Silyl group-containing vinyl resin and curable composition

A silyl group-containing vinyl resin having a molecular weight of 500 to 100,000, the main chain of which is substantially composed of a vinyl polymer, and which has per one molecule at least one silicon atom to which a hydrolyzable group is bonded, and which has 1 to 95% by weight of units of a monomer selected from the group consisting of an acrylic acid alkyl ester and a methacrylic acid alkyl ester, said alkyl having not less than 10 carbon atoms, which has an excellent abrasion resistance and scratch resistance, and a curable composition containing the silyl group-containing vinyl resin.

BACKGROUND OF THE INVENTION 
The present invention relates to a vinyl resin having improved properties 
and a curable composition containing the vinyl resin, and more 
particularly to a silyl group-containing vinyl copolymer having a 
molecular weight of 500 to 100,000, the main chain of which is 
substantially composed of a vinyl polymer, and which has per one molecule 
at least one silicon atom to which a hydrolyzable group is bonded, and 
which has a monomer selected from the group consisting of an acrylic acid 
alkyl ester and a methacrylic acid alkyl ester, the alkyl having not less 
than 10 carbon atoms. 
Japanese Unexamined Patent Publication (Tokkyo Kokai) No. 36395/1979 
discloses that a vinyl resin including a silyl group having a hydrolyzable 
group at the molecular ends or side chains not only has excellent 
glossiness, weatherability, discoloration resistance, and the like, which 
are characteristics of the vinyl resin itself, but also has an improved 
adhesion resulting from the hydrolyzable silyl group and forms a resin 
having excellent solvent-resistance, water-resistance, heat-resistance and 
weatherability and high hardness by causing a cross-linking reaction with 
water, particularly water in the atmosphere, even at ordinary temperature 
to form a fine network structure. 
The present inventors have found that the properties of the silyl 
group-containing vinyl resin can be extremely improved by copolymerizing 
(meth)acrylic acid alkyl ester having not less than 10 carbon atoms with 
the silyl group-containing vinyl copolymer. 
One of the properties improved by copolymerizing the (meth)acrylic acid 
ester is the abrasion resistance. The above-mentioned silyl 
group-containing vinyl resin is excellent in the abrasion resistance and 
scratch resistance in comparison with other commercially available resins 
since the silyl group-containing vinyl resin can be crosslinked to form a 
fine network structure at ordinary or low temperature or at high 
temperature in a short time in the state of presence or absence of a 
catalyst. 
Furthermore, the inventors have found that the abrasion resistance and the 
scratch resistance are extremely improved when subjecting the 
above-mentioned (meth)acrylic acid alkyl ester to the copolymerization. 
In the present invention, the improvement of the adhesion is a large 
characteristic. 
The silyl group-containing vinyl resin which is disclosed in the above 
publication contains a hydrolyzable silyl group and accordingly, the vinyl 
resin is excellent in the adhesion to an inorganic material as shown in 
case that usual silane coupling reagents are admixed. However, the vinyl 
resin is insufficient in the adhesion to an organic substance. When 
copolymerizing a (meth)acrylic acid higher alkyl ester with the silyl 
group-containing vinyl resin, the adhesion to an inorganic substance is 
further increased and the adhesion to an organic substance is largely 
improved Accordingly, the silyl group-containing vinyl resin of the 
invention can be preferably employed in not only paints, coatings or 
adhesive agents used for inorganic materials but also the top coatings of 
organic materials such as wood, paper, plastic materials and organic 
paints. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there is provided a silyl 
group-containing vinyl resin having a molecular weight of 500 to 100,000, 
the main chain of which is substantially composed of a vinyl polymer, and 
which has per one molecule at least one silicon atom to which a 
hydrolyzable group is bonded, and which has 1 to 95% by weight of units of 
a monomer selected from the group consisting of an acrylic acid alkyl 
ester and a methacrylic acid alkyl ester, the alkyl having not less than 
10 carbon atoms. 
