JP2006028308A - Resin composition having new structure, method for producing the same and molded product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive resin composition excellent in mechanical/thermal properties, yielding high gas-barrier film by its processing, enabling a filler to be relatively homogeneously dispersed therein with no need of the filler's organic modification or the like, and also usable as a resin composition having high biodegradability, to provide a method for producing the resin composition, and to provide a molded product using the resin composition. <P>SOLUTION: The resin composition has such a structure that the filler (C) is located at the interface between a resin (A) and a resin (B)[the resin (B) is incompatible with the resin (A) and the resin (A) forms a sea-island structure in the resin (B)]. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, two or more kinds of resins that are incompatible are blended, and a small amount of nanometer (nm) filler is characteristically dispersed to provide a resin having mechanical properties, gas barrier properties, and thermal properties. The present invention relates to a nanocomposite resin composition whose performance is dramatically changed and improved. More specifically, by adding a minute filler to a combination of incompatible resins, the compounded minute filler is dispersed relatively uniformly with almost no aggregation, and is present at a new resin interface. The present invention relates to a nanocomposite resin composition realizing a dispersed state of a filler.

  Resin materials are very demanding as materials that can replace metal, wood, and paper because they are light and strong, have excellent solvent resistance, and can be easily molded by applying heat. Has increased. Even today, the demand remains high, and various products using resin materials having required functions such as containers, sheets, and films are on the market.

  It is a resin material that has been selected and used according to the application so far. However, due to the further development of various applications in recent years, the performance achieved only with existing resin materials will sufficiently satisfy the market requirements. It is no longer possible.

  Particularly in recent years, research and development in the environmental field and electronic material field have become very active, and there are restrictions on the resin raw materials that can be used due to the use conditions. In these fields, the performance required for the resin is often very severe, and there is a need to develop a material that meets the required performance by making some improvements to the resin material that can be used. .

  As a means of solving such problems, research on nanocomposite materials has been progressing that will dramatically improve performance by dispersing nanometer-sized fillers in a resin uniformly without agglomeration. It is out. In this nanocomposite material, the elastic modulus, heat resistance, and gas barrier properties are improved by a small amount of filler as compared with a composite material filled with a conventional filler. So far, research has been conducted on the types and blending ratios and blending methods of resins and fillers that are the main raw materials to be selected, and there are demands for resins in various fields such as improvement of elastic modulus, heat resistance and gas barrier properties. Nanocomposite materials with satisfactory physical properties have been reported. For example, polyamide / montmorillonite nanocomposites and polymethylmethacrylate / palladium nanocomposites have been shown to significantly improve physical properties such as tensile strength, elastic modulus, and heat distortion temperature (Non-patent Document 1). In addition, a composite material composed of polyamide and a modified silicate layer is disclosed (Patent Document 1).

But,
(1) Regarding the mechanical and thermal properties of nanocomposite materials, there is room for further improvement in order to meet the demands from various fields.
(2) In addition, it is not easy to uniformly disperse the filler in the resin on the nanometer order, and if the dispersion is non-uniform, there will be problems such as the target performance not being exhibited. For this reason, a technique for uniformly dispersing the inorganic filler in the resin containing the vinyl polymer compound has been investigated, and methods such as organic modification of the inorganic filler or swelling in water and then dispersion in the resin have been proposed. (Patent Document 2) and a composite material in which a layered clay mineral is dispersed in a thermoplastic polyurethane matrix has been proposed (Patent Document 3). Such a method is disadvantageous in terms of time and cost because the number of steps is increased in that the inorganic filler must be pretreated.
(3) Further, from the viewpoint of environmental problems in recent years, it is desirable to use a material that can be decomposed in a natural environment for these nanocomposite materials. For example, nanocomposites composed of biodegradable polylactic acid and layered silicates are used. There are reports on composite materials (Patent Document 4). However, it is difficult to say that the biodegradability of polylactic acid is superior to other biodegradable resins, and the biodegradable resins generally have a high unit price and are still problematic for industrialization. Therefore, it is necessary to study cheaper biodegradable nanocomposites.
There are issues such as.

