Packaging product

Abstract

The present application provides a kind of packaging product, including body, the cavity for accommodating the packaged product is formed between the body, the body at least includes first area, the body includes selective permeable membrane at the first area, to be suitable for only water molecule can be from the side of high concentration to the side of low concentration permeable membrane, so that between the inside and outside of packaging, on the basis of gas barrier, while being able to keep the humidity of the environment in packaging proper, so as to maintain the freshness and taste of food.

Description

Technical Field

[0001] This invention belongs to the field of packaging technology, and specifically relates to a packaging product. Background Technology

[0002] In recent years, food consumption has been increasing as people's awareness of its nutritional quality has improved. To adapt to this trend, in addition to increasing production, developing effective storage and packaging technologies is an important solution. Existing packaging methods for fresh food mainly include modified atmosphere packaging (MAP) and vacuum packaging. MAP involves filling the packaging with a mixture of carbon dioxide, oxygen, and nitrogen in appropriate proportions. Oxygen maintains the shine of the food, carbon dioxide has an antibacterial effect, and nitrogen, being stable, is mainly used as a filler, thus maintaining the long-term preservation of fresh food. Vacuum packaging maintains a vacuum inside the packaging, ensuring the packaging film adheres tightly to the fresh product, isolating it from air and bacteria, thereby preserving the fresh food.

[0003] Existing modified atmosphere packaging and vacuum packaging composite films can generally provide gas barrier properties between the inside and outside of the packaging. However, fresh produce may release seepage containing blood or seawater, and the high humidity inside the packaging prevents moisture from escaping, leading to bacterial growth. Furthermore, prolonged exposure to high humidity can negatively impact the color and taste of fresh produce. In addition to the above packaging methods, for fruits, vegetables, and cooked foods, packaging materials with gas and moisture barrier functions are also used to prevent rapid moisture evaporation. However, the high humidity inside these packages can alter the texture of the food after long-term storage, significantly affecting its taste. Summary of the Invention

[0004] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a packaging product that can block gas and maintain the internal environment of the packaging at a suitable humidity level, thereby maintaining the freshness and taste of food.

[0005] The objective of this invention is achieved through the following technical solution: a packaging product comprising a body, wherein a cavity for accommodating the packaged product is formed between the bodies, the body comprising at least a first region, wherein the body comprises a selectively permeable membrane in the first region, and the method for preparing the selectively permeable membrane comprises the following steps: S1, dispersing a polymer in a solvent to prepare a polymer solution, wherein the solvent is water or a polar solvent; S2, coating the polymer solution onto the surface of a microporous substrate to form a wet film layer, wherein the polymer contains at least one polar functional group selected from -OH, -SH, -COOH, -OR, -COOR, -PO3H2, -SO3H or -NH2, to facilitate the permeability of water molecules from the side with high concentration to the side with low concentration in the first region through the selectively permeable membrane, while gas is blocked by the selectively permeable membrane.

[0006] This invention comprises at least a portion of the main body including a selectively permeable membrane. Since only water molecules can pass through the selectively permeable membrane from the side with high concentration to the side with low concentration, while satisfying the gas barrier between the inside and outside of the packaging, when the humidity inside the packaging is too high and affects the freshness or taste of the food, water molecules inside the packaging can penetrate the selectively permeable membrane and seep into the external environment, thereby reducing the humidity inside the packaging to a level most conducive to food preservation and maintaining taste. When the environment inside the packaging is too dry, causing the food to dehydrate and resulting in a decline in taste, water molecules in the external environment can penetrate the selectively permeable membrane and seep into the packaging, thereby increasing the humidity inside the packaging to a level conducive to maintaining the taste of the food.

[0007] Furthermore, in the packaging product of the present invention, the body further includes a second region, wherein the body includes an air barrier layer in the second region to be adapted to block gas in the second region.

[0008] Furthermore, in the packaging product of the present invention, the body includes a base layer, and the selectively permeable membrane is laminated to one or both surfaces of the base layer.

[0009] Furthermore, in the packaging product of the present invention, the base layer is made of a rigid material to be adapted to the body to be molded into a solidified shape.

[0010] Furthermore, in the packaging product of the present invention, the base layer is made of a soft material to suit the body to have plasticity.

[0011] Furthermore, in the packaging product of the present invention, the polymer is selected from natural, semi-synthetic, or synthetic materials.

[0012] Furthermore, in the packaging product of the present invention, the body includes a main body and a cover, wherein the cover is at least partially the first region.

[0013] Furthermore, in the packaging product of the present invention, in step S1, a functional additive is added to the polymer solution, wherein the functional additive is selected from any one or more combinations of antibacterial agents, thickeners, penetrants, crosslinking agents, and heat-sealing coatings.

