Thermoplastic moulding materials based on acrylonitrile, styrene and butadiene

Patent metadata

Field	Value
Publication number	US-9708483-B2
Application number	US-201414784655-A
Country	US
Kind code	B2
Filing date	Apr 16, 2014
Priority date	Apr 18, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

The invention relates to thermoplastic moulding materials based on acrylonitrile-butadiene-styrene, comprising a SAN-polymer matrix and a graft copolymer, structured from an agglomerated butadiene rubber-graft base and a SAN-graft envelope. The agglomerated graft base has a bimodal particle size distribution of a fraction x) of non-agglomerated particles having a d50-value in the range from 80 to 120 nm and a fraction y) of agglomerated particles having a d 50 -value in the range from 350 to 550 nm and a polydispersity U of less than 0.28. The invention further relates to a method for producing the graft copolymer, wherein an acrylate copolymer having a polydispersity U of less than 0.27 and a d50-value of 100 to 150 nm is used for agglomeration. The invention further relates to the use of thermoplastic moulding materials for producing moulded parts.

First claim

The invention claimed is:

1. A process for producing a graft copolymer B constructed from:
B1: 40 to 85 wt %, based on the solids content of the graft copolymer B, of a graft substrate (B1) obtained by (a) polymerizing:
(B11): 0 to 10 wt %, based on the graft substrate B1, of at least one vinylaromatic, and
(B12): 90 to 100 wt %, based on the graft substrate B1, of at least one diene,
where (B11) and (B12) sum to 100 wt %;

and (b) agglomerating the obtained graft substrate B1 by adding
(C): 0.01 to 5 parts by weight, based on 100 parts by weight of the graft substrate B1, in each case based on the solids content, of an agglomerating copolymer (C) of:
(C1): 80 to 99.9 wt % of one or more C 1 to C 12 alkyl methacrylates and
(C2): 0.1 to 20 wt % of one or more comonomers selected from the group consisting of acrylamide and methacrylamide,
where (C1) and (C2) sum to 100 wt %; and

B2: 15 to 60 wt %, based on the solids content of the graft copolymer B, of a graft sheath obtained by reacting the agglomerated graft substrate B1 with a mixture of:
(B21) 70 to 90 wt %, based on the graft sheath B2, of styrene and/or α-methylstyrene, and
(B22) 10 to 30 wt %, based on the graft sheath B2, of acrylonitrile and/or methyl methacrylate,

where the graft substrate B1 and the graft sheath B2 sum to 100 wt % in total; and
where
(i) the agglomerating copolymer (C) has a polydispersity U in the range of from 0.26 to 0.20 and a d 50 value in the range of from 115 to 140 nm; and
(ii) the agglomerated graft substrate B1 has a bimodal particle size distribution of a fraction x) of nonagglomerated particles having a d 50 value in the range of from 80 to 120 nm and a fraction y) of agglomerated particles having a d 50 value in the range of from 350 to 450 nm and a polydispersity U in the range of from 0.27 to 0.20, and the process comprises:
(a) polymerizing the monomers B12 and B11 in aqueous emulsion to afford a particulate graft substrate B1,
(b) agglomerating the particulate graft substrate B1 which is in the form of an emulsion using an agglomerating copolymer (C), wherein the copolymer (C) has a polydispersity U in the range of from 0.26 to 0.20 and a d 50 value in the range of from 115 to 140 nm to afford an agglomerated particulate graft substrate B1, and subsequently
(c) polymerizing the monomers B21 and B22 of the graft sheath in aqueous emulsion in the presence of the agglomerated particulate graft substrate B1.

2. The process according to claim 1 , characterized in that the copolymer (C) is a copolymer of 92 to 98 wt %, based on the total solids in (C), of ethyl acrylate and 2 to 8 wt %, based on the total solids in (C), of methacrylamide having a polydispersity U in the range of from 0.26 to 0.20 and a d 50 value in the range of from 115 to 140 nm.