“From the basics of polymer-based nanocomposites to the latest development” by Nakatsuji Sumi, published by the Industrial Research Council, published on September 20, 2003 JP-A-62-74957 (Claims) JP 63-215775 A (Claims) JP-A-10-168305 etc. (Claims) JP 2002-363393 A (Claims)

  The present invention has been made to solve the above-mentioned problems, and can be dispersed relatively uniformly without subjecting the filler to organic modification, etc., and in the case of a film having a thermal property, mechanical properties, and a gas barrier property. For an excellent and biodegradable resin, an inexpensive nanocomposite resin composition that can be used as a resin composition that does not impair its biodegradation rate and degree of biodegradation, its production method, and molding using this material The purpose is to provide goods.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the first of the present invention comprises a resin (A), a resin (B) and a filler (C). The filler (C) is a resin (A) and a resin (B) [resin (B) is a resin (A). And a resin (A) forms a sea / island structure in the resin (B)].
A second aspect of the present invention provides the resin composition according to the first aspect, wherein the resin (A) has a higher solubility parameter value (SP value) than the resin (B). In the third aspect of the present invention, the blending weight ratio of the resin (A) to the resin (B) is 95/5 to 5/95, and the blending ratio of the filler (C) is the resin composition (resin (A), resin The resin composition according to the invention 1 or 2 is 0.1 to 20% by weight in (B) and filler (C) based on a total of 100% by weight). 4th of this invention is the difference in the solubility parameter value (SP value) of resin (A) and resin (B) in any one of said invention 1-3 which is 1-20 [MPa] ^1/2 . A resin composition is provided. A fifth aspect of the present invention provides the resin composition according to any one of the first to fourth aspects, wherein the resin (B) is a modified or unmodified polyester, polyether, or polyolefin resin. 6th of this invention provides the resin composition in any one of the said invention 1-5 whose resin (B) is resin which has biodegradability. A seventh aspect of the present invention provides the resin composition according to any one of the first to sixth aspects, wherein the resin (A) is a plasticized starch or a polyvinyl compound. The eighth of the present invention provides the resin composition according to any one of the above inventions 1 to 6, wherein the resin (A) is a plasticized starch and the resin (B) is a maleated polycaprolactone. A ninth aspect of the present invention provides the resin composition according to any one of the first to eighth aspects, wherein the filler (C) is a layered inorganic substance. A tenth aspect of the present invention provides the resin composition according to any one of the first to ninth aspects, wherein the filler (C) is at least one selected from the group consisting of montmorillonite, bentonite, swollen mica and talc. In an eleventh aspect of the present invention, a resin (A) and a filler (C) are kneaded to produce a kneaded product in which the filler (C) is dispersed in the resin (A), and then the kneaded product and the resin (B) [ The resin (B) is incompatible with the resin (A), and the resin (A) forms a sea / island structure in the resin (B)]. The manufacturing method of the resin composition in any one is provided. A twelfth aspect of the present invention provides a molded body made of the resin composition according to any one of the first to tenth aspects of the present invention. 13th of this invention provides the molded object of the said invention 12 which is a sheet | seat, a film, or a container.

According to the present invention,
(1) By blending and kneading two or more incompatible resins with different SP values and fine fillers in a specific order, the filler is dispersed relatively uniformly in the resin without organic modification. In the case of a film, a nanocomposite resin composition having excellent gas barrier properties can be obtained.
(2) By appropriately selecting the SP values of the two incompatible resins, the resin can be stably mixed even if the blending ratio of both resins is greatly changed. Thereby, for example, it is excellent in biodegradability, but a resin such as high-cost polycaprolactone and a resin such as starch that is excellent in biodegradability and inexpensive are mixed at a specific blending ratio, etc. It has become possible to significantly reduce costs.
(3) In this resin composition, one resin forms a morphology in the other resin, that is, a sea / island structure, and the blended filler is present at the interface between the two resins so that the filler is uniform. Dispersed and nanocomposited has been achieved. As a result, it has become possible to significantly reduce the cost while improving the physical properties of various molded articles such as sheets and containers obtained by molding the nanocomposite resin composition.

