JP2020050855A - Biodegradable resin composition, master batch, and molded body thereof - Google Patents

Abstract

To provide a resin composition solving followings: (1) enhancement of crystallization rate, (2) suppression of manufacturing cost, (3) fertilization of soil decomposition product, (4) capability of biodegradation in both of soil and sea water, (5) prevention of breakage during use, and (6) enhancement of sheet moldability all at once.SOLUTION: The biodegradable resin composition contains (A) a biodegradable resin and (B) a natural polysaccharide filler. At least one kind of the (A) biodegradable resin is a resin capable of degrading both of soil microorganism and marine microorganism, and contains polybutylene succinate and/or polybutylene succinate adibate of 30% or more based on total mass of the (A) biodegradable resin. The (B) natural polysaccharide filler contains starch or grain powder with average particle diameter of 80 μm or less or polysaccharide fiber with average particle length of 80 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a biodegradable resin composition, a master batch, and a molded product thereof.

  In recent years, from the viewpoint of environmental protection and the formation of a recycling-based society, it has been proposed worldwide to reuse organic resources (biomass materials) such as wood and grass. By utilizing biomass materials, new industrial promotion and economic growth can be realized while overcoming the environmental problems caused by heavy use of fossil fuels. This is called the "bio economy," and countries around the world are promoting promotion measures. In addition, "SDGs" adopted by the United Nations in 2015 as a global goal with the aim of ensuring the sustainability of the environment has become a social theme.

  For example, when farmers grow crops, they cover the ridges of the fields with agricultural and horticultural multi-sheets. By covering the multi-sheet for agriculture and horticulture, it is possible to prevent weeds from increasing in the field and to prevent fertilizer and soil from being cut by rain. It also has a moisturizing effect to prevent evaporation of water from the soil and a disease preventing effect.

  However, the multi-sheet for agriculture and horticulture is often mainly made of a hardly decomposable plastic film, and it is necessary to remove the multi-sheet for agriculture and horticulture after harvesting the crop. That said, removing the agricultural and horticultural multi-seat requires a great deal of effort, so replacing the material of the agricultural and horticultural multi-sheet with plastic that soil microorganisms can decompose, and after harvesting the crops, the farmer It is desirable to be able to stake the multi-sheet for use in soil. Preferably, after the biodegradation of the plastic, it is desirable that the decomposed product can function as a fertilizer.

  For example, some facial cleansers, toothpastes, creams, and the like contain a scrub agent for the purpose of exfoliating and cleaning. As the scrub agent, fine hard-to-decompose plastic particles called microbeads are sometimes used. As the microbeads flow into the drain, they pass through the sewage treatment plant and eventually flow into the ocean, where they accumulate in the ocean as hard-to-degrade microplastics.

  The same applies to relatively large non-degradable plastic waste such as straws, food and beverage packaging containers, tableware, and bags, as well as microbeads. When these plastic wastes flow into the ocean, they are crushed little by little by waves and sunlight, and eventually become hard-to-degrade microplastics.

  Microplastics have a property of adsorbing harmful substances such as polychlorinated biphenyl (PCB) and dichlorodiphenyltrichloroethane (DDT). When marine animals, such as zooplankton, small fish, and shellfish, prey on microplastics that have adsorbed harmful substances, the concentration of harmful substances in the food chain proceeds and goes around the human table.

  In addition, marine animals such as turtles and whales may erroneously prey on the plastic bags that have flowed into the ocean, resulting in death of the marine animals.

  From the above, it is urgently necessary to replace hard-to-degrade plastics with plastics that can be degraded by marine microorganisms.

  In addition, straws, food and beverage packaging containers, tableware, bags, fishing gear, fishing gear, floats, artificial seaweed bed structural members, and the like are known as main factors of plastic marine pollution. However, these are all products that are supplied at relatively inexpensive price ranges. Although a poly-3-hydroxyalkanoate resin is known as a resin that can be decomposed by both soil microorganisms and marine microorganisms, the price of the resin is two to three times that of general plastics. Although it is known to contribute to environmental protection, it has not been widely used.

  As a biodegradable resin composition, a biodegradable resin is blended with a biodegradable filler, the biodegradable resin is a polycarbonate resin, and the biodegradable filler is a plant-derived filler, (Patent Document 1). In this composition, the polycarbonate resin is a ring-opening addition polymer of ethylene oxide and / or propylene oxide with carbon dioxide; a ring-opening polymer of ethylene carbonate and / or propylene carbonate; dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate Propylene carbonate, diallyl carbonate, allyl methyl carbonate, bis (2-methoxyphenyl) carbonate, vinylene carbonate, dibenzyl carbonate, di (o-methoxyphenyl) carbonate and at least one carbonate selected from the group consisting of methyl ethyl carbonate At least one selected from the group consisting of condensation polymers of compounds with ethylene glycol and / or propylene glycol And it is preferable that one. In addition, plant-derived fillers include starch, plasticized starch, cellulose fiber powder, pulp, sugar, polysaccharide, vegetable protein, rosin, plant fiber, plant powder, wood flour, waste paper, tea extraction husk, coffee extraction husk, cereals It is preferably at least one powder selected from the group consisting of husk, citrus peel, sugar cane meal, straw, bamboo, legume peel, plant leaf and stem. The average particle size of the plant filler is preferably in the range of 1 to 500 μm. In addition, starch is a particularly preferred filler because it is safe and is quickly decomposed by microorganisms. However, it cannot be said that the polycarbonate resin described in Patent Document 1 is necessarily excellent in decomposability into seawater, and to provide a biodegradable resin composition excellent in both decomposability into seawater and cost. Have even more challenges. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Further, as a biodegradable resin composition, a dicarboxylic acid characterized by having a sulfur atom content in the dicarboxylic acid of 0.01 ppm or more and 100 ppm or less with respect to the dicarboxylic acid is used as a polyester raw material. Has also been proposed (Patent Document 2). It has also been proposed to use raw starch, processed starch, pulp, chitin / chitosan, coconut shell powder, wood powder, bamboo powder, bark powder, powder such as kenaf or straw as an organic filler. However, the polyester resin composition described in Patent Document 2 is not necessarily excellent in decomposability into seawater, and provides a biodegradable resin composition excellent in both decomposability into seawater and cost. Has even more challenges. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

