JPH07106908B2 - Potassium titanate fiber and thermoplastic resin composition containing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to at least one kind of oxide having a fiber surface selected from the group consisting of oxides of silicon and oxides of aluminum, which is useful as a reinforcing material for thermoplastic resins. Covered with objects,
Further, a composition containing potassium titanate fibers treated with a silane coupling agent and a thermoplastic resin, and the fiber surface is coated with at least one oxide selected from the group consisting of oxides of silicon and oxides of aluminum. And a silane coupling agent and a thermoplastic resin.

Conventional Technology Potassium titanate fiber has a general formula of K ₂ O · nTiO ₂ (n = 2,4,
It is a whisker represented by 6), and has a reinforcing material, a heat insulating material,
It is an artificial mineral fiber whose application is being developed in a wide range of fields such as friction materials, ion exchange materials and adsorbents.

In recent years, its useful position is being reinforced especially as a reinforcing agent for thermoplastic resins. That is, a resin reinforced with potassium titanate fibers has small strength and dimensional anisotropy when molded, and has good surface smoothness. Further, when formed into a small molded product, the fluidity to the minute portion is better than that of other fiber-filled products.
However, in terms of mechanical strength, the fact is that the effective properties of potassium titanate fibers have not been fully utilized. That is, since the potassium titanate fiber is very bulky, it is difficult to uniformly disperse the fiber in the resin, and in order to uniformly disperse the fiber in the resin, it is necessary to increase the dispersing power of the kneader. However, in this case, the fibers are severely broken during kneading, and the aspect ratio (fiber length / fiber diameter) is reduced, and the reinforcing effect is reduced. To reduce fiber breakage,
If the dispersive power of the kneader is weakened, the dispersion of the fibers in the resin becomes insufficient and the expected reinforcing effect cannot be obtained.

Problems to be Solved by the Invention Thus, conventional potassium titanate fibers have a problem in dispersibility at the time of kneading with a resin, and are not preferable as a reinforcing material for a thermoplastic resin, and a new reinforcing material has been developed. Was wanted.

The present invention is a potassium titanate fiber excellent in dispersibility at the time of kneading with a thermoplastic resin, which does not have the drawbacks of conventional ones, and has small strength and dimensional anisotropy, and has good surface smoothness and minute parts. It is an object of the present invention to provide a thermoplastic resin composition which has fluidity to, and has high strength and high elastic modulus.

Means for Solving the Problems As a result of research to solve the above problems, the present inventors coated with at least one oxide selected from the group consisting of oxides of silicon and oxides of aluminum. After that, further treatment with a silane coupling agent markedly improves the dispersibility in the thermoplastic resin, and the thermoplastic resin reinforced with gallium titanate fibers subjected to this treatment has a more excellent strength and elastic modulus. The present invention has been completed and the present invention has been completed.

That is, the present invention relates to a resin-reinforcing titanic acid obtained by coating the fiber surface with at least one oxide selected from the group consisting of silicon oxides and aluminum oxides, and further treating it with a silane coupling agent. A potassium fiber and a thermoplastic resin composition containing the same are provided.

Hereinafter, the present invention will be described in detail. The potassium titanate fiber of the present invention is an aqueous slurry prepared by dispersing conventional potassium titanate fiber in water, and at least one selected from the group consisting of a water-soluble salt of silicon and a water-soluble salt of aluminum is added to the slurry. A water-soluble salt was added and neutralized to deposit at least one hydrated oxide selected from the group consisting of silicon hydrated oxide and aluminum hydrated oxide on the surface of potassium titanate fiber. After that, it is obtained by treating with a silane coupling agent after filtering, washing and drying. Since the oxides present on the surface of potassium titanate fibers are dried hydrated oxides, including the case where some or all of them are hydrated oxides, these oxides form the surface of potassium titanate fibers. A continuous film is preferable, but a discontinuous film may be used.
The surface treatment with these oxides may be carried out by using each of silicon oxide or aluminum oxide alone or by using a mixture of silicon and aluminum oxides.
In addition to at least one oxide selected from the group consisting of oxides of silicon and oxides of aluminum,
For example, titanium oxide or zinc oxide may be present on the fiber surface. The amount of at least one oxide selected from the group consisting of oxides of silicon and oxides of aluminum is 0.5 to 10% by weight based on potassium titanate fibers, calculated as SiO ₂ and Al ₂ O ₃ , respectively. It is preferably 1 to 5% by weight. When the treatment amount of the oxide is less than 0.5%, the effect of improving the dispersibility in the resin is insufficient, and when it is more than 10% by weight, not only the dispersibility deteriorates but also the hygroscopicity becomes high. Invite.

