Styrene resin composition, molded articles, films, sheets, and foams thereof, and methods for producing the same.

Abstract

It was unclear whether a styrene-based resin composition containing biomass could be produced under temperature conditions above the melting point of the resin. [Solution] The object of the present invention is to provide a method for producing a styrene resin composition, comprising the steps of mixing a styrene resin (A), biomass (B), and a zinc-based deodorant (C) under specific temperature conditions, wherein the specific temperature is 165°C or higher and 200°C or lower.

Description

[Technical Field]

[0001] The present invention relates to a styrenic resin composition and a method for producing the same, and particularly to a styrenic resin composition comprising a styrenic resin (A), biomass (B) and a zinc-based deodorant (C), a method for producing the same, and a molded article, a film and a foam obtained from the styrenic resin composition. [Background Art]

[0002] Conventionally, polystyrene resins have been used in a wide range of applications such as packaging materials and containers because of their excellent transparency and moldability. In recent years, technologies for compounding plant-derived biomass into polystyrene resins have attracted attention for reducing the use of petroleum-derived resources and achieving carbon neutrality. It is expected that this can reduce petroleum consumption and suppress total CO₂ emissions.

[0003] However, biomass contains components such as cellulose and protein, and there is a problem that these components are easily deteriorated under the high-temperature environment during resin processing. It has been pointed out that this deterioration may generate odor during processing or cause the molded article itself to have an odor, which adversely affects the quality of the final product.

[0004] Patent Document 1 discloses a technique for suitably removing volatile components that cause burnt odor by heating at a temperature at which the volatile components causing burnt odor in woody materials can volatilize and lower than the melting point of the resin. [Prior Art Literature] [Patent Literature]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 2017-109343 [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] However, the technology disclosed in Patent Document 1 involves heating the resin at a temperature below its melting point. Therefore, it is not possible to melt the styrene resin when manufacturing a styrene resin composition, and thus it is not possible to manufacture a styrene resin composition containing biomass while suppressing the odor derived from biomass. [Means for solving the problem]

[0007] The inventors have demonstrated that, even at temperatures above the melting point of styrene and within a specific temperature range, an environmentally friendly polystyrene resin with low odor can be produced by using specific additives in a biomass composite resin, thus completing the present invention.

[0008] [1] The objective of the present invention is, The process includes a step of mixing a styrene-based resin (A), biomass (B), and a zinc-based deodorant (C) under specific temperature conditions. The specified temperature range is between 165°C and 200°C. Method for producing styrene-based resin compositions The objective is to provide.

[0009] By using the manufacturing method according to the present invention, an environmentally friendly styrene-based resin composition with low odor can be produced from a biomass composite resin.

[0010] [2] In the manufacturing method described in [1], The above zinc-based deodorant (C) may be zinc oxide and / or zinc stearate.

[0011] [3] In the manufacturing method described in [1], The above biomass (B) may also be solid food residue.

[0012] [4] In the manufacturing method described in [3], The solid food residue mentioned above may also be plant-based.

[0013] [5] In the production method according to any one of [1] to [4], when the total amount of the styrenic resin (A) and the biomass (B) is 100 parts by mass, the content of the biomass (B) may be 1 to 90 parts by mass, the content of the zinc-based deodorant (C) may be 1 part by mass or more based on 100 parts by mass of the biomass (B).

[0014] [6] Another object of the present invention is to a styrenic resin (A), biomass (B), a zinc-based deodorant (C), a styrenic resin composition comprising to be provided.

[0015] The styrenic resin composition according to the present invention, which contains biomass and has low odor, is an environmentally friendly styrenic resin composition. [7] In the styrenic resin composition according to [6], the zinc-based deodorant (C) may be zinc oxide and / or zinc stearate.

[0016] [8] In the styrenic resin composition according to [6], the biomass (B) may be a solid food residue.

