Moulding compositions based on vinylaromatic copolymers for 3D printing

Patent metadata

Field	Value
Publication number	US-10815367-B2
Application number	US-201415104797-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 18, 2013
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

Thermoplastic moulding composition for 3D printing containing a polymer mixture A made of components a and b: a being from 30 to 95% by weight of at least one vinylaromatic copolymer a with average molar mass Mw from 150 000 to 360 000 g/mol, b being from 5 to 70% by weight of at least one impact modifier b, where the viscosity of the moulding composition (measured in accordance with ISO 11443) at shear rates of from 1 to 10 l/sec and at a temperature of 250° C. is not higher than 1×10 5 Pa*s and the Melt Volume Rate (MVR, measured in accordance with ISO 1133 for 220° C. and 10 kg load) is more than 6 ml/10 min.

First claim

The invention claimed is:

1. A thermoplastic molding composition for 3D printing, comprising a polymer mixture A composed of components a and b:
a: 30 to 95 wt % of at least one polymer a having an average molar mass Mw of 150 000 to 360 000 g/mol, selected from:
vinylaromatic copolymers selected from the group consisting of: styrene-acrylonitrile copolymers, α-methylstyrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene-phenylmaleimide copolymers, styrene-methyl methacrylate copolymers, styrene-acrylonitrile-maleic anhydride copolymers, styrene-acrylonitrile-phenylmaleimide copolymers, α-methylstyrene-acrylonitrile-methyl methacrylate copolymers, α-methylstyrene-acrylonitrile-tert-butyl methacrylate copolymers, and styrene-acrylonitrile-tert-butyl methacrylate copolymers, and
b: 5 to 70 wt % of at least one impact modifier b, built up from components b1 and b2:
b1: 20-90 wt % of a graft base made from one or more monomers, consisting of:
b11: 70 to 100 wt % of at least one conjugated diene, and
b12: 0 to 30 wt % of styrene, and,

b2: 10 to 80 wt % of a graft made from one or more monomers, consisting of:
b21: 65 to 95 wt % of at least one vinylaromatic monomer,
b22: 5 to 35 wt % of acrylonitrile and/or methacrylonitrile, and
b23: 0 to 30 wt % of at least one further monoethylenically unsaturated monomer selected from: MMA, MAN, and N-PMI;

where the sum of components a and b totals 100 wt %,
characterized in that the viscosity (measured to ISO 11443) of the molding composition at shear rates of 1 to 10 1/s and at temperatures of 250° C. is not higher than 1×10 5 Pa*s and the melt volume rate (MVR, measured to ISO 1133 at 220° C. and 10 kg load) is more than 6 ml/10 min;
wherein the residual monomer content is not more than 2000 ppm and the solvent content is not more than 1000 ppm; and
the impact modifier b has a trimodal particle size distribution and is a mixture of ABS graft copolymers b′, b″, and b′″ where the graft base b1′ of the ABS graft polymer b′ has an average particle diameter d 50 of 25 to 200 nm, the graft base b1″ of the ABS graft copolymer b″ has an average particle diameter d 50 of 230 to 330 nm, and the graft base b1′″ of the ABS graft copolymer b′″ has an average particle diameter d 50 of 340 to 480 nm.

2. The molding composition as claimed in claim 1 , characterized in that additionally there is
at least one further polymer b, selected from polycarbonates, polyamides, poly(meth)acrylates, polyesters, and styrene-butadiene block copolymers; and/or
customary additives; and/or
auxiliaries c.

3. The molding composition as claimed in claim 1 , characterized in that at least half of the polymers present in the molding composition are amorphous polymers.

4. The molding composition as claimed in claim 1 , comprising:
40 to 100 wt % of polymer mixture a,
0 to 60 wt % of polymer b, and
0 to 40 wt % of minerals as auxiliaries c,
based in each case on the overall molding composition, and where the sum of a, b and c is 100 wt %.

5. The molding composition as claimed in claim 1 , characterized in that the particle size of the impact modifier b is at least 50 nm and at most 10 μm.

6. The molding composition as claimed in claim 1 , characterized in that polymer a is a styrene-acrylonitrile copolymer (SAN) comprising 18 to 35 wt % acrylonitrile and 82 to 65 wt % styrene.

7. The molding composition as claimed in claim 1 , characterized in that the impact modifier b has bimodal, trimodal or multimodal particle size distributions.

8. The molding composition as claimed in claim 1 , characterized in that the impact modifier b is an ABS impact modifier b built up from:
b1: 40 to 90 wt % of a graft base consisting of:
b11: 70 to 100 wt % of butadiene, and
b12: 0 to 30 wt % of styrene, and

b2: 10 to 60 wt % of a graft consisting of:
b21: 65 to 95 wt % of styrene,
b22: 5 to 35 wt % of acrylonitrile, and
b23: 0 to 30 wt % of MMA.

9. The molding composition as claimed in claim 1 , characterized in that in the polymer mixture A, the fraction of the polymer a is 75 to 95 wt % and the fraction of the impact modifier b is 5 to 25 wt %.

10. The molding composition as claimed in claim 1 , characterized in that in the polymer mixture A, the fraction of the polymer a is 65 to 95 wt % and the fraction of the impact modifier b is 5 to 35 wt %.

11. The molding composition as claimed in claim 1 , characterized in that in the polymer mixture A, the fraction of the polymer a is 30 to 60 wt % and the fraction of the impact modifier b is 40 to 70 wt %.

12. The molding composition as claimed in claim 1 , characterized in that the coefficient of linear thermal expansion is less than 100×10 −6 1/K.

13. The molding composition as claimed in claim 1 , characterized in that the transition metal content is not more than 500 ppm.

14. A method of 3D printing comprising the step of extruding the molding composition as claimed in claim 1 to produce an object.

15. A method of 3D printing comprising the step of extruding the molding composition as claimed in claim 11 to produce a filament.

16. A method of 3D printing comprising the step of extruding the molding composition as claimed in claim 1 to produce an object for home application.

17. A method for producing 3-dimensional moldings from the molding composition as claimed in claim 1 by fused deposition modeling, where, in a 3D printer with a heating nozzle freely movable in the fabrication plane, a supplied filament of the molding composition is fluidized, and the fluidized molding composition is extruded, applied layer by layer, and consolidated.

18. The method as claimed in claim 17 , characterized in that filaments of the molding composition melted in a 3D printer having a heating nozzle diameter of 0.3 to 0.8 mm at a nozzle temperature of 200 to 270° C., and the melted molding composition is extruded at an extrusion rate of 60 to 180 mm/s.

19. A method for determining the print quality of a 3-dimensional molding produced as claimed in claim 17 , characterized in that the ratio of the width of the extruded strand to minimum edge length or of the width of the extruded strand to minimum diameter of the 3-dimensional molding is at least 1:20.

Assignees

• Ineos Styrolution Group Gmbh

Inventors

• Niessner Norbert
• Eisentraeger Frank
• Baumann Stephanie
• Lohse Itana
• Schmidt Hans-Werner
• Meiners Josef
• Wieberger Florian

Classifications

• B33Y40/10

  Pre-treatment · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• C08L25/12 Primary

  with unsaturated nitriles · CPC title

• B29C64/386

  Data acquisition or data processing for additive manufacturing · CPC title

• C08L53/00

  Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers · CPC title