Method for producing thermoplastic molding compounds with a high glass fiber content

Abstract

The present invention relates to a process for the production of thermoplastic molding compositions, in particular styrene copolymer compositions, to a process for production of these, and also to use thereof. The thermoplastic molding compositions produced by a process of the invention offer improved temperature-resistance and mechanical properties, which have better flow properties than known molding compositions.

Claims

1. A thermoplastic molding composition consisting of: A) from 40 to 50% by weight of a styrene-acrylonitrile copolymer with from 65 to 76% by weight styrene content and with from 35 to 24% by weight acrylonitrile content as component A, B) from 0 to 15% by weight of a graft polymer as component B comprising: B1: a graft base composed of an alkyl acrylate, of an allyl (meth)acrylate, of a copolymerizable monomer, and/or of a diene monomer, B2: at least one graft shell composed of at least one vinylaromatic monomer and/or copolymerizable monomer, C) from 0.1 to 10% by weight of a compatibilizer as component C, where component C is a styrene-acrylonitrile-maleic anhydride terpolymer, where the proportion of acrylonitrile in the terpolymer, based on the entire terpolymer, is from 20 to 25% by weight, D) from 40 to 55% by weight of glass fibers as component D, E) from 0 to 10% by weight of other components, where the entirety of components A, B, C, D, and E gives 100% by weight.

2. The thermoplastic molding composition as claimed in claim 1, consisting of: A) from 40 to 50% by weight of a styrene-acrylonitrile copolymer as component A, B) from 0 to 15% by weight of a graft polymer as component B comprising: B1: a graft base composed of an alkyl acrylate, of an allyl (meth)acrylate, of a copolymerizable monomer, and/or of a diene monomer, B2: at least one graft shell composed of at least one vinylaromatic monomer and/or copolymerizable monomer, C) from 0.5 to 8% by weight of a compatibilizer as component C, D) from 40 to 50% by weight of glass fibers as component D, E) from 0.1 to 4% by weight of stabilizer(s) as component E, where the entirety of components A, B, C, D, and E gives 100% by weight.

3. The thermoplastic molding composition as claimed in claim 1, consisting of: A) from 40 to 50% by weight of a styrene-acrylonitrile copolymer as component A, B) from 0 to 15% by weight of a graft polymer as component B comprising: B1: a graft base composed of an alkyl acrylate, and/or butadiene, B2: at least one graft shell composed of styrene and/or acrylonitrile, C) from 0.5 to 8% by weight of a compatibilizer as component C, D) from 40 to 50% by weight of glass fibers as component D, E) from 0.1 to 4% by weight of stabilizer(s) as component E, where the entirety of components A, B, C, D, and E gives 100% by weight.

4. The thermoplastic molding composition as claimed in claim 1, consisting of: from 40 to 50% by weight of a styrene-acrylonitrile copolymer as component A, C) from 0.5 to 8% by weight of a compatibilizer as component C, D) from 40 to 50% by weight of glass fibers as component D, E) from 0.1 to 4% by weight of stabilizer(s) as component E, where the entirety of components A, C, D, and E gives 100% by weight.

5. The thermoplastic molding composition as claimed in claim 1, where the length of the glass fibers (component D) is ≦50 mm.

6. The thermoplastic molding composition as claimed in claim 1, where component C is composed of one or more copolymers, and where component C comprises at least one styrene-acrylonitrile-maleic anhydride copolymer which comprises from 0.5 to 5% by weight of maleic-anhydride-derived units.

7. The thermoplastic molding composition as claimed in claim 1, comprising, as component E, from 0.05 to 5% by weight of at least two stabilizers.

8. The thermoplastic molding composition as claimed in claim 1, comprising, as component E, a lubricant and a medicinal white oil.

