Okara kneaded resin film

Abstract

To provide a film containing a resin mixed with soybean curd refuse, and a packaging bag containing the same.SOLUTION: A film contains a soybean curd refuse-mixed resin which contains, with respect to 100 pts.wt. of a resin having a melt flow rate of approximately 2.0 g / 10 min to approximately 50 g / 10 min, approximately 1 pts.wt. to approximately 105 pts.wt. of soybean curd refuse. The soybean curd refuse-mixed resin further contains approximately 0.5 pts.wt. to approximately 51 pts.wt. of a strength improver. In a different aspect, the strength improver contains inorganic powder and a defoaming agent. In further different aspect, the inorganic powder contains at least one or more selected from calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, barium chloride, calcium nitrate, magnesium nitrate, and barium nitrate.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a okara-kneaded resin film in which okara is kneaded into a resin, and a bag containing the film.

Background Art

[0002] Plastic bags are used for various purposes, including plastic shopping bags and garbage bags.

[0003] In such plastic bags, lubricants such as surfactants and inorganic powders (for example, Patent Document 1 and Patent Document 2) are applied to or kneaded into the bag surface to prevent adhesion and static electricity when thin films overlap. However, when a lubricant is treated on the surface of a plastic bag, the manufacturing process increases, resulting in an increase in production cost, and the lubricant is likely to elute due to heat and moisture. Also, when a lubricant is kneaded into a plastic resin, the moldability as a bag decreases and the yield deteriorates. On the other hand, when an inorganic powder is kneaded, it is indispensable to add a compatibilizer because of its low compatibility with plastic, and it is difficult to prevent the plastic from charging because it is hydrophobic.

[0004] In recent years, however, plastic films kneaded with rice flour have been commercially available (Rice Resin (registered trademark), Biomass Resin Holdings Co., Ltd.). However, since rice flour also has low compatibility with plastic, its moldability is poor, and when the kneading ratio is high, it particularly leads to a decrease in the yield rate and a decrease in strength in the manufacture of bags by inflation molding.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Means for Solving the Problems

[0006] Therefore, the present invention provides the following. (Item 1) A film containing okara-kneaded resin containing okara in a proportion of about 1 part by weight to about 105 parts by weight with respect to 100 parts by weight of a resin having a melt flow rate of about 2.0 g / 10 min to about 50 g / 10 min. (Item 2) The film according to the above item, wherein the okara-kneaded resin further contains a strength improver in a proportion of about 0.5 part by weight to about 51 parts by weight. (Item 3) The film according to any one of the above items, wherein the strength improver contains an inorganic powder and an antifoaming agent. (Item 4) The film according to any one of the above items, wherein the inorganic powder contains at least one or more of calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, barium chloride, calcium nitrate, magnesium nitrate, and barium nitrate. (Item 5) The film according to any one of the above items, wherein the antifoaming agent is selected from the group consisting of silicone resin, glycerin fatty acid ester, sorbitan fatty acid ester, and sucrose fatty acid ester, and wherein the fatty acid contains a saturated or unsaturated fatty acid having about 14 to about 24 carbon atoms including myristic acid, palmitic acid, stearic acid, oleic acid, eicosanoic acid, behenic acid, lignoceric acid, or linoleic acid. (Item 6) The film according to any one of the above items, wherein the resin contains at least one or more of polyethylene, polypropylene, polystyrene, polylactic acid, polybutylene succinate, acrylonitrile-styrene resin, acrylonitrile-styrene-butadiene resin, acrylic resin, polyvinylidene fluoride, polycarbonate, and nitrocellulose. (Item 7) The film according to any one of the above items, characterized in that the melt flow rate is measured in accordance with JIS K6922-2. (Item 8) The film according to any one of the above items, wherein the average particle size of the okara is about 1 μm to about 200 μm. (Item 9) The film according to any one of the above items, wherein the oil content of the okara is about 0.5 wt.% to about 20 wt.%. (Item 10) The film according to any one of the above items, wherein the value obtained by dividing the tear strength (N) of the film at a crosshead speed of 30 mm / min by the thickness (mm) of the film is 30 N / mm or more. (Item 11) The H2O specific surface area of the film is about 1 m 2 / g or more, and the film according to any one of the above items. (Item 12) A packaging bag containing the film according to any one of the above items.

Effect of the Invention

[0007] The okara-kneaded resin film of the present invention has an antistatic effect without any additional treatment due to the high hygroscopicity derived from the characteristics of the okara itself as a raw material. Further, the okara-kneaded resin film of the present invention has fine irregularities on the film surface, reducing the contact area of the film. The combination of the above antistatic effect and the reduced contact area facilitates the handling of the film and improves the mouth-opening property of the bag (evaluated by a blocking index) when formed into a bag. Furthermore, the okara-kneaded resin film of the present invention also has an effect of suppressing bad odor due to the smell of okara.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0009] Embodiments of the present invention will be described below. The embodiments described below describe an example of a preferred embodiment of the invention and do not limit the constituent elements of the present invention described in the claims. Optionally, any weight ratio described in this specification may be based on a weight including moisture or a dry weight basis.

[0010] In one aspect, according to the present invention, there is provided a film containing an okara-kneaded resin containing okara in a ratio of about 1 part by weight to about 105 parts by weight with respect to 100 parts by weight of a resin having a melt flow rate of about 2.0 g / 10 min to about 50 g / 10 min.

[0011] As used herein, the term "about" means encompassing a range of ±10% of the stated value.

[0012] In one embodiment of the present invention, as shown in the following examples, after producing master pellets by heating and melt-kneading okara containing about 10 wt.% of oil and pulverized to an average particle size of 100 μm or less and a thermoplastic plastic at a temperature of 220°C or less, it has been found that by manufacturing a bag by inflation molding, the moldability is good and the mouth-opening property can also be improved. Furthermore, it has also been found that the tear strength can be improved by adding inorganic fillers such as calcium sulfate, magnesium sulfate, barium sulfate, calcium chloride, magnesium chloride, barium chloride, calcium nitrate, magnesium nitrate, and barium nitrate.

[0013] This is considered to be because the adhesion strength between okara and plastic could be improved by kneading the above-mentioned inorganic substances.

[0014] Although not wishing to be bound by a particular theory, the reasons for the good moldability of okara and plastic are: (1) the oil content contained in okara improves the compatibility with the plastic, and (2) the dispersibility is improved by fine pulverization of okara. Also, the reasons for the improvement of the mouth-opening property by kneading okara are: (1) the antistatic effect of polypropylene due to the moisture absorption of okara, and (2) the reduction of the contact surface between the films due to the formation of irregularities on the surface. Furthermore, the reasons for the improvement of the tear strength by adding inorganic fillers are: (1) cross-linking of the soy milk components due to the elution of metal ions and improvement of the adhesion strength between the plastic and okara, and (2) improvement of the elastic modulus accompanying the increase in the crystallinity of the plastic.

