WO2023234237A1 - Composite resin material and molded article - Google Patents

Abstract

Provided are a composite resin material capable of providing a molded article having excellent mechanical strength and good appearance, and a molded article of the composite resin material.　A composite resin material that comprises: at least one plant component-containing material (A) selected from the group consisting of a resin composition (A-1) containing a plant-derived filler (a-1) and a thermoplastic resin (a-2), a thermoplastic resin (A-2) containing a plant material-derived monomer unit, and a thermoplastic starch (A-3); and a resin composition (B) containing a thermoplastic resin (b-1) and regenerated cellulose fibers (b-2).

Description

Composite resin materials and molded products

The present invention relates to composite resin materials and molded products.

In order to build a sustainable society, the use of composite resin materials that combine petroleum-derived resin components with biomass components is progressing. As these composite resin materials, for example, Patent Document 1 proposes a speaker member in which a plant-derived material such as waste rice is combined with a polypropylene resin or the like.

In such composite resin materials, inclusion of biomass components can be expected to improve the elastic modulus, but on the other hand, mechanical strength, especially impact strength, may be lower than that of materials containing only petroleum-derived resin components. be. On the other hand, it is also being considered to incorporate inorganic fillers such as glass fibers to reinforce the impact strength.

By the way, in products that are visible to people, such as daily necessities and interior goods, colors, textures, and patterns derived from natural substances, such as brown, are accepted and sometimes preferred. However, unnatural color irregularities, such as white spots or black spots that can be seen at a glance even though the product is brown overall, give the impression of an abnormality and often result in a defective product in terms of appearance. . The aforementioned method of reinforcing the impact strength of a composite resin material by blending an inorganic filler such as glass fiber has the problem of causing poor appearance of the molded product. This phenomenon is caused by, for example, the flow pattern of petroleum-derived resin filled with inorganic filler such as glass fiber being linear, and the flow pattern of petroleum-derived resin filled with inorganic filler such as glass fiber being different from that of the main material, which flows in a curved mold shape. As a result, the flowing pattern of the inorganic filler stands out and appears white, which is considered to be one of the reasons.

Japanese Patent Application Publication No. 2011-239264

Therefore, an object of the present invention is to provide a composite resin material that can provide a molded product with excellent mechanical strength and a good appearance, and a molded product of the composite resin material.

As a result of intensive studies, the inventors of the present application surprisingly found that by combining a material containing plant components with a resin composition containing regenerated cellulose fibers, a composite resin material that can solve all of the above problems can be obtained. This discovery led to the completion of the present invention.
That is, the present invention has the following aspects.
[1] Resin composition (A-1) containing plant-derived filler (a-1) and thermoplastic resin (a-2), thermoplastic resin (A-2) containing monomer units derived from plant raw materials , and at least one plant component-containing material (A) selected from the group consisting of thermoplastic starch (A-3);
A composite resin material comprising a thermoplastic resin (b-1) and a resin composition (B) containing regenerated cellulose fibers (b-2).
[2] The total content of the thermoplastic resin in the composite resin material is 30 to 90% by mass, and the content of the regenerated cellulose fiber (b-2) is 10 to 40% by mass, [ 1].
[3] Thermoplastic resin impregnation in which the resin composition (B) impregnates a fiber bundle in which the regenerated cellulose fibers (b-2) are aligned in the length direction with the thermoplastic resin (b-1). The composite resin material according to [1] or [2], comprising the regenerated cellulose fiber bundle (B-1).
[4] The composite resin material according to any one of [1] to [3], wherein the regenerated cellulose fiber (b-2) in the resin composition (B) has an average fiber length of 6 to 30 mm. .
[5] The composite resin material according to any one of [1] to [4], wherein the plant-derived filler (a-1) contains at least one selected from crushed seeds and plant fibers.
[6] Any one of [1] to [5], wherein the proportion of the plant-derived filler (a-1) to the total mass of the resin composition (A-1) is 30 to 80% by mass. Composite resin material described.
[7] The composite resin material according to any one of [1] to [6], wherein the thermoplastic resin (A-2) contains high-density polyethylene containing ethylene units derived from plant materials.
[8] Thermoplastic resin impregnation in which the resin composition (B) impregnates a fiber bundle in which the regenerated cellulose fibers (b-2) are aligned in the length direction with the thermoplastic resin (b-1). Contains a regenerated cellulose fiber bundle (B-1),
Any one of [1] to [7], wherein the proportion of the regenerated cellulose fiber (b-2) to the total mass of the thermoplastic resin-impregnated regenerated cellulose fiber bundle (B-1) is 10 to 50% by mass. Composite resin material described in .
[9] The composite resin material according to any one of [1] to [8], wherein the regenerated cellulose fiber (b-2) contains viscose rayon.
[10] The composite resin material is a mixture of pellets (I) containing the plant component-containing material (A) and pellets (II) containing the resin composition (B), [1] to [9] ] The composite resin material according to any one of.
[11] The composite resin material according to any one of [1] to [10], which is for injection molding.
[12] A molded article of the composite resin material according to any one of [1] to [11].

According to the present invention, it is possible to provide a composite resin material that can provide a molded product that has excellent mechanical strength and a good appearance, and a molded product made of the composite resin material.

Hereinafter, one embodiment of the present invention will be described in detail, but the scope of the present invention is not limited to the one embodiment described here, and various changes can be made without departing from the spirit of the present invention. Additionally, if multiple upper and lower limit values are listed for a specific parameter, any of these upper and lower limit values may be combined to form a suitable numerical range. can. Further, in this specification, the expression "-" means "more than or less than". For example, "10 to 50% by mass" means "10% by mass or more and 50% by mass or less".

[Composite resin material]
The composite resin material according to the present embodiment includes a resin composition (A-1) containing a plant-derived filler (a-1) and a thermoplastic resin (a-2), a thermoplastic resin composition containing monomer units derived from plant raw materials, and At least one plant component-containing material (A) selected from the group consisting of a plastic resin (A-2) and a thermoplastic starch (A-3), a thermoplastic resin (b-1) and a regenerated cellulose fiber (b -2). The composite resin material according to this embodiment can provide a molded product with excellent mechanical strength and good appearance. Furthermore, the composite resin material according to the present embodiment can improve mechanical strength, particularly impact strength, without adding an inorganic filler such as glass fiber. Therefore, no incineration ash is generated when the molded product obtained from the composite resin material according to this embodiment is collected and thermally recycled.

