JPH08142117A - In-mold cover-molding method - Google Patents

Abstract

PURPOSE: To manufacture articles with an enhanced heat insulating property by further improving the adherence of a covering layer to the resin molded item. CONSTITUTION: The inmold covering molding method is to form a covering layer on the surface of a resin molded item by heat-pressing a thermosetting resin molding raw-material 1 by a split mold 2, and then injecting a covering material into the split mold 2A. By a first injector 7 provided on one mold of the spilt mold 2, a covering material is injected into the split mold 2 in order to form a covering layer on one surface of the resin molded item, and thereafter, by a second injector 8 provided on the other mold of the split mold, a foam resin material is injected to then be foamed into the other surface of the resin molded item.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for molding a thermosetting resin molding material by heat and pressure molding using a split mold, and injecting a coating material into the split mold in a cured or semi-cured state to obtain a surface. The present invention relates to an in-mold coating molding method in which a coating layer is formed on at least one of the above.

[0002]

2. Description of the Related Art Conventionally, a thermosetting resin molding material is heated and pressure-molded using a split mold, and a coating material is injected into the split mold in a cured or semi-cured state so that at least one of the surfaces of the mold can be covered. An in-mold coating method for forming a coating layer is known from JP-A-6-15669.

In this conventional example, molding is carried out using an apparatus as shown in FIG. 9, and a thermosetting resin molding material 1 is heated and pressed by a split mold 2 to form a resin molded product 3. After that, by injecting the coating material 4 from the tank 11 into the split mold 2, the coating layer 5 is formed on the surface of the resin molded product 3.
In-mold coating molding method for forming resin
When the coating material 4 is injected on the surface of the resin mold 3, the fluid is pressed into the split mold 2 from the fluid tank 20 to compress the outer surface of the resin molded product 3. Then, in the above-mentioned conventional example, the outer surface of the resin molded product 3 is compressed by pressurizing a fluid such as air, and the compression force causes the adhesion of the coating layer 5 to the resin molded product 3. I am trying to improve.

[0004]

The object of the present invention is to further improve the adhesion of the coating layer to the resin molded product, and in addition, it is possible to manufacture a product having a high heat insulating property. An object is to provide an in-mold coating molding method.

[0005]

In order to solve the problems of the above-mentioned conventional examples and to achieve the object of the present invention, the in-mold coating molding method of the present invention uses a thermosetting resin molding material 1 as a split metal mold. In-mold coating molding method of forming a coating layer 5 on the surface of the resin molded product 3 by injecting a coating material 4 into the split mold 2 after heating and pressing by the mold 2 to form a resin molded product 3. In, the coating material 4 was injected into the split mold 2 by the first injection machine 7 provided in one of the split molds 2 to form the coating layer 5 on one surface of the resin molded product 3. After that, the expandable resin material 6 is injected into the other surface of the resin molded product 3 by the second injection machine 8 provided in another mold of the split mold 2 to foam. .

[0006]

According to the present invention of the method as described above, the coating material 4 is formed by the first injection machine 7 provided in one of the split molds 2.
Is injected into the split mold 2 to form the coating layer 5 on one surface of the resin molded product 3, and then a foaming resin material is applied by the second injection machine 8 provided in another mold of the split mold 2. By injecting 6 into the other surface of the resin molded product 3 to cause foaming, each part of the other surface of the resin molded product 3 is uniformly and strongly compressed by the foaming pressure of the injected foamable resin material 6, and the resin is Adhesive force between the one surface of the molded product 3 and the coating layer 5 is sufficiently given. Since the coating layer 5 is firmly adhered to one surface of the resin molded product 3 in the formed product, the surface quality of the resin molded product 3 is improved, and the resin molded product 3 has a good surface quality. Since the foam layer 9 is formed on the other surface, a product having high heat insulation can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. 1 to 8 show the manufacturing sequence of the present invention. The split mold 2 constituting the mold device is composed of a first mold 2a which is a lower mold and a second mold 2b which is an upper mold. In the embodiment shown in the accompanying drawings, the first mold 2a is the first mold. The mold 2a is a fixed mold, the second mold 2b is a movable mold, and the second mold 2a is a movable mold, and the second mold 2b is a movable mold.
The molding die 2b is moved vertically.
The first molding die 2a is provided with an injection port 7a of a first injection machine 7, and a coating material 4 such as a molding resin for forming the coating layer 5 is injected into the coating material supply device 1 such as a cylinder.
0 allows injection from the injection port 7a.
In the figure, 11 is a tank containing the coating material 4. Reference numeral 12 is an on-off valve 12 provided at the inlet 7a.

