KR100219792B1 - Catalyst for preparing poly(tetramethylene ether glycol diester) and process for preparing it using the same - Google Patents

Abstract

The present invention provides a catalyst obtained by activating the kaolin from Korea, which is mainly composed of halosite, by acid treatment and / or ammonium chloride treatment, and calcining, and a method for preparing polytetramethylene ether glycol diester using the same.

According to the present invention, PTMEG diesters having uniform physical properties and very narrow molecular weight distribution ranges can be easily produced.

The polytetramethylene ether glycol diester of the present invention is used as a main raw material of polyurethane, thermoplastic polyester, polyamide elastomer and the like used in spandex artificial leather.

Description

Catalyst for producing polytetramethylene ether glycol diester and method for producing polytetramethylene ether glycol diester using the same

The present invention relates to a method for producing polytetramethylene ether glycol diester, and more particularly, to polytetramethylene ether glycol by polymerizing tetrahydrofuran in the presence of anhydrous carboxylic acid, using a Korean kaolin catalyst as a polymerization catalyst. (polytetramethyleneetherglyco1: hereinafter referred to as PTMEG) A method for preparing a diester and a catalyst used therein.

PTMEG diester, which is the final product of the present invention, is a known compound and is an industrially very useful polymer used for main raw materials of polyurethane, thermoplastic polyester, polyamide elastomer, and the like used in spandex, artificial leather and the like. In recent years, the company is drawing attention as an engineering material and a medical polymer mainly in the elastomer field.

Such PTMEG diesters are industrially prepared by polymerizing tetrahydrofuran (THF), which is a cationic polymerization reaction, and since the reaction does not proceed easily, it is necessary to use an appropriate polymerization catalyst.

U.S. Patent Nos. 3, 433, 829 disclose a process for producing PTMEG diesters by polymerizing purified THF in the presence of anhydrous carboxylic acid using a bleached-bed fixed bed catalyst. However, the bleached earth employed in the above method is a natural aluminum silicate belonging to the montmorillonite mineral, and the physical activity and chemical properties of the montmorillonite mineral are changed according to the mining location, so that the activity of the catalyst is not constant and the degree of polymerization is about 10 PTMEG di. Esters were preparable.

Still other methods of using aluminum silicate catalysts are disclosed in Japanese Patent Application Laid-Open Nos. Hei 4-306228, Hei 4-277522, and U.S. Patent Nos. 5, 210, 283 and 5, 208, 385. However, the aluminum silicate catalyst used in these methods also has a problem that the activity is not constant, and the activity varies depending on the reaction time or use period each time, making it difficult to use commercially.

On the other hand, PCT International Application Publication No. WO94 / O5719 discloses THF in the presence of anhydrous carboxylic acid using any one catalyst selected from synthetic amorphous aluminum silicate, kaolin calcined after activation by acid treatment or zeolite treated by the same method. A method of polymerizing to produce PTMEG diesters is disclosed.

However, the catalyst used in this method also has a problem in that activity is not constant and reaction selectivity and catalyst persistence are poor.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a method for producing a PTMEG diester stably without a change in the activity of the catalyst and a catalyst used therein.

Another object of the present invention is to provide a method for producing TMEG diester having a uniform physical properties and a narrow molecular weight distribution range.

It is still another object of the present invention to provide a catalyst which is very inexpensive and which can adjust the polymerization time, molecular weight distribution, and molecular weight within a range suitable for commercialization, and a method for producing PTMEG diester using the same.

In order to achieve the above object, the present invention provides a catalyst for polytetramethylene ether glycol diester polymerization and polytetramethylene ether glycol diester obtained by calcination after activating kaolin from Korea by acid treatment and / or ammonium chloride treatment. It provides a method of manufacturing.

