Reslurrable enhanced water-activated tape

Abstract

Repulpable water-activated adhesive tapes, in particular reinforced laminated water-activated paper tapes, and methods of making the same are disclosed. The repulpable water-activated tape includes an outermost paper layer having a top surface and a bottom surface, a reinforcement adjacent the bottom surface of the outermost paper layer, an innermost paper layer having a top surface and a bottom surface, the top surface of the innermost paper layer is adjacent to the reinforcement, at least a portion of a starch-based lamination adhesive disposed about each of the outermost paper layer, the reinforcement, and the innermost paper layer, and a water-activated adhesive adjacent to the bottom surface of the innermost paper layer. A re-slurrable starch-based laminating adhesive and an adhesive tape comprising the adhesive are also described.

Description

Technical Field

[0001] The present disclosure relates to repulpable reinforced water activated tapes and their manufacture. Background Art

[0002] Adhesive tapes used to seal cartons or carton flaps during the manufacturing process or after the carton is filled are well known. One of the most common constructions is a standard kraft paper tape that includes a water-soluble or water-activated adhesive on one side. Rolls of this tape can be dispensed by a machine that relies on the longitudinal stiffness of the tape to unwind it from the roll and force it through a tape wetting device. Various modifications to this type of tape have been attempted over the years to meet different requirements in carton manufacturing and sealing as well as environmental sustainability goals for recyclability, but with limited success. Summary of the invention

[0003] In a first example, a water-activated tape is provided, comprising: an outermost paper layer having a top surface and a bottom surface, a reinforcement adjacent to the bottom surface of the outermost paper layer, an innermost paper layer having a top surface and a bottom surface, the top surface of the innermost paper layer adjacent to the reinforcement, at least a portion of a starch-based laminated adhesive disposed around each of the outermost paper layer, the reinforcement, and the innermost paper layer, and a water-activated adhesive adjacent to the bottom surface of the innermost paper layer. In one example, at least 60% to about 99% of the water-activated tape disclosed herein is repulpable using Test Procedure A specified in the 2013 Fibre Box Association Voluntary Standard for Repulping and Recycling Treated Corrugated Paperboard to Improve Its Performance in the Presence of Water and Water Vapor ("FBA Standard"). In one example, at least 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or more than 99% of the water-activated tape is repulpable. In one example, at least 60% to about 99% of the tape disclosed herein is repulpable. In one example, the yield of the water-activated tape disclosed herein according to the FBA standard is at least 60% to about 99%. In one example, the yield of the water-activated tape is at least 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or more than 99%.

[0004] In one aspect, one or both of the innermost paper layer and the outermost paper layer comprises bleached kraft paper or natural kraft paper.

[0005] In one example, alone or in combination with any of the foregoing aspects, the reinforcement comprises a tape, ribbon or yarn of a polymer or glass. In one example, alone or in combination with any of the foregoing aspects, the reinforcement comprises a unidirectional, bidirectional or tridirectional tape, ribbon or yarn of a polymer, glass or a water-soluble polymer.

[0006] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive includes: one or more plant or synthetic starches; one or more plant starches or synthetic starches combined with one or more polymers; one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and mixtures thereof; or one or more synthetic starches, one or more chemically modified, enzymatically modified, mechanically modified, and thermally modified plant starches mixed with one or more polymers.

[0007] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive is contiguous or semi-contiguous with the innermost paper layer, the outermost paper layer, and the reinforcement.

[0008] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive further comprises a crosslinking agent and optionally a catalyst.

[0009] In one example, alone or in combination with any of the foregoing aspects, the crosslinking agent comprises one or more of melamine resin or melamine polymer, alkoxylated melamine resin, bezoquamine resin, glycoluril resin, urea-formaldehyde resin, glyoxal, sodium metaphosphate, and mixtures thereof.

[0010] In one example, alone or in combination with any of the preceding aspects, the catalyst is a blocked or unblocked sulfonic acid catalyst or an inorganic acid catalyst.

[0011] In one example, alone or in combination with any of the foregoing aspects, the water-activated adhesive includes: one or more plant and / or synthetic starches, plant and synthetic starches mixed with one or more polymers, or chemically modified, enzymatically modified, mechanically modified or thermally modified plant and synthetic starches, or chemically modified, enzymatically modified, mechanically modified or thermally modified plant and synthetic starches mixed with one or more polymers.

[0012] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive: resists wetting during dispensing and activation of the water-activated adhesive; and has sufficient solubility for repulpability.

