KR101582808B1 - Methods for preparing wholly aromatic liquid crystalline polyester resin and wholly aromatic liquid crystalline polyester resin compound with enhanced physical properties - Google Patents

Abstract

A method for producing a wholly aromatic liquid-crystalline polyester resin and a method for producing an all-aromatic liquid-crystalline polyester resin compound are disclosed. The disclosed method for producing a wholly aromatic liquid-crystalline polyester resin includes polycondensation of a starting monomer using a metal acetate catalyst. The method for producing the wholly aromatic liquid-crystalline polyester resin compound includes a method for producing the wholly aromatic liquid-crystalline polyester resin.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a wholly aromatic liquid crystalline polyester resin having excellent physical properties and a method for producing an all-

A method for producing a wholly aromatic liquid-crystalline polyester resin and a method for producing an all-aromatic liquid-crystalline polyester resin compound are disclosed. More particularly, the present invention relates to a method for producing a wholly aromatic liquid-crystalline polyester resin comprising polycondensation of raw monomers using a metal acetate catalyst and a method for producing the wholly aromatic liquid-crystalline polyester resin A manufacturing method is disclosed.

The wholly aromatic liquid-crystalline polyester resin exhibits rigidity in a molecule, forms a liquid crystal state without entanglement between molecules even in a molten state, and exhibits a behavior in which molecular chains are oriented in the flow direction by shearing force during molding.

Because of these properties, the wholly aromatic liquid-crystalline polyester resin is widely used as a material for automobile parts, electric / electronic parts, and small-sized and precision molded articles because of excellent flow and heat resistance.

Particularly, the wholly aromatic liquid-crystalline polyester resin is used for a coil bobbin which is soldered at a high temperature because the polymer main chain is entirely composed of an aromatic group and excellent in heat resistance, a supporting member of a high-temperature electric heater and a light- . In addition, it is excellent in dimensional stability and electrical insulation, and its use as a material for films and substrates for electronic materials is expanding.

Such a wholly aromatic liquid-crystalline polyester resin is produced by polycondensation of at least two kinds of monomers. It is difficult to produce a wholly aromatic liquid-crystalline polyester resin having uniform physical properties because a part of raw monomers is also sublimated and discharged together with by-products discharged from the reactor during the polycondensation reaction. In addition, There is a problem that the physical properties are lowered. In addition, the sublimate is attached to the inner wall of the reactor, the pipe through which the by-product passes, and the heat exchanger in a large amount.

One embodiment of the present invention provides a method for producing a wholly aromatic liquid-crystalline polyester resin comprising polycondensation of raw monomers using a metal acetate catalyst.

Another embodiment of the present invention provides a method for producing a wholly aromatic liquid-crystalline polyester resin compound comprising a method for producing the wholly aromatic liquid-crystalline polyester resin.

According to an aspect of the present invention,

There is provided a method for producing a wholly aromatic liquid-crystalline polyester resin comprising polycondensing a starting monomer using a metal acetate catalyst.

In the method for producing the wholly aromatic liquid-crystalline polyester resin,

Synthesizing a wholly aromatic liquid-crystalline polyester prepolymer by polycondensation of at least two starting monomers using a metal acetate catalyst; And

And synthesizing the wholly aromatic liquid-crystalline polyester resin by solid-phase polycondensation of the prepolymer.

The amount of the metal acetate catalyst to be used may be 0.01 to 0.10 parts by weight based on 100 parts by weight of the total amount of the monomers.

The metal acetate catalyst may include at least one selected from the group consisting of magnesium acetate, potassium acetate, calcium acetate, zinc acetate, manganese acetate, acetic acid, antimony acetate and cobalt acetate.

According to another aspect of the present invention,

There is provided a method for producing a wholly aromatic liquid-crystalline polyester resin compound comprising a method for producing the wholly aromatic liquid-crystalline polyester resin.

According to one embodiment of the present invention, there is provided a method for producing a wholly aromatic liquid-crystalline polyester resin having homogeneous and excellent physical properties by including polycondensation of raw monomers using a metal acetate catalyst, and a process for producing the wholly aromatic liquid- A method for producing a wholly aromatic liquid-crystalline polyester resin compound can be provided.

Hereinafter, a method for producing a wholly aromatic liquid-crystalline polyester resin according to an embodiment of the present invention and a method for producing a wholly aromatic liquid-crystalline polyester resin compound including the method for producing the wholly aromatic liquid-crystalline polyester resin will be described in detail.

The method for producing a wholly aromatic liquid-crystalline polyester resin according to an embodiment of the present invention includes polycondensation of a starting monomer using a metal acetate catalyst.

