U.S. patent application number 13/809640 was filed with the patent office on 2013-05-16 for high temperature exterior building products.
This patent application is currently assigned to LUBRIZOL ADVANCED MATERIALS, INC.. The applicant listed for this patent is Andrew R. Bourgeois, Robert E. Detterman. Invention is credited to Andrew R. Bourgeois, Robert E. Detterman.
Application Number | 20130122269 13/809640 |
Document ID | / |
Family ID | 44504182 |
Filed Date | 2013-05-16 |
United States Patent
Application |
20130122269 |
Kind Code |
A1 |
Bourgeois; Andrew R. ; et
al. |
May 16, 2013 |
High Temperature Exterior Building Products
Abstract
An article suitable for outdoor construction applications is
provided. The article includes an inner layer having a CPVC
composition and an outer layer having a CPVC composition. An
intermediate layer is sandwiched between the inner and outer
layers. The intermediate layer is a PVC composition.
Inventors: |
Bourgeois; Andrew R.;
(Brusly, LA) ; Detterman; Robert E.; (Medina,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bourgeois; Andrew R.
Detterman; Robert E. |
Brusly
Medina |
LA
OH |
US
US |
|
|
Assignee: |
LUBRIZOL ADVANCED MATERIALS,
INC.
Cleveland
OH
|
Family ID: |
44504182 |
Appl. No.: |
13/809640 |
Filed: |
July 12, 2011 |
PCT Filed: |
July 12, 2011 |
PCT NO: |
PCT/US2011/043661 |
371 Date: |
January 11, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61363465 |
Jul 12, 2010 |
|
|
|
Current U.S.
Class: |
428/215 ;
428/220; 428/319.7; 428/335; 428/421; 428/518 |
Current CPC
Class: |
B32B 2264/102 20130101;
B32B 2307/734 20130101; B32B 27/08 20130101; B32B 2307/712
20130101; B32B 5/18 20130101; B32B 2307/732 20130101; B32B 2264/10
20130101; B32B 2264/104 20130101; B32B 2419/00 20130101; Y10T
428/24967 20150115; E04F 13/0875 20130101; Y10T 428/264 20150115;
B32B 27/30 20130101; B32B 7/12 20130101; B32B 27/304 20130101; B32B
2266/0228 20130101; B32B 27/065 20130101; E04F 13/18 20130101; Y10T
428/3192 20150401; Y10T 428/3154 20150401; E04B 1/76 20130101; Y10T
428/249992 20150401; B32B 2307/72 20130101; B32B 27/20
20130101 |
Class at
Publication: |
428/215 ;
428/518; 428/319.7; 428/220; 428/421; 428/335 |
International
Class: |
E04B 1/76 20060101
E04B001/76 |
Claims
1. An article for construction applications comprising: a. an inner
layer comprising a CPVC composition; b. an outer layer comprising a
CPVC composition; and c. an intermediate layer sandwich between
said inner and outer layers, the intermediate layer comprising a
PVC composition.
2. The article of claim 1 further including a cap layer adhered to
the CPVC composition outer layer.
3. The article of claim 1 wherein the CPVC composition is at least
16 weight percent of the material of the article.
4. The article of claim 1 wherein said article includes a siding
panel.
5. The article of claim 1 wherein the CPVC composition has a heat
distortion temperature greater than 180.degree. F.
6. The article of claim 1 and further including a layer of
insulation foam adhered to the inner layer.
7. The article of claim 1 wherein at least one of the inner layer
and the outer layer has a thickness in the range of 2 to 19
mils.
8. The article of claim 7 wherein at least one of the inner layer
and the outer layer has a thickness in the range of 4 to 6
mils.
9. The article of claim 1 wherein the outer layer is a dark color
having an L value less than 50.
10. The article of claim 1 wherein the intermediate layer comprises
more than an insignificant amount of talc.
11. The article of claim 1 wherein the article having a CPVC
material content of 16 weight percent is deflected less than 5 mm
in Oven Sag Tests performed at 180.degree. F., 200.degree. F., and
230.degree. F.
12. The article of claim 1 wherein the article has a thickness of
from about 30 to about 50 mils.
13. The article of claim 12 wherein the article has a thickness of
from about 40 to about 48 mils.
14. The article of claim 2 where said cap layer is selected from
the group consisting of PVC, ASA, and fluoropolymer.
15. The article of claim 14 wherein said cap layer comprises a
fluoropolymer and has a thickness of from about 1 to about 2
mils.
16. The article of claim 1 wherein at least one of the inner layer
and the outer layer has a thickness in the range of from about 3 to
about 10 mils.
17. An article for construction applications comprising: a. an
inner layer comprising a high heat plastic composition; b. an outer
layer comprising a high heat plastic composition; and c. an
intermediate layer sandwich between said inner and outer layers,
the intermediate layer comprising a PVC composition.
18. The article of claim 17 in which at least one of the high heat
plastic compositions of a. or b. is a CPVC composition.
Description
TECHNICAL FIELD
[0001] The invention relates generally to siding, trim, decking,
fencing, roofing and other construction materials suitable for
higher temperature applications than standard PVC applications.
