IMPROVED CATALYTIC POLYMERIZATION ACCELERATOR SYSTEMS

Abstract: Artificial human nail structures. The structures preferably comprise polymerized alkyl methacrylate and hydroxyalkyl methacrylate, wherein polymerization of the structure is accomplished by a catalyst of barbituric acid. The structures and compositions of the present invention produce hard, strong and flexible artificial nails without the dangers of pharmacological activity displayed by prior art catalysts.

Description: IMPROVED CATALYTIC POLYMERIZATION ACCELERATOR SYSTEMS Field of the Invention This invention relates generally to bonding materials for use in artificial nails. Mor particularly, this invention relates to safe catalysts for curing bonding materials in artificial nails. Background of the Invention In the past, polymers for producing artificial nails have been created which promote fast and strong hardening of the artificial nails when they are applied to the nail bed. Typically, catalysts, initiators and accelerators are used in either chemical polymerization systems or photopolyraerization systems to promote fast and strong hardening. Previously, organic peroxides have been used to obtain catalytic action in artificial polymers. For example, benzoylperoxide and toluidincs in about 0.25% to 1.0% by weight in the polymer is an effective catalyst. However, certain jurisdictions do not allow the use of benzoylperoxide and toluidine and so it is desired to obtain alternatives to such a catalyst in artificial nails. See. for example. U.S. Patent Nos. 5.523,076 and 5,098,696, the teachings of which are specifically incorporated herein by reference. In the dental art, tooth surface treating agents and hardening agents are similarly employed to obtain favorable results for artificial teeth, dentures, and other materials. One highly efficient system for curing dental polymers employs barbituric acids and derivatives thereof as photo and - 1 - chemical catalysts for dental polymers. Barbituric acid derivatives are expressed by the following general formula: R 1 I 0 . ---• N ^ __ 0 ^ r Tv \ o (where Rl, R2 and R3 may be the same or different and each may represent an aliphatic, aromatic, alicyclic, or heterocyclic residue or hydrogen atom which may have a substi-uenx, such as a halogen atom, alkyl group- aloxy group, aryl group, or cyclohexyl). Specifically, the following non-limiting list of barbituric acid derivatives is applicable: barbituric acid, 1,3-dimethylbarbituric acid. 1.3- diphenylbarbituric acid, 1,5- dimethylbarbi uric acid, 5-butylbarbit-tric acid, 5-ethylbarbituric acid 5-isopropylbarbituric acid, 5-cyclohexylbarbituric acid, 1,3,5-trimethylbarbituric acid, 1,3-dimethyl- 5-ethylbarbituric acid, 1,3-dimethyl-n-butylbarbituric acid, l,3-dimethyl-5-isobutylbarbituric acid, l,3-dimethyl-5-tert-butylbarbituric acid, 1 -dimethyl-5-cyclope---tylba_bituric cid, l,3-dimethyl-5- cyclohexylbarbituricacid, l,3-dimethyl-5-phenylbarbituricacid, l-cyclohexyl-5-ethylbarbituric acid, 1 -benzyl- 5-phenylbarbituric acid, and thiobarbituric acids; and salts thereof. These compounds are taught in U.S. Patent No. 5,707,611, the teachings of which are specifically incorporated herein by reference. The use of barbituric acids in dental applications is also described in U.S. Patents 5,663,214; 4,906,446; and 4,115,346, the teachings of which are specifically incorporated herein by reference. It would be desirable to employ catalyst systems which do not display pharmacological activity in making artificial fingernails. This has not heretofore been achieved in the art. 2 - Summary of the Invention The aforementioned long-felt needs are met and problems solved by artificial human nail structures provided in accordance with the present invention. The structures pτeferably comprise polymerized alkyl methacrylate and hydroxyalkyl methacrylate, wherein polymerization of the structure is accomplished by a catalyst of barbituric acid. The structures and compositions of the present invention produce hard, strong and flexible artificial nails without the dangers of pharmacological activity displayed by prior art catalysts. Detailed Description of Preferred Embodiments As described in the aforementioned U.S. Patent Nos. 5.523.076 and 5.098,696 artificial nail structures and compositions for making artificial nail structures are generally comprised of a two- part system. The system consists of a liquid portion or binder, and a powder portion or polymeric powder. The liquid binder consists of a monomeric acrylate or methacrylate ester, and a di-, tri-, or multifiinctional acrylate or methacrylate ester, and a tertiary amine accelerator. The powder portion generally comprise a polymeric methacrylate or copolymeric methacrylate and an initiator or catalyst such as a peroxide polymerization initiator, for example benzoyl peroxide. The tertiary amine accelerator and benzoyl peroxide initiators exhibit pharmacological activity and therefore, it is desired to replace them with a non-pharmacological catalysts. In accordance with the present invention, the catalyst is barbituric acid, as described generally above. A delivery system is also contemplated in accordance with the present invention. The delivery system preferably makes use of porous or hollow polymers that may contain the catalytic components separately. These materials can adsorb and/or absorb the catalyst components and then be blended into the methylmethacrylate ethylmethacrylate polymer. This may deliver a more stable - 3 - catalytic system as well as maintaining desirable bulk appearance and workability qualities of the polymer. Example The inventor of the present subject matter believes that the following prophetic example will produce compositions of particular utility in the artificial fingernail art. Liquid Binder Ethyl methacrylate 90% Ethylene glycol dimethacrylate 6.9% 1 ,3 ,5-trimethyl barbaturic acid 3.1% MEHQ lO ppm Polymeric Powder Poly(ethyl methacrylate) 98.8% Tert-butyl perbenzoate 1.0% Iron chloride 0.2% It is expected that the above formulation when combined will polymerize to an artificial fingernail material. ■ 4 - SUBST1TUTE SHEET (RULE 26)

Claims: What is claimed is: 1. An artificial human nail structure comprised of polymerized alkyl methacrylate and hydroxyalkyl meth--crylatc, wherein polymerization of the structure is accomplished by a catalyst of barbituric acid. - 5 -

Inventors: RANEY ROBERT, RANEY, ROBERT
Applicants: MYCONE DENTAL SUPPLY COMPANY I, RANEY ROBERT, WALDREN ROBIN MICHAEL, MYCONE DENTAL SUPPLY COMPANY, INC., RANEY, ROBERT, WALDREN, ROBIN, MICHAEL
Application year: 1998
Main classification: A61K7
IPC codes: A45D31, A61K8, A61Q3