DE19720694A1 - Process for continuous production of surface-modified products - Google Patents

Abstract

The process for continuous production of surface-modified products involves forming an endless product with the required cross-section by moulding a polymer and activating the surface in a pretreatment stage. The activated product is coated and cut to the required length. Also claimed is equipment for this process, comprising an extruder, a pretreatment unit, a treatment or coating unit and a finishing unit.

Description

The invention relates to a method and an arrangement for continuous Nuclear production of elongated products whose Surface was modified by a post-treatment to be her agreed to give desired properties. The invention relates continue to use the process products.

Extrudates from polymeric materials can be used in a wide variety of ways Profiles are produced, e.g. B. as compact, rigid strands with square, rectangular or circular cross-section or with Cross sections of more complicated geometry. You can use it as tapes predominantly have a flat structure or hoses as hollow profiles or be pipes.

It is not uncommon to find the extrudate after extrusion to give desired surface properties. That is e.g. B. at Extrudates the case ultimately for biotechnology or medicine technical uses are intended and therefore biocompatible modes infected, for example hydrophilic or hemocompatible and bacteria-proof. A bioactive process Coating the surfaces of substrates and in particular of Polymer substrates is in the German patent applications 197 00 080.0 and. . . (O.Z. 5192). This will be Substrate first subjected to a pretreatment by which it is acti fourth. The pretreatment is followed by a coating Graft polymerization with one or more appropriately radio tionalized olefinically unsaturated monomers.

Various methods are suitable for pretreating the substrate:

• (1) exposure to UV light;
• (2) treatment with a high frequency or microwave plasma;
• (3) activation with a corona device;
• (4) activation by electron or gamma rays (e.g. from a cobalt 60 source);
• (5) flaming the surface;
• (6) treatment with strong acids or strong bases.

Preferred activation methods are those mentioned under (1) and (2).

At least one monomer of the general formula is then induced by radiation onto the activated surface for coating

R- (A) _a ,

polymerized, where in the formula R denotes a mono- or di-olefinically unsaturated organic radical, for example a hydrocarbon radical, with the valence a ,
A is a carboxyl group -COOH, sulfuric acid group -OSO ₂ OH, sulfonic acid group -SO ₃ H, phosphoric acid group -OPO (OH) ₂ , phosphonic acid group -PO (OH) ₂ , phosphoric acid group -OP (OH) ₂ , phenolic hydroxyl group or a salt or an ester designated one of the groups mentioned, and
a represents an integer from 1 to 6, preferably from 1 to 3.

Of the numerous bioactive graft coatings on this Ways can be applied to the activated substrate those named, which lead to coatings, on the one hand Carboxyl and / or carboxylate groups and on the other hand sulfonic acid have re and / or sulfonate groups. There are under the aspect of Compatibility with regard to the groups mentioned three possible Two combinations, namely carboxyl and sulfonic acid groups, carb oxyl and sulfonate groups as well as carboxylate and sulfonate groups, further two combinations of three, namely carboxyl, carboxylate and Sulfonate groups and carboxyl, sulfonic acid and sulfonate groups pen. All of these combinations characterize useful designs forms of the procedure. Of course it is also possible to use monomers use whose functional groups according to the graft polymer  tion can be changed. So you can z. B. after the acrylamide building block sluggish by hydrolysis in acid medium in the acrylic acid building block convert. You can also by carboxyl and sulfonic acid groups Neutralize (e.g. in phosphate buffers) as well as carbonic ester and sul fonic acid ester groups by hydrolysis in carboxylate or sulfonate convince groups.

The subject of German patent application 197 00 079.7 is a Ver go to the hydrophilic coating of substrates, where one on the surface of polymeric substrates after the same activation pretreatment radiation-induced hydrophilic monomers grafting lymerized.

Both of these methods can be applied to substrates (or objects) different dimensions and different geometry be turned. The discontinuous implementation of this or else Similar multi-stage processes are labor and time intensive. At predominantly two-dimensional, elongated objects, like tubes or catheters, there is a continuous Fer on. It is therefore an object of the invention to provide a continuous Lich process for the production of elongated, by a Aftertreatment appropriately modified objects as well an apparatus arrangement for performing this method to deliver.

According to the invention, this object is achieved by a method in which one (1) has an endlo body with the desired cross section, (2) the endless one Body activated in a pre-treatment stage, (3) the activated endless body coated in one treatment stage and (4) the coated endless body in a finishing stage in counter divides stands with the desired length.

An apparatus arrangement consisting of: an extruder unit, a pretreatment unit, a treatment processing or coating unit and a packaging unit.