[0017] [9] In the styrenic resin composition according to [8], the solid food residue may be vegetable-based.

[0018]

[10] In the styrenic resin composition according to [6], when the total amount of the styrenic resin (A) and the biomass (B) is 100 parts by mass, the content of the biomass (B) may be 1 to 90 parts by mass, The amount of the zinc-based deodorant (C) may be 1 part by mass or more per 100 parts by mass of the biomass (B).

[0019]

[11] A molded article obtained by molding a styrene-based resin composition according to any one of items [6] to

[10] .

[0020]

[12] A film comprising the styrene resin composition described in any one of items [6] to

[10] .

[0021]

[13] A sheet comprising the styrene resin composition described in any one of items [6] to

[10] .

[0022]

[14] A foam comprising a styrene-based resin composition as described in any one of items [6] to

[10] . [Modes for carrying out the invention]

[0023] definition For convenience, the specific terms used in this application are gathered here. Unless otherwise specified, all technical and scientific terms used in this application have the same meaning as those generally understood by those skilled in the art to which this invention pertains. Unless otherwise specified in the context, the singular forms "a," "an," and "the" include plural references.

[0024] The numerical ranges and parameters shown in this invention are approximations, although the numerical values ​​shown in specific examples are described as accurately as possible. However, all numerical values ​​inherently contain certain errors that inevitably arise from the standard deviation observed in each test measurement. Furthermore, the term "about" as used herein generally means within 10%, 5%, 1%, or 0.5% of a given value or range. Alternatively, the term "about" means that it is within an acceptable standard error, as considered by those skilled in the art.

[0025] The embodiments of the present invention will now be described. The following embodiments are illustrative, and the scope of the present invention is not limited to those shown in the following embodiments. In order to avoid repetition and complexity, explanations of similar content will be omitted as appropriate.

[0026] <Styrene-based resin composition and method for producing the same> The styrene-based resin composition according to this embodiment comprises a styrene-based resin (A), biomass (B), and a zinc-based deodorant (C).

[0027] <Styrene-based resin (A)> The styrene resin (A) is obtained by radical polymerization of an aromatic vinyl compound monomer (a1), and may be a rubber-modified rubber-containing styrene resin obtained by adding a rubber polymer such as a conjugated diene rubber polymer as needed. It can be produced by known polymerization methods, such as bulk polymerization, bulk-suspension two-stage polymerization, and solution polymerization. The aromatic vinyl compound monomer is a monocyclic or polycyclic aromatic vinyl monomer, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenylbencene (α-methylstyrene), isopropenyltoluene, isopropenylethylbenzene, isoprop The monomers are penylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, etc., either alone or in mixtures of two or more. Preferably, the monomers are styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, either alone or in mixtures of two or more. More preferably, the monomer is styrene. Monomers copolymerizable with these aromatic vinyl compound monomers, such as acrylonitrile, (meth)acrylic acid, and (meth)acrylic acid esters, may also be included to the extent that they do not impair the performance of the styrene-based resin composition. Furthermore, in the present invention, a crosslinking agent such as divinylbenzene may be added to the styrene-based monomer and polymerized. In addition, it may be mixed with other styrene-based resins as needed.

[0028] Examples of conjugated diene rubber-like polymers used for rubber modification of the styrene-based resin (A) of the present invention include polybutadiene, random or block copolymers of styrene-butadiene, polyisoprene, polychloroprene, random, block or graft copolymers of styrene-isoprene, ethylene-propylene rubber, and ethylene-propylene-diene rubber, but polybutadiene and random, block or graft copolymers of styrene-butadiene are particularly preferred. These may also be partially hydrogenated and may be used individually or in combination of two or more types.

