GB2067588A

GB2067588A - Ovens cleaning compositions

Info

Publication number: GB2067588A
Application number: GB8001539A
Authority: GB
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1980-01-17
Filing date: 1980-01-17
Publication date: 1981-07-30
Also published as: EP0033601A1

Description

1

GB2067 588A 1

SPECIFICATION

Alkaline cleaning compositions

5 The present invention relates to alkaline cleaning compositions, particularly aqueous alkaline compositions adapted for use in non-aerosol form and suitable for cleaning hard surfaces such as ovens and the like.

It is known from British Patent Specification 1 297 782 to use, as oven cleaning compositions, aqueous alkali compositions which contain caustic alkali, an alkali-stable organic detergent

10 active compound, and an aliphatic monohydric alcohol and which are adapted for use in aerosol form. It is also known from United States Patent Sepcification 3 829 387 to use, as an aerosol oven cleaning composition, an aqueous alkali composition containing caustic alkali, a glycol either and a non-ionic detergent active compound.

We have now surprisingly discovered that particularly good cleaning results can be achieved

15 with a cleaning composition comprising an aqueous base containing:

(i) from about 1 % to about 6% by weight of a non-ionic surfactant;

(ii) from about 1 % to about 40% by weight of an alkali; and

(iii) from about 5% to about 20% by weight of a solvent.

The non-ionic surfactant is preferably a polyoxyalkylene alkyl ether such as the "Brij"-type

20 non-ionics. Particularly suitable examples are Brij 35 (polyoxyethylene (23) lauryl ether) and Brij 78 (polyoxyethylene (20) stearyl ether). The quantity of the non-ionic surfactant may be from about 1.5% to 2.5%, preferably about 2% by weight.

The alkali is preferably a caustic alkali such as sodium hydroxide or potassium hydroxide. Alternatively silicates such as potassium silicate with a K20:Si02 weight ratio of 1:2 to 2:1.

25 Further examples of suitable alkali materials are guanidine (formed from guanidine hydrochloride and sodium hydroxide) and mono-, di- and trialkanolamines. The amount of alkali present is preferably from about 1 to about 10% by weight in the case of caustic alkalis and from about 3 to about 30% by weight in the case of an alkali metal silicate. Most preferred ranges are from about 3 to 6% by weight and from about 4 to 10% by weight respectively.

30 The solvent is preferably a high boiling point solvent (i.e. having a boiling point over about 120*C). The preferred solvents are: glycol ethers such as butyl cellusolve, methyl, ethyl or butyl carbitol; pentaerythritol propane 1,2-diol; propylene glycol; and dioxitol. The solvent is preferably present in the amount of from about 5% to about 1 5%, most preferably about 10% by weight.

35 Other ingredients may be present in the compositions of the invention. A hydrotrope may be added up to an amount of about 18% by weight, preferably from about 6% to 12% by weight. The hydrotrope may be selected from alkali metal aryl sulphonates, such as sodium xylene sulphonate, the latter also aiding soil penetration by the composition. A thickening agent may also be present, in an amount up to about 2% by weight, preferably about 0.4% by weight.

40 The thickening agent enables the product to cling better to vertical surfaces and reduces mist on spraying the neat product. Suitable thickening agents include hydroxethyl cellulose (Natrosol Registered Trade Mark), lauryl alcohol, stearyl alcohol, magnesium sulphate, sodium carbonate and sodium chloride, hydroxypropylcellulose (Klucel-Registered Trade Mark), acrylate-methacry-late polymer (Latekoll-Registered Trade Mark) or mixtures of these with hydroxyethyl celluloses.

45 The preferred amount of thickening agent is up to about 2% by weight in the case of an organic thickener, more preferably about 0.4% by weight and up to 6% by weight in the case of an inorganic thickener, more preferably about 1 to 3% by weight.

The preferred thickener is a cellulose based nonionic polymer especially the sterically hindered natrosol types. These give much better viscosity stability with time in these formulations.

50 Further optional ingredients in the cleaning compositions of the invention include dyes and humectants.

The invention will now be illustrated, purely by way of example, with reference to the following non-limiting examples, in which parts and percentages are by weight, unless otherwise stated.

55

EXAMPLES 1 TO 4

Cleaning compositions were made up according to the following table:

5

10

15

20

25

30

35

40

45.

50

55

2

GB2 067 588A

2

TABLE I

EXAMPLE

1

2

3

4

Brij 35

2.0

Carbitol

10.0

NaOH at 100°TW (46.5%)

11.0

—

KOH at 90°TW (43.4%)

—

8.0

Potassium Silicate (34%)

—

13.0

26.0

(K20:Si02= 1:2 by wt.)

Natrosol (1% sol")

—

40.0

—

Sodium xylene

sulphonate (30% a.i.)

30.0

Water

Balance to 100

A number of prior art formulations approximately according to the following table were prepared:

FORMULATION:

A

B

C

D

E

F

G

TRADE NAME:

Sactif

Dip-R-

Odex

Rocep

Glenvil

Sumaren

Gel

Aerosol

Spray

Gel

C12 gel

G.C. 10

U.G.N.

Product

Anionic

2.4

3.7

3.2

Nonionic

0.4

2.7

1.5

6.0

NaOH

3.0

6.3

KOH

16.2

9.7

nh3

1.8

1.1

2.0

Na2C03

0.9

Isopropanol

14.0

present

CH2CI2

30-40

Mineral oil

4.9

Sodium

Orthophosphate

0.4

Sodium poly

phosphate

5.0

Hydroxycarboxy

methylcellulose

0.3

Propellant

10.0

Water

balance to 100

4

GB2 067 588A

4

Examples 1 to 4 were compared with the prior art formulations A to G for detergency efficiency. The evaluation was based on the average base reflectance measurements (R 460*) on a number of soiled white test plates. The reflectance measurement on a clean plate was 69.7. The results were as follows:

TABLE III

10

15

20

20°C

1 5 minute application

60°C

5 minute application

Ex

1

59

60

Ex

2

68

87

Ex

3

17

48

Ex

4

5

19

A

0.5

22

B

5.6

84

C

1.0

25

D

14

8

E

7

71

F

5

not tested

G

5

not tested

10

15

20

EXAMPLES 5 TO 13 25 The formulations set out in the following table were prepared.

25

Ol

TABLE IV

Example 5 6 7 8 9 10 11 12 13

Guanidinium 10.0 10.0 — 5.0 — 5.0 — — —

Chloride

NaOH 4.2 — 8.4 4.2 4.2 8.4 4.2 8.4 —

Butyl cellusolve or

Carbitol 10 10 10 10 10 10 10 10 —

Brij 78 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.8

Potassium

Metasilicate 20 30

Triethanol amine 10 10 10

Water balance to 100

o

CD N3

0 O) ^1

01 00

00 >

Ol

6

GB2067 588A 6

Claims

1. A cleaning composition comprising an aqueous base containing

(i) from about 1% to about 6% by weight of a nonionic surfactant;

(ii) from about 1 % to about 40% by weight of an alkali; and

5 (iii) from about 5% to about 20% by weight of a solvent. 5

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd.—1981.

Published at The Patent Office, 25 Southampton Buildings. London. WC2A 1AY. from which copies may be obtained.