JP6901855B2 - Method for producing starch / resin composite intermediate granules - Google Patents

Description

The present invention relates to a method for producing a starch / resin composite intermediate granule, and more specifically, it is used in 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 method for producing a starch / resin composite intermediate granule for producing a starch / resin composite molding processing material containing starch as a main component, which biodecomposes or disintegrates in a short period of time when it is disposed of. In particular, a starch / resin composite molding processing material having physical properties and molding processability suitable for various plastic molding methods such as vacuum molding, extrusion molding, injection molding (injection molding), inflation molding, and blow molding (injection molding). The present invention relates to a method for producing a starch / resin composite intermediate granule for producing the above.

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 to solve 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, has been 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.

A typical example of a biomass material is starch. 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 starch / resin composite molding that 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% by weight or more of starch. Provided is a method for producing a starch / resin composite intermediate granule, which is a raw material or composition capable of stably and efficiently producing a processed material. Moreover, the present invention provides a method for producing a starch / resin composite intermediate granule, which is excellent in morphological stability and workability, is stable, and can be stocked at low cost.

More specifically, the present invention is a starch-resin composite intermediate in which a granular material of a thermoplastic resin is used as a core portion and a coating layer of a powder or granular material containing starch containing a low melting point additive is provided on the surface of the core portion. It is an object of the present invention to provide a method capable of producing granules easily, easily, stably and efficiently.

As a result of diligent studies to solve the above problems, the present inventors have excellent variations in molding processability and workability in various molding processing methods as the method for producing the starch / resin composite intermediate granules of the present invention. Starch / resin composite with less starch / resin composite Starch / resin composite containing starch, thermoplastic resin, low melting point additive and high melting point additive by heating and stirring in a high temperature stirrer and mixing in order to manufacture the processed material inexpensively and stably. Material formation and cooling of starch / resin composite material Stirring and melting while cooling to a predetermined temperature lower than the melting temperature of the high melting point additive and higher than the melting temperature of the low melting point additive in a stirrer. This is a method capable of easily and easily forming and producing a starch / resin composite intermediate granule that can be stocked by resolidification of the additive component. Moreover, it is a method for producing a starch / resin composite intermediate granule that can be stocked in the form of an intermediate granule as a raw material for a starch / resin composite molding processing material.

More specifically, the present invention melts the low melting point additive by heating and stirring the raw material of the mixture containing starch and the low melting point additive such as glycerin-based ester, and melts the low melting point additive with the starch. Additives are mixed, entwined with starch, adhered and contained in starch. Then, at least a thermoplastic resin granule 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 fluid starch / resin composite material, the high melting point additive in a molten state is cooled and stirred in a cooling stirrer to a predetermined temperature higher than the melting temperature of at least one low melting point additive. Is resolidified to form a granular material of a thermoplastic resin as a core portion, and a starch / resin composite intermediate granule having a starch granule containing at least a low melting point additive is formed on the surface of the core portion. Further, it is a manufacturing method including immediately discharging the formed starch / resin composite intermediate particles from a cooling stirrer, dropping them into a stock tank, and storing them.

Moreover, the method for producing the starch / resin composite intermediate granules of the present invention uses the method for producing the starch / resin composite intermediate granules as a raw material supply step and combines it with the method for producing the starch / resin composite molding processed material to produce starch. -A production method capable of stably producing a starch-resin composite intermediate granule, which is an intermediate raw material, capable of efficiently producing a resin composite molding processing material has been established, and the above object has been achieved.

Then, the production method of the present invention can stably stock the produced starch / resin composite intermediate granules as a raw material for producing a starch / resin composite molding processed material, thereby enabling stable supply. It is a starch / resin composite molding processing material that is uniform and uniform even if it contains starch at a high concentration, and is stable and has little variation, which could not be obtained in the past, and is excellent in molding processing in various molding processing methods. A method for continuously and consistently producing a starch / resin composite molding processed material having properties, excellent in morphological stability, flow stability, and workability, at low cost, and starch / resin as an intermediate raw material. A method for producing a composite intermediate granule can be provided, and the above object has been achieved.