[0013] In a second example, a method of making a repulpable water-activated tape is provided, the method comprising introducing at least one starch-based laminating adhesive to a reinforcement: a top major surface of an innermost paper layer, the innermost paper layer having a bottom major surface, the bottom major surface having the water-activated adhesive; and a bottom major surface of an outermost paper layer, wherein the reinforcement is located between the top major surface of the innermost paper layer and the bottom major surface of the outermost paper layer.

[0014] In one example, the starch-based laminating adhesive is contiguous or semi-contiguous with the innermost paper layer, the outermost paper layer, and the reinforcement.

[0015] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive includes: one or more plant or synthetic starches; one or more plant or synthetic starches combined with one or more polymers; one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and mixtures thereof; or one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, and thermally modified plant starches mixed with one or more polymers.

[0016] In one example, alone or in combination with any of the foregoing aspects, the starch-based laminating adhesive further comprises a crosslinking agent and optionally a catalyst.

[0017] In one example, alone or in combination with any of the foregoing aspects, the crosslinking agent comprises one or more of melamine resin or melamine polymer, alkoxylated melamine resin, benzoquinamine resin, glycoluril resin, urea-formaldehyde resin, glyoxal, sodium metaphosphate and mixtures thereof.

[0018] In one example, alone or in combination with any of the preceding aspects, the catalyst is a blocked or unblocked sulfonic acid catalyst or an inorganic acid catalyst.

[0019] In one example, alone or in combination with any of the foregoing aspects, the water-activated adhesive comprises one or more plant starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and blends thereof with one or more polymers.

[0020] In one example, alone or in combination with any of the preceding aspects, one or both of the innermost paper layer and the outermost paper layer comprises bleached kraft paper or natural kraft paper.

[0021] In one example, alone or in combination with any of the foregoing aspects, the reinforcement comprises a tape, ribbon or yarn of a polymer, glass or water-soluble polymer. In one example, alone or in combination with any of the foregoing aspects, the reinforcement comprises a bidirectional or tridirectional tape, ribbon and / or yarn of a polymer, glass or water-soluble polymer.

[0022] In one example, a starch-based laminating adhesive is provided, which includes: one or more plant starches and synthetic starches; one or more plant starches and synthetic starches combined with one or more polymers; one or more plant starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, and thermally modified plant starches; or, one or more plant starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, and thermally modified starches combined with one or more polymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to understand and appreciate how the present disclosure may be implemented in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0024] Figure 1 is a perspective view of a roll of tape according to one example of the present disclosure.

[0025] Figure 2 yes Figure 1 An enlarged cross-sectional view of the tape along section line 2-2 showing its various layers.

[0026] Figure 3 It is a schematic diagram of three-way enhancement.

[0027] Figure 4 is an exemplary manufacturing process for providing the tapes disclosed herein.

[0028] Figure 5 is another exemplary manufacturing process for providing the tapes disclosed herein. DETAILED DESCRIPTION

[0029] The water activated tape (WAT) disclosed herein comprises a starch-based laminating adhesive. Starch is a renewable plant-based polymer, thus eliminating or reducing some or all of the disadvantages of conventional reinforced water activated tape structures (such as those using non-renewable amorphous polyalphaolefin (APAO) laminating adhesives).

[0030] Previous attempts to add polymer films to tapes have been inadequate, at least in terms of providing sustainability. In one aspect, the polymer film is used as a layer to carry the water-activated adhesive. The problem with this attempt is that the polymer film does not hold the water-soluble or water-activatable adhesive very effectively. On the other hand, the polymer film is cold laminated to the innermost paper layer using an adhesive to form the tape, where the polymer can be peeled off after application due to the low bond strength provided by the adhesive between the polymer film and the innermost paper layer. Neither of these is a desired property for a water-activated paper tape. Therefore, the water-activated paper tape of the present disclosure is an improvement over these previous attempts to use polymer films in water-activated paper tapes.

[0031] The following detailed description will illustrate the general principles of the present invention, examples of which are additionally illustrated in the accompanying drawings. In the drawings, like reference numerals indicate identical or functionally similar elements.

[0032] Figure 1 A roll 130 of water activated tape 100 is shown wound on a core 118. Figure 1 and Figure 2 To explain, from top to bottom relative to the page, the water-activated tape 100 includes an outermost paper layer 124, a reinforcement 122 and a starch-based laminated adhesive, an innermost paper layer 112, and a water-activated adhesive layer 114. The outermost paper layer 124 (also referred to as the substrate) has a first major (top) surface away from the innermost paper layer 112, and a second major (bottom) surface adjacent to the reinforcement 122. The outermost paper layer 124 has a substantially infinite length and has a width, and the second major (bottom) surface of the outermost paper layer 124 defines a thickness. In one example, the thickness of the outermost paper layer 124 is between 1.85 and 3.7 mils. In one example, the outermost paper layer 124 can be printed by any method for printing paper, and after printing, can be coated or treated to prevent the print from getting dirty.

