JPS5869771A - Graphite fluoride formed body and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorinated graphite molded product which has extremely high moldability and excellent mixing and dispersibility with other substances, and a method for producing the same.

Fluorinated graphite is a layered inorganic polymer compound in which fluorine atoms and carbon atoms are bonded in a hexagonal network, and its properties include low surface energy, lubricity, and heat resistance.
The bond between the two is strong and completely chemically stable, but under certain special conditions, the defluorination reaction will proceed, and these characteristics can be used to create solid lubricants, antifouling agents, lubricants, and water repellents. oil repellent,
It is being widely applied industrially, such as as battery active materials.

However, due to its unusually low surface energy, fluorinated graphite has extremely poor formability compared to other fluorine-based substances or other layered compounds, and also has the drawback of considerably poor mixing and dispersibility with other substances. In the development of applications, many efforts have been made to improve the above properties.

For example, in the invention described in JP-A-50-70295, fluorinated graphite and tetrafluoroethylene are reacted to form thread-like p'ryg between fluorinated graphite particles, thereby imparting moldability. Attempts are being made. 4I) In the invention described in JP-A No. 49-116462, fluorinated graphite is coated with a caking substance such as a wax or an oil in order to improve the stability of the coating on a lubricated surface. In the invention described in JP-A-47-45665, silica,
The dispersibility of graphite fluoride is improved by adding colloidal oxides such as alumina.

However, these methods are intended to improve the formability and dispersibility of graphite heptafluoride through addition of other substances or mere coexistence, and are difficult to accept as a more reliable and essential method, and their effects are difficult to obtain. It is also not fusion.

That is, in the method described in %Kaimei No. 50-70295, in order to blend fluorinated graphite with PTFgK, TFE is usually used.
P'I' obtained by emulsion polymerization of (tetrafluoroethylene)
FE aqueous dispersion is used, but since graphite fluoride has extremely high water repellency, it is necessary to suspend graphite fluoride in an organic solvent with a strong affinity for water and add it in advance. In order to sufficiently wet K, a large amount of organic solvent is required, causing coagulation of PTWE particles and large #! A uniform powder mixture cannot be obtained due to the formation of lumps. Furthermore, this large coagulum is highly sticky (and difficult to crush), and if it is compression molded as it is, the pressure is not applied uniformly, which tends to cause internal distortion, making it impossible to obtain a good molded product. Ta.

In addition, in the method described in JP-A-9-116462, a caking substance such as butterfly or wax is coated on the surface of fluorinated graphite particles by mere physical forces such as so-called adsorption and adhesion. In various usage modes,
It does not necessarily provide a stable coating, and furthermore, it has the disadvantage that uniform coating is difficult.

Furthermore, in the case of such a method, it is almost impossible to minimize the amount of caking substance on the fluorinated graphite and coat it uniformly in order to fully exhibit the characteristics of the fluorinated graphite. It is.

Furthermore, the method described in JP-A No. 47-45665 uses a dispersant such as colloidal silica to improve dispersibility, but due to its structure, it cannot be used as a molded product. There is an upper limit to the content of fluorinated graphite, and it can only be contained up to 60 degrees FSS at most, making it impossible to effectively utilize the unique characteristics of fluorinated graphite derived from surface energy. It is something.

In view of the above, the present inventors have conducted repeated research and have developed graphite heptadide (hereinafter referred to as MC) treated by applying the so-called micro-encapsulation technique (coating treatment with a polymer will be referred to as this for convenience). The present invention was based on the discovery that fluorinated graphite (fluorinated graphite) has excellent moldability and dispersibility.

That is, the purpose of the present invention is to obtain a uniform molded body of fluorinated graphite with excellent film stability, and this purpose is to obtain a uniform molded body of graphite fluoride with excellent film stability, and this purpose is to obtain a molded article of graphite fluoride that is microencapsulated by graft bonding with the vinyl resin of the present invention and resin. This is achieved by a fluorinated graphite molded product formed by pressure molding and a method for producing the same.

The fluorinated graphite used in the present invention is (CF)n.

((4F) In addition to what is represented by n, it also includes mixtures thereof in any proportion.

