Starch extruded films / adhesives and methods

Abstract

The present disclosure relates to a continuous low shear process for compounding starch. In one aspect of the present disclosure, the starch may be applied directly to, for example, a tape product as a mesh, film or layer.

Description

Technical Field

[0001] The present disclosure relates to a continuous low-shear method for compounding starch and thereby producing films and / or adhesives and their products. In one aspect of the present disclosure, the starch can be applied directly as a sheet or film in a tape product. Background Art

[0002] Conventional tapes and adhesives (and combinations thereof) as well as packaging materials such as air cushions can be made of or contain a large amount of polyolefins, which are typically petroleum-based polyolefins. Due to environmental concerns about greenhouse gas emissions and a high dependence on depleting petroleum-based resources, most industries are facing changing global trends, and thus a strong sustainable development strategy is needed to manufacture better tapes and adhesives, such as air cushions, tapes, and their adhesives that are compostable, recyclable, and / or repulpable. Summary of the Invention

[0003] In one example, a tape is provided that includes: a repulpable backing having a first major surface and an opposite second major surface; a repulpable reinforcement adjacent to the second major surface; and an adhesive layer adjacent to the repulpable reinforcement. In one aspect, alone or in combination with any of the foregoing aspects, the tape is at least 80 wt%, at least 85 wt%, or at least 90 wt% soluble in hot water or repulpable under pulping conditions, such as the FBA method discussed below.

[0004] In one aspect, the repulpable backing substantially comprises cellulose. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is paper. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is kraft paper.

[0005] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcement is adjacent to the repulpable backing. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is extruded laminated to the repulpable reinforcement. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is adhesively laminated to the repulpable reinforcement. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is adhesively laminated to the repulpable reinforcement without an adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable backing is extruded laminated to the repulpable reinforcement without an adhesive.

[0006] In one aspect, either alone or in combination with any of the foregoing aspects, the tape further comprises an optional paper layer located between the repulpable reinforcement and the adhesive. In one aspect, either alone or in combination with any of the foregoing aspects, the paper layer and the repulpable backing are the same or different.

[0007] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises unmodified starch, modified starch, synthetic starch, crosslinked starch, or a mixture of two or more thereof. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement is a film, mesh, or scrim comprising unmodified starch, modified starch, synthetic starch, crosslinked starch, or a mixture of two or more thereof. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement is at least 90 wt% soluble in hot water (e.g., 115°F to 140°F (46°C to 60°C)) or repulpable under pulping conditions.

[0008] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises unmodified starch, modified starch, synthetic starch, or crosslinked starch derived from cassava, corn, potato, sweet potato, sago, tapioca starch, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, dent, or peas.

[0009] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises unmodified starch, modified starch, synthetic starch, or crosslinked starch derived from glutinous rice, waxy potato starch, and waxy corn.

[0010] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement is an extruded mesh, film, or layer. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises starch, modified starch, synthetic starch, thermoplastic starch, or a combination thereof.

[0011] In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a starch having a combined weight ratio of amylose to amylopectin of from 10:90 to 90:10. In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a modified starch having a combined weight ratio of amylose to amylopectin of from 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a synthetic starch having a combined weight ratio of amylose to amylopectin of from 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a thermoplastic starch having a combined weight ratio of amylose to amylopectin of from 40:60 to 0:100.

[0012] In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a starch blend having a combined weight ratio of amylose to amylopectin of from 40:60 to 0:100, wherein the starch blend comprises unmodified starch, modified starch, synthetic starch, thermoplastic starch, or a combination thereof.

[0013] In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcing agent comprises a starch blend comprising a combination of a first starch and a second starch, the first starch having a weight ratio of amylose to amylopectin of from 40:60 to 0:100, the second starch having a weight ratio of amylose to amylopectin of from 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, synthetic, or crosslinked.

[0014] In one aspect, alone or in combination with any of the foregoing aspects, the weight ratio of starch to water-soluble material is from 50:1 to 1:50. In one aspect, alone or in combination with any of the foregoing aspects, the one or more redispersible materials are polyvinyl alcohol or polyvinyl alcohol copolymers and their salts, polyethyleneimine, polyvinylpyrrolidone, polyalkylene oxides, polyhydroxyalkanoates, polyacrylamides, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetate, polyamides, poly(meth)acrylic acid, poly(meth)acrylate and their salts, gelatin, methylcellulose, carboxymethylcellulose, microfibrillated cellulose, nanofibrillated cellulose and their blends and / or their salts, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, natural sugar alcohols and synthetic sugar alcohols, dextrin, maltodextrin, guar gum, gum arabic, gum arabic, xanthan gum, carrageenan, alginate, locust bean gum, gellan gum, their copolymers, their blends, and their combinations.

[0015] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises a combination of starch or modified starch with polyvinyl alcohol or a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises a combination of starch or modified starch with polyvinyl alcohol having a degree of saponification of 80 mol% to 99.8 mol%.

[0016] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises a combination of starch or modified starch with a polyvinyl alcohol copolymer comprising one or more anionic monomers.

[0017] In one aspect, alone or in combination with any of the foregoing aspects, the one or more anionic monomers are independently selected from vinyl acetic acid, maleic acid, monoalkyl maleate, dialkyl maleate, monomethyl maleate, dimethyl maleate, maleic anhydride, fumaric acid, monoalkyl fumarate, dialkyl fumarate, monomethyl fumarate, dimethyl fumarate, fumaric anhydride, itaconic acid, monomethyl itaconate, dimethyl itaconate, itaconic anhydride, vinylsulfonic acid, allylsulfonic acid, ethenesulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methylacrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, alkali metal salts of the foregoing, esters of the foregoing, and combinations thereof.

[0018] In one aspect, alone or in combination with any of the foregoing aspects, the tape further comprises one or more components selected from the group consisting of: plasticizers, plasticizer compatibilizers, lubricants, release agents, fillers, extenders, impact modifiers, crosslinking agents, anti-blocking agents, antioxidants, debonding agents, defoaming agents, nanoparticles, bleaching agents, surfactants, biocides, and combinations or reaction products thereof. In one example, the filler includes microfibrillated cellulose, nanofibrillated cellulose, and mixtures thereof in any proportion.

[0019] In one aspect, alone or in combination with any of the foregoing aspects, the adhesive layer is a water-activated adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive is adjacent to the repulpable reinforcement.

[0020] In one aspect, alone or in combination with any of the foregoing aspects, the tape further comprises a paper layer located between the repulpable reinforcement and the adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive is adjacent to the paper layer. In one aspect, alone or in combination with any of the foregoing aspects, the paper layer and the repulpable backing are the same or different.

[0021] In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive is a polyvinyl acetate emulsion adhesive, a polyvinyl acetate ethylene adhesive, a poly(meth)acrylic acid or poly(meth)acrylic acid emulsion adhesive, a starch-based adhesive, or a combination or laminate thereof.

[0022] In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive is a starch-based adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive is a starch-based adhesive combined with an acrylamide-based adhesive or an acrylic-based adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the water-activated adhesive contains a filler.

[0023] In one aspect, alone or in combination with any of the foregoing aspects, the adhesive layer is a pressure-sensitive adhesive.

[0024] In one aspect, alone or in combination with any of the foregoing aspects, the adhesive is foamed. In one aspect, alone or in combination with any of the foregoing aspects, the strip is disposed in a roll.

[0025] In one example, a method for producing a strip is provided, the method comprising: continuously or semi-continuously mixing a quantity of starch and an added amount of water in one state with a repulpable material in a low-shear extruder or mixing device under heating conditions to obtain a mixture; continuously or semi-continuously extruding the mixture; and cooling the mixture.

[0026] In one aspect, the method further comprises pre-treating the starch before heating in the low-shear extruder.

[0027] In one aspect, the method further comprises continuously producing a film from the mixture and bringing the film into contact with a second major surface of the repulpable backing.

[0028] In one aspect, alone or in combination with any of the foregoing aspects, high solids are continuously or semi-continuously mixed to obtain a starch having a high solids content, wherein the high solids content is 25 wt% to 75 wt% of the starch. In one aspect, alone or in combination with any of the foregoing aspects, the method further comprises applying an adhesive composition adjacent to the repulpable reinforcement. In one aspect, alone or in combination with any of the foregoing aspects, the method further comprises applying an adhesive composition in close proximity to the repulpable reinforcement.

[0029] In one aspect, alone or in combination with any of the foregoing aspects, the method further comprises foaming the adhesive. In one aspect, alone or in combination with any of the foregoing aspects, the method further comprises forming granules from the mixture.

