GB2085491A

GB2085491A - Waterproofing Products and Process

Info

Publication number: GB2085491A
Application number: GB8131342A
Authority: GB
Original assignee: Saxby W E (Nottingham) Ltd; Caligen Foam Ltd
Current assignee: Saxby W E (Nottingham) Ltd; Caligen Foam Ltd
Priority date: 1980-10-16
Filing date: 1981-10-14
Publication date: 1982-04-28
Also published as: GB2085491B

Abstract

A method of treating fabrics to render them water-resistant comprises freely commingling the fabrics while in a damp and heated condition with a waterproofing product comprising a flexible substrate substantially uniformly impregnated with a water resistant agent, whereby to transfer the water resistant agent to the fabrics. The substrate preferably comprises an open-celled foam structure such as polyurethane foam.

Description

SPECIFICATION Waterproofing Products and Process This invention relates to the treatment of fabrics to render them water-resistant.

Many garments used for sports and leisure purposes would benefit from being waterresistant or showerproof. However the waterproofing of garments has hitherto been confined to professional laundries or similar establishments and is relatively expensive.

Moreover the purchase of clothing of waterproof construction for occasional use by golfers, campers, hikers or in connection with spectator sports or the like is normally not justified for cost reasons. There is therefore a need for some means of rendering conventional garments temporarily water-resistant and it is an object of the present invention to provide a method and means whereby this may be achieved.

The invention provides a method of treating fabrics to render them water-resistant comprising freely commingling the fabrics while in a damp and heated condition with a waterproofing product comprising a flexible substrate substantially uniformly impregnated with a water resistant agent, whereby to transfer the water resistant agent to the fabrics.

Advantageously the method may be carried out by tumbling the fabrics and the waterproofing product in a laundry drier at a temperature of between 500 and 700C (1200 to 1600F).

Preferably the substrate comprises an opencelled foam structure which may be of polyurethane foam and preferably has a thickness of 1.5 to 2.0 millimetres. The water-resistant agent is preferably applied to the substrate in a heated liquid state and subsequently solidified by cooling.

The water resistant agent preferably comprises a wax or blend of waxes and may include additional water resistant compositions selected from certain metal compounds, silicone compounds and fluorocarbon compounds.

Thus the invention also provides a product for use in treating fabrics to render them water resistant comprising a sheet of flexible substrate substantially uniformly impregnated with a water resistant agent comprising a wax or blend of waxes optionally including additional water resistant compositions based on certain metal compounds, silicone compounds or fluorocarbon compounds. The flexible substrate preferably comprises an open-celled foam structure such as polyurethane foam.

Impregnation of the substrate with the water resistant agent is preferred to coating of the substrate since impregnation ensures a uniform release of the agent over a period of time. When the product is used in a laundry drier this ensures that that the articles with which the waterproofing product is commingled are uniformly treated with the water resistant composition and avoids excessive deposition of the composition on those articles which first come into contact with the substrate as could occur where the substrate was coated rather than impregnated.

In order to ensure substantially uniform dispersion of the water resistant agent through the cellular substrate it is preferred that the agent should be applied to the substrate while the latter is compressed, the substrate being subsequently allowed to expand thereby creating a partial vacuum within the cell structure which draws the agent into and disperses it through the structure.

The extent to which the substrate is compressed may be varied dependent on the nature and thickness of the foam, the speed of travel and the nature of the water resistant agent employed, but the degree of compression must be such that on subsequent expansion the water resistant agent is drawn into the foam structure so that it is dispersed throughout its cross-section. The foam structure in effect acts as a reservoir for the agent which is subsequently released in a uniformly controlled manner when subjected to heat in the fabric drier.

Where the substrate comprises an open-celled foam structure, any such structure may be used but polyurethane foams and particularly polyester-urethane foams are preferred due, particularly in the latter case, to their uniform foam structure which further enhances the uniform release of the water resistant agent. The thickness and cell size of the foam may be varied but for commercial reasons the foam thickness is preferably in the region of 1.5 to 2.0 millimetres.

