MXPA00007740A - Breathable backing for an adhesive article - Google Patents

Abstract

There is provided pressure-sensitive adhesive coated breathable nonwoven tape backing substrate where the nonwoven tape backing comprises a fibrous nonwoven web formed in part by multicomponent fibers having an adhesive component region. The multicomponent fibers are distributed throughout the width dimension of the nonwoven tape backing such that adhesive component region is exposed on both outer faces of the nonwoven tape backing. The adhesive component region is preferably a pressure-sensitive adhesive region formed by hot melt coextrusion of at least two components to form the multicomponent fibers. A pressure-sensitive adhesive tape layer is coated onto at least one face of the nonwoven tape backing which pressure-sensitive adhesive tape layer is preferably of the same type of adhesive as that forming the adhesive region of the multicomponent fiber or is at least compatible with the adhesive region of the multicomponent fiber such that the adhesive has enhanced adhesive properties to the pressure-sensitive adhesive tape layer.

Description

SUPPORT FOR AN ADHESIVE ARTICLE WITH CAPACITY TO ALLOW BREATHING BACKGROUND OF THE INVENTION The invention relates to pressure sensitive adhesive products having a support capable of allowing respiration particularly to adhere to the skin or similar surfaces.

Pressure sensitive adhesive tapes and the like are used in a variety of applications where there is a need for a support capable of allowing breathing. Generally these tapes are designed for their adhesion to a surface that is a source of moisture like the skin; however, porous articles can be a source of moisture if they are in communication with a source of a fluid. Tapes designed to adhere to the skin include, for example, medical tapes such as wound or surgical bandages, athletic tapes, surgical drapes or tapes or adhesive labels used to adhere medical devices such as sensors, electrodes, ostomy appliances or the like. The lack of a capacity that allows respiration in these tape products can result in over hydration and sometimes the REF .: 122228 skin maceration. The North American Patent No. ,614,310 suggests, for example, the use of a support that has a value of wet steam transmission amount (MVTR) of at least 500 g / m2 / day (measured using the method ASTM E 96-80 at 40 ° C).

A discontinuous adhesive cover on a support with breathing capacity allows the skin to breathe, at least in areas of the support not covered with adhesive. This criterion is described in US Patent Nos. 4,595,001 (Potter); US 5,613,942; EP 353972; and EP 91800. These patent documents generally disclose intermittent coats of adhesives on different supports. For example, U.S. Patent No. 5,613,942 discloses pressure sensitive printing adhesives using a calender roll process with separable coverage similar to gravure printing. This patent discloses screen printing. However, the pattern of coverage or printing of adhesives is problematic in this way because it generally requires solvents, which are problematic for the environment. It would be preferable from environmental, manufacturing and operating perspectives to have adhesives that would be coated directly from a molten phase.

With polyolefin-type tape supports and the like and as low energy materials there is often a need to increase the surface energy of the support material to allow the pressure sensitive adhesive to remain securely attached to the support. Generally this is called a primer and can be done with surface treatments such as flame treatments, crown treatments or similar oxidative surface treatments. This is generally acceptable but requires a separate process step that complicates the manufacture of the product belt. It is also known to apply primer coats to a surface of the support. Often these are curable coverages such as those described in U.S. Patent Nos. 5,639,546; 5,631,079; and 5,503,927. Although effective, they require one or more additional process steps and can occlude the pores of a porous support. Fused additives and tie layers are also commonly used with film supports, which eliminate the need for a separate priming step, however these films are generally non-porous. The invention is intended to provide a product of a pressure sensitive adhesive tape backing which is simple to manufacture, which does not require a separate priming step, and which is also extremely capable of allowing respiration.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to a substrate of a support for a pre-coated adhesive tape sensitive to non-woven pressure with a capacity to allow respiration wherein the non-woven web support comprises a fibrous network non-woven in part by multicomponent fibers having a region of the adhesive component. The multicomponent fibers are distributed across the width dimension of the non-woven tape such that the region of the adhesive component is exposed on both outer surfaces of the nonwoven tape carrier. The region of the adhesive component is preferably a pressure-sensitive adhesive region formed by a hot-melt co-extrusion of the adhesive component and at least one non-adhesive component forming the multicomponent fibers. The support of the nonwoven tape is preferably formed simultaneously with the formation of the multicomponent fibers or simultaneously with the collection of multicomponent fibers within the nonwoven support.

The layer of pressure sensitive adhesive tape is covered on at least one side of the nonwoven tape carrier whose pressure sensitive adhesive layer is preferably of the same type of adhesive as that which forms the adhesive region of the multi-component fiber or is at least compatible with the adhesive region of the multicomponent fiber in such a way that the adhesive has improved adhesive properties to the layer of the pressure-sensitive adhesive tape. By improved adhesive properties it is understood that the layer of the pressure-sensitive adhesive tape adheres more strongly to the region of the adhesive material than the non-adhesive region of the multi-component fiber. Preferably the layer of the pressure-sensitive adhesive tape possesses breathing capability to provide a product tape capable of allowing respiration.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a nonwoven tape carrier of the present invention made of multicomponent fibers.

Figure 2 is a cross-sectional view of a non-woven tape carrier of Figure 1 at a greater magnification showing a three-layer construction of the fibers.

DETAILED DESCRIPTION OF THE INVENTION The nonwoven tape backing covered with pressure sensitive adhesive is formed from coherent multicomponent fibers having at least one pressure-sensitive adhesive region or layer and at least one non-pressure sensitive adhesive region or layer. The fibers forming the support of the non-woven tape are intimately intertwined with one another in the form of a coherent fibrous nonwoven tape carrier with a capacity to allow breathing. Suitable supports of non-woven ribbons can be formed as meltblown microfibers using the apparatus discussed, for example, in Wente, Van A., "Superfine Thermoplastic Fibers", Industrial Engineering Chemistry, Vol. 48, pages 1342-1346, Wente, Van A. et al., "Manufacture of Superfine Organic Fibers", Report No. 4364 of Navel Research Laboratories, published May 25, 1954, and US Patents Nos. 3,849,241; 3,825,379; and others. These microfine fibers are called blown fibers or blown microfibers (BMF [blown microfibers]) and are generally substantially continuous and form a coherent network between the die of the outlet orifice and a collection surface by the interlacing of the microfibers that it is due in part to the turbulence of the air stream to which the fibers are subjected. Another conventional spin-type melt process, such as the twisted loop processes wherein the fibers are collected in a net form immediately upon formation of the fiber, can also be used to form the support for the nonwoven tape. Generally, the fibers are 100 microns or less in diameter when they are formed by the rotation-type melt processes, preferably 50 microns or less. If multicomponent fibers are formed by the meltblowing process, they can be produced as described in US Pat. Nos. 5,176,952 (Joseph et al.); 5,232,770 (Joseph); 5,238,733 (Joseph et al.); 5,258,220 (Joseph); or 5,248,455 (Joseph et al.). The multicomponent fiber can also be produced by a twisted loop process as described in U.S. Patent Nos. 5,695,868 (McCor ach); 5,336,552 (Strack et al.); 5,545,464 (Stokes); 5,382,400; 5,512,358 (Shawyer et al.); or 5,498,463 (McDowall et al.).

Blow molding processes are particularly preferred because they form self-generating linked networks that typically do not require additional processes to effectively link the fibers to one another in a coherent network. The meltblowing processes used in the formation of multilayer microfibers as described in the patents of Joseph (et al.) Listed above are particularly suitable for use in the manufacture of multilayer microfibers of the present invention. Such processes use hot air (for example equal to, or from about 20 ° C to about 30 ° C higher than the melting temperature of the polymer) at high speed to extract and attenuate the extruded polymer material of a die, which will generally solidify after traveling a relatively short distance from the die . The resulting fibers are termed blown fibers and are generally substantially continuous. The fibers form a coherent network between the exit orifice of the die and a picking surface by the interlacing of the fibers due in part to the turbulence of the air stream to which the fibers were subjected.

For example, U.S. Patent No. 5,238,733 (Joseph et al.) Describes the formation of a multi-component meltblown microfiber network by feeding two separate flow streams from an organic polymeric material into a separate distribution device or into a tube. multiple combination. Divided or split streams are generally combined immediately before the die or die hole. Separate flow streams are preferably established as melt streams along closely parallel flow paths and combine when they are substantially parallel with each other and with the flow path of the combined multilayer resulting stream. Subsequently this multilayer flow is fed in a die and / or in the holes of a die and through the holes of the die. On each side of a row of die holes there are air slots which direct uniformly heated air at high speeds in the extruded multicomponent melt streams. The hot air at high speed extracts and attenuates the extruded polymeric material which solidifies after traveling a relatively short distance from the die. Single-layer microfibers can be manufactured in an analogous manner with air attenuation using a single extruder, without a dispensing device, and a single feed port die.

