JP6901856B2 - Manufacturing method of starch / resin composite molding processing material - Google Patents

Description

The present invention relates to a method for producing a starch / resin composite molding processing material, 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 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). Regarding the method of manufacturing.

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

According to the present invention, when a starch / resin composite material is used in various fields of application, while emphasizing the above-mentioned environmental measures, uniform and homogeneous physical properties are improved, and molding processability in various molding methods, Manufacture of starch / resin composite molding material that is excellent in workability and can stably and efficiently produce starch / resin composite molding material with little variation even when it contains starch in high concentration. It provides a method.
Even if it contains 50% by weight or more of starch, starch and granular (pellet) thermoplastic resin can be easily and stably kneaded and mixed, and as a raw material, it has excellent workability and quantification, and has morphological stability. It can be used as a molding material for various packaging materials, cushioning materials, agricultural products, daily necessities, etc., including food and drink containers, and a uniform and uniform material can be obtained. Provided is a method capable of producing a starch / resin composite molding processing material having excellent workability and less fading at a low cost and more stably. In particular, it is an object of the present invention to provide a method capable of producing a starch / resin composite molding processed material having less variation as described above even when the starch concentration is 50% by weight or more.

As a result of diligent studies to solve the above problems, the present inventors have found that the method for producing the starch / resin composite molding processed material of the present invention includes addition of starch, a thermoplastic resin, and a low melting point such as a glycerin-based ester. A fluid starch / resin composite material formed by heating and stirring raw materials containing a refractory additive such as an agent and a fatty acid metal ester is resolidified by cooling and stirring, and a thermoplastic resin is used as a core portion on the surface thereof. The process of forming a starch-resin composite intermediate granules coated with starch, and using the starch-resin composite intermediate granules as a raw material, melt-kneading while suppressing material deterioration, and extruding as a resin melt of the starch-resin composite material. It is a manufacturing method including a step and / or a step of forming a cooled starch / resin composite sheet having a skin layer on the surface by calendering.

This method produces a starch-resin composite intermediate granule that is uniform and uniform even if it contains a high concentration of starch, has stable morphological stability, is excellent in workability, and can be stably produced at low cost. By including the manufacturing process, even if starch is contained in a high concentration, it can be uniformly heated and kneaded without fading, has flow stability capable of stable extrusion, and is molded in various molding methods. It is a manufacturing method that has properties, can be molded by controlling thickness accuracy and surface layer formation, has excellent workability, and can be inexpensively and stably manufactured as a starch / resin composite molding process material with little variation. , A manufacturing method that achieves the above object has been reached.

More specifically, the present invention comprises the formation of a starch / resin composite material containing starch, a thermoplastic resin, a low melting point and a high melting point additive by heating and stirring in a high temperature stirrer and mixing, and the formation of a starch / resin composite material. Starch that can be stocked by resolidifying the melted additive components that are cooled and stirred in a cooling stirrer to a predetermined temperature that is lower than the melting temperature of the high melting point additive and higher than the melting temperature of the low melting point additive. The resin composite intermediate granules can be easily and easily formed and produced. Moreover, it is a method including a step of producing intermediate granules that can be stocked in the form of intermediate granules as a raw material of a molding processing material.

The present invention relates to a thermoplastic resin of powdery granular biomass and granular material containing 50% by weight or more of starch, for example, starch (industrial corn (dent corn)) by a step of forming a starch / resin composite intermediate granule. Even if it is a starch / resin composite material, or even in a method for producing a molding processed material using a composite material made of raw materials having different shapes and forms, including a compounding agent such as a dispersant and a compatibilizer, as a raw material. It enables stable supply of raw materials to the manufacturing process, and can produce uniformized and homogenized starch / resin composite molding processed materials with little variation.

The present invention makes full use of a technique of adding a compounding agent 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 a material generated by blending 50% by weight or more of starch. The mechanical properties can be improved by devising not only the material composition but also the molding processing conditions. Moreover, the present invention can suppress the generation of starch odor and the generation of fading.

Further, the method for producing the starch / resin composite molding processed material produced from the starch / resin composite intermediate particles of the present invention includes extrusion molding, T-die extrusion molding, vacuum molding, injection molding, inflation molding, and calender molding. It is possible to produce a starch / resin composite molding material that is suitable for a molding method and has excellent molding processability, is environmentally friendly, has less starch odor, and suppresses fading.

The method for producing a starch / resin composite molding material of the present invention suppresses deterioration of mechanical properties, enables thin molding and deep drawing of deep containers, saves petroleum resources, and reduces carbon dioxide generated during incineration. Since the main raw material is starch, it has a paper texture, but because it has thermoplasticity, it has excellent design and water resistance, making it possible to manufacture molded materials. In addition, when used as a packaging material, it has sufficient product strength when used, but since it can be crushed with a light force after use, it is possible to manufacture a molding processing material that can contribute to reducing the volume of dust.

