U.S. patent application number 13/422274 was filed with the patent office on 2012-11-08 for opaquely colored, infra-red plastics molding composition and methods of making the opaquely colored, infra-red plastics molding compostion.
This patent application is currently assigned to Evonik Roehm GmbH. Invention is credited to Ernst Becker, Elisabeth Clamer, Ursula Golchert, Klaus SCHULTES.
Application Number | 20120282396 13/422274 |
Document ID | / |
Family ID | 35456138 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120282396 |
Kind Code |
A1 |
SCHULTES; Klaus ; et
al. |
November 8, 2012 |
OPAQUELY COLORED, INFRA-RED PLASTICS MOLDING COMPOSITION AND
METHODS OF MAKING THE OPAQUELY COLORED, INFRA-RED PLASTICS MOLDING
COMPOSTION
Abstract
The invention relates to subduedly colored (brown, gray, black,
green), infrared reflecting PMMA compounds which can be applied to
other plastic compounds as an IR barrier layer
Inventors: |
SCHULTES; Klaus; (Wiesbaden,
DE) ; Becker; Ernst; (Bensheim, DE) ;
Golchert; Ursula; (Dieburg, DE) ; Clamer;
Elisabeth; (Darmstadt, DE) |
Assignee: |
Evonik Roehm GmbH
Darmstadt
DE
|
Family ID: |
35456138 |
Appl. No.: |
13/422274 |
Filed: |
March 16, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11720653 |
Jun 1, 2007 |
|
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PCT/EP05/11408 |
Oct 25, 2005 |
|
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13422274 |
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Current U.S.
Class: |
427/160 ;
524/407; 524/413 |
Current CPC
Class: |
C08J 2433/00 20130101;
C08K 3/013 20180101; C08L 33/04 20130101; C08J 7/0427 20200101;
C08L 25/12 20130101; C08L 33/12 20130101; C08L 33/04 20130101; C08L
2666/02 20130101; C08L 2666/06 20130101; C08L 33/12 20130101; C08K
2003/2251 20130101; C08J 2333/12 20130101 |
Class at
Publication: |
427/160 ;
524/413; 524/407 |
International
Class: |
B05D 5/06 20060101
B05D005/06; C08K 3/22 20060101 C08K003/22; C08K 3/10 20060101
C08K003/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 1, 2004 |
DE |
10 2004 058 083.9 |
Claims
1-9. (canceled)
10. An IR-reflective opaquely dark-colored molding composition
comprising: (a) from 95 to 99.5% by weight, based on the total
weight of the composition, of polymethyl (meth)acrylate; and (b)
from 5 to 0.5% by weight, based on the total weight of the
composition, of an IR-reflective pigment selected from the group
consisting of cobalt titanite green spinel having the CAS Number
68186-85-6, chromium oxide having the CAS Number 68909-79-5, iron
chromite brown spinel having the CAS Number 68187-09-7, chromium
iron oxide having the CAS Number 109414-04-2, nickel iron chromite
black spinel having the CAS Number 71631-15-7, and combinations
thereof, wherein the dark-colored molding composition, when
irradiated with a 60 W incandescent bulb with a voltage of 220 V,
at a distance of 50 mm from the dark-colored molding composition,
for 20 minutes, shows a temperature increase of 50.degree. C. or
less, and wherein the dark colored molding composition has a Cielab
L* value below 41.
11. The molding composition of claim 10, comprising the
IR-reflective pigment cobalt titanite green spinel having the CAS
Number 68186-85-6.
12. The molding composition of claim 10, comprising the
IR-reflective pigment chromium oxide having the CAS Number
1308-38-9.
13. The molding composition of claim 10, comprising the
IR-reflective pigment iron chromite brown spinel having the CAS
Number 68187-09-7.
14. The molding composition of claim 10, comprising the
IR-reflective pigment chromium iron oxide having the CAS Number
109414-04-2.
15. The molding composition of claim 10, comprising the
IR-reflective pigment nickel iron chromite black spinel having the
CAS Number 71631-15-7.
