JP2000094603A - Manufacture of laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated film which has outstanding pliability, transparency and glossiness and does not cause environmental contamination. SOLUTION: A propylene resin composition (a) composed of 100 pts.wt. resin content comprising 100-10 wt.% prolylene resin and 0-90 wt.% vinyl aromatic elastomer and 0.05-0.1 wt.% crystalline nucleus-forming agent and a propylene resin composition (b) comprising 97-10 wt.% propylene resin and 3-90 wt.% vinyl aromatic elastomer, are co-extruded so that the layer composed of the propylene resin composition (a) becomes an outermost layer, by a T-die process or a downward water-cooled inflation process, the co-extruded resin material is processed into a film at 30-70 deg.C cooling temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a laminated film.

[0002]

2. Description of the Related Art Polymer resin films are used for packaging various articles such as textiles, clothing, bread, noodles, toilet paper, and the like, and are particularly used for applications requiring high transparency, high gloss, flexibility, and the like. Uses a soft vinyl chloride resin film. However, since a soft vinyl chloride resin film contains a large amount of a plasticizer, there is an environmental problem, and a propylene-based resin film has recently been used.

As the propylene-based resin film, a stretched propylene-based resin film containing a crystal nucleating agent is used, but has drawbacks in that it has high rigidity, low flexibility, and is liable to be wrinkled.

In order to solve such disadvantages, Japanese Patent Laid-Open Publication No. Hei 7-290649 proposes a laminated film in which a random polypropylene layer is laminated on both sides of an intermediate layer composed of random polypropylene and a hydrogenated diene copolymer. However, this laminated film has a disadvantage that it has excellent flexibility but low glossiness.

An object of the present invention is to provide a method for producing a laminated film which is excellent in flexibility, transparency and gloss and has no environmental pollution in view of the above-mentioned drawbacks.

[0006]

According to the present invention, there is provided a method for producing a laminated film, comprising a resin component comprising 100 to 10% by weight of a propylene resin and 0 to 90% by weight of a vinyl aromatic elastomer, and a crystal nucleating agent. A propylene-based resin composition (a) consisting of 0.005 to 0.1 parts by weight, a propylene-based resin composition (b) consisting of 97 to 10% by weight of a propylene-based resin and 3 to 90% by weight of a vinyl aromatic elastomer are prepared. Co-extrusion is performed by a T-die method or a downward water-cooled inflation method so that a layer made of the propylene-based resin composition (a) becomes the outermost layer, and a film is formed at a cooling temperature of 30 to 70 ° C.

The propylene resin used in the present invention is:
Generally, a commercially available propylene-based resin can be used, and when ethylene is copolymerized, flexibility, transparency and the like are excellent, which is preferable. Is preferred.

The vinyl aromatic elastomer used in the present invention is obtained by copolymerizing a vinyl aromatic compound (A) and a conjugated diene (B) with A- (BA) _m (m is 1 or more). A block copolymer or a random copolymer represented by (AB represents an integer of 1 or more) or (AB) _n (n represents an integer of 1 or more), or a hydrogenated product of these copolymers. BA-type and AB-type copolymers are preferred.

The vinyl aromatic compound includes, for example, styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, 1,1-diphenylstyrene and the like, and styrene and α-methylstyrene are preferred. Examples of the conjugated diene include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 2-methyl-1,3-
Examples thereof include pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, and chloroprene, and 1,3-butadiene and isoprene are preferred.

As the vinyl aromatic elastomer, a styrene-butadiene random copolymer, a styrene-isoprene-styrene block copolymer and a hydrogenated product thereof are preferable. As the hydrogenated product of the styrene-isoprene-styrene block copolymer, a styrene-ethylene-propylene-styrene copolymer and a hydrogenated styrene-isoprene-styrene block copolymer having 3,4 isoprene bonds are particularly preferable.

