DE60005314T2 - FASTENING MATERIAL WITH LOOP - Google Patents

Description

1. Technical area

The present invention relates to a loop fastener material or containing a loop material for attachment to a complementary warp fastener a loop layer as the first main page and a pressure sensitive adhesive layer as the second main page. In particular, the present invention relates such a loop fastener material, in which the loop layer contains a certain silicone release agent. The The invention further relates to a method for producing the loop fastener material as well as a loop closure material bandage. The loop closure material according to the invention is particularly suitable for use in the manufacture of absorbent bodies such as Diapers, the present invention accordingly a suction body with the loop closure material according to the invention concerns.

2. State of the technology

Loop material webs are well known, which can be cut into loop band parts by Velcro fasteners. such Loop webs typically include a backing and a variety in the vehicle anchored loops from lengthways oriented plastic fibers with the hook of the hook part of a Velcro fastener removable velcro capable from a surface of the carrier protrude, and are among many other possibilities also by conventional Weaving or knitting can be made. Loop material webs where the loops in the carrier sewn are described in U.S. Patents 4,609,581 and 4,770,917.

In the U.S. Patent 5,256,231 describe loop materials for attachment to a complementary warp fastener that are cheaper to manufacture than the loop materials mentioned above and also have good aesthetic properties. To produce the loop closure material according to this US patent, either a nonwoven web or a group of yarns arranged essentially in parallel are corrugated in a corrugating roller gap and then connected at certain anchorage points to a thermoplastic film extruded onto the web of the corrugated fiber material. To produce a particularly inexpensive and functional loop construction, fibers are used which have a titer of less than 25 denier and preferably of 1 to 10 denier, the basis weight of the loop material being 5 to 300 grams per square meter. This type of loop material is particularly suitable as a loop part of a Velcro fastener, in which only a limited number of closures and reclosures are to be expected, such as. B. in the case of an absorbent body, for example a diaper.

For use in manufacturing an absorbent body for single use, such as B. a diaper, comprises the loop fastener material usually a loop layer as the first main surface in succession (1), comprising (a) a plurality of Velcro flexible loops Fibers and (b) a support, in which the flexible loops are anchored, and (2) the second main area a layer of pressure sensitive adhesive. The loop closure material is usually offered as a set of a plurality of one another Of loop fastener material or as a roll of at least one layer wound on itself of the loop fastener material. To such associations contamination of the loop layer by the adhesive layer ruled out you can create a separating layer between the loop layer and the adhesive layer Arrange. However, this has the disadvantage that additional waste arises and such associations expensive.

Out EP 693889 a loop fastener material unit is known which comprises one or more multi-layer loop fastener material layers for the loop portion of a hook and loop fastener, the loop fastener material in the order given: (1) a loop layer on its first major surface, the loop layer comprising: (a) a plurality of flexible loops which are designed so that they can be brought into releasable engagement with the complementary hook part of the Velcro fastener, and (b) a carrier layer to which the loops are anchored; and (2) a layer of pressure sensitive adhesive on its second major surface. In the loop fastener material assemblies according to this European patent application, the adhesive layer of an overlying portion of the loop fastener material is in direct contact with the loop layer of an underlying portion of the loop fastener material, the loops of the underlying portion being adapted to remove the overlying portion of the loop fastener material perform in a manageable state. According to the teaching of the, the loops can be presented in an accessible state EP 693889 be necessary to limit the adhesion between loops and pressure sensitive adhesive layer. According to the teaching of the European application, the loop layer can be coated with a release agent. Release agents listed as examples include reaction silicones, epoxysilicones and radiation-curable polyorganosiloxane-polyurea block copolymers according to EP 250248 ,

This type of loop fastener material unit or association offers the advantage of a cheaper one Production with less scrap, however, it has been found particularly with loop closure materials with a loop layer of flexible loops with a small one Titers of, for example, 12 denier and smaller have been found to be desirable would be that To improve loop strength and fiber contamination of the Adhesive layer of the one above Loop fastener material to diminish.

From the U.S. Patent 4,696,854 a porous two-layer nonwoven substrate is known, which consists of an organic plastic layer and a layer of a hardened silicone resin. If the organic plastic layer is coated with a hydrophilic, natural or synthetic pressure sensitive adhesive, an adhesive tape that can be wound on itself is obtained. Furthermore, the U.S. Patent 4,871,611 non-woven adhesive tapes for medical applications. In this case, a radiation-curable polysiloxane resin composition is applied and cured to the nonwoven substrate by one-sided coating, without any appreciable penetration into the nonwoven carrier taking place. The coating compositions listed by way of example contain practically 100% polysiloxane resin. The preferred silicone resin according to the U.S. Patent 4,871,611 (meth) acrylated polydialkylsiloxanes such as the silicone acrylates RC-149, RC-300, RC-450 and RC 802 from the TEGO ^WZ product range, available from Goldschmidt AG.

