EP1223826B1 - Method for producing an adhesive closing component - Google Patents

Abstract

A method produces an adhesive closing component having a carrier with a plurality of interlocking means on one of its two sides. An adhesive is applied to the opposite side. A silicone-containing separation layer is at least partially applied on the side of the carrier provided with the interlocking means. The interlocking means are formed from stems provided with enlargements on the ends. The silicone-containing separation layer is applied in the cavities of the enlargements in a reinforcing manner. The enlargements form individual interlocking heads. The stems are essentially kept free from the silicone-containing separation layer. An adhesive closing component with adhesive means is improved such that the component can be produced cost-effectively and efficiently. Handling is simplified, and pulling-off characteristics are improved.

Description

The invention relates to a method for producing an adhesive fastener part having a plurality of interlocking means formed with a carrier on one of its two sides, wherein on the opposite side an adhesive agent is applied and wherein on the side of the carrier with the interlocking means at least partially a silicone-containing release layer is applied ,

The adhesive fastener parts produced in this way can be wound into roll packages in the form of strip or sheet material, the adhesive agent being usually provided in the form of a rubber-based hot-melt pressure-sensitive adhesive with a backing paper in order to prevent the adhesive agent from becoming firmly bonded to the underlying interlocking means. The adhesive agent later serves to fix the fastener part depending on its intended use on a floor or on a diaper material, provided that the fastener part serves to fasten a carpet material or as a closure part for a baby diaper or the like. Since the fastener parts used in production technology on a large scale be connected to the diaper material for their processing, for example in the field of baby diapers on automatic processing machines, with very high production speeds be driven, the covering of the adhesive agent is often a problem, since this must be deducted before the actual processing of the adhesive closure part, removed and disposed of. For example, if the thin covering agent peels off in the form of a masking paper, and the adhesive fastener portion is supplied with the adhesive agent together with the remaining masking paper of the processing machine, the entire production process is interrupted, resulting in high failure costs.

1. 1. eine Schlaufenlage auf seiner ersten Hauptfläche, wobei die Schlaufenlage mehrere flexible Schlaufen aufweist, die geeignet sind, mit dem komplementären Hakenteil des Haken- und Schlaufenverschlusses in lösbarem Eingriff zu stehen und wobei die Schlaufen an einem Träger verankert sind und
2. 2. eine Selbstkleberschicht auf seiner zweiten Hauptfläche.

By DE-U-94 21 906, as the closest prior art, a coverless loop fastener material unit has become known, as well as a manufacturing method for producing the same having one or more multi-layer loop fastener material layers for the loop portion of a hook and loop fastener, wherein the loop fastener material is in the order indicated :

1. A loop ply on its first major surface, the loop ply having a plurality of flexible loops adapted to releasably engage the complementary hook portion of the hook and loop fastener and wherein the loops are anchored to a wearer and
2. 2. a self-adhesive layer on its second major surface.

In this known solution, the loop closure material is disposed in the unit so that the adhesive layer of an overlying portion of the loop closure material is in direct contact with the loop ply of an underlying portion of the loop fastener material, the loops being such that upon removal of the overlying portion of the loop fastener material Loop closure material from the unit the loops taken from the adhesive straighten up and present the underlying section in an operable state. In order for the pertinent effect to occur, a separation control agent is incorporated into the material of the loop layer, it also being possible to use reactive silicones in the known solution. Accordingly, the complete loop material must be provided with the effective separation control agent to obtain the described effect. This means a high level of silicone-containing separation control material, which makes the known solution expensive and expensive to manufacture. In spite of the so far complete siliconization, it may happen beyond that the respective loop of the loop material is in contact only with a small contact surface with the respectively overlying adhesive layer of the carrier with the entangling means in the form of loop material. Accordingly, the adhesion forces are then smaller than those in the vicinity of the closure material, in which the loops are more or less full surface in contact with the adhesive agent. Due to this very different characteristics, it then comes to a different peel with different peel forces, which makes it difficult to handle the rolled-up closure material. Furthermore, a rewinding of the loop closure unit under appropriate arrest of the material layers is difficult.

