U.S. patent application number 11/294126 was filed with the patent office on 2007-06-07 for weatherable resinous composition with low heat storage and method.
Invention is credited to Olga I. Kuvshinnikova, Nela Stafie.
Application Number | 20070129470 11/294126 |
Document ID | / |
Family ID | 37951663 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070129470 |
Kind Code |
A1 |
Kuvshinnikova; Olga I. ; et
al. |
June 7, 2007 |
Weatherable resinous composition with low heat storage and
method
Abstract
Disclosed are compositions comprising: (i) a rubber modified
thermoplastic resin comprising a discontinuous elastomeric phase
dispersed in a rigid thermoplastic phase, wherein the elastomeric
phase comprises a polymer having structural units derived from at
least one (C.sub.1-C.sub.12)alkyl(meth)acrylate monomer; and
wherein the rigid thermoplastic phase comprises structural units
derived from at least one vinyl aromatic monomer and at least one
monoethylenically unsaturated nitrile monomer; and (ii) a colorant
combination comprising at least one inorganic infrared reflecting
pigment and at least one organic colorant, wherein the combination
of the inorganic pigment and organic colorant results in a molded
part with an L* value of less than about 30 with specular component
included, and a heating build-up (HBU) as measured according to
ASTM D4803-89 of less than about 34.degree. C. A method to make
such compositions is also an embodiment of the invention as are
articles made from such compositions.
Inventors: |
Kuvshinnikova; Olga I.;
(Glenmont, NY) ; Stafie; Nela; (Breda,
NL) |
Correspondence
Address: |
Henry H. Gibson - ESR;GE Plastics
One Plastics Avenue
Pittsfield
MA
01201
US
|
Family ID: |
37951663 |
Appl. No.: |
11/294126 |
Filed: |
December 5, 2005 |
Current U.S.
Class: |
524/88 ;
524/407 |
Current CPC
Class: |
C08L 51/003 20130101;
C08K 5/0041 20130101; C08L 51/04 20130101; C08L 55/02 20130101;
C08F 265/04 20130101; C08K 5/0041 20130101; C08L 51/003 20130101;
C08L 51/003 20130101; C08L 2666/02 20130101; C08L 51/04 20130101;
C08L 2666/02 20130101; C08L 55/02 20130101; C08L 2666/02
20130101 |
Class at
Publication: |
524/088 ;
524/407 |
International
Class: |
C08K 5/34 20060101
C08K005/34; C09D 5/08 20060101 C09D005/08 |
Claims
1. A composition comprising: (i) a rubber modified thermoplastic
resin comprising a discontinuous elastomeric phase dispersed in a
rigid thermoplastic phase, wherein at least a portion of the rigid
thermoplastic phase is grafted to the elastomeric phase; and
wherein the elastomeric phase comprises a polymer having structural
units derived from at least one
(C.sub.1-C.sub.12)alkyl(meth)acrylate monomer; and wherein the
rigid thermoplastic phase comprises structural units derived from
at least one vinyl aromatic monomer and at least one
monoethylenically unsaturated nitrile monomer; and (ii) a colorant
combination comprising at least one inorganic infrared reflecting
pigment and at least one organic colorant, wherein the combination
of the inorganic pigment and organic colorant results in a molded
part with an L* value of less than about 30 with specular component
included, and a heating build-up (HBU) as measured according to
ASTM D4803-89 of less than about 34.degree. C.
2. The composition of claim 1, wherein the elastomeric phase
comprises structural units derived from butyl acrylate.
3. The composition of claim 1, wherein the rigid thermoplastic
phase comprises structural units derived from styrene and
acrylonitrile; or styrene, alpha-methyl styrene, and
acrylonitrile.
4. The composition of claim 1, wherein the rigid thermoplastic
phase further comprises structural units derived from one or more
monomers selected from the group consisting of
(C.sub.1-C.sub.12)alkyl- and aryl-(meth)acrylate monomers.
5. The composition of claim 4, wherein the rigid thermoplastic
phase comprises structural units derived from styrene,
acrylonitrile, and methyl methacrylate; or alpha-methyl styrene,
acrylonitrile and methyl methacrylate; or styrene, alpha-methyl
styrene, acrylonitrile and methyl methacrylate.
6. The composition of claim 1, wherein a copolymer comprising
structural units derived from styrene and acrylonitrile;
alpha-methylstyrene and acrylonitrile; alpha-methylstyrene,
styrene, and acrylonitrile; styrene, acrylonitrile, and methyl
methacrylate; alpha-methyl styrene, acrylonitrile, and methyl
methacrylate; or alpha-methylstyrene, styrene, acrylonitrile, and
methyl methacrylate is added to the rubber modified thermoplastic
resin.
7. The composition of claim 1, wherein the inorganic infrared
reflecting pigment comprises: a metal oxide, a mixed metal oxide, a
titanate, an aluminate, a metal carbonate, an iron oxide, a
chromium oxide, an ultramarine, stainless steel powder, mica powder
covered with titanium oxide, a metal sulfide, or a rare-earth
sulfides.
8. The composition of claim 7, wherein the inorganic infrared
reflecting pigment is selected from the group consisting of a
chromium iron oxide, a black spinel, and chrome iron nickel black
spinel.
9. The composition of claim 7, wherein the inorganic infrared
reflecting pigment is present in an amount greater than or equal to
about 0.05 parts per hundred parts resinous components by weight
(phr).
10. The composition of claim 1, wherein the organic colorant is
derived from an anthraquinone, an azo, a phthalic anhydride, a
phthalocyanine, an indigo/thioindigo, an azomethine, an
azomethine-azo, a dioxazine, a quinacridone, an isoindolinone, an
isoindoline, a diketopyrrolopyrrole, a perylene, or a perinone
organic colorant, or mixtures thereof.
11. The composition of claim 1, wherein the organic colorant
comprises at least one colorant selected from the group consisting
of Solvent Green 3, Solvent Red 135, Solvent Violet 13, Pigment
Blue 15:4, Pigment Black 31, Disperse Violet 31/26, and mixtures
thereof.
12. The composition of claim 11, comprising at least two organic
colorants.
13. The composition of claim 1, wherein the total loading of
organic colorant is greater than or equal to about 0.5 phr.
14. The composition of claim 1, further comprising an additive
selected from the group consisting of lubricants, neutralizers,
stabilizers, heat stabilizers, light stabilizers, antioxidants, UV
screeners, UV absorbers, and mixtures thereof.
15. An article made from the composition of claim 1.
16. A composition comprising: (i) a rubber modified thermoplastic
resin comprising a discontinuous elastomeric phase dispersed in a
rigid thermoplastic phase, wherein at least a portion of the rigid
thermoplastic phase is grafted to the elastomeric phase; and
wherein the elastomeric phase comprises a polymer having structural
units derived from butyl acrylate; and wherein the rigid
thermoplastic phase comprises structural units derived from
styrene, acrylonitrile, and optionally methyl methacrylate, and
(ii) a colorant combination comprising an inorganic infrared
reflecting pigment and at least two organic colorants, wherein the
inorganic infrared reflecting pigment is selected from the group
consisting of a chromium iron oxide, a black spinel, and chrome
iron nickel black spinel, and is present in an amount greater than
or equal to about 0.05 phr; and wherein the organic colorant
comprises at least two colorants selected from the group consisting
of Solvent Green 3, Solvent Red 135, Solvent Violet 13, Pigment
Blue 15:4, Pigment Black 31, and Disperse Violet 31/26, and is
present in a total amount greater than or equal to about 0.5 phr;
and wherein the combination of the inorganic pigment and organic
colorant results in a molded part with an L* value of less than
about 30 with specular component included, and a heating build-up
(HBU) as measured according to ASTM D4803-89 of less than about
34.degree. C.
