JPH0737130B2 - Interior materials for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle interior material such as a frame of an instrument panel.

[0002]

2. Description of the Related Art Various types of interior materials for vehicles are known, such as door trims, body side trims, instrument panels and floor consoles. Among these interior materials, for example, an instrument panel is divided into a metal instrument and a trim instrument in terms of its assembling.
Of these, the trim instrument is a frame made of steel plate pressed product or resin integrally molded product, and after assembling parts to it, it is assembled with bolts on the vehicle body, so it is possible to pre-assemble parts on the sub-assembly line, so work It has been adopted for most cars in recent years due to its good performance and the advantages such as fine adjustment of construction and easy checking required.

By the way, the frame forming the main body of such a trim instrument has the following advantages due to the rapid progress of the resin molding technique, and therefore, the one formed by resin integral molding is often used. ing. (A) A large size can be integrally molded including the detailed shape of the back surface. (B) Not only the texture (pattern) and color, but also the deeply carved shape can be freely used. (C) Since the dimensional accuracy is good, the assembling property is good. (D) It is easy to control strength and rigidity. (E) The weight can be reduced. Then, as a resin material which can be applied to such a frame, polyphenylene oxide, polypropylene mixed with filler, ABS resin, acrylonitrile mixed with glass fiber, styrene copolymer (ASG) and the like are known.

[0004]

However, in recent years, the quality of vehicles has become higher, and for example, the instrument frame is made of wood, or wood is added to the instrument frame by printing or the like to give the interior a handmade feeling. , It has been done to calm the inside of the car. However, if the frame is made of wood, cost increase cannot be avoided because mass production is less efficient than resin-integrated molded products, and the dimensional accuracy is inferior. There are problems such as deformation due to humidity. On the other hand, the resin-integrated molded product with a woody appearance does not give a sufficient woody texture due to printing, etc., and it has not reached the original purpose of giving a high-class feeling or a handmade feeling. .

In particular, polypropylene as a resin material is
Although its use is desired because of its excellent heat resistance and impact resistance, low cost, simple structure and easy recycling, this material is inferior in adhesiveness to ABS resin etc. For this reason, the paste was poorly glued, the resin itself did not absorb the paint, and the color of itself was candle-like, so it was extremely difficult to make it woody. In addition, in order to improve the adhesiveness of the polypropylene resin itself and the absorbability of paint, for example, Japanese Patent Publication No.
As suggested in No. 2-14576, it is also possible to add wood powder to a polypropylene resin. But,
Conventionally commonly used wood powder is obtained by directly pulverizing wood into fine powder, but this wood powder does not have a grain shape, and as shown in FIG. 7, most of it is fibrous. ,
Even if the particle diameter measured on the minor axis side is a few microns, the major axis side is long like a cilia, and when mixed with a resin, wood powder often entangles with each other to create an agglomerated state. However, it has the disadvantage that it is not uniformly dispersed. Further, since the particle size of the crushed wood powder is extremely varied, it is easy to cause molding distortion or the like in the molded resin product, and the mechanical strength is partially different.

[0006] Therefore, even if such a wood powder is blended to form a polypropylene resin into a desired shape, the wood powder is fibrous and does not disperse uniformly in the resin. For example, it is impossible to obtain a material having a sufficient wood texture because of unevenness in the texture and inferior texture due to fluffiness on the surface. The present invention has been made in view of the above circumstances, and an object thereof is to have an interior material for a vehicle, which has a woody appearance comparable to that of a natural wood product, and which is not deformed by moisture permeability. Is to provide wood.

[0007]

Means for Solving the Problems In a vehicle interior material of the present invention, a grinding treatment is performed, and a finely divided cellulose-based powder in which a white inorganic pigment is carried in a state of being bitten on the surface is mixed with a polypropylene resin, The mixture is molded by extrusion or injection molding, the coated surface of the molded body is ground, and the coating is applied to the ground surface.

[0008]

According to the vehicle interior material of the present invention, the surface is sufficiently white due to the white pigment carried in the bite state, and the pigment-carrying cellulose-based fine powder particles are ground. Unlike the one in which conventional wood is pulverized directly into fine powder, which is fibrous, the surface has few cilia and is granular, so that the surface of the molded body does not get fluffy,
Improves the feel. In addition, since the cellulose-based fine powder particles are not fibrous but are granular, when fibrous substances are mixed and dispersed, the fibrous parts are entangled to form a dumpling or a cotton-like product. Since they are dispersed in an independent state, the pigment-carrying fine particles themselves have extremely good dispersibility with respect to the polypropylene resin, and thus the obtained molded product also has a sufficiently uniform material.

