JP2019065139A - Exterior part for vehicle - Google Patents

Abstract

To provide an exterior part for vehicle which has a resin part that enables cellulose to be simply and uniformly dispersed in a resin having high hydrophobicity, can improve a mechanical strength of a molding material formed using the obtained resin composition, and is formed of a thermoplastic resin composition.SOLUTION: An exterior part for vehicle is a thermoplastic resin composition which contains 5-70 pts.mass of cellulose with respect to 100 pts.mass of a thermoplastic synthetic resin, and contains an organic peroxide, where a tensile strength measured according to JIS K 7161 of the resin formed of the thermoplastic resin composition is 40 MPa or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to an exterior component for a vehicle, and more particularly to an exterior component for a vehicle molded with a thermoplastic resin composition containing cellulose.
More specifically, a vehicle exterior component comprising a resin portion formed of a cellulose-reinforced thermoplastic resin composition comprising a thermoplastic resin and a cellulose toughening agent having high mechanical strength, and a cellulose-reinforced thermoplastic resin composition The exterior part for vehicles provided with the resin part formed with the thermoplastic resin composition for obtaining.

  Conventionally, in vehicles including automobiles, weight reduction for the purpose of improving fuel consumption has been considered from the viewpoint of saving resources such as fossil fuel. In addition, research is being actively carried out to resinify the exterior panel in order to improve not only the weight but also the safety and the quality. In such an exterior panel, since high mechanical strength and impact resistance are required, glass fiber, aramid fiber, carbon fiber, etc. are developed as a resin reinforcing material.

  However, the glass fiber alone has poor surface properties, and can not be used as it is as a vehicle exterior material. Conversely, if it is intended to use only a resin, the rigidity of the exterior material is insufficient. As a result, since a composite material in which different materials are combined is used, a difference in the thermal expansion coefficient of each material may cause problems in bonding and appearance. Moreover, in the vehicle, it is also required to introduce a decorative form on the surface for the purpose of decoration and design. In particular, in recent years, there is a strong demand for reinforcements with raw materials that reduce environmental load and do not worry about resource depletion.

  Until now, the inventors conducted various studies on exterior parts as vehicle materials, and as a result, it is important to develop a composite material capable of making the reinforcing material as a filler well dispersed in resin as a base material. It turned out that there is. In addition, in vehicle exterior parts such as back doors, if the outer panel (for example, made of steel) and the inner panel (for example, made of resin) are different materials, problems such as penetration may occur due to the difference in rigidity. It was found that it is important to minimize this difference in rigidity. Furthermore, in order to simplify painting of exterior parts, it turned out that it is also important that coloring of a material is easy.

  In order to meet the above-mentioned requirements, cellulose fibers are considered promising. Cellulose fibers are widely known as reinforcing materials such as resins because they have excellent properties such as light weight, high strength, high elastic modulus, and low linear thermal expansion. However, since cellulose fibers have very high hydrophilicity, they have poor affinity for highly hydrophobic resins such as polypropylene and polyethylene, and they should be uniformly mixed only by mechanical kneading with a twin-screw extrusion machine or the like. I can not For this reason, the mechanical physical properties of the resulting composite material were not always satisfactory and inadequate. Generally, when using a highly hydrophobic thermoplastic resin such as polyethylene or polypropylene when producing a molding material containing cellulose fibers, the dispersibility of the cellulose fibers is poor, and it is very difficult to obtain additional mechanical strength. It is.

  To solve such problems, in order to improve the dispersibility of cellulose in resin, a compatibilizer is used. Alternatively, attempts have been made to modify the cellulose or resin with a modifier or the like to improve the dispersibility of cellulose in the resin (see, for example, Patent Documents 1 to 4).

  For example, Patent Documents 1 and 2 propose using unsaturated dicarboxylic acid and / or an anhydride thereof as a compatibilizer or an interface reinforcing agent in a resin composition comprising a cellulosic material and a polyolefin. Moreover, in patent document 3, using a polybasic acid anhydride as a hydrophobic modifier for a part of the hydroxyl group of microfibrillated cellulose and using the obtained hydrophobic modified cellulose fiber as a reinforcement material of resin is proposed. . Furthermore, Patent Document 4 proposes to improve the dispersibility of cellulose by using polyethylene in which a monomer having a carboxy group having an affinity for a hydroxyl group present in cellulose is grafted in a specific method. ing.

  Although the reinforcement effect of a cellulose is acquired and the mechanical strength of a molded object improves even if it uses any of the said methods, the improvement of mechanical strength further was desired.

Japanese Patent Application Laid-Open No. 62-39642 U.S. Patent Application Publication No. 2008/0146701 JP, 2012-214563, A Patent No. 347961

In view of the problems with vehicle exterior parts using conventional materials, the present invention can be easily and uniformly dispersed in a highly hydrophobic resin, and is formed using the resin composition obtained. It is an object of the present invention to provide a vehicle exterior component including a resin portion formed of a thermoplastic resin composition capable of improving the mechanical strength of the molding material.
Another object of the present invention is to provide a vehicle exterior component comprising a resin portion formed of a cellulose reinforced thermoplastic resin composition obtained by using the thermoplastic resin composition.

  As a result of intensive studies to solve the above problems, the present inventors improve the dispersibility of cellulose fiber by incorporating cellulose fiber, thermoplastic synthetic resin and organic peroxide in the resin composition. It has been found that the thermoplastic resin composition obtained is obtained, and the thermoplastic resin composition is heated and kneaded to react the components, whereby a cellulose reinforced thermoplastic resin composition can be obtained. As a result, the mechanical strength of the resin member obtained by using the thermoplastic resin composition and the cellulose reinforced thermoplastic resin composition is greatly improved, and thereby, the resin portion formed of the thermoplastic resin composition is provided. It has been found that a vehicle exterior component comprising a vehicle exterior component and a resin portion formed using a cellulose reinforced thermoplastic resin composition can be obtained.

That is, the gist configuration of the present invention is as follows.
[1] A thermoplastic resin composition containing 5 to 70 parts by mass of cellulose with respect to 100 parts by mass of a thermoplastic synthetic resin and containing an organic peroxide, which is a resin comprising the thermoplastic resin composition The exterior component for vehicles provided with the resin part formed with the thermoplastic resin composition whose tensile strength measured based on JISK7161 is 40 Mpa or more.
[2] The vehicle exterior part according to the above [1], wherein the thermoplastic synthetic resin comprises a graft modified polyolefin resin of an unsaturated carboxylic acid or an anhydride thereof.
[3] The exterior part for a vehicle according to the above [1] or [2], wherein the one-minute half-life temperature of the organic peroxide is 130 to 190 ° C.
[4] The above-mentioned [1], wherein the organic peroxide is at least one organic peroxide selected from dialkyl peroxides, peroxyketals, diacyl peroxides, alkyl peroxy esters and monoperoxy carbonates. The exterior part for vehicles in any one of [3].
[5] In any one of the above [1] to [4], the content of the organic peroxide is 0.01 to 0.30 parts by mass with respect to 100 parts by mass of the thermoplastic synthetic resin Vehicle exterior parts described.
[6] The thermoplastic synthetic resin contains a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and the graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride is a maleic anhydride-modified polyolefin resin The exterior part for vehicles in any one of said [1]-[5].
[7] The above thermoplastic synthetic resin is a mixed resin of a graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride and a polyolefin resin which is not modified with unsaturated carboxylic acid or its anhydride The exterior part for vehicles in any one of-[6].
[8] The vehicle exterior part according to any one of the above [1] to [7], wherein the cellulose is a fibrous cellulose derived from a plant.
[9] A cellulose reinforced thermoplastic resin composition comprising an ester bond composite resin of a cellulose hydroxyl group and a cross-linked polyolefin resin having a carboxy group, wherein the content of the cellulose component in the ester bond composite resin is And a cellulose reinforced thermoplastic resin composition having a tensile strength of 40 MPa or more which is 9.0 to 42% by mass, and which is measured according to JIS K 7161 of the cellulose reinforced thermoplastic resin composition. Exterior parts for vehicles provided with a resin part.
[10] The polyolefin resin of the crosslinked structure having a carboxy group is a polyolefin resin which is not modified with carbon atoms of the main chain of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride and unsaturated carboxylic acid or its anhydride. The exterior part for vehicles as described in said [9] which is the polyolefin resin of the crosslinked structure which the carbon atom of the principal chain of these is couple | bonded in two or more places.
[11] The polyolefin resin before modification of the graft modified polyolefin resin of the unsaturated carboxylic acid or the anhydride thereof and the polyolefin resin not modified with the unsaturated carboxylic acid or the anhydride thereof are different polyolefin resins The exterior part for vehicles as described in said [10].
[12] The vehicle exterior part according to any one of the above [9] to [11], wherein the cellulose is a fibrous cellulose derived from a plant.
[13] The exterior part for a vehicle according to any one of the above [1] to [12], which is a fender, a back door or a spoiler.
[14] The back door has an inner panel and an outer panel,
The exterior component for a vehicle according to the above [13], wherein one or both of the inner panel and the outer panel are formed of the thermoplastic resin composition.

