U.S. patent application number 14/800245 was filed with the patent office on 2016-04-21 for acetoacetyl thermosetting resin for gel coat.
This patent application is currently assigned to POLYNT COMPOSITES USA INC.. The applicant listed for this patent is Polynt Composites USA Inc.. Invention is credited to Chih-Pin Hsu, Richard Landtiser, Steven L. Voeks, Ming Yang Zhao.
Application Number | 20160108248 14/800245 |
Document ID | / |
Family ID | 47843311 |
Filed Date | 2016-04-21 |
United States Patent
Application |
20160108248 |
Kind Code |
A1 |
Zhao; Ming Yang ; et
al. |
April 21, 2016 |
Acetoacetyl Thermosetting Resin for Gel Coat
Abstract
Zero VOC thermosetting gel coat and laminating resin
compositions, and composites and articles, are produced using a
multifunctional Michael acceptor, a multifunctional Michael donor
and a base catalyst. The obtained low viscosity resin is useful for
producing zero VOC gel coats and laminates having excellent
curability at ambient temperatures.
Inventors: |
Zhao; Ming Yang; (Kansas
City, MO) ; Hsu; Chih-Pin; (Parkville, MO) ;
Voeks; Steven L.; (Smithville, MO) ; Landtiser;
Richard; (Parkville, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Polynt Composites USA Inc. |
Carpentersville |
IL |
US |
|
|
Assignee: |
POLYNT COMPOSITES USA INC.
Carpentersville
IL
|
Family ID: |
47843311 |
Appl. No.: |
14/800245 |
Filed: |
July 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13790608 |
Mar 8, 2013 |
|
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14800245 |
|
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61608760 |
Mar 9, 2012 |
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Current U.S.
Class: |
264/265 ;
524/451; 524/533; 524/849 |
Current CPC
Class: |
C08K 3/36 20130101; C08K
2003/2241 20130101; B65D 25/14 20130101; Y10T 428/31909 20150401;
C09D 4/06 20130101; C08K 3/22 20130101; C08K 3/34 20130101; C09D
4/00 20130101 |
International
Class: |
C09D 4/00 20060101
C09D004/00; C09D 4/06 20060101 C09D004/06 |
Claims
1. A method of making a styrene free gel coat composition,
comprising: reacting a polyhydroxy polyol having at least two
hydroxyl groups per molecule with a C.sub.1-C.sub.5 alkyl
acetoacetate in a transesterification process to form a
crosslinkable, multifunctional acetoacetylated polyhydroxy polyol
having at least two acetoacetyl functional groups per oligomer; and
combining the acetoacetylated polyhydroxy polyol with one or more
multifunctional acrylate monomers or oligomers, a thixotropic
agent, and a base catalyst, to form a crosslinkable, styrene free,
thermosetting gel coat composition having a viscosity at ambient
temperature of about 50 to 1200 cps under high shear and of about
8,000 to about 25,000 cps at low shear.
2. The method of claim 1, wherein the polyhydroxy polyol has at
least three hydroxyl groups per molecule.
3. The method of claim 1, wherein the acetoacetylated polyhydroxy
polyol has at least three acetoacetyl functional groups per
oligomer.
4. The method of claim 1, wherein the acetoacetylated polyhydroxy
polyol has: an acetoacetyl content of 5 to 80 weight %, a hydroxyl
number of 0 to 60 mg KOH/g, an acid value of 0 to 5 mg KOH/g, and a
number average molecular weight (Mn) of 250 to 6000 g
mole.sup.-1.
5. The method of claim 1, wherein the molar ratio of the
acetoacetate functional group of acetoacetylated polyhydroxy polyol
to the acrylate functional group of one or more acrylate monomers
or oligomers is 0.2 to 5.0.
6. The method of claim 5, wherein the molar ratio is 0.3 to
3.0.
7. The method of claim 1, wherein the gel coat composition
comprises: 15 to 70 wt % of the acetoacetylated polyhydroxy polyol,
15 to 70 wt % of the one or more multifunctional acrylate monomers
or oligomers, and 2 to 40 wt % of one or more additives including
the thixotropic agent, based on the total weight of the
composition.
8. The method of claim 1, further comprising allowing the gel coat
composition to cure at ambient temperature to form a crosslinked,
thermoset gel coat comprising crosslinked
acetoacetylate-functionalized acrylate oligomers.
9. The method of claim 8, wherein the gel coat is at least 50%
crosslinked.
10. The method of claim 8, wherein the gel coat is 70 to 100%
crosslinked.
11. The method of claim 1, wherein the polyhydroxy polyol is
selected from the group consisting of methyl propanediol (MPD),
trimethylolpropane (TMP), trimethylpentanediol,
di-trimethylolpropane (di-TMP), butyl ethyl propanediol (BEPD),
neopentyl glycol (NEO), pentaerythritol (Penta), di-pentaerythritol
(di-Penta), tris-2-hydroxyethyl isocyanurate (THEW),
4,4'-isopropylidenedicyclohexanol (hydrogenated bisphenol-A (HBP
A), and hydroxyl-functionalized acrylic polymers, and mixtures
thereof.
12. The method of claim 1, wherein the C.sub.1-C.sub.5 alkyl
acetoacetate is selected from the group consisting of methyl
acetoacetate (MAA), ethyl acetoacetate (EAA), n-propyl
acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate,
tert-butyl acetoacetate (TBAA), pentyl (amyl) acetoacetate,
n-pentyl acetoacetate, isopentyl acetoacetate, tert-pentyl
acetoacetate, and acetoacetate-functionalized acrylic polymer based
on acetoacetoxyethyl methacrylate, and mixtures thereof.
13. The method of claim 1, wherein the additive component is
selected from the group consisting of fillers, pigments,
thixotropic agents, promoters, inhibitors, stabilizers, extenders,
air release agents, leveling agents, and combinations thereof.
14. The method of claim 13, wherein the additive component
comprises a filler selected from the group consisting of clay,
magnesium oxide, magnesium hydroxide, aluminum trihydrate (ATH),
calcium carbonate, calcium silicate, mica, aluminum hydroxide,
barium sulfate and talc, and mixtures thereof.
15. The method of claim 13, wherein the additive component
comprises titanium dioxide.
16. The method of claim 1, wherein the thixotropic agent is
selected from the group consisting of fumed silica, precipitated
silica, and bentonite clay, and mixtures thereof.
