JP6850125B2 - Starch composite intermediate granules - Google Patents

Description

The present invention relates to a starch / resin composite intermediate granule, and more specifically, it is used for a wide range of applications such as food and drink containers, various packaging materials such as sheets and films, cushioning materials, daily necessities, and agricultural products. The present invention relates to a starch / resin composite intermediate granule for producing a starch / resin composite molding processing material containing starch as a main component, which can be biodecomposed or disintegrated in a short period of time when it is disposed of. In particular, we manufacture starch / resin composite molding materials with less variation that have physical properties and molding processability suitable for plastic molding such as vacuum molding, extrusion molding, injection molding (injection molding), inflation molding, and blow molding (injection molding). Concerning starch composite intermediate granules for

Plastic molded products based on petroleum resources are used in a wide range of applications as food and drink containers, various packaging materials such as sheets and films, cushioning materials, daily necessities, agricultural products, and other industrial materials. On the other hand, global warming due to greenhouse gases and depletion of petroleum resources due to mass consumption have become important issues to be tackled on a global scale in the long term. Furthermore, when petroleum-based plastic molded products have been disposed of, they are difficult to decompose and collapse in the natural environment, remain in nature for a long period of time, and pollute the natural environment.

Today, as a raw material for plastic molded products, it has become an alternative material to petroleum, and it does not affect global warming, or it collapses relatively quickly in the natural environment, and as a new material that is friendly to the natural environment, natural materials are attracting attention and warming. As a means of solving the problems of resource depletion and environmental pollution, attention has been paid to biotechnology, which has made great progress in recent years, and the utilization of biomass materials, which are organic resources derived from living organisms, is being particularly promoted.

The use of natural materials such as polylactic acid, starch, modified starch, and cellulose has been proposed as such biomass materials. Biomass materials do not adversely affect the environment because they are finally decomposed in the natural environment even if they are discarded.

Starch is a typical example of a biomass material. Starch is a biomass material that is cheaper than biodegradable resins and other biomass-derived plastics, and can promote biodegradability and reduce energy consumption during incineration. By using starch as a filler, a self-degradable and disintegrating composition can be provided at a lower cost. In addition, starch has been attracting attention in recent years for the purpose of being able to cope with global warming and depletion of petroleum resources and realizing cost reduction, and the proportion of starch being used is increasing.

However, in order to apply biomass materials to a wide range of applications, mechanical properties, thermal properties, melt processability, etc. are required, and many environmentally friendly materials do not have sufficient physical properties and can be molded. Have difficulty.

Therefore, in order to improve physical properties and processability and make it possible to substitute for plastic molding processing materials, polylactic acid, biopolyethylene, starch and cellulose made from biomass are made into composite materials with synthetic resin materials such as polyolefins. (Patent Documents 1 and 2).

Starch is a high-molecular-weight material, and as it is, the normal shape of starch is fine particles, and the density is low. Therefore, dust is likely to fly and the flow stability of the powder is poor, making it difficult to supply a fixed amount. If starch is left as it is, the material lacks fluidity during molding, and there are problems in handleability and molding processability. Further, the starch / resin composite molding processed material formed by the composite of starch and synthetic resin is not stable in terms of uniformity and homogeneity. That is, it is a composite material of starch and plastics having different material forms and properties, and even if the composite molded material can be formed by mixing, the resulting product will have variations in the physical properties and properties of the entire product. Not only is the amount used limited naturally for compounding, but when the amount used is large, a special quantitative feeder or molding machine that forcibly supplies starch is required. Therefore, it is also a factor that pushes up the manufacturing cost.

The starch / resin composite molding processing material with little variation can be obtained by various molding methods, for example, extrusion molding, T-die extrusion molding, injection molding, vacuum molding, etc., to obtain various packaging materials and disposable products such as shopping bags. Manufactures garbage collection bags, disposable lunch boxes, cups, food trays, knives, forks, spoons, toothbrushes, combs and agricultural products such as agricultural bags, seedling pots, cultivation sets, compost bags and cushioning materials, food and drink containers, etc. In recent years, the produced molded articles have been imparted with degradability or disintegration property, can be quickly reduced in volume, and have begun to be used in place of petroleum-based synthetic resin molded articles as environmentally friendly molded articles.

In order to produce a molding material containing starch as such an environment-friendly material, it is necessary to consider reducing the amount of synthetic resin added, and when the amount of starch is increased, the machine becomes a starch / synthetic resin composite material. There is a problem that the amount of starch added and the degree of freedom of molding are limited because the characteristics and moldability are deteriorated.

Japanese Unexamined Patent Publication No. 2001-64458 Japanese Unexamined Patent Publication No. 2004-155842

INDUSTRIAL APPLICABILITY The present invention is a composite molding of a starch / resin, which is uniform and homogeneous, has excellent physical properties, is also excellent in molding processability and workability in various molding methods, and has little variation even if it contains 50 parts by weight or more of starch. The purpose is to provide a raw material or composition capable of stably and efficiently producing a processed material, and as a raw material capable of reliably forming a starch / resin composite molding processed material, in terms of workability and quantitativeness. Provided are a starch / resin composite intermediate granules which are excellent, have morphological stability, are excellent in molding processability in various molding processing methods, are inexpensive, and can be stocked.

More specifically, the present invention is a starch-resin composite in which a granular material of a thermoplastic resin is used as a core portion, and the surface of the core portion is coated with a coating layer of a powder or granular material containing starch containing a low melting point additive. Provides intermediate granules.

As a result of diligent studies to solve the above problems, the present inventors have made the starch-resin composite intermediate granules of the present invention a granular material of a thermoplastic resin as a core portion, and the surface of the core portion is low. A starch-resin composite intermediate granule having a coating layer of a powder or granular material containing starch containing a melting point additive, which is uniform and homogeneous even when a high concentration of starch is contained, and has morphological stability. Moreover, as a starch / resin composite molding processing material, it is possible to obtain physical properties and properties having excellent molding workability and workability in various molding processing methods.

Then, the mixture is heated and stirred in a high temperature stirrer, and cooled and stirred in a cooling stirrer to a temperature near the melting point temperature, which is lower than the melting temperature of the high melting point additive and higher than the melting temperature of the low melting point additive. It can be manufactured easily and inexpensively by the process. Moreover, the starch / resin composite intermediate can be stocked in the form of composite granules as a raw material for a molding processing material by a manufacturing method including immediately discharging and stocking the formed starch / resin composite intermediate particles. It is a granule.

More specifically, the starch-resin composite intermediate granules of the present invention are in a molten state with starch by heating and stirring a raw material containing 50 parts by weight or more of starch and a low melting point additive such as a glycerin-based ester. The low melting point additive is mixed, entwined with starch, adhered and contained in starch. After that, at least a granular material of a thermoplastic resin and a refractory additive such as a fatty acid metal salt are added, and the mixture is heated, mixed and stirred to obtain a fluid starch / resin composite material.

Then, while stirring the fluidized starch / resin composite material, the temperature is lowered by cooling and stirring to a predetermined temperature higher than the melting temperature of the low melting point additive in a cooling stirrer, and at least the high melting point addition in the molten state is added. By resolidifying the agent, a granular thermoplastic resin is used as the core part, and the surface of the core part is resolidified with a high melting point additive such as a fatty acid metal salt, and the surface of the starch is wetted with a low melting point additive. A starch-resin composite intermediate granule having a structure in which a thermoplastic resin is used as a core portion and the surface thereof is covered with a coating layer of a powder or granular material containing at least the starch due to the presence of the starch that is dispersed, adhered and contained. It forms a starch-resin composite intermediate granule in the form of.

