阅读说明：本技术 一种奶制品包装盖膜 (Dairy product packaging cover film ) 是由 齐家鹏 李全布 黄湘晖 陈波 翟庆盼 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种奶制品包装盖膜,包括印刷层、阻隔层、底涂层和热封层,所述印刷层为聚氨酯树脂油墨层或硝化棉树脂油墨层,印刷层的厚度为1～3μm；所述阻隔层为铝箔层,阻隔层的厚度为20～50μm；所述底涂层为烯烃-丙烯酸酯-丙烯酸共聚树脂层,涂胶量为0.5～1g/m<Sup>2</Sup>；所述热封层由丙烯酸酯单体、苯乙烯、马来酸酐和助剂构成,热封层的涂胶量为3～7g/m<Sup>2</Sup>；印刷层在阻隔层的一面印刷,底涂层和热封层在阻隔层另一面依次涂覆。本发明提供一种制造成本低、环保可回收的用于奶制品包装的盖膜。(The invention discloses a milk product packaging cover film which comprises a printing layer, a blocking layer, a bottom coating and a heat sealing layer, wherein the printing layer is a polyurethane resin ink layer or a nitrocellulose resin ink layer, and the thickness of the printing layer is 1-3 mu m; the barrier layer is an aluminum foil layer, and the thickness of the barrier layer is 20-50 microns; the primer layer is an olefin-acrylate-acrylic acid copolymer resin layer, and the glue coating amount is 0.5-1 g/m 2 (ii) a The heat sealing layer is composed of acrylate monomer, styrene, maleic anhydride and auxiliary agentThe glue coating amount is 3-7 g/m 2 (ii) a The printing layer is printed on one side of the barrier layer, and the base coat and the heat sealing layer are sequentially coated on the other side of the barrier layer. The invention provides the cover film for the milk product package, which is low in manufacturing cost, environment-friendly and recyclable.)

1. The packaging cover film for the dairy product comprises a printing layer, a blocking layer, a bottom coating and a heat sealing layer, and is characterized in that the printing layer is a polyurethane resin ink layer or a nitrocellulose resin ink layer, and the thickness of the printing layer is 1-3 mu m; the barrier layer is an aluminum foil layer, and the thickness of the barrier layer is 20-50 microns; the primer layer is an olefin-acrylate-acrylic acid copolymer resin layer, and the glue coating amount is 0.5-1 g/m²(ii) a The heat-sealing layer is composed of an acrylate monomer, styrene, maleic anhydride and an auxiliary agent, and the coating amount of the heat-sealing layer is 3-7 g/m²(ii) a The printing layer is printed on one side of the barrier layer, and the base coat and the heat sealing layer are sequentially coated on the other side of the barrier layer.

2. The milk product packaging cover film according to claim 1, wherein the heat-sealing layer comprises, by mass: the content of the acrylate monomer is 70-90%, the content of the styrene is 8-20%, the content of the maleic acid glycoside is 0.5-3%, and the content of the auxiliary agent is 1.5-10%; wherein the acrylate monomers include BMA and MMA.

3. The dairy packaging cover film of claim 2, wherein the acrylate monomer is present in a molar ratio of BMA to MMA of 2 to 1.

4. The milk product packaging cover film according to claim 3, wherein the auxiliary agent accounts for the following mass percent of the heat sealing layer: 5-8% of fumed silica, 0.3-0.5% of wax powder and 0-3% of antibacterial agent.

5. A milk product packaging cover film according to claim 4, characterized in that the fumed silica is hydrophobic silica and has a specific surface area of 200 ± 25m²/g。

6. The milk product packaging cover film of claim 5, wherein the main component of the base coat is methacrylic acid-methyl methacrylate-butyl methacrylate-styrene-butadiene copolymer.

7. The milk product packaging cover film according to claim 6, wherein the antibacterial agent is one or two of a soy protein polypeptide antibacterial agent and a lactoferrin B antibacterial agent.

Technical Field

The invention relates to the technical field of food packaging, in particular to a dairy product packaging cover film.

Background

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the cover film for packaging the dairy products, which has the advantages of low manufacturing cost, antibacterial function, environmental protection, safety and good effect of easily tearing the cover film and the cup body.

In order to achieve the purpose, the technical scheme of the invention is to design a milk product packaging cover film, which comprises a printing layer, a blocking layer, a bottom coating and a heat sealing layer, wherein the printing layer is a polyurethane resin ink layer or a nitrocellulose resin ink layer, and the thickness of the printing layer is 1-3 μm; the barrier layer is an aluminum foil layer, and the thickness of the barrier layer is 20-50 microns; the primer layer is an olefin-acrylate-acrylic acid copolymer resin layer, and the glue coating amount is 0.5-1 g/m²(ii) a The heat-sealing layer is composed of an acrylate monomer, styrene, maleic anhydride and an auxiliary agent, and the coating amount of the heat-sealing layer is 3-7 g/m²(ii) a The printing layer is printed on one side of the barrier layer, and the base coat and the heat sealing layer are sequentially coated on the other side of the barrier layer.

