JPH0733435B2 - Method for producing elastic polyester - Google Patents

Description

The present invention relates to a novel method for producing an elastic polyester having an aromatic polyester as a hard segment and an aliphatic polyester polylactone as a soft segment. More specifically, it relates to a method for economically producing elastic polyester of stable quality using an extruder.

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

The polyester polyester block copolymer type elastic polyester is produced by melt-mixing and reacting a crystalline aromatic polyester and a lactone compound, and is disclosed in JP-B-48-4116 and JP-B-52-
49037, JP 61-281124, JP 61-283
619, JP 61-287922, JP 62-20525
It is known from JP-A-62-27425, JP-A-62-53336 and the like.

<Problems to be Solved by the Invention> However, in the method of the above-mentioned known example, the reaction time is long, the aromatic polyester constituting the hard segment and the polylactone constituting the soft segment are partially randomized by transesterification reaction, and melting point and mechanical However, there is a problem that only an elastic polyester having a large variation in dynamic strength can be produced.

<Means for Solving the Problems> Therefore, as a result of intensive studies to solve the problems and economically obtain elastic polyester having stable quality, the present inventors have found that
The present invention has been reached.

That is, according to the present invention, a heating jacket is provided on the outer circumference of the reactor body, and the cross-section thereof has the shape of a circle having two concentric and eccentric diameters. And a pair of parallel stirring shafts and a plurality of plate-shaped paddles mounted on the shafts, the paddles having a convex section in a direction perpendicular to the longitudinal direction of the stirring shaft. Shape, ellipse or pseudo-polygon inscribed in a virtual circle at each apex angle, the paddle fixed to one stirring shaft faces the paddle fixed to the other stirring shaft, and one paddle at its tip. A crystalline aromatic polyester and a lactone compound are supplied from a supply port to carry out addition polymerization by using a continuous stirring and mixing machine that rotates with maintaining a slight clearance with the inner surface of the barrel and the facing paddle, and then elastic polyester. Take out from the discharge port There is provided a method for manufacturing the acoustic polyester characterized by and.

The crystalline aromatic polyester used in the present invention is a polymer having at least one kind of aromatic group and an ester bond in the main repeating unit, and includes polyethylene terephthalate, polybutylene terephthalate, poly 1,4-cyclohexylene diene. Methylene terephthalate, polyethylene 2,6
-Naphthalate, polybutylene 2,6-naphthalate, etc., but a mixture of these polyesters or these polyesters with an isophthalic acid unit, an aliphatic dicarboxylic acid unit such as adipic acid, sebacic acid, dodecanedioic acid, p-oxy Copolymerized polyesters in which benzoic acid units and the like are copolymerized can also be used. Among them, polybutylene terephthalate is particularly preferably used because it has excellent crystallinity.

The crystalline aromatic polyester relative viscosity (ηr) used in the present invention is 0.5 when o-chlorophenol is used as a solvent.
% Polymer solution measured at 25 ° C. is in the range of 1.20 to 2.00, particularly preferably 1.30 to 1.80. It is preferable to use a crystalline aromatic polyester having a high degree of polymerization, that is, a high relative viscosity (ηr), because the obtained elastic polyester has a high degree of polymerization and excellent mechanical properties.

Examples of the lactone compound used in the present invention include ε-caprolactone, enanthlactone, and caprylolactone, but ε-caprolactone is particularly preferable from the viewpoint of reactivity with the crystalline aromatic polyester and the elastic properties of the elastic polyester obtained. used.

The composition ratio of the crystalline aromatic polyester and the lactone compound in the present invention is preferably 99/1 to 20/80 in terms of the weight ratio of the crystalline aromatic polyester / lactone compound from the mechanical properties of the obtained elastic polyester, and particularly, Preferably 98 / 2-30 /
70.

When an elastic polyester is produced 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 performed without a catalyst. As the catalyst, all known catalysts for ring-opening polymerization of lactone compounds can be used, and specifically, lithium, potassium, sodium, magnesium, calcium, barium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, Examples thereof include metals such as cadmium, manganese and zirconium, organic metal compounds thereof, organic acid salts, alcoholates, alkoxides and the like. Particularly preferably, tin compounds such as diacyl stannous tin, tetraacyl stannic tin, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, tin tetraacetate, triisobutylaluminum, tetrabutyltitanium, tetrabutylzirconium, germanium dioxide, and three. Antimony oxide,
Cobalt acetate, etc. can be used.
You may use together 1 or more types.