Starting from this closest prior art, the present invention seeks to further improve a fastener part with adhesive agent to the effect that this can be produced inexpensively and efficiently with simplified handling and Abziehcharakteristik. This object is achieved by a method having the features of claim 1.

Characterized in that according to the characterizing part of claim 1, the interlocking means of end-thickened stems are formed and that in the wells of the individual Verhakungsköpfe forming thickening reinforced the silicone-containing release layer is applied and the stalks are kept substantially free of the silicone-containing release layer can be with still achieve the desired Abwickelcharakteristik for the tape-like adhesive closure part a low material use of silicone-containing release layer material or separation control agent. Since the silicone-containing release layer is distributed in substantially equal portions distributed in the respective frontal depression of Verhakungskopfes, moreover, a uniform opening and Abwickelverhalten is achieved, so that there is a uniform force distribution of the adhesive forces between adhesive layer and hook material. It is also surprising for a person skilled in the art that he achieved not only with the measures shown a uniform opening behavior, but that with the manufacturing process according to the invention one also arrives at a fastener part, with which you can make multiple up and Abwickelvorgänge In turn, during rewinding, a corresponding but non-permanent attachment of interlocking means to the overlying adhesive agent material occurs. Moreover, the amount of Trennsilikonmaterial to be used can be optimized so that in any case the associated arresting or peeling forces are so low that the unwinding of the adhesive closure part of the bundle roll for further processing is not endangered or impaired even with the use of machines. Incidentally, the covering material in the form of a cover paper or the like can be completely dispensed with for the adhesive agent, which likewise makes subsequent processing of the adhesive closure part simpler and safer.

In a preferred embodiment of the method according to the invention, silicon acrylates are used as the release layer, a radiation hardening method being provided for the curing. It has been found that, in particular, radiation-curable 100% solvent-free silicone acrylates give very good results and the adhesive agent adheres as little as possible to the silicone acrylate, provided that it has hardened.

In a particularly preferred embodiment of the method according to the invention, the interlocking means consist of end-thickened stems, for their production, a plastic material is supplied to a gap between a pressure tool and a mold and these tools are driven such that the carrier is formed in the gap and conveyed in a transport direction is used in which as the forming element on the mold a continuous cavities exhibiting sieve and in which the interlocking means are formed by the plastic material in the cavities of the screen at least partially solidifies. The pertinent manufacturing method for the carrier is known from DE 198 28 856 C1. As a result, the starting material to be coated in the form of tape or sheet-like adhesive closure parts can be produced very quickly on an industrial scale.

• gasförmigem oder dampfförmigem Zustand oder
• flüssigem, breiigem oder pastenförmigen Zustand oder
• ionisiertem Zustand durch elektrolytisches oder chemisches Abscheiden oder
• festem, insbesondere körnigem oder pulverigem Zustand

auf das Kunststoffmaterial aufgebracht. Dabei hat es sich als fertigungstechnisch besonders günstig erwiesen, für das Strahlenaushärten der Trennschicht mindestens eine UV-Strahlenquelle einzusetzen. Ferner lassen sich besonders gute Ablöseverhalten erzielen, sofern das Klebstoffmittel ein Klebstoff auf Kautschukbasis ist.Preferably, the silicone-containing release coating is in

• gaseous or vaporous state or
• liquid, pasty or paste-like state or
• ionized state by electrolytic or chemical deposition or
• solid, in particular granular or powdery state

applied to the plastic material. It has proven to be particularly favorable as a production technology to use at least one UV radiation source for radiation curing of the separating layer. Furthermore, particularly good release properties can be achieved if the adhesive agent is a rubber-based adhesive.

In a particularly preferred embodiment of the method according to the invention, the silicone separating layer is increasingly applied in the depressions of the thickening heads forming the hooking heads and the stalks are essentially kept free of the silicone separating layer. Since the interlocking heads coated in this way are provided with a kind of sliding layer, the corresponding loops or engagement parts of another fastener part, which together with the first fastener part forms the adhesive closure, slide behind the corners and edges of the interlocking heads, resulting in an improved interlocking behavior, with the result that that higher release forces are necessary to release the adhesive closure while separating the adhesive closure parts. The effect is due to the fact that the loop material no longer comes to rest directly on the hooking heads, but there it slides off due to the release coating and engages in the interstices between the hooking and there then takes place the specific interlocking.

