JPH0413769A - Flowability improver and its composition - Google Patents

Abstract

PURPOSE:To obtain a fluidity-improving agent composed of a specific cyclic polydialkylsiloxane compound and useful for giving a composition having improved fluidity without causing the problems of the lowering of impact strength and the bleeding of the agent when compounded to a thermoplastic resin. CONSTITUTION:The objective agent is compose of a cyclopolydialkylsiloxane compound (A) of formula [R<1> and R<2> are same or different 3-16C (preferably 3-12C) alkyl; n is 3 or 4] (e.g. cyclopolydioctylsiloxane). A composition having remarkably improved fluidity of a base resin can be produced without causing the problems of the lowering of impact strength of the resin and the bleeding of the agent by compounding 100pts.wt. of a thermoplastic resin (B) (preferably polyolefin) with 0.1-20 pts.wt. (preferably 0.5-10 pts.wt.) of the cyclopolydialkylsiloxane compound A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a fluidity improver that contains a cyclic polydialkylsiloxane compound as a main component and can be suitably used for thermoplastic resins.

[Prior art and problems to be solved by the invention] Polypropylene (hereinafter abbreviated as PP) is widely used as a general-purpose resin, and as shown in JIS-6747, polymerization type and melt flow rate (hereinafter referred to as MFR) are widely used. (abbreviated)) are classified into many types. The above-mentioned VFR is an important item in determining the moldability of the resin, and the larger the MFR, the lower the melt viscosity, and it can be said that the resin is easier to mold.

On the other hand, impact strength, which is a particularly important physical property among the physical properties of PP, increases as the MFR of PP decreases. For this reason,
For applications that require impact strength, resins that have a small MFR and are difficult to mold must be used, resulting in the problem of poor moldability.

Therefore, attempts have been made to improve the fluidity of PP with a small MFR in order to obtain PP with excellent impact strength and moldability. As a method for improving the fluidity of PP, a method of adding polydimethylsiloxane to 100 parts by weight of PP is described in "Bolimada Inest J, November 1988 Issue 106." When 3 parts by weight of siloxane was added, MFR improved 3.5 times compared to PP without polydimethylsiloxane, and no decrease in impact strength was observed, but this is because polydimethylsiloxane is not compatible with PP. Problems such as contamination of equipment due to whitening of PP and bleed-out of polydimethylsiloxane, uneven flow of PP, and changes in surface properties of PP occurred.

[Means to solve the problem]

In order to solve the above problems, the present inventors have synthesized various siloxane compounds and have studied the effects of adding them to PP and thermoplastic resins in general. As a result, it was discovered that when a small amount of a specific cyclic polydialkylsiloxane is added, the fluidity is significantly improved without reducing the impact strength of the resin, without causing problems due to bleed-out of the compound, and providing the present invention. reached.

That is, the present invention is a fluidity improver comprising a cyclic polydialkylsiloxane compound represented by the following general formula (1).

In the above general formula (1), R1 and R2 have 3 carbon atoms.
~16 alkyl groups. If the number of carbon atoms is 2 or less, bleed-out occurs. Also, the number of carbon atoms is 17
In the above cases, even if the cyclic polydialkylsiloxane compound of the present invention is added to the thermoplastic resin, the fluidity is not sufficiently improved, and the thermoplastic resin cannot be sufficiently modified.

The number of carbon atoms in the alkyl group represented by R1 and R2 may be within the above range, but is particularly preferably within the range of 3 to 12. The alkyl groups represented by R1 and R2 can be used regardless of whether they are linear or branched.

In the general formula (1) above, n is 3 or 4. Compounds in which n is other than 3 or 4 are unstable and are therefore not preferred.

The cyclic polydialkylsiloxane compound represented by the above general formula [) can be easily produced by a known method.

