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
1999-07-16
2002-11-05
Sellers, Robert E. L. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S526000, C525S528000, C525S476000, C528S121000, C528S122000, C528S123000, C528S124000
Reexamination Certificate
active
06476160
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention generally relates to a one-pack epoxy resin composition. Specifically, the present invention is directed to a one-pack epoxy resin composition having good storage stability and excellent curing property. More specifically, the present invention is directed to a one-pack epoxy resin composition that is useful as adhesives, paints, coating materials and the like in civil engineering and building construction fields, for having the good storage stability and the excellent curing property.
Conventionally, epoxy resins have been widely used as adhesives, sealing materials or paints in the fields of civil engineering, building construction, electronic equipment, and the like, for having excellent characteristics in adhesion, strength, and the like.
Epoxy resins have high reactivity. Therefore, when epoxy resins are mixed with an amine component, those easily react with the amine component and cure. For this reason, a two-pack epoxy resin composition comprising an epoxy resin as the main material and an amine curing agent which are separately packaged has conventionally been a main stream. A curing accelerator such as phenol or a tertiary amine is compounded with this two-pack epoxy resin composition in order to shorten a curing time, and such a blend is put into practical use. On the other hand, various investigations have been made on a one-pack epoxy resin composition using a latent curing agent mainly consisting of a ketimine compound. For example, a technique for improving the storage stability by using a ketimine compound having a larger steric hindrance is proposed. However, there is no satisfactory technique from the standpoints of the storage stability and the curing property, and any technique has not yet been put into practical use.
For example, Japanese Patent Application Laid-open No. Hei 5-132541 (hereinafter, referred to as “JP-A”) discloses a technique in which reactivity during storage is decreased by making a skeleton of a ketimine compound be a long chain polyoxylene, resulting in increasing the storage stability. However, a curing rate upon being taken out of a vessel is slow, thereby being not yet put into practical use.
On the other hand, there is proposed a technique of using a latent curing agent having a steric hindrance in which amine or thiol is capped with a trialkylsilyl group (JP-A-1-138221, JP-A-2-36220, etc.). However, since such a curing agent susceptibly reacts with even a slight amount of water, there arises such a disadvantage that the curing agent is gelled by a slight amount of water existing in a system during storage.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a one-pack epoxy resin composition having good storage stability and excellent curing property.
Another object of the present invention is to provide a one-pack epoxy resin composition having high curing rate upon being taken out of a vessel, and excellent storage stability.
The inventors of the present invention have found that in case of using a ketimine compound as a latent curing agent, the storage stability of a one-pack epoxy resin composition is improved by capping the whole or a part of hydroxyl groups existing in general-purpose epoxy resins, or by using an epoxy resin having no hydroxyl group at all in the molecule. The present invention has been completed based on this finding.
Also, the inventors of the present invention have found that in case of using a ketimine compound as a latent curing agent, the storage stability and curing property of a one-pack epoxy resin composition are improved by using an epoxy resin which has or does not have an isocyanate group, obtained by reacting a polyisocyanate compound having an isocyanate group having a larger steric hindrance with the whole or a part of hydroxyl groups existing in general-purpose epoxy resins, thereby capping the whole or a part of hydroxyl groups, and a ketimine compound having a larger steric hindrance. The present invention has been completed based on this finding.
Further, the present inventors have found that in case of using a ketimine compound as a latent curing agent, the storage stability and curing property of a one-pack epoxy resin composition are improved by reacting an alkoxysilyl group-containing compound with the whole or a part of hydroxyl groups existing in general-purpose epoxy resins, thereby capping the whole or a part of hydroxyl groups, or by using together an epoxy resin having at least two epoxy groups in the molecule, and an alkoxysilyl group-containing compound. The present invention has been completed based on this finding.
Accordingly, a first aspect of the present invention is a one-pack epoxy resin composition comprising an epoxy resin in which a content of an epoxy resin having no hydroxyl group in the molecule is in a range of from more than 90 mol % to 100 mol % or less, and a ketimine compound.
In one preferred first embodiment of the one-pack epoxy resin composition, the epoxy resin is such that hydroxyl groups of an epoxy resin having hydroxyl groups in the molecule are capped with an isocyanate group-containing compound, and the isocyanate group does not remain.
In an another preferred first embodiment of the one-pack epoxy resin composition, the epoxy resin is such that hydroxyl groups of an epoxy resin having hydroxyl groups in the molecule are capped with an isocyanate group-containing compound, and at least one isocyanate group remains in the total epoxy resins.
In a still another preferred first embodiment of the one-pack epoxy resin composition, the hydroxyl groups do not remain in the molecule of the epoxy resin containing an epoxy resin having an isocyanate group in the molecule.
In the case that the isocyanate group does not remain after reacting the isocyanate group-containing compound with hydroxyl groups of the epoxy resin, the isocyanate group-containing compound is preferably represented by the following formula (1):
R
1
: an organic group (including an organic group containing O, S or N)
R
2
: an organic group (including an organic group containing O, S or N)
R
3
: hydrogen atom or an organic group (including an organic group containing O, S or N)
n: an integer of 1 to 100,
more preferably,
R
1
: a hydrocarbon group having 1 to 5 carbon atoms
R
2
: a hydrocarbon group having 1 to 20 carbon atoms (including a hydrocarbon group containing O or N)
R
3
: hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms
In the case that the isocyanate group remains after reacting the isocyanate group-containing compound with hydroxyl groups of the epoxy resin, the polyisocyanate group-containing compound is preferably represented by the following formula (2):
R
1
: an organic group (including an organic group containing O, S or N)
R
2
: an organic group (including an organic group containing O, S or N)
R
3
: hydrogen atom or an organic group (including an organic group containing O, S or N)
n′: an integer of 2 to 100,
more preferably,
R
1
: a hydrocarbon group having 1 to 5 carbon atoms
R
2
: a hydrocarbon group having 1 to 20 carbon atoms (including a hydrocarbon group containing O or N)
R
3
: hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms
It is also preferable to conduct the reaction between hydroxyl groups of the epoxy resin having hydroxyl groups in the molecule and the isocyanate group-containing compound in the presence of a condensation catalyst.
A second embodiment of the present invention is a one-pack epoxy resin composition comprising an epoxy resin, an alkoxysilyl group-containing compound which is capable of capping hydroxyl groups in the molecule of the epoxy resin, thereby making a content of an epoxy resin having no hydroxyl group in the molecule to a range from more than 90 mol % to 100 mol % or less, and a ketimine compound.
The present invention includes a one-pack epoxy resin composition wherein the epoxy resin is such that hydroxyl groups of an epoxy resin having hydroxyl groups in the molecule are capped with the alkoxysilyl group-contai
Adachi Naoya
Okuhira Hiroyuki
Finnegan Henderson Farabow Garrett & Dunner LLP
Sellers Robert E. L.
The Yokohama Rubber Co. Ltd.
LandOfFree
One-pack composition of epoxy resin(s) with no oh groups 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 One-pack composition of epoxy resin(s) with no oh groups and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and One-pack composition of epoxy resin(s) with no oh groups and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2934621