NL7812529A - METHOD FOR PREPARING A POLYMER MIXTURE AND PRODUCTS PRODUCED THEREFROM - Google Patents

Description

N / 28863-Kp / ak - * 'r

Netherlands Organization for Applied Scientific Research for Industry, Trade and Traffic in 1s-Gravenhage.

Process for the preparation of a polymer mixture and molded products / obtained therefrom.

The invention relates to a process for the preparation of a polymer mixture / as well as to shaped products, such as foam, foils, fibers, granules, etc., obtained therefrom.

It has already been proposed to prepare highly swelling and / or moisture absorbing polymers of unsaturated carboxyl compounds, such as maleic anhydride, by polymerizing the carboxyl monomer with a cross-linking agent, such as a polyethylenically unsaturated compound, according to U.S. Pat. No. 2,798. .053 described method. Such polymers were used as synthetic gums in the preparation of tacky or gel-like aqueous mixtures.

It is known from British patent 1,200,106 that certain weakly cross-linked polymers with a large number of hydrophilic units can be used advantageously to absorb and bind liquids. Such polymers, which are little cross-linked, partially hydrolyzed polyacrylamides, have been recommended as constituents of the disposable diaper filler, bed filler or other such sanitary products because of their ability to retain significantly more aqueous liquid under pressure than when using an equal amount of cellulose fluff or the like. However, in certain applications of such highly water-swellable polymers, difficulties were encountered in retaining the polymer after it has been saturated with the aqueous liquid. It would be desirable to have a highly water-swellable, water-insoluble polymer in fiber form, as described in more detail in Netherlands Patent Application 74,01887.

Furthermore, Dutch patent applications 76.09583, 75.07186 and 75.05189 described water-swellable and / or water-absorbing materials obtained by other cross-linking reactions, e.g. between polyisocyanates and polyols. Furthermore, many moisture-sensitive or swellable plastics have been developed on the basis of water-soluble polymers such as e.g. polyacrylic acid, polyacrylamide and its derivatives, whether or not combined with naturally occurring hydrophilic polymers such as starch, cellulose and derivatives.

These materials are known as synthetic hydrogels. In many cases they are manufactured in the form of powders, fibers, granulate, films, etc. They are used for e.g. medical and sanitary purposes.

See in this regard Encycl. of Polymer Science and Technology, 15, 240-289.

These and many other water-soluble packing materials currently available have important drawbacks. In particular, the processability at high temperatures (e.g. 120-200 ° C), as usual in the processing of thermoplastic plastics, often presents great difficulties. This is especially true when polymers with reactive side groups are brought to a high temperature. Due to cross-linking reactions, the initial thermoplastic (behavioral) character is often lost, as a result of which continuous process management is also very difficult or impossible to carry out.

On the other hand, many hydrophilic polymers such as polyvinyl alcohol, cellulose, starch and derivatives usually have very high or no melting or softening ranges at all. Even then, the conventional thermoplastic processing techniques are not possible.

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In addition, cross-linking reactions also usually take place or dehydration occurs, whereby the original structures irreversibly change.

There is therefore a need for synthetic polymers with hydrophilic properties (according to starch, proteins, gelatin), which can be prepared and processed according to the existing thermoplastic process (extrusion, injection molding, film extrusion, calendering, etc.) without untimely irreversible changes or reactions occur during those processes.

The object of the invention is now to provide a process for the preparation of hydrophilic polymers, wherein the disadvantages of the comparable polymers are effectively eliminated.

To this end, the process according to the invention is characterized in that a high-temperature stable and homogeneous polymer alloy is prepared, which is mainly based on (a) one or more high molecular weight copolymers of an olefinically unsaturated monomer and maleic anhydride and ( b) one or more high molecular weight polymers of vinyl esters of low aliphatic monocarboxylic acids and / or copolymers with other vinyl monomers, first preparing a copolymer solution in an organic solvent, to which solution (b) in an amount of 2-98 wt. Depending on the amount of copolymer present, parts are added, with the copolymer present, before or after the addition of (b), being fully or partially protolyzed under the influence of protolysing agents, after which the solvent is removed.