17. The composition of claim 16, wherein a copolymer comprising
structural units derived from styrene and acrylonitrile;
alpha-methylstyrene and acrylonitrile; alpha-methylstyrene,
styrene, and acrylonitrile; styrene, acrylonitrile, and methyl
methacrylate; alpha-methyl styrene, acrylonitrile, and methyl
methacrylate; or alpha-methylstyrene, styrene, acrylonitrile, and
methyl methacrylate is added to the rubber modified thermoplastic
resin.
18. The composition of claim 16, further comprising an additive
selected from the group consisting of lubricants, neutralizers,
stabilizers, heat stabilizers, light stabilizers, antioxidants, UV
screeners, UV absorbers, and mixtures thereof.
19. An article made from the composition of claim 16.
20. A method for preparing an article comprising a rubber modified
thermoplastic resin comprising a discontinuous elastomeric phase
dispersed in a rigid thermoplastic phase, wherein at least a
portion of the rigid thermoplastic phase is grafted to the
elastomeric phase; and wherein the elastomeric phase comprises a
polymer having structural units derived from butyl acrylate; and
wherein the rigid thermoplastic phase comprises structural units
derived from styrene, acrylonitrile, and optionally methyl
methacrylate, wherein the article has an L* value of less than
about 30 with specular component included, and a heating build-up
(HBU) as measured according to ASTM D4803-89 of less than about
34.degree. C.; which method comprises the step of combining the
resin with a colorant combination comprising an inorganic infrared
reflecting pigment and at least two organic colorants, wherein the
inorganic infrared reflecting pigment is selected from the group
consisting of a chromium iron oxide, a black spinel, and chrome
iron nickel black spinel, and is present in an amount greater than
or equal to about 0.05 phr; and wherein the organic colorant
comprises at least two colorants selected from the group consisting
of Solvent Green 3, Solvent Red 135, Solvent Violet 13, Pigment
Blue 15:4, Pigment Black 31, Disperse Violet 31/26, and mixtures
thereof, and is present in a total amount greater than or equal to
about 0.5 phr.
21. The method of claim 20, wherein the rigid thermoplastic phase
comprises structural units derived from methyl methacrylate.
22. The method of claim 20, wherein a copolymer comprising
structural units derived from styrene and acrylonitrile;
alpha-methylstyrene and acrylonitrile; alpha-methylstyrene,
styrene, and acrylonitrile; styrene, acrylonitrile, and methyl
methacrylate; alpha-methyl styrene, acrylonitrile, and methyl
methacrylate; or alpha-methylstyrene, styrene, acrylonitrile, and
methyl methacrylate is added to the rubber modified thermoplastic
resin.
23. The method of claim 20, further comprising an additive selected
from the group consisting of lubricants, neutralizers, stabilizers,
heat stabilizers, light stabilizers, antioxidants, UV screeners, UV
absorbers, and mixtures thereof.
Description
BACKGROUND
[0001] The present invention relates to a rubber modified
thermoplastic resin composition comprising a combination of pigment
and colorant which composition has good color and low heat
accumulating properties, and a method to make such a
composition.
[0002] Dark colors are associated with hot temperatures. In dark
colored plastic articles high temperature often leads to surface
deformation, cracking, and expansion under solar radiation. Use of
inorganic infrared reflecting (IRR) pigments has been described for
example in R. F. Brady and L. V. Wake, "Principles and Formulation
for Organic Coatings with Tailored Infrared Properties" in Progress
in Organic Coatings, 20, 1992. While infrared (IR) reflective
pigments provide benefits against thermal distortion and expansion
problems, the achievable color space is limited to medium dark
colors. For example a jet black color is not achievable in plastic
articles with IR reflective pigments. In particular deep dark color
(dark brown, dark green, dark blue, dark red and black) with L*
value below 40 is not achievable in plastic articles by use of just
IRR pigments. To obtain desired jetness (dark colors with L value
below 30), a organic colorants have also been included in the
compositions as described in U.S. Pat. No. 6,822,041. The
disadvantage is that the organic colorants are known to have poor
resistance to solar radiation and consequently have poor weathering
properties.
[0003] In U.S. Pat. No. 6,366,397 a dark color is achieved in a
plastic article using a multilayer system. A coating arrangement is
described therein which has a higher reflection of sunlight in the
IR range. A disadvantage here is that the arrangement must consist
of two layers to function effectively. A white layer having high
solar reflectance is required as the first or base layer. A darker
colored layer is then applied onto this base layer. The
disadvantage here is not only that two layers must be applied to
achieve a dark surface having low solar absorption, but also that
if damage occurs to the dark outer layer, a white layer then
appears which will disturb the dark appearance. EP 1541636
describes the use of a combination of two inorganic pigments to
obtain a low thermal storage thermoplastic resin with weather
resistance and shock resistance properties.
[0004] It remains of interest, therefore, to develop compositions
for plastic articles which low L* value and also good resistance to
solar radiation.
BRIEF DESCRIPTION
[0005] The present inventors have discovered compositions for
plastic articles which low L* value and also good resistance to
solar radiation. In one embodiment the present invention is a
composition comprising: (i) a rubber modified thermoplastic resin
comprising a discontinuous elastomeric phase dispersed in a rigid
thermoplastic phase, wherein at least a portion of the rigid
thermoplastic phase is grafted to the elastomeric phase; and
wherein the elastomeric phase comprises a polymer having structural
units derived from at least one (C1-C12)alkyl(meth)acrylate
monomer; and wherein the rigid thermoplastic phase comprises
structural units derived from at least one vinyl aromatic monomer
and at least one monoethylenically unsaturated nitrile monomer; and
(ii) a colorant combination comprising at least one inorganic
infrared reflecting pigment and at least one organic colorant,
wherein the combination of the inorganic pigment and organic
colorant results in a molded part with an L* value of less than
about 30 with specular component included, and a heating build-Lip
(HBU) as measured according to ASTM D4803-89 of less than about
34.degree. C.
[0006] In another embodiment the present invention is a method for
preparing an article comprising a rubber modified thermoplastic
resin comprising a discontinuous elastomeric phase dispersed in a
rigid thermoplastic phase, wherein at least a portion of the rigid
thermoplastic phase is grafted to the elastomeric phase; and
wherein the elastomeric phase comprises a polymer having structural
units derived from butyl acrylate; and wherein the rigid
thermoplastic phase comprises structural units derived from
styrene, acrylonitrile, and optionally methyl methacrylate, wherein
the article has an L* value of less than about 30 with specular
component included, and a heating build-up (HBU) as measured
according to ASTM D4803-89 of less than about 34.degree. C.; which
method comprises the step of combining the resin with a colorant
combination comprising an inorganic infrared reflecting pigment and
at least two organic colorants, wherein the inorganic infrared
reflecting pigment is selected from the group consisting of a
chromium iron oxide, a black spinel, and chrome iron nickel black
spinel, and is present in an amount greater than or equal to about
0.5 parts per hundred parts resinous components by weight (phr);
and wherein the organic colorant comprises at least two colorants
selected from the group consisting of Solvent Green 3, Solvent Red
135, Solvent Violet 13, Pigment Blue 15:4, Pigment Black 31,
Disperse Violet 31/26, and mixtures thereof, and is present in a
total amount greater than or equal to about 0.5 phr.
