Squeezable high barrier polyolefin tube

Abstract

A plastic tube is provided that has improved oxygen and / or moisture barrier properties, increased mechanical strength, and improved resistance to environmental factors such as repeated squeezing and / or twisting. [Solution] The plastic tube has a main body (A) and a shoulder portion (B), wherein the main body (A) is a plastic film laminate having a total thickness of 200 to 500 μm, and includes a multilayer film (A1) having an EVOH layer (a1) metallized or coated with an inorganic oxide on one side, a polyolefin layer (a2), and an adhesive layer (a3) ​​between the surface of the EVOH layer (a1) that is neither metallized nor coated with an inorganic oxide and the polyolefin layer (a2), and a polyolefin film (A2) laminated on the metallized or inorganic oxide coated surface of the EVOH layer (a1).

Description

[Technical field]

[0001] The present invention relates to plastic tubing comprising metallized or inorganic oxide coated EVOH that has high barrier properties to both moisture and oxygen. [Background technology]

[0002] Squeezable tubes can be used for a variety of packaging applications in the pharmaceutical, cosmetic and food industries. They typically contain viscous liquids such as toothpaste, sauces or ointments. Essentially, a tube is a cylindrical hollow member consisting of a tube body and a shoulder. Historically, such tubes have been made of metal, and even today many tubes contain a fairly thick layer of aluminum to provide good barrier properties.

[0003] However, the industry is striving to replace energy-intensive aluminum with recyclable polymers as much as possible. Ethylene-vinyl alcohol (EVOH) is known as an excellent barrier material against various gases, including oxygen. Thus, multilayer structures including layers containing EVOH, such as laminates including layers of polyethylene / EVOH / polyethylene, have already been reported as barrier materials for plastic tubes (e.g., Patent Document 1). However, their moisture barrier properties are insufficient for certain applications.

[0004] Patent Document 2 describes a resin composition containing an ethylene-vinyl alcohol copolymer and an unsaturated aldehyde, the content of which is 0.01 ppm or more and 100 ppm or less. The preferred unsaturated aldehydes used therein are crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal. By containing such an unsaturated aldehyde in the resin composition, the occurrence of defects such as fish eyes and streaks can be suppressed, and a melt-molded product with excellent appearance can be obtained. However, there is no description about a squeezable tube. Furthermore, there is no description about the oxygen transmission rate (OTR) of the resin composition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2014-97629 [Patent Document 2] WO 2013 / 146961 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] To solve the above problems, the object of the present invention is to provide a plastic tube having improved oxygen and / or moisture barrier properties, improved cost, improved mechanical strength, and improved resistance to environmental factors such as repeated squeezing and / or twisting. [Means for solving the problem]

[0007] Surprisingly, the inventors have found that a combination of metallized or inorganic oxide coated EVOH sandwiched between polyolefin films can be used in place of a tube containing aluminum foil to provide a plastic tube with improved properties. Based on these surprising discoveries, these and other problems have been solved by the present invention.

[0008] In a first aspect, the present invention provides a plastic tube having a body (A) and a shoulder (B), a. The main body (A) is a plastic film laminate having a total thickness of 200 to 500 μm, i. 1. An EVOH layer (a1) which is metallized or coated with an inorganic oxide on one side; 2. A polyolefin layer (a2), and 3. An adhesive layer (a3) ​​between the non-metallized and non-inorganic oxide coated surface of the EVOH layer (a1) and the polyolefin layer (a2). A multilayer film (A1), ii. A polyolefin film (A2) laminated onto the metallized or inorganic oxide coated surface of the EVOH layer (a1) Including, b. the ethylene content of the EVOH in the EVOH layer (a1) is 20 to 50 mol %, c. the thickness of the EVOH layer (a1) is 5 μm or less; d. The oxygen permeability of the body (A) measured at 23°C and 50% RH in accordance with ISO21309-2 Appendix C is 0.5cc / m 2 ·day·atm or less, relating to plastic tubing.

[0009] In the above plastic tube, the multilayer film (A1) is preferably uniaxially stretched at a stretch ratio of 3 or more. Also, the multilayer film (A1) is preferably biaxially stretched in both the machine direction and the width direction at a stretch ratio of 3 or more. Also, the melting point of the EVOH layer (a1) is preferably 150° C. or less.

[0010] In the above plastic tube, the EVOH layer (a1) preferably contains crotonaldehyde (X1) and 2,4-hexadienal (X2), the content x1 of crotonaldehyde (X1) in the EVOH layer (a1) is 0.01 ppm or more and 4.0 ppm or less, and the content x2 of 2,4-hexadienal (X2) in the EVOH layer (a1) is 0.005 ppm or more and 0.65 ppm or less.

[0011] More preferably, the EVOH layer (a1) optionally contains 2,4,6-octatrienal (X3), the sum (x1+x2+x3) being 7.0 ppm or less, (x1) being the amount (ppm) of crotonaldehyde (X1) in the EVOH layer (a1), (x2) being the amount (ppm) of 2,4-hexadienal (X2) in the EVOH layer (a1), and (x3) being the amount (ppm) of 2,4,6-octatrienal (X3) in the EVOH layer (a1).

