DE3911004A1 - Methyl-branched paraffins, process for their preparation and their use in cosmetics and textile technology - Google Patents

Abstract

Methyl-branched paraffins of the general formula I R<1>-CH(CH2-CH2-R<2>)-CH3 in which R<1> and R<2>, which are identical or different, in particular identical, are straight-chain alkyl groups having 2 to 20, in particular 6 to 20, carbon atoms, can be prepared by dehydration of the corresponding Guerbet alcohols and hydrogenation of the olefins obtained in this way and are suitable as a result of their homogeneity, inter alia, as an ointment base for cosmetic preparations and as lubricating and/or smoothing agents in textile technology.

Description

The invention relates to methyl-branched paraffins of the general my formula I

R¹-CH (CH₂-CH₂-R²) -CH₃ (I)

in which R ¹ and R ² , which are the same or different, in particular the same, denote straight-chain alkyl groups having 2 to 20, in particular 6 to 20, carbon atoms.

There is a need for cosmetics and textile technology at relatively low temperatures liquid as well as physiolo gisch harmless or chemically inert compounds that are easy to emulsify with the formation of ointment bases or as such on textile materials to be equipped with them lien can be applied. The previously used for this Paraffin sections have the disadvantage that they consist of one Variety of different connections exist that are with each other in vapor pressure, in penetration into skin tissue or distinguish textile materials and the like. It is therefore required from taking such paraffin sections of different origins first for the respective user Determine relevant properties and the  results obtained in the formulation of more suitable Application forms to be considered.

The invention is directed to a group of paraffins which, apart from slight fluctuations in the chains length, are built up strictly homogeneously and as a result of a Methyl branching is liquid at low temperatures.

This object is achieved by the methyl-branched Paraffins of the above general formula I dissolved.

Typical examples of the hydrocarbon radicals R ¹ and R ² of methyl-branched paraffins of the general formula I are ethyl and - in each case straight-chain - propyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, Heptadecyl, octadecyl, nonadecyl and eicosyl.

The methyl branched paraffins of the invention can be obtained be made by using Guerbet alcohols of the general Formula II

R³-CH (CH₂-CH₂-R⁴) -CH₂-OH (II)

in the R ³ and R ⁴ straight-chain, saturated or unsaturated carbons are hydrogen radicals with 2 to 20, in particular 6 to 20 carbon atoms, in the presence of catalysts containing sulfonic acid groups, optionally under pressure, dehydrated and the resulting alpha-olefins of the general formula III

R³-C (CH₂-CH₂-R⁴) = CH₂ (III)

in the R ³ and R ^{4 are} as defined above, in the presence of hydrogenation catalysts, optionally under pressure, hy driert.

The Guerbet alcohols to be used according to the invention are formed in the condensation of straight-chain, primary, saturated or unsaturated alcohols, especially fatty alcohols, with 4 to 22 carbon atoms in the presence of alkali after the reaction onsschema

2 R-CH₂-CH₂-OH
→ R-CH (CH₂-CH₂-R) -CH₂-OH + H₂O

and are known or commercially available compounds. in the Guerbet alcohols of the gen my formula II are thus due to condensation e.g. from (each straight-chain and 1-OH-substituted) butanol, Pentanol, hexanol, heptanol, octanol, nonanol, decanol, Undecanol, Undecenol, Dodecanol, Tridecanol, Tetradecanol, Pentadecanol, hexadecanol, heptadecanol, octadecanol, Octadecenol, nonadecanol, eicosanol, eicosenol, heneicosanol, Docosanol and Docosenol available. As in fat chemistry common practice is to form Guerbet alcohols general formula II generally not pure Alkanols of the above list, but technical Mixtures of the same as those used with conventional oleochemicals Methods from natural fats and oils are available; particularly suitable starting materials of the general formula II are thus with technical alcohols such as Capron, Önanth, Capryl, Pelargon, Caprin, Lauryl, Myristyl, Cetyl, stearyl, arachidyl, behenyl, oleyl, elaidyl, Linoleyl, Gadoleyl, Arachidon, Eruca and Brassidyl alcohol receive. As can be seen from the above list, are suitable thus the manufacture of the starting materials for the The invention not only saturated, but also unsaturated fatty alcohols; possibly in the starting material The olefinic double bonds present in the course hydrogenated the process of the invention.  