Further, since the cellulose fine particles are not fibrous but granular, they expand and contract due to adsorbing or releasing water (including moisture) and solvent like conventional fibrous wood powder. Therefore, the interior material for a vehicle containing this is excellent in dimensional stability even though the polypropylene resin itself is inferior in dimensional stability. In addition, since the cellulose-based fine powder particles supporting the pigment on the surface are used as the aggregate, the pigment covers the surface of the fine powder particles, so that the adsorption and suction of the resin by the fine powder particles is extremely reduced, which may cause molding distortion. It almost disappears.

In addition, in this vehicle interior material, since the cellulose-based fine powder particles carry the inorganic pigment, the heat resistance is improved as compared with that before the loading, so that the cellulose-based fine powder such as wood powder is simply used. Compared with the case of blending with granules, the heat effect at the time of molding is less than that in the case of molding, so that deterioration such as change in color or shape is suppressed. Further, the surface of the cellulose-based fine powder particles is covered by supporting the pigment, thereby suppressing the release of glycine and formic acid contained in the fine powder particles at the time of molding. Molding defects due to release are prevented. Further, in this vehicle interior material, the surface area of the cellulosic fine powder particles is larger than that of conventional wood powder because the pigment is carried, and therefore the fine powder particles and resin are Increases the degree of adhesion.

Further, in this vehicle interior material, since the molded body was subjected to the grinding treatment, the white inorganic pigment-carrying cellulosic fine particles located facing the outer surface on the grinding treated surface were
The pigment-supported portion is scraped off and the inner surface of the cellulose fine powder particles faces the grinding-treated surface, so that the surface of the molded article has a rich wood texture. Further, by applying the coating material to the grinding-treated surface facing the inner surface of the cellulose fine powder particles, the coating material is directly sucked into the cellulosic fine powder particles, whereby the coating material is well adhered to the molded body.

[0012]

The present invention will be described in detail below. The interior material for a vehicle of the present invention includes a frame portion of an instrument panel (a main body portion on which parts such as meters are mounted) as shown in FIG. 1, a finisher or a main body portion of a floor console as shown in FIG. It is applied to a panel portion of a door trim or a body side trim, etc., and uses polypropylene resin (hereinafter abbreviated as PP) as a resin material for forming the same. There is no particular limitation on the degree of polymerization of the PP, and any PP can be used. In addition, it is needless to say that even a polyolefin such as an ethylene-propylene copolymer having a content of propylene that is higher than the content of other olefins is within the range of the “polypropylene resin” in the present invention. .

Hereinafter, the vehicle interior material of the present invention will be described based on its manufacturing method. First, the above-mentioned PP is mixed with cellulose-based fine powder particles carrying a white inorganic pigment in a bite state, and if necessary, known additives are mixed and mixed, and then the mixture is extruded or injection-molded into a desired shape. For example, it is molded into the frame shape of the instrument panel shown in FIG. 1, the finisher shape of the floor console as shown in FIG. 2, or the main body portion shape. here,
As cellulosic fine particles that carry white inorganic pigment in a bite state, coarsely ground wood, coarsely ground bacas, coarsely ground rice straw, etc. What was obtained by processing is used. In order to obtain a coarsely crushed raw material, the chips and the like are crushed by mechanical impact crushing to obtain 150 mesh, preferably 12 mesh.
A coarsely pulverized powder having a particle size smaller than 0 mesh is obtained. Here, for mechanical grinding, for example, an impeller mill (IMP-2
50; manufactured by Seishin Enterprise Co., Ltd.) is preferably used.

The grinding treatment of the pulverized raw material material is preferably performed by, for example, a ball mill shown in FIG. In this ball mill, a cooling jacket 2 is provided on the peripheral wall of an atmosphere-releasing mill body 1. Cooling water is circulated by supplying cooling water from a supply pipe 8 into the cooling jacket 2 and discharging it from a drain pipe 9. By doing so, the temperature inside the mill body 1 is set to a preset temperature, for example, 80 ° C. or lower. Here, a motor 5 is arranged on the upper part of the mill body 1, and a rotor 4 for stirring the balls 3 in the mill body 1 is arranged on the bottom part of the motor 5. The rotor 4 is rotated by the drive of the motor 5 and agitates the ball 3 and the object to be ground to bring them into mechanical contact with each other. Further, an outlet 7 that is opened and closed by a valve 6 is provided in the lower part of the cone of the mill body 1 so that the object to be ground after the grinding can be discharged.

