NO780309L - STABILIZED PRODUCT. - Google Patents

Description

Stabilized product

The invention relates to a stabilized product; in particular a stabilized product which includes a polyoxyacylene compound and/or an anionic surfactant.. •

The invention therefore includes a product containing , one or more polyoxyalkylene compounds and/or an anionic surfactant and a stabilizing amount of an alkane substituted with at least 3 hydroxyphenyl groups.

Suitable substituted alkanes include those of the formula: ZCHX1CHR1R2 12 where R and R are hydroxyphenyl groups and where Z is hydrogen, a phenyl or hydroxyphenyl group, an alkyl group, or a group of formula YCHX<2>wherein Y is hydrogen, a phenyl or hydroxy -phenyl or alkyl group or a group of formula X<3>X<4>HC(CH2)where m is 0 or an integer with a value of 1-4, where at least 1 2 3 4 one of X , X , -X and X represent a hydroxyphenyl group, the remainder being hydrogen. . It is preferred that each hydroxyphenyl group is substituted in an ortho-position relative to the -OH group by an alkyl or cycloalkyl group having 1-8 carbon atoms. It is also preferred that this is a tertiary group, for example a tert .-butyl or a tert.-octyl group The hydroxyphenyl group is also preferably substituted by at least one further alkyl group which again suitably has 1-8 carbon atoms, for example a methyl or tert.-butyl group, in the other ortho or in the meta position Preferred hydroxyphenyl groups are 1-hydroxy-3,6-dialkylphenyl groups.

Examples of particularly suitable substituted alkanes have the formula:

where n is 0 or an integer in the range 1-4, and is preferably 12 3 4 3 , and R , R , R and R are hydroxyphenyl groups; or the substituted alkane has the formula:

12 ■'12

where R and R are hydroxyphenyl groups and one of X and X is a hydroxyphenyl group and the other is hydrogen, and A is a methyl or phenyl group or hydrogen. A substituted alkane of the first-mentioned type can be prepared by condensing 3-methyl-6-tert-butylphenol with glutaraldehyde, in which case n is 3 and r\ R 2 , R and R 4 are all 1-hydroxy-3- methyl 1-6-tert-butyl-phenyl groups, and a substituted alkane of the other type can be prepared by condensation of 3-methyl-6-tert-butylphenol with crotonaldehyde

or aldol, A in this case being a methyl group and and

.R 2 are 1-hydroxy-3-methyl-6-tert-butylphenyl groups, the 1 2

other X or X is hydrogen.

The polyoxyalkylene compound contains repeating oxyalkylene groups which most often originate from ethylene and/or propylene oxide/i.e. that the compound contains the group (CHRCH„0)Pwhere R is a methyl group or hydrogen and p is an integer. Such compounds are encountered in the area of non-ionic surface-active agents where a surface-active molecule may contain one or more of the groups (CHRCH 0 ) as a result of alkylation of a substrate containing an active hydrogen atom. Such substrates include alcohols, for example C, - C2q/preferably Cg - C-^-alkanols, glycols, for example propylene glycol, carboxylic acids, for example - C2Q-alkanoic acids and tall-, oleic acids, amines, for example C-^- C -^-mono-, di- and polyamines, and phenols, for example alkyl-substituted phenols, especially phenols which are substituted in the para-position with a C,- - C-^-alkyl^ group. The polyoxyalkylene chain in this product type can contain up to 70 alkylene oxide units, i.e. that p is 1 - 70, but it preferably contains up to 50, especially up to 30 units.

The anionic surfactants which can be used in products according to the invention include carboxylates, sulphonates and sulphates. The carboxylates are typically sodium or potassium salts of C^ 2 - ^ 22 ~ ' sPecially ci 2 ~ C 18 alkanoic acids. The sulfonates include sodium or potassium, ammonium, or triethanolamine alkyl or alkene sulfonates in which the alkane or alkene group contains 10-20, especially 12-18, carbon atoms or sodium or potassium alkylbenzene sulfonates in which the alkyl group contains 6 -16 carbon atoms, for example a linear C^2 alkyl group. The sulfate can be an alcohol sulfate, for example a sodium, potassium, ammonium or triethanolamine-C^-C-^g-alcohol sulfate or a similar salt of an ethoxylated alcohol sulfate or ethoxylated alkylphenol sulfate, the number of ethylene oxide units typically being 1-5 and the alkyl group in the alkylphenol contains 6-16 carbon atoms. -In general, the sodium salts are the derivatives that are used the most.

Most surfactant products contain other ingredients apart from any polyoxyacrylic and/or anionic surfactant, and in the product according to the invention one or more of the following ingredients may also be present: a builder, for example sodium tripolyphosphate, a foam booster, for example a coconut oil mono- or di-ethanolamide, a soil carrier, for example sodium carboxymethyl cellulose, an anti-corrosion agent, for example sodium silicate, an optical brightener, a bleaching agent, for example sodium perborate, or sodium percarbonate, an alkali, for example sodium carbonate, a filler, for example sodium sulphate, and optionally an enzyme.

