U.S. patent number RE31,577 [Application Number 06/506,558] was granted by the patent office on 1984-05-01 for reactive terminally unsaturated liquid polymers in unsaturated polyesters.
This patent grant is currently assigned to The B. F. Goodrich Company. Invention is credited to Changkiu K. Riew.
United States Patent |
RE31,577 |
Riew |
May 1, 1984 |
Reactive terminally unsaturated liquid polymers in unsaturated
polyesters
Abstract
Terminally unsaturated liquid epihalohydrin polymers are
produced by polymerizing at least one epihalohydrin using acrylic
acid or methacrylic acid as a modifier. The polymerization is
conducted in the presence of a catalytic amount of a trialkyl
oxonium salt of an HMF.sub.6 acid wherein M is an element selected
from the group consisting of phosphorus, arsenic and antimony. The
polymers are useful as tougheners for unsaturated polyester resin
systems.
Inventors: |
Riew; Changkiu K. (Akron,
OH) |
Assignee: |
The B. F. Goodrich Company
(Akron, OH)
|
Family
ID: |
26754191 |
Appl.
No.: |
06/506,558 |
Filed: |
June 21, 1983 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
73160 |
Sep 6, 1979 |
4256904 |
|
|
Reissue of: |
159088 |
Jun 13, 1980 |
04274994 |
Jun 23, 1981 |
|
|
Current U.S.
Class: |
523/514; 525/166;
525/168; 525/171; 525/27; 525/39; 525/44; 525/48 |
Current CPC
Class: |
C08F
299/0478 (20130101); C08G 65/2615 (20130101); C08G
65/24 (20130101); C08G 65/105 (20130101) |
Current International
Class: |
C08F
299/04 (20060101); C08G 65/26 (20060101); C08F
299/00 (20060101); C08G 65/24 (20060101); C08G
65/10 (20060101); C08G 65/00 (20060101); C08L
067/06 () |
Field of
Search: |
;523/514
;525/27,39,44,48,166,171,168 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nielsen; Earl A.
Attorney, Agent or Firm: Lobo; Alfred D. Shust; Nestor W.
Csontos; Alan A.
Parent Case Text
This is a .Iadd.reissue of Patent No. 4,274,994, issued June 23,
1981, Ser. No. 159,088, filed June 13, 1980, which is a
.Iaddend.division, of application Ser. No. 73,160, filed Sept. 6,
1979, .Iadd., now Patent No. 4,256,904.Iaddend..
Claims
I claim:
1. An unsaturated polyester molding composition comprising:
(a) An unsaturated polyester resin,
(b) A polymerizable vinyl monomer, and
(c) From about 2 to about 30 weight parts of a terminally
unsaturated liquid epihalohydrin polymer having the formula
##STR6## wherein Y is hydrogen or methyl, and G is a polymeric
backbone comprising polymerized units of at least one
epihalohydrin.
2. A composition of claim 1 wherein the epihalohydrin polymer has a
number average molecular weight from about 100 to about
100,000.
3. A composition of claim 2 containing a catalytic amount of a
catalyst.
4. A composition of claim 3 wherein said catalyst is selected from
the group consisting of benzoyl peroxide, tertiary butyl
perbenzoate, cyclohexanone peroxide, tertiary butyl peroxide,
tertiary butyl peroctoate, azobisisobutyronitrile and cumene
hydroperoxide.
5. A composition of claim 4 containing fiber reinforcement.
6. A composition of claim 5 wherein the level of said fibers is
from about 5 to about 70 weight percent by weight of the total
composition weight.
7. A composition of claim 6 containing a thermoplastic low profile
additive and as a thickening agent an oxide or hydroxide of
magnesium or calcium.
8. A composition of claim 7 wherein the low profile additive is a
thermoplastic homopolymer of a vinylidene monomer containing from 2
to 12 carbon atoms.
9. A composition of claim 21 wherein epihalohydrin is
epichlorohydrin, and said polymerizable monomer is styrene.