[0029] In this embodiment, the content of the rubbery polymer in 100 parts by mass of styrene resin (A) is preferably 1.0 to 30.0 parts by mass, and more preferably 2.0 to 25.0 parts by mass, from the viewpoint of strength and rigidity. This range of rubbery polymer content is preferable because it provides a good balance between impact strength and rigidity. The content of the rubbery polymer may be within any two of the following ranges: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0, 25.0, 26.0, 27.0, 28.0, 29.0, and 30.0 parts by mass. When rubbery polymers are used in combination, the amount of rubbery polymers used refers to the total amount of rubbery polymers used in combination.

[0030] The content of the rubbery polymer can be measured, for example, as follows: The sample is dissolved in chloroform, a certain amount of iodine monochloride / carbon tetrachloride solution is added, and the mixture is left in the dark for about 1 hour. Then, 15% potassium iodide solution and 50 ml of pure water are added, and any excess iodine monochloride is titrated with a 0.1 N sodium thiosulfate / ethanol aqueous solution. The amount of iodine monochloride added is used to calculate the content. Using this calculation method, the mass of the rubbery polymer contained in the styrene resin (A) (let's call this mass W4) and the mass of the styrene resin (A) (let's call this mass W1) can be used to determine the content (mass%) of the rubbery polymer in the styrene resin (A) using the following formula. From the obtained value, the content (parts by mass) of the rubbery polymer in 100 parts by mass of the styrene resin (A) can be derived. Content (mass%) of rubbery polymer in styrene resin (A) = W4 / W1 × 100

[0031] The volume-average particle size of the rubbery polymer in the styrene-based resin (A) is preferably 1.0 to 8.0 μm, and particularly preferably 1.2 to 7.0 μm, from the viewpoint of strength and rigidity. Having the volume median particle size within this range is preferable because it provides a good balance between impact strength and rigidity. Furthermore, this volume-average particle diameter may be within the range of any two values ​​from 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.5, 6.0, 6.5, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, and 8.0 μm. When a rubbery polymer is used in combination, the volume-average particle diameter of the rubbery polymer refers to the volume-average particle diameter of the entire rubbery polymer used in combination.

[0032] The volume-average particle size of a rubbery polymer can be measured, for example, as follows: The sample is dissolved in dimethylformamide and measured using a laser diffraction particle size analyzer (Beckman Coulter LS-230 laser diffraction particle analyzer).

[0033] The molecular weight of the styrene resin (A) is preferably 10,000 to 500,000 in mass-average molecular weight (Mw), and more preferably 30,000 to 400,000, from the viewpoint of fluidity and heat resistance. Specifically, for example, it can be 10,000, 20,000, 30,000, 40,000, 50,000, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, or 500,000, and may be within the range of any two of the values ​​exemplified here. By using such a range, a styrene resin composition with an excellent balance of fluidity and heat resistance can be obtained. The mass-average molecular weight of the styrene resin (A) can be controlled by the reaction temperature of the polymerization process, residence time, type and amount of polymerization initiator added, type and amount of chain transfer agent added, type and amount of solvent used during polymerization, etc.

[0034] The mass-average molecular weight (Mw) can be measured using gel permeation chromatography (GPC) under the following conditions. GPC model: Shodex GPC-101 manufactured by Showa Denko Corporation Column: PLgel 10μm MIXED-B, manufactured by Polymer Laboratories, Inc. Mobile phase: tetrahydrofuran Sample concentration: 0.2% by mass Temperature: Oven 40°C, Inlet 35°C, Detector 35°C Detector: Differential refractometer The molecular weight of this invention was calculated by determining the molecular weight at each elution time from the elution curve of monodisperse polystyrene, and then calculating it as the molecular weight in terms of polystyrene equivalent.

