EP2028961B1 - Method and device for functionalising functionalising the surfaces of adhesive closing parts - Google Patents

Description

The invention relates to a method for surface functionalization of adhesive closure parts, with the features in the preamble of claim 1. The invention further relates to an apparatus for carrying out this method.

By the EP 1 082 031 B1 a method for producing adhesive closure elements having adhesive closure parts made of plastic materials is known, wherein the adhesive closure member is provided with the adhesive fastener elements at least partially with a coating whose layer thickness is chosen such that it does not affect the subsequent function of the adhesive closure. The coating on the adhesive closure part is formed by a so-called sol-gel process, preferably based on SiO ₂ and / or TiO ₂ -modified SiO ₂ . The applied over said sol-gel process coating is foam-repellent, which brings advantages, if the known adhesive closure part is used in the lathering of seat cushion parts. Although the applied coating is nanocomposite, that is, the layer thickness can be extremely low, in particular, has only a few molecular strengths of the respective coating agent, the pertinent coating is not resistant to abrasion and thus not resistant to aging.

By the EP 1 077 620 B1 is a fastener part, in particular for foaming in upholstery parts of vehicle seats, known in their manufacture, wherein on one side of the fastener part an adhesive primer is applied. If the known fastener part is made of a polyamide material, the primer is formed from resorcinol and / or at least one of its derivatives or, if the fastener part consists of a polyolefin material, is used as primer polyurethane or a polymer which is a Nachvernetzung of curable Resins arise. In this way, a kind of primer layer is formed on the adhesive closure part as an additional coating, which forms a high-strength connection with the respective foam material, even without the use of corresponding adhesive agents. The well-known solution of an application coating can also rub off.

To counter that, is in the DE 101 23 205 A1 have already described a method for producing a fastener part having a plurality of integrally formed with a carrier fastener elements are provided in the Verhakungsköpfe the fastener elements with a head part of a hardened filler material, in the form of a thermosetting molding composition, preferably in the form of an acrylate, particularly preferably in Form of a urethane diacrylate. If the pertinent urethane molding material is cured, an adhesive closure part is created, which can withstand high temperatures and mechanical stresses well on the one hand and on the other with appropriate design leads to improved adhesion and peel strength values. The applied thereto high-strength additional coating, however, builds on the fastener elements correspondingly large, which in turn precludes a desired miniaturization of fastener parts, which today attempts to accommodate several thousand fastener elements on a square centimeter of carrier material of the fastener part.

The DE 199 06 008 A1 describes a method for the surface functionalization of adhesive closure parts which form a repeatedly openable and closable adhesive closure with correspondingly formed adhesive closure parts, wherein the surface energy of the adhesive closure part is modified with the aid of high energy using a proton and / or electron exchange medium such that coating-free and aging-resistant chemical physical properties of the fastener part material material are adjustable by attaching functional groups of the exchange medium to the fastener part material.

Based on this prior art, the invention is therefore based on the object to further improve the known methods and related devices that in a cost effective manner miniaturizable adhesive closure parts are functionalized in large flow quantities such surface technology that a variety of surface and structural properties of various kinds can be produced with only one basic concept of treatment steps.

This object is achieved by a method having the features of claim 1, as well as a device according to the feature configuration of claim 11.

According to the characterizing part of claim 1, it is provided that collectors or basic electron donors are used as the proton and / or electron exchange medium.

In the method according to the invention is by means of a proton and / or electron exchange medium, in particular in the form of donors and collectors, the surface energy of the adhesive closure part using high energy modified such that coating-free and aging resistant, the chemical-physical properties of the adhesive closure material are adjustable by attaching functional groups of the exchange medium to the adhesive fastener part material.

So-called Brönsted acids, which act as proton donors, and so-called Lewis bases, which can donate electrons to other materials as a donor, such as the plastic material of an adhesive closure part, have proven to be particularly versatile. Furthermore, there are protons and / or electrons collecting collectors in the plastic material of the adhesive closure part, which influence the surface energy of the adhesive closure part in a comparable manner to a redox effect, which in turn creates the possibility that function groups can interact with the adhesive closure part by using high-energy functional groups of exchange media.