In addition, as the biodegradable resin composition, in the aliphatic polyester resin, the recoverable strain γR (= N1 / 2σ) at a temperature of 190 ° C. and a shear rate of 5.0 sec ⁻¹ is 1.0 to 10.0, Further, an aliphatic polyester resin for producing a foam having a longest relaxation time τd at the same temperature of 10 seconds to 100 seconds has been proposed (Patent Document 3). The filler includes an inorganic filler and an organic filler. Examples of the inorganic filler include diatomaceous earth, calcined perlite, zeolite, kaolin, bentonite, silica, clay, glass, limestone, calcium silicate, calcium sulfate, aluminum oxide, and magnesium carbonate. And ferric carbonate. Organic fillers include organic fillers such as wood flour, starch, cellulose, and cellulose derivatives, and it is disclosed that these may be used in combination. However, to provide a biodegradable resin composition excellent in both degradability to seawater and cost, there are still more problems. In addition, the biodegradable resin composition containing the filler may be brittle, easily split by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Also, a degradable resin composition has been proposed in which 0.5 to 2 parts by weight of ultrafine titanium oxide is added to 100 parts by weight of a mixture of a biodegradable aliphatic polyester and a starch of natural or vegetable origin (Patent) Reference 4). Patent Document 4 discloses that a sheet and a film are formed from the composition and used as a packaging material or as a compost bag. First, it is disclosed that photodegradation is caused by the light of the sun and the substance is broken down, and when it becomes smaller, the substance comes into contact with living organisms or microorganisms in the soil or the sea and the decomposition is started. However, to provide a biodegradable resin composition excellent in both degradability to seawater and cost, there are still more problems. In addition, the biodegradable resin composition containing the filler may be brittle, easily split by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Also, a biodegradable thin film, woven fabric, nonwoven fabric, or laminated material manufactured from a composition containing PHA (polyhydroxyalkanoate) s and PLA (polylactic acid), and having a PLA weight percent content of 1% to 95%. A food packaging container has been proposed (Patent Document 5). Patent Literature 5 discloses that microbial polyester biodegradable in soil, sludge, or seawater is used as PHAs, and that a filler such as starch is added to the composition. However, the biodegradable resin composition containing the filler may be brittle, easily split by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  In addition, a biodegradable material containing PHAs and PLA and having a PLA mass percentage content of 1% to 95% has been proposed (Patent Document 6). Patent Document 6 discloses that, as the material, it is preferable to contain cellulose fiber, and it is preferable to use a microbial polyester biodegradable in soil, sludge or seawater as PHAs, and it is also preferable to manufacture a food packaging container. It has been disclosed. However, to provide a biodegradable resin composition excellent in both degradability to seawater and cost, there are still more problems. In addition, the biodegradable resin composition containing the filler may be brittle, easily split by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Also, a plurality of biodegradable abrasive particles from 0.1% to 15%, preferably from 0.3% to 10%, by weight of the composition, wherein the particles are safe and effective in weight. A plurality of biodegradable abrasive particles comprising a polyhydroxyalkanoate (PHA) biodegradable polymer material and having a particle size in the range of 10 μm to 1500 μ, and a multimodal particle size distribution of the biodegradable abrasive particles A skin cleansing composition comprising a multimodal particle size distribution, preferably comprising Distribution A and Distribution B, and a dermatologically acceptable carrier has been proposed (Patent Document 7). In this composition, the PHA comprises poly-3-hydroxybutyrate (PHB), poly-3-hydroxyhexanoate, poly-3-hydroxy-valerate, poly-3-hydroxy-butyrate-co-3-hydroxyvalerate. Rate (PHBV), poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH), and blends thereof. The particles also contain a plant-based filler, which is derived from vegetable sources and is essentially a cellulose or lignocellulosic material (eg, starch and flour, xanthan gum, alginic acid, dextran, agar, etc.). Nuts, tree or bamboo fibers, corn cobs, rice hulls, etc., containing such hydrocarbons. However, a biodegradable resin composition containing a plant-based filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Further, an aliphatic polyester resin composition containing a polyhydroxyalkanoate (A), pentaerythritol (B) and a filler (C) has been proposed (Patent Document 8). In this composition, the polyhydroxyalkanoate (A) comprises poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate), poly (3-hydroxybutyrate-co- 3-hydroxyvalerate-co-3-hydroxyhexanoate), poly (3-hydroxybutyrate-co-3-hydroxyhexanoate), and poly (3-hydroxybutyrate-co-4-hydroxybutyrate). Rate) and polylactic acid. The filler (C) is (a) wood-based materials such as wood chips, wood flour, sawdust, rice hulls, rice flour (equivalent to cereal powder), starch, corn starch, rice straw, wheat straw, natural rubber, etc. And (b) natural fibers made of organic substances, and examples of natural fibers include kenaf fiber, abaca fiber, bamboo fiber, jute fiber, hemp fiber, linen fiber, Henneken (sisal hemp), ramie fiber, Hemp, cotton, banana fiber, coconut fiber, coconut, palm, mulberry, mitsumata, bagasse, and the like.In addition, pulp and cellulose fiber processed from plant fiber, and regenerated fiber such as rayon, and the like. Among them, it is particularly preferable to use natural fibers for the purpose of having a high biomass degree in the composite with polyhydroxyalkanoate and for the purpose of not impairing environmental performance. The composition and pellets obtained from the composition can be molded by a known molding method, and any molded article can be obtained. Examples of the molding method include film molding, sheet molding, and injection molding. Molding, blow molding, fiber spinning, extrusion foaming, bead foaming, etc., the composition is excellent in processability and can be processed in a short time, for example, tableware, agricultural materials, OA parts It is disclosed that it can be suitably used as a base material for home electric parts, automobile parts, daily necessities, stationery, various bottle molded products, extruded sheets and profile extruded products. However, a biodegradable resin composition containing a plant-based filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

Further, a composition containing a biodegradable polyester resin and an organic filler has been proposed (Patent Document 9). As biodegradable polyester resins, besides poly (D-lactic acid) and poly (L-lactic acid); poly (ethylene succinate), poly (butylene succinate), poly (butylene succinate-co-butylene adipate) and the like Aliphatic polyesters comprising a representative diol and dicarboxylic acid; polyhydroxycarboxylic acids such as polyglycolic acid, poly (3-hydroxybutyric acid), poly (3-hydroxyvaleric acid) and poly (3-hydroxycaproic acid); poly Poly (ω-hydroxyalkanoate) represented by (ε-caprolactone) and poly (δ-valerolactone) can be used. In addition, as the organic filler, naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir husk, bran, kenaf and modified products thereof are used, injection molding, blow molding, extrusion molding, fiber Various moldings can be formed by known molding methods such as molding, and tableware, straws, food containers, agricultural and horticultural containers such as pots for raising seedlings, fibers for industrial materials, short fiber nonwoven fabric, and the like can be produced. Is disclosed. However, the resin described in Patent Document 9 is not necessarily excellent in degradability to seawater, and to provide a biodegradable resin composition excellent in both degradability to seawater and cost, It has even more challenges. In addition, the biodegradable resin composition containing a plant-based filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Further, a composition containing an aliphatic polyester and a natural filler obtainable by bacterial fermentation has been proposed (Patent Document 10). Patent Document 10 discloses that natural fibers include cellulose fibers and powders, rice hull fibers, straw fibers, corn fibers, wood fibers, bamboo fibers, and the like. From the composition, food or beverage cups, lids, cutlery, etc. To manufacture food service articles, molded trays and food storage containers. However, the resin described in Patent Document 10 is not necessarily excellent in decomposability into seawater, and in order to provide a biodegradable resin composition excellent in both decomposability into seawater and cost, It has even more challenges. In addition, the biodegradable resin composition containing a natural filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Further, a spacer pipe has been proposed which is a pipe mainly composed of a biodegradable resin and which is used for maintaining a seeding material for a culturing creature at a predetermined interval on a support suspended from a cultivation raft (Patent) Reference 11). The resin or the pipe is biodegraded by microorganisms in the ocean, and an organic filler such as wood flour or pulp can be added to the resin. However, the biodegradable resin composition containing the organic filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Also, biodegradable polymers such as semi-synthetic polyesters produced by fermentation such as PHB and PHBV, seagel, cork, seed, gelatin, wood flour, sawdust, pulverized polymer material, agar-based material, natural starch granules, There has been proposed a biodegradable sheet containing an organic filler such as gelatinized and dried starch, a cellulosic fiber, a beverage liquid food packaging container manufactured from the sheet, and a straw (Patent Document 12). However, the biodegradable resin composition containing the filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  In addition, a composition containing a bioplastic and a filler and a molded product thereof have been proposed (Patent Document 13). Patent Literature 13 uses, as bioplastics, polyhydroxybutyrate, polyhydroxyvalerate, and polyhydroxybutyrate-hydroxyvalerate copolymer, and uses a plant-derived filler, a cellulose fiber, wood flour, and starch as a filler. Is disclosed. In addition, injection molding, extrusion molding, rotational molding, foam molding, calender molding, blow molding, thermoforming, compression, melt spinning, etc., molding of marine equipment (equivalent to fishing gear) such as exterior of sounding equipment, etc. Is disclosed. However, the biodegradable resin composition containing the filler is brittle, and may be easily torn by hand or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Further, Patent Document 13 discloses that various molding methods can be used, but the biodegradable resin composition containing a filler may be easily torn or cracked when the resin molded body is folded. For this reason, it cannot always be said that molding can be performed by various molding methods.

