US006239221B1
(12) United States Patent Chen
(54)
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(10) Patent N0.: US 6,239,221 B1 (45) Date of Patent: May 29, 2001
LOW GLOSS WEATHERABLE POLYMER
3,489,822
COMPOSITION
4,127,617 4,145,378
Inventor;
Chuan-Ju Chen, Amherst, MA (US)
4,801,646 4,877,826
(73) Assignee: Bayer Antwerpen S.A./N.V., Antwerp (BE) (*)
Notice:
U_S_C_ 154(k)) by 0 days
(21) APPl- N°~1
09/029,326
1/1989 Henton ................................. .. 525/71 Beyer ..... ..
.. 524/377
4,904,730 * 2/1990 Moore et al
525/75
4,912,162 4,946,894 5,112,895 5,397,836 * 5,658,985
Subject to any disclaimer, the term of this patent is extended or adjusted under 35
1/1970 Witt et al. . 11/1978 Arrighetti et al. . 3/1979 Arrighetti et al. . 10/1989
3/1990 8/1990 5/1992 3/1995 8/1997
Kishida et al. .. 525/67 Henton et al. 525/71 Chen et a1- ----------- ~- 524/308 DeNicola, Jr. et al. ............. .. 525/71 Eichenauer et al. ................. .. 525/83
FOREIGN PATENT DOCUMENTS
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PCT Filed:
Sep. 13, 1995
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PCT No.:
PCT/US95/11617
§ 371 Date:
Mar. 3, 1998
§ 102(e) Date: Mar. 3, 1998 (87) PCT Pub No; W097/10301
283611
9/1988 (EP) _
0412370 *
7/1991 (EP) .
* Cited by examiner
Primary Examiner—Jeffrey C. Mullis (74) Attorney, Agent, or Firm—J0seph C. Gil; Aron Preis
PCT Pub. Date: Mar. 20, 1997
(57) (51)
Int. Cl.7 ...................................................... .. C08L 9/02
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US. Cl. ........................ .. 525/193; 525/206; 525/227;
525/233; 525/238; 525/241 (58)
ABSTRACT
Apolymer Composition Comprising a blend of (a) a grafted
ole?n rubber, (b) an ungrafted ole?n rubber, (c) a copoly
Field of Search ................................... .. 525/193, 206,
meric matriX and an Optional (9) a grafted awn/late rubber is
525027, 233, 238, 241
disclosed. The composition Which is characterized in having a desirable balance of impact strength and loW gloss is useful for molding and extrusion of articles for certain outdoor
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References Cited U.S. PATENT DOCUMENTS 3,489,821
1/1970 Witt et al. .
applications. 8 Claims, N0 Drawings
US 6,239,221 B1 1
2
LOW GLOSS WEATHERABLE POLYMER COMPOSITION
in the presence of the rubbery EPDM polymer utiliZing either emulsion, suspension or solution polymeriZation tech niques. Examples of EPDM graft copolymers are taught in US. Pat. Nos. 3,489,821, 3,489,822, 3,642,950 and 4,314,
BACKGROUND OF THE INVENTION
041 all of Which are incorporated herein by reference. Preferred grafted EPDM rubbers have a Weight average particle siZe from 0.1 p to 1.0 p. Most preferred are those
Grafted rubber compositions are Well known in the art.
Poly(acrylonitrile butadiene styrene) or ABS is Widely knoWn and used as a molding and extrusion composition. In
rubbers prepared by grafting the rubber spine in a solution
ABS, polybutadiene is grafted With acrylonitrile and styrene. For outdoor applications Where the polymer composition is exposed to sunlight and Weather, a saturated rubber such as
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polybutyl acrylate (PBA) polyethylene propylene (EP) or
knoWn in the art and described, for example, in US. Pat.
polyethylene propylene diene monomer (EPDM) is used in place of the butadiene used in ABS. Blends of these grafted
Nos. 3,830,878; 4,341,883; 3,944,631; 3691,260 and 4,224, 419, the teachings of Which are incorporated herein by
saturated rubbers are also knoWn.