  The resin composition of the present invention is composed of a thermoplastic resin (A), a resin (B), and a filler [a thermoplastic resin is a plasticizer even if the resin alone is not thermoplastic. Including those that plasticize in a state of containing]. The resin (A) is preferably a resin having a higher SP value than the resin (B), that is, a more hydrophilic resin than the resin (B), and the resin (B) is incompatible with the resin (A). Here, incompatible means that the resin (A) is in the resin (B) when kneaded at a temperature equal to or higher than the melting point (or softening temperature) of the resin having the higher melting point (or softening temperature). It means that they are dispersed to form a so-called sea / island structure. The resin composition is molded into various molded products by injection molding or extrusion molding.

[Resin (A)]
In the present invention, the resin (A) can be used without limitation as long as it has an affinity with the filler (C) described later, and the SP value is higher than that of the resin (B). There is no particular restriction. As the resin (A), a so-called hydrophilic resin which is generally a resin having a high SP value is preferable.
Resins used as the resin (A) include starch, plasticized starch (modified starch, modified starch, gelatinized starch, etc., not including granular materials), polyvinyl alcohol, polyvinyl acetate, ethylene-vinyl acetate. Copolymer (EVA), ethylene-vinyl alcohol copolymer, polyvinylpyrrolidone, polystyrene sulfonic acid, polyalkylpolyamine salt, poly (meth) acrylic acid and other polyvinyl compounds and cellulose, cellulose acetate, carboxymethylcellulose, cellulose acetate pro Examples include pionate and cellulose acetate butyrate. These resins may be plasticized using a plasticizer or the like. As the plasticizer, for example, phosphoric acid esters, aromatic carboxylic acid esters, fatty acid esters, citric acid esters, amides and the like can be used. Moreover, as plasticized starch, what knead | mixed by adding water, glycerol, or its mixture to starch can be used, for example. The degree of polymerization of these resins is not particularly limited as long as it can be used as a molded product such as a film.
In addition, when the two types of resins (A) exemplified above are incompatible and form a sea / island structure, and the difference in SP value is 1 to 20 [MPa] ^1/2 , The resin having the lower SP value can be used as the resin (B) in the present invention.

[Resin (B)]
The resin (B) in the present invention is incompatible with the resin (A), that is, a resin that forms a sea portion when a sea / island structure is formed, and is preferably more than the resin (A). The SP value is small and the SP value difference with the resin (A) is in the range of 1 to 20 [MPa] ^1/2 . Such a resin is not particularly limited as long as the difference in SP value from the resin (A) is in the above range. For example, polycaprolactone, maleated polycaprolactone, polybutylene succinate, polylactic acid, polyethylene terephthalate, polybutylene. Examples thereof include polyolefin resins modified with terephthalate, unsaturated carboxylic acid and derivatives thereof (for example, polyethylene, polypropylene, polystyrene, etc.). These resins (B) may be modified by acid modification, amination or the like in order to optimize the difference in SP value from the resin (A).

  In addition, SP value in this invention is measured using Cerius2 (module is Synthia) by Accelrys by Fedors method (RF Fedors: Polym.Eng.Sci., 14 [2], 147 (1974)). According to the value calculated from the numerical value. More specifically, the resin (B) is a resin having an SP value of 30 or less, preferably 25 or less.