[0012] It is more preferable that x1 / (x2+x3) is 2.0 or more and 150.0 or less. It is more preferable that the sum (x2+2x3) of the content x2 (ppm) of 2,4-hexadienal (X2) and twice the content x3 (ppm) of 2,4,6-octatrienal (X3) is 0.65 ppm or less.

[0013] In the plastic tube, the main body (A) preferably comprises a polyolefin layer (a5) comprising post-consumer recycled polyolefin sandwiched between the polyolefin layer (a2) and the additional EVOH layer (a4). The multilayer structure (A1) is preferably produced by co-extrusion of the separate layers (a1)-(a3) and the optional layers (a4) and (a5). The shoulder portion (B) is preferably a multilayer structure comprising an EVOH layer (b1) sandwiched between two polyolefin layers (b2) and (b3). The shoulder portion (B) is preferably a multilayer structure having adhesive layers between the EVOH layer (b1) and the polyolefin layer (b2) and between the EVOH layer (b1) and the polyolefin layer (b3).

[0014] A preferred embodiment is the use of said plastic tubes in food, cosmetic or pharmaceutical packaging applications. Effect of the Invention

[0015] The plastic tubing of the present invention provides improved oxygen and / or moisture barrier properties, improved cost, improved mechanical strength, and improved resistance to environmental factors such as repeated squeezing and / or twisting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] EVOH, as used herein, comprises ethylene and vinyl alcohol units as the main structural units, and may also comprise one or more other structural units in addition to ethylene and vinyl alcohol units.

[0017] EVOH is usually obtained by copolymerizing ethylene and vinyl acetate, followed by a saponification process of the resulting ethylene-vinyl acetate copolymer.

[0018] The lower limit of the content of ethylene units, i.e., the ratio of the number of ethylene units to the total number of monomer units in EVOH, is preferably 3 mol%, more preferably 10 mol%, and even more preferably 20 mol%. On the other hand, the upper limit of the content of ethylene units is preferably 70 mol%, more preferably 60 mol%, even more preferably 55 mol%, and particularly preferably 50 mol%. Also preferably, the ethylene content is 20 to 50 mol%.

[0019] Preferably, the lower limit of the degree of saponification of EVOH, i.e., the ratio of the number of vinyl alcohol units to the total number of vinyl alcohol units and vinyl acetate units in EVOH, is 80 mol%, more preferably 95 mol%, and particularly preferably 99 mol%.

[0020] The EVOH layer preferably contains compounds such as acids and / or metal ions to improve thermal stability and adjust viscosity. Examples of suitable compounds include alkali metal salts, carboxylic acids, phosphoric acid compounds, and boron compounds. These compounds can be used as premixes with the EVOH.

[0021] Suitable alkali metal salts include sodium acetate, potassium acetate, sodium phosphate, lithium phosphate, sodium stearate, potassium stearate, sodium ethylenediaminetetraacetate, etc. Carboxylic acids include oxalic acid, succinic acid, benzoic acid, citric acid, acetic acid, lactic acid, etc. Phosphoric acid compounds include various acids such as phosphoric acid and phosphorous acid, and their salts. Boron compounds include boric acid, borate esters, borates, and borohydrides.

[0022] The EVOH layer may contain other additives such as heat stabilizers, UV absorbers, antioxidants, plasticizers, antistatic agents, lubricants, colorants, and fillers, within the scope of the present invention. When the EVOH layer contains such additives, the amount thereof is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total mass of the EVOH layer.

[0023] Suitable antioxidants for use herein are substances that inhibit the oxidative degradation or crosslinking of EVOH, such as 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis-(6-t-butylphenol), 2,2'-methylenebis-(4-methyl-6-t-butylphenol), octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, 4,4'-thiobis-(6-t-butylphenol), tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 3,3'-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide, and the like.

[0024] Suitable plasticizers include diethyl phthalate, dibutyl phthalate, dioctyl phthalate, waxes, liquid paraffin, phosphate esters, and the like.

[0025] Suitable UV absorbers include ethylene-2-cyano-3,3'-diphenylacrylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and the like.

[0026] Suitable antistatic agents include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, and the like.

[0027] Suitable lubricants include ethylene bis(stearamide), butyl stearate, and the like.

[0028] The thickness of the EVOH layer of the present invention is 5 μm or less, preferably 3 μm or less, more preferably 2 μm or less. Even if the thickness of the EVOH layer is very small, the oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the tube body are low. This is because the surface of the EVOH layer is metallized or coated with an inorganic oxide. If the thickness of the EVOH layer is very small, the mass ratio of EVOH in the tube body becomes very small. Then, the tube body can be recycled and used together with polyolefin. By making the EVOH layer thin, not only the barrier property but also the recyclability is improved. The thickness of the EVOH layer is preferably 0.5 μm or more.

[0029] "Thickness" as used herein shall refer to the average thickness of the individual layers after manufacture of the multi-layer structure.

[0030] The EVOH layer (a1) is metallized or coated with an inorganic oxide on at least one side.