The fluorinated graphite of the present invention is microencapsulated by the graft bonding of vinyl resin, and unlike simple adsorption or adhesion, the wrinkle graft bond can be separated by solvent extraction. It is bonded to the graphite heptadide surface in a bonding form that is as strong as possible, resulting in a uniform coating. The resin content can take any value, but in order to improve the dispersibility, it is necessary to have at least α5 weight tSv4 degrees, and there is no particular upper limit, but in order to exhibit the physical properties of graphite fluoride, it is necessary to It can be said that it is preferable to have it up to about iJichi. Therefore, even with a small amount of resin, the dispersibility for various resins is good. Such MC fluorinated graphite can be molded as it is, but in the present invention, by adding a resin to it, the MC fluorinated graphite and the resin are compatible with each other, so that heating and pressure molding can be further improved. It is easy to process, has extremely good workability, and can also have a large degree of arc. Unlike the Me ratio, various resins can be selected for the resin added later.
For example, polymethyl methacrylate, phenol resin, acetal resin, human BS resin, etc. can be appropriately selected and used depending on the purpose. In this case, there is no particular upper limit for the amount of resin to be added, but in order to bring out the performance of fluorinated graphite, it is recommended that the mixture of graft w fat and later added resin be added to fluorinated graphite for up to 100 seconds. I can say that.

The fluorinated graphite of the present invention can be used even with a small amount of resin, and
i! Since it is tightly coated, the characteristics of fluorinated graphite can be maximized, and its uses are further expanded. Note that the vinyl resin coating in the present invention is not limited to one in which the fluorinated graphite is completely covered, but also includes one in which the fluorinated graphite surface is partially exposed.

Next, a method for manufacturing the molded article of the present invention will be explained.

First, in a water-organic solvent mixed system or a water-surfactant mixed system, fluorinated graphite powder and a vinyl monocap are dispersed,
A polymerization reaction is carried out in the presence of a water-soluble polymerization initiator, and microcapsules are formed using a monomer of fluorinated graphite.

The organic solvent used here may be any water-bathable organic solvent, such as methyl alcohol, ethyl alcohol, etc.
Various alcohols such as alcohol, ketones such as acetone, ethers, and amines are used. It may also be a mixed system.

On the other hand, the vinyl monocap for forming the polymer coating the fluorinated graphite may be any material that can undergo radical polymerization or radical copolymerization, such as acrylic acid, methacrylic acid, acrylates, methacrylates, etc. Acid acid, acrylic ester, methacrylic ester, acrylonitrile, N-
methylol acrylamide, vinyl chloride, vinyl acetate,
A monomer having a vinyl group such as styrene or cyhinylbenzene is used.

Examples of water-bathable polymerization initiators include chlorine dioxide, aqueous acid solution, bisulfite solution, potassium persulfate, azobiscyanovaleric acid, and V-50 (2,2'-7zobis(2-amidinopropane)-dihydrohydrochloride). chloride, Wako strips), etc. are used.

In order to suitably carry out the present invention, 1 to 100 parts by weight of an organic solvent, 1 to 50 parts by weight of a surfactant, 1 to 100 parts by weight of fluorinated graphite, and a vinyl compound a1 in 100 parts by weight of water are used.
~100 parts by weight are added and thoroughly stirred and dispersed, and a polymerization initiator is added to the suspension thus obtained and stirred well. The amount of the polymerization initiator to be used is sufficient in the range of α01 to 20% by weight based on the vinyl single lid. The polymerization reaction of the present invention can be carried out at room temperature, but if it is desired to shorten the polymerization time, it may be heated to about 70C. According to the present invention, a high polymerization rate can be obtained with a short polymerization time of 1 to 5 hours.

After the polymerization reaction is completed, the slurry of fluorinated graphite is separated, thoroughly washed with water, and the residue is dried.

By adding resin to the fluorinated graphite treated with MC with 5 to 50% by weight of vinyl resin and applying pressure coloring, a fluorinated graphite molded body can be easily obtained. The molding temperature varies depending on the vinyl monomer used and the resin added later, but it is usually 100 to 250°C, and the molding pressure is 150°C.
~450~/12 is sufficient.

In the present invention, microcapsules can be formed with an extremely small amount of resin, so it can be molded to a desired size using the known 71 method, and products containing a very large amount of fluorinated graphite can be molded, so the fluorinated graphite powder itself can be molded. A nearly continuous film can also be obtained.