  Further, a multilayer film formed using a composition containing a biodegradable polymer and a plant-based organic fine particle filler and a flexible package for food packaging formed using the multilayer film have been proposed (Patent Document 14). . The use of polylactic acid (PLA) polymer, polyhydroxyalkanoate (PHA), and polybutylene succinate (PBS) as the biodegradable polymer, and the indication that the plant-based organic fine particle filler is a filler derived from renewable biomass It is disclosed that oat hulls, soy flakes, rice hulls, and coconut shells are used as the filler. However, it cannot be said that the resin composition described in Patent Literature 14 is always excellent in decomposability into seawater, and to provide a biodegradable resin composition excellent in both decomposability into seawater and cost. Has even more challenges. In addition, the biodegradable resin composition containing the filler may be brittle, easily torn by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Further, a composition in which rosin is added in an amount of 0.3 to 10 parts by weight when a large amount of an organic filler is added to 100 parts by weight of a biodegradable resin component, and a sheet (molded article) produced from the molded article have been proposed. (Patent Document 15). Patent Literature 15 describes that, as a biodegradable resin, polylactic acid or a biopolyester (polyhydroxyalkanoate) produced by decomposing a natural product by a microorganism is used, and an organic filler is used to dry and grind trees, bark, and hay. It is disclosed that plant flour, cereal, cereal flour obtained by crushing these rice husks, and crushed waste paper are used. However, it cannot be said that the resin composition described in Patent Literature 15 is always excellent in degradability to seawater, and to provide a biodegradable resin composition excellent in both degradability to seawater and cost. Has even more challenges. In addition, the biodegradable resin composition containing the filler may be brittle, easily torn by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  100 parts by weight of a polylactic acid-based mixture containing 80 to 100% by weight of a polylactic acid or a lactic acid-hydroxycarboxylic acid copolymer and 0 to 20% by weight of a plasticizer, and finely powdered filler having an average particle size of 0.1 to 7 μm. A bag for fruit cultivation has been proposed in which a resin composition containing 40 to 250 parts by weight of an agent is melt-formed and then formed into a porous film obtained by stretching at least 1.1 times or more in one axis direction. (See Patent Document 16). Patent Document 16 discloses that organic fine powder such as cellulosic powder such as wood powder and pulp powder is used as the fine powder filler. However, it cannot be said that the resin composition described in Patent Literature 16 is always excellent in decomposability into seawater, and to provide a biodegradable resin composition excellent in both decomposability into seawater and cost. Has even more challenges. In addition, the biodegradable resin composition containing the filler may be brittle, easily torn by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

  Also, a biodegradable polyester such as a poly (3-hydroxybutyric acid-3-hydroxyhexanoic acid) copolymer, a film or sheet containing a (modified) starch having a particle size of 2-3 μm as a filler is used as a packaging material, It has been proposed to use it as an agricultural material such as a growing house or a multi-film (Patent Document 17). However, the biodegradable polyester described in Patent Document 17 is not necessarily excellent in seawater decomposability, and provides a biodegradable resin composition excellent in both seawater decomposability and cost. Has even more challenges. In addition, the biodegradable resin composition containing the filler may be brittle, easily torn by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater. Furthermore, in order to be usable in a wide variety of applications as described above, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding, but the physical properties of the resin composition can be coped with any molding. There are even more challenges to achieving.

JP 2007-217611 A JP 2009-79057 A JP 2003-268143 A JP-A-9-194492 JP 2006-513153 A JP 2006-511785 A JP-T-2018-522059 WO 2015/052876 International Publication No. 2009/110171 US Patent Application Publication No. 2009/0274020 JP 2005-110518 A JP-T-2015-507653 US Patent Application Publication No. 2015/0045490 US Patent Application Publication No. 2016/0333356 International Publication No. 2005/059036 JP-A-6-90628 International Publication No. WO 2006/075553

  Here, the biodegradable resin is relatively expensive, and it is difficult to apply the biodegradable resin to relatively inexpensive plastic products such as multi-sheets for agricultural and horticultural use and straws at the current price. In addition, after the resin composition is decomposed into soil, it is desirable that the decomposed product can function as a soil fertilizer.

  In addition, the biodegradable resin composition containing the filler may be brittle, easily torn by hand, or cracked when the resin molded body is folded. Therefore, there is a need to provide a resin composition that does not split or break during use, but can be easily decomposed in soil or seawater.

  In addition, multi-sheets for agricultural and horticultural use, plastic pots for agricultural and horticultural use, nets for agricultural and horticultural use, masking films, straws, cutlery, food and beverage packaging containers, tableware, plastic bags, micro beads, micro fibers, drainage nets, fishing gear, fishing gear, floats In order to be able to be used in a wide variety of applications such as one or more applications selected from artificial seaweed bed structural members, it is necessary to be able to cope with various conventionally known moldings such as injection molding and sheet molding. However, in order to make the physical properties of the resin composition compatible with any molding, there are still more problems.

  The present invention has been made in view of such problems, and (1) To improve the crystallization rate, which is a problem of the biodegradable resin composition, to lead to improvement in tensile elongation and tear strength; 2) To reduce the production cost of the biodegradable resin composition, and to make it applicable to relatively inexpensive plastic products such as multi-sheets and packaging containers for agricultural and horticultural use. (4) To provide a biodegradable resin composition capable of decomposing both soil microorganisms and marine microorganisms, solve problems of marine pollution and soil pollution, and contribute to bioeconomics and SDGs. (5) To provide a resin composition which does not split or break during use, but which can be easily decomposed in soil or seawater; and (6) Injection molding, sheet molding, etc. And to provide a biodegradable resin composition which has solved at once allowing corresponding to various forming of knowledge.

  The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, (A) at least one kind of biodegradable resin capable of decomposing both soil microorganisms and marine microorganisms has biodegradability. When mixing the (B) natural polysaccharide filler with (A) the biodegradable resin and (B) the natural polysaccharide filler, both of which are specific materials, the above (1) to (6) can be performed at once. And found that the present invention was completed. Specifically, the present invention provides the following.

