JP5345994B2 - Nonwoven sheet, adhesive article and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a preferred adhesive article, i.e. a nonwoven sheet and adhesive article having enhanced tearing properties. <P>SOLUTION: Nonwoven sheet materials that are made with fibers, preferably tensilized nonfracturable staple fibers and binder fibers, and formed from a combination of internal bonding, smooth roll-calendering, and pattern embossing techniques and adhesive articles formed therefrom are provided. These sheet materials are especially useful as tape backings that are tearable with fingers in the web transverse direction and the web machine direction and also possess a number of other desirable properties, including acceptable tensile strength and enhanced overtaping, for example. A nonwoven sheet material, and adhesive article including the same, can include an embossed pattern having a variety of discontinuous configurations to enhance tearing properties in both the web transverse direction and web machine direction. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to nonwoven sheets and adhesive articles made therefrom, and more particularly to nonwoven sheet materials and adhesive articles having improved tear properties.

  Nonwoven sheet materials are often used as tape backings, web components, and the like. These tapes are commonly used in the healthcare industry to secure a variety of articles such as bandages, tubing and backing, and to secure pre-made bandage materials such as first aid bandages and island bandages. Is used. They are also commonly used to secure materials to certain products such as diagnostic electrodes, surgical grinding plates and monitoring electrodes.

  Tapes formed from nonwoven sheet materials fall into two general categories based on the required performance. Category I includes sheet materials that can be torn in the cross machine or cross web direction and tapes made therefrom. However, these materials often cannot be torn cleanly and therefore the torn ends are not flat or irregular. Category II, on the other hand, includes sheet materials and tapes that cannot be torn in either the down web direction or the cross web direction for practical purposes.

  In general, category I nonwoven materials are composed primarily of cellulose fibers and have a down web direction to cross web direction tensile strength ratio of less than 2.5 to 1. Cellulose fibers are inherently breakable (easily break when stressed), unlike many synthetic, polymer fibers that are essentially non-breakable.

  Cellulose fibers used in Category I sheet materials are bonded by chemical binders that fix or partially fix the fibers. In addition, the chemical binder increases the density of the sheet material and provides other advantages such as improved tensile strength, elongation at break, hand (ease of fit), reduced fuzz, and the special tear properties described above. However, these advantageous properties are quickly compromised when the sheet material gets wet, especially when saturated with water or other aqueous fluids.

  Category II materials are most often formed from synthetic fibers that are essentially non-breakable and are bonded either thermally, mechanically, or chemically to provide structural integrity to the sheet material. These materials vary depending on the particular structure, but exhibit improved tensile strength, elongation, and hand. For example, mechanically bonded Category II materials are generally softer and more fluffy than chemically bonded materials that tend to be harder and less fluffy. However, Category II sheet materials do not meet the fixation requirements required by the healthcare industry because they are essentially unable to tear in the cross-web direction in virtually all cases.

  Both Category I and II non-woven sheet materials and tapes are used fairly extensively in wound care and medical device fixation where healthcare is practiced. However, neither type of material has made significant progress in a wider area of the healthcare market due to its inherent limitations.

  Category I materials are not water resistant and cannot provide sufficient strength while maintaining flexibility, hand and / or reasonable tear properties. Strength can be improved by changing the orientation ratio of the fibers in the downweb direction to the crossweb direction at the expense of tearability. In addition, strength can also be improved by increasing the base fiber content and weight at the expense of hand and tearability.

  There are further limitations on changing the characteristics of category II sheet materials made of synthetic polymer fibers. A fairly good tearability can only be obtained by using fibers that make the sheet material and the resulting tape very stiff. In that way, the fiber-to-fiber bond is substantially fixed, making the fabric less adaptable, making tearing very difficult, not being trimmed, and not being straight It is no longer a thing.

  In recent years, many attempts have been made to improve the properties of Category I and II materials, or to provide nonwoven sheet materials and tapes with the desirable properties of both Category I and II materials. Different fiber types, contents and weights of nonwoven sheet materials have been tried. In addition, various bonding techniques are used, including bonding with chemical sizing agents, physical entanglement of the web (hydroentanglement), and thermal bonding such as by hot embossing. US Pat. No. 4,973,513 (chemical bonding with LAB), US Pat. No. 4,341,213 (chemical bonding to increase strength and flammability, US Pat. No. 4,772,499 (hydroentangle) And U.S. Pat. No. 3,737,368 and U.S. Pat. No. 3,507,943 (thermal embossing with engraved rollers).

  For example, U.S. Pat. No. 3,121,021 discloses a surgical adhesive tape formed from a tissue backing of rayon staple fibers coated with a non-sticky hydrophobic rubbery fiber sizing polymer. The polymer bonded backing is coated with a thin layer of pressure sensitive adhesive that exhibits a microporous structure after drying. Incorporation of a hydrophobic rubbery fiber sizing polymer serves to increase water repellency and the wet strength of this category I material. Similarly, U.S. Pat. No. 4,112,177 essentially provides a non-woven backing similar to U.S. Pat. No. 3,121,021, except that multiple adhesive layers are applied to the backing. And improving the overall adhesive properties of the tape formed therefrom. A further example of a porous double-coated adhesive tape is disclosed in US Pat. No. 4,844,973.

  U.S. Pat. No. 4,292,360 discloses a multilayer nonwoven sheet material that can be used to make a pressure sensitive adhesive tape. The sheet material is composed of two nonwoven webs that are stacked and bonded together by a rewetable chemical binder. The nonwoven web can be formed from any type or combination of staple fibers, single or combinations with binder fibers. In addition to the chemical binder, the sheet material can also optionally be calendered or embossed.

  U.S. Pat. No. 3,908,650 discloses a microporous tape formed from a nonwoven web coated with a porous layer of pressure sensitive adhesive on one side and a thermoplastic film on the other side. Yes. The fibers proximate to the thermoplastic layer are at least somewhat water repellent. Optionally, the fibrous web may be thermally bonded or chemically bonded with a sizing agent. The use of a thermoplastic layer increases the wear resistance and antifouling properties of the entire tape.

  U.S. Pat. No. 4,772,499 discloses a nonwoven web that is easily torn in the cross-web direction. The tearability of the web is improved by pattern-bonding a part of the web with a bonding agent. After drying, the web can be easily teared in the cross-web direction along the unbonded portions of the web. Similarly, U.S. Pat. No. 4,303,724 discloses the use of textured or temporary strands in the finishing of nonwovens to improve tear properties.

  German Patent DE 1 595 300 discloses a non-woven fabric formed from a hot calendered hydrous web leaving 10% to 40% by weight residual moisture. These webs are composed of unstretched polyester binder fibers and can optionally include stretched polyester fibers, polyacrylamide fibers and / or polyamideimide fibers. Further examples of thermal bonding as the primary means of reinforced nonwoven materials are also U.S. Pat. Nos. 4,731,277, 4,639,390, 4,511,615, 4,490,427. And 4,083,913. Furthermore, thermal bonding can be performed by embossing such sheet material using a heated engraved roller. See, for example, U.S. Pat. Nos. 3,737,368 and 3,507,943.

  U.S. Pat. No. 4,490,425 describes soft fuzz formed by thermal bonding staple fibers, endless fibers or both, and needle drilling (tacking) one or both sides of the fabric to form a fuzzy surface. Disclosed nonwoven fabrics. One side or more is then coated with a thermal adhesive to provide a fabric useful as a garment for various garments. Similar interlining materials and methods for making them are also disclosed in US Pat. Nos. 4,451,314 and 4,148,958.

  None of the aforementioned sheet materials or tapes combine the advantages of Category I and II materials well, while eliminating the disadvantages. In fact, a single nonwoven sheet material or tape made from it has so far been obtained with improved strength, improved overtaping and easy tearing in either direction while maintaining reasonable hand values. It is not done.

  The present invention relates to a nonwoven sheet material made from fibers, preferably stretch non-breakable staple fibers and binder fibers, formed from a combination of internal bonding, smooth roll calendering and pattern embossing techniques, and tapes formed therefrom. provide. These sheet materials are particularly useful as tape backings that can be torn with fingers in the crossweb and downweb directions to meet user requirements and also include, for example, acceptable tensile strength and improved overtaping. It also has a number of desired properties.

  One aspect of the present invention includes a nonwoven backing having a first surface and a second surface and having an embossed pattern on a first fibrous web, and a feeling coated on the first surface of the backing. A pressure sensitive adhesive article comprising a pressure adhesive is provided. According to the present invention, the embossed pattern is selected from the group consisting of at least two rows of the plurality of recesses in the first direction, which are arranged to form a column of the plurality of recesses in the second direction. The distance between the two recesses in one column is such that the distance between the two recesses in the second column and the plurality of column recesses in the second direction are arranged to form a plurality of column recesses in the first direction. Unlike the distance between two recesses in at least two rows of the plurality of recesses, the distance between the two recesses in at least one column differs along the first direction. The pressure sensitive adhesive article according to the present invention may also comprise a low adhesion backsize coated on the second surface of the backing and / or a release liner on the pressure sensitive adhesive coated on the first surface of the backing. it can. Generally, the pressure sensitive adhesive is selected from the group consisting of rubber adhesives, water based adhesives, solvent based adhesives, hot melt adhesives and combinations thereof. The pressure sensitive adhesive article according to the present invention may also further comprise a backing comprising a second nonwoven web, preferably laminated to the first nonwoven web.