The balls 3 loaded in the mill body 1 of this ball mill are ceramic balls having an outer diameter of 3 mm to 5 mm,
In particular, it is preferable to use zirconia-based or alumina-based ceramic balls, and it is preferable to avoid using balls made of metal such as stainless steel and steel. This is because in the case of metal balls such as stainless steel and steel, crushed cellulosic powder such as wood powder may adhere to the surface of the balls, or the pulverized powder may be deteriorated due to heat generated by mutual contact between the metal balls. This is also because there is a possibility that fragments of metal balls or the like will be generated, and the fragments will be carried on the surface of the pulverized cellulose and become different from the desired fine powder particles. The dry ball mill may be either a closed type or an open type, but when the closed type is adopted, it is preferable to fill the mill with an inert gas such as nitrogen gas before use.

Further, in this ball mill, the used balls 3
The surface temperature of 90 ° C to 120 ° C,
The crushing / grinding process and the drying process of the crushed raw material material are performed so that the room temperature of the mill body 1 does not exceed 80 ° C. Here, regarding the temperature control of the balls 3 to be used, the capacity of the mill main body 1, the amount of the balls 3 charged into the mill main body 1, the material and size of the balls 3, and the charging temperature and amount of the charged pulverized material, It is performed by adjusting the stirring speed and the cooling amount by the cooling jacket 2 provided on the peripheral surface of the mill body 1 based on the water content. Although the surface temperature of the ball 3 varies depending on the target material, for example, in the case of wood powder, it is preferable to set it in the range of 100 ° C to 120 ° C from the viewpoint of the efficiency of crushing and grinding. However,
When crushing / grinding requires a long time, it is preferably 90 ° C. to 100 ° C. from the viewpoint of preventing explosion. Further, when there is a risk of a burst explosion during crushing / grinding, it is preferable to keep the oxygen concentration in the mill body 1 within 15%,
In that case, for example, a method of continuously supplying nitrogen gas into the ball mill may be adopted.

According to the crushing / grinding process by such a ball mill, the internal temperature of the mill body 1 rises due to the frictional heat generated by the rotation of the balls 3, while the cooling water circulated in the cooling jacket 2 causes the mill to cool. By adjusting the temperature inside the main body 1 and the surface temperature of the balls 3 within the above-mentioned ranges, the raw material pulverized product is pulverized and simultaneously dried under a strong heating condition, whereby the desired particle size is obtained. The water content is adjusted to a range of, for example, 100 μm or less, and the water content is adjusted to 2.0% by weight or less. Further, according to this treatment, the balls 3 come into contact with the raw material pulverized product charged in a coarse powder state, so that the surface of the raw material pulverized product that comes into contact with the balls 3 is ground and broken. The breaking and grinding are efficiently performed.

That is, when the raw material pulverized product comes into contact with the surface of the ball 3, it is mechanically crushed and abraded to be pulverized and crushed.
Since it is ground and heated and dried at the same time, the water content is efficiently removed. Moreover, since the fibers in the pulverized raw material are subjected to expansion and contraction by being repeatedly subjected to heating and cooling, they are rapidly dried when they are separated from the balls 3, so that the tips of the fibers are The parts are efficiently ground by the balls 3, and as a result, ground cellulosic fine powder particles having an independent particle shape with less cilia on the peripheral surface can be obtained.
Then, the cellulosic fine powder particles thus obtained are classified to have a particle size in a desired range (for example, 1 to 10 μm, 1
0 to 20 μm, 20 to 50 μm, 50 to 100 μm) and the cellulose-based fine powder particles of the present invention for supporting the white inorganic pigment in a bite state.

