DE812100C - Process for the production of condensation products with a tanning effect - Google Patents

Description

Process for the production of condensation products with a tanning effect The production of tanning agents from rosin encounters considerable difficulties. In the case of direct sulfonation, the necessary high "temperatures" occur and large excesses of the sulforating agent cause severe decomposition. l) ie received Tannins give dark and flat leather.

By adding phenols before or during the sulfonation one can Preserve tannins, their filling effect better and their color lighter and purer is, but their salt resistance and extract tolerance is mostly inadequate. In order to obtain useful tanning agents, it is necessary to make them low in electrolytes do what can be done by washing with water or saline solutions.

It has now been found that condensation products with a tanning effect can be obtained with very good properties if you use α- or β- \ aphtholsulfonic acid with Rosin and then with a condensation product of phenols and formaldehyde, optionally in the presence of free phenols, and the whole with formaldehyde post-treated. Brown tannins are obtained that cook a well-filled, tan Similar leathers which tan through quickly, when analyzed to the nearest 100 parts by weight, yield Dry residue up to 95 parts by weight of tannin show, even with high 1> I1 values retain their good tanning properties and in many cases leather of an excellent one Give yield and great strength.

One works expediently so that one z. B. N aphthol in sulfuric acid at temperatures between 8o and 12o ° and after the Sulphonation yields rosin at about the same temperatures. Since here If foaming occurs, the addition is to be regulated so that foaming over is avoided will. A reaction product of phenols is allowed to enter the reaction mixture obtained and formaldehyde, the so-called phenol alcohol, dilute the reaction mixture with water, it being expedient to cool it beforehand to a temperature below 100 ° is, and then treats it at a temperature generally above 95 ° with formaldehyde.

The quantities of substances used can vary within wide limits. The most favorable conditions can in any case without any particular difficulties can be determined by experiments.

Phenol alcohol is produced by converting phenols with formaldehyde in the presence of small amounts of acidic or alkaline condensation agents, such as B. sulfuric acid, glacial acetic acid, soda or caustic soda. It shouldn't be anymore than about 1 mole of formaldehyde for 1 mole of phenol. To speed up Temperatures of up to 100 ° can be used for the implementation.

The phenolic alcohols can also be obtained in other ways, e.g. B. by reacting phenol with methylene chloride, so one in this reaction the compound corresponding to the formaldehyde, in the presence of sodium hydroxide solution, if appropriate negative pressure.

Instead of phenol and cresol, their derivatives or crude Mixtures such as phenolic oils, cresol oils o. The like. Can be used. Instead of the subsequent The rosin can also convert naphtholsulfonic acids with rosin be present at the sulfation.

EXAMPLES 1. 100% strength sulfuric acid is carried in 280 parts by weight at 7o to 90 ° 28o parts by weight of ß-naphthol in powder form and at 9o to 100 ° 5o Parts by weight of rosin briskly with stirring. After completing the entry, it heats up the mixture is kept at 15 ° for a period of time, cooled to 95 ° and left under very low thorough stirring, 46o parts by weight of a liquid condensation product of cresol-phenol and formaldehyde. The mixture is then diluted with 80 parts by weight of water and condenses further at 95 ° with 150 parts by weight of 300% formaldehyde, the is diluted with 3o parts by weight of water.

The condensation product from phenols and formaldehyde is produced by adding a mixture of 16o parts by weight of phenol, 16o parts by weight of cresol, 14o parts by weight of formaldehyde and 0.7 parts by weight of anhydrous soda with stirring Heated to 80 ° for 3 hours.

The tanning agent is neutralized with aqueous ammonia and with Acetic acid brought to a degree of acidity that 1o g for complete neutralization 1o ccm of sodium hydroxide solution.

The tanning agent is clearly soluble in water, tans well and quickly, gives brown leather of good fullness and good standing and can be analyzed excellently.

2. The procedure is as in Example 1, but instead of cresol and phenol for reaction with formaldehyde used here only cresol.

The tanning agent has similar properties to that of Example 1 manufactured.

Claims (1)

PATENT CLAIM: A process for the production of condensation products with a tanning effect from condensation products of sulfonated naphthols with phenol alcohols, characterized in that naphthols are sulfonated and, at the same time or afterwards, rosin is allowed to act at an elevated temperature, the reaction mixture with a liquid condensation product of a phenol and formaldehyde or a compound corresponding to the formaldehyde, in which a maximum of 1 mole of formaldehyde has been applied to 1 mole of phenol, is reacted, optionally in the presence of free phenols, and the whole thing is aftertreated with formaldehyde at an elevated temperature.