JP2001002944A - Transparent resin composition and molded form thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition affording long-term high transparency and suitable for packaging films, agricultural films and general molded products. SOLUTION: This resin composition is obtained by compounding 99.989999-94.7 wt.% of a polyolefin-based resin such as polyethylene or polypropylene with a combination of 0.000001-0.3 wt.% of 2,5-bis[5-t-butylbenzoxazolyl(2)]thiophene known as a fluorescent brightening agent with 0.01-5.0 wt.% of a nucleating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition having excellent transparency over a long period of time.

[0002]

2. Description of the Related Art It is generally well known to add a nucleating agent to impart transparency to polyolefin resins and other plastics.

[0003]

However, the transparency of the existing nucleating agent is insufficient for some applications, and it is desired to further improve the transparency.

It is an object of the present invention to provide a resin composition having better transparency and a molded product thereof.

[0005]

As a result of intensive studies to solve the above problems, (a) a thermoplastic resin, (b) 2,
5-bis [5-t-butylbenzooxazolyl (2)]
The present inventors have found that a resin composition comprising thiophene and (c) a nucleating agent exhibits good characteristics, and have accomplished the present invention.

In such a composition, (a) a thermoplastic resin of 99.9989999 to 94.7% by weight,
(B) 0.000001 to 0.3% by weight of 2,5-bis [5-t-butylbenzooxazolyl (2)] thiophene and (c) 0.01 to 5.0% by weight of a nucleating agent. It is preferred that there be (claim 1).

In such a composition, the nucleating agent (c) is preferably an organic nucleating agent such as a sorbitol-based compound or a phosphate-based compound alone or in combination (claim 2).

In such a composition, the nucleating agent (c) is more preferably used alone or in combination of a high-purity methyl-substituted dibenzylidene sorbitol and a sodium phosphate compound (Claim 3).

In such a composition, the thermoplastic resin as the component (a) is a polyolefin resin such as polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polycarbonate, polyethylene terephthalate. A resin having transparency, such as an engineering plastic resin, is preferred.

In such a composition, as the thermoplastic resin as the component (a), polyolefin resins such as polypropylene, polyethylene, ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer are more preferable. (Claim 4).

In such a composition, the thermoplastic resin as the component (a) is more preferably a polypropylene resin such as homopolypropylene, block polypropylene or random polypropylene (claim 5).

[0012] By using the resin composition itself or a molding material containing the composition, various molded products such as sheets, films, and housings can be obtained. (Claim 6).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The typical and best modes of the embodiment of the present invention will be specifically shown in the examples described later. This will be described in detail.

In the resin composition of the present invention, (a) 99.9998999 to 94.7% by weight of a thermoplastic resin, and (b)
2,0001-0.3% by weight of 2,5-bis [5-tert-butylbenzooxazolyl (2)] thiophene,
(C) The nucleating agent is preferably 0.01 to 5.0% by weight. Here, when the component (b) is 0.000001% by weight or less or 0.3% by weight or more, a sufficient effect of improving transparency cannot be obtained as compared with the case where the nucleating agent is used alone. When the component (c) is 0.01% by weight or less or 5.0% by weight or more, a sufficient effect of improving transparency cannot be obtained.

Further, when high-purity methyl-substituted dibenzylidene sorbitol is used as the component (c), it is preferable that the amount of 0.1% be used.
It is more preferable that the content be from 0.01 to 1.0% by weight.

When a phosphate-based sodium compound is used as the component (c), 0.01 to 5.0.
Preferably, it is 0% by weight.

Examples of the thermoplastic resin used as the component (a) include transparent polyolefin resins such as polypropylene, polyethylene, ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer, polycarbonate, polyethylene terephthalate and the like. Although an engineering plastic resin can be used, a preferable example is a polyolefin resin.

As the polyolefin resin suitable as the component (a), a polypropylene resin such as homopolypropylene, random polypropylene and block polypropylene, which hardly bleeds, is most preferable. Further, in order to improve the cold resistance, flexibility, etc. of these polypropylenes, ethylene-propylene copolymers, styrene-
Compositions to which ethylene-polypropylene copolymer, styrene-butadiene-styrene copolymer and hydrogenated compounds thereof are added, and compositions to which various resins of polypropylene or polyethylene modified by maleic anhydride or the like are added are also preferable. It is.

In the resin composition of the present invention, it is possible to use the thermoplastic resin of the component (a) and to further increase the concentration of the components (b) and (c) in the ratio of claim 1. The master batch thus obtained can be used by adding it to a thermoplastic resin.