  Another aspect of the present invention provides a fibrous web selected from the group consisting of at least two rows of a plurality of recesses in the first direction, arranged to form a column of a plurality of recesses in the second direction. A nonwoven sheet article having an embossed pattern, wherein the distance between two recesses in one column is the distance between the two recesses in the second column, and the plurality of columns in the second direction. The distance between the two recesses in at least one column is different from the distance between the two recesses in at least two rows of the plurality of recesses in the first direction arranged to form the recesses. Different nonwoven sheet articles are provided.

  In the article according to the invention, the fibrous web comprises non-breakable staple fibers, binder fibers and a binder.

  Preferably, the plurality of recesses is up to about 28% of the total surface area of the backing.

  Each of the plurality of recesses may have a shape selected from the group consisting of diamond, rectangle, circle, ellipse, triangle, “+” sign, “<” sign, “>” sign, and combinations thereof. Preferably, the distance between two consecutive recesses in the first direction is about 0.51 mm to about 0.36 mm, and the distance between two consecutive recesses in the second direction is about 0.51 mm to about 3 .6 mm. Preferably, the first direction and the second direction are substantially normal to each other.

  In one embodiment, each of the plurality of recesses in the row has a shape selected from the group consisting of alternating “+” and “−” symbols. In other embodiments, each of the plurality of recesses is a “+” sign, and the plurality of recesses is about 15% to about 22% of the total surface area of the backing. In still other embodiments, the plurality of recesses is a combination of a “+” sign and a “−” sign, and the plurality of recesses is about 15% to about 20% of the total surface area of the backing. In a further embodiment, the plurality of recesses is a combination of “−” sign and “|”, and the plurality of recesses is about 15% to about 22% of the total surface area of the backing. In a further embodiment, the plurality of recesses is a combination of “+” and “−” signs, and the plurality of recesses is about 15% to about 20% of the total surface area of the backing.

  A further aspect of the present invention comprises forming an irregularly interwoven fibrous web of stretchable non-breakable staple fibers and binder fibers and aligned to form a plurality of recesses in a second direction. Pattern embossing the fibrous web with a pattern selected from the group consisting of at least two rows of a plurality of recesses in the first direction, followed by pattern roll embossing followed by smooth roll kanda processing on the fibrous web And the step of smooth roll calendering followed by uniform internal bonding of the entire fibrous web using a chemical binder, the distance between the two recesses in one column being in the second column The distance between the two recesses and at least two rows of the plurality of recesses in the first direction arranged to form a plurality of column recesses in the second direction. That differs from the distance between the two recesses, there is provided a distance between two depressions in at least one column is a manufacturing method of the nonwoven sheet materials having different along the first direction.

  A further aspect of the present invention comprises the steps of forming an irregularly interwoven fibrous web of stretch non-breakable staple fibers and binder fibers, applying a first smooth roll calendering to the fibrous web, Pattern embossing a fibrous web in a pattern selected from the group consisting of at least two rows of a plurality of recesses in a first direction, arranged to form a column of recesses in a direction of 2; Uniformly bonding the entire fibrous web with a chemical binder, the distance between the two recesses in one column being the distance between the two recesses in the second column, and the second Unlike the distance between two recesses in at least two rows of the plurality of recesses in the first direction, which are arranged to form a plurality of column recesses in the direction, at least one column Provides a method for producing a non-woven sheet material in which the distance between the two recesses is different along the first direction and the smooth roll calendering is carried out before the pattern embossing or uniform internal bonding step . In one embodiment, uniform internal bonding is performed prior to pattern embossing. In other embodiments, pattern embossing is performed prior to uniform internal bonding.

  Preferably, the internal bonding step includes the step of injecting an aqueous chemical binder into the fibrous web.

  The method according to the present invention may further include the step of drying the fibrous web infused with the water-based chemical bonding agent until substantially all of the water is removed.

  Other steps included in the method according to the present invention include: coating a first surface of the embossed pattern web with a layer of pressure sensitive adhesive; and a second surface of the embossed pattern web. Coating the low adhesion composition and the pressure sensitive adhesive on the first surface of the embossed pattern web in contact with the low adhesion backsize on the second surface of the embossed pattern web; A step of winding a web of embossed pattern around a roll and a combination thereof.

  Still another embodiment of the present invention includes a step of forming a first irregularly interlaced fibrous web, a step of performing smooth roll calendering on the fibrous web, and pattern embossing the fibrous web. Forming an embossed pattern having a plurality of discontinuous recesses in the first direction and the second direction, uniformly bonding the entire fibrous web using a chemical bonding agent, and pressure sensitive bonding Coating the first surface of the fibrous web with a pressure sensitive adhesive article, wherein the pressure sensitive adhesive article has an overtaping value of less than about 76 mm. A manufacturing method is provided. The method also includes other steps such as laminating the second fibrous web to the first fibrous web or coating the second surface of the fibrous web with a low adhesion backsize.

  In one embodiment, pattern embossing of the fibrous web occurs prior to smooth roll calendering of the fibrous web and uniform internal bonding of the fibrous web. In other embodiments, smooth roll calendering of the fibrous web occurs prior to pattern embossing of the fibrous web and uniform internal bonding of the fibrous web. In yet another embodiment, uniform internal bonding of the fibrous web occurs prior to pattern embossing of the fibrous web.

  The terms “machine direction” and “down web direction” are used interchangeably and refer to the machine direction of the web. The fibers comprising the nonwoven sheet material are primarily arranged in the downweb direction of the nonwoven sheet material. The terms “cross machine direction” and “cross web direction” are used interchangeably and refer to a direction substantially perpendicular to the down web direction of the nonwoven sheet material.

  In the present specification, “embossed pattern” and “calendered pattern” are used interchangeably and refer to a predetermined configuration of a recess in a web surface. An embossed pattern is distinct from a “perforated” pattern that refers to a predetermined configuration of holes that pass through the entire thickness of the web. Thus, the pattern embossed on the web / tape backing according to the present invention is a recess in the non-perforated pattern on the web surface, which is preferably discontinuous in both the down web and cross web directions.

1 is a schematic view of one embodiment of an embossed backing material according to the present invention. FIG. FIG. 3 is a schematic view of another embodiment of an embossed backing material according to the present invention. FIG. 3 is a schematic view of a further embodiment of an embossed backing material according to the present invention. FIG. 6 is a schematic view of yet another embodiment of an embossed backing material according to the present invention. FIG. 3 is a schematic view of another embodiment of an embossed backing material according to the present invention. 1 is a schematic view of an embossed backing material including a series of discontinuous lines along the cross web direction of the material. 1 is a schematic view of an embossed backing material including a series of intersecting continuous lines along both the cross web and down web directions of the material.

Nonwoven Sheet Materials Nonwoven sheet materials and fibrous web components of tapes according to the present invention are wet processes, dry processes such as air layering and carding and direct processes for continuous fibers such as spunbonding and meltblowing. It is made according to a conventional method known in the industry including Some example methods are described in U.S. Pat. Nos. 3,121,021 (Copeland), 3,575,782 (Hansen), 3,825,379, 3,849,241 and No. 382,400.

  Suitable examples of fibrous web components include stretchable non-breakable staple fibers and binder fibers used to form the fibrous web components of the nonwoven sheet materials and tapes of the present invention, US Pat. No. 5,496, 603, 5,631,073, and 5,679,190 (all Riedel et al.). As used herein, “stretchable non-breakable staple fiber” refers to a staple fiber formed from a synthetic polymer, such that the polymer chains are substantially oriented in the machine or downweb direction of the fiber, and It is stretched during manufacture so that it does not break easily when a moderate breaking force is applied. By controlling and orienting these staple fibers, a highly regular crystallinity (generally greater than about 45% crystallinity) is imparted to the polymer chains comprising the fibers. Typically, the stretch non-breakable staple fibers of the present invention will not break unless a breaking force of at least 3.5 g / denier is applied.

  Suitable stretch non-breakable staple fibers according to the present invention include, but are not limited to, polyester staple fibers, polyolefin staple fibers, polyamide staple fibers, polyacrylate staple fibers, polycarbonate staple fibers, polysulfone staple fibers, or combinations thereof. It is not something that can be done. According to the present invention, breakable staple fibers such as rayon staple fibers, acrylic staple fibers, cellulose staple fibers, cotton staple fibers, etc. in small amounts, preferably less than 50% by weight.

