BR, NBR, CR, etc. A backing agent containing a mixture of recent years,
As lifestyles change and needs diversify due to the development of the housing industry, backing agents have come to be used for rugs that come into contact with water, such as entrance mats, kitchen mats, and bathroom mats. In the case of such a backing layer, the alkali resistance and water resistance of the backing layer are insufficient, and furthermore, there are drawbacks such as poor weather resistance against outdoor sunlight drying.

For this reason, there is a problem in that if these rugs get wet or have dirt attached to them and are washed with water, they cannot be used after that.

Generally, a method to improve weather resistance is to add large amounts of anti-aging agents, fillers, stabilizers, etc., but this may impair the stability of the backing composition, cushioning properties, foaming properties, etc. Furthermore, weather resistance has not been improved to a satisfactory degree.

Another proposed method for improving weather resistance is to use an emulsion with good weather resistance in rubber latex. For example, Japanese Patent Publication No. 54-28425 discloses a backing composition using a carboxy-modified acrylic copolymer emulsion. Although this backing composition has excellent weather resistance, it is difficult to gel and has poor moldability.As a result, the backing layer has a poor cosmetic effect on mechanical materials, etc., so it cannot increase its commercial value. It had many drawbacks such as low implantability and low compression recovery rate after long-term use.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned drawbacks, and provides a rug backing with excellent moldability, implantability, water resistance, cosmetic effect, compression recovery rate, foamability, and weather resistance. The present invention provides a composition for use.

(Means for Solving the Problems) As a result of extensive studies, the present inventors found that the above object could be achieved by using a copolymer latex obtained by polymerizing specific monomer components. Based on this knowledge, we have completed the present invention.

That is, the present invention provides (a) one or more monomers selected from acrylic acid alkyl esters having an alkyl group having 2 to 10 carbon atoms and methacrylic acid alkyl esters having an alkyl group having 6 to 14 carbon atoms; Weight% (b) 5-25% by weight of acrylonitrile and/or methacrylonitrile (Q) 0.1-1.2% by weight of unsaturated carboxylic acid (d) 0-20% by weight of other copolymerizable monomers 50% of acrylic copolymer latex with a glass transition temperature of 130°C to 5°C, which is obtained by copolymerizing monomers.
90 parts by weight (solid content) and 10 to 50 parts by weight (solid content) of rubber latex (total 100 parts by weight).

In particular, the present invention involves mechanically or chemically foaming a mixture of the above-mentioned acrylic copolymer and rubber latex to form a wet foam, which is applied to a substrate such as a carpet, dried, and cured to form a foam backing. This is a backing composition suitable for use as a backing composition.

The present invention will be explained in detail below.

(1) The 1,000 yen component of acrylic copolymer latex is 1
It consists of the following (a) to (d).

(a) Acrylic acid alkyl esters having an alkyl group of 2 to 10 carbon atoms are used, and those having 2 to 8 carbon atoms are particularly preferred. For example, ethyl acrylate (glass transition temperature of homopolymer (hereinafter the same) -22°C), acrylic acid n
-butyl (-52°C), 2-ethylhexyl acrylate (-55°C), and n-butyl acrylate is particularly preferred.

The methacrylic acid alkyl ester used is one in which the alkyl group has 6 to 14 carbon atoms. For example, lauryl methacrylate (-65℃), octyl methacrylate (-20℃
), hexyl methacrylate (-5°C).

The amount of these (meth)acrylic acid alkyl esters used is 60 to 90% by weight, preferably 65 to 85% by weight, and if it is less than 60% by weight, the 'rg of the copolymer becomes large,
The backing lacks flexibility and weather resistance. If it exceeds 90% by weight, the hardness of the backing will be insufficient.

(b) Acrylonitrile and/or methacrylonitrile are necessary to improve the strength, elasticity, and wash resistance of the backing, and the amount used is 5 to 25% by weight, preferably 1% by weight.
It is 0 to 20% by weight. If it is less than 5% by weight, the wash resistance of the backing will be low, and if it exceeds 25% by weight, the feel of the backing will be poor.

