Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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THERMOFORMABLE MULTILAYERED POL~ SHEET
This application claims the benefit of U.S. Provisional Application
60/041,015, filed March 19,1997 (Our Case 8CT-5680 PA).
Field of the Invention
This invention relates to a polyester composite sheet which may be
thermoformed into a variety of articles such as bathroom sinks and tubs.
Background of the Invention
Filled crystalline resin blends are often difficult to form into profiles or
sheet. Crystalline resin has poor melt strength and high shrinkage upon
cooling This makes it difficult to obtain thick sections with good dimensional
tolerances. Typically, extruded crystalline resins may also exhibit a very
rough ~u~a~e.
0 U.S. patent 5,441,997 describes polyester molding compositions which
have ceramic like qll~liti~, can be molded into relatively thin sections, and
have good impact strength. The composition is directed to a polybutylene
terephth~l~te and/or polyethylene terephthalate and an aromatic
polycarbonate with inorganic fillers selected from the group consisting of
barium sulfate, sL.ol~lium sulfate, zirconium oxide and zinc sulfate. If
desired, a styrene rubber impact modifier is described as added to the
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composition as well as a fibrous glass reillfo~ g filler. Although these
compositions are suited for many applications where ceramic like qualities
are desired, it is desirable to have even more irnproved and more economical
molded structures.
5U.S patent 5,510,398 to aar~, et al describes the use of the non-
dispe.~ g pigments to i~llyalL to a polyester thermoplastic composition a
granite, fleck-like or speckled surface appearance to an extruded sheet which
provides a separate, visibly distinct and identifiable color at numerous sites
across the surface of the material wherever the pigment material is visible.
oPotential non-dispersing pigments which are useful provided the aspect ratio
is suitable include titanium whiskers and other natural fibers as well as
ground thermosetting resin, thermoplastic or rubber m~t~n~l~. When added
to a filled polyester mAtPri~l, the resulting decolalive polyester composition
typically has chP~ l resistant properties. U.S. patent 5,304,592 to Ghahary
5relates to a simulated mLnelal article which co~ lises a plastic particulate oftherrnoplastic and thermosetting resin material within a therrnoplastic matrix.
It is desired to obtain further enhancements to polyester materials,
especially deco-clti~e filled type chemically resistant polyesters, which
enhancements include better thermoformability in large parts, greater
20stiffness, better i~ esislance, and higher heat l~si~t~-ce. Hence, it is
desirable to provide polyester materials having e~h~nce~ structural
~ro~e,Lies without detracting from the decorative surface and chemical
resistant ~lo~lies. Additionally, it is desirable to provide econornically
decolaLive and cl~mir~lly resistant polyester n~tPri~lc that exhibit reduced
25shrinkage and warpage with thick sections during molding operations.
U.S. patent 4,737,414 to Hirt et al describes a multilayer composite
wherein a layer co~ ising an aromatic polyetherimide is ~ c~rlt to a layer
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coL~ g an aromalic polyester. A tie layer of a copolyesleIcarbonate is
described.
Jullu~lal y of the Invention
The compositions of the present invention provide for an economical
polyester material having enhanced melt strength and elasticity without
s undesirably affecting the desirable decolaLive surface and ch~irAI resistant
~L'~ lies.
According to the ylesent invention, there is provided a therrnoplastic
composite comprising an extruded therrnoformable self-supporting sheet
having an outer decolaLi~re chemically resistant and renewable filled polyester
o layer and an ~ Pnt inner supporting thermoplastic layer for enhancing
desirable mechanical yroy~ lies of the composite.
The decolalive outer polyester layer com~,ises a colorant, an il,ol~,ic
filler, an effeclive amount of a stabilizer, a W stabilizer, and optionally
polycdlL,ol,ate, and/or an impact modifier.
For enhancing the mechanical yroyeiLies of the overall coll~yosile~ the
adjacent inner the~ll,o~lastic layer co~l~ylises a heat deformable layer having
mechanical y~oye~Lies such as impact resistance and melt strength which
desirably exceed these yro~e~ lies as possessed by the outer polyester layer.
Also, there is provided a ~rocess for yrepalillg a deco~ative article
COln~liS~ly; extruding a mllltil~yered sheet by feeding at least two diKerent
resin CGlllyOSil ;tnr~q to an extruder, extruding said at least two resin
coll,yo~ilions into the mllltil~yered self-su~olLing coextruded sheet, and
therrnofo"lui~g at least a portion of s~id coextruded sheet into a decorative
article wherein at least one exterior surface of the article coll,ylises one resin
- 25 and an adjacent layer com~iises the other resin. One resin co~ ises the
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decorative layer and the other layer comprises the s~ orlillg layer as
previously set fort~.
Description of the Plefe~led Embodiments
The thermoplastic cGlllyosiLe comprises an extruded therrnoforrnable
self-Yu~olLillg sheet having an outer decorative ~ A11y resistant filled
polyester layer and an adjacent thermoplastic s,l~o~L layer for enhancing
desirable IIlPchAnic~l ~rope~Lies of the composite. Both layers are forrned
from extrudable resin compositions. It is co~ lplated that a compatibilizing
or adhering layer may be included interrnediate to the decorative layer and
the ~uy~OlL layer. It is also contemplated that the support layer may be a
o larninate or multilayered structure including a regrind layer of unused or
scrap resin mAtPriAl that are desirable to be recycled. It is also conLem~lated
another polyester layer may be utilized adjacent the support layer so that the
entire exterior of the sheet, both top and boLLol~4 are formed from a
decorative polyester type mAtf~riAI
It is also cont~l~lated that the layer imn~PrliAtely ~djAcPnt the outer
deco~clLiYe layer be another layer of filled polyester material. Plefelably thissecond polyester layer is of a colored polyester material having a color which
is in contrast to the outer deco~dLive layer. By removing a portion of the outerlayer by mP~ ..ic~l or other means, the color of the adjacent layer will be
20 revealed. Hence, a decorative design may be imparted to the sheet material
using an A.ijp~P.~ layer which contrasts with the outer layer, _nd removing
the outer layer in a ~aLL~
The following ~liecllccion relating the ~ alaLion of a multilayered
co~ sile mAl~es rerel~llce to coextrusion of multiple layers using a plurality
25 of extruders. Each layer is desirably formed from a single extruder with
multiple layers formed by using a number of extruders col~e~onding to the
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number of layers desired and a suitable die assembly so as to yield the
~ at~loyliate number of layers.
According to the coextrusion ~focess, a plurality of standard extrusion
machines may be ~ e(1 Typically the extruder has a housing having a
5 central opeNng with a helical screw mounted for rotation along an axis
interior to a barrel portion. A motor drives the screw through a gear reducer.
At one end of the opening, a hopper is utilized for feeding material to be
extruded into the rear portion of the screw. Helical threads mounted on the
screw are positioned for moving material from the rear portion of the screw
o to a forward portion. As the material or feedstock is conveyed along the
screw, the feedstock is heated by frictional forces caused by rotation of the
screw. It is also c~ telllplated that an external heating source such as an
electrical res~ t heaters may be provided to heat the feedstock.
