JPS6220525A - Production of elastic polyester - Google Patents

Abstract

PURPOSE:To economically obtain the titled polyester of outstanding color tone suitable for fibers, films, etc., by continuously feeding both lactone and crystalline aromatic polyester into a horizontal reaction vessel to carry out addition polymerization. CONSTITUTION:(A) A crystalline aromatic polyester (e.g., polyethylene terephthalate) constituted mainly by aromatic group as recurring unit is fed to mixer 1 using, e.g., a quantitative feeder such as gear pump; whereas, (B) a leactone (e.g., epsilon-caprolactone) is fed to the same mixer 1 in a similar manner so that the weight ratio A/B falls between 98/2-20/80. The resultant mixture is continuously fed through inlet 7 into horizontal reaction vessel 2 having revolving shaft 9 equipped with agitating blades 8 to perform addition polymerization so as not to develop gaseous phase within the vessel 2, thus obtaining the objective polyester via discharge valve 5. For removing the unreacted monomer, said monomer is discharged from monomer eliminator 3 through condenser 4.

Description

[Detailed description of the invention] (Industrial application field) The present invention has a crystalline aromatic polyester and lactones as main components, the crystalline aromatic octagroup polyester constitutes a hard segment, and the polylactone constitutes a soft segment. The present invention relates to a method for continuously producing elastic polyester, and more particularly, to a method for economically and continuously producing elastic polyester with excellent color tone.

(Prior art) Elastic polyester used for fibers, molding materials, and films has traditionally been manufactured by melting crystalline aromatic polyester chips and lactones in a batch process by heating and reacting them. Publication No. 4116, Special Publication No. 5
This is known from, for example, Japanese Patent No. 2-49037.

However, the batch method has the disadvantage that it is difficult to obtain a polymer with stable color tone, and it is also difficult to remove unreacted lactones, which causes the obtained polymer to have an odor. Furthermore, from the economic point of view, the batch method is disadvantageous in various respects.

Therefore, in order to solve the above-mentioned drawbacks, the present inventors have developed the most advantageous process and operating conditions, and obtained an excellent color tone by reducing the amount of carboxyl-terminated groups in the obtained polymer. As a result of intensive research and study, we discovered a method for addition polymerization by continuously supplying lactones and molten crystalline aromatic polyester to a reaction tank.

(Problems to be Solved by the Invention) However, when employing the above method, if a reaction tank installed substantially horizontally is used, the upper part of the reaction tank becomes a gas phase,
A situation in which a portion of the unreacted lactones supplied from the inlet moves to the gas phase, moves through the gas phase to the outlet side, and gets mixed into the addition-polymerized elastic polyester on the outlet side. happened. As a result, the quality of the elastic polyester discharged from the outlet was not constant, and the consumption amount of lactones as a raw material was also not constant.

(Means for Solving the Problems) In order to eliminate the above-mentioned drawbacks, the present inventors conducted various studies and finally completed the present invention.

That is, the present invention provides a method for producing an elastic polyester by reacting lactones with a crystalline aromatic polyester, in which the lactones and the molten crystalline aromatic polyester are placed in a horizontal reaction tank installed substantially horizontally. This is a method for producing elastic polyester characterized by addition polymerization by continuously supplying it in droplets.

In the present invention, the crystalline aromatic polyester is a pure polymer consisting mainly of ester bonds or ester bonds and ether bonds, which has at least one aromatic group as a main repeating unit and has a hydroxyl group at the end of the molecule. It is something. As a molding material, it is preferable to have a molecular fit of 5,000 or more, but in the case of a coating agent, the molecular fit is 5,000 or more.
It may be less than 15,000. To give a suitable specific example (
(mainly) homopolyesters such as polytetramethylene terephthalate or polyethylene prephthalate, poly 1,4-cyclohexylene dimethylene terephthalate, polyethylene/2,6-naphthalate, mainly consisting of tetramethylene terephthalate units or ethylene terephthalate units; Methylene isophthalate unit, ethylene isophthalate unit, tetramethylene adipate unit, tetramethine/sebacate unit, ethylene sebacate unit, 1,4-cyclohexylene dimethylsynterephthalate unit, tetramethylene-P-oxybenzoate unit, ethylene-P It may be a copolyester or a copolyester ether with a ff1 synthetic component such as -oxybenzoate unit.Also, as the lactone, e-caprolactone 7 is most preferred, but enantolactone, caprylolactone 7, etc. may also be used. Two or more of these lactones can also be used simultaneously.