10. A composition of claim 9 wherein said backbone G also contains
polymerized units of at least one other epoxide having the formula
##STR7## wherein each R is selected from the group consisting of
hydrogen, alkyl, alkoxyalkyl, phenyl and unsaturated radicals, but
at least one R is hydrogen.
11. A composition of claim 10 wherein said other epoxide is an
alkylene oxide.
12. A composition of claim 11 wherein said alkylene oxide is
ethylene oxide or propylene oxide.
13. A composition of claim 12 wherein Y is hydrogen.
Description
BACKGROUND OF THE INVENTION
The prior art teaches preparation of trialkyl oxonium salts of
HMF.sub.6 wherein M is an element selected from the group
consisting of phosphorous, arsenic and antimony (U.S. Pat. No.
3,585,227) that are useful as catalysts for preparation of rubbery
polyepihalohydrins (U.S. Pat. No. 3,850,857); and, when water or a
glycol is employed as a reactant, liquid hydroxyl-terminated
epihalohydrin polymers (U.S. Pat. No. 3,850,856).
Co-polymerizations of epichlorohydrin with glycidyl esters of
ethylenically unsaturated acids or ethylenically unsaturated
epoxides to produce solid elastomers which contain vinyl
unsaturation have been disclosed previously in U.S. Pat. Nos.
3,285,870 and 3,158,591. New polymers are desired having an
epihalohydrin polymeric backbone but different reactive end
groups.
SUMMARY OF THE INVENTION
Terminally unsaturated liquid epihalohydrin polymers having the
formula ##STR1## wherein Y is hydrogen or alkyl, X is zero,
alkylene or arylene and G is a polymeric backbone comprising units
of at least one epihalohydrin, optionally together with at least
one other epoxide. Polymers are prepared by polymerization of an
epihalohydrin in the presence of an unsaturated carboxylic acid
using a catalytic amount of a trialkyl oxonium salt of an HMF.sub.6
acid wherein M is an element selected from the group consisting of
phosphorous, arsenic and antimony. Unsaturated polyester molding
compositions containing these terminally unsaturated polymers have
improved toughness when suitably cured, without significant adverse
effects on other important properties such as cure rate and
strength.
DETAILED DESCRIPTION
This invention discloses novel vinyl terminated polyepihalohydrins
of low molecular weight. The polymers may be used as a toughener
for unsaturated polyester resin systems.
The prior art described in U.S. Pat. No. 3,850,856 is a process of
manufacturing hydroxyl-terminated poly(epichlorohydrins) by
cationic polymerization using triethyloxonium hexafluorophosphate
(TEOP) as the initiator and in the presence of a controlled amount
of water or ethylene glycol.
The invention disclosed herein is a process which differs from the
prior art in that the products of this invention are low molecular
weight poly(epichlorohydrins) which are not only viscous liquids at
room temperature but also contain terminal vinyl groups prepared by
polymerizing an epihalohydrin in the presence of a trialkyl oxonium
salt of a hexafluorometallic acid catalyst and a controlled amount
of an unsaturated carboxylic acid.