<Plant component-containing material (A)>
The composite resin material according to the present embodiment includes a resin composition (A-1) containing a plant-derived filler (a-1) and a thermoplastic resin (a-2), a thermoplastic resin composition containing monomer units derived from plant raw materials, and At least one plant component-containing material (A) selected from the group consisting of a plastic resin (A-2) and a thermoplastic starch (A-3) (hereinafter sometimes simply referred to as "material (A)") )including.

(Resin composition (A-1))
The material (A) according to this embodiment can include a resin composition (A-1). The resin composition (A-1) contains a plant-derived filler (a-1) and a thermoplastic resin (a-2).

(Plant-derived filler (a-1))
The plant-derived filler (a-1) (hereinafter sometimes simply referred to as "filler (a-1)") has the effect of the present invention if it is a filler composed of a plant-derived material. There are no particular limitations. In one embodiment, the filler (a-1) includes, for example, crushed plant products, plant fibers, and the like.

Examples of pulverized plant products include pulverized plant leaves, stems, roots, seeds (including grains), etc., which are processed into particles or powder. The pulverized plant material may be a pulverized product of a specific part, or may be a mixture of pulverized products of a plurality of different parts. When the filler (a-1) contains a crushed plant material, it preferably contains a crushed seed material. In one embodiment, from the viewpoint of high production volume and waste utilization, it is more preferable to include pulverized grains, and even more preferably to include pulverized rice, wheat, or coffee beans. In one embodiment, the pulverized seeds containing grains may include rice (waste rice) or barley derived from food waste, or pulverized coffee beans after extraction.

Plant fibers are plant-derived fibers extracted from wood and/or non-wood materials, and are called "pulp." The part from which the plant fibers are extracted is not particularly limited as long as it has the effects of the present invention, and may be any of the woody part, non-woody part, leaf part, stem part, root part, etc. Further, the plant fibers may be fibers taken out from a specific part, or may be mixed fibers of fibers taken out from a plurality of different parts.
Fibers extracted from plants may be used as plant fibers in combination with the thermoplastic resin (a-2), or may be used as plant fibers after being subjected to various processing. Processing methods include retting (including retting using microorganisms, retting using enzymes, etc.), boiling, steaming, heating, drying, cutting, beating, washing, and chemical treatment, and these methods cannot be performed alone. or a combination of two or more types.

The plant species from which plant fibers are extracted are not limited, and include, for example, kenaf, jute hemp, manila hemp, sisal hemp, gampi, mitsumata, mulberry, banana, pineapple, coconut palm, corn, sugarcane, bagasse, palm, papyrus, reed, esparto, and sabai grass. , wheat, rice, bamboo, coniferous trees (cedar, cypress, etc.), broad-leaved trees, cotton, etc. These may be used alone or in combination of two or more.
In one embodiment, the plant fibers may include cellulose pulp. "Cellulose pulp" refers to fibers obtained from wood or non-wood plants. As the cellulose raw material, one type of the above-mentioned plant species can be used alone, or two or more types can be used in combination. Note that the plant-derived filler (a-1) preferably does not contain regenerated cellulose fibers (b-2), which will be described later.

When the filler (a-1) contains vegetable fibers, the average fiber length of the vegetable fibers is preferably 0.5 to 500 μm from the viewpoint of fiber dispersibility and mechanical strength of the resulting molded product, More preferably, it is 1.0 to 100 μm.

In one embodiment, the filler (a-1) preferably contains at least one selected from crushed seeds and vegetable fibers, including crushed rice (including waste rice), cellulose pulp, and coffee. It is more preferable to include at least one selected from ground beans.

(Thermoplastic resin (a-2))
The resin composition (A-1) contains a thermoplastic resin (a-2) (hereinafter sometimes simply referred to as "resin (a-2)"). The thermoplastic resin (a-2) is not particularly limited as long as it has the effects of the present invention, and any thermoplastic resin can be used. As the resin (a-2), olefin resin, vinyl alcohol resin, vinyl ester resin, styrene resin, (meth)acrylic resin, polyester resin, polycarbonate resin, polyamide resin, polysulfone resin, Examples include polyphenylene resin, polyacetal resin, thermoplastic elastomer, and the like.

Examples of olefin resins include homopolymers or copolymers of olefins having 2 to 6 carbon atoms (ethylene resins such as polyethylene, ethylene-propylene copolymers; polypropylene, propylene-ethylene copolymers, propylene-butenes); Propylene resins such as copolymers; poly(methylpentene-1); propylene-methylpentene copolymers, etc.); copolymers of olefins having 2 to 6 carbon atoms and copolymerizable monomers (ethylene-( (meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, etc.); Cyclic olefin that may have a substituent such as an alkyl group or an ester group (especially a cyclic olefin condensed with a hydrocarbon ring) homopolymers or copolymers of cyclic olefins such as polybicyclopentadiene, polynorbornene; bicycloalkadienes, tricycloalkadienes, bicycloalkenes, and tricycloalkenes; Examples include copolymers of cyclic olefins selected from the following and α-olefins having 2 to 4 carbon atoms (ethylene, etc.). These may be used alone or in combination of two or more.

When using an olefin resin, an acid-modified polyolefin may be used in combination from the viewpoint of easy adhesion to the plant-derived filler (a-1). As the acid-modified polyolefin, maleic acid-modified polyolefin (more preferably maleic acid-modified polypropylene) and maleic anhydride-modified polyolefin (more preferably maleic anhydride-modified polypropylene) are preferred.

Vinyl resins include polyvinyl alcohol, ethylene-vinyl alcohol copolymers, and the like. These may be used alone or in combination of two or more.

Vinyl ester resins (carboxylic acid vinyl ester resins) include, for example, homopolymers or copolymers of carboxylic acid vinyl ester monomers such as polyvinyl acetate; ethylene-vinyl acetate copolymers, vinyl acetate- Examples include copolymers of carboxylic acid vinyl ester monomers and copolymerizable monomers, such as (meth)acrylic acid ester copolymers. These may be used alone or in combination of two or more.

Styrenic resins include, for example, homopolymers or copolymers of styrene monomers (polystyrene, styrene-α-methylstyrene copolymers, etc.); styrene monomers and other copolymerizable monomers. (styrene-acrylonitrile copolymer (AS resin), styrene-(meth)acrylate copolymer, styrene-maleic anhydride copolymer, etc.). These may be used alone or in combination of two or more.