The difference between the SP values of the two types of resins (A) and (B) is preferably in the range of 1 to 18 [MPa] ^{1/2 in} the range of 1 to 20 [MPa] ^1/2 described above, The range of 3-15 [MPa] ^1/2 is more preferable. If the difference in SP value is 1 [MPa] ^1/2 or less, the two types of resins (A) and (B) are likely to dissolve each other, and the sea / island structure in the resin composition of the present invention It is difficult to uniformly disperse the resin (A) and thus the filler in the resin (B). On the other hand, if the difference in SP value is 20 [MPa] ^1/2 or more, the two types of resins (A) and (B) cause a large phase separation, and may exhibit their physical properties as a resin composition. It becomes impossible.

The combination of the two types of resins (A) and (B) includes polycaprolactone and plasticized starch in which the difference in SP value is in the range of 1 to 20 [MPa] ^1/2 , maleated polycaprolactone and plasticized starch. , Polyethylene and plasticized starch, polypropylene and plasticized starch, polyethylene terephthalate and plasticized starch, polybutylene terephthalate and plasticized starch, polylactic acid and plasticized starch, cellulose acetate and plasticized starch, polybutylene succinate and plasticized starch , Caprolactone / butylene succinate polymer (CBS) and plasticized starch, polyethylene and polyvinyl alcohol, polypropylene and polyvinyl alcohol, polystyrene and polyvinyl alcohol, polyethylene terephthalate and polyvinyl alcohol, polybutylene terephthalate and polyvinyl alcohol, A combination of poly (lactic acid) and polyvinyl alcohol, cellulose acetate and polyvinyl alcohol, polybutylene succinate and polyvinyl alcohol, a caprolactone / butylene succinate copolymer (CBS) and polyvinyl alcohol is preferable. Further, when a resin composition having high biodegradability is used, polycaprolactone and plasticized starch are preferable, and a combination of maleated polycaprolactone and plasticized starch is more preferable. As the resin having biodegradability, a polyester resin composed of an aliphatic dicarboxylic acid and an aliphatic diol other than the polybutylene succinate, or a polyester resin composed of an aliphatic hydroxycarboxylic acid or a lactone can also be used.

  The ratio (weight ratio) of the resin (A) to the resin (B) can be selected from the range of about 95/5 to 5/95, but is usually 85/15 to 15/85, preferably 80/20 to 20/80, more preferably about 70/30 to 30/70.

In general, when blending resins that are incompatible with each other, problems such as large phase separation occur when one of the resins is blended by about 30% or more, and the function is substantially improved and exhibited as a resin. I can't.
However, in the present invention, by selecting appropriate SP values of the two types of resins (A) and (B) (to the extent that they are not compatible), one of the resins is blended by about 30% or more. However, it can be made to exist as a resin composition without causing a large phase separation.

  This is because one resin (A) is relatively uniformly dispersed in the nanometer size in the other resin (B) because the SP values of the two types of resins (A) and (B) are in an appropriate range. It is thought that it is because of doing. Furthermore, it was possible to obtain a resin composition having excellent performance as a nanocomposite material by relatively uniformly dispersing the filler here.

  Here, it can be confirmed by TEM observation that one resin is uniformly dispersed in the other resin. The degree to which the resin (A) is dispersed in the matrix of the resin (B) depends on the combination of the resins, but the average particle diameter is 1 μm or less, preferably 0.5 μm or less.

[Filler (C)]
The filler (C) used in the present invention may be a natural product or a synthetic product, and is a clay mineral having a size of nanometer order (several nanometers to several hundred nanometers) having affinity with the resin (A). (Clay), mica, talc and the like are used. Specific clay minerals include smectite montmorillonite, saponite, hectorite, hydelite, nontrolite, kaolin kaolinite, vermiculite vermiculite, other magadiite, kanemite, hydrotalcite, mica. Examples include fluoride, octasilicate, bentonite, swollen mica and the like. These fillers preferably have a layered structure, but it is more preferable to use montmorillonite, bentonite, swollen mica, talc and the like from the viewpoint of availability. For example, when maleated polycaprolactone is used as the resin (B) and plasticized starch is used as the resin (A), montmorillonite is preferable from the viewpoint of affinity with the resin (A). In addition, these fillers can be used without pretreatment such as organic modification, but those subjected to pretreatment such as organic modification can also be used.