[0031] When light shielding is required, a metal coating is preferred. When the surface is metallized, aluminum metallization is most preferred. The content of metal atoms in the metal coating is preferably 50 mol % or more, more preferably 70 mol % or more, even more preferably 90 mol % or more, and particularly preferably 95 mol % or more.

[0032] Inorganic oxide coatings are usually preferred when the contents of the plastic tube need to be visible. Suitable inorganic oxide coatings include coatings containing oxides of silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, yttrium, and mixtures thereof. Preferably, they include vapor-deposited films of alumina or silica / aluminum oxide, magnesium oxide, silicon oxide, or mixtures thereof. Metal oxynitrides are also suitable.

[0033] EVOH films have good compatibility with metallization and inorganic oxide coatings, allowing the film to maintain its barrier properties even when subjected to physical stresses such as twisting and squeezing.

[0034] The metallization or inorganic oxide coating can be deposited by known physical or chemical vapor deposition methods. Specifically, vacuum deposition, sputtering, ion plating, ion beam mixing, plasma CVD, laser CVD, MO-CVD, and thermal CVD. Preferably, physical vapor deposition is used. Before deposition, the EVOH surface may be plasma treated. The plasma treatment may be a known method, but atmospheric pressure plasma treatment is preferred. In atmospheric pressure plasma treatment, nitrogen, helium, neon, argon, krypton, xenon, radon, etc. are used as discharge gas. Among these, nitrogen, helium, and argon are preferably used, and nitrogen is particularly preferred because it can reduce costs.

[0035] The thickness of the metal or inorganic oxide layer is preferably less than 150 nm, more preferably less than 100 nm, even more preferably less than 50 nm, and most preferably less than 25 nm. The thickness of the metal or inorganic oxide layer is preferably greater than 1 nm, more preferably greater than 5 nm.

[0036] The total thickness of the main body (A) is from 200 to 500 μm, preferably from 225 to 450 μm, and more preferably from 250 to 400 μm.

[0037] In a preferred embodiment, the multilayer film (A1) is uniaxially stretched at a stretch ratio of 3 or more. Also preferably, the stretch ratio is less than 12. More preferably, the multilayer film (A1) is stretched more than 4 times, more preferably more than 5 times. Also preferably, the multilayer film (A1) is stretched in the machine direction.

[0038] In another preferred embodiment, the multilayer film (A1) is biaxially stretched in both the machine direction and the width direction at a stretch ratio of 3 or more. The biaxial stretching may be either sequential biaxial stretching or simultaneous biaxial stretching. The lower limit of the areal stretch ratio is more preferably 6 times, and most preferably 8 times. The upper limit of the areal stretch ratio is more preferably 50 times, and more preferably 45 times. When the areal stretch ratio is within the above range, the thickness uniformity, gas barrier properties, and mechanical strength of the monolayer film are improved. Furthermore, the stretching temperature can be, for example, 80°C or more and 170°C or less.

[0039] The stretching method is not particularly limited, and for example, a tender stretching method, a tubular stretching method, a roll stretching method, etc., can be used. From the viewpoint of production cost, uniaxial stretching by the roll stretching method is preferred.

[0040] Also preferably, in the case of sequential biaxial stretching of polyethylene and EVOH-based multilayer films, the melting point of the EVOH layer (a1) is 150°C or lower, more preferably 140°C or lower, and most preferably 130°C or lower.

[0041] The lower limit of the content x1 of crotonaldehyde (X1) in the EVOH layer (a1) is preferably 0.01 ppm, more preferably 0.10 ppm, even more preferably 0.20 ppm, and even more preferably 0.40 ppm, while the upper limit is preferably 4.0 ppm, more preferably 3.5 ppm, even more preferably 2.7 ppm, and particularly preferably 1.5 ppm.

[0042] Furthermore, the lower limit of the content x2 of 2,4-hexadienal (X2) in the EVOH layer (a1) is preferably 0.005 ppm, more preferably 0.01 ppm, and even more preferably 0.02 ppm, while the upper limit is preferably 0.65 ppm, more preferably 0.20 ppm, even more preferably 0.10 ppm, even more preferably 0.08 ppm, and particularly preferably 0.06 ppm.

[0043] In the present invention, it is preferable that the content x1 of crotonaldehyde (X1) and the content x2 of 2,4-hexadienal (X2) in the EVOH layer (a1) are within the above ranges. In this way, even when the tube body is folded, the OTR value and WVTR value of the tube body are small. By adding crotonaldehyde (X1) and 2,4-hexadienal (X2) to the EVOH resin, the die build-up during melt molding of a film containing an EVOH layer is reduced. Therefore, it is believed that a metallized or inorganic oxide coating layer can be stably attached to the EVOH surface.

[0044] The upper limit of the content x3 of 2,4,6-octatrienal (X3) in the EVOH layer (a1) is preferably 0.325 ppm, more preferably 0.23 ppm, further preferably 0.07 ppm, and particularly preferably 0.04 ppm. The lower limit of the content x3 is 0 ppm, more preferably 0.005 ppm.