As sulfonic acid groups that can be used in the context of the invention catalysts containing are in particular sulfuric acid, aromatic sulfonic acids and short-chain alkyl sulfonic acids, especially methyl, ethyl, propyl, butyl, pentyl and Hexylsulfonic acid to name. The dehydration takes place in a conventional manner for dehydration reactions by reacting the starting compounds of the general Formula II at elevated temperatures, the reaction at Compounds below the dehydration temperature already have a noticeable vapor pressure, preferably is carried out under pressure. The dehydration runs along great ease and with the formation of homogeneous reaction pro ducts; this is considering the fact that linear Alcohols practically only form ethers under these conditions and in acid catalyzed dehydration of primary Alcohols generally have significant amounts of by-products are considered to be surprising.

Suitable as hydrogenation catalysts in the context of the invention which are commonly used in olefin hydrogenation, in particular metallic catalysts based on Platinum, palladium and nickel or catalytically active verbin of the same. Nickel kata are particularly preferred analyzers, especially those based on a solid, inert Carrier material such as silicon dioxide, aluminum oxide, diatomaceous earth and the like are applied. The hydrogenation can Use of platinum and palladium catalysts at atmospheric pressure; In contrast, nickel catalysts require generally superatmospheric and / or elevated Temperatures.

According to an advantageous embodiment of the invention, C ₁ -C ₆ alkylsulfonic acids are used as dehydration catalysts, with methanesulfonic acid being particularly preferred. Furthermore, it has proven advantageous to carry out the dehydration in the presence of cocatalysts, a particularly suitable cocatalyst being hypophosphorous acid. The dehydration catalysts are preferably used in an amount of 0.1 to 5 and those under phosphorous acid in an amount of 0.05 to 5% by weight, based in each case on Guerbet alcohols used.

According to a further advantageous embodiment of the invention dehydration is carried out at temperatures of 150 to 300, in particular from 180 to 260 ° C. Before the on closing hydrogenation will be the products of Dehydration preferably neutralized with Bases such as sodium hydroxide solution, sodium carbonate, sodium bicarbonate, Potash lye and the like, and washed with water.

According to a further advantageous embodiment of the invention the hydrogenation is carried out at a pressure of 2 to 100, in particular from 2 to 25 bar and a temperature of 20 to 250, in particular from 150 to 240 ° C, through. Higher water pressures and hydrogenation temperatures within the first The areas mentioned are particularly recommended if when working with nickel catalysts.

The invention further relates to the use of methyl-branched paraffins of the general formula I in Ointment bases, especially in emulsion form, for cosme table preparations and as a lubricant and / or smoothing agent in the Textile technology.  

The invention is based on preferred from management examples explained in more detail.

A. Olefins of the general formula III from Guerbet alcohols of formula II.

Example 1. Dehydration of 2-hexyl-decanol-1

1000 g (3.75 mol) of a technical 2-hexyl-decanol-1 (hydro xyl number 210.5) with 5 g of methanesulfonic acid and 2.6 g hypophosphorous acid (50%) and mixed in one Distillation apparatus consisting of a three-necked flask with Thermometer, stirrer and distillation attachment, slowly to approx. Heated at 240 ° C. At approx. 160 ° C the water split off; to a total reaction time of about 8 hours was 68 ml of water distilled off (theory: 67.5 ml).

The crude reaction mixture was treated with 50 ml of 50% sodium hydroxide lye stirred for one hour at 90 ° C and then in one Separating funnel washed neutral. After drying at The colorless crude product was distilled at 100 ° C. and 14 hPa.

Use for distillation: 801 g
Distillate: 120 to 130 ° C / 7 hPa; 616 g
Distillation residue: <195 ° C / 7 hPa; 185 g.

Key figures of the distillate:

1.4445
Acid number 0.2
Saponification number 0.5
Hydroxyl number 0
Iodine number 120 (theory 102.2).

The amount of residue from the distillation is approximately the same Content of higher boiling parts in the starting material.

