WO2015199481A1

WO2015199481A1 - Method for preparing spherical furan resin particles

Info

Publication number: WO2015199481A1
Application number: PCT/KR2015/006534
Authority: WO
Inventors: 강세연; 성은진; 송세현; 손세일; 이홍우; 박찬수; 남우근; 이진구
Original assignee: 대원제약주식회사; 주식회사 퓨어스피어
Priority date: 2014-06-27
Filing date: 2015-06-26
Publication date: 2015-12-30
Also published as: KR20160001360A; CN106661173A; KR101592882B1; CN106661173B; JP2017519886A; JP6557687B2

Abstract

The present invention relates to: spherical furan resin particles prepared by remarkably reducing an aldehyde use amount by using a small amount of urea, not restricting the pKa of an acid to be used, and not using an inorganic acid or an organic acid containing a benzene ring, but by using an organic acid having a low molecular weight which is easy to handle; and a preparation method therefor.

Description

Spherical Furan Resin Particle Manufacturing Method

The present invention relates to a method for producing spherical furan resin particles, and to a method for producing spherical furan resin particles by three-way mixing using furfuryl alcohol, aldehydes, and urea, and a spherical furan resin obtained thereby.

Furan resin refers to phenol furfural resin, furfural acetone resin, furfuryl alcohol resin and the like obtained from furfural or furfuryl alcohol. Furfural is a very useful general purpose chemical which is widely used in recent years as a fine chemical intermediate material, a solvent, and a resin raw material for a special use. Also referred to as furan aldehydes greener purol-furfural of the formula is a C ₅ H ₄ O ₂ as a furan-2-hydroxy to Cavalli (furan-2-carbaldehyde) or an aromatic aldehyde is an aldehyde group CHO attached to the furan ring of the ring structure.

Furan resin (furfural resin, furfuryl alcohol resin) is a thermosetting plastic containing furangori, it is a liquid in appearance, but is cured by heat and used as a water-resistant adhesive. For example, when combined with nitrile rubber, flexible furan resin can be obtained, and it has excellent durability against oil, acid, alkali, and solvent. When adhesive coating is applied with epoxy resin, both defects are compensated for each other, and the corrosion resistance, It is possible to obtain a material having properties excellent in heat resistance, adhesion of epoxy resins and deformation.

In addition, impregnated with furfuryl alcohol in the graphite product and then carbonized at more than 1,000 ℃ becomes a product with low permeability, which is a special application of furan resin. There are two types of industrially produced phenol-furfural resins and furfuryl alcohol resins. The former is made by heating phenol and furfural in the presence of an alkali catalyst. Methylenetetramine is added and used as a molding material. The latter heats the furfuryl alcohol solution in the presence of an acid catalyst to synthesize a liquid initial condensate, and when used, adds an acid catalyst to cure.

Various blends of furan resins use acid catalysts, which are heated at relatively low temperatures to form intermediates and finally heat cured at high temperatures. Since it has excellent alkali resistance, it is used for linings applied to the inside of reaction vessels or storage tanks using acid alkali by reinforcing glass fibers as resin cement. The low viscosity furan resin, the initial condensate of furfuryl alcohol, is soluble in alcohol, the higher viscosity is partially soluble in alcohol, soluble in ethyl acetate, acetone, aromatic hydrocarbons, furfural, furfuryl alcohol, If it is made neutral, it is stable even if it is preserved for a long time. When acid is added to this, an insoluble cured resin is obtained, and room temperature curing is also possible depending on the type and amount of acid. Curing resins are resistant to acids, alkalis, organic solvents, etc., but are hard and weak. Therefore, when forming a molded product, a suitable filler or reinforcing material should be used in combination. In case of using strong acid as hardener, selection of filler is required. Carbon black, asbestos, diatomaceous earth, glass fiber, etc. do not have any problem because they are not eroded by acid, but wood flour (sawdust), woven fabric, and paper cannot be used. The initial condensate of furfuryl alcohol is modified and used because of its compatibility with various plasticizers, thermoplastic and thermosetting resins, natural resins, synthetic rubber, asphalt, and the like.

