Abstract: A silicone composition curing at room temperature by condensation, which is suitable especially as a dental molding composition. The silicone composition consists of the a) base paste containing a filler and polyorganosiloxane having hydroxy groups, b) and the activator component containing in addition to crosslinking agent and catalyst also a polyaddition product with alkoxysilyl groups in the molecule. The base paste and activator component can be mixed uniformly together and can be offered with special advantage in double cartridges.

Abstract: A catalyst/cross-linking agent composition, containing at least onea) vinyltrialkoxysilane as cross-linking agent,b) dialkyltin oxide as catalyst,c) optional organic acid for the control of the reaction time,d) optional inert solvent, ande) optional dye or colored pigment,is especially useful for condensation/cross-linking of polysiloxanes, such as OH-endstopped polydimethylsiloxane, in making moldings. Especially useful for impression taking in the dental field.

Abstract: It has been found that silicone resins which contain alkoxy functional groups and harden rapidly in the presence of moisture allow suitable one-component formulations as provisional fixing materials. The hardening rate can be adjusted by addition of suitable activators.

Abstract: The present invention relates to investment compounds containing zeolites and to models and moulds made from these. The investment compounds according to the invention are used in metal casting, preferably in the preparation of precision castings.

Abstract: In the preparation of a dental appliance wherein an investment compound is mixed with a liquid and then cast, the improvement wherein the investment compound is a plaster- or phosphate-bound investment compound which is free of an anionic surface-active agent and containing an iso-paraffin of the formula ##STR1## in which n denotes 2, 3, 4 or 5.

Abstract: A method of making a dental impression which comprises applying to the structure of which an impression is to be made a special prepolymer. The prepolymer is composed of units of at least one macrodiol, at least one aliphatic polyisocyanate, and an unsaturated monoalcohol as chain terminator, wherein the average functionality of the prepolymer based on the unsaturated groups is >2.

Abstract: A process for the preparation of a dental impression comprisingA) forming a mixture of a polyaddition product which contains ether, urethane and urea groups,B) mixing therewith water of proton donor-containing aqueous solution in a weight ratio of A:B of from 1:0.01 to 1:40 and in at least catalytically active amount, the weight ratio of water plus proton donor to the balance of the composition exclusive of the filler ranging from about 0.01:1 to 1:1, andC) applying the mixture formed in B intraorally to a patient to make a negative copy of the patient's teeth.

Abstract: A hard, resistant material formed by mixing and curinga) at least one polyfunctional silicopolyether,b) at least one monomer which can be subjected to free-radical curing,c) at least one catalyst for polymerization of the free-radical monomers at high temperature, low temperature or under the influence of light, andd) at least one catalyst for the condensation of the silicopolyether.

Abstract: The present invention relates to optically clear polysiloxane-based compositions which are employed, in particular, for the production of contact optical articles such as contact lenses, scleral lenses and intraocular lenses.

Abstract: In a dental composite containing a polymerizable (meth)acrylic compound, photoinitiator, accelerator, inorganic filler and conventional auxiliaries, the improvement wherein the composite by weight comprises about(a) 10-50% of at least one monomer which contains at least 2 polymerizable (meth)acrylic acid groups,(b) 5-80% of a glass or a glass ceramic which has an average particle size of between about 0.1 and 10 .mu.m and has been post-treated with .gamma.-methacryloxypropyltrimethoxysilane up to a carbon content of between about 0.5 and 2.5% by weight,(c) 2-10% of a surface-treated microfiller and(d) 0.1-5% of a photoactivator consisting of a mixture of camphorquinone and p-dialkylaminobenzenesulphonamide. The composition has a long pot life and good surface color when cured.

Abstract: In a silicone impression and duplicating composition which undergoes crosslinking at ambient temperature by an addition reaction, comprising(a) an organopolysiloxane possessing two or more vinyl groups in the molecule,(b) optionally an organopolysiloxane without reactive groups,(c) an organopolysiloxane possessing two or more Si-H groups in the molecule,(d) a catalyst,(e) a filler and,(f) optionally an auxiliary and/or colorant, the improvement wherein polysiloxane components (a)-(c) contain not more than about 1.5% by weight of volatile oligomers, whereby the dimensional stability of impressions is improved.

Abstract: An addition or condensation cross-linking molding or lining compound based on silicones comprising(a) an organo polysiloxane containing reactive end groups,(b) a catalyst,(c) a filler, and(d) an isoparaffin having 8 to 24 carbon atoms.The compounds being particularly useful as dental molding compositions.

Abstract: Colored silicone composition comprising:(a) at least one organopolysiloxane,(b) at least one isoparaffin having 8 to 24 carbon atoms, and(c) a dyestuff soluble in (b).

Abstract: In the making of an impression wherein an impression material comprising an alginate, a pulverulent material and a dust-reducing coating is mixed with water to form a paste, the paste is positioned about a mold member, and permitted to harden, the improvement wherein such coating comprises an iso-paraffin. There is reduced dusting.

Abstract: Impression material in the form of a powder, which, on mixing with water, provides a paste which cures to a solid consistency, the material in the form of a powder being made dust-free by additions of a coating agent, which material is characterized in that it contains paraffin as an additive.

Abstract: The present invention relates to the use of paraffin waxes or microwaxes in silicone pastes, in particular in kneadable compositions for the production of accurate impressions of teeth. The silicone pastes are preferably cold-vulcanizing two-component silicone rubber systems which are known per se and in which two pastes are mixed and then crosslink after about 2-5 minutes at room temperature.

Abstract: In the making of a shaped structure by mixing(a) a cross-linkable organopolysiloxane,(b) hydrophobic filler particles,(c) paraffin oil,(d) a colorant, and(e) a cross-linking catalyst,the improvement which comprises employing as (b) hydrophobic filler particles of which the surface has been laden with 0.5-5% by weight of paraffin oil. The filler can be present in either or both of a cross-linkable silicone component and a catalyst component; each component can contain other ingredients but will not cure until the two components are brought together. Truer dental impressions are thereby formed.

Abstract: In a polysiloxane-based composition which crosslink by addition, comprising (a) an organosiloxane with two or more vinyl groups in the molecule, (b) and organo-hydridopolysiloxane, as a crosslinking agent, (c) a catalyst for accelerating the addition reaction, (d) a hydrophobic filler and (e) optionally a dyestuff pigment, the improvement which comprises (f) hydrogenated castor oil as a structuring agent. The composition is highly viscous and will not run but can readily be stirred.

Abstract: A process for producing an inorganic-organic composition material based on gypsum and polyurethane comprising exposing calcined gypsum or anhydrite to the action of water in the presence of a polyurethane or polyurethane-urea which is dispersible in water and in the presence of up to about 20% by weight (relative to the total mixture) of an alcohol and up to about 20% by weight (relative to the total mixture) of another organic solvent, and allowing the composition to set while permitting any solvents which may be present to evaporate. The calcium sulphate may be on a textile support or the composition may be molded into flexible shaped articles of good mechanical properties.

Abstract: Contact lenses and contact shells of light-refracting material consisting essentially of a copolymer of(I) from 40 to 90% by weight of methyl methacrylate and(II) from 10 to 60% by weight of methyl acrylate and/or esters corresponding to formula (1): ##STR1## in which R represents H or CH.sub.3,R' represents H, CH.sub.3 or C.sub.2 H.sub.5 andn=1 or 2,the sum of I and II amounting to 100% by weight.