Cellulose film with both barrier and heat-sealing properties, its manufacturing method and use

Abstract

The present invention provides a cellulose film having both barrier properties and heat sealability, a production method thereof and its use, and relates to the technical field of functional cellulose films. [Solution] The cellulose film having both barrier properties and heat sealability provided by the present invention comprises a barrier layer, a regenerated cellulose base film and an adhesive layer, which are laminated in this order, the barrier layer being formed of a barrier paint (polyvinylidene chloride emulsion, a first adhesion inhibitor and water), and the adhesive layer being formed of an adhesive paint (emulsion (acrylate emulsion and / or polyurethane emulsion), a second adhesion inhibitor and water). The cellulose film having both barrier properties and heat sealability provided by the present invention has high adhesive force and barrier properties, can be directly heat-pressed to paper products, has high adhesive strength with paper products, and meets the adhesive strength requirements for laminated paper. The cellulose film having both barrier properties and heat sealability provided by the present invention has high moisture barrier properties, high oxygen barrier properties, and excellent aroma retention, freshness retention and moisture resistance. The cellulose film having both barrier properties and heat sealability provided by the present invention has high heat seal strength by itself, can be heat-pressed to itself to produce a packaging bag, and the packaging bag has high seal strength.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on June 8, 2022, bearing application number CN202210642715.1 and entitled "Cellulose film with barrier and heat-seal properties, its manufacturing method and use," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of functional cellulose films, specifically to cellulose films having both barrier and heat-sealing properties, and to a method for producing and using the same. [Background technology]

[0003] Regenerated cellulose film, which is made from natural cellulose as a raw material, is biodegradable and environmentally friendly, making it an ideal environmentally friendly material.

[0004] Using regenerated cellulose film as a base film, solvent-based paints can be applied by dip coating or blade coating to produce cellulose film with heat-sealing and barrier properties, which can meet the application requirements of no-load, heat-sealing strength of 350g / 37mm or less.

[0005] With the constant ban on plastics being issued around the world, regenerated cellulose functional films used in various fields have become a hot spot in the demand for the packaging industry. However, due to the original heat sealing strength, they cannot meet the needs of the production of load-bearing packaging bags, and they are limited in many applications, such as uses similar to high adhesive strength, such as being unable to replace laminated hot melt plastic films to complete paper-film composite packaging products. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of this, an object of the present invention is to provide a cellulose film having both barrier properties and heat-sealing properties, as well as a method for producing and using the same. The cellulose film having both barrier properties and heat-sealing properties provided by the present invention has high adhesive strength between the film and paper, as well as high adhesive strength of the cellulose film itself, so that it meets usage requirements, and the application of an aqueous emulsion coating makes the production process environmentally friendly. [Means for solving the problem]

[0007] In order to achieve the above object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a cellulose film having both barrier properties and heat-sealing properties, which comprises a barrier layer, a regenerated cellulose base film, and an adhesive layer laminated in this order, the barrier layer is formed of a barrier coating containing a polyvinylidene chloride emulsion, a first anti-adhesion agent, and water; The adhesive layer is formed of an adhesive coating containing an emulsion, a second anti-adhesion agent, and water, and the emulsion contains an acrylate emulsion and / or a polyurethane emulsion.

[0009] Preferably, the mass ratio of the regenerated cellulose base film, the barrier layer and the adhesive layer is 77-87:4-8:9-15.

[0010] Preferably, the moisture content of the cellulose film having both barrier properties and heat sealability is 5 to 6%.

[0011] Preferably, the mass ratio of the polyvinylidene chloride emulsion to the first anti-adhesion agent in the barrier coating material is 100:1-3.

[0012] Preferably, the mass ratio of the acrylate emulsion to the second anti-adhesion agent in the adhesive coating is 100:0.5-1.5.

[0013] Preferably, the basis weight of the regenerated cellulose base film is 30 to 60 g / m 2 is.

[0014] The present invention provides a method for producing a cellulose film having both barrier and heat-sealing properties as described in the above technical solution, which includes the steps of simultaneously coating both sides of a regenerated cellulose base film with a barrier coating material and an adhesive coating material to form a barrier layer and an adhesive layer, respectively, to obtain a cellulose film having both barrier and heat-sealing properties.

[0015] Preferably, the simultaneous double-sided coating comprises pumping the barrier coating and adhesive coating into a first coating tank and a second coating tank, respectively, using a pneumatic diaphragm pump, and simultaneously coating the regenerated cellulose-based film on both sides using an anilox roll coating.