The terminally unsaturated liquid epihalohydrin polymers have the
formula ##STR2## wherein Y is hydrogen or methyl and x is zero (o)
an alkylene radical containing 0-10, preferably 0-3 carbon atoms or
arylene as phenylene or naphthylene. G is a polymeric backbone
comprising units of at least one epihalohydrin, optionally together
with at least one other epoxide such as those having the formula
##STR3## wherein all R radicals are selected from the group
consisting of hydrogen, alkyl and alkenyl radicals containing 1 to
10 carbon atoms, more preferably 1 to 5 carbon atoms, alkoxy-alkyl
radicals containing 2 to 10 carbon atoms more preferably 2 to 6
carbon atoms, phenoxyalkyl radicals wherein the alkyl group
contains 1 to 6 carbon atoms, and phenyl radicals, and at least one
of said R radicals is hydrogen. Even more preferably all R radicals
are selected from the group consisting of hydrogen and alkyl
radicals containing 1 to 3 carbon atoms, and at least one of said R
radicals is hydrogen. Examples of suitable epoxides include
alkylene oxides such as ethylene oxide, propylene oxide, cis- and
trans- but preferably cis-butene-2-oxide, butene-1-epoxide, cis-
and trans-pentene-2-oxide, cis- and trans-hexene-2-oxide, cis- and
trans-hexene-3-oxide, and the like; phenyl alkylene oxides such as
styrene oxide and the like; and glycidyl ethers such as methyl
glycidyl ether, ethyl glycidyl ether, methylethylglycidyl ether,
butyl glycidyl ether, phenyl glycidyl ether, and the like, normally
in amounts up to 50% by weight of these epoxy monomers. Excellent
results are obtained with ethylene oxide and propylene oxide. Also,
unsaturated glycidyl ethers of the general formula ##STR4## where R
is an ethylenically unsaturated radical such as vinyl, allyl,
alkenyl and the like. Typical glycidyl ethers include vinyl
glycidyl ether, allyl glycidyl ether, butenyl glycidyl ether,
4-vinylcyclohexyl glycidyl ether, abietylglycidyl ether,
cyclohexeneylmethyl glycidyl ether, o-allyl-phenyl glycidyl ether
in amounts up to about 20 weight percent of the epoxy monomers.
While the unsaturated glycidyl ethers are generally preferred,
useful copolymers may also be made with monoepoxides of dienes or
polyenes such as butadiene, methylene monoxide, chloroprene
monoxide, 3,4-epoxy-1-pentene, 4,6-epoxy-2-hexene,
2-epoxy-5,9-cyclododecadiene, and the like.
Alkylene oxides are preferred "other epoxides," with ethylene
oxide, propylene oxide, glycidyl acrylate and methacrylate and
allyl glycidyl ether being especially useful. Preferred
epihalohydrins are epichlorohydrin and epibromohydrin, with
epichlorohydrin being especially useful.
The terminally unsaturated epihalohydrin liquid polymers of the
present invention are prepared using the catalyst described in U.S.
Pat. Nos. 3,585,227, 3,850,856 and 3,850,857 but in the substantial
absence of water or glycol. The catalyst is a trialkyl oxonium salt
of a hexfluorometallic acid, HMF.sub.6 wherein M is an element
selected from the group consisting of phosphorus, arsenic and
antimony, such acids being HPF.sub.6, HAsF.sub.6, and HSbF.sub.6. A
particularly economical method of preparing these catalysts is
described in the aforementioned U.S. Pat. No. 3,585,227. This
process entails mixing a solution of an HMF.sub.6 acid with a
dialkyl ether and an epoxide selected from the group consisting of
alkylene oxides and halogen-substituted alkylene oxides. The ether
employed in said process determines the alkyl groups present in the
oxonium salt and one will select the ether for this purpose.
Suitable dialkyl ethers include dimethyl ether, methyl ethyl ether,
diethyl ether, dipropyl ether, ethyl propyl ether, di-n-butyl
ether, di-n-amyl ether dihexyl ether, di-2-ethyl-hexyl ether and
the like.
A preferred catalyst for use in the present process is
triethyloxonium hexafluorophosphate (TEOP)
which is an easily handled, stable crystalline salt. The amount of
catalyst typically will vary from about 0.001 to about 1.0 weight
part, for example, 0.02 to 0.1, per 100 weight parts of epoxide
monomer being polymerized. The preferred catalyst amount is from
about 0.004 to about 0.025 weight part per 100 weight parts of
epoxide monomer. Of course, the exact amount of catalyst in any
particular polymerization recipe will depend upon the specific
HFM.sub.6 salt used, as well as the mode of polymerization,
reaction temperature, and the like.
