JPH05465A - Elastic polyester tubular body - Google Patents

Abstract

PURPOSE:To manufacture economically an elastic polyester tubular body of superior mechanical properties and thermal stability by preparing elastic polyester of high viscosity in a short time. CONSTITUTION:An elastic polyester tubular body is manufactured by addition polymerizing continuously crystal aromatic polyester and a lactone compound and then tube molding continuously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic polyester tubular body having a crystalline aromatic polyester as a hard segment and a polylactone as a soft segment. More specifically, it relates to an elastic polyester tubular body which can be economically molded and has excellent mechanical properties and thermal stability.

[0002]

2. Description of the Related Art A crystalline aromatic polyester such as polybutylene terephthalate constitutes a hard segment,
Polylactone polyester type block copolymers in which polylactone constitutes the soft segment are thermoplastic elastomers with excellent tensile strength, impact strength, bending fatigue resistance, and heat deterioration resistance, which can be produced by injection molding or extrusion molding. Widely used in parts, electrical / electronic parts, mechanical parts, etc. The elastic polyester of the polyester-polyester block copolymer is produced by melt-mixing and reacting a crystalline aromatic polyester and a lactone compound in a reaction tank,
Japanese Patent Publication No. 48-4116, Japanese Patent Publication No. 52-49037
JP-B, JP-B-52-49037, JP-A-61-
281,124, JP 61-283619, JP 61-287922, and JP 62-2.
No. 0525, JP-A-62-27425, JP-A-62-53336 and the like.

[0003]

However, in the above-mentioned production method of the known example, the reaction time is long, so that it is economically inferior, and in order to produce a tube from the polymer obtained by this method, a polymer chip is used. -Because it is necessary to mold into a tubular body by charging into a tube molding machine and re-melting, the aromatic polyester constituting the hard segment and the polylactone constituting the soft segment are partially randomized by transesterification reaction, There was a problem that the tube was inferior in heat resistance and mechanical strength. Therefore,
An object of the present invention is to solve the above problems and to economically obtain an elastic polyester tubular body such as a tube or a hose with stable quality.

[0004]

That is, the present invention provides an elastic polyester tubular body which is obtained by continuously addition-polymerizing a crystalline aromatic polyester and a lactone compound and then continuously tube-molding. .

In the present invention, the crystalline aromatic polyester is a polymer having an ester bond with at least one aromatic group in the main repeating unit, and includes polyethylene terephthalate, polybutylene terephthalate and poly 1,4-cyclohexene. Cilendimethylene terephthalate,
Polyethylene 2,6-naphthalate, polybutylene 2,
Examples thereof include 6-naphthalate, and mixtures of these polyesters, and these polyesters further include an isophthalic acid unit, an aliphatic dicarboxylic acid unit such as adipic acid, sebacic acid, and dodecanedioic acid, and p-oxybenzoic acid unit. Mention may also be made of copolymerized copolyesters. Among them, polybutylene terephthalate is
It is particularly preferable because it has excellent crystallinity.

In the present invention, the lactone compound means ε
-Caprolactone, enanthlactone, caprylolactone and the like can be mentioned, and a mixture thereof can also be used. Of these, ε-caprolactone is preferable because of its reactivity with the crystalline aromatic polyester and the elastic properties of the obtained polyester-polyester block copolymer. The composition ratio of the crystalline aromatic polyester and the lactone compound in the polyester polyester block copolymer used in the present invention depends on the weight of the crystalline aromatic polyester / lactone compound from the mechanical properties of the obtained polyester polyester block copolymer. The ratio is 99/1 to 20 /
80 is preferable, and particularly preferably 98/2 to 30/7.
It is 0.

In the present invention, a catalyst is not necessary, but it is preferable to use an organotin compound and a phosphorus compound to accelerate the reaction.

As the organotin compound used in the present invention, for example, monoalkyltin compounds, monoaryltin compounds, dialkyltin compounds, diaryltin compounds, trialkyltin compounds, triaryltin compounds, tetraalkyltin compounds and the like are used. To be Among these, especially monobutyl monohydroxytin oxide, monobutyltin triacetate, monobutyltin monooctylate, monobutyltin monoacetate, monoalkyltin monoaryltin compounds such as monophenyltin triacetate and dibutyltin oxide, dibutyltin dichloride, dibutyltin dilaurate. Dialkyl or diaryltin compounds such as dibutyltin maleate, dibutyltin diacetate and diphenyltin oxide are effective and are preferably used. The amount of the tin compound added is preferably 0.001 to 0.5% by weight, based on the elastic polyester of the polyester-polyester block copolymer, as the amount of tin atoms, and further 0.0
02-0.3% by weight is particularly preferred. As the method for adding the organotin compound, a method that is added in advance when the crystalline aromatic polyester is produced, a method that is added when the crystalline aromatic polyester and the lactone compound are supplied to the reactor, and the like are adopted.

Examples of the phosphorus compound used in the present invention include pentavalent phosphorus compounds such as phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, phosphoric acid ester, phosphorous acid ester, phosphonic acid ester and phosphinic acid ester. And trivalent phosphorus compounds such as phosphinic acid, phosphinauic acid, phosphine, phosphonite, phosphinite, and phosphite, phosphorus compounds containing different elements, phosphorus compounds having a vinyl group, and polyphosphorus compounds.

Of these phosphorus compounds, pentavalent phosphorus compounds and phosphite phosphorus compounds are preferably used. It is effective that the phosphorus compound is added in an amount of 0.5 or more, particularly preferably 1.0 or more, per tin atom.

