KR101814819B1 - Binder Capable of Being Dissolved in Organic Solvent for Organic Porous Ceramic Extrusion - Google Patents

Abstract

The present invention relates to an organic solvent-soluble binder for extrusion of organic porous ceramics, which comprises acetylated cellulose ether as an organic solvent-soluble binder and enables the extrusion of an organic solvent porous ceramic using such an organic solvent-soluble binder, Accordingly, the energy consumption due to the high temperature drying in the extrusion of the waterborne porous ceramics can be reduced, and other extrusion properties can be maintained at the same or superior level.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic solvent-soluble organic solvent-soluble organic solvent for extrusion of organic porous ceramics,

The present invention relates to an organic solvent-soluble binder for extrusion of organic porous ceramics. More particularly, the present invention relates to an organic solvent-soluble binder for extrusion of organic porous ceramics capable of dissolving an organic solvent by acetylating cellulose ether.

As environmental regulations are strengthened, the demand for catalytic filters for air purification is increasing every year.

The catalyst filter is manufactured by an extrusion process and uses water-based clay mixed with porous ceramic powder and various additives.

The extrusion process is roughly divided into raw material mixing, extrusion, drying, and heat treatment (sintering and sintering). In the drying process, water required for mixing is dried. To dry the water, a high temperature condition of 100 ° C or more is required.

In the drying process, problems such as crack formation of the catalyst carrier and energy reduction for raising the temperature of 100 ° C or more have been caused. Such problems are caused by organic solvents having lower boiling points than water, for example, acetone, DMF It is difficult to produce organic clay by using water soluble binder in most extrusion process.

Cellulosic binders have been mainly used as conventional porous ceramic extrusion binders. The cellulose-based binder can be used as a water-soluble polymer binder while activating a hydroxyl group in a unit structure of cellulose or substituting an alkyl group containing another hydroxyl group while destroying the crystal structure of cellulose.

Representative porous cellulose ceramics extruded cellulose-based binders include methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropylmethyl cellulose (HPMC), hydroxypropylethyl cellulose (HPEC) Methylcellulose (HEMC) and methylethylhydroxyethylcellulose (MEHEC). In the porous ceramic extrusion using such a water-soluble binder, the extrusion performance such as the extrusion pressure and the extrusion speed is excellent. However, in order to dry the water after the extrusion, the energy consumption is inevitable. It is necessary to solve not only the energy consumption due to the high-temperature process but also the problem of cracking of the formed body caused by the high temperature drying.

Such a problem can be solved by using an organic solvent having a boiling point lower than that of water. However, since a water-soluble binder such as methyl cellulose, hydroxypropylmethyl cellulose, and hydroxyethyl methyl cellulose is used in the porous ceramic extrusion process, Ceramic extrusion is impossible.

Accordingly, the present inventors have developed an organic solvent-soluble binder capable of extruding porous ceramics capable of exhibiting an extrusion performance equivalent to that of a water-based clay and a catalyst carrier property even when a low organic solvent such as acetone or DMF having a boiling point lower than that of water is used Thereby completing the invention.

Accordingly, an object of the present invention is to provide an organic solvent-soluble binder capable of extruding porous ceramics.

In order to solve the above problems, the present invention provides an organic solvent-soluble binder for extrusion of organic porous ceramics containing acetylated cellulose ether.

In the acetylated cellulose ether as the organic solvent-soluble binder for extrusion of the organic porous ceramics according to the present invention, the degree of substitution (DS) of the acetyl group is preferably 1 to 2.

The cellulose ether preferably has at least one substituent selected from the group consisting of methyl, ethyl, propyl, hydroxymethyl, hydroxyethyl and hydroxypropyl.

The substitution degree (DS) of the methyl group, ethyl group or propyl group is 1 to 2, and the degree of substitution (MS) of the hydroxymethyl group, hydroxyethyl group or hydroxypropyl group is preferably 0 to 1.

The acetylated cellulose ether binder prepared according to the present invention enables the dissolution of organic solvent to enable the extrusion of the organic solvent porous ceramics and thus the energy consumption due to the high temperature drying in the extrusion of the conventional water based porous ceramics can be reduced, Other extrusion properties can be maintained at the same or superior level.

Hereinafter, the present invention will be described in more detail.

Cellulose has three hydroxyl groups per unit structure, which regularly form intermolecular and intramolecular hydrogen bonds. These hydrogen bonds form a strong crystal structure and therefore have a stable structure that is insoluble in water or an organic solvent.