[0045] The EVOH layer (a1) may optionally contain 2,4,6-octatrienal (X3). Preferably, the upper limit of the sum (x1+x2+x3) is 7.0 ppm, more preferably 4.0 ppm, and especially 1.0 ppm. If the sum (x1+x2+x3) exceeds 7.0 ppm, the OTR value and WVTR value increase, and odor occurs. The lower limit of x1+x2+x3 is preferably 0.01 ppm, more preferably 0.10 ppm, and most preferably 0.50 ppm.

[0046] The lower limit of x1 / (x2+x3) is preferably 4.0, more preferably 8.0. On the other hand, the upper limit of x1 / (x2+x3) is preferably 60.0, more preferably 25.0, and most preferably 13.0. If the value of x1 / (x2+x3) is less than the lower limit, the thickness unevenness of the EVOH layer (a1) in the multilayer structure of the tube body tends to increase. As a result, the OTR of the tube body before and after the bending test tends to increase, and the odor evaluation tends to deteriorate. These effects are not observed when only one of the compounds X1, X2, or X3 is used.

[0047] The upper limit (ppm) of the sum (x2+2x3) of the content x2 (ppm) of 2,4-hexadienal (X2) and the content x3 (ppm) of 2,4,6-octatrienal (X3) is 0.65 ppm or less, preferably 0.50 ppm, more preferably 0.30 ppm, and most preferably 0.10 ppm. If the sum (x2+2x3) is too large, the appearance of the tube tends to deteriorate.

[0048] Also preferably, the EVOH layer (a1) in the multilayer film (A1) contains crotonaldehyde (X1) and either 2,4-hexadienal (X2) or 2,4,6-octatrienal (X3) and satisfies the following formulas (1) and (2). (1):2.0≦(x1) / ((x2)+(x3))<150.0 (2): (x2) + 2 × (x3) ≦ 0.65 In the above formulas (1) and (2), (x1) is the amount (ppm) of crotonaldehyde (X1) in the EVOH layer (a1), (x2) is the amount (ppm) of 2,4-hexadienal (X2) in the EVOH layer (a1), and (x3) is the amount (ppm) of 2,4,6-octatrienal (B3) in the EVOH layer (a1). If formula (1) or formula (2) is not satisfied, the OTR of the tube body before and after the bending test tends to increase, the odor evaluation tends to deteriorate, and the appearance of the tube tends to deteriorate.

[0049] Adhesive layer (a3) ​​is known in the art and may incorporate any polar functional group to promote compatibility with polar materials and any non-polar functional group to maintain compatibility with non-polar layers. Examples of materials useful for such adhesive layers include anhydride modified polyolefins, such as maleic anhydride grafted polypropylenes and polyethylenes, such as Bynel® 40E529 available from DuPont, and ethylene polar terpolymers, such as LOTADER™ available from Arkema.

[0050] Preferably, the thickness of the adhesive layer is 20 μm or less, more preferably 10 μm or less, while the thickness is preferably 1 μm or more, and also preferably the thickness of the adhesive layer is 1 μm to 10 μm.

[0051] The polyolefin layers according to the present invention may be independently selected from layers comprising polyethylene (PE), in particular high density polyethylene (HDPE) or low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and polypropylene (PP).

[0052] It is also preferred to use at least some recycled polyolefin in the body (A) to address environmental concerns and to avoid taxes, for example, some European countries impose taxes on packaging materials that contain less than 30% recycled material.

[0053] However, when recycled polyolefin resin is used for general tubes, there are concerns about safety issues due to migration of contaminants and / or odor problems from the recycled materials. It has now been found that the main body (A) of the present invention can solve these problems and block migration of contaminants and unpleasant odors.

[0054] Therefore, another preferred embodiment relates to a body (A) comprising a polyolefin layer (a5) between the polyolefin layer (a2) and the additional EVOH layer (a4) which comprises a post-consumer recycled polyolefin or a post-industrial recycled polyolefin.

[0055] The method for producing the main body (A) or the multilayer film (A1) of the present invention is not particularly limited as long as it is a method that can satisfactorily laminate and bond each layer, and any of the known methods such as coextrusion, pasting, coating, lamination and bonding can be used.

[0056] Preferably, the multilayer structure (A1) is produced by laminating a co-extruded film containing (a1) to (a3) ​​and a co-extruded film containing (a4) and (a5).

[0057] Alternatively, the multilayer structure (A1) is produced by laminating a coextruded film containing (a1) to (a3), a film containing (a4), and a film containing (a5).