BACKGROUND
[0002] Polyvinyl chloride (PVC), also known as vinyl, has become
common in use as house siding, trim, decking and fencing. Because
of its low cost and ease of installation, PVC has gained wide
acceptance as a construction material. However, because of its
inability to withstand higher temperatures, PVC siding is used
mainly in cooler climates, such as the northern states of the
U.S.A. The use of PVC is sometimes avoided in warmer climates, such
as exist in the U.S. states of Florida and Arizona.
[0003] Recently, another problem has been found with PVC siding in
cooler climates. More residential structures are being built with
irregular exterior walls and closer to adjacent structures. This
has led to structures having a problem with reflective heat causing
the siding and trim to distort from the heat. The excess heat is
generated as a result of the sun's rays shining on a window and
being reflected to an adjacent wall of the same structure or a
neighboring structure.
[0004] Also, PVC is normally sold in white or light pastel colors
for construction applications. Dark colors, such as red, black,
brown and the like absorb more energy from the sun and cause the
temperature of the material to exceed the useable temperature of
PVC. Consumers and builders would like the option of using dark
colors for some structures.
[0005] Construction materials comprising PVC may benefit from
improvements.
ASPECTS OF EXEMPLARY EMBODIMENTS
[0006] An exemplary embodiment includes an article suitable for
outdoor construction applications that comprises an inner layer
comprising a chlorinated polyvinyl chloride (CPVC) composition; an
outer layer comprising a CPVC composition; and an intermediate
layer sandwich between the inner and outer layers. An additional
weather resistant cap layer may be included over the article outer
layer. The intermediate layer comprises a PVC, or blended PVC
composition. Other aspects of exemplary embodiments will be made
apparent in the following Detailed Description of Exemplary
Embodiments and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing summary, as well as the following detailed
description of exemplary embodiments, will be better understood
when read in conjunction with the appended drawings. For the
purpose of illustration, there is shown in the drawings certain
exemplary embodiments. It should be understood, however, that the
invention is not limited to the precise arrangements and
instrumentalities shown in the drawings or described herein.
[0008] FIG. 1 is a perspective view end portions of a siding
substrate according to a first embodiment;
[0009] FIG. 2 is a sectional view of the siding substrate without
the insulating material taken along line 2-2 of FIG. 1;
[0010] FIG. 3 is a sectional view similar to that of FIG. 2 of a
siding substrate according to a second embodiment;
[0011] FIG. 4 a sectional view similar to that of FIG. 2 of a
siding substrate according to a third embodiment; and
[0012] FIG. 5A-C are graphs showing the results of an Oven Sag Test
for a sample of the siding substrate of the first embodiment and
samples of other sidings.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0013] The articles of some exemplary embodiments are comprised of
rigid thermoplastic materials with high heat distortion
temperatures. Chlorinated polyvinyl chloride (CPVC) compositions
may be used to make the articles by using an extrusion process.
[0014] A first exemplary embodiment comprises siding 10 used for
buildings such as residential buildings and is depicted in FIGS. 1
and 2. As best seen in FIG. 2, the siding 10 comprises an inner
layer 12 comprising a CPVC composition; an outer layer 14
comprising a CPVC composition; and an intermediate layer 16
sandwiched between the inner and outer layers 12, 14. The
intermediate layer 16 of the exemplary embodiment comprises a
polyvinyl chloride (PVC) composition. The exemplary CPVC material
of the siding ranges from 9 to 75 wt. %, preferably 12 to 48 wt. %,
and most preferred from 16 to 24 wt. % of the total weight of the
CPVC inner and outer layers and the PVC intermediate layer. In one
embodiment, the material of siding 10 of this embodiment contains
about 16 wt. % CPVC and in another embodiment the material of
siding 10 contains about 24 wt. % CPVC. The exemplary siding 10
also includes slots 18 formed at a hem 20 of the siding 10 that are
used for hanging the siding. The siding may include an optional
strip 28 for interlocking with a subsequent piece of siding (such
as 10 is shown). The siding may also have an insulating member 22
such as foam adhered to the inner layer 12 by adhesive material
between the insulating member 22 and the innermost layer 12, and/or
a weather resistant cap layer 15 on top of the outer layer 14.
[0015] The CPVC compositions contain CPVC polymer (resin) along
with various additives, which are described below. The CPVC resin
constitutes at least 50% by weight of the CPVC composition as these
are rigid compositions. CPVC compositions are available
commercially worldwide from a variety of sources, including
Lubrizol Advanced Materials, Inc. of Cleveland, Ohio U.S.A.
[0016] CPVC for use in exemplary embodiments may be prepared by the
post-chlorination of suspension or mass polymerized PVC. Suspension
polymerization techniques may be of the type described in the
Encyclopedia of PVC, pp. 76-85, published by Marcel Decker, Inc.
(1976), for example.
