JP2001071310A - Sheet member for automotive interior trim part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet member which is of high rigidity, highly heat- resistant and lightweight almost without physical property deterioration even when recycled and leaves almost no residues after incineration by making the sheet member of a mixture of a polyolefin thermoplastic resin and finely divided bamboo. SOLUTION: A polyolefin thermoplastic resin such as a polyethylene, a polypropylene or a polypropylene-polyethylene copolymer and yarious kinds of finely divided bamboo such as Phyl-lostachys pubescens and long jointed bamboo are mixed as a material. The content of the finely divided bamboo is at least not less than 20 wt.% and not more than 80 wt.% to the total weight of the material. Both are stirred and mixed using a Henschel mixer or the like, and if necessary, with an antioxidant, a coloring agent or the like, and the mixture is extrusion-molded or calender-processed into the sheet member. This sheet member is of high rigidity and low molding shrinkage factor and is highly heat-resistant and besides is best suited as a lining or a reinforcing material for an automotive interior trim part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a seat member for an automobile interior part. More specifically, instrument panels, sunshades, sunroof shades,
The present invention relates to a sheet member for lining or reinforcing a ceiling material or the like.

[0002]

2. Description of the Related Art As a member for the interior of an automobile, a glass fiber reinforced thermoplastic resin (for example, Japanese Unexamined Patent Publication No.
-67622) or a thermoplastic resin added with wood flour (for example, JP-A-61-222842). recent years,
Engineering plastic foams have been proposed. However, in the former, the treatment of the material is beginning to be regarded as a problem, for example, glass fibers are fragmented and the reinforcing effect is reduced during material recycling, and a large amount of glass fibers remains as incineration residues when incinerated. Also, with wood flour addition,
Although incineration is easy, the effect of improving physical properties such as rigidity is small, and for example, a sheet having a thickness of about 3 mm is required (Japanese Patent Application Laid-Open No. 61-222842). The use of engineering plastics is expensive.
On the other hand, it is known that bamboo powder is added to a thermoplastic resin as a material that can be easily incinerated, and the rigidity is improved (for example, JP-A-8-134361).

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet for automobile interior parts which has high rigidity and heat resistance, is lightweight, has little deterioration in physical properties even when recycled, and hardly remains even when incinerated. It is to provide a member.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that the composition comprising finely divided bamboo and a polyolefin-based thermoplastic resin has a high rigidity and a low viscosity. The heat resistance was remarkably improved, and it was found that a sheet member comprising the composition satisfies the above-mentioned problems and was suitable as a sheet member for an automobile interior part, and thus the present invention was achieved. That is, the present invention is a sheet member for an automobile interior part, comprising a polyolefin-based thermoplastic resin and finely divided bamboo.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, examples of the polyolefin-based thermoplastic resin include, for example, polyethylene, polypropylene, propylene-ethylene copolymers, those modified with maleic anhydride, and propylene or ethylene. A low-molecular-weight product of the above resin such as a copolymer of a monomer copolymerizable therewith, polyethylene wax, and polypropylene wax;
Elastomers such as propylene rubber-like copolymer and polybutene are also included. However, it is not limited to these. Also, a mixture of two or more of these resins may be used.

The miniaturized bamboo used in the present invention is obtained by miniaturizing various types of bamboo such as Moso bamboo and Shin bamboo. The average particle size of the refined bamboo is preferably in the range of 5 to 500 μm. When the particle size is smaller than 5 μm, the bulk density is small, so that the particles are easily scattered and difficult to handle, and are easily classified at the time of mixing with a polyolefin-based thermoplastic resin, which is not preferable. On the other hand, when the thickness is larger than 500 μm, the surface condition of the molded article is deteriorated, which is not preferable because it causes inconvenience depending on the purpose of manufacturing the molded article.

[0007] The method for producing the above-mentioned fine bamboo is not particularly limited, but bamboo itself or bamboo scraps generated during the production of bamboo products can be removed using a stone mill, ball mill, hammer mill, or the like.
It is obtained by crushing with an impact crusher or the like. The material may be once coarsely pulverized and then pulverized again to make it finer. Further, the crushed bamboo may be classified by using a sieve or a classifier and used. The content of the finely divided bamboo in the present invention is at least 20% by weight or more and 80% by weight or less, preferably 30% by weight or more and 70% by weight of the total weight of the resin and the finely divided bamboo.
It is as follows. If it is less than 20% by weight, rigidity and heat resistance are not sufficient, which is not preferable. If it exceeds 80% by weight, the moldability is inferior.