INDUSTRIAL APPLICABILITY According to the present invention, a consistent production line from compounding to sheet extrusion can be created and commercialized. In addition, all raw materials, including starch, were selected from the positive list for the manufactured sheets, and LCA was performed in the environmental impact assessment, revealing a 32% carbon dioxide reduction effect compared to the life cycle of polypropylene sheets. became.

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 is possible to provide a material that can be sufficiently applied to products and the like.

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

(Manufacturing of starch / resin composite molding processing material)
The method for producing the starch / resin composite molding material of the present invention described above will be described in more detail below.
The method for producing a starch / resin composite molding processing material according to the present invention forms starch / resin composite intermediate granules of stable quality without using special means or equipment, and the starch / resin composite intermediate granules thereof. This is a manufacturing method that can obtain a starch / resin composite molding process material having excellent uniformity and homogeneity and less variation even if it contains 50% by weight or more of starch, which has been difficult to obtain in the past. ..

That is, in the production method of the present invention, starch and a low melting point additive are mixed by heating and stirring, and the melted low melting point additive is entangled with the starch and adhered to the starch containing the melted low melting point additive. Form. Then, the granules of the thermoplastic resin and the high melting point additive are mixed while heating and stirring to uniformly disperse the granules of the starch and the thermoplastic resin to obtain a fluid starch / resin composite material. After that, the fluid starch / resin composite material is cooled with stirring, and at least the melted high melting point additive is resolidified to form the granular material of the thermoplastic resin as the core portion, and the surface of the core portion is formed. This method includes a step of producing a starch-resin composite intermediate granule having a coating layer of a powder or granular material containing a starch containing a low melting point additive.

Further, the process of producing the starch / resin composite intermediate particles is incorporated so as to be supplied to the production process of the starch / resin composite molding processed material using the produced starch / resin composite intermediate particles as a raw material, or separately. 50 starches are produced by producing a starch / resin composite intermediate granule, supplying it as a raw material, and producing a molding processing material, that is, by melt-kneading while suppressing material deterioration and extruding it as a resin melt of a starch / resin composite material. Stable starch / resin composite molding processing material, including the process of producing a starch / resin composite molding processing material with excellent uniformity and homogeneity and always stable quality with little variation even if it is contained in an amount of% by weight or more. It is a method that can be continuously and consistently manufactured.

(starch)
In the method for producing a starch / resin composite molding processed material of the present invention, the component raw material is kneaded through the form of a starch / resin composite intermediate granule, melt-extruded, and starch is produced in the method for producing a starch / resin composite molding processed material. -Raw starch can be used as the starch of the raw material used as the biomass material for forming the resin composite intermediate granules. For example, corn starch, bean starch, tapioca starch, potato starch, wheat starch, rice starch, and fox mackerel starch. , Hishi starch, Hass starch, Sago starch, Warabi starch, Kuzu starch and the like.

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 resin 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.

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 content is less than 20% by weight, the amount of starch having a small specific gravity becomes large as the obtained starch / resin composite molding material, and it becomes difficult to homogenize it as a biomass molding material, and it becomes uniform and homogeneous as a composite molding processing material. It becomes difficult to obtain things.

Moreover, it is necessary to increase the amount of additives. 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 the properties are strong and molding is possible, the obtained starch / resin composite molding material has starch added as a filler, and the properties of the plastic material are strong, it is difficult to reduce the volume, and the greenhouse effect. The contribution to the reduction of gas emissions will decrease, and it will be difficult to obtain a starch / resin composite molding process material as a biomass raw material. Moreover, the molded material contains a large amount of starch as a filler, and the physical properties of the molded material and the uniformity and homogeneity of the composite material fluctuate greatly, making it difficult to obtain a stable material.

In the method for producing a composite molding material of the present invention, when a molding 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, the physical properties and composite of the produced molding material are used. The uniformity as a material and the variation in homogeneity are large, and the variation is large, making it difficult to obtain a stable material.

Biodegradable materials 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 materials 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 of the major axis is exceeded or the size is small, the balance of the amount of adhered granules becomes unbalanced. Therefore, all of them are uniform and homogeneous as starch / resin composite intermediate granules of starch and thermoplastic resin. Inferior in sex. Furthermore, the dispersibility 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. , Use one with an average particle size in the above range.