Titanium oxide, lithopone, white carbon, calcium carbonate and the like can be used as the white inorganic pigment to be supported, but titanium oxide is particularly preferable in order to impart sufficient whiteness to the obtained molded product. . Further, the particle size of the white inorganic pigment is adjusted to be sufficiently smaller than that of the cellulose fine powder particles. Also,
As a method of supporting the white inorganic pigment on the cellulosic fine particles, for example, a machine mainly composed of an impact force while mixing the cellulosic fine particles and a white pigment and dispersing the obtained mixed particles in a gas phase. A method is employed in which specific thermal energy is applied to the particles, the cellulose-based fine powder particles are used as mother particles, and the pigment particles are supported on the peripheral surface of the mother particles.
That is, this method utilizes the fact that the pigment particles are harder than the cellulose-based fine particles, and the pigment particles are bitten (or embedded) into the surface of the cellulose-based fine particles due to the difference in hardness. ) It can be carried in the state of being.

As another method, mixed particles of cellulosic fine powder particles and white pigment are put into a ball mill as shown in FIG. 3 and subjected to grinding treatment again to give white inorganic particles on the peripheral surface of the cellulose fine powder particles. A method of supporting pigment particles can also be adopted. By carrying out such a carrying treatment, the white inorganic pigment particles 10 are carried in a state of being bitten on the peripheral surface of the cellulosic fine powder particles 11 as shown in FIG. As the amount of the white inorganic pigment to be carried, the upper limit is the amount that overlaps the peripheral surface of the cellulosic fine powder particles that are the mother particles and covers the peripheral surface, but the lower limit is the desired amount of the wood-like molded body. It is appropriately determined according to the whiteness and the like.

The pigment-supporting cellulose-based fine powder particles thus obtained have a color tone almost the same as the color tone of the white inorganic pigment, and the agglomeration of the supported fine powder particles occurs both during the production process and during the storage process. I was not able to admit. Then, the pigment-supporting cellulose-based fine powder particles are mixed with PP such as pellets, and molded into a desired interior material shape by extrusion or injection molding at a temperature of about 200 to 240 ° C., thereby providing a woody appearance. A molded body is obtained. Here, the compounding amount of the supported fine powder particles with respect to PP varies depending on the use of the obtained interior material, but from the experimental results described later, the supported fine powder particles are 10 parts by weight per 100 parts by weight of PP.
To about 70 parts by weight, preferably about 30 to 70 parts by weight.

In the wood-like molded product molded in this manner, the surface is sufficiently white due to the white pigment on which the surface is supported, and the cellulose-based fine powder particles supporting the pigment are ground. Since it has been treated, unlike the conventional wood crushed directly into fine powder, which is fibrous,
The surface of the molded material has a small amount of cilia and is granular, so that the surface of the molded material is free of fluff and has a good texture. In addition, since the cellulose-based fine powder particles are not fibrous but are granular, when fibrous substances are mixed and dispersed, the fibrous parts are entangled to form a dumpling or a cotton-like product. As a result, the pigment-carrying fine particles themselves have extremely good dispersibility with respect to PP.
Therefore, the obtained molding material also has a sufficiently uniform material.

Further, since the cellulose-based fine powder particles are not fibrous but have a granular shape, expansion and contraction caused by adsorbing or releasing water (including moisture) and solvent like conventional fibrous wood powder. Is extremely small, and thus the wood-like molding material containing the same is excellent in dimensional stability even though PP itself is inferior in dimensional stability. Further, since the cellulose-based fine powder particles supporting the pigment on the surface are used as the aggregate, the pigment covers the surface of the fine powder particles, so that the adsorption and suction of the resin by the fine powder particles is extremely reduced, and thus the molding distortion occurs. Is almost gone.

Further, in this molded product, since the cellulose-based fine powder particles carry the pigment, the heat resistance is improved as compared with that before the loading, so that the cellulose-based fine powder particles such as wood powder are simply added to the PP. As compared with the case of blending with and molding, the heat influence at the time of molding is small, and thus the change in color such as yellowing and the change in shape are suppressed. Further, the surface of the cellulose-based fine powder particles is covered by supporting the pigment, thereby suppressing the release of glycine and formic acid contained in the fine powder particles at the time of molding. Molding defects due to release are prevented. Further, in this molded product, the surface area of the cellulose-based fine powder particles is larger than that of the conventional wood powder due to the fact that the pigment is supported, and therefore, the adhesion between the fine powder particles and the resin in the molded product. The degree increases. Further, at the time of molding as well, compared with the conventional wood powder-containing resin, the cellulose-based fine powder particle-containing PP resin of the present invention is excellent in its fluidity, so that the extrusion molding pressure and the injection pressure can be set low.