In the method for producing composite intermediate particles of the present invention, a fluid starch / resin composite material formed by a high-temperature stirrer is resolidified in a cooling stirrer to form a fatty acid on the surface of the granular material of the thermoplastic resin. Resolidification of high melting point additives such as metal salts and the presence of starch that is dispersed, adhered and contained on the surface of the starch so as to wet the low melting point additive, so that the thermoplastic resin is used as the core part and at least the surface thereof is contained. It is possible to obtain a product in the form of a starch / resin composite intermediate particle having a structure coated with a coating layer of a powder or granular material containing starch.

According to the method of the present invention, a starch-resin composite material in which a biomass, for example, industrial corn (dent corn) starch is contained in an amount of 50% by weight or more in the form of granules of a thermoplastic resin, or a dispersant. , Even if it is a composite material of raw materials having different shapes and morphologies, including additives such as a compatibilizer, it is possible to produce a starch-resin composite intermediate granule having excellent morphological stability with less powder falling off.

By producing a starch-resin composite intermediate granule as in the present invention and supplying it as a raw material, it is possible to stably supply the raw material, which has been difficult in the past, to quantify the material in the molding process, and to make the sheet-like material uniform. It is possible to form a starch / resin composite molding process material that can be homogenized and homogenized and has little variation.

In the method for producing a starch-resin composite intermediate particle of the present invention, even if 50% by weight or more of starch is blended, the formability and mechanical properties of the material to be formed are biased to bring the interface between the starch and the thermoplastic tree closer to each other. It is possible to obtain a composite intermediate particle with morphological stability by devising not only the compounding technology of the agent and the compounding of the material but also the processing conditions. Further, the generation of starch odor and the generation of fading can be suppressed.

In the method for producing a starch / resin composite intermediate granule of the present invention, the starch / resin composite intermediate granule can be used as a raw material to form a more uniform and homogeneous composite granule material, and the produced starch / resin composite molding can be formed. Since the material can be melted more uniformly and uniformly, it has excellent molding processability suitable for molding methods such as extrusion molding, T-die extrusion molding, vacuum molding, injection molding, inflation molding, and calendar molding. It is possible to manufacture a starch / resin composite molding material that is compatible, has less starch odor, and suppresses the occurrence of fading.

According to the method for producing a starch / resin composite intermediate granule of the present invention, a consistent and continuous production line from compounding to sheet extrusion can be assembled, stable commercialization can be realized, space saving and improvement of production efficiency can be achieved. Can be planned. further,
The starch / resin composite molding process material produced by the method for producing a composite intermediate granule of the present invention suppresses deterioration of mechanical properties, enables deep drawing of thin and deep containers, and saves petroleum resources. , Reduction of carbon dioxide generated during incineration, Paper texture because the main raw material is starch, but excellent design and water resistance due to thermoplasticity can be manufactured.
In addition, when used as a packaging material, it has sufficient product strength when used, but it can be crushed with a light force after use, which can contribute to reducing the volume of dust.

Therefore, the present invention is a more suitable environment-friendly material as a substitute for petroleum-based plastic as the starch-resin composite material of the present invention, and is used for various food containers, packaging materials, cushioning materials, daily necessities, and agriculture. It can be fully applied to 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

The method for producing the starch-resin composite intermediate granules of the present invention described above will be described in more detail below.

(Manufacture of starch / resin composite intermediate particles)
The present invention is a method for producing a starch / resin composite intermediate granule, in which the starch and the low melting point additive are heated and stirred to melt the low melting point additive, mixed with the starch, and the low melting point is added to the starch. The agent is entangled and adhered to form a starch containing a low melting point additive. Then, the composite raw material containing the granular material of the thermoplastic resin 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 granular material of the thermoplastic resin 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 to resolidify the high melting point additive in a molten state, and the granular material of the thermoplastic resin is used as the core part, and the low melting point additive is applied to the surface thereof. This is a method for producing a starch-resin composite intermediate granule having a coating layer of a powder or granular material containing starch.

Further, the method for producing a starch / resin composite intermediate granule according to the present invention provides a starch / resin composite molding processed material having excellent uniformity and homogeneity with little variation even if the starch is contained in an amount of 50% by weight or more. It is a method for producing starch / resin composite intermediate grains that are indispensable for obtaining, and can be incorporated so that it can be supplied as a raw material in the manufacturing process of starch / resin composite molding processing materials, or independent starch / resin composite intermediate grains. It can also be used as a method for manufacturing the body.

The starch / resin composite intermediate granules produced by the production method of the present invention can be easily and surely produced in the process of producing the starch / resin composite molding processed material, or can be separately produced and supplied as a raw material. It can be used in the process of manufacturing a molding material.

