MXPA01005040A - Non-woven adhesive tape for the manufacturing of a diaper closure system - Google Patents

Abstract

The present invention provides an adhesive tape comprising a backing comprising a fibrous layer of woven fibers or of non-woven fibers of a thermoplastic polymer, said backing comprising on said fibrous layer a silicone release layer and the side of the backing opposite to the side comprising said silicone release layer comprises a pressure sensitive adhesive layer, said silicone release layer comprising a cured reaction product of a curable composition comprising (i) a polydialkylsiloxane having acrylate and/or methacrylate groups and (ii) an organic compound free of silicon and comprising at least two reactive groups selected from the group consisting of an acrylate and a methacrylate group, said adhesive tape having a 90°peel adhesion of at least 6 N/2. 54 cm relative to a polyethylene film surface and said adhesive tape having a Keil test value of not more than 1 N/2.54 cm. The adhesive tape is suitable for making cloth-like closure systems for absorbent articles such as diapers.

Description

TISSUE ADHESIVE TAPE FOR THE MANUFACTURE OF A CLOSURE SYSTEM FOR DIAPERS Field of the Invention. The present invention relates to an adhesive tape comprising a backing which comprises a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer and which can be used in the manufacture of absorbent articles, such as diapers, to provide a tongue with mechanical seal for the absorbent article. In particular, the present invention relates to a silicone release liner that can be provided on the fibrous layer of the backing, in order to provide easy winding of the adhesive tape from a reel.

Additionally, the invention relates to a pre-laminated composite tape and an absorbent article, which comprises the adhesive tape of the invention. Background of the Invention Generally, a disposable diaper has a thin, flexible, extensible back cover film of low density polyethylene, an absorbent core on the inside of the back cover film REF: 129152 and a porous top sheet covering the core. Such diaper is located in the crotch of the user, with the ends of the honeycomb extended, respectively, towards the front and back. Then, the adjacent edges of the diaper on each side are placed either adjacent to one another or superimposed, adhering a strip of pressure-sensitive adhesive tape or a mechanical adjustment tape to the backsheet, on the edge adjacent to each of them. the two edges, keeping the diaper closed. An attractive closure system that is used for disposable articles employs a mechanical fastener comprising, for example, the components of a burr-like fastener. The mechanical fastening systems have the advantage of being able to be used repeatedly to open and reattach the disposable article. The closure systems containing the mechanical fasteners are described in United States patents US 5,019,073 and US 5,176,671 and in the applications of European patents EP 324,578, EP 563,457 and EP 563,458.

Generally, a closure system employing a mechanical fastener to the back cover film on both edges of the disposable diaper. To date, an adhesive tape having a polymeric film backing has been used to secure the mechanical fastener to the edges of the diaper. However, it would be advantageous to replace the back reinforcement of plastic film with a non-woven back reinforcement that causes a feel similar to that of the fabric. The latter is particularly convenient, since many other parts of the diaper-and in particular, the outer surface of the diaper-offer a feel similar to that of the fabric. Since the adhesive tape used to manufacture the closure system is typically provided in the form of a reel, where the tape is wound on itself, it is necessary to provide a coating to facilitate detachment from the side of the posterior reinforcement which is the opposite to the side that contains the adhesive layer of the tape. However, the adhesive layers used to bond the polyethylene surface of a diaper generally include an aggressive adhesive, for example, one with a bond strength at 90 ° greater than 6 N / 2.54 cm. Although the coatings to facilitate detachment for the non-woven back reinforcements in the art, none of them was entirely satisfactory for use with an adhesive tape employing an aggressive adhesive, such as is normally used in the production of closure systems for diapers The problems that arise with the coatings to facilitate detachment in the prior art include: the transfer of the coating to facilitate detachment to the adhesive layer, whereby the adhesive performance thereof is affected.; the difficulty to unroll them and the damage caused to the subsequent non-woven reinforcement of the tape, during unwinding. The application of the mechanical seals using the adhesive tape can be carried out through a lamination in the line of all the fastening and detachment components in the manufacturing line of the diapers. However, on-line lamination complicates the manufacturing process of the desired products and sometimes causes a problem for manufacturers.

