JP2021127391A - Method for producing inorganic substance powder-containing polyolefinic resin molding - Google Patents

Abstract

To provide a production method for producing a molding which has desired physical properties while using a plant-derived polyolefinic resin as a raw material, has good appearance and physical properties, and has no physical variation.SOLUTION: A method for producing an inorganic substance powder-containing polyolefinic resin molding containing a waster plant-derived polyolefinic resin and inorganic substance powder includes: a resin sorting step of sorting one or a plurality of waste plastic raw materials from waste plastic; a preparation step of preparing the waste plastic preparation raw material from the one or the plurality of sorted waste plastic raw materials; and a mixing step of mixing the plant-derived polyolefinic resin and the waste plastic preparation raw material.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a resin molded product. More specifically, the present invention relates to a method for producing a polyolefin-based resin molded product containing an inorganic substance powder containing a waste resin component, an inorganic substance powder, and a plant-derived polyolefin-based resin.

In recent years, biomass-derived materials have been attracting attention against the background of environmental problems such as global warming and oil depletion. Plant-derived polyolefin is a carbon-neutral material that does not depend on petroleum, and its use can contribute to the reduction of carbon dioxide emissions and the prevention of global warming. Plant-derived resins are also renewable resources, and from this point of view, techniques for using plant-derived polyolefins have been proposed.

For example, Patent Document 1 discloses a porous stretched film obtained by stretching a polyethylene resin containing a plant-derived polyethylene resin and a resin composition containing an inorganic filler such as calcium carbonate. In this document, it is proposed to use a polyethylene resin derived from a plant and a polyethylene resin derived from petroleum in a mass ratio of 5:95 to 99: 1. Patent Document 2 discloses a breathable film containing 10 to 65 parts by mass of a petroleum-derived polyolefin resin, 5 to 50 parts by mass of a plant-derived polyethylene-based resin, and 30 to 60 parts by mass of an inorganic filler such as calcium carbonate. Further, Patent Document 3 discloses a multi-layered film containing plant-derived high-density polyethylene or linear low-density polyethylene. Patent Document 4 contains a resin composition containing 100 parts by mass of a polyethylene resin, 5 to 60 parts by mass of cellulose, and 5 to 60 parts by mass of calcium carbonate; Patent Document 5 describes 100 parts by mass of a thermoplastic resin and 5 to 300 parts by mass of cellulose. Each of the antibacterial resin compositions containing a portion is disclosed, and an α-olefin monomer derived from a biomass raw material is used as the resin.

Recycling of resources such as waste plastic is also attracting attention due to growing awareness of environmental issues. The treatment of various types of resin waste materials in general waste and industrial waste has become a social problem, and recycling methods such as fuel substitution and oil conversion are being studied. Above all, in material recycling, environmental problems can be fundamentally solved by using waste materials as raw materials, so it is desired to establish a technical aspect.

For example, Patent Document 6 discloses articles such as containers containing bio-based polyethylene and recycled polyethylene. In this article, the inclusion of recycled polyethylene solves the quality retention problems often associated with bioplastics, even though they are substantially free of virgin petroleum compounds. Further, Patent Document 7 describes a surface layer made of low-density polyethylene derived from a plant and high-density polyethylene derived from fossil fuel, a barrier layer made of an ethylene / vinyl alcohol copolymer and a maleic anhydride-modified polyolefin, and a "recovery layer". A blow-molded multi-layer container is disclosed in which the recovery layer is a container containing the product collected in the factory of the container as a raw material. In the present invention, by providing the recovery layer, not only the recyclability of resources but also the strength of the multi-layer container is enhanced.

International Publication No. 2019/208692 JP-A-2019-119827 Japanese Unexamined Patent Publication No. 2018-154839 Japanese Unexamined Patent Publication No. 2015-203035 Japanese Unexamined Patent Publication No. 2015-205942 Japanese Patent Application Laid-Open No. 2014-508688 Japanese Unexamined Patent Publication No. 2015-199514

As described above, various techniques using plant-derived polyolefin resins have been proposed. However, biopolyethylene and biopolypropylene, which are plant-derived polyolefin resins, are supplied in a limited number of manufacturing plants due to variations in the yield of raw materials such as sugar cane, uneven distribution of production areas, and complexity of the manufacturing process. The types and characteristics of the products are limited. Therefore, unlike conventional polyolefins and the like, which can select products having various resin properties according to the intended use, it may be difficult to obtain raw materials having desired resin properties and manufacture products having various physical properties. rice field. In addition, plant-derived polyolefin resins generally have a problem of high price. In Patent Documents 1 and 4 to 6, inorganic substance powders such as calcium carbonate are blended for the purpose of cost reduction and improvement of printability, colorability and the like. However, in the case of blending a plant-derived polyolefin resin with an inorganic substance powder, it may be difficult to control the physical properties of the product due to variations in physical properties due to poor dispersion and deterioration of mechanical properties and appearance.

In the inventions described in Patent Documents 1 to 3, in consideration of the above problems, a plant-derived resin and a petroleum-derived unused resin are used in combination. The same applies to the invention described in Patent Document 7. This cannot be said to be a technology that fundamentally solves environmental problems because it cannot break away from dependence on oil. In the invention described in Patent Document 6, an article substantially free of virgin petroleum compounds is provided by the combined use of bio-based polyethylene and recycled polyethylene. However, although Patent Document 6 describes in detail the molding method for articles such as containers, there is no disclosure about how the bio-based polyethylene and the recycled polyethylene are specifically blended and mixed, and there is no disclosure of Examples. However, it is only described as "prepared using general compounding methods and mixing methods". According to the findings of the present inventors, even if the recycled plastic (waste plastic) raw material to be blended is mixed with a plant-derived polyolefin resin without being properly selected, a product having good physical characteristics cannot always be obtained. Recycled products are often deteriorated and mixed with impurities, and the base composition is also different. Therefore, if they are not used after being sorted, the processability and physical properties may be deteriorated. The mixing order of each raw material is also important. As will be shown in the examples described later, especially in the case of a resin compound containing an inorganic substance powder, if the mixing order is incorrect, the processability and physical properties may be deteriorated due to poor dispersion.

The present invention has been made in view of the above circumstances, and it is possible to produce a product having desired physical properties while using a plant-derived polyolefin resin as a raw material, and moreover, the physical characteristics vary due to poor dispersion, mechanical properties, and appearance. It is an object of the present invention to provide a manufacturing method in which the dependence on petroleum is suppressed and the characteristics of the molded product can be adjusted without causing a decrease.

As a result of diligent studies, the present inventors have made a plant by using waste plastic, which is an aggregate of plastics having various resin properties, as a raw material, selecting the waste plastic, and mixing and using it according to a desired property. The resin properties of the derived polyolefin resin can be adjusted, and even when an inorganic substance powder such as calcium carbonate is contained, the properties of the resin molded product can be made uniform by uniformly dispersing the inorganic substance powder. The present invention has been completed based on the finding that good appearance and good mechanical properties can be obtained. Specifically, the present invention provides the following.

(1) A method for producing a polyolefin-based resin molded product containing an inorganic substance powder containing a plant-derived polyolefin resin and an inorganic substance powder.
A resin sorting process for sorting one or more waste plastic raw materials from waste plastic,
An inorganic substance comprising a preparation step of preparing a waste plastic preparation raw material from the selected one or a plurality of waste plastic raw materials, and a mixing step of mixing the plant-derived polyolefin resin and the waste plastic preparation raw material. A method for producing a powder-containing polyolefin resin molded product.

