WO1994025521A1

WO1994025521A1 - Polymer compositions and their production, in particular absorbent materials, and their use

Info

Publication number: WO1994025521A1
Application number: PCT/EP1993/001062
Authority: WO
Inventors: Uwe Günther; Helmut Klimmek; Helmut Brüggemann
Original assignee: Chemische Fabrik Stockhausen Gmbh
Priority date: 1992-03-05
Filing date: 1993-05-03
Publication date: 1994-11-10

Abstract

A polymer composition and a process for producing the same are disclosed, in particular an absorbent material substantially consisting of a special component A based on renewable polysaccharide raw materials, a special component B consisting of a water-swellable polymer, a matrix material, an ionic and/or covalent cross-linking agent or an antiblocking agent. In order to produce said composition, the water-swellable polymer is mixed with the polysaccharide polymer, they are then dried and ground, the other components are added until an homogeneous mixture is obtained, the mixture is thermally treated and when a cross-linking agent is added, it may be fixed in the matrix after the thermal treatment by an additional thermal treatment process. Also disclosed is the use of said polymer composition, as well as hygiene articles (for animals) and technical chemicals containing said polymer composition.

Description

Polymer compositions, manufacture of polymer compositions, in particular absorption materials and their use

The invention relates to polymer material compositions and the production of a polymer composition and, in particular, absorption materials which are based predominantly on renewable raw materials and are therefore in principle also biodegradable. Due to the predominantly native origin, the absorbers contain no or significantly smaller amounts of residual monomers than polyacrylate-based absorbers. The absorbers according to the invention have a comparatively high absorption capacity and speed, even under pressure, for water and aqueous solutions, show no tendency to gel blocking (gel blocking: when in contact with water, the outer layers of the absorber stick together and prevent another Penetration of the liquid into the absorber) and are mechanically stable (with respect to the separation into the individual components). When swollen, they separate into individual particles, they are not aqueous and have a very high gel stability. The invention further relates to a process for their production and their use as fiber, film, powder or granulate for the absorption of water, aqueous solutions or aqueous dispersions and body fluids, in hygiene agents such as tampons or diapers and animal hygiene articles, in chemical -technical products such as packaging materials, in particular for meat and fish, in culture vessels and for soil improvement and as cable sheathing. Most of the absorption materials used today, also called superabsorbers, which are able to absorb large amounts of liquids (water, urine) in a short time, are primarily weakly cross-linked polyacrylates and are therefore not based on renewable raw materials and are comparatively inadequate or not biodegradable at all.

In order to build superabsorbents from renewable raw materials, as described in DE-PS 2612846, acrylic acid on polysaccharides, such as e.g. on cornstarch, grafted. However, only small amounts of polysaccharides (up to a maximum of 25%) can be used, since otherwise drastic deteriorations in the absorption properties are obtained.

Likewise, by incorporating polysaccharides into the polymerization gel of polyacrylates, as described in DE-OSs 40 29 591, 40 29 592 and 40 29 593, the polyacrylates can only be used up to max. 25% can be replaced without a significant deterioration in the absorption capacity and other properties of the resulting superabsorbers, even if various auxiliary substances such as fibers and e.g. Aluminum crosslinkers are added. The polysaccharides are seen as building blocks for the absorbers in order to obtain biodegradable units.

DE-PS 3132976 describes the mixing of polyacrylic acid with polysaccharides in powder form and in solution, the shell of the absorber particles of the mixtures being crosslinked with aluminum crosslinking agents such as Al (OH) ₂ OOCCH ₃ * 1/3 H ₃ B0 ₃ . Accordingly, no superabsorbers can be produced with this method, which consist of over 60% of renewable raw materials. In the processes described so far according to the current state of the art, the polysaccharides have no decisive contribution as an absorption component.

Numerous publications, such as DE-OS 2634539, describe the production of carboxymethyl cellulose absorbers, that is to say materials which are in principle biodegradable, by crosslinking the carboxymethyl cellulose with various crosslinking agents in the aqueous system. However, these absorbers show strong gel blocking.

US Pat. No. 4,959,341 describes the production of an absorber based on carboxymethyl cellulose, which consists of a mixture of carboxymethyl cellulose, cellulose fibers, a hydrophobic component and Al (OH) ₂ OOCCH ₃ * 1/3 H ₃ B0 ₃ as crosslinking agent exists, the aluminum crosslinking agent causing crosslinking of the carboxymethyl cellulose during the liquid absorption.

These absorbers have good absorption properties, but show block phenomena. In addition, these absorbers are easily separated by mechanical loads, such as screening or conveying, so that they are no longer present as a homogeneous product, which greatly limits their possible uses.

EP-PS 0 201 895 also describes the production of an absorber based on carboxymethyl cellulose. However, the manufacture of these absorbers is carried out in an aqueous solution in which the carboxymethyl cellulose is only present in a low concentration

REPLACEMENT LEAF is present. Furthermore, larger amounts of organic solvents such as acetone, methanol, etc. are required in the production. The production of these carboxymethyl cellulose absorbers also requires a great deal of time. The absorbers themselves show block phenomena and a low gel strength.

