JPH0639745B2 - Adhesive composition for carpet backing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Purpose of the Invention [Field of Industrial Application] The present invention relates to an adhesive composition for lining a carpet used as an interior material for automobiles.

[Conventional technology]

Needle-punched carpets and tufted carpets for automobile interiors have a styrene-butadiene copolymer latex or an ethylene-vinyl acetate-based adhesive composition as a main component, which is applied or impregnated on the back surface of the carpet. It is manufactured by a two-step processing method in which a thermoplastic resin film such as polyethylene is lined by heat fusion in order to impart thermoformability.

These carpets are cut, molded by press molding at the time of heating according to the shape of the floor of the automobile, and then incorporated into the automobile.

On the other hand, unlike the above-described two-step processing method, a so-called one-step processing method is disclosed in JP-A-53-52776, in which a continuously moldable carpet is obtained by applying an aqueous plastic dispersion liquid to the back surface of the carpet. ing.

[Problems to be solved by the invention]

In the conventional two-step processing method, the non-woven fabric fiber or pile yarn is fixed by applying or impregnating an adhesive consisting of an aqueous emulsion of styrene-butadiene copolymer latex or resin, and further lining the thermoplastic resin film. This gives the carpet thermoformability, but such a two-step processing method complicates the carpet manufacturing process, and therefore improvement thereof has been desired.

On the other hand, in the one-step processing method for imparting thermoformability to the adhesive without backing the thermoplastic resin film, the thermoformability and the ability to maintain its shape (called shape retention) ) Is not sufficient, and there is a problem that if the thermoformability and the shape-retaining property are to be improved, the fixing force of the fiber is lowered.

Therefore, it has been desired to develop a backing adhesive composition for one-step processing, which is excellent in all aspects of thermoformability, shape retention, and fiber adhesion.

In order to solve such a problem, the present inventors have conducted diligent research on an adhesive composition for carpate lining for one-step processing, and as a result, the prior art is disclosed in JP-A-53-52776.
Copolymers (A) and (B) having a specific glass transition point, rather than using a known aqueous plastic dispersion and a mixture of the dispersions as a backing adhesive proposed in No.
When used as a backing adhesive, a copolymer latex that is present in the same copolymer particles in a specific ratio, respectively, has excellent effects in all aspects of thermoformability, shape retention and fiber fixing force. The present invention was completed by discovering the fact that the expression of

(B) Structure of the invention [Structure of the invention] That is, the invention is a copolymer (A) having a glass transition point of 80 to 140 ° C, 50 to 80% by weight, and -90 to 50 ° C.
An adhesive composition for carpet backing, characterized in that 50 to 20% by weight of the copolymer (B) having a glass transition point of 1) contains a copolymer latex present in the same copolymer particles. To do.

By coating or impregnating the adhesive composition of the present invention on the back surface of a needle punched carpet or a tufted carpet, an automobile carpet having excellent thermoformability and shape-retaining property and excellent fiber adhesion is obtained. Can be easily obtained. In addition, unlike the above-described two-step processing method, the present invention does not require backing of the thermoplastic resin film, and is therefore excellent in terms of simplification of the carpet manufacturing process and improvement of productivity.

Hereinafter, the present invention will be described in more detail.

The glass transition point of the copolymer (A) used in the present invention is
It is in the range of 80 to 140 ° C. The glass transition point is 80 ° C
When it is less than 140 ° C., the thermoformability is poor, and when it exceeds 140 ° C., the polymerization rate of the monomer used is slow and there is a problem of reduced productivity, which is not preferable. The monomer constituting the copolymer (A), styrene, aromatic vinyl such as α-methylstyrene, acrylic acid, methacrylic acid, fumaric acid, unsaturated carboxylic acids such as itaconic acid, methyl methacrylate, acrylonitrile, Examples thereof include butyl acrylate, 2-ethylhexyl acrylate, and butadiene, and a copolymer obtained by using an aromatic vinyl monomer in the range of 75 to 100% by weight is preferably used.

