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EP-4408170-B1 - ANTIMICROBIAL PACKAGING

EP4408170B1EP 4408170 B1EP4408170 B1EP 4408170B1EP-4408170-B1

Inventors

  • WILLIAMS, MARK

Dates

Publication Date
20260506
Application Date
20220923

Claims (14)

  1. A preservative and/or antimicrobial composition for inclusion in a substrate to form an active substrate and/or in a solvent-based coating for preservation of fruit, vegetables or herbs, comprising or consisting of the following combination of ingredients: calcium chloride (CaCl 2 ); sodium chloride (NaCl); citric acid; calcium hypochlorite (Ca(OCl) 2 ); nano-silver (Nano-Ag); and one or more dessicants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof, wherein the substrate comprises or consists of a substrate polymer selected from polyethylene including low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) or a blend thereof, polyethylene terephthalate (PET), polypropylene (PP), biaxially oriented polypropylene (BOPP), cellulose, bio-polymers, thermoplastic starch (TPS), polylactic acid (PLA), non-woven PP and non-woven PET; and wherein the solvent-based coating is formulated for coating one or both surfaces of a substrate comprising a single layer substrate or a multi-layer substrate, including a laminated multi-layer substrate, the substrate being selected from the group comprising or consisting of paper, polyethylene including low LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET, the active substrate, or a portion thereof and comprises or consists of the following ingredients: a solvent-based urethane composition with a greater part of a ester blend, including an elastomeric aliphatic solvent-based urethane; one or more solvents selected from the group comprising: a polar aprotic solvent, further including ethyl acetate; a polar protic solvent, further including ethanol; and one or more organic solvents further including one or more glycol ethers, including ethoxy propanol, n-propyl acetate and/or 1-propyl acetate or any combination of said solvents; a binder including nitrocellulose, further including a nitrocellulose RS grade 1/8 sec varnish; optionally a slip, scratch or rub resistance, gloss retention and overprintability additive, including a micronized spherical Fischer-Tropsch linear hydrocarbon chain hardwax, including a 50% Fischer-Tropsch liquid wax mixture; and optionally a viscosity modifier including bentonite clay organically modified with a quaternary alkylammonium compound.
  2. A solvent-based coating composition in which the preservative and/or antimicrobial composition according to claim 1 is included, comprising or consisting of a mixture of the following ingredients: (i) a combination of preservative and/or antimicrobial agents provided as percentage weight / weight (% (w/w)) of the combination of preservative and/or antimicrobial agents selected from the group comprising or consisting of: 0,003% to 0,08% (w/w), or 0,008 % to 0,05 % (w/w), or 0,01 % to 0,05 % (w/w), or 0,05 % to 0,08 % (w/w) nano-silver (nano-Ag), 1,0% to 6,5% (w/w), or 2,0 % to 5,0 % (w/w), or 3,0 % to 5,5 % (w/w), or 4,0 % to 6,5 % (w/w), calcium hypochlorite (Ca(OCl) 2 ), 0,5% to 6,5% (w/w), or 2,0 % to 5,0 % (w/w), or 3,0 % to 5,5 % (w/w), or 4,0 % to 6,5 % (w/w), sodium chloride (NaCl), 1,0% to 10,0% (w/w), or 2,0% to 6,0% (w/w), or 4,0 to 8,0% or 5,0 to 10,0% (w/w) citric acid, 0,05% to 0,65% (w/w), or 0,20 % to 0,50 % (w/w), or 0,30 % to 0,55 % (w/w), or 0,40 % to 0,65 % (w/w) calcium chloride (CaCl 2 ), and additional one or more dessicants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof to make up the remainder of the % (w/w) of the combination of preservative and/or antimicrobial agents; and (ii) a solvent-based coating composition provided as % (w/w) comprising or consisting of the following ingredients: (iii) Component % Amount (w/w) solvent-based urethane with a greater part of a ester blend 45 - 55% one or more solvents selected from the group comprising: a polar aprotic solvent, further including ethyl acetate; a polar protic solvent, further including ethanol; and one or more organic solvents further including one or more glycol ethers, including ethoxy propanol, n-propyl acetate and/or 1-propyl acetate or any combination of said solvents 25 - 35% slip, scratch or rub resistance, gloss retention and overprintability additive, including micronized spherical Fischer-Tropsch linear hydrocarbon chain hardwax including a 50% Fischer-Tropsch liquid wax mixture 1 - 5% a binder including nitrocellulose, further including a nitrocellulose RS grade 1/8 sec varnish 20 - 30% a viscosity modifier including bentonite clay organically modified with a quaternary alkylammonium compound 8 - 12% wherein the ratio of the preservative and/or antimicrobial agent combination to the solvent-based coating composition in the mixture is about 40:60 to 90:10, or about 50:50, or about 60:40, or about 70:30, or about 80:20 respectfully.