(2) The inorganic substance powder-containing polyolefin resin molded product contains 20 to 30% by mass and 10 to 40% by mass of resin components derived from the plant-derived polyolefin resin, the inorganic substance powder, and the waste plastic raw material, respectively. , (1) The method for producing a polyolefin-based resin molded product containing an inorganic substance powder, which is contained in a proportion of 40 to 60% by mass.

(3) The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to (1) or (2), wherein the inorganic substance powder is mixed in the preparation step and / or the mixing step.

(4) The method for producing a polyolefin resin molded product containing an inorganic substance powder according to any one of (1) to (3), wherein the plant-derived polyolefin resin is a plant-derived polypropylene resin and / or a plant-derived polyethylene resin.

(5) The polyolefin-based resin containing an inorganic substance powder according to any one of (1) to (4), wherein the plant-derived polyolefin resin is a plant-derived polypropylene resin having a biomass plasticity of 95% or more and / or a plant-derived polyethylene resin. A method for manufacturing a resin molded body.

(6) The method for producing a polyolefin-based resin molded product containing any of the inorganic substance powders (1) to (5), wherein the inorganic substance powder contains calcium carbonate.

(7) The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to (6), wherein the calcium carbonate is heavy calcium carbonate.

(8) The calcium carbonate is measured by the first calcium carbonate having an average particle size of 0.5 μm or more and less than 2.0 μm measured by the air permeation method by JIS M-8511 and the air permeation method by JIS M-8511. Contains a second calcium carbonate having an average particle size of 2.0 μm or more and less than 9.0 μm.
The mass ratio of the first calcium carbonate to the second calcium carbonate is 90: 10 to 98: 2.
The plant-derived polyolefin resin contains a polyethylene resin and contains
The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to (6) or (7), wherein both the first calcium carbonate and the second calcium carbonate are surface-treated heavy calcium carbonate.

(9) One or more of the resin sorting steps selected from mid-infrared spectroscopy, near-infrared spectroscopy, infrared spectroscopy, Raman spectroscopy, fluorescent X-ray analysis, X-ray diffraction, and TG / DTA. A method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of (1) to (8), which comprises a step of selecting a resin type by an analytical method.

(10) The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of (1) to (9), wherein the preparation step and the mixing step include a kneading step by a twin-screw kneading extruder.

(11) The method for producing an inorganic substance powder-containing polyolefin-based resin molded product according to any one of (1) to (10), wherein the inorganic substance powder-containing polyolefin-based resin molded product is a resin pellet.

(12) An inorganic substance powder-containing polyolefin resin molded article obtained by the method for producing an inorganic substance powder-containing polyolefin resin molded article according to any one of (1) to (11).

According to the present invention, by using waste plastic, it is possible to suppress dependence on petroleum and to produce a molded product having desired physical properties while using a plant-derived polyolefin resin as a raw material. In addition, by providing a resin sorting process for sorting waste plastics and setting the mixing process in two steps, the characteristics of the molded product do not cause variations in physical properties or deterioration of mechanical properties and appearance due to poor dispersion or the like. An adjustable manufacturing method is provided.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not particularly limited thereto.

<1. Manufacturing method of polyolefin resin molded product containing inorganic substance powder-Overview>
The method for producing an inorganic substance powder-containing polyolefin resin molded product according to the present invention (hereinafter, also simply referred to as "manufacturing method") contains a plant-derived polyolefin resin and an inorganic substance powder, and waste plastic raw materials are mixed. This is a method for producing a polyolefin-based resin molded product containing an inorganic substance powder (hereinafter, also simply referred to as “resin molded product”). By mixing the waste plastic raw materials, not only the dependence on petroleum and the cost are reduced, but also the characteristics caused by the waste resin components derived from the waste plastic raw materials are attached to the plant-derived polyolefin resin, and resin molding having various desired physical properties is provided. You will be able to obtain a body. Therefore, in the present invention, the recovered waste plastic is not used as it is, but only the material containing the desired waste resin component is selected and used. In the present invention, the recovered product before sorting is referred to as "waste plastic", and the material after sorting is referred to as "waste plastic raw material" to distinguish between the two. Further, the waste plastic raw material often contains an inorganic substance powder, but in the present invention, the inorganic substance powder in the waste plastic raw material is also counted as the inorganic substance powder in the resin molded product, and one of the resin components is the waste resin. Count as the amount of ingredients. The resin molded product in the present invention preferably contains 20 to 30% by mass, 10 to 40% by mass, and 40 to 60% by mass of resin components derived from a plant-derived polyolefin resin, an inorganic substance powder, and a waste plastic raw material, respectively. It is contained in the ratio of. The production method of the present invention includes a resin sorting step, and a waste plastic raw material containing a desired waste resin component is sorted from the waste plastic.

The production method of the present invention also includes a preparation step of preparing a waste plastic preparation raw material from one or more of the waste plastic raw materials selected in the resin sorting step. Since the waste plastic raw material has undergone various processing and usage histories, resin raw materials having different compositions and characteristics are often mixed even after the resin sorting process. When such a waste plastic raw material is mixed with a plant-derived polyolefin resin by, for example, only crushing, there is a possibility that the physical properties may vary or deteriorate due to poor dispersion. On the other hand, in the present invention, the preparation step is provided, and for example, by melting and kneading the waste plastic raw materials and mixing them once, such dispersion defects can be prevented. In the present invention, the material prepared in this preparation step is referred to as "waste plastic preparation raw material". The waste plastic preparation raw material is preferably pelletized for more uniform mixing and dispersion in the next mixing step.

In the preparation step, a part or all of the inorganic substance powder contained in the resin molded product may be mixed with the waste plastic raw material. In general, resin mixing tends to be good between resins having similar polarities and melt viscosities, but by mixing a predetermined amount of inorganic substance powder in the waste plastic preparation raw material, dispersion in the mixing step described later May be homogenized. Of course, depending on the type and characteristics of the waste plastic raw material used and the plant-derived polyolefin resin, it is possible to mix a part or all of the inorganic substance powder in a mixing step instead of a preparation step.

The waste plastic preparation raw material thus prepared is then mixed with the plant-derived polyolefin resin in the mixing step. Here, among the inorganic substance powders contained in the resin molded product, the portion that was not blended at the end of the preparation step can be mixed together with the resin in this mixing step. Of course, when all the inorganic substance powders are mixed in the preparation step, additional mixing in the mixing step is unnecessary. As will be described in detail later, even when a material already containing a desired amount of the inorganic substance powder is used as the waste plastic raw material, it is not necessary to mix the inorganic substance powder in the preparation step and the mixing step. After such a mixing step, the obtained resin composition can be subjected to molding to obtain a resin molded product having a desired shape and physical properties. Hereinafter, the raw materials and each process used in the production method of the present invention will be described.

<2. Raw materials>
[Plant-derived polyolefin resin]
The plant-derived polyolefin resin used in the present invention includes all polyolefin-based resins produced from plant-derived raw materials, such as plant-derived polyethylene-based resins and plant-derived polypropylene resins. Typical examples include, but are not limited to, plant-derived polyethylene resins produced from ethylene obtained by fermenting biomass derived from sugar cane, corn, etc. and dehydrating the produced ethanol. It may be a copolymer with a plant-derived α-olefin obtained in the same manner, for example, propylene, 1-butene, 1-hexene, 1-octene, etc., or a homopolymer such as propylene can also be used. .. Biological monomers such as lactic acid and small amounts of petroleum-derived monomers may be copolymerized. However, in the present invention, the degree of biomass plastic specified in ISO16620 or ASTM D6866 is preferably 80% or more, more preferably 90% or more, particularly 95% or more of a polyolefin-based resin, particularly derived from a plant having such a degree of biomass plastic. It is preferable to use polypropylene resin and / or plant-derived polyethylene resin. It is also possible to use a plurality of polyolefin resins in combination.