[0007] Embodiments of the invention also include articles
comprising the compositions. Various other features, aspects, and
advantages of the present invention will become more apparent with
reference to the following description and appended claims.
DETAILED DESCRIPTION
[0008] In the following specification and the claims which follow,
reference will be made to a number of terms which shall be defined
to have the following meanings. The singular forms "a", "an" and
"the" include plural referents unless the context clearly dictates
otherwise. The terminology "monoethylenically unsaturated" means
having a single site of ethylenic unsaturation per molecule. The
terminology "polyethylenically unsaturated" means having two or
more sites of ethylenic unsaturation per molecule. The terminology
"(meth)acrylate" refers collectively to acrylate and methacrylate;
for example, the term "(meth)acrylate monomers" refers collectively
to acrylate monomers and methacrylate monomers. The term
"(meth)acrylamide" refers collectively to acrylamides and
methacrylamides; for example, the term "(meth)acrylamide monomers"
refers collectively to acrylamide monomers and methacrylamide
monomers.
[0009] The term "alkyl" as used in the various embodiments of the
present invention is intended to designate linear alkyl, branched
alkyl, aralkyl, cycloalkyl, bicycloalkyl, tricycloalkyl and
polycycloalkyl radicals containing carbon and hydrogen atoms, and
optionally containing atoms in addition to carbon and hydrogen, for
example atoms selected from Groups 15, 16 and 17 of the Periodic
Table. Alkyl groups may be saturated or unsaturated, and may
comprise, for example, vinyl or allyl. The term "alkyl" also
encompasses that alkyl portion of alkoxide groups. In various
embodiments normal and branched alkyl radicals are those containing
from 1 to about 32 carbon atoms, and include as illustrative
non-limiting examples C.sub.1-C.sub.32 alkyl (optionally
substituted with one or more groups selected from C.sub.1-C.sub.32
alkyl, C.sub.3-C.sub.15 cycloalkyl or aryl); and C.sub.3-C.sub.15
cycloalkyl optionally substituted with one or more groups selected
from C.sub.1-C.sub.32 alkyl. Some particular illustrative examples
comprise methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl,
tertiary-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl,
decyl, undecyl and dodecyl. Some illustrative non-limiting examples
of cycloalkyl and bicycloalkyl radicals include cyclobutyl,
cyclopentyl, cyclohexyl, methylcyclohexyl, cycloheptyl,
bicycloheptyl and adamantyl. In various embodiments aralkyl
radicals are those containing from 7 to about 14 carbon atoms;
these include, but are not limited to, benzyl, phenylbutyl,
phenylpropyl, and phenylethyl. The term "aryl" as used in the
various embodiments of the present invention is intended to
designate substituted or unsubstituted aryl radicals containing
from 6 to 20 ring carbon atoms. Some illustrative non-limiting
examples of these aryl radicals include C.sub.6-C.sub.20 aryl
optionally substituted with one or more groups selected from
C.sub.1-C.sub.32 alkyl, C.sub.3-C.sub.15 cycloalkyl, aryl, and
functional groups comprising atoms selected from Groups 15, 16 and
17 of the Periodic Table. Some particular illustrative examples of
aryl radicals comprise substituted or unsubstituted phenyl,
biphenyl, tolyl, naphthyl and binaphthyl.
[0010] Compositions of the present invention comprise a rubber
modified thermoplastic resin comprising a discontinuous elastomeric
phase dispersed in a rigid thermoplastic phase, wherein at least a
portion of the rigid thermoplastic phase is grafted to the
elastomeric phase. The rubber modified thermoplastic resin employs
at least one rubber substrate for grafting. The rubber substrate
comprises the discontinuous elastomeric phase of the composition.
There is no particular limitation on the rubber substrate provided
it is susceptible to grafting by at least a portion of a graftable
monomer. In some embodiments suitable rubber substrates comprise
dimethyl siloxane/butyl acrylate rubber, or silicone/butyl acrylate
composite rubber; polyolefin rubbers such as ethylene-propylene
rubber or ethylene-propylene-diene (EPDM) rubber; or silicone
rubber polymers such as polymethyl siloxane rubber. The rubber
substrate typically has a glass transition temperature, Tg, in one
embodiment less than or equal to 25.degree. C., in another
embodiment below about 0.degree. C., in another embodiment below
about minus 20.degree. C., and in still another embodiment below
about minus 30.degree. C. As referred to herein, the Tg of a
polymer is the T value of polymer as measured by differential
scanning calorimetry (DSC; heating rate 20.degree. C./minute, with
the Tg value being determined at the inflection point).
[0011] In one embodiment the rubber substrate is derived from
polymerization by known methods of at least one monoethylenically
unsaturated alkyl (meth)acrylate monomer selected from
(C.sub.1-C.sub.12)alkyl(meth)acrylate monomers and mixtures
comprising at least one of said monomers. As used herein, the
terminology "(C.sub.x-C.sub.y)" as applied to a particular unit,
such as, for example, a chemical compound or a chemical substituent
group, means having a carbon atom content of from "x" carbon atoms
to "y" carbon atoms per such unit. For example,
"(C.sub.1-C.sub.12)alkyl" means a straight chain, branched or
cyclic alkyl substituent group having from 1 to 12 carbon atoms per
group. Suitable (C.sub.1-C.sub.12)alkyl(meth)acrylate monomers
include, but are not limited to, (C.sub.1-C.sub.12)alkyl acrylate
monomers, illustrative examples of which comprise ethyl acrylate,
butyl acrylate, iso-pentyl acrylate, n-hexyl acrylate, and 2-ethyl
hexyl acrylate; and their (C.sub.1-C.sub.12)alkyl methacrylate
analogs, illustrative examples of which comprise methyl
methacrylate, ethyl methacrylate, propyl methacrylate, iso-propyl
methacrylate, butyl methacrylate, hexyl methacrylate, and decyl
methacrylate. In a particular embodiment of the present invention
the rubber substrate comprises structural units derived from
n-butyl acrylate.
[0012] In various embodiments the rubber substrate may also
optionally comprise a minor amount, for example up to about 5 wt.
%, of structural units derived from at least one polyethylenically
unsaturated monomer, for example those that are copolymerizable
with a monomer used to prepare the rubber substrate. A
polyethylenically unsaturated monomer is often employed to provide
cross-linking of the rubber particles and/or to provide
"graftlinking" sites in the rubber substrate for subsequent
reaction with grafting monomers. Suitable polyethylenically
unsaturated monomers include, but are not limited to, butylene
diacrylate, divinyl benzene, butene diol dimethacrylate,
trimethylolpropane tri(meth)acrylate, allyl methacrylate, diallyl
methacrylate, diallyl maleate, diallyl fumarate, diallyl phthalate,
triallyl methacrylate, triallyl cyanurate, triallyl isocyanurate,
the acrylate of tricyclodecenylalcohol and mixtures comprising at
least one of such monomers. In a particular embodiment the rubber
substrate comprises structural units derived from triallyl
cyanurate.