[0058] Yet another aspect of the present invention relates to the use of the plastic tube according to the present invention in food, cosmetic or pharmaceutical packaging applications. EXAMPLES

[0059] Example 1 Manufacturing of EVOH1 A fully saponified ethylene-vinyl alcohol copolymer with an ethylene content of 32 mol% (melt index: 1.6 g / 10 min (190 °C, load: 2.16 kg), density: 1.19 g / cm) commercially available from EVAL Europe NV. 32 kg of EVOH, 0.8 kg of water and 2.2 kg of MeOH are placed in a 60 liter tank equipped with a jacket, stirrer and reflux condenser. The mixture is stirred at 60° C. for 5 hours to completely dissolve. Crotonaldehyde is added to the resulting solution. The amount of crotonaldehyde is adjusted as described in Table 5. The solution is passed through a nozzle with a diameter of 4 mm and coagulated in a water / MeOH=90 / 10 mixture at −5° C. to produce strands. The strands are cut into pellets using a strand cutter to obtain unwashed hydrous EVOH pellets. The resulting EVOH pellets are placed in ion-exchanged water (bath ratio 20), stirred for 2 hours, and the water is removed to wash the EVOH pellets. The process is repeated three times to obtain washed EVOH pellets. The moisture content of the resulting EVOH pellets is 52% by weight as measured by a Mettler halogen moisture analyzer HR73.

[0060] The obtained pellets are immersed in an aqueous solution containing sodium acetate at a concentration of 0.510 g / L, acetic acid at a concentration of 0.8 g / L, and phosphoric acid at a concentration of 0.04 g / L (bath ratio 20) for 4 hours with regular stirring. The pellets are then dehydrated and dried under nitrogen with an oxygen concentration of less than 1 volume percent at 80°C for 3 hours and at 105°C for 16 hours. As a result, dried EVOH pellets (EVOH1 pellets) containing acetic acid, phosphoric acid, sodium ions (sodium salt), and crotonaldehyde are produced. They are cylindrical pellets with an average diameter of 2.8 mm and an average height of 3.2 mm. The composition of the dried pellets is evaluated. The sodium ion content in the dried resin composition pellets was 100 ppm, the phosphoric acid content was 40 ppm, and the acetic acid content was 200 ppm. The contents of crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal in the EVOH1 pellets are shown in Table 5. The method for measuring the content of these aldehydes is described below.

[0061] Determination of Crotonaldehyde, 2,4-Hexadienal, and 2,4,6-Octatrienal in EVOH1 Pellets: One dried EVOH pellet is pulverized by freeze-pulverization, and 50.0 mg is weighed into a glass tube for a thermal desorption gas chromatograph mass spectrometer to prepare a sample tube. Using the thermal desorption gas chromatograph mass spectrometer described below, the sample is heated under the following conditions, the total amount of volatile gas from the sample is adsorbed into the adsorption tube, and the re-emitted gas is separated from the adsorption tube by a column. The peaks of each component are detected. A calibration curve is created from the peak areas of the standard samples of crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal, and each is quantified by the absolute calibration curve method. When measuring the standard material, a suction tube (Tenax (registered trademark) / Carboxen (registered trademark)) is impregnated with the standard sample, and the suction tube impregnated with the standard sample is used instead of the sample tube. The temperature at the time of discharge after adsorption is measured by the same method as in the case of the measurement of the sample tube, except that the temperature of the sample tube is changed from 170 ° C to the temperature of the adsorption tube at 260 ° C.

[0062] (Thermal desorption part) Equipment: TurboMatrix-ATD (PerkinElmer Japan) Temperatures when adsorbing the sample into the adsorption tube: 170°C (sample tube), -30°C (adsorption tube), 250°C (valve), 260°C (transfer line) Adsorption time in the adsorption tube: 10 minutes Temperature at the time of release after sample adsorption: 170°C (sample tube), 260°C (adsorption tube), 250°C (valve), 260°C (transfer line) Suction tube discharge time: 35 minutes Carrier gas: Helium Carrier gas flow rate to column: 1.0 mL / min Pressure: 120kPa (gas chromatograph mass spectrometer) Equipment: 7890B GC system, 7977B MSD (Agilent Technologies) Column: DB-WAX UI (length: 30 m, inner diameter: 0.25 mm, film thickness: 0.50 μm) Column oven temperature: After holding at 40°C for 5 minutes, adjust the temperature to 240°C at a heating rate of 10°C / min and hold for 10 minutes (total measurement temperature 35 minutes) Transfer line (connection) temperature: 240℃ Ionization conditions: EI+ Detected ion mass range: m / z = 29-600 Detection method: SCAN (standard sample) Crotonaldehyde: Aldrich 2,4-Hexadienal: Aldrich 2,4,6-Octatrinal: Manufactured by NARD Laboratories

[0063] A three layer barrier film is produced on a Collin cast coextrusion line using the following thicknesses of PE, adhesive resin (Adh), and EVOH: PE1 / Adh1 / EVOH1=19 / 3 / 3μm PE1: Lumicene® Suertough 40ST05 available from Total, melt index 0.5 g / 10 min (190° C., 2.16 kg load) Adh1: Maleic anhydride modified polyethylene Admer® NF528 available from Mitsui Chemicals, Inc., melt index 2.5 g / 10 min (190° C., load 2.16 kg) The EVOH surface of the above three-layer film is metallized with aluminum, and the optical density is 3.0.

