JPH0733434B2 - 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 a special reactor.

<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.

This 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-52-49.
037, JP 61-281124, JP 61-28361
No. 9, JP-A-61-287922, JP-A-62-20525, JP-A-62-27425 and JP-A-62-53336.

<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, and the melting point and surface are There is a problem that only elastic polyesters having large variations in hardness and mechanical strength can be produced.

<Means for Solving the Problems> Therefore, the inventors of the present invention have achieved the present invention as a result of intensive studies to solve the above problems and economically obtain an elastic polyester having stable quality.

That is, according to the present invention, a crystalline aromatic polyester and a lactone compound are provided in a barrel, and the screw is coaxial with the barrel and has a large number of interrupted ridges, and the interrupted portion and teeth protruding on the inner surface of the barrel operate so as to mesh with each other. The present invention provides a method for producing an elastic polyester, which is characterized in that it is fed to a continuous stirring mixer to continuously carry out addition polymerization.

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 and the like can be mentioned, but a mixture of these polyesters or these polyesters is further added with isophthalic acid units, adipic acid, sebacic acid, dodecanedioic acid or other aliphatic dicarboxylic acid units, p- A copolyester in which oxybenzoic 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 relative viscosity (ηr) of the crystalline aromatic polyester used in the present invention is 0.
The value measured with a 5% polymer solution 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 or the like can be used, and two or more kinds of these catalysts may be used in combination.

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 continuous stirring mixer used in the present invention has a raw material supply port as sold under the name of Ko-Kneader by BUSS and a discharge port for discharging a polymer in a molten state, and a barrel in the barrel. And a screw having a large number of interrupted ridges coaxial with each other, and operating so that the interrupted portion and the teeth protruding on the inner surface of the barrel mesh with each other. Further, the installation method of the continuous stirring mixer is not particularly limited, even if the screw shaft is installed horizontally,
The object of the present invention is not impaired even if the liquid lactone compound is installed at an angle with respect to the horizontal axis in order to prevent a short pass of the liquid lactone compound.

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 215-250 ° C, the residence time in the extruder is 1-30 minutes, preferably 3-20 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 ester waxes, mold release agents such as polyethylene waxes, epoxy compounds, carbodiimide compounds, bisoxazoline compounds, acyllactam compounds, isocyanate compounds Thickeners, colorants such as dyes and pigments, titanium oxide, ultraviolet shielding agents such as carbon black, glass fibers and carbon fibers, reinforcing agents such as potassium titanate, silica, clay, calcium carbonate, calcium sulfate, Glass beads etc. Fillers, nucleating agents such as talc, flame retardants, plasticizers, adhesion aids, can be allowed to optionally contain an adhesive or the like,. 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,
You may mix | blend with an elastic polyester after an 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 250 ℃, 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 injection molding, the tensile strength was 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 1.42 and the melting point was 225 ° C. Next, this polybutylene terephthalate (A-1) was subjected to solid phase polymerization at a temperature of 190 ° C. and a vacuum degree of 0.5 Torr, and the solid phase polymerization time was changed to obtain a relative viscosity (ηr) of 1.55. Polybutylene terephthalate (A-2) and polybutylene terephthalate (A-3) having a relative viscosity (ηr) of 1.70 were 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 Using a vibration feeder, relative viscosity (ηr) of 1.55 polybutylene terephthalate (A-2) pellets was 4 kg / hr.
In addition, using a metering pump, ε-caprolactone 1k
g / hr was measured by Ko-Knea, which is commercially available from BUSS.
der) PR-46B / GS70B type supply port. PR-46B / GS
The 70B type kneader has a structure in which the GS70B type pelletizer is connected to the PR-46B type kneader. PR-46 type kneader
Barrel diameter 46.6mm, ratio of screw length (L) and diameter (D),
That is, it has a screw effective length L / D = 15, the barrel 1 and the screw 2 structure shown in FIG. GS70B type pelletizer has a barrel diameter of 70 mm and an effective screw length L / D.
= 6, it is attached to the PR-46B type kneader in a T shape. In the barrel of this PR-46 type kneader, the heating medium is circulated in three jackets divided into three, and the heating is controlled. From the side close to the supply port to 210 ℃, 230 ℃, 230 ℃, GS70B The barrel of the is set to 230 ℃, the screw speed
The addition reaction was performed at 100 rpm. At this time, carbon black powder was added from the supply port and the average residence time was measured.
It was 12 minutes. Next, the polymer was discharged in a strand form from the die, cooled with water, and then cut to obtain an elastic polyester (B-1).

