DE2309375A1 - 4-(3,5-di-tert-butyl-4-hydroxyphenyl) butan-2-ols - useful as inters, polymer stabilisers and solvents - Google Patents

Abstract

Cpds. of formula (I) (where each R is H (prefd.) or an aliphatic gp.) are useful as inters. for dyes, pesticides and plastics stabilisers, are themselves useful as stabilisers (e.g. for poly-olefins and polyamides), and are specific solvents in the molten state. They can be prepd., e.g., by reducing the corresp. butan-2-one.

Description

4- (m, m'-Di-tert-butyl-p-hydroxyphenyl) -butan-2-ols The invention relates to the new 4- (m, m'-di-tert-butyl-hydroxyphenyl) -butan-2-ols.

There were the new 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ols of the formula in which the individual radicals R can be identical or different and each denotes a water torratom or an aliphatic radical, found.

The preferred end product I is 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ol.

The new substances can, in general, by known methods Reduction of the corresponding butan-2-ones.

The starting materials are 4- (m, m'-di-tert, -butyl-p-hydroxyphenyl) -butan-2-ones of the formula in which the individual radicals R can be identical or different and each represent a hydrogen atom or an aliphatic radical, are in question. The starting materials II can be prepared, for example, by the process described in German Auslegeschrift 1 192 206 by reacting 2,6-di-tert-butylphenol with α, β-unsaturated carbonyl compounds in the presence of a basic catalyst and an organic solvent. The production is expediently carried out according to the patent. ... ... (patent application P - OZ29 722) described process by reaction of 2,6-di-tert-butylphenol with 4-hydroxybutanone- (2) in the presence of a strong acid at elevated temperature.

Preferred starting materials II and correspondingly preferred materials I are those in whose formulas the individual radicals R are identical or different can and in each case an alkyl radical having 1 to 4 carbon atoms or in particular mean a hydrogen atom. The residues mentioned can still be carried out under the reaction conditions inert groups, e.g. alkyl groups, alkoxy groups each with 1 to 3 carbon atoms, be substituted.

A particularly advantageous starting material II for the production of the end products I is 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan 2-one. As further starting materials II come, for example, 4-methyl-, 3-ethyl-, thyl-, 1,4-dimethyl-, 1,3,4-trimethyl-4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-one into consideration.

In the case of using 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-one, the reaction by reduction can be represented by the following formulas: The reducing agent, advantageously hydrogen, can be used in a stoichiometric amount or advantageously in excess, preferably in a ratio of 1.2 to 3 mol of hydrogen, based on 1 mol of starting material II.

The reaction is usually carried out at a temperature of 0 to 2500C, preferably from 50 to 1900C, without pressure or under pressure, continuously or discontinuously carried out. If necessary, one uses inert under the reaction conditions Solvents such as alkanols, e.g., methanol, methanol, n-butanol; ethers such as diethyl ether; cyclic ethers such as tetrahydrofuran or dioxane.

The preferred reducing agent is hydrogen, usually in Presence of a hydrogenation catalyst in question. Preferred hydrogenation catalysts are generally one or more metals with an atomic number between 24 and 29. usually cobalt, copper, manganese and / or nickel catalysts, e.g.

corresponding sintered catalysts. The metals can be in the catalyst also be present in the form of their oxides and / or as a mixture with phosphoric acid. Beneficial Catalysts of the type mentioned contain between 3 and 30 wt.% Copper, 0.5 and 10% by weight of manganese and 10 and 80% by weight of cobalt or nickel, this may be added 0.1 to 5% by weight of phosphoric acid, based on the amount of metal.

The hydrogenation catalyst is usually in the implementation in a Amount of 5 to 30% by weight, based on starting material II, is used. He can be mixed with a carrier material suitable for the reaction, e.g. silicon dioxide, for Apply, the amount of catalyst expediently being 10 to 40% by weight of the mixture of catalyst and carrier.

As a rule, the reaction mixture at the beginning and in the course the reaction is supplied with such amounts of hydrogen that the reaction temperature a corresponding reaction pressure, expediently between 150 and 300 atm, is always set.

The reaction is generally carried out at a temperature between 80 and 2000C, preferably between 120 and 1900 C, discontinuously or continuously carried out. Inert gases such as nitrogen can also be used to adjust the pressure accordingly be used.

