CA1107160A - Sweat resistant gas protective material - Google Patents
Sweat resistant gas protective materialInfo
- Publication number
- CA1107160A CA1107160A CA262,992A CA262992A CA1107160A CA 1107160 A CA1107160 A CA 1107160A CA 262992 A CA262992 A CA 262992A CA 1107160 A CA1107160 A CA 1107160A
- Authority
- CA
- Canada
- Prior art keywords
- activated carbon
- adsorbent
- foam
- repellent substance
- laminated fabric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A method is described of minimizing the adverse effects of sweat and sebum on a flexible porous material which is permeable to air and water vapor but resistant to passage therethrough of noxious chemicals in liquid or vapor form.
The flexible porous material is, for instance, a laminated fabric material comprising an air- and water vapor-permeable open cell solid resin foam bonded to an air and water vapor-permeable fabric backing, within which foam is dispersed and bonded a particulate adsorbent material for the noxious chemicals, eg. activated carbon. The aforesaid flexible porous material is protected from deterioration by exposure to sweat and sebum by treating it with a liquid organic polymeric water- and oil-repellent substance, preferably a fluorochemical, which is compatible with any substances used to disperse or bind the adsorbent material in the flexible porous material, and which is of a type which does not reduce to any significant extent the adsorptive capacity of the ad-sorbent, eg. activated carbon.
A method is described of minimizing the adverse effects of sweat and sebum on a flexible porous material which is permeable to air and water vapor but resistant to passage therethrough of noxious chemicals in liquid or vapor form.
The flexible porous material is, for instance, a laminated fabric material comprising an air- and water vapor-permeable open cell solid resin foam bonded to an air and water vapor-permeable fabric backing, within which foam is dispersed and bonded a particulate adsorbent material for the noxious chemicals, eg. activated carbon. The aforesaid flexible porous material is protected from deterioration by exposure to sweat and sebum by treating it with a liquid organic polymeric water- and oil-repellent substance, preferably a fluorochemical, which is compatible with any substances used to disperse or bind the adsorbent material in the flexible porous material, and which is of a type which does not reduce to any significant extent the adsorptive capacity of the ad-sorbent, eg. activated carbon.
Description
SWEAT RESISTANT GAS PROTECTIVE MATERIAL
This invention relates generally to materials which, while relatively permeable to air and water vapor, are resistant to the passage of noxious undesirable chemicals in the form of liquids and condensible vapors and gases. More particularly, the invention relates to the protection of such materials, and in particular gas protective clothing, from deterioration by exposure to sweat and sebum.
For protection against noxious chemicals such.as the gases and smokes employed in chemical warfare, and also against dangerous chemicals such as industrial poisons and pesticides which are generally in the form of sprays or mists, it is customary to use protective equipment and in particular protect-ive clothing which incorporates a gas and vapor adsorbent material.
Garments have been p.rov~ded which are made from fabric which is sufficiently permeable to air and water vapour to permit their use by humans with some degree of comfort for a reasonable period and at the same time provide protection from the undesirable ~ effects o~ noxious chemicals such as chemical warfare agents.
Such garments are described, for example, in British Patent 575,379 issued 15 February 1946 to Kingan, and U.S, Patent.
; 2,984,584 issued 16 May, 1.961 to Glarum. In these patents wo~en and non-woven fabrics are impregnated with an aclsorbent such ~as ~inely divided carbon which is held in place on the textile fibres by a polymeric binder.
The prerequisites of an ideal gas-proofed material, in particular for use as wearin~ apparel, are as follows: The material should be such that it adsorbs a relatively large amount of noxious chemicals such as chemical warfare agents ~:
while permitting oxygen or air to pass through; the supporti.ng mate~ial for the adsorbent should be substantially po.rous in :~ .
order to permlt perspiration or other liquîds to evaporate from X
- - . . ~
: ~ . . ~ . . :
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the wearer's body; the material comprising the suppoxt should substantially retain its flexibility afker being co~bined with the gas adsorbent; and the gas adsorb~nt showld be substantially permanently bound to the supporting material in order to prevent the adsorbent from becoming dislodged from -the support by rain, laundering or rough usage or by the softening effect of moisture and perspiration. Finally the gas-proofed material should be capable of reuse after decontamination.
In Canadian Patent 878,560 of J.A. Hart, issued August 1017, 1971, an air and water vapour permeable open cell solid resin foam resistant to passa~e therethrough of noxious chemicals in liquid or vapor form, in which there is dispersed a particulate adsorbent material for said noxious chemicals, and laminated fabric materials, eg. in the form of protecti~e clothing, incorporating said foam, are describedO The particulate adsorbent material is bonded in said Eoam by an organic binder which is substantially free from sukstances which would substantially deactivate the adsorbent~ The laminated fabric materials described in this patent include an air and water vapor-permeable ~abric backin~ to which the aforesaid foam is bonded.
The adsorbent material in particulate form may be any solid part.iculate material capable of adsorbing the noxious chemiaals. Such adsorbent materials are well know ~ se in the art and include, for example, silica gel and active clays o~ the attapulgite and bentonite classes, e.gu fullerls earth.
A particularly preferred adsorbent material is activated carbon.
As pointed out in the aforesaid Canadian Patent ; 878,560, flexible Eoams do nQt ~ se possess high mechanical strength so that, for use in garments, it is the customary practice to bond, ie. laminate, the foam, in known manner, to a fabric, such as a knitted or woven textile material, for example, nylon tricot, cotton sheeting, canton flannel, poplin, ' ~ ' ~ -2-.
L6~
percale, etc. in order to provide a reinforced material. Instead of loose knit or woven fabrics, non woven fabrics such as netting or scrim may also be used to reinforce the foam. If the reinforcing fabric is also impregnated some additional resistance may be obtained in view o~ the additional adsorbent employed;
however this effect is usually minimal. The fabric is essentially for mechanical reinforcement and is bonded to the foam by known lamination techniques such as flame lamination, adhesive lami-nation, stitch bonding and quilting.
The preferred foams for use in the aforesaid laminated textile materials are flexible polyurethane foams such as those of the polyester and polyether types. However flexible foams of cellulose, polystyrene, vinyl polymers or polyesters may also be employed if desired.
The chemical warfare protective clothing adopted by the Canadian Armed Forces is based upon the activated carbon impregnated polyurethane foam and laminated textile materials in-corporating this foam, described in the aforesaid Canadian Patent 878r560 entitled "Gas Resistant Foam Material". In common with all chemical protective clothing materials in which activated carbon is the effective component, it is subject to degradation in performance due to the action of sweat and sebum. Practical trials have shown that the useful life of chemical protective clothing is limited more by the adverse effect of sweat on the gas adsorptive capacity of the activated carbon adsorbent, than by the effects of wear and tear on -the clothing. The adverse effect of sweat, often referred to as sweat-poisoning, is apparent even when the protective clothing is worn in temperate climatic conditions together with a ~as mask and auxiliary protection for 3n hands and feet, since the metabolic heat generated by modera-te activity lS not fully dissipated, but induces sweating.
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The components of sw~at which are adsorbed by activated carbon and thus degrade its ability to scavenge gases and vapours are the organic substances of which urea and salts of lactic acid form the greater part. The inorganic salts, although present in larger quantities, do not have so great an effect as the organic substances, but do contribute to the degradation of the carbon unless denied access.
The present invention seeks to reduce or eliminate the adverse effect of sweat on the gas scavenging property of activated carbon in clothing materials by use of a liquid repel-lent treatment to prevent access of sweat to the activated carbon~
It is necessary to preserve the porous structure of the clothing material so that gases and vapours may have free access to ~ :
the adsorption sites on the activated carbon or other adsorbent while restraining the movement of liquid sweat.