The polyolefin-based thermoplastic resin and the finely divided bamboo are mixed with an antioxidant, a coloring agent, and the like, if necessary, using a Hensyl mixer or the like.
The mixture may be heated and melt-extruded with an extruder to form pellets, or may be melt-granulated at the time of mixing with a Hensyl mixer or the like. Further, the two may be melt-kneaded by a heated roll, cut into a sheet, and granulated. The product may be obtained by being directly supplied to an extruder, a calender roll, or the like without being formed into a pellet shape. The use of a powdery polyolefin-based thermoplastic resin is preferable because the dispersibility of the finely divided bamboo is improved.

As a method for producing the sheet member of the present invention, general extrusion molding and calendering can be employed. In the case of calendering, even if the resin and the finely divided bamboo are melt-pelletized and granulated, or the mixture of pelletized or powdery resin and the finely divided bamboo is directly poured into the mixing roll of the calendar facility, Alternatively, the mixture may be melted by an extruder and charged into a mixing roll or a calender roll. A thick sheet can also be obtained by stacking a plurality of thin sheets obtained by calendering and hot pressing.

The polyolefin-based thermoplastic resin used in the present invention or a mixture of the resin and finely divided bamboo may contain, in addition to an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a coloring dye, a pigment, etc. Or other resin or organic or inorganic filler. The sheet member of the present invention has high rigidity and heat resistance, has a small molding shrinkage, has extremely little warpage, and can be vacuum-formed or air-pressed, and has antibacterial properties. It is suitable as a backing or reinforcing material for automobile interior parts used for ceiling trims, sunshades, door trims, trunks and the like.

Although fine bamboo exhibits the effect of strengthening the resin similarly to glass fiber, the fine bamboo has flexibility in itself unlike glass fiber. Even when the composition is passed through an extruder again, it is hard to be further divided, and the physical properties hardly change. Moreover, the sheet member of the present invention hardly remains even after incineration. The method of manufacturing an automobile interior part using the sheet member of the present invention is not particularly limited, but a skin material or the like is bonded to the sheet member of the present invention, and the sheet member is directly used, or hot pressed or vacuum formed or compressed air as needed. Manufacture automotive interior parts by molding. The lamination of the skin material or the like may be performed by laminating the manufactured sheet member by post-processing, or may be performed by directly laminating the skin material or the like at the time of extrusion molding or calendering the sheet member.

[0012]

The present invention will be described below with reference to examples. Example 1 Polypropylene resin (J3H, Grand Polymer Co., Ltd.)
50% by weight), 50% by weight of finely divided bamboo having an average particle size of 150 μm obtained by crushing Moso bamboo by a ball mill and then sieving, and a total of 100% of polypropylene resin and the finely divided bamboo. 0.5 parts by weight of Irganox 1076 (manufactured by Nihon Geigy Co., Ltd.) as an antioxidant was sufficiently mixed with the parts by weight with a Hensyl mixer, and then a vent having an L / D = 28 and a cylinder inner diameter of 50 mm was used. The mixture was melt-pelletized at a set temperature of 200 ° C. by using an extruder equipped with a heat exchanger. Using the obtained pellets, test pieces were formed by injection molding, and the flexural modulus, heat deformation temperature, and antibacterial property were evaluated. Table 1 and Table 2 show the measurement results.
Shown in The pellets were melted at a set temperature of 180 ° C. using extrusion molding with L / D = 30, cylinder inner diameter of 65 mm, thickness of about 0.5 mm and width of about 130.
A 0 mm sheet was formed. This sheet has a length of 2500
mm, the skin material was bonded, and a ceiling material was formed by hot pressing. The sheet was able to hold a sufficient shape as a backing material. In addition, assuming recycling of the obtained pellets, they were again passed through an extruder, and test specimens were formed by injection molding. The flexural modulus and heat deformation temperature were measured. Has hardly changed. Furthermore, when the obtained sheet was incinerated,
Little residue was left. The evaluation of antibacterial properties was performed on Escherichia coli, Staphylococcus aureus and Escherichia coli O-157. The antibacterial property was evaluated per 25 cm ² of the test piece, the surface thereof was sterilized with ethanol, and then a suspension of bacteria prepared with a phosphate buffer solution (initial bacterial count: E. coli 1.7 × 10 ⁶ , Staphylococcus aureus 1.4
× 10 ³ , E. coli O-157 7.0 × 10 ⁵ ).
5 ml was dropped, and a sterilized polyethylene film was put thereon, and stored at 35 ° C. for 24 hours. Then, the plate surface was washed out with a sterilized phosphate buffer, and the number of surviving bacteria in the washed out solution was counted. The number of viable cells was measured by a pour plate method using an agar culture medium. The measurement was performed with n = 3, and the average value was obtained. In addition, the measurement of the flexural modulus and the heat distortion temperature was performed according to JIS K-7203 and JIS K-7203, respectively.
According to SK-7207.