[0014] Furthermore, in the packaging product of the present invention, the body further includes one or more of the following: an anti-fouling layer, an anti-abuse outer layer, an intermediate layer, and an adhesive layer.

[0015] Furthermore, in the packaging product of the present invention, the microporous substrate is a polymer microporous substrate, a ceramic microporous substrate, a paper microporous substrate, a cloth microporous substrate, a biomaterial microporous substrate, a metal microporous substrate, or a carbon fiber microporous substrate; the polymer microporous substrate is selected from natural, semi-synthetic, or synthetic materials; the metal microporous substrate is an aluminum microporous film, an aluminum microporous plate, a stainless steel microporous film, or a stainless steel microporous plate.

[0016] The present invention achieves the following effects through the above technical solution:

[0017] The present invention provides that at least a portion of the body layer includes a selectively permeable membrane, thereby maintaining appropriate humidity inside the packaging while creating a gas barrier between the inside and outside of the packaging, thus preserving the freshness and taste of the food. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the packaging product according to the first embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the packaging product according to the second embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the layer structure of the first region of the present invention;

[0021] Figure 4 This is a schematic diagram of the layer structure of the second region of the present invention;

[0022] Figure 5 This is a schematic diagram of the packaging product according to the third embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the packaging product according to the fourth embodiment of the present invention.

[0024] The reference numerals in the figure are as follows:

[0025] 1-Main body, 11-First region, 12-Second region, 2-Selective permeable membrane, 3-Base layer, 4-Gas barrier layer. Detailed Implementation

[0026] The principles and spirit of the invention will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are given merely to enable those skilled in the art to better understand and implement the invention, and are not intended to limit the scope of the invention in any way.

[0027] The packaging product of this invention includes a body 1, with cavities formed between the bodies 1 for accommodating the packaged product. Food is stored in the cavity. During conventional storage and transportation, the bodies 1 are interconnected around the cavity, thereby creating a seal between the cavity and the external environment. In the prior art, the body 1 is entirely made of moisture-proof and gas-proof materials, preventing the free flow of gas and water molecules between the cavity and the external environment. Therefore, although a vacuum environment is maintained within the cavity, preventing bacteria from the external air from flowing into the cavity and spoiling the food, or ensuring that the mixture of carbon dioxide, oxygen, and nitrogen gas filled into the cavity does not flow out into the external environment to maintain the freshness and taste of the fresh food, at the same time, the blood or seawater produced by the fresh food makes the humidity inside the cavity too high. Prolonged high humidity will accelerate the spoilage and deterioration of the fresh food and reduce its taste.

[0028] In the packaging product of this invention, the body 1 includes at least a first region 11. The body 1 includes a selectively permeable membrane 2 in the first region 11, so that only water molecules can pass through the selectively permeable membrane 2 from the side with high concentration to the side with low concentration, while still maintaining gas barrier between the cavity and the external environment. When the humidity inside the packaging is too high and affects the freshness or taste of the food, water molecules inside the packaging can penetrate the selectively permeable membrane 2 and seep into the external environment, thereby reducing the humidity inside the packaging to a level suitable for food preservation and maintaining taste. When the environment inside the packaging is too dry and causes the food to dehydrate and the taste to decline, water molecules in the external environment of the packaging can penetrate the selectively permeable membrane 2 and seep into the packaging, thereby increasing the humidity inside the packaging to a level suitable for maintaining the taste of the food.

[0029] Those skilled in the art will understand that, Figure 1 As shown, the body 1 only includes the first region 11. In this case, the entire body 1 involves the selectively permeable membrane 2, resulting in a larger moisture permeation area, higher moisture permeation efficiency, and better preservation and taste maintenance of food. In another embodiment, as shown... Figure 2 As shown, the body 1 also includes a second region 12, meaning that only a portion of the body 1 allows water molecules to pass through. Although the moisture permeability is affected, it can still fully meet packaging requirements in some situations.

[0030] In one embodiment, the body 1 further includes one or more of the following: an anti-scaling layer, an anti-abuse outer layer, an intermediate layer, an adhesive layer, etc. (not shown in the figure).

[0031] In one embodiment of the present invention, such as Figure 1As shown, the packaging product consists of two body pieces 1, which are connected to each other at their four edges to form a central cavity for storing food. The connection method between the two body pieces 1 at their four edges can be adhesive bonding, thermoforming bonding, locking bonding, or integral molding, or they can essentially only contact and seal without any adhesion.

[0032] In one embodiment of the invention, after food is placed inside the cavity, a vacuum treatment can be applied to the cavity. The body 1 prevents gases from the external environment from seeping into the cavity, thereby ensuring that the food inside the cavity can be kept fresh for a long time. In another embodiment, the cavity can be filled with a mixture of carbon dioxide, oxygen, and nitrogen to form modified atmosphere packaging. The body 1 prevents the mixed gas from seeping into the external environment, thereby ensuring that the food inside the cavity maintains its freshness and taste.