According to the present invention, a thermoplastic resin composition containing cellulose in a uniformly dispersed state and a cellulose reinforced thermoplastic resin composition obtained by heating and kneading the thermoplastic resin composition are used to machine It is possible to provide an exterior part for a vehicle provided with a resin portion with improved target strength.
Further, in the present invention, since a cellulose reinforced thermoplastic resin composition comprising a thermoplastic resin and a cellulose reinforcing agent is used, weight reduction and high strength are achieved, as well as recyclability, surface smoothness, and adhesion performance. It becomes possible to realize an exterior part for a vehicle provided with an excellent resin portion.
In addition, as the vehicle exterior parts, particularly, the fender, the back door or the spoiler is formed of the thermoplastic resin composition or the cellulose reinforced thermoplastic resin composition, thereby improving the safety and quality of the vehicle. The fuel efficiency of the vehicle can be improved, and resources such as fossil fuel can be saved. Moreover, while thinning of the exterior parts for vehicles can be realized, reduction of incineration ash at the time of disposal, etc. can be expected.

Further, according to the present invention, it is possible to achieve both weight reduction and rigidity, has a low coefficient of linear thermal expansion at room temperature, is excellent in fluidity at high temperature, and is further excellent in appearance and coloring. Parts can be provided.
In particular, since the thermoplastic resin composition or the cellulose reinforced thermoplastic resin composition has a small linear thermal expansion coefficient and a small anisotropy, it can be used as a stable composite material. Therefore, in the case of a vehicle exterior part such as a back door having an inner panel and an outer panel, both the inner panel and the outer panel can be easily manufactured with the same material, and occurrence of penetration due to a difference in rigidity can be prevented. Can. In addition, it becomes possible to integrally mold both the inner panel and the outer panel with the above thermoplastic resin composition or the cellulose reinforced thermoplastic resin composition, thereby reducing the number of parts of the vehicle and reducing the number of assembling steps. it can.
Moreover, the exterior part for vehicles formed using the said thermoplastic resin composition is smooth, the touch is good, the coloring property to resin is also excellent, and simplification of coating can be implement | achieved.

It is a schematic diagram showing an example of vehicles provided with the exterior component for vehicles concerning an embodiment of the present invention.

  An exterior part for a vehicle according to an embodiment of the present invention is a thermoplastic resin composition containing 5 to 70 parts by mass of cellulose and 100 parts by mass of a thermoplastic synthetic resin, and containing an organic peroxide, It has a resin portion formed of a thermoplastic resin composition having a tensile strength of 40 MPa or more measured according to JIS K 7161 of a resin comprising the thermoplastic resin composition.

The cellulose-reinforced thermoplastic resin composition used in the present invention is obtained by heating and kneading the above-mentioned thermoplastic resin composition to cause the components to react.
Therefore, in another embodiment of the present invention, the resin part of the exterior part for a vehicle or the exterior part for a vehicle is an ester bond composite resin (composite) of a cross-linked polyolefin resin having a hydroxyl group and a carboxy group of cellulose. It is a cellulose reinforced thermoplastic resin composition which contains, The content of the cellulose component which occupies in this ester bond composite resin is 9.0-42 mass%, the resin which consists of the above-mentioned cellulose reinforced thermoplastic resin composition The tensile strength measured based on JISK7161 is formed with the cellulose reinforcement thermoplastic resin composition which is 40 Mpa or more.

<< tensile strength >>
In the present invention, the tensile strength of the resin comprising the thermoplastic resin composition used is the characteristic or physical property of the resin contained in this thermoplastic resin composition, and the thermoplastic resin composition is heated and kneaded to obtain the components. The cellulose reinforced thermoplastic resin composition obtained by making it react is processed and evaluated the test piece of the form adapted to the tensile strength evaluation based on the test piece type 2 of JISK7127.
On the other hand, the cellulose-reinforced thermoplastic resin composition has already been reacted with the components, and is only processed into a test piece of a form suitable for tensile strength evaluation in accordance with JIS K7127, Test specimen type 2.

  In order to use the organic peroxide as the radical polymerization initiator to react the components contained in the thermoplastic resin composition, generally, the organic peroxide is thermally decomposed to a temperature at which the radical reaction starts Specifically, it may be 1 minute half-life temperature or more of organic peroxide (preferably, a temperature higher by 20 ° C. than 1 minute half-life temperature), and heat kneading may be performed with a general twin-screw extruder, Cellulose-reinforced thermoplastic resin compositions can be made as pellets.

  Although the conditions of heat-kneading are described below, this does not specify the manufacturing method of the cellulose reinforced thermoplastic resin composition used by this invention, and measures the tensile strength which is a parameter as a physical property and a characteristic. It is a condition to

The kneading temperature of the thermoplastic resin composition is equal to or higher than the decomposition temperature of the organic peroxide present in the composition, and preferably, the temperature is 20 ° C. higher than the 1 minute half-life temperature of the organic peroxide used. . The stirring is not particularly limited, but for example, a screw diameter of 15 mm, L / D = 45, and a rotational speed of 100 rpm are sufficient.
This heating and kneading may be a model heating and kneading machine instead of the heating and kneading machine used for production.

  When heat-kneading with a twin-screw extruder (for example, KZW15TW-45MG-NH, manufactured by Technobel Co., Ltd.), a twin screw with a screw diameter of 15 mm and L / D = 45 is provided by a feeder which controls each component by supplied mass per time. The parelle temperature in the kneading zone is set 20 ° C. higher than the half-life temperature of the organic peroxide at 1 minute, and the screw rotational speed is heated and kneaded at 100 rpm.

  The tensile strength is measured by subjecting a cellulose-reinforced thermoplastic resin composition obtained by heating and kneading a thermoplastic resin composition to react the components, in accordance with JIS K 7127, test specimen type 2, tensile test A piece is prepared and measured in accordance with JIS K 7161.

In addition, when heat-kneading with a twin-screw extruder, the thermoplastic resin composition pellet obtained by heat-kneading with a twin-screw extruder is dried at 80 ° C. for 24 hours, and an injection molding machine [eg, manufactured by FANUC Co., Ltd.] The above test piece is manufactured by robot shot [alpha] -30C].
The tensile strength is measured with a tensile tester [for example, Instron's Instron testing machine model 5567] under conditions of a distance between test wires of 25 mm and a test speed of 50 mm / min.

The tensile strength is preferably as high as possible, and is 40 MPa or more in the present invention, but 45 MPa or more is more preferable, 50 MPa or more is more preferable, and 55 MPa or more is particularly preferable.
The upper limit of the tensile strength is practically 100 MPa.

