DE1504733A1 - Process for the production of fine-pored foils - Google Patents

Description

Process for the production of fine-pored foils.

The present invention relates to fine-pored films.

In a method according to the invention for producing fine-pored Foils or sheets made of a material referred to below as "material" the material is coated with a finely divided, water-soluble and pore-forming material, E.g., an inorganic salt, as well as a solvent mixed that the pore-forming Does not attack material significantly, but is able to form a gel with the material, by mixing a dough is formed which is made into strips, the Strip is heated to drive off the solvent, the pore forming material is removed by leaching in an aqueous bath and then dried, The invention is characterized in that in the initial Mixture from which the strip is formed, plus a water-insoluble, surface-active agent is introduced, which at the working conditions, working temperatures and working pressures does not experience any noteworthy chemical impairment.

The surfactant can increase the wettability of the material affect and make it either hydrophilic and wettable or hydrophobic and water-repellent do.

In addition or in addition, this substance can be used to modify the pore structure of the material and, for example, the water vapor permeability and / or Pore size leg. rivers.

If the surface-active substance is to influence the wettability, Of course, there must still be a sufficient amount of it in the finished material to be available.

According to one embodiment of the invention, a surface-active one is used Material chosen that makes the finished, fine-pored material hydrophilic, one such surfactant can therefore be referred to as a wetting agent.

It has hitherto been customary to use foils of this type without the addition of the desired Produce wetting agent and introduce the latter in a separate process step, however, this involves a considerable increase in the time required at the production and cost of the finished product result.

The invention can be applied to the production of hydrophilic fine-pored Use foils for a wide variety of purposes, e.g. on artificial leather, which turns out to be Lining suitable for shoes. For such purposes, the wetting agent must be used against the substances with which it comes into contact, be inert and insoluble and should in particular be able to make the material hydrophilic at pH values between about 6 and 9. A wetting agent suitable for shoe lining materials can be sulfonated alkali metal salts or sulfated derivatives of substituted, long-chain aliphatic dicarboxylic acids included, e.g. Bis-alkyl sulfonate dicarboxylic acids, especially the sodium salt the bis-alkyl sulfosuccinates.

Examples of wetting agents that are particularly useful for shoe leather linings are suitable under the trade name '1Manoxol "in the trade, e.g. Manoxol IB, MA, OT, (sodium dinonyl sulfosuccinate), N or TR.

The invention can also be applied to the manufacture of separating elements use for batteries or collectors. In this case, the wetting agent must then be related of the electrolyte used in the specific case must be inert.

In the case of acid-filled lead collectors, the wetting agent must, for example be inert to the acid and the material in an acidic environment, i.e. at pH values make under 3 hydrophilic.

For the latter purpose, a wetting agent can be used, contains the ethoxylated fatty acid amines, e.g. B. Substances under the trade names Catafor 02, Ethomeen 18/15, Ethomeen C / 12 or Ethomeen S / 15 are sold. the Substances sold under the name "Ethomee" are tertiary amines with a Fatty alkyl group (of fatty acids with 12 to 18 carbon atoms) and two on nitrogen bonded hydroxyethyl or polyoxyethylene groups.

In another embodiment of the invention, a surfactant is used Substance used that makes the finished fine-pored material hydrophobic and therefore called Impregnation agent can be designated. This form of the invention is suitable for the production of hydrophobic fine-pored films that are used for the can be used for a wide variety of purposes, e.g. for artificial leather, as upper leather is suitable, or for upholstery purposes.

Again, the surfactant must be inert and insoluble to the substance with which it comes into contact, while at the same time rendering the material hydrophobic or water-repellent. As Imprägnierungsmit tel for shoe upper materials, for example, substances can be used that contains a long-chain polymer of dialkyl or arylalkyl-siloxane units, eg. B. a silicone resin. A substance which is particularly suitable as an impregnating agent is commercially available under the trade name Silicone M 492 "and consists of one Solution containing about 50 solids content of silicone resin. The product sold under the name "Silicone R 205" is also suitable.

The surface-active substance is expediently mixed with the solvent, in which the surface-active substance can optionally also be soluble, see above that an even distribution throughout the dough is guaranteed.

According to a further embodiment of the present invention, the surfactant is also chosen so that it has the pore structure of the finished affects fine-pored material. The surface-active substance here can be the middle one Pore size and also the water vapor permeability of the finished fine-pored Affect materials.

Preferably the surfactant is chosen so that it a reduction in the mean pore size or an increase in water vapor permeability, but in particular both causes.

All three types of surfactants mentioned above have a certain influence on the pore structure of the finished fine-pored Materials.