Allow the new method and the associated apparatus arrangement  the inexpensive manufacture of elongated, by Nachbe modified objects in large numbers. If you choose Appropriate activation methods can already be proven art fabrics while maintaining their mechanical properties and their Form additionally biocompatible, e.g. B. hydrophilic and hemocompatible and / or modified to repel bacteria. The procedure and the arrangement can be designed flexibly. The shape can can be varied by different extrusion nozzles. The Vorbe action level and the corresponding equipment unit can be the each desired pretreatment method can be adapted. Give If necessary, modules can be provided which, when the Pretreatment method can be exchanged. The treatment level too and the treatment or coating unit can the methodi and technical requirements for the manufacturing pro zeß and the product properties are easily adjusted, given if necessary, again by modular construction.

Suitable as substrate materials for the objects to be manufactured thermoplastic materials, such as polyurethanes, polyamides, Polyesters and ethers, polyether block amides, polystyrene, polyvinyl chloride, polycarbonates, polyorganosiloxanes, polyolefins, polysulfo ne, polyisoprene, polychloroprene, polytetrafluoroethylene, polyacryla te, polymethacrylates, corresponding copolymers and blends as well natural and synthetic rubbers, with or without radiation sensitive groups. Depending on the intended use of the items hard and rigid, tough or elastic materials are used.

In the molding stage, the substrate materials are extru into the desired shape of an endless body (or extrudate) brought. The usual extruders, such as single or double, are used screw extruders in which polymer blends are also manufactured or property-modifying additives can be mixed. The shape is mainly due to the geometry of the extrusion determined tool. If necessary, the extrudate is still hot ß, deformable condition at regular intervals for later Structural features required are stamped on or in issued otherwise, e.g. B. recesses or recesses.  

The shaping stage is expediently followed by a cooling stage or a cooling unit in the apparatus arrangement in which the extru dat to the optimal temperature for the activating pretreatment is cooled. Depending on the thickness of the extrudate, this can be done by cold blow or direct contact with a suitable coolant happen.

The tempered extrudate is activated in the pretreatment stage. Since the activation methods, of which UV radiation, plasma and corona treatment are preferred, require very different conditions and equipment requirements, a modular design is appropriate here. The UV radiation generally requires rays of the wavelength 100 to 400 nm, in particular from 150 to 310 nm. Particularly suitable radiation sources are excimer UV lamps from Heraeus, D-63801 Kleinostheim, for example with F ₂ , XeF ₂ , ArF, XeCl, KrCl and KrF as the lamp medium largely provide monochromatic, continuous radiation. The presence of small amounts of oxygen is advantageous for activation. Suitable partial pressures are between 2 × 10 ^-5 and 2 × 10 ^-2 bar. One works for example in a vacuum of 10 ^-4 to 10 ^-2 bar or, technically simpler because of the sealing problem, using an inert gas such as nitrogen or argon with an oxygen content of 0.02 to 20 per mille. The optimal irradiation time depends on the substrate, the composition of the surrounding gas medium, the wavelength of the radiation and the power of the radiation source. It is generally from 1 second to 10 minutes and can easily be determined experimentally. The substrate heats up only marginally, and even with rays at the hard end of the wavelength range mentioned there are no undesirable side reactions which could damage the exposed surfaces. In general, three radiation sources arranged along and parallel to the direction of movement of the strand at an angle of 120 ° are sufficient. In the case of longer irradiation times, it may be expedient to arrange one or more further groups of three radiators following the first group.

Alternatively, the activation can also be effected by a high-frequency or microwave plasma in an air, nitrogen or argon atmosphere. Suitable equipment provides z. B. Technics Plas ma, D-85551 Kirchheim. The exposure times are generally 30 seconds to 30 minutes, preferably 2 to 10 minutes. The energy input is usually 100 to 1,000 J / cm ² .

Other activation methods can also be used, e.g. B. Flaming, which with particularly short exposure times, preferably 0.5 to 2 seconds. Suitable devices with a barrier attack The front is supplied by Arcotec, D-71297 Monsheim. Farther Corona treatment leads to the desired activation. Appropriate nete devices can be obtained from Softal, Hamburg. Fer The extrudate can then be activated by a bath with strong Conduct acids or bases, e.g. B. by concentrated sulfuric acid Room temperature or by dilute sodium hydroxide solution at 20 to 80 ° C. in the Following an acid or alkali treatment, the extrudate must be based Lich rinsed with water and dried if necessary.

In the following treatment or coating step, the activated surface applied a coating that the desired properties, e.g. B. hydrophilic or bacteria-repellent Effect, conveyed. This can be caused by radiation-induced graft poly merization happen either with monomers as in those mentioned German patent applications 197 00 080.0 and 197 00 079.7 or with pre-formed coating polymers, as in the German Patent applications 197 00 081.9 and 197 00 82.7 are described. At a special embodiment of the radiation-induced grafting according to German patent application 197 15 449.2, the polymer sub strat prior to grafting with a photoinitiator and a monomer pre-treated. Furthermore, the desired monomers or graft ble polymers in the presence of suitable, e.g. B. peroxidic Radi Grafting thermally induced grafted onto the polymer substrate will.