[0016] Preferably, the running speed of the anilox roll coating is 70 to 95 m / min, The mesh number of the anilox roll for applying the barrier coating is 100 to 250 mesh, and the coating amount of the barrier coating in a dry state is 3 to 5 g / m 2 and The mesh number of the anilox roll for applying the adhesive coating is 100 to 180 mesh, and the amount of the adhesive coating applied in a dry state is 4 to 7 g / m 2 is.

[0017] The present invention provides the use in the packaging field of a cellulose film having both barrier and heat-sealing properties as described in the above technical solution or a cellulose film having both barrier and heat-sealing properties obtained by the manufacturing method as described in the above technical solution.

[0018] The present invention provides a cellulose film with both barrier and heat-sealing properties, which includes a barrier layer, a regenerated cellulose base film, and an adhesive layer laminated in sequence. The barrier layer is formed of a barrier coating containing a polyvinylidene chloride emulsion, a first anti-adhesion agent, and water. The adhesive layer is formed of an adhesive coating containing an emulsion, a second anti-adhesion agent, and water. The emulsion contains an acrylate emulsion and / or a polyurethane emulsion. The cellulose film with both barrier and heat-sealing properties simultaneously possesses high adhesive strength and barrier properties, can be directly heat-pressed to paper products, has high adhesive strength with paper products, and mechanical strength, meets the adhesive strength requirements of laminated paper to some extent, and has high moisture and oxygen barrier properties, as well as excellent aroma retention, freshness retention, and moisture resistance. The cellulose film with both barrier and heat-sealing properties provided by the present invention has high self-adhesion and can be heat-pressed to form packaging bags, resulting in high sealing strength of the packaging bags, making it suitable for use as a packaging material. As shown in the test results of the examples, the cellulose film provided by the present invention, which has both barrier properties and heat sealability, has a basis weight of 40 to 60 g / m 2 , longitudinal tensile strength > 36N / 15mm, longitudinal elongation > 18%, adhesive strength between adhesive layer and paper product > 6N / 15mm, adhesive strength of adhesive layer itself > 7N / 15mm, oxygen permeability ≦ 5mL / (m 2 24h), water vapor permeability ≦12g / (m 2 ·24h), the surface tension of the barrier layer is ≥ 42 dynes, and the moisture content is ≤ 5.5 wt%.

[0019] The present invention provides a method for producing a cellulose film having both barrier properties and heat-sealing properties as described in the above technical solutions, which is simple in operation, has a wide supply source of raw materials, is low in cost, and is suitable for industrial production. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention provides a cellulose film having both barrier and heat-sealing properties, which comprises a barrier layer, a regenerated cellulose base film, and an adhesive layer laminated in that order.

[0021] In the present invention, the barrier layer is formed of a barrier coating material containing a polyvinylidene chloride emulsion, a first anti-adhesion agent, and water. In a specific embodiment of the present invention, the polyvinylidene chloride (PVDC) emulsion is preferably purchased from Solvay Chemical Industries, Inc., USA. In the present invention, the solids content of the polyvinylidene chloride emulsion is preferably 30 to 45%, more preferably 35 to 40%. In the present invention, the first anti-adhesion agent preferably contains one or both of a wax anti-adhesion agent and a silica powder anti-adhesion agent, the wax anti-adhesion agent being preferably Poligen WE-1 (BASF wax emulsion), and the particle size of the first anti-adhesion agent is preferably 100 to 300 nm, more preferably 150 to 200 nm. In the present invention, the water preferably contains soft water. In the present invention, the mass ratio of the polyvinylidene chloride emulsion to the first anti-adhesion agent in the barrier coating material is preferably 100:1-3, more preferably 100:1.5-2.5, and even more preferably 100:2.

[0022] In the present invention, the method for producing the barrier coating preferably includes a step of mixing a polyvinylidene chloride emulsion, a first anti-adhesion agent, and water to obtain a barrier coating. In the present invention, the mixing order is preferably to pre-mix the first anti-adhesion agent and water, and then mix the obtained first anti-adhesion agent liquid with the PVDC emulsion, the pre-mixing temperature is preferably room temperature, the pre-mixing speed is preferably 500 to 1000 r / min, more preferably 700 to 800 r / min, and the pre-mixing time is preferably 5 to 15 min, more preferably 10 min. The first anti-adhesion agent solution obtained is mixed with the PVDC emulsion. The speed is preferably 60 to 120 r / min, more preferably 80 to 100 r / min, The first anti-adhesion agent solution obtained is mixed with the PVDC emulsion. The time is preferably 15 to 25 minutes, more preferably 20 minutes. The first anti-adhesion agent solution obtained is mixed with the PVDC emulsion. The temperature is preferably room temperature. In the present invention, the thickness of the barrier layer is preferably 2 to 7 μm, more preferably 3 to 6 μm, and even more preferably 4 to 5 μm.