[0064] Three-layer PE films were produced on a Collin cast coextrusion line using the following PE resins and with thicknesses as follows: PE2 / PE3 / PE2=30 / 60 / 30μm PE2: commercially available from Dow Chemical, density 0.926g / cm 3 Dowlex209 PE3: Commercially available from Prime Polymer, density 0.950 g / cm 3 Hizex 3300F

[0065] A polyurethane adhesive (Takelac A-520 and Takenate A-50, 2 μm thick after drying) is applied to both sides of the metallized three-layer barrier film to laminate the three-layer PE film.

[0066] This laminated film is made into a cylindrical shape by heat sealing to form a tube body with a diameter of 50 mm and a length of 158 mm, and is combined with a tube shoulder part made by a normal compression molding method using PE4. PE4: Purell ACP 6541A commercially available from Lyondell Basell, melt index 1.45 g / 10 min (190 °C, load 2.16 kg), density: 0.954 g / cm 3 The average thickness of the tube shoulder part is 1.1 mm, and the surface area of the shoulder part is 19 cm 2 is. In the final stage, the bottom of the tube is heat sealed.

[0067] Oxygen permeability measurement: Measure the oxygen transmission rate of only the tube body and the tube according to Annex C of ISO 21309-2 at 23 °C and 50% RH, respectively.

[0068] Water vapor transmission rate test: Measure the water vapor transmission rate of the tube according to ASTM F1249 at 38 °C and 90% RH.

[0069] Tube folding test: Cut the tube body part and the shoulder part with a cutter, and cut out the body part into a flat sheet (10 cm × 10 cm). Bend the flat sheet 180° in both the vertical and horizontal directions by hand, and then measure the oxygen transmission rate.

[0070] Odor Rating: Put the tube into a glass container and seal it with a metal cap. After storing at 40 °C for 7 days, panelists detect the odor in the glass container. Evaluation: (low odor) A < B (strong odor)

[0071] Tube body appearance: Visually evaluate the appearance of the tube body. Evaluation: (good) A < B < C (bad); A: No visible defects in the tube body to the naked eye B: There is a slight line on the tube body C: There is a clearly visible line on the tube body

[0072] The test results and layer thicknesses of Examples 2 to 7 and Reference Examples 1 and 2 are summarized in Tables 1 and 2.

[0073] Example 2 A three layer barrier film was produced on a Collin cast coextrusion line of PE, adhesive resin (Adh), and EVOH with the following thicknesses: PE1 / Adh1 / EVOH1=95 / 15 / 15μm The three-layer barrier film is then uniaxially stretched (machine direction) at 120° C. with a stretch ratio of 5. After stretching, the thickness is PE1 / Adh1 / EVOH1=19 / 3 / 3 μm.

[0074] The same procedure as described in Example 1 is repeated, except for the preparation of the three-layer barrier film.

[0075] Example 3 A three layer barrier film was produced on a Collin cast coextrusion line of PE, adhesive resin (Adh), and EVOH with the following thicknesses: PE5 / Adh1 / EVOH2=352 / 32 / 16μm PE5: Innate™ TF80 available from Dow Chemical, melting point 122° C. EVOH2: Epoxypropane modified EVOH with 44 moles of ethylene content, produced by the following process: 28 parts by weight of zinc acetylacetonate monohydrate is mixed with 957 parts by weight of 1,2-dimethoxyethane to obtain a mixed solution. 15 parts by weight of trifluoromethanesulfonic acid is added to the obtained mixed solution while stirring to obtain a catalyst solution. Next, EVOH with an ethylene unit content of 44.0 mol% and a saponification degree of 99.9 mol% or more is used in a Toshiba Machine Co., Ltd. TEM-35BS extruder (37 mmφ, L / D=52.5), barrel C1 is water-cooled, barrels C2 to C3 are operated at 200°C, barrels C4 to C15 are operated at 240°C, and the screw speed is 250 rpm. Epoxypropane (1.5 kg / h) and the above catalyst solution are added from the inlet 1 of C8. Next, an aqueous solution of sodium acetate and potassium acetate is added from the inlet 2 of C13. The discharged strand is cooled and solidified in a cooling bath, and then cut to obtain pellets. At this stage, the amount of catalyst solution added is adjusted so that the melting point of the modified EVOH becomes 119°C.

[0076] The three-layer barrier film is then biaxially stretched at 125°C by a tenter frame sequential stretching method, with the stretch ratios being 4 in the machine direction and 4 in the cross direction, respectively. After stretching, the thickness is PE1 / Adh1 / EVOH2=22 / 2 / 1μm. The same procedure as described in Example 1 is repeated, except for the preparation of the three-layer barrier film.

[0077] Example 4 EVOH3 Production The ethylene vinyl alcohol copolymer was a fully saponified copolymer with an ethylene content of 48 mol % commercially available from EVAL Europe NV, melt index: 6.4 g / 10 min (190° C., load: 2.16 kg), density: 1.12 g / cm 3 EVOH3 pellets are produced in the same manner as in Example 1, except that the content of crotonaldehyde, 2,4-hexadienal, and 2,4,6-octatrienal in the EVOH3 pellets is shown in Table 5.