Cobalt or nickel sintered catalysts are also advantageous Can contain up to 30% by weight of copper, manganese, iron and / or chromium; preferably Raney nickel and Raney cobalt are used. Such hydrogenation catalysts are usually in amounts of 0.5 to 50 wt.%, based on starting material II, added. Hydrogen is used in excess, based on starting material II. The reaction takes place continuously at a reaction pressure between 50 and 300 atm or discontinuously, instead of; the reaction temperature is between 20 and 1600C, preferably between 120 and 160 ° C.

You can also carry out the reaction in the presence of palladium and / or its Compounds, generally in an amount of 0.01 to 5% by weight, preferably 0.1 Up to 2 total% palladium as finely divided metal and / or calculated as palladium in the form of its finely divided compounds, based on starting material II. For example, palladium black, palladium powder, Palladium bromide, arsenide, cyanide, chloride, nitrate, iodide, oxide, sulfide, sulfate or complex salts such as tetrachloropalladates, tetraamine or diamine palladium chlorides, Hexachloropalladates, can be used. The catalysts mentioned can be advantageous also in a known manner on a carrier, e.g. activated carbon, barium sulfate, silica gel or Applied zeolites and used such supported catalysts for isomerization will. The production of such supported catalysts can be in any way, e.g. by impregnating the carrier with appropriate solutions of the palladium salts Knead or mix while grinding the components. Regarding details the production of catalysts, especially supported catalysts, is based on Houben-Weyl, Methods of Organic Chemistry, Volume 4/2, pages 137 ff. In appropriate Platinum and / or its compounds, e.g. platinum oxide, can also be used as hydrogenation catalysts be used. The implementation is with Hydrogen, appropriate in an amount from 1 to 50, preferably from 5 to 25 mol%, based on the starting material II, carried out. The hydrogen can be used continuously or discontinuously feed the reaction and / or the catalyst itself after a certain reaction time reloaded freshly with hydrogen. The starting material II is usually used at a temperature between 20 and 200 ° C, preferably between 50 and 150 ° C, unpressurized or under pressure, e.g. is to 50 at, um.

Formic acid is also an advantageous reducing agent one in an amount of 1.5 to 10, preferably from 2 to 4 mol%, based on the starting material II, implements. The reaction is generally carried out at a temperature between 80 and 1200C, preferably between 90 and 1100C, without pressure or under pressure.

The reaction can be carried out as follows: A mixture of starting material II and reducing agent, optionally together with hydrogenation catalyst and / or Solvent, is for 4 to 24 hours, preferably in the hall of hydrogen as a reducing agent from 6 to 12 and in the case of formic acid as a reducing agent from 6 to 24 hours at the reaction temperature and optionally the aforementioned Reaction pressure held. The end product is then converted from the reaction mixture in the usual way Way, e.g. by fractional distillation.

In the case of formic acid as the reducing agent, this is expedient Alkali hydroxide solution is added to the reaction mixture, the organic phase formed is heated the binary mixture is separated and the end product is separated from it by fractional distillation isolated.

The 4- (m, m'-di-tert-butylp-hydroxyphenyl) butan-2-ols which can be prepared in the aforementioned manner I, especially 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ol, are valuable Starting materials for the manufacture of dyes, pesticides and plastic auxiliaries, especially stabilizers for polyolefins and polyamides. In the form of their melts, they are specific solvents for alkylphenols, e.g., 2,6-diethylphenol, 2,6-dimethylphenol, 2,4-dimethylphenol, and fragrances or components of odoriferous mixtures with a nuance of smell similar to that of blueberries, raspberries or blackberries.

Substances I themselves are also stabilizers and anti-aging agents or antioxidants for organic products that Lic t, by exposure to Heat, oxygen or ozone deforms, becomes brittle, discolored or in any other way be decomposed; such organic products are e.g. lubricating oils, heating oils, mineral oils, of vegetable or animal origin, waxes, soaps, fats, petrol, more natural and synthetic rubber, natural resins and plastics such as polyolefins, e.g. Polyethylene and polypropylene, and polyamides (see Example 2).