The manufacturing process of the present invention is incorporated into the manufacturing process of the starch / resin composite molding material so as to be supplied as a raw material, and the molding material can be stably and continuously manufactured.
In the production method of the present invention, a starch / resin composite molded material having a uniform and uniform shape, excellent molding processability, and excellent workability is finally stably and continuously produced from a composite material containing various raw materials. It enables consistent manufacturing.

(starch)
In the production of starch / resin composite intermediate granules capable of obtaining stable quality starch / resin composite intermediate granules without using special means and equipment according to the present invention, starch is contained in an amount of 50% by weight or more. However, in a method capable of producing a starch / resin composite molding processed material having excellent uniformity and homogeneity with little variation, the starch used as a biomass material for forming a starch / resin composite intermediate granule is inexpensive. Available raw starch can be used, and examples thereof include corn starch, bean starch, tapioca starch, potato starch, wheat starch, rice starch, fox mackerel starch, hissi starch, hass starch, sago starch, warabi starch, and waste starch. be able to.

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 process 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 further lowering the biodegradability.
The thermoplastic resin used in the present invention includes polyolefin-based resins such as polyethylene and polypropylene, polystyrene, polyamide, polyester, ethylene / vinyl acetate copolymers, and petroleum-based plastics such as alkylene / acrylate or methacrylate copolymers. 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 is less than 20% by weight, the amount of starch having a small specific gravity is large as a starch / resin composite molding material, and it is difficult to homogenize the biomass molding material. It becomes difficult to obtain. Moreover, it is necessary to increase the amount of the additive. As a result, the mechanical properties are remarkably deteriorated, uneven thickness, tearing and the like occur during molding, and it becomes difficult to mold a thin material and a deep drawing of a deep material, and it becomes difficult to obtain a texture and a molding process.

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 processing material has physical properties as a plastic molding material. Although it has strong properties and can be molded, it is difficult to reduce the volume, the contribution to the reduction of greenhouse gas emissions is reduced, and it is difficult to obtain a starch / resin composite molding process material as a biomass raw material. Moreover, since there are many fillers, the physical characteristics of the molded material and the uniformity and homogeneity of the composite material fluctuate greatly, and a stable material cannot be obtained.

When a molding processed material is produced from a material having the same composition of each component of the raw material without forming a starch / resin composite intermediate granule by the production method of the present invention, the physical properties of the molding material, the uniformity as a composite material, and the homogeneity Fluctuations are large, making it difficult to obtain stable materials.

Examples of the biodegradable resin forming the core portion 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 Examples thereof include biodegradable resins such as hydroxybutyrate / variate copolymers.

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 of the major axis is exceeded or the size is small, the balance of the amount of adhered granules is poor, and as a composite material of starch and thermoplastic resin, the uniformity and homogeneity are inferior, and further. Is inferior in dispersibility in the molded product. 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 and the thermoplastic resin and adheres to the starch. Further cool and agitate, at least to allow the starch and the thermoplastic resin granules to retain the properties of the fluid starch-resin composite material, as well as to have an affinity for and adhere to the thermoplastic resin. When the refractory additive is resolidified, it is necessary to add an additive that can play an adhesive role so that the morphology of the starch-resin composite intermediate granules can be stably formed.

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 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".

As low melting point additives, monoglyceride ( for example, glycerin monostearate, etc. ), diglyceride, triglyceride, acetylated monoglyceride, organic acid monoglyceride, medium chain fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid. Examples include esters, special fatty acid esters, and higher alcohol fatty acid esters. 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. Moreover, 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 above-mentioned low melting point additive, 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 a coating layer of a powder or granular material containing starch and forming a starch-resin composite intermediate particle.

The high melting point additive is a composite intermediate granule without the starch peeling or falling from the starch / resin composite intermediate granules or the intermediate granules disintegrating until it is used for producing a molding process material. It is an additive that functions to retain the form of.
For the high melting point additive, it is necessary to consider the type of thermoplastic resin and the affinity with the additive, but the starch / resin composite intermediate granules are used as the raw material for uniform and uniform starch / resin composite molding processing in the processing machine. The composite raw material is dispersed to make it a material, and when melt-kneaded as a starch / resin composite material, it is uniformly dispersed, yet it reduces friction with the processing machine, enhances fluidity in the processing machine, and enhances external slipperiness. 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 starch-resin composite intermediate particles, improving the dispersibility during melt-kneading and imparting slipperiness is a fatty acid metal salt, a hydrocarbon type, or a higher alcohol. Systems, aliphatic amides, fatty acid esters, etc. 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 type 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 additives having a low melting point and a high melting point as described above, 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 form of the starch-resin composite intermediate granule of the present invention is automatically formed by the above. 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, it is possible to obtain a product having the necessary physical properties and molding processability.

