Process for reducing the microbe count in aqueous multi-phase compositions that contain synthetic resin

• US 5,529,749 A
• Filed: 12/02/1994
• Issued: 06/25/1996
• Est. Priority Date: 12/13/1993
• Status: Expired due to Fees

• Current Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Original Assignee: Hoechst Aktiengesellschaft (Sanofi )
• Inventors: Rinno, Helmut, Alberti, Klaus, Hessel, Friedrich
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Snider, Theresa T.
• Application Number:
  US08/353,243
• Time in Patent Office: 571 Days
• Field of Search: 422/21, 528/503, 523/122, 427/488, 427/508, 427/516, 427/544, 427/553, 427/561, 204/157.15, 204/158.21
• US Class Current: 422/21
• CPC Class Codes: A61L 2/12 Microwaves
• CPC Class Codes: B29B 13/08 by using wave energy or particle radiation

Abstract

A process is disclosed for reducing the microbe count in microbially-contaminated aqueous multi-phase composition containing synthetic resin, such as polymer dispersions and formulations that contain polymeric binders. The process uses dielectric heating, preferably immediately before transfer of the multi-phase composition to containers.

Claims

1. A process for treating a microbially-contaminated aqueous multi-phase composition that contains synthetic resin, the process including the steps of:

providing an aqueous multi-phase composition that contains a synthetic resin;

microwave heating the aqueous multi-phase composition under an autogenous pressure of up to 10 bar to destroy microbes therein; and

immediately transferring the heated aqueous multi-phase composition into containers under substantially sterile conditions.

2. A process as claimed in claim 1, wherein the dielectric heating is carried out by means of a microwave apparatus.

3. A process as claimed in claim 2, wherein the microwave apparatus is operated at a frequency is 0.04 to 24 GHz to achieve microwave heating.

4. A process as claimed in claim 2, wherein the aqueous multi-phase composition flows continuously through the microwave apparatus.

5. A process as claimed in claim 1, wherein the aqueous multi-phase composition is subjected by the microwave heating to a sterilization temperature of below 121°

C.

6. A process as claimed in claim 5, wherein the sterilization temperature is between 50°

and 100°

C.

7. A process as claimed in claim 1, wherein the aqueous multi-phase composition comprises a polymer dispersion.

8. A process as claimed in claim 7, wherein the polymer dispersion comprises an emulsion polymer that contains acrylate or vinyl acetate groups.

9. A process as claimed in claim 1, wherein the aqueous multi-phase composition is a formulation that contains a polymer dispersion.

10. A process of treating a microbially-contaminated aqueous multi-phase composition that contains synthetic resin, the process including the steps of:

providing an aqueous multi-phase composition that contains a synthetic resin;

microwave heating the aqueous multi-phase composition to destroy microbes therein; and

adding a microbicide to the aqueous multi-phase composition, the amount of microbicide added being less than 50% of the amount of microbicide necessary to achieve sterilization for an identical aqueous multi-phase composition which has not been subjected to microwave heating.

11. A process for treating a microbially-contaminated aqueous multi-phase composition that contains synthetic resin, the process including the steps of:

providing an aqueous multi-phase composition that contains a synthetic resin selected from the group consisting of homo- and copolymeric polyvinyl acetates, polymers of esters of acrylic acid or methacrylic acid with and without a protective colloid, polystyrene, copolymers of styrene and esters of acrylic/methacrylic acid, polybutadiene and copolymers of styrene and butadiene, and aqueous dispersions of polycondensation products; and

microwave heating the aqueous multi-phase composition under an autogenous pressure of up to 10 bar to destroy microbes therein.

12. A process as claimed in claim 11, wherein the microwave heating is carried out by means of a microwave apparatus.

13. A process as claimed in claim 12, wherein the microwave apparatus of operated at a frequency is 0.04 to 24 GHz to achieve microwave heating.

14. A process as claimed in claim 12, wherein the aqueous multi-phase composition flows continuously through the microwave apparatus.

15. A process as claimed in claim 11 wherein the aqueous multi-phase composition is subjected by the microwave heating to a sterilization temperature of below 121°

C.

16. A process as claimed in claim 15, wherein the sterilization temperature is between 50°

and 100°

C.

17. A process as claimed in claim 11, wherein the aqueous multi-phase composition comprises a polymer dispersion.

18. A process as claimed in claim 17, wherein the polymer dispersion comprises an emulsion polymer that contains acrylate or vinyl acetate groups.

19. A process as claimed in claim 11, wherein the aqueous multi-phase composition is a formulation that contains a polymer dispersion.

20. A process as claimed in claim 11, wherein the microwave heating is carried out immediately before the aqueous multi-phase composition is transferred to containers under largely sterile conditions.

21. A process as claimed in claim 11, wherein the copolymeric polyvinyl acetate comprises a vinyl acetate/maleic acid ester.

22. A process of sterilizing a microbially-contaminated aqueous multi-phase composition that contains synthetic resin, the process including the steps of:

providing an aqueous multi-phase composition that contains a synthetic resin; and

sterilizing the aqueous multi-phase composition by microwave heating under an autogenous pressure of up to 10 bar.