This can be achieved by applying as a thin film on the surfaces of the porous material, a substance for which water and other liquid has little affinity and does not wet. Such ~0 substances are commonly used for rendering various porous mater-ials such as textiles, paper and leather resistant to the penetration of li~uids.
The present invention, in its broadest method aspect, resides in a method of mi.nimi2iny the adverse e:E~ects of sweat and sebum on a f:Lexlble porous material which is permeable to air and water vapor:but is resistant to passage therethrough of - noxious chemicals in liquid or vapor form, said material con-~
tainin~ a particulate activated carbon which is an adsorbent for said noxious: chemlcals, which method comprises treating said . : 30 flexible, porous material containing said activated carbon ad-sorbent with a liquid organic polymeric water-and oil-repellant substance which is compatible with any s~stances employed to , ~7~
disperse or bind said particulate ac-tivated carhon adsorbent in said flexible porous material and being of a type which does not reduce to any significant ex~ent the adsorptive capacity of said activated carbon adsorbent.
:[n a more paxticular aspect, this invention resides in a method of minimizing the adverse effect of sweat and sebum on a laminated fabric material comprising an air- and water vapor-permeable open cell solid resin foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, the foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, which particulate activated carbon adso.rbent is bonded in said foam by an organic binder substantially free from substances which would substanti-ally deactivate said activated carbon adsorbent, and an air and water vapor-permeable fabric backing to whi.ch the ~oam is bonded.
Thi.s method comprises treating said air- and water vapor-permeable laminated materîal with a liquid organic polymeric water and oil-repellant substance which is compatible with said organic binder, and which is o~ a type which does not reduce to any sig- -nificant extent the adsorptive capacity of said activated carbon adsor~ent.
More particularly, the present invention resides in a method clS described above, but in which the repellent substance is one which contains a high proportion of pe:rfluorocarbon chains in the molecule~
In a ~urther aspect, this invention resides in a flex-ible porous material permeable to air and water vapor but resist- -an~ to passaye therethrough of noxious chemicals in liquid or vapor form, said material containing a particulate activated carbon ads~orbent for said noxious chemicals, and being further character-ized by being resistant to deactivation by sweat and sebum of said particulate activated carbon adsorbent material~ said flexible , porous material having been trea~ed with a liquid oryanic poly maric water-and-oil-repellent substance, said repellent substance being compatible with any s~stances employed to disperse or bind said particulate activated carbon adsorbent in said flex-ible porous material and being of a type which does not reduce to any significant extent the adsorptive capacity of said acti-vated carbon adsorbent.
The present invention~ in a more particular aspect, provides a method of minimizing the adverse effect of sweat and sebum on a laminated ~abric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in li.quid or vapor form, said foam being bonded to an air and water vapor-permeable fabric backing, said foam having dispersed therei.n particulate activated carbon adsorbent material for the noxiou,s chemicals, which particulate adsorbent material is bonded in said foam by an organic binder substant.ially free from substances which would substantially deactivate said adsorbent material, and an air-and water vapor-permeable fabric backing -to whi.ch the foam is bonded, which method comprises:
impregnating the adsorbent material with a first liquid organic polymeric water- and oil-~repellent substance containing a high proportion o~' per~luorocarbon chains, said repellent substance bei.ng compatible with said organic binder and being , ' of a type which does not reduce to any significant extent the adsorptive capacity of said'adsorbent, said impregna-ting OGcurring by mixing as an aqueous dispersion said activated carbon adsorbent material and said repellent substance;
applying said aqueous dispersion of activated carbon adsorbent ~0~ material and repellen~ substance to the laminated fabric ~aterial ~thereby impre~gnating the ~aasor~bent~'~materia~ within ~ -the~foam; drying the impregnated~laminated fabric~material;
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dissolving in an organic solvent a second organic polymeric water and oil-repellent substance, different from said first substance, but also containing a high proportion of perfluorocarbon chains, be.ing compatible with the organic binder, and being of a type which does not reduce to any significant extent the adsorptive capacity o the adsorbent;
and applying the organic solvent-repellent solution to the dried impregnated laminated fabric material.
This invent:ion, in a still further aspect, provides a laminated fabric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, the p~rticulate activated carbon adsorbent being bonded in said foam by an organic binder substantially free from substances which would substantially deactivate said adsorbent, and an air-and water vapor-permeable fabric backing to which the foam is bonded; said laminated fabric material being urther characterized by being resistant to deactivation of said particulate activated carbon adsorbent by sweat and sebum, said laminated fabric material having been treated by the method defined in the immediately preceding paragraph.
It is essential that the liquid repellent substance used does not seriously reduce the adsorptive capacity of the activated carbon or other adsorbent. This is an impcrtant practical limitation since most of the known liquid repellent .
substances used in treatment of fabrics, paper, leather, etc.
are adsorbeù by activated carbon and block some or all of ~
the adsorption capacity ~hich is then not available for . -adsorption of gases. ~.
A suitable repellent substance is of polymeric nature .
Sb-Q
and of molecular size such that its molecules cannot penetrate i.nto the intern~l pores of the charcoal ill which yas adsorption takes place.
It is also desirable that the repellent substance creates a surface with the lowest possible affinity for liquid sweat for the residue of organic and inorganic substances left when sweat dries, or for the oily substances of sebum which : normally accomp~ny sweatO
Of all the li~uid repellent substances known to the water-proofing art, it is chiefly those containing a high pro-portion of perfluorocarbon chains which create a surface of sufficiently low energy as to repel oils, as well as the residue rom sweat dried upon the clothing and freshly secreted liquid : sweat. Because of this property they are the preferred repel-lents or exclusion of s~eat and the oily exudations from the skin. They may be applied to the activated carbon impregnated ~abric by impregnation or coa~ing from d.ispersion in water or organic solvents as ~or example by using a padding mangle. :.
The repellents may also be mixed into the di.spersion of acti- ~ :
vated carbon used to Lmpregnate thè fabric, which in the pre-:: ferred case is a polyurethane foam bonded to a textile. They may be applied to the activated carbon imprègnated ~abric by impregnation or coating ~rom dispersion in water as or example by using a padding mangle or organic solvents. The pre~erred and most effective method is to mix one repellent as an aqueous ~;: dispersion with the activated carbon aispersion, and after impregnation with this mixture and subsequent drying, to apply a second repellent dissol~ed in an organic so.lvent by a second ~ :impregnation operation. The water repellency created by the ~3Q first~treatment~renders it impossible to wet the material ~ suf~iciently well :to~ ~mpregnate:a second time with an aqueous :
: ~ fluid. ~An organic~asol~ent With su~ficiently low surface ~ 6- --tension is required.
A variety of fluorochemical oil and water repellent compounds suitable for use in the present invention are known and are commercially available. One particular group of fluoro-chemical oil repellents are the polymers obtained by polymerizing an ethylenically unsaturated fluorochemical compoundO The ethylenic unsaturation may be either in the alcohol or the acid portion of the ester molecule. Typically, the unsaturated radical ~n the alcohol portion of the ester may be the allyl radical or the vinyl radical. Typical unsaturated acids used to prepare the ester include acrylic acid, methacrylic acid and crotonic acid~ In general, the perfluoro portion of the molecule should be in the saturated portion of the molecule. The unsatu--rated portion of the molecule is preferably not fluorinated in each instance. The acid and alcohol radicals may suitably contain from 2 to 6 carbon akoms excluding the carbonyl carbon of the acid. Examples of such monomers include vinyl perfluoro-butyrate and perfluorobutylacrylate. These monomers may be polymerized as homopolymers or as copolymers by normal emulsion polymerization techniques using free radical catalysts.