  The tensile strength can be adjusted by the type and content of the components contained in each of the above resin compositions and the cellulose reinforced thermoplastic resin, but in particular, it is effective to adjust the compounding amount of the organic peroxide, It is more effective to adjust by combining the blending amount of the organic peroxide and the maleic anhydride modified polyolefin in a well-balanced manner.

  The thermoplastic resin composition will be described below in order.

<< Thermoplastic resin composition >>
The thermoplastic resin composition used in the present invention contains at least a thermoplastic synthetic resin, cellulose and an organic peroxide. The thermoplastic synthetic resin may contain a graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride.
First, the thermoplastic synthetic resin will be described.

<Thermoplastic synthetic resin>
In the present invention, one of the thermoplastic synthetic resins may be a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and the thermoplastic synthetic resin is a graft of unsaturated carboxylic acid or its anhydride. Only modified polyolefin resin may be used.

[Base resin]
The base resin is a resin component having the largest content among thermoplastic synthetic resins other than the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride contained in the thermoplastic resin composition, and unsaturated carboxylic acid Alternatively, it may be contained in the same mass or more as the graft modified polyolefin resin of the anhydride thereof.
However, since cellulose is not a synthetic resin, it is not included in the thermoplastic synthetic resin.

The base resin used in the present invention is not particularly limited, and any synthetic resin generally used as a thermoplastic synthetic resin may be used.
Examples of the base resin include polyolefin resin, polyester resin, polycarbonate resin, polyamide resin, polyimide resin, polyurethane resin, polyphenylene sulfide resin, polyphenylene oxide resin, cellulose acylate resin, phenoxy resin and the like.
Among these, in the present invention, a polyolefin resin is preferred.

The polyolefin resin is a polyolefin resin formed by polymerizing at least one olefin, and may be a homopolymer or a copolymer.
As such an olefin, for example, ethylene, propylene, isobutylene, α-olefin having 4 to 12 carbon atoms including isobutene (1-butene), butadiene, isoprene, (meth) acrylic acid ester, (meth) acrylic acid And (meth) acrylamide, vinyl alcohol, vinyl acetate, vinyl chloride, styrene, acrylonitrile and the like.

  Examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, and the like. -Ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene 1-heptene, methyl 1-hexene, dimethyl 1-pentene, ethyl 1-pentene, trimethyl 1-butene, methyl ethyl 1-butene, 1-octene, methyl 1-pentene, ethyl 1- Hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-none , 1-decene, 1-undecene, and 1-dodecene, and the like.

  Examples of polyolefin resins include polyethylene resins, polypropylene resins, polyisobutylene resins, polyisobutene resins, polyisoprene resins, polybutadiene resins, (meth) acrylic resins (so-called allyl resins), vinyl resins such as polyvinyl chloride resins, and poly (meth) resins. 2.) Acrylamide resin, polystyrene resin, acrylonitrile / butadiene / styrene copolymer resin (ABS resin), ethylene / (meth) acrylate copolymer, ethylene / vinyl acetate copolymer, etc. may be mentioned.

  Among these resins, polyethylene resin, polypropylene resin, acrylonitrile / butadiene / styrene copolymer resin (ABS resin) are preferable, and polyethylene resin and polypropylene resin are particularly preferable.

  As a polyethylene resin, an ethylene homopolymer, an ethylene-alpha-olefin copolymer, etc. are mentioned. As the α-olefin, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable.

  Examples of the ethylene-α-olefin copolymer include ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer and the like. It can be mentioned.

  When classified by density or shape, high density polyethylene (HDPE), low density polyethylene (LDPE), ultra low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), ultra high molecular weight polyethylene (UHMW-PE) Any of) may be used.

  As the vinyl resin, for example, vinyl chloride resin [homopolymer of vinyl chloride monomer (polyvinyl chloride resin etc.), copolymer of vinyl chloride monomer and other monomer (vinyl chloride-vinyl acetate copolymer] Coalesced, vinyl chloride- (meth) acrylic acid ester copolymer etc), vinyl alcohol resin (homopolymer such as polyvinyl alcohol, copolymer such as ethylene-vinyl alcohol copolymer), polyvinyl formal etc. Polyvinyl acetal resin etc. are mentioned. These vinyl resins can be used alone or in combination of two or more.

  The thermoplastic resin constituting the cellulose reinforced thermoplastic resin composition used in the present invention is preferably a crosslinkable polyolefin resin. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, linear ultra low density polyethylene, ethylene-propylene block copolymer, ethylene-propylene random copolymer, ethylene-butene block copolymer Polymer, ethylene-butene random copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer resin, ethylene-ethyl acrylate copolymer resin, ethylene-butyl acrylate copolymer resin Etc.

  The polyolefin resin of the base resin may be used alone or in combination of two or more. In addition, when using several polyolefin resin, unless it refuses in particular, the compounding quantity of other components is prescribed | regulated, making the total amount into 100 mass parts of polyolefin resin.

The melt flow rate (MFR) of the polyolefin resin is usually 0.01 to 400 g / 10 min, preferably 1 to 400 g / 10 min, more preferably from the viewpoint of enhancing the mechanical strength and production stability. Is 0.1 to 50 g / 10 min, more preferably 0.4 to 10 g / 10 min.
In the present invention, the mass of the polymer which flows out per 10 minutes under a load of 190 ° C. and 2.16 kg according to JIS K 7210, including graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride, (g / 10) Minutes).

[Graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride]
The base resin, for example, in typical polyethylene, polypropylene, and polystyrene, is composed of only carbon atoms and hydrogen atoms, and has extremely high hydrophobicity.
On the other hand, the surface of the cellulose fiber is a highly polar surface having a hydroxyl group, and the compatibility with the highly hydrophobic thermoplastic resin is low, and it is difficult to uniformly disperse the cellulose fiber.
In the present invention, in order to uniformly disperse a highly hydrophilic cellulose fiber having a hydroxyl group of a polar group in a thermoplastic synthetic resin having high hydrophobicity, a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride is used. It is preferred to use.

The carboxyl group (-CO ₂ H) and -C (= O) -O-C (= O)-bond based on the acid anhydride present in the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride are cellulose fibers The affinity and compatibility with the surface of the cellulose fiber are high due to the hydroxyl group (-OH) on the surface and the interaction such as hydrogen bonding or dipolar interaction.
On the other hand, the polyolefin portion of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride is high in hydrophobicity and similar in structure as the hydrophobic thermoplastic synthetic resin, and has high compatibility and affinity.
This promotes uniform dispersion of the cellulose fibers in the thermoplastic synthetic resin.

  The graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride has a hydrophobic thermoplastic resin and a partial structure which interacts with hydrophilic cellulose in the molecule as described above, and is a hydrophobic thermoplastic resin. Because it acts as an intermediary between H and hydrophilic cellulose, it is classified as a coupling agent.

  Moreover, since the unsaturated carboxylic acid or its anhydride structural portion in the graft modified polyolefin resin of the unsaturated carboxylic acid or its anhydride exists at a very close distance to the hydroxyl group on the surface of the cellulose fiber as described above, cellulose An esterification reaction with the hydroxyl group of the compound occurs easily and efficiently to form a composite resin in which a cellulose and a graft modified polyolefin resin of an unsaturated carboxylic acid or an anhydride thereof are chemically bonded.

  In the present invention, the crosslinking reaction proceeds between the base resin and the cellulose of the cellulose fiber by radicals formed by the decomposition of the organic peroxide to form a strong composite resin. Furthermore, when the thermoplastic synthetic resin contains a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, the organized oxide is a radical reaction between the graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride and the base resin. A cross-linked structure is formed, whereby chemical bonding (covalent bonding) of cellulose, a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and a base resin are all formed to form a stronger composite resin. become.

  The graft-modified unsaturated carboxylic acid or anhydride thereof in the graft-modified polyolefin resin of unsaturated carboxylic acid or anhydride thereof may be a chain compound or a cyclic compound, but a cyclic compound is preferred, and a cyclic unsaturated compound is preferred. Carboxylic anhydrides are more preferred.