  3. An active substrate in which the preservative and/or antimicrobial composition according to claim 1 is included comprising or consisting of a mixture of the following ingredients: I. a combination of preservative and/or antimicrobial agents provided as % (w/w) selected from the group comprising or consisting of: 0,10 - 4,00 % (w/w), or 0,15 - 2,00 % (w/w), or 0,2 - 1,00 % (w/w) or 0.10 to 0.50 (w/w) nano-Ag, 0,05 - 4,00 % (w/w), or 0,15 - 2,50 % (w/w), or 1,50 - 3,50 % (w/w), or 2,00 - 4,00 % (w/w) Ca(OCl) 2 , 0,05 - 4,00 % (w/w), or 0,15 - 2,50 % (w/w), or 1,50 - 3,50 % (w/w), or 2,50 - 4,00 % (w/w) sodium chloride (NaCl), 0,1% - 8,0 % (w/w), or 3,0% - 7,5 % (w/w), or 4,0% - 7,5 % (w/w), or 5,0% - 8,0 % citric acid, 0,008 - 1,000% (w/w), or 0,020 - 0,100% (w/w), or 0,080 - 0,500% (w/w), or 0,300 to 1,000% (w/w) calcium chloride (CaCl 2 ), and one or more dessicants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof to make up the remainder of the % (w/w) of the combination of preservative and/or antimicrobial agents; and II. a substrate polymer selected from polyethylene including LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET, wherein the ratio of the combination of preservative and/or antimicrobial agents to the substrate polymer in the mixture is from 1,4 : 98,6 to 6,0 : 94,0, or from 2,5 : 97,5 to 5,0 : 95,0, or from 4,0 : 96,0 to 6,0 : 94,0.
  4. A substrate, including an active substrate according to claim 3 coated on one or both surfaces, or a portion thereof, with a monolayer or with a plurality of layers of the preservative and/or antimicrobial coating composition according to claim 2, wherein the substrate is selected from the group comprising or consisting of paper, polyethylene LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET.
  5. The substrate according to claim 4, further comprising one or more additional coating layer(s) selected from the group comprising one or more oxygen transmission rate (OTR) and/or moisture vapour transmission rate (MVTR) modifier(s), wherein the layer(s) of the preservative and/or antimicrobial coating composition are applied to the substrate surface(s) or a portion thereof prior to or subsequent to application of the one or more additional coating layer(s).
  6. The active substrate according to claim 3 or the coated substrate according to claim 4, that is processed to form one or more of a liner, cover, pad and/or bag for packaging of fruit, vegetables or herbs, including where the liner, cover, pad and/or bag comprises a plurality of perforated apertures.
  7. The preservative and/or antimicrobial composition according to claim 1, the preservative and/or antimicrobial coating composition according to claim 2, the active substrate according to claim 3, or the coated substrate according to any one of claims 4 to 6, wherein the preservation is to prevent browning and/or dessication, including of stems and/or fruit, and/or to prevent, inhibit, control, or delay growth of, or kill fungi, including Botrytis sp. fungi.
  8. A method of formulating the preservative and/or antimicrobial coating composition, comprising or consisting of the following steps: (a) adding about 30 to 40% (w/w) of the solvent-based coating composition and 100% (w/w) of the preservative and/or antimicrobial combination according to claim 1 to a stainless steel mixer bowl and whisking the mixture until a homogenous mixture is obtained; (b) adding the remaining about 60 to 70 % (w/w) of the solvent-based coating composition to the homogeneous mixture of step (a) and whisking the mixture further until a homogenous solvent-based preservative and/or antimicrobial coating composition mixture is obtained, wherein the ratio of the preservative and/or antimicrobial agent combination to the solvent-based coating composition in the final homogenous mixture is about 40:60 to 90:10, or about 50:50, or about 60:40, or about 70:30, or about 80:20 respectfully; and (c) decanting the homogenous composition mixture of step (b) into a container or a drum with continual stirring and/or circulation of the mixture including with the use of a centrifugal pump, thereby to prevent partial separation of the ingredients and for pumping the final solvent-based preservative and/or antimicrobial coating composition to a coating head of a coating system for coating of a substrate.
  9. A method of producing a substrate coated with the preservative and/or antimicrobial coating composition obtained with the method of claim 8, with the use of a coating system comprising one or more coating head(s) (10) fitted to a frame having offwinds and rewinds of a desired substrate, wherein each coating head (10) comprises: I. a reservoir tray (12) for holding a volume of the preservative and/or antimicrobial coating composition of the invention; II. an uplift roller (14) for uplifting the preservative and/or antimicrobial coating composition to a regulation roller (16); III. a regulation roller (16) for transferring the preservative and/or antimicrobial coating composition to an impression roller (18); IV. an impression roller (18) for impressing the preservative and/or antimicrobial coating composition transferred by the regulation roller (16) onto the desired surface of the substrate which is supported by web support roller (20); and V. a web support roller (20) for supporting the substrate when in contact with impression roller (18), and wherein the