[0015] (Properties of the resin and okara to be kneaded) (Material of the resin) The resin kneaded with okara is preferably a resin having a melting point or glass transition temperature of about 220°C or lower. Examples of such resins include polyethylene, polypropylene, polystyrene, polylactic acid, polybutylene succinate, acrylonitrile-styrene resin, acrylonitrile-styrene-butadiene resin, acrylic resin, polyvinylidene fluoride, polycarbonate, nitrocellulose, and the like. In one embodiment, the polystyrene suitable for use in the present invention is preferably of the atactic type. Since the molding temperature of atactic polystyrene is about 200°C, it is suitable for the conditions of heat-melt kneading of the present invention. Atactic polystyrene, acrylic resin, acrylonitrile-styrene-butadiene resin, etc. are amorphous polymer materials and have no melting point. Therefore, these resins are molded at a temperature higher than their glass transition temperature. Polypropylene, acrylic resin, etc. exist in isotactic, syndiotactic, and atactic forms, but all can be molded at 220°C or lower, so they are suitable for the conditions of heat-melt kneading of the present invention.

[0016] Note that the above resins may be mixed in multiple types. In particular, resins with similar solubility parameters (for example, polypropylene and polyethylene, polylactic acid and polybutylene succinate) are preferred because they are easy to mix. Examples of the resin mixture of multiple types in the present invention may include a resin containing polybutylene succinate and polylactic acid, or a resin containing polypropylene and polyethylene. The weight ratio of each resin in the resin mixture of multiple types can be arbitrary. In one embodiment, the resin mixture of multiple types in the present invention may contain polybutylene succinate and polylactic acid, or polypropylene and polyethylene, in a ratio of 99:1 to 1:99. On the other hand, in the case of a resin having a melting point exceeding 220°C, thermal decomposition of okara becomes significant during melt kneading, so it is not suitable (see Figure 2). In this specification, when a resin "contains a certain component as the main component", it means that the weight ratio of the component in the resin is 70% by weight or more.

[0017] For the molten resin to be well molded, the kneaded resin must have a certain degree of fluidity. As an index of such fluidity, there is the "melt flow rate" which measures the amount of resin extruded from the opening at the bottom of a container in 10 minutes after heating and pressurizing the resin placed in a cylindrical extrusion plastometer at a constant temperature. The melt flow rate of the resin of the present invention is about 2.0 g / 10 min to about 50 g / 10 min, preferably about 2.0 g / 10 min to about 40 g / 10 min, more preferably about 2.0 g / 10 min to about 30 g / 10 min, and even more preferably about 2.0 g / 10 min to about 20 g / 10 min when measured by a method conforming to JIS K6922-2 (temperature: 180 °C, load: 2.16 kg).

[0018] (Mixing ratio of okara in kneading) Okara is the residue remaining when soy milk is squeezed out and is generated in large quantities. The mixing ratio of okara in the okara-kneaded resin of the present invention is calculated by the following formula 1. In formula 1, R, W1, and W2 represent the mixing ratio of okara (weight %), the absolute dry weight (kg) of the kneaded okara, and the absolute dry weight (kg) of the resin, respectively.

[0019]

Equation

[0020] In addition, the kneading ratio of okara in the okara-kneaded resin is not particularly limited as long as it can exhibit sufficient hygroscopicity in the okara-kneaded resin film and can improve the mouth-opening property of the bag using the film. For example, it is preferably about 1% by weight or more, about 2% by weight or more, about 3% by weight or more, about 4% by weight or more, about 5% by weight or more, about 6% by weight or more, about 7% by weight or more, about 8% by weight or more, about 9% by weight or more, about 10% by weight or more, about 15% by weight or more, about 20% by weight or more, and most preferably about 10% by weight or more. In this specification, the product obtained after heating and melt-kneading a mixture of okara and resin is referred to as a "kneaded product", the product obtained by cooling the kneaded product is referred to as an "okara-kneaded resin" or a "kneaded resin", and the okara-kneaded resin or kneaded resin cut into pellets is referred to as an "okara-kneaded resin pellet" or a "kneaded resin pellet".

[0021] In one embodiment, the kneading ratio of okara in the okara-kneaded resin can be about 51% by weight or less, preferably about 30% by weight or less. By setting such a ratio, the tear strength of the okara-kneaded resin film can be ensured. The kneading ratio of okara in the okara-kneaded resin of the present invention can be within the numerical range between any one of the lower limit values in the above paragraph and any one of the upper limit values described in this paragraph.

[0022] (Total weight ratio of okara and resin) The present invention provides okara-kneaded resin in which okara and resin do not peel off from each other despite a high total weight ratio of okara and resin, and a method for producing the same. In the production method of the present invention, the total weight ratio of okara and resin in the mixture of okara and resin before heat-melting kneading is about 75% or more, about 80% or more, about 85% or more, about 90% or more, about 95% or more, about 98% or more, about 99% or more, or about 100%. In the present specification, when referring to the "total weight ratio of okara and resin", it may be a value calculated based on the absolute dry weight of each of okara and resin, or a value calculated based on the weight including moisture, but typically it is a value calculated based on the absolute dry weight. The total weight ratio of okara and resin in the mixture of okara and resin before heat-melting kneading is preferably about 90% by weight or more, more preferably about 95% by weight or more, and most preferably about 100%.

[0023] The total weight ratio of okara and resin in the okara-kneaded resin of the present invention is about 75% or more, about 80% or more, about 85% or more, about 90% or more, about 95% or more, about 98% or more, about 99% or more, or 100%. The total weight ratio of okara and resin in the okara-kneaded resin is preferably about 90% by weight or more, more preferably about 95% by weight or more, and most preferably about 100%.

[0024] In one embodiment, in the okara-kneaded resin of the present invention and its production method, an adhesive or compatibilizer for uniformly conforming okara and resin is not used. Examples of general adhesives for uniformly conforming okara and resin include polyvinyl acetate, polyvinyl alcohol, or starch paste. Examples of general compatibilizers for uniformly conforming okara and resin include cellulose esters such as acetyl cellulose, diacetyl cellulose, triacetyl cellulose, nitrocellulose, and sulfuric acid cellulose.

[0025] (Additional components) In one embodiment, the okara-kneaded resin of the present invention may contain additional components in addition to okara and resin. In a typical embodiment, this additional component may include a strength enhancer, a filler for strength reinforcement (organic fillers such as cellulose (e.g., derived from wood waste) or inorganic fillers such as talc and cement-based waste materials), a flame retardant (triphenyl phosphate, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, etc.), a pigment (titanium dioxide, zinc oxide, iron oxide, etc.), a deodorant (activated carbon, coffee grounds, zeolite, etc.), a fragrance, a repellent (e.g., essential oil components of plants such as monoterpenes, sesquiterpenes, phenols, etc.), and the like.