The method for producing the wholly aromatic liquid-crystalline polyester resin may include, for example, the following steps:

(a) synthesizing a wholly aromatic liquid-crystalline polyester prepolymer by polycondensation of at least two raw monomers using a metal acetate catalyst; And

(b) synthesizing the wholly aromatic liquid-crystalline polyester resin by solid-phase polycondensation of the prepolymer.

The raw monomers used in the step (a) may include at least one compound selected from the group consisting of aromatic diols, aromatic diamines and aromatic hydroxyamines, aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids. In addition, the monomer may further include an aromatic aminocarboxylic acid.

As the synthesis method of the step (a), a solution polycondensation method or a bulk condensation polymerization method may be used. In order to accelerate the condensation reaction in the step (a), a monomer having increased reactivity (that is, an acylated monomer) pretreated with a chemical substance such as an acylating agent (particularly, an acetylating agent) may be used.

For the solid-phase polycondensation reaction in the step (b), suitable heat should be provided to the prepolymer. Examples of the method for providing the heat include a heating plate, hot air, and a high temperature fluid. In order to remove by-products from the solid-phase polycondensation reaction, it is possible to purge or remove by vacuum using an inert gas.

The amount of the metal acetate catalyst to be used may be, for example, 0.01 to 0.10 parts by weight based on 100 parts by weight of the total amount of the monomers. When the amount of the metal acetate catalyst is less than 0.01 part by weight based on 100 parts by weight of the total amount of the monomers, the amount of monomers to be sublimed in the polycondensation reaction step is increased and it is difficult to obtain a prepolymer having uniform physical properties. And the monomer is sublimated in the heat exchanger. In the severe case, the pipe is blocked, which makes the polycondensation reaction difficult. In order to remove the acid residual monomer, the cleaning cycle is shortened. When the amount exceeds 0.10 parts by weight, The amount of byproducts generated in the reaction step irregularly with time, and the physical properties of the resin and the compound are lowered, which is not preferable.

The nitric acid metal catalyst may include at least one member selected from the group consisting of magnesium acetate, potassium acetate, calcium acetate, zinc acetate, manganese acetate, acetic acid, antimony acetate and cobalt acetate. Hereinafter, the principle that a wholly aromatic liquid-crystalline polyester resin produced by polycondensation of raw monomers using a metal acetate catalyst can obtain uniform physical properties is described in detail.

As the raw monomers sublimated together with by-products are attached to the inner wall of the reactor, the heat exchanger and the pipe through which the by-product is discharged during the polycondensation reaction in the step (a), the synthesis of the wholly aromatic liquid-crystalline polyester prepolymer The molar ratio of the monomers used is different from the molar ratio of the raw monomers charged into the reactor. In addition, since the amount of the monomer to be sublimed varies with the elapse of the reaction time, the produced wholly aromatic liquid-crystalline polyester resin is not only heterogeneous but also has reduced physical properties. In addition, the resin compound made of the resin is also heterogeneous and has deteriorated physical properties.

However, in the case of using the metal acetate catalyst in the step (a), the polycondensation reaction rate is accelerated and the polycondensation reaction of the starting monomer proceeds even at a low temperature. Therefore, at the time when the temperature of the reactor reaches the sublimable temperature of the monomer, the amount of the remaining monomer is small and the total sublimation amount of the monomer can be minimized. Therefore, the wholly aromatic liquid-crystalline polyester resin produced according to one embodiment of the present invention has homogeneous and excellent physical properties, and the compound of the resin also has excellent mechanical properties and thermal properties.

In addition, the wholly aromatic liquid-crystalline polyester resin produced by the above method contains various repeating units in the chain, and may include, for example, the following repeating units:

(1) a repeating unit derived from an aromatic diol:

-O-Ar-O-

(2) a repeating unit derived from an aromatic diamine:

-HN-Ar-NH-

(3) repeating unit derived from aromatic hydroxyamine:

-HN-Ar-O-

(4) repeating unit derived from an aromatic dicarboxylic acid:

-OC-Ar-CO-

(5) repeating unit derived from an aromatic hydroxycarboxylic acid:

-O-Ar-CO-

(6) a repeating unit derived from an aromatic aminocarboxylic acid:

-HN-Ar-CO-

In the above formulas, Ar is an aromatic compound in which phenylene, biphenylene, naphthalene or two phenylene are bonded to carbon or a non-carbon element, or an aromatic compound in which phenylene, biphenylene, naphthalene, Or an aromatic compound in which one or more hydrogens among aromatic compounds bonded with non-carbon elements are replaced with other elements.

Another embodiment of the present invention provides a method for producing a wholly aromatic liquid-crystalline polyester resin compound comprising a method for producing the wholly aromatic liquid-crystalline polyester resin.