(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 less variation in molding processability, mechanical strength, etc. 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, one that melts at 100 ° C. or lower, preferably one that melts at 60 to 100 ° C. Additives that are viscous and can function to entangle and adhere to the powder are used. In the present invention, an additive capable of fulfilling at least the above-mentioned properties and functions and coexisting in the starch / resin composite intermediate granules, which is melted at a relatively low temperature, entangled with starch, adhered and added, is provided in the present invention. 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. 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 powder or granular material containing starch to form a 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.

It is necessary to consider the type of thermoplastic resin and compatibility with the additive for the high melting point additive, but starch / resin composite molding processing is uniform and uniform in the processing machine using starch / resin composite intermediate particles as raw materials. 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". To do.

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 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, using the formed starch / resin composite intermediate granules as a raw material, the composite intermediate granules can be melted or melt-kneaded in a processing machine to obtain a uniform and homogeneous composite material, which enables melt extrusion. At the same time, 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)
According to the present invention, by using the starch / resin composite intermediate granules, it is possible to obtain a uniform and uniform starch / resin composite molding processing material with little variation, and to have molding processability in various molding processing methods. In order to obtain materials with excellent properties, 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.

As the additive used for producing the starch / resin composite molding processed material of the present invention, a colorant such as titanium oxide, carbon black, dye, or pigment can be used, if necessary. 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 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 method for producing a starch / resin composite molding material of the present invention, in the production of composite intermediate particles, the fluid starch / resin composite material formed by the high temperature stirrer as described above is cooled in a cooling stirrer. By resolidification, it is possible to obtain a form in which the granular material of the thermoplastic resin is used as the core portion and the coating layer formed of the powder or granular material containing starch as a main component is provided on the surface.

In the present invention, in the method for producing a composite intermediate granule, the starch / resin composite intermediate granules lose their shape until the composite intermediate granules are melt-kneaded in order to produce a starch / resin composite molding processed material which is a product. It has morphological stability to which it is attached with an adhesive force to the extent that starch does not peel off, and can be formed so as to maintain 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 uniformity, homogeneity, molding workability, workability and quantitativeness are improved. can do.

(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. Use the continuous integrated manufacturing equipment for starch / resin composite molding material shown in Fig. 1, which 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. Is manufactured by.

The continuous integrated production of starch / resin composite molding material of the present invention can produce and store starch / resin composite intermediate particles that enable the production of the molding processing material of the present invention. Using the device unit A and the manufactured composite intermediate granules as raw materials, a starch / resin composite molding processed material, which is a product, is manufactured, and / or secondary processing such as calender molding is performed to manufacture a raw material for the final product. It is composed of an apparatus including a starch / resin composite molding processing material manufacturing apparatus B.

For the production of the starch / resin composite intermediate granules, the manufacturing apparatus consisting of each apparatus shown in the starch / resin composite intermediate granule manufacturing apparatus A of the continuous integrated production apparatus for the starch / resin composite molding processing material is used as an independent apparatus or exemplified. As described above, the product is manufactured by a part of the continuous integrated equipment, and the starch / resin composite intermediate particle production equipment unit A is heated and stirred to form a starch mixture of the starch and the melted low melting point additive at a high temperature. Stirrer 1, a cooling stirrer 2 that cools and stirs to form the composite intermediate granules from a starch / resin composite material containing granules of starch and thermoplastic resin and low melting point and high melting point additives, and granulation. A stock tank / supply device that can stock the resulting composite intermediate particles of starch / resin and serve as a supply buffer for the composite intermediate particles used as raw materials so that the starch / resin composite molding processed material can be continuously produced. It is a manufacturing apparatus including.

The starch / resin composite molding processing material is manufactured by the starch / resin composite molding processing material manufacturing apparatus B, and is manufactured and stored in the apparatus A for producing the starch / resin composite intermediate particles. The starch / resin composite intermediate granules are supplied from the stock tank / supply device 3 configured so that the produced starch / resin composite intermediate granules can be continuously supplied as a raw material, and are heat-kneaded to be fluidized starch / resin. A configuration including at least a twin-screw extruder 4 for extruding as a composite material and a uniaxial extruder 5 for stably extruding the kneaded and melted thermoplastic resin as a molten thermoplastic resin starch composite molding material by further raising the cylinder temperature. It is a starch / resin composite molding processing material manufacturing apparatus B.

It is also possible to use the starch / resin composite molding processing material manufacturing apparatus B as a single manufacturing apparatus, and separately prepare a starch / resin composite intermediate granule as a raw material to manufacture the starch / resin composite intermediate particles in a batch manner.

The starch / resin composite molding material continuous integrated manufacturing apparatus used in the present invention is a roller capable of further extruding into a sheet shape and calendering the sheet to control the thickness of the sheet and the formation of a surface layer. It can include a rolling apparatus, a cutting apparatus for pelletizing by extruding in a strand shape and cutting, or extruding in a sheet shape and cutting on the grain of a calender.

