JP2005193524A - Polyolefin sheet for vehicle interior finish material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyolefin sheet for a vehicle interior finish material which has flame retardancy passing vehicle flame retardation specifications. <P>SOLUTION: In the polyolefin sheet, a heat-shrinkable polyolefin sheet-like material is laminated on the back of a polyolefin substrate sheet. The polyolefin sheet-like material is preferably a nonwoven fabric of uniaxially oriented polyolefin split yarns or a biaxially oriented polyolefin film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyolefin-based sheet used for an interior material of a vehicle such as an automobile. More specifically, the present invention relates to a polyolefin-based sheet for vehicle interior materials that passes vehicle flame retardant standards.

  Conventionally, polyvinyl chloride sheets have been used for interior materials of vehicles such as automobiles, such as sun visors, pillars, and ceilings. Polyvinyl chloride sheets have excellent properties in heat resistance, high-frequency welding processability, flame retardancy, and the like, but in recent years, polyolefin sheets have attracted attention from the viewpoint of unifying plastic materials for automobiles.

The interior material of a vehicle such as an automobile is required to have flame retardancy and needs to pass the vehicle flame retardant standard. Therefore, various resin compositions have been conventionally proposed as flame retardant sheets for vehicle interiors. For example, a flame-retardant interior sheet for vehicles made of a copolymer of maleic anhydride and methyl (meth) acrylate has been proposed (Patent Document 1). In addition, a flame retardant comprising a copolymer of ethylene and a polar group-containing vinyl polymer, an olefin resin having a melting point of 100 ° C. or higher, and a flame retardant such as a bromo flame retardant, an antimony flame retardant, or a phosphorus flame retardant. An olefin-based resin composition has been proposed (Patent Document 2). Furthermore, a resin sheet obtained by molding a composition in which an ethylene-vinyl acetate copolymer, a filler-containing high-density polyethylene, and a flame retardant are blended has been proposed (Patent Document 3).
JP 2000-198394 A JP 2000-198888 A JP 2002-161179 A

  An object of this invention is to provide the polyolefin-type sheet | seat for vehicle interior materials which has the flame retardance which passes a vehicle flame retardant specification.

  Conventionally, in order to obtain a flame-retardant synthetic resin sheet for use in vehicle interiors, as seen in the above-mentioned patent document, a synthetic resin having flame retardancy per se is used, or a synthetic resin blended with a flame retardant is used. Molded into a sheet. When the inventor burns a polyolefin-based sheet, the vicinity of the ignited flame is heated and softened, the ignited portion hangs down, and the flame spreads in the form of wrapping around from the bottom along this suspending portion. In view of the above, the present invention has been completed by realizing that it is possible to exert the flame retardancy by preventing the spread of the combustion by preventing the seat of the ignition portion from sagging.

  That is, the present invention is a polyolefin-based sheet for vehicle interior materials, which is obtained by laminating a polyolefin-based sheet-like material having a property of shrinking when heated on the back surface of a polyolefin-based sheet as a base material. The polyolefin sheet material is preferably a uniaxially stretched polyolefin split yarn nonwoven fabric. The polyolefin sheet is preferably a biaxially stretched polyolefin film.

  As described above, when the polyolefin-based sheet is burned, the vicinity of the ignited flame is heated and softened, the ignited portion hangs down, and the flame spreads from the bottom along the hang-down portion and the combustion spreads. This phenomenon also occurs during the actual combustion of the interior material in the vehicle. Since the polyolefin-based sheet for vehicle interior materials according to the present invention is laminated on the back surface of the polyolefin-based sheet of the base material with a polyolefin-based sheet material having a property of shrinking when heated, when the sheet is heated with a flame, Since the polyolefin-based sheet contracts, the sagging of the sheet is suppressed. For this reason, it is possible to prevent the flame from spreading in a form that wraps around from the bottom along the sagging portion, thereby suppressing the spread of the combustion and increasing the flame retardancy.

  The conventional polyolefin-based sheet for vehicle interior materials needs to contain a halogen-based flame retardant or a phosphorus-based flame retardant in order to pass the vehicle flame retardant standard. By adopting the above-described configuration, the system sheet has flame retardancy that passes vehicle flame retardant standards without blending such a flame retardant with a large environmental load.

  The material of the polyolefin-based sheet of the base material in the polyolefin-based sheet for vehicle interior materials of the present invention is basically not particularly limited as long as it is a polyolefin-based material. For example, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene , High density polyethylene, homopolypropylene, random polypropylene, block polypropylene, syndiotactic polypropylene, ethylene-propylene copolymer, EPDM, dynamically crosslinked thermoplastic olefin elastomer, and the like. From the viewpoint of flame retardancy, in particular, from the viewpoint of drip generation during combustion, it is preferable to use a base material that does not contain process oil. Moreover, you may mix | blend flame retardants, such as a nitrogen-containing type flame retardant, with a base material. The surface of the polyolefin-based sheet as a base material may be provided with a pattern such as a texture that has been conventionally employed.

