One-component reactive resin system comprising a cure-inhibiting glycidyl phosphorus compound
AssigneeSiemens Aktiengesellschaft
InventorsHeiner Bayer, Winfried Plundrich, Ernst Wipfelder
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Abstract
A one-component reactive resin system which is stable in storage but nevertheless can readily be cured completely comprises a mixture of commercially available epoxy resins and phosphorus-containing glycidyl esters, in particular phosphonic acid diglycidyl esters, as well as cationic photoinitiators. The low-viscosity reactive resin systems cannot be cured purely by means of heat and can be processed at high temperatures and in particular can have a high filler content. The reactive resin systems, which are stable to storage even after UV activation, can be cured to flame-resistant molded materials under moderate conditions.
Claims15
A one-component reactive resin system comprising:
- a phosphorus-free epoxy resin;
- a photoinitiator for a cationic curing process;
- and
- a phosphorus compound of the general formula ##STR1## in which the radicals R independently of one another are an alkyl, aryl, hydroxyalkyl or alkyloxy radical, n=2 or 3 and x=(3-n) and wherein the reactive resin system comprises the phosphorus compound in an amount of more than 5 percent by weight, said reactive resin system exhibiting non-curing thermal stability prior to photoactivation at temperatures up to about 150.degree. C. and after photoactivation exhibiting non-curing room temperature stability for a period of months and being thermally curable at temperatures of from about 100.degree. C. to about 150.degree. C.
A method for reaction injection molding comprising the steps of:
- providing a reactive resin system comprising a phosphorus-free epoxy resin, a photoinitiator for a cationic curing process, and a phosphorus compound of the general formula ##STR2## wherein R is selected from the group consisting of alkyl, aryl, hydroxyalkyl and alkyloxy radicals, wherein n=2 or 3 and x=(3-n);
- wherein said reactive resin system comprises the phosphorus compound in an amount of more than five percent by weight and exhibits non-curing thermal stability prior to photoactivation at temperatures up to about 150 degrees celsius and after photoactivation exhibits non-curing room temperature stability for a period of months while being thermally curable at temperatures of from about 100 degrees celsius to about 150 degrees celsius;
- activating the reactive resin system with ultraviolet light;
- injecting the reactive resin mixture into a mold;
- and
- curing the reactive resin mixture by heating.
A one-component reactive resin composition consisting essentially of:
- (a) from about 30 to about 90% by weight of an epoxy resin selected from the group consisting of glycidyl ethers of bisphenols, glycidyl ethers of novolaks and cycloaliphatic epoxides, optionally including a co-polymerizable compound selected from the group consisting of cyclic ethers, cyclic esters, vinyl ethers, polyether polyols and polyester polyols;
- (b) from about 0.1 to about 5% by weight of a photoinitiator for a cationic curing process, optionally including a sensitizer;
- (c) greater than about 5% by weight of a di- or triglycidyl ester of phosphonic acid;
- and
- (d) optionally, an additive selected from the group consisting of adhesion promoters, flow auxiliaries, dyestuffs, thixotropic agents and fillers, said reactive resin system exhibiting non-curing thermal stability prior to photoactivation at temperatures up to about 150.degree. C. and after photoactivation exhibiting non-curing room temperature stability for a period of months and being thermally curable at temperatures of from about 100.degree. C. to about 150.degree. C.
A one-component reactive resin composition comprising:
- an epoxy resin selected from the group consisting of glycidyl ethers of bisphenols, glycidyl ethers of novolaks and cycloaliphatic epoxides;
- a cationic photoinitiator;
- and
- a thermal cure inhibiting amount of a di- or triglycidyl ester of phosphoric acid sufficient to prevent thermal curing of the composition prior to photoactivation of the composition up to a temperature of about 150.degree. C. and after photoactivation of the composition providing non-curing room temperature stability for a period of months and permitting thermal curing at temperatures of from about 100.degree. C. to about 150.degree. C.
Dependencies are inferred from the claim text.