The solidified or partially solidified fibers form an interlacing network of interlaced fibers, which are collected as a coherent network. The picking surface may be a solid or perforated surface in the form of a flat surface or a drum, a moving band, or & a- .ffiff-Siáart¡r¿ ^ ítlt ^? & ^^ k ^ ^ S ^ &a.? Similary. If a perforated surface is used, the rear part of the collection surface can be exposed to vacuum or a low pressure region to assist with the deposition of the fibers. The collection distance is generally about 7 centimeters (cm) to about 130 cm from the face of the die. Moving the collector near the face of the die, for example, from about 7 cm to about 30 cm, will result in a stronger internal bond of the fibers and a network of lower height.

The temperature of the separated polymer flow streams is typically controlled to give the polymers substantially similar viscosities. When the separated polymer flow streams converge, they generally have to have an apparent melt viscosity (i.e., blow melt conditions) of about 150 poise to about 800 poise, as determined using a capillary rheometer. The relative viscosities of the separate flow streams that converge must generally coincide very closely.

The size of the polymer fibers formed depends to a greater extent on the speed and temperature of the attenuating air stream, on the diameter of the orifice, the temperature of the melt stream, and the total flow velocity per orifice. Typically, fibers having a diameter of no more than about 10 microns can be formed, although coarse fibers, for example, up to about 50 microns or more can be prepared using a melt blown process, and can be made up to 100 microns using a process of loop rotated. The networks formed can be of any thickness appropriate for the intended and intended end use. Generally, a thickness of about 0.01 cm to about 5 cm is appropriate for most applications.

The multicomponent fibers can be blended with other fibers in the backing such as other spin cast fibers, basic fibers, including inorganic and organic fibers, such as thermoplastic fibers, carbon fibers, glass fibers, mineral fibers, or organic ligature fibers. , as well as fibers of different polymers. The pressure-sensitive adhesive fibers of the present invention can also be mixed with particles, such as absorbent material in the form of particles, fumed silica, black carbon, glass beads, glass bubbles, clay particles, metal particles, and the like. Typically this is done before the fibers are collected by the incoming particles or other fibers in the air stream, which is then directed to intersect with the fiber streams. Alternatively, other polymeric materials can be melt processed simultaneously with multicomponent fibers of the present invention to form networks containing more than one type of melt processed fiber, preferably, blown microfiber. Networks having more than one type of fiber are referred to herein as having mixed constructions, the various types of fiber can be intimately mixed to form a substantially uniform cross section, or they can be in separate layers. The properties of the network can vary by the number of different fibers used, the number of layers or regions used, and the arrangement of the layer or region. Other materials such as surfactants or binders may also be incorporated into the network before, during, or after collection, for example by the use of a spray injector.

The adhesive component layer or region and the non-adhesive component layer or region are present in well-defined separate regions in a multi-component conjugated fiber. For example, layers or regions of multicomponent fiber may be in the form of two, or more overlays of fiber layers, in central arrangements Seath type, or fibers in concentric layers or structures of fiber layers type "island in the sea" " A component region would comprise the layer or region of the adhesive component and a second component region which would comprise the layer or region of non-adhesive material. Generally this region of adhesive fiber component will provide at least a portion of the exposed external surface of the multi-component conjugate fiber. Preferably, the individual components of the multicomponent conjugate fibers will be present substantially continuously along the length of the fiber in discrete areas, the zones of which preferably extend over the entire length of the fibers. Generally the individual fibers are of a fiber diameter of less than 100 microns, preferably less than 50 microns or 25 microns for the microfibers.

Alternatively, the conjugate multicomponent fibers can be formed by a spin loop process such as that described in US Patent No. 5,382,400 where separate polymer flow streams are fed via separate conduits to a spinneret to produce conjugate multicomponent fibers. Generally, these rows include an envelope containing a spinning pack with a stack of plates that form a pattern of apertures arranged to create flow patterns to separately direct the polymer components separated through the spinneret. The spinneret can be arranged to extrude the polymer vertically or horizontally in one or more rows of fibers.

An alternative arrangement for the formation of melt-blown multicomponent conjugate fibers is described, for example, in U.S. Patent No. 5,601,851. The polymer flow streams are fed separately into each individual die orifice by the use of grooves drawn in a distribution and / or separation plate. This arrangement can be used to separately extrude different polymers from different individual holes to provide well-defined separate fibers that form a coherent interlaced network having a substantially uniform distribution of the different fibers. By feeding two separate polymers to an individual die hole a multi-component conjugated fiber can be formed. The described apparatus is conveniently used in a blow-melt type arrangement where the holes of the dice are formed in a row along the die.

Figure 1 is an illustration of a nonwoven web 10 prepared from multilayer fibers 12 according to the present invention. Figure 2 is a cross-sectional view of a nonwoven web 10 of Figure 1 at a greater magnification showing a three-layer construction of the fibers 12. The multilayer fibers 12 each have three discrete layers of the polymeric material that they overlap There is a layer of an adhesive material, and two layers 15, 17 of a non-adhesive material. It is significant to note that the surface of the fibers have exposed edges of the layers of both materials. Then, the fibers, and therefore, the nonwoven webs of the present invention, can show properties associated with both types of materials simultaneously. Although Figure 1 illustrates a fiber having three layers of material, the fibers of the present invention may include two or many more layers, for example, hundreds of layers. Accordingly, the coherent fibers of the present invention can include, for example, only one type of adhesive material in one layer, two or more different types of adhesive compositions in two or more layers, forming layers with one or more material (s) Non-adhesive (s) in one or more layers. Each of the materials of the layers can be a mixture of different adhesive materials and / or non-adhesive materials.

The material of the adhesive component region preferably comprises a pressure sensitive adhesive capable of extrusion suitable for meltblowing (generally this requires that the adhesive have an apparent viscosity of 150 to 800 poise, under melt process conditions measured by capillary rheometer means) or other fiber spinning process such as in twisted loop processing. With the conjugate fibers of different polymers or mixtures formed from a single die or spinneret, the viscosities of the flow currents of the separated polymers should coincide very closely for the formation of a uniform fiber and network, but this is not a requirement. Generally the matching viscosities will ensure greater uniformity in the conjugate fibers formed in terms of minimization of polymer blending, which mixing can result in fiber breakage and grain formation (small particles of polymeric material), and low tensile properties. However, the presence of staple fibers or grains is not necessarily undesirable as long as the support of the nonwoven tape has the desired total strength.

The particular adhesive used in the formation of the conjugated discrete multicomponent fibers depends on the adhesive selected for the adhesive layer of the pressure sensitive tape and the material of the region of the non-adhesive component. The pressure sensitive adhesive generally selected is any copolymer that is hot extruded or composition having a melt viscosity appropriate for fiber formation by melt processing.

Suitable classes of pressure sensitive adhesives include polyacrylate adhesives, polyalphaolefin adhesives, polyvinyl acrylates, rubber resin adhesives of polydiorganosiloxane polyurea compolymers, blends or the like. Suitable rubber resin adhesives can include those formed by the use of a rubbery elastomer wherein a preferred elastomer is a type AB block copolymer wherein the A blocks and B blocks are configured in linear configurations (e.g. triple blocks of copolymer), radial or star. Block A is formed of a mono-alkenylarene, preferably a polystyrene block having a molecular weight between 4000 and 50,000, preferably between 7,000 and 30,000. The content of block A is preferably about 10 to 50 weight percent, preferably about 10 to 30 weight percent of the copolymer block. Other suitable A blocks can be formed from alpha-methylstyrene, tert-butyl styrene and other styrene alkylated rings, as well as mixtures thereof. Block B is formed of a conjugated elastomeric diene, generally polyisoprene, polybutadiene or its copolymers having an average molecular weight of from about 5,000 to about 500,000, preferably from about 50,000 to about 200,000. The dienes in block B may also be hydrogenated. The content of block B is generally 90 to 50 percent, preferably 90 to 70 percent by weight. The rubbery components of the elastomer-based adhesive generally comprise a solid resin and / or a liquid fatliquor or a plasticizer. Preferably, the weight-forming resins are selected from the group of resins at least partially compatible with the polydienes of the B-block portion of the elastomer. Although not preferred, generally a relatively small amount of the rosin resin may include resins compatible with the A block, which when present are generally referred to as terminal block reinforcing resins. Generally, terminal block resins are formed from aromatic monomer species. The liquid lubricants or plasticizers suitable for use in the adhesive composition include naphthenic oils, paraffinic oils, aromatic oils, mineral oils or esters of low molecular weight resins, polyterpenes and C-5 resins. Some suitable solid weight-bearing resins compatible with block B include C-5 resins, ester resins, polyterpenes and the like.

The bulk portion of the pressure sensitive adhesive generally comprises from 20 to 300 parts of the elastomer phase. Preferably, this is predominantly a solid pellet, however, from 0 to 25 weight percent, preferably from 0 to 10 weight percent of the adhesive composition may be a liquid pelletizer and / or plasticizer.

