JP4822591B2 - Method for producing thermoplastic resin composition - Google Patents

Description

【００２４】
以上の各例および表１からわかるように、本発明の実施例１、実施例２と参考例１、参考例２は、いずれもＸ線回折においてピークがみられず、分散が極めて良好であり、また、曲げ試験の結果も実施例２、参考例１、参考例２は、比較例のものに比べて優れている。
そして、本発明の実施例１、実施例２は、参考例１、参考例２に比較し出発原料が相違するので、その低粘度のスラリー液を得るまでの時間が大幅に短縮できる。
比較例１及び比較例３をみると、有機化粘土鉱物と樹脂との混練は実施例と同様であるが、その分散性は悪く、曲げ弾性率は低い。これは、本発明のケーキ状含水有機化粘土鉱物と樹脂との混練が重要であることを示している。
参考例２及び比較例３は、いずれも有機化モンモリロナイトを高濃度に含むマスターバッチを作製し、それをポリプロピレンと合わせて、所定量のモンモリロナイトを含む樹脂組成物を製造する例であるが、本発明においても同様にして製造することができる。
実施例１、２と比較例２を比較した場合、有機化モンモリロナイトエマルジョンと混練する比較例２は製造効率が著しく劣る上、最終的に得られる組成物もモンモリロナイトの分散性に劣り、かつ曲げ弾性率も低い。
水で膨潤したのみで有機化処理を行わない粘土鉱物との組成物である比較例４をみると、モンモリロナイト含有量は多いが分散性は悪く、曲げ弾性率も極めて低い。
【００２５】
【発明の効果】
本発明によれば、粘土鉱物の層間に熱可塑性樹脂が導入され，粘土鉱物がサブミクロンからナノメートルオーダーで分散してなる熱可塑性樹脂組成物を簡便な工程で短時間に生産性良く、工業的に有利に製造することができ、その得られる熱可塑性樹脂組成物は機械的性質や耐熱性、ガスバリア性などに優れ、組成物全体が均質であり、自動車用のバンパー、食品用のフィルム等各種の用途がある。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for producing a thermoplastic resin compositionTo the lawRelated. More specifically, the present invention relates to a method for producing a thermoplastic resin composition in which a layered compound is dispersed in a submicron to nanometer order.To the lawIt is related.
[0002]
[Prior art]
In recent years, a nanocomposite in which a layered inorganic compound is dispersed in a nanometer order in a thermoplastic resin has been proposed and attracted attention. Compared to conventional composite materials filled with inorganic fillers, this nanocomposite can provide higher elastic modulus and heat resistance with a small amount of inorganic fillers, and can be reduced in weight and can replace glass fibers. It is also possible to recycle and attracts attention from environmental issues. It has also been reported that gas barrier properties and flame retardancy are imparted.
However, it is not easy to disperse the layered inorganic compound in the thermoplastic resin on the nano order, and various devised techniques have been proposed so far. For example, a method in which an organic cation represented by a quaternary ammonium salt is intercalated into a layered inorganic compound and then a monomer is introduced between the layers and polymerized (Japanese Patent Laid-Open No. 63-215775). A method in which an inorganic compound is dispersed in an organic solvent, a thermoplastic resin is dissolved in the solvent, and both are mixed in solution (Japanese Patent Laid-Open No. 6-93133). An organic layered inorganic compound is dispersed in the organic solvent and heated. A method of injecting and kneading into a place where the plastic resin is melted (JP-A-8-302062), a method of melt-kneading under specific conditions using an organic layered inorganic compound (JP-A-9-2117012) Japanese Laid-Open Patent Publication No. 10-1828), a method in which an organically layered inorganic compound and an oligomer having a functional group are kneaded and then kneaded with a resin. No. 2), a method in which a layered inorganic compound swollen in water or an organic layered inorganic compound swollen in an organic solvent is kneaded together with a resin under specific conditions (Japanese Patent Laid-Open No. 9-183910) Gazette), by applying a solvent-containing clay slurry containing a thermoplastic resin and a large amount of water or a proton donor to a twin-screw extruder, a large amount of water forms a high-pressure atmosphere in the extruder and is finely dispersed in the resin. (Japanese Patent Laid-Open No. 2000-239397) and the like have been proposed.