Preferably, it is further provided in the inventive method that a thermoplastic material is used as the plastic material. Furthermore, it is provided in the inventive method that the adhesive closure part is rolled up into transportable containers, so that the adhesive agent is in direct contact with the underlying Verhakungsmitteln.

It has been shown that in the transport direction of the adhesive closure part, the speeds for the coating process between 10 and 100 m / min can be driven. This significantly increases the production speed for the adhesive closure part according to the invention, wherein these production speeds would not be achievable if the adhesive agent were to be provided in the usual way with a cover tape or cover paper.

Fig.1

eine teilweise geschnitten gezeichnete Seitenansicht einer Vorrichtung zur Herstellung des Haftverschlußteiles ohne Klebstoffmittelschichtauftrag und ohne Auftrag der silikonhaltigen Abdeckschicht;

Fig.2

eine schematisch stark vereinfachte Darstellung eines Auftragverfahrens für die silikonhaltige Abdeckschicht;

Fig.3

in prinzipieller Darstellung eine Seitenansicht auf das Haftverschlußteil mit Klebstoffmittelschicht und silikonhaltiger Abdeckschicht.

In the following the invention will be explained in more detail with reference to an embodiment according to the drawing.
It shows in principle and not to scale representation of the

Fig.1

a partially sectioned side view of a device for producing the adhesive closure part without adhesive agent layer application and without application of the silicone-containing cover layer;

Fig.2

a schematically simplified view of a coating method for the silicone-containing cover layer;

Figure 3

in a schematic representation of a side view of the adhesive closure part with adhesive agent layer and silicone-containing cover layer.

1 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 befindliches in plastic or liquid state thermoplastic plastic material, wherein the plastic is supplied as a band whose width corresponds to that of the adhesive closure part to be produced, the gap between a pressure tool and a molding tool. 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 Figure 1 with 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 in the gap, the plastic tape is formed to the carrier 11 of the adhesive closure part and the support 11 at the voltage applied to the forming roller 5 side by the shaping elements of the forming roller 5 receives the necessary shape for the formation of interlocking means.

For this purpose, the forming roller 5 on the periphery of two forming elements in the form of a respective sieve, namely an outer sieve 13 and an inner sieve 15, which abut each other. The mentioned sieves 13 and 15 are inserted into one another in such a way that the cavities formed by the sieve openings of outer sieve 13 and inner sieve 15 are aligned with a common axis.

The thickness of the outer screen 13 is greater than that of the inner screen 15, the cavities in turn are larger in cross-section than the cavities of the outer screen 13. Due to this configuration, the indented in the gap between the pressure roller 3 and mold roll 5 in the cavities plastic is formed in that projecting stems 17 with thickened ends 19 are formed on the carrier 11. The difference in the cross-sectional sizes of the cavities is chosen such that the broadening at the ends 19 is only so large that after partial or complete Hardening of the plastic material, the extraction of the stems 17 from the cavities can be done safely when the carrier 11 is discharged via a Ausziehwalze 21 of the forming roller 5. The adhesive closure part 23 produced in this way is shown partially in a side view in FIGS. 2 and 3, wherein the adhesive closure part 23 is provided with an adhesive agent layer 25 on its rear side. The adhesive agent concerned is preferably a rubber-based adhesive. The adhesive itself is applied to the back of the adhesive closure member 23 in a conventional and therefore unspecified manner. The thickened ends 19 on the stems 17 form the actual entangling means 27, which are to be provided with the release coating. The thickened ends 19 themselves may be calendered for final molding as a hooking head of the entangling means 27 (not shown in detail).