Examples of (meth)acrylic resins include poly(meth)acrylic esters such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymers, and methyl methacrylate-(meth)acrylic acid. Examples include ester copolymers, methyl methacrylate-(meth)acrylic ester-(meth)acrylic acid copolymers, and (meth)acrylic ester-styrene copolymers (MS resins, etc.). These may be used alone or in combination of two or more.

Examples of polyester resins include homopolyesters or copolyesters (such as adipic acid having 6 carbon atoms such as adipic acid) having alkylene terephthalate (ethylene terephthalate, butylene terephthalate, etc.) or alkylene naphthalate (ethylene naphthalate, butylene naphthalate, etc.) as a repeating unit. Copolyesters containing asymmetric aromatic dicarboxylic acids such as ~12 aliphatic dicarboxylic acids, phthalic acid, and isophthalic acid, and alkylene glycols having 2 to 6 carbon atoms, polyoxyalkylene glycols, bisphenol A, etc.) ; Aromatic polyesters (polyarylate resins produced by the reaction of aromatic diols such as bisphenol A with aromatic dicarboxylic acids such as terephthalic acid, etc.); Liquid crystalline polyesters; Lactones (ε-caprolactone, etc.) alone or in combination Examples include polymers. These may be used alone or in combination of two or more.

Examples of polycarbonate resins include polycarbonates obtained by reacting dihydroxy compounds (bisphenol compounds such as bisphenol A and bisphenol S) with phosgene or carbonic acid diesters (dialkyl carbonates such as diphenyl carbonate and dimethyl carbonate), and the like. It will be done. These may be used alone or in combination of two or more.

Examples of polyamide resins include aliphatic polyamides and aromatic polyamides.
Examples of the aliphatic polyamide include polyamide 6, polyamide 66, polyamide 69, polyamide 610, polyamide 1010, polyamide 612, polyamide 46, polyamide 11, and polyamide 12. These may be used alone or in combination of two or more.
Examples of aromatic polyamides include those obtained from aromatic dicarboxylic acids and aliphatic diamines, or from aliphatic dicarboxylic acids and aromatic diamines. Specifically, polyamide MXD (metaxylylene diamine and adipic acid), polyamide 6T (hexamethylene diamine and terephthalic acid), polyamide 6I (hexamethylene diamine and isophthalic acid), polyamide 9T (nonanediamine and terephthalic acid), polyamide M5T (methylpentadiamine and terephthalic acid) and polyamide 10T (decamethylene diamine and terephthalic acid). These may be used alone or in combination of two or more.

Examples of polysulfone-based resins include polysulfone, polyethersulfone, and the like. These may be used alone or in combination of two or more.

Examples of polyphenylene resins include polyphenylene oxide resins [poly(2,5-dimethyl-1,4-phenylene) oxide, poly(2,6-dimethyl-1,4-phenylene) oxide, poly(2-methyl -6-ethyl-1,4-phenylene) oxide, poly(2,6-di-n-propyl-1,4-phenylene) oxide, poly(2-methyl-6-chloroethyl-1,4-phenylene) oxide homopolymers such as; modified polyphenylene oxide copolymers constructed based on polyphenylene oxide blocks; modified graft copolymers in which a styrene polymer is grafted to polyphenylene oxide or its copolymer, etc.]; polyphenylene sulfide-based Examples include resins (polyphenylene sulfide, polyphenylene sulfide ketone, polybiphenylene sulfide, polyphenylene sulfide sulfone, etc.). These may be used alone or in combination of two or more.

Examples of polyacetal-based resins include polyacetal homopolymers containing only oxymethylene groups as constituent units, and polyacetal copolymers containing oxyethylene groups and the like as constituent units in addition to oxymethylene groups. These may be used alone or in combination of two or more.

Examples of the thermoplastic elastomer include hard thermoplastic elastomers such as polyolefin thermoplastic elastomers, polystyrene thermoplastic elastomers, polyvinyl chloride thermoplastic elastomers, polyurethane thermoplastic elastomers, polyester thermoplastic elastomers, and polyamide thermoplastic resin elastomers. Examples include thermoplastic elastomers that are composed of a phase and a soft phase. These may be used alone or in combination of two or more.
Among these, as the resin (a-2), olefin resins, styrene resins, (meth)acrylic resins, polyester resins, polycarbonate resins, and polyacetal resins are preferable.

As the resin (a-2), one of the aforementioned thermoplastic resins may be used alone, or two or more types may be used in combination. Further, it may be modified (for example, rubber modified) as necessary.

In one embodiment, the resin (a-2) preferably includes an olefin resin or a polyacetal resin from the viewpoint of mechanical strength for use in the structure and process temperature that the regenerated cellulose fiber can withstand.
When the resin (a-2) contains an olefin resin, a homopolymer or copolymer of an olefin having 2 to 6 carbon atoms is preferable, and polypropylene is more preferable. The polypropylene may be a homopolymer of propylene (homopolypropylene), block polypropylene, random polypropylene, or a mixture thereof.

When the resin (a-2) contains a polyacetal resin, a polyacetal homopolymer or a polyacetal copolymer is preferable, and a polyacetal copolymer is more preferable.

In one embodiment, the proportion of the plant-derived filler (a-1) to the total mass of the resin composition (A-1) is preferably 30 to 80% by mass, more preferably 40 to 80% by mass, and 50 to 80% by mass. 80% by mass is more preferred. When the proportion of the filler (a-1) in the resin composition (A-1) is 30 to 80% by mass, the resulting molded product tends to have good mechanical strength.

In one embodiment, the resin composition (A-1) may contain any component other than the filler (a-1) and resin (a-2) described above. The optional components are not particularly limited as long as they have the effects of the present invention, and may include conventionally known additives that can be blended into thermoplastic resin compositions.

A commercially available product may be used as the resin composition (A-1). Commercially available products include, for example, "Rice Resin (registered trademark)" manufactured by Biomass Resin Holdings Co., Ltd. and "Selbren" manufactured by Daicel Miraiz Co., Ltd.

