Sheet for hose with ultrahigh brightness and high barrier property and forming process

Abstract

The invention belongs to the technical field of packaging materials, and particularly relates to a sheet for an ultrahigh-brightness and high-barrier hose and a forming process. The ultra-high-brightness and high-barrier-property sheet for the hose structurally comprises an optical layer, a first bonding layer, a functional layer, a core barrier layer, a middle functional layer, a second bonding layer and a heat sealing layer in sequence. According to the invention, specific materials are selected to prepare each layer of the sheet, the layers are combined in sequence, and then optimized dry-process compounding and extrusion compounding processes are combined, so that the prepared final sheet for the hose has ultrahigh brightness and high barrier property, also has good mechanical property and heat sealing property, and is suitable for large-scale production. The packaging box is suitable for pipe packaging in the industries of cosmetics, medicine, food and the like and has wide market application prospects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of packaging materials, and particularly relates to a sheet for a super-high-brightness and high-barrier soft tube and a forming process. BACKGROUND

[0002] In the cosmetics, pharmaceutical and food industries, the application of tube packaging is very wide. At present, there are two processes for tube materials on the market: extruded tube material and sheet tube. The extruded tube material is a tube material formed by extruding the plastic raw material through a special-shaped die after being heated and melted by an extruder, and then printing, tube sealing and other processes are performed. Although this process has high production efficiency, can quickly produce continuous tube products, and the equipment is relatively simple and convenient to operate, the appearance and functionality of the extruded tube material are relatively limited, and the subsequent printing process is mainly relied on to improve its appearance and functionality. The sheet tube is first made into a sheet, and then the finished product is completed through printing, tube welding and other links. This process has high flexibility and can perform diversified processing at the sheet stage. Foreign countries have made certain progress in sheet tube technology, which can realize the compounding of various materials and improve the barrier performance and appearance effect of the products. However, the domestic sheet compounding precision is low, which may cause the combination between the composite materials to be not tight enough, affecting the overall performance of the tube. In addition, in terms of barrier performance, the barrier effect of domestic products is often not as good as that of foreign advanced products, which cannot meet the packaging needs of some high-end products with high preservation and quality requirements.

[0003] Therefore, with the improvement of consumers' requirements for the appearance and performance of packaging, the industry pursues higher environmental protection and barrier properties, and it is urgent to develop a super-high-brightness and high-barrier sheet for soft tubes, which is suitable for the cosmetics, pharmaceutical and food industries. SUMMARY

[0004] The purpose of the present application is to provide a super-high-brightness and high-barrier sheet for soft tubes and a forming process, which selects specific materials to prepare each layer of the sheet, and combines them according to an optimized forming process, so that the prepared sheet for soft tubes has super-high-brightness and high-barrier performance, and also has good mechanical properties and heat sealing performance.

[0005] A super-high-brightness and high-barrier sheet for soft tubes, which has the structure of an optical layer, a first adhesive layer, a functional layer, a core barrier layer, an intermediate functional layer, a second adhesive layer and a heat sealing layer in sequence.

[0006] Preferably, the thickness of the high-transparency optical layer is 55-65 µm.

[0007] Preferably, the first adhesive layer and the second adhesive layer are consistent, and the thicknesses of both are 15-25 µm.

[0008] Preferably, the thickness of the functional layer is 20-30 µm.

[0009] Preferably, the thickness of the core barrier layer is 10-15 pm.

[0010] Preferably, the thickness of the intermediate functional layer is 90-110 pm.

[0011] Preferably, the thickness of the heat-seal layer is 130-160 pm.

[0012] By adopting the seven-layer composite structure design of optical layer / adhesive layer / functional layer / core barrier layer / intermediate functional layer / adhesive layer / heat-seal layer, the prepared sheet has excellent water and oxygen barrier performance and ultrahigh interlayer peeling strength, and the structure has excellent mechanical properties and structural stability. This is because the structure constitutes a functional integrated system, the optical layer, the core barrier layer and the intermediate functional layer jointly construct the light penetration and reflection path, realizing ultrahigh brightness; the polarity and elasticity of the chlorinated polyethylene functional layer effectively buffer the internal stress caused by the difference in thermal expansion coefficient between the layers, preventing curling and delamination; two adhesive layers combine layers of different polarity; at the same time, the core barrier layer is placed in the middle of the structure, and is physically protected by the inner and outer layers, away from the heat-seal area to avoid thermal degradation, thereby avoiding mechanical damage, and cooperating with each layer to realize high barrier, high brightness and high light transmission.

[0013] The optical layer is a PE film, and its preparation method comprises the following steps: melting PE raw material in a casting machine, cooling roll cooling after extrusion, and obtaining.

[0014] Preferably, the melt index of the PE raw material at 190°C is 0.5-0.7 g / 10 min, and the density is 0.91-0.93 g / cm 3 .