WO 88/7931 relates to release lacquers which to from 1 to 30 wt .-% reaction silicone as a disperse phase in 99 to 70 wt .-% of a reaction resin exist. Regarding the reaction silicones listed as examples include polydimethylsiloxanes with an acrylic group, a mercapto group or an oxirane group. The reaction resin consists at least partially of reaction oligomers with functional groups reactive with the reaction silicone. With the release varnish, labels can be made on paper or plastic film, for example.

WO 95/23694 relates to a silicone release coating which at least partially consists of a mixture of two different classes of (meth) acrylated silicones. The reaction silicones listed by way of example include those from Goldschmidt Chemical Corp. Silicones available under the trade name TEGO ^WZ RC. TEGO ^WZ RC-726 is mentioned in particular as an example of a class of silicones which can be combined with RC 705, an example of the second class of silicones. The silicone release coating according to this application can optionally also be a reactive oligomer such as. B. contain an acrylated or (meth) acrylated polyhydroxy compound.

From WO 96/5962 are radiation-curable silicone release lacquers known, at least partially from a mixture of two different Classes of (meth) acrylated silicones and a mono (meth) acrylate certain formula. About silicones listed as examples counting RC-726 and RC 708, each available from Goldschmidt Chemical Corp. and SL 5030, available from GE Silicones. The release varnish you can also be reactive Oligomers such as acrylated or methacrylated polyhydroxy compounds enforce. The doctrine also shows that the Release varnish suitable for use on a wide variety of substrates, including on paper, vinyl, PVC films, polyester films, Polyolefin films, glass, steel, aluminum and nonwovens.

From the U.S. Patent 5,562,992 a radiation-curable silicone release lacquer is known which consists of 2 to 7% of a (meth) acrylated silicone resin and 90 to 98% of an acrylated or methacrylated organic polyhydroxy compound or polyamino compound. Examples of silicones listed include RC 450, RC 450N, RC 706, RC 707, R 710, RC 720 and RC 726, all of which are from Goldschmidt Chemical Corp. are available. The release coating should be suitable for use on a wide variety of substrates, including paper, vinyl, PVC films, polyester films, polyolefin films, glass, steel, aluminum and nonwovens.

3. Presentation the invention

Object of the present invention is a loop material for attachment to a complementary Velcro fastener comprising in succession: (1) a loop layer with (a) a variety of Velcro flexible Loops of fibers with a single titer of less than 15 den preferably at most 12 den, and (b) a carrier, in which the flexible loops are anchored, and (2) a layer of pressure sensitive adhesive, characterized in that the Loop layer comprises a silicone release that is a reaction product a curable Mass from (i) a polydialkylsiloxane with acrylate and / or methacrylate groups and (ii) a silicon-free organic compound having at least two responsive Contains groups from the series acrylate group and methacrylate group.

The present invention relates to also a loop fastener material dressing with at least one multilayer layer as described above Loop fastener material in which the loop fastener material is arranged so that the Adhesive layer of a loop closure material lying on top directly on the loop layer of an underlying loop fastener material rests.

The invention further relates to a method for producing a loop material provided with a silicone release compound, in which a loop material is attached to a complementary one Velcro fastener part comprising a loop layer with (a) a plurality of Velcro flexible loops made of fibers with a single denier of less than 15 den, preferably at most 12 den, and (b) a carrier, in which the flexible loops are anchored, provides the carrier provides a pressure sensitive adhesive layer, the loop layer is coated with a hardenable silicone release agent and the silicone release layer thus applied is cured with actinic radiation or thermally, the silicone release agent (i) a polydialkylsiloxane with acrylate and / or methacrylate groups and (ii) a silicon-free organic compound with at least two contains reactive groups from the series acrylate group and methacrylate group.

The invention also relates to a suction body with a loop fastener material as described above on the outside.

4. Detailed Description of the invention

The loop closure material according to the invention comprises typically in succession: (1) a loop layer as the first major surface of the Loop fastener material wherein the loop layer (a) a variety of Velcro flexible Loops of fibers with a single titer of less than 15 denier and (b) a carrier, in which the flexible loops are anchored, includes, and (2) a pressure sensitive adhesive layer as the second major surface of the loop fastener material.

In order to reduce the above-mentioned problems of fiber contamination of the adhesive layer of an overlying loop fastener material in a loop material assembly or in a loop fastener material unit and to improve the strength of the loops, the loop layer of the loop fastener material contains a special silicone release agent. The silicone release agent of the loop layer consists at least partially of the hardened reaction product of a polydialkylsiloxane with acrylate and / or methacrylate groups and a silicon-free organic compound with at least two reactive groups from the series of acrylate and methacrylate. Preferred polydialkylsiloxanes include those in which the ratio of the average number of siloxane units to the average number of acrylate or methacrylate groups is between 10 and 15. Polydimethylsiloxanes with a ratio of the average number of siloxane units to the average number of acrylate or methacrylate groups between 10 and 15 are particularly preferred for the use according to the invention. Polydialkylsiloxanes suitable for use according to the invention typically have a viscosity of 100 to 500 mPa · s. Examples of silicones which can be used according to the invention are commercially available and include TEGO ^WZ RC-902 and RC-715, both available from Goldschmidt Chemical Corp.