On the other hand, the second molding die 2b is provided with an injection port 8a of the second injection machine 8, and the foaming resin material 6 contained in the tank 14 is injected by the second injection machine 8. 8a
It is possible to inject from. Here, the injection port 8a
An on-off valve 15 is provided in the. Then, in manufacturing a product having the coating layer 5 on the surface of the resin molded product 3 by using the above-described mold apparatus, it is carried out as follows. That is, first, as shown in FIG.
To form the space 16, and in this state, the thermosetting resin molding material 1 which is the material of the resin molded product 3 is placed on the first molding die 2a. Here, a glass fiber reinforced thermosetting resin is used as the thermosetting resin molding material 1, and unsaturated polyester resin or the like is used as a filler such as calcium carbonate or aluminum hydroxide, a curing agent, or a fiber such as glass fiber or carbon fiber. BMC (bulk molding compound), SMC (sheet molding compound), etc., in which a reinforcing agent and, if necessary, a thickener, a coloring agent, etc. are mixed, and these BMC and SMC are formed on the mold 2a. It is installed and supplied.

Next, as shown in FIG. 2, the second molding die 2b is lowered and clamped to compress the thermosetting resin molding material 1 under pressure to mold the resin molding 3. Then, as shown in FIG.
The molding die 2b is slightly raised to form a slight gap between the surface of the resin molding 3 and the first molding die 2a (here, the resin molding 3 is used in the step of FIG. 3). The reason why the second molding die 2b rises is that the second molding die 2b has a mold structure called an undercut).

Next, as shown in FIG. 4, the on-off valve 12 is opened and the unsaturated polyester type, vinyl ester type, epoxy type,
A coating material 4 such as a molding resin made of a resin such as an acrylic resin or a resin in which these resins are mixed is used as a first injection machine 7 from the injection port 7a to the front surface side of the resin molding 3 and the first molding machine 7.
Of the coating material 4
When the injection is completed, the on-off valve 12 is closed as shown in FIG. 5 and recompression molding is performed to mold the coating layer 5 on the surface side of the resin molded product 3.

Thereafter, as shown in FIG. 6, the second molding die 2b is slightly lifted, and the other surface of the resin molded product 3 and the second molding die 2 are moved.
b, a slight gap is formed between the resin molding 3 and the first molding die 2a even though the second molding die 2b is lifted as in the step shown in FIG. The reason is that the resin molded product 3 is released from the second molding die 2b by a release device separately provided in the second molding die 2b. -6397
The mold releasing device disclosed in Japanese Patent No. 8 can be used).

Next, as shown in FIG. 7, the on-off valve 15 is opened and a foaming resin material 6 such as a silicone rubber-based or urethane-based thermosetting foaming material is injected by the second injection machine 8. 8a to the other surface of the resin molded product 3 and the second molding die 2b
Pressure injection into a small gap between the
Is closed, and recompression molding is performed as shown in FIG. The timing at which the expandable resin material 6 is injected into the split mold 2 is such that the coating material 4 for forming the coating layer 5 injected in the step of FIG. 4 is semi-cured or cured.
In order to further improve the adhesiveness of the coating material 4, it is desirable to inject the foamable resin material 6 in a state where the coating material 4 is semi-cured. When the foamable resin material 6 is injected under pressure and recompression molded in this way, even if the resin molded product 3 has irregularities, not only the flat surface portion but also the sloped surface portion and the substantially vertical portion are uniformly pressed. However, in the present invention, the foamable resin material 6 is further foamed and its volume is expanded, so that the resin molded product 3 is obtained.
One side of the is more strongly compressed and the coating material 4 and the resin molded product 3
Thus, the thermosetting resin molding material 1 for forming the film is evenly adhered at each part.

Thereafter, as shown in FIG. 7, the second molding die 2b is raised to open the die, and the product is taken out in this state. In the embodiment shown in the accompanying drawings, an example of a bathtub is shown as a product. The bathtub thus produced has a container-shaped resin molded product 3 with the coating layer 5 adhered to the surface thereof with a uniform adhesive force, and a foam layer 9 is formed on the other surface (that is, the back surface) of the resin molded product 3. It is formed in a tightly adhered state. When the foam layer 9 is integrally formed on the back surface of the resin molded product 3 as described above, the heat insulating effect is enhanced when the product is a bathtub or the like.
It can be used as a bathtub where the hot water inside does not easily cool.