[0017] CPVC is obtained by chlorinating homopolymers or copolymers
containing less than 50% by weight of one or more copolymerizable
comonomers. Suitable comonomers for vinyl chloride include acrylic
and methacrylic acids; esters of acrylic and methacrylic acid,
wherein the ester portion has from 1 to 12 carbon atoms, for
example, methyl-, ethyl-, butyl-, ethylhexyl acrylates and the
like; methyl-, ethyl-, butyl methacrylates and the like;
hydroxyalkyl esters of acrylic and methacrylic acid, for example,
hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxyethyl
methacrylate and the like; glycidyl esters of acrylic and
methacrylic acid, for example, glycidyl acrylate, glycidyl
methacrylate and the like; alpha, beta-unsaturated dicarboxylic
acids and their anhydrides, for example, maleic acid, fumaric acid,
itaconic acid and acid anhydrides of these, and the like;
acrylamide and methacrylamide; acrylonitrile and methacrylonitrile;
maleimides, for example, N-cyclohexyl maleimide; olefin, for
example, ethylene, propylene, isobutylene, hexene, and the like;
vinylidene halide, for example, vinylidene chloride; vinyl ester,
for example vinyl acetate; vinyl ether, for example methyl vinyl
ether, allyl glycidyl ether, n-butyl vinyl ether and the like;
crosslinking monomers, for example, diallyl phthalate, ethylene
glycol dimethacrylate, methylene bis-acrylamide, tracrylyl
triazine, divinyl ether, allyl silanes and the like; and including
mixtures of any of the above comonomers. Comonomers as well as
crosslinking comonomers are preferably absent. That is, preferred
are homopolymers and uncrosslinked CPVC polymers.
[0018] The molecular weight as measured by I.V. of precursor
polyvinyl chloride for the CPVC polymer will range from about 0.4
to about 1.6, preferably 0.5 to 1.2 and most preferably from about
0.7 to 1.0 I.V. The inherent viscosity is a representative measure
of the molecular weight of a polymer and is obtained in accordance
with ASTM procedure No. D-1243-66. The choice of molecular weight
is made by considering the shape and intricacy of the profile, the
processing conditions and the physical property balance desired. If
the molecular weight is too low, there may be insufficient melt
strength and the dimensional stability of the hot extrudate will
suffer, and if the molecular weight is too high, the compound may
not be processable under the desired conditions. Acceptable results
are obtained under a variety of conditions and cross-sectional
shapes using an I.V. of the PVC precursor of about 0.85 to
0.95.
[0019] Chlorination of PVC can be carried out to obtain a
chlorinated base polymer having higher than 57 percent by weight
chlorine up to about 74 percent by weight based upon the total
weight of the polymer. However, in practice, the use of a major
amount of CPVC having a chlorine content of greater than 65% weight
and up to 74% is preferred, and more preferably from 66% to about
70% chlorine.
[0020] The preferred method of post-chlorination is by the aqueous
suspension chlorination method. There are considerations relative
to this method wherein the preferred mode of chlorination employs a
relatively concentrated aqueous suspension of the precursor PVC.
The most preferred method results in a CPVC resin having a density
which does not deviate more than about 20 percent from the mean
density, and a surface area which does not deviate more than 30
percent from the mean surface area is more desirable. A
concentration of about 15 to about 35 weight percent of solids in
the suspension is preferred. Generally, a concentration of the
suspension higher than the specified range results in less uniform
chlorinated product, while concentrations below 15 percent yield
uniform product, but are not as economical. By "aqueous suspension"
of PVC base polymer, we refer to a slurry-like mixture of base
polymer macrogranules suspended in water. This process is
particularly directed to a batch process.
[0021] It is desired that oxygen be removed from the aqueous
suspension before chlorination is initiated. This may be assisted
with agitation. Heating as may be required is preferably done after
Cl.sub.2 is sparged into suspension from a liquid Cl.sub.2 cylinder
until the pressure in the reactor reaches about 25 psig, at which
point the suspension is saturated with Cl.sub.2. It is preferred
that this pressure be somewhat higher, that is, in the range from
about 35 psig to about 100 psig, to get the optimum results, though
a pressure as low as 10 psig and higher than 100 psig may be
employed. The amount of Cl.sub.2 charged to the reactor is
determined by weight loss in the Cl.sub.2 cylinder. The reactor is
preferably brought up to a "soak" temperature in the range from
about 60.degree. C. to about 75.degree. C. at which soak
temperature the suspension is maintained under agitation for a soak
period in the range from about 1 minute to about 45 minutes.
Excessive pressure adversely affects the porosity of the
macrogranules to the detriment of the stability of the chlorinated
product.
[0022] It is desirable to complete the chlorination reaction under
photo-illumination, preferably with ultraviolet light, or the
desired conversion of base polymer to chlorinated base polymer
product may not occur. Chlorination proceeds at a rate which
depends upon the pressure and temperature within the reactor,
higher rates being favored at higher temperature and pressure. It
is most preferred to adjust the soak temperature, the mass of
resin, and the level of photo-illumination so that the temperature
is "ramped" by the heat of reaction until it levels off at a
finishing temperature of about 100.degree. C. After chlorination
has proceeded to the desired degree, the suspension is preferably
not cooled but dumped to be centrifuged and the chlorinated polymer
freed from the aqueous phase, after which HCl is removed from the
product, preferably by neutralizing with an aqueous solution of an
alkali metal hydroxide. The product is then washed with water to
free the chlorinated polymer of residual alkali, and dried, except
that the temperatures at which the operations are carried out may
be in the range from about 60.degree. C. to about 100.degree. C.,
which may be somewhat higher than conventionally used.
[0023] The rigid CPVC compositions contain various other
ingredients, in addition to the CPVC polymer, to enhance processing
and performance of the articles. Ingredients such as heat
stabilizers, impact modifiers, processing lubricants, antioxidants,
antistats, processing aids, fillers, fibers and coloring pigments
can be used in the CPVC compositions of exemplary embodiments. A
desirable additive in some embodiments is chlorinated
polyethylene.
