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Claims  |
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What is claimed is:
1. A substantially anhydrous, acid-free, room temperature curable
composition which comprises (A) an organic thermoplastic polymer
containing at least two hydroxyl radicals which are directly bonded to
non-carboxylic carbon atoms of said polymer; and (B) a hydrolyzable
aminosilicon compound selected from the class consisting of aminosilicon
compounds having the average formula
##STR14##
and mixtures thereof wherein: X is an alkoxy radical having 1 to 6 carbon
atoms; R is a divalent alkylene radical having 1 to 4 carbon atoms;
R.sup.1 is hydrogen or an alkyl radical having 1 to 4 carbon atoms,
R.sup.2 is a radical selected from the group consisting of hydrogen, an
alkyl radical having 1 to 4 carbon atoms and a silyl radical of the
formula
##STR15##
wherein R, R.sup.1, and X are the same as defined above; and wherein
R.sup.3 is a divalent alkylene radical having 2 to 4 carbon atoms; a has a
value of 0 to 2 and t has a value of 0 to 4; and wherein said composition
contains about 5 to 50 parts by weight of said hydrolyzable aminosilicon
compound (B) per 100 parts by weight of said organic polymer (A).
2. A composition as defined in claim 1 wherein X is an alkoxy radical
selected from the group consisting of methoxy, ethoxy and 2-methoxyethoxy,
wherein R and R.sup.3 are divalent alkylene radicals selected from the
group consisting of ethylene and propylene, and wherein a is 0.
3. A composition as defined in claim 2 wherein t is 0.
4. A composition as defined in claim 2 wherein t is 1.
5. A composition as defined in claim 4, wherein R is a propylene radical
and R.sup.3 is an ethylene radical.
6. A composition as defined in claim 5 wherein each R.sup.2 is individually
selected from the group consisting of hydrogen, and a silyl radical of the
formula
--(CH.sub.2).sub.3 Si-X.sub.3
7. A composition as defined in claim 6 wherein X is a methoxy radical.
8. A composition as defined in claim 7 wherein the aminosilicon compound is
a mixture of said aminosilicon compounds.
9. A composition as defined in claim 3, wherein X is an ethoxy radical, R
is a propylene radical and each R.sup.2 is individually selected from the
group consisting of hydrogen and a silyl radical of the formula
--(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3
10. A composition as defined in claim 1 wherein the organic thermoplastic
polymer is selected from the class consisting of a hydroxylalkyl acrylate
modified vinyl chloride polymer, a polyether polyol polymer, a polyhydroxy
containing acrylate polymer, a polyvinyl alcohol polymer, a polyhydroxy
containing polyvinyl acetal polymer, a polyester polyol polymer, a
phenolic resin polymer, and mixtures thereof.
11. A composition as defined in claim 10, wherein X is an alkoxy radical
selected from the group consisting of methoxy, ethoxy, and
2-methoxyethoxy, wherein R and R.sup.3 are divalent alkylene radicals
selected from the group consisting of ethylene and propylene, wherein a is
0, t is 1 and wherein each R.sup.2 is individually selected from the group
consisting of hydrogen and a silyl radical of the formula
--RSiX.sub.3
12. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a hydroxyalkyl acrylate modified vinyl chloride polymer.
13. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a polyether polyol polymer.
14. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a polyhydroxy containing polyvinyl acetal polymer.
15. A composition as defined in claim 11 wherein the organic thermoplastic
polymer is a polyhydroxy containing acrylate polymer.
16. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a polyvinyl alcohol polymer.
17. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a polyester polyol polymer.
18. A composition as defined in claim 11, wherein the organic thermoplastic
polymer is a phenolic resin polymer.
19. A composition as defined in claim 11, wherein R is a propylene radical,
R.sup.3 is an ethylene radical, X is methoxy and wherein the aminosilicon
compound is a mixture of said aminosilicon compounds.
20. A composition as defined in claim 1, wherein said composition contains
about 10 to about 40 parts by weight of said hydrolyzable aminosilicon
compound (B) per 100 parts by weight of said organic polymer (A).
21. A composition as defined in claim 1 wherein an alkylsilicate is present
as an additional ingredient.
22. A composition as defined in claim 21, wherein the alkyl silicate is
tetraethyl orthosilicate.
23. A composition as defined in claim 10 which also contains an organic
solvent in an amount sufficient to dissolve the organic polymer employed;
about 70 to 100 parts by weight of a pigment per 100 parts by weight of
said organic polymer; 0 to about 70 parts by weight of a filler material
per 100 parts by weight of said organic polymer; 0 to about 25 parts by
weight of an alkyl silicate; and based on the total weight of the
composition 0 to about 1 percent by weight of a dispersing agent for said
pigment and 0 to about 3 percent by weight of a dessicant material.
