JPH02302428A - Production of elastic polyester - Google Patents

Abstract

PURPOSE:To obtain the subject polymer, having stabilize quality, excellent in heat-and weather-resistance, etc., and suitable as automotive parts, etc., by carrying out addition polymerization of a crystalline aromatic polyester with a lactone compound in a continuous stirring mixer capable of performing specific mixing operation. CONSTITUTION:(A) A crystalline aromatic polyester, such as polyethylene terephthalate, and (B) a lactone compound, such as epsilon-caprolactone, are fed to a continuous stirring mixer, having a screw with many interrupted ridges coaxial with a barrel therein and operating so as to mesh the interrupted parts with teeth protruding on the inner surface of the barrel and reacted preferably at 210 to 280 deg.C to afford the objective polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is directed to a novel method for producing an elastic polyester using an aromatic polyester as a hard segment and an aliphatic polyester polylactone as a soft segment.

More specifically, the present invention relates to a method for economically producing elastic polyester of stable quality using a special reaction apparatus.

<Prior art> A polyester-polyester type block copolymer in which aromatic polyester such as polybutylene terephthalate constitutes a hard segment and polycaprolactone constitutes a soft segment has high tensile strength, tear strength, flex fatigue resistance, As a thermoplastic elastomer with excellent heat resistance, it is widely used in automobile parts, electrical/electronic parts, mechanical parts, etc.

This polyester polyester block copolymerization type elastic polyester is manufactured by melt-mixing and reacting a crystalline aromatic polyester and a lactone compound, and is disclosed in Japanese Patent Publication No. 48-4116 and Japanese Patent Publication No. 52-49037. Publication, JP-A-61-281124, JP-A-61-283619, JP-A-61-
No. 287922, Japanese Patent Application Laid-open No. 62-20525,
JP-A-62-27425, JP-A-62-5333
It is known from Publication No. 6.

<Invention tries to solve! ! However, in the method of the above-mentioned known example, the reaction time is long, and the aromatic polyester constituting the hard segment and the polylactone constituting the soft segment are partially randomized due to the transesterification reaction, resulting in poor melting point, surface hardness, mechanical strength, etc. The problem was that only elastic polyesters with large fluctuations could be produced.

<Means for Solving rIRll> Therefore, the present inventors conducted intensive studies to solve the above-mentioned t5B and economically obtain an elastic polyester with stable quality, and as a result, they arrived at the present invention.

That is, in the present invention, a crystalline aromatic polyester and a lactone compound are placed in a barrel, and a screw is provided coaxially with the barrel and has a large number of interrupted ridges, and the screw is operated so that the interrupted portions mesh with teeth protruding from the inner surface of the barrel. The present invention provides a method for producing elastic polyester, which is characterized in that it is supplied to a continuous stirring mixer and subjected to continuous addition polymerization.

The crystalline aromatic polyester used in the present invention is defined as having at least lf! in the main repeating unit. Polyethylene terephthalate, polybutylene terephthalate, poly1. 4-
Examples include cyclohexylene dimethylene terephthalate, polyethylene 2,6-naphthalate, polybutylene 2,6-naphthalate, etc., but mixtures of these polyesters and these polyesters further include isophthalic acid units, adipic acid, sebacic acid, dodecanedioic acid, etc. A copolymerized polyester in which aliphatic dicarboxylic acid units, p-oxybenzoic acid units, etc. are copolymerized can also be used.

Among them, polybutylene terephthalate is particularly preferably used because it has excellent crystallinity.

The relative viscosity (ηr) of the crystalline aromatic polyester used in the present invention is 0
．． Value measured at 25°C for 5% polymer solution, 1.2
in the range of 0 to 2.00, particularly preferably 1.30 to 1.8
It is in the range of 0. It is preferable to use a crystalline aromatic polyester having a high degree of polymerization, that is, a high relative viscosity (ηr) because the degree of polymerization of the resulting elastic polyester will be high and the mechanical properties will be excellent.

Examples of the lactone compound used in the present invention include ε-caprolactone, enantlactone, and cabrylolactone, but ε-caprolactone is particularly preferred in view of its reactivity with the crystalline aromatic polyester and the elastic properties of the resulting elastic polyester. used.