[0024] The chlorinated polyethylene (CPE), when used in the CPVC
compositions of the multi-layer article, has a specific gravity of
from about 1.13 to 1.4, preferably about 1.16, a residual
crystallinity of from about 0 to about 25%, preferably 0 to 10%,
and a chlorine content from about 25% to about 45%, preferably 35%
to 44%. The chlorination can be either homogeneous or heterogeneous
preferably to a small extent. Surface appearance of extrudates
depended on CPE molecular weight and polydispersity as measured by
gel permeation chromatography and on the extrusion conditions used.
Chlorination methods for CPE include aqueous suspension, solution,
or gas phase methods, with the preferred method by way of
suspension chlorination. CPE is commercially available from
numerous sources such as Dow Chemical Inc. When CPE is used, the
amount of CPE in the CPVC compositions present ranges from about 10
to about 30 parts per 100 parts by weight (phr), preferably from
about 12 to about to 25 phr, still more preferred are levels from
15 to 25 phr of CPVC resin. The particular combination of CPVC and
CPE in exemplary aspects will be described below.
[0025] The core/shell type impact modifiers can be present in the
CPVC compositions. These include acrylonitrile butadiene styrene
terpolymers (ABS), methacrylate, acrylonitrile, butadiene, styrene
(MABS) polymers and methacrylate butadiene styrene polymer (MBS).
Other impact modifiers are disclosed in Plastics Compounding,
November/December, 1983: "Update: Impact Modifiers for Rigid PVC,"
by Mary C. McMurrer. Various commercial MBS grades include
Paraloid.RTM. KM-653, BTA-733 from Rohm and Haas, or Kanegafuchi
Inc. B-56 and B-22; Commercial polyacrylate impact modifiers
include KM.RTM.-323B, and KM.RTM.-330, from Rohm and Haas, Inc.;
ABS grades are commercially available from GE Plastics, Inc, for
example, Blendex.RTM. 338.
[0026] Thermal stabilizers are employed in the compounds herein and
can be selected from various organic compounds. Suitable tin
stabilizers include tin salts of monocarboxylic acids such as
stannous maleate. Examples of tin stabilizers include without
limitation: alkylstannoic acids, bis(dialkyltin alkyl
carboxylate)maleates, dialkyltin bis(alkylmaleates), dialkyltin
dicrotonates, dialkyltin diolates, dialkyltin laurates, dialkyltin
oxides, dialkyltin stearates, alkylchlorotin bis(alkylmercaptides),
alkylchlorotin bis (alkylmercaptopropionates), alkylthiostannoic
acids, alkyltin tris(alkylmercaptides), alkyltin
tris(alkylmercaptoacetates), alkyltin
tris(alkylmercaptopropionates), bis
[dialkyl(alkoxycarbonylmethylenethio)tin] sulfides, butyltin oxide
sulfides, dialkyltin bis(alkylmercaptides), dialkyltin
bis(alkylmercaptoacetates), dialkyltin
bis(alkylmercaptopropionates), dialkyltin .beta.-mercaptoacetates,
dialkyltin .beta.-mercaptoacetates, dialkyltin
.beta.-mercaptopropionates, dialkyltin sulfides, dibutyltin
bis(i-octyl maleate), dibutyltin bis(i-octyl thioglycolate),
dibutyltin bisthiododecane, dibutyltin .beta.-mercaptopropionate,
dimethyltin bis(i-octyl thioglycolate), dioctyltin laurate,
methyltin tris(i-octyl thioglycolate). Examples of a commercially
available tin stabilizer are Mark 292 and Mark 1900 stabilizers
from Chemtura Chemical and Thermolite 31 stabilizer from Arkema.
Tin compounds are generally used at from 1 to 5 phr (parts by
weight per 100 parts by weight of CPVC resin), preferably about 2.0
to 4.0 phr.
[0027] Secondary stabilizers may be included, if desired, but are
not necessary. Examples of secondary stabilizers include metal salt
of phosphoric acid, polyols, epoxidized oils, and acid acceptors
which are not detrimental to the base CPVC resin used. The
secondary stabilizers can be used by themselves or in combinations
as desired. Specific examples of metal salts of phosphoric acid
include water-soluble, alkali metal phosphate salts, disodium
hydrogen phosphate, orthophosphates such as mono-, di-, and
tri-orthophosphates of said alkali metals, alkali metal
polyphosphates, -tetrapolyphosphates and -metaphosphates and the
like. Polyols such as sugar alcohols, and epoxides such as
epoxidized soya oil can be used. Examples of possible acid
acceptors include potassium citrate, aluminum magnesium hydroxyl
carbonate hydrate, magnesium aluminum silicates and alkali metal
alumino silicates. Examples of magnesium aluminum silicates are
molecular sieves such as, for example, Molsiv.RTM. Adsorbent Type
4A from UOP. Examples of alkali metal alumino silicates are
zeolites such as CBV 10A Zeolite Na-Mordenite by Synthetic Products
Co. The most preferred secondary stabilizer is disodium hydrogen
phosphate (DSP) and is used by treating the CPVC resin. Typical
levels of secondary stabilizers can range from about 0.1 wt. parts
to about 7.0 wt. parts per 100 wt. parts CPVC polymer (phr).