The conventional cellulose-based water-soluble binder enables the cellulose to be dissolved in water by activating the hydroxyl group in the cellulose unit structure or replacing the alkyl group containing another hydroxyl group by destroying the crystal structure of the cellulose through the etherification reaction, The present invention relates to a cellulose-based binder which is soluble in an organic solvent through a sequential acetylation reaction after the etherification reaction of cellulose and is capable of acting as a binder in an organic solvent.

Thus, according to one embodiment of the present invention, the present invention is an organic solvent-soluble binder for extrusion of organic porous ceramics containing acetylated cellulose ether.

In this embodiment, the substitution degree (DS) of the acetyl group in the acetylated cellulose ether is preferably in the range of 1 to 2. Here, the degree of substitution of the acetyl group refers to the average number of acetyl groups substituted per cellulose unit, and when the degree of substitution of the acetyl group is less than 1, the solubility of the organic solvent may deteriorate due to the presence of the hydrophilic -OH group.

Further, in this embodiment, the cellulose ether is one having at least one substituent selected from the group consisting of methyl, ethyl, propyl, hydroxymethyl, hydroxyethyl and hydroxypropyl, for example, hydroxyethyl methylcellulose, Hydroxypropylmethylcellulose or methylcellulose.

The degree of substitution (DS) of the methyl group, the ethyl group or the propyl group and the degree of substitution (MS) of the hydroxymethyl group, the hydroxyethyl group or the hydroxypropyl group are not particularly limited as far as the acetylation- The degree of substitution (DS) of the methyl group, the ethyl group or the propyl group is 1 to 2, and the degree of substitution (MS) of the hydroxymethyl group, the hydroxyethyl group or the hydroxypropyl group is 0 to 1 .

The organic solvent-soluble binder for extrusion of organic porous ceramics according to the present invention can be obtained by forming a cellulose ether through an ether reaction on cellulose and then forming an acetylated cellulose ether in which the cellulose ether is subjected to an acetylation reaction.

The formation of the cellulose ether through the ether reaction on the cellulose can be formed by a general method in this field, thereby activating the hydroxyl group in the cellulose unit structure while destroying the crystalline structure of the cellulose, or reacting an alkyl group containing another hydroxyl group To be dissolved in water.

Cellulosic ethers that can be obtained through this step are cellulose ethers having at least one substituent selected from methyl, ethyl, propyl, hydroxymethyl, hydroxyethyl or hydroxypropyl.

The subsequent cellulose ether is subjected to an acetylation reaction to obtain an acetylated cellulose ether. As a result, the acetylated cellulose ether can be a binder having solubility in an organic solvent.

When such acetylated cellulose ether is used as a binder, extrusion of porous ceramics using an organic solvent is possible. In addition, the extrusion molding temperature can be lowered through the porous ceramic extrusion using an organic solvent, and other extrusion properties can be obtained with the same quality as in the extrusion of water-based porous ceramics.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples.

Example  One

As shown in the following Table 1, hydroxypropyl methylcellulose having a methyl group substitution degree of 1.84 and a hydroxypropyl group substitution degree of 0.25 was subjected to acetylation reaction with stirring at 85 캜 for 8 hours. Subsequently, after completion of the reaction, the reaction solution was sprayed into a coagulating bath to coagulate, rinsed with pure water 5 times, and dried to prepare acetylated cellulose ether. In this case, the substitution degree of the acetyl group was 1.15.

Example  2

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that hydroxypropylmethylcellulose having a methyl group substitution degree of 1.83 and a hydroxypropyl group substitution degree of 0.19 was used. In this case, the substitution degree of the acetyl group was 1.15.

Example  3

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that hydroxypropylmethylcellulose having a methyl group substitution degree of 1.63 and a degree of substitution of hydroxypropyl group of 0.08 was used. In this case, the substitution degree of the acetyl group was 1.35.

Example  4

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that hydroxypropylmethylcellulose having a methyl group substitution degree of 1.40 and a degree of substitution of hydroxypropyl group of 0.21 was used. In this case, the substitution degree of the acetyl group was 1.57.

Example  5

Acetylated cellulose ether was prepared in the same manner as in Example 1 except that hydroxypropylmethylcellulose having a methyl group substitution degree of 1.20 and a degree of substitution of hydroxypropyl group of 0.83 was used. In this case, the substitution degree of the acetyl group was 1.78.

Example  6

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that methyl cellulose having a methyl group degree of substitution of 1.90 was used. In this case, the substitution degree of the acetyl group was 1.06.

