FABRIC CONDITIONING COMPOSITION

COMPOSITION POUR LE TRAITEMENT DES TISSUS

English Abstract

Fabric softening compositions containing more than 2% of a cationic fabric softener, an amphoteric deposition polymer having a molecular weight greater than 1000 and being substantially free from anionic detergent active, are disclosed. The polymer acts as a deposition aid to reduce the adverse effect of anionic surfactant from the wash cycle being carried into the rinse cycle and forming a complex with the softener.

French Abstract

L'invention concerne des compositions pour l'assouplissement des tissus contenant plus de 2 % d'assouplissant de tissu cationique, un polymère de dépôt amphotérique ayant un poids moléculaire de plus de 1 000 et étant sensiblement exempt de détergent anionique actif. Le polymère sert d'aide au dépôt pour réduire l'effet négatif de l'agent de surface anionique du cycle de lavage porté dans le cycle de rinçage et formant un complexe avec l'assouplissant.

Claims

-19-
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A fabric softening composition comprising more than 2%
of a cationic fabric softener and being substantially
free from anionic detergent active, characterised in
that the composition contains an amphoteric deposition
polymer, said polymer having
i) positively and negatively charged units
ii) a molecular weight greater than 1,000
iii) a neutral unit or units having a molecular weight
no greater than the combined molecular weight of
the charged units.
2. The composition according to claim 1 in which the
amphoteric deposition polymer has a structure in which
said positively and negatively charged units comprise:
a) a positively charged unit derived from a monomer
salt wherein the cation of the salt has a formula:
<IMG>
wherein R1 and R2 are independently selected from
C1-C4 alkyl groups; R3 is a C1-C4 alkyl group or a
C2-C4 alkenyl group and R4 is a C2-C4 alkenyl group,
a C1-C4alkyl acrylate, a C1-C4 alkyl methacrylate,
a C1-C4 alkyl methacrylamide, and a C1-C4 alkyl
acrylamide;

-20-
b) a negatively charged unit having a carboxylate
group derived from a monomer having a formula:
<IMG>
wherein R5, R6, R7 and R8 are independently selected
from H1 or a C1-C4 alkyl group and a(CH2)n COOR8 in
which n is an integer between 0 and 6.
3. The composition according to claim 2 in which
a) the positively charged unit is derived from a
monomer cation of the following formula
R1 R2 N+ (CH2-CH=CH2)2
and
b) the negatively charged unit comprises acrylate
and/or methacrylate.
4. The composition according to claim 3 in which the
neutral unit is an hydroxy propyl acrylate derivative.
5. The composition according to claim 1, 2 or 3 in
which the amphoteric deposition polymer is present in an
amount from 0.1 to 5% by weight.
6. The composition according to one of claims 1 to 5 in
which the weight ratio of amphoteric deposition agent
to cationic fabric softener lies in the range from 1:4
to 1:50.

-21-
7. The composition according to any one of claims 1 to 6
having a pH range from 5 to 8 measured at 1% dilution in
water.
8. Use of an amphoteric deposition polymer having a
molecular weight of at least 1000 in a fabric softening
composition as a deposition aid, the polymer having
i) positively and negatively charged units
ii) a molecular weight greater than 1,000
iii) a neutral unit or units having a molecular weight
no greater than the combined molecular weight of
the charged units.
9. Use of the amphoteric deposition polymer according to
claim 8 in which said positively and negatively charged
units comprise;
a) a positively charged unit derived from a monomer
salt wherein the cation of the salt has a formula:
<IMG>
wherein R1 and R2 are independently selected from
C1-C4 alkyl groups; R3 is a C1-C4 alkyl group or a
C2-C4 alkenyl group and R4 is a C2-C4 alkenyl group,
a C1-C4 alkyl acrylate, a C1-C4 alkyl methacrylate, a
C1-C4 alkyl methacrylamide, and a C1-C4 alkyl
acrylamide;

-22-
b) a negatively charged unit having a carboxylate
group derived from a monomer having a formula:
<IMG>
wherein R5, R6, R7 and R8 are independently selected from
H1 or a C1-C4 alkyl group and a (CH2)n COOR8 in which n is
an integer between 0 and 6.

