Note: Descriptions are shown in the official language in which they were submitted.
1 336996
_ This invention concerns flame retardant compositions and methods
of rendering textile substrates flame retardant with them.
Cotton fabrics can be rendered flame retardant by incorporation
therein of a wide variety of chemicals, some of which provide durable
flame retardance and some of which provide non durable retardance.
Among the latter chemicals are ammonium phosphate and polyphosphate
optionally with added urea. While such compounds are cheap, their
effectiveness is short lived as they are removed by washing with
water. Attempts to increase the durability with such compounds
included high temperature curing at above 150C (see e.g. BP 1504507).
However such high temperature treatments have tended to discolour the
fabric. The curing of the polyphosphate can be associated with
cocuring with a variety of usual fabric treatments agents e.g.
dimethylolethylene urea (see e.g. BP 1069946).
We have discovered flame retardant compositions and processes for
applying them to fabrics of cellulosic materials to give fabrics of
increased durability of flame retardant.
The present invention provides a flame retardant composition
comprising an aqueous medium comprising an ammonium or organic
quaternary ammonium condensed phosphate in an amount of 7-24% (by
weight) and a dispersion of a fluoropolymer. The composition
preferably also contains a carbamic acid derivative eg urea. The
aqueous solution of polyphosphate and if present the carbamic acid may
be in one pack of a 2 pack system, the fluoro dispersion being in the
other pack, the contents of the 2 packs being for mixing to form
compositions of the invention.
The present invention also provides a method of flame retarding a
cellulosic substrate e.g. a cellulosic fabric, which comprises
impregnation thereof with an aqueous composition comprising an
ammonium or organic quaternary ammonium condensed phosphate and a
dispersion of a fluoro polymer, preferably a flame retardant
composition of this invention, drying and curing at 120-170C, the
aqueous composition also comprising a carbamic acid derivative e.g.
urea when the curing is at 147-170C, said derivative being in weight
percentage (expressed as urea) of 50-300% to the weight of condensed
phosphate (expressed as ammonium polyphophate).
1 336996
The polyphosphate salt is made by reaction of a condensed
phosphoric acid with ammonia or an organic amine or quaternary
ammonium hydroxide to give a water soluble product. The condensed
phosphoric acid usually has a mean degree of condensation of more than
3, e.g. 3-30, and usually has a linear branched or cyclic structure.
Preferably the salts contain N and P in an atomic ratio of 0.5-2:1
especially about 1:1. The polyphosphate salt is preferably a mixture
of the ammonium salts of a plurality of polyphosphoric acids, which
mixture has been produced by a process of reacting an aqueous solution
of phosphoric acids containing 80-86% by weight of phosphorus
pentoxide with ammonia or a basic derivative thereof at a temperature
of 15-70C e.g. 15-40C and at a pH of 4-12 such as 5-9 e.g. 6.5-7.5,
or 5 to 12 especially 6 to 8. Ammonium polyphosphate mixtures which
may be used are described in BP 1504507 and may be made as described
therein.
The flame retardant medium preferably also contains a carbamic
acid derivative having 2 amino groups per molecule in a weight
percentage (expressed as urea) to the ammonium polyphosphate
(expressed by weight as ammonium polyphosphate itself) of 0.5%-300%
such as 0.5-50% eg 5-30% such as 7-20% or 10-20% while 50-300% e.g.
50-200% and especially 75-200% or 75-125% are preferred, particularly
for higher temperature curing; generally the higher the cure
temperature the higher the proportion of carbamic acid derivative. The
carbamic acid derivative may be guanidine or dicyandiamide, but is
preferably urea; the weights are expressed as urea but equivalent
weights of the other carbamic acid derivative can be used. The
presence of the carbamic acid derivative reduces any tendency to
discoloration of the fabric after heat curing, especially at high
temperature, and may increase the wet pick up.