  Since the filler (C) has a higher affinity with the resin (A) having a relatively high SP value, it is considered that the filler (C) is relatively uniformly dispersed in the resin (A) by kneading with the resin (A) in advance. . Thereafter, when kneaded with the resin (B), the filler layer is peeled off, so that the resin (A) is cut therefrom and dispersed as islands of a sea / island structure. As a result, a state in which the filler, which is mostly present at the interface, is relatively uniformly dispersed in the resin is achieved. Therefore, it is considered that the improvement in physical properties of the nanocomposite composition is achieved. As described above, when the filler is more evenly dispersed in the resin (A), the resin (A) is more finely cut by exfoliation of the filler by kneading with the resin (B). Since it is considered that the filler can be dispersed relatively uniformly, the filler (C) and the resin (A) are selected so that the combination of the filler (C) and the resin (A) has a higher affinity. Is preferred.

  The proportion of the filler (C) to be blended can be selected from a range of about 0.1 to 20% by weight with respect to the total of 100% by weight of the resin (A), the resin (B) and the filler (C). About 10% by weight. In the resin composition of the present invention, by blending the filler in such a range, the physical properties required for the resin composition such as mechanical and thermal physical properties and gas barrier properties and molded products such as films are remarkably improved. In addition, when the blending ratio of the filler is less than 0.1% by weight, the addition amount is small and the addition effect as the filler cannot be exhibited, so that the improvement of the mechanical and thermal properties of the resin cannot be exhibited. Moreover, even if it exceeds 20 weight%, the improvement of the performance expected as a nanocomposite material is not recognized, and conversely, other physical properties are deteriorated, which is not preferable.

  An example of a transmission electron microscope (TEM) observation photograph image of the resin composition according to the present invention is shown in FIG. It can be seen that MAHPCL becomes a matrix and TPS (which looks white) is dispersed as a domain. It can also be seen that the filler (which appears black) is present at the interface between TPS and MAHPCL. FIG. 2 schematically shows FIG. As can be seen from FIGS. 1 and 2, in the resin composition according to the present invention, the resin (A) is dispersed in the order of several tens to several hundreds of nanometers in the resin (B) that is incompatible with the resin (A). It takes a sea-island structure and has a novel structure in which the blended filler (C) is dispersed almost without agglomeration at the interface between these two resins. This is because the resin (A) having higher affinity and the filler (C) are kneaded in advance to disperse the filler (C) in the resin (A), which is incompatible with the resin (A). It is considered that this is achieved by kneading the resin (B). Accordingly, the present invention includes a method for producing such a resin composition. The kneading here does not require the use of special equipment or means, and includes general equipment and methods such as various mixers and general-purpose extruders.

[Production method]
The resin composition in the present invention is obtained by first kneading the resin (A) and the filler (C) to prepare a kneaded product, and then kneading the kneaded product and the resin (B). The kneading is performed by mixing at or above the melting point (or softening temperature) of a resin having a high melting point (or softening temperature). A conventional method can be used as the kneading method. For example, each component may be prepared by mixing in a dry or wet manner using a mixer such as a tumbler mixer, a Henschel mixer, a ribbon mixer, or a kneader. Furthermore, after premixing with the mixer, the mixture may be kneaded with an extruder such as a single screw or twin screw extruder to prepare pellets, or may be prepared with a kneader such as a heating roll or a Banbury mixer. The kneading temperature is selected according to the melting point or softening temperature of each resin component.

