Stock material or miscellaneous articles – Composite – Of fluorinated addition polymer from unsaturated monomers
Reexamination Certificate
1998-01-29
2001-03-20
Lam, Cathy (Department: 1774)
Stock material or miscellaneous articles
Composite
Of fluorinated addition polymer from unsaturated monomers
C428S422000, C524S265000, C524S462000, C524S463000, C525S326200, C525S326300, C526S246000, C526S247000, C526S248000, C526S255000
Reexamination Certificate
active
06203912
ABSTRACT:
The present invention relates to an electronic article having a thin film of a triazine ring-containing fluoropolymer, a prepreg prepared by impregnating a reinforcing material with a cyano group-containing fluoropolymer, a method for preparing a cyano group-containing fluoropolymer and a paint composition for an electronic article which contains a cyano group-containing copolymer.
Recently, in proportion to developments of miniaturization, high integration-modification and high density-modification of a semiconductor element or a multi-layered circuit board, it is demanded to provide an insulating material having a low dielectric constant which enables to reduce a delay time of signal propagation. Examples of a material widely used at present as a buffer coating film of a semiconductor element, a passivation film of a semiconductor element, an insulating film between layers of a semiconductor element, an &agr; ray-shielding film of a semiconductor element or an insulating film between layers of a multi-layered circuit board, includes a silicon oxide film, a silicon nitride film, a polyimide resin and the like, but they have a high relative dielectric constant respectively of 4-5, 7-9, 3.5-4 or the like, and it is demanded to provide a material having a low relative dielectric constant of at most 3.
A fluororesin has various desirable properties of not only a low dielectric constant but also a high heat resistance, a high chemical resistance and the like, and accordingly, its development is widely conducted.
However, a semiconductor element or a multi-layered circuit board is a composite of a circuit metal, other inorganic insulating films and the like, but since they are exposed to a high temperature of from 200 to 450° C., a fluororesin is hardly usable for this purpose because it has a low glass transition temperature and has an undesirable fluidity, a small elastic modulus and a high linear expansion coefficient in a higher temperature zone and therefore has a low reliability to be used for a semiconductor element or a circuit board.
JP-A-6-340710 discloses a triazine ring-containing fluoropolymer, but does not disclose an electronic article having a thin film of this polymer. Further, this reference does not disclose that a cyano group-containing fluoropolymer of averagely tetramer or higher provides a excellent mechanical property and pyrolysis resistance at a high temperature.
On the other hand, in a print circuit board, a delay time of signal propagation is proportional to a square root of a dielectric constant of an insulating substrate for circuit, so it is certainly demanded to provide a print circuit board using an insulating substrate having a low dielectric constant due to the requirement of a high-speed signal propagation. Examples of an insulating substrate used heretofor include a substrate obtained by impregnating a glass cloth or paper with an epoxy resin and curing the impregnated material, a substrate obtained by impregnating paper with a phenolic resin and curing the impregnated material, a substrate obtained by impregnating a glass fiber with a polyimide and curing the impregnated material, and the like, but since the resins thus used have a high dielectric constant, and a relative dielectric constant of the insulating substrates thus obtained is higher than 3.
A substrate composed of a glass cloth and polytetrafluoroethylene (PTFE) is known to have a low dielectric constant, but this substrate is required to be cured at a high temperature of at least 300° C. and has a problem in respect to an adhesive property to a metal foil and has a difficulty in processability. PTFE has a very high melting viscosity of from 10
12
to 10
13
poises, and is therefore poor in workability. JP-A-62-283694 and JP-A-8-157621 disclose an example of using a polytetrafluoroethylene porous material as a reinforcing material, but there is disclosed no example of using a combination of a fluororesin and a fluororesin porous material.