[0033] The reinforcement 122 and the starch-based laminating adhesive are introduced between the outermost paper layer 124 and the innermost paper layer 112. Various methods of introducing the laminating adhesive between the outermost paper layer 124 and the innermost paper layer 112 can be used, such as knife coating, solvent distribution, roller coating, extrusion, extrusion lamination, etc. In one example, the starch-based laminating adhesive is present at a thickness of about 0.1 mil to about 2 mil. In another example, the starch-based laminating adhesive is present at a thickness of about 0.5 mil (12.7 microns) to about 1.3 mil (32.5 microns). The surfaces to be laminated of the corresponding paper layers 112, 124 and / or the reinforcement 122 can be pre-treated using methods such as corona or flame treatment to ensure or enhance adhesion.

[0034] In one example, the starch-based laminated adhesive is contiguous or semi-contiguous with the innermost paper layer 112, the outermost paper layer 124, and the reinforcement 122. In one example, the starch-based laminated adhesive is semi-contiguous with the innermost paper layer 112, the outermost paper layer 124, and the reinforcement 122. In one example, the starch-based laminated adhesive at least partially fills all or some voids or gaps in the reinforcement 122.

[0035] In one example, after lamination, the reinforcement 122 is adjacent to the second major (bottom) surface of the outermost paper layer 124. In one example, after lamination, the reinforcement 122 is directly adjacent to the second major (bottom) surface of the outermost paper layer 124, with no intermediate layers or materials therebetween.

[0036] In one example, after lamination, the reinforcement 122 is adjacent to the first major (top) surface of the innermost paper layer 112. In one example, after lamination, the reinforcement 122 is directly adjacent to the first major (top) surface of the innermost paper layer 112, with no intermediate layers or materials therebetween.

[0037] In one example, after lamination, reinforcement 122 is directly adjacent to the second major (bottom) surface of outermost paper layer 124 and directly adjacent to the first major (top) surface of innermost paper layer 112 with no intervening layers or materials therebetween.

[0038] In one example, the starch-based laminating adhesive is a synthetic starch or a plant starch, or a blend thereof. In one example, the starch-based laminating adhesive comprises a combination of one or more plant starches or synthetic starches with one or more polymers. As used herein, "plant starch" is a starch separated, derived and or purified from any plant source by any means. In one example, the plant starch is derived from or obtained from (but not limited to) cassava, corn, sorghum, wheat, sago, tapioca, beans, barley, rice and / or potatoes. Plant starch and non-plant starch from other sources can be used.

[0039] As used herein, synthetic starch includes "modified plant starch", such as any plant starch that is chemically modified, genetically modified, enzymatically modified, mechanically modified and / or thermally modified. As used herein, synthetic starch also includes non-plant starch, such as starch prepared from carbon dioxide.

[0040] In one example, starch-based laminating adhesives include one or more synthetic starches or plant starches mixed with one or more polymers. In one example, starch-based laminating adhesives include thermoplastic starch (TPS) that is destroyed and / or plasticized. In one example, TPS is melt processable, for example, will flow under high temperature and pressure, and can be extruded. For example, starch-based laminating adhesives include starch-polyester, starch-polycaprolactone, starch-cellulose acetate, esterified starch and blends thereof. In one example, starch-based laminating adhesives are starches of synthetic and / or plant origin combined or mixed with polyacrylic acid polymers or copolymers. Starch-based laminating adhesives can be used together with one or more plasticizers, fillers, additives, processing aids, etc.

[0041] In one example, the starch includes an amylose:amylopectin ratio of about 0:100 to about 30:70.

[0042] The starch-based laminating adhesive may be applied to the innermost paper layer 112, the outermost paper layer 124, and / or the reinforcement 122 as an aqueous or non-aqueous solvent cast, solventless, or as a molten film or as a coating using extrusion, any form of roller coating, knife coating, rod coating, die coating, or doctor blade coating, curtain coating, or any suitable coating method.

[0043] In one example, after the starch-based laminating adhesive is disposed between the paper and / or reinforcement, it is allowed to dry or heated to promote the removal of water and / or other volatile materials. In one example, after the starch-based laminating adhesive is disposed between the paper and / or reinforcement, it is cross-linked alone or in combination with drying and / or heating. In one example, the starch-based laminating adhesive is cross-linked with an amine resin. In one example, the starch-based laminating adhesive is cross-linked with an amine resin and a catalyst. In one example, after lamination, the starch-based laminating adhesive resists rewetting, and after distribution, when the water-activated tape is exposed to rain / snow, it will not be substantially rewetted, however, the starch-based laminating adhesive is substantially or completely repulpable.