17. The method of claim 1, wherein the base catalyst is selected
from the group consisting of 1,8-diazabicyclo-[5.4.0]undec-7-ene
(DBU), 1,5-diazabicyclo[4,3,0]non-5-ene (DBN),
1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD),
7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene (MTBD),
tetramethylguanidine (TMG) and 1,4-diazabicyclo[2.2.2]octane
(DABCO), and N'-butyl-N'',N''-dicyclohexylguanidine, and mixtures
thereof.
18. A method of making a gel coated article, comprising: reacting a
polyhydroxy polyol having at least two hydroxyl groups per molecule
with a C.sub.1-C.sub.5 alkyl acetoacetate in a transesterification
process to form a crosslinkable, multifunctional acetoacetylated
polyhydroxy polyol having at least two acetoacetyl functional
groups per oligomer; combining the acetoacetylated polyhydroxy
polyol with one or more multifunctional acrylate monomers or
oligomers, at least one additive component, and a base catalyst, to
form a crosslinkable thermosetting gel coat composition having a
viscosity at ambient temperature of about 50 to 1200 cps under high
shear and of about 8,000 to about 25,000 cps at low shear; and
applying the thermosetting gel coat composition as an in-mold
coating to a surface of a mold; allowing the gel coat composition
to cure at ambient temperature to form a partially crosslinked,
tacky to tacky-free gel coat; applying a material to be molded onto
the partially crosslinked gel coat; applying a crosslinkable
laminating resin onto said material, the laminating resin
comprising an acetoacetylated polyhydroxy polyol having at least
two acetoacetyl functional groups per molecule, one or more
multifunctional acrylate monomers or oligomers and a base catalyst;
and allowing the laminating resin and the gel coat to cure at
ambient temperature to a solid, crosslinked, thermoset resin being
styrene free.
19. The method of claim 18, wherein the polyhydroxy polyol has at
least three hydroxyl groups per molecule.
20-30. (canceled)
31. The method of claim 1, wherein the polyhydroxy polyol is
selected from the group consisting of di-pentaerythritol
(di-Penta), tris-2-hydroxyethyl isocyanurate (THEIC),
4,4'-isopropylidenedicyclohexanol (hydrogenated bisphenol-A (HBP
A), and hydroxyl-functionalized acrylic polymers, and mixtures
thereof.
Description
FIELD OF THE INVENTION
[0001] Embodiments of the invention relate generally to the field
of gel coats and laminating resins, and more particularly to
methods of making low viscosity, low to zero VOC acetoacetyl
thermosetting resins for gel coat and laminating resin compositions
utilizing a Michael-type addition crosslinking reaction.
BACKGROUND OF THE INVENTION
[0002] The application of gel coats are widely used in numerous
applications as the external surface layer of composite molded
articles. Gel coats are typically found on composite articles that
are exposed to the environment requiring moisture resistance,
resistance to cracking and similar properties, or articles that
require a strong, flexible, abrasion and impact resistant surface
and/or a smooth glossy finish. Examples of such articles include
boat hulls, bath tub enclosures, pools, spas, and body panels on
cars and trucks, among others.
[0003] Such gel coated articles are typically formed by spraying a
gel coat composition from a high pressure spray gun onto the inside
surface of an open mold, applying the materials and a laminating
resin for the composite article onto the gel coat, curing the gel
coat and then removing the cured gel coated article from the mold.
Gel coated articles can also be fabricated by applying the
composite materials into a multi-part mold, injecting or applying
the gel coat composition, closing the mold, curing the gel coat and
then removing the cured gel coated article from the mold.
[0004] Gel coats for composite articles are typically formulated
from a thermosetting base resin system such as unsaturated
polyester, acrylate and urethane type resins with incorporated
fillers, pigments and other additives. The gel coat should exhibit
low viscosity at high shear to allow for ease of application to the
mold, but also resist sagging or running after it is applied.
Another important property of gel coats is surface tackiness and
cure time. A gel coat desirably produces a gel time of 10 to 20
minutes. Many low or zero VOC gel coats remain tacky after several
hours of curing.
[0005] Typically, the gel coat resin is mixed with reactive,
polymerizable monomers such as styrene or methyl methacrylate
(MMA), which are also used to reduce resin system viscosity in
order to apply the gel coat by spraying. Conventional gel coat
compositions contain 35 to 45 wt % of reactive monomers and other
volatile organic compounds (VOCs). The presence of high amounts of
styrene and other VOCs results the emission of styrene vapors and
other hazardous air pollutants (HAP), which are closely regulated
by government regulations. Consequently, the composites industry is
very interested in providing gel coats that emit low to zero
VOCs.
[0006] However, there are difficulties in attaining gel coats
having low to zero VOCs and acceptable application and performance
properties. Several approaches have been described for addressing
these requirements. One way to reduce VOCs is to reduce the
molecular weight of the resin, which leads to a lower viscosity and
lower styrene need. However, in application, a gel coat made with a
lower molecular weight resin tends to remain tacky for long periods
of time. The use of higher molecular weight resins results in
higher viscosities that hamper spray applications of the gel coat
composition, which generally require a viscosity in the range of 50
to 1200 cps under high shear. In order to achieve target viscosity,
monomers with high boiling point are used to replace monomers which
contribute to VOC. These high boiling point monomers typically have
higher viscosity and lower reactivity with a resin solid. As a
result, a higher amount of high-boiling point monomers is required
to replace the standard monomers in gel coat formulations and the
resulting product is very slow to cure.
[0007] There remains a significant need for a resin material that
provides good rheology properties for in-mold coating applications,
fast curing and a better cured gel coat product having low to zero
VOCs and a high degree of crosslinking.
SUMMARY OF THE INVENTION
[0008] The invention provides methods and gel coat and laminating
resin compositions that overcome the above-described deficiencies
and provide styrene free and zero VOC gel coats having a desirable
viscosity for application, a fast gel time and set-up, and produce
cured gel coats and laminating resins having a high degree of
crosslinking with excellent performance properties.
[0009] In embodiments, the invention provides methods for making
styrene free and zero VOC gel coats. In one embodiment, the method
comprises: [0010] reacting a polyhydroxy polyol having at least
two, preferably three, hydroxyl groups per molecule with a
C.sub.1-C.sub.5 alkyl acetoacetate in a transesterification process
to form a crosslinkable, multifunctional acetoacetylated
polyhydroxy polyol having at least two acetoacetyl functional
groups per oligomer; and [0011] combining the acetoacetylated
polyhydroxy polyol with one or more multifunctional acrylate
monomers or oligomers, at least one additive component, and a base
catalyst, to form a crosslinkable, thermosetting gel coat
composition having a viscosity of about 50 to 1200 cps under high
shear.
