JPH06192515A - Resin composition for molding - Google Patents

Abstract

PURPOSE:To provide a molding resin composition having excellent transparency, tear resistance, adhesivity, etc., and suitable for forming film or sheet. CONSTITUTION:The molding resin composition is composed of (A) 99-5wt.% of a block copolymer having a styrenic monomer content of 50-95wt.% and containing at least two polymer blocks composed mainly of styrenic monomer and at least one polymer block composed mainly of conjugated diene monomer, (B) 1-95wt.% of a graft copolymer having a vinyl monomer content of 10-95wt.% and produced by grafting a vinyl monomer to a hydrogenated block copolymer and/or an olefinic resin having a styrenic monomer content of 10-95wt.% and containing at least two polymer blocks composed mainly of styrenic monomer and at least one polymer block composed mainly of conjugated diene monomer and (C) 0-50wt.% of a polystyrene resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding resin composition suitable for molding a film or sheet and having excellent transparency, tear resistance and adhesiveness.

[0002]

2. Description of the Related Art Generally, styrene resin is easy to mold,
Due to its excellent transparency, water resistance and surface gloss, it is widely used in various packaging materials, containers and molded products. However, the styrene resin, when formed into a film, a sheet, or the like, has the drawbacks of being hard, having a low tear strength, and being poor in flexibility and adhesiveness.

As a method for improving these drawbacks, a styrene-diene-styrene block copolymer having a high styrene content has been developed, but it is insufficient in tear resistance and adhesiveness. Furthermore, as another improvement method,
Attempts have been made to improve the physical properties by blending the block copolymer with an impact-resistant polystyrene resin obtained by graft-polymerizing styrene to polybutadiene, but the performance is insufficient and the transparency is lost. I don't get it.

[0004]

DISCLOSURE OF THE INVENTION The present invention comprises a molding resin composition suitable for molding a film, a sheet or the like, which is excellent in transparency, tear resistance and adhesiveness, and a resin composition molded from the molding resin composition. The purpose is to provide films and sheets. The present inventors have conducted extensive studies on a molding resin composition having excellent transparency, tear resistance, adhesiveness, etc. suitable for molding a film or sheet,
(A) Styrene-conjugated diene-styrene block copolymer having a high styrene monomer content, and (B) hydrogenated styrene conjugated diene block copolymer and / or a graft obtained by grafting a vinyl monomer onto an olefin resin. The present invention was completed by reaching a resin composition containing a copolymer and, if necessary, (C) polystyrene resin in a specific ratio.

[0005]

That is, the present invention provides the following (A) component 99 to 5% by weight, and (B) component 1 to 95% by weight.
And a resin composition for molding comprising 0 to 50% by weight of the component (C). (A) contains at least two polymer blocks mainly composed of styrene-based monomers and at least one polymer block mainly composed of conjugated diene monomers, and has a styrene-based monomer content of 50 to 95% by weight of a block copolymer (B) containing at least two polymer blocks mainly composed of a styrene-based monomer and at least one polymer block mainly composed of a hydrogenated conjugated diene monomer, A hydrogenated block copolymer having a styrene-based monomer content of 10 to 95% by weight and / or a graft copolymer obtained by grafting a vinyl monomer onto an olefin resin and having a vinyl monomer content of 10%. Graft Copolymer (C) Polystyrene-based Resin Containing ˜95% by Weight Further, the present invention provides a film and a sheet comprising the molding resin composition.

The present invention will be described in detail below. In the present invention, as the block copolymer constituting the component (A), at least two polymer blocks mainly containing a styrene-based monomer and at least one polymer block mainly containing a conjugated diene monomer are used. The content of the styrene-based monomer is 50 to 95% by weight, preferably 60 to 90% by weight.
Is used for the block copolymer.

Regarding the polymer structure of the block copolymer, the block portion may include a tapered portion, and for example, a linear or radial star block copolymer can be used.

As a method for producing the block copolymer, a usual solution polymerization method using alkyllithium as a catalyst is used.
Further, a method of producing a star block copolymer using a coupling agent or the like is also used.

Examples of the styrene-based monomer include styrene, α-methylstyrene and various alkyl-substituted styrenes, and examples of the conjugated diene monomer include butadiene and isoprene.