24. A composition as defined in claim 23, wherein X is an alkoxy radical
selected from the group consisting of methoxy, ethoxy and 2-methoxyethoxy,
wherein R and R.sup.3 are divalent alkylene radicals selected from the
group consisting of ethylene and propylene, wherein a is 0, t is 1 and
wherein each R.sup.2 is individually selected from the group consisting of
hydrogen and a silyl radical of the formula
--RSiX.sub.3.
25. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a hydroxyalkyl acrylate modified vinyl chloride polymer.
26. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a polyether polyol polymer.
27. A composition as defined in claim 26, wherein the polyether polyol
polymer is a phenoxy resin.
28. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a polyhydroxy containing polyvinyl acetal polymer.
29. A composition as defined in claim 28 wherein the polyhydroxy containing
polyvinyl acetal polymer is a polyvinylbutyral resin.
30. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a polyhydroxy containing acrylate polymer.
31. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a polyvinyl alcohol polymer.
32. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a polyester polyol polymer.
33. A composition as defined in claim 24, wherein the organic thermoplastic
polymer is a phenolic resin polymer.
34. A composition as defined in claim 25, wherein R is a propylene radical,
R.sup.3 is an ethylene radical, X is methoxy and wherein the aminosilicon
compound is a mixture of said aminosilicon compounds.
35. A composition as defined in claim 23, wherein said composition contains
about 10 to about 40 parts by weight of said hydrolyzable aminosilicon
compound (B) per 100 parts by weight of said organic polymer (A).
36. A composition as defined in claim 23, wherein the pigment is titanium
dioxide.
37. A composition as defined in claim 25, wherein the organic polymer
contains (a) from about 50 to about 85 weight percent of vinyl chloride
derived mer units, (b) from about 0 to 10 weight percent mer units derived
from a polymerizable monomer selected from the class consisting of alkyl
esters of alpha, beta-ethylenically unsaturated carboxylic acids and vinyl
esters of saturated fatty acids, and (c) from 10 to 30 percent mer units
derived from hydroxyalkyl acrylate.
38. A composition as defined in claim 37, wherein the organic polymer is a
hydroxy-functional random terpolymer containing about 80 weight percent
vinyl chloride mer units, about 5 weight percent vinyl acetate mer units
and about 15 weight percent hydroxypropyl acrylate mer units.
39. A composition as defined in claim 38, wherein said composition contains
about 10 to about 40 parts by weight of said hydrolyzable aminosilicon
compound (B) per 100 parts by weight of said organic polymer (A).
40. A composition as defined in claim 39, wherein the pigment is titanium
dioxide.
41. The crosslinked polymer product obtained upon crosslinking the
composition of claim 1. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
This invention relates to novel room temperature curable compositions
comprising a hydroxyl containing organic thermoplastic polymer and an
aminosilicon compound, as well as to the crosslinked products derived from
said compositions.
The employment of organosilanes to aid in the crosslinking of polymeric
materials is well known in the art. However, heretofore in order to obtain
room temperature curable compositions the prior art has had to prereact
the starting organic polymer with the organosilane at elevated
temperatures. One exception to such methods has been the use of
halosilanes which are known to react at room temperature with hydroxyl
containing polymers, however, this procedure has the disadvantage of also
producing an undesirable acid by-product, e.g. hydrogen chloride, which if
not removed may have a deleterious effect on the performance of the cured
composition.
SUMMARY OF THE INVENTION
It has now been discovered that room temperature curable polymer
compositions can also be easily prepared at room temperature by simply
mixing a hydroxyl containing organic thermoplastic polymer with certain
hydrolyzable aminosilicon compounds without also resulting in undesirable
by-products.
Thus, it is an object of this invention to provide room temperature curable
compositions comprising a hydroxyl containing organic thermoplastic
polymer and a hydrolyzable aminosilicon compound. It is another object of
this invention to provide cured crosslinked products, e.g. solvent
resistant coatings, derived from the curable compositions of this
invention. Other objects and advantages of this invention will become
readily apparent from the following description and appended claims.
