JPH0675865B2 - Manufacturing method of resin compound containing alkali titanate fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a resin compound containing alkali titanate fiber such as potassium titanate or sodium titanate as a reinforcing material under excellent workability. The present invention relates to a method that can be efficiently manufactured.

[Prior Art] Alkali titanate fibers have good heat insulation, heat resistance, and chemical resistance and have excellent dispersibility, and therefore their applications are gradually expanding as compounds combined with various resins. .

By the way, as a method of supplying the reinforcing fibers when mixing the reinforcing fibers with the resin to produce a compound, a pre-blending method (mixing the reinforcing fibers and the resin in advance with a mixer, and then feeding them into the hopper mouth of the extruder) Method)
There is a side feed method (a method in which the resin is put into the resin supply port of the extruder and the reinforcing fiber is fed from the intermediate vent port of the extruder). When glass fiber or carbon fiber is used as the reinforcing fiber, The fiber-containing resin compound for reinforcement is obtained by the method described above.

[Problems to be Solved by the Invention] However, when an alkali titanate fiber is used as the reinforcing fiber, the fiber cannot be stably and quantitatively compounded into the resin by any of the above methods, and the compounding ratio is often used. There is a problem such as fluctuations in the distribution or poor dispersibility. The reason is that the alkali titanate fiber is very bulky and has poor fluidity, and the fiber is clogged in the hopper port or the vent port in the process of supplying the resin, and the supply state becomes unstable. , It is not possible to obtain stable quality resin compound. Therefore, conventionally, a special weight type feeder or vibrating type feeder has to be used for the purpose of smoothly supplying the fiber, and since the fiber is lightweight and easily scattered, dust collection is required due to environmental hygiene. There is also a problem of equipment burden such as installation of equipment is indispensable.

The present invention has been made by paying attention to such a situation, and the purpose thereof is to use alkali titanate fibers as reinforcing fibers in the resin without using a special supply device. It is intended to establish a method for producing a resin compound that can obtain a stable quantitative blending / dispersion state and can also prevent scattering of alkali titanate fibers.

[Means for Solving the Problems] The configuration of the method of the present invention that has achieved the above objects is
After forming the collapsible granules of alkali titanate fiber with a binder, the granules are kneaded with a resin to uniformly disperse the alkali titanate fibers in the resin while collapsing the granules. Is to have.

[Operation] As a result of various investigations by the present inventors to eliminate the drawback that the bulk specific gravity of the alkali titanate fiber is very small and the fluidity is poor as described above, as a result, the alkali titanate fiber is used as a suitable binder as described above. If it is made into a disintegratable granule by the above method, it becomes a lump and the handleability is improved. For example, the dischargeability from the hopper and the like is stable and there is no uneven distribution when dispersed in the resin. I learned that the problem of acid-alkali fiber scattering can be achieved all at once. Then, the granulated product thus obtained is kneaded with the resin, and the granulated product is disintegrated to disperse the alkali titanate fibers in the resin, whereby the fiber-containing resin compound can be produced extremely efficiently. . That is, this granulated product is obtained by joining and integrating bulky alkali titanate fibers with a binder as if they were lightly attached and solidified, and since they have a lump shape, scattering is prevented and fluidity is remarkably improved. As a result, even when compounded in the resin, there is no fear of causing a blockage accident in the hopper or the like, and the compounding ratio can be stably maintained. Moreover, since this granule easily disintegrates when kneaded with the resin,
The resulting resin compound has alkali titanate fibers uniformly dispersed therein.

Although various means can be adopted as a method for producing the disintegratable granule, the most common method is to put the alkali titanate fiber in a high-speed mixer and agitate it at a high speed with a suitable binder. Is a method of adding a solution containing the above. When the amount of the binder-containing solution is suppressed to a small amount and the rotation speed of the mixer is reduced, a substantially spherical granulated product can be obtained. Further, the alkali titanate fiber and the binder-containing solution are sufficiently kneaded to form a paste-like or cake-like kneaded product, which is extruded into a rod shape and cut into a suitable length, and the solvent is removed by drying to obtain a certain particle size constitution. It is possible to obtain a pellet-shaped granulated product.

The binder used for granulation should be selected according to the type of resin so that the fiber group can be easily disintegrated in the subsequent compound manufacturing process and uniformly dispersed in the resin, but general binders As MC (methyl cellulose), CM
C (carboxymethyl cellulose), starch, CMS (carboxymethyl starch, HEC (hydroxyethyl cellulose), HPC (hydroxypropyl cellulose), PVA (polyvinyl alcohol), polyacrylic acid ester, polymethacrylic acid ester, epoxy, phenol, vinyl acetate Examples of organic binders include water glass, colloidal silica, and inorganic binders such as colloidal alumina, which are used by dissolving in water or an organic solvent such as alcohols and ketones. Although it varies depending on the type, in order to impart excessive disintegration to the granulated product, it is preferable to keep the dry weight to about 3% or less with respect to the alkali titanate fiber. When the compound is manufactured, the strength of the granules becomes too strong. This is because not only the disintegration property deteriorates and the dispersion becomes poor, but this binder may be mixed in the compound as an impurity and adversely affect the physical properties of the final molded product.

