JPH07285158A - Manufacture of thermoplastic resin sheet - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin sheet having an excellent mat feel by a method wherein a first thermoplastic resin and a second thermoplastic resin wherein a viscosity difference from the first plastic resin and a viscosity ratio thereto are respectively at least specific values, and it has a viscosity of a specific value or under without adhesiveness, are stayed in a mold, co- extruded, cooled, and thereafter the second thermoplastic resin layer is removed by peeling off. CONSTITUTION:A first thermoplastic resin and a second thermoplastic resin wherein a viscosity difference from the first thermoplastic resin is at least 3000 poise, a viscosity ratio thereto is at least 1.3, and it has a viscosity of at most 50000 poise and is free from adhesiveness to the first thermoplastic resin, are co-extruded after at most 5 to 60s of staying time in a mold. A fine irregularity 1 is formed on an interface between the first and the second thermoplastic resin layers 5, 6. Since the first and the second thermoplastic resin have no adhesiveness to each other, the second thermoplastic resin layer 6 can be removed by peeling off after cooling, and a separated surface between the first thermoplastic resin layer 5 of a low viscosity and the second thermoplastic resin layer 6 of a high viscosity comes to be of a finely irregular mat state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automobile interiors, office automation equipment, housings for home appliances, etc.
The present invention relates to a method for producing a thermoplastic resin sheet which is used as a molded article such as stationery, sanitary goods, daily necessities, interior building materials, etc. and has an excellent matte feeling.

[0002]

2. Description of the Related Art A method of mechanically embossing the surface of a thermoplastic elastomer layer using an embossing roll in order to impart a leather-like matte feeling to the surface of a synthetic resin film (Japanese Patent Publication No. 14023/1989). Japanese Patent Laid-Open No. 3-269182), by mixing a thermoplastic resin with a particulate filler to form voids inside the resin layer and crushing the voids to obtain an uneven pattern (JP-A-3-269182). Also, a method of forming a coating film on the surface of a film with a matte coating obtained by adding a bead pigment to a radiation curable vehicle (JP-A-2-4)
No. 1243) is known.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method described in Japanese Patent No. 23, the transferability of the embossed pattern is poor, unevenness is likely to occur in wrinkles, a sufficient matte feeling cannot be obtained, and unevenness in wrinkles occurs due to uneven thickness of the sheet.
In the method described in JP-A-3-269182, the strength of the resin layer is lowered by the addition of the filler, and the appearance is deteriorated due to the blocking of the filler. In addition, JP-A-2
According to the method described in JP-A-41243, there is a drawback that the solvent used for the paint is scattered and the working environment is bad.

The present invention solves the above-mentioned problems of the prior art and provides a method for producing a thermoplastic resin sheet which can be subjected to a uniform graining process by a simple method and can obtain an excellent matte feeling. The purpose is to

[0005]

According to the method for producing a thermoplastic resin sheet of the present invention, the viscosity difference between the first thermoplastic resin and the first thermoplastic resin is 3000 poise or more, and If the viscosity ratio to the thermoplastic resin is 1.3 or more, 50
A second thermoplastic resin having a viscosity of 000 poise or less and having no adhesiveness to the first thermoplastic resin is coextruded with a residence time in the mold of 5 seconds or more and 60 seconds or less. After cooling by cooling, the second thermoplastic resin layer is peeled and removed.

Examples of the first and second thermoplastic resins used in the present invention include conventionally known ones. Examples thereof include low density polyethylene, high density polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyamide, Included are polystyrene, polyvinyl acetate, polyacrylonitrile, thermoplastic polyolefin elastomers, thermoplastic urethane elastomers and copolymers thereof. Among them, as the first thermoplastic resin, a thermoplastic urethane elastomer having excellent abrasion resistance and flexibility is used, and as the second thermoplastic resin, a thermoplastic polyolefin elastomer having excellent flexibility at the time of peeling is used. preferable.