Example 2.

In the manner explained in Example 1, 2000 g (6.38 mol) of a technical 2-octyl-dodecanol-1 (hydroxyl number 179) with 20 g methanesulfonic acid and 4 g hypophosphorous acid (50%) heated. After 5 hours there were 118 ml of water deposited, i.e. the theoretical amount. The yield was 1870 g of crude product. The product was used as in Example 1 Sodium hydroxide solution treated and washed neutral.

A colorless liquid was obtained with the following Key data:

Acid number 0.4
Iodine number 94 (theory 86)
Hydroxyl number 0
1.4523
Viscosity (20 ° C) 6.6 mPa · s.

Example 3 Dehydration of a C _32/36 Guerbet alcohol

In the manner described in Example 1, 575 g (1 mol) of a technical Guerbet alcohol obtained by Guerbetisation of a technical palmityl / stearyl alcohol mixture was reacted.
Catalyst: 5.8 g methanesulfonic acid
Reaction time: 6 hours at 240 ° C
distilled water: 18 ml = 100% of theory.

After neutralization, the product was obtained as light discolored, pasty mass with the following characteristics:

Acid number 5.0
Hydroxyl number approx. 2
Saponification number 7.2
Iodine number 50.5 (calculated 45.4).

Example 4 Dehydration of 2-ethylhexanol.

In the manner described in Example 1, 935 g (7.2 mol) 2-ethylhexanol in the presence of 10 g methanesulfonic acid and 2.5 g hypophosphorous acid (50%) until reflux (184 ° C) heated. After 25 hours, 61.5 ml = 47.5% of the theoretical amount of water as an azeotrope with 2-ethylhexanol distilled off. The crude yield was 836 g.

By fractional distillation of the reaction mixture isolated from 500 g of the same 150 g of the corresponding olefin; the product had a hydroxyl number of 35 and an iodine number of 177.4 (calculated 227). Accordingly, 24.3% was 2-ethyl hexanol has been converted into the corresponding olefin. The Yield can be improved if you work under pressure.

Example 5

Analogously to Example 1, 1000 g (3.75 mol) of a tech African 2-hexyl-decanol-1 in the presence of 10 g of p-toluene heated to 240 ° C sulfonic acid. After 30 hours there were 57 ml (Theory 67.4 g) water distilled off.

Key figures:
Acid number 0.2,
Saponification number 3.4,
Hydroxyl number 0.4,
Iodine number 109.

Comparative Example 1.

For comparison purposes, dehydration was per se o-phosphoric acid known as a dehydration catalyst carried out.

Analogous to Example 2, 1205 g (3.8 mol) of a technical 2-octyl-dodecanol-1 (hydroxyl number 177) with 12 g of o-phosphorus acid heated to 240 ° C. In 6 hours there was only 9 ml Water distilled off (theory: 68.4 g).

Comparative Example 2.

This comparative example shows that the dehydration of Fatty alcohols in the presence of methanesulfonic acid and 1.5 g hypophosphorous acid mainly provides the dialkyl ether.

800 g (4.3 mol) of n-dodecanol (hydroxyl number 301) were added Add 8 g methanesulfonic acid and 1.5 g hypophosphorous Acid (50%) heated to 240 ° C for 6.5 hours; thereby destil 38 ml of water, i.e. 2.1 mol, from.

The colorless residue showed the following characteristics:

Acid number 0.4
Saponification number 7.6
Hydroxyl number 23.1
Iodine number 4.6.

As can be seen from the hydroxyl number and the iodine number the reaction mixture to more than 90% from didodecyl ether.

B. paraffins of formula I based on branched olefins of formula III.  

Example 6. 2-octyl-dodecane

905 g of the olefin obtained under A, Example 2 were in Presence of 4 g of a Ni-diatomaceous earth hydrogenation catalyst (Harshaw Ni 5136P) at a hydrogen pressure of 20 bar 200 ° C hydrogenated. After filtering off the catalyst, a obtain colorless oil with the following characteristics:

Acid number 0
Saponification number 6.6
Hydroxyl number 0.3
Iodine number 6.4
Pour point + 5 ° C
Viscosity (20 ° C) 7.3 mPas
1.4454.