[0028] In addition, commercially available antioxidants are used
such as phenolics, BHT, BHA, various hindered phenols and various
inhibitors like substituted benzophenones.
[0029] Other auxiliary components are contemplated. Antistats may
be used and are commercially available under the Glycolube.RTM.
trademark of Lonza Corp. Exemplary lubricants are the various
hydrocarbons, such as paraffins, paraffin oils, low molecular
weight polyethylene, oxidized polyethylenes, fatty acids and their
salts such as stearic acid and calcium stearate, fatty alcohols
such as cetyl, stearyl, or octadecyl alcohol; metal soaps such as
calcium or zinc salts of oleic acid; fatty amides of organic acids
such as stearamide, ethylene-bis-stearamide; preferred fatty esters
and partial esters such as butyl stearate, polyol esters such as
glycerol monostearate, hexaglycerol distearate; and fatty ester
waxes such as stearyl esters. The most preferred lubricant is
oxidized polyethylene. Henkel Co. produces a variety of preferred
fatty ester formulations under the Loxiol.RTM. mark. Combinations
of internal and external lubricants may also be used. Lubrication
of the CPVC polymer compounds may involve several lubricants
combined in variations. The total amount of lubricant may vary in
some embodiments generally from about 2 to 10 phr, preferably from
2 to about 6 phr.
[0030] Adjustment of melt viscosity can be achieved as well as
increasing melt strength by optionally employing commercial acrylic
process aids such as those from Rohm and Haas under the
Paraloid.RTM. Trademark, for example, Paraloid.RTM. K-120ND,
K-120N, and K-175.
[0031] Exemplary fillers for both the CPVC layer and PVC layer are
optional and include clay, wollastonite, mica, barytes, calcium
carbonate, talc and silica including precipitated silicas, silica
gels, metallic silicates, pyrogenic or fumed silicas and the like.
These have the general formulae: SiO.sub.2,
M.sub.n(SiO.sub.3).sub.x. The values of n and x can vary with the
oxidation state of the metal associated with the SiO.sub.3 ion. The
values n and x are usually integers from about 1 to about 4.
[0032] Preferred pigments are the various titanium dioxides
(TiO.sub.2) and carbon blacks which are commercially available.
Preferred TiO.sub.2 types are coated or uncoated, rutile titanium
dioxide powder. An exemplary commercial grade is Ti-Pure.RTM. R-100
from E.I. DuPont De Nemours and Co. Inc. (DuPont). If used,
pigments such as TiO.sub.2 are present in an amount ranging from 1
to 25 phr, more typically 3 to 15 phr, and most typically from 3 to
about 8 phr. Optional coloring pigments can be used.
[0033] Coloring pigments are used to impart the desired color of
the CPVC composition. TiO.sub.2 is the normal pigment to give a
white color and carbon black is used to give a black color. Blends
of color pigments are often used to achieve a color that is other
than black or white. For example, a blend of TiO.sub.2 and carbon
black is used to obtain a grey color. Various other color pigments
such as red, blue, green, yellow and brown are commercially
available from companies such as Ferro and Clariant. The color
pigments can be added to the composition as dry powders, liquid
dispersions or as a concentrate in the form of a color
masterbatch.
[0034] The CPVC compositions are prepared by compounding the
ingredients together. The method of compounding preferably used is
high intensity methods to uniformly mix and fuse the components
into a homogeneous compound such as with a Banbury/mill, followed
by sheeting, slitting or extrusion into pellets, or cubes. The
differences in process handling of CPVC compared with polyvinyl
chloride-based compounds relate mainly to the temperature and
viscosity differences and care must be taken to avoid too much work
and shear burning. In the preparation of compounds, the components
can be combined and mixed with a Banbury and milled on a heated
roll mill. The fused compound can be extruded and chopped into
cubes. Alternatively, the components can be combined in a
compounding twin screw extruder. The compounds are extruded into
final form at conventional stock temperatures from about
175.degree. C. to about 225.degree. C. The components of the CPVC
composition can also be blended together in powder form and the
blended powder fed to an extruder.
[0035] The articles of exemplary embodiments can be of any color,
but are particularly useful in dark colors. Certain PVC articles,
such as house siding, are often only available in white and light
pastel colors. This is because the dark colors, such as black, red,
dark brown and the like absorb more heat from the sun and distort
PVC articles. PVC articles can be used in cooler climates in light
colors (white or pastel), but are not generally used in warmer
climates, such as southern and southwest U.S. climates, nor is PVC
commonly used for house siding or the like in dark colors, even in
cooler climates. Typically, only the outer layer of CPVC
composition would need to be colored as the inner layer is hidden
in use and the intermediate layer of PVC is hidden in siding
applications. However, for efficiencies in production, it may be
advantageous to use the same CPVC composition for both the inner
and outer layers.
[0036] It is customary to define color as a L value. L value is a
scale of from 0 to 100. The color black would represent an L value
of 0 and the color white would represent an L value of 100. When
the term "dark colors" is used herein, it means the color has a L
value of less than about 50, preferably less than about 40, and
more preferably less than about 30.
[0037] The CPVC compositions of exemplary embodiments preferably
have a high heat distortion temperature (HDT) as measured by ASTM
D-648. The HDT of exemplary compositions is greater than about
180.degree. F. (about 82.2.degree. C.), greater than 190.degree. F.