The catalyst of the present invention was prepared based on Korean kaolin, which has been widely distributed in Korea. Korean kaolin is composed of 75 ~ 95% by weight of Haloysite, 5 ~ 20% by weight of Illite, and 0 ~ 5% by weight of Kaolinite. Halloysite). Unlike kaolinite, the crystal structure of halosite is a two-layered rectangular acicular or columnar crystal (3 to 6 in diameter and length ratio). Kaolinite is processed and processed into ceramic materials, paper processing, plastic total agent, paint, etc. Although it has been used as a catalyst, of course, it is known that the halosite cannot be used for the ceramic material offering due to its unique crystallographic characteristics.

As described above, in the present invention, when THF is polymerized using a calcined catalyst after treating the halosite with acid treatment and / or ammonium chloride, the reaction rate is surprisingly fast, so that it has high conversion, as well as uniform physical properties and narrow molecular weight distribution. PTMEG diester was prepared, and the activity of the catalyst was also very good to obtain good repeat polymerization results.

The catalyst according to the invention can be activated by acid treatment or ammonium chloride treatment. However, acid treatment of the catalyst followed by ammonium chloride treatment can further improve the activation of the catalyst.

Korean kaolin used in the present invention contains halides (A1 ₂ O ₃ · 2SiO ₂ · 4H ₂ O) as a main component and contains cations such as illite, small amount of kaolinite, and metal oxide, and can be represented by the following formula. .

_{M 2 / n O · A1 2} O3 · 2SiO 2 · 4H 2 O

(Wherein n = M cationic atom,

M = metal)

The halosites containing these metal cations become active when converted to the protonated form.

Various types of silicates and aluminum magnesium hydrosilicates containing these metal cations are known to become active when converted to the protonated form. Cationization can be achieved, for example, by acid treatment with an inorganic acid such as halogen acid, sulfuric acid, phosphoric acid, nitric acid or perchloric acid or, if desired, an organic acid such as formic acid or acetic acid.

In addition, the catalyst of the present invention may be cationicized by treatment with an aqueous solution of ammonium chloride (NH ₄ C1). Acid treated or ammonium chloride treated catalysts can be calcined to further improve activation.

In addition, the catalyst of the present invention, the acid treatment of the cation, and then treated with an aqueous solution of NH ₄ C 1 and then substituted with an ammonium cation and then calcined to be changed to Bronsted acid can further improve the activity.

When the catalyst of the present invention is treated with acid treatment and / or ammonium chloride and calcined, Korean kaolin may be expressed as changed as follows.

Korean kaolin is a needle or columnar halosite mineral widely distributed in Korea, and when acid treated, it has an acid center on its surface. After the acid-treated kaolin is reacted with NH ₄ CI solution, the resulting kaolin ammonium composite is calcined to obtain kaolin suitable as a component of the present catalyst which is more activated than the acid-treated kaolin.

The catalyst of the present invention is powdered Korean kaolin (haloysite) after acid treatment and ammonium chloride treatment to knead into a spherical or cylindrical shape of a size suitable for a fixed phase catalyst, and then 2 hours to 16 hours within a temperature range of 200 ℃ to 850 ℃ It is preferable to use it after firing for a time and the moisture content is less than 1% by weight so that the reaction effect is good.

The PTMEG diester produced by the present invention is represented by the following general formula.

R ^l CO-O- (CH ₂ -CH ₂ -CH ₂ -CH ₂ -0) _n -COR ²

(Wherein n is an integer of 2 to 150, R ¹ and R ² are each an alkyl group or an alkyl group derivative having 1 to 4 carbon atoms, and may be the same or different from each other.)

According to the research results of the present inventors, the catalyst used in the present invention is installed in a fixed catalyst phase or suspended in a container, and as a result, bleached earth, synthetic and natural aluminum silicate, which have been used conventionally with anhydrous carboxylic acid and THF mixture, can be Compared to expensive zeolites, montmorillonite and kaolinite, it was confirmed that the polymerization was carried out at a high polymerization rate, a fast polymerization rate, and a narrow molecular weight distribution to be converted into polytetramethylene ether glycol diester.