The method for obtaining the resin composition (A-1) is not particularly limited, and after blending the aforementioned filler (a-1), resin (a-2), and optional components as necessary, a conventionally known method may be used. For example, the resin composition (A-1) can be obtained by melt-kneading using a single-screw or twin-screw extruder. Alternatively, the resin composition may be obtained in the form of pellets by cutting it into a predetermined length using a pelletizer.

(Thermoplastic resin (A-2))
In this embodiment, the material (A) can include a thermoplastic resin (A-2). The thermoplastic resin (A-2) is a thermoplastic resin containing monomer units derived from plant raw materials. The thermoplastic resin (A-2) is a thermoplastic resin containing a biomass component made from a plant as a monomer, for example, an olefin resin containing an olefin unit derived from a plant material, or an ethylene glycol unit derived from a plant material. , polyethylene terephthalate, polylactic acid containing lactic acid derived from plant materials as a monomer unit, and the like. As the thermoplastic resin (A-2), one type of these thermoplastic resins may be used alone, or two or more types may be used in combination. Among these, from the viewpoint of easily solving the problem of insufficient mechanical strength and easily recycling, it is preferable that the thermoplastic resin (A-2) contains an olefin resin containing olefin units derived from plant materials. It is more preferable to include polyethylene containing ethylene units derived from raw materials.
In one embodiment, when the thermoplastic resin (A-2) contains polyethylene containing ethylene units derived from plant materials, the polyethylene has a density of 0.91 to 0.96 g/cm ³ , more preferably 0.94 g/cm 3 . Preferably, it is high density polyethylene (HDPE) with ˜0.96 g/cm ³ .

In one embodiment, the proportion of monomer units derived from plant materials in the thermoplastic resin (A-2) is the total amount (100% by mass) of all monomer units constituting the thermoplastic resin (A-2). ), preferably 90% by mass or more, more preferably 95% by mass or more. Further, the thermoplastic resin (A-2) may be composed only of monomer units derived from plant materials.

The thermoplastic resin (A-2) can be prepared by polymerizing a monomer mixture containing monomers derived from plant materials by a conventionally known method, for example, a medium-low pressure method using a Ziegler-Nutter catalyst or the like.

(Thermoplastic starch (A-3))
Material (A) can include thermoplastic starch (A-3). "Thermoplastic starch" refers to the temperature at which starch or a composition containing starch can be sufficiently processed, for example, when forming a homogeneous mixture and/or combining with the resin composition (B) described below to form a molded article. For example, it refers to a starch composition that can maintain fluidity when heated to temperatures above 180°C.

The "starch" constituting the thermoplastic starch (A-3) is not particularly limited as long as it is derived from plant materials and has the effects of the present invention. For example, corn starch, potato starch, sweet potato starch, wheat starch, sago starch, tapioca starch, rice starch, soybean starch, arrow root starch, bracken starch, lotus starch, cassava starch, waxy maize starch, Examples include high amylase corn starch. These may be used alone or in combination of two or more. Among these, corn is preferred from the viewpoint of production of a product that does not compete with food.

Starch obtained from corn, rice, etc. is a natural polymer and usually has crystallinity, so it is difficult to thermoplasticize even when heated as is. Therefore, the thermoplastic starch (A-3) is preferably a modified starch derived from plant materials. The denaturation method is not particularly limited, and denaturation may be carried out by heating, enzymatic denaturation, chemical modification such as ethoxylation, chemical decomposition, or a combination thereof. In one embodiment, the thermoplastic starch (A-3) may be a starch modified by the addition of a plasticizer.

As mentioned above, the thermoplastic starch (A-3) can be prepared by modifying starch obtained from corn, rice, etc. by a conventionally known method, if necessary.

A commercially available product may be used as the thermoplastic starch (A-3). Examples of commercially available products include "SANKYO GOLDEN STARCH" manufactured by Sankyo Chemical Industry Co., Ltd.

In one embodiment, the material (A) may contain other components than the aforementioned resin composition (A-1), thermoplastic resin (A-2), and thermoplastic starch (A-3). Other ingredients include, for example, softeners, surface lubricants, leveling agents, antioxidants, surfactants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, heat stabilizers, polymerization inhibitors, and silane coupling agents. , lubricants, plasticizers, crystallization promoters, hydrolysis inhibitors, inorganic fillers, organic fillers other than those derived from plants, metal powders, pigments, and the like. These may be used alone or in combination of two or more. When material (A) contains other components, the content can be 1% by mass or less based on the total mass of material (A).

In one embodiment, the proportion of material (A) in the composite resin material may be 30 to 90% by mass, or 40 to 80% by mass, based on the total mass of the composite resin material, It may be 50 to 80% by mass.

<Resin composition (B)>
The composite resin material according to this embodiment includes a resin composition (B) containing a thermoplastic resin (b-1) and regenerated cellulose fibers (b-2). By including the resin composition (B) in the composite resin material, a molded article with excellent mechanical strength and good appearance can be provided.

(Thermoplastic resin (b-1))
In this embodiment, the thermoplastic resin (b-1) (hereinafter sometimes simply referred to as "resin (b-1)") contained in the resin composition (B) is the thermoplastic resin ( The same example as a-2) can be given. In one embodiment, the resin (b-1) includes an olefin resin, a polyamide resin, a styrene resin, a halogen-containing resin, a polycarbonate resin, a (meth)acrylic resin, a polyester resin, a polyacetal resin, and It may be at least one selected from polyphenylene resins. Moreover, it is more preferable that it is at least one selected from olefin resin, polyamide resin, and polyacetal resin.

Examples of olefin resins that can be suitably used as the resin (b-1) include homopolymers or copolymers of olefins having 2 to 6 carbon atoms (ethylene resins such as polyethylene and ethylene-propylene copolymers; polypropylene , propylene-based resins such as propylene-ethylene copolymer, propylene-butene copolymer; poly(methylpentene-1); propylene-methylpentene copolymer, etc.); copolymers with polymers (ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester copolymers, etc.); cyclic polymers that may have substituents such as alkyl groups and ester groups; Homopolymers or copolymers of olefins (especially cyclic olefins condensed with hydrocarbon rings, bridged cyclic olefins, etc.) (for example, homopolymers of cyclic olefins such as polybicyclopentadiene and polynorbornene; bicycloalkadienes, Examples include copolymers of cyclic olefins selected from cycloalkadienes, bicycloalkenes, and tricycloalkenes and α-olefins having 2 to 4 carbon atoms (ethylene, etc.). These may be used alone or in combination of two or more. Among these, from the viewpoint of mechanical strength and processability, homopolymers or copolymers of olefins having 2 to 6 carbon atoms are preferred, and polypropylene is more preferred. The polypropylene may be a homopolymer of propylene (homopolypropylene), block polypropylene, random polypropylene, or a mixture thereof.