(Manufacture of starch / resin composite intermediate particles)
In the method for producing a starch / resin composite molded material of the present invention, the starch / resin composite intermediate granules used as a raw material are produced by the apparatus unit A including the high temperature stirrer and the cooling stirrer shown in FIG. Can be done.
In the production of starch-resin composite intermediate granules, at least one of starch and low melting point additive is heated 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 with stirring, and control heating and stirring so that the mixture has a low melting point additive melted in the starch.

After that, a thermoplastic resin and a refractory additive such as a fatty acid metal salt are 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 and stirred to mix. Form a fluid starch / resin composite material.

Next, the formed fluid starch / resin composite material is transferred to a cooling stirrer, and the refractory additive is mainly 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 containing at least 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 heating-stirring treatment, the starch and low-melting point additive are heated and stirred in a high-temperature stirrer, and the temperature is raised while stirring to melt the starch and the low melting point. Additives are mixed by heating and dried by heating, which is carried out 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 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 heat stirring process, 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, the rotation speed and the stirring time are controlled to melt the components of the low melting point additive, and the temperature is high. Stir and mix the starch and low melting point additive in a 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) Production of starch / resin composite material After making a mixture of starch and a low melting point additive melted with a high temperature stirrer, a high melting point additive such as a granular material of a thermoplastic resin and at least one kind of fatty acid metal salt Is further added, and the mixture is heated and stirred.
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. Stir Mix and heat to stir until a uniformly dispersed fluid starch-resin composite material mixture is formed.

(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 high melting point additive component such as a fatty acid metal salt is mainly cooled, and the melting temperature is reached. It is cooled and stirred so as to be solidified by the following. 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 as shown in FIG. 2a, a starch / resin composite intermediate particle 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 starch / resin composite intermediate particle is a method for producing a form of a starch / resin composite intermediate particle that is easy to handle and enables a stable supply of raw materials to the manufacturing process, and has properties and shapes. After heating and mixing the raw materials of different difficult-to-mix component materials, the fluid composite material is cooled with stirring, and the temperature of the fluid composite material decreases, causing the melted additive component to fall below the melting temperature. It 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, in which the raw materials are solidified to form starch / resin composite intermediate granules.

In the present invention, in the production of a molding process material, raw materials having components having different properties and shapes are conventionally supplied individually or in batches to the production process, which is a composite form called a composite intermediate granule with good handleability. It becomes possible to put it into the manufacturing process of a molding processed material as a raw material of the above, and it is possible to stably supply and quantify the raw material in the manufacturing of a 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 production method of the present invention, the temperature at which the low melting point additive component does not solidify while observing the appearance of the granulated granules and confirming the good appearance of the starch / resin composite intermediate granules. It is discharged from the cooling stirrer in the region, 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.

By controlling the formation status of the composite intermediate particles such as temperature, rotation speed, stirring time, etc. and resolidifying the components of the additive, a coating layer of the powder or granular material containing starch is formed on the surface of the granular material of the thermoplastic resin. By observing and confirming the state of being formed, it is possible to obtain a starch / resin composite intermediate granule having excellent morphological stability while maintaining the morphology and shape of the formed granules and having almost no powder falling off.

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). Further, 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 may flow and deform, so that the shape and shape of the particles are deformed by the impact at the time of dropping. However, it loses its shape and the granules become lumpy, resulting in reduced flow stability.

The method for producing the starch / resin composite intermediate granules by this heating / cooling / stirring step can also be produced in batch. 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.

The present invention uses a starch / resin composite intermediate granules produced by simple and few operations as a raw material to produce a starch / resin composite intermediate granules having good morphological stability without powder falling off. It is possible to obtain a starch / resin composite molding processing material with little variation in quality. Then, it becomes possible to stably and inexpensively prepare a uniform and homogeneous starch / resin composite molding processed material, and it is possible to obtain a stable production method of a biomass composite material.

(Manufacturing of starch / resin composite molding processing material)
In the method for producing a starch / resin composite molding processing material of the present invention, since the produced starch / resin composite intermediate granules are aggregate starch / resin composite materials in which each component material coexists, various molding processing methods In order to manufacture the starch / resin composite intermediate granules as a raw material, the starch / resin composite intermediate granules are manufactured, and the starch / resin composite intermediate granules are processed by the starch / resin composite molding. The production line can be stocked as an intermediate raw material for the starch / resin composite molding processing material during the material manufacturing process, or it can be combined separately from the manufacturing process of the starch / resin composite molding processing material. By providing it as a production line for intermediate granules, it is possible to stably supply starch / resin composite intermediate granules as raw materials, realize stable supply of raw materials with different properties and shapes, and various molding processing methods with little variation. This is to realize a manufacturing method capable of continuously and consistently manufacturing a starch / resin composite molding processed material as a raw material.