More specifically one aspect of this invention may be described as a
substantially anhydrous, acid-free, room temperature curable composition
which comprises (A) an organic thermoplastic polymer containing at least
two hydroxyl radicals which are directly bonded to noncarboxylic carbon
atoms of said polymer; and (B) a hydrolyzable aminosilicon compound
selected from the class consisting of aminosilicon compounds having the
formula
##STR1##
and mixtures thereof wherein:
X is an alkoxy radical having 1 to 6 carbon atoms; R is a divalent alkylene
radical having 1 to 4 carbon atoms; R.sup.1 is hydrogen or an alkyl
radical having 1 to 4 carbon atoms; R.sup.2 is a radical selected from the
group consisting of hydrogen, an alkyl radical having 1 to 4 carbon atoms
and a silyl radical of the formula
##STR2##
wherein R, R.sup.1, and X are the same as defined above; R.sup.3 is a
divalent alkylene radical having 2 to 4 carbon atoms; a has a value of 0
to 2; t has a value of 0 to 4; and wherein said composition contains about
5 to 50 parts by weight of said hydrolyzable aminosilicon compound (B) per
100 parts by weight of said organic polymer (A).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Any hydroxyl containing organic thermoplastic polymer having at least two
hydroxyl radicals which are directly bonded to non-carboxylic
##STR3##
carbon atoms can be employed as the organic polymer component of the room
temperature (i.e. ambient) curable compositions of this invention. Such
types of hydroxyl containing organic polymers and/or methods for their
preparation are well known in the polymer art. Of course it is to be
understood that the hydroxyl containing organic thermoplastic polymers
employable in this invention include homopolymers, copolymers, terpolymers
and the like and that mixtures of more than one type or class of polymers
can be employed if desired. Likewise, it is to be understood that the
particular proportions of polymer units and molecular weights of the
hydroxy containing organic thermoplastic polymer components of this
invention are not generally critical to the invention. Illustrative
examples of such hydroxyl containing organic thermoplastic polymers
include:
(a) Hydroxyalkyl acrylate modified vinyl chloride polymers such as the
uniformly random hydroxyl-functional copolymers or terpolymers of (i)
vinyl chloride; (ii) hydroxyalkyl acrylate having 2 to 4 carbons in the
alkyl segment; and, optionally, (iii) a polymerizable monomer chosen from
alkyl (1-8 carbon) esters of polymerizable alpha, beta-ethylenically
unsaturated acids such as acrylic, methacrylic, maleic, fumaric, itaconic
and the like, and vinyl esters of saturated fatty acids of 1-6 carbon
atoms, such as vinyl acetate, vinyl propionate and the like. Suitable
hydroxyl-functional copolymers and terpolymers are described in U.S. Pat.
No. 3,884,887 and U.S. Pat. No. 3,755,271.
(b) Polyether polyol polymers such as the alkylene oxide adducts of water
or a polyhydric organic compound as the initiator or starter, e.g.
illustrative initiators which may be used individually or in combination
include ethylene glycol; diethylene glycol; propylene glycol;
1,5-pentanediol; hexylene glycol; dipropylene glycol; trimethylene glycol;
1,2-cyclohexanediol; 3-cyclohexane-1,1-dimethanol and dibromo-derivative
thereof; glycerol; 1,2,6-hexanetriol; 1,1,1-trimethyolethane;
1,1,1-trimethyolpropane; 3-(2-hydroxyethoxy)-and
3-(2-hydroxypropoxy)-1,3-propanediols;
2,4-dimethyl-2-(2-hydroxyethoxy)methylpentanediol-1,5;
1,1,1-tris[2-hydroxyethoxy)methyl]ethane;
1,1,1-tris[2-hydroxypropoxy)methyl]propane; pentaerythritol; sorbitol;
sucrose; alphamethyl glucoside; and other such polyhydric compounds
consisting of carbon, hydrogen and oxygen and having usually not more than
about 15 carbon atoms per molecule. Illustrative alkylene oxides include
ethylene oxide, propylene oxide, butylene oxide as well as various
mixtures of such oxides. Also included among the polyether polyol polymers
useful herein are poly(hydroxyethers) derived from diphenols and
epichlorohydrin, e.g. phenoxy resins, as well as those polymers commonly
referred to in the art as polymer/polyether polyols which may be produced
by polymerizing one or more ethylenically unsaturated monomers dissolved
or dispersed in any of the above described alkylene oxide adduct polyols.
Illustrative of such unsaturated monomers which may be employed
individually or in combination include ethylene, propylene, acrylonitrile,
methacrylonitrile, vinyl chloride, vinylidene chloride, styrene,
alpha-methylstyrene, butadiene, and the like.
(c) Polyhydroxy containing acrylic polymers such as the copolymers and
terpolymers of hydroxyalkyl acrylates having 2 to 4 carbon atoms in the
alkyl segments and alkyl acrylates and/or alkyl methacrylates having 1 to
6 carbon atoms in the alkyl segments.