Some of these repellents are disclosed in an article by E.J~ Grajeck and W.'~. Petersen`~appearing in ~he _xt~le 'Re's'e'arch''Jo'urnalr Apr~l, 1962/ pp. 320-331, entitled "Oil and Water Fluorochemical Finishes for Cotton".
E~amples of suitable ~luoxochemical repellents are those known and sold under the trademarks "~cotchgard FC 208", '"Scotch~ard FC 210", "Scotchgard FC 232", and Scotchgard FC 319", manufactured by the 3M Company, "Zepel B" manufactured by E,I. DuPont~de Nemours and Co. and "Tinotop T-10" manufactured ~; 30 by Ciba-Geigy Ltd.~
O~ these~ materials "Scotchgard FC 208" is an aqueous nonionic emulsion containin~ approximately 28% by weight of ; ~-7- ~' .
a modified ~luorinated acrylic polymer. a substance believed to be of tne following approximate yeneral formula:
F3C (C F2)x SO2l R O ~ C CH3 R O
in which x is a value between 3 and 13 inclusive, Rl is lower alkyl, such as methyl, ethyl, propyl, and the like, having 1-6 carbon atoms; R2 is alkylene containing 1-12 carbon atoms and ~3 is H, methyl or ethyl. The product ~læepell~ is also available in emulsion form and while it is chemically difrerent from the "Scotchgard" products, it is a fluorochemical oil repellent containing fluorocarbon tails composed of CF2 groups which may end in a terminal CF3 group.
"Scotchgard FC-319" is a solution of a compound similar to "FC-208'l in an organic solvent. "Scotchgard FC-232" is a dispersion of a fluorochemical resin in a mixture of water and methyl isobutyl ketone. "~epel B" is an a~ueous cationic dispersion o~ a fluorochemical resin and is a product of E~Io Dupont de Nemours~ and Company. The exact compositions of these products are not known to this applicant but they ~ fall~wlthin the;alasses Oe compaunds disclosed in the following .
pa~ent specifications:
British Patent 971,732 E.I. Dupont de Nemours & Co~
Canadian Patent 942,900 E.K. Kleiner (Ci~a-Ceigy Co.) Canadian Patent 697,656 R~W~ Fasic]c et al (Dupont) .. .
F~ench Patent ~ 1,568,181 H. Stockman (National Staxch ~ ~ ~ & Chemical Co.) U.S. Patent 2,~03,615 ~.H. Ahlbrecht et al ~3M Co.
U.S. Patent 2,826,564 F.A. Bovey et al ~3M CoO~
.
30~~U.S. Patent~ 2,642,416 ; ~ Ah1brecht et al ~3M Co.) UOS~ Patent 2,839/513 ~7H. A7nlbrecht et al C3M Co.~
U.S. Patent 2,841,573 ~ A~H. ~hlbrecht et al (3M Co.) ; ~U.S. Patent 3,~484 j281 RoAo Guenther et al (3M Co.
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U.S. Patent 3,462,296 S. Raynolds et al (Dupont) U.S. Patent 3,636,085 E.K. Kleiner (Ciba-Geigy) U.S. Patent 3,594,353 E. Domba (Nalco Chemical Co~) French Patent 1,562,070 P. Sherman (3M Co.~
German Patent 1,419,505 E. Langerak (Dupont) U.S. Patent 3r256,230 R.E. Johnson et al (Dupont) For application of fluorochemicals from organic solvents the choice of solvent is limited by the solubility characteristics of the fluorochemical. In general, suitable ~luorochemical polymers are soluble in chlorinated or fluorinated hydrocarbons or in mixtures with other solvents such as esters, ketones and aromatic hydrocarbons. . :
Although the best results wlll be obtained by using .
fluorochemical repellents, a lesser degree of resistance to sweat poisoning could be obtained with other repellents. One example of a suitable repellent in wh.ich the repellent :Eunction is due to hydrocarbon side groups instead of perfluorocarbon side groups is the polymer of n-octyl methacrylate or of 2 ethylhexyl methacrylate. Such polymers can be incorporated wlth~an aqueous dispersion of activated carbon when prepared as~an:~aqueous emu1s;~on, or~in:solution wi:th a dispersion of ac-tivated:c~r~Qn ln an organ~c sol~ent. They may also be : applied in solution to a .~abric pre~iously impregnated with activated carbon. Siliconq resins may also be employed in some instances~ The essential requi.r.ements are that the substance used creates ~a~swea~t repellent surfac:e and that it does not cause~.substantial deactivation of the activated carbon.
To make the process work success~ully the repellent must be~an e~eati~e o~e, and:it must be~applied (either ~
. .
~30 ~ ~ogether;with the.activa~ed~carbon; or as a second step) in sufficient~yuantity~ to;~be ef~ective~ln ~reating a~surface whi:~h;~sw~at~does~ot;~:wet.~: The;~repellent substance must also ~ _ 9 _ , ,. - . , - ., , , ~.
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be compatible with other substances employed for the purposes of dispersing or binding the activated carbon. Thus if an anionic latex of a binder resin is used a cationic dispersion of repellent would not be compatible, but an anionic or non-ionic dispersion ~could be used.
The present invention will now be further described, with reference to tests which have been conducted. These tests show that the method of the present invention is effective in reducing the adverse effects of sweat and sebum on the adsorp-tivit~ of adsorbent materials contalned in laminated textilematerials as previously described.
Sweat was collected from men exercising in garments impervious to the passage of gases and vapors by centrifuging sweat-soaked cotton underwear. It was applied to the chemical barrier material in a tray, worked into the ~abric by means of a roller squeegee, and then allowed to evaporate in situ. This proceclure was repeated as man~ as twenty times until the weight of sweat solids accumulated amounted to at least the weight of the activated charcoal present~ The adsorptive capacity of the material was measured by the amount of carbon tetrachlorlde adsor~ed from ~apour at 32 torr.
Increased ~ater-repellency was obtained by:
(a~ increasing the binder/activated charcoal ratio, (b~ applying a fluorochemical repellent by over-padding from aqueous ~ispersion ("FC 208"~ or organic solvent solution ("Tinotop T-10"), (c) addin~ a fluorochemical repellent ("FC 308") as part of the binder for the activated charcoal t ` (d~ adding "FC 2Q8" as part of the binder or the ;~ 30 activated charcoal and over-paddin~ with "Tinotop T-10"
in trichloroethylene solution.
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'. ' ", '... ,. ~ , The effectiveness of repellent trea~ment in preventing wetting by sweat was in the order a< b <c <d~ Some reduction in sweat poisoning was found for all treatments in one experiment or another, but the results were very variable. The variability was attributed to the practical difficulty of applying sweat evenly to material which is not readily wettable. It was obvious that the effect of mechanical action in working sweat into the material was a critical factor. The material with a double fluo-rochemical treatmen-~ ~d) was extremely repellent when dipped into water or sweat. When removed it remained dry but water could be forced into the pores of the material by m~chanical action.
Thought was given to devising a technique for appli cation of sweat to simulate the accumulation oi sweat in clothinq during wear, with the eventual conclusion tha-t the ~actors involved were too complex and that tests in actual wear were necessary to determine whether repellency was effective.
A few trials were made in which swatches o fabric were ~orn against the skin of the lower back of men dressed in chemical warare tC~ protective clothing and walking on a tread-mill under conditions which produced copious sweating.
Material with the double repellent treatment (d) was compared with normal material without repellent after being worn for 20 periods o~ one hour each day. Results are shown in Table I.
Table 1 Comparison o~ Watex Repellent Treated ~aterial with Untrea~ed Material aft.er Wearinq Lcss o charcoal Swea~ solids Material adsorptive capacity, accumulated, (~ersent~ ~/m~) ..
~ormal 37.9 23.8 38.& 17,1 ; 25.4 20.~
6.9 14.1 Repèlle`nE 12.7 9.4 trea~ed 20.2 11.1 14.2 4.4 11.6 6.