(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.

In the present invention, the shape and size of the starch-resin composite intermediate granules can be appropriately determined in consideration of the shape and particle size 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.

The method for producing the starch / resin composite intermediate granules of the present invention is such that the starch / resin composite intermediate granules do not lose their shape until they are melt-kneaded in order to produce the starch / resin composite molding processed material which is a product. , And has morphological stability to which starch is attached with adhesive strength to the extent that starch does not peel off, and is formed so that a stable state can be maintained 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 processing 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 is used as a raw material, or a starch / resin composite intermediate granules. Is assembled as a method for continuously and consistently manufacturing up to the product of starch / resin composite molding processing material, which is a raw material, and is manufactured by using the starch / resin composite molding processing material continuous integrated manufacturing equipment shown in Fig. 1. Will be done.

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 particles of the present invention, the production apparatus consisting of each apparatus shown in the starch / resin composite intermediate particle 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 a low melting point additive melted with starch, 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 / high melting point additive, and the granulated starch / resin composite intermediate granules. Manufactured using a manufacturing device including a stock tank and a supply device 3 that can be used as a supply buffer for composite intermediate particles used as raw materials so that the body can be stocked and a starch / resin composite molding processed material can be continuously manufactured. 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 stored starch / resin composite intermediate granules are supplied as a raw material. 3. The twin-screw extruder 4 that heat-kneads the raw materials to make a fluid starch / resin composite material and extrudes it, and the thermoplastic resin part that has been kneaded and is in a molten state to further raise the cylinder temperature to further raise the cylinder temperature of the molten thermoplastic resin starch. It can be manufactured by the starch / resin composite molding processing material manufacturing apparatus 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 apparatus can be manufactured. A continuous integrated manufacturing device is formed by arranging the intermediate grains in succession to the device section A for manufacturing the intermediate grains, or the starch / resin composite molding processing material manufacturing device section B is used as a single manufacturing device and the starch / resin composite intermediate grains are used as raw materials. It is also possible to prepare the body separately and use it as a device for manufacturing in batches.

The starch / resin composite molding material continuous integrated manufacturing apparatus used in the present invention is a roller rolling apparatus capable of further extruding into a sheet shape and controlling the thickness of the sheet and the formation of a surface layer by calendar forming the sheet. 6. Or, 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 production of the starch-resin composite intermediate granules of the present invention, first, at least one of the starch and the low melting point additive is lower than the melting temperature of the thermoplastic resin in a high temperature stirrer, and is equal to or higher than the melting temperature of the low melting point additive. The mixture is mixed with heating and stirring at the same temperature as above, and the heating and stirring is controlled so as to obtain a mixture in which the low melting point additive melted in the starch is attached.

After that, a high melting point 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 characteristics 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.

(Heat stirring process with a high temperature stirrer)
(1) Heat-stirring treatment of starch and low-melting point additive In the heat-stirring treatment of the present invention, the starch and low-melting-melting additive are heated and stirred in a high-temperature stirrer to heat and mix the starch and the melted low-melting point additive. It is to be done as follows.

First, starch and a low melting point additive such as a glycerin-based 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 than 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 a low melting point additive melted with a high temperature stirrer, a granular material of a thermoplastic resin and a high melting point additive such as at least one kind of 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 and stirring machine)
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 fluidized 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 granular material of the thermoplastic resin via at least the refractory additive that resolidifies, the granular material of the thermoplastic resin becomes 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.

The method for producing a composite intermediate particle of the present invention heats and mixes raw materials of hard-to-mix component materials having different properties and shapes of a starch / resin composite intermediate particle with good handleability that enables stable supply of raw materials to the manufacturing process. After that, the fluid composite material is cooled with stirring, and the fluid composite material solidifies when the temperature of the fluid composite material decreases and the melted additive component becomes lower than the melt temperature. Is formed, which is a manufacturing method that can be easily granulated by a simple operation of heating and mixing the raw materials and then cooling and stirring.

