WO2007010553B1

WO2007010553B1 - Combined multi-layered water soluble film and process for producing the same

Info

Publication number: WO2007010553B1
Application number: PCT/IN2006/000105
Authority: WO
Inventors: Shilpan Pravinchandra Patel
Original assignee: Arrow Coated Products Ltd; Shilpan Pravinchandra Patel
Priority date: 2005-03-24
Filing date: 2006-03-24
Publication date: 2007-07-19
Also published as: EP1863635A2; ZA200709177B; WO2007010553A2; WO2007010553A3

Abstract

This invention relates to a combined water soluble film wherein at least one layer is a solution cast water soluble film on a liner and at least one layer is a preformed water soluble film, preferably a thermally extruded water soluble film. The said water soluble films may be edible or non edible. The said water-soluble film on a liner is coated with a tie-coat to enable coating of a water-based binder used for combining the water soluble films without dissolving/damaging WSF on liner. The water based binder used for combining the said water soluble films may be incorporated with active ingredients like flavours, perfumes, detergents, enzymes, softeners, active agents for cleaning laundry, dishes, floorings, walls, furniture; various agrochemicals like pesticides, insecticides, weedicides, fungicides, bio-pesticides; agro nutrients like urea, fertilizers; dyes, pigments, fluff, pulp, super absorbents and active pharma ingredients like vitamins, drugs, medicine. The said combined water soluble film so achieved will be a substantially pinhole free multi-layered water soluble film of desired mechanical strength at low cost. The invention farther relates to the methods/processes used for producing a cast-extruded or cast-cast combined WSF.

Claims

AMENDED CLAIMS received by the International Bureau on 23 May 2007 (23.05.07).

1. A multilayer combined water soluble film containing no barrier coat, comprising at least first solution cast water soluble film ("water soluble film abbreviated as "WSF") provided with a detachable liner combined with one or more of a WSF and further provided with a binder coat in between the two WSF layers; wherein the said binder coat comprises a batch solution of WSF and the like, and the said binder coat is preferably associated with a water repellent coating including acrylic dispersions used as a tie coat between a WSF and the binder coat.

2. A multilayer film according to claim 1 comprising one or more of an active ingredient incorporated in the binder coat and/or in the said water repellent coating used as a tie coat and/or within one or more of a layer of the said multilayer film.

3. A multilayer film as claimed in claim 2, wherein the active ingredient is selected from one or more of a flavour, a perfume, a detergent, an enzyme, a softener, an active agent for cleaning laundry, a dish, a flooring, a wall, a furniture; one or more of an agrochemical including one or more of a pesticide, an insecticide, a weedicide, a fungicide, a bio-pesticide; an agro nutrient including urea, a fertilizer; a dye, a pigment, a fluff, a pulp, a super absorbent, an active pharma ingredient including a vitamin, a drug, a medicine and the like.

4. A process of producing a multilayer combined WSF according to claim 1 comprising of the following steps: a. providing a first WSF with detachable liner forming one layer of the multi-layer WSF; b. providing a second preformed WSF with or without a detachable liner forming another layer of the multi-layer WSF; c. applying a water repellent coating as a tie-coat on one side of the WSF with the liner; d. drying and curing the WSF coated with tie coat; e. applying a binder coat over the said tie coat of the WSF with liner; f. semi-drying the binder coat of the first WSF with liner; g. passing the second preformed WSF with the first preformed WSF from step (f) through a nip roll of the coating machine to form a laminated double layered WSF; h. passing the double layered combined WSF through heated rolls for dissipating the entrapped moisture; i. storing the double layered WSF from step (h) for internal ageing; and j. detaching the liner and slitting/cutting the double layered WSF as per requirement.

5. A process for producing a multilayer combined WSF according to the claim 1 comprising of the following steps: a. providing a first WSF, preferably a preformed WSF, with detachable liner forming one layer of the multi-layer WSF; b. providing a second preformed WSF with or without a detachable liner forming another layer of the multi-layer WSF; c. applying a binder coat over the side of the first WSF opposite to liner; d. moving / running the WSF with liner at a speed enough for semi-drying the binder before the applied binder can dissolve the WSF on which it is applied; the said speed preferably be around a range from 15 to 100 meter/min., more preferably from 25 to 70 meter/min; e. passing the second preformed WSF with the first preformed WSF from step (d) through a nip roll of the coating machine to form a laminated double layered WSF; f. passing the double layered combined WSF through heated rolls for dissipating the entrapped moisture; g. storing the double layered WSF from step (f) for internal ageing, and h. detaching the liner and slitting/cutting the double layered WSF as per requirement..

6. A process of producing a multilayer combined WSF according to claim 1 wherein the first WSF is formed in situ by: a. providing a liner and casting the first WSF on it using WSF in a batch reactor and metering the cast WSF at a primary casting head, the temperature of the batch solution in the reactor ranging from 10⁰C to 95⁰C, preferably from 13⁰C to 90⁰C and more preferably from 15⁰C to 85⁰C₃ b. drying the cast WSF of step (a) to form said first WSF with liner, the temperature in the drying section ranging form 50⁰C to 200⁰C, preferably from 60⁰C to 175⁰C and more preferably from 75⁰C to 150⁰C.