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The following examples demonstrate the effectiveness of fluoroch~mical treatment of laminated textile materials impregnated with activated carbon, in providing oil and water repellancy.
Fxam~le I - Pr~paration of Activated Carbon Dispersion 100 grams of "Activated Carbon Type BPL" (a trade-mark of Pittsburgh Chemical Company) was ground to a mass median diameter of 6 microns and dispersed by stirring into a solution of 3 grams of the ammonium salt of a styrene-maleic anhydride co-polymer thaving a molecular weight of 2500) in 147 grams of water.
Exam~le 2 - Preparation of Fluorochemical Resin Dispersion 7.14 grams of "Scotchgard FC 208~ was added to 100 grams of an aqueous solution containing 0.85 grams of medi~n viscosity carboxymethyl cellulose and 0.15 grams of high viscosity carboxymethyl cellulose. "Scotchgard FC 208"
(trade-mark of the 3M Company) is a fluorochemical resin emulsion containing 28% solids, and which is known to impart ``
oil and water repellency to textile fabrics. The solution of carboxymethyl cellulose was stirred vigorously as the "FC 20B"
:
was added slowly in a steady stream. ~ finely divided pre-cipitate of the fluorochemical resin was formed, was uniformly dispersed in, and remained suspended in the~ carboxymethyl cellulose solutiosl. Suitable yrades of carboxymethyl cellulose have subs-ti-tuti.on ranyes of 0.65 to 0.85, viscosity of 10-20 centipoises in 2% aqueous solution at 25C for the -medium viscosity grade, and viscosity of 1000-2800 centipoises in 1~ aqueous solution at 25C for the high viscosity grade.
Exarnple 3 . .
The fluorochemical resin dispersion of Example 2 was added, with stirring, to the activated carbon dispexsion -.. .
of Example 1. Finally, 40 grams of "Hycar 2671" was added , , , . :
.
I to form a stable dispersion which was used to impregnate fabric as set forth in subsequent examples. "~Iycar 2671"
(trade-mark of B.F. Goodrich Co.) is an emulsion of an acrylic ester elastomer containing 50~ solids.
Example 4 The impregnating bath of Example 3 was used to saturate a polyester type polyurethane open cell flexible foam, 5/32"
in thickness 100-110 cells per inch, weight 1.7 oz/sq. yd., laminated by the flame bonding process to a nylon tricot of I0 40 denier yarn, 36 wales and 42 courses per inch and weighing
This invention relates generally to materials which, while relatively permeable to air and water vapor, are resistant to the passage of noxious undesirable chemicals in the form of liquids and condensible vapors and gases. More particularly, the invention relates to the protection of such materials, and in particular gas protective clothing, from deterioration by exposure to sweat and sebum.
For protection against noxious chemicals such.as the gases and smokes employed in chemical warfare, and also against dangerous chemicals such as industrial poisons and pesticides which are generally in the form of sprays or mists, it is customary to use protective equipment and in particular protect-ive clothing which incorporates a gas and vapor adsorbent material.
Garments have been p.rov~ded which are made from fabric which is sufficiently permeable to air and water vapour to permit their use by humans with some degree of comfort for a reasonable period and at the same time provide protection from the undesirable ~ effects o~ noxious chemicals such as chemical warfare agents.
Such garments are described, for example, in British Patent 575,379 issued 15 February 1946 to Kingan, and U.S, Patent.
; 2,984,584 issued 16 May, 1.961 to Glarum. In these patents wo~en and non-woven fabrics are impregnated with an aclsorbent such ~as ~inely divided carbon which is held in place on the textile fibres by a polymeric binder.
The prerequisites of an ideal gas-proofed material, in particular for use as wearin~ apparel, are as follows: The material should be such that it adsorbs a relatively large amount of noxious chemicals such as chemical warfare agents ~:
while permitting oxygen or air to pass through; the supporti.ng mate~ial for the adsorbent should be substantially po.rous in :~ .
order to permlt perspiration or other liquîds to evaporate from X
- - . . ~
: ~ . . ~ . . :
~ 7~
the wearer's body; the material comprising the suppoxt should substantially retain its flexibility afker being co~bined with the gas adsorbent; and the gas adsorb~nt showld be substantially permanently bound to the supporting material in order to prevent the adsorbent from becoming dislodged from -the support by rain, laundering or rough usage or by the softening effect of moisture and perspiration. Finally the gas-proofed material should be capable of reuse after decontamination.
In Canadian Patent 878,560 of J.A. Hart, issued August 1017, 1971, an air and water vapour permeable open cell solid resin foam resistant to passa~e therethrough of noxious chemicals in liquid or vapor form, in which there is dispersed a particulate adsorbent material for said noxious chemicals, and laminated fabric materials, eg. in the form of protecti~e clothing, incorporating said foam, are describedO The particulate adsorbent material is bonded in said Eoam by an organic binder which is substantially free from sukstances which would substantially deactivate the adsorbent~ The laminated fabric materials described in this patent include an air and water vapor-permeable ~abric backin~ to which the aforesaid foam is bonded.
The adsorbent material in particulate form may be any solid part.iculate material capable of adsorbing the noxious chemiaals. Such adsorbent materials are well know ~ se in the art and include, for example, silica gel and active clays o~ the attapulgite and bentonite classes, e.gu fullerls earth.
A particularly preferred adsorbent material is activated carbon.
As pointed out in the aforesaid Canadian Patent ; 878,560, flexible Eoams do nQt ~ se possess high mechanical strength so that, for use in garments, it is the customary practice to bond, ie. laminate, the foam, in known manner, to a fabric, such as a knitted or woven textile material, for example, nylon tricot, cotton sheeting, canton flannel, poplin, ' ~ ' ~ -2-.
L6~
percale, etc. in order to provide a reinforced material. Instead of loose knit or woven fabrics, non woven fabrics such as netting or scrim may also be used to reinforce the foam. If the reinforcing fabric is also impregnated some additional resistance may be obtained in view o~ the additional adsorbent employed;
however this effect is usually minimal. The fabric is essentially for mechanical reinforcement and is bonded to the foam by known lamination techniques such as flame lamination, adhesive lami-nation, stitch bonding and quilting.
The preferred foams for use in the aforesaid laminated textile materials are flexible polyurethane foams such as those of the polyester and polyether types. However flexible foams of cellulose, polystyrene, vinyl polymers or polyesters may also be employed if desired.
The chemical warfare protective clothing adopted by the Canadian Armed Forces is based upon the activated carbon impregnated polyurethane foam and laminated textile materials in-corporating this foam, described in the aforesaid Canadian Patent 878r560 entitled "Gas Resistant Foam Material". In common with all chemical protective clothing materials in which activated carbon is the effective component, it is subject to degradation in performance due to the action of sweat and sebum. Practical trials have shown that the useful life of chemical protective clothing is limited more by the adverse effect of sweat on the gas adsorptive capacity of the activated carbon adsorbent, than by the effects of wear and tear on -the clothing. The adverse effect of sweat, often referred to as sweat-poisoning, is apparent even when the protective clothing is worn in temperate climatic conditions together with a ~as mask and auxiliary protection for 3n hands and feet, since the metabolic heat generated by modera-te activity lS not fully dissipated, but induces sweating.
' ~:
6C~
The components of sw~at which are adsorbed by activated carbon and thus degrade its ability to scavenge gases and vapours are the organic substances of which urea and salts of lactic acid form the greater part. The inorganic salts, although present in larger quantities, do not have so great an effect as the organic substances, but do contribute to the degradation of the carbon unless denied access.
