DE1169064B - Coating agents that form films that can be easily removed again with water - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 09 d

Number: File number: Registration date: Display day:

German class: 22h-3

H 39372IVc / 22 h

May 7, 1960

April 30, 1964

The invention relates to coating agents which can be easily removed again by water, which are characterized in that they are copolymers of acrylamide and nitrogen with low Acrylamides substituted by alkyl radicals and, as solvents, water-containing lower alcohols contain. These coating agents advantageously contain copolymers of acrylamide and n-butyl acrylamide, especially N-tert-butyl acrylamide. Appropriate the film-forming coating agents with the addition of propellants for spray cans, z. B. of lower fluorocarbons.

It is advantageous to use those N-substituted acrylamides whose alkyl radicals have 2 to 6 carbon atoms contains. The following are, for example, possible substituents: n-propyl, i-propyl, η-butyl, i-butyl, tert-butyl, n-pentyl, i-pentyl, neo-pentyl, diethyl, methylpropyl and others. m. The copolymers to be used according to the invention can also contain several of the N-substituted acrylamides mentioned.

The quantitative ratio of unsubstituted to substituted acrylamide in the copolymers depends on the intended use and the constitution of the substituted acrylamide. With simple experiments it is possible without difficulty to find a product with the desired Establish solubility and other properties. Particularly favorable film-forming properties have copolymers of acrylamide and N-tert-butyl acrylamide, in which the ratio from unsubstituted to substituted acrylamide is 1: 1 to 3: 7. But it is also possible to use copolymers to be used with higher proportions of substituted acrylamide.

The copolymers mentioned are suitable for the production of coatings for various purposes for both rigid and flexible structures. They form clear, almost colorless films of good cohesion, which do not have any "crystalline" appearing parts and therefore do not appear scaly. The educated The film is not hygroscopic and hardly softens even in a humid atmosphere.

In spite of this, the films produced from the copolymers mentioned show an adequate one Solubility in water or with higher proportions of substituted acrylamides, such as tert-butyl acrylamide, good emulsifiability in water, so that the coatings can easily be removed again.

Another advantage of the products used according to the invention is the miscibility of their solutions in lower aliphatic alcohols with halogen films that can be easily removed again by water
forming coating agents

Applicant:

Henkel & Cie. G. m. B. H.,

Düsseldorf-Holthausen, Henkelstr. 67

Named as inventor:

Dr. Hans Zoebelein, Düsseldorf-Eller,

Dr. Manfred Dohr, Düsseldorf

hydrocarbons, ζ. B. methylene chloride and lower Chlorofluorocarbons. The said property makes the use of the solutions possible in aerosol spray cans. In the preparation of

In the case of alcoholic solutions for this purpose, it should be noted that usually small amounts of water should be added are to create a homogeneous solution of the copolymer in ethyl alcohol or isopropyl alcohol to reach. However, only enough water should be added to achieve good solubility so that there is no water separation when the propellant for the spray can is added he follows. With higher proportions of N-substituted acrylamide, e.g. B. butyl acrylamide, the water can be added also omitted.

example 1

The copolymers are produced in the following manner, which is not claimed here:

A solution of 15 g of acrylamide and 0.09 g of sodium pyrosulfite in 220 ecm of water and a solution of 30 g of N-tert-butyl acrylamide in 165 ecm of acetone are combined and added 0.09 g of ammonium persulfate polymerized in 20 ecm of water within 3 hours at 40 ° C. After finished In the reaction, a pale powder with a K value of 84 was obtained by drum drying. 16 g des The dry product was suspended in 170 ecm of isopropanol with stirring and 14 ecm of water given. A homogeneous, highly viscous solution resulted after a short time.

4 g of this solution together with 35.5 g of alcohol with the addition of 0.5 g of perfume with 60 g of dichlorodifluoromethane filled into an aerosol spray can. When sprayed, the solution provided a water-soluble, clear film of excellent quality Cohesion. Even in a humid atmosphere

■ ■ ■, 409 587/461

Claims (1)

3 4 this film is not unsightly and sticky. With kept. After this time the sheets were On the other hand, it was easy to remove water. blank. The film of the copolymer was with Example 2 ^ ⁰¹ " W ^ gen 40 ⁰ C warm solution of a tech- niche alkylbenzenesulfonate washed off, what without 15 g of acrylamide and 15 g of N-tert-butyl acrylamide .-> Difficulty was possible. were in a mixture of 165 ecm of water and one already has polyacrylamide as a component of Dissolved 50 g of acetone and proposed coating agents with a solution at 60 ° C. Next are mixed of 0.025 g of potassium persulfate in 30 ecm of water polymerized from acrylamide and methacrylamide occupied. After 2 hours of polymerisation it became known as well as its clear, colorless property Dry the resulting solution to form films on a heated io. However, they are only soluble in water get a light, pale powder. borrowed. The mixed poly- Of this product, 20 g in 250 ecm merisate with the addition of alcohol. Dissolved 90% ethanol. In contrast, the solution according to the invention as Detergent tablets of 50 g weight of the after-film formers in washable or rinsable following composition indicated dipped 15 coating agents to be used copolymers and air dried. significant advantages. Namely while the previous Tablet mixture known film formers only in the form of aqueous or _ ",,", ", Solutions containing predominantly water Tetrapropylbenzenesulfonate 5 _{% can be carried> are the invention according to m} Ferbc-rat ······ ■ · ■ · ■ ·· ■ ^{to / o} 20 copolymers used in any form Athylenoxyd-adducts _{nuschßa of water and} £ _{d "water-miscible} alcohols Can be applied to nonylpnenol i / o. They can also be mixed with water and with Soap IU / 0 any mixture of water and alcohol as- _Wash Natriumtnpolyphosphat Vo 45 _{from the} f _{Uelen respectively.} Carboxymethyl cellulose 1% Water glass 1% claims: Sodium sulphate 11 _{Vol L,} easily removable by water ^{Water equivalent to 0} film-forming coating agents, thereby This with a layer of the copolymer indicates that they are copolymers equal parts of acrylamide and N-terL-butylacryl- 30 from acrylamide and on nitrogen with low Amide-coated tablets also remained acrylamides substituted by alkyl radicals as well as Storage for 10 weeks in a humid atmosphere with solvents containing water-based lower alcohols 30 ° C dry and handsome. Included when thrown in. slightly agitated water dissolved the tablets 2. Easily removable with water quickly up. 35 film-forming coating compositions according to claim 1, Example 3 characterized by a content of mixed polymers made from acrylamide and N-butyl acrylic A solution of 30 g of acrylamide and 70 g of N-tert-amide, especially N-tert-butyl acrylamide. Butyl acrylamide in 650 ecm of water and 300 g of acetone 3. Easily removable with water was at 40 ° C with the addition of 0.1 g of sodium 40 film-forming coating agent according to claim 1 pyrosulfite and 1.3 g ammonium persulfate in the usual and 2, characterized by the addition of Copolymerized way and the resulting solution propellants for spray cans, z. B. of lower after 6 hours on a heated belt to a fluorocarbon. dried loose light powder. From the rea- tion product with the addition of 5 * / o thiourine was 45 Considered publications: substance, based on the copolymer, a 4% German Auslegeschrift No. 1006 151; Solution made in 95% ethanol. German Patent No. 964 902; Iron sheets of 4 × 12 cm prospectus from American Cyanamid Comp., dipped and allowed to air dry. Die Bleche New York, on polyacrylamide, June 1955, in particular were 12 weeks at 25 ° C in a humid atmosphere 50 or p. 13. 409 587/461 4.64 Q Bundesdruckerei Berlin