DETAILED DESCRIPTION 
The silyl group-containing vinyl resin of the present invention can be 
prepared by various processes. Among them, (A) a process that a vinyl 
resin having double bonds between carbon atoms and hydrosilane are 
subjected to hydrosilylation, and (B) a process that a vinyl compound and 
a silyl compound having a polymerizable double bond are subjected to 
copolymerization are industrially preferable. 
In the above-mentioned process (A) the silyl group-containing vinyl resin 
of the present invention can be easily prepared by reacting a hydrosilane 
compound with a vinyl resin having units of (meth)acrylic acid ester and 
double bonds between carbon atoms in the presence of a catalyst of a 
transition metal (VIII). 
The hydrosilane compound used in the present invention has the following 
formula: 
##STR1## 
wherein R.sup.1 is a group selected from the group consisting of an alkyl 
group having 1 to 10 carbon atoms, an aryl group having 1 to 10 carbon 
atoms and an aralkyl group having 1 to 10 carbon atoms; X is a group 
selected from the group consisting of a halogen atom, an alkoxy group, an 
acyloxy group, an aminooxy group, a phenoxy group, a thioalkoxy group and 
an amino group, and n is an integer of 1 to 3. 
Examples of the hydrosilane compound shown by the above formula are, for 
instance, halogenated silane compounds such as methyldichlorosilane, 
trichlorosilane and phenyldichlorosilane; alkoxysilane compounds such as 
methyldiethoxysilane, methyldimethoxysilane, phenyldimethoxysilane, 
trimethoxysilane and triethoxysilane; acyloxysilane compounds such as 
methyldiacetoxysilane, phenyldiacetoxysilane and triacetoxysilane and 
other silane compounds such as methyldiaminoxysilane, triaminoxysilane, 
methylaminosilane and triaminosilane, and the like. 
Any amount of the hydrosilane compound can be used against the double bond 
between carbon atoms in the vinyl resin, but it is preferable that the 
amount is 0.5 to 2 moles per mole of the double bond. When the amount is 
more than 2 moles, the hydrosilane compound is not completely reacted with 
the double bond and a little amount of it is left. 
In the present invention the catalyst of a transition metal complex is 
needed for the reaction of the hydrosilane compound and the double bond 
between carbon atoms in the silyl group-containing vinyl resin As the 
catalyst of the transition metal complex, a transition metal complex 
compound (VIII) selected from platinum, rhodium, cobalt, paladium and 
nickel is effectively used. The hydrosilylation reaction is carried out at 
a temperature of 50.degree. to 130.degree. C. for about 1 to about 10 
hours. 
In the present invention, halogenated silanes can be easily used as 
hydrosilane compounds since the halogenated silanes are inexpensive and 
have a high reactivity. When the halogenated silanes are used for the 
preparation of a silyl group-containing vinyl resin, the obtained silyl 
group-containing vinyl resin is rapidly cured at room temperature in air 
while producing hydrogen chloride However, since there are some problems 
as for the irritating odor and the corrosion depending on hydrogen 
chloride, the use of the obtaining silyl group-containing vinyl resin is 
limited Therefore, it is preferable that the halogen atom of the obtained 
silyl group-containing vinyl resin is further converted into other 
hydrolyzable functional group. Examples of the hydrolyzable groups are, 
for instance, an alkoxy group, an acyloxy group, an aminooxy group, a 
phenoxy group, a thioalkoxy group, an amino group, and the like. 
The exemplified methods for converting the halogen atom into the 
above-mentioned hydrolyzable functional group are, for instance, a method 
that alcohols such as methanol, ethanol, 2-methoxyethanol, sec-butanol and 
tert-butanol; phenols such as phenol; salts of alcohols or phenols with 
alkali metal; or alkyl orthoformate such as methyl orthoformate and ethyl 
orthoformate are reacted with the halogen atom. 