  Preferably, the stretch non-breakable staple fibers comprise oriented polyolefin staple fibers such as oriented polyethylene, polypropylene or polybutylene staple fibers, oriented polyester staple fibers such as polyethylene terephthalate (PET) or combinations thereof. These oriented staple fibers are about 1 cm to about 10 cm in length, more preferably 2 cm to 5 cm, about 0.1 denier to about 20 denier, more preferably about 0.5 denier to about 5 denier, most preferably about A fineness of 0.7 denier to about 2 denier is exhibited.

  In a particularly preferred embodiment, the stretch non-breakable staple fiber is 0.95 denier polyester (PET) staple fiber or standard polyester staple fiber (PET), 1.2 denier polyester staple fiber and / or 2.0 denier. Includes oriented polyester staple fibers such as standard polyester staple fibers (PET).

  Any type of binder fiber can be used in accordance with the present invention as long as it can be melt bonded to the stretch non-breakable staple fiber of the fibrous web without breaking or substantially weakening the stretch non-breakable staple fiber. Can be used to form a web. In this regard, the binder fibers are preferably formed from one or more artificial thermoplastic polymers that can be melt bonded to the stretch non-breakable staple fibers used in the nonwoven sheet materials and tapes of the present invention. Further, the binder fiber is not limited to these, but includes a fully meltable binder fiber, a parallel binder fiber, a bicomponent binder fiber, an elliptical core-sheath binder fiber, a concentric core-sheath binder fiber, or a combination thereof. Various binder fiber configurations well known in the industry, including the industry, can be included.

  Suitable binder fibers include, but are not limited to, polyester binder fibers, thermoplastic polyethylene, polyolefin binder fibers such as polypropylene and polybutylene binder fibers, polyamide binder fibers, or combinations thereof. These binder fibers are about 1 cm to about 20 cm in length, more preferably 2 cm to 10 cm, about 0.1 denier to about 20 denier, more preferably about 0.2 denier to about 10 denier, most preferably about 0. It shows a fineness of 5 denier to about 6 denier.

  In a particularly preferred embodiment, the binder fiber comprises a core-sheath binder fiber comprising, for example, an oriented polyester or polyolefin fiber core surrounded by an outer sheath of meltable polyester or polyolefin resin. Specific examples of core-sheath binder fibers suitable for use in the fibrous web of the present invention include 1.5 denier, 38 mm, crystalline polypropylene core and meltable polyethylene sheath, and 2 denier, 38 mm, oriented polyester core and Examples include a meltable polyester sheath.

  The weight ratio of stretchable non-breakable staple fibers to binder fibers in the fibrous web will depend on the application of the nonwoven sheet material or tape of the present invention. In many cases, the predetermined strength, tensile properties, and other requirements of the nonwoven sheet materials and tapes of the present invention are necessary to ensure proper binding and ultimately the structural integrity of the fibrous web. It is obtained by balancing the amount of high strength, stretchable, non-breakable staple fiber with respect to the amount of thermoplastic binder fiber.

  Typically, about 95% to about 50%, preferably about 90% to about 60%, by weight of the fibrous web comprises one or more stretchable non-breakable staple fibers, and about 50% to about 5%. %, Preferably about 40% to about 10% by weight of the fibrous web is binder fiber. In a preferred embodiment, the weight ratio of stretch non-breakable staple fiber to binder fiber is about 10: 1 to about 1:10, more preferably about 5: 1 to about 1: 1, most preferably about 4: 1 to about. 2: 1.

The thickness of the nonwoven sheet material according to the present invention is highly dependent on the desired application. Usually, the thickness of the nonwoven sheet is about 0.04 mm to about 0.5 mm. When the desired end use of the nonwoven sheet material is a medical tape backing, the preferred thickness is from about 0.1 mm to about 0.4 mm. Further, the weight of the nonwoven sheet is from about 10 g / m ² to about 100 g / m ² , preferably from about 15 g / m ² to about 70 g / m ² .

In one preferred embodiment, the fibrous web is from about 20 wt% to about 2 denier, length 5cm polyester binder fibers and about 20 weight percent of the average total fiber weight of about about 1.5 denier 30 g / m ² of a length About 60% by weight of about 0.95 denier, 4 cm long oriented polyester staple fiber combined with 4 cm long rayon fiber.

In a second preferred embodiment, the fibrous web comprises essentially the same material as in the first embodiment, but instead of rayon fibers, an average total fiber weight of about 20% by weight is about 30 g / m ² . Contains polypropylene fiber with about 2.2 denier and 4 cm length.

  In accordance with the principles of the present invention, the fibrous web is internally bonded by chemical bonding agent, physical entanglement, or both, and pattern embossed to provide the nonwoven sheet material of the present invention.

  One method of internally bonding the fibrous web is to physically entangle the fibers after forming the web by conventional means well known in the industry. For example, the fibrous web can be needle tacked as described in US Pat. No. 5,016,331. In an alternative preferred method, the fibrous web can be hydroentangled as described in US Pat. No. 3,485,706. One method of hydroentangling is to use a fibrous web laminated between stainless steel mesh screens (eg, 100 mesh screen, National Wire Fabric, Star City, Arkansas) at a predetermined speed (eg, about 23 m / Minute) to pass through a high-pressure water jet (for example, about 3 MPa to about 10 MPa) to collide both sides of the web. The hydroentangled web is then dried and subjected to pattern embossing and chemical binder saturation as described herein.

  All nonwoven sheet materials according to the present invention are pattern embossed according to procedures well known in the art such as described in US Pat. Nos. 2,464,301, 3,507,943 and 3,737,368. Is done. Usually, the fibrous web is passed through a patterned metal roll with concavo-convex areas and a solid backup roll formed of metal or rubber. However, the fibrous web can also be fed between two patterned rollers that exhibit areas of corresponding or alternating engraving. In either case, it is common to supply heat to one or more rollers so that the fibrous web is thermally bonded along the pattern contact points.

  In a preferred embodiment, the fibrous web according to the invention is thermally embossed with a pattern roll and a solid backup roll. It is important to carefully control the temperature of the pattern roll during embossing. Typically, stretchable non-breakable staple fibers and binder fibers are thermally contacted at the point of contact without breaking the staple fibers (perforating staple fibers) or severely weakening the fibrous web below the usable strength level. The temperature must be such that it melts. In this regard, it is preferable to maintain the temperature of the pattern roll at about 70 ° C to 220 ° C, more preferably about 85 ° C to 180 ° C. Further, the pattern roll should be contacted with the nonwoven sheet material at a pressure of about 30 N / mm to about 120 N / mm, preferably about 35 N / mm to about 70 N / mm.

  The particular pattern carved on the embossing roll will vary depending on the intended use of the resulting nonwoven sheet material and tape. One skilled in the art will appreciate that after embossing, as long as a discontinuous embossing pattern is created in the material / tape backing, areas patterned with various pattern shapes (bonded areas) are obtained. . According to the present invention, the resulting embossed pattern bond area of the material / tape backing is preferably up to about 28% of the total surface area of the material / tape backing. More preferably, the patterned area should be about 15% to about 21% of the total surface area of the material / tape backing.

  While not wishing to be bound by any particular theory, the embossed pattern recesses are formed by the local dissolution of the fibrous web in the pattern of convex areas of the patterned embossing roll. it is conceivable that. The fibrous web is not broken by the process and instead maintains integrity. The physical dimensions of the embossed recesses and the physical dimensions of the non-recessed areas between the recesses (also referred to as “land spaces”) are important aspects of the present invention. The land space between the recess and each recess forms a separation line. Separation lines can be cross web and down web directions. Suitable to prevent premature separation (tear) and sufficient reduction in tensile strength to easily and consistently and reliably separate along both the cross web and down web directions There must be an acceptable balance between competing interests in high tensile strength. Surprisingly, it has been found that when the embossed pattern of the material / tape backing is up to about 28% of the total surface area of the material / tape backing, this balance is achieved in both the crossweb and downweb directions.

  Further, the separation line parameters required to define performance include the recess dimensions (length and width), land space dimensions (generally the length of the non-recess area between two consecutive recesses) and the recess dimension pair. This is the ratio of the land space dimensions. The interdependencies of these variables and how they work together that lead to material / tape backing performance must be considered together. Those skilled in the art will readily recognize that each recess in the embossed pattern has a variety of shapes, yet can be easily and consistently separated along a single separation line in both the cross web and down web directions. It will be understood. Such shapes include diamonds, squares, rectangles, triangles, circles, ellipses, letter shapes (for example, letters such as “V”, “X”, “A”, “+”, “−”, “<”, “>”). And a combination thereof.

  Desirably, the tensile strength of the embossed pattern of the material / tape backing in the downweb direction, measured according to the protocol defined herein, is at least about 8 N / cm width, preferably at least about 10 N / cm width. Desirably, the tensile strength of the embossed pattern of the material / tape backing in the cross-web direction, measured according to the protocol defined herein, is at least about 4 N / cm width, preferably at least about 6 N / cm width.