The composition ratio of the crystalline aromatic polyester and lactone, type 7, is such that the aromatic polyester/lactone ratio is 98/2 to 20/2, considering the elastic properties of the resulting polymer.
80 (ffiffi ratio), particularly preferably 96/
4 to 30/70. ``The elastic polyester of the present invention may be obtained without a catalyst or with a catalyst.

All catalysts that are generally used in the polymerization of lactones can be used, and particularly preferred ones include lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, and keratinium. These include metals such as tin, lead, antimony, arsenic, cerium, boron, cadmium, 77g, metals such as gold silk compounds, organic acid salts, alfuxites, etc. Particularly preferred are tin organoaluminum and organotitanium compounds, such as diacyl stannous, tetraacyl tin, dibutyltin oxide, dibdeltin dilaurate, tin dioctanoate, tin tetraacetate, triimbutylaluminum, and tetrabutyltin. These include titanium, germanium dioxide, and antimono dioxide. These catalysts are 2! ! The above may be used in combination.

These catalysts are generally used as polymerization catalysts for aromatic polyesters, but they can be added simultaneously during the polymerization of the aromatic polyester, or partially added during the polymerization of the aromatic polyester. One method is to add the remainder during lactone polymerization. The amount of the catalyst used is 0 to 0.0% based on the total amount of aromatic polyester and lactone.
2% by weight, especially 0.001-0.1% by weight is preferred.

The reaction temperature i is set to be at least the temperature at which the mixture of aromatic polyester and lactone melts uniformly, and at least the melting point of the produced elastic polyester.

As a method of supplying a crystalline aromatic polyester and lactones to a horizontal reaction tank, (1) the crystalline aromatic polyester is directly and continuously supplied in a molten state after the polymerization reaction in the production of the polyester; Method: (1) After the polymerization reaction in the production of the polyester, the crystalline aromatic polyester is once molded into chips, and then melted and continuously supplied. (1) Lactones are added to the crystalline aromatic polyester chips. (4) A method of mixing crystalline polyester and lactones which have been melted in advance and then continuously supplying both can be adopted.

Further, in the method of the present invention, when employing the above method, it is necessary to continuously supply the lactones and the crystalline aromatic polyester so as to fill the horizontal reaction tank. Filling means that substantially no gas phase is created within the reaction tank. This is because if there is a gas phase, unreacted lactones will pass through the gas phase and mix into the addition-polymerized elastic polyester, which is undesirable.

Next, an embodiment of the method of the present invention will be described with reference to the drawings.

FIG. 1 is a flow sheet showing an embodiment of the method of the present invention.

First, the molten aromatic polyester is supplied to the mixer 1 using a quantitative supply device such as a gear pump, and on the other hand, the pre-heated lactone is also quantitatively supplied to the mixer! supplied to The mixer 1 is kept at a temperature at which the polyester and lactone do not solidify. Next, the mixture discharged from the mixer 1 is continuously supplied to the horizontal reaction tank 2. After the mixture is subjected to addition polymerization for a predetermined time in the horizontal reaction tank 2, it is taken out via the discharge valve 5. When further demonomerization is performed, it is supplied following step 3 after demonomerization. Incidentally, unreacted monomer is discharged through a condenser 4, and the polymer after demonomerization is taken out through a discharge valve 6.

FIG. 2.3 is a schematic cross-sectional view of the horizontal reaction tank 2. FIG. 2 shows an example of an actual tM embodiment of the method of the present invention. In FIG. The rotation of the rotary shaft 9 causes addition polymerization, and the resulting elastic polyester is discharged from the discharge port 1.
Unreacted lactone supplied from the lower portion 0 passes through the gas phase portion 11 without being reacted, is mixed into the elastic polyester after addition polymerization, and is discharged.

The horizontal reaction tank used in the method of the present invention is equipped with 10 or more rotating shafts equipped with stirring blades, and the reaction tank has various cross-sectional shapes such as circle, ellipse, cocoon shape, and heart shape. things are adopted.

The conditions for carrying out the method of the present invention are not limited;
It is preferable to heat to 00 to 230°C, especially 150 to 210°C. Next, the addition reaction between the molten crystalline aromatic polyester and the lactones is carried out at normal pressure or under pressure, with an fA degree of 210 to 260°C, preferably 215 to 2.
Average residence time at 45°C 30 minutes to 6 hours, preferably 1 to 6 hours
It is 3 hours. When further demonomerizing, 50 Torr
It is preferable to hold the mixture under the following vacuum at a temperature above the melting point for an average of 1 to 30 minutes.