Suitable rubber resins for meltblowing processing is discussed in EP 658351 which exemplifies blown synthetic fibrous rubber resin adhesives used in a disposable absorbent article to immobilize absorbent in the form of particles or used as an aggregate of the sensitive adhesive. the pressure (for example, for a sanitary napkin). The appropriate adhesives that are exemplified are those based on the copolymer of the triple styrene-isoprene-styrene block, where the copolymer possesses bonding efficiencies in the range of 42 to 65 percent (for example, 58 to 35 percent of polystyrene-polyisoprene double block material could be present), plasticized with C-5 hydrocarbon resins (WINGTACK PLUS and WINGTACK 10 available from Goodyear) and stabilized with antioxidants.

Generally, depending on the fiber formation process, antioxidants and heat stabilizers can be used in the present invention to prevent degradation of the adhesive during the fiber-forming process or in its use. In addition, other conventional additives such as UV absorbers, pigments, particles, basic fibers or the like can be used.

Suitable poly (acrylates) are derived from: (A) at least one alkyl multifunctional (meta) acrylate monomer (i.e., alkyl acrylate and alkyl methacrylate monomer); and (B) at least one monofunctional free radical copolymerizable reinforcing monomer. The reinforcing monomer has a glass transition temperature of homopolymer (Tg) greater than that of the alkyl (meta) acrylate monomer and is one that increases the glass transition temperature and the modulus of the resulting copolymer. The monomers A and B are selected such that a copolymer formed therefrom is capable of being extruded and capable of forming fibers. Here, "copolymer" refers to polymers that contain two or more different monomers, including terpolymers, tetrapolymers, etc.

Preferably, the monomers used in the preparation of the pressure-sensitive adhesive copolymer fibers of the present invention include: (A) a monomer of (meta) alkyl acrylate which, when homopolymerized, generally has a glass transition temperature not greater than 0 ° C; and (B) a monofunctional free radical free copolymerizable reinforcing monomer which, when homopolymerized, generally has a glass transition temperature of at least about 10 ° C. The glass transition temperatures of the homopolymers of monomers A and B are typically accurate within ± 5 ° C and are measured by differential scanning calorimetry.

Monomer A, which is a monofunctional alkyl acrylate or methacrylate (i.e., (meta) acrylic acid ester), contributes to the flexibility and gumminity of the copolymer. Preferably, monomer A has a Tg of the homopolymer not greater than 0 ° C. Preferably, the alkyl group of the (meta) acrylate has an average of about 4 to about 20 carbon atoms, and more preferably, an average of about 4 to about 14 carbon atoms. The alkyl group may optionally contain oxygen atoms in the chain thereby forming ethers or alkoxy ethers. Examples of monomer A include, but are not limited to, 2-methylbutyl acrylate, isooctyl acrylate, lauryl acrylate, 4-methyl-2-pentyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-acrylate, butyl, n-hexyl acrylate, n-octyl acrylate, n-decyl acrylate, isodecyl acrylate, isodecyl methacrylate, and isononyl acrylate. Other examples include, but are not limited to, macromers (ie, macromolecular monomers) of poly-ethoxylated or -propoxylated methoxy (meta) acrylate (i.e., poly (ethylene oxide / propylene) mono- (meta) acrylate), macromers of polymethylvinyl ether mono (meta) acrylate, and ethoxylated or propoxylated nonylphenol acrylate macromers. The molecular weight of such macromers is typically from about 100 grams / mol to about 600 grams / mol, and preferably from about 30 grams / mol to about 600 grams / mol. Combinations of several monofunctional monomers categorized as a monomer A can be used to make use of the copolymer in the preparation of the present invention.

Monomer B, which is a monofunctional free radical copolymerizable reinforcing monomer, increases the vitreous transition temperature of the copolymer. The "reinforcing" monomers, as used herein, are those that increase the modulus of the adhesive, and therefore its strength. Preferably, monomer B possesses a Tg of the homopolymer less than 10 ° C. More preferably, monomer B is a monofunctional (meta) acrylic reinforcing monomer, including an acrylic acid, a methacrylic acid, an acrylamide, and an acrylate. Examples of monomer B include, but are not limited to, acrylamide, methacrylamide, N-methyl acrylamide, N-ethyl acrylamide, N-methylol acrylamide, N-hydroxyethyl acrylamide, diacetone acrylamide, N, N-dimethyl acrylamide, N, N -diethyl acrylamide, N-ethyl-N-aminomethyl acrylamide, N-ethyl-N-hydroxyethyl acrylamide, N, N-dimethylol acrylamide, N, N-dihydroxyethyl acrylamide, t-butyl acrylamide, dimethylaminoethyl acrylamide, N-octyl acrylamide, and 1,1,3,3-tetramethylbutyl acrylamide. Other examples of monomer B include acrylic acid and methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, 2-, 2- (diethoxy) ethyl acrylate, hydroxyethyl acrylate or methacrylate, 2-hydroxypropyl acrylate or methacrylate, methacrylate. of methyl, isobutyl acrylate, n-butyl methacrylate, isobornyl acrylate, 2- (phenoxy) ethyl acrylate, biphenylyl acrylate, t-butylphenyl acrylate, cyclohexyl acrylate, di-ethyladamantyl acrylate, 2-acrylate acrylate, -naphthyl, phenyl acrylate, N-vinyl pyrrolidone, and N-vinyl caprolactam. Various monofunctional reinforcing monomers categorized as a B monomer can be used to make use of the copolymer in the manufacture of the fibers of the present invention.

The acrylate copolymer is preferably formulated to obtain a resulting Tg less than about 25 ° C and more preferably less than about 0 ° C. Such acrylate copolymers include from about 60 parts to 98 parts per hundred of at least one alkyl (meta) acrylate monomer and from about 2 parts to about 40 parts per hundred of at least one copolymerizable reinforcing monomer. Preferably, the acrylate copolymers have from about 85 parts to 98 parts per hundred or at least one alkyl (meth) acrylate monomer and from about 2 parts to about 15 parts of at least one copolymerizable reinforcing monomer.

An agent for crosslinking can be used if it is desired to build the molecular weight and strength of the copolymer, and thereby improve the integrity and shape of the fibers. Preferably, the cross-linking agent is one that is copolymerized with monomers A and B. The cross-linking agent can produce cross-chemical bonds (eg, covalent bonds). Alternatively, it can produce physical cross-links, which result, for example, from the formation of reinforcement fields due to phase separation or acid-base interactions. In U.S. Patent Nos. 4,379,201 (Heilman); 4,737,559 (Kellen); 5,506,279 (Babu et al.); and 4,554,324 (Husman); Agents for cross-linking are described.

This crosslinking agent is preferably not activated in the direction of crosslinking until after the copolymer is extruded and the fibers are formed. Consequently, the crosslinking agent can be a crosslinking agent, which, upon exposure to ultraviolet radiation (for example, radiation having a wavelength of about 250 nanometers to about 400 nanometers) causes the cross-linking of the copolymer. However, preferably the agent provides a cross-link, typically, the physical cross-link, without further processing. The physical cross-link can take place through phase separation of domains that produce thermally reversible crosslinks. Therefore, acrylate copolymers prepared from a crosslinker that provides reversible physical crosslinks are particularly advantageous in the preparation of the fibers using the melt process.

Preferably, the crosslinking agent is (1) an acrylic cross linker monomer, or (2) a material for crosslinking polymeric having a copolymerizable vinyl group. Most often the crosslinking agent is a polymeric material having a copolymerizable vinyl group. Preferably, each of these monomers is a radical free polymerizable crosslinking agent capable of copolymerizing with monomers A and B. Combinations of various crosslinking agents can be used to make use of the copolymer in the manufacture of fibers of the present invention. It should be understood, however, that such cross-linking agents are optional.

The acrylic monomer for cross-linking is preferably one which is copolymerized with monomers A and B and generates free radicals in the central structure of the polymer by irradiation of the polymer. An example of such a monomer is an acrylated benzophenone as described in U.S. Patent No. 4,737,559 (Kellen et al.).

Polymeric materials for crosslinking having a copolymerizable vinyl group are preferably represented by the general formula X- (Y) n-Z wherein: X is a copolymerizable vinyl group; And it is a divalent linking group where n can be zero or one; and Z is a monovalent polymer portion having a Tg greater than about 20 ° C and an average molecular weight in the range of about 2,000 to about 30,000 and being essentially non-reactive under copolymerization conditions. Particularly the preferred vinyl terminated polymeric monomers useful in the manufacture of microfibers of the present invention are further defined as: a group X having the formula HR 1 C = CR 2 - wherein R 1 is a hydrogen atom or a group COOH and R 2 is a hydrogen atom or a methyl group; a group Z that has the formula -. { C (R3) (R4) - CH2} n-R5 wherein R3 is a hydrogen atom or a lower alkyl group (ie, C1-C4), R5 is a lower alkyl group, n is an integer from 20 to 500, and R4 is a monovalent radical selected from the group which consists of -C6H4R6 and -C02R7 wherein R6 is a hydrogen atom or a lower alkyl group and R7 is a lower alkyl group.

