JPH0211651A - Fluorocarbon resin composition - 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 <Industrial Application Field> The present invention relates to a fluororesin having high compression resistance in which a filler surface-treated with a fluorine-containing silane coupling agent is dispersed.

<Conventional technology and its problems> Conventional fluororesins are currently used as corrosion-resistant materials and non-adhesive coatings for chemical plants due to their excellent water repellency, oil repellency, non-adhesive properties, low friction properties, chemical resistance, etc. It is used in a wide range of fields, including various household items and mechanical parts that require low friction, such as bearings.

In recent years, efforts have been made to improve the performance of parts that carry high loads, such as bearings and sliding parts, and when conventional fluororesins are used in such applications, the compressive properties are poor.

There is a problem that mechanical properties such as wear resistance are insufficient.

To solve this problem, fluororesins filled with various inorganic fillers have been developed, but although they improve wear resistance, they have the disadvantage that compression resistance does not improve much. This is due to poor adhesion to the inorganic material.

<Knowledge related to solving the problems> As a result of intensive research to solve the above problems, it was found that fluororesin filled with inorganic filler whose surface was treated with a specific fluorine-containing silane coupling agent I found that it solved the problem.

<Structure of the invention> The present invention is based on the general formula C, F, , 5o2NR" Ctl
□CH2Ct(2SiX.

(In the formula, R1 is H or C1 to C, an alkyl group, and X is -C
Provided is a fluororesin composition characterized in that an inorganic filler treated with a fluorine-containing silane coupling agent represented by Q, -Br, -0CH,, -QC,H, is dispersed therein.

Preferably, the inorganic filler is treated with 0.1 to 20% by weight of a fluorine-containing silane coupling agent.

The above-mentioned fluorine-containing silane coupling agent exhibits water repellency, oil repellency, and non-adhesiveness due to the perfluoroalkyl group, while the trihalogenosilyl group and trialkoxysilyl group react with water to become a trihydroxysilyl group, and further This has the property of forming dehydration, condensation, hydrogen bonding, etc., and bonding with hydroxyl groups present on the surface of the inorganic material.

In addition, the sulfonamide bond provides thermal and chemical stability compared to carboxylic acid ester and carboxylic acid amide type compounds, and a high yield of the hydrosilylation reaction during its synthesis. Furthermore, the alkyl group bonded to the nitrogen atom increases compatibility with solvents. In the above general formula, the alkyl group of R1 may be either straight chain or branched chain. Moreover, an ether bond may exist in the middle.

The above-mentioned fluorine-containing silane coupling agent is produced as follows.

C, Fl, SO□NR”CH, CH, =CH, ([1)
N-allyl-N-alkylperfluorooctylsulfonamide represented by the general formula (wherein R1 is the same as above) and trihalogenosilane represented by the general formula HSiX3 (II) (wherein X is chlorine or bromine). is reacted in the presence of an additional catalyst and, if necessary, the product is further reacted with methanol or ethanol.

As described above, the fluorine-containing silane coupling agent in the present invention has a trihalogenosilyl group.

and a trialkoxysilyl group reacts with water to become a trihydroxysilyl group, which bonds with a hydroxyl group present on the surface of the inorganic material through dehydration condensation or hydrogen bonding, or does not have a hydroxyl group on the surface. It strongly adsorbs inorganic fillers, and at the same time, the perfluoroalkyl groups arranged on the surface increase the adhesion to the fluororesin.
) The alkyl group and sulfonyl group bonded to the nitrogen atom in the formula increase the compatibility with the solvent and improve the dispersibility of the filler in the solvent.

The inorganic filler used in the present invention is not particularly limited, but specific examples include glass fiber, glass beads, alumina, and Grapheye 1.

Examples include carbon fiber, molybdenum disulfide, and metal powders such as bronze and buttons.

Furthermore, the fluororesin used in the present invention is not particularly limited, but specific examples include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, and hexafluoroethylene-hexafluoropropene. Polymers, tetrafluoroethylene-ethylene copolymers, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, chlorotrifluoroethylene-ethylene copolymers, and the like.

There are wet methods and dry methods for surface treatment of these inorganic fillers, and both can be applied to the present invention.

In the wet method, the above inorganic filler is added to a solution containing a fluorine-containing silane coupling agent represented by formula (1),
This is done by stirring.

The solvent used here is preferably an organic solvent such as a halogenated hydrocarbon, alcohol, or ether, and is anhydrous or, if necessary, added with a small amount of an aqueous solution of an amine or acid.

The amine used here may be any of primary amines, secondary amines, and tertiary amines, but primary amines are particularly effective.

In addition, as the acid used, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, oxalic acid, and toluenesulfonic acid can be used.