Accordingly, fastening devices of closure systems that are provided in the form of a reel were developed. A simple reel of closure tape in the form of a pre-laminate contains all the necessary elements, directly in the manufacturing line. The closure tape is applied to the diaper as a composite tape, where the width of the spool has substantially the same desired length of the closure of the diaper to be manufactured. The closure tape is cut at right angles to the edges of the composite tape spool, with intervals corresponding to the width of the desired closure tape and adhered in an appropriate location along the edge of one side of the diaper . Since also in the case of such a closure tape in the form of an impelled pre-face, the adhesive layer comes into contact with the other side of the back reinforcement when the tape is rolled up, there are also here the same problems that were mentioned for the adhesive tape - in the form of a reel. US 4,696,854 discloses a porous, double-layer nonwoven substrate, which consists of an organic polymer layer and a cured silicone resin layer. An adhesive tape capable of rolling on itself can be produced by coating a pressure sensitive adhesive, synthetic or natural, hydrophilic, on the organic polymer layer. It is further disclosed that such adhesive tapes are useful as medical types, because the double layer nonwoven substrate has approximately the same porosity as the nonwoven without the cured silicone resin layer. Since the adhesive tapes are directed to a medical application, the preferred adhesive used is a pressure sensitive polyacrylic adhesive, which are very non-aggressive adhesives that allow the tape to be detached from the skin without causing pain. US 4,871,611 is similarly related to non-woven adhesive tapes proposed for medical applications. This U.S. patent discloses the coating of the non-woven substrate on one side, with the radiation curable polysiloxane resin composition and curing of the composition, while preventing substantial penetration into the subsequent non-woven reinforcement. The exemplified coating compositions contain essentially 100% polysiloxane resin. The preferred silicone resin of US 4,871,611 includes polydialkylsiloxane (meth) acrylates such as the TEGO ™ Silicone Acrylates RC-149, RC-300, RC-450 and RC-802 marketed through Goldschmidt AG. WO 88/7931 relates to the release coatings comprising between 1 and 30% by weight of a reactive silicone, dispersed as a discontinuous phase, by 99 to 70% by weight of a reactive resin. The reactive silicones of the examples include the polydimet il-si loxanes having an acrylic group, a mercapto group or an oxirane group. The reactive resin comprises reactive oligomers having functional groups capable of reacting with the reactive silicone. The release liner can be provided on paper or a polymeric film to produce, for example, labels. WO 95 / 23,649 relates to a coating for facilitating the release of silicone, comprising a mixture of two different classes of silicones (meth) acrylates. The reactive silicones of the examples include the available silicones "in place" through Goldschmidt Chemical Corp., under the tradename TEGO ™ RC, TEGO ™ RC-726 is particularly disclosed as an example of a class of silicones to combine with the RC-705, an example of the second class of silicones The coating for facilitating the release of silicone from this application may optionally also contain a reactive oligomer such as, for example, a polyhydroxy acrylated or methacrylated compound. 5,962 reveals coatings to facilitate the release of silicone, radiation curable comprising a mixture of two different classes of (meth) acrylate silicones and a mono (meth) acrylate with a specific formula. The silicones of the examples include RC-726 and RC 708, both commercially available through Goldschmidt Chemical Corp. and SL 5,030, marketed through GE silicones. Reactive oligomers such as polyhydroxy acrylated or methacrylated compounds can also be added to the composition to facilitate detachment. It is also explained that the coating to facilitate peeling can be used on various substrates, which include paper, vinyl, PVC films, polyester films, polyolefin films, glass, steel, aluminum and fabrics. nonwoven US 5,562,992 discloses a composition for facilitating the release of silicone, curable by radiation, comprising between 2 and 7% of a silicone resin (meth) acrylate and between 90 and 98% of a polyhydroxy organic methacrylated compound or acrylated or a polyamino compound. The silicones of the examples include RC 450, RC 450N, RC 706, RC 707, RC 710, RC 720 and RC 726, all marketed through Goldschmidt Chemical Corp. The coating to facilitate detachment is said to be useful over various substrates including paper, vinyl, PVC films, polyester films, polyolefin films, glass, steel, aluminum and non-woven fabrics. EP 693,889 discloses a curl fastening material, which includes crimps that will engage such that they can be peeled off to the complementary portions of a fastener, where the curl fastening material is provided as a spool or as a pile. To control the adhesion between the curls of the curl layer and the adhesive layer when they are stored in the form of a reel or stacked, it is explained that the curls are covered with a release agent, such as a reactive silicone. Brief Description of the Invention The present invention provides an adhesive tape comprising a back reinforcement, which includes a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer.; said back reinforcement comprises on said fibrous layer, a silicone release layer and the side of the back reinforcement opposite the side comprising said silicone release layer, comprises a pressure-sensitive adhesive layer; said silicone release layer comprises a cured reaction product of a curable composition, comprising: (i) a polyalkyl 1-si loxane having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising minus two reactive groups, selected from the group consisting of an acrylate group and a methacrylate; said adhesive tape having a bond strength at 90 °, of at least 6 N / 2.54 cm, relative to a film surface and said adhesive tape has a Keil test value of not more than 1 N / 2.54 cm. The adhesive tape of the present invention provides the advantage of easily unrolling, without damaging the backing material, even after storage of a reel of the adhesive tape. Moreover, the adhesive properties required of the adhesive tape are maintained. Accordingly, the adhesive tape is suitable for use in the manufacture of closure systems for absorbent articles, in particular diapers. For such use, the adhesive tape provides the particular advantage of giving the closure system a tactile feel similar to the fabric. The present invention also provides an absorbent article comprising an adhesive closure tape attached to a portion of the edge; the adhesive closure tape comprises a backing which includes a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer; said back reinforcement comprises on said fibrous layer, a silicone release layer and the side of the back reinforcement opposite the side comprising said silicone release layer, comprises a pressure-sensitive adhesive layer; said silicone release layer comprises a cured reaction product of a curable composition, which includes (i) a polyalkyl siloxane having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from the group consisting of an acrylate and a methacrylate group, said adhesive closure tape has an out-of-round adhesion of at least 6 N / 2.54 cm, with respect to a polyethylene film surface and a value of From the Keil test not exceeding 1 N / 2.54 cm, a first section of the adhesive closure tape is adhered to the edge portion of the absorbent article, by said pressure-sensitive adhesive layer and a second section of the tape. of adhesive closure has a mechanical fastener placed on the pressure sensitive adhesive layer, and the absorbent article comprises, in addition on the outer surface, a mechanical fastener suitable for the Assembly with the mechanical fastening of the adhesive closure tape. The present invention also provides a prelaminated composite tape on a reel, from which a composite adhesive closure tab can be cut, for an absorbent article, the prelaminated composite tape includes an adhesive tape comprising a back reinforcement including a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer; said back reinforcement comprises on said fibrous layer, a silicone release layer and the side of the back reinforcement opposite the side comprising said silicone release layer, comprises a pressure-sensitive adhesive layer; said silicone release layer comprises a cured reaction product of a curable composition, which includes (i) an idioalkyl polyacrylate having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising at least Two groups of reagents, selected from the group consisting of 'an acrylate group and a methacrylate groupsaid adhesive sealing tape has a bond strength at 90 ° of at least 6 N / 2.54 cm, with respect to a surface of polyethylene film and a value of the Keil test not exceeding 1 N / 2.54 cm, a first axial extension section of the rear reinforcement, which has a mechanical fastener disposed on the pressure sensitive adhesive layer and a second axial extension section of the reinforcement has an exposed pressure sensitive adhesive layer, for mounting to a portion of the edge of an absorbent article. In addition, a method is provided for the manufacture of a backcoat coated to facilitate peeling, having a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer, which comprises the steps of coating with a coating composition. to facilitate the release of a curable silicone, the fibrous layer of the posterior reinforcement and cure the coating to facilitate the release of silicone applied in this way, exposing it to actinic radiation or heat; said composition of the coating for facilitating the release of curable silicone comprises: (i) a polydialkylsiloxane having acrylate and / or methacrylate groups and the reaction of the average number of dialkylsiloxane units to the average number of the acrylate and methacrylate groups is included in the range that fluctuates between 10 and 15, and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from a group consisting of an acrylate and methacrylate group; said organic compound without silicon has a viscosity of at least 500 mPas at 25 ° C and the weight ratio of said polydialkyl 1-siloxane with said organic compound is in the range ranging from 8:92 to 35:65. Additionally , the invention relates to a coating composition for facilitating peeling, comprising: (i) a polydialkylsiloxane having acrylate and / or methacrylate groups and the ratio of the average number of dialkyl iloxane units to the average number of acrylate groups and methacrylate, is comprised in the range that fluctuates between 10 and 15, and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from a group consisting of an acrylate and methacrylate group; said organic compound without silicon has a viscosity of at least 500 mPa at 25 ° C and the weight ratio of said polydialqui 1-si loxane with said organic compound is in the range ranging from 8:92 to 35:65, and (iii) optionally, a photoinitiator. Finally, the invention provides a coating for facilitating peeling, obtained by curing a coating to facilitate peeling, comprising: (i) a polydialkyl siloxane having acrylate and / or methacrylate groups and the ratio of the average number of units of dialkyl iloxane to the average number of the acrylate and methacrylate groups, falls in the range ranging from 10 to 15, and (ii) an organic compound without silicon and comprising on the hands two reactive groups, selected from a group consisting of an acrylate and methacrylate group; said organic compound without silicon has a viscosity of at least 500 mPa s at 25 ° C and the weight ratio of said polydialkyl siloxane with said organic compound is in the range ranging from 8:92 to 35:65; and (iii) optionally, a photoinitiator. Brief Description of the Drawings. Figure 1 is a perspective view of a diaper in a closed form; Figure 2 is a schematic representation of a cross section of the tongue of the closure tape of the invention; Figure 3 is a schematic representation of the patch comprising the patch of the mechanical fastener; Figure 4 is a cross-sectional view of the preferred embodiments of the tab of the closure tape of the invention; Figure 5 is a cross-sectional view of the tab of the closure tape mounted to an edge of a diaper, which is shown in the position it has during storage; and Figure 6 is a perspective view of a spool of the closure tape. Detailed description of the invention. The backing of the adhesive tape of the present invention comprises a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer. Examples of the thermoplastic polymers include polyolefins, such as polyethylene and polypropylene and copolymers thereof, polyesters such as polyethylene terephthalate and polyamides, such as NYLON 6 or NYLON 66. The fibrous layer can be formed as a woven or non-woven fabric, by any of the techniques conventionally used in the art. Woven fabrics include those that are manufactured by the processes with which the sets of mechanically interlaced, regular and repetitive fibers are obtained. Non-woven fabrics of thermoplastic polymer fibers include non-woven fabrics, manufactured by any of the commonly known processes, intended for the production of non-woven fabrics, including: dry-laid fabrics (carded or laid by air), wet-laid fabrics and fabrics laid with polymers. The latter are preferred to form the fibrous layer of the posterior reinforcement and can be manufactured by extrusion and calendering techniques (spunbondi n g) or melting and blowing techniques (mel tbl or wi n g) or combinations of both. The extruded and drawn fibers by calender are usually small diameter fibers, which are formed by extruding the molten thermoplastic polymer as filaments from a plurality of thin, usually circular, capillaries of a spinning nozzle; the diameter of the extruded fibers is rapidly reduced. Extruded and drawn fibers with a calender are generally continuous and it is common for them to have an average diameter of at least 7 μm, preferably a diameter ranging from 15 μm to 30 μm. Generally, melted and blown fibers are manufactured by extruding the molten thermoplastic material through a plurality of capillaries of fine, normally circular nozzles such as melted strands or filaments, into a gas stream, generally hot, (eg, air). ) that circulates at a high speed, which reduces the filaments of the molten thermoplastic material, to decrease its diameter. In the following, the melted and blown fibers are transported by the gas stream at high speed and are deposited on a collection surface, to form a randomly distributed fused and blown fiber fabric. The average diameter of the melted and blown fibers is preferably less than 10 μm. Any of the non-woven fabrics can be manufactured from a single type of fiber or two or more fibers that differ in the thermoplastic type and / or in its thickness. In relation to the particular embodiment of the present invention, the post reinforcement may comprise multiple layers of fibrous layers which may vary in the type of fibers used and / or the particular technique that was used to produce the fibrous layer. For example, with regard to the particularly preferred embodiment, the back reinforcement comprises a fibrous layer formed by extruded and drawn fibers with calender and a fibrous layer formed by melted and blown fibers. According to a further embodiment, the back reinforcement may comprise, in the given order, a fibrous layer of extruded and drawn fibers with calender, one or two layers of melted and blown fibers and a fibrous layer of extruded and drawn fibers with calender . The advantage of using a back reinforcement comprising a combination of an extruded and stretched fibrous layer with calender and a melted and blown fibrous layer consists in that the melted and blown fibrous layer can function as a barrier against the absorption of the adhesive coating, in particular , when the latter has a low viscosity. . The fibers of the non-woven fabrics can be joined together for the purpose of providing improved cohesion of the fabric, by any of the known techniques, which include thermal bonding, by the use of an oven or a calender cylinder, which it can be smooth or with reliefs. The joining can also be carried out by means of a needle punching (n eedl e p a ch i n g) or a needle punching (s t i t ch, pun ch i n g). The hydroentangled methods (hydroen t angl em en t) can also be used.