It was possible to provide a starch / resin composite intermediate granule, which is an intermediate raw material capable of producing an excellent starch / resin composite molding processed material having little variation of the present invention, and achieved the above object.

Then, by using the starch / resin composite intermediate granules of the present invention, which could not be obtained in the past, even if starch is contained in a high concentration, it is uniform and uniform with little variation, flow stability, and various molding processes. A starch / resin composite molding material having excellent moldability, handleability, and workability that can be used in the method can be stably obtained at low cost.

The starch-resin composite intermediate granules of the present invention can form relatively uniform granule sizes, have good fluidity, can be stably supplied, and can be easily quantified. In addition, it has become possible to prepare raw materials for molding materials for molding with almost no starch falling off.

The starch / resin composite intermediate granules of the present invention provide a starch / resin composite intermediate granules having excellent handleability, material quality uniformity, and storage stability by forming the starch / resin composite intermediate granules. It is possible to stably supply raw materials having different shapes as raw materials.

Specifically, by forming a starch / resin composite intermediate granule, even if 50% by weight or more of biomass, for example, industrial corn (dent corn) starch is added, the starch is a granular starch of powdery biomass and a thermoplastic resin. -Even if it is a molding material made of a resin composite material or a composite material made of raw materials having different shapes and forms, including additives such as a dispersant and a compatibilizer, it is easy to handle and is a raw material. It enables stable supply to the manufacturing process, homogenizes and homogenizes sheet-like materials, and can form starch / resin composite molding processed materials with little variation. Further, it is possible to provide a starch / resin composite molding material having excellent molding processability suitable for molding such as extrusion molding, T-die extrusion molding, vacuum molding, injection molding, inflation molding and calendar molding.

The present invention makes full use of a compounding technique such as an additive that brings the interface between starch and a thermoplastic tree closer to the molding processability and the bias of mechanical properties of the material to be formed even when starch of 50 parts by weight or more is blended. By devising not only the material composition but also the processing conditions, the molding processability of the starch / resin composite intermediate granules can be improved, the mechanical properties can be improved, the generation of starch odor can be suppressed, and the color fades. Can be suppressed.

For the sheet produced using the starch-resin composite intermediate granules of the present invention, all raw materials including starch are selected from the positive list, and LCA is carried out in the environmental impact assessment to reduce carbon dioxide, for example. It was revealed that a carbon dioxide reduction effect of 32% can be obtained as compared with the life cycle of polypropylene sheet.

By producing a molding processing material using the starch / resin composite intermediate granules of the present invention, when it is used as a packaging material, it has sufficient product strength when used, but it can be crushed with a light force after use, so that it is dust. Can contribute to volume reduction. In addition, a carbon dioxide reduction effect can be obtained in the environmental impact assessment. As described above, as a starch / resin composite material, it can be used as a more suitable environment-friendly material as a substitute material for petroleum-based plastics, and various food containers and packaging materials, cushioning materials, daily necessities, and agriculture. It has become fully applicable to commercial products.

A conceptual diagram of an apparatus for manufacturing a starch / resin composite molding material of the present invention. Photograph of the starch / resin composite intermediate granules of the present invention Photograph of starch / resin composite intermediate granules of comparative example Schematic diagram of the starch-resin composite intermediate granules of the present invention

(Starch / resin composite intermediate granules)
The starch / resin composite intermediate particles of the present invention described above will be described in more detail below.
The starch / resin composite intermediate granules of the present invention are indispensable for obtaining a starch / resin composite molding processing material having excellent uniformity and homogeneity and less variation even if the starch is contained in an amount of 50% by weight or more. Therefore, it is positioned as a raw material in the manufacturing process of a starch / resin composite molding processing material. The starch / resin composite intermediate granules of the present invention can be easily and surely manufactured in the process of manufacturing the starch / resin composite molding processing material, or can be separately manufactured, supplied as a raw material, and used in the manufacturing process. It is a composite intermediate granule with excellent morphological stability.
Then, by using the starch / resin composite intermediate granules as a raw material in the manufacturing process of the starch / resin composite molding processing material, it is possible to stably manufacture the molding processing material.

More specifically, the starch / resin composite intermediate granules according to the present invention are prepared by heating and stirring starch and a low melting point additive to melt the low melting point additive, mixing it with starch, and melting the low melting point additive. Is entwined with starch and adhered to form starch containing a low melting point additive. Then, the composite raw material containing the thermoplastic resin granules and the high melting point additive is further added and heated and stirred to melt and mix the high melting point additive to melt and mix the starch, the thermoplastic resin granules and the low melting point in the molten state. And the composition containing the high melting point additive is uniformly dispersed to prepare a fluid starch / resin composite material. After that, the fluid starch / resin composite material is cooled and stirred, and the molten mainly high melting point additive is resolidified to form a thermoplastic resin as a core portion, and the surface thereof contains starch containing a low melting point additive. It is produced as a starch-resin composite intermediate particle having a coating layer of a powder or granular material.

(starch)
The starch-resin composite intermediate granules of the present invention can be obtained as a composite intermediate granule having a stable quality component composition by heating and stirring the component raw materials and then cooling and stirring without using special means and equipment. Is something that can be done. As the raw material starch used as a biomass material for forming a starch-resin composite intermediate granule in the present invention, inexpensively available raw starch can be used, for example, corn starch, bean starch, tapioca starch, potato starch, and the like. Examples thereof include wheat starch, rice starch, fox starch, mustard starch, lotus starch, sago starch, warabi starch, and waste starch.

In addition, physically modified starch can also be used, and examples thereof include pregelatinized starch and moist heat starch. Further, starch chemically modified to the extent that it does not affect biodegradability can also be used. For example, acetoacetate esterified starch, acetate esterified starch, hydroxymethyl etherified starch, hydroxypropyl ether starch, carboxymethyl etherified starch, etc. Allyl etherified starch, methyl etherified starch, succinic acid esterified starch, xanthogen acetic acid esterified starch, nitrate esterified starch, urea phosphate esterified starch, phosphoric acid esterified starch, phosphoric acid crosslinked starch, formaldehyde crosslinked starch, achlorine Examples thereof include crosslinked starch and epichlorohydrin crosslinked starch.
In the present invention, as starch, at least one or more of raw starch, physically modified starch or chemically modified starch can be used alone or in combination of two or more. Preferably, raw starch is used.

(Polymer material)
In the present invention, the components of the starch / resin composite molding processing material include at least a thermoplastic resin in order to modify the molding processability and physical properties. In the present invention, a biodegradable material can also be used as a granular polymer material serving as a core portion in order to increase the ratio of the biodegradable material without lowering the biodegradability.
As the thermoplastic resin used in the present invention, polyolefin resins such as polyethylene and polypropylene, polystyrene, polyamide, polyester, ethylene / vinyl acetate copolymer, alkylene / acrylate or methacrylate copolymer and other thermoplastics are used. Can be used. Preferably, a polyolefin resin such as polyethylene or polypropylene is used. In particular, polypropylene is preferably used.