As a method of adding the catalyst, a method of adding it at the time of producing the crystalline aromatic polyester in advance or a method of adding it when supplying the crystalline aromatic polyester and the lactone compound to a single-screw extruder can be adopted.

The addition amount of these catalysts is 0 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. Addition of 0.3% by weight or more is not preferable because the transesterification reaction between the crystalline aromatic polyester and the polylactone proceeds and the mechanical properties of the obtained elastic polyester are impaired.

The phosphorus compound can be added after the elastic polyester is produced by the addition reaction of the crystalline polyester of the present invention and the lactone compound. The phosphorus compound substantially deactivates or suppresses the activity of the catalyst present in the reaction system, and when the blocking reaction by the addition reaction and the transesterification reaction of the crystalline aromatic polyester and the lactone compound appropriately proceeds. 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, hypophosphorous acid, methyl phosphinic acid, ethyl phosphinic acid, isobutyl phosphinic acid, benzyl phosphinic acid, phenyl phosphinic acid, cyclohexyl. Phosphinic acids such as phosphinic acid and 4-methylphenyl phosphinic acid, methyl phosphonic acid, ethyl phosphonic acid, isopropyl phosphonate, isobutyl phosphonate, benzyl phosphonate, phenyl phosphonate, cyclohexyl phosphonate Four
-Phosphonic acids such as methylphenylphosphonic acid and their alkyls having 1 to 20 carbon atoms such as methyl, ethyl, propyl, cyclohexyl, phenyl and benzyl;
Cycloalkyl, aryl, aralkyl esters and partial esters as well as their sodium, potassium,
Metal salts such as calcium and magnesium, or ammonium salts, phosphine oxides such as triethylphosphine oxide and triphenylphosphine oxide, tributylphosphine, triphenylphosphine,
Examples thereof include phosphines such as tribenzylphosphine and tricyclohexylphosphine.

Among these phosphorus compounds, since they are added in the molten state of the elastic polyester, compounds having a high boiling point or decomposition point are preferably used. The addition amount of the above phosphorus compound is 1
It is effective to use 0.5 or more, particularly preferably 1.0 or more phosphorus atoms per one.

The reactor used in the present invention is a continuous stirring mixer having a plurality of paddles mounted on two parallel shafts, and in order to obtain a good self-cleaning effect and stirring effect, the tip of the paddle and the inner surface of the cylinder are 2% or less, especially 1% or less, of the diameter of the circumscribed circle of the paddle is preferable, and the clearance between the opposing paddles is 5 times or less,
It is particularly preferably twice or less.

And, considering the fluctuation of clearance due to the work precision and the deflection of the shaft and the operational stability, L / D (where L is the length of the reactor cylinder and D is the inner diameter of the reactor) is usually 20 or less, preferably 6-15.

The shape of the paddle of the reactor used in the present invention is a convex lens shape, an elliptical shape, or a pseudopolygon inscribed in a virtual circle at each apex angle, and further, each side surface of the tip portion of the paddle is symmetrically twisted. It is also possible to use a helical type in which the side surfaces are rotationally symmetrical with respect to the stirring axis. That is, the twisted helical type whose side surface pushes the contents to the discharge port by rotating the stirring shaft has a larger feeding effect than the normal flat type, and the helical type twisted in the opposite direction has a large reverse feeding effect. Indicates.
The tip of the paddle may have a circumferential surface, a flat surface, an acute angle, or a sharp scraper may be provided on these.

The thickness of the paddle used in the present invention is 0.05 to 0.2 of the major axis.
About twice is preferable.

Further, as a method of arranging the paddles in the present invention, when a convex lens-shaped or elliptical paddle is used, the paddles adjacent in the longitudinal direction of the stirring shaft are 90 ° with respect to the rotation direction of the stirring shaft.
The method of arranging the combination shifted by 45 ° and the combination shifted by 45 ° is particularly preferable because the feeding effect is small and a large amount of polymer is retained.

The screw used at the lower part of the supply port of the reactor is of a type that meshes with each other, and between the upper part of the discharge port and the tip part of the reactor, it is possible to use a reverse feed screw in order to efficiently push out the polymer. it can.