For forming a mt11til~yered coextruded sheet, feedstock in melted form
lS is fed from a re~pe-hve extruder to a die ~csemhly. Coextrusion ~y~lell~s forforming m~ yer film or sheets of thermoplastic materials are generally
known, as shown for example in DuBois and Pribble's "Plastics Mold
Engineering Handbook", Fifth Edition, 1995, pages 524 to 529. As described,
several streams of polymer melt from respective extruders are fed to a die
20 having a feedblock for combining the thermoplastic layers ~ heall~ of a die
exp~n.cion ~h~mh~r which is generally of the coathanger-type, also refelred to
as "fishtailn-type. From the point of combining the melt streams, the die is
used to form the combined melt streams into a sheet where the layers have
been spread to make a multilayered product. The thickness of each layer in
25 the final sheet is ~ Gl Lional to the thickness of its particular feed-block.
Other structures provide a die cavity for the reception of a sepalale
manifold so that the combining of the layers upon exiting the manifold takes
place within the die itself and is close as possible to the entrance to the
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expansion chamber. The manifold co~ ulises a plurality of slotted, layer
distribution passages opening into the eA~al~sion chamber, the passages
co~ lising ~ntltll~lly spaced apart openings lying parallel to the slotted die
opening.
s The resulting multilayed extruded sheet may be formed into a desired
shaped final article by thermofo~ g techni~ues known in the art.
TherrnoLollllillg comprises simultaneously heating and forming the extruded
sheet into the desired shape. Once the desired shape has be obtained, the
formed article is cooled below its thermoplastic Lelll~e~dture and removed
o from the mold. In vacuum molding, the extruded sheet is placed over a
concave mold and heated such as by an infra-red heater. Vacuum is applied
to draw the extruded sheet into place against the mold cavity. The above may
be modified by combining positive air ~ressu,c on top of the extruded sheet
with vacuum from the underside to increase the molding force. In rnatched
lS or coll~lession molding, matched male and female molds or dies are
employed and the extruded sheet is formed between the mechanically
co~ ressed molds. Molds are typically made from a metal having high
~herrnAl conductivity such as all~lUnUm. Thermofol~ g methods and tools
are described in detail- in DuBois and Pribble's "Plastics Mold Engineering
Handbook", Fifth F~ition, 1995, pages 468 to 498.
The outer dec~laL~e chemically resislan~ filled layer is a polyester
m~tf~ri~l Polyesle~ j include those comprising structural units of the
following for~
O O
o ~ 1 0 C A l C
2s wherein each R1 is independently a divalent aliphatic, alicyclic or aromatichydrocarbon or polyoxyalkylene radical, or mixtures thereof and each A1
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is independently a divalent aliphatic, alicyclic or aromatic radical, or
mixtures thereof. Examples of suitable polyeslers containing the StTUCture
of the above formula are poly(alkylene dicarboxylates), liquid crystalline
polyesters, and polyester copolymers. It is also possible to use a branched
polyester in which a branching agent, for example, a glycol having three or
more hydroxyl groups or a trifunctional or multifunctional carboxylic acid
has been in o~yo~dled~ Furtherrnore, it is sometimes desirable to have
various co~lc~ L~alions of acid and hydroxyl end groups on the polyester,
depending on the lll*m~te end-use of the composition.
o The Rl radical may be, for example, a C2 l0 alkylene radical, a
C6 12 alicyclic radical, a C6 20 aromatic radical or a polyoxyalkylene
radical in which the alkylene groups contain about 2-6 and most often 2 or
4 carbon atorns. The A1 radical in the above forrnula is most often p- or m-
phenylene, a cycloaliphatic or a rnixture thereof. This class of polyester
lS includes the poly(alkylene terephthalates). Such polyesters are known in
the art as illustrated by the following patents, which are incoryoldled
herein by fefe:~ellce.
2,465,319 2,720,502 2,727,881 2,822,348
3,047,539 3,671,487 3,953,394 4,128,526
~x~ll~lcs of aroll,alic dicarboxylic acids rey.es~l~led by the
di~bo~ylated residue Al are isophthalic or Lelephlllalic acid, 1,2-di(p-
ca.~.o,.y~henyl)ethane, 4,4'-dicalbOxydiphenyl ether, 4,4' bisbenzoic acid and
les lhe~eof. Acids colllaL. ing fused rings can also be present, such as in
1,4- 1,5- or 2,6- naphth~ne~lir~rboxylic acids. The y,~2fe~.ed dica~l~xylic
2s acids are terephthalic acid, isophthalic acid, naphthalene dica~l.oxylic acid,
cyclohexane dicalboxylic acid or mix~res thereof.
The most yi~elled polyesters are poly(ethylene Lel~eyhlhalate) ("PET"),
and poly(1,4-butylene terephthalate), ("PBT"), poly(ethylene naphthanoate)
.
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("PEN"), poly(butylene naphthanoate), ("PBN") and (polypropylene
terephthalate) ("PPT"), and mixlule3 thereof.
Also colllelllylated herein are the above polyesters with minor
amounts, e.g., from about 0.5 to about 5 yercent by weight, of units derived
s from aliphatic acid and/or aliphatic polyols to form copolyeal~ s. The
aliphatic polyols include glycols, such as poly(ethylene glycol) or
poly(butylene glycol). Such polyesle~s can be made following the teachings
of, for example, U.S. Pat. Nos. 2,465,319 and 3,047,539.
The yref~ ed poly(1,4-butylene terephthalate) resin used in this
o invention is one obtained by polymerizing a glycol component at least 70 mol
%, plefelably at least 80 mol %, of which consists of tetramethylene glycol and
an acid or ester co-~lyu-lent at least 70 mol %, ylefe~ably at least 80 mol %, of
which consists of terephthalic acid, and polyester-forrning derivatives
therefole.
The yref~ed polyesl~ used herein have an i~lLIillaic viscosity of from
about 0.4 to about 2.0 dl/g as rne~cllred in a 60:40 phenol/tetrachloroethane
u~e or similar solvent at 230-30o C. Preferably the illllillsic viscosity is 1.1to 1.4 dl/ g.
Pre~fdbly, the polyester composition includes a decorative
component Typical decG~alive components include colorants in the form of
dyes and fillers. One such decorative colorant is ~eS~nhe~l in U.S. patent
5,510,398 to aark et al. A speckled surface is achieved through a non-
disyel jing pigment as opposed to a filler because the non-di~pe~ jing pigment
does not a~yreciably add to the base color of the resin. Rather, the non-
disy~ g pigment provides a separate, visibly distinct and identifiable color
at numerous sites across the surface of the material wherever the pigment
material is visible. In other words, the speckle is visible in the filled polymer
matrix as a distinct region of contrasting color.