From the viewpoint of availability and cost, it is preferable to include a plant-derived polyethylene-based resin as the polyolefin-based resin. If it is a polyethylene-based resin, for example, the product names "SLH118", "SLH218", "SLH0820 / 30AF", "SHC7260", "SHD7255LSL", "SGE7252", etc. manufactured by Braskem, etc., have various characteristics. Raw materials can be selected from varieties. Examples of the plant-derived polyethylene-based resin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, and ethylene-α-olefin copolymers (for example, ethylene-propylene copolymers). However, it is not limited to these. For example, the density may be ^{0.90 to 0.97 g / cm 3} , particularly 0.91 to 0.93 g / cm ³ , or 0.94 to 0.96 g / cm ³ . The melt flow rate (MFR) is not particularly limited, and an appropriate range can be selected according to the application, the processing method, and the type and characteristics of the waste resin component used in combination. For example, when the waste plastic preparation raw material has a high viscosity, the MFR of the plant-derived polyethylene resin is relatively high, about 0.5 to 5.0 g / 10 minutes, particularly 2.0 to 4.0 g / 10 minutes. Use a viscous variety; when the waste plastic preparation raw material has a low viscosity, the MFR is 4.0 to 10.0 g / 10 minutes, especially 5.0 to 8.0 g / 10 minutes, which is a relatively low viscosity. It is possible to make a selection such as using the varieties of.

[Inorganic powder]
The inorganic substance powder is not particularly limited, and is, for example, carbonates such as calcium, magnesium, aluminum, titanium, iron, and zinc, sulfates, silicates, phosphates, borates, oxides, or water thereof. Examples include powdered Japanese products, and specific examples thereof include calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, magnesium hydroxide, and silicic acid. Aluminum, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous soil, sericite, silas, calcium sulfite, sodium sulfate, titanic acid Examples thereof include potassium, bentonite, wollastonite, dolomite, graphite and the like. These may be synthetic or derived from natural minerals, and they may be contained alone or in combination of two or more.

Further, the shape of the inorganic substance powder is not particularly limited, and may be in the form of particles, flakes, granules, fibers, or the like. Further, it may be in the form of particles, which may be spherical as generally obtained by a synthetic method, or may have an indefinite shape as obtained by pulverizing the collected natural minerals. ..

As these inorganic substance powders, calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, magnesium hydroxide and the like are preferable, and those containing calcium carbonate are particularly preferable. .. Further, the calcium carbonate is either so-called light calcium carbonate prepared by a synthetic method or so-called heavy calcium carbonate obtained by mechanically crushing and _{classifying a natural raw material containing CaCO 3 as a main component such as limestone.} It may be a combination of these.

However, in the present invention, it is preferable to use an inorganic substance powder containing heavy calcium carbonate. Here, heavy calcium carbonate is obtained by mechanically crushing and processing natural limestone or the like, and is clearly distinguished from synthetic calcium carbonate produced by a chemical precipitation reaction or the like. The pulverization method includes a dry method and a wet method, and the dry method is preferable.

The heavy calcium carbonate particles, for example, unlike the light calcium carbonate produced by the synthetic method, are characterized by surface irregularity and a large specific surface area due to the particle formation performed by the pulverization treatment. Since the heavy calcium carbonate particles have such irregular shape and large surface area, the heavy calcium carbonate particles have more contact interfaces with the thermoplastic resin when blended in the thermoplastic resin. Has and is effective for uniform dispersion.

Although not particularly limited, the specific surface area of the heavy calcium carbonate particles ^{is about 3,000 cm 2} / g or more and 35,000 m ² / g or less, although it depends on the average particle size. desired. The specific surface area referred to here is based on the air permeation method. When the specific surface area is within this range, the deterioration of workability of the obtained molded product tends to be suppressed.

Further, the indeterminate form of the heavy calcium carbonate particles can be expressed by the low degree of spheroidization of the particle shape, and is not particularly limited, but specifically, the roundness is 0.50. More than 0.95 or less, more preferably 0.55 or more and 0.93 or less, still more preferably 0.60 or more and 0.90 or less. When the roundness of the heavy calcium carbonate particles is within the range, the strength and moldability of the molded product are also appropriate. Here, the roundness can be expressed by (projected area of particles) / (area of a circle having the same perimeter as the projected perimeter of particles). The method for measuring the roundness is not particularly limited, and for example, the projected area of the particles and the projected peripheral length of the particles may be measured from a micrograph, or a generally commercially available image analysis software may be used.

Further, the surface may be surface-modified according to a conventional method in order to enhance the dispersibility or reactivity of the inorganic substance powder. Examples of the surface modification method include a physical method such as plasma treatment and a method of chemically surface-treating the surface with a coupling agent or a surfactant. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. The surfactant may be any of anionic, cationic, nonionic and amphoteric, and examples thereof include higher fatty acids, higher fatty acid esters, higher fatty acid amides and higher fatty acid salts. On the contrary, it may contain an inorganic substance powder that has not been surface-treated.

The inorganic substance powder such as heavy calcium carbonate particles is not particularly limited, but the average particle size thereof is preferably 0.5 μm or more and 9.0 μm or less, and more preferably 0.7 μm or more and 6.0 μm or less. More preferably, it is 1.0 μm or more and 4.0 μm or less. The average particle size of the inorganic substance powder described in the present specification refers to a value calculated from the measurement result of the specific surface area by the air permeation method according to JIS M-8511. As the measuring device, for example, a specific surface area measuring device SS-100 manufactured by Shimadzu Corporation can be preferably used. When the average particle size is larger than 9.0 μm, for example, when a sheet-shaped molded product is formed, the inorganic substance powder protrudes from the surface of the molded product and falls off, depending on the layer thickness of the molded product. There is a risk of damage to the surface properties and mechanical strength. In particular, it is preferable that the particle size distribution does not contain particles having a particle size of 45 μm or more. On the other hand, if the particles become too fine, the viscosity may increase remarkably when kneaded with the above-mentioned resin, which may make it difficult to manufacture a molded product. Therefore, the average particle size is preferably 0.5 μm or more.

As described above, in the present invention, it is preferable to use calcium carbonate as the inorganic substance powder. More preferably, the calcium carbonate is obtained by the first calcium carbonate having an average particle size of 0.5 μm or more and less than 2.0 μm measured by the air permeation method according to JIS M-8511, and the air permeation method according to JIS M-8511. It contains a second calcium carbonate having a measured average particle size of 2.0 μm or more and less than 9.0 μm. This makes it possible to improve the surface properties of the molded product and the physical properties such as printability and blocking property. The mass ratio of the first calcium carbonate to the second calcium carbonate is preferably 90: 10 to 98: 2, particularly about 92: 8 to 95: 5. Further, it is preferable that both the first calcium carbonate and the second calcium carbonate are surface-treated heavy calcium carbonate.