[0033] In one embodiment of the present invention, the body 1 includes a selectively permeable membrane 2. When the humidity inside the cavity rises to a level higher than that of the external environment due to blood or seawater produced by the fresh food inside, water molecules permeate through the selectively permeable membrane 2 to the external environment, thereby reducing the humidity inside the cavity and ensuring that the fresh food maintains its freshness and taste for a long time. In another embodiment, the food inside the cavity is cooked food. If the moisture it contains cannot be drained from the packaging for a long time, the high humidity inside the cavity will cause the texture and taste of the cooked food to deteriorate. After the water molecules permeate through the selectively permeable membrane 2 to the external environment, the humidity inside the cavity decreases, ensuring that the cooked food has a better taste.

[0034] In one embodiment of the present invention, only Figure 1 The body 1 on the left side is a first region 11 including a selectively permeable membrane 2, while the body 1 on the right side still maintains the moisture-proof and air-proof function of the prior art (i.e., the second region 12). In this case, water molecules exchange between the external environment and the cavity through the body 1 on the left side.

[0035] In one embodiment of the present invention, such as Figure 3 and 4 As shown, the body 1 includes a base layer 3, which provides support for the body 1. Selective permeable membranes 2 are laminated on both sides of the base layer 3. The base layer 3 can be paper-based, and trademarks or text can be printed on its surface. Because the paper base is permeable, water molecules can exchange between the cavity and the external environment through the selective permeable membranes 2 and the paper base. Those skilled in the art will understand that the base layer 3 can also be made of other materials, as long as the material is permeable. Those skilled in the art will also understand that the selective permeable membrane 2 can be laminated only on either side of the base layer 3. The selective permeable membrane 2 also serves to protect the surface of the base layer 3, preventing damage to the exposed surface of the base layer 3 caused by food inside the cavity or the external environment.

[0036] In one embodiment of the present invention, such as Figure 4As shown, the body 1 also includes an air barrier layer 4 in the second region 12. The air barrier layer 4 is composited on the surface of the selectively permeable membrane 2. The air barrier layer 4 is used to protect the selectively permeable membrane 2 and prevent the surface of the selectively permeable membrane 2 from being damaged by food or the external environment, or from aging due to long-term exposure to air, so as to affect the air barrier and moisture permeability performance.

[0037] In one embodiment of the invention, the base layer 3 is made of a rigid material, and the body 1 can be processed and maintained into any shape, such as a cuboid packaging box, etc. Figure 5 As shown, the top of the box is set as the first region 11 for water molecules to pass through, and the box body is set as the second region 12 to isolate air and moisture; those skilled in the art will understand that the entire box can also be the first region 11, thereby improving the moisture permeability.

[0038] In one embodiment of the present invention, such as Figure 6 As shown, the packaging product is cylindrical in shape, including a main body and a cover. The cover is a first region 11 for water molecules to pass through, and the main body is a second region 12 for air and moisture barrier. Those skilled in the art will understand that both the main body and the cover can be the first region 11 to improve the moisture permeability.

[0039] In another embodiment, the base layer 3 is made of a soft material, and the body layer 1 can adapt to the shape of the food when holding it, thus exhibiting strong plasticity.

[0040] The method for preparing the selectively permeable membrane 2 of the present invention includes the following steps:

[0041] S1. Disperse the selected polymer in a solvent, preferably water or a polar solvent, to prepare a polymer solution.

[0042] Optionally, different types of functional additives can be added to the prepared polymer solution to form a composite solution;

[0043] S2. The prepared polymer solution or composite solution is coated onto the surface of a selected microporous substrate to form a wet film; after hot pressing / drying, a polymer composite film is obtained.

[0044] The polymer composite membrane prepared by this invention can selectively permeate water molecules and block gases and other substances. It also has good biocompatibility and has broad application prospects.

[0045] In this embodiment of the invention, multiple selected high molecular polymers can be dissolved separately to prepare solutions, and then mixed evenly to obtain a polymer solution.

[0046] The polymers described in this invention are selected from natural, semi-synthetic, and synthetic materials, such as lignin salts, starch and its derivatives, cellulose polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose and their sodium and potassium salts, nanofibrillated cellulose (or cellulose nanofibrils, CNFs), and lignocellulose nanofibers. Nanofibrils (LCNFs), guar gum, gum arabic, gelatin, pectin, xanthan gum, casein, albumin, collagen, soy protein isolate, silk protein, polysaccharides such as chitosan, dextran, mannan, succinyl dextran, soybean polysaccharides and their derivatives, alginate, agar powder, polyacrylic acid, long-chain alkyl (carbon number: 10-30) acrylate, ethylene-acrylic acid copolymer, ethylene-vinyl alcohol copolymer and polyvinyl alcohol resin at least two of these can be combined to form a membrane layer that selectively permeates water molecules while blocking gases and other substances, that is, the membrane layer is airtight and has "dynamic" moisture permeability.