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The p~felled polyester composition is a blend with a polycarbonate
resin. Polycarbonate resins useful in ~e~aring the blends of the ~resent
invention are p~Ffe~ably aromatic polycall~ol,ate resins. Typically these
polycarbonates are ~Le~aled by reacting a dihydric phenol with a carbonate
5 pre~u~or, such as phosgene, a haloformate or a carbonate ester. Carbonate
polymers may be typified as possessing recurring structural units of the
forrnula
o
Il
_o--A O C
wherein A is a divalent aromatic radical of the dihydric phenol
o employed in the polymer producing reaction. The dihydric phenols which
may be employed to provide such aromatic carbonate polymers are
mononuclear or polynuclear aromatic compounds, col~tdil~ing as functional
groups two hydroxy radicals, each of which is attached directly to a carbon
atom of an aromatic nucleus. Typical dihydric phenols are: 2,2-bis(4-
5 hydroxyphenyl) ~lo~.e; hydroquinone; resorcinol; 2,2-bis(4-hydroxyphenyl)
E,elltane; 2,4'-(dihydr~,xydiphenyl) methane; bis(2-hydroxyphenyl) methane;
bis(4-hydroxy~henyl) methane; 1,1-bis(4-hydroxyphenyl)-3,3,5-
trirnethylcyclohexane; fluorenone bisphenol, 1,1-bis(4-hyd.oxy~henyl)
ethane; 3,3-bis(4-hy~o,~y~henyl) pentane; 2,2-dil-y~oxydi~henyl; 2,6-
20 dihy~xy~ ht~ on~; bis(4-hydroxydiphenyl)sulfone; bis(3,5-diethyl~
hydroAypllenyl)sulfone; 2,2-bis(3,5-dibromo~-hydroxyphenyl)~ro~,e; 2,2-
bis(3,5-dirnethyl 1 hydroxy~henyl)propane; 2,4'-dihydroxydiphenyl sulfone;
5'~hloro-2,4'-dihydroxydiphenyl sulfone; bis-(4-hydroxyphenyl)diphenyl
sulfone; 4,4'-dihydroxydiphenyl ether; 4,4'-dihydroxy-3,3'-dichlorodiphenyl
25 ether; 4,4-dihydroxy-2,5-dihydroxydiphenvl ether; and the like.
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Other dihydric phenols which are also suitable for use in the
dtion of the above polycalbollates are disclosed in U.S. Pat Nos.
2,999,835; 3,038,365; 3,334,154; and 4,131,575.
These aromatic polycarluol-ates can be rnanufactured by known
s processes, such as, for exarnple and as mentioned above, by reacting a
dihydric phenol with a carbonate precursor, such as phosgene, in accordance
with methods set forth in the above-cited literature and in U.S. Pat. No.
4,123,436, or by transesterification processes such as are disclosed in U.S. Pat.
No. 3,153,008, as well as other processes known to those skilled in the art.
It is also possible to employ two or more different dihydric phenols or
a copolymer of a dihydric phenol with a glycol or with a hydroxy- or acid-
terminated polyester or with a dibasic acid in the event a carbonate
copolymer or interpolymer rather than a homopolymer is desired for use in
the preparation of the polycarbonate ~l.ixlules of the invention. .Polyarylates
5 and polyester-carbonate resins or their blends can also be employed.
Branched polycall,ol ates are also useful, such as are described in U.S. Pat.
No. 4,001,184. Also, there can be utilized blends of linear polycarbo~ e and a
branched polyc~l,onate. Moreover, blends of any of the above materials may
be employed in the practice of this invention to provide the aromatic
20 polycall,ol.ate.
In any event, the ylefe~ed aromatic carbonate for use in the practice in
the y~sent illvt:nlion is a homopolymer, e.g., a ho~lloyolymer derived from
2,2-bis(~hydro,.yyhenyl)propane (bisphenol-A) and phosgene, commercially
available under the trade designation LEXAN Registered TM from General
25 Electric Colllyarly.
The instant polycarl,ol~ate~ are yrefelably high molecular weight
aromatic carbonate polymers having an intrinsic viscosity, as ~let~ ;"ed in
chloloLollll at 250 C of from about 0.3 to about 1.5 dl/grrl, yrefe~ably from
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about 0.45 to about 1.0 dl/gm. These polycarbonates may be branched or
unbranched and generally will have a weight average molecular weight of
from about 10,000 to about 200,000, y,e~ldbly from about 20,000 to about
100,000 as measured by gel permeation chromatography.
s The branched polycarl,ollates may be prepared by adding a branching
agent during polymerization. These branching agents are well known and
may comprise pol~fullclional organic co~ oul-ds containing at least three
functional groups which may be hydroxyl, Ca1~OAY1~ ca~l,o~ylic anhydride,
haloformyl and mixtures thereof. Specific examples include trimellitic acid,
o trimellitic anhydride, trirnellitic trichloride, tris-p-hydroxy phenyl ethane,
isatin-bis-phenol,tris-phenol TC (1,3,5-tris((p-
hydroxyphenyl)isGylo~yl)benzene),tris-phenol PA (4(4(1,1-bis(p-
hy~ o~yl~henyl)-ethyl)alpha~ alpha-dimethyl benzyl)phenol), 4-chlorofo~ yl
phthalic anhydride, trimesic acid and benzophenone tetracarboxylic acid.
IS The ~Jiallching agent may be added at a level of about 0.05-2.0 weight y~cellt.
Branching agents and procedures for making branched polycal).ol.att:s are
~1~c~rihe~ in U.S. Letters Pat. Nos. 3,63~,895; 4,001,184; and 4,204,047 which
are incol~olaLed by r~felcnce. All types of polycarL,ollate end ~,ro~l~s are
conlel~l~lated as being within the scope of the ~lesellt invention.
It is further ~ ed to employ an inorganic filler to the thermoplastic
resin to i~llyall A~li*OrlAl beneficial properties such as thPrrnAI stability,
increased density, and le,.l~. Inorganic fillers provide a ceramic-like feel to
articles th~rmoforn~e~l from resin composition. Pl~f~,.ed inorganic fillers
which are employed in the present thermoplastic compositions include: zinc
oxide, l~ariulll sulfate, ~irc~,lliuln silicate, shonli-m~ sulfate, as well as
s of the above. The yle~Lled form of barium sulfate will have a
particle size of 0.1-20 microns. The barium sulfate may be derived from a
natural or a SYnL1leliC source.
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The molding co~ osilions may include from 20 - 85% by weight,
~.efe~ably 30 - 75% by weight or most ~referably 30 - 45% by weight of total
coll~osilion of an inorganic filler colll~o.lent. For certain applications wherea ceramic like product is desired, more than 50%, or more ~refelably 60 - 85%
s by weight of the total composition of filler component should be employed.
The filler material is chosen to enhance the decoralive ~fo~elLies and the
renewable properties of the resin sheet. The metal sulfate salts as well as their
hydrates are ~vrefel~ed mineral fillers. Plefe,led metal sulfate salts are the
Group IA and Group IIA metal sulfates with barium, calcium and magnesium
l0 sulfates being prefe~.ed. Barium sulfate which is non-toxic and insoluble in
dilute acids is especially ~lefelled. Barium sulfate may be in the form of the
naturally OccL~ g balyLes or as synthetically derived baliulll sulfate using
well known synthetic techniques. The particle size may vary from 0.5 to 50
microns, ~reLe~dbly from 1 to 15 microns and most pl~felably 8 rnicrons.
The coln~osilion desirably contains impact modifiers such as a rubbery
impact modifier. r~fe~dbly such impact modifiers are utilized in an amount
less than about 30, and plefelably less than about 20 pcrcell~, more ~leferdbly
less than about 15 ~ere~llt by weight based on the total weight of the
composition.
