JPS60123560A - Ceramic powder having modified surface - Google Patents

Abstract

PURPOSE:Ceramic powder having good wetting to organic solvents and molten resins, improved dispersibility, processing properties and adhesiveness to resins, obtained by treating ceramic powder with a specific compound such as an alkylbenzenesulfonic acid, etc. CONSTITUTION:Ceramic powder is treated with a compound selected from the group consisting of an alkylbenzenesulfonic acid (having 10-16C alkyl group on average), alkanesulfonic acid, alpha-olefinsulfonic acid, alkylsulfosuccinic acid ester (diester having 6-18C alkyl), alkylsulfuric acid ester (having 8-20C alkyl and 0.5-8mol of addition of EO on an average), polyoxyalkylene alkylphenyl ether sulfuric ester, alkylphosphoric acid ester and its salt. The amount of the compound used is 0.01-10wt%, preferably 0.1-3wt% based on the ceramic powder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface-modified ceramic powder, and more specifically, the surface of the ceramic powder is made hydrophobic (hydrogenated) to improve wettability and two-dispersibility with organic solvents and molten resin. This invention relates to an improved ceramic powder that has improved processability and adhesion to resin.

Ceramic powder is not only sintered and used as a raw material for ceramics, but it is also used in many fields, such as filling it into plastics to add various functions, and using its magnetism to make carriers for dry copying machines. ing. However, as is well known, ceramic powder has a hydrophilic surface and therefore has many problems such as poor wetting with molten resin or solvent, poor processability, and poor adhesion with resin. Injection molding and extrusion molding are particularly used as ceramic molding methods in recent years, but they require a large amount of resin because of their poor processability.

If the wetting with the resin is improved, the amount of resin used can be reduced and degreasing before sintering can be made easier, which is a great advantage. Even in plastic magnets, it is possible to increase the filling rate by improving the wetting.

Furthermore, carriers in developers used in electrophotography, electrostatic recording, etc. are also coated with polymers to improve durability, but in this case too, the adhesion between ferrite and polymer is poor, so the polymer during use There are problems such as peeling of layers.

In this way, improvement of null// is an important issue for the utilization of ceramic powder.

In addition to improving the wetting with organic solvents and molten resin,
Reducing hygroscopicity through surface modification is also an important processing issue.

In order to solve the above problems, a method of treating ceramic powder with a silane coupling agent has been proposed, but it is not satisfactory.

As a result of intensive research to solve the above problem, the present inventors discovered that the wettability can be greatly improved by treating ceramic powder with a specific compound, and completed the present invention.

That is, the present invention uses ceramic powder as an alkylbenzene sulfonic acid, an alkanesulfonic acid, an α-olefin sulfonic acid, an alkyl sulfosuccinate, an alkyl sulfate, or a polyoxyalkylene alkyl ether sulfate.

, J-'IJ, d-xyalkylene alkylphenyl ether sulfate, alkyl phosphate, and salts thereof. This is what we provide.

It is believed that the surface-modified ceramic powder of the present invention exhibits excellent wetting and dispersibility because the above-mentioned compounds are adsorbed on the surface of the ceramic powder either as is or by salt exchange.

Generally, surfactants are used as inorganic pigments/
Although it is known that it can be used as an additive for solvent systems and inorganic pigment/molten resin systems, satisfactory results have not been obtained regarding the wettability and bidispersity of ceramic powders.

In the present invention, by pre-treating with a specific compound (adsorption 2 reaction), excellent effects that could not be obtained when used as an additive were obtained. Therefore,
In the present invention, it is important to treat with the above-mentioned specific compound, and also to treat with other compounds such as nonionic activators and cationic activators that cannot be adsorbed or reacted with ceramic powder through salt exchange. However, the remarkable effects of the present invention cannot be obtained.

The alkylbenzene sulfonic acid used in the present invention is preferably a linear or branched alkylbenzene sulfonic acid having an alkyl group having an average of 10 to 16 carbon atoms.

As the alkanesulfonic acid and α-olefin sulfonic acid, alkanesulfonic acid and α-olefin sulfonic acid having an average of 10 to 20 carbon atoms in one molecule are preferable.

As an alkyl sulfosuccinic acid ester, id is given by the following formula (
Compounds represented by 1) are preferred.

(In the formula, R1 and R2 are alkyl groups having 6 to 18 carbon atoms.) As the alkyl sulfate ester, those having a linear or branched alkyl group having an average of 8 to 20 carbon atoms are preferably used.

The polyoxyalkylene alkyl ether sulfuric acid ester is an alkyl ether sulfuric acid having a linear or branched alkyl group having an average carbon number of 8 to 20 and having an average of 0.5 to 8 moles of ethylene oxide added to each molecule. Esters are preferred.