The glass transition point of the copolymer (B) used in the present invention is
It is in the range of −90 to 50 ° C. The glass transition point is -90
When the temperature is lower than 50 ° C, the shape retention property is poor, and when the temperature is higher than 50 ° C, the fixing strength of the fiber is lowered, which is not preferable. As the monomer constituting the copolymer (B), styrene, α-
Aromatic vinyl such as methylstyrene; unsaturated carboxylic acid such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid;
Examples thereof include butadiene, methyl methacrylate, acrylonitrile, butyl acrylate, 2-ethylhexyl acrylate, and the like. Aromatic vinyl monomers 0 to 84.5
A copolymer composed of 10% by weight, 15 to 99.5% by weight of Porphyra japonicus, and 0.5 to 20% by weight of a monomer copolymerizable therewith is preferably used.

In the copolymer latex used in the present invention, the above copolymers (A) and (B) are in a weight ratio of (A) :( B) = 50-80:
It must be present in the same copolymer particles in a proportion of 50 to 20. If the use ratio of the (A) is less than 50% by weight, the shape retention property is deteriorated, and if it exceeds 80% by weight, the fiber fixing force is decreased, which is not preferable. Further, if the use ratio of the (B) is less than 20% by weight, the fixing strength of the fiber is lowered, and if it exceeds 50% by weight, the shape retention property is lowered, which is not preferable. Further, when (A) and (B) are not present in the same copolymer particle, the shape retention is poor, which is not preferable. The morphology of the particles of the copolymer latex used in the present invention requires that (A) and (B) be present in the same copolymer particles, respectively, as described above.
Any of a core-shell (multilayer) structure, a salami-like structure, a network-like structure, a localized structure, or a combination thereof may be used. In order to obtain a copolymer latex in such a particle form, a multistage emulsion polymerization method is suitable, but two or more kinds of emulsion polymerization methods may be combined.

The adhesive composition of the present invention may contain compounding components such as a cross-linking agent, an antioxidant, an antioxidant, a filler, a flame retardant, a thickener, and a surfactant, if necessary.

Examples of the carpet to which the adhesive composition of the present invention can be applied include needle punched carpets and tufted carpets using fibers such as polypropylene, polyester, nylon, acrylic, and wool, and automobiles that require a heat molding step. It is applied to carpets and interior materials.

〔Example〕

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. All parts and% in the examples mean parts by weight and% by weight, unless otherwise specified.

Example-1 (Preparation of copolymer latex) Sodium dodecylbenzenesulfonate (1.5 parts) was added to 100 parts of water.
Add parts to dissolve. To this, the first-stage monomer mixture shown in Table 1 was added, and the tert. Add 0.2 parts of dodecyl mercaptan and emulsify.

Next, 0.5 parts of potassium persulfate was added, and the whole was heated to 60 ° C.
Then, emulsion polymerization was carried out. Polymerization conversion of monomer is 97
The polymerization was stopped when the percentage was reached. The unreacted monomer in the obtained latex was removed under reduced pressure.

Furthermore, after mixing the second-stage monomer mixture shown in Table 1 with the latex obtained by the first-stage polymerization, tert.
Dodecyl mercaptan (0.1 part) and potassium persulfate (0.5 part) were added, and the whole was kept at 60 ° C to carry out the second-stage emulsion polymerization. When the polymerization conversion rate of the monomer reaches 97%, the polymerization is stopped and the unreacted monomer is removed by decompression.
Copolymer latexes A to E were obtained.

The number of copolymer particles of each of the obtained copolymer latexes A to E was measured at the time when the first and second stages of polymerization were completed, and no increase in the number of particles was observed. It was

(Preparation of Adhesive Composition) For each of the obtained copolymer latexes A to E, 1 part of antioxidant (Sumilyzer S; Sumitomo Chemical Co., Ltd.) per 100 parts of copolymer latex (solid content) Manufactured), thickener 0.3 part (Aron A7150; Toa Gosei Chemical Industry Co., Ltd.)
(Manufactured by Kao Corporation) and 1 part of a surfactant (Emar 2FN; manufactured by Kao Soap Co., Ltd.) are added to give a solid content of 47% and a viscosity of 2000 cp
s adhesive composition was prepared.

(Test Results) Each of the obtained adhesive compositions 1 to 3 was bubbled with a Hobart mixer in a volume three times that of the polypropylene needle-punched carpet, and was applied at a coating amount of 150 gr / m ² to impregnate the interior. . Then, at 130 ℃ 5
The carpet samples obtained by drying for minutes were tested for thermoformability, shape retention and fiber fixing force based on the following measurement methods.

The results are shown in Table-2.