When using an olefin resin as the resin (b-1), an acid-modified polyolefin may be used in combination from the viewpoint of easy adhesion to the regenerated cellulose fibers (b-2). As the acid-modified polyolefin, maleic acid-modified polyolefin (more preferably maleic acid-modified polypropylene) and maleic anhydride-modified polyolefin (more preferably maleic anhydride-modified polypropylene) are preferred.
In one embodiment, when an olefin resin and an acid-modified polyolefin are used together as the resin (b-1), the amount of acid in the resin (b-1) (the amount of acid components contained in the acid-modified polyolefin) is It is preferable to use acid-modified polyolefin in an average amount of 0.05 to 0.5% by mass in terms of maleic acid.

Polyamide resins that can be suitably used as the resin (b-1) include aliphatic polyamides and aromatic polyamides.
Examples of the aliphatic polyamide include polyamide 6, polyamide 66, polyamide 69, polyamide 610, polyamide 1010, polyamide 612, polyamide 46, polyamide 11, and polyamide 12. These may be used alone or in combination of two or more.
Examples of aromatic polyamides include those obtained from aromatic dicarboxylic acids and aliphatic diamines, or from aliphatic dicarboxylic acids and aromatic diamines. Specifically, polyamide MXD (metaxylylene diamine and adipic acid), polyamide 6T (hexamethylene diamine and terephthalic acid), polyamide 6I (hexamethylene diamine and isophthalic acid), polyamide 9T (nonanediamine and terephthalic acid), polyamide M5T (methylpentadiamine and terephthalic acid) and polyamide 10T (decamethylene diamine and terephthalic acid). These may be used alone or in combination of two or more.
Among these polyamide resins, aliphatic polyamides such as polyamide 6, polyamide 69, polyamide 610, polyamide 612, polyamide 11, polyamide 12, and polyamide 1010 are preferred from the viewpoint of processing temperature.

Examples of polyacetal resins that can be suitably used as the resin (b-1) include polyacetal homopolymers having only oxymethylene groups as a constituent unit, polyacetal copolymers having oxyethylene groups, etc. as constituent units in addition to oxymethylene groups, and the like. can be mentioned. These may be used alone or in combination of two or more.
Among these, from the viewpoint of mechanical strength and processability, polyacetal homopolymers or polyacetal copolymers are preferred, and polyacetal copolymers are more preferred.

(Regenerated cellulose fiber (b-2))
In this embodiment, the resin composition (B) contains regenerated cellulose fibers (b-2). "Regenerated cellulose fiber" refers to cellulose fiber that is artificially spun using natural cellulose fibers (cellulose fibers derived from higher plants, cellulose fibers derived from animals, cellulose fibers derived from bacteria).

Examples of cellulose fibers derived from higher plants include wood fibers (wood pulp from softwood, hardwood, etc.), bamboo fibers, sugarcane fibers, seed hair fibers (cotton linters, bombax cotton, kapok, etc.), and gin bark fibers (e.g. Examples include natural cellulose fibers (pulp fibers) such as leaf fibers (for example, Manila hemp, New Zealand hemp, etc.);
Examples of cellulose fibers derived from animals include ascidian cellulose.
These natural cellulose fibers may be used alone or in combination of two or more.

Examples of methods for obtaining regenerated cellulose fibers from the above-mentioned cellulose fibers include the viscose method, the copper ammonia method, and the solvent spinning method (a direct method in which cellulose is not once chemically converted). Examples of regenerated cellulose fibers obtained by the viscose method include viscose rayon, polynosic, modal, and the like. Moreover, examples of the regenerated cellulose fiber obtained by the copper ammonia method include cupra and the like. Further, examples of regenerated cellulose fibers obtained by a solvent spinning method include Lyocell and Tencel. As the regenerated cellulose fiber (b-2), one type of these regenerated cellulose fibers may be used alone, or two or more types may be used in combination. In one embodiment, the regenerated cellulose fibers (b-2) preferably include regenerated cellulose fibers obtained by a viscose method, and more preferably include viscose rayon. When the regenerated cellulose fiber (b-2) contains regenerated cellulose fiber obtained by a viscose method, mechanical strength tends to be good.

In one embodiment, the average fiber diameter of the regenerated cellulose fibers (b-2) is preferably 5 to 30 μm, and the degree of X-ray orientation is preferably 86% or more. Having such an average fiber diameter and degree of X-ray orientation makes it easier for the thermoplastic resin (b-1) to impregnate the regenerated cellulose fiber (b-2). Moreover, the mechanical strength of the obtained molded product also tends to improve.
The average fiber diameter is more preferably from 6 to 20 μm, even more preferably from 7 to 15 μm. Note that the average fiber diameter of the regenerated cellulose fibers (b-2) is the average value of the major diameters of the cross sections of a plurality of fibers observed using a SEM or the like.
Further, it is more preferable that the degree of X-ray orientation is 90% or more. Further, the degree of X-ray orientation of the regenerated cellulose fiber (b-2) can be determined from the formula described in JP-A-9-31744 and JP-A-9-256216.

In one embodiment, the tensile modulus (Young's modulus) of the regenerated cellulose fiber (b-2) may be 10 GPa or more, 13 GPa or more, or 15 GPa or more. The tensile modulus of the regenerated cellulose fiber (b-2) is as described in paragraph number 0038 of JP-A No. 2013-91775, "After storage for 3 weeks in an air conditioner at 23 ° C. and 50 RH, distance between chucks 200 mm, tensile speed 200 mm. /min.

In one embodiment, the average fiber length of the regenerated cellulose fibers (b-2) in the resin composition (B) is preferably 6 to 30 mm, more preferably 6 to 15 mm, and more preferably 6 to 9 mm. It is more preferable that Regenerated cellulose fibers with an average fiber length of 6 to 30 mm are long fibers.