While the development of the superabsorbers initially focused solely on the very high swelling capacity when in contact with liquid, also called free swelling capacity, it was later shown that it is not only the amount of liquid absorbed that is important, but also the gel strength . Absorbance or swelling capacity or free swelling capacity, on the one hand, and gel strength in the case of a crosslinked polymer, on the other hand, are opposing properties, as is already known from US Pat. No. 3,247,171 (DOW / WALKER), and also from US Pat. Re 32 , 649. This means that polymers with a particularly high absorption capacity have only a low strength of the swollen gel, with the result that the gel is deformable under an applied pressure (for example body pressure) and prevents further fluid distribution and absorption . According to US Pat. No. Re 32,649, a balanced relationship between absorption capacity (gel volume) and gel strength should therefore be striven for, so that when such superabsorbers are used in a diaper construction, fluid absorption, fluid transport, dryness of the diaper and the skin are ensured. It is important not only that the polymer can retain liquid under the subsequent action of pressure after the polymer has been able to swell freely, but also that liquids can also be held against to absorb a pressure which is exerted simultaneously, ie during liquid absorption, as happens under practical conditions when a baby or a person sits or lies on a sanitary article or when shear forces develop, for example due to leg movement. The specific absorption property is referred to in EP-A-0 339 461 on pages 5 to 7 as absorption under pressure ("absorption under load" = "AUL").

The object of the present invention was to provide and produce a polymer composition, in particular an absorber, which does not have the deficiencies described above and which has the following properties: a) The absorber should consist predominantly of components of native origin and thus basically also be biodegradable. b) The absorbers should have a high mechanical strength, they may become sieved or e.g. do not separate them into their individual components when conveying screws. c) The absorbers should have a comparatively high absorption speed and capacity for water and aqueous solutions. d) The content of residual monomers should be significantly lower than in conventional absorbers based on polyacrylates.

e) The absorbers should have a very high gel stability when swollen; the absorber grains should be separated and be present in individual particles. f) You must not be prone to gel blocking. g) The absorbers should have a high absorption rate and absorption capacity under pressure for water and aqueous solutions. Another object is to provide an active ingredient composition, its production and use.

According to the invention, the first object is achieved by a polymer composition and a production process for a polymer composition, in particular an absorbent, which essentially consists of four components:

- A component A, which is based on renewable special raw materials,

component B, which consists of a special water-soluble polymer,

- a matrix material,

- an ionic or covalent crosslinker,

- and optionally an antiblocking agent.

The present invention relates to a polymer composition, in particular absorbent material composition, consisting essentially of

70-99.99% by weight of a component A based on water-soluble and / or water-swellable polymers based on polysaccharides, and their derivatives, which may have been modified by crosslinking and

0.01-30% by weight of a component B, based on water-swellable synthetic polymers and / or copolymers based on (meth) acrylic acid, (meth) acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyrrolidone, vinyl pyridine, Maleic acid (anhydride), itaconic acid (anhydride), fumaric acid, vinyl sulfonic acid and / or 2-acrylamido-2-methylpropanesulfonic acid as well as the amides, N-alkyl derivatives, the N, N'-dialkyl derivatives, hydroxyl group-containing esters and amino group-containing esters of these polymerizable acids, where

0 - 98% of the acid groups of these acids are neutralized, and these polymers and / or copolymers are crosslinked by a least bifunctional compound, as polymers

REPLACEMENT LEAF Components, as well as 0.1-30% by weight, based on these polymer components, of a matrix material with a melting point or softening point below 180 ° C to prevent segregation and gel blocking

0.001-10% by weight, based on these polymeric components, of an ionic or covalent crosslinking agent, and optionally 0-50% by weight, based on these polymeric components, of at least one antiblocking agent based on natural and / or synthetic fibers and / or materials with a large surface area, obtainable by bringing component B together with component A in an aqueous medium and then drying and grinding, adding the further components, mixing until homogeneous and carrying out a heat treatment and, if appropriate, adding the Crosslinker after this heat treatment fixes it with the matrix by means of a final heat treatment.

The present invention thus further relates to a process for producing a polymer composition, in particular an absorber material, consisting essentially of 70-99.99% by weight of a component A based on water-soluble and / or water-swellable polymers based on Polysaccharides and their derivatives, which may have been modified by crosslinking and 0.01-30% by weight of a component B, based on water-swellable synthetic polymers and / or copolymers based on (meth) acrylic acid, (meth) Acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyrrolidone, vinyl pyridine, maleic acid (anhydride), itaconic acid (anhydride), fumaric acid, vinyl sulfonic acid and / or 2-acrylamido-2-methylpropanesulfonic acid and the amides, N-alkyl derivatives, the N, N ^λ dialkyl derivatives, hydroxyl group-containing esters and amino group-containing esters of these polymerizable acids, with 0 - 98% of the acid groups of these acids being neutralized , and wherein these polymers and / or copolymers crosslinked by an at least bifunctional compound are, as polymeric components, and 0.1-30% by weight, based on these polymeric components, of a matrix material with a melting point or softening point below 180 ° C. to prevent segregation and gel blocking, 0.001-10% by weight .-%, based on these polymeric components, of an ionic or covalent crosslinking agent, and optionally 0 - 50% by weight, based on these polymeric components, of at least one antiblocking agent based on natural and / or synthetic fibers and / or materials with a large surface area, characterized in that this is obtained by bringing component B together with component A in an aqueous medium and then drying and grinding, adding the other components, mixing until homogeneous and heat treatment is carried out and, if necessary, the crosslinker is added after this heat treatment and fixed with the matrix by a final heat treatment.

It was surprisingly found that a slight addition of component B to component A in the production results in a significant improvement in the absorption properties. Since only small additions of component B are necessary, the residual monomer content is z. B. acrylic acid of such an absorber is significantly lower than that of polyacrylate-based absorbers.

The incorporation of component B into component A is achieved, for example, by swelling them together in water or in an aqueous solution and subsequent drying. Surprisingly, this method leads to a significant increase in the AUL value; moreover, surprisingly, the proportion of component B can be significantly reduced without impairing the absorption properties of the product.