The exemplified method for converting the halogen atom into an acyloxy 
group is a method that carboxylic acids such as acetic acid, propionic 
acid and benzoic acid; or salts of carboxylic acid with alkali metal are 
reacted with the halogen atom. 
The exemplified method for converting the halogen atom into an aminooxy 
group is a method that hydroxylamines such as N,N-dimethylhydroxylamine, 
N,N-diethylhydroxylamine, N,N-methylphenylhydroxylamine and 
N-hydroxypyrrolidine; or salts of hydroxylamine with alkali metal are 
reacted with the halogen atom. 
The exemplified method for converting the halogen atom into an amino group 
is a method that primary amines such as pyrrolidine; secondary amines such 
as N,N-dimethylamine or N,N-diethylamine; or salts of primary amines or 
secondary amines with alkali metal are reacted with the halogen atom. 
The exemplified method for converting the halogen atom into a thioalkoxy 
group is a method that thioalcohols such as ethyl mercaptan; thiophenols 
such as thiophenol; salts of thioalcohols or thiophenols with alkali metal 
are reacted with the halogen atom. 
When the silyl group is introduced into a vinyl resin by the 
hydrosilylation reaction, not only a halogen atom but also an alkoxy 
group, an acyloxy group, or the like in the silyl group can be converted 
into other hydrolyzable functional group such as amino or aminooxy group 
in case of need. 
When the hydrolyzable functional group in the silyl group is directly 
converted into other hydrolyzable functional group by the hydrosilylation 
reaction, it is preferable that the above-mentioned conversion reaction is 
carried out at a temperature of 50.degree. to 150.degree. C. The 
conversion reaction can be carried out whether a solvent is present or 
not. When the reaction is carried out in a solvent, unreactive solvents 
such as ethers, hydrocarbons or acetic esters are preferably employed. 
The vinyl resins are not particulary limited unless the vinyl resins have a 
(meth)acrylic ester which has a higher alkyl group having not less than 10 
carbon atoms as the essential comonomer. As a compound for preparing the 
vinyl resin, there is exemplified, for instance, an acrylic acid ester 
such as methyl acrylate or butyl acrylate; a methacrylic acid ester such 
as methyl methacrylate or butyl methacrylate; a monomer having amide group 
such as acrylamide, methacrylamide, N-methylolacrylamide or 
N-methylolmethacrylamide; a monomer having epoxy group such as glycidyl 
acrylate or glycidyl methacrylate; a monomer having amino group such as 
diethylaminoethyl acrylate, diethylaminoethyl methacrylate or aminoethyl 
vinyl eter; acrylonitrile, iminol methacrylate, styrene, .alpha.-methyl 
styrene, alkyl vinyl ether, vinyl chloride, vinyl acetate, vinyl 
propionate, ethylene, and the like. The compounds may be employed alone or 
in admixture thereof. 
When the polymer or copolymer of the above-mentioned vinyl compounds (the 
vinyl resin) is prepared, a double bond between carbon atoms can be 
introduced into the vinyl resin by radical-copolymerizing a monomer such 
as allyl acrylate, allyl methacrylate or diallyl phthalate. The amount of 
the above-mentioned monomer is suitably determined in accordance with the 
number of silyl groups in the desired silyl group-containing vinyl resin 
In general, it is preferable that the molecular weight of the 
above-mentioned monomer is 300 to 4,000 per one silyl group. Also, in 
order to obtain a silyl group-containing vinyl resin having a molecular 
weight of 500 to 100,000, a chain transfer agent such as .alpha.-dodecyl 
mercaptan or t-dodecyl mercaptan may be added as occasion demands 
The vinyl resin can be prepared whether a solvent is present or not. In 
case of using a solvent, unreactive solvents such as ethers, hydrocarbons 
or acetic acid esters are preferably used. In the invention, the 
(meth)acrylic acid alkyl ester having not less than 10 carbon atoms is not 
particularly limited, and the (meth)acrylic acid alkyl ester is selected 
in accordance with the desired solubility or polymerizability of the estr 
of the desired appearance or properties of the film prepared from the 
silyl group-containing vinyl resin. Usually, a (meth)acrylic acid alkyl 
ester having 10 to 30 carbon atoms can be preferably used. 