The crystal nucleating agent used in the present invention may be any as long as it has a nucleating effect on the propylene resin. For example, a metal salt of an organic carboxylic acid, benzaldehyde or a ring-substituted product thereof and a polyhydric alcohol may be used. Condensates, polymer nucleating agents and the like can be mentioned.

Examples of the metal salts of the above organic carboxylic acids include sodium and potassium salts of benzoic acid and para-t
Aluminum salts of -butylbenzoic acid. Examples of the condensate of the above benzaldehyde or a ring-substituted product thereof with a polyhydric alcohol include, for example, dibenzylidene sorbitol, dibenzylidene xylitol, dibenzylidene passitol, monobenzylidene sorbitol, dibenzylidene mannitol, 1,3-di (alkylbenzylidene) Sorbitol, 2,4-di (alkylbenzylidene) sorbitol, 1,3-di (alkoxybenzylidene) sorbitol, 2,4-di (alkoxybenzylidene) sorbitol, alkyl-substituted benzylidenesorbitol and the like.

Examples of the polymer nucleating agent include vinylcycloalkanes such as vinylcyclohexane and vinylcyclopentane, alkyl-substituted styrenes such as pt-butylstyrene and p-methylstyrene, and 3-methylbutene-1,4,4. 4-dimethylpentene-1,4,4-dimethylhexene-1,3,3-dimethylbutene-1,3-methylpentene-1,3-methylhexene-1,3,5
Examples thereof include polymers such as 5-trimethylhexene-1, indene, trialkylallylsilane, and vinylcycloalkene.

The propylene resin composition (a) used in the present invention comprises 100 parts by weight of a resin component comprising 100 to 10% by weight of a propylene resin and 0 to 90% by weight of a vinyl aromatic elastomer, and a crystal nucleating agent. It consists of 0.005 to 0.1 parts by weight.

The ratio of the propylene resin to the vinyl aromatic elastomer in the above resin component is such that when the ratio of the vinyl aromatic elastomer decreases, the flexibility decreases, and when the ratio increases, the transparency and gloss decrease. The content of the resin is 100 to 10% by weight, and the content of the vinyl aromatic elastomer is 0 to 90% by weight.

On the other hand, when the amount of the crystal nucleating agent is small, the transparency and gloss are reduced, and when the amount is large, the rigidity is improved and the flexibility is reduced.
0.5 to 0.1 parts by weight are added.

In the propylene resin composition (b) used in the present invention, the flexibility decreases as the ratio of the vinyl aromatic elastomer decreases, and the transparency and gloss decrease as the ratio increases. 97 to 10% by weight,
It is composed of 3 to 90% by weight of a vinyl aromatic elastomer.

The resin compositions (a) and (b) may further contain a lubricant, an antiblocking agent, a plasticizer, a light stabilizer, an antioxidant, a coloring agent, A property improver, an antistatic agent, an ultraviolet absorber and the like may be added as necessary.

In the present invention, the propylene-based resin composition (a) and the propylene-based resin composition (b) are converted to a layer comprising the propylene-based resin composition (a) by a T-die method or a downward water-cooled inflation method. Coextrusion is performed so as to form an outer layer, and a film is formed at a cooling temperature of 30 to 70 ° C.

That is, the resin compositions (a) and (b) are kneaded in a heated and molten state using a kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneading roll, a brabender, or a kneader. Coextrusion is performed using a conventional extrusion molding machine by a T-die method or a downward water-cooled inflation method, and the film is formed by cooling at a cooling temperature of 30 to 70C.

When the cooling temperature is lowered, precipitates are liable to precipitate on the roll, and the physical properties are easily changed over time. When the cooling temperature is increased, the effect cannot be obtained.
The film is formed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples.