The copolymers of olefinically unsaturated monomers and maleic anhydride included as component a) in the polymer alloy according to the invention form the main component thereof. Preferably, as such a copolymer of styrene and maleic anhydride is used, which product has long been known and extensively described in the literature (see, for example, RH Boundy, "Styrene, its polymers, Copolymers and Derivatives ", Reinhold Publishing Corp., New York, 1952, 860-865 and 5" Encyclopedia of Polymer Science and Technology ", Interscience Publishers, New York, Vol. 1, 81-85). This copolymer has a strong polar character, but is insoluble in water. Under the influence of water, however, depending on pH and temperature conditions, it changes to a water-soluble polymer in that free carboxyl groups or carboxylate ions are formed.

For the present purposes, the copolymer should have a molecular weight of at least 10.

Of the polymers of vinyl esters of lower aliphatic monocarboxylic acids included in the polymer compositions of the invention as component b), the use of polyvinyl acetate is preferred. There is extensive literature on this product, which has versatile application possibilities (see for example "Encyclopedia 20 of Polymer Science and Technology", Interscience Publishers,

New York, Vol. 15, pp. 577-663). The polymer, like the copolymer of styrene and maleic anhydride, has a polar character. However, it differs considerably in mechanical properties from the latter copolymer in that it is plastic or rubbery in character. For use in the method of the invention, the polyvinyl acetate must have a molecular weight of at least 1 µm.

The polymer alloys of the invention can be used to manufacture plastic materials with adjustable hydrophilic-hydrophobic properties which allow to control their water swellability and / or their moisture absorption.

Due to the presence of reactive groups, their properties can be easily modified.

It is of great importance that the polymer alloys according to the invention can be processed using the usual techniques for thermoplastic materials, such as extrusion, injection molding, calendering, foil blowing, melt spinning, etc.

It is noted that in general high molecular substances of different chemical structures are hardly, if at all, homogeneously miscible in all proportions.

10 (See, inter alia, Encycl. Of Polymer Science and Technology 2, 694-697). It is generally not possible to prepare homogeneous polymer alloys.

Surprisingly, it has now been found that high molecular weight SMA (a) and high molecular weight PVAc (b) are miscible in all ratios below certain temperatures. At a certain temperature, however, segregation or phase separation occurs. This is called the critical temperature T.

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This T '; depends on the mole. component weights O

and the mutual concentration relationships.

It has further been found that high temperature demixing (100-200 ° C) can be prevented by increasing the physical interaction (association of the polymer components.

This enhanced interaction can be accomplished by partial hydrolysis (general protolysis) of the copolymer, before or after the addition of b.

The manner of evaporation of the solvent or drying forms an important part of the present process. Namely, this should be done in such a way that the said enhanced interaction is maintained. The successive preparation methods are as follows:

First, a mixture of both polymers is prepared starting from a solution in, for example, butanone (methyl ethyl ketone). Previously, the copolymer is prepared separately via a so-called solution polymerization of an olefin, e.g. styrene and maleic anhydride, or dissolved as a ready polymer. After the completed polymerization to a given molecular weight. the polyvinyl acetate, either in solid form or also as butanone solution, is then added to this solution, then mixing takes place.

Although the concentration of the solution is not essential, a solution of about 20% polymer content is generally prepared for practical reasons. The applied solution technique is of great importance for obtaining an optimal degree of homogenization. By associating both polymer types a and b in the solvent, the alloy effect can be maximally and effectively achieved in a short time. The degree of association a ... b can then be increased by a secondary partial hydrolysis (protolysis) of the copolymer.

The solid homogeneous polymer alloy can then be obtained by a drying process in which the solvent is evaporated (distilled) in a closed system at temperatures between 100-200 ° C (usually 130-160 ° C).

The distillation or drying process can be accelerated by operating under reduced pressure (e.g. 10 - 500 mm / Hg). The drying process should be in a closed system for the following reasons: 1. recovery of the solvent; 2. the drying process must take place in an atmosphere with a certain degree of humidity. A complete "dry" environment should be avoided. It is namely

It is known that wholly or partially hydrated or hydrolysed copolymers are converted back into the cyclic anhydride configuration by water splitting (the reaction decreases). (In this regard, compare reaction scheme 1 of the reaction scheme sheet). As a result, the association becomes smaller again and phase separation can again occur. The drying

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The process should therefore proceed under very specific circumstances. Surprisingly, it has been found that under certain conditions during the drying it is not possible to obtain a decrease but rather an increase.