[0078] A three layer barrier film was produced on a Collin cast co-extrusion line of PP, adhesive resin (Adh) and EVOH with the following thicknesses: PP1 / Adh2 / EVOH3=352 / 32 / 16μm PP1: Advanced-PP 1104K, density 0.91 g / cm, commercially available from Advanced Petrochemical Company 3 Adh2: ADMER AT1179E, available from Mitsui Chemical Europe GmbH, density 0.91 g / cm 3 .

[0079] The three-layer barrier film is biaxially stretched by 4 times in the machine direction and 4 times in the cross direction at 160°C by tenter frame sequential stretching method. After stretching, the thickness is PP1 / Adh1 / EVOH3=22 / 2 / 1μm.

[0080] The same procedure as described in Example 1 is repeated, except for the preparation of the three-layer barrier film.

[0081] Example 5 The biaxially oriented 3-layer barrier film and 3-layer PE film are produced by the same method as in Example 3. And another 5-layer barrier film using post-consumer recycled PE is produced on a Collin cast co-extrusion line of PE resin, adhesive resin and EVOH, with the thickness as follows: PE6 / adh1 / EVOH1 / adh1 / PE2=85 / 5 / 5 / 5 / 20μm PE6: Post-consumer recycled LDPE resin supplied by Morssinkhof Rymoplast, grade name RYMO-W122, melt index 0.6g / 10min (190°C, load 2.16kg) and density 0.92g / cm 3

[0082] A three-layer PE film is laminated onto the metallized surface of the biaxially oriented three-layer barrier film, and a PE6 layer of a five-layer barrier film is laminated onto the PE surface of the biaxially oriented three-layer barrier film.

[0083] The same procedure as described in Example 3 is repeated, except for the above 5-layer barrier film.

[0084] Example 6 Instead of the PE6 / adh1 / EVOH1 / adh1 / PE2 5-layer membrane shown in Example 5, a PE6 / PE3 / PE2 membrane with thicknesses of 85 / 10 / 25 μm produced on a Collin cast coextrusion line is used for lamination to the PE surface of the biaxially oriented 3-layer barrier film. Otherwise, the same procedure as described in Example 5 is repeated.

[0085] Example 7 The tube body is manufactured by the same procedure as in Example 2, and is combined with the tube shoulder manufactured by three-layer compression molding method with the structure of PE4+Adh1 / EVOH1 / PE4+Adh1. The blend of PE4 and Adh1 is 90 / 10 wt%. The average tube shoulder thickness is 1.1 mm, and the EVOH layer thickness is 50 μm.

[0086] The same procedure as described in Example 3 is repeated except for the tube shoulder.

[0087] Example 8 A three-layer barrier film is produced on a Collin cast coextrusion line using PE, adhesive resin (Adh) and EVOH with thicknesses of PE1 / Adh1 / EVOH4=19 / 3 / 3 μm. The same procedure as described in Example 1 is repeated, except that EVOH4 is used instead of EVOH1.

[0088] Production of EVOH4 EVOH4 pellets are produced in the same manner as in Example 1, except that the amount of crotonaldehyde is changed and 2,4-hexadienal and 2,4,6-octatrienal are added together with crotonaldehyde. The contents of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal in the EVOH4 pellets are shown in Table 5.

[0089] Example 9 A three layer barrier film was produced on a Collin cast co-extrusion line of PE, adhesive resin (Adh) and EVOH with the following thicknesses: PE1 / Adh1 / EVOH4=95 / 15 / 15μm The three-layer barrier film is then uniaxially stretched (machine direction) at 120° C. with a stretch ratio of 5. After stretching, the thickness is PE1 / Adh1 / EVOH4=19 / 3 / 3 μm.

[0090] The same procedure as described in Example 1 is repeated except for the above three-layer barrier film preparation.

[0091] Example 10 A three layer barrier film was produced on a Collin cast coextrusion line of PP, adhesive resin (Adh) and EVOH with the following thicknesses: PP1 / Adh2 / EVOH5=352 / 32 / 16μm

[0092] The three-layer barrier film is biaxially stretched by 4 times in the machine direction and 4 times in the width direction at 160°C by a tenter frame sequential stretching method. After stretching, the thickness is PP1 / Adh1 / EVOH5=22 / 2 / 1μm.

[0093] The same procedure as described in Example 4 is repeated except for the preparation of the three-layer barrier film.

[0094] EVOH5 Production Except for changing the amount of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal, EVOH5 pellets are prepared in the same manner as EVOH3 pellets in Example 4. The contents of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal in EVOH5 pellets are shown in Table 5.

[0095] Examples 11 to 17 Except for changing the amounts of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal, EVOH6-12 pellets are produced in the same manner as EVOH4 pellets in Example 8. The contents of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal in the EVOH6-12 pellets are shown in Table 5.

[0096] A three-layer barrier film is produced in the same manner as in Example 10, except that the EVOH pellets used are changed to EVOH6-12 pellets. The same procedure as described in Example 1 is repeated except for the above three-layer barrier film production.

[0097] The test results and layer thicknesses of Examples 8-17 are summarized in Tables 3 and 4.