[0044] In one example, a water-activated tape having a starch-based laminate adhesive and reinforcement of the present disclosure has sufficient water resistance such that when the water-activated tape is dispensed and activated, the integrity of the tape is at least partially maintained. Sufficient water resistance is at least the ability to resist separation of the paper layers when rewetted during the tape dispensing process. Once applied to a carton, the paper layers of the tape resist separation under wet conditions for at least 2 hours. In one example, sufficient water resistance means that neither the inner or outer paper layers delaminate from the reinforcement after being fully immersed in water for up to two hours.

[0045] Likewise, the water-activated tape having the starch-based laminated adhesive and reinforcement of the present disclosure has sufficient water resistance such that the integrity of the tape is maintained when the water-activated tape is subsequently exposed to ambient moisture after being water-activated and applied to a carton. Sufficient water resistance for the tape to adhere to the carton is at least the ability to resist delamination of the tape from the carton after being completely immersed in water for up to two hours. The water-activated tape having the starch-based laminated adhesive and reinforcement of the present disclosure has sufficient water resistance and is substantially repulpable.

[0046] In one example, at least 60% to about 99% of the water activated tape is repulpable. In one example, at least 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or more than 99% of the water activated tape is repulpable. In one example, the tape (including any reinforcement) will be considered to be at least 60% to about 99% repulpable according to the FBA method. In one example, the tape and the carton associated therewith are considered to be at least 60% to about 99% repulpable. In one example, the tape itself is considered to be at least about 60% to about 75% repulpable according to the FBA method.

[0047] In one example, the starch-based laminated adhesive is substantially free of a cross-linking agent. In one example, the starch-based laminated adhesive comprises a cross-linking agent. In one example, the cross-linking agent is a melamine resin (or a melamine polymer). In one example, the cross-linking agent is an iminomelamine resin. In one example, the amine resin is a methylated iminomelamine resin. In one example, the amine resin is an alkoxylated melamine resin.

[0048] Examples of amine resins suitable as crosslinking agents for the starch-based laminating adhesives disclosed herein include methylated melamine formaldehyde, methoxymethylated melamine, ethoxymethylated melamine, propoxymethylated melamine, butoxymethylated melamine, hexamethylol melamine, ethoxymethylated melamine, propoxymethylated melamine, and butoxymethylated melamine. Examples of highly methylated melamine resins include: 303, 350, 9370; partially hydroxymethylated and highly alkylated methylated iminomelamine resins, e.g. 323, 327; Partially methylated melamine resins (highly methylated / alkoxylated and / or partially methylated / alkoxylated), e.g. 385, 373, 370; high solid mixed ether melamine resins, e.g. 1130, 324; n-butylated melamine resins, e.g. 1151, 615; n-butylated high imino melamine resins, e.g. 1158; and isobutylated melamine resins, e.g. 255-10. CYMEL melamine resins are available from Solvay (Rock Hill, SC). In one example, methylated formaldehyde melamine resins, methoxymethylated melamine resins, ethoxymethylated melamine resins, propoxymethylated melamine resins, butoxymethylated melamine resins, hexamethylol melamine resins, alkoxyalkylated melamine resins (e.g., methoxymethylated melamine resins, ethoxymethylated melamine resins, propoxymethylated melamine resins, butoxymethylated melamine resins), benzoquinamine resins, glycoluril resins, urea-formaldehyde resins, and mixtures thereof are used in combination with an acid catalyst. Other methods of crosslinking starch may be used, with or without acid catalysis, such as citric acid, malonic acid, epichlorohydrin, glyoxal, sodium trimetaphosphate, and phosphorus oxychloride.

[0049] Examples of catalysts include heat activated or high energy (UV, electron beam, etc.) activated catalysts. In one example, the catalyst is a polymer or oligomer. In one example, the catalyst is a blocked or unblocked sulfonic acid catalyst. In one example, the catalyst is amine blocked p-toluenesulfonic acid, amine blocked dodecylbenzenesulfonic acid, p-toluenesulfonic acid, dinonylnaphthalene disulfonic acid, dinonylnaphthalenesulfonic acid, 2-dodecylbenzenesulfonic acid, citric acid, malonic acid, inorganic acid (phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid), etc. Suitable catalysts are commercially available, such as from Allnex (Alpharetta, GA). Products. One or more catalysts may be used. One or more catalyst promoters may be used.

