NZ223020A

NZ223020A - Thickened bleach composition

Info

Publication number: NZ223020A
Application number: NZ223020A
Authority: NZ
Inventors: Harold Russell Motson
Original assignee: Ici Plc
Priority date: 1986-12-24
Filing date: 1987-12-21
Publication date: 1990-04-26
Also published as: AU605531B2; GB8630845D0; DE3772957D1; ATE67240T1; EP0274885B1; EP0274885A1; AU8294487A

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

' ,'V r^" Specification F.icd: c-b: Pubi'cr*-" ~ D.vc: ;P.O. j. . l-)3j. ;22 3 0 2 0 ;No.: Date: ;NEW ZEALAND ;PATENTS ACT, J 953 ;COMPLETE SPECIFICATION ;BLEACHING COMPOSITIONS ;„' ) ;IMPERIAL CHEMICAL INDUSTRIES PLC a British Company of Imperial Chemical House, Millbank, London, SW1P 3JF, England ;C;A ;P tH ;If 2lDEc^87 ;hereby declare the invention for which i-/ we pray that a patent may be granted to ipc/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- ;- 1 - (followed by page la) ;It ;2£»3 0 2 0 ;Bleaching CuaipusHilons 1 ;THE PRESENT INVENTION relates to bleaching and cleaning compositions containing hypochlorite and in particular to thickened bleach compositions, that is compositions having an increased 5 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 10 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 15 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. ;20 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 Cg to C^g fully saturated fatty acid and a hypochlorite-soluble surface active agent, the latter being exemplified by an amine oxide containing a Cg 25 to Cjg alkyl group. The amine oxides described in the specification are those commercially available which are derived from naturally occuring Cg to Cjg fatty acids, for example coconut acids, lauric acid and myristic acid. ;British Patent Specification No 2,051,162A describes thickened 30 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 Cg to 35 C20 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. ;I ;I ;3 0 ;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 5 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 10 alkyl chain length up to the solubility of the amine oxide component. ;TABLE A ;15 ;20 ;Type ;Amine Oxide | Concentration I % w/w ;Sodium Laurate % w/w ;I Viscosity I cPs ;Cloud point °C ;Cl5 ;1 1.5 ;0.05 ;I 261 ;32 ;Cl5 ;I 1.0 ;0.05 ;] 167 ;30 ;Cl5 ;I 0.75 1 ;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 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 nCj5 alkyl amine oxide 30 content. Conversely it also illustrates that viscosity decreases with an increase in nC^4 alkyl amine oxide content. ;« ;3 H341&2 3 0 2 0 ;TABLE B ;Amine Oxide ;1 ;Viscosity ;I Cloud Point | ;Type ;| Concn ;Type | ;Concn | ;cPs ;1 °c | ;I % w/w ;1 ;% w/w | ;1 1 ;nC15 ;I 1.0 ;nCi4l ;0 1 ;315 ;1 58 | ;nC15 ;I 0.75 ;nCx^l ;0.25 | ;206 ;1 70 | ;nC15 ;I 0.5 ;nCi4l ;0.5 | ;122 ;1 82 | ;nC15 ;I 0.25 ;nCi4l ;0.75 | ;60 ;1 98 | ;nCis ;1 0 1 ;nCi4l 1 ;1.0 | 1 ;31 ;1 >100 | 1 1 ;Figure C and Table C illustrate that this effect is also observed with mixtures of linear and branched alkyl dimethyl amine oxides. ;15 The amine oxide used to produce the data given in Table C ;consisted of a mixture of amine oxides with the following structural formulae: ;a) Me R = nC^3H27 ;20 | ;R - N - 0 I ;Me ;( } 25 Me ;I ;b) R1 - CH - CH2 - N - 0 R1 = C10H2i ;| | r2 = Methyl ;R2 Me ;30 ;Me c) I r3 = C9H19 R3 - CH - CH2 -N - 0 R4 = Ethyl ;I I ;35 R4 Me ;4 ;t* 4 72 3 0 2 0 TABLE C 1 Type Amine Oxide I Concn |Type 1 % w/w| 1 Concn | % w/w | Viscosity cPs 1 Cloud Point | 1 °C | 1 1 1 c13 1 1.0 |nCi4 0 1 16 I > 100 | 1 c13 1 0.75 |nCi4 0.25 | 17 1 7100 | 1 cl3 1 0.5 |nCi4 0.5 I 18 1 >100 | 1 Ci3 1 0.25 !nCi4 0.75 I 1 >100 | 1 Ci3 I 0 |nCi4 1 1 1.0 1 1 24 1 >100 | 1 1 The C13 amine oxide used in the formulations shown in Table C consisted of 50% amine oxides with structure (a), 40% with structure 15 (b), and 10% with structure (c).

We have now surprisingly found that certain mixtures of amine oxides do not display the expected linear relationship between alkyl chain length and viscosity.

According to the present invention a thickened bleach 20 composition of enhanced viscosity comprises water, an alkali 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^5 amine oxides.

By the terms "C^4" and "C15" we mean that in the amine oxide 25 formula R2 the total number of carbon atoms in R]_ is 14 ^ I Rl- N —) 0, I or 15 respectively. In this formula R2 and R3 are preferably selected .. j from lower ie to C4 alkyl radicals, more preferably each of R2 and R3 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 35 40% w/w of straight chain (^4 amine oxide.