  According to the present invention, the embossing pattern preferably includes a plurality of recesses separated by land spaces in the first direction and the second direction. The arrangement of the plurality of recesses in the first direction is preferably at least two rows arranged so that the columns are formed by continuous recesses in the second direction. In a preferred configuration, the distance between the two recesses for at least one column varies along the first direction. In another preferred configuration, the distance between the two recesses in one column is different from the distance between the two recesses in the second column.

  In other embodiments of the invention, multi-layer (two or more layers) laminates can be formed. The laminate includes the nonwoven sheet of the present invention. In a preferred embodiment, the laminate consists of two layers of nonwoven sheet material joined by a tie layer. The tie layer may be any material that provides a strong bond between the layers of the nonwoven sheet material. When used as a tape structure, the layers of nonwoven sheet material must be bonded with sufficient strength so that they do not peel and cannot be peeled off by hand. Preferred tie layers include, but are not limited to, polypropylene, polyethylene, ethylene vinyl acetate and blends thereof. Suitable tie layers include, for example, films such as 0.4 mm blow XBP-486.0 from Consolidated Film (Chippewa Falls, Wis.) And Exon 3445 polypropylene pellets from Exxon Chemical Company (Houston, Tex.). Polypropylene in the form of a film extruded from.

  Additives can be incorporated into one or more of the nonwoven sheet material, chemical binder, tie layer, LAB and adhesive. Suitable additives include colorants (eg, pigments and dyes), processing aids (eg, surfactants and foaming agents) and spreaders (eg, fillers and gloss imparting, to name just a few examples) Agent).

  In FIG. 1, one embodiment of an embossing pattern 11 is shown with a material / tape backing 10. The embossed pattern 11 includes a plurality of concave portions 12 having a shape of “+” sign. It is the land space 14 that separates the recesses 12 for both the down web direction 13 and the cross web direction 15. The arrangement of the plurality of recesses 12 in the first direction (cross-web direction) is such that at least two rows 17 are arranged such that the columns 18 are formed by continuous recesses 12 in the second direction (downweb direction 13). Is preferred. Preferably, each row 17 and each column 18 are substantially normal to each other. The continuous recesses 12 separated by the land spaces 14 form down web separation lines 16 (along the columns 18 of the recesses 12) and cross web separation lines 16 '(along the rows 17 of the recesses 12). Given a tear force, the material / tape backing can be torn to the desired size 10 'along the down web separation line 16 and the cross web separation line 16'. As described above, there is a cooperative relationship between the dimensions of the recess 12 and the land space 14 that easily and consistently separate along a single separation line in both the cross web and down web directions. For example, in FIG. 1, the “+” sign of each recess 12 has dimensions of a total height of about 0.91 mm and a total width of about 0.51 mm. And about 0.20 mm in both directions of the cross web. Further, the land space between the recesses in the down web direction is about 0.36 mm and about 0.76 mm in the cross web direction. The total patterned area of this embossed pattern 11 is about 15.4% of the total surface area of the material / tape backing. Thus, in this configuration, the distance between the two recesses in at least one column varies along the first direction.

  FIG. 2 shows another embodiment of the embossing pattern 20. The embossed pattern 20 includes a plurality of recesses 22 and 22 ′ in the shape of “−” signs oriented along different lengths from the down web direction 23 to the cross web direction 25. It is the land space 24 that separates the recesses 22 for both the down web direction 23 and the cross web direction 25. The arrangement of the plurality of recesses 22 in the first direction (cross web direction 25) is at least two rows arranged such that the columns 28 are formed by continuous recesses 22 in the second direction (downweb direction 23). 27 is preferred. Preferably, each row 27 and each column 28 are substantially normal to each other. In FIG. 2, the longest dimension in the cross web direction of each concave portion 22 with a “−” sign is about 0.71 mm, and the shortest dimension in the cross web direction is about 0.20 mm (“−” of the concave portion when viewed along the downweb direction). Orientation). The longest dimension in the downweb direction of each concave portion 22 ′ is about 0.76 mm, and the shortest dimension in the downweb direction is about 0.20 mm (the orientation of the concave portion “|” Is). Further, the land space between the recesses 22 ′ in the down web direction is about 0.51 mm, and each recess 22 is about 1.07 mm. Each recess 22 'and 22 are separated by a distance of about 0.18mm in the cross web direction. The total patterned area of this embossed pattern 20 is about 18.6% of the total surface area of the material / tape backing. Thus, in this configuration, the distance between the two recesses in one column is different from the distance between the two recesses in the second column.

  FIG. 3 shows still another embodiment of the embossing pattern 30. The embossing pattern 30 includes a plurality of concave portions 32 having a shape of “+” sign. It is the land space 34 that separates each recess 32 in both the down web direction 33 and the cross web direction 35. In FIG. 3, the “+” sign for each recess 32 is about 0.91 mm in total height and width, and the thickness of each “+” segment is about 0.20 mm in both the downweb and cross web directions. Further, the land space between the recesses in the down web direction and the cross web direction is about 0.36 mm. The total patterned area of this embossed pattern 30 is about 20.5% of the total surface area of the material / tape backing.

  FIG. 4 shows a further embodiment of the embossing pattern 40. The embossing pattern 40 includes a plurality of recesses 42 having a “+” sign and a “−” sign shape in an alternating pattern in the cross web direction. Preferably, the same symbols are arranged in the downweb direction. It is the land space 44 that separates the recesses 42 in both the down web direction 43 and the cross web direction 45. In FIG. 4, the “+” sign of the embossed pattern 40 is about 0.91 mm in total height and width, and the thickness of each “+” segment is about 0.20 mm in both the down web and cross web directions. . The “−” sign of the embossed pattern 40 has a longest dimension of about 0.91 mm and a shortest dimension of about 0.20 mm. Further, the land space between the recesses in the down web direction and the cross web direction is about 0.36 mm. The total patterned area of this embossed pattern 40 is about 16.0% of the total surface area of the material / tape backing.

  FIG. 5 shows a further embodiment of the embossing pattern. The embossing pattern 50 is a pattern similar to that shown in FIG. 4 and is a combination of “+” and “−” recesses 52 separated by the land region 54, each having the dimensions described above with reference to FIG. doing. However, the embossing pattern 50 is rotated at an angle 57 of about 30 ° from the intersecting direction 55. Although shown with a 30 ° rotation, any pattern can be rotated at an angle of less than about 90 ° from the cross web direction.

  According to the present invention, the fibrous web is preferably calendered using a smooth roll, which forms a nip with another smooth roll. Thus, in a preferred embodiment, the fibrous web according to the present invention is thermally transferred by a smooth roll and a solid backup roll (eg metal covered with metal, rubber or cotton cloth) in addition to the pattern embossing described above. It is calendered. During calendaring, it is important to carefully control the temperature and pressure of the smooth roll. Typically, the fibers thermally melt at the point of contact without imparting undesirable properties to the fibrous web, such as unacceptable stiffness and / or poor overtaping. In this regard, it is preferable to maintain the temperature of the smooth roll at about 70 ° C to 220 ° C, more preferably about 85 ° C to 180 ° C. In addition, the smooth roll should be contacted with the fibrous web at a pressure of about 10 N / mm to about 90 N / mm, more preferably about 20 N / mm to about 50 N / mm.

  While not wishing to be bound by any particular theory, smooth roll calendering further imparts tensile strength to the fibrous web and improves various material / tape backing properties, including overtaping. It is considered a thing. Various factors in the medical tape environment, such as bonding to the back of the tape (also referred to here as “overtaping”), rounding of the tape edge after it is applied to the skin (a function of familiarity), etc. is important. Surprisingly, the tape backing made from the method including the smooth roll calendering process showed a very straight separation in both the down web and cross web directions when torn and increased overtaping performance.

  As described above, the fibrous web is preferably applied by a binder (also referred to herein as “resin bonding”). According to the present invention, various chemical binders can be applied to the fibrous web by industry recognized processes. Useful chemical binders include, but are not limited to, acrylic, vinyl acrylic, acetate / ethylene, polyvinyl acetate, polyurethane, and the like. Whenever a chemical binder is used, the binder fibers, including stretch non-breakable staple fibers and / or fibrous webs, must be compatible and easily bonded.

  Chemical binders include latex incorporating acrylic, styrene / butadiene rubber, vinyl acetate / ethylene, vinyl acetate / acrylate, polyvinyl chloride, polyvinyl alcohol, polyurethane, vinyl acetate, acrylic / vinyl acetate, styrene / acrylic, etc. Examples include, but are not limited to, chemical binders. These water-based chemical binders are about 20% to about 50 using suitable coating methods, including winding rods, reverse rolls, air knives, direct and offset gravure, driven blades, print bonds, foams and spray coating methods. It is common to apply to fibrous webs at% solids.

  Specific examples of chemical binders according to the present invention include the trade names RHOPLEX E-3636 and E-3522 (each about 50% solids styrene / acrylic latex binder) from Rohm & Haas (Philadelphia, PA), PHOPLEX E -2559 (approx. 52% solids acrylic latex binder), Mallard Creek polymer (Charlotte, NC) Model 4402 (approx. 50% solids styrene / butadiene rubber latex) and National Starch (Bridgewater, NJ) National Starch No. 78-6283 (acrylic / vinyl acetate copolymer latex of about 45% solids) (National Starch No. 78-6283), but is not limited thereto.