When the hydrated oxide of silicon is deposited on the surface of potassium titanate fiber, for example, potassium titanate fiber of 50 to
Disperse it in water to a concentration of 150 g / to make an aqueous slurry, add a water-soluble alkali metal silicate such as sodium silicate, and then neutralize it by adding an acid such as sulfuric acid, hydrochloric acid, nitric acid, acetic acid. Then, a hydrated oxide of silicon is deposited on the surface of the potassium titanate fiber.

In the case of depositing a hydrated oxide of aluminum, for example, an aqueous slurry of potassium titanate fibers prepared in the same manner as described above, a water-soluble aluminate such as sodium aluminate, an aluminum compound such as aluminum sulfate and aluminum chloride. And then neutralized to deposit a hydrated oxide of aluminum. At this time, when using a water-soluble aluminate as a raw material of a hydrated oxide of aluminum, when neutralizing with the above acid, when using an acidic aluminum compound such as aluminum sulfate or aluminum chloride Neutralize with an alkali such as sodium hydroxide, potassium hydroxide or lithium hydroxide.

Further, in the case of depositing oxides of silicon and aluminum, neutralization is performed by using a water-soluble alkali metal silicate such as sodium silicate and the acidic aluminum compound in combination, and potassium titanate fiber surface is formed. A method of depositing a hydrated oxide of silicon and aluminum or a composite thereof, and after adding a water-soluble alkali metal silicate and a water-soluble aluminate to an aqueous slurry of potassium titanate fibers, sulfuric acid, hydrochloric acid, nitric acid, There is a method of depositing a hydrated oxide of silicon and aluminum or a composite thereof by neutralizing with an acid such as acetic acid.

After the hydrated oxide is deposited, it is filtered and washed,
Dry at a temperature above 200 ° C. If the drying temperature is lower than 200 ° C., the water content of the hydrated oxide is high, and problems such as foaming and resin decomposition will occur when the hydrated oxide is combined with the thermoplastic resin. There is no particular problem if the drying temperature is 200 ° C or higher, but it is practically in the range of 200 ° C to 300 ° C.

The treatment with the silane coupling agent after coating with at least one oxide selected from the group consisting of silicon oxides and aluminum oxides is performed by a known method. The method of treating the surface treating agent includes a method of performing a treatment before the kneading with the thermoplastic resin and a method of adding the surface treating agent during the kneading with the thermoplastic resin. The effect of the surface treatment agent is greater in the method of applying.

Examples of the silane coupling agent that can be used in the present invention include γ-aminopropyltriethoxysilane and N-β.
Amino-based silane coupling agents such as-(aminoethyl) -γ-aminopropyl trimethoxysilane and γ-ureidopropyl triethoxysilane, γ-glycidoxypropyl trimethoxysilane, β- (3,4- Epoxycyclohexyl) ethyl-trimethoxysilane and other epoxy-based silane coupling agents, vinyl-trimethoxysilane, vinyl-triethoxysilane, vinyl-tris (2-methoxyethoxy) silane and other vinyl-based silane coupling agents, γ- A mercapto-based silane coupling agent such as mercaptopropyl / trimethoxysilane and an acrylic-based silane coupling agent such as γ-methacryloxypropyl / trimethoxysilane can be used.

The addition amount of the silane coupling agent is 0.0 with respect to 100 parts by weight of a composition comprising potassium titanate fibers and a thermoplastic resin.
About 2 to 2.0% by weight is preferable. That is, when the amount of the surface treatment agent added is less than 0.02% by weight, the effect of improving the mechanical strength is hardly seen, and when it exceeds 2.0% by weight, the effect is already saturated, and therefore more than that. There is no point in adding it. The shape of the potassium titanate fiber is preferably such that the average fiber length is 5 μm or more and the average aspect ratio (average fiber length / average fiber diameter) is 10 or more.

As the thermoplastic synthetic resin in the thermoplastic resin composition of the present invention, all synthetic resins exhibiting thermoplasticity can be used, but polybutylene terephthalate, polyethylene terephthalate, polyacetal, 6-nylon, 66-nylon, polyarylate. Engineering plastics such as polycarbonate, polyphenylene sulfide, polyether sulfone, and polyether ether ketone are preferably used.

Regarding the composition of the thermoplastic resin composition of the present invention, the thermoplastic resin is 95 to 50 parts by weight, preferably 90 to 60 parts by weight, and at least selected from the group consisting of oxides of silicon and oxides of aluminum. After coating with one oxide, the potassium titanate fiber of the present invention further treated with a silane coupling agent is 5 to 50 parts by weight, preferably 10 parts by weight.
The range is up to 40 parts by weight. If the amount of the thermoplastic resin is less than 50 parts by weight, the molding processability is deteriorated, which is not preferable, and if the amount of the potassium titanate fiber is less than 5 parts by weight, the effect of improving the strength is insufficient.