[0015] In some preferred schemes, the PE raw material is linear low density polyethylene resin LF74580 from Westlake Corporation.

[0016] Preferably, the melting temperature is 200-240°C, the cooling roll temperature is 20-25°C, and the pulling speed is 80-100 m / min.

[0017] The preparation method of the first adhesive layer and the second adhesive layer comprises the following steps: mixing ethylene-acrylic ester copolymer and maleic anhydride grafted polyethylene, melt co-extrusion, and casting cooling to obtain.

[0018] Preferably, in the ethylene-acrylic ester copolymer, the content of methyl acrylate is 9%, and the elongation at break is ≥700%.

[0019] In some preferred schemes, the ethylene-acrylic ester copolymer is 1609 AC from DuPont Company, USA.

[0020] Preferably, the melt index of the maleic anhydride grafted polyethylene at 190℃ is 5.5-6.5g / 10min, and the maleic anhydride grafting rate is 1%-1.3%.

[0021] In some preferred embodiments, the maleic anhydride grafted polyethylene is from Dongguan Shenghao Plastic Raw Material Co., Ltd., PE-12L.

[0022] Preferably, the mass ratio of the ethylene-acrylic acid ester copolymer to the maleic anhydride grafted polyethylene is (2-3):1; further preferably, 7:3.

[0023] Preferably, the specific conditions of the melt co-extrusion are: the temperature of the extruder is 180-200℃, the temperature of the die head is 190℃, and the screw rotation speed is 45rpm.

[0024] Preferably, the specific conditions of the cast cooling are: the temperature of the cooling roller is 25℃, and the pulling speed is 15m / min.

[0025] By selecting ethylene-acrylic acid ester copolymer and maleic anhydride grafted polyethylene to prepare the adhesive layer, the interlayer peeling force can be improved, and the compatibility and stability of the sheet structure are also improved. This may be because the ester group in the ethylene-acrylic acid ester copolymer has good compatibility and physical adhesion with polar components such as chlorinated polyethylene, and the anhydride group of the maleic anhydride grafted polyethylene can chemically react with the hydroxyl group and ester group on the surface of VMPET and the molecular chain of polyethylene to form covalent bonds or strong hydrogen bonds. The combination of the two realizes the combination of rigidity and flexibility, the ethylene-acrylic acid ester copolymer provides toughness, the maleic anhydride grafted polyethylene provides strength, and the interfacial bonding force of different polar materials is improved. However, if the acidic carboxyl group of the ethylene-acrylic acid ester copolymer directly contacts the aluminum layer, it may corrode the aluminum layer and affect the brightness and other properties of the sheet.

[0026] The preparation method of the functional layer comprises the following steps: high-speed mixing chlorinated polyethylene resin with an auxiliary agent, then extruding with a double-screw extruder, and calendering to obtain the functional layer.

[0027] Preferably, the chlorine content of the chlorinated polyethylene resin is 34%-36%, and the elongation at break is ≥600%.

[0028] In some preferred embodiments, the chlorinated polyethylene resin is from Yaxing Chemical, WEIPREN® RESIN, 6100.

[0029] Preferably, the auxiliary agent comprises calcium stearate and epoxy soybean oil, and the mass ratio is 1:2, and the total addition amount is 1%-2% of the mass of the chlorinated polyethylene resin.

[0030] Preferably, the specific conditions of the high-speed mixing are: rotation speed of 800-1200 rpm, time of 8-12 min.

[0031] Preferably, the specific conditions of the double-screw extrusion are: temperature of 160-200 ℃, vacuum degree of 0.08-0.09 MPa, screw rotation speed of 60 rpm.

[0032] Preferably, the specific conditions of the calendering are: temperature of the three-roll calender of 150-160 ℃, roll gap of 0.25 mm.

[0033] By selecting a specific chlorinated polyethylene resin as the raw material for preparing the functional layer, direct contact of the aluminum layer with the adhesive layer can be avoided, thereby ensuring the performance of the sheet. This may be because, on the one hand, the chlorine atoms in the molecular chain of chlorinated polyethylene have strong polarity, which can form a dipole-dipole interaction with the carboxyl groups of the ethylene-acrylic acid ester copolymer of the adhesive layer, and at the same time, the non-polar polyethylene backbone of chlorinated polyethylene is compatible with the polyethylene segment of the maleic anhydride grafted polyethylene, so that the force of the carboxyl groups of the ethylene-acrylic acid ester is indirectly transmitted to the aluminum plating layer through the chlorinated polyethylene layer, forming a cross-layer network. On the other hand, there are micro defects and thin layers of aluminum oxide on the surface of the aluminum plating layer of the core barrier layer, and the polar groups of chlorinated polyethylene can fill the pores of the aluminum layer and form secondary bonding, making up for the deficiency that ethylene-acrylic acid ester cannot directly contact, at the same time, the rigid molecular chain of chlorinated polyethylene can also disperse the interlayer shrinkage stress, avoiding the interface peeling caused by the difference in thermal expansion coefficient when ethylene-acrylic acid ester directly contacts with the aluminum layer, and optimizing the adhesion performance of the sheet.

