JP3031400B2 - Synthetic resin molded product and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article of a synthetic resin such as an exterior material for an automobile, which requires a high surface clarity, and a method for producing the same. Surface clarity is a measure of how sharp and undistorted the image is when projected onto the surface of automobile exterior materials, etc. This is an important property for exterior materials. Metallic exterior materials for automobiles are heavy and lack the degree of freedom of design, so that practical use of synthetic resin exterior materials is now awaited.

[0002]

2. Description of the Related Art If an automotive exterior material can be molded by injection molding using a synthetic resin, there is a possibility that the weight can be reduced and the degree of freedom in design can be increased. On the other hand, automotive exterior materials are generally required to have a coefficient of linear expansion of 5 × 10 ⁻⁵ / ° C. or less. Therefore, when a synthetic resin is used for the above purpose, a measure is usually taken to reduce the linear expansion by blending glass fibers. However, when a material containing glass fiber is injection-molded, the surface appearance is poor because the glass fiber floats on the surface. is there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a synthetic resin molded article such as an automobile exterior material having excellent surface clarity and less warpage, and a method for producing the same. is there.

[0004]

Means for Solving the Problems The inventors of the present invention have proposed a method of mounting a sheet in a mold cavity, injecting and injecting another thermoplastic resin, and integrally molding the sheet (hereinafter, may be referred to as CFI technique). The present inventors have found that the above problems can be solved by using a composite reinforced polycarbonate resin as a molding material, and have reached the present invention. That is, the present invention relates to a synthetic resin molded product obtained by an injection molding method, in which an aromatic polycarbonate sheet (A) is cut into a predetermined shape, mounted on one surface of a mold cavity, and then subjected to molding shrinkage [thickness].
Only 3.2mm, using an outer diameter 101.6mm disk mold
It is a molding shrinkage ratio when a molded product is obtained.
Obtained from (mold size-molded product size) / (mold size)
Is less than 0.3% in the direction parallel to the resin gate.
Composite reinforced polycarbonate molding material is less than 0.5% linear direction (B) was injected injected onto the sheet (A), a synthetic resin molding integrally laminated the sheet (A) with said molding material (B) The invention relates to the product (C).

The aromatic polycarbonate sheet (A) used in the present invention includes 2,2-bis (4-hydroxyphenyl) -propane and 2,2-bis (3,5-dibromo-4).
-Hydroxyphenyl) -propane is a polymer obtained by a known method from one or more divalent phenolic compounds exemplified by propane and a carbonate precursor exemplified by phosgene, and polyethylene terephthalate (PE
T), polyesters such as polybutylene terephthalate (PBT), styrene resins, and polymer alloys with polyamides and the like.

In the case of laminating the sheet (A) with a molding material using a molding material, if the curvature (H / D) of the product exceeds 0.1, the resin flowing on the sheet is used to form the product into a product shape. There is a problem that wrinkles occur because the ends cannot be drawn with resin. In such a case, preforming is preferably performed by vacuum forming or the like. For example, straight, drape, plug assist, and air blow molding methods can be applied. When the thickness of the sheet is preferably 0.3 mm or more, particularly preferably 0.3 to 3 mm, the appearance of the product at the time of lamination molding is not affected by glass fibers or glass flakes blended into the core material. The performance is improved. In addition, when the shape is imparted by the above-mentioned vacuum forming or the like, the shapeability is excellent. As the above-mentioned sheet, a sheet which has been previously subjected to a character mark by printing, painting or the like, or a sheet which has been subjected to a surface treatment such as a thermoformable hard coat can be used.

As the thermoplastic resin used in the composite reinforced polycarbonate molding material (B) used in the present invention, a thermoplastic resin which can be welded to the above-mentioned aromatic polycarbonate sheet (A) can be used. ,
Examples thereof include polycarbonate / polyester resin compositions, polycarbonate / styrene resin compositions, polycarbonate / polyamide resin compositions, and other polycarbonate resin compositions (polycarbonate alloys).

The reinforcing filler which can be used in the composite reinforced polycarbonate molding material (B) is one which is incorporated into a resin for the purpose of reducing mechanical strength, heat resistance, molding shrinkage or linear expansion coefficient. , in particular glass, carbon, metal, whiskers, silicon carbide, which has the above performance of fibrous or flaky like organic or inorganic substances such as boron Ru are used as appropriate. Glass fiber among the top Symbol filler is particularly desirable. The selection and the mixing ratio of the filler are determined in consideration of the mechanical strength and the following reduction in molding shrinkage or linear expansion coefficient.

