JPS6239026B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention involves contacting a solid material with a liquid vinyl monomer in the form of vapor, or impregnating a solid material with a liquid vinyl monomer, and then removing excess vinyl monomer by evaporation or washing with a solvent to coat the surface of the solid material with the vinyl monomer. It relates to a method of adsorption followed by contact with gaseous sulfur dioxide and polymerization thereof without the use of a liquid medium. In recent years, composite materials of solid substances and polymers have been widely used in many fields as building materials and various materials, and have been gaining importance because they can be used as carriers for functional materials. Generally, when producing a composite material of a solid material and a polymer, the surface of the solid material undergoes a compositing process to form an interface between the matrix polymer and the solid material. The importance of this interface has been studied from various angles, and methods of modifying the physical and chemical structure of the surface of solid materials have already been attempted in order to obtain a desirable interface. For example, as a method for coating the surface of solid particles with a polymer without using a liquid medium, methods have been proposed in which vinyl monomers adsorbed on the surface of a solid material are polymerized by mechanochemical treatment or radiation irradiation, but none of them are effective. It has not been put into practical use because of its drawbacks such as low energy consumption and the need for special equipment. In addition, a method in which a radically polymerizable vinyl monomer supported on the surface of inorganic particles is brought into contact with gaseous sulfur dioxide in a gas phase (Japanese Unexamined Patent Application Publication No. 103978/1989) is also used to polymerize polymers that do not use a liquid medium. This is one of the methods for producing coated inorganic materials. However, in this method, the liquid vinyl monomer is directly supported on the inorganic substance, so
The amount of vinyl monomer attached to the surface of an inorganic substance is large, and when polymerization is carried out by contacting with sulfur dioxide, it is necessary to suspend them in a gas phase by shaking or blowing an air stream. Therefore, the particle size of the inorganic material used as a raw material is limited to a size that allows it to be suspended in the gas phase. In addition, since polymerization occurs preferentially on the surface of the inorganic material and almost no polymerization occurs anywhere else, this method has disadvantages such as low polymer yield, and is not necessarily a satisfactory method. The present inventor has conducted intensive research to improve this point and to develop a method that can efficiently obtain a polymer-coated solid material with simple operations. It has been discovered that the object can be achieved by adsorbing it and bringing it into contact with gaseous sulfur dioxide in a non-medium, and based on this finding, the present invention has been accomplished. That is, according to the present invention, when coating the surface of an inorganic or organic solid material with a polymer, the solid material and the liquid vinyl monomer are brought into contact as vapor, or the solid material is impregnated with the liquid vinyl monomer, and then the excess water is removed. Polymer-coated solid materials can be easily prepared by adsorbing the vinyl monomer onto the surface of the solid material by evaporating off the vinyl monomer or washing with a solvent, followed by polymerization by contacting with gaseous sulfur dioxide in a non-medium. can be obtained. To carry out the present invention preferably, a solid substance is placed in a sealable container, and after adsorbing a vinyl monomer that can be radically polymerized or copolymerized, gaseous sulfur dioxide is introduced, the container is sealed, and a predetermined temperature is maintained at a predetermined temperature. The vinyl monomer adsorbed on the solid may be polymerized over time. The solid substance used in the method of the present invention may be any substance as long as it has the function of adsorbing the vinyl monomer vapor used, but in particular an inorganic or organic solid substance with a polar solid surface and a large surface area is desirable. Examples of such materials include zeolite, molecular sieves, white carbon, silica gel, silicic anhydride, alumina, bentonite, activated clay, metahalosite,
Inorganic solid substances such as kaolin, mica, talc, carbon black, carbon fiber, graphite, or wood flour, purified cellulose, cellulose fiber, valve,
Examples include organic solid materials such as straw, silk, and wool. Furthermore, if the polymerization rate of the adsorbed vinyl monomer is slow and the polymerization rate is low, it is advantageous to use a solid material that has been previously treated with a transition metal compound in order to accelerate the polymerization. As such a transition metal compound, compounds such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, iron, zinc, zirconium, and niobium can be used. It is sufficient that the amount of these transition metal compounds added is 10% by weight or less based on the solid material in terms of metal content, but even more is acceptable. On the other hand, the vinyl monomer used in the method of the present invention is
