Xylooligosaccharide-containing resin composition

Abstract

The present invention provides a new method for imparting anti-blocking properties to films and suppressing blocking between the films. More specifically, provided is a composition containing a polyethylene and an xylooligosaccharide.

Description

Xylooligosaccharide-containing resin composition

[0001] This disclosure relates to xylooligosaccharide-containing resin compositions, and more particularly to compositions containing polyethylene and xylooligosaccharides. All documents cited herein (especially those listed in the Prior Art section) are incorporated herein by reference.

[0002] In recent years, packaging and containers made from plastic film have become widely used, aiming to improve convenience, conserve resources, and reduce environmental impact. Compared to conventional molded containers, film offers advantages such as being lightweight, easy to dispose of, and low-cost.

[0003] In the plastic film manufacturing process, films formed using processing equipment are sometimes wound into rolls for storage and transportation. During this process, the films often become blocked, leading to a deterioration in operational efficiency.

[0004] Film blocking can be improved, for example, by reducing the contact area between films. As a method to reduce the contact area between films, a method has been developed in which the roughness of the surface of the formed film is increased by adding an antiblocking agent to the raw resin. This can provide a film with improved antiblocking properties (Patent Documents 1 and 2). In addition to the addition of antiblocking agents, it is known that the antiblocking properties can also be improved by adding lubricants.

[0005] Japanese Patent Publication No. 2022-146705, International Publication No. 2016 / 152836

[0006] The inventors of the present invention considered that in order to obtain a film with excellent antiblocking properties and the ability to suppress blocking between films, it is necessary to have a film with suitably increased surface roughness, and investigated a method for obtaining a film with suitably increased surface roughness.

[0007] The inventors diligently investigated whether a component capable of achieving the above objective could be obtained by processing hemicellulose in various ways. They found that a composition obtained by kneading xylooligosaccharides (preferably neutral xylooligosaccharides) with polyethylene had the potential to be useful in obtaining a film with suitably increased surface roughness, and further investigations were conducted.

[0008] This disclosure includes, for example, the following subjects: 1. A composition containing polyethylene and xylooligosaccharide. 2. The composition according to 1, wherein the xylooligosaccharide is a neutral xylooligosaccharide. 3. The composition according to 1 or 2, wherein the weight-average molecular weight of the xylooligosaccharide is 300 to 2400. 4. The composition according to any one of 1 to 3, wherein the polyethylene:xylooligosaccharide is contained in a mass ratio of 95:5 to 50:50. 5. The composition according to any one of 1 to 4, wherein the content of the xylooligosaccharide is 50% by mass or less relative to the composition, and / or the content of the polyethylene is 50% by mass or more relative to the composition. 6. The composition according to any one of 1 to 5, wherein the polyethylene is at least one selected from the group consisting of LLDPE (linear low-density polyethylene), LDPE (low-density polyethylene), and HDPE (high-density polyethylene). 7. The composition according to any one of 1 to 6, further comprising acid-modified polypropylene. 8. The composition according to claim 7, wherein the content of the acid-modified polypropylene is 0.1 to 20% by mass relative to the composition. Claim 9. A molded article formed from the composition according to any one of claims 1 to 8. Claim 10. A film formed from the composition according to any one of claims 1 to 8. Claim 11. The film according to claim 10, wherein the arithmetic mean roughness of the film in the flow direction is 0.12 μm or more. Claim 12. The film according to claim 10 or 11, wherein the arithmetic mean roughness of the surface of the film is 0.5 μm or more. Claim 13. A film containing polyethylene and xylooligosaccharide, wherein the arithmetic mean roughness of the surface in the flow direction is 0.12 μm or more, and the arithmetic mean roughness of the surface is 0.5 μm or more. Claim 14. The film according to claim 14, formed from the composition according to any one of claims 1 to 9. Claim 15. The film according to any one of claims 10 to 14, having a thickness of 20 to 100 μm.

[0009] A composition containing polyethylene and xylooligosaccharide is provided. A film molded from this composition has suitably increased surface roughness. This is expected to improve antiblocking properties.

[0010] The embodiments included in this disclosure will be described in more detail below. This disclosure preferably includes, but is not limited to, compositions containing polyethylene and xylooligosaccharides, as well as methods for producing the same and uses thereof. This disclosure includes everything disclosed herein and that can be recognized by those skilled in the art.

[0011] As described above, the compositions included in this disclosure contain polyethylene and xylooligosaccharides. Since polyethylene is a type of resin, the compositions included in this disclosure may be referred to as the resin compositions of this disclosure. Furthermore, the xylooligosaccharides contained in the resin compositions of this disclosure may be referred to as the xylooligosaccharides of this disclosure.

[0012] The polyethylene contained in the resin composition of this disclosure is not particularly limited. For example, LLDPE (linear low-density polyethylene), LDPE (low-density polyethylene), MDPE (medium-density polyethylene), or HDPE (high-density polyethylene) can be preferably used. Among these, LLDPE (linear low-density polyethylene) is more preferred. Note that JIS K 6922-1:2018 (and the corresponding international standard ISO 17855-1) describes the density of each polyethylene as follows: LLDPE, LDPE: 910 kg / m³ ３ More than 925kg / m ３ Less than. MDPE: 925 kg / m ３ More than 940kg / m ３ Less than. HDPE: 940 kg / m ３ That's all.

