FI64807C - FOERFARANDE FOER FOERTJOCKNING AV EN LOESNING AV ETT FILMBILDANDE POLYMERMATERIAL - Google Patents

Description

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JgSA lBJ 01) UTLÄGCNINGSSKRIFT 64öU / C (45) Ta te IitU ny3r.;.:. · Lly 10 01 1904 P “tent” ^ air 3/14, G 09 D 3A8 (51) K * Jk.J / int. CLJ // e 08 K 5/09, C 08 J 3/10 FINLAND —FINLAND (21) I ^ Mnu ^ kunHW-PuunurafttaJnj 752830 10.10.T5 '* (23) Alkuptlvi — Gittljhtedij 10.10.75 (41) Tullut julkiMkil - Blivlt offuntllg 12.01.76 _ * (44) NAME Date of publication and issue. - Λ_ 0

Patent * och regirtentjrralaen 1 7 Subject matter uthfd och ui. * KrKtM pubiiond 30.09.03 (32) (33) (31) Requested «toikuus — Begird priority 11.10.7l 2l.01.75 United Kingdom-Storbritannien (GB) II222 / 7I, 03111/75 Proof samples ty-Styrkt (71) Lingner & Fischer GmbH, Postfach lllO, D-75Ö0 Biihl (Baden),

Federal Republic of Germany Förbundsrepubliken Tyskland (DE) (72) Heinz Herman Dickmann, Biihl (Baden), Dieter Hechenberger, Sinsheim-Eschelbach, Richard Krattner, Biihl-Neusatz, Federal Republic of Germany-Förbundsrepubliken lyskland (DE) (7) This invention relates to thickened solutions of film-forming polymers, in particular thickened adhesive compositions. This invention relates to thickened solutions of film-forming polymers, in particular thickened adhesive mixtures. Solutions of film-forming polymers are widely used as adhesives and varnishes. They can be applied by using a brush to obtain a thin film from the solution on the surface, or they can be applied by extrusion from a collapsible tube or scratch with a rubber nozzle or the like. But standard adhesive mixtures for liquid adhesives and varnishes have several drawbacks, namely their tendency to drain when applied to sloping or vertical surfaces and the tendency to form a stretchable thread. Liquid adhesive and lacquer mixtures tend to stretch into a thread or llama between the applicator and the brush device, be it a hand-held applicator, tube or bottle, when the device is lifted from the nun to be treated after application of the cloth. Stretching into a thread is detrimental because it makes it very difficult to brush neatly, which is especially important in modeling and small gluing jobs at home.

The present invention is based on the finding that standard liquid adhesives and varnishes can be improved by reducing their tendency to flow and form extensible fibers by adding a thickener or coagulant to the soot.

Although thickeners and coagulants are commonly used in many industries, the adhesive and varnish industry is special in that the types of solvents it uses are usually moderately polar solvents such as methyl acetate, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone and methyl isobutyl ketone. Standard thickeners and coagulants used in highly polar solvents such as water and non-polar hydrocarbon solvents are generally unsuitable for use in moderately strong polar solvents. As an example of thickeners used in adhesive mixtures based on non-polar solvents such as aromatic hydrocarbons, mention may be made of the calcium, barium, magnesium, cadmium and lead salts of C8-6g fatty acids and in particular stearic acid. Examples of thickeners used in strongly polar solvents, such as water-based adhesive compositions, are the alkali or ammonium salts of C12-22 * fat, especially sodium stearate.

We have surprisingly found that the addition of the sodium salt of c; L2_22 fatty acid, preferably dissolved in a lower aliphatic alcohol (e.g. methanol or ethanol) to standard type liquid lacquer and adhesive mixtures based on moderately strongly polar solvents, gives resulting in a thicker mixture that is less flowing and does not form stretchy filaments.

