JPH11198292A - Pigment-containing resin sheet laminated body, its manufacture, and decorative sheet for building material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit generation of residue, and thereby to prevent product contamination and enable stable operation for an extended period by making a pigment concentration in a thermoplastic resin of a surface layer lower than that of a thermoplastic resin of an inner layer. SOLUTION: A pigment concentration in a thermoplastic resin for surface layer is made lower than that of a thermoplastic resin for inner layer for co- extruding. By making the pigment concentration in a layer contacting with a die (the surface layer) lower than that of a layer not contacting to the die (the inner layer), generation of residue can be inhibited considerably compared with co-extruding of a resin having a uniform pigment concentration throughout. At this time, the pigment concentration in the thermoplastic resin for surface layer is preferably 7 pts.wt. or lower, specially 5 pts.wt. or lower with respect to 100 pts.wt. thermoplastic resin. When it is over the above range, the residue is liable to generate. On the other hand, an upper limit of the pigment concentration in the the thermoplastic resin for inner layer is normally 40 pts.wt., preferably 30 pts.wt., and more preferably 20 pts.wt. with respect to 100 pts.wt. thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pigmented resin sheet laminate, a method for producing the same, and a decorative sheet for building materials.

[0002]

2. Description of the Related Art In the production of a pigmented thermoplastic resin sheet by an extrusion method, a liquid, gel or solid ejected material around a die lip of an extruder (usually referred to as an "eye-to-eye" in many cases, , Use this expression) and accumulate on the surface of the molded article to contaminate the product. In addition, a substance similar to eyes or the like adheres to the inside of the die lip and changes the flow of the resin, which may result in poor appearance such as die line and uneven color. They are,
According to the fact that the strong polar pigment is inferior in affinity with the resin, it is repelled from the laminar flow of the resin inside the die, flows as a side flow to the machine wall, and tends to adhere due to the affinity with the metal surface of the die wall. It is considered. Further, the above-mentioned molded article is transported via a roll. At this time, the roll surface may be contaminated by the adhesion of the pigment.

[0003] In order to cope with the above-mentioned problems, there is known a method of using an inhibitor in the eyes. Specifically, a method in which a silicate compound such as silica, inorganic silicate, zeolite, etc. is blended with the resin in order to scrape off the eyes before it accumulates and accumulates on the metal part in the die, silicon-based resin, organic phosphate For example, there is a method of blending the same with a resin, exuding the resin surface, forming a film between the resin surface and the metal surface, and preventing adhesion to eyes and the like. As another method of forming the film, a method of coating the metal surface inside the die with an organic fluorine compound in advance has been proposed.

[0004] However, in the method of adding an additive, if the number of added parts is low, no effect is obtained. In particular, when an inorganic substance is added, the metal surface inside the die is scraped off, and there is a possibility that discoloration and contamination by metal powder may occur. In addition, it is difficult to form a uniform film by the method of forming a film at the interface between the resin and the metal, which may adversely affect the method, and a film is also formed on the surface of a molded product. As a result, there are problems that the surface characteristics fluctuate depending on the molding time of the product, and that the presence of the film deteriorates the riding of the printing ink. In addition, the method of coating the metal surface is not only expensive but also insufficient in terms of long-term stability.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the purpose of suppressing the occurrence of blemishes and thus enabling stable operation for a long time without causing product contamination. It is another object of the present invention to provide a method for producing a pigment-containing resin sheet laminate improved as described above. Another object of the present invention is to provide a pigment-containing resin sheet laminate having a novel structure and a decorative sheet for building materials.

[0006]

That is, the first aspect of the present invention is as follows.
The gist of the present invention is a resin sheet laminate containing a pigment by a co-extrusion method having one or more inner layers between respective surface layers on both surfaces, wherein the pigment concentration in the surface thermoplastic resin is higher than the pigment concentration in the inner thermoplastic resin. A pigmented resin sheet laminate characterized by being made low.