As the polyoxyalkylene alkylphenyl ether sulfuric ester, a sulfuric ester of an ether prepared by adding 0.5 to 8 moles of ethylene oxide on average to an alkylphenol having a linear or branched alkyl group having an average of 6 to 14 carbon atoms is preferable.

The alkyl phosphate ester is preferably a linear or branched alkyl phosphate having 8 to 18 carbon atoms, and may be either a mono- or diester.

As already mentioned, a salt which is a neutralized product of the above compound may be used, but an acid form is preferable from the viewpoint of reactivity with ceramics and the problem of counter ions described later.

In addition, when adsorption is performed by salt exchange, counterions may not be completely removed, so ammonium salts are , it is better to use amine salts. Further, solubility in water is not particularly important, but water-soluble or water-dispersible materials are advantageous in order to facilitate processing.

Specific examples of the ceramic of the present invention include alumina, zirconia, ferrite, and sialon.

Cordjurai) & d.

The treatment of ceramic powder in the present invention involves dissolving or dispersing the above-mentioned compound or its salt in water or an organic solvent, then adding the ceramic powder, heating and stirring if necessary, and then separating the supernatant liquid. This can be done by washing if necessary and then heating and drying.

The amount of the above-mentioned compound or its salt used in the treatment is 0.01 to 10% by weight, preferably 0.01 to 10% by weight, based on the ceramic powder.
．． It is 1 to 5% by weight.

The present invention will be explained below with reference to Examples.

Alumina (Showa Light Metal Co., Ltd. jJI AL-160EIG) 1100 y was placed in a 1 ton separable flask.
and ion-exchanged water 4007, stir to disperse (2), and while continuing to stir, add dioctyl sodium sulfosuccinate (
Kao Soap Co., Ltd. Perex 0TP) 12? was added, and stirring was continued for an additional hour. Thereafter, the supernatant liquid was separated by centrifugation, and 400 r of ion-exchanged water was added to the slurry again (n) for washing. Centrifugation was performed again to remove the supernatant liquid, and then dried and dried to obtain treated powder 1. Obtained.

Regarding the supernatant liquid subjected to Pellex OTP treatment, Na
, S was analyzed and found to be NaO, 10%.

SO, 08%, and compared to the values of Na, 0.10 and S0.14 obtained by dissolving Pellex OTP in the same way, the Na concentration remains the same, only dioctyl sulfosuccinic acid decreases, and the ion It is presumed that they are adsorbed in an exchange manner.

The ash content of the obtained treated powder was 98.7%, and the Na content was 32'.
It was OPpm.

Example 2 Toluene 2502 in a 500ml separable flask,
Take dodecyl phosphate 5f, stir and dissolve,
Add the same alumina 2502 as in Example 1 and add 2 while stirring.
Reflux was performed for a period of time. After cooling, the slurry from which the supernatant was removed by centrifugation was suspended in 2002 toluene, centrifuged twice, washed, and dried to obtain treated powder 2.

The ash content of the obtained treated powder was 99.1%.

The following tests were conducted on the treated powders obtained in Examples 1 and 2 above.

Test 1 Treated powders 1 and 2 and untreated AL-16 as a comparative product
Oil absorption was measured using 0SG, a mixture of ATJ-160SG and Perex OTP, a mixture of AL-1608G and dodecyl phosphate, and AL-1608G treated with a silane coupling agent.

The results are shown in Table 1. As is clear from Table 1, it can be seen that the oil absorption of the products of the present invention is greatly reduced, and the wettability to organic solvents is improved.

Table 1 Test 2 The kneading torque of molten styrene and alumina powder shown in Table 2 was measured using a Brabender mixer button. That is, after gelling 12 g of styrene, 242 g of alumina powder and 0.77 g of stearic acid were added and kneaded for 10 minutes. The torque was measured and shown in Table 2. As is clear from Table 2, it can be seen that in the products of the present invention, crosstalk torque is greatly reduced and workability is improved.

Table 2 Example 3 Alumina (AL-1608G) was treated in the same manner as in Example 1 using the various compounds shown in Table 3. The same measurements as in Test 1 were performed on the obtained powder. The results are shown in Table 6.

Applicant's agent Kaoru Furutani

Claims (1)

[Claims] Ceramic powder alkylbenzene sulfonic acid, alkanesulfonic acid, α-olefin sulfonic acid, alkyl sulfoconolate, alkyl sulfate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkyl phenyl ether sulfate ester. A surface-modified ceramic powder obtained by treatment with one or more compounds selected from the group consisting of alkyl phosphates and salts thereof.