  As described above, in the resin composition of the present invention, it was confirmed that the filler (C) has a novel structure existing at the interface between the resin (A) and the resin (B). This is due to the discovery of the composition and the production method as described above as a result of intensive studies by the inventors. That is, first, the filler (C) is kneaded with a resin (A) having a higher affinity, that is, a relatively large SP value. A kneaded material uniformly dispersed on the order of one hundred nanometers is obtained. Next, when the resin (B) having a relatively small SP value is kneaded with this kneaded product, the solubility parameters of both resins (A) and (B) are appropriately selected, so even if no filler is added. Although the resin (A) has a sea / island structure in which the resin (B) is dispersed, the resin (A) is more finely cut and dispersed by peeling off the filler uniformly dispersed in a size of several tens to several hundreds of nanometers. In addition, it is considered that a novel nano-dispersed structure of the filler that the filler exists at the interface is achieved.

  As described above, the resin (A) is uniformly dispersed in the resin (B) that is incompatible with the resin (A), and the filler (C) is present in the resin interface, so that the filler (C) is uniform in the resin composition. A distributed state is achieved. As schematically shown in FIG. 3, the filler dispersion state is different from the ordered-intercalation type and ordered-flocculation type that have been realized so far, and the exfoliation type in which the filler is ideally dispersed randomly (FIG. 4). It is thought that it is near. In this structure, it is considered that the mechanical and thermal physical properties are efficiently improved from the ideal dispersion state of the filler, and physical properties such as gas barrier properties due to the relatively uniformly dispersed filler are also improved.

  In the resin composition according to the present invention, if necessary, conventional additives such as plasticizers, stabilizers (for example, antioxidants, ultraviolet absorbers, heat stabilizers, light stabilizers, etc.), colorants (Dyes, pigments, etc.), flame retardants, antistatic agents, lubricants, antiblocking agents, dispersants, fluidizing agents, anti-dripping agents, antibacterial agents and the like may be included. These additives can be used alone or in combination of two or more. Furthermore, as long as the dispersion state of the resin and the filler is maintained, a resin other than the resin (A) and the resin (B) may be included.

The resin composition of the present invention thus obtained is injection molding, extrusion molding, vacuum molding, profile molding, foam molding, injection press, press molding, blow molding, gas injection molding, T-die molding, inflation molding. It can be formed into various molded products by calendar molding or the like. Among these forming methods, for example, the film can be processed into a film by forming by various conventional forming methods such as an inflation method and a T-die method. The production rate of the film by the above method is 10 to 50 m / min, preferably 15 to 30 m / min, and the time during which continuous production without film breakage occurs is preferably 3 hours or more, more preferably 10 hours. As described above, it is particularly preferably 24 hours or more.
The film may be uniaxially or biaxially stretched. The stretched film can also be used as a shrink film. The thickness of the film is 5 to 100 μm, preferably 10 to 50 μm. Conventionally, in a resin composition having the same composition that is not nanocomposite, when such a thin film is continuously formed, the film is frequently cut. However, by using the composition of the present invention, the film It can be continuously molded for a long time without cutting.

  The resin composition of the present invention can be used for applications in various fields. For example, the film or sheet produced from the resin composition of the present invention can be used in a wide range of applications as an alternative to conventional polyolefin resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyester resin, polyether resin, polyamide resin, etc. can do. Applications of film include finished packaging materials for bags and pouches; deep drawing for automatic packaging of livestock and processed fishery products; shrink film for packaging by heat shrinkage; Examples thereof include co-stretching with other resins and heat fixing films, and heat fixing films with metal foils. Applications of the sheet include: for secondary processing of food containers, etc .; for general containers including bottles, for surface materials, for light transmissive materials, for moving materials, and the like. Needless to say, these products may be multilayered and can be applied to tubes, pipes, coating materials, patterned molded articles, cables, and other irregularly shaped products. When a combination of biodegradable resins is selected, it is preferably used for articles and applications that are easily left in the environment. Besides a film or sheet, it can also be used as a thick molded product such as a bottle.