On the side of the carrier 11 with the hooking means 27, a silicone-containing release layer 29 is at least partially applied and then cured. In particular silicone acrylates are used as separating layer 29, a radiation hardening method being used for curing. The curing is based on the polymerization of the CC double bonds of the acrylate groups via a radical chain reaction. While in electron beam curing, the high radiation energy generates enough radicals for the spontaneous polymerization process, UV light has a lower energy compared to the electron beams. Therefore, in the case of UV curing, the addition of a photoinitiator makes sense whose decay provides the required high local radical concentration, which is required for the polymerization. Radical production and immediate chain growth cause a rapid and effective three-dimensional crosslinking of the silicone acrylates with each other even at room temperature.

A fundamental effect in the radical polymerization is the inhibition by atmospheric oxygen. The growing radical chain is broken off by contact with oxygen, because the reaction of the monomer radicals with oxygen proceeds much faster because of the large excess than that with free monomers. The prevented chain growth leads only to short-chain, still liquid polymers, whereby the substrate surface is greasy or sticky and thus unsuitable for further use. However, these effects can be remedied by curing under inert gas. By flushing with nitrogen while the concentration of atmospheric oxygen in the curing zone is lowered into the non-harmful area.

It is particularly environmentally friendly to use silicone acrylates which have a solids content of 100% and can therefore be processed solvent-free. Since no catalyst is needed for curing, poisoning by foreign substances in the substrate can not occur. Accordingly, such a coated adhesive closure part can be disposed of or recycled without harmful environmental impact. In addition to the mentioned electron beam and UV curing process, a thermal curing of the silicone cover is possible and conceivable. The mentioned coating with the silicone acrylate is possible from the gaseous or vaporous state, for example by vapor deposition. Another coating option results from the liquid, pasty or pasty state by painting, dispersion or melt coating and by extrusion, casting or dipping. In the preferred embodiment according to FIG. 2, the silicone coating material is located in a bath 31 and is applied from there via an applicator roll 33 to the thickened ends 19 of the hooking means 27. The direction of rotation of the applicator roll 33 is in Fig.2 with an arrow As well as the continuous transport direction for the carrier 11. The application bath 31 is then followed by the UV curing device designated as a whole by 35. Other coating options are in the form of electrolytic or chemical deposition processes or coating processes of granular or powdery states.

If the thickened head ends 19 of the interlocking means 27 have a production due to a recess, this depression can be increasingly filled with the silicone-containing separating layer means 29. However, it is also conceivable that, depending on the application method, the areas left free by the hooking means 27 are silicone-coated on the upper side of the carrier 11 (not shown). What matters, however, is that the location in the wound state of the fastener member 23 adjacent the adhesive means 25 is disposed opposite to the silicone cover so as to prevent the adhesive from adhering to the underlying tape material.

In practical experiments, it has been found that the peel strength measured in N / cm of a conventional adhesive agent 25 on adhesive elements with silicone is 0.65 and without silicone 4.8. That is, it is possible to deal with siliconized adhesive members having adhesive agent 25 of roll packs (not shown) disposed on the back side without problems, even if the masking paper for the adhesive agent 25 is omitted.

The following series of experiments show the particular suitability of pertinent siliconized adhesive closure parts 23.

Test series 1:

Bonding of the samples 1 day after crosslinking of the silicone acrylates at a processing speed of 10 m / min. The adhesive closure member 23 with rubber-based adhesive means 25 was pressed by hand onto the siliconized adhesive closure 23 and was not further loaded.

Peel-1: adhesive closure member 23 with adhesive agent 25 deducted from siliconized adhesive closure member 23 and glued onto steel sheet.

Peel-2: peel test directly from siliconized adhesive closure part 23.

In the blank sample of the adhesive agent 25 are 2.9 to 3.2 atom% of silicon. Bonding / days Ford / ° C Peel-1 / N cm ^-1 Peel-2 / N cm ^-1 Si / atomic% 1 70; 70 11.5; 13.5 ≤1,2 7.0, 7.3 5 70; 70 11; 12 ≤ 1.3 6,6; 7 12 70; 70 11; 11.5 ≤ 0.5 4.6, 7.6

Series 2

Bonding of the samples 5 days after crosslinking of the silicone acrylates at a processing speed of 100 m / min. The adhesive closure member 23 with adhesive agent 25 was pressed by hand on the siliconized adhesive closure member 23 and loaded the bonded samples between two sheets of size 300 mm x 300 mm with about 5.5 kg. Bonding / days Ford / ° C Peel - 1 / N cm- ¹ Peel-2 / N cm ^-1 Si / atom% 1 70; 72 10.5; 11 ≤ 0.5 11.4; 11.4 7 60; 65 9; 8.5 a 14.2; 12.8 a: not measurable, because the separation force is too low.

