摘要:
A method of forming liquid crystal alignment layers of high tilt angle, said method comprising preparing a polymeric film of a monomer of the formula IV: ##STR1## wherein X and Y are strong electron withdrawing groups, optionally substituted with or containing Si or Ti, and A is --H or --CH.dbd.CH.sub.2 or, provided that X and Y are both --CN, A may be --R.sup.2 or --CH.dbd.CHR.sup.2 wherein R.sup.2 is hydrocarbyl, aryl or alkaryl; exposing said polymeric film to ultraviolet radiation for sufficient period of time to photochemically modify the polymer and, thereafter, subjecting the modified polymer to a heat treatment in the range of 100.degree.-400.degree. C. for at least 5 seconds.
摘要:
Anionically polymerizable di-.alpha.-cyanopentadienoate disiloxane compounds of the formula:[CH.sub.2 .dbd.CH--CH.dbd.C(CN)--C(.dbd.O)--O--CH.sub.2 --R--Si(R").sub.2 ].sub.2 --Owhere R is --CH.dbd.CH-- or --C(.dbd.CH.sub.2)-- and the R" groups are the same or different hydrocarbon or halo substituted hydrocarbon groups are prepared by hydrolysis of a cyanoacetoxypropenylsilane having a hydrolyzable group attached to the silicon atom and then condensing the resulting disiloxane compound with acrolein. The di-.alpha.-cyanopentadienoate disiloxane compounds are useful as instant adhesives and as co-monomers in cyanoacrylate or cyanopentadienoate instant adhesives, providing the adhesive polymers or copolymers with improved thermal resistance.
摘要:
The present invention relates to liquid stable thiol-acrylate and thiol-vinyl ether compositions. More particularly, in accordance with some embodiments, the compositions may include a (meth)acrylate, a thiol component, an organic acid stabilizer, and a curing initiator. In other embodiments, the compositions may include a curable component selected from a (meth)acrylate, vinyl ether and/or alkenyl ether, a reactive diluent having vinyl ether and acrylate functionality, a thiol component and a stabilizer selected from an organic acid, a hemiacetal ester derivative of an organic acid and/or a phenol acetal.
摘要:
The present invention relates to thiol-ene curing compositions, which cure upon exposure to ultraviolet (UV) light and/or heat. The compositions include components having alkenyl (or “ene”) functionality and components having thiol functionality, which undergo thiol-ene curing. The compositions also include a cure system. More specifically, in some embodiments, the curable compositions include a vinyl polymer bearing alkenyl or thiol terminal functional group(s) and a cross-linking agent having the opposing functionality, i.e., thiol cross-linking agents with alkenyl-terminated vinyl polymers and vinyl cross-linking agents with thiol-terminated vinyl polymers. Also provided are methods of making and using the compositions, such as for sealants for in-place gasketing applications.
摘要:
The present invention relates to photocurable elastomer compositions and methods of preparation and use of such compositions for cure-in-place applications such as gaskets. The curable compositions generally include an elastomer component, a monofunctional and/or multifunctional reactant and a photoinitiator that in various aspects may be a visible and/or UV curing initiator. The various components may be present in different amounts, depending on the combination of components and composition desired.
摘要:
The present invention relates to thiol-ene curing compositions, which cure upon exposure to ultraviolet (UV) light and/or heat. The compositions include components having alkenyl (or “ene”) functionality and components having thiol functionality, which undergo thiol-ene curing. The compositions also include a cure system. More specifically, in some embodiments, the curable compositions include a vinyl polymer bearing alkenyl or thiol terminal functional group(s) and a cross-linking agent having the opposing functionality, i.e., thiol cross-linking agents with alkenyl-terminated vinyl polymers and vinyl cross-linking agents with thiol-terminated vinyl polymers. Also provided are methods of making and using the compositions, such as for sealants for in-place gasketing applications.
摘要:
In accordance with the present invention, it has now been found that glycidyl epoxy resins containing substitution on the epoxide ring can be used with conventional epoxy curing agents and fluxing agents to produce underfill adhesives that are suitable for use with silver-based alloys. Owing to the structural similarity of the new materials to conventional epoxy resins, physical and material properties of the invention formulations are altered little, if at all, relative to products currently in use, and so are highly compatible with existing processes.
摘要:
In accordance with the present invention, it has now been found that glycidyl epoxy resins containing substitution on the epoxide ring can be used with conventional epoxy curing agents and fluxing agents to produce underfill adhesives that are suitable for use with silver-based alloys. Owing to the structural similarity of the new materials to conventional epoxy resins, physical and material properties of the invention formulations are altered little, if at all, relative to products currently in use, and so are highly compatible with existing processes.
摘要:
In accordance with the present invention, there are provided toughening agents which are useful for improving the performance properties of epoxy-based adhesive formulations. For example, epoxidized polybutylacrylates have been found to be useful toughening agents of component level underfill adhesive compositions. Invention materials are generally liquid rubbers which provided improved fracture toughness while maintaining satisfactory capillary flow properties. Invention materials can be synthesized in neat (solventless) reactions from readily available low-cost raw materials and isolated in high yields. They have a branched telechelic structure with terminal epoxide functional groups. The polyacrylate is typically obtained as a mixture of epoxidized polymer, chain extended polyoligomer and unreacted monomer. Invention materials are compatible with common epoxy formulations and may be used without purification. At low levels of incorporation, they provide adhesives that meet the minimum fracture toughness (Gq>2.0 lb/in) and capillary flow specifications (flow time
摘要:
In accordance with the present invention, there are provided gem-diesters and epoxidized derivatives thereof. When cured, thermosets comprising invention gem-diesters and epoxidized derivatives thereof have thermally and/or chemically labile gem-diester groups interspersed throughout the crosslinked network. Thus, thermosets based on invention gem-diesters and epoxidized derivatives thereof can be easily reworked thermally or chemically by treatment with dilute acidic or basic solutions. Further provided by the present invention are adhesive compositions comprising invention gem-diesters and epoxidized derivatives thereof.