JPS5855899B2 - Manufacturing method for patterned molded bodies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an unsaturated polyester resin molded article, and in particular, the raw resin compound is once thickened and then finely divided.
By heating and pressing again, an unsaturated polyester resin molded article having a characteristic joining pattern and arrangement pattern is obtained.

Molded products of unsaturated polyester resin C (abbreviated as UP resin hereafter) have advantages such as excellent strength, heat resistance, and low-pressure moldability, and are widely used in interior products such as bathtubs and washbasins, building materials, and automobile parts. It is used.

However, when considering the above-mentioned uses, it is extremely advantageous to have not only a single color but also a pattern in order to increase the product value.

The method of patterning a UP resin molded product is to set a woven fabric, non-woven fabric, paper, or glass fiber mat with a pattern printed on it on the top surface and impregnate it with the molding material.
A method is known in which a reinforcing rigid base plate and a molding material are set on the back surface and the two are bonded together.

However, when using this method, the pattern obtained is a surface pattern, and it is not possible to give the same pattern as the surface to an arbitrary cross section of the interior, so post-processing is not possible, and the objects are limited.

Furthermore, because it is a surface pattern, it lacks depth and natural realism, and in complex shapes such as deep drawing, there may be overlaps in the patterned fabric, paper, etc., lack of pattern, or discontinuity of the pattern at joints. This also has the disadvantage that the molded shape is limited to a flat shape.

In addition, many other molded products and molding methods are known under the name of artificial marble, but most of them are due to incomplete mixing of coloring agents to resin, and the resulting patterns are completely random. Therefore, the pattern boundary line cannot help but become unclear.

Firstly, this invention eliminates the disadvantages of the conventional patterning method for UP resin moldings as described above, and solves the problem of combining small parts with almost the same pattern on the surface and inside, and with clear boundaries. It is an object of the present invention to provide a method for manufacturing a UP resin molded body having a so-called mosaic pattern.

Another object of the present invention is to provide a method for producing a patterned resin molded article that has excellent color tone, weight feel, texture, and realism, and has excellent moldability even for complex molded shapes.

The above-mentioned object is achieved by a method for producing a patterned molded body, which is characterized by including the following steps (a) to (d).

(a) Preparing two or more UP resin compounds having different color tones.

(b) a step of thickening the resin compound, (
c) subdividing the thickened compound, (d
) Fill the above-mentioned subdivided compound into a predetermined mold,
A process of forming under pressure.

Hereinafter, the present invention will be described in further detail with reference to the drawings as necessary.

In this manual, "UP resin compound is an esterification product of an unsaturated dibasic acid or a saturated dibasic acid added thereto with glycol, or an unsaturated dibasic acid and an unsaturated dibasic acid. A substantially crosslinked prepolymer of alcohol and an unsaturated polyester selected from a mixture thereof are dissolved in a reactive monomer having an ethylenically unsaturated bond such as styrene or methyl methacrylate, and if necessary, UP obtained by adding a polymerization inhibitor
Resin: Refers to a molding material that further contains low-shrinkage additives, colorants, filler curing agents, thickeners, etc. as necessary, and has thickening and hardening properties by itself.

UP resin 100 parts by weight C or less, "parts" unless otherwise specified
0 to 40 parts of thermoplastic polymers such as polystyrene or polymethyl methacrylate are used as low-shrinkage additives, and 0 to 500 parts of calcium carbonate, talc, or silica sand are used as fillers. , glass fiber strands (
(preferably relatively short Id2 to 6U), etc.
The curing agent contains 0.2 to 3 parts of t-gyl perbenzoate, organic peroxide such as cumenha dropperoxide; the thickening agent contains 0.1 to 5 parts of MgO, Ca(OH)2, etc. oxides or hydroxides of alkaline earth metals are used as required.

In addition, when using a crystalline unsaturated polyester which is an esterification product of antiresin group glycol and fumaric acid or a lower alkyl ester of fumaric acid as the unsaturated polyester in the UP resin, a thickener may be added. It is possible to thicken the UP resin compound by crystal growth without any special addition.

Therefore, in the present invention, the thickening of the compound is carried out by a completely different method from the curing of the compound, and by thickening rather than curing, it is possible to advantageously form a pattern on the final cured molded product. be.