The flame retardant medium also contains a dispersion of
fluorocarbon polymer which is preferably capable of being heat cured
at more than 160C eg 160-200C. The fluorocarbon polymer is one
which forms in the flame retardant medium a dispersion which is
usually stable for at least a few days eg at least 2 days; thus fluoro
polymers incompatible with the condensed phosphate solution (with
carbamic acid derivative if present) and forming precipitates on
mixing therewith are avoided. The medium is usually substantially
free of other heat curable water soluble resins or resin precursors
such as formaldehyde condensates with NH compounds such as
3 1 33699b
melamine, urea or ethylene urea. Such aqueous dispersible
fluorocarbon polymers usually have perfluoro alkyl side chains e.g. in
perfluoro-acyl, -sulphonyl or-sulphonamido groups, especially ones
with 3-12 carbon atoms in the perfluoroalkyl group; carboxy groups may
also be present. The fluorocarbon polymers are preferably derived
from acrylic or methacrylic esters of hydroxy compounds containing
perfluoro alkyl groups but can be derived from vinyl esters, vinyl
ethers, allyl esters or thiomethacrylates with perfluoro-alkyl side
chains. Especially preferred polymers are ones containing (N-alkyl N-
perfluoroalkylsulphon-amido) alkylene side chains e.g. 2- (N- propyl
N- perfluorooctylsulphonamido) -ethylene side chains with an acrylate
or methacrylate ester back bone. The polymers may be made only from
monomers containing perfluoro alkyl groups but these monomers may have
been copolymerized with other copolymerizable monomers, particularly
ones fluorine free, e.g. ones containing one or especially two
olefinic double bonds e.g. as in halo butadienes such as 2-chloro 1,3-
butadiene. Olefinic monomer units containing carboxylic acid groups
e.g. acrylic, methacrylic or maleic acid groups may be present in the
polymer. The fluoro polymers are usually sold in the form of aqueous
~1; ~;~s e.g. for fluor~polyrner water r~l lerlt f;rl;~h~ for
fabrics. The polymer dispersion may be non ionic but is preferably
cationic or especially anionic. The fluoropolymer dispersions may
also contain small amounts of water miscible organic solvents e.g.
acetone, MIBK or ethylene glycol.A preferred polymer dispersion is
that sold by 3M Company under the trademark SCOTCHGARD 270 or by Ciba
Geigy Ltd under the trademark SCOTCHGARD FC451. This polymer is
believed to be a copolymer of an 2 (N-alkyl N-perfluoro octylsulphonyl
amido) ethyl acrylate and a comonomer probably 2-chloro -1, 3,-
butadiene. Another preferred fluoropolymer dispersion is that sold
by Hoechst AG under the trademark NUVA FH or NUVA F. Fluoropolymer
dispersions sold by Atochem SA under the trademark FORAPERLE,
especially FORAPERLE 145 and 344, or Texchem UK Ltd Manchester,
England under the trademark TEXFIN CPC may also be used. The weight
percentage of fluorocarbon polymer (solids) to ammonium polyphosphate
is usually 0.1-6% e.g. 1-3% but especially 2-6%.
The flame retardant medium preferably contains 7-18% e.g. 8-15%
such as 9-13% ammonium polyphosphate, and usually 7-18% e.g. 8-15%
such as 9-13% of the carbamic acid derivative e.g. urea, and 0.02-1.5%
4 l 33 6996
e.g. 0.1-1% and especially 0.3-0.8% fluoropolymer. However amounts of
the ammonium polyphosphate of 7-24% such as 10-24% eg 15-24% and
especially 15-23%, and amounts of 0-20% eg 1-20% or 0-15% eg 1-15% or
1-10% such as 1.5-4% of the carbamic acid derivative e.g. urea may be
used. Advantageously the total content of the polyphosphate, carbamic
acid derivative e.g. urea and fluoro polymer in the medium is not more
than 26% e.g. 11-26% or 15-26% especially 20-24%.
The medium can also contain a non rewetting agent e.g. a volatile
wetting agent such as an alcohol or an agent such as is sold by
Warwick Chemicals under the trademark MYKON NRW; amounts of such non
rewetting agents of 1-109./1. are preferred. However if the
substrate, which is to be flame retarded, has already been scoured or
otherwise treated to aid penetration of liquids, then no such agent is
required but one may be present if desired. The aqueous medium is
usually in the absence of extenders or cationic polymers such as
cationic synthetic resin waxes, such as are sold under the trademark
CEROL by Sandoz, and is also usually substantially free of di, tri or
tetra valent metal salts e.g. those of aluminium or zirconium. Some
fluoropolymer dispersions are sold which contain also the extender or
cationic polymer; these should preferably not be used. Fluoropolymer
dispersions sold primarily to provide soil repellency, but not to
provide soil and water repellency, are preferred as the latter tend to
contain the cationic polymer and may be incompatible with the
concentrated polyphosphate solution.