As the thermoplastic resin, pellet-shaped granules are used, and in order to form the uniform and homogeneous starch / resin composite molding processed material of the present invention, it may be in the range of 20% by weight or more and less than 50% by weight. preferable. When the thermoplastic resin content is less than 20% by weight, the amount of starch having a small specific gravity is large as the obtained starch / resin composite molding material, and it becomes difficult to homogenize the biomass molding material, so that a homogeneous composite molding material can be obtained. It becomes difficult. Moreover, it is necessary to increase the amount of the additive. As a result, the mechanical properties are significantly deteriorated, uneven thickness, tearing and the like occur during molding, it becomes difficult to mold thin and deep objects, texture cannot be obtained, and molding processing becomes difficult.

On the other hand, when the thermoplastic resin content is 50% by weight or more, the starch is positioned as a modifier for the thermoplastic resin, for example, as a filler, and the obtained starch / resin composite molding material has physical properties as a plastic molding material. Although the properties are strong and molding is possible, it is difficult to reduce the volume, the contribution to the reduction of greenhouse gas emissions is reduced, and it becomes difficult to obtain a starch / resin composite molding processed material as a biomass raw material. .. Moreover, since there are many fillers, the physical properties of the molded material and the uniformity and homogeneity of the composite material fluctuate greatly, and a stable material cannot be obtained.
When the starch-resin composite intermediate granules of the present invention are no longer formed, even if a molded material is produced from a material having the same composition of each component of the raw material, the physical properties of the molded material and the uniformity and homogeneity of the composite material are maintained. Fluctuations are large and stable materials cannot be obtained.

Examples of the biodegradable material forming the core include cellulose derivatives such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, and hydroxybutyl methyl cellulose, polyvinyl alcohol, carboxymethyl cellulose, and polyacrylic acid. Polymers, hydrophilic polymer materials such as polyacrylamide, various acrylates, ethylene / vinyl acetate copolymers, emulsions such as polyurethane, caprolactone, which is an aliphatic polyester resin, polylactic acid, polybutylene adipate, polybutylene succinate, poly Biodegradable resins such as hydroxybutyrate / variate copolymers can be mentioned.

In the present invention, the fluff formed by crushing the composite intermediate granules, sheets or post-molded debris formed in the manufacturing process into granules is also a starch / resin composite material or a biodegradable material made of a starch material. , Can be reused and used as a granular material to be a core portion together with a thermoplastic resin.

In the present invention, the average particle size of the granular material of the thermoplastic resin used is in the range of 1 to 10 mm on the major axis and 1 to 10 mm on the minor axis. If the size exceeds or is smaller than the size of this major axis, the balance of the amount of adhered granules becomes unbalanced, and all of them are uniform and homogeneous as starch / resin composite intermediate granules of starch and thermoplastic resin. Is inferior, and further, the dispersibility of both in the molded product is inferior. Due to the presence of granules having a large particle size, the physical properties and the appearance of the product are also inferior. The thermoplastic resin used in the starch / resin composite molding material of the present invention is comprehensively considered that it can effectively form powders and granules with a small amount, has good molding processability, and does not affect the appearance of the product. , The average particle size in the above range was used.

(Additive)
In the present invention, the fluid starch / resin composite material is formed to form the starch / resin composite intermediate granules. Therefore, in the step of heating and stirring, the additive is entangled with the starch or the thermoplastic resin and adheres to the starch. And to make it easier for the thermoplastic resin to adhere, and to allow the starch and thermoplastic resin granules to retain the properties of the fluid starch-resin composite material, further cooling and stirring, at least high. When the melting point additive is resolidified, it is necessary to add an additive that can act as an adhesive that enables stable formation of the starch / resin composite intermediate granules.
Further, when the starch / resin composite molding material is extruded, it functions as a dispersant that uniformly disperses the starch and the thermoplastic resin, and further melt-kneads and extrudes the melted resin and the unmelted starch without material deterioration. Add an additive that can impart slipperiness to allow.
In the present invention, an additive that functions so as to obtain a starch / resin composite molding process material having excellent molding processability, mechanical strength, etc. and having little variation by adding the additive is selected and used.

(Low melting point additive)
In the present invention, as an additive that functions as described above, it is a powder immediately after being added, but it becomes a molten state as the temperature of the material rises, and by adhering to starch, it becomes easier for the starch to adhere to the thermoplastic resin, and the starch and starch. Additives that increase internal slipperiness are used so that they are mixed uniformly and uniformly and work to increase the fluidity of the starch. The additive has a melting point temperature lower than the melting temperature of the thermoplastic resin and melts at a relatively low temperature, for example, 100 ° C. or lower, preferably 60 to 100 ° C., and is viscous. , Additives that can function to entangle and adhere to the powder are used. In the present invention, an additive that is simultaneously present in the starch / resin composite intermediate granules and that can fulfill at least the above-mentioned properties and functions, is melted at a relatively low temperature, is entangled with starch, and is attached and added. Defined as "low melting point additive".

Examples of low melting point additives include monoglyceride, diglyceride, triglyceride, acetylated monoglyceride, organic acid monoglyceride, medium chain fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, special fatty acid ester, and higher alcohol fatty acid ester. Be done. Preferably, a low melting point additive such as a glycerin-based fatty acid ester is used.

The amount of the low melting point additive added is preferably 0.1 to 10.0% by weight. If it is 0.1% by weight or less, the function as an adhesive is insufficient, and if it is 10% by weight or more, the raw material becomes sticky, the flow agitation property is lowered, and starch balls are formed. The formation of a fluid starch mixture in a high temperature stirrer is delayed, and the production efficiency is lowered. Then, yellowing of starch is observed as the heating time becomes longer.

(High melting point additive)
In the present invention, an additive having a melting point higher than that of the low melting point additive which is melted at a relatively low temperature, entangled with starch, and adhered to the starch / resin composite intermediate granules at the same time is further added. This additive has a higher melting point than the low melting point additive described above, preferably in the range of 100 to 150 ° C., and is an additive that solidifies before the low melting point additive and is thermoplastic. It has a melting point lower than the melting temperature of the resin, and when cooled and stirred, it resolidifies before the low melting point additive, and the thermoplastic resin is used as the core part, and the low melting point additive is attached to the surface of the core part. It plays a role of adhering the coating layer of the powder or granular material containing the starch contained in the starch to form the starch / resin composite intermediate particle.

The high melting point additive further removes starch from the starch-resin composite intermediate granules until it is used to produce a molding process material, and the composite intermediate granules do not fall off or disintegrate the intermediate granules. It is an additive that functions to maintain the shape of the body.
For the high melting point additive, it is necessary to consider the type of thermoplastic resin and the affinity with the additive, but starch / resin composite molding processing is uniform and uniform in the processing machine using starch / resin composite intermediate particles as raw materials. In order to use it as a material, the composite raw material is dispersed, and when melt-kneaded as a starch / resin composite material, it is uniformly dispersed, and moreover, the friction with the processing machine is reduced, the fluidity in the processing machine is increased, and the external slipperiness is enhanced. Additives capable of imparting sex are preferably used.

In the present invention, an additive that is simultaneously present in the starch / resin composite intermediate granules and is melted at a relatively high temperature, which can fulfill at least the above-mentioned properties and functions, is defined as a "high melting point additive". ..