[Example]
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In Examples and Comparative Examples, production of various samples and measurement of physical property values were performed under the following conditions.
<Raw materials>
Polycaprolactone: PCL-H7 [manufactured by Daicel Chemical Industries, Ltd.]
・ Starch: Sago palm starch ・ Filler: Kunipia-F Lot.K01255 [Kunimine Kogyo Co., Ltd., purified bentonite]
・ Maleic anhydride: maleic anhydride (special grade reagent)
・ Benzoyl peroxide: Benzoyl peroxide (BPO) (special grade reagent)
<Raw material preparation>
(1) Maleinized PCL (hereinafter MAHPCL)
1 part by weight of maleic anhydride and 0.3 part by weight of BPO were blended with 100 parts by weight of PCL-H7 which had been dried for 12 hours or more in a 50 ° hot air dryer, and kneaded in a small mixer (120 ° C., 50 rpm, 60 This was designated as maleated PCL (MAHPCL).
(2) Plasticized starch (hereinafter TPS)
70 parts by weight of starch, 10 parts by weight of water, and 20 parts by weight of glycerin were blended in a container and mixed well, covered so as not to volatilize as much as possible, and aged for 48 hours in a 60 ° C. hot air dryer. After the aging treatment, the mixture was kneaded under the condition (4) below to obtain plasticized starch (TPS).
(3) TPS / Filler The plasticized starch (TPS) obtained by the above-mentioned kneading and the filler were blended and kneaded again under the condition (4) below to obtain a TPS / filler.
(4) Apparatus for kneading conditions: Small mixer Laboplast mill 50R-150 + R-60 [manufactured by Toyo Seiki Co., Ltd.]
Kneading temperature: 120 ° C
Rotation speed: 50rpm
Kneading time: 60 minutes
[Performance evaluation]
About each of the obtained resin blends, a 2 mm thickness sheet was produced using the hot press machine, and the following physical properties were evaluated.
(1) Evaluation of tensile properties Sheets (2 mm thick) were punched into JIS No. 2 tensile test dumbbells, and tensile properties were evaluated using a universal tensile testing machine. Moreover, the test method was performed according to JIS K-7113.
(2) Evaluation of dynamic viscoelasticity A sheet (2 mm thick) was cut into 10 mm × 50 mm, and dynamic viscoelasticity evaluation (bi-bending sine wave mode) was performed. The evaluation was performed under the following conditions.
<Measurement conditions>
Between chucks: 20 mm
Frequency: 1Hz
Temperature range: -100 to 100 ° C (2 ° C / min)
(3) Electron microscope observation The dispersion state of the filler in the resin blend was confirmed using a transmission electron microscope (TEM).

Example 1
Resin using 47 parts by weight of plasticized starch (TPS) prepared as described above as resin (A), 50 parts by weight of maleated polycaprolactone (MAHPCL) as resin (B), and 3 parts by weight of filler (C) A composition was prepared. This resin composition was prepared by first kneading TPS and filler (C), and then kneading the obtained kneaded material (TPS / filler) and MAHPCL. The kneading of TPS / TPS / filler and MAHPCL was performed under the condition (4).

(Example 2)
A resin composition was prepared in the same manner as in Example 1 except that 45 parts by weight of TPS and 5 parts by weight of filler were used in Example 1.

Example 3
In Example 1, a resin composition was prepared in exactly the same manner as in Example 1 except that 40 parts by weight of TPS and 10 parts by weight of filler were used.

(Comparative Example 1)
Without adding a filler, 50 parts by weight of plasticized starch (TPS) as a hydrophilic resin and 50 parts by weight of polycaprolactone (PCL-H) as a resin incompatible with the hydrophilic resin were used. A resin composition was prepared by kneading under the conditions of a kneading temperature of 120 ° C., a rotation speed of 50 rpm, and a kneading time of 60 minutes using a Toyo Seiki Co., Ltd. product, Laboplast Mill 50R-150 + R-60].