Sometimes, such vinyl terminated polymeric monomers for crosslinking are referred to as macromolecular monomers (i.e., "macromers"). Once polymerized with the (meta) acrylate monomer and the reinforcing monomer, a vinyl terminated polymeric monomer of this type forms a copolymer having polymeric portions that tend to reinforce the central acrylate structure that would otherwise be dim. , providing a substantial increase in the cut resistance of the resulting copolymer adhesive. Specific examples of such polymeric materials for crosslinking are described in U.S. Patent No. 4,554,324 (Husman et al.).

If used, the crosslinking agent is used in an effective amount, whereby an amount is understood to be sufficient to cause the crosslinking of the pressure sensitive adhesive to provide the final adhesion properties. Preferably, if the cross-linking agent is used, it is used in an amount of about 0.1 parts to about 10 parts, based on the same total amount of monomers.

If a cross-linked photo-linking agent is used, the adhesive in the form of fibers can be exposed to ultraviolet radiation with a wavelength of about 250 nm to about 400 nm. The radiant energy in this preferred wavelength range required for the crosslinking of the adhesive is about 100 milliJoules / centimeter2 (mJ / cm2) at about 1,500 mJ / cm2, and more preferably, about 200 mJ / cm2 at about 800 mJ / cm2.

The pressure sensitive acrylate adhesives of the present invention can be synthesized by a variety of free radical polymerization processes, including solution polymerization processes, radiation, mass, dispersion, emulsion, and suspension. Mass polymerization methods, such as the free radical polymerization method described in U.S. Patent Nos. 4,619,979 or 4,843,134 (both Kotnour et al.), The essentially adiabatic polymerization methods employing a batch reactor described in US Pat. 5,637,646 (Ellis), and the methods described for the polymerization of packaged pre-adhesive compositions described in International Patent Application No. WO 96/07522 can also be used to prepare the polymer used in the preparation of the fibers of the present invention. invention.

The pressure-sensitive acrylate adhesive compositions of the present invention may include conventional additives such as mangos (wood resins, polyesters, etc.), plasticizers, flow modifiers, neutralizing agents, stabilizers, antioxidants, fillers, colorants, and the like. , as long as they do not interfere with the fiber forming melt process. Initiators that are not copolymerizable with the monomers used to prepare the acrylate copolymer can also be used to improve the polymerization rate and / or the cross link. These additives are incorporated in amounts that do not materially adversely affect the desired properties of the pressure sensitive adhesives or their fiber-forming properties. Typically, they can be mixed in these systems in amounts of about 0.05 weight percent to about 25 weight percent, based on the total weight of the composition.

Suitable polyolefin adhesives could include gumming polyolefin elastomer-type adhesives, or amorphous polyalphaolefin polymers for the formation of hot-melt pressure-sensitive adhesives with or without the addition of shrinkage. Such amorphous polyalphaolefins are generally copolymers of linear (s) C3 to C5 alpha-olefin (s) and higher alpha-olefin (s) (generally from Cio to C). Copolymers are preferred of polyolefins with polyhexane, polyheptane, polyokene, polinonene, and / or polydecene. Such amorphous polyolefins are described in U.S. Patent Nos. 4,264,576; 3,954,697; and 4,072,812 wherein the amorphous polyalphaolefin copolymers can be used without the addition of the hinomants to directly form a pressure sensitive adhesive. These amorphous copolymers generally have from 40 to 60 mole percent of the major alpha olefin comonomer (s). However, suitable compatible gumming resins and plasticizing oils which generally correspond to those used to provide fatliquoring properties to the synthetic copolymer elastomers of the AB block described above can be used. For example, suitable compatible liquid or solid lubricants could include hydrocarbon resins, such as polyterpenes, C-5 hydrocarbon resins, or polyisoprenes. Esters of aromatic or aliphatic acids may also be suitable. If these hinomants are used in sufficient amounts, the highest alpha-olefin content can be as low as 15 mol percent and still suitable pressure sensitive adhesives can be formed.

Non-adhesive materials suitable for use in the formation of conjugated multicomponent fibers, for use in blends with the pressure sensitive adhesive, or for use as separate fibers, include polyolefins, polyesters, polyalkylenes, polyamides, polystyrenes, polyarylsulphones, polydienes, or polyurethanes. These materials are preferably extensible or slightly elastomeric, but could be elastomeric. Extendable or slightly elastomeric polyurethanes are preferred (eg, "MORTHANE" PS 440-200 resin available from Morton Thiokol Corp.); and polyolefins such as polyethylenes, polypropylenes, ethylene-propylene copolymers, ethylene / vinyl acetate copolymers, or metallocene-type polyethylenes with a density greater than 0.87 grams / cm 3. Other suitable elastomeric materials could include metallocene-type polyethylene copolymers (with bulk density less than 0.87 grams / cm 3); polyolefin elastomers (e.g., ethylene / propylene / diene elastomers); AB block copolymers, as described above, with A blocks formed of poly (vinyl) such as polystyrene and B blocks formed by conjugated dienes such as isoprene, butadiene or their hydrogenated versions (eg, "KRATON" elastomers available from Shell Chemical Co.); polyether esters (such as "ARNITAL", available from Akzo Plastics Co.); or polyether block amides (such as "PEBAX", available from Atochem Co.). Mixtures of elastomers, mixtures of nanoelastomers or mixtures of both elastomers and nanoelastomers can also be used for the pressure-sensitive adhesive fibers, conjugated fibers or in appropriate fiber blends.

Suitable polydiorganosiloxane polyurea copolymers which can be used in the preparation of the fibers, preferably microfibers, according to the present invention are the reaction products of at least one polyamine, wherein the polyamine comprises at least one polyamine (preferably diamine) ) of polydiorganosiloxane, or a mixture of at least one polyamine (preferably, diamine) of polydiorganosiloxane and at least one organic amine, with at least one polyisocyanate, wherein the mol ratio of the isocyanate and the amine is preferably in the range of about 0.9 : 1 to about 1.3: 1. That is, polydiorganosiloxane polyurea copolymers suitable for use in the preparation of fibers according to the present invention have soft polydiorganosiloxane units, hard units of polyisocyanate residue, and optionally, units of soft and / or hard organic polyamine residues. and terminal groups. The hard polyisocyanate residue and the polyamine hard residue comprise less than 50% by weight of the polydiorganosiloxane polyurea copolymer. The polyisocyanate residue is the polyisocyanate minus the -NCO groups and the polyamine residue is the polyamine minus the NH2 groups. The polyisocyanate residue is connected to the polyamine residue by the ligation of the urea. The end groups may be non-functional groups depending on the purpose of the polydiorganosiloxane polyurea copolymers. As used herein, the term "polydiorganosiloxane polyurea" encompasses materials having the repeating unit of Formula I and low molecular weight oligomeric materials having the structure of Formula II. Such compounds are suitable for use in the present invention if they can be processed by melting.

The polydiorganosiloxane polyurea copolymers used in the preparation of fibers of the present invention can be represented by the repeating unit: (i: wherein: each R is a portion that is independently an alkyl portion having preferably 1 to 12 carbon atoms and can be substituted, for example, with trifluoroalkyl or vinyl groups, a vinyl portion or an alkenyl portion greater preferably represented by the formula -R2 (CH2) aCH = CH2 wherein R2 is - (CH2) b- or - (CH2) CCH = CH- is already 1, 2, or 3; b is 0, 3, or 6; e is 3, 4, or 5, a cycloalkyl portion with 6 to 12 carbon atoms and can be substituted with alkyl, fluoroalkyl, and vinyl groups, or an aryl portion preferably having 6 to 20 carbon atoms and can be substituted, example, with alkyl, cycloalkyl, fluoroalkyl and vinyl groups or R is a perfluoroalkyl group as described in US Patent No. 5,028,679 (Terae et al.), a fluorine-containing group, as described in US Patent No. 5,236,997 ( Fijiki), or a group containing perfluoroether, as described in U.S. Patent Nos. 4,900,474 (Terae et al.) And 5,118,775 (Inomata et al.); preferably at least 50% of the portions of R are methyl portions with the remainder being monovalent alkyl or alkyl substituted with 1 to 12 carbon atoms, alkenylene portions, phenyl portions, or substituted phenyl portions; each Z is a polyvalent portion which is an arylene portion or an aralkylene portion preferably having from 6 to 20 carbon atoms, an alkylene or cycloalkylene portion preferably having from 6 to 20 carbon atoms, preferably Z is 2,6-tolylene, 4,4'-methylenediphenylene, 3, 3'-dimethoxy-4,4'-biphenylene, tetramethyl-2-ylkene, 4,4'-methyl-ethylcyclohexylene, 3,5,5-trimethyl-3-methylenecyclohexylene, 1,6- hexamethylene, 1,4-cyclohexylene, 2,2,4-trimethylhexylene and mixtures thereof; each Y is a polyvalent moiety which is independently an alkylene moiety having preferably from 1 to 10 carbon atoms, an aralkylene moiety or an arylene moiety preferably having from 6 to 20 carbon atoms; each D is independently selected from the group consisting of hydrogen, an alkyl portion of 1 to 10 carbon atoms, phenyl, and a portion that completes a ring structure including B or Y to form a heterocycle; B is a polyvalent portion selected from the group consisting of alkylene, aralkylene, cycloalkylene, phenylene, polyalkylene oxide, including for example, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, and copolymers and mixtures thereof; m is a number ranging from 0 to about 1000; n is a number that is equal to or greater than 1; Y p is a number that is about 5 or greater, preferably from about 15 to about 2000, more preferably from about 30 to about 1500.