5 3. The drying process can also be combined with the hydration or hydrolysis reaction.

During the drying process, an increase in the water content takes place since butanone boils at 80 ° C and water at 100 ° C. There is a certain fractionation effect.

Combined with the rapid rise in temperature during the drying process, rapid conversion of anhydride groups to COOH groups in the closed system then takes place.

The relationship between the temperature and the quality of the resin proceeds as follows in the drying machine.

Temperature

50 80 100 120 150 17 ° C

20 resin solution clear - ^ cloudy - ·? clear 5 * dry final 20 C product at a T of h.v. 100 C „_…. . . . ,,. ο ^

J c H20 content increases by 170 C.

The Tc rises due to H 2 O reaction after 100 ° C.

7 5 4. Following on from point 3, it is clear that all kinds of attached substances with reactive functions, e.g. alcohols can be chemically bound during the drying process via residual anhydride groups. In this regard, see Reaction Scheme 2 of the Reaction Scheme Sheet, wherein J is a rapid higher temperature protolysis reaction in the apparatus during drying to yield a half-ester.

5. Naturally, the most diverse substances can also be added for the drying process; plasticizers, modifiers, auxiliaries, fillers, dyes, 78 1 25 29 8 lubricants, biologically active substances, etc.

The present polymer alloys have the following properties: thermoplastic, clear, density dail, 2-1.3 g / cm3, softening. processing temperatures of 100 - 200 ° C, excellent resistance to aliphatic hydrocarbons, oils and fats, soluble in lower alcohols, ketones, swellable in aromatic hydrocarbons.

The mechanical properties of the polymer alloys according to the invention depend on the molecular weights of the components and the mutual a / b ratio of the two polymers. Ex. High PVAc levels decrease the modulus of elasticity or increase the elongation at break (see Table A). The modulus (or stiffness) can be further reduced by adding plasticizers and / or other modifying agents. (see table B).

TABLE A

tensile test samples foils (polymer alloy); longitudinal strips (1.5 cm wide) from the samples. Clamping length 10 cm, pulling speed 3 cm / min., Thickness approx.0.1 mm.

Foil- Yield stress- Breakage- E-modulus Elongation at tension tension fracture theorem kgf / cm2 kgf / cm2 kgf / cm2%

& Si Si S

a / b-SMA / gem * S'A * 9em * S, A '9®m * ^ * A. avg. S.A.

PVAc _

Copol.no. 10 10/90 138 9 113 8 7000 2000 250 40 20/80 211 8 139 5 11000 1200 90 40 '30/70 425 15 410 80 17000 2500 6 3.0 40/60 - 487 4 15000 3000 2 , 3 0.2 78 1 25 2 9 * 9

Copol.no. 9 10/90 97.0 3.0 101 3 6500 2000 294 8 20/80 185 9 134.5 1 .5 10500 1300 220 25 30/70 343 9 201 10 16500 2000 35 9 5 40 / 60 - - 470 40 20 800 1200 2.6 0.3 SA = standard deviation

TABLE B

10

Influence of plasticizers; polymer ratio about 1: 1 (50/50); plasticizer content approx. 30%

Plasticizer code fracture stress yield stress E-modulus elongation at break is PPA 135 71 3000 220% SPA 133 152 5000 -59%

Polyethylene comparative material 150 120 2400 400% 20 'PPA = penta erythrito. 1 di-acetate di-propionate SPA = sorbitol triacetate tripropionate

The novel polymer alloys of the invention can be processed using conventional melt extrusion techniques and equipment or techniques for casting from organic solvents. Films can be manufactured according to known blown film techniques. Extrudate and granulate by conventional extrusion techniques.

Fibers can be manufactured by conventional techniques, e.g. monofilamet by melting dry spinning technique or wet spinning technique by direct coagulation from organic solvents in water or aqueous solutions.

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All new compositions of the invention have the advantage of being melt-extrudable as such or in combination with suitable plasticizers. By "suitable" is meant those substances which are sufficiently compatible with the polymeric mixtures and which do not give rise to undesired exudation, phase separation, reactions, etc.

The polymeric material is characterized by the simultaneous presence of hydrophobic and hydrophilic groups.