The invention thus provides a process for thickening a solution of a film-forming polymeric material selected from the group consisting of polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyurethane, polyacrylate or polymethacrylate, polyvinylpyrrolidone or a copolymer of the above-mentioned substances in a solvent of 0, characterized in that the following is added to said solution at a temperature higher than room temperature: a) the sodium salt of a C12-22 fatty acid, optionally as a solution of a lower aliphatic alcohol; and optionally b) a buffering agent to such an extent that the final pH of the whole composition can be adjusted to a range of 7.0-9.0 and the mixture is allowed to cool without substantially stirring.

The degree of thickening obtained is, of course, dependent on the concentration of the added fatty acid salt (hereinafter referred to as "soap"). The proportion of soap is usually 0.05 ~ 5% by weight of the total thickened mixture. The preferred soap is sodium stearate.

The soap is mixed with a solution of the film-forming polymer, preferably dissolved in a lower aliphatic alcohol, especially rr, ethanol or ethanol. The temperature at which the alcoholic soap solution is mixed with the solution of the film-forming agent may range from 3 ° C to 80 ° C, depending on the volatility of the solvents used. Sometimes it may be possible to form soap in situ by neutralizing the added fatty acid.

The solvent with a dielectric constant of 5.0 to 50.0 can be selected from standard type moderately strong polar solvents hitherto used as a mixture of adhesives and varnishes, namely low molecular weight esters and ketones and mixtures thereof, to which small amounts are sometimes added. quantities of lower alcohols. Examples of such solvents are methyl acetate, ethyl acetate, butyl acetate, dibutyl phthalate, cyclohexanone, acetone, methyl ethyl ketone and methyl isobutyl ketone. Methyl and ethyl alcohol can be added in small portions to these esters and ketones. The solvent is usually a mixture of several private solvents selected with the desired evaporation rate in mind. The dielectric constant is usually between 5.0 and 30.0, for example 10.0 to 25.0.

The film-forming agent may be one of those previously used in adhesive and varnish mixtures, for example polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyurethane, polyacrylate or nolymethacrylate or their esters, olivinylpyrrolidone, cellulosate, .

If desired, a small amount of water may also be added to the compositions of this invention, either as moisture normally contained in the organic solvent, or as added water. Thanks to water, the thickened or coagulated mixture acquires a beautiful, transparent appearance.

Although the compositions of this invention are generally satisfactory in that they have a lower tendency to flow and form a stretchable filament, we have found that in the case of some film-forming greens, e.g., polyvinyl acetate, especially aqueous compositions, the total thickened or coagulated mixture has a stability of somewhat weaker than the same mixture without soap or water, and that sometimes the adhesion to the metal surface may be worse. However, it can be seen that in cases where the Stability is unsatisfactory t "v", it is possible to add a buffer1 "! '' 1» which keeps the nli value of the mixture between 7.0-5.0 (preferably weak organ 4 64807 its or inorganic acid inorganic salts, for example, sodium salts such as sodium hydroxide (borax), sodium acetate, sodium p-hydroxybenzoic acid methyl ester, sodium iodide, sodium formate and sodium succinate. "R ^ lt; '" n 0.05-20% by weight of the total mixture (depending on the required nH value), restores Stability without adversely affecting the gluing or varnishing properties of the mixture, or only slightly degrading them. Buffering agent can be added saturated solution, aqueous or alcoholic solution or other solvent, however, it has surprisingly been found that these buffer additives, for example borax, sodium acetate, sodium p-hydroxy-benzoic acid methyl ester, also improve the adhesion of the mixture to the metal surface. of. Buffering agents also appear to increase the coagulation state of the compositions of this invention (possibly due to the "solution release salting effect" which reduces the solubility of the coagulant in its colloidal form).

In a preferred embodiment of the invention, the thickening of the solution of the film-forming polymeric substance is carried out when the dielectric constant of the solvent used is 5.0-50.0, so that a buffering agent is mixed into said solution so that the final pH of the total mixture can be adjusted to 7.0-9. , 0, and a fatty acid alkali metal salt, preferably as an alcoholic solution, and said fatty acid salt is mixed with a solution of the film-forming agent at a temperature above room temperature, and the solution is allowed to cool without vigorous stirring.