[0013] Furthermore, while there are no particular limitations on polyethylene, polyethylene with a melt index of 0.01 to 12 (g / 10 min) is preferred, and polyethylene with a melt index of 0.05 to 10 (g / 10 min) is more preferred. The upper or lower limit of this range (0.05 to 10 (g / 10 min)) may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, or 9.5 (g / 10 min). This range may also be, for example, 0.3 to 10 (g / 10 min) or 0.3 to 8 (g / 10 min). Among these, LDPE with a melt index of 0.3 to 10 (g / 10 min), LLDPE with a melt index of 0.3 to 10 (g / 10 min), and HDPE with a melt index of 0.05 to 10 (g / 10 min) are more preferred. The melt index of polyethylene is measured using a melt indexer as the mass (g) of resin extruded from an orifice with an inner diameter of 2.095 mm × length of 8.000 mm for 10 minutes under a load of 2.16 kg (21.6 N) at 190°C.

[0014] Furthermore, polyethylene can be used alone or in combination of two or more types.

[0015] Furthermore, the resin composition of this disclosure may contain resins other than polyethylene, to the extent that they do not impair the effects of the composition. Examples of such resins other than polyethylene include polypropylene, polyethylene, polycarbonate, polyethylene terephthalate, and block copolymers in which two or more of these are linked together. Resins other than polyethylene can be used individually or in combination of two or more.

[0016] The xylooligosaccharides contained in the resin composition of this disclosure (xylooligosaccharides of this disclosure) are, as described above, xylooligosaccharides with low acidity, and more specifically, xylooligosaccharides with a uronic acid content of 2% by mass or less. The uronic acid content is measured as follows.

[0017] Dissolve 10 g of boric acid and 15 g of sodium chloride in 1 L of water to prepare a solvent. Weigh 40 mg of xylooligosaccharide to be measured, dissolve it in the above solvent, and adjust the volume to 50 mL. Measure 4 mL of the solution, add more of the above solvent, and adjust the volume to 20 mL. Transfer 0.5 mL of the obtained 20 mL solution to a test tube, add 5 mL of sulfuric acid while cooling in ice water, mix, and heat in a water bath for 10 minutes. Cool immediately in ice cooling, add 0.2 mL of 1,2-dimethylphenol test solution, mix, heat in a water bath for 15 minutes, and leave to cool to obtain a sample solution. Separately, prepare a D-glucuronic acid standard stock solution with a concentration of 10 to 100 μg / mL, perform the same procedure to obtain a standard solution, and measure the absorbance at wavelengths of 400 nm and 450 nm. (Note that glucuronic acid is the main uronic acid in xylooligosaccharides.) Prepare a calibration curve from the absorbance of the standard solution, determine the amount (g) of uronic acid in the xylooligosaccharide to be measured, and then determine the uronic acid content (% by mass) according to the following formula. If the quantitative value is negative, it is regarded as 0%.

[0018] Uronic acid content (% by mass) = M Ｓ / M Ｔ × (A Ｔ４５０ - A Ｔ４００ ) / (A Ｓ４５０ - A Ｓ４００ ) × 10 M Ｓ : Weighed mass of D-glucuronic acid (mg) M Ｔ : Weighed mass of xylooligosaccharide converted to dry mass (mg) A Ｔｉ : Absorbance of the sample solution at each wavelength (i: 450 nm or 400 nm) A Ｓｉ : Absorbance of the standard solution at each wavelength (i: 450 nm or 400 nm). In the xylooligosaccharide of the present disclosure, the uronic acid content is preferably 0 to 2% by mass. 0% by mass indicates that no uronic acid can be detected by the aforementioned uronic acid content measurement method (below the detection limit; the quantitative value is 0 or negative). This product is sometimes referred to as neutral xylooligosaccharide. The upper limit of the above range (0 to 2% by mass) may be, for example, 1.5, 1, 0.5, 0.3, 0.2, or 0.1% by mass. For example, the range may be 0 to 1.5% by mass.

[0019] Furthermore, the xylooligosaccharides of this disclosure are preferably those having a number-average molecular weight of 300 to 2400. The upper or lower limits of this range may be, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, or 2300. The range is more preferably 500 to 2000, and even more preferably 600 to 1800.

[0020] Furthermore, the xylooligosaccharides of this disclosure are preferably those having a weight-average molecular weight of 300 to 2400. The upper or lower limits of this range may be, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, or 2300. The range is more preferably 500 to 2000, and even more preferably 600 to 1800.

[0021] The weight-average molecular weight is a value obtained by GPC (gel permeation chromatography), and more specifically, a value obtained by GPC under the following conditions: GPC column: Two Ultrahydrogel 250 columns linked together from Waters Japan Eluent: A mixture of aqueous solutions of 0.3 M sodium nitrate and 0.01 M disodium hydrogen phosphate with methanol in a volume ratio of 4:1 Flow rate: 0.7 mL / min Measurement temperature: 40°C Detector: Differential refractive index detector Furthermore, the xylooligosaccharide of this disclosure preferably has an average degree of polymerization of 2 to 16. The upper or lower limit of this range may be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. The range is more preferably 2 to 14, even more preferably 4 to 12, and even more preferably 3 to 6.

[0022] The average degree of polymerization is calculated from the molecular weight (132) and number-average molecular weight of the repeating unit of the xylooligosaccharide. More specifically, the average degree of polymerization can be calculated using the formula {number-average molecular weight × (1 - uronic acid content)} / 132. For example, the average degree of polymerization for a uronic acid content of 2% by mass can be calculated using the formula {number-average molecular weight × (1 - 0.02)} / 132. Also, for example, the average degree of polymerization for a uronic acid content of 0% by mass can be calculated using the formula number-average molecular weight / 132.

[0023] Examples of xylooligosaccharide structural formulas are shown below. However, these examples are not limited to the xylooligosaccharides of this disclosure and are merely illustrative. Furthermore, the number of 4-o-methylglucuronic acid molecules described in these examples may be zero (in this case, it indicates a xylooligosaccharide with a uronic acid content of 0% by mass).