[0013] In some embodiments the rubber substrate may optionally
comprise structural units derived from minor amounts of other
unsaturated monomers, for example those that are copolymerizable
with a monomer used to prepare the rubber substrate. In particular
embodiments the rubber substrate may optionally include up to about
25 wt. % of structural units derived from one or more monomers
selected from (meth)acrylate monomers, alkenyl aromatic monomers
and monoethylenically unsaturated nitrile monomers. Suitable
copolymerizable (meth)acrylate monomers include, but are not
limited to, C.sub.1-C.sub.12 aryl or haloaryl substituted acrylate,
C.sub.1-C.sub.12 aryl or haloaryl substituted methacrylate, or
mixtures thereof, monoethylenically unsaturated carboxylic acids,
such as, for example, acrylic acid, methacrylic acid and itaconic
acid; glycidyl(meth)acrylate, hydroxy alkyl(meth)acrylate,
hydroxy(C.sub.1-C.sub.12)alkyl(meth)acrylate, such as, for example,
hydroxyethyl methacrylate;
(C.sub.4-C.sub.12)cycloalkyl(meth)acrylate monomers, such as, for
example, cyclohexyl methacrylate; (meth)acrylamide monomers, such
as, for example, acrylamide, methacrylamide and
N-substituted-acrylamide or N-substituted-methacrylamides;
maleimide monomers, such as, for example, maleimide, N-alkyl
maleimides, N-aryl maleimides, N-phenyl maleimide, and haloaryl
substituted maleimides; maleic anhydride; methyl vinyl ether, ethyl
vinyl ether, and vinyl esters, such as, for example, vinyl acetate
and vinyl propionate. Suitable alkenyl aromatic monomers include,
but are not limited to, vinyl aromatic monomers, such as, for
example, styrene and substituted styrenes having one or more alkyl,
alkoxy, hydroxy or halo substituent groups attached to the aromatic
ring, including, but not limited to, alpha-methyl styrene, p-methyl
styrene, 3,5-diethylstyrene, 4-n-propylstyrene, 4-isopropylstyrene,
vinyl toluene, alpha-methyl vinyl toluene, vinyl xylene, trimethyl
styrene, butyl styrene, t-butyl styrene, chlorostyrene,
alpha-chlorostyrene, dichlorostyrene, tetrachlorostyrene,
bromostyrene, alpha-bromostyrene, dibromostyrene, p-hydroxystyrene,
p-acetoxystyrene, methoxystyrene and vinyl-substituted condensed
aromatic ring structures, such as, for example, vinyl naphthalene,
vinyl anthracene, as well as mixtures of vinyl aromatic monomers
and monoethylenically unsaturated nitrile monomers such as, for
example, acrylonitrile, ethacrylonitrile, methacrylonitrile,
alpha-bromoacrylonitrile and alpha-chloro acrylonitrile.
Substituted styrenes with mixtures of substituents on the aromatic
ring are also suitable. As used herein, the term "monoethylenically
unsaturated nitrile monomer" means an acyclic compound that
includes a single nitrile group and a single site of ethylenic
unsaturation per molecule and includes, but is not limited to,
acrylonitrile, methacrylonitrile, alpha-chloro acrylonitrile, and
the like.
[0014] In a particular embodiment the rubber substrate comprises
repeating units derived from one or more (C.sub.1-C.sub.12)alkyl
acrylate monomers. In still another particular embodiment, the
rubber substrate comprises from 40 to 95 wt. % repeating units
derived from one or more (C.sub.1-C.sub.12)alkyl acrylate monomers,
and more preferably from one or more monomers selected from ethyl
acrylate, butyl acrylate and n-hexyl acrylate.
[0015] The rubber substrate may be present in the rubber modified
thermoplastic resin in one embodiment at a level of from about 4
wt. % to about 94 wt. %; in another embodiment at a level of from
about 10 wt. % to about 80 wt. %; in another embodiment at a level
of from about 15 wt. % to about 80 wt. %; in another embodiment at
a level of from about 35 wt. % to about 80 wt. %; in another
embodiment at a level of from about 40 wt. % to about 80 wt. %; in
another embodiment at a level of from about 25 wt. % to about 60
wt. %, and in still another embodiment at a level of from about 40
wt. % to about 50 wt. %, based on the weight of the rubber modified
thermoplastic resin. In other embodiments the rubber substrate may
be present in the rubber modified thermoplastic resin at a level of
from about 5 wt. % to about 50 wt. %; at a level of from about 8
wt. % to about 40 wt. %; or at a level of from about 10 wt. % to
about 30 wt. %, based on the weight of the particular rubber
modified thermoplastic resin.
[0016] There is no particular limitation on the particle size
distribution of the rubber substrate (sometimes referred to
hereinafter as initial rubber substrate to distinguish it from the
rubber substrate following grafting). In some embodiments the
initial rubber substrate may possess a broad, essentially
monomodal, particle size distribution with particles ranging in
size from about 50 nanometers (nm) to about 1000 nm. In other
embodiments the mean particle size of the initial rubber substrate
may be less than about 100 nm. In still other embodiments the mean
particle size of the initial rubber substrate may be in a range of
between about 80 nm and about 400 nm. In other embodiments the mean
particle size of the initial rubber substrate may be greater than
about 400 nm. In still other embodiments the mean particle size of
the initial rubber substrate may be in a range of between about 400
nm and about 750 nm. In still other embodiments the initial rubber
substrate comprises particles which are a mixture of particle sizes
with at least two mean particle size distributions. In a particular
embodiment the initial rubber substrate comprises a mixture of
particle sizes with each mean particle size distribution in a range
of between about 80 nm and about 750 nm. In another particular
embodiment the initial rubber substrate comprises a mixture of
particle sizes, one with a mean particle size distribution in a
range of between about 80 nm and about 400 nm; and one with a broad
and essentially monomodal mean particle size distribution.
[0017] The rubber substrate may be made according to known methods,
such as, but not limited to, a bulk, solution, or emulsion process.
In one non-limiting embodiment the rubber substrate is made by
aqueous emulsion polymerization in the presence of a free radical
initiator, e.g., an azonitrile initiator, an organic peroxide
initiator, a persulfate initiator or a redox initiator system, and,
optionally, in the presence of a chain transfer agent, e.g., an
alkyl mercaptan, to form particles of rubber substrate.
[0018] The rigid thermoplastic resin phase of the rubber modified
thermoplastic resin comprises one or more thermoplastic polymers.
In one embodiment of the present invention monomers are polymerized
in the presence of the rubber substrate to thereby form a rigid
thermoplastic phase, at least a portion of which is chemically
grafted to the elastomeric phase. The portion of the rigid
thermoplastic phase chemically grafted to rubber substrate is
sometimes referred to hereinafter as grafted copolymer. The rigid
thermoplastic phase comprises a thermoplastic polymer or copolymer
that exhibits a glass transition temperature (Tg) in one embodiment
of greater than about 25.degree. C., in another embodiment of
greater than or equal to 90.degree. C., and in still another
embodiment of greater than or equal to 100.degree. C.
[0019] In a particular embodiment the rigid thermoplastic phase
comprises a polymer having structural units derived from one or
more monomers selected from the group consisting of
(C.sub.1-C.sub.12)alkyl-(meth)acrylate monomers,
aryl-(meth)acrylate monomers, alkenyl aromatic monomers and
monoethylenically unsaturated nitrile monomers. Suitable
(C.sub.1-C.sub.12)alkyl-(meth)acrylate and aryl-(meth)acrylate
monomers, alkenyl aromatic monomers and monoethylenically
unsaturated nitrile monomers include those set forth hereinabove in
the description of the rubber substrate. In addition, the rigid
thermoplastic resin phase may, provided that the Tg limitation for
the phase is satisfied, optionally include up to about 10 wt. % of
third repeating units derived from one or more other
copolymerizable monomers.