Considering the balance of cost and workability, the range of 10 to 40 parts by weight of the potassium titanate fiber is preferable.

In the thermoplastic resin composition of the present invention, one or two kinds of various additives such as a flame retardant, a heat stabilizer, a lubricant and the like are used depending on the use and purpose of the composition as long as the physical properties inherent to the composition are not adversely affected. The above can be added.

The thermoplastic resin composition according to the present invention obtained as described above has small anisotropy in strength and size, has good surface smoothness and fluidity to minute portions, and has high strength and high elasticity. Precision parts, that is, parts including thin parts with a wall thickness of 1 mm or less, small parts with a molding weight of about 10 g or less, or parts with sharp edges at the tip, such as various gears. It is suitable for manufacturing parts that require mechanical strength, such as cams, cams, pulleys, and shafts.

Hereinafter, the present invention will be described in more detail with reference to examples.
The following examples are given for illustrative purposes only and the scope of the invention is not limited thereby. In addition,
In the following, all parts are by weight unless otherwise specified.

Example 1. Potassium titanate fiber (manufactured by Titanium Industry Co., Ltd., HT-20)
0) After dispersing 5 kg in 50 water in a stainless steel container,
After adding 100 g / aluminum sulfate aqueous solution 1 as Al ₂ O ₃ , 1N-sodium hydroxide was added dropwise to adjust the pH to 7. 0.8% by weight after filtration, washing and drying at 250 ℃
Γ-aminopropyltriethoxysilane (manufactured by Nippon Unicar Co., Ltd., A-1100).

Comparative Example 1. The same potassium titanate fiber used in Example 1 was treated with 0.8% by weight of γ-aminopropyltriethoxysilane.

Example 2. Potassium titanate fiber (manufactured by Titanium Industry Co., Ltd., HT-30)
0) Disperse 5 kg in water in a stainless steel container 70,
As O ₂ 80 g / sodium silicate solution (SiO ₂ / Na ₂ O
= 1.0: molar ratio) 1.2, and then as Al ₂ O ₃ 10
0 g / 0.5 aluminum sulfate aqueous solution was added. After filtration, washing and drying at 300 ° C., a 1.2% by weight γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., A-187) treatment was applied.

Comparative Example 2. The same potassium titanate fiber used in Example 2 was subjected to 1.2% by weight of γ-glycidoxypropyltrimethoxysilane.

Example 3. Potassium titanate fiber (manufactured by Titanium Industry Co., Ltd., LS-20)
After dispersing 5 kg in 40 water in a stainless steel container,
After addition of 80 g / sodium silicate solution 2.0 as _2, dropping 3N- sulfate, the pH was adjusted to 6. Filtration,
After washing and drying at 250 ° C, 1.0% by weight of γ-glycidoxypropyltrimethoxysilane (Nippon Unicar Co., Ltd.)
Strain, A-187).

Comparative Example 3. The same potassium titanate fiber as used in Example 3 was subjected to 1.0 wt% γ-glycidoxypropyltrimethoxysilane.

Example 4. 20 parts of potassium titanate fiber obtained in Example 1 and 80 parts of nylon 66 resin (UBE nylon 2020B manufactured by Ube Industries, Ltd.)
A twin-screw extruder AS-30 manufactured by Nakatani Machine Co., Ltd. melted and kneaded at a temperature of 280 ° C. to obtain pellets.

Example 5 30 parts of potassium titanate fiber identical to Example 4 and Example 4.
70 parts of the same nylon 66 resin as described above was pelletized under the same conditions as in Example 4.

Comparative Example 4. 20 parts of potassium titanate fiber obtained in Comparative Example 1 and Examples
80 parts of the same nylon 66 resin as in 4. was pelletized under the same conditions as in Example 4.

Comparative Example 5. 30 parts of the same potassium titanate fiber as in Comparative Example 4 and Example 4.
70 parts of the same nylon resin as was pelletized under the same conditions as in Example 4.