[0024]

[0025] The xylooligosaccharides of this disclosure can be obtained, for example, by depolymerizing plant-derived raw materials. This is described in detail below.

[0026] Examples of plant-derived raw materials include wood-derived raw materials, seed-derived raw materials, grain-derived raw materials, and fruit-derived raw materials. Additionally, plant-derived raw materials such as cotton linters and cotton lint, kenaf, hemp, ramie, and rice straw (herbaceous plants) can also be used. Combinations of the above-mentioned plant-derived raw materials are also permitted.

[0027] In particular, it is preferable to use wood-derived raw materials as plant-derived raw materials. Examples of wood-derived raw materials include coniferous trees and broad-leaved trees. It is preferable to use at least one type of wood-derived raw material selected from coniferous trees and broad-leaved trees, and it is more preferable to use broad-leaved trees. A mixture of coniferous trees and broad-leaved trees may also be used as wood-derived raw materials. In addition, tree bark may be used as wood-derived raw material.

[0028] Examples of hardwoods include beech, *Eucalyptus globulus*, *Eucalyptus grandis*, *Eucalyptus urograndis*, *Eucalyptus pellita*, *Eucalyptus brassiana*, and *Acacia melanoxylon*. Examples of softwoods include cedar, cypress, pine, hiba, and hemlock.

[0029] The bulk density of the wood-derived raw material is 450 kg / m 3 or more and 700 kg / m 3 or less, preferably 500 kg / m 3 or more and 650 kg / m 3 or less. By setting the bulk density of the wood-derived raw material within the above range, the production efficiency of xylooligosaccharides can be further improved.

[0030] The wood-derived raw material is preferably a wood chip obtained by crushing the above-mentioned wood. By using wood chips as the plant-derived raw material, the depolymerization of the plant-derived raw material can be promoted efficiently, and the production efficiency of xylooligosaccharides can be improved. (First step) <Depolymerization step> The first step includes a step of depolymerizing a plant-derived raw material. In the step of depolymerizing a plant-derived raw material, the plant-derived raw material can be chemically and / or physically decomposed to produce xylooligosaccharides. Examples of the chemical and / or physical decomposition step include a heat treatment step, an alkali treatment step, an acid treatment step, an enzyme treatment step, an ionic liquid treatment step, and a catalyst treatment step. Among these, the depolymerization step is preferably a heat treatment step or an enzyme treatment step, and more preferably a heat treatment step. Further, the heat treatment step may be a heating and pressurizing step.

[0031] The depolymerization step is preferably performed under non-alkaline conditions (pH 9 or less, more preferably pH 8 or less).

[0032] The heat treatment step is a step of heating a plant-derived raw material in the presence of a solution. Since the plant-derived raw material is hydrolyzed in such a heat treatment step, the heat treatment step is sometimes referred to as a hydrolysis step or a pre-hydrolysis step. The solution used in the heat treatment step is preferably water, and the ratio (mass ratio) of water to the plant-derived raw material is preferably 1:1 to 1:10. By setting the ratio of water to the plant-derived raw material within the above range, the hydrolysis reaction can proceed efficiently. The water used in the heat treatment step may be water added separately from the plant-derived raw material, or part of it may be water originally contained in the plant-derived raw material.

[0033] In the heat treatment step, other chemicals may be added in addition to the plant-derived raw material and water. Examples of other chemicals include alkalis, acids, and chelating agents. Chemicals that directly or indirectly assist depolymerization of polysaccharides, such as scale inhibitors, pitch control agents, and ionic liquids, may also be added.

[0034] The heat treatment step is a step of heating a plant-derived raw material in the presence of water, and the heating temperature (liquid temperature) at this time is preferably 30°C or higher, more preferably 50°C or higher, still more preferably 75°C or higher, even more preferably 90°C or higher, particularly preferably 100°C or higher, and most preferably 120°C or higher. Further, the heating temperature (liquid temperature) is preferably 300°C or lower, more preferably 250°C or lower, and still more preferably 200°C or lower.

[0035] The treatment time in the heat treatment step can be appropriately determined depending on the treatment temperature. For example, the treatment time is preferably 5 minutes or longer, more preferably 10 minutes or longer, and still more preferably 20 minutes or longer. The P-factor represented by the following formula is the product of temperature and time during heat treatment, and it is preferable to adjust the P-factor within a preferable range.

[0036]

[0037] In the above formula, P represents the P-factor, T represents the absolute temperature (°C + 273.5), t represents the heat treatment time, and K H1(T) / K 100℃ This represents the relative rate of hydrolysis of glycosidic bonds.

[0038] In the heat treatment process, the P-factor is preferably 200 or higher, more preferably 250 or higher, and even more preferably 300 or higher. It is also preferable that the P-factor be 1000 or lower. By appropriately adjusting the P-factor during the heat treatment process, the average degree of polymerization and thus the molecular weight of the xylooligosaccharide can be brought within a desired range.

[0039] In the heat treatment process, the pH of the solution containing the plant-derived raw materials is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less. In other words, the heat treatment process is preferably carried out under non-alkaline conditions. Note that the above pH values ​​refer to the pH of the solution before the heat treatment.

[0040] During the heat treatment process, acids derived from the raw materials may dissociate, and acid hydrolysis may occur in at least part of the process. Examples of acids derived from plant materials include organic acids such as acetic acid and formic acid. In this case, the pH of the solution containing the plant-derived raw materials after acid hydrolysis will decrease further.