By attaching functional groups of the exchange medium to the fastener sub-material from the surface and thus intruding into the fastener sub-material, a substantially coating-free construction is achieved, so that the surface functionalization is carried out on small scales, which in turn accommodates the desired miniaturization of the fastener parts together with their fastener elements , Since the functional groups are attached to the adhesive closure part in the molecular range and in so far interact with the other plastic material of the same, the pertinent mode of operation proves to be resistant to aging, so that there is no need to fear that after a longer storage time for the adhesive closure parts before their use in the production of the user the desired surface modification is lost. The chemical-physical properties to be set are defined in a broad framework. Thus, the adhesive closure part of its hardness or softness can be set as functional as with respect to a desired temperature resistance. Resistance to chemicals of any kind is then as functionally adjustable as a desired reaction pattern with third-party products, for example in the form of polyurethane foam, the starting material for upholstery production.

Due to the affiliation of chemical functional assemblies to the material of the adhesive closure part, a specific interaction with the respective component can be achieved insofar as the adhesive closure part is to be used. For example, it is possible to make the adhesive closure part flame resistant by affiliation of corresponding functional modules; an application criterion for the respective fastener part, as far as it is used in aerospace engineering applications. If the respective function module has phosphor components, the respective adhesive closure part can be used well in the creative design sector, for example to enable luminous color designs. Due to the aforementioned change in the surface energy, it is also possible to achieve improved adhesion of corresponding adhesive closure parts to form the adhesive closure, to which capillary technologies which are otherwise difficult to implement in the prior art (US Pat. DE 102 07 194 C1 ) are described.

Furthermore, electrical discharge properties of the adhesive closure part can be improved in the case of current or other information transport via the respective functional assemblies to be used. A large number of possible applications is currently not yet covered, and will be the subject of further technical development using the method according to the invention described above.

As a preferred device for carrying out the method is one according to the feature design of claim 11, wherein the adhesive closure elements of the adhesive closure member are produced by means of a forming wire, wherein on one side of the forming wire, the plastic material for the closure elements in the form of openings of the screen can be fed, and wherein the opposite side of the forming wire, preferably In situ, the exchange medium can be supplied to the mold openings, being used as a proton and / or electron exchange medium collectors or basic electron donors. The pertinent device allows in a particularly economical manner to carry out the manufacturing process according to the invention and in particular allows a process-safe process sequence. With the pertinent device can be quasi-continuously produce large quantities of adhesive closure parts with surface modification production safe.

Further advantageous embodiments of the method according to the invention are the subject of the other dependent claims.

The single figure shows an example of a highly simplified schematic and partially cut drawn side view of an apparatus for performing the method according to the invention.

The figure shows a schematic representation of parts of a device for carrying out the method according to the invention, with an extruder head 1 as a feeder for in plastic or liquid state, in particular thermoplastic material, which corresponds to a strip whose width of that of the adhesive closure part corresponding to the gap between a pressure tool and a mold is supplied. As a pressure tool, a pressure roller 3 is provided. The molding tool is a molding roll designated as a whole by 5. Both rollers are driven in the direction indicated in the figure with curved arrows 7 and 9 directions of rotation, so that between them a conveying gap is formed, through which the plastic strip is conveyed in the transport direction, while at the same time formed in the gap as a shaping zone, the plastic tape to the carrier 10 of the fastener part and the carrier 10 at the side adjacent to the forming roll 5 through the forming elements of the forming roll 5, which obtains the necessary shape to form interlocking means.