[0050] In one example, the starch-based laminating adhesive comprises about 10-90 weight percent (wt%) solids of at least one synthetic, chemically modified or thermally modified starch, with the remainder being substantially water. In one example, the ratio of starch to water is about 0.5:1 to about 1:0.5. In one example, the amount of cross-linking resin used is about 0.1 to about 10 wt% of the total weight of the starch.

[0051] In one example, the amount of cross-linking resin used is about 0.5 to about 5 wt % of the total weight of starch. In one example, the amount of cross-linking resin used is about 0.75 to about 2.5 wt % of the total weight of starch.

[0052] In one example, the amount of catalyst used is about 0.05 to about 2 wt % of the total weight of the starch. In one example, the amount of catalyst used is about 0.1 to about 1 wt % of the total weight of the starch. In one example, the amount of crosslinker for the starch laminating adhesive is such that the laminating adhesive is substantially no longer wettable when the water-activated tape is dispensed, but is at least partially dissolved during paper repulping. In one example, the amount of catalyst used is added in an amount such that the laminating adhesive is substantially no longer wettable when the water-activated tape is dispensed, or after the tape is applied (e.g., the laminating adhesive is substantially no longer wettable when exposed to ambient moisture), yet the tape is at least 60% or more repulpable.

[0053] The innermost paper layer 112 has a first main (top) surface adjacent to the reinforcement 122, and a second main (bottom) surface away from the outermost paper layer 124. The innermost paper layer 112 has a substantially infinite length and has a width less than the length defined by the first side and the second side. The first main (top) surface and the second main (bottom) surface of the innermost paper layer 112 define a thickness. In an example, the thickness of the innermost paper layer 112 is selected according to the intended use of the tape product. In an example, the thickness of the innermost paper layer 112 and the outermost paper layer 124 are the same. In an example, the thickness of the innermost paper layer 112 and the outermost paper layer 124 are different.

[0054] The second major (bottom) surface of the innermost paper layer 112 receives a water-activated adhesive layer 114. In one example, the thickness of the water-activated adhesive layer 114 is between 0.5 and 1.0 mil. In one example, the water-activated adhesive layer 114 is adjacent to the second major (bottom) surface of the innermost paper layer 112. In one example, the water-activated adhesive layer 114 is directly adjacent to the second major (bottom) surface of the innermost paper layer 112, with no intervening layers or materials therebetween.

[0055] The water activated adhesive layer 114 can be applied to the innermost paper layer 112 as an aqueous or non-aqueous solvent cast, solventless, or as a molten film or as a coating using extrusion, any form of roller coating, knife coating, rod coating, die coating or doctor blade coating, curtain coating or any suitable coating method.

[0056] The water-activated adhesive layer 114 can be any conventional water-activated adhesive. In one example, the water-activated adhesive includes a plant or synthetic starch or a blend thereof as described above. In one example, the water-activated adhesive includes one or more synthetic or plant starches, or a blend thereof. In one example, the water-activated adhesive includes one or more synthetic or plant starches combined or mixed with one or more polymers. In one example, the water-activated adhesive includes one or more synthetic or plant starches combined or mixed with a polyacrylic acid polymer or copolymer. In one example, the water-activated adhesive includes one or more synthetic or plant starches combined or mixed with a polyacrylamide polymer or copolymer.

[0057] In one example, the starch used in the water-activated adhesive is the same as the starch used in the laminating adhesive. In another example, the starch used in the water-activated adhesive is different from the starch used in the laminating adhesive. The water-activated adhesive requires rewetting to adhere to the carton; the laminating adhesive is cross-linked to prevent rewetting during water activation of the tape during dispensing, provided that the degree of crosslinking, if any, is such that the repulpability of the tape is substantially maintained.

[0058] In one example, the reinforcement 122 can be a tape, ribbon, or yarn, wherein the tape or yarn is arranged in any combination of orientations. In one example, the reinforcement 122 is a tape, ribbon, or yarn that is at least partially oriented in the machine direction (MD), including cross-hatching, diagonal lines, or an arrangement of tapes, ribbons, or yarns. Figure 3 As shown, in one example, a tri-directional yarn reinforcement is used as reinforcement 122. The tape, ribbon or yarn of reinforcement 122 can be selected from organic, inorganic or organic-inorganic composite materials. In one example, the yarn of reinforcement 122 is selected from organic polymers or copolymers. In one example, the reinforcement used in the water-activated tape and enhanced water-activated tape disclosed herein is selected from materials that are at least partially soluble and / or can be incorporated into the kraft (sulfate) repulping process using one or more chemicals and / or heat (e.g., sodium hydroxide, sodium hypochlorite, hydrogen peroxide, polyethylene glycol and combinations thereof) under typical and / or standard conditions.