Conventionally, in the production of molding materials, component raw materials having different properties and shapes have been individually or batch-supplied to the manufacturing process, and the raw materials have a composite form called composite intermediate particles that are easy to handle. It enables the material to be put into the manufacturing process, and enables stable supply and quantification of the raw material in the manufacturing of the starch / resin composite molding processed material.

In the granulation process by cooling and stirring operation, the temperature, rotation speed, stirring time, etc. are controlled, and the additive component is resolidified to form a coating layer of powder or granular material containing starch on the surface of the granular material of the thermoplastic resin. It is possible to granulate by cooling and stirring at an optimum temperature while confirming the state of being formed, and to maintain the shape and shape of the formed granules and take them out.

In the present invention, the starch / resin composite intermediate granules are in a temperature range in which the components of the low melting point additive do not solidify while observing the appearance of the granulated granules and confirming the state of good appearance. Then, it is discharged from the cooling stirrer, dropped into the stock tank, taken out as an intermediate raw material in the form of a starch / resin composite intermediate particle, and stocked. As a result, it is possible to obtain a starch / resin composite intermediate granule having excellent morphological stability with almost no powder falling off.
Then, by using the starch / resin composite intermediate granules as a raw material, a high-quality starch / resin composite molding processed material can be produced.

In the process of manufacturing the composite intermediate particles, the formation status of the composite intermediate particles is controlled by controlling the temperature, the number of rotations, the stirring time, etc., and the components of the additive in the molten state are resolidified to resolidify the surface of the granules of the thermoplastic resin. By observing and confirming the state in which a coating layer of powder or granular material containing starch is formed, the morphology and shape of the formed granular material are maintained, and starch with excellent morphological stability with almost no powder falling off. -A resin composite intermediate particle can be obtained. When the amount of the low melting point additive and / or 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 was not possible to extrude the starch as it was in the form of powder or the starch was shed from the coating layer, resulting in a mixture of the composite intermediate particles and the 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.

The method for producing the starch / resin composite intermediate granules by this heating / cooling / stirring step can also be produced in a batch system. On the other hand, in the production of the starch / resin composite molding processed material, the component material can be continuously kneaded and extruded as a raw material in the form of a composite intermediate granule. , The process of discharging the composite intermediate granules to the stock tank serves as a buffer for incorporating the composite intermediate granule manufacturing process into the manufacturing method of the starch / resin composite molding processing material, and the starch / resin composite molding processing material is continuously and consistently produced. Makes it possible to manufacture.

According to the present invention, a starch / resin composite intermediate granule having good morphological stability without powder falling is produced by using a starch / resin composite intermediate granule produced by a simple and few operations as a raw material. It is possible to obtain a starch / resin composite molding processing material with little variation in quality. Then, it can be used as an intermediate raw material for that purpose, and it becomes possible to stably and inexpensively prepare a uniform and homogeneous starch / resin composite molding processed material, which can be a stable production method of 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. By incorporating it, it can be used as a production line that enables stocking as an intermediate raw material for starch / resin composite molding processing materials, 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 starch / resin composite intermediate particles as raw materials, and it is possible to stably supply raw materials with different properties and shapes, and continuous production of starch / resin composite molding processing materials with little variation is possible. It can be used as a manufacturing method that enables it.

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. By supplying, controlling the number of revolutions, stirring time, temperature, etc. in the same manner as in normal plastic molding, and heating and kneading, it becomes possible to uniformly knead and mix the starch and the thermoplastic resin.

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. Set to a temperature higher than the melting temperature of, and heat and knead. As a result, the starch / resin composite intermediate granules are used as a preliminary step for forming a fluid starch / resin composite molding processed material, and the stable material is quantitatively fed and the material is sufficiently agitated 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, in the method of the present invention, the produced starch / resin composite intermediate granules are sufficiently heated and kneaded as described above, and then a fluid starch / resin composite material is uniaxially extruded in the same manner as in the melt extrusion step of plastics. By setting the temperature to 150 to 220 ° C, which is higher than the melting temperature of the thermoplastic resin, and appropriately setting the extrusion pressure, the thermoplastic resin can be melt-extruded in a stable state, so that the starch is uniform, uniform, and has little variation. It can be incorporated and used as an improved manufacturing method for manufacturing resin composite molded materials.