Description

2177125
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FABRIC CONDITIONING COMPOSITION
This invention relates to a fabric conditioning composition
which is substantially free of anionic detergent and is
particularly suitable for conditioning (e.g. softening)
fabrics in the rinse step of a fabric laundering process.
The invention particularly relates to conditioning in the
presence of anionic detergent carried over from the washing
step of the fabric laundering process.
It is known to add fabric conditioning agents comprising
cationic materials such as quaternary ammonium salts or
imidazolinium salts to the rinse step of a fabric laundering
process. As a result of the use of anionic materials for
soil removal from fabrics in the preceding wash step, anionic
materials find their way into the rinse water. This problem
is common in countries where water is used sparingly and will
become more common as machine manufacturers move to lower
water consumption machines for increased energy efficiency.
Anionic 'carry-over' can have disadvantageous effects on
cationic fabric softening materials added to the rinse water.
The anionic and cationic materials react together to form a
complex and thereby reduce the quantity of cationic charged
material available for deposition on the wash load.
Several proposals have been made to solve this problem.
GB 2039 556 discloses the use of a soluble monoalkyl
quaternary ammonium salt in conjunction with the more usual
dialkyl softening quaternary. Unfortunately the benefit of
this solution is small relative to the increased formulation
cost.

2177125
C.`39
- 2 -
A second solution, which also seeks to provide increased
cationic charge to neutralise the anionic, is described in
US 4179382. This patent specification suggests that use of
cationic polymers which provide a high density of positive
charge will improve softening performance. The problem with
such polymers is that they give rise to product stability
problems when used at high enough levels to be of practical
use and they are uneconomic.
EP 063 899 suggests a different approach. An inorganic
polymer such as aluminium chlorohydrate precipitates metal
hydroxide or hydrated oxide at a pH of less than 7.5. The
=~
precipitate is said to facilitate deposition of the softener.
' The disadvantage of this solution is that the inorganic
polymer has to be used at very high levels (12.5 to 37.5% of
the cationic level) to be effective. This makes it
unattractive from an economic and an environmental viewpoint.
GB 2 195 652 teaches that anionic/cationic complexes provide
a softening effect when deposited on fabric. The problem
with such complexes is that they need to be preformed and
administered in special ways if grease spot formation is to
be avoided. The extent of softening is also rather limited.
EP 426304 describes a rinse conditioner containing
polysiloxane, a cellulose ether and an optional fabric
softener material. Soap is the preferred fabric softener
material and is deposited with the polysiloxane to give the
softening effect.
EP 276 999 discloses a fabric softening composition which
comprises of a cationic fabric softener and cellulose ether
as a deposition aid to mitigate the effects of anionic carry
over from the main wash. However cellulose ethers are only

CA 02177125 2007-10-02
3 -
ettective as a deposition aid when there is a high level of
anionic carry over.
The advantage of the present invention is that it may be used
in rinse steps where there is moderate anionic detergent
active resulting from carry-over from the wash steps. Thus
the formulations of the invention perfume and soften the wash
load, even when anionic carryover occurs.
The present invention provides a fabric softening composition
comprising more than 2% of a cationic fabric softener and
being substantially free from anionic detergent active,
characterised in that the composition contains an amphoteric
deposition polymer, said polymer having
i) positive and negative charged units
ii) a molecular weight greater than 1,000
iii) a neutral unit or units
having a molecular weight no greater than t;.`:3e
combined molecular weight of the charged units.
The amphoteric polymer preferably has a molecular weight of
at least 2000 and desirably at least 6000.
The invention also provides for the use of an amphoteric
polymer having a molecular weight of at least 1000 preferably
at least 2000 and desirably at least 6000 in a fabric
softening composition as a deposition aid.
It is preferred if the amphoteric deposition polymer has a
structure comprising the following units:

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a) a positively charged unit derivable from a monomer
salt wherein the cation of the salt has a formula:
R4
R1 - N` - R2
R3
wherein Rl and R2 are independently selected from C1-C4
alkyl groups; R3 is a C1-C4 alkyl group or a C2-C4
alkenyl group and R4 is a C2-C4 alkenyl group, a C1-C4
alkyl acrylate, a C1-C4 alkyl methacrylate, a C1-C4
alkyl methacrylamide, or a C1-C4 alkyl acrylamide;
b) a negatively charged unit having a carboxylate group
derivable from a monomer having a formula:
R5 R6
1
C = C
R, ( CH2 ) nCOzRB
wherein R5, R6, R7 and R. are independently selected from Hl or
a C1-C4 alkyl group or a(CHZ ) nCOORB in which n is an integer
between 0 and 6.
Where the monomer for b) comprises 2 or more carboxyl groups,
the ring closed condensation product may also be employed as
the monomer. For example maleic acid (where n is 0 R5,R6 and
R8 are H, and R, is -COZH,) may be present as maleic anhydride
depending on the pH of the reaction mixture.

C_.59 2177125
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it is preferred if charged unit (a) is derived from the
monomer cation selected from the group consisting of
trimethyl ammonium(ethyl methacrylate), trimethyl ammonium
(ethyl acrylate) and trimethyl ammonium propyl
methacrylamide. It is especially preferred if the monomer
cation has the following formula:
( CH2=CH-CH2 ) Z-N- ( CH3 ) 2
Other suitable monomer cations include those where R4 is of
the general formula
R9
CH2 = C
1
0 = C - X - Rlo
wherein R9 is H or CH31 Rlo is a C2_6 preferably C2 to Cõ
alkylene group and X is 0 or NR9.
The monomer cation thus contains at least one ethylenically
unsaturated moiety. This moiety combines with other monomers
upon polymerisation. Where the cation contains only one such
moiety the quaternary nitrogen group is present in the
polymer as a pendant substituent on the polymer chain. Where
the cation contains two or more ethylenically unsaturated
moieties as in, for example a dimethyldiallyl ammonium
cation, formation of a heterocyclic ring may occur during
polymerisation. For example (CH2=CH-CH2) 2N` (CH3) 2, upon
polymerisation is believed to form a repeating monomer unit
of the following structure:
CHz - CH - CH2
( CH3 ) 2N~ ~ I
CH2 - CH - CH2

2177125
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It is preferred if the negatively charged unit (b) is
selected from the group consisting of of acids, esters and
salts of methacrylate, beta carboxyl acrylate, maleate,
itaconate and fumarate. Especially preferred as the
negatively charged unit is acrylate.
The units of similar charge may be grouped together to
provide a block copolymer or randomly spaced to provide a
random copolymer as desired.
It is advantageous if the ratio of positively charged units
to negatively charged units within the amphoteric polymer is
in the range from 1:4 to 4:1. It is preferred if this ratio
of positively charged units to negatively charged units is in
the range of 1:2 to 3:1. In order to provide an optimum
combination of performance and stability characteristics.
Suitably the amphoteric polymers may be any molecular weight.
Low molecular weight polymers have a lower viscosity which
generally may be employed to improve the processability of
the composition whilst polymers having a higher molecular
weight may be desirable in order to provide a thickening
effect as desired. Suitably the molecular weight of the
amphoteric.polymer is above 6000 and may be above 25,000,
conveniently in the range from 40,000 to 1,000,000 and
especially from 100,000 to 500,000.
The amphoteric deposition polymer may further comprises a
neutral unit. If present the neutral unit has a molecular
weight no greater than the total molecular weight of the
charged units. Suitably the monomer of the neutral unit
comprises an alkyl, preferably C1 to C4 (meth)acrylate. In
this cases the carboxyl group is present in the neutral unit
a carboxylic ester. The alkyl moiety optionally has a