7. A method/process of producing a multilayer combined WSF of claim 1 comprising of the following steps: a. extruding a desired thickness of WSF directly onto a preformed cast WSF with liner through an extruder; b. passing the combined WSF laminate of step (a) through chilling cylinders, keeping the said liner in contact with the chilling cylinder; c. storing the combined WSF for an internal ageing period; and d. detaching the liner and slitting/cutting the combined WSF laminate as per requirement.

8. A process according to any one of claim no. 4 or 6, further including the step of providing the said double layered combined WSF with detachable liner with a hydrophobic coat as a tie coat and then a binder coat and combined with a third layer of WSF by passing through a nip roll to form a three layered combined WSF.

9. A process according to any one of claim nos. 4 to 7, wherein a desired thickness of WSF is directly extruded on the said double layered combined WSF with detachable liner to form a three layered combined WSF.

10. A process according any one of a claim no. 4 to 9, wherein any one or more of a process is repeated in any sequence to add one or more of a WSF to form a multilayered combined WSF.

11. A combined WSF according to any one of the claim no. 1 to 10 wherein a. the said solution cast WSF is formed of one or more of an edible material preferably selected from one or more of: i. a polyethyleneglycol, a polyvinylpyrrolidone, a proteinaceous binder including gelatin, a modified gelatin including phthaloyl gelatin, a polysaccharide including starch and one or more of its derivative, sorbitol, one or more of a sucrose derivative, gum Arabic, pullulan, dextrin and one or more of a water-soluble cellulose derivative or a combination thereof, the cellulose derivatives used including methyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose, hydroxy propyl ethyl cellulose, hydroxy ethyl cellulose and carboxy methyl cellulose and the like, or ii. one or more of a non-edible material preferably selected from a Polyvinyl alcohol copolymer ionomer, a Polyvinyl alcohol homopolymer, a non - ionomeric poly vinyl alcohol polymer, a Polymethacrylate., a polyvinyl alcohol, a polyacrylamide, a polymethacrylamide, a polyacrylic acid, a polymethacrylic acid, a biodegradable polyesters such as ecoflex; a polylactic acid (PLA), a polyhydroxyalkanoic acid (PHA), a polyurethane and the like, b. the said detachable liner of the said solution cast WSF and, where provided with the said preformed WSF, is made of paper, film, foil or fabric, treated or untreated, coated or uncoated; preferably made of a a polyester film, wherein the preferred thickness of the film ranges from 3 microns to 500 microns, preferably from 10 microns to 300 microns, more preferably from 25 microns to 100 microns and preferably is plain, metallised, embossed, gloss, matt, extrusion coated, laminated or release coated, c. the said water repellent coating used as a tie coat being preferably selected from one or more of an acrylic acid polymer, an acrylic ester polymer, a soluble acrylic acid copolymer, a soluble acrylic ester copolymer, a soluble copolymer of acrylic acid and ester, a cross linked polyvinyl alcohol, a cross linked cellulose derivative, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl polyalcohol, ethylene vinyl acetate, PVDC (polyvinyldene chloride), acrylic emulsion, PVC (polyvinyl chloride) emulsion, PVDC emulsion, PVB (polyvinyl butyral), a natural wax, a synthetic wax, a polyurethane, a modified polyvinyl alcohol and the like, d. the said binder coat is preferably selected from an adhesive comprising one or more of a pressure sensitive adhesive, a cast water soluble film solution, a polyurethane dispersion, a liquid flavour, and the like.

12. A process according to claim no. 4 or 8 or 10, wherein: a. the said tie-coat is applied by using a gravure cylinder of varying cell sizes and depths; or by using flexo plates of varying cell sizes and depths, or by combination of flexo plates with gravure cylinder, for transferring net solid contents of the tie-coat from the cells of the cylinder, b. the tie coat is dried at a temperature ranging from 5O⁰C to 200⁰C, preferably from 6O⁰C to 175⁰C, more preferably from 75⁰C to 15O⁰C, c. the said binder coat is applied by using a wire bound mayer bar, d. the said binder has a viscosity ranging between 10 and 75 seconds, preferably between 15 and 55 seconds, more preferably between 17 and 50 seconds, and solid content ranging between 30% and 90%, preferably between -40% and 70%, more preferably between 50% and 60%.

13. A process according to any of claims 4 to 10, wherein the raw materials of the WSF, the binder and/or where provided tie-coat are selected such that the combined WSF is soluble in cold water, or warm water or hot water.; wherein said cold water soluble film does not dissolve at a temperature below 5⁰C, the said warm water soluble film does not dissolve at a temperature below 40⁰C, and the said hot water soluble film does not dissolve at a temperature below 60⁰C.

14. A process according to claim 7 or 9, wherein the said liner is a hydrophobic, thermally active detachable liner.

15. A process according to any one of claim no. 4 to 10 wherein the said combined WSF laminate is stored for an internal ageing period ranging from 1 hour to 720 hours, preferably from 10 hours to 360 hours and more preferably from 24 hours to 100 hours.

16. A method/process according to any of claims 4 to 10, wherein one or more of the same or different types of active ingredients are incorporated in the binder and/or where provided the tie-coat and/or in the extruder while extruding the desired thickness of WSF directly on the preformed WSF with liner.