[0030] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises remelting the pellets into a melt, producing a film from the melt, and extruding and laminating the film onto a second major surface of the repulpable backing.

[0031] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises remelting the pellets into a melt, producing a film from the melt, extruding and laminating the film onto a second major surface of the repulpable backing, and applying an adhesive composition adjacent to the repulpable reinforcement.

[0032] In one aspect, either alone or in combination with any of the foregoing aspects, the total amount of water in one state added is 10% to 50% by mass of the mixture. In one aspect, either alone or in combination with any of the foregoing aspects, the water in one state is liquid, vapor, or a combination of liquid and vapor.

[0033] In one aspect, either alone or in combination with any of the foregoing aspects, heating is carried out at a temperature below 200 °C or below 210 °C during mixing.

[0034] In one aspect, either alone or in combination with any of the foregoing aspects, the contact of the film with the second major surface of the repulpable backing is continuous. In one aspect, either alone or in combination with any of the foregoing aspects, the mixture is extruded as a continuous web, film, or layer. In one aspect, either alone or in combination with any of the foregoing aspects, a spinneret die, a slot die, an annular die, a coextrusion die, or a combination thereof is used to extrude the melt.

[0035] In one aspect, either alone or in combination with any of the foregoing aspects, the melt is adhesively laminated to the repulpable backing before or after cooling. In one aspect, either alone or in combination with any of the foregoing aspects, the adhesive composition is applied to the repulpable reinforcement as a continuous web, sheet, or layer. In one aspect, either alone or in combination with any of the foregoing aspects, a spinneret die, a slot die coater, a curtain coater, a rotor nip coater, a reverse roll, a roll-over-roll coating, and a knife-over-roll coating are used to apply the adhesive composition to the repulpable reinforcement. In one aspect, either alone or in combination with any of the foregoing aspects, the adhesive composition is applied randomly or in a pattern.

[0036] In one aspect, either alone or in combination with any of the foregoing aspects, the method further includes adding a secondary material to the mixture. In one aspect, either alone or in combination with any of the foregoing aspects, the secondary material comprises a solid raw material selected from the group consisting of: impact modifiers, tackifying resins, extenders, activators, crosslinking agents, colorants, recycled waste plastics, recycled cellulose materials, microfibrillated cellulose, nanofibrillated cellulose, clays (such as bentonite), and mixtures thereof in any proportion. In one aspect, either alone or in combination with any of the foregoing aspects, the secondary material comprises recycled materials. In one aspect, either alone or in combination with any of the foregoing aspects, the secondary material further comprises an activator and an extender, the activator being selected from zinc oxide, azides, epoxides, sodium tetraborate, magnesium oxide, and combinations thereof, and the extender being selected from clays, calcium carbonate, talc, aluminum hydroxide, and combinations thereof.

[0037] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable backing is paper. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable backing is kraft paper.

[0038] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable backing is adhesively laminated to the repulpable reinforcement. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable backing is extrusion laminated to the repulpable reinforcement. In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable backing is extrusion laminated to the repulpable reinforcement without an adhesive.

[0039] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement is at least 90 wt% soluble in hot water or repulpable under pulping conditions after cooling.

[0040] In one aspect, either alone or in combination with any of the foregoing aspects, the repulpable reinforcement comprises modified starch or synthetic starch. In one aspect, either alone or in combination with any of the foregoing aspects, the modified starch is a modified starch in which epoxidation, alkylation, carboxylation, carboxymethylation, alkyl acetylation, alkali modification, acid modification, bleaching, oxidation, enzyme treatment, phosphorylation, phosphonation, hydroxyalkylation, borax treatment, urea treatment, urea-formaldehyde treatment, resorcinol-formaldehyde treatment, heat treatment, dry heat treatment, or enzyme treatment or dextrinization has been carried out.

[0041] In one aspect, either alone or in combination with any of the foregoing aspects, the modified starch is thermoplastic starch.

[0042] In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcement comprises starch derived from cassava, corn, potato, sweet potato, sago, tapioca starch, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, dent or pea. In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcement comprises glutinous rice, waxy potato starch and waxy corn.

[0043] In one aspect, alone or in combination with any of the foregoing aspects, the starch comprises a starch blend having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the starch comprises a modified starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the starch is a modified starch blend having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the starch comprises a combination of a first starch and a second starch, the first starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, the second starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, synthetic or crosslinked.

[0044] In one aspect, alone or in combination with any of the foregoing aspects, the redispersible reinforcement comprises a combination of starch or modified starch and one or more redispersible materials. In one aspect, alone or in combination with any of the foregoing aspects, after drying, the water in the film is 2 wt% to 25 wt%.

[0045] In one aspect, alone or in combination with any of the foregoing aspects, the weight ratio of starch to water-soluble material is 50:1 to 1:50.

[0046] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable material is polyvinyl alcohol or a polyvinyl alcohol copolymer and its salts, polyvinylimine, polyvinylpyrrolidone, polyalkylene oxide, polyhydroxyalkanoate, polyacrylamide, cellulose ether, cellulose ester, cellulose amide, polyvinyl acetate, polyamide, gelatin, poly(meth)acrylic acid, poly(meth)acrylate and its salts, methylcellulose, carboxymethylcellulose and its salts, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, microfibrillated cellulose, modified microfibrillated cellulose, nanofibrillated cellulose, modified nanofibrillated cellulose, sugar alcohol, dextrin, maltodextrin, guar gum, gum arabic, gum acacia, xanthan gum, carrageenan, alginate, locust bean gum, gellan gum, their copolymers, their blends, and their combinations.

[0047] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcing agent comprises a combination of starch or modified starch with polyvinyl alcohol or a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcing agent comprises a combination of starch or modified starch with polyvinyl alcohol and a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcing agent comprises a combination of starch and modified starch with polyvinyl alcohol and a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcing agent comprises a combination of starch or modified starch with polyvinyl alcohol or a polyvinyl alcohol copolymer having a saponification degree of 80 mol% to 99.8 mol%.

[0048] In one aspect, alone or in combination with any of the foregoing aspects, the repulpable reinforcing agent comprises a combination of starch and / or modified starch with polyvinyl alcohol and / or a polyvinyl alcohol copolymer comprising one or more anionic monomers. In one aspect, alone or in combination with any of the foregoing aspects, the one or more anionic monomers are independently selected from vinyl acetic acid, maleic acid, monoalkyl maleate, dialkyl maleate, monomethyl maleate, dimethyl maleate, maleic anhydride, fumaric acid, monoalkyl fumarate, dialkyl fumarate, monomethyl fumarate, dimethyl fumarate, fumaric anhydride, itaconic acid, monomethyl itaconate, dimethyl itaconate, itaconic anhydride, vinyl sulfonic acid, allyl sulfonic acid, ethene sulfonic acid, 2-acrylamido-1-methylpropane sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 2-methylacrylamido-2-methylpropane sulfonic acid, 2-sulfoethyl acrylate, the alkali metal salts of the foregoing substances, the esters of the foregoing substances, and their combinations.

[0049] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises a component selected from one or more of the following: an impact modifier, a plasticizer, a plasticizer compatibilizer, a lubricant, a release agent, a filler, microfibrillated cellulose, modified microfibrillated cellulose, nanofibrillated cellulose, modified nanofibrillated cellulose, a sugar alcohol, dextrin, maltodextrin, clay, a biocide, a wetting agent, an extender, a crosslinking agent, an anti-blocking agent, an antioxidant, a debonding agent, an antifoaming agent, nanoparticles, a bleaching agent, a surfactant, and combinations or reaction products thereof.

[0050] In one aspect, either alone or in combination with any of the foregoing aspects, the adhesive layer is a water-activated adhesive. In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises introducing an optional re-slurryable layer between the re-slurryable reinforcement and the adhesive. In one aspect, either alone or in combination with any of the foregoing aspects, the water-activated adhesive is adjacent to the re-slurryable reinforcement. In one aspect, either alone or in combination with any of the foregoing aspects, the paper layer and the re-slurryable backing are the same or different.

[0051] In one aspect, either alone or in combination with any of the foregoing aspects, the water-activated adhesive is a polyvinyl acetate emulsion adhesive, a poly(vinyl acetate) adhesive, a polyacrylic acid or poly(meth)acrylic acid emulsion adhesive, a starch-based adhesive, or a combination or laminate thereof.

[0052] In one aspect, either alone or in combination with any of the foregoing aspects, the water-activated adhesive is a starch-based adhesive. In one aspect, either alone or in combination with any of the foregoing aspects, the adhesive layer is a pressure-sensitive adhesive.