The melt viscosity of the second thermoplastic resin used in the present invention is the shear viscosity at the temperature of the tip of the cylinder during molding, measured according to JIS K7199, and the melt viscosity is limited to 50,000 poises or less. It If the melt viscosity exceeds 50,000 poise, extrusion molding becomes difficult.

A first thermoplastic resin having a low viscosity,
The difference in melt viscosity from the second thermoplastic resin, which has a high viscosity, is 30.
Limited to over 100 poise. If the difference in melt viscosity is less than 3000 poise, the unevenness of the surface becomes rough and a matte feeling cannot be obtained sufficiently.

Further, the melt viscosity ratio of the second thermoplastic resin to the low-viscosity first thermoplastic resin is limited to 1.3 or more. If the melt viscosity ratio is less than 1.3, the surface irregularities become rough and a matte feeling cannot be obtained sufficiently.

The adhesive strength between the first thermoplastic resin and the second thermoplastic resin is such that the peel strength defined by JIS K7221 is 10 kgf or less. This peel strength is 10k
If the gf or more is used, the second thermoplastic resin cannot be removed, or even if it is possible, sufficient matte feeling cannot be obtained.

The coextrusion method used in the present invention is a method of simultaneously extruding a plurality of resin layers by a plurality of extruders and laminating the resin layers integrally, and for example, a method using a multi-manifold die, a method using a feed block die, etc. Can be mentioned. The residence time in the mold during coextrusion molding is limited to 5 seconds or more and 60 seconds or less. When the residence time in the mold is 5 seconds or less, the matte feeling is not sufficiently obtained, and when it exceeds 60 seconds, the productivity is deteriorated.

The resin temperature and the mold temperature at the time of coextrusion molding differ depending on the resin used, but generally 150 to 2
It is 50 ° C., and is appropriately adjusted depending on the melting behavior of the resin.

The thickness of the first and second thermoplastic resin layers is not particularly limited, but the ratio of the first thermoplastic resin layer / the second thermoplastic resin layer is preferably 5 or more. If this ratio is less than 5, the unevenness of the surface becomes insufficient and a matte feeling cannot be obtained sufficiently.

The method for removing the second thermoplastic resin layer according to the present invention is not particularly limited, and the first thermoplastic resin layer and the second thermoplastic resin layer are wound on separate winding rolls, respectively. The second thermoplastic resin layer may be recycled for use.

[0015]

A second thermoplastic resin having a viscosity difference of 3000 poises or more with the first thermoplastic resin, a viscosity ratio of 1.3 or more to the first thermoplastic resin, and a viscosity of 50,000 poises or less. , The first thermoplastic resin is co-extruded with a residence time in the mold of 5 seconds or more and 60 seconds or less, and therefore, at the interface between the first thermoplastic resin layer and the second thermoplastic resin layer. Has fine irregularities. Since the first thermoplastic resin and the second thermoplastic resin do not have adhesiveness to each other, the second thermoplastic resin layer can be peeled and removed after cooling the first thermoplastic resin and the first thermoplastic resin having a low viscosity. The peeled surfaces of the thermoplastic resin layer and the second thermoplastic resin layer having a high viscosity are in a matte state due to fine irregularities.

[0016]

[Raw material resin]

Resin 1: Thermoplastic urethane elastomer (manufactured by Nippon Miractolan, trade name: Miractolan E990P) Resin 2: Thermoplastic urethane elastomer (manufactured by Asahi Glass Co., Ltd.,
Trade name: U-Fine PN3429) Resin 3: Thermoplastic polyolefin-based elastomer (Mitsui Petrochemical Co., Ltd., trade name: Mirastomer 8030N) 50
Parts by weight, thermoplastic polyolefin elastomer (Mitsui Petrochemical Co., Ltd., Mirastomer 5030)
N) 30 parts by weight, linear low-density polyethylene (Mitsui Petrochemical Co., Ltd., trade name: UZ2921L) 10 parts by weight, polypropylene (Mitsui Petrochemical Co., Ltd., trade name: F650) 1
Mixture of 0 parts by weight Resin 4: Acid-modified polyethylene (Mitsui Petrochemical Co., Ltd., trade name: Admer QF551) Resin 5: Low density polyethylene (Mitsui Petrochemical Co., Ltd., trade name: Mirason 12)