By adding a small amount of the compound represented by the general formula (1) to a thermoplastic resin, it can be used without reducing the impact strength of the resin and without causing problems due to bleed-out from the resin. Fluidity can be significantly improved.As the thermoplastic resin, any known thermoplastic resin can be used without any restriction.For example, various resins such as polyolefin, polyvinyl chloride, polystyrene, polyamide, polyester, polyether, and polycarbonate can be used. In particular, the effect of addition to polyolefins is good.The amount of the cyclic polydialkylsiloxane compound of the present invention is 0.1 to 20 parts by weight per 100 parts by weight of the thermoplastic resin.
The amount ranges from 0.5 to 10 parts by weight, more preferably from 0.5 to 10 parts by weight. If the amount is less than 0.1 parts by weight, the effect of improving fluidity will be poor, and if the amount exceeds 20 parts by weight, the physical properties of the thermoplastic resin may be deteriorated.
Undesirable.

〔effect〕

The cyclic polydialkylsiloxane compound represented by the general formula [1) of the present invention does not reduce the impact strength of the thermoplastic resin, does not cause problems due to bleed-out of the compound from the thermoplastic resin, and is suitable for use in thermoplastic resins. Significantly improves fluidity. Specifically, for example, R of the compound represented by the general formula CI) with respect to 100 parts by weight of PP
When 3 parts by weight of a compound in which 1 and R2 are both octyl groups is added, the fluidity of PP is improved three times compared to that of PP without the compound represented by the general formula CI). No decrease in impact strength was observed. Also, PP
Problems such as whitening of the PP and bleed-out of the cyclic polydioctylsiloxane from the PP did not occur. on the other hand,
When adding the same amount of polydimethylsiloxane as above, P
The fluidity of P was improved by 3.5 times compared to the case without addition, and no decrease in the impact strength of PP was observed, but whitening of PP and bleed-out of the polydimethylsiloxane from PP occurred. As will be clear from the comparison of Examples and Comparative Examples described later, this unique effect is an effect that is expressed only when the alkyl group of the compound represented by the general formula CI) has 3 to 16 carbon atoms.

(Examples) In order to explain the present invention more specifically, Examples and Comparative Examples will be described below, but the present invention is not limited to these Examples at all.

In addition, the fluidity of the resin shown in the examples and comparative examples is J
Measured by IS K7210, impact strength is JISK
7110. In addition, additive bleed-out tests were carried out after molding the resin at a temperature of 23 ± 2°C and a relative humidity of 5.
A sample stored for one week at 0 ± 5% is immersed in n-hexane for 10 minutes, and the amount of eluted additive is divided by the amount of additive contained in the sample before the immersion test to calculate the percentage. expressed.

Example 1 Hexaoctylcyclotrisiloxane (hereinafter referred to as 0ctD
abbreviated as z) 3g and PP (RB-41 manufactured by Tokuyama Soda Co., Ltd.)
0) 100g was kneaded at 180°C for 5 minutes using a roll machine. After that, we measured the MFR of this PP and found that it was 0.
It was improved three times compared to PP without ctlh addition.

This PP was molded according to JIS K6758. The impact strength of the molded PP was 0 ctD, which did not change compared to PP without additives. The appearance of PP is 0ctDz-free P.
P, and no whitening of PP was observed. Also, when I did a bleed-out test for OctD, it was 0c.
tD was not detected.

Example 2 Everything was carried out in the same manner as in Example 1 except that PP was changed to the resin shown in Table 1.

The results are shown in Table-1.

Example 3 The same procedure as in Example 1 was performed except that cyclic polydialkylsiloxane shown in Table 2 was used in the amount shown in Table 2 instead of 0ctD3, and the physical properties of PP were measured. The results are shown in Table-2.

Comparative Example 1 The same operations as in Example 1 were performed except that the compounds shown in Table 3 were used instead of 0ctD in Example 1, and the physical properties of PP were measured. The results are shown in Table-3.

Claims (2)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ However, R^1 and R^2 are the same or different alkyl groups having 3 to 16 carbon atoms, respectively, and n is 3 or 4. . A fluidity improver comprising a cyclic polydialkylsiloxane compound represented by: (2) A composition comprising (a) 100 parts by weight of a thermoplastic resin and (b) 0.1 to 20 parts by weight of the cyclic polydialsiloxane compound described in claim (1).