Furthermore, in the case of using the catalyst according to the present invention, relatively low-purity THF (up to 2% by weight of contaminants) contaminated with carbonyl groups such as ketones or esters can be used as a raw material, and as with other conventional catalysts, Due to their content, they can be polymerized without highly purified THF. For example, THF containing 0.2% by weight of water can be used.

Polymers polymerized by the process of the present invention have a very low content of crown ethers, and the catalysts of the present invention have a very long life with high adaptability to impurities.

The polymerization of THF is possible in both batch and continuous polymerization. In the external heat exchanger, an amount of catalyst capable of diffusing the heat of reaction into a fixed cylinder and a reaction content is circulated in a general cylindrical reactor equipped with an external heat exchanger. Warm up to the reaction temperature, and when the reaction is started to remove the heat of reaction using an external heat exchanger to make the reaction temperature constant.

Preferably, the reactant circulation is circulated from top to bottom, with an amount of circulation of 3 to 8 times the volume of the reactor per hour. In the case of continuous polymerization, it is preferable to produce 1% to 10% of the circulation amount per hour as a reactant and to replenish the reactor with the same amount.

The molecular weight distribution index (Mw / Mn according to the GPC analysis method) of commercial polytetramethylene ether glycol having an average molecular weight of about 2000 was 2.1 when using aluminum silicate as a catalyst, whereas the PTMEG diester prepared according to the present invention was converted into PTMEG. When the product is purified by etherification, the molecular weight distribution index of the product is 1.8 to 2, which is suitable for high elastic polyurethane fibers and polyurethane resins having excellent low temperature characteristics, and the content of crown ether is less than 0.08% by weight, which is much higher than that of conventional products. A narrow molecular weight distribution index and low impurity of crown ethers can be produced. In addition, it is remarkable that the life expectancy of this catalyst is 3-4 years or more, even if lower THF containing ketone and ester is used as a reaction raw material.

The catalyst of the present invention catalyzes in the presence of an anhydrous carboxylic acid as a reaction initiator, and anhydrides of aliphatic or aromatic carboxylic acids having 2 to 8 carbon atoms (e.g. acetic anhydride, propionic anhydride, Butyric anhydride, acrylic anhydride, methacrylic anhydride or succinic anhydride). It is economical to use acetic anhydride in the commercial process.

The catalyst effectively performs the polymerization at a reaction temperature of 10 ° C to 60 ° C and a reaction pressure of less than 5 gauge pressure, and has no advantage in temperature and pressure above the limit, and can produce PTMEG diesters of any polymerization degree within the range of polymerization degree 150. . The polymerization reaction by this catalyst depends on the polymerization temperature and the amount of carboxylic acid added, but the added carboxylic acid anhydride reacts at least 99% by weight. At a reaction temperature of 35 ° C. to 55 ° C., 40 to 65% by weight of the added THF is polymerized, and the unreacted THF is subjected to a distillation step, and can be reused for polymerization without being recovered and purified. The PTMEG diester polymerized by the process of the present invention can be hydrolyzed or transetherized by known methods to produce PTMEG.

Next, the Example of this invention is described. However, the present invention is not limited to the scope of these examples. Parts used in the following examples mean parts by weight.

Example 1

After adding 5% by weight of hydrochloric acid to Korean kaolin powder (origin: Korea), the mixture was allowed to stand for 30 minutes, and the excess filtrate was filtered through a filter. The method was repeated three times and then washed three times with distilled water. After the acid treatment, 10 weeks of NH ₄ C1 solution was added thereto, the mixture was briefly mixed, and the excess filtrate was filtered through a filter. This process was repeated three times and washed three times with distilled water.