Using a vacuum dryer, the pellets obtained in Example 4.5 and Comparative Example 4.5 were dried at 120 ° C. for 12 hours, and then injection-molded by Yamashiro Seiki Seisakusho SAV-30-30 injection molding machine. (Cylinder temperature 260 to 280 ° C., mold temperature 80 ° C.) to obtain a test piece for measuring tensile strength and bending strength. Table 1 shows the result of strength measurement during absolute drying. For comparison, this table also shows the physical properties of nylon 66 resin alone. (Comparative example
6.) As is clear from Table 1, the potassium titanate fiber coated with aluminum oxide and further subjected to the coupling treatment has higher strength and higher elastic modulus than the potassium titanate fiber simply subjected to the coupling treatment. is doing.

When a film was prepared from the pellets of Example 4 and Comparative Example 4 and observed with an optical microscope, many agglomerates having a particle size of 50 μm were observed in the film produced from the pellets of Comparative Example 4. In contrast, no such aggregate was observed in the film prepared from the pellets of Example 4. Since the average fiber length of each was 20 μm and there was no particular difference, it is considered that the difference in dispersibility in the resin appeared as the difference in reinforcing effect as shown in Table 1.

Example 6. 20 parts of potassium titanate fiber obtained in Example 2 and a polycarbonate resin (Teflon A-2500 manufactured by Idemitsu Petrochemical Co., Ltd.)
80 parts and 29 pieces by Nakatani Machinery's twin-screw extruder AS-30
It was melted at 0 ° C, kneaded and pelletized.

Example 7. 30 parts of the same potassium titanate fiber as in Example 6 and Example 6.
70 parts of the same polycarbonate resin as was pelletized under the same conditions as in Example 6.

Comparative Example 7. 20 parts of potassium titanate fibers obtained in Comparative Example 2 and Examples
80 parts of the same polycarbonate resin as in 6. were pelletized under the same conditions as in Example 6.

Comparative Example 8. 30 parts of the same potassium titanate fiber as in Comparative Example 7 and Example 6.
70 parts of the same polycarbonate resin as was pelletized under the same conditions as in Example 6.

The pellets obtained in Example 6.7. And Comparative Example 7.8. Were injection molded (cylinder temperature 290 ° C., mold temperature 90 ° C.) using a Yamashiro Seiki Seisakusho SAV-30-30 type injection molding machine, and tensile test pieces were used. A bending test piece was obtained. The test results are shown in Table 2. For comparison, this table also shows the physical properties of the polycarbonate resin alone. (Comparative example 9.) Example 8. 20 parts of the potassium titanate fiber obtained in Example 3 and 80 parts of polybutylene terephthalate resin (manufactured by Polyplastics, Duranex 2000) were mixed with a twin-screw extruder AS-30 manufactured by Nakatani Machine Co., Ltd. It was melted at 250 ° C, kneaded, and pelletized.

Example 9. 30 parts of potassium titanate fiber identical to Example 8 and Example 8.
70 parts of the same polybutylene terephthalate resin as described above were pelletized under the same conditions as in Example 8.

Comparative Example 10. 20 parts of potassium titanate fiber obtained in Comparative Example 3 and Examples
80 parts of the same polybutylene terephthalate resin as 8.
Pelletization was carried out under the same conditions as in Example 8.

Comparative Example 11. 30 parts of potassium titanate fiber identical to Comparative Example 10 and Example
70 parts of the same polybutylene terephthalate resin as in 8.
Pelletization was carried out under the same conditions as in Example 8.

The pellets obtained in Example 8.9. And Comparative Example 10.11. Were subjected to Yamashiro Seiki Seisakusho SAV-30-30 injection molding machine (cylinder temperature 250 ° C., mold temperature 70 ° C.) to obtain test pieces. The test results are shown in Table 3. For comparison, this table also shows the physical property values of the polybutylene terephthalate resin alone. (Comparative Example 12.) Effect of the Invention Since the potassium titanate fiber of the present invention is excellent in dispersibility in a resin, a molded article obtained by molding a thermoplastic resin composition containing the potassium titanate fiber has high strength and high elastic modulus. It is effective in precision mechanical parts such as gears, cams, pulleys and shafts that require high mechanical strength.

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Claims (3)

[Claims] 1. A potassium titanate characterized in that the fiber surface is coated with at least one oxide selected from the group consisting of silicon oxide and aluminum oxide, and further treated with a silane coupling agent. fiber. 2. A thermoplastic resin composition containing 95 to 50 parts by weight of a thermoplastic resin and 5 to 50 parts by weight of the potassium titanate fiber according to claim 1. 3. A potassium titanate fiber having a fiber surface coated with at least one oxide selected from the group consisting of silicon oxide and aluminum oxide, 5 to 50 parts by weight, and a thermoplastic resin, 95 to 50 parts by weight. A thermoplastic resin composition containing 0.02 to 2 parts by weight of a silane coupling agent per 100 parts by weight of the composition consisting of