In general, the level of union determines the porosity of the fibrous layer. The fibrous layers commonly have a basis weight varying between 5 g / m2 and 1000 g / m2, preferably between 10 and 100 g / m2 and, more preferably, between 20 and 60 g / m2. In particular, the non-woven fabrics are preferably defined by the basis weight rather than the thickness, which is highly dependent on the measurement techniques. Typically, the fibers of the fibrous layer will have a diameter ranging from 5 μm to 35 μm. While the silicone release liner of this invention is particularly suitable for providing a release liner on these thin fiber based layers, the liner for facilitating silicone release is also suitable for the fiber based liner layers. thick. According to a further embodiment of the present invention, the subsequent reinforcement of the adhesive tape may comprise a laminate of the fibrous layer and a layer of polymeric film. Suitable polymeric film layers include: a polyester film, a polypropylene film, a polyethylene film and other polyolefin films. The polymeric film layer will typically have a thickness ranging from 10 μm to 200 μm and may be advantageous to prevent penetration of the adhesive coating into the fibrous layer. Instead of providing a layer of polymeric film as a barrier against penetration of the adhesive coating into the fibrous layer, it is also possible to calender the fibrous layer with a hot roll, so as to reduce the porosity of the fibrous layer on one side of the same According to the present invention, the fibrous layer of the back reinforcement consists of a silicone release layer. The silicone release layer comprises the cured reaction product of a poly idialkyl siloxane, having acrylate and / or methacrylate groups and an organic compound without silicon and comprising at least two groups of reagents, selected from a group consisting of an acrylate and a methacrylate. Preferred polyalkyl 1-si loxanes include those having a ratio between the average number of dialkyl Isiloxane units and the average number of acrylate or methacrylate groups ranging from 10 to 15. Particularly preferred polydimethylsiloxanes for use in this invention are those having a ratio between the average number of dimethylsiloxane units and the average number of acrylate or methacrylate groups ranging from 10 to 15. The polydialkylsiloxanes suitable for use in this invention, usually have a viscosity that varies in the range between 100 and 500 mPa s. Examples of the silicones suitable for use in this invention are commercially available and include TEGO ™ RC-902 and RC-715, both for sale through Goldschmidt Chemical Corp. The organic compound without silicon for the relationship with the idialkyl - if loxane is, generally, a polyhydroxy acrylated or methacrylated compound, or a polyamino acrylated or methacrylated compound. The organic compound has at least two or more acrylate and / or methacrylate groups, more preferably at least three. The organic compound should also preferably have a viscosity of at least 500 mPa s at 25 ° C and, more preferably, at least 800 mPa s at 25 ° C. Particular examples of the organic compounds for use in the invention include ditrimethylolpropane tetraacrylate, available as E 140 through UCB Chemicals, Belgium, and, E 810, a polyester tetraacrylate which is marketed through UCB. The modified pentaerythritol tetraacrylate (approximate viscosity of 500 mPa s) for sale as SSR-444 through Sartomer, the aliphatic diacrylate oligomer (approximate viscosity of 1000 mPa s) which is marketed as CN-132 through Sartomer, ethoxylated bisphenol A-dimethacrylate (approximate viscosity of 1100 mPa s), available for sale as SR-348 through Sartomer, the diacrylate oligomer of the bisphenol A derivative (approximate viscosity of 1400 mPa a), marketed as E-150, through UCB. On the side of the posterior reinforcement opposite the side containing the silicone release layer, a pressure sensitive adhesive layer is provided. Pressure sensitive adhesives suitable for use in the adhesive layer are the pressure sensitive adhesives that are commonly used in diaper adhesive tapes. The pressure sensitive adhesive must be capable of providing an adhesive tape having one. strength of adhesion at 90 ° of at least 6 N / 2.54 cm. This adhesion strength at 90 ° is the adhesion obtained after the adhesive layer has been in contact with the silicone release layer, ie the adhesive tape must retain a bond strength at 90 ° of at least 6 N /2.54 cm after unrolling it from a reel. Preferably, the pressure-sensitive adhesive layer of this invention comprises a rubber-based adhesive to which the viscosity was modified, by the inclusion of an adhesion resin. The rubber resin preferably comprises a block copolymer A-B-A, wherein the A blocks are derived from a styrene monomer and the B blocks are derived from isoprene, butadiene or the hydrogenated version of. these. Generally, such adhesives are disclosed in U.S. Patent Nos. 3,419,585, 3,679,202, 3,723,170 and 3,787,531, U.S. Patent Nos. 3,676,202 and 3,723,170 disclose the advantages of these adhesives when the B blocks derive isoprene and , preferably, the A blocks are derived from styrene, which include the benefits of the particular adherents. U.S. Patent Nos. 3,519,585 and 3,787,531 disclose the advantages of mixing certain block copolymers A-B with certain block copolymers A-B-A in similar pressure sensitive adhesive formulations. US 5,019,071 and US 5,300,057 disclose a particularly preferred adhesive composition. The preferred adhesive composition comprises a thermoplastic elastomer component and a resin component and the thermoplastic elastomer component essentially consists of about 50 to 90 parts, preferably between about 60 and 80 parts, of an ABA block copolymer of styrene-isoprene-styrene linear or radial and about 10 to 50 parts, preferably, about 20 to 40 parts of a copolymer block AB of styrene-isoprene simple. Blocks A are derived from styrene or styrene homologs and blocks B are derived from isoprene, either alone or together with small proportions of other monomers, both in block copolymers A-B-A and A-B.

