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CN-120422538-B - Double-sided heat-seal BOPP extinction film and preparation method thereof

CN120422538BCN 120422538 BCN120422538 BCN 120422538BCN-120422538-B

Abstract

The invention relates to the technical field of extinction films, in particular to a double-sided heat-seal BOPP extinction film and a preparation method thereof, wherein the extinction heat-seal layer, a supporting layer and a corona heat-seal layer are sequentially arranged, the thickness of the BOPP extinction film is 10-50 mu m, and the thickness ratio of the extinction heat-seal layer to the supporting layer to the corona heat-seal layer is (1-4) (2-8) (1-4). The production method provided by the invention is produced by a three-layer coextrusion casting process-two-way stretching process, and has the advantages of simple manufacture, low cost, abundant raw material sources and environmental friendliness.

Inventors

  • CHEN TAO
  • YANG DUO
  • Yu Mengliu
  • Luan Hanyu
  • Kang Deao
  • CHEN WEISHUO

Assignees

  • 广东江宏新材料有限公司

Dates

Publication Date
20260512
Application Date
20250430

Claims (7)

  1. 1. The double-sided heat-seal BOPP extinction film is characterized by comprising an extinction heat seal layer, a supporting layer and a corona heat seal layer which are sequentially arranged, wherein the thickness of the BOPP extinction heat seal layer is 10-50 mu m, and the thickness ratio of the extinction heat seal layer to the supporting layer to the corona heat seal layer is (1-4): 2-8): 1-4; The extinction heat sealing layer comprises, by weight, 100% of raw material components including 20% -50% of ternary random copolymer polypropylene, 0% -30% of binary random copolymer polypropylene, 30% -70% of high-density polyethylene, 1% -5% of an opening slipping agent, 0% -0.2% of a nucleating agent and 1% -10% of a compatilizer; The supporting layer comprises, by weight, 100% of raw material components, 70% -100% of homo-polypropylene, 0% -30% of block-copolymerized polypropylene, 0% -0.2% of nucleating agent, 1% -10% of compatilizer, and 7% -10% of balance-linking agent and 3% -5% of modified filler; the corona heat seal layer comprises, by weight, 100% of raw material components including 0% -100% of ternary random copolymer polypropylene, 0% -50% of binary random copolymer polypropylene, 0% -0.2% of nucleating agent and 1% -10% of compatilizer; The preparation method of the balance and linkage agent comprises the following steps: S01, adding 4-7 parts by weight of carboxymethyl cellulose and 1-3 parts by weight of nano silica sol into 5-8 parts by weight of cerium nitrate solution, then adding 2-3 parts by weight of silane coupling agent, and uniformly stirring to obtain modified carboxymethyl cellulose liquid; s02, preheating the nano titanium oxide for 1h at 55-60 ℃ to obtain preheated nano titanium oxide; Stirring the preheated nano titanium oxide and the modified carboxymethyl cellulose liquid according to the weight ratio of 3:5, and obtaining the carboxymethyl cellulose-nano titanium dioxide joint regulating liquid after stirring; s03, mixing a balance and balance agent of the mixed zinc oxide whisker/sodium alginate and carboxymethyl cellulose-nano titanium dioxide joint debugging liquid according to a weight ratio of 5 (2-3), performing ball milling at a ball milling rotating speed of 1500r/min for 1h, performing suction filtration after ball milling, and drying to obtain the balance and balance agent; the preparation method of the balance and match agent of the mixed zinc oxide whisker/sodium alginate comprises the following steps: Adding 5-8 parts by weight of zinc oxide whisker and 2-4 parts by weight of sodium alginate powder into 4-7 parts by weight of yttrium nitrate solution with the mass fraction of 5%, then adding 2-3 parts by weight of boron oxide and 0.4-0.5 part by weight of glass fiber, uniformly stirring, and performing suction filtration and drying to obtain a balance and match agent of the mixed zinc oxide whisker/sodium alginate; The preparation method of the modified filler comprises the following steps: S11, dissolving tetrabutyl titanate in absolute ethyl alcohol according to the weight ratio of (7-9), then adding a silane coupling agent KH560 accounting for 10-15% of the total amount of the tetrabutyl titanate and nano silica sol accounting for 2-5% of the total amount of the tetrabutyl titanate, and uniformly stirring to obtain a