It was also surprisingly found that by adding a solid which acts as a matrix for the absorber system in combination with the polymer absorbent, a mixture of components A and B, and an ionic crosslinker, an absorbent can be produced which has a high absorption rate and capacity for water and aqueous solutions and an improved mechanical strength with regard to the separation of the individual dry particles. Furthermore, the gels of this absorber system are present separately in individual particles.

In addition, surprisingly, in addition to the properties mentioned above, these absorbers have a gel strength which is significantly higher than that of absorbers which are based on polyacrylic acid.

Suitable as component A are water-soluble and water-swellable polymers based on polysaccharides and their derivatives, such as guar, carboxymethyl guar, xanthan, alginates, gum arabic, hydroxyethyl or hydroxypropyl cellulose, carboxymethyl cellulose and other cellulose derivatives, starch and starch derivatives such as carboxymethyl starch and mixtures thereof the individual polysaccharides. The preferred polymers are guar and the anionic derivatives of starch, guar and cellulose, carboxymethyl cellulose being a particularly preferred material.

The listed polymers of component A can be modified by crosslinking in order to reduce their water solubility and to achieve better swelling properties. The crosslinking can take place both in the entire polymer or else only on the surface of the individual polymer particles.

REPLACEMENT LEAF The polymers can be reacted with ionic crosslinking agents such as calcium, aluminum, zirconium, iron (III) and titanium compounds. Likewise, the reaction with polyfunctional carboxylic acids such as citric acid, mucic acid, tartaric acid, malic acid, malonic acid, succinic acid, glutaric acid, adipic acid, with alcohols such as polyethylene glycols, glycerol, pentaerythritol, propanediols, sucrose, with carbonic acid esters such as ethylene and propylene carbonate Amines such as polyoxypropylene amines, with epoxy compounds such as ethylene glycol diglydcidyl ether, glycol di- or triglycidyl ether and epichlorohydrin, with acid anhydrides such as succinic anhydride and maleic anhydride, with aldehydes and multifunctional (activated) olefido and amide-acrylamides such as bis (acrylate) as possible . Derivatives of the compound classes mentioned are of course also possible, as are heterofunctional compounds with various functional groups of the compound classes mentioned above.

As component B, water-swellable synthetic polymers or copolymers are primarily based on (meth) acrylic acid and also on the basis of (meth) acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyrrolidone, vinyl pyridine, maleic acid, maleic anhydride, Itaconic acid, itaconic anhydride, fumaric acid, vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and also the amides, their N and N, N'-dialkyl derivatives, hydroxyl-containing esters and aminogroup-containing esters of the polymerizable acids are suitable. Crosslinked, partially neutralized polyacrylates are preferred. Up to 98%, preferably 50-80%, of the acid groups can be neutralized.

The polymers can be crosslinked by an at least bifunctional crosslinker.

These above polymers are prepared by known processes (DE-PS 27 06 135, DE-OS 40 15 085). A particularly preferred material as component B are polyacrylates, for example the FAVOR ^R types manufactured by Chemische Fabrik Stockhausen GmbH.

Components A and B can be chemical, i.e. via ester linkages or by one of the crosslinkers mentioned or physically, i.e. in the sense of an "Interpenetrating Network" (IPN).

Suitable as a matrix are organic solids that melt or soften below 180 ° C and preferably have a soft consistency at room temperature, e.g. Triglycerine monostearate. Highly viscous liquids such as Castor oil suitable.

Polycaprolactones, such as TONE 0230 and 0240 from Union Carbide, which can also be modified, such as e.g. by reaction with maleic anhydride.

The matrix presumably gives the absorber system greater mechanical strength through chemical and / or physical interactions, as a result of which the individual components are separated by transport processes, such as by means of a Screw conveyor, or is greatly reduced by screening processes. As a result, an absorption medium can be produced which not only has high absorption values, but is also present in its area of use as a more homogeneous and thus more effective system after assembly or incorporation.

In addition, the embedding of the absorption material in the matrix surprisingly brings about a significant reduction or a complete elimination of the gel blocking, thus ensuring a high absorption rate in the entire absorber. Furthermore, the crosslinker is firmly fixed to the surface of the individual absorber particles by the matrix. The granulation of superabsorbent fines by agglomeration aids is described in the examples of DE-PS 37 41 157 and DE-PS 39 17 646. The products thus produced have a high absorption rate for water and aqueous solutions. However, these products consist only of polyacrylates and are consequently comparatively inadequate or not biodegradable at all. The agglomeration agents only serve to granulate a product and never as a matrix material.

The anti-blocking agents also reduce gel blocking; they therefore effect a faster and better absorption of liquid and ensure that the gels separate, i.e. exist in individual particles.

Suitable anti-blocking agents are known (see. DE-PS 31 41 098 and DE-PS 33 13 344) fiber materials and other materials with a large surface area.

The fibers can be natural or synthetic fibers, e.g. Wool, cotton, silk and cellulose fibers, or polyamide, polyester, polyacrylonitrile, polyurethane fibers, fibers of olefins and their substitution products as well as polyvinyl alcohol and their derivatives. Examples for anor

REPLACEMENT LEAF ganic materials are bentonites, zeolites, aerosils and activated carbons.

Suitable crosslinking agents are compounds which convert the polymers described above into a state in which the water solubility is reduced, the absorbency is improved and the blocking phenomena are reduced.

Metal compounds which can interact with the functional groups of the polymers are suitable as ionic crosslinkers. Magnesium, calcium, aluminum, zirconium, iron, titanium and zinc compounds which have very good water solubility, such as the salts of carboxylic acids and inorganic acids, are particularly preferred.