In one preferred embodiment particularly for use with subsequent
curing at 120-147C, the flame retardant composition is an aqueous
medium comprising 7-24% e.g. 10-24% by weight of an ammonium or
organic quaternary ammonium condensed phosphate, 1-10% by weight of
the carbamic acid derivative e.g. urea, the weight percentage of urea
to the polyphosphate being 5-30%, and a dispersed fluoropolymer in
amount of 0.02-1.5% with a total content of the phosphate and urea of
not more that 25%.
In another preferred embodiment particularly for use with
subsequent curing at 147-170C, the flame retardant composition is an
1 3369~6
aqueous medium comprising 8-15% e.g. 9-13% by weight of an ammonium or
organic quaternary ammonium condensed phosphate, 8-15% by weight of
carbamic acid derivative e.g. urea, the weight percentage of urea to
polyphosphate being 50-200%, and a dispersed fluoropolymer in amount
of 0.02-1.5% with a total content of the phosphate and urea of not
more than 25%. In both these embodiments these compositions are
preferably in the absence of cationic water soluble fluorine free
polymers, and advantageously contain the fluoropolymer which has
perfluoroalkylsulphonamide side chains.
The polyphosphate, preferably with the carbamic acid derivative,
may be provided as a concentrated aqueous solution, for subsequent
mixing with the fluoropolymer dispersion before or preferably after
one or both has been diluted to the strength for the impregnation
bath.
The fluoropolymer dispersion is preferably added to the medium
when it is otherwise ready for use for impregnation. The medium is
preferably used for impregnation within a few days though, especially
in the case of anionic fluoropolymer dispersions, the medium may be
stable for at least 1 week e.g. at least l month.
The aqueous medium may also contain other textile auxiliary
agents of nature and in amount such that they are compatible with the
other components of the medium, and are not significantly affected by
the heat cure treatment e.g. to cause discoloration or loss of effect.
Examples of such agents are softening or conditioning agents, which
may be cationic, anionic, non ionic, amphoteric or reactive and
usually contain at least 1 and often 2 alkyl chains of at least 10
carbon atoms. Examples of cationic softening agents are fatty
quaternary ammonium salts, amino esters and amino amides and
quaternary N acyl N polyoxyalkylene polyamines. Examples of anionic
softening agents are fatty acid salts, soaps, sulphonated fats and
oils, fatty alkyl sulphates and fatty acid condensation products,
sulphosuccinates and sulphosuccinamates. Examples of amphoteric
agents are alkyl imidazolines and betaines and salts thereof e.g.
methosulphate, acyl amido betaines, acyl polyamines, amine oxides,
substituted amino acids and sulpho betaines. Examples of non ionic
-
softening agents are poly alkylene glycol ethers a6nd9 e9s~ers and other
polyoxyalkylene condensation products, and paraffin wax or
polyethylene wax, these latter two being used in aqueous dispersion or
emulsion, with non ionic, cationic or anionic, but especially
amphoteric dispersing agents. Examples of reactive softening agents
are N-methylol derivatives of fatty acid amides e.g. N-methylol
stearamide or N methylol derivatives of fatty acid condensates with
urea. The softening agent as such or as dispersion thereof may be
used in amount of 0.01-5% e.g. 0.5-3% by weight of the total aqueous
impregnation medium. The presence of the softening agent can enable
the heat cure process to produce a treated fabric having improved
flame retardance and with other properties e.g. strength especially
tear strength and colour substantially the same as those of the
untreated fabric; the strength may even be improved.
The substrates to which the medium is applied may be woven or non
woven. They are cellulosic based substrates e.g. textile fabrics or
filaments, such as of cotton, linen, jute, hessian or regenerated
cellulosic materials, such as rayon or viscose, but can also be
paper, cardboard or wallpaper. The substrate can also be based on
cellulosic material and other fibres coblendable or mixable therewith
e.g. polyester or nylon, acrylics, acetate, polypropylene, silk or
wool; these blends or mixtures of fibres may contain at least 50% of
the cellulosic material e.g. 70-100% such as 50-80% thereof.