The substances according to the invention can by reaction with ammonia, e.g. at 80 to 1500C and a pressure of 50 to 110 at to the corresponding 2-amino-4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butanes, e.g. the unsubstituted 2-amino compound, are reacted; can accordingly also catalytic methods of amination of compounds containing hydroxyl groups be applied. Regarding the implementation of such aminations, reference is made to Houben-Weyl, Methods of Organic Chemistry, Volume 11/1, pages 112 ff., Referenced. The so obtained Amines are also stabilizers for polyolefins and polyamides. With respect to their Use is on patent. ... ... (patent application P - O.Z. 29 726).

The substances I can also be esterified by the usual methods, for example with corresponding carboxylic acids in the presence of acid or with acid chlorides and acid anhydrides, to form esters of the formula where R has the aforementioned meaning and R1 denotes an aliphatic, cycloaliphatic, araliphatic or aromatic radical, are reacted. With regard to methods of esterification, reference is made to Houben-Weyl, loc. cit., Volume 8, pages 516 ff., referenced. Preferred esters are those of the formula III in which R has the aforementioned preferred meaning, in particular the alcohol component is 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ol, and R1 denotes an alkyl radical with 1 to 20, in particular 1 to 6 carbon atoms, a cyclohexyl radical, an aralkyl radical with 7 to 12 carbon atoms, a naphthyl or phenyl radical. The esters III are valuable stabilizers for polyamides and polyolefins, and they are mixed with the plastics, for example in an amount of from 0.01 to 3% by weight. The addition can be made to the starting monomers of the polyamide before the polymerization, it can be carried out during the polymerization and it can be done by incorporating it into the finished polyamide. The stabilizing effect extends to all polyamides and copolyamides as well as polyamide mixtures of the known polyamide-forming compounds such as lactams, diamines and dicarboxylic acids and aminocarboxylic acids. Examples of polyamide-forming lactams that may be mentioned are pyrrolidone, caprolactam, capryllactam, oenanthlactam, aminoundecane lactam and laurolactam, which can be polymerized by the cationic mechanism alone or as a mixture. Polycondensates from diamines and dicarboxylic acids are, for example, those which can be prepared from aliphatic dicarboxylic acids with 4 to 18 carbon atoms and diamines with 4 to 18 carbon atoms, in particular polyamide 6,6 and 6,10. Uncolored polyamides are obtained which, even under high stress from heat and oxidizing influences, have greatly improved stability in their properties compared to conventional phenolic stabilizers. The stabilization is suitable both for polyamides that are used for the production of moldings and for those that are intended for the production of fibers and threads. The use of the stabilizers according to the invention is particularly suitable for colored polyamides, since their color values are not impaired. This is especially true for pigments. In addition, the polyamides can contain customary fillers, for example glass fibers, other polymers, lubricants, crystallization accelerators and other conventional additives and other additional stabilizers without disadvantage. Regarding the use of the esters mentioned, reference is made to the German patents. 0 0.O (patent application P - OZ 29 724) and. O .. 0§. (Patent application P - OZ 29 727) referenced.

The parts listed in the following examples are parts by weight.

Example 1 250 parts of 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-one are dissolved in 1,000 parts of methanol and placed in an autoclave with 50 parts of Raney nickel hydrogenated as a catalyst at 100 at H2 pressure and 1500C. After the reaction has ended the methanol is distilled off. The residue is then distilled in vacuo.

234 parts of 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) butan-2-ol are obtained boiling point Bp 01: 1360C, which corresponds to a yield of 93% of theory.

Example 2 Polypropylene is mixed with 0.2% by weight 4- (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ol, based on total weight, mixed and melted. The stabilized polypropylene is then rolled out to 1 mm thick plates, from which plates of size 15 x 40 x 1 mm can be cut out. The plates are hung in a thermal chamber, through which Lurt is constantly passed at 1400C. For comparison there are equal-sized platelets of unstabilized polypropylene in the chamber. The platelets are constantly moved by a mechanical device. In this aging test the decomposition of the polypropylene is tested under more stringent conditions. in the In contrast to the unstabilized polypropylene platelets, where after just a few Hours of decomposition are noticeable in the case of the stabilized polypropylene platelets no oxidative decomposition and discoloration found after 450 hours.

Claims (2)

Patent claims t (m, m'-di-tert-butyl-p-hydroxyphenyl) -butan-2-ols of the formula in which the individual radicals R can be identical or different and each represent a hydrogen atom or an aliphatic radical. 2. 4- (m, m'-Di-tert-butyl-p-hydroxyphenyl) -butan-2-ol.