[0023] In the present invention, the adhesive layer is formed from an adhesive coating containing an emulsion, a second anti-adhesion agent, and water, and the emulsion contains an acrylate emulsion and / or a polyurethane emulsion. In the present invention, the selectable types and particle sizes of the second anti-adhesion agent are preferably the same as those of the first anti-adhesion agent, and detailed descriptions thereof will not be repeated here. In a specific embodiment of the present invention, the acrylate emulsion is preferably a DSM aqueous acrylic emulsion. In the present invention, the solids content of the acrylate emulsion is preferably 30 to 45%, more preferably 35 to 40%. In the present invention, the water preferably contains soft water. In the present invention, the mass ratio of the acrylate emulsion to the second anti-adhesion agent in the adhesive coating is preferably 100:0.5 to 1.5, more preferably 100:0.8 to 1.2, and even more preferably 100:1. In the present invention, the manufacturing method of the adhesive coating preferably includes a step of mixing an acrylate emulsion, a second anti-adhesion agent, and water to obtain an adhesive coating. In the present invention, the mixing order is preferably to pre-mix the second anti-adhesion agent and water, and then mix the obtained second anti-adhesion agent liquid with the acrylate emulsion, the pre-mixing temperature is preferably room temperature, the pre-mixing speed is preferably 500 to 1000 r / min, more preferably 700 to 800 r / min, and the pre-mixing time is preferably 5 to 15 min, more preferably 10 min. The resulting second anti-adhesion agent liquid is mixed with the acrylate emulsion. The speed is preferably 60 to 120 r / min, more preferably 80 to 100 r / min, The resulting second anti-adhesion agent liquid is mixed with the acrylate emulsion. The time is preferably 15 to 25 minutes, more preferably 20 minutes. The resulting second anti-adhesion agent liquid is mixed with the acrylate emulsion. The temperature is preferably room temperature. In the present invention, the thickness of the adhesive layer is preferably 4 to 7 μm, more preferably 4.5 to 6.5 μm, and even more preferably 5 to 6 μm.

[0024] In the present invention, the basis weight of the regenerated cellulose base film is preferably 30 to 60 g / m 2, more preferably 35 to 55 g / m 2 , more preferably 40 to 50 g / m 2 The thickness of the regenerated cellulose base film is preferably 20 to 40 μm, and more preferably 27 to 35 μm.

[0025] In the present invention, the mass ratio of the regenerated cellulose base film, barrier layer, and adhesive layer in the cellulose base film is preferably 77 to 87:4 to 8:9 to 15, more preferably 80 to 85:5 to 7:10 to 14, and even more preferably 82 to 83:6 to 6.5:12 to 13. In the present invention, the moisture content of the cellulose film having both barrier and heat-sealing properties is preferably 5 to 6%, more preferably 5.2 to 5.8%, and even more preferably 5.4 to 5.5%.

[0026] The present invention provides a method for producing a cellulose film having both barrier and heat-sealing properties as described in the above technical solution, which includes the steps of simultaneously coating both sides of a regenerated cellulose base film with a barrier coating material and an adhesive coating material to form a barrier layer and an adhesive layer, respectively, to obtain a cellulose film having both barrier and heat-sealing properties.

[0027] In the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

[0028] In the present invention, the method for producing the regenerated cellulose-based film is not particularly limited, and may be any method well known to those skilled in the art, specifically, the carbon disulfide viscose method, the method for producing regenerated cellulose film disclosed in the literature (Jia Xiangjuan, Research on the Production of Highly Adsorbent Regenerated Cellulose Materials by NMMO / H2O Solution Method [D], Shaanxi University of Science and Technology), or the method for producing regenerated cellulose film by directly dissolving cellulose in ionic liquid, which has already been realized on an industrial scale and was jointly developed by the Chinese Academy of Sciences and Shandong Henglian New Materials Co., Ltd.