When furan resin is heated to furfuryl alcohol obtained by hydrogenation of furfural in the presence of an acid catalyst, a thermosetting furan resin excellent in chemical resistance is produced. Conventional Japanese Patent Application Laid-Open No. 2011-157463 uses furfuryl alcohol alone, and spherical furfuryl alcohol by self-condensation reaction using an acid catalyst such as alkylbenzenesulfonic acid having a pKa of less than 1,5 in the presence of a protective colloid. Disclosed is a method for producing resin particles, and the use of aldehydes is excluded, but there is a problem in that the pKa of the acid catalyst to be used must be limited.

In addition, Japanese Laid-Open Patent Publication No. 2011-157464 discloses a method for producing spherical furan-aldehyde resin particles using an acid catalyst such as alkylbenzenesulfonic acid in furfuryl alcohol and aldehydes in the presence of protective colloids. Korean Patent Publication No. 2013-035781 discloses spherical activated carbon particles formed by carbonizing spherical furan resin particles obtained by reacting furfuryl alcohol and aldehydes in the presence of a catalyst and a protective colloid. There is a disadvantage in that excessive use of aldehydes harmful to the human body, such as to stimulate.

In addition, the use of furfuryl alcohol alone or mixed to emphasize the use of organic acids having a large molecular weight, such as inorganic acid or alkylbenzene sulfonic acid containing a benzene ring when preparing the resin, it is mainly liquid, so care must be taken when storing and using .

In the mold industry, a technique of using furfuryl alcohol, aldehydes, and urea as a binder composition has been proposed, but the problem of excessive use of an acid having a high molecular weight resin or an inorganic acid or a high molecular weight organic acid as a curing agent is used. Moreover, after adding a hardening accelerator, a silane coupling agent is further mixed, and finally it mixes and uses in a refractory granular material like silica sand, and is different from this invention to manufacture and use spherical resin particle.

Accordingly, the present inventors have completed the present invention by developing a safer furan resin manufacturing method while studying to solve the technical and safety problems shown in the furan resin manufacturing method from the conventional furfuryl alcohol.

The present invention has been made to solve the problems of the prior art, the object of the present invention is not only to significantly reduce the amount of toxic aldehydes, but also to limit the pKa of the acid catalyst, a benzene ring that has a harmful effect on the human body It is to provide a spherical furan resin particle method that can improve the workability and further obtain a high strength by using a low molecular weight acid catalyst having a simple structure that is easy to handle because it does not contain.

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

In the mixing step, aldehydes are based on molar ratio 1 based on furfuryl alcohol, 0.01 to 0.25 mol, urea based on molar ratio 1 based on furfuryl alcohol, 0.02 to 0.26 moles, and water is 0.5 based on 100 parts by weight of furfuryl alcohol. It may be mixed by weight times ~ 15 weight times.

In addition, the acid catalyst may have 3 to 4 carbon atoms that do not include a benzene ring, and the acid catalyst is 0.1 parts by weight to 10 parts by weight based on 100 parts by weight of furfuryl alcohol.

Spherical furan resin particle can be obtained by said manufacturing method.

Another example of the present invention, the spherical activated carbon particles can be obtained through the carbonization and steam activation process for the produced spherical furan resin particles.

According to the present invention, the use of aldehydes can be significantly reduced by mixing a small amount of urea at the time of producing spherical furan resin particles, and it is possible to use acid catalyst without using conventional inorganic acid or alkylbenzene sulfonic acid type. The compressive strength of the furan resin particles produced therefrom and the spherical activated carbon obtained therefrom is also not limited to the pKa value of.

1 is a photograph taken by enlarging the spherical furan resin synthesized in Example 1 at 100 magnification

2 is a photograph taken by enlarging the spherical furan resin synthesized in Example 2 at 100 magnification

3 is a photograph taken by enlarging the spherical furan resin synthesized in Example 3 at 100 magnification

4 is a photograph taken by enlarging a spherical furan resin synthesized in Comparative Example 1 at 40 magnification

Unless defined otherwise, 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 a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless specifically stated otherwise.

The present invention significantly reduces the use of toxic aldehydes by selecting furfuryl alcohol as a conventional phenol substitute and by adding urea, and a benzene ring such as alkylbenzenesulfonic acid rather than strong acids such as sulfuric acid and hydrochloric acid. It relates to a method for easily preparing furan resin particles using organic acids having a simple structure (for example, maleic acid and malonic acid) rather than the acid type.