[0020] The rigid thermoplastic phase typically comprises one or
more alkenyl aromatic polymers. Suitable alkenyl aromatic polymers
comprise at least about 20 wt. % structural units derived from one
or more alkenyl aromatic monomers. In a particular embodiment
suitable alkenyl aromatic polymers comprise structural units
derived from one or more alkenyl aromatic monomers and present in a
range of between about 20 wt. % and about 50 wt. %, based on the
total weight of monomers added to form the copolymer comprising the
grafted copolymer and the rigid thermoplastic phase. In one
embodiment the rigid thermoplastic phase comprises an alkenyl
aromatic polymer having structural units derived from one or more
alkenyl aromatic monomers and from at least one other polymerizable
monomer. Examples of such alkenyl aromatic polymers include, but
are not limited to, styrene/acrylonitrile copolymers,
alpha-methylstyrene/acrylonitrile copolymers,
alpha-methylstyrene/styrene/acrylonitrile copolymers,
styrene/N-aryl maleimide copolymers, and styrene/N-phenyl maleimide
copolymers. In another particular embodiment the rigid
thermoplastic phase comprises an alkenyl aromatic polymer having
structural units derived from one or more alkenyl aromatic
monomers; from one or more monoethylenically unsaturated nitrile
monomers; and from one or more monomers selected from the group
consisting of (C.sub.1-C.sub.12)alkyl- and aryl-(meth)acrylate
monomers. Examples of such alkenyl aromatic polymers include, but
are not limited to, styrene/acrylonitrile/methyl methacrylate
copolymers, alpha-methylstyrene/acrylonitrile/methyl methacrylate
copolymers and alpha-methylstyrene/styrene/acrylonitrile/methyl
methacrylate copolymers. Further examples of suitable alkenyl
aromatic polymers comprise styrene/methyl methacrylate copolymers,
styrene/maleic anhydride copolymers; styrene/acrylonitrile/maleic
anhydride copolymers, and styrene/acrylonitrile/acrylic acid
copolymers. These copolymers may be used for the rigid
thermoplastic phase either individually or as mixtures.
[0021] When structural units in copolymers are derived from one or
more monoethylenically unsaturated nitrile monomers, then the
amount of nitrile monomer added to form the copolymer comprising
the grafted copolymer and the rigid thermoplastic phase may be in
one embodiment in a range of between about 5 wt. % and about 40 wt.
%, in another embodiment in a range of between about 5 wt. % and
about 30 wt. %, in another embodiment in a range of between about
10 wt. % and about 30 wt. %, and in yet another embodiment in a
range of between about 15 wt. % and about 30 wt. %, based on the
total weight of monomers added to form the copolymer comprising the
grafted copolymer and the rigid thermoplastic phase. In a
particular embodiment the amount of nitrile monomer added to form
the copolymer comprising the grafted copolymer and the rigid
thermoplastic phase may be in a range of between about 10 wt. % and
about 20 wt. %, based on the total weight of monomers added to form
the copolymer comprising the grafted copolymer and the rigid
thermoplastic phase.
[0022] When structural units in copolymers are derived from one or
more (C.sub.1-C.sub.12)alkyl- and/or aryl-(meth)acrylate monomers,
then the amount of the said monomer(s) added to form the copolymer
comprising the grafted copolymer and the rigid thermoplastic phase
may be in one embodiment in a range of between about 5 wt. % and
about 50 wt. %, in another embodiment in a range of between about 5
wt. % and about 45 wt. %, in another embodiment in a range of
between about 5 wt. % and about 35 wt. %, and in yet another
embodiment in a range of between about 15 wt. % and about 35 wt. %,
based on the total weight of monomers added to form the copolymer
comprising the grafted copolymer and the rigid thermoplastic phase.
In a particular embodiment when structural units in copolymers are
derived from one or more (C.sub.1-C.sub.12)alkyl- and/or
aryl-(meth)acrylate monomers, then the amount of the said
monomer(s) added to form the copolymer comprising the grafted
copolymer and the rigid thermoplastic phase may be in a range of
between about 20 wt. % and about 50 wt. %, based on the total
weight of monomers added to form the copolymer comprising the
grafted copolymer and the rigid thermoplastic phase.
[0023] When structural units in polymers in the rigid thermoplastic
phase are derived from monomers comprising at least one
(C.sub.1-C.sub.12)alkyl- and aryl-(meth)acrylate monomer, then the
wt./wt. ratio of said (meth)acrylate monomer to the totality of
other monomers from which said rigid thermoplastic phase is derived
is in one embodiment in a range of between about 10:1 and about
1:10; in another embodiment in a range of between about 8:1 and
about 1:8; in another embodiment in a range of between about 5:1
and about 1:5; in another embodiment in a range of between about
3:1 and about 1:3; in another embodiment in a range of between
about 2:1 and about 1:2; and in yet another embodiment in a range
of between about 1.5:1 and about 1:1.5. In particular embodiments
when at least one (C.sub.1-C.sub.12)alkyl- or aryl-(meth)acrylate
monomer, at least one vinyl aromatic monomer, and optionally at
least one monoethylenically unsaturated nitrile monomer are
employed as monomers in the rigid thermoplastic phase, the wt./wt.
ratio of said monomers is, respectively, in one embodiment in a
range of from about 80/20/0 to about 20/60/20, in another
embodiment in a range of from about 60/30/10 to about 45/30/25, and
in still another embodiment in a range of from about 45/40/15 to
about 35/40/25.
[0024] The amount of grafting that takes place between the rubber
substrate and monomers comprising the rigid thermoplastic phase
varies with the relative amount and composition of the elastomeric
phase. In one embodiment, greater than about 10 wt. % of the rigid
thermoplastic phase is chemically grafted to the rubber substrate,
based on the total amount of rigid thermoplastic phase in the
composition. In another embodiment, greater than about 15 wt. % of
the rigid thermoplastic phase is chemically grafted to the rubber
substrate, based on the total amount of rigid thermoplastic phase
in the composition. In still another embodiment, greater than about
20 wt. % of the rigid thermoplastic phase is chemically grafted to
the rubber substrate, based on the total amount of rigid
thermoplastic phase in the composition. In particular embodiments
the amount of rigid thermoplastic phase chemically grafted to the
rubber substrate may be in a range of between about 5 wt. % and
about 90 wt. %; between about 10 wt. % and about 90 wt. %; between
about 15 wt. % and about 85 wt. %; between about 15 wt. % and about
50 wt. %; or between about 20 wt. % and about 50 wt. %, based on
the total amount of rigid thermoplastic phase in the composition.
In yet other embodiments, about 40 wt. % to 90 wt. % of the rigid
thermoplastic phase is free, that is, non-grafted.
[0025] The rigid thermoplastic phase may be present in the rubber
modified thermoplastic resin in one embodiment at a level of from
about 85 wt. % to about 6 wt. %; in another embodiment at a level
of from about 65 wt. % to about 6 wt. %; in another embodiment at a
level of from about 60 wt. % to about 20 wt. %; in another
embodiment at a level of from about 75 wt. % to about 40 wt. %, and
in still another embodiment at a level of from about 60 wt. % to
about 50 wt. %, based on the weight of the rubber modified
thermoplastic resin. In other embodiments the rigid thermoplastic
phase may be present in a range of between about 90 wt. % and about
30 wt. %, based on the weight of the rubber modified thermoplastic
resin.