Accordingly, an object of the present invention is to provide an electronic article having a thin film of a triazine ring-containing fluoropolymer excellent in mechanical properties and pyrolysis resistance, while maintaining excellent properties of a low dielectric constant and a high chemical resistance of a fluororesin. Another object of the present invention is to provide an easily moldable prepreg obtained by impregnating a reinforcing material with a cyano group-containing fluoropolymer, a method for preparing a cyano group-containing fluoropolymer and a paint composition for an electronic article containing a cyano group-containing fluoropolymer.
Thus, the present invention provides an electronic article having a thin film of a triazine ring-containing fluoropolymer obtained by trimerization of a cyano group of a cyano group-containing fluoropolymer having a polymerization unit of the formula (1):
—[CF
2
—CF(A
1
)]— (1)
wherein A
1
is —OR
1
CN, —CN or —R
1
CN, and R
1
is a C
1
-C
15
polyfluoroalkylene group which may have an ether bond.
Further, the present invention provides a prepreg obtained by impregnating a reinforcing material with a cyano group-containing fluoropolymer having a polymerization unit of the above formula (1).
Still further, the present invention provides a method for preparing a cyano group-containing fluoropolymer (iii) having a polymerization unit of the formula (1), which comprises reacting a fluoropolymer (i) having a polymerization unit of the formula (3) with ammonia to obtain a fluoropolymer (ii) having a polymerization unit of the formula (4) and subjecting the fluoropolymer (ii) to a nitrile-formation reaction to obtain a cyano group-containing fluoropolymer (iii) having a polymerization unit of the formula (1), characterized in that the nitrile-formation reaction is carried out in a solvent to dissolve the fluoropolymer (ii):
—[CF
2
—CF(A
1
)]— (1)
—[CF
2
—CF(A
2
)]— (3)
—[CF
2
—CF(A
3
)]— (4)
wherein in the above formulas (1), (3) and (4), A
1
is —OR
1
CN, —CN or —R
1
CN, A
2
is —OR
1
COOR
2
, —COOR
2
or —R
1
COOR
2
, A
3
is —OR
1
CONH
2
, —CONH
2
or —R
1
CONH
2
, R
1
is a C
1
-C
15
polyfluoroalkylene group which may have an ether bond, and R
2
is a C
1
-C
10
alkyl group which may have a fluorine atom or a chlorine atom.
Also, the present invention provides a paint composition for an electronic article, which contains a cyano group-containing fluoropolymer having a polymerization unit of the above formula (1).
In the polymerization unit of the above formula (1), A
1
is —OR
1
CN, —CN or —R
1
CN, and R
1
is a C
1
-C
15
polyfluoroalkylene group which may contain an ether bond. The proportion of the ether bond in the polyfluoroalkylene group is preferably one per 1-4 carbon atoms of the polyfluoroalkylene group. The wording “which may contain an ether bond” means that an ether bond composed of oxygen between carbon and carbon in R
1
may be contained.
The polyfluoroalkylene group means an alkylene group having at least 2 hydrogen atoms substituted with fluorine atoms, and includes a perfluoroalkylene group having all of hydrogen atoms of the alkylene group substituted with fluorine atoms and also includes an alkylene group having at least 2 hydrogen atoms substituted with fluorine atoms and having at least one hydrogen atom substituted with a halogen atom other than a fluorine atom. The halogen atom other than a fluorine atom is preferably a chlorine atom.
The polyfluoroalkylene group is preferably an alkylene group having at least 50%, more preferably at least 70% of the total hydrogen atoms substituted with fluorine atoms. Still further preferable polyfluoroalkylene group is a perfluoroalkylene group.
A cyano group-containing fluoropolymer having a polymerization unit of the formula (1) is obtained by polymerizing a vinyl compound of the following formula (2) in the presence of a radical-generating source or polymerizing a vinyl compound of the following formula (5) in the presence of a radical-generating source to
Miyake Haruhisa
Tamura Masayuki
Tayanagi Jun-ichi
Watakabe Atsushi
Asahi Glass Company. Ltd.
Lam Cathy
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
LandOfFree
Electronic article having fluoropolymer thin film does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electronic article having fluoropolymer thin film, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic article having fluoropolymer thin film will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2452150