[Waste plastic raw material]
In the present invention, a waste plastic raw material is used together with the above-mentioned plant-derived polyolefin resin and inorganic substance powder. By containing the waste resin component derived from the waste plastic raw material in the polyolefin resin molded product containing an inorganic substance powder, the dependence on petroleum is suppressed, and the plant-derived polyolefin resin has desired physical properties as a raw material. It is possible to manufacture a resin molded product, and it is also possible to prevent deterioration of physical properties due to poor dispersion.

As described above, the waste resin component is added to give various physical properties to the resin molded product and to prevent deterioration of physical properties due to poor dispersion. Therefore, the thermoplasticity is not particularly limited, and various materials should be used depending on the use and function of the resin molded product, the characteristics of the plant-derived polyolefin resin to be mixed, the recovery status of waste plastic, and the like. Can be done. For example, polyolefin resins such as polyethylene resins, polypropylene resins, polymethyl-1-pentene, and ethylene-cyclic olefin copolymers; ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, and ethylene-methacrylic acid copolymers. Functional groups such as polymers, metal salts of ethylene-methacrylic acid copolymers (ionomers), ethylene-acrylic acid alkyl ester copolymers, ethylene-methacrylic acid alkyl ester copolymers, maleic acid-modified polyethylenes, maleic acid-modified polypropylenes, etc. Containing polyolefin resin; polyamide resin such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12; fragrance of polyethylene terephthalate and its copolymer, polyethylene naphthalate, polybutylene terephthalate, etc. Thermoplastic polyester resins such as aliphatic polyester resins such as group polyester resins, polybutylene succinates and polylactic acid; polycarbonate resins such as aromatic polycarbonates and aliphatic polycarbonates; atactic polystyrenes, syndiotactic polystyrenes, acrylonitriles- Polystyrene-based resins such as styrene (AS) copolymers and acrylonitrile-butadiene-styrene (ABS) copolymers; polyvinyl chloride-based resins such as polyvinyl chloride and vinylidene chloride; polyphenylene sulfides; polyether sulfone and polyether ketones. , Polyether-based resins such as polyether ether ketones. The waste plastic raw material used in the present invention may contain these resins alone or may contain two or more of these resins.

In the present invention, various waste plastic raw materials can be used as described above, but those containing a polyolefin resin are preferable in consideration of compatibility with a plant-derived polyolefin resin and economic efficiency. Polyolefin-based resins are widely used in the market, and their recycling can greatly contribute to solving environmental problems.

Here, the polyolefin-based resin is a polyolefin-based resin containing an olefin component unit as a main component, and specifically, as described above, polypropylene-based resin, polyethylene-based resin, other polymethyl-1-pentene, ethylene- Examples thereof include cyclic olefin copolymers and the like, as well as mixtures of two or more of them. The above-mentioned "main component" means that the polyolefin component unit contains 50% by mass or more of the olefin component unit, and the content thereof is preferably 75% by mass or more, more preferably 85% by mass. % Or more, more preferably 90% by mass or more. The method for producing the polyolefin resin used in the present invention is not particularly limited, and can be obtained by any of a method using a Ziegler-Natta catalyst, a metallocene catalyst, a radical initiator such as oxygen or peroxide, or the like. It may be a catalyst.

Examples of the polypropylene-based resin include resins having a propylene component unit of 50% by mass or more, and examples thereof include propylene homopolymers and copolymers with other α-olefins copolymerizable with propylene. Other α-olefins copolymerizable with propylene include, for example, ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene. , 1-Heptene, 3-Methyl-1-hexene and the like, α-olefins having 4 to 10 carbon atoms are exemplified. Propylene homopolymers include any of isotactics, syndiotactics, atactics, hemiisotactics and linear or branched polypropylenes exhibiting varying degrees of stereoregularity. Further, the copolymer may be a random copolymer or a block copolymer, and may be a ternary copolymer as well as a binary copolymer. Specifically, for example, an ethylene-propylene random copolymer, a butene-1-propylene random copolymer, an ethylene-butene-1-propylene random ternary copolymer, an ethylene-propylene block copolymer and the like can be exemplified. .. The other olefin copolymerizable with propylene in the copolymer is 25% by mass or less, particularly 15% by mass or less, when the total mass of the polyolefin resin molded product containing the inorganic substance powder is 100% by mass. It is preferably contained in a proportion, and the lower limit value can be, for example, 0.3% by mass. Moreover, these polypropylene-based resins may be alone or a mixture of two or more kinds.

Examples of the polyethylene-based resin include resins having an ethylene component unit of 50% by mass or more. For example, high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene, and linear low-density polyethylene (LLDPE). ), Ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-propylene-butene 1 copolymer, ethylene-butene 1 copolymer, ethylene-hexene 1 copolymer, ethylene-4 methylpentene 1 Examples thereof include polymers, polyethylene-octene 1 copolymers, and the like, and mixtures of two or more thereof. In particular, when a plant-derived ethylene resin is used as the plant-derived polyolefin resin, it is preferable to use a waste plastic raw material containing a polyethylene resin.

In addition, polyethylene having a density of 0.942 g / cm ³ or more is usually "high density polyethylene (HDPE)", and polyethylene having a density of ^{0.930 g / cm 3} or more and less than 0.942 g / cm ^{3 is usually "medium".} "High density polyethylene", polyethylene ^{having a density of 0.910 g / cm 3} or more and less than 0.930 g / cm ³ is usually "low density polyethylene (LDPE)", polyethylene having a density of less than ^{0.910 g / cm 3 is usually} It is called "ultra-low density polyethylene (ULDPE)". Further, "linear low density polyethylene (LLDPE)" is usually a density of less than 0.911 g / cm ³ or more 0.940 g / cm ^3, preferably 0.912 g / cm ³ or more 0.928 g / cm less than ³ Has a density of.

The waste plastic raw material used in the present invention may contain raw materials other than the above resin components. Generally, commercially available plastic products contain a small amount of additives such as anti-aging agents and processing aids, but these additives usually do not adversely affect the molded product obtained by the production method of the present invention. Some plastic products are filled with inorganic powder, and such composites can also be used in the present invention. In particular, the waste plastic containing the inorganic substance powder as described above is suitable as a waste plastic raw material in the present invention. For example, by mixing a waste plastic raw material containing 60 to 80% by mass of a resin component and 40 to 20% by mass of an inorganic substance powder with a plant-derived polyolefin resin having a mass of 1/3 of that, the waste resin component 45 to 45 to A resin molded product composed of 60% by mass, 30 to 15% by mass of an inorganic substance powder, and 25% by mass of a plant-derived polyolefin resin can be produced. In this example, the inorganic substance powder is not newly added, but the inorganic substance powder previously contained in the waste plastic raw material is remixed in the preparation step and uniformly dispersed. Of course, it is also possible to mix the inorganic substance powder together with such a waste plastic raw material in the preparation step and / or the mixing step to further produce a resin molded product having a high content of the inorganic substance powder.

The polyolefin-based resin molded product containing the inorganic substance powder produced in the present invention contains the above-mentioned waste resin component, the inorganic substance powder, and the plant-derived polyolefin resin in an amount of 40 to 60% by mass, 10 to 40% by mass, and 20 to 0, respectively. It is contained in a proportion of 30% by mass. Of course, these contents can be arbitrarily changed according to the purpose of use of the resin molded product, the processing method, and the like. For example, in order to change the hardness of the molded product, the content of the inorganic substance powder may be in the range of 10 to 25% by mass, 20 to 30% by mass, 25 to 40% by mass, etc., depending on the desired physical properties and processability. The mass ratio of the waste resin component to the plant-derived polyolefin resin can be changed, for example, the content of the waste resin component can be set to about 40 to 50% by mass or about 50 to 60% by mass.