To influence the pore structure, a surface-active Substance used are the alkali metal salts of sulfonated or sulfated derivatives substituted long-chain aliphatic dicarboxylic acids, ethoxylated Fatty acid amines or long-chain polymers composed of dialky- or arylalkyl-siloxane units contains.

For a desired change in the properties according to the intended use of the finished product can be any of the above Commercially available materials can be used as surfactants.

However, it has specifically been found that the manoxols, in particular Manoxol N and TR a noticeable increase in the water vapor permeability of the finished effect fine-pored material.

Silicone M 492 also increases the water vapor permeability considerably.

Silicones M 492 and Manoxol N and TR are therefore preferably used, if the finished product should have the highest possible water vapor permeability. On the one hand, this applies to shoe upper leather materials, rainwear and bandage materials to, which should also be water-repellent, and on the other hand for shoe lining materials, which should be hydrophilic.

The invention can be used in a wide variety of manufacturing processes can be used for sinporous foils. It is explained in the following with the aid of some exemplary embodiments explained in more detail. The compositions are in parts by weight in all examples specified.

Example 1.

The main features of the procedure in this example are known (British Patent specification 727,679) and can be carried out using the following starting materials are: polyvinyl chloride (material) 100 parts dibutyl phthalate (plasticizer) 75 Parts sodium chloride (pore-forming material) 700 parts methylcyclohexanone (solvent) 170 parts The starting materials listed above are thoroughly mixed and extracted the dough-like mixture is formed into a film by means of a press, which by means of a calender is processed further. The solvent is then evaporated removed and the then relatively stiff film is calendered again with it the particles of the pore-forming material the surrounding walls made of the film material break through and come into contact with each other. Then the pore-forming Salt leached with water and the slide is after drying in a drying oven wound up.

According to the invention, this known method is modified to the effect that that the initial mixture contains a small amount of a desired surfactant Substance is added. The surfactant can be used in an amount up to about five parts are added, a proportion between two and three parts is preferred.

The present embodiment is particularly suitable for producing waterproof surgical clothing and is used in this case as a surface-active agent, the silicone resin available under the trade name Silicone M 492 ". If the finished product is intended for other purposes, other of the above-mentioned surface-active substances can of course also be added.

Example 2.

In this example the invention is known to another Process (British patent specification 884,232) used in which with the following starting materials can be worked: polyvinyl chloride (material) 100 parts sodium chloride (pore-forming Material) 150 parts of olypropylene sebacate (plasticizer) 60 parts of solution naphtha (solvent for the plasticizer) 65 parts The procedure is similar to Example 1 with the exception that the polyvinyl chloride material as a solid discontinuous Phase is present which does not dissolve and which therefore also appears as a solid discontinuous Phase present sodium chloride cannot include. The third, liquid phase consists of the solvent for the plasticizer (but not for the Material). The raw materials are mixed cold and the resulting, smooth, creamy Mixture is applied as a thin film using a squeegee on a temporary or permanent basis Document distributed. The solvent is then driven off at a higher temperature and the temperature is then additionally increased to the extent that a Gelling of the PVC material occurs due to the plasticizer. In this gelation there is some swelling of the PVC particles, but not for entrapment of sodium chloride particles is sufficient since no further mixing is carried out. The sodium chloride is then leached out with water as in the first example the film is then dried.

When the invention is applied to this method, the initial mixture a surface-active substance in a proportion up to about five parts, preferably added in a proportion of about 2 to 3 parts.

This embodiment can be used to produce water-repellent Materials that can be used, for example, for surgical clothing or as cover materials suitable for upholstery purposes, then used as a surfactant Silicone M 492 is used.

However, the process can also be used to produce water-absorbent Materials serve, e.g. shoe lining materials, whereby then as surface-active Fabric Manoxol TR suitable is. Surfactants that are involved in Other uses of the end product are preferred are indicated above.

Example 3.

