Pmma moulding compounds with improved impact resistance

• US 20040030046A1
• Filed: 08/18/2003
• Published: 02/12/2004
• Est. Priority Date: 09/04/2000
• Status: Active Grant

• Current Assignee: Evonik Rã¶Hm GmbH (Rag-Stiftung)
• Original Assignee: Roehm GmbH & Co. KG
• Inventors: Schultes, Klaus, Arndt, Thomas, Suefke, Thomas, Mueller, Reiner, Laatsch, Joachim, Michler, Goerg
• Granted Patent: US 7,179,852 B2
• Time in Patent Office: Days
• US Class Current: 525/71
• CPC Class Codes: C08F 265/04 on to polymers of esters
• CPC Class Codes: C08F 265/06 Polymerisation of acrylate or methacrylate esters on to polymers thereof
• CPC Class Codes: C08F 285/00 Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 51/003 grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds C08L51/04, C08L51/06 take precedence
• CPC Class Codes: Y10S 525/902 Core-shell

Abstract

The invention relates to a novel impact-resistance modifier, constructed from a core-shell 1 and a shell 2, whereby the core is plastically deformable. The invention is characterised by excellent mechanical properties obtained by a low content of impact-resistance modifier.

Claims

1. Impact modifier, comprising a multistage emulsion polymer, built up from

i) a core (C), built up from the following monomeric components:

a) from 53 to 92.9% by weight of C1-C8-alkyl methacrylate

b) from 7 to 35% by weight of a C1-C8-alkyl acrylate

c) from 0.1 to 2% by weight of a crosslinker or of a crosslinker mixture and

d) from 0 to 8% by weight of styrene derivatives,

ii) a first shell, (S1), built up from the following monomeric components;

a) from 75 to 99.9% by weight of a C1-C8-alkyl acrylate

b) from 0 to 25% by weight of styrene derivatives and

c) from 0.1 to 2% by weight of a crosslinker or of a crosslinker mixture,

iii) a second shell (S2), built up from the following monomeric components;

a) from 80 to 100% by weight of a C1-C8-alkyl methacrylate and

b) from 0 to 20% by weight of a C1-C8-alkyl acrylate

 

from 0 to 5% by weight of a regulator or of a regulator mixture

2. Impact modifier according to claim 1,

characterized in that

at least from 1 to 5% by weight of styrene derivatives are used in the core (C).

3. Impact modifier according to claim 1,

characterized in that

as C1-C8-alkyl acrylate in the core (C), use is made of at least from 5 to 30% by weight of ethyl acrylate.

4. Impact modifier according to claim 1 or 3,

characterized in that

as C1-C8-alkyl acrylate in the core (C), use is made of at least from 5 to 30% by weight of butyl acrylate.

5. Impact modifier according to claim 1,

characterized in that

in the polymerization of S2, use is made of from 0.1 to 1% by weight of a regulator or of a regulator combination, based on the entirety of monomers and regulator in S2.

6. Moulding composition composed of from 3 to 80% by weight of the impact modifier according to one or more preceding claims and from 97 to 20% by weight of a thermoplastic moulding composition based on methyl methacrylate.

7. Moulding composition according to claim 6, characterized by a D65/10°

transmittance greater than 70% and less than 92%.

8. Moulding composition according to claim 6, characterized by a D65/10°

transmittance greater than 80% and less than 92%.

9. Moulding composition according to claim 6, characterized by a D65/10°

transmittance greater than 87% and less than 92%.

10. Use of the moulding composition according to one or more of claims 6 to 9 for producing mouldings.

11. Impact modifier according to claim 1, characterized in that the glass transition temperature of the polymer made from the monomers in core C excluding the crosslinker or the crosslinker mixture is from 30 to 105°

C., as calculated by the Fox equation.

12. Impact modifier according to claim 1, characterized in that the ratios by weight of the core (C), the first shell (S1) and the second shell (2) are

from 15 to 35% by weight of core

from 30 to 55% by weight of shell 1

from 10 to 40% by weight of shell 2.