KR101592882B1 - Manufacturing method for spherical particle of furan resin - Google Patents

Abstract

The present invention uses a small amount of urea to reduce the amount of aldehyde to be used, and does not limit the pKa of the acid used. It uses a low molecular weight organic acid which is not an organic acid containing an inorganic acid or a benzene ring and is easy to handle. And a method for producing the spherical furan resin particle.

Description

Technical Field [0001] The present invention relates to a method for producing spherical furan resin particles,

The present invention relates to a method for producing spherical furan resin particles, and relates to a method for producing spherical furan resin particles by trinary mixing using furfuryl alcohol, aldehyde types, urea, and spherical furan resins obtained thereby.

Furan resin refers to phenol furfural resin, furfural acetone resin, furfuryl alcohol resin and the like which can be obtained from furfural or furfuryl alcohol. Furfural is a very useful common chemical substance widely used for fine chemical intermediate materials, solvents, and resin raw materials for special use. Furfural is an aromatic aldehyde having an aldehyde group -CHO attached to a furan ring which is a ring structure, and is also referred to as furan-2-carbaldehyde or -furanaldehyde furfurol as C ₅ H ₄ O ₂ .

Furan resin (furan resin: Furfural resin, furfuryl alcohol resin) is a thermosetting plastic containing a furan ring, which is apparently liquid but is cured by heat and used as a water-resistant adhesive. For example, when combined with a nitrile rubber, a flexible furan resin can be obtained and exhibits excellent durability against oils, acids, alkalis, and solvents. When the coating is painted with an epoxy resin, both defects can be compensated for, It is possible to obtain a material having heat resistance and excellent properties of adhesion and deformation of an epoxy resin.

In addition, when graphite products are impregnated with furfuryl alcohol and then carbonized at a temperature of 1,000 ° C or higher, the product becomes a low permeability product, which is a special application of furan resin. Two types of resins are industrially produced, phenol-furfural resin and furfuryl alcohol resin. The former is prepared by heating phenol and furfural in the presence of an alkali catalyst, Methylenetetramine is added and used as a molding material. The latter is prepared by heating a furfuryl alcohol solution in the presence of an acid catalyst to synthesize an initial condensate in a liquid state, and then curing the mixture by adding an acid catalyst again.

Furan resin Various formulations use an acid catalyst, which is heated at a relatively low temperature to form an intermediate, and finally to a heat curing at a high temperature. Because of its excellent acidity in acidity, it is used as a resin cement to reinforce glass fibers and to lining the inside of a reaction vessel or storage tank using acid alkali. Furfuryl alcohol, which is an early condensation product, has a low viscosity. It dissolves in alcohol. When it has a high viscosity, it partially melts in alcohol and dissolves in ethyl acetate, acetone, aromatic hydrocarbon, furfural, furfuryl alcohol, If it is made neutral, it is stable even after long-term preservation. Insoluble curing resins can be obtained by adding an acid thereto, and room temperature curing is also possible depending on the type and amount of acid added. Cured resins are resistant to acids, alkalis, and organic solvents. They are hardened while being hardened. Therefore, when they are made into molded products, appropriate fillers or reinforcing materials should be used in combination. When using strong acid as a hardener, it is necessary to select a filler. Carbon black, asbestos, diatomaceous earth, glass fiber and the like are not problematic because they are not eroded by acid, but wood flour (sawdust), woven fabric, The initial condensation products of furfuryl alcohol are used because they are compatible with various kinds of plasticizers, thermoplastic and thermosetting resins, natural resins, synthetic rubbers, asphalt and so on.

When the furan resin is heated in the presence of an acid catalyst to furfuryl alcohol obtained by hydrogenation of furfural, a thermosetting furan resin having excellent chemical resistance is produced. Japanese Patent Laid-Open Publication No. 2011-157463 discloses that furfuryl alcohol alone is subjected to a self-condensation reaction using an acid catalyst such as alkylbenzenesulfonic acid having a pKa of less than 1,5 in the presence of protective colloid to obtain spherical furfuryl alcohol And the use of the aldehyde type is excluded, but the pKa rule of the acid catalyst to be used should be limited There is a problem.