[0012] In use, the gel coat composition can be used in making a gel
coated article. In embodiments, the gel coated article is
fabricated by: [0013] applying the thermosetting gel coat
composition as an in-mold coating to a surface of a mold; [0014]
allowing the gel coat composition to cure at ambient temperature to
form a partially crosslinked, tacky to tacky-free gel coat; [0015]
applying a material to be molded onto the partially crosslinked gel
coat; [0016] applying a crosslinkable laminating resin onto said
material, the laminating resin comprising an acetoacetylated
polyhydroxy polyol having at least two, preferably three,
acetoacetyl functional groups per oligomer, one or more
multifunctional acrylate monomers or oligomers and a base catalyst;
and [0017] allowing the laminating resin and the gel coat to cure
at ambient temperature to a solid, crosslinked, thermoset resin
being styrene free with zero VOCs.
[0018] The resulting gel coated article comprises the cured
thermoset gel coat bonded onto the surface of the article. In
embodiments, the cured thermoset gel coat and laminating resin
comprise crosslinked acetoacetate functionalized acrylate
oligomers, and are preferably at least 50%, preferably 70 to 100%,
crosslinked.
[0019] The invention also provides methods for making a laminating
resin composition. In embodiments, the method comprises: [0020]
reacting a polyhydroxy polyol having at least two, preferably
three, hydroxyl groups per molecule with a C.sub.1-C.sub.5 alkyl
acetoacetate in a transesterification process to form a
crosslinkable, multifunctional acetoacetylated polyhydroxy polyol
having at least two, preferably three, acetoacetyl functional
groups per oligomer; and [0021] combining the acetoacetylated
polyhydroxy polyol with one or more multifunctional acrylate
monomers or oligomers and a base catalyst to form a crosslinkable,
thermosetting laminating resin composition having a Brookfield
viscosity of about 50 to 1200 cps.
[0022] The laminating resin composition can be cured at ambient
temperature to form a solid, crosslinked, thermoset resin
comprising crosslinked acetoacetate-functionalized acrylate
oligomers, with the laminating resin being styrene free with zero
VOCs and preferably at least 50%, preferably 70 to 100%,
crosslinked.
[0023] The invention further provides a crosslinkable, styrene free
and zero VOC gel coat composition. In an embodiment, the
crosslinkable gel coat composition comprises an acetoacetylated
polyhydroxy polyol, one or more multifunctional acrylate monomers
or oligomers, a base catalyst, and at least one additive component
selected from the group consisting of fillers, pigments and
thixotropic agents, and has a viscosity of about 50 to 1200 cps
under high shear, and is curable under ambient conditions to form a
solid thermoset gel coat comprising crosslinked
acetoacetate-functionalized acrylate oligomers, the gel coat being
styrene free with zero VOCs and preferably at least 50%, preferably
70 to 100%, crosslinked.
[0024] The invention also provides a crosslinkable, styrene free
and zero VOC laminating resin composition. In an embodiment, the
crosslinkable laminating resin composition comprises an
acetoacetylated polyhydroxy polyol, one or more multifunctional
acrylate monomers or oligomers, and a base catalyst, and has a
Brookfield viscosity of about 50 to 1200 cps, and is curable under
ambient conditions to form a laminating resin comprising
crosslinked acetoacetate-functionalized acrylate oligomers, the
laminating resin being styrene free with zero VOCs and preferably
at least 50%, preferably 70 to 100%, crosslinked.
[0025] Also provided is a system for forming a gel coat
composition. In an embodiment, the system is composed of separate
containers packaged together, including: [0026] a container of a
curable, thermosetting gel coat composition comprising a
crosslinkable, multifunctional acetoacetylated polyhydroxy polyol
having at least two, preferably three, acetoacetyl functional
groups per oligomer, one or more multifunctional acrylate monomers
or oligomers and at least one additive component selected from the
group consisting of fillers, pigments and thixotropic agents for a
gel coat; [0027] a container of a base catalyst selected from the
group consisting of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU),
1,5-diazabicyclo[4,3,0]non-5-ene (DBN),
1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD),
7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene (MTBD),
tetramethylguanidine (TMG) and 1,4-diazabicyclo[2.2.2]octane
(DABCO), and N'-butyl-N'',N''-dicyclohexylguanidine, and mixtures
thereof; and [0028] directions for combining the contents of the
containers to form a thermosetting gel coat composition, which, in
embodiments, has a viscosity of about 50 to 1200 cps under high
shear, is curable at ambient temperature to form a crosslinked,
styrene free and zero VOC thermoset gel coat comprising crosslinked
acetoacetate-functionalized acrylate oligomers, which is preferably
at least 50%, preferably 70 to 100%, crosslinked.
[0029] A system is also provided for forming a laminating resin
composition. In an embodiment, the system is composed of separate
containers packaged together, including: [0030] a container of a
curable, thermosetting laminating resin composition comprising a
crosslinkable, multifunctional acetoacetylated polyhydroxy polyol
having at least two, preferably three, acetoacetyl functional
groups per oligomer and one or more multifunctional acrylate
monomers or oligomers; [0031] a container of a base catalyst
selected from the group consisting of
1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU),
1,5-diazabicyclo[4,3,0]non-5-ene (DBN),
1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD),
7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene (MTBD),
tetramethylguanidine (TMG) and 1,4-diazabicyclo[2.2.2]octane
(DABCO), and N'-butyl-N'',N''-dicyclohexylguanidine, and mixtures
thereof; and [0032] directions for combining the contents of the
containers to form a thermosetting laminating resin composition,
which, in embodiments, has a Brookfield viscosity of about 50 to
1200 cps, is curable at ambient temperature to form a crosslinked,
styrene free and zero VOC thermoset laminating resin comprising
crosslinked acetoacetate-functionalized acrylate oligomers, which
is preferably at least 50%, preferably 70 to 100%, crosslinked.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Embodiments of the invention relate to methods of making
zero VOC, crosslinkable, thermosetting resins from
acetoacetate-functionalized polyhydroxy polyols and multifunctional
acrylate monomers or oligomers for producing laminating resins and
gel coat compositions, which are crosslinked using a Michael-type
addition reaction with a base catalyst to obtain laminates and gel
coated articles. The thermosetting resins have excellent curability
at ambient or room temperatures. In embodiments, the process
results in an at least 50%, preferably 70 to 100%, crosslinked
thermoset polymer network that is VOC and styrene free with
excellent mechanical properties.
