JPH10225977A - Resin moldings and manufacturing thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the improvement of workability and the reduction of cost and at the same time, inhibit the worsening of a visual quality when manufacturing resin moldings. SOLUTION: A year spoiler 11 is of a hollow form and is structured of three layers such as an outer layer part 12, an inner layer part 13 and an innermost layer part 14. The outer layer part 12 and the inner layer part 13 are made of high crystalline polypropylene, and the outer layer part 12 is colorless and transparent, while the inner layer part 13 is previously colored in an earlier molding stage. The innermost layer 14 is constructed of polypropylene including a filler, and the rear spoiler 11 is manufactured by a blow molding method. The colored part of the inner layer part 13 is easily recognized visually without depending upon a polishing step and a coating step. When performing a blow- molding process, an unevenness on the surface of the outer layer part 12, if any is hardly conspicuous as the outer layer part 12 is transparent. In addition, the outer layer part 12, if exposed to light, does not receive color degradation easily. Consequently, the outstanding visual quality can be maintained for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded product and a method of manufacturing the same, and more particularly, to a resin molded product formed by blow molding, such as an automobile spoiler, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, hollow resin products such as automobile spoilers have been obtained by a molding method called a blow molding method. In this molding method, a cylindrical body (parison) in which a resin material is softened is dropped into a mold, high-pressure gas is blown into the parison, and the parison is transferred to a molding surface of the mold, and the molded article is formed. Then, the molded article is taken out of the mold.

[0003] Generally, the molded article contains a filler for securing rigidity therein and the transfer rate to a mold is not so good. Is applied. Then, in order to ensure the appearance quality of the product, a clear coating is further applied after a coating process.

As described above, conventionally, after molding,
A polishing process for eliminating irregularities is required, and two or more coating steps are required, resulting in an increase in the number of working steps and, consequently, an increase in cost.

On the other hand, it is conceivable that the parison has a two-layer structure in order to omit the coating step. That is, the parison, an inner layer made of a resin material mixed with a filler,
An outer layer made of a colored resin material is used, and blow molding is performed using such a parison.

[0006]

However, the above technique has the following problems. First, since the filler is not mixed into the outer layer, the unevenness due to the filler can be eliminated, but the unevenness still exists on the outer layer surface due to the poor transfer rate during blow molding. For this reason, there was a possibility that the appearance quality would be inferior.

Second, the outer layer is made of a colored resin material. However, when the product is exposed to sunlight or the like, there is a possibility that the molded product may be discolored due to weather resistance. Therefore, there was a possibility that the appearance quality would deteriorate over time.

Third, it is conceivable to mix an agent for improving weather resistance into the outer layer. However, in this case, color spots may occur due to the mixing of the drug, and the appearance quality may be poor immediately after molding.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to improve workability and reduce costs in manufacturing and to suppress deterioration in appearance quality. And a method of manufacturing the same.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: an outer layer made of a resin material; and an inner layer made of a resin material compatible with the outer layer. Is a resin molded product molded by blow molding method, the outer layer portion, while comprising a transparent or translucent resin subjected to a weather resistance improving prescription,
The gist is that the inner layer portion is made of a colored resin.

In the invention according to claim 2, in the resin molded article according to claim 1, an innermost layer portion made of a resin material mixed with a filler is further provided inside the inner layer portion. The main point is that

Further, in the invention according to claim 3, in the resin molded product according to claim 1 or 2, the gist is that the resin material constituting the outer layer portion is made of highly crystalline polypropylene.

[0013] In addition, according to the invention described in claim 4, in the resin molded product according to any one of claims 1 to 3, it is specified that the weather resistance improving prescription includes an ultraviolet absorber. It is a gist.

Further, in the invention according to claim 5, an outer layer parison made of a transparent or translucent resin material, and a resin which is compatible with the outer layer parison and is colored Dropping a parison comprising an inner parison made of a material into a mold having a number of through holes for deaeration, and blowing high-pressure gas into the inner parison while the mold is clamped. Transferring the parison to the molding surface of the mold, and after solidifying the parison to form a molded article, removing the molded article from the mold. It is a gist.

[0015] In addition, according to the invention described in claim 6, in the method for producing a resin molded product according to claim 5, the parison is formed of a resin material mixed with a filler inside the inner layer parison. The gist is to have an innermost parison.

According to a seventh aspect of the present invention, in the method for manufacturing a resin molded product according to the fifth or sixth aspect, the diameter of the through hole is preferably 0.01 mm or more and 0.1 mm or less. It is a gist.

Further, in the invention according to claim 8, in the method for producing a resin molded product according to any one of claims 5 to 7, the resin material constituting the outer layer parison is a highly crystalline polypropylene, The gist is that the temperature of the mold in the transfer step is 115 ° C. or more and 160 ° C. or less.

