GB2095276A - Fabric washing compositions - Google Patents

Abstract

The washing of fabrics by hand is a standard procedure. The use of high molecular weight acrylamide polymers at low levels in the wash solution improves the lather properties and fabric feel during washing.

Description

SPECIFICATION Fabric washing formulations BACKGROUND TO THE INVENTION The invention relates to optionally built detergent formulations usable in hand washing of fabrics.

Hand washing of fabrics is a common method of cleaning in many countries and is still used for some washes in countries having a relatively high proportion of machine aids.

SUMMARY OF INVENTION The present invention describes an optionally built detergent formulation for fabric washing containing an acceptable high molecular weight polymer the presence of which provides improved lather properties and improved fabric feel during washing. The ease of use of detergent bars is increased.

Detergent formulations of the invention comprise from about 5% to about 60% by weight of detergent active and from zero to about 60% by weight of detergent builder characterised in that the formulation includes an effective amount of polyacrylamide polymer or acrylamide-acrylic acid copolymer. Preferably the average molecular weight of the polymer or copolymer is above 2 million and more preferably above 3 million (measured by a viscosity method).

The polymer or copolymer may be present in an amount of from about 0.05% to about 5% by weight, preferably from about 0.1% and up to about 1%, more preferably up to 0.5% by weight.

The polymers and copolymers used in this invention include polyacrylamides without anionic character and copolymers of acrylamide and acrylic acid having a degree of anionic character which can be as high as about 95% molar. Polymers with anionic character can be prepared by reacting the constituent monomers i.e. acrylamide and acrylic acid or by hydrolysing a polyacrylamide polymer, for example with sodium hydroxide solution, to the desired degree of anionic character. The latter class of materials is within the definition of copolymers.

The invention extends to the washing of fabrics in a detergent solution containing from about 5 ppm to about 50 ppm, preferably up to 30 ppm of the polymer.

The concentration of polymer or copolymer in the detergent formulation will be selected to provide a concentration in this range when the product is used at the standard in-use concentration.

However, for some applications wash solution concentrations outside this range may be desirable.

The formulations can be prepared in a convenient product form. Thus powders, liquids and bar form products can be prepared with the polymer or copolymer being incorporated at a suitable point in the processing. The polymers and copolymers may be present as mixtures.

Preferably the formulation will be built and contain at least 10% of builder material.

For detergent powders the preferred ranges are 10% to 35% active and 15% to 50% builder. For liquids the preferred ranges are from 5% to 50% for actives and from 0%, preferably 10%, to 30% for builders and for bars the ranges 10% to 40% active and 10% to 30% builder are preferred.

TEST DEFINITION OF POLYMER OR COPOLYMER The acrylamide polymers and acrylamide-acrylic acid copolymers useful in the present invention will satisfy the following test. This test measures the increase in the flowtime of a detergent solution through a fabric layer when the polymer or copolymer is incorporated in the solution.

The control detergent formulation used in the test had the composition (by weight %) of anhydrous components: sodium dodecylbenzene sulphonate 25 sodium tripolyphosphate 1 6 sodium alkaline silicate 12 sodium carbonate 7 sodium sulphate 23 sodium chloride 4 water, fluorescer, colouring, perfume to 100 A 0.3% (W/V) solution of this control formulation was prepared in 1O0H (French) water at 2O0C.

This solution was filtered using a Whatman 541 filter paper (this paper retains particles greater than 20 to 25 microns) to remove insolubles and then passed through a number of layers of cotton terry towelling with a head pressure of 10 cm of solution.

Terry towelling was desized by washing and from this 4.45 cm in diameter discs were cut. A stack of discs was then clamped between a pair of o-rings and the test solution passed through. The time for 50 ml to pass was then measured. The number of discs was selected to ensure a time between 20 and 40 seconds was obtained; generally about 10 discs were required.

A test polymer or copolymer was then added to the standard detergent formulation at a concentration of 0.33%. This polymer containing formulation was then used to prepare a test solution of the same concentration as the control solution. The solution was mixed for a period of 3 hours using a magnetic stirrer. The solution was filtered as described previously to remove insolubles. The solution containing polymer or copolymer was passed through the stack of terry towelling discs and the time for 50 ml to pass through measured. The percentage increase in flowtime obtained with a test polymer or copolymer compared with the control is defined as the Flowtime Increase Value (FIV).

A polymer or copolymer suitable for use in the present invention will increase the flowtime by at least 50%. Preferably the polymer or copolymer will increase the flowtime by at least 100%.

The polymers studied were polyacrylamide and acrylamide-acrylic acid copolymers having a molecular weight of about 10 million (measured by a viscosity method). The polymers and copolymers (except A2) are obtainable from Crosfields Ltd of Warrington, England under the Trade Mark 'Crosfloc' and had a range of anionic content up to 95%.

Both polymers designated A contained an anionic level of 2% but one sample (Al) was derived from the Crosfloc range while polymer A2 was obtained from American Cyanamid Co (an American company) under the Trade Name Superfloc N 100.

The polymers studied are given in table I.

TABLE I % Anionic character Polymer or copolymer (molar) of polymer Flowtime Increase Value used in Wash solution or copolymer (FIV) None (control) No polymer 30 seconds standard Al 2 70% A2 2 140% B 5 100% C 10 120% D 15 180% E 20 240% F 30 250% G 95 200% COMPONENTS OF THE FORMULATION Builder and detergent active components are well characterised in detergent product technology.