A liquid vinyl monomer that can undergo radical polymerization or radical copolymerization, such as acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, acrylonitrile, vinyl acetate, styrene, divinylbenzene, etc. . In the method of the present invention, in order to adsorb these vinyl monomers onto the surface of a solid substance, for example, the vinyl monomer vapor is brought into contact with a solid substance that has been dried under reduced pressure in a reaction vessel, or the solid substance is impregnated with a liquid vinyl monomer, and then the solid substance is impregnated with liquid vinyl monomer. This is done by drying under reduced pressure to evaporate off excess vinyl monomer. It is also possible to adsorb the vinyl monomer onto the surface of the solid material by mixing the liquid vinyl monomer and the solid material and washing away the excess vinyl monomer with a non-polar solvent such as n-heptane. Further, in order to adsorb two or more types of liquid vinyl monomers, a mixed vinyl monomer may be used, or the main vinyl monomer may be adsorbed first, and then other co-vinyl monomers may be adsorbed in order. The solid material adsorbing the vinyl monomer in this way has 1
It is advantageous to subject the material to the next contacting step with sulfur dioxide while containing about 10% by weight of water. The amount of vinyl monomer used in the present invention is preferably in the range of 0.5 to 100 parts by weight per 100 parts by weight of the solid material, and in particular, solid materials supporting 3 to 50 parts by weight of polymer are suitable for industrial use and from a cost standpoint. Many of them are suitable in terms of performance. The amount of sulfur dioxide used in the present invention is preferably in the range of 0.01 to 100% by weight based on the vinyl monomer, but a larger amount may be used. In the present invention, this sulfur dioxide is introduced into a reaction vessel containing a solid substance adsorbed with vinyl monomer, and then the vessel is sealed and the vinyl monomer is polymerized. Polymerization is carried out by standing still, but if necessary, stirring or shaking may be used. According to the present invention, most of the adsorbed vinyl monomer is polymerized in a polymerization time of about 1 to 5 hours, and the solid substance is uniformly and efficiently produced by the polymer, and most of the produced polymer is extracted with the solvent. The coating is so strong that it will not be damaged. The polymer-coated solid substance obtained by the method of the present invention can be used as a carrier for functional materials, and can be molded as it is, so it can be suitably used as a molding material or a filling material. Furthermore, this method can be used as a surface treatment technique for pigments, etc., and is an extremely useful method industrially. Next, the present invention will be explained in more detail with reference to Examples. Example 1 Synthetic zeolite (Toyo Soda 100
Add 20.0g of methyl methacrylate (hereinafter abbreviated as MMA) and degas it at room temperature.
2.49g was introduced as vapor and adsorbed. Next, 1.80 g of sulfur dioxide was introduced into the reaction tube, the tube was sealed, and the tube was left in a constant temperature bath adjusted to 60.degree. C. for 3 hours. After the reaction,
After washing the reaction product with ethyl ether,
After drying under reduced pressure at ℃ for 20 hours, 21.2 g of PMMA-synthetic zeolite composite with good polymer coating was obtained. When this was subjected to differential thermal analysis (hereinafter abbreviated as DTA/TGA), exothermic peaks at 300°C and 369°C due to polymer decomposition and an accompanying weight loss were observed. Furthermore, when 2.0 g of this composite was immersed in 100 ml of 40% hydrofluoric acid solution, 0.10 g of the polymer remained in the solution without being decomposed. From this result, the polymerization rate was 42.6%, and the polymer content in the composition was 5.0%.
It was found that %. Example 2 In Example 1, using 20.0 g of synthetic zeolite containing 4.0% by weight of copper by copper sulfate treatment,
The mixture was brought into contact with 7.20 g of MMA vapor under reduced pressure to adsorb it, and the same operation as in Example 1 was carried out to obtain 27.1 g of a composite with good polymer coverage. complex
As a result of DTA/TGA and hydrofluoric acid treatment, the polymerization rate was
98.0%, and the polymer content in the composition was 25.7%. This composite powder was heated at a pressure of 200Kg/cm ² and a mold temperature of
The bending strength of the molded product obtained by compression molding at 180℃ is 480
Kg/cm ² , and the compressive strength was 1,320 Kg/cm ² . Example 3 Natural zeolite (manufactured in Futatsui, Akita Prefecture, 200 mesh or less) was placed in a pressure-resistant reaction tube, degassed at room temperature, and brought into contact with styrene vapor to adsorb 2.8 g of it. Next, 0.90 g of sulfur dioxide was introduced into the reaction tube, the tube was sealed, and the tube was left at room temperature for one day. After the reaction, the reaction product was dried under reduced pressure at 60° C. for 20 hours to obtain 22.78 g of a composite with good polymer coverage. complex
As a result of DTA/TGA and hydrofluoric acid treatment, the polymerization rate was
99.2%, and the polymer content in the composition was 12.2%. Example 4 The same procedure as in Example 1 was repeated using 20.0 g of ferric chloride treated solid material and various monomers. The results are shown in Table 1. When the composites thus obtained were observed under an electron microscope, it was found that the polymer efficiently coated the solid substance in each case.

