AU605531B2 - Bleaching compositions - Google Patents

Abstract

Thickened bleaches of enhanced viscosity consist of water, alkali metal hypochlorite and a thickening agent consisting of a mixture of straight chain C14 amine oxide with a mixture comprising branched chain and straight chain C15 amine oxides.

Description

4 il. I -i W ICr

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Int. Class Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: This document contains the amendments made under Section 49 and is correct for printing.

APPLICANT'S REFERENCE: H 34139/AU S,Name(s) of Applicant(s): Imperial Chemical Industries PLC Address(es) of Applicant(s): Imperial Chemical House, Millbank, London SWlP 3JF, UNITED KINGDOM.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK SPatent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: BLEACING COMPOSITIONS Our Ref 79212 POF Code: 1453/1453 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): t 6003q/1 1 -lA- H34149 Bleaching Compositions THE PRESENT INVENTION relates to bleaching and cleaning compositions containing hypochlorite and in particular to thickened bleach compositions, that is compositions having an increased viscosity as compared with straight aqueous solutions of alkali metal hypochlorite.

Thickened bleach compositions have a number of advantages over unthickened bleach compositions in that the more viscous compositions adhere more readily and for a longer time to vertical and inclined surfaces than do the unthickened compositions. The performance of thickened bleach compostions is therefore superior to that of unthickened bleach compositions for vertical and inclined surfaces such as are found in lavatory pans, urinals, drains, waste pipes and the like. In recent years a number of proposals have been made which provide thickened bleach compositions, for example compositions having viscosities at 25°C of greater than 10 centistokes, by the addition of suitable thickening agents. Viscosity can be further enhanced by the inclusion in such compositions of other components, for example caustic alkali, alkali metal salts.

British Patent Specification No 1,329,086 describes thickened aqueous alkali metal hypochlorite compositions which contain in addition to the hypochlorite, an alkali metal salt of a C 8 to C 18 fully saturated fatty acid and a hypochlorite-soluble surface active agent, the latter being exemplified by an amine oxide containing a C 8 to C 18 alkyl group. The amine oxides described in the specification are those commercially available which are derived from naturally occuring C 8 to C 18 fatty acids, for example coconut acids, lauric acid and myristic acid.

British Patent Specification No 2,051,162A describes thickened aqueous alkali metal hypochlorite compositions which contain, in addition to the hypochlorite, an amine oxide and an alkali metal alkyl sulphate.

British Patent Specification No 2,003,522A describes thickened aqueous alkali metal hypochlorite compositions which contain a C 8 to

C

20 branched chain amine oxide or a mixture of such amine oxides with or without the presence of an alkali metal salt of a fatty acid.

4- SH34149 European Patent Application No 079 697 suggests that as the alkyl chain length of an amine oxide increases its effectiveness as a thickening agent also increases.

In general, the prior art teaches that the viscosity of a thickened sodium hypochlorite cleaning formulation increases in proportion to the amine oxide content of the formulation. This is especially the case in formulations in which amine oxide is the sole thickening agent and is illustrated in Table A and Fig A accompanying this specification. European Patent Application No 079 697 claims that the thickening effect shown by amine oxides is a function of the alkyl chain length up to the solubility of the amine oxide component.

TABLE A I Amine Oxide I Sodium I Viscosity Cloud point 15 Type I Concentration I Laurate cPs 0

°C

w/w I w/w o C 15 1.5 0.05 261 32 I C 15 I 1.0 I 0.05 167 t

C

15 I 0.75 0.05 I 128 28 Furthermore, the prior art teaches that in a mixture of amine oxides the ability to thicken aqueous solutions of an alkali metal hypochlorite is a function of the individual thickening performance of S 25 the component amine oxides. In such a case viscosity would increase in proportion to the content of the longer linear alkyl chain amine oxides. Table B and Fig B accompanying this specification illustrate how the viscosity of a cleaning formulation containing sodium hypochlorite increases in proportion with nCi 5 alkyl amine oxide content. Conversely it also illustrates that viscosity decreases with an increase in nC 1 4 alkyl amine oxide content.

H3 4149 TABLE B Amine Oxide IViscosity I Cloud Point IType I Concn IType I Concn I cps I 0

C

1 1 w/wI W/WI InC 15 1 1.0 1 nC 1 41 0 1 315 1 58 1 InC 15 1 0.75 1nC141 0.25 1 206 1 701 InC 15 1 0.5 1nC141 0.5 1 122 1 82I 1 nC 15 1 0.25 1 nC14I 0.75 1 60 1 98 1InCisi1 0 1InC141 1.0 1 31 I >/100 I I I l I I I_ Figure C and Table C illustrate that this effect is also observed with mixtures of linear and branched alkyl dimethyl amine oxides.