 Japanese Laid-Open Patent Publication No. 2011-157464 discloses a method for producing spherical furan-aldehyde resin particles by using an acid catalyst such as alkylbenzenesulfonic acid in the presence of furfuryl alcohol and aldehyde in the presence of protective colloid. Laid-Open Patent Publication No. 2013-035781 discloses spherical activated carbon particles formed by carbonizing spherical furan resin particles obtained by reacting furfuryl alcohol and aldehyde species in the presence of a catalyst and protective colloid. However, Which is harmful to the human body, is used in excess.

In addition, when a resin is produced by using furfuryl alcohol alone or in combination, emphasis is placed on the use of an organic acid having a large molecular weight such as an alkylbenzenesulfonic acid containing an inorganic acid or a benzene ring. Loses.

In the mold industry, a technique of using furfuryl alcohol, an aldehyde type, and urea as a binder has been proposed. However, in the case of an acid in the form of a resin having a large molecular weight, a problem of using an excessive amount of the inorganic acid or an organic acid having a large molecular weight And the present invention is different from the present invention in that a spherical resin particle is produced and used in that a hardening accelerator is added and then a silane coupling agent is further mixed and finally mixed with refractory granular materials such as silica sand.

Accordingly, the inventor of the present invention developed a safer furan resin manufacturing method while solving the technical and safety problems of conventional furfuryl alcohol from the furan resin manufacturing method, thereby completing the present invention.

It is an object of the present invention to solve the problems of the prior art, and it is an object of the present invention to provide a method for producing a benzene ring, which not only significantly reduces the amount of aldehyde which is highly toxic but also limits the pKa of the acid catalyst, And which can improve workability by using a low-molecular-weight acid catalyst having a simple structure which is not easy to handle and which can obtain a further high strength.

In order to achieve the above and other objects, the present invention provides a method for producing a mixture comprising mixing a mixed solution of urea, aldehyde and water in a reactor; (b) a pH adjusting step of adjusting the mixed solution to a pH of from 7.5 to 9.5; (c) introducing furfuryl alcohol, acid catalyst, and gum into the reactor; And (d) a curing step of curing the furan resin.

In the mixing step, the kind of aldehyde is 0.01 to 0.25 mol based on the molar ratio with respect to furfuryl alcohol, the urea is 0.02 to 0.26 mol based on the molar ratio with respect to furfuryl alcohol, 15 parts by weight.

The acid catalyst may have 3 to 4 carbon atoms which does not include a benzene ring, and the acid catalyst is 0.1 to 10 parts by weight based on the furfuryl alcohol.

The spherical furan resin particles can be obtained by the above-mentioned production method.

In another embodiment of the present invention, spherical activated carbon particles can be obtained through the carbonization and steam activation processes of the spherical furan resin particles produced.

According to the present invention, it is possible to remarkably reduce the use of the aldehyde class by mixing a small amount of the urea in the preparation of the spherical furan resin particles, and it is possible to reduce the use of the aldehyde class without using the conventional inorganic acid or alkylbenzenesulfonic acid class, , And the compressive strength of the prepared furan resin particles and the spherical activated carbon obtained therefrom is also increased.

[Figure 1] Photographs of a spherical furan resin synthesized in Example 1 at a magnification of 100 magnification
Fig. 2 Photographs of the spherical furan resin synthesized in Example 2 at a magnification of 100 magnifications
3] A photograph of the spherical furan resin synthesized in Example 3 at a magnification of 100 magnifications
4 is a photograph of the spherical furan resin synthesized in Comparative Example 1 taken at a magnification of 40 magnifications

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

In the present invention, furfuryl alcohol is selected as a conventional phenol substitute and reacted by adding urea to thereby significantly reduce the use of highly toxic aldehydes. The use of aldehydes such as benzene rings such as alkylbenzenesulfonic acids rather than strong acids such as sulfuric acid and hydrochloric acid (For example, maleic acid, malonic acid), which is not an acid type, and which has a simple structure.