However, all of the layered inorganic compounds used in these methods employ a dry clay product, and many of them cause secondary agglomeration, and this undergoes a step of solvent dispersion again, which is economically disadvantageous. However, although the interlayer is considerably widened, in the composition dispersed in the resin, the interlayer distance is still measured by X-ray diffraction, and it cannot be said that nano-order dispersion is sufficient. In particular, regarding a nonpolar resin typified by polyolefin, a sufficiently satisfactory technique has not yet been found.
[0003]
[Problems to be solved by the invention]
Under such circumstances, the present invention provides a homogeneous thermoplastic resin composition excellent in mechanical properties and heat resistance, in which clay minerals are dispersed in the order of submicron to nanometer, in a simple process, at low cost. An object of the present invention is to provide an industrially advantageous production method and a thermoplastic resin composition having the above-mentioned characteristics. By using simple means, the interlayer distance of a multilayer structure of clay minerals to be kneaded with a thermoplastic resin can be reduced. The thermoplastic resin is easily and effectively introduced between the layers at the time of kneading while being spread, and the fine and uniform dispersion is sufficiently exerted.
[0004]
[Means for Solving the Problems]
As a result of intensive studies on a method for inexpensively producing a thermoplastic resin composition in which a clay mineral is dispersed on the nanometer order, the inventors have obtained the following knowledge.
Although clay minerals are generally dispersed in water, they are not dispersed in organic solvents, while organic clay minerals are known to be dispersed in organic solvents but difficult to disperse in water. However, if the raw clay as a layered inorganic compound is carefully selected and supplied to the organic treatment, the solvent dispersion process time is shortened and a low-viscosity slurry is obtained, and the organic treatment is also very easily performed. Hydrophilic clay minerals can be changed to hydrophobic. The organic clay mineral that has been subjected to the solid-liquid separation treatment has a multilayer structure with a wide interlayer distance maintained by the organic agent, and the interlayer portion changes from hydrophilic to hydrophobic while retaining the dispersion medium. Therefore, in this state, the dispersion medium held between the layers is relatively easily replaced with the resin by kneading with a thermoplastic resin containing a polymer having a low molecular weight to some extent, and no peak is observed in X-ray diffraction. It has been found that a thermoplastic resin composition in which clay mineral is dispersed on the order of submicron to nanometer order can be easily obtained.
[0005]
  The present invention has been completed based on such findings.
  That is, the present invention
(1) A slurry liquid obtained by refining clay mineral ore using an aqueous solvent is obtained, and an organicizing agent is added to the slurry to make it organic, and an organic clay mineral dispersion liquid in which organic substances are intercalated between clay mineral layers is prepared. Next, a cake-like water-containing organic clay mineral is obtained by solid-liquid separation treatment. The cake-like water-containing organic clay mineral and the thermoplastic resin are combined and melt-kneaded, and the dispersion medium between the clay minerals is thermoplastic. A method for producing a thermoplastic resin composition to be substituted with a resin;
(2) In (1), the slurry liquid has a solid content concentration of 0.1 to 50.0% by mass, and the cake-like hydrous organized clay mineral has a solid content concentration of 5.0 to 90.0% by mass. A method for producing the thermoplastic resin composition according to claim 1,
(3) The method for producing a thermoplastic resin composition according to (1) or (2), wherein the solid-liquid separation treatment is performed by centrifugation or a filter press.
(4) The method for producing a thermoplastic resin composition according to any one of (1) to (3), wherein the thermoplastic resin contains a polyolefin resin,
(5) After melt-kneading a polyolefin resin having a mass average molecular weight of 50,000 or less, which is at least 5% by mass of the total resin amount, and a cake-like water-containing organic clay clay mineral, this product and the remaining other polyolefin resin (4) The method for producing a thermoplastic resin composition according to (4), wherein the resin is melt-kneaded togetherand,
(6) The method for producing a thermoplastic resin composition according to (4) or (5), wherein at least a part of the polyolefin resin contained in the thermoplastic resin has polarity.,
TheIt is to provide.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
  Method for producing the thermoplastic resin composition of the present inventionTo the lawThe thermoplastic resin used is not particularly limited as long as it is a thermoplastic polymer compound. For example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polystyrene, and ABS are used. Resin (acrylonitrile-butadiene-styrene copolymer resin), AS resin (acrylonitrile-styrene copolymer resin), polymethyl methacrylate, polyamide, polyacetal, polycarbonate, polyphenylene sulfide, polyphenylene ether, polyether ether ketone, polysulfone, polyether sulfone , Polyamideimide, polyetherimide, thermoplastic polyimide, natural rubber, isoprene rubber, chloroprene rubber, styrene rubber, nitrile Beam, ethylene - propylene rubber, butadiene rubber, styrene - butadiene rubber, butyl rubber, epichlorohydrin rubber, acrylic rubber, urethane rubber, fluorine rubber, the use of silicone rubber or the like preferred. These may be used individually by 1 type, and may be used in combination of 2 or more types.