method comprises the following steps: A. decanting the mixed preservative and/or antimicrobial coating composition into a container or drum with continual stirring and/or circulation of the mixture including with the use of a centrifugal pump, in preparation for coating; B. fitting a regulation roller (16) having a desired surface roughness to the coating head; C. fitting an impression roller (18) having the desired width to the coating head; D. webbing the substrate between the impression roller (18) and a web support roller (20); E. pumping the preservative and/or antimicrobial coating composition from the container or drum into a reservoir tray (12); F. checking the viscosity of the preservative and/or antimicrobial coating composition to ensure that it is from about 90 seconds to 4 minutes; G. activating the coating head so that the preservative and/or antimicrobial coating composition is uplifted from the reservoir tray (12) by the uplift roller (14), is transferred to the regulation roller (16), and then transferred to the impression roller (18) which impresses the preservative and/or antimicrobial coating composition onto the desired surface of the substrate webbed between the impression roller (18) and the web support roller (20).
  10. The method according to claim 9, wherein where there is more than one coating head, the coating system comprises a drying tunnel fitted downstream of the each coating head for drying of the coating on the substrate between the coating heads.
  11. A process for the formulation of an active substrate according to claim 3, comprising or consisting of the following steps: (A) providing a first masterbatch mixed with a film-forming polymer, selected from the group comprising or consisting of polyethylene, including LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET at a ratio of from 1,4 : 98,6 to 6,0 : 94,0, or from 2,5 : 97,5 to 5,0 : 95,0, or from 4,0 : 96,0 to 6,0 : 94,0 respectively, wherein the first masterbatch consists of: i. 0,008 - 1,000% (w/w), or 0,020 - 0,100% (w/w), or 0,080 - 0,500% (w/w), or 0,300 to 1,000% (w/w) calcium chloride (CaCl 2 ); ii. 0,05 - 4,00 % (w/w), or 0,15 - 2,50 % (w/w), or 1,50 - 3,50 % (w/w), or 2,50 - 4,00 % (w/w) NaCl; iii. 0,1% - 8,0 % (w/w), or 3,0% - 7,5 % (w/w), or 4,0% - 7,5 % (w/w), or 5,0% - 8,0 % (w/w) citric acid; and iv. one or more additives including desiccants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof to make up the remainder % (w/w); and (B) providing a second masterbatch mixed with a film-forming polymer, selected from the group comprising or consisting of polyethylene, including LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET at a ratio of from 1,4 : 98,6 to 6,0 : 94,0, or from 2,5 : 97,5 to 5,0 : 95,0, or from 4,0 : 96,0 to 6,0 : 94,0 respectively, wherein the second masterbatch consists of: i. 0,05 - 4,00 % (w/w), or 0,15 - 2,50 % (w/w), or 1,50 - 3,50 % (w/w), or 2,00 - 4,00 % (w/w) Ca(OCl) 2 ; and ii. one or more additives including including desiccants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof to make up the remainder % (w/w); and (C) providing a third masterbatch mixed with a film-forming polymer, selected from the group comprising or consisting of polyethylene, including LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET at a ratio of from 1,4 : 98,6 to 6,0 : 94,0, or from 2,5 : 97,5 to 5,0 : 95,0, or from 4,0 : 96,0 to 6,0 : 94,0 respectively, wherein the third masterbatch consists of: i. 0,10 - 4,00 % (w/w), or 0,15 - 2,00 % (w/w), or 0,2 - 1,00 % (w/w) or 0.10 to 0.50 (w/w) nano-Ag; and ii. one or more additives including including desiccants, carriers, including polyethylenes and process aids, including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof to make up the remainder % (w/w); and (D) adding the mixture of step (A) into the mixture of step (B), followed by adding the mixture of step (C) to the mixture of steps (A) and (B) with continual stirring and/or circulation of the mixture including with the use of a centrifugal pump; and (E) extruding the active substrate of step (D) into a sheet or film with an extruder, including a single screw blown film extruder.
  12. The method according to claim 11, wherein the film-forming polymer is formed from a blend of LDPE and LLDPE or TPS.
  13. A method of preserving products selected from fruit, vegetables or herbs and/or preventing, inhibiting, controling, or delaying growth of, or killing fungi, including Botrytis sp. on, in, or associated with said products comprising the use of the preservative and/or antimicrobial composition according to claim 1, the preservative and/or antimicrobial coating composition according to claim 2, the active substrate according to claim 3, or the coated substrate according to any one of claims 4 to 6.
  14. The preservative and/or antimicrobial composition according to claim 1, the preservative and/or antimicrobial coating composition according to claim 2, the active substrate according to claim 3, the coated substrate according to any one of claims 4 to 6, or the method according to claim 13, wherein the fruits are berries, including blueberries, blackberries, raspberries, strawberries.