  The chemical binder is applied in an amount sufficient to provide the desired properties such as tensile strength and tear properties as demonstrated by the nonwoven sheet materials and tapes of the present invention. However, the amount of chemical binder can vary depending on the intended use. For example, more chemical binder is applied to increase the strength of the nonwoven sheet material and less binder is used to lower the material hand (ie, improve ease of fitting).

Typically, when the fibrous web is saturated with a chemical binder to form the nonwoven sheet material and tape of the present invention, the amount of the dried chemical binder in the fibrous web is from about 10 g / m ² to about 50 g. / M ² , preferably from about 15 g / m ² to about 40 g / m ² . In this regard, the weight ratio of the fiber comprising the fibrous web to the chemical binder incorporated into the fibrous web is from about 5: 1 to about 1: 5, more preferably from about 3: 1 to about 1: 3, most preferably about The ratio is preferably 2: 1 to 1: 2.

  As described above, the material / tape backing manufacturing method according to the present invention includes resin bonding of the fibrous web, pattern embossing and smooth roll calendering. In one embodiment, the preferred order of these steps is pattern embossing, smooth roll calendering and resin bonding. In yet another embodiment of the invention, the smooth roll calendering process is performed first. Next, a pattern embossing process or resin bonding follows the smooth roll calendering process. Surprisingly, it has been found that these preferred procedural steps result in a material / tape backing with improved tensile strength and overtaping without sacrificing straight cross web and down web tearing. . For example, all of these characteristics can be achieved by using one of the steps in the above sequence as compared to the pattern embossing, resin bonding and smooth roll calendering method, or the pattern embossing and resin bonding only method. Surprisingly it was found to be improved.

  The fibrous web according to the present invention can also optionally incorporate a water-based release coating such as low adhesion backsize (LAB) essentially simultaneously with the chemical binder or after the chemical binder has been incorporated into the web. Preferred usable LABs are those listed in US Pat. No. 4,973,513 and are applied by the method described in that patent. After applying the chemical binder and optionally LAB, the fibrous web is dried using suitable drying means such as contact drying, air circulation oven, impingement oven, air circulation oven, and the like.

Tape Fibrous web is resin bonded, smooth roll calendered, pattern embossed, and after forming the nonwoven sheet material of the present invention, the sheet material is wrapped around a roll for transport, or later adhesive or standard medical Multilayer laminates are applied to apply other suitable coatings used to form tapes, such as tapes, masking tapes, and the like. Alternatively, the non-woven sheet material may be conveyed directly to an adhesive coater to slit individual tape rolls.

  Preferably, a nonwoven sheet material is coated with a pressure sensitive adhesive layer to form a tape according to the present invention. In this regard, the pressure sensitive adhesive applied to the nonwoven sheet material may be a solvent based, aqueous based or hot melt adhesive. Suitable adhesives and methods of application include, for example, US Pat. No. 2,708,192 (phenolic cured rubber adhesive), US Reissue Patent No. 24,906 (aqueous and solvent-based adhesives) and US Pat. No. 4,833,179 (hot melt adhesive).

  In one embodiment, the non-woven sheet material of the present invention has a high solids latex pressure sensitivity that is not moisture sensitive and exhibits an excellent balance of adhesive properties such as high compliance and high shear without accumulating adhesive. Coat the adhesive. For example, for conventional methods of preparing these types of adhesives, see US Pat. Nos. 5,521,229 and 5,624,973 (both Lu et al.) And EP 554 832 B (Crandall et al.). )checking. The characteristics and advantages of the preferred pressure sensitive adhesive are due, at least in part, to the polymerizable surfactant and low molecular weight hydrophobic polymer present in the latex formulation.

  Preferred latex pressure sensitive adhesives coated on the nonwoven sheet material of the present invention include water, acrylate and vinyl monomers, ionic copolymerizable surfactants, optional chain transfer agents, optional crosslinkers and hydrophobic polymers. It is produced by emulsifying the mixture. The emulsion is heated with stirring under a nitrogen atmosphere and a portion is treated with an initiator to maintain temperature control. The reaction mixture is heated and stirred until the reaction is complete. The resulting acrylic latex is coated according to various conventional methods known to those skilled in the art.

The acrylate monomer component of the latex pressure sensitive adhesive preferably includes a C _{4 to} C ₁₂ alkyl ester acrylate monomer. Suitable alkyl ester acrylate monomers include, but are not limited to, n-butyl acrylate, amyl acrylate, hexyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, decyl acrylate, dodecyl acrylate, and mixtures thereof. It is not a thing.

Further, the vinyl monomer combined with the acrylate monomer is preferably 1) vinyl ester (including but not limited to vinyl acetate, vinyl propionate, vinyl butyrate, etc.), 2) (meso ) alkyl ester (methyl methacrylate C ₁ -C ₄ acrylic acid, methyl acrylate, ethyl acrylate, ethyl methacrylate, encompasses isobutyl methacrylate, and the like, not limited to these), 3) styrene and mixtures thereof Including.

  Useful copolymerizable hydrophilic acidic monomers include, but are not limited to, ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphoric acids, and mixtures thereof. Such compounds include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, citraconic acid, maleic acid, β-carboxyethyl acrylate, 2-sulfoethyl methacrylate, styrene sulfonic acid, 2-acrylamido-2-methylpropane. Examples include, but are not limited to, sulfonic acid and vinylphosphonic acid. Various combinations of these monomers can be used if desired. Due to their availability and effectiveness in reinforced (meso) acrylate pressure sensitive adhesives, the preferred hydrophilic acidic monomer is an ethylenically unsaturated carboxylic acid, most preferably acrylic acid.

  Examples of copolymerizable ionic surfactants useful in preferred latex pressure sensitive adhesives include, but are not limited to, those described in WO 89/12618. The surfactants described therein have a hydrophobic portion containing alpha-beta ethylenically unsaturated groups and a hydrophilic portion containing poly (alkyleneoxy) segments and ionic segments. Preferred copolymerizable surfactants are MAZON SAM-211 surfactants (PPG industry, ethylene polyalkoxyammonium sulfate, about 5 to about 25 alkoxy groups, typically about 15 to about 20 ethoxy groups. Group).

  The latex pressure sensitive adhesive is optional and not limited to 1,6-hexanediol diacrylate, poly (ethylene glycol) diacrylate, poly (butadiene) diacrylate, polyurethane diacrylate and trimethylolpropane. Crosslinkers including diacrylates such as triacrylates, multifunctional acrylates such as triacrylates and tetraacrylates; 4-acryloxybenzophenone; divinylbenzene; and mixtures thereof. Any chain transfer agent such as carbon tetrabromide, mercaptans, alcohols and mixtures thereof may also be included.

  As mentioned above, the preferred latex pressure sensitive adhesive comprises a low molecular weight hydrophobic polymer. As used herein, the term “hydrophobic polymer” refers to a water-insoluble polymer. Useful hydrophobic polymers have an average molecular weight of about 400 to about 50,000, preferably about 500 to about 20,000, and most preferably about 600 to about 10,000. Useful low molecular weight non-copolymerizable hydrophobic polymers include polystyrene resins such as PICCOLASTIC A75, D125 and D150 available from Hercules Chemicals; poly (methyl methacrylate) (PMMA) resins; polybutadiene; poly (alpha-methylstyrene) ); Butadiene-butylene block copolymers; and rosin esters such as FORAL 85 and 105 available from Hercules and mixtures thereof, but are not limited to these.

  The adhesive-coated tapes of the present invention are adhesive, such as low adhesion backsize (LAB) coated on the non-adhesive side of the tape, to facilitate winding of the tape for ease of use of the roll. It is also preferred to use a peelable liner or release coating that covers the agent layer. Preferably, the LAB coating is applied to the non-adhesive side of the tape using conventional coating methods in the textile industry.

  The LAB preferably comprises an aqueous composition, but solvent based materials such as polyvinyl carbamate are also useful. Suitable components of the aqueous LAB include, but are not limited to, polyethylene, fluorochemicals, acrylates, silicones, vinyl copolymers and combinations of these polymers with other polymers. For example, an acceptable LAB useful for the tape of the present invention is the aqueous LAB described in US Pat. No. 4,728,571, US Pat. No. 4,973,513.

  Applicants have invented a non-woven sheet material comprising essentially non-breakable fibers and tapes formed therefrom that are easily tearable (breakable) in the cross-web direction of the sheet or tape and are easy to use in use. did. In addition, these materials and tapes also exhibit a number of other advantageous properties including improved tensile strength, tearability, improved overtaping and uniform strength in both downweb and crossweb directions. .