  In addition, the present invention containing a high concentration of clay mineralsTarget thermoplastic resinIf the composition is obtained, it is convenient to include an arbitrary amount of clay mineral as a masterbatch. In the case of preparing such a composition, it is advantageous to select a thermoplastic resin having a mass average molecular weight of 50,000 or less. Further, a thermoplastic resin having a polar group and having a mass average molecular weight of 50,000 or less is selected. It is advantageous to choose. In particular, when selecting a polyolefin resin that does not inherently have a polar group, selecting a polyolefin resin having a polar group modified with, for example, maleic anhydride improves the miscibility with clay minerals, and This is advantageous because aggregation of the layered compound can be suppressed.
[0007]
The main component of the raw clay mineral used as a starting material, for example, montmorillonite, is a silicate mineral having a layered structure, for example, a tetrahedral sheet layer composed of silicic acid-an octahedral sheet layer containing Al, Mg, etc.- It is a substance having a layered structure in which tetrahedral sheet layers made of silicic acid are stacked and bonded to form a single crystal layer, and the crystal layers are laminated. A metal cation intervenes between crystal layers having a thickness of about 1 nanometer and a surface size of about 100 to 1000 nanometers in average in length and width, and this metal cation can easily exchange with other cations. Can do.
As such clay mineral ore, in addition to those mainly composed of montmorillonite having a hydrophilic and layered structure such as bentonite and acid clay, which are natural clays, saponite, hectorite, piderite, stevensite, nontronite, Examples thereof include vermiculite, mica, and fluorinated mica. Such raw stones may be used alone or in combination of two or more.
The aqueous solvent is a solvent containing water or a proton donor and is not particularly limited. For example, water, acetone, methanol, ethanol, propanol, diethylene glycol, ethylene glycol, propylene glycol, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, Examples include ethylene glycol monoacetylate, ethylene glycol diacetylate, polyethylene glycol, and polypropylene glycol. These may be used singly or in combination of two or more, but water is particularly preferred, and those in which one or several to 100 parts by volume of these organic substances are mixed with 100 parts by volume of water are also preferred. . In addition, the solvent containing water or a proton donor may contain a solvent or an additive other than water or the proton donor as desired, as long as the object of the present invention is not impaired.
[0008]
5 parts by weight of a water-soluble solvent, preferably 10-15 parts, are mixed in a tank with respect to 1 part of a clay mineral ore that has been crushed to a diameter of 0.1 to 20 mm in advance for water tanks. The mixture is stirred for 1 to 10 hours, preferably 2 to 3 hours, to obtain a mixed dispersion solution. Impurities are separated and removed from the mixed dispersion solution using a centrifugal separator to obtain a slurry liquid mainly composed of clay minerals.
[0009]
The concentration of the clay mineral in the slurry thus obtained is not particularly limited as long as it is a sufficiently dispersible concentration, but is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, particularly preferably. It is the range of 1-5 mass%. If the concentration of the clay mineral is less than 0.1% by mass, more processes are required to obtain the required amount of cake-like water-containing organic clay clay, or the container for preparing the slurry becomes larger, which increases the cost in terms of equipment, It is not preferable. On the other hand, when the concentration exceeds 20% by mass, the viscosity of the slurry increases and stirring becomes difficult.
[0010]
An organic agent is added to a slurry liquid containing only clay minerals such as montmorillonite, and the mixture is stirred for 5 to 60 minutes to make the clay minerals organic by intercalation. Heat to. By this operation, the organic agent enters the interlayer of the clay mineral and becomes hydrophobic, and the clay mineral swells and the interlayer is expanded.