[0047] In one embodiment, the polymer of the present invention comprises an inorganic-organic hybrid formed by sol-gel technology. The raw materials for the sol-gel technology include a metal compound, a solvent, a catalyst and chelating agent, additives, and water. The metal compound may be a metal alkoxide, the solvent may be methanol, ethanol, or butanol, the catalyst and chelating agent may be hydrochloric acid, acetic acid, ammonia, EDTA, or citric acid, and the additive may be a hydrolysis control agent. Those skilled in the art will understand that inorganic-organic hybrids can also be formed through intercalation composite technology, inorganic particle surface modification, electrochemical synthesis, or assembly methods.

[0048] In one embodiment, the polymer of the present invention comprises clay filler, preferably montmorillonite, but may also include kaolinite, attapulgite, illite, bentonite, halloysite, kaolin, mica, diatomite and fullerite, calcined aluminum silicate, hydrated aluminum silicate, magnesium aluminum silicate, sodium silicate and magnesium silicate. In another embodiment, the polymer coating of the present invention may be, for example, an inorganic coating of titanium dioxide, aluminum oxide or silicon dioxide.

[0049] This invention utilizes the unique properties of various biomaterials to highlight the characteristics of membrane materials. For easier understanding, the membrane material described in this application can be considered a skin-like material. Human skin automatically adjusts its barrier and permeability functions according to different environments; the water permeability channels constructed by the composite membrane material of this invention dynamically change under different temperature and humidity conditions, thus significantly altering the water permeability.

[0050] Specifically, the polymers (synthetic or biopolymers) selected in this application contain many polar functional groups such as -OH, -SH, -COOH, -OR, -COOR, -PO3H2, -SO3H, and -NH2. These polar functional groups and various functional additives are then organically integrated and formulated to construct permeable (moisture-wicking) channels with reinforced hydrophilic-hydrophobic groups. This construction method differs from the conventional understanding of building tunnels by fixing the tunnel walls with bricks. The membrane material described in this application is affected by the surrounding temperature and humidity during use, and its internal structure, i.e., the effective chemical bond links through hydrogen bonds, ionic bonds, and / or covalent bonds, will dynamically change.

[0051] For example, as humidity and temperature increase, the efficiency of water molecules passing through the membrane increases. This reflects that the enhanced water permeability channels composed of polar hydrophilic groups and non-polar hydrophobic groups are closely related to temperature and humidity. Especially when the ambient temperature is high, more water permeability channels are dynamically formed, transporting water molecules to the other side of the membrane.

[0052] In some examples, under conditions of 20%-60% humidity and no external pressure, if the temperature is low, such as 20°C, the rate at which water molecules autonomously pass through the membrane material is basically stable. This is because at this temperature, the chemical bonds are relatively stable, and the water permeable channels are not significantly affected by the high or low humidity of the environment on the water molecule output side. However, at moderate temperatures, such as 25°C, the chemical bonds are more likely to change, and the water permeable channels will change accordingly. Therefore, water molecules will pass through at a higher speed when moving towards the membrane side with lower relative humidity, and at a lower speed when moving towards the membrane side with higher relative humidity.

[0053] Among them, lignin salts are generally lignin sulfonates, such as sodium lignin sulfonate; cellulose polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose and their sodium and potassium salts, nanofibrillated cellulose (or cellulose nanofibrils, CNFs), lignocellulose-containing cellulosic nanofibrils (LCNFs), guar gum, gum arabic, gelatin, pectin, xanthan gum, collagen, soy protein isolate, silk protein, polysaccharides such as chitosan, dextran, mannan, succinyl dextran, soybean polysaccharides and their derivatives, alginate, agar powder, polyacrylic acid, long-chain alkyl (carbon number: 10-30) acrylate ethers, ethylene / acrylic acid (EAA) copolymers, ethylene / vinyl alcohol (EVOH) copolymers and polyvinyl alcohol (PVA) resins are water-soluble or can be chemically produced from natural resources. Suitable cellulose can include hemicellulose, such as xylan, microfibrillated cellulose, microcrystalline cellulose, and nanocellulose.

[0054] The polymers selected in this invention have a molecular weight between 5,000 and 5,000,000; at least two of these polymers are selected and combined in a certain proportion, exhibiting excellent performance in blocking most substances while allowing water vapor to pass through. Furthermore, the mass percentage of the polymer in the polymer solution can be 2% to 25%, preferably 5% to 25%, for example 10%, 12%, 15%, 16%, 18%, 20%, 21%, or 24%.