Note that additives such as antioxidants may be blended before the addition polymerization reaction and when the aromatic polyester and lactone are mixed.

('j!Example) The present invention will be specifically explained below using Examples and Reference Examples, but the present invention is not limited thereto.

In addition, in the examples, the reduced specific viscosity and the amount of terminal carboxyl groups were measured according to the following procedure.

(1) Reduced specific viscosity Measured under the following conditions Solvent: Phenol/tetrachloroethane Weight, ratio
6/4 Concentration: 50■/25■ Temperature = 30℃ (21 Unreacted Laughton Monomer Content 5g of the produced elastic polyester chips and 150σ carbon tetrachloride were placed in an Erlenmeyer flask with a cooling tube, and zeolite was added. ,
After heating under reflux for 3 hours to extract unreacted lactone monomer in the chips, the carbon tetrachloride liquid is separated. Shimadzu G
Using a C-7A gas chromatogram, the concentration of unreacted lactone monomer in carbon tetrachloride was determined, and from this concentration, the concentration of unreacted lactone monomer in the elastic polyester chip was determined by calculation.

(3) Black carbide amount Take 250g of elastic polyester chips, and
The number of black carbides with a size of 00μ or more was visually checked.

Example 19, z Melted polytetramethylene lentilic acid chips (reduced specific viscosity [fl, 13Q) 70 parts, ε-caprolact 7
30 parts of ionox and 330.0.2 parts of ionox were continuously supplied to fill the horizontal reaction tank shown in FIG.
Addition polymerization reactions were carried out by staying at 230°C for an average of 90 minutes and 120 minutes, respectively.

Table 1 shows the reduced specific viscosity, unreacted lactone amount, and black carbide content of the resulting elastic polyester.

Comparative Example 10.2 Example 1. , vL shown in FIG. 3 with the gas phase part
All the procedures were as in Example 1 except that a type reactor was used. I did the same thing.

The results are also listed in Table 1.

Table 1 As is clear from Table 1, when a horizontal reaction tank with a gas phase section is used, the viscosity of the obtained elastic polyester is lower, and the amount of unreacted lactone and black carbide content is also higher. . (Effects of the Invention) By adopting the method of the present invention having the above-mentioned configuration, the operation of the equipment becomes much easier, the additional assembly time is shortened, and the quality is consistently excellent with good color tone and no monomer odor. An elastic polyester can be obtained. In addition, the obtained elastic polyester has excellent rubber elasticity, and has excellent flexibility, light resistance, and heat resistance, so it can be used as impact-resistant molded products and d-fibers, or as an impact modifier when mixed with other resins. It can be used as a plasticizer, plasticizer, etc. By adding various additives such as ultraviolet absorbers, heat stabilizers, lubricants, pigments, and mold release agents, its uses can be further expanded. .

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing an embodiment of the method of the present invention. FIG. 2 is a schematic sectional view of a horizontal reaction tank according to an embodiment of the method of the present invention, and FIG. 3 is a comparative example of the method. In Figures 1 to 3, 1 is a mixing tank, 2 is a horizontal reaction tank, and 7 is a mixing tank.
10 is a supply port, 10 is a discharge port, and 11 is a gas phase portion. Patent Applicant: Toyo Bosei Co., Ltd. Figure 2 Figure 8 Figure 7;

Claims (5)

[Claims] (1) In the method of producing elastic polyester by reacting lactones and crystalline aromatic polyester, lactones and molten crystalline aromatic polyester are placed in a horizontal reaction tank installed substantially horizontally, A method for producing elastic polyester characterized by addition polymerization by continuously supplying the polyester so as to fill the material. (2) Crystalline aromatic polyester supplied to the reaction tank,
Claim (1) characterized in that the polyester is supplied directly in a molten state after the polymerization reaction in the production of the polyester.
Method for producing elastic polyester as described in Section 1. (3) Crystalline aromatic polyester supplied to the reaction tank,
The method for producing an elastic polyester according to claim 1, wherein after the polymerization reaction in producing the polyester, the polyester is formed into chips and then melted and supplied. (4) The crystalline aromatic polyester and lactones to be supplied to the reaction tank are supplied by adding the lactones to the crystalline aromatic polyester chips, and then melting the chips. A method for producing elastic polyester as described in (1). (5) Claim (1) characterized in that the crystalline aromatic polyester and lactones are mixed in advance before the crystalline aromatic polyester and lactones are supplied to the reaction tank. A method for producing the described elastic polyester.