The buffering agent is most preferably added in an amount of 0.05-20% by weight of the total mixture so that the pH is adjusted to about 8. It can be added before, after or together with the alcoholic solution of the fatty acid salt. The temperature at which the buffer is added is most preferably room temperature or higher, and may be added as an aqueous solution or in some cases may be formed in situ by the addition of a weak inorganic or organic acid, followed by neutralization using, for example, sodium hydroxide.

64807

The following examples illustrate the invention:

Example 1 "Plexigum MB 319" 30% by weight (Rohm trademark, Darmstadt) co-polymer of polymethyl methacrylate and polyethyl acrylate

Methyl acetate 45 ”

Ethyl alcohol 24.7 "

Sodium stearate 0.3_ [μl] 100.00% by weight

Method:

Mix the methyl acetate and ethyl alcohol in a vessel fitted with a condenser and add Plexigum with stirring at room temperature. After about 1 h, the solution is homogeneous.

Now add sodium stearate and continue stirring for about 15 minutes at room temperature. Heat to 60 ° C and stir (about 15 minutes) until the mixture appears homogeneous. The finished batch is pumped into the tanks and the resulting mixture is allowed to cool.

Example 2

Polyvinyl acetate having a molecular weight of 130,000 33% by weight

Methyl alcohol 10 "

Methyl acetate 30 "

Ethyl alcohol 19.75 "

Sodium stearate 0.25 "5% aqueous borax solution 2 _" __ 100.00% by weight

Method:

From bacon methyl acetate and ethyl alcohol in a vessel fitted with a condenser. Add nolyvinyl acetate with stirring. After 2.5 h, when the solution appears to be homogeneous, add sodium 6 4 8 0 7 st stearate as a hot methyl alcohol solution, and continue to germinate the mixture for about 10 minutes until it is di anerized. Heat Nitt ~ ·· k o- • o. .

a mixture of about 60 ° C and 11% aqueous solution of borax, cooling the resulting mixture.

Example 3 linear, bonded polyurethane 20% by weight.

Λ Alkylphenol resin (Alresen DA109) 10 ”" et, ry 1 ethyl iketone 9 0 '

Canol 2 9.7 "

Sodium stearate 0.3 ~! __ 100.0% by weight

Method:

Pour the methyl ethyl ketone into a vessel fitted with a condenser; add polyurethane containing linear bonds with stirring.

After about 2.3 h, when the solution appears to be homogeneous, add the alkylphenol resin and continue stirring for 1/2 h. Then add the hot (50 ° C) ethanolic solution of sodium stearate with slow stirring and heat the entire mixture to about 60 ° C. When the solution is completely homogeneous, allow the resulting mixture to cool.

Claims (7)

7 6 4 80 7 A method for thickening a solution of a film-forming polymeric material selected from the group consisting of polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyurethane, polyacrylate or polymethacrylate, polyvinylpyrrolidone or a copolymer of the above-mentioned substances in a solvent of 5.0 , Characterized in that the following is added to said solution at a temperature higher than room temperature: a) the sodium salt of a C 1-22 fatty acid, optionally as a solution of a lower aliphatic alcohol; and optionally b) a buffering agent to such an extent that the final pH of the whole composition can be adjusted to a range of 7.0-9.0 and the mixture is allowed to cool without substantially stirring. Process according to Claim 1, characterized in that the proportion of salt of the added fatty acid is from 0.05 to 5.0% by weight of the total mixture. Process according to Claim 1, characterized in that the fatty acid salt is sodium stearate. ij. Process according to any one of the preceding claims, characterized in that the fatty acid salt is mixed with a solution of the film-forming polymer dissolved in a lower aliphatic alcohol. Process according to Claim 4, characterized in that the alcohol used is acetanol or ethanol. A method according to claim 1, characterized in that 0.05-20% of the total weight of the mixture is added to the buffer to adjust the pH to approximately 8.0. Process according to Claim 1 or 6, characterized in that the buffering agent is sodium tetraborate, sodium acetate, sodium p-hydroxybenzoic acid methyl ester, sodium iodate, sodium formate or sodium succinate.