[0034] The preparation method of the core barrier layer comprises the following steps: A1, pretreatment of the PET base film; A2, vacuum aluminum plating.

[0035] Preferably, the thickness of the PET base film is 12 µm.

[0036] In some preferred embodiments, the PET base film is from Yuhua Toray Polyester Film Co., Ltd., PET12.

[0037] In the step A1, the pretreatment of the PET base film is corona treatment, and the surface wetting tension is treated to 48-52 dyn / cm.

[0038] In the step A2, the specific conditions of the vacuum aluminum plating are: the film plating method is evaporation, the vacuum degree is 2×10 -4 -1×10 -3 Pa, the evaporation temperature is 1100-1200 ℃, the deposition rate is 14-16 nm / s, and the aluminum layer thickness is 40-60 nm.

[0039] The PET base film of the core barrier layer is pretreated, and then high-precision aluminum evaporation is carried out by controlling the vacuum aluminum plating conditions, so that the water and oxygen barrier property and brightness of the sheet can be improved. This is because the high-vacuum environment almost eliminates the oxidation of aluminum vapor by oxygen molecules, ensuring the high purity and high reflectivity of the plated layer. At a specific evaporation temperature, the aluminum source maintains a stable vapor pressure, ensuring that aluminum atoms can uniformly nucleate, grow horizontally and finally form a continuous, dense and defect-free crystalline film on the surface of the PET base film. Such a microstructure simultaneously realizes high reflection of light and high barrier to gas molecules.

[0040] The preparation method of the intermediate functional layer comprises the following steps: mixing metallocene catalytic polyethylene, linear low-density polyethylene and nucleating agent in a 210-230℃ internal mixer for 10-20min, and then extruding and casting to obtain the intermediate functional layer.

[0041] Preferably, the metallocene catalytic polyethylene has a melt index of 1.0 g / 10min and a density of 0.918 g / cm 3 .

[0042] In some preferred embodiments, the metallocene catalytic polyethylene is from ExxonMobil, ExxonMobil Exceed 1018CA.

[0043] Preferably, the linear low-density polyethylene has a melt index of 2.5 g / 10min and a density of 0.921 g / cm 3 .

[0044] In some preferred embodiments, the linear low-density polyethylene is from Saudi sabic, 2102TN00W.

[0045] Preferably, the mass ratio of the metallocene catalytic polyethylene and the linear low-density polyethylene is (3-5):1; further preferably, 4:1.

[0046] Preferably, the nucleating agent is dibenzylidene sorbitol, and the addition amount is 0.2%-0.4% of the total mass of the metallocene catalytic polyethylene and the linear low-density polyethylene.

[0047] Preferably, the specific conditions of the extrusion casting are as follows: the temperature of the T-shaped die head is 210℃, and the temperature of the cooling roller is 30℃.

[0048] The intermediate functional layer is prepared by using metallocene-catalyzed polyethylene and linear low-density polyethylene in a specific ratio as raw materials, which can improve the mechanical properties and brightness of the sheet. This may be because the narrow molecular weight distribution of the metallocene-catalyzed polyethylene provides a rigid skeleton while the uniform chain structure reduces light scattering, and the long-chain branched structure of the linear low-density polyethylene improves the melt flowability while inhibiting the crystallization roughness, and the synergistic effect of the two can balance the toughness and processability while improving the optical performance. In addition, the addition of a proper amount of nucleating agent can serve as a heterogeneous nucleation point, greatly increasing the crystallization temperature and rate of the metallocene-catalyzed polyethylene, forming more and smaller spherulites, thereby significantly reducing the roughness of the film surface, improving the specular reflectivity of light, and further improving the brightness of the sheet.

[0049] The preparation method of the heat-sealing layer comprises the following steps: extrusion compounding an ionic polymer, low-density polyethylene and an antioxidant, and obtaining the heat-sealing layer.

[0050] Preferably, the ionic polymer is an ethylene-methacrylic acid-based ionic polymer, the melt index at 190℃ is 2-4g / 10min, and the IZOD notched impact strength at 23℃ is 19-20KJ / m.

[0051] In some preferred embodiments, the ionic polymer is Surlyn® resin 8940 from DuPont.

[0052] Preferably, the melt index of the low-density polyethylene at 190℃ is 1.7-2.3g / 10min, and the density is 0.9205-0.9245g / cm 3 .

