DE1113562B - Process for the production of films or coatings from vinyl polymers containing aldehyde groups - Google Patents

Description

GERMAN

PATENT OFFICE

F28533IVb / 39b

REGISTRATION DATE: MAY 27, 1959

NOTICE 0ER REGISTRATION AND ISSUE OF EDITORIAL:

SEPTEMBER 7, 1961

It is known that macromolecular polymerization products of acrolein or copolymers of the Acroleins, which are mainly composed of acrolein, with alkali bisulphites or with aqueous sulphurous ones Convert acid into water-soluble products.

From the aqueous solutions of such adducts, on drying on substrates, films or coatings are obtained which become water-insoluble on drying. However, these products remain highly swellable in water because they still _{contain relatively tightly bound SO 3} H groups in considerable quantities. In order to counteract the embrittlement of such films or coatings, glycerine or other polyalcohols have already been added to the solutions in sulphurous acid as plasticizers. However, substances of this type do not prevent the gradual embrittlement during storage as a result of increasing crosslinking.

It has now been found that completely water-clear, pliable, no longer soluble in water and in The storage stability of largely improved films, coatings and the like can be obtained by using aqueous Solutions of addition products of sulfurous acid with acrolein polymers or acrolein copolymers mixes these solutions with high-molecular water-soluble polyglycol ethers on substrates spreads out and dries up. According to the invention, water-soluble polyethers are preferably used with hydroxyl and / or sulfhydryl end groups, their average molecular weight is at least 3000, better 15000 and more. Amazingly, such high molecular weight turned out to be Polyether as excellently tolerated, a fact that could not be foreseen in any way. At least one might have expected that when the solutions dried out, disturbances such. B. by Phase separation, occur. But it is obtained with very high molecular weight polyglycol ethers such. B. those with average molecular weights of 30,000 and above, excellent results.

Instead of the somewhat difficult to access, very high molecular weight homopolymer polyglycol ethers or their polymer-homologous mixtures can also be used polyethers that are chain-extended from polyglycol ethers of medium molecular weight, e.g. B. Average molecular weights of 15,000 to 30,000, with hooves known per se Linking agents, in particular di- or polyvalent acylating agents, were obtained. Linking agents that can be used for the production of such high molecular weight polyglycol ethers, are z. B. polyvalent isocyanates, acid chlorides, methods of manufacture

of foils or coatings

from containing aldehyde groups

Vinyl polymers

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning,

Frankfurt / M., Brüningstr. 45

Dr. Paul Schlack, Frankfurt / M.-Höchst,

and Dr. Wolfgang Göltner, Kriftel (Taunus),

have been named as inventors

Azlactones, also acylene-bis-lactams. Also through Transesterification of diaryl carbonates or dicarboxylic acid di-aryl esters with polyglycol ethers in the presence acidic or alkaline accelerators can be such high molecular weight water-soluble linear or moderately branched polyethers are obtained.

Water-soluble polyethers which carry hydroxyl or sulfhydryl groups at least at one end are preferred, the latter e.g. B. by reacting terminally hydroxylated polyglycol ethers with haloalkyl isocyanates, addition of thiourea and alkaline cleavage or by reacting the haloalkyl urethanes with alkali thiosulfate and subsequent mercaptan cleavage. The preferred terminally hydroxyl or sulfhydryl-bearing Polyäthylenoxyde are apparently in the formations mainly in chemical bonding before, because they can be made of the heat-dried fabrics, the reference sample stored at 65% moisture, for example, have a water content of about 8% ^aur ~, with water, only a small part of it is washed out even in the heat, on the other hand the water-soluble polyglycol ethers which can also be used according to the invention are without hydroxyl or sulfate. hydryl end groups, e.g. B. polyglycol ethers reacted with phenyl isocyanate, largely watered out under comparable conditions.
In addition to the particularly advantageous polyglycol ethers made from ethylene oxide, there are also water-soluble ethers, especially those with increased molecular weights due to linking agents of the type mentioned above

109 687 / 224-

Copolymers (block copolymers of ethylene oxide and other 1,2-epoxides, especially 1,2-propylene oxide) into consideration.

The amount of polyglycol ethers added can vary within considerable limits, e.g. B. between about 5 and 25%> preferably 10 to 15% are used.

To prepare the solutions can be solved the PoIyacroleine or the preferred acrolein copolymers in at room temperature and under atmospheric pressure, suitably a saturated aqueous sulfuric acid, depending on the viscosity and chemical composition comprises from about 8 to 22 ° / oig ^s solutions. In general, the more aldehyde groups are present in the polymer, the more concentrated solutions can be prepared under otherwise comparable conditions. The dissolution temperature is expediently between -10 and 30 ° C. If higher temperatures are used, it is more advantageous to carry out the dissolution under excess sulfur dioxide pressure. Of course, sulfur dioxide overpressure can also be used at normal temperature in order to accelerate the dissolution process.