By using polyisocyanates (Z is a portion having a functionality greater than 2) and polyamines (B is a portion having a functionality greater than 2), the structure of Formula I may be modified to reflect a branching in the central structure of the polymer. By using chain terminator agents, the structure of Formula I may be modified to reflect a chain termination of polydiorganosiloxane polyurea.

The segmented copolymers of lower molecular weight oligodrea polydiorganosiloxane provide a means for varying the modulus of elasticity of the compositions containing this component. They can serve to increase or decrease the modulus of the resulting composition, depending on the mono- and di-amines of polydiorganosiloxane used in the preparation of the oligourea polydiorganosiloxane segmented copolymer.

The segmented copolymers of lower molecular weight oligodrea polydiorganosiloxane can be represented by Formula II, as follows: (ID where: Z, Y, R and D have been previously described; each X is a monovalent portion which is not reactive under conditions of moisture curing or free radicals and which independently is an alkyl portion preferably having from about 1 to about 12 carbon atoms and which can be substituted, for example, with groups trifluoroalkyl or vinyl or an aryl portion preferably having from about 6 to about 20 carbon atoms and which can be substituted, for example, with alkyl, cycloalkyl, fluoroalkyl and vinyl groups; q is a number of about 5 to about 2000.or greater; r is a number from about 1 to about 2000 or greater; and t is a number up to 8.

These lower molecular weight polydiorganosiloxane oligourea copolymers can be used alone or in combination with the higher molecular weight polydiorganosiloxane polyurea copolymers (eg, wherein n in Formula I is greater than 8). For example, the higher molecular weight polydiorganosiloxane polyurea copolymers can be arranged in the form of layers with these segmented copolymers of lower molecular weight polydiorganosiloxane oligourea. Alternatively, higher molecular weight polydiorganosiloxane polyurea copolymers can optionally be blended with a lower molecular weight polydiorganosiloxane oligourea copolymer * which, when present, is preferred to be present in an amount of about 5 parts to about 50 parts. for 100 total parts of the composition. If the lower molecular weight polydiorganosiloxane oligourea copolymers are used alone, they will need to be cured (eg, UV cured) substantially immediately upon formation of the fibers (eg, substantially immediately upon formation of the network and before the network is formed). be rolled up for storage) to maintain sufficient fiber integrity.

The polydiorganosiloxane polyurea copolymers can be processed, stored and subsequently extruded into fibers. If the produced polymer does not have pressure-sensitive adhesive properties, it can optionally be co-extruded with a shrinkage during the fiber-forming melt process. Alternatively, the polymers can be prepared in-situ (for example, in an extruder), with or without pressure-sensitive adhesive properties, and the fibers immediately formed.

Preferably, the polydiorganosiloxane polyurea copolymers can be made by processes known in the art based on solvent, by processes that do not use solvents or by a combination of the two. In the art, solvent-based processes are well known. Examples of solvent-based processes by which the polydiorganosiloxane polyurea copolymer useful in the present invention can be prepared include: Tyagi et al .: "Segmented Organosiloxane Copolymers: 2. Thermal and Mechanical Properties of Siloxane Urea Coplymers (Segmented Organosiloxane Copolymers: 2. Thermal and Mechanical Properties of Urea Siloxane Copolymers), Polymer, Vol. 25, December, 1984 and US Patent No. 5,214,119 (Leir et al.).

Polymeric polydiorganosiloxane polyurea copolymer, generally silicate resins, may be added to the polymer to provide or improve the pressure sensitive adhesive properties of the polymer. As used herein, a pressure sensitive adhesive has a fourfold balance of adhesion, cohesion, expansion, and elasticity, and a glass transition temperature (Tg) of less than about 20 ° C. In this way, they are gummy to the touch at room temperature (for example, from about 20 ° C to about 25 ° C), when determined by a finger-test or by conventional measuring devices, and can easily form a bond Useful adhesive with the application of slight pressure.

The silicate resin can play an important role in determining the physical properties of the polydiorganosiloxane polyurea copolymer of the present invention. For example, when the silicate resin content is increased from a low to a high concentration, a transition from a glassy to rubbery state of the polydiorganosiloxane polyurea copolymer occurs when increasing at higher temperatures. A need that is not limited to a single silicate resin when it may be beneficial to employ a combination of resins in a single composition to achieve the desired performance.

The silicate resins useful in the present invention include those resins composed of the following structural units M, D, T, and Q, and combinations thereof. Typical examples include silicate and MQ resins, silicate and MQD resins, and silicate and MQT resins which may also be referred to as copolymer silicate resins and which preferably have an average molecular weight number of about 100 to about 50,000, with greater preference of about 500 to about 10,000 and generally have methyl substituents. The silicate resins also include both non-functional and functional resins, the functional resins having one or more functionalities including, for example, silicon-bonded hydrogen, silicon-bonded alkenyl, and silanol. The silicate and MQ resins are copolymer silicate resins having R'3SiO? / 2 units and Si04 / 2 units. Such resins are described, for example in the Encyclopedia of Polymer Science and Engineering (Encyclopedia of Polymer Science and Engineering), vol. 15, John Wiley & Sons, New York (1989), pages 265-270, and in U.S. Patent Nos. 2,676,182 (Daudt et al.); 3,627,851 (Brady); 3,772,247 (Flannigan); and 5,248,739 (Schmidt et al.). Silicate and MQ resins having functional groups are described in US Patent No. 4,774,310 (Butler) having silyl hydride groups; in U.S. Patent No. 5,262,558 (Kobayashi et al.) having vinyl and trifluoropropyl groups, and in U.S. Patent No. 4,707,531 (Shirata) having silyl and vinyl hydride groups. The resins described above are generally prepared in solvent. Silicate and MQ resins can be prepared dry or without solvent, as described in U.S. Patent Nos. 5,319,040 (Wengrovius et al.); 5,302,685 (Tsumura et al.); and 4,935,484 (Wolfgruber et al.). The silicate and MQD resins are terpolymers having R '3Si0? / 2 units, Si04 / 2 units, and R'2Si02 / 2 units as shown in U.S. Patent No. 2,736,721 (Dexter). Silicate and MQT resins are terpolymers having R'3SiO? / 2 units, Si04 / 2 units, and R'Si03 / 2 units as shown in U.S. Patent No. 5,110,890 (Butler) and in Japanese Kokai HE 2-36234.

Commercially available silicate resins include SR-545, MQ resin in toluene, available from General Electric Co., Silicone Resins Division, Waterford, N.Y .; MQOH resins which are MQ resins available from PCR, Inc. Ga sville FL; MQR-32-1, MQR-32-2, and MQR-32-3 which are MQD resins in toluene, available from Shini-Etsu Silicones of America, Inc., Torrance, CA and PC-403 a hydride-functional MQ resin in toluene available from Rhone-Poulenc, Latex and Specialty Polymers, Rock Hill, SC. Such resins are generally supplied in organic solvent and can be employed as received in compositions of the present invention. However, these organic silicate resin solutions can also be dried by numerous techniques known in the art, such as spray drying, oven drying and the like, or vapor separation to provide a silicate resin with substantially 100% non-volatile content. for use in compositions of the present invention. Also useful in the polydiorganosiloxane polyurea copolymers of the present invention are mixtures of two or more silicate resins. In addition to or in place of the silicate resins, organic body lotions may be used.

When a thickening material is included with the polydiorganosiloxane polyurea copolymer, that component preferably contains from about 1 to about 80 parts by weight of the fatliquoring material and more preferably from about 15 to 75 parts by weight of the fatliquoring material. The total parts by weight of the polydiorganosiloxane polyurea copolymer and the silicate resin in the combination is equal to 100. The optimum amount of the fatliquor depends on such factors as well as the type and amount of reactants used, the molecular weight of the hard segments and soft of polydiorganosiloxane and polyurea segmented copolymer, and the intended use for the composition of the invention.