[0026] In one embodiment, the strength enhancer includes an inorganic powder and an antifoaming agent. This inorganic powder contains at least one or more of calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, barium chloride, calcium nitrate, magnesium nitrate, and barium nitrate. Since "nigari" added to soy milk during tofu production already contains magnesium chloride and the like, it is also possible not to add the inorganic powder separately. Examples of the antifoaming agent include silicone resin, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, etc. The fatty acid here is a saturated or unsaturated fatty acid having about 14 to about 24 carbon atoms such as myristic acid, palmitic acid, stearic acid, oleic acid, eicosanoic acid, behenic acid, lignoceric acid, and linoleic acid. Although not wishing to be bound by a particular theory, it is considered that the strength increases by enhancing the dispersibility of the resin with okara and the inorganic powder because the antifoaming agent has a structure relatively close to that of an oil or fat.

[0027] The weight ratio of the additional components in the okara-kneaded resin of the present invention in the okara-kneaded resin is about 34% by weight or less, about 20% by weight or less, about 10% by weight or less, about 5% by weight or less, about 4% by weight or less, about 3% by weight or less, about 2% by weight or less, about 1% by weight or less, about 0.5% by weight or less, about 0.2% by weight or less, 0% by weight (i.e., not contained). In a preferred embodiment, the weight ratio of the additional components in the okara-kneaded resin of the present invention in the okara-kneaded resin is about 10% by weight or less, more preferably about 5% by weight or less.

[0028] The weight ratios of the various components contained in the okara-kneaded resin of the present invention can also be described in parts by weight. In one embodiment, the okara-kneaded resin contains okara in a ratio of about 1 part by weight to about 105 parts by weight with respect to 100 parts by weight of the resin. In another embodiment, the okara-kneaded resin contains okara in a ratio of about 1 part by weight to about 105 parts by weight with respect to 100 parts by weight of the resin, and further contains a strength enhancer in a ratio of about 0.5 part by weight to about 51 parts by weight.

[0029] In the okara-kneaded resin, since the resin solidifies after being melted once, its state changes around the melting point or glass transition temperature. In the okara-kneaded resin, since okara can maintain its shape before and after kneading, it can exist in a particulate form. In the okara-kneaded resin, it is preferable that the resin and okara are uniformly present. For example, when a cube of 8 mm 3 is cut out from the okara-kneaded resin, the weight ratio of okara or resin in any cube can be the same as the weight ratio of okara or resin in the entire okara-kneaded resin, for example, the difference can be within 5%, within 3% or within 1%.

[0030] In this specification, in the okara-kneaded resin, the fact that okara and the resin "do not peel off" means that no peeling marks where the okara has peeled off from the resin are observed in at least about 80% of the area of the surface of the okara-kneaded resin that can be visually observed. In a preferred embodiment, in the okara-kneaded resin of the present invention, no peeling marks where the okara has peeled off from the resin are observed in at least about 90% of the area of the surface of the okara-kneaded resin that can be visually observed. In a more preferred embodiment, no peeling marks where the okara has peeled off from the resin are observed in at least about 95% of the area of the surface of the okara-kneaded resin that can be visually observed. Note that this peeling mark also applies to the okara-kneaded pellets obtained after cutting the kneaded resin. That is, in the okara-kneaded resin pellets of the present invention, okara and the resin do not peel off. In a preferred embodiment, no peeling marks where the okara has peeled off from the resin are observed in at least about 90% of the area of the surface of the okara-kneaded resin pellets that can be visually observed. In a more preferred embodiment, no peeling marks where the okara has peeled off from the resin are observed in at least 95% of the area of the surface of the okara-kneaded resin pellets that can be visually observed. For example, the peeling mark may be a hole formed in the resin or a cavity surrounded by the resin due to the original okara particles falling off from the resin due to peeling. Also, peeling can be characterized by the weak holding force of okara in the kneaded resin. In one embodiment, when the kneaded resin is cut and the newly formed cross-section is subjected to horizontal vibration with an amplitude of 1 cm at 100 rpm for 1 minute with the cross-section facing downwards, the weight of the okara falling per 1 m 2 of the cross-section is about 10 g or less, about 1 g or less, about 0.1 g or less, or about 0.01 g or less, it can also be determined that there is no peeling.

[0031] Okara-kneaded resin pellets obtained from the okara-kneaded resin of the present invention (for example, those obtained by cutting a kneaded resin rod discharged from a discharge port with a diameter of 20 mm at 4 mm intervals using a pelletizer) can have a water vapor adsorption amount of 1 mg or more per 1 g of the kneaded resin pellets when measured using a multi-sample gas adsorption amount measuring device (for example, Autosorb-iQ2-XR-VP manufactured by Anton Paar) at a measurement temperature of 25°C and a relative humidity of 90%. Although not intending to be bound by theory, this is considered to be due to the fact that the kneaded resin pellets are manufactured using only okara and resin without using adhesives, etc., and the substantial amount of okara present.

[0032] (Shape and size of resin) Regarding the shape of the resin to be kneaded with okara, when the resin is originally in the form of a film or sheet such as a packaging film or container, it is finely cut and fed into a kneader. At that time, the size is preferably 0.1 mm square or more and 10 mm square or less, more preferably 3 mm square or more and 9 mm square or less, and most preferably 6 mm square or more and 8 mm square or less. When the size of the resin is smaller than 0.1 mm square, scattering due to static electricity is remarkable and the operability is poor. When the size of the resin is larger than 10 mm square, when the mixture of resin and okara is put into the hopper 3 shown in FIG. 3, there is a concern that the resin will accumulate between the hopper 3 and the screw 4, resulting in a decrease in the uniformity of okara and resin in the okara-kneaded resin.

[0033] Also, when the resin is originally in the form of a film or sheet such as a packaging film or container, the thickness is preferably about 0.01 mm or more and about 10 mm or less, more preferably about 0.05 mm or more and about 2 mm or less, and most preferably about 0.09 mm or more and about 0.12 mm or less. When the thickness of the resin is smaller than about 0.01 mm, scattering due to static electricity is remarkable and the operability is poor. When the thickness of the resin is larger than about 10 mm, the resin accumulates between the hopper 3 and the screw 4 shown in FIG. 3 for the mixture of resin and okara, resulting in a decrease in the uniformity of okara and resin in the okara-kneaded resin.

[0034] When the resin kneaded with okara is in the form of fibers, the thickness and the number of filaments are not particularly limited, but the fiber length is preferably about 1 mm or more and about 10 mm or less, more preferably about 3 mm or more and about 8 mm or less, and most preferably about 4 mm or more and about 6 mm or less. When the fiber length is less than about 1 mm, scattering due to static electricity is remarkable and the operability is poor. When the fiber length is more than about 10 mm, the resin accumulates between the hopper 3 and the screw 4 shown in Fig. 3 in the mixture of the resin and okara, resulting in a decrease in the uniformity of okara and resin in the okara-kneaded resin.