Fabric weights can be 50-1000 g/m2, e.g. 80-500g/m2. The fabric
may be of pile or plain construction. The fabric may be plain or
undyed or may be dyed or printed, especially with white or pastel
shades. The fabric before impregnation is usually free of dirt,
sizes, natural waxes and applied finishes though may contain an
optical brightening agent.
The flame retardant medium usually at pH 5-8 e.g. 5.5-7.5 is
applied to the substrate by conventional procedures e.g. padding,
soaking or spraying usually to a wet pick up of 50-150% e.g. 60-100%
The total solids add-on before drying and after squeezing off surplus
liquid is usually 10-35% e.g. 10-20% or 13-25% (based on the dry
initial weight of the fabric) After impregnation the substrate is
then dried e.g. for textile substrates at 80-120C for 2 to 40 minutes
7 1 336996
e.g. 2-10 minutes. The drying may be performed in any conventional
drier e.g. a forced air drier or stenter. The solids pick^up after
drying is usually 8-25% such as 10-20% (based on the original weight
of the fabric).
The dried substrate is then cured eg by heating at a temperature
of 120-170C such as 130-170C e.g. 140-170C or 147-170C for 6 to
0.5 or 5-0.5 minutes, the combination of longer times and higher
temperature being avoided to decrease any tendency to discoloration.
Preferred temperatures, especially with high proportions of carbamic
acid derivative to polyphosphate, are 147-165C such as 147-160C or
147-155C for 6-0.5 e.g. 5-2 minutes. To minimise risk of any colour
formation especially with low proportions of carbamic acid derivative
to polyphosphate the dried substrate is preferably cured by heating at
120-147C for 6 to 0.5 minutes, the combination of longer times and
higher temperature being avoided to decrease any tendency to
discoloration. These preferred temperatures are 120-138C such as
124-142C or 128-138C for 6-0.5 e.g. 6-1.5 minutes while at
temperatures of 138-147C times of 3.5-0.5 minutes such as 138-142C
or 142-147C for 3.5-0.5 minutes can be used. Curing at 130-140C for
4-2 eg 3.5-2.5 minutes is preferred.
The curing at 147-170C with a higher proportion of carbamic acid
derivative to polyphosphates usually has a higher cure efficiency than
the lower temperature cure which has a higher proportion of
polyphosphates and higher amount thereof in the impregnation bath, but
the latter has a reduced tendency to discoloration especially with
white or pastel fabrics. The presence of the fluoropolymer increases
the durability to soaking of the fabric cured at 120-147C or
147-170C.
The curing which is usually continuous may be performed by
radiant e.g. infra red heating or heating by injection of steam and/or
hot air through the substrate, or by contact of the substrate with
heated metal drums in a vertical stack, but preferably the curing is
by heating from impact of hot air on the surface of the substrate,
preferably on both surfaces to ensure uniformity of heating. Thus
preferably the substrate is passed continuously on a stenter through a
thermostated oven in which heated air flows are passed on to the top
and bottom surfaces of the substrate. The stenter gives the most
1 3J6~96
uniform curing with minimum scorching. In the case of the stenter
oven, the cure temperature of the substrate is essentially the same as
that of the heated air flow. Usually at the end of the curing the
substrate is cooled rapidly by passing or drawing cool air through it.
The cured fabric as finished usually has a solids content of
6-25% such as 8-20% and usually contains 0.5-5%P e.g. such as 0.5-4%P
preferably 1-3%P or 2-4%P. The fabric as finished has a reduced
flammability compared to the untreated substrate and can pass the BS
5852 test with ignition sources O and 1. The fabric after leaching
once in hard water at 40C according to BS 5651 without final ironing
usually has a solids content of 3-10% e.g. 4-9%, a % P content of
0.4-3% preferably 0.9-3% eg 1-3%P and can pass the flammability test
of BS 5852 Part 1 with ignition sources O and 1. The reduced
flammability finish is usually durable for 1-3 washes in soft water at
74C while some fire retardant effect is retained thereafter. The
fabric as finished usually has a handle not significantly changed from
that of the untrea~ed fabric, and usually has a colour not
significantly changed from that of the untreated fabric. The fabric
as finished usually has some degree of water and oil repellency
but ~ may be su~L~.Lially removed on one soaking at 40C in
water cn~;n;n~ w~t~;n~ agent. The synergistic combination of (i)
fluoropolymer and (ii) condensed phosphate (with carbamic acid
derivative if present) can give substrates of improved durability of
flammability not possessed by substrates from (i) or (ii) alone.
