U.S. patent application number 11/982047 was filed with the patent office on 2009-05-07 for new and novel engineering resin thermoplastic silicone vulcanizates.
Invention is credited to Veerag Yagnik Mehta, David Romenesko.
Application Number | 20090118412 11/982047 |
Document ID | / |
Family ID | 40588790 |
Filed Date | 2009-05-07 |
United States Patent
Application |
20090118412 |
Kind Code |
A1 |
Mehta; Veerag Yagnik ; et
al. |
May 7, 2009 |
New and novel engineering resin thermoplastic silicone
vulcanizates
Abstract
A method for preparing a modified thermoplastic resin by mixing
a thermoplastic resin having a t.sub.g of 95.degree. C. or greater
and having a melt processing temperature of 250.degree. C. or
greater with a silicone base comprised of 100 parts by weight of a
diorganopolysiloxane gum and having an average of at least 2
alkenyl groups per molecule in conjunction with 0 to 50 parts by
weight of a reinforcing filler along with a radical initiator. The
silicone base and this combination are dynamically vulcanized to
cure the silicone base at an elevated temperature.
Inventors: |
Mehta; Veerag Yagnik;
(Plainsboro, NJ) ; Romenesko; David; (Midland,
MI) |
Correspondence
Address: |
MCKELLAR IP LAW, PLLC
784 SOUTH POSEYVILLE ROAD
MIDLAND
MI
48640
US
|
Family ID: |
40588790 |
Appl. No.: |
11/982047 |
Filed: |
November 1, 2007 |
Current U.S.
Class: |
524/442 ;
524/588; 525/478 |
Current CPC
Class: |
C08L 83/04 20130101;
C08G 77/20 20130101; C08K 3/013 20180101 |
Class at
Publication: |
524/442 ;
524/588; 525/478 |
International
Class: |
C08K 3/36 20060101
C08K003/36; C08L 83/04 20060101 C08L083/04 |
Claims
1. A method for preparing a modified thermoplastic, said method
comprising: (I) mixing (A) a thermoplastic resin having a t.sub.g
of 95.degree. C. or greater and having a melt processing
temperature of 250.degree. C. or greater; (B) a silicone base
comprising: (i) 100 parts by weight of a diorganopolysiloxane gum
having a plasticity of at least 30 and having an average of at
least 2 alkenyl groups per molecule and (ii) 0 to 50 parts by
weight of a reinforcing filler for every 100 parts of
diorganopolysiloxane gum, wherein the weight ratio of said silicone
base to said thermoplastic resin is from 0.5:99.5 to 85:15; (C)
0.01 to 5 parts by weight of a radical initiator for every 100
parts by weight of the silicone base, and (II) dynamically
vulcanizing said silicone base at an elevated temperature.
2. A modified thermoplastic resin as claimed in claim 1 wherein the
silicone base comprises 1 to 50 parts by weight of reinforcing
filler for every 100 parts of diorganopolysiloxane gum.
3. A modified thermoplastic resin as claimed in claim 1 wherein the
silicone base comprises less than 1 part by weight of reinforcing
filler for every 100 parts of diorganopolysiloxane gum.
4. A method as claimed in claim 1 wherein the thermoplastic resin
is selected from the group consisting of thermoplastic resins
having a t.sub.g of 110.degree. C. or greater and a melt processing
temperature of 250.degree. C. or greater.
5. The method as claimed in claim 1 wherein, in addition, there is
present an adhesion additive.
6. The method as claimed in claim 5 wherein the adhesion additive
is present at 0.05 to 10 parts by weight based on the weight of the
silicone base.