16. A method of producing a dark-colored plastic molding, the
method comprising coating a plastic molding with one or more layers
of the dark-colored molding composition according to claim 10.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/720,653 filed Jun. 1, 2007, which is a National Stage of
PCT/EP05/11408 filed Oct. 25, 2005 and claims the benefit of DE 10
2004 058 083.9 filed Dec. 1, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to opaquely colored,
infrared-reflective poly(meth)acrylate molding compositions which
can be applied as IR-barrier layer to further plastics
moldings.
[0004] 2. Prior Art
[0005] Because PMMA has very good properties, the corresponding
molding compositions are, inter alia, processed to give coextruded
layers, or processed as outer layers of in-mould-coated parts.
These layers serve as outer layer inter alia of foils, of sheets,
of profiles and of pipes, of which the main component or backing
layer is composed to some extent of other plastics. These plastics,
e.g. PVC, polystyrene, polycarbonate, ABS and ASA, have further
important properties, such as impact resistance and/or low
price.
[0006] Examples of applications for these coextrudates or
in-mould-coated articles are construction applications, such as
drainpipes and window frames; automobile applications, such as roof
modules, external and internal protective coverings (panels),
spoilers and mirror housings; household and sports applications,
e.g. protective coverings on tools, external panels for boats and
ski foils.
[0007] It is known that opaquely colored poly(meth)acrylate (PMMA)
molding compositions can be used for weathering-protection of
plastics moldings composed of, for example, polyvinyl chloride
(PVC).
[0008] The coated plastics molding is then provided with a colorant
such as TiO.sub.2, which reflects the IR radiation at the boundary
layer of the two plastics moldings and thus prevents excessive
heating of the article.
[0009] DE 27 19 170 (Dynamit Nobel) describes a process for
protection of PVC layers from the effects of sunlight via a layer
which has been durably applied to the PVC layer and which has been
equipped not only with UV stabilizers but also with IR reflectors.
The IR reflectors used comprise bleaching chromate molybdate red,
molybdate orange, chromium oxide green antimony sulfide, cadmium
sulfoselenide, cadmium sulfide, anthraquinone black pigment,
anthraquinone dark blue pigment, monoazo pigment or
phthalocyanines. Some of these pigments are no longer approved. A
PMMA not specified in any further detail is described as material
for the outer layer. DE 26 05 325 (Dynamit Nobel) likewise
describes a process for protection of PVC surfaces, and the
protective layer applied is colored sufficiently opaquely to
achieve maximum reflectance in the IR region and minimum
permeability in the UV region. The objective is achieved via the
use of at least one IR-reflective black pigment or IR-reflective
color pigment. For the darker color pigments, no predominantly
IR-absorptive pigments are used. The pigment used in the examples
comprises titanium dioxide or anthraquinone black in combination
with a UV absorber.
[0010] WO 00/24817 (Ferro) describes corundum-hematite structures
into which oxides of aluminum, of antimony, of bismuth, of boron,
of chromium, of cobalt, of gallium, of indium, of iron, of
lanthanum, of lithium, of magnesium, of manganese, of molybdenum,
of neodymium, of nickel, of niobium, of silicon, or of tin have
been bound.
OBJECT
[0011] The desire for dark-colored plastic moldings for outdoor
applications requires solution of some problems: [0012] the
plastics molding must be weather-resistant--irrespective of the
coloring [0013] there must be good and durable adhesion between
outer layer and plastics molding to be coated [0014] heating of the
plastics moldings via direct sunlight may not exceed a permissible
extent. The amount of heating may not become so great that the
article expands unacceptably and temperatures above the glass
transition temperature of the molding are reached. By way of
example, this can cause irreversible warping of a window frame and
prevent its subsequent opening [0015] the color pigments used must
themselves likewise be weathering-resistant, and also
toxicologically non-hazardous and inexpensive.
[0016] Further objects achieved by the inventive formulation
are:
[0017] the colored molding compositions are to have good
processibility
[0018] the formulation is to be stable at the processing
temperatures.
BRIEF SUMMARY OF INVENTION
[0019] If various infrared-reflective, inorganic color pigments are
used in a PMMA molding composition, these molding compositions can
be used to produce dark-colored plastics moldings, and other
plastics moldings can be coated with the abovementioned PMMA
molding compositions, these having a markedly lower heating rate on
insolation than moldings which are composed of conventionally
dark-colored PMMA or have been coated with the same.