3. The process according to claim 1 , characterized in that the graft copolymer B is constructed from:
B1: 40 to 85 wt %, based on the solids content of the graft copolymer B, of a graft substrate (B1) obtained by (a) polymerizing:
(B11): 0 to 10 wt %, based on the graft substrate B1, of styrene, and
(B12): 90 to 100 wt %, based on the graft substrate B1, of butadiene,

where (B11) and (B12) sum to 100 wt %;
and (b) agglomerating the obtained graft substrate B1 by adding
(C): 0.01 to 5 parts by weight, based on 100 parts by weight of the graft substrate B1, in each case based on the solids content, of an agglomerating copolymer (C) of:
(C1): 80 to 99.9 wt % of ethyl acrylate and
(C2): 0.1 to 20 wt % of methacrylamide,

where (C1) and (C2) sum to 100 wt %; and
B2: 15 to 60 wt %, based on the solids content of the graft copolymer B, of a graft sheath obtained by reacting the agglomerated graft substrate B1 with a mixture of:
(B21) 70 to 90 wt %, based on the graft sheath B2, of styrene, and
(B22) 10 to 30 wt %, based on the graft sheath B2, of acrylonitrile,

where the graft substrate B1 and the graft sheath B2 sum to 100 wt % in total; and
where
(i) the agglomerating copolymer (C) has a polydispersity U in the range of from 0.26 to 0.20 and a d 50 value in the range of from 115 to 140 nm; and
(ii) the agglomerated graft substrate B1 has a bimodal particle size distribution of a fraction x) of nonagglomerated particles having a d 50 value in the range of from 80 to 120 nm and a fraction y) of agglomerated particles having a d 50 value in the range of from 350 to 450 nm and a polydispersity U in the range of from 0.27 to 0.20.

4. The process according to claim 1 , characterized in that the copolymer (C) has a polydispersity U in the range of from 0.25 to 0.21 and a d 50 value in the range of from 120 to 135 nm.

5. A graft copolymer B obtained by a process according to claim 1 .

6. A thermoplastic molding compound comprising a thermoplastic copolymer A and a graft copolymer B according to claim 5 and optionally further components K, wherein the molding compound comprises:
A: 40 to 80 wt % of at least one thermoplastic copolymer A obtained from:
A1: 20 to 31 wt %, based on the copolymer A, of acrylonitrile, and
A2: 69 to 80 wt %, based on the copolymer A, of styrene or α-methylstyrene or a mixture of styrene and α-methylstyrene,

B: 20 to 60 wt % of the graft copolymer B;
and
K: 0 to 5 wt % of further components K,
where the components A, B, and K sum to 100 wt %.

7. The thermoplastic molding compound according to claim 6 characterized in that the copolymer A is constructed from the monomers styrene and acrylonitrile.

8. The thermoplastic molding compound according to claim 6 , characterized in that said compound additionally comprises at least one further thermoplastic polymer (TP) selected from the group consisting of polycarbonates, polyester carbonates, polyesters, and polyamides.

9. A method of processing a thermoplastic molding compound according to claim 6 for producing molded articles.

10. The process according to claim 1 , characterized in that the copolymer (C) comprises a core constructed from at least one of the monomers cited as component (C1), wherein this core is grafted with a copolymer constructed from the components (C1) and (C2) by an emulsion polymerization comprising the steps of:
(x) emulsion polymerizing at least one monomer (C1) in a first step, and
(y) adding a monomer mixture comprising monomers (C1 +C2) in a further step;
characterized in that the steps (x) and (y) are performed in the presence of at least one emulsifier which is employed in an amount of from 0.05 to 0.50 wt % in step (x),
and in an amount of from 0.45 to 4.50 wt % in step (y), in each case based on the total monomer content of the copolymer (C) in the entire process.

Assignees

• Ineos Styrolution Group Gmbh

Inventors

• Niessner Norbert
• Ahn Sangjun
• Walker Roland
• Pepers Michel
• Banaszak Brian J
• Barth Johannes
• Michels Gisbert
• Patcas Florian
• Hwang Younghwa
• Verstraeten Rudy

Classifications

• C08F2/26

  anionic · CPC title

• C08F285/00

  Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers · CPC title

• C08F212/08

  Styrene · CPC title

• C08L55/02

  ABS [Acrylonitrile-Butadiene-Styrene] polymers · CPC title

• C08F265/04 Primary

  on to polymers of esters · CPC title