In one embodiment, the resin composition (B) is prepared by melting the above-mentioned thermoplastic resin (b-1) into a fiber bundle made by bundling regenerated cellulose fibers (b-2) aligned in the length direction. It may also contain a composite material of resin (b-1) and regenerated cellulose fiber (b-2) that is impregnated and integrated and then cut. That is, in the composite resin material according to the present embodiment, the resin composition (B) includes the thermoplastic resin (b-1) in a fiber bundle in which the regenerated cellulose fibers (b-2) are aligned in the length direction. The regenerated cellulose fiber bundle (B-1) impregnated with a thermoplastic resin may be included. The details of the thermoplastic resin-impregnated regenerated cellulose fiber bundle (B-1) will be described below.

(Thermoplastic resin-impregnated regenerated cellulose fiber bundle (B-1))
As mentioned above, the thermoplastic resin-impregnated regenerated cellulose fiber bundle (B-1) (hereinafter sometimes simply referred to as "fiber bundle (B-1)") is a regenerated cellulose fiber (b-2) with a length This composite material is obtained by impregnating fiber bundles aligned in the same direction with the thermoplastic resin (b-1) and then cutting them. In one embodiment, the average fiber length of the regenerated cellulose fibers (b-2) in the fiber bundle (B-1) may be 6 to 30 mm, or 6 to 15 mm.

The number of fibers in the fiber bundle of regenerated cellulose fibers (b-2) is preferably 2,000 to 30,000, more preferably 3,000 to 25,000, and more preferably 5,000 to 25. ,000 pieces is more preferable. When the number of fibers is within the above range, the thermoplastic resin (b-1) is likely to be impregnated into the center of the fiber bundle. As a result, when the composite resin material according to this embodiment including the fiber bundle (B-1) is molded, a molded product with a better appearance and better mechanical strength can be easily obtained. Further, during production of the fiber bundle (B-1), manufacturing problems such as breakage of the fiber bundle are less likely to occur.

In one embodiment, the fiber bundle (B-1) can be manufactured by a well-known manufacturing method using a die. Specifically, the manufacturing methods described in JP-A-6-313050, JP-A-2007-176227, JP-A-6-2344, etc. can be applied.

In one embodiment, the ratio of the regenerated cellulose fibers (b-2) to the total mass of the fiber bundle (B-1) is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, and 20 to 40% by mass. % is more preferred. If the ratio of the regenerated cellulose fibers (b-2) to the total mass of the fiber bundle (B-1) is within the above range, the balance between fluidity and mechanical strength in injection moldability tends to be good.

In one embodiment, the proportion of the fiber bundle (B-1) in the resin composition (B) may be 80% by mass or more, or may be 90% by mass or more. Further, the proportion of the fiber bundle (B-1) in the resin composition (B) may be 100% by mass. That is, the resin composition (B) may be composed only of the fiber bundle (B-1).

In one embodiment, the resin composition (B) contains known flame retardants and flame retardant aids, heat stabilizers, lubricants, light stabilizers, antioxidants, and colorants within the range that does not impede the effects of the present invention. , a mold release agent, an antistatic agent, and the like. These components may be contained in the fiber bundle (B-1) or separately from the fiber bundle (B-1).

In one embodiment, the proportion of the resin composition (B) in the composite resin material may be 10 to 90% by mass, or 20 to 80% by mass, based on the total mass of the composite resin material. It may be 30 to 80% by weight.

In one embodiment, the total amount of the aforementioned thermoplastic resin (the total amount of thermoplastic resin (a-2), thermoplastic resin (A-2), and thermoplastic resin (b-1)) in the composite resin material. is preferably 30 to 90% by mass, more preferably 30 to 70% by mass, based on the total mass of the composite resin material. Further, the proportion of regenerated cellulose fibers (b-2) in the composite resin material is preferably 10 to 40% by mass, more preferably 20 to 40% by mass, based on the total mass of the composite resin material. If the total amount of thermoplastic resin and the proportion of regenerated cellulose fiber (b-2) in the composite resin material are within the above ranges, mechanical strength and fluidity during molding tend to be good.

In one embodiment, the composite resin material may be a mixture of pellets (I) containing the plant component-containing material (A) and pellets (II) containing the resin composition (B). That is, the composite resin material may be a mixture of the pellets (I) and the pellets (II) and packaged. When the composite resin material is a mixture of pellets (I) and pellets (II), the mixing ratio of pellets (I) and pellets (II) is such that the material (A) and resin composition (B) in the composite resin material are , can be arbitrarily adjusted within a range that satisfies the above-described preferred embodiments. In one embodiment, the mass ratio of pellets (I) and pellets (II) ((I):(II)) may range from 4:1 to 1:4.

The composite resin material according to this embodiment can contain arbitrary components other than the material (A) and the resin composition (B). That is, it may contain known resin additives depending on various uses.
Examples of resin additives include stabilizers (e.g., antioxidants, ultraviolet absorbers, light stabilizers, etc.), colorants (dyes, pigments, etc.), antistatic agents, and flame retardants (phosphorus-based flame retardants, halogens, etc.). flame retardants, inorganic flame retardants, etc.), flame retardant aids, crosslinking agents, reinforcing materials, nucleating agents, coupling agents, dispersants, antifoaming agents, fluidizing agents, anti-dripping agents, antibacterial agents, preservatives , viscosity modifiers, thickeners, and the like. These may be used alone or in combination of two or more.

The composite resin material according to this embodiment preferably does not contain an inorganic filler such as glass fiber or an inorganic filler. The composite resin material according to this embodiment can provide a molded product with excellent mechanical strength, especially impact strength, even without including the above-mentioned inorganic material as a reinforcing material. Moreover, by not containing these inorganic materials, incineration ash is not generated during thermal recycling, and a composite resin material with a smaller environmental load can be obtained.

<Method for manufacturing composite resin material>
The composite resin material according to the present embodiment can be manufactured by a method including melt-mixing the above-described plant component-containing material (A) and the resin composition (B).
In one embodiment, pellets (I) containing the material (A) and pellets (II) containing the resin composition (B) are each put into an extruder equipped with a heating function and a mixing function, and are melt-mixed. A composite resin material may also be obtained. Especially, the heating temperature is higher than the melting point of the thermoplastic resin (a-2), thermoplastic resin (A-2), thermoplastic starch (A-3), and/or thermoplastic resin (b-1). Not limited. In one embodiment, pellets (I) and pellets (II) may be charged into an extruder and then heated and melted at a temperature of 180 to 230°C, more preferably 190 to 220°C.

