US 5,652,307 AGrant
Three Stage Graft Copolymers and Weathering-Stable, Dull Thermoplastic Molding Materials Containing Said Copolymers and Having Good Low-Temperature Toughness
Issue Date:1997-07-29
•7 Claims
Abstract
Graft copolymers obtained by (A) polymerizing 10 to 89 wt % of a mixture consisting essentially of either (B) polymerizing 10 to 89 wt % of a mixture consisting essentially of and in the presence of the graft copolymer (A) and used to prepare thermoplastic molding materials. (a1) from 70 to 99.89 wt % of a C.sub.1 -C.sub.18 -alkyl ester of acrylic acid, (a2) from 0.1 to 10 wt % of a polyfunctional monomer, (a3) from 0 to 29.89 wt % of an ethylenically unsaturated monomer which differs from (a1) and (a2), is copolymerizable therewith and carries no acid group and (a4) from 0.01 to 10 wt % of a copolymerizable monomer containing at least one acid group or (a5) from 49.99 to 99.99 wt % of at least one diene, (a6) from 0 to 50 wt % of a monomer which is copolymerizable therewith and carries no acid group and (a7) from 0.01 to 10 wt % of a copolymerizable monomer containing at least one acid group in the presence of from 1 to 80 wt % of a cross-linked silicone rubber to form a copolymer A, and (b1) from 50 to 99.99 wt % of a styrene compound of the formula (I) ##STR1## where R.sup.1 and R.sup.2 independently of one another are each hydrogen, C.sub.1 -C.sub.8 -alkyl, etc. (b2) from 0 to 50 wt % of a methacrylonitrile, acrylonitrile, methacrylic acid, acrylic acid, maleic anhydride, etc. monomer (b3) from 0.01 to 20 wt % of a copolymerizable monomer containing at least one basic group
Metadata
Assignee
- BASF Aktiengesellschaft
Inventors
- Norbert Niessner
- Wolfgang Fischer
Application Information
Application Number:US 7308086
Filing Date:1996-10-17
Priority Date:1993-12-09
Art Unit:151
Classifications
IPC:
C08F28312
Field of Search:
525101;104;106;426;431;445;446;455;474;479
Patent Drawings
This patent does not have any drawings.
Description
Examples
The notched impact strength a.sub.k (injection molding temperature/test temperature) (in kj/m.sup.2) was determined at test temperatures of 23.degree. C. and -40.degree. C. according to DIN 53453 using standard small bars injection molded at 220.degree., 250.degree. and 280.degree. C.
The surface quality (dull or glossy) was determined visually by viewing under sunlight at an angle of 45.degree. to the surface of the shaped article.
The stated median particle sizes are the weight average of the particle sizes which were determined by means of an analytical ultracentrifuge according to the method of W. Scholtan and H. Lange, Kolloid-Z. and Z. Polymere 250 (1972), 782-796. The ultracentrifuge measurement gives the integral mass distribution of the particle diameter of a sample. From this it is possible to determine the percentage by weight of particles which have a diameter equal to or smaller than a certain size. The median particle diameter, which is also referred to as the d.sub.50 value of the integral mass distribution, is defined as the particle diameter at which 50% by weight of the particles have a diameter smaller than the diameter corresponding to the d.sub.50 value. Likewise, 50% by weight of the particles then have a diameter larger than the d.sub.50 value.
1. Preparation of the graft copolymers A
1.1 A crosslinked polydimethylsiloxane emulsion (prepared similarly to Example 1 of EP-A 492 376) was used as silicon emulsion A1: solids content (SC): 17.4%; particle diameter 156 nm; viscosity 4.6 mPa.s; pH 7; degree of crosslinking 3%; 0.5% of methacryloyloxypropyl functions.
1.2 Preparation of the 1st shell A2
1.2.1 Initially taken mixture Emulsion A1 (cf. Table 1) and water were heated to 60.degree. C. and potassium persulfate (KPS) was then added.
1.2.2 Feed A mixture of n-butyl acrylate (BA) and the acrylate of tricyclodecenyl alcohol (DCPA) was then added dropwise in the course of 1.5 hours. At the same time, a mixture of water and the sodium salts of a mixture of C.sub.13 - and C.sub.14 -alkanesulfonic acids (soap) was added dropwise. The emulsion A2 obtained was not isolated.
1.3 Preparation of the 2nd shell
5.1 g of potassium persulfate were added to the emulsion A2 and the monomers from Table 1 (styrene, acrylonitrile and, if required, dimethylaminoethyl acrylate (DMAEA)) were added dropwise in the course of 3 hours. Stirring was continued for 2 hours. Theoretical solids content: 40.0%.