CQ) Unsaturated carboxylic acid is necessary for crosslinking the copolymer, stabilizing the latex, etc., and its usage amount is particularly important in the present invention. Preferably 0°2-0.9
Weight%. If it is less than 0.1% by weight, the adhesion of the backing will be insufficient, and if it exceeds 1.2% by weight, it will be difficult to gel the backing composition, which is particularly undesirable for foam backing.

As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, etc. can be used, and methacrylic acid is particularly preferred.

(d) The amount of other copolymerizable monomers used is 0 to 2.
0% by weight, preferably 0-15% by weight. Examples of the monomer include methyl acrylate, methacrylic acid alkyl ester having an alkyl group having 5 or less carbon atoms, and aromatic vinyl monomers, with methyl methacrylate and styrene being preferred, and methyl methacrylate being particularly preferred.

By appropriately selecting the type and amount of monomer (d), the texture, strength, adhesiveness, viscosity, water resistance, heat resistance, etc. of the backing layer can be adjusted depending on the purpose.

It is important that the glass transition temperature (hereinafter sometimes abbreviated as Tg) of the acrylic copolymer obtained by copolymerizing the above monomers is -30 to 5°C. Tg is 130
If the Tg is below 5°C, the blocking resistance will be poor, and if the Tg exceeds 5°C, the texture of the backing will deteriorate.

The acrylic copolymer latex of the present invention is produced by an emulsion polymerization method. That is, the above-mentioned monomer mixture, a polymerization initiator, an emulsifier, a molecular weight regulator, etc. added thereto, and the like can be heated to about 40 to 90° C. while stirring to carry out polymerization. In this case, it is possible to polymerize by adding the monomer mixture continuously or intermittently.

The weight ratio of monomer/water during polymerization is 60 to 150 parts by weight of water per 100 parts by weight of the monomer mixture, taking into consideration the balance between the heat load during drying and the increase in viscosity during polymerization due to high solid fractionation.
Parts by weight, preferably 70 to 100 parts by weight.

As a polymerization initiator, acid salts such as ammonium persulfate, potassium persulfate, and sodium persulfate, or peroxidants such as hydrogen peroxide and cumene hydroperoxide are used, and if necessary, thiosulfate is used. It is also possible to carry out emulsion polymerization by redox reaction using a reducing agent such as soda or ferrous ammonium sulfate.

Examples of emulsifiers include anionic emulsifiers such as sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dioctyl sulfosuccinate, disodium dodecyl diphenyl ether disulfonemate, and nonionic emulsifiers such as polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether. Usual emulsifiers such as emulsifiers can be used, but sodium lauryl sulfate is particularly preferred. The amount of these emulsifiers used is usually 1. The amount is 0.1 to 3 parts by weight, preferably 0.3 to 1 part by weight per part by weight of OO.

In such emulsion polymerization, it is also possible to use a molecular weight regulator, such as n-dodecyl mercaptan, t-dodecyl mercaptan, dialkylxanthogen disulfide, etc. The amount of these molecular weight regulators used is 100 parts by weight of monomer. 0 to 5 parts by weight, preferably 0
~1 part by weight.

The rubber latex used is 10 to 50 parts by weight (solid content), preferably 20 to 45 parts by weight, based on 50 to 90 parts by weight (solid content) of the acrylic copolymer latex. Types of rubber latex include natural rubber latex, butadiene-based (co)polymer latex, latex such as SBR, carboxy-modified SBR, PBD, and NBR, and chloroprene latex, but natural rubber latex is particularly preferred, followed by SBH and the like. butadiene copolymer latex is preferred.

The combined use of rubber latex improves gelation, moldability, water resistance, and strength. If the amount of rubber latex is less than 10 parts by weight, these improvement effects will be small, and the strength will be particularly insufficient.

On the other hand, if it exceeds 50 parts by weight, the weather resistance and durability of the backing will deteriorate.

If desired, small amounts of flame retardants can be used in the compositions of the present invention to enhance flame retardancy. As the flame retardant, known ones can be used, such as phosphate esters, halogen-containing phosphate esters, ammonium triphosphate, antimony trioxide, zinc borate, barium metaborate, aluminum hydroxide, etc. .

