JP2009023874A - Heat-resistant easily-dispersible organic clay and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a heat-resistant easily-dispersible organic clay by reacting a cristobalite-containing organic clay (bentonite) with a silane compound (silane coupling agent) to fix the silane compound on a crystal surface and end face. <P>SOLUTION: A half-dried cristobalite-containing organic clay is mixed with a silane compound optionally dissolved in an organic solvent such as methanol, ethanol or acetone, and a prepared mixture is dried and pulverized. Alternatively, a cristobalite-containing aqueous clay dispersion is mixed with an organic cation, and a silane compound preliminarily dissolved in an organic solvent, and a prepared mixture is dried and pulverized to produce the objective heat-resistant white easily-dispersible organic clay. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat-resistant white easily dispersible organoclay excellent in heat resistance and easy dispersibility, and a method for producing the same.

  The organic clay produced by modifying the crystal surface of the clay with an organic cation is peeled and dispersed one layer at a time in the nano-sized layered crystal structure of the organic clay in various resins. In recent years, organic clay has attracted attention as a functional filler agent for the purpose of improving mechanical properties such as elastic modulus and heat distortion temperature, flame retardancy, and gas barrier properties. .

  However, when this organoclay is kneaded in a heat-melted resin at about 150 ° C. or higher, the long-chain alkyl group of the quaternary ammonium that is an organic cation adsorbed on the crystal surface of the organoclay is thermally decomposed and discolored. As a result, the resin is colored or the dispersibility of the organic clay in the resin is reduced, so the mechanical properties of the resin are not improved, and therefore, the use of the resin containing the organic clay is limited, Moreover, the resin which can use the organoclay has a problem that the melting temperature is limited to a resin having a melting temperature of about 150 ° C. or less.

  Therefore, the present inventors have intensively studied to solve the above problems, and have previously proposed the technique shown in Patent Document 1.

JP 2004-155644 A

  The previously proposed technique is to add and mix an antioxidant previously dissolved in an organic solvent after the dehydration process, in which the interlayer distance, which is the distance between the organic clay crystals, has spread to 90 mm or more, that is, before the drying process. Then, an antioxidant is inserted between the crystal layers of the organic clay (intercalated), dried, pulverized, or a mixture of an antioxidant dissolved in an organic cation and an organic solvent is added to the clay water dispersion, By mixing, intercalating the organic cation and antioxidant between the crystal layers of the clay, drying, pulverizing, and adding heat resistance to the organic clay, further, before the drying step Add silane compound dissolved in organic solvent such as methanol, ethanol, isopropyl alcohol or organic solvent such as acetone, mix, dry, powder Thus, the present invention relates to an organic clay capable of imparting easy dispersibility to the organic clay and a method for producing the same, and in a state where the distance between crystal layers of the organic clay is sufficiently widened, an antioxidant and a silane compound are added. By adding, mixing, drying, and pulverizing, even if kneaded with a resin at a high temperature of 150 ° C. or higher, the color does not change, heat resistance is improved, and easy dispersibility is to be imparted.

  However, in the previously proposed technique, when the above-mentioned antioxidant and silane compound are added and mixed with the organic clay and the resin are melt-kneaded, the antioxidant is an organic clay crystal. Although it is not enough to prevent thermal decomposition of quaternary ammonium, which is an organic cation adsorbed on the crystal surface of the organic clay, the antioxidant is not fixed between the crystal layers by scattering from the interlayer to the outside. The problem of not whitening automatically.

  Therefore, the present inventor conducted intensive research and reacted a clay containing cristobalite as a raw material with an organic cation and a silane compound (silane coupling). By fixing the silane compound in the crystal interlayer surface and end face of the organic clay, it is possible to prevent the quaternary ammonium salt from being deteriorated by heat without using an antioxidant, and the heat resistance is improved, and Heat-resistant white easily dispersible organic clay in which silane coupling does not go out from the outer crystal layer of the organic clay particles to the outside even when the organic clay and resin are melt-kneaded, and also swells in an organic solvent, and a method for producing the same Is to provide.