The vinyl-containing liquid polyepihalohydrins prepared by the
cationic polymerization of epihalohydrins using TEOP as the
initiator contain with the controlled amount of a chain transfer
agent selected from unsaturated carboxylic acids. The amount of
acid controls the vinyl content, the molecular weight and viscosity
of the product. Usually, the amount employed can be in the range of
0.01 to 10 parts in weight based on one hundred parts of monomers
employed. The preferred range is 0.01 to 5 parts.
The polymerization is conducted in the presence of unsaturated
carboxylic acids, normally vinyl terminated, containing 3-18 carbon
atoms, more usually 3-10, for example, acrylic acid, methacrylic
acid, ethacrylic acid, vinyl benzoic acid, vinyl naphthoic acid,
itaconic acid and the like are useful in the present process as a
chain transfer agent, ideally resulting in a terminal unsaturated
group of the formula ##STR5## wherein Y is H or alkyl and x is
zero, alkylene or acrylene, at each end of the polymer chain. The
actual number of terminal unsaturated groups may vary from about 1
to about 2 per polymer molecule. The amount of acrylic acid or
methacrylic acid typically will vary from about 0.01 weight part to
about 10 weight parts per 100 weight parts of epoxide monomer, more
preferably from about 0.1 to about 5 per 100 weight parts of
epoxide monomers.
The reaction may be carried out at a reaction temperature of
20.degree. to 100.degree. C., preferably in the range of 30.degree.
to 80.degree. C. The initiator, TEOP, which is usually dissolved in
methylene chloride may be charged to the reactor with one shot, or
incrementally batched in, or preferably, metered in at a constant
rate over a span of one to 15 hours. The amount of initiator, TEOP,
used in the reaction affects the reaction conversion and the yield
of product per unit weight of initiator employed.
A typical polymerization technique is as follows. The epoxide
monomer(s) and acrylic acid or methacrylic acid are charged to a
stirred reactor and preheated to about 40.degree. C. to 80.degree.
C. (although reaction temperature may vary from about 0.degree. C.
to about 110.degree. C.). The catalyst is added neat or as a
solution in a solvent such as methylene chloride. The catalyst may
be added all at once but is preferably added incrementally or
continuously during polymerization to enable better control of
reaction rate and temperature. The acrylic acid or methacrylic acid
may also be incrementally batched in or metered in. An inert
polymerization solvent or diluent is not required but may be useful
to promote efficient mixing and temperature control (the reaction
is exothermic). Suitable solvents and diluents include benzene,
toluene, hexane, cyclohexane, chlorobenzene and carbon
tetrachloride. Reaction time normally may be from about one to 20
hours or more. Reaction pressure is typically autogeneous, but
superatmospheric pressures up to 10 atmospheres or more may be
employed with the more volatile monomers and solvents/diluents. The
reaction may be shortstopped at the desired time using a solution
of ammonium hydroxide in isopropanol. If a solvent or diluent has
been used, the polymer may be recovered by methods known to the
art, such as in a thin film evaporator. Any antioxidant such as
tetrabis[methylene(3,5-di-tert-butyl-4-hydroxycinnamate)]methane
and an inhibitor such as tert-butyl catechol, methyl hydroquinone,
or phenothiazine may be added after shortstopping.
The terminally unsaturated epihalohydrin polymers produced by the
above method will vary from fluid liquids to thick semi-solids
having typical number average molecular weights (M.sub.n) from
about 100 to about 100,000. The polymers of this invention will
typically have Brookfield viscosity ranging from about 10 Pa.S to
about 16,000 Pa.s at 27.degree. C.
These characteristic features enable this material to be
particularly useful as a toughener for unsaturated polyester resins
system because it co-cures with the unsaturated polyester in
addition to its easy handling, and has good compatibility with the
resin system.
The vinyl terminated poly(epihalohydrin)s of this invention will be
particularly useful in the systems disclosed and described in U.S.