[Table] Example 5 In place of the synthetic zeolite in Example 1, 20.0 g of 200 mesh aluminosilicate glass powder treated with a chromate-monosulfuric acid mixture was used to adsorb 4.2 g of MMA vapor. The same operation as above was carried out to obtain 24.0 g of a composite with a good degree of double coverage of the polymer on the glass powder. Complex DTA・
As a result of TGA and hydrofluoric acid treatment, the polymerization rate was 95.2%.
The polymer content in the composition was 16.7%. Example 6 20.0 g of Molecule Sieves (manufactured by Hanui Chemical Co., Ltd., model 13X) was placed in a pressure-resistant reaction tube, dried under reduced pressure at 200° C. for 1 hour, and 10.0 g of MMA was added for vacuum impregnation. Next, excess MMA was removed by evaporation, and then 0.9 g of sulfur dioxide was introduced into the reaction tube, which was sealed and left in a constant temperature bath adjusted to 60° C. for 3 hours. After the reaction, the reaction product was washed with ethyl ether and heated to 60°C.
The mixture was dried for 20 hours to obtain 23.0 g of PMMA-molecular sieves composite. When this was subjected to DTA/TGA, a weight loss of 13.0% and an accompanying exothermic peak were observed. Example 7 20.0 g of granular silica gel treated with ferric chloride (manufactured by Hanui Chemical, 10-40 mesh) was placed in a flask.
38.0 g of MMA was added and vacuum impregnated. Next, the contents were filtered, washed with 50 ml of n-heptane, placed in a pressure-resistant reaction tube, and degassed at room temperature. Next, 0.5 g of sulfur dioxide was introduced into the reaction tube, and the tube was sealed.
It was left in a constant temperature bath adjusted to ℃ for 3 hours. After the reaction,
After washing the reaction product with ethyl ether, heat at 60°C.
After drying for 20 hours, the PMMA-silica gel composite 25.2
I got g. As a result of applying this to DTA/TGA,
A weight loss of 20.6% and an accompanying exothermic peak were observed. Example 8 10 g of the complex obtained in Example 4 was weighed out and extracted using a Soxhlet extractor using benzene as a solvent for 100 hours. The results are shown in Table 2.

[Table] Comparative example The solid substance used in Example 4 was added to a solution of 10 g of PMMA dissolved in 100 g of benzene.
After uniformly dispersing the mixture using a stirrer, a polymer coating was obtained by removing benzene while heating and degassing. 10g of this was weighed out and extracted with benzene according to Example 6. The results are shown in Table 3.

【table】

Claims (1)

[Scope of Claims] 1. When coating the surface of an inorganic or organic solid substance with a polymer, the solid substance is brought into contact with a liquid vinyl monomer in the form of vapor to adsorb the vinyl monomer onto the solid substance surface, and then in a non-medium. A method characterized in that the polymerization is carried out in contact with gaseous sulfur dioxide. 2. When coating the surface of an inorganic or organic solid material with a polymer, the solid material is impregnated with a liquid vinyl monomer, and then the excess vinyl monomer is removed by evaporation or washed with a solvent to adsorb the vinyl monomer onto the surface of the solid material. , followed by polymerization by contacting with gaseous sulfur dioxide in a non-medium.