[0055] In this embodiment of the invention, a selected polymer is dissolved in an aqueous medium at a predetermined time and in a predetermined order under constant temperature conditions ranging from 10 to 100°C, and the solution is thoroughly stirred to ensure complete dissolution and uniform mixing. The solvent used can be pure water, or a polar solvent selected from one, two, or more of ethanol, n-propanol, isopropanol, butanol, ethyl acetate, tetrahydrofuran, and acetonitrile.

[0056] Currently, the chemical reactions used to manufacture important compounds (such as pharmaceuticals) are almost always carried out in organic solvents, as is the case with research work aimed at inventing new compounds and developing appropriate methods to manufacture them. Historically and continuing to this day, the organic solvents used are typically volatile organic compounds (VOCs), which pose environmental problems. Their vapors in the air can contribute to the greenhouse effect, which causes global warming; in some cases, solvent vapors can catalyze the destruction of the ozone layer, which protects the Earth and its inhabitants from short-wave ultraviolet solar radiation; these vapors can also be toxic to humans, plants, or animals, or may cause disease. Therefore, this invention preferably uses water as a solvent, minimizing or eliminating the use of toxic organic solvents.

[0057] This invention utilizes the aforementioned polymers in a sustainable manner, offering a competitive advantage over oil-based polymers in terms of environmental friendliness and unique properties that conventional polymers cannot replicate. However, biopolymers typically exhibit poor mechanical properties, short fatigue life, low chemical resistance, poor long-term durability, and limited processing capabilities, which significantly restrict their industrial applications.

[0058] Depending on the specific functional requirements, in this embodiment of the invention, functional additives (organic or inorganic fillers, antibacterial agents, etc.) may be added to the solution obtained in the previous step, and the mixture is stirred thoroughly to obtain a composite solution.

[0059] In another embodiment, various additives may be contained in one or more layers of polymer used for the outer, inner, and intermediate layers of the film. Conventional antioxidants, anti-blocking additives, polymer plasticizers, gas (e.g., oxygen) scavengers, slip agents, colorants, dyes, pigments, and sensory agents may be added to one or more layers of the film, or the film may be free of such additives.

[0060] In embodiments of the present invention, the functional additive can be an organic or inorganic functional additive material, selected from at least one of antibacterial agents, thickeners, penetrants, crosslinking agents, and heat-sealing coatings; it can also be a nanoscale functional material, or a combination thereof. The nanoscale functional material can be a metal nano-oxide, such as zinc, titanium, or copper nano-oxide modified with noble metals; or it can be a nanoscale metal-supported graphene material, including graphene material supported with noble metals such as silver, platinum, or palladium; or it can be nanoscale tourmaline powder / nanoclay, or nanoclay; or it can be nanofibrillated cellulose (or cellulose nanofibrils, CNFs), or lignocellulose-containing cellulosic nanofibrils (LCNFs). Specifically, embodiments of the present invention can use nano-titanium dioxide alone, or it can be used in combination with at least one of antibacterial agents, coupling agents, graphene, etc.

[0061] In some embodiments of the present invention, the mass percentage of the functional additive (functional material) in the composite solution is preferably 0.01% to 5%, more preferably 0.05% to 4%, and even more preferably 0.1% to 3%; in other embodiments, the mass percentage of the functional additive (nanoscale functional material) in the composite solution is preferably 0.01% to 3%, more preferably 0.05% to 2.5%, and even more preferably 0.1% to 2%. The embodiments of the present invention strive to utilize the unique properties of various biomaterials to reflect the characteristics of membrane materials, thereby minimizing or avoiding the use of chemical additives.

[0062] In this embodiment of the invention, under a temperature range of 10-200°C, the pre-prepared polymer or composite solution is applied to one or both sides of the surface of a microporous substrate through one or more processes such as casting, calendering, molding, extrusion, uniaxial stretching, biaxial stretching, or various selectable coating processes to obtain a composite membrane material.

[0063] In this invention, the microporous substrate is a base material with a certain number of micropores, which can provide support for film layers formed by various polymers, similar to the function of a paper-based microporous substrate. In terms of material, the microporous substrate can be a polymer microporous substrate, a ceramic microporous substrate, a paper microporous substrate, a cloth microporous substrate, a biomaterial microporous substrate, a metal microporous substrate, or a carbon fiber microporous substrate. The microporous substrate has a pore size of 0.1-3 micrometers, a porosity of 35-90%, preferably 60-90%, and a thickness ranging from 10-350 micrometers.