[0034] The thermosetting resins are crosslinked without styrene or
free-radicals, using a Michael-type addition reaction with a base
catalyst at ambient temperatures to incorporate acrylate
functionality into a multifunctional acetoacetylated polyhydroxy
polyol to produce a thermoset, crosslinked polymer network in which
the acetoacetate-functionalized acrylate oligomers are up to 100%
crosslinked.
[0035] Unless otherwise specified herein, the term "viscosity"
refers to the viscosity of a polymer in monomer at 25.degree. C.
(77.degree. C.) measured in centipoise (cps) using a Brookfield RV
model viscometer. The viscosity under high shear is measured by a
cone and plate (CAP) viscometer at a shear rate of 10,000 l/s. The
term "NVM" refers to non-volatile material dispersed in a volatile
substance (e.g., monomer) as measured according to ASTM D1259.
[0036] Unless stated otherwise, all percent and ratios of amounts
are by weight.
Acetoacetate-Functionalized Polyhydroxy Polyol
[0037] The acetoacetate-functionalized polyhydroxy polyol has at
least two, and in some embodiments preferably at least three
acetoacetyl functional groups per oligomer. The functionalized
polyol is then blended with a multifunctional acrylate to form a
thermosetting, crosslinkable resin.
[0038] In embodiments of the invention, multifunctional
acetoacetylated polyols can be prepared by reaction of a
polyhydroxy polyol (also termed "polyhydric alcohol" or "polymeric
polyol"), in a transesterification reaction with an alkyl
acetoacetate compound, preferably a C.sub.1-C.sub.5 alkyl
acetoacetate.
[0039] Suitable polyhydroxy polyol compounds have an average of at
least two, preferably at least three (i.e., tripolyol), hydroxyl
groups per molecule. Non-limiting examples of polyhydroxy polyols
include methyl propanediol (MPD), trimethylolpropane (TMP),
trimethylpentanediol, di-trimethylolpropane (di-TMP), butyl ethyl
propanediol (BEPD), neopentyl glycol (NEO), pentaerythritol
(Penta), di-pentaerythritol (di-Penta), tris-2-hydroxyethyl
isocyanurate (THEIC), 4,4'-isopropylidenedicyclohexanol
(hydrogenated bisphenol-A (HBPA), hydroxyl-functionalized acrylic
polymers, among others, and mixtures of two or more of such
compounds. In embodiments, the polyhydroxy polyol has a hydroxyl
number of from 30 up to 1850 mg/KOH/g, and a number average
molecular weight of 90 up to 5000 g/mol.
[0040] Non-limiting examples of suitable C.sub.1-C.sub.5 alkyl
acetoacetates (esters of acetoacetic acid) include methyl
acetoacetate (MAA), ethyl acetoacetate (EAA), n-propyl
acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate,
tert-butyl acetoacetate (TBAA), pentyl (amyl) acetoacetate,
n-pentyl acetoacetate, isopentyl acetoacetate, tert-pentyl
acetoacetate, acetoacetate-functionalized acrylic polymer based on
acetoacetoxyetheyl methacrylate, including copolymers with
different acrylic monomers, among others, and mixtures of two or
more of such compounds.
[0041] Procedures for preparing crosslinkable, functionalized
acetoacetylated polyols by reaction of a polyol with an alkyl
acetoacetate compound in a transesterification reaction are
generally known in the art. In embodiments, the polyol and alkyl
acetoacetate compounds are reacted in a transesterification
reaction at a temperature of 90 to 200.degree. C. for 3 to 15 hours
to form the functionalized polyol. In some embodiments, 10 to 90 wt
% polyol is combined with 90 to 10 wt % alkyl acetoacetate, based
on the total weight of the mixture.
[0042] In embodiments, at least 70% of the hydroxyl groups of the
polyhydroxy polyol are converted to acetoacetyl groups, and more
preferably 80 to 100% of the hydroxyl groups are converted. In
embodiments, the acetoacetylated polyols have an acetoacetyl
content within a range of from 5 to 80 weight %, a hydroxyl number
within a range of 0 to 60 mg KOH/g, and acid value of 0 to 5 mg
KOH/g, and a number average molecular weight (Mn) within a range of
250 to 6000 g mole.sup.-1, preferably 300 to 5000 g
mole.sup.-1.
[0043] In embodiments, the acetoacetate-functionalized polyol can
be prepared in a multi-stage reaction in which the polyhydroxy
polyol is initially reacted by the condensation reaction with a
dicarboxylic acid/anhydride or polyacid with a glycol or polyol.
Non-limiting examples of suitable carboxylic acids include
isophthalic acid, orthophthalic acid, terephtalic acid, succinic
acid, adipic acid, maleic acid, fumaric acid, azelaic acid,
1,4-cyclohexane dicarboxylic acid, itaconic acid, sebacic acid,
tetrahydrophthalic anhydride, trimelitic anhydride, among others,
and mixtures of two or more of such compounds. In embodiments, the
dicarboxylic acid and polyhydroxy polyol are reacted in a first
stage reaction at 150 to 225.degree. C. for about 5 to 20 hours,
until an acid value of less than 20 mg KOH/g, preferably less than
10 mg KOH/g, is reached. In embodiments, the molar ratio of acid
functional groups to hydroxyl functional groups is 0.2 to 0.8. In a
second stage reaction, an alkyl acetoacetate compound is mixed with
the resulting polyester polyol and the reaction proceeds for about
3 to 15 hours to form the acetoacetate-functionalized polyol. In
embodiments, 25 to 90 wt % of the polyester polyol is combined with
75 to 10 wt % alkyl acetoacetate, based on the total weight of the
mixture.