In the present invention, the high melting point additive capable of forming a starch-resin composite intermediate granule, improving the dispersibility during melt-kneading, and imparting slipperiness includes fatty acid metal salts, hydrocarbon-based additives, and higher grade additives. Alcohol-based, aliphatic amide-based, fatty acid esters and the like can be used. In the high melting point additive of the present invention, the fatty acid metal salt is a metal salt of a saturated or unsaturated fatty acid having at least 10 carbon atoms, and a fatty acid-based substance such as stearic acid can be preferably used.

Specific examples thereof include magnesium stearate, zinc stearate, calcium stearate, aluminum stearate chain, sodium lauryl sulfate, magnesium lauryl sulfate, potassium benzoate, sodium benzoate, and sodium stearyl fumarate. At least one of these can be used.
The content of the refractory additive is preferably 1.0 to 15% by weight.

The present invention uses two or more of the above-mentioned low melting point and high melting point additives, and enhances adhesion and fluidity to starch and resin during heating and stirring, and resolidifies when cooling and stirring. The additive is selected so that the starch / resin composite intermediate granules of the present invention are automatically formed. Then, by using the formed starch / resin composite intermediate granules as a raw material and melting or melt-kneading the composite intermediate granules in a processing machine, a uniform and homogeneous composite material can be obtained, and melt extrusion is possible. By adding the necessary compounding agent to the starch / resin composite molding processing material, which is the product of the present invention, a product having the necessary physical properties and molding processability can be obtained.

(Other additives)
By using the starch / resin composite intermediate granules of the present invention, it is possible to obtain a uniform and uniform starch / resin composite molding processing material with little variation, and it has molding workability in various molding processing methods and has workability. In order to obtain excellent materials, it can be processed and used for various purposes such as food containers, packaging materials such as sheets and films, cushioning materials, daily necessities, and agricultural products. , It is preferable to select and use an additive. At that time, various additives other than the above-mentioned starch, thermoplastic resin and the above-mentioned additives are selected according to each application and required physical properties and functions, and one or more kinds are selected as long as the object of the present invention is not impaired. Can be added in combination.

In the present invention, a compatibilizer can be added in order to improve the affinity between the starch and the thermoplastic resin. As the compatibilizer, acid-modified polyolefin, acid-modified nylon, acid-modified polystyrene, acid-modified EVA, acid-modified ethylene copolymer polymer, acid-modified acrylate, acrylic acid-modified EVA, modified ethylene acrylate and the like can be used.

Examples of the additive used for producing the starch / resin composite molding processing material, which is a product produced through the starch / resin composite intermediate granules of the present invention, include titanium oxide, carbon black, dye, pigment, etc., as required. Colorants can also be used. In addition, if necessary, additives such as elastomer, antioxidant, cross-linking agent, ultraviolet absorber, and foaming agent can be appropriately added.

The shape and size of the starch-resin composite intermediate particles of the present invention can be appropriately determined in consideration of the shape and diameter of the granular materials of the granular thermoplastic resin mixed with the starch. The size of the granules of the present invention has a diameter in the range of, for example, 1 to 10 mm and a length in the range of 1 to 10 mm.

In the starch / resin composite intermediate granules of the present invention, as described above, the fluid starch / resin composite material formed by the high temperature stirrer is resolidified in the cooling stirrer to form the core part of the thermoplastic resin of the granules. A form having a coating layer whose surface is coated with a powder or granular material containing starch as a main component can be obtained.

Since the starch / resin composite intermediate granules of the present invention are used to produce a starch / resin composite molding process material, the starch / resin composite intermediate granules do not lose their shape until they are melt-kneaded, and the starch does not peel off. It has morphological stability attached by the adhesive force of the above, and can be formed in a stable state as a composite intermediate granule material. As a result, in the production of a molding material made of a biomass / resin composite material containing starch as a main component, there is little variation as a composite molding processing material, and the uniformity, homogeneity, molding workability, workability and quantitativeness are improved. Connect.

(Manufacturing of starch / resin composite molding processing material)
In the production of the starch / resin composite molding processed material using the starch / resin composite intermediate granules of the present invention, for example, a material having a component composition constituting the starch composite intermediate granules of the present invention is used as a raw material, or the starch of the present invention is produced. -Assembled as a method of continuously and consistently manufacturing starch / resin composite molding processed materials, which are products, using resin composite intermediate particles as raw materials, and starch / resin composite molding processed materials shown in FIG. 1 are continuously consistently manufactured. This is done by using a manufacturing device.

The starch / resin composite molding processing material continuous integrated manufacturing apparatus includes the starch / resin composite intermediate particle manufacturing apparatus unit A capable of producing and storing the starch / resin composite intermediate granules capable of producing the molding processing material, and the above-mentioned Using the manufactured composite intermediate granules as a raw material, a starch / resin composite molding process that is a product is manufactured, and / or secondary processing such as calendar molding is performed to manufacture a raw material for the final product. It is composed of an apparatus including a material manufacturing apparatus section B.

In the production of the starch / resin composite intermediate granules of the present invention, the production apparatus consisting of each apparatus shown in the starch / resin composite intermediate granule production apparatus A of the continuous integrated production apparatus for the starch / resin composite molding processing material is used as an independent apparatus. , Or, as illustrated, a high temperature stirrer 1 which is manufactured by a device incorporated as a part of a continuous integrated device and is heated and stirred to form a starch mixture of starch and a melted low melting point additive, and starch. A cooling stirrer 2 that cools and stirs to form the composite intermediate granules from a starch / resin composite material containing a thermoplastic resin granule and a low melting point and high melting point additive, and a granulated starch / resin composite intermediate grain. Manufactured using a manufacturing apparatus including a stock tank and supply apparatus 3 that can be used as a supply buffer for composite intermediate granules as a raw material so that the body can be stocked and a starch / resin composite molding processing material can be continuously produced. Will be done.

Then, the starch / resin composite molding processing material is produced in the apparatus unit A that manufactures the starch / resin composite intermediate granules, and the stock tank / supply device that supplies the stored starch / resin composite intermediate granules as a raw material. 3. The twin-screw extruder 4 in which the raw materials are heat-kneaded and extruded into a fluid starch / resin composite material, and the thermoplastic resin portion in the kneaded and melted state is further raised in cylinder temperature to further raise the cylinder temperature to melt thermoplastic resin starch. It can be manufactured by the starch / resin composite molding processing material manufacturing equipment unit B having a configuration including at least a uniaxial extruder 5 extruded as a composite molding material, and the starch / resin composite molding processing material manufacturing equipment unit can be manufactured by the starch / resin composite. A continuous integrated manufacturing apparatus is formed by arranging the intermediate granules in succession to the apparatus A, or the starch / resin composite molding processing material manufacturing apparatus B is used as a single manufacturing apparatus and the starch / resin composite intermediate grains are used as raw materials. The body can be prepared separately and used as a batch manufacturing device.

The starch / resin composite molding material continuous integrated manufacturing apparatus used in the present invention is further extruded into a sheet, and the sheet can be roller-rolled by calendar forming to control the thickness of the sheet and the formation of the surface layer. The device 6 and a cutting device for pelletizing by extruding in a strand shape and cutting or extruding in a sheet shape and cutting on the grain of a sword can be included.

(Manufacture of starch / resin composite intermediate particles)
The starch / resin composite intermediate granules of the present invention can be produced by the apparatus unit A including the high temperature stirrer and the cooling stirrer shown in FIG.