In the above molding, the molding conditions for molding the bathtub include the first molding die 2a and the second molding die 2
In both cases, the mold temperature is 120 ° C. to 130 ° C., and the molding pressure is the thermosetting resin molding material 1
About 1000 tonf, and coating material 4 about 1
500tonf, about 1500t molding of foaming resin material
is onf.

Next, the evaluation results of the test of the adhesion of the coating layer between the test body obtained by the method of the present invention and the test body obtained by the conventional in-mold coating molding method will be described. (Evaluation Test Method) As an evaluation test method, the "cross-cut test" described below was performed to evaluate the adhesion of the coating layer.

Cross-grid test method (1). Using a cutter knife on the surface of the test body coating layer 5
Draw straight lines that reach 11 thermosetting resin molding materials at mm intervals. (2). Draw 11 straight lines so that they are orthogonal to the line drawn in (1), and make a grid.

(3). An adhesive tape is attached on the grid and peeled off, and the number of remaining grids (the number of coating layers remaining) is examined. By the above method, the effects of the test body obtained by the method of the present invention and the test body obtained by the conventional in-mold coating molding method were evaluated. Results Horizontal part of the test body obtained by the conventional in-mold coating molding method 100/100 inclined surface part 99/100 Horizontal part of the test object obtained by the method of the present invention 100/100 inclined surface part 100/100 As is clear from the above, it is clear that the test body obtained by the method of the present invention has a better adhesion of the coating layer 5 to the resin molded product 3.

[0018]

As described above, according to the present invention, in the in-mold coating molding method, the coating material is injected into the divided molds by the first injection machine provided in one of the divided molds. After forming a coating layer on one surface of the resin molded product, a foaming resin material is injected on the other surface of the resin molded product by a second injection machine provided in another mold of the split mold. Since the foaming resin material foams, each part of the other surface of the resin molded product is uniformly pressed by the foaming of the foaming resin material, and the volume expansion due to the foaming of the foaming resin material improves the adhesion of the coating layer to the resin molding product. In addition, a foamed layer is formed on the surface of the resin molded product on the side opposite to the coating layer, which can improve the heat insulating property of the product. , As a foamable resin material for forming the foam layer If the excellent thermal and the material, it is capable of adding functionality to the product.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a manufacturing sequence of the present invention.

FIG. 2 is an explanatory view showing a manufacturing sequence of the above.

FIG. 3 is an explanatory view showing the manufacturing sequence of the above.

FIG. 4 is an explanatory view showing the manufacturing sequence of the above.

FIG. 5 is an explanatory view showing the manufacturing sequence of the above.

FIG. 6 is an explanatory view showing the manufacturing sequence of the above.

FIG. 7 is an explanatory view showing the manufacturing sequence of the above.

FIG. 8 is an explanatory view showing the manufacturing sequence of the above.

FIG. 9 is a cross-sectional view of a conventional device.

[Explanation of symbols]

 1 Thermosetting Resin Molding Material 2 Divided Mold 3 Resin Molded Product 4 Covering Material 5 Covering Layer 6 Foaming Resin Material 7 First Injection Machine 8 Second Injection Machine

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // B29K 101: 10 105: 04 B29L 9:00 (72) Inventor Naoto Ikegawa Osaka Kadoma City, Osaka 1048 Kadoma Matsushita Electric Works Co., Ltd. (72) Inventor Mitsunori Kobayakawa, Kadoma City, Osaka Prefecture 1048 Kadoma, Matsushita Electric Works Co., Ltd. In-house (72) Inventor Shozo Tanaka 5-8 Nishimitabicho, Suita City, Osaka Prefecture Japan Catalytic Resin Research Institute (72) Inventor Shigeru Oka 5-8 Nishiomitabicho, Suita City, Osaka Prefecture Japan Catalytic Resin Technology Laboratory

Claims (1)

[Claims] 1. A thermosetting resin molding material is heated and pressed by a split mold to form a resin molded product, and a coating material is injected into the split mold to form a coating layer on the surface of the resin molded product. In the in-mold coating molding method of forming, a coating material is injected into the split mold by a first injection machine provided in one of the split molds to form a coating layer on one surface of the resin molded product. After the formation, a foaming resin material is injected into the other surface of the resin molded product by a second pouring machine provided in another mold of the split mold to foam the resin, and the molding is performed in the mold. Method.