JPH0429819A - Manufacture of extruded board with pattern - Google Patents

Abstract

PURPOSE:To easily obtain an extruded board with patterns by feeding dye and pigment or resin containing dye and pigment to a second feed section of a two-stage screw extruder. CONSTITUTION:The first object of a first stage 5 is to plasticize and knead a resin, whereas, in a second stage 9, pressure is made zero in a second feed section 11 to effect venting, thereafter the pressure is raised in a second compres sion section 12 and the resin is metered in a second metering section 13. When the resin is fed into the stage 9, the resin is in a molten state and kneading is not required and hence kneading capacity can be made smaller. If dye and pigment or resin containing dye and pigment is fed into the section 11 through a vent hole 10, extrusion can be performed, while dye and pigment, and resin are insufficiently kneaded. A T-die 14 is placed at the end of an extruder so that the resin to extruded in the form of plate. For example, if a three-roll type cooling roll 15 is employed to cool and polish resin, an extruded board with patterns on its surface can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an extruded board having a pattern on its surface, which is used for exterior walls, decorative boards, etc.

[Prior Art] In order to obtain extruded plates made of thermoplastic resin, a two-stage screw extruder as shown in FIG. 2 is often used.

In such an extruder, resin is fed into the first feed section 6, but when dyes and pigments or resins containing dyes and pigments are fed into the first feed section, the dyes and pigments are fed into the first compression section 7 and the first compression section 7. 1 meter ring section 8, and further kneaded in the second feed section 11. The second compression section 12, the second
The mixture is kneaded in the metering section 13. Therefore, the dyes and pigments are uniformly dispersed, and even if the T-dies 14 are arranged to form a plate and the extruded plate is manufactured by cooling and polishing with, for example, three cooling rolls 15, the colored plate has a uniform color. Then,
This does not result in a patterned extruded board having a pattern.

In order to obtain a plate with a pattern, a method is also known in which different types of resins that are poorly compatible with each other are mixed. For example, there is a method of mixing a small amount of polycarbonate resin with acrylic resin and extruding it to create a pattern on the surface, but this has the disadvantage that the excellent weather resistance, which is a feature of acrylic resin, is lost due to the mixing of polycarbonate resin. It ends up.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for manufacturing an extruded plate having a pattern on its surface using a two-stage screw extruder without causing the above-mentioned drawbacks.

[Means and effects for solving the problems] The present invention supplies a thermoplastic resin to the first feed section of a two-stage screw extruder and kneads it, while supplying a dye or pigment to the second feed section of the extruder. The present invention relates to a method for producing a patterned extruded plate, characterized in that a thermoplastic resin containing a pigment is charged and extruded together with the kneaded resin from the previous stage.

FIG. 1 is a schematic diagram of an apparatus suitable for carrying out the invention.

A two-stage screw extruder generally has a first stage 5 with a first feed section 6, a first compression section 7, and a first metering section 8, and a second stage 9 with a second feed section 11 and a second compression section 12. , a second metering section 13.

The vent hole (gas vent hole) H) of the cylinder is arranged near the second feed section. The first stage 5 has the primary purpose of plasticizing the resin and crosstalk, while the second stage
The stage 9 brings the pressure to zero in the second feed section 11 to enable venting, then increases the pressure in the second combination gin section 12 and meters in the second metering section 13. Here, when entering the second stage 9, since the resin has already been melted, there is no need to knead it, and therefore the crosstalk capacity is designed to be small. Therefore, if the dye and pigment or the resin containing the dye and pigment are introduced into the second feed section 11 of the second stage 9 through the vent hole 1O, it is possible to extrude the dye and pigment while the resin is not sufficiently mixed. becomes. A T-die 14 is placed at the tip of the extruder and extruded into a plate shape, for example,
If the extruded plate is cooled and polished using the three-roll cooling roll 15, the extruded plate will have a pattern on its surface.

Although it has been described that dyes and pigments are introduced through the vent hole, the present invention is not limited to this, and a separate input port may be provided.

Thermoplastic resins include acrylic resins, polycarbonate resins, polystyrene resins, polyethylene resins, polypropylene resins, etc., and may contain additives and the like.

Further, as the dye and pigment, both known organic dyes and inorganic pigments can be used, and they may be used alone or in combination of two or more types.

[Example] 1".

Using a two-stage screw type 90φ extruder, white acrylic resin containing 0.5 parts of titanium oxide per 100 parts of resin was introduced from the hopper in the first feed section of the first stage. A black acrylic resin containing 5 parts of carbon black per 100 parts of resin was put into the vent hole in the second feed section of the second stage in an amount of 10% of the extrusion amount, and extruded. A T-die was placed at the tip of the plate to form a plate, and the plate was cooled and polished using three cooling rolls to produce an extruded plate.

The extruded plate had a black irregular pattern on a white background, as shown in FIG.

Comparison ■ A white acrylic resin containing 0.5 parts of titanium oxide per 100 parts of resin and 5 parts of carbon black per 100 parts of resin were prepared using a two-stage screw type 90φ extruder. A mixture of black acrylic resin and black acrylic resin at a ratio of 9:1 is put into the hopper in the first feed section of the first stage, extruded, and made into a plate by placing a T die at the tip of the extrusion. An extruded plate was manufactured by cooling and polishing using a three-roll cooling roll.

As shown in FIG. 4, the extruded plate was a gray colored plate with a uniform mixture of white and black, and no pattern was formed on the surface.

[Effects of the Invention] As explained above, by introducing dyes and pigments or resins containing dyes and pigments into the second feed portion of a two-stage screw extruder, it is possible to easily obtain patterned extrusions and plates. I can do it.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a manufacturing method suitable for the present invention, and FIG. 2 is a schematic diagram of a conventional device. FIG. 3 is a diagram schematically showing the surface of the extrusion plate according to the example, and FIG. 4 is a diagram schematically showing the surface of the extrusion plate according to the comparative example.

Claims (1)

[Claims] The thermoplastic resin is supplied to the first feed section of the two-stage screw extruder and kneaded, while the dye and pigment or the thermoplastic resin containing the dye and pigment are introduced into the second feed section of the extruder, and the thermoplastic resin from the previous stage is fed. A method for producing a patterned extruded plate, which comprises extruding it together with a kneaded resin.