Base and solvent-decomposed molding of thermosetting resin and aliphatic polyester

• US 5,990,247 A
• Filed: 02/26/1998
• Issued: 11/23/1999
• Est. Priority Date: 04/27/1994
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Terada, Takahiko, Onishi, Hiroshi
• Primary Examiner(s): Sellers, Robert E.
• Application Number:
  US09/031,404
• Time in Patent Office: 635 Days
• Field of Search: 29/403.3, 310/43, 310/208, 428/458, 525/49, 525/415, 525/425, 525/438, 525/440, 525/442, 525/443
• US Class Current: 525/415
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/18 Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/06 Unsaturated polyesters
• CPC Class Codes: H02K 15/0006 Disassembling, repairing or modifying dynamo-electric machines repairing of cooling fluid boxes H02K15/0093
• CPC Class Codes: H02K 5/02 Casings or enclosures characterised by the material thereof
• CPC Class Codes: Y10T 29/49755 Separating one material from another
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]

Abstract

The thermosetting composition of the present invention includes an unsaturated polyester, an addition polymerizable monomer, a low shrink agent other than an aliphatic polyester, and an aliphatic polyester decomposed in a decomposing solution containing a base and at least one solvent selected from the group consisting of water, methanol, ethanol, and ethylene glycol at a temperature lower than a boiling point of the decomposing solution after being cured.

Claims

1. A thermosetting composition comprising a thermosetting resin and an aliphatic polyester, wherein decomposition of the thermosetting composition is promoted by decomposition of the aliphatic polyester in a decomposing solution containing at least a base from about 0.1 to about 50% by weight of at least one base selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, alkaline earth metal oxides, alkali metal alkoxides and alkaline earth metal alkoxides;

and at least one solvent selected from the group consisting of water, methanol, ethanol or ethylene glycol after the thermosetting composition is cured.

2. A molding compound comprising as a binder a thermosetting composition containing a thermosetting resin and an aliphatic polyester,

wherein decomposition of the thermosetting composition is promoted by decomposition of the aliphatic polyester in a decomposing solution containing at least a base from about 0.1 to about 50% by weight of at least one base selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, alkaline earth metal oxides, alkali metal alkoxides and alkaline earth metal alkoxides;

and at least one solvent selected from the group consisting of water, methanol, ethanol or ethylene glycol after the thermosetting composition is cured.

3. A molding compound according to claim 2, wherein the aliphatic polyester is at least one selected from the group consisting of polycaprolactone, polypropiolactone, polyglycolic acid, polylactic acid, polyethylene adipate, polybutylene adipate, polytetramethylene adipate, polyethylene succinate, polybutylene succinate, polycaprolactonediol, polycaprolactonettiol, and poly(3-hydroxyalcanoate).

4. A method for decomposing a thermosetting composition, comprising the step of soaking a cured thermosetting composition in a decomposing solution containing a base from about 0.1 to about 50% by weight of at least one base selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, alkaline earth metal oxides, alkali metal alkoxides and alkaline earth metal alkoxides;

and at least one solvent selected from the group consisting of water, methanol, ethanol, and ethylene glycol,

wherein the thermosetting composition contains at least an aliphatic polyester and a thermosetting resin.

5. A method for decomposing a thermosetting composition according to claim 4, wherein the thermosetting composition is soaked in the decomposing solution at a temperature lower than a boiling point of the decomposing solution.

6. A method for decomposing a thermosetting composition according to claim 4, wherein the decomposing solution further contains at least one solvent selected from the group consisting of acetone, 2-butanone, dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, diethyl ether, diethylene glycol, diethylene glycol monoester, diethylene glycol diester, dicarboxylic acid diester, methyl acetate, ethyl acetate, benzene, toluene, and phenol.

7. A method for decomposing a molding compound containing as a binder a thermosetting composition, comprising the step of soaking the molding compound in a decomposing solution containing a base from about 0.1 to about 50% by weight of at least one base selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, alkaline earth metal oxides, alkali metal alkoxides and alkaline earth metal alkoxides;

and at least one solvent selected from the group consisting of water, methanol, ethanol, and ethylene glycol,

wherein the thermosetting composition contains at least an aliphatic polyester and a thermosetting resin.

8. A method for decomposing a molding compound according to claim 7, wherein the molding compound is soaked in the decomposing solution at a temperature lower than a boiling point of the decomposing solution.

9. A method for decomposing a molding compound according to claim 7, wherein the decomposing solution further contains at least one solvent selected from the group consisting of acetone, 2-butanone, dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, diethyl ether, diethylene glycol, diethylene glycol monoester, diethylene glycol diester, dicarboxylic acid diester, methyl acetate, ethyl acetate, benzene, toluene, and phenol.