JPH0521134B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention continuously produces an elastic polyester whose main components are a crystalline aromatic polyester and lactones, and in which the crystalline aromatic polyester constitutes a hard segment and the polylactone constitutes a soft segment. The present invention relates to a method, and more particularly, to a method for economically and continuously producing elastic polyester with excellent color tone. (Prior Art) Elastic polyesters used for fibers, molding materials, and films have traditionally been produced by heating and melting crystalline aromatic polyester chips and lactones in a batch process to react. Kimiaki
It is known from Japanese Patent Publication No. 48-4116, Japanese Patent Publication No. 52-49037, etc. 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, the present inventors, in order to solve the above-mentioned drawbacks,
In addition, as a result of intensive research and study to find the most advantageous process and operating conditions and to reduce the content of carboxyl end groups in the obtained polymer and obtain excellent color tone, we have found that crystalline aromatic polyester fused with lactones We have discovered a method for addition polymerization by continuously supplying and polymerizing to a reaction tank. (Problem 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, and the unreacted gas supplied from the inlet becomes a gas phase. A situation occurred in which some of the lactones moved to the gas phase, moved through the gas phase to the outlet side, and were mixed into the addition-polymerized elastic polyester on the outlet side. 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 and a crystalline aromatic polyester, in which the lactones and the molten crystalline aromatic polyester are heated at an angle of substantially 5° to 90° with respect to the horizontal axis. This is a method for producing elastic polyester, which is characterized in that addition polymerization is carried out by continuously supplying the polyester to a reaction tank which is installed so as to have an outlet at the bottom and has an outlet at the bottom. In the present invention, the term "crystalline aromatic polyester" refers to a polymer mainly composed 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. The molding material preferably has a molecular weight of 5,000 or more, but the coating agent may have a molecular weight of less than 5,000. Preferred specific examples include (mainly) homopolyesters such as polytetramethylene terephthalate or polyethylene terephthalate, poly 1,4-cyclohexylene dimethylene terephthalate, polyethylene 2,6-naphthalate, mainly consisting of tetramethylene terephthalate units or ethylene terephthalate units, etc. Tetramethylene isophthalate unit, ethylene isophthalate unit, tetramethylene adipate unit, tetramethylene sebacate unit, ethylene sebacate unit,
These include copolymerized polyesters or copolymerized polyester ethers with copolymerized components such as 1.4-cyclohexylene dimethylene terephthalate units, tetramethylene-P-oxybenzoate units, and ethylene-P-oxybenzoate units. Further, as the lactone, ε-caprolactone is most preferable, but enantolactone, caprylolactone, etc. may also be used. Two or more of these lactones can also be used simultaneously. The above-mentioned composition ratio of the crystalline aromatic polyester and lactones is such that the ratio of aromatic polyester/lactone is 98/
2 to 20/80 (weight 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. As the catalyst, all those commonly used for polymerization of lactones can be used, and particularly preferred ones include lithium, sodium, potassium, cesium, magnesium,
Calcium, barium, strontium, zinc,
These include metals such as aluminum, titin, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, anganese, and their organometallic compounds, organic acid salts, and alkoxides. Particularly preferred are organotin organoaluminum and organotitanium compounds, such as diacyl stannous, tetraacyl stannous, dibutyltin oxide, dibutyltin dilaurate, tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanium, These include germanium dioxide and antimony trioxide. Two or more of these catalysts may be used in combination. This catalyst is generally used as a polymerization catalyst for aromatic polyester, but it can be added at the same time as the aromatic polyester is polymerized, or a part of it can be added during the aromatic polyester polymerization and the rest can be added. There is a method of adding lactone during polymerization. The amount of the above catalyst used is 0 to 0.2% by weight based on the total amount of aromatic polyester and lactone, especially
0.001-0.1% by weight is preferred. The reaction temperature is higher than the temperature at which the mixture of aromatic polyester and lactone is uniformly melted and higher than the melting point of the produced elastic polyester. The method of supplying the crystalline aromatic polyester and lactones to the horizontal reaction tank includes (1) a method of directly and continuously supplying the crystalline aromatic polyester in a molten state after the polymerization reaction in the production of the polyester; (2) A method in which crystalline aromatic polyester is once formed into chips after the polymerization reaction in the production of the polyester, and then melted and continuously supplied; (3)
A method in which lactones are added to crystalline aromatic polyester chips, then melted and both are continuously supplied. (4) A method in which pre-melted crystalline polyester and lactones are mixed and then both are continuously supplied. It is possible to adopt methods such as 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,
Preheated lactone can also be quantitatively mixed in mixer 1.
is 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 reaction tank 2. After the mixture is subjected to addition polymerization for a predetermined time in the reaction tank 2, it is taken out via the discharge valve 5. If further demonomer is to be carried out, it is subsequently supplied to the demonomer machine 3. Incidentally, unreacted monomer is discharged through a condenser 4, and the polymer after demonomerization is taken out through a discharge valve 6. 2 and 3 are schematic cross-sectional views of the reaction tank 2. FIG. FIG. 2 shows a horizontal reaction tank according to a comparative example. In FIG. is stirred by rotation and addition polymerized, and the obtained elastic polyester is discharged from the discharge port 10. Note that there is a gas phase part 11 in the upper part of the tank, and unreacted lactone supplied from the supply port 7 passes through the gas phase part 11 without being reacted, and is mixed into the elastic polyester after addition polymerization and discharged. Ru. FIG. 3 shows an example of an embodiment of the reaction vessel used in the method of the present invention, and is installed so as to have an angle of substantially 90° with the horizontal axis, but the present application is not limited thereto. It may have an angle of 45° to 90°, preferably 45° to 90°. In FIG. 3, the lactone and the molten aromatic polyester are fed into the supply port 7.
After being stirred, the elastic polyester obtained by addition polymerization is discharged from the discharge port 10. In the present invention, it is preferable to fill and supply the tank so that there is no gas phase, but even if there is a gas phase in the upper part of the tank, the gas phase is not continuous to the outlet. Therefore, unreacted lactone will not be mixed into the elastic polyester. Also, the third
In the figure, the water is supplied so as to flow from top to bottom, but it may also be supplied from the bottom to the top, that is, from the discharge port 10 and discharged from the supply port 7. The reaction tank used in the method of the present invention is equipped with one or more rotating shafts equipped with stirring blades, and the cross-sectional shape of the reaction tank can be various, such as circular, elliptical, cocoon-shaped, heart-shaped, etc. will be adopted. Although the conditions for carrying out the method of the present invention are not limited, it is preferable that the lactone is supplied as it is or that it is previously heated to about 100 to 230°C, particularly 150 to 210°C. Next, the addition polymerization reaction between the molten crystalline aromatic polyester and lactones is carried out under normal pressure or increased pressure at a temperature of 210 to 260°C, preferably 215 to 245°C, for an average residence time of 30 minutes to 6 hours, preferably 1 ~3 hours. Further, when demonomerizing, it is preferable to hold the monomer under a vacuum of 50 Torr or less and 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. (Examples) The present invention will be specifically explained below using Examples and Comparative 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 mg/25 ml Temperature: 30°C (2) Content of unreacted raftone monomer Manufactured elastic polyester chips 5g and 150c.c.
Carbon tetrachloride is placed in an Erlenmeyer flask equipped with a cooling tube, zeolite is added thereto, the mixture is heated under reflux for 3 hours to extract unreacted lactone monomers in the chips, and then the carbon tetrachloride liquid is separated. Using a GC-7A gas chromatogram manufactured by Shimadzu Corporation, 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) Amount of black carbide 250 g of elastic polyester chips were taken, and the number of black carbides with a size of 100μ or more in the chips was visually determined. Examples 1 to 3 70 parts of melted polytetramethylene terephthalate chips (reduced specific viscosity 1.130), 30 parts of ε-caprolactone, and 0.2 parts of Ionox 330 were continuously filled into the reaction tank shown in FIG. The addition polymerization reaction was carried out at 230°C for an average of 90 minutes, 120 minutes, and 180 minutes, respectively. the result,
Table 1 shows the reduced specific viscosity, unreacted lactone amount, and black carbide content of the obtained elastic polyester. Comparative Examples 1 and 2 In Example 1, everything was the same as in Example 1 except that a horizontal reactor shown in FIG. 2 having a gas phase section was used. The results are also listed in Table 1. Examples 4 to 6 Everything was the same as in Example 1 except that the same reaction tank shown in FIG. 3 was used in Example 1, and a gas phase portion was present in the upper part. The results are also listed in Table 1.