In the starch-resin composite intermediate granules of the present invention, first, at least one of starch and low melting point additive is placed in a high temperature stirrer at a temperature lower than the melting temperature of the thermoplastic resin and higher than the temperature at which the low melting point additive melts. Mix while heating and stirring with, and control the heating and stirring so that the mixture of starch and the melted low melting point additive is obtained.

After that, a refractory additive such as a thermoplastic resin or a metal fatty acid salt is added, and if necessary, other additives are added so as to have the physical properties and properties required for the molding material, and the mixture is further heated, stirred and mixed to flow. Form a sex starch / resin composite material.
Next, the formed fluid starch / resin composite material is transferred to a cooling stirrer, and the melted additive is resolidified while cooling and stirring in the cooling stirrer.
A starch in which a granular material of a thermoplastic resin is formed as a core portion by mainly resolidifying a high melting point additive, and a coating layer of a powder or granular material containing starch mainly containing a low melting point additive is formed on the surface of the core portion. Manufacture resin composite intermediate particles.

(Heating and stirring with a high temperature stirrer)
(1) Heat-stirring treatment of starch and low-melting-melting additive In the heating-stirring treatment of the present invention, starch and low-melting-melting additive are heated and mixed by heating and stirring starch and low-melting-melting additive in a high-temperature stirrer. It is to be done as follows.

First, starch and a low melting point additive such as a glycerin-based fatty acid ester are mixed and charged into the high-temperature stirrer 1, heated and stirred to raise the temperature.
In the heating and stirring treatment, the heating temperature is set to be equal to or higher than the melting point temperature of the low melting point additive, the low melting point additive is melted, and the temperature at which the low melting point additive can maintain the molten state, for example, the melting point temperature of the low melting point additive. By setting the temperature higher by 10 to 20 ° C or higher than the melting point temperature of the high melting point additive and controlling the rotation speed and stirring time, the starch powder and the melted low melting point additive are entangled and the low melting point is obtained. The temperature, rotation speed, stirring time, etc. are controlled and treated in consideration of production efficiency so that a fluid starch mixture of the starch containing the additive is formed.

In the heating and stirring treatment of the present invention, the high temperature stirrer is set to, for example, a heating temperature of 110 to 160 ° C. and a rotation speed of 5 to 50 Hz, and the rotation speed and the stirring time are controlled to melt the components of the low melting point additive. And stir and mix the starch and low melting point additive in a high temperature stirrer. By this treatment, a melted low melting point additive is attached to and contained in the starch to form a starch mixture containing the low melting point additive. At that time, the low melting point additive is entwined all over the starch.

In the heat-stirring treatment of the present invention, the temperature is preferably 100 ° C. or higher in consideration of the production time and production efficiency. It is preferable to avoid yellowing of starch by adjusting the temperature and time. Further, in order to mix quickly and evenly without any problem of yellowing and production efficiency, it is preferable to adjust the stirring state, the number of rotations, the shearing force and the like.

(2) Formation of starch / resin composite material After making a mixture of starch and melted low melting point additive with a high temperature stirrer, granules of thermoplastic resin and high melting point additive such as at least one fatty acid metal salt are added. Add more and heat and stir.
In the present invention, the temperature at the time of heating and stirring is set to be equal to or higher than the temperature at which the high melting point additive melts and below the melting temperature of the thermoplastic resin. It can be set to a melting temperature or higher and the heating temperature is fixed. For example, it is set to 110 to 160 ° C., and at least two kinds of low melting point and high melting point additives are melted and mixed by stirring. Then, in a state where the low melting point and high melting point additives are melted, by heating and stirring while controlling the rotation speed and the stirring time, the granules of starch and the thermoplastic resin and the melted low melting point and high melting point additives can be obtained. It is agitated and mixed to form a uniformly dispersed mixture of fluid starch / resin composite material.

(Cooling and stirring treatment with a cooling stirrer)
The mixture of the fluid starch / resin composite material obtained in the high temperature stirrer is transferred to the cooling stirrer, and is kept above the melting temperature of the low melting point additive component in the cooling stirrer until near the melting temperature. It is cooled with stirring, and the mixture is cooled and stirred so that the molten additive component is resolidified.

By stirring the starch / resin composite material while cooling it in a cooling stirrer, the temperature of the fluid starch / resin composite material is lowered, and the components of the refractory additive such as fatty acid metal salt are mainly kept below the melting temperature. It is cooled and stirred so that it is solidified by becoming solidified. At that time, the high melting point additive in the mixture of the fluid starch / resin composite material is cooled and stirred to solidify into a state of being attached to the surface of the granular material of the thermoplastic resin, and the low melting point addition with fluidity is added. By adhering the agent-containing starch to the thermoplastic resin granules via at least a high melting point additive that resolidifies, the thermoplastic resin granules become the core portion, and at least the low melting point is applied to the surface of the core portion. A coating layer of a powder or granular material containing a starch containing an additive is formed, and a starch / resin composite intermediate particle body as shown in FIG. 2a is formed. The starch / resin composite intermediate granule has the structure shown in FIG. 3 when its cross section is schematically shown.

In the starch / resin composite intermediate granules of the present invention, raw materials of difficult-to-mix component materials having different properties and shapes are heated and mixed, and then the fluid composite material is cooled while stirring, so that the temperature of the fluid composite material is lowered. As a result, when the melted additive component becomes lower than the melting temperature, it can be solidified to form a starch / resin composite intermediate granule, and can be easily granulated by a simple operation of cooling and stirring.

Conventionally, in the production of molding materials, component raw materials having different properties and shapes have been supplied individually or in batches to the manufacturing process, respectively, as a raw material in a composite form called a composite intermediate granule with good handleability in the manufacturing process. It is possible to stably supply and quantify raw materials in the production of starch / resin composite molding processed materials.

The starch / resin intermediate granules are made of thermoplastic resin granules by controlling the temperature, rotation speed, stirring time, etc. in the granulation process by cooling and stirring operation, and resolidifying the components of the additive in the molten state. By observing and confirming the state in which a coating layer of powder or granular material containing starch is formed on the surface, granulation is performed by cooling and stirring at an optimum temperature, and the shape and shape of the formed granular material are maintained. Can be taken out. If the amount of the low melting point additive and the high melting point additive added is small in the process of forming the composite intermediate granules, the starch adheres to the coating layer, probably because the affinity between the starch and the granular material of the thermoplastic resin is lowered. It could not be extruded because it remained in powder form or starch was shed from the coating layer, resulting in a mixture of composite intermediate particles and powder (see FIG. 2b). When the composite intermediate particles are discharged at a temperature sufficiently higher than the melting temperature of the low melting point additive, the powder particles of the surface coating layer can be fluidly deformed, so that the shape and shape of the particles are deformed by the impact at the time of dropping. It loses its shape and the granules become lumpy, which reduces the flow stability.

In the present invention, while observing the appearance of the granulated granules and confirming that the appearance is in good condition, the components of the low melting point additive are discharged from the cooling stirrer in a temperature range where solidification does not proceed and stocked. It is dropped into a tank, taken out as an intermediate raw material in the form of a starch / resin composite intermediate particle, and stocked. The starch / resin composite intermediate granules thus obtained are composite intermediate granules having excellent morphological stability with almost no powder falling off, and by using this starch / resin composite intermediate granules as a raw material, high-quality starch is produced. -A resin composite molding processing material can be formed.