[0020] It has now been found that use of pigments of the following
classes as described in Table 1
TABLE-US-00001 TABLE 1 Pigments that do not invoke excessive
heating in sunlight in plastic moldings. CAS Number C.I. Name C.I.
Number Chemical name 68186-85-6 C.I. Pigment C.I. 77377 Cobalt
titanite Green 50 green spinel 68909 79 5 C.I. Pigment C.I. 77288
Chromium oxide Green 17 109414-04-2 C.I. Pigment Chromium iron
Brown 29 oxide 68187-09-7 C.I. Pigment C.I. 77501 Iron chromite
Brown 35 brown spinel 71631-15-7 C.I. Pigment C.I. 77504 Nickel
iron chromite Black 30 black spinel
[0021] C.I. nomenclature according to Colour Index, The Society of
Dyers and Colourists (SDC) in PMMA molding compositions permits
preparation of opaquely dark-colored molding compositions without
excessive heating in sunlight of the plastics moldings equipped
therewith or of moldings produced with these materials. The
property "dark" can be defined via the L* value according to DIN
6174 (01/1979): Farbmetrische Bestimmung von Farbabstanden bei
Korperfarben nach der CieLab-formel [Colourimetric determination of
colour differences for mass tone colours by the CieLab formula].
The CieLab L* value for the opaquely dark-colored molding
compositions is below 51, preferably below 41 and very particularly
preferably below 31.
BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS
[0022] FIG. 1 depicts spectral graphs of reflectance [%] versus
wavelength [mm] for Comparison 1, Comparison 2 and Inventive
Example 1.
[0023] FIG. 2 depicts spectral graphs of reflectance [%] versus
wavelength [mm] for Comparison 3, Comparison 4 and Inventive
Example 4.
[0024] FIG. 3 depicts spectral graphs of reflectance [%] versus
wavelength [mm], without white background, for Comparison 1,
Comparison 2 and Inventive Example 1.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The amounts of the pigments or of their mixtures
incorporated into the molding compositions are from 0.05 to 5.0% by
weight preferably from 0.075 to 3.0% by weight and very
particularly preferably from 0.1 to 2% by weight.
[0026] Further colorants which are suitable for coloring of PMMA
molding compositions may be used additionally to vary the colour.
These colorants may be either IR-reflective--e.g. titanium
dioxide--or else non-IR-reflective. The proportion of these
additional colorants may be from 0 to 3.0%, preferably from 0 to
2.5% by weight and particularly preferably from 0 to 2.0% by
weight, based on the molding composition.
[0027] Dark colour shades are [0028] brown [0029] gray [0030] green
and [0031] black and mixed shades are also possible.
EXAMPLES
[0032] The molding composition Plexiglas.RTM. 7N is used as PMMA
component. It is available commercially from Rohm GmbH & Co.
KG.
[0033] The molding compositions of the present invention comprise
poly(meth)acrylates. The expression (meth)acrylates encompasses
methacrylates and acrylates and also mixtures of the two.
[0034] Poly(meth)acrylates are known to the person skilled in the
art. These polymers are generally obtained via free-radical
polymerization of mixtures which comprise (meth)acrylates.
