JPS5817766B2 - resin composition - Google Patents

Description

Detailed Description of the Invention The present invention relates to a molded resin composition, and the present invention relates to a polystyrene resin composition in the form of a sheet, film, or other shape that has a beautiful wood grain pattern on its surface without using any printing or laminating methods. The purpose is to provide molded products.

Conventionally, polystyrene resins have been widely used in the form of films, sheets, and other shapes, and are given various colors and patterns as needed to increase their commercial value.

Coloring is generally done on the resin before molding or during molding, but in most cases it is a single color and no color pattern can be formed.

On the other hand, methods for applying colored patterns include direct printing on the surface of the molded product, lamination of films with printed patterns, etc., and mixing colored pellets with different shapes and hues.
There is a method of creating a pattern on the surface (by insufficiently melted wires), but the method of adding a pattern after molding is not expensive due to the process, while the method of creating insufficiently mixed wires has a low productivity. There are technical problems) and it is not practical.

In other words, extrusion molding machines and injection molding machines are generally designed to have sufficient kneading performance, so even multiple pellets of different colors cannot be kneaded uniformly and a pattern cannot be created. , productivity is poor) and costs are high.

Furthermore, in color molding of polystyrene, masterbatches and dry colors are often used as colorants, and in such cases the dilution ratio is 40 to 60 times, so be sure to mix them thoroughly. Unless otherwise specified, it will be impossible to color the base color of the molded product.

The present inventors have developed a technology that efficiently imparts a beautiful pattern to the surface of a molded product at the same time as molding, without forcibly lowering the performance of various conventional molding machines or changing the process or equipment. As a result of extensive research, we have found that by molding polystyrene resin or adding specific colored or uncolored resin during colored molding, molded products with beautiful wood grain patterns on the surface can be easily and efficiently produced. The present invention was completed after discovering that this can be obtained well.

That is, the present invention is a resin composition formed by melt-kneading and molding a polystyrene resin and an ultra-heat-resistant polystyrene resin, characterized in that one or both of the above components are colored. That is.

To explain the present invention in more detail, the present inventors discovered that when molding polystyrene resin into a colored or uncolored sheet by extrusion molding, it is necessary to apply any pattern such as printing or film lamination after molding. In order to create a wood grain pattern on the surface of the molded product without reducing the performance of conventionally known molding machines, the raw polystyrene pellets are colored with various colors that flow less easily when melted than the raw polystyrene pellets. Beret, e.g. As resin, ABS
Colored pellets of resins, acrylic resins, polypropylene resins, various natural or synthetic rubbers, polyesters, polyamides, etc. were mixed, extruded, and formed into sheets. In the molding machine used, sufficient melting and kneading was carried out, and almost no pattern could be formed on the surface of the molded product.

However, when we tried using super heat-resistant polystyrene resin, which belongs to the same family as the raw material polystyrene resin, in place of the chemically different colored pellets mentioned above, we unexpectedly found an extremely beautiful wood grain pattern. This is what we discovered that can be manifested.

It was also recognized that such a method is not limited to extruded sheets, but can also be applied to molded products of other shapes.

The "polystyrene resin" in the present invention.

It is generally used for molding purposes, and includes polystyrene homopolymers and polystyrene-based resins with improved various properties that contain one unit of other monomers.

These polystyrene resins are distinguished mainly by their heat distortion temperature and Vicat softening point.

Such polystyrene resin may be colored or uncolored.

If it is colored, it may be colored in advance before forming the resin composition of the present invention, or it may be colored on the spot during formation of the resin composition of the present invention.

In terms of cost, it is more advantageous to color the film on the spot during its formation.

When using colored polystyrene resin, colored pellets or powder may be used.

Further, as a method for coloring on the spot, conventionally known coloring methods such as a color masterbatch method, a dry color method, etc. can be used as they are.

Such colored or uncolored polystyrene resin may be in any shape such as powder, pellet, or flake.