In this way, the MC-formed fluorinated graphite molded article of the present invention can be manufactured into a molded article made almost entirely of fluorinated graphite itself, and can also be freely adapted to complex shapes. Its performance far exceeds that of its predecessor.

In addition, if you want to expose the fluorinated graphite layer on the surface of the molded object and make the characteristics of fluorinated graphite stronger, you can remove the resin by grinding the surface of this molded object, or peel off the surface resin by solvent treatment. You can also do it.

Since the molded article according to the present invention can fully exhibit the characteristics of fluorinated graphite, it can be used in all the applications in which fluorinated graphite is conventionally used, such as bearing materials, electrode materials, lubricating materials, and dendoma dispersion. When molded bodies, lubricants, etc. are crushed, molded bodies containing fluorinated graphite to a degree of l1i6VB, which greatly enhances the strength of lubricants, battery active materials (propagating materials), water-retaining materials, etc., are required. It can be applied to fields where pollution, moisture, and oil are extremely averse, by reducing the amount of added resin.

Furthermore, it goes without saying that various additives can be added to the molded article of the present invention depending on its use.

Next, examples of the present invention will be given and explained in more detail.

Production of MC fluorinated graphite Production example 1 A three-bottle flask with a capacity of 1 was placed in a constant temperature water bath maintained at 60°C, and 20 mL of ethyl alcohol and 280 d of water were added.
Add 100 t of heptadated black @ (CF)n (300 mesh after grinding with a jet mill, the micrograph is shown in Figure 1), and 25 f of methyl methacrylate, and while stirring and mixing, Polymerization was carried out by adding 20 mm of an aqueous solution of 6-thiosulfite. The pH at this time is about 2. After 4 hours had passed since the addition of the sulfite aqueous solution, the reaction product was separated, thoroughly washed with water, and vacuum-dried at 80°C.

The weight of this material was 117.8 f, and as is clear from the micrograph shown in Figure 2, the presence of fluorinated graphite or polymer alone was not introduced, and the hepta-nitride graphite was well coated with polymer, and C there was. In addition, after extracting this product with benzene for 48 hours, the extract and benzene-free f#h
The infrared absorption spectra of
I got the pattern shown in the figure. This confirmed that the extract was a homopolymer of polymethyl methacrylate, and that the benzene fraction also matched the spectrum of polymethyl methacrylate. From these results, it was confirmed that polymethyl methacrylate was graft-bonded to the surface of fluorinated graphite.

Historically, the content of polymethyl methacrylate was 15.111 Ljt- from its weight loss by thermogravimetric analysis (TGA).
(Hereinafter, in the production examples, grafting and polymer content were confirmed by the same means.)

Production Example-2 A three-bottle flask containing 1 was immersed in a constant temperature water bath maintained at 60°C, and ethyl alcohol: I-150-1 water 530-
Add graphite heptadide ((4F)n i OOf (pulverized with a jet mill, 250 mesh passes, shown in the micrograph in Figure 3), and methyl methacrylate 509, and while stirring, add 20 m of a 6qb sulfite aqueous solution. The pH at this time was approximately 2. Three hours after the addition of the sulfurous acid aqueous solution, the reaction product was separated, thoroughly washed with water at ℃, and then dried under vacuum at 80℃. A microscopic photograph of this material is shown in Fig. 4.

In this way, the inclusion of polymethyl methacrylate 419.
124.7f of 8-fold it'-dried product was obtained.

Production Example 3 Immerse each three-bottle flask in a constant temperature water bath at 60°C, and add 200 d of methyl alcohol, 285 d of water, 100 f of graphite fluoride (CIF), and 20 d of methyl acrylate.
9 was added, and while stirring, a 6-thiosulfite aqueous solution 15- was added to carry out polymerization.

Four hours after the addition of the sulfite aqueous solution, the reaction product was separated, thoroughly washed with water, and then vacuum-dried at 70°C. In this way, 11 tsr of a dry product with a polymethyl acrylate content of 1 (18% by weight) was obtained.