[0059] In one example, reinforcement includes two-way or three-way adhesive tape, ribbon or yarn. In one example, reinforcement includes two-way or three-way adhesive tape, ribbon or yarn comprising polyester or glass (glass fiber). In one example, reinforcement includes two-way or three-way glass fiber, and its basis weight is about 3-7 grams per square meter. In one example, reinforcement includes three-way glass fiber, and its basis weight is about 5-6 grams per square meter. Suitable three-way glass fiber as reinforcement 122 can be obtained from St.Gobain Adfors, such as TGC2211 / A. Other glass or polymer yarns can be used as reinforcement 122.

[0060] In one example, the ribbon, tape or yarn of reinforcement 122 are selected from at least part of sustainable organic polymers or copolymers. In one example, the ribbon, tape or yarn of reinforcement 122 are selected from the blends of polyvinyl alcohol polymers, polyvinyl alcohol copolymers, polyvinyl alcohol polymers and polyvinyl alcohol copolymers with the same or different molecular weight, the same or different saponification degree and the same or different chemical composition. As used herein, polyvinyl alcohol (PVOH) (to) polymers include plasticized PVOH materials. The plasticizer system of plasticized PVOH can be one or a combination of conventional plasticizers, including polyols, waxes, hydrocarbon oils, mineral oils, polyethylene glycols, propylene glycol, polyethylene oxide, polypropylene oxide, glycerine, mannitol, pentaerythritol, trimethylolpropane, starch, chitosan, erythritol, polyvinylamine and ionomers. Other plasticizers and / or plasticizing systems can be used.

[0061] In one example, the ribbons, tapes, or yarns of reinforcement 122 are selected from partially or substantially hydrolyzed polyvinyl acetate polymers, partially or substantially hydrolyzed polyvinyl acetate copolymers, blends of polyvinyl acetate polymers and polyvinyl acetate copolymers of the same or different molecular weights, the same or different levels of acetate content, and the same or different chemical compositions.

[0062] In one example, the ribbons, tapes or yarns of reinforcement 122 are selected from blends of partially or substantially hydrolyzed polyvinyl acetate polymers with polyvinyl alcohol polymers and polyvinyl alcohol copolymers. Such blends may contain a plurality of polyvinyl acetate copolymers, polyvinyl acetate (co)polymers and polyvinyl alcohol (co)copolymers having the same or different molecular weights, the same or different degrees of acetate content or saponification, and the same or different chemical compositions.

[0063] In one example, the ribbon, tape or yarn of the reinforcement 122 is selected from a blend of partially or substantially hydrolyzed polyvinyl alcohol polymers and ionic polymers or ionic copolymers. Such a blend may contain polyvinyl alcohol (co) copolymers and ionic (co) polymers having the same or different molecular weights, the same or different degrees of saponification, and the same or different chemical compositions. Other partially water-soluble or at least partially alkali-soluble polymer yarns may be used as reinforcement 122.

[0064] In one example, the reinforcement 122 of the present disclosure may include one or more commercially available products of PVOH tape, PVOH ribbon, or PVOH yarn. Commercially available PVOH yarns include Nitivy's (Tokyo, Japan) Yarn.

[0065] The water-activated adhesive 114 can be any conventional water-activated adhesive or an adhesive developed below that is suitable for use in box sealing or carton sealing tapes (also known as packaging tapes). In one example, the water-activated adhesive 114 includes a plant starch or a plant starch blended with one or more polymers. In one example, the water-activated adhesive 114 includes a chemically modified, mechanically modified, or thermally modified plant starch, or a chemically modified, mechanically modified, or thermally modified plant starch blended with one or more polymers.

[0066] The water activated adhesive 114 can be applied to the innermost paper layer 112 as a solvent cast, solventless or melt film, or as a coating using extrusion, any form of roller coating, knife coating, rod coating or doctor blade coating, curtain coating or any suitable method. In one example, the water activated adhesive 114 is present at a thickness of about 0.5 mil to about 1.0 mil. Other thicknesses of the water activated adhesive 114 can be used.

[0067] The starch-based laminating adhesive includes a material that can be concentrated, diluted, softened, or heated to laminate, and laminate the outermost paper 124, the reinforcement, and the innermost paper layer 112. Typically, the starch-based laminating adhesive is capable of forming a bond between the outermost paper layer 124, the reinforcement 122, and the outermost paper layer 112. In one example, under dry bonding conditions, the starch-based laminating bond strength and the water-activated bond strength are substantially the same. In one example, after manufacturing the tape of the present disclosure, after rewetting (e.g., during water activation before placement on a carton), the starch-based laminating bond strength will be greater than the water-activated tape bond strength.