Then, the wet powder dough was spherical shape having a diameter of about 4 mm, fired at 850 ° C. for 10 hours, and then cooled in a desiccator. 150 cm ^{3 of} the catalyst prepared above was added to an experimental reactor equipped with a stirrer at 50 ° C. in an oil batch, and 600 g of a reactant prepared at a ratio of 48% by weight of purified THF 97. and 52% by weight of acetic anhydride was added thereto. The polymerization was carried out with stirring at 10 rpm in an oil batch at 50 ° C. for 4 hours.

After the catalyst was separated, the reaction was analyzed to confirm that acetic anhydride was converted to about 99% PTMEG diacetate. Unreacted THF was 150 ° C., 5 mbar Abs. The PTMEG diacetate was 47% by weight of the reactant and the saponification number was 54.75 mgKOH / g, which corresponds to an average molecular weight of 2049 g / mol. After mixing PTMEG diacetate and the same amount of methanol, transesterification was carried out in the presence of 0.01% by weight of sodium medoside to convert PTMEG to a hydroxyl group of 57.99 mgKOH / g. This corresponds to an average molecular weight of 1965 g / mol. Unreacted methanol and oligomer were prepared at 200 ° C., 1 mbar Abs. The molecular weight distribution index (Mw / Mn by GPC analysis method) after removal from was 1.9.

Example 2

The same catalyst was used in the same manner as in Example 1, and 1% by weight of ethyl acetate as a contaminant was mixed with purified THF and acetic anhydride in the same composition, followed by polymerization. The average molecular weight of diacetate of PTMEG was the same and the average molecular weight of PTMEG was the same, but the molecular weight distribution index was 2. 0.

Example 3

THF93 produced by the same method using a catalyst prepared by activating the same kaolin and firing at 750 ° C. in the same manner as in Example 1. The reaction product prepared at the ratio of 3% by weight and 6.7% by weight of acetic anhydride was polymerized at 50 ° C for 6 hours.

PTMEG diacetate reacted 52.43 wt%, and saponification number was 96.18 mgKOH / g, which corresponds to an average molecular weight of 1167 g / mol. The hydroxyl group of PTMEG transesterified in the same manner as in Example 1 was 103. 6 mgKOH / g, which corresponds to an average molecular weight of 1083 g / mol. Unreacted and oligomer were at 200 ° C., lmbar Abs. The molecular weight distribution index after removal from was 1.8.

Example 4

In the same manner as in Example 1, using a catalyst prepared by activating kaolin and calcination at 850 ° C., a reaction product prepared at a rate of 91.96 wt% of THF purified in the same manner was polymerized at 50 ° C. for 6 hours.

PTMEG diacetate reacted 54.85% by weight, and saponification No. was 130.78 mgKOT / g, which corresponds to an average molecular weight of 774 g / mol. The molecular weight distribution index was 1.6 after unreacted material and oligomer were removed at 200 ° C. and 1 mbar Abs.

As described in detail above, according to the present invention, PTMEG diesters having uniform physical properties and very narrow molecular weight distribution ranges can be easily produced.

Claims (4)

Polytetramethylene ether glycol diester obtained by activating Korean kaolin (including 75 to 95 weight 96 of halosite for the total weight) and then calcining for 2 to 16 hours in a temperature range of 200 to 850 ° C. Preparation catalyst. [Claim 2] The catalyst according to claim 1, wherein the Korean kaolin is acid treated and then ammonium chloride is activated again. Polytetramethylene ether glycol dike obtained by activating Korean Kaolin (containing 75 to 95 wt% of halosite to the total weight) by ammonium chloride treatment and then calcining for 2 to 16 hours in a temperature range of 200 ° C to 850 ° C. Catalyst for preparing esters. A method for producing polytetramethylene ether glycol diester by polymerizing tetrahydrofuran in the presence of anhydrous carboxylic acid, wherein the polymerization catalyst comprises kaolin from Korea (containing 75 to 95% by weight of halosite relative to the total weight). ) Is activated by acid treatment, ammonium chloride treatment, or acid treatment and ammonium chloride treatment, and then calcined for 2 to 16 hours in a temperature range of 200 ° C to 850 ° C.