FIG. 1 is an explanatory view for explaining an apparatus for producing the thermoplastic resin sheet of the present invention, and the apparatus and extrusion conditions will be described. 1 is a flow path of the first thermoplastic resin extruded from an extruder A (not shown), and the extruder A has a diameter of 4
0 mm, L / D = 26, compression ratio: 3 (Plastic Engineering Laboratory Co., Ltd., trade name: GT-40). 10
Is a flow path of the second thermoplastic resin extruded from the extruder B (not shown). The extruder B has a diameter of 50 mm and L / D = 2.
6, compression ratio: 3 (Plastic Engineering Laboratory Co., Ltd., trade name: GT-50). 3 is a die, 5
Equipped with a flow path feed block, width 500 mm, clearance 0.8 mm, land length 160 mm, land volume 3
It has a discharge port of 00 cm ³ (manufactured by Krollen, trade name: Epoch 3201).

A laminate of the first thermoplastic resin layer 5 and the second thermoplastic resin layer 6 coextruded from the die 2 passes through the cooling roll 3 and immediately after passing through the take-up roll 4, these resin layers. By peeling off 5 and 6, and winding up, the wound body 7 of the thermoplastic resin sheet made of the first thermoplastic resin is obtained. Reference numeral 8 is a second thermoplastic resin layer that is peeled off and wound up as a wound body.

Example 1 Using the apparatus shown in FIG. 1, a resin 1 (first thermoplastic resin) was extruded by an extruder A to give a resin 3
The (second thermoplastic resin) was coextruded by the extruder B under the following conditions. Residence time in mold: 27 seconds Extrusion temperature: (Cylinder tip) Extruder A; 220 ° C, Extruder B; 190 ° C, Mold; 200 ° C Discharge rate: 40 kg / hr (Extruder A; 6 kg / hr, Extruder B; 34 kg / hr) Cooling roll temperature: 60 ° C

The thickness 40 coextruded in this way
A layered product having a thickness of 0 μm (first thermoplastic resin layer 5; 350 μm, second thermoplastic resin layer 6; 50 μm) was taken at a speed of 5
No. 2 immediately after passing through the take-up roll 4 while taking off at m / min.
Of the first thermoplastic resin layer 5 by peeling off the thermoplastic resin layer 6 of
A wound body 7 of a thermoplastic resin sheet having a winding width of 400 mm was obtained. Reference numeral 8 is a second thermoplastic resin layer which has been peeled off.

FIG. 2 is an enlarged cross-sectional view of the above-mentioned coextrusion-molded laminate, and it is confirmed that fine irregularities 9 are formed at the interface between the first thermoplastic resin layer 5 and the second thermoplastic resin layer 6. Was done.

Example 2 Resin 1 was used as the first thermoplastic resin,
Extruder A and Extruder B with Resin 3 as Second Thermoplastic Resin
Co-extrusion molding was carried out under the same conditions as in Example 1 except that the temperature at the tip of each cylinder was 200 ° C.

(Example 3) Resin 2 is a first thermoplastic resin,
Co-extrusion molding was performed under the same conditions as in Example 1 except that the resin 3 was used as the second thermoplastic resin, the cylinder tip temperature of the extruder A was 230 ° C, and the cylinder tip temperature of the extruder B was 200 ° C.

(Example 4) Resin 1 is a first thermoplastic resin,
Co-extrusion molding was carried out under the same conditions as in Example 1 except that the resin 5 was the second thermoplastic resin, the temperature of the cylinder tip of the extruder A was 220 ° C, and the temperature of the cylinder tip of the extruder B was 180 ° C.

