Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From silicon reactant having at least one...
Reexamination Certificate
2000-04-13
2001-10-02
Moore, Margaret G. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From silicon reactant having at least one...
C528S038000
Reexamination Certificate
active
06297341
ABSTRACT:
BACKGROUND OF INVENTION
The present invention relates to a silicone-containing polyimide resin, a silicone-containing polyamic acid, and methods for manufacturing these. More particularly, it relates to a silicone-containing polyimide resin with superior heat resistance and flexibility, to a silicone-containing polyamic acid for which this polyimide resin is a raw material, and methods for manufacturing these.
Because of their excellent mechanical properties, heat resistance, and so on, polyimide resins are widely used as molding materials, films, and coating agents. In general, however, a polyimide resin has poor molding workability, flexibility, and solubility in solvents, so there has been proposed a method in which a polyorganosiloxane having amino groups at both ends of the molecular chain is copolymerized as a soft segment (see Japanese Laid-Open Patent Application 4-36321). Nevertheless, a problem with a silicone-containing polyimide resin obtained in this manner is that because the polyorganosiloxane chain is so long, low-molecular weight cyclic siloxane is generated by a cleavage reaction of the polyorganosiloxane chain under high temperature environments, the result of which is a decrease in heat resistance. Accordingly, there has been proposed a silicone-containing polyimide resin in which a disiloxane chain with two silicon atoms is copolymerized (see Japanese Laid-Open Patent Applications 58-27722 and 61-118424), but a drawback was that the two silicon atoms did not sufficiently improve flexibility. In light of this, there is a need for a polyimide resin with superior heat resistance and flexibility.
As a result of diligent study, the inventors arrived at the present invention upon discovering that the above problems can be solved by copolymerizing an organosiloxane having a specific chemical structure. Specifically, it is an object of the present invention to provide a silicone-containing polyimide resin with superior heat resistance and flexibility, a silicone-containing polyamic acid that serves as the raw material for this polyimide resin, and methods for manufacturing these.
SUMMARY OF INVENTION
The present invention is:
(1) a silicone-containing polyimide resin comprising 0.1 to 100 mol % structural units described by formula 1
and 0 to 99.9 mol % structural units described by formula 2:
where Ar
1
and Ar
2
are tetravalent organic groups having at least one aromatic ring; Ar
3
is a divalent organic group having at least one aromatic ring; each R is an independently selected monovalent hydrocarbon group free of aliphatic unsaturated bonds; X is an alkylene group or alkyleneoxyalkylene group having at least two carbon atoms; m and n are integers from 0 to 3, and (m+n) is an integer from 1 to 6;
(2) a silicone-containing polyamic acid comprising 0.1 to 100 mol % structural units described by formula
and 0 to 99.9 mol % structural units described by formula
where Ar
1
and Ar
2
are tetravalent organic groups having at least one aromatic ring; Ar
3
is a divalent organic group having at least one aromatic ring; each R is an independently selected monovalent hydrocarbon group free of aliphatic unsaturated bonds; X is an alkylene group or alkyleneoxyalkylene group having at least two carbon atoms; Z is a hydrogen atom or a silyl group described by formula —SiR
3
where R is as defined above; m and n are integers from 0 to 3, and (m+n) is an integer from 1 to 6; and
(3) to methods for manufacturing these.
DESCRIPTION OF INVENTION
The present invention is a polyimide, a silicone-containing polyamic acid, and a method for preparation of both.
The silicone-containing polyimide resin comprises 0.1 to 100 mol % structural units described by formula 1
and 0 to 99.9 mol % structural units described by formula 2:
where Ar
1
and Ar
2
are tetravalent organic groups having at least one aromatic ring; Ar
3
is a divalent organic group having at least one aromatic ring; each R is an independently selected monovalent hydrocarbon group free of aliphatic unsaturated bonds; X is an alkylene group or alkyleneoxyalkylene group having at least two carbon atoms; m and n are integers from 0 to 3, and (m+n) is an integer from 1 to 6;
The silicone-containing polyamic acid comprises 0.1 to 100 mol % structural units described by formula
and 0 to 99.9 mol % structural units described by formula
where Ar
1
and Ar
2
are tetravalent organic groups having at least one aromatic ring; Ar
3
is a divalent organic group having at least one aromatic ring; each R is an independently selected monovalent hydrocarbon group free of aliphatic unsaturated bonds, and the; X is an alkylene group or alkyleneoxyalkylene group having at least two carbon atoms; Z is a hydrogen atom or a silyl group described by formula —SiR
3
where R is as defined above; m and n are integers from 0 to 3, and (m+n) is an integer from 1 to 6.
First, the silicone-containing polyimide resin of the present invention will be described. The silicone-containing polyimide resin of the present invention consists of structural units described by the following formula 1 alone, or consists of structural units described by the following formulas 1 and 2.
In the above formulas, Ar
1
and Ar
2
are tetravalent organic groups having at least one aromatic ring, examples of which include groups described by the following formulas.
Of these, groups described by the following formulas are preferred.
Ar
3
is a divalent organic group having at least one aromatic ring, examples of which include groups described by the following formulas.
Of these, groups described by the following formulas are preferred.
Each R is an independently selected monovalent hydrocarbon group free of aliphatic unsaturation. Specific examples of R include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; aryl groups such as phenyl, tolyl, and xylyl; and aralkyl groups such as benzyl and phenethyl. X is an alkylene group or alkyleneoxyalkylene group having at least two carbon atoms, specific examples of which include ethylene, propylene, butylene, pentylene, hexylene, and ethyleneoxypropylene. The letters m and n represent integers from 0 to 3, and (m+n) must be an integer from 1 to 6. It is preferred for (m+n) to be 2, in which case it is preferable for both m and n to be 1.
In the silicone-containing polyimide resin of the present invention, the copolymerization ratio of the above-mentioned structural units is such that (structural units described by formula 1): (structural units described by formula 2) is between 0.1:99.9 and 100:0 mol %, and preferably between 1:99 and 100:0 mol %. This silicone-containing polyimide resin is in the form of a solid at 25° C., but may be dissolved in a solvent and made into a liquid at the time of its use. The intrinsic viscosity thereof (the value for an N-methylpyrrolidone solution measured at 25° C.) is usually between 0.1 and 3.0 dL/g, and preferably between 0.2 and 2.0 dL/g.
The present silicone-containing polyimide resin can be manufactured by heating a silicone-containing polyamic acid composed of 0.1 to 100 mol % structural units described by the following formula A and 0 to 99.9 mol % structural units described by formula B to effect dehydration cyclization to produce an imide:
In the above formulas, Ar
1
, Ar
2
, Ar
3
, R, X, m, and n are defined the same as above. Z is a hydrogen atom or a silyl group described by formula —SiR
3
where R is as defined above. Examples of methods for cyclization by heating and dehydration include a method in which a substrate is directly coated with a solution of the polyamic acid, and this coating is heat treated to produce a film, and a method in which a non-polar organic solvent that is not miscible with water is added to the polyamic acid and azeotropic dehydration is performed, after which the water thus produced is removed, and the remainder is then applied to a substrate and heat treated. The heat treatment conditions here preferably comprise a temperature range of 50 to 400° C. The intrinsic viscosity of this silicone-con
Furukawa Haruhiko
Morita Yoshitsugu
Ueki Hiroshi
Boley William F.
Dow Corning Toray Silicone Company LTD
Moore Margaret G.
Troy Timothy J.
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