[0035] When the resin kneaded with okara is in the form of granules, the average particle size of the granules is preferably about 1 mm or more and about 10 mm or less, more preferably about 3 mm or more and about 8 mm or less, and most preferably about 4 mm or more and about 6 mm or less. When the average particle size is less than about 1 mm, scattering due to static electricity is remarkable and the operability is poor. When the average particle size is more than about 10 mm, when the mixture of the resin and okara is put into the kneader hopper 3 shown in Fig. 3, the okara does not enter the screw 4, resulting in insufficient mixing with okara and a decrease in the uniformity of okara and resin during kneading.

[0036] (Size of okara) Okara is in the form of powder particles, but at this point, the size of the okara varies. Therefore, it is necessary to grind the okara with a ball mill or the like and control the average particle size of the okara. At this time, the average particle size of the okara to be kneaded with the resin is preferably 1 μm or more and 200 μm or less, more preferably 30 μm or more and 150 μm or less, and most preferably 50 μm or more and 100 μm or less. When the average particle size of the okara is larger than about 200 μm, the resin accumulates between the hopper 3 and the screw 4 described in FIG. 3 in the mixture of the resin and the okara, and as a result, the uniformity of the okara and the resin in the okara-kneaded resin decreases. Also, when it is smaller than about 1 μm, there is a concern that it is likely to scatter and the operability during kneading with the okara decreases. In this specification, when referring to the "average particle size", it is the value obtained by measuring the longest diameter in 20 randomly selected okara particles using a scanning electron microscope and averaging them. For example, the diameter of the okara particles can be measured based on a scale. The size of the okara can also be maintained in the kneaded resin.

[0037] (Water content ratio contained in okara) When the resin and the okara are in a completely dry state, static electricity is likely to be generated due to friction during kneading, and the resin and the okara are likely to scatter. Therefore, by containing an appropriate amount of moisture in the okara, the generation of static electricity is prevented. At this time, the moisture content of the okara is preferably about 1 wt% or more and less than about 20 wt%, more preferably about 5 wt% or more and less than about 15 wt%, and most preferably about 9 wt% or more and less than about 12 wt%. When the moisture content of the okara is less than about 1 wt%, there is a concern that it will scatter during mixing and the variation in the mixing ratio will increase. Also, when the moisture content of the okara is greater than about 20 wt%, the inside of the cylinder 1 is cooled by the heat of vaporization of the moisture during heating, and there is a concern that the resin will not melt sufficiently. In particular, in the case of a resin having an ester bond, there is a concern that the molecular weight will decrease significantly due to hydrolysis. However, when the manufacturing process includes inflation molding, in order to prevent breakage due to bubble formation during inflation molding, the okara to be kneaded needs to be in a completely dry state.

[0038] (Oil content ratio contained in okara) The oil content in okara improves the compatibility with the resin and is essential for uniform kneading. For this reason, the oil content of okara is preferably about 0.5 wt% to about 20 wt%, more preferably about 7 wt% to about 15 wt%, and most preferably about 11 wt% to about 13 wt%. When the oil content of okara is less than 0.5 wt%, the kneading with the resin becomes non-uniform, and there is a concern that the peeling of okara from the okara-kneaded resin becomes remarkable. Also, when the oil content of okara is more than about 20 wt%, there is a concern that the oil bleeds from the okara-kneaded resin, causing corrosion of mechanical devices such as kneaders and injection molding machines.

[0039] Embodiment The production conditions for the kneaded pellets of okara and plastic were based on Japanese Patent Application No. 2021-128389, "Method for Producing Okara-Kneaded Resin" and the production conditions for okara-kneaded resin pellets added with drained okara. Specifically, they are as follows.

[0040] (Outline of Production of Okara-Kneaded Resin Pellets) The method for producing okara-kneaded resin pellets in the present invention includes a step of heating and melt-kneading a mixed resin and okara to produce a kneaded product, and a step of cooling and solidifying the kneaded product (hereinafter, cooling step). In a typical embodiment, the method for producing okara-kneaded resin pellets in the present invention includes a step of mixing resin and okara at an arbitrary ratio (hereinafter, mixing step), a step of melt-kneading the resin and okara mixed in the mixing step using a kneading extruder to produce a kneaded product of okara and resin (hereinafter, kneading step), a step of cooling and solidifying the kneaded product discharged from the kneader (hereinafter, cooling step), and further a step of cutting the cooled kneaded product into pellets (hereinafter, cutting step).

[0041] (Mixing Step) In the mixing process, the resin and okara are mixed at an arbitrary ratio. Typically, the resin and okara are mixed so that the kneading ratio of okara in the above okara-kneaded resin is, for example, 30% by weight or more and 70% by weight or less. The mixing method is not particularly limited. For example, after putting okara and resin into a container such as a stainless-steel cylindrical body at an arbitrary ratio, the container can be covered and manually inverted up and down, or the mixture of resin and okara can be stirred while rotating using a rotary stirrer. At this time, since okara contains an appropriate amount of moisture, the generation of static electricity on the resin surface is prevented, and it is difficult to scatter.

[0042] (Amount of okara and resin charged into the stirring container) When mixing okara and resin, it is preferable to satisfy the following formula (2) among the bulk volume of okara, the bulk volume of resin, and the volume of the stirring container. In formula (2), V1, V2, and V represent the bulk volume of okara (L), the bulk volume of resin (L), and the volume of the stirrer (L), respectively.

[0043]

Number

[0044] Regarding the amounts of okara and resin charged into the stirring container, it is preferable that (V1 + V2) / V is 0.1 or more and 0.8 or less, more preferably 0.3 or more and 0.6 or less, and most preferably 0.4 or more and 0.5 or less. When the value of formula (2) is less than 0.1, the loss ratio due to adhesion to the inner wall of the stirring container, etc. increases, and when it is greater than 0.8, there is a concern that okara and resin may not be stirred and the mixing may be insufficient. Actually, when (V1 + V2) / V falls within 0.1 or more and 0.8 or less as compared with the case where (V1 + V2) / V exceeds 0.8 and reaches 1.0, both the appearance evaluation and the water vapor adsorption amount of the obtained okara-kneaded resin pellets were excellent (data not shown).

[0045] (Rotation speed of the stirrer during rotary stirring) When mixing okara and resin by rotary stirring, the rotational speed of the stirrer can be any numerical value as long as the okara and resin are moderately stirred. However, it is preferably 1 rpm or more and 30 rpm or less, more preferably 5 rpm or more and 20 rpm, and most preferably 12 rpm or more and 15 rpm or less. If the rotational speed is less than 1 rpm, there is a concern that the okara and resin will not be sufficiently stirred. If the rotational speed is higher than 30 rpm, there is no significant difference in the degree of mixing, and the technical significance becomes negligible.