Next, the surface to be coated of the molded body thus obtained is subjected to a grinding treatment with a brush or baffle to make it rough, and a part of the surface resin is removed. Then, by such a grinding treatment, unnecessary irregularities generated during the molding are smoothed and many fine scratches are formed in the molded body. The main purpose of this step is to eliminate the surface gloss, but if you use a brush with uneven edges,
The surface is roughened, and unevenness in color can be produced by coloring by applying a paint, which will be described later. As a result, the texture of wood can be further enhanced, and the penetration of the paint can be improved.

Further, in this case, as shown in FIG. 5, the pigment-carrying cellulose-based fine powder particles located on the surface by grinding the surface of the pigment-carrying white inorganic pigment 10 ...
And part of the cellulosic fine particles 11 is peeled off, and as a result, the inside of the cellulosic fine particles 11 is exposed and the molded body 12 is exposed.
Enhances the wood texture of the surface. In addition, such a grinding process causes unevenness in the whiteness of the surface, and when applying the paint to be described later, microscopically, there is a slight difference in the degree of suction of the paint and the degree of its paste. The wood-like molded product gives a further woody feel. Next, the surface to be painted that has been ground is subjected to decoration processing by embossing. This embossing process inserts a resin molding between the punch and the die to form a wood grain-like uneven pattern, or rolls the resin molding between embossing rolls to continuously form a wood grain like uneven pattern. Is the way to do it.

Then, a paint is applied to the embossed surface to make the wood grain pattern clear, and the excess paint on the coated surface is wiped off by a roll around which a nonwoven fabric or the like is wound. Here, as for the coating of the paint, a conventionally known coating method such as a spray gun spraying method or various fluidized dipping methods can be adopted. Further, as the paint used here, almost any one used in the paint as a resin component can be used, and among them, urethane resin, acrylic resin, melamine resin, polyester resin and the like are preferably used. Further, as the pigment, in order to give a woody appearance, for example, a brown pigment such as iron oxide or a black pigment such as carbon is used, and these pigments are blended in a state of being supported on the attrition-treated cellulosic fine particles and used. To be Here, as shown in FIG. 6, it is preferable to use, as the grinding-treated cellulosic fine particles 13, those having a particle size of about 1 to 15 μm, and as an inorganic pigment (not shown) carried thereon. Is sufficiently smaller than the above-mentioned cellulose-based fine particles.

The amount of such inorganic pigment-carrying cellulose-based fine particles to be mixed with the resin is 100 parts by weight of the resin in order to increase the strength of the coating film 14 to be obtained and to obtain particularly high abrasion resistance. On the other hand, it is desirable that the amount is 100 to 400 parts by weight. This is because when the amount is less than 100 parts by weight, sufficient improvement in abrasion resistance is not observed in the coating film obtained as compared with the conventional paint, and when the amount exceeds 400 parts by weight, the amount of the resin becomes relatively small, so that the coating material of the paint is applied. This is because the degree of coating on the kimono is reduced. Here, in general,
For example, when the conventional fibrous wood flour W as shown in FIG. 7 is blended, the blending amount is about 30 to 50 parts by weight, and if it is blended more than that, the wood flour W is cured due to sucking the resin. Although there is a problem that the coating film is cracked at that time, since the inorganic pigment-carrying cellulose-based fine powder particles 13 of the present invention shown in FIG. 6 carry an inorganic pigment on the surface thereof,
The suction of the resin by the fine powder particles is suppressed, and as a result, the coating film 14 obtained even with the above-mentioned blending amount does not suffer from inconvenience such as cracking. The cellulosic fine particles are ground and the inorganic pigment is carried in the same manner as the above-mentioned method. The interior surface material 15 for a vehicle of the present invention is obtained by subjecting the coated surface formed by applying such a coating material to a known topcoat treatment.

The vehicle interior material 15 thus obtained
In that case, since the surface of the molded body 12 was subjected to grinding treatment,
The white inorganic pigment-carrying cellulosic fine particles 11 located facing the outer surface on the grinding surface have their pigment-carrying portions shaved so that the inner surface of the cellulose fine powder particles faces the grinding surface. It is soft and has a rich wood texture due to the fact that the cellulose fine particles themselves are hygroscopic. In addition, the coating is applied to the grinding-treated surface facing the inner surface of the cellulose fine powder particles, whereby the coating material is directly sucked into the cellulosic fine powder particles, which improves the suction and paste of the coating material to the molded body. .