The solutions are then mixed with separately prepared solutions of the polyglycol ethers in water. But one can also use the polyglycol ether, especially when highly concentrated solutions are to be prepared First distribute in the sulphurous acid and then the acrolein polymer in this mixture dissolve or mixed polymer. Since the sulfur dioxide adducts in sufficient numbers Sulphonic acid groups are already soluble in water alone, at least an excess of sulphurous acid in the case of a moderately concentrated solution and in the case of relatively aldehyde-rich polymers, this is not necessarily the case is necessary, you can in some cases also use aqueous solutions to dissolve the polymers use that contain only a little more than the theoretically required amount of sulfur dioxide. However In this case, the release process proceeds correspondingly more slowly. That is why it usually is more appropriate, with a considerable excess of sulfur dioxide, for concentrated solutions best with Sulfur dioxide saturation to work and then the excess, as far as the solution concentration this allows, from the solutions by passing gases such as air, nitrogen, carbon dioxide, and resp. or by applying negative pressure at normal or moderate, e.g. B. to 30 ° C increased temperature partially to be removed again. You can use the standard in the viscose industry, continuously operating ventilation devices.

The method of the invention is generally applicable to film-forming polymers and copolymers of acrolein, as they are, for. B. are available by radical-initiated polymerization. The process for copolymers, in particular with acrylic monomers, such as methyl acrylate, acrylic acid alkylamides, such as methyl acrylamide and dimethyl acrylamide, and in particular acrylonitrile, is significantly more advantageous than for acrolein homopolymers. Very suitable copolymers are those such as are produced by the process of German Patent 1,081,670 in the presence of activating metal compounds. This process gives particularly good results with copolymers with acrylic esters. Excellent results are also achieved with copolymers which, in addition to acrolein, contain essential, preferably predominant, z. B. 40% and more amounts of acrylonitrile polymerized and prepared by copolymerization in the presence of lower glycols as auxiliary solvents. Surprisingly, these acrylonitrile-rich copolymers are also extremely compatible with the water-soluble polyglycol ethers, even with very high molecular weight ethers. It is possible to obtain films with a sufficiently high degree of polymerization of the polyglycol ethers which contain quite considerable amounts of polyglycol ethers, e.g. B. 20%, without the good strength that z. B. 1000 kg / cm ² , would be affected by this addition.

The films or coatings obtained according to the invention with a high content of aldehyde-free components, especially acrylonitrile, are characterized by particularly good mechanical properties and, above all, by significantly reduced water sensitivity when drying is not at room temperature but at higher, appropriately gradually increasing Temperature, e.g. B. between about 70 and 130 ⁰ C, takes place. Has been used at room temperature or only moderately elevated temperature, e.g. B. dried under reduced pressure, a special thermal aftertreatment is appropriate. The temperature and the drying or heating time depend on the desired hardening effect and the reactivity of the material present in each case. The temperature level is not particularly critical, but it should be noted that above 150 ° C. yellowing can gradually occur. When choosing the working conditions for the thermal treatment or post-treatment, the amount of polyglycol ether added must also be taken into account. As the amount added increases, more intensive thermal treatment is generally indicated.

The method of the invention is versatile and practically applicable, e.g. B. for the production of packaging films, for sizing and finishing of textiles, for the production of light-sensitive layers or intermediate layers for photographic purposes, for paper finishing, for fixing pigments on substrates, for fixing pesticides in crop protection, for the production of clear panes for light protection films.

example 1

A suspension of 10 parts of a copolymer of acrolein and acrylonitrile (. N 16.1%; _η ΐβ ι = 1.42) in 90 parts of water was saturated at 20 ⁰ C under stirring with sulfur dioxide. After a temporary swelling, the copolymer gradually went into solution. The filtered viscous solution was then largely removed by evacuation at 25 ⁰ C of excess sulfur dioxide, added with 0.5 parts of polyethylene oxide of average molecular weight 20000 with stirring finally allowed to stand briefly to vent. The clear obtained at 2O ⁰ C by pouring the solution onto a flat substrate and 12 hours of drying, smooth and shock-resistant films exhibited a tensile strength of 700 kg / cm ² at 11% elongation at break. The sulfur content of this film was 1.8%> the water content 8.5% based on material conditioned at 65% relative humidity. After 30 minutes

When heated to 80 ° C., the film was resistant to boiling water.

Example 2

A 10% solution of a copolymer of acrolein and acrylonitrile (16.1% N; η _Τ βΐ. = 1.42), to which 0.5 part of polyethylene oxide with an average molecular weight of 20,000 had been added, was used to produce films poured. After drying for 35 minutes, the solution was dissolved with stirring and the solution was mixed with 100 parts of the copolymer solution prepared according to Example 1. After removing the excess sulfur dioxide under reduced pressure, the viscous solution was cast into films. These were dimensionally stable after drying for 75 minutes at 80 ^° C. in boiling water. The tear strength was 1043 kg / cm ² , the elongation at break 4%.
By extracting with cold water for 12 hours

gradually increased to 120 ⁰ C temperature had the io only 11% of the added Polyäthylenoxyds film were a tensile strength of 865 kg / cm ² at a dissolved. Elongation at break of 6%. The material was then resistant to boiling water and was easy to dye with basic dyes.