  In general, non-woven sheet material or tape must sacrifice some properties for other properties. For example, to obtain a tape that can be torn in the cross-web direction (Category I tape), the overall tape strength must be compromised, among other things. Similarly, in order to obtain tapes with good tensile strength (category II tapes), tearability and in many cases ease of conformance are lost. Thus, the use of category I and II tapes is often limited. In contrast, the nonwoven sheet materials and tapes of the present invention are widely used in the healthcare field and other fields where a strong, familiar, and easily tearable tape is required. In particular, the non-woven sheet materials and tapes of the present invention have the advantage of tensile strength in the downweb and cross-web directions with typical category II material hands (ie, familiarity) and typical category I materials. Combined with the benefits of down and cross-web tearing, it provides a material with wide applicability in the healthcare, athletics and other fields.

  The special tear properties of the nonwoven sheet material or tape of the present invention are evaluated by the test procedure detailed in the examples below.

  The invention is further illustrated by the following examples. However, this is not intended to limit the scope of the present invention. All parts, ratios and percentages in the examples are by weight unless otherwise specified.

Test Protocol Tensile Strength Meter, commercially available under the trade name THWIN-ALBERT Tester Model Number JA / 2000 from Thwing-Albert (Philadelphia, PA), 2.54 cm wide sample, 12.7 cm gauge length and crosshead ASTM test method No. 1 using a speed of 12.7 cm / min. D3759-83 was performed. Recorded for each sample tested is the maximum force applied to the test sample to obtain a tensile value at break.

Hand A measure of the drape / familiarity of the sample by a total hand measurement in grams of the nonwoven sheet material sample. A material with a relatively high hand value is rigid and unfamiliar. Conversely, a relatively low hand value is a soft and familiar material. The hand values recorded for the samples of the present invention are THWIN-ALBERT HANDLE-O-METER model no. No. 211-300 (Thwing-Albert Instruments (Philadelphia, PA)). Obtained according to the procedure described in the instructions attached to 211-300. All hand measurements were performed on approximately 20 cm square sheet material.

Overtaping Clean Plexiglas with a series of "bottom" adhesive tape pieces measuring 5.08-cm x 25.4-cm, with the adhesive side down and rolling the pieces back and forth once with a 10-kg roller. Combined with a horizontal platform. A series of 2.54-cm × 25.4-cm “top” adhesive tape strips (taken from the same lot of samples as the “bottom”), with the adhesive side down, a series of “bottom” ”At the top. The top pieces were arranged in the center so as to extend over the width of the bottom piece so as to exceed 2.54 cm from the bottom piece. A 3 gram weight was attached to each extended end of the top piece and the piece was rolled back and forth once by a roller. The weighed end of each top tape piece was pulled from the back side of the bottom tape piece until the peel line reached the zero mark on the Plexiglas platform. The platform was transferred to a constant temperature and humidity room with a relative humidity of 40 ° C./75% and placed 20 degrees above the vertical so that the weight could be hung freely. After 1 hour, the distance of the “top” tape piece peeled from the fixed “bottom” tape piece was recorded as the “overtaping” value for the adhesive tape sample.

Tearability Cross direction tear test 7.6-cm (cross direction) x 10.2-cm (machine direction) backing or tape sample with a length of 10.2 between the thumb and forefinger of each hand at intervals of 1.3 cm or less -Kept in the center of -cm. The sample was torn until it was propagated to the end of the sample by moving the hands in opposite directions and perpendicular to the cross plane of the sample. The tear propagation speed was considered to be about 7.6 cm per second. The maximum tear distance away from a straight line was measured (in millimeters) using a metric ruler.

Machine direction tear test 7.6-cm length of the back and tape fingers of 7.6-cm (cross direction) x 30.5-cm (machine direction) with a thumb and index finger at intervals of 1.3 cm or less Held in the center of. The sample was torn until it propagated to the end of the sample by moving the hands in opposite directions and perpendicular to the machine direction plane of the sample. The tear propagation speed was considered to be about 7.6 cm per second. The maximum tear distance away from a straight line was measured (in millimeters) using a metric ruler.

Card nonwoven web (Web A)
The carded non-woven web used as starting material in the following examples is produced using conventional non-woven web forming technology on a machine marketed under the name HERGETH RANDOM-CARD by Hergeth-Hollingsworth (Duelman, Germany). Created. The fiber blend contained the following:
60% polyethylene terephthalate (PET) staple fiber (0.95 denier x 3.8 cm, L-70, Hoechst Celanese, Spartanburg, SC),
20% rayon staple fiber (1.5 denier x 4.0 cm, Merge 8649, Lenzing, Charlotte, NC), and 20% bicomponent PET thermal bonding fiber (2.0 denier x 3.8 cm, T-254, Hoechst Serra Needs, South Carolina, Spartanburg).
The resulting carded nonwoven web has a fiber weigh of 30 g / m ² and is referred to as “Web A” in the following examples.

Card nonwoven web (Web B)
Other carded nonwoven webs used as starting materials in the following examples were made using conventional nonwoven web forming techniques on a Hergeth Random-Card machine (Hergeth-Hollingsworth, Dülman, Germany). The fiber blend consisted of:
60% polyethylene terephthalate (PET) staple fiber (0.95 denier x 3.8 cm, L-70, Hoechst Celanese, Spartanburg, SC),
20% polypropylene staple fiber (2.2 denier x 4.0 cm, Hercules T-196, Wilmington, Delaware), and 20% bicomponent PET thermal bonding fiber (2.0 denier x 3.8 cm, T-254, Hoechst Celanese, Spartanburg, South Carolina).
The resulting carded nonwoven web has a fiber weigh of 30 g / m ² and is referred to as “Web B” in the following examples.

Card nonwoven web (Web C)
The other carded nonwoven webs used as starting materials in the following examples are obtained from conventional nonwoven web forming technology on a machine marketed under the name HERGETH RANDOM-CARD by Hergeth-Hollingsworth (Duelman, Germany). Created using. The fiber blend contained the following:
78% polyethylene terephthalate (PET) staple fiber (1.0 denier × 3.8 cm, T-121, Hoechst Celanese, Spartanburg, SC), and 22% bicomponent PET thermal bonding fiber (2.0 denier × 5 .1cm, K-52, Konamatsu
The resulting carded nonwoven web has a fiber weigh of 23 g / m ² and is referred to as “Web C” in the following examples.

Comparative example A (process sequence PR, engraving pattern A)
It was transferred to a two-roll heating calendar station (Energy Solutions, St. Paul, Minn.) At a speed of about 12.2 m / min, and pattern embossed using the processing conditions shown in Table 1 (Process Step-P). Comparative Example A (CA) was prepared using woven card web A. The calendar station has a smooth steel roll with a diameter of 25.4-cm × width of 55.9-cm arranged below, and has an engraved pattern (pattern A) 25.4-cm diameter × 55.9-cm width. The steel rolls were set up with the steel rolls positioned above. The bond area of engraved pattern A (pattern 60 shown in FIG. 6) is 11.5%, 0.914-mm (cross direction 65) × 0.356 mm in the cross direction and 1.067 mm away in the machine direction. It consisted of a rectangular recess 62 of 0.203-mm (machine direction 63).

The pattern-embossed web is subsequently passed through a gravure coating station at a speed of about 12.1 m / min and a nip pressure of about 0.41 N / mm ² to produce a 1% antifoam agent (antifoam B silicone emulsion). 37.5% solid acrylic vinyl acetate copolymer latex (product number 78-6283, National Starch, NJ, Bridgewater; 45% solids diluted with tap water), Dow Corning, Midland, Michigan) Resin bond (process step R) was performed. The gravure coater has a threaded rubber roll having a diameter of 20.3-cm × width of 61-cm disposed above, and a triple spiral pattern steel roll having a diameter of 20.3-cm × width of 61-cm of 16 lines / cm (northern end). (Graving, Green Bay, Wisconsin) was set up with the lower position. The resulting nonwoven sheet material was dried by passing through an oven at 188 ° C. at a rate of about 12.3 m / min and collected on a 7.62-cm cardboard core.

Comparative example B (process sequence PRS, engraving pattern A)
Nonwoven card web A was pattern embossed and resin bonded as described in Comparative Example A using the pattern embossing conditions listed in Table 1. The dried nonwoven sheet material was smooth roll calendered (process step-S) using the process conditions listed in Table 1. A smooth roll calendering process step similar to the pattern embossing step described in Comparative Example A, except that the calender station was set up with a smooth steel roll covered with cotton cloth instead of the engraved roll placed above Went. The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Examples 1 and 2 (process sequence PSR, engraving pattern A)
The nonwoven card web A is pattern embossed as described in Comparative Example A using the processing conditions listed in Table 1, and then described in Comparative Example B using the processing conditions listed in Table 1. Smooth roll calendering was performed as described above. The resulting nonwoven sheet material was resin bonded as described in Comparative Example A, dried in an oven and collected in a 7.62-cm cardboard core. Other nonwoven sheet materials were made in the same manner as shown in Example 2.