(d) Polyvinyl alcohol polymers such as the hydrolyzed or partially
hydrolyzed polymers derived from the homopolymers of vinyl esters of
saturated fatty acids of 1-6 carbon atoms or the copolymers of said vinyl
esters and one or more ethylenically unsaturated monomers such as
ethylene, propylene, butylene, acrylonitrile, methacrylonitrile, vinyl
chloride, vinylidene chloride, styrene, alpha-methylstyrene, butadiene,
and the like.
(e) Polyhydroxy containing polyvinyl acetal polymers such as
polyvinylbutyral resins and the like.
(f) Polyester polyol polymers such as the reaction products of
polyfunctional organic carboxylic acids and polyhydric alcohols, which
reaction products contain at least two hydroxyl groups (as alcoholic OH)
per molecule, and cyclic ester polymers containing at least two hydroxyl
groups per molecule prepared from epsilon caprolactone or other lactones
and the copolymers of such lactones with polyhydric alcohols.
Typical of the polyfunctional organic carboxylic acids that can be employed
in producing polyester polyols useful in this invention are: dicarboxylic
aliphatic acids such as succinic, adipic, sebacic, azelaic, glutaric,
pimelic, malonic and suberic acids; and dicarboxylic aromatic acids such
as phthalic acid, terephthalic acid, isophthalic acid and the like. Other
polycarboxylic acids that can be employed are the "dimer acids" such as
the dimer of linoleic acid. Hydroxyl-containing monocarboxylic acids (such
as ricinoleic acid) can also be used. Alternatively, the anhydrides of any
of these various acids can be employed in producing the polyester polyols.
The polyhydric alcohols (organic polyols) that can be employed in producing
the polyester polyol starting material useful in this invention include
the monomeric polyhydric alcohols such as, for example, glycerol;
1,2,6-hexanetriol; ethylene glycol; diethylene glycol; trimethylol
propane; trimethyolethane; pentaerythritol; propylene glycol; 1,2-, 1,3-
and 1,4-butylene glycols; 1,5-pentanediol; sorbitol; and the like,
including mixtures thereof.
Other polyhydric alcohols that can be employed in producing the polyester
polyols useful in this invention are the polymeric polyhydric alcohols
which include the linear and branched chain polyethers having a plurality
of acyclic ether oxygens and at least two alcoholic hydroxyl radicals.
Illustrative of such polyether polyols are the poly(oxyalkylene) polyols
containing one or more chains of connected oxyalkylene radicals which are
prepared by the reaction of one or more alkylene oxides with acyclic and
alicyclic polyols. Examples of the poly(oxyalkylene) polyols include the
poly(oxyethylene) glycols prepared by the addition of ethylene oxide to
water, ethylene glycol or diethylene glycol; poly(oxypropylene) glycols
prepared by the addition of propylene oxide to water, propylene glycol or
dipropylene glycol; mixed oxyethylene-oxypropylene polyglycols prepared in
a similar manner utilizing a mixture of ethylene oxide or a sequential
addition of ethylene oxide and propylene oxide; and the poly(oxybutylene)
glycols and copolymers such as poly(oxyethylene-oxybutylene) glycols and
poly(oxypropylene-oxybutylene) glycols. Included in the term
"poly(oxybutylene) glycols" are polymers of 1,2-butyleneoxide and
2,3-butyleneoxide.
Illustrative of further polyester polyols are the reaction products of any
of the aforesaid polycarboxylic acids and the polyhydric alcohols prepared
by the reaction of one or more alkylene oxides such as ethylene oxide,
propylene oxide, butylene oxide and mixtures thereof, with any of the
following: glycerol; trimethylolpropane, 1,2,6-hexanetriol;
pentaerythritol; sorbitol; glycosides such as methyl, ethyl, propyl, butyl
and 2-ethylhexyl arabinoside, xyloside, fructoside, glucoside, and
rhammoside; sucrose; mononuclear polyhydroxybenzenes such as resorcinol,
pyrogallol, phloroglucinol, hydroquinone, 4,6-di-tertiarybutylcatechol,
and catechol; polynuclear hydroxybenzenes ("polynuclear" designating at
least two benzene nuclei) such as the di-, tri- and tetraphenylol
compounds in which two to four hydroxybenzene groups are attached either
directly by means of single bonds or through an aliphatic hydrocarbon
radical containing one to twelve carbon atoms, such compounds being
typically illustrated by 2,2-bis(p-hydroxyphenyl)-propane,
bis(p-hydroxyphenyl)-methane and the various diphenols and diphenol
methanes disclosed in U.S. Pat. Nos. 2,506,486 and 2,744,882,
respectively. Another type of polyester polyol is that produced by
reaction of a polycarboxylic acid and the polyether adducts formed by
reaction of ethylene oxide, propylene oxide or butylene oxide with
phenol-formaldehyde condensation products such as the novolaks.