[0053] In one aspect, either alone or in combination with any of the foregoing aspects, the water-activated adhesive comprises a filler. In one aspect, either alone or in combination with any of the foregoing aspects, the adhesive is foamed.

[0054] In one aspect, either alone or in combination with any of the foregoing aspects, as measured by GPC or viscosity, the average molecular weight of the starch is reduced by less than 50%. In one aspect, either alone or in combination with any of the foregoing aspects, as measured by GPC, the average molecular weight of the starch is reduced by less than 20%. In one aspect, either alone or in combination with any of the foregoing aspects, as measured by GPC, the average molecular weight of the starch is reduced by less than 10%.

[0055] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises crosslinking the adhesive composition. In one aspect, either alone or in combination with any of the foregoing aspects, the crosslinked adhesive composition uses a method selected from the following: EB crosslinking, UV crosslinking, thermal and / or chemical crosslinking, and combinations thereof.

[0056] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises contacting a film of the composition with a paper backing. In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises applying an adhesive to the film of the composition. In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises introducing an optional redispersible layer into the film of the composition. In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises applying an adhesive to the paper layer.

[0057] In another example, a film is provided that comprises: starch; and an amount of redispersible material.

[0058] In one aspect, the starch film is at least 90 wt% soluble in hot water or redispersible under pulping conditions, such as the FBA method. In one aspect, either alone or in combination with any of the foregoing aspects, the starch present in the film is alkyl etherified starch, carboxyalkyl etherified starch, hydroxyalkyl etherified starch having a hydroxyalkyl group containing 2 to 6 carbon atoms, and synthetic starch. In one aspect, either alone or in combination with any of the foregoing aspects, the starch present in the film is thermoplastic starch.

[0059] In one aspect, either alone or in combination with any of the foregoing aspects, the starch present in the film is derived from cassava, corn, potato, sweet potato, sago, tapioca, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, dent, or pea. In one aspect, either alone or in combination with any of the foregoing aspects, the starch present in the film is glutinous rice, waxy potato starch, and waxy corn.

[0060] In one aspect, either alone or in combination with any of the foregoing aspects, the starch comprises a weight ratio of amylose to amylopectin of 10:90 to 90:10. In one aspect, either alone or in combination with any of the foregoing aspects, the starch includes a starch blend having a combined weight ratio of amylose to amylopectin of 10:90 to 90:10.

[0061] In one aspect, alone or in combination with any of the foregoing aspects, the starch comprises a modified starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the starch is a blend of modified starches having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100. In one aspect, alone or in combination with any of the foregoing aspects, the starch comprises a combination of a first starch and a second starch, the first starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, the second starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, synthetic, or crosslinked.

[0062] In one aspect, alone or in combination with any of the foregoing aspects, the re-pulpable material is polyvinyl alcohol or a polyvinyl alcohol copolymer and its salts, polyvinylimine, polyvinylpyrrolidone, polyalkylene oxide, polyhydroxyalkanoate, polyacrylamide, cellulose ether, cellulose ester, cellulose amide, polyvinyl acetate, polyamide, gelatin, poly(meth)acrylic acid, poly(meth)acrylate and its salts, methylcellulose, carboxymethylcellulose and its salts, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, microfibrillated cellulose, modified microfibrillated cellulose, nanofibrillated cellulose, modified nanofibrillated cellulose, sugar alcohol, dextrin, maltodextrin, clay, biocide, wetting agent, dextrin, maltodextrin, guar gum, gum arabic, xanthan gum, carrageenan, their copolymers, their blends, and their combinations.

[0063] In one aspect, alone or in combination with any of the foregoing aspects, the re-pulpable material is polyvinyl alcohol or a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the re-pulpable material is a combination of polyvinyl alcohol and a polyvinyl alcohol copolymer. In one aspect, alone or in combination with any of the foregoing aspects, the polyvinyl alcohol has a saponification degree of 80 mol% to 99.8 mol%.

[0064] In one aspect, alone or in combination with any of the foregoing aspects, the polyvinyl alcohol copolymer comprises one or more anionic monomers. In one aspect, alone or in combination with any of the foregoing aspects, the one or more anionic monomers are independently selected from vinyl acetic acid, maleic acid, monoalkyl maleate, dialkyl maleate, monomethyl maleate, dimethyl maleate, maleic anhydride, fumaric acid, monoalkyl fumarate, dialkyl fumarate, monomethyl fumarate, dimethyl fumarate, fumaric anhydride, itaconic acid, monomethyl itaconate, dimethyl itaconate, itaconic anhydride, vinylsulfonic acid, allylsulfonic acid, ethenesulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methylacrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, the alkali metal salts of the foregoing substances, the esters of the foregoing substances, and combinations thereof.

[0065] In one aspect, alone or in combination with any of the foregoing aspects, the film further comprises one or more components selected from the following: impact modifiers, plasticizers, plasticizer compatibilizers, lubricants, mold release agents, fillers, microfibrillated cellulose, modified microfibrillated cellulose, nanofibrillated cellulose, modified nanofibrillated cellulose, sugar alcohols, dextrin, maltodextrin, clay, biocides, wetting agents, extenders, crosslinking agents, antiblocking agents, antioxidants, debonding agents, defoaming agents, nanoparticles, bleaching agents, surfactants, and combinations or reaction products thereof.

[0066] In one aspect, alone or in combination with any of the foregoing aspects, the weight ratio of starch to the repulpable material is from 50:1 to 1:50.

[0067] In another example, a method for producing a starch film composition is provided, the method comprising: metering the starch film composition continuously or semi-continuously into a low-shear extrusion device (such as a planetary roller extruder), the starch film composition comprising starch, modified starch, thermoplastic starch, or combinations thereof, water in one state, and a repulpable material; continuously mixing the composition in the compounding section of the low-shear extrusion device; and continuously discharging the starch film from the extruder.

[0068] In one aspect, the compounding sections comprise a plurality of roller cylinder sections. In one aspect, alone or in combination with any of the foregoing aspects, each roller cylinder section comprises a plurality of mixing shafts.

[0069] In one aspect, alone or in combination with any of the foregoing aspects, the method further comprises adding the water in one state to the composition in the compounding section. In one aspect, alone or in combination with any of the foregoing aspects, the water in one state is liquid, vapor, or a combination of liquid and vapor. In one example, the starch is pretreated.

[0070] In one aspect, either alone or in combination with any of the foregoing aspects, the method further comprises adding a secondary raw material to the compounding section. In one aspect, either alone or in combination with any of the foregoing aspects, the secondary raw material comprises a solid, liquid or gaseous material. In one aspect, either alone or in combination with any of the foregoing aspects, the solid material is selected from thermoplastic elastomers, resins, extenders, activators, anti-degradants, biocides, wetting agents, foaming agents, cross-linking agents, and mixtures thereof.

[0071] In one aspect, either alone or in combination with any of the foregoing aspects, the compounding section further comprises a dosing unit, and the solid material is added to the compounding section via the dosing unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] To understand and appreciate how the present disclosure may be implemented in practice, embodiments will now be described by way of non-limiting example only with reference to the accompanying drawings, in which:

[0073] Figure 1A is a perspective view of a strip roll for one embodiment of the present disclosure;

[0074] Figure 1B is Figure 1A an enlarged cross-sectional view of the strip of Figure 1A showing the layers along line 2-2 of

[0075] Figure 2A is a perspective view of a strip roll for one embodiment of the present disclosure;

[0076] Figure 2B is Figure 2A an enlarged cross-sectional view of the strip of Figure 2A showing the layers along line 3-3 of

[0077] Figure 3A is a perspective view of a strip roll for one embodiment of the present disclosure.

[0078] Figure 3B is Figure 3A an enlarged cross-sectional view of the strip of Figure 3A showing the layers along line 4-4 of

[0079] Figure 4 is a longitudinal cross-sectional view of a low-shear extrusion device according to one aspect of the present disclosure;

[0080] Figure 5 is an enlarged view of an exemplary double transverse mixing shaft;

[0081] Figure 6 is from Figure 4Cross-sectional view of the dosing ring of the low-shear extrusion device in

[0082] Figure 7 is a cross-sectional view of a slot die coater;

[0083] Figure 8 is a longitudinal cross-sectional view of an exemplary low-shear extrusion device and a slot die coater according to one aspect of the present invention; and

[0084] Figure 9 is a cross-sectional view of the exemplary low-shear extrusion device in FIG. 1 along line 6-6. Detailed Description

[0085] The present disclosure provides compounding and / or extrusion of starch-containing films.