  The amount of graft modification with unsaturated carboxylic acid or the anhydride thereof is preferably 0.1 to 25 parts by mass, preferably 0.1 to 10 parts by mass, with respect to 100 parts by mass of the unmodified polyolefin resin. Is more preferable, and 0.1 to 4 parts by mass is further preferable.

  Examples of unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid and methacrylic acid.

  Among the unsaturated carboxylic acid anhydrides, cyclic acid anhydrides include, for example, maleic acid anhydride, citraconic acid anhydride (methyl maleic acid anhydride), 2,3-dimethylmaleic acid anhydride, 2- (2) -Carboxyethyl) -3-methylmaleic anhydride, 2-cyclohexene-1,2-dicarboxylic anhydride, phenylmaleic anhydride, 2,3-diphenylmaleic anhydride, 5,6-dihydro-1, Acid anhydride of maleic acid skeleton such as 4-dithiin-2,3-dicarboxylic anhydride, 2,3-bis (2,4,5-trimethyl-3-thienyl) maleic anhydride, 4-ethynylphthalic acid Anhydride, phthalic acid such as 4,4 '-(ethine-1,2-diyl) diphthalic anhydride, 4- (1-propynyl) phthalic anhydride, 4-phenylethynylphthalic anhydride and the like Anhydrides.

  Among the unsaturated carboxylic acid anhydrides, examples of chain acid anhydrides include acid anhydrides of fumaric acid, itaconic acid, acrylic acid and methacrylic acid, and unsaturated carboxylic acids and saturated aliphatic carboxylic acids thereof. And mixed acid anhydrides with acids, aromatic carboxylic acids and heterocyclic carboxylic acids.

  The unsaturated carboxylic acid anhydride is preferably a cyclic unsaturated carboxylic acid anhydride, more preferably an acid anhydride having a maleic acid skeleton, and particularly preferably a maleic acid anhydride.

  The thermoplastic resin composition used in the present invention comprises graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and graft modified polyolefin resin of said unsaturated carboxylic acid or its anhydride is maleic anhydride modified polyolefin It is preferably a resin.

The polyolefin of the maleic anhydride modified polyolefin is not particularly limited as long as the compatibility with the base resin is good. As the maleic anhydride modified polyolefin, maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, and maleic anhydride modified polystyrene are preferable, but maleic anhydride modified polyethylene and maleic anhydride modified polypropylene are more preferable.
In addition, the maleic anhydride modified copolymer of 2 types of copolymers selected from ethylene, propylene and styrene is also preferable.

Maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene-propylene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer (ethylene-vinyl acetate copolymer, ethylene- Hexene copolymers, ethylene-octene copolymers, etc.) and styrene / ethylene / butylene / styrene (SEBS) having a group containing maleic anhydride. Further, not only maleic anhydride but also polar groups [alkylene glycol type and (meth) acrylic acid type monomer components] may be contained as polar groups to be grafted or copolymerized.
Among them, maleic anhydride-modified polyolefin (polyethylene, polypropylene, polystyrene or copolymers thereof), maleic anhydride-modified ethylene-propylene copolymer, and maleic anhydride-modified ethylene-α-olefin copolymer are particularly preferable among these. A combination (ethylene-vinyl acetate copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, etc.), styrene / ethylene / butylene / styrene (SEBS) having a group containing maleic anhydride.

The maleic anhydride modified polyolefin resin is most preferably maleic anhydride modified polyethylene.
In particular, maleic anhydride modified polyethylene having a melt flow rate (MFR) of 0.3 to 10 g / 10 min at 190 ° C. and a load of 2.16 kg is preferable. In addition, maleic anhydride modified polyethylene having a relative intensity ratio of infrared absorption spectrum measured by infrared absorption spectrum of 0.1 to 0.2 is preferable.

The relative intensity ratio of the infrared absorption spectrum is obtained by thermally pressing maleic anhydride modified polyethylene at 200 ° C. for 5 minutes at 150 ° C. and 200 kgf / cm ² to prepare a 100 μm thick film and measuring the infrared absorption spectrum of this film .
Absorption strength near 1791 cm ^-1 (absorption peak of C = O stretching vibration of saturated five-membered cyclic anhydride derived from maleic anhydride) / absorption strength near 719 cm ^-1 (rock vibrational absorption peak of methylene group derived from polyethylene) It can measure by calculating | requiring the relative intensity ratio of a maleic anhydride modified polyethylene from ratio of 2.).

When the relative intensity ratio of the infrared absorption spectrum is 0.1 to 0.2, the interface of the thermoplastic resin composition can be firmly adhered to the cellulose.
The relative intensity ratio of the infrared absorption spectrum is more preferably 0.15 to 0.2.

The graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride is preferably a polyolefin resin in which the polyolefin resin before modification and the polyolefin base resin not modified with unsaturated carboxylic acid or its anhydride are different .
Here, "different" includes the type of resin component, the difference between monomer components constituting the difference, and the difference in physical properties such as MFR.
The thermoplastic synthetic resin used in the present invention is a mixed resin of graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride and polyolefin resin not modified with unsaturated carboxylic acid or its anhydride. May be

The content of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and 1 to 10 parts by mass with respect to 100 parts by mass of the base resin. Is more preferred.
When the content of the graft modified polyolefin resin of the unsaturated carboxylic acid or the anhydride thereof is too small, the interfacial adhesion effect of the cellulose and the resin is not sufficiently obtained, and the improvement effect of the mechanical strength of the resin composition is not sufficiently obtained. If the content is too large, the strength of the base resin is adversely affected, and the strength of the entire resin composition is reduced.

<Organic peroxide>
The organic peroxide is a polymerization initiator which crosslinks between polymer molecules of a thermoplastic synthetic resin such as a base resin or a graft-modified polyolefin resin of an unsaturated carboxylic acid or an anhydride thereof by a radical reaction.
The organic peroxide is a compound having at least a carbon atom and an -O-O- bond, and examples thereof include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, acyl peroxides, alkyl peroxy esters, Examples include diacyl peroxide, monoperoxy carbonate, and peroxy dicarbonate.
Among these, in the present invention, at least one organic peroxide selected from peroxyketal, dialkyl peroxide, diacyl peroxide, alkylperoxy ester and monoperoxy carbonate is preferable, and dialkyl peroxide is particularly preferable.
As an organic peroxide, the organic peroxide represented by following General formula (1)-(9) is preferable.

In the formula, R ^{1 to} R ⁸ each independently represent an alkyl group, a cycloalkyl group or an aryl group. Here, R ¹ and R ² , and R ³ and R ⁴ may combine with each other to form a ring. n represents an integer of 1 to 6;

The alkyl group may be linear or branched. 1-20 are preferable and, as for carbon number of an alkyl group, 1-12 are more preferable.
3-7 are preferable and, as for the number of ring members of the said cycloalkyl group, 5 or 6 are more preferable. 3-20 are preferable and, as for carbon number of a cycloalkyl group, 3-12 are more preferable. For example, cyclopropyl, cyclopentyl and cyclohexyl can be mentioned.

  The above-mentioned alkyl group and cycloalkyl group may have a substituent, and as such substituent, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group Groups, acyloxy groups, alkyloxycarbonyl groups, aryloxycarbonyl groups, halogen atoms and carboxy groups.

  6-20 are preferable and, as for carbon number of the said aryl group, 6-12 are more preferable. The aryl group may have a substituent, and such a substituent includes an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group and a halogen atom. Examples of the aryl group include phenyl and naphthyl, with phenyl being preferred.

The ring formed by bonding R ¹ and R ² to each other is preferably a 5- or 6-membered saturated carbocyclic ring, and more preferably a cyclopentane ring or a cyclohexane ring.
The ring formed by bonding R ³ and R ⁴ to each other is preferably a 7- to 12-membered ring, and the bond constituting the ring may include —O—O—.