The invention is illustrated in the following Examples. In Ex.
1-11, 13 and 14 the fluoropolymer was used as a 23% aqueous emulsion
of fluoropolymer with a slight cationic character sold by 3M under the
Trademark SCOTCHGARD FC 208 or Ciba Geigy under the Trademark
SCOTCHGARD FC451. This fluoropolymer is believed to be a copolymer
of 2 (N-propyl N- perfluoro octylsulphonyl amido) ethyl acrylate and
2-chloro- 1, 3- butadiene. In Ex 12 the fluoropolymer was an aqueous
fluorocopolymer dispersion which was anionic, has a pH of 7.5-8.5 and
was sold by Hoechst AG under the trademark NUVA FH and is believed to
contain carboxyl and perfluoroalkyl groups. In Ex 15, 16, 19, 20, 23,
24 and Comp. Ex A-D the fluoropolymer was an aqueous acrylic
fluoropolymer dispersion sold by Atochem S.A. under the trademark
FORAPERLE 145; it is slightly cationic, has pH 4.5 + 0.5 and is
9 1 336996
believed to contain perfluoroalkyl, carboxyl and sulphonamido groups.
In Ex 17, 18, 21 and 22, the fluoropolymer was an aqueous
fluoropolymer dispersion which is slightly cationic, has pH 6-8 and is
sold by Texchem UK Ltd, Manchester, England under the trademark Texfin
CPC; it is believed to contain perfluoroalkyl and carboxyl groups.
The ammonium polyphosphate used in all the Examples was made by
reacting polyphosphoric acid of 83-85% P205 with ammonia according to
BP 1504507, to produce a product which was adjusted, to give an
solution at pH6.2 containing 45% solids, 30% P205 and a specific
gravity of 1.36.
In each case the same general procedure was adopted. The aqueous
solution of the ammonium polyphosphate and urea was made and after
dilution with water if desired, was mixed with stirring with the
fluoropolymer emulsion, in amount (by weight of emulsion based on the
of total weight of solution and emulsion), of 2% for Ex1-11, 13 -
22 and 1.5% for Ex 12, and also in Ex1-13 0.5% of a non rewetting
agent sold under the trademark MYKON NRW to give aqueous media
containing the ammonium polyphosphate fluoropolymer and urea. The
aqueous medium obtained was stable, but was preferably used without
undue delay. The fabric was impregnated with the aqueous medium and
squeezed and then the impregnated fabric dried at 90-100C or 110C in
a forced air drier or stenter. Portions of the dried fabric were then
moved on a stenter slowly but continuously through a thermostated
stenter oven provided with heated air flows impinging on the fabric
from top and bottom. The fabric was weighed after drying and after
curing. The cured fabric was then tested according to the test of BS
5852 Part 1 with ignition sources 0 and 1 for flammability as finished
and after leach once in hard water at 40C according to BS 5651 Part 1
without final ironing.
Some finished fabrics were also submitted to a dry cleaning test
with 3 commercial dry cleaning cycles in a charged solvent system
charged with 10% water.
Some fabrics were also tested for oil and water repellency
according to AATCC 118 and BS 3702 respectively and assessed for
colour.
lo 1 ~3699~
Example l
The aqueous ammonium polyphosphate solution (94 parts) was mixed
with urea (6 parts) and the mixture obtained diluted with water (122
parts) and then the fluoropolymer emulsion and NRW agent added to give
the impregnation medium. The medium was applied in a pad mangle to a
floral print cotton fabric of 230 g/m2 and also to prescoured colour
woven orange dyed cotton fabric of 410 g/m2, with wet pick-ups of 71%,
and 81.5% respectively. The impregnated fabrics were then dried on a
stenter at 100C for 3.5 minutes and then cured at 135C for 2.5
minutes. The floral and orange fabrics as finished contained 3.19%
and 3.53%P respectively. All the fabrics as finished and after one
leach in hard water passed the BS 5852 test with ignition sources 0
and 1. The floral and orange fabrics were also submitted to the BS
5438 test 2 flammability test with char lengths in mm. as shown in the
Table below. After the hard water leach the floral and orange fabrics
contained 0.99% and 1.43% P respectively.