Before coating, however, the pretreated extrudates expediently 1 to 20 minutes, preferably 1 to 5 minutes of on effect of oxygen, e.g. B. exposed in the form of air. Then The surfaces are made using known methods such as dipping,  Spraying or brushing, with solutions of or according to the invention using monomers or the preformed coating polymer coated. Water and water-ethanol Ge have been used as solvents Mix proven, but other solvents can be used, if they have sufficient solvency for the monomers or the Have coating polymer and the substrate surfaces well wet. Depending on the solubility of the monomers and the desired layer thickness of the finished coating can be the concentrations of mono mer or the coating polymer in the solution 0.1 to 50 Weight percent. Solutions with levels of monomers or Coating polymer of 3 to 10% by weight, for example about 5 % By weight have proven themselves in practice and generally result coherent in one pass, the substrate surface kende coatings with layer thicknesses that are more than 0.1 microns can. In practice of the method according to the invention this is done Extrudate usually through a bath or past spray heads.

After evaporation of the solvent or even during the Ver steaming is the graft polymerization or copolymerization of the monomers applied to the activated surfaces or the Grafting of the coating polymer initiated and effected, expediently ßig by rays in the short-wave segment of the visible range or in the long-wave segment of the UV range of the electromagnetic radiation. Z. B. again the radiation of a UV excimers of wavelengths from 250 to 500 nm, preferably from 290 up to 320 nm. Mercury vapor lamps are also suitable, provided that they emit significant amounts of radiation in the areas mentioned Ren. The exposure times are generally from 10 seconds to 30 minutes, preferably 2 to 15 minutes. Regarding the UV Exci mer and their arrangement apply the explanations for the activating Pretreatment analogously.

If necessary, the coated extrudate is passed through a Conversion stage or a conversion unit of the apparatus arrangement in the functional groups of the polymer coating into others functional groups are converted. So you can carboxyl and / or Sulfonic acid groups in carboxylate and / or sulfonate groups around convert by passing the coated extrudate through a bath with ver  thin sodium hydroxide solution conducts.

An alternative to the coating described is in EP-B1-0 514 047 disclosed. It is a co-extrusion-like ches method and a corresponding device, whereby strangge completely or partially pressed profiles (extrudates) with polymer solutions be coated. The essential feature of the device is a coating block connected to the extrusion die, which is so is designed so that it takes up the extrudate and together with it works.

In the subsequent assembly stage, the coated Extrudate to the required length of the ultimately desired Brought items. Hoses are e.g. B. rolled up and cut The assembly stage and the associated assembly unit belong to the state of the art and offer process and apparatus technically no special features.

The throughputs through the various stages or units must be be adapted to each other so that trouble-free operation is possible is. Buffer zones or buffer units are expediently provided, the fluctuations in throughput in a certain level or unit compensate as a result of malfunctions until a stationary, disturbing is achieved.

Find products made by the process of the invention a ver corresponding to the set surface properties application, preferably for biotechnical or medical purposes or in the field of hygiene articles. Bioactive, e.g. B. bacteria-resistant Send, cell proliferation-inhibiting, hydrophilic and / or compatible with blood discontinued products are u. a. Hose connections, catheters, Probes and invasive devices or apparatus. With hygiene articles These are products in which, according to the type and or or the location of their use bacteria-free or bacteria-free pointing surfaces are desired. Such articles are e.g. B. professional le as handrails or for windows in public buildings as well Components in the field of intensive care medicine.

Claims (6)

1. A process for the continuous production of elongated, modified by a post-treatment, characterized in that (1) in a molding step from a polymer produces an endless body with a desired cross-section, (2) the or a surface of the endless body in a Vorbe action level activated, (3) coated the activated endless body in a treatment or coating stage and (4) divides the coated endless body in a finishing stage into objects of the desired length. 2. The method according to claim 1, characterized in that the Er certificate is bioactive coated. 3. The method according to claim 1 or 2, characterized in that activation by UV radiation, corona treatment, treatment with a high frequency or microwave plasma and / or flame he follows. 4. The method according to claim 1 or 2, characterized in that the coating initiated by UV radiation or thermally ini tied graft polymerization with olefinically unsaturated monomers or grafting a preformed polymer. 5. Use of the according to the method of claims 1 to 4 herge manufactured products for medical or biotechnical purposes or in the field of hygiene articles. 6. Apparatus arrangement for by the method according to the claims Chen 1 to 4, characterized by an extruder unit, a prep handling unit, a treatment or coating unit and a packaging unit.