[Molded product and its manufacturing method]
The molded product according to this embodiment is obtained by molding the above-mentioned composite resin material. The molded product according to this embodiment may be obtained by injection molding the above-mentioned composite resin material. The molded product according to this embodiment is obtained by molding the above-mentioned composite resin material, and therefore has excellent mechanical strength and a good appearance.

[Application]
The molded article obtained from the composite resin material according to this embodiment has excellent mechanical strength and good appearance, even though it contains a certain amount of plant-derived biomass component. Such molded products can be suitably used, for example, in case parts, vehicle door modules, and the like.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following description.

<Plant component-containing material (A)>
(Resin composition (A-1-1))
A resin composition containing homopolypropylene and rice powder. The ratio of rice powder to the total mass of the resin composition is 70% by mass (manufactured by Biomass Resin Holdings Co., Ltd., product name "Rice Resin R70J-1").
(Resin composition (A-1-2))
A resin composition containing homopolypropylene and cellulose pulp. The proportion of cellulose pulp with respect to the total mass of the resin composition was 54% by mass (manufactured by Daicel Millize Co., Ltd., product name "Celblane PBG150").
(Resin composition (A-1-3))
A resin composition containing homopolypropylene and cellulose pulp. The proportion of cellulose pulp to the total mass of the resin composition was 40% by mass (manufactured by Daicel Millize Co., Ltd., product name "Celblen CP114").

(Resin composition (A-1-4))
A resin composition containing a polyacetal copolymer and cellulose pulp. The proportion of cellulose pulp to the total mass of the resin composition was 30% by mass.
(Adjustment of resin composition (A-1-4))
30% by mass of cellulose pulp was blended with 70% by mass of the following polyacetal copolymer and melt-kneaded in a twin-screw extruder with a cylinder temperature of 200°C to obtain a resin composition (A-1-4).
(Polyacetal copolymer)
Polyacetal copolymer obtained by copolymerizing 96.7% by mass of trioxane and 3.3% by mass of 1,3-dioxolane (melt flow value (measured at 190°C and 2160g load according to ISO 1133): 9g /10min).

(Thermoplastic resin (A-2-1))
High-density polyethylene (HDPE) containing plant-derived ethylene units. The ratio of plant-derived ethylene units to the total ethylene units (100% by mass) is 94% by mass (manufactured by Braskem S.A., product name "SHA7260").

(Thermoplastic starch (A-3-1))
Starch derived from corn and palm palm (manufactured by Sankyo Chemical Industry Co., Ltd., product name "SANKYO GOLDEN STARCH").

<Resin composition (B)>
(Resin composition (B1))
A resin composition obtained by cutting a thermoplastic resin-impregnated fiber bundle made by impregnating homopolypropylene into a fiber bundle of viscose rayon (average fiber diameter (major axis) 18 μm) aligned in the length direction into a length of 7 mm. . The proportion of viscose rayon to the total mass of the resin composition is 40% by mass (manufactured by Polyplastics Co., Ltd., product name "Plastron (registered trademark) LFT PP RF40-02").

(Resin composition (B2))
A resin composition obtained by cutting a thermoplastic resin-impregnated fiber bundle made by impregnating a polyacetal copolymer into a fiber bundle of viscose rayon (average fiber diameter (major axis) of 18 μm) aligned in the length direction into a length of 7 mm. . The proportion of viscose rayon to the total mass of the resin composition was 30% by mass.
(Adjustment of resin composition (B2))
While drawing continuous fibers of viscose rayon (average fiber diameter (length) 18 μm) through a crosshead die, the following polyacetal copolymer was supplied in a molten state to the crosshead die from an extruder set at 220°C. Impregnated into continuous fibers. Thereafter, a strand was created through a shaping die. After cooling the obtained strand, it was cut perpendicularly to the drawing direction to obtain a resin composition (B2).
(Polyacetal copolymer)
Polyacetal copolymer obtained by copolymerizing 96.7% by mass of trioxane and 3.3% by mass of 1,3-dioxolane (melt flow value (measured at 190°C and 2160g load according to ISO 1133): 9g /10min).

<Other materials>
(Resin composition (A'-1): inorganic filler-containing resin composition)
A resin composition containing homopolypropylene and calcium carbonate (particle size 0.5 to 13.5 μm). The ratio of calcium carbonate to the total mass of the resin composition is 60% by mass (manufactured by TBM Co., Ltd., product name: "LIMEX (registered trademark) Pellet PP60-19M").
(Resin composition (B'1))
A resin composition obtained by cutting a glass fiber bundle impregnated with a thermoplastic resin into a length of 11 mm by impregnating a fiber bundle of glass fibers (average fiber diameter 17 μm) with homopolypropylene into a length of 11 mm. The ratio of glass fiber to the total mass of the resin composition is 40% by mass (manufactured by Polyplastics Co., Ltd., product name "Plastron (registered trademark) LFT PP GF40-02").

[Example 1]
As the material (A), 75% by mass of the resin composition (A-1-1) and as the resin composition (B), 25% by mass of the resin composition (B1) were blended, and the mixture was pellet-blended before molding. Composite resin material 1 was obtained. The proportion of plant-derived components in the composite resin material 1 is 52.5% by mass, the proportion of regenerated cellulose fiber (b-2) is 10% by mass, and the total amount of thermoplastic resin is 37.5% by mass. there were.

Next, the composite resin material 1 was molded to obtain a molded product. Various mechanical strengths of the obtained molded products were measured under the following conditions. The appearance was also evaluated under the following conditions. Furthermore, the presence or absence of generation of incineration ash was evaluated under the following conditions. The results are shown in Table 1.
Molding conditions Molding machine: Manufactured by Shibaura Machine Co., Ltd., product name "EC40".
Test piece: ISO tensile test piece. ISO bend test pieces and ISO Charpy impact test pieces were cut from this.
Molding temperature: 200℃.
Mold temperature: 60°C (Examples 1 to 9, Comparative Examples 1 to 6, Reference Examples 1 to 6)
90°C (Example 10, Reference Example 7)

<Evaluation of mechanical strength>
Using the obtained ISO tensile test piece, tensile strength (TS) and tensile elongation (TE) were measured in accordance with ISO527-1, 2. Further, using the obtained ISO bending test piece, bending strength (FS) and bending modulus (FM) were measured in accordance with ISO178. Furthermore, using the obtained ISO Charpy impact test piece, Charpy impact strength was measured in accordance with ISO179.1eA.

