JPS61281124A - Continuous production of elastic polyester - Google Patents

Abstract

PURPOSE:To economically produce a polyester having improved hue without monomer smell, by feeding continuously a molten crystalline aromatic polyester and lactone to a reaction tank and carrying out addition polymerization. CONSTITUTION:A molten crystalline aromatic polyester and lactone are continuously fed to a reaction tank to carry out addition polymerization. The unreacted lactone is then continuously removed from the resultant elastic polyester. The above-mentioned polyester and lactone are continuously fed to the reaction tank by a method for continuously feeding the crystalline aromatic polyester after the polymerization reaction in the production of the polyester directly in the molten state or molding the polyester into chips, melting the chips and feeding the resultant melt, etc. Alternatively, the premelted two components are mixed and fed to the reaction tank.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention comprises a crystalline aromatic polyester and lactones as main components, the crystalline aromatic 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 specifically, 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 heating and melting crystalline polyester chips and lactones in a batch process to react. Official Gazette, Special Publication 1972-
This is known from, for example, Japanese Patent No. 49037.

(Problems to be Solved by the Invention) However, the batch method described above has the disadvantage that it is difficult to obtain a polymer with stable color tone, and it is difficult to remove unreacted lactones, which causes the odor of the obtained polymer. It became. Furthermore, from the economic point of view, the batch method is disadvantageous in various respects.

(Means for Solving the Problems) Therefore, in order to solve the above-mentioned drawbacks, the present inventors have determined the most advantageous process and operating conditions and the content of carboxyl end groups in the obtained polymer. As a result of intensive research in order to reduce the amount of water and obtain excellent color tone, we have finally completed the present invention. That is, the present invention provides a method for producing an elastic polyester by reacting a crystalline aromatic polyester and lactones, in which the molten crystalline aromatic polyester and lactones are continuously supplied to a reaction tank for addition polymerization. This is a continuous manufacturing method for elastic polyester.

In the present invention, crystalline aromatic polyester is a polymer mainly composed of ester bonds or ester bonds and ether bonds, having at least 1 gi of aromatic groups as the main repeating unit, and having a hydroxyl group at the end of the molecule. It is something. The molding material preferably has a molecular ff of 15,000 or more, but in the case of a coating agent, it may have a molecular ff of 15,000 or less. Preferred specific examples include (mainly) polytetramedyle/terephthalate or polyethylene terephthalate, poly 1,4-cyclohexylene dimethylene terephthalate, polyethylene λ6-
Homopolyester such as naphthalate, mainly consisting of tetramethylene terephthalate units or ethylene terephthalate units, and also tetramethylene isophthalate units, ethylene isophthalate units, tetramethylene adipate units, tetramethylene sebacate units, ethylene sebacate units, These include copolymerized polyesters, copolymerized polyesters, and ester ethers with copolymerized components such as 1.4-cyclohexylene dimethylene terephthalate units, tetramethine y-p-benzony) units, and ethylene-P-oxybenzoate units.

Further, as the lactone, ε-caprolactone is most preferable, but ena/tralactone, caprylolactone 7, etc. may also be used. Two or more of these lactones can also be used simultaneously.

The composition ratio of the above-mentioned crystalline aromatic polyester and lactones is such that the ratio of aromatic polyester/lactone is 98/2 to 20/80 (in view of the elastic properties of the resulting polymer).
ffIffi ratio), 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 for polymerization of lactones can be used, and particularly preferred ones include lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, and germanium. , tin, lead, antimony, arsenic, cerium, boron,
These include gold-metallic compounds such as cadmium and manganese, ametallic acid salts, alphoxides, and the like.

Particularly preferable ones include “a tin organoaluminum,
Organic titanium compounds such as quacyl stannous, tetraacyl stannous, diptyltin oxide, dibutyltin dilaurate, tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanium, germanium dioxide, antimony dioxide, and the like. Two or more of these catalysts may be used in combination.

These catalysts are generally used as heavy metal catalysts for aromatic polyesters. There is a method of adding lactone during polymerization.

The amount of the catalyst used is 0 to 0.2% by weight, especially 0.001 to 0.0% by weight, based on the total amount of aromatic polyester and lactone.
, If! ff1% is preferable. 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 block copolymer.

As a method of supplying the crystalline aromatic polyester and lactones to the addition polymerization tank, (1) a method of continuously supplying the crystalline aromatic polyester directly 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) Lactones are added to crystalline aromatic polyester chips. After mixing the molten crystalline polyester and lactones, a method of melting the polyester and continuously supplying the two can be adopted.