modified tetrabutyl titanate liquid; S12, placing nano attapulgite in a sodium silicate solution with the mass fraction of 5% which is 3-5 times of the total weight of the nano attapulgite, then adding urea solution with the mass fraction of 4% which is 10-15% of the total weight of the nano attapulgite, performing ball milling treatment for 2 hours, wherein the ball milling rotating speed is 1000r/min, and finishing ball milling to obtain pretreated nano attapulgite; And S13, carrying out ultrasonic modification treatment on the pretreated nano attapulgite and modified tetrabutyl titanate liquid according to a weight ratio of 5:7, wherein the ultrasonic power is 350-370W, modifying for 1h, and carrying out suction filtration and drying after modification is finished to obtain the modified filler.
  2. 2. The double-sided heat-seal BOPP matt film according to claim 1, wherein the opening slipping agent is silicon dioxide, and the particle size is 0.5-4 μm; The nucleating agent is one or more of ‌ aryl amide nucleating agent ‌, sorbitol nucleating agent, branched acid amine transparent nucleating agent, aryl phosphate transparent nucleating agent, carboxylic acid metal salt transparent nucleating agent, dehydro polar acid and salt nucleating agent thereof; The compatilizer is compounded by one or more of maleic anhydride grafting compatilizer, cyclic anhydride type compatilizer ‌, ‌ carboxylic acid type compatilizer ‌, oxazoline type compatilizer, ‌ imide type compatilizer ‌, ethylene propylene rubber, POE, EVA and isocyanate type compatilizer.
  3. 3. The double-sided heat-seal BOPP matt film according to claim 2, wherein the high density polyethylene has a melting point of 125-135 ℃ and a melt index of 5-15 g/10min at 190 ℃ and 21.6 kg; the melting point of the ternary random copolymer polypropylene is 125-135 ℃, and the melt index of the ternary random copolymer polypropylene is 2-9 g/10min at 230 ℃ and 2.16 kg; The melting point of the binary random copolymer polypropylene is 135-150 ℃, and the melt index of the binary random copolymer polypropylene at 230 ℃ and 2.16kg is 4-18 g/10min; the melting point of the homo-polypropylene is more than or equal to 160 ℃, and the melt index is 2-8 g/10min; The melting point of the selected block copolymerized polypropylene is more than or equal to 163 ℃, and the melt index is 1-8 g/10min.
  4. 4. A double sided heat seal BOPP matt film according to claim 3, characterized in that the high density polyethylene has a melt index of 6-10 g/10min at 190 ℃,21.6 kg; the melt index of the ternary random copolymer polypropylene at 230 ℃ and 2.16kg is 3-7 g/10min; the melt index of the binary random copolymer polypropylene is 6-16 g/10min at 230 ℃ and 2.16 kg; the melt index of the homo-polypropylene is 3-5 g/10min; the melt index of the selected block copolymerized polypropylene is 2-5 g/10min.
  5. 5. The double-sided heat-seal BOPP extinction film according to claim 4, wherein the mass fraction of the cerium nitrate solution is 5-8%, the silane coupling agent is silane coupling agent KH550, and the stirring speed of stirring treatment is 350-400 r/min, and stirring is carried out for 1h.
  6. 6. A method for preparing a double sided heat seal BOPP matt film as claimed in any of claims 1 to 5, comprising the steps of: (1) The raw materials of the photo-heat sealing layer, the supporting layer and the corona heat sealing layer are canceled according to the weight percentage; (2) And respectively and correspondingly putting the raw materials of the extinction heat sealing layer, the supporting layer and the corona heat sealing layer into A, B, C extruders corresponding to the three-layer coextrusion casting machine, starting up after debugging equipment according to the layer thickness proportion and the processing temperature of the extruders, preparing a sheet through a coextrusion casting process, and then carrying out biaxial stretching by adopting a double-stretching process to obtain the BOPP extinction film.
  7. 7. The method for producing a biaxially-oriented polypropylene (BOPP) matt film according to claim 6, wherein the extrusion temperature of A, B in step (2) is 240 ℃ and the extrusion temperature of 230 ℃ in the extruder, the longitudinal stretching is 115-120 ℃ at the preheating temperature, the stretching ratio is 5:1, the transverse stretching is 125-130 ℃ at the preheating zone, the stretching ratio is 10:1, and the setting temperature is 155 ℃.