When selecting the filler and selecting the compounding ratio based on the molding shrinkage, the molding shrinkage is calculated by using a disk mold having a thickness of 3.2 mm and an outer diameter of 101.6 mm using the formula 100 × (mold size−molding). The value obtained from (product size) / (mold size) is 0.3% or less in the direction parallel to the gate and 0.5% in the vertical direction.
% Is desirable. The molding shrinkage is measured, for example, when a polycarbonate containing bisphenol A as a main raw material is used as the composite reinforced polycarbonate molding material, at a temperature of 280 ° C. of the molten resin and a mold temperature of 80 ° C. When the above-mentioned molding shrinkage exceeds the above-mentioned value, each surface (sheet surface and material surface) of the laminated molded product
, There is a possibility that warping may occur over the entire surface of the molded product. In addition, when the selection of the filler and the mixing ratio are selected according to the coefficient of linear expansion, the coefficient of linear expansion is desirably 5 × 10 ⁻⁵ / ° C. or less. Here, the coefficient of linear expansion is a value measured according to ASTM D696. If the coefficient of linear expansion is equal to or greater than the above value, warping may occur over the entire surface of the molded product as described above.

As a composite reinforced polycarbonate molding material having excellent mechanical strength and satisfying the above-mentioned molding shrinkage or linear expansion coefficient, for example, glass fiber, glass flake, or a mixture thereof is used in an aromatic polycarbonate resin composition. Those containing 50% by weight are exemplified.
In general, a large amount of waste materials such as sprues and runners are generated in injection molding. However, in the present invention, as a part or all of the resin used in the composite reinforced polycarbonate (B), the waste material is pulverized, and glass fibers are used. Can also be used in a suitable amount. When the synthetic resin molded product obtained in the present invention is further subjected to a coating treatment, the molded product has better surface clarity. The coating can be usually performed by a spray method using a urethane paint, an acrylic paint or the like.

Known conditions can be applied to the injection conditions and the like of the present invention. The injection molding machine to be used can use a usual injection molding machine, and can manufacture a molded article by the following method. Hereinafter, the steps of the present invention will be exemplified. (1) Attaching the sheet to the mold To attach the aromatic polycarbonate sheet (A) to the mold, a plurality of pins are provided on the mold, and holes are formed at positions corresponding to those of the sheet. There is a method and a method in which a magnet is embedded in a mold, and an iron piece is attached to a position corresponding to that of a sheet and attached. The sheet (A) is desirably mounted on the fixed side of the mold cavity. (2) Clamping After mounting the sheet, the mold is clamped.

(3) Injection of molten resin The composite reinforced polycarbonate molding material (B) is injected and injected from an injection molding machine, and the sheet (A) and the molding material (B) are integrally laminated. (4) Cooling and release After the resin is injected, the molten resin is cooled and solidified according to a conventional method, and a molded product is obtained after release. (5) Coating When coating a molded product obtained for the exterior of an automobile or for a household appliance, the coating is performed by an ordinary method. By the above-mentioned molding, the sheet (A) and the molding material (B) are completely thermally welded by the heat and pressure during molding. The sheet surface had excellent appearance.

Although the manufacturing method and the mold structure of the present invention have been described above, the present invention is not limited to the above description. As a molding condition, the temperature of the molding material is 290.
By molding at a temperature of not less than ° C., the fluidity of the resin and the adhesive strength of the sheet can be increased. When using a printed sheet, the mold temperature is preferably equal to or lower than the heat resistant temperature of the ink. Further, according to the present invention, a product with good clarity in quality can be obtained, and since recycled materials can be used, cost reduction can be expected, and further, an environmental protection effect can be expected.

[0014]

The present invention will be described below in detail with reference to examples. In this example, the evaluation of the molded article was performed by the following method. Evaluation of sharpness When an object was transferred to the surface of a molded article, the image was visually observed and evaluated based on the degree of distortion. ：: There is no image distortion. X: The image is distorted. Measurement of adhesive strength between sheet and molding material A 90-degree peel strength between the sheet and the molding material was measured. The measurement was performed by peeling the sheet and the molding material from the side opposite to the gate of the molded product, and the 90-degree peel strength (kgf / c
m) was measured with a spring only. The evaluation was as follows. ：: 90 ° peel strength of 5 kgf / cm or more ×: 90 ° peel strength of less than 5 kgf / cm

Measurement of warpage Warpage was evaluated using a three-dimensional dimension measuring machine (manufactured by Mitoyo Seisakusho). Evaluated by the maximum height difference (△ h) of the molded product,
The indication was based on the following criteria. ：: The molded product has a warpage of 0.1 mm or less. X: The molded product has a warpage of more than 0.1 mm. Cooling / heat repetition test Adhesive strength, repetitive cooling / heating at −30 ° C. and 80 ° C. The test was repeated and the test was performed. That is, -3
The operation of heat-treating at 0 ° C. for 2 hours and 80 ° C. for 2 hours (a change time of 2 hours until each temperature was reached) was repeated 20 times, and then the adhesive strength and warpage were evaluated. .

