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
2000-10-06
2003-03-04
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...
C523S451000, C525S481000, C525S487000, C525S488000, C525S490000, C525S496000, C525S497000, C525S510000, C525S523000, C525S533000, C524S109000, C524S119000, C524S147000, C524S151000, C524S153000, C528S109000, C528S380000
Reexamination Certificate
active
06528595
ABSTRACT:
TECHNICAL FIELD
This invention relates to various resin compositions comprising a resin component containing compound (A) wherein or a part of oxirane ring in an epoxy compound is replaced with thiirane ring; or the compound (A) and compound (B) which contains oxirane ring and no thiirane ring in the molecule.
More specifically, this invention relates to:
(i) an adhesive composition comprising the resin component as described above;
(ii) a resin composition for a sealant exhibiting excellent adhesion and tensile strength comprising the resin component as described above and another particular resin;
(iii) a resin composition for a coating composition and a coating agent comprising the resin component as described above exhibiting excellent curability, adhesion to adherend, and reduced odor without detracting from pot life;
(iv) a resin composition for electric applications comprising the resin component as described above which quickly develops electric insulation, which exhibits flame retardancy, excellent curability and strong adhesion to metal substrate, and which can be used for potting of print circuit boards and as a resin for impregnation in prepregs;
(v) a resin composition comprising the resin component as described above exhibiting excellent fast curing, and in particular, fast curing at low temperatures as well as high storage stability at high temperatures;
(vi) a resin composition suitable for use as an adhesive and the like comprising the resin component as described above and a particular phosphite ester, which exhibits excellent adhesion, curability at low temperatures, reduced odor, and good storage stability;
(vii) a fast curing, one part resin composition suitable for use as a coating composition, adhesive and the like comprising the resin component as described above and a particular ketimine, which exhibits excellent curability at low temperatures and storage stability; and
(viii) a resin composition further comprising a reactive diluent capable of reducing viscosity of the composition, and which exhibits no clouding of the composition by the crystallization of the resin component as described above.
BACKGROUND ART
Epoxy resin-based adhesives are widely used in various industrial fields since they exhibit satisfactory adhesion to a variety of materials such as metals, plastics, woods, glass, concrete, and ceramics, and at the same time, excellent heat resistance, chemical resistance, electric insulation, and the like. Accordingly, they are used as an adhesive for supporting the structure of automobiles and airplanes, and as an adhesive for civil engineering and construction purposes.
Recently, epoxy resin-based adhesives are also finding their use in the field of electrical and electronic engineering since they are excellent in properties such as heat resistance band electric insulation and the gas generated and shrinkage in the course of curing are reduced.
For example, Epoxy resin-based adhesives are used as a potting agent for physical and chemical protection and fixation of print circuit boards and as a resin for impregnation in prepregs. As a consequence of such widening in the range of their application, there is a demand for epoxy resin-based adhesives to have further improved electric insulation, flame retardancy, and adhesion. There is also a demand for further reduction in curing time without detracting from their electric insulation for the purpose of shortening the production period.
In spite of such situation, most of the conventional epoxy resin compositions have been two part compositions comprising the main part and the curing agent. Such two part compositions suffer from short pot life since the curing reaction starts immediately after the mixing of the components, and as a consequence, the composition suffered from poor workability.
A typical method for extending the pot life is use of a latent curing agent, for example, a block isocyanate-modified epoxy resin. A latent curing agent, however, is an agent primarily developed for curing by heat application, and the performance upon drying at room temperature has been far from being acceptable for practical use. Another method is use of a resin with low reactivity, for example, an aliphatic epoxy resin for the main part. This method, however, suffers from reduced working efficiency due to inferior drying properties and markedly delayed formation of the surface film despite the extended pot life.
The composition can be imparted with fast curing properties when a thiol compound is used as a curing agent. Thiol compounds, however, suffer from bad odor and use of such compounds invites worsening in the work environment.
Adhesive strength of the epoxy resin-based adhesives has been conceived to be developed mainly by the hydroxyl group which is generated as a result of the curing reaction. This hydroxyl group, however, has low reactivity (acidity), and the adhesive strength is believed to be developed by physical affinity. Accordingly, introduction in the molecule of a highly reactive functional group which can generate a substituent having a chemical reactivity higher than that of the hydroxyl group upon curing may result in the production of an adhesive which exhibits stronger adhesive strength and faster curing compared to the conventional epoxy resin-based adhesives or a coating composition, a coating agent, or a potting agent which exhibits stronger adhesion or bonding to the substrate as well as faster curing compared to the conventional epoxy resin composition.
In the case of the two part, room temperature-curable epoxy resin-based adhesive used in outdoors, balance between the pot life and the curing speed is important. The adhesives wherein an aliphaticpolyamine is used for the curing agent had the merit of high curing speed while they suffered from short pot life. On the other hand, the adhesives wherein an alicyclic polyamine compound is used for the curing agent had the merit of extended pot life and reduced heat generation while they suffered from low curing speed and difficulty in curing at low temperatures.
Thiirane-containing resin wherein oxirane ring of the epoxy resin is replaced with thiirane ring exhibits higher reactivity and faster curing speed at low temperatures since thiirane ring has a reactivity higher than the oxirane ring because of the higher distortion of the thiirane ring compared to the oxirane ring. Such thiirane-containing resin also exhibits low temperature curability, good adhesion and reduced odor since the thiol group generated by the ring opening is a substituent having a high chemical reactivity. Thiirane-containing resin, however, suffered from poor storage stability, and in particular, from poor storage stability at a high temperature, for example, at 60° C. because of the high chemical reactivity of the thiol group.
JP-A 10-130513 discloses a method for preventing alteration in quality of mercapto group (—SH)-containing polymer wherein a primary antioxidant such as an alkylphenol-based oxidant or an amine-based oxidant and a secondary antioxidant such as a sulfur-based antioxidant or a phosphorus-based antioxidant are simultaneously incorporated in the polymer to suppress the oxygen concentration of the gas phase part below the predetermined volume. However, incorporation in the thiirane-containing resin of an alkylphenol compound which is a versatile antioxidant proved to have no influence in improving the storage stability.
JP-A 5-132541, JP-A 5-230182 and the like disclose one-part epoxy resin compositions wherein the epoxy resin has a ketimine compound blended therewith as a latent curing agent. Ketimine compound, however, suffers from a drawback that amine which generates in the course of the hydrolysis (equilibrium) reaction in the presence of water contributes for the curing reaction and as a consequence, the curing proceeds at an extremely slow speed, and in particular, the resin does not cure at a low temperature, for example, at a temperature not more than 5° C.
On the other hand, a thiirane-containing resin wherein oxirane ring of an epoxy
Chino Keisuke
Ikawa Masahiro
Okuhira Hiroyuki
Finnegan Henderson Farabow Garrett & Dunner LLP
Sellers Robert E. L.
The Yokohama Rubber Co. Ltd.
LandOfFree
Adhesive of thiirane and oxirane-containing compound 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 Adhesive of thiirane and oxirane-containing compound and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adhesive of thiirane and oxirane-containing compound and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3068682