According to this method, since a carefully selected product obtained directly from the raw stone is used, a slurry solution having a low viscosity in a very short time (about 1/8 or less of the conventional one) as compared with a method in which solvent is dispersed using a refined and dried clay mineral Can be prepared, and the introduction of the organic agent can be facilitated, whereby the desired resin composition can be efficiently produced.
The amount of the organic agent added to the clay mineral slurry liquid such as montmorillonite is 0.1 to 5 times, preferably 0.5 to 1.5 times the cation exchange amount (CEC) of the clay mineral. It is a range. If the addition amount of the organic agent is less than 0.1 times, the clay mineral is insufficiently organized and the interlayer is difficult to spread, and there is a possibility that a resin composition in which the clay mineral is sufficiently finely dispersed may not be obtained. If it exceeds, the effect beyond it cannot be expected, but it becomes disadvantageous economically, and is not preferable.
[0011]
As the organic agent, an organic compound having a molecular weight in the range of 10 to 10,000,000, preferably in the range of 200 to 10,000 can be used. If the compound has a molecular weight of less than 10, there is a risk of volatilization when the clay mineral and the resin are kneaded. If the compound is greater than 10,000,000, the viscosity at the time of kneading becomes too high, and there is a risk that homogeneous mixing may not be possible. is there.
Examples of the organic agent include at least one selected from (1) a metal salt of sulfonic acid, a metal salt of phosphonic acid, a metal salt of carboxylic acid, and (2) an onium salt. These organic agents can have a function of dispersing clay minerals (dispersing clay minerals uniformly and finely in a thermoplastic resin).
[0012]
Specific examples of the compound (1) include alkyl sulfonates such as sodium dodecyl sulfonate, alkyl aryl sulfonates such as sodium alkyl benzene sulfonate, aryl sulfonates such as sodium benzene sulfonate, sodium dodecyl phosphonate. Alkyl phosphonates such as sodium alkyl benzene phosphonate, aryl phosphonates such as sodium benzene phosphonate, and the like. The metal in the metal salt is preferably sodium, potassium, calcium, magnesium, aluminum or the like.
Specific examples of the onium salt (2) include octylammonium chloride, octylammonium bromide, dodecylammonium chloride, dodecylammonium bromide, octadecylammonium chloride, octadecylammonium bromide, aminododecanoate and other ammonium salts, phosphonium salts and the like. Can be mentioned.
[0013]
Next, the organic clay mineral-containing liquid obtained by organizing the clay mineral is subjected to a solvent removal treatment by applying a centrifuge or a filter press to remove the metal cation extruded from the interlayer and the unreacted organic agent by cation exchange. A cake-like water-containing organic clay mineral having a wide interlayer distance and good miscibility with the resin and easy kneading operation is obtained. The solid content concentration of the cake-like hydrous organized clay mineral is in the range of 5 to 90% by mass, preferably 20 to 85% by mass, more preferably 35 to 70% by mass. If the solid content concentration is less than 5% by mass, when a necessary amount of clay mineral is kneaded into the thermoplastic resin, a large amount of evaporated water is required and excessive energy is required, and a wide interlayer distance is not provided. In addition, when the solid content concentration exceeds 90% by mass, even when melt-kneaded with a thermoplastic resin, the resin composition obtained is less likely to intervene between the layers of the clay mineral, and the dispersibility of the clay mineral is insufficient. Therefore, the dispersion effect does not appear and the characteristics are inferior.
The cake-like water-containing organic clay clay thus obtained and the thermoplastic resin are combined and melt-kneaded with a twin-screw kneader or the like to maintain the layer between clay minerals having a layered structure with increased hydrophobicity. The replacement of the dispersion medium and the thermoplastic resin thus made is performed more smoothly than in the conventional example, and a fine dispersion state of the clay mineral in the resin is observed, and a desired thermoplastic resin composition is obtained. The melt kneading is performed at a temperature not lower than the melting temperature of the thermoplastic resin so that the resin does not change, and the thermoplastic resin melts and exhibits fluidity to disperse the clay mineral. Furthermore, although the dispersion medium discharged by the substitution is removed from the system by evaporation, since the solid content concentration of the cake-like water-containing organic clay mineral is 5 to 90% by mass, between the clay mineral layers as the dispersion medium evaporates. It appears that space is created and adapted to the introduction of the thermoplastic resin. Thereby, the dispersion of the clay mineral becomes finer.