This is manifested, inter alia, in swelling phenomena, particularly in water.

The polymer alloy also has the properties of polyanhydride resins; due to the presence of the anhydride group, the alloy is also reactive in solid form, allowing for secondary chemical conversions.

Reactions are e.g. possible with water, alcohols, ammonia, amines, epoxy compounds, etc. It is clear that in this way (secondary reactions) very many modifications are possible in terms of both chemical and physical properties. Both the hydrophilic and the hydrophobic properties can thereby be strengthened or weakened.

Very particularly in this respect the reaction with water applies. The polymer alloys are stable under dry conditions. In general, this can also be said when material is stored under normal atmospheric conditions in terms of temperature and relative humidity (50-60%).

With prolonged exposure to air of high humidity or by direct contact with water, a gradual conversion of the anhydride group to the free dicarboxylic acid configuration takes place. The polarity (hydrophilic character) thereby increases with a simultaneous increase in the modulus (brittleness) measured under dry conditions.

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By converting the polyanhydride to polyacid or polyelectrolyte, the material acquires the properties of a stable hydrogel. The degree of swelling in water depends on the degree of ionization of the polymer-5 alloy (polymer ratio) and the pH of the aqueous medium. Maximum swelling occurs e.g. at pH 6-8, and minimal swelling at pH 2-3 (in buffered solution). This phenomenon is reversible and comparable to the known water behavior of proteins such as gelatin, keratin, etc.

The hydrogel therefore has the characteristic properties of a polyelectrolyte and can, for example, also function as an ion exchanger in the hydrogel form, e.g. bonding of polyvalent metal ions, such as Ca, Cu, Zn and Cd. The hydrogels and xerogels produced from the polymer alloy by hydrolysis are stable due to the strong interaction of the polyvinyl acetate with the hydrolysed or ionized copolymer component.

Very rapid conversion of the polyanhydride polymer alloy to a hydrogel polyelectrolyte can be accomplished by strong bases NaOH, KOH etc. and in particular by ammonia, ammonia-water solutions, organic amines. Cross-linking reactions occur by reactions with bi- or polyfunctional compounds, for example glycols, di- and polyamines etc. The degree of swelling of the hydrogels can be varied by modification as a result of reactions with both mono and polyfunctional reactive compounds.

The polymer alloys according to the invention can serve for the manufacture of synthetic products with various properties.

The shape of the material can be: foil, granulate, fiber, powder and other forms known in the processing of polymeric materials. Of particular interest is the conversion by water to substances with hydrogel properties (or polyelectrolyte properties).

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Of particular interest is the use of fibrous or powdered material in the polyelectrolyte or salt form for absorbing moisture. Furthermore, the use of secondary shaped hydrogels as an ion exchanger may have been used in conventional methods.

As already explained, the polymer compositions are swelled by water after reaction with ammonia, inorganic and organic bases.

As a result, the polymer alloys are particularly suitable for producing polymer compositions for the regular release of active ingredients, in particular under the influence of water. Both the rate and the degree of swelling affect the release rate of the active ingredients, which allows the release to be controlled. Naturally, the release rate also depends on the shape and size of the polymer mixtures (granulate, powder, foils, fibers, etc.). Examples of active substances are insecticides, fungides, herbicides; general; biocides, pheromones, etc. repellents to combat pests, plant diseases or damage to plants by insects and / or other harmful organisms. Controlled release of pharmacologically active substances is also possible.

If the polymer alloys are prepared in fiber form, after secondary conversion, they can be converted into fibers with strong swellability or moisture absorption in water by treatment with ammonia, amines, strong bases, etc.

The finished water-insoluble, water-swellable fibers are suitable for many purposes. Firstly, these fibers can be used in the manufacture of absorbent layers for sanitary products.

The above application can also be carried out in foil form, films of thin sheets or strips, etc. 35 78 1 25 2 9 13

The swellability or absorbency depends in the first instance on the mutual relationship of the two polymers in the polymer alloy. Higher copolymer concentrations increase swellability after secondary hydrolysis and / or ionization to hydrogel structures.

In addition, fillers such as carbon black, chalk, fibers, etc. may be added during the preparation of the present polymer alloy.

The addition of a foaming agent during the preparation can also be advantageous for obtaining porous structures.