Description

FIELD OF THE INVENTION This invention relates to a preservative and/or antimicrobial composition for inclusion in an active substrate and/or a solvent-based coating for preservation of fruit, vegetables or herbs as well as an active substrate including the preservative and/or antimicrobial composition, or a solvent-based coating composition including the preservative and/or antimicrobial composition, or an active substrate including the preservative and/or antimicrobial composition and coated with the solvent-based coating composition including the preservative and/or antimicrobial composition for use in the preservation of fruit, vegetables or herbs. BACKGROUND OF THE INVENTION Today, consumers expect to be able to purchase a wide range of fresh produce or botanicals, including fruit and vegetables, flowers and herbs throughout the year and regardless of whether the product is produced locally or must be imported. It is important to be able to maintain a shelf-life of at least a few days in order for such products to be commercially viable. There are a number of commercial packaging products for fresh fruit and vegetables as well as flowers which preserve the products and prevent microbiological growth and spoilage of these fresh products. Most commonly, these include the use of a sulphur dioxide or chlorine generating compound activated under conditions of humidity. Use of sulfur dioxide generating compounds are less desirable now, due to country and product-specific limitations on the allowable sulfur dioxide content. In addition, depending on the concentration of sulfur dioxide released, this can result in sulfur dioxide damage to the fresh produce, such as bleaching and burning, in particular with regard to sentitive produce such as berries. One way that sulfur dioxide generating compounds have been used in packaging materials to address these issues are to use multi-layer laminate products or pads that comprise the sulfur dioxide generating compounds within a matrix in the packaging, thereby to prevent direct contact of the sulfur dioxide generating compounds with the packaged fresh produce and to manage the concentration of sulfur dioxide generated by the sulfur dioxide generating compounds over time within the packaging material. However, these multi-layer materials are complex and expensive to produce, requiring multi-step fabrication and processing. It would be useful if a simpler and less harsh preservative and/or antimicrobial product for packaging fresh produce including fruit, vegetables and/or herbs was available which was still able to provide a preservative and/or antimicrobial effect. For example, WO 2015/130992 describes food packaging and commercial materials and processes that incorporate the release of chlorine dioxide gas to extend freshness and preserve integrity and shelf-life of packaged food. A further disadvantage of the commercial products used presently for preservation of fresh produce is that these are presently typically made from polymers that are not easily recyclable or potentially even biodegradable or compostable. It would therefore be highly beneficial to develop an environmentally friendly preservative and/or antimicrobial product that is recyclable and possibly may even be biodegradable or compostable. It would be further useful if such a product could be simple and cost effective to produce. SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a preservative and/or antimicrobial composition for inclusion in a substrate to form an active substrate and/or in a solvent-based coating for preservation of fruit, vegetables or herbs, comprising or consisting of the following combination of ingredients: calcium chloride (CaCl2);sodium chloride (NaCl);citric acid;calcium hypochlorite (Ca(OCl)2);nano-silver (Nano-Ag); andone or more dessicants, carriers, including polyethylenes and process aids,including one or more zeolites, silica, stearates, including calcium stearate or a combination thereof, wherein the substrate comprises or consists of a substrate polymer selected from polyethylene including low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) or a blend thereof, polyethylene terephthalate (PET), polypropylene (PP), biaxially oriented polypropylene (BOPP), cellulose, bio-polymers, thermoplastic starch (TPS), polylactic acid (PLA), non-woven PP and non-woven PET; andwherein the solvent-based coating is formulated for coating one or both surfaces of a substrate comprising a single layer substrate or a multi-layer substrate, including a laminated multi-layer substrate, the substrate being selected from the group comprising or consisting of paper, polyethylene including low LDPE or LLDPE or a blend thereof, PET, PP, BOPP, cellulose, bio-polymers, TPS, PLA, non-woven PP and non-woven PET, the active substrate, or a portion thereof and comprises or consists of the following ingredients: a solvent-based urethane compos