Examples of these components are listed here-after and full description of these and other examples of these components will be found in "Surface Active Agents" by Schwartz s Perry published by Interscience (1949) and volume II by Schwartz, Perry & Berch (Interscience 1958). Examples of detergent actives usable in the compositions of the invention are present in the general classes of anionic, nonionic, cationic amphoteric and zwitterionic species. The detergent actives and polymers used will be selected to be compatible.

Specific examples are sulphates of alcohols, both branched and straight chain containing 10 to 1 8 carbon atoms; alkaryl sulphonates having an alkyl chain from C10 to C,,; ethoxylated alcohols (C,2 to C20) having a degree of ethoxylation between 6 and 20; alkene (C12 to C24) sulphonates; alkali metal salts of longchain fatty acids (Ca to C22) and fatty acid ester sulphonates with 8 to 20 carbon atoms in the fatty acid chain.

Specific examples of the builder component are: water soluble phosphate salts, e.g. sodium tripolyphosphate, pyrophosphate and orthophosphate; water soluble carbonate salts e.g. sodium carbonate; organic builders, e.g. sodium nitrilo triacetate, sodium tartarate, trisodium carboxymethyloxysuccinate, oxydisuccinate and sodium sulphonated long chain (cur4 to C20) fatty acids: in organic builders, e.g. zeolites.

Other ingredients, for example sodium alkaline silicates, starch, sodium carboxymethyl cellulose, colouring materials, fluorescors, opacifiers, germicides, solvents, perfumes and bleaching agents are optionally added.

EXAMPLES The invention will now be described and illustrated in more detail by reference to the following non-limiting examples.

EXAMPLE I The formulations were tested for lather generation during the hand washing of fabrics. The tests were performed using the control formulation described with an added copolymer. The wash solution used 80H (French) water at 220C with the detergent formulation added at a concentration of 0.3% weight/volume. Desized cotton terry towelling and bulked polyester polymer fabric (obtainable from ICI Ltd of England under the Trade Mark 'Crimplene') pieces were washed by hand using a 100:1 liquor/cloth ratio in 1 litre of water after a 2 hour presoak in the formulation.

The lather generated by rubbing each fabric piece five times out of the liquor was gathered in a measuring cylinder; this procedure was performed five times and the total measured.

The percentage lather volume increases achieved by varying the anionic character of the copolymer and the concentration of the latter in the wash liquor are shown in Table II.

TABLE II % Increase in lather volume collected (measured at two solution concentrations of copolymer) Copolymer 5 ppm 10 ppm Al 18 27 A2 20 30 B 25 45 C 35 55 D 43' 61 E 50 68 F 52 69 G 54 72 Control Formulation foam volume: 260 ml.

The results shown in Table II demonstrate the lather produced increases with the anionic character of the copolymer and the concentration of the latter.

EXAMPLE II Assessments of fabric feel were made using the wash solution of Example I containing copolymer E. Pieces of cotton sheeting and cotton terry towelling were added at a liquor/cloth ratio of 14/1 with the solution temperature at 280C.

A direct paired comparison test was used where a panel of 100 consumers handled the fabrics in each of two bowls one of which contained added polymer. Assessments were made after a 1 hour presoak. The copolymer was assessed at a range of concentrations.

Levels of copolymer greater than 7 ppm in the wash solution gave the fabrics a significantly different feel from the control. A higher level of polymer (12 ppm) was very significantly preferred because the fabric felt softer.

EXAMPLE Ill Example II was repeated using polymer B. Levels of copolymer between 10 ppm and 40 ppm were significantly preferred because the fabric felt softer.

EXAMPLE IV A built detergent bar was prepared with the formulation (by weight) Branched alkyl (C12) benzene sulphonate 31% Sodium carbonate 18% Phosphate builder 8% Sodium sulphate 6% Particulate filler 11% Water and minor components to 100%.

Copolymer E was added at levels of 0.1% and 0.2% to samples of the bar and these samples were compared with a control bar for ease of use. Each sample was used to ciean terry towelling by rubbing the bar on an area of the bar supported on a surface. The users found the copolymer containing samples required less effort to move across the fabric surface. The test bars provided more lather during use than the control bar.

EXAMPLEV Copolymer E was incorporated in built and unbuilt liquid detergent formulations at a level of 0.33%. These formulations provided lather increase when subjected to the tests described in Example I.

Claims (11)

1. A detergent formulation comprising from about 5% to about 60% by weight of a detergent active material, from 0% to about 60% by weight of a detergent builder material characterised in that it contains an effective amount of an acrylamide polymer 6r acrylamide-acrylic acid copolymer having a Flowtime Increase Value (FIV) of at least 50% using the test described.

2. A detergent formulation according to claim 1 wherein the polymer or copolymer has a FIV of at least 100%.

3. A detergent formulation according to claim 1 or 2 wherein the polymer or copolymer has a molecular weight of at least 2 million.

4. A detergent formulation according to claim 3 wherein the polymer or copolymer has a molecular weight of at least 3 million.

5. A detergent formulation according to any preceding claim wherein the polymer or copolymer is present in an amount of from 0.05% to 5% by weight.

6. A detergent formulation according to claim 5 containing at least 0.1% of the polymer or copolymer.

7. A detergent formulation according to claim 5 containing up to 1% of the polymer or copolymer.

8. A detergent formulation according to claim 7 containing up to 0.5% of the polymer or copolymer.

9. A detergent formulation according to any preceding claim containing at least 10% of builder material.

10. A method of washing fabrics in a detergent solution containing from about 5 ppm to about 50 ppm of an acrylamide polymer or acrylamide-acrylic acid copolymer having a Flowtime Increase Value (FIV) of at least 50% using the test described.

11. A method according to claim 10 wherein the detergent solution contains up to 30 ppm of the polymer or copolymer.