JPH0726327B2 - Adhesive composition for carpet backing - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive composition for lining a carpet used as an interior material for automobiles.

[Prior Art] Needle-punched carpets and tufted carpets for automobile interiors are manufactured by applying an adhesive composition containing styrene-butadiene copolymer latex or ethylene-vinyl acetate resin emulsion as a main component to the back surface of the carpet or After impregnation, 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-mentioned two-step processing method, a so-called one-step processing method is disclosed in Japanese Patent Laid-Open No. 53-52776, in which an aqueous plastic dispersion is applied to the back surface of a carpet to obtain a continuously moldable carpet. ing.

[Problems to be Solved by the Invention] In the conventional two-step processing method, the nonwoven 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. Further, the carpet is provided with thermoformability by backing a film of a thermoplastic resin, 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 that can be processed in one step and is excellent in all aspects of thermoformability, shape retention, and fiber adhesion.

[Means for solving problems]

In order to solve such a problem, the inventors of the present invention have conducted earnest research on a one-step processable adhesive composition for carpet backing, and as a result, have been proposed in Japanese Patent Laid-Open No. 53-52776. Rather than using known aqueous plastic dispersions and mixtures of such dispersions as backing adhesives,
When a mixture obtained by mixing the copolymer latexes (A) and (B) having a specific composition in a specific ratio is used as an adhesive for lining, thermoformability, shape retention and fiber The present invention has been completed by discovering the fact that an excellent effect is exhibited in all aspects of the fixing force.

That is, the present invention comprises 3 to 70% by weight of a maleimide monomer, 30 to 97% by weight of an aromatic vinyl monomer, and 0 to 67% by weight of another monomer copolymerizable therewith. Copolymer latex (A) 30 to 70 parts by weight (solid weight conversion value), butadiene 10 to 90% by weight, styrene 10 to 90% by weight
And a mixture of 70 to 30 parts by weight of a copolymer latex (B) composed of 0 to 80% by weight of another monomer copolymerizable therewith (solid content weight conversion value) as a main component. An adhesive composition for carpet backing is provided.

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. Further, 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.

Copolymer Latex (A) The copolymer latex (A) used in the present invention is a maleimide monomer 3 to 70% by weight, an aromatic vinyl monomer.
30-97% by weight and other monomers copolymerizable therewith
It consists of ~ 67% by weight.

If the maleimide-based monomer is less than 3% by weight or more than 70% by weight, the shape retention is poor. If the amount of the aromatic vinyl-based monomer is less than 30% by weight or exceeds 97% by weight, the shape retention is poor.

As the maleimide-based monomer, maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and the like can be mentioned, and one kind or two or more kinds can be used. N-phenylmaleimide is particularly preferable.

Examples of the aromatic vinyl-based monomer include styrene, α-methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, and the like.
More than one species can be used. Particularly, styrene and α-methylstyrene are preferable.

Examples of other copolymerizable monomers include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, methyl methacrylate, β-hydroxymethyl methacrylate, acrylonitrile, acrylamide, etc., and one or more types may be used. it can. The particle size of the copolymer latex (A) is preferably 50 to 300 nm, more preferably 50 to 150 nm.

Copolymer Latex (B) The copolymer latex (B) used in the present invention comprises 10 to 90% by weight of butadiene, 10 to 90% by weight of styrene, and 0 to 80% of another monomer copolymerizable therewith. Composed of weight percent.

If the butadiene content is less than 10% by weight, the fiber adhesion will be poor and 90
When it exceeds the weight%, the moldability is deteriorated. 10% by weight of styrene
If it is less than 90% by weight, the moldability is poor, and if it exceeds 90% by weight, the fixing strength of the fiber is poor.

Examples of other copolymerizable monomers include acrylic acid, methacrylic acid, fumaric acid, itaconic acid, methyl methacrylate, butyl acrylate, acrylonitrile, acrylamide, β-hydroxyethyl acrylate, and α-methylstyrene.

The particle size of the copolymer latex (B) is preferably 50 to 300 nm, more preferably 50 to 150 nm.

Latex Mixture The latex mixture used in the present invention is a copolymer latex (A) 30 to 70 parts by weight (solid content weight conversion value) and a copolymer latex (B) 70 to 30 parts by weight (solid content weight conversion value). ) Consists of. When (A) is less than 30 parts by weight, moldability and shape retention are inferior, and when it exceeds 70 parts by weight, the fiber fixing force is inferior. If (B) exceeds 70 parts by weight, moldability and shape retention are inferior, and if it is less than 30 parts by weight, the fiber fixing force is inferior.

The copolymer latexes (A) and (B) of the present invention are produced by a known method. That is, a batch addition method, a divided addition method, a continuous addition method, a two-stage polymerization method, a power feed method and the like can be applied.

The adhesive composition of the present invention may appropriately contain an antioxidant, a filler, a flame retardant, a thickener, a surfactant, a crosslinking agent and the like.