  That is, the present inventors have intensively studied to solve the above problems, and as a result, an organic clay containing cristobalite (bentonite) and a silane compound (silane coupling) are reacted to convert the silane compound into an organic clay. Heat-resistant white easily dispersible organoclay can be obtained by fixing to the crystal interlayer crystal surface and the end face, and silane coupling can be reactive and fixed only on the end face of the crystal in the case of organoclay not containing cristobalite. Even though it can impart easy dispersibility, it cannot prevent deterioration of the organic cation adsorbed on the crystal surface due to heat and does not show improvement in heat resistance, so cristobalite is included. By using the organic clay, it was found that the silane coupling was firmly fixed on the crystal surface of the organic clay, thereby completing the present invention. It was.

  That is, in the present invention, a silane compound is directly added to an organic clay containing cristobalite in a semi-dry state, or a silane compound previously dissolved in an organic solvent such as methanol, ethanol, acetone is added and mixed, Dry and pulverize, or add and mix organic cation and silane compound dissolved in organic solvent directly into clay aqueous dispersion containing cristobalite, and dry and pulverize By obtaining a heat-resistant white easily dispersible organic clay that does not change color even when kneaded with a resin at a high temperature of 150 ° C. or higher, and directly adding a silane compound to the semi-dried organic clay before the drying step Or, add silane compound dissolved in alcohol such as methanol, ethanol, isopropyl alcohol or organic solvent such as acetone. , Mixed and dried, thereby obtaining a heat-resistant white organoclay by grinding.

  Therefore, the heat-resistant and easily dispersible organic clay according to the present invention is a silane obtained by dissolving a silane compound directly or in advance in an organic solvent such as methanol, ethanol or acetone in a semi-dry organic clay containing cristobalite. A heat-resistant organoclay can be obtained by adding a system compound, mixing, drying, and pulverizing.

Furthermore, by adding, mixing, drying and pulverizing the silane compound to the semi-dried organic clay containing cristobalite, directly, or adding the silane compound previously dissolved in an organic solvent such as methanol, ethanol and acetone. Dispersibility of silane compound-treated organoclays in organic systems such as resins and organic solvents improves particle size and reduces heat-resistant and easily dispersible organoclays. Organic solvent rheology control agent, resin A number of very excellent effects can be obtained, for example, the application of the functional filler can be greatly expanded.

  The present invention will be described in detail based on an embodiment of the invention shown below.

  In practicing the present invention, first, clay containing cristobalite as a raw material is sufficiently peeled and dispersed in water by a conventional method, and then the organic cation dissolved in water or alcohol is reduced to 0 to the cation exchange capacity of the clay. Organic clay in which organic cations are adsorbed on the clay surface by adding 5 to 2.0 times the amount and ion exchange of sodium ions and organic cations adsorbed on the clay crystal surface, and the crystal surface is hydrophobic Is generated. Next, this cristobalite-containing organic clay is washed and dehydrated, residual sodium ions and moisture are removed, and the resulting semi-dried organic clay is dissolved in an organic solvent such as methanol, ethanol or acetone. The compound is mixed with 0.01 to 50.0 wt% of the solid content of the organic clay, mixed, dried, and pulverized, so that the hydroxyl group and clay crystal of cristobalite are fixed and contained on the surface of the clay crystal. Silane coupling is reactively fixed to the hydroxyl group present on the end face to produce heat-resistant white easily dispersible bentonite organoclay.

  In the present invention, the above-mentioned amount of the organic cation and the silane compound are directly added to the clay aqueous dispersion containing cristobalite as a raw material, or alcohol such as methanol, ethanol, isopropyl alcohol, or acetone. A similar heat-resistant and easily dispersible organic clay can be obtained by adding, mixing, drying and pulverizing a silane compound dissolved in such an organic solvent.

  Here, the clay that can be used in the present invention is an organic clay containing cristobalite, in addition to smectite clay such as montmorillonite, beidellite, hectorite, saponite, stevensite, soconite, nontronite, vermiculite, halloysite, Natural and synthetic clays such as swellable mica and mixtures thereof. Cristobalite is naturally contained in a state of being fixed on the surface of the clay crystal, and cannot be separated from the clay even by a wet classification treatment with water tank.

  In this invention, the silane compound is reacted with cristobalite existing on the surface of the organic clay crystal by adding the silane compound to the organic clay containing cristobalite and mixing the silane compound. In addition to preventing deterioration of the quaternary ammonium adsorbed on the crystal surface due to heat, the silane compound also reacts with the end surface of the organic clay crystal to impart easy dispersion performance to the heat-resistant white organic clay of the organic clay. Can do.