  The invention according to the first aspect includes (A) a biodegradable resin, and (B) a natural polysaccharide filler, wherein at least one of the (A) biodegradable resins is any one of a soil microorganism and a marine microorganism. Is a decomposable resin, containing 30% or more of polybutylene succinate and / or polybutylene succinate adipate based on the total mass of the (A) biodegradable resin, and the (B) natural polysaccharide filler Is a biodegradable resin composition containing starch flour or cereal flour having an average particle size of 80 μm or less, or polysaccharide fibers having an average particle length of 80 μm or less.

  Regarding the first problem, since (B) a natural polysaccharide filler is dispersed in (A) a biodegradable resin, the crystallization speed is increased by the filler dispersion effect, and crystallization proceeds. Thereby, the first problem "(1) Improvement of crystallization rate, which is a problem of the biodegradable resin composition, leading to improvement of tensile elongation and tear strength" can be solved.

  Regarding the second problem, since (B) the natural polysaccharide filler can be obtained at a lower cost than polycaprolactone resin or the like, the second problem, “(2) the production cost of the biodegradable resin composition, is reduced. And make it applicable to relatively inexpensive plastic products such as agricultural and horticultural multi-sheets. "

  Regarding the third problem, when the resin composition is decomposed by soil microorganisms, the soil contains a natural polysaccharide that can function as a fertilizer component. Making soil degradation products available as fertilizer ".

  Regarding the fourth problem, (A) the biodegradable resin is a resin capable of decomposing both soil microorganisms and marine microorganisms, and (B) the natural polysaccharide filler is also capable of decomposing both soil microorganisms and marine microorganisms. Therefore, the fourth problem of solving the problems of marine pollution and soil pollution and contributing to the bio-economy and SDGs can also be solved.

  Regarding the fifth problem, since (A) as a biodegradable resin contains polybutylene succinate and / or polybutylene succinate adipate in an amount of 30% or more based on the total mass of the (A) biodegradable resin, The fifth problem of "providing a resin composition which does not crack or break when used, but which can be easily decomposed in soil or seawater" can be solved.

  Regarding the sixth problem, the resin composition can be provided as a masterbatch, and is provided as a masterbatch, and by appropriately adjusting the ratio of the base resin, the sixth problem, “injection molding, sheeting” It is possible to cope with various conventionally known moldings such as molding, film molding, blow molding, etc. ".

  Therefore, according to the present invention, the above (1) to (6) can be solved at once.

  The invention according to the second aspect is the biodegradable resin composition according to the first aspect, wherein the (A) biodegradable resin comprises the polybutylene succinate adipate and the poly-3-hydroxybutyrate. -Co-3-hydroxyhexanoate, a resin decomposable by both soil microorganisms and marine microorganisms, and the content of the polybutylene succinate adipate is the same as that of the (A) biodegradable resin. 30% or more with respect to the total mass, and the content of the poly-3-hydroxybutyrate-co-3-hydroxyhexanoate is 70% or less with respect to the total mass of the (A) biodegradable resin. is there.

  Currently, biodegradable resins that can be biodegraded in soil and ocean are very limited, and poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH) is famous. Butylene succinate adipate (PBSA) has been identified. (Literature: Atsushi Nakayama et al., "Plastics" 11.1-5 (2018), etc.).

  According to the invention according to the second aspect, it includes polybutylene succinate adipate and poly-3-hydroxybutyrate-co-3-hydroxyhexanoate. The former is a resin with a small elastic modulus and is flexible and has a large elongation.On the other hand, the latter is a resin with a property of being hard but having a large elasticity but no elongation. Depending on the application, a biodegradable resin composition suitable for both flexibility and hardness can be provided. In addition, since the content of the former is 30% or more with respect to the total mass of the biodegradable resin (A) and the content of the latter is 70% or less, molding of the resin composition into a resin molded product is possible. It can be prevented from tearing or cracking at the time or when the resin molded body is used.

  The invention according to a third aspect is a master batch comprising the biodegradable resin composition of the invention according to the first or second aspect, wherein (B) the content of the natural polysaccharide filler is (A) biodegradable. It is 10 parts by mass or more and 250 parts by mass or less based on 100 parts by mass of the resin.

  According to the invention according to the third aspect, by supplying a resin composition in which the hardness and flexibility of the biodegradable resin is adjusted as a master batch, the ratio of the base resin can be further appropriately adjusted, and as a result, It is possible to flexibly cope with the sixth problem, that is, to make it possible to cope with various conventionally known molding methods such as injection molding and sheet molding.

  The invention according to a fourth aspect is the biodegradable resin composition according to the first or second aspect, wherein the multi-sheet for agriculture and horticulture, a plastic pot for agriculture and horticulture, a net for agriculture and horticulture, a straw, cutlery, food and drink A biodegradable resin composition used in one or more applications selected from product packaging containers, tableware, bags, microbeads, microfibers, drainage nets, fishing gear, fishing gear, floats, and artificial seaweed bed structural members. .

  The invention according to a fifth aspect is a biodegradable resin molded article obtained by molding the biodegradable resin composition according to the first or second aspect.

  According to the present invention, (1) the aim is to improve the crystallization rate, which is a problem of the biodegradable resin composition, and to improve the tensile elongation and tear strength, and (2) to reduce the production cost of the biodegradable resin composition. To make it applicable to relatively inexpensive plastic products such as multi-sheets and packaging containers for agriculture and horticulture, (3) to make soil decomposed products usable as fertilizer, (4) to make soil microorganisms Providing a biodegradable resin composition decomposable by both marine and marine microorganisms, solving the problems of marine pollution and soil pollution and contributing to bio-economy and SDGs, (5) tearing or cracking during use To provide a resin composition that can be easily decomposed in soil or seawater without any problems. (6) Various conventionally known methods such as injection molding, sheet molding, film molding, and blow molding. It is possible to provide a biodegradable resin composition which has solved at once allowing corresponding to the molding.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments at all, and may be implemented with appropriate changes within the scope of the present invention. can do.

<Biodegradable resin composition>
The biodegradable resin composition of the present embodiment contains (A) a specific biodegradable resin and (B) a specific natural polysaccharide filler.

[(A) Specific biodegradable resin]
(A) At least one type of biodegradable resin is a resin that can degrade both soil microorganisms and marine microorganisms.

  The (A) biodegradable resin is polybutylene succinate (also referred to as PBS) and / or polybutylene succinate adipate (also referred to as PBSA). Contains 30% or more based on the mass. Among them, the biodegradable resin (A) more preferably contains PBSA because of its high degradability by marine microorganisms.

  Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (also referred to as PHBH) is widely known as a resin capable of decomposing both soil microorganisms and marine microorganisms. Since a biodegradable resin composition excellent in both flexibility and hardness can be provided, (A) the biodegradable resin comprises polybutylene succinate adipate and poly-3-hydroxybutyrate-co-3-hydroxy. It is preferred to include both hexanoate. On the other hand, if the content of PHBH is too large, (B) when a specific natural polysaccharide filler is blended and molded from the resin composition into a resin molded product, the resin molded product may be torn or broken at the time of use. There is. Specifically, the resin composition becomes brittle, and can be used for molded articles such as injection molding, but is difficult to use for film molding, sheet molding, and the like, and is used for agricultural and horticultural multi-sheets, straws, bags, and the like. However, it cannot be said that a vacuum forming sheet, a decorative sheet, a decorative film, a curing sheet, and the like can be easily supplied. Therefore, in this case, the content of PBSA is at least 30%, preferably at least 50%, based on the total mass of the (A) biodegradable resin, and the content of PHBH is (A) the total mass of the biodegradable resin. Is preferably 70% or less, more preferably 50% or less.

  In addition, PLGA: poly (lactide-co-glycolide) and the like are also known as resins that can degrade both soil microorganisms and marine microorganisms. (A) The biodegradable resin may be a mixture of a plurality of resins, and the (A) biodegradable resin may contain PLGA or the like as long as the above ratio is satisfied.

[(B) Natural polysaccharide filler]
(A) It is known that a biodegradable resin is hard, crystallizes very slowly, and becomes brittle due to a change with time after molding. In the present embodiment, since the natural polysaccharide filler (B) is dispersed in the biodegradable resin (A), the crystallization speed is increased by the filler dispersing effect, and crystallization proceeds. As a result, it is possible to improve the crystallization rate, to improve tearing during film forming, sheet forming, and the like, and to improve tensile elongation and tear strength.

  In addition, biodegradable resins are more expensive than general plastics and are known to contribute to environmental protection, but they are applied to relatively inexpensive plastic products such as agricultural and horticultural multi-sheets. The hurdle is still high. In the present embodiment, by dispersing the (B) natural polysaccharide filler in the (A) biodegradable resin, it is possible to reduce costs and contribute to accelerating the replacement with a plastic material that contributes to bioeconomics and SDGs.

  Further, when the resin composition is decomposed by soil microorganisms, the soil contains natural polysaccharides that can function as fertilizer components. Therefore, not only the biodegradable resin composition is provided, but also after the resin composition decomposes in the soil, the decomposed product can function as a fertilizer for soil.

  (B) The natural polysaccharide filler contains starch powder or cereal powder having an average particle diameter of 100 μm or less, or polysaccharide fibers having an average particle length of 80 μm or less. If the average particle diameter or average particle length exceeds 80 μm, a sufficient filler dispersing effect cannot be obtained despite the fact that (B) the natural polysaccharide filler is dispersed in the (A) biodegradable resin, It is not preferable because it may not be possible to cope with film forming, sheet forming, and the like.

  (B) The average particle diameter or average particle length of the natural polysaccharide filler is 80 μm or less, and more preferably 50 μm or less.

  (B) Types of natural polysaccharide fillers include starch powders (corn starch, waxy corn starch, wheat starch, rice starch, bean starch, potato starch, sweet potato starch, tapioca starch, bracken starch, kuzu starch, etc.), and cereal powder (rice flour, rice flour, etc.). Flour and the like), pulverized pulp fibers and dietary fibers, and finely divided polysaccharide fibers of wood and bamboo.

  (B) When the natural polysaccharide filler is a fine powder, it is advantageous to use a masterbatch in order to avoid mixing accuracy, handling difficulties and danger of powder explosion. Mixing a melt crystalline resin is effective. In order to obtain higher biodegradability, in the case of (B) a natural polysaccharide filler such as starch powder and cereal powder, a method of forming granules by adding water or a polyhydric alcohol and shearing is also very effective.

  (B) The upper limit of the natural polysaccharide filler is not particularly limited as long as it is within a range that can achieve both an improvement in the crystallization rate and a reduction in cost. The upper limit of the content of the (B) natural polysaccharide filler is preferably 250 parts by mass or less based on 100 parts by mass of the (A) biodegradable resin. In consideration of stable production, the upper limit of the content of (B) the natural polysaccharide filler is more preferably 150 parts by mass or less based on 100 parts by mass of the biodegradable resin (A), and more preferably 100 parts by mass. It is more preferred that:

  (B) The lower limit of the natural polysaccharide filler is also not particularly limited, as long as the crystallization rate can be improved and the cost can be reduced. The lower limit of the content of the (B) natural polysaccharide filler is preferably 5 parts by mass or more based on 100 parts by mass of the (A) biodegradable resin. It is provided as a masterbatch, and by appropriately adjusting the proportion of the base resin, the molding method can be flexibly adapted to the physical properties of the molded body. (B) The lower limit of the content of the natural polysaccharide filler is (A) because the mixing accuracy when the saccharide filler is a fine powder, the ease of handling, and the avoidance of the risk of powder explosion are improved. It is more preferably at least 10 parts by mass, and even more preferably at least 20 parts by mass, per 100 parts by mass of the biodegradable resin.

(Other additives)
The biodegradable resin composition in the present embodiment may contain various additives as long as the effects described in the present embodiment are not impaired. As additives, for example, a lubricant, a crystallization nucleating agent, a plasticizer, a hydrolysis inhibitor, an antioxidant, a release agent, an ultraviolet absorber, a coloring agent such as a dye or a pigment, an inorganic filler, etc. Although they can be used, those additives preferably have biodegradability.

[Lubricant]
The type of the lubricant is not particularly limited. For example, fatty acid amides such as behenic acid amide, stearic acid amide, erucic acid amide, oleic acid amide, alkylene fatty acid amides such as methylenebisstearic acid amide, ethylenebisstearic acid amide, polyethylene wax, oxidized polyester wax, glycerin monostearate Glycerin monobehenate, glycerin monofatty acid ester such as glycerin monolaurate, organic acid monoglyceride such as succinic saturated fatty acid monoglyceride, sorbitan behenate, sorbitan stearate, sorbitan fatty acid ester such as sorbitan laurate, diglycerin stearate , Diglycerin laurate, tetraglycerin stearate, tetraglycerin laurate, decaglycerin stearate, decaglycerin laurate, etc. Li glycerol fatty esters, higher alcohol fatty acid esters such as stearyl stearate. These may be used alone or in combination of two or more.

[Crystal nucleating agent]
The type of the crystallization nucleating agent is not particularly limited as long as it can promote crystallization of the biodegradable resin (A). For example, boron nitride, titanium oxide, talc, layered silicate, calcium carbonate, sodium chloride, inorganic substances such as metal phosphates, erythritol, galactitol, mannitol, sugar alcohol compounds derived from natural products such as arabitol, pentaerythritol Dicarboxylic acids such as, polyvinyl alcohol, chitin, chitosan, polyethylene oxide, aliphatic carboxylic acid amide, aliphatic carboxylate, aliphatic alcohol, aliphatic carboxylic acid ester, dimethyl adipate, dibutyl adipate, diisodecyl adipate, dibutyl sebacate Derivatives, cyclic compounds having C ＝ O and a functional group selected from NH, S and O in the molecule, such as indigo, quinacridone and quinacridone magenta, bisbenzylidenesorbitol and bis (p-methylbenzyl) Den) sorbitol derivatives such as sorbitol, compounds containing a nitrogen-containing heteroaromatic nucleus such as pyridine, triazine, imidazole, phosphate compounds, bisamides of higher fatty acids and metal salts of higher fatty acids, branched polylactic acid, Molecular weight poly-3-hydroxybutyric acid and the like. These may be used alone or in combination of two or more.