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

FIG. 1 is a 70-sheet showing an example of an embodiment of the method of the present invention.

First, melt the aromatic polyester into a gear pump, etc.
In feed '212, the mixer 1 is fed, while the preheated lactone is also fed quantitatively to the mixer 1. The mixer 1 is maintained at a temperature at which the polyester and lactone do not solidify. Next, the mixture discharged from the mixer 1 is continuously supplied to an addition polymerization tank 2. After the mixture is subjected to addition polymerization for a predetermined time in the addition polymerization tank 2, it is taken out via the discharge valve 5. Q to carry out further demonomerization
In this case, demonomerization [3] is followed by demonomerization. Incidentally, unreacted monomer is discharged through a condenser 4, and the polymer after demonomerization is taken out through a discharge valve 6.

The conditions for carrying out the method of the present invention include, but are not limited to, the lactone supplied as is or in advance. It is preferable to heat it to 00 to 230°C, particularly 150 to 210°C. Next, the addition polymerization reaction between the molten crystalline aromatic polyester and lactones is carried out at normal pressure or under pressure a.
pressure, temperature 210-280°C, preferably 215-240°C
Average residence time at 5°C 30 minutes to 6 hours, preferably 1 to 3
It's time. Further, when removing the monomer, it is preferable to hold the monomer under a vacuum of 50 orr or less at a temperature below the melting point for an average of 1 to 30 minutes.

Note that additives such as antioxidants may be blended when the aromatic polyester and Lacto 7 are mixed before the addition polymerization reaction.

(Examples) 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/TCE Weight ratio 6/4 b:J degree: 50/25-30°C (2) Terminal carboxyl group amount Polyester in the container Elastic body 100 and benzyl alcohol 10*e were taken and dissolved at 200° C. in an HF oven without stirring. The dissolution time was set to 2 minutes, 4 minutes, and 6 minutes, and after each dissolution, the solution was cooled with water and diluted with chloroform 101. The amount of carboxyl groups at each dissolution time was obtained by titrating the solution with a 0.1N caustic soda-benzyl alcohol solution using phenolphthalene as an indicator. From these values, an extrapolated value at a dissolution time of 0 minutes was determined and determined as the amount of terminal carboxyl groups.

(3) Color tone Measured using a color difference meter manufactured by Nippon Denshoku Kogyo ■.

Example 1 Polytetramethylene terephthalate chips (reduction ratio f+
'; degree 1. +30) with an extruder HiM L,
Polytetramethylene terephthalate chips, 730 parts of C-caprolact, and 330.0.2 parts of Io/Tux were continuously and directly supplied to an addition polymerization tank, and an addition polymerization reaction was carried out at 230° C. for an average residence time of 120 minutes. The resulting elastic polyester has a reduction ratio Ll'1. It was I74.

Example λ 100 parts of terephthalic acid, 8 parts of tetramethylene glycol
A slurry mixture of 2 parts of tetrabutyl titanate and 0.1 part of tetrabutyl titanate is continuously fed to an esterification reactor to undergo an esterification reaction, and then a prepolymerization reaction is performed in a prepolymerization reactor to form a prepolymer. was supplied to the final m container, and a polymerization reaction was carried out under the conditions of a reaction temperature of 245°C and a reaction pressure of 0.5 parts m11 g to obtain polydetoshimedylene/prephthalate having a reduced specific viscosity of 1.06. This polymer was directly passed through a Nigu, and in the Nigu, a mixture of 70 parts of polytetramethylene terephcrate, 730 parts of caprolact, and 0.2 parts of Iononox 130 was continuously added to the i.1 polymerization vessel. The addition polymerization reaction was carried out by staying at 230° C. for an average of 120 minutes. The resulting elastic polyester had a reduced specific viscosity of 1.1:to.

Example, Example 1. 85 parts of the same polytetramethylene terephthalate chips, 15 parts of ε-caprolactone, and 2 parts of Ionox 330 α were placed in a kettle, mixed, melted, and continuously fed to an addition polymerization tank to produce an average of 1
The mixture was allowed to stay for 20 minutes to carry out an addition polymerization reaction. The resulting elastic polyester had a reduced specific viscosity of 1.07.

Example 4゜Example 1. Melt the same polytetramethylene terephthalate chips with an extruder, add 70 parts of the melted polytetramethylene derephthalate, turn over ε-I Lacto 7
30 parts of ionox and 3300.2 parts of ionox were continuously fed directly to the addition polymerization tank, and an average of 120 parts of
The mixture was allowed to stay for a minute to carry out an addition polymerization reaction.