The uptake of water resistant agent is preferably in the region of 2:1 to 10:1 based on foam weight although this may be varied dependent on the agent utilised and the rate of release of the agent during drying.

The wax base may be paraffinic wax (of any melting point grade) including microcrystalline wax, slack wax, ceresine and ozokerite, or may be a blend of these waxes.

The paraffin wax of the base may further be blended with other waxes, for example polythene, polypropylene, carnauba, montan, or the various natural waxes such as tallow and spermacetti.

The wax base may consist of 40100% of the total composition by weight and may be mixed with additional water resistant compositions based on: (1) certain metal compounds (2) silicone compounds, or (3) fluorocarbon compounds the additional water resistant compositions being from 600% of the total weight of the product.

The additional water resistant composition may be: (1) a metal compound derived from (a) aluminium: (1) fatty alcohol condensates with aluminium, using alcohols containing from 6 to 18 carbon atoms in their chain, the ratio of aluminium to alcohol being from 1 mole equivalent aluminium: 1.1 to 3 mole equivalents of alcohol (2) fatty acid condensates with aluminium using fatty acids containing from 6 to 22 carbon atoms in their chain, the ratio of aluminium to acid being from 1 mole equivalent of aluminium: 1.1 to 3 mole equivalents of acid. The preferred compounds are aluminium tristearate, poly oxo aluminium stearate and poly-oxo aluminium octoate.

(b) titanates:- (1) alkyl titanates based on alcohols having from 3 to 18 carbon atoms in the chain and glycols, especially the 1.3 diols such as 2 ethyl 1.3 hexane diol and including those that cure under moist conditions.

(2) the longer chain fatty acid and di-acid condensates (6 to 22 carbon atoms) with titanium.

(3) the polymeric titanates with pendant alkyl groups having 3 to 22 carbon atoms in the chain.

(c) zirconates:- (1) alkyl zirconatesbased on alcohols having from 3 to 18 carbon atoms in the chain and gycols, especially the 1.3 diols such as 2 ethyl 1.3 hexane diol and including those that cure under moist conditions.

(2) the longer chain fatty acid and di-acid condensates (6 to 22 carbon atoms) with zirconium (3) the polymeric zirconates with pendant alkyl groups having 3 to 22 carbon atoms in the chain.

(2) Silicone compounds such as poly di-methyl siloxanes and silicone resins either alone or mixed with titanate or zirconate cross-linking catalysts.

(3) Fluorocarbon compounds such as C3 to C12 alcohols or acids reacted with appropriate chemicals to form esters, amides or polymers.

Also the fluorocarbon acid and alcohol complexes with aluminium, titanate and zirconate metals.

The temperature at which the water resistant agent is applied to the substrate will vary in accordance with the molecular weight of the agent but will generally be between 370 and 7000 and preferably around 600 C. The speed of travel of the substrate during application of the agent may be varied up to about 50 metres a minute, but for practical commercial purposes a speed of travel of around 35 metres per minute is preferred. When the agent is applied by means of rollers which also serve to transport the substrate the quantity of agent applied in independent of the speed of travel but commercial considerations require a relatively high speed consistent with maintenance of the integrity of the substrate.

Cooling of the heated substrate must be effected to a temperature below the melting point of the water resistant agent. The appropriate temperature will vary dependent on the composition of the water resistant agent, but it is preferred that cooling should be applied to an extent sufficient to ensure solidification of the agent throughout the cross-section of the foam or other substrate. In general a temperature of below 370C and normally around 250C would be appropriate.

In use of the product it is inserted with clothing or other fabrics to be dried into a drier so as to be tumbled and commingled with the articles during drying. Conventionally such driers operate at a temperature in the region of 50--700C which is above the melting point of the water resistant agent. The agent therefore melts and is transferred to the fabrics by contact between the product and the fabrics resulting from the motion of the drier.