It has been found that the addition of a small amount of element to reduce the amount of aldehyde species while maintaining the spherical shape of the resin particles can significantly reduce the amount of aldehyde used compared to the existing techniques.

In addition, the range of pKa is not limited by the production method in which the amount of the aldehydes is remarkably reduced, and it is not limited to a high molecular weight organic acid such as an alkylbenzenesulfonic acid type containing an inorganic acid or a benzene ring, It has been found that the reaction can be carried out using a low molecular weight organic acid catalyst species such as 3 to 4 levels of organic acids such as maleic acid (pKa = 1.9) and malonic acid (pKa = 2.8) , And this type of organic acid is not liquid but solid and is easy to store and use.

As the aldehydes used in the present invention, formaldehyde is suitably used. In view of reactivity and raw material cost, formaldehyde supplying materials such as formaldehyde, paraformaldehyde, trioxane, tetraoxane, and acetal can be suitably used as the formaldehyde.

The elements used in the present invention are solid granules and are added to the reaction without any special melting or pulverization for the reaction, so that they are good in workability and advantageous in cost.

The aldehydes and urea are mixed in an amount of 0.01 to 0.25 mol (1 to 22 parts by weight of 35% formaldehyde with respect to furfuryl alcohol) based on 1 mol of furfuryl alcohol, preferably 0.07 to 0.18 (6 to 16 parts by weight of 35% by weight formaldehyde for furfuryl alcohol).

(From 0.6 to 16 parts by weight, preferably from 0.08 to 0.19 moles (relative to furfuryl alcohol, from 5 to 11.6 parts by weight, based on the furfuryl alcohol, based on the furfuryl alcohol) to be. If the amount of the aldehyde and the amount of the urea to be used is increased with respect to 1 mole of furfuryl alcohol, there is a problem that particle generation does not proceed, desired particles are not obtained, or the reaction proceeds slowly.

The amount of water to be used in the present invention may be about 0.5 to 15 times by weight with respect to furfuryl alcohol. If the amount of water is less than 0.5 times by weight, the reaction product may be agglomerated into an oval shape. Further, when the amount of water is more than 15 times by weight, the reaction time becomes long,

In the present invention, the dispersion stabilizer acts on the surface in the course of dispersing the particles and is used for retarding aggregation. One or more kinds of water-soluble polymer type such as gum, methyl cellulose, and hydroxyethyl cellulose can be selected and used , And an Arabian gum can be used appropriately.

The acid catalyst used in the present invention is generally used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 4 parts by weight, based on the furfuryl alcohol. The acid catalyst referred to in the present invention is in a solid state, and it is not necessary to dissolve the acid catalyst in a solution state separately. The catalyst may be mixed in a process of stirring at the time of production. When the amount of the acid catalyst used is small, the reaction time may become long or the hardening of the generated particles may become difficult. When the amount of the acid used is too large, it becomes difficult to produce lumps or obtain desired microparticles.

The base used in the present invention is to make the atmosphere of the initial reactant into a basic atmosphere, and bases such as sodium hydroxide, potassium hydroxide, barium hydroxide and the like may be used, and sodium hydroxide may be suitably used.

The basic atmosphere used in the present invention is pH 7.5 to 9.5, preferably pH 8 to 9, as appropriate. If the pH is not basic, the initial reaction does not proceed. If the pH is too high, aldehydes may cause side reactions that are not favorable to the reaction.

The reaction temperature of the present invention is a temperature of 50 DEG C or higher, but is preferably 70 DEG C or higher. The reaction time is suitably applied in consideration of the reaction temperature, the state of the intermediate product, the state of particle hardening, etc., but usually about 2 to 30 hours are applied.

The reaction product produced by the above method is filtered, washed and then dried to obtain spherical furan resin particles.

Carbonization and steam activation of the spherical furan resin particles produced by the present invention yields porous spherical activated carbon having increased strength. The porous activated carbon with increased strength means that the spherical furan resin is activated by carbonization and steam activation (carbonization by heating at a temperature of 500 ° C for 1 hour and heating at 900 ° C for 140 minutes under water vapor using a rotary external heat furnace) Quot; means a porous activated carbon having a compressive strength of at least 10 N / sphere. The strength of the porous activated carbon has a strength of at least 2 times to at least 10 times as much as that of the activated carbon produced using the pitch as a raw material.