[0046] (Kneading step) The mixture of okara and resin produced in the mixing step is heated and melt-kneaded. In an exemplary embodiment of the present invention, the mixture of okara and resin is introduced from the kneader hopper 3 schematically shown in FIG. 3. Inside the cylinder 1, a screw 4 having a spiral groove rotates, and the melted resin and okara are discharged from the discharge port 5 in a mixed state. At this time, the oil content contained in the okara prevents phase separation between the resin and the okara, and uniform kneading is achieved. Usually, when kneading a food biomass or an inorganic filler with low compatibility with the resin, a compatibilizer or the like is added to improve uniformity. However, since the okara used in the present invention contains oil, uniform kneading is possible without adding a compatibilizer.

[0047] (Kneading temperature) In an exemplary embodiment, a heater 6 is installed inside a cylinder 1 of a kneader for producing okara-kneaded resin of the present invention, and the kneading temperature can be arbitrarily controlled by a temperature control unit 7. When kneading okara and resin, in the case of low-density polyethylene, polystyrene, polybutylene succinate, acrylonitrile-styrene resin, acrylonitrile-styrene-butadiene resin, and acrylic resin, a temperature of 130°C or higher and 220°C or lower is preferable, a temperature of 150°C or higher and 180°C or lower is more preferable, and a temperature of 155°C or higher and 175°C or lower is most preferable. In the case of high-density polyethylene, polypropylene, polylactic acid, polyvinylidene fluoride, polycarbonate, and nitrocellulose, the above temperature is preferably 170°C or higher and 220°C or lower, more preferably 175°C or higher and 200°C or lower, and most preferably 180°C or higher and 195°C or lower. Note that the "kneading temperature" in this specification refers to the temperature at the hottest location in the cylinder 1. When the kneading temperature is less than 130°C (low-density polyethylene, polystyrene, polybutylene succinate, acrylonitrile-styrene resin, acrylonitrile-styrene-butadiene resin, acrylic resin) or less than 170°C (high-density polyethylene, polypropylene, polylactic acid, polyvinylidene fluoride, polycarbonate, nitrocellulose), the resin does not melt sufficiently, resulting in frequent breakage during molding. On the other hand, when the kneading temperature is higher than 220°C, thermal decomposition of okara becomes significant, and there is a concern of frequent formation of bubbles and breakage due to the decomposition-generated gas. In a preferred embodiment, the kneading process can be performed such that the molecular weight of the resin after kneading increases compared to the molecular weight of the resin before kneading.

[0048] (Material of the cylinder) The material of the cylinder 1 is not particularly limited, but since resin and okara containing moisture come into contact with it in the same way as the screw, it is preferable to use a material such as stainless steel or cermet. In addition, it is also preferable to improve the corrosion resistance by performing surface treatment such as chrome plating.

[0049] (Screw rotation speed) In the kneading process, the rotational speed of the screw 4 is preferably 40 rpm or more and 120 rpm or less, more preferably 55 rpm or more and 100 rpm or less, and most preferably 60 rpm or more and 80 rpm or less. When the rotational speed of the screw 4 is less than 40 rpm, there is a concern that the time for the resin and okara to receive heat becomes long, and thermal decomposition and hydrolysis are likely to occur. When it is more than 120 rpm, there is a concern that the melting of the resin becomes insufficient and it cannot be kneaded with okara. Actually, compared with the case where the rotational speed of the screw is 200 rpm, when the rotational speed is 50 rpm or more and 120 rpm or less, both the appearance evaluation of the obtained okara-kneaded resin pellets and the water vapor adsorption amount were excellent (data not shown).

[0050] (Material of the screw) The material of the screw 4 is not particularly limited, but since okara containing moisture is introduced, it is preferable to use stainless steel or cermet for the material of the screw 4. In addition, it is also preferable to improve the corrosion resistance by performing surface treatment such as chromium plating.

[0051] (Automatic exhaust valve) In a preferred embodiment, in the kneader used for the heat melting and kneading in the production of the okara-kneaded resin of the present invention, an automatic exhaust valve 2 is installed in the cylinder to prevent the internal pressure in the cylinder from rising due to the evaporation of the moisture contained in the okara. At this time, the automatic exhaust valve 2 is preferably set so that it can automatically release water vapor into the atmosphere when the inside of the cylinder reaches 0.05 MPa.G or more.

[0052] (Diameter of the discharge port) The shape of the discharge port 5 is not particularly limited, but a circular shape is most preferable. When the shape of the discharge port 5 is circular, the diameter of the discharge port 5 is preferably 1 mm or more and less than 10 mm, more preferably 2 mm or more and 6 mm or less, and most preferably 4 mm or more and less than 5 mm. When the diameter of the discharge port 5 is less than 1 mm, the discharged okara-kneaded resin 8 is likely to be cut. When it is thicker than 10 mm, the okara-kneaded resin 8 is likely to be cut, and there is a concern that the operability of the subsequent cooling process and cutting process will decrease.

[0053] (Cooling process) In the kneading process, the rod-shaped okara-kneaded resin 8 is discharged from the discharge port 5. Immediately after the discharge, the okara-kneaded resin 8 is transferred to the pelletizer, but a process (cooling process) for cooling and solidifying the okara-kneaded resin 8 is required in the previous stage thereof.

[0054] (Cooling method) As the cooling method of the okara-kneaded resin 8 in the cooling process, a method of blowing air using a blower or the like to the okara-kneaded resin 8 (hereinafter, air-cooling method), a method of impregnating the okara-kneaded resin 8 in water (hereinafter, water-cooling method), and a method of bringing it into contact with a cooling block (hereinafter, cooling block contact method) are preferable, the air-cooling method and the cooling block contact method are more preferable, and the air-cooling method is most preferable. This is because the okara-kneaded resin 8 can be cooled by air-cooling and it is difficult for moisture to adhere to the okara.

[0055] (Cooling distance) In the cooling process, when cooling the rod-shaped okara-kneaded resin 8 discharged from the kneader, the distance from the discharge port 5 to the pelletizer 9 (hereinafter, cooling distance) is preferably 1 m or more and 10 m or less, more preferably 2 m or more and 6 m or less, and most preferably 3 m or more and 5 m or less. When the cooling distance is less than 1 m, there is a concern that the cooling of the okara-kneaded resin becomes insufficient and subsequent cutting becomes difficult. Also, when the cooling distance is longer than 10 m, the okara-kneaded resin is sufficiently solidified by any cooling method and the technical significance becomes diluted. Actually, compared with the case where the cooling distance is 0.3 m, when the cooling distance is 1 m or more, both the appearance evaluation of the obtained okara-kneaded resin pellets and the water vapor adsorption amount were excellent (data not shown).