The produced starch / resin composite molding material can be further molded into a sheet or film, blow-molded, or vacuum-formed so that it can be supplied as a molding material for a final product.

The starch-resin composite intermediate granules stocked in the manufacturing process of the present invention have a structure in which a thermoplastic resin is used as a core and the outside thereof is covered with a coating layer of starch granules containing a low melting point additive. Since it exists as a uniform granule of the starch / resin composite material having it, for the production of the starch / resin composite molding processing material of various molding processing methods, for example, as in the ordinary plastic molding processing technology, for example, a Hencil mixer , No need to mix starch and additives with a mixer such as a tumbler type mixer, barbary mixer, kneader mixer, etc., just put the starch / resin composite intermediate granules directly into the twin-screw extruder and supply them. The starch and the thermoplastic resin can be uniformly kneaded and mixed by controlling the rotation speed, stirring time, temperature, and the like in the same manner as in the plastic molding process and heating and kneading.

When the starch / resin composite intermediate granules are heated and kneaded in a twin-screw extruder, the heat processing temperature (cylinder temperature) is 100 ° C to 190 ° C, the temperature is below the temperature at which the thermoplastic resin melts, and above the melting point of the additive. Set to the temperature of, and heat and knead. As a result, as a preliminary step for forming a molten resin starch composite mixture of a fluid starch / resin composite molding process material from the starch / resin composite intermediate granules, stable fixed quantity feeding of the material is performed while suppressing shearing and temperature rise. Thoroughly stir and knead the ingredients. 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.

In the present invention, after the starch / resin composite intermediate granules are sufficiently heated and kneaded, the fluid starch / resin composite material is extruded by a uniaxial extruder at a temperature equal to or higher than the melting temperature of the thermoplastic resin, 150, as in the plastic melt extrusion step. By setting the temperature to ~ 220 ° C., setting the extrusion pressure appropriately, and melt-extruding the thermoplastic resin in a stable state, it is possible to melt-extrude the thermoplastic resin in a stable state. It is possible to manufacture a composite molding material.

For extrusion, molding technology such as manufacturing of molded products by extruder, sheet manufacturing by T-die extruder, film manufacturing by inflation molding machine, sheet manufacturing by calender molding machine, molding product manufacturing by injection molding machine, etc. A molding machine can be adopted, and a starch / resin composite molding material having excellent molding processability in various molding methods can be obtained.

In the present invention, a starch / resin composite intermediate granule is used as a raw material, a temperature is set to 150 to 220 ° C. using a T die, and the starch / resin composite molding material is extruded as a sheet to obtain a sheet molding material. be able to.

If the molding temperature exceeds 220 ° C., discoloration or decomposition occurs. In significant cases, the color changes to brown or black, and seizure in the cylinder damages the molding machine. Further, in the molding temperature range of less than 150 ° C., the starch / resin composite molding processing material is discharged in an unmelted state, which is not preferable. In a remarkable case, the shearing force between the cylinder and the screw increases, which causes a trouble as well as an increase in pressure.

The starch / resin composite molded material sheet extruded into a sheet by an extruder is immediately after being extruded, the temperature of the take-up roll is set to 60 ° C. or lower, and the sheet formed to a predetermined thickness is cooled. , It is taken up as a raw fabric roll and wound up, or it passes between three rolling rolls that cool the roll surface by giving the roll a cooling function to the raw fabric roll of the starch / resin composite molding processing material. Then, the sheet is formed into a sheet by a rolling roll and cooled to obtain a starch / resin composite molded sheet having a thickness of 0.1 to 2.0 mm, which is used as a raw material sheet for various molding methods or the sheet is crushed or cut to form granules. By obtaining it, it can be supplied as a molding processing material for raw material pellets suitable for injection molding, inflation molding, and blow molding.

In the present invention, in order to make a sheet-like starch / resin composite molding material raw material roll into a molding material sheet having a surface skin layer whose thickness is controlled by a rolling roll, or molding without a surface skin layer. In order to use it as a material sheet, cooling is performed by giving the roll a cooling function to cool the surface of the roll and passing it between three rolling rolls to control the thickness, the presence or absence of the surface skin layer, and the thickness, and further, the sheet surface temperature. By controlling the temperature of the above, it is possible to produce a desired molded material sheet or a molded material sheet that can be crushed or cut. By molding into a sheet by a rolling roll, the thickness of the starch / resin composite molding processing material sheet becomes uniform, and a homogeneous pellet can be produced. In addition, by forming smooth skin layers on the front and back surfaces of the sheet by the action of the rolling roll, it is possible to produce a material with reduced water absorption after pelletization.