Description

Double-sided heat-seal BOPP extinction film and preparation method thereof Technical Field The invention relates to the technical field of extinction films, in particular to a double-sided heat-seal BOPP extinction film and a preparation method thereof. Background The BOPP extinction film is a plastic product with low gloss and high haze diffuse reflection extinction effect, presents paper-like appearance, can realistically reproduce color during printing, provides comfortable hand feeling, and is widely applied to various packaging fields including foods, medicines, cosmetics, electronic products and the like. For example, after the extinction film is compounded with the packaging paper or the paper box, the grade of the package can be obviously improved, and the extinction film is widely applied to the fields of soap, tobacco, wine, clothing, shoes, perfume, cosmetics, medicines and the like. The BOPP extinction film is mainly prepared by adopting a multi-layer coextrusion casting and biaxial stretching process by adopting resin blending or adding an inorganic extinction agent (master batch). In the aspect of resin blending modification, in the production process, firstly, weak interfaces exist on the surface of a cast film due to poor resin blending compatibility, the weak interfaces are easily pulled apart or broken due to uneven longitudinal and transverse pulling force in the biaxial stretching process, so that a large number of bright spots appear on the surface of the film, and secondly, the spherulites are uneven in size and easy to form large spherulites due to different crystallization behaviors of different resins in the biaxial stretching process, so that the rough extinction surface of the film generates white spots. In the aspect of adding the inorganic matting agent (master batch), the weak interface is easy to be caused due to poor compatibility of the inorganic matting agent (master batch) and resin, a large number of bright spots are easy to be generated due to the fact that the weak interface is easily pulled apart in the biaxial stretching process, and white spots are easy to be generated in the film due to uneven particle size of the inorganic matting agent. In addition, the BOPP matt films are mainly heat-sealed on one side at present, but the technology of heat-sealed BOPP matt films on two sides is not reported. At present, the problems are not broken through by the related technology. Therefore, how to provide a new technology for preparing the white-spot-free bright double-sided heat-sealing BOPP matt film is a problem to be solved by the technicians in the field. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a double-sided heat-sealing BOPP extinction film and a preparation method thereof, so as to solve the problems in the prior art. The invention solves the technical problems by adopting the following technical scheme: The invention provides a double-sided heat-seal BOPP extinction film, which comprises an extinction heat seal layer, a supporting layer and a corona heat seal layer which are sequentially arranged, wherein the thickness of the BOPP extinction heat seal layer is 10-50 mu m, and the thickness ratio of the extinction heat seal layer to the supporting layer to the corona heat seal layer is (1-4) (2-8) (1-4). Preferably, the extinction heat sealing layer comprises 20-50% of ternary random copolymer polypropylene, 0-30% of binary random copolymer polypropylene, 30-70% of high-density polyethylene, 1-5% of an opening slipping agent, 0-0.2% of a nucleating agent and 1-10% of a compatilizer in percentage by weight; The supporting layer comprises 70-100% of homo-polypropylene, 0-30% of block-copolymerized polypropylene, 0-0.2% of nucleating agent and 1-10% of compatilizer in percentage by weight; The corona heat seal layer comprises, by weight, 0% -100% of ternary random copolymer polypropylene, 0% -50% of binary random copolymer polypropylene, 0% -0.2% of a nucleating agent and 1% -10% of a compatilizer. Preferably, the opening slipping agent is silicon dioxide, and the particle size is 0.5-4 mu m; the nucleating agent is one or more of an aryl amide nucleating agent, a sorbitol nucleating agent, a branched acid amine transparent nucleating agent, an aryl phosphate transparent nucleating agent, a carboxylic acid metal salt transparent nucleating agent, dehydro polar acid and a salt nucleating agent thereof; the compatilizer is compounded by one or more of maleic anhydride grafting compatilizer, cyclic anhydride type compatilizer, carboxylic acid type compatilizer, oxazoline type compatilizer, imide type compatilizer, ethylene propylene rubber, POE, EVA and isocyanate type compatilizer; preferably, the melting point of the high-density polyethylene is 125-135 ℃, the melt index is 5-15 g/10min (190 ℃ and 21.6 kg), and the melt index is preferably 6-10 g/10min; The melting point of the ternary random copolymer polypropylene is