The organic peroxide represented by the general formula (2) is also preferably ^{one in} which R ¹ and R ² are combined with each other to form a ring to form a bis-form as represented by the following general formula (2a).

Wherein, ^{R 3} and ^{R 4,} the general formula (2) have the same meanings as ^{R 3} and ^{R 4,} the preferred range is also the same. L ¹ represents a divalent linking group, and is preferably —O—, —S—, —SO ₂ —, —C (= O) —, an alkylene group or an arylene group.

In the case where R ⁴ is an alkyl group having a substituent, the organic peroxide represented by the general formula (4) is preferably a bis compound as represented by the following general formula (4a).

Wherein, ^{R 3} of the general formula (4) it has the same meaning as ^{R 3} of, and the preferred range is also the same. R ^4a represents an alkylene group, a cycloalkylene group or an arylene group, L ² represents a divalent linking group, and -O-, -S-, -SO _2- , -C (= O)-, an alkylene group , An ethenylene group, an ethynylene group or an arylene group is preferable.

  Among the organic peroxides represented by the general formulas (1) to (9), organic peroxides represented by the general formulas (2), (4) and (6) to (8) are preferable, and in particular The organic peroxide represented by Formula (4) is preferable.

Specific examples of the organic peroxide are given below.
(1) Ketone peroxide compound Cyclohexanone peroxide, linear methyl ethyl ketone peroxide, etc. (2) Peroxyketal compound 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1- Bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-) Butylperoxy) butane, cyclic methyl ethyl ketone peroxide, etc. (3) Hydroperoxide compounds t-butyl peroxide, t-butylcumyl peroxide, etc. (4) dialkyl peroxide compounds di-t-butyl peroxide, t-butylcumyl Ruperoxide, dicumyl peroxide, α α'-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t -Butyl peroxy) hexin-3 etc

(5) Acyl peroxide compound Acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, succinic acid peroxide, benzoylperoxide Oxides, 2,4-dichlorobenzoyl peroxide, m-tolu oil peroxide, etc.

(6) Alkyl peroxy ester compound t-butyl peroxy acetate, t-butyl peroxy isobutyrate, t-butyl peroxy pivalate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-Butyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy laurate, t-butyl peroxybenzoate, di-t-butyl Peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropylcarbonate, cumylperoxy octoate, t-hexylperone Oxy neodecanoate, t-hexylperoxy Bareto, t- butyl peroxy hexanoate, t-hexyl peroxyneodecanoate hexanoate, cumylperoxy neo hexanoate, etc.

(7) Diacyl peroxide compound Diacetyl peroxide, diisobutyryl peroxide, dioctanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, bis (3,5,5-trimethylhexanoyl) peroxide, dibenzoyl Peroxides, bis (2,4-dichlorobenzoyl) peroxides, bis (m-toluoyl) peroxides, etc. (8) Monoperoxycarbonate compounds t-Butylperoxyisopropylcarbonate, t-amylperoxy-2-ethylhexyl carbonate Etc. (9) Peroxydicarbonate compounds Di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-s-butylperoxydicarbonate, bis (4-t-butylate) Cyclohexyl) peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, etc.

The one-minute half-life temperature of the organic peroxide is preferably 130 to 190 ° C.
Here, the half life of the organic peroxide is the time until the organic peroxide is thermally decomposed and the amount of active oxygen becomes half of the amount before decomposition.
If the one-minute half-life temperature of the organic peroxide is too high, the temperature setting in the twin-screw extruder becomes difficult, and conversely, if it is too low, the organic peroxide itself becomes unstable and is decomposed during storage.
By setting the one-minute half-life temperature of the organic peroxide to the above range, heating and kneading can be performed with a commonly performed twin-screw extruder, and cellulose is uniformly dispersed in a highly hydrophobic resin. Is possible.

  The organic peroxide's one-minute half-life temperature is the organic peroxide when it is thermally decomposed by using a relatively inert solvent such as benzene and adjusting an organic peroxide solution with a concentration of 0.1 mol / L. It can be determined by measuring the time change of the peroxide concentration (See “Crosslinker Handbook (First Edition)”, published by Taisei Corporation, page 162).

The content of the organic peroxide is preferably 0.01 to 0.30 parts by mass, more preferably 0.05 to 0.20 parts by mass, and 0.05 to 0 parts by mass with respect to 100 parts by mass of the thermoplastic synthetic resin. .1 part by mass is more preferred.
When the content of the organic peroxide is too small, the effect of improving the mechanical strength of the resin composition can not be sufficiently obtained. When the content of the organic peroxide is too large, the heat flowability of the resin composition becomes low and molding becomes difficult.

RO · (radicals) consisting of decomposition of organic peroxides extract hydrogen atoms of the base resin and cellulose, respectively, to generate these radicals. It is inferred that the generated base resin radical and the cellulose radical bond and the interface between the base resin and the cellulose adheres.
The above-mentioned interfacial adhesion reaction is as follows when the base resin is polyethylene, for example.

  Here, PE-H is polyethylene, Cellulose-H is cellulose, and PE ·, Cellulose · is a generated radical.

<Cellulose>
The cellulose used in the present invention is a fibrous cellulose, preferably a fibrous cellulose derived from plants, and particularly preferably a fibrous cellulose derived from fine plants (powdered pulp). The exterior part for vehicles provided with the resin part of the present invention uses cellulose as the compounding material of the resin part, so that weight reduction and high strength can be achieved, and the surface smoothness and coloring property of the exterior part for vehicles Can be improved. Moreover, since cellulose is a polar molecule which has -OH group, the affinity between molecules is high. Therefore, the interfacial adhesive force of the resin portion is improved, and the vehicle exterior component excellent in adhesive performance can be obtained.
Pulp is also a raw material of paper and is mainly composed of a tracheid extracted from plants. Chemically, the main component is polysaccharides, and the main component is cellulose.
The fibrous cellulose of plant origin is not particularly limited, but for example, wood, bamboo, hemp, jute, kenaf, agricultural waste (eg, straw of wheat or rice, stem of corn, cotton etc., Examples are those derived from plants such as sugar cane), cloth, regenerated pulp and waste paper, but in the present invention, those derived from wood or wood are preferable, and kraft pulp is particularly preferable.
Kraft pulp is a general term for pulp from which lignin and hemicellulose are removed from wood or plant material by chemical treatment with caustic soda or the like, and almost pure cellulose is taken out.

  The diameter of the cellulose used in the present invention is preferably 1 to 30 μm, more preferably 1 to 20 μm, and still more preferably 5 to 15 μm. The length (fiber length) is preferably 10 to 100 μm, and more preferably 20 to 50 μm.

In the present invention, the blending amount of cellulose is preferably 5 to 70 parts by mass, more preferably 10 to 60 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the thermoplastic synthetic resin.
If the blending amount of the cellulose is less than 5 parts by mass, a sufficient resin reinforcing effect can not be obtained, while if it exceeds 70 parts by mass, the heat flowability of the resin composition is reduced and the molding processability is reduced. In some cases, the mechanical strength may be reduced.

<Other additives>
The thermoplastic resin composition used in the present invention includes inorganic fillers such as talc, calcium carbonate, mica, glass fibers, etc., or organic fillers such as polyester, polyamide fibers etc., and other flame retardants. Various additives such as stabilizers, antioxidants, infrared absorbers, plasticizers, and lubricants, dyes, and colorants of pigments can be added.

The component which comprises the thermoplastic resin composition used for this invention mix | blends the quantity which exists in the general range except containing 5-70 mass parts of cellulose with respect to 100 mass parts of thermoplastic synthetic resins. Although it is possible, it is most preferred that all components be incorporated in amounts which are in the preferred range.
However, there is no change in that it is a preferable aspect that the specific component is in the preferable range and the other components are blended in the general range.