1. Field of the Invention The present invention is directed to a polymer composi tion Which is a blend of (a) an ole?n rubber such as ethylene
reference. Preferred acrylate rubbers are crosslinked 15
such as ethylene propylene diene monomer rubber (EPDM);
about 10 percent, of a copolymeriZable comonomer. Suitable copolymeriZable comonomers include monovinylidene aro 20
(c) a poly(acrylonitrile styrene) matrix; and (d) optionally a butyl acrylate rubber grafted With styrene and acrylonitrile. suitable as molding and extrusion compounds for certain
matic monomers, e.g. styrene, alpha-methyl styrene, etc., acrylonitrile and alkyl methylacrylates such as methyl meth
acrylate. A preferred acrylate rubber comprises butyl acry late optionally containing various di-and tri-vinyl substi tuted crosslinking and graft enhancing agents present in an
These polymer compositions have a desirable balance of loW
gloss and impact strength Which makes them especially
homopolymers of C1_8 alkyl acrylates, especially butyl acry late or 2-ethylhexyl acrylate, and crosslinked copolymers thereof With up to about 25 Weight percent, preferably up to
propylene diene monomer rubber grafted With styrene and
acrylonitrile (EPDM-g-SAN); (b) an ungrafted ole?n rubber
or suspension process having a particle siZe of from 0.3 p to 0.6 p. Acrylate rubbers for use in the present invention are Well
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amount up to about 5 percent by Weight based on total
rubber Weight. Preferably the acrylate rubber is prepared by an emulsion
outdoor applications. 2. Description of Related Art
process. Emulsion polymeriZed acrylate rubbers may be
Butyl acrylate rubber and EPDM rubbers grafted With
partially agglomerated as is knoWn in the art in order to
styrene and acrylonitrile are Well knoWn in the art. Such
30
provide a greater variety of particle siZe distribution in the
compositions are taught in US. Pat. No. 3,489,822 (Witt et al); US. Pat. No. 4,127,617 (Arrighetti et al); US. Pat. No.
resulting acrylate rubber product thereby controlling gloss
4,145,378 (Arrighetti et al); and US. Pat. No. 4,912,162 (Kishida et al). Blends of a butyl acrylate rubber grafted With
can also be groWn to various siZes by varying the polymer iZation conditions and/or a mixture of previously prepared large and small seed particles may be employed to form the
styrene and acrylonitrile (BA-g-SAN) and an EP or EPDM
and impact properties of the polymer. The rubber particles
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rubber grafted With styrene and acrylonitrile (EP-g-SAN or
grafted rubber. The grafted acrylate rubber’s Weight average
EPDM-g-SAN) are also Well knoWn and are taught in US.
particle diameter is preferably from about 0.05 p to about 0.5
Pat. No. 4,877,826 (Beyer); US. Pat. No. 4,946,894 (Henton
p, most preferably from 0.1 p to 0.25 p. Particle diameters are measured in the latex form of the rubber before grafting
et al) and US. Pat. No. 5,112,895 (C. J. Chen and F. M.
Peng).
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using techniques of transmission Electron Microscopy or hydrodynamic chromatography as disclosed in US. Pat. No.
SUMMARY OF THE INVENTION
4,419,496. Grafting of acrylate rubbers is also Well knoWn
The present invention is directed to molding and extrusion
in the art and is disclosed, for example, in the above cited
compositions Which have loW sheet gloss (less than 50 preferably less than 40 at a 60° angle) and good IZod impact (greater than 50 J/m). The compositions comprise (a) an
US. Pat. Nos. 3,830,878; 4,341,893; 3,944,631; 3,691,260 and 4,224,419. Preferably the crosslinked acrylate rubber is
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grafted by means of an emulsion process.
ole?n rubber grafted With a vinyl aromatic monomer and an
The amount of grafting in both the EPDM and acrylate
unsaturated nitrile monomer and optionally one or more
rubbers may vary over a Wide range. As de?ned by percent
grafting (attached rigid phase Weight/rubber Weight>