When applied to articles of clothing the articles are rendered shower-repellent and may therefore be used for sports or leisure purposes as a protection against rain. When the garments are again washed the water resistant agent is washed out but the garments may be re-waterproofed by inserting a further product in the drier during the drying cycle.

It should be noted that it is important that the fabrics or articles of clothing should be free of soap or detergent as this will substantially reduce the effectiveness of the water-proofing action. It is not therefore possible to impart water resistance to the garments during a washing cycle but satisfactory results can be attained during the drying cycle providing the intermediate rinses have been sufficient to remove all residual soap or detergent from the garments after the washing cycle.

The following example illustrates, by way of example only, a practical application of the invention; Example A web of polyester-urethane foam 2 mm thick having a weight of 56 grammes per square metre and a density of 28 Kilogrammes per cubic metre and having 18 to 22 cells per linear centimetre was passed at a speed of 35 metres per minute through nip rolls serving to compress the foam so as to expel air therefrom. The nip rolls also served as applicators to apply to the foam a waterproofing agent comprising 92.5% of a paraffinic wax base and 7.5% of a water-resistant composition based on tetra nonyl titanate. The composition was applied to the foam at a temperature of 6000 and a rate of application of 200 grammes per square metre. After passing through the nip rolls the foam was allowed to expand freely to its normal dimensions and was then cooled to 250C by forced air draught at ambient temperatures. The foam was then cut into sections of 25x25 cm2for use as a drier added waterproofing product. This product was tested in a conventional household drier containing garments having a dry weight of 1 kilo.

The damp garments were dried in 60 minutes under normal drying conditions of about 1200 to 1400F with the inclusion of two units 25 cmx25 cm of foam impregnated with the water resistant agent. After removal from the drier the articles of clothing were found to have a substantial degree of water-resistance sufficient to repel rain showers although it must be appreciated that articles treated in accordance with the invention are not rendered totally water repellent.

While directed principally to products for use in conventional household driers, the invention may also be applied to commercial drying establishments and particularly to user operated driers and dry cleaning machines. In the case of user operated driers such as are available at launderettes and like establishments, the products described above may be used in the same manner as in domestic clothes driers. In the case of dry cleaning machines, conventional machines effect cleaning and hydroing of the goods, following which the solvent is removed by heating as in a tumble drier. A waterproofing product according to the invention may accordingly be introduced at this stage and would result in transfer of the water resistant composition to the articles being dried.For this purpose the water resistant agent would require to be soluble in the solvents used in the dry cleaning process and suitable solvents include chlorinated solvents such as perchloroethylene and trichloroethylene, paraffinic solvents such as white spirit, and fluorocarbon solvents such as Arklone 11 3 solvent and 11 solvent (Arklone, 11 3 and 11 are Trade Marks).

The invention therefore provides a waterproofing product which may be readily and inexpensively produced in commercial quantities and which can be used by the housewife in a domestic clothes drier to provide even and uniform release of water resistant compound during drying of fabrics or articles of clothing.

Various modifications may be made without departing from the invention, and perfume components may be incorporated to imparh a fresh perfumed odour to the treated fabrics or articles if desired.

Claims

1. A method of treating fabrics to render them water-resistant comprising freely commingling the fabrics while in a damp and heated condition with a waterproofing product comprising a flexible substrate substantially uniformly impregnated with a water resistant agent, whereby to transfer the water resistant agent to the fabrics.

2. A method according to claim 1 comprising tumbling the fabrics and the waterproofing product in a laundry drier at a temperature of between 500 and 70cm.

3. A method according to claim 1 or 2 wherein said substrate comprises an opencelled foam structure.

4. A method according to claim 3 wherein said foam structure is polyurethane foam.

5. A method according to claim 4 wherein said foam structure is polyester-urethane foam.

6. A method according to any preceding claim wherein said substrate has a thickness of 1.52.0m/m.

7. A method according to any preceding claim wherein said water-resistant agent comprises a wax or a blend of waxes.

8. A method according to claim 7 wherein said water-resistant agent includes additional water resistant compositions selected from metal compounds, silicone compounds and fluorocarbon compounds.