With the silicon-free organic It is a compound for reaction with the polydialkylsiloxane typically an acrylated or methacrylated polyhydroxy compound or an acrylated or methacrylated polyamino compound. The organic compound has at least two and more and preferably over at least three acrylate and / or methacrylate groups. The organic Compound should also preferably have a viscosity of at least 500 mPa · s 25 ° C, especially preferably of at least 800 mPa · s at 25 ° C and very particularly preferred of at least 1500 mPa · s at 25 ° C exhibit. For special examples of usable according to the invention count organic compounds Ditrimethylolpropane tetraacrylate, available from UCB Chemicals available in Belgium as E 140, E-80, an amine-modified polyester acrylate UCB Chemicals, as well as E 810, a polyester tetraacrylate available from UCB. Modified pentaerythritol triacrylate (viscosity about 500 mPa · s), available from the sartomer as SR-444, aliphatic diacrylate oligomer (viscosity about 1000 mPa.s) available at Sartomer as CN-132, ethoxylated bisphenol A dimethacrylate (Viscosity about 1100 mPa · s), available Sartomer as SR-348, bisphenol A derivative diacrylate oligomer (viscosity about 1400 mPa.s) available at UCB as E-150.

In the hardenable mass from which the hardened Product is manufactured, the weight ratio of polydialkylsiloxane to the organic compound expediently between 8:92 and 70:30, preferably between 10:90 and 60:40 and especially preferably between 10:90 and 45:55.

As the second main surface of the Loop fastener material a layer of pressure sensitive adhesive is provided. Use as a pressure sensitive adhesive in the adhesive layer of the adhesive tape, they are commonly used in tapes for diapers used pressure sensitive adhesive. The pressure sensitive adhesive should be a loop closure material one according to the procedure in the example section measured at a withdrawal angle of 90 ° peel strength of at least 3 N / 2.54 cm. With this under a deduction angle measured from 90 ° peel strength after contact of the adhesive layer with the silicone release compound of the loop layer achieved adhesive strength. That said, the tape should go on unwinding from a roll or after being lifted from a stack of Loop fastening materials a peel strength measured at a peel angle of 90 ° maintained at least 3 N / 2.54 cm. The pressure-sensitive adhesive layer according to the invention preferably exists at least in part of a rubber resin based Adhesive, the stickiness of which by adding a tackifying Resin is modified. The rubber resin preferably consists at least partially from an A-B-A block copolymer in which the A blocks of a styrene monomer and the B blocks derived from isoprene, butadiene or their hydrogenated variant.

Such adhesives are general known from U.S. Patents 3,419,585, 3,676,202, 3,723,170 and 3,787,531.

For the use of the invention Particularly preferred adhesive compositions are from US Pat. Nos. 5,019,071 and 5,300,057. The preferred adhesive composition is at least partly from a thermoplastic elastomer component and one Resin component and the thermoplastic elastomer component in essentially from about 50-90 Divide and preferably about 60-80 Split a linear or radial styrenoprene styrene A-B-A block copolymer and about 10-50 Divide and preferably about 20-40 Share a simple styrene soprene A-B block copolymer. there are derived in both the A-B-A and the A-B block copolymers the A blocks of styrene or styrene homologues and the B blocks of isoprene either alone or in conjunction with small proportions of other monomers.

As already indicated above, are in the A-B-A block copolymers preferably as A blocks (terminal blocks) styrene or styrene homologs and as B blocks (Medium-sized Blocks) Isoprene either alone or in combination with small portions other monomers copolymerized. The individual A blocks have preferably a number average molecular weight of at least about 7000 and preferably in the range of about 12000-30000 and make up together preferably about 10-35 % By weight of the block copolymer. The number average molecular weight of the B blocks is in the case of linear A-B-A block copolymers preferably in Range of about 45,000-180000 and that of the liner copolymer even preferably in the range of about 75,000-200,000. The number average Molecular weight of the radial A-B-A block copolymers is preferred in the range of about 125,000-400,000 and that of the corresponding B blocks preferably at about 95000-360000.

Suitable radial ABA polymers correspond, for example, to the type according to U.S. Patent 3,281,383 and obey the following general formula: (AB -) (n) X, where A is a thermoplastic block containing styrene or styrene homologues in copolymerized form, B is a conjugated diene such as butadiene or isoprene copolymerized elastomeric block and X is an organic or inorganic linking molecule, with a Functionality from 2-4 according to the U.S. Patent 3,281,383 or possibly with a higher functionality according to the article "New Rubber is Backed by Stars" in Chemical Week, June 11, 1975, page 35. "n" means a number corresponding to the functionality of X.

In the AB block copolymers containing copolymerized styrene and isoprene, the number-average molecular weight of the individual A blocks is typically around 7000-20000, the total molecular weight of the block copolymer generally not exceeding 150,000. AB block copolymers based on styrene and isoprene are generally used in the U.S. Patent 3,787,531 described.