In the present invention, the composition of the crystalline aromatic polyester and the lactone compound is preferably such that the weight ratio of the crystalline aromatic polyester/lactone compound is 99/l to 20/80, particularly from the mechanical properties of the resulting elastic polyester. Preferably it is 98/2 to 30/70.

When producing an elastic polyester by the addition reaction of the crystalline aromatic polyester of the present invention and a lactone compound, a catalyst may be added or the reaction may be carried out without a catalyst. All known catalysts for ring-opening polymerization of lactone compounds can be used as catalysts, including lithium, potassium, sodium, magnesium, calcium, barium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, Metals such as cadmium, manganese, zirconium,
These organometallic compounds, organic acid salts, alcoholades, alkoxides, and the like can be mentioned. Particularly preferred are tin compounds such as diacyl stannous, tetraacyl stannous, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanium, tetrabutylzirconium, germanium dioxide, and tin oxide. Antimony, cobalt acetate, etc. can be used, and two or more of these catalysts may be used in combination.

The catalyst may be added in advance during the production of the crystalline aromatic polyester, or added when the crystalline aromatic polyester and the lactone compound are fed to a single screw extruder.

The amount of these catalysts added is O to 0.3% by weight, particularly preferably 0.001 to 0.2% by weight, based on the total amount of the crystalline aromatic polyester and the lactone compound. If it is added in an amount of 0.3% by weight or more, the transesterification reaction between the crystalline aromatic polyester and polylactone will proceed, which will impair the mechanical properties of the resulting elastic polyester, which is not preferable.

After producing an elastic polyester by the addition reaction of the crystalline polyester of the present invention and a lactone compound, a phosphorus compound can be added. The phosphorus compound substantially deactivates or suppresses the activity of the catalyst present in the reaction system, and is used at the stage when the blocking reaction between the crystalline aromatic polyester and the lactone compound through the addition reaction and transesterification reaction has progressed appropriately. It is effective to add it, and has the effect of maximally suppressing the deterioration of the physical properties of the elastic polyester due to the subsequent randomization reaction.

Typical phosphorus compounds include inorganic acids such as phosphoric acid, phosphorous acid, and hypophosphorous acid, methylphosphinic acid, ethylphosphinic acid, isobutylphosphinic acid, benzylphosphinic acid, phenylphosphinic acid, and cyclophosphinic acid. Phosphinic acids such as hexylphosphonic acid and 4-methylphenylphosphonic acid, methylphosphonic acid, ethylphosphonic acid, isopropylphosphonic acid, isobutylphosphonic acid, benzylphosphonic acid, phenylphosphonic acid, cycloto xylphosphonic acid, 4
- Phosphonic acids such as methylphenylphosphonic acid and alkyl, cycloalkyl, aryl, aralkyl esters and partial esters thereof having 1 to 20 carbon atoms such as methyl, ethyl, propyl, cyclohexyl, phenyl and benzyl, as well as sodium and potassium thereof; , metal salts such as calcium and magnesium, or ammonium salts, phosphine oxides such as triethylphosphine oxide and triphenylphosphine oxide, and phosphines such as tributylphosphine, triphenylphosphine, tribenzylphosphine and tricyclohexylphosphine. I can do it.

Among these phosphorus compounds, compounds having a high boiling point or decomposition point are preferably used since they are added in the molten state of the elastic polyester. The amount of the phosphorus compound added is 1 catalyst atom
Each phosphorus atom is 0. 5 or more, particularly preferably 1.
It is effective to use 0 or more.

The continuous stirring mixer used in the present invention has a raw material supply port and a discharge port for discharging molten polymer, such as the one sold by BUSS under the name Ko-Kneader, and has a barrel in a barrel. This refers to a mixer that is equipped with a screw that is coaxial with the screw and has a large number of interrupted threads, and that operates so that the interrupted portions mesh with the teeth that protrude from the inner surface of the barrel. Furthermore, the method of installing the continuous stirring mixer is not particularly limited. Even if it is installed, it does not impair the purpose of the present invention.