EXAMPLE I

Preparation of the copolymer SMA in methyl ethyl ketone as a solvent (i.e. solution polymerization). 15 In a kettle with a capacity of about 50 l are successively mixed: 30 l (25 kg) methyl ethyl ketone (butanone), 3120 g styrene, 3000 g maleic anhydride, 7.5 g azo-bis-isobutyronitrile (catalyst) .

20 -The boiler is equipped with a heating jacket, stirrer, thermometer and thermal protection. With continuous stirring, the contents are heated and kept at a certain temperature for a certain time.

Heating schedule for example: 25 heating up to 60 ° C 1 h constant at 60 ° C 2 h constant at 70 ° C 1 h constant at 80 ° C 3 h total polymerization time approx. 7 h 30 "viscosity approx. 450 contipoises solids content approx. 20% critical demixing temperature T = 41 ° C (measured c with PVAc solution; see example II).

The degree of polymerization can be varied by changing the catalyst concentration and reaction temperature.

The approximate molecular weight can be determined from measurements of the intrinsic viscosity. (J; or Appl. Polym. Science 20, 1619 (1976).

4.5 mol. Wt. usually m = 10 - 10 5 10000 - 100000 '

The solid polymer can be obtained by evaporation of the solvent or by precipitation in excess methyl alcohol.

EXAMPLE II

- Partial or partial hydrolysis of the copolymer in solution. Partial hydrolysis to increase the critical demixing temperature T.

The critical demixing temperature Tc is a phase-15 transition temperature and is measured by mixing approx.

equal parts of a 20% copolymer solution and a 20% polyvinyl acetate solution (M70; Hoechst). The T can be determined by heating this mixture. At the T the mixture suddenly becomes cloudy due to separation w 20 (according to melting point, boiling point determination).

After the polymerization reaction of Example I has ended, the resin solution is added: approx. 33 g of water with good stirring (water content, so in total approx.

1%). The resin mixture is kept at ca.

25 75 - 80 ° C heated. The critical demixing temperature Tc has then risen from 41 ° C to approx. 100-110 ° C. The rate of hydrolysis and thus the rise of the T. depends on the reaction temperature and the water concentration.

(Example: at about 20 ° C, the above-mentioned conversion takes about 40 days. At 2% water content and 75-80 ° C, the conversion to T = 100 ° C takes about 8 h).

c -

EXAMPLE XII

Preparation of the polymer alloy; (30-70 ratio).

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Si 15

Mix in a 50 L vessel (kettle): 10 kg of the 20% copolymer solution of Example II (i.e. approx. 2 kg copolymer in solution), 19.6 kg of methyl ethyl ketone (MEK), 4.66 kg of polyvinyl acetate ( commercial polymer) Mowilith - 70 (Hoechst). The PVAc (M70) is a suspension or pearl polymerisate from Hoechst (Frankfurt).

The (solid) polyvinyl acetate is dissolved to a clear solution with slow stirring.

10 Mixing temperature approx. 15-20 ° C.

Total polymer alloy solution 33.30 kg.

Solid content 20%.

The mixing ratio SMA / PVAc = 30/70.

It is of course possible to carry out the mixing with certain polyvinyl acetate solutions in MEK. Pre-dissolved PVAc has the technical advantage of rapid mixing with copolymer solutions.

It is clear that, according to Example III, all desired polymer ratios can be quickly achieved.

The drying process:

About 1000 kg of the polymer alloy of Example III was dried using a technical dryer (Filmtruder Luwa). Previously, about 2 kg of stearyl alcohol (lubricant) (C 1 / 2H-2 OH) was added with stirring.

Of course, other corresponding drying devices can also be used.

Before drying, all kinds of substances can be added to the polymer alloy solution (if desired): plasticizers, lubricants, stabilizers, modifiers, biologically active substances, dyes, fillers, etc.). For example, in Example IV, stearyl alcohol is added to improve the extrusion properties (lubricant) of the dry polymer alloy.

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EXAMPLE IV

The following drying tests are carried out with the Filmtrud.er Luwa mentioned in Example III:

Trial No. input temp. vacuum yield solid appearance 5 kg / h jacket mm Hg polymer alloy polymer- in kg / h. alloy 1 75 + 160 ° C 300 17 cloudy 2 60 + 16o ° C 400 14 slightly cloudy 3 60 + 180 ° C 400 15 clear 10 4 50 + 180 ° C 500 12 clear 5 75 + 180 ° C 200 18 slightly cloudy

The solid content of the extrudate is about 98%.