7. The method as claimed in claim 1 wherein the radical initiator
is selected from the group consisting of: (i)
2,2'-azobisisobutyronitrile, (ii)
2,2'-azobis(2-methylbutyronitrile), (iii) dibenzoyl peroxide, (iv)
tert-amyl peroxyacetate, (v)
1,4-di(2-tert-butylperoxyisoproyl)benzene, monohydroperoxide, (vi)
cumyl hydroperoxide, (vii) tert-butyl hydroperoxide, (viii)
tert-amyl hydroperoxide, (ix) 1,1-d(tert-butylperoxy)cyclohexane,
(x) tert-butylperoxy isopropyl carbonate, (xi)
tert-amylperoxybenzoate, (xii) dicumylperoxide, (xiii)
2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, (xiv)
bis(1-methyl-1-phenylethyl)peroxide, (xv)
2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, (xvi) di-tert-butyl
peroxide, (xvii) .alpha.,.alpha.-dimethylbenzyl hydroperoxide,
(xviii) 3,4-dimethyl-3,4-diphenylhexane, (xix) t-butyl
hydroperoxide, (xx) t-butyl peroxy O-toluate, (xxi) cyclic peroxy
ketal, (xxii) t-butyl peroxypivalate, (xxiii) lauroyl peroxide,
(xxiv) t-amyl peroxy-2-ethylhexanoate, (xxv) vinyltris(t-butyl
peroxy)silane, (xxvi) di-t-butylperoxide, (xxvii)
2,2,4-trimethylpentyl-2-hydroperoxide, (xxviii)
2,5-bis(t-butylperoxy)-2,5-dimethylhexyne-3, (xxix)
t-butyl-peroxy-3,55-trimethylhexanoate, (xxx) cumene hydroperoxide,
(xxxi) t-butyl peroxybenzoate, (xxxii) diisopropylbenzene mono
hydroperoxide, and (xxxiii) combinations of (i) to (xxxii).
8. A method as claimed in claim 1 wherein the thermoplastic resin
is selected from the group consisting of Liquid Crystal Polymers,
Polysulfone, Polyphenylsulfone, Polyethersulfone, Polyetherketone,
Polyether-etherketone, Polyetherketoneketone,
Polyethylenenaphthalate, Polyether-block-amid,
Polyether-block-copolyamid, Polyether-block-glycol,
Polyester-block-ether, Polyester-block-glycol, Polyphenylene ether,
Polyphthalamide, Polyarylamid, Liquid crystal polymer, Polyimide,
Polyamideimide, Polyethernitrile, Polycyclohexylene-dimethylene
terephthalate, PCTA, and ASA.
9. A modified thermoplastic resin prepared by the process as
claimed in claim 1.
10. A modified thermoplastic resin prepared by the process as
claimed in claim 5.
11. A modified thermoplastic resin prepared by the process as
claimed in claim 1 wherein, in addition, there is also present a
fire retardant additive.
12. A modified thermoplastic resin prepared by the process as
claimed in claim 11 wherein the fire retardant additive is selected
from the group consisting of polydibromostyrene, copolymers of
dibromostyrene, polybromostyrene, brominated polystyrene,
tetrabromophthalate esters, tetrabromophthalate diol,
tetrabromophthalate anhydride, tetrabromobenzoate ester,
hexabromocyclododecane, tetrabromobisphenol A, tetrabromobisphenol
A bis(2,3-dibromopropyl ether), tetrabromobisphenol A bis(allyl
ether), phenoxy-terminated carbonate oligomer of
tetrabromobisphenol A, decabromodiphenylethane, decabromodiphenyl
oxide, bis-(tribromophenoxyl)ethane,
ethane-1,2-bis(pentabromophenyl), tetradecabromodiphenoxybenzene,
ethylenebistetrabromophthalimide, ammonium bromide, poly
pentabromobenzyl acrylate, brominated epoxy polymer, brominated
epoxy oligomer, brominated epoxies, triaryl phosphates
isopropylated, cresyl diphenyl phosphate, tricresyl phosphate,
trixylxl phosphate, triphenylphosphate, triaryl phosphates
butylated, resorcinol bis-(diphenyl phosphate), bisphenol A
bis(diphenyl phosphate), melamine phosphate, melamine
pyrophosphate, melamine polyphosphate, dimelamine phosphate,
melamine, melamine cyanurate, magnesium hydroxide, antimony
trioxide, red phosphorous, zinc borate, and zinc stanate.
13. A modified thermoplastic resin prepared by the process as
claimed in claim 11 wherein the fire retardant additive is selected
from non-halogenated fire retardants.
14. A modified thermoplastic resin prepared by the process as
claimed in claim 11 wherein the fire retardant additive is selected
from halogenated fire retardants.
15. A modified thermoplastic resin prepared by the process as
claimed in claim 5 wherein, in addition, there is present a fire
retardant additive.