The method of supplying the crystalline aromatic polyester and lactone compound to the supply port of the continuous stirring mixer is not particularly limited, but (
1) Method of simultaneously supplying solid crystalline aromatic polyester and lactone compound from the supply port, (2) Method of supplying solid state crystalline polyester from the supply port and lactone compound from the vent, (3) Method of supplying the solid state crystalline polyester from the supply port, (3) Melted state A method of simultaneously supplying a crystalline aromatic polyester and a lactone compound from a supply port, <4) A method of supplying a molten crystalline aromatic polyester from a supply port and a lactone compound from a vent, It is possible to adopt a method in which the polyester and the lactone compound are melt-mixed in advance and then supplied.

The conditions for addition polymerizing the crystalline aromatic polyester of the present invention and the lactone compound using a continuous stirring mixer are as follows:
at a temperature of 0 to 280°C, preferably 215 to 250°C,
The residence time in the extruder is 1 to 30 minutes, preferably 3 to 20 minutes.

Furthermore, as a method for removing the lactone compound monomer present in the polymer obtained by addition polymerization, (1) a vent hole is provided at the tip of the continuous stirring mixer used in addition polymerization, and the pressure is preferably 50 Torr or less. is a method for removing lactone compound monomers at a vacuum degree of 10 Torr or less, (2
) Supplying the polymer obtained by addition polymerization in a solid or molten state to a single-screw or twin-screw extruder equipped with a vent,
Temperature above the melting point of the polymer, degree of vacuum in the ventro, 50 T
A method for removing a lactone compound monomer at a temperature of at most 10 Torr, preferably at most 10 Torr, (3) supplying the polymer obtained by addition polymerization to a reactor equipped with a stirrer, and at a temperature of at least the melting point of the polymer and a degree of vacuum of at most 50 Torr. Examples include a method in which the lactone compound monomer is removed by residence for 1 to 30 minutes.

In addition, the elastic polyester of the present invention may contain known antioxidants such as hindered phenol-based, phosphite-based, thioether-based, and amine-based antioxidants, benzophenone-based, and hindered amine-based antioxidants, to the extent that the purpose of the present invention is not impaired. Weathering agents, fluorine-containing polymers, silicone oils, stearic acid metal salts, montanic acid metal salts, montanic acid ester waxes, mold release agents such as polyethylene wax, epoxy compounds, carbodiimide compounds, bisoxazoline compounds, acyllactam compounds, isocyanates Thickeners such as chemical compounds, colorants such as dyes and pigments, ultraviolet screening agents such as titanium oxide and carbon black, reinforcing agents such as glass fiber, carbon fiber, and caulifiber titanate, silica, clay, and calcium carbonate. , calcium sulfate,
Fillers such as glass peas, nucleating agents such as talc, flame retardants, plasticizers, adhesion aids, adhesives, etc. can be optionally contained. Furthermore, for the purpose of improving the mechanical strength of the elastic polyester of the present invention, other thermoplastic polymers or thermoplastic elastomers may be contained. These additives and polymers may be blended before the addition polymerization reaction between the crystalline aromatic polyester and the lactone compound, or may be blended into the elastic polyester after the addition polymerization reaction.

In the present invention, by using a continuous stirring mixer with high stirring efficiency as an addition polymerization reactor for crystalline aromatic polyester and lactone compound, high viscosity crystalline aromatic polyester, low viscosity lactone compound and Since the catalyst can be homogeneously mixed in a short time, high quality elastic polyester can be obtained continuously and economically.

<Example> The present invention will be explained in detail below using examples.

Note that all percentages and parts in the examples are based on weight.

Moreover, relative viscosity (ηr) is a value measured at 25° C. of a 0.5% polymer solution using 0-chlorophenol as a solvent. The surface hardness, melting point, and mechanical properties of the molded articles shown in Examples and Comparative Examples were measured as follows.

Molding: ASTMI dumbbell test specimens and Izotsu impact test specimens were injection molded using an injection molding machine with a 6 oz. .

Surface hardness: The surface hardness was measured according to the ASTM D-2240 method using the ASTMI dumbbell test piece obtained by the above injection molding.

Melting point: Measured by DSC (differential scanning calorimeter) at a heating rate of 10° C./min.

Mechanical properties: Tensile strength was measured according to the ASTM D-638 method using the ASTMI dumbbell test piece obtained by the above injection molding. In addition, impact strength was measured using an Izot impact test piece according to ASTM D-256 method.