Example 1 A polycarbonate resin sheet having a thickness of 0.5 mm (hereinafter referred to as a polycarbonate resin sheet)
A PC sheet) was punched out with a press machine in accordance with the dimensions of the mold mounting portion (a disk shape of 100 mmφ). The mold cavity is designed so that the thickness of the molded product is 3 mm. After mounting the sheet in the fixed side cavity of the mold, the mold is clamped, and a glass fiber-containing polycarbonate resin material (manufactured by Mitsubishi Gas Chemical Co., Ltd.,
Trade name: Iupilon GS-2010M, glass fiber content in the composition is 10% by weight, molding shrinkage is 0.3% in parallel direction, 0.5% in vertical direction, and coefficient of linear expansion is 5
× 10 ^-5 / ° C). The above molding conditions are as follows: resin temperature 300 ° C., mold temperature 70 ° C., injection pressure 1600 kgf.
/ Cm ² . Using a urethane paint for the molded article,
Each product was evaluated by spray coating. Table 1 shows the evaluation results.

Example 2 Glass fiber-containing polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Iupilon GS-2020M), the glass fiber content in the composition was 20% by weight, and the molding shrinkage was 0.1 in the parallel direction. %, And 0.4% in the vertical direction, and the coefficient of linear expansion was 4.4 × 10 ⁻⁵ / ° C.).
A molded article was manufactured in the same manner as described above and evaluated after painting. Table 1 shows the evaluation results.

Example 3 A molded product was manufactured in the same manner as in Example 2 except that a 0.3 mm polycarbonate sheet was used, and evaluation after coating was performed. Table 1 shows the evaluation results.

Comparative Example 1 Using the same polycarbonate resin material as used in Example 2, a non-laminated molded article was prepared without mounting a sheet under the same conditions as in the Example, and the sharpness was compared. went. Table 1 shows the evaluation results.

[0020]

[Table 1] Example 1 Example 2 Example 3 Comparative Example 1 Sharpness ○ ○ ○ × Before repeated thermal test 1) Adhesive power ○ ○ ○ -2) Sled ○ ○ ○ -After repeated thermal test 1) Adhesive power ○ ○ ○ − 2) Warpage ○ ○ ○ −

[0021]

According to the present invention, the integrally molded article obtained by the present invention is:
It is excellent in sharpness, can prevent warpage, has excellent adhesive strength between the sheet and the filler-containing material, and has excellent adhesive strength after a thermal test.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-310956 (JP, A) JP-A-58-53428 (JP, A) JP-A-61-11249 (JP, A) JP-A-60-1985 250925 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (9)

(57) [Claims] 1. A synthetic resin molded product obtained by an injection molding method, wherein an aromatic polycarbonate sheet (A) is cut into a predetermined shape and mounted on one side of a mold cavity.
Mold shrinkage [thickness 3.2 mm, outer diameter 101.6 mm disc
The molding shrinkage ratio when a molded product was obtained using a mold
And the formula 100 × (mold size-molded product size) / (mold size)
Value obtained by the method)
0.3% or less, the composite reinforced polycarbonate molding material is less than 0.5% in the vertical direction (B) was injected injected onto the sheet (A), the laminated the sheet (A) and the molding material (B) Synthetic resin molded product (C) obtained by integration. 2. The synthetic resin molded article (C) according to claim 1, wherein the thickness of the aromatic polycarbonate sheet (A) is 0.3 mm or more. 3. The synthetic resin molded product (C) according to claim 1, wherein the aromatic polycarbonate sheet (A) to be mounted on the mold has a shape previously imparted by vacuum molding. 4. The thermoplastic resin used for the aromatic polycarbonate sheet (A) and / or the composite reinforced polycarbonate molding material (B) is a polycarbonate, a polycarbonate / polyethylene terephthalate resin composition, or a polycarbonate / polybutylene terephthalate resin composition. The synthetic resin molded article (C) according to claim 1, which is any one of a product, a polycarbonate / polyamide resin composition, and a polycarbonate / styrene resin composition. 5. The composite reinforced polycarbonate molding material (B) comprises at least polycarbonate and glass fiber.
The synthetic resin molded article (C) according to claim 1, which is a composition containing glass flakes . 6. The synthetic resin molded product (C) according to claim 1, wherein the coefficient of linear expansion of the composite reinforced polycarbonate molding material (B) is 5 × 10 ⁻⁵ / ° C. or less. 7. A synthetic resin molded article (D) having excellent surface clarity, obtained by further coating the synthetic resin molded article (C) according to claim 1. 8. The molded article is a car exterior material.
(C). 9. A synthetic resin molded product obtained by an injection molding method, wherein an aromatic polycarbonate sheet (A) is cut into a predetermined shape and mounted on one surface of a mold cavity.
Mold shrinkage [thickness 3.2 mm, outer diameter 101.6 mm disc
The molding shrinkage ratio when a molded product was obtained using a mold
And the formula 100 × (mold size-molded product size) / (mold size)
Value obtained by the method)
0.3% or less, the composite reinforced polycarbonate molding material is less than 0.5% in the vertical direction (B) was injected injected onto the sheet (A), the laminated the sheet (A) and the molding material (B) A method for producing a synthetic resin molded product (C) to be integrated.