GB2238793A

GB2238793A - Cleaning process

Info

Publication number: GB2238793A
Application number: GB9023443A
Authority: GB
Inventors: Kaspar D Hasenclever
Original assignee: Chemische Fabrik Kreussler and Co GmbH
Current assignee: Chemische Fabrik Kreussler and Co GmbH
Priority date: 1989-12-09
Filing date: 1990-10-29
Publication date: 1991-06-12
Anticipated expiration: 2010-10-29
Also published as: GB2238793B; GB9023443D0; DE3940804A1

Abstract

Octa- and/or deca-methyl cyclosiloxane and/or at least one C12-14 isoparaffin and/or a dearomatized white spirit with a boiling range of 180 to 210 DEG C is/are used as a solvent for impregnating and/or finishing agents for chemical cleaning in order to obtain non-toxic solutions, which on drying leave no residues on the cleaned textile or fabrics and do not dissolve as an impurity in perchloroethylene.

Description

9 . 9 1 CLEANING PROCESS 3 a -7 -3 3 This invention relates to the

cleaning of various materials. The water- repe llen cy of waterproof and sports clothing, as well as feel- improving finishes, is usually destroyed in standard dry-cleaning processes and must therefore be restored by an appropriate aftertreatment. Impregnating and finishing agents for use in such aftertreatment include resins, synthetic resins, fluoro-polymers, paraffins and waxes, as well as mixtures of such components, all of which are solid substances and consequently must be dissolved in a suitable solvent, e.g. a perfluoroacrylate prior to application.

As is known, perchloroethylene has been used hitherto as the solvent for such impregnating and finishing agents and is also used as a solvent in chemical cleaning. However, perchloroethylene suffers from the disadvantage of endangering water supplies (water hazard class 3) and it may have harmful health effects on workers. As perchloroethylene is suspected of being carcinogenic, it is essential to avoid open handling of solutions containing it.

If solvents other than perchloroethylene are used for impregnating or finishing agents, it is necessary that they evaporate rapidly, so that after drying no solvent residues adhere to the cleaned textiles. In addition, the boiling point of the solvent must be so high that on distilling the perchloroethylene used as cleaning solvent, they remain in the distillation residue to avoic contamination of the perchloroethylene, which would become enriched with undesirable materials. As a result of these fundamentally contradictory objectives, as yet no satisfactory replacement solvent has been found for perchloroethylene for the indicated purpose.

The present invention is based on the discovery that a suitable solvent for impregnating and/or finishing agents for chemical cleaning, which is non-toxic, rapidly evaporates and has an adequately high boiling point, is octa- and/or deca-methyl cyclosiloxane and at least one C12-14 isoparaffin and/or a dearomatized white spirit with a boiling range of 180 to 2100C, and in accordance with the'invention such a solvent is used for that purpose.

The present invention also provides a method of cleaning in which an aftertreatment is carried out with an impregnating and/or finishing 2 agent dissolved in octa- andlor deca-methyl cyclosiloxane and/or at least one C12-14 isoparaffin and/or a dearomatized white spirit with a boiling range of 180 to 2100C.

These solvents or solvent mixtures make it possible to dissolve the requisite active substances in an adequate concentration; they evaporate sufficiently rapidly to ensure that no solvent residues remain on the cleaned textiles after drying; and they have adequately high boiling points to remain in the distillation residue during perchloroethylene distillation. In addition, they are sufficiently thermally stable to ensure that they do not decompose in the distillation residue of the cleaning machines. They are also nontoxic. They dissolve the active substances over a wide temperature range in a stable manner, so that the solutions have an adequately low viscosity and can be used without harming the environment, without inflammability and explosion risks, and without endangering the health of workers.

Octamethyl cyclotetrasiloxane and decamethyl cyclopentasiloxane have proved to be suitable cyclosiloxanes. Octamethyl cyclotetrasiloxane is particularly advantageous: its boiling point is above 1720C, its flash point is 550C, it is neither toxic nor harmful to waste waters, its heat of evaporation is less than 10%, based on water, and it is both odourless and colourless.