[0044] In another embodiment, the acetoacetate-functionalized
polyhydroxy polyol can be prepared in a multi-step reaction, in
which a C.sub.2 to C.sub.13 alkanolamine is reacted with a cyclic,
5-ring hydroxy-functional carbonate in a first step to form a
polyurethane polyol intermediate. In embodiments, the molar ratio
of alkanolamine to the 5-ring carbonate is at or about close to 1
with slightly excess of carbonate. Non-limiting examples of
suitable alkanolamines (also referred to as "amino alcohols")
include monoethanolamine (MEA), propanolamine, isopropanol amine,
and 2-aminobutanol, among others, and mixtures of two or more of
such compounds. Non-limiting examples of suitable 5-ring carbonates
include glycerine carbonate (GC), ethylene carbonate, propylene
carbonate and butylene carbonate, among others, and mixtures of two
or more of such compounds.
[0045] In embodiments, the alkanolamine and 5-ring
hydroxy-functional carbonate are reacted at 20 to 75.degree. C. for
about 5 to 8 hours. In a second stage reaction, the resulting
polyurethane polyol is mixed with an alkyl acetoacetate compound
and reacted for about 3 to 15 hours to form the functionalized
acetoacetylated polyol.
[0046] In another embodiment, the acetoacetate-functionalized
polyhydroxy polyol can be prepared in a multi-step reaction, in
which the polyol is formed through free radical copolymerization of
vinyl monomers and at least one vinyl monomer containing hydroxyl
groups. The resulting polyol contains at least two, preferably
three, hydroxyl functional groups in each polymer. Non-limiting
examples of suitable vinyl monomers containing hydroxyl groups
include hydroxyethyl acrylate, hydroxyethyl methacrylate,
hydroxypropyl acrylate, and hydroxylpropyl methacrylate, among
others, and mixtures of two or more of such compounds. Non-limiting
examples of suitable vinyl monomers include aromatic compounds such
as styrene, alpha-methyl styrene, vinyl toluene, vinyl phenol and
the like, and unsaturated esters such as acrylic and methacrylic
ester, vinyl laurate and the like, among others, and mixtures
thereof. In a second stage reaction, the resulting polyol is mixed
with an alkyl acetoacetate compound and reacted for about 3 to 15
hours to form the functionalized acetoacetylated polyol.
[0047] In another embodiment, the acetoacetate functionalized
polyhydroxy polyol is made directly by free radical
copolymerization of vinyl monomers and at least one vinyl monomer
contains acetoacetate functional group. The resulting copolymer
contains at least two, preferably three, acetoacetate functional
groups in each polymer. Non-limiting examples of suitable vinyl
monomers containing acetoacetate functional group include
acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate
(AAEA), acetoacetoxypropyl methacrylate, acetoacetoxypropyl
acrylate, acetoacetoxybutyl methacrylate, and acetoacetoxybutyl
acrylate, among others, and mixtures thereof.
[0048] The resulting acetoacetylate-functionalized polymer is a
thermosetting, crosslinkable resin, having at least two, and in
some embodiments at least three, acetoacetyl functional groups per
polymer, which can be used, for example, in the formulation of
laminating resins and gel coat compositions.
Gel Coats
[0049] Gel coats (also termed "gel coat compositions") are
compositions in a curable (e.g., pre-cured) state, composed of a
blend of one or more of the acetoacetate-functionalized polyhydroxy
polyol resin material with one or more multifunctional acrylate
monomers and/or oligomers and one or more additives. Gel coats are
typically free of fibers. In embodiments, the
acetoacetate-functionalized polyol is combined with the one or more
multifunctional acrylate monomers or oligomers. Preferably, the
molar ratio of the acetoacetate functional group to acrylate
functional group is 0.2 to 5.0, and preferably, a molar ratio of
0.3 to 3.0. In embodiments, 15 to 70 wt % of the
acetoacetate-functionalized polyol is combined with 15 to 70 wt %
of one or more multifunctional acrylate monomers or oligomers and 2
to 40 wt-% additives, based on the total weight of the mixture.
[0050] The gel coat composition can be prepared by high speed
dispersion of the filler, pigment and other additives into the
resin mixture. The viscosity of the gel coat composition (without
catalyst) can range from 8,000 to 25,000 cps, and preferably 10,000
to 20,000 cps when measured by Brookfield viscometer at 4 rpm.
[0051] Multifunctional Acrylate Monomers.
[0052] Non-limiting examples of suitable multifunctional acrylate
monomers include trimethylolpropane triacrylate (TMPTA),
di-trimethylolpropane tetraacrylate, tris(2-hydroxy ethyl)
isocyanurate triacrylate, ethoxylated trimethylolpropane
triacrylate, polyethylene glycol diacrylate, neopentyl glycol
diacrylate, pentaerythritol tetraacrylate, 1,2-ethylene glycol
diacrylate, 1,6-hexanediol diacrylate, 1,12-dodecanol diacrylate,
hexanediol diacrylate, tripropylene glycol diacrylate, dipropylene
glycol diacrylate, amine modified polyether acrylates, glycerol
propoxylate triacrylate, dipentaerythritol pentaacrylate,
dipentaerythritol hexaacrylate, ethoxylated pentaerythritol
tetraacrylate, and the like, as well as mixtures and combinations
thereof.
[0053] Additives.
[0054] The gel coat composition includes one or more additive
components, for example, one or more fillers, pigments, and/or
other additives such thixotropic agents, promoters, stabilizers,
extenders, wetting agent, leveling agents, air release agents, as
practiced in the art to adjust and enhance the molding properties
(e.g., color effect, sprayability, sag resistance, mechanical
property consistency, etc.). Gel coats are typically free of
fibers.
[0055] Examples of fillers for gel coats include inorganic
(mineral) fillers, such as clay, magnesium oxide, magnesium
hydroxide, aluminum trihydrate (ATH), calcium carbonate, calcium
silicate, mica, aluminum hydroxide, barium sulfate, talc, etc., and
organic fillers. The amount of filler in the gel coat composition
can generally range from 5 up to 30 wt %, based on the total weight
of the gel coat composition. Suitable pigments include inorganic
pigments, such as titanium dioxide. Thixotropic agents include
silica compounds such as fumed silica and precipitated silica, and
inorganic clays such as bentonite clay, which, if included, can be
present in an amount ranging from 0.3 up to 6 wt %, based on the
total weight of the gel coat composition.