The present invention seeks to reduce or eliminate the adverse effect of sweat on the gas scavenging property of activated carbon in clothing materials by use of a liquid repel-lent treatment to prevent access of sweat to the activated carbon~
It is necessary to preserve the porous structure of the clothing material so that gases and vapours may have free access to ~ :
the adsorption sites on the activated carbon or other adsorbent while restraining the movement of liquid sweat.
This can be achieved by applying as a thin film on the surfaces of the porous material, a substance for which water and other liquid has little affinity and does not wet. Such ~0 substances are commonly used for rendering various porous mater-ials such as textiles, paper and leather resistant to the penetration of li~uids.
The present invention, in its broadest method aspect, resides in a method of mi.nimi2iny the adverse e:E~ects of sweat and sebum on a f:Lexlble porous material which is permeable to air and water vapor:but is resistant to passage therethrough of - noxious chemicals in liquid or vapor form, said material con-~
tainin~ a particulate activated carbon which is an adsorbent for said noxious: chemlcals, which method comprises treating said . : 30 flexible, porous material containing said activated carbon ad-sorbent with a liquid organic polymeric water-and oil-repellant substance which is compatible with any s~stances employed to , ~7~
disperse or bind said particulate ac-tivated carhon adsorbent in said flexible porous material and being of a type which does not reduce to any significant ex~ent the adsorptive capacity of said activated carbon adsorbent.
:[n a more paxticular aspect, this invention resides in a method of minimizing the adverse effect of sweat and sebum on a laminated fabric material comprising an air- and water vapor-permeable open cell solid resin foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, the foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, which particulate activated carbon adso.rbent is bonded in said foam by an organic binder substantially free from substances which would substanti-ally deactivate said activated carbon adsorbent, and an air and water vapor-permeable fabric backing to whi.ch the ~oam is bonded.
Thi.s method comprises treating said air- and water vapor-permeable laminated materîal with a liquid organic polymeric water and oil-repellant substance which is compatible with said organic binder, and which is o~ a type which does not reduce to any sig- -nificant extent the adsorptive capacity of said activated carbon adsor~ent.
More particularly, the present invention resides in a method clS described above, but in which the repellent substance is one which contains a high proportion of pe:rfluorocarbon chains in the molecule~
In a ~urther aspect, this invention resides in a flex-ible porous material permeable to air and water vapor but resist- -an~ to passaye therethrough of noxious chemicals in liquid or vapor form, said material containing a particulate activated carbon ads~orbent for said noxious chemicals, and being further character-ized by being resistant to deactivation by sweat and sebum of said particulate activated carbon adsorbent material~ said flexible , porous material having been trea~ed with a liquid oryanic poly maric water-and-oil-repellent substance, said repellent substance being compatible with any s~stances employed to disperse or bind said particulate activated carbon adsorbent in said flex-ible porous material and being of a type which does not reduce to any significant extent the adsorptive capacity of said acti-vated carbon adsorbent.
The present invention~ in a more particular aspect, provides a method of minimizing the adverse effect of sweat and sebum on a laminated ~abric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in li.quid or vapor form, said foam being bonded to an air and water vapor-permeable fabric backing, said foam having dispersed therei.n particulate activated carbon adsorbent material for the noxiou,s chemicals, which particulate adsorbent material is bonded in said foam by an organic binder substant.ially free from substances which would substantially deactivate said adsorbent material, and an air-and water vapor-permeable fabric backing -to whi.ch the foam is bonded, which method comprises:
impregnating the adsorbent material with a first liquid organic polymeric water- and oil-~repellent substance containing a high proportion o~' per~luorocarbon chains, said repellent substance bei.ng compatible with said organic binder and being , ' of a type which does not reduce to any significant extent the adsorptive capacity of said'adsorbent, said impregna-ting OGcurring by mixing as an aqueous dispersion said activated carbon adsorbent material and said repellent substance;
applying said aqueous dispersion of activated carbon adsorbent ~0~ material and repellen~ substance to the laminated fabric ~aterial ~thereby impre~gnating the ~aasor~bent~'~materia~ within ~ -the~foam; drying the impregnated~laminated fabric~material;
: ' . :
- , . "
6~
dissolving in an organic solvent a second organic polymeric water and oil-repellent substance, different from said first substance, but also containing a high proportion of perfluorocarbon chains, be.ing compatible with the organic binder, and being of a type which does not reduce to any significant extent the adsorptive capacity o the adsorbent;
and applying the organic solvent-repellent solution to the dried impregnated laminated fabric material.
This invent:ion, in a still further aspect, provides a laminated fabric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, the p~rticulate activated carbon adsorbent being bonded in said foam by an organic binder substantially free from substances which would substantially deactivate said adsorbent, and an air-and water vapor-permeable fabric backing to which the foam is bonded; said laminated fabric material being urther characterized by being resistant to deactivation of said particulate activated carbon adsorbent by sweat and sebum, said laminated fabric material having been treated by the method defined in the immediately preceding paragraph.
It is essential that the liquid repellent substance used does not seriously reduce the adsorptive capacity of the activated carbon or other adsorbent. This is an impcrtant practical limitation since most of the known liquid repellent .
substances used in treatment of fabrics, paper, leather, etc.
are adsorbeù by activated carbon and block some or all of ~
the adsorption capacity ~hich is then not available for . -adsorption of gases. ~.
A suitable repellent substance is of polymeric nature .
Sb-Q
and of molecular size such that its molecules cannot penetrate i.nto the intern~l pores of the charcoal ill which yas adsorption takes place.
It is also desirable that the repellent substance creates a surface with the lowest possible affinity for liquid sweat for the residue of organic and inorganic substances left when sweat dries, or for the oily substances of sebum which : normally accomp~ny sweatO
Of all the li~uid repellent substances known to the water-proofing art, it is chiefly those containing a high pro-portion of perfluorocarbon chains which create a surface of sufficiently low energy as to repel oils, as well as the residue rom sweat dried upon the clothing and freshly secreted liquid : sweat. Because of this property they are the preferred repel-lents or exclusion of s~eat and the oily exudations from the skin. They may be applied to the activated carbon impregnated ~abric by impregnation or coa~ing from d.ispersion in water or organic solvents as ~or example by using a padding mangle. :.
The repellents may also be mixed into the di.spersion of acti- ~ :
vated carbon used to Lmpregnate thè fabric, which in the pre-:: ferred case is a polyurethane foam bonded to a textile. They may be applied to the activated carbon imprègnated ~abric by impregnation or coating ~rom dispersion in water as or example by using a padding mangle or organic solvents. The pre~erred and most effective method is to mix one repellent as an aqueous ~;: dispersion with the activated carbon aispersion, and after impregnation with this mixture and subsequent drying, to apply a second repellent dissol~ed in an organic so.lvent by a second ~ :impregnation operation. The water repellency created by the ~3Q first~treatment~renders it impossible to wet the material ~ suf~iciently well :to~ ~mpregnate:a second time with an aqueous :
: ~ fluid. ~An organic~asol~ent With su~ficiently low surface ~ 6- --tension is required.
A variety of fluorochemical oil and water repellent compounds suitable for use in the present invention are known and are commercially available. One particular group of fluoro-chemical oil repellents are the polymers obtained by polymerizing an ethylenically unsaturated fluorochemical compoundO The ethylenic unsaturation may be either in the alcohol or the acid portion of the ester molecule. Typically, the unsaturated radical ~n the alcohol portion of the ester may be the allyl radical or the vinyl radical. Typical unsaturated acids used to prepare the ester include acrylic acid, methacrylic acid and crotonic acid~ In general, the perfluoro portion of the molecule should be in the saturated portion of the molecule. The unsatu--rated portion of the molecule is preferably not fluorinated in each instance. The acid and alcohol radicals may suitably contain from 2 to 6 carbon akoms excluding the carbonyl carbon of the acid. Examples of such monomers include vinyl perfluoro-butyrate and perfluorobutylacrylate. These monomers may be polymerized as homopolymers or as copolymers by normal emulsion polymerization techniques using free radical catalysts.