When the content of the styrene-based monomer exceeds 95% by weight, it becomes a hard and brittle resin, and 50% by weight.
If it is less than the above range, the elasticity peculiar to the styrene resin is lost and it is not practical.

Specific examples of the block copolymer include:
A styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer and the like are preferable, and a mixture of two or more block copolymers can also be used.

The hydrogenated block copolymer constituting the component (B) comprises at least two polymer blocks mainly composed of styrene-based monomers and a polymer block mainly composed of hydrogenated conjugated diene monomers. The content of at least one styrene monomer is 10 to 95% by weight, preferably 50 to
A hydrogenated block copolymer which is 85% by weight is used.

The polymer structure of the block copolymer is not limited, and for example, linear or radial star block copolymers can be used.

As the styrene-based monomer, the above-mentioned (A) is used.
The monomer used for the component is used. Examples of the hydrogenated conjugated diene monomer include hydrides such as butadiene and isoprene, and the double bond derived from the conjugated diene component is preferably 80% or more saturated.

When the content of the styrenic monomer exceeds 95% by weight, the resin becomes hard and brittle, and 10% by weight.
When it is less than 1, the compatibility with the component (A) becomes poor, so that the resin composition or the molded product becomes cloudy, which is not practical.

In particular, the content of styrene-based monomer is 40 to
The hydrogenated block copolymer of 85% by weight is preferable in terms of transparency of the resin composition.

In the present invention, the hydrogenated block copolymer constituting the component (B) imparts appropriate tear resistance, flexibility and adhesiveness to the resin composition.

As the hydrogenated block copolymer, specifically, hydrogenated products of styrene-butadiene-styrene block copolymer and styrene-isoprene-styrene block copolymer are preferable.

The graft copolymer constituting the component (B) is a graft copolymer obtained by grafting a vinyl monomer onto an olefin resin as a trunk polymer, and the content of the vinyl monomer is 10 to 10. It is 95% by weight, preferably 40 to 85% by weight.

Examples of the method for producing the graft copolymer include the method described in JP-A-1-138214. When the graft copolymer is observed with an electron microscope, it has a sea / island structure composed of a graft product of an olefin resin and a vinyl monomer.

Examples of the olefin resin used include ethylene homopolymer, propylene homopolymer, ethylene-α-olefin copolymer (ethylene-butene copolymer, etc.), ethylene and glycidyl (meth) acrylate copolymer. Polymer, ethylene and (meth) acrylic acid ester copolymer, ethylene and vinyl ester copolymer, ethylene-
Examples thereof include propylene copolymer rubber and ethylene-propylene-diene copolymer rubber. The molecular weight of these olefin-based resins may be such that they are used in ordinary molding processing.

Examples of vinyl monomers include styrene monomers and (meth) acrylic acid ester monomers.

Examples of the styrene-based monomer include styrene and α
-Methylstyrene and various alkyl-substituted styrenes are preferable, and as the (meth) acrylic acid ester monomer,
An alkyl ester of (meth) acrylic acid having 1 to 8 carbon atoms is preferable. Particularly preferred monomers are styrene and methyl methacrylate.

In the present invention, when improving the moldability and adjusting the hardness of the resin composition, a polystyrene resin is optionally used as the component (C) in an amount of 0 to 50% by weight.
Can be used.

Specific examples of the polystyrene resin include a styrene homopolymer or a copolymer of styrene and a monomer copolymerizable with styrene.

Specifically, polystyrene, styrene-
Examples thereof include methyl (meth) acrylate copolymer, styrene-α-methylstyrene copolymer, and blends of these resins. Particularly preferred is polystyrene.

The ratio of each component constituting the molding resin composition of the present invention is such that (A) component is 99 to 5% by weight, and (B) component 1
-95 wt% and component (C) 0-50 wt%,
Preferably (A) component 97 to 55% by weight (B) component 3 to
45% by weight and 0 to 40% by weight of component (C).

If the content of the component (A) exceeds 99% by weight, tear resistance and adhesiveness cannot be obtained, and if it is less than 5% by weight, the processability of the composition deteriorates, making it difficult to form films and sheets. Become. On the other hand, if the content of the component (C) exceeds 50% by weight, the tear resistance of the formed film and sheet is lowered.