Compared with the gluing mode of one-time gluing in the prior art, the gluing mode of combining the base coating and the heat sealing layer greatly saves cost, the base coating uses the olefin-acrylic resin copolymer resin to prime and enhance the adhesive force between the glue layer and the aluminum foil layer, the second layer uses the acrylic resin to be well heat-sealed with the substrates such as PS, PP, PVC and the like, the using amount of the olefin-acrylic resin glue is reduced, and the manufacturing cost is remarkably saved. Due to the influence of various factors in the production process of the aluminum foil, the aluminum foil with the thickness less than 20 mu m has pinhole defects when being used for food packaging, and the barrier property of the aluminum foil is influenced.

The polyacrylic resin has the advantages of low cost, mature production process, good glossiness, strong adhesive force, good weather resistance and the like, common packaging films mainly adopt a heating sealing mode for structures such as polyester, polypropylene and the like, and the heat sealing temperature of the cover film of the dairy product is about 90 ℃.

As a preferred technical scheme, the heat-sealing layer comprises the following components in percentage by mass: the content of the acrylate monomer is 70-90%, the content of the styrene is 8-20%, the content of the maleic acid glycoside is 0.5-3%, and the content of the auxiliary agent is 1.5-10%; wherein the acrylate monomers include BMA and MMA.

According to a preferred technical scheme, the dosage of the acrylic monomer BMA to MMA is 2 to 1. MMA can prevent the emulsion from self-adhesion after coating, and the heat sealing strength of the film is increased; while BMA increases the flexibility of the chain, improves the leveling properties of the emulsion and the flexibility of the film. With the increase of MMA and styrene in the hard monomer, the glass transition temperature of the polymer is increased, and the strength is reduced when the polymer is subjected to heat sealing at 90 ℃; too much BMA in the soft monomer will make the coating strongly self-adhesive at room temperature, so a reasonable monomer ratio of 2:1 is used.

As a preferred technical scheme, the auxiliary agent comprises the following components in percentage by mass: 5-8% of fumed silica, 0.3-0.5% of wax powder and 0-3% of antibacterial agent. The wax powder is the winning PP wax powder, the fumed silica is commercially available, the hydrophobic silica is modified by a dichlorosilane coupling agent, and the primary particle size is 12 nm.

The hydrophobic silica increases steric hindrance between silica particles, so that the hydrophobic silica can be well dispersed in an organic medium, and the compatibility between the silica and the organic dispersion medium is enhanced. The fumed silica is dispersed in the gaps among the polymer molecular chains to connect the polymer molecular chains together, so that the relative motion resistance of the polymer molecular chains is increased, and the toughness, strength and ductility of the polyester resin are improved. Meanwhile, as the diameter of the fumed silica particles is nano-scale, the product becomes smoother due to the small-size effect of the fumed silica particles, and the wear resistance is greatly improved. The gas-phase silicon dioxide is added into the heat sealing layer, and no adhesive residue exists on the cup body in the separation process of the cover film and the cup body, so that the tearing effect of the cover film is improved.

Preferably, the fumed silica is hydrophobic and has a specific surface area of 200. + -.25 m²/g。

Preferably, the antibacterial agent is one or two of a soybean protein polypeptide antibacterial agent and a lactoferrin B antibacterial agent. And adding a small amount of antibacterial agent into the heat-sealing layer, wherein the antibacterial agent is a food-grade antibacterial agent. When the cover film is used for packaging milk products stored at normal temperature, the cover film has a good antibacterial effect, and the usage amount of preservatives in the milk products can be reduced. The antibacterial peptide is an oligopeptide consisting of 10-60 amino acid residues and having biological activity, the cationic peptide is abundant, and the antibacterial peptide serving as the antibacterial agent has the advantages of high thermal stability, strong water solubility, wide antibacterial spectrum, high efficiency, multiple antibacterial targets, no side effect on normal human bodies and the like. In addition, antimicrobial peptides can also reduce the incidence of cancer. The soybean protein antibacterial polypeptide (GAP) is an alkaline peptide in glycinin, and has good antibacterial effect on Staphylococcus aureus, Escherichia coli, etc.

As a preferable technical scheme, the main component of the bottom coating is methacrylic acid-methyl methacrylate-butyl methacrylate-styrene-butadiene copolymer. The primary procurement companies include VP4311E, VP4322E, VP4174E and VP4294E of the Woodson company of Germany, and ACTEseal-HSC-170E1 and ACTEseal-HSC-176-1 of the ATTACA company of Germany.

The invention has the advantages and beneficial effects that: the cover film adopts a double-layer gluing process, the bottom layer adopts an olefin-acrylic resin layer, and the heat sealing layer adopts acrylic resin added with fumed silica, so that the use amount of an olefin-acrylic resin adhesive with high price is reduced, and the production cost is reduced; the invention reduces the thickness of the cover film and improves the flatness of the cover film; the cover film has good bonding performance and easy tearing performance with the PS cup and the PP cup, and the torn part has high flatness and no burr feeling; the PVC auxiliary agent is not added into the cover film, so that the safety and the environmental protection performance of the cover film are improved; the soybean polypeptide antibacterial agent and the lactoferrin B are added to cover the smell of the acrylic resin, so that the heat sealing layer has a good antibacterial effect.

Detailed Description

The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.