Use of molding materials based on vinyl aromatic/diene block copolymers for 3-D-printing

1. A method of 3D printing, comprising a step of fluidizing and extruding a molding composition to form an object,

wherein the molding composition comprises components A, B1, B2, and C:

A: 5 to 100 wt % of at least one vinylaromatic-diene block copolymer A prepared by anionic polymerization containing a random construction of:

40 to 95 wt % of at least one vinylaromatic monomer (S), and

5 to 60 wt % of at least one diene monomer (B),

where (S) and (B) add up to 100 wt %,

wherein block copolymer A comprises at least one block (B/S) which forms a soft phase,

B1: 0 to 95 wt % of at least one polymer B1 selected from the group consisting of: standard polystyrene and high-impact polystyrene,

B2: 0 to 60 wt % of one or more further polymers B2 selected from: polycarbonates, polyamides, poly(meth)acrylates, polyesters, semicrystalline polyolefins, and polyvinyl chloride,

C: 0 to 50 wt % of customary additives and auxiliaries,

wherein 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 m1/10 min,

wherein a 3D printer is used for the 3D printing.

2. A method of claim 1 , wherein the at least one vinylaromatic-diene block copolymer A is a styrene-butadiene block copolymer, wherein the at least one vinylaromatic monomer (S) is styrene and the at least one diene monomer (B) is butadiene.

3. A method of claim 1 , wherein the molding composition comprises:

20 to 99.9 wt % of the at least one vinylaromatic-diene block copolymer A,

0 to 79.9 wt % of the at least one polymer B1,

0 to 30 wt % of the one or more further polymers B2, and

0.1 to 40 wt % of the customary additives and auxiliaries C.

4. A method of claim 1 , wherein the molding composition comprises:

30 to 79.8 wt % of the at least one vinylaromatic-diene block copolymer A,

20 to 69.8 wt % of the at least one polymer B1,

0.2 to 30 wt % of the customary additives and auxiliaries C.

5. A method of claim 1 , wherein the molding composition has a residual monomer content of not more than 1000 ppm.

6. A method of claim 1 , wherein a coefficient of linear thermal expansion CLTE of the molding composition is less than 100×10 −6 1/K.

7. A method of claim 1 , wherein the molding composition comprises:

20 to 99.8 wt % of the at least one vinylaromatic-diene block copolymer A,

0.1 to 79.8 wt % of the at least one polymer B1,

0 to 30 wt % of the one or more further polymers B2, and

0.1 to 40 wt % of the customary additives and auxiliaries C.

8. A method of claim 1 , wherein the molding composition comprises:

40 to 60 wt % of the at least one vinylaromatic-diene block copolymer A,

40 to 60 wt % of the at least one polymer B1,

0.2 to 10 wt % of the customary additives and auxiliaries C.

9. A method of claim 2 , wherein the styrene in the styrene-butadiene block copolymer is present in an amount of 40-85 wt % and the butadiene in the styrene-butadiene block copolymer is present in an amount of 15-60 wt %.

10. The method of claim 1 , wherein the at least one vinylaromatic-diene copolymer A comprises:

(1) at least two hard blocks of the at least one vinylaromatic monomer (S) and

(2) at least one soft block of the at least one diene monomer (B) and optionally the at least one vinylaromatic monomer (S),

wherein the at least one soft block (2) is in-between the at least two hard blocks (1), and the amount of the hard blocks (1) being more than 40 wt % but less than 95 wt %, based on the at least one vinylaromatic-diene block copolymer A.

11. The method of claim 10 , wherein the at least one vinylaromatic-diene copolymer A comprises:

(1) the at least two hard blocks of the at least one vinylaromatic monomer (S) and

(2) the at least one soft block of the at least one diene monomer (B) and the at least one vinylaromatic monomer (S).

12. A method of claim 1 , wherein the block copolymer A is a block copolymer A1 with at least two random (B/S) blocks.

13. A method of claim 1 , wherein the block copolymer A is a block copolymer A2 with a random (B/S) block represented by one of formulae 1 to 11:

(S-B/S) n ;  (1)

(S-B/S) n -S;  (2)

B/S-(S-B/S) n ;  (3)

X-[(S-B/S)n] m+1 ;  (4)

X-[(B/S-S)n]m+1;  (5)

X-[(S-B/S)n-S]m+1;  (6)

X-[(B/S-S)n-B/S]m+1;  (7)

Y-[(S-B/S)n]m+1;  (8)

Y-[(B/S-S)n]m+1;  (9)

Y-[(S-B/S)n-S]m+1;  (10)

Y-[(B/S-S)n-B/S]m+1;  (11)

where

X is a residue of an n-functional initiator,

Y is a residue of an m-functional coupling agent, and

m, n are natural numbers from 1 to 10.