[0053] In some preferred embodiments, the low-density polyethylene is LDPE / LD100AC from Yanshan Petrochemical.

[0054] Preferably, the antioxidant is antioxidant 1010, and the addition amount is 0.4%-0.6% of the total mass of the ionic polymer and the low-density polyethylene.

[0055] Preferably, the specific conditions of the extrusion compounding are: the temperature is 170-190℃, and the die lip gap is 0.15mm.

[0056] The forming process of the ultra-high brightness and high-barrier soft tube sheet comprises the following steps: S1, sequentially passing the optical layer, the first adhesive layer and the functional layer through a dry compounding machine for one-time dry compounding to obtain a semi-finished product 1; S2, performing two-time dry compounding of the semi-finished product 1 and the core barrier layer to obtain a semi-finished product 2; S3, performing maturation treatment on the semi-finished product 2 to obtain a semi-finished product 3; S4, compound the semi-finished product 3 with the intermediate functional layer by extrusion compounding process to obtain semi-finished product 4; S5, dry compounding the semi-finished product 4 with the second adhesive layer, the process parameters refer to step S1, to obtain semi-finished product 5; S6, compound the semi-finished product 5 with the heat-sealing layer by extrusion compounding process to obtain semi-finished product 6; S7, secondary curing treatment is carried out on the semi-finished product 6, and the sheet is obtained after slitting.

[0057] In step S1, the specific steps of the first dry compounding are as follows: after coating polyurethane adhesive in each layer, the sample is sent into the oven, the oven temperature is three-stage gradient, which is 60-70℃, 75-85℃ and 90-100℃ respectively, the total drying time is 45-90s, the compounding pressure is 0.3-0.8MPa, and the compounding speed is 50-100m / min.

[0058] Preferably, the polyurethane adhesive is from Han Gao, LIOFOL LA7705 / LA 6068, which can be used according to the instructions, and the coating amount is 2-5g / m 2 .

[0059] In step S2, the second dry compounding is the same as the first dry compounding, the difference is that the oven temperature is three-stage gradient, which is 50-60℃, 65-75℃ and 80-85℃ respectively, the total drying time is 45-90s, the compounding pressure is 0.3-0.8MPa, the compounding speed is 40-90m / min, and the polyurethane adhesive coating amount is 3-6g / m 2 .

[0060] In the dry compounding process step, three-stage gradient oven temperature control is selected, which can improve the flatness of the sheet and thus improve the performance of the sheet. This may be because the temperature gradient from low to high can make the solvent volatilize smoothly from the inside to the outside, avoiding the rapid volatilization of the surface solvent caused by high temperature, thus forming a hard shell to prevent the internal solvent from escaping, which will produce bubbles or odors during subsequent curing, affecting the compounding strength and effect, and thus affecting the performance of the sheet. By controlling the total temperature range of the first and second dry compounding, the aluminum plating layer of the core barrier layer can be protected. High temperature will cause the aluminum plating layer to oxidize, lose luster, or even fall off, which will seriously damage its appearance and barrier performance, and thus seriously affect the performance of the sheet.

[0061] In step S3, the specific conditions of the curing treatment are as follows: the curing temperature is 50-70℃, and the curing time is 24-48h.

[0062] The specific conditions of the extrusion process in the step S4 are: the extrusion temperature is 200-240 DEG C, the die temperature is 220-250 DEG C, the complex pressure is 0.5-1.0 MPa, and the cooling roller temperature is 15-30 DEG C.

[0063] The specific conditions of the extrusion process in the step S6 are: the extrusion temperature is 210-250 DEG C, the die temperature is 230-260 DEG C, the complex pressure is 0.6-1.2 MPa, and the cooling roller temperature is 10-25 DEG C.

[0064] The specific conditions of the secondary aging treatment in the step S7 are: the aging temperature is 60-80 DEG C, and the aging time is 48-72 h.

[0065] Compared with the prior art, the advantages and beneficial effects of the present application are: 1. The present application provides a kind of ultra-high brightness, high barrier property hose sheet material, by selecting specific material preparation sheet material each layer, and sequentially combined in order, then using optimized dry method combination and extrusion combination process combination, so that the final hose sheet material prepared, with ultra-high brightness and high barrier performance, while having good mechanical properties and heat sealing performance, suitable for cosmetics, pharmaceutical, food industry pipe packaging, has broad market application prospect.

[0066] 2. The present application is prepared by mixing ethylene-acrylic acid ester copolymer and maleic anhydride grafted polyethylene to prepare the adhesive layer, which can improve the interlayer peeling force, and improve the compatibility and stability of the sheet structure.

[0067] 3. The present application uses a specific chlorinated polyethylene resin as a raw material for preparing a functional layer, which can avoid direct contact between the aluminum layer and the adhesive layer, thereby ensuring the performance of the sheet.