Fillers, fillers, and other property modifiers, such as flow modifiers, dyes, pigments, flame retardants, stabilizers, antioxidants, compatibilizers, agents, may be incorporated into the composition of the pressure sensitive adhesive. • - »». { ü, jgíliV, ¡'^^ - ^^^ - Ü --MÍt¿m4rWwM-. antimicrobials, electrical conductors, and thermal conductors, as long as they do not interfere in the melting process of fiber formation or do not affect to the detriment of the function and functionality of the final product polymer. These additives can be mixed within these systems in amounts of about 1 volume percent to about 50 volume percent of the composition of the invention.

The material of the region of the adhesive component generally comprises from 1 to 60 percent of the weight base of the nonwoven support, preferably from 15 to 40 percent.

The nonwoven support will generally have a basis weight of 25 to 200 g / m2, preferably of the multicomponent fibers alone; however, the basis weight could be significantly higher with added particles and / or fibers.

Mixed fibers of other types may be incorporated within the tape carrier therefrom from the same as in US Patent No. 5,601,851 above, or in separate dies that could lead to the other fibers directly, or subsequently, within the current of fiber containing multi-component adhesive fibers before harvesting any fiber on the collection surface. In the art it is known to use multiple dice for the formation of fiber mixtures. Additional networks of mixed fibers could be formed by the addition of discrete basic fibers as is known in the art.

The layer of pressure-sensitive adhesive tape can be continuous or intermittent and applied outside a solvent or a molten phase, however an intermittent adhesive cover or otherwise capable of allowing breathing is preferred. Intermittent coverage is described in US Pat. Nos. 5,595,001 (Potter); US 5,613,942; EP 353,972; and EP 91800. Preferably the layer of pressure-sensitive adhesive tape is applied from the molten phase and a particularly preferred adhesive is a non-woven fibrous adhesive which can be formed by a blow-melt process or a twisted-loop process as the preferred nonwoven tape carriers wherein the layer of adhesive tape has a basis weight of 15 to 125 g / m2. The pressure-sensitive fibrous adhesive material may be a single fibrous component, or fibers, multicomponent fiber (s) or fibers formed from blends or combinations thereof. With multicomponent fibers, blended fibers, or blended fibers, the other material components can be other pressure sensitive adhesive materials or non-pressure sensitive adhesive materials. The other materials are generally intimately mixed with the pressure sensitive adhesive fibers or fiber layers. The mixed pressure sensitive adhesive fibers or microfibers and other adhesive or non-pressure sensitive adhesive fibrous material may be present in individual separated fibers or pressure sensitive adhesive fibers or microfibers and the other adhesive or material not sensitive to pressure they can form different regions in a conjugated fiber and / or can be part of a mixture. For example, the conjugated fibers may be in the form of two or more layers of fibers on layings, such as central Seath-type fibers or in arrays of concentric layers or in "island-in-the-sea" fiber structures. In this case, a component region could comprise the fiber or pressure-sensitive adhesive microfiber. Generally, the pressure-sensitive adhesive fiber component with any form of multi-component conjugate fibers will provide at least a portion of the exposed outer surface of the multicomponent conjugate fiber. Preferably, the individual components of the multicomponent conjugate fibers will be present substantially continuously along the length in discrete areas, the zones of which preferably extend over the entire length of the fibers. Generally the individual fibers are of a fiber diameter of less than 100 microns, preferably less than 50 microns or 25 microns for the microfibers.

The fibers of the fibrous layer of pressure-sensitive adhesive tape can be formed by the meltblowing or spin loop processes described above for the formation of the support and can be formed of a similar pressure sensitive adhesive described above with other adhesives. and / or non-adhesive. These fibers of the pressure-sensitive adhesive tape layer may be formed in a separate step or sequentially with the formation of the support as described in US Pat. Nos. 4,655,757 or 4,778,460, of which the substance is incorporated by reference . The pressure-sensitive adhesive component of a fibrous layer of pressure-sensitive non-woven adhesive tape generally comprises from 100 to 50 percent of the basis weight of the fibers in the network of the fibrous layer of pressure sensitive adhesive tape, preferably from 85 to 100 percent. If the adhesive non-pressure sensitive fibrous material is present, and only in the form of a mixture with the pressure-sensitive adhesive material, it is preferably from 0 to 40 percent of the basis weight of the fibers forming the layer of tape. Pressure sensitive adhesive. The use of non-pressure sensitive adhesive material with the pressure-sensitive adhesive material decreases adhesion, however, it can also increase breathing capacity. Where the non-pressure sensitive adhesive fibrous material is present as a discrete fiber, these fibers are generally intimately mixed with the pressure sensitive adhesive fibers. If the non-pressure sensitive fibrous component is present as mixed fibers, these fibers can be formed from the same as in US Patent No. 5,601,851 as described above or in a separate die which could directly direct the non-sensitive adhesive fibers. to the pressure, or subsequently, within the fiber stream containing the pressure sensitive adhesive fibers prior to the collection of any fiber on a collection surface. In the art it is known to use multiple dies for the formation of mixed fibers. Additional blended fibers can be added as discrete basic fibers as is known in the art. Generally, the layer of pressure-sensitive adhesive tape has a basis weight of 5 to 200 g / cm2, preferably 20 to 100 g / cm2.

The support of the nonwoven tape of the invention is extremely capable of allowing respiration having generally a wet steam transmission ratio (MVTR) greater than 500 gm / m2 / 24 hrs, preferably greater than 2,000 gm / m2 / 24 hrs. The regions of the adhesive component of the multi-component fiber support have a nominal effect on the total stress properties of the support as the bonding of the layer of pressure-sensitive adhesive tape to the support increases. Generally, the tape could be used with a separable cover (e.g., as a tape bandage) However, a separable cover or treatment on the surface of the support can be used without the provision of a layer of pressure-sensitive adhesive tape to allow roll-up of the tape. However, this detracts from the tape's ability to cover and stick to the tape (the ability to bond with itself). It has unexpectedly been found that tapes made with the support of the invention can adhere to themselves (cover and paste) without transferring the pressure-sensitive adhesive region of the original face with adhesive cover to the opposite side of non-adhesive cover, particularly if the support is compressed (for example, by a fold that may or may not have a gap, the separation of which is less than the thickness of the support and may be under a different applied pressure to the same folds of the rolls) during or after the to formation of the tape.

EXAMPLES The following examples are offered to help understand the present invention and should not be construed as limiting its scope. All parts and percentages are by weight, unless otherwise indicated.

TEST PROTOCOLS The following test methods were used in the examples for evaluation purposes: Stress Resistance: ASTM Method No. D3759-83 using a sample width of 2.5 cm, a thickness length of 2.5 cm, and a crosshead speed of 25 cm / min. The maximum force applied to the test sample is reported to obtain the stress value at the fracture point.

Rupture Point Elongation: ASTM Method No. D3759-83 using a sample width of 2.5 cm, a thickness length of 2.5 cm, and a crosshead speed of 25 cm / min. The maximum percent of the stretch reached by the test sample at the point of rupture is reported.

Porosity: Evaluated by a procedure that determines the time (in seconds) necessary for an inner cylinder of a Gurley densometer to force the entry of 100 cc of air through a circular sample of 25 mm of the fabric, of a analogous to that described in ASTM D737-75 method.

MVTR: Humid Vapor Transmission Rate evaluated in a manner analogous to that described in the ASTM E 96-80 method at 40 ° C and expressed in grams transmitted per square meter per day.

SAMPLES OF NON-WOVEN ADHESIVE NETWORK Adhesive Sample 1 A pressure sensitive adhesive network (PSA) of blown microfiber (BMF) based on rubberized KRATON ™ was prepared using a blow molding process similar to that described, for example, in Wente, Van A., "Superfine Thermoplastic Fibers (Superfine Thermoplastic Fibers) ", in Industrial Engineering Chemistry, Vol. 48, pages 1342 and following (1956) or in Report No. 4364 of the Navel Research Laboratories, published on May 25, 1954, entitled" Manufacture of Superfine Organic Fibers (Manufacturing of Superfine Organic Fibers) ", by Wente, Van A .; Boone C.D .; and Fluharty, E.L., except that the BMF apparatus used a single extruder that fed its molten stream to a gear pump that controlled the flow of molten polymer. The gear pump fed the assembly of a feed block connected to a die-cast die with circular holes of smooth surface (10 / cm) with a length-to-diameter ratio of 5: 1. The primary air was maintained at 220 ° C and 241 KPa with a separation width of 0.076 cm to produce a uniform network. The feed block was fed with a stream of molten polymer (190 ° C) comprised of a precomposed mixture of KRATON ™ 1112 (100 parts, a styrene / isoprene / styrene block copolymer (a mixture of double block copolymer and triple block ) available from Shell Chemical, Houston, TX), ESCOREZ ™ 1310LC (80 parts, an aliphatic hydrocarbon component available from Exxon Chemical Co., Houston, TX) and ZONAREZ ™ A25 (10 parts, an alpha pinene type resin available from Arizona) Chemical, Panama City, FL). Both the die and the assembly of the feed block were maintained at 180 ° C, and the die was operated at a rate of 178 g / hr / cm of die width. The BMF-PSA network was collected on a separable double-coated silicone paper (Daubert Coated Products, Westchester, IL) which passed around a rotating drum at a collector distance to the 20.3 cm die. The resulting BMF-PSA network had a basis weight of approximately 50 g / m2.