The "super heat-resistant polystyrene resin" used in the present invention is typically a styrene copolymer resin manufactured by Arcopolymer in the United States, and its heat resistance is significantly higher than that of conventional general-purpose polystyrene resins. For example, it is 20 to 30 degrees Celsius better than general-purpose polystyrene, and 10 to 30 degrees colder than As resin.
It has excellent heat resistance at 15°C and 20-25°C as well as ABS resin.

These super heat-resistant polystyrene resins are Sekisui Dailark+232,238°240.250.265.3
32.338.350 etc., 1
Heat distortion temperature of 05℃ or higher (ASTMD648, load 18
．． 56Icg/cm2.90℃annealed),! :110
It is characterized by having a Vicat softening point (ASTM D1525) of ℃ or higher, and is clearly distinguished from the polystyrene resins mentioned above in terms of such heat resistance.

Such super heat-resistant polystyrene resin should be colored if the polystyrene resin is uncolored, and if the polystyrene resin is colored, it should be colored even if it is not colored. However, if it is colored, it should have a different hue from that of the polystyrene resin, or if it has the same hue, it should have a different density.

Such super heat-resistant polystyrene resin can be in any shape such as powder, pellet, or flake.
The smaller the particle size, the finer the wood grain pattern can be formed, while the larger the particle size, the rougher the wood grain pattern.

The most preferred shape is about 1 to 5 pellets.

Such super heat-resistant polystyrene resin is used in an amount of about 0.1 to 50 parts by weight, preferably about 0.1 to 5 parts by weight, per 100 parts by weight of polystyrene resin.

The essential components of the resin composition of the present invention are as described above,
In addition, various additives such as ultraviolet absorbers, stabilizers, flame retardants, fillers, extenders, other compatible resins, etc. can be optionally added as necessary.

The resin composition of the present invention comprising the above-mentioned essential components and optional components is manufactured by being molded into various shapes using an extrusion molding machine, an injection molding machine, or other melt mixing type molding machine.

Typical examples of such molded compositions of the present invention include sheet-like products, film-like products, columnar products, and
Examples include irregularly shaped extrudates, and other examples include various injection molded products.

For example, if a thin material is manufactured continuously by extrusion molding, the surface of the molded product will have various colors depending on the color, usage ratio, and shape (e.g., pellet size, etc.) of the raw materials used. For example, by adopting a color similar to that of wood, a sheet having a wood grain similar to that of wood can be obtained continuously and easily at low cost.

A particular advantage of the present invention is that it does not require any printing or laminating processing, and does not require any changes in the design of high-performance molding machines that have been widely used in the past, and therefore has a beautiful wood grain pattern with high efficiency. This is because we can provide molded products.

Next, the present invention will be specifically explained with reference to Examples.

Note that the words "department" or "section" in the text are based on weight.

Example 1 Polystyrene resin (Nippon Steel Chemical Co., Ltd., Estyrene S-6
0) 100 parts, color masterbatch for polystyrene (
reddish brown) 2 parts, and super heat-resistant polystyrene resin (manufactured by Arco Polymer, USA, Sekisui Dailark≠232,
0.5 parts of black pellets (carbon black: 1 inch) consisting of carbon black (heat deformation temperature: 113°C, Vicat softening point: 118°C) and carbon black were placed in a mixer (rotation speed: 3 Orpm).
) for 10 minutes and the mixture was passed through a 90m extruder at a melt temperature of about 230-240°C under normal operating conditions.
When extrusion molded into a sheet with a thickness of 1.5 m, thin black lines appeared randomly on the surface of the sheet in a wood grain pattern on a reddish-brown background, giving it an excellent appearance. Ta.

When this sheet was formed into tableware using a vacuum forming method, it had a significantly more luxurious feel compared to conventional single-colored tableware.

For the purpose of comparison, a sheet was formed using polystyrene resin (Estyrene S-60) pellets of the same amount and pigment concentration in place of the black pellets in the above, and the other conditions were the same as above. Only a uniformly colored sheet with some blackening throughout was obtained), and no wood grain pattern appeared even if the extrusion speed was reduced.