Pat. No. 4,101,604, wherein the molding compositions contain an
unsaturated polyester resin, the vinyl terminated polyepihalohydrin
of this invention, a polymerizable monomer and optionally,
reinforcing fibers, catalyst thermoplastic polymers, thickening
agents and fillers as disclosed in said patent. The polymers of
this invention also find use in castable compositions used as
caulks, sealants and the like, as disclosed in U.S. Pat. No.
3,925,330, wherein the compositions comprise the vinyl terminated
polyepihalohydrin of this invention, polymerizable vinyl monomer,
and a free radical catalyst system. These materials will also find
use in forming co-curing compositions with amine terminated liquid
polymers of the nature described in U.S. Pat. No. 4,058,657.
Further uses including a particular application of these vinyl
terminated polyepihalohydrin will be in the preparation of printing
plates described in U.S. Pat. No. 4,137,081, wherein the
compositions comprise the vinyl terminated polyepihalohydrin of
this invention, at least one ethylenically unsaturated monomer, and
a photoinitiator.
The following examples illustrate the present invention more
fully.
EXAMPLE 1
To prepare the terminally unsaturated epihalohydrin polymer, a
75-gallon Jacketed reactor, 492.5 pounds (223.6 Kg) of
epichlorohydrin and 7.5 pounds (3.4 Kg) of acrylic acid were
charged and the temperature was controlled at 50.degree. C. with
steam-water in the Jacket. An initiator solution consisting of
58.42 grams of triethyl oxonium hexafluorophosphate (TEOP) and 2300
ml. of methylene chloride was metered into the reactor with a rate
of 160 ml. added initially, 300 ml. for the first hour, and 460 ml.
per hour in the 2nd thru 5th hours. The reaction was proceeded for
an additional one-half hour and was short-stopped with 2300 ml of
solution which is made up of 1 to 4 by volume ratio of ammonium
hydroxide and isopropyl alcohol. The reaction yielded a 39.1% of
theoretical conversion and after stripping off the unreacted
epichlorohydrin, the polymer has a Brookfield viscosity of 323.5
Pa.S (323,500 cps) at 27.degree. C. and an iodine number of
6.05.
EXAMPLE 2
The same procedure as described in Example 1 was followed for a
reaction which employed 498 pounds (226.09 Kg.) of epichlorohydrin
and 2 pounds (908 grams) of acrylic acid with the exception that in
this charge the acrylic acid was charged incrementally with 450
grams added initially, and 170, 120, 90 and 80 grams added at
subsequent first through fourth hours. The reaction yielded a
theoretical conversion of 53.7% and the polymer has a Brookfield
viscosity of 4400 Pa.S at 27.degree. C. (4,400,000 cps) and an
iodine number of 1.4.
EXAMPLE 3
The same procedure, as described in Example 1, was employed for a
reaction which employed 495 pounds (224.73 Kg) of epichlorohydrin
and 5 pounds (2.27 Kg) of acrylic acid, except that the acrylic
acid was charged incrementally with 3 pounds (1.362 Kg) added
initially and 1.5 lbs. (681 grams) and 0.5 pound (227 grams) added
at the first and second hour, respectively. The reaction yielded a
theoretical conversion of 53.9% and the polymer has a Brookfield
viscosity of 776 Pa.S (776,000 cps) at 27.degree. C. and an iodine
number of 3.6.
EXAMPLE 4
This example is presented to show the improvement in toughness
imparted to an unsaturated polyester sheet molding compound by the
use of a liquid polyepichorohydrin polymer. A compound containing
no liquid rubber (control) and a compound containing a liquid
acrylonitrile/butadiene rubber (sample 2) are compared with the
compound containing liquid polyepichlorohydrin (sample 1.).