(about 87.8.degree. C.), desirably greater than 205.degree. F.
(about 96.1.degree. C.), preferably greater than about 210.degree.
F. (about 98.9.degree. C.), and more preferably greater than about
215.degree. F. (about 101.7.degree. C.). HDT of the composition can
be varied by the chlorine content of the CPVC polymer. The higher
the chlorine content, the higher the HDT. HDT of the CPVC
composition can also be affected by the various compounding
ingredients. Liquid or low molecular weight ingredients such as
plasticizers, process aids and lubricants can lower the HDT and
thus are used in certain exemplary embodiments in small amounts.
The particular HDT of the composition used to make the articles
will generally be selected based on the service temperature the
article will experience in use. For example, an article of a dark
color will commonly benefit from a higher HDT than a light color
article used in the same climate and application. Articles, such as
siding and trim for siding commonly benefit from a higher HDT when
they are subjected to reflective heat as can occur from windows in
adjacent walls or adjacent structures.
[0038] To form the CPVC composition into various articles of
exemplary embodiments, the extrusion process may be used. The
extruder is fed with the composition in either powder, cube or
pellet form. The composition is melt processed and forced through a
die into the desired shape of the article. The extruder
characteristics applicable to melt processing of the CPVC compounds
include: Extruder drive/gearbox capable of generating high torque
at low rpm. Vacuum venting to remove volatile components, moisture
and entrapped air. A barrel L/D of at least 16/1 for twin screw;
generally at least 20/1 for single screw. Temperature controllers
able to control within +/-5.degree. F. or preferably +/-2.degree.
F. Accurately controllable powder metering screw for powder
compounds.
[0039] A ramped barrel temperature profile is advisable with a zone
nearest the hopper set at 180.degree. C. and the zone nearest the
die at about 195.degree. C. for 0.75 inch (about 19.05 mm) diameter
screw. There can be used calibrating blocks at the exit end to
assist in proper dimension sizing as the hot profile is cooled. Air
streams can be used to improve heat loss, and for more close
tolerances, vacuum water sizing devices can be used. The extent to
which one chooses to employ calibrator blocks and air or water
sizing will depend on dimension tolerances for the particular
profile shape, the intended output volume of any one profile
article and the number of different profiles made with a particular
production set.
[0040] The CPVC composition described above is the preferred
composition for making siding and siding trim components. For
articles which are thicker, other CPVC compositions may be used and
in some cases preferred. The CPVC composition used will vary
depending on the requirements of the end use application. In some
embodiments, the CPVC composition may be a CPVC based blend with
other high heat plastics, such as styrenics. In alternate
embodiments, at least one of the inner and outer layers may
comprise a composition of a high heat plastic, such as, styrenics,
for example, styrene-acrylonitrile copolymers (SAN),
methyl-styrene-acrylonitrile copolymers (AMSAN), or blends thereof.
The term "high heat plastics" as used herein refers to materials
that can exceed 180.degree. F. in continuous operating
temperature.
[0041] When the exemplary article is a house siding or siding trim,
the CPVC composition for each of the outer layer and inner layer
may be extruded to a thickness of from about 2 to about 19 mils
(about 0.05 to about 0.48 mm), preferably 3 to 10 mils (about 0.08
to about 0.25 mm) and more preferably 4 to 6 mils (about 0.10 to
about 0.15 mm) The siding and trim thickness is typically about 30
to about 50 mils (about 0.76 to about 1.27 mm) and more typically
40 to 48 mils (about 1.02 to about 1.22 mm) The term "siding trim"
as used herein has the customary industry meaning and includes trim
pieces such as outside corners, inside corners, channels around
windows and doors, and the like, used in conjunction with the
installation of siding. The siding and trim of some embodiments can
be thinner than PVC siding because the exemplary embodiments are
able to withstand greater heat and are more resistant to
deformations. The siding and trim can be embossed to provide a wood
grain surface for aesthetic appeal. The siding and trim of some
embodiments may be applied horizontally or vertically on a
structure.
[0042] When articles of exemplary embodiments include decking and
fencing, the extrusion may be thicker than that for siding because
of the structural requirements. Decking and fencing will typically
have a thickness of greater than 0.05 (about 1.27 mm) and
preferably greater than 0.1 inch (about 2.54 mm) Decking and
fencing are typically extruded with a cross section in a
substantially rectangular shape and can have rounded corners to aid
in the extrusion process. The term "rectangular shape" as used
herein is intended to include rectangle shapes which have rounded
corners. The rectangular shape can be hollow inside to save weight
or can have reinforcing webs to add strength and rigidity. The
extruded decking or fencing boards can also be filled with foam to
add rigidity. Decking boards can also be embossed with a non-skid
surface to provide more traction when wet. Decking materials may
include the floor of the deck as well as supporting posts and
rails, which can all be made from the exemplary CPVC compositions.
Fencing may include the fence boards or rails as well as the posts.
The decking and fencing articles of exemplary embodiments eliminate
the need for painting or staining as well as the need to use
treated lumber and the environmental and health risks associated
with the use of pressure treated lumber.