  That is, after washing and dehydration to remove residual sodium ion residual cations and moisture, the obtained semi-dried organoclay is directly mixed with a silane compound, or alcohol such as methanol, ethanol, isopropyl alcohol, or acetone. The silane compound dissolved in such an organic solvent is added in an amount of 0.01 to 50.0% by weight based on the solid content of the organic clay, mixed, dried and pulverized to obtain a silane compound treated organoclay.

Moreover, as a silane type compound which can be used for this invention, general formula [YSiX3]
Y is a hydrocarbon group having 1 to 25 carbon atoms. Examples of the organic functional group having a hydrocarbon group having 1 to 25 carbon atoms and a locating group include a vinyl group, a chloro group, an amino group, an amide group, a carboxyl group, a hydroxyl group, a mercapto group, an epoxy group, and a nitro group. Nitroso group, nitrile group, netacryloxy group, phenyl group and the like. In particular, a silane compound added with a phenyl group is effective for improving heat resistance. X is a hydrolyzable group or a hydroxyl group, for example, a chloro group, an alkoxy group or a hydroxyl group.

  And in this invention, the addition amount of the said silane type compound is 0.01-50.0 weight% with respect to organoclay, Preferably, about 0.1-15.0 weight% is desirable. If it is 0.01% by weight or less, the heat resistance and dispersibility of the organoclay are not changed, and if it is 50.0% by weight or more, the heat resistance and dispersibility are adversely decreased.

  Of course, in the present invention, when a silane compound is added alone to a semi-dry organic clay containing no semi-dry cristobalite and mixed, heat resistance cannot be obtained. Easy dispersion performance can be obtained.

  Examples of the organic cation that can be used in the present invention include organic cations composed of a quaternary ammonium salt, a phosphonium salt, a sulfonium salt, and a mixture thereof.

  Quaternary ammonium salts include benzyltrialkylammonium ions such as benzyltrimethylammonium, benzyltriethylammonium, benzyltributylammonium, benzyldimethyldodecylammonium, benzyldimethyloctadecylammonium, benzalkonium, trimethyloctylammonium, trimethyldodecylammonium, trimethyl. Alkyltrimethylammonium ions such as octadecylammonium, dimethyldialkylammonium ions such as dimethyldioctylammonium, dimethyldidodecylammonium and dimethyldioctadecylammonium, and trialkylmethylammonium ions such as trioctylmethylammonium and tridodecylmethylammonium. , Benzethonium ion having two benzene ring.

[Example 1]
Montmorillonite containing cristobalite (manufactured by Hojun Co., Ltd., Bengel FW, its X-ray chart is shown in FIG. 1) A) Cation exchange capacity of montmorillonite (94 meq 76.6 meq / 100 g in a 2.0 wt% aqueous dispersion. Dimethyldioctadecylammonium (solid content concentration 76.395.0% by weight) of 1.4 times the amount of) was added, mixed, washed and dehydrated to produce a semi-dry organic clay. Its water content was 59.272.9% by weight. To this semi-dried organic clay, phenyltrihexyltrimeethoxysilane (HTS-M) (manufactured by Chisso Shin-Etsu Chemical Co., Ltd., KBE-103) is added in an amount of 0.5% by weight to the solid content of the organic clay. 0.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt% diluted with 10 times the amount of methanol, added, mixed, then dried and ground to phenyltriethoxysilane hexyltri A methoxysilane-treated organoclay (an X-ray chart of phenyltriethoxysilane treated with 0% by weight is shown in FIG. 2) was prepared.

[Example 2]
Montmorillonite containing cristobalite (manufactured by Hojun Co., Ltd., Bengel FW) in a 2.0% by weight concentration aqueous dispersion of dimethylstearylbenzylammonium (solid) 1.25 times the cation exchange capacity (76.6 meq / 100 g) of montmorillonite A semi-dried organoclay after washing and dehydration was prepared by adding, mixing, washing and dehydrating. Its water content was 84.1% by weight. Phenyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-103) was added to this organic clay with respect to the solid content of the organic clay, 0% by weight, 1.0% by weight, 3.0% by weight, 5.0%. Weight% and 8.0 weight% were diluted with 10 times the amount of methanol, added and mixed, then dried and ground to prepare phenyltriethoxysilane-treated organoclay.