Consequently, very high speeds of between 10 and 100 m / min can be achieved for the coating processes with good results.

If the siliconized adhesive elements of the adhesive closure part 23 are not yet fully cured, a small silicone transfer to the adhesive is possible, but this does not adversely affect the adhesive property. With the method according to the invention it is in any case possible to roll up the adhesive closure member 23 to transportable containers, so that the adhesive agent 25 is coverless in immediate contact with the underlying Verhakungsmitteln 27 and that nonetheless unproblematic for further processing, the pertinent adhesive closure member 23 can be handled by the bundle roll ,

In an amended, unspecified embodiment of the adhesive closure part according to the invention this may consist of a tissue, the interlocking means this time consist of individual loops, which are connected to the tissue. The fabric may be a textile material or made of plastic. Furthermore, the individual loops can be integrally connected to the fabric or be subsequently woven into this. The pertinent adhesive fastener part with loop elements is then likewise subjected to the process according to the invention and coated with a silicone material, wherein the material coated to the extent comprises the loops along their insides and also the Support material in the form of the fabric is now coated by the silicone material.

Cationic radiation curing is preferably used in the said embodiment, suitable starting monomers in particular being cycloaliphatic compounds which readily polymerize under ring opening, e.g. cycloaliphatic epoxides. Onium salts, which under UV influence form free Lewis or Bronsted acids, serve as photoinitiators. The advantage of cationic radiation curing is that, even after passing through the UV radiation source, post-curing of the silicone-containing separating layer takes place on the adhesive closure part with its loop elements.

Claims (9)

1. Method for producing an adhesive closure part (23) with a multitude of hook-up means (27) formed with a support (11) on one of its two sides, whereby an adhesive (25) is applied on the opposite side, and whereby a separating layer (29) containing silicone at least in part is applied on the side of the support (11) with the hook-up means (27), characterised in that the hook-up means (27) are formed from rods (17) with thickenings (19) at their ends, and in that the silicone separating layer (29) is applied thicker in the recesses of the individual hook-up heads forming the thickenings (19), and in that the rods (17) are kept substantially free from the silicone containing separating layer (29).
2. Method according to Claim 1, characterised in that silicone acrylates are used as separating layer (29), and in that curing of the separating layer (29) is carried out by means of radiation curing.
3. Method according to Claim 1 or 2, characterised in that a synthetic material is inserted into a gap between a pressure tool (3) and a forming tool (5) for producing the hook-up means (27), and in that these tools (3, 5) are driven in such a way that the support (11) is formed in the gap and conveyed in a transport direction, whereby a sieve containing continuous hollow spaces is used as the forming element on the forming tool (5), and whereby the hook-up means (27) are formed by curing the synthetic material in the hollow spaces of the sieve at least in part.
4. Method according to one of the Claims 1 to 3, characterised in that the silicone containing separating layer (29) is applied onto the synthetic material in

   - a gaseous or steam condition, or

   - a liquid, sludge, or paste condition, or

   - an ionised condition by means of electrolytic or chemical separation, or

   - a solid, especially grain or powder condition.
5. Method according to one of the Claims 1 to 4, characterised in that at least one UV radiation source (35) is used for the radiation curing of the separating layer (29).
6. Method according to one of the Claims 1 to 5, characterised in that a rubber based adhesive is used as the adhesive (25).
7. Method according to one of the Claims 1 to 6, characterised in that a thermoplastic adhesive is used as the synthetic material.
8. Method according to one of the Claims 1 to 7, characterised in that the adhesive closure part (23) is rolled up into transportable bindings, so that the adhesive (25) abuts directly against the underlying hook-up means (27).
9. Method according to one of the Claims 3 to 8, characterised in that speeds for the coating process are drive at between 10 and 100 m/min in the transport direction of the adhesive closure part (23).

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