According to the first aspect of the present invention, the resin molded article formed by the blow molding method comprises an outer layer made of a resin material and a resin material compatible with the outer layer. And an inner layer. The inner layer is
Since the outer layer portion is made of a transparent or translucent resin, the colored portion of the inner layer portion can be easily visually recognized. Further, during blow molding, there is a concern that transfer to a mold may be deteriorated. However, even if irregularities are present on the surface of the outer layer portion, it is inconspicuous because the outer layer portion is transparent or translucent.

Further, the outer layer is provided with a weather resistance improving prescription, the transparency is not impaired, and the inner layer is hardly affected by ultraviolet rays and heat, and does not easily discolor. According to the second aspect of the invention, in addition to the function of the first aspect, an innermost layer portion made of a resin material mixed with a filler is further provided inside the inner layer portion. ing. Therefore, the rigidity of the molded product itself is ensured.

Further, according to the third aspect of the present invention,
In addition to the effects of the invention described in claims 1 and 2, the resin material forming the outer layer portion is made of highly crystalline polypropylene. For this reason, while blow molding is easily performed,
Transparency of the outer layer portion can be ensured.

In addition, according to the invention described in claim 4,
In addition to the effect of the invention according to any one of claims 1 to 3, since an ultraviolet absorber is contained as a weather resistance improving formulation, the inner layer portion is not particularly affected by ultraviolet rays.

According to the fifth aspect of the present invention, an outer layer parison made of a transparent or translucent resin material, a weather resistant improving formulation is applied, and the outer layer parison is compatible and colored. A parison composed of an inner layer parison made of a resin material is suspended in a mold having a large number of through holes for deaeration. Next, while the mold is clamped, high-pressure gas is blown into the inner layer parison, and the parison is transferred to the molding surface of the mold. Then, after the parison is solidified into a molded product, the molded product is removed from the mold. Therefore, a molded article having the effect of the invention of the first aspect can be easily obtained.

Further, according to the present invention, since the mold has a large number of holes for deaeration, degassing from the holes allows the parison to be more easily transferred to the molding surface. Therefore, the surface of the outer layer portion of the molded product becomes smoother.

Further, according to the invention described in claim 6,
In addition to the effect of the invention described in claim 5, the parison further has an innermost parison made of a resin material mixed with a filler inside the inner parison. For this reason, the rigidity of the obtained molded product itself is ensured, similarly to the second aspect of the invention.

According to the seventh aspect of the present invention, in addition to the effects of the fifth and sixth aspects, the diameter of the through hole is 0.01 mm or more and 0.1 mm or less. At the time of molding, the parison does not enter into the through-hole, so that it is possible to prevent the molded article from having irregularities.

Further, according to the invention described in claim 8,
In addition to the effect of the invention according to claims 5 to 7, the resin material constituting the outer layer parison is a highly crystalline polypropylene, and the temperature of the mold in the transfer step is 115 ° C or higher and 160 ° C or lower. It is. Therefore, blow molding can be easily performed, and transparency of the outer layer portion can be ensured. Further, it is possible to avoid the occurrence of uneven gloss due to too low a temperature and the difficulty in molding due to too high a temperature.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment embodying a resin molded product and a method of manufacturing the same according to the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, the rear spoiler 11 as a resin molded product is a kind of exterior product disposed at the rear of an automobile, and is formed in a hollow shape. The rear spoiler 11 has a three-layer structure including an outer layer portion 12, an inner layer portion 13, and an innermost layer portion 14 provided further inside the inner layer portion 13.

The outer layer portion 12 is made of highly crystalline polypropylene (having a degree of crystallinity of 70% or more) and is colorless, transparent or translucent. The thickness is "1.0mm"
「About“ 1.5 mm ”. Further, the outer layer 1
In No. 2, an ultraviolet absorber is mixed as a weather resistance improving formulation.

The inner layer 13 is provided in a state of being joined to the inner surface of the outer layer 12, and is also made of highly crystalline polypropylene. The inner layer portion 13 is colored (material coloring) in advance from the stage before molding, and has a thickness of about 2.0 mm to 3.0 mm.

The innermost layer portion 14 is provided in a state joined to the inner side surface of the inner layer portion 13 and is made of polypropylene mixed with a filler. Further, its thickness is about "2.0 mm" to "3.0 mm".

The rear spoiler 11 configured as described above is manufactured by a so-called blow molding method.
FIG. 3 is a cross-sectional view schematically showing a mold device used for blow molding. The mold device includes a first mold 21 and a second mold 22, and has molding surfaces 23 and 24, respectively. In the present embodiment, a so-called porous electroforming mold is used as the first mold 21 and the second mold 22.