The elastomeric component of the preferred Adhesive may contain small amounts of other, more conventional elastomers, however, these should not exceed about 25% by weight of the elastomer Identify component. These include Natural rubbers, synthetic rubbers based on butadiene, isoprene, Butadiene styrene, butadiene acrylonitrile and the like, butyl rubbers and other elastomers.

The preferred adhesive mass contains per hundred Parts by weight of the thermoplastic elastomer component about 20-300 parts and preferably 50-150 Parts of the resin component. The resin component essentially consists from tackifying resins for the elastomeric component. In general, you can do all compatible usual use tackifying resins or mixtures thereof. These include hydrocarbon resins, Rosin and rosin derivatives, polyterpenes and other tackifiers.

The adhesive layer can also be used still small amounts of various other substances such as antioxidants, Heat stabilizers and UV absorbers, fillers and the like. Typical antioxidants are 2,5-di-tert-amylhydroquinone and di-tert-butyl cresol. You can also use conventional heat protection agents such as zinc salts of alkyldithiocarbamates. Likewise, the particulate mixture according to the invention fillers and pigments such as zinc oxide, aluminum hydrate, clay, calcium carbonate, Titanium dioxide, carbon black and add others in small amounts.

The adhesive layer is typically with a thickness of 20 to 200 μm and particularly preferably with a thickness of 25 μm to 100 μm.

The loop layer of the loop closure material according to the invention comprises a loop layer removable intervened capable, upright loops, which you can make after several known processes such as weaving, knitting, warp knitting, knitting with weft entry, Sew or Process for the production of nonwoven structures can proceed. there comprises the loop fastener material typically a backing layer with a variety of loops protruding from it. To representative Examples of Loop closure materials that can be used according to the invention counting Knitted fabrics such as warp knitted fabrics, knitted fabrics with weft insertion, knitted fabrics and circular knitted fabrics or knitted goods, sewn Materials and nonwovens.

The loop layer according to the invention is preferably connected to a thermoplastic film as a carrier by extrusion. To produce such a loop fastener material, a loop fastener material is produced using the method according to FIG U.S. Patent 5,256,231 provided, the loop layer coated with the curable silicone release agent and the silicone release coating thermally or actively niche hardened.

According to the procedure for providing the loop fastener material according to the U.S. Patent 5,256,231 a nonwoven web of fibers is provided, from which a fibrous web is formed with arcuate parts which project in the same direction from a surface defined by spaced-apart anchoring parts of the fibrous web, a thin layer of a melted thermoplastic material is extruded onto the spaced-apart anchoring parts of the fibers and thereby around them spaced anchoring parts of the fibrous web formed around at least part of a carrier, the arcuate parts of the fibrous web protruding from a front of the carrier, the layer of thermoplastic material cooled and solidified, whereby the web of loop material is obtained.

To form the fibrous web with arcuate parts the first and second are essentially cylindrical, undulating Links provided, each having an axis and several spaced apart ribs containing the periphery of the Define corrugated link, the ribs having outer surfaces and spaces between each other limit the parts of the ribs of the other wavy link meshing record, with the fiber web in between, the undulating links axially parallel to the parts of the ribs in a meshing Relationship arranged, at least one of the wavy links rotated between the combing Divide the ribs into the fibrous web so that the fibrous web essentially abuts the periphery of the first corrugating member and the arcuate Parts of the fibers in the rooms between the ribs of the first wavy link and the Anchoring parts of the fibrous web along the outer surfaces of the ribs of the first corrugated member forms, and the molded fiber web for a predetermined Distance behind the combing Split the ribs on the periphery of the first wavy Limbs held.

The procedure described above manufactured loop fastener material contains a carrier with a thermoplastic backing with an essentially uniform morphology and a trajectory from elongated aligned fibers with essentially undeformed anchoring parts, glued or fused in the thermoplastic carrier layer at spaced-apart traps, and between traps from a front of the carrier protruding arcuate Divide.

Are made from the loop material web Loop parts for closures manufactured that have a limited lifespan should have d. H. normally open at most 10 times and close again leave, so the arcuate Portions of the fibrous web preferably have a height above the carrier of less than about 0.64 Centimeters (0.250 inches), and preferably less than about 0.38 centimeters (0.15 inch); the distance between the detention points should be preferred are between about 0.005 and 0.075 inches and the width of the arcuate parts the fibrous web is between about 0.06 and 0.35 inches. In addition, should those in the arcuate Parts contained fibers preferably about the same height above Front of the carrier stand out, the height at least a third and preferably half to one and a half times is so big like the distance between the traps, with the fibers one Individual titer of less than 15 denier and at most 12 denier and together preferably a basis weight in the range of 5 to 300 grams per square meter and preferably in Range from 15 to 100 grams per square meter, the Measurement is made along the front of the carrier, so that between the fibers along the arc Share one enough size free space lies, d. H. a free area between about 10 to 70 percent so that the fibers run along the arcuate Let parts hook and loop easily through the hook part of the lock.

