JPS5820973B2 - Molding resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding resin composition containing silica.

More specifically, the present invention relates to a molding resin composition containing an ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA), silica, and an epoxy resin as essential components.

Polyolefin resins such as EVA have excellent moldability, mechanical properties, and transparency, and can be used for films, sheets,
A wide range of products including blow molding and injection molding.

Used across a wide range of fields.

However, on the other hand, there are many problems such as poor dimensional stability, low heat distortion temperature, and creep.

As a method to improve this point, a method of filling with inorganic fillers such as calcium carbonate, curcum, clay, calcium silicate, mica, etc. is often adopted.

However, polyolefin resins filled with these inorganic fillers have poor mechanical properties, especially tensile strength and elongation.
Furthermore, it became opaque, and the transparency of polyolefin could not be utilized at all, making it impossible to use it for applications requiring transparency.

Furthermore, when filled with filler at a high concentration, the melt flowability is significantly reduced and molding becomes difficult, which is unsatisfactory, and an improvement has been strongly desired.

As a result of intensive research to improve the above drawbacks, the present inventors found that
Surprisingly, it was discovered that by filling BVA with silica and further adding an epoxy resin, a composition with excellent mechanical properties, transparency, moldability, etc. could be obtained, and the present invention was achieved.

Furthermore, the present invention has a distinctive feature of burning while maintaining its original shape without dripping, and in addition to the slow combustion effect of the filler, it is also highly suitable for construction materials, etc. be.

The present invention will now be described in detail.

The EVA used in the present invention is manufactured by any method such as high-pressure radical polymerization, solution or emulsion polymerization, has a vinyl acetate content of 1 to 60% by weight, and has a melt index of 0.1 to 40 ON/10H. is preferably used.

Outside this range, the mechanical properties, transparency, moldability, etc., which are the characteristics of the present invention, will be inferior.

-Next, the silica may be either wet hydrated silica represented by SiO2. Various types may be selected depending on the purpose of use.

Next, the epoxy resins include bisphenol A type, halogenated bisphenol type, resorcin type, bisphenol F type, tetraroxyphenylmethane type, novolak type, polyalcohol type, polyglycol type, glycerin triether type, polyolefin type, Examples include epoxidized soybean oil, and any of them can be used.

There is no problem even if a plurality of these are used in combination.

The quantitative ratio of BVA to silica and epoxy resin is BVA
It is desirable to mix silica in a range of 1 to 200 parts by weight and epoxy resin in a range of o, i to 50 parts by weight per 100 parts by weight.

If silica is added in an amount exceeding the upper limit of 200 parts by weight, the melt index of the composition will drop significantly, making it virtually impossible to process, and causing problems such as a decrease in mechanical strength.

Further, if the amount is less than 1 part by weight, the effect of adding the filler cannot be exhibited.

When epoxy resin is added in an amount exceeding 50 parts by weight, problems such as a decrease in mechanical strength and oozing of the epoxy resin onto the surface occur.

Moreover, if it is less than 0.1 part by weight, the effect of adding the epoxy resin is small.

The quantitative ratio of silica and epoxy resin desirably satisfies the following relational expression: X/10≦y≦X, where the weight part of silica is X and the epoxy resin is y.

Within this range, the effect of adding the epoxy resin, that is, the excellent properties such as mechanical strength, transparency, moldability, and combustibility, can be fully exhibited.

In producing the composition of the present invention, a single-screw or twin-screw kneading extruder, a roll, a Banbury mixer, etc. are effectively used for mixing and kneading.

The crosstalk temperature is selected between the melting point and decomposition temperature of EVA.

Specifically, the temperature is preferably 120°C or higher and 200°C or lower.

The kneading time varies depending on the kneading method, kneading temperature, etc.
The time required to obtain a uniform composition may be selected in each case.

The composition of the present invention may contain any known additives such as heat stabilizers, antioxidants, antiblock agents, slip agents, antistatic agents, colorants, and the like.

By supplying the composition of the present invention to a conventional injection molding machine, extrusion molding machine, calender molding machine, etc.
Can be formed into any shape such as sheet, film, pipe, rod, etc.

EXAMPLES Next, the present invention will be specifically explained using Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Examples 1 to 4, Comparative Examples I to ■ Melt index as EVA: 20 g/l 0 reviews,
The vinyl acetate content was 20% by weight, the Vicat softening point was 57°C, and the silica was N1psi manufactured by Nippon Silica.
1 LP, and Epikote 815 (bisphenol type) manufactured by Shell Chemical Co., Ltd. was used as the epoxy resin.

The mixing method uses a 6-inch roll and 100y of EVA
After melting, a predetermined amount of silica was added, and further a predetermined amount of epoxy resin was added, and crosstalk was performed at 150° C. for 10 minutes.

The resulting composition was subjected to a tensile test in accordance with ASTM D-638.

Transparency conforms to ASTM D-1003-61, l
The light transmittance and haze (haze value) of the IT-thick press plate were measured.

Next, for the flammability test, a strip-shaped test piece of 2ONN x 501411 was made from a 2'ILTI & thick press plate.
It was fixed vertically and burned, and the shape after combustion was judged.

◯: The shape is maintained even after combustion and there is no dripping.△2: The shape is partially dripped.×2: The shape is completely dripped and the shape is not maintained.The results are summarized in Table 1.

It can be seen that mechanical strength, transparency, processability, and combustibility are all significantly improved by adding the epoxy resin.

Examples 5 to 8, Comparative Examples ■ to ■ EVA melt index 18N / 10m1n1
The same operations as in Examples 1 to 4 were performed except that the vinyl acetate content was 28% by weight and the Vicat softening point was 43°C.

The results are shown in Table-2.

Examples 9 to 12 The same operations as in Examples 1 to 4 were performed except that the epoxy resin was changed to Epicor 1-1031 (tetrahydroxyphenylmethane type, manufactured by Shell Chemical).

The results are shown in Table-3.

Claims (1)

[Claims] 1. Melt index 0.1 to 400 g/10 mm. 1 to 200 parts by weight of silica and 0.1 to 50 parts by weight of epoxy resin per 100 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 1 to 60% by weight. molding resin composition.