9. A method of treating fabrics to render then water-resistant substantially as hereinbefore described.

10. A product for use in treating fabrics to render them water resistant comprising a sheet of a flexible substrate substantially uniformly impregnated with a water resistant agent.

11. A product according to claim 10 wherein said substrate comprises an open-celled foam structure.

12. A product according to claim 11 wherein said foam structure comprises polyurethane foam.

13. A product according to claim 12 wherein said foam structure is a polyester urethane foam.

14. A product according to any of claims 10 to 13 wherein said substrate has a thickness of

1.5 to 2.0m/m.

1 5. A product according to any of claims 10 to 14 wherein the ratio of water-resistant agent to foam comprises 2:1 to 10:1 by weight.

1 6. A product according to any of claims 10 to 15 wherein said water-resistant agent comprises a wax.

17. A product according to claim 16 wherein said wax is a paraffinic wax including microcrystalline wax, slack wax ceresine and ozokerite.

18. A product according to claim 16 or 17 blended with further waxes selected from polythene, polypropylene, carnauba, montan, tallow and spermacetti.

19. A product according to any of claims 16 to 18 incorporating up to 60% by weight of an additional water resistant composition selected from metal compounds, silicone compounds and fluorocarbon compounds.

20. A product according to claim 19 wherein said additional water-resistant composition is an aluminium compound selected from fatty alcohol condensates with aluminium and fatty acid condensates with aluminium.

21. A product according to claim 19 wherein said additional water-resistant composition is a titanium compound selected from alkyl titanates, long chain (C6C22) fatty acid and di-acid condensates with titanium, and polymeric titanates with pendant alkyl groups having 3 to 22 carbon atoms in the chain.

22. A product according to claim 19 wherein said additional water-resistant composition comprises a zirconium compound selected from alkyl zirconates long chain (C6C22) fatty acid and di-acid condensates with zirconium and polymeric zirconates with pendant alkyl groups having 3 to 22 carbon atoms in the chain.

23. A product according to claim 19 wherein said additional water-resistant composition comprises a silicone compound selected from poly di-methyl siloxanes and silicone resins either alone or mixed with titanate or zirconate crosslinking catalysts.

24. A product according to claim 19 wherein said additional water-resistant composition comprises a fluorocarbon compound selected from esters, amides or polymers of C3C12 alcohols or acids, and fluorocarbon acid and alcohol complexes with aluminium, titanate and zirconate metals.

25. A product according to any of claims 10 to 24 wherein said water-resistant agent is soluble in dry cleaning fluids.

26. A product according to claim 25 wherein said water-resistant agent is soluble in chlorinated solvents, paraffinic solvents and fluorocarbon solvents.

27. A product for use in treating fabrics to render them water-resistant substantially in accordance with the foregoing example.

28. A method of producing a product according to any of claims 10 to 27 comprising impregnating a continuously moving length of said substrate with said water-resistant agent and subsequently cutting the impregnated substrate into sections of appropriate size.

29. A method according to claim 28 wherein said water-resistant agent is applied to said substrate in a heated liquid state while the substrate is compressed, the substrate being subsequently allowed to expand, whereby to draw the agent into and disperse it through the substrate and the water-resistant agent then being solidified by cooling.

30. A method according to claim 29 wherein the water-resistant agent is applied to the substrate at a temperature of 37070CC.

31. A method according to claim 30 wherein the impregnated substrate is cooled to below 370C to solidify the water-resistant agent.

32. A method according to any of claims 28 to 31 wherein the speed of travel of said substrate during impregnation is not greater than 50 metres/minute.

33. A method for producing a product for use in treating fabrics to render them water-resistant substantially in accordance with the foregoing example.