US2215563A - Process for coating fabrics with rubber - Google Patents

Description

Patented Sept. 24, 1940 Stewart R.'0gilby, Staten Island, N. Y., assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey N Drawing.

Application April 7, 1939,

Serial No. 266,535

6 Claims.

This invention relates to aprocess for coating fabrics with rubber, and more particularly. for coating fabrics directly from latex.

In coating fabrics directly from latex, it is very desirable to use a heat sensitive latex composition so that on raising the temperature of the latex after spreading, as in the early stages of a drying operation, the latex will set to a gel and prevent striking through of the latex and the consequent marring of the, appearance .of the un-.'

treated surface of the fabric. In producing dyed fabrics having a rubber coating thereon, it is:-' often desirable and in some cases necessary't'o apply the rubber to the fabric before the dyeing have been so compounded as to be capable of gelling on heating are alkaline in character and leave a final rubber deposit on the fabric having an alkaline reaction. Dye baths for fabrics are often neutral or slightly acid and when a fabric coated with rubber which has an alkaline reaction is introduced into sucha dye bath, the alkaline reaction of the rubber may oftentime change the pH of the bath sufliciently to give off-colors in the final dyed fabric.

According to the present invention, fabrics may be coated with a latex compositionwhich is heat sensitive and which has an acid reaction so that on the gelling, or the gelling and drying, of such a latex composition on a fabric,-the deposit will have an acid or neutral character and hence not detrimentally affect the color of the dyed material by raising the pH, as in the case of a rubber deposit having an alkaline reaction.

I have found that a latex composition stabilized by the addition to the latex of a condensation product of a straight chain aliphatic alcohol-having at least six carbon atoms with a polyglycol compound containing at least four ethenoxy groups may be made heat sensitive by adjusting its pH to below 7. The commercial name of one of such commercial products is Emulphor-O, believed to be the condensation product of tetraethylene glycol with oleyl alcohol. It has been found that up to 5% of Emulphor-O, for example, permits a latex composition of over 30% solids content to be acidified as faras a pH of 1, and yet the Emulphor-O will lose its power to protect the latex at elevated temperatures and the latex composition will gel on heating.

The present invention may be utilized in the manufacture of various types of fabrics, some or all of whose threads or yarns are to be dyed 55 after coating with the latex composition. In

operation. Commonly, latex compositions which these cases, there is no residual alkalinity in the latex gel, or the dried rubber deposit to produce off-colors in the dyeing operation. The present invention may also ,be applied to the coating of fabrics where the fabrics are not to be dyed after coating, but where it is desired that the spread latex or the final rubber coating'have an acid or neutral reaction. If the pH of the latex, according to the present invention, is lowered below i 7 by the addition of a volatile acid, then the 10 .latex after gelling will retain an acid reaction,

but on drying the rubber deposit will be neutral.

The present invention is of particular advan- :-tage in the manufacture of pile fabrics where the pile is looped around threads in a woven textile backing and the piles are anchored to the backing by means of a rubber coating or deposit. Such pile fabrics are commonly'woven on the socalled double plush principle, where two textile backings or ground fabrics are woven with pile warps looped around weft threads in each backing and where the piles are cut intermediate the two backings to produce two pile fabrics. In upholstery fabrics of suchconstruction, the textile backing is usually woven of cotton yarns and I these, if desired, may be predyed before weaving. The pile warps are commonly animal hair and these are generally dyed after the woven and split fabrics have been treated with latex according to the present invention. In carrying out the present invention with reference to such pile fabrics, the heat sensitive latex having a pH below 7 and capable of gelling at an elevated temperature, is spread onto the back of the pile fabric as by means of a spreader knife or by spraying or in any desired manner. Only suflicient latex need be applied to satisfactorily anchor the piles to the ground fabric after drying of the rubber film. The latex may be scraped onto the back of the pile fabric in such a manner that the tips of the pile bights will project from the final rubber coating, as in the present practice of making this type of upholstery fabrics. After spreading the latex compound, the deposit is heated to a temperature sufiicient to gel the latex 5 whereby striking-through of the latex on further treatment is prevented. In that the latex will not strike through after gelling, the gelled latex need not be dried before subsequent aqueous treatments. It is preferred, however, todry the fabric before dyeing and finishing, and in such case the fabric need only be passed into a drier after being spread with latex and the gelling will take place in the first stages of the drying operation where, as is generally the case, the tem- I may dye both the piles and the ground fabric.'

The following formula is illustrative of a latex composition which may be used for anchoring mohair piles to a cotton ground fabric in a pile fabric woven on the double plush principle:

Parts by weight Rubber 100 Latex Water 62 aqueous solution of Emulphor-O 12 15% aqueous solution of acetic acid 25 The above latex compound has a pH of 4.4 and a dried rubber film deposited from it has a neutral reaction due to the volatilization of the acetic acid on drying. This latex is fluid at ordinary room temperatures and will gel at temperatures of 85 C. or above. It is thus only necessary to spread the latex compound on the back of the pile fabric at temperatures below the gelling temperature, and after spreading to pass the spread fabric through a conventional drier having a temperature greater than 85 C. at its entrance so that the latex compound will gel in the first stages of the drying operation, and the further heating of the gel to dry the same will evaporate water from the gel without the rub ber particles which are no longer mobile striking through and marring the face of the fabric. Various other compounds may be used, and the latex may be unvulcanized or vulcanized as desired.

In view of the many changes and modifications that may be made without departing from the principles underlying the invention, reference should be made to the appended claims for an understanding of the scope of the invention.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. The process of coating. a fabric with rubber which comprises applying to a fabric a fluid latex composition having a pH below '7 and containing a condensation product of a straight chain aliphatic alcohol having at least six carcapable of gelling at elevated temperature, heating the applied latex composition to a temperature sufficient to gel the same, and drying.

gelling at elevated temperature, heating the applied latex composition to a temperature sufficient to gel the same, and drying.

3. The process of producing a dyed fabric with a rubber coating thereon which comprises applying to an undyed fabric a fluid latex composition having a pH below 7. and containing a condensation product of a straight chain aliphatic alcohol having at least six carbon atoms with a polyglycol compound containing at least four ethenoxy. groups, said latex composition being fluid at room temperature and capable of gelling at elevated temperature, heating the applied latex composition to a temperature sufficient to gel the same, and dyeing the coated fabric.

4. The process of producing a dyed fabric with a rubber coating thereon which comprises applying to an undyed fabric a fluid latex composition having a pH below 7 and containing Emulphor-O, said latex composition being fluid at room temperature and capable of gelling at elevated temperature, heating the applied latex composition to a temperature suflicient to gel the same, and dyeing the coated fabric.

5. The process of making pile fabric which comprises weaving a textile backing with undyed pile warps looped therein, applying to the backing and pile loops a fluid latex composition having a pH below 7 and containing a condensation product of a straight chain aliphatic alcohol having at least six carbon atoms with a'polyglycol compound containing at least four ethenoxy groups, said latex composition being fluid at room temperature and capable of gelling at elevated temperature, heating the applied latex composition to a temperature sufllcient to gel the same, and dyeing the coated fabric.

6. The process of making pile fabric which comprises weaving a textile backing with undyed pile warps looped therein, applying to the backing and pile loops a fluid latex composition having a pH below 7 and containing Emulphor- 0, said latex composition being fluid at room temperature and capable of gelling at elevated temperature, heating the applied latex composition to a temperature suflicient to gel the same, and dyeing the coated fabric.

STEWART R. OGILBY.