The l,lefe.led th~rrnofo~ll~lg additives for thermofoillii~.g have a
linear or radial (branched) A-B-A block structure. They include styrene-
but~ ne-styrene (SBS) and styrene-isoprene-styrene (SIS). A diblock
polymer of the type styrene-ethylene/propylene (SEP) is also included. The
most ~reLelled thermofoll-~g additive is of the A-~A block structure of the
type styrene-ethylene/butylene styrene (S-EB-S).
The filled polyester molding composition includes a polyester resin, an
inorgaruc filler material, a polycarbonate resin; and an eLLe.live amount of a
styrenic modifier which may include random, block, and radial block
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- 13 -
copolymers. A particularly useful class of modifiers conl~lises the AB
(diblock) and ABA (triblock) copolymers alkenylaromatic col~ounds,
especially those co-,l~,ising styrene blocks. The conjugated diene blocks may
be ~lls~ dled~ partially or entirely hydrogenated, whereupon they may be
5 re~ie3ented as ethylene-propylene blocks or the like and have ~ulo~e~lies
similar to those of olefin block copolymers. Examples of triblock copolymers
of this type are poly~ly,e.le-polybutadiene-polyslyl~,le (SBS), hydrogenated
polysly~t:ne-polybutadiene-polystyrene (SEBS), poly~ly.~l,e-polyisoprene-
poly~lyLt:lle (SIS), poly (a-methylstyrene)-polybutadiene-poly(a-
o methylstyrene) and poly(a-methylstyrene)-polyisoprene-poly(a-
methylstyrene). ParticuIarly t,re~ed triblock copolymers are available
commercially as CARIFLEZ~), lCraton D~, and KRATON G~ from Shell.
Typical impact modifiers are derived from one or more monomers
selected from the group consisting of olefins, vinyl aromatic monomers,
s acrylic and alkylacrylic acids and their ester deliv~tives as well as conjugated
dienes. Impact modifiers include the rubbery high-molecular weight
materials including natural and synthetic polymeric materials showing
elasticity at room lel~ dl~lle. They include both homopolymers and
copolymers, including random, block, radial block, graft and core-shell
20 copolymers as well as combinations thereof. Suitable modifiers include core-
shell polymers built up from a rubber-like core on which one or more shells
have been grafted. The core typically consists substantially of an acrylate
rubber or a butadiene rubber. One or more shells typically are grafted on the
core. The shell ~refe~ably comprises a vinylaromatic colll~oulld and/or a
25 vinylcyanide and/or an alkyl(meth)acrylate. The core and/or the shell(s)
often colll~lise multi-functional compounds which may act as a cross-linking
agent and/or as a grafting agent. These polvmers are usually prepared in
several stages.
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Olefin-containing copolymers such as olefin acrylates and olefin diene
terpolymers can also be used as irnpact modifiers in the present compositions.
An example of an olefin acrylate copolymer impact modifier is ethylene
ethylacrylate. Other higher olefin monomers can be employed in copolymers
5 with alkyl acrylates, for example, propylene and n-butyl acrylate. The olefin
diene terpolymers are well known in the art and generally fall into the EPDM
(ethylene propylene diene) farnily of terpolymers. Polyolefins such as
polyethylene, polyethylene copolymers with alpha olefins are also of use in
these compositions. Polyolefin copolymers with gylcidyl acrylates or
o methacrylates may be especially effective in the impact modification of
polyester containing blends.
Styrene-cGnldi~ g polymers can also be used as impact modifiers.
Examples of such polymers are acrylonitrile-butadiene-styrene (ABS),
acrylonitrile-butadiene-alpha-methylstyrene, styrene-b lt~C~iene, styrene
butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS),
methacrylate-butadiene-styrene (MBS), and other high impact styrene-
containing polymers.
Impact modifiers are typically based on a high molecular weight
styrene-diene rubber. A pre~ed class of rubber materials are copolymers,
20 including random, block and graft copolymers of vinyl aromatic compounds
and conitlg~t~l dienes. Exemplary of these materials there may be given
hydro~ .1, partially hydrogenated, or non-hydrogenated block
copolymers of the A-B-A and A-B type wherein A is poly~lyl~ e and B is an
elastomeric diene, e.g. polybutadiene, polyisoprene, radial teleblock
25 copolymer of styrene and a Y conjugated diene, acrylic resin modified
styrene-butadiene resins and the like; and graft copolymers obtained by graft-
copolym~n~hon of a monomer or monomer mix containing a styrenic
co.11pol,nd as the main co~ onent to a rubber-like polymer. The rubber-like
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-15-
polymer used in the graft copolymer are as already described herein
including polybutadiene, styrene-butadiene copolymer, acrylonitrile-
butadiene copolymer, ethylene-propylene copolymer, ethylene butylene
copolymer, polyacrylate and the like. The styrenic co~ ou~-ds includes
styrene, methylstyrene, dimethylstyrene, isopropylstyrene, a-methylstyrene,
ethylvinyltoluene and the like.
Procedures for the preparation of these polymers are found in U.S.
Patent Nos. 4,196,116; 3,299,174 and 3,333,024, all of which are incol~oi~lted
by ref~ e.
o An effective arnount of a block copolymer of the A-B-A may be utilized
as impact modifier. In accordance with the principles of the ~esel.t
illvel~Lion, the A-B-A type ingredient is present an amount sufficient for
enhancing the thermo-formability of articles produced from the resin. A is a
polymerized mono-alkenyl aromatic hydrocarbon block and B is polymerized
lS conJugated diene hydroca.bon block.
In the above type, blocks A typically consliL.Il;.,g 3-50 weight percent
of the copolymer and the unsaturation of block B having been reduced by
hydrogenation. The filled polyester molding composition of the present
il~v~llLion co~ ises from 5~0 parts by weight, and ~ref~lably 10-30 parts by
weight of the block copolymer.
With res~ecl to the hydrogenated block copolymers of the A-B-A type,
they are made by means known in the art and they are commercially
available.
These materials are described in U.S. Pat. No. 3,421,323 to Jones,
which is hereby incor~o.aLed by refelence.
Prior to hydrogenation, the end blocks of these copolymers comprise
homopolymers or copolymers t,lefe~ably prepared from alkenyl aromatic
hydrocalbul~s and particularly vinyl aromatic hydlocalbons wherein the
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aromatic moiety may be either monocyclic or polycyclic. Typical monomers
include styrene, alpha methyl styrene, vinyl xylene, ethyl vinyl xylene, vinyl
naphthalene and the like or ~ Lul~es thereof. The end blocks may be the same
or di~elel~t. The center block may be derived from, for example, polyisoprene
or polybutadiene.
The ratio of the copolymers and the average molecular weights can
vary broadly although the molecular weight of center block should be grealel
than that of the combined terminal blocks. Typically, terminal blocks A have
average molecular weights of 4,000-115,000 and center block B e.g., a
0 polybutadiene block with an average molecular weight of 20,000450,000. Still
more ~refer.tbly, the terminal blocks have average molecular weights of 8,000-
60,000 while the polybutadiene polymer blocks has an average molecular
weight between 50,000 and 300,000. The terminal blocks may colllylise 2-50%
by weight, or more ~reLelably, 5-30% by weight of the total block polymer.
The ~refel~ed copolymers will be those formed from a copolymer having a
polybllt~ Prle center block wherein 35-55%, or more yrefelably~ 40-50% of the
butadiene carbon atoms are vinyl side chains.