[0029] In a specific embodiment of the present invention, the regenerated cellulose-based film is preferably produced by a carbon disulfide viscose process. Specifically, the cellulose raw material is alkalized and then yellowed to obtain cellulose xanthate, i.e., a viscose stock solution. The viscose stock solution is spray-formed into a film, and then placed in an acid coagulation regeneration bath for acid coagulation regeneration to obtain a regenerated cellulose film. In this embodiment, the fiber raw material preferably includes cotton pulp, softwood pulp, or hardwood pulp. In this embodiment, the alkalinizing solution preferably includes a sodium hydroxide solution. The alkalinizing solution has a concentration of preferably 17.5 to 18.5 wt%, more preferably 18 wt%, the alkalinizing temperature is preferably 45 to 65°C, more preferably 50 to 60°C, and the alkalinizing time is preferably 10 to 30 minutes, more preferably 15 to 25 minutes. During the alkalinizing process, cellulose and sodium hydroxide react to produce alkali cellulose. In the present invention, the yellowing agent is preferably CS2, the mass ratio of the alkali cellulose to the yellowing agent is preferably 1:0.25-0.32 (based on the amount used at 20°C), more preferably 1:0.3, the initial temperature of the yellowing is preferably 20-30°C, more preferably 25°C, and the yellowing time is preferably 30-60 min, more preferably 40-50 min. In the present invention, the acid coagulation regeneration bath preferably contains dilute sulfuric acid or a mixed solution of dilute sulfuric acid and sodium sulfate, the concentration of the dilute sulfuric acid is preferably 10-18 wt%, more preferably 12-15 wt%, and in the mixed solution of dilute sulfuric acid and sodium sulfate, the concentration of the dilute sulfuric acid (i.e., H2SO4 / H2O) is preferably 10-18 wt%, more preferably 12-15 wt%, and the concentration of the sodium sulfate is preferably 230-260 g / L, more preferably 245-255 g / L. In the present invention, it is preferable to carry out acid coagulation and regeneration by passing the fiber viscose stock solution through a casting die and introducing it into an acid coagulation and regeneration bath.

[0030] In the present invention, after obtaining a regenerated cellulose film, the regenerated cellulose film is subjected to a pretreatment and a softening and adhesion preventing treatment in that order to obtain a regenerated cellulose base film.

[0031] In the present invention, the pretreatment preferably includes sequentially subjecting the regenerated cellulose film to a first water wash, desulfurization, a second water wash, bleaching, desalting, and a third water wash. In the present invention, the first water wash, the second water wash, and the third water wash are each preferably performed 1 to 6 times, more preferably 2 to 4 times. In the present invention, the desulfurization is preferably performed using an alkaline solution, the concentration of which is preferably 1.5 to 3.5 g / L, more preferably 2 to 3 g / L, and the alkaline solution preferably contains an aqueous sodium hydroxide solution. In the present invention, the bleaching agent preferably contains sodium hypochlorite, hydrogen peroxide, or ozone, more preferably sodium hypochlorite, the concentration of which is preferably 1 to 4 g / L, more preferably 1.5 to 2.5 g / L. In the present invention, the dechlorination preferably includes washing with soft water.

[0032] In the present invention, the softener-anti-adhesion agent aqueous dispersion used in the softening and anti-adhesion treatment contains a softener, an anti-adhesion agent, and water. The softener preferably contains a polyol, more preferably triethylene glycol or glycerin. The anti-adhesion agent preferably contains nanosilica. The particle size of the anti-adhesion agent is preferably 5 to 600 nm, more preferably 80 to 100 nm. In the present invention, the mass ratio of the softener to the anti-adhesion agent is preferably 30 to 50:1.5 to 5, more preferably 35 to 45:2 to 4.5, and even more preferably 40 to 45:3 to 4. In the present invention, the water is preferably softened water. In the present invention, the concentration of the softener in the softener-anti-adhesion agent aqueous dispersion is preferably 30 to 50 g / L, more preferably 35 to 45 g / L, and even more preferably 40 to 45 g / L. In the present invention, the amount of the softener-anti-adhesion agent aqueous dispersion used is not particularly limited as long as it is an amount that allows the wet regenerated cellulose film to be immersed in. In the present invention, the temperature of the softening and anti-adhesion treatment is preferably 30 to 70°C, more preferably 45 to 55°C, and the time of the softening and anti-adhesion treatment is preferably 10 to 20 seconds, more preferably 12 to 16 seconds.

[0033] Preferably, the present invention further includes, after the softening and adhesion-preventing treatment, sequentially drying and winding up the regenerated cellulose film after the softening and adhesion-preventing treatment to obtain a regenerated cellulose base film. In the present invention, the drying temperature is preferably 100 to 150°C, more preferably 120 to 140°C, and the drying time is preferably 20 to 80 seconds, more preferably 40 to 50 seconds. In the present invention, the winding is not particularly limited, and any winding procedure well known to those skilled in the art may be used.

[0034] In the present invention, after obtaining a regenerated cellulose base film, a barrier coating material and an adhesive coating material are simultaneously applied to both sides of the regenerated cellulose base film to form a barrier layer and an adhesive layer, respectively, thereby obtaining a cellulose film that combines barrier properties and heat-sealing properties.