Laminating Resin
[0056] In embodiments, the acetoacetate-functionalized polyhydroxy
polyol resin material can be combined with one or more
multifunctional acrylate monomers/oligomers (as described above) to
form a curable laminating resin composition. In embodiments, the
laminating resin composition is composed of 10 to 90 wt % of the
acetoacetate-functionalized polyol combined with 90 to 10 wt % of
multifunctional acrylate monomers/oligomers, based on the total
weight of the mixture. Preferably, the ratio of the functionalized
polyol to multifunctional acrylate monomer/oligomer is 0.2 to 8.5,
and more preferably a ratio of 0.25 to 8.0 (w/w). The viscosity of
the laminating resin composition is preferably about 50 to 1200
cps.
[0057] In use, the laminating resin composition is combined with a
base catalyst, and can be utilized in many applications such as for
coatings and in reinforced composite products by various open and
closed molding processes such as spray-up, hand lay-up, resin
transfer molding and wet molding.
Applications
[0058] In use, the gel coat composition is combined with a base
catalyst and applied as an in-mold coating, typically by manual
application or using a gel coat spray technique, onto the surface
of a mold that is in the shape and form of the desired article
(e.g., bathtub, car or aircraft part, boat hull, swimming pool,
etc.). The gel coat is allowed to partially cure such that it is
tacky to tacky-free.
[0059] The amount of base catalyst included in the gel coat
composition is typically 0.2 to 2.5% by weight, based on the total
weight of the composition. For optimal processibility, gel time and
cure time, the viscosity of the gel coat (with catalyst) can range
from 8,000 to 25,000 cps, and preferably 10,000 to 20,000 cps
measured by Brookfield viscometer at 4 rpm. Preferably, the gel
time of the gel coat is 5 to 30 minutes at ambient temperature. The
term "gel time" refers to the time from catalyzation of the gel
coat (or laminating resin) to cessation of flow.
[0060] Crosslinking of the laminating resin and gel coat occurs by
a base-catalyzed Michael-type addition reaction of the
acetoacetate-functionalized polyhydroxy polyol and multifunctional
acrylate monomers or oligomers at ambient temperatures (about 20 to
25.degree. C.), without heat or UV radiation. The base catalysts
are nitrogen containing compounds, which can be represented by the
general formula R.sup.xR.sup.yR.sup.zN, where R.sup.x, R.sup.y, and
R.sup.z each individually may represent hydrogen, or a
C.sub.1-C.sub.20 alkyl, aryl, alkylaryl or arylalkyl group, that
each optionally may contain one or more hetero-atoms (e.g. oxygen,
phosphor, nitrogen or sulfur atoms) and/or substituents. The group
may be linear or branched; they also may contain one or more
unsaturations or substituents. This general formula
R.sup.xR.sup.yR.sup.zN also represents nitrogen compounds, wherein
the nitrogen atom shown in the formula is part of a cyclic system
formed by two of the groups R.sup.x, R.sup.y, and R.sup.z, or is
present in the form of an imine group or as a phosphazene.
Non-limiting examples of suitable base catalysts include
1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU),
1,5-diazabicyclo[4,3,0]non-5-ene (DBN),
1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD),
7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene (MTBD),
tetramethylguanidine (TMG) and 1,4-diazabicyclo[2.2.2]octane
(DABCO), and N'-butyl-N'',N''-dicyclohexylguanidine, and the like.
In embodiments, the base catalyst can be combined with an organic
solvent such as methanol, ethanol, propanol, n-butyl alcohol,
acetone, methyl ethyl ketone, among others, and mixtures thereof.
In preferred embodiments, the base catalyst is used neat (absence
of a solvent).
[0061] The article can be a fully or partially cured polymer resin
or composite of reinforcing material in a polymer resin matrix. In
embodiments, a reinforcing material for forming the article is laid
into the open mold onto the partially cured gel coat material.
Non-limiting examples of reinforcing materials include glass fiber,
polyethylene fiber, carbon fiber, metal fiber, ceramic fiber, or
other material used in the composite plastics industry. In
embodiments, dry fibers (e.g., glass fibers, glass fiber matt,
etc.) are laid onto the partially cured gel coat within the open
mold.
[0062] The reinforcing material is then wet out by applying a
laminating resin in a curable (i.e., pre-cured) state that has been
combined with a base catalyst. In embodiments, the laminating resin
is composed of 10 to 90 wt % of the acetoacetate-functionalized
polyol, 90 to 10 wt % of multifunctional acrylate monomers or
oligomers, and 0.2 to 2.5 wt % base catalyst, based on the total
weight of the mixture.
[0063] The laminating resin is allowed to cure to form a hardened
fiber-reinforced resin composite in the desired shape within the
mold. The gel coat becomes an integral part of the finished
laminate article by forming a covalent interfacial bond with the
laminating resin that is used. The gel coat provides a primary bond
at the interface with the composite article, unlike the application
of a resin coating onto the formed article.
[0064] Curing of the laminating resin can be conducted at ambient
temperature for about 4 to 40 hours. The gel coated, composite
article can then be removed from the mold for use. In some
embodiments, the laminate can undergo a post-cure, for example, by
heating the mold to an elevated temperature (i.e., to 65.degree.
C.) to further increase the degree of cure.
[0065] The gel coats of the invention provide a durable and high
weather- and wear-resistant coating with good hydrolytic stability,
and/or an aesthetic finished surface to the article being produced
to improve surface appearance. The gel coats also provide a
resilient, light-stable surface covering and, in embodiments, are
sufficiently pigmented to yield a desired color. The base catalyzed
Michael addition of acetoacetylated resins to acrylate acceptors
produces crosslinked networks with low to no volatile organic
compounds (VOCs). In embodiments, the cured gel coat and/or
laminating resin is at least 50% crosslinked, and preferably 70 to
100% crosslinked. Such crosslinking can be assessed, for example,
by measuring the residual reaction exotherm by differential
scanning calorimetry (DSC).
[0066] The invention will be further described by reference to the
following detailed example. This example is not meant to limit the
scope of the invention that has been set forth in the foregoing
description. Variation within the concepts of the invention is
apparent to those skilled in the art. The disclosures of the cited
references throughout the application are incorporated by reference
herein.
EXAMPLES
[0067] The following examples are illustrations of the present
invention. They are not to be taken as limiting the scope of the
claimed invention. Unless stated otherwise, all percent and ratios
of amounts are by weight.
Materials and Abbreviations
[0068] The following materials were used in the Examples below.