In this example, the procedure is similar to an older proposal in its own right (German patent application P 35 555 IVc / 39b). The starting materials are: polyurethane rubber (Estane 5740X1) (material) 100 parts sodium chloride (pore-forming material) 100 Parts of cyclohexanone (solvent) 400 parts In this process, the polyurethane rubber and its solvent and the finely divided, water-soluble pore-forming material mixed with the aid of mixing rollers, paint mills or the like. The dissolution of the polymer The material in the solvent can, if desired, be accelerated by heating. At least as much solvent is used as for complete dissolution of the material and inclusion of the pore-forming material in the solution is. The proportion of solvent can be increased beyond this minimum amount, around the final mixture, a consistency suitable for easy spreading to give, e.g. the consistency of an ordinary paint. The mix will then spread as a thin layer on a running belt, whose Thickness depends on the thickness prescribed for the final film and the im further course of the procedure takes into account the loss that occurs. The tape with The applied film is next passed through an oven in which a temperature of 100 0C prevails, so that the solvent evaporates and the dimensions of the film dwindle considerably. Because of the adhesion of the film to the tape, that is in practice occurring shrinkage is essentially limited to the thickness direction, while in No substantial shrinkage occurs in the direction of the length or width of the film. At the Shrinkage of the film breaks the enclosure of the pore-forming particles. That The pore-forming material is then mixed with water as in the other exemplary embodiments dissolved out and the film is then dried.

Applying the invention to this method becomes the initial Mixture with a surface-active agent suitable for the intended use of the end product Substance in an amount up to about five parts, preferably about two to three parts offset.

The method of this example can be used to make water repellant Materials, e.g. protective clothing such as rainwear or footwear are used, Silicone M 492 is then used as the surfactant. If that End product intended for a different use will be the other surfactants mentioned above are added.

Example 4.

The procedure in this example corresponds to a separate proposal with the same priority and is based on the following raw materials: Polyvinyl chloride (material) 100 parts ammonium sulfate (pore-forming material) 600 parts carbon black (color pigment) 2 parts wood flour (filler) 5 parts isophorone (solvent) 125 parts (white spirit) (solvent) 85 parts The pore-forming material, the particle size of which is within a relatively narrow, suitable range, is thoroughly mixed dry with the material and the other powdery materials. The solvent is then added to the powder mixture and the new mixture is mixed thoroughly to form a dough-like mass. The dough-like mass is then pressed out in the form of a strip which passes through a calender unit, ribs being formed on the strip. The strip is then passed through an oven to drive off the solvent. The temperature in this furnace is considerably higher than would be required for practically complete removal of the solvent in order to simultaneously break open the enclosures of the particles of the pore-forming material under the action of this elevated temperature. The pore-forming material is then dissolved out with water and the film strip is dried by evaporating the water.

When applying the invention to this process, the initial mix a suitable surfactant in an amount up to five parts, preferably two to three parts added. To ensure proper distribution of these very small Ensure amount of surfactant is in a correct amount appropriate proportion of the solvent previously dissolved before the solvent is introduced into the powder mixture.

In the manufacture of separating membranes for electric batteries fabrics like Catafor 02 are preferred. For other uses of the end product other surfactants can be used.

As mentioned above, the starting materials therefore include a surface-active one Substance, e.g. a wetting agent, which contains Catafor 02. When choosing the surface active Substances are carefully taken to ensure that they are used in the course of the procedure not affected by the temperatures and by the water with which the ammonium sulfate is removed cannot be dissolved. The surfactant So remains in the material during the whole process and therefore it is not necessary, the> wetting agent in an additional time-consuming Process step to be introduced into the finished film strip.

Surfactants used in the manufacture of partitions or - membranes for batteries and collectors must be used during of the procedure withstand heat and boiling water, and also under the action the acid with which the battery is filled can act as a wetting agent. A necessary condition for a wetting agent that can also be used in a strongly acidic solution, e.g. an acid used as a filling for a collector, is intended to be effective it appears that the molecule is cationic and has a molecular weight of at least has about 500.

Various materials can be used as surface-active substances, but preferred materials are ethoxylated fatty acid amines according to the general formula The substances commercially available under the trade names Catafor 02, Ethomeen 18/15, Ethomeen C / 12 and Ethomeen S / 15 are preferred.

At Ethomeen C / 12, R is essentially cH3 (cH2) 11, the starting material is an impure laurylamine CH »(CH2) 11NH2, which is obtained from coconut oil will. In Catafor 02, R is similar, but you can use a purer Use amine raw material. In both cases n = 2.

For a wetting agent that works in an aqueous alkaline solution should be, apparently a molecular weight of at least 500 is required, however, the molecule need not be cationic and the preferred substances are in even anionic in practice.

Examples of anionic surfactants which are suitable as wetting agents include alkali metal salts of sulfonated or sulfated derivatives of substituted long-chain aliphatic dicarboxylic acids, e.g. Bis-alkyl-sulfonated dicarboxylic acids, in particular the sodium salt of the bis-alkyl sulfosuccinates of the following general formula: R stands for an alkyl group.

Surface-active substances of this type are, for example, under the Sold under the trade name Manoxol.