[0068] Optionally, one or more additives included in any of the above layers include one or more of UV inhibitors, antioxidants, pigments, and antistatic agents, but are not limited thereto.

[0069] The innermost paper layer 112 and the outermost paper layer 124 can be the same or different paper composition, thickness, color, etc., respectively. In one example, the innermost paper layer 112 and the outermost paper layer 124 are any type of paper, including but not limited to crepe paper, non-crepe paper or release paper. In one example, kraft paper (such as bleached kraft paper or natural kraft paper) is used as the innermost paper layer 112 and the outermost paper layer 124, respectively. In one example, the innermost paper layer 112 and the outermost paper layer 124 are bleached kraft paper or unbleached kraft paper, respectively. In one example, the innermost paper layer 112 and the outermost paper layer 124 are creped NBSK (Northern Bleached Softwood Kraft) paper webs, respectively.

[0070] In one example, water-activated adhesive layer 114 exists with the necessary thickness of giving box or packaging enough or desired sealing performance when being used for its intended purpose.For example, water-activated adhesive layer 114 exists with the thickness of about 0.5mil to about 1.0mil.Water-activated adhesive layer 114 can be any conventional water-activated adhesive or the adhesive that is applicable to box sealing or carton sealing tape (also referred to as packaging tape) of following development.In one example, water-activated adhesive layer 114 is based on starch, for example chemically modified or heat-modified starch.The example of starch that can be used for water-activated adhesive layer 114 includes but is not limited to cassava (cassava), corn, sorghum, wheat, sago, cassava (tapioca), beans, barley, rice and / or potato.

[0071] A continuous method of making a water-activated tape of the present disclosure includes providing a water-activated paper tape including an innermost paper layer having a water-activated adhesive defining a bottom major surface thereof, and extrusion laminating a reinforcement and a paper backing to the innermost paper layer opposite the water-activated adhesive. The extrusion lamination disposes the innermost lamination layer adjacent to the innermost paper layer and includes extrusion laminating the reinforcement, the paper backing, and the adhesive paper together. The method may also include winding the tape onto a roll and cutting the wound tape into a plurality of rolls of reinforced water-activated tape.

[0072] Example

[0073] like Figure 4 , an exemplary manufacturing process is described wherein a top layer of white kraft paper is laminated to a reinforcement and sized paper layer using a laminating adhesive comprising starch or a starch derivative, a crosslinking agent, and optionally an acid catalyst. Figure 4, shows an exemplary manufacturing process 200 of the water-activated tape 100 disclosed herein. The innermost paper layer 112 is unwound from a roll 202, and a water-activated adhesive 114 is applied to the bottom major surface of the innermost paper layer 112 by a reverse roll coater 207 and dried in a forced hot air oven 205. Then, the top side of the glued innermost paper layer 112 with the dried water-activated adhesive 114 on the bottom side is coated with a starch-based laminate adhesive, such as by slot die coating 208. The glued innermost paper layer 112 with the dried water-activated adhesive 114 on the bottom side and the starch-based laminate adhesive on the top side is combined with a reinforcement 122, such as from a roll 210, and an outermost paper layer 124 from a roll 212, and fed into a nip roll 214. The nip roll 214 may be heated. The tape 100 may be at least partially dried by drying rolls (cans) 216 and then further dried and / or cured / crosslinked, such as by hanging oven 220, before being wound onto finishing rolls 224. The tape 100 may be cut to desired widths using conventional methods.

[0074] refer to Figure 5 , another exemplary manufacturing process 300 of the water-activated tape 100 disclosed herein is shown. A starch-based laminated adhesive is applied to the top side of the innermost paper layer 112 unwound from a roll 202, for example, by slot die coating 208. The innermost paper layer 112 and the starch-based laminated adhesive on the top side are combined with the outermost paper layer 124 from the roll 212 using a reinforcement 122, for example, from a roll 210, and fed between nip rolls 214. The nip rolls 214 may be heated. The tape 200 may be at least partially dried by a drying roll (drying can) 216, and then further dried and / or optionally cured / crosslinked, for example, by a hanging oven 220. The water-activated adhesive 114 is applied to the bottom major surface of the innermost paper layer 112 by a reverse roll coater 207 and dried in a forced hot air oven 205. The glued innermost paper layer 112 having the dried water-activated adhesive 114 on the bottom side is then wound onto a finishing roll 224. The tape 100 may be cut to a desired width using conventional methods.

[0075] Although certain examples of the present disclosure have been described with reference to specific combinations of elements, various other combinations may also be provided without departing from the teachings of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the specific examples described herein and shown in the accompanying drawings, but may also include combinations of elements of the various illustrated examples and aspects thereof.