[0035] These monomers are well known. Among these monomers are,
inter alia, (meth)acrylates which derive from saturated alcohols,
e.g. methyl (meth)acrylate, ethyl (meth)acrylate, propyl
(meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate,
pentyl (meth)acrylate and 2-ethylhexyl (meth)acrylate;
(meth)acrylates which derive from unsaturated alcohols, e.g. oleyl
(meth)acrylate, 2-propynyl (meth)acrylate, allyl (meth)acrylate,
vinyl (meth)acrylate; aryl (meth)acrylates, such as benzyl
(meth)acrylate or phenyl (meth)acrylate, where each of the aryl
radicals may be unsubstituted or have up to four substituents;
cycloalkyl (meth)acrylates, such as 3-vinylcyclohexyl
(meth)acrylate, bornyl (meth)acrylate, hydroxyalkyl
(meth)acrylates, such as 3-hydroxypropyl (meth)acrylate, [0036]
3,4-dihydroxybutyl (meth)acrylate, [0037] 2-hydroxyethyl
(meth)acrylate, 2-hydroxypropyl (meth)acrylate; [0038] glycol
di(meth)acrylates, such as 1,4-butanediol di(meth)acrylate, [0039]
(meth)acrylates of ether alcohols, such as tetrahydrofurfuryl
(meth)acrylate, vinyloxyethoxyethyl (meth)acrylate; amides and
nitriles of (meth)acrylic acid, such as
N-(3-dimethylaminopropyl)(meth)acrylamide, [0040]
N-(diethylphosphono)(meth)acrylamide, [0041]
1-methacryloylamido-2-methyl-2-propanol;
[0042] sulfur-containing methacrylates, such as ethylsulfinylethyl
(meth)acrylate,
[0043] 4-thiocyanatobutyl (meth)acrylate, ethylsulfonylethyl
(meth)acrylate, thiocyanatomethyl (meth)acrylate,
methylsulfinylmethyl (meth)acrylate, bis
((meth)acryloyloxyethyl)sulfide; multifunctional (meth)acrylates,
such as trimethyloylpropane tri(meth)acrylate.
[0044] The formulations to be polymerized may also comprise,
alongside the (meth)acrylates set out above, further unsaturated
monomers copolymerizable with the abovementioned (meth)acrylates.
The amount generally used of these compounds is from 0 to 50% by
weight, preferably from 0 to 40% by weight and particularly
preferably from 0 to 20% by weight, based on the weight of the
monomers, and the comonomers here may be used individually or in
the form of a mixture.
[0045] Among these are, inter alia, 1-alkenes, such a 1-hexene,
1-heptene; branched alkenes, such as vinylcyclohexane,
3,3-dimethyl-1-propene, 3-methyl-1-diisobutylene,
4-methyl-1-pentene;
[0046] acrylonitrile; vinyl esters, such as vinyl acetate; styrene,
substituted styrenes having one alkyl substituent in the side
chain, e.g. .alpha.-methylstyrene and .alpha.-ethylstyrene,
substituted styrenes having one alkyl substituent on the ring, e.g.
vinyltoluene and p-methylstyrene, halogenated styrenes, such as
monochlorostyrenes, dichlorostyrenes, tribromostyrenes, and
tetrabromostyrenes; heterocyclic vinyl compounds, such as
2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine,
3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine,
vinylpyrimidine, vinylpiperidine, 9-vinylcarbazole,
3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole,
2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone,
N-vinylpyrrolidine, 3-vinylpyrrolidine, N-vinylcaprolactam,
N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene,
vinylthiolane, vinylthiazoles, and hydrogenated vinylthiazoles,
vinyloxazoles and hydrogenated vinyloxazoles;
[0047] vinyl and isoprenyl ethers;
[0048] maleic acid derivatives, such as maleic anhydride,
methylmaleic anhydride, maleimide, methylmaleimide; and dienes,
such as divinylbenzene.
[0049] The polymerization is generally initiated by known
free-radical initiators. Examples of preferred initiators are the
azo initiators well known to persons skilled in the art, e.g. AIBN
and 1,1-azobis(cyclohexanecarbonitrile), and also peroxy compounds,
such as methyl ethyl ketone peroxide, acetylacetone peroxide,
dilauryl peroxide, tert-butyl per-2-ethylhexanoate, ketone
peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide,
diberizoyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxy
isopropyl carbonate,
2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-butylperoxy
2-ethylhexanoate, tert-butylperoxy 3,5,5-trimethylhexanoate,
dicumyl peroxide, 1,1-bis(tert-butylperoxy)cyclohexane,
1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, cumyl
hydroperoxide, tert-butyl hydroperoxide,
bis(4-tert-butylcyclohexyl) peroxydicarbonate, mixtures of two or
more of the abovementioned compounds with one another, and also
mixtures of the abovementioned compounds with compounds not
mentioned which can likewise form free radicals.