As fibers for the loop layer of the Loop fastener material many polymeric materials can be considered, including polypropylene, Polyethylene, polyester, nylon or polyamide or a combination such materials as a polyester core and a jacket made of polypropylene. In the same fiber web from which the loop layer can be formed Fibers from one material or fibers from different materials or combinations of materials are used.

As by extrusion with the loop layer connected carrier layer is the type that solidifies when cooling, or can is the type known as reaction hot melt adhesive, the cooling down partly solidify and then under the influence of an external element such as air humidity or actinic radiation. The carrier layer can, for example made of polypropylene or polyethylene. The backing layer can also be used with other carrier layers to a multi-layer carrier be connected.

For the production of the loop closure material according to the invention the loop layer of the closure material with the curable Silicone release coating. The silicone release agent can be applied by all methods known in coating technology. For special examples of suitable coating techniques include rolling, brushing, spraying, reverse rolling, Engraving and nozzle coating. According to a particularly preferred embodiment of the present Invention chooses one as a silicone release agent is essentially solvent-free and adds it the multi-roll process. It is essentially solvent-free to understand that the Coating composition less than 10 wt .-% and preferably less than 5% by weight of solvents contains.

The silicone release composition is typically applied in such an amount that one Dry application between 1 g / m ² and 3 g / m ² receives. An amount is preferably applied such that the amount of the cured silicone release composition measured by the method according to the examples is between 0.3 g / m ² and 2 g / m ² and preferably between 0.5 g / m ² and 1.5 g / m ² lies.

The hardening of the applied silicone release compound can by heat or photochemically by irradiation with actinic radiation such as z. B. electron beams, UV light, X-rays, gamma rays and Beta rays occur. According to a preferred embodiment of the present invention the silicone release compound also works thermally or photochemically Radical initiator. Examples of suitable photochemically working radical initiators, d. H. Photoinitiators in combination with ultraviolet light Can find application counting z. B. benzyl ketals, benzoin ethers, acetophenone derivatives, ketoxime ethers, Benzophenone, benzo- or Thioxanthones, etc. Specific examples of photoinitiators include: 2,2-diethoxyacetophenone, 2- or 3- or 4-bromoacetophenone, benzoin, benzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, benzophenone, 1-chloranthroquinone, p-diacetylbenzene, 9,10-dibromoanthracene, 1,3-dephenyl-2-propanone, 1,4-naphthylphenyl ketone, 2,3-pentendione, propiophenone, chlorothioxanthone, xanthone, fluorenone and their mixtures. An example of a commercially available Photoinitiator of this type is from Ciba Geigy Corporation in Hawthorne, New York, USA, available under the trade name Darocur 1173. An alternative as a photoinitiator is one from Lamberti spa available in Albizzate, Italy, under the name ESACURE KIP 100 Mixture of 70% oligo-2-hydroxy-2-methyl-1-4- (1-methylvinyl) phenyl-propanone and 30% 2-hydroxy-2-methyl-1-phenyl-1-propanone.

If necessary, the radical initiator typically in an amount of 1 to 10 parts by weight per 100 Parts by weight of the silicone release composition and preferably in an amount from 2 to 5 parts by weight per 100 parts by weight of the silicone release composition used.

To stabilize against premature The radiation-curable compositions according to the invention can be polymerized during storage Silicone release agents an addition of conventional polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, phenothiazine, di-t-butylparacresol etc. included. As a rule, amounts of stabilizers are already effective of 0.1 percent by weight and less.

On the side with the loop layer opposite Side of the loop fastener material the pressure-sensitive adhesive layer is now applied. Applying the layer of pressure sensitive adhesive can by all known coating methods or by initial Apply the adhesive layer to a release liner and then transfer lamination respectively. Suitable coating techniques include hot melt coating techniques and techniques based on solvents or water like squeegees, nozzle coating, spraying, Curtain coating and flat bed coating.

The loop closure material according to the invention will be convenient provided as an association in which at least one layer of the Loop fastener material is arranged so that the Adhesive layer of a loop closure material lying on top directly on the loop layer of an underlying loop fastener material rests. Such a dressing contains, for example, a stack stacked layers of the loop fastener material. However, the loop material bandage can also be one Roll at least one self-wound layer of the loop fastener material act.

The loop closure material according to the invention can always be used when a loop component a Velcro fastener is to be connected to a substrate. In particular let yourself the Velcro material on the outside a single-use absorbent such as a disposable diaper muster. The loop closure material can be used in many different ways Way on a diaper and can be applied on a single Diaper perform at least one of several functions.

The loop closure material is often applied to the diaper part referred to as the central waist region on the front of a disposable diaper. The use as a so-called front belt is for example in the U.S. Patent 5,053,028 by Zoia et al. in 1 shown.

The loop closure material according to the invention let yourself also as a component of the attached to the wing parts of the diaper The diaper fastening system insert and install in laminates. So you can, for example Loop fastener material as part of a three-band mechanical fastener laminate according to the British Patent application GB 2 257 895 and 3M on November 10, 1998 submitted European Use patent application 98 121 337.4, with the front belt detaches from the laminate the first time and permanently on the front area the diaper sticks.