CA 02177125 2007-10-02
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hydroxyl substituent. An example of a suitable neutral unit
is an hydroxy propyl acrylate derivative.
The amphoteric polymer is preferably present in the product
in an amount 0.05 - 2% by weight and most preferably 0.1 - 1%
by weight.
Preferably the composition contains more than 2%, more
preferably more than 3.5% cationic fabric softener and most
preferably more than 5% cationic fabric softener.
Preferably the weight ratio of deposition agent to cationic
fabric softener lies in the range 1:4 to 1:100, more
preferably 1:4 to 1:50 preferably 1:10 to 1:45.
The cationic fabric softener may be any suitable cationic
surfactant which has fabric softening properties. Suitable
fabric softening materials and mixtu.r.,:~s thereof are well
cnown in the art, particularly from "Surface Active Agents
2~) And Detergents", Anthony M. Schwartz et al, first published
in 1949 (Interscience Pubs., New York) and reprinted in 1958
and 1977 (latterly by Robert E. Krieger Publishing Co.),
"Synthetic Detergents", Milwidsky and Davidson, published in
1972 (Chem. Rubber Co., Cleveland, Ohio), and "Household and
r_ndustrial fabric Conditioners", Noyes Data Corporation,
-1~ublished in 1980.
~ationic materials which are most useful are quaternary
ammonium salts, wherein at least one higher molecular weight
group and two or three lower molecular weight groups are
linked to a common nitrogen atom to produce a cation and
~,;rherein the electrically balancing anion is a halide, acetate
or lower alkosulphate ion, such as chloride or methosulphate.
-he higher molecular weight substituent on the nitrogen is
preferably a higher alkyl group, containing 12 to 18 or 20
carbon atoms, such as coco-alkyl, tallowalkyl, hydrogenated
tallowalkyl or substituted higher alkyl, and the lower
:_olecular weight substituents are preferably l--wer alkyl of

C._,59 2177125
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to 4 carbon atoms, such as methyl or ethyl, or substituted
lower alkyl. One or more of the said lower molecular weight
substituents may include an aryl moiety or may be replaced by
an aryl, such as benzyl, phenyl or other suitable
substituent. A preferred quaternary ammonium salt is a di-
higher alkyl, di-lower alkyl ammonium halide, such as di-
tallowalkyl dimethyl ammonium chloride or di-hydrogenated
tallowalkyl dimethyl ammonium chloride, and other quaternary
ammonium chlorides will also usually be preferred. For
biodegradability the higher molecular weight group may be
linked to the nitrogen atom via an ester group. Examples of
suitable ester linked quaternary ammonium-compounds are
listed in EP 0 239 910-A (P&G)
In addition to the cationic compounds previously mentioned,
other suitable cationic surfactants include the imidazolinium
salts, such as 2-heptadecyl-l-methyl-l-[(2-stearoylamido)
ethyl]-imidazolinium chloride; the corresponding methyl
sulphate compound; 2-methyl-l-(2-hydroxyethyl)-1-benzyl
imidazolinium chloride; 2-coco-l-(2-hydroxyethyl)-1-benzyl
imidazolinium chloride;2-coco-l-(2-hydroxyethyl)-1-
octadecenyl imidazolinium chloride; 2-heptadecenyl-l-(2-
hydroxyethyl)-1-(4-chlorobutyl) imidazolinium chloride; and
2-heptadecyl-l-(hydroxyethyl)-1-octadecyl imidazolinium ethyl
sulphate. Generally, the imidazolinium salts of preference
will be halides (preferably chlorides) and lower
alkylsulphates (alkosulphates).
Others of the mentioned quaternary ammonium salts and
imidazolinium salts having fabric softening properties may
also be employed in the present invention and various others
of such compounds are described in U.S. Patent 4,000,077.
The fabric softening composition may also include other
cationic fabric conditioning materials, such as cationic