[0041] In the manufacturing method, it is preferable to include a heat treatment step as the first step. This can increase the production efficiency of xylooligosaccharides. By including a heat treatment step as the first step, the number of steps required to obtain xylooligosaccharides can be significantly reduced compared to conventional methods. Furthermore, by including a heat treatment step under non-alkaline conditions as the first step, hexenuronic acid does not substitute for xylooligosaccharides, and xylooligosaccharides with suppressed discoloration can be efficiently produced.

[0042] The depolymerization step is preferably a heat treatment step, but other steps can also be used. For example, if the depolymerization step is an enzyme treatment step, the depolymerization step includes a step of mixing the plant-derived raw material with the enzyme. As the enzyme, for example, hemicellulase can be used. Specifically, commercially available enzyme preparations such as Cellulosin HC100 (manufactured by HBI), Cellulosin TP25 (manufactured by HBI), Cellulosin HC (manufactured by HBI), Cartazyme (manufactured by Clariant), Ecopulp (manufactured by Rohm Enzyme Co., Ltd.), Sumizyme (manufactured by Shin Nippon Chemical Industries, Ltd.), Pulpzyme (manufactured by Novo Nordics), and Multifect 720 (manufactured by Genencore) can be used, as well as xylanases produced by microorganisms such as Trichoderma, Thermomyces, Oureobasidium, Streptomyces, Aspergillus, Clostridium, Bacillus, Thermotoga, Thermoasuchus, Cardocerum, and Thermomonospora.

[0043] In the enzyme treatment process, the enzyme is added to a solution obtained by mixing plant-derived raw materials and water. The temperature of the solution at this time is preferably between 10°C and 90°C, and more preferably between 30°C and 60°C. It is preferable that the temperature of the solution be close to the optimal temperature of the enzyme used. Furthermore, it is preferable to adjust the pH of the solution to a range that enhances the activity of the enzyme, for example, adjusting the pH to between 3 and 10 is preferable.

[0044] Furthermore, if the depolymerization step involves an alkali treatment step or an acid treatment step, it includes a step of mixing the plant-derived raw material with an alkaline solution or an acid solution. In the alkali treatment step, it is preferable to add sodium hydroxide or potassium hydroxide. In the acid treatment step, it is preferable to add hydrochloric acid, sulfuric acid, acetic acid, etc. In this case as well, heating or pressurization may be performed as appropriate.

[0045] If the depolymerization step is selected from at least one of the enzyme treatment step, alkali treatment step, and acid treatment step, then further steps such as pressing, extraction, heating, filtration, separation, purification, concentration, and desalting may be provided after the treatment step. In addition, it may be necessary to provide a low-molecular-weight step after the treatment step. Other steps include those described in Japanese Patent Application Publication No. 2003-183303, and the contents of these steps are incorporated herein by reference. <Filtration Step> The first step may further include a filtration step after the depolymerization step described above. In the filtration step, the plant-derived raw material is separated into solids and a solution excluding the solids. Specifically, by providing a filtration step after the depolymerization step, the material is separated into solids that will become pulp raw materials and a filtrate. The solids that will become pulp raw materials are then processed in a subsequent step such as a pulping step to become cellulose raw materials (dissolved pulp).

[0046] The recovered filtrate can be separated into a gas layer and a liquid layer. The gas layer contains a large amount of furfural compounds, and by recovering these, the furfural compounds can be isolated. On the other hand, the liquid layer contains a large amount of hemicellulose containing xylooligosaccharides. In the process described later, xylooligosaccharides with low acidity (in particular xylooligosaccharides with a uronic acid content of 2% by mass or less, preferably neutral xylooligosaccharides) contained in this liquid layer can be separated and purified. <Separation and Purification Process> The first process may further include a separation and purification process after the depolymerization process described above. If the first process includes the filtration process described above, it is preferable that the separation and purification process be provided after the filtration process.

[0047] It is preferable to provide a filtration step after the depolymerization step, and further to provide a separation and purification step after the filtration step. In the first step, the separation and purification step may be provided immediately after the depolymerization step, but it is preferable to provide a filtration step after the depolymerization step, and to provide a step to separate and purify low-acidity xylooligosaccharides from the obtained filtrate. The filtration step may be provided as part of the separation and purification step, or it may be provided as a separate step independent of the separation and purification step. The separation and purification step is a step to separate and purify low-acidity xylooligosaccharides. Since the filtrate obtained in the filtration step contains high-acidity xylooligosaccharides in addition to low-acidity xylooligosaccharides, the separation and purification step is also a step to remove these other sugars.

[0048] In the separation and purification process, it is preferable to employ methods such as ion exchange chromatography, affinity chromatography, gel filtration, ion exchange treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, and activated carbon treatment. It is also preferable to combine multiple of the above methods in the separation and purification process. In particular, by performing ion exchange chromatography in the separation and purification process, low-acidity xylooligosaccharides can be selectively separated and purified. In ion exchange chromatography, low-acidity xylooligosaccharides can be mainly extracted from the permeate by adsorbing high-acidity xylooligosaccharides. Specifically, the sugar solution is first treated with a strong cation exchange resin to remove metal ions from the sugar solution. Next, sulfate ions and other substances are removed from the sugar solution using a strong anion exchange resin. Then, it is treated with a weak anion exchange resin to adsorb high-acidity xylooligosaccharides onto the resin. <Concentration Step> The first step may further include a concentration step. The concentration step is preferably provided, for example, after the filtration step and before the separation and purification step. By providing such a concentration step, the separation and purification process can be carried out more efficiently.

[0049] Concentration processes include, for example, membrane treatment processes using NF membranes, ultrafiltration membranes, reverse osmosis membranes, etc., and concentration processes using evaporation, etc.