Hereinafter, 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.

As an evaluation of the obtained starch / resin composite molded material, the specific gravity and tensile elongation were measured as the moldable material, and the uniformity and homogeneity were evaluated by paying attention to the fluctuation of the specific gravity and the tensile elongation. In addition, in order to measure the specific gravity and the tensile elongation, the measurement was carried out by the test method described below.
The evaluation method was as follows.

(Embodiment)
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.

(Manufacturing of starch / resin composite molding processing material)
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.
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 attach the glycerin monostearate to the starch contained therein.

(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 The mixture of the starch / resin composite material at 160 ° C. is cooled to 60 to 100 ° C. and cooled and stirred at a rotation speed of 5 to 40 Hz to lower the temperature. Glycerin monostearate, which is a low melting point additive, is used until it is confirmed that glycerin monostearate is attached to the surface, and powders and granules containing the contained starch are attached to the surface to form coated starch / resin composite intermediate particles. Cool and stir at a temperature above the melting point.

(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 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 intermediate particles and the formation ratio of the particles 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, the intermediate granules were evaluated based on the specific gravity and tensile elongation of the produced starch / resin composite molded material and the degree of variation thereof.

(5) Manufacture of Starch / Resin Composite Molding Material A starch / resin composite molding material was manufactured from a stock tank using a starch / resin composite intermediate granule as a raw material using a twin-screw kneading plasticized uniaxial extruder as follows. ..
(5-1) Kneading of Starch / Resin Composite Intermediate Granules Starch / resin composite intermediate granules are continuously charged from a stock tank into a twin-screw kneading thermoplastic extruder to a cylinder temperature of 120 to 190 ° C. and a resin pressure of 1 to 4 MPa. Set, knead and plasticize.
(5-2) Molding of Stardust / Resin Composite Molding Material In order to produce a starch / resin composite molding material, starch / resin composite molding prepared by kneading and plasticizing in the above-mentioned first-stage twin-screw extruder. The processing material was supplied to a second-stage uniaxial extruder whose operating conditions were set to 160 to 210 ° C., which is higher than the melting temperature of polypropylene, and a resin pressure of 3 to 20 MPa, and the starch composite molten polypropylene was extruded. ..

(6) Post-treatment of starch / resin composite molding material The following post-treatment was carried out in order to evaluate the influence on the moldability and workability of the starch / resin molding material formed by the present invention.
(6-1) Preparation of 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 (manufactured by LAB TECH Engineering) and take it up. The temperature of the sheet was set to 55 ° C., and the sheet formed to a predetermined thickness of 0.7 mm was cooled, taken up, and wound on a paper tube.
In addition, if necessary, calendar rolling is performed with three cooling rollers (upper roll: 50 ° C., middle roll: 95 ° C., lower roll: 90 ° C.) to control the thickness of the sheet, or a skin layer on the sheet surface. It is also possible to produce a glossy sheet by controlling the thickness of the roll.
Further, in order to utilize the starch / resin composite molding process material formed by melt extrusion 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 for pelletizing.

Sheet pieces (2 x 20 cm) were sampled and extracted from 10 locations per 100 m of the length of the raw sheet of the molded starch / resin composite molding process material.
(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.

(6-2) 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. Molding conditions: After heating to a set temperature of 450 ° C., molding was performed by a vacuum pressure air machine 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 starch / resin composite intermediate particles produced according to Examples and Comparative Examples were each evaluated according to the evaluation method. Further, the starch / resin composite molding material produced according to Examples and Comparative Examples was used as an evaluation sample, and the molding processability of the starch / resin composite molding material was determined according to the evaluation method, and the uniformity of the material important as the composite molding material. And for homogeneity, variations in tensile elongation and specific gravity were 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.). Vacuum compressed air machine: Wakisaka Engineering Co., Ltd., FVS-500P type was used to vacuum the molded sheet so that it became a conical cup, and it was confirmed whether a deeply drawn 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 evaluation results of the produced composite intermediate particles and the composite molding processed material.