FIG. 1 shows a reactor as an embodiment of the present invention.
The reactor is a biaxial self-cleaning mixer having a stirring shaft 1, a plurality of plate-shaped paddles 2 and a temperature adjusting jacket 3. The crystalline aromatic polyester and the lactone compound are supplied from the supply port 4, and the polymerized elastic polyester is discharged from the discharge port 5.

Various sectional shapes of the paddle 2 are shown in FIG. 2A is a convex lens type, FIG. 2B is a helical type with a twisted tip, and FIG. 3C is a pseudo-triangular type.

The lower part of the supply port 4 and the upper part of the discharge port 5 of the reactor are constituted by ordinary screws 6.

Further, the installation method of the continuous stirring and mixing machine is not particularly limited, and even if the screw shaft is installed horizontally, it should have an angle with respect to the horizontal axis to prevent a short pass of the liquid lactone compound. Even if installed, the purpose of the present invention is not impaired.

The method for supplying the crystalline aromatic polyester and the lactone compound to the supply port of the continuous stirring mixer is not particularly limited,
(1) A method of simultaneously supplying a solid-state crystalline aromatic polyester and a lactone compound from a supply port, (2) A method of supplying a solid-state crystalline polyester from a supply port and a lactone compound from a vent port, (3) A method of simultaneously supplying a crystalline aromatic aromatic polyester and a lactone compound from a supply port, (4) a method of supplying a crystalline aromatic aromatic polyester from a supply port and a lactone compound from a vent port, (5) crystal A method in which the aromatic aromatic polyester and the lactone compound are melt-mixed in advance and then supplied can be employed.

The conditions for the addition polymerization of the crystalline aromatic polyester of the present invention and the lactone compound with a continuous stirring mixer are:
At a temperature of 280 ° C, preferably 215 to 250 ° C, the residence time in the mixer 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 the addition polymerization, (1) a vent port is provided at the tip of the continuous stirring mixer used in the addition polymerization, and 50 Torr or less, preferably Is a method of removing the lactone compound monomer at a vacuum degree of 10 Torr or less. (2) The polymer obtained by the addition polymerization is fed in a solid or molten state to a single-screw or twin-screw extruder having a vent port to melt the polymer. Above temperature, vacuum degree of vent port, 50 Torr or less, preferably
Method of removing lactone compound monomer at 10 Torr or less,
(3) A method in which a polymer obtained by addition polymerization is supplied to a reactor having a stirrer, and the lactone compound monomer is removed by allowing the polymer to stay for 1 to 30 minutes at a temperature above the melting point of the polymer and a vacuum degree of below 50 Torr. Can be mentioned.

In addition, the elastic polyester of the present invention has a known weather resistance such as hindered phenol-based, phosphite-based, thioether-based, amine-based antioxidants, benzophenone-based, hindered amine-based, etc. Agents, fluorine-containing polymers, silicone oils, metal stearates, metal montanates, montanate waxes, mold release agents such as polyethylene waxes, epoxy compounds, carbodiimide compounds, bisoxazoline compounds, acyllactam compounds, isocyanate compounds Such as thickeners, coloring agents such as dyes and pigments, UV shielding agents such as titanium oxide and carbon black, reinforcing agents such as glass fibers and carb fibers, potassium titanate fibers,
Fillers such as silica, clay, calcium carbonate, calcium sulfate, glass beads, nucleating agents such as talc, flame retardants,
A plasticizer, an adhesion aid, a pressure-sensitive adhesive, etc. can be optionally contained. Further, in order to improve the mechanical strength of the elastic polyester of the present invention, another thermoplastic polymer or thermoplastic elastomer may be contained. These additives and polymers may be blended before the addition polymerization reaction of the crystalline aromatic polyester and the lactone compound, or may be blended with the elastic polyester after the addition polymerization reaction.

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

<Examples> The effects of the present invention will be described below with reference to Examples. All percentages and parts in the examples are by weight. Further, the relative viscosity (ηr) is a value measured at 25 ° C. in a 0.5% polymer solution using o-chlorophenol as a solvent. The surface hardness, melting point and mechanical properties of the molded products shown in Examples and Comparative Examples were measured as follows.

Molding: Using an injection molding machine with a 5 ounce injection capacity,
Cylinder temperature 240 ℃, mold temperature 80 ℃ and molding cycle 4
The ASTM No. 1 dumbbell test piece and the Izod impact test piece were injection-molded at 0 second.

Surface hardness: Using the ASTM No. 1 dumbbell test piece obtained by the above injection molding, the surface hardness was measured according to the ASTM D-2240 method.