[0026] The rigid thermoplastic phase may be formed solely by
polymerization carried out in the presence of rubber substrate, or
by addition of one or more separately synthesized rigid
thermoplastic polymers to the rubber modified thermoplastic resin
comprising the composition. In some embodiments the separately
synthesized rigid thermoplastic polymer comprises structural units
essentially identical to those of the rigid thermoplastic phase
comprising the rubber modified thermoplastic resin. In some
particular embodiments the separately synthesized rigid
thermoplastic polymer is a copolymer comprising structural units
derived from styrene and acrylonitrile (SAN); alpha-methylstyrene
and acrylonitrile; alpha-methylstyrene, styrene, and acrylonitrile;
styrene, acrylonitrile, and methyl methacrylate; alpha-methyl
styrene, acrylonitrile, and methyl methacrylate; or
alpha-methylstyrene, styrene, acrylonitrile, and methyl
methacrylate. When at least a portion of separately synthesized
rigid thermoplastic polymer is added to the rubber modified
thermoplastic resin, then the amount of said separately synthesized
rigid thermoplastic polymer added is in one embodiment in a range
of between about 5 wt. % and about 90 wt. %, in another embodiment
in a range of between about 5 wt. % and about 80 wt. %, in another
embodiment in a range of between about 10 wt. % and about 70 wt. %,
in another embodiment in a range of between about 15 wt. % and
about 65 wt. %, and in still another embodiment in a range of
between about 20 wt. % and about 65 wt. %, based on the weight of
resinous components in the composition.
[0027] Two or more different rubber substrates, each possessing a
different mean particle size, may be separately employed in a
polymerization reaction to prepare rigid thermoplastic phase, and
then the products blended together to make the rubber modified
thermoplastic resin. In illustrative embodiments wherein such
products each possessing a different mean particle size of initial
rubber substrate are blended together, then the ratios of said
substrates may be in a range of about 90:10 to about 10:90, or in a
range of about 80:20 to about 20:80, or in a range of about 70:30
to about 30:70. In some embodiments an initial rubber substrate
with smaller particle size is the major component in such a blend
containing more than one particle size of initial rubber
substrate.
[0028] The rigid thermoplastic phase may be made according to known
processes, for example, mass polymerization, emulsion
polymerization, suspension polymerization or combinations thereof,
wherein at least a portion of the rigid thermoplastic phase is
chemically bonded, i.e., "grafted" to the elastomeric phase via
reaction with unsaturated sites present in the elastomeric phase.
The grafting reaction may be performed in a batch, continuous or
semi-continuous process. Representative procedures include, but are
not limited to, those taught in U.S. Pat. No. 3,944,631; and in
U.S. patent application Ser. No. 08/962,458, filed Oct. 31, 1997.
The unsaturated sites in the elastomeric phase are provided, for
example, by residual unsaturated sites in those structural units of
the rubber substrate that were derived from a graftlinking monomer.
In some embodiments of the present invention monomer grafting to
rubber substrate with concomitant formation of rigid thermoplastic
phase may optionally be performed in stages wherein at least one
first monomer is grafted to rubber substrate followed by at least
one second monomer different from said first monomer.
Representative procedures for staged monomer grafting to rubber
substrate include, but are not limited to, those taught in commonly
assigned U.S. patent application Ser. No. 10/748,394, filed Dec.
30, 2003.
[0029] In a preferred embodiment the rubber modified thermoplastic
resin is an ASA graft copolymer such as that manufactured and sold
by General Electric Company under the trademark GELOY.RTM., or an
acrylate-modified acrylonitrile-styrene-acrylate graft copolymer.
ASA polymeric materials include, for example, those disclosed in
U.S. Pat. No. 3,711,575. Acrylonitrile-styrene-acrylate graft
copolymers comprise those described for example in commonly
assigned U.S. Pat. Nos. 4,731,414 and 4,831,079. In some
embodiments of the invention where an acrylate-modified ASA is
used, the ASA component further comprises an additional
acrylate-graft formed from monomers selected from the group
consisting of C.sub.1 to C.sub.12 alkyl- and aryl-(meth)acrylate as
part of either the rigid phase, the elastomeric phase, or both.
Such copolymers are referred to as acrylate-modified
acrylonitrile-styrene-acrylate graft copolymers, or
acrylate-modified ASA. A preferred monomer is methyl methacrylate
to result in a PMMA-modified ASA (sometimes referred to hereinafter
as "MMA-ASA").
[0030] Compositions of the invention comprise at least one
inorganic infrared reflecting pigment. The pigment is not
particularly limited provided that it hardly absorbs infrared
radiation. Illustrative inorganic infrared reflecting pigments
comprise: metal oxides, mixed metal oxides, titanates, aluminates,
metal carbonates, iron oxides, chromium oxides, ultramarines,
stainless steel powder, mica powder covered with titanium oxide or
metal sulfides (including rare-earth sulfides). In particular
embodiments inorganic infrared reflecting pigments comprise
chromium iron oxides or black spinels, such as but not limited to,
chrome iron nickel black spinel. Illustrative examples of these
materials are available under the names "Black 1", "Black 462",
"Black 376", and "Black 411" from The Shepherd Color Company,
Cincinnati, Ohio.
[0031] Compositions of the invention comprise at least one organic
colorant. In some embodiments organic colorants are non-absorbing
in the infrared. Illustrative organic colorants comprise those
which contribute to the production of a dark or a black color in
molded parts of the compositions. Suitable organic colorants may be
employed either alone or as mixtures comprising more than one
organic colorant in embodiments of compositions of the invention.
In some particular embodiments at least two organic colorants may
be employed to produce either a dark or a black color. Illustrative
organic colorants are derived from the class of anthraquinone, azo,
phthalic anhydride, phthalocyanine, indigo/thioindigo, azomethine,
azomethine-azo, dioxazine, quinacridone, isoindolinone,
isoindoline, diketopyrrolopyrrole, perylene, or perinone organic
colorants, or mixtures thereof. Other illustrative examples of
particular examples of organic colorants that produce a dark or a
black color include but are not limited to mixtures of Solvent
Green 3 and Solvent Red 135 or Solvent Green 3, Solvent Violet 13,
and Pigment Blue 15:4 as referenced in the Color Index.
Additionally, when a dark color is to be produced, azomethine
system organic pigments such as CHROMOFINE.RTM. Black A-1103, a
trademarked product produced by Dainichiseika Color & Chemicals
Mfg. Co., Ltd., and perylene system pigments such as PALIOGEN.RTM.
Black S 0084 (C.I. Pigment Black 31), a trademarked product
produced by BASF Corporation, may be employed, and these may be
dispersed in the resin component either singly or in combination
with other pigments. In other embodiments particular examples of
organic colorants comprise MACROLEX.RTM. Green 5B Gran, which is an
anthraquinone dyestuff, MACROLEX.RTM. Red EG Gran, which is a
perinone dyestuff, and MACROLEX.RTM. Red Violet R Gran also known
as Disperse Violet 31/26, C.A.S. #6408-72-6,
1,4-diamino-2,3-diphenoxyanthraquinone, obtained from Lanxess
Corporation. Other illustrative examples of suitable organic
colorants may be found in U.S. Pat. No. 6,521,038.
[0032] The amounts of inorganic infrared reflecting pigment and
organic colorant in embodiments of compositions of the invention
are those amounts effective to provide a colorant combination
comprising at least one inorganic infrared reflecting pigment and
at least one organic colorant resulting in a molded part with an L*
value of less than about 30 with specular component included and a
heating build-up (HBU) of less than about 34.degree. C. In various
embodiments the total amount of inorganic infrared reflecting
pigment is greater than or equal to about 0.05 parts per hundred
parts resinous components (phr). In a preferred embodiment the
total loading of IRR pigment is greater than or equal to about 0.75
phr and the total loading of organic colorant greater than or equal
to about 0.5 phr. In another preferred embodiment the total loading
of IRR pigment is greater than or equal to about 1 phr and the
total loading of organic colorant greater than or equal to about
0.8 phr. In still other preferred embodiments the total loading of
IRR pigment is greater than or equal to about 2 phr and the total
loading of organic colorant is greater than or equal to about 1
phr. When more than one organic colorant is present in embodiments
of the compositions, then the amount of any one organic colorant
may be greater than or equal to about 0.005 phr, preferably greater
than or equal to about 0.01 phr, and more preferably greater than
or equal to about 0.05 phr. In other embodiments the total loading
of IRR pigment is less than or equal to about 5 phr, preferably
less than or equal to about 4 phr. In still other embodiments the
total loading of organic colorant is less than or equal to about 4
phr, preferably less than or equal to about 3 phr.