As indicated above, the block copolymers A-B-A are preferably of the type consisting of: A blocks (end blocks) derived, ie polymerized, from styrene or styrene homologs; and B blocks (the middle blocks) are derived from isoprene, either alone or together with small proportions of other monomers. The individual A blocks preferably have a number average molecular weight of about 7,000, preferably in the range from 12,000 to 30,000, and A blocks preferably constitute about 10 to 35 percent. by weight of the block copolymer. The number average molecular weight of the B blocks for the linear A-B-A block copolymers is preferably in the range between about 45,000 and 180,000 y. that of the same linear copolymer is preferably in the range between about 75,000 and 200,000. The number average molecular weight of the radial ABA block copolymers is in the range between about 125,000 and 400,000 and that of the corresponding B blocks fluctuates between about 95,000 and 360,000. The ABA radial polymers that they are useful, for example, of the type described in U.S. Patent No. 3,281,383 and conform to the following general formula: (AB-) (n) X, where A is a thermoplastic block polymerized from styrene or from the styrene homologs, B is an elastomeric block polymerized from a conjugated diene -such as butadiene or isoprene-, X is an inorganic or organic connection molecule, with a functionality of 2-4, such as that described in U.S. Patent No. 3,281,383 or, possibly, with greater functionality, as detailed in the article entitled "New Rubber is Ba cked by S ta rs" [Stars endorses new rubber] which was published on page 35 of the Chemical Week edition of June 11, 1975. The number "n" corresponds to the functionality of X. In AB block copolymers derived from styrene-isoprene, the number average molecular weight of the Individual blocks A is typically from about 7,000 to 20,000 and the total molecular weight of the block copolymer generally should not exceed about 150,000. A-B block copolymers based on styrene and isoprene are generally described in U.S. Patent No. 3,787,531. The elastomeric component of the preferred adhesive composition may include small amounts of other more conventional elastomers, but these should not exceed about 25 weight percent of the elastomeric component. These include natural rubbers, synthetic rubbers based on butadiene, isoprene, butadiene-styrene, but adieno-acrylonitrile and the like, butyl rubbers or other elastomers. The preferred adhesive composition includes between about 20 to 300 parts, preferably, 50 to 150 parts of a resin component, per one hundred parts in step of the thermoplastic elastomer component. The resin component consists essentially of the tackifying resins for the elastomeric component. In general, any conventional compatible tackifying resin or the mixture of such resins can be employed. These include hydrocarbon resins, rosin and rosin derivatives, polyterpenes and other adherents. The adhesive layer may also include small amounts of other miscellaneous materials such as antioxidants, heat stabilizers and ultraviolet absorbers, fillers and the like. Typical antioxidants are 2, 5-di-tertiary amylhydroquinone and diteriary butylcresol. Similarly, conventional heat stabilizers, such as the zinc salts of the alkyl di-thiocarbamates, may be employed. Similarly, the particulate mixture of this invention may include small amounts of fillers and pigments, such as zinc oxide, aluminum hydrate, clay, calcium carbonate, titanium dioxide, black carbon and others. Commonly, the adhesive layer is provided with a thickness that varies between 20 and 200 μm and, more preferably, has a thickness ranging from 25 μm to 100 μm. The adhesive tape of the present invention can be made by coating the composition of the silicone release coating on the fibrous layer of the subsequent reinforcement and curing the silicone release coating applied in this way, by exposing it to actinic radiation or the heat. The composition of the curable silicone coating comprises: (i) a polyalkyl 1-siloxane having acrylate and / or methacrylate groups and a ratio between the average number of the dialkylsiloxane units to the average number of the acrylate and methacrylate groups which varies from 10 and 15; and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from the group consisting of an acrylate and a methacrylate group. The organic compound without silicon should preferably have a viscosity of at least 500 mPa at 25 ° C and the weight ratio of the polydialkyl siloxane to the organic compound generally ranges between 8:92 and 35:65, preferably between 10:90 and 30:70. The composition of the silicone release coating can be applied to the fibrous layer of the subsequent reinforcement by any of the conventional methods known in the art of coating. Particular examples of the appropriate coating techniques include: roller coating, brush painting, spraying, reverse roll coating, gravure coating and nozzle coating. In a particularly preferred embodiment of this invention, the composition of the silicone release coating is substantially solvent-free and is applied by a multi-roll coating. When it is said substantially solvent-free, it is to be understood that the coating composition contains less than 10% by weight and more preferably, less than 5% by weight of solvents. - The curing of the coated silicone release composition can be carried out by heat or photochemically, irradiating with actinic radiation such as, for example, electron beam, UV light, X-rays, gamma rays and beta rays. In a preferred embodiment of the present invention, the composition of the silicone release coating also comprises a thermal or photochemical free radical initiator. Examples of useful photochemical free radical initiators, i.e., photoinitiators, which can be used in combination with ultraviolet light, include, for example, benzyl ketals, benzoin ethers, acetophenone derivatives, ethers of ketoxime, benzophenone, benzo- or thio-xanthones, etc. Specific examples of photoinitiators include 2,2-diethoxyacetophenone, 2- or 3- or -bromoacetophenone, benzoin, benzophenone, 4-chlorobenzophenone, 4-phenyl-benzophenone, benzoquinone, 1-chloroant-quinone, p-diacet-1-benzene, 9-10-dibromo-ant racene, 1,3-diphenyl-2-propane, 1,4-naphthyl-phenylacetone, 2,3-pentenedione propiophenone, chlorothioxanthone, xanthone, fluorenone and mixtures thereof An example of a commercially available photoinitiator is available from Ciba Geigy Corporation of Hawthorne, NY under the trade name Darocur 1173. alternative photoinitiator is a mixture of 70% olig o-2-hydroxy-2-methyl-l-4 - (1-methylavinyl) phenyl-propanone and 30% of 2-hydroxy-2-methyl-1-phenyl-1-propanone, available as ESACURE KIP 100F , through Lamberti spa (Albizzate, Italy).

When present, the free radical initiator is typically used in an amount ranging from 1 to 10 parts by weight per 100 parts by weight of silicone and more preferably in an amount ranging from 2 to 5 parts by weight per unit weight. every one hundred parts by weight of silicone. The radiation curable compositions of the present invention can be stabilized against premature polymerization during storage, by the addition of conventional polymerization inhibitors, such as: hydroquinone, hydroquinone monomethether, phenothiazine, dedi -t-but i 1 - paracresol, etc. Generally, amounts of stabilizers of 0.1 percent by weight or less are effective. To obtain an adhesive tape of the present invention, the side of the back reinforcement opposite the side having the silicone release coating composition is provided with an adhesive layer. In order to prevent the adhesive, when the coating is made, from penetrating through the posterior reinforcement, preferably, a barrier is provided to the subsequent reinforcement to prevent said penetration. Suitable barrier means are described above and include: a laminated polymer film, a back reinforcement comprising a combination of extruded and drawn calendered and melted and blown fibrous layers and treatment of a single side of the fibrous layer with a calender hot. The adhesive layer can be provided over the subsequent reinforcement by any of the coating techniques known in the art or it is first possible to coat the adhesive layer to a release liner and then transfer the laminate onto the back reinforcement. Suitable coating techniques for applying the adhesive layer on the backing include heat-melt coating techniques, as well as water or solvent transmission coating techniques, such as knife coating, nozzle coating, the spray, the coating in curtains and the coating in flat platform. After providing the adhesive layer on the backing, the adhesive tape can be wound on itself to obtain the adhesive tape in the form of a roll or reel. The adhesive tape of the present invention is intended for the manufacture of a closure system in an absorbent article and in particular, a closure system in a diaper. Figure 1 is - a perspective view of a disposable diaper 10, in a closed form. The diaper comprises an absorbent core 13 between an inner surface 11 and an outer surface 12. The absorbent core 13 may be any means that is generally compressible, conformable, non-irritating to the user's skin and capable of absorbing and retaining liquids and certain exudates. of the body. The outer surface 12 of the diaper is impermeable to liquids and is preferably manufactured from a thin plastic film, although other flexible, impermeable materials or liquids may also be used. The outer surface 12 prevents the exudate absorbed and contained in the absorbent core from soiling the articles that come into contact with the diaper 1, such as the sheets of the beds and the interior blunt.