<< Cellulose Reinforced Thermoplastic Resin Composition and Method for Producing the Same >>
The cellulose reinforced thermoplastic resin composition used in the present invention is produced from the above-mentioned thermoplastic resin composition.
The cellulose-reinforced thermoplastic resin composition used in the present invention is obtained by heat-kneading the above-mentioned thermoplastic resin composition and reacting the components.
In the above reaction, the hydrogen atoms of the cellulose of the base resin and the cellulose fiber react with the organic peroxide which is a radical reaction initiator, and the crosslinking reaction proceeds between the base resin and the cellulose fiber. Furthermore, when the thermoplastic synthetic resin contains a graft-modified polyolefin resin of an unsaturated carboxylic acid or its anhydride, the graft-modified polyolefin resin of the unsaturated carboxylic acid or its anhydride reacts with the cellulose to convert the hydroxyl group and carboxy group of the cellulose. An ester bond is formed with the cross-linked polyolefin resin.

  Therefore, the cellulose reinforced thermoplastic resin composition used in the present invention has a crosslinked structure between the thermoplastic synthetic resin and the cellulose cellulose fiber, and further, a crosslinked polyolefin having a cellulose hydroxyl group and a carboxy group. It contains an ester bond complex resin (complex) with the resin. Here, the content of the cellulose component in the ester bond composite resin is 9.0 to 42% by mass, and the tensile strength of the resin comprising the cellulose reinforced thermoplastic resin composition is measured according to JIS K 7161. The strength is 40 MPa or more. The content ratio of the cellulose component in the ester bond composite resin (composite) is the thermoplasticity contained in the thermoplastic resin composition for obtaining a cellulose reinforced thermoplastic resin composition as a component constituting the composite. It shall calculate as a cellulose component to the sum total of content of a synthetic resin component and a cellulose component.

  In addition to the above, the crosslinking reaction caused by the organic peroxide which is a radical reaction initiator consists of carbon atoms of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride and unsaturated carboxylic acid or its anhydride It also forms a crosslinked structure in which carbon atoms of the main chain of the non-modified polyolefin resin are bonded at two or more places.

  Therefore, the cross-linked polyolefin resin having a carboxy group is mainly composed of carbon atoms of the main chain of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride and the polyolefin resin which is not modified with unsaturated carboxylic acid or its anhydride. It is preferable that it is a polyolefin resin of the crosslinked structure which the carbon atom of the chain | strand couple | bonded in two or more places. When the thermoplastic resin composition contains a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, the component constituting the complex contains the graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride. Be

  At this time, as with the thermoplastic resin composition described above, the polyolefin resin before modification of the graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and polyolefin resin not modified with unsaturated carboxylic acid or its anhydride May be different polyolefin resins.

  In addition, similar to the cellulose contained in the above-mentioned thermoplastic resin composition, the cellulose contained in the cellulose-reinforced thermoplastic resin composition is preferably fibrous cellulose of plant origin, and in particular, fibrous cellulose of fine plant origin (Powdery pulp) is preferred.

As described above, the thermoplastic resin composition is heat-kneaded to produce a cellulose-reinforced thermoplastic resin composition.
The apparatus used for the heating and kneading is not particularly limited as long as the heating and kneading can be performed at the temperature at which the organic peroxide is thermally decomposed, and, for example, a blender, a kneader, a mixing roll, a Banbury mixer, uniaxial or biaxial An extruder etc. are mentioned.
Among these, a twin-screw extruder is preferred.
In the twin-screw extruder, each component is directly charged into the hopper portion of the twin-screw extruder by a weight feeder, and the setting temperature of the kneading zone is set to the above temperature by the twin-screw extruder to knead it. The cellulose-reinforced thermoplastic resin composition can be obtained by reacting in the above.

The cellulose-reinforced thermoplastic resin composition may be prepared by separately preparing the thermoplastic resin composition used in the present invention. For example, an extruder [for example, Technobel Co., Ltd. KZW 15 TW- In the step of producing a cellulose reinforced thermoplastic resin composition with a twin screw extruder such as 45MG-NH, each component is fed to the extruder by means of a feeder controlled by the feed mass per hour, into the extruder hopper, As a result, it is preferable to manufacture by heat-kneading the obtained thermoplastic resin composition.
In such a method, existing equipment and equipment can be used without changing the equipment, and at the same time as preparation of the thermoplastic resin composition, a cellulose reinforced thermoplastic resin composition can be produced.

As described above, each component is charged into the hopper of the extruder, and, for example, the parelle temperature of the kneading zone is set to the temperature at which the organic peroxide is thermally decomposed, and heat kneading is performed.
The kneading temperature is set to be higher than the one-minute half-life temperature of the organic peroxide. A temperature 5 ° C. or more higher than the one-minute half-life temperature of the organic peroxide is preferable, a temperature 10 ° C. or more is more preferable, a temperature 15 ° C. or more is more preferable, and a temperature 20 ° C. or more is most preferable.
When using a common organic peroxide, the kneading temperature is preferably 150 to 200 ° C.

For heat kneading, for example, screw diameter is 15 mm, L / D = 45, and screw rotation speed of 100 rpm is sufficient.
The kneading time is not particularly limited, but may be a general reaction time when using a common organic peroxide.

  When a cellulose reinforced thermoplastic resin composition is manufactured using an extruder, it can also be used for manufacture of a vehicle exterior component provided with a resin part by making a cellulose reinforced thermoplastic resin composition into a pellet.

  In addition, since the cellulose reinforced thermoplastic resin composition contains the organic peroxide, the decomposition residue of the organic peroxide may remain by reacting by heating and kneading, and as a result, the cellulose reinforced heat may be produced. It may be contained in the plastic resin composition.

<< Exterior parts for vehicles and method of manufacturing the same >>
The resin portion of the exterior part for a vehicle according to the present invention is formed using a cellulose reinforced thermoplastic resin composition obtained by heat-kneading the thermoplastic resin composition used in the present invention. That is, the resin part which is the whole or a part of the exterior part for a vehicle of the present invention is the thermoplastic resin produced by the method for producing the cellulose reinforced thermoplastic resin composition, particularly, the cellulose reinforced thermoplastic resin composition. The composition is molded, for example by injection, extrusion.

  FIG. 1 is a schematic view showing an example of a vehicle provided with a vehicle exterior part according to an embodiment of the present invention. As shown in the figure, the vehicle exterior parts are various exterior parts attached to the vehicle 1, and for example, the front fender 2, the back door 3, the rear spoiler 4, the front spoiler 5, the side spoiler 6, the under panel 7, The rear fender 8, the roof panel 9, the side mirror cover 10, the fuel tank flap 11, or the door knob 12. Among them, preferably, the vehicle exterior part is the front fender 2, the back door 3 or the rear spoiler 4.

  The front fender 2 is disposed on the front side of the vehicle 1 and on the left and right sides of the vehicle width. The front fender 2 is, for example, an inner member disposed inward in the vehicle width direction and attached so as to surround the outer periphery of the tire, and disposed outward in the vehicle width direction to reduce air resistance of the tire. And an outer member attached to the One or both of the inner member and the outer member are formed of the thermoplastic resin composition.

  The back door 3 is attached to the rear side of the vehicle 1 so as to be openable and closable together with mechanical parts such as a backlight and a glass plate. The back door 3 has an inner panel disposed inward in the vehicle length direction and an outer panel disposed outward in the vehicle length direction. One or both of the inner panel and the outer panel are formed of the thermoplastic resin composition.

  The rear spoiler 4 is disposed on the rear side of the vehicle 1 and on the upper side in the vehicle height direction, and extends in the vehicle width direction so as to change the airflow flowing along the roof panel of the vehicle 1 to reduce lift. Installed. The rear spoiler 4 has a front panel, and at least the front panel is formed of the above-mentioned thermoplastic resin composition. The rear spoiler 4 may be entirely formed of the above-mentioned thermoplastic resin composition.