Block copolymers such as Kraton G-GXT-0650, Kraton G-GXT-0772 and
Kraton G-GXT-0782 are available from Shell Chemical Company, Polymers
Division.
Block copolmers of the A-~A type may also be considered with
re~e.L to the formula A'-B'-A' block copolymers.
The ratio of the co-monomers may vary broadly. Typically, the the
molecular weight center block is greater than that of the combined terminal
2s blocks. Preferably, with the above limitation, the molecular weight of the
terminal Wocks each will range from about 2000 to about 100,000 while that of
the center block will range from about 25,000 to about 1,000,000.
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The impact modifier is desirable present in an amount from 0 to 40
percent by weight, ~refeldble from 4 to 15 ~ereenl, for deep drawing sheets, a
higher level on the order from 20 to 40 percent is ~.e~ d.
In the thermoplastic compositions which cGllla~ a polyester and a
5 polycarbonate resin, it is plefelable to use a stabilizer material. Typically,such stabilizers are used at a level of 0.01-10 weight percent and ~lefe~ably ata level of from 0.05-2 weight ~e~cent.
The pre~ ed stabilizers include an effective amount of an acidic
phosphate salt; an acid, allcyl, aryl or mixed phosphite having at least one
o hydrogen or alkyl group; a Group IB or Group IIB metal phosphate salt; a
phosphorous oxo acid, a metal acid pyrophosphate or a ll~lure thereof. The
suitability of a particular coll-~oul~d for use as a stabilizer and the
determination of how much is to be used as a stabilizer rnay be readily
deL~ lulled by preparing a lni~Lule of the polyester component, the
5 polycarbonate and the filler with and without the ~alLi-ular compound and
determining the effect on melt viscosity or color stability or the formation of
inlelpolymer. The acidic phosphate salts include sodium dihydrogen
phosphate, mono zinc phosphate, potassium hydrogen phosphate, calcium
hydrogen phosphate and the like. The phosphites may be of the forrnula:
R6o-?-oR7
oR8
where R6, R7 and R8 are independently c~lecte-l from the group
consisting of hydrogen, alkyl and aryl with the proviso that at least one of R6,R7 and R8 is hydrogen or aL~cyl.
The phosphate salts of a Group IB or Group IIB metal include zinc
phosphate, copper phosphate and the like. The phosphorous oxo acids
include phosphorous acid, phosphoric acid, polyphosphoric acid or
hypophosphorous acid.
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The polyacid pyrophosphates of the formula:
MZx Hy Pn ~3n+1
wherein M is a metal, x is a number ranging from 1 to 12 and y is a
number ranging 1 to 12, n is a number from 2 to 10, z is a number from 1 to 5
and the sum of (xz)+y is equal to n+2.
These compounds include Na3HP2O7; K2H2P2O7; Na4P2O7;
KNaH2P207 and Na2H2P2O7. The particle size of the polyacid
pyrophosphate should be less than 75 microns, ~lefe~dbly less than 50
microns and most yrefelably less than 20 microns.
o The ~refe,red polyester layer comprises a decorative component,
polycarbonate, an organic filler, a reinforcing material, and a stabilizer. The
polyester material ~referdbly comtJ~ises EnduranTM 7322 available from the
GE Plastics coml.onent of General Electric Company is a plefelled polyester
resin material for the outer layer.
IS A ~efelled composition includes the following: polyester from
about 10 to about 40 yel'cellt by weight, preferably the polyester comprising
polybutylene terephthalate in an amount from about 7 to about 25 ~elcel.t
and polyethylene terephthalate from about 3 to about 10 percent, aromatic
polycarbo,lale from about 10 to about 25 percent, stabilizer from about 0.01
to about 10 percent, impact modifier from 4 to about 15 percent, barium
sulfate from about 30 to about 40 percent, with pigment or dyes being present
in an e~e~Lve amount to generate the desired surface effect and when
combined with ~ itinnal ingredients being present in an amount less than
about 5 percent.
An adjacent thermoplastic support layer co~ ises a heat deformable
material having mechanical pn~p~lies such as impact resistance and melt
strength which desirably exceed such properties of the decorative polyester
layer so as to enhance the mechanical properties of the composite. Suitable
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thermoplastiC organic polymers for the inner layer includes acrylonitrile-
butadiene-styrene (ABS), polycarbonate, polycarbonate/ ABS blend, a
copolycarbonate-polyester, acrylic-styrene-acrylonitrile (ASA), acrylonitrile-
(ethylene-poly~o~ylene diamine modified)-styrene (AES), phenylene ether
resins, blends of polyphenylene ether/polyamide (NORYL GIX~) from
General Electric Company), blends of polycarbonate/polybutylene
terephthalate and impact modifier (XENOY~ resin from GeneraI Electric
Company) blends of polycarbonate/PET/PBT, polyarnides, phenylene sulfide
resins, ), poly(vinyl chloride) PVC, polymethylmethacrylate (PMMA), and
High-impact Poly~Ly~ e (HIPS
A plef~lled composition for the support layer comprises an ABS type
polymer. In general, ABS type polymers contain two or more polymeric parts
of different co~ osilions which are bonded chemically. The polymer is
~refeldbly E~re~ared by polymerizing a conjugated diene, such as butadiene
lS or a conjugated diene with a monomer copolymerizable therewith, such as
styrene, to provide a polymeric backbone. After formation of the backbone, at
least one grafting monomer, and preferably two, are polymerized in the
presence of the prepolymerized backbone to obtain the graft polymer. These
resins are prepared by methods well known in the art.
The backbone polymer, as mentioned, is ~re~eldbly a conjl-~te~ diene
polymer such as polybutadiene, polyisoprene, or a copolymer, such as
bu~tli~ne-styrene, butadiene-acrylonitrile, or the like. Examples of dienes
that may be used are butadiene, isoprene, 1,3-hepta-diene, methyl-1,3-
pe~t~ P, 2,3-dimethyl-1,3-butadiene, ~-ethyl-1,3-pentadiene; 1,3- and 2,~
2s h~x~c1ierles, chloro and bromo substituted butadienes such as
dichlorobutadiene, bromobutadiene, debromobutadiene, mixtures thereof,
and the like. A p~e~"ed conjugated diene is butadiene.
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One monomer or group of monomers that may be polymerized in the
presence of the prepolymerized backbone are monovinylaromatic
hydrocarbons. Examples of the monovinylaromatic compounds and alkyl-,
cycloalkyl-, aryl-, alkaryl-, arallcyl-, alkoxy-, aryloxy-, and other substituted
5 vinylaromatic coll.pounds include styrene, 3-methylstyrene; 3,5-
diethylstyrene, 4-n-propylstyrene, alpha -methylstyrene, alpha -methyl
vinyltoluene, alpha -chlorostyrene, alpha -bromostyrene, dichlorostyrene,
dibromostyrene, tetra-chlorostyrene, mixtures thereof, and the like. The
~lefelled monovinylaromatic hydrocarbons used are styrene and/or alpha-
lo methylstyrene.