(g) Phenolic resin polymers such as the solid resoles and novolak resins
disclosed in copending U.S. Application Ser. No. 765,300 filed Feb. 3,
1977, U.S. Pat. No. 4,116,921 and British Pat. No. 1,417,437. The phenol
of the resin can be unsubstituted phenol or substituted such as cresol,
bisphenol-A, para-substituted phenols and the like while formaldehyde or a
material that generates formaldehyde in situ is the aldehyde employed in
making phenol resins. The preferred phenolic resins are resoles produced
by reacting formaldehyde with bisphenol-A at elevated temperatures in the
presence of a base-catalyst and having a neutralized pH of about 3 to 8.
The preferred hydroxyl containing organic thermoplastic polymer components
of this invention are the hydroxylalkyl acrylate modified vinyl chloride
polymers described above having (a) from about 50 to 85 weight percent
vinyl chloride derived per units; (b) from 0 to 10 weight percent mer
units derived from a polymerizable monomer selected from the class
consisting of alkyl esters of alpha, beta-ethylenically unsaturated
carboxylic acids as described above and vinyl esters of saturated fatty
acids as described above, the preferred polymerizable monomer being vinyl
acetate, and (c) from 10 to 30 weight percent mer units derived from
hydroxyalkyl acrylate as described above, preferably hydroxypropyl
acrylate. The most preferred polymer being a uniformly hydroxyl-functional
random terpolymer of about 80 weight percent vinyl chloride mer units,
about 5 weight percent vinyl acetate mer units and about 15 weight percent
hydroxypropyl acrylate mer units.
With regard to the aminosilicon compounds and mixtures thereof of Formula I
above it is to be understood that each X, R, R.sup.1, R.sup.2, R.sup.3, a
and t may be the same or different in any given aminosilicon compound and
mixtures thereof. Moreover, illustrative radicals represented by X above
include alkoxy radicals having 1 to 6 carbon atoms, such as methoxy,
ethoxy, propoxy, 2-methoxyethoxy, isopropoxy, hexyloxy and the like, the
preferred alkoxy radicals being methoxy, ethoxy and 2-methoxyethoxy.
Illustrative divalent alkylene radicals represented by R above include
methylene, ethylene, propylene, isopropylene, butylene and the like, the
preferred divalent alkylene groups being ethylene (--C.sub.2 H.sub.4 --)
and propylene (--C.sub.3 H.sub.6 --). Illustrative radicals represented by
R.sup.1 above include alkyl radicals such as methyl, ethyl, propyl,
isopropyl, butyl and the like. Illustrative radicals represented by
R.sup.2 above include hydrogen, alkyl radicals such as methyl, ethyl,
propyl, isopropyl, butyl and the like, as well as silyl groups of the
formula
##STR4##
wherein R, R.sup.1, X and a are the same as defined above. In those
aminosilicon compounds of Formula (I) that contain only one silicon atom
R.sup.2 is preferbly hydrogen. Illustrative divalent alkylene groups
represented by R.sup.3 above include ethylene, propylene, isopropylene,
butylene, and the like, the preferred divalent alkylene groups being
ethylene and propylene. In the more preferred organosilicon compounds a is
preferably 0 and t is preferably 1.
Illustrative aminosilicon compounds that may be employed in this invention
include, for example
(CH.sub.3 O).sub.3 SiCH.sub.2 NH.sub.2
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NHCH.sub.3
(C.sub.3 H.sub.7 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
(CH.sub.3 OC.sub.2 H.sub.4 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
(C.sub.2 H.sub.5 O).sub.2 CH.sub.3 Si(CH.sub.2).sub.3 NH.sub.2
(C.sub.2 H.sub.5 O).sub.2 C.sub.2 H.sub.5 Si(CH.sub.2).sub.3 NH.sub.2
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.2 NH.sub.2
(C.sub.2 H.sub.5 O).sub.3 SiCH.sub.2 CH.sub.2 CH(CH.sub.3)NH.sub.2
(C.sub.2 H.sub.5)).sub.3 Si(CH.sub.2).sub.4 NH.sub.2
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2(.sub.2 NH.sub.2
(C.sub.4 H.sub.9)).sub.2 (CH.sub.3)Si(CH.sub.2).sub.3 NHCH.sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 N(C.sub.2 H.sub.5).sub.2
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 (NHC.sub.2 H.sub.4).sub.2 NH.sub.2
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 (NHC.sub.2 H.sub.4).sub.3 NH.sub.2
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.3 Si(OC.sub.2
H.sub.5).sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2 NH(CH.sub.2).sub.3
Si(OCH.sub.3).sub.3 (C.sub.22 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3
N[(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3](CH.sub.2).sub.3 Si(OC.sub.2
H.sub.5).sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 [NH(CH.sub.2).sub.2 ].sub.2
NH(CH.sub.2).sub.3 Si (OCH.sub.3).sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3[NH(CH.sub.2).sub.2 ].sub.3
NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2 N[(CH.sub.2).sub.3
Si(OCH.sub.3).sub.3 ](CH.sub.2).sub.3 Si(OCH.sub.3).sub.3
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 N[(CH.sub.2).sub.3
Si(OCH.sub.3).sub.3 ](CH.sub.2).sub.2 N[(CH.sub.2).sub.3
Si(OCH.sub.3).sub.3 ](CH.sub.2).sub.3 Si(OCH.sub.3).sub.3
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2
NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3
(CH.sub.3 OC.sub.2 H.sub.4 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2
NH(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.4 OCH.sub.3).sub.3
and the like, as well as mixtures thereof.