[0086] In one aspect, the present disclosure provides compounding and / or extrusion of amylose-containing or substantially amylose-free starch. In one aspect, the present disclosure provides starch containing less than 40 wt%, less than 30 wt%, less than 20 wt%, less than 10 wt%, less than 9 wt%, less than 8 wt%, less than 7 wt%, less than 6 wt%, less than 5 wt%, less than 4 wt%, less than 3 wt%, less than 2 wt%, less than 1 wt% amylose (substantially all amylopectin) for compounding and / or extrusion.

[0087] In one aspect, the present disclosure provides compounding and / or extrusion of high amylopectin content alone or in combination with other additives, and is processed in a manner that substantially maintains the molecular weight and branching of amylopectin. The compounding / extrusion applications of such starch materials can be applied to packaging applications, for example, to provide a tough film capable of enhancing water-activated tapes (WAT), and to provide films used as: stretch films, shrink films, pipe tape backings, polyolefin tapes, air pillows / air cushions, bubble cushions used alone or in mail. Additionally, the compounding / extrusion applications of such starch materials and the preparation of films or sheets are suitable for sachets, such as those currently used for condiments, health / hygiene, and detergent boxes. Furthermore, by balancing the amylose / amylopectin ratio, and / or in combination with controlling the molecular weight change and / or branching of starch during compounding and / or extrusion, the compounding / extrusion applications of such starch materials can be used to address the water sensitivity requirements of certain applications.

[0088] Such starch films / sheets as disclosed herein can be used to provide substrates for receiving CVD / PVD SiOx and / or AlOx coatings with improved air / water barrier properties. Such starch materials as disclosed herein are configured to receive paints or varnishes. Such starch films / sheets as disclosed herein can include plasticizers, fillers, other polymers, biocides, wetting agents, UV stabilizers, etc.

[0089] In one example, a starch composition produced using a low-shear extrusion device and products made therefrom are provided. Such products provide for sustainable or recyclable and / or repulpable products, which can be used alone or in combination with packaging that is also sustainable or recyclable and / or repulpable.

[0090] As used herein, the phrase "water-activated adhesive" includes adhesives that are generally not sticky when dry but become sticky upon exposure to an aqueous medium, where the aqueous medium includes water and optionally other solvents such as alcohols.

[0091] As used herein, the phrase "a state of water" includes water in a solid, liquid, or gas and / or vapor state. The state of water can include additional solvents (such as alcohols) and other unintentional impurities.

[0092] As used herein, "starch" and "comprising starch" include any synthetic starch or plant starch, or blends thereof, as well as combinations, blends, or grafts with one or more polymers. As used herein, "plant starch" refers to starch isolated, 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, legumes, barley, rice, dent, peas, and / or potatoes. Plant starches and non-plant starches from other sources can be employed.

[0093] As used herein, synthetic starch includes "modified plant starch", such as any plant starch modified chemically, genetically, enzymatically, mechanically, and / or thermally. As used herein, synthetic starch also includes non-plant starch, such as starch prepared from carbon dioxide.

[0094] As used herein, "modified starch" includes epoxidized, alkylated, carboxylated, carboxymethylated, alkyl acetylated, base-modified, bleached, oxidized, enzyme-treated, phosphorylated, phosphated, hydroxyalkylated, borax-treated, urea-treated, urea-formaldehyde-treated, resorcinol-formaldehyde-treated, heat-treated, dry heat-treated, acid-treated, or enzyme-thinned or dextrinized starch.

[0095] As used herein, the term "repulpable" is included in the voluntary standard for repulping and recycling corrugated fiberboard of the Fiber Box Association in 2013, which is designed to improve the performance of corrugated fiberboard in the presence of water and water vapor (the "FBA method").

[0096] As used herein, "repulpable materials" include polyvinyl alcohol or polyvinyl alcohol copolymers and their salts, polyethyleneimine, polyvinylpyrrolidone, polyalkylene oxides, polyhydroxyalkanoates, polyacrylamides, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetate, polyamides, poly(meth)acrylic acids, poly(meth)acrylates and their salts, gelatin, methylcellulose, carboxymethylcellulose and its salts, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, dextrin, maltodextrin, guar gum, gum arabic, gum arabic, xanthan gum, carrageenan, alginate, locust bean gum, gellan gum, their copolymers, their blends, carbohydrates, proteins, lipids, triglycerides and phospholipids alone or in combination with any of the foregoing.

[0097] As a non-limiting example, low-shear extrusion equipment includes planetary roller extruders (PREs), planetary roller mixers, twin-screw extruders configured with counter-rotating or co-rotating, meshing or non-meshing screws, static mixing devices, etc. PREs are commonly used in the processing of thermoplastics such as PVC, for example, where they are mainly used to supply downstream units such as cast or blown film devices, calenders or roll mills. Planetary roller extruders can be used to process heat-sensitive compounds in a manner that minimizes degradation, for example by promoting the exposure of thin layers of the compound to a large surface area, resulting in efficient heat exchange, mixing and temperature control. Planetary roller extruders are available in a variety of designs and sizes. The diameter of the guide rollers depends on the desired production rate and is typically from 30 mm to 1000 mm, or from 70 mm to 500 mm.

[0098] Planetary roller extruders typically have a filling section and a compounding section. The filling section typically includes a conveying screw to which certain raw materials are continuously fed. The conveying screw then transfers the material to the compounding section. The compounding section includes a driven main shaft and a plurality of planetary shafts that rotate around the main shaft within a guide roller having internal helical gears. The rotational speed of the main shaft and thus the rotational speed of the planetary shafts can vary and is a parameter that needs to be controlled during the compounding process. The material circulates between the main shaft and the planetary shafts, or between the planetary shafts and the helical gears of the roller section, such that the underlying material is dispersed to form a homogeneous composition.

[0099] The number of planetary shafts rotating in each guide roll can be varied to suit the requirements of the process. The number of shafts affects the free volume within the planetary roller extruder, the residence time of the material in the process, and also determines the surface area available for heat and material exchange. Through the introduced dispersive energy, the number, geometry, and / or configuration of the planetary shafts all have an impact on the compounding result. With a constant diameter of the guide roll, a larger number of shafts allows for better homogenization and dispersion, or respectively a higher production rate of the product.

[0100] The maximum number of planetary shafts that can be installed between the main shaft and the guide roll depends on the diameter of the guide roll and the diameter of the planetary shafts used. When using a relatively large cylinder diameter (as required for production-scale throughput) and / or a relatively small planetary shaft diameter, these guide rolls can be equipped with a relatively large number of planetary shafts. For example, in the case of a cylinder diameter D = 70 mm, up to 7 planetary shafts are typically used, while in the case of a cylinder diameter D = 200 mm, 10 planetary shafts can be used, and in the case of a cylinder diameter D = 400 mm, 24 planetary shafts can be used. However, these embodiments are in no way limiting to those skilled in the art. For example, if the diameter of the main shaft is relatively small compared to a larger main shaft, the number of planetary shafts can be increased. Similarly, if the diameter of the main shaft is relatively large compared to a larger main shaft, the number of planetary shafts can be decreased.

[0101] Now turning to the drawings and first referring Figure 1A to, a roll 200 of a strip 130 wound around a core 118, the strip roll substantially having a paper backing 124 and a starch-containing reinforcement 122. Referring Figure 1A and Figure 1B for explanation, relative to the page from top to bottom, the strip 130 includes the paper backing 124. The paper backing 124 (also referred to as the substrate) has a first major (top) surface 132, a second major (bottom) surface 134, and first and second side surfaces. As shown, applied to the bottom surface 134 of the backing 124 is the starch-containing reinforcement 122. The starch-containing reinforcement 122 is configured to act as an adhesive, such as a water-activated adhesive. For example, the starch-containing reinforcement 122 can be activated using an aqueous medium such as water or water and alcohol before use. In one example, the starch-containing reinforcement 122 is a film, mesh, scrim, or layer.

[0102] Referring Figure 2A to, a roll 300 of a strip 130 wound around a core 118 is shown, the strip roll substantially having a paper backing 124, a starch-containing reinforcement 122, and an adhesive 114. Referring Figure 2A and Figure 2BFor explanation, with respect to the page from top to bottom, the tape 130 includes a paper backing 124. The paper backing 124 (also referred to as the substrate) has a first major (top) surface 132, a second major (bottom) surface 134, and first and second side surfaces. As shown, the starch-containing reinforcement 122 is positioned adjacent to the paper backing 124, and the adhesive 114 is applied to the opposite surface of the starch-containing reinforcement 122. In one example, the adhesive 114 is a water-activated adhesive. In another example, the adhesive 114 is a pressure-sensitive adhesive.