[0035] For styrene-based resins (A), rubber-modified styrene-based resins (rubber-containing styrene-based resins) are in a form where rubber-like dispersed particles are dispersed in the matrix phase of polystyrene resin, and the molecular weight refers to the molecular weight of the matrix phase. Therefore, the sample used for molecular weight measurement is prepared by dissolving styrene-based resin (A) in a 50% methyl ethyl ketone / 50% acetone mixed solution, removing the rubber-like dispersed particles using a centrifuge (H-2000B (rotor: H) manufactured by Kokusan Co., Ltd.), and then reprecipitation the polymer in methanol. GPC model: Shodex GPC-101 manufactured by Showa Denko Corporation Column: PLgel 5μm MIXED-C, manufactured by Polymer Laboratories, Inc. Mobile phase: tetrahydrofuran Sample concentration: 0.2% by mass Temperature: Oven 40°C, Inlet 35°C, Detector 35°C Detector: Differential refractometer The molecular weight of this invention was calculated by determining the molecular weight at each elution time from the elution curve of monodisperse polystyrene, and then calculating it as the molecular weight in terms of polystyrene equivalent.

[0036] Known styrene polymerization methods include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In terms of quality and productivity, bulk polymerization and solution polymerization are preferred, and continuous polymerization is preferable. Examples of solvents that can be used include alkylbenzenes such as benzene, toluene, ethylbenzene, and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane.

[0037] In continuous polymerization, the polymerization reaction is first controlled by adjusting the polymerization temperature and other means to achieve the target molecular weight, molecular weight distribution, and reaction conversion rate using known fully mixed stirring tanks or tower reactors in the polymerization step. The polymerization solution containing the polymer that exits the polymerization step is transferred to the defoliation step, where unreacted monomers and polymerization solvent are removed. The defoliation step consists of a vacuum defoliation tank with a heater or a defoliation extruder with a vent. The molten polymer that exits the defoliation step is transferred to the granulation step. In the granulation step, the molten resin is extruded in strand form from a porous die and processed into pellets using a cold-cut method, air-hot-cut method, or underwater-hot-cut method.

[0038] During polymerization of styrene-based resin (A), polymerization initiators and chain transfer agents can be used as needed. As polymerization initiators, radical polymerization initiators are preferred, including well-known and conventional peroxyketals such as 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, 2,2-di(4,4-di-t-butylperoxycyclohexyl)propane, and 1,1-di(t-amylperoxy)cyclohexane; hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide; alkyl peroxides such as t-butylperoxyacetate and t-amylperoxyisononanoate; t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, and di-t-hexyl peroxide. Examples of peroxy esters include dialkyl peroxides such as t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl monocarbonate, peroxycarbonates such as t-butyl peroxyisopropyl carbonate and polyethertetrakis(t-butyl peroxycarbonate), N,N'-azobis(cyclohexane-1-carbonitride), N,N'-azobis(2-methylbutyronitrile), N,N'-azobis(2,4-dimethylvaleronitrile), and N,N'-azobis[2-(hydroxymethyl)propionitrile], and one or more of these can be used in combination. Examples of chain transfer agents include aliphatic mercaptans, aromatic mercaptans, pentaphenylethane, α-methylstyrene dimer, and terpinolene.

[0039] The styrene-based resin (A) preferably has a melt mass flow rate (MFR) of 3 g / 10 min or more, measured at 200°C and 49 N. There is no particular upper limit to the MFR, but for example, it can be 35.0 g / 10 min or less, and in some cases it can be less than 32.0 g / 10 min. The MFR (meltmass flow rate) can be, for example, 3.0, 3.5, 4.0, 4.5, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 14.5, 16.0, 17.0, 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0, 25.0, 26.0, 27.0, 28.0, 29.0, 30.0, 31.0, 32.0, 33.0, 34.0, 35.0 g / 10min, and may also be within the range of any two of the values ​​exemplified here. The MFR of styrene resin (A) can be measured according to JIS K 7210.