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

Mechanical properties: Using the ASTM No. 1 dumbbell test piece obtained by the above-mentioned injection molding, the tensile properties were measured according to the ASTM D-638 method. Also, using the Izod impact test piece, ASTM D
The impact strength was measured according to the -256 method.

Reference Example 100 parts of terephthalic acid, 110 parts of 1,4-butanediol and 0.1 part of tetrabutyl titanate were charged into an esterification can equipped with a rectification column and a helical ribbon type stirring blade, and the reaction water was discharged while stirring to remove nitrogen. After carrying out an esterification reaction at 220 ° C. for 2 hours under atmospheric pressure, the reaction product is transferred to a polymerization vessel,
After carrying out a polymerization reaction for 2 hours under a vacuum of 250 ° C and 0.5 Torr,
A polybutylene terephthalate (A-1) was obtained by discharging in strand form in water and cutting. The relative viscosity (ηr) of the obtained polybutylene terephthalate (A-1) is
The melting point was 1.47 and the melting point was 225 ° C. Next, this polybutylene terephthalate (A-1) is subjected to solid phase polymerization at a temperature of 190 ° C. and a vacuum degree of 0.5 Torr, and by changing the solid phase polymerization time, polybutylene having a relative viscosity (ηr) of 1.60 is obtained. Polybutylene terephthalate (A-3) having a relative viscosity (ηr) of 1.77 was obtained. The melting points of polybutylene terephthalate (A-2) and polybutylene terephthalate (A-3) were both 225 ° C.

Example 1 and Comparative Examples 1 and 2 Example 1 A self-cleaning twin-screw mixer as shown in FIG. 1 was used as a polymerization reactor, and a relative viscosity (ηr) was 1.60 polybutylene terephthalate (using a vibration feeder). A-
2) Pellet at 14kg / hr and ε-caprolactone 6kg
/ hr was supplied to the supply port 4 with a metering pump.

The inner diameter of the reactor was 100 mm, and the L / D was 15. Paddle is second
A paddle having a convex lens type cross section as shown in FIG. 3A is used, and the lower part of the supply port 4 and the upper part of the discharge port 5 are ordinary screws.

The stirring shaft was set to 100 rpm by rotating in the same direction. The jacket of the reactor was set to 230 ° C. with a heating medium. The average residence time at this time was 10 minutes, and the elastic polyester (B-1) was obtained by discharging in strands from the discharging part 5 into water and cutting.

Further, polymerization was continuously carried out for 5 hours, injection molding was carried out collectively for every 1 hour, and the surface hardness was measured.

For comparison, the relative viscosity (η
r) was 1.60 polybutylene terephthalate (A-2) pellets 14 kg / hr, which was supplied to the supply port 7 of the surface renewal type continuous polymerization tank shown in FIG. 3, and ε-caprolactone 6 kg / hr.
Was supplied to the supply port 7 of the reaction tank by a metering pump. 230 ° C
Elastic polyester (B-2) after staying for an average of 10 minutes at 120 ° C. and elastic polyester (B-
3) was obtained. Table 1 shows the physical properties of the obtained elastic polyester and the surface hardness variation after continuous operation for 5 hours.

It is apparent from Table 1 that the elastic polyester of stable quality according to the present invention can be produced in a short time and has excellent mechanical properties.

Examples 2 and 3 Instead of the polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1.60 in Example 1, a polybutylene terephthalate (A-1) having a relative viscosity (ηr) of 1.47 and a relative viscosity (ηr) are used. 1.77 Polybutylene terephthalate (A-3)
Was subjected to an addition polymerization reaction in the same manner as in Example 1 to obtain elastic polyester (B-4) and elastic polyester (B-5).
Got The physical properties are shown in Table 2.

Example 4 Instead of the polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1.60 in Example 1, polybutylene terephthalate having a relative viscosity (ηr) of 1.15 obtained by carrying out polymerization in the same manner as in Reference Example was used. Using this, an addition polymerization reaction was carried out in the same manner as in Example 1. The discharge amount of the polymer was not stable, but the surface hardness variation per hour in the continuous addition polymerization reaction of the obtained elastic polyester (B-6) for 5 hours was 55, 54, 56, 54,
It was stable at 55.