16. A modified thermoplastic resin prepared by the process as
claimed in claim 15 wherein the fire retardant additive is selected
from the group consisting of polydibromostyrene, copolymers of
dibromostyrene, polybromostyrene, brominated polystyrene,
tetrabromophthalate esters, tetrabromophthalate diol,
tetrabromophthalate anhydride, tetrabromobenzoate ester,
hexabromocyclododecane, tetrabromobisphenol A, tetrabromobisphenol
A bis(2,3-dibromopropyl ether), tetrabromobisphenol A bis(allyl
ether), phenoxy-terminated carbonate oligomer of
tetrabromobisphenol A, decabromodiphenylethane, decabromodiphenyl
oxide, bis-(tribromophenoxyl)ethane,
ethane-1,2-bis(pentabromophenyl), tetradecabromodiphenoxybenzene,
ethylenebistetrabromophthalimide, ammonium bromide, poly
pentabromobenzyl acrylate, brominated epoxy polymer, brominated
epoxy oligomer, and brominated epoxies, triaryl phosphates
isopropylated, cresyl diphenyl phosphate, tricresyl phosphate,
trixylxl phosphate, triphenylphosphate, triaryl phosphates
butylated, resorcinol bis-(diphenyl phosphate), bisphenol A
bis(diphenyl phosphate), melamine phosphate, melamine
pyrophosphate, melamine polyphosphate, dimelamine phosphate,
melamine, melamine cyanurate, magnesium hydroxide, antimony
trioxide, red phosphorous, zinc borate, and zinc stanate.
17. A modified thermoplastic resin as claimed in claim 16 wherein
the fire retardant is non-halogenated.
18. A modified thermoplastic resin as claimed in claim 16 wherein
the fire retardant is halogenated.
19. A modified thermoplastic resin as claimed in claim 9 after it
has been vulcanized.
20. A modified thermoplastic resin as claimed in claim 10 after it
has been vulcanized.
21. A modified thermoplastic resin as claimed in claim 11 after it
has been vulcanized.
22. A modified thermoplastic resin as claimed in claim 15 after it
has been vulcanized.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to the modification of certain
engineering thermoplastics using silicone rubbers.
[0002] The advent of stable, silicone rubbers started in the U.S.
during the 1970's, but gained strength on new polydiorganosiloxane
powered rubbers during the 1990's and this has led to new plastics
modified with the modern silicone rubbers that have found use in
such things as component parts for aircraft and trains, cookware,
automobile components, machine parts, cabinetry and casing for
electronic and computer systems, designed office and home
furniture, and the like.
[0003] The provision of modern silicone rubbers came primarily from
the inventors of the inventions found in U.S. Pat. No. 5,153,238,
that issued on Oct. 6, 1992 to Bilgrien, et al; U.S. Pat. No.
3,824,208 that issued on Jul. 16, 1974 to Link et al, and U.S. Pat.
No. 5,391,594 that issued on Feb. 21, 1995 to Romenesko, et al, in
which free-flowing silicone polymer powders are taught. Said
powders have an average particle size of 1 to 1000 microns and are
prepared by mixing a polydiorganosiloxane with reinforcing silica
filler.
[0004] It is taught by Romenesko in the '594 patent that when these
powdered polymers are employed at a concentration of about 0.5 to
25 parts by weight of powder per 100 parts by weight of resin,
significant improvement in the burn character of the modified resin
is obtained such that the rate of heat release, generation of smoke
and evolution of toxic carbon monoxide gas is significantly reduced
relative to the unmodified resin.
[0005] For example, modification of thermoplastic resins has been
taught in Romenesko in U.S. Pat. No. 5,288,674 and U.S. Pat. No.
5,508,323 that issued on Apr. 16, 1996, namely, polystyrene, high
impact polystyrene, propylene, polycarbonate, polysulfone,
poly(phenylene sulfide), acrylonitrile-butadiene-styrene copolymer,
nylon, acetal, polyethylene, poly(ethylene terephthalate),
poly(butylene terephthalate), acrylate, fluoroplastics, polyesters,
phenolics, epoxies, urethanes, polyimides, melamine formaldehyde
and urea.
[0006] Romenesko et al, in U.S. Pat. No. 5,916,952 discloses the
modification of Poly(phenylene ether) resin using powered silicone
polymers. Brewer et al, in U.S. Pat. No. 6,362,288 that issued Mar.
26, 2002 discloses the silicone modification of compatibilized
polyamide resins. Chorvath et al, in U.S. Pat. No. 6,417,293 that
issued Jul. 9, 2002 discloses the silicone modification of
polyester resins.