Experiment 1 and Comparative Experiment 2 had the same amount of comonomers but the latter had no silicone core.
Component B
A solution polymer of styrene and acrylonitrile in the weight ratio of 65:35, having a viscosity number of 80 ml/g (measured at 23.degree. C. in a 0.5% strength by weight dimethylformamide solution) was used.
Preparation of the mixtures
The rubbers (Experiment V1, V2 and 1) were mixed with the component B in a weight ratio of 1:1, the mixture was extruded at 250.degree. C. in a ZSK 30 twin-screw extruder from Werner & Pfleiderer and the extrudate was granulated. Moldings for mechanical testing were produced from the granules at 220.degree., 250.degree. and 280.degree. C. (Table 1).
Claims
We claim:
1. A thermoplastic molding material comprising (I) from 1 to 95% by weight of a graft copolymer prepared by (A) polymerizing from 10 to 89% by weight based on the total amount of said graft copolymer of a mixture consisting essentially of either (a1) from 70 to 99.89% by weight of a C.sub.1 -C.sub.18 -alkyl ester of acrylic acid, where the alkyl radical is optionally monosubstituted by phenyl or phenoxy, (a2) from 0.1 to 10% by weight of a polyfunctional monomer which is a vinylically unsaturated compound having at least two double bonds, (a3) from 0 to 29.89% by weight of an ethylenically unsaturated monomer which differs from (a1) and (a2), is copolymerizable therewith and carries no acid group or basic group and (a4) from 0.01 to 10% by weight of a copolymerizable monomer containing at least one acid group or at least one basic group or (a5) from 49.99 to 99.99% by weight of at least one diene, (a6) from 0 to 50% by weight of a monomer which is copolymerizable therewith and carries no acid group and (a7) from 0.01 to 10% by weight of a copolymerizable monomer containing at least one acid group or at least one basic group in the presence of from 1 to 80% by weight of a crosslinked silicone rubber based on the total amount of said graft copolymer to form the copolymer A and (B) polymerizing from 20 to 89% by weight based on the total amount of said graft copolymer of a mixture consisting essentially of (b1) from 50 to 99.99% by weight of a C.sub.1 -C.sub.8 alkyl ester of methacrylic acid or acrylic acid and/or a styrene compound of the formula (I) ##STR2## where R.sup.1 and R.sup.2 independently of one another are each hydrogen, C.sub.1 -C.sub.8 -alkyl or C.sub.1 -C.sub.4 -alkyl-monosubstituted, C.sub.1 -C.sub.4 -alkyl-disubstituted or C.sub.1 -C.sub.4 -alkyl-trisubstituted phenyl, (b2) from 0 to 50% by weight of a monomer selected from the group consisting of methacrylonitrile, acrylonitrile, methacrylic acid, acrylic acid, maleic anhydride, maleimide N-substituted by C.sub.1 -C.sub.4 -alkyl, vinyl esters of aliphatic C.sub.2 -C.sub.8 -carboxylic acids, acrylamide and vinyl methyl ether and p1 (b3) from 0.01 to 20% by weight of a copolymerizable monomer containing at least one basic group or at least one acid group in the presence of the copolymer (A) with the proviso that when the at least one group of (a4) or (a7) is an acid group, the at least one group of (b4) is a basic group and when the at least one group of (a4) or (a7) is basic group the at least one group of (b4) is an acid group, said thermoplastic molding material further comprising (II) at least one thermoplastic polymer having a glass transition temperature of more than 25.degree. C. as a matrix.
2. The thermoplastic molding material as defined in claim 1 further comprising additives and assistants.
3. The thermoplastic molding material as defined claim 1 wherein the at least one group of (a4) or (a7) of the graft copolymer is a basic group, and the at least one group of (b3) of the graft copolymer is an acid group.
4. A thermoplastic molding material as defined in claim 1 wherein the graft copolymer has a median particle size of from 0.05 to 10 micrometers.
5. The thermoplastic molding material of claim 4 wherein in the graft copolymer a C.sub.2 -C.sub.4 -alkyl ester of methacrylic or acrylic acid, where the C.sub.2 -C.sub.6 -alkyl moiety is monosubstituted or disubstituted by amino is used as component (a4) and an alpha, beta-unsaturated C.sub.1 -C.sub.6 -carboxylic acid us used as component (b3).
6. The thermoplastic molding material of claim 1 wherein the at least one group of (a4) or (a7) is an acid group, and the at least one group of (b3) is a basic group.
7. A molding prepared from the thermoplastic molding material as defined in claim 1.
Patent Citations (1)
| Patent | Date | Inventor | Cited By |
|---|---|---|---|
| US5585436 | 1996-12-01 | Niessner et al. |