Example  7

Acetylated cellulose ether was prepared in the same manner as in Example 1 except that hydroxyethyl methylcellulose having a methyl group substitution degree of 1.45 and a degree of substitution of hydroxyethyl group of 0.29 was used. In this case, the substitution degree of the acetyl group was 1.52.

Example  8

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that hydroxyethyl methylcellulose having a degree of substitution of methyl group of 1.47 and a degree of substitution of hydroxyethyl group of 0.22 was used. In this case, the substitution degree of the acetyl group was 1.50.

Example  9

Acetylated cellulose ether was prepared in the same manner as in Example 1, except that hydroxyethyl methylcellulose having a degree of substitution of methyl group of 1.86 and a degree of substitution of hydroxyethyl group of 0.33 was used. In this case, the substitution degree of the acetyl group was 1.13.

Degree of substitution DS (MeO) MS (HPO) MS (HEO) DS (Ac) Example 1 1.84 0.25 - 1.15 Example 2 1.83 0.19 - 1.15 Example 3 1.63 0.08 - 1.35 Example 4 1.40 0.21 - 1.57 Example 5 1.20 0.83 - 1.78 Example 6 1.90 - - 1.06 Example 7 1.45 - 0.29 1.52 Example 8 1.47 - 0.22 1.50 Example 9 1.86 - 0.33 1.13

Alkyl (methyl, hydroxypropyl, hydroxyethyl) degree of substitution: Alkyl iodide liberated by HI reaction was analyzed by GC analysis (ASTM D3876-79, D4794-94)

* Substitution degree of acetyl group: The acetyl group substitution degree (DS) of each of the above-mentioned acetylated cellulose ethers was measured by titrating the free acetic acid formed by the saponification reaction of the sample with alkali (ASTM D871-96)

Example  10 to 11

94% by weight of cordierite powder, 5% by weight of binder and 1% by weight of dextrin were mixed with acetylated cellulose ether obtained in Examples 1 and 4 as a binder, respectively, to prepare a clay. A solvent was added to the clay by 45 parts by weight with respect to 100 parts by weight of clay to obtain a porous ceramic clay.

Comparative Example  1 to 3

For comparison, clay was prepared as in Examples 10 to 11, using non-acetylated methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) as binders.

Evaluation example

The extrusion properties of the clay prepared in Examples 10 to 11 and Comparative Examples 1 to 3 were evaluated and are shown in Table 2 below.

The porous ceramic clay prepared as described above was evaluated for its extrusion properties with a 30 pie extruder, and a molded article produced by the extruder was subjected to a drying test in a constant temperature and humidity chamber. At this time, the drying temperature was set to 100 ° C for water extrusion and 60 ° C for acetone extrusion.

(Evaluation Items)

- Extrusion speed: Measuring the extrusion speed of the molded body discharged from 100 cell dice

- Extrusion pressure: Measures the pressure immediately before passing through the discharge part dice by PG

- Anti-cracking: Measurement of dry crack by 5-point method (tower characteristic)

Condition Experiment result bookbinder menstruum Extrusion speed (cm / min) Extrusion pressure (MPa) Anti-cracking Example 10 Example 1 Acetone 57.25 1.0 4 Example 11 Example 4 Acetone 56.25 0.9 5 Comparative Example 1 MC water 57.12 1.0 4 Comparative Example 2 HPMC water 56.75 1.2 4 Comparative Example 3 HEMC water 56.01 0.9 5

As can be seen from the above Table 2, when acetylated cellulose ether is used as a binder, an organic solvent can be used as a solvent. In spite of using an organic solvent, an extrusion rate, an extrusion pressure, The effect similar to that of the binder was obtained.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (4)

Organic porous ceramics;
An organic solvent-soluble binder including acetylated cellulose ether; And
And an organic solvent having a boiling point lower than that of water.
The method according to claim 1,
Wherein the cellulose ether has at least one substituent selected from the group consisting of methyl, ethyl, propyl, hydroxymethyl, hydroxyethyl and hydroxypropyl.
3. The method of claim 2,
Wherein the degree of substitution (DS) of the methyl group, the ethyl group or the propyl group is 1 to 2, and the degree of substitution (MS) of the hydroxymethyl group, the hydroxyethyl group or the hydroxypropyl group is 0 to 1.
4. The method according to any one of claims 1 to 3,
Wherein the degree of substitution (DS) of the acetyl group of the acetylated cellulose ether is 1 to 2.