Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/22—Di-epoxy compounds
  • C08G59/30—Di-epoxy compounds containing atoms other than carbon, hydrogen, oxygen and nitrogen
  • C08G59/306—Di-epoxy compounds containing atoms other than carbon, hydrogen, oxygen and nitrogen containing silicon
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/32—Epoxy compounds containing three or more epoxy groups
  • C08G59/3254—Epoxy compounds containing three or more epoxy groups containing atoms other than carbon, hydrogen, oxygen or nitrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
  • C08L83/06—Polysiloxanes containing silicon bound to oxygen-containing groups

Definitions

• the invention relates, generally, to electron-beam (e- beam) cure of epoxy compositions and specifically to deep- section, e-beam cure of herein disclosed epoxy monomers.
• E-beam curing is most widely applied to the cure of coating materials which are either heavily pigmented or are comparatively thick in crossection, such as cable insulation.
• ultraviolet radiation-induced polymerization is impractical whereas the great depth of penetration of the electron radiation permits the polymerization of these substrates with relative ease.
• E-beam curing is most widely applied ' to multifunctional acrylate and methacrylate monomers and polymerization results by a free radical mechanism initiated by solvated electrons and free radicals produced by bond scission in the monomers
• the use of multifunctional acrylate and methacrylate monomers for e-beam curing suffers from the fact that these materials a e costly, toxic and require an inert atmosphere foi theiir proper cure.
• the cost of nitrogen used as an inert atmosphere may render this process economically disadvantageous.
• Acrylate and methacrylate based monomers also may not have the requisite properties to meet demanding applications.
• One such application lies in the area of composites fabrication. In this application, excellent thermal resistance, adhesion to the fiber reinforcements and superior mechanical properties of the cured resin is required. These properties have not been obtained using acrylate and methacrylate monomers.
• Epoxy compositions are characterized by multifunctional cycloaliphatic epoxy monomers or polymers together with an onium salt initiator possessing metal halide anions.
• the epoxy compositions are cured by e-beam, x-ray and ⁇ -ray irradiation methods. These compositions represent a breakthrough in epoxy resin technology and have major applications as coatings, inks, adhesives, composites, fiber optics, electronic packagings and photoresists for integrated circuits. Composites applications, in particular, represent a new and enormously important area for application of this technolog .
• the polymerization of these monomers using UV and visible light requires the use of an onium salt photoinitiator.
• diazonium, diaryliodonium, triarylsulfonium, triarylselenonium, diaryliodonium, triarylsulfonium, triarylselenonium, diaryliodosonium, triarylsulfoxonium, diarylbromonium, diarylchloronium and phenacylsulfonium salts can be used. Since the photoresponse of these monomers was so high, it was decided to employ these monomers in e- beam curing.
• Samples to be irradiated were coated onto 2 mil pol (ethylene terephthalate) film using 1 and 3 mil drawknives.
• An Energy Sciences Electocurtain Model CB-150 electron beam irradiator operating at 165 KeV and equipped with a 15 cm linear cathode was used to irradiate the samples.
• the wet film samples were attached to a continuous web and passed through the beam. Experiments were run under nitrogen and air at a constant web speed. The dose was varied by changing the amperage applied to the filament. Glass Transition Temperature Measurements
• Tg measurements were made at 20°C/minute using a Perkin- Elmer DSC-7 Differential Scanning Calorimeter.
• I undergoes facile e-beam induced cationic polymerization in the presence of diaryliodonium and triarylsulfonium SbFg " salt photoinitiators. When these photoiniators are omitted, no polymerization occurs. Transparent, colorless films were obtained which were crosslinked and completely insoluble in all solvents. In the case of diphenyliodonium SbFg " , minimum dose rates as low as 1 Mrad were effective in initiating polymerization at photoinitiator concentrations of 0.5 mole percent; however, 2 Mrad consistently gave completely tack- free coatings.
• Silicone-epoxy monomers are more reactive than simple epoxy monomers such as I in photoinitiated cationic polymerization using onium salts; and this was also observed in their e-beam cure.
• the minimum dose required to cure a 1 mil liquid film of difunctional silicone-epoxy monomer II on a glass substrate in nitrogen to a tack-free state using 0.5 mole % (4-C ⁇ H- j7 OPh)PhI + SbFg " was determined and found to be 1 Mrad. Cured films of this polymerized monomer are transparent, colorless, hard and brittle. Using a dose of 2 Mrad, films 6 mil in thickness were cured.
• a 2 Mrad dose is sufficient to completely crosslink monomer II in the presence of as little as 0.25 mole % diphenyliodonium SbFg " . Again, polymerization was not observed when this monomer is irradiated in the absence of an onium salt initiator.
• the glass transition temperature (Tg) for this polymer was 181° C. The excellent high Tg is characteristic of cured epoxy silicone resins and is extremely important for their use in a wide variety of applications, but most particularly in composites.
• the range of onium salts which can be applied to this invention is large and comprises diazonium, diaryliodonium, triarylsulfonium, triarylselenonium, diaryliodosonium, triarylsulfoxonium, diarylbromonium, diarylchloronium and phenacyldialkylsulfonium, benzyldialkylsulfonium and hydroxyphenyldialkylsulfonium salts.
• those bearing the SbFg" anions are preferred.
• the e-beam curing compositions may also include a wide assortment of fibrous and particulate fillers, adhesion promoting agents, pigments, dyes and flating or leveling agents.
• the novel e-beam curable epoxy monomers and oligomers can be applied to a wide diversity of applications. Among those which may be mentioned are decorative, protective and insulating coatings for wood, glass, metals and plastics, printing inks and adhesives. One recent application which is being considered is the use of e-beam curable inks for the rapid non-polluting printing of currency and stamps. Silicone epoxy monomers, in addition to being rapidly curing are non-toxic . Other monomers whose structures are also described in this disclosure should also be similarly non- toxic.
• the monomers and oligomers described in this disclosure have the requisite high temperature properties (Tg's), as well as excellent solvent resistance and mechanical properties. Furthermore, the use of e-beam curing avoids the high temperatures and long times used in conventional composites fabrication and has the potential of greatly improving the mechanical properties of the final composite. This is achieved as a result of curing at room temperature which reduces the mechanical strain in the composites which results from a mismatch of the coefficients of thermal expansion between the matrix and the fiber reinforcements.
• R is an alkylene

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Epoxy Resins (AREA)

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• 1991
  • 1991-11-22 EP EP19920902738 patent/EP0544842A4/en not_active Withdrawn
  • 1991-11-22 WO PCT/US1991/008800 patent/WO1992012183A1/en not_active Application Discontinuation

Patent Citations (5)

Non-Patent Citations (2)

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