Example 1 100 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 min, and a styrene-isoprene-styrene block copolymer having isoprene 3, 4 bonded thereto (manufactured by Kuraray Co., Ltd., Hypla VS-1, containing styrene) 20%, MFR
5) 3 parts by weight and dibenzylidene sorbitol 0.02
Resin composition (a) consisting of parts by weight and MFR 6.0 g / 1
Styrene-isoprene-styrene block copolymer (100 parts by weight of random copolymerized propylene resin for 0 minute and isoprene 3,4 bond (manufactured by Kuraray Co.,
1. A resin composition (b) consisting of 10 parts by weight of styrene content 20% and MFR 5) was kneaded at 210 ° C. for 10 minutes, and then subjected to T-die method at a mold temperature of 230 ° C. and a cooling roll temperature of 45 ° C. Extruded to obtain a three-layer laminated film having a thickness of 40 μm. The laminated film was a three-layer film in which layer a was laminated on both sides of layer b, and the thickness ratio was 1: 5: 1.

Examples 2 to 4 A styrene-isoprene-styrene block copolymer having isoprene 3,4 bonds (manufactured by Kuraray Co., Ltd., Hypla VS-
1, a styrene content of 20%, MFR 5) was replaced with a hydrogenated styrene-isoprene-styrene block copolymer having isoprene 3,4 bonds (manufactured by Kuraray Co., Ltd., Hypla HVS)
-3, styrene content 20%, MFR6) (Example 2), hydrogenated styrene-butadiene random copolymer (Dynalon 1320P, manufactured by Nippon Synthetic Rubber Co., Ltd., styrene content 10%, MFR 3.5) (Example 3) ) And styrene
Ethylene-propylene-styrene block copolymer (manufactured by Kuraray Co., Ltd., Septon 2007, styrene content 30%,
MFR7) A laminated film having the same configuration as the laminated film obtained in Example 1 was obtained in the same manner as in Example 1 except that (Example 4) was used.

Example 5 A hydrogenated styrene-isoprene-styrene block copolymer having 100 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 min and isoprene 3,4 bonded (manufactured by Kuraray Co., Ltd., Hypla HVS-3, Styrene content 20%, M
FR6) 3 parts by weight and 0.1 g of dibenzylidene sorbitol.
Resin composition (a) consisting of 02 parts by weight and MFR 6.0 g
Resin composition (a ') comprising 100 parts by weight of a random copolymerized propylene resin / 10 minutes and 0.015 parts by weight of dibenzylidene sorbitol, 100 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 minutes and 3 parts of isoprene. , 4-bonded hydrogenated styrene-isoprene-styrene block copolymer (manufactured by Kuraray Co., Ltd., Hypla HVS-
3, a resin composition (b) consisting of 20 parts by weight of styrene and 10 parts by weight of MFR 6) was prepared in the same manner as in Example 1 except that the resin compositions (a) and (a ') were used as outer layers. A laminated film having the same configuration as the laminated film obtained in Example 1 was obtained.

Example 6 100 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 min and a hydrogenated styrene-isoprene-styrene block copolymer having isoprene 3,4 bonded (Hypla HVS-3, manufactured by Kuraray Co., Ltd.) Styrene content 20%, M
FR6) 4 parts by weight and dibenzylidene sorbitol 0.
Resin composition (a) consisting of 02 parts by weight and MFR 6.0 g
Hydrogenated styrene-isoprene-styrene block copolymer in which 100 parts by weight of random copolymerized propylene resin and isoprene are bonded in 3,4 minutes (manufactured by Kuraray Co., Ltd., Hypla HVS-3, styrene content 20%, MFR6) 10
After kneading the resin composition (b) consisting of parts by weight at 210 ° C. for 10 minutes, water-cooled inflation method was used.
Co-extrusion at a mold temperature of 230 ° C and a cooling roll temperature of 45 ° C,
A three-layer laminated film having a thickness of 40 μm was obtained. The laminated film was a three-layer film in which layer a was laminated on both sides of layer b, and the thickness ratio was 1: 5: 1.