The original Tc is approx. 100 ° C.

15

Additional 1% water was added to about 1000 kg resin mixture of Example III, after which heating was continued for 2 hours at 70-80 ° C with stirring. The critical temperature Tc therefore rises to> 140 ° C.

20 Trial no. input temp. vacuum yield solid appearance kg / h jacket mm Hg polymer alloy polymer- in kg / h alloy optimal - 6 75 + 160 ° C 300 16 clear 9t- too far - 7 60 + 190 ° C 200 15 slightly cloudy (T drops again) ( f veJ.

c dried)

From these examples it is clear that only under certain conditions the clear homogeneous polymer alloy is obtained.

EXAMPLE V

Starting from the polymer alloy solution of Example III, drying tests were also carried out with a closed roller dryer of much smaller capacity, developed by 35 in-house. Horizontal installation two rollers with screw.

Input approx. 7 kg / h (Solution 20%) jacket temperature 140 - 150 ° C 5 vacuum 300-400 mm / Hg yield polymer alloy approx. 1.5 kg / h. appearance slightly cloudy

The polymer alloy is obtained after exit as a continuous extrudate with a solid content of about 98-99%. Residual moisture content 0.5-1%. The extrudate can be granulated immediately after cooling,

EXAMPLE VI

Test with polymer alloy solution with a T of 80 ° C.

15 °

A polymer alloy solution prepared from copolymer solution according to example I and polyvinyl acetate M70 in the ratio of 30:70 is introduced into the drying apparatus. Dried under conditions according to test 5 of example IV. The extrudate is now completely white, opaque and of heterogeneous composition (phase separation of the polymer components).

EXAMPLE VII

Test for proof of Tc increase during drying (homogeneous end product).

To the copolymer solution of Example 1

2% water is added (total) and the mixture is heated at about 80 ° C for 8 h. The T is now approx. 90 ° C. Then c is mixed with polyvinyl acetate and methyl ethyl ketone; polymer-2q ratio 50/50.

• The TNO machine is dried under the conditions of:

input 5 kg / h temperature 150 ° C

25 vacuum 400 mm yield 1 kg / h 78 1 25 2 9 ν '18 appearance colorless-light yellow, clear.

Properties of the solid polymer alloy density 1.2 - 1.3 E modulus depending on moisture content and composition 2000 - 10000 kgf / cm2 (tough-hard).

The granulate can be processed in normal degassing extruders (twin screw) with which the remaining moisture content or solvent can still be reduced.

Thermal stability: 1 § 2 hours at 150 ° C: 10 slight increase in viscosity.

1 hour at 190 ° C: slight cross-linking, color remains pale yellow.

At high humidity 100% RH moisture absorption; at 30/70 polymer alloy about 5%.

15 In boiling water after 1 hour approx. 10%. The material is stable under normal conditions and permanently thermoplastic.

EXAMPLE VIII

Blown film preparation (from polymer alloy ^ + plasticizer).

A polymer alloy solution is prepared according to the described methodology, consisting of 50-50 ratio (1: 1) = = SMA / PVAc polymer. Tc of the polymer alloy solution is greater than 120 ° C. Before drying, about 10% glycerine triacetate is added, based on the dry matter content. After drying according to example V, granulate is obtained, with which blowing foil is prepared according to the existing technique.

Film properties: 30 film thickness 50-60 γ., Clear, E-modulus 2000-3000 kgf / cm2, elongation 200-250%, breaking stress + 100 kgf / cm2.

The elasticity of the polymer alloy foils is highly dependent on the moisture content of the material and / or the environment. Moisture sensitivity can be controlled according to methods described by the nature of the plasticizers, modifiers, etc.

EXAMPLE IX

As an example VIII. Polymer ratio 30/70. Plasticizer 5% dibutyl phthalate (polymer based j.

EXAMPLE X

Fiber preparation (wet spinning method)

A polymer alloy solution is prepared in butanone; solid content of the solution ca.

40%; viscosity of the solution 35000-40000 cps.