The starch / resin composite intermediate granules produced by the heating and cooling stirring steps are produced in a batch manner, while in the production of the starch / resin composite molding processed material, the intermediate granules are continuously kneaded. Since it is a raw material to be extruded, storing the starch / resin composite intermediate granules in a stock tank provides a buffer amount for incorporating the intermediate granules into the production of the starch / resin composite molding processing material, and the starch / resin with little variation. It can be used so that the composite molded material can be continuously and consistently produced.

INDUSTRIAL APPLICABILITY According to the present invention, a starch / resin composite intermediate granule having good morphological stability without powder falling can be produced by a simple and few operations as described above, and a starch / resin composite molding processing material having little variation in quality can be produced. It can be used as an intermediate raw material for obtaining, and it becomes possible to stably and inexpensively prepare a uniform and homogeneous starch / resin composite molding processed material, and it is possible to stably use and provide a biomass composite material.

(Manufacturing of starch / resin composite molding processing material)
Since the starch / resin composite intermediate granules produced by the method for producing the starch / resin composite intermediate particles of the present invention are aggregate starch / resin composite materials in which each component material coexists, various molding processing methods are used. In order to produce the starch / resin composite molding processing material of the above using the starch / resin composite intermediate granules as a raw material, a method of producing the starch / resin composite intermediate granules is performed during the production process of the starch / resin composite molding processing material. As a production line that enables stocking as an intermediate raw material for starch / resin composite molding processing materials by incorporating it, or as a production line for composite intermediate grains separately from the production process for starch / resin composite molding processing materials. By providing it, it is possible to stably supply raw materials with different properties and shapes, and it is possible to supply starch / resin composite intermediate particles as raw materials for continuous production of starch / resin composite molding processing materials with little variation. Available.
The starch / resin composite molding material produced from the starch / resin composite intermediate granules is further molded into a sheet or film, blow molded, or vacuum formed and used as a molding material for the final product. You can also do it.

Specifically, in order to produce a starch / resin composite molding processing material that can be used in various molding processing methods from the stocked starch / resin composite intermediate particles of the present invention, it is similar to a normal plastic molding processing technique. In addition, for example, the starch / resin composite intermediate granules are directly put into the twin-screw extruder without the need to mix starch and additives with a mixer such as a Hensiel mixer, a tumbler type mixer, a barbary mixer, or a kneader mixer. The starch and the thermoplastic resin can be uniformly kneaded and mixed by supplying the mixture, controlling the rotation speed, stirring time, temperature, and the like in the same manner as in normal plastic molding, and heating and kneading.

In the process of heating and kneading the starch-resin composite intermediate granules of the present invention in a twin-screw extruder, the heat processing temperature (cylinder temperature) is 100 ° C to 190 ° C, the temperature below the temperature at which the thermoplastic resin melts, and the additive. As a preliminary step to form a molten resin starch composite mixture of a fluid starch / resin composite molding process material, the temperature is set to a temperature equal to or higher than the melting temperature of the above, and the mixture is sufficiently stirred and kneaded while suppressing shearing and temperature rise. .. As a result, the material can be kneaded uniformly without deterioration or fading, and a starch / resin composite molded material that is uniform and has little variation can be produced.

Then, the starch / resin composite intermediate granules of the present invention are subjected to sufficient heating and kneading, and then the fluid starch / resin composite material is extruded by a uniaxial extruder to exceed the melting temperature of the thermoplastic resin in the same manner as in the melt extrusion step of plastics. , 150 to 220 ° C., the extrusion pressure is appropriately set, and the thermoplastic resin is melt-extruded in a stable state, so that it can be used for producing a uniform and uniform starch / resin composite molded material with little variation.

In the present invention, upon extrusion, manufacturing of a molded product by an extruder, production of a sheet by a T-die extruder, production of a film by an inflation molding machine, production of a sheet by a calendar molding machine, production of a molded product by an injection molding machine, etc. It can be used to manufacture starch / resin composite molding processing materials suitable for various molding processing methods by adopting molding processing technology and molding processing machines.

For example, the starch / resin composite intermediate granule of the present invention is obtained by setting the temperature to 150 to 220 ° C. using a T-die and extruding the starch / resin composite molded material as a sheet to obtain a sheet-shaped molded material. Can be used for.

Immediately after being extruded, the obtained sheet-like material is cooled while being sheeted by a rolling roller to form a starch / resin composite molded material sheet, and the cooled starch / resin composite having a thickness of 0.1 to 2.0 mm is obtained. To obtain a molded sheet and use it as a raw material sheet for various molding methods, or to crush or cut the sheet to obtain granules to produce a molded material for raw material pellets suitable for injection molding, inflation molding, and blow molding. Can be used for.

For a starch / resin composite molded material sheet that has been extruded into a sheet by an extruder, the temperature of the take-up roll is set to 60 ° C. or lower, and the sheet formed to a predetermined thickness is cooled, taken up, and wound up. The raw fabric sheet of the starch / resin composite molding processing material is made into a raw fabric roll by, or the raw fabric sheet of the starch / resin composite molding processing material is passed between three rolling rolls in which the surface is cooled by giving the roll a cooling function, and the thickness is increased by the rolling roll. It can also be a controlled, molded material sheet with a surface skin layer formed. Alternatively, it can be a molded material sheet without a surface skin layer.

By controlling the thickness of the starch / resin composite molding material sheet, the presence / absence and thickness of the surface skin layer, and further controlling the temperature of the sheet surface temperature, a desired molding processing sheet or a molding processing material sheet that can be pulverized or cut can be obtained. be able to. Further, since the starch resin sheet is formed into a sheet by a rolling roll, the thickness of the starch resin sheet becomes uniform, and uniform pellets can be obtained. In addition, by forming a smooth skin layer on the front and back surfaces of the sheet by the action of a rolling roll, it can be used to produce a product capable of reducing water absorption after pelletization.

Hereinafter, the starch / resin composite intermediate particles of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

(Embodiment)
The raw materials used and the sample preparation method in Examples and Comparative Examples for producing the starch / resin composite intermediate granules and the starch / resin composite molding processed material of the present invention are as follows.
(Manufacture of starch / resin composite intermediate particles)
The raw materials blended to form the starch / resin composite intermediate granules and the starch / resin composite molding processing material of the present invention are as follows.

Starch: Cornstarch 50-70% by weight
Low melting point additives: Glycerin fatty acid ester, glycerin monostearate 0.1 to 10.0% by weight
Melting point additive: Metal stearate salt Zinc stearate, magnesium stearate 1.0 to 15% by weight
Thermoplastic resin: Polypropylene pellets 20-40% by weight
Each of the above raw materials was used according to the blending ratio in Table 1.

(1) Heating and stirring 1
The high temperature stirrer is set at 110 to 160 ° C. and the rotation speed is 5 to 50 Hz, and 50 to 70% by weight of cornstarch is blended as starch and 0.1 to 10.0% by weight of glycerin monostearate is blended as a low melting point additive. Is heated, stirred and mixed. The starch is melted by heating and stirring at a temperature equal to or higher than the melting point of glycerin monostearate, and the melted glycerin monostearate is entangled with cornstarch to obtain starch containing glycerin monostearate.