In the present invention, in extrusion, a molded product by an extruder, a sheet by a T-die extruder, a film by an inflation molding machine, a sheet by a calendar molding machine, 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, in the method for producing a starch / resin composite intermediate granule of the present invention, a T-die is used to set the temperature at 150 to 220 ° C., and the starch / resin composite molding material is extruded as a sheet-like material. Can be used to obtain.

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. It can be used in the production of raw materials for composite materials.

For the starch / resin composite molding process 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 less, and the sheet formed to a predetermined thickness is cooled, taken up, and wound up. The raw fabric roll is made into a raw fabric roll, or the raw fabric roll, which is a material for composite molding of starch and resin of a sheet, is passed between three rolling rolls, which are cooled by giving the roll a cooling function and cooling the surface. It can also be a molded material sheet having a surface skin layer whose thickness is controlled by a roll. 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 crushed 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 a homogeneous pellet can be produced. 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 for producing a product capable of reducing water absorption after pelletization.

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

(Embodiment)
(Examples 1 to 7)
The raw materials used and the sample preparation in the 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
20-40% by weight of polypropylene and 0.5-5.0% by weight of zinc stearate, which is a metal stearate salt as a refractory additive, in order to use corn starch sufficiently mixed in a high-temperature stirrer as a starch / resin composite material. , 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 to obtain the above-mentioned metal soap of stearic acid. Is melted and mixed and stirred until a mixture of fluid starch / resin composite material is formed.

(3) Cooling Stirring Next, in order to form a starch / resin composite intermediate granule, a mixture of a fluid starch / resin composite material is formed, discharged from a high temperature stirrer, transferred to a cooling stirrer, and 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. The melting point of the low melting point additive glycerin monostearate until it is confirmed that the glycerin monostearate is attached to the mixture, and the powder or granular material containing the starch is attached to the mixture to form the coated starch / resin composite intermediate granules. Cool and stir at the above temperature.

(4) Discharge to the stock tank After it is confirmed that the starch / resin composite intermediate particles are formed by cooling and stirring, it is low to prevent the starch / resin composite intermediate particles from being destroyed, the powder from peeling off, and falling off. While maintaining a temperature equal to or higher than the melting temperature of the melting point additive glycerin monostearate, the starch / resin composite intermediate particles are immediately discharged to 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 stearic acid. It is formed as a stable starch-resin composite intermediate granule that is attached by resolidification of magnesium acid acid 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 / resin composite intermediate granules 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.

(Preparation of test samples for starch / resin composite molding materials)
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 obtain a glossy sheet.
Further, in order to utilize the starch / resin composite molding process material produced by extrusion molding as a raw material for various molding processes, a molded sheet having a thickness control or a surface layer was cut into a diced shape 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 process material is used as a vacuum pressure air machine; Wakisaka Engineering Co., Ltd., FVS-500P type, and molding conditions: setting. After heating to a temperature of 450 ° C., it was molded by a vacuum pressure air blower so as to form a conical cup.

(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 particles 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 processing material through molding according to the items, and the uniformity and homogeneity of the material which is important as the composite molding material, are stretched. The variation in specific gravity was evaluated.

Regarding the formability of the sheet, it was confirmed whether the sheet could be formed 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, Examples 1 to 3 are starch / resin composite molding processed materials produced by melt-extruding intermediate particles having a stable composition with morphological stability and using the intermediate particles as a raw material. Yes, it 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 in the measured values of tensile elongation for each example has fluctuation ranges of 34 to 39%, 73 to 77%, and 148 to 164%, respectively, in Examples 1 to 3, and even if the fluctuation range is large. Within ± 7%, the measured value of specific gravity is ± 0, which is unchanged 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 capable of forming a sheet and vacuum forming a container, and deep drawing.

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 a starch / resin composite molding processed material is produced using the starch / resin composite intermediate granules produced by the production method of the present invention as a raw material, those having excellent physical properties, properties and moldability can be produced. It was clarified that the production of the starch / resin composite intermediate granules is effective as a method for producing the 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. Further, the tensile elongation and the 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.

It can be seen that sheet molding by a T-die extruder is an effect of the invention, and the molding processability is hindered by an increase in the amount of the additive added.

According to Examples and Comparative Examples, it is possible to perform sheet molding by a T-die extruder or the like by supplying raw materials by the manufacturing method of the present invention to manufacture a composite molding processing material, and molding processing by various molding processing methods. It is possible and has an advantage in molding processability.