In this way, two or more UP resin compounds having mutually different color tones according to a predetermined design are prepared,
After charging each into an appropriate container, if a thickener is used, it is aged for about one to several days at a temperature of room temperature to about 40°C, or if a crystalline unsaturated polyester is used, it is heated. A thickened solid compound is obtained by aging at room temperature or slightly cooled state 1.

FIG. 1 is a perspective view of the resin compound thus thickened.

The thickened compound obtained as described above is then processed by any solid subdivision means such as a crusher, cutter pelletizer, granulator, preforming press, etc. into a shape and size compatible with the predetermined mosaic shape. The molding compound C (hereinafter abbreviated as PMC) is preformed into pellets (FIG. 2).

Here, the term "comminuted" means to be made relatively small compared to the thickening compound, and does not determine its absolute size.

However, in order to enable deep drawing without losing the clarity of the pattern even with random filling in the subsequent forming process, PMC having a diameter of about 1 to 20 mm is preferably used.

Next, the obtained PMC is filled into a predetermined mold (Fig. 3) and molded under heat and pressure (Fig. 4). By releasing the mold, the pattern is clear and the inside has almost the same pattern as the surface. A cured UP resin molding having the following properties is obtained.

Note that "filling" here refers not only to charging PM randomly into a mold, but also to charging PM with different colors and textures.
C in a mold according to a predetermined design.

Moreover, a mosaic pattern can be obtained by mixed filling of PMCs of different colors and textures.

This is obtained when using a UP resin compound containing a filler, and during heating and pressure molding, the voids in the mold are filled by the flow of molten resin, so PM
At the joint part C, a part rich in resin is formed compared to other parts, and a clear mosaic pattern is formed between this part and other parts.

Such a bonded pattern is obtained when using PMC containing fillers with a plurality of colors and textures, and is particularly preferable for expressing a natural stone mosaic pattern.

As described above, this invention was obtained by skillfully utilizing the preprocessing suitability of the thickened UP resin compound and the flow characteristics before curing and molding, and the method for producing a patterned molded article of the invention and the method thereof. According to the obtained molded product, a) The front surface, back surface, and interior have almost the same pattern, so even if post-processing such as cutting and polishing is performed, there will be no substantial change in the pattern on the cut or polished surfaces. No change occurs; Mouth) It is possible to set the design to some extent in the formation of the mosaic pattern, and a molded product can be obtained that maintains a clear boundary between the mosaics; ...) The pattern is formed on the inner layer 1 of the molded product. As a result, the depth increases and the impression of reality can be obtained; d) Clear boundaries can be similarly obtained during deep drawing; and other advantages can be obtained.

The present invention will be explained in more detail with reference to Examples below.

example Three types of compounds A and B with the mixing ratio shown in the table below.

C was prepared.

The above three types of UP resin compounds A, B, and C were aged at room temperature for 2 days to form a solid thickened compound, which was cut into cubes with 5 sides on each side using a cutter, and then shaken in a pie break. A granular PMC with a diameter of about 3 mm was obtained.

This PMC-person. 1 each of PMC-B and PMC-C:
When it was randomly scattered and filled into the mold at a ratio of 1:1 and molded for IO minutes at a pressure of 100 kg/CIrL2 and a press temperature of 120°C, the three-color pattern of black, gray, and white was randomly formed. A molded article having a mosaic pattern was obtained.

[Brief explanation of drawings]

1 to 5 are explanatory diagrams of an example of a series of steps of the method for manufacturing a patterned molded body of the present invention, FIG. 1 is a perspective view of a thickening compound, FIG. 2 is a perspective view of a PMC, and FIG. The figure is a cross-sectional view of the mold showing the filling state, Figure 4 is a cross-sectional view of the mold after heating and pressing, and Figure 5 is a cross-sectional view of the mold showing the filling state.
The figure is a perspective view of the product after demolding. 1...PMC12...Type, 1'...
···Molding.

Claims (1)

[Scope of Claims] 1. A method for producing a patterned molded article, which comprises the following steps (a) to (a). (a) Preparing two or more unsaturated polyester resin compounds having different color tones. (b) A step of thickening the resin compound. (c) A step of subdividing the thickening compound. (d) A step of filling the above-mentioned subdivided compound into a predetermined mold and molding it under heat and pressure.