In Manoxol IB, R = C4H9: in Manoxol MA, R = C6H13; In Manoxol OT is R = C8H17; in Manoxol N, R = C9H19 and in Manoxol CR, R = C1DH27.

For the alkyl groups, the range from Cg to C20 is preferred, including fall Manoxol N and TR.

The preferred wetting agents have a nonionic character and generally much higher molecular weights. With are best suited Substances that contain silicon atoms in the molecule, e.g. long-chain polymers from dialkyl or arylalkyl siloxane groups, in particular silicone resins.

Of the commercially available substances, Silicones M 492 and Silicones R 205 preferred.

It has already been mentioned that the surfactants Besides acting as a wetting agent or impregnating agent, the porosity of the affect porous plastic materials. By suitable choice of the surface-active Substance and the application of the porous plastic material can lead to this effect Advantage of the end product can be exploited.

Claims (19)

Claims. Process for producing a fine-pored film from a material in which the material with a finely divided, water-soluble pore-forming material, e.g., an inorganic salt, and a non-dissolving pore-forming material, a gel-forming solvent with the material to form a dough-like mixture mixed, expelled the solvent and the pore-forming material in one aqueous bath is dissolved and the film is dried, d u r c h ek e Note that the initial mixture from which the strip is formed a water-insoluble, surface-active substance is added, which affects the working conditions, Withstands working temperatures and pressures without significant chemical damage. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t that a surfactant is chosen that has the pore structure of the Finished fine-pored material affects. 3. The method according to claim 2, d a d u r c h g e k e n n z e i c h n e t that a surfactant is used that has the mean pore size of the finished fine-pored material is reduced. 4. The method according to claim 2 or 3, d a -d u r c h g e k e n n z E i n e t that a surfactant is used which increases the water vapor permeability of the finished fine-pored material increased 5. Method according to one of the preceding Claims, d u r c h e k e n n n z e i c h n e t, that as surface-active Substance a wetting agent is used, which makes the finished fine-pored material hydrophilic power. 6. The method according to claim 5, for example for the production of Artificial leather, which is suitable as a lining for shoes, d u r c h e k e n n z E i r e t that a wetting agent is used that the material at pH values Makes from about 6 to 9 hydrophilic. 7. The method according to claim 5 or 6, d a -d u r c h g e k e n n z E i c h n e t that the wetting agent is at least one alkali metal salt sulfonated or contains sulfated derivatives of substituted long-chain aliphatic dicarboxylic acids. 8. The method according to claim 7, d a d u r c h g e k e n n z e i c h n e t that the wetting agent contains sodium salts of the bis-alkyl sulfosuccinates. 9. The method according to claim 8, characterized in that at least one compound of the formula as a wetting agent is used, where R stands for alkyl groups with 9 to 20 carbon atoms, in particular C4H9, C6H13, C8H17, C9H19. 10. The method according to any one of claims 1 to 5, in particular for Manufacture of separating membranes for electrical lead collectors, d u r c h g e k It is indicated that a wetting agent is used in the material a PH value below about 3 makes it hydrophilic. 11. The method according to claim 10, d a d u r c h g e k e n n z e i c Note that a wetting agent is used which is an ethoxylated fatty acid amine contains. 12. The method according to claim 11, dadurchgekennzeic hnet that a wetting agent is used which contains a substance approximately of the formula contains, where R is essentially CH3 (CH2) 11 and N = 2. 13. The method according to claim 11, d a d u r c h g e k e n n z e i c It does not mean that a wetting agent is used which has a substance of the general formula (CH2cH20) - NR - (CH2CH2O) yH, where x and y are preferably each 2 and R is, for example, CH3 (CH2) 11 14. The method according to any one of claims 1 to 4, d u r g e k e n n n z e i c h n e t that as a surface-active substance a Impregnation agent is used, which makes the fine-pored end product hydrophobic. 15. The method according to claim 14, d a d u r c h g e k e n n z e i c It should be noted that an impregnating agent is used which is a long-chain polymer of dialkyl or arylalkyl siloxane groups. 16. The method according to claim 15, d a d u r c h g e k e n n z e i c Note that the impregnation agent contains a silicone resin. 17. The method according to claim 16, d a d u r c h g e k e n n z e i c n e t that as an impregnation agent a material is used that in its composition essentially that of the trade name Silicone M 492 corresponds to the product sold. 18. The method according to claim 16, d a d u r c h g e k e n n z e i c It should be noted that the impregnating agent used is a material whose composition essentially corresponds to the product sold under the trade name Silicone R 205. 19. The method according to any one of the preceding claims, d a d u r Note that the surfactant interacts with the solvent is mixed.