It has been found that the addition of a small amount of urea to reduce the amount of aldehydes while maintaining the spherical shape of the resin particles can significantly reduce the amount of aldehydes compared to the existing technology.

In addition, the range of pKa does not need to be limited by the manufacturing method which significantly reduces the amount of aldehydes used, and is not a high molecular weight organic acid such as an inorganic acid known as a strong acid or an alkylbenzenesulfonic acid type containing a benzene ring. It was found that reactions can be made using low molecular weight organic acid catalysts such as maleic acid (maleic acid, pKa = 1.9), malonic acid (pKa = 2.8). In addition, this type of organic acid has the advantage of being easy to store and use in a solid state rather than a liquid state.

Aldehydes used in the present invention means a compound containing an aldehyde group or a substance used to prepare such a compound or prepared by reacting with such a compound. As such aldehydes, formaldehyde is suitably used. In addition, the formaldehyde supply materials such as formalin, paraformaldehyde, trioxane, tetraoxane, acetal can be suitably used in consideration of reactivity, raw material price and the like.

The urea used in the present invention is in a solid grain state and is added to the reaction without the need for melting or pulverizing it specifically for the reaction, so that the workability is good and the cost is advantageous.

The compounding ratio of aldehydes and urea may be 0.01 to 0.25 mol (1 to 22 parts by weight of 35% by weight aqueous formaldehyde solution based on 100 parts by weight of furfuryl alcohol), preferably aldehydes per mole of furfuryl alcohol. Is 0.07 mol to 0.18 mol (6-16 parts by weight of 35% by weight aqueous formaldehyde solution based on 100 parts by weight of furfuryl alcohol).

Urea is 0.01 to 0.26 mol (0.6 to 16 parts by weight based on 100 parts by weight of furfuryl alcohol), preferably 0.08 to 0.19 moles (based on 100 parts by weight of furfuryl alcohol) per mole of furfuryl alcohol on a molar basis. 5 to 11.6 parts by weight). If the amount of aldehydes and urea used per mole of furfuryl alcohol increases, particle generation does not proceed, desired particles are not obtained, or the reaction proceeds slowly.

The amount of water used in the present invention may be a ratio of about 0.5 to 15 times by weight based on 100 parts by weight of furfuryl alcohol. If the amount of water is less than 0.5 wt. Times, the reactant may be lumped into an ovoid shape. If the amount of water is used more than 15 wt. Times, the reaction time becomes long, which causes difficulty in manufacturing.

Dispersion stabilizer in the present invention acts on the surface in the dispersion process of the particles, it is used to delay the aggregation, and can be used to select one or two or more kinds of water-soluble polymers such as gum, methyl cellulose, hydroxy ethyl cellulose. Arabian gum can be used as appropriate.

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 100 parts by weight of furfuryl alcohol. The acid catalyst mentioned in the present invention is in a solid state, and does not need to be dissolved in water to make a solution state, but may be mixed in the process of stirring during preparation. When the amount of the acid catalyst used is small, the reaction time may be long or hardening of the produced particles may be difficult, and when the amount of the acid catalyst is used, it may be difficult to produce agglomerates or to obtain desired microparticles.

The base used in the present invention is to make the atmosphere of the initial reactant to a basic atmosphere, and bases such as sodium hydroxide, potassium hydroxide, barium hydroxide 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 8-9 is suitably used. If the pH is not basic, the initial reaction does not proceed, and if the pH is too high, side reactions may occur in which aldehydes are not beneficial to the reaction.

Although the reaction temperature of this invention is 50 degreeC or more temperature, Preferably it is 70 degreeC or more. The reaction time is appropriately applied considering the reaction temperature, the state of the intermediate product, the state of particle curing, etc., but generally, about 2 to 30 hours are applied.

Spherical furan resin particles are obtained by filtering and washing the reactants produced by the above method, followed by drying.

Carbonization and steam activation of the spherical furan resin particles prepared according to the present invention give a porous spherical activated carbon having increased strength. Porous activated carbon with increased strength means that the spherical furan resin is carbonized and steam activated (heated at a temperature of 500 ° C. for 1 hour, carbonized, and heated to 900 ° C. under steam at 140 ° C. using a rotary external heat furnace for 140 minutes). When it refers to 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 up to 10 times higher than that of the activated carbon prepared by using pitch as a raw material.