TABLE-US-00001 Ingredient SR355 Di-trimethylolpropane tetraacrylate
(Sartomer Co.) SR368 Tris (2-hydroxy ethyl) isocyanurate
triacrylate (Sartomer Co.) SR454 Ethoxylated trimethylolpropane
triacrylate (Sartomer Co.) TMPTA Trimethylolpropane triacrylate DBU
1,8-Diazabicyclo-[5.4.0]undec-7-ene DABCO
1,4-Diazabicyclo[2.2.2]octane TMG Tetramethylguanidine
Example 1
Preparation of TMP Tris-Acetoacetate
[0069] A 3 liter, 4-neck round-bottom flask fitted with mechanical
stirrer, pressure equalizing addition funnel (nitrogen inlet),
thermocouple connected to a controller and heating mantle, was
charged with 604 g (4.50 mol) trimethylolpropane (TMP), 850 g
toluene and 303 g (1.92 mol) tert-butyl acetoacetate. The mixture
was heated to about 110.degree. C. Additional tert-butyl
acetoacetate, 1881 g (11.89 mol), was gradually added into flask
through additional funnel over about 5 hours. After all tert.-butyl
acetoacetate was added, the mixture temperature was increased
gradually to 135.degree. C. and keep at this temperature for 2
hours. A vacuum (26'' Hg) was applied to remove unreacted liquid
and a slight yellow liquid product of 1713 g was obtained.
[0070] The reaction is illustrated in Scheme 1 below.
##STR00001##
Example 2
Preparation of THEIC Tris-Acetoacetate
[0071] A 2 liter, 4-neck round-bottom flask fitted with mechanical
stirrer, pressure equalizing addition funnel (nitrogen inlet),
thermocouple connected to a controller and heating mantle, was
charged with 628 g (2.40 mol) tris(hydroxyl ethyl) isocyanurate
(THEIC) and 1140 g (7.20 mol) tert-butyl acetoacetate. The mixture
was heated gradually to about 150.degree. C. in 5 hours and keep at
this temperature for another 2 hours. A vacuum (26'' Hg) was
applied to remove unreacted liquid and a yellow liquid product of
1214 g was obtained.
[0072] The reaction is illustrated in Scheme 2 below.
##STR00002##
Example 3
Preparation of HBPA Di-Acetoacetate
[0073] A 1 liter, 4-neck round-bottom flask fitted with mechanical
stirrer, pressure equalizing addition funnel (nitrogen inlet),
thermocouple connected to a controller and heating mantle, was
charged with 481 g (2.00 mol) 4,4'-isopropylidenedicyclohexanol
(hydrogenated bisphenol-A (HBPA)) and 163 g (1.03 mol) tert-butyl
acetoacetate. The mixture was heated to about 110.degree. C.
Additional tert-butyl acetoacetate, 502 g (3.17 mol), was gradually
added into flask through additional funnel over about 3 hours.
After all tert-butyl acetoacetate was added, the temperature was
increased gradually to 150.degree. C. and keep at this temperature
for 2 hours. A vacuum (26'' Hg) was applied to remove unreacted
liquid and a yellow liquid product of 865 g was obtained.
[0074] The reaction is illustrated in Scheme 3.
##STR00003##
Example 4
Preparation of IPA-TMP Tetra-Acetoacetate
[0075] To a three-neck, round-bottom flask equipped with a
mechanical stirrer, thermocouple connected to a controller and
heating mantle, a Dean-Stark trap, a nitrogen inlet, and a water
condenser, was charged 831 g (5.00 mol) isophthalic acid (IPA) and
1342 g (10.00 mol) trimethylolpropane (TMP). The mixture was
allowed to react at 215.degree. C. for 8 hours until the acid
number was determined to be less than 3.0 mg KOH/g equivalent.
[0076] To 1038 g of the above resulting polyester polyol, 1684 g
tert-butyl acetoacetate was gradually added over about 3 hours at
160-170.degree. C. After all tert-butyl acetoacetate was added, the
temperature was increased gradually to 180.degree. C. and kept at
this temperature for another 2 hours. A vacuum (26'' Hg) was
applied to remove unreacted liquid and a yellow liquid product of
1846 g was obtained.
[0077] The reaction is illustrated in scheme 4.
##STR00004##
Example 5
Preparation of EA-GC Tris-Acetoacetate
[0078] To a three-neck, round-bottom flask equipped with a
mechanical stirrer, thermocouple connected to a controller and
heating mantle, a Dean-Stark trap, a nitrogen inlet, and a water
condenser, was charged 184 g (3.00 mol) ethanolamine (EA). 358 g
(3.00 mol) 4-hydroxymethyl-1,3-dioxolan-2-one (glycerine carbonate
(GC)) was added into the flask over 0.5 hr at 20-40.degree. C. The
mixture was allowed to react at 40-75.degree. C. for 6 hours.
[0079] To the resulting urethane tripolyol, 1424 g tert-butyl
acetoacetate was added and the temperature was increased gradually
to 140.degree. C. and kept at this temperature for another 3 hours.
A vacuum (26'' Hg) was applied to remove unreacted liquid and a
dark yellow liquid product of 1239 g was obtained.
[0080] The reaction is illustrated in Scheme 5.
##STR00005##
Example 6
Preparation of Acetoacetate-Functionalized Methacrylate Copolymer
Resin
[0081] To a three-neck, round-bottom flask equipped with a
mechanical stirrer, thermocouple connected to a controller and
heating mantle, a Dean-Stark trap, a nitrogen inlet, and a water
condenser, was charged 500 g of xylene. A monomer solution of 638 g
(2.87 mol) isobornyl methacrylate, 1052 g (4.91 mol)
acetoacetoxyethyl methacrylate, 66 g dicumyl peroxide and 3 g
2-mercaptoethanol was added over 4 hr at 140.degree. C. The mixture
was allowed to react at 140.degree. C. for another 2 hr. A vacuum
(26'' Hg) was applied to remove xylene and unreacted liquid. The
obtained methacrylate copolymer is solid at room temperature.
[0082] The reaction is illustrated in Scheme 6 below.
##STR00006##
Example 7
Preparation of Gel Coat Composition
[0083] A gel coat composition was prepared by mixing, respectively,
252 g of the IPA-TMP Tetra-Acetoacetate from Example 4, 184 g of
TMPTA, 120 g of titanium dioxide, 30 g of talc and 4 g of fumed
silica under high shear. The gel coat composition had a Brookfield
viscosity of 20,000 centipoise (cps) at 25.degree. C. (77.degree.
C.) at 4 rpm.