[0064] The polymer in the microporous polymer substrate can be a conventional polymer or a biocompatible polymer; specifically, it can be selected from one or more of polyethylene (PE), polypropylene (PP), polyurethane (PU), polyamide (nylon), polyester (mainly poly(ethylene terephthalate) esters including polyethylene terephthalate), polyethersulfone, polyvinylidene fluoride (PVDF), polytetrafluoroethylene, cellulose, polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polyglycolic acid, and polycaprolactone. Structurally, the microporous polymer substrate is selected from natural, semi-synthetic, and synthetic materials such as nonwoven materials like traditional nonwoven fabrics, silk, pure cotton fiber, Tencel, bamboo fiber, binchotan charcoal, bio-fiber, viscose fiber, etc., and polymer breathable membranes, hollow fiber ultrafiltration membranes, microporous tubes, or microporous plates made of PE, PP, PET, PVDF, PS, PES, polyurethane, etc. Furthermore, the metal-based microporous substrate is preferably an aluminum microporous film, an aluminum microporous plate, a stainless steel microporous film, or a stainless steel microporous plate.

[0065] In some embodiments of the present invention, the microporous substrate is a polymer nonwoven material, such as a polypropylene microporous substrate or a meltblown composite breathable nonwoven material. The polymer material includes polypropylene, polyurethane, polyamide, polyester, polyethersulfone, and biocompatible nanofiber membranes, such as polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polyglycolic acid, and polycaprolactone, or copolymers composed of two or more polymers.

[0066] In other embodiments of the present invention, the microporous substrate is a breathable membrane, hollow fiber ultrafiltration membrane, tube, or plate, the polymer material of which includes polyethylene, polypropylene, polyurethane, polyamide, polysulfone, polyvinylidene fluoride, polyethylene terephthalate, polytetrafluoroethylene, cellulose, and polyethersulfone and biocompatible nanofiber membranes, such as starch compounds, polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoates (PHAs), polyglycolic acid and polycaprolactone, or copolymers composed of two or more polymers.

[0067] In this embodiment of the invention, the surface of the aforementioned microporous substrate is coated to form a wet film containing a composite solution. After drying, a composite membrane material with "dynamic" moisture permeability and airtightness is obtained. The thickness of the wet film is generally 10–300 micrometers. The drying method can be air drying at room temperature or other methods such as baking, with a temperature of 20–120°C, resulting in a dried wet film thickness of 1–100 micrometers.

[0068] In this embodiment of the invention, the polymer solution can be coated onto the surface of a specially selected microporous substrate, and then another specially selected microporous substrate can be placed on top to form a composite wet film. After hot pressing / drying, a composite membrane material with "dynamic" moisture permeability and airtightness can be obtained.

[0069] To further understand this application, the following detailed description of the polymer composite film and its preparation method provided in this application is provided in conjunction with embodiments.

[0070] The membrane material performance tests of this invention are conducted in accordance with the requirements of ASTM F 1249 and GB / T458 methods; the air permeability, moisture permeability, and antibacterial and bacteriostatic properties of the membrane material are determined by standardized test methods.

[0071] Example 1

[0072] (1) Prepare a 10% silk protein aqueous solution using purified water or ordinary water and stir until homogeneous.

[0073] (2) Prepare a 2% sodium alginate aqueous solution using purified water or ordinary water, and stir thoroughly until completely dissolved.

[0074] (3) Prepare a 10% gelatin aqueous solution with purified water or ordinary water and stir to dissolve (you can heat appropriately to help dissolve depending on the dissolution).

[0075] (4) Prepare a 3% carboxymethyl cellulose aqueous solution using purified water or ordinary water and stir thoroughly.

[0076] (5) Mix the solutions obtained in steps (1), (2), (3) and (4) in the same weight ratio in sequence until they are homogeneous.

[0077] (6) Based on the solid content of the above mixed solution, add a small amount of natamycin, nano-sized titanium dioxide and silane coupling agent A-171 (each amount is about 0.3-1% of the solid content of the solution), and then stir at 50°C for 3 hours.

[0078] (7) Apply the solution obtained in step (6) onto the surface of a polypropylene microporous substrate with a thickness of about 55 micrometers to form a polymer wet film, and dry it at room temperature to obtain a polymer composite film.

[0079] The thickness of the polymer wet film is 15 micrometers, and the film thickness after drying at room temperature is about 2-3 micrometers.

[0080] The moisture permeability of the obtained membrane material was tested to be 9240 g / m²·24hr@30℃. The air permeability of the membrane sample was tested using an FBS-TQ110 high-precision computer air permeability meter, and the air permeability was 0 μm / (Pa·s)@pressure difference 1 kPa. The tensile strength and elongation were 103 N and 211% in the longitudinal direction, and 97 N and 205% in the transverse direction. This indicates that the obtained composite membrane material has excellent performance.