For this purpose, the forming roller 5 on the periphery of a screen 11, with individual mold cavities 12. A pertinent mold cavity 12, which is bounded on both sides by mold openings 12a, b respectively, is with the other mold cavities 12 along the mold roll 5 with its screen 11 outside circumference preferably distributed regularly, the distribution and the number are freely selectable. The respective mold cavity is designed in the manner of a rotation hyperboloid, so that in this respect correspondingly shaped stem parts 13 arise, which are integrally connected with their respective foot end to the belt-like carrier material 10 and the other free end opens into a circumferentially broadened head portion 15. Both stem part 13 and head part 15 each form an adhesive closure element for the total adhesive closure part, which forms a repeatedly openable and closable adhesive closure with correspondingly shaped corresponding closure parts of another, not shown, fastener part. Closures generated to this effect have also become known under the brand name Kletten ^® -Zeilverschlüsse.

The forming roller 5 is provided with apertures in the form of media channels 17, which are oriented from their longitudinal orientation to the center 19 as a rotation axis of the forming roller 5. Inside the forming roller 5 and in concentric arrangement with the same, 21 denotes a high energy source, which is symbolically represented. Furthermore, between the outer sheathing of the high energy source 21 and the inner circumference of the forming roller, a void, which serves the supply and the temporary storage of the exchange medium, optionally additionally physical parameters of the pertinent empty and working space are adjustable, for example in the form of pressure and temperature, humidity etc .. Furthermore, via the pertinent empty or working space 23, the possible supply of gas and fluid media for performing the method instead, for example, to accelerate the pertinent work progress. Via the media channels 17 as well as over the room 23 can be Add rinsing media to clean off the overall manufacturing equipment from any residue in the process processing.

As a plastic material for each adhesive closure part to be produced, polyolefins have proven to be particularly suitable. The group includes, for example, polyethylenes, polypropylenes, polybutenes, and polyisobutenes and poly (4-methyl-1-pentene) s, polymers of the higher alpha-olefins, e.g. Poly (1-hexene), poly (1-octene) or poly (1-octadecene). To the pertinent polyolefins also copolymers of different olefins, e.g. which are recognized by ethylene with propylene as belonging. Another good feedstock for the molded fastener parts is polyester.

The proton and / or electron exchange media used are substances and substance groups according to the following chemical overview list, where I denotes the so-called hard bases, II the soft bases and III the limiting cases of bases. With IV the hard acids are designated, with V the soft acids and with VI the borderline cases on suitable acid materials. I II H ₂ O OH ^- F ^- R ₂ S RSH RS ^- AcO ^- SO ₄ ^2- Cl ^- I ^- R ₃ P (RO) ₃ P CO ₃ ^2- NO ₃ ^- RA CN ^- RCN CO RO ^- R ₂ O NH ₃ C ₂ H ₄ C ₆ H ₆ RNH ₂ SiOH H ^- R ^- III IV ArN H ₂ C ₅ H ₅ N H ⁺ Li ⁺ Na ⁺ N ₃ ^- Br K ⁺ Mg ²⁺ Ca ²⁺ NO ₂ ^- Al ³⁺ Cr ²⁺ Fe ³⁺ BF ₃ B (OR) ₃ AlMe ₃ AlCl ₃ AlH ₃ SO ₃ RCO ⁺ CO ₂ HX (hydrogen-binding molecules) V VI Cu ⁺ Ag ⁺ Pd ²⁺ Fe ²⁺ Co ²⁺ Cu ²⁺ Pt ²⁺ Hg ²⁺ BH ₃ Zn ²⁺ Sn ²⁺ Sb ³⁺ GaCl ₃ I ₂ Br ₂ Bi ³⁺ BMe ₃ SO ₂ CH ₂ carbenes R ₃ C ⁺ NO ⁺ GaH ₃ C ₆ H ₅ ⁺

The classification is based on the pattern that hard acids like to combine with hard bases, as well as soft acids with soft bases. The transitions between hard and soft media are fluid, and the classification is meant to give a rough idea and information about the impact of the exchange media. For example, the possible proton release that occurs in all Brönsted acid-base reactions is classified as a hard acid. The soft bases as so-called donors are again characterized by the fact that, in particular, a plurality of electrons or electron pairs can be emitted in order to be able to perform the surface functionalization for the adhesive closure part in this manner. Basically, so-called collectors are also available for influencing the surface functionalization of the adhesive closure part, which can dissolve electrons and / or protons from the plastic material of the adhesive closure part in the manner of a redox reaction, in order to influence it. but the degree of functionalization achievable thereby clearly recedes over the protons and / or electron donors.