[Comparative Example 1]
Montmorillonite containing no cristobalite (Hogel Co., Ltd., Bengel A, the X-ray chart of which is shown in FIG. 3) of montmorillonite cation exchange capacity (94 meq / 100 g) in a 2.0 wt% aqueous dispersion. A 25-fold amount of dimethyldioctadecylammonium (solid content concentration: 95.0% by weight) was added, mixed, washed, and semi-dried organoclay after dehydration was prepared. Its water content was 51.4% by weight. Phenyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-103) was added to this organic clay with respect to the solid content of the organic clay, 0% by weight, 1.0% by weight, 3.0% by weight, 5.0%. % And 8.0% by weight diluted with 10 times the amount of methanol, added, mixed, then dried and crushed and treated with phenyltriethoxysilane treated organoclay (Fig. 4 shows phenyltriethoxysilane treated with 0% by weight). An X-ray chart is shown.).

[Comparative Example 2]
To montmorillonite containing no cristobalite (Hogel Co., Ltd., Bengel 2A). After adding 1.25% dimethylstearylbenzylammonium (solid content concentration: 76.3% by weight) cation exchange capacity (94 meq / 100 g) of montmorillonite to a 0% by weight aqueous dispersion, mixing, washing, and dehydration A semi-dry organic clay was prepared. Its water content was 68.8% by weight. Phenyltriethoxysilane (KBE-103) ((Shin-Etsu Chemical Co., Ltd.)) was added to this organoclay with respect to the solid content of the organoclay, 0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt% and 8.0 wt% were diluted with 10 times the amount of methanol, added and mixed, then dried and ground to prepare phenyltriethoxysilane-treated organoclay.

〔Evaluation methods〕
Using the organic clay containing cristobalite prepared in the examples and the organic clay not containing cristobalite of the comparative example, heating at 250 ° C. for 5 minutes and 30 minutes in an electric furnace in an air atmosphere, and then cooling for 1 minute. Then, the heating was repeated again at 250 ° C. for 5 minutes, and the hunter whiteness of the organic clay before and after the heat treatment for 60 minutes in total and the decrease rate thereof were determined based on the following formula 1. The results are shown in Table 1.

  As can be seen from Table 1, the organoclay containing cristobalite of the example is a hunter white after heat treatment as the added weight of the silane compound is increased as compared with the organoclay not containing cristobalite of the comparative example. The degree of brightness was high, the rate of decrease in whiteness was low, and the influence of discoloration due to heat could be suppressed.

It is an X-ray chart of montmorillonite containing cristobalite. It is an X-ray chart of phenyltriethoxysilane treated with 0% by weight of phenyltriethoxysilane-treated organoclay. It is an X-ray chart of montmorillonite which does not contain cristobalite. It is an X-ray chart of phenyltriethoxysilane treated with 0% by weight of phenyltriethoxysilane-treated organoclay.

Claims (5)

  A heat-resistant white easily dispersible organic clay characterized in that cristobalite contained in an organic clay and a silane compound are reacted to fix the silane compound on the crystal interlayer crystal surface and end face of the organic clay. Silane compounds are represented by the following general formula
[YSiX3]
[Wherein Y is a hydrocarbon group having 1 to 25 carbon atoms, an organic functional group composed of a hydrocarbon group having 1 to 25 carbon atoms and an anchoring group, and X is a hydrolyzable group or a hydroxyl group] The heat-resistant white easily dispersible organoclay according to claim 1, comprising the group of   Silane compound directly into semi-dry state organic clay containing semi-dry state cristobalite, or silane compound dissolved in organic solvent such as methanol, ethanol, acetone in advance and mixed, dried, A method for producing a heat-resistant white easily dispersible organic clay characterized by pulverizing.   Heat-resistant and easy-dispersion characterized by adding an organic cation and a silane compound directly to a clay water dispersion containing cristobalite, or by adding a silane compound previously dissolved in an organic solvent, mixing, drying, and grinding. Method for producing organic organoclay.   The heat-resistant white easily dispersible organoclay according to claim 3 or 4, wherein the addition of the silane compound is 0.01 to 50.0% by weight with respect to the organoclay. Manufacturing method.

Images