As shown in Table 1, the starch / resin composite intermediate granules of Examples 1 to 3 and the starch / resin composite molding processed material produced by melt extrusion using the composite intermediate granules as raw materials are the materials of each example. It is a composite molding material having an average tensile elongation of 36 to 160% and an average specific gravity in the range of 1.08 to 1.21 measured by the above test method in one rod of the above, and the tensile elongation of each example. The variation of the measured values 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, it is within ± 7% and the specific gravity. The measured value is ± 0, which has no fluctuation range 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, 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 granules can be formed into a sheet, but cannot be molded, or the material is not slippery and cannot be extruded, or the composite intermediate granules. Is too large to be made into a sheet, or as a composite molding material produced by melt extrusion as a molding material, the tensile elongation in one rod is 15%, and the fluctuation of the measured value is 7 to 21%. , The fluctuation range is ± 50%, the average specific gravity is 1.24, the measured value has fluctuation values of 1.19 to 1.26, and the values vary within one lot. Physical properties deteriorate, mechanical properties are poor, or 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.

The method of the present invention, in which a starch / resin composite intermediate granule is produced and then a starch / resin composite molding processed material is produced using the composite intermediate granule as a raw material, has superior physical properties, properties and moldability. It was confirmed that a starch / resin composite molded material can be produced, and it was clarified that it is effective to produce a composite molded material after forming the starch / resin composite intermediate granules of the present invention.

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 compounding compositions of the starch / resin composite molding processing material used in Example 2, in Examples 4 and 5, the amount of monoglyceride compounded was largely changed to 0.1% by weight; 10.0% by weight. In Examples 6 and 7, the blending amounts of zinc stearate and magnesium stearate were significantly changed to 0.5, 0.5; 5.0 and 10.0% by weight, respectively, to granulate each additive. The effects on the conversion and molding processability were 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 from 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 added. Further, 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 done.

It can be seen that sheet molding by a T-die extruder is an effect of the invention, and that 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 molding by various molding methods such as sheet molding by a T-die extruder by supplying raw materials by the manufacturing method of the present invention to manufacture a composite molding processing material. It has an advantage in moldability.

As the method for producing a starch / resin composite molded material using the starch / resin composite intermediate granules of the present invention as a raw material, it is possible to obtain a method for producing the composite molded material and having excellent physical properties of the produced material. As summarized in Table 1, intermediate particles cannot be formed, the specific gravity is not stable, starch flies, or slipperiness during extrusion, even if the same component system is used in the conventional method or the production method using an extreme component composition. Because there is no pressure, the sheet cannot be formed, the bleeding becomes extremely sticky when the sheet is formed, or the intermediate particles stick to each other, the particles become too large, and the molding processability may be hindered, such as being unable to supply to the molding machine. It was confirmed that the method of forming the intermediate granules of the present invention and producing the composite molding material was excellent.

The method for producing the composite molding processing material after forming the starch-resin composite intermediate granules of the present invention is the production of a molded product by an extruder derived from a biomass material that can replace the conventional petroleum-based plastic, and T-die extrusion. It can be used in various molding processing technologies such as sheet manufacturing by machine, film manufacturing by inflation molding machine, sheet manufacturing by calender molding machine, molding product manufacturing by injection molding machine, and a wide range of molding processing technology. It is a useful manufacturing method capable of providing a usable starch / resin composite molding processing material.

Claims (14)