[0033] Thermoplastic resin compositions in embodiments of the
present invention may optionally comprise various conventional
additives, such as, but not limited to: (1) antioxidants, such as,
for example, organophosphites, for example,
tris(nonyl-phenyl)phosphite,
(2,4,6-tri-tert-butylphenyl)(2-butyl-2-ethyl-1,3-propanediol)phosphite,
bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite or distearyl
pentaerythritol diphosphite, as well as alkylated monophenols,
polyphenols, alkylated reaction products of polyphenols with
dienes, such as, for example, butylated reaction products of
para-cresol and dicyclopentadiene, alkylated hydroquinones,
hydroxylated thiodiphenyl ethers, alkylidene-bisphenols, benzyl
compounds, acylaminophenols, esters of
beta-(3,5-di-tert-butyl-4-hydroxyphenol)-propionic acid with
monohydric or polyhydric alcohols, esters of
beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid with
monohydric or polyhydric alcohols, esters of
beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with
mono- or polyhydric alcohols, esters of thioalkyl or thioaryl
compounds, such as, for example, distearylthiopropionate,
dilaurylthiopropionate, ditridecylthiodipropionate, or amides of
beta-(3,5-di-tert-butyl-4-hydroxyphenol)-propionic acid; (2) UV
absorbers and light stabilizers such as, for example, HALS,
2-(2'-hydroxyphenyl)-benzotriazoles, 2-hydroxy-benzophenones,
esters of substituted or unsubstituted benzoic acids, acrylates, or
nickel compounds; (3) metal deactivators, such as, for example,
N,N'-diphenyloxalic acid diamide, or
3-salicyloylamino-1,2,4-triazole; (4) peroxide scavengers, such as,
for example, (C.sub.10-C.sub.20)alkyl esters of
beta-thiodipropionic acid, or mercapto benzimidazole; (5) basic
co-stabilizers, such as, for example, melamine,
polyvinylpyrrolidone, triallyl cyanurate, urea derivatives,
hydrazine derivatives, amines, polyamides, or polyurethanes; (6)
sterically hindered amines such as, for example, triisopropanol
amine or the reaction product of
2,4-dichloro-6-(4-morpholinyl)-1,3,5-triazine with a polymer of
1,6-diamine, or N,N'-bis(2,2,4,6-tetramethyl-4-piperidenyl) hexane;
(7) neutralizers such as magnesium stearate, magnesium oxide, zinc
oxide, zinc stearate, calcium stearate, or hydrotalcite; (8) other
additives such as, for example, lubricants such as, for example,
pentaerythritol tetrastearate, EBS wax, or silicone fluids,
plasticizers, optical brighteners, pigments, dyes, colorants,
flameproofing agents, anti-static agents, or blowing agents; (9)
flame retardant additives such as, for example, halogen-containing
organic flame retardant compounds, organophosphate flame retardant
compounds, or borate flame retardant compounds; or (10) fillers,
illustrative examples of which comprise reinforcing fillers,
extending fillers, glass fibers, glass spheres, carbon fibers,
metal fibers, metal flakes, aluminum flakes, silica, silicates,
zeolites, titanium dioxide, stone powder, talc, lithopone, calcium
carbonate, diatomaceous earth, crushed quartz, clay, calcined clay,
kaolin, asbestos, cellulose, wood flour, cork, cotton and synthetic
textile fibers, or mixtures thereof. In particular embodiments
compositions of the invention further comprise an additive selected
from the group consisting of lubricants, neutralizers, stabilizers,
heat stabilizers, light stabilizers, antioxidants, UV screeners, UV
absorbers, and mixtures thereof.
[0034] In one embodiment the compositions of the present invention
may be prepared by mixing the components as described herein to
form a first mixture. The mixing can be typically carried out in
any conventional mixer like drum mixers, ribbon mixers, vertical
spiral mixers, Muller mixers, Henschel mixers, sigma mixers,
chaotic mixers, static mixers or the like. The first mixture is
then compounded under melt-mixing conditions using any conventional
method, such as extrusion kneading or roll kneading, a two-roll
mill, in a Banbury mixer or in a single screw or twin-screw
extruder, or in any high shear mixing device to mix the components
to produce an intimate mixture, and optionally, to reduce the
composition so formed to particulate form, for example, by
pelletizing or grinding the composition. The twin screw extruder,
when employed, can be co-rotating, counter rotating, intermeshing,
non-intermeshing, a planetary gear extruder, a co-continuous mixer,
or the like. The compounding process can be a continuous,
semi-continuous, or a batch process. In other embodiments all or a
portion of resin or additive, colorant or pigment, either neat or
in the form of a mixture, may be added to the composition at some
stage of a blending process, such as in an extrusion process. Those
of ordinary skill in the art will be able to adjust blending times,
as well as component addition location and sequence, without undue
additional experimentation. Also, optionally, a portion of the
rigid thermoplastic resin may be mixed with any additive, colorant
and/or pigment to prepare a master batch, and then the remaining
rigid thermoplastic resin may be added and mixed therewith later
for multistage mixture.
[0035] Compositions in embodiments of the present invention can be
molded into useful articles by a variety of means such as
injection, extrusion, coextrusion, rotary molding, blow molding or
thermoforming, or like methods to form articles. In some
embodiments the articles comprise unitary articles. Illustrative
unitary articles comprise a profile consisting essentially of a
composition of the present invention. In still other embodiments
the articles may comprise multilayer articles comprising at least
one layer comprising a composition of the present invention. In
various embodiments multilayer articles may comprise a cap-layer
comprising a composition of the invention and a substrate layer
comprising at least one thermoplastic resin different from said
cap-layer. Illustrative examples of articles include, but are not
limited to, Some particular suitable articles comprise outdoor and
indoor signs, and highway signs, articles for outdoor vehicle and
device (OVAD) applications; exterior and interior components for
automotive, truck, military and emergency vehicles (including
automotive and water-borne vehicles), scooter, bicycle, and
motorcycle, including panels, quarter panels, vertical panels,
horizontal panels, trim, pillars, center posts, doors, door frames,
decklids, trunklids, hoods, bonnets, roofs, fascia, pillar
appliques, cladding, body side moldings, wheel covers, window
frames, and license plate enclosures; enclosures, housings, panels,
and parts for outdoor vehicles and devices; enclosures for
electrical and telecommunication devices; electrical components;
outdoor furniture; aircraft components; boats and marine equipment,
including trim, enclosures, and housings; outboard motor housings;
depth finder housings, pools; spas; hot-tubs; steps; step
coverings; building and construction applications such as fencing,
roofs, siding, particularly vinyl siding applications; windows,
decorative window furnishings or treatments; wall panels, and
doors; enclosures, housings, panels, and parts for automatic teller
machines (ATM); enclosures, housings, panels, and parts for lawn
and garden tractors, lawn mowers, and tools, including lawn and
garden tools; window and door trim; toys; enclosures, housings,
panels, and parts for recreational vehicle panels and components;
playground equipment; articles made from plastic-wood combinations;
golf course markers; utility pit covers; mobile phone housings;
radio sender housings; radio receiver housings; light fixtures;
lighting appliances; reflectors; network interface device housings;
transformer housings; air conditioner housings; cladding or seating
for public transportation; cladding or seating for trains, subways,
or buses; meter housings; antenna housings; cladding for satellite
dishes; computer and business machine housings, home appliances and
media storage devices, such as, for example, audiovisual cassettes
and disk drive components; decking, desktops, pricing channels,
corner guards, gutters, handrails, down-spouts, fence posts, and
the like.