The products according to the invention are usually produced in solid form by a spray drying process, and it is during this process that the products are most susceptible to degradation. Although the spray drying process can be carried out in a number of ways, it usually involves an aqueous solution of the components of the product which comes into contact in droplet form with a co-current or counter-current hot air (up to 400°C) whereby the water evaporates leaving a mass of voluminous granules. in the absence of the substituted alkane the products tend to darken in colour, and if the product includes a polyoxyalkylene compound there is a risk of fire and/or explosion in the drying installation as a result presumably of peroxide formation.

The product according to the invention preferably contains 0.0005-5.0% by weight of the tris(hydroxyphenyl)alkane, more preferably 0.005-5.0% by weight, based on the weight of a polyoxyacylene compound and/or anionic surfactant.

If the product in question is to be used as a detergent, the amount of surfactant in the product (polyoxyalkylene and/or anionic surfactant) varies depending on the purpose of the product. For heavy duty purposes, 5-25% by weight of surfactant may be present, while for light duty purposes the figures may vary between 15 and 40% by weight. The rest of such products can then be made up of the other conventional components indicated earlier in this description, the heavyduty product containing a builder as a significant component (30-60% by weight) while the light duty product generally contains a large amount of filler (50-75% by weight).

In addition to their use in detergent compositions, polyoxyethylene compounds also find use as components in hydraulic fluids, as lubricants for synthetic fibers and as antistatic agents in high-temperature spinning of polyester and polyamide fibers. In these applications, the polyoxyalkylene compound in question can also be stabilized by the presence of a tris(hydroxyphenyl)alkane.

. In the following, the invention will be described with help

of examples.

EXAMPLE 1

The stability of a product according to the invention was determined by measuring the vapor pressure over a temperature range. The product was based on a mixture of C-^- and C-^-straight-chain and α-methyl branched alkanols which had been ethoxylated to an average of 9 ethylene oxide units per molecule. To this mixture was added varying amounts of a tris(hydroxyphenyl)alkane marketed by ICI Ltd. under the trade name "TOPANOL" CA

(tris(2-methyl-4-hydroxy-5-tert-butyl-phenyl)butane). : The results are shown in Figure 1, with a rapid rise in vapor pressure indicating the initiation of thermal decomposition.

EXAMPLE 2

A washing powder mixture which comprised as the polyoxyalkylene nonionic surface active agent a mixture of C13~°^C^^-straight-chain and α-methyl branched alkanols which had been ethoxylated to an average of 7 ethylene oxide units per molecule, was tested by simulating the heat exposure conditions of powder bed in a spray dryer as follows:

Test I

A layer of powder is placed in an environment with hot air

and kept at a constant temperature for at least 2 hours, with the temperature inside the sample being recorded. The temperature at which an exotherm develops is noted, as well as whether the sample reaches red heat or not.

Test II

In a modified version of Test I, air is blown through the sample during the test to simulate drying conditions in which an ample supply of air is available.

The powder was tested with (A) and without (B) 0.2% by weight of the mixture of "T0PAN0L" CA. (1.0% by weight based on the polyoxyalkylene compound). The results were as follows:

In test II, the exotherm started with the powder that did not contain "TOPANOL" CA at 150°C while the exotherm; not'.started in the powder containing "TOPANOL" CA until the temperature 'reached 220°C. At 140°C, in the latter * case there was no exotherm after 18 hours.

The effect of "TOPANOL" CA in these tests is shown to be inhibition of any marked exothermic activity 'under'. 200°C,

■ and an increase at constant temperature of the duration of. the exposure time before the exotherm is initiated..;" ; -.

EXAMPLE 3. •''■.••••..'<;>.:;'<.>■..

The principal thermal stability of a'polyoxyacylene compound was investigated in the presence and absence of "TOPANOL." ■ Approx.

The polyoxyalkylene compound was a mixture of C]_3" °?'C]_5" straight chain and α-methyl branched alkanols ethoxylated to a

average of 11 ethylene oxide units per molecule. The investigation was carried out by means of thermogravimetric analysis, whereby 25 + 1 mg of the material to be tested was weighed into a small aluminum sample mold (weight 13 mg) which was then placed on a scale in a heated closed room, aids were provided for continuous recording of the sample's temperature. Air was passed through this space for the duration of the test, the sample being first heated to the test temperature under a nitrogen atmosphere. :■

The results were as follows:

The rates of heat generation at the different temperatures were as follows: ...

These results again demonstrate the improved thermal stability in the presence of air for a polyoxyacylene compound in the presence of a trishydroxyphenylalkane ("TOPANOL" CA).