Some of these repellents are disclosed in an article by E.J~ Grajeck and W.'~. Petersen`~appearing in ~he _xt~le 'Re's'e'arch''Jo'urnalr Apr~l, 1962/ pp. 320-331, entitled "Oil and Water Fluorochemical Finishes for Cotton".
E~amples of suitable ~luoxochemical repellents are those known and sold under the trademarks "~cotchgard FC 208", '"Scotch~ard FC 210", "Scotchgard FC 232", and Scotchgard FC 319", manufactured by the 3M Company, "Zepel B" manufactured by E,I. DuPont~de Nemours and Co. and "Tinotop T-10" manufactured ~; 30 by Ciba-Geigy Ltd.~
O~ these~ materials "Scotchgard FC 208" is an aqueous nonionic emulsion containin~ approximately 28% by weight of ; ~-7- ~' .
a modified ~luorinated acrylic polymer. a substance believed to be of tne following approximate yeneral formula:
F3C (C F2)x SO2l R O ~ C CH3 R O
in which x is a value between 3 and 13 inclusive, Rl is lower alkyl, such as methyl, ethyl, propyl, and the like, having 1-6 carbon atoms; R2 is alkylene containing 1-12 carbon atoms and ~3 is H, methyl or ethyl. The product ~læepell~ is also available in emulsion form and while it is chemically difrerent from the "Scotchgard" products, it is a fluorochemical oil repellent containing fluorocarbon tails composed of CF2 groups which may end in a terminal CF3 group.
"Scotchgard FC-319" is a solution of a compound similar to "FC-208'l in an organic solvent. "Scotchgard FC-232" is a dispersion of a fluorochemical resin in a mixture of water and methyl isobutyl ketone. "~epel B" is an a~ueous cationic dispersion o~ a fluorochemical resin and is a product of E~Io Dupont de Nemours~ and Company. The exact compositions of these products are not known to this applicant but they ~ fall~wlthin the;alasses Oe compaunds disclosed in the following .
pa~ent specifications:
British Patent 971,732 E.I. Dupont de Nemours & Co~
Canadian Patent 942,900 E.K. Kleiner (Ci~a-Ceigy Co.) Canadian Patent 697,656 R~W~ Fasic]c et al (Dupont) .. .
F~ench Patent ~ 1,568,181 H. Stockman (National Staxch ~ ~ ~ & Chemical Co.) U.S. Patent 2,~03,615 ~.H. Ahlbrecht et al ~3M Co.
U.S. Patent 2,826,564 F.A. Bovey et al ~3M CoO~
.
30~~U.S. Patent~ 2,642,416 ; ~ Ah1brecht et al ~3M Co.) UOS~ Patent 2,839/513 ~7H. A7nlbrecht et al C3M Co.~
U.S. Patent 2,841,573 ~ A~H. ~hlbrecht et al (3M Co.) ; ~U.S. Patent 3,~484 j281 RoAo Guenther et al (3M Co.
~: :
: . .
~ ~ n ~
U.S. Patent 3,462,296 S. Raynolds et al (Dupont) U.S. Patent 3,636,085 E.K. Kleiner (Ciba-Geigy) U.S. Patent 3,594,353 E. Domba (Nalco Chemical Co~) French Patent 1,562,070 P. Sherman (3M Co.~
German Patent 1,419,505 E. Langerak (Dupont) U.S. Patent 3r256,230 R.E. Johnson et al (Dupont) For application of fluorochemicals from organic solvents the choice of solvent is limited by the solubility characteristics of the fluorochemical. In general, suitable ~luorochemical polymers are soluble in chlorinated or fluorinated hydrocarbons or in mixtures with other solvents such as esters, ketones and aromatic hydrocarbons. . :
Although the best results wlll be obtained by using .
fluorochemical repellents, a lesser degree of resistance to sweat poisoning could be obtained with other repellents. One example of a suitable repellent in wh.ich the repellent :Eunction is due to hydrocarbon side groups instead of perfluorocarbon side groups is the polymer of n-octyl methacrylate or of 2 ethylhexyl methacrylate. Such polymers can be incorporated wlth~an aqueous dispersion of activated carbon when prepared as~an:~aqueous emu1s;~on, or~in:solution wi:th a dispersion of ac-tivated:c~r~Qn ln an organ~c sol~ent. They may also be : applied in solution to a .~abric pre~iously impregnated with activated carbon. Siliconq resins may also be employed in some instances~ The essential requi.r.ements are that the substance used creates ~a~swea~t repellent surfac:e and that it does not cause~.substantial deactivation of the activated carbon.
To make the process work success~ully the repellent must be~an e~eati~e o~e, and:it must be~applied (either ~
. .
~30 ~ ~ogether;with the.activa~ed~carbon; or as a second step) in sufficient~yuantity~ to;~be ef~ective~ln ~reating a~surface whi:~h;~sw~at~does~ot;~:wet.~: The;~repellent substance must also ~ _ 9 _ , ,. - . , - ., , , ~.
6~
be compatible with other substances employed for the purposes of dispersing or binding the activated carbon. Thus if an anionic latex of a binder resin is used a cationic dispersion of repellent would not be compatible, but an anionic or non-ionic dispersion ~could be used.
The present invention will now be further described, with reference to tests which have been conducted. These tests show that the method of the present invention is effective in reducing the adverse effects of sweat and sebum on the adsorp-tivit~ of adsorbent materials contalned in laminated textilematerials as previously described.
Sweat was collected from men exercising in garments impervious to the passage of gases and vapors by centrifuging sweat-soaked cotton underwear. It was applied to the chemical barrier material in a tray, worked into the ~abric by means of a roller squeegee, and then allowed to evaporate in situ. This proceclure was repeated as man~ as twenty times until the weight of sweat solids accumulated amounted to at least the weight of the activated charcoal present~ The adsorptive capacity of the material was measured by the amount of carbon tetrachlorlde adsor~ed from ~apour at 32 torr.
Increased ~ater-repellency was obtained by:
(a~ increasing the binder/activated charcoal ratio, (b~ applying a fluorochemical repellent by over-padding from aqueous ~ispersion ("FC 208"~ or organic solvent solution ("Tinotop T-10"), (c) addin~ a fluorochemical repellent ("FC 308") as part of the binder for the activated charcoal t ` (d~ adding "FC 2Q8" as part of the binder or the ;~ 30 activated charcoal and over-paddin~ with "Tinotop T-10"
in trichloroethylene solution.
~ :' ~; -10-: ,.
'. ' ", '... ,. ~ , The effectiveness of repellent trea~ment in preventing wetting by sweat was in the order a< b <c <d~ Some reduction in sweat poisoning was found for all treatments in one experiment or another, but the results were very variable. The variability was attributed to the practical difficulty of applying sweat evenly to material which is not readily wettable. It was obvious that the effect of mechanical action in working sweat into the material was a critical factor. The material with a double fluo-rochemical treatmen-~ ~d) was extremely repellent when dipped into water or sweat. When removed it remained dry but water could be forced into the pores of the material by m~chanical action.
Thought was given to devising a technique for appli cation of sweat to simulate the accumulation oi sweat in clothinq during wear, with the eventual conclusion tha-t the ~actors involved were too complex and that tests in actual wear were necessary to determine whether repellency was effective.
A few trials were made in which swatches o fabric were ~orn against the skin of the lower back of men dressed in chemical warare tC~ protective clothing and walking on a tread-mill under conditions which produced copious sweating.
Material with the double repellent treatment (d) was compared with normal material without repellent after being worn for 20 periods o~ one hour each day. Results are shown in Table I.