Example 7. Methyl branched C _32/36 paraffin

575 g of the olefin obtained under A, Example 3, were as specified in Example 6 hydrogenated.

A pasty product with the characteristic data was obtained

Acid number 1.3
Saponification number 2.2
Hydroxyl number 1.8
Iodine number 4.3
Pour point 40 ° C.

The hydrogenation of the dehydration products according to the case play 1 and 4 is analog.  

Example 8.

Preparation of a W / E emulsion based on 2-octyl dodecan.

Component I

8 g of a commercially available W / O emulsifier (Dehymuls® F)
15 g petroleum jelly, white
8 g of 2-octyl-dodecane (according to Example 6).

Component II

3 g glycerin (86%)
0.3 g MgSO₄.7 H₂O
65.5 g water
0.2 g of a conventional preservative (Euxyl® K100)

The fat phase according to component I was ge at 70 to 80 ° C. melted at 75 to 85 ° C in portions with stirring the water phase II added; the emulsion was used until Cool to about 30 ° C. A homogeneous cream was obtained of good stability and with out for cosmetic purposes recorded properties.

Claims (12)

1. Methyl-branched paraffins of the general formula I R¹-CH (CH₂-CH₂-R²) -CH₃ (I) in the R ¹ and R ² , which are the same or different, in particular the same, straight-chain alkyl groups with 2 to 20, in particular 6 to 20 carbon atoms. 2. Process for the preparation of methyl-branched paraffins of the general formula (I) R¹-CH (CH₂-CH₂-R²) -CH₃ (I) in which R ¹ and R ² , which are the same or different, in particular the same, straight-chain alkyl groups with 2 to 20, in particular 6 to 20 carbon atoms, characterized in that Guerbet alcohols of the general formula IIR³-CH (CH₂-CH₂-R⁴) -CH₂-OH (II) in which R ³ and R ^{4 are} straight-chain, saturated or unsaturated Hydrocarbon radicals having 2 to 20, in particular 6 to 20, carbon atoms, in the presence of catalysts containing sulfonic acid groups, optionally under pressure, dehydrated and the alpha-olefins obtained of the general formula IIIR³-C (CH₂-CH₂-R⁴) = CH₂ (III) in which R ³ and R ^{4 are} as defined above, in the presence of hydrogenation catalysts, optionally under pressure, hydrogenated. 3. The method according to claim 2, characterized in that one uses C ₁ -C ₆ alkyl sulfonic acids as dehydration catalysts. 4. The method according to claim 2 or 3, characterized in that that methanesulfonic acid as a dehydration catalyst used. 5. The method according to at least one of claims 2 to 4, characterized in that hypophosphorous acid as Dehydration cocatalyst used. 6. The method according to at least one of claims 2 to 5, characterized in that the dehydration catalysts in an amount of 0.1 to 5 wt .-%, based on Guerbet alcohols used. 7. The method according to at least one of claims 2 to 6, characterized in that 0.05 to 5 wt .-%, based on Guerbet alcohols used, hypophosphorous acid used as a dehydration cocatalyst. 8. The method according to at least one of claims 2 to 7, characterized in that the dehydration  Temperatures of 150 to 300, in particular 180 to 260 ° C, carries out. 9. The method according to at least one of claims 2 to 8, characterized in that the products of Neutralize dehydration before hydrogenation with bases siert. 10. The method according to at least one of claims 2 to 9, characterized in that the hydrogenation at a Pressure from 2 to 100, especially 2 to 25 bar and one Temperature of 20 to 250, in particular 150 to 240 ° C, carries out. 11. Use of methyl-branched paraffins of the general formula I, in which R ¹ and R ^{2 are} as defined above, in ointment bases, in particular in emulsion form, for cosmetic preparations. 12. Use of methyl-branched paraffins of the general formula I, in which R ¹ and R ^{2 are} as defined above, as lubricants and / or smoothing agents in textile technology.