[0050] The amount often used of these compounds is from 0.1 to 10%
by weight, preferably from 0.5 to 3% by weight, based on the total
weight of the monomers.
[0051] Preferred poly(meth)acrylates are obtainable via
polymerization of mixtures which comprise at least 20% by weight,
in particular at least 60% by weight and particularly preferably at
least 80% by weight, of methyl methacrylate, based in each case on
the total weight of the monomers to be polymerized.
[0052] Use may be made here of various poly(meth)acrylates which
differ, for example, in molecular weight or in monomer
formulation.
[0053] The molding compositions may moreover comprise further
polymers in order to modify properties. Among these are, inter
alia, polyacrylonitriles, polystyrenes, polyethers, polyesters,
polycarbonates and polyvinyl chlorides. These polymers may be used
individually or in the form of a mixture, and it is also possible
here to add, to the molding compositions, copolymers which are
derivable from the abovementioned polymers. Among these are, in
particular, styrene-acrylonitrile polymers (SANs), the amount of
which added to the molding compositions is preferably up to 45% by
weight.
[0054] Particularly preferred styrene-acrylonitrile polymers may be
obtained via polymerization of mixtures composed of
[0055] from 70 to 92% by weight of styrene
[0056] from 8 to 30% by weight of acrylonitrile
[0057] from 0 to 22% by weight of further comonomers, based in each
case on the total weight of the monomers to be polymerized.
[0058] In particular embodiments, the proportion of the
poly(meth)acrylates is at least 20% by weight, preferably at least
60% by weight and particularly preferably at least 80% by
weight.
[0059] Particularly preferred molding compositions of type are
available commercially with the trade mark PLEXIGLAS.RTM. from Rohm
GmbH & Co. KG.
[0060] The weight-average molecular weight Mw of the homo- and/or
copolymers to be used according to the invention as matrix polymers
can vary widely, the molecular weight usually being matched to the
intended use and the method of processing of the molding
composition.
[0061] However, it is generally in the range from 20 000 to 1 000
000 g/mol, preferably from 50 000 to 500 000 g/mol and particularly
preferably from 80 000 to 300 000 g/mol, with no intended resultant
restriction.
[0062] The following substances were use as colorants: [0063]
Cromophtal Brown 5R, Ciba Specialty Chemicals [0064] Sandoplast Red
Violet R, Clariant [0065] Thermoplast Blue 684, BASF [0066]
Ultramarine Blue 31, Nubiola [0067] Bayferrox 180 M, Bayer [0068]
Bayferrox 645 T, Bayer [0069] Microlith Green GA, Ciba speciality
Chemicals [0070] Pigment black FW1, Degussa [0071] PK 24-10204,
Ferro [0072] PK 10456, Ferro [0073] Titanium dioxide CL 2220,
Kronos
Coloring of Molding Compositions
[0074] Colorants and molding compositions were homogenized by
roll-milling. The formulations for the individual examples have
been documented in Table 2. A Plexiglas.RTM. Plexiglas GS White 003
sheet (40 mm*21 mm) of thickness 3 mm was also used (see testing of
molding compositions). 1.5% of titanium dioxide C1 2220 is present
as colorant, IR-reflective pigment in the cast sheet composed of
PMMA.
[0075] PLEXIGLAS.RTM. 7N provides the residual amounts to give 100%
by weight.
TABLE-US-00002 TABLE 2 Formulations for Examples and Comparative
Examples Comp. Comp. Comp. Comp. Inv. Inv. Inv. Inv. Formulation
Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Chromophtal Brown
5R 0.90% Sandoplast Red Violet R 0.17% Thermoplast Blue 684 0.10%
Ultramarine Blue 31 0.65% Bayferrox 180 M 0.33% Bayferrox 645 T
0.18% Microlith Green GA 0.10% Pigment black FW1 1.00% Thermoplast
Black X70 0.60% Printex 104 V 0.09% PK 24-10204 1% 0.80% 9.60% PK
10456 1% Percentages in Table 1 are weight percentages, with
ingredients that are present in each individual composition having
weight percentages associated with the ingredients. The total
weight percentage of each composition is 100 wt. %, with the
remaining ingredient, Plexiglas .RTM. 7N, being present in an
amount such that the total weight percentages of all ingredients
add up to 100 wt. %.