9. A process for the production of a thermoplastic molding composition, wherein in the thermoplastic molding composition consists of: A) from 40 to 50% by weight of a styrene-acrylonitrile copolymer with from 65 to 76% by weight styrene content and with from 35 to 24% by weight acrylonitrile content as component A, B) from 0 to 15% by weight of a graft polymer as component B comprising: B1: a graft base composed of an alkyl acrylate, of an allyl (meth)acrylate, of a copolymerizable monomer, and/or of a diene monomer, B2: at least one graft shell composed of at least one vinylaromatic monomer and/or copolymerizable monomer, C) from 0.1 to 10% by weight of a compatibilizer as component C, where component C is a styrene-acrylonitrile-maleic anhydride terpolymer, where the proportion of acrylonitrile in the terpolymer, based on the entire terpolymer, is from 20 to 25% by weight, D) from 40 to 55% by weight of glass fibers as component D, E) from 0 to 10% by weight of other components, where the entirety of components A, B, C, D, and E gives precisely 100% by weight; the step of mixing the components in a melt.

Description

EXAMPLE 1

(1) The SAN-copolymer molding compositions were compounded in a compounding extruder with various concentrations of glass fiber.

(2) Machine: ZSK40 with GF-metering unit

(3) Melt temperature: 250° C.

(4) Throughput: from 20 to 50 kg/h

(5) Component A (SAN polymer): S/AN ratio 67/33, intrinsic viscosity: 80 dl/g (measured on a 0.5% solution in DMF at 23° C.)

(6) Component C (anhydride-containing copolymer): S/AN/MA copolymer with 3% by weight of MA, 22% by weight of AN, and 75% by weight of S, intrinsic viscosity: 80 dl/g (measured on a 0.5% solution in DMF at 23° C.)

(7) Component D (glass fibers):

(8) By way of example CRATEX 183F-11P glass fibers

(9) (length of glass fibers 250 μm)

(10) TABLE-US-00001 Experiment Comparative Comparative Comparative Comparative Component 1 experiment 1 experiment 2 experiment 3 experiment 4 A 46 60 50 36 26 B 0 0 0 0 0 C 4 0 0 4 4 D 50 40 50 60 70 Granulated Good Good Continuous Continuous Continuous material, compounding compounding compounding visual not possible, difficult not possible, evaluation granulated granulated material not material not homogeneous homogeneous Modulus of 16 12 15-18 20 elasticity (GPa)

EXAMPLE 2 Further Improvement of Mechanical Properties

(11) Component A: S/AN ratio 67/33, intrinsic viscosity: 80 dl/g

(12) (by way of example commercially available product: LURAN 3380 Natural color)

(13) Component B (R−1):

(14) Graft rubber composed of:

(15) 62% by weight of a graft base made of 100% by weight of butadiene

(16) 38% by weight of a graft coating made of S/AN (70/30)

(17) Component B (R-2):

(18) Graft rubber composed of:

(19) 60% by weight of a graft base made of 98% by weight of butyl acrylate and 2% by weight of an acrylate of tricyclodecenyl alcohol

(20) 40% by weight of a graft coating made of S/AN (75/25)

(21) Component C: terpolymer made of S/AN/MA 75/22/3 with IV=80 dl/g (by way of example COMP VT 2421)

(22) Component D: glass fiber (e.g. Cratex 183F-11P)

(23) Components E: additives, in particular stabilizers (by way of example Tinuvin 770 or a combination of two stabilizers (with Tinuvin 770)).

EXAMPLE 2

(24) TABLE-US-00002 Component A 46 Component B 0 Component D 50 (CRATEX 183F-11P) Component C 4

EXAMPLE 3

(25) The molding composition was produced by analogy with example 2 but with 15% by weight of rigid PVC (and a correspondingly smaller quantity of SAN, component A).

(26) An additional increase of mechanical strength was observed.

EXAMPLE 4

(27) The molding composition was produced by analogy with example 2 but additionally with 12% by weight of graft rubber component B (R-1) (polybutadiene-based).

(28) TABLE-US-00003 Component A 34 Component B (R-1) 12 Component D 50 (CRATEX 183F-11P) Component C 4

EXAMPLE 5

(29) The molding composition was produced by analogy with example 2 but with 12% of additional component B (R-2)

(30) TABLE-US-00004 Component A 34 Component B (R-2) 12 Component D 50 (CRATEX 183F-11P) Component C 4
Results of Experiments:

(31) TABLE-US-00005 Experiment: 2 3 4 5 Insertion of a Cracks Does not Does not Does not screw thread crack crack crack through a hole of diameter 3 mm