The desired surface modification can be further optimized by the use of a high energy source. In addition to the use of microwave radiation or other high-frequency field, the use of plasmas is possible. As a possible plasma source DC glow discharges come as well as high-frequency discharges and those with microwave character. In order to reduce the heat load on the plastic material to be produced, in particular, the microwave discharge offers, since the equipment cost is low, an electrodeless coupling possible and due to the high ionisierungsgrades of the plasma short process times are guaranteed, which is mandatory for in situ production of the adhesive closure part necessary is.

A pertinent plasma source would then be the designated high energy source 21 according to the figure. By the substrate position of the adhesive closure member in the mold cavities 12 of the forming wire 11, a variety of imaginable plasma modification processes can be performed. Thus, the device shown in the figure, for example, for a so-called. In-plasma process in question, in which the surface to be functionalized is located directly in the plasma zone. Likewise, a so-called down-stream method would be conceivable in which a process gas is passed through a plasma zone and then fed to the substrate as a fastener part with its free head ends of adhesive fastener elements. In particular, by adjusting the distance over the drum diameter of the forming roller 5, the thermal load for the substrate in the form of the adhesive closure part can be adjusted so low.

If the process gas used in the plasma zone to implement too quickly or immediately completely, a so-called. After-glow method is possible, wherein an inert carrier gas, for example in the form of nitrogen gas is passed through the plasma zone and activates the process gas, which only after the Plasmazone can be supplied. The then indirectly activated working gas serves the desired surface modification.

Since the drum-like production device can be closed at the end of the drum, the process gas guide can be made and set in the empty or working space 23 via appropriate inlets and outlets (not shown). For process acceleration, it may be advantageous to supply the process gas under a correspondingly high pressure in the space 23. Instead of the plasma generation source can be provided for the inventive manufacturing process, a dielectric barrier discharge, with a modified field source as a high energy source 21, which builds from the center of the molding roll 5 of a dielectric field in the direction of the substrate top of the adhesive closure member. Further, a treatment gas mixture is quasi continuously introduced into the empty and working chamber 23, which preferably consists of a carrier gas and a reducing gas and / or an oxidizing gas, at a pressure which in the present case may be approximately equal to the atmospheric pressure. As oxidizing gases are here in particular CO ₂ or N ₂ O and as reducing gas H ₂ in question. Also, it has proved to be favorable to settle the content of the oxidizing gas in the mixture in a range of 50 to 2000 ppmv and the content of the reducing gas is preferably in a mixture in a value range of 50 to 30,000 ppmv.

With the last-mentioned surface treatment method, amino, amido, and / or imido groups and compounds can be used, in particular as basic electron donors, which, as a functional group, introduce an NH.sub.3 group on the upper side of the adhesive closure part Asymmetric urea bonding allowed, which has a further reactive group to which the polyurethane of foam materials can settle in the foam pad area, which in such a way leads to a very good connection of the adhesive closure part in the molded foam. A corresponding cover material can then be foamed in via a corresponding adhesive closure part Adhesive closure part are releasably connected again, which forms the asymmetric urea bond with said foam material.

In addition to the Herstelleinsatz a screen drum according to the figure, it is also possible to unwind the Formsiebanordnung in a plane and the forming wire can then be passed through appropriate devices, which then generate the corresponding surface modification as described above. In particular, then the sieve in the manner of a conveyor belt via pulleys with top and bottom strand can be formed, the upper strand of the shaping is used and the lower strand of the demolding of the adhesive closure member from the individual mold cavities.