Furthermore, the loop fastener material can be incorporated into a fastener laminate in order to ensure adherence to the diaper wing according to the European patent application EP 795,307 to avoid opening or flagging the folded laminate. The loop fastener material can also be incorporated into a fastener laminate to seal the soiled diaper in accordance with European patent application 529 681 and European patent application EP 321 324 to make disposable.

In the following examples the invention closer explains without limiting it to that.

Examples

Test Methods

Determination of the release mass on the surface a loop layer

The on the surface of the Loop layer present amount of release liner was determined using the X-ray fluorescence analyzer Model 200TL from ASOMA Instruments in Austin, Texas. The available from Th. Goldschmidt AG in Essen, Germany test methods consists of two parts: a calibration technique under the name KM RC 005 A and a measuring technique under the designation SM 316 A.

When it comes to calibration technology first known amounts of UV curable Polydimethylsiloxane (PDMS) (available from Th. Goldschmidt as TEGO-RC 726) applied on a polyester film and hardened. there were at least five different application quantities applied, UV hardened and on X-ray fluorescence measured. Subsequently became one the X-ray fluorescence calibration curve related to the amount of PDMS.

The measuring technique uses X-ray fluorescence of silicon atoms. This will result in an unknown amount of silicone on its surface having test substrate exposed to X-ray fluorescence. The absolute value of fluorescence is measured and on the calibration curve read the corresponding amount of PDMS.

The actual amount of release material present on the surface is calculated from the amount of the PDMS measured using the following formula: Release mass on surface in g / m 2 = g PDMS / m measured on the coated substrate 2 - g PDMS / m measured on the uncoated substrate 2 about factor for the release compound

• 1. Auf dem beschichteten Substrat gemessene g PDMS/m² werden von der Kalibrationskurve, die die Fluoreszenzmenge zur vorliegenden Menge PDMS in Relation setzt, abgelesen
• 2. Bei g PDMS/m² auf unbeschichtetem Substrat handelt es sich um den für das Schlaufenverschlußmaterial ohne Trennmasse gemessenen Wert, entsprechend einer „Blindmessung".
• 3. Ein von der Th. Goldschmidt in der Testmethode eingegebener Faktor, eine „RC-Zahl", für jeden der UV-härtbaren (meth)acrylierten Silicone. Dabei handelt es sich im wesentlichen um den Anteil des UV-härtbaren Silicons an PDMS. Der Faktor liegt stets unter 1,0 und nimmt mit abnehmendem Silicongehalt und zunehmendem Gehalt an Acrylatgruppen der W-härtbaren Silicone ab. Für die Trennmasse errechnet sich der Faktor aus Menge und Faktor der jeweils eingesetzten Materialien durch Gewichtsmittlung. Keine Polydimethylsiloxaneinheiten enthaltende und somit silicumatomfreien Additiven wird der Faktor null zugeordnet.

The elements to be used in the formula are determined as follows:

• 1. g PDMS / m ² measured on the coated substrate are read from the calibration curve which relates the amount of fluorescence to the amount of PDMS present
• 2. g PDMS / m ² on uncoated substrate is the value measured for the loop closure material without a release compound, corresponding to a "blind measurement".
• 3. A factor entered by Th. Goldschmidt in the test method, an “RC number”, for each of the UV-curable (meth) acrylated silicones. This is essentially the proportion of the UV-curable silicone in PDMS. The factor is always less than 1.0 and decreases with decreasing silicone content and increasing content of acrylate groups of the W-curable silicones. For the separating mass, the factor is calculated from the amount and factor of the materials used in each case by weight averaging the factor zero is assigned.

Separation at a trigger angle of 90 ° (modified Keil test)

This test is about a method of measuring for the removal of an adhesive tape from a release lacquered surface required Force.

A first, 5 cm wide and 10 cm long sample of the loop fastener material was placed on a steel base glued on by sticking the adhesive surface and using twice rolled over a 2 kg roller has been.

Then on the first sample one second sample of loop closure material with a width of 5 cm and a length of 10 cm so that the Adhesive layer of the second sample on the release coating of the first sample rested. The laminate formed from the samples was washed twice with a Rolled over 2 kg roller.

The laminate was then in a 50 ° C be called Convection oven introduced, weighted with a weight of 1400 g and at 50 ° C for 3 days heated.

The test laminate was then placed in the oven removed and for 24 hours at 23 ° C and a humidity of Rested 50% before testing.

According to the peel strength test described above at a withdrawal angle of 90 ° the adhesive of the second sample from the loop layer of the first Sample with a peeling speed peeled off at 300 mm / min.

The materials were changed three times each assessed and the results averaged. The results are in N / 50 mm specified.

Peel strength at a peel angle of 90 °

To determine the peel strength was a part of the loop fastener material from a roll of loop fastener material produced in the examples settled. The loop fastener material sample was first tested Modified wedge test described above. After deducting the top loop fastener material from the lower strip in the wedge test at an angle of It became 90 ° top loop closure material immediately glued to the polyethylene test surface described below. With the test, the adhesiveness of the loop fastener material on a polyethylene film after contact with the silicone-based Release material assessed under heat and pressure.