[0098] Reference example 1 Instead of the 3 layer barrier film shown in Example 2, a 5 layer barrier film was produced on a Collin cast co-extrusion line of PE, adhesive resin (Adh) and EVOH with the following thicknesses: PE1 / Adh1 / EVOH1 / Adh1 / PE1=40 / 15 / 15 / 15 / 40μm. The 5-layer barrier film is then uniaxially stretched (machine direction) at 120° C. with a stretch ratio of 5. After stretching, the thickness is PE1 / Adh1 / EVOH1 / Adh1 / PE1=8 / 3 / 3 / 3 / 8 μm. The PE surface of the uniaxially oriented 5-layer barrier film is metallized on one side and has an optical density of 3.0.

[0099] The same procedure as described in Example 2 is repeated except for the preparation of the five-layer barrier film.

[0100] Reference example 2 The three layer barrier film shown in Example 1 is not metallized and is provided for lamination and tube manufacturing.

[0101] Other than the above, the same procedure as described in Example 1 is repeated.

[0102]

Table 1

[0103]

Table 2

[0104]

Table 3

[0105]

Table 4

[0106]

Table 5

Claims

1. A plastic tube having a body (A) and a shoulder portion (B), a. The main body (A) is a plastic film laminate having a total thickness of 200 to 500 μm, i.

1. An EVOH layer (a1) having one side metallized or coated with an inorganic oxide; 2. A polyolefin layer (a2), and 3. An adhesive layer (a3) ​​between the non-metallized and non-inorganic oxide coated surface of the EVOH layer (a1) and the polyolefin layer (a2). A multilayer film (A1), ii. A polyolefin film (A2) laminated on the metallized or inorganic oxide coated surface of the EVOH layer (a1) Including, b. The EVOH in the EVOH layer (a1) has an ethylene content of 20 to 50 mol %, c. The thickness of the EVOH layer (a1) is 5 μm or less, d. The oxygen permeability of the main body (A) measured at 23°C and 50% RH in accordance with ISO21309-2 Appendix C is 0.5 cc / m ２ - day-atm or less, plastic tube.

2. 2. The plastic tube according to claim 1, wherein the multilayer film (A1) is uniaxially stretched at a stretch ratio of 3 or more.

3. 2. The plastic tube according to claim 1, wherein the multilayer film (A1) is biaxially stretched at a stretch ratio of 3 or more in both the machine direction and the width direction.

4. The plastic tube according to any one of claims 1 to 3, wherein the melting point of the EVOH layer (a1) is 150°C or lower.

5. The plastic tube according to any one of claims 1 to 4, wherein the EVOH layer (a1) contains crotonaldehyde (X1) and 2,4-hexadienal (X2), the content x1 of the crotonaldehyde (X1) in the EVOH layer (a1) is 0.01 ppm or more and 4.0 ppm or less, and the content x2 of the 2,4-hexadienal (X2) in the EVOH layer (a1) is 0.005 ppm or more and 0.65 ppm or less.

6. The plastic tube according to claim 5, wherein the EVOH layer (a1) optionally contains 2,4,6-octatrienal (X3), the total (x1 + x2 + x3) is 7.0 ppm or less, (x1) is the amount (ppm) of crotonaldehyde (X1) in the EVOH layer (a1), (x2) is the amount (ppm) of 2,4-hexadienal (X2) in the EVOH layer (a1), and (x3) is the amount (ppm) of 2,4,6-octatrienal (X3) in the EVOH layer (a1).

7. The plastic tube according to claim 5 or 6, wherein x1 / (x2+x3) is 2.0 or more and 150.0 or less, (x1) is the amount (ppm) of crotonaldehyde (X1) in the EVOH layer (a1), (x2) is the amount (ppm) of 2,4-hexadienal (X2) in the EVOH layer (a1), and (x3) is the amount (ppm) of 2,4,6-octatrienal (X3) in the EVOH layer (a1).

8. The sum (x2 + 2x3) of the content x2 (ppm) of 2,4-hexadienal (X2) and twice the content x3 (ppm) of 2,4,6-octatrienal (X3) is 0.65 ppm or less. The plastic tube according to any one of claims 5 to 7.

9. The plastic tube according to any one of claims 1 to 8, wherein the main body (A) comprises a polyolefin layer (a5) comprising a post-consumer recycled polyolefin sandwiched between the polyolefin layer (a2) and an additional EVOH layer (a4).

10. The plastic tube according to any one of claims 1 to 9, wherein the multilayer structure (A1) is produced by coextrusion of separate layers (a1) to (a3) ​​and optional layers (a4) and (a5).

11. The plastic tube according to any one of claims 1 to 10, wherein the shoulder portion (B) is a multilayer structure comprising an EVOH layer (b1) sandwiched between two polyolefin layers (b2) and (b3).

12. 12. The plastic tube according to claim 11, wherein the shoulder portion (B) is a multilayer structure having an adhesive layer between the EVOH layer (b1) and the polyolefin layer (b2), and between the EVOH layer (b1) and the polyolefin layer (b3).

13. Use of the plastic tube according to any one of claims 1 to 12 in packaging applications for food, cosmetics or medicines.

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