[0036] The following examples are included to provide additional
guidance to those skilled in the art in practicing the claimed
invention. The examples provided are merely representative of the
work that contributes to the teaching of the present application.
Accordingly, these examples are not intended to limit the
invention, as defined in the appended claims, in any manner.
[0037] In the following examples certain abbreviations have the
following meanings: "IRR" means infrared reflecting and "C.Ex."
means comparative example. Components used in the compositions were
as follows: The ASA resin employed comprised structural units
derived from 37.5 wt. % styrene, 18 wt. % acrylonitrile, and 44.5
wt. % butyl acrylate. The MMA-ASA resin employed comprised
structural units derived from 30.1 wt. % styrene, 13.7 wt. %
acrylonitrile, 11.1 wt. % methyl methacrylate, and 45 wt. % butyl
acrylate. The pigments and colorants were as follows:
[0038] "Conventional Black" was C.I. Pigment Black 7.
[0039] IRR Black 1 was "Black 376", a jet-black powder comprising
chrome iron nickel black spinel produced by high temperature
calcination and obtained from The Shepherd Color Company,
Cincinnati, Ohio.
[0040] IRR Black 2 was "Black 411", a brown-black powder comprising
chromium iron oxide produced by high temperature calcination and
obtained from The Shepherd Color Company, Cincinnati, Ohio.
[0041] Organic Colorant 1 was MACROLEX.RTM. Green 5B Gran, an
anthraquinone dyestuff obtained from Lanxess Corporation.
[0042] Organic Colorant 2 was MACROLEX.RTM. Red EG Gran, a perinone
dyestuff obtained from Lanxess Corporation.
[0043] Organic Colorant 3 was Disperse Violet 31/26, C.A.S.
#6408-72-6, 1,4-diamino-2,3-diphenoxyanthraquinone, MACROLEX.RTM.
Red Violet R Gran obtained from Lanxess Corporation.
[0044] Compositions comprising ASA or MMA-ASA and additives as
indicated in Table 1 were mixed in a Henschel mixer, and then
extruded using standard compounding conditions (for example, melt
temperature in a range of about 240.degree. C. to about 260.degree.
C.) and pelletized. Pellets of the compositions were injection
molded into color plaques of dimensions 62.4 mm.times.62.4 mm, and
3.2 mm thick. The heating build-up (HBU) due to the absorption of
solar energy in materials for outdoor application was measured
based upon data obtained by experimentally determining the total
solar reflectance (TSR) and the temperature rise above ambient
temperature under an ultraviolet heat lamp, relative to carbon
black according to ASTM D4803-89. TSR measurement was conducted
with a Solar Spectrum Reflectometer, model SSR-ER version 5.0,
equipped with a single tungsten filament source. Weathering
performance was characterized by color change (.DELTA.E) during
exposure in an Atlas Xenon arc accelerated weathering chamber
according to ASTM G26. Color measurements were done using a
Gretag-Macbeth 7000A spectrophotometer with integrating sphere and
with specular component included using CIE LAB D65 illuminant and
10 degree field of view. The term "specular component" corresponds
to specular reflection as defined in ASTM E284. Additionally, color
measurements were done using a Gretag-Macbeth CE-740 gonio
spectrophotometer with a specular angle of 45 degrees using CIE LAB
D65 illuminant, this latter mode being preferred since it enabled
discrimination between high gloss, jet black samples.
EXAMPLES 1-2 AND COMPARATIVE EXAMPLES 1-6
[0045] Different combinations of black pigment and
organic/inorganic colorants were evaluated for desired color space
and infrared reflection in ASA compositions. The compositions are
shown in Table 1. The amounts shown are phr values by weight with
the remaining material comprising either ASA or MMA-ASA. The
results of property measurements are presented in Table 2.
TABLE-US-00001 TABLE 1 IRR IRR Org. Org. Org. Ex. or Conv. Black
Black Color. Color. Color. C. Ex. Black 1 2 1 2 3 Ex. 1 -- 3 -- 0.8
0.8 0.05 Ex. 2 -- -- 3 0.8 0.8 -- C. Ex. 1 -- 3 -- -- -- -- C. Ex.
2 -- -- 3 -- -- -- C. Ex. 3 3 -- -- 0.8 0.8 -- C. Ex. 4 1 -- -- 0.8
0.8 -- C. Ex. 5 3 -- -- -- -- -- C. Ex. 6 1 -- 3 0.8 0.8 --
[0046] TABLE-US-00002 TABLE 2 Gretag-Macbeth Gretag-Macbeth Ex. or
HBU, TSR, 7000A CE-740 C. Ex. .degree. C. % .DELTA.E L* a* b* L* A*
B* Ex. 1 33.3 14.4 <2 28.1 -0.7 -2.8 14.4 -2.0 -6.3 Ex. 2 27.4
31.0 <2 29.1 -0.1 -2.0 16.4 -0.7 -4.0 C. Ex. 1 34.5 15.2 <2
32.4 0.4 -3.0 23.8 0.5 -5.5 C. Ex. 2 26.5 32.2 <2 33.8 3.8 -0.3
25.3 5.5 -1.1 C. Ex. 3 38.1 4.8 -- 27.0 -0.3 -0.8 8.5 -1.1 -2.5 C.
Ex. 4 38.5 4.9 -- 27.4 -0.5 -1.5 10.3 -1.6 -4.0 C. Ex. 5 38.9 4.9
-- 27.1 -0.1 -0.7 8.4 -0.5 -2.1 C. Ex. 6 38.8 5.5 -- 27.6 -0.2 -1.2
10.5 -0.6 -2.4
[0047] The results in Table 2 demonstrate that Examples 1 and 2
comprising at least one inorganic infrared reflecting pigment and
at least one organic colorant have a very good combination of low
HBU, low value for L*, and low value for .DELTA.E. Comparative
examples 1 and 2 containing at least one inorganic infrared
reflecting pigment but no organic colorant both show higher value
for L* than Examples 1 and 2. The comparative examples 3, 4, 5, and
6 containing conventional carbon black colorant all show higher
values for HBU than Examples 1 and 2. Preferred compositions of the
invention have a .DELTA.E of less than about 2 after 1250
kiloJoules per square meter (kJ/m.sup.2).
[0048] The compositions of the invention show a surprising
advantage in both low HBU, low value for L*, and good
weatherability as shown by low value for delta E. These advantages
are particularly beneficial for compositions to make dark molded
parts, such as dark brown, dark green, black, dark blue, dark gray,
dark red, and the like.
[0049] While the invention has been illustrated and described in
typical embodiments, it is not intended to be limited to the
details shown, since various modifications and substitutions can be
made without departing in any way from the spirit of the present
invention. As such, further modifications and equivalents of the
invention herein disclosed may occur to persons skilled in the art
using no more than routine experimentation, and all such
modifications and equivalents are believed to be within the spirit
and scope of the invention as defined by the following claims. All
patents and published articles cited herein are incorporated herein
by reference.
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