[0068] 4. The present application can improve the water and oxygen barrier property and brightness of the sheet by pre-treating the PET base film of the core barrier layer and then controlling the vacuum aluminum plating conditions to perform high-precision aluminum evaporation.

[0069] 5. The intermediate functional layer of the present application is prepared using a specific ratio of metallocene-catalyzed polyethylene and linear low-density polyethylene as raw materials, which can improve the mechanical properties and brightness of the sheet.

[0070] 6. In the dry method combination process step of the present application, a three-stage gradient oven is used to control the temperature, which can improve the flatness of the sheet and thereby improve the performance of the sheet.

[0071] 7.The application adopts a seven-layer composite structure design of optical layer / adhesive layer / function layer / core barrier layer / intermediate functional layer / adhesive layer / heat-sealing layer, and the prepared sheet has excellent water and oxygen barrier performance and ultrahigh interlayer peeling strength, and the structure has excellent mechanical properties and structural stability. BRIEF DESCRIPTION OF DRAWINGS

[0072] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows.

[0073] Figure 1 A physical photo of the prepared sheet for the ultra-high brightness and high barrier soft tube according to the present application. DETAILED DESCRIPTION

[0074] The technical solutions in the embodiments of the present application will be described clearly and completely as follows. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0075] The raw materials in the present application are all commercially available, and are as follows: The PE raw material has a melt index of 0.5-0.7 g / 10 min at 190 ℃ and a density of 0.91-0.93 g / cm 3 , linear low-density polyethylene resin LF74580 from Westlake Corporation.

[0076] In the ethylene-acrylic ester copolymer, the content of methyl acrylate is 9%, and the elongation at break is ≥700%, 1609 AC from DuPont, USA.

[0077] The maleic anhydride grafted polyethylene has a melt index of 5.5-6.5 g / 10 min at 190 ℃, a maleic anhydride grafting rate of 1%-1.3%, and is PE-12L from Dongguan Shenghao Plastic Raw Material Co., Ltd.

[0078] The chlorinated polyethylene resin has a chlorine content of 34%-36% and an elongation at break of ≥600%, and is WEIPREN® RESIN, 6100 from Yaxing Chemical.

[0079] The PET base film has a thickness of 12 µm, and is PET12 from Yihua Toray Polyester Film Co., Ltd.

[0080] The metallocene-catalyzed polyethylene has a melt index of 1.0 g / 10 min at 190 ℃ and a density of 0.918 g / cm 3ExxonMobil Exceed 1018CA from ExxonMobil.

[0081] Linear low density polyethylene with melt index of 2.5 g / 10 min at 190℃ and density of 0.921 g / cm 3 2102TN00W from Saudi sabic.

[0082] Ionic polymer is ethylene-methacrylic acid based ionic polymer with melt index of 2-4 g / 10 min at 190℃ and IZOD notched impact strength of 19-20 KJ / m at 23℃, from DuPont, Surlyn® resin, 8940.

[0083] Low density polyethylene with melt index of 1.7-2.3 g / 10 min at 190℃ and density of 0.9205-0.9245 g / cm 3 LDPE / LD100AC from Yanshan Petrochemical.

[0084] Polyurethane adhesive from Henkel, LIOFOL LA7705 / LA 6068.

[0085] Example 1 The present example provides a sheet material for super high brightness, high barrier soft tube, which structure is in turn optical layer, first adhesive layer, functional layer, core barrier layer, intermediate functional layer, second adhesive layer, heat sealing layer.

[0086] The thickness of the high transparent optical layer is 60 µm.

[0087] The first adhesive layer and the second adhesive layer are consistent, and the thicknesses are both 20 µm.

[0088] The thickness of the functional layer is 25 µm.

[0089] The thickness of the core barrier layer is 12 µm.

[0090] The thickness of the intermediate functional layer is 100 µm.

[0091] The thickness of the heat sealing layer is 145 µm.

[0092] The optical layer is PE film, and the preparation method and steps are as follows: melt the PE raw material in a casting machine, cool the extruded product by a cooling roller, and obtain the product.

[0093] The melting temperature is 220℃, the cooling roller temperature is 23℃, and the traction speed is 90 m / min.

[0094] The preparation method of the first adhesive layer and the second adhesive layer comprises the following steps: mixing ethylene-acrylate copolymer and maleic anhydride grafted polyethylene, melt co-extrusion, and casting cooling to obtain the first adhesive layer and the second adhesive layer.

[0095] The mass ratio of the ethylene-acrylate copolymer and the maleic anhydride grafted polyethylene is 7:3.

[0096] The specific conditions of the melt co-extrusion are as follows: the temperature of the extruder is 190 DEG C, the temperature of the die head is 190 DEG C, and the screw rotation speed is 45 rpm.