[0056] (Cooling of okara-kneaded resin by air-cooling method) Fig. 4 schematically shows the flow of the kneading process, the cooling process by the air-cooling method, and the cutting process. When cooling the okara-kneaded resin 8 by the air-cooling method, the okara-kneaded resin 8 moves on a feed table 10 installed between the kneader and the pelletizer 9. At this time, air is sent from the blower 11 to the surface of the okara-kneaded resin 8. The wind speed on the surface of the okara-kneaded resin 8 is preferably 1.5 m / s or more and 10 m / s or less, more preferably 3 m / s or more and 7 m / s or less, and most preferably 4 m / s or more and 5 m / s or less. When the wind speed on the surface of the okara-kneaded resin 8 is less than 1.5 m / s, the cooling of the kneaded product is insufficient, making subsequent cutting difficult. When it is greater than 10 m / s, there is a concern that the rod-shaped okara-kneaded resin 8 may be cut due to the wind pressure.

[0057] (Cooling of Okara-Kneaded Resin by Cooling Block Contact Method) Fig. 5 schematically shows the flow of the kneading process, the cooling process by the cooling block contact method, and the cutting process. When cooling the okara-kneaded resin 8 by the cooling block contact method, the temperature of the cooling block 12 is preferably -20°C or more and 10°C or less, more preferably -5°C or more and 5°C or less, and most preferably 0°C or more and 3°C or less. Even if the temperature of the cooling block 12 is less than -20°C, there is no difference in the cooling degree of the kneaded product, and the technical significance becomes negligible. When it is higher than 10°C, there is a concern that the cooling of the kneaded product is insufficient, making subsequent cutting difficult.

[0058] (Cooling of Okara-Kneaded Resin by Water-Cooling Method) Fig. 6 schematically shows the flow of the kneading process, the cooling process by the water-cooling method, and the cutting process. In the case of the water-cooling method, the okara-kneaded resin 8 is cooled by passing through the water tank 13. At this time, the water temperature in the water tank 13 is preferably 0°C or more and 10°C or less, more preferably 2°C or more and 7°C or less, and most preferably 4°C or more and 6°C or less. When the water temperature in the water tank 13 is less than 0°C, the water in the water tank 13 freezes, and the okara-kneaded resin 8 cannot be immersed. When it is higher than 10°C, there is a concern that the cooling of the okara-kneaded resin 8 is insufficient, making subsequent cutting difficult. Note that when cooling by the water-cooling method, it is necessary to perform a drying process again after the cutting process to remove moisture.

[0059] (Cutting Process) The cooled rod-shaped okara-kneaded resin 8 is cut into any size in the cutting process using a pelletizer 9. At this time, the cutting method is not particularly limited, but the pelletizer preferably uses a strand cut method that cuts with a rotating blade and a fixed blade in practical use. In a preferred embodiment, the okara-kneaded resin of the present invention, or the okara-kneaded resin produced by the production method of the present invention, has okara and resin not peeled off even after cutting.

[0060] (Cutting Interval of Okara-Kneaded Resin) When cutting the rod-shaped okara-kneaded resin 8 sent from the kneader with the pelletizer 9, the cutting interval is preferably 1 mm or more and 10 mm or less, more preferably 3 mm or more and 8 mm or less, and most preferably 4 mm or more and 5 mm or less. This is because when the cutting interval is less than 1 mm, the okara kneaded in the okara-kneaded resin 8 is likely to peel off, and when it is longer than 10 mm, there is a concern that it is too large to be handled as a moisture-absorbing material.

[0061] (Materials of the Rotating Blade and Fixed Blade of the Pelletizer) Fig. 7 schematically shows the structure inside the pelletizer 9. Inside the pelletizer 9, a rotating blade 14 and a fixed blade 15 are installed. The materials of the rotating blade 14 and the fixed blade 15 are not particularly limited, but since okara contains oil, it is desirable to use materials with excellent corrosion resistance such as stainless steel or cermet, or to perform surface treatment such as chrome plating.

[0062] (Recovery of Okara-Kneaded Resin Pellets and Subsequent Molding) The okara-kneaded resin 8 is cut by the rotating blade 14 and the fixed blade 15 inside the pelletizer 9, and the okara-kneaded resin pellets 16 are accumulated in a container 17 installed at the lower part of the pelletizer. The okara-kneaded resin material pellets thus obtained can be molded into molded products of any shape by molding methods such as injection molding and extrusion molding in addition to their use as moisture-absorbing materials. In this specification, an article obtained by processing using kneaded resin or kneaded resin pellets as a material or part of a material is called a molded product.

[0063] (Molding of Okara-Kneaded Resin Film) Examples of the method for producing an okara-kneaded resin film include T-die molding, inflation molding, calendar molding, skyf molding, etc. In particular, inflation molding is preferred.

[0064] (Inflation Molding of Okara-Kneaded Resin Film) The inflation molding of the okara-kneaded resin film of the present invention can be carried out according to a conventional method. For example, it can be carried out using an inflation molding machine at a cylinder temperature of 130°C or higher and 220°C or lower, and a die temperature of 130°C or higher and 220°C or lower. Also, the blow-up ratio (fold diameter / die diameter) may be 1 or more and 5 or less, the film thickness may be 0.01 mm or more and 1 mm or less, the fold diameter may be 200 mm or more and 600 mm or less, and the molding speed may be 0.5 m / min or more and 10 m / min or less.

[0065] Conditions for Inflation Molding The cylinder temperature of the extruder and the temperature of the die part are preferably 130°C or higher and 220°C or lower, more preferably 150°C or higher and 180°C or lower, and most preferably 155°C or higher and 175°C or lower in the case of low-density polyethylene, polystyrene, polybutylene succinate, acrylonitrile-styrene resin, acrylonitrile-styrene-butadiene resin, and acrylic resin. If the temperature is lower than 130°C, there is a concern that the resin may not melt sufficiently, resulting in frequent breakage during molding. Also, if the temperature is higher than 220°C, the thermal decomposition of okara becomes significant, and there is a concern that bubble formation and breakage may occur frequently due to the decomposition product gas. In the case of high-density polyethylene, polypropylene, polylactic acid, polyvinylidene fluoride, polycarbonate, and nitrocellulose, the above temperature is preferably 170°C or higher and 220°C or lower, more preferably 175°C or higher and 200°C or lower, and most preferably 180°C or higher and 195°C or lower. If the temperature is lower than 170°C, there is a concern that the resin may not melt sufficiently, resulting in frequent breakage during molding. Also, if the temperature is higher than 220°C, the thermal decomposition of okara becomes significant, and there is a concern that bubble formation and breakage may occur frequently due to the decomposition product gas.