[0050] In the concentration step, it is preferable to concentrate the solution so that the content of low-acidity xylooligosaccharides is 10% to 80% of the total mass of the concentrate, and more preferably 20% to 60%. <Dehydration step> The low-acidity xylooligosaccharides obtained in the first step may be obtained as a low-acidity xylooligosaccharide solution, but by going through the dehydration step, they may be obtained as a low-acidity xylooligosaccharide concentrate or a low-acidity xylooligosaccharide powder. When producing low-acidity xylooligosaccharide powder, it is preferable to further provide a powdering step after the separation and purification step. In the present invention, by providing a dehydration step, the sulfation in the sulfation step described later can be carried out efficiently.

[0051] In the powdering process, the low-acidity xylooligosaccharide solution obtained in the separation and purification process can be treated with, for example, a spray dryer, freeze dryer, hot air dryer, or water-soluble organic solvent to obtain a low-acidity xylooligosaccharide powder.

[0052] In the resin composition of the present disclosure, the xylooligosaccharide of the present disclosure is preferably contained in a mass ratio of 0.01 times or more, more preferably 0.02 times or more, even more preferably 0.05 times or more, and even more preferably 0.1 times or more compared to polyethylene. Furthermore, although not particularly limited, the xylooligosaccharide of the present disclosure is preferably contained in a mass ratio of 1.5 times or less, and more preferably 1 time or less compared to polyethylene. The upper or lower limit of the mass ratio range of the xylooligosaccharide content relative to polyethylene (0.01 to 1.5 times) may be, for example, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, or 1.4 times. For example, the range may be 0.05 to 1.2 times or 0.1 to 1 time.

[0053] Furthermore, for example, the mass ratio of polyethylene to the xylooligosaccharide is preferably 95:5 to 50:50, more preferably 95:5 to 55:45, 95:5 to 60:40, 95:5 to 65:35, 95:5 to 70:30, or 95:5 to 75:25, even more preferably 95:5 to 80:20, and even more preferably 95:5 to 85:15.

[0054] Furthermore, in the resin composition of this disclosure, polyethylene is preferably contained in an amount of 50% by mass or more, more preferably in an amount of 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, or 85% by mass or more, and even more preferably in an amount of 90% by mass or more. Furthermore, in the resin composition of this disclosure, xylooligosaccharide is preferably contained in an amount of 50% by mass or less, more preferably in an amount of 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less, and even more preferably in an amount of 10% by mass or less.

[0055] The resin composition of this disclosure may contain other components in addition to polyethylene and the xylooligosaccharide of this disclosure, as long as they do not impair the effects of the resin composition of this disclosure. Such other components may include known resin composition additives, and more specifically, examples include dispersants, antioxidants, lubricants, fillers, plasticizers, flame retardants, ultraviolet absorbers, colorants, antistatic agents, antibacterial agents, antifungal agents, modifiers, nucleating agents, etc. The content of these components can be appropriately adjusted within the range that the effects of the resin composition of this disclosure are achieved. Furthermore, these components can be used individually or in combination of two or more.

[0056] While not particularly limited, acid-modified polypropylene is a preferred example of a dispersant. In particular, acid-modified polypropylene is preferred as a dispersant. Such acid-modified polypropylene acting as a dispersant is commercially available as Yumex (Sanyo Chemical Industries, Ltd.), and can be purchased and used as is. While not particularly limited, the acid-modified polypropylene used as a dispersant has a weight-average molecular weight of approximately 9,000 to 70,000 as measured by GPC method. The upper or lower limits of the range are, for example, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 21000, 22000, 23000, 24000, 25000, 26000, 27000, 28000, 29000, 30000, 31000, 32000, 33000, 34000, 35000, 36000, 37000, 38000, 39 The range may be 000, 40000, 41000, 42000, 43000, 44000, 45000, 46000, 47000, 48000, 49000, 50000, 51000, 52000, 53000, 54000, 55000, 56000, 57000, 58000, 59000, 60000, 61000, 62000, 63000, 64000, 65000, 66000, 67000, 68000, or 69000. For example, the range is more preferably 10000 to 50000, and even more preferably 20000 to 45000. Furthermore, an acid value (mgKOH / g) of approximately 10 to 60 is preferred, a value of approximately 40 to 60 is more preferred, and a value of approximately 50 to 60 is even more preferred.

[0057] When a dispersant is used, its content can be set as appropriate, for example, 0.1 to 20% by mass relative to the resin composition of this disclosure. The upper or lower limit of this range may be, for example, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19% by mass. This range may be, for example, 0.2 to 10% by mass, or 0.2 to 5% by mass.

[0058] Furthermore, although not particularly limited, preferred antioxidants include phenolic antioxidants, phosphoric acid antioxidants, sulfuric acid antioxidants, and amine antioxidants, with phenolic antioxidants and phosphoric acid antioxidants being more preferred, and phenolic antioxidants being even more preferred. Examples of phenolic antioxidants include monophenolic antioxidants, bisphenolic antioxidants, and hindered phenolic antioxidants, with hindered phenolic antioxidants being preferred among them. Examples of hindered phenolic antioxidants include IRGANOX 1010, IRGANOX 1076, IRGANOX 1081, and IRGANOX 1300 (all from BASF). Although not particularly limited, hindered phenolic antioxidants with a molecular weight of 500 or more are preferred, and those with a molecular weight of 600 or more are more preferred. Furthermore, there is no particular upper limit to the molecular weight, but for example, those with a molecular weight of 1500 or less are preferred, and those with a molecular weight of 1300 or less or 1200 or less are more preferred. The upper or lower limit of the molecular weight range (500 to 1500) may be, for example, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, or 1450. The range may be, for example, 550 to 1300 or 600 to 1200. When an antioxidant (particularly preferably a hindered phenol antioxidant) is used, its content can be set as appropriate, for example, 0.005 to 0.3% by mass relative to the resin composition of this disclosure. The upper or lower limit of the range may be, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, or 0.25 mass%. The range may be, for example, 0.01 to 0.25 mass%, or 0.02 to 0.2 mass%.

