Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
1998-10-01
2001-02-27
Zitomer, Fred (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S227000, C525S230000, C525S328800, C525S329700, C525S329900, C525S330300, C525S330500, C525S330700, C525S342000, C525S374000, C525S379000, C525S222000
Reexamination Certificate
active
06194516
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method for producing a hydroxyl-terminated (meth)acrylic polymer, a curable composition containing said polymer, a method for producing an alkenyl- or crosslinkable silyl-terminated polymer, which is derived from said polymer, and a curable composition comprising said alkenyl- or crosslinking silyl-terminated polymer as a main component.
BACKGROUND OF THE INVENTION
It is known that hydroxyl-terminated polymers, when crosslinked by using a compound having a functional group reactive with a hydroxyl group, for example an isocyanate compound, as a curing agent, give cured products excellent in heat resistance and durability, among others.
The principal chain skeleton of such hydroxyl-terminated polymers includes, among others, polyether polymers such as polyethylene oxide, polypropylene oxide and polytetramethylene oxide; hydrocarbon polymers such as polybutadiene, polyisoprene, polychloroprene, polyisobutylene and hydrogenation products thereof; and polyester polymers such as polyethylene terephthalate, polybutylene terephthalate and polycaprolactone. According to their principal chain skeleton and crosslinking manner, they are used for various applications.
Unlike the above-mentioned polymers, which are obtainable by ionic polymerization or condensation polymerization, hydroxyl-terminated vinyl polymers obtained by radial polymerization have scarcely been put into practical use.Among vinyl polymers, (meth)acrylic polymers have those characteristics which can hardly be attained by the above-mentioned polyether polymers, hydrocarbon polymers or polyester polymers, for example high weather resistance and transparency. Ones having hydroxyl groups at the side chains are used in weather-resistant paints, for instance.
(Meth)acrylic polymers having hydroxyl groups at the chain ends, if obtained in a simple and easy manner, will be able to give cured products improved in physical properties such as elasticity compared with ones having hydroxyl groups at the side chains. Therefore, a number of investigators have so far tried to establish production processes therefor. However, it is not easy to produce them on a commercial scale.
Japanese Kokai Publication Hei-05-262808 discloses a method for synthesizing (meth)acrylic polymers having a hydroxyl group at each terminus by using a hydroxyl-containing disulfide as a chain transfer agent. For securing hydroxyl groups introduction into both ends, however, this method requires use of the chain transfer agent in a large amount relative to an initiator. This poses a problem from the viewpoint of production step. In addition, Japanese Kokoku Publication Hei-01-19402 discloses a method for producing hydroxyl-terminated (meth)acrylic polymers by using hydrogen peroxide as an initiator. It is difficult, however, to secure hydroxyl groups introduction into both ends. Thus, a method actually employed consists in copolymerization with a hydroxyl-containing vinyl monomer (e.g. 2-hydroxyethyl methacrylate). Moreover, Japanese Kokai Publication Hei-04-132706 discloses a method for producing a hydroxyl-terminated vinyl polymer which comprises preparing a halogen-terminated (meth)acrylic polymer by polymerizing a (meth)acrylic monomer using a telogen such as carbon tetrachloride and then substituting the terminal halogen by reacting with a nucleophile such as a diol compound, hydroxyl-containing carboxylic acid or hydroxyl-containing amine. By this method, too, it is difficult to introduce a functional group into both termini at high ratios, since the chain transfer of the telogen is not sufficient.
Accordingly, it is an object of the present invention to provide a method for producing a (meth)acrylic polymer which contains terminal hydroxyl groups in a higher proportion as compared with the prior art methods, as well as a curable composition containing the same as a main component thereof. Another object of the invention is to provide a method for further introducing another functional group (e.g. alkenyl, crosslinkable silyl) by making use of the reactivity of the terminal hydroxyl groups, as well as a curable composition containing the same.
SUMMARY OF THE INVENTION
As one of the objects mentioned above, the hydroxyl-terminated (meth)acrylic polymer can be produced by converting a halogen atom in a terminal structure of the general formula (1)
—CH
2
—C(R
1
)(CO
2
R
2
)(X) (1)
(wherein R
1
is hydrogen or methyl, R
2
is alkyl containing 1 to 20 carbon atoms, aryl containing 6 to 20 carbon atoms or aralkyl containing 7 to 20 carbon atoms, and X is chlorine, bromine or iodine), of a (meth)acrylic polymer obtained by polymerizing a (meth)acrylic monomer using an organic halide or a halogenated sulfonyl compound as an initiator and, as a catalyst, a metal complex with a central metal selected from the elements belonging to the groups 8, 9, 10 and 11 in the periodic table, into a hydroxyl-containing substituent.
As specific examples of such production method, there may be mentioned a method comprising producing the (meth)acrylic polymer having a terminal structure of the general formula (1) by polymerizing a (meth)acrylic monomer using an organic halide or a halogenated sulfonyl compound as an initiator and, as a catalyst, a metal complex with a central metal selected from the elements belonging to the groups 8, 9, 10 or 11 in the periodic table, and further reacting said polymer with a compound having a polymerizable alkenyl group and a hydroxyl group; a method comprising reacting the (meth)acrylic polymer having a terminal structure of the general formula (1) with an elemental metal or an organometallic compound to prepare an enolate anion, and then treating with an aldehyde or a ketone; or a method comprising reacting said starting polymer with a hydroxyl-containing oxy anion or a hydroxyl-containing carboxylate anion.
The said polymer can also be produced by preparing a (meth)acrylic polymer having a hydroxyl group at one end and a structure of general formula (1) at the other end by polymerizing a (meth)acrylic monomer using a hydroxyl-containing halide as an initiator and, as a catalyst, a metal complex with a central metal selected from the elements belonging to the groups 8, 9, 10 or 11 in the periodic table, and further converting the halogen to a hydroxyl-containing substituent.
The said polymer can further be produced by preparing a (meth)acrylic polymer having a hydroxyl group at one end and a structure of the general formula (1) at the other end by the said polymerization using a hydroxyl-containing halide as an initiator, and further subjecting the same to coupling reaction between the terminal halogens in the general formula (1) through a compound having at least two identical or different functional groups each capable of substituting the terminal halogen.
A curable composition of the present invention comprises two components: (A) a hydroxyl-terminated (meth)acrylic polymer; and (B) a compound having at least two functional groups each capable of reacting with a hydroxyl group.
According to the present invention, an alkenyl-terminated (meth)acrylic polymer can be produced by converting the terminal hydroxyl group of the hydroxyl-terminated (meth) acrylic polymer obtained by the above methods into an alkenyl-containing substituent. A curable composition based on the alkenyl-terminated (meth)acrylic polymer obtained by this method comprises two components: (C) the alkenyl-terminated (meth)acrylic polymer; and (D) a hydrosilyl-containing compound.
Furthermore, according to the invention, a crosslinkable silyl-terminated (meth)acrylic polymer can be produced by subjecting the alkenyl-terminated (meth)acrylic polymer to addition reaction with a crosslinkable silyl-containing hydrosilane compound, or by reacting the hydroxyl-terminated (meth)acrylic polymer obtained by the above methods with a compound containing a crosslinkable silyl group and a functional group reactive with a hydroxyl group. Another curable composition can further be obtained based on the thus-obtained, cross
Kitano Kenichi
Kusakabe Masato
Nakagawa Yoshiki
Kaneka Corporation
Pollock Vande Sande & Amernick
Zitomer Fred
LandOfFree
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