(Comparative Example 1) Resin 1 is a first thermoplastic resin,
Co-extrusion molding was performed under the same conditions as in Example 1 except that the resin 3 was used as the second thermoplastic resin, the cylinder tip temperature of the extruder A was 190 ° C, and the cylinder tip temperature of the extruder B was 200 ° C.

(Comparative Example 2) Resin 2 is a first thermoplastic resin,
Co-extrusion molding was performed under the same conditions as in Example 1 except that the resin 3 was the second thermoplastic resin and the temperature of the tip of the cylinder of the extruder B was 200 ° C.

(Comparative Example 3) Resin 1 is a first thermoplastic resin,
Co-extrusion molding was performed under the same conditions as in Example 1 except that the resin 4 was the second thermoplastic resin and the temperature of the cylinder tip of the extruder A was 200 ° C.

(Comparative Example 4) A resin 1 was extruded in a single layer under the following conditions using an extruder A and the die 2 described above, and then embossed with a texture roll. Residence time in mold: 27 seconds Extrusion temperature: Cylinder tip temperature 200 ° C, mold temperature 2
00 ° C Discharge rate: 40 kg / hr Cooling roll temperature: 60 ° C Pulling speed: 5 m / min Chevrolet roll temperature: 90 ° C Average grain size: 10 μm

(Comparative Example 5) A single layer of resin 5 was extruded using the extruder A and the die 2 under the same conditions as in Comparative Example 4. No embossing was performed.

The viscosities of the thermoplastic resins used in Examples 1 to 4 and Comparative Examples 1 to 5, the glossiness of the resulting thermoplastic resin sheets, and the peel strength were measured. The results are shown in Table 1.

[0031]

[Table 1]

[Note] * 1: Measured according to JIS K7199 * 2: Measured according to JIS Z8741 * 3: Measured according to JIS K7221

As can be seen from Table 1, in Examples 1 to 4, the second thermoplastic resin has a melt viscosity difference of 3000 poise or more and a viscosity ratio of 1.3 or more with respect to the first thermoplastic resin. As a result, a thermoplastic resin sheet having an excellent matte feeling was obtained. In Example 4, the peeled second thermoplastic resin layer also has low gloss on the peeled surface, and the second thermoplastic resin layer can be used as a sheet having a matte surface. It was

On the other hand, in Comparative Examples 1 to 3, since the second thermoplastic resin having a melt viscosity difference of less than 3000 poise or a viscosity ratio of less than 1.3 with respect to the first thermoplastic resin was used, A sheet with a good erase feeling could not be obtained. Further, in Comparative Examples 4 and 5, the single layer extrusion was followed by the embossing with the embossing roll, so that a sufficient matte feeling was not obtained.

[0035]

Since the first thermoplastic resin layer and the second thermoplastic resin layer are laminated by co-extrusion, the surface of the first thermoplastic resin layer after the second thermoplastic resin layer is peeled off is obtained. Due to the fine irregularities, a thermoplastic resin sheet having an even and excellent matte state can be obtained. Further, according to the method of the present invention, it is possible to obtain a uniform matte feeling by a simple method.

[0036]

[Brief description of drawings]

FIG. 1 is an explanatory view showing an apparatus for producing a thermoplastic resin sheet of the present invention.

FIG. 2 is an enlarged cross-sectional view of a laminated body.

[Explanation of symbols]

 1: Extruder A 10: Extruder B 2: Dice 3: Cooling roll 4: Take-up roll 5: First thermoplastic resin layer 6, 8: Second thermoplastic resin layer 7: Rolled body 9: Unevenness

Claims (1)

[Claims] 1. A viscosity difference between the first thermoplastic resin and the first thermoplastic resin is 3000 poise or more,
Viscosity ratio to thermoplastic resin of 1.3 or more, 500
A second thermoplastic resin having a viscosity of 00 poise or less and having no adhesion to the first thermoplastic resin is coextruded with a residence time in the mold of 5 seconds or more and 60 seconds or less. A method for producing a thermoplastic resin sheet, which comprises peeling and removing the second thermoplastic resin layer after cooling with cooling.