CA 02177125 2007-10-02
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anti-static materials, and non-cationic fabric softening
materials such as nonionic fabric softening materials. When
nonionic fabric softening materials are included, the weight
ratio of the cationic fabric softening material to the
nonionic fabric softening material should be at least about
1:1, preferably at least about 3:1. The fabric softening
composition may also include fatty acid.
The fabric conditioning compositions according to the
invention may be in liquid, paste or granular solid form.
When in liquid form, the product may be in the form of a
dilute rinse conditioner (containing up to about 10% by
weight total active material) or in concentrated form.
Suitable formulations for concentrated rinse conditioners
will include viscosity control agents such as are disclosed
in GB 2 053 249 (Unilever Limited) where the compositions
contain materials such as polyethylene glycol and
US 4 149 978 (Goffinet assigned to Procter & Gamble Company)
where the composition contain hydrocarbons. An alternative
viscosity control agent is ianolin.
In dilute liquid fabric softening compositions the
concentration of the fabric conditioning agent may be from
about 0.5% to about 10% by weight, preferably from about 1.5%
to about 10% by weight. In concentrated liquid fabric
softening compositions the concentration of the fabric
softening agent may be from about 10% to about 60% by weight,
preferably from about 10% to about 50% by weight.
When in liquid form, the fabric softening composition will
contain, in addition to the fabric conditioning agent and the
amphoteric polymer a liquid carrier such as an aqueous base

C-59 217 7 l 25
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which may consist only of water or of a mixture of water with
other materials such as those referred to below.
The pH of the products of the invention may lie between about
3 and about 10, although products having a pH about 2 and
about 3 are also possible. Suitable products can be prepared
having a pH between about 6 and about 10. It is especially
preferred if the fabric conditioner has pH from 5 to 8,
measured at a 1% dilution of the product in water.
The compositions according to the invention may further
include materials conventionally added to fabric conditioning
compositions such as buffering agents, organic solvents,
emulsifiers, colouring materials, bactericides, antioxidants,
perfumes, perfume carriers, bleaches and hydrotropes.
When the fabric softening composition is in solid eg granular
form, it may be prepared either by dry mixing the ingredients
or by adsorbing the ingredients on a solid carrier, such as
silica. Alternatively the composition may be formed in to a
slurry which is subsequently spray dried.
The compositions of the present invention may be prepared by
a variety of methods. One suitable method, in the case of
dilute liquid fabric softening compositions, is to form a
molten premix consisting of the fabric conditioning agent,
water and optionally a solvent and adding the amphoteric
polymer to this molten premix in the presence of sufficient
water to give the desired dilution in the product.
The invention may be used to provide a softening effect in
conjunction with any anionic detergent active or any
detergent composition containing mixtures of anionic
detergent active with other components, such as non-ionic
detergents.

C_-o 5 9 217 712 5
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The invention also comprises a method of rinse conditioning
laundry items including the step of adding a fabric
conditioning composition containing a cationic fabric
softener and a amphoteric deposition polymer preferably
having charged units a) and b) as herein described.
The invention will now be described by way of example only
and with reference to the following non-limiting examples.
Examples of the invention will be illustrated by a number,
comparative Examples will be illustrated by a letter.
Preoaration of ExamAles
Composition were prepared by forming an aqueous dispersion of
cationic active, adding the amphoteric polymer and adjusting
the pH using sodium hydroxide.
Testina Methodoloav
Anionic surfactant (weight as exemplified) was added to
1 litre of water in a Tergotometer 400 and agitated. The
rinse conditioner composition according to the Example was
added followed by 40g of pre-harshened fabric monitors.
Agitation was continued for 10 minutes, the cloths were
removed, hand wrung and line-dried. Softening was assessed
by trained panel by a qualitative comparison of the treatment
fabrics. It is to be noted that as the tests are qualitative
the results from the comparisons are grouped into tables
according to the samples which were compared and the results
in different tables are thus not comparable. Perfume
intensity was again measured by a trained panel using a 0 (no
perfume) to 5 (extremely strong) scale. Results are quoted
as mean panel scales.

CA 02177125 2007-10-02
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Examwles 1, 2 and A
Table 1
Examples were prepared according to the standard procedure.
Composition wt%
Examp~_e 1 Example 2 Example A
Arquad~' 2HT 5 5 5
Floc Aid 19 0.15 0 0.0
Floc Aid 34 0.0 0.15 0.0
NaOH 1 molar 5 5
solution
Water ----- to 100 -----
Arcxuad 2HT is dihardened tallow dimethyl ammonium chloride,
ex Akzo"
Floc Aid 34 (ex National Starch") is a polymer mwt 180,000
:nade fr(Dm dimethyl diallyl ammonium chloride (DbiDAAC) and
acrylic acid in a molar ratio of 1:1.5.
Floc aid 19 is a terpolymer mwt 140,000 made from DbIDAAC
acrylic acid and hydroxy propyl acrylate in a molar ratio of
3.4:2.3:1.