[0007] In addition, Chorvath et al disclose thermoplastic silicone
modified elastomers (polyamide or polyester resins) using radical
cure techniques in U.S. Pat. No. 6,465,552, that issued Oct. 15,
2002 and Gross, et al in U.S. Pat. No. 5,569,958 that issued May
27, 2003 disclosed thermoplastic silicone elastomers from
compatibilized polyester resins.
[0008] Further, Brewer, et al in U.S. Pat. No. 6,649,704 that
issued on Nov. 18, 2003 disclose thermoplastic silicone elastomers
from compatibilized polyamide resins and still further, Gornowicz
et al, in U.S. Pat. No. 6,759,487 that issued on Jul. 6, 2004
disclose thermoplastic polyurethane silicone elastomers.
[0009] These patents teach modification of certain polymers that
have t.sub.g's below about 90.degree. C. and processing
temperatures of less than 200.degree. C., as these are the polymers
that have fairly low complexity of handling. Polymers having
t.sub.g's above about 95.degree. C. along with melt processing
temperatures at 250.degree. C. or above have not been taught in the
prior art nor have the benefits of such compositions been disclosed
in the prior art.
THE INVENTION
[0010] Thus, what is disclosed and claimed herein is a method for
preparing a modified thermoplastic, said method comprising mixing a
thermoplastic resin selected from the group consisting of (i) a
thermoplastic resin having a t.sub.g of 95.degree. C. or greater
and having a melt processing temperature of 250.degree. C. or
greater with a silicone base comprised of 100 parts by weight of a
diorganopolysiloxane gum having a plasticity of at least 30 and
having an average of at least 2 alkenyl groups per molecule in
conjunction with 0 to 50 parts by weight of a reinforcing filler,
wherein the weight ratio of said silicone base to said
thermoplastic resin is from 0.5:99.5 to 85:15.
[0011] In addition, there is present 0.01 to 5 parts by weight of a
radical initiator for every 100 parts by weight of the silicone
base, and this combination is dynamically vulcanized to cure the
silicone base at an elevated temperature.
[0012] "Elevated temperature" for purposes of this invention is at
least the melt processing temperature of the thermoplastic
resin.
[0013] Preferred thermoplastic resins for use in this method are
those having a t.sub.g of 95.degree. C. or greater and a melt
processing temperature of 250.degree. C. or greater. More preferred
are those thermoplastic resins having a t.sub.g of 110.degree. C.
or greater.
[0014] The preparation of the diorganopolysiloxane bases useful in
this invention can be found in U.S. Pat. No. 5,508,323, among
others, and the disclosure with regard to this preparation is
hereby incorporated by reference for what it teaches about such
silicone base preparation.
[0015] Also useful in this invention are adhesion additives (also
known as coupling agents). Such additives and how they are used are
well known in the art. For example, in the '323 patent there is
disclosed at column 6, beginning at line 16, a full disclosure of
what these materials are and that information is incorporated
herein by reference for what it teaches about such adhesion
additives and how they are used.
[0016] Preferred for this invention is the use of a level of
adhesion additive of about 0.5 to about 15 parts by weight for each
100 parts by weight of said silicone rubber powder, the addition
being preferably carried out after the polydiorganosiloxane and
treated silica filler have been mixed.
[0017] The silicas that are useful in this invention are finely
divided fillers derived from fumed or precipitated forms, or from
silica aerogels. These fillers are well known and are typically
characterized by surface areas greater than about 50 m.sup.2/gram.
The fumed form of silica is the preferred reinforcing filler based
on its availability, cost, and high surface area, which can be as
high as 900 m.sup.2/gram, but preferably has a surface area of 50
to 400 m.sup.2/gram. These silicas are also very easy to
manufacture and handle. It is contemplated within the scope of this
invention to use silicone formulations that do not contain silica
filler, or that contain very small amounts of silica filler. Thus,
amounts of silica ranging from just above zero parts per 100 parts
of the base polymer up to less than 1 part of silica filler can be
used.
[0018] For purposes of this invention, the silica filler, if used,
is preferably treated by reaction with a liquid organosilicon
compound containing silanol groups or hydrolyzable precursors of
silanol groups. Compounds that can be used as filler treating
agents, also referred to as anti-creping agents, include such
components as low molecular weight liquid hydroxy- or
alkoxy-terminated polydiorganosiloxanes, hexaorganodisiloxanes and
hexaorganodisilazanes. The silicon-bonded hydrocarbon radicals in
or on a portion of the filler treating agent can contain
substituents such as carbon to carbon double bonds. It is preferred
that the treating compound is an oligomeric hydroxy-terminated
polydimethyl-siloxane having an average degree of polymerization
(DP) of about 2 to about 100. A highly preferred treating fluid of
this type has a DP of about 2 to 10.