A second group of monomers that may be polymerized in the presenceof the prepolymerized backbone are acrylic monomers such as acrylonitrile,
subsliluled acrylonitrile and/or acrylic acid esters, exemplified by
acrylonitrile, and alkyl acrylates such as methyl methacrylate. Examples of
IS such monomers include acrylonitrile, ethacrylonitrile, methacrylonitrile,
alpha -chloroacrylonitrile, beta -chloroacrylonitrile, alpha -bromoacrylonitrile,
and beta -bromoacrylonitrile, methyl acrylate, methyl methacrylate, ethyl
acrylate, butyl acrylate, propyl acrylate, isoyn~ l acrylate, and mixl~lres
thereof. The p~ led acrylic monomer is acrylonitrile and the E,reftlled
20 acrylic acid esters are ethyl acrylate and methyl methacrylate.
In the preparation of the graft polymer, the conjl-g~te-l diolefin
polymer or copolymer exemplified by a 1,3-butA~ e polymer or copolyrner
co~ lises about 50% by weight of the total graft polymer composition. The
monomers polymerized in the presence of the backbone, exemplified by
25 styrene and acrylonitrile, com~lise from about 40 to about 95% by weight of
the total graft polymer col~,~osilion.
The second group of grafting monomers, exemplified by acrylonitrile,
ethyl acrylate or methyl methacrylate, of the graft polymer composition,
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preferably co...l,lise from about 10% to about 40% by weight of the total graft
copolymer composition. The monovinyiaromatic hydrocarbon exemplified by
styrene comprise from about 30 to about 70% by weight of the total graft
polymer composition.
5In preparing the polymer, it is normal to have a certain percentage of
the polymerizing monomers that are grafted on the backbone combine with
each other and occur as free copolymer. If styrene is utilized as one of the
grafting monomers and acrylonitrile as the second grafting monomer, a
certain por*on of the composition will copolymerize as free styrene-
oacrylonitrile copolymer. In the case where alpha -methylstyrene (or other
monomer) is sul)sli~ d for the styrene in the composition used in preparing
the graft polymer, a certain percentage of the composition may be an alpha -
methylstyrene-acrylonitrile copolymer. Also, there are occasions where a
copolymer, such as alpha -methylstyrene-acrylonitrile, is added to the graft
5polymer copolymer blend. When the graft as polymer-copolymer blend is
referred to herein, it is meant optionally to include at least one copolymer
blended with the graft polymer composition and which may contain up to
90% of free copolymer.
Optionally, the elastomeric backbone may be an acrylate rubber, such
20as one based on n-butyl acrylate, ethylacrylate, 2-ethylhexylacrylate, and thelike. A~l~li*on~lly, minor amounts of a diene may be copolymerized in the
acrylate rubber backbone to yield improved grafting with the matrix polymer.
The pl~fel~ed ABS material for the support layer comprises Cycolac~
GPX3800 and Cycolac~) I~A resin available from the GE Plastics colnl,olLent
25of General Electric Company.
Additional material for the support layer include polycarbonate and
polycarbonate blends. The polycarbonate is as before described with Lexan(~)
resin available from GE Plastics component of General Electric Company a
,
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WO 98/41399 PCT/US98/05108
~refelled polycarbonate. Resin blends of polycarbonate may also be used.
P~èfe~led polycarbonate resin blends include Xenoy(~1731, a polycarbonate
poly (butylene terphthalate) blend, Cycoloy~MC8002 and MC8100 blends of
polycarbonate and ABS.
Typical polyphenylene ether resin is a poly(2,6-dimethyl-1,4-
phenylene)ether resin having an intrinsic viscosity of from about 0.3 dl/g to
about 0.60 dl/g in chloroform. The polyphenylene ether resins useful herein
are well known in the art and may be prepared from a number of catalytic
and non-catalytic processes from corresponding phenols or reactive derivates
o thereof. Examples of polyphenylene ethers and methods for their production
are disclosed in U.S. Pat. Nos. 3,306,874; 3,306,875; 3,257,357 and 3,257,358, all
incorporated herein by refe~e~ce.
Typical polyamides suitable for the present invention may be obtained
by polymerizing a monoamino monocarboxylic acid or a lactam thereof
having at least 2 carbon atoms between the amino and carboxylic acid group;
or by polyrnPri~ing substantially equimolar l,ro~orlions of a diamine which
contains at least 2 carbon atoms between the amino ~,lOU~/S and a dicarboxylic
acid; or by polymerizing a monoaminocarboxylic acid or a lactam thereof as
defined above together with substantially equimolecular ~ro~olLions of a
diamine and a dica~,o~-ylic acid. The dicarboxylic acid may be used in the
form of a functional delivaLive thereof, for example an ester.
Multilayer structures of ENDURAN~ 73~ resin with other resins offer
lower cost alternatives to monolayer ENDURAN~) 73~ resin while
maintaining the surface appearance of a ENDURAN(8) 73~ resin layer by
substituting a portion of the ENDURAN(~)7322 resin layer with lower cost
resins. Performance ~ro~ ies such as stiffness, heat resistance, impact
resistance and/or flamrnability in the structures are i~ oved by
inc~ lating materials which enhance these yLo~e~ lies relative to the
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- 23 -
performance of monolayer ENDURAN~) 7322 resin- Processing advantages
in thermoforming are also realized by inco~)o~ating materials with greater
melt strength than the monolayer structure so that larger parts may be
thermofo~ e~
Multilayer structures of ENDURAN~) 7322 can be combined with
various other resins to create systems with reduced cost and/or improved
o~ll,ance. These other resins include ABS (CYCOLAC(~ GPX3800 resin,
CYCOLAC~) LSA resin), PC/PBT blends (XENOY~ resin), polycarbonate
(LEXAN~) resin), PC/ABS blends (CYCOLOY~ MC8002 resin, CYCOLOY(~
o MC8100 resin), PPO~) resin based blends (NORYL~ resin), poly(vinyl
chloride) PVC, and High-impact Polystyrene (HIPS). These resins may also
contain reinforcing fillers (such as glass fibers) which increase stiffness of the
structure.
These structures may be produced by coextrusion and may consist of
one or more different materials in addition to the ENDURAN~ 73Z layer.
Layers may include regrind material. Sheet produced by coextrusion may be
then thermoformed to fabricate parts. Sheet or fabricated parts maintain the
surface qll~lities (a~earal~ce, feel, etc.) of monolayer ENDURAN~ 73Z
products and may also be used with special color effects used with
ENDURAN~ 7322 monolayer sheet.
Thermofo~ning of the sheet is perforrned by placing the sheet over a
concave mold and heated such as by an infra-red heater. Vacuum is applied
to draw the extruded sheet into place against the mold cavity. Combinations
of ENDURAN(~ 7322 with CYCOLAC~ GPX3800, CYCOLAC~ LSA, and
CYCOLOY(~ MC8002 have been co-extruded and thermoformed on a 12" x
12" tool with 1" depth. All three combinations have produced good ~uality
sheet with good adhesion and material compatibility. Thermoformed parts
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-24-
retained adhesion of layers and surface quality. Other combinations are being
extruded and thermoformed.
Multilayer structures can be used either as surfacing materials (for
counl~lLo~s or wall coverings) in the form of coextruded sheet, or in any
s thermofol.~ g application involving ENDURAN~) 7322 resin such as sinks
or tubs.