Example 3 (process sequence SPR, engraving pattern A)
Nonwoven card web A is smooth roll calendered as described in Comparative Example B using the processing conditions listed in Table 1, and then described in Comparative Example A using the processing conditions listed in Table 1. Pattern embossed as was done. The resulting nonwoven sheet material was resin bonded as described in Comparative Example B, dried in an oven and collected on a 7.62-cm cardboard core.

Example 4 (process sequence SRP, engraving pattern A)
Nonwoven card web A is smooth roll calendered as described in Comparative Example B using the processing conditions listed in Table 1 and then resin bonded as described in Comparative Example A and in an oven. And dried. The resulting nonwoven sheet material was pattern embossed as described in Comparative Example A using the processing conditions listed in Table 1 and collected on a 7.62-cm cardboard core.

Comparative example C (process sequence PR, engraving pattern A)
Using the pattern embossing conditions listed in Table 1, Comparative Example C (CC) was made using the non-woven card web A that was pattern embossed and resin bonded as described in Comparative Example A. . The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Comparative example D (process sequence PR, engraving pattern B)
Except for using the engraving pattern B (pattern 70 shown in FIG. 7) instead of the engraving pattern A, using the pattern embossing conditions listed in Table 1, as described in Comparative Example A, pattern embossing, Comparative Example D (C.D) was prepared using a resin-bonded nonwoven card web C. The bond area of engraving pattern B was 29.4% and consisted of a series of raised continuous line elements 72 and 72 'perpendicular to each other in the cross direction 75 and the machine direction 73, respectively. This so-called “box pattern” is described in US Pat. No. 5,496,603 (Riedel et al.). The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Comparative Example E (Process Sequence PRS, Engraving Pattern A)
The non-woven card web A was patterned as described in Comparative Example B using the processing conditions listed in Table 1 except that a smooth steel roll covered with a cotton cloth instead of a rubber material was used. Embossed, resin bonded and smooth roll calendered. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 5 (process sequence RSR, engraving pattern A)
The non-woven card web A was patterned as described in Example 2 using the processing conditions listed in Table 1 except that a smooth steel roll covered with a cotton cloth instead of a rubber material was used. Embossing, smooth roll calendering and resin bonding. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 6 (process sequence SPR, engraving pattern A)
The nonwoven card web A was smoothed as described in Example 3, using the processing conditions listed in Table 1, except that a smooth steel roll covered with cotton cloth instead of a rubber material was used. Roll calendering, pattern embossing and resin bonding. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 7 (process sequence SRP, engraving pattern A)
The nonwoven card web A was smoothed as described in Example 4 using the processing conditions listed in Table 1 except that a smooth steel roll covered with a cotton cloth instead of a rubber material was used. Roll calendering, pattern embossing and resin bonding. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 8 (process sequence SPR, engraving pattern C)
The non-woven card web A, except that the engraved pattern C (shown in FIG. 2 as described above) is used instead of the engraved pattern A, and a smooth steel roll covered with a cotton cloth is used instead of the rubber material. Using the processing conditions listed in Table 1, smooth roll calendering, pattern embossing and resin bonding were performed as described in Example 3. The bond area of the engraving pattern C was 18.6%, and consisted of rectangular recesses arranged in both the cross direction and the machine direction. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 9 (process sequence SPR, engraving pattern D)
The non-woven card web A is used, except that the engraving pattern D (shown in FIG. 3 as described above) is used instead of the engraving pattern A, and a smooth steel roll covered with a cotton cloth is used instead of the rubber material. Using the processing conditions listed in Table 1, smooth roll calendering, pattern embossing and resin bonding were performed as described in Example 3. The bond area of the engraving pattern D was 20.5%, and consisted of plus-shaped recesses arranged in a cross direction row and a machine direction column. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 10 (process sequence SPR, engraving pattern E)
The nonwoven card web A was described in Example 3 using the processing conditions listed in Table 1 except that the engraving pattern E (as shown above, shown in FIG. 1) was used instead of the engraving pattern A. In the street, smooth roll calendering, pattern embossing and resin bonding were performed. The bond area of the engraving pattern E was 15.4%, and consisted of elongated cross-shaped recesses arranged in a cross direction row and a machine direction column. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 11 (process sequence SPR, engraving pattern F)
The non-woven card web A is used except that the engraving pattern F (shown in FIG. 4 as described above) is used instead of the engraving pattern A, and a smooth steel roll covered with a cotton cloth is used instead of the rubber material. Using the processing conditions listed in Table 1, smooth roll calendering, pattern embossing and resin bonding were performed as described in Example 3. The bond area of the engraving pattern F was 16.0%, and was composed of alternating rectangular and plus-shaped recesses arranged in a crossing direction row and a machine direction column. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Example 12 (process sequence SRP, engraving pattern F)
The non-woven card web A was used in place of the engraving pattern A instead of the engraving pattern A (described in Example 12 and shown in FIG. 4), and a smooth steel roll covered with a cotton cloth was used instead of the rubber material. Was smooth roll calendering, resin bonding and pattern embossing as described in Example 4 using the processing conditions listed in Table 1. Also, acrylic vinyl acetate copolymer latex binder (Product No. 78-6283) was replaced with acrylic styrene copolymer latex binder (Product No. E-3636, Rohm & Haas, Philadelphia, PA; 50% solid diluted with water). Used instead of. The resulting nonwoven sheet material was dried in an oven and collected on a 7.62-cm cardboard core.

Comparative Examples F and G and Examples 13-16
Adhesive Tape The nonwoven sheet materials described in Comparative Examples A and B and Examples 1-4 were converted to Comparative Examples F and G and the adhesive tapes of Examples 13-16, respectively. Emulsion pressure sensitive adhesive (89/6/3/2) composed of polymer isooctyl acrylate / vinyl acetate / acrylic acid / D-125 polystyrene resin (Hercules Chemicals) (89/6/3/2) on the smooth side of the nonwoven sheet material PSA) was coated at 28 g / m ² . The preparation of this adhesive is described in EP 554 832 B. The pattern embossed side of the sheet material was coated with ² g / m ² of urethane low adhesion backside (LAB) composed of the reaction product of polyvinyl alcohol and octadecyl isocyanate (described in US Pat. No. 3,121,021). .

Evaluation Examples 1 to 4 and Comparative Examples A and B
The nonwoven sheet materials described in Comparative Examples A and B and Examples 1-4 were cut into appropriate sample sizes and evaluated for tensile strength at break and hand (machine direction and cross direction). The results are shown in Table 2. All of the nonwoven sheet samples in these examples were observed to be tearable by hand and torn with clean straight lines with minimal fraying in the crossweb and downweb directions.

Examples 5-12 and Comparative Examples C, D and E
The nonwoven sheet materials described in Comparative Examples C, D and E and Examples 5-12 were cut into appropriate sample sizes and evaluated for tensile strength at break and tearability (machine direction and cross direction) (machine direction) And cross direction). The results are shown in Table 3.

Examples 13-16 and Comparative Examples F and G
The adhesive tapes described in Comparative Examples F and G and Examples 13-16 were cut into appropriate sample sizes and evaluated for overtaping. The results are shown in Table 4. All of the adhesive tape samples in these examples were observed to be tearable by hand and torn in a clean straight line with minimal fraying in the cross web direction.

Conclusion From the test results in Tables 2, 3 and 4, the manually tearable nonwoven sheet material and adhesive tape of the present invention (all made by resin bonding, pattern embossing and smooth roll calendering process steps) It can be concluded that it has improved tensile strength and / or overtaping properties when compared to the corresponding material (Comparative Examples AG) made without a smooth roll calendar process step or PRS process sequence. For example, it can be seen from Table 2 that the sheet material made from the SRP and PSR process sequences has the highest tensile strength. From Table 4 it can be seen that all adhesive tapes made from sheet materials made using SRP, SPR and PSR process sequences have excellent overtaping properties.

  From the test results in Table 3, it can be concluded that the hand-tearable nonwoven sheet material and adhesive tape of the present invention can be designed with engraved patterns so that they are torn very straight in the cross, machine or both directions. . Furthermore, changing the sequence of bonding steps can provide improved tensile strength properties when compared to corresponding materials made without a smooth roll calendering process step (Comparative Examples C and D). For example, the nonwoven sheet material of engraving pattern A (Table 3) had the highest tensile strength when compared to the sheet material created by the SRP process sequence.