[0081] Example 2

[0082] (1) Preparation of ~5% soy protein isolate aqueous solution: Add 8 parts by weight of soy protein isolate to 120 parts by weight of purified water or ordinary water and stir and heat (80°C) to dissolve. Centrifuge to separate the clear liquid and measure its solid content.

[0083] (2) Prepare a 5% chitosan aqueous solution with purified water or ordinary water and stir until dissolved.

[0084] (3) Prepare a 10% silk protein aqueous solution using purified water or ordinary water and stir well.

[0085] (4) Prepare a 10% acrylic acid aqueous solution with pure water or ordinary water and stir to dissolve.

[0086] (5) Prepare a 3% carboxymethyl cellulose aqueous solution using purified water or ordinary water and stir thoroughly.

[0087] (6) Prepare a 5% sodium lignosulfonate aqueous solution using purified water or ordinary water, and stir until dissolved.

[0088] (7) The solutions obtained in steps (1), (2), (3), (4), (5) and (6) are slowly mixed together in the same weight ratio.

[0089] (8) Based on the solid content of the above mixed solution, add a small amount of 45% benzalkonium chloride aqueous solution, nano-sized titanium dioxide, silane coupling agent A-171 and transglutaminase (each amount is about 0.5-1% of the solid content of the solution), and then stir at 50°C for 3 hours.

[0090] (9) The solution obtained in step (8) is applied to the surface of the oxygen-barrier, waterproof and oil-proof paper microporous substrate provided by Shanghai Zidan Company to form a polymer wet film. The film is then dried at room temperature to obtain a polymer composite film.

[0091] The thickness of the polymer wet film is 15 micrometers, and the film thickness after drying at room temperature is about 2-3 micrometers.

[0092] The moisture permeability of the obtained membrane material was tested to be 8978 g / m²·24hr@30℃. The air permeability of the membrane sample was tested using an FBS-TQ110 high-precision computer air permeability meter, and the air permeability was 0 μm / (Pa·s)@pressure difference 1 kPa. The tensile strength and elongation were 75 N and 165% in the longitudinal direction, and 70 N and 152% in the transverse direction. This indicates that the obtained composite membrane material has excellent performance.

[0093] Example 3

[0094] (1) Prepare a 10% silk protein aqueous solution using purified water or ordinary water and stir until homogeneous.

[0095] (2) Prepare a 5% soybean polysaccharide aqueous solution using purified water or ordinary water and stir well.

[0096] (3) Prepare a 10% gelatin aqueous solution with purified water or ordinary water and stir to dissolve (you can heat appropriately to help dissolve depending on the dissolution).

[0097] (4) Prepare a 6% polyvinyl alcohol aqueous solution using purified water or ordinary water and stir until homogeneous.

[0098] (5) Mix the solutions obtained in steps (1), (2), (3) and (4) in the same weight ratio in sequence until they are homogeneous.

[0099] (6) Based on the solid content of the above mixed solution, add a small amount of carboxymethyl cellulose, silane coupling agent A-171, organosilicon quaternary ammonium salt, nano-sized titanium dioxide, and lignocellulose nanofibers (each amount is approximately 0.3-1% of the solid content of the solution), and stir thoroughly. Then continue stirring at 50°C for 3 hours.

[0100] (7)A) Apply the solution obtained in step (6) onto the surface of a 20-micrometer-thick polypropylene microporous substrate and air dry at room temperature to obtain a polymer composite film.

[0101] The tested membrane material exhibits a moisture permeability of 8875 g / m²·24hr@30℃. Before and after the moisture permeability test, the air permeability of the membrane sample was measured using an FBS-TQ110 high-precision computer air permeability meter, with permeabilities of 0 μm / (Pa·s) and 0.06 μm / (Pa·s)@1 kPa pressure difference, respectively. The tensile strength and elongation were 92 N and 187% longitudinally, and 85 N and 180% transversely, respectively. The antibacterial rate was 99.9% (GB / T31402-2015), and the mildew resistance was grade 0 (ISO 16869:2008 / GB / T24128-2018). These results indicate that the obtained composite membrane material has excellent performance.

[0102] B) Apply the solution obtained in step (6) onto the surface of the oxygen-barrier, waterproof and oil-proof paper microporous substrate provided by Shanghai Zidan Company to form a polymer wet film, and dry it at room temperature to obtain a polymer composite film.

[0103] The moisture permeability of the obtained membrane material was tested to be 9170 g / m²·24hr@30℃. The air permeability of the membrane sample was tested using an FBS-TQ110 high-precision computer air permeability meter, and the air permeability was 0 μm / (Pa·s)@pressure difference 1 kPa. The tensile strength and elongation were 78 N and 170% in the longitudinal direction, and 70 N and 158% in the transverse direction, respectively. This indicates that the obtained composite membrane material has excellent performance.

