Method of heat-sealing substrates
AssigneeFraunhofer-Gesellschaft
InventorsHelmut Schmidt, Gerhard Tunker, Horst Scholze
Life of this patent
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Abstract
A method of heat-sealing substrates, particularly glass to glass or glass to other materials, which comprises using as a heat-sealing medium a silicic acid heteropolycondensate prepared by hydrolysis and polycondensation of at least one organosilane and at least one component selected from the group consisting of silicon-functional silanes, substantially involatile oxides soluble in the reaction medium, or compounds convertible thereto, and organofunctional silanes. The heat-sealing bonds obtained are strong, durable and moisture resistant, the excellent moisture resistance being of special benefit in the heat-sealing of glass substrates.
Claims39
A method for heat-sealing a first glass substrate to a second substrate, comprising the steps of:
- applying to said glass substrate or to said second substrate, without previously coating said glass substrate with an adhesion promoter, a heat sealing adhesive consisting essentially of a thermoplastic heteropolycondensate prepared by hydrolysis of and polycondensation of:
- (a) 20 to 95% by weight of at least one organosilane of the general formula (I):
- R.sub.m SiX.sub.4-m (I),
- wherein R is alkyl, alkenyl, aryl, alkylaryl, or arylalkyl;
- X is hydrogen, halogen, hydroxyl, alkoxy, acyloxy, or a group --NR'.sub.2 wherein R' is hydrogen and/or alkyl;
- and m is an integer of 1, 2 or 3;
- with at least one of the following components (b), (c) and (d), the total concentration of components (b), (c) and (d) being at least 5% by weight:
- (b) 0 to 40% by weight of one or more silicon-functional silanes of the general formula (II):
- SiX.sub.4 (II)
- wherein X is as defined above, with the proviso that not all of substituents X are hydrogen;
- (c) 0 to 40% by weight of one or more substantially involatile oxides soluble in the reaction medium, or one or more compounds capable of forming such substantially involatile oxides, of an element selected from Groups Ia to Va or IVb and Vb of the Periodic Table;
- and
- (d) 0 to 20% by weight of one or more organofunctional silanes of the general formula (III):
- R.sub.n (R"Y).sub.p SiX.sub.(4-n-p) (III),
- wherein R and X are as defined above;
- R" is straight chain or branched alkylene optionally interrupted by oxygen or sulfur atoms or --NH--groups, phenylene, alkylphenylene, or alkylenephenylene;
- Y is halogen, unsubstituted or substituted amino, unsubstituted or substituted anilino, aldehyde, keto, carboxyl, hydroxyl, mercapto, cyano, hydroxyphenyl, carboxylic acid alkyl ester, sulfonic acid, phosphoric acid, acryloxy, methacryloxy, glycidyloxy, epoxy, or vinyl;
- n is an integer of 0, 1 or 2;
- and p is an integer of 1, 2 or 3, the sum of n+p being an integer of 1, 2 or 3;
- in the presence of at least the stoichiometric amount of water required for hydrolysis, and optionally in the presence of a condensation catalyst and/or solvent, wherein in the case of starting components (a) and (d), oligomers of these silanes which are soluble in the reaction medium may also be used;
- and heat sealing said glass substrate to said second substrate.
Dependencies are inferred from the claim text.