Example 8 Example 3

A 10% solution of a prepared according to the details of Example 1 according to the method of the German Patent 1,081,670 produced copolymers of acrolein and acrylic acid methyl ester 0? Rei. = 3.18; OCHg content 27.0%), the 5% polyethylene oxide on the average molecular weight

In a 10% solution of a copolymer of acrolein and acrylonitrile (16.1% N; r \ _te \. = 1.42) prepared according to Example 1, 0.5 part of polyethylene oxide with an average molecular weight of 20 20,000 (based on the copolymer) was dissolved, was 20,000. From this solution, which was cast by evacuation at to foils. After drying gradually at 25.degree. C., the excess sulfur dioxide had largely been removed, films were cast. After 70 minutes of drying at within 20 minutes

within 20 minutes of 20 increased to 120 ° C temperature for a further 50 minutes at 120 ⁰ C was cured. The film obtained showed a tear strength

to 12O ⁰ C increased temperature, the films were 25 of 478 kg / cm ² at an elongation at break of 15% ·

Boil-proof and resistant to common organic solvents. The tear strength was 1065 kg / cm ² , the elongation at break 6%

Example 4

A solution prepared as in Example 1 of 10 parts of a copolymer of acrolein and acrylonitrile (16.1% N; j? _Re i. = 1.42), the 0.5 part of polyethylene oxide of average molecular weight could be easily stained with basic dyes. After 8 weeks of storage, the film was still pliable and impact-resistant.

Example 9

A 10% solution of polyacrolein (η _ΐβ ι. = 1.78) prepared according to Example 1, produced by redox polymerization according to Schulz and Kern, Makromol.

20,000 were added, was on a flat plate 35 Chem., 24, p. 149 (1959), after the addition of 10%

poured out. After 75 minutes heating at 8O ⁰ C, the film obtained had a tensile strength of 925 kg / cm ² and an elongation at break of 6% · Add boiling water, the film was dimensionally stable.

Example 5

One part of polyethylene oxide with an average molecular weight of 20,000 was dissolved in 100 parts of a 10% strength solution of an acrolein-acrylonitrile copolymer (16.1% N; 77rei. = 1.42). The solution (viscosity 635 cP, measured in a falling ball viscometer according to Höppler at 2O ⁰ C) was largely removed by passing a weak current of carbon dioxide at 25 ° C under reduced pressure from the excess of sulfur dioxide and then cast into films. After 35 minutes, drying at elevated rapidly to 12O ⁰ C temperature resulted in a colorless, smooth, boiling-resistant and well-dyeable with basic dyes film (tensile strength 800 kg / cm ^2, elongation 6%) ·

Example 6

The procedure was the same as in Example 5 with the difference that a high molecular weight polyethylene oxide was used which had a 5% aqueous solution at 25 ⁰ C had a viscosity of 2000 cP, and the drying is not at 120 ° C, but at 8O ⁰ C was carried out (tear strength 968 kg / cm ² , elongation at break 4%)

Example 7

Part of the high molecular weight polyethylene oxide used according to Example 6 was poured into 4 parts of water polyethylene glycol with an average molecular weight of about 30,000 (obtained by increasing the molecular weight of polyethylene glycol ether with an average molecular weight of 20,000 with the aid of hexamethylene diisocyanate). The film, dried and post-heated as indicated in the previous example, showed a tear strength of 365 kg / cm ² at 8% elongation. After 4 weeks of storage, the material still showed no embrittlement.

Unless otherwise stated, the acrolein copolymers used in the preceding examples were prepared from acrolein and acrylic monomers under the influence of radical polymerization initiators in an aqueous medium in the presence of water-soluble glycols or glycol ethers or cyanohydrins. The values for the relative viscosity related to l% solutions in 10% ^e r aqueous sulfuric acid, measuring temperature 2O ⁰ C. Before the strength determination were each conditioned the films for 24 hours at 20 ° C and 65% relative humidity.

60

Claims (6)

PATENT CLAIMS: 1. A process for the production of films or coatings from vinyl polymers containing aldehyde groups, characterized in that aqueous solutions of addition products of sulfurous acid with acrolein containing at least a proportion of vinyl polymers, which also contain a minor amount of high molecular weight water-soluble polyglycol ethers, are spread on substrates and dried . 2. The method according to claim I, characterized in that water-soluble polyglycol ethers with Hydroxyl or sulfhydryl end groups can be used. 3. Process according to Claims 1 and 2, characterized in that water-soluble polyglycol ethers with an average molecular weight greater than 20,000 can be used. 4. Process according to Claims 1 to 3, characterized in that water-soluble high molecular weight Polyglycol ethers are used by Chain extension from water-soluble high-molecular polyglycol ethers with HiKe polyvalent Acylating agents were obtained. 5. Process according to Claims 1 to 4, characterized in that copolymers of acrolein with at least 40% acrylonitrile can be used. 6. The method according to claims 1 to 5, characterized in that the sheet-like structure according to the Removal of the solvent can be heated for a longer period of time.