Furthermore, fillers, emulsifiers, crosslinking agents, heat-sensitive gelling agents, etc. can be added to the composition of the present invention, if necessary. Examples of the crosslinking agent include phenol resin, amino resin, isocyanate, epoxy resin, melamine resin, zinc oxide, and the like. Examples of fillers include heavy calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, and the like. As the heat-sensitive gelling agent, organopolysiloxane is preferred.

Furthermore, a dispersant, an anti-aging agent, a bactericide, a thickener, etc. may be appropriately added to the composition, and the solid content may be 60 to 85% by weight.

The composition of the present invention is particularly suitable for use as a composite acid for foam backing, and its commercial value is further improved because a beautiful foam layer on the skin can be obtained through uniform foaming. Foaming is carried out by conventional mechanical methods such as continuous foaming machines, whippers, etc., or by chemical foaming using a blowing agent to form a wet foam, which is then used to make carpets, etc. It is particularly suitable for coating on the back side of a substrate, drying and curing to form a foam backing.

In addition, when foaming is used, a gel agent such as sodium silicofluoride is added.

Examples Hereinafter, the present invention will be explained in more detail by Examples.
The present invention is not limited to the following examples. In addition, in the examples, parts and % are parts by weight and weight %. In addition, the performance of the copolymer and backing composition obtained in the examples was measured by the following method. Measurement was performed using a differential thermal analyzer manufactured by Kawasaki.

Evaluation of foam backing mat tack The tackiness of the coated surface of the sample was determined by touch with a finger.

○: No tuck Δ: Slightly present ×: With tuck Texture The sample was measured using a cantilever method.

Strength After creating an emulsion film at room temperature, JIS
Measured according to K2SO3.

Compression Recovery Resiliency After applying a load to the coated surface of the sample with a finger, the recovery of dents on the coated surface was visually determined.

○: Immediately returns to normal.

Δ: Returns to normal but is slow.

×: Does not return to normal.

A sample of 10×15 CI+ was placed on a PVC tile that had been waxed in advance, and a load of 2 kg was applied, and the slip resistance was evaluated by touch.

O: Hardly any slippage.

Δ: Slightly slippery.

×: Slips well.

A weather-resistant sample was measured using a fade meter (manufactured by Suga Test Instruments Co., Ltd.).
After exposure for 00 hours, the state of deterioration was visually determined.

O: No discoloration or deterioration.

Δ: Discoloration, no deterioration.

X: Discoloration and significant deterioration.

The water-resistant sample was washed with a commercially available neutral detergent in a household washing machine, and the shape of the sample after dehydration was visually determined.

O: No change.

Δ: Slightly swells.

×: Does not retain its original shape.

The condition of the form embossed with the embossing roll was visually determined.

0: Good molding.

Δ: Insufficient molding.

×: Not typed.

Examples 1 to 5 A reactor was charged with 200 parts of distilled water, 0.2 parts of potassium carbonate, 0.03 parts of sodium acid sulfite, 0.3 parts of potassium persulfate, and the monomers and emulsifiers shown in Table 1. 50
The reaction was carried out at ℃ for 5 hours, and the polymerization conversion rate reached 98% or more in all cases, and an acrylic copolymer latex was obtained. The latex was adjusted to pH 6 with aqueous ammonia.

A foam backing composition was prepared using the following formulation A using these acrylic copolymer latex and natural rubber latex in the proportions shown in Table 1. After adding a crosslinking agent and a gelling agent to these according to the formulation shown in Formulation B, stir and foam with a whipper and apply to the back side of the carpet mat, -15= After heating and gelling, use an embossing roll. I typed the form. A foam-backed mat was prepared by drying and crosslinking at 120° C. for 30 minutes, and its physical properties were examined. The results are shown in Table 1.