Adhesive Sample 2 A rubbery non-woven BMF-PSA network based on polyacrylate was prepared using a blow molding process similar to that described in Adhesive Sample 1, except that the assembly of the feed block was fed with a stream of molten polymer (190 ° C). ) composed of a precomposed mixture of an isooctyl acrylate / acrylic acid / styrene macromer polymer (92/4/4) (100 parts) and ESCOREZ ™ 2393 (30 parts, an available hydrocarbon from Exxon Chemical Co.). The primary air was maintained at 223 ° C and 103 KPa with a separation width of 0.076 cm to produce a uniform network. Both the die and the assembly of the feed block were maintained at 200 ° C, and the die was operated at a rate of 178 g / hr / cm of die width. The resulting BMF-PSA network had a basis weight of approximately 55 g / m2.

Adhesive Sample 3 A network of polyacrylate-based nonwoven BMF-PSA was prepared using a blow-melt process similar to that described in Adhesive Sample 1, except that the assembly of the feed block was fed with a stream of molten polymer (220 ° C) composed of an isooctyl acrylate / acrylic acid / styrene macromer (92/4/4). The primary air was maintained at 223 ° C and 103 KPa with a separation width of 0.076 cm to produce a uniform network. Both the die and the assembly of the feeding die were maintained at 200 ° C, and the die was operated at a rate of 178 g / hr / cm of die width. The resulting BMF-PSA network had a basis weight of approximately 55g / m2.

SAMPLES OF NON-WOVEN TAPE SUPPORTS Sample of Support 1 A nonwoven BMF network was prepared from PS 440-200 polyurethane resin (Morton Thiokol Corp., Seabrook, NH) as described in U.S. Patent No. 5,230,701 (Meyer, et al.), Which is incorporated herein by reference. reference. The resin was melted at 225 ° C and the die distance to the collector was 15.2 cm. The resulting network of BMF had a basis weight of approximately 100 g / m2.

Sample of Support 2 A BMF network was prepared as described in Support Sample 1, except that the PS 440-200 polyurethane resin was blended little by little with 4% of a tan pigment (composed of the polyurethane premix (80%) / pigment (20%) available as Product No. 1093538 TAN from Reed Spectrum, Minneapolis, MN). The resulting BMF network had a basis weight of approximately 104 g / m2.

Support Sample 3 A network of BMF-PSA composed of three layers of polymer fibers was prepared using a blow-melt process similar to that described in Adhesive Sample 1, except that the BMF apparatus used two extruders, each of which fed its extrudates to a gear pump that controlled the flow of molten polymer. The gear pumps fed a three-layer feedblock assembly (fractionator) similar to that described in U.S. Patent Nos. 3,480,502 (Chisholm, et al.) And 3,487,505 (Schrenk), which are incorporated herein by reference. The feed block assembly was connected to a casting blow die with smooth circular surface holes (10 / cm) with a length to diameter ratio of 5: 1. The primary air was maintained at 240 ° C and 241 KPa with 0.076 cm of separation to produce a uniform network. Both the die and the assembly of the feed block were maintained at 240 °, and the die was operated at a rate of 178 g / hr / cm of die width.

The feed block was fed by two streams of molten polymer, one of them being a molten stream of rubbery KRATON ™ 1112 (as described in Adhesive Sample 1, hereinafter referred to as "KRATON" PSA) at 180 ° C. , and the other being a molten stream of PS 440-200 polyurethane resin at 225 ° C. The gear pumps were adjusted to produce a ratio of 5/95"KRATON" PSA to polyurethane resin (based on a percent ratio of the pump), and the BMF-PSA network was collected on a separable paper. of double-coated silicone (Daubert Coated Products, Westchester, IL) that passed around a rotary collector drum at a distance from the collector to the 15.2 cm die. The feed block divided the molten streams and recombined them in an alternating fashion within a three layer melt stream at the outlet of the feed block assembly, with the outermost layers of the outgoing stream being the adhesives. The resulting BMF-PSA network had a basis weight of approximately 100 g / m2.

Support Example 4 A network of BMF-PSA of three-layer polymer fibers was prepared as described in Support Sample 3, except that the ratio of "KRATON" PSA to polyurethane resin was 10/90. The resulting BMF-PSA network had a basis weight of approximately 100g / m2.

Examples of Supports 5-7 Networks of BMF-PSA composed of three-layer polymer fibers wprepared as described in Support Sample 3, except that the polyurethane resin 440-200 contained 4% of the tan pigment and the resin ratio "KRATON" PSA to polyurethane / pigment was 20/80. The resulting BMF-PSA networks had basis weights of approximately 120g / m2 (sample 5), 100 g / m2 (Sample 6), and 75 g / m2 (Sample 7).

Support Samples 8-10 Networks of BMF-PSA composed of three-layer polymer fibers wprepared as described in the Sample of Supports 5-7, except that the ratio of resin "KRATON" PSA to polyurethane / pigment was 30/70. The resulting BMF-PSA networks had basis weights of approximately 125 g / m2 (Sample 8), 100 g / m2 (Sample 9), and 75 g / m2 (Sample 10).

Support samples 11-13 Networks of BMF-PSA composed of three-layer polymeric fibers wprepared as described in Sample of Supports 5-7, except that the ratio of resin "KRATON" PSA to polyurethane / pigment was 40/60. The resulting BMF-PSA networks had basis weights of approximately 125 g / m2 (Sample 11), 100 g / m2 (Sample 12), and 75 g / m2 (Sample 13).

Sample of Support 14 A BMF-PSA network composed of double layer polymer fibers was prepared using a blow molding process similar to that described in Support Sample 3, except that a double layer feed block assembly replaced the feed block assembly of three layers.

The feed block was fed by two streams of molten polymers, one of them being a molten stream of "KRATON" PSA at 180 ° C, and the other stream being melted from polyurethane resin PS 440-200 at 225 ° C. The gear pumps wadjusted to produce a 10/90 ratio of "KRATON" PSA to polyurethane and BMF-PSA network was collected on separable silicone paper as described in Support Sample 3. The power block assembly divided the currents and recombined them into a double-layer molten stream at the outlet of the feed block assembly. The resulting BMF-PSA network had a basis weight of approximately 111 g / m2.

Support Sample 15 A BMF-PSA network composed of double layer polymer fibers was prepared as described in the Sample of Support 14, except that the ratio of resin "KRATON" PSA to polyurethane / pigment was 20/80. The resulting BMF-PSA network had a basis weight of approximately 122 g / m2.

Sample of Support 16 A network of BMF-PSA composed of three-layer polymer fibers was prepared as described in Support Sample 3, except for the following. The feed block was connected to the die-cast die with smooth surface circular holes (10 / cm) with a ratio of 5: 1 in length to diameter. The primary air was maintained at 238 ° C and 193KPa with 0.076 cm wide separation to produce a uniform network. Both the die and the assembly of the feed block wmaintained at 225 ° C, and the die was operated at a rate of 178 g / hr / cm of die width.

The feed block was fed by two molten polymer streams, one of them being a molten stream composed of a 50/50 (by weight) mixture of m-PE (a metallocene-polyethylene available from Exxon Chemical Co.) and " KRATON "PSA at 220 ° C, and the other being a molten stream of polyurethane resin PS 440-200 at 220 ° C. The gear pumps wadjusted to produce a 20/80 ratio of "KRATON" PSA / polyethylene blend to polyurethane resin (based on a percent ratio of the pump), and the resulting BMF-PSA network was collected at a separable double-coated silicone paper which passed around the collection drum at a distance from the manifold to the 16.5 cm die. The power block assembly divided the molten streams and recombined them in an alternating fashion into a three layer melt stream at the outlet of the feedblock assembly, with the outermost layers of the output stream being the polyurethane. The resulting net had a basis weight of approximately 105 g / m2.

Support Samples Evaluations The samples of Support BMF 2 and 5-15 were evaluated (Machine Direction) with the tests of Resistance to Tension and% of Elongation in the Rupture. The results are presented in Table 1.

The samples of BMF Supports 2, 14 and 15 were compared in evaluations for the tensile-elongation properties in the machine direction, porosity in a Gurly Instrument, and Wet Steam Transmission Velocities (MVTR). The results are shown in Table 2 and show that the Substrate Samples containing adhesive 14 and 15 are highly porous, possess good "breathing capacity" (ie, high MVTR values), and have acceptable mechanical properties, based on in the tension-elongation values, such as Sample Support 2, which does not contain adhesive.