The aminosilicon compounds and mixtures of Formula (I) above which can be
used as the silicon component of the compositions of this invention are
also well known in the art as are methods for their preparation. Thus,
with regard to the aminosilicon compounds and mixtures thereof employable
in this invention it is to be understood that while a single type of
aminosilicon compound or mixtures of various combinations of different
aminosilicon compounds can be used, it is not necessary to form said
mixtures by combining individually isolated aminosilicon compounds,
although such may be done if desired. For example, it is well known in the
art that aminosilicon compounds such as the polyamino silanes and multiple
silylated aminosilicon compounds of Formula (I) above are normally
produced in the form of a mixture consisting essentially of different
types of such aminosilicon compounds of Formula I above due to the manner
in which they are generally prepared. For instance, in the conventional
reactions employed to produce polyaminoalkylene silanes or multiple
silylated polyaminoalkylene compounds, e.g. by the reaction of an
alkylenediamine and a haloalkyl silane or by the reaction of an
aminoalkyleneaminoalkylene silane and a haloalkyl silane, in addition to
the desired product, the crude reaction product can be expected to consist
of a mixture of symmetrical and unsymmetrical bis, tris and tetrakis silyl
compounds, and the like, due to the multiple amino reaction sites on the
amino starting material. Accordingly, included within the definition of
the aminosilicon compounds that can be employed in the compositions of
this invention are such crude aminosilicon compound reaction products that
contain more than one amino group and/or silyl group as shown by Formula
(I) above. Indeed, since the more preferred aminosilicon compounds
employable in this invention are those containing more than one amino
group and/or more than one silyl group it is generally preferred to employ
the crude reaction product mixture obtained upon producing the type of
aminosilicon compound that one wishes to use in the particular composition
of this invention desired for a particular end result, since such
eliminates the time and effort caused by additional procedural steps
necessary in preparing and isolting any particular singular aminosilicon
compound prior to its use herein.
Accordingly, the more preferred aminosilicon compounds employable in this
invention are those of Formula (I) above wherein at least one R.sup.2
group represents a silyl radical of the formula
##STR5##
and mixtures thereof, wherein R, R.sup.1 and a are the same as defined
above, e.g. (CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2
NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3.
Moreover, due to the fact that the present invention allows for the use of
the crude reaction product mixtures of said preferred aminosilicon
compounds produced by either above described conventional procedures
thereby rendering it unnecessary to obtain a single species of the desired
aminosilicon compound, the more preferred aminosilicon compound component
of this invention is a crude aminosilicon reaction product mixture having
an average empirical mole ratio of the following structural units
##STR6##
wherein R, R.sup.1, R.sup.3, a, and t are the same as defined above, with
R.sup.1 preferably being a hydrogen radical, t preferably having a value
of 1 to 2 and a preferably being 0; while x has a value of 0 to 6
preferably 1 to 4, y has a value of 1 to 6, preferably 2 to 5; the sum of
x+y being a value of 3 to 6, preferably 4 to 5. Of course it is understood
that said structural units (A) and (C) are both directly bonded to said
structural unit (B) thereby satisfying all of the free valences of said
structural units (A), (B) and (C).
The most preferred aminosilicon compound employable in the composition of
this invention is a crude aminosilicon reaction product mixture having an
average empirical mole ratio of the following structural units
##STR7##
wherein x has a value of 0 to 3; y has a value of 1 to 4, preferably 2 to
4; the sum of x+y being 4; said structural units (A) and (C) both being
directly bonded to said structural unit (B) thereby satisfying all of the
free valances of said structural units (A), (B) and (C).