[0103] Reference Figure 3A , a roll 400 of the tape 130 wound around the core 118, the tape roll substantially having a paper backing 124, a starch-containing reinforcement 122, a paper layer 112, and an adhesive 114. Reference Figure 3A and Figure 3B For explanation, with respect to the page from top to bottom, the tape 130 includes a paper backing 124. The paper backing 124 (also referred to as the substrate) has a first major (top) surface 132, a second major (bottom) surface 134, and first and second side surfaces. As shown, the starch-containing reinforcement 122 is positioned adjacent to the paper backing 124. As Figure 3A , Figure 3B shown, an additional paper layer 112 is positioned adjacent to the opposite surface of the starch-containing reinforcement 122. The adhesive 114 is applied to the opposite surface of the paper layer 112. In one example, the adhesive 114 is a water-activated adhesive. In another example, the adhesive 114 is a pressure-sensitive adhesive. In another example, the adhesive 114 is a re-sloshing pressure-sensitive adhesive. In another example, the adhesive 114 is a heat-activated adhesive. In another example, the adhesive 114 is a re-sloshing heat-activated adhesive.

[0104] In one example, the backing 124 and the starch-containing reinforcement 122 are extrusion laminated. In one example, the backing 124 and the starch-containing reinforcement 122 are extrusion laminated without additional materials. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly laminated to the paper backing 124. In another example, the backing 124 and the starch-containing reinforcement 122 are extrusion laminated together, and there is a softened or molten layer between them that laminates these layers together, and the softened or molten layer solidifies once it solidifies. The softened or molten layer can be extruded between the backing 124 and the starch-containing reinforcement 122, or co-extruded with the starch-containing reinforcement 122.

[0105] In one example, the backing 124 and the starch-containing reinforcement 122 are adhesively laminated. In one example, the backing 124 and the starch-containing reinforcement 122 are adhesively laminated without an adhesive. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly adhered to the paper backing 124. In another example, the backing 124 and the starch-containing reinforcement 122 are adhesively laminated together with one or a discontinuous pattern of adhesive between them that bonds these layers together. The adhesive can be extruded between the backing 124 and the starch-containing reinforcement 122 or co-extruded with the starch-containing reinforcement 122.

[0106] Referring to roller 300, in one example, the adhesive 114 and the starch-containing reinforcement 122 are extrusion laminated. In one example, the adhesive 114 and the starch-containing reinforcement 122 are extrusion laminated without additional material. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly laminated to the adhesive 114. In another example, the adhesive 114 and the starch-containing reinforcement 122 are extrusion laminated together with a softened or molten layer between them that laminates these layers together and solidifies once it sets. The softened or molten layer can be extruded between the adhesive 114 and the starch-containing reinforcement 122 or co-extruded with the starch-containing reinforcement 122.

[0107] In one example, the adhesive 114 and the starch-containing reinforcement 122 are adhesively laminated. In one example, the adhesive 114 and the starch-containing reinforcement 122 are adhesively laminated without an adhesive. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly adhered to the adhesive 114. In another example, the adhesive 114 and the starch-containing reinforcement 122 are adhesively laminated together with one or a discontinuous pattern of adhesive between them that bonds these layers together. The adhesive can be extruded between the adhesive 114 and the starch-containing reinforcement 122 or co-extruded with the starch-containing reinforcement 122.

[0108] Referring to roller 400, in one example, the backing 124 and the starch-containing reinforcement 122 are extruded and laminated. In one example, the backing 124 and the starch-containing reinforcement 122 are extruded and laminated without additional materials. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly laminated to the paper backing 124. As shown, the roller 400 further includes a paper layer 112 adjacent to the opposite side of the starch-containing reinforcement 122. In one example, the paper layer 112 and the starch-containing reinforcement 122 are extruded and laminated. In one example, the paper layer 112 and the starch-containing reinforcement 122 are extruded and laminated without additional materials. For example, one surface of the starch-containing reinforcement 122 is activated (e.g., with a certain state of water) and directly laminated to the paper layer 112.

[0109] In one example, the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112 are extruded and laminated together. In one example, the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112 are extruded and laminated together without additional materials. For example, two surfaces of the starch-containing reinforcement 122 are activated (e.g., with a certain state of water) and directly laminated to the paper backing 124 and the paper layer 112. The adhesive 114 is positioned adjacent to the opposite surface of the paper layer 112. In one example, the adhesive 114 is extruded and laminated to the paper layer 112. In another example, the adhesive 114 is adhesively laminated to the paper layer 112.

[0110] In one example, the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112 are adhesively laminated. In one example, the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112 are adhesively laminated without an adhesive. For example, two surfaces of the starch-containing reinforcement 122 are activated (e.g., with a certain state of water) and directly adhered to the paper backing 124 and the paper layer 112. In another example, the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112 are adhesively laminated together with one or a discontinuous pattern of adhesives that bond one or more or all of these layers together. The adhesive can be extruded between one or more of the paper backing 124, the starch-containing reinforcement 122, and the paper layer 112, or co-extruded with the starch-containing reinforcement 122.

[0111] In one example, the adhesive 114 of the roller 400 is directly extruded or adhesively laminated to the paper layer 112. In another example, the adhesive 114 and the paper layer 112 are adhesively laminated together with one or a discontinuous pattern of adhesives that bond these layers together. The adhesive can be extruded between the adhesive 114 and the starch-containing reinforcement 122, or co-extruded with the starch-containing reinforcement 122.

[0112] The above processing steps of the rollers 200, 300 or 400 can be carried out continuously, semi - continuously or batch - wise.

[0113] Optionally, a release layer is applied to the top surface of the paper backing 124. In one example, the rollers 200, 300, 400 do not have a release layer.

[0114] Examples of the above - mentioned enhanced starches include starches derived from cassava, corn, potato, sweet potato, sago, tapioca starch, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, pea, etc. In one example, starches derived or modified from corn or cassava are used. In another example, starches derived or modified from high - amylose corn are used.

[0115] The enhanced starch can be a single substance, or can be a mixture of the following: two or more starches, two or more modified starches, modified starch and unmodified starch, cross - linked starch, cross - linked starch combined with one or more modified starches, or uncross - linked starch. In one embodiment, the enhanced starch is derived from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent and / or potato. In one embodiment, the enhanced starch is derived from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent and / or potato. In one embodiment, the enhanced starch is a blend of unmodified starch and modified starch, and the unmodified starch and modified starch are selected from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, pea and / or potato. In one embodiment, the enhanced starch is a blend of two or more starches, and the two or more starches are independently selected from unmodified starch, modified starch or cross - linked starch of corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, pea and / or potato. In one embodiment, the enhanced starch is a blend of two or more starches and one or more synthetic starches, and the two or more starches are independently selected from unmodified starch, modified starch or cross - linked starch of corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, pea and / or potato.

[0116] In one example, the amylopectin content of the starch or modified starch is 50% by mass or higher, 55% by mass or higher, 60% by mass or higher, 70% by mass or higher, 80% by mass or higher, 90% by mass or higher. In one example, the amylose content of the starch or modified starch is 50% by mass or higher, 55% by mass or higher, 60% by mass or higher, 70% by mass or higher, 80% by mass or higher, 90% by mass or higher.

[0117] Independently, for starch, modified starch or synthetic starch, an amylose to amylopectin weight ratio of 40:60 to 0:100 can be employed. A starch blend having an amylopectin weight ratio of 40:60 to 0:100 can be employed. A modified starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, or a modified starch blend having a combined amylose to amylopectin weight ratio of 40:60 to 0:100 can be employed. A combination of a first starch and a second starch can be employed, the first starch having an amylose to amylopectin weight ratio of 40:60 to 0:100 and the second starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, synthetic or crosslinked.

[0118] Examples of modified starches include alkyl etherified starches (such as methyl etherified starch), carboxyalkyl etherified starches (such as carboxymethyl etherified starch), and hydroxyalkyl etherified starches (such as etherified starches having a hydroxyalkyl group containing 2 to 6 carbon atoms), among others. Alternatively, allyl etherified starches, etc. can also be used as modified starches.

[0119] Additional examples of modified starches include esterified starches having structural units derived from carboxylic acids, such as esterified starches having structural units derived from acetic acid; esterified starches having structural units derived from dicarboxylic anhydrides, such as esterified starches having structural units derived from maleic anhydride, esterified starches having structural units derived from phthalic anhydride, and esterified starches having structural units derived from octenyl succinic anhydride; esterified starches having structural units derived from oxyacids, such as nitrated starches, phosphorylated starches, and urea-phosphorylated starches. Other examples of modified starches include xanthated starches, acetoacetylated starches, etc. Alkoxysilane / siloxane TEOS, etc.