Examples of the methacrylic acid ester are, for instance, lauryl 
methacrylate: CH.sub.2 .dbd.(CH.sub.3)COOC.sub.12 H.sub.25, tridecyl 
methacrylate: CH.sub.2 .dbd.C(CH.sub.3)COOC.sub.13 H.sub.27, methacrylate: 
CH.sub.2 .dbd.C(CH.sub.3)COOC.sub.16 H.sub.33, stearyl methacrylate: 
CH.sub.2 .dbd.C(CH.sub.3)COOC.sub.18 H.sub.37, CH.sub.2 
.dbd.C(CH.sub.3)COOC.sub.22 H.sub.45, and the like. Also, a mixture of the 
methacrylic acid esters having 2 kinds of alkyl groups can be employed. 
Examples of the mixture are, for instance, a mixture of an alkyl 
methacrylate which has an alkyl group having 12 carbon atoms and an alkyl 
methacrylate which has an alkyl group having 13 carbon atoms (Acry ester 
SL made by Mitsubishi Rayon Company Limited); alkyl methacrylates which 
can be easily obtained as a mixture which has alkyl groups having 9 to 11 
carbon atoms; and the like. 
Examples of acrylic acid ester are, for instance, tridecyl acrylate 
(CH.sub.2 .dbd.CHCOOC.sub.13 H.sub.27), stearyl acrylate: (CH.sub.2 
.dbd.CHCOOC.sub.18 H.sub.37), a mixture of an acrylic acid alkyl ester 
which has an alkyl group having 12 carbon atoms and an acrylic acid alkyl 
ester which has an alkyl group having 13 carbon atoms, and the like. 
The content of higher (meth)acrylalic acid alkyl ester in a silyl 
group-containing vinyl resin is within the range of 1 to 95% by weight, 
and the content can be adjusted in accordance with the desired use or 
properties of the silyl group-containing vinyl resin within the 
above-mentioned range. The preferable content is 5 to 50% by weight. 
Another method for preparing a silyl group-containing vinyl resin (B) is 
that a silane compound having the formula: 
##STR2## 
wherein R.sup.1 is a monovalent hydrocarbon group having 1 to 10 carbon 
atoms selected from the group consisting of an alkyl group, an aryl group 
and an aralkyl group; R.sup.2 is an organic residue having a polymerizable 
double bond; X is a halogen atom or a group selected from the group 
consisting of an lkoxy group having 1 to 10 carbon atoms, an acyloxy 
group, aminooxy group, phenoxy group, thioalkoxy group having 1 to 12 
carbon atoms and amino group and n is an integer of 1 to 3, a vinyl 
compound and the higher (meth)acrylic acid alkyl ester are subjected to 
radical copolymerization. 
Examples of the silane compound used in the present invention are, for 
instance, 
##STR3## 
and the like. 
The silane compounds can be prepared by various methods, for instance, a 
method that methyldimethoxysilane or methyldichlorosilane is reacted with 
acetylene, aryl acrylate, aryl methacrylate or diaryl phthalate in the 
presence of a catlyst of a transistion methal (VIII). 
It is preferable that the molecular weight of the silane compound is 
usually adjusted within the range of 300 to 4000 per one silyl group. 
As the vinyl compound used in the invention, there can be employed a vinyl 
compound having a hydroxyl group such as 2-hydroxyethyl acrylate, 
2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl 
methacrylate or 2-hydroxyvinyl ether other than the compounds used at time 
of the preparation of a vinyl resin in the above-mentioned method (A). 
