Note: Descriptions are shown in the official language in which they were submitted.
. CA 02243339 l998-l0-07
CPW 50525
Treatment of Fabrics
This invention relates to a method of imparting wrinkle and/or crease and/or shrink resistance and/or
smooth drying prope, lies to fabrics made from cellulosic fibres or yarns or blends containing
5 cellulosic fibres or yarns. More particularly it relates to such a method of l,~t",ent which does not
involve the use of runll ~ehyde or for", ~ehyde derivatives or phosphorus containing compounds.
Many cor"",er- ;al processes for imparting wrinkle crease and/or shrink resistance and/or smooth
drying prope, lies to cellulosic fabrics particularly cotton textiles are known. The treated fabrics and
10 ga""er,l~ made from them retain their dimensions and smooth appearance in use and also during
machine wash and tumble dry processes.
Cor"" ,t:, ~.ially such p~ upe~ lies can be i" ,pa, led to cellulosic fabrics by a finishing l, ~:al" ,e"l with
resinous compositions. The most con""only used resins for such finishing are based on
15 ror",~ ~ehyde derivatives such as formaldehyde-urea or substituted urea addition products such as
DMEU and DMDHEU. Such resins are believed to function by prur"uli"g crosslinking of the cellulose
in the fabric thereby illlpallillg the desired properties. In recent years efforts have been made to
develop cr-ss ,hing agents which do not include for", ~ehyde or its derivatives to remove the
possible evolution of ru""- ~ehyde during manufacture storage and/or use of ao ~'ase particularly
20 cotton fabrics treated with formaldehyde addition products.
Non-rur",~ 'ehyde crosslinking agents which have been suggested previously include polycarboxylic
acids as ~ic~lclsed by Gaghiardi and Shipee American Dyestuff Reporter 52, 300 (1963). Rowland
et al., Textile Research Journal 37 393 (1967), ~:I;srlosed the use of partially neutralized
25 polycarboxylic acids with base prior to the zppl ~ ~ 'icn to the fabric in a pad dry and heat cure
treatment elaborated US Patent 3526û48. Canadian Patent No 2097483 describes rapid
e~l~riri.;~lion and c,- s~ Ihing of fibrous cellulose in textile form using boric acid or derivatives as
crosslinking catalyst.
30 Welch et al. in US Patents 4975209,4820307,4936865 and 5221285 disclose the use of alkali metal
salts of phosphorus cor, , ,g acids particularly sodium hypophosphite as closslil, ,g esle,ifi-;alion
catalysts in the l,t:~l",ent of cellulosic ",aterials. The use of sodium hypophosphite has several
disadvanlages: it is expensive relatively high levels are needed in practice and it tends to cause
shade changes in fabrics dyed with sulphur dyes or certain reactive dyes. In addition phosphorus
35 containing effluents can promote algal growth and/or eul,ùph.~ ~ion of dow"sl,t:c", water bodies
such as streams and lakes.
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CPW 50525
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The present invention is based on the discovery that certain sulphur containing acids, particularly
sulphonic and/or sulfinic acids, and their alkali metal salts at lower concenl, dlion show accele. dlil ,9
effect on esle,iricalion and c,.s-' ,hillg of e,-" I'ose by polycarboxylic acids. The use of such
catalysts can enable the provision of a treatment method that uses neither rur", 'Jehyde derivatives
5 or phosphorus compounds, but can give adequately rapid esleriricdlion and ~,.s~l ~king of cellulosic
in fibres to provide effective wrinkle, crease or shrink resistance or smooth drying properties to
I l Idt~:l ials made from such cellulosic fibres. Thus, in this invention fibrous cellulosic material is
treated with a polycarboxylic acid in the presence of a sulphonic and/or sulfinic acid curing catalyst at
elevated le"")er..ture. The process can be carried out by i",prey"dli"g the material with a solution
10 containing the polycarboxylic acid and the curing catalyst followed by heat l,~al",enl to produce
eslt:, iriudlion and crosslinking of the cellulose with the polycarboxylic acid.
The present invention accordingly provides, a method of treating fibrous cellulosic textile material
which coll~prises
15 a applying to the cellulosic textile material an aqueous solution including at least one
polycarboxylic acid as a crosslinking agent for the cellulose and an organic or illOIydll.c sulphonic or
sulfinic acids or a salt as an este, iricdlion catalyst,
b drying the textile material fabric and heating it to promote crosslinking eslel iri~;dlion of the
polycarboxylic acid and the cel' 1' e se of the cellulosic textile material.