[0120] Examples of crosslinked starches include formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, phosphoric acid crosslinked starch, acrolein crosslinked starch, sodium tetraborate crosslinked starch, etc.

[0121] In one example, a starch or modified starch film, web, scrim or layer in a dry state contains a water content of about 10 mass% to 25 mass%, or about 20 mass% to 25 mass%, as determined by ASTM E 203 or ISO 760.

[0122] In one example, the adhesive 114 is any conventional adhesive or an adhesive developed hereinafter that is suitable for carton sealing or carton sealing tapes (also known as packaging tapes). In one example, the adhesive 114 can be a water-activated adhesive. In one example, the adhesive 114 can be a water-activated adhesive used in conjunction with an amorphous polyolefin adhesive, a natural rubber adhesive, a poly(meth)acrylate adhesive, etc. In one example, the adhesive 114 can be mixed or blended with an amorphous polyolefin adhesive, a natural rubber adhesive, a poly(meth)acrylate adhesive, etc. In one example, the adhesive 114 can be laid on or between layers of an amorphous polyolefin adhesive, a natural rubber adhesive, a poly(meth)acrylate adhesive, etc., such as layers / membranes or patterns of pressure-sensitive adhesives and layers / membranes or patterns of water-activated adhesives, etc.

[0123] In one embodiment, the adhesive 114 is an adhesive containing starch, and the starch is derived from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, peas, and / or potatoes. In one embodiment, the adhesive 114 is an adhesive containing crosslinked starch, and the crosslinked starch contains starch derived from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, and / or potatoes. In one embodiment, the adhesive 114 is a blend of two or more adhesives independently selected from adhesives containing unmodified starch, adhesives containing modified starch, and adhesives containing crosslinked starch, and the unmodified starch, modified starch, and crosslinked starch are independently selected from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, peas, and / or potatoes. In one embodiment, the adhesive 114 is a blend of two or more adhesives independently selected from adhesives containing unmodified starch, adhesives containing modified starch, and adhesives containing crosslinked starch, and adhesives containing one or more synthetic starches and adhesives containing non-starch, and the unmodified starch, modified starch, and crosslinked starch contain starch independently selected from corn, sorghum, wheat, sago, tapioca starch, legumes, barley, rice, dent, peas, and / or potatoes. The adhesive 114 can be the same or a different composition from the starch-containing reinforcement 122.

[0124] In another embodiment, the adhesive 114 can be a re-wettable adhesive of polyvinyl alcohol, polyvinyl alcohol copolymer, or polyvinyl alcohol blend. In another embodiment, the adhesive 114 can be a blend of one or more re-wettable adhesives of polyvinyl alcohol, polyvinyl alcohol copolymer, or polyvinyl alcohol blend and any one of the above starch adhesives.

[0125] A continuous method of manufacturing a tape with a starch-containing reinforcement 122 includes providing a paper tape that includes a paper backing with an adhesive defining its bottom major surface and a starch-containing reinforcement 122 reinforcement structure opposite the adhesive of the paper backing. The film reinforcement structure provides substantially equal to or greater strength to the water-activated paper tape compared to conventional reinforcements such as cheesecloth, oriented films, PVC yarns or fibers, glass, carbon, PET, high molecular weight polyethylene, polyamides, and other engineering thermoplastics. The film reinforcement structure provides substantially equal to or greater strength to the water-activated paper tape compared to conventional reinforcements that pass the ISTA 3A and ISTA 6A tests (i.e., the tape does not tear or break while keeping the box / package closed during transportation), thus eliminating or reducing the need for other types of reinforcements. The presently disclosed film reinforcement structure can be used in combination with any of the above conventional reinforcements.

[0126] In one example, the starch-containing reinforcement 122 is adjacent to the paper backing 124 and includes coextruding the starch-containing reinforcement 122 directly onto the paper backing. The method can also include lowering the temperature of the starch-containing reinforcement 122 after extrusion and before contacting the paper backing 124.

[0127] The method can also include winding the tape onto a roll and cutting the wound tape into multiple rolls of film-laminated water-activated tape.

[0128] In another example, the continuous method of manufacturing a film-laminated tape can also include providing a paper backing 124 and applying an adhesive to its bottom major surface before coextruding the outermost polyolefin film and the laminate layer onto the paper backing.

[0129] The above tape does not require the use of filament or yarn cheesecloth reinforcements and may require only one layer of paper. This results in a tape product with uniform puncture and tear characteristics at a total cost similar to or lower than commercially available carton-sealing tapes, and produces a thinner tape that will provide a longer length for a given cylinder diameter, thus requiring fewer roll changes on the application equipment.

[0130] The film composition of the present disclosure including the tape and / or starch can also include clay. Examples of clay include synthetic and natural layered silicate clays such as montmorillonite, bentonite, beidellite, mica, lithium montmorillonite, soapstone, nontronite, zinc montmorillonite, vermiculite, ledikite, magadite, kenyaite, stevensite, volkonskoite, and mixtures thereof.

[0131] In one example, the content of the clay in the resin composition is 0.1% by mass to 5% by mass, 0.1% by mass to 3% by mass, and further 0.5% by mass to 2% by mass. When the resin composition contains the clay in an amount within the above range, there is a tendency to easily improve transparency, flexibility, tensile strength, impact resistance, and / or tensile properties.

[0132] In one example, the starch composition may contain additives, such as fillers, processing stabilizers, weather resistance stabilizers, colorants, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, flame retardants, plasticizers, other impact modifiers, lubricants, fragrances, defoamers, deodorants, bulking agents, mold release agents, die release agents, reinforcing agents, crosslinking agents, fungicides, biocides, wetting agents, preservatives, and crystallization rate retarders, as needed within a range that does not impede the effects of the present disclosure.

[0133] The starch composition can be produced in the form of pellets or films. As pellets, the starch composition can be stored and / or presented for extrusion into a film or extrusion lamination. As a film, the starch composition can be used in a multi-layer laminate that includes at least one film containing starch. Additionally, the starch film has excellent strength and is biodegradable, at least partially or substantially water-soluble, and re-pulpable, such that it can be suitable for sustainable packaging films, tapes, or packaging materials.

[0134] The tape and composition of the present disclosure can be produced by a production method that includes continuously mixing a certain amount of starch and a certain amount of water, optionally mixed with other materials, while heating in a low-shear mixer (such as a planetary rotary extruder) and obtaining an extrudate; continuously extruding the extrudate; cooling the melt to form a re-pulpable reinforced film or pellets; contacting the film (or reprocessing the pellets to form a film) with the second major surface of the re-pulpable paper backing and applying an adhesive composition adjacent to the re-pulpable reinforcement.

[0135] In one aspect, the method further includes providing a tape.

[0136] In one aspect, alone or in combination with any of the foregoing aspects, the contacting of the film with the second major surface of the re-pulpable backing is continuous.

[0137] In another example, a method for producing a starch film composition is provided, the method comprising continuously metering a starch film composition into a low-shear extrusion device, the starch film composition comprising starch, modified starch, thermoplastic starch or combinations thereof, water, and a re-slurriable material; continuously mixing the composition in a compounding section of the low-shear extrusion device, and in one aspect, individually or in combination with any one of the foregoing aspects, the compounding section includes a main shaft surrounded by and meshing with a plurality of planetary shafts, wherein at least one planetary shaft is a double transverse mixing shaft including a plurality of post-cut spiral baffles; and continuously discharging the starch film composition from the extruder.

[0138] An exemplary low-shear extrusion device according to the present disclosure is shown and is generally designated by reference numeral 10. It should be understood that the low-shear extrusion device system 10 is shown in schematic form for ease of explaining its operation in an easily understandable manner. However, in actual practice, the shape and size of the system 10 may be significantly different from those shown, but still within the scope of the claims described herein.

[0139] The low-shear extrusion device system 10 includes a feed section 12 and a compounding section 14. A primary binder raw material is added to the feed throat 16 and metered onto the conveying screw 18 of the filling section 12. As used herein, the term "primary raw material" refers to those materials of the binder formulation that are added to the feed section 12 of the low-shear extrusion device 10. The primary raw materials may include, but are not limited to, elastomers, resins, extenders, activators, anti-degradants, and cross-linking agents. The screw 18 conveys the primary raw materials into the compounding section 14. The compounding section 14 is as Figure 4 shown and includes four planetary roller cylinder sections 20a, 20b, 20c, and 20d separated by dosing rings 22a, 22b, and 22c. Each roller cylinder section 20 includes a 45° helical tooth cylinder 24, a 45° helical tooth main shaft 26, and a plurality of 45° helical tooth planetary shafts 28, 30. The helical gears can have any suitable angle, for example, an angle of 10° to 60°, and more specifically, an angle slightly greater than 20° may be useful. According to certain aspects of the present disclosure, at least one of the roller cylinder sections 20 includes a double transverse planetary shaft 28. The present disclosure is not limited to the use of double transverse planetary shafts. Other shaft configurations that provide the desired level of mixing may also be used.