Preferred carboxylic acids are acetic acid, lactic acid, salicylic acid, propionic acid, benzoic acid, fatty acids, malonic acid, succinic acid, glutaric acid, adipic acid, citric acid, tartaric acid, malic acid and mucic acid. Preferred inorganic anions are chlorides, bromides, hydrogen sulfates, sulfates, phosphates, borates, nitrates, hydrogen carbonates and carbonates.

Organic compounds which contain polyvalent metals, such as acetylacetonates and alcohols, such as, for example, Fe (acac) ₃ , Zr (acac) ₄ , Ti (OBu) ₄ and Zr (o-prop) _{4, are also} suitable.

The water-soluble crosslinking agent brings about crosslinking of components A and B, both with one another and between one another, particularly on the surface, as a result of which, as in DE-PS 31 32 976, DE-PS 26 09 144 and US Pat. No. 4 959 341, the absorption properties are improved.

Polyfunctional carboxylic acids, alcohols, amines, epoxy compounds, carboxylic anhydrides and aldehydes and their derivatives are suitable as covalent crosslinking agents. Examples are Ci tronic acid, mucic acid, tartaric acid, malic acid, malonic acid, succinic acid, glutaric acid, adipic acid, polyethylene glycols, glycerol, propanediols, polyoxypropylene amines, epichlorohydrin, ethylene glycol diglycidyl ether, glycol diglycidyl ether, succinic acid carbonate and ethylene carbonate anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride, maleic acid anhydride,

Natural derivatives of the compound classes mentioned are also suitable, as are heterofunctional compounds with different functional groups of the compound classes mentioned above.

The proportion of component A in the ratio of component A to component B is 70 to 99.99% by weight, preferably 75 to 95% by weight. The proportion of component B is 0.01 to 30% by weight, preferably 5-25% by weight.

The addition, even in small amounts, of component B brings about a strong improvement in the absorption properties, especially in the absorbency. This enables a surprisingly significant improvement in the absorption properties compared to pure carboxymethyl cellulose material (CMC material). The necessary proportion of component B is significantly reduced by processing components A and B, for example in the swollen state and subsequent drying.

The amount of anti-blocking agent is preferably between 0.5 and 50% by weight, particularly preferably 5 to 15% by weight, based on components A and B.

The amount of crosslinker in the absorber is 0.001-10% by weight, preferably 3-7% by weight, based on components A and B.

The addition of matrix material, based on components A and B, should be between 0.1-30% by weight, preferably between 2.5 and 7.5% by weight.

The matrix material prevents the absorption material from falling apart, as is the case with pure physical mixtures such as e.g. US-A-4 952 550 is observed and additionally prevents gel blocking.

The preferred production of the absorption material is described below.

Step 1) Component A and component B are mixed physically in dry form at room temperature. Then they are allowed to swell with stirring in water or in an aqueous solution together. After 15 to 360 minutes, the material obtained is dried at 40 ° C. to 180 ° C. in a drying cabinet. The product obtained is then ground.

Step 2) The material obtained is mixed with the anti-blocking agent and the matrix component until a homogeneous mixture is obtained. The components are mixed in suitable mixers such as screw mixers, fluidized bed mixers, disk mixers or belt mixers.

The heat treatment takes place at 25 ° C to 180 ° C, preferably at 100 ° C - 120 ° C. The heating time is 5 to 60 minutes, preferably 20 to 40 minutes. Ordinary dryers or heating ovens (e.g. disc dryers, belt dryers, fluidized bed dryers or infrared dryers) are used for the heat treatment of the product.

Step 3) The ionic crosslinking agent, preferably aluminum dihydroxyacetate, stabilized with boric acid, is then mixed vigorously with the material obtained at room temperature until a homogeneous mixture is obtained. To fix the crosslinker through the matrix, the mixture is heated again to 25 ° C. to 180 ° C., preferably to 50 ° C. to 80 ° C., for 5 to 60 minutes in order to melt the matrix material.

REPLACEMENT LEAF If necessary, instead of the processing described in stage 1, component A can be swelled in component B (for example swollen with water) or component B in swollen component A or (for example swollen with water) the component A (for example swollen with water) is incorporated into the component B (for example swollen with water), optionally with the addition of water or an aqueous solution.

After grinding (stage 1), the product can be sieved, preferably to a particle size of 90-630 μm.

The matrix components are preferably incorporated at room temperature, but the matrix component can also be used as a melt. The mixture in stage 2 can be mixed with a preferably water / isopropanol mixture before the thermal modification in order to have a solubilizer. Instead of the water / isopropanol mixture, water and other mixtures of water with water-soluble organic solvents can also be used. EP-PS 0 083 022 describes the crosslinking of an absorber, which consists of polyacrylic acid, with crosslinking agents which contain at least two functional groups and are able to react with the carboxyl groups of the polyacrylate. The reaction takes place on the surface of the absorber particles. DE-PS 33 14 019 and DE-PS 35 23 617 also describe the surface crosslinking of polyacrylates with the aid of crosslinking agents which have at least two functional groups. In contrast to the absorbers according to the invention, only modifications of polyacrylates, but not of polysaccharides, are described in the shell in these patents, but this does not result in any absorbers which are sufficiently biodegradable. The ionic crosslinking agent can also be incorporated directly into the physical mixture of stage 2), whereupon at 25 ° C. to 180 ° C., preferably at 100 ° C. to 120 ° C., for 5 to 120 minutes, preferably for 20 to 60 Minutes is warmed.

The solvent step described above can be used with this

Procedures take place before or after the crosslinker is incorporated.

