JPH0236248B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a carpet that has excellent shape retention, flame retardancy, and heat resistance, and in particular provides a carpet that is useful as a floor covering material for automobiles. Conventionally, carpets have been backed with rubber latex such as styrene-butadiene rubber or butadiene-acrylonitrile rubber to prevent the pile of the original rug from falling out and to stabilize the shape. When applying to uneven areas, it is difficult to shape the rubber latex backing material due to its high impact resilience, and even when it is shaped, its shape is not sharp and its shape retention is insufficient. . Melt extrusion lamination backing using thermoplastic resins such as polyethylene and ethylene/vinyl acetate copolymers has also been carried out. However, in this case, it is possible to mold the carpet into an uneven shape by heating, and compared to the case where rubber-type latex is used as the backing material, the shaped carpet has superior shape retention ability and the shape remains unchanged. Although it has the advantage of being sharp, it has the disadvantage of being hard to the touch and having a poor pile yarn locking effect. As a method to compensate for the drawbacks of these backing materials, a rubber latex with polyethylene powder dispersed therein is used as a backing material, and this is applied to the original rug to impregnate it, heated and dried, and then heated and pressed to form the carpet. It was proposed to do so.
However, this backing material has the disadvantage that it is difficult to uniformly disperse polyethylene powder into the rubber-type latex, and it is also difficult to uniformly impregnate the raw material of the rug with the powder. In addition, a rubber-type latex backing material is applied and impregnated on the back side of the original rug, and after drying to remove moisture from the latex, a polyethylene film is melt-laminated on top of the latex backing, and then heated and pressurized. A method of manufacturing carpet by molding is generally in practical use, but this method has the disadvantage that two steps of backing and lamination are required for manufacturing. Furthermore, since the temperature inside closed automobile interiors in the summer has recently reached temperatures of over 80°C, a test item has been added to ensure that floor and trunk materials do not deform at temperatures of 100°C. For this purpose, excellent alternatives to rubber latex were investigated, and moldable binders such as acrylic resins, vinyl chloride/vinyl acetate copolymers, ethylene/vinyl acetate copolymers, and vinyl chloride/vinyl acetate/ethylene copolymers were used as moldable binders. Synthetic resin emulsions such as, etc. are increasingly being used as backing materials. In particular, acrylic resin emulsions are being used more often because they are superior in rigidity, moldability, and heat resistance compared to other copolymer emulsions. This acrylic resin emulsion is a resin emulsion obtained by emulsion polymerization of a copolymer of so-called soft monomers such as butyl acrylate and acrylonitrile and so-called hard monomers such as styrene and methyl methacrylate. The temperature is approximately 100℃ at most, and JIS-
D-0204 does not satisfy the requirement that the carpet maintain its shape at 120°C. The present inventors have discovered that the shape of carpets obtained using conventional rubber latexes and thermoplastic resin emulsions as backing materials is not perfect and the heat resistance is limited due to the fact that the backing materials used are amorphous or non-crystalline. Based on the assumption that this is due to the latex or emulsion of low-crystalline rubber or thermoplastic resin, when a highly crystalline vinylidene chloride copolymer aqueous emulsion was used as the backing material, the shape due to excipients was completely preserved. The present invention was completed based on the discovery that it is possible to obtain a laying material that is highly heat resistant and elastic, and that it also imparts flame retardance to the carpet. That is, the carpet that is a feature of the present invention is made by adding vinylidene chloride 83 as a backing material to the original carpet.
After applying or impregnating an aqueous emulsion of crystalline vinylidene chloride copolymer with a softening temperature of 140 to 190°C obtained by emulsion polymerization of ~97% by weight and 17 to 3% by weight of vinyl monomer, and drying. It is formed by heating and pressure molding. In the present invention, any material can be used as the raw material for the carpet, including natural fibers, chemical fibers,
Raw fabrics made from various fibers such as synthetic fibers can be used. In general, needle punches made from fibers such as wool, nylon, polyacrylonitrile, polyacetate, polypropylene, etc., tufted carpet fabrics with piles erected on a primary base fabric knitted with flat yarns, and needle punches as described above are used. A tufted carpet original fabric is used, with a primary base fabric on which piles are erected. In addition, the aqueous emulsion of highly crystalline vinylidene chloride copolymer used as the backing material coated or impregnated on the back side of these raw rugs is vinylidene chloride 83
An aqueous polymer obtained by emulsion polymerization of a polymerizable monomer mixture of ~97% by weight, preferably 85-92% by weight and vinyl monomer 17-3%, preferably 15-8% by weight in the presence of a polymerization initiator. This is an emulsion that penetrates into the raw material of the carpet rug, and the resin adheres to the fibers of this rug, which has the effect of maintaining the processed shape of the raw rug that has been heat-molded and improving the pile locking effect. has. The vinyl monomers used include monomers with vinyl groups such as methyl methacrylate, styrene, acrylonitrile, methacrylic acid, methyl acrylate, butyl acrylate, vinyl chloride, maleic anhydride, itaconic acid, acrylamide, and methacrylamide. can. In addition, the resin solid content concentration in the resulting aqueous emulsion is usually 20 to 60% by weight, and the diameter of the dispersed resin particles is 10μ (microns).
Below, it is preferably 0.05 to 1.0μ. And the softening temperature of highly crystalline vinylidene chloride copolymer is
The temperature is 140-190℃. This aqueous emulsion of highly crystalline vinylidene chloride copolymer is combined with synthetic rubber such as styrene-butadiene copolymer, methacrylate ester-butadiene copolymer, latex such as natural rubber, vinyl acetate-based, olefin-based, and vinyl chloride-based An aqueous emulsion of , acrylic resin, and styrene resin may be blended in the same amount of solids to further improve the rigidity of the resulting carpet. In particular, styrene 50-95% by weight and acrylic ester
Styrenic and acrylic ester copolymer emulsion obtained by emulsion polymerization of 50 to 5% by weight and 0 to 5% by weight of other vinyl monomers at a solid content of 10 to 5% by weight.
When used in combination up to 50% by weight, it has the advantage of improving rigidity without reducing heat resistance. In addition, calcium carbonate, aluminum hydroxide,
Additives such as clay, talc, barium sulfate, and dyes may also be incorporated into these emulsions. These emulsions are applied by a conventional method, generally using a roll coater, and the coating amount is usually 30 to 100% (solid weight) of the weight of the carpet material. The raw rug coated with the emulsion can be heated and dried by any method. For example, a heating cylinder, an infrared heating machine, a hot air dryer, a suction dryer, etc. can be used, but it is preferable to use a hot air dryer and a heating cylinder in combination. Also, drying
Although it can be carried out at 100 to 200°C, it is preferably carried out at 110 to 150°C from the viewpoint of preventing fiber deterioration.
Then, water is removed and a rug coated with crystalline vinylidene chloride copolymer is obtained. This rug is preferably placed in a constant temperature room at a temperature of 35-80℃
After being stored for 30 minutes or more to achieve high crystallization of the copolymer, the copolymer is heated to a temperature higher than its softening point and then press-molded to form an arbitrary shape. Since this crystalline vinylidene chloride copolymer has a glass transition point of -20 DEG to 0 DEG C. and a softening point of 185 DEG to 200 DEG C., a carpet backed with this copolymer has significantly improved heat resistance. The carpet according to the present invention obtained as described above has a structure in which a backing layer 2 of vinylidene chloride copolymer is provided on the back side of the original rug 1 as shown in FIG. The carpet 3 with significantly improved flame retardance can be constructed by the vinylidene chloride copolymer having milon units impregnated inside the carpet material 1. Examples and a backing material obtained by emulsion polymerization of 80 to 88% by weight of vinylidene chloride and 20 to 12% by weight of methyl acrylate on the ^back side of a needle punch carpet made of polyester fiber (fabric weight of 360 g/cm 2 ). An aqueous emulsion of crystalline vinylidene chloride copolymer (resin particle size 0.5 to 1.3μ, solid content concentration 50% by weight) was applied with a Ritzker roller at a concentration of 150 g/cm ² (solid content), and then a Nipprol was used to coat the emulsion. The needle punch carpet was impregnated with the emulsion. Then, after heating the emulsion-impregnated needle punch carpet at 120°C to remove moisture,
The resulting carpet was heated for 60 seconds with a far infrared heater with a surface temperature of 180°C to soften the vinylidene chloride copolymer, and then heated using a cooling press mold for 20 seconds.
The product was molded under a pressure of Kg/cm ² for 5 minutes to produce a carpet for the floor of an automobile interior. The carpets manufactured in this example and in this example have molding sharpness (◎: very excellent, 〇: excellent, △: average), heat-resistant shape retention (◎: no change at all, 〇: slight change, △ Evaluations regarding burn rate and combustion rate are shown first in comparison with Comparative Examples ~. Regarding heat-resistant shape retention, as shown in Fig. 2A, the carpet 4 based on the above example and the like was placed on a mold 5 with l = 45 mm and heated at 85°C for 100 hours or
The shape retention properties were observed when stored at 120°C for 20 hours and are shown in accordance with Figure 2B. The combustion rate was determined using the combustibility test method for organic materials for automobile interiors according to JIS-D-1201-1977.