<Appearance evaluation of molded products>
The most visually recognized abnormality in the appearance of a molded product is the shade of color. Therefore, after acquiring an image of the molded product sample using a scanner, the image was analyzed using image analysis software ("Image J"). Thereafter, a gray scale density profile was calculated using the gray scale plot profile function in the horizontal direction in an area of 15 mm in width x 3.5 mm in height. Furthermore, the standard deviation was calculated from the profile, and the variation in brightness (shade) was evaluated. The obtained standard deviation value was evaluated according to the following evaluation criteria, and a score of B or higher was considered to be a pass.
A: Standard deviation was 2.5 or less.
B: Standard deviation was more than 2.5 and less than 5.0.
C: Standard deviation was over 5.0.

<Whether or not incineration ash is generated>
The obtained molded product was incinerated at 600° C. in an oxygen atmosphere, and the presence or absence of generation of incineration ash during thermal recycling was evaluated. Cases in which no incinerated ash was generated were defined as "no incinerated ash", and cases in which incinerated ash was generated were defined as "included ash".

[Examples 2 to 10 and Comparative Examples 1 to 6]
A composite resin material was prepared under the same conditions as in Example 1, except that the types and amounts of the plant component-containing material (A) and resin composition (B) were as shown in Tables 1 and 2. A molded article was prepared from the obtained composite resin material under the same conditions as in Example 1. Furthermore, the obtained molded product was evaluated for mechanical strength, appearance evaluation, and presence or absence of incineration ash under the same conditions as in Example 1. The results are shown in Tables 1 and 2.

[Reference examples 1 to 7]
As shown in Table 3, a molded article was prepared under the same conditions as in Example 1 using 100% by mass of the plant component-containing material (A). Furthermore, molded articles were similarly prepared for the inorganic filler-containing resin composition. For each of the obtained molded products, mechanical strength, appearance evaluation, and presence or absence of incineration ash were evaluated under the same conditions as in Example 1. The results are shown in Table 3.

As shown in Tables 1 and 2, the molded articles of Examples 1 to 10 obtained from composite resin materials satisfying the configuration of this embodiment had excellent mechanical strength and good appearance. Surprisingly, by combining material (A) and resin composition (B), the Charpy impact strength can be improved compared to when a resin composition containing glass fiber is combined with material (A). found. The reason for this is thought to be that the fibers contained in the molded article were more uniformly dispersed.
The molded products obtained from the composite resin materials of Comparative Examples 1 to 4 in which the resin composition containing glass fiber was combined with the material (A) were the same as the material (A) and the resin composition containing glass fiber (B) at the time of molding. The appearance was poor because the flow patterns of the particles deviated from each other. Furthermore, incineration ash was also generated during the incineration. In addition, the molded products of Comparative Examples 5 and 6 obtained from composite resin materials in which naturally derived materials containing calcium carbonate, which is a natural inorganic filler, and polypropylene were combined with the resin composition (B) of the present embodiment were Although the mechanical strength and appearance were good, incineration ash was generated.
Furthermore, as shown in Table 3, the molded products molded using each material (A) alone (Reference Examples 1 to 7) were inferior in mechanical strength, particularly Charpy impact strength, to the molded products in the examples. I understand. Furthermore, thermoplastic starch could not be molded by itself.
From the above results, it was found that the composite resin material according to this embodiment can provide a molded product with excellent mechanical strength and good appearance. In addition, since the mechanical strength of the molded product can be improved without adding inorganic fibers or fillers, incineration ash is also generated when the molded product obtained from the composite resin material according to this embodiment is collected and thermally recycled. do not.

The composite resin material according to this embodiment can provide a molded product with excellent mechanical strength and good appearance. Such molded products can be suitably used, for example, in case parts, vehicle door modules, and the like.

Claims (12)

A resin composition (A-1) containing a plant-derived filler (a-1) and a thermoplastic resin (a-2), a thermoplastic resin (A-2) containing monomer units derived from plant raw materials, and a thermoplastic resin at least one plant component-containing material (A) selected from the group consisting of plastic starch (A-3);
A composite resin material comprising a thermoplastic resin (b-1) and a resin composition (B) containing regenerated cellulose fibers (b-2). According to claim 1, the total content of the thermoplastic resin in the composite resin material is 30 to 90% by mass, and the content of the regenerated cellulose fiber (b-2) is 10 to 40% by mass. Composite resin material described. The resin composition (B) is a thermoplastic resin-impregnated regenerated cellulose fiber in which the thermoplastic resin (b-1) impregnates a fiber bundle in which the regenerated cellulose fibers (b-2) are aligned in the length direction. The composite resin material according to claim 1 or 2, comprising a bundle (B-1). The composite resin material according to claim 1 or 2, wherein the average fiber length of the regenerated cellulose fibers (b-2) in the resin composition (B) is 6 to 30 mm. The composite resin material according to claim 1 or 2, wherein the plant-derived filler (a-1) contains at least one selected from crushed seeds and plant fibers. The composite resin material according to claim 1 or 2, wherein the proportion of the plant-derived filler (a-1) to the total mass of the resin composition (A-1) is 30 to 80% by mass. The composite resin material according to claim 1 or 2, wherein the thermoplastic resin (A-2) contains high-density polyethylene containing ethylene units derived from plant materials. The resin composition (B) is a thermoplastic resin-impregnated regenerated cellulose fiber in which the thermoplastic resin (b-1) impregnates a fiber bundle in which the regenerated cellulose fibers (b-2) are aligned in the length direction. including bundle (B-1);
The composite resin according to claim 1 or 2, wherein the proportion of the regenerated cellulose fiber (b-2) to the total mass of the thermoplastic resin-impregnated regenerated cellulose fiber bundle (B-1) is 10 to 50% by mass. material. The composite resin material according to claim 1 or 2, wherein the regenerated cellulose fiber (b-2) contains viscose rayon. The composite according to claim 1 or 2, wherein the composite resin material is a mixture of pellets (I) containing the plant component-containing material (A) and pellets (II) containing the resin composition (B). resin material. The composite resin material according to claim 1 or 2, which is for injection molding. A molded article made of the composite resin material according to claim 1 or 2.