[0066] The extrusion machine screw rotation speed is preferably 40 rpm or more and 120 rpm or less, more preferably 55 rpm or more and 100 rpm or less, and most preferably 60 rpm or more and 80 rpm or less. When the screw rotation speed is less than 40 rpm, there is a concern that the resin and okara will be exposed to heat for a long time, increasing the likelihood of thermal decomposition and hydrolysis. When it is greater than 120 rpm, there is a concern that the melting of the resin will be insufficient and it will not be possible to knead with okara.

[0067] The die lip clearance (the width of the part where the resin comes out from the annular die) is preferably 0.5 mm or more and 1.5 mm or less, more preferably 0.6 mm or more and 1 mm or less, and most preferably 0.7 mm or more and 0.8 mm or less. When the die lip clearance is less than 0.5 mm, there is a concern that the formed film will be easily broken. When it is greater than 1.5 mm, there is a concern that the thickness deviation will be large during inflation molding and the dimensional stability of the film will also be low.

[0068] The blow-up ratio is preferably 1 or more and 5 or less, more preferably 2 or more and 4 or less, and most preferably 2.2 or more and 2.8 or less. When the blow-up ratio is less than 1, there is a concern that the film thickness will not be stable. When it is greater than 5, there is a concern that the film will frequently break.

[0069] The forming speed of the okara-kneaded resin film is preferably 0.5 m / min or more and 10 m / min or less, more preferably 1.0 m / min or more and 5 m / min or less, and most preferably 1.2 m / min or more and 2.0 m / min or less. When the forming speed is less than 0.5 m / min, there is a concern that the film thickness will not be stable. When it is greater than 10 m / min, there is a concern that the stretching effect will be large and the film will frequently break.

[0070] (Properties of the okara-kneaded resin film) The okara-kneaded resin film of the present invention has an antistatic effect without any additional treatment due to its high hygroscopicity derived from the characteristics of okara itself as a raw material. Also, the okara-kneaded resin film of the present invention has fine irregularities on the film surface, reducing the contact area of the film. The combination of the above antistatic effect and the reduced contact area facilitates the handling of the film and improves the mouth-opening property of the bag (evaluated by the blocking index) when formed into a bag. Furthermore, the okara-kneaded resin film of the present invention also has an effect of suppressing bad odors due to the smell of okara. Also, as described in Japanese Patent Application No. 2021-128396 "Seedling-raising pot", the okara-kneaded resin film can be made biodegradable by using as the main component of the resin a material selected from polypropylene, polyethylene, polylactic acid, polybutylene succinate, etc.

[0071] The okara-kneaded resin film of the present invention can be formed into any dimensions and shapes according to the performance of the inflation molding machine. The thickness can be in any range, such as about 10 μm to about 1000 μm, but the yield decreases as the average particle size of okara increases relative to the film thickness. For example, when forming to a thickness of about 10 μm to 15 μm, the average particle size of okara needs to be about 50 μm or less, and when forming to a thickness of 30 μm, the average particle size of okara needs to be about 100 μm or less.

[0072] (Uses of the okara-kneaded resin film) The okara-kneaded resin film of the present invention has various uses by utilizing its characteristics. For example, as uses in the form of a sheet, there are packaging sheets, shrink films, packing sheets, foamed sheets, curing sheets, or agricultural sheets (e.g., biodegradable mulch), etc. In particular, the biodegradable okara-kneaded resin film, as described in Japanese Patent Application No. 2021-128396 "Seedling-raising pot", elutes minerals (especially potassium) contained in okara, and when used as an agricultural sheet, it does not need to be removed, and an additional fertilizing effect can also be expected. Furthermore, since the okara contained in the kneaded resin film maintains water absorption, if the film is impregnated with a commercially available liquid fertilizer and then dried, an even higher fertilizing effect can be expected. In another aspect, it is also assumed that by laminating a plurality of sheets, the strength of the entire sheet can be improved.

[0073] As uses of the okara-kneaded resin film of the present invention as a bag, there are packaging bags, garbage bags, bags for disposing of odor-emitting items (such as food waste, used diapers, etc.), or compost bags. In particular, the present invention has extremely high industrial applicability in terms of achieving both cost considerations and environmental considerations, in that it can manufacture bags having improved opening properties and deodorizing effects from industrial waste such as waste plastics and okara as described in this specification.

Examples

[0074] An example of the manufacturing method of the okara-kneaded resin film of the present invention is described below. It should be noted that the following examples are merely illustrative, and the present invention is not limited to the following examples.

[0075] (Preparation of okara-kneaded resin film (Example 1)) (Preparation of okara-kneaded plastic pellets (master pellets)) For the plastic, low-density polyethylene (hereinafter referred to as LDPE) with a melt flow rate of 4.0 g / 10 min was used. Also, for okara, the raw okara remaining after squeezing soy milk was dried and then crushed to an average particle size of 80 μm. The oil content in the okara was 17.6 wt.%.

[0076] Fig. 8 shows the extrusion kneader (hereinafter referred to as the kneader) used for producing okara-kneaded PE pellets. LDPE and okara were respectively charged into the resin introduction hopper and the okara introduction hopper, and introduced into the cylinder so that the weight ratio of LDPE to okara was 98:2. Also, the screw diameter of the kneader was 26 mm, the screw rotation speed was 65 rpm, and the temperatures of the heaters (C1, C2, C3, and C4) of the cylinder and the nozzle part (N) were 150 °C, 170 °C, 175 °C, 180 °C, and 175 °C, respectively. Then, the rod-shaped kneaded product of okara and LDPE coming out from the tip of the nozzle was introduced into the pelletizer using a pulling device and cut at 3 mm intervals. In this way, okara 2 wt.% kneaded PE pellets were obtained.

[0077] (Inflation molding) An annular die with a die lip diameter of 25 mmφ and a die lip clearance (width of the part where the resin comes out from the annular die) of 0.75 mm was attached to a single-screw extruder with a cylinder diameter of 25 mmφ (screw compression ratio = 2.8, cylinder length / cylinder diameter = 25). Through a 100-mesh screen, the screw rotation speed of the extruder was set to 61.9 rpm, the molding temperature (resin temperature at the die outlet) from the annular die was set to 160 °C, and melt extrusion was performed at a molding speed of 1.4 m / min and a discharge rate of 588 g / min. While blowing air from an air ring with an outer diameter of 60 mmφ provided about 30 mm above the die outlet, inflation molding was performed so that the blow-up ratio was 2.5 and the take-up speed was 25 m / min. An okara-kneaded resin film (Example 1) with a thickness of 0.6 mm and a folding diameter of 360 mm was produced through a nip roll, a guide roll, and a second nip roll located about 1000 mm above the die outlet.