Comparative Example 1 In Example 1, pellets were formed in the same manner as in Example 1 except that fine bamboo was not added, and a test piece was molded using the obtained pellets. went. Tables 1 and 2 show the measurement results.

Example 2 Polypropylene resin (J3H, Grand Polymer Co., Ltd.)
35% by weight), 5% by weight of polyolefin wax (High Wax HW2203A, manufactured by Mitsui Chemicals, Inc.), 5% by weight of low-density polyethylene (Ulto Zex 15100C, manufactured by Mitsui Chemicals, Inc.) and the fineness used in Example 1. 0.5% by weight of Irganox 1076 (manufactured by Nippon Geigy) as an antioxidant to 55% by weight of the obtained bamboo and 100 parts by weight of the polypropylene resin, polyolefin wax, high-density polyethylene and the finely divided bamboo in total. Was sufficiently mixed with a Hensyl mixer, and then supplied to a mixing roll at a set temperature of 160 ° C. Using an L-type calender roll, the first mixing roll 160 ° C.
2nd mixing roll 160 ° C, calender roll 17
At 0 ° C., a sheet having a width of about 1300 mm and a thickness of about 0.5 mm was obtained. The appearance of the sheet was good, and no visual abnormality was observed. Using this sheet, a ceiling material was formed in the same manner as in Example 1. However, as in Example 1, the ceiling material could be sufficiently retained as a backing material. Further, when this sheet was incinerated, almost no residue was left. Separately, a resin and finely divided bamboo were thoroughly mixed with a Hensyl mixer, and then pelletized in the same manner as in Example 1 to prepare a test piece, and the physical properties and antibacterial properties were evaluated. The results are shown in Tables 1 and 2. Furthermore, the pellets obtained assuming recycling were passed through an extruder again to form test pieces by injection molding in the same manner as in Example 1, and the flexural modulus and heat distortion temperature were measured. Although it turned brown, the physical properties hardly changed.

Comparative Example 2 In Example 2, a test piece was formed by pelletizing in the same manner as in Example 2 except that fine bamboo was not added, and physical properties and antibacterial properties were evaluated. Table 1 and Table 2 show the measurement results.
Shown in

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

The sheet member according to the present invention contains finely divided bamboo. Bamboo has been used as a container for cooking chopsticks, tableware and bamboo rice, as well as a container for bamboo liquor and cappo liquor since ancient times. Also, bamboo grows in three to five years, unlike trees, so it can be obtained without damaging the environment and is abundant as a resource.
In addition, finely divided bamboo can be used as a material in consideration of the global environment because it can utilize wastes that are discarded when manufacturing chopsticks, bamboo baskets, and the like. Furthermore, since the sheet member of the present invention has good physical properties such as rigidity and heat resistance and can be formed by vacuum forming or air pressure forming, it can be formed by laminating with a skin material, for example, for instrument panels of automobiles, ceilings, trunk rooms, etc. It can be suitably used for automobile interior parts such as interior parts and sunshades. Furthermore, bamboo has antibacterial properties, and the sheet member of the present invention including finely divided bamboo is also preferable because it has antibacterial properties.

Continued on the front page F term (reference) 2B260 AA01 AA02 BA07 BA15 BA18 CB02 CD10 DA01 DA18 DD03 EA05 EA11 EA13 EB02 EB06 EB12 EB19 EB21 EC18 3D023 BA01 BB02 BC01 BD01 BE04

Claims (3)

[Claims] 1. A sheet member for an automobile interior part, comprising a polyolefin-based thermoplastic resin and finely divided bamboo. 2. The fine bamboo content is 20% by weight.
The sheet member for an automobile interior part according to claim 1, which is at least 80% by weight or less. 3. The sheet member for an automobile interior part according to claim 1, wherein the sheet member is a calendered sheet.