Ca..o 59 2177125
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Table 2
Anionic Level Perfume Score
Example 1 Example 2 Example A
No Anionic 1.6 1.3 1.1
20 ppm Anionic 1.5 1.4 -
40 ppm Anionic 1.4 1.2 -
60 ppm Anionic 0.9 1.0 0.3
The results clearly show a significant benefit in overcoming
the adverse effects of the anionic in the presence of
amphoteric deposition polymers.
Exambles 3 to 15 and B
Products were made as previously described containing 6.33
wt% Arquad 2HT 0.42wt%, tallow fatty acid, 0.2wt% amphoteric
polymer and water to 100 wt%. The pH was adjusted to 6-8
using sodium hydroxide. Example B contained no amphoteric
polymer. The ratio of DMDAAC to acrylic acid and the
molecular weight of the amphoteric polymers is shown below.

C 59 2177125
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Table 3
Example Acrylic Acid:DMDAAC mole Molecular Weight
ratio
3 1:4 2650
4 1:1 2080
5 4:1 5290
6 1:4 45,000
7 1:1 54,000
8 4:1 227,000
9 1:4 103,000
10 1:1 200,000
11 4:1 460,000
12 3:1 43,000
13 3:1 111,000
14 2:1 48,000
15 2:1 125,000
Examples 6 and 9 showed excellent softening but were
relatively unstable.
Softening of fabric was measured as previously described.
Softening results at 1:1.5 cationic : anionic ratio were
measured and are illustrated below.

- - ------- ------
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Table 4
Example Preference Score*
3 28
4 21
5 23
B 0
*Scale 0 - 36 increasing softness
Table 4 demonstrates that compositions containing amphoteric
polymers with low molecular weights provide a preferential
softening effect as compared with compositions which are free
of such polymer.
Table 5
Example Preference Score (0-36)
6 34
7 20
8 18
B 0
Table 6
Example Preference Score (0-36)
9 36
10 20
11 13
B 3

- --- - -- ------ ------- ------
2177125
C .__ ~ 9
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Tables 5 and 6 demonstrate that, a preferential softening
effect is achieved with a high DMDAAC : acrylic acid ratio.
Ratios with high acrylic acid to DMDAAC do not exhibit such
pronounced softening effects. Acceptable softening is
obtained over a wide range of polymer molecular weights.
Table 7
Example Preference Score (0-24)
12 17
13 17
2
Table 8
Example Preference Score (0-24)
14 17
15 17
B 2
Examnle 16 and Examvle C
Examples were prepared by adding the amphoteric polymer to
the water, adjusting the pH to 12.5, then adding the cationic
active to form a dispersion.

C 59 2177125
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Table 9
Composition Wt.%
Example 16 Example C
HEQ* 5.03 5.91
Floc Aid 34 0.15 -
NaOH 1 molar To pH 12.5 -
Solution
Water To 100%
* HEQ is 1.2 bis[hardened tallowoyloxy]-3-trimethylammonium
propane chloride with fatty acid at 6:1 ratio (ex Hoechst).
[contains associated solvent 9.3% I.P.A & 8.9% glycerol % of
total weight of cationic].
The examples were tested as stated above. The ratio of
cationic to anionic are as exemplified below:

c>9 2177125
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Table 10
Cationixmmirionic Softness Score (low = soft)
Example 16 Example C
1:0 4.3 3.3
1:05 4.8 5.5
1:067 6.8 8.0
1:08 7.5 8.8
1:1 6.5 8.5
1:1.5 7.5 8.5
The softness scores in the above table are absolute softness
scores in that each cloth was assessed by a trained panel and
given a softness score based on a standard 2 to 14 scale.
25