Table 1 Comparison o~ Watex Repellent Treated ~aterial with Untrea~ed Material aft.er Wearinq Lcss o charcoal Swea~ solids Material adsorptive capacity, accumulated, (~ersent~ ~/m~) ..
~ormal 37.9 23.8 38.& 17,1 ; 25.4 20.~
6.9 14.1 Repèlle`nE 12.7 9.4 trea~ed 20.2 11.1 14.2 4.4 11.6 6.
~:~7~
The following examples demonstrate the effectiveness of fluoroch~mical treatment of laminated textile materials impregnated with activated carbon, in providing oil and water repellancy.
Fxam~le I - Pr~paration of Activated Carbon Dispersion 100 grams of "Activated Carbon Type BPL" (a trade-mark of Pittsburgh Chemical Company) was ground to a mass median diameter of 6 microns and dispersed by stirring into a solution of 3 grams of the ammonium salt of a styrene-maleic anhydride co-polymer thaving a molecular weight of 2500) in 147 grams of water.
Exam~le 2 - Preparation of Fluorochemical Resin Dispersion 7.14 grams of "Scotchgard FC 208~ was added to 100 grams of an aqueous solution containing 0.85 grams of medi~n viscosity carboxymethyl cellulose and 0.15 grams of high viscosity carboxymethyl cellulose. "Scotchgard FC 208"
(trade-mark of the 3M Company) is a fluorochemical resin emulsion containing 28% solids, and which is known to impart ``
oil and water repellency to textile fabrics. The solution of carboxymethyl cellulose was stirred vigorously as the "FC 20B"
:
was added slowly in a steady stream. ~ finely divided pre-cipitate of the fluorochemical resin was formed, was uniformly dispersed in, and remained suspended in the~ carboxymethyl cellulose solutiosl. Suitable yrades of carboxymethyl cellulose have subs-ti-tuti.on ranyes of 0.65 to 0.85, viscosity of 10-20 centipoises in 2% aqueous solution at 25C for the -medium viscosity grade, and viscosity of 1000-2800 centipoises in 1~ aqueous solution at 25C for the high viscosity grade.
Exarnple 3 . .
The fluorochemical resin dispersion of Example 2 was added, with stirring, to the activated carbon dispexsion -.. .
of Example 1. Finally, 40 grams of "Hycar 2671" was added , , , . :
.
I to form a stable dispersion which was used to impregnate fabric as set forth in subsequent examples. "~Iycar 2671"
(trade-mark of B.F. Goodrich Co.) is an emulsion of an acrylic ester elastomer containing 50~ solids.
Example 4 The impregnating bath of Example 3 was used to saturate a polyester type polyurethane open cell flexible foam, 5/32"
in thickness 100-110 cells per inch, weight 1.7 oz/sq. yd., laminated by the flame bonding process to a nylon tricot of I0 40 denier yarn, 36 wales and 42 courses per inch and weighing
2.0 oz/sq. yd. Excess liquid was removed by passing the laminate through the squeeze rolls o a padding mangle. The laminate was then heated to 150C for 10 minutes to cure the binder.
The impregnated fabric was repellent to water and to oil.
Drops of water placed on the fabric did not wet the fabric but stood on the surface, small drops being nearly spherical, thus showing a high contact angle. When tested for oil repellency by the Hydrocarbon Resistance Test 118-1966 of the American Association of Textile Chemists and Colorists a ~ rating of 4 was found. This indicates a high level of repellency against hydrocarbon liquids.
,,, ~
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The impregna-ted fabric oE Example 4 was impregnated by saturating with ~ solution of 6~ by weight of "Tinotop T-10" in trichloroethylene. "Tinotop T-10" (trade-mark of Ciba-GeigY Corporation) is a solution of a fluorochemical resin composition in a chlorinated hydrocarbon solvent and is known to impart oil and water repellent properties to textile fabrics. Excess liquid was removed by passing the fabric through the squeeze rolls of a padding mangle~ The fabric was air dried to remove solvent. The water repellency .
. ~ 7~
. of th~ fabric was increased by tlliS trea~lent. Wh~n dipped into water to a depth of 2 inches and removed the fabric re-mained dry~ ~hen tested for oil repellency by the AATCC
~Iydrocarbon Resistance Test 118~].966 a rating of 7 was found.
.
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The impregnated fabric was repellent to water and to oil.
Drops of water placed on the fabric did not wet the fabric but stood on the surface, small drops being nearly spherical, thus showing a high contact angle. When tested for oil repellency by the Hydrocarbon Resistance Test 118-1966 of the American Association of Textile Chemists and Colorists a ~ rating of 4 was found. This indicates a high level of repellency against hydrocarbon liquids.
,,, ~
: ~ .
The impregna-ted fabric oE Example 4 was impregnated by saturating with ~ solution of 6~ by weight of "Tinotop T-10" in trichloroethylene. "Tinotop T-10" (trade-mark of Ciba-GeigY Corporation) is a solution of a fluorochemical resin composition in a chlorinated hydrocarbon solvent and is known to impart oil and water repellent properties to textile fabrics. Excess liquid was removed by passing the fabric through the squeeze rolls of a padding mangle~ The fabric was air dried to remove solvent. The water repellency .
. ~ 7~
. of th~ fabric was increased by tlliS trea~lent. Wh~n dipped into water to a depth of 2 inches and removed the fabric re-mained dry~ ~hen tested for oil repellency by the AATCC
~Iydrocarbon Resistance Test 118~].966 a rating of 7 was found.
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Claims (28)
1. A method of minimizing the adverse effects of sweat and sebum on a flexible porous material which is permeable to air and water vapor but is resistant to passage therethrough of noxious chemicals in liquid or vapor form, said material containing a particulate activated carbon which is an adsorbent for said noxious chemicals, which method comprises treating said flexible, porous material containing said activated carbon adsorbent with a liquid organic polymeric water-and-oil repellent substance, said repellent substance being compatible with any substance employed to disperse or bind said particulate activated carbon adsorbent in said flexible porous material and being of a type which does not reduce to any significant extent the adsorptive capacity of said activated carbon adsorbent.
2. A method as set forth in claim 1 wherein the liquid organic polymeric water-and-oil repellent substance contains a high proportion of perfluorocarbon chains in the molecule.
3. A method of minimizing the adverse effect of sweat and sebum on a laminated fabric material comprising an air-and water vapor-permeable open cell solid resin foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, which particulate activated carbon adsorbent is bonded in said foam by an organic binder substantially free from substances which would substantially deactivate said activated carbon.
adsorbent, and an air and water vapor-permeable fabric backing to which the foam is bonded, which method comprises treating said air and water vapor-permeable laminated material containing said activated carbon adsorbent with a liquid organic polymeric water- and oil-repellent substance, said repellent substance being compatible with said organic binder and being of a type which does not reduce to any significant extent the adsorptive capacity of said activated carbon adsorbent.
adsorbent, and an air and water vapor-permeable fabric backing to which the foam is bonded, which method comprises treating said air and water vapor-permeable laminated material containing said activated carbon adsorbent with a liquid organic polymeric water- and oil-repellent substance, said repellent substance being compatible with said organic binder and being of a type which does not reduce to any significant extent the adsorptive capacity of said activated carbon adsorbent.
4. A method as set forth in claim 3 wherein the liquid organic polymeric water-and-oil repellent substance contains a high proportion of perfluorocarbon chains in the molecule.
5. A method according to claim l or claim 3 wherein said repellent substance is applied as a thin film on the surface of said air and water vapor-permeable material.
6. A method according to claim 4 wherein said repellent substance is applied to the laminated fabric material by impregnation or coating from a dispersion of said substance in water.
7. A method according to claim 4 wherein said repellent substance is applied to the laminated fabric material by impregnation or coating from a solution of said substance in an organic solvent.