[0059] The resin compositions of this disclosure can be prepared by known methods or by methods readily conceivable from known methods. For example, they can be prepared by kneading (preferably by melt kneading) polyethylene and xylooligosaccharides, and other components as needed. For kneading, known suitable equipment such as a twin-screw extruder can be used. Alternatively, polyethylene (and / or xylooligosaccharides) may be added to the resulting knead and kneaded further in the same manner.

[0060] The resin compositions of this disclosure can be preferably used to prepare various molded articles. Such molded articles are preferably those having a film-like form, such as bags or films.

[0061] Furthermore, this disclosure preferably includes films having suitably increased surface roughness and improved antiblocking properties. Such films may be referred to as the films of this disclosure.

[0062] The films of this disclosure can be prepared, for example, by molding from the resin compositions of this disclosure. The molding method is not particularly limited, and known film molding methods or methods that can be easily conceived from known film molding methods can be used. For example, the air-cooled inflation method, the T-die-casting method, etc., can be used.

[0063] The composition of the film of this disclosure is preferably the same as the description of the composition of the resin composition of this disclosure described above.

[0064] The thickness of the film of this disclosure is preferably, for example, 20 to 100 μm. The upper or lower limit of this range may be, for example, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 μm. This range may be, for example, 20 to 95 μm, 25 to 90 μm, or 30 to 85 μm. It may also be 20 to 40 μm or 25 to 35 μm. The thickness of the film is determined by using a thickness gauge to measure the thickness at 12 random locations in 1 μm increments and calculating the average value. An example of a thickness gauge is the L&W 251 (manufactured by Lorentzen & Wettre).

[0065] The film of this disclosure preferably has an arithmetic mean roughness (linear roughness) of 0.12 μm or more in the MD (machine direction) direction (also called the flow direction). The upper limit of the arithmetic mean roughness is not particularly limited, but for example, 5 μm is an example. The upper or lower limits of the range (0.12 to 5 μm) are, for example, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0. The range may be 47, 0.48, 0.49, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, or 4.9 μm. The range may be, for example, 0.13 to 4.9 μm, or 0.15 to 4.8 μm.

[0066] Furthermore, the film of this disclosure preferably has an arithmetic mean surface roughness (surface roughness) of 0.5 μm or more. The upper limit of the arithmetic mean roughness is not particularly limited, but for example, it is 10 μm. The upper or lower limits of the range (0.5 to 10 μm) are, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 , 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, or 9.9 μm. The range may be, for example, 1 to 9 μm, or 1.5 to 8 μm.

[0067] These arithmetic mean roughness values ​​are obtained by image analysis using a laser microscope equipped with a white light interferometer. More specifically, for the arithmetic mean roughness (line roughness) in the MD direction, 60 straight lines are drawn in the MD direction on the image of the film surface obtained using a laser microscope equipped with a white light interferometer. After cutting off these lines at a cutoff value (λc), the arithmetic mean roughness (Ra [μm]) is calculated. Cutting off at the cutoff value means removing wavelengths longer than the cutoff value (i.e., large undulations). Such long wavelengths (large undulations) can originate from, for example, the tilt of the sample, surface undulation due to film deposition, roll marks, etc. The cutoff value is determined by the method described in JIS B 0633:2001 (especially section 7.2.1). (The reference length of the roughness curve in Table 1 of Section 7.2.1(b) becomes the cutoff value.) Furthermore, the arithmetic mean roughness (surface roughness) of the film surface is measured in accordance with ISO 25178-2:2012 on an image of the film surface obtained by a laser microscope equipped with a white light interferometer, and the arithmetic mean roughness (Sa [μm]) of the entire area of ​​the measurement range (525 μm in the MD direction × 700 μm in the CD direction) is calculated. A preferred example of such a laser microscope equipped with a white light interferometer is the "VK-X3000" manufactured by Keyence Corporation.

[0068] The film disclosed herein can be used in a variety of products. For example, it can be suitably used in functional films, functional sheets, various types of packaging and bags, etc. Examples of functional films and functional sheets include optical films, optical sheets, protective films, and protective sheets.

[0069] In this specification, the term "comprising" includes both "consisting essentially of" and "consisting of." Furthermore, this disclosure encompasses all combinations of the constituent elements described herein.

[0070] Furthermore, the various characteristics (properties, structure, function, etc.) described for each embodiment of this disclosure described above may be combined in any way to identify the subject matter covered by this disclosure. In other words, this disclosure covers all subject matter consisting of any combination of the combinable characteristics described herein.

[0071] The embodiments of this disclosure will be described in more detail below with examples, but the embodiments of this disclosure are not limited to the examples below.

[0072] In the following examples, LLDPE (linear low-density polyethylene) (Sabic LLDPE M500026) was used as the polyethylene.