[0043] As previously mentioned, exemplary embodiments including
siding and trim may have an insulating layer 22. The insulating
layer 22 may include a layer of polystyrene foam but could be other
insulating materials, such as polyurethane foam. The insulating
layer 22 is preferably bonded to the CPVC layer with a suitable
adhesive 24 as illustrated in FIG. 1. A suitable adhesive for
bonding CPVC to polystyrene foam is a moisture cured urethane, such
as manufactured by Ashland Chemical Company of Columbus, Ohio
U.S.A. and known as ISOGRIP.RTM. 3030D. Alternatively, heat and
pressure sensitive adhesives can be used as well as latex based
adhesives. Preferably, the adhesive remains flexible during use of
the article.
[0044] The use of an insulating layer 22, such as foam, gives the
siding and trim insulating properties to conserve energy. An
insulating layer may also be used to make the siding or trim more
rigid. Increased rigidity allows the CPVC layer to be thinner and
aids in the installation of the articles to a structure. The siding
and trim are attached to a structure by conventional means such as
nails, screws, staples, adhesives or other fasteners.
[0045] To produce exemplary articles having an insulating layer 22,
the CPVC composition may be extruded as described above. The
insulating layer is formed to the desired size. The adhesive 24 is
applied to the insulating layer or the CPVC extruded profile layer.
The adhesive can be applied by roll coating, stitching, extruding,
spraying or curtain coating. The adhesive can also be applied in
the form of beads which cover only a portion of the CPVC layer. The
extruded CPVC is applied to the insulating layer 22 with the
adhesive between the layers to form the article. The articles may
be made in conventional lengths, such as 10 or 20 feet (about 3.05
or 6.1 m), to facilitate storage and transport to a job site.
[0046] The intermediate layer 16 of PVC can be made from
commercially available PVC compositions, including recycled
material. The PVC compositions are available from several
manufacturers, such as ShinTech and PolyOne. Preferably, a PVC
composition used is one designed for siding applications. The PVC
compositions designed for siding applications use the same PVC
resin as described above for the PVC precursor resin used to make
the CPVC resin. Also, similar additives, such as heat stabilizers,
impact modifiers, flow aids, lubricants and the like, can be used
as described above for CPVC. The PVC compositions can be made the
same way as the CPVC compositions described above, except that PVC
has a slightly lower processing temperature, usually about
10-30.degree. F. The % of the CPVC layers in the composite siding
herein are expressed in weight percent. This is slightly different
from thickness percent, as CPVC compositions normally have a higher
specific gravity than PVC, usually about 10 to 20% higher. If the
PVC layer contains a large amount of heavy fillers, such as calcium
carbonate or talc, it may have a higher specific gravity than the
CPVC layers, as is well understood by those skilled in the art.
[0047] Embodiments that comprise siding 10 can be made in
conventional widths such as from 4 to 10 inches (about 10.16 cm to
about 25.4 cm) or can be made in thinner or wider widths. The
addition of an insulating layer to provide added rigidity may allow
the siding to be made wider than conventional siding, if desired.
Wider widths can reduce labor in the installation phase of
construction. Widths as wide as 12, 18, 24, 36 or 48 inches (30.48,
45.72, 60.96, 91.44, or 121.92 cm) can be made with the insulating
layer 22 capped with CPVC. Siding trim pieces may also be made in
standard widths, or wider or narrower in some embodiments.
[0048] The CPVC layer on the insulated siding and trim will
preferably be from about 2 to about 19 mils (about 0.05 to about
0.48 mm), preferably 3 to 10 mils (about 0.08 to about 0.25 mm) and
more preferably 4 to 6 mils (about 0.10 to about 0.15 mm) thick.
The insulating layer is preferably a thickness of from about 0.1 to
about 2.0 inches (about 0.254 to about 5.08 cm). PCT Patent
Application WO 99/22092 describes a PVC siding product with a foam
backing and U.S. Pat. No. 5,542,222 describes a corner post of PVC
with a foam backing. The CPVC siding and siding trim components of
this invention are made similar to those described in the two
disclosures above with the exception that the PVC layer is replaced
with two CPVC layers (inner and outer layers) and a PVC
intermediate layer. The outer CPVC layer or all three layers can be
in dark colors. U.S. Pat. No. 5,542,222 and PCT Patent Application
WO 99/22092 are hereby incorporated in their entirety in this
disclosure.
[0049] Cap layer(s) can also be applied to the CPVC outer layer to
increase weather resistance. One or more cap layers can be used.
For example, a thin cap layer of PVC can be applied to the CPVC
layer. In place of a PVC containing cap layer, a cap layer of ASA
(acrylonitrile-styrene-acrylate) can be used. The PVC or ASA cap
layer may be about 3 to 10 mils (about 0.08 to about 0.25 mm) thick
and can be co-extruded with the CPVC layer. Since the cap layer has
a lower HDT than the CPVC layer, the cap layer is preferably
thinner than the CPVC layer. In some embodiments, a further cap
layer of a composition containing a fluoropolymer can be applied to
the first cap layer or can be applied directly to the CPVC layer.
The fluoropolymer cap layer may be about 1 mil to about 2 mils
(about 0.03 to about 0.05mm) thick. The fluoropolymer cap layer can
be pre-prepared and laminated to the CPVC or first cap layer or can
be co-extruded directly onto the CPVC or first cap layer. The
fluoropolymer containing cap layer may also contain a substantial
amount of acrylic polymer in order to gain adhesion to the CPVC or
first cap layer. A fluoropolymer containing cap layer and the ASA
cap layer may have better weathering properties than the CPVC or
PVC layer.