Testing of Molding Compositions
[0076] A press was used to produce pressed plaques of thickness 0.5
mm from the colored molding compositions. The corresponding test
specimens were tested by the following methods: [0077] Heating
behavior: The specimen of diameter 50 mm and thickness 0.5 mm was
placed on a Rohacell.RTM. cube of edge length 50 mm. A thermocouple
of diameter of 0.5 mm was fixed under the centre of the specimen
with Tesa.RTM. film. A Plexiglas.RTM. GS White 003 sheet (40 mm*21
mm) had been impressed into the Rohacell.RTM.. The specimen with
thermocouple was secured onto this using double-sided-adhesive
Tesa.RTM. Fotostrip. The specimen was irradiated using a 60 W
incandescent lamp regulated with 220 V (AC voltage stabilizer).
Vertical distance between lower edge of glass bulb and specimen 50
mm. The temperature was read off after 20 minutes of irradiation.
Heating was measured by a method based on the standard ASTM
D4803-97. [0078] Light reflectance: Spectra measured on Perkin
Elmer Lambda 19. For this, the specimens were measured with and
sometimes without the Plexiglas GS White 003 sheet of thickness 3
mm.
[0079] The results for heating behavior of the test specimens can
be seen in Table 3.
TABLE-US-00003 TABLE 3 Heating behavior of Examples and Comparative
Examples Temperature after irradiation. Measurement using NiCr--Ni
thermocouple of diameter 0.5 mm with Testo 950 indicator L* value
a* value b* value D65/10; D65/10; D65/10; D65/10; D65/10; D65/10;
reflection; reflection; reflection; reflection; reflection;
reflection; heating; heating; heating; heating; heating; heating;
CieLab CieLab CieLab SPECIMEN CieLab CieLab CieLab [.degree. C./20
min] [.degree. C.] [.degree. C.] Comparison 1 (brown, 30.1 3.3 4.1
31.0 55.0 24.0 organic, IR-transparent) Comparison 2 (brown, 28.2
3.4 1.9 35.1 57.3 22.2 inorganic, IR-absorbent) Inventive example 1
28.3 4.5 2.2 29.4 53.3 23.9 (brown) Inventive example 2 27.2 3.9
1.8 32.3 56.0 23.7 (brown) Inventive example 3 27.7 4.0 1.9 31.7
55.6 23.9 (brown) Comparison 3 (black, 24.3 0.0 -0.8 43.8 67.7 23.9
inorganic, IR-absorbent) Comparison 4 (black, 24.0 -0.1 -0.9 42.8
66.8 24.0 inorganic, IR-absorbent) Example 4 (black) 26.1 1.3 0.6
37.4 61.4 24.0
[0080] The reflectance spectra can be seen in Table 3 (brown
colours with Plexiglas GS White 003 sheet of thickness 3 mm), Table
4 (black colours with Plexiglas GS White 003 sheet of thickness 3
mm), and Table 5 (brown colours without Plexiglas GS White 003
sheet of thickness 3 mm).
[0081] The examples clearly reveal the improvements achieved via
the invention described here: [0082] Table 2 shows that the heating
rate for the inventive brown pressed plaques (inventive Examples 1,
2, 3) is better than comparison 2 (brown pressed plaques produced
using an inorganically IR-absorbent colorant) and comparable with
comparison 1 (colorant used here being IR-transparent--IR
reflection taking place at the white Plexiglas GS sheet). From the
inventive black pressed plaques (inventive Example 4), it can also
be seen that the heating rate here is clearly better (lower) than
for comparisons 3 and 4. [0083] Table 3 and 4 clearly show that,
based on the respective shade, the inventive pressed plaques
clearly reflect IR light (wavelength >700 mm) better than the
comparisons. Comparison 1 is an exception here--however, the
reflection here takes place at the white Plexiglas.RTM. GS sheet.
[0084] Table 5 clearly shows that even without the underlying
Plexiglas.RTM. GS sheet, the inventive brown pressed plaques
clearly reflect the IR light better than the comparisons.
* * * * *