[0140] The maximum number of planetary shafts 28, 30 is a function of the diameters of the main shaft 26 and the helical-tooth cylinder 24. The planetary shafts 28, 30 can exhibit many different tooth geometries, such as a full helical baffle (Planetspindel) 30, a double transverse helical baffle (also known as a back-cut shaft or Noppenspindel) 28, or a segmented helical baffle (Igelspindel), etc. The number of planetary shafts selected and their geometries (e.g., open baffle vs. full baffle) can be manipulated in a way that affects the dynamic discharge effect of each roll cylinder section 20 and the discharge difference between the sections. Additionally, the gap between the dosing ring 22 and the main shaft 26 can be varied to alter the dynamic discharge effect of each cylinder section 20 and the discharge difference between the cylinder sections 20.

[0141] The standard planetary shaft 30 is represented by a cylinder in which grooves or baffles are cut at an angle of 45° to the axis of the shaft, the same angle as the main shaft baffle. The planetary shaft straddles the main shaft baffle, and this exemplary design is shown in Figure 4 and Figure 9 In, the planetary shafts 28, 30 and the main shaft 26 produce the same surface speed. There is a gap between the main shaft and the planetary shafts, and this gap is filled with the processing material, and the end result is that near-zero shear distribution and dispersive mixing can occur between the main shaft 26, the planetary shafts 28, 30, and the cylinder wall 24. Other arrangements of shafts and baffles can be used. For example, shafts from Rust-Mitschke-Entex (Bochum, DE) can be used, including standard Noppen shafts, Igel shafts, Transport shafts, Kombi shafts.

[0142] Another end result of the 45° angle cut into the planetary and main shafts is the generation of a positive pressure, i.e., a forward movement exerted on the processing material. One variation that produces less pressure, more sliding, less forward movement, longer residence times, and thus greater mixing is to use a double transverse shaft 28 (also known as a noppen shaft or a back-cut shaft).

[0143] The double transverse planetary shaft 28 is a shaft with an opening in the baffle that allows material to pass between the wall of the cylinder 24 and the main shaft 26 and slows down the speed of the material through the low-shear extrusion equipment system 10. An example of a double transverse shaft 28 is the so-called perforated shaft. A specific example of the double transverse shaft 28 is shown in detail in Figure 5In this case, the post-cut openings 32 increase the residence time and improve mixing. The design of the double transverse shafts 28 is a variant of the standard planetary shafts, and these double transverse shafts increase the channels cut into the 45° angle baffles. The angles of these post-cut channels can be in the range of about 45° to 135° relative to the shaft baffles, more specifically in the range of about 75° to 105°, and according to certain aspects of the present disclosure, the post-cut channels can be at an angle of about 90°. The number and depth of these channels can also vary and can be defined in the following simpler terms: [(total channel area cut into the shaft baffle / total area of the shaft baffle) × 100%]. This value can be about 10% to 90%, more specifically about 40% to 60%, and in certain embodiments of the present disclosure, this value can be about 50%. The low-shear extrusion device with double transverse shafts 28 is commercially available from Rust-Mitschke-Entex. By adjusting the number of full baffles 30 and openings or double transverse shafts 28, the speed of the material passing through the low-shear extrusion device can be controlled, thereby controlling the amount of kneading of the material.

[0144] Conventional low-shear extrusion devices accommodate at least 3 shafts and can accommodate up to 24 shafts, depending on the diameter of the cylinder and the process design. Of course, those skilled in the art will recognize that a greater number of planetary shafts can be used depending on the specific size and configuration of the extruder. In one embodiment of the present disclosure, a low-shear extrusion device 10 with a 70 mm diameter cylinder is used, and this cylinder has 6 shafts 28, 30. According to certain aspects of the present disclosure, the double transverse shafts 28 account for more than 20%, more specifically more than 50%, of the number of planetary shafts 28, 30 in the low-shear extrusion device 10. Figure 8 A cross-section of a planetary extruder according to a specific embodiment of the present disclosure is shown, which includes four (4) double transverse planetary shafts 28 and two (2) full baffle shafts 30. In one example, 75% full baffle shafts and 25% post-cut or Noppenspindlen are used to process the starch compositions of the present disclosure.

[0145] Due to the interaction between the helical gears of the main shaft 26 and the helical gears of the planetary shafts 28, 30, the rotation of the main shaft 26 drives the planetary shafts 28, 30 to perform rotational motion.

[0146] The planetary shafts 28, 30 also mesh with the internal gears of the cylinder section 24. The helical gears of the main shaft 26, the planetary shafts 28, 30, and the cylinder section 24 convey the raw materials to be compounded in the direction of the discharge orifice 34.

[0147] As used herein, the term "secondary raw material" refers to the raw material or solvent introduced into the compounding section 14 of the low-shear extrusion device 10. Secondary liquid materials such as liquids, molten resins, oils, solvents, plasticizers, etc. can be introduced into the compounding section 14 through the dosing ring 22 assembly via an injection nozzle (not shown). AsFigure 6 As shown, the dosing ring 22 includes radially extending holes 23 that allow for metered addition of liquid into the compounding section 14. According to one embodiment of the present disclosure, the method involves feeding a solvent via the dosing ring 22 into the compounding section 14 of the low-shear extrusion device 10.

[0148] The secondary solid feedstock can be added to the compounding section 14 via the side feeder 36 or the twin-screw dosing unit 38. The twin-screw dosing unit 38 is typically positioned perpendicular to the axis of the compounding section 14 and is typically located near the start of the compounding section adjacent to the dosing ring 22a. The twin-screw dosing unit 38 can be used to introduce solid components such as reinforcing agents, thermoplastic elastomers, resins, extenders, activators, anti-degradants, crosslinking agents, etc. into the separate roll cylinder section 20.

[0149] Another embodiment of the present disclosure involves coating a starch film composition onto a paper backing using any one of a variety of coating techniques, including but not limited to slot die coating, roll-to-roll coating, calendering coating, reverse roll, and knife-over-roll coating. According to certain embodiments of the present disclosure, an adhesive composition is applied to the starch film and / or any intervening paper material using a slot die applicator unit. A particularly useful method of applying an adhesive composition to a web material includes slot die coating using a rotating lip die or a fixed lip contact die. One specific slot die unit that can be used is a rotating lip die having an axis that follows the die lip. An example of such a die is commercially available from SIMPLAS and is shown in Figure 7 . The rotating lip die 40 includes an inlet 42 for receiving the adhesive composition from the extruder 10. As Figure 8 shown, the starch composition can be continuously conveyed from the planetary extruder 10 to the rotating lip die 40 applicator for application through the slot 44 to the web material. The rotating lip die applicator 40 also includes a rotating shaft 46 at the trailing edge of the die lip, which improves the coating characteristics of the applied adhesive. The adjustable bolts 48 on the rotating lip die applicator 40 enable the operator to easily adjust the lip opening and control the adhesive coating thickness.

[0150] According to another aspect of the present disclosure, the starch-containing composition can be crosslinked. More specifically, the starch-containing composition can be thermally crosslinked, chemically crosslinked, for example, with azides, epichlorohydrin, formaldehyde, phosphoric acid, acrolein, sodium tetraborate, epoxides, acid anhydrides, and / or crosslinked by ionizing radiation (such as electron beam) by means of electron beam or UV rays, such that the resulting starch-containing composition provides a shear-resistant and temperature-stable film, web, scrim, or layer.

[0151] Additional advantages of certain embodiments of the new disclosure / methods include: 1) purposeful, effective, and efficient mixing, e.g., mixing a starch-containing composition with minimal shear; 2) introducing various additional materials into the compounding section; 3) introducing a solvent or water in one state into the compounding section; and 4) using granulation, slot die, or annular die coating techniques to obtain a web, film, or sheet material.

[0152] The compounding of the presently disclosed starches or modified starches with redispersible materials is accomplished as follows: When a single screw is used to force the starch from the feed section between the feed ring and the main shaft into the compounding section, the starch is mixed in the compounding section and then compounded. By selecting an appropriate combination of the planetary shaft geometry and the number of planetary shafts employed, the degree of shear and / or chain scission of the starch can be minimized. The reduction in shear of the starch or modified starch means more efficient compounding of the starch with the redispersible materials and other solid and liquid materials and has the potential to minimize the reduction in molecular weight.