[0073] Preparation of neutral xylooligosaccharide: 10 parts by mass of wood chips (hardwood) were mixed with 40 parts by mass of water and heat-treated at 160°C for 3 hours. Then, solid-liquid separation was performed using a screw press (Shinryo Seisakusho: 250 x 1000 SPH-EN), and the filtrate was recovered. The filtrate was filtered through a bag filter with a micron rate of 1 μm (ISP Filters), 5 parts by mass of activated carbon (Mikura Kasei Co., Ltd.: PM-SX) were added, and the mixture was treated at 50°C for 2 hours. Finally, the mixture, including the activated carbon, was filtered through a ceramic filter with a micron rate of 0.2 μm (Nippon Pall Co., Ltd.) to recover a clear filtrate. The clarified filtrate was concentrated 20-fold using a reverse osmosis membrane (Nitto Denko Corporation: NTR-7450) to obtain a concentrated sugar solution. This concentrated sugar solution was then passed through a four-bed, four-column ion exchange resin consisting of a strong cationic resin (Mitsubishi Chemical Corporation: PK-218), a weak anionic resin (Mitsubishi Chemical Corporation: WA30), a strong cationic resin (Mitsubishi Chemical Corporation: PK-218), and a weak anionic resin (Mitsubishi Chemical Corporation: WA30) at a space velocity (SV) of 1.5 to recover a neutral xylooligosaccharide solution. Sodium hydroxide was added to the obtained neutral xylooligosaccharide solution to adjust the pH to 13, and the mixture was stirred at room temperature for 3 hours to carry out deacetylation. Hydrochloric acid was added to the resulting solution to adjust the pH to less than 5, and the mixture was powdered using a spray dryer (Okawara Chemical Machinery Co., Ltd.).

[0074] Measurement of uronic acid content of xylooligosaccharides The uronic acid content of xylooligosaccharides was measured as follows.

[0075] A solvent was prepared by dissolving 10 g of boric acid and 15 g of sodium chloride in 1 L of water. 40 mg of neutral xylooligosaccharide or acidic xylooligosaccharide (or commercially available xylan (Biosynth)) was weighed out and dissolved in the solvent to make 50 mL. 4 mL of this solution was weighed out and the solvent was added to make 20 mL.

[0076] 0.5 mL of the obtained 20 mL of solution was taken into a test tube, 5 mL of sulfuric acid was added while cooling in ice water, and the mixture was heated in a water bath for 10 minutes. Immediately after, it was cooled in ice, 0.2 mL of 1,2-dimethylphenol reagent was added and mixed, and the mixture was heated in a water bath for 15 minutes, after which it was allowed to cool to obtain the sample solution. Separately, a D-glucuronic acid standard stock solution with a concentration of 10–100 μg / mL was prepared, and the same procedure was performed to obtain the standard solution, and the absorbance at wavelengths of 400 nm and 450 nm was measured. A calibration curve was created from the absorbance of the standard solutions, and the amount of uronic acid (g) of xylooligosaccharide was determined. The uronic acid content (mass%) was calculated using the following formula. If the quantitative value was negative, it was considered to be 0%.

[0077] Amount of uronic acid (mass %) = M Ｓ / M Ｔ × (A Ｔ４５０ -A Ｔ４００ ) / ( A Ｓ４５０ -A Ｓ４００ ) × 10 M Ｓ : Amount of D-glucuronic acid weighed (mg) M Ｔ : Amount of xylooligosaccharide weighed out (mg) on ​​a dry basis. Ｔｉ Absorbance of the sample solution at each wavelength (i: 450 nm or 400 nm) A Ｓｉ Absorbance measurements of the standard solution at various wavelengths (i: 450 nm or 400 nm) revealed that the uronic acid content of the prepared neutral xylooligosaccharide was 0.0% by mass.

[0078] Molecular Weight Analysis of Xylooligosaccharides The weight-average molecular weight of xylooligosaccharides was determined by GPC (gel permeation chromatography) under the following conditions: GPC column: Two linked Ultrahydrogel 250 columns manufactured by Waters Japan Eluent: A mixture of aqueous solutions of 0.3 M sodium nitrate and 0.01 M disodium hydrogen phosphate with methanol in a volume ratio of 4:1 Flow rate: 0.7 mL / min Measurement temperature: 40°C Detector: Differential refractive index detector The number-average molecular weight of neutral xylooligosaccharides was found to be 688. The average degree of polymerization of neutral xylooligosaccharides is calculated by dividing the number-average molecular weight by the molecular weight of the repeating unit of the xylooligosaccharide (132) (688 ÷ 132), resulting in approximately 5.2. The weight-average molecular weight of neutral xylooligosaccharides was found to be 889.

[0079] <Film Preparation and Investigation (1)> Masterbatch Preparation 50 parts by mass of neutral xylooligosaccharide, 47.9 parts by mass of polyethylene (Sabic LLDPE-MG50026), 2.0 parts by mass of acid-modified polypropylene, and 0.1 parts by mass of phenolic antioxidant were placed in a super mixer and mixed for 3 minutes to obtain a mixture. The mixture was fed in a single batch from the base of a 30 mm twin-screw extruder (L / D 52.5), extruded at a temperature of 160°C, cooled the strands (extruded mixture) with water, and then pelletized (cut into pellets) to produce a masterbatch (pellets of the above mixture).

[0080] In this study, Sanyo Chemical Industries, Ltd.'s Yumex 1010 was used as the acid-modified polypropylene, and BASF's IRGANOX 1010 was used as the phenolic antioxidant.

[0081] Yumex 1010 is an acid-modified polypropylene, represented by the following formula. Its weight-average molecular weight (GPC method) is approximately 23,000, and its acid value is 52 mgKOH / g (JIS K 0070).

[0082]

[0083] Furthermore, IRGANOX1010 is a hindered phenol antioxidant and is represented by the following formula.