Pl~f~lled thickness for the outer decorative layer is from about 0.002
inch (2 mils) to about .250 inch (0.250 mils) with ~lefe~ed thicknesses of the
backing thermoplastic layer being from about 0.050 inch (50 mils) to about
.500 inch (500 rnils).
rlefelled multilayered structures include the following as set forth
below:
EnduranTM resin/Cycolac(g) resin for thermofollllillg sinks and other
articles.
lS A two layered structure having a total thickness of 200 to 400 mils,
~vre~e~ably 300 mils, with the outer cap layer being 15 to 40 percent of the total
thi-~knP~s
EnduranTM resin/Cycolac~) resin for surfacing applications such as
counters and wall.
A two layered structure having a total thickness of 90 to 125 mils, with
the outer cap layer being 15 to 30 percent of the total thickness.
~nrlllranTM resin/ EnduranTM resin for decolaLive surfacing
applications such as counlels and wall where a pattern is developed by
removal of a portion of the outer layer to expose an A~jAcent layer.
A two layered structure having a total thickness of 90 to 125 mils, with
the outer cap layer being 15 to 30 percent of the total thickness.
A two layer structure comprises En~iuranTM resin/ Cycolact~) resin and
regrind lllix.L~ile. The outer cap layer is al~out 33% of the total thickness. The
-
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-25-
total thickness is 90 rnils. The Cycolac(l~) resin and regrind lllixlure contains
50% by weight regrind.
A three layer structure coln~lises is EnduranTM resin/Cycolac~) resin
and regrind mL~clule/cycolac(~) resin. The outer cap layer is about 33% of the
5 total thickness. The total thickness is 90 mils. The Cycolac(g~ resin and
regrind mixture conlains 50% by weight regrind. The boll~ layer of
Cycolac~) resin is 33% of the total thickness. As referred to in these examples,the regrind layer comprises polyester resin and acrylonitrile-butadiene-
styrene resin which remain after processing in the forrn of scrap and excess
10 material. The scrap material is ground and incorporated into the
multilayered structure as a separate layer or as part of an acrylonitrile-
butadiene-styrene resin layer.
A most ~ef~lled two layer structure co~ lises a co-extruded layer of
EnduranTM 7322 resin, Table 1, adjacent a layer of Cycolac(~) 29344A resin,
Table 2. EnduranTM resin and Cycolac(~) resin are available from the GE
Plastics col~l~Gnent of General Electric Company.
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Table 1 - EnduranTM resin wt% of ingredient based on total wt%
Valox~ 315 resin - poly(butylene terephthalate) - General Electric 17.45
Company
Lexan(~ 131 resin - polycarbonate - General Electric Company 27.25
poly(ethylene terephthalate) 9.8
Kraton G 1651 SEBS a slly~n-ethylene butylene-styrene block 7.5
copolymer - Shell Chemical Co.
BaS04 37.0
PETS - tetrakis(methylene(3,5-di-tert-butyl-4- 0.2
hydroxyhydrocinnamate))methane
TINWIN 234 - W absorber (Tinuvin 234, a benzotriazole 0.3
PEP-Q - tetrakis(2,4-di-tert-butylphenyl)4,4'- 0.3
biphenylenediphosphonite (Sar~lostAb P-EPZ phosphonite
Irgafos 168 0.1
MZP Mono zinc phosphate dihydrate (Zn(H2PO4)2H20) 0.1
Table 2 - Cycolac~ resin wt% of ingredient based on total wt%
360 HRG - High Rubber Graft ABS 60
570 SAN - styrene-acrylonitrile 40
Pluronic F-88 - 0.2
wingstay~) L antioxidant stabilizer 0.15
Ultranox~ 626 stabilizer - GE Specialty Chemicals 0.2
silicone fluid 0.10
Santicizer 0.40
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The desired thickness of the co-extruded sheet is somewhat dependent upon
the use of the sheet. Generally, an overall thickness of from 0.02 to 0.50 inch
is ~e~ ed with the thickness of the Enduran resin layer being from about 5
to about 85 percent of the total thickness. Some of the l,refelled thickness fors different type of uses are set forth in the Table 3.
Table 3 - Thickness of Enduran resin/Cycolac resin co-extruded layers
Total Sheet Thickness % Enduran
Shower Wall Surrounds 0.065 20%
Kitchen/bathroom Counters 0.090 40%
Shower Trays o.~o 20%
Lavatory Tops 0.210 20%
Standard size Bathtubs 0.250 30%
Large Jacuzzi Bathtubs 0.285 30%
For a co-extruded two layer sneet, it is highly desirable that the layers
be co~ alible so that the layers adhere. It is desirable to avoid ingredients inone layer that might react with the ingredients in the other layer. The above
o layers are compatible and are characterized by the absence of reactive
materials such as some metal oxides such as magnesium oxide.
To achieve sound damping, it is contemplated that a foam layer may
be adjacent the su~uil or inner layer. Typically, the foam layer has a 10 to
50% density reduction for lower cost, weight reduction and sound damping.
IS The foam may be foamed in place. See U.S. 5,486,407 to Noell et. al. It is also
contemplated that the inner support layer may be adhered to a cellulosic
based material such as a particleboard, fiberboard, chipboard or plywood. It
is also contemplated that abrasive resistant coatings such as described in U.S.
5,4~6,767 may be utilized in conjunction with the present invention.
Thermoforming methods may be utilized as set forth in U.S. 5,601,679
to Mulcahy et al. A co-extruded sheet may be vacuum formed. Typically, the
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WO 98/41399 PCT/US98/05108
vacuum former and surrounding metal framework are preheated to minimize
chill of the sheet. The sheet is placed on a vacuum box and mounted on the
~oLl~ side of the former or platten. Clamp frames are activated for
mechanically holding the sheet in place. A suitable heat shield, such a
5 aluminum foil, may be utilized for avoiding heating the surface at selected
locations such as other than a sink portion. The sheet is then exposed to the
thermo-forrning ovens. Top and bottom heaters may be used. During
heating, the sheet begins to sag. Once the sheet reaches its proper forming
temperature, the assembly is shuttled to a vacuum forming box where sink is
o vacuum formed in a box. The box has a plurality openings in a mold form for
drawing the sheet into mold during the forming operation. After cooling, the
resulting therrnoformed sheet is removed.
The following specific examples illustrate the present invention. The
Examples set forth in Table 4 are for comparison purposes, with
5 Formulations 4 and 6 illustrating results employing the ~lefelled rheology
modifiers of the pl~sent invention.
TABLE 4
ADDITIVES 1 Z 3 4 5 6 .7 8
: lEOM 007 . Ø0 ~ 0
C~ 30 Acr~lic Impact Mod. ~.5.0 0
V.B_-EXL 3n9 ~ 15.0
_~ ADER-'o yolefin 0 0 ~ .0 ~ ~
'CratonG:6 1 1 0 0 ~5.0,.5
. Craton G:6_2 0 7.5
~el CAl 5611 ~ 0 ' ~ .5.0 0
neL C~ P 5219 ~- 0 f 7-5
PC .~ ar ~ .3 ~ 7.1 ~7.1 n9 3 7.1~7.1 ~7.1 ~- .7
PB' 1 , ~ear :,~ .8 :,7.0 37.0 5.8 .,7.0 37.0 37.0 ., .9
Sta~I~izer. ackage ~.(3 .9 0.0 t.9 ~.9 .9 ~.9 1 9
TEST RESULTS
Melt Elasticity (% ElollgaLiOIl~ >555 >555 >555 ~5;5>555 >555 ~555 >555
CA 022S4973 l998-ll-l2
WO 98/41399 PCT/US98/05108
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Table 4 contains comparative studies of various rheology modifiers in
unfilled systems. Regardless of the modifier used, the melt elongation of the
result,ing formulation is well above 555%. Hence, these sy~ell s do not
dif~erellliate between the rheology modifiers used.
s Table 5 is directed to the comparison of rheology modifers in filled
systems.