At this time, the blending ratio of the thermoplastic resin and the cake-like water-containing organic clay mineral is 0.01 to 100 parts by mass, preferably 0.03 to 50 parts as a raw clay mineral with respect to 100 parts by mass of the thermoplastic resin. It is good to choose so that it may become a mass part, More preferably, it is 0.5-10 mass part.
[0014]
  In this kneading, it is preferable to use a thermoplastic resin containing a polyolefin resin. Then, a polyolefin resin having a mass average molecular weight of 50,000 or less, which is a thermoplastic resin component, and a cake-like swollen clay mineral are combined and melt-kneaded to prepare a masterbatch, and this and another polyolefin resin Can be melt-kneaded together.
  The polyolefin resin having a mass average molecular weight of 50,000 or less of the resin component is advantageously one containing 5% by mass or more in the thermoplastic resin composition. When the mass average molecular weight exceeds 50,000, it becomes difficult for the polyolefin to enter between the layers constituting the clay mineral, so that the clay mineral is difficult to disperse. Moreover, if it is not 5 mass% or more, the effect using this polyolefin resin is small.
  As described above, it is preferable that at least a part of the polyolefin-based resin contained in the thermoplastic resin has polarity.
  The present inventionManufacturing methodIs a heat which contains 0.01 to 100 parts by mass of the clay mineral per 100 parts by mass of the thermoplastic resin and in which no clear peak due to the clay mineral is observed by X-ray diffraction. A plastic resin composition is also provided.
  Thus, the thermoplastic resin composition in which clay particles having a thickness of 1 to 20 nanometers and a length of 50 to 1000 nanometers are randomly dispersed in the resin is a simple process by the method of the present invention described above. And can be manufactured inexpensively. It has excellent mechanical and thermal properties, gas barrier properties, etc., and is used for automobile bumpers, food films and the like.
[0015]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the measurement of the X-ray diffraction and bending elastic modulus of the resin composition obtained in each example was performed according to the following method.
(1) X-ray diffraction
Using an X-ray diffractometer, the characteristic X-ray of Cu—Kα was used, and the scanning speed was 1 ° / min and 2θ = 0.8 to 40 °.
(2) Flexural modulus
Measurement was performed in accordance with JIS K7203.
Example 1
After mixing 1 part by mass of Yamagata rough bentonite (main component composition montmorillonite) in 10 parts by mass of an aqueous solvent (water only), stirring and dispersing in a tank at 20 ° C. for 2 hours, using a centrifuge A slurry liquid containing only a montmorillonite main component having a solid content concentration of 3% was prepared. The viscosity of this slurry liquid was 45 mPa · sec [measured at a rotational speed of 60 rpm with a B-type viscous juice B8M (manufactured by Tokyo Keiki Co., Ltd.)]. To this, 1.5 parts by mass of a silicone quaternary ammonium salt was added and stirred to make it organic, and then dehydrated by a filter press. The cake-like product obtained had a solid content of 48% by mass.
Next, 100 parts by weight of polypropylene having a weight average molecular weight of 17000 (a polypropylene having a weight average molecular weight of 73,000 added with 0.3 mass of organic peroxide to lower the molecular weight) and 18 parts by weight of the cake-like product were mixed into a biaxial kneader. And kneaded at 250 ° C. to prepare a resin composition.
The obtained resin composition contained 5.3% by mass of montmorillonite.
A press sheet of this composition was prepared and X-ray diffraction was performed.
[0016]
Example 2
After mixing 1 part by weight of Yamagata rough bentonite (main component montmorillonite) in 10 parts by weight of an aqueous solvent (water only), stirring and dispersing in a tank at 25 ° C. for 2 hours, using a centrifuge A slurry liquid containing only a montmorillonite main component having a solid content concentration of 5% was prepared. To this was added 3 parts by mass of dimethyl distearyl ammonium chloride, and the mixture was stirred for 60 minutes at 60 ° C. to make it organic, and then the solvent was removed by a filter press. The cake-like product obtained had a solid content concentration of 60% by mass.
Next, 45 parts by mass of polypropylene having a mass average molecular weight of 21000 (manufactured by Sanyo Chemical Industries, Ltd., trade name: Yumex 1010), 55 parts by mass of polypropylene having a melt index (MI) of 30 g / 10 min, and 17 parts by mass of the cake-like product Was kneaded at 250 ° C. using a biaxial kneader to prepare a resin composition.