(2) Heating and stirring 2
In order to use the dried corn starch as a starch / resin composite material after mixing thoroughly in a high-temperature stirrer, 20.0 to 40.0% by weight of polypropylene and zinc stearate, which is a metal stearate salt as a refractory additive, are used. 5 to 5.0% by weight, 0.5 to 10% by weight of magnesium stearate, and other necessary additives such as white pigment and compatibilizer are added, and the temperature is raised to 110 to 160 ° C. with stirring. , The stearic acid metal soap is melted and mixed and stirred until a mixture of a fluid starch / resin composite material is formed.

(3) Cooling and Stirring Next, in order to form a starch / resin composite intermediate granule, a mixture of a fluid starch / resin composite material is formed, and then the mixture is discharged from a high temperature stirrer, transferred to a cooling stirrer, and transferred to 110 to 10 A mixture of a starch / resin composite material at 160 ° C. is cooled and stirred at a rotation speed of 5 to 40 Hz while being cooled to 60 to 100 ° C., and the temperature is lowered. A temperature above the melting point of the low melting point additive glycerin monostearate until the formation of the starch-resin composite intermediate granules coated with the glycerin monostearate attached to the powder or granular material containing the starch is confirmed. Cool and stir with.

(4) Discharge to the stock tank After it is confirmed that the starch / resin composite intermediate particles are formed by cooling and stirring, a low melting point is added to prevent the starch / resin composite intermediate particles from being destroyed and the powder from peeling off. While maintaining a temperature equal to or higher than the melting temperature of the glycerin monostearate of the agent, the starch / resin composite intermediate particles are immediately discharged into a stock tank arranged in the continuous production process and stored as an intermediate raw material.
In the composite intermediate particles to be stored, the coating layer of the powder or granular material containing the core portion of the thermoplastic resin and starch containing at least the low melting point additive glycerin monostearate is the high melting point additive zinc stearate and magnesium. It is formed as a stable starch-resin composite intermediate granule that is attached by resolidification and is in a tightly bound state without dropping or peeling of the powder or granular material.

(Evaluation of starch / resin composite intermediate particles)
The method for evaluating the starch / resin composite intermediate granules of the present invention was carried out as follows. As the intermediate raw material, the presence or absence of powder falling off at the time of discharging the composite intermediate granules and the formation ratio of the granules whose surface was coated with starch with the thermoplastic resin as the core were observed to evaluate the morphological stability.
Presence or absence of powder falling: Almost no powder falling 〇, powder falling occurs ×,
Further, using the obtained starch / resin composite intermediate granules as a raw material, a manufactured starch / resin composite molding material is manufactured, and the specific gravity and tensile elongation of the manufactured starch / resin composite molding material and the degree of variation thereof are determined. Intermediate granules were evaluated.

(Manufacturing of starch / resin composite molding processing material)
A twin-screw kneaded plasticized uniaxial extruder was used to evaluate the starch-resin composite intermediate granules, and a starch-resin composite molding material was produced as follows.

(Kneading of starch / resin composite intermediate particles)
The starch composite intermediate particles are put into a twin-screw kneading plasticizer from a stock tank, and the cylinder temperature is set to 120 to 190 ° C. and the resin pressure is set to 1 to 4 MPa for kneading.

(Molding of starch / resin composite molding processing material)
In order to produce a starch / resin composite molding material, the polypropylene / resin composite molding material prepared by kneading and plasticizing in the twin-screw extruder of the first stage is set to the set temperature of the heating zone and the polypropylene melting temperature. It was supplied to the second-stage uniaxial extruder set at 160 to 210 ° C. and a resin pressure of 3 to 20 MPa to extrude a starch / resin composite molten polypropylene.

(Creation of starch / resin composite molding processing material)
The following post-treatment was carried out in order to evaluate the influence on the moldability and workability of the molding material formed from the intermediate particles of the present invention.
The evaluation method was as follows.

(Creating a test sheet)
In order to manufacture the starch / molten polypropylene composite molding process material as a sheet, extrude it into a sheet using a T-die extruder, set the temperature of the take-up roll to 40 to 60 ° C, and set the temperature to a predetermined thickness. The sheet formed to 0.7 mm was cooled, taken up, and wound on a paper tube.
Further, if necessary, a calendar rolling process may be performed with three cooling rolls to control the thickness of the sheet, or a skin layer may be formed on the surface of the sheet to produce a glossy sheet.
Further, in order to utilize the starch / resin composite molding processed material produced by extrusion molding as a raw material for various molding processing methods, a molded sheet having a thickness control or a surface layer was cut into diced shapes in order to pelletize.

A sheet piece (2 x 20 cm) was sampled and extracted from 10 locations per 100 m of the length of the molded starch / resin composite molding processing material raw fabric sheet.
(A) Regarding the specific gravity of the material, the sampling sheet piece is measured three times according to JIS K7112, an average value is obtained, and the average value is used as the measured value. The sheet pieces having different positions in the longitudinal direction are measured in the same manner, and the average value is calculated and used as the measured value at each position. The average value of each measured value of the raw material sheet was obtained, the fluctuation value of each measured value and the average value was obtained, and the variation was confirmed by the fluctuation range of the measured value of the specific gravity of the raw material sheet.
(B) Regarding the tensile elongation of the material, the sampling sheet piece is pulled according to JIS K 7161, the maximum tensile elongation before the creep phenomenon occurs is measured three times, the average value is calculated, and the average value is obtained. Is the measured value. The sheet pieces having different positions in the longitudinal direction are measured in the same manner, and the average value is calculated and used as the measured value at each position. The average value of each measured value of the raw fabric sheet of the material was obtained, the fluctuation value of each measured value and the average value was obtained, and the variation was confirmed by the fluctuation range of the measured value of the maximum tensile elongation of the raw fabric sheet.

(Test molding of container)
A sheet molded to confirm the moldability of the above sheet manufactured from a starch / resin composite molding processing material is used as a vacuum pressure air machine; FVS-500P type manufactured by Wakisaka Engineering Co., Ltd., and molding conditions: setting. After heating to a temperature of 450 ° C., the product was formed into a conical cup by a vacuum pressure air blower.

(Examples 1 to 7 and Comparative Examples 1 to 5)
As a raw material for a starch / resin composite molding processing material, a raw material is prepared according to the component composition of the production conditions as shown in the above embodiment, and the process is processed according to the production conditions of each production process. The starch / resin composite intermediate granules and the starch / resin composite molding processing material of Examples 1 to 5 were produced.

The produced starch / resin composite molding processed material is used as an evaluation sample according to the above sample preparation, and the starch / resin composite intermediate granules and the starch / resin composite molding processed material are produced, and the above-mentioned evaluation is performed using the prepared test sample. The physical properties of the material and the molding processability of the starch / resin composite intermediate granules and the starch / resin composite molding process material through molding according to the items, and the uniformity and homogeneity of the material important as the composite molding material, are stretched. The variation in specific gravity was evaluated.

Regarding the moldability of the sheet, it was confirmed whether the sheet could be molded by the above T-die uniaxial extruder (manufactured by LAB TECH Engineering Co., Ltd.). It was confirmed whether the molded sheet could be vacuum-compressed air-formed with an FVS-500P mold manufactured by Wakisaka Engineering Co., Ltd. so as to form a conical cup, and a deep-throttled container could be formed. We also evaluated whether the container could be molded with an injection molding machine.
Table 1 shows the composition of the raw materials and the test results for the produced composite intermediate particles and composite molding processed materials.