Further, since the finely powdered cellulose is blended in the molded body 12, the coating of the coating material on the molded body becomes firm, and the vehicle interior has a sufficiently homogeneous coating film 14 without partial peeling. It becomes the material 15. Further, as the coating material, one having a good dispersion of cellulose-based fine powder particles is used, and since the inorganic powder is carried on the fine powder particles, the dispersibility of the pigment itself in the coating material is very good, and therefore The obtained coated surface does not have unnatural color unevenness and has a woody appearance with only a natural change in color tone due to embossing or the like.

Further, since the finely ground cellulosic particles are blended as the paint, unlike the conventional matte surface by silica or the like, there is no reduction in white turbidity and there is a color tone specific to the pigment used in the paint. And a matte colored surface is obtained. That is, such a good matte surface can be obtained by the coating film 1 on the surface of the molded body 12 as shown in FIG.
4, the cellulose fine particles 13 are uniformly arranged, and after the coating film is formed, the cellulose fine particles 13 do not shrink in the surface layer of the coating film, but the resin component between them does shrink slightly, so that minute irregularities are formed on the surface. This is because the depth reflection is suppressed, and the entire surface is frosted.

(Production Example) Wood powder having a particle size of 30 μm to 100 μm and an average particle size of 50 μm obtained by grinding by the ball mill method was prepared. Oxidation having an average particle size of 5 μm was performed as a white inorganic pigment. Supported titanium. As the supporting method, the re-grinding treatment method by the ball mill described above was used. Next, the supported fine powder particles obtained were mixed with P-shaped pellets.
10, 15, 20, 30, 50, based on 100 parts by weight of P
70 parts by weight of each of them, and also known additives as additives are mixed and mixed, and the resulting 6 kinds of mixtures are extrusion-molded to obtain a width of 60 mm, a thickness of 7 mm, and a length of 10 m.
6 kinds of plate materials were obtained.

The 6 types of plate materials thus obtained were visually observed and further examined for touch, and it was confirmed that all of them had a uniform whiteness and the surface was soft and non-sticky. Further, one surface of each of these plate materials and a side end surface in the lengthwise direction were subjected to a grinding treatment with a buff roll to make the treated surface rough. Next, the ground surface was further embossed with a punch and a die to form a grain-like uneven pattern.

Then, a general paint prepared in advance is applied to the embossed surface of the plate material with a spray gun to clarify the grain pattern, and the surplus paint on the coated surface is removed by a roll wound with a non-woven fabric or the like. I wiped it off. further,
Urethane-based and acrylic-based coatings were applied to the coated surface with a spray gun, a flow coater or the like to perform a topcoat treatment and cut into a length of 5 m to obtain 6 types of plate bodies. The obtained 6 kinds of plates had a clear wood grain pattern and moderate color unevenness, and because they were matt, they had a surface layer very close to that of natural wood. In addition, since the coated surface was soft to the touch and there was no stickiness, it had a sufficient wooden texture.

(Experimental Example) The six types of plate materials before grinding treatment obtained in the above Production Example were cut into a predetermined size to prepare a test piece, and various physical properties were examined. The results are shown in Table 1. For comparison, PP-only test pieces to which wood flour was not added were prepared under the same conditions as the above-mentioned 6 kinds of test pieces, and their various physical properties were also examined. The results are also shown in Table 1.

[Table 1]

As can be seen from Table 1, the products of the present invention to which the supported wood powder is added are superior in bending strength and flexural modulus to those composed of PP alone, and therefore, when formed into an interior material for a vehicle, they are resistant to bending. It has excellent strength. Further, as the amount of supported wood powder increases, the heat deformation temperature becomes higher, and therefore the heat deformation at the time of molding etc. is reduced as compared with the case of only PP. Further, since the coefficient of linear expansion becomes small, the dimensional stability becomes excellent as compared with the case of using only PP.