<3. Each process>
[Resin sorting process]
In the production method of the present invention, a waste plastic raw material containing the above-mentioned desired waste resin component is selected from the waste plastic. The target and method of sorting are not particularly limited, and can be arbitrarily set according to the type of desired waste resin component, the characteristics of the plant-derived polypropylene resin to be mixed, and the properties of the waste plastic. If the composition of the waste plastic is unknown, one or more selected from mid-infrared spectroscopy, near-infrared spectroscopy, infrared spectroscopy, Raman spectroscopy, X-ray fluorescence analysis, X-ray diffraction, and TG / DTA. It is preferable to select the resin type by the analysis method of the above, and if possible, analyze the content of the inorganic substance powder or the like. For example, a small amount of sample is sampled for each lot of waste plastic, the type of resin contained by infrared spectroscopy is analyzed, the type of inorganic substance powder is analyzed by X-ray diffraction or fluorescent X-ray analysis, and then TG / DTA analysis is performed. Estimate the content of each component in combination. Based on these analysis results, a desired waste plastic raw material can be selected. Even when the composition of the waste plastic is clear, such a resin sorting step is important from the viewpoint of preventing the inclusion of impurities. Waste plastic raw materials may be selected based on physical characteristics such as hardness and strength.

In the resin sorting step, it is also possible to select a waste plastic raw material having characteristics such as melt viscosity similar to those of the plant-derived polyolefin resin to be mixed. This makes it easy to prevent defects in mixing and dispersion, especially in the mixing step. For example, the melt flow rate of waste plastic may be measured for each lot, and a lot having a melt flow rate equivalent to that of the plant-derived polyolefin resin may be used. Generally, the melt flow rate of polyethylene resin is measured at 190 ° C., and the melt flow rate of polypropylene resin is measured at 230 ° C. Therefore, when comparing the measured value in this sorting process with the catalog value, the measured temperature is measured. Attention should be paid to the effects of differences.

[Crushing process]
The waste plastic raw material selected as described above is then subjected to a preparation step, and is preferably pulverized to a size of about several mm square prior to mixing. There is no particular limitation on the size of the crushed product, for example, 1 to 10 mm square, 1 to 5 mm square, 2 to 3 mm square, 5 to 8 mm square, etc., the type and shape of the target molded product, and the waste material used. It can be pulverized to a desired size depending on the characteristics of the device and the device. The crusher is not particularly limited, and is a crusher using a crushing medium such as an impact type crusher, a vibrating ball mill or a ball mill typified by a planetary ball mill, a roller mill, a jet mill, a disc type, a pin type, etc. A bead mill represented by the above, a high-pressure homogenizer, a medialess disperser represented by an ultrasonic disperser, etc. can be used.

As the pulverization method, either a dry method or a wet method can be used, and the dry method is economically preferable, and the wet method is preferable in that water washing can be performed at the same time. In recycling the resin waste material, it is preferable to wash the waste material, but when it is crushed by a wet method, it can be washed with water at the same time. In addition, it is preferable to wash with water after crushing or during crushing while stirring with a washing dehydrator or the like from the viewpoint of washing efficiency. For example, the recycling efficiency can be improved by combining the dry method and the wet method, performing coarse pulverization by the dry method, and then finely pulverizing by the wet method. After pulverization, the foreign matter may be removed by using a commercially available foreign matter removing device or the like.

[Preparation process]
In the preparation process, a waste plastic preparation raw material is prepared from the waste plastic raw material. The preparation method is not particularly limited, but it is preferable to prepare by mixing one or more selected waste plastic raw materials. Since waste plastics often have different melting characteristics depending on the lot or location, even if only one type of waste plastic raw material is selected, this preparation process eliminates the variation in the characteristics of the waste plastic raw material and mixes it in the subsequent mixing process. -There is an advantage that the dispersion is made uniform. This step is extremely important, especially when waste plastic raw materials having different compositions are used. As described above, a part or all of the inorganic substance powder can be mixed in this step, but if the waste plastic preparation raw material is homogenized in the preparation step, the subsequent mixing step can proceed smoothly.

The mixing method is not particularly limited, but the melt mixing method is preferable. As the mixing device, various devices such as a general extruder, a kneader, and a Banbury mixer can be used, but the use of an extruder is preferable. Since high shearing force is applied in extrusion kneading, a more homogeneous waste plastic preparation raw material can be prepared.

Examples of the extruder include a twin-screw kneading extruder (same-direction rotating twin-screw kneading extruder, different-direction rotating twin-screw kneading extruder), a kneader type extruder, and a single-screw extruder. Of these, the kneader type extruder and the twin-screw kneading extruder are used from the viewpoints that the melt mass flow rate at the time of kneading the waste plastic raw material tends to be high, the variation in the melt mass flow rate is suppressed, and the moldability is improved. A twin-screw kneading extruder is particularly preferable.

When an extruder is used in this preparation step, it is also possible to select waste plastic preparation raw materials based on the discharge amount. This can be said to be a "resin property sorting process" that is performed separately from the above resin sorting process. Based on the fact that the discharge amount during extrusion reflects the melting characteristics of the kneaded product, the waste plastic preparation raw material is used as the melt viscosity, etc. It is an operation to sort according to the characteristics of. Even if the waste plastic raw materials are selected in advance as described above, their melting characteristics may vary. However, if a lot having a melt viscosity close to that of a plant-derived polyolefin resin is selected based on the resin characteristics, the following mixing is performed. Allows for more homogeneous mixing in the process.

[Pellet molding process]
A pellet molding step can be added after the preparation step. For example, a pelletizer is provided at the tip of the extruder to pellet the extruded waste plastic preparation raw material. By pelletizing, it becomes possible to more uniformly mix and disperse with the plant-derived polyolefin resin in the next mixing step. The shape of the pellet is not particularly limited, and examples thereof include a cylinder, a sphere, and an elliptical sphere. The size of the pellet may be appropriately set according to the shape, but for example, in the case of a spherical pellet, the diameter may be 1 to 10 mm. In the case of an elliptical spherical pellet, the pellet has an elliptical shape with an aspect ratio of 0.1 to 1.0, and may be 1 to 10 mm in length and width. In the case of cylindrical pellets, the diameter may be in the range of 1 to 10 mm and the length may be in the range of 1 to 10 mm.

[Mixing process]
The waste plastic preparation raw material obtained as described above is then mixed with the plant-derived polyolefin resin in the mixing step. Inorganic powder may be mixed in this step. The mixing method and mixing apparatus in this step are not particularly limited, but can be carried out in the same manner as in the preparation step.

[Molding process]
In the production method of the present invention, the mixture obtained as described above is then subjected to a molding step and processed into a product or a semi-finished product. It is preferable to mold the resin pellets once. The method and apparatus used for pelletization are not particularly limited, and for example, it can be carried out in the same manner as the pellet molding step after the above-mentioned preparation step.