The samples of BMF Supports 2, 14, and 15 were compared in peel force evaluations according to the "Peel Force" test as described in US Patent No. 5,531,855 (Heinecke, et al.), Which is Incorporates here as a reference. Next, the Support Samples were attached to a glass surface using a double glue tape on an IMASS Release Test Apparatus (Model No. SP-102C-3M90, manufactured by Imass Inc., Accord, MA). Subsequently, strips (1.74 cm wide) of Removable Magic Tape No. 811 SCOTCH ™ (3M Company, St. Paul, MN) were adhered to the Support Samples by passing twice (2 passes) a 2 kg roll over the tapes. The tape bands were detached from the surfaces of the support samples (which were firmly attached to the glass surface) at a speed of approximately 76 cm / minute. The release force values listed below clearly show that the addition of a small amount of PSA in the polyurethane / pigment BMF nonwoven backing greatly improves the adhesion strength of the backing to another adhesive surface. These results suggest that the PSA layers in the microfibers act as a "base adhesive" in the network and thus can increase both double bonds (the bonding of the adhesive tape layer with the non-woven backing) and the properties of covering and gluing (bonding the adhesive layer with the non-adhesive coated side of the support).

Sample of Support Release Force (g / l.74 cm) 2 (control) 19 14 47 15 67 EXAMPLE 1 The Non-woven Support Sample 3 (BMF network composed of 3-layer fibers containing 95% polyurethane and 5% "KRATON" PSA) was laminated to the sample Adhesive 1 (BMF "KRATON" PSA network) using a laminator laboratory with two rubber rollers with the temperature of the lower roller set at 154 ° C and the temperature of the upper roller initially set at room temperature. The resulting adhesive tape was evaluated for adhesion to the glass and stainless steel surfaces as described below.

EXAMPLE 2 The non-woven Support 4 sample (BMF network composed of 3-layer fibers containing 90% polyurethane and 10% "KRATON" PSA) was laminated to Adhesive Sample 1 (BMF "KRATON" PSA network) as described in Example 1. The resulting adhesive tape was evaluated for adhesion to the glass and stainless steel surfaces as described below.

EXAMPLE 3 The non-woven Support 16 sample (BMF network composed of three-layer fibers containing 80% polyurethane and 20% "KRATON" PSA / polyethylene blend) was laminated to the Adhesive Sample 2 (PSA polyacrylate BMF network) using a conventional calender operation with a heated stainless steel roller (230 ° C) and a rubber roller (110 ° C), using a separation of 6 mils. The resulting adhesive tape had a basis weight of approximately 160 g / m2 and was evaluated for adhesion in stainless steel, tensile strength, elongation at break, and porosity, as described below.

EXAMPLE 4 The non-woven Support Sample 16 (BMF network composed of three-layer fibers containing 80% polyurethane and 20% "KRATON" PSA / polyethylene mixture) was laminated to Adhesive Sample 3 (polyacrylate PSA rubbery BMF network) ) as described in Example 3. The resulting adhesive tape had a basis weight of approximately 160 g / m2.

Comparative Example 1 The Nonwoven Support 1 sample (polyurethane BMF network) was laminated to the Adhesive Sample 1 (BMF network of "KRATON" PSA) as described in Example 1 to provide a Comparative Example of adhesive tape containing no Adhesive added to the support.

Comparative Example 2 The nonwoven Support Sample 2 (polyurethane BMF web) was laminated to the Adhesive Sample 2 as described in Example 1. The resulting adhesive tape was evaluated for adhesion to the supports as described below.

Comparative Example 3 The nonwoven Support Sample 2 (polyurethane BMF web) was laminated to the Adhesive Sample 3 as described in Example 1. The resulting adhesive tape was evaluated for adhesion to the supports as described below.

EVALUATIONS OF ADHESIVE TAPES Adhesion to Glass The adhesive tape samples of Example 1, Example 2, and Comparative Example 1 were cut into 2.54 cm x 7.62 cm samples and then adhered to a glass surface by passing a roller of 2 kg twice over the tapes ( that is, two passes). After resting for four hours the tapes were detached from the glass slowly by hand at a speed of approximately 15 cm / minute. It was noted that the tape made of Comparative Example 1 (polyurethane support without adhesive content) left a coarse residue of adhesive on the surface of the glass, while the two tapes made of Example 1 (polyurethane support containing 5% adhesive) and of Example 2 (polyurethane support containing 10%) % adhesive) did not leave any residue.

Adhesion to stainless steel The procedure described above was repeated for the tape samples of Example 1, Example 2, Example 3, and Comparative Example 1, except that a stainless steel surface was used instead of the glass surface. It was noted that the tape made from Comparative Example 1 left a coarse residue of adhesive on the stainless steel surface, while the three tapes made from Example 1, Example 2, or Example 3, left no residue. The adhesion strength was measured for the adhesive tapes of Example 3, it being found that this was 1162 g / 2.5 cm.

The results of these evaluations of glass adhesion and adhesion to stainless steel suggest that the incorporation of a small amount of adhesive into the polyurethane BMF network backing significantly improves the double bond strength of the resulting ribbon laminate, and could also be expected. the improvement of the performance of covering and pasting of the tape.

Adhesion to Support Support Samples 2 and 16 were compared in the release force evaluations of the "Release Force" test as described in U.S. Patent No. 5,531,855 (Heinecke, et al.), Which is incorporated herein. as reference. Next, the two Support Samples were glued to a glass surface using a double-stick tape and placed in an IMASS Release Test apparatus (Model No. SP-102C-3M90, manufactured by Imass Inc., Accord, MA). Subsequently, strips (1.27 cm wide) of adhesive tape samples of Comparative Example 2 and Comparative Example 3 were adhered to the Support Samples by passing twice (i.e., two passes) a 2 kg roll over the tapes. The tape bands were detached from the surface of the support samples (which were firmly glued to the glass surface) at a rate of approximately 76 cm / min. The release values listed below show that the addition of a small amount of pressure sensitive adhesive component in the pigmented polyurethane BMF nonwoven backing greatly improves the adhesion strength of the backing on another adhesive surface.

Samples Sample Strength Detach Adhesive Supports (g / 2.54 cm) 2 Comparative Example 3 86 16 Comparative Example 3 94 2 Comparative Example 2 134 16 Comparative Example 2 219 Tensile Strength The tensile strength (machine direction) was measured for the adhesive tape of Example 3 and it was found to be 3005 g / 2.5 cm.

Enlightenment at Rupture The percent elongation at the break was measured for the adhesive tape of Example 3 and found to be 451%.

Porosity The porosity was measured for the adhesive tape of Example 3 and found to be 1.3 seconds.

MVTR The MVTR was measured for the adhesive tape of Example 3 and found to be 6166 g / m / 24 hr.

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.

Having described the invention as above, the content of the following is claimed as property.

Claims (2)

1. A substrate coated with pressure-sensitive adhesive, characterized in that it comprises a substrate of a nonwoven tape carrier composed of multi-component conjugate fibers each of said multicomponent fibers having two or more separate component regions with at least one region of adhesive component forming at least a portion of the outer surface of the multi-component fibers and at least one non-adhesive component region with the multi-component conjugate fibers distributed throughout the width dimension of the substrate of the non-woven tape so that the region of adhesive component, in a multiplicity of such multicomponent fibers, is exposed on both outer surfaces of the non-woven substrate substrate, and a layer of pressure-sensitive adhesive tape coated on at least one side of the non-woven substrate substrate whose tape layer Pressure-sensitive adhesive has improved adhesive properties ace of the adhesive component region.
2. 2. The pressure sensitive adhesive coated substrate according to claim 1, characterized in that the layer of pressure sensitive tape is capable of allowing respiration. The pressure sensitive adhesive coated substrate according to claim 1, characterized in that the multi-component fibers are melt blown or twisted loop and the adhesive component region is a region of pressure sensitive adhesive component. The pressure sensitive adhesive coated substrate according to claim 1, characterized in that the pressure-sensitive adhesive component region has improved adhesion properties of the pressure-sensitive adhesive tape layer compared to the non-component component region. adhesive. The pressure sensitive adhesive coated substrate according to any of claims 1-4, characterized in that the material of the region of the pressure sensitive adhesive component comprises from 1 to 60 weight percent of the nonwoven substrate substrate. The substrate coated with pressure sensitive adhesive according to any of claims 1-5, characterized in that the region of the non-adhesive component comprises a polymer, copolymer or mixture of a polystyrene, a polyolefin, a polyurethane, a polyester, a polyamide , an epoxy, a polyacrylate or a polyvinyl acrylate. The pressure sensitive adhesive coated substrate according to any of claims 1-6, characterized in that the pressure sensitive adhesive component region comprises a gummy adhesive of a polystyrene polydiene block copolymer, a polyacrylate adhesive, an adhesive gummy of an acrylate copolymer or a gummy copolymer of polydiorganosiloxane polyurea. The pressure sensitive adhesive coated substrate according to any of claims 1-7, characterized in that the pressure sensitive adhesive coated substrate comprises a bandage. The pressure sensitive adhesive coated substrate according to any of claims 1-8, characterized in that the layer of pressure sensitive adhesive tape is a continuous adhesive layer.