[0037]

Industrial Applicability As described above, the interior material for a vehicle of the present invention is obtained by directly grinding conventional wood because the pigment-containing cellulosic fine particles contained in the molded body are ground. Unlike the fibrous material that is pulverized into fine powder, the surface has a small amount of cilia and is granular, so even after applying a paint, the interior material surface is not fluffy, feels good on the skin, and is rich in wood texture. Will be things. And, as a result, this interior material has a sufficiently natural appearance and a woody appearance comparable to that of natural wood products.
It will give the car a feeling of luxury and calmness due to the handmade feel. In addition, since the cellulose-based fine powder particles in the molded product are not fibrous but granular, expansion and contraction caused by adsorbing or releasing water (including moisture) like conventional fibrous wood powder Very few, therefore, the molded product containing this is not affected by moisture permeation from the back side that is not painted like the interior material for vehicles made of wood, and therefore deformation caused by moisture permeation is prevented. Becomes Further, since the molded body is made of the cellulose-based fine powder particles which have been subjected to the grinding treatment and the pigment is carried on the surface thereof as the aggregate, the adsorption and suction of the resin by the fine powder particles is extremely reduced and the molding distortion may occur. The interior material thus obtained has almost no dimensional accuracy. Furthermore, when fibrous wood powder (fine cellulose particles) that has not been subjected to conventional grinding treatment is incorporated into a resin as an aggregate, the effect of a treatment agent for alkali neutralizing the wood powder is Therefore, it becomes yellowish and further becomes a brown molding material, and molding distortion occurs due to sucking resin, but in the present invention, a cellulose-based fine powder particle that simply carries a white inorganic pigment and is not subjected to alkali treatment is used. Since it is used, discoloration does not occur, and since the cellulose-based fine powder particles are not fibrous but granular, expansion and contraction is extremely small.Therefore, the polypropylene resin itself is inferior in dimensional stability in the molded product containing this. However, it has excellent dimensional stability.

Further, in this interior material, since the molded body was ground, the white inorganic pigment-carrying cellulosic fine particles located facing the outer surface on the grinding surface were scraped at the pigment-carrying portion. By exposing the inner surface of the cellulose fine powder particles to the surface to be ground, the surface of the molded article becomes rich in wood texture. Then, the coating is applied to the grinding-treated surface facing the inner surface of the cellulose fine powder particles, so that the coating material is directly sucked into the cellulose fine powder particles, whereby the paste of the coating material to the molded article becomes good, and It was difficult to coat the interior material made of polypropylene resin, whereas the interior material of the present invention can be easily coated. Further, since the cellulose-based fine powder particles blended in the paint are not fibrous but in the form of particles, the dispersibility of the fine powder particles themselves in the paint is extremely good, and the resulting coating film is sufficiently homogeneous. And that the variation in the adhesive force of the coating material to the panel-shaped molded article is eliminated, and further because the fine powder particles carry an inorganic pigment, the heat resistance is also improved.
The interior material of the present invention is superior in weather resistance and durability to the conventional wood interior materials and interior materials made of resin-integrated molded products. Further, since the polypropylene resin having good moldability is used as the resin material, the moldability of the molding material itself is improved, and therefore, it is possible to cope with a relatively complicated shape within the range where extrusion or injection molding is possible. Moreover, since the cost of the polypropylene resin itself is low, the manufacturing cost of the molding material can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an instrument panel.

FIG. 2 is a perspective view of a floor console.

FIG. 3 is a fragmentary front view of an open type ball mill.

FIG. 4 is a cross-sectional view showing a state in which a white inorganic pigment of cellulose fine powder particles used in the present invention is carried.

FIG. 5 is an enlarged view of a surface layer portion of a molded body that has been subjected to a grinding process.

FIG. 6 is an enlarged view of a surface layer portion of a molded body showing a state in which a coating material containing fine cellulose particles is applied to the cutting surface of the molding material.

FIG. 7 is an enlarged view showing conventional wood flour obtained by directly pulverizing wood into fine powder.

[Explanation of symbols]

 1 Mill Main Body 3 Ball 10 White Inorganic Pigment Particle 11 Cellulose Fine Particle 12 Molded Product 13 Cellulose Fine Particle 14 Coating Film 15 Interior Material for Vehicle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29L 31:58

Claims (1)

[Claims] 1. A finely divided cellulose-based powder in which a white inorganic pigment is carried in a state of being crushed on a surface thereof and mixed with a polypropylene resin, and the mixture is molded by extrusion or injection molding, and the molding is further performed. An interior material for a vehicle, wherein a surface to be coated of a body is subjected to a grinding treatment, and a coating is applied to the grinding surface.