[0050] FIG. 3 shows a second exemplary embodiment. Similar
reference numbers will be used for elements that are common with
the first embodiment. This siding 100 comprises an inner layer 12
comprising a CPVC composition; an outer layer 14 comprising a CPVC
composition; and an intermediate layer 160 sandwiched between the
inner and outer layers 12, 14. This intermediate layer 160
comprises a semi-rigid material such as fiber cement composition.
An adhesive layer (not shown) may be used between the intermediate
layer 160 and the inner layer 12 and between the intermediate layer
160 and the outer layer 14.
[0051] FIG. 4 shows a third exemplary embodiment. Similar reference
numbers will be used for elements that are common with the first
embodiment. This siding 200 comprises an inner layer 12 comprising
a CPVC composition; an outer layer 14 comprising a CPVC
composition; and an intermediate layer 260 sandwiched between the
inner and outer layers. The intermediate layer comprises a
semi-rigid material such as PVC foam or CPVC foam.
EXAMPLE
[0052] Tests were performed on composite plaques (representing
siding) of the exemplary embodiment and two other multi-layer
(comparative) composite products. To form the composite plaques,
three layer samples are put into a press cavity plate for thickness
control. The press is set at about 380.degree. F. (about
193.3.degree. C.) with 1000 psi (about 6.89 MPa) low pressure for 6
minutes. The pressure is raised to 54 tons and held for 3 minutes.
The obtained composite is then cooled under pressure. One of the
comparative composite plaque products comprised a layer of PVC with
only one layer of CPVC. The weight percentage of CPVC content in
this comparative product was 24%. The other comparative composite
plaque product comprised an inner layer comprising a PVC
composition; an outer layer comprising a PVC composition; and an
intermediate layer sandwich between the inner and outer layers. The
intermediate layer comprised a CPVC composition. The weight
percentage of CPVC content in this product was 60%. Samples of
0.125 inch (about 3.18 mm) thick for each plaque to be tested were
taken.
[0053] One test was done using composite plaques comparing the Oven
Sag at 180.degree. F. (about 82.2.degree. C.), 200.degree. F.
(about 93.3.degree. C.), and 230.degree. F. (about 110.degree. C.)
of the composite of the first embodiment with the two comparative
above-mentioned other multi-layer composite siding products. The
oven sag test does not use an actual sample of siding, but rather
uses a plaque made up of layers of materials which would be used to
make a siding product. The oven sag test correlates well with the
actual siding product. The oven sag test looks at the sag of a
sample bar under gravity load. One end of the bar is clamped while
the other end is free to sag. By employing a range of temperatures,
the temperature at which gross sag takes place can be found.
Samples of 0.125 inches (about 3.18 mm) thick plaques for each
composite to be tested were taken with a sag arm length set at 31/4
inches length (82.55 mm) The percent content of CPVC was varied for
each composite product.
[0054] The results of the test for the two layer PVC/CPVC composite
siding product with the CPVC layer on the bottom is shown in FIG.
5A. As seen in FIG. 5A, the two layer PVC/CPVC composite siding
product with the CPVC layer on the bottom significantly improved
sag resistance compared to the rigid PVC. As the CPVC content
increased, the sag decreased and the sag resistance increased.
[0055] The results of the test for the three layer PVC/CPVC/PVC
composite plaque product is show in FIG. 5B. This composite did not
show bending after processing due to symmetry of the layers.
[0056] The results of the test for the three layer CPVC/PVC/CPVC
composite plaque product of the exemplary embodiment is shown in
FIG. 5C. This composite product performed the best of the three
products tested in reducing sag at elevated temperatures even when
used at low concentrations of CPVC. For example, with a CPVC
content of 16% weight, this sample deflected less than 5 mm when
the Oven Sag Test was performed on it at 180.degree. F. (about
82.2.degree. C.), 200.degree. F. (about 93.3.degree. C.), and
230.degree. F. (about 110.degree. C.). Hence, from the standpoint
of sag resistance/stiffness retention at 180.degree. F.
temperature, the CPVC content can be as low as 16-24% weight. This
low percentage of CPVC reduced the costs of the product and thus,
made it the most economical choice among the three siding products
tested. Also, the symmetrical placement of the layers prevents
bending or distortion of the composite samples after processing and
produces the flattest specimens.
[0057] In the foregoing description, certain terms have been used
for brevity, clarity and understanding, however, no unnecessary
limitations are to be implied therefrom, because such terms are
used for descriptive purposes and are intended to be broadly
construed. Moreover, the descriptions and illustrations herein are
by way of examples and the invention is not limited to the exact
details shown and described.
[0058] In the following claims, any feature described as a means
for performing a function shall be construed as encompassing any
means known to those skilled in the art to be capable of performing
the recited function, and shall not be limited to the features and
structures shown herein or mere equivalents thereof. The
description of the exemplary embodiment included in the Abstract
included herewith shall not be deemed to limit the invention to
features described therein.
[0059] Having described the features, discoveries and principles of
the invention, the manner in which it is constructed and operated,
and the advantages and useful results attained; the new and useful
structures, devices, elements, arrangements, parts, combinations,
systems, equipment, operations, methods and relationships are set
forth in the appended claims.
* * * * *