Comparative Example 1 The same structure as the laminated film obtained in Example 2 was carried out in the same manner as in Example 2 except that the resin composition (b) was a random copolymerized propylene resin having an MFR of 6.0 g / 10 min. Was obtained.

Comparative Example 2 Resin composition (b) was prepared by adding 5 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 min and isoprene containing 3,4.
Example 2 was repeated in the same manner as in Example 2 except that the combined hydrogenated styrene-isoprene-styrene block copolymer (manufactured by Kuraray Co., Ltd., Hypla HVS-3, styrene content 20%, MFR6) was 95 parts by weight. A laminated film having the same configuration as the obtained laminated film was obtained.

COMPARATIVE EXAMPLE 3 A resin composition (a) was prepared by adding 5 parts by weight of a random copolymerized propylene resin having an MFR of 6.0 g / 10 min, and a hydrogenated styrene-isoprene-styrene block copolymer having isoprene 3,4 bonds (Kuraray Co., Ltd.) The same as the laminated film obtained in Example 2 in the same manner as in Example 2, except that Hypla HVS-3, styrene content 20%, MFR 6) was 95 parts by weight and dibenzylidene sorbitol was 0.02 part by weight. A laminated film having the structure was obtained.

Comparative Example 4 A resin composition (a) was prepared in the same manner as in Example 2 except that the amount of dibenzylidene sorbitol added was 0.3 parts by weight.
A laminated film having the same configuration as the laminated film obtained in Example 2 was obtained. Comparative Example 5 The laminated film obtained in Example 2 was prepared in the same manner as in Example 2 except that the addition amount of dibenzylidene sorbitol of the resin composition (a) was set to 0 parts by weight and the cooling roll temperature was set to 55 ° C. A laminated film having the same configuration was obtained.

Comparative Example 6 A laminated film having the same structure as the laminated film obtained in Example 2 was obtained in the same manner as in Example 2 except that the cooling roll temperature was changed to 90 ° C.

Comparative Example 7 In the same manner as in Example 2 except that the addition amount of dibenzylidene sorbitol in the resin composition (a) was changed to 0.07 parts by weight and the temperature of the cooling roll was set to 15 ° C. Although a laminated film having the same configuration as that of the obtained laminated film was obtained, precipitates were precipitated and physical properties could not be measured.

The films obtained in Examples and Comparative Examples were subjected to evaluation tests for the following evaluation items by the following methods, and the results are shown in Table 1. (1) Transparency: Evaluated by measuring haze (JIS K7105). (2) Gloss: Evaluated by measuring gloss (JIS K7105). (3) Flexibility: Evaluated by measuring elastic modulus (JIS K7133).

[0034]

[Table 1]

[0035]

As described above, the structure of the method for producing a laminated film of the present invention is as described above. Therefore, a propylene-based resin film having excellent flexibility, glossiness, transparency and the like can be easily produced. Can be suitably used as a packaging film. Further, since it does not need to contain a plasticizer and is excellent in environmental properties, it can be suitably used for a soft vinyl chloride film.

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Claims (2)

[Claims] 1. A resin component comprising 100 to 10% by weight of a propylene resin and 0 to 90% by weight of a vinyl aromatic elastomer, and 100 to 5% by weight of a crystal nucleating agent.
A propylene-based resin composition (a) consisting of parts by weight, a propylene-based resin composition (b) consisting of 97 to 10% by weight of a propylene-based resin and 3 to 90% by weight of a vinyl aromatic elastomer are subjected to a T-die method or downward water-cooled inflation. A method for producing a laminated film, comprising co-extrusion and forming a film at a cooling temperature of 30 to 70 ° C by a method so that a layer made of the propylene-based resin composition (a) becomes the outermost layer. 2. The method for producing a laminated film according to claim 1, wherein the vinyl aromatic elastomer is a hydrogenated styrene-butadiene random copolymer or a hydrogenated styrene-isoprene-styrene block copolymer.