(Comparative Example 2)
In Comparative Example 1, a resin composition was prepared in the same manner as in Comparative Example 1 except that 50 parts by weight of maleated polycaprolactone (MAHPCL) was used as a resin incompatible with the hydrophilic resin.

  Using the resin blends obtained in Examples 1 to 3 and Comparative Examples 1 and 2, sheet molding was performed at 120 ° C. using a hot press machine, and physical properties were evaluated.

  Table 1 shows the physical properties of a sheet (2 mm thick) molded from these resin compositions. From the results in Table 1, it was confirmed that the sheet comprising the resin composition according to the present invention has extremely excellent mechanical properties.

  Moreover, the graph of dynamic viscoelasticity evaluation is shown in FIG. From this, the resin composition consisting of MAHPCL / TPS / filler in which the filler is sufficiently dispersed and nanocomposited does not show any elasticity when the MAHPCL without the filler exceeds the melting point of MAHPCL of around 60 ° C. While flowing, it can be seen that a certain degree of elasticity is maintained even when the temperature exceeds about 60 ° C. Because of this effect, the nanocomposite resin composition consisting of MAHPCL / TPS / filler retains a certain degree of elasticity even when the melting point of the resin is exceeded, thereby dramatically improving workability and stability in molding and extrusion kneading. It can be seen that it has improved.

2 is a TEM image of the resin composition of Example 1 of the present invention. It is a conceptual schematic diagram for demonstrating FIG. It is a conceptual diagram for showing the dispersion state of the filler in the conventional resin composition. It is a conceptual diagram for showing the dispersion state of the filler in the resin composition of this invention. It is a graph which shows the dynamic viscoelasticity of various resin compositions.

Explanation of symbols

1 Filler 2 TPS
3 MAHPCL
4 Matrix resin

Claims (13)

  Resin (A), Resin (B) and Filler (C). Filler (C) is Resin (A) and Resin (B) [Resin (B) is incompatible with Resin (A) A) forms a sea-island structure in the resin (B)].   The resin composition according to claim 1, wherein the resin (A) has a higher solubility parameter value (SP value) than the resin (B).   The blending weight ratio of the resin (A) and the resin (B) is 95/5 to 5/95, and the blending ratio of the filler (C) is the resin composition (resin (A), resin (B) and filler (C The resin composition according to claim 1, wherein the content is 0.1 to 20% by weight. The resin composition according to any one of claims 1 to 3, wherein a difference in solubility parameter value (SP value) between the resin (A) and the resin (B) is 1 to 20 [MPa] ^1/2 .   The resin composition according to any one of claims 1 to 4, wherein the resin (B) is a modified or unmodified polyester, polyether, or polyolefin resin.   The resin composition according to any one of claims 1 to 5, wherein the resin (B) is a biodegradable resin.   The resin composition according to any one of claims 1 to 6, wherein the resin (A) is a plasticized starch or a polyvinyl compound.   The resin composition according to any one of claims 1 to 6, wherein the resin (A) is a plasticized starch and the resin (B) is a maleated polycaprolactone.   The resin composition according to any one of claims 1 to 8, wherein the filler (C) is a layered inorganic substance.   The resin composition according to any one of claims 1 to 9, wherein the filler (C) is at least one selected from the group consisting of montmorillonite, bentonite, swollen mica, and talc.   The resin (A) and the filler (C) are kneaded to produce a kneaded product in which the filler (C) is dispersed in the resin (A), and then the kneaded product and the resin (B) [resin (B) is a resin ( The resin composition (A) is incompatible with the resin (A), and the resin (A) forms a sea / island structure in the resin (B)]. A method for producing a resin composition.   The molded object which consists of a resin composition of any one of Claims 1-10.   The molded article according to claim 12, which is a sheet, a film or a container.