Example 5 An elastic polyester (B-7) was obtained by performing the addition polymerization reaction in the same manner as in Example 1 while supplying 12 kg / hr as the amount of ε-caprolactone supplied in Example 1. Elastic polyester (B-
The physical properties of 7) are surface hardness of 40D, melting point of 172 ℃, and tensile yield stress.
It showed excellent values of 12 MPa and tensile elongation at break of 1000%.

Example 6 Elastic polyester (B-1) 100 obtained in Example 1
Part, 0.1 parts of triphenylphosphine are dry blended, and using a vented single-screw extruder equipped with a full flight screw with an inner diameter of 30 mmφ and L / D = 40, the degree of vacuum at the vent port is 10 Torr, the extrusion temperature is 230 ° C., After kneading at a screw rotation speed of 60 rpm, the mixture was discharged into water in a strand form and subjected to demonomerization (de-ε-caprolactone) and catalyst deactivation to obtain an elastic polyester (B-8).

The obtained elastic polyester (B-8) pellets had no monomer odor (ε-caprolactone odor), were melt-retained by DSC (differential scanning calorimeter) at 230 ° C. for 30 minutes, and then were measured for melting point. It was 207 ° C. Elastic polyester (B-
When 1) was melted and retained at 230 ° C. for 30 minutes in the same manner and the melting point was measured, it was 196 ° C. From this, it is clear that the addition of the phosphorus compound deactivated the catalyst and suppressed the randomization reaction by the transesterification reaction.

Example 7 Relative viscosity (ηr) 1.60 Polybutylene terephthalate (A
-2) 100 parts of pellets, 0.1 part of monobutyltin oxide,
The addition polymerization reaction was carried out in the same manner as in Example 1 except that 0.2 kg of Irganox 1330 (a hindered phenolic heat stabilizer manufactured by Ciba-Geigy) was dry-blended at a rate of 14 kg / hr. -9) was obtained. Elastic polyester (B-9) has a surface hardness of 55D, a melting point of 206 ° C,
It showed excellent physical properties such as tensile yield stress of 18 MPa and Izod impact NB.

Example 8 In Example 1, a vent was provided at the tip of the continuous stirring mixer, demonomerization was performed at a vacuum degree of 5 Torr, and an addition polymerization reaction was carried out in the same manner as in Example 1 to produce an elastic polyester (B-10).
Got Elastic polyester (B-10) has no odor,
It showed excellent physical properties such as surface hardness 54D, melting point 206 ℃, tensile yield stress 18MPa and Izod impact NB.

<Effects of the Invention> By producing an elastic polyester by the method of the present invention, the addition polymerization reaction time and the demonomerization time are shortened, so that an elastic polyester can be easily obtained with high efficiency by a simplified apparatus and operation. You can

Further, the elastic polyester obtained in the present invention has heat resistance,
Since it has excellent durability represented by weather resistance, rubber elasticity, and mechanical properties, it can be used in a wide range of applications such as automobile parts, electric / electronic parts, and mechanical parts.

[Brief description of drawings]

FIG. 1 shows a continuous stirrer / mixer showing an embodiment of the present invention, and FIGS. 2 (A) to 2 (C) each show a typical paddle shape. FIG. 3 shows the reactor used for comparison. 1: stirring shaft, 2: paddle, 3: temperature adjustment jacket, 4: supply port, 5: discharge port, 6: screw, 7: supply port, 8: discharge port

Claims (2)

[Claims] 1. A reactor having a heating jacket on the outer circumference of the reactor body, the cross section of which has a shape of two overlapping and eccentric circles with the same diameter. A raw material supply port is provided at each end of the reactor. A discharge port for the polymerization product is provided, and a pair of parallel stirring shafts and a plurality of plate-shaped paddles mounted on the shafts are provided therein, and the paddles have a convex lens-shaped cross section in the direction perpendicular to the longitudinal direction of the stirring shaft. , An oval or a quasi-polygon inscribed in a virtual circle at each apex angle, the paddle fixed to one stirring shaft faces the paddle fixed to the other stirring shaft, and one paddle is Using a continuous stirring mixer that rotates while maintaining a slight clearance with the inner surface and the facing paddle, a crystalline aromatic polyester and a lactone compound are supplied from a supply port to carry out addition polymerization to give an elastic polyester. Take out from the discharge port Method for manufacturing the acoustic polyester characterized. 2. The method for producing an elastic polyester according to claim 1, wherein the unreacted lactone compound is continuously removed from the elastic polyester.