[0097] The specific conditions of the casting cooling are as follows: the temperature of the cooling roller is 25 DEG C, and the traction speed is 15 m / min.

[0098] The preparation method of the functional layer comprises the following steps: high-speed mixing chlorinated polyethylene resin and an additive, double-screw extrusion, and calender molding to obtain the functional layer.

[0099] The additive is calcium stearate and epoxy soybean oil, and the mass ratio is 1:2, and the total additive amount is 1.5% of the mass of the chlorinated polyethylene resin.

[0100] The specific conditions of the high-speed mixing are as follows: the rotation speed is 1000 rpm, and the time is 10 min.

[0101] The specific conditions of the double-screw extrusion are as follows: the temperature is 180 DEG C, the vacuum degree is 0.085 MPa, and the screw rotation speed is 60 rpm.

[0102] The specific conditions of the calender molding are as follows: the temperature of the three-roller calender is 155 DEG C, and the roll gap is 0.25 mm.

[0103] The preparation method of the core barrier layer comprises the following steps: A1, PET base film pretreatment; A2, vacuum aluminum plating.

[0104] In the step A1, the PET base film pretreatment is corona treatment, and the surface wetting tension is 50 dyn / cm after the treatment.

[0105] In the step A2, the specific conditions of the vacuum aluminum plating are as follows: the film plating mode is evaporation, the vacuum degree is 6*10 -4 Pa, the evaporation temperature is 1150 DEG C, the deposition rate is 15 nm / s, and the aluminum layer thickness is 50 nm.

[0106] The preparation method of the intermediate functional layer comprises the following steps: mixing metallocene catalyzed polyethylene, linear low density polyethylene and nucleating agent in a 220 DEG C internal mixer for 15 min, and extruding and casting to obtain the intermediate functional layer.

[0107] The mass ratio of the metallocene catalyzed polyethylene and the linear low density polyethylene is 4:1.

[0108] The nucleating agent is dibenzyl sorbitol, and the amount added is 0.3% of the total mass of metallocene-catalyzed polyethylene and linear low-density polyethylene.

[0109] The specific conditions for the extrusion casting are: the temperature of the T-die is 210℃ and the temperature of the cooling roller is 30℃.

[0110] The method for preparing the heat-sealing layer includes the following steps: extruding and compounding an ionomer, low-density polyethylene, and an antioxidant to obtain the final product.

[0111] The antioxidant is antioxidant 1010, and the amount added is 0.5% of the total mass of the ionomer and low-density polyethylene.

[0112] The specific conditions for the extrusion compounding are: temperature of 180℃ and die lip gap of 0.15mm.

[0113] The molding process for the ultra-high brightness, high barrier flexible tube sheet includes the following steps: S1. The optical layer, the first adhesive layer, and the functional layer are sequentially dry-laminated in a dry laminating machine to obtain semi-finished product 1. S2. The semi-finished product 1 is combined with the core barrier layer in a secondary dry process to obtain the semi-finished product 2. S3. The semi-finished product 2 is subjected to a cooking process to obtain the semi-finished product 3; S4. The semi-finished product 3 and the intermediate functional layer are compounded by an extrusion compounding process to obtain the semi-finished product 4. S5. Dry lamination of semi-finished product 4 with the second adhesive layer, with process parameters referring to step S1, to obtain semi-finished product 5. S6. The semi-finished product 5 and the heat-sealing layer are compounded by an extrusion compounding process to obtain the semi-finished product 6; S7. The semi-finished product 6 is subjected to a second curing process, and then cut into sheets.

[0114] In step S1, the specific steps of the one-time dry lamination are as follows: after applying polyurethane adhesive between each layer, the product is sent into an oven with a three-stage temperature gradient of 65℃, 80℃, and 95℃, a total drying time of 70s, a lamination pressure of 0.5MPa, and a lamination speed of 75m / min.

[0115] The polyurethane adhesive coating amount is 3.5 g / m². 2 .

[0116] The step S2 is consistent with the primary dry lamination step, but the difference is that the oven temperature is a three-stage gradient, 55°C, 70°C, and 82°C, respectively, the total drying time is 70s, the lamination pressure is 0.5MPa, the lamination speed is 60m / min, and the polyurethane adhesive coating amount is 4.5g / m 2 .

[0117] In the step S3, the specific conditions of the curing treatment are as follows: the curing temperature is 60°C, and the curing time is 36h.

[0118] In the step S4, the specific conditions of the extrusion process are as follows: the extrusion temperature is 220°C, the die temperature is 235°C, the lamination pressure is 0.8MPa, and the cooling roller temperature is 20°C.

[0119] In the step S6, the specific conditions of the extrusion process are as follows: the extrusion temperature is 235°C, the die temperature is 245°C, the lamination pressure is 0.9MPa, and the cooling roller temperature is 15°C.