I ~ 22 3 0 2 0 H34149 The C15 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 5 have unexpectedly enhanced viscosities compared with the following prior art systems: (a) C15 amine oxide alone, (b) a mixture of straight chain C15 amine oxide and straight chain C14 amine oxide, and (c) a mixture of straight chain C14 amine oxide with a mixture of C13 branched and straight chain amine oxides. This is graphically 10 illustrated by the non-linear appearance of Figure 1 accompanying this specification when compared with Figures A, B and C. The enhanced viscosity provided by the compositions of this invention has the considerable advantage that appreciably less thickening agent is required to achieve a commercially acceptable viscosity than is the 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. 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 10% by weight.

The compositions of this invention preferably have a viscosity of at least 10 centistokes at 25°C, measured with a Brookfield RT viscometer using a No 3 spindle at 100 rpm, and a cloud point in 30 excess of 40°C.

The following examples, in which all parts and percentages are by weight and all viscosities are measured at 25°C with a Brookfield viscometer, further illustrate thickened bleach compositions according to this invention. t "342'2 3 0 2 0 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 4 straight chain amine oxide and a mixture of branched and straight chain C15 amine oxides, in amounts as set out in Table 1.

The C15 amine oxides had the following structural formulae: e) f) R5 - Me I N - 0 I Me Me R6 - CH - CH2 - N - 0 R5 = nC^5H3i R6 = C12H25 r7 = Methyl w' g) R7 R8 - CH - CH2 I R9 Me Me I N - 0 I Me R8 = CUH23 R9 = Ethyl The mixture of C^ amine oxides used in the compositions of Table 1 comprised 50% amine oxide with structure (a), 40% amine oxide with structure (b), and 10% structure (c). In Table 1, compositions 1 to 3 30 are according to this invention and compositions D and E are comparative compositions according to the prior art■ a M 7 H3414^) 2 3 0 2 0 TABLE 1 | Example Amine Oxide Viscosity | Cloud Point | 1 Type I Concn IType IConcn CPS | °C | | I % w/w 1 I % w/w 1 1 D C15 I 1.0 1 nCi4 1 0 173 | 36 | | 1 C15 I 0.75 1 nC^ I 0.25 225 | 47 | 1 2 C15 I 0.5 1 nCi4 I 0.50 207 | 55 I 1 3 Cl5 | 0.25 1 nC]_4 I 0.75 94 | 71 1 1 - ^ | E 1 c15 1 0 1 1 nCiA 1 I 1.0 59 | 1 86 I The full line in Figure 1 is a plot of viscosity against percentage C^5 amine oxide in the thickening agent for the 15 compositions of Table 1. For comparative purposes, the substantially 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 is 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 25 comparative compositions not according to the invention. Figure 2 is a plot of the viscosities of these five compositions against their C15 amine oxide content, again illustrating the enhanced viscosity H341 11 3 02 0 TABLE 2 | Example| Amine 3xide Sodium I Viscosity Cloud Point | 1 1 Type I Concn 1 Type IConcn Laurate | CP °C | 1 1 I % w/w I I % w/w % w/w 1 1 1 F | c15 I 1.0 1 nCi4 1 o 0.05 I 180 33 | 1 A | c15 I 0.75 1 nCj.4 I 0.25 0.05 I 214 40 | 1 5 | c15 I 0.5 1 nCi4 I 0.5 0.05 1 175 55 | 1 6 | c15 | 0.25 1 nCi4 | 0.75 0.05 | 125 65 | 1 G | 1 1 c15 1 o 1 1 nCi4 1 I 1.0 1 0.05 1 75 1 86 | 1 W' H34149/DLMS1/JF I

Claims

I <"~S WHAT J7WE CLAIM IS: CLaifflB-

1. A thickened bleach composition which comprises water, an alkali metal hypochlorite and a thickening agent comprising a mixture of (i) straight chain C^4 amine oxide with, (ii) a mixture comprising branched chain and straight chain amine oxides.

2. A thickened bleach composition as claimed in claim 1 wherein the thickening agent comprises 10 to 60% w/w of straight chain C14 amine oxide.

3. A thickened bleach composition as claimed in claim 1 or 2 wherein the thickening agent comprises 20 to 40% w/w of straight chain C^4 amine oxide.

4. A thickened bleach composition as claimed in any one of the preceding claims wherein the C15 amine oxide component of the thickening agent comprises at least 25% w/w of branched chain material.

5. A thickened bleach composition as claimed in claim 4 wherein the C15 amine oxide component of the thickening agent comprises 45 to 55% w/w of branched chain material.

6. 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.

7. 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.

8. 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 (i) straight chain C14 amine oxide with, (ii) a mixture of <3^5 amine oxides wherein the 0^4 amine oxide comprises 25 to 75% w/w of the total amine oxide content of the composition and wherein the mixture of <^5 amine oxides comprises 50% of amine oxide of formula Me r5 ■ n " ° , | / I 27MAKi990 I : °~r^'VPD / I 22 3 02 0 10 H34149/AU where is nCi5H3i, 40% of amine oxide of formula Me I R6 - CH - CH2 ~ N - 0 I I R7 Me where R6 is C12H25 and r7 is methyl and 10% of amine oxide of formula Me I R8 - CH - CH2 - N - 0 where R^ is C11H23 and R9 is ethyl. R9 Me

9. A thickened bleach composition as claimed in claim 8 wherein the composition additionally contains an alkali metal salt of a fatty acid.

10. Thickened bleach compositions substantially as hereinbefore described with reference to any one or more of Examples 1 to 6. DATED THIS 2\ C--V Cr # O v t.i A. J. PARK & SON \[N r> PER c AGENTS FOR T: !£ APPLICANTS