The method for producing a wholly aromatic liquid-crystalline polyester resin compound comprises the steps of: preparing a wholly aromatic liquid-crystalline polyester resin according to the above-described method for producing a wholly aromatic liquid-crystalline polyester resin; And kneading. For such melt kneading, a batch type kneader, a twin screw extruder or a mixing roll may be used. Further, for the purpose of smooth melt-kneading, an activator may be used for melt-kneading.

The additive may include at least one of an inorganic additive and an organic additive.

The inorganic additive may include glass fiber, talc, calcium carbonate, mica, or a mixture of two or more thereof, and the organic additive may include carbon fibers.

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

Example

Example 1: Preparation of a wholly aromatic liquid-crystalline polyester resin and a compound of the resin

24.4 kg of parahydroxybenzoic acid, 10.8 kg of biphenol, 7.3 kg of terephthalic acid and 2.4 kg of isophthalic acid were fed into a batch reactor of 100 liter capacity capable of controlling the temperature, and nitrogen gas was injected to inactivate the inner space of the reactor And 33 kg of acetic anhydride was further added to the reactor. Subsequently, in order to smoothly proceed the polycondensation reaction described later, 15 g of magnesium acetate and 3 g of potassium acetate were further added to the reactor. The reactor temperature was then raised to 150 ° C over 30 minutes and the alcohol functionality of the monomers was acetylated at this temperature for 3 hours . Next, the acetic acid produced in the acetylation reaction was removed, and the temperature of the reactor was elevated to 330 ° C over 6 hours to prepare a wholly aromatic liquid-crystalline polyester prepolymer by polycondensation reaction of monomers. In addition, acetic acid was further produced as a by-product in the preparation of the prepolymer. The acetic acid was also continuously removed during the preparation of the prepolymer together with the acetic acid generated in the acetylation reaction. Next, the prepolymer was recovered from the reactor and cooled and solidified. In addition, the total amount of the monomers sublimed in the above-mentioned production process was measured and the values thereof are shown in Table 1 below. Here, the total amount of the sublimed monomers was determined by summing up the amount of the monomers discharged together with the by-products and the amount of the monomers remaining in the reactor

Then, 20 kg of the wholly aromatic liquid-crystalline polyester prepolymer pulverized to an average particle diameter of 1 mm was introduced into a 100-liter capacity rotary kiln reactor, and nitrogen was continuously supplied at a flow rate of 1 Nm 3 / And the temperature was further raised to 320 ° C over 10 hours and maintained at that temperature for 3 hours to prepare a wholly aromatic liquid-crystalline polyester resin. Then, the reactor was cooled to room temperature over 1 hour, and the wholly aromatic liquid-crystalline polyester resin was recovered from the reactor.

Then, the prepared wholly aromatic liquid crystal polyester resin and glass fibers (pulverized glass fiber having a diameter of 10 mu m and an average length of 150 mu m) were mixed in a ratio of 6: 4 on a weight basis and fed to a twin-screw extruder (L / D: 40, diameter: 20 mm) to prepare a compound of wholly aromatic liquid-crystalline polyester resin. During the preparation of the resin compound, a vacuum was applied to the biaxial extruder to remove by-products.

Example 2: Preparation of a wholly aromatic liquid-crystalline polyester resin and a compound of the resin

A mixture of the wholly aromatic liquid-crystalline polyester resin and the resin was prepared in the same manner as in Example 1, except that the amounts of magnesium acetate and potassium acetate were changed to 50 g and 8 g, respectively. The total amount of the monomers sublimed in the process of manufacturing the wholly aromatic liquid-crystalline polyester resin was measured in the same manner as in Example 1, and the values are shown in Table 1 below.

Example 3: Preparation of a wholly aromatic liquid-crystalline polyester resin and a compound of the resin

A mixture of the wholly aromatic liquid-crystalline polyester resin and the resin was prepared in the same manner as in Example 1, except that magnesium acetate was not added and the addition amount of potassium acetate was changed to 3 g. The total amount of the monomers sublimed in the process of manufacturing the wholly aromatic liquid-crystalline polyester resin was measured in the same manner as in Example 1, and the values are shown in Table 1 below.

Example 4: Manufacture of a wholly aromatic liquid-crystalline polyester resin and the resin

A mixture of the wholly aromatic liquid-crystalline polyester resin and the resin was prepared in the same manner as in Example 1, except that the amounts of magnesium acetate and potassium acetate were changed to 75 g and 8 g, respectively. The total amount of the monomers sublimed in the process of manufacturing the wholly aromatic liquid-crystalline polyester resin was measured in the same manner as in Example 1, and the values are shown in Table 1 below.