The inner surface 11 of the diaper is adaptable, soft to the touch and non-irritating to the wearer's skin. In addition, the inner surface 11 is permeable to liquids, allowing liquids to easily penetrate through their thickness. An appropriate inner surface 11 can be manufactured from a wide range of materials, such as: porous foams, cross-linked foams, films with openings, natural fibers, (for example, wood or cotton fibers), synthetic fibers ( for example, polyester or polypropylene fibers) or from a combination of natural and synthetic fibers. Preferably it is manufactured with a hydrophobic material to isolate the wearer's skin from the liquids retained by the absorbent core 13. An appropriate inner surface can be, for example, a nonwoven propylene carded or extruded and stretched by calender, of approximately 15-25 g / m2. The absorbent core 13 can be secured to the outer surface 12 by means of, for example: pressure-sensitive adhesives, heat-melt adhesives or other adhesives, ultrasonic bonding or heat sealing the side / side by pressure. The outer surface 12 and the inner surface 11 can be joined directly or indirectly, by the use of an intermediate fixing piece, to which the outer surface 12 and the inner surface 11 are joined. The inner surface 11 and the outer surface 12 may be associated with each other by various methods comprising, for example: pressure sensitive adhesives, heat-melt adhesives or other adhesives, ultrasonic bonding and / or heat sealing / pressure sealing. The above description of diaper 10 serves the sole purpose of providing an explanation and not that of imposing limitations. Additional details on diapers and their manufacture are described in the literature, examples being: EP 0,529,681, US 4,036,233, EP 0,487,758, WO 96 / 10,382, US 3,800,796, EP 0,247,855 or US 4, 857, 067. The adhesive tape of the invention can be used in the on-line lamination of all the adjustment components and that facilitate the detachment of the diaper manufacturing line. However, it is often more convenient for a manufacturer to use a simple spool of closure tape that is in the form of prelaminate, with all the elements needed to make the closure system. Accordingly, in connection with a particular embodiment of the present invention, a prelaminated composite tape is also provided, from which the composite adhesive closure tabs can be cut to obtain a closure system in an absorbent article, in particular a diaper Typical components of such a prelaminated composite tape were described in, for example, WO 96/21413. As shown in Figure 2, the composite adhesive closure tab 20 has a back reinforcement-21 comprising the fibrous layer. The adhesive layer 24 is applied to the clamping surface 22 of the back reinforcement 21. The silicone release layer of the invention is provided on the surface of the back side 23 of the back reinforcement 21. The back reinforcement 21 has a clamping surface 22 which is provided with the adhesive layer 24. A patch 26 is located in the first axially extending section 25 of the back reinforcement 21, which comprises a mechanical fastening component 30, on the adhesive layer 24. The second section extending axially 31 of the rear reinforcement 21 will be permanently fixed to the edge portion 14 of the disposable diaper or of the garment 10 in the manufacturing process, by the adhesive layer. Figure 3 shows the general structure of the mechanical fastener patch 26. It is essentially composed of a base sheet 27, with a first surface 29 which can be fixed to the back reinforcement 21 by the adhesive layer 24 and a second surface 28 on which a mechanical fastening component 30 is provided. The base sheet 27 and the mechanical fastening component 30 may be made of the same or different materials. The mechanical fastening component 30 may be part of any of the conventional mechanical fastening systems. A fastening system is a snap fastener comprising two interconnecting materials: one of the components is a material with hook and the other is a material of plush fabric with curls or curls. One component of the mechanical fastening system is part of the patch 26 and the other is on the target area 15 on the outer surface 12 of the disposable diaper or of the garment 10. For example, the target area 15 may be a strip that is fixed to the outer surface 12 of the diaper 10, such that the size of the diaper or garment can be adjusted according to the size of the wearer. The target area may comprise or more strips and could form the entire outer surface 12 of the diaper. Depending on the material of the outer surface 12, it may be possible that the fastening system is fixed in such a way that it can be detached, directly to the outer surface 12. For example, in case the mechanical fastening component 30 comprises a material with hooks, such material with hooks can be fixed to a material comprising woven or non-woven fabrics or any other material that is interlocked with the hooks. The closure system comprises the composite adhesive closure tab 20 with the mechanical fastening patch 26, together with the target area 15. An embodiment is shown in Figure 4 where a spacer 34 is disposed adjacent to the patch 26, on the first extended section 25, to provide a non-adhesive region. The separator 34 can be used in order to make the disposable article more comfortable for the user. The separator can be formed in various ways, such as to provide a region of the back reinforcement 21 without any adhesive layer 24. Alternatively, a stationary material 34 - such as a polymeric film material, paper or nonwoven material - can be attached to the adhesive layer 24. In other embodiments, the area 34 may become non-adhesive, by a contamination designated, for example, with grease, talc or the like. To increase the clamping force of the closure tape, it is possible to use two or more different mechanical fastening components. For example, two materials with different hooks could be used, where the hooks of one of the components are oriented in a direction opposite to that of the hooks of the second component. As also shown in Figure 4, the composite adhesive closure tab comprises an adhesive section 36 which facilitates disposal of the disposable article 10, after use. Additionally, the composite adhesive closure tab 20 can be easily folded inwardly and held in the folded position during storage, as shown in Figure 5. The adhesive section 36 is formed by an uncovered adhesive layer 24 between the patch 26 - which comprises the mechanical fastening component 30- and the edge portion 14. A detachment-facilitating tape 37 is located over the adhesive section 36. The detachment-facilitating tape 37 covers the adhesive section 36 and extends from the edge portion 14 to the non-adhesive area 34. In case the release tape 37 also covers the non-adhesive area 34, it can be easily removed. The other end of the tape to facilitate detachment is provided on the edge portion 14 of the diaper 10. The release tape 37 protects the adhesive section 36 from contamination during storage and transport. Any tape composed of three layers can be used to facilitate proper detachment, such as the tape that facilitates detachment 37, that is, one formed by a backing sheet, comprising an adhesive layer and a non-adhesive layer. For storage and transport, the closure tape is bent by the fold line A and the release tape 37 adheres to the interior surface 11. When the closure tape is folded open for use, the tape stops. facilitating detachment 37 remains on inner surface 11. During use, the open adhesive of section 36 adheres to target area 15 and holds the mechanical fastening system. After use, the diaper 10 can be folded or rolled into a structure such that the closure tape tab still extends outwardly from the wound disposable article 10. Then, the adhesive section 36 is secured, either in the target area 15 or in the backsheet of the outer surface of the backsheet 12, so as to secure the disposable article 10 in its curled configuration so that it can be easily and conveniently disposed of in a waste receptacle. For the distribution of forces during diaper use, a central strip 38 can be located on the line in which the release strip 37 is contiguous with the edge 14 of the diaper. As shown in Figure 4, the composite adhesive closure tab comprises a lifting wing 33. In one of the possible embodiments of a lifting wing, the material used to make the lifting wing 33 will be a thin film, for example a polypropylene film, non-woven or paper. The thin film is fixed to the clamping surface 22 at the free end 32 of the first axially extending section 25 of the back reinforcement 21. In an alternative embodiment, the free end 32 of the backing sheet 21 is a layer free-form adhesive 24. In a third alternative embodiment the free end 32 of the holding sheet 21 is completely coated with the adhesive layer 24 and then folded over. The width of the reel of the prelaminado compound depends on the application that is intended to give. Generally, the reels of the prelaminated composite tape for the disposable articles have a width of about 30 to about 100 mm and, preferably, from about 50 to about 70 mm. In order to provide a closure tape system that can be wound onto a stable reel, the first axially extending section 25 occupies 55 to 70% and the second axially extending section 31, 30 to 45% of the width of the strip. In the case in which a lifting wing is used, the lifting wing occupies between 8 and 12%, the extension section 25 ranges from 46 to 62% and the axially extending second section 31, occupies from 30 at 42% of the total width of the strip. The composite adhesive closure tab 20 can be cut from a reserve reel 44. During use, a segment of the spool 44 is cut from a prelaminated composite tape 45 of the reel to a desired length; see Figure 6, where the line shows where the tape is cut into tabs. Immediately thereafter, the clamping surface 22 of the back reinforcement 21 is secured to the outer surface 12 of the portion of the edge 14 of the diaper or the garment 10. The first axially extending section 25 is folded around the edge portion 14. and the closure tape is placed folded, as shown in Figure 5.

Now, it is in the position prior to use. The closure tape is folded so that it does not unfold before use or during manufacturing and storage. It is contemplated that a diaper is sold to the consumer in these conditions. During use, a diaper 10 containing a composite adhesive closure tab 20 of the present invention is placed around the wearer's body. To adjust the diaper 10, the folded composite adhesive closure tab 20 was unfolded, for example the lifting wing 33 is taken and then the tape 20 is unfolded. The extended section 25, which comprises the mechanical fastening component 30, is then secured to the outer surface 12, preferably to the target area 15. The same procedure is followed for the other side of the user and thus, the diaper is secured in place. . The invention is further illustrated by means of the following drawings, however, without the intention of limiting the invention to them. EXAMPLES Test Methods Measurement of the Quantity of the Composition to Facilitate Detachment on the Surface of a Fibrous Layer The amount of the composition to facilitate the detachment present on the surface of the fibrous layer was measured using an X-ray fluorescence analyzer, 200 TL model, marketed through ASOMA Instruments, Austin, Texas. The test method is available from Th. Goldschmidt AG, Essen, Germany, in two parts: a calibration technique, which is sold as KM RC 005 A and a measurement technique, marketed as SM 316 A. The calibration technique comprises , first, coating and curing known amounts of the polydimet i 1 if UV curable loxane (PDMS) (available as TEGO-RC 726 through Th. Goldschmidt) on a polyester film. At least five different weights of known coatings were coated, UV cured and their fluorescence measured by X-ray. A calibration curve was then prepared that related X-ray fluorescence to the amount of PDMS present.