[0040] <Biomass (B)> In this embodiment, biomass (B) means renewable, biologically derived organic and inorganic resources. Biomass (B) includes organic biomass and / or inorganic biomass. Organic biomass is biomass mainly consisting of solid components derived from aggregates of organic substances (proteins, carbohydrates, lipids, etc.) in living organisms (plants and / or animals). Inorganic biomass is biomass mainly consisting of solid components derived from aggregates of inorganic substances (calcium carbonate, etc.) in living organisms. "Biomass mainly consisting of solid components" means biomass with a moisture content of 30, 25, 20, 15, 10, 5, or 1% by mass or less.

[0041] In one embodiment, biomass (B) is solid food residue. Solid food residue means biomass mainly consisting of solid components derived from food waste. Food waste includes waste from human food and animal feed, and organic and / or inorganic resources of biological origin generated in the manufacturing processes of the above food and feed. In one embodiment, solid food residue is plant-based. In another embodiment, solid food residue is waste derived from plant-based seeds (soybeans, rice, corn, coffee beans, cocoa, etc.), vegetables (leeks, cabbage, onions, etc.), and fruits (sugarcane, apples, oranges, etc.). In one embodiment, biomass (B) excludes woody biomass.

[0042] In one embodiment, when the total amount of styrene resin (A) and biomass (B) is 100 parts by mass, the biomass (B) content may be 1 to 90 parts by mass (for example, within a range between two values ​​selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80 and 90 parts by mass).

[0043] <Zinc-based deodorant (C)> In this embodiment, the zinc-based deodorant (C) means an inorganic deodorant containing zinc. In one embodiment, the zinc-based deodorant (C) is at least one selected from the group consisting of zinc oxide, zinc hydroxide, zinc silicate, zinc stearate, and zinc carbonate. In another embodiment, the zinc-based deodorant (C) is zinc oxide and / or zinc stearate.

[0044] In one embodiment, the content of the zinc-based deodorant (C) is 1 part by mass or more per 100 parts by mass of biomass (B). In another embodiment, the content of the zinc-based deodorant (C) is 1 part by mass or more and 150 parts by mass or less per 100 parts by mass of biomass (B) (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, (60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145 and 150 parts by mass, and within a range between two values ​​selected from the group consisting of these.)

[0045] <Molded body> There are no particular limitations on the molding method used to obtain molded articles, films, sheets, and foams from the styrene-based resin composition according to this embodiment. Known molding methods such as extrusion molding, including calendering, hollow molding, extrusion foam molding, shape extrusion molding, lamination molding, inflation molding, T-die film molding, sheet molding, vacuum molding, and pressure molding, as well as injection molding, including RIM molding and injection foam molding, can be suitably used.

[0046] Examples of thermoforming methods include conventionally known general forming methods such as vacuum forming, pressure forming, or applications thereof such as free drawing forming, plug-and-ridge forming, ridge forming, matched mold forming, straight forming, drape forming, reverse draw forming, air slip forming, plug-assisted forming, and plug-assisted reverse load forming.

[0047] <Method for producing styrene-based resin compositions> The method for producing a styrene-based resin composition according to this embodiment includes the step of mixing a styrene-based resin (A), biomass (B), and a zinc-based deodorant (C) under specific temperature conditions, wherein the specific temperature is 165°C or higher and 200°C or lower.

[0048] The method for mixing the styrene resin (A), biomass (B), and zinc-based deodorant (C) is not particularly limited, and known mixing techniques can be applied. For example, a uniform resin composition can be produced by pre-mixing the various raw materials using a mixing device such as a mixer-type mixer, a V-type blender, and a tumbler-type mixer, and then melt-kneading the mixture. The melt-kneading device is also not particularly limited, but examples include a Banbury-type mixer, a kneader, a roll, a single-screw extruder, a special single-screw extruder, and a twin-screw extruder. Furthermore, there is also a method of adding other additives separately during the melt-kneading process using a melt-kneading device such as an extruder.