A second gist of the present invention is to produce a resin sheet laminate having at least one inner layer between each surface layer on both sides and at least the inner layer made of a pigmented thermoplastic resin by a coextrusion method. A method for producing a pigment-containing resin sheet laminate, wherein coextrusion is performed by lowering the pigment concentration in the thermoplastic resin for the surface layer than the pigment concentration in the thermoplastic resin for the inner layer.

[0008] A third aspect of the present invention resides in a decorative sheet for building material, comprising the above-mentioned resin sheet laminate.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
First, for convenience of explanation, a method for producing a pigment-containing resin sheet laminate according to the present invention will be described. In the present invention, a resin sheet laminate having one or more inner layers between each surface layer on both surfaces and at least the inner layer made of a pigment-containing thermoplastic resin is manufactured.

In the present invention, the thermoplastic resin includes:
There is no particular limitation as long as it can be formed by an extrusion method and can contain a pigment. For example, polyolefin resins such as polyethylene and polypropylene, vinyl chloride resins, acrylic resins, styrene resins (Each includes a copolymer of a main monomer and a monomer copolymerizable therewith and a mixture of each resin with another resin). Above all, polyolefin-based resins having poor polarity and low compatibility with pigments due to low polarity are apt to cause blemishes during extrusion molding, so that the production method of the present invention is highly effective. To the above-mentioned thermoplastic resin, a compounding agent usually used for a thermoplastic resin composition such as a plasticizer, a stabilizer, a lubricant, a filler, an antioxidant, and an ultraviolet absorber can be added.

In the present invention, as the pigment, for example,
Titanium white, carbon black, titanium yellow,
Inorganic pigments such as iron oxide and ultramarine blue, and organic pigments such as cyanine green, cyanine blue, polyazo pigments, isoindolinone pigments, and quinacridone are used.

In the present invention, co-extrusion is performed with the pigment concentration in the surface layer thermoplastic resin being lower than the pigment concentration in the inner layer thermoplastic resin. In this way, the layer that touches the die (surface layer)
By making the concentration of the pigment inside the layer lower than the layer that does not touch the die (the inner layer), it is possible to remarkably suppress the occurrence of blemishes as compared with the case where a resin having a uniform pigment concentration is extruded as a whole. At this time, the pigment concentration in the surface layer thermoplastic resin is 7 parts by weight or less per 100 parts by weight of the thermoplastic resin,
In particular, the content is preferably 5 parts by weight or less. When the pigment concentration exceeds the above-mentioned range, the occurrence of eye fuzz is likely to occur. On the other hand, the upper limit of the pigment concentration in the thermoplastic resin for the inner layer is not particularly limited, but is usually 40 parts by weight, preferably 30 parts by weight, more preferably 2 parts by weight, per 100 parts by weight of the thermoplastic resin.
0 parts by weight.

In the present invention, among the extrusion molding methods, the present invention can be particularly suitably applied to T-die molding in which the shearing rate is high and the dents due to the pigment are frequently generated. The ratio of the thickness of the surface layer / the inner layer / the surface layer is preferably in the range of 1/98/1 to 25/50/25, from the viewpoint of effectively suppressing the occurrence of eye spots. The thickness of the two surface layers may be the same or different.

Next, the pigment-containing resin sheet laminate and the decorative sheet for building materials of the present invention will be described. The pigmented resin sheet laminate of the present invention is a pigmented resin sheet laminate obtained by the above-described co-extrusion method and having one or more inner layers between the respective surface layers on both surfaces. The pigment concentration is lower than the pigment concentration in the inner layer thermoplastic resin. The pigment-containing resin sheet laminate of the present invention is suitable for applications in which the number of added pigments is high and the concealing properties are strict, and for applications in which the sheet surface is subjected to surface treatment such as printing or embossing. It is suitably used as a decorative sheet for building material applications that often require such quality.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In addition, as a thermoplastic resin, a polypropylene resin (random PP, comonomer:
Ethylene, MFR: 8 g / 10 min, melting point: 138 ° C. (heating rate: 10 ° C./min), and titanium white / carbon black / indolinone / iron oxide) were used as pigments.