[0035] In the present invention, the simultaneous double-sided coating preferably includes the steps of pumping a barrier coating material and an adhesive coating material into a first coating tank and a second coating tank, respectively, using a pneumatic diaphragm pump, and simultaneously coating the regenerated cellulose base film on both sides using an anilox roll coating. In the present invention, the running speed of the anilox roll coating is preferably 70 to 95 m / min, more preferably 75 to 90 m / min, and even more preferably 80 to 85 m / min. In the present invention, the mesh number of the anilox roll used for anilox roll coating of the barrier coating material is preferably 100 to 250 mesh, more preferably 150 to 200 mesh, and the coating amount of the barrier coating material in a dry state is preferably 3 to 5 g / m. 2 , more preferably 3.5 to 4.5 g / m 2 , and more preferably 4 g / m 2 In the present invention, the mesh number of the anilox roll used to apply the adhesive coating is preferably 100 to 180 mesh, more preferably 130 to 150 mesh, and the coating amount of the adhesive coating in a dry state is preferably 4 to 7 g / m 2 , more preferably 4.5 to 6.5 g / m 2 , and more preferably 5 to 6 g / m 2 is.

[0036] The present invention preferably further includes, after the simultaneous double-sided coating is completed, drying the resulting wet cellulose film having both barrier and heat-sealing properties, followed by cooling and winding to obtain a cellulose film having both barrier and heat-sealing properties. In the present invention, the drying preferably includes pre-drying and drying performed sequentially. In the present invention, the pre-drying preferably includes infrared drying, and the pre-drying temperature is preferably 60 to 80°C, more preferably 70°C, and the pre-drying time is preferably 1.2 to 1.8 s, more preferably 1.4 to 1.5 s. In the present invention, the drying temperature is preferably 60 to 120°C, more preferably 85 to 120°C. In the present invention, the drying preferably includes horizontal drying, which is divided into eight zones, designated Zone 1 to Zone 8, in order. In the present invention, the temperature of Zone 1 is preferably 85 to 95°C, more preferably 90°C, and the drying time of Zone 1 is preferably 2.7 to 3.2 s, more preferably 2.8 to 3.0 s. In the present invention, the temperature in zone 2 is preferably 95 to 105°C, more preferably 100°C, and the drying time in zone 2 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, the temperature in zone 3 is preferably 105 to 115°C, more preferably 110°C, and the drying time in zone 3 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, the temperature in zone 4 is preferably 105 to 120°C, more preferably 110 to 115°C, and the drying time in zone 4 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, the temperature in zone 5 is preferably 95 to 105°C, more preferably 100°C, and the drying time in zone 5 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, the temperature in the zone 6 is preferably 85 to 100° C., more preferably 90 to 95° C., and the drying time in the zone 6 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds.In the present invention, the temperature of zone 7 is preferably 80 to 98°C, more preferably 90 to 95°C, and the drying time in zone 7 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, the temperature of zone 8 is preferably 85 to 95°C, more preferably 88 to 93°C, and the drying time in zone 8 is preferably 2.7 to 3.2 seconds, more preferably 2.8 to 3.0 seconds. In the present invention, during the drying process, the barrier heat seal side of the wet cellulose film, which combines barrier and heat seal properties, is located underneath, and the adhesive layer side is located on top. In the present invention, during the drying process, the regenerated cellulose base film curls to one side due to differences in the properties of the emulsion coated on both sides of the regenerated cellulose base film and the amount of emulsion coated in the dry state, preventing the coating process from proceeding normally. In the present invention, pre-drying and horizontal drying are employed, and by controlling the temperature and speed of eight zones, stress on both sides of the regenerated cellulose base film is balanced and the film is wound up flat. In the present invention, the temperature of the cooling laminating roll for cooling and winding is preferably 20 to 25°C, more preferably 22 to 23°C.

[0037] The present invention provides a use in the packaging field of a cellulose film having both barrier and heat-sealing properties as described in the above technical solution, or a cellulose film having both barrier and heat-sealing properties obtained by the manufacturing method as described in the above technical solution. The cellulose film having both barrier and heat-sealing properties provided by the present invention can be directly thermocompression bonded to paper products and to some extent meets the adhesive strength requirements of laminated paper. At the same time, the cellulose film having both barrier and heat-sealing properties provided by the present invention has high moisture and oxygen barrier properties, and good aroma retention, freshness retention, and moisture resistance. Furthermore, the cellulose film having both barrier and heat-sealing properties provided by the present invention can also be thermocompression bonded to itself, has high bag-making sealing strength, and has very good application prospects as a packaging material.

[0038] The technical solutions of the present invention will be described clearly and completely below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative work fall within the technical scope of the present invention.