Char Length
Fabric I As Finished I Leached I Dry Cleaned
Floral 1 108 1 124 1 92
Orange 1 84 1 74 1 75
Other Properties were as follows:-
¦ Oil Repellency ¦ Water Repellency ¦
Fabric ¦ Finish ¦ AATCC 118 ¦ BS 3702
Floral- ¦ Untreated ¦ NT I NT
print ¦ Treated ¦ 3 ¦ 70
Orange ¦Untreated ¦ NT ¦ NT
¦Treated ¦ 6 ¦ 70
NT - means not tested.
11 ~ 336996
In the treated floral fabric, there were essentially no colour changes
in the white or coloured parts of the floral print compared to those
in the untreated fabric.
Example 2
The process of Ex 1 was repeated with a variety of fabrics of
different weights and styles and tests for flammability performed
according to BS 5852 ignition sources 0 and 1. In all cases the tests
were passed. The fabrics were:-
(1) 100% cotton, plain, velvet, print or colour woven of weights inthe range 120-410 gm~2.
(2) Cotton blends with linen (48:52), viscose (46:54) (55:45) or
viscose/nylon (25:72:3) print, velour or colour woven of 330-540
gm~2 weight.
(3) Cotton blends with polyester (53:47) colour woven of 300 gm~2.
(4) Mixed velvet fabrics with 63 cotton, 37 acrylic pile and 47
cotton 28 acrylic 25 polyester base of weight 540 gm~2, and with
100 viscose pile and 83 viscose, 10 cotton, 7 polyester base of
weight 750 gm~2.
ExamPles 3-8
The process of Ex 1 was repeated, with the following changes.
In these experiments the fabric was scoured cotton fabric of 220 g/m2
fabric weight dyed red.
-
- 12 1 336996
Example 3 4 5 6 7 8
Cure temp C 130 130 130 130 140 140
Time minutes 2 3 4 5 2 3
% wet pick up 81.7 81.5 81.8 81.6 80.8 81.2
% dry solid 15.8 16.2 16.2 15.8 15.7 16.2
pick up
% Solids after 15.1 15.9 15.6 15.5 15.7 14.9
cure
% solids after 5.7 7.8 7.0 7.8 7.0 7.6
1 leach
All the treated fabric after 1 leach passed the BS5852 ignition test
with sources 0 and 1, and there was no significant colour change
compared to the untreated fabric.
Examples 9 and 10
The process of Ex 1 was repeated with a white cotton fabric of
270 9/m2 which did not contain optical brightening agent. The cure
conditions at 135C were 3 min (Ex 9) and 3.5 min (Ex 10). The
fabrics as finished and after one leach passed the BS5852 test with
ignition sources 0 and 1. The fabrics as finished and after one leach
showed no significant colour change compared to the fabrics before
treatment.
ExamPle 11
The process of Ex 1 was repeated with changes to the aqueous medium,
the fabric and cure conditions. The aqueous medium was made by mixing
the aqueous ammonium polyphosphate solution (59 parts), urea (27 parts
and water (154 parts), followed by the fluoropolymer emulsion and NRW.
13 1 3 3 6 9 9b
The fabric was a white cotton drill fabric of 268 g/m2. The fabric
was padded to about 75% wet pick up, the drying was 2 minutes at 100C
and the cure conditions 2.5 minutes at 145C. The fabric as finished
contained 2.19%P, and the fabric after one leach contained 1.19%P.
The fabric after the leach had a char length of 128 mm when tested by
BS5438 test 2. The fabric as finished and after one leach showed no
significant colour change compared to the fabric before treatment.