[0019] The silica filler used in the present method is preferably
reacted with about 10 to about 45 weight percent, based on filler
weight, of the filler treating agent prior to being blended with
the polydiorganosiloxane to form the silicone rubber. Treatment of
the filler can be carried out in the same mixing vessel used to
prepare the silicone rubber. The silica or other reinforcing filler
is typically maintained at a temperature greater than about
100.degree. C. to about 200.degree. C. during the treatment
process. Alternatively, the filler can be treated while it is being
blended with the high consistency polydiorgano-siloxane during
preparation of the silicone rubber.
[0020] According to the methods of this invention, the
thermoplastic is prepared by thoroughly dispersing the silicone
base in the thermoplastic resin and then dynamically vulcanizing
the silicone base using either of the methods set forth herein.
[0021] For purposes of this invention wherein the method is that of
mixing a thermoplastic resin with a silicone gum comprised of an
alkenyl-functional silicone that is cured by free radical
catalysis, the weight ratio of silicone base to the thermoplastic
resin can range from 0.5:99.5 to 85:15, and no hydrogen-containing
polysiloxanes need be added.
[0022] The radical initiators useful in this invention are any
compounds capable of providing free radicals for the subsequent
vulcanization of the silicone base. Such radical initiators can be
exemplified and selected from the group consisting of (i)
2,2'-azobisisobutyronitrile, (ii)
2,2'-azobis(2-methylbutyronitrile), (iii) dibenzoyl peroxide, (iv)
tert-amyl peroxyacetate, (v)
1,4-di(2-tert-butylperoxyisoproyl)benzene, monohydroperoxide, (vi)
cumyl hydroperoxide, (vii) tert-butyl hydroperoxide, (viii)
tert-amyl hydroperoxide, (ix) 1,1-d(tert-butylperoxy)cyclohexane,
(x) tert-butylperoxy isopropyl carbonate, (xi) tert-amyl
peroxybenzoate, (xii) dicumyl peroxide, (xiii)
2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, (xiv)
bis(1-methyl-1-phenylethyl)peroxide, (xv)
2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3, (xvi) di-tert-butyl
peroxide, (xvii) .alpha.,.alpha.-dimethylbenzyl hydroperoxide,
(xviii) 3,4-dimethyl-3,4-diphenylhexane, (xix) t-butyl
hydroperoxide, (xx) t-butyl peroxy O-toluate, (xxi) cyclic peroxy
ketal, (xxii) t-butyl peroxypivalate, (xxiii) lauroyl peroxide,
(xxiv) t-amyl peroxy-2-ethylhexanoate, (xxv) vinyltris(t-butyl
peroxy)silane, (xxvi) di-t-butylperoxide, (xxvii)
2,2,4-trimethylpentyl-2-hydroperoxide, (xxviii)
2,5-bis(t-butylperoxy)-2,5-dimethylhexyne-3, (xxix)
t-butyl-peroxy-3,55-trimethylhexanoate, (xxx) cumene hydroperoxide,
(xxxi) t-butyl peroxybenzoate, (xxxii) diisopropylbenzene mono
hydroperoxide, and (xxxiii) combinations of (i) to (xxxii).
[0023] This initiator is used in an amount sufficient to cure
diorganopolysiloxane (B) and this amount can be optimized for a
given system by those skilled in the art using routine
experimentation. When the amount is too low, insufficient
crosslinking takes place and mechanical properties suffer
accordingly. Optimum performance can be readily determined by a few
simple experiments for the system under consideration. Moreover,
information can be obtained from the manufacturer with regard to
the performance (half-life) of the initiator.
[0024] The initiator is preferably added in the amount of 0.01 to 5
parts by weight for every 100 parts by weight of the silicone base
in method 1. More preferred is an amount of 0.05 to 4 parts for
every 100 parts by weight of the silicone base.
[0025] The thermoplastics that are useful in this invention are
those that have a t.sub.g of 95.degree. C. or greater and a melt
processing temperature of 250.degree. C. or greater, and as long as
these parameters are satisfied, then the thermoplastic is
contemplated within the scope of this invention.