Various molded articles can be produced using the pellets thus molded or by using a mixture that has not been pelletized. The present invention also includes an inorganic substance powder-blended resin molded product obtained by the above-mentioned production method. As a molding method, a usual method can be used, for example, an injection molding method, a foam injection molding method, an injection compression molding method, an extrusion molding method, a blow molding method, an inflation molding method, a press molding method, a calendar molding method. , A vacuum molding method, and any known molding method such as an in-mold molding method, a gas press molding method, a two-color to multicolor molding method, and a sandwich molding method can be adopted. Further, when molding into a sheet or film, it may be stretched in a uniaxial or biaxial direction or a multiaxial direction (stretching by an inflation method, a tubular method, etc.) at the time of molding or after the molding. It is possible. It may be multilayered with other resin compositions. In the production method of the present invention, a foaming agent is contained in the mixing step, and conventionally known foaming methods such as injection foaming, extrusion foaming, liquid phase foaming such as foaming blow, bead foaming, batch foaming, press foaming, etc. It is also possible to perform foam molding using solid phase foaming such as normal pressure secondary foaming.

<4. Resin molded body>
The inorganic substance powder-blended resin molded product according to the present invention is a resin molded product obtained by the above-mentioned production method of the present invention. Preferably, the plant-derived polyolefin resin, the inorganic substance powder, and the resin component derived from the waste plastic raw material are contained in the proportions of 20 to 30% by mass, 10 to 40% by mass, and 40 to 60% by mass, respectively. The resin molded product of the present invention may also contain other components other than these, for example, a foaming agent as described above, and a thermoplastic resin or fiber other than those described above. Although it does not lead to a solution to environmental problems, it is also possible to mix or laminate, for example, a thermoplastic resin derived from petroleum to form a composite material.

<Other ingredients>
It is possible to add other thermoplastic resins to the inorganic substance powder-blended resin molded product according to the present invention, if necessary, but the amount of the other thermoplastic resins greatly affects the dependence on petroleum. It is preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably no other thermoplastic resin is blended with respect to the total resin component. Examples of the thermoplastic resin include polyolefin resins such as polyethylene resins, polypropylene resins, polymethyl-1-pentene, and ethylene-cyclic olefin copolymers; ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, and ethylene. -Methacrylic acid copolymer, metal salt of ethylene-methacrylic acid copolymer (ionomer), ethylene-acrylic acid alkyl ester copolymer, ethylene-methacrylic acid alkyl ester copolymer, maleic acid-modified polyethylene, maleic acid-modified polypropylene Functional group-containing polyolefin resins such as Nylon-6, Nylon-6,6, Nylon-6,10, Nylon-6,12 and other polyamide resins; Polyethylene terephthalate and its copolymers, polyethylene naphthalate, polybutylene, etc. Aromatic polyester resins such as terephthalate, for example, poly lactic acid such as poly L-lactic acid, poly D-lactic acid, poly DL-lactic acid, poly 3-hydroxybutyric acid, poly 3-hydroxyvaleric acid, poly 3-hydroxyhexanoic acid, Fats such as poly 3-hydroxybutyrate-co-3-hydroxyhexanoate, poly 3-hydroxyoctanoic acid, poly 3-hydroxydecanoic acid, poly 4-hydroxybutyric acid, poly 4-hydroxyvaleric acid, polybutylene succinate, etc. Thermoplastic polyester-based resins such as group polyester resins; Polycarbonate resins such as aromatic polycarbonates and aliphatic polycarbonates; atactic polystyrenes, syndiotactic polystyrenes, acrylonitrile-styrene (AS) copolymers, acrylonitrile-butadiene-styrene (ABS) ) Polypolymer-based resins such as copolymers; Polyvinyl chloride-based resins such as polyvinyl chloride and vinylidene chloride; Polyphenylene sulfides; Polyether-based resins such as polyether sulfone, polyether ketones, and polyether ether ketones. ..

Further, the polyolefin-based resin molded product containing the inorganic substance powder according to the present invention may be blended with other additives as an auxiliary agent, if necessary. Other additives include, for example, plasticizers, colorants, lubricants, coupling agents, fluidity improvers, dispersants, antioxidants, UV absorbers, flame retardants, stabilizers, antistatic agents, foaming agents and the like. May be blended. These additives may be used alone or in combination of two or more. In the inorganic substance powder-blended resin molded body according to the present invention, the amount of other additives added is, for example, when the total mass of the inorganic substance powder-blended resin molded body is 100%, each of these additives is 0. It is desirable that the mixture is blended in a proportion of about 5% by mass and 10% by mass or less in the total amount of the other additives.

In the present invention, these additives may be mixed in the preparation step or may be mixed in the mixing step. It is also possible to use a waste plastic raw material containing these additives. Hereinafter, among these additives, those considered to be important will be described with examples, but the present invention is not limited to these.

Examples of the plasticizer include lactic acid, a lactic acid oligomer having a weight average molecular weight of 3,000 or less, and branched polylactic acid (see, for example, International Publication WO2010 / 082639).

As the colorant, any known organic pigment, inorganic pigment or dye can be used. Specifically, organic pigments such as azo-based, anthraquinone-based, phthalocyanine-based, quinacridone-based, isoindolinone-based, geoosazine-based, perinone-based, quinophthalone-based, and perylene-based pigments, ultramarine blue, titanium oxide, titanium yellow, and iron oxide. Examples thereof include inorganic pigments such as (valve handle), chromium oxide, zinc flower, and carbon black.

Examples of the lubricant include fatty acid-based lubricants such as stearic acid, hydroxystearic acid, composite stearic acid, and oleic acid, aliphatic alcohol-based lubricants, stearoamide, oxystearoamide, oleylamide, elcilamide, ricinolamide, behenamide, and methylol. Adipose amide lubricants such as amides, methylene bisstearoamides, methylene bisstearobehenamides, higher fatty acid bisamide acids, complex amides, stearate-n-butyl, methyl hydroxystearate, polyhydric alcohol fatty acid esters, Examples thereof include saturated fatty acid esters, aliphatic ester-based lubricants such as ester-based waxes, fatty acid metal soap-based lubricants, and the like.

As the antioxidant, a phosphorus-based antioxidant, a phenol-based antioxidant, and a pentaerythritol-based antioxidant can be used. Phosphorus-based, more specifically, phosphorus-based antioxidant stabilizers such as phosphite ester and phosphoric acid ester are preferably used. Examples of the phosphorous acid ester include triphenyl phosphite, trisnonylphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, and other phosphorous acid triesters, diesters, and monoesters. Can be mentioned.

Examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2-ethylphenyldiphenyl phosphate and the like. These phosphorus-based antioxidants may be used alone or in combination of two or more.

Examples of phenolic antioxidants include α-tocopherol, butylhydroxytoluene, cinapyl alcohol, vitamin E, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2-. t-Butyl-6- (3'-t-Butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenylacrylate, 2,6-di-t-butyl-4- (N, N-dimethyl) Aminomethyl) phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester, and tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane Etc. are exemplified, and these can be used alone or in combination of two or more kinds.

The flame retardant is not particularly limited, and for example, a non-phosphorus non-halogen flame retardant such as a halogen flame retardant, a phosphorus flame retardant, or a metal hydrate can be used. Examples of the halogen-based flame retardant include halogenated bisphenol compounds such as halogenated bisphenyl alkane, halogenated bisphenyl ether, halogenated bisphenyl thioether, and halogenated bisphenyl sulfone, brominated bisphenol A, and brominated bisphenol S. Examples of phosphorus-based flame retardants such as bisphenol-bis (alkyl ether) -based compounds such as chlorinated bisphenol A and chlorinated bisphenol S include tris (diethylphosphinic acid) aluminum, bisphenol A bis (diphenyl phosphate), and triarylisopropyl phosphate. Examples of metal hydrates include isomers, cresildi 2, 6-xylenyl phosphate, aromatic condensed phosphate, and the like, such as aluminum trihydrate, magnesium dihydride, or a combination thereof. These can be used alone or in combination of two or more. Further, for example, antimony oxide such as antimony trioxide and antimony pentoxide, zinc oxide, iron oxide, aluminum oxide, molybdenum oxide, titanium oxide, calcium oxide, magnesium oxide and the like can be used in combination as a flame retardant aid. ..

