Coating processes – Applying superposed diverse coating or coating a coated base – Synthetic resin coating
Patent
1998-02-18
2000-04-04
Marquis, Melvyn I.
Coating processes
Applying superposed diverse coating or coating a coated base
Synthetic resin coating
525522, 525528, 525530, B05D 136
Patent
active
060458739
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a novel one-packed epoxy resin composition and a one-packed anticorrosive paint composition which have excellent storage stability and are capable of forming coatings excellent especially in adhesion and drying characteristics, and a coating method using the compositions.
BACKGROUND ART
Epoxy resins have been used in various fields such as coating compositions, sealing agents, adhesives and the like, because of their excellent properties, in particular, their high adhesion. However, most of conventionally used epoxy resin compositions are two-packed compositions consisting of a main agent and a curing agent. Since the curing reaction starts immediately after mixing the main agent and curing agent, the two-packed epoxy resin compositions have a very short pot life, resulting in poor workability.
Method were proposed for extending the pot life, for example by adding a latent curing agent such as blocked isocyanate to an epoxy resin. However, the latent curing agent is inherently of a heat-curing type, and is not practically usable for curing by ordinary temperature drying. The present applicant proposed in Japanese Examined Patent Publication No. 32231/1987 a method for preventing corrosion using a coating composition comprising an epoxy resin, a ketimine compound and a dehydrating agent. However, the composition, when used as a two-packed type, has poor drying characteristics and a very low curing rate, although having a prolonged pot life. On the other hand, when the composition is used as a one-packed type, it has insufficient storage stability.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a one-packed epoxy resin composition and a one-packed anticorrosive paint composition which are free from the above drawbacks of the prior art, and a coating method using the compositions.
Another object of the present invention is to provide a one-packed epoxy resin composition and a one-packed anticorrosive paint composition which are excellent in storage stability, workability and the like and are capable of forming coatings excellent in drying characteristics, overcoatability, adhesion and the like, and a coating method using the compositions.
Other features of the invention will be apparent from the following description.
The present invention provides:
(A) an epoxy resin having two or more epoxy groups in its molecule and a number average molecular weight of 250 to 4,500,
(B) a ketimine compound,
(C) a dehydrating agent, and
(D) at least one modified epoxy resin (d-1) selected among urethane-modified epoxy resins, amine-modified epoxy resins and dimer acid-modified epoxy resins, and/or a resin (d-2) which has a softening point of 60.degree. C. or above and is at least one member selected among xylene resins, ketone resins, coumarone resins and petroleum resins; one-packed epoxy resin composition and (E) a zinc dust in such an amount as to be present in a proportion of 20 to 95 wt. % in the heat-cured coating film; and substrate and conducting topcoating, wherein the above one-packed epoxy resin composition or the above anticorrosive paint composition is used as the undercoating composition.
The present inventors carried out extensive research and found that the above objects can be achieved when the above specified modified epoxy resin and/or xylene resin or like resin are mixed with a composition containing an epoxy resin, a ketimine compound and a dehydrating agent. The present invention has been accomplished based on this novel finding.
The present invention will be described below in further detail.
The component (A) of the resin composition of the invention is an epoxy resin having two or more, preferably 2 to 5 epoxy groups in its molecule and a number average molecular weight of about 250 to 4,500, preferably about 350 to 3,000. A suitable epoxy equivalent of the epoxy resin is about 80 to 2,200, preferably 170 to 1,500.
Examples of the epoxy resin (A) include epoxy resins obtained by reacting a polyvalent alcohol
REFERENCES:
patent: 5357008 (1994-10-01), Tsai et al.
Adachi Yoshimitsu
Hamamura Toshihiro
Aylward D.
Kansai Paint Company Limited
Marquis Melvyn I.
LandOfFree
One-pack epoxy resin composition, one-pack corrosion resistant p 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 epoxy resin composition, one-pack corrosion resistant p, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and One-pack epoxy resin composition, one-pack corrosion resistant p will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-362873