In rt:r~r,ing to the material as being "ee'lu' e s ", we mean that the major part of the fibre forming
components of the material is ce'lu'ose. Thus, the term includes purely cellulosic ",ateri31s such as
cotton and cellulose-rich blends particularly cellulose-rich polyester blends, such as polycotton
",dlerials. Typically, the material contains from 30 to 100% of cellulosic fibres. Typical cellulosic
25 fibre " Idtel i~li which can be included in fabrics treated according to this inventions include cotton,
flax, rayon, jute, hemp and ramie. It can also be a synthetic cellulosic fibre material such as rayon,
particularly viscose rayon or solvent derived rayon co"""only called Iyocell fibre. The cellulosic
material can be a blend of fibres of cellulosic Illdterials with non-cellulosic r"d~r;als and in particùlar
includes blends of cellulosic fibres, particularly cotton, with polyester, particularly polyethylene
301~lephllldldll~ polymer or related copolymers. The textile can be a woven (including knitted) or
non-woven textile, but as crease resistance is particularly i"",o, Ldlll in clothing, the textile will usually
be a clothing textile material.
The term ror",-'ie'lyde free" means that the process does not release rur",~'~ehyde during the
351lt:dlll ,enl of the fabric with the resin or during 5llhsequent manufacture of gd""erlls or their use
including washing and wearing. The term "wrinkle or crease ,esi:,ldnce" means that a treated fabric
is less likely to be wrinkled or creased after being worn or after a laundering operation than it would if
it had not been so treated.
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CPW 50525
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The invention uses polycarboxylic acids as cellulose crosslinking agents to improve the wrinkle
, esislance shri"!<2ge, t:~ialdl)ce and smooth drying prupe, lies of cellulosic fibre containing textile
without the use of rO"" ~ ~ hyde or agents that release rc" " ,- 'dehyde. Some such polycarboxylic
5 acids are known from the literature. Suitable polycarboxylic acids for use in the method of this
invention include aliphatic including open chain and alicyclic polycarboxylic acids and alullldlic
polycarboxylic acids. Desirably the polycarboxylic acid includes at least 3, particularly at least 4 and
often more carboxylic acid groups per molecule.
1û Particularly suitable aliphatic polycarboxylic acids include acids in which at least two carboxylic acid
groups are separated by 2 or 3, more usually 2 carbon atoms and desi, alJly where the poly-
carboxylic acid includes a plurality of such arranged pairs of carboxylic acid groups. Where such an
aliphatic acid includes an ethylenic double bond it is very desil_- e that it is positioned a"~- to a
carboxylic acid group; such an aliphatic acid may include a hydroxyl group on a carbon atom also
15 carrying a carboxylic acid group; and further the aliphatic chain or ring may include one or more
oxygen and/or sulphur atoms. Suitable a~l"atic acids include those where at least two carboxylic
acid groups are dLld~;l ,ed to adjacent a(o" ,atic ring carbon atoms.
EXdlll, es of suitable aliphatic polycarboxylic acids include maleic acid methyl~" c (~;it,dconic)
20 acid citric acid itaconic acid 1 2 3-p~upan~ .dllJoxylic acid 1 2 3 4-butanetelldcdllJoxylic acid
(con""only known as BTCA) all cis-1 2 3 4-cy~ loper,tanetel,d~d,l,oxylic acid oxydisuccinic acid
lll ;uccinic acid; oligo- and/or poly-maleic acid and/or anhydride (as described in GB 22954û4 A
and WO 96/26314 A and abbreviated OMA ) and suitable a,ur,,aliG polycarboxylic acids include
benzene he,~dca, bù~ylic acid and trimellitic acid.
The amount of crosslinking agent used will typically be from 1 to 10% particularly from about 2 to
about 7% by weight based on the dry fabric weight. The particular concer,l,~lion of crosslinking
agent used in the treating solution will depend upon the degree of cross linking desired the
p,opo, lion of r ~' Ik~ic fibres in fabric being treated and the solubility of the crosslinking agent.
30 Typically the conce"l,dlion is from about 1 to 2û%, more usually 2 to 10% particularly from 0.5 to 7
and especially about 5%, by weight of the solution.
The curing catalysts used in this invention are organic or inorganic sulphonic or sulfinic acids or their
salts. Suitable catalysts include inorganic sulphonic acids i.e. compounds including the group
35 SO3H (or SO2OH) particularly halosulphonic and amidosulphonic acids particularly those of the
general formula: XSO2OH where X is Cl F or NH2 respectively chlorosul, hon ~ andfluorosulphonic acids and dlll '~ honic acid (taurine). Suitable organic sulphonic acids typically
~PW50525 CA 02243339 1998-10-07
have the general formula: RSO2OH where R is an organic group, particularly an alkyl or cycloalkyl
group, an unsaturated straight or branched chain h)~dlocbl l,yl, particularly alkenyl group, or an
unsaturated cyclic or arene group.