In the aqueous solution of these amines or acids, water hydrolyzes the trihalogenosilyl group or trialkoxysilyl group of the fluorine-containing silane coupling agent to form a trihydroxysilyl group, which dehydrates the hydroxyl group of the inorganic filler. It has a strong adsorption effect even on inorganic fillers that are condensed or do not have hydroxyl groups on the surface. Furthermore, the acid and amine serve as catalysts that promote this hydrolysis and dehydration condensation. The concentration of these amines or acids is 15% by weight or less, preferably 0.1% by weight.
~3 weight percent is suitable.

When treating inorganic fillers with these fluorine-containing silane coupling agent solutions, the treatment temperature varies depending on each solvent, but it is carried out in a temperature range from room temperature to the boiling point of the solvent,
After treatment, it is usually carried out by filtration, drying, or evaporation of the solvent. In the case of evaporation, the entire amount of the dissolved silane coupling agent adheres to the inorganic filler.

In addition, if an anhydrous solvent is used or the treatment is performed at room temperature, an aqueous solution of amine or acid may be added as necessary.
These inorganic fillers are heated at 0 to 95°C, preferably 60 to 80°C, or heated at 50-15°C without using a solution.
This is carried out by heating and drying at 0°C, preferably 80 to 130°C.

These treatments are necessary to more firmly bond the fluorine-containing silane coupling agent to the surface of the inorganic filler.

In the dry method, the inorganic powder is vigorously stirred at room temperature or while being heated, and the fluorine-containing silane coupling agent shown by formula (1) is added dropwise as it is or a solution of the fluorine-containing silane coupling agent in a solvent is added little by little. Can be executed.

In this case, the solvent and catalyst (amine, acid) mentioned in the wet method are also used.
etc. can be used similarly. The treated powder is heated again and the solvent is evaporated at the same time.

The bond between the fluorine-containing silane coupling agent and the inorganic filler can be strengthened.

The amount of the fluorine-containing silane coupling agent to be treated varies depending on the specific surface area of the inorganic filler, but is preferably from 0.1 to 20% by weight.

If it is less than 0.1% by weight, the adhesion to the fluororesin will not be sufficient, and if it is more than 20% by weight, no change in properties will be observed compared to less than 20% by weight.

The fluororesin used may be based on molding powder (powder for compression molding) or fine powder (powder for paste extrusion).1Usually, after filling with an inorganic filler, After preforming, it is fired and shaped.

<Specific disclosure of the invention> The present invention will be specifically described below with reference to Examples.

Example 1 50 g of glass fiber (diameter: about 3 μm, length: about 50 μm) and 500 g of liquid (containing 1% by weight of 10% dilute hydrochloric acid aqueous solution)
mG in an electric loss machine and mix vigorously for 10 minutes at room temperature.
Stirred. After the stirring was completed, the solvent was evaporated by heating to 100° C. to obtain glass fibers treated with a fluorine-containing silane coupling agent. This glass fiber was mixed with polytetrafluoroethylene (Teflon) powder at 50% by weight, compressed and preformed to 172φX10mm at 400kg/al, and then baked at 370°C for 1 hour.
A glass fiber filled Teflon resin was obtained.

The compressive strength, (speed 3 + am/win) and friction properties of the glass fiber-filled Teflon resin thus obtained were investigated. For the friction characteristics, a precious wood type abrasion tester was used. The results are shown in Table 1 together with Comparative Example 1.

Comparative Example 1 A molded test piece was made in the same manner as in Example 1 using a Teflon resin filled with glass fibers without surface treatment with a fluorine-containing silane coupling agent.

I conducted a test. The results are shown in Table 1 together with Example 1, and the two were compared.

Table *Measurement conditions: Compatible material 5LIS-27, sample size 256φ
×20φX 15 Q (mm), load 4 kg/c+
+r, speed 60 m/min, time 16 hrs, (break-in operation 30 m1n) Example 2 50 g of graphite was placed in an IQ Mitsuro flask equipped with a thermometer, a stirring device, and a reflux device, and the same as in Example 1 was added while stirring. Fluorine-containing silane coupling agent solution (
10% by weight) 100+++Q was added dropwise over 1 hour. After the dropwise addition was completed, the solvent was removed by heating to 100° C. to obtain a fluorine-containing silane coupling agent powder. Dispersion in Teflon resin and property tests were conducted in the same manner as in Example 1. The test results are shown in Table 2.

Comparative Example 2 Similar to Comparative Example 1, a characteristic test of Teflon resin in which untreated graphite was dispersed was conducted. The results are shown in Table 2.

Table 2 Procedural amendment 1.Displaying the matter

Claims (1)

[Claims] 1. General formula C_8F_1_7SO_2NR^1CH_2
CH_2CH_2SiX_3...(I) (In the formula, R^1 is H or C_1 to C_5 alkyl group, X is -Cl, -B
A fluororesin composition characterized in that an inorganic filler treated with a fluorine-containing silane coupling agent represented by r, -OCH_3, -OC_2H_5) is dispersed therein. 2. The fluororesin composition according to claim 1, wherein the fluorine-containing silane coupling agent is treated with 0.1 to 20% by weight of the compound.