A method for manufacturing starch / resin composite molding materials.
(A) A step of forming a starch-resin composite intermediate granule in which a thermoplastic resin is used as a core portion and the surface of the core portion is coated with a powder or granular material containing starch, a low melting point additive and a high melting point additive.
(B) A process of discharging starch / resin composite intermediate particles and stocking them at room temperature,
(C) Material deterioration due to shearing of the starch / resin composite intermediate granules, a step of heating and kneading the starch / resin composite material into a fluid starch / resin composite material while suppressing the temperature rise of the resin temperature, and (d) melt-kneaded starch / resin composite. viewing including the step of extruding the material,
The thermoplastic resin has a melting temperature higher than the melting point of the high melting point additive,
The low melting point additive is an additive that functions as a lubricant having a melting temperature of 60 to 100 ° C.
The high melting point additive is an additive that functions as a lubricant having a melting point of 100 to 150 ° C., and has a higher melting point than the low melting point additive.
The starch / resin composite molding processing material includes 50% by weight or more of the starch, 20% by weight or more and less than 50% by weight of a thermoplastic resin, 0.1 to 10% by weight of a low melting point additive, and 1.0 to 15% by weight. Contains high melting point additives,
A method for manufacturing a starch / resin composite molding material. In the step (a) of forming a starch-resin composite intermediate granule, a composite material containing starch, a thermoplastic resin, a low melting point additive and a high melting point additive is heated and mixed by heating and stirring, and low melting point and high melting point addition are added. The process of forming a fluid starch-resin composite material in which the agent is in a molten state,
A step of cooling a fluid starch / resin composite material in which a low melting point additive and a high melting point additive are in a molten state to a predetermined temperature equal to or higher than the melting point of the low melting point additive, and at least cooling and solidifying the high melting point additive. as well as,
The first aspect of the present invention includes a step of forming a starch-resin composite intermediate granule in which a thermoplastic resin is used as a core portion and a coating layer having a powder granule containing starch containing a low melting point additive is formed on the surface of the core portion. The method for producing a starch / resin composite molding processing material according to the above. The step (a) of forming the starch-resin composite intermediate granules is a step of heating and mixing the starch and the low melting point additive and heating and stirring until the low melting point additive is in a molten state, the thermoplastic resin granules and the thermoplastic resin. A step of further adding a refractory additive, maintaining the heating temperature at a temperature equal to or higher than the melting temperature of the refractory additive and lower than the melting temperature of the thermoplastic resin, and heating and stirring to form a fluid starch / resin composite material. The method for producing a starch / resin composite molding processing material according to claim 1 or 2, which comprises. In the step (a) of forming the starch / resin composite intermediate granules, the fluid starch / resin composite material formed by heating and stirring is at least the melting point temperature of the low melting point additive and at least the melted additive. A starch in which a thermoplastic resin is used as a core portion and a coating layer having a powder or granular material containing a starch containing a low melting point additive is formed on the surface of the core portion, which includes a step of stirring while cooling to a temperature at which one type cools and solidifies. The method for producing a starch / resin composite molding processing material according to any one of claims 1 to 3, which comprises a step of forming a resin composite intermediate particle.
The starch / resin composite intermediate granules have morphological stability during cooling and stirring at a temperature equal to or higher than the melting point temperature of the low melting point additive in the step (b) of discharging the starch / resin composite intermediate particles and stocking them at room temperature. The starch / resin composite molding process according to any one of claims 1 to 4, which comprises immediately discharging the starch / resin composite intermediate particles in a situation where the starch or the like in the coating layer is not peeled off or destroyed. How to make the material. In the heat kneading step (c), the heat processing temperature is set to 100 to 190 ° C., the number of rotations is controlled, and shearing and temperature rise are suppressed by a biaxial screw to heat knead, and a fluid starch / resin composite material is obtained. The method for producing a starch / resin composite molding processing material according to any one of claims 1 to 5, which is a step of obtaining the material. The method for producing a starch / resin composite molding material according to any one of claims 1 to 6, wherein the heat-kneading step (c) includes a step of extruding under a predetermined temperature and pressure at a melting temperature or higher. The extrusion step (d) is a step of forming a sheet-like material or a strand-like material of the starch / resin composite molding processing material, and pellets are obtained by crushing or cutting the sheet-like material of the cooled starch / resin composite molding processing material. The method for producing a starch / resin composite molding processing material according to any one of claims 1 to 7, which comprises a step of obtaining the above. The starch / resin composite molding material according to any one of claims 1 to 8, further comprising a step of controlling the thickness of the sheet-like material and / or the thickness of the skin layer of the extruded starch / resin composite molding material. Manufacturing method. The method for producing a starch / resin composite molding material according to any one of claims 1 to 9, further comprising a step of cooling a sheet of the extruded starch / resin composite molding material with a rolling roll. The starch / resin composite molding according to claim 9 or 10, which is a step of controlling the thickness of the material sheet-like material and the thickness of the skin layer by cooling with three temperature-controlled rolling rolls. Manufacturing method of processing materials. Claims 2 to 11 wherein the thermoplastic resin is one selected from a polyolefin resin, polystyrene, or ABS resin, and the high melting point additive is an additive that functions as a lubricant having a melting point of 100 to 150 ° C. The method for producing a polystyrene / resin composite molding processing material according to any one of the above items. Refractory additives, fatty acid metal ester is magnesium stearate and or zinc stearate, calcium stearate, fatty acid metal salts, hydrocarbon-based, A alcohol, aliphatic amide, at least one member selected from fatty acid esters The method for producing a fatty acid / resin composite molding processing material according to any one of claims 1 to 12. The starch / resin composite molding processing material contains or does not contain a foaming agent. A starch / resin composite suitable for injection molding, blow molding, extrusion molding, cast film molding, inflation molding, compression molding, calender molding, transfer molding, and rotary molding. Molding Material Pellets or Sheets, Vacuum Molded Products or Vacuum Pressure Air Molded Products, Injection Molded Products, Blow Molded Products, Extrusion Molded Products, Cast Film Molded Products, Inflation Molded Products, Compression Molded Products, Calenders, with or without foaming agents The method for producing a starch / resin composite molding material according to any one of claims 1 to 13 , which is a starch / resin composite molding processing material for producing any of a molded product, a rotary molding product, or a transfer molded product. ..

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