Example 12
The process of Ex 1 was repeated with the NUVA fluoropolymer
emulsion in amount of 1.5%. The impregnation medium was stable for at
least 2 months at room temperature. The fabric impregnated was a red
dyed cotton fabric of 220 9/m2 and the wet pick up was 72.5%. After
drying and curing as in Exl, the fabric had a total solids add-on as
finished of 15.8% and a total solids add-on after one leach of 5.6%.
The fabric as finished and after on each passed the BS 5852 test with
ignition sources 0 and 1. The fabric as finished and after the leach
showed no significant colour change compared to the fabric before
treatment.
Example 13
The process of Ex 1 was repeated with 3111 cotton drill fabric of
3009/m2 and with and without the presence of 2% (based on the total
weight of the impregnation medium) of a softening agent, which is an
aqueous amphoteric dispersion of an aliphatic hydrocarbon, probably a
paraffin wax or polyethylene wax, sold by Sandoz under the trade mark
SANDOLUBE NV. The cure conditions were 135C for 3 minutes. The
cured fabric was tested for flammability and tested for tear strength
in the warp and weft directions according to Elmendorf. The cured
fabric as finished and after one leach passed the BS 5852 test with
ignition sources 0 and 1, and showed no significant colour difference
compared to the untreated fabric. The results of the tear strength
work were as follows:-
14 1 3369~6
Tear Strength g.
Fabric ¦ Warp ¦ Weft
Untreated ¦ 3162 ¦ 4452
Treated
Without SANDOLUBE NV ¦ 3174 ¦ 3853
With SANDOLUBE NV ¦ 5414 ¦ 5619
Example 14
The aqueous ammonium polyphosphate solution (59 parts) and urea(27 parts) and water (154 parts) were mixed and then the fluoropolymer
emulsion and NRW added to give the impregnation medium. The medium
was applied in a pad mangle to a floral print cotton fabric of 230
g/m2 and also to a prescoured colour woven cotton fabric of 410 g/m2,
dyed brown, with wet pick-ups of 71%, and 96.5% respectively. The
impregnated fabrics were then dried on a stenter at 100C for 3.5
minutes and then cured at 150C for 3 minutes. The fabrics as
finished contained 1.98 and 2.35% P respectively. All the fabrics as
finished, after one leach in hard water and after dry cleaning passed
the BS 5852 test with ignition sources 0 and 1. The floral and brown
fabrics as finished, after one leach in hard water and after dry
cleaning were also submitted to the BS 5438 test 2 flammability test
with char lengths in mm. as shown in the Table below. After the hard
water leach the fabrics contained 1.27 and 1.83%P respectively.
Char Length Data
Fabric I As Finished I Leached I Dry Cleaned
Floral 1 98 1 102 1 91
Brown 1 71 1 73 1 65
l 336996
Other Properties were as follows:-
-
I Oil Repellency ¦ Water Repellency ¦
Fabric I Finish I AATCC 118 ¦ BS 3702
Floral- IUntreated¦ NT I NT
print ITreated ¦ 5 1 70
Orange IUntreated¦ NT I NT
ITreated ¦ 5 ¦ 70
NT - means not tested.
The colours of treated fabrics were not significantly different from
those of the untreated fabrics.
Example 15. 16, 17 18
The process of Ex 1 was repeated with a floral print plain weave
cotton fabric of 225g/m2 and two different fluorocarbon polymer
emulsions, one sold under the trademark FORAPERLE 145 (Ex 15, 16) and
one sold under the trademark TEXFIN CPC (Ex 16, 17) in each case with
(Ex 15, 17) and without (Ex 16,18) the softening agent used in Ex 13.
