DD264011A1 - THERMOPLASTIC MOLDING MATERIALS WITH IMPROVED TENSILE AND FLOWING CAPACITY - Google Patents

Abstract

Thermoplastic molding composition consisting of a graft polymer of A) 5 to 30% by weight of an elastomeric phase having an average number average particle size of 10 to 200 nm and B) 95 to 70% by weight of a continuous hard phase comprising 20 to 35% by weight of an unsupported polymer Nitrile and 80 to 65% by weight of one or more vinylaromatic hydrocarbons. The object of the invention is a thermoplastic molding composition having improved toughness and flowability in an economical manner. This is achieved in that the said graft polymer contains a graft product of 10 to 90% by weight of one or more vinyl esters per 90 to 10% by weight of an atactic polypropylene having a defined molecular weight and defined degree of grafting.

Description

Field of application of the invention

The invention relates to a thermoplastic molding composition with improved toughness and flowability based on a graft polymer which contains graft polymers of an elast phase and a hard phase based on an unsaturated nitrile.

Chnrakteristik the known technical solutions

For thermoplastic molding compositions with improved toughness and flowability on the basis of graft polymers of an elastomeric phase and a continuous hard phase, consisting of an unsaturated nitrile and one or more vinyl aromatic hydrocarbons, various organic substances are known as admixtures as a mixture component. For this purpose used components are z. As perfluoroalkanoic acids and / or their derivatives (DE 2837735), polymethylphenyl or polydimethylsiloxane (DE 2827594) or silico-methane derivative (DE 2837597). Disadvantage of these components is that they are often prepared by complex syntheses and handled as special products. A successful production of corresponding molding materials in economic procedure is thus not possible.

Furthermore, thermoplastic molding compositions are known in which amorphous, linear polypropylene is used as additional component (US Pat. No. 3,375,302). This component is readily available as a by-product in the production of polypropylene and leads to an improvement in the flowability of the molding compositions. However, an increase in impact and notched impact strength is not achievable.

Object of the invention

The aim of the invention is to improve the toughness and flowability of molding compositions while increasing the profitability of Fertigungspro / esses.

Explanation of the essence of the invention

The invention is based on the object, a thermoplastic molding composition having improved toughness and flowability, consisting of a graft polymer

A) 5 to 30% by weight of an elast phase having an average number average particle size of 10 to 200 nm and

B) 95 to 70 Ma .-% of a continuous hard phase of 20 to 35Ma .-% of an unsaturated nitrile and 80 to 65Ma .-% of one or more vinyl aromatic hydrocarbons

to develop.

According to the invention, the object is achieved by a molding composition which consists of a graft polymer which consists of 5 to 30% of an elastomeric phase and 95 to 70% of a hard phase, the 0.5 to 10Ma .-% of a graft product consisting of

a) 10 to 90% by mass of one or more vinyl esters and

b) 90 to 10% by mass of an atactic polypropylene having a molecular weight of 10,000 to 80,000, with a grafting rate of the vinyl ester onto the atactic polypropylene of from 0.01 to 0.9

are added. The vinyl ester used is vinyl acetate.

The inventive method is particularly characterized by the fact that an improvement in the toughness of the molding compositions on the basis of said graft polymers with increased flowability could be achieved in an economical procedure.

embodiments

In the following examples, as graft products, those of vinyl acetate were used for atactic polypropylene. These products had been prepared by known methods by bulk polymerization in the presence of free-radical initiators. The composition of the graft products used in the individual examples and their degree of grafting as the quotient of the mass of the grafted monomer and the mass of the graft base are given in Table 1. '

Examples 1 to A

For these examples, a graft polymer of 18.5% by weight was used as the basis: pure emulsion polybutadiene rubber having an average number average particle size of 54 μm and 81.5% by mass of a continuous hard phase consisting of 25% by weight of acrylonitrile and 75% by weight of styrene. 100 parts by mass, containing this graft polymer and the vinyl acetate-polypropylene graft product in the composition shown in Table 2 were mixed with 0.15 parts by mass of 4,4'-thio-bis (6-tert-butyl-m-cresol) on a Kneader at 200 ⁰ C homogeneously mixed together, granulated and determined by the resulting molding composition, the melt index and the dry loss according to TGL 25496.

From the results also shown in Table 2 it can be seen that compared to the comparative example (Example 4) with the same Gohalt of volatile constituents in the molding composition, a significant increase in the melt index by adding the

Vinyl acetate-polypropylene graft product is achieved.