Particularly, in the case of porous activated carbon using pitch as a raw material, the compressive strength is significantly low, and therefore, when formulated into a solid unit dosage form as a medicine, for example, when filled into a capsule, the activated carbon may be broken during the filling process. There was a losing problem. However, since the oral adsorbent is close to several g at a single dose, it is often caused by discomfort such as vomiting when taking it as a powder. Therefore, in practice, the oral adsorbent uses an auxiliary means such as Orlite. Administration is made. Therefore, the present invention is to prepare a spherical furan resin having a high compressive strength because of the need for a unit solid preparation that can greatly improve the convenience of dosing, and to obtain a porous spherical activated carbon as a result after carbonization and steam activation.

In the case of porous activated carbon using pitch as a raw material, since the compressive strength is remarkably low, there is a risk of damage even if it adheres to the inner skin of chemical protective clothing. Therefore, the necessity of manufacturing a spherical furan resin having a large compressive strength is great.

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

(1) average particle diameter

A particle diffraction diagram based on volume was prepared using a laser diffraction particle size distribution device (HELOS Particle Size Analysis, manufactured by Sympatec), and the particle size corresponding to Volume Mean Diameter (VMD) was used as the average particle size.

(2) strength measurement

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

One spherical activated carbon sample to be measured was placed in the middle of the compressive strength tip, and then the compressive strength was lowered at a speed of 20 mm / min to determine the compressive strength value. After measuring 22 spherical activated carbon samples in the same manner as described above, the compressive strength value was determined by taking the average of 20 tablets except the maximum and minimum values.

Hereinafter, the present invention will be described based on the following examples and comparative examples. The following examples and comparative examples are only for illustrating the present invention, and the present invention is not limited to the following examples and comparative examples.

Example 1.

Based on 100 parts by weight of furfuryl alcohol, 14 parts by weight of an aqueous 35 wt% formaldehyde solution, 10.5 parts by weight of urea, and 130 parts by weight of water are mixed and stirred, and a small amount of 5 wt% sodium hydroxide solution is added to adjust pH to 8.5. Stir at 2 ° C. for 2 hours. After 2 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, followed by further stirring for 2 hours. After stirring for 2 hours, the temperature was raised to 98 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 i-Solution (manufactured by IMT i-Solution Inc.) which is an image analysis program, and is shown in FIG. 1.

Example 2.

Based on 100 parts by weight of furfuryl alcohol, 6.5 parts by weight of 35 wt% formaldehyde aqueous solution, 5 parts by weight of urea, and 130 parts by weight of water were mixed and stirred, and a small amount of 5 wt% sodium hydroxide solution was added thereto to adjust pH 8.5. Stir at 2 ° C. for 2 hours. After 2 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 added to the mixture by heating to 70 ° C., followed by further stirring for 2 hours. After stirring for 2 hours, the temperature was raised to 98 ° C 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 i-Solution (manufactured by IMT i-Solution Inc.) which is an image analysis program, and is shown in FIG. 2.

Example 3.

Based on 100 parts by weight of furfuryl alcohol, 14 parts by weight of a 35 wt% formaldehyde aqueous solution, 10.5 parts by weight of urea, and 130 parts by weight of water are mixed and stirred. A small amount of 5 wt% sodium hydroxide solution is added to adjust pH to 8.5. Stir at 2 ° C. for 2 hours. After 2 hours, 100 parts by weight of furfuryl alcohol, 0.2 parts by weight of gum arabic, and 1.5 parts by weight of malonic acid are mixed and heated to 70 ° C., followed by further stirring for 3 hours. After stirring for 3 hours, the temperature was raised to 98 ° C 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 i-Solution (manufactured by IMT i-Solution Inc.) which is an image analysis program, and is shown in FIG. 3.

Comparative Example 1.

Based on 100 parts by weight of furfuryl alcohol, 30 parts by weight of an aqueous 35 wt% formaldehyde solution, 22 parts by weight of urea, and 130 parts by weight of water were mixed and stirred, and a small amount of 5 wt% sodium hydroxide solution was added thereto to adjust pH 8.5. Stir for 3 hours at ℃. 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 ° C., followed by further stirring for 3 hours. After stirring for 3 hours, the temperature was raised to 98 ° C., 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 furan resin. The obtained spherical furan resin was measured at 40 magnification using i-Solution (manufactured by IMT i-Solution Inc.) which is an image analysis program, and is shown in FIG. 4.