As an alternative and in addition to the ionic crosslinker, the covalent crosslinker can be added to the polymer mixture before or after the matrix addition.

The covalent crosslinker is dissolved in a preferably alcohol / water mixture, if appropriate, and added dropwise to the polymer mixture with rapid stirring. The amount of solvent is between 1 and 10% based on the polymer mixture. The mixture is then heated to 25 ° C to 180 ° C for 5 to 120 minutes. Water and mixtures of water with water-soluble organic solvents can be used as the solvent.

If necessary, the antiblocking agents as well as the equivalent crosslinking agent can already be added in stage 1).

The absorption material according to the invention shows good biodegradability compared to products based on a polyacrylic acid base, with a significantly improved absorption and absorbency for 0.9% cooking compared to previously known absorption materials on a native basis salt solution, even under pressure, with a surprisingly very high gel strength. Gel strength of some absorbers according to the invention and some absorbers known on the market

Product name Gel strength (10 Hz)

(N / m ² )

absorber according to the invention

Super absorber from example 1 10000

Superabsorbent from Example 3 2 10000

Super absorber from example 5 2 10000

Superabsorber from Example 7 2 10000

Super absorber from example 9 ti 10000

market-known absorbers

Product A 2450

Product B 4200

Product C 3500

Product D 2700

Product E 4950

Product F 3700

Product G 1575

Products A, B, C, D, F and G: cross-linked, partially neutralized polyacrylates Product E: cross-linked, partially neutralized polyacrylate starch graft polymer Furthermore, the mechanical strength (in terms of segregation into the individual components) is significantly improved compared to the previously described absorbers based on renewable raw materials.

The polymer composition according to the invention can be used in particular as an absorption material as fiber, film, powder or granulate to absorb water or aqueous liquids, such as urine and blood, and is therefore particularly suitable for use in diapers, tampons, surgical products, ^■ cable sheaths, Culture vessels, packaging materials for meat or fish and absorbent garments are suitable.

In addition, the material is suitable as a storage medium for the successive release of active substances, such as medicaments, pesticides (US 4,818,534; US 4,983,389; US 4,983,390; US 4,985,251) and fragrances, with the advantage that the storage medium is degradable.

This has the further advantage that the active ingredient is released completely.

The active substance-containing depot materials can be produced by absorption, preferably concentrated, aqueous or water-containing solutions in the largely dry absorber and, if necessary, drying them again.

The active ingredient can also be added directly or as a solution or dispersion in any preliminary stages of the manufacturing process of the absorber composition.

The active ingredient-containing depot materials are in powder form or as a dispersion in hydrophobic media, and the dispersion-stabilizing agents such as emulsifiers or stabilizers may contain, or used in a mixture with other substances such as polysaccharides.

For example, the addition of such bactericidal depot materials to cellulose, guar or starch products or their derivatives, such as carboxymethyl cellulose, prevents the degradation of these substances over a long period of time when stored and used in aqueous media, and thereby by the depot effect Larger amounts of free active ingredient in the solution can be avoided.

Test methods:

Tea Bag Test (TBT)

A tea bag test was carried out to determine the absorbency. An aqueous 0.9% NaCl solution was used as the test solution.

0.2 g of a test substance (sieved between 90 and 630 μm), which was weighed into a tea bag, was allowed to swell in the test solution for 10 or 30 minutes. After five minutes of dripping (maximum value), a centrifuge, e.g. in a commercial spin dryer, spun at 1400 rpm. The liquid intake was determined gravimetrically and converted to 1 g of substance. (Retention value).

Absorption under load (AUL)

In order to determine the liquid absorption capacity under pressure, the absorption under load was determined as described in EP-A 0 339 461.

0.16 g of test substance (sieved between 300 and 600 μm) was allowed to swell in 0.9% NaCl solution by capillary action for 60 minutes under a pressure of 1.55 kN / m ² (99.8 g / in ² ) .

SPARE BLADE " The liquid intake was determined gravimetrically and converted to 1 g of substance.

Gel strength (G ')

In order to determine the gel strength G 'of the swollen absorbers, the procedure described in EP-A 0 339 461 was followed. Device: Controlled Stress Rheometer CS 100, Carri-Med Ltd. Dorking / UK.

Measuring conditions: plate-plate system, diameter 60 mm, plate spacing 2 mm, temperature 20 ° C, torque 1000 - 4000 μNm, amplitude 1.5 - 5 mrad, frequency 10.0 Hz, 28 ml 0.9% NaCl / g absorber. The information is given in N / m.

Flow test (FT)

The flow test was used to determine how quickly the products absorbed the test liquid, whether they showed block phenomena, were completely swollen and were wetted everywhere. It was also examined whether the gels were solid, sticky or loose and separated.

To carry out the flow test, approx. 100 mg of substance were placed on a paper towel soaked in water and it was followed how the water was absorbed by the products. The absorption behavior was evaluated according to the following grading scale.

A pulls in quickly B pulls in very quickly C pulls through from start to finish D Gel is separated after water absorption before gel blocking The invention is explained in more detail below by means of manufacturing and application examples.

Intermediate products

The mixtures listed below are stirred in at room temperature (15 to 20 ° C.) in 360 ml of water and left to stand for three hours. The gels obtained are then dried in a forced-air drying cabinet at 100 ° C. for two hours, then ground and sieved to a particle size of 90-630 μm.

