DE1024209B - Agent for the production of alkali-soluble polyamide coatings - Google Patents

Description

Means for the production of alkali-soluble polyamide coatings The invention relates to means for producing alkali-soluble polyamide coatings on the skin or hair.

The invention aims to create temporarily applicable protective coatings, which are both sufficiently resistant and elastic and at any time in simple Way can be removed by alkalis, especially soap.

It has already been proposed to at least use such coatings 90% acrylic resin solutions. These coatings had the Disadvantage that they were not very waterproof.

According to the invention it is possible to use protective coatings made of polyamide resins while practically maintaining resistance to water and chemical reagents to obtain such films, which, surprisingly, by means of aqueous alkali solutions, for example soap or soda, can be easily removed again.

This is achieved in that polyamide solutions according to the invention the polymers known per se as film-forming constituents of such agents or mixed polymers of such unsaturated hydrocarbons are added, their content of free carboxyl groups when aqueous alkali solutions are added Conversion into water-soluble form causes.

The proportion of polymers is expediently between 0, 5 and 50% the polyamide content selected. As copolymers are those of acrylic acid or Methacrylic acid with its esters or of acrylic acid with styrene or vinyl acetate suitable.

In most cases the proportions are such that the proportion of polymeric acids is equal to or greater than the proportion of esters or others Components of the copolymers.

According to a further feature of the invention, the polyamides and the Polymers in the form of ready-made solutions mixed with one another in the cold.

The surprising effect of the invention is that the on are waterproof and, according to the known, can only be removed with organic solvents Polyamide films with practically unchanged retention of their known per se Properties are alkali-soluble if the polyamide solution before application is proportionate small amounts of the polymers mentioned in acidic, ie not neutralized Form and with a sufficient content of free carboxyl groups are added. So it does not succeed, for example, by adding appropriate acrylic resins Cellulose derivative films to achieve alkali solubility.

Contrary to expectations, this can be carried out in a few seconds using alkalis Removal of the polyamide films according to the invention is presumably explained by the relatively high water absorption capacity of the polyamide resins, which is 12 to 14%. This allows the Alkali solutions quickly penetrate the film like a sponge and at the points of contact with the alkali-soluble acrylic resin components, points of dissolution create, making the entire film of lacquer similar to a stocking by running stitches is rolled up.

Fields of application of the invention are protective coatings on the human Skin, especially the hands, against dirt, harmful chemicals, 0l, organic Solvents such as ketones, gasoline, benzene; Furthermore, the coatings can be used as a carrier for medication or make-up paints on parts of the skin or hair or as a fixative for hairstyles (hair lacquer).

The polyamide films are on the skin because of their protein-like molecular structure and due to the net-like structure of the film particularly well tolerated, since the The extremely fine-pored film structure formed on the skin prevents skin breathing and evaporation not hindered, while varnish coatings, for example, hinder the skin from breathing and lead to heat build-up.

There are other possible uses of films according to the invention as a finish for textile fabrics that can be easily removed at any time, as a temporary protective layer, z. Bi during processing or during transport, on glass, wood, metals. Easily removable paints for advertising or camouflage purposes can also be used are made or coverings for sensitive foods, e.g. B. fruits, Cheese.

The properties of the protective layers according to the invention can by suitable additives to the polymers or copolymers or their solutions be influenced as desired. So can other film-forming substances, such as polyvinyl ether or polyvinyl acetate, also add plasticizers, thereby reducing the mechanical properties of the protective layer obtained in each case can be changed in a certain way.

The invention is explained using the following examples: example 1 A solution of 200 g of the polyamide resin, which is made from equal parts of caprolactan, Hexamethylene diammonium adipate and diaminodicyclohexyl methane adipate dissolved in 800 cc of 80% n-propanol on a reflux condenser.

At the same time, 30 parts by weight of a copolymer are obtained 1.7 parts by weight of methyl methacrylate and 3.3 parts by weight of methacrylic acid dissolved in 970 cc of 80% n-propanol in the heat.

After cooling, the two solutions are mixed together, and a clear viscous solution is obtained.

The films obtained by evaporation of this solution are as follows Properties: specific weight 1.12, tensile strength about 400 kg / cm2, elongation at break about 300 ° / 0, modulus of elasticity about 3000 kg / cm2.