[0049] The styrene resin (A), biomass (B), and zinc-based deodorant (C) may be mixed simultaneously or sequentially. In one embodiment, the process of mixing the styrene resin (A), biomass (B), and zinc-based deodorant (C) under specific temperature conditions includes the steps of melting and kneading the styrene resin (A) and adding the biomass (B) and zinc-based deodorant (C) to the molten styrene resin (A). In another embodiment, the process of mixing the styrene resin (A), biomass (B), and zinc-based deodorant (C) under specific temperature conditions includes the steps of melting and kneading the styrene resin (A), adding the biomass (B) to the molten styrene resin (A), and adding the zinc-based deodorant (C) to the molten styrene resin (A) and biomass (B). In yet another embodiment, the step of mixing a styrene resin (A), biomass (B), and a zinc-based deodorant (C) under specific temperature conditions includes the steps of melting and kneading the styrene resin (A), adding the zinc-based deodorant (C) to the molten styrene resin (A), and adding the biomass (B) to the molten styrene resin (A) and zinc-based deodorant (C).

[0050] <Specific temperature> The specific temperature in this embodiment is a temperature at which the styrene resin (A) is melted and odors derived from biomass (B) are suppressed, and is between 165°C and 200°C (for example, within a range of two values ​​selected from 165, 170, 175, 180, 185, 190, 195, and 200°C, and the group consisting of these). If the specific temperature is below 165°C, the styrene resin (A) does not melt sufficiently and cannot be kneaded, and if the specific temperature exceeds 200°C, unacceptable odors derived from biomass (B) are generated due to the decomposition of the biomass. The specific temperature in this embodiment can be set by controlling the temperature of a heating device (such as a cylinder) in the mixing apparatus. In one embodiment, the specific temperature is the temperature of the styrene resin (A), biomass (B), and zinc-based deodorant (C), as well as the mixture thereof (styrene resin composition), in the process of mixing the styrene resin (A), biomass (B), and zinc-based deodorant (C) under the conditions of the specific temperature. Through a process of mixing styrene resin (A), biomass (B), and zinc-based deodorant (C) under specific temperature conditions, the temperature of the styrene resin (A), biomass (B), zinc-based deodorant (C), and their mixture (styrene resin composition) reaches the specific temperature. [Examples]

[0051] The present invention will be described in more detail below with reference to examples. These examples are illustrative and do not limit the scope of the present invention.

[0052] The materials used in the examples and comparative examples are as follows:

[0053] [Styrene resin (A)] (A-1) HIPS (polystyrene resin modified with polybutadiene rubber, molecular weight (Mw) 150,000, rubbery polymer content 7% by mass in 100% by mass of resin, volume average particle size 4.4 μm, MFR 11 g / 10 min) (A-2) GPPS (Polystyrene resin, molecular weight (Mw) 170,000, MFR 31g / 10min) (A-3) Styrene-methacrylic acid copolymer (molecular weight (Mw) 200,000, glass transition temperature (Tg) 122°C, 10 parts by mass of methacrylic acid monomer)

[0054] [Biomass (B)] (B-1) Dried okara (moisture content 4%) (manufactured by Sagamiya Foods Co., Ltd.) (B-2) Rice flour (moisture content 2.6%) (B-3) Coffee grounds (moisture content 4%)

[0055] [Biomass (B)] (C-1) Zinc Oxide (C-2) Zinc stearate (C-3) Zeolite-based adsorbent (C-4) Silica-based adsorbent (C-5) Titanium Dioxide (C-6) Manganese Dioxide

[0056] (Examples 1-16, Comparative Examples 17-25) Each component was pre-mixed in the proportions (mass%) shown in Tables 1 and 2 using a Henschel mixer (Mitsui Miike Chemical Co., Ltd., FM20B), and then supplied to a twin-screw extruder (Toshiba Machine Co., Ltd., TEM26SX) to form strands under conditions of cylinder temperature 160°C to 210°C and supply rate 10 kg / h. After water cooling, the mixture was fed to a pelletizer and pelletized. The resulting pellets were injection molded, and the results of evaluating various properties are shown in Tables 1 and 2.