The hydroxyl-containing organic polymer-aminosilicon compositions of this
invention are uniformly blended solutions containing about 5 to about 50
parts by weight, and more preferably about 10 to about 40 parts by weight
of the aminosilicon compound per 100 parts by weight of the organic
polymer, and can be prepared by merely mechanically mixing said
ingredients together along with other various conventional components that
may be included if desired in the room temperature curable compositions.
The particular design of mixing equipment and the method and order of the
various components is not critical, although it is preferred to add the
aminosilicon compound to a solution of the organic polymer and additional
ingredients when employed. In addition since the compositions of this
invention are reactive in the presence of water the mixing of the various
components should be conducted under substantially anhydrous type
conditions, such as closing the equipment so that the ambient atmosphere
can be controlled. Moreover, since the compositions of this invention are
mildly basic in nature, it is desirable to exclude or control their
contact with any acidic or potentially acidic environmental components
such as SO.sub.2, CO.sub.2, or HCl which may be in the atmosphere. It may
also be desirable to dry or dehydrate any additional components which are
added.
As indicated above the compositions of this invention may also contain
additional components so long as they and/or their amounts would not
destroy the basic concept of this invention such as alkyl silicates to
increase the solids content of the cured composition without increasing
the viscosity of the curable composition, fillers, pigments, dyestuffs,
diluents, solvents, dispersing agents, dessicants such as molecular
sieves, odorants, plasticizers, softeners, elastomeric modifiers, thermal
stabilizers, antioxidants, and the like. The particular choice and amount
of such additives when employed will of course merely depend on the
ultimate end use desired for the compositions of this invention.
The hydroxyl-containing organic polymer-aminosilicon compositions of this
invention have a wide variety of utility such as in the fields of
coatings, laquers, paints, inks, dyes, tints, impregnations, adhesives,
caulks, sealants and the like. Said compositions are especially useful as
room temperature curable coating compositions which may be applied over a
wide variety of substrates, such as metals, plastics, wood, cloth, foam,
glass, and the like, as well as over primers, by any conventional method
such as by spraying, brushing, dipping, flow coating, and the like. Said
compositions are particularly useful in all fields of use where cured
(crosslinked) protective and/or decorative solvent resistant coatings are
desired, such as in the fields of maintenance and marine coatings.
For example, the compositions of this invention when kept anhydrous have
been found to provide excellent protective and solvent resistant cured
coatings for metals merely by air drying the curable coating compositions
at room (ambient) temperature after it has been applied to the metal.
Normally, the ambient moisture in the air is sufficient to cure
(crosslink) the coating into a dry, hard corrosion and solvent resistant
protective film on the metal. The curable composition generally becomes
dry very quickly and cured coatings having excellent properties have been
achieved within 24 hours after coating the substrate. Of course, it is to
be understood that the curing may be accelerated, if desired, by the
employment of elevated temperatures. In addition to the surprisingly
excellent solvent resistance of the cured compositions of this invention
such cured coatings have also been found to have good impact strength,
weatherability and environmental resistance as exhibited by their good
stability against salt sprays, and against chalking on exposure to
sunlight, as well as their resistance to deterioration, corrosion and
blistering upon being immersed in both fresh water and seawater for
prolonged periods of time. Of course it is to be understood that the
ultimate properties of any given room temperature curable coating
composition will depend upon such obvious factors as the various
ingredients employed, their concentrations, the crosslinked density of the
final composition, and the like. However, the optimum results desired for
any composition is well within the bounds of routine experimentation.
While not wishing to be bound by any particular theory of mechanism
involved, it is believed that the aminosilicon compound reacts with the
polymer via transesterification followed by hydrolysis of the silane
portion. Experiments have indicated that the aminosilicon compound is
bound to the hydroxyl containing polymer through an Si-O-C bound via
transesterification which then upon exposure to the ambient moisture in
the air hydrolyzes and cures (crosslinks) into a solid film.