  A polyolefin sheet having a property of shrinking when heated is laminated on the back surface of the polyolefin sheet of the base material. The polyolefin-based sheet is preferably one having a large heat shrinkage rate, and preferably has no directionality in heat shrinkage. As an example of the polyolefin sheet-like material, a uniaxially stretched polyolefin split yarn nonwoven fabric may be mentioned. The split yarn is preferably a flat yarn that is uniaxially stretched in the machine direction after chopping a polyethylene film or a polypropylene film into 3 to 10 mm. As the draw ratio at this time increases, the thermal shrinkage rate increases. A nonwoven fabric in which the flat yarns are arranged at intervals in the vertical direction and the flat yarns are arranged at intervals in the horizontal direction and thermally bonded to form a flat woven fabric is preferably used. Further, it is also possible to use a nonwoven fabric in which flat yarns are arranged at intervals in the longitudinal direction, flat yarns are arranged at intervals in both oblique directions, and are thermally bonded together. These non-woven fabrics are commercially available, for example, from Sekisui Chemical Co., Ltd. under the Sof brand name and from Nippon Steel Plast Co., Ltd. under the Warif brand name.

  Also, use a non-woven fabric that is uniaxially stretched in the longitudinal direction of a polyethylene film or polypropylene film, then split-processed into fibers (spreading treatment), and the split film is expanded and stacked in the longitudinal and lateral directions and thermally bonded. You can also. Moreover, what is called a shrink film which biaxially stretched the polyethylene film and the polypropylene film can be used as said polyolefin-type sheet-like material. These polyolefin-based sheet materials having the property of shrinking when heated are preferably those having a thermal shrinkage rate (longitudinal and transverse directions) of 0.5% or less when left in an atmosphere of 80 ° C. for 1 hour. If the one having a thermal shrinkage rate exceeding 0.5% is used, there is a concern that wrinkles may occur in the product. In special cases, such as a sheet used for a sun visor or a pillar, when it is only necessary to suppress the burning rate in only one direction in the longitudinal direction, a non-woven fabric that thermally shrinks in only one direction or a shrink film stretched only in one direction May be used. Moreover, when using a shrink film, it is preferable to mix | blend a nitrogen-containing flame retardant with the polyolefin-type sheet | seat of a base material since heat shrinkability is inferior and the sagging suppression effect of a sheet | seat is not enough, and a flame retarding effect is somewhat inferior. Moreover, the stretched film used as the raw material of the polyolefin-type sheet-like material which has a property shrink | contracted at the time of heating has a preferable thing (thickness after extending | stretching) 10-110 micrometers.

  In order to laminate the polyolefin sheet material on the back surface of the polyolefin sheet of the substrate, the polyolefin sheet material is stacked on the back surface of the polyolefin sheet of the substrate and heated and pressed. The polyolefin-based sheet for vehicle interior materials of the present invention is used for interior materials of vehicles such as automobiles, for example, sun visors, pillars, ceilings and the like.

  90 parts by mass of reactor polypropylene (Q100F manufactured by Sun Allomer Co., Ltd.), 5 parts by mass of metallocene linear low density polyethylene (FV201 manufactured by Sumitomo Chemical Co., Ltd.), 5 parts by mass of random polypropylene (S131 manufactured by Sumitomo Chemical Co., Ltd.), fatty acid metal salt (lubricant) 0 .3 parts by mass, 0.2 parts by mass of a phosphoric acid partial ester metal salt (lubricant), 0.2 parts by mass of a hindered amine light stabilizer, 0.1 parts by mass of a triazole ultraviolet absorber and 5 parts by mass of calcium carbonate A sheet having a thickness of 0.3 mm was formed by a calender by a conventional method, and the surface was embossed. A non-woven fabric (Sekisui Chemical Co., Ltd., Sofsui Chemical Co., Ltd., thickness 95 μm), which is formed by superposing and laying uniaxially stretched flat yarns of polyethylene in the longitudinal direction and in both oblique directions, is laminated on the back surface of this sheet, and heated under pressure. Lamination was performed to obtain a polyolefin-based sheet for vehicle interior materials according to the present invention. When this sheet was used to produce a sun visor by heat sealing, a good quality sun visor free from wrinkles and other problems was obtained. Moreover, when the flame retardance test and the drip test were conducted, the results shown in Table 1 were obtained. The flame retardant test was conducted according to JIS D1201 (1998) at the maximum value (mm / min) of the combustion rate in the longitudinal direction n = 10. In the drip test, a sample having a length of 30 cm and a width of 5 cm was prepared, and the drip (melting and dropping of fire type) was visually evaluated by hanging vertically and blowing with a lighter.