[Plasticizer]
The type of the plasticizer is not particularly limited. For example, glycerin diacetmonolaurate, glycerin diacetmonocaprylate, modified glycerin compounds such as glycerin diacetmonodecanoate, diethylhexyl adipate, dioctyl adipate, adipate compounds such as diisononyl adipate, polyethylene glycol dibenzoate, polyethylene Examples thereof include polyetherester compounds such as glycol dicaprylate and polyethylene glycol diisostearate, benzoic ester compounds, epoxidized soybean oil, epoxidized fatty acid 2-ethylhexyl, and sebacic acid monoester. These may be used alone or in combination of two or more.

(Production method of biodegradable resin composition)
The method for producing the biodegradable resin composition is not particularly limited. However, in order to increase the degree of freedom of the content of (B) the natural polysaccharide filler, (A) first add (B) the natural polysaccharide filler to the biodegradable resin. It is preferable to produce a master pellet in which is dispersed at a high concentration, and then mix the biodegradable resin (A) with the master pellet to produce a resin pellet. This is because of the accuracy and difficulty in directly mixing (B) natural polysaccharide filler powder and (A) biodegradable resin pellets, and (B) fine powder of natural polysaccharide filler. This is not only to avoid the danger of explosion, but also to obtain a composition containing (B) a natural polysaccharide filler at a high concentration.

  A method described in Japanese Patent No. 6108782 can be used as a method for producing a master pellet.

<Biodegradable resin molded body>
The biodegradable resin molded article of the present embodiment is obtained by molding the above biodegradable resin composition.

  The use of the molded article is not particularly limited. For example, for agricultural and horticultural multi-sheets, agricultural and horticultural plastic pots, agricultural and horticultural nets, straws, cutlery, food and beverage packaging containers, tableware, plastic bags, vacuum molding One or more applications selected from sheets, curing sheets, microbeads, microfibers, drainage nets, fishing gear, fishing gear, floats, and artificial algae bed structural members.

  Among them, in the invention described in the present embodiment, a biodegradable resin capable of decomposing both soil microorganisms and marine microorganisms, and a resin composition containing a filler film forming, sheet forming, etc. It is also characterized by being able to respond to From that point of view, it is more preferable that the application is one or more applications selected from agricultural and horticultural multi-sheets, straws, plastic bags, vacuum forming sheets, and curing sheets.

  As an example, an application example to an agricultural / horticultural multi-sheet will be described. When farmers grow their crops, they cover the ridges of the fields with agricultural and horticultural multi-sheets. By covering the multi-sheet for agriculture and horticulture, it is possible to prevent weeds from increasing in the fields, keep the soil warm, and prevent fertilizers and soil from being cut by rain. It also has a moisturizing effect to prevent evaporation of water from the soil and a disease preventing effect.

  However, the multi-sheet for agriculture and horticulture is often mainly made of a hardly decomposable plastic film, and it is necessary to remove the multi-sheet for agriculture and horticulture after harvesting the crop. That said, removing the multi-sheet for agriculture and horticulture after a necessary limited period of time requires a great deal of effort, so replacing the material of the multi-sheet for agriculture and horticulture with plastic that soil microorganisms can decompose, and after harvesting the crop It is desirable to enable farmers to lay the agricultural / horticultural multi-sheet into soil. Preferably, after the biodegradation of the plastic, it is desirable that the decomposed product can function as a fertilizer.

  A biodegradable multi-sheet is also commercially available, but a sheet made of 100% resin is not sufficiently biodegradable and has a bad effect that fragments are scattered in the course of decomposition, but (B) the natural polysaccharide filler has a high concentration. If it is dispersed in water, high biodegradability and soil conversion will proceed quickly, and scattering problems will be reduced.

  Until now, several types of plastics that can decompose soil microorganisms have been proposed, but biodegradable resins are relatively expensive, and in the current price range, they are relatively inexpensive, including multi-sheets for agricultural and horticultural use. Difficult to apply to plastic products supplied by In addition, biodegradable resins are hard and are very slow to crystallize, so they are known to become brittle due to aging after molding, and have problems in improving tensile elongation and tear strength. .

  By applying the biodegradable resin composition described in the present embodiment to a multi-sheet for agricultural and horticultural use, (1) the crystallization rate, which is a problem of the biodegradable resin composition, is improved, and tensile elongation and tear strength are achieved. (2) lowering the production cost of the biodegradable resin composition and making it applicable to relatively inexpensively supplied plastic products such as agricultural and horticultural multi-sheets; (3) soil It is possible to make the use of the decomposed product available as fertilizer at once.

  As another example, application examples to straws, cutlery, food and beverage packaging containers, tableware, plastic bags, drainage nets, fishing gear, fishing gear, floating, and artificial seaweed bed structural members will be described.

  When these plastic products stay in the ocean, they are gradually crushed by waves and sunlight, and eventually become hard-to-degrade microplastics.

  Microplastics have a property of adsorbing harmful substances such as polychlorinated biphenyl (PCB) and dichlorodiphenyltrichloroethane (DDT). When marine animals, such as zooplankton, small fish, and shellfish, prey on microplastics that have adsorbed harmful substances, the concentration of harmful substances in the food chain proceeds and goes around the human table.

  In addition, marine animals such as turtles and whales may erroneously prey on the plastic bags that have flowed into the ocean, resulting in death of the marine animals.

  According to the invention described in the present embodiment, the above-described (1) to (1) to (1) to ( In addition to the problem (3), (4) a biodegradable resin composition capable of decomposing both soil microorganisms and marine microorganisms is provided, thereby solving the problems of marine pollution and soil pollution and contributing to bio-economy and SDGs. Can be solved at once.

  Further, regarding the above-mentioned second problem (cost aspect), all of these products are products supplied at a relatively low price range. Poly-3-hydroxyalkanoate resin is known as a resin that can be decomposed by both soil microorganisms and marine microorganisms, but the resin is about three times as expensive as general-purpose plastics, Although it is known to contribute to environmental protection, it has not spread widely. According to the invention according to the second feature, from the viewpoint of different from the mixing of other biodegradable resins as in the invention described in Patent Document 1, a method that achieves both improvement in crystallization and cost reduction is adopted. This can contribute to accelerating the replacement with plastic materials that contribute to the bio-economy.

  The above description has been made by taking a poly-3-hydroxyalkanoate resin as an example. PBS: polybutylene succinate, PBAT: polybutylene adipate terephthalate, PHBH: poly (3-hydroxybutyrate-co-3-) Hydroxyhexanoate), PGA: polyglycolic acid, and other biodegradable resins have the same first and second problems. Any of the present technology can be applied to solve these problems.

Hereinafter, the present invention will be described specifically with reference to Test Examples, but the present invention is not limited thereto.

<Test Example 1> Mixing of filler into PBS [Preparation of sample]
[Example 1-1]
69 parts by mass of polybutylene succinate (manufactured by Mitsubishi Chemical Corporation, BioPBS, FZ71PB) and 31 parts by mass of dietary fiber (manufactured by Healthy Company, insoluble dietary fiber, particle size 28 μm ≧) were mixed in a plastic bag. The mixture was extruded at a set temperature of 160 ° C. and a rotation number of 150 rpm with a shaft extrusion tester (Toyo Seiki Co., Ltd., Labo Plast Mill), and this was repeated twice to obtain a kneaded pellet.