Examples 1 and 2 and Comparative Example 1 Three-layer coextrusion was performed. The blending of the polypropylene resin composition used for each layer was as shown in Table 1 below, and the conditions were the same except for the amount of the pigment per 100 parts by weight of the resin. In the case of Comparative Example 1 (standard sample), the same amount of pigment was added to each layer. In Example 1, a master batch having a pigment concentration of 60% by weight was used. .25
5 parts by weight of the pigment in the surface layer, and 5 parts by weight of the pigment in the surface layer. In Example 2, a master batch having a pigment concentration of 60% by weight was used. The content of the pigment in the surface layer was set to 0 (no addition).

The polypropylene-based resin composition having the above mixing ratio is used as a raw material, and a Tmm of 110 mmφ and 75 mmφ is used.
A colored sheet having a total thickness of 100 μm using a die extruder (T die: 2 types and 3 layers, 1750 mm width) at a die temperature of 220 ° C. and a thickness ratio of surface layer / intermediate layer / surface layer of 1/8/1. (That is, the total pigment concentration in the film was the same in both the comparative example and the example).

In the process of producing a sheet by the extrusion molding method described above, the time until the occurrence of blemishes and the amount of the thermoplastic resin extruded so far were measured. In addition, adhesion of the sheet to a roll in a winding apparatus for the manufactured sheet (referred to as “rolled”), the presence or absence of roll contamination, and the color tone of the obtained sheet were visually evaluated. The results are shown in Table 1.

[0019]

[Table 1]

As is clear from Table 1, when manufacturing a resin sheet laminate having the same pigment concentration as a whole, if the pigment concentration in the surface layer is lowered and the amount is compensated for by increasing the concentration in the inner layer. If this is the case, it is possible to suppress the occurrence of eye marks.

[0021]

According to the present invention described above, the occurrence of streaks at the die lip is suppressed, stable operation can be performed for a long time, and a high quality molded product with little surface contamination can be manufactured. You can do it. In the case where the above-mentioned resin sheet laminate is subjected to embossing in which it comes into contact with the roll at a high temperature, prevention of contamination of the roll is particularly important. In such a case, the effect of the method of the present invention is particularly large.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Hattori 2 Oike, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Nagoya Mitsubishi Chemical MKV Corporation Nagoya Office (72) Inventor Yukito Kawamoto 272 Kusunagi-cho, Ako-gun Hyogo Prefecture (72) Inventor: Yoshifumi Hirohata 272, Kamigunicho, Ako-gun, Hyogo Prefecture In-house Chemical Products Division, Kami-gun Plant

Claims (6)

[Claims] 1. A pigmented resin sheet laminate by a co-extrusion method having one or more inner layers between respective surface layers on both surfaces, wherein the pigment concentration in the surface thermoplastic resin is the pigment concentration in the inner thermoplastic resin. A pigmented resin sheet laminate, which is made lower. 2. The resin sheet laminate according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 3. The pigment concentration in the surface thermoplastic resin is 7 parts by weight or less per 100 parts by weight of the thermoplastic resin.
Or the resin sheet laminate according to 2. 4. The ratio of thickness of surface layer / inner layer / surface layer is 1/9.
The resin sheet laminate according to any one of claims 1 to 3, which is in a range of 8/1 to 25/50/25. 5. A method for producing a resin sheet laminate having at least one inner layer between each surface layer on both surfaces thereof, wherein at least the inner layer is formed of a thermoplastic resin containing a pigment, the method comprising the steps of: A method for producing a pigment-containing resin sheet laminate, wherein co-extrusion is performed with the pigment concentration in the thermoplastic resin being lower than the pigment concentration in the thermoplastic resin for the inner layer. 6. A decorative sheet for building material, comprising the resin sheet laminate according to any one of claims 1 to 4.