Comparative Example 2.

Based on 100 parts by weight of furfuryl alcohol, 55 parts by weight of 35 wt% formaldehyde aqueous solution, 40 parts by weight of urea, and 130 parts by weight of water are mixed and stirred. A small amount of 5 wt% sodium hydroxide solution is added to adjust pH to 8.5, and then the mixture is heated at 70 ° C. Stir for 4 hours. 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 ° C., followed by further stirring 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 material was produced.

The spherical furan resin particles obtained in Examples 1, 2, and 3 were carbonized by heating at 500 ° C. for 1 hour in a nitrogen atmosphere using an external thermal rotary kiln, and the spherical carbon particles obtained here were subjected to nitrogen using an external thermal rotary kiln. Spherical activated carbon was obtained by injecting steam in the atmosphere and heating it at 900 degrees for 140 minutes, which is called an activation process. Average particle diameter and compressive strength results for each of the examples are shown in the table below.

Table 1

division	Example 1		Example 2		Example 3		Comparative Example 1		Comparative Example 2
division	wt%	Molar ratio	wt%	Molar ratio	wt%	Molar ratio	wt%	Molar ratio	wt%	Molar ratio
Furfuryl alcohol	100	1.000	100	1.000	100	1.000	100	1.000	100	1.000
35 wt% formaldehyde aqueous solution	14	0.160	6.5	0.074	14	0.160	30	0.343	55	0.629
Urea	10.5	0.172	5	0.082	10.5	0.172	22	0.359	40	0.653
Maleic acid (pKa = 1.9)	1.5		1.5				1.5		1.5
Malonic acid (pKa = 2.8)					1.5
Arabian sword	0.2		0.2		0.2		0.2		0.2
10% sodium hydroxide	handful		handful		handful		handful		handful
water	130		130		130		130		130
Average particle size after activation (um)	376		394		358		Bad particle condition		No particles generated
Compressive strength after activation (N / sphere)	14.9		15.4		13.5		8.3

As can be seen in the above table, a small amount of urea can be used by mixing a small amount of urea, and it has a high compressive strength even if the acid catalyst has a high pKa without using an inorganic acid or an alkylbenzenesulfonic acid type. Spherical furan resin particles were obtained. Moreover, the compressive strength of the spherical activated carbon obtained from the spherical furan resin particle manufactured by this invention is also high, and it is easy to handle.

The specific parts of the present invention have been described in detail above, but are not limited to those illustrated in the drawings. For those skilled in the art, these specific descriptions are merely preferred embodiments, and thus, It will be clear that the scope is not limited. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims

Furan resin manufacturing method comprising the following steps:

(a) mixing a mixed solution of urea, furfuryl alcohol and water in a reactor;

(b) adjusting the pH of the mixed solution to pH 7.5 to pH 9.5;

(c) a step of introducing aldehydes, acid catalyst and gum into the reactor;

(d) curing step of curing furan resin.
The method of claim 1, wherein in the mixing step, aldehydes are 0.01 mol to 0.25 mol based on molar ratio 1 to furfuryl alcohol, urea 0.02 mol to 0.26 mol based on molar ratio 1 to furfuryl alcohol, and water is furfuryl alcohol Method for producing a furan resin that is mixed with 0.5 to 15 times by weight based on 100 parts by weight
The method of claim 1, wherein the acid catalyst has 3 to 4 carbon atoms that does not contain a benzene ring.
The method of claim 1, wherein the acid catalyst is 0.1 parts by weight to 10 parts by weight based on 100 parts by weight of furfuryl alcohol.
The method of claim 1, wherein the aldehyde is at least one selected from the group consisting of formaldehyde, paraformaldehyde, trioxane, tetraoxane, and acetal.
Spherical furan resin particle manufactured by the manufacturing method of any one of Claims 1-5.
Spherical activated carbon particles obtained by carbonization and steam activation of the spherical furan resin particles of claim 6.
The spherical activated carbon particles of claim 7 are spherical activated carbon particles which are fillers in oral administration adsorbents or chemical protective clothing.