Example 2 100 parts of polystyrene resin (Estyrene S-60),
Color masterbatch for polystyrene (yellow green) 4 parts and super heat-resistant polystyrene resin (Sekisui Dailark+332, heat distortion temperature 121℃, Vicat softening point 13
1℃) and red iron oxide (excluding pigments)
When a sheet with a thickness of 0.5 cranes was formed using 1 part of 1 part of Example 1 and the rest was the same as in Example 1, the surface of the sheet had reddish-brown grain-like thin lines in a uniform yellow-green background color. When aluminum was vapor-deposited on this sheet and vacuum-formed into plate-shaped tableware, the tableware had a heavy appearance with the texture of sumac.

Example 3 Sekisui Dailark≠2 as super heat-resistant styrene resin
40.4250. ≠238F・20°+265, ≠3
32. -IP350. ≠338F20 in Example 1
When a sheet was formed in the same manner as in Example 1 except for using Sekisui Dailark≠232, the same results as in Example 1 were obtained.

Example 4 100 parts of Estyrene H-60 (manufactured by Nippon Steel Chemical Co., Ltd., polystyrene for injection molding), reddish-brown color masterbatch (Estyrene H-60 85%, organic pigment 15%), and the super heat-resistant polystyrene of Example 1 black pellet 0.5
The mixture was mixed well and a plate-shaped molded product was manufactured from the mixture at 230° C. using a 3.5 oz. in-line screw type injection molding machine.

This molded product had a black grain-like pattern appearing vividly and randomly on a reddish-brown background, making it suitable as a material for folk art-style tools.

Example 5 Polystyrene resin (Styron 475D, manufactured by Asahi Dow)
100 parts, 2 parts of color masterbatch for polystyrene (green), and 0.5 part of super heat-resistant polystyrene resin (Sekisui Dairaku +-332, heat distortion temperature 121°C, Vicat softening point 131°C) were mixed for 10 minutes in a mixer. death,
The mixture was extruded into a 0.5 m thick sheet using a 90 m extruder at a melt temperature of approximately 230-240°C under normal operating conditions. The thin lines appeared randomly like the veins of a leaf, creating a brotherly pattern that could never be expressed in one print.

Example 6 100 parts of polystyrene resin (manufactured by Denki Kagaku Kogyo, Denka Styrol TP), super heat-resistant polystyrene resin (Sekisui Dairaku≠232, thermal i-form temperature 113°C, Vicat softening point 118°C) and copper phthalonanine Mix 1 part of blue and colored blue halet (0.3% Nyanin blue) in a mixer for 10 minutes, and then mold the mixture into a 3.5-inch main line screw type injection molding machine.
A plate-shaped molded product was manufactured at 0°C.

This molded material was a transparent plate with blue streaks that looked like curved strata, making it suitable for use as a decorative material.

Claims (1)

[Scope of Claims] 1. A resin composition obtained by melt-kneading and molding a polystyrene resin and an ultra-heat-resistant polystyrene resin, and at least one of the components is colored. 2. The resin composition according to claim 1, wherein the polystyrene resin is colored in advance. 3. The resin composition according to claim 1, wherein the polystyrene resin is colored during melt-kneading with the super heat-resistant polystyrene resin. 4. The resin composition according to claim 4, which uses 100 parts by weight of polystyrene resin and about 0.1 to 50 parts by weight of super heat-resistant polystyrene resin. 5. The resin composition according to claim 1, wherein the super heat-resistant polystyrene resin is a colored pellet having a particle size of about 1 to 5 mm. 6. The resin composition according to claim 1, wherein the super heat-resistant polystyrene resin has a Picat softening point of 110° C. or higher. 7 Super heat-resistant polystyrene resin has a heat distortion temperature of 105°C or higher (load 18.56 mm/cm 2.90°C annealing)
The resin composition according to claim 1, which has the following. 8. The resin composition according to claim 1, which is an extrusion molded sheet.