Dental investment compounds in the form of a powder with improved flow properties

• US 5,304,239 A
• Filed: 04/05/1991
• Issued: 04/19/1994
• Est. Priority Date: 04/12/1990
• Status: Expired due to Term

• Current Assignee: Heraeus Kulzer GmbH (Mitsui Chemicals)
• Original Assignee: Bayer AG
• Inventors: Voight, Reiner, Theis, Karl-Wilhelm, Schwabe, Peter, Winkel, Jens
• Primary Examiner(s): Lieberman, Paul
• Assistant Examiner(s): EINSMANN, MARGARET V
• Application Number:
  US07/681,239
• Time in Patent Office: 1,110 Days
• Field of Search: 106/35, 103/35
• US Class Current: 106/35
• CPC Class Codes: A61K 6/858 Calcium sulfates, e.g, gypsum
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 14/304 Magnesia
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 22/143 Calcium-sulfate
• CPC Class Codes: C04B 22/16 containing phosphorus in the anion, e.g. phosphates
• CPC Class Codes: C04B 24/36 Bituminous materials, e.g. tar, pitch C04B24/243 takes precedence
• CPC Class Codes: C04B 28/14 containing calcium sulfate cements gypsum-paper plates E04C
• CPC Class Codes: C04B 28/34 containing cold phosphate binders
• CPC Class Codes: C04B 40/0608 Dry ready-made mixtures, e.g. mortars at which only water or a water solution has to be added before use

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.

Claims

1. An investment compound suitable for use in the lost wax process, which is free of an anionic surface-active agent and consists essentially of plaster or phosphate, and an iso-paraffin of the formula ##STR3## in which n denotes 2, 3, 4 or 5.

2. An investment compound according to claim 1, wherein the iso-paraffin comprises at least one of 2,2,4,4,6,6,8-heptamethyl-nonane and2,2,4,4,6,6,8,8,10-nonamethyl-undecane.

3. An investment compound according to claim 1, containing about 0.5 to 5% by weight of the iso-paraffin.

4. An investment compound according to claim 1, containing about 1.5 to 3% by weight of the iso-paraffin.

5. An investment compound according to claim 1, containing quartz, cristobalite and calcium sulphate hemihydrate.

6. An investment compound according to claim 1, containing quartz, cristobalite, magnesium oxide and ammonium phosphate.

7. An investment compound according to claim 2, containing about 1.5 to 3% by weight of the iso-paraffin.

8. 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 compound according to claim 1.