[0039] Example 1 (1) Cotton pulp and wood pulp were uniformly mixed in a mass ratio of 1:3, and the resulting mixed pulp was uniformly mixed with a 17.5 wt% sodium hydroxide solution in a volume ratio of 1:28 and alkalized at 45°C for 30 minutes. The resulting alkali cellulose and CS2 were uniformly mixed in a mass ratio of 1:0.28 and yellowed at 20°C for 60 minutes to obtain a fiber viscose stock solution. The fiber viscose stock solution was then poured into dilute sulfuric acid (concentration 12 wt%) through a casting die and acid-coagulated at 50°C to obtain regenerated cellulose. The regenerated cellulose was sequentially washed with water, desulfurized at 80°C in an alkaline solution with a concentration of 1.5 g / L, washed with water, bleached in a sodium hypochlorite solution with a pH value of 9, dechlorinated by placing in soft water at room temperature, washed with water, and then immersed in a softening bath. After softening in a triethylene glycol-nanoscale silica aqueous dispersion at 50°C for 8 seconds, it was dried at 130°C, conditioned, and wound up to a moisture content of 6.0% and a basis weight of 30 g / m. 2 A regenerated cellulose-based film of the above formula was obtained, in which the concentration of triethylene glycol in the triethylene glycol-nanosilica aqueous dispersion was 30 g / L, the particle size of nanosilica was 80 nm, and the concentration was 1.5 g / L. (2) Soft water and wax anti-adhesion agent (BASF wax emulsion, Poligen WE-1) were mixed in a mass ratio of 1:0.3 and stirred at 1000 r / min for 10 minutes. The resulting wax anti-adhesion agent solution and DSM aqueous acrylate emulsion were stirred at 200 r / min for 10 minutes to obtain an adhesive coating. The adhesive coating was stored at 200 r / min for use. The mass ratio of the acrylate emulsion to the wax anti-adhesion agent in the adhesive coating was 100:0.5, and the solid content of the adhesive coating was 42%. After uniform stirring, the adhesive coating was stirred at a speed of 200 r / min and stored for use. (3) Soft water and wax anti-adhesion agent (BASF wax emulsion, Poligen WE-1) were mixed in a mass ratio of 1:0.3 and stirred at 1000 r / min for 10 minutes. The resulting wax anti-adhesion agent solution, PVDC emulsion (purchased from Solvay, USA) and anti-adhesion agent were stirred at 200 r / min for 10 minutes to obtain a barrier paint, which was stored at 200 r / min for further use. The mass ratio of the PVDC emulsion to the wax anti-adhesion agent in the barrier paint was 100:1.5, and the solid content of the barrier paint was 40%. (4) Simultaneous double-sided coating: Using a pneumatic diaphragm pump, the barrier coating material and the adhesive coating material are pumped into the first coating tank and the second coating tank, respectively, and then simultaneously coated onto the regenerated cellulose base film using an anilox roll coating method to obtain a wet cellulose film with both barrier and heat-sealing properties. The running speed is 90 m / min, the mesh number of the anilox roll used to coat the barrier coating material is 250 mesh, and the coating amount in the dry state is 2.5 g / m. 2 The mesh number of the anilox used to apply the adhesive coating is 150 mesh, and the amount of coating in the dry state is 6 g / m 2 It was. (5) The wet cellulose film having both barrier and heat-sealing properties was dried by infrared rays at 60°C for 1.3 seconds, then placed in a drying tunnel and dried by a horizontal drying method using hot air, cooled at a temperature of 20°C on a cooling laminating roll, and wound up to obtain a cellulose film having both barrier and heat-sealing properties. The horizontal drying conditions are shown in Table 1. [Table 1] According to GB / T24695-2009 test method, the performance test result of cellulose film with both barrier and heat seal properties: basis weight 40g / m 2 The longitudinal tensile strength is 36.85N / 15mm, the longitudinal elongation is 18.36%, the adhesive strength between the adhesive layer and the paper product is 6.58N / 15mm, the adhesive strength of the adhesive layer itself is 7.3N / 15mm, and the oxygen permeability is 5mL / (m 224h), water vapor permeability is 12g / (m 2 The surface tension of the barrier layer was 42 dynes and the water content was 5.2 wt%.