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 1.55 polybutylene terephthalate (A-2) pellets at 1600 g / hr, and was supplied to the supply port 3 of the surface renewal type continuous polymerization tank shown in FIG.
/ hr was supplied to the supply port 3 of the reaction tank by a metering pump. 230
Elastic polyester (B-2) by staying for an average of 12 minutes at
The 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 polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1.55 in Example 1, a relative viscosity (ηr) of 1.42 was used.
Polybutylene terephthalate (A-1) and a relative viscosity (ηr) of 1.70 polybutylene terephthalate (A-)
3) was used to carry out an addition polymerization reaction in the same manner as in Example 1,
Elastic polyester (B-4) and elastic polyester (B-
5) was obtained. The physical properties are shown in Table 2.

Example 4 Instead of the polybutylene terephthalate (A-2) having a relative viscosity (ηr) of 1.55 in Example 1, a polybutylene terephthalate having a relative viscosity (ηr) of 1.10. Then, the addition polymerization reaction was carried out in the same manner as in Example 1. The biting property into the continuous stirring mixer is rather poor,
Although the discharge amount of the polymer was not stable, the melting point of the obtained elastic polyester (B-6) in 1 hour continuous addition polymerization reaction was 219, 220, 219, 220, 221 ° C, which is relatively high. It was stable.

Example 5 In Example 1, the supply amount of ε-caprolactone was 500 g / hr and 2 kg.
/ hr, and the addition polymerization reaction is carried out in the same manner as in Example 1,
Elastic polyester (B-7) and elastic polyester (B-
8) was obtained. Table 3 shows the physical properties of each elastic polyester.
Shown in.

From Table 3, it is clear that the elastic polyester of the present invention exhibits excellent physical properties.

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 rotational 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-9).

The obtained elastic polyester (B-9) 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 217 ° C. Elastic polyester (B-
When 1) was melted and retained for 30 minutes at 230 ° C. and the melting point was measured, it was 109 ° 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 7 100 parts of polybutylene terephthalate (A-2) pellets having a relative viscosity (ηr) of 1.55, monobutyltin oxide 0.1
Part, and Irganox 1330 (hindered phenolic heat stabilizer manufactured by Ciba-Geigy Co.) 0.2 part were blended in the same manner as in Example 1 except that the composition was dry-blended at 4 kg / hr, and the elastic polyester was obtained. (B-10) was obtained. Elastic polyester (B-10) has a surface hardness of 63D and a melting point of 217.
℃, tensile yield stress 21MPa, Izud impact NB and excellent physical properties.

Example 8 In Example 1, a vent was provided at an intermediate position of the GS70B pelletizer, 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. The obtained elastic polyester (B-11) had a surface hardness of 63D and a melting point of 217 ° C. and had no monomer odor at all.

<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 part of a screw and barrel of a continuous stirring mixer showing an 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. A continuous barrel having a crystalline aromatic polyester and a lactone compound in a barrel, the screw being coaxial with the barrel and having a large number of interrupted ridges, and the interrupted portion and teeth protruding from the inner surface of the barrel are engaged with each other. A method for producing an elastic polyester, which comprises supplying to a stirring mixer and continuously carrying out addition polymerization. 2. The method for producing an elastic polyester according to claim 1, wherein the unreacted lactone compound is continuously removed from the elastic polyester.