Blend A Stabilizer (potassium oleate) 1.5 Dispersant (sodium tripolyphosphate) 0.2 Filler (aluminum hydroxide) 50 Thickener (sodium polyacrylate) 0.4 Blend B (polymerization part) Blend A 100 zinc white (5
0% dispersion) 2 Example 6 Same as Example 1 except that 60 parts (solid content) of the copolymer latex of Example 1 and 40 parts (solid content) of natural rubber latex were used as the polymer content of Formulation A. experimented on. The results are shown in Table 1.

Example 7 Example 2 except that 70 parts of butadiene and 30 parts of styrene were used as monomers, and 2 parts of potassium oleate was used as an emulsifier.
Polymerize in the same manner as 5BR (glass transition temperature -60°C)
Got latex.

An experiment was carried out in the same manner as in Example 1, except that 40 parts (solid content) of this latex and 60 parts (solid content) of the latex of Example 1 were used as the polymer of formulation A. The results are shown in Table 1.

Example 8 Polymerization was carried out in the same manner as in Example 1, except that 60 parts of butadiene, 28 parts of styrene, 10 parts of methyl methacrylate, and 2 parts of acrylic acid were used as monomers, and 2 parts of sodium dodecylbenzenesulfonate was used as an emulsifier. , carboxy-modified SBR
(Glass transition temperature -50°C) latex was obtained. 40 parts of this latex (solid content) and 6 parts of the latex of Example 1.
The experiment was conducted in the same manner as in Example 1, except that 0 part (solid content) was used as the polymer content of Formulation A. The results are shown in Table 1.

Comparative Examples 1 to 6 Copolymer latexes were obtained by polymerization in the same manner as in Example 1, except that monomers listed in Table 1 were used.

70 parts (solid content) of this latex and 30 parts (solid content) of natural rubber latex were blended, and the same experiment as in Example 1 was conducted. The results are shown in Table 1.

Comparative Example 7 The acrylic copolymer latex of Example 1 had a solid content of 40
The experiment was conducted in the same manner as in Example 1, except that 60 parts of natural rubber latex was used as a solid content. The results are shown in Table 1.

Comparative Example 8 The acrylic copolymer latex of Example 1 had a solid content of 95
The experiment was conducted in the same manner as in Example 1, except that 5 parts of natural rubber latex was used as a solid content.

The results are shown in Table 1.

As a result, the backing composition of the present invention was able to provide a good foam backing.

On the other hand, those outside the scope of the present invention have some drawbacks in tackiness, texture, strength, compression recovery, floor placement, etc.

(Effects of the Invention) The rug backing composition of the present invention has the following advantages over conventional weather-resistant backing compositions.

(1) Gelation is easy to prepare, and as a result, it is possible to obtain a rug with excellent moldability and a high commercial value due to the decorative effects such as patterns on the backing layer.

(2) It has excellent implantability and compression recovery rate during long-term use, and the original performance of the rug can be maintained over a long period of time.

(3) Since it has excellent water resistance and weather resistance, the rug can be used in places where it comes into contact with water, can be washed when soiled, and can even be dried outdoors in sunlight.

(4) In the foamed foam backing composition, the foam backing layer is uniformly foamed, and as a result, the skin is beautiful, the mechanical strength is excellent, and high foaming is possible.
Features excellent flexibility even in high foaming conditions

Claims (1)

[Scope of Claims] 1) (a) One or more monomers 60 selected from acrylic acid alkyl esters having an alkyl group having 2 to 10 carbon atoms and methacrylic acid alkyl esters having an alkyl group having 6 to 14 carbon atoms; -90% by weight (b) 5-25% by weight of acrylonitrile and/or methacrylonitrile (c) 0.1-1.2% by weight of unsaturated carboxylic acid (d) 0-20% by weight of other copolymerizable monomers 50% of acrylic copolymer latex with a glass transition temperature of -30°C to 5°C, which is obtained by copolymerizing monomers consisting of
A composition for a rug backing, characterized in that it contains ~90 parts by weight (solid content) and 10 to 50 parts by weight (solid content) of rubber latex (total 100 parts by weight). 2) A rug according to claim 1, wherein a mixture of acrylic copolymer latex and rubber latex is foamed to form a wet foam, which is applied to a substrate, dried and cured to form a foam backing. Backing composition.