In addition, the following special properties were found, which show that the known properties of the polyamide resins by the addition according to the invention practically no restriction on saponifiable polymers or copolymers suffer: The paint film according to Example 1 is resistant to the following chemicals : Concentration of the solvents formic acid ...................... 10 ° / 0 chloroacetic acid 10% chromic acid 10% chromic acid .............. 1% acetic acid ............... 10 % Lactic acid ...................... 10% oxalic acid ....................... 105 Phosphoric Acid 10 ° / 0 nitric acid 10 ° / 0 hydrochloric acid ...................... 10% sulfuric acid 10 ° / 0 superchloric acid ........... 10% citric acid 10 ° / o ammonia .............. 10% Potash lye ...................... 10% sodium hydroxide solution ............. 10 ° / 0 ammonium chloride ...... .. 10% aluminum chloride ........ 10 ° / 0 bleaching liquor .............. 10% calcium chloride ........... 10 ° / 0 chrome alum ............. 10 ° / 0 ferric chloride ............. 10% potassium dichromate ........ 5% potassium nitrate ............ 10 ° / 0 potassium permanganate ...... 1 ° / o copper sulphate ............. 10 ° / 0 magnesium chloride ........ 10 ° / o manganese sulphate ............ 10% sodium sulphate ............ 10 ° / o @ sodium bisulphite ............... 10% mercury chloride .............. 5% Hydrogen peroxide ..... 0.5% hydrogen peroxide ..... 1 ° / o after 54 days Hydrogen peroxide ..... 3 ° / 0 Storage Zinc chloride .............. 10% The paint film according to example 1 is resistant to the following solvents: isopropyl alcohol carbon tetrachloride Butanol trichlorethylene glycol perchlorethylene chloroform chlorobenzene methylene chloride Methyl acetate, ethylene chloride, ethyl acetate Buthylacetate decalin acetone tetrahydrofuran Benzene ether toluene benzaldehyde xylene pyridine gasoline carbon disulfide petroleum Mineral oil tetralin Instead of n-propanol, other lower Alcohols with an addition of 10 to 20% water can be used, for example Methyl or ethyl alcohol. The lacquer can also be blended in a known manner, for example with ethyl acetate. The application of the varnish can be done by rubbing, Brushing, spraying or dipping can be done.

Of course, plasticizers, for example dibutyl phthalate, Colorants, alcohol-soluble active ingredients, e.g. B. Medicines, as well as small amounts other film former can be added.

EXAMPLE 2 200 g of the polyamide resin which consists of the components caprolactam and hexamethylene diammonium adipate, in 800 ccm of 80% n-propanol. 40 g of that mentioned in Example 1 are also dissolved Methacrylic acid copolymer in 960 parts of 90% ethyl alcohol.

After cooling, mix the two solutions and add another 20 ccm Butylene glycol added. A milky, viscous product is obtained, which opposes the previous experience does not gel even after standing for weeks and its film does not show the phenomena of the so-called "water break".

The mechanical strength of the product is slightly higher than that of the preparation mentioned in Example 1, but the films are somewhat on drying clouded.

The solution of the two paint components is not expedient in one Operation carried out, as the acrylate solution can easily act in the heat on the polyamide solution can occur, which reduces the mechanical properties of the film.

The above-mentioned polyamide resins can be used in the same way with solutions of copolymers of acrylic acid or methacrylic acid or other unsaturated Acids, e.g. B. maleic acid, with other vinyl resins, such as polyvinyl acetate, Polyvinyl ether, polystyrene, can be mixed.

Characteristic for the essence of the invention is always the content of free carboxyl groups which, when alkalis are added, are converted into water-soluble ones Enable form.

The polymers used in the process according to the invention, Copolymers and solvents can be special depending on the desired Modify the properties of the films in a variety of ways.

Claims (2)

PATENT CLAIMS: 1. Means for producing alkali-soluble synthetic clay coatings on the skin or hair, characterized in that it is one from 662/3 to 991/2 ° / o one of equal parts of caprolactam, hexamethylenediammonium adipate and diaminodicyclohexyl methane adipate or from caprolactam and hexamethylene diammonium adipate existing polyamide resin on the one hand and from 331/3 to 1/2% of one as a component such agents known copolymers of acrylic acid or methacrylic acid with their esters or with styrene or vinyl acetate on the other hand mixture in 80% n-propanol or in another low water containing 10 to 20% Contains dissolved alcohol. 2. A method for producing the means of claim 1, characterized characterized that the poly amides and the polymers in the form of finished solutions mixed together in the cold. Considered publications: German patent application p 55669 IVa / 30 i.