The polyethylene film used in this test was produced as follows. A low density polyethylene resin (Tenite 1550P, available from Eastman Chemical Co. of Kingsport, Tennessee) with a melt index of 3.5 grams / 10 minutes and a density of 0.918 grams / cm ³ was over at a melt temperature of 182 ° C formed a conventional extrusion die with a hanger-shaped slot vertically downward. The melt emerging from the die was drawn into a nip formed by a mirror chromed roll (8 ° C water inlet temperature) and a silicone rubber roll (7 ° C water inlet temperature) and pulled out into a 330 micron film. The film side in contact with the chromed roller was used for test purposes. The film side used for the determination of the peel strength had an average roughness value of the surface R _a of 1.4 μm and an average roughness depth R _z of 12.5 μm. The roughness values R _a and R _{z were determined} with the laser profilometer from UBM Messtechnik GmbH in Ettlingen, model no. UB-16. The roughness values were calculated using this machine in accordance with the German Industrial Standard (DIN) 4768 and DIN 4762.

For the production of the test substrate the polyethylene film was firmly connected to the stainless steel test plate surface. The polyethylene film was covered with double-sided adhesive tape (available as Tape 410 from 3M Company) glued to the test plate.

To determine the peel strength was at a withdrawal angle of 90 ° a tensile test device in particular rebuilt to maintain a peel angle of 90 ° at the Enable test. The experimental setup corresponds to FINAT TEST METHOD NO. 2, a common peel strength test method at a trigger angle of 90 ° (available from International association of manufacturers and processors self-adhesive Products (FINAT)).

• 1) der nach FINAT 2 vorgeschriebene Untergrund aus Glas wurde durch eine Polyethylenfolie ersetzt
• 2) statt einer „standardmäßigen FINAT-Testwalze" wurde eine 2 kg schwere Walze angewendet
• 3) statt dem zweimaligen Abrollen mit 200 mm/min gemäß der FINAT-Methode wurde die Probe jeweils einmal in jeder Richtung mit 300 mm/min abgerollt
• 4) statt der 20 min bzw. 24 Stunden gemäß der FINAT-Methode betrug die angewandte Verweilzeit im wesentlichen null.

There were several deviations from the FINAT method described above as follows:

• 1) The glass substrate specified in FINAT 2 was replaced by a polyethylene film
• 2) Instead of a "standard FINAT test roller", a 2 kg roller was used
• 3) Instead of unrolling twice at 200 mm / min according to the FINAT method, the sample was unrolled once in each direction at 300 mm / min
• 4) Instead of the 20 min or 24 hours according to the FINAT method, the dwell time used was essentially zero.

On the polyethylene surface of the Test plate, d. H. the one with the chromed roller in the manufacture in Contacted film side, became a 30 cm long and 2.54 cm wide loop closure material sample fastened by unrolling twice with a 2 kg roller. Part of the loop fastener material was touched in released the test device described in the test method. To the loop fastener material became a dwell time of less than one minute at a speed of 300 mm / min from the polyethylene substrate peeled.

The 90 ° peel strength was in units of N / 2.54 cm. Three samples were assessed and the results averaged.

In the examples used material

(Meth) acrylate silicones

RC-715 means an acrylate functionalized Polydimethylsiloxane with a functionality of 26: 2 (13.0), available from Goldschmidt AG in Essen as TEGO RC-715.

RC-902 means an acrylate functionalized Polydimethylsiloxane with a functionality of 56: 4 (14.0), available from Goldschmidt AG in Essen as TEGO RC-902.

The quotient is off under "functionality" the number of dimethylsiloxane units and the number of (meth) acrylate groups to understand.

organic links

• E140 Ditrimethylolpropane tetraacrylate (DMPTA), M _W = 438, viscosity = 1100 mPa · s, available from UCB Chemicals in the Belgian drug store as E 140.
• E80 amine modified polyester acrylate, viscosity = 3000 mPa.s, available from UCB Chemicals in the German drug store.

UV polymerization initiator

• DAROCUR 1173 2-Hydroxy-2-methyl-1-phenylpropan-1-one, UV photoinitiator the Ciba-Geigy in Basel, Switzerland.

example 1

A loop fastener material was made from a loop material with an extrusion-bonded loop layer, available from 3M Company of St. Paul, Minnesota, USA, as XML 6157. The loop portion of the carrier was 380 microns thick. The polypropylene film part of the carrier had a weight of 40 g / m ² . The fibers of the loop layer consisted at least in part of polypropylene staple fibers with a diameter of approximately 37 microns or approximately 9 deniers.