[Example 1-2]
Kneaded pellets of Example 1-2 were obtained in the same manner, except that the dietary fiber of Example 1-1 was replaced with corn starch (commercially available, particle size: 6 to 25 μm).

[Example 1-3]
The kneaded pellets of Example 1-3 were similarly obtained by changing 31 parts by mass of the dietary fiber of Example 1-1 to 15.5 parts by mass of the dietary fiber and 15.5 parts by mass of the corn starch.

[Comparative Example 1-1]
The kneaded pellets of Comparative Example 1-1 were similarly obtained by replacing the dietary fiber of Example 1-1 with paper pulp fiber (fiber length 2 mm ≧).

[Comparative Example 1-2]
Kneaded pellets of Comparative Example 1-2 were similarly obtained by changing the dietary fiber of Example 1-1 to hinoki wood flour (particle size: 300 μm ≧).

[Evaluation]
[Tear feeling]
In order to measure the strength and toughness of the resin pellets when formed into a sheet or a film, a sheet was prepared with a hot press and a cooling press set at 160 ° C. using the pellets according to the examples and comparative examples. And then left at room temperature for one week or more to promote crystallization. A sheet strip (about 10 mm in width) was cut out from this sheet (about 0.25 ± 0.1 mm in thickness), and the center was gripped with both hands and pulled toward both ends. Table 1 shows the results. In Table 1, “◎” indicates that the material was not torn even when pulled strongly, “○” indicates that the material was torn when strongly pulled, but not torn otherwise, and “×” indicates that the material was easily torn. It also indicates that the sheet strip was broken when folded. This feeling of tearing is closer to the actual use evaluation than the mechanical measurement.

[Tensile test]
A 90-degree tear test piece and a tensile dumbbell-shaped test piece according to JIS K7161 were obtained from the sheet prepared above by die punching. Then, a tensile test according to JIS K7161 is performed using the above test piece, and the tear strength (unit: N / mm 2), the tensile strength (unit: N / mm ² ), and the tensile elongation (unit:%) are measured. did. Table 1 shows the results.

  (B) When the natural polysaccharide filler is starch powder or cereal powder having an average particle diameter of 80 μm or less, or when it is a dietary fiber having an average particle length of 80 μm or less, both the toughness and strength of the molded article are excellent. It was confirmed that the resin pellet can be used not only in the injection molding but also in the form of the film molding and the sheet molding (Example).

  On the other hand, when the average particle diameter or average particle length of (B) the natural polysaccharide filler exceeds 100 μm, sufficient (B) natural polysaccharide filler is dispersed in (A) biodegradable resin. It was confirmed that it was not possible to obtain a good filler dispersion effect, and it was difficult to cope with film forming, sheet forming, and the like (Comparative Example).

<Test Example 2> Mixing of filler into PBSA or PHBH Since the biodegradability in an anaerobic environment such as seawater was superior to that of PBS, the test was performed by replacing PBS with PBSA or PHBH.

(Preparation of sample)
[Example 2-1]
69 parts by mass of polybutylene succinate adipate (manufactured by Mitsubishi Chemical Corporation, BioPBS-A, FD92PB) and 31 parts by mass of dietary fiber (manufactured by Healthy Company, insoluble dietary fiber, particle size: 28 μm ≧) in a plastic bag. The mixture was extruded at a set temperature of 150 ° C. and a rotation number of 150 rpm with a twin screw extruder (Toyo Seiki Co., Ltd., Labo Plast Mill), and this was repeated twice to obtain a kneaded pellet.

[Example 2-2]
The kneaded pellets of Example 2-2 were obtained in the same manner, except that the dietary fiber of Example 2-1 was replaced with corn starch (commercially available, particle size: 6 to 25 μm).

[Example 2-3]
Kneaded pellets of Example 2-3 were obtained in the same manner, except that the dietary fiber (particle diameter: 28 μm ≧) of Example 2-1 was replaced with dietary fiber (particle diameter: 45 μm ≧).

[Comparative Example 2-1]
Kneaded pellets of Comparative Example 2-1 were obtained in the same manner, except that the polymer used in Example 2-1 was replaced with poly-3-hydroxybutyrate-co-3-hydroxyhexanoate.

[Comparative Example 2-2]
Kneaded pellets of Comparative Example 2-2 were obtained in the same manner, except that the dietary fiber of Comparative Example 2-1 was replaced with dietary fiber (particle size: 45 μm ≧).

[Comparative Example 2-3]
The kneaded pellets of Comparative Example 2-3 were similarly obtained by replacing the dietary fiber of Comparative Example 2-13 with paper pulp fiber (fiber length 2 mm ≧).

[Evaluation]
Hand tear feeling was compared by the same method as in Test Example 1, and a tensile test was performed. Table 2 shows the results.

  When the (A) biodegradable resin is PBSA and (B) the average particle diameter or average particle length of the natural polysaccharide filler is 80 μm or less, both the toughness and strength of the molded article are excellent, It was confirmed that the present invention can be used not only by injection molding but also by film molding and sheet molding (Examples). It is presumed that the reason is that the PBSA resin is soft and has a large elongation.

  On the other hand, when (A) the biodegradable resin is PHBH, the elongation is extremely small in spite of dispersing the (B) natural polysaccharide filler suitable for the (A) biodegradable resin. It was confirmed that it was difficult to cope with film forming, sheet forming, etc. (Comparative Example). It is presumed that the reason is that the tensile elongation of the PHBH resin itself is very small and the crystallization is slow.

<Test Example 3> Mixing of filler into mixed resin of PBSA and PHBH For the purpose of increasing the flexibility of adjustment of flexibility and hardness in accordance with the physical properties required for the molded article, PBSA or PHBH alone was used to mix PBSA and PHBH. The test was performed by replacing the resin with PHBH.

(Preparation of sample)
[Example 3-1]
34.5 parts by mass of polybutylene succinate adipate (manufactured by Mitsubishi Chemical Corporation, BioPBS-A, FD92PB) and poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (manufactured by Kaneka Corporation, PHBH) , X-331N) 34.5 parts by mass and 31 parts by mass of dietary fiber (manufactured by Healthy Company, insoluble dietary fiber, particle size 28 μm ≧) in a plastic bag, and a twin-screw extrusion tester (Toyo Seiki Co., Ltd. ), Labo Plast Mill), and extruded at a set temperature of 165 ° C. and a rotation speed of 150 rpm, and this was repeated twice to obtain a kneaded pellet.

[Example 3-2]
Kneaded pellets of Example 3-2 were obtained in the same manner, except that the dietary fiber of Example 3-1 was replaced with corn starch (commercial product, particle size: 6 to 25 μm).

[Example 3-3]
Kneaded pellets of Example 3-3 were obtained in the same manner, except that the dietary fiber (particle diameter 28 μm ≧) of Example 3-1 was replaced with dietary fiber (particle diameter 45 μm ≧).

[Evaluation]
Hand tear feeling was compared by the same method as in Test Examples 1 and 2, and a tensile test was performed. Table 3 shows the results.