Reference example: 100 parts of terephthalic acid, 110 parts of 1,4-butanediol
0.1 part of tetrabutyl titanate) was charged into an esterification vessel equipped with a rectification column and a helical ribbon stirring blade.
The reaction water was allowed to flow out while stirring, and the mixture was heated under nitrogen atmosphere at normal pressure for 2 hours.
After carrying out a closed esterification reaction at 20°C for 2 hours, the reactant was transferred to a polymerization tank, and heated at 250°C for 0.2 hours. Under a vacuum of 5 Torr,
After carrying out the intercalary polymerization reaction for 2 hours, the strands were discharged into water and cut to obtain polybutylene ethylene terephthalate) (A-
1) was obtained. The obtained polybutylene terephthalate (A
-1) has a relative viscosity (ηr) of 1.42 and a melting point of 225°C.
This polybutylene terephthalate (A
-1) was subjected to solid-phase polymerization at a salinity of 190°C and a vacuum of 0°5 Torr, and by changing the solid-state polymerization time,
Polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1°55 and polybutylene terephthalate (A-3) having a relative viscosity (ηr) of 1.70 were obtained. The melting points of both polybutylene terephthalate (A-2) and polybutylene terephthalate (A-3) were 225°C.

Example 1, Comparative Example 1.2 Using a photographic feeder, the relative viscosity (ηr) was 1.55
4k polybutylene terephthalate (A-2) pellets
g/hr, and also 1 kg/hr of ε-caprolactone using a metering pump, using Kneader PR-468/G5 commercially available from BUSS.
It was supplied to the supply port of Model 70B. PR-468/G570
The B-type co-kneader has a structure in which a G570B-type pelletizer is connected to a PR-46B-type kneader. PR-46
The mold kneader has a barrel diameter of 46.6 mm and a screw length (L
) and the diameter (D), that is, the effective screw length L/D = 1
5. It has the barrel 15 screw 2 structure shown in FIG. The G570B pelletizer has a barrel diameter of 70 mm and a screw effective length L/D = 6.
It is attached in a T-shape to the 46B type kneader.

The barrel part of this PR-46 type kneader is divided into three parts.
[The heat medium is circulated through the jacket of No. 1 to control the heating, and from the one closest to the supply port, the temperature is 210℃, 230℃, 230℃.
℃, and set the barrel part of G570B to 230℃,
The addition reaction was carried out at a screw rotation speed of 1100 rpm. At this time, carbon black powder was added from the supply port, and the average residence time was measured to be 12 minutes.Next, the polymer was discharged from the die in the form of a strand, cooled with water, and then cut to form an elastic polyester (B- 1) was obtained.

Further, polymerization was carried out continuously for 5 hours, injection molding was carried out in batches every hour, and the surface hardness was measured.

For comparison, a vibratory feeder was used to calculate the relative viscosity (η
r) is 1.55 polybutylene terephthalate (A-2)
The pellets were supplied at 1600 g/hr to the supply port 3 of the surface renewal type continuous polymerization tank shown in FIG. 2, and 400 g/hr of ε-caprolactone was supplied to the supply port 3 of the reaction tank using a metering pump. An elastic polyester (B-2) was obtained by staying at 230°C for an average of 12 minutes, and an elastic polyester (B-3) was obtained by staying at 230°C for an average of 120 minutes.

Table 1 shows the physical properties of the obtained elastic polyester and the variation in surface hardness during 5 hours of continuous operation.

From Table 1 below, it is clear that according to the present invention, elastic polyester with stable quality can be produced in a short time and has excellent mechanical properties.

Example 2.3 In Example 1, instead of polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1.55, the relative viscosity (ηr)
An addition polymerization reaction was carried out in the same manner as in Example 1 using polybutylene terephthalate (A-1) with a relative viscosity (ηr) of 1.42 and polybutylene terephthalate (A-3) with a relative viscosity (ηr) of 1.70. -4) and elastic polyester (B-5) were obtained. The physical properties are shown in Table 2.

2/11 Elastic polyester-4B-5 Relative viscosity 1.46 1.78 Surface hardness Saw? D63 63 melting point ℃
217 217 Tensile precipitation stress MPa
21 212? % 480
560 Example 4 In place of polybutylene terephthalate (A-2) with a relative viscosity (ηr) of 1.55 in Example 1, polybutylene terephthalate (A-2) with a relative viscosity (ηr) of 1.10 obtained by polymerization in the same manner as in the reference example was used. An addition polymerization reaction was carried out in the same manner as in Example 1 using polybutylene terephthalate.