Intermediate 1

38 g of CMC Walocel 40000 (sodium carboxymethyl cellulose, Wolff Walsrode), 2 g of a polyacrylate superabsorber (produced according to DE-OS 40 15 085, Example 4, hereinafter referred to as "SAB A")

Intermediate 2

38 g CMC, (Walocel 30000), 2 g "SAB A"

Intermediate 3

36 g CMC, (Walocel 30000), 4 g "SAB A"

Intermediate 4

32 g CMC, (Walocel 30000), 8 g "SAB A"

Intermediate 5

32 g CMC, (Walocel 30000), 8 g "SAB A", 4 g cellulose fiber (PWC 500, Rettenmaier)

Intermediate 6

28.5 g CMC, (Walocel 30000), 9.5 g guar flour (type 104, Roeper), 2 g "SAB A"

Intermediate 7

40 g CMC, (Walocel 40000) without additives

Examples

example 1

5 g of the preliminary product 1 are mixed with 0.25 g (cellulose, diameter: 17 μm, length: 30 μm) of BE 600/30 fiber (from Retten¬maier) and 0.25 g of acid-terminated TONE 230 (a reaction) product from TONE 230 polyol based on caprolactone, molecular weight 1250 g. mol ^-1 ) from Union Carbide and maleic anhydride) was mixed vigorously and then heated to 120 ° C. in an oven for 30 minutes. Then 0.25 g of Al (OH) ₂ OOCCH ₃ * l / 3 H ₃ B0 _{3 is} added and the mixture is heated in an oven at 50 ° C. for one hour. TBT (max./ret.) = 48 g / g / 26 g / g; AUL = 18.0 g / g; FT: BCD

Example 2

5 g of the preliminary product 2 are mixed vigorously with 0.25 g Aerosil R 972 (pyrogenic silica, particle diameter: 16 nm Degussa AG), 0.25 g acid-terminated TONE 230, 0.5 ml water and 1 ml i-propanol then heated to 120 ° C in the oven for 30 minutes. Then with 0.25 g

ERS ^A TZBLATT AI (OH) ₂ OOCCH ₃ * l / 3 H ₃ B0 ₃ added and on for one hour

Heated in the oven at 50 ° C.

TBT (max./ret.) = 51 g / g / 28 g / g; AUL = 19.6 g / g; FT: B C D

Example 3

The procedure is as in Example 2, but instead of intermediate 2, intermediate 3 is used; in addition, the Aerosil A 200 (pyrogenic silica, particle diameter: 12 nm Degussa AG) is used instead of the Aerosil R 972. TBT (max./ret.) = 45 g / g / 27 g / g; AUL = 17.0 g / g; FT: B C D

Example 4

The procedure is as in Example 2, but pure TONE 230 is used instead of the acid-terminated TONE 230; moreover, vigorously mixed with twice the amount of water and twice the amount of i-propanol. TBT (max./ret.) = 52 g / g / 29 g / g; AUL = 19.0 g / g; FT: B C D

Example 5

The procedure is as in Example 2, but the preliminary product 5 is used. TBT (max./ret.) = 47 g / g / 27 g / g; AUL = 18.3 g / g; FT: B C D

Example 6

The procedure is as in Example 3, but only half the amount of acid-terminated TONE 230 is used, and in addition the Aerosil A 200 is replaced by the same amount of BE 600/30 fiber. TBT (max./ret.) = 52 g / g / 29 g / g; AUL = 18.7 g / g; FT: BCD

Example 7

The procedure is as in Example 2, but 0.25 g of BE 600/30 fiber are additionally incorporated (before the first heating). TBT (max./ret.) = 49 g / g / 28 g / g; AUL = 18.9 g / g; FT: B C D

Example 8

The procedure is as in Example 2, but the preliminary product 6 is used. TBT (max./ret.) = 38 g / g / 22 g / g; AUL = 16.5 g / g; FT: A C D

Example 9

The procedure is as in Example 2, but the preliminary product 5 is used. In addition, the amount of aluminum crosslinker is reduced to 0.2 g. TBT (max./ret.) = 49 g / g / 28 g / g; AUL = 16.8 g / g; FT: A C D

Example 10

100 g of the product obtained in Example 1 are mixed with 100 ml of a 0.125% aqueous solution of 3,7-bis (dimethyl-a ino) phenothiazinium chloride and then dried at 60 ° C. in a forced-air drying cabinet for 2 h. 200 mg of the product thus obtained are placed in a tea bag. This is suspended in a beaker with 50 ml of 0.2% saline. The tea bag is removed after one hour. The color of the saline solution is assessed, then the process is repeated with new NaCl solution.

Even after the 5th cycle, the blue color of the saline solution indicates the release of the active ingredient from the polymer composition which acts as the storage medium.

Example 11

In the preparation of intermediate 1, an additional 0.05 g of 3,7-bis (dimethylamino) phenothiazinium chloride is added to the powder mixture and further processed as described. An absorber is produced from this preliminary product in accordance with Example 1. The absorber thus represented is examined as described in Example 10. The results obtained are in agreement with those obtained in Example 10.

Comparative Examples

Comparative Example 1

The procedure is as in Example 2, but the preliminary product 7 is used and the amount of acid-terminated TONE 230 is halved. TBT (max./ret.) = 36 g / g / 27 g / g; AUL = 8.0 g / g; FT: E

REPLACEMENT LEAF Comparative Example 2

20 g of CMC 30000 are mixed with 8 g of isopropanol, 200 g of water, 0.4 g of Al (OH) ₂ OOCCH ₃ * l / 3 H ₃ B0 ₃ and 0.8 g of acetic acid for 4 hours

Kept at 50 ° C. Then it is dried at 80 ° C.

TBT (max./ret.) = 16 g / g / 11 g / g; AUL = 8.9 g / g _; FT: E

Comparative Examples 3, 4

The production of the products from Examples 3 and 5 was repeated without the addition of a matrix material. The products obtained were inhomogeneous, could be separated by sieving and blocked. Regarding the TBT and the AUL test, no reproducible values could be obtained due to the inhomogeneity of the products (segregation during sieving).

