Process for producing ABS graft copolymers

Patent metadata

Field	Value
Publication number	US-11499044-B2
Application number	US-201816607213-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Apr 24, 2017
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

The invention relates to a process for producing graft copolymers based on acrylonitrile-butadiene-styrene copolymers (ABS), wherein the graft copolymers may be dewatered particularly readily after production and precipitation and have a low residual moisture content after centrifugation. The invention further relates to a process for producing thermoplastic molding materials using the thus obtained ABS graft copolymers.

First claim

What is claimed is:

1. A process for the production of a graft copolymer composition comprising:
B: from 90 to 100% by weight of at least one graft copolymer B comprising:
B 1 : from 40 to 85% by weight, based on the graft copolymer B, of at least one graft base B 1 which is obtained via emulsion polymerization of:
B 11 : from 50 to 100% by weight, based on the graft base B 1 , of butadiene,
B 12 : from 0 to 50% by weight, based on the graft base B 1 , of at least one other monomer B 12 selected from the group consisting of styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, isoprene, chloroprene, C 1 -C 4 -alkylstyrene, C 1 -C 8 -alkyl (meth)acrylate, alkylene glycol di(meth)acrylate, and divinylbenzene;
where the entirety of B 11 +B 12 provides precisely 100% by weight; and

B 2 : from 15 to 60% by weight, based on the graft copolymer B, of a graft shell B 2 which is obtained via emulsion polymerization, in the presence of the at least one graft base B 1 , of:
B 21 from 50 to 95% by weight, based on the graft shell B 2 , of a monomer B 21 selected from the group consisting of styrene and mixtures of styrene with at least one other monomer selected from the group consisting of α-methylstyrene, p-methylstyrene, and C 1 -C 8 -alkyl (meth)acrylate;
B 22 from 5 to 50% by weight, based on the graft shell B 2 , of a monomer B 22 selected from the group consisting of acrylonitrile and mixtures of acrylonitrile with at least one other monomer selected from the group consisting of methacrylonitrile, anhydrides of unsaturated carboxylic, acids and imides of unsaturated carboxylic acids;

where the entirety of graft base B 1 and graft shell B 2 provides precisely 100% by weight; and
K 1 : from 0 to 10% by weight of at least one other component K 1 ,

comprising the steps of:
a) production of the graft copolymer B comprising emulsion polymerization of the graft shell B 2 in the presence of the at least one graft base 131, where the graft copolymer B is obtained in the form of a latex L;
b) precipitation of the latex L of the at least one graft copolymer B after emulsion polymerization via addition of at least one precipitation solution F comprising at least one salt and/or at least one acid, where a precipitation solution F 1 and a portion of the latex L 1 are mixed in a first container H 1 at a temperature T 1 in the range from 30 to 80° C., and the mixture of latex L 1 and precipitation solution F 1 is passed into at least two further containers H 2 and H 3 with temperatures T 2 and T 3 in the range from 60 to 130° C., where optionally further portions of the latex L 2 and/or L 3 and optionally further precipitation solutions F 2 and/or F 3 are added,
where the volume V 1 of the first container H 1 is less than or equal to 30% of the volume V 2 of the second container H 2 ;
c) mechanical dewatering of the precipitated graft copolymer B from step b), where an extracted serum S and a graft copolymer B are obtained, where the residual moisture content of the graft copolymer B is less than or equal to 25% by weight; and
d) optionally drying of the dewatered graft copolymer B from step c).

2. The process of claim 1 , wherein the process comprises the step of:
d) drying of the dewatered graft copolymer B from step c), where a graft copolymer powder is obtained with residual moisture content less than or equal to 5% by weight.

3. The process of claim 1 , wherein the volume V 1 of the first container H 1 is from 0.1 to 10% of the volume V 2 of the second container H 2 .

4. The process of claim 1 , wherein the first container H 1 is a flow tube.

5. The process of claim 1 , wherein the temperature T 2 in container H 2 is higher than the temperature T 1 in container H 1 by at least 10° C.

6. The process of claim 1 , wherein the temperature T 2 in container H 2 is lower than the temperature T 3 in container H 3 by at least 10° C.

7. The process of claim 1 , wherein the temperature T 1 in container H 1 is in the range from 40 to 60° C., the temperature T 2 in container H 2 is in the range from 61 to 84° C., and the temperature T 3 in container H 3 is in the range from 85 to 100° C.

8. The process of claim 1 , wherein the precipitation solution F comprises at least one salt selected from the group consisting of magnesium sulfate, calcium chloride, and sodium chloride, and/or at least one inorganic acid.

9. The process of claim 1 , wherein the precipitation solution F comprises a portion S R of the serum S extracted in step c).

10. The process of claim 1 , wherein the average residence time t 1 of the mixture of latex L and precipitation solution F in container H 1 is in the range from 1 to 1000 seconds.

11. The process of claim 1 , wherein the average residence time of the mixture of latex L and precipitation solution F in the containers H 2 and H 3 is respectively in the range from 5 to 60 min.

12. The process of claim 1 , wherein the graft copolymer B is a mixture of at least two graft copolymers B-I and B-II, where
graft copolymer B-I is obtained via emulsion polymerization of a mixture of the monomers B 21 and B 22 in the presence of a graft base B 1 -A, the average particle diameter D 50 of which is in the range from 230 to 330 nm, and of a graft base B 1 -B, the average particle diameter D50 of which is in the range from 340 to 480 nm;
and graft copolymer B-II is obtained via emulsion polymerization of a mixture of the monomers B 21 and B 22 in the presence of a graft base B 1 -C, the average particle diameter D50 of which is in the range from 10 to 220 nm;
where the mixture of the graft copolymers B-I and B-II is used in step b) as latex L and is precipitated via the addition of the at least one precipitation solution F.

Assignees

• Ineos Styrolution Group Gmbh

Inventors

• Michels Gisbert
• Jansen Ulrich
• Kaminsky Stefan
• Wittenberg Nils
• Rueter Fabian

Classifications

• C08L51/04 Primary

  grafted on to rubbers · CPC title

• C08C1/12

  by evaporation · CPC title

• C08F212/08

  Styrene · CPC title

• C08L2207/53

  Core-shell polymer · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title