【table】

[Table] The comparative example shown in Table 1 above uses styrene/butyl acrylate copolymer (styrene/butyl acrylate = 80/20) instead of an aqueous emulsion of crystalline vinylidene chloride copolymer as the backing material.
The evaluation was carried out on a carpet molded in the same manner as in the example except that an aqueous emulsion was used. In the comparative example, a flame-retardant emulsion of vinyl chloride/vinyl acetate/ethylene copolymer was used as the backing material. A carpet molded in the same manner as in the example was evaluated. Examples and as backing materials, aqueous emulsion of vinylidene chloride/methyl acrylate copolymer (PVDC) used in the above example and aqueous emulsion of acrylic resin (ACSM) used in the above comparative example.
Using a mixture of the following, carpets were evaluated in the same manner as in Table 1 above, together with comparative examples, under the same conditions as in the Examples, and the results are shown in Table 2 below.

【table】 [Brief explanation of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention, and FIGS. 2A and 2B are explanatory views showing a method for measuring the heat-resistant shape retention of a carpet. In the figure, 1 is a rug material, 2 is a backing material including a rug material layer, and 3 is a carpet.

Claims (1)

[Claims] 1 Add 83 to 97% by weight of vinylidene chloride as a backing material and 17 to 3% by weight of vinyl monomer to the original rug.
A carpet constructed by applying or impregnating an aqueous emulsion of a crystalline vinylidene chloride copolymer having a softening temperature of 140 to 190°C obtained by emulsion polymerization of the same, drying the product, and then heating and press-molding the product.