The resulting elastic polyester (
The hourly melting point of B-6) in the 5-hour closed continuous addition polymerization reaction was 219.220.219.220.221'C, which was relatively stable.

Example 5 In Example 1, the supply amount of ε-caprolactone was changed to 500 g/h.
r, 2 kg/hr, and an addition polymerization reaction was carried out in the same manner as in Example 1 to obtain elastic polyester (B-7) and elastic polyester (B-8).

Table 3 shows the physical properties of each elastic polyester.

Margin below 3.1'7! Ale's elastic polyester-7B-8 Surface hardness Shea? D 76 53 Melting point ℃ 221 204 Tensile yield stress MPa 34 16% 310
640 It is clear from Table 3 that the elastic polyester of the present invention exhibits excellent physical properties.

Example 6 Elastic polyester (B-1) obtained in Example 1 100
part, triphenylphosphine 0. One part was tri-blended and kneaded using a vented single-screw extruder with an inner diameter of 30 mmφ and a full-flight screw equipped with a full-flight screw at a vent hole vacuum of 10 Torr, an extrusion temperature of 230°C, and a screw rotation speed of 6 Orpm. After that, the strands are discharged into water and sautéed to remove monomer (epsilon-caprolactone) and deactivate the catalyst, resulting in elastic polyester (B-9).
) was obtained.

The obtained elastic polyester (B-9) pellets had no monomer odor (ε-caprolactone odor), and the melting point was measured after melting and residence at 230°C for 30 minutes using a DSC (differential scanning calorimeter). The temperature was 217°C. Elastic polyester (B-1) was similarly melted and retained at 230°C for 30 minutes, and its melting point was measured and found to be 109°C. From this, it is clear that the addition of the phosphorus compound deactivated the catalyst and suppressed the randomization reaction due to the transesterification reaction.

Example 7 100 parts of polybutylene terephthalate (A-2) pellets with a relative viscosity (ηr) of 1.55, 0.0 parts of monobutyltin oxide. Part 1, Irganox 1330 (Ci ba
-Ge i gy? I1. 4 kg of a tri-blend mixture of 0.2 parts of H hindered phenolic heat stabilizer)
An elastic polyester (B-10) was obtained by carrying out an addition polymerization reaction in the same manner as in Example 1, except that the 0-elastic polyester (B-10) had a surface hardness of 63D and a melting point of 21.
It exhibited excellent physical properties at 7°C, tensile yield stress of 21 MPa, and impact of NB.

Example 8 In Example 1, a vent hole was provided in the middle of the 570B pelletizer, the monomer was removed at a vacuum level of 5 Torr, and an addition polymerization reaction was carried out in the same manner as in Example 1. The obtained elastic polyester (B-11) had a surface hardness of 63D, a melting point of 217°C, and no monomer odor at all.

<Effects of the Invention> By producing elastic polyester using the method of the present invention, the addition polymerization reaction time and monomer removal time are shortened.
Elastic polyester can be easily obtained with high efficiency using simplified equipment and operations.

In addition, the elastic polyester obtained by the present invention has heat resistance,
Because it has excellent durability such as weather resistance, rubber elasticity, and mechanical properties, it is used in a wide range of applications such as automobile parts, electrical/electronic parts, and mechanical parts.

[Brief explanation of drawings]

FIG. 1 shows a part of the screw and barrel of a continuous stirring mixer showing one embodiment of the present invention, and FIG. 2 shows a reactor used for comparison. 1 Barrel 2 Screw 3 Supply port 4 Discharge port

Claims (2)

[Claims] (1) Continuous stirring mixing of crystalline aromatic polyester and lactone compound in a barrel with a screw that is coaxial with the barrel and has a large number of interrupted ridges, and the interrupted parts are engaged with teeth protruding from the inner surface of the barrel. A method for producing elastic polyester, which comprises supplying the polyester to a machine and carrying out continuous addition polymerization. (2) The method for producing an elastic polyester according to claim (1), characterized in that unreacted lactone compounds are continuously removed from the elastic polyester.