Constituting the resin composition of the present invention (A)
The molecular weight of each resin of the component (C) may be similar to that of the general molding resin.

The melt index, which is a measure of workability, is JIS K-6871, temperature 200 ° C., load 5 kg.
The value measured according to 1. is preferably 0.01 to 300, particularly preferably 0.1 to 150.

Further, the molding resin composition of the present invention may contain general additives such as pigments, antioxidants, lubricants and ultraviolet absorbers, if necessary.

The method for producing the molding resin composition of the present invention is such that the above-mentioned components (A) to (C) are blended in a predetermined ratio, and a commonly used Henschel mixer or tumbler is used. May be dry blended using a mixer, or kneaded by a screw extruder,
It may be a pelletized compound. In addition, in the production of the resin composition, there is no particular limitation on the order of addition of the components (A) to (C).

The molding resin composition of the present invention is suitable for single-layer and multi-layer film or sheet extrusion molding, but can also be used for various molding methods such as injection molding and blow molding.

As a film or sheet extrusion molding method, for example, a T-die method, an inflation method or the like can be used. Furthermore, in order to improve the film or sheet performance,
A uniaxial or multiaxial stretching method or the like can be used.

The film or sheet of the present invention is usually 1
Although it has a thickness of up to 2000 μm, the formed film or sheet has excellent transparency, tear resistance, adhesiveness and the like, and thus can be used as various packaging and containers. The film or sheet of the present invention may be laminated with another thermoplastic resin flim or sheet, for example, a film or sheet obtained by molding polyester, nylon polypropylene, polyethylene, polystyrene by using a thermal lamination method and an adhesive. You can

The parts manufactured by injection molding are used for electric / electronic parts, automobiles, interior / exterior parts and housings.

In the following, more detailed description will be given with reference to Examples and Comparative Examples. Example 1 As component (A) resin, styrene-butadiene-styrene block copolymer resin (trade name "Clearene", styrene content 80% by weight, MFI = 8.5, manufactured by Denki Kagaku Kogyo Co., Ltd.), (B) A resin composition containing hydrogenated styrene-isoprene-styrene block copolymer resin (trade name "Septon", 65% by weight of styrene, MFI = 22.0, manufactured by Kuraray Co., Ltd.) as a component resin in the proportion shown in Table 1. Were mixed uniformly with a Henschel mixer and pelletized with a biaxial kneader. Next, this pellet is 40m / m
Using an extruder (L / D = 28), extrusion molding was performed by an inflation method with a blow ratio of 3.0 to obtain a film having a thickness of 50 μm. Various evaluation tests were conducted on this film. The results are shown in Table 1.

Example 2 A film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that the blending ratio was changed and the film was formed by the T-die method. The evaluation results are shown in Table 1.

Example 3 In Example 1, as the component (B) resin, hydrogenated styrene-butadiene-styrene block copolymer resin (butadiene hydrogenation rate 98%, styrene content 70% by weight, MFI = 16. 0) was used and the ratio of the resin composition was changed. The results are shown in Table 1.

Example 4 Example 4 was repeated except that the amount of the blending ratio was changed. The results are shown in Table 1.

Example 5 In Example 1, as the component (B) resin, a graft copolymer resin obtained by grafting styrene on low density polyethylene (trade name "Modeper A", styrene content 70% by weight, MFI = 5. (2, manufactured by NOF CORPORATION) was used, except that the resin composition ratio was changed. The evaluation results are shown in Table 1.

Example 6 In Example 2, as the component (A) resin, styrene-
Butadiene-block-shaped block copolymer resin (styrene content 85% by weight, MFI = 10.5)
As a component (B) resin, a graft copolymer (trade name “Modeper A”, methyl methacrylate) in which ethylene-vinyl acetate copolymer (vinyl acetate content 20% by weight) is graft-polymerized with methyl methacrylate. Using a content of 65% by weight, MFI = 4.8, manufactured by NOF CORPORATION, the procedure was the same as above except that the ratio of the resin composition was changed to obtain a sheet having a thickness of 300 μm. The evaluation results are shown in Table 1.