Equally suitable are dearomatized white spirits with a boiling range of 180 to 2100C and isoparaffins with 12 to 14 carbon atoms with an evaporation number of approximately 200. Both product types give an adequate evaporation rate and an adequately high boiling range.

Dearomatized white spirits are refined petroleums that are free from benzene and naphthalene derivatives and essentially comprise paraffins.

Particularly advantageous for the indicated purpose are mixtures comprising one or more of the indicated cyclosiloxanes and at least one of the indicated isoparaffins and/or dearomatized white spirits. For such mixtures the weight ratio is desirably 5 to 40 and preferably 10 to 30% by weight cyclosiloxane, balance isoparaff in andlor dearomatized white spirit.

lmpregnating or finishing solutions prepared from such.solvents or solvent mixtures, and that may comprise perfluoroacrylates, can have active substance contents of 5 to 50 by weight. They are easily and c.i i 3 safely handleable liquids, and can be used in preparation and processing without endangering the health of workers. Apart from pure solvents, examples of advantageous solvent mixtures suitable for use in accordance with the present invention are given below:

EXAMPLES (1) 20% by weight octamethyl cyclotetrasiloxane 80% by weight of a mixture of C12-14 isoparaffins (2) 20% by weight octamethyl cyclotetrasiloxane 80% by weight dearomatized white spirit (boiling range 180 to 210OC) (3) 20% by weight octamethyl cyclotetrasiloxane 40% by weight C12-14 isoparaffins 40% by weight dearomatized white spirit (boiling range 180 to 210OC) (4) 15% by weight octamethyl cyclotetrasiloxane 15% by weight decamethyl cyclopentasiloxane 30% by weight C12-14 isoparaffins 40% by weight dearomatized white spirit (boiling range 180 to 210OC) (5) 15% by weignt decamethyl cyclopentasiloxane 35% by weight dearomatized white spirit (boiling range 180 to 210OC) 50% by weight C12-14 isoparaffins 1 4

Claims

1. The use of octa- and/or deca-methyl cyclosiloxane and/or at least one C12-14 isoparaffin and/or a dearomatized white spirit with a boiling range of 180 to 2100C as a solvent for impregnating and/or finishing agents for chemical cleaning.

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2. The use of a mixture of cyclosiloxane with at least one isoparaffin andior dearomatized white spirit as claimed in Claim 1.

3. The use of a mixture of 5 to 40 by weight cyclosiloxane with the balance constituted by isoparaffin and/or dearomatized white spirit as claimed in Claim 2.

4.

The use as claimed in Claim 3, in which the mixture contains 10 to 30% by weight cyclosiloxane with the balance constituted by isoparaffin and/or dearomatized white spirit.

5. The use as claimed in Claim 1 in which the solvent is SUbStantially as hereinbefore described in any one of Examples (1) to (5).

6. A method of dry cleaning in which an aftertreatment is carried out with an impregnating and/or finishing agent dissolved in octa- and/or decamethyl cyclosiloxane and/or at least one C12-14 isoparaffin and/or a dearomatized white spirit with a boiling range of 180 to 2100C.

7. A method as claimed in Claim 6 in which the said solvent is a mixture of cyclosiloxane with at least one isoparaffin and/or dearomatized white spirit.

8. A method as claimed in Claim 7 in which the said solvent contains 5 to 40 by weight cyclosiloxane with the balance constituted by isoparaffin and/or dearomatized white spirit.

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9. A method as claimed in Claim 8 in which the said solvent contains 10 to 30% by weight cyclosiloxane with the balance constituted by isoparaffin and/or dearomatized white spirit.

10. A method as claimed in Claim 6 in which the said solvent is substantially as hereinbefore described in any one of Examples (1) to (5).

p ndonWC3R4TP. Further copies may be obtained frorn Published 1991 atlle Patent Office, State House. 66171 High Holborn. L4) Sales Branch. Unit 6. Nine Mile Point Cwrnfelinfach, Cross Keys. Newport. N 1 7HZ. Printed by multiplex techniques lid, St Mary CnW. Kmt-