The impregnation bath was made from 34.8 parts of the ammonium
polyphosphate solution, 2.2 parts of urea and 59.5 parts of water,
with 2 parts of the fluoropolymer emulsion and with 1.5 parts of the
softening agent or 1.5 parts of extra water. The fabric wet pick up
was 76% and after drying at 110CC for 1 min, the dried fabric was
baked at 135C for 3 min. The finished fabrics were soaked in water
according to the BS 5651 test and after drying were submitted to the
BS 5438 test 2 flammability test. The finished fabrics were also
tested for Tensile and Tear Strength according to Elmendorf and water
and oil repellency. The results were as follows:-
16 l 33699~
Example Un- 15 16 17 18
treated
Tensile strength, warp, N/5mm 660 650 657 657 671
" " weft, N/50mm 647 639 644 638 628
Tear strenght, warp, g 3349 3360 2679 3349 2740
" " weft, 9 2410 2517 1920 2482 1860
Water repellency BS3702 NT 80 80 70 70
Oil repellency AATCC118 NT 7 6 6 6
Flammability test after
soaking, char length mm NT 105 100 105 110
NT = Not tested
N/50mm means Newtons per 50mm wide fabric
ExamPle 19-22
The process of Ex 14 was repeated with the same cotton fabric and
fluorocarbonpolymer emulsions used in Ex 15-18, the FORAPERLE 145
emulsion being used in Ex 19 and 20, and the TEXFIN CPC emulsion used
in Ex 21 and 22, and with (Ex 19, 21) and without (Ex 20, 22) the
softening agents used in Ex 13. The impregnation bath was made from
20.6 parts of the ammonium polyphosphate solution, 9.28 parts of urea,
2 parts of the fluorocarbon polymer emulsion, 61.5 parts of water and
1.5 parts of the softening agent (or 1.5 parts of extra water in Ex
20, 22). The fabric wet pick up was 76% and after drying at 110C for
l min, the dried fabric was baked at 150C for 3 min. The finished
fabrics were soaked in water according to BS 5651 test and after
drying were submitted to the BS 5438 test 2 flammability test. The
finished fabrics were also tested for tensile and tear strength and
water and oil repellency. The results were as follows:
17 1 33 69 9 6
Example Un- 19 20 21 22 treated
Tensile strength, warp, N/50mm 660 621 614 606 626
" " weft, N/50mm 647 587 582 597 574
Tear strength, warp, 9 3349 3306 2344 3215 2411
" " weft, 9 2410 2304 1660 2217 1688
Water repellency BS3702 NT 90 90 80 80
Oil repellency AATCC118 NT 7 7 6 6
Flammability test NT 71 82 75 88
after soaking, char length mm
NT = Not tested
Example 23 and Comparative Examples A and B
Fabrics treated by a method of the invention (for Ex 23), were
compared for colour with those of fabrics treated by different methods
using curing conditions described in Examples 1 and 2 of BP1504507
(for Ex A and B). The fabric was that used in Ex 19. The
impregnation bath and method for Ex 23 where the same as in Ex 19,
while the comparative baths and processes for Comparative Ex A and B
involved ammonium poylphosphate and urea in concentrations given in Ex
1 of BP1504507 but with wet pick ups, and drying conditions as in Ex
20 and cure for 7 min at 150C (Comp Ex A) and cure for 5 min at 160C
(Comp. Ex B). The cured fabrics were tested for colour on a "1-5 grey
scale" compared to the untreated fabric, 5 denoting little or no shade
change and 1 denoting maximum change. The results were as follows: Ex
23, shade 4/5, Comp Ex A shade 2, and Comp Ex B shade 1.
Example 24 and ComParative Ex C and D
Fabrics treated by a method of the invention (Ex 24) with an aqueous
medium containing both (i) ammonium polyphosphate and urea and (ii)
fluorocarbon polymer were compared for flammability and water
repellency before and after soaking with corresponding fabrics having
been treated with aqueous media containing either (i) or (ii) (Comp C
18 l 336996
and D respectively). The fabric was as in Ex l9. The method in Ex 24
was as in Ex 20, while that in Comp Ex C was the same as in Ex20 but
without the fluoropolymer and in Comp Ex D involved impregnation of
the fabric with a 2% dispersion of the fluoropolymer emulsion and
drying, followed by baking for 3 min at 150C. The fabrics were
tested for flammability according to BS 5438 and water repellency
according to BS 3702. The soaking involved immersion of the fabrics
for 30 min in a bath at 40C of water containing 5g/l wetting agent.
After the soaking the fabrics were dried and retested. The results
were as follows.
Example Char Length mm Water Repellency
24 73 100
24 after~soak 77 50
C 73
C after soak 103
D - lO0
D after soak - 50
NB The water repellency scale goes from 100 (best) to 0.