[0120] In the step S7, the specific conditions of the secondary curing treatment are as follows: the curing temperature is 70°C, and the curing time is 60h.

[0121] Example 2 The difference between this example and Example 1 is that the thickness of the high-transparency optical layer is 65µm.

[0122] The first adhesive layer and the second adhesive layer are consistent, and the thicknesses are both 15µm.

[0123] The thickness of the functional layer is 20µm.

[0124] The thickness of the core barrier layer is 12µm.

[0125] The thickness of the intermediate functional layer is 110µm.

[0126] The thickness of the heat-seal layer is 130µm.

[0127] Comparative Example 1 The difference between this comparative example and Example 1 is that the sheet for a super-high-brightness, high-barrier soft tube has the structure of an optical layer, a first adhesive layer, a core barrier layer, an intermediate functional layer, a second adhesive layer, and a heat-seal layer.

[0128] The thickness of the optical layer is 85µm.

[0129] Comparative Example 2 The difference between the present comparative example and Example 1 is that the preparation method of the first adhesive layer and the second adhesive layer is melt co-extrusion of maleic anhydride grafted polyethylene, and the first adhesive layer and the second adhesive layer are obtained after casting cooling.

[0130] Comparative Example 3 The difference between the present comparative example and Example 1 is that the preparation method of the first adhesive layer and the second adhesive layer is melt co-extrusion of maleic anhydride grafted polyethylene, and the first adhesive layer and the second adhesive layer are obtained after casting cooling.

[0131] Comparative Example 4 The difference between the present comparative example and Example 1 is that the melt index of the PE raw material at 190°C is 1.7-2.3 g / 10 min, and the density is 0.9205-0.9245 g / cm 3 , LDPE / LD100AC from Yanshan Petrochemical.

[0132] Comparative Example 5 The difference between the present comparative example and Example 1 is that the chlorine content of the chlorinated polyethylene resin is 30%, and the elongation at break is ≥600%.

[0133] The chlorinated polyethylene resin is WEIPREN® RESIN, 7030A from Yaxing Chemical.

[0134] Comparative Example 6 The difference between the present comparative example and Example 1 is that in step A2, the specific conditions of vacuum aluminum plating are as follows: the plating method is evaporation, the vacuum degree is 6×10 -4 Pa, the evaporation temperature is 1150°C, the deposition rate is 15 nm / s, and the aluminum layer thickness is 30 nm.

[0135] Comparative Example 7 The difference between the present comparative example and Example 1 is that in step A2, the specific conditions of vacuum aluminum plating are as follows: the plating method is evaporation, the vacuum degree is 6×10 -4 Pa, the evaporation temperature is 1150°C, the deposition rate is 8 nm / s, and the aluminum layer thickness is 50 nm.

[0136] Comparative Example 8 The difference between the present comparative example and Example 1 is that the mass ratio of the metallocene catalyzed polyethylene and the linear low density polyethylene is 2:1.

[0137] Comparative Example 9 The difference between the present comparative example and Example 1 is that in step S1, the specific steps of one-time dry lamination are as follows: after coating polyurethane adhesive in the middle of each layer, the coated layer is sent into an oven, the oven temperature is 80°C, the total drying time is 70 s, the lamination pressure is 0.5 MPa, and the lamination speed is 75 m / min.

[0138] Comparative Example 10 The difference between the present comparative example and Example 1 is that in the step S2, the secondary dry lamination is consistent with the primary dry lamination step.

[0139] Performance test The haze of the sheet is tested according to the method in GB / T 2410-2008; the 60° gloss of the sheet is tested according to the method in GB / T 8807-1988; the oxygen transmission rate of the sheet is tested according to the method in GB / T 19789-2005, cm 3 / (m 2 ·24h); the water vapor transmission rate of the sheet is tested according to the method in GB / T 1037-1988, g / (m 2 ·24h); the interlayer peeling force of the PE / CPE in the sheet is tested according to the method in GB / T 8808-1988, N / 15mm; the tensile strength and elongation at break of the sheet are tested according to the method in GB / T 1040.3-2006, the units are N / 15mm and respectively. The results are shown in Table 1.