The foaming agent is a material that is mixed or press-fitted with a waste plastic raw material that has been melted in a melt-kneader and undergoes a phase change from a solid to a gas, a liquid to a gas, or the gas itself, and is mainly a foaming ratio of a foamed sheet. Used to control (foam density). As for the foaming agent dissolved in the waste plastic raw material, the foaming agent that is liquid at room temperature changes its phase to a gas depending on the resin temperature and dissolves in the molten resin, and the foaming agent that is gas at room temperature does not undergo a phase change and dissolves in the molten resin as it is. When the molten resin is extruded from the extrusion die, the foaming agent dispersed and dissolved in the molten resin expands inside the extruded product because the pressure is released, and a large number of fine closed cells are formed to obtain a foamed molded product. .. The foaming agent secondarily acts as a plasticizer that lowers the melt viscosity of the waste plastic raw material, and can lower the temperature for bringing it into a plasticized state.

[Shape and application of resin molded product]
The shape and the like of the inorganic substance powder-blended resin molded product according to the present invention are not particularly limited, and may be of various forms. The resin molded body of the present invention may be, for example, a sheet, a film, a bag-like material, a container, or the like, particularly an inflation sheet or an inflation film. Since the resin molded product of the present invention is less dependent on petroleum, its use can contribute to solving environmental problems. Further, since it can have desired physical properties depending on the selection of waste plastic raw materials, it is useful as consumables in various fields such as various daily necessities, automobile parts, electric / electronic parts, and building materials.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

[Example 1, Comparative Examples 1 to 3]
Using the following raw materials, a filamentous molded body having a diameter of 1.8 mm was prototyped.
-Plant-derived resin-A: Linear low-density polyethylene resin C4-LL118 manufactured by Braskem (density: 0.916, MFR: 1.0 g / 10 minutes)
-Plant-derived resin-B: High-density polyethylene resin SHC7260 manufactured by Braskem (density: 0.959, MFR = 7.2 g / 10 minutes)
-Calcium carbonate-A: Ryton BS-0 surface treated by Bikita Powder Industry Co., Ltd., average particle size 1.00 μm (first calcium carbonate) measured by the air permeation method according to JIS M-8511.
-Waste plastic: "LIMEX" (manufactured by TBM Co., Ltd .: registered trademark) and each of the 12 types of scraps produced when trial production of similar products were dry-ground in a planetary ball mill, and then 2 mm square or less in a wet bead mill. Each crushed product finely crushed to size (hereinafter referred to as "waste plastic No. 1 to 12")

Prior to trial production, waste plastic No. Infrared spectroscopic analysis, X-ray diffraction, fluorescent X-ray analysis, and TG / DTA measurement were performed for each of 1 to 12, and the rough composition of each waste plastic was grasped. The results are shown in Table 1. No inorganic substances other than calcium carbonate were detected in any of the waste plastics.

Based on the results shown in Table 1, the waste plastic No. 1 to 6 were selected (resin sorting step) and used in Example 1. The composition of the prototype in each example (comparative example) is shown in Table 2 below.

In Example 1, the waste plastic No. 100 parts by mass of each of 1 to 6 is kneaded at 200 ° C. using a small twin-screw kneading extruder (φ25 mm, L / D = 41) rotating in the same direction, extruded into water with strands (first stage extrusion: preparation process), and cooled. , Cut to make pellets. Next, 600 parts by mass of the obtained pellets and 200 parts by mass of the plant-derived resin-A were introduced into a twin-screw extruder having a screw diameter of 15 mm (second-stage extrusion: mixing step, plant-derived polyolefin resin: carbonic acid. Calcium: mass ratio of waste resin component = 25:30:45), extruded from a die having a diameter of 3 mm at a set temperature of 200 ° C. and a discharge rate of 1.0 kg / hr. This was taken up at 5 m / min by a taking-up device through a water tank at 40 ° C. to form a filament. The diameter of the cross section of the obtained filament was measured and found to be in the range of 1.7 to 1.9 mm.

In Comparative Examples 1 to 3, 70 parts by mass of the plant-derived resin-A and / or B and 30 parts by mass of calcium carbonate-A were used to prepare pellets under the same conditions as in the first-stage extrusion of Example 1. bottom. A filament was formed from each of the obtained pellets under the same conditions as in the second step extrusion, and the diameter of the cross-sectional area thereof was measured. The measurement results are shown in Table 2.

As shown in Table 2, in Example 1 using the waste plastic preparation raw material according to the present invention, the diameter of the filament cross section was within the range of the target value ± 0.1 mm. On the other hand, in Comparative Examples 1 to 3 excluding the waste plastic preparation raw materials, the cross-sectional diameter varied widely even though the mixing of the raw materials was completed by the first-stage extrusion. In Comparative Example 3 in which the plant-derived resins-A and B having different characteristics such as density were used in combination, some improvement was observed, but the result was still inferior to that in Example 1. It was shown that the inclusion of the waste plastic preparation raw material makes it possible to produce a molded product having no variation in physical characteristics while using a plant-derived polyolefin resin as a raw material.

[Example 2]
In this embodiment, as the waste plastic raw material, the waste plastic No. 7 and 8 were selected (resin sorting step). In addition, the following calcium carbonate-B was used together with the above calcium carbonate-A as a calcium carbonate raw material.
-Calcium carbonate-B: Ryton A-5 surface treated by Bikita Powder Industry Co., Ltd., average particle size 3.60 μm (second calcium carbonate) measured by the air permeation method according to JIS M-8511.
Waste plastic No. 100 parts by mass of each of 7 and 8, 96 parts by mass of calcium carbonate-A, and 4 parts by mass of calcium carbonate-B are 200 by using a small twin-screw kneading extruder (φ25 mm, L / D = 41) rotating in the same direction. Pellets were prepared by kneading at ° C, extruding into water with strands (preparation step), cooling, and cutting. 300 parts by mass of the obtained pellets and 100 parts by mass of the plant-derived resin-A are extruded with the same extruder under the same conditions (mixing step, plant-derived resin: first calcium carbonate: second calcium carbonate. : Mass ratio of waste resin component = 25: 24: 1: 50), cooled and cut to prepare pellets.

Using the obtained pellets, a film was prepared by an inflation film extrusion line (60 mm circular die, 1.2 mm die gap, 30 mm screw diameter, L / D ratio = 30). The film was treated with a BUR (blow-up ratio) of 3.0 to keep the frostline height at a height of 16 cm (distance from the die). In the extruder, the temperature of each area was set to 190 ° C. to 230 ° C. The rotation speed of the extruder was always maintained at 60 rpm, and the basis weight of the film was set to ^{35 g / m 2 by appropriate adjustment of the line speed.} Also, the cooling air flow was adjusted accordingly to keep the frost line in the same position. The produced inflation film had an extremely good appearance with no discoloration or variation in wall thickness. A dumbbell-shaped No. 3 test piece of JIS K6251: 2017 was punched out from this inflation film, and a tensile test was performed at a stretching speed of 200 mm / min using a strograph manufactured by Toyo Seiki Seisakusho Co., Ltd. The results are shown in Table 3 below, along with the state of the inflation film and the characteristics at the time of manufacture.