Each of the molds 21 and 22 has a molding surface 2
A large number of through-holes 25, 26 opening to 3, 3 are formed. The diameter of these through holes 25 and 26 is “0.01 m
m ”to“ 0.1 mm ”, which are extremely small. In addition, the molds 21 and 22 are formed with degassable holes 27 and 28 communicating with the respective through holes 25 and 26.

In order to form the rear spoiler 11 using the above-described mold apparatus, first, as shown in FIG. 4, with the first mold 21 and the second mold 22 opened,
The parison 31 in a softened state is hung from a die (not shown). The parison 31 includes the outer layer 12 described above,
In order to form the inner layer portion 13 and the innermost layer portion 14, the outer layer parison 32, the inner layer parison 33, and the innermost layer parison 34 corresponding to the inner layer portion 13 and the innermost layer portion 34 are formed to have a cylindrical shape. At this time, the temperature of the mold apparatus is 115 ° C. or higher and 1
It is set to 60 ° C. or lower.

Then, as shown in FIG.
While closing the first and second molds 22, in that state,
High-pressure air is blown (blowed) from the inside of the parison 31 to expand the parison 31. Then, the parison 31 moves the first and second molds 2 by the pressure of air.
The first and second molding surfaces 23 and 24 come into contact with each other and are transferred.

At this time, air is evacuated from the deaeration holes 27 and 28 to form the molding surfaces 23 and 24 and the parison 3.
As a result, the air in the space 1 is removed, and the parison 31 comes into contact with the molding surfaces 23 and 24 more strongly.
Therefore, transferability is improved.

Thereafter, the mold apparatus is cooled, the parison 31 is cooled and solidified, and finally the first and second molds 2 are cooled.
Open the molds 1 and 22 and take out the molded product. Thereby, the rear spoiler 11 having the above configuration is obtained.

Next, the operation and effect of this embodiment will be described. In the present embodiment, the rear spoiler 11 formed by the blow molding method has an outer layer portion 12 made of transparent polypropylene and an inner layer portion 13 colored with a material. Therefore, the colored portion of the inner layer portion 13 can be easily visually recognized without going through the polishing step and the painting step. As a result, workability can be dramatically improved.

Also, when performing blow molding, the molding surfaces 23,
There is a concern that the transfer to the transfer layer 24 may be deteriorated. However, even if there are irregularities on the surface of the outer layer portion 12, the unevenness is less noticeable because the outer layer portion 12 is transparent. Therefore, it is possible to prevent the appearance quality from being degraded. Further, since the outer layer portion 12 contains an ultraviolet absorber, even if it is irradiated with light, it does not easily fade. As a result, excellent appearance quality can be maintained for a long time. Further, since the ultraviolet absorber is mixed in a layer different from the colorant, it is possible to prevent the occurrence of color unevenness due to the mixing of the ultraviolet absorber and the colorant.

At the same time, an innermost layer portion 14 made of a polypropylene resin material mixed with a filler is provided inside the inner layer portion 13. Therefore, the rigidity of the rear spoiler 11 itself can be secured. Further, since the filler is mixed into the innermost layer portion 14 instead of the outer layer portion 12, it is possible to prevent the filler from being uneven on the surface of the product.

In addition, the resin material constituting the outer layer portion 12 is made of highly crystalline polypropylene. Therefore, blow molding can be easily performed, and transparency of the outer layer portion 12 can be ensured.

According to the manufacturing method of the present embodiment, the rear spoiler 11 having the above-mentioned effects can be easily obtained, and the first and second molds 21 and
22 has a large number of through holes 25 and 26 for deaeration.
Is more reliably transferred to the molding surfaces 23 and 24. Therefore, the surface of the outer layer portion 12 of the rear spoiler 11 can be made smoother.

Further, the diameters of the through holes 25 and 26 are as follows:
Since it is very small, that is, not less than “0.01 mm” and not more than “0.1 mm”, the parison 31 does not enter the through holes 25 and 26 at the time of molding, so that the surface of the rear spoiler 11 The occurrence of unevenness corresponding to the holes 25 and 26 can be prevented.

And the two dies 2 in the transfer step.
The temperatures 1 and 22 are 115 ° C. or more and 160 ° C. or less. Therefore, it is possible to avoid the occurrence of uneven gloss due to too low a temperature and the difficulty in molding due to too high a temperature.

(Second Embodiment) Next, a second embodiment of the present invention will be described. However, in the basic configuration and the like of the present embodiment, a detailed description of portions and the like that are the same as those in the above-described first embodiment will be omitted. The following description focuses on the differences from the first embodiment.