[0153] Thus, in one example, starch, alone or in combination with redispersible materials and other solid and liquid materials, is compounded such that the average or number-average Mw is reduced to less than 5%, less than 10%, less than 20%, less than 30%, less than 24%, less than 50%, as measured by GPC. This reduction is relative to the initial molecular weight of the starch when it is introduced into the low-shear extrusion device. Thus, the initial molecular weight may already have been reduced due to preprocessing of the starch compared to the molecular weight of the unprocessed starch. Thus, the reduction in molecular weight referred to herein is based on the reduction in molecular weight obtained by processing on a low-shear extrusion device. The reduction in molecular weight as described herein is calculated by Equation I:

[0154] Percent reduction = (Mw(initial) - Mw(final)) / Mw(initial) × 100 (I)

[0155] Introducing various additional materials into the compounding section has several advantages. First, all such additional materials do not have to be introduced all at once into the feed section of the low-shear extrusion device, i.e., they can be metered in one or more roller cylinder sections of the compounding section. This allows more time for the starch to be compounded before adding the redispersible materials and other solid and liquid materials and improves the mixing efficiency of the low-shear extrusion device. The addition of the redispersible materials and other solid and liquid materials further improves the mixing efficiency, tends to act as a lubricant, and improves the mixing efficiency. Additionally, the redispersible materials and other solid and liquid materials can have a specific heat capacity that provides the ability to act as a heat sink, i.e., to remove heat from the process, thereby minimizing the temperature of the melt during the compounding process.

[0156] In a first process step, a composition comprising starch and redispersible materials, as well as other solid and liquid materials and known aids such as extenders, antioxidants, activators, colorants, anti-aging agents, plasticizers, and tackifying resins, is produced in a low-shear extrusion device. The composition has a final temperature of less than 200 °C, less than about 150 °C, 140 °C, 130 °C, 120 °C, 110 °C, for example, from about 25 °C to 175 °C. The total residence time of the composition in the low-shear extrusion device generally does not exceed about three minutes, five minutes, ten minutes, or longer.

[0157] In certain aspects of the present disclosure, the starch film exiting the extruder can be immediately used as a web material or can be granulated for film processing and later casting. This can be accomplished in a particularly effective and advantageous manner using a slot die applicator, especially a rotating lip slot die applicator unit.

[0158] In one example, the presently disclosed starch-based reinforcement or a tape comprising the starch-based reinforcement is at least 60% to about 99% redispersible. In one example, the presently disclosed starch-based reinforcement or a tape comprising the starch-based reinforcement is at least 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% or more redispersible. In one example, according to the 2013 voluntary standard for repulping and recycling corrugated fiberboard by the Fiber Box Association, which is intended to improve the performance of corrugated fiberboard in the presence of water and water vapor (″FBA method″), the presently disclosed starch-based reinforcement or a tape comprising the starch-based reinforcement is at least 60% to about 99% redispersible.

[0159] While certain embodiments of the present disclosure have been shown with reference to specific combinations of elements, various other combinations can also be provided without departing from the teachings of the present disclosure. Accordingly, the present disclosure should not be construed as limited to the specific exemplary embodiments described herein and shown in the figures, but can also encompass combinations of the elements of the various shown embodiments and aspects thereof.

Claims

1. A strip, the strip comprising: A reslurriable backing having a first major surface and an opposite second major surface; A reslurriable reinforcement adjacent to the second major surface; and An adhesive layer adjacent to the reslurriable reinforcement.

2. The strip according to claim 1, wherein the reslurriable backing substantially comprises cellulose, unmodified starch, modified starch, synthetic starch, crosslinked starch, thermoplastic starch, polyvinyl alcohol or polyvinyl alcohol copolymer and its salts, polyvinylimine, polyvinylpyrrolidone, polyalkylene oxide, polyhydroxyalkanoate, polyacrylamide, cellulose ether, cellulose ester, cellulose amide, polyvinyl acetate, polyamide, poly(meth)acrylic acid, poly(meth)acrylate and its salts, gelatin, methyl cellulose, carboxymethyl cellulose and its salts, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, dextrin, maltodextrin, guar gum, gum arabic, xanthan gum, carrageenan, their copolymers, their blends and their combinations.

3. The strip according to claim 2, wherein the reslurriable backing is paper, such as kraft paper.

4. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement is adjacent to the reslurriable backing. The strip according to any one of the preceding claims, wherein the reslurriable backing is extruded laminated or adhesively laminated to the reslurriable reinforcement, or the reslurriable backing is adhesively laminated to the reslurriable reinforcement without an adhesive.

5. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement is a film, a mesh or a scrim comprising unmodified starch, modified starch, synthetic starch, thermoplastic starch, crosslinked starch or a mixture of two or more thereof.

6. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement is at least 90% by weight soluble in hot water or reslurriable under pulping conditions.

7. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement comprises unmodified starch, modified starch, synthetic starch, thermoplastic starch or crosslinked starch derived from cassava, corn, potato, sweet potato, sago, tapioca starch, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, dent or pea.

8. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement comprises unmodified starch, modified starch, synthetic starch, synthetic starch, thermoplastic starch or crosslinked starch derived from glutinous rice, waxy potato starch and waxy corn.

9. The strip according to any one of the preceding claims, wherein the reslurriable reinforcement is an extruded mesh, film or layer.

10. The web according to any one of the preceding claims, wherein the redispersible reinforcing agent comprises a starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100, a modified starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100, a synthetic starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100, or a thermoplastic starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:

100.

11. The web according to any one of the preceding claims, wherein the redispersible reinforcing agent comprises a starch blend having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100, wherein the starch blend comprises unmodified starch, modified starch, synthetic starch, thermoplastic starch, or a combination thereof.

12. The web according to any one of the preceding claims, wherein the redispersible reinforcing agent comprises a starch blend comprising a combination of a first starch and a second starch, the first starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, the second starch having an amylose to amylopectin weight ratio of 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, synthetic, or crosslinked.

13. The web according to any one of the preceding claims, wherein the redispersible reinforcing agent comprises a combination of starch or modified starch with polyvinyl alcohol or a polyvinyl alcohol copolymer.

14. The web according to any one of the preceding claims, wherein the adhesive layer is a water-activated adhesive.

15. The web according to claim 14, wherein the water-activated adhesive is a polyvinyl acetate emulsion adhesive, a polyvinyl acetate ethylene adhesive, a poly(meth)acrylic acid or a poly(meth)acrylic acid emulsion adhesive, a starch-based adhesive, a redispersible pressure-sensitive adhesive, or a combination or laminate thereof.

16. The web according to any one of the preceding claims, wherein the web is at least 80 wt%, at least 85 wt%, or at least 90 wt% soluble in hot water or redispersible under pulping conditions.

17. A film, the film comprising: starch; and an amount of redispersible material.

18. The film according to claim 17, wherein the starch present in the film is an alkyl etherified starch, a carboxyalkyl etherified starch, a hydroxyalkyl etherified starch having a hydroxyalkyl group having 2 to 6 carbon atoms, a thermoplastic starch, a synthetic starch, or is derived from tapioca, corn, potato, sweet potato, sago, cassava starch, sorghum, kidney bean, bracken, lotus root, water chestnut, wheat, rice, oats, arrowroot, dent, or pea.

19. The film according to any one of claims 17 to 18, wherein the starch comprises a weight ratio of amylose to amylopectin of 40:60 to 0:100, and the starch includes a starch blend having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100; a modified starch having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100; a modified starch blend having a combined weight ratio of amylose to amylopectin of 40:60 to 0:100; a combination of a first starch and a second starch, the first starch having a weight ratio of amylose to amylopectin of 40:60 to 0:100, the second starch having a weight ratio of amylose to amylopectin of 40:60 to 0:100, wherein at least one of the first starch and the second starch is independently unmodified, modified, thermoplastic, synthetic or crosslinked.

20. The film according to any one of claims 17 to 19, wherein the repulpable material is polyvinyl alcohol or a polyvinyl alcohol copolymer and salts thereof, polyethyleneimine, polyvinylpyrrolidone, polyalkylene oxide, polyhydroxyalkanoate, polyacrylamide, cellulose ether, cellulose ester, cellulose amide, polyvinyl acetate, polyamide, gelatin, poly(meth)acrylic acid, poly(meth)acrylate and salts thereof, methylcellulose, carboxymethylcellulose and salts thereof, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, microfibrillated cellulose, modified microfibrillated cellulose, dextrin, maltodextrin, guar gum, gum arabic, gum arabic, xanthan gum, carrageenan, alginate, locust bean gum, gellan gum, copolymers thereof, blends thereof and combinations thereof.

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