Comparative Example 1: Manufacture of a wholly aromatic liquid-crystalline polyester resin and the resin

A mixture of the wholly aromatic liquid-crystalline polyester resin and the resin was prepared in the same manner as in Example 1, except that magnesium acetate and potassium acetate were not added at all. The total amount of the monomers sublimed in the process of manufacturing the wholly aromatic liquid-crystalline polyester resin was measured in the same manner as in Example 1, and the values are shown in Table 1 below.

Evaluation example

The melting point and melting temperature of each of the wholly aromatic liquid-crystalline polyester resins prepared in Examples 1 to 4 and Comparative Example 1 and the tensile strength of each of the wholly aromatic liquid-crystalline polyester resin compounds prepared in Examples 1 to 4 and Comparative Example 1 The strength, bending strength, impact strength, heat resistance temperature and blister resistance temperature were measured by the following methods, and the results are shown in Table 1 below.

(Measurement of physical properties of wholly aromatic liquid-crystalline polyester resin)

(1) Method of measuring melting temperature

The melting temperature was measured using a differential scanning calorimeter (TA Instruments, DSC 2910). The temperature at which the endothermic peak observed when the resin sample was heated from 40 ° C to 20 ° C / min was referred to as the _first melting temperature (Tm ₁ ), and the temperature was maintained at 30 ° C higher than Tm ₁ for 10 minutes, The temperature indicated by the observed endothermic peak when it was cooled to 40 deg. C under a reduced temperature of < RTI ID = 0.0 > 20 C / min. ≪ / RTI &

(2) Method of measuring melt viscosity

The melt viscosity was measured using a melt viscosity measuring apparatus (Rosand, RH2000) under a temperature of 1.0 mm x 32 mm capillary (melting temperature + 10 deg. C) and a shear rate of 1000 / s.

(Measurement of physical properties of all-aromatic liquid crystal polyester resin compound)

A specimen of each of the above-prepared all-aromatic liquid-crystalline polyester resin compounds was prepared using an injection machine (FANUC Co., Ltd., S-2000i 50B). The specimens were cooled to room temperature and left for 5 hours, (ASTM D638), flexural strength (ASTM D790), impact strength (ASTM D256), heat resistance temperature (ASTM D648), and blister resistance temperature were measured. The method of measuring the blister temperature was as follows.

<Method of measuring blister temperature>

A resin sample having a size of 10 mm x 64 mm x 1 mm was prepared. Subsequently, the specimen was immersed in and removed from a reaction vessel filled with lead and tin maintained at a temperature of 300 DEG C for 30 seconds. Thereafter, whether or not an expanded portion occurred on the surface of the specimen was visually observed. If there was no swelled portion on the surface of the specimen, the temperature of the reactor was raised by 5 ° C, and the above operation was repeated to confirm the temperature at which the expanded portion occurred in the specimen. Here, the maximum temperature at which no expanded portion is generated on the surface of the specimen is referred to as an inner blister temperature.

[Table 1]

Referring to Table 1, in the case of the production method of the wholly aromatic liquid-crystalline polyester resin of Examples 1 to 4, the total amount of the sublimed monomers was smaller than that of the wholly aromatic liquid-crystalline polyester resin of Comparative Example 1 Thus, the wholly aromatic liquid-crystalline polyester resin and the resin compound prepared in Examples 1 to 4 were superior to the wholly aromatic liquid-crystalline polyester resin prepared in Comparative Example 1 and the resin compound.

While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed 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 protection of the present invention should be determined by the technical idea of the appended claims.

Claims (5)

And polycondensation of the starting monomers using a metal acetate catalyst, Wherein the amount of the catalyst to be used is 0.04 to 0.13 parts by weight based on 100 parts by weight of the total amount of the monomers. The method according to claim 1, Synthesizing a wholly aromatic liquid-crystalline polyester prepolymer by polycondensation of at least two starting monomers using a metal acetate catalyst; And And synthesizing the wholly aromatic liquid-crystalline polyester resin by solid-phase polycondensation of the prepolymer. 3. The method of claim 2, The amount of the metal acetate catalyst to be used is 0.04 to 0.1 part by weight based on 100 parts by weight of the total amount of the monomers, The method according to claim 1, Wherein the nitric acid metal catalyst comprises at least one selected from the group consisting of magnesium acetate, potassium acetate, calcium acetate, zinc acetate, manganese acetate, acetic acid, antimony acetate and cobalt acetate. A process for producing a wholly aromatic liquid-crystalline polyester resin compound comprising the process for producing a wholly aromatic liquid-crystalline polyester resin according to any one of claims 1 to 4.