  It was confirmed that when a mixed resin of PBSA and PHBH was used, brittleness, which was a disadvantage of PHBH alone, was greatly improved (Example). It is presumed that in the system of the mixed resin of PBSA and PHBH, the tensile elongation, which was small with PHBH alone, was improved, and as a result, the feeling of hand tearing was also improved.

  In addition, by shifting the ratio of PBSA and PHBH, the flexibility of PBSA and the strength of PHBH can be freely changed, which can be said to be applicable to a wide range of uses.

<Test Example 4> Mixing of filler into PBS [Production of filler precursor]
(B) The natural polysaccharide filler can be kneaded as it is in the form of powder. However, in order to correct the kneading composition and avoid dust explosion, (B) the natural polysaccharide filler is mixed or added in a high content. In order to promote bonding at the filler interface by mixing the agent, it is effective to produce a precursor by pelletization or granulation by pretreatment.

[Precursor 4-1: Starch]
36 parts of water was added to starch (Corn Starch Y, manufactured by Nippon Shokuhin Kako Co., Ltd.), and the mixture was stirred and mixed, and then granulated with a disk peretta (Dalton Co., Ltd., device name: F-5). This was dried to obtain a precursor 1.

[Precursor 4-2: cellulose fiber]
Cellulose fiber containing 140 parts of water (Health Company, insoluble dietary fiber, particle size 28 μm ≧), 5 parts of polyalphaolefin (Toyoku Oil Co., Ltd., product name: HS Crista 7100-P) and maleic anhydride-modified polypropylene After mixing and stirring 4 parts (Kyaku Akzo Co., Ltd., product name: Kayabrid 002 PP-NW), the mixture was granulated with the above disk pelletizer. This was dried to obtain a precursor 2.

[Precursor 4-3: wood flour]
30 parts of water, 5 parts of the polyalphaolefin, and 4 parts of the maleic anhydride-modified polypropylene were mixed with hinoki wood flour (particle size: less than 300 μm) by stirring and then granulated with the disk pelleter. This was dried to obtain a precursor 3.

(Production of resin composition)
[Example 4-1] Production of resin composition in which natural polysaccharide filler was mixed with polybutylene succinate (Example 4-1-1)
45 parts by mass of the precursor 4-1 was blended with 100 parts by mass of polybutylene succinate (Mitsubishi Chemical Corporation, product name: FZ71), and the mixture was mixed with a twin-screw extrusion tester (Toyo Seiki Co., Ltd., Labo Plastomill). The mixture was kneaded at a set temperature of 160 ° C. and a rotation speed of 150 rpm.

(Example 4-1-2)
To 100 parts by mass of the above polybutylene succinate, 51 parts by mass of the precursor 4-2 were blended and kneaded with the above twin screw extruder under the same conditions as in Example 4-1-1.

(Example 4-1-3)
To 100 parts by mass of the above polybutylene succinate, 22 parts by mass of the precursor 4-1 and 25 parts by mass of the precursor 2 were blended, and the same as in Example 4-1-1 with the twin-screw extruder. Kneaded under the conditions.

(Example 4-1-4)
45 parts by mass of rice flour was blended with 100 parts by mass of the above polybutylene succinate, and kneaded with the above-mentioned twin-screw extruder under the same conditions as in Example 4-1-1.

(Comparative Example 4-1-1)
To 100 parts by mass of the above polybutylene succinate, 51 parts by mass of the precursor 4-3 were blended and kneaded with the above twin screw extruder under the same conditions as in Example 4-1-1.

[Example 4-2] Production of resin composition in which natural polysaccharide filler was mixed with polybutylene adipate terephthalate (Example 4-2-1)
To 100 parts by mass of polybutylene adipate terephthalate (BASF, product name: Ecoflex), 51 parts by mass of the precursor 4-2 were blended and kneaded with the twin-screw extruder at a set temperature of 170 ° C. and a rotation speed of 150 rpm. .

(Comparative Example 4-2-1)
51 parts by mass of the precursor 4-3 was blended with 100 parts by mass of the polybutylene adipate terephthalate, and kneaded with the twin-screw extruder under the same conditions as in Example 4-2-1.

[Evaluation]
[Evaluation of strand extrudability]
The strand extrudability when the biodegradable resin and the natural polysaccharide filler were kneaded with the above twin screw extruder was evaluated. As shown in Table 4, in all of the examples and comparative examples, the strand extrudability was good, and resin pellets uniformly kneaded were obtained.

[Evaluation of hot press molded products]
The pellets obtained in all the examples were hot-pressed into a sheet at 160 ° C to 180 ° C, and the finished shape was evaluated. As shown in Table 4, the hardness and surface condition of the sheet were good for all Examples and Comparative Examples.

[Heat press sheet tear feeling]
In order to measure the strength and toughness of the hot-pressed sheet, the feeling of hand tearing of the hot-pressed sheet strip (thickness: about 0.2 mm, width: 10 mm) was evaluated. Table 4 shows the results. In Table 4, “◎” indicates that the material was not torn even when pulled strongly, “」 ”indicates that the material was torn when strongly pulled, but not torn otherwise, and“ × ”indicates that the material was easily torn. It also indicates that the sheet strip was broken when folded.

  It was confirmed that each of the hot press sheets according to the examples has excellent toughness and strength, and can be used not only by injection molding but also by film molding and sheet molding.

  On the other hand, the hot press sheet according to the comparative example was not able to obtain a sufficient filler dispersion effect and was easily torn. Therefore, it was confirmed that it was difficult to cope with sheet-like hot press molding or the like by the method of the comparative example.

Claims (5)

(A) a biodegradable resin;
(B) containing a natural polysaccharide filler,
At least one kind of the biodegradable resin (A) is a resin that can degrade both soil microorganisms and marine microorganisms, and polybutylene succinate and / or polybutylene succinate adipate can be used as the (A) biodegradable resin. Containing 30% or more of the total mass of the resin,
The (B) natural polysaccharide filler is a biodegradable resin composition containing starch powder or cereal powder having an average particle diameter of 80 μm or less, or polysaccharide fibers having an average particle length of 80 μm or less. The (A) biodegradable resin is capable of decomposing both soil microorganisms and marine microorganisms, including the polybutylene succinate adipate and poly-3-hydroxybutyrate-co-3-hydroxyhexanoate. Resin
The content of the polybutylene succinate adipate is 30% or more based on the total mass of the (A) biodegradable resin,
The biodegradable composition according to claim 1, wherein the content of the poly-3-hydroxybutyrate-co-3-hydroxyhexanoate is 70% or less based on the total mass of the (A) biodegradable resin. Resin composition.   The biodegradable resin composition according to claim 1 or 2, wherein the content of the (B) natural polysaccharide filler is 10 parts by mass or more and 250 parts by mass or less based on 100 parts by mass of the biodegradable resin (A). Master batch consisting of   Agricultural and horticultural multi-sheets, agricultural and horticultural plastic pots, agricultural and horticultural nets, masking films, straws, cutlery, food and beverage packaging containers, tableware, plastic bags, vacuum forming sheets, curing sheets, microbeads, microfibers, drainage nets The biodegradable resin composition according to claim 1 or 2, which is used for one or more uses selected from fishing gear, fishing gear, floating, and artificial algae bed structural members. A biodegradable resin molded article obtained by molding the biodegradable resin composition according to claim 1.