Particularly active and effective curing catalysts of this invention include the alkane sulphonic acids
and their alkali metal salts e.g. methane, ethane, propane, butane, pentane and hexane sulphonic
acids, ca",phor sulphonic acid, ist:ll, un ~ acid (2-hydroxyethane sulphonic acid), methane-
di-sulphonic acid and trifluorc,i"~ll,anesul, hon r acid. Other useful curing catalysts include arene
and alkyl arene sulphonic acids such as benzene, p-hydroxybenzene, p-toluene anddodecylbenzene sulphonic acids, naphll,-'ene-1- and na~l,a'ene-2-sulphonic acids and 1,3-benzene
and 2,6-naphthalene disulphonic acids and benzene sulphinic acid.
The sulphonic or sulfinic acid catalyst can be used as the free acid or as a salt, particularly an alkali
metal, a"""onium or alkaline earth metal salt, or a mixture of the free acid and a salt or salt(s). The
salt forming cations are particularly of potassium, sodium, a"""onium, magnesium, calcium or a
mixture of these cations. It is not clear whether the free acid form or the salt form of the curing
catalyst is the more active component of the catalyst. The form present will depend on the acidity of
the solution used for the ll~:dllll~lll of the textile and the effect of the drying and heating steps. We
have found that the textile is advantageously treated using a ",oderdtely acidic solution, typically
having a pH of from 2 to 6, usually not more than 4.5, more usually from 2.5 to 4 and especially
about 3. Under such conditions, the curing catalyst may be present as the neutral free acid, as acid
anions or a mixture depending on the acidity of the catalyst. Generally sulphonic acids are strong
enough acids that they will be present as the free acid (often largely .I;ssoc~ ed) in aqueous solution
at pH about 3.
The amount of catalyst used will typically be from 10 to 200%, more usually 25 to 150%, desi,ably 50
to 120%, by weight of the polycarboxylic acid .;, ussli"kirlg agent. Ex~lr~ssed as a per.;e"ldge based
on the (dry weight of the) textile being treated, the amount will typically be from 1 to 30%, more
usually from 2 to 20%, particularly 2.5 to 10% by weight. The concer,l,dtion used in the llt:dllllant
solution is typically from 0.1 to 20%, more usually from 0.2 to 10%, particularly from 0.5 to 7%, by
weight of the solution.
The l,~dl",er,l is typically carried out by first illl~ ylldlillg the cellulosic or cellulosic containing textile
l"dl~r;als with an aqueous treating solution containing the crosslinking agent and the curing catalyst,
and removing excess liquid e.g. using wringers, with these steps being repeated if necessary, to
obtain the desired liquid pick up. The material is then dried to remove the solvent and then cured,
e.g. in an oven, typically at about 150 to 240~C, usually from 160 to 200~C for a time of from 5
seconds to 30 minutes, usually 1 to 5 minutes to promote the esle, iri-,dlion and crosslinking of the
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cellulose by the polycarboxylic acid. Typically the pick up of lle~llllenl solution is from 30 to 120%,
more usually from 50 to 100%, particularly about 80% of the dry weight of the U~ aled textile.
We have cor,ri""ed the presence of cell~ se ester carbonyl groups in material treated according to
5 the invention by FT-IR (Fourier lldll~rur", infra red) spe~;t,uscopy. The absorption band of the
carbonyls of cellulose esters in infra red spectra has been reported and in the range of 1720 to
1750 cm 1 (Zhbankov, P.G., "Infrared spectra of cellulose and its derivatives", Consultant Bureau,
New York, 1968, pp 315-316). Our observations show an abso",lion peak at about 1720 to
o1735 cm~1 .
The 1, edLIII~III solution containing the c, ossli,)hi, ,9 agent and the curing catalyst forms part of the
invention which accordingly specifically includes an aqueous solution of at least in one polycarboxylic
acid cellulose crosslinking agent, particularly at a concer,l,dlion of from 1 to 20% by weight of the
15 solution, and at least one organic or inorganic sulphonic or sulfinic acids or a salt as an esteriricatio
catalyst, particularly at a concentration of from 0.2 to 10% by weight of the solution.
The invention further includes cloth treated by the method of the invention and in particular, a
cellulosic textile material, which may be woven (including knitted) or non-woven, which carries
20 residues of at least in one polycarboxylic acid cellulose crosslinking agent esterified to hydroxylic
sites in the cellulose and residues of at least one organic or inorganic sulphonic or sulfinic acids or a
salt e~ riri~,dlion catalyst.