The most preferred coating composition of this invention are those
consisting essentially of a hydroxyalkyl acrylate modified vinyl chloride
polymer as defined above and a hydrolyzable aminosilicon compound or
mixtures thereof as defined above, said composition containing about 5 to
50 and more preferably about 10 to 40 parts by weight of said silicon
compound per 100 parts by weight of said polymer. Said preferred
composition may also and more often preferably contains the following
additional additives such as an organic solvent in an amount sufficient to
dissolve the polymer employed; about 70 to 100 parts by weight of a
pigment per 100 parts by weight of said polymer; 0 to about 70 parts by
weight of a filler material per 100 parts by weight of said polymer; 0 to
about 25 parts by weight of an alkyl silicate per 100 parts by weight of
said polymer; and based on the total weight of the composition, 0 to about
1 percent by weight of a dispersing agent for the pigment and 0 to about 3
percent by weight of a dessicant. The most preferred hydroxyalkyl acrylate
modified vinyl chloride polymers and aminosilicon compounds useful in this
invention have already been defined above. In general a typical coating
composition will consist of about 10 to 35 percent by weight of said
hydroxyalkyl acrylate modified vinyl chloride polymer based on the total
weight of the composition. Of course, it is obvious that the particular
additives employed are not critical and any suitable solvent, pigment,
filler, alkyl silicate, dispersing agent and dessicant can be employed. In
general, the preferred solvents are methylisobutyl ketone, xylene and
mixtures thereof, while the preferred pigment is titanium dioxide and the
preferred dessicant is molecular sieves.
The alkyl silicates are also well known in the art and include unhydrolyzed
alkyl and alkoxyalkyl silicates and alkyl and alkoxyalkyl silicates
hydrolyzed up to about 85 percent by weight. Alkyl silicates are produced
by the reaction of silicon tetrachloride and alcohols and alkoxy alcohols,
generally in a reactor equipped with a stirrer, condenser and vat
scrubber. The hydrogen chloride by-product is removed by reflux which may
be carried out at reduced or atmospheric pressure. Through this process,
the most common products TEOS (tetraethyl orthosilicate), and Cellosolve
(Trademark of the Union Carbide Corporation for monoalkyl ethers of
ethylene glycol) silicate are made. Subsequently, these products may be
partially hyrolyzed by the addition of water and an acid catalyst. The
amount of water added determines the degree of hydrolysis in the final
product. Commercially available products derived from ethanol include the
unhydrolyzed TEOS, Condensed Ethyl Silicate (about 7 percent hydrolysis),
Ethyl Silicate 40 (40 percent hydrolysis containing 40% SiO.sub.2), and
Ethyl Silicate P-18, having an 80 to 85 percent hydrolysis level.
The following examples illustrate the present invention and are not to be
regarded as limitative. All parts and percentages are by weight unless
otherwise specified.
For the sake of brevity in the Examples, the designations in the first
column of Table I will be used in lieu of the complete description given
in the second column.
TABLE I
______________________________________
Designation
Composition
______________________________________
Polymer A A uniformly random hydroxyl-functional
terpolymer of 80% vinyl chloride mer
units, 5% vinyl acetate mer units and
15% hydroxylpropyl acrylate mer units.
Inherent viscosity is 0.3.
Polymer B A partially hydrolyzed polyvinyl alcohol
terpolymer of 91% vinyl chloride mer
units, 3% vinyl acetate mer units and
6% vinyl alcohol mer units. Viscosity
is 60 cps (20% resin in methyl ethyl
ketone). Sold by Union Carbide Corpor-
ation under the product designation VAGH.
Polymer C A thermoplastic polyhydroxyether phenoxy
resin polymer having a specific gravity of
1.18 and sold by Union Carbide Corporation
under the product designation PKHH.
Polymer D A bisphenol A-formaldehyde phenolic resin
containing approximately 16% methylol
groups, sold by Union Carbide Corporation
under the product designation BK-5918.
Polymer E A polyhydroxyl containing acrylate polymer
sold by Rohm & Haas under the product
designation Acryloid AT-56.
Polymer F A polyvinyl butyral resin polymer contain-
ing 1% vinyl acetate mer unite and 20%
vinyl alcohol mer units having an Inherent
viscosity of 0.90 and sold by Union Carbide
Corporation under the product designation
XYHL.
Nuosperse.RTM. 657
A dispersing agent supplied by
Tenneco, Inc.
ES-40 A partially hydrolyzed ethyl poly-
silicate containing 40 percent by
weight of SiO.sub.2.
TEOS Unhydrolyzed tetraethyl orthosilicate.
Silane A A commercial grade silane designated as
N-beta-(Aminoethyl)-gamma-aminopropyl-
trimethoxy-silane sold under the pro-
duct name A-1120 by Union Carbide
Corporation.
Silane B A silane having the formula
(C.sub.2 H.sub.5 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
Silane C The crude aminosilane reaction
product mixture of Example A of this
application.
Silane D A silane having the formula
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH(CH.sub.2).sub.2
NH.sub.2
distilled from Silane A
Silane E A silane having the formula
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2
Silane F A silane having the formula
(CH.sub.3 O).sub.3 SiCH.sub.2 CH.sub.2 Si(OCH.sub.3).sub.3
Silane G The crude aminosilane reaction pro-
duct mixture o | | |