The amine oxide used to produce the data given in Table C consisted of a mixture of amine oxides with the following structural formulae: Ii ii 49 C ir r R nC 1 3

H

2 7 R- N- 0 A A b) R CH -CH 2 N- 0 R2= Methyl R- CH CH 2 -N 0 1 1 R4 Me R4= Ethyl H34149 TABLE C Amine Oxide I Viscosity Cloud Point Type I Conca IType I Concn I cPs °C w/wl w/w

C

1 3 1.0 InCi 4 I 0 I 16 >100

C

1 3 1 0.75 lnC14 I 0.25 I 17 7100 I C 1 3 0.5 InC14 1 0.5 1 18 >100

C

13 1 0.25 InC14 I 0.75 I 20 >100 1

C

1 3 0 InC14 1.0 24 7100 The C 13 amine oxide used in the formulations shown in Table C consisted of 50% amine oxides with structure 40% with structure 15 and 10% with structure We have now surprisingly found that certain mixtures of amine oxides do not display the expected linear relationship between alkyl j G chain length and viscosity.

According to the present invention a thickened bleach composition of enhanced viscosity comprises water, an alkali metal hypochlorite and a thickening agent comprising a mixture of straight chain C 1 4 amine oxide with a mixture comprising branched chain and straight chain C 15 amine oxides.

I By the terms "C 14 and "C15" we mean that in the amine oxide formula R2 the total number of carbon atoms in R 1 is 14 RI- N O, R3 or 15 respectively. In this formula R 2 and R3 are preferably selected from lower ie C 1 to C4 alkyl radicals, more preferably each of R 2 and

R

3 being methyl.

In a preferred embodiment of the composition of this invention the thickening agent comprises 10 to 60% w/w, more preferably 20 to 40% w/w of straight chain C 14 amine oxide.

H34149 The C 15 amine oxide component of the thickening agent preferably comprises at least 25 w/w of branched chain material, more preferably at least 40% w/w, most preferably 45 to 55 w/w.

Over a range of concentrations the compositions of the invention have unexpectedly enhanced viscosities compared with the following prior art systems: C 15 amine oxide alone, a mixture of straight chain C 15 amine oxide and straight chain C 1 4 amine oxide, and a mixture of straight chain C 14 amine oxide with a mixture of C 13 branched and straight chain amine oxides. This is graphically illustrated by the non-linear appearance of Figure i accompanying this specification when compared with Figures A, B and C. The enhanced viscosity provided by the compositions of this invention has the o I considerable advantage that appreciably less thickening agent is required to achieve a commercially acceptable viscosity than is the o 15 case with prior art compositions.

Optionally, the compositions of this invention may also contain an alkali metal salt of a fatty acid, for example sodium laurate, as an additional component to aid thickening. The effect of enhanced viscosity is maintained in the compositions which contain such a salt.

4, o 20 Optionally, thickened bleaches according to this invention can contain additional components frequently incorporated in such compositions including caustic alkali, alkali metal salts, perfume and colourants.

The bleach compositions of this invention preferably contain an 25 amount of available chlorine in the range 1 to 15%, preferably 5 to 4 10% by weight.

o*°a The compositions of this invention preferably have a viscosity of at least 10 centistokes at 25 0 C, measured with a Brookfield RT viscometer using a No 3 spindle at 100 rpm, and a cloud point in excess of The following examples, in which all parts and percentages are by weight and all viscosities are measured at 25C with a Brookfield viscometer, further illustrate thickened bleach compositions according to this invention.

6 H34149 Examples 1 to 3 Five thickened bleach compositions were prepared by mixing in water sufficient sodium hypochlorite to give an amount of available chlorine of 8% and a thickening agent consisting of dimethyl C 14 straight chain amine oxide and a mixture of branched and straight chain C 15 amine oxides, in amounts as set out in Table 1.