Comparative Example 5

60 g of CMC 40000 are mixed vigorously with 1.5 g of ethylene carbonate, 1.5 ml of water and 1.5 ml of isopropanol; then heated to 120 ° C in the oven for 60 min. 8 g of this product are mixed with 2 g Favor ^R 953 (cross-linked, partially neutralized polyacrylate from Stockhausen GmbH), 0.5 g TONE 230, 0.5 g fiber BE 600/30 and with 0.5 g AI (OH) ₂ OOCCH ₃ * 1/3 H ₃ B0 ₃ vigorously mixed using 2 ml isopropanol and 1 ml water and heated to 120 ° C in the oven for 60 min. TBT (max./ret.) = 46 g / g / 29 g / g; AUL = 14.4 g / g; FT: BCD

Comparative Example 6

8 g CMC 40000 are mixed vigorously with 2 g "SAB A", 0.5 g fiber BE 600/30, 0.5 g acid-terminated TONE 230, 0.1 g Aerosil R 972, 2 ml i-propanol and 1 ml water then heated to 120 ° C in the oven for 30 minutes. The pro thus obtained 0.6 g of Al (OH) ₂ OOCCH ₃ * 1/3 H ₃ B0 _{3 is} added to the product and the mixture is then heated to 50 ° C. in an oven for one hour. TBT (max./ret.) = 51 g / g / 36 g / g; AUL = 11.0 g / g _; FT: BCD

Claims

PATENT CLAIMS

1. Polymer composition, in particular absorbent material composition, consisting essentially of 70-99.99% by weight of a component A based on water-soluble and / or water-swellable polymers based on polysaccharides and their derivatives, which may have been modified by crosslinking and 0.01-30% by weight of a component B, based on water-swellable synthetic polymers and / or copolymers based on (meth) acrylic acid, (meth) acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyrrolidone, vinyl pyridine , Maleic acid (anhydride), itaconic acid (anhydride), fumaric acid, vinylsulfonic acid and / or 2-acrylamido-2-methylpropanesulfonic acid as well as the amides, the N-alkyl derivatives, the N, N '-dialkyl derivatives, hydroxyl-containing esters and ami- nogroup-containing esters of these polymerizable acids, where 0 - 98% of the acid groups of this acid are neutralized, and where these polymers and / or copolymers are at least bifunk tional compound are crosslinked, as polymeric components, and 0.1-30% by weight, based on these polymeric components, of a matrix material with a melting point or softening point below 180 ° C. to prevent segregation and gel blocking, 0.001 10% by weight, based on these two polymeric components, of an ionic and / or covalent crosslinking agent, and 0-50% by weight, based on these polymeric components, of at least one antiblocking agent based on natural and / or or synthetic fibers and / or high surface area materials

REPLACEMENT LEAF by bringing component B together with component A in an aqueous medium, then drying and grinding, mixing in the other components, mixing until homogeneous and carrying out a heat treatment and, if necessary, adding the crosslinker after this heat treatment and fixing it by the matrix by means of a final heat treatment .

2. Active ingredient-containing composition, consisting essentially of a composition according to claim 1 and at least one active ingredient, for example a medicament, a pesticide, a bactericide and / or a fragrance, which is released with a delay.

3. Composition according to claim 1 or 2, consisting essentially of 75-95% by weight of component A, 5-25% by weight of component B as polymeric components and 2.5-7.5% by weight, based on these components, at least one matrix material, 3-7% by weight, based on these components, at least one ionic and / or covalent crosslinking agent and 0.5-50% by weight, preferably 5- 15% by weight, based on these components of at least one antiblocking agent.

4. Composition according to claims 1, 2 or 3, characterized in that component A is a water-soluble and / or water-swellable polymer based on polysaccharides and their derivatives, in particular guar, starch and cellulose derivatives.

5. Composition according to claim 4, characterized in that component A is an anionic derivative of cellulose, in particular of carboxymethyl cellulose.

6. Composition according to claims 1, 2 or 3, characterized in that the matrix material is a substance which is highly viscous at room temperature or has a waxy, soft consistency.

7. Composition according to claim 6, characterized in that the matrix material is selected from triglycerol monostearate, castor oil and polycaprolactones, which are optionally modified by a reaction with maleic anhydride.

8. Composition according to claims 1, 2 or 3, characterized in that the ionic crosslinkers are selected from metal compounds, preferably magnesium, calcium, aluminum, zirconium, iron, titanium and zinc compounds in the form of them Salts with organic and inorganic acids.

9. Composition according to claims 1, 2 or 3, characterized in that the covalent crosslinking agents are selected from polyfunctional carboxylic acids, alcohols, amines, epoxy compounds, carboxylic acid anhydrides and / or aldehydes and their derivatives and heterofunctional compounds with various functional ones Groups of the named connection classes.