Then, unreacted caprolactone was continuously removed in a molten state using a thin film demonomer machine under vacuum at I Torr. The resulting elastic polyester has a reduced specific viscosity of 1.
It was 108.

Comparative Example 1 Polytetramethylene terephthalate chips (reduced specific viscosity 1.130) were placed in a batch addition polymerization vessel equipped with a stirrer.
0 parts, 30 parts of Recaprolactone, and 0.2 parts of Ionox 330 were charged, and after sufficiently purging with nitrogen gas, the temperature was raised to 230°C with stirring, and a melt reaction was performed at 230°C for 2 hours. The resulting elastic polyester had a reduced specific viscosity of 1.11'30.

Comparative Example 2 Comparative Example 1. 85 parts of polytetramethylene terephthalate chips, 15 parts of ε-caprolactone, and 0.2 parts of Ionox 330 were added to Comparative Example 1. An elastic polyester was obtained by reacting in the same manner as above. The resulting polymer had a reduced specific viscosity of 1.000.

Comparative Example & Polytetramethylene/terephthalate tochinob ('E1 original specific viscosity 1.130) was added to a batch-type addition m container equipped with a stirrer.
After sufficiently purging with nitrogen gas, the temperature was raised to 230° C. with stirring to dissolve the polytetramethylene terephthalate chips.

730 parts of 9-caprolact and 3300.2 parts of ionox were charged under a nitrogen gas atmosphere, and a melt reaction was carried out for 2 hours while stirring at 230°C. The reduced specific viscosity of the obtained elastic polyester was 0.920.

Comparative Example 4 70 parts of the same polytetramethylene terephthalate chips as in Comparative Example &, 730 parts of 5-caprolact and 2 parts of Ionox 330 α were reacted in the same manner as in Comparative Example a.

Unreacted caprolactone was then removed under vacuum at I Torr for 60 minutes. The resulting elastic polyester had a reduced specific viscosity of 0.920.

The terminal carboxyl group weight and color tone of the elastic polyester chips obtained in Reference Example 1, Examples 1 to 4, and Comparative Examples 1 to 3 were measured. The results are shown in Table-1.

Reference example 2 Example 4. The terminal carboxyl groups and color "J" of the elastic polynisglu chip obtained in Comparative Example 4 were measured, and the presence of any bad odor due to residual C-caprolactone was also investigated. The results are shown in Table-2.

Table 1 Table 2 As is clear from Tables 1 and 2, the elastic polyester obtained by the method of the present invention has a terminal strength of 72 or less and a color tone of ■.

Value 70 or higher 1-1b value 1], and when further demonomerized, the remaining -caprolactone becomes 470PP■,
It can be seen that I is much lower than +00 ppm obtained by the batch method.

(Effects of the Invention) By adopting the method of the present invention having the configuration described above, the equipment operation becomes much easier, the addition polymerization time and the time required for demonomer removal are shortened, and the color tone is good and there is no monomer odor. An elastic polyester can be obtained.

In addition, the obtained elastic polyester has excellent rubber elasticity, 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. It is used as a plasticizer, etc. Furthermore, various additives such as ultraviolet absorbers, heat stabilizers, lubricants, pigments, W
NY! :J, agents, etc. can be added to further expand its uses.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an embodiment of the method of the present invention. In FIG. 1, 1 is a mixer, 2 is an addition polymerization tank, 3 is a demonomer machine, and 4 is a condenser. Patent applicant: Toyobo Co., Ltd. Figure

Claims (6)

[Claims] (1) A method for producing elastic polyester by reacting a crystalline aromatic polyester and lactones, characterized in that the molten crystalline aromatic polyester and lactones are continuously supplied to a reaction tank for addition polymerization. Continuous production method for elastic polyester. (2) A continuous method for producing an elastic polyester according to claim (1), characterized in that unreacted lactones are continuously removed from the elastic polyester obtained by addition polymerization. (3) 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.
Continuous production method of elastic polyester as described in . (4) Crystalline aromatic polyester supplied to the reaction tank,
A continuous 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. (5) The crystalline aromatic polyester and lactones are supplied to the reaction tank by adding the lactones to the crystalline aromatic polyester chips, and then melting the chips and supplying them. (1) Continuous production method of elastic polyester as described in section (1). (6) 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. Continuous production method of elastic polyester as described.