[0104] C) Apply the solution obtained in step (6) onto the surface of a paper microporous substrate with improved paper porosity provided by Shanghai Zidan Company to form a polymer wet film, and dry it at room temperature to obtain a polymer composite film.

[0105] The moisture permeability of the obtained membrane material was tested to be 9570 g / m²·24hr@30℃. The air permeability of the membrane sample was tested using an FBS-TQ110 high-precision computer air permeability meter, and the air permeability was 1.35 μm / (Pa·s)@pressure difference 1 kPa. The tensile strength and elongation were 65 N and 160% in the longitudinal direction, and 58 N and 138% in the transverse direction, respectively. These results indicate that the obtained composite membrane material has excellent performance.

[0106] As can be seen from the above embodiments, the present invention selects at least two specific polymers and processes them through different coating processes such as roller coating, spraying, or printing to form a membrane layer with barrier properties but selective water permeability on the surface of a microporous substrate, thereby obtaining a polymer composite membrane. The polymer composite membrane obtained by the present invention can selectively permeate water molecules (i.e., dynamically permeable) and can block gases and other substances. In addition, because it uses polymers derived from nature or with water solubility, the composite membrane material has good biocompatibility, is biodegradable, and is environmentally friendly. Furthermore, the present invention can use water as a solvent, using less or no toxic organic solvents, further enhancing its environmental friendliness.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A packaging product, comprising a body (1) having cavities formed between the bodies (1) for accommodating a packaged product, characterized in that, The body (1) includes at least a first region (11), and the body (1) includes a selectively permeable membrane (2) in the first region (11). The method for preparing the selectively permeable membrane (2) includes the following steps: S1. Disperse the polymer in a solvent to prepare a polymer solution, wherein the solvent is water or a polar solvent; S2. The polymer solution is coated onto the surface of a microporous substrate to form a wet film layer, wherein the polymer contains at least one polar functional group selected from -OH, -SH, -COOH, -OR, -COOR, -PO3H2, -SO3H or -NH2, so as to allow water molecules to pass through the selectively permeable membrane (2) from the side with high concentration to the side with low concentration in the first region (11), while the gas is blocked by the selectively permeable membrane (2). The polymer solution is one of the following polymer compositions: (1) 10% silk protein aqueous solution, 2% sodium alginate aqueous solution, 10% gelatin aqueous solution, and 3% carboxymethyl cellulose aqueous solution, with a weight ratio of 1:1:1:1; (2) 5% soy protein isolate aqueous solution, 5% chitosan aqueous solution, 10% silk protein aqueous solution, 10% acrylic acid aqueous solution, 3% carboxymethyl cellulose aqueous solution, and 5% sodium lignosulfonate aqueous solution, in a weight ratio of 1:1:1:1:1:1; (3) 10% silk protein aqueous solution, 5% soybean polysaccharide aqueous solution, 10% gelatin aqueous solution, and 6% polyvinyl alcohol aqueous solution, with a weight ratio of 1:1:1:

1.

2. The packaging product according to claim 1, characterized in that: The body (1) further includes a second region (12), wherein the body (1) includes a gas barrier (4) in the second region (12) to be adapted to block gas in the second region (12) by the gas barrier (4).

3. The packaging product according to claim 1, characterized in that: The body (1) includes a base layer (3), and the selectively permeable membrane (2) is composited on one or both sides of the base layer (3).

4. The packaging product according to claim 3, characterized in that: The base layer (3) is made of a rigid material to be suitable for the body (1) to be molded into a solidified shape.

5. The packaging product according to claim 3, characterized in that: The base layer (3) is made of a soft material to make the body (1) malleable.

6. The packaging product according to claim 1, characterized in that: The polymer is selected from natural, semi-synthetic, or synthetic materials.

7. The packaging product according to claim 1, characterized in that: The body (1) includes a main body and a cover, the cover being at least partially the first region (11).

8. The packaging product according to claim 1, characterized in that: In step S1, a functional additive is added to the polymer solution. The functional additive is selected from any one or more combinations of antibacterial agents, thickeners, penetrants, crosslinking agents, and heat-sealing coatings.

9. The packaging product according to claim 1, characterized in that: The body also includes one or more of the following: an anti-scaling layer, an anti-abuse outer layer, an intermediate layer, and an adhesive layer.

10. The packaging product according to claim 1, characterized in that: The microporous substrate is a polymer microporous substrate, a ceramic microporous substrate, a paper microporous substrate, a cloth microporous substrate, a biomaterial microporous substrate, a metal microporous substrate, or a carbon fiber microporous substrate; the polymer microporous substrate is selected from natural, semi-synthetic, or synthetic materials; the metal microporous substrate is an aluminum microporous film, an aluminum microporous plate, a stainless steel microporous film, or a stainless steel microporous plate.

Images