Thermoformability: The carpet sample was heated in an oven at 130 ° C. for 5 minutes and pressed with an uneven metal mold to imprint it. The angle formed was measured and evaluated according to the following criteria.

◯: More than 80 degrees (good) Δ: 75 degrees to 80 degrees (insufficient) X: Less than 75 degrees (poor) Shape retention: Carpet sample molded by the above thermoformability test in a 90 ° C. oven for 24 hours It was left to stand and the angle of the imprinted portion was measured. This change in angle was evaluated according to the following criteria.

◯: less than 10 degrees (good) Δ: 10 degrees to 15 degrees (insufficient) x: more than 15 degrees (poor) Fiber fixing force: rubbing the back surface of the carpet sample with a metal piece to cause the adhesive to fall off and the fiber The degree of pilling was evaluated based on the following criteria.

◯: Good pilling without dropping off of the adhesive Δ: Some pilling was found to be slightly defective due to some dropping off of the adhesive X: Poor pilling due to many drops of the adhesive (powder falling off) Comparative Example-1 Unit weight shown in Table-1 With the same body composition, the same operations as in Example-1 were carried out to obtain copolymer latexes FI. Example-1
The same operation was performed to prepare adhesive compositions ~.

Then, a carpet sample was prepared in the same manner as in Example-1 and tested for thermoformability, shape retention and fiber fixing force. The results are shown in Table-2.

Example-2 A copolymer latex J was obtained by the same procedure as in Example-1, except that the monomer composition in the first and second steps was as follows.

In addition, in the obtained copolymer latex J, when the number of copolymer particles was measured at the time of completion of the first-stage polymerization and the second-stage polymerization, respectively, an increase in the number of particles was not observed.

Thereafter, the same operation as in Example-1 was performed to prepare an adhesive composition, and the thermoformability, shape retention and fiber fixing force were tested. The results are shown in Table-3.

Comparative Example-2 Sodium dodecylbenzene sulfonate 1.5 in 100 parts of water
Add parts to dissolve. To this, 86 parts of styrene, 9.5 parts of butadiene, 2 parts of methyl methacrylate, 1 part of acrylic acid, 1.5 parts of fumaric acid and tert. Add 0.2 parts of dodecyl mercaptan and emulsify. Then, 0.5 part of potassium persulfate was added, and the whole was kept at 60 ° C. to carry out emulsion polymerization. The polymerization was stopped at the time when the polymerization conversion rate of the monomers reached 97%, and unreacted monomers in the latex were removed under reduced pressure to obtain a copolymer latex K of one-stage polymerization.

The theoretical composition of the copolymer latex K is almost the same as that of the copolymer latex J of Example-2.

Hereinafter, the same operation as in Example-1 was performed to prepare an adhesive composition, and the thermoformability, shape retention and fiber fixing force were tested. The results are shown in Table-3.

Comparative Example-3 Copolymer latexes L and M were obtained in the same manner as in Comparative Example-2 except that the monomer composition was changed as follows.

The obtained copolymer latexes L and M were L / M in terms of solid content.
The mixture was mixed at a ratio of M = 65 parts / 35 parts, an adhesive composition was prepared in the same manner as in Example-1, and the thermoformability, shape-retaining property and fiber fixing force were tested. The results are shown in Table-3.

C. Effect of the invention [Effect of the present invention] The adhesive composition obtained in the present invention can simultaneously exhibit the thermoformability, shape retention and fiber fixing force required for automobile carpets, and The adhesive composition of the invention can omit the step of the two-step processing technology of lining the thermoplastic resin film, simplifying the carpet manufacturing step,
It also has the effect of improving productivity.

Claims (3)

[Claims] 1. A copolymer (A) having a glass transition point of 80 to 140 ° C., 50 to 80% by weight, and a copolymer (B) having a glass transition point of −90 to 50 ° C., 50 to 20% by weight. Containing a copolymer latex each present in the same copolymer particle. 2. Aromatic vinyl monomer (A) is 75 to 100.
The adhesive composition for carpet backing according to claim 1, which is a copolymer comprising 25% by weight and 25 to 0% by weight of another monomer copolymerizable therewith. 3. (B) is an aromatic vinyl monomer 0-84.5
Adhesion for carpet backing according to claim 1, which is a copolymer comprising 15% by weight of butadiene, 15-99.5% by weight of butadiene and 0.5-20% by weight of another monomer copolymerizable therewith. Agent composition.