[Table] 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 becomes lower, and the amount of unreacted lactone and black carbide content are also increased. (Effects of the Invention) By adopting the method of the present invention having the above configuration, the operation of the device becomes much easier,
Addition polymerization time is shortened, and it is possible to obtain an excellent elastic polyester with a good color tone, no monomer odor, and constant quality. 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 fibers, or as an impact modifier when mixed with other resins. , useful as a plasticizer, etc. Furthermore, various additives such as ultraviolet absorbers, heat stabilizers, lubricants,
By adding pigments, release agents, etc., 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 reaction tank in a comparative embodiment, and FIG. 3 is a schematic sectional view of a reaction tank in an embodiment of the method of the present invention. In FIGS. 1 to 3, 1 is a mixing tank, 2 is a reaction tank, 7 is a supply port, 10 is a discharge port, and 11 is a gas phase section.

Claims (1)

[Claims] 1. A method for producing an elastic polyester by reacting a crystalline aromatic polyester with lactones, in which the lactones and the molten crystalline aromatic polyester are heated substantially at an angle of 5° to a horizontal axis. A method for producing elastic polyester, characterized in that addition polymerization is carried out by continuously supplying it to a reaction tank installed at a 90° angle and having an outlet at the bottom. 2. The crystalline aromatic polyester to be supplied to the reaction tank is subjected to a polymerization reaction in the production of the polyester,
2. The method for producing elastic polyester according to claim 1, wherein the elastic polyester is directly supplied in a molten state. 3. The crystalline aromatic polyester to be supplied to the reaction tank is subjected to a polymerization reaction in the production of the polyester,
2. The method for producing elastic polyester according to claim 1, wherein the elastic polyester is supplied after being molded into chips and then melted. 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. The method of manufacturing the elastic polyester described. 5. The elastic polyester according to claim 1, wherein the crystalline aromatic polyester and lactones are mixed in advance before supplying the crystalline aromatic polyester and lactones to the reaction tank. manufacturing method.