Particularly, in the case of a porous activated carbon having a conventional pitch as a raw material, since the compressive strength is remarkably low, when it is desired to formulate a solid unit dosage form as a medicine, for example, when filling the capsule, . However, when the oral adsorbent is dosed in a dose of about several grams per dose, it often causes discomfort such as vomiting. For this reason, in an actual dosing site, And the like. Therefore, in order to obtain a unit solid preparation capable of greatly improving dosage convenience, the present invention aims to prepare spherical furan resin having a high compressive strength and to obtain a porous spherical activated carbon as a result of carbonization and activation of water vapor.

In the case of a porous activated carbon having a conventional pitch as a raw material, since the compressive strength is remarkably low, there is a risk of breakage even if it adheres to the inner skin of the chemical protective clothing. Therefore, there is a great need to manufacture spherical furan resins having high compressive strength.

The average particle diameter and compressive strength of the spherical activated carbon according to the present invention are measured by the following methods.

(1) Average particle size

A particle size based cumulative diagram was created using a laser diffraction particle size distribution analyzer (HELOS Particle Size Analysis, manufactured by Sympatec), and the particle size corresponding to the volume mean diameter (VMD) was taken as the average particle size.

(2) Strength measurement

The strength of the spherical activated carbon was measured as follows using a compressive strength machine (AFK-500TE manufactured by Digitech).

After placing one sample of the spherical activated carbon to be measured in the middle of the compressive strength type tip, the strength at which the original spherical activated carbon was broken by setting the compressive strength at a rate of 20 mm / min was regarded as the compressive strength value. 22 aliquots of the spherical activated carbon samples were measured in the same manner as above, and the compressive strength values were obtained by taking the values of 20 eggs excluding the maximum value and the minimum value as an average.

Hereinafter, the present invention will be described based on the following examples and comparative examples. The following examples and comparative examples are for illustrative purposes only and are not intended to limit the present invention to the following examples and comparative examples.

Example 1.

14.5 parts by weight of 35% by weight formaldehyde, 10.5 parts by weight of urea and 130 parts by weight of water were mixed and stirred, and a small amount of a 5 wt% aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, Stir time. After 2 hours, 100 parts by weight of furfuryl alcohol, 0.2 part by weight of gum arabic and 1.5 parts by weight of maleic acid were mixed and heated to 70 DEG C and the mixture was further stirred for 2 hours. After stirring for 2 hours, the temperature was raised to 98 占 폚 and the reaction was terminated after 8 hours. After completion of the reaction, the reaction product is cooled to room temperature, filtered, and washed to obtain spherical furan resin particles. The obtained spherical furan resin was measured at 100 magnification using an image analysis program i-Solution (manufactured by IMT i-Solution Inc.) and is shown in Fig.

Example 2.

6.5 parts by weight of 35% by weight formaldehyde, 5 parts by weight of urea and 130 parts by weight of water were mixed and stirred, and a small amount of a 5 wt% aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, Stir time. After 2 hours, 100 parts by weight of furfuryl alcohol, 0.2 part by weight of gum arabic and 1.5 parts by weight of maleic acid were mixed and heated to 70 DEG C and the mixture was further stirred for 2 hours. After stirring for 2 hours, the temperature was raised to 98 占 폚 and the reaction was terminated after 8 hours. After completion of the reaction, the reaction product is cooled to room temperature, filtered, and washed to obtain spherical furan resin particles. The obtained spherical furan resin was measured at 100 magnification using an image analysis program i-Solution (manufactured by IMT i-Solution Inc.) and is shown in Fig.

Example 3.