The vinyl compound and the silane compound are copolymerized in a usual 
solution polymerization method. The vinyl compound, the silane compound, a 
radical initiator and, if necessary, a chain transfer agent such as 
n-dodecyl mercaptan or t-dodecyl mercaptan in order to obtain the silyl 
group-containing vinyl resin having a molecular weight of 500 to 100,000 
are reacted at a temperature of 50.degree. to 150.degree. C. 
The copolymerization reaction can be carried out in the presence or absence 
of a solvent Examples of the suitable solvent are, for instance, 
unreactive solvents such as ethers, hydrocarbons and acetic acid esters. 
The hydrolyzable group in the thus obtained silyl group-containing vinyl 
resin can be converted to other hydrolyzable group in the same manner as 
in the above-mentioned hydrosilylation reaction. 
The silyl group-containing vinyl resin of the invention can be formed a 
network structure to cure at ordinary temperature by exposing to the 
atmosphere. It is necessary that the kind of the hydrolyzable group in the 
silyl group-containing vinyl resin is carefully selected when using the 
silyl group-containing vinyl resin, since the curing rate varies in 
accordance with the atmosphere temperature, the relative humidity or the 
kind of the hydrolyzable group. 
The silyl group-containing vinyl resin is cured in the presence or absence 
of a curing catalyst in accordance with the curing conditions. 
However, it is practical to use a curing catalyst in order to satisfy the 
desired property such as a high curability or the desired workability such 
as a curability at ordinary temperature. 
The curable composition of the invention is not limited to the kind of 
curing catalysts Examples of the curing catalyst are, for instance, an 
organotin compound, an acid phospholic ester, a reactant of acid 
phospholic ester and amine, a saturated or unsaturated polyvalent 
carboxylic acid or an anhydride thereof, an organotitanium compound, and 
the like In general, it is preferable that the curing catalyst is used in 
the amount of not more than 20% by weight based on the silyl 
group-containing vinyl resin. 
The silyl group-containing vinyl resin of the invention is useful for 
paints or coating agents since the vinyl resin can be cured at ordinary 
temperature or low temperature. In fact, the vinyl resin can be rapidely 
cured at ordinary temperature to give a film having an excellent glossy 
surface as is shown in Examples. 
In case that a delustered film is needed, usual delustering agent can be 
added in the curable composition. 
The composition of the invention is not limited to the kind of the 
delustering agent. Examples of the delustering agent are, for instance, a 
silica delustering agent, a polyethylene wax delustering agent, a 
polycarbonate delustering agent, a polypropylene wax delustering agent, 
and the like. 
The amount of the delustering agent is 0.5 to 20 parts by weight based on 
100 parts by weight of the silyl group-containing vinyl resin. 
Also, the properties of the composition, e.g. the surface hardness, can be 
improved by adding a compound (e.g. ethylsilicate) which is condensation 
polymerizable with the silyl group-containing vinyl resin of the invention 
to the vinyl resin. 
Moreover, silyl group-containing vinyl resin can be blended with various 
resins used for paints or coating agents, and it can improve the 
properties such as adhesion or weatherability of the paints or coating 
agents. 
Various kinds of fillers or pigments can be blended with the silyl 
group-containing vinyl resin of the present invention. Examples of the 
fillers or pigments are, for instance, silicas, calcium carbonate, 
magngsium carbonate, titanium dioxide, iron oxide, glass fibers, and the 
like. The thus obtained composition of the invention is useful for not 
only the above-mentioned paints or coating agents but also coating 
compositions used for airplanes, buildings, automobiles or glasses; 
compositions for sealing; a surface treating agent used in inorganic or 
organic substances. 
The present invention is more specifically described and explained by means 
of the following Examples in which all percents and parts are by weight 
unless otherwise noted. It is to be understood that the present invention 
is not limited to the Examples, and various changes and modifications may 
be made in the invention without departing from the spirit and scope 
thereof