A mixture of 30% by weight UV-curable silicone (available as TEGO ^WZ RC-902 from Th. Goldschmidt AG in Essen), 70% by weight ditrimethylolpropane tetraacrylate (DMPTA, M _W = 438, viscosity = 1100 mPa · s , available as E140 from UCB Chemicals) and 3% by weight UV polymerization initiator (available as DAROCUR ^WZ 1173 from Ciba-Geigy in Basel, Switzerland) was used with a motorized propeller mixer at a temperature of 23 ° C for 10 min mixed to a homogeneous, milky white suspension. The suspension was then applied to the loop layer of the carrier in a quantity of 2.5 g / m ² using a multi-roller coater. To determine the application, the support was weighed before and after coating with the release agent and the difference was determined.

The paint was then in an inert atmosphere (Nitrogen) with UV light by passing through the coated loop fastener material under medium pressure mercury lamps with 120 W / cm (available as MODEL F-450 from Fusion UV Systems, Inc., Gaithersberg, Maryland) networked. The distance of the lamp from the surface was Loop layer 2.5 cm.

A single layer of pressure sensitive adhesive was then applied to the side of the loop closure material opposite the loop layer. The adhesive was based on a blend of synthetic block copolymer and tackifying resin and was applied in an amount of 33 g / m ² by conventional hot melt coating techniques using a drop nozzle.

The loop fastener material thus produced was wound up into a roll and then cut into thinner, 5 mm wide rolls. The components used to make the loop fastener material are summarized in Table 1.

Parts of the roll so produced was handled and subjected to a modified wedge test. The adhesion to a sample from the wedge test was then determined Standard polyethylene surface according to the above Test methods measured.

The test results of the loop fastener material are summarized in Table 2.

Examples 2

The procedure was analogous to Example 1 except that a other type of organic compound was used. In example 2 70 parts of E80, an amine-modified polyester acrylate, viscosity approx. 3000 mPas (available as E80 from UCB Chemicals in the German drug store) as organic Connection used in addition to 30 parts of RC-902 according to Example 1.

For the production of a loop fastener material was initially the release compound is applied to the loop side according to Example 1 and networked and then according to example 1 of the pressure sensitive adhesive on the opposite Side applied.

Example 3

The procedure was analogous to Example 1 except that instead RC-902 from Example 1 RC-715 as that contained in the release compound UV-curable Silicon was used.

Comparative Example 1

The procedure was analogous to Example 1, except that a polyorganosiloxane-polyurea block polymer according to European Patent Application No. 250.248 (Leir et al.) Was used as the silicone release composition on the loop layer. The coating was carried out according to the gravure coating process and yielded drying a dry application of 0.5 g / m ² .

Analogous to Example 1, a loop fastener material was used made by the opposite of the loop layer Side a pressure sensitive adhesive was applied. The loop closure material was then wound up into a roll and tested.

The test results are in table 2 listed. The one measured for separating the pressure sensitive adhesive from the release coating Force was 23.1 N / 50 mm, an unacceptably high release value Rolling are difficult to unwind and damage the loop surface to lead could.

Table 1

Table 2

Claims (11)

Loop material for attachment to a complementary Velcro fastener, comprising the following: (1) a loop layer with (a) a plurality of Velcro flexible loops made of fibers with an individual titer of less than 15 den and (b) a carrier in which the flexible loops are anchored and (2) a pressure-sensitive adhesive layer applied to the carrier, characterized in that the loop layer comprises a silicone release composition which is a reaction product of a curable composition composed of (i) a polydialkylsiloxane with acrylate and / or methacrylate groups and (ii) a silicon-free organic compound contains at least two reactive groups from the series acrylate group and methacrylate group. Loop material according to claim 1, wherein one with actinic radiation curable Mass is included. Loop material according to claim 1, in which a polydialkylsiloxane is contained in which the ratio the average number of siloxane units to the average number of acrylate and methacrylate groups is between 10 and 15. Loop material according to claim 1, wherein the organic Compound a viscosity of at least 500 mPa · s at 25 ° C having. Loop material according to claim 1, wherein the polydialkylsiloxane and organic compound in the curable composition in a weight ratio to each other between 8:92 and 70:30 are included. Loop material according to claim 1, wherein the loop layer with a thermoplastic film as a carrier Extrusion is connected. At least one multi-layer layer of loop material according to one of claims 1 to 6 comprehensive loop material association, in which the loop material is arranged so that the Adhesive layer of a loop material lying on top immediately on the loop layer of an underlying loop material rests. Loop material dressing according to claim 7, wherein it a role of at least one wound on itself Position of the loop material is. Process for the production of a silicone release agent provided loop material, in which one a loop material for attachment to a complementary Velcro fastener, comprising a loop layer with (a) a variety of Velcro flexible Loops made of fibers with a single titer of less than 15 den and (b) a carrier, in which the flexible loops are anchored, provides the carrier with provides a layer of pressure sensitive adhesive, the layer of loops with a curable Silicone release coating and the silicone release layer so applied with actinic radiation or thermally cured, the silicone release agent (i) a polydialkylsiloxane with acrylate and / or methacrylate groups and (ii) a silicon free organic compound having at least two responsive Contains groups from the series acrylate group and methacrylate group. suction body with one on its outside adhesive loop material according to a of claims 1 to 6. Loop material adhering to a substrate according to a of claims 1 to 6.