  The vehicle exterior parts of the present invention include front fender 2, back door 3, rear spoiler 4, front spoiler 5, side spoiler 6, under panel 7, rear fender 8, roof panel 9, side mirror cover 10, fuel tank flap 11 and It may be one or more parts selected from the group consisting of the doorknob 12. Moreover, when said each exterior component for vehicles has a several component, at least one of this several component may be formed with the thermoplastic composition of this invention.

  The vehicle 1 to which the vehicle exterior part of the present invention is applied is a one-box type, but not limited to this, a sedan type, coupe type, SUV type, hard top type, hatchback type, minivan type, convertible type, station It may be a wagon type or a pickup type. In addition, the vehicle 1 may include an engine driven by fuel such as gasoline, light oil, hydrogen and the like, a motor driven by electric power supplied from a battery or the like, or both the engine and the motor as a power source.

  Examples of applications of the thermoplastic composition of the present invention include exterior parts for vehicles constituting vehicles such as automobiles, such as two-wheeled vehicles and four-wheeled vehicles, and trains. In addition to the above, as an application of the thermoplastic resin composition, there can be mentioned exterior parts for moving bodies that constitute moving bodies such as aircraft, ships, robots and the like.

  In the exterior part for vehicles provided with the resin part according to the present invention, the resin part is formed using the cellulose reinforced thermoplastic resin composition obtained by heating and kneading the thermoplastic resin composition used in the present invention Ru. That is, the resin portion is formed from a cellulose reinforced resin composition containing an ester bond composite resin (composite) of a cellulose hydroxyl group and a crosslinkable polyolefin resin having a carboxy group, and the cellulose occupied in the ester bond composite resin Content of a component is 9.0-42 mass%, The tensile strength measured based on JISK7161 of resin which consists of the said cellulose reinforced thermoplastic resin composition is 40 Mpa or more.

  The exterior part for a vehicle provided with the resin part according to the present invention is obtained as described above because the interfacial adhesion between the thermoplastic synthetic resin and the cellulose is improved by the use of the cellulose reinforced thermoplastic resin composition. The resin portion of the exterior part for a vehicle is excellent in mechanical strength such as rigidity and tensile strength.

EXAMPLES The present invention will be described in more detail based on examples given below, but the invention is not meant to be limited by these.
The materials used are shown below.

<Material used>
(1) Thermoplastic synthetic resin (base resin)
・ High density polyethylene (HDPE)
MFR (190 ° C./2.16 kg) = 5 g / 10 min Density = 0.953 g / cm ³
(Maleic anhydride modified polyethylene)
· Maleic anhydride modified polyethylene A
MFR (190 ° C./2.16 kg) = 9.0 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.15
· Maleic anhydride modified polyethylene B
MFR (190 ° C./2.16 kg) = 0.4 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.14
· Maleic anhydride modified polyethylene C
MFR (190 ° C./2.16 kg) = 3.4 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.10
· Maleic anhydride modified polyethylene D
MFR (190 ° C./2.16 kg) = 4.4 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.16
· Maleic anhydride modified polyethylene E
MFR (190 ° C./2.16 kg) = 1.3 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.17
· Maleic anhydride modified polyethylene F
MFR (190 ° C./2.16 kg) = 1.2 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.16
· Maleic anhydride modified polyethylene G
MFR (190 ° C./2.16 kg) = 1.1 g / 10 min Relative intensity ratio of infrared absorption spectrum = 0.12

(2) Cellulose pulp (manufactured by Nippon Paper Chemicals Co., Ltd., trade name: KC Flock W-200, powdered cellulose having an average particle diameter of about 32 μm)

(3) Organic peroxide, peroxyketal (manufactured by NOF Corporation, trade name: Perhexa C)
・ Dialkyl peroxide A (manufactured by NOF Corporation, trade name: Perhexa 25B)
・ Dialkyl peroxide B (manufactured by NOF Corporation, trade name: Park Mill D)
・ Dialkyl peroxide C (manufactured by NOF Corporation, trade name: Perbutyl D)
・ Diacyl peroxide (manufactured by NOF Corporation, trade name: Niper FF)
・ Alkylperoxy ester (manufactured by NOF Corporation, trade name: Perbutyl A)
・ Mono peroxy carbonate (manufactured by NOF Corporation, trade name: Perhexyl I)

  First, a common manufacturing method, a molding method, and a physical property evaluation method performed in each example and comparative example will be shown.

<Production Method of Cellulose Reinforced Thermoplastic Resin Composition>
The heat in which the (1) thermoplastic synthetic resin (base resin, maleic anhydride modified polyethylene), (2) cellulose, and (3) organic peroxide are contained in the contents shown in the following Tables 1 to 5 respectively A plastic resin composition was produced. The thermoplastic resin composition thus obtained is introduced into the hopper of a twin-screw extruder having a screw diameter of 15 mm and L / D = 45 [Koberu KZW 15 TW-45 MG-NH] with a feeder controlled by the mass supplied per hour. did. The parelle temperature was set 20 ° C. higher than the one-minute half-life temperature of the organic peroxide, and the screw rotation speed was 100 rpm, and heat kneading was carried out to obtain a cellulose reinforced thermoplastic resin composition.
In addition, when a thermoplastic synthetic resin contains maleic anhydride modified polyethylene, in Table 1-5, the used maleic anhydride modified polyethylene was described as a coupling agent for convenience.

<Method of Manufacturing Exterior Parts for Vehicles Including Resin Portion>
It injection-molded using the cellulose reinforcement thermoplastic resin composition prepared above, and the exterior component for vehicles provided with the resin part was produced. In addition, injection conditions were implemented on the shaping | molding conditions made generally appropriate.

<Method of Forming Test Piece of Exterior Part for Vehicle Equipped with Resin Part for Tensile Strength Evaluation>
The cellulose-reinforced thermoplastic resin composition pellet obtained above is dried at 80 ° C. for 24 hours, and it conforms to JIS K 7127 test strip type 2 using an injection molding machine (Robot Shot α-30C manufactured by FANUC Co., Ltd.) Then, a tensile test piece of a vehicle exterior part provided with a resin portion was produced.

(Evaluation method of tensile strength)
According to JIS K 7161, the tensile strength (MPa) of the tensile test piece prepared above was measured by using a tensile tester (Instron's Instron testing machine 5567 type), with 25 mm inter-wire distance, test speed: 50 mm It measured on the conditions of / min.

<Measurement of physical properties of materials used>
The relative strength ratio of the base resin of thermoplastic synthetic resin and the MFR of maleic anhydride modified polyethylene A to G, the infrared absorption spectrum of maleic anhydride modified polyethylene A to G, and the 1 minute half-life temperature of the organic peroxide used , And measured as follows.

(MFR measurement method)
According to JIS K 7210, using a melt indexer (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the mass (g / 10 min) of the polymer flowing out per 10 minutes under a load of 190 ° C. and a load of 2.16 kg was determined. .

(Method of measuring relative intensity ratio of infrared absorption spectrum)
Each maleic anhydride-modified polyethylene was heat-pressed at 150 ° C. and 200 kgf / cm ² for 5 minutes to produce a film of 100 μm in thickness. The infrared absorption spectrum of the film was measured, from the ratio of the absorption intensity of absorption intensity / 719Cm around ^-1 around 1791Cm ^-1, was determined relative intensity ratio.

(1 minute half-life temperature measurement method of organic peroxide)
The organic peroxide is decomposed by heat, and the half-life, which is the time until the amount of active oxygen becomes half of the amount before decomposition, adjusts the benzene solution of organic peroxide with a concentration of 0.1 mol / L. It was determined by measuring the time change of the organic peroxide concentration when thermally decomposed.

Example 1
A thermoplastic resin composition comprising 11 parts by mass of cellulose, 1 part by mass of maleic anhydride-modified polyethylene A, and 0.1 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene is 2.) The mixture was heated and kneaded with Technobel KZW15TW-45MG-NH to obtain pellets of a cellulose-reinforced thermoplastic resin.
Next, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced with an injection molding machine (FANC Co., Ltd. product robot shot α-30C) for the above-mentioned pellet.