[0078] Using the same procedure as above, okara-kneaded resin films (Examples 2 to 16) and Comparative Examples 1 to 5 were prepared by kneading okara at 4 wt.% to 20 wt.%. When combining a third component such as calcium sulfate (CaSO4), magnesium chloride (MgCl2), calcium chloride (CaCl2), calcium nitrate (Ca(NO3)2), magnesium nitrate (Ca(NO3)2), calcium carbonate (CaCO3), or calcium hydroxide (Ca(OH)2), during the production of the master pellet, okara and the third component were mixed at an arbitrary ratio and introduced from the okara introduction hopper.

[0079] The physical properties of the bag made of the okara-kneaded resin film produced according to the present invention are shown below.

[0080] Evaluation method of okara-kneaded bag Evaluation of opening property (blocking index) The following judgment criteria were set, and it was judged that the opening property was improved when it was 3 or more.

Table 1

[0081] Tear test As shown in Fig. 9, the sample was cut into a size of 20 mm × 50 mm, a 25-mm cut was made at the center of the short side, and then it was pulled using a material testing machine at a crosshead speed of 30 mm / min. Furthermore, the value obtained by dividing the tear strength by the thickness of the sample was evaluated as the tear strength index.

[0082] When the tear strength index was 30 or more, it was judged that the strength required for use as a bag was maintained.

[0083] Measurement of water vapor adsorption isotherm Using a multi-sample gas adsorption measurement device (Anton Paar, Autosorb-iQ2-XR-VP), after vacuum heating and evacuation at 40 °C for 24 hours in advance, the water vapor adsorption amount was measured every 0.05 in the range of adsorption temperature of 25 °C and relative pressure of 0 to 0.9. Also, the specific surface area (hereinafter referred to as the H2O specific surface area) was calculated by the BET three-point method from the water vapor adsorption amounts at relative pressures of 0.20, 0.25, and 0.30. The occupied area of water vapor was 0.112 nm 2 was used.

[0084] The evaluation items were the H2O specific surface area and the water vapor adsorption amount (mg H2O / g) at 90% R.H. When they were 1 m 2 / g and 1 mg H2O / g or more, respectively, it was judged that there was an antistatic effect due to moisture absorption.

[0085] Deodorization test Procedure (1) The bag-shaped samples obtained in each example and comparative example were laminated and fused as shown in Fig. 10, and after further attaching a cock for gas evacuation and introduction, 1 L of a mixed gas of air and ammonia was put into the sample bag. At this time, the ammonia gas concentration was 100 ppm. (2) After leaving it for 10 minutes, the face of the subject was brought close to a height of 15 cm directly above the bag-shaped sample containing the mixed gas, and it was confirmed whether the ammonia odor could be distinguished. (3) Based on Table 2, the deodorization effect by okara kneading was evaluated.

Table 2

[0086] Results The results of the examples and comparative examples tested according to the above evaluation method of the okara kneading bag are shown in Table 3 below.

Table 3

[0087] The okara-kneaded resin film of the present invention has a kneading ratio of okara of 2% to 20% by weight, a tear strength index of 30 or more, and an H2O specific surface area of 1 m 2 / g or more and a water vapor adsorption amount at 90% R.H. of 1 mg H2O / g or more, and it has been demonstrated that it exhibits desired properties. Further, as is clear from Examples 8 to 16, when calcium sulfate (CaSO4), magnesium chloride (MgCl2), calcium chloride (CaCl2), calcium nitrate (Ca(NO3)2), magnesium nitrate (Ca(NO3)2), or a combination thereof is added as the inorganic powder, it has been shown that the tear strength index increases as compared with the case where these are not added. Also, the okara-kneaded resin films (Examples 1 to 16) of the present invention were also found to have a blocking index and a deodorizing effect suitable for use as a bag. When the kneading ratio of okara and its H2O specific surface area of the okara-kneaded resin films (Examples 1 to 16) of the present invention were plotted, it was found that there is a linear relationship between them (Figure 11).

[0088] On the other hand, when calcium carbonate (CaCO3) or calcium hydroxide (Ca(OH)2) was used as the inorganic powder (Comparative Examples 2 and 3), sufficient tear strength was not shown (25 N / mm and 29 N / mm, respectively), and it was judged to be unsuitable as a product. When the kneading ratio of okara was too high (30% by weight) (Comparative Example 4) or when the average particle size of okara was too large (229 μm) (Comparative Example 5), sufficient tear strength was not shown either.

Industrial Applicability

[0089] The okara-kneaded resin film of the present invention can impart an antistatic effect, a malodor suppressing effect, and an improvement in the mouth-opening property of the bag to the film, and thus can be applied in all fields using films and packaging bags.

Explanation of Signs

[0090] 1 Kneading Machine Cylinder 2 Automatic Exhaust Valve 3 Hopper 4 Screw 5 Outlet 6a, 6b, 6c, 6n Heater 7 Control unit 8 Rod-shaped okara kneaded resin 9 Pelletizer 10 Feed table 11 Blower 12 Cooling block 13 Water tank 14 Rotary blade 15 Fixed blade 16 Okara kneaded resin pellets 17 Container

Claims

1. A film containing okara-kneaded resin, wherein the okara-kneaded resin contains okara in a proportion of about 1 part by weight to about 20 parts by weight with respect to 100 parts by weight of a resin having a melt flow rate of about 2.0 g / 10 min to about 50 g / 10 min, the resin contains at least one of polyethylene, polypropylene, and polystyrene, the average particle size of the okara is about 1 μm to about 100 μm, the thickness of the film is 0.01 mm to 0.6 mm, and the okara-kneaded resin is (a) composed of the okara and the resin, or (b) contains the okara, the resin, and a strength improver in a proportion of about 0.5 part by weight to about 51 parts by weight, the strength improver contains inorganic powder and an antifoaming agent, the inorganic powder contains at least one of calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, barium chloride, calcium nitrate, magnesium nitrate, and barium nitrate, The film, wherein the melt flow rate is measured in accordance with JIS K6922-2.

2. The antifoaming agent is selected from the group consisting of silicone resin, glycerin fatty acid ester, sorbitan fatty acid ester, and sucrose fatty acid ester, wherein the fatty acid is a saturated or unsaturated fatty acid having about 14 to about 24 carbon atoms including myristic acid, palmitic acid, stearic acid, oleic acid, eicosanoic acid, behenic acid, lignoceric acid, or linoleic acid. The film according to claim 1.

3. The oil content of the okara is about 0.5 wt.% to about 20 wt.%. The film according to claim 1.

4. The value obtained by dividing the tear strength (N) of the film at a crosshead speed of 30 mm / min by the thickness (mm) of the film is 30 N / mm or more. The film according to claim 1.

5. The H ２ O specific surface area of the film is about 1 m ２The film according to claim 1, which is 0 / g or more.

6. A packaging bag containing the film according to claim 1.

7. The film according to claim 1, wherein the film is manufactured by inflation molding.

Images