The C 15 amine oxides had the following structural formulae:

R

5 N 0

R

5 N 0 R5 =nC 15

H

3 1 a4~ 0""9 Oaqv 0 0000 a 0 0 aQ 0 0) 0 000 0 00* 0D 0 90094 0 *0 00 9 00 0 10 '00 00 0 0 00 0 0 -N 0

R

6 C12H25

R

7 Methyl CH CH2 R7

I

-N 0

R

8 C1H23

R

9 Ethyl R 8 CH CH2 R9 The mixture of C 15 amine oxides used in the compositions of Table 1 comprised 50% amine oxide with structure 40% amine oxide with structure and 10% structure In Table 1, compositions 1 to 3 are according to this invention and compositions D and E are comparative compositions according to the prior art I 7 H34149 TABLE 1 Example I Amine Oxide I Viscosity Cloud Point i I Type I Concn IType |Concn I CPS IC I w/w I w/w SD C 15 I 1.0 I nCi4 0 1 173 1 36 1 C15 0.75 1 nCl4 1 0.25 225 47 I 2 C 15 0.5 nC14 0.50 207 55 I 1 3 1 C 15 1 0.25 I nC14 I 0.75 1 94 71 E IC 1 5 0 nC14 1.0 59 86 I The full line in Figure 1 is a plot of viscosity against percentage C 15 amine oxide in the thickening agent for the compositions of Table 1. For comparative purposes, the substantially j straight line plot which would be expected from a consideration of prior art compositions is included as the dotted line in Figure 1.

The enhanced viscosity of the compositions according to this invention Sis clearly shown.

Example 4 to 6 A further five compositions were prepared identical to those shown in Table 1 except that each additionally contained 0.05 wt% sodium laurate. The compositions and their viscosities and cloud points are shown in Table 2, compositions F and G again being comparative compositions not according to the invention. Figure 2 is a plot of the viscosities of these five compositions against their C 1 amine oxide content, again illustrating the enhanced viscosity effect.

8 H-34 149 TABLE 2 Example]- Amine Oxide iSodium IViscosity[Cloud Point I Type I Concn IType IConcn ILauratel CP I 0

C

1 I~ I W/wI W/WI_ I I F I C 15 1.0 1 nC1t4 1 0 10.05 1 180 1 33 1 4 1 C 15 10.75 1nC 1 4 1 0.251 0.05 1 214 1 1 5 1 C 15 1 0.5 I nC14 I 0.5 1 0.05 1 175 1 1 6 1 C 15 10.25 1 nC14 1 0.751 0.05 1 125 1 1 G I C 15 10 InC]4 1 1.0 1 0.05 1 75 1 86

I

Claims (2)

1. A thickened bleach composition which comprises water, an alkali \o lo &o% metal hypochlorite and a thickening agent comprising a mixture of straight chain C14 amine oxide with a mixture comprising branched chain and straight chain C 15 amine oxides. A Ll ii k c-ata itp- i--a a- lafanz h L.LI -n1 Aa/nt1 om 4- o f f A thickened bleach composition as claimed in claim 1 P--2 wherein the thickening agent comprises 20 to 40% w/w of straight chain C 14 amine oxide. A thickened bleach composition as claimed in any one of the preceding claims wherein the C 15 amine oxide component of the thickening agent comprises at least 25% w/w of branched chain material. A thickened bleach composition as claimed in claim -4wherein the C 15 amine oxide component of the thickening agent comprises 45 to w/w of branched chain material. S. A thickened bleach composition as claimed in any one of the preceding claims wherein the composition additionally contains an alkali metal salt of a fatty acid. A thickened bleach composition as claimed in any one of the preceding claims wherein the composition contains an amount of available chlorine in the range 1 to 15% by weight. 'As. A thickened bleach as claimed in any one of the preceding claims comprising water, an alkali metal hypochlorite and a thickening agent comprising a mixture of straight chain C 14 amine oxide with a mixture of C15 amine oxides wherein the C 14 amine oxide comprises 25 to 75% w/w of the total amine oxide content of the composition and wherein the mixture of C15 amine oxides comprises 50% of amine oxide of formula Me N 0 Me E r :i i 4 H34149/AU where R 5 is nC1 5 H 31 40% of amine oxide of formula Me R 6 CH CH

2 N 0 R7 Me where R 6 is C 12 H 25 and R 7 is methyl and 10% of amine oxide of formula Me R8 CH CH2 N 0 where R 8 is C 1 1 H 23 and R 9 is ethyl. R 9 Me -7 S. A thickened bleach composition as claimed in claim 4wherein the a composition additionally contains an alkali metal salt of fatty acid. A accr0Ao CAc.v. 1. 1.9,l hickened bleach composition substantially as hereinbefore described with reference to any one or more of Examples 1 to 6. DATED: 22 December 1987 PHILLIPS ORMONDE FITZPATRICK Attorneys for: IMPERIAL CHEMICAL INDUSTRIES PLC 4 p *t