In the present invention, the alkali titanate fiber-containing granulated product thus obtained is kneaded with a resin as a raw material to produce a resin compound, and the granulation results in a bulk density of 2
Since it is more than 3 times or more and the fluidity is extremely good, whether the pre-blending method or the side-feed method is adopted, a clogging accident occurs in the raw material supply process or the quantitative supply becomes unstable. Such a phenomenon does not occur, and a resin compound having a uniform composition can be smoothly produced. Further, there is no scattering of fibers in the handling process, which is very preferable from the viewpoint of environmental protection.

There is no limitation on the type of resin used in combination with the granulated product, and the resin may be selected according to the physical properties required for the final molded product, etc., but generally, polyester resin, polyamide resin Examples include thermoplastic resins such as polycarbonate resin, polyolefin resin, polyvinyl chloride resin, polyvinylidene chloride resin, and thermosetting resins such as unsaturated polyester resin, epoxy resin, phenol resin, melamine resin, and urea resin. .

The resin compound thus obtained is injection molded,
It can be processed into various shapes such as a plate shape, a tubular shape, a rod shape, and an irregular shape by any molding method such as extrusion molding or transfer molding after molding into a plate shape, and can be widely utilized as a fiber-reinforced resin molded body.

[Examples] (1) Granulation of alkali titanate fiber 1 kg of potassium titanate fiber (average diameter 0.4 μm, average length 8 μm)
m, bulk specific gravity of 0.1) was put into a Henschel mixer (trade name "FM20B" manufactured by Mitsui Miike Kakoki Co., Ltd.) and stirred at high speed. Among them, 1. of PVA (product name "Poval B20" manufactured by Denki Kagaku).
A 5% aqueous solution (viscosity 5 cps) 1 was added in the form of a spray and kneaded uniformly. The obtained kneaded product was passed through an extruder (manufactured by Fuji Paudal Co., Ltd., twin-screw pelleter, diameter 60 mm, screen mesh 1 mm), and the extruded linear material (diameter 1.5 mm) was cut into a length of 3 mm and then dried. Then, water was removed to obtain a granulated fiber having a diameter of 1.5 mm and a length of 3 mm. The bulk specific gravity of the granulated fiber was 0.40, which was 3 times or more the bulk specific gravity (0.14) of the raw material fiber.

(2) Manufacture of resin compound Twin-screw co-direction extruder (trade name "PCM-30" manufactured by Ikegai Tekko KK,
30% granulated fiber obtained above using a screw diameter of 30 mm)
And a resin compound consisting of 70% of polybutylene terephthalate (trade name "DURANEX 2002" manufactured by Polyplastics Co., Ltd.) were manufactured. The granular fibers were supplied by the side feed method, and the screw feeder attached to the extruder was used. The maximum compound manufacturing capacity at this time is 10 kg / hr
Met.

On the other hand, when a compound was attempted to be produced in the same manner as above using non-granulated potassium titanate fiber, the fiber became shelved in the hopper and could not be supplied, so the weight type feeder (Kubota Iron Works) The un-granulated fiber was supplied using a cassette weighing feeder "E-P-I-SB01" manufactured by the same company, but the compound production capacity is the maximum.
Only 4 kg / Hr was obtained.

(3) Evaluation of physical properties A test piece was prepared using each of the obtained compounds, and the physical properties (bending strength, tensile strength, impact strength, hardness, elongation, etc.) were compared. The ones using No. 1 had less impact, strength and elongation than those using ungranulated fibers. It is considered that this is because the amount of resin supplied increased and the breakage of the fiber during compounding decreased.

[Advantages of the Invention] The present invention is configured as described above, and by solidifying the alkali titanate fibers into granules to increase the bulk specific gravity and fluidity, the supply state can be made extremely stable, and the resin compound The homogeneity and the productivity can be remarkably enhanced. Moreover, since the granulated fibers do not easily scatter, the working environment is not polluted, and an excellent effect can be obtained in terms of environmental hygiene.

Claims (1)

[Claims] 1. An alkali titanate fiber is made into a collapsible granule with a binder, and the granule is kneaded with a resin to uniformly disperse the alkali titanate fiber in the resin while collapsing the granule. A method for producing an alkali titanate fiber-containing resin compound, which comprises dispersing.