TABLE 5
ADD~n~ 1 _ 3 4 5 6 7 8 9 10 11
~EOMu07 ~ l~ ~5.0 0.0 750 0 00 -50
~B -E~;3n 1 I- " 0 7 5 0 0
.~ ror C16_ 5 ~ " ~ ~ .5.0 _0.0
, L ne~Ar 1 0.56 .8 . .46 .46 .46 .46 .56 .56 .36 .46 ~.56
, CA ~ 131 Linear PC ~ I , .2 ~ l o
CBr~AnchedTMTC 7.2 '~ ~3.4 ~.4 43.4 ~3.4 40.9 ~0.9 45.9 ~3.4 20.92
Bas~d , , , A _ "
V~ OX 315 PBT 7. 7. 5.: .5. S. 5.:. 3. ~ 3. 6 7 5: 3
Ba C~, X7. 7. .,7. '7.~ 7. '~7. 7. 7. 7.0 7. '7.
JtAqLi".. Paclca~e .0 0 .0 .0 .0 0 0 .0 ,05 0 0
TESI RESULTS
Melt Eiastici~ (% 334 375 170 133 127 99 94 150 280 309 270
.Ior~ oll)
~ri~nalT~ckn~s (inch) 0.09 0.09 0.09 0-09 0.09 0.09 009 0.09 0.09 0 09 0 09
art Thickness 0.02 0.02 0.01 0.01 0.01 0.01 0.00 0.00 0.01 0.03(AfterTh~ v~u~ ) 3 6 3 1 1 0 6 5 6 3
0 aearly, the melt elongation drops substantially when moving from
unfilled to filled ~yslel~s. Formulations 1, 2, 9,10,11 have the highest melt
elongation and all of them are modified with Kraton G1651. To those skilled
in the art, the rheology modification of unfilled PC/P8T for enhanced blow
molding and/or thermofol~ lg is achieved by using core shell modifiers in
single phase or dual phase modification. In the ba~ sulfate filled
formulations delineated above, formulations 3 through 8 have the lowest melt
elongation, despite the fact that core shell modifiers (HEOM, MBS) are being
used. Another key test result of this studv is the vertical wall thickness afterthermoro~ g. Vertical walls in thermotormed part are the most susceptible
CA 02254973 l998-ll-l2
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to thinning. Part llu~uung is an important measure of material distribution
throughout a given part- Again, formulations 3 through 8 have the lowest
thickness retention, while those with Kraton G1651 have the highest.
Consequently, taking into account melt elongation and vertical walI thickness,
5 Kraton G1651 conldilling formulations oul~e,~lll. those containing HEOM
and/or MBS. In Table 5, the influence of high molecular weight acrylic
polymer is A~sP~se~ According to Ref. 11, these additives improve the melt
strength of unfilled PB/PBT blends.
TABLE 6
ADDllTVES 1 2 3 4 _ _ 7
PC ranc.~ed . MTC 3.43 0 1~ ,0.92
PC ~r~l~ Ied L694~ THPE 23.43 l l 0.92
LF~AN 31- nearPC ' .~3.43 "~.92 22.~ 2
K4 O Acrylic .mp. Mod. ~ .O( ~ O .OO
PE Lir e .- r ~7=0.56 .4O ,4n ',4~ .5n ~.1 ,5.7
VA' O~I ~ .5 Linear PBT . . 6 . 6 .~-6 ' .~7 -.~7 -,~ 3 J,-7
Kraton ~ 51 ' . ', . . , ~ , . . . . .
BaSQ4 ~ ' 3"' 3'
Stab:~izer Package :.O :.O .O :.O :.O :.O :.O
TEST RESULTS
.. ~lelt El sicity (% Fl.~ ) 4~ )7 809 ~2~ ~79 ~53 ''99
.'art Or ~nal Tl-i~ .. s (inch) . 9 . 19 .09 .O~ .~ 9 .09 .O9
~artTh. ~ . 80 . 29 ~.038 .0 6 . 15 .0~1 .011
(After T~
The ~ *Qn of the high molecular weight acrylic polymer clearly
~m~o~es the melt elongation as in formulations 4 through 7 compared to
formulation 3. However, they do have a deleterious effect on thickness
l~lel~liul.; thus, are detrimental to the thermoforming and/or blowmolding of
filled PC/PBT blends. The ~refelled compositions have a melt elasticity as %
elongation of greater than about 300.
CA 02254973 1998-11-12
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- 31 -
Table 7
ADDll~VES 1 2 3 4 5 6 7
LEXAN131 LinearPC 23.2 23.2 23.2 23.2 23.2 ~3.2 23.2
VALOX 315 Linear PBT 15.25 15.25 15.25 15.25 15.25 15.25 15.25
PEI Linear IV-0.56 8.50 8.50 8.50 8.50 8.50 8.50 8.50
BaSO4 37 0 37 0 37 0 37 0 37 0 37 0 37 0
Stabilizer Package 1.05 1.05 1.05 1.05 1.05 1.05 1.05
Kraton G1651 (SEBS, High MW) 15.0
Vector 2518 (SBS, Med MW) 15.0
Vector 8508D (SBS, Low MW) 15.0
Kraton G1702 (SEP, High MW) 15.0
Kraton D1102 (SBS, MedLow MW) 15.0
Kraton D1118 (SBS, Med MW) 15.0
Kraton D1184 (SBS, High MW, radial) 15.0
TESI RESULTS
Melt Elasticity (% F~ e,o~ 555 >555 183 ~555 262 214 >555
Un.~Gt.l.ed Izod impact (ft-lb/in) 43 16 14 35 17 17 31
Biaxial impact (ft-lb) 15.7 7.3 6.7 7.1 4.1 6.8 8.6
In Table 7, it is shown that A-B-A type impact modifiers desirable have
a high m-llec~ r weight in order to provide a high melt elasticity. In
addition, the type of rubbery block affects the impact of the final product,
s which is also ~npo~Lallt to its function as a useful thermoformed article.
Although those skilled in the art have relied on branched polymers
tc~ystalline and/or arnorphous)- to improve thermoformability and
blowmoldability, ~at assertion is not universal in the filled ~y~tt:ms we are
evaluating. Formulations 1 and 2 contain branched polycarlJol,ate; however,
CA 02254973 1998-11-12
WO 98/41399 PCT/US98/05108
their melt elongation is lower than that of a formulation which contains a
linear but high molecular weight polycarbonate. Moreclver, the thickness
retention of vertical walls of thermoformed parts containing branched
polycarbonate is not as good as the one with linear high molecular weight
s polycarbonate. We would rather advance the dual concept of high molecular
weight and branched as being beneficial to thermofo~ g and/or
blowmolding.