Claims

1. A water-activated tape comprising: an outermost paper layer having a top surface and a bottom surface; a reinforcement adjacent to the bottom surface of the outermost paper layer; an innermost paper layer having a top surface and a bottom surface, the top surface of the innermost paper layer being adjacent to the reinforcement; at least a portion of a starch-based laminate adhesive disposed about each of the outermost paper layer, the reinforcement, and the innermost paper layer; and A water activated adhesive is adjacent to the bottom surface of the innermost paper layer.

2. The water activated tape of claim 1, wherein one or both of the innermost paper layer and the outermost paper layer comprises bleached kraft paper or natural kraft paper.

3. The water activated tape of claim 1, wherein the reinforcement comprises a tape, ribbon or yarn of a polymer and / or glass.

4. The water activated tape of claim 3, wherein the reinforcement comprises a unidirectional, bidirectional or tridirectional tape, ribbon or yarn of a polymer, glass or a water soluble polymer.

5. The water activated tape of claim 1, wherein the starch-based laminating adhesive comprises: One or more plant or synthetic starches; one or more plant starches or synthetic starches combined with one or more polymers; one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and mixtures thereof; or one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, and thermally modified plant starches mixed with one or more polymers.

6. The water activated tape of claim 1, wherein the starch-based laminate adhesive is contiguous or semi-contiguous with the innermost paper layer, the outermost paper layer, and the reinforcement.

7. The water activated tape of claim 1, wherein the starch-based laminating adhesive further comprises a crosslinking agent and optionally a catalyst.

8. The water activated tape of claim 1, wherein the crosslinking agent comprises melamine resin or melamine polymer, alkoxylated melamine resin, benzoquinamine resin, glycoluril resin, urea-formaldehyde resin, and mixtures thereof.

9. The water activated tape of claim 7, wherein the catalyst is a blocked or unblocked sulfonic acid catalyst or an inorganic acid.

10. The water activated tape of claim 8, wherein the water activated adhesive comprises one or more plant starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and blends thereof with one or more polymers.

11. The water activated tape of any of the preceding claims, wherein the starch-based laminating adhesive: resists wetting during dispensing and activation of the water activated adhesive; and has sufficient solubility for reslurry.

12. A method of making a repulpable water-activated tape comprising: The following surfaces are laminated to the reinforcement using at least one starch-based laminating adhesive: a top major surface of an innermost paper layer, the innermost paper layer having a bottom major surface having a water activated adhesive thereon; and the bottom major surface of the outermost paper layer; The reinforcement is located between the top major surface of the innermost paper layer and the bottom major surface of the outermost paper layer.

13. The method of claim 12, wherein the starch-based laminating adhesive is contiguous or semi-contiguous with the innermost paper layer, the outermost paper layer, and the reinforcement.

14. The method of claim 12, wherein the starch-based laminating adhesive comprises: One or more plant starches or synthetic starches; one or more plant starches or synthetic starches combined with one or more polymers; one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and mixtures thereof; or one or more synthetic starches, chemically modified, enzymatically modified, mechanically modified and thermally modified plant starches mixed with one or more polymers.

15. The method of claim 12, wherein the starch-based laminating adhesive further comprises a cross-linking agent and optionally a catalyst.

16. The method of claim 12, wherein the crosslinking agent is methylated melamine formaldehyde, methoxymethylated melamine, ethoxymethylated melamine, propoxymethylated melamine, butoxymethylated melamine, hexamethylol melamine, ethoxymethylated melamine, propoxymethylated melamine, butoxymethylated melamine, benzoquinoline resin, glycoluril resin, urea-formaldehyde resin, and mixtures thereof.

17. The method of claim 15, wherein the catalyst is a blocked or unblocked sulfonic acid catalyst or an inorganic acid.

18. The method of claim 12, wherein the water activated adhesive comprises one or more plant starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified plant starches, and blends thereof with one or more polymers.

19. The method of claim 12, wherein one or both of the innermost and outermost paper layers comprise kraft paper.

20. The method of claim 12, wherein the reinforcement comprises tapes, ribbons, or yarns of polymer and / or glass.

21. The method of claim 20, wherein the reinforcement comprises unidirectional, bidirectional or tridirectional tapes, ribbons or yarns of polymer, glass and / or water soluble polymer.

22. A starch-based laminating adhesive comprising: one or more of plant starch and synthetic starch; one or more plant starches and synthetic starches combined with one or more polymers; One or more of vegetable starch, synthetic starch, chemically modified, enzymatically modified, mechanically modified and thermally modified vegetable starch; or One or more vegetable starches, synthetic starches, chemically modified, enzymatically modified, mechanically modified, thermally modified vegetable starches combined with one or more polymers.

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