14.5 parts by weight of 35% by weight formaldehyde, 10.5 parts by weight of urea and 130 parts by weight of water were mixed and stirred, and a small amount of a 5 wt% aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, Stir time. After 2 hours, 100 parts by weight of furfuryl alcohol, 0.2 part by weight of gum arabic and 1.5 parts by weight of malonic acid were mixed and heated to 70 DEG C, followed by further stirring for 3 hours. After stirring for 3 hours, the temperature was raised to 98 占 폚 and the reaction was terminated after 10 hours. After completion of the reaction, the reaction product is cooled to room temperature, filtered, and washed to obtain spherical furan resin particles. The obtained spherical furan resin was measured at 100 magnification using an image analysis program i-Solution (manufactured by IMT i-Solution Inc.) and is shown in Fig.

Comparative Example 1

30 parts by weight of 35% by weight formaldehyde, 22 parts by weight of urea and 130 parts by weight of water were mixed and stirred, and a small amount of a 5 wt% aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, Stir time. After 4 hours, 100 parts by weight of furfuryl alcohol, 0.2 parts by weight of gum arabic and 1.5 parts by weight of maleic acid were mixed and heated to 70 DEG C and the mixture was further stirred for 3 hours. After stirring for 3 hours, the temperature was raised to 98 占 폚 and the reaction was terminated after 15 hours. After completion of the reaction, the reaction product is cooled to room temperature, filtered, and washed to obtain a furan resin. The obtained spherical furan resin was measured at 40 magnification using an image analysis program i-Solution (manufactured by IMT i-Solution Inc.) and is shown in Fig.

Comparative Example 2

55 parts by weight of 35% by weight formaldehyde, 40 parts by weight of urea and 130 parts by weight of water were mixed and stirred, and a small amount of a 5 wt% sodium hydroxide aqueous solution was added to adjust the pH to 8.5, Stir time. After 4 hours, 100 parts by weight of furfuryl alcohol, 0.2 part by weight of gum arabic, and 1.5 parts by weight of maleic acid were mixed and heated to 70 DEG C and the mixture was further stirred for 5 hours. After stirring for 5 hours, the temperature was raised to 98 ° C, and the reaction was terminated after 24 hours, but no substance was produced.

The spherical furan resin particles obtained in Examples 1, 2 and 3 were carbonized by heating using a thermal rotary kiln in a nitrogen atmosphere at a temperature of 500 ° C. for 1 hour, and the spherical carbon particles thus obtained were subjected to heat treatment in nitrogen The activated carbon was obtained by injecting water vapor under the atmosphere and heating it at 900 ° C for 140 minutes. The average particle size and compressive strength results for each of the examples are shown in the table below.

As can be seen from the above table, a small amount of aldehyde can be used in a small amount by mixing a small amount of the element, and even when the pKa of the acid catalyst is high and the compression strength is high without using any of the inorganic or alkylbenzenesulfonic acid types Spherical furan resin particles were obtained. Further, the spherical activated carbon obtained from the spherical furan resin particles produced by the present invention has high compressive strength and is easy to handle.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments, It will be apparent that the scope is not limited. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

A method for producing a furan resin comprising the steps of:
(a) mixing a mixed solution of urea, aldehydes and water in a reactor;
(b) a pH adjusting step of adjusting the mixed solution to a pH of from 7.5 to 9.5;
(c) introducing furfuryl alcohol, acid catalyst, and gum into the reactor; And
(d) a curing step for curing the furan resin.   2. The method according to claim 1, wherein in the mixing step, the aldehydes are 0.01 to 0.25 mol based on the molar ratio of furfuryl alcohol, 0.02 to 0.26 mol of urea relative to furfuryl alcohol, and water is furfuryl alcohol By weight to 15 times by weight of the furan resin  The method for producing a furan resin according to claim 1, wherein the acid catalyst has 3 to 4 carbon atoms which does not contain a benzene ring. The method for producing a furan resin according to claim 1, wherein the acid catalyst is 0.1 part by weight to 10 parts by weight based on furfuryl alcohol. A spherical furan resin particle produced by the method of any one of claims 1 to 4. A spherical porous activated carbon particle having a compressive strength of 10 N / sphere or more by carbonization and steam activation of the spherical furan resin particles of claim 5. The spherical porous activated carbon particles of claim 6 having a compressive strength of at least 10 N / sphere are spherical porous activated carbon particles which are fillers in an oral dosage form adsorbent or chemical protective clothing.

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