According to existing techniques and methods, the polymer alloy solution as a spinning liquid is spun wet by spraying in water as a coagulation bath at about 20 ° C.

The spinneret had 15 orifices of diameter 0.05 thick. The sprayed-out solution forms threads in a so-called monofilament form, which can be wound continuously.

The bundle obtained had about 5-8 dtex (gr / 10000m) after conditioning at 65% R.V. (relative humidity) and 20 ° C moisture content 2-3% (dtex = measure of fiber thickness).

EXAMPLE XI

Melt spin test.

The granulate obtained in Test 7 is a fiber-shaped polymer alloy obtained by existing melt spinning techniques in a suitable (existing) equipment. The fibers can be ionized (saline) by treatment with ammonia or organic amines to obtain a high water uptake capacity depending on the polymer ratio.

Swelling capacity e.g. from 100 per gram to 10 per gram in deionized water.

The fibers have the properties of ion exchangers in salt form (ion form).

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EXAMPLE XII

To 10% polymer alloy solution in buta-non according to example III are added: 10% chlorphenvinphos (Birlane) concentrate (Shell) insecticide, based on the solid polymer content 5, and then dried under conditions described in example IV no. 3. 1, 6 kg of dry extrudate, which is then granulated. Some of the grains are ground into powder. Both the granules and the powder can be used as a pesticide, e.g. soil min-10 secticide. The release rate of the active agent can be controlled inter alia by partial or total ionization of the polymer alloy, e.g. by water, ammonia, bases or other protolytic substances.

15 'EXAMPLE XIII

Hydrogel preparation

Polylloy material produced according to Run 4 (No. 3, 4 or 6) can be converted into a solid hydrogel by dilute (1% ammonia) or other bases. Ex. + 4g of extrudate (plate approx. 4 x 2 x 0.5 cm) is immersed in 1% ammonia solution for approx. 24 hours. Pre-swelling approx. 24 hr.

The swelling is then continued in neutral water. The water is changed to maximum swelling (end pH 7.0-7.5).

25

Stable hydrogel, maximum swelling in neutral water approx. 25-30 x original dry weight, hydrogel water content approx. 96-97%. (30/70 polymer alloy). "(At higher copolymer concentrations of the original polymer alloy, higher swelling degrees are achieved, e.g., 50-100x).

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Claims (11)

1. Process for the preparation of a polymer mixture, characterized in that a high-temperature stable and homogeneous polymer alloy is prepared, mainly starting from 5 (a) one or more high molecular weight copolymers of an olefinically unsaturated monomer and maleic anhydride and (b) one or more high molecular weight polymers of vinyl esters of lower aliphatic monocarboxylic acids and / or copolymers with other vinyl monomers, first preparing a copolymer solution in an organic solvent, to which solution (b) in an amount of 2-98 parts by weight, depending on the amount of the copolymer present, are added, the copolymer present being partially or fully protolyzed before or after the addition of (b) under the influence of protolysing agents, after which the solvent is deleted. 2. Process according to claim 1, characterized in that water is used as the protolysing agent. 3. Process according to claim 1 or 2, characterized in that the solvent is removed by evaporation in a closed system at 100-200 ° C, whereby a certain degree of humidity is guaranteed during evaporation and the solvent is recovered. 4. Process according to claim 3, characterized in that the removal of the solvent takes place at 130-160 ° C, at a reduced pressure of 10-500 mm / Hg. 5. Process according to claims 1-4, characterized in that as component (a) styrene-maizeic anhydride is used and as component (b) 78 1 25 29 4. 22 A polyvinyl acetate each with an M of at least 10. 6. Process according to claims 1 - 5, characterized in that an additional component and / or material is added during the preparation. 7. Process according to claim 6, characterized in that an active ingredient, such as insecticide, fungicide, herbicide, etc., is added as an additional component. 8. Process according to claim 6, characterized in that as an additional component a reactive component is added for modifying the polymer alloy during the preparation. 9. A method according to claim 6, characterized in that a foaming agent is added as an additional component. 10. A method according to claim 6, characterized in that a filler such as carbon black, chalk, fibers, etc. is added as an additional material. 11. Molded product, such as films, fibers, granules, etc., obtained from the polymer alloy, whether or not by modification during or after the preparation, prepared according to claims 1-10. 25 30 78 1 25 29 35