TABLE I ______________________________________ Sample Ingredient
(Parts By Weight) Control No. 1 No. 2
______________________________________ Unsaturate Polyester
Resin.sup.(1) 65 65 65 Low profile additive.sup.(2) 35 35 35
Calcium Carbonate 125 125 125 Zinc Stearate 4 4 4 t-butyl
Perbenzoate 1.2 1.2 1.2 MgO 1.75 2.05 2.15 Liquid Vinyl
Terminated.sup.(3) Polyether (VTE) -- 8.0 -- Liquid
Acrylonitrile/butadiene.sup.(4) -- -- 8.0
______________________________________ .sup.(1) A 40% solution of
isophthalic unsaturated polyester resin dissolved in styrene
monomer supplied by U.S. Steel. Marco Div. as GR13031. .sup.(2) A
60% solution of polystyrene dissolved in styrene low profile
additive supplied by U.S. Steel. Marco Div. under the trade name of
GR63004. .sup.(3) Made by the procedure described in Example 3.
.sup.(4) A liquid polymer containing 33% acrylonitrile.
The compositions were prepared by mixing the polyester resin,
low-profile additive (both of which were dissolved in a
polymerizable monomer), calcium carbonate, zinc stearate and liquid
polymer (in samples 1 and 2 only). The liquid ingredients
(polyester resin, low-profile additive and rubber) were first mixed
together. The liquid ingredients were then mixed with the calcium
carbonate and zinc stearate in a Cowles mixer for 15 minutes and
then the catalysts were added to the mix and mixing continued for 3
minutes. The M.sub.g O was then added and mixing continued for 2
minutes. The compositions were then spread onto sheets of
polyethylene and chopped glass fibers (11/4 inch long) was sprayed
onto the compositions. The sheets were brought together to form a
composite. The composite was passed through compression rollers to
effect impregnation of the glass fibers by the resin mix. The
quantity of chopped glass fibers used was such that the final sheet
molding compositions were a nominal 21% glass. The compositions
were then rolled up in the polyethylene and allowed to thicken for
about 72 hours at 32.degree. C. The sheets were then cut into
sample size and cured for 3 minutes at 150.degree. C. in a 50 ton
press. Testing results are shown in Table II.
TABLE II ______________________________________ Sample Test Control
1 No. 1 No. 2 ______________________________________ % Shrink 0 0 0
Barcol Hardness Unnotched Izod (J/cm) 3.6 4.1 3.6 Tensile Stress
(MPa) 68.4 60.6 68.0 Tensile Elongation (%) 1.76 1.70 1.88 Tensile
Modulus (G Pa) 10.3 8.4 7.8 Flexure Stress (MPa) 119 138 93 Flexure
Strain (cm/cm) 0.022 .025 .019 Flexure Modulus (GPa) 10.4 10.3 9.4
Flexure Energy (J) 1.46 1.90 1.10 Acoustic Emission (counts) 8020
2570 2630 ______________________________________
The acoustic emission test was devised to measure cracking during a
simple cantilever bending load. In it a 3.2 mm thick sample, 38 mm
wide and 127 mm long is mounted in a Tinius Olsen Stiffness Tester
and bent by applying a weight of 22.7 kg. The sample bent until 70%
of the weight was applied to it. The load caused the sample to bend
through 6.degree.-7.degree. of measured arc. Commercial acoustic
emission equipment such as the Dunegan/Endevco 3000 Series can be
used to record the extent of cracking of the samples during this
test. Approximately ten samples per test are required for a
reliable evaluation.
The above test results show that the toughness is greatly improved
in the composition containing vinyl terminated polyepichlorohydrin
(Sample 1) as is shown by the acoustic emission cracks, Izod impact
test and the flexural energy test. Other important properties such
as stress are also improved, while elastic moduli are not adversely
effected. Processing characteristics such as shrink, cure rate and
maturation are not significantly effected by the use of vinyl
terminated polyepichlorohydrin as a toughener. The significant
improvements in Izod, acoustic emission and flexural energy were
not present in the sample containing the other liquid polymer
(Sample 2).
* * * * *