The measurement technique employs the X-ray fluorescence of the silicon atoms. A test substrate having an unknown amount of silicone on its surface is subjected to X-ray fluorescence. The absolute value of the fluorescence is measured and the corresponding amount of the PDMS of the calibration curve is read. Then, the actual amount of the composition was calculated to facilitate surface detachment, from the amount of PDMS measured, using the following formula: Composition to facilitate the release on the surface in g / m2 = (g of PDMS / m2 measured on the coated substrate - g of the PDMS / m2 measured on the uncoated substrate) /. Factor for the composition to facilitate detachment. The elements to be entered in the formula are determined by the following: 1. The g of the PDMS / m2 measured on the coated substrate is read on the calibration curve that relates the amount of fluorescence to the amount of the PDMS present. 2. The g of the PDMS / m on the uncoated substrate is the value measured for fibrous fabrics without composition to facilitate detachment (corresponding to a "blank" measurement). 3. Th. Goldschmidt provides a factor in the test method (an "RC number") for each of the UV curable (meth) acrylated silicones. This is essentially the fraction of the UV curable silicone that is the PDMS. The factor is always lower than 1.0 and is lower for UV curable silicones that have less silicone content (more acrylate groups). The factor for the composition to facilitate the detachment is calculated in an average way by measuring the weight, using the quantity and the factor for each one of the materials used. Additives that do not have polydimet il-siloxane units (free of silicone atoms) are assigned a factor of zero. Adhesion force at 90 ° Adhesion strength was measured using a portion of the unwound tape from the tape reel, as prepared in the examples. The test evaluated the ability of the adhesive tape to adhere to a polyethylene film after the adhesive had been in contact with the material that facilitates the release based on silicone. The polyethylene film used in this test was prepared as follows. A low density polyethylene resin (Tenite 1550P, marketed through Eastman Chemical Co., Kingsport, Tennessee) having a melt index of 3.5 grams / 10 minutes and a density of 0.918 grams / cm 3, was extruded to a melting temperature of 182 ° C, vertically, downwards, through an extrusion die of the groove of the coating apparatus. The molten substance that exited through the nozzle was brought to a pinch formed by a chrome roller with specular finish (inlet water temperature of 8 ° C) and a silicone rubber roller (inlet water temperature of 7 s C). ), which resulted in a film 330 microns thick. The surface of the film in contact with the chromium roller was used for testing purposes. The surface of the film used to test the bond strength had an average surface irregularity value Ra of 1.4 μm and an average height value from the peak to the depression R: of 12.5 μm. The irregularity values Ra and Rz were determined by a laser profilometer marketed through UBM Messtechnik GmbH, Ettlingen, Germany, model number UB-16. The irregularity values were calculated by this machine, in accordance with German Industry Standard (DIN) 4768 and DIN 4762. The substrate for the test was first prepared by firmly bonding the polyethylene film to the surface of the The stainless steel test plate. The polyethylene film was adhered to the test plate with double-sided tape (available as Tape 410 through 3M Company). The strength of adhesion at 90 ° was measured using a tensile tester in a special configuration, to allow a 90 ° detachment angle that should be maintained during the test. The configuration of the equipment is described in the FINAT NO 2 TEST METHOD, a conventional 90 ° peel test method (marketed through the Federation Internationale des Fabricants Europeens et Transformateurs d'Adhesifs et Thermocollant s sur Papier eu autres Supports ( FINAT)). There were several exceptions to the FINAT method described, which are given below: 1) FINAT 2 requires a glass substrate that was replaced by a polyethylene film. 2) a "conventional FINAT test roller" was replaced by a 2 kg roller. 3) the sample was wound once in each direction, at 300 mm / minute, instead of twice at 200 mm / minute as required by the FINAT method. 4) the retention time was essentially zero, unlike 20 minutes and 24 hours respectively, as required by the FINAT method. A sample of the test tape 30 cm long and 2.54 cm wide adhered to the polyethylene surface (the surface of the film that was in contact with the chromium roller during production) of the test plate , rolling it twice with a 2 kg roller. A portion of the end of the tape was left free to take it into the test apparatus as described by the test method. After a retention time of less than one minute, the test tape was peeled from the polyethylene substrate at a speed of 300 mm / minute. The detachment at 90 ° was recorded in units of N / 2.54 cm. Three samples were evaluated and the results averaged. Winding force of the spool (initial and then - aging) The winding force was measured according to the Association Des Fabricants Europeens De Ruban Auto-Adhesifs (AFERA) 4013. A reel of adhesive tape prepared according to the examples was evaluated. and with an approximate length of 30 m and a width of 5 cm, using a modified tensile tester. The winding speed was 500 m / minute. The winding force was recorded in cN / 2.54 cm. Three measurements were made and the results averaged. The winding force was measured on tape reels that had been prepared and stored under ambient conditions for 24 hours, as were the ribbon reels that had been stored in a forced air oven at 50 ° C for 15 days. 90 ° detachment (modified Keil test) This test represents a second method (in addition to the reel winding) to measure the force required to separate an adhesive tape from a coated surface to facilitate detachment. A test strip 5 cm wide and 10 cm long was adhered to a steel substrate, placing the adhesive surface on the plate and enlisting twice with a 2 kg roller. A test strip 2.54 cm wide and 10 cm long was then placed on top of the test tape, so that the adhesive layer of the second test tape was in contact with the coating to facilitate the release of the test tape. first substrate tape. The test tape was rolled twice with a 2 kg roller. Then he . Laminated tape was placed in an oven with forced air at 70 ° C and then a weight of 450 g was left to rest on the laminate of tapes attached for 20 hours, while heating to 70 ° C. Next, the ribbon laminate was removed from the oven and allowed to stand at 23 ° C and 50% relative humidity, for 24 hours before the test. The adhesive of the second tape was peeled from the backing of the first tape using the 90 ° bond strength method described in the 90 ° Sheet Adhesion test, at a peel rate of 300 mm / minute. Each material was evaluated three times and the results were averaged. The data were recorded in cN / 2.54 cm. Materials used in the Examples and in the Comparative Examples Functional silicones by (meth) acrylate RC 706 is an acrylate-functionalized polydimethylsiloxane, having a functionality of (8: 0) available as TEGO RC-706 through Th. Goldschmidt AG, Essen, Germany. RC 708 is a mixture of 70/30 weight by weight of a poly idimet i ls iloxane functionalized with acrylate (RC.726, functionality 108: 6 or 18) and an MQ resin, a functional silicone resin that, as is known , increases the forces to facilitate detachment. RC 708 is available as TEGO RC-708, through Th. Goldschmidt AG, Essen, Germany. RC 711 is a polydimet i lsi functionalized with acrylate having a functionality of 10: 4 (2.5) available as TEGO RC-711 through Th. Goldschmidt AG, Essen, Germany. RC 715 is an acrylate-functionalized polydimethylsiloxane having a functionality of 26: 2 (13.0) available as TEGO RC-715 through Th. Goldschmidt AG, Essen, Germany . RC 726 is an acrylate-functionalised idimet il siloxane that has a functionality of 108: 6 (18.0) available as TEGO RC-726 through Th. Goldschmidt AG, Essen, Germany . The RC-902 is a polydim i ls iloxane functionalized with acrylate that has a functionality of 56: 4 (14,0) available as TEGO RC-902 through Th. Goldschmidt AG, Essen, Germany . "Functionality" is defined as the ratio of the average number of dimethyl-si loxane units / average number of (met) acrylate groups.

Organic Compounds E 140 di t rimet ilol-propane tetracrilate (DMPTA, MW 438 viscosity = 1100 mPa available as E 140 through UCB Chemicals, Drogenbos, Belgium E 810 polyester tetraacrylate, MW = ca 1000, viscosity = 500 mPa s, available as E 810 through UCB Chemicals, Drogenbos, Belgium.