[Example 3]
Waste plastic No. 1 to 8 were selected (resin sorting step). Pellets were prepared by extruding (preparing), cooling, and cutting 100 parts by mass of each of these eight types under the same conditions as in the preparation step of Example 2. 800 parts by mass of the obtained pellets, 40 parts by mass of calcium carbonate-A and 280 parts by mass of plant-derived resin-A were extruded by the same extruder under the same conditions (mixing step, plant-derived resin: calcium carbonate). : Mass ratio of waste resin component = 25:25:50), cooled and cut to prepare pellets. When an inflation film was produced using the obtained pellets in the same manner as in Example 2, a film having a smooth appearance and no discoloration or thickness variation was obtained. The results of the tensile test performed in the same manner as in Example 2 are shown in Table 3 described later, together with the state of the inflation film and the characteristics at the time of manufacture.

[Example 4]
Waste plastic No. 1 to 10 were selected (resin sorting step). 100 parts by mass of each of these 10 types was extruded (preparation step), cooled, and cut under the same conditions as in the preparation step of Example 2 to prepare pellets. 1000 parts by mass of the obtained pellets and 400 parts by mass of the plant-derived resin-A are extruded with the same extruder under the same conditions (mixing step, plant-derived resin: calcium carbonate: mass ratio of waste resin component = about. 29:27:44), cooled and cut to prepare pellets. When an inflation film was produced using the obtained pellets in the same manner as in Example 2, a film having a smooth appearance and no discoloration or thickness variation was obtained. The results of the tensile test performed in the same manner as in Example 2 are shown in Table 3 described later, together with the state of the inflation film and the characteristics at the time of manufacture.

[Comparative Example 4]
Waste plastic No. 1 to 10 were selected (resin sorting step). 100 parts by mass of each of these 10 types and 400 parts by mass of the plant-derived resin-A are extruded under the same conditions as the mixing step of Example 2 (corresponding to the mixing step without the preparation step, plant-derived resin: calcium carbonate: Mass ratio of waste resin component = about 29:27:44), cooled and cut to prepare pellets. When an inflation film was produced using the obtained pellets in the same manner as in Examples 2 and 4, a film having poor smoothness with uneven wall thickness and uneven distribution of calcium carbonate was produced. The results of the tensile test performed in the same manner as in Example 2 are shown in Table 3 described later, together with the state of the inflation film and the characteristics at the time of manufacture.

[Comparative Example 5]
No resin sorting was performed, and the waste plastic No. Pellets were prepared by extruding 1 to 12 using 100 parts by mass under the same conditions as in the preparation step of Example 2. 1200 parts by mass of the obtained pellets and 400 parts by mass of the plant-derived resin-A were extruded under the same conditions as in the mixing step of Example 2 (plant-derived resin: calcium carbonate: mass ratio of waste resin component = 25: 25:50), cooled and cut to prepare pellets. When an inflation film was produced using the obtained pellets in the same manner as in Examples 2 and 4, a film having a thickness variation and inferior smoothness was produced. The results of the tensile test performed in the same manner as in Example 2 are shown in Table 3 together with the state of the inflation film and the characteristics at the time of manufacture.

As is clear from Table 3, the molded products produced through the resin sorting step, the preparation step, and the mixing step according to the present invention all had a good appearance, no wall thickness variation, and excellent tensile properties. .. In particular, the molded product of Example 2 in which the first calcium carbonate having an average particle diameter of 1.00 μm and the second calcium carbonate having an average particle diameter of 3.60 μm were used in combination had extremely good appearance such as smoothness. .. On the other hand, the inflation film of Comparative Example 4 produced without going through the preparation step was a molded product having the same composition as that of Example 4 but having a poor appearance and varying wall thickness, and had low tensile properties. The same was true for the inflation film of Comparative Example 5 produced without sorting the waste plastic. In the molded product of Comparative Example 5, the mass ratio of the waste resin component: calcium carbonate: the plant-derived polyolefin resin is the same as that of the molded products of Examples 2 and 3, but since they contain polyvinyl acetate having different polarities, they are uniform. It is probable that the mixture could not be mixed, resulting in uneven thickness and poor appearance.

Although it was not possible to compare the variation in physical properties in the above examples, it is known in the polymer processing industry that mixing of recycled products in a factory may suppress the variation in physical properties between lots. It is presumed that the same effect can be achieved by the manufacturing method. From the examples of this one lot, the processability and physical properties are not necessarily improved by simply mixing the recycled products, and in order to improve them, the resin sorting process and the preparation process according to the present invention are important. Was shown.

Claims (12)

A method for producing a polyolefin-based resin molded product containing an inorganic substance powder containing a plant-derived polyolefin resin and an inorganic substance powder.
A resin sorting process for sorting one or more waste plastic raw materials from waste plastic,
An inorganic substance comprising a preparation step of preparing a waste plastic preparation raw material from the selected one or a plurality of waste plastic raw materials, and a mixing step of mixing the plant-derived polyolefin resin and the waste plastic preparation raw material. A method for producing a powder-containing polyolefin resin molded product. The inorganic substance powder-containing polyolefin resin molded product contains the plant-derived polyolefin resin, the inorganic substance powder, and resin components derived from the waste plastic raw material in an amount of 20 to 30% by mass, 10 to 40% by mass, and 40 to 40, respectively. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to claim 1, which contains 60% by mass. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to claim 1 or 2, wherein the inorganic substance powder is mixed in the preparation step and / or the mixing step. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of claims 1 to 3, wherein the plant-derived polyolefin resin is a plant-derived polypropylene resin and / or a plant-derived polyethylene resin. The inorganic substance powder-containing polyolefin resin molded product according to any one of claims 1 to 4, wherein the plant-derived polyolefin resin is a plant-derived polypropylene resin having a biomass plasticity of 95% or more and / or a plant-derived polyethylene resin. Manufacturing method. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of claims 1 to 5, wherein the inorganic substance powder contains calcium carbonate. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to claim 6, wherein the calcium carbonate is heavy calcium carbonate. The first calcium carbonate having an average particle diameter of 0.5 μm or more and less than 2.0 μm measured by the air permeation method according to JIS M-8511 and the average particles measured by the air permeation method according to JIS M-8511. Contains a second calcium carbonate having a diameter of 2.0 μm or more and less than 9.0 μm.
The mass ratio of the first calcium carbonate to the second calcium carbonate is 90: 10 to 98: 2.
The plant-derived polyolefin resin contains a polyethylene resin and contains
The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to claim 6 or 7, wherein both the first calcium carbonate and the second calcium carbonate are surface-treated heavy calcium carbonate. The resin sorting step is performed by one or more analytical methods selected from mid-infrared spectroscopy, near-infrared spectroscopy, infrared spectroscopy, Raman spectroscopy, fluorescent X-ray analysis, X-ray diffraction, and TG / DTA. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of claims 1 to 8, which comprises a step of selecting a resin type. The method for producing a polyolefin-based resin molded product containing an inorganic substance powder according to any one of claims 1 to 9, wherein the preparation step and the mixing step include a kneading step by a twin-screw kneading extruder. The method for producing an inorganic substance powder-containing polyolefin-based resin molded article according to any one of claims 1 to 10, wherein the inorganic substance powder-containing polyolefin-based resin molded article is a resin pellet. An inorganic substance powder-containing polyolefin-based resin molded article obtained by the method for producing an inorganic substance powder-containing polyolefin-based resin molded article according to any one of claims 1 to 11.