[0140] Table 1 test results According to statistics, the sheet prepared in Examples 1-2 of the present application has low haze and high gloss, indicating that the brightness is super high, and the oxygen transmission rate and water vapor transmission rate are low, indicating that the barrier property is high, and the interlayer peeling force, tensile strength and elongation at break are high, indicating that the sheet has excellent mechanical properties. Comparative Example 1 does not add a functional layer; Comparative Example 2 does not use maleic anhydride grafted polyethylene in the preparation of the adhesive layer; Comparative Example 3 does not use maleic anhydride grafted polyethylene in the preparation of the adhesive layer; Comparative Example 4 uses ordinary low-density polyethylene as the PE raw material, and the transmission rate is low; Comparative Example 5 has a low chlorine content of the chlorinated polyethylene resin; Comparative Example 6 has a low aluminum layer thickness; Comparative Example 7 has a low deposition rate of vacuum aluminum plating; Comparative Example 8 has a high amount of linear low-density polyethylene; Comparative Example 9 does not use segmented drying in the primary dry lamination; and Comparative Example 10 has the same secondary dry lamination step as the primary dry lamination, and the drying temperature is high, and the prepared sheet has various defects and deficiencies in performance. Therefore, the sheet prepared by using the raw materials and method described in the present application has super high brightness and high barrier property, and has good mechanical properties and heat sealing performance, and is suitable for pipe packaging in the cosmetics, pharmaceutical, food and other industries, and has a broad market application prospect.

[0141] The above is a preferred embodiment of the present application, and it should be noted that for ordinary skilled persons in the technical field, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A sheet for ultra-high brightness, high barrier properties of flexible tubing, characterized in that, The structure is optical layer, first adhesive layer, functional layer, core barrier layer, intermediate functional layer, second adhesive layer and heat-sealing layer in sequence; the optical layer is a PE film, and its preparation method comprises the following steps: melting PE raw materials in a casting machine, cooling by a cooling roller after extrusion, and then obtaining the product; The PE raw material has a melt index of 0.5-0.7 g / 10 min and a density of 0.91-0.93 g / cm 3 .

2. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 1, characterized by The thickness of the high-transparency optical layer is 55-65µm; the first adhesive layer and the second adhesive layer are consistent, and the thicknesses of the first adhesive layer and the second adhesive layer are both 15-25µm; the thickness of the functional layer is 20-30µm; the thickness of the core barrier layer is 10-15µm; the thickness of the intermediate functional layer is 90-110µm; and the thickness of the heat-sealing layer is 130-160µm.

3. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 2, characterized by The preparation method of the first adhesive layer and the second adhesive layer comprises the following steps: mixing ethylene-acrylic acid ester copolymer and maleic anhydride grafted polyethylene, melt co-extrusion, and then obtaining the product after casting and cooling.

4. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 2, characterized by The preparation method of the functional layer comprises the following steps: high-speed mixing chlorinated polyethylene resin and an additive, double-screw extrusion, and calender molding.

5. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 2, characterized by The preparation method of the core barrier layer comprises the following steps: A1, PET base film pretreatment; A2, vacuum aluminum plating.

6. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 5, characterized by In the step A1, the PET base film pretreatment is corona treatment, and the surface wetting tension is 48-52dyn / cm after the treatment.

7. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 6, characterized by The specific conditions of vacuum aluminizing in step A2 are as follows: the plating mode is evaporation, the vacuum degree is 2x10 -4 -1x10 -3 Pa, the evaporation temperature is 1100-1200℃, the deposition rate is 14-16nm / s, and the thickness of the aluminum layer is 40-60nm.

8. The sheet for ultra-high brightness, high-barrier flexible tube according to claim 2, characterized by The preparation method of the intermediate functional layer comprises the following steps: mixing metallocene-catalyzed polyethylene and linear low-density polyethylene with a nucleating agent in a 210-230℃ internal mixer for 10-20min, and then obtaining the product after extrusion casting.

9. A forming process of the sheet for ultra-high brightness, high-barrier flexible tube according to any one of claims 1 to 8, characterized by, The method comprises the following steps: S1, sequentially passing the optical layer, the first adhesive layer and the functional layer through a dry compound machine for one-time dry compounding to obtain a semi-finished product 1; S2, performing two-time dry compounding of the semi-finished product 1 and the core barrier layer to obtain a semi-finished product 2; S3, performing aging treatment on the semi-finished product 2 to obtain a semi-finished product 3; S4, compounding the semi-finished product 3 and the intermediate functional layer by an extrusion compounding process to obtain a semi-finished product 4; S5, performing dry compounding of the semi-finished product 4 and the second adhesive layer, and the process parameters are referred to the step S1 to obtain a semi-finished product 5; S6, compounding the semi-finished product 5 and the heat-sealing layer by an extrusion compounding process to obtain a semi-finished product 6; S7, performing two-time aging treatment on the semi-finished product 6, and then cutting to obtain a sheet.

10. The process for forming a sheet for ultra-high brightness, high-barrier flexible hose according to claim 9, characterized in that, In the step S1, the specific steps of one-time dry compounding are as follows: after coating polyurethane adhesive in each layer, the product is sent into an oven, the oven temperature is three-stage gradient, and the temperatures of the three stages are 60-70℃, 75-85℃ and 90-100℃ respectively, the total drying time is 45-90s, the compounding pressure is 0.3-0.8MPa, and the compounding speed is 50-100m / min.

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