As shown in Table 1, in Examples 1 to 3, intermediate granules having a stable composition with morphological stability can be produced, and the starch / resin composite molding processed material produced by melt-extruding the intermediate particles as a raw material is , A composite molding material having an average tensile elongation measured by the above test method in the range of 36 to 160% and an average specific gravity in the range of 1.08 to 1.21 in one rod of the material of each example. The variation of the measured value of the tensile elongation for each has a fluctuation range of 34 to 39%, 73 to 77%, and 148 to 164%, respectively, in Examples 1 to 3, respectively, and even if the fluctuation range is large, ± Within 7%, the measured value of specific gravity is ± 0, which is stable and has excellent physical properties with little variation.
Regarding the molding processability by each molding processing method using the manufactured material, it was possible to produce a material that can be made into a sheet, can be molded into a container, and can be deep-drawn.

On the other hand, as shown in the comparative example, the starch / resin composite molded material that does not pass through the composite intermediate particles of the present invention can be formed into a sheet, but cannot be molded, or the material is not slippery and cannot be extruded, or is composite. The intermediate granules are too large to be made into a sheet, or the composite molded material produced by melt extrusion as a molding material has an average tensile elongation of 15% in one rod, and the measured value fluctuates. The tensile elongation has a fluctuation range of 7 to 21%, a fluctuation range of ± 50%, an average specific gravity of 1.24, and a measured value of 1.19 to 1.26. The mechanical properties such as are deteriorated or the mechanical properties are poor, or the specific gravity varies and is not stable. Further, in terms of moldability, the material could be formed into a sheet, but the surface of the sheet was sticky, or the material was powdery or lumpy and could not be molded. Moreover, the container could not be molded.

It was confirmed that when the starch / resin composite molded material produced by using the starch / resin composite intermediate granules of the present invention as a raw material, excellent physical properties, properties and moldability can be obtained, and the starch / resin composite molding material can be obtained. It was clarified that using the resin composite intermediate granules as a raw material is superior as a starch / resin composite molding processing material.

In Examples and Comparative Examples, the composition of the starch / resin composite molded material having the composition as shown in Table 1 was used. Of the blending composition of the starch / resin composite molding processing material used in Example 2, in Examples 4 and 5, the blending amount of mainly monoglyceride was significantly changed to 0.1% by weight; 10.0% by weight. In Examples 6 and 7, the blending amounts of zinc stearate and magnesium were significantly changed to 0.5, 0.5; 5.0 and 10.0% by weight, respectively, to granulate each additive. The effect on moldability was confirmed.

Pellets and sheets are produced from the produced starch / resin composite molding material by the same method as in Example 1, and the sheets are formed into a container having the same dimensions as in Example 1 by vacuum pressure molding, and Example 1 is performed. The molding processability was evaluated in the same manner as in the above. In addition, the tensile elongation and specific gravity were measured and evaluated according to the measuring method described above. Further, as a comparative example, the blending amount of starch and polypropylene, the blending amount of monoglyceride, and the blending amount of metal stearate soap are changed, respectively, and the molded product formed as shown in Table 1 is evaluated and added. The range of amounts was expanded, compositions were prepared, and similar measurements were made for evaluation.
The results are shown in Table 1.

As can be seen by comparing Examples and Comparative Examples, granulation may or may not be possible depending on the amount of the low melting point additive monoglyceride, the high melting point additive zinc stearate, and magnesium stearate. I understand. Furthermore, it can be seen that depending on the content, there are cases where sheet formation and molding processability of the container cannot be expected and cases where it can be achieved.

According to Examples and Comparative Examples, the composite molding process material using the starch / resin composite intermediate granules of the present invention as a raw material is capable of sheet molding by a T-die extruder and has superior molding processability. As the raw material of the starch / resin composite intermediate granules of the present invention, the starch / resin composite molded material having excellent physical properties can be obtained. Because intermediates cannot be formed, specific gravity is not stable, starch flutters, or there is no slipperiness during extrusion with conventional methods or starch / resin composite molded materials using extreme component compositions as raw materials, even if they have the same component system. It was confirmed that the molding processability was hindered, such as excessive pressure being applied and the sheet could not be formed, the bleeding becoming extremely sticky when the sheet was formed, the intermediates sticking to each other, the granules becoming too large, and the molding machine could not be supplied. It was confirmed that the method for forming the intermediate granules of the present invention and producing the starch / resin composite molding processed material is excellent.

The starch-resin composite intermediate granules obtained by the present invention are derived from a biomass material that can replace conventional petroleum-based plastics, and are manufactured by an extruder, a sheet by a T-die extruder, and a film by an inflation molding machine. Manufactures starch / resin composite molding materials that can be used in various molding processing technologies such as manufacturing of sheets, manufacturing of sheets by calendar molding machines, manufacturing of molded products by injection molding machines, and molding processing machines, and are suitable for various molding methods. It is useful for.

Claims (8)

A starch-resin composite intermediate granule formed from a composite material composition containing starch, a low melting point additive, a high melting point additive having a higher melting point than the low melting point additive, and a granular thermoplastic resin. A granular material thermoplastic resin is used as a core portion, and a coating layer of a powder or granular material containing starch containing at least a low melting point additive, which is attached to the surface of the core portion of the granular material by a high melting point additive, is provided.
The starch / resin composite intermediate granules contain 50% by weight or more of starch, 20% by weight or more and less than 50% by weight of granular materials of thermoplastic resin, 0.1 to 10% by weight of low melting point additive component, and addition of high melting point. Contains 1.0 to 15% by weight of the agent component
The low melting point additive is a glycerin fatty acid ester, and the high melting point additive is a metal stearic acid salt.
Starch / resin composite intermediate granules for producing starch / resin composite molding processing materials. The starch / resin composite intermediate granule according to claim 1, wherein the low melting point additive is at least one selected from the group of monoglyceride, diglyceride, triglyceride, and polyglycerin fatty acid ester. The starch / resin composite intermediate granule according to claim 1 or 2, wherein the low melting point additive is glycerin monostearate. Refractory additives, magnesium stearate, zinc stearate, calcium stearate, at least one selected from the group of aluminum stearate, starch-resin composite intermediate according to any one of claims 1 to 3 Granules. Claim that further comprises at least one additive selected from the group of compatibilizers, colorants, excipients, disintegrants, modifiers, wetting agents, antioxidants, UV absorbers, flow promoters. The starch / resin composite intermediate granule according to any one of 1 to 4. The invention according to any one of claims 1 to 5, wherein the thermoplastic resin is at least one resin selected from the group of polyolefin-based resin, polystyrene-based resin, ABS resin, polyester-based resin, and polyamide-based resin. Polystyrene / resin composite intermediate granules. The starch / resin according to any one of claims 1 to 6, wherein the thermoplastic resin is at least one selected from the group of polyethylene, polypropylene, polystyrene, or styrene-acrylic acid-butylene copolymer resin. Composite intermediate granules. Injection molding, blow molding, extrusion molding, cast film molding, inflation molding, compression using the starch / resin composite intermediate granules according to any one of claims 1 to 7 as a raw material and containing or not containing a foaming agent. Precipitate / resin composite molding material pellets or sheets suitable for molding, calendar molding, transfer molding, rotary molding, or vacuum-molded products or vacuum-pressurized products, injection-molded products, blow-molded products containing or not containing a foaming agent. , Extrusion molded product, cast film molded product, inflation molded product, compression molded product, calendar molded product or transfer molded product.

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