The obtained resin composition contained 4.8% by mass of montmorillonite.
A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
[0017]
As a reference example, an example using a commercially available refined and dried clay mineral is shown.
Reference example 1
3 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was added to 97 parts by mass of water, and the mixture was stirred and dispersed for 24 hours. The end of dispersion depends on the conductivity. The viscosity of this dispersion was 102 mPa · sec [measured in the same manner as in Example 1]. 3 parts by mass of dimethyl distearyl ammonium chloride was added to this dispersion, and the mixture was stirred at 60 ° C. for 80 minutes to be organic, and then dehydrated by a filter press. The cake-like product obtained had a solid content concentration of 60% by mass.
Next, 100 parts by mass of polypropylene having a mass average molecular weight of 17,000 (a polypropylene having a mass average molecular weight of 73,000 added with 0.3% by mass of an organic peroxide to lower the molecular weight) and 18 parts by mass of the cake are biaxially kneaded. A resin composition was prepared by kneading at 250 ° C. using a machine. A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
[0018]
Reference example 2
4 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was added to 96 parts by mass of water, and the mixture was stirred and dispersed for 24 hours. The end of dispersion depends on the conductivity. 4 parts by mass of a silicone quaternary ammonium salt was added to this dispersion and stirred for 80 minutes at 60 ° C. to make it organic, and then dehydrated by a filter press. The cake-like product obtained had a solid content concentration of 66% by mass.
Next, 50 parts by mass of polypropylene having a mass average molecular weight of 21,000 (described above) and 152 parts by mass of the cake-like product were kneaded at 250 ° C. using a biaxial kneader to prepare a master batch. Next, 84 parts by mass of polypropylene of 10 g / 10 min and 16 parts by mass of the master batch were blended and kneaded at 250 ° C. with a biaxial kneader to prepare a resin composition.
A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was created by injection molding and the bending test was done. The results are shown in Table 1.
[0019]
Comparative Example 1
3 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was stirred and dispersed in 97 parts by mass of water, 3 parts by mass of dimethylstearyl ammonium chloride was added, and the mixture was stirred for 80 minutes at 65 ° C. to make it organic. Then, it dehydrated with the filter press. The obtained cake was dried and then pulverized to obtain organic montmorillonite.
Next, 45 parts by mass of polypropylene having a mass average molecular weight of 21000 (supra), 50 parts by mass of polypropylene of 30 g / 10 min, and 12 parts by mass of the above-mentioned organic montmorillonite are heated to 250 ° C. using a biaxial kneader. And kneaded to prepare a resin composition.
A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
[0020]
Comparative Example 2
After 3 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was stirred and dispersed in 97 parts by mass of water, 3 parts by mass of dimethylstearyl ammonium chloride was added and stirred at 60 ° C. for 80 minutes to make it organic. An organic montmorillonite emulsion was obtained.
Next, 45 parts by mass of polypropylene having a mass average molecular weight of 21,000 (supra), 50 parts by mass of polypropylene of 30 g / 10 min, and 166 parts by mass of the above organic montmorillonite emulsion were mixed and kneaded at 150 ° C. with a twin-screw kneader. did. However, it is considered that mass production is difficult because there is too much water and the discharge amount is extremely small.
A press sheet was prepared using the slightly obtained pellets, and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
As a result of X-ray diffraction, a very broad curve was shown, and a slight peak was observed at 38 °. This indicates the presence of clay minerals at various levels of interlayer distance. This is probably because there was a lot of water, so the amount of resin was small, and sufficient shearing force was not applied.
[0021]
Comparative Example 3
After 4 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) was stirred and dispersed in 96 parts by mass of water, 2 parts by mass of dimethylstearylammonium chloride was added and the mixture was made organic as in Comparative Example 2. And dehydrated by a filter press. The obtained cake was dried and then pulverized to obtain organic montmorillonite.
Next, 50 parts by mass of polypropylene having a mass average molecular weight of 21,000 (described above) and 75 parts by mass of the above-mentioned organic montmorillonite were kneaded at 180 ° C. using a biaxial kneader to prepare a master batch. Next, 87 parts by mass of polypropylene of MI 10 g / 10 min and 13 parts by mass of the master batch were blended and kneaded at 250 ° C. with a biaxial kneader to prepare a resin composition.