Examples 5 to 7

In these examples, a graft polymer of an emulsion polybutadiene, styrene and acrylonitrile analogous to Examples 1 to 4 was used. It was mixed according to the amounts shown in Table 3 with the vinyl acetate-polypropylene graft products P3 to P5, 100 parts by mass of this mixture with 0.15 parts by mass of 4,4'-thio-bis- {6-tert-butyl-mcrresol) Homogenized in a kneader at 200 ⁰ C, granulated and determined according to TGL 25496 listed in Table 4 mechanical and thermal properties of the molding composition. The results contained in the table show clearly dio increased by the addition of the vinyl acetate-polypropylene graft product to the graft polymer increase the impact resistance and impact strength.

Examples 8,9

100 parts by weight of a mixture of another batch of the graft polymer used in Examples 1 to 4 with the vinyl acetate-polypropylene graft product P4 according to Table 4 were mixed with 0.15 parts by mass of 4,4'-thio-bis (6-tert. butyl-m-cresol) was homogenized at 200 ° C via a kneader and the properties of the resulting molding composition according to TGL 25496 compared to the pure graft polymer of emulsion polybutadiene, styrene and acrylonitrile under the same conditions obtained molding compound. From Table 4 is clearly the improved impact and impact strength of the

Fo has a better readability of flowability.

Example 10 (comparative example)

In this example, the procedure was analogous to Examples 8 and 9, however, the graft product P4 was substituted by the same amount of ungrafted, pure, atactic polypropylene (PP). As shown by the results in Table 4, although a significant improvement in the flow behavior of the molding compositions is possible by means of pure atactic polypropylene, the impact and impact strength as well as the other mechanical and thermal properties become significant

worse.

Table 1 Composition of vinyl acetate-polypropylene graft products

plug Content of vinyl acetate grafting product (Wt .-%) P1 45.7 0.12 P2 43.2 0.07 P3 44.6 0.03 P4 44.6 0.13 P5 39.7 0.14

TABLE 2 Composition and Properties of the Molding Compositions of Examples 1 to 4 Example Graft Product Graft Polymer

Content of pot product melt index dry loss

iMa .-%) (g / 10 min) (wt .-%)

1 P1 ABS1 1.0 2 P1 ABS1 5.0 3 P2 ABS1 2.5 4 ABS1

44.5 56.5 45.9 40.3

0.24 0.25 0.24 0.24

Table 3 Composition and properties of the molding compositions of Examples 5 to 7

Example grafting-grafting-content of impact bending notch bending ball-bearing hardness Vicat-Ex-

merisat Ptiu ^ iprodukt strength (N / mm ² ) chungstempe-

(Ma .-%) (kJ / m ² ) (kJ / m ² ) door ( ⁰ C)

5 P3 ABS 2 2.0 73.9 / 60 * 14.4 91.0 96 6 P4 ABS 2 0.61 PS 1.01 90.2 / 80 * 15.2 92.9 97 7 - ABS 2 - 75.7 / 35 * 12.8 91.3 95

Gehaltan Shock notch Bullet tension spring Vicat - 3 - 264 011 *% not broken chopsticks Pfropfpro bending impact- print stigk. expanded domestic product strength strength bending hardness (N / mm ² ) ceutical (Wt .-%) ness festigk. {N / mm ² ) temper. enamel Dry (kJ / m ² ) (kJ / m ² ) ( ⁰ C) index loss 5.0 83.3 / 85 » 16.9 89.7 38.4 99 (g / 10 mini (Wt .-%) - 63.8 / 76 » 16.4 92.9 38.9 99 5.0 52.8 / 20 » 10.7 75.1 33.1 96 44.3 0.28 41.5 0.29 69.4 0.29 Table 4 Composition and properties of the molding compositions of examples 8 to 10 Example grafted polypropylene duck merisat sat 8 P4 ABS3 9 - ABS3 10 PP ABS 3 *% not broken chopsticks

Claims (2)

1. Thermoplastic molding composition with improved toughness and flowability, consisting of a graft polymer A) 5 to 30 wt .-% of an elastomeric phase having an average number average particle size of 10 to 200 nm and B) from 95 to 70% by weight of a continuously prepared hard phase comprising from 20 to 35% by weight of an unsaturated nitrile and from 80 to 65% by weight of one or more vinylaromatic hydrocarbons, characterized in that it contains 0.5 to 10% by mass of a graft product consisting of a) 10 to 90% by weight of one or more vinyl esters and b) 90 to 10Ma .-% of an atactic polypropylene having a molecular weight of 10,000 to 80,000 with a Vpfgrad the vinyl ester on the atactic polypropylene from 0.01 to 0.9. 2. Molding composition according to claim 1, characterized in that vinyl acetate is used as the vinyl ester.