Example 7 In Example 1, the mixing ratio of the component (A) resin and the component (B) resin was changed, and as the component (C), a polystyrene resin (trade name "Dencastyrol HRM", MFI =
3.2, manufactured by Denki Kagaku Kogyo Co., Ltd.) was used. The evaluation results are shown in Table 1.

Example 8 In Example 7, as component (B) resin, hydrogenated styrene-butadiene-styrene block copolymer resin (butadiene hydrogenation rate 98%, styrene content 40% by weight, MFI = 3. The same procedure was performed except that 5) was used and the ratio of the resin composition was changed. The evaluation results are shown in Table 1.

Example 9 Two-layer coextrusion molding was carried out using two 40 mmφ extruders, a feed block die, and a coat hanger type T-die having a width of 600 mm and a slit width of 0.4 mm. The resin composition used in Example 2 was used for the front surface layer, and a polypropylene resin (trade name “HIPOL”, manufactured by Mitsui Petrochemical Co., Ltd., MFI = 3.
7) was used. The obtained two-layer film has a front surface layer of 40 μm and a rear surface layer 2 by adjusting the extrusion amount of an extruder.
Each thickness was 0 μm. Table 1 shows various evaluation results of the two-layer film.

The compounding ratios of A and B shown in the column of resin composition in Table 1 represent the compounding amounts of the resin composition of the present invention used in the surface layer.

Comparative Example 1 In Example 1, the resin (B) was not used, but the resin (A) was used.
The same procedure was performed except that only the component resins were used. The results of the evaluation test are shown in Table 1.

Comparative Example 2 In Example 1, the resin (A) was not used, but the resin (B) was used.
The same procedure was performed except that only the component resins were used. The surface of the obtained film had severe irregularities, and an evaluable film could not be obtained.

[0049]

[Table 1]

Resin composition A: The compounding amount (kg) of the component (A) resin is shown. B: The blending amount (kg) of the component (B) resin is shown. C: Indicates the compounding amount (kg) of the component (C) resin.

Evaluation of Physical Properties Appearance: The film was visually evaluated. ○: No pinholes, tears, spots, streaks, irregularities, etc. ×: Any one of pinholes, tears, spots, lines, and irregularities. Thickness: The film and the sheet are measured using a peacock thickness gauge with a scale of 1/1000 mm. Breaking strength; Breaking elongation: Measured according to JIS Z-1702. The upper row shows the extrusion flow direction, and the lower row shows the value in the direction perpendicular to the extrusion flow.

Tear strength: Measured according to JIS K-6732. Light transmittance: Measured according to JIS K-7105. Adhesiveness: 100 μm created using polypropylene resin (trade name “HIPOL” manufactured by Mitsui Petrochemical Co., Ltd.)
Using a heat sealer for the polypropylene film of, the pressure of the film is 5 to 10 kg / cm ² , the sealing temperature is 200 ° C.,
Sealing was performed under a sealing condition of a sealing time of 5 seconds, and a peeling test was carried out using a 25 mm wide test piece. A film having a strong adhesive force and a film ruptured was marked with ◯, and the others were marked with x.

[0053]

As described above, according to the present invention,
It is possible to obtain a molding resin composition having excellent transparency, tear resistance and adhesiveness, which is suitable for molding a film or sheet. Moreover, the film and sheet obtained by molding the resin composition are excellent in transparency, tear resistance and adhesiveness.

Claims (3)

[Claims] 1. A molding resin composition comprising 99 to 5% by weight of the following component (A), 1 to 95% by weight of the component (B) and 0 to 50% by weight of the component (C). (A) contains at least two polymer blocks mainly composed of styrene-based monomers and at least one polymer block mainly composed of conjugated diene monomers, and has a styrene-based monomer content of 50 to 95% by weight of a block copolymer (B) containing at least two polymer blocks mainly composed of a styrene-based monomer and at least one polymer block mainly composed of a hydrogenated conjugated diene monomer, A hydrogenated block copolymer having a styrene-based monomer content of 10 to 95% by weight and / or a graft copolymer obtained by grafting a vinyl monomer onto an olefin-based resin having a vinyl monomer content of 10 to 95% by weight of graft copolymer (C) polystyrene resin 2. A film formed by extrusion molding the molding resin composition according to claim 1. 3. A sheet formed by extrusion-molding the molding resin composition according to claim 1.