In the resin composition of the present invention, if necessary,
Phenolic, thioether and phosphorus antioxidants and heat stabilizers, stabilizers such as metal deactivators such as hydrazine compounds, and benzotriazole, benzophenone, benzoate and triazine UV absorbers A light stabilizer such as a hindered amine, a nucleating agent such as pt-butyl aluminum benzoate, an inorganic anti-blocking agent such as fine-particle silica, an organic anti-blocking agent such as fine-particle acrylic resin, a silicone-based release agent and Lubricants, dispersants such as metal soaps and fatty acid amides, antistatic agents such as surfactants, coloring agents such as dyes and organic and inorganic pigments, flame retardants such as phosphorus-containing flame retardants such as condensed phosphate esters, and the like. A flame retardant aid such as antimony oxide can be added.

[0021]

EFFECT OF THE INVENTION The resin composition of the present invention can be easily processed by extrusion molding such as T-die and inflation, injection molding and the like, and is excellent in transparency, so that it is used for packaging films for agricultural films, cosmetics, etc., and show windows. , Containers, building materials, etc. In addition, it can be used for a wider range of applications by combining with other materials (such as laminating).

[0022]

The present invention will now be described in detail with reference to Examples.
The present invention is not limited to the embodiments. The percentages in Examples and Comparative Examples are all based on weight.

Examples 1 to 10 and Comparative Examples 1 to 8 The components and the mixing ratios shown in Tables 1 to 6 were mixed by a tumbler, and then melt-kneaded with a 30 mmφ biaxial vent-type extruder, followed by pelletization. Next, by injection molding:
A sheet having a thickness of 20 mm was prepared. The evaluation of each characteristic was carried out by the following method, and the evaluation results are shown in Tables 1 to 6.

(1) Haze 1: JIS K 7105
Measure haze according to. (2) Haze 2: After leaving in an oven at 40 ° C. for 10 days,
Measure haze according to JIS K 7105.

As is clear from Tables 1 to 6, the haze is reduced and the transparency is improved by adding the nucleating agent. Further, by adding 2,5-bis [5-t-butylbenzooxazolyl (2)] thiophene, haze is reduced and more excellent transparency can be obtained.

The amount of 2,5-bis [5-tert-butylbenzooxazolyl (2)] thiophene added was 0.00000.
The content is preferably 1 to 0.3% by weight, and within this range, excellent transparency can be obtained. If it exceeds 0.4% by weight, the effect of addition cannot be obtained.

The nucleating agent for obtaining transparency is most preferably a high-purity methyl-substituted dibenzylidene sorbitol and a sodium phosphate compound.
The addition amount is preferably 0.01 to 1.0% by weight for high-purity methyl-substituted dibenzylidene sorbitol, and 0.01 to 5.0% by weight for sodium phosphate ester compounds. Similar effects can be obtained by using two nucleating agents in combination.

Description of Abbreviations in Table PP: Melt Index 4 (230 ° C., 2.
16 kg), homopolypropylene PE having a specific gravity of 0.91: melt index 3 (190 ° C., 2.
16 kg), low-density polyethylene OB having a specific gravity of 0.92: Ubitex OB (2,5-bis [5-t-butylbenzooxazolyl (2)] thiophene, manufactured by Ciba Specialty Chemicals) MD: Gel All MD (Shin Nippon Rika Co., Ltd.,
High purity methyl-substituted dibenzylidene sorbitol) NA: Adekastab NA-21 (manufactured by Asahi Denka Kogyo Co., Ltd., a mixture containing a phosphate ester-based sodium compound as a main component) AL: Al-PTBBA (manufactured by Shell Co., Ltd., p
-T-butyl aluminum benzoate)

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

[Table 6]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08K 5/521 C08K 5/521 C08L 23/00 C08L 23/00 23/12 23/12 23/12

Claims (6)

[Claims] 1. (a) a thermoplastic resin 99.9989999
９４94.7% by weight, (b) 2,5-bis [5-tert-butylbenzooxazolyl (2)] thiophene 0.0000
A resin composition comprising from 0.01 to 0.3% by weight and (c) from 0.01 to 5.0% by weight of a nucleating agent. 2. The resin composition according to claim 1, wherein (c) the nucleating agent is an organic nucleating agent such as a sorbitol-based compound or a phosphate-based compound, alone or in combination. 3. The resin composition according to claim 1, wherein (c) the nucleating agent is a high purity methyl-substituted dibenzylidene sorbitol and a sodium phosphate ester compound alone or in combination. 4. The resin composition according to claim 1, wherein (a) the thermoplastic resin is a polyolefin. 5. The resin composition according to claim 1, wherein (a) the thermoplastic resin is polypropylene. 6. A molded article using the resin composition according to claim 1.