[0026] Such resins can be exemplified by Liquid Crystal Polymers,
Polysulfone, Polyphenylsulfone, Polyethersulfone, Polyetherketone,
Polyether-etherketone, Polyetherketoneketone,
Polyethylenenaphthalate, Polyether-block-amid,
Polyether-block-copolyamid, Polyether-block-glycol,
Polyester-block-ether, Polyester-block-glycol, Polyphenylene ether,
Polyphthalamide, Polyarylamid, Liquid crystal polymer, Polyimide,
Polyamideimide, Polyethernitrile, Polycyclohexylene-dimethylene
terephthalate, PCTA, and ASA.
[0027] The mixing is carried out in a twin-screw extruder wherein
the resin is fed to the extruder through a hopper and the other
components are introduced into the extruder along the way, with the
radical catalyst preferably being added with the silicone rubber,
or separately fed in at a location away from the silicone rubber
feed. In a variation of this procedure, the non-reinforcing filler
is introduced along with the resin through the hopper. Silicone
reinforcing filler may be added after silicone gum is pumped into
the extruder. Preferably, the extruder size is sufficient to
accomplish the mixing and curing in one pass.
[0028] Also contemplated within the scope of this invention is the
use of fire retardant additives to provide fire retardancy to the
compositions of this invention. Traditional fire retardants can be
used herein and can be selected from the group consisting of
halogenated varieties such as polydibromostyrene, copolymers of
dibromostyrene, polybromostyrene, brominated polystyrene,
tetrabromophthalate esters, tetrabromophthalate diol,
tetrabromophthalate anhydride, tetrabromobenzoate ester,
hexabromocyclododecane, tetrabromobisphenol A, tetrabromobisphenol
A bis(2,3-dibromopropyl ether), tetrabromobisphenol A bis(allyl
ether), phenoxy-terminated carbonate oligomer of
tetrabromobisphenol A, decabromodiphenylethane, decabromodiphenyl
oxide, bis-(tribromophenoxyl)ethane,
ethane-1,2-bis(pentabromophenyl), tetradecabromodiphenoxybenzene,
ethylenebistetrabromophthalimide, ammonium bromide, poly
pentabromobenzyl acrylate, brominated epoxy polymer, brominated
epoxy oligomer, and brominated epoxies. Other, non-halogen
varieties can be selected from such materials as triaryl phosphates
isopropylated, cresyl diphenyl phosphate, tricresyl phosphate,
trixylxl phosphate, triphenylphosphate, triaryl phosphates
butylated, resorcinol bis-(diphenyl phosphate), bisphenol A
bis(diphenyl phosphate), melamine phosphate, melamine
pyrophosphate, melamine polyphosphate, dimelamine phosphate,
melamine, melamine cyanurate, magnesium hydroxide, antimony
trioxide, red phosphorous, zinc borate, and zinc stanate.
[0029] It is known by those skilled in the art with regard to how
much of the fire retardant can be added to give the required
effect. Those amounts are also useful herein.
EXAMPLES
[0030] The extruder used in these examples was a Werner &
Pfleiderer ZSK25, a 25 mm co-rotating twin screw extruder. All
materials percentages are given in weight %. Test specimens of Type
A tensile bars and 1/8'' flex bars were prepared by injection
molding on a Boy 30 ton injection molding press. Testing of the
tensile bars was done in accordance with ASTM D792.
[0031] The following materials were employed in the examples set
forth herein.
[0032] BASE 1 is a silicone rubber base produced by CRI-SIL,
Silicone Technologies, LLC, Biddeford, Me. and is designated as FG
0733 BASE. This material is a stabilized base that is peroxide
curable to 50 Durometer. Into this base was blended 4 parts per
hundred of tert-Butyl hydroperoxide that is marketed by Akzo Nobel
Polymer Chemicals, Burt, N.Y., under the name of Triganox A-W70.
All bases are pumped into the extruder in the first zone for all
experiments.
[0033] BASE 2 is the same as BASE 1 with only 2 parts of a
tert-Butyl hydroperoxide. BASE 2 was created by blending a base
similar to BASE 1 but without the peroxide in it at a 50/50 BASE 1
ratio.
[0034] BASE 3 is the same as BASE 1 with only 1 part of tert-Butyl
hydroperoxide. BASE 3 was created by blending a base similar to
BASE 1 but without the peroxide in it at a 75/25 BASE 1 ratio.