SR 610 Polyethylene glycol diacrylate 600, viscosity = about 50 - 100 mPa s, available as SR 610 through Cray Valley Sartomer, Paris, France. HDDA Hexandiol-diacrylate, Viscosity = approximately 10 mPa s TPGDA Triprolylene glycol diacrylate, viscosity = close to 15 mPa s. UV polymerization initiator DAROCUR 1173 UV 2-hydroxy-2-met il-1-phenyl-1-propan-1 -one, commercialized through Ciba Geigy, Basel, Switzerland. EXAMPLE 1 A subsequent reinforcement was prepared by initially heat embossing a nonwoven polyopropylene fabric, extruded and drawn by a calender of 50 g / cm 2 (the fiber thickness is about 20 microns, available as DALTEX 1050 through Don &Low, Angus, Scotland) with a pattern of diamond-shaped spots, with an approximate width of 6 mm. The total recorded area was 19%. Then, the etched nonwoven was heat laminated to a 30 g / m2 film comprising a polyolefin blend (75% polypropylene, available as PPC 5660 through FINA and 25% linear low density polyethylene (LDPE) ) available as LE 7520 through Borealis, Lyngby, Denmark). A 30 wt% UV curable silicone mixture (available as TEGO RC-715 through Th. Goldschmidt AG, Essen, Germany), ditrimet i lol-propantet raacri lato 70%, by weight (DMPTA) nPM was prepared. = 438, viscosity = 1100 mPa s, available as E 140 through UCB Chemicals) and a UV polymerization initiator 3% by weight (available as DAROCUR 1173, through Ciba Geigy, Basel, Switzerland), mixing the three components using a motor driven propeller mixer for 10 minutes at a temperature of 23 ° C, to obtain a homogeneous milky white suspension. Then, the suspension was applied to the non-woven surface of the back reinforcement in an amount of 2.5 g / m2, using a coater with multiple rolls. Next, the coating was cured in an inert atmosphere (nitrogen), using light UV by passing the coated non-woven fabric - under mercury lamps of 120 W / cm of medium pressure (available as MODEL F-450 through Fusion UV Systems, Inc., Gai Thersberg, Maryland). The distance from the lamp to the surface of the rear reinforcement was 2.5 cm. Then, a single layer of the pressure sensitive adhesive was applied to the opposite side, which has the film, of the backing. The adhesive was based on a mixture of a synthetic block copolymer and an adherent resin and applied by conventional heat fusion coating techniques, using a tilting nozzle in an amount of 35 g / m2. The adhesive tape prepared in this way was rolled up on a reel and then cut into thinner 2.54-cm-wide reels. The components used for the manufacture of the adhesive tape are condensed in Table 1.

The reel prepared in this way was unrolled and tested in order to determine the adhesion and shear with the polyethylene. The spool winding forces were measured. A Keil test was also used to measure the peel force between the adhesive layer and the fibrous layer coated in silicone. The behavior and properties of the adhesive tape are summarized in Table 2. Examples 2 and 3 Example 1 was repeated with the exception that the amount of silicone in the composition to facilitate the release was reduced to 20% and 10%, respectively. Example 4 Example 1 was repeated, with the exception that RC-902 (functionality = 14, viscosity = approximately 350 mPa s) was replaced by RC 715. Example 5 Example 2 was repeated with the exception that the compound organic used was a polyester tetraacrylate, MW = approximately 1000, viscosity = 500 mPa s, available as E 810 through UCB Chemicals, Drogenbos, Belgium.

Example 6 Example 6 used the same coating composition to facilitate peeling as in Example 1 (a mixture of a UV curable silicone 30 wt% (available as TEGO RC-715 through Th. Goldschmidt AG, Essen, Germany), ditrimetylolpropanetraacrylate 70% by weight (DMPTA) nPM = 438, viscosity = 1100 mPa s, available as E 140 through UCB Chemicals) and 3 parts by weight based on 100 parts by weight of the composition to facilitate the detachment of UV photoindicator (available as DARACUR 1173 through Ciba Geigy, Basel, Switzerland). The coating was applied to facilitate detachment to a non-woven back reinforcement where, however, the film layer was not present. The non-woven was a heat-etched, extruded and drawn calender fabric, 50 g / m2 (the fiber thickness of approximately 20 microns, available as DALTEX 1050 through Don &Low, Angus, Scotland) with a stamped pattern in diamond shape, with a width of approximately 6 mm. The total recorded area was 19%.

A thicker layer of pressure-sensitive adhesive was applied to the non-woven side opposite the composition to facilitate peeling, as compared to examples 1 to 5. More adhesive was applied, since part of the adhesive penetrated the nonwoven because the film barrier was not present. Table 1 summarizes the construction of the tape and Table 2 summarizes the properties of the adhesive tape. Comparative Example 1 Example 1 was repeated, with the exception that the organic compound used as part of the coating composition to facilitate the release was hexanediol diacrylate. (viscosity, approximately 10 mPa s) to 90% by weight, in combination with silicone (met) acrylate RC 715. The viscosity of the composition to facilitate peeling during the coating was about 38 mPa s. After applying and curing the coating composition, only 0.5 g / m2 of coating could be measured to facilitate peeling on the surface of the non-woven fabric. The tape reel that was obtained unrolled with difficulty and there was delamination of the fibers of the subsequent reinforcement on the PSA. The subsequent reinforcement was damaged and the adhesive surface was highly contaminated with fibers. Comparative Example 2 Comparative Example 1 was repeated with another organic compound of low viscosity combined with RC 715. The organic compound which was used was tripropylene glycol diacrylate (TPGDA) having a viscosity of 15 mPa s. The viscosity of the coating to facilitate the release of the composition was around 48 mPa s. The composition, to facilitate detachment, penetrated mostly into the non-woven fabric (as in Comparative Example 1, leaving little effective silicone on its surface.) As the tape reel obtained was unwound, a of intense lamination of the back reinforcement, as in Comparative Example 1. Comparative Example 3 Example 1 was repeated with the exception that in place of the RC-715 silicone 30% by weight, a mixture of UV-curable silicones was used, The silicone mixture has the trade name TEGO RC 708 and is a 70/30 mixture, weight of an acrylate-functionalized polydimethexanoate (RC-726, functionality 108: 6 or 18) and MQ resin The MQ resin is known to have the effect of increasing the release force in the release release compositions that are used, RC 708 is sold as TEGO RC-708 through Th. Goldschmidt AG, Essen, Germany. mixture of silicones was combined with di t-rimethylolpropane tetraacrylate, 70% by weight (DMTPA, MW = 438, viscosity = 1100 mPa s, available as E 140 through UCB Chemicals), as in Example 1. The Keil test measured the detachment force and was 433 cN / 2.54 cm. By the MQ resin, it was observed that the peeling force was very high and the subsequent reinforcement was delaminated as the adhesive layer peeled off. Comparative Example 4 Comparative Example 4 was prepared using a functional polydimethylsiloxane by (meth) acrylate (functionality = 18) available as RC-726 through Th. Goldschmidt AG, Essen, Germany. This silicone has a low number of acrylate groups available for curing and was difficult to cure quickly at economically accessible line speeds and in curing conditions in relatively open fabrics, exposed to traces of oxygen. The silicone release composition was not effectively cured and was transferred -at least partially- to the adhesive surface, as the adhesive separated from the layer to facilitate peeling. The adhesive surface of the tape did not have an acceptable adhesion to polyethylene after being contaminated with uncured silicone. Comparative Example 5 Comparative Example 5 used a release release composition comprising two silicone components commonly recommended by suppliers of UV curable silicones. There was no additional organic compound. The release characteristics of this recommended composition are not suitable for use with the highly aggressive pressure sensitive adhesives commonly used in the diaper industry. Comparative Example 6 A conventional silicone blend was used as recommended by the manufacturers, for providing fast curing and low release properties. The yield that was obtained after aging showed delamination of the tape. Comparative Example 7 Example 7 was repeated with the exception that a functional silicone was used for (meth) acrylate having a high functionality (8.0). This silicone is marketed in place as TEGO RC-706 through Th. Goldschmidt Ag, Essen, Germany. An excessively high detachment or release force was observed, as determined by the Keil test. Due to the high acrylic functionality of the silicone, there was less silicone available to provide ease in peeling. Comparative Example 8 Example 1 was repeated, with the exception that a release-facilitating composition having only 5% by weight of the RC 715 silicone was used. Tests show that an effective total weight (2.5 g / m2, see Table 1) of the coating composition to facilitate peeling was present on the surface of the fibrous nonwoven layer after curing, but the total silicone content was too low to provide effective release of the rubber / resin adhesive aggressive that was used. The value measured by the Keil test was 132 cN / 2, 54 cm. Comparative Examples 9 and 10 Example 1 was repeated, with the exception that the release-facilitating compositions had 40% RC 715 and 70% RC 715, respectively, as summarized in Table 1. Both showed excessively highs as measured by the Keil test, as seen in Table 2. Comparative Example 11 Example 1 was repeated with the exception of • that the organic compound that was used was a polyethylene glycol 600 diacrylate, which has an approximate viscosity of 50. at 100 mPa s, on sale as SR 610 through Cray Valley Sartomer, Paris, France. The viscosity of the coating composition to facilitate peeling during coating was 134 mPa s and, therefore, was excessively absorbed by the fabric before curing, as indicated by the measured coating weight of 1.0 g / m2 . There was not enough material to facilitate the detachment on the surface of the fibrous fabric and, therefore, the separation force that measured the Keil test was excessively high (120 cN / 2, 54 cm).