Carpets 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 for automobiles that require a heat molding step. Applies to carpets and interior materials.

As a method for applying or impregnating the adhesive composition of the present invention, an adhesive may be foamed or thickened and used, and as a processing method, a lick roll, a squeezing roll, a spray gun, dipping and the like can be mentioned. . Further, in order to completely impregnate the carpet, it is preferable to squeeze the applied adhesive composition with a squeezing roll. After coating or impregnating the adhesive composition, the moisture is removed by heating to obtain a moldable carpet.

Examples of the method for molding the carpet include a method of heating the carpet and molding it with a pressure roll or a press molding machine.

The carpet and interior materials for automobiles obtained by using the adhesive composition of the present invention may further be lined with a thermoplastic resin film such as polyethylene by heat fusion if necessary.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples.
The present invention is in no way limited by these examples. All parts and% in the examples mean parts by weight and% by weight, unless otherwise specified.

<Preparation of copolymer latex (A)> To 100 parts of water, 1.5 parts of sodium dodecylbenzenesulfonate is added and dissolved. The monomer mixture shown in Table 1 is added thereto, and 0.2 part of t-dodecyl mercaptan is further added to emulsify.

Next, 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 when the conversion of the monomers reached 97%. The unreacted monomer in the obtained latex was removed under reduced pressure to obtain copolymer latex A-1 to 3
And A-i and ii were obtained.

<Preparation of Copolymer Latex (B)> The same operations as those for the copolymer latex (A) were performed except that the amounts of the monomer mixtures shown in Table 2 were used, and copolymer latexes B-1 to 3 and B-i and ii were obtained.

Examples 1 to 3 and Comparative Examples 1 to 6 With respect to 100 parts (solid content) of the latex mixture shown in Table 3, an antioxidant (SUMILIZER S; Sumitomo Chemical Co., Ltd.)
1 part) and a surfactant (Emar 2FN; manufactured by Kao Soap Co., Ltd.) 1 part were added to obtain an adhesive composition having a solid content of 47%.

Each of the obtained adhesive compositions was foamed in a volume of 3 times with a Hobart mixer, coated on the back surface of a polypropylene / polyester blended needle punch carpet at a coating amount of 150 g / m ² , and was impregnated to the inside. After that, 130 ℃
The carpet sample obtained by drying for 5 minutes at
Moldability, shape retention and fiber fixing force were tested based on the following measuring methods.

The results are shown in Table-3.

Thermoformability; Carpet sample in oven at 180 ° C for 5
After heating for a minute, the uneven mold shown in Fig. 1 (A part: 90
And press molding (for 1 minute). This molded product was taken out of the mold and the angle of the A'section shown in FIG. 2 was measured and evaluated according to the following criteria.

○: More than 80 degrees (good) △: 75 to 80 degrees (insufficient) ×: Less than 75 degrees (poor) Shape retention: After evaluation of thermoformability, the molded product is again stored in an oven at 90 ° C for 24 hours Place

After that, it was taken out from the oven and the angle A ″ shown in FIG. 3 was measured. The change in this angle (A′−A ″) was evaluated according to the following criteria.

○: less than 10 degrees (good) △: 10 to 15 degrees (insufficient) ×: more than 15 degrees (poor) Fiber fixing force; rubbing the back side of the carpet sample with a metal piece, dropping off the adhesive and pilling the fiber Was evaluated based on the following criteria.

◯: Adhesive did not fall off or pilling was good. Δ: Adhesive fell off a little or pilling was slightly poor. X: Adhesive was dropped off (powder drop) or pilling was bad. [Effects of the present invention] The adhesive composition obtained in the present invention can simultaneously exhibit the moldability, shape retention property, and fiber fixing force required for automobile carpets, and the adhesive composition of the present invention. The product can omit the step of the two-step processing technology of lining the thermoplastic resin film, and also has the effects of simplifying the carpet manufacturing process and improving productivity.

[Brief description of drawings]

Fig. 1 is a cross-sectional view of the molding die, Fig. 2 is a cross-sectional view of the carpet after thermoforming, and Fig. 3 is a cross-section of the carpet after leaving the thermoformed carpet in an oven at 90 ° C for 24 hours. The figure is shown. B mold ... B carpet A ... angle when mold is attached (90 degrees) A '... angle after thermoforming A''... angle after standing in oven at 90 ° C for 24 hours

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location D06M 15/285 15/693

Claims (1)

[Claims] 1. A copolymer composed of 3 to 70% by weight of a maleimide monomer, 30 to 97% by weight of an aromatic vinyl monomer, and 0 to 67% by weight of another monomer copolymerizable therewith. From 30 to 70 parts by weight of the polymer latex (A) (solid content weight value), 10 to 90% by weight of butadiene, 10 to 90% by weight of styrene, and 0 to 80% by weight of other monomer copolymerizable therewith An adhesive composition for carpet backing, characterized in that a mixture of 70 to 30 parts by weight (converted to a solid content) of the copolymer latex (B) is used as a main component.