Examples 2 to 5
A vehicle provided with a resin portion for tensile strength evaluation in the same manner as in Example 1 except that in the thermoplastic resin composition of Example 1 the blending amount of maleic anhydride modified polyethylene A is changed as shown in Table 1 below The test piece as an exterior component was produced.

Example 6
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 2 parts by mass of maleic anhydride-modified polyethylene A, and 0.05 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 7
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.05 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 8
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 10 parts by mass of maleic anhydride-modified polyethylene A, and 0.05 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 9
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.01 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 10
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.03 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 11
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.12 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 12
The thermoplastic resin composition of Example 1 was changed to 43 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.1 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 13
The thermoplastic resin composition of Example 1 was changed to 73 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.1 parts by mass of dialkyl peroxide A with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 14
In the thermoplastic resin composition of Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation in the same manner as in Example 1 except that maleic anhydride modified polyethylene A was not used. Was produced.

Examples 15 to 20
In the thermoplastic resin composition of Example 1, a vehicle exterior provided with a resin portion for tensile strength evaluation in the same manner as in Example 1 except that the type of maleic anhydride-modified polyethylene is changed to the type shown in Table 3 below. Test pieces as parts were produced.

Example 21
In the thermoplastic resin composition of Example 1, the procedure was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.1 parts by mass of peroxyketal with respect to 100 parts by mass of high density polyethylene. In the same manner as Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 22
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.17 parts by mass of dialkyl peroxide B with respect to 100 parts by mass of high density polyethylene. In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 23
In the thermoplastic resin composition of Example 1, the procedure was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.30 parts by mass of diacyl peroxide with respect to 100 parts by mass of high density polyethylene. In the same manner as Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 24
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.09 parts by mass of dialkyl peroxide C with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 25
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.16 parts by mass of alkylperoxy ester with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Example 26
The thermoplastic resin composition of Example 1 was changed to 11 parts by mass of cellulose, 5 parts by mass of maleic anhydride-modified polyethylene A, and 0.14 parts by mass of monoperoxycarbonate with respect to 100 parts by mass of high density polyethylene In the same manner as in Example 1, a test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced.

Comparative Example 1
A test piece as a vehicle exterior part provided with a resin part for tensile strength evaluation was produced in the same manner as Example 1 except that maleic anhydride-modified polyethylene A and an organic peroxide were not used.

Comparative example 2
In the same manner as in Example 1 except that the organic peroxide was not used, a test piece as an exterior part for a vehicle provided with a resin portion for tensile strength evaluation was produced.

The obtained results are summarized in Tables 1 to 5 below.
In addition, the thing of each raw material component in a table | surface shows that the thing of blank is unused, or, for this, it is unevaluated.

  As apparent from Tables 1 to 5 above, a vehicle exterior provided with a resin portion formed of a cellulose reinforced thermoplastic resin composition obtained using the thermoplastic resin composition of Examples 1 to 26 of the present invention The test pieces of the parts were able to achieve a tensile strength of 40 MPa or more measured in accordance with JIS K 7161 as compared to the test pieces of the vehicle exterior parts provided with the resin portions of Comparative Examples 1 and 2. From this, the thermoplastic resin composition of Examples 1 to 26 in which the cellulose is uniformly dispersed and contained, and the cellulose reinforced thermoplastic resin composition obtained by using the thermoplastic resin composition are molding materials It has been found that it has an action capable of improving the mechanical strength of Further, in Examples 1 to 26, since the thermoplastic resin composition and the cellulose reinforced thermoplastic resin composition having such an action are used, a vehicle exterior component comprising a resin part having improved mechanical strength is obtained. It could be made.

  The cellulose-reinforced thermoplastic resin composition obtained by using the thermoplastic resin composition of Examples 1 to 26 of the present invention has improved tensile strength and high reinforcement efficiency of the cellulose-reinforced thermoplastic resin, so that the cellulose-reinforced thermoplastic resin composition is reinforced. It turns out that it is useful as a vehicle exterior component provided with the resin part as resin. Moreover, since a cellulose reinforcement thermoplastic resin composition is obtained from the thermoplastic resin composition of Examples 1-26, the exterior component for vehicles provided with the resin part shape | molded from the said cellulose reinforcement thermoplastic resin composition is: It can be judged that it is lightweight, has high strength, and is excellent in recyclability, surface smoothness, and adhesion performance.

1 vehicle 2 front fender 3 back door 4 rear spoiler 5 front spoiler 6 side spoiler 7 under panel 8 rear fender 9 roof panel 10 side mirror cover 11 fuel tank flap 12 door knob

Claims (14)

  A thermoplastic resin composition containing 5 to 70 parts by mass of cellulose and 100 parts by mass of a thermoplastic synthetic resin, and containing an organic peroxide, wherein the resin comprises the thermoplastic resin composition according to JIS K 7161 The exterior component for vehicles provided with the resin part formed with the thermoplastic resin composition whose tensile strength measured based on (40) is 40 MPa or more.   The vehicle exterior part according to claim 1, wherein the thermoplastic synthetic resin comprises a graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride.   The exterior part for vehicles according to claim 1 or 2 whose half-life temperature of said 1 minute of said organic peroxide is 130-190 ° C.   The organic peroxide is at least one organic peroxide selected from dialkyl peroxide, peroxy ketal, diacyl peroxide, alkyl peroxy ester and monoperoxy carbonate. Vehicle exterior parts according to item 1.   The vehicle exterior part according to any one of claims 1 to 4, wherein the content of the organic peroxide is 0.01 to 0.30 parts by mass with respect to 100 parts by mass of the thermoplastic synthetic resin. .   The thermoplastic synthetic resin comprises a graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and the graft-modified polyolefin resin of unsaturated carboxylic acid or its anhydride is a maleic anhydride-modified polyolefin resin. The exterior part for vehicles of any one of -5.   The said thermoplastic synthetic resin is a mixed resin of graft modified polyolefin resin of unsaturated carboxylic acid or its anhydride, and polyolefin resin which is not denatured by unsaturated carboxylic acid or its anhydride. Vehicle exterior parts according to any one of the preceding claims.   The exterior part for vehicles according to any one of claims 1 to 7, wherein the cellulose is a fibrous cellulose of plant origin.   8. A cellulose-reinforced thermoplastic resin composition comprising an ester bond composite resin of a cellulose hydroxyl group and a cross-linked polyolefin resin having a carboxy group, wherein the content of the cellulose component in the ester bond composite resin is 9. A resin portion formed of a cellulose-reinforced thermoplastic resin composition having a tensile strength of 40 MPa or more which is 0 to 42% by mass and which is measured according to JIS K 7161 of the resin comprising the cellulose-reinforced thermoplastic resin composition Exterior parts for vehicles.   The crosslinkable polyolefin resin having a carboxy group is a main chain of a graft modified polyolefin resin of an unsaturated carboxylic acid or its anhydride, and a main chain of a polyolefin resin which is not modified with an unsaturated carboxylic acid or its anhydride. The exterior part for a vehicle according to claim 9, which is a polyolefin resin having a cross-linked structure in which carbon atoms of R are bonded at two or more places.   The polyolefin resin before modification of the graft modified polyolefin resin of the unsaturated carboxylic acid or the anhydride thereof and the polyolefin resin which is not modified with the unsaturated carboxylic acid or the anhydride thereof are different polyolefin resins. An exterior part for a vehicle according to claim 10.   The exterior part for vehicles according to any one of claims 9 to 11, wherein the cellulose is a fibrous cellulose of plant origin.   The exterior part for a vehicle according to any one of claims 1 to 12, which is a fender, a back door or a spoiler. The back door includes an inner panel and an outer panel.
The vehicle exterior part according to claim 13, wherein one or both of the inner panel and the outer panel are formed of the thermoplastic resin composition.

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