Table 1 F = Polymeric film NT = Non-woven thermally engraved Table 2 * Delaminated tape when trying to unwind it from the reel. The fibers of the nonwoven were transferred to the adhesive surface.

** The silicone coating was poorly cured. - Without measurement. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (16)

1. Claims Having described the invention as above, the content of the following claims is claimed as property. An adhesive tape comprising a posterior reinforcement, characterized in that it includes a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer; the back reinforcement has a first side on the fibrous layer with a silicone release layer and a second side of the back reinforcement, opposite the first side, having on it a pressure-sensitive adhesive layer; the silicone release layer comprises a cured reaction product of a curable composition, which includes: (i) a polydialkyl siloxane having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from the group consisting of an acrylate [y] or a methacrylate group, said adhesive tape having a bond strength at 90 °, of at least 6 N / 2.54 cm, relative to a surface of polyethylene film and said adhesive tape has a Keil test value not exceeding 1 N / 2, 54 cm. The adhesive tape according to claim 1, characterized in that the back reinforcement comprises a laminate of the fibrous layer and a layer of plastic film. 3. Adhesive tape according to claim 1, characterized in that the ratio of the average number of the dialkyl Isiloxane units to the average number of the acrylate and methacrylate groups of the polydialkyl siloxane is between 10 and 15 and because the organic compound It has a viscosity of at least 500 mPa at 25 ° C. 4. Adhesive tape according to claim 1, characterized in that the poly idialkyl-si loxane is a polydimethylsiloxane. 5. The adhesive tape according to claim 1, characterized in that the adhesive layer comprises a rubber-based adhesive comprising an adherent resin. The adhesive tape according to claim 5, characterized in that it comprises styrene-isoprene-styrene block copolymers. 7. The adhesive tape according to any of the preceding claims, characterized in that it is in the form of a spool. 8. A prelaminated composite tape on a reel from which a composite adhesive closure tab for an absorbent article can be cut, the prelaminated composite tape is characterized in that it includes an adhesive tape comprising a back reinforcement, which includes a woven or non-woven fibrous layer of thermoplastic polymer fibers; the back reinforcement has the fibrous layer with a silicone release layer and a second side of the posterior reinforcement opposite the first, having a pressure-sensitive adhesive layer thereon; the silicone release layer comprising a cured reaction product of a curable composition, which includes (i) a polydialkyl siloxane having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising at least Two groups of reagents selected from a group of an acrylate or a methacrylate, the adhesive tape has a strength of adhesion at 90 °, of at least 6 N / 2.54 cm relative to a surface of polyethylene film and a value of Keil test not greater than 1 N / 2.54 cm, a first axially extending section of the posterior reinforcement has a mechanical fastener located on the pressure-sensitive adhesive layer, and a second axially extending section of the posterior reinforcement it has an exposed pressure-sensitive adhesive layer for attaching it to a portion of the edge of an absorbent article. 9. The prelaminated composite tape according to claim 8, characterized in that the back reinforcement comprises a laminate of a fibrous layer and a polymeric film. 10. The prelaminated composite tape according to claim 8, characterized in that the ratio of the average number of dialkyl iloxane units to the average number of the acrylate and methacrylate groups of said polydialkyl siloxane is between 10 and 15 and said organic compound has a viscosity of at least 500 mPa at 25 ° C. 11. An absorbent article, characterized in that it comprises an adhesive closure tape attached to a portion of the edge; the adhesive closure tape comprises a back reinforcement which includes a fibrous woven or nonwoven layer of thermoplastic polymer fibers; the back reinforcement has a first side formed by the fibrous layer with a silicone release layer and a second side of the back reinforcement opposite the first side having a pressure sensitive adhesive layer thereon; the silicone release layer comprises a cured reaction product of a curable composition, comprising (i) a polyalkyl 1-siloxane having acrylate and / or methacrylate groups, and (ii) an organic compound without silicon and comprising minus two reactive groups, selected from a group of an acrylate or a methacrylate; the adhesive tape has a bond strength at 90 ° of at least 6 N / 2.54 cm in relation to a polyethylene film surface and the adhesive tape has a Keil test value of not more than 1 N / 2, 54 cm, a first section of the adhesive closure tape that is adhered to the edge portion of the absorbent article by the pressure sensitive adhesive layer and a second section of the adhesive closure tape having a mechanical fastener located on the layer pressure-sensitive adhesive, and the absorbent article further comprises a mechanical fastening on the outer surface, capable of being coupled with the mechanical fastening of the adhesive closure tape. 12. A method for manufacturing a coated backing to facilitate peeling, characterized in that it has a fibrous layer of woven or non-woven fibers of thermoplastic polymer, which comprises the steps of coating with a curable silicone release coating composition, on the fibrous layer of the back reinforcement and curing the silicone release coating applied in this way, by exposing it to actinic radiation or heat; the curable silicone release coating composition comprises: (i) a polydialkyl 1-si loxane having acrylate and / or methacrylate groups and a ratio between the average number of the dialkylsiloxane units and the average number of the acrylate and methacrylate groups which varies between 10 and 15; and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from the group consisting of an acrylate and a methacrylate group; said organic compound without silicon has a viscosity of at least 500 mPa s at 25 ° C and the weight ratio of said polydialkyl-siloxane to said organic compound generally varies between 8:92 and 35:65. 13. The method according to claim 12, characterized in that the curable silicone release coating composition further comprises a photoindicator and the coating to facilitate detachment is exposed to actinic radiation. The method for manufacturing an adhesive coated tape, characterized in that it comprises the steps of providing a subsequent reinforcement • coated to facilitate detachment by the method according to claim 12, and of applying an adhesive layer to the side of the subsequent reinforcement opposite to the side that has the silicone release liner. 15. A coating composition for facilitating detachment, characterized in that it comprises: (i) a polydialkyl 1-siloxane having acrylate and / or methacrylate groups and the ratio of the average number of dialkyl iloxane units to the average number of acrylate groups and methacrylate is between 10 and 15, (ii) an organic compound without silicon and comprising at least two reactive groups, selected from a group consisting of an acrylate and a methacrylate group; the organic compound without silicon has a viscosity of at least 500 mPa at 25 ° C, and the weight ratio of the polyalkyl 1 -siloxane to the organic compound is between 8:92 and 35:65, and (iii) optionally, a photoindicator 16. A coating for facilitating the detachment obtained by curing a coating to facilitate detachment, characterized in that it comprises: (i) a polydialqui 1-si loxane having acrylate and / or methacrylate groups and the ratio of the average number of units of dialkylsiloxane to the average number of the acrylate and methacrylate groups is between 10 and 15, (ii) an organic compound without silicon and comprising at least two reactive groups, selected from a group consisting of an acrylate and a methacrylate group; the organic compound without silicon has a viscosity of at least 500 mPa at 25 ° C, and the weight ratio of the poly idialkyl-loxane to the organic compound is between 8: 92 and 35:65, and (iii) optionally, a photoindicator Summary of the Invention The present invention provides an adhesive tape comprising a backing, which includes a fibrous layer of woven fibers or non-woven fibers of a thermoplastic polymer; said back reinforcement comprises on said fibrous layer, a silicone release layer and the side of the back reinforcement opposite the side comprising said silicone release layer, comprises a pressure-sensitive adhesive layer; said silicone release layer comprises a cured reaction product of a curable composition, which influences: (i) a polydialkyl siloxane having acrylate and / or methacrylate groups and (ii) an organic compound without silicon and comprising at least two reactive groups, selected from the group consisting of an acrylate and a methacrylate group, said adhesive tape having a bond strength at 90 °, of at least 6 N / 2.54 cm, relative to a polyethylene film surface and said tape Adhesive has a Keil test value of not more than 1 N / 2.54 cm. The adhesive tape is suitable for the manufacture of fabric-like closure systems for absorbent articles such as diapers.