[0040] Example 2 A cellulose film having both barrier properties and heat sealability was produced according to the method of Example 1, with the following differences from Example 1. In step (1), the basis weight of the regenerated cellulose base film is 40 g / m 2 The concentration of triethylene glycol was 40 g / L, and the concentration of nanoscale silica was 3 g / L. In step (2), the mass ratio of the acrylate emulsion to the wax anti-adhesion agent in the adhesive coating was 100:1, and the solid content of the adhesive coating was 42%. In step (3), the mass ratio of PVDC emulsion to wax anti-adhesion agent in the barrier paint was 100:1, and the solid content of the barrier paint was 40%. In step (4), the running speed is 80 m / min, the mesh number of the anilox roll used to apply the barrier paint is 200 mesh, and the coating amount in the dry state is 3 g / m 2 The mesh number of the anilox roll used to apply the adhesive coating is 100 mesh, and the coating amount in the dry state is 6.5 g / m 2 It was. In step (5), the infrared drying temperature was 70°C, the time was 1.5 s, and the temperature of the cooling lamination roll was 23°C. According to GB / T24695-2009 test method, the performance test result of cellulose film with both barrier and heat seal properties: basis weight 50g / m 2 The longitudinal tensile strength is 52.63N / 15mm, the longitudinal elongation is 22.34%, the adhesive strength between the adhesive layer and the paper product is 7.21N / 15mm, the adhesive strength of the adhesive layer itself is 7.8N / 15mm, and the oxygen permeability is 3.8mL / (m 2 24h), water vapor permeability is 9g / (m 2 The surface tension of the barrier layer was 42 dynes and the water content was 5.5 wt%.

[0041] Example 3 A cellulose film having both barrier properties and heat sealability was produced according to the method of Example 1, with the following differences from Example 1. In step (1), the basis weight of the regenerated cellulose base film is 50 g / m 2 , the concentration of triethylene glycol was 50 g / L, and the concentration of nanoscale silica was 5 g / L. In step (2), the mass ratio of the acrylate emulsion to the wax anti-adhesion agent in the adhesive coating was 100:1.5, and the solid content of the adhesive coating was 42%. In step (3), the mass ratio of PVDC emulsion to wax anti-adhesion agent in the barrier paint was 100:2, and the solid content of the barrier paint was 40%. In step (4), the running speed is 75 m / min, the mesh number of the anilox roll used to apply the barrier paint is 150 mesh, and the coating amount in the dry state is 4 g / m 2 The mesh number of the anilox used to apply the adhesive coating is 150 mesh, and the applied amount in the dry state is 6 g / m 2 It was. In step (5), the infrared drying temperature was 70°C, the time was 1.6 s, and the temperature of the cooling lamination roll was 25°C. The horizontal drying conditions are shown in Table 2. [Table 2] According to GB / T24695-2009 test method, the performance test result of cellulose film with both barrier and heat seal properties: basis weight 60g / m 2 The longitudinal tensile strength is 73.26N / 15mm, the longitudinal elongation is 43.65%, the adhesive strength between the adhesive layer and the paper product is 7.83N / 15mm, the adhesive strength of the adhesive layer itself is 8.31N / 15mm, and the oxygen permeability is 2.8mL / (m 2 24h), water vapor permeability is 7g / (m 2 The surface tension of the barrier layer was 42 dynes and the water content was 5.4 wt%.

[0042] Comparative Example 1 A cellulose film having both barrier properties and heat sealability was produced according to the method of Example 3, with the following differences from Example 1. In step (1), the basis weight of the regenerated cellulose base film is 50 g / m 2 , the concentration of triethylene glycol was 50 g / L, and the concentration of nanoscale silica was 5 g / L. The adhesive paint in step (2) was replaced with a barrier paint in step (3). In step (4), a barrier coating was applied to both sides. The mesh number of the anilox roll used was 200 mesh, and the coating amount in the dry state on both sides was 2.5 g / m. 2 It was. In step (5), the temperature of infrared drying was 80°C and the time was 1.6 s. According to GB / T24695-2009 test method, the performance test result of cellulose film with both barrier and heat seal properties: basis weight 60g / m 2 The longitudinal tensile strength is 70.26N / 15mm, the longitudinal elongation is 41.65%, the adhesive strength between the adhesive layer and the paper product is 0N / 15mm, the adhesive strength of the barrier layer itself is 1.9N / 15mm, and the oxygen permeability is 6mL / (m 2 24h), water vapor permeability is 25g / (m 2 The surface tension of both barrier layers was 42 dynes and the water content was 5.4 wt%.

[0043] As can be seen from the comparison between Example 3 and Comparative Example 1, compared to the technology of the present invention, the adhesive strength between the cellulose film with barrier and heat-sealing properties produced in Comparative Example 1 and the paper product, as well as the adhesive strength of the film itself, do not meet the requirements for laminated paper composite products and are not suitable for use in special application scenarios.

[0044] The above are only preferred embodiments of the present invention, and those skilled in the art may make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the protection scope.

