Stock material or miscellaneous articles – Composite – Of silicon containing
Reexamination Certificate
2001-06-28
2004-03-09
Moore, Margaret G. (Department: 1712)
Stock material or miscellaneous articles
Composite
Of silicon containing
C528S026000, C528S028000, C528S038000
Reexamination Certificate
active
06703133
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a polyimide silicone resin effectively utilizable for uses in, e.g., prevention of corrosion of liquid-crystal display panel electrodes and surface protection of wiring component parts of semiconductor devices and printed circuit boards, and also relates to its solution composition and a polyimide silicone resin film.
2. Description of the Prior Art
Room temperature-vulcanizable (RTV) silicones are widely used in protective materials for electrodes of liquid-crystal display panels, the electrodes being formed of, e.g., ITO (indium tin oxide). However, as display devices have been improved in performances in recent years, specifically, their panels, weights and thickness have been made larger, lighter and thinner, respectively. Also, as liquid-crystal display panels have become used in a wide range of purposes, severer properties have become required for electrode protective materials. Accordingly, it has been sought to bring out more highly reliable electrode protective materials.
Meanwhile, polyimide silicone resins have energetically been researched and developed in recent years. They, however, are usually only known as those of a type which can be diluted in a high-boiling solvent or as those of a type which can be used as solutions in the state of polyamic acid (i.e., the precursor of polyimide), i.e., solutions of polyamic acid silicone resins. In the case of the polyimide silicone resins of the type which is diluted in a high-boiling solvent, the solvent must be removed at a high-temperature to effect curing in order to obtain the desired films. Hence, such resins are not adaptable as electrode protective materials for liquid-crystal display panels not resistant to high temperatures. Similarly, the polyamic acid silicone resin solutions must be treated at a high temperature of 200° C. or above in order to effect imidization; thus, in this case, too, the resins are not suitable as electrode protective materials for liquid-crystal display panels.
The electrode protective materials are also required not to impart any stress to the display panels. However, conventional polyimide silicone resins can not endow films with elasticity, compared to room temperature-vulcanizable (RTV) silicones, and may cause warpage in the display panels because of shrinkage on curing.
SUMMARY OF THE INVENTION
Under such circumstances, objects of the present invention are to provide a polyimide silicone resin which can form films at relatively low temperature, has superior adhesiveness to substrates and durability under conditions of high humidity and also has low stress and high elongation, to provide a polyimide silicone resin solution composition used to form films, and to provide a polyimide silicone resin film which may cause neither warpage nor copper sheet corrosion when used in electrode protective films for electronic component parts or semiconductor devices.
As a result of extensive studies, the present inventors have discovered that a polyimide silicone resin derived from a diamine comprising a diaminopolysiloxane and an acid dianhydride, which comprises at least 50% by weight of a siloxane residual group, and has an elongation at rupture of 400% or higher and a modulus of elasticity of 500 N/mm
2
or lower, its solution composition and a film comprised of the composition and formed on a substrate, can achieve the above objects. Thus, they have accomplished the present invention.
That is, the present invention in the first aspect provides a polyimide silicone resin derived from a diamine comprising a diaminopolysiloxane and an acid dianhydride, which comprises at least 50% by weight of a siloxane residual group, and has an elongation at rupture of 400% or higher and a modulus of elasticity of 500 N/mm
2
or lower.
The present invention in the second aspect provides a polyimide silicone resin solution composition comprising the above polyimide silicone resin and a ketone solvent having a boiling point of 130° C. or below.
The present invention in the third aspect provides a polyimide silicone resin film comprising the above polyimide silicone resin and formed on a substrate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described below in detail.
The polyimide silicone resin is obtained from a diamine comprising a diaminopolysiloxane and an acid dianhydride.
The acid dianhydride which may be used for the polyimide silicone resin of the present invention includes, e.g., 4,4′-hexafluoropropylidenebisphthalic dianhydride (6FDA), 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-benzophenonetetracarboxylic dianhydride, and ethylene glycol bistrimellitic dianhydride. In particular, 6FDA and 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride are preferred. Any of these may be used alone or in combination of two or more types.
The diamine which can used for the polyimide silicone resin of the present invention preferably includes, in addition to the diaminopolysiloxane, e.g., diamines represented by the general formula (2):
wherein X represents —C(CH
3
)
2
—, —C(CF
3
)
2
— or —SO
2
—. The diamines represented by the general formula (2) includes 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and bis-4-(4-aminophenoxy)phenylsulfone. Any of these may be used alone or in combination of two or more. In particular, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is preferred.
As the diaminopolysiloxane used in the polyimide silicone resin of the present invention, compounds represented by the following general formula (1) are preferred, any of which may be used alone or in combination of two or more types.
wherein n represents the number of repetition of dimethylsiloxane unit, and is an integer of 0 or more, preferably 0 to 120, and more preferably 0 to 90.
The siloxane residual group in the present invention is meant to be a group represented by —(R)
2
SiO— where R represents an alkyl group such as methyl, ethyl, propyl, phenyl groups, and the content of the siloxane residual group can be determined according to the following expression for calculation.
Siloxane residual group content (% by weight)=(weight of siloxane residual group calculated from the weight of the diaminopolysiloxane used)/(weight of polyimide silicone resin to be produced theoretically from the weights of the raw materials used)×100
In the polyimide silicone resin of the present invention, the siloxane residual group is in a content of 50% by weight or more, and preferably from 55 to 75% by weight. If it is in a content less than 50% by weight, the resin may cause a great shrinkage on curing.
The polyimide silicone resin of the present invention has an elongation at rupture of 400% or higher. It also has a modulus of elasticity of 500 N/mm
2
or lower, and preferably 100 N/mm
2
or lower. If it has an elongation at rupture lower than 400% or a modulus of elasticity higher than 500 N/mm
2
, the resin may cause distortion such as warpage in the panel after it has been formed into the polyimide silicone resin film.
In the present invention, the polyimide silicone resin may preferably less contain a cyclic siloxane oligomer having 20 or less silicon atoms. The cyclic siloxane oligomer having 20 or less silicon atoms is represented by the formula:
[(CH
3
)
2
SiO]
n
wherein n is an integer of 3 to 20. For example, when n is 3, it is hexamethylcyclotrisiloxane and, when n is 4, octamethylcyclotetrasiloxane. These cyclic siloxane oligomers are volatile, and are known to cause what is called silicone trouble, such as trouble in electrical contacts. Accordingly, where the resin is used for electric and electronic purpose, these cyclic siloxane oligomers may preferably be in a content as small as possible. In order for the resin not to cause this silicone trouble such as trouble in electrical contacts, such volatile silicones in the polyim
Kato Hideto
Sugo Michihiro
Moore Margaret G.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Shin-Etsu Chemical Co. , Ltd.
LandOfFree
Polyimide silicone resin, its solution composition, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polyimide silicone resin, its solution composition, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyimide silicone resin, its solution composition, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3265328