EXAMPLE- 4

A product which is typical of the invention and contains an anionic surfactant, consists of:

Claims (16)

1. Product, characterized in that it contains one or more polyoxyalkylene compounds and/or an anionic surfactant and a stabilizing amount of an alkane substituted with at least 3 hydroxyphenyl groups. • 2. Product as stated in claim 1, characterized in that the substituted alkane has the formula: ZCHX^Cffi^R <2> 12 where R and R are hydroxyphenyl groups, and where Z is hydrogen, a phenyl or hydroxyphenyl group, an alkyl group or a group of the formula Y CHX<2> where Y is hydrogen, a phenyl or hydroxy-phenyl or alkyl group or a group of formula: 3 4 XX HC(CH„) 2 m where m is 0 or an integer with a value of 1-4 where at least one 12 3 4 of X , X , X <3> and X <4> represents a hydroxyphenyl group, the remainder being hydrogen. 3. Product as stated in claim 1 or 2, characterized in that each hydroxyphenyl group in the substituted alkane is substituted in an ortho position in relation to the -OH group with an alkyl or cycloalkyl group, preferably a tertiary> group which has 1- 8 carbon atoms, for example a tert-butyl or tert-octyl group. 4. Product as stated in claim 3, characterized in that the hydroxyphenyl group is substituted with at least one further alkyl group, preferably containing 1^-8 carbon atoms in the second ortho or meta position, for example a methyl or tert.-butyl group. 5. Product as stated in any of the preceding claims, characterized in that the hydroxyphenyl groups are 1-hydroxy-3,6-dialkylphenyl groups. 6. Product as stated in any of the preceding claims, characterized in that the substituted alkane has the formula: where n is 0 or an integer in the range 1-4 and R 1, R 2 , R 3 and R <4> are hydroxyphenyl groups, or the substituted alkane has the formula: 12 '12 where R and R are hydroxyphenyl groups and one of X and X is a hydroxyphenyl group and the other is hydrogen, and A is a methyl-elier phenyl group or hydrogen. 7. Product as specified in claim 6, characterized y e d at (a) the substituted alkane has formula I and ri is 3 and 1'234 R , R , R and R are all 1-hydroxy-3-methyl-6-tert-butylphenyl groups or, (b) the substituted alkane has formula II and A is a methyl 1- 12^ 12 group and R and R and one of X and X are 1-hydroxy-3-methyl 1-6-tert-butylphenyl groups and the other X"*" or X is hydrogen. 8. Product as stated in any of the preceding claims, characterized in that the polyoxyalkylene compound contains repeating oxyalkylene units derived from ethylene and/or propylene oxide and contains the group (CHR.CH-O) where R is a methyl group or hydrogen and p is an integer in the range 1-70, preferably 1-30. 9. Product as stated in claim 8, characterized in that the polyoxyalkylene compound is produced by carboxylation of a substrate containing an active hydrogen atom, for example an alcohol, a glycol, a carboxylic acid, an amine or a phenol 10. Product as stated in claim 9, characterized in that the substrate is a C,-Cort-, preferably a C0 -C,0 -, JL ZU o JLo alkanol, propylene glycol, a C^ -C2Q -alkanoic acid, tall oil acids, a C^ -C2Q -mono-, di- or -polyamine, or an alkyl-substituted phenol-, preferably a para-C8-C-^ -alkyl substituted phenol. 11. Product as specified in any of the preceding claims, characterized by . that the anionic surfactant is a carboxylate, a sulfonate or sulfate. 12. Product as stated in claim 11, characterized in that the anionic surfactant is a sodium or potassium salt of a C^2 -C^ g-alkanoic acid, a sodium or potassium, ammonium or triethanolamine alkane or alkene sulfonate in which the alkane or alkene group contains 10-20 carbon atoms, a sodium or potassium alkylbenzene sulfonate in which the alkyl group contains 6-16 carbon atoms, or a sodium, potassium, ammonium or triethanolamine alcohol sulfate, ethoxylated alcohol sulfate or ethoxylated, alkylphenol sulfate. 13. Product as stated in any of the preceding claims, characterized in that it also contains one or more of a builder, a foam booster, a dirt carrier, an anti-corrosion agent, an optical brightener, a bleaching agent, a filler and an enzyme. 14. Product as specified in any of the foregoing. requirement, characterized in that it is exposed to a spray drying process. 15.. Product as stated in any of the preceding claims, characterized in that it contains 0.0005-5.0% by weight, preferably 0.005-5.0% by weight, based on the weight of polyoxyacylene compound and/or anionic surfactant of the tris(hydroxyphenyl)alkane. 16. Method for producing a spray-dried detergent, characterized in that a product as stated in claim 1 in solution in water and in droplet form is exposed to heat. air in co-flow or counter-flow.