[0084]

[0085] Film and bag production: After mixing the masterbatch and polyethylene (LLDPE (linear low-density polyethylene): Sabic LLDPE-MG50026), the mixture was fed into an inflation molding machine to form a film. That is, it was fed into an extruder via a hopper and heated and melted. At this time, the polyethylene was added so that the proportion of neutral xylooligosaccharides in the final resin composition was 9.6% by mass. The molten resin composition was kneaded by the screw in the extruder, pressurized and poured into the die, and blown upward through the lip of the die. At the same time, a certain amount of air was injected from inside the die to blow up (i.e., blow molding). Air was also blown from the outside to cool the molded product and solidify the resin composition. At the same time, it was pulled upward, and the balloon-shaped molded product was crushed with pinch rolls to obtain a tubular film. After that, the tubular film was wound up with a winding device and cut to a predetermined size to obtain bags.

[0086] The thickness of the obtained bag film was measured as follows: A clean area of ​​the film surface, free from scratches and dirt, was selected, and the thickness was measured randomly at 12 locations in 1 μm increments using a thickness gauge (Lorentzen & Wettre: L&W 251). The average value was calculated and used as the film thickness. The film thickness of Example 1 was 31.1 μm, and the film thickness of Comparative Example 1 was 31.5 μm.

[0087] Measurement of film surface roughness: An arbitrary area of ​​the film surface free of scratches and dirt was selected, and images were captured using a laser microscope equipped with a white light interferometer (Keyence Corporation: VK-X3000) in a range of 525 μm in the MD (machine direction) direction and 700 μm in the CD (cross direction) direction (white light interferometer mode, 10x magnification). Using roughness analysis software (Keyence Corporation: VK-A3), the line roughness of the captured images was calculated based on JIS B0601-2001 and JIS B0671-2002.

[0088] Specifically, line roughness was calculated as the arithmetic mean roughness (Ra [μm]) after cutting off 60 straight lines drawn in the MD direction of the captured image at a cutoff value (λc). Cutting off at the cutoff value means removing wavelengths longer than the cutoff value (i.e., large undulations). Such long wavelengths (large undulations) can arise from, for example, the tilt of the sample, surface undulations due to film deposition, roll marks, etc.

[0089] The cutoff value was determined by the method described in JIS B 0633:2001 (particularly section 7.2.1). (The reference length of the roughness curve in Table 1 of section 7.2.1b becomes the cutoff value.) The specific cutoff value used is also shown in the table below.

[0090] Furthermore, surface roughness was measured based on ISO 25178-2:2012 for the captured images, and calculated as the arithmetic mean roughness (Sa [μm]) of the entire area of ​​the captured image (525 μm in the MD direction × 700 μm in the CD direction).

[0091] The measurement results for the film are shown in the table below. The percentages in the table represent mass percentages.

[0092]

[0093] <Film Preparation and Examination (2)> Neutral xylooligosaccharide, polyethylene (low-density polyethylene (LDPE): Novatec LD-LF640H, melt index (MI) is 7), acid-modified polypropylene, and a phenolic antioxidant were placed in a super mixer and mixed for 3 minutes to obtain a mixture with the composition shown in the table below. The neutral xylooligosaccharide, acid-modified polypropylene, and phenolic antioxidant used were the same as described above. The obtained mixture was extruded using a 40 mm single-screw extruder (L / D: 32) by feeding the mixture in a batch from the base of the extruder and processing at a temperature of 175°C. After cooling the strands with water, pellets were produced by pelletizing (cutting into pellet shapes). L / D = effective screw length (L) / screw diameter (D).

[0094] The pellets were fed into an inflation molding machine to form a film. Specifically, the pellets were fed into an extruder via a hopper and heated and melted. The molten resin composition was kneaded by the screw inside the extruder, pressurized, and poured into a die. At the same time, a certain amount of air was injected from inside the die to blow up (i.e., blow molded). Air was also blown from the outside to cool the molded product, solidifying the resin composition, and at the same time, it was pulled upwards. The balloon-shaped molded product was then crushed with pinch rolls to obtain a tubular film. Subsequently, the tubular film was wound up with a winding device and cut to a predetermined size to obtain a bag.

[0095] Then, in the same manner as described above, the film thickness and surface irregularities of the obtained bags were measured. The results are shown in the table below. The percentages in the table represent mass percentages.

[0096]

Claims

1. A composition containing polyethylene and xylooligosaccharide.

2. The composition according to claim 1, wherein the xylooligosaccharide is a neutral xylooligosaccharide.

3. The composition according to claim 1 or 2, wherein the weight-average molecular weight of the xylooligosaccharide is 300 to 2400.

4. The composition according to claim 1 or 2, wherein polyethylene and xylooligosaccharides are contained in a mass ratio of 95:5 to 50:

50.

5. The composition according to claim 1 or 2, wherein the content of the xylooligosaccharide is 50% by mass or less relative to the composition, and / or the content of the polyethylene is 50% by mass or more relative to the composition.

6. The composition according to claim 1 or 2, wherein the polyethylene is at least one selected from the group consisting of LLDPE (linear low-density polyethylene), LDPE (low-density polyethylene), and HDPE (high-density polyethylene).

7. The composition according to claim 1 or 2, further comprising acid-modified polypropylene.

8. The composition according to claim 7, wherein the content of the acid-modified polypropylene is 0.1 to 20% by mass relative to the composition.

9. A molded article obtained by molding from the composition described in claim 1 or 2.

10. A film molded from the composition described in claim 1 or 2.

11. The film according to claim 10, wherein the arithmetic mean roughness in the flow direction of the film is 0.12 μm or more.

12. The film according to claim 10, wherein the arithmetic mean roughness of the surface of the film is 0.5 μm or more.

13. A film containing polyethylene and xylooligosaccharide, having an arithmetic mean surface roughness in the flow direction of the surface of 0.12 μm or more, and an arithmetic mean surface roughness of 0.5 μm or more.

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