8. A method as in claim 4 wherein the foam is a flexible polyurethane foam.
9. A method as in claim 4 wherein there is formed a combined dispersion of the adsorbent and said water-and oil-repellent substance in water or an organic solvent, and said combined dispersion is applied to the laminate of foam and fabric backing, whereby the laminated fabric material is impregnated with both the activated carbon adsorbent and the water-and oil-repellent substance in one operation.
10. A method as in claim 4 wherein two different organic polymeric water-and oil-repellent substances of the nature and type recited in claim 4 are employed, and in which the first of said repellents is applied to said laminated fabric material in admixture, in the form of an aqueous dispersion, with the activated carbon adsorbent; the material so treated is then dried; the second of said repellent sub-stances is dissolved in an organic solvent, and the solution is then applied to the thus-treated laminate material.
11. A method as in claim 4 or claim 10 wherein the repellent substance is an aqueous nonionic emulsion containing approximately 28% by weight of a modified fluorinated acrylic polymer, known under the trademark "Scotchgard FC 208".
12. A method as in claim 4 or claim 10 wherein the repellent substance is an aqueous cationic dispersion of a fluorochemical resin, known by the trademark "Zepel B".
13. A method as in claim 7 wherein the organic solvent is perchloroethylene.
14. A flexible porous material permeable to air and water vapor but resistant to passage therethrough of noxious chemicals in liquid or vapor form, said material containing a particulate activated carbon which is an adsorbent for said noxious chemicals, and being further characterized by being resistant to deactivation by sweat and sebum of said particulate activated carbon adsorbent, said flexible porous material having been treated with a liquid organic polymeric water-and oil-repellent substance, said repellent substance being compatible with any substances employed to disperse or bind said particulate activated carbon adsorbent in said flexible porous material and being of a type which does not reduce to any significant extent the adsorptive capacity of said activated carbon adsorbent.
15. A material as defined in claim 14 wherein the liquid organic polymeric water-and oil repellent substance contains a high proportion of perfluorocarbon chains in the molecule.
16. A laminated fabric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, the particulate activated carbon adsorbent being bonded in said foam by an organic hinder substantially free from substances which would substantially deactivate said adsorbent, and an air-and water vapor-permeable fabric backing to which the foam is bonded, said laminated fabric material being further characterized by being resistant to deactivation of said particulate activated carbon adsorbent by sweat and sebum, said laminated fabric material having been treated with a liquid organic, polymeric water-and oil-repellent substance, said repellent substance being compatible with said organic binder and being of a type which does not reduce to any significant extent the adsorptive capacity of said activated carbon adsorbent.
17. A laminated fabric material as defined in claim 16 wherein the liquid organic polymeric water-and oil-repellent substance contains a high proportion of perfluorocarbon chains in the molecule.
18. A laminated fabric material as in claim 17 wherein the foam is a flexible polyurethane foam.
19. A laminated fabric material as in claim 17, when in the form of a garment.
20. A laminated fabric material as in claim 17 in which the fabric backing is an air-and water vapor-permeable knitted fabric.
21. A laminated fabric material as in claim 17 in which the repellent substance is an aqueous nonionic emulsion containing approximately 28% by weight of a modified fluorinated acrylic polymer, known by the trademark "Scotchgard FC 208".
22. A laminated fabric material as in claim 17, in which the repellent substance is an aqueous cationic dispersion of a fluorochemical resin, known by the trademark "Zepel B".
23. A laminated fabric material as in claim 17 in which said material has been treated with two different organic polymeric water-and oil-repellent substances of the nature and type recited in claim 17.
24. A method of minimizing the adverse effect of sweat and sebum on a laminated fabric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam being bonded to an air-and water vapor-permeable fabric backing, said foam having dispersed therein particulate activated carbon adsorbent material for the noxious chemicals, which particulate adsorbent material is bonded in said foam by an organic binder substantially free from substances which would substantially deactivate said adsorbent material, and an air-and water vapor-permeable fabric backing to which the foam is bonded, which method comprises:
impregnating the adsorbent material with a first liquid organic polymeric water-and oil-repellent substance containing a high proportion of perfluorocarbon chains, said repellent substance being compatible with said organic binder and being of a type which does not reduce to any significant extent the adsorptive capacity of said adsorbent, said impregnating occurring by mixing as an aqueous dispersion said activated carbon adsorbent material and said repellant substance;
applying said aqueous dispersion of activated carbon adsorbent material and repellent substance to the laminated fabric material thereby impregnating the adsorbent material within the foam;
drying the impregnated laminated fabric material;
dissolving in an organic solvent a second organic polymeric water-and oil-repellent substance, different from said first substance, but also containing a high proportion of perfluorocarbon chains, being compatible with the organic binder, and being of a type which does not reduce to any significant extent the adsorptive capacity of the adsorbent; and applying the organic solvent-repellent solution to the dried impregnated laminated fabric material.
impregnating the adsorbent material with a first liquid organic polymeric water-and oil-repellent substance containing a high proportion of perfluorocarbon chains, said repellent substance being compatible with said organic binder and being of a type which does not reduce to any significant extent the adsorptive capacity of said adsorbent, said impregnating occurring by mixing as an aqueous dispersion said activated carbon adsorbent material and said repellant substance;
applying said aqueous dispersion of activated carbon adsorbent material and repellent substance to the laminated fabric material thereby impregnating the adsorbent material within the foam;
drying the impregnated laminated fabric material;
dissolving in an organic solvent a second organic polymeric water-and oil-repellent substance, different from said first substance, but also containing a high proportion of perfluorocarbon chains, being compatible with the organic binder, and being of a type which does not reduce to any significant extent the adsorptive capacity of the adsorbent; and applying the organic solvent-repellent solution to the dried impregnated laminated fabric material.
25. A method as in claim 24, wherein the repellent substance is an aqueous nonionic emulsion containing approximately 28% by weight of a modified fluorinated acrylic polymer.
26. A method as in claim 24, wherein the repellent substance is an aqueous cationic dispersion of a fluorochemical resin.
27. A method as in claim 1 wherein the organic solvent is perchloroethylene.
28. A laminated fabric material comprising an air-and water vapor-permeable open cell flexible polyurethane foam resistant to passage therethrough of noxious chemicals in liquid or vapor form, said foam having dispersed therein a particulate activated carbon which is an adsorbent for the noxious chemicals, the particulate activated carbon adsorbent being bonded in said foam by an organic binder substantially free from substances which would substantially deactivate said adsorbent, and an air-and water vapor-permeable fabric backing to which the foam is bonded; said laminated fabric material being further characterized by being resistant to deactivation of said particulate activated carbon adsorbent by sweat and sebum, said laminated fabric material having been treated by a method as defined in claim 24.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA262,992A CA1107160A (en) | 1976-10-08 | 1976-10-08 | Sweat resistant gas protective material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA262,992A CA1107160A (en) | 1976-10-08 | 1976-10-08 | Sweat resistant gas protective material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1107160A true CA1107160A (en) | 1981-08-18 |
Family
ID=4107021
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA262,992A Expired CA1107160A (en) | 1976-10-08 | 1976-10-08 | Sweat resistant gas protective material |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1107160A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005118280A1 (en) | 2004-05-26 | 2005-12-15 | Gore Enterprise Holdings, Inc. | Durable covering for chemical protection |
-
1976
- 1976-10-08 CA CA262,992A patent/CA1107160A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005118280A1 (en) | 2004-05-26 | 2005-12-15 | Gore Enterprise Holdings, Inc. | Durable covering for chemical protection |
| US7704598B2 (en) | 2004-05-26 | 2010-04-27 | Gore Enterprise Holdings, Inc. | Durable covering for chemical protection |
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