Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From silicon reactant having at least one...
Reexamination Certificate
2001-09-19
2003-06-03
Dawson, Robert (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From silicon reactant having at least one...
C528S030000, C528S038000, C528S041000
Reexamination Certificate
active
06573356
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a room temperature-curing organopolysiloxane composition having superior adhesion to resins, used for building construction or used in the bonding or fixing of electric or electronic component parts.
2. Description of the Prior Art
RTV (room temperature vulcanizable) silicone rubbers cross-linkable by moisture are easy to handle and also have superior weatherability and electrical properties. Accordingly, they are utilized in various fields such as sealing materials for building construction and adhesives used in electric and electronic fields. Especially in the sealing materials for building construction, deoxime-type RTV silicone rubbers having superior weatherability are in wide use. In respect of adherends such as resin materials, however, there is a tendency toward the use of dealcohol-type ones on account of suitability for resins. The same also applies to the bonding or fixing of electric or electronic component parts.
However, with development of various adhesive compositions and improvement in techniques for ensuring durability of resins, cases have increased in which conventional sealing materials can not bond some adherends.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a room temperature-curing organopolysiloxane composition having superior adhesion to resins of various types.
Taking account of the above background, the present inventors have tried making development of sealing materials which are adhesive to resins. As a result, they have discovered that the use of a partial hydrolysis-condensation product of a specific silane compound brings about a dramatic improvement in adhesion to resins having ever been considered to be slightly bondable. Thus, they have accomplished the present invention.
More specifically, the present invention provides a room temperature-curing organopolysiloxane composition comprising:
(A) 100 parts by weight of at least one member selected from the group consisting of an organopolysiloxane represented by the general formula (1):
HO(SiR
1
2
O)
n
H (1)
wherein R
1
's are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 10 or more; and an organopolysiloxane represented by the general formula (2):
wherein R
1
's and n are as defined above, and m's are each independently an integer of 0 or 1;
(B) from 0.1 part by weight to 30 parts by weight of a silane compound having in one molecule an average of at least two silicon atom-bonded hydrolyzable groups and in which the silicon atom-bonded remaining group or groups is/are a group or groups selected from the group consisting of a methyl group, an ethyl group, a propyl group, a vinyl group and a phenyl group; a partial hydrolysis-condensation product thereof; or a mixture of these; and
(C) from 0.1 part by weight to 10 parts by weight of a mixture of siloxanes having degrees of polymerization of from 2 to 10, which is a partial hydrolysis-condensation product of a silane compound having a group selected from the group consisting of an amino group, an epoxy group, a mercapto group, an acryloyl group and a methacryloyl group each bonded to the silicon atom through a carbon atom and having a hydrolyzable group bonded to the silicon atom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described below in detail.
The organopolysiloxane composition of the present invention is constituted basically of the following components (A) to (C).
Component (A)
The component-(A) is at least one organopolysiloxane selected from the group consisting of an organopolysiloxane represented by the general formula (1):
HO(SiR
1
2
O)
n
H (1)
and an organopolysiloxane represented by the general formula (2):
In the general formula (1) or (2) representing the component-(A) organopolysiloxane, R
1
's are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, as exemplified by alkyl groups such as a methyl group, an ethyl group and a propyl group; cycloalkyl groups such as a cyclohexyl group; alkenyl groups such as a vinyl group and an allyl group; aryl groups such as a phenyl group and a tolyl group; and corresponding substituted groups in which the hydrogen atoms have partially been substituted with a halogen atom or the like, e.g., 3,3,3-trifluoropropyl group. In the general formula (1) or (2), R
1
's may be identical with or different from each other. Letter symbol n in the general formula (1) and (2) is an integer of 10 or more, and may particularly be an integer that makes this diorganopolysiloxane have a viscosity at 25° C. within the range of from 25 to 500,000 cSt, and preferably within the range of from 500 to 100,000 cSt. Letter symbol m in the general formula (2) is an integer of 0 or 1.
Component (B)
The component-(B) is a silane compound having in one molecule an average of at least two silicon atom-bonded hydrolyzable groups and in which the silicon atom-bonded remaining group or groups, if any, is/are a group or groups selected from the group consisting of a methyl group, an ethyl group, a propyl group, a vinyl group and a phenyl group; a partial hydrolysis-condensation product thereof; or a mixture of these.
The hydrolyzable group the component-(B) silane compound and its partial hydrolysis-condensation product has may include, e.g., a ketoxime group, an alkoxyl group, an acetoxyl group and an isopropenoxyl group.
As specific examples of the component (B), it may include ketoxime silanes such as tetrakis(methylethylketoxime)silane, methyltris(dimethylketoxime)silane, methyltris(methylethylketoxime)silane, ethyltris(methylethylketoxime)silane, methyltris(methylisobutylketoxime)silane and vinyltris(methylethylketoxime)silane; alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane and vinyltrimethoxysilane; acetoxysilanes such as methyltriacetoxysilane and vinyltriacetoxysilane; and isopropenoxysilanes such as methyltriisopropenoxysilane; as well as partial hydrolysis-condensation products of any of these silanes.
The component (B) is used in an amount ranging from 0.1 to 30 parts by weight, and preferably ranging from 1 to 15 parts by weight, based on 100 parts by weight of the component (A). If it is less than 0.1 part by weight, no sufficient cross-linking may take place to make it difficult to obtain cured products having the intended rubber elasticity. If it is more than 30 parts by weight, the cured products obtained tend to have low mechanical properties.
Component-(C)
The component-(C) siloxane is a component having an important action to improve the adhesion of the composition of the present invention to resins.
The component-(C) siloxane is a partial hydrolysis-condensation product of a specific silane compound, and is a mixture of siloxanes having a hydrolyzable group bonded to a silicon atom and having degrees of polymerization of from 2 to 10.
The silane compound, a precursor substance of the component-(C) siloxane, has a functional group selected from the group consisting of an amino group, an epoxy group, a mercapto group, an acryloyl group and a methacryloyl group, and also any of these functional groups is bonded to the silicon atom through a carbon atom. Where two or more functional groups are present in the silane compound, they may be bonded to the silicon atom through different carbon atoms, or may be bonded to the silicon atom through the same carbon atom.
This silane compound may have 1 to 3, and preferably 2 or 3, hydrolyzable groups. The hydrolyzable group is exemplified by the same examples as those for the hydrolyzable group of the component (B). In particular, an alkoxyl group is preferred.
Of the silane compound, an amino-group-containing silane is preferred. In particular, silanes represented by the general formulas (3) and (4) are preferred.
H
2
N(CH
2
)
n
Si(R
3
)
c
(OR
2
)
3-c
(3)
H
2
N(CH
2
)
n
HN(CH
2
)
n
Si(R
3
)
c
(OR
2
)
3-c
&em
Araki Tadashi
Kameda Norio
Kimura Tsuneo
Dawson Robert
Shin-Etsu Chemical Co. , Ltd.
Zimmer Marc S.
LandOfFree
Room temperature-curing organopolysiloxane composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Room temperature-curing organopolysiloxane composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Room temperature-curing organopolysiloxane composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3138912