Claims

1. A method for producing a cellulose film having both barrier and heat-sealing properties, comprising sequentially stacking a barrier layer, a regenerated cellulose base film, and an adhesive layer, the method comprising: The barrier layer is formed of a barrier paint prepared from a polyvinylidene chloride emulsion, a first anti-adhesion agent, and water, the first anti-adhesion agent including one or both of a wax anti-adhesion agent and a silica powder anti-adhesion agent, and the particle size of the first anti-adhesion agent is 100 to 300 nm; A method for producing a cellulose film having both barrier properties and heat sealability, characterized in that the adhesive layer is formed from an adhesive coating material produced from an emulsion, a second anti-adhesion agent, and water, the emulsion containing an acrylate emulsion and / or a polyurethane emulsion, the second anti-adhesion agent containing one or both of a wax anti-adhesion agent and a silica powder anti-adhesion agent, and the particle size of the second anti-adhesion agent is 100 to 300 nm.

2. The method for producing a cellulose film having both barrier properties and heat sealability, as described in claim 1, characterized in that the mass ratio of the regenerated cellulose base film, the barrier layer, and the adhesive layer is 77-87:4-8:9-15.

3. 3. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 1, wherein the cellulose film having both barrier properties and heat-sealing properties has a moisture content of 5 to 6%.

4. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 1 or 2, characterized in that the mass ratio of the polyvinylidene chloride emulsion to the first anti-adhesion agent in the barrier coating material is 100:1 to 100:

3.

5. 5. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 4, wherein the solid content of the polyvinylidene chloride emulsion is 30 to 45%.

6. 6. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 1, 2 or 5, wherein the thickness of the barrier layer is 2 to 7 μm.

7. The method for producing a cellulose film having both barrier properties and heat sealability according to claim 1 or 2, characterized in that the mass ratio of the acrylate emulsion to the second anti-adhesion agent in the adhesive coating material is 100:0.5 to 1.

5.

8. 8. The method for producing a cellulose film having both barrier properties and heat sealability according to claim 7, wherein the solid content of the acrylate emulsion is 30 to 45%.

9. 2. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 1, wherein the thickness of the adhesive layer is 4 to 7 μm.

10. The basis weight of the regenerated cellulose base film is 30 to 60 g / m ２ 3. The method for producing a cellulose film having both barrier properties and heat-sealing properties according to claim 1 or 2, wherein the cellulose film is

11. The method for producing a cellulose film having both barrier properties and heat sealability according to claim 10, wherein the thickness of the regenerated cellulose base film is 20 to 40 μm.

12. A method for producing a cellulose film having both barrier and heat-sealing properties, as described in claim 1, characterized in that it includes the steps of simultaneously applying a barrier paint and an adhesive paint to both sides of a regenerated cellulose base film to form a barrier layer and an adhesive layer, respectively, thereby obtaining a cellulose film having both barrier and heat-sealing properties.

13. 13. The method of claim 12, wherein the simultaneous double-sided coating comprises using a pneumatic diaphragm pump to pump the barrier coating and the adhesive coating into a first coating tank and a second coating tank, respectively, and using an anilox roll to simultaneously coat the regenerated cellulose base film on both sides.

14. The running speed of the anilox roll for coating is 70 to 95 m / min, The mesh number of the anilox roll used to apply the barrier coating is 100 to 250 mesh, and the coating amount of the barrier coating in a dry state is 3 to 5 g / m ２ and The mesh number of the anilox roll used to apply the adhesive coating is 100 to 180 mesh, and the amount of the adhesive coating applied in a dry state is 4 to 7 g / m ２ The method according to claim 13, wherein

15. 13. The method of claim 12, further comprising the steps of drying, cooling and winding up the resulting wet cellulose film having both barrier and heat-sealing properties after the simultaneous double-side coating.

16. 16. The method of claim 15, wherein the drying step includes sequentially performing pre-drying and drying, the pre-drying step includes infrared drying, the pre-drying step is performed at a temperature of 60 to 80°C for a time of 1.2 to 1.8 seconds, and the drying step is performed at a temperature of 60 to 120°C.

17. The method according to claim 16, wherein the drying is horizontal drying, the horizontal drying is divided into eight zones, which are designated as zones 1 to 8 in order, and the temperature of zone 1 is 85 to 95°C, the temperature of zone 2 is 95 to 105°C, the temperature of zone 3 is 105 to 115°C, the temperature of zone 4 is 105 to 120°C, the temperature of zone 5 is 95 to 105°C, the temperature of zone 6 is 85 to 100°C, the temperature of zone 7 is 80 to 98°C, and the temperature of zone 8 is 85 to 95°C.

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