Also, the fastener part does not need to be provided with circumferentially widened head ends, as shown in the figure, to provide such an interlocking opportunity. Rather, modern adhesion systems can thus obtain a surface modification. So exemplifies the DE 100 65 819 C1 a method for producing adhesive closure parts, in which a carrier material is provided in at least a portion of its surface with protruding from their plane fastener elements or adhesive elements in which a plastic material forming the elements is applied to the carrier element as a support member 10, wherein the elements at least in a partial area are formed free of mold, in which the plastic material is deposited by means of at least one applicator in successive dispensed droplets. Although the applicator device discharges the plastic material with a droplet volume of only a few picoliters via its nozzle, a fast process flow can be realized in this way, so that an adhesive closure part is generated in a very short time. An adhesive closure part produced in this way can also be surface-modified with the described methods.

The device shown in the figure can also be miniaturized from the mold cavities 12 in such a way that adhesive elements can be produced whose adhesion occurs predominantly by means of van der Waals forces. A pertinent closure system is exemplary in the DE 10 2004 012 067 Al demonstrated. Despite the degree of miniaturization achieved in this way, it is then possible with the pertinent inventive solution to also modify such nano-adhesive closure parts from the surface by default. The device described above is particularly suitable from the front-side head closure material side to influence the respective adhesive closure part. In principle, however, all components of the closure part can optionally be functionalized from their surface with different types of devices, which also applies, in particular, to the back side of the carrier of the closure part facing away from the elements or to the top side of the stem or stem material extending between the carrier and the underside of the closure head extends. For the pertinent surface functionalization, the adhesive closure part with the component or component side that is to be functional is thus exposed to the functionalization source, which can take place in closed systems but also in open systems in the passage for a quasi-continuous functionalization.

Claims (11)

1. A method for functionalising the surfaces of adhesive closure parts, that with correspondingly formed adhesive closure parts form an adhesive closure that can be opened and closed repeatedly, the surface energy of the adhesive closure part being modified using high energy by means of a proton and/or electron exchange medium such that the physiochemical properties of the adhesive closure part material can be set to be free of coatings and resistant to ageing by functional groups of the exchange medium attaching to the material of the adhesive closure part, characterised in that collectors or basically acting electron donors are used as proton and/or electron exchange medium.
2. The method according to Claim 1, characterised in that the attachment process of the functional groups is supported by the influence of high energy, using

   - high frequency radiation such as microwave radiation,

   - electric fields such as dielectric barrier discharge, and

   - plasma-supported fields, as are produced when using a low pressure or high pressure plasma.
3. The method according to Claim 1 or 2, characterised in that the attachment process of the functional groups can be controlled using insert and/or reaction gases.
4. The method according to any of Claims 1 to 3, characterised in that the attachment process of the functional groups can be controlled by means of temperature and/or pressure gradients.
5. The method according to any of Claims 1 to 4, characterised in that the plastic material of the adhesive closure part to be functionalised is a thermoplastic, in particular polyolefins and/or polyesters.
6. The method according to any of Claims 1 to 5, characterised in that amino, amido and/or imido groups and compounds are used as basic electron donors.
7. The method according to Claim 6, characterised in that using the basic electron donors, asymmetrical bonds with the primary material of the adhesive closure part are formed, and preferably asymmetrical urea bonds are produced.
8. The method according to Claim 7, characterised in that the asymmetrical urea bond is produced by attachment of the respective closure part to foam materials, such as polyurethane foam.
9. The method according to any of Claims 1 to 8, characterised in that the binding of the functional groups to the adhesive closure part takes place in situ.
10. The method according to any of Claims 1 to 9, characterised in that the respective adhesive closure part is produced by means of a screening process.
11. A device for executing the method according to any of Claims 1 to 10, the closure elements (13, 15) being able to be produced by means of a mould screen (11), on one side (12a) of the mould screen (11) the plastic material for the closure elements (13, 15) being able to be supplied to mould openings (12) of the screen, and on the opposite side of the mould screen (11), preferably in situ, the exchange medium being able to be supplied to the mould openings (12b), characterised in that collectors or basically acting electron donors are used as proton and/or electron exchange medium.

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