Comparative example H (process sequence PR, engraving pattern G)
Nonwoven card web A was conveyed to a two-roll heating calendar station (Energy Solutions, St. Paul, Minn.) At a speed of about 13 m / min, and pattern embossed using the processing conditions shown in Table 5 (process steps) -P). The calendar station has a smooth steel roll with a diameter of 25.4-cm × width of 55.9-cm arranged below, and a diameter of 25.4-cm × width of 55.9-cm with an engraved pattern (pattern G). The steel rolls were set up with the steel rolls positioned above. The bond area of engraved pattern G (shown in FIG. 6) is 12%, 0.5 mm in the cross direction, 0.8-mm (cross direction) × 0.5-mm (machine direction) 1 mm away in the machine direction Direction) rectangular recesses. The pattern-embossed web is subsequently passed through a gravure coating station under the conditions listed in Table 5 to produce 0.5% antifoam (Anfoam B silicone emulsion, Dow Corning, Midland, Michigan) and 0 25% solid acrylic vinyl acetate copolymer latex (Product No. 78-6283, National Starch, New Jersey, Bridgewater) containing 5% surfactant (TRITON GR-5, Union Carbide, Connecticut, Canada); Resin bond (Process Step R) with 45% solid diluted with water). The gravure coater has a threaded rubber roll having a diameter of 20.3-cm × width of 61-cm disposed above, and a triple spiral pattern steel roll having a diameter of 20.3-cm × width of 61-cm of 16 lines / cm (northern end). (Graving, Green Bay, Wisconsin) was set up with the lower position. The resulting nonwoven sheet material was dried by passing it through an oven under the conditions listed in Table 5 and collected on a 7.62-cm cardboard core.

Example 17 (process sequence SPR, engraving pattern G)
Nonwoven card web A was transported to a two-roll heated calender station (Energy Solutions, St. Paul, Minn.) At a speed of about 13 m / min, and smooth roll calendered using the processing conditions in Table 5 (Process) Step-S). Similar to the pattern embossing process described in Comparative Example H, except that the calendar station was set up with a smooth steel roll (25.4 cm diameter x 55.9 cm width) instead of an engraved roll placed above. This step was performed. The resulting nonwoven sheet material was pattern embossed and resin bonded as described in Comparative Example F using the pattern embossing conditions listed in Table 5. The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Comparative example I (process sequence PR, engraving pattern A)
Nonwoven card web B was conveyed to a two-roll heating calendar station (Energy Solutions, St. Paul, Minn.) At a speed of about 13 m / min, and pattern embossed using the processing conditions shown in Table 5 (process steps) -P). The calendar station has a smooth steel roll with a diameter of 25.4-cm × width of 55.9-cm arranged below, and has an engraved pattern (pattern A) 25.4-cm diameter × 55.9-cm width. The steel rolls were set up with the steel rolls positioned above. The bond area of engraved pattern A (shown in FIG. 6) is 11.5%, 0.35 mm in the cross direction, 0.91-mm (cross direction) × 0.203, 1.067 mm away in the machine direction. It consisted of a rectangular recess of −mm (machine direction). The pattern embossed web was then resin bonded as described in Comparative Example H under the conditions listed in Table 5. The gravure coater has a threaded rubber roll having a diameter of 20.3-cm × width of 61-cm disposed above, and a triple spiral pattern steel roll having a diameter of 20.3-cm × width of 61-cm of 16 lines / cm (northern end). (Graving, Green Bay, Wisconsin) was set up with the lower position. The resulting nonwoven sheet material was dried by passing it through an oven under the conditions listed in Table 5 and collected on a 7.62-cm cardboard core.

Example 18 (process sequence SPR, engraving pattern A)
Nonwoven card web A was smooth roll calendered as described in Example 17 using the conditions listed in Table 5. This web was subsequently pattern embossed as described in Comparative Example I using the conditions listed in Table 5. The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Example 19 (process sequence SPR, engraving pattern A)
Nonwoven card web B was smooth roll calendered as described in Example 17 using the conditions listed in Table 5. This web was subsequently pattern embossed as described in Comparative Example I using the conditions listed in Table 5. The calender-embossed web was then passed through a gravure coating station under the conditions listed in Table 5 to produce a 0.5% antifoam agent (Anfoam B silicone emulsion, Dow Corning, Midland, Michigan). ) And 0.5% surfactant (Triton GR-5, Union Carbide, Canada, Connecticut) 25% solid acrylic polymer solution (E-3522, Rohm and Haas, Philadelphia, PA) Resin bonded (process step R) with 52% solid diluted with deionized water). The gravure coater has a threaded rubber roll having a diameter of 20.3-cm × width of 61-cm disposed above, and a triple spiral pattern steel roll having a diameter of 20.3-cm × width of 61-cm of 16 lines / cm (Northern end (Graving, Green Bay, Wisconsin) was set up with the lower position. The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Example 20 (process sequence SRP, engraving pattern A)
Nonwoven card web B was smooth roll calendered as described in Example 17 using the processing conditions listed in Table 5, and then resin bonded as described in Example 19 for comparative examples. Pattern embossing as described in I. The resulting nonwoven sheet material was collected in a 7.62-cm cardboard core.

Comparative Examples J and K and Examples 21-24
The multilayer laminates of Comparative Examples J and K and Examples 21-24 were made from the non-woven sheet materials of Comparative Examples H and I and Examples 17-20 to produce Comparative Examples J and K and Examples 21-24, respectively. did. Each multilayer laminate was prepared by sandwiching a polypropylene film between two nonwoven sheets, and an array of nonwoven sheet / tie layer / nonwoven sheet was formed. This three layer sample was placed on a preheated Carver press (machine No. 2824-1; Fred S. Carver, Menomonee Falls, Wis.) Platen (15.2 cm × 15.2 cm) at 0.6 MPa for 30 seconds, Placed at 182 ° C. Polypropylene film (0.4 mm blow XBP-486.0; consolidated film (obtained from Chippewa Falls, Wis.)) Served as a tie layer to bond the two nonwoven sheets.

Evaluation The multilayer laminates described in Comparative Examples J and K and Examples 21 to 24 were cut into appropriate sample sizes, and evaluated for tensile strength at break and tear propagation speed (machine direction and cross direction).

  Tensile strength was measured using a Model 1122 Instron Tensile Tester (Instron, Canton, Mass.) Equipped with a 45N load cell of model number 2511-105 (Actual Size Assembly A40-41A). For all tests, a crosshead speed of 12.7 m / min and a gap of 5 cm was used. A 12.7 cm x 1.27 cm sample was conditioned at constant temperature (20 ° C) and humidity (50%) for at least 4 hours before testing in a conditioned environment.

  A tear test was performed in both MD and CD directions according to ASTM D1922 using an Elmendorf tester (Thwing Albert Instruments, model number 60-200). Samples cut to 6.35 cm x 6.35 cm were conditioned as described in Tensile Strength Measurements and placed on the jaws of the tester and clamped. Before releasing the pendulum, an initial slit was made. The test measured the force required to propagate a straight tear with the requirement that it not tear more than 6.4 mm from the initial cut.

  The results are shown in Table 6. All samples were tearable by hand and were observed to tear with a fairly clean straight line in the cross web direction with minimal fraying. All samples were suitable as backing for masking tape. The sample has sufficient tensile strength that it can be peeled off from a dry paint without being peeled off or torn, and is sufficient to prevent the paint solvent from penetrating the backing and penetrating the adhesive. It was non-porous.

CONCLUSION According to the test results shown in Table 6, the multi-layer laminate (all made by resin bonding, pattern embossing and smooth roll calendering process steps) of the present invention is a smooth roll calender process step. It can be seen that it had improved tensile strength when compared to the corresponding laminates made without (Comparative Examples J and K). For example, Example 21 showed a 20% increase over Comparative Example J in MD tension while maintaining good hand tearability in the CD direction.

  From these examples, card nonwoven web fibers, binders, adhesive chemistry and coating weight, and processing conditions tailored to the specific end use purpose (web formation, calendering temperature, calender roll materials and patterns, etc.) It can be seen that a wide range of desirable physical properties can be obtained by adapting.

  The entire disclosures of all patents, patent applications and publications are each incorporated herein by reference. The above description is intended to be illustrative and not limiting.

  Various modifications and alterations of this invention will become apparent to those skilled in the art from the foregoing description without departing from the scope and spirit of this invention. The present invention is not unduly limited to the exemplary embodiments defined herein.

Claims (2)

A pressure sensitive adhesive article comprising a nonwoven backing having a first surface and a second surface, and a pressure sensitive adhesive coated on the first surface of the backing,
Has a pattern in which the backing is embossed fibrous web, the embossed pattern is arranged to form a column of the plurality of recesses in the down web direction, at least a plurality of recesses in the cross-web direction includes two rows, the same reference numerals are arranged in the down-web direction, the distance between two depressions in one column is different from the distance between two depressions in a second column, at least one The distance between two recesses in a column is different along the cross web direction, and each of the recesses in a row has a shape including alternating “+” and “−” symbols, and is embossed Pressure sensitive adhesive article wherein the pattern has a bonded area of up to 28% of the total surface area of the fibrous web. Arranged so as to form a column of the plurality of recesses in the down web direction, a nonwoven sheet article having an embossed pattern fibrous web comprising at least two rows of a plurality of recesses in the cross-web direction,
The distance between two depressions in one column is different from the distance between two depressions in a second column, the same reference numerals are arranged in the down-web direction, between two recesses in at least one column Are different along the cross web direction, and each of the plurality of recesses in a row has a shape including alternating “+” and “−” symbols, and the embossed pattern is the fibrous web A nonwoven sheet article having a bonded area of up to 28% of the total surface area of.

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