Production Example 4 A three-capacity flask was immersed in a constant temperature water bath at 60°C, and 200 ml of ethyl alcohol was added. Water 280-, fluorinated graphite (CF) n 100 f, acrylonitrile 30
Add t and stir until V-50 (Wako Tsumugi Co., Ltd.) 10
A water-soluble enemy 20- was added and polymerization was carried out. Three hours after the addition of the VSO aqueous solution, the reaction product was separated, thoroughly washed with water, and then vacuum-dried at 80°C. In this case, the content of polyacrylonitrile is 19.5% by weight.
A dried product of 1259f was obtained.

Production Example 5 A 16-capacity three-bottle flask was immersed in a constant temperature water bath at 60°C, and 20 ml of ethyl alcohol, 280 t of water, 100 t of graphite heptadide (aF), and 15 t of methyl methacrylate were added.
15 tons of t1 styrene was added, and while stirring, 20 sd of a 6% sulfite aqueous solution was added to carry out polymerization. After 6 hours had passed since the addition of the sulfite aqueous solution, the reaction product was separated, thoroughly washed with water, and dried under vacuum at 80°C. In this way, 122.51 ml of a dry product with a copolymer content of 1 & 8 weight was obtained.

Production Example 6 Add 200% acetone to a C1LC1L volumetric flask at room temperature.
mg, ・Water 280- and graphite heptadide ((?F)n100
91 Medel methacrylic acid 10F was added, and while stirring and mixing, a 6-thiosulfite aqueous solution 10- was added to carry out polymerization. After 5 hours had passed since the addition of the sulfite aqueous solution, the reaction product was
It was separated, thoroughly washed with water, and vacuum dried at 70°C. In this way, the content of poly:methacrylic methyl was 4.8.
A total of 1,051 dry products were obtained.

Production Example 7 Polymerization was carried out under the same conditions as Production Example 6, except that the addition chamber for dense methyl methacrylate was 5 f and the time for 6 hours was used to produce a dried product 1 with a polymethacrylic ridge methyl content of 12 weight t/ktII. (I got lt2f.

Example 1 8 g of MO fluorinated graphite produced in Production Examples 1 to 7
Resin powders were dry mixed with the composition shown in Table 1, and 10% of each
Compression molding was carried out using a mold with a diameter of 50 ftt at a molding temperature of 180°C and a molding pressure of 250 cm and an edge of 10 n''. All of these had good moldability and no problem with deoxidation. These evaluation results are shown in Table 1.

Comparative Example 1 Untreated fluorinated graphite and resin powder having the composition shown in Table jg1 were dry mixed and compression molded in the same manner as in Example 1.

The results are shown in Table 1.

Practical Example 2 Dry mixing with MC fluorinated graphite AB8 resin, phenol resin, and acetal resin of Production Example 6, and gold noodle temperature 100 ~
A molded body was obtained by holding at 180° C. and a molding pressure of 15-0 to 200 Q/aIPK for 10 minutes. The pv value of these molded bodies (
The results are shown in Table 2.

Comparative Example 2 The youngest brother IIA ((!F)n was dry mixed with AB8 resin, phenol resin, and acetal resin, and the pv value and wear amount of the molded product prepared in the same manner as in Example 2 were the same as in Example 2. The results are shown in Table 2.

/'- ,,,−/−” /// Table 2

[Brief explanation of drawings]

Figures 1 and 2 are micrographs of untreated (CF)n and polymer-coated (CF)n of Production Example 1, and Figures 5 and 4.
The figure shows the untreated (CIF)n and polymer coated (CIF)n of Production Example 2.
(4F) A micrograph of n is shown. FIGS. 5 and 6 show infrared absorption spectrum patterns of the extract and benzene imprints obtained by the benzene extraction treatment of the product in Production Example 1. Agents 1) Akira Agent Hagiwara Death - Fang 1 figure P 3rd figure 111 1μ spear 2 figure soil 4 figure

Claims (2)

[Claims] (1) Both surfaces are grafted together with vinyl resin [
A graphite heptadide molded body made of graphite fluoride and resin. (2) In a water-organic solution mixing chamber or a water-surfactant system, disperse graphite fluoride and vinyl monomers capable of radical polymerization or radical copolymerization to initiate water-soluble polymerization. Polymerization is carried out in the presence of an agent [, the resulting resin graft bonded fluorinated graphite Kj! 1. A method for producing a fluorinated graphite molded article, which comprises adding a resin to a fluorinated graphite molded body to form a shadow.