[0035] BASE 4 is the same as BASE 1 with only 0.4 parts of a
tert-Butyl hydroperoxide. BASE 4 was created by blending a base
similar to BASE 1 but without the peroxide in it at a 90/10 BASE 1
ratio.
[0036] Filler 1 was Wollastonite marketed by NYCO Minerals Inc.,
Willisboro, N.Y., as NYAD G.
[0037] PDMS 1-BASE 1 to 4 was made from FG 0733 GUM, being a
dimethylvinylsiloxy-terminated dimethyl-methylvinyl siloxane
copolymer gum having a Williams plasticity of 140 to 165.
[0038] PPE 1 is a poly(phenylene ether) marketed by Asahi Kasai
Plastics, as Xyron SA201A.
[0039] PPE 2 is a poly(polyphenylene ether) marketed by Asahi Kasai
Plastics, as Xyron SA202A.
[0040] PES 1 is a hydroxyl terminated poly(ether sulfone) marked by
Gharda Polymers USA, Newtown, Pa. under the product name Gafone
3600RP.
[0041] PPS 1 is an acid functional poly(phenylene sulfide) marketed
by Ticona as Fortran SF3001-0214B1.
Example 1
[0042] In this example, Base 1 (18.5%) PPE 2 (71.4%) and Filler 1
(10.1%) were blended using a commercial extruder. The extruder
temperatures were set in various zones starting the beginning of
the extruder and extending to the right, to 250.degree.
C./250/250/275/275/275/275/275/275/275/275/280.degree. C. The
extruder RPMs were set to 400 and a rate of 18.5 lb/hr was
targeted. The resulting material had a tensile at break of 7550
Psi, elongation at break of 11% and a flex modulus of 290,000
psi.
Example 2
[0043] In this example, BASE 1 (20.5%), PPE 2 at (59.7%) and Filler
1 at (19.8%) were blended using a commercial extruder. The extruder
temperatures were set in the various zones from left to right to
250.degree. C./250/250/275/275/275/275/275/275/275/275/280.degree.
C. The extruder RPMs were set to 400 and a rate of 7.3 lb/hr was
targeted. The resulting material had a tensile at break of 4490
psi, elongation at break of 6.1% and a flex modulus of 200,000
psi.
Example 3
[0044] In this example, BASE 1 (19.4%) and PES 1 (80.6%) were
blended using a commercial extruder. The extruder temperatures were
set in the various zones from left to right to 150.degree.
C./250/250/275/275/275/275/275/275/275/275/280.degree. C. The
extruder RPMs were set to 400 and a rate of 18.6 lb/hr was
targeted. The resulting material had a tensile at break of 6550
psi, elongation at break of 5.8% and a flex modulus of 293,000
psi.
Example 4
[0045] In this example BASE 4 (27.15%) and PPS 1 (72.85%) were
blended using a commercial extruder. The extruder temperatures were
set in the various zones from left to right to 120.degree.
C./275/275/275/275/275/275/275/275/275/275/280.degree. C. The
extruder RPMs were set to 500 and a rate of 23.5 lb/hr was
targeted. The resulting material had a tensile at break of 6000
psi, elongation at break of 18% and a flex modulus of 288,000
psi.
Example 5
[0046] This example is provided to show the influence of the
silicone base in the modified thermoplastic resins. Formulations
are in Table I and the results are in Table II.
TABLE-US-00001 TABLE I Formulation Crisil Sil Base/ % Xyron Number
1% peroxide and type 1 10% 90-SA201A 2 15% 85-SA201A 3 20%
80-SA201A 4 30% 70-SA201A 5 40% 60-SA201A 6 50% 50-SA201A 7 10%
90-SA202A 8 15% 85-SA202A 9 20% 80-SA202A 10 30% 70-SA202A 11 40%
60-SA202A 12 50% 50-SA202A
TABLE-US-00002 TABLE II strain Stress Form Stress Strain Stress at
Modulus *Def. No. at yield at yield at break break Psi Psi Impact 1
9746 9.7 7196 16.0 319394 11330 3.19 2 8330 3.6 3143 8.5 290601
9847 2.58 3 -- -- 5251 5.7 199117 4528 2.26 4 -- -- 3393 4.8 121922
2576 1.89 5 -- -- 2950 4.8 107464 2553 1.60 6 no data -- -- -- no
data -- no data 7 9757 9.9 7554 52.4 307108 10862 2.43 8 9189 10.0
7086 50.6 301881 10657 2.52 9 7418 9.6 7111 12.3 271191 8880 2.15
10 5535 8.5 5234 8.5 209173 -1 1.70 11 4547 8.7 4503 9.6 176918 924
1.96 *Deflection
Example 6
[0047] This example discloses the use of fire retardants in the
modified thermoplastic resins. Table I shows the formulations and
Table II shows the results.