10. Process for the preparation of a polymer composition, in particular an absorber material, consisting essentially of 70-99.99% by weight of a component A based on water-soluble and / or water-swellable polymers based on polysaccharides and their derivatives, which, if appropriate have been modified by crosslinking and 0.01-30% by weight of a component B, based on water-swellable synthetic polymers and / or copolymers based on (meth) acrylic acid,

(Meth) acrylonitrile, (meth) acrylamide, vinyl acetate, vinyl pyrrolidone, vinyl pyridine, maleic acid (anhydride), itaconic acid

(anhydride), fumaric acid, vinyl sulfonic acid and / or 2-acrylamido-2-methylpropanesulfonic acid as well as the amides, the N-alkyl derivatives, the N, N ^X -dialkyl derivatives, hydroxyl group-containing esters and amino group-containing esters of this polymerizable acid, where 0 - 98% of the acid groups of this acid are neutralized, and these polymers and / or copolymers are crosslinked by an at least bifunctional compound, as polymeric components, and 0.1-30% by weight, based on these polymeric components, of a matrix material with a melting point or softening point below 180 ° C. to prevent segregation and gel blocking, 0.001-10% by weight, based on these two polymeric components, of an ionic and / or covalent crosslinking agent, and 0-50% by weight. -%, based on these polymeric components, at least one antiblocking agent based on natural and / or synthetic fibers and / or materials with a large surface area, thereby ge indicates that this (s) is obtained by bringing component B together with component A in an aqueous medium, then drying and grinding, adding the other components, mixing until homogeneous and carrying out a heat treatment and, if appropriate, adding the crosslinking agent after this Heat treatment fixes this through the matrix by means of a final heat treatment.

REPLACEMENT LEAF

11. The method according to claim 10, characterized in that a polymer composition, in particular an Absorberma¬ material, consisting essentially of 75-95 wt .-% component A, 5-25 wt .-% component B, as polymeric components and 2.5-7.5% by weight, based on these components, of at least one matrix material, 3-7% by weight, based on these components, of at least one ionic and / or covalent crosslinker and 0.5- 50% by weight, preferably 5-15% by weight, based on these components, uses at least one antiblocking agent.

12. The method according to claims 10 or 11, characterized gekenn¬ characterized in that component A uses a water-soluble and / or water-swellable polymer based on polysaccharides and their derivatives, in particular guar, starch and cellulose derivatives.

13. The method according to claim 12, characterized in that an anionic derivative of cellulose, in particular of carboxymethyl cellulose, is used as component A.

14. The method according to claims 10 or 11, characterized gekenn¬ characterized in that the matrix material used is a substance which is highly viscous at room temperature or has a wax-like soft consistency.

15. The method according to claim 14, characterized in that the matrix material is selected from triglycerol monostearate, castor oil and polycaprolactones, which are optionally modified by reaction with maleic anhydride.

16. The method according to claims 10 or 11, characterized gekenn¬ characterized in that the ionic crosslinkers are selected from metal compounds, preferably magnesium, calcium, aluminum minium, zirconium, iron, titanium and zinc compounds in the form of their salts with organic and inorganic acids.

17. The method according to claims 10 or 11, characterized gekenn¬ characterized in that the covalent crosslinkers are selected from polyfunctional carboxylic acids, alcohols, amines, epoxy compounds, carboxylic acid anhydrides and / or aldehydes and their derivatives and heterofunctional compounds with various functional groups of the named connection classes.

18. The method according to claims 10 to 17, characterized gekenn¬ characterized in that component B is contacted in the manner with component A by mixing both components, bringing them together in an aqueous medium, then in a water-containing solution or dispersion swells, dries and grinds.

19. The method according to claim 18, characterized in that either the two polymeric components are mixed in dry form or a dry polymeric component is mixed with the other polymeric component in a form already swollen by a water-containing solution or dispersion.

20. The method according to claims 10 to 17, characterized gekenn¬ characterized in that component B is contacted with component A in such a way by swelling the component B swollen by a water-containing solution or dispersion with a water-containing solution or dispersion swollen component A, optionally with the addition of a water-containing solution or dispersion, dries and grinds the components.

21. The method according to any one of the preceding claims, characterized in that the bringing together of the Polymerkomponen¬ th and the mixing of the other components at temperatures from 0 ° C to 100 ° C, preferably at room temperature.

22. The method according to claims 18 to 21, characterized gekenn¬ characterized in that the drying is carried out at 40 ° C to 180 ° C and the ground product is sieved to a grain size of 90 to 630 microns.

23. The method according to any one of the preceding claims, characterized by that the heat treatment at 25 ° C to 180 ° C, preferably 100 ° C to 120 ° C and the final heat treatment at 25 ° C to 180 ° C, preferably 50 ° C to 80 ° C.

24. The method according to any one of the preceding claims, characterized in that, after the grinding, the further components are mixed in the presence of a water-containing solution or dispersion, preferably water or a mixture of water and a water-containing organic solvent.

25. The method according to any one of the preceding claims, characterized in that the crosslinking agent is dissolved or dispersed in a mixture of water and / or a water-containing organic solvent and the polymer components to be contacted or the further components before heating action leads.

REPLACEMENT LEAF

26. A process for the preparation of a depot material composition according to claims 10 to 25, characterized in that the active ingredient

- is either absorbed from aqueous or water-containing solutions of the composition according to claims 1 and 3 to 9 and optionally dried again ^' ,

- or as a solution or dispersion in any preliminary stages of the production process of said composition is added.

27. Use of the composition according to claims 1 and 3 to 9 or produced according to claims 10 to 25 as fiber, film, powder or granules for the absorption of water-entraining solutions or dispersions and (body) liquids, in chemical-technical Products such as in packaging materials, in culture vessels, for soil improvement and as cable sheathing or in hygiene articles such as tampons or diapers and animal hygiene articles.

28. Use of the composition according to claims 2 to 9 or produced according to claim 26, in powder form or as a dispersion in hydrophobic media, optionally in combination with dispersion stabilizers or in a mixture with other substances.

29. (Animal) hygiene article containing a composition according to claims 1 to 9 or produced according to claims 10 to 26.

30. Chemical-technical products containing a composition according to claims 1 to 9 or produced according to claims 10 to 26.