Example 8
Preparation of Laminating Resin Composition
[0084] A laminating resin was prepared by mixing, respectively, 263
g of IPA-TMP Tetra (Acetoacetate) from Example 4 and 285 g of
TMPTA. The laminating resin composition had a Brookfield viscosity
of 900 centipoise (cps) at 25.degree. C. (77.degree. C.).
Example 9
Preparation of DBU Catalyst Solution
[0085] A catalyst solution of DBU was prepared by dissolving 20 g
DBU in 7 g ethanol. The solution is a clear liquid.
Example 10
Preparation of DABCO Catalyst Solution
[0086] A catalyst solution of DABCO was prepared by dissolving 30 g
DABCO in 20 g ethanol. The solution is a clear liquid.
Example 11
Gel Coat Laminate Panel Preparation
[0087] 200 g of the gel coat composition from Example 7 was mixed
with 2.7 g DBU catalyst solution from Example 9 by hand. The gel
coat composition was sprayed on a waxed and buffed flat tempered
glass plate to a thickness of 15-40 mils (1 mil=0.001 inch). After
20 minutes at room temperature (25.degree. C.), the gel coat film
was tacky free.
[0088] 200 g of the laminating resin from Example 8 was mixed with
2.48 g (1.24 wt-%) DBU catalyst solution from Example 9. A 1/8''
laminate was formed by applying a 1.5 oz chop-strained mat and the
laminating resin/DBU catalyst mixture onto the gel coat film. The
laminate was allowed to cure for 16-20 hours at ambient temperature
(25.degree. C.), then removed from the mold and cut into test
parts.
Example 12
Gel Coat Formulation
[0089] Gel coat formulations were prepared by mixing, respectively,
TMPTris (Acetoacetate) (150 g) prepared from Example 1, the
acetoacetate-functionalized methacrylate copolymer resin (68 g)
prepared from Example 6, TMPTA (184 g), heptadecafluorodecyl
acrylate (9 g, Zonyl TA-N from DuPont), titanium dioxide (120 g),
talc (30 g) and fumed silica (4 g). The gel coat composition had a
Brookfield viscosity of 16650 centipoise (cps) at 25.degree. C.
(77.degree. C.) at 4 rpm.
Example 13
Gel Coat Laminate Panel Preparation
[0090] The gel coat composition (200 g) prepared from Example 7 was
mixed with the catalyst solution of DBU (1.0 g) and ethanol (0.3
g), and sprayed on a waxed and buffed flat tempered glass plate to
a thickness of 15-40 MILS (1 MIL-0.001 inch). After 20 min., the
gel coat film was tacky free and a barrier coat (ARMORGUARD from
CCP) was sprayed onto the film to a thickness of 23 MILS. A 1/8''
laminate is made using chopped fiberglass and a polyester resin
(STYPOL LSPA-2200, 40% mat/60% resin). Methyl ethyl ketone peroxide
(MEKP) co-initiator at 1.2 wt % is used to cure the polyester
resin. The laminate is allowed to cure for 16-20 hours at room
temperature, then removed from the mold and cut into test
parts.
Example 14
Gel Coat Laminate Panel Preparation
[0091] The gel coat composition (200 g) prepared from Example 7 was
mixed with the catalyst solution of DABCO (1.0 g) and ethanol (1.0
g), and sprayed on a waxed and buffed flat tempered glass plate to
a thickness of 15-40 MILS (1 MIL-0.001 inch). After 12 hr., the gel
coat film was somewhat tacky and a barrier coat (ARMORGUARD from
CCP) was sprayed onto the film to a thickness of 23 MILS. A 1/8''
laminate is made using chopped fiberglass and a polyester resin
(STYPOL LSPA-2200, 40% mat/60% resin). Methyl ethyl ketone peroxide
(MEKP) co-initiator at 1.2 wt % is used to cure the polyester
resin. The laminate is allowed to cure for 16-20 hours at room
temperature and 5 hours at 100.degree. C., then removed from the
mold and cut into test parts.
Examples 15 to 21
Preparation of Clear Castings
[0092] Clear castings were prepared by mixing the resin, acrylate,
and catalyst listed in Table 1 (below) by hand and pouring the
resin mixture into a cavity between two glass plates with 1/8''
spacing. The resin was cured at ambient temperature overnight and
post-cured at 100.degree. C. for 5 hours. The cured resins were
tested for physical properties according to ASTM D638, D648, and
D790. The results are listed in Table 1.
TABLE-US-00002 TABLE 1 Physical properties of clear casting of
resin Example 15 16 17 18 19 Resin, weight (g) Ex 1, 100 Ex 1, 100
Ex 1, 55 Ex 2, 162 Ex 4, 132 Acrylate, weight (g) TMPTA, SR355,
SR368, 48 TMPTA, TMPTA, 100 100 SR454, 76 124 143 g TMPTA, 55
Catalyst, weight (g) TMG, 0.7 DBU, 0.7 Ex 10, 3.6 Ex 9, 2.3 Ex 9,
2.3 Viscosity (cp) 95 310 1000 1000 900 Mechanical Properties
Tensile Strength (psi) 7500 6680 10460 10760 6510 Tensile Modulus
(ksi) 451 449 514 509 420 Elongation (%) 2.3 1.9 3.2 3.9 1.7 Flex
Strength (psi) 13730 12610 17270 18130 16700 Flex Modulus (ksi) 432
438 488 510 477 HDT (.degree. C.) 62 48 70 77 86 Example 20 21
Resin, weight (g) Ex 5, 165 Ex 1, 150 Ex 6, 68 Acrylate, weight (g)
TMPTA TMPTA 113 184 Catalyst, weight (g) Ex 9, 2.4 Ex 9, 2.3
Viscosity (cps) -- 340 Mechanical Properties Tensile Strength (psi)
8720 8840 Tensile Modulus (ksi) 456 468 Elongation (%) 4.3 3.6 Flex
Strength (psi) 8600 1510 Flex Modulus (ksi) 318 433 HDT (.degree.
C.) 34 69
[0093] The mechanical properties of the examples have comparable
properties to typical unsaturated polyester resins.
[0094] The invention has been described by reference to detailed
examples and methodologies. These examples are not meant to limit
the scope of the invention. It should be understood that variations
and modifications may be made while remaining within the spirit and
scope of the invention, and the invention is not to be construed as
limited to the specific embodiments disclosed. The disclosures of
references cited in the application are incorporated by reference
herein.
* * * * *