A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
[0022]
Comparative Example 4
20 parts by mass of montmorillonite (Kunimine Kogyo Co., Ltd., trade name: Kunipia F) and 80 parts by mass of water were stirred and mixed with a mixer to obtain montmorillonite swollen with water.
Next, using a biaxial kneader, 45 parts by mass of polypropylene having a mass average molecular weight of 21,000 (supra), 50 parts by mass of polypropylene of MI 30 g / 10 min, and 30 parts by mass of montmorillonite swollen with water described above, The resin composition was prepared by kneading at 180 ° C.
A press sheet of this composition was prepared and X-ray diffraction was performed. Moreover, the test piece was produced by injection molding and the bending test was done. The results are shown in Table 1.
[0023]
[Table 1]

[0024]
As can be seen from each of the above examples and Table 1, none of Examples 1 and 2 of the present invention, Reference Example 1 and Reference Example 2 show a peak in X-ray diffraction, and the dispersion is extremely good. In addition, the results of the bending test are excellent in Example 2, Reference Example 1, and Reference Example 2 as compared with the comparative example.
And since Example 1 and Example 2 of this invention differ in a starting raw material compared with the reference example 1 and the reference example 2, the time until the low-viscosity slurry liquid is obtained can be reduced significantly.
In Comparative Example 1 and Comparative Example 3, the kneading of the organized clay mineral and the resin is the same as in the example, but the dispersibility is poor and the flexural modulus is low. This indicates that kneading the cake-like hydrous organic clay mineral of the present invention with a resin is important.
Reference Example 2 and Comparative Example 3 are both examples in which a masterbatch containing organic montmorillonite at a high concentration is prepared and combined with polypropylene to produce a resin composition containing a predetermined amount of montmorillonite. In the invention, it can be produced in the same manner.
When Examples 1 and 2 were compared with Comparative Example 2, Comparative Example 2 kneaded with the organic montmorillonite emulsion was extremely inferior in production efficiency, and the composition finally obtained was also inferior in dispersibility of montmorillonite and flexural elasticity. The rate is also low.
Looking at Comparative Example 4, which is a composition with clay mineral that is swollen only by water and not subjected to organic treatment, the content of montmorillonite is large but the dispersibility is poor, and the flexural modulus is also extremely low.
[0025]
【The invention's effect】
According to the present invention, a thermoplastic resin is introduced between layers of clay minerals, and a thermoplastic resin composition in which clay minerals are dispersed on the order of submicrons to nanometers is produced in a simple process with good productivity in a short time. The resulting thermoplastic resin composition is excellent in mechanical properties, heat resistance, gas barrier properties, etc., and the entire composition is homogeneous, such as bumpers for automobiles, films for foods, etc. There are various uses.

Claims (6)

  A slurry liquid obtained by refining a clay mineral ore using an aqueous solvent is obtained, and an organicizing agent is added to the slurry liquid to prepare an organic clay mineral dispersion liquid in which organic substances are intercalated between clay mineral layers. A cake-like water-containing organic clay mineral is obtained by solid-liquid separation, and the cake-like water-containing organic clay mineral and the thermoplastic resin are combined and melt-kneaded, and the dispersion medium between the clay mineral layers is replaced with a thermoplastic resin. A method for producing a thermoplastic resin composition, characterized by comprising:   The slurry liquid has a solid content concentration of 0.1 to 50.0 mass%, and the solid content concentration of the cake-like water-containing organic clay mineral is 5.0 to 90.0 mass%. A method for producing the thermoplastic resin composition according to 1.   The method for producing a thermoplastic resin composition according to claim 1 or 2, wherein the solid-liquid separation treatment is performed by centrifugation or a filter press.   The method for producing a thermoplastic resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin contains a polyolefin resin.   After melt-kneading a polyolefin resin having a mass average molecular weight of 50,000 or less, which is at least 5% by mass of the total resin amount, and a cake-like water-containing organic clay mineral, further, this and other remaining polyolefin resin The method for producing a thermoplastic resin composition according to claim 4, wherein melt kneading is performed together. 6. The method for producing a thermoplastic resin composition according to claim 4, wherein at least a part of the polyolefin-based resin contained in the thermoplastic resin has polarity .