As shown in FIGS. 6 and 7, in the present embodiment, instead of the rear spoiler 11 of the first embodiment,
The present invention is embodied in a side molding 41. Side molding 41 as resin molded product in the present embodiment
Has a long shape and is attached to a door panel or the like of an automobile, and has a hollow shape.

The side molding 41 has a two-layer structure including an outer layer 42 and an inner layer 43. That is,
This embodiment is different from the first embodiment in that the present embodiment does not have a layer in which a filler is mixed. Outer layer part 42
Is made of highly crystalline polypropylene containing an ultraviolet absorber and is colorless, transparent or translucent, as in the first embodiment. The inner layer 43 is provided in a state of being joined to the inner surface of the outer layer 42 and is made of polypropylene. The inner layer 43 is also colored in advance from the stage before molding.

The side molding 41 constructed as described above is also manufactured by the same blow molding method as described above. Also in the present embodiment, the same operation and effect as those of the above-described first embodiment are exerted except that the innermost layer portion in which the filler is mixed is not provided.

The embodiment is not limited to the above, but may be modified as follows. (1) In each of the above embodiments, the present invention is embodied in the rear spoiler 11 and the side molding 41 as a resin molded product. However, the present invention can be embodied in other molded products as long as it is hollow. Examples of other molded articles include exterior parts for automobiles such as side spoilers and bumpers, and interior parts for automobiles such as a center console lid.

(2) In the above embodiments, polypropylene was used as the resin material. However, any other material (for example, polyethylene, PET, PBT, polyamide, polystyrene, AB) may be used as long as it is a thermoplastic resin material.
S etc.) may be used.

(3) In the above embodiment, an ultraviolet absorber is contained as a weather resistance improving prescription, but in addition, an antioxidant, a light stabilizer and the like may be contained.

[0052]

As described in detail above, according to the resin molded product and the method of manufacturing the same according to the present invention, it is possible to improve the workability and reduce the cost in manufacturing and suppress the deterioration of the appearance quality. The effect is excellent.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2, showing a rear spoiler according to a first embodiment.

FIG. 2 is a perspective view showing a rear spoiler.

FIG. 3 is a cross-sectional view schematically showing a mold device used for blow molding.

FIG. 4 is a sectional view showing a state where a parison is hung down.

FIG. 5 is a cross-sectional view of a mold device and the like showing an operation during blow molding.

FIG. 6 is a perspective view showing a side molding according to the second embodiment.

FIG. 7 is a sectional view of a side molding.

[Explanation of symbols]

11. Rear spoiler as a resin molded product, 12, 42
... Outer layer portion, 13, 43 ... Inner layer portion, 14 ... Innermost layer portion, 21
.. A first mold, 22 a first mold, 23, 24 a molding surface, 25, a through hole, a 31 parison, a 32 inner parison, a 33 outer parison, a 34 innermost parison.
41: Side molding as a resin molded product.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 23:00 B29L 9:00 22:00 31:30

Claims (8)

[Claims] 1. A resin molded article formed by a blow molding method, comprising: an outer layer portion made of a resin material; and an inner layer portion made of a resin material compatible with the outer layer portion. A resin molded article comprising a transparent or translucent resin subjected to a weather resistance improving prescription, and wherein the inner layer portion is composed of a colored resin. 2. The resin molded product according to claim 1, wherein an innermost layer portion made of a resin material mixed with a filler is further provided inside the inner layer portion. 3. The resin molded product according to claim 1, wherein the resin material constituting the outer layer portion is made of high crystalline polypropylene. 4. The resin molded article according to claim 1, wherein the weather resistance improving prescription contains an ultraviolet absorber. 5. A parison comprising a transparent or translucent resin material, which is provided with a weather resistance improving formula, and an inner parison, which is compatible with the outer layer parison and is made of a colored resin material. Dropping into a mold having a large number of through holes for deaeration, and, while the mold is clamped, blowing high-pressure gas into the inner layer parison, and moving the parison into the mold. A method for producing a resin molded article, comprising: a step of transferring to a molding surface; and a step of solidifying the parison to form a molded article, and then removing the molded article from a mold. 6. The resin molded article according to claim 5, wherein the parison further has an innermost parison formed of a resin material mixed with a filler inside the inner parison. Production method. 7. The hole diameter of the through hole is 0.01 mm or more and 0.1 mm or less.
3. The method for producing a resin molded product according to 1. 8. The resin material constituting the outer parison is a highly crystalline polypropylene, and the temperature of the mold in the transfer step is 115 ° C. or more and 160 ° C. or less. 8. The method for producing a resin molded product according to any one of items 1 to 7.