In these aspects of the invention particularly desirable features are as described for the method of
25 the inventiOn
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CPW 50525
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The following Examples illustrate the invention. All parts and pe,~;e"tage are by weight unless
otherwise stated.
Materials
5 BTCA 1 2 3 4-butanett:llacd,l,oxylic acid
OMAi oligo-maleic acid made using benzoyl peroxide as the pol~",erisalion initiator
OMAii oligo-maleic acid made using hydrogen peroxide/acetic anhydride as the pol~""eriaaLion
initiator
MSA methane sulphonic acid
10 Surf Co" " "er- ;al proprield,y do" ,ealic detergent ex Hindustan lever
Test Methods
Wrinkle recovery angles (WRA)
were determined by ATCC Test Method 66-1990; Wrinkle recovery of fabrics: Recovery
angle method. The wrinkle resistance of woven textiles is ~epr~sented by the wrinkle
recovery angles; the greater the WRA the greater the wrinkle resistance of the fabric.
Results are reported in degrees.
Example 1
20 This Example illustrates the use of MSA (Examples 1 a 1 b and 1 c) as a curing catalyst for the
durable press finishing of cotton fabric using BTCA.
Cotton cloth test pieces (10 inches square; ca. 25X25 cm;) were thoroughly wetted by i"""e,aion in a
l,e~l",t:"l bath containing an aqueolJs solution (80 ml) of BTCA (59;6.25%W/V) and MSA
25 (conceril, dtion given in Table 1 ) as curing catalyst at a pH adjusted to 3. The wetted cloth was
passed between the rolls of a wringer and the process repeated twice to give an overall pick up
80% by weight of the dry cloth. The test pieces were stretched on a rack and dried in an air forced
draft oven at 85~C for 5 minutes. The dried test pieces were then treated in an air draft oven at the
l~" "~e, dlures and for the times shown in Table 1 below in which amounts of BTCA and MSA are
30 ex~,ressed as weight % based on dry fabric weight. The treated spec;",ens were rinsed for 5
minutes with 1% Surf solution rinsed with water and air dried and the WRA s) were measured. The
WRA results are included in Table 1 below.
Table 1
Ex BTCA MSA Curing Conditions 'WRA
- No concn. (%) concn (%) Temp.(~C) Time (min)
1 a 6.25 6.25 170 2 248
1 b 6.25 1.25 180 1.5 268
1C 6.25 1.25 190 1 269
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CPW 5.0525
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Example 2
This Example co"")ales MSA ( Example 2) and sodium h~.ophosphi~ (colll,i~dldli~/e Example C2)
as curing catalysts for durable press finishing of cotton fabric with BTCA. The general procedure of
5 Example 1 was followed using the apprupridl~: catalysts and the results are set out in Table 2 below.
Table 2
Ex BTCA Catalyst Curing Conditions WRA
1û No concn. (%) material concn. (%) Temp.(~C) Time (min)
C2 6.25 NaH2PO2 7 5 18û 1.5 271
2 6.25 MSA 1.5 180 2 268-9
Example 3
15 This Example co",pares MSA (Examples 3a 3b and 3c) and sodium hypophosphite (comparative
Example C3) as curing catalysts for durable press finishing of cotton fabric with OMA as the
crosslinking agent Examples 3a and 3b used OMAi and Exdlll e s 3c and 3C OMAii. The general
procedure of Example 1 was followed using the app,uplidle catalysts in the l,~dl",enl bath in the
conce"l, dlions stated in Table 3 below and the results including WRA data are set out in Table 3
20 below.
Table 3
Ex Resin ¦ Catalyst Curing Conditions WRA
No material concn. (%) material concn. (%) Temp.(~C) Time(min)
3a OMAi 5 MSA 5 180 2 250
3b OMAi 5 MSA 1 180 2 252
3c OMAii 5 MSA 5 180 2 244
C3 OMAii 5 NaH2PO2 6 180 1.5 246
Example 3
Cotton cloth specimens were prt:pa,ed by the general procedure of Example 1 using 5% BTCA as
the ll t:bl" ,ent resin and MSA as the curing catalyst at levels of 5% and 1 % by weight on the dry
fabric. The specimens were heat treated at 180~C for 90 seconds. FT-IR spe~ s c ~ ~ s examination
35 of both spec;",ens with particular ~ "lion to the frequency range 1750 to 1720 cm~1 showed
absor,ulions at 1728 cm 1 attributed to the presence of crossl;"ked ester groups.