[0057] [Sensory evaluation of odor] Four inspectors smelled the manufactured pellets and evaluated their odor using a 6-point odor intensity scale. The average of the obtained evaluations was used as the sensory evaluation. The evaluation criteria were as follows: 0: Odorless, 1: Barely perceptible odor, 2: Weak odor that can be identified, 3: Easily perceptible odor, 4: Strong odor, 5: Intense odor. Average evaluation score <2: A (No problem level), 2 ≤ average evaluation score <3: B (Acceptable level), Average evaluation score ≥3: C (Unacceptable).

[0058] [Color evaluation] The color of the manufactured pellets was visually inspected and evaluated on a three-point scale. The evaluation criteria were as follows: A: No yellowing, similar to HIPS; B: White to yellow discoloration (acceptable); C: Yellow to brown discoloration (unacceptable).

[0059] [Table 1]

[0060] [Table 2]

[0061] Examples 1-16 in Table 1 show that the styrene-based resin compositions of the present invention had suppressed biomass-derived odors and excellent color. On the other hand, Comparative Examples 17-23 in Table 2 show that resin compositions that did not satisfy the provisions of the present invention had strong biomass-derived odors, and the styrene-based resin compositions were yellowish. It was found that they had poor extrusion stability and pellet color, and a low Vicat softening temperature. In Comparative Example 24 in Table 2, the cylinder temperature was lower than the melting point of the styrene resin, so the styrene resin did not melt, and it was not possible to produce a styrene-based resin composition. In Comparative Example 25 in Table 2, the cylinder temperature was high, and the biomass-derived odor was the strongest. [Industrial applicability]

[0062] The method for producing a styrene-based resin composition according to the present invention can suppress the generation of biomass-derived odors in the styrene-based resin composition. The styrene-based resin composition according to the present invention can be suitably used as molded articles, films, sheets, and foams, and has industrial applicability.

Claims

1. The process includes a step of mixing a styrene resin (A), biomass (B), and a zinc-based deodorant (C) under specific temperature conditions. The aforementioned specific temperature is between 165°C and 200°C. A method for producing a styrene-based resin composition.

2. The manufacturing method according to claim 1, wherein the zinc-based deodorant (C) is zinc oxide and / or zinc stearate.

3. The manufacturing method according to claim 1, wherein the biomass (B) is solid food residue.

4. The manufacturing method according to claim 3, wherein the solid food residue is plant-based.

5. When the total amount of the styrene resin (A) and the biomass (B) is 100 parts by mass, the content of the biomass (B) is 1 to 90 parts by mass. The manufacturing method according to claims 1 to 4, wherein the content of the zinc-based deodorant (C) is 1 part by mass or more per 100 parts by mass of the biomass (B).

6. Styrene resin (A) and Biomass (B) and Zinc-based deodorant (C), A styrene-based resin composition containing [the specified ingredient].

7. The styrene-based resin composition according to claim 6, wherein the zinc-based deodorant (C) is zinc oxide and / or zinc stearate.

8. The styrene-based resin composition according to claim 6, wherein the biomass (B) is solid food residue.

9. The styrene-based resin composition according to claim 8, wherein the solid food residue is plant-based.

10. When the total amount of the styrene resin (A) and the biomass (B) is 100 parts by mass, the content of the biomass (B) is 1 to 90 parts by mass. The styrene-based resin composition according to claim 6, wherein the content of the zinc-based deodorant (C) is 1 part by mass or more per 100 parts by mass of the biomass (B).

11. A molded article obtained by molding a styrene-based resin composition according to any one of claims 6 to 10.

12. A film comprising the styrene-based resin composition according to any one of claims 6 to 10.

13. A sheet comprising the styrene-based resin composition according to any one of claims 6 to 10.

14. A foam comprising the styrene-based resin composition according to any one of claims 6 to 10.

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