As the method for producing a starch / resin composite molding processed material using the starch / resin composite intermediate granules of the present invention as a raw material, a starch / resin composite molding processed material having excellent physical properties and the like can be obtained. As summarized in Table 1, intermediate granules cannot be formed, the specific gravity is not stable, and starch flies, even if the same component system is used in the conventional method or the method for producing a starch / resin composite molded material using an extreme component composition. When extruded, the pressure is too high to form a sheet due to lack of slipperiness, the bleeding becomes extremely sticky when the sheet is formed, or the intermediate particles stick to each other, the particles become too large, and cannot be supplied to the molding machine. It was confirmed that the processability was hindered, and it was confirmed that the method for forming the intermediate granules of the present invention and producing the starch / resin composite molded material was excellent.

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

Claims (9)

Starch, thermoplastic resin granules, and starch / resin composite material containing a low melting point additive and a high melting point additive in a molten state are cooled and stirred, and the thermoplastic resin granules are used as the core part on the surface of the core part. a step of forming a coating layer having a granular material containing a starch containing low melting point additive seen including,
The thermoplastic resin has a melting temperature higher than the melting point of the high melting point additive,
The low melting point additive melts at 60 to 100 ° C. to enhance internal slipperiness.
The high melting point additive has a melting point of 100 to 150 ° C., enhances external slipperiness, and has a higher melting point than the low melting point additive.
The starch / resin composite intermediate granules are 50% by weight or more of starch, 20% by weight or more and less than 50% by weight of thermoplastic granules, 0.1 to 10% by weight of low melting point additive, 1.0 to 15%. Containing% by weight high melting point additive,
A method for producing a starch / resin composite intermediate particle. (A) A step of heating, stirring and mixing starch and a low melting point additive to form a starch mixture containing a melted low melting point additive.
(B) Granules of thermoplastic resin and high melting point additive are added to the starch mixture, and the mixture is heated and stirred at a temperature equal to or lower than the melting temperature of the thermoplastic resin to mix, and the low melting point additive and the high melting point additive are in a molten state. The method for producing a starch / resin composite intermediate granule according to claim 1, further comprising a step of forming a fluid starch / resin composite material containing the mixture. The low melting point additive and starch are heated, stirred and mixed at the melting temperature of the low melting point additive or higher, the melting temperature of the high melting point additive or higher, and the melting temperature of the thermoplastic resin or lower, and the low melting point additive is attached and contained. The method for producing a starch / resin composite intermediate granule according to claim 2, which comprises a step of preparing a starch mixture. (C) The fluid starch / resin composite material containing the low melting point additive and the high melting point additive in a molten state is transferred to a cooling stirrer, cooled and stirred, cooled to below the melting temperature of the high melting point additive, and resolidified. The method for producing a starch / resin composite intermediate granule according to any one of claims 1 to 3, which comprises the step of making a starch / resin composite intermediate granule. (D) A step of discharging starch / resin composite intermediate particles formed at a temperature equal to or higher than the melting temperature of a low melting point additive from a cooling stirrer and stocking them at room temperature while cooling and stirring at a temperature equal to or higher than the melting temperature of the low melting point additive. The method for producing a starch / resin composite intermediate granule according to any one of claims 1 to 4, further comprising. The starch / resin composite intermediate granule according to any one of claims 1 to 5, wherein the low melting point additive is at least one selected from the group of monoglyceride, diglyceride, triglyceride, and polyglycerin fatty acid ester. Production method. The method for producing a starch / resin composite intermediate granule according to claim 6, wherein the monoglyceride is at least one selected from the group of cetylated monoglyceride, organic acid monoglyceride, and fatty acid monoglyceride. Refractory additives, fatty acid metal salts, hydrocarbon-based, A alcohol, aliphatic amide, at least one selected from the group of fatty acid esters, according to any one of the preceding claims 1 to 7 Method for producing composite intermediate granules of fatty acid / resin. The above-mentioned claim that the refractory additive is at least one selected from the group of magnesium stearate, zinc stearate, calcium stearate, aluminum stearate chain, sodium lauryl sulfate, magnesium lauryl sulfate, potassium benzoate, and sodium benzoate. Item 8. The method for producing a composite intermediate granule of starch / resin according to any one of Items 1 to 8.

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