[0048] The method of testing that was used consisted of hanging a
specimen bar about 8 inches above a piece of cotton wool. A hand
held propane torch was used as the flame source and the flame was
applied to the bottom part of the sample for 10 seconds. After 10
seconds, the flame was removed, and the sample was observed to
determine if it sustained a flame. If it was burning, the time was
observed before the flames extinguished. If the sample burned for
more than 10 seconds, it was considered a failure. If the sample
extinguished itself before 10 seconds, then the flame was reapplied
to the sample for 10 additional seconds, and the observation and
results was repeated. This process was repeated for a maximum of
three 10 second burns. If during or after the flame is applied, the
sample drips or separates away from the remainder of the hanging
sample, the drip should not ignite the cotton. If it does ignite
the cotton, it is considered a failure. After the three flame
applications, and assuming the flame was extinguished each time,
the samples were assessed for char formation. The assessment of
char formation and density is a very subjective test, and
comparative between the samples, and not against any standard. All
samples that did not fail had substantial hard char formation.
[0049] It should be noted that this test is more severe than the
UL94-5V burn rate test in that the flame used in that test is a
Bunsen burner having a flame of approximately 5 inches and an inner
core flame of 11/2 inches while the propane torch of this test has
a flame of approximately 21/2 inches and an inner core flame of
about 3/4 of an inch, making the flame impact much hotter. Table
III shows the results of the flame testing.
TABLE-US-00003 TABLE I Formulation Crisil Sil Base/ % Xyron Number
1% peroxide and type % Nyad G % FR* 1 7.50% 78.30-SA201A 2.50
11.70% 2 11.25% 73.95-SA201A 3.75 11.05% 3 15.00% 69.60-SA201A 5.00
10.40% 4 22.50% 60.90-SA201A 7.50 9.10% 5 30.00% 52.20-SA201A 10.00
7.80% 6 37.50% 43.50-SA201A 12.50 6.50% 7 7.50% 78.30-SA202A 2.50
11.70% 8 11.25% 73.95-SA202A 3.75 11.05% 9 15.00% 69.60-SA202A 5.00
10.40% 10 22.50% 60.90-SA202A 7.50 9.10% 11 30.00% 52.20-SA202A
10.00 7.80% 12 37.50% 43.50-SA202A 12.50 6.50% FR = Fire Retardant
= NcendX P-30 flame retardant manufactured by Albemarle
Corporation, Baton Rouge, Louisiana.
TABLE-US-00004 TABLE II Stress strain Form Stress Strain at at
Modulus Stress No. at yield at yield break break Psi *Def. Psi
Impact 1 10451 9.3 9866 12.6 349891 13289 1.11 2 9745 8.4 8968 7.6
342472 11614 1.45 3 -- -- 6516 6.1 310457 10323 1.29 4 6299 8.3
6269 8.5 250807 8935 1.10 5 5708 7.8 5677 8.2 258293 439 1.26 6 --
-- 4615 6.4 244432 -- 1.08 7 nd nd nd nd nd nd nd 8 nd nd nd nd nd
nd nd 9 9845 8.8 9795 8.9 351733 -- .825 10 9069 8.6 9094 8.9
336088 -- .860 11 -- -- 4729 5.4 316464 -- .948 12 6779 8.5 6699
8.4 283072 -- .838 13 -- -- 5436 7.3 264780 -- .772 14 -- -- 4320
5.9 235696 -- .754
TABLE-US-00005 TABLE III Time After 10 sec. Form Burn In Seconds
No. 1.sup.st Burn 2.sup.nd Burn 3.sup.rd Burn 1 1 3 2 2 1.5 3 2 3 2
3 3 4 2 3 4 5 2 3 3 6 2 3 4 9 1 3 2 10 1 3 2 11 2 3 3 12 2 3 4 13 2
3 4 14 2 3 3
* * * * *