  90 parts by mass of reactor polypropylene (Q100F manufactured by Sun Allomer Co., Ltd.), 5 parts by mass of metallocene linear low density polyethylene (FV201 manufactured by Sumitomo Chemical Co., Ltd.), 5 parts by mass of random polypropylene (S131 manufactured by Sumitomo Chemical Co., Ltd.), fatty acid metal salt (lubricant) 0 .3 parts by weight, 0.2 parts by weight of a phosphoric acid partial ester metal salt (lubricant), 0.2 parts by weight of a hindered amine light stabilizer, 0.1 parts by weight of a triazole ultraviolet absorber, 5 parts by weight of calcium carbonate, hydrazo 15 parts by mass of dicarbonamide (flame retardant) and 10 parts by mass of melamine cyanurate (flame retardant) were blended, and a 0.3 mm thick sheet was formed by a conventional method using a calender and embossed on the surface. A biaxially stretched shrink film (Randy Five NP-300 manufactured by Okura Kogyo Co., Ltd., thickness 25 μm) is stacked on the back surface of this sheet, and heated and laminated to obtain a polyolefin-based sheet for vehicle interior materials according to the present invention. It was. The flame retardant test and drip test results of this sheet are shown in Table 1.

  A uniaxially stretched shrink film (Polyshrink TR manufactured by Sekisui Chemical Co., Ltd., thickness 40 μm) is stacked on the back surface of the sheet obtained by calendering and embossing the surface of Example 2, and laminated by pressurizing and heating. Thus, a polyolefin-based sheet for vehicle interior materials according to the present invention was obtained. The flame retardant test and drip test results of this sheet are shown in Table 1.

  90 parts by mass of partially crosslinked blend type polyolefin-based thermoplastic elastomer (containing 32% by mass of paraffinic process oil), 5 parts by mass of metallocene linear low density polyethylene (FV201 manufactured by Sumitomo Chemical Co., Ltd.), random polypropylene (S131 manufactured by Sumitomo Chemical Co., Ltd.) 5 parts by weight, fatty acid metal salt (lubricant) 0.3 part by weight, phosphoric acid partial ester metal salt (lubricant) 0.2 part by weight, hindered amine light stabilizer 0.2 part by weight, triazole ultraviolet absorber 0.1 Part by mass and 5 parts by mass of calcium carbonate were blended, a sheet having a thickness of 0.3 mm was formed in a conventional manner by a calendar, and the surface was embossed. A non-woven fabric (Sofsui Chemical Co., Ltd. Sof GX55) heat-bonded by superimposing polyethylene uniaxially stretched flat yarns in the longitudinal direction and in both diagonal directions is stacked on the back surface of this sheet, and laminated by heating under pressure. A polyolefin-based sheet for vehicle interior materials of the invention was obtained. The flame retardant test and drip test results of this sheet are shown in Table 1.

Comparative Example 1

  The formulation of Example 2 was calendered to produce a 0.3 mm thick sheet and embossed on the surface. This sheet was directly subjected to a flame retardant test and a drip test. The results are shown in Table 1.

As can be seen from Table 1, in the flame retardant test, the results of self-extinguishing were obtained for all the polyolefin-based sheets for vehicle interior materials of the examples of the present invention. On the other hand, the comparative example 1 which did not laminate the polyolefin-type sheet-like material which has a property shrink | contracted at the time of heating was 156.2 mm / min and a big value. In addition, in the drip test, Examples 1 to 3 were small, but Example 4 using a polyolefin-based elastomer compounded with process oil as a material for the polyolefin-based sheet of the base material was large. Moreover, the comparative example 1 which did not laminate the polyolefin-type sheet-like material which has the property shrink | contracted at the time of a heating was also large.

Claims (3)

  A polyolefin-based sheet for vehicle interior materials, which is obtained by laminating a polyolefin-based sheet-like material having a property of shrinking when heated on the back surface of a polyolefin-based sheet as a base material.   The polyolefin sheet for vehicle interior materials according to claim 1, wherein the polyolefin sheet is a uniaxially stretched nonwoven fabric of split polyolefin yarn. The polyolefin sheet for vehicle interior materials according to claim 1, wherein the polyolefin sheet is a biaxially stretched polyolefin film.