The method of adding the phosphorus compound is not particularly limited, and it may be added in advance when the crystalline aromatic polyester is produced, or may be added when the crystalline aromatic polyester and the lactone compound are fed to the reactor. A method of adding to the elastic polyester after the addition polymerization reaction is adopted.

The elastic polyester of the present invention contains known hindered phenol-based, thioether-based, amine-based antioxidants, etc. within a range not impairing the object of the present invention.
Benzophenone-based, hindered amine-based weathering agents,
Fluorine-containing polymers, silicone oils, metal salts of stearic acid, metal salts of montanic acid, waxes of montanic acid ester, mold releasing agents such as polyethylene wax, epoxy compounds, carbodiimide compounds, bisoxazoline compounds,
Acyl lactam compounds, thickeners such as isocyanate compounds, colorants such as dyes and pigments, UV blocking agents such as titanium oxide and carbon black, reinforcing agents such as glass fibers and carbon fibers, potassium titanate fibers, silica, clay , Calcium carbonate, calcium sulfate, a filler such as glass beads, a nucleating agent such as talc, a flame retardant, a plasticizer, an adhesive, an adhesion aid, an adhesive and the like can be optionally contained. Further, another thermoplastic polymer or thermoplastic elastomer may be contained for the purpose of improving the mechanical strength of the elastic polyester of the present invention. These additives and polymers may be blended before the addition polymerization reaction of the crystalline aromatic polyester and the lactone compound,
It may be added to the elastic polyester after the addition polymerization reaction.

The addition polymerization method of the present invention is a method in which addition polymerization is continuously carried out using one or more extruders, and as the extruder, a single screw extruder, a twin screw extruder, a mixer type extruder,
Examples include a kneader type extruder. The method of supplying the crystalline aromatic polyester and the lactone compound is not particularly limited, but (1) a method of simultaneously supplying the crystalline aromatic polyester and the lactone compound in the solid state from the supply port,
(2) A method of supplying a crystalline polyester in a solid state from a supply port and a lactone compound from a vent port, (3) A method of simultaneously supplying a crystalline aromatic polyester in a molten state and a lactone compound from a supply port, (4) A method of supplying the crystalline polyester in a molten state from a supply port and a lactone compound from a vent port, a method of (5) melting and mixing the crystalline polyester and the lactone compound in advance, and the like can be adopted. The conditions for addition polymerization in the extruder are 210 to 280 ° C., preferably 215 to 270.
At a temperature of ° C, the residence time in the extruder is 1 to 30 minutes, preferably 1.5 to 20 minutes. Further, 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 extruder used in the addition polymerization, and 50 Torr or less, preferably 10 Torr or less A method of removing the lactone compound monomer at a vacuum degree of (2), supplying the polymer obtained by the addition polymerization in a solid or molten state to an extruder having a vent port,
Temperature above the melting point of the polymer, vacuum degree at the vent port 50 Tor
A method of removing the lactone compound monomer at r or less, preferably 10 Torr or less can be mentioned.

The method for continuously tube-forming the tubular body of the present invention is not particularly limited, but a conventionally known method can be adopted. That is, it can be obtained by molding from the above extruder in a molten state into a cylindrical shape through a die, subsequently molding and cooling to a predetermined size and circular shape with a homing device, and cutting this into a predetermined length through a take-up machine. it can. If the melt viscosity of the polymer used at this time is low or the solidification time is long, in order to maintain the circular shape and size of the molten tube extruded from the die, the homing part should be cooled sufficiently by the internal pressure method, vacuum homing method, etc. The target tube molded body can be obtained by taking into consideration such as adjusting the length of the cooling zone, the cooling temperature, and reducing the frictional resistance of the sliding surface so as to obtain solidification and roundness shaping.

[0015]

In the present invention, since a crystalline aromatic polyester and a lactone are continuously subjected to addition polymerization and then continuously tube-molded, a highly viscous elastic polyester can be obtained in a short time. A high-quality elastic polyester tubular body having no property deterioration can be economically obtained.

[0016]

EXAMPLES The effects of the present invention will be described below with reference to examples. In the examples,% and parts are by weight unless otherwise specified. The relative viscosity (ηr) is a value obtained by measuring a 0.5% polymer solution at 25 ° C. using o-chlorophenol as a solvent. Physical properties shown in Examples and Comparative Examples were measured as follows.

Press molding: The obtained tubular body was molded at a molding temperature of 240 ° C. using a simple press molding machine manufactured by Tester Sangyo.
A JIS No. 2 dumbbell having a thickness of 2 mm was press-molded at a cooling temperature of 60 ° C.

Melt viscosity index (MI value): ASTM D-
According to 1238, it was measured at a temperature of 240 ° C. and a load of 2160 g.

Surface hardness: J obtained by the above press molding
The surface hardness was measured according to ASTM D-2240 method using IS2 dumbbell.

Tensile strength and elongation: ASTM D-638 using JIS No. 2 dumbbell obtained by the above press molding.
The mechanical properties of tensile strength and elongation were measured according to the method.

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

Examples 1 to 5 100 parts of polybutylene terephthalate pellets having a relative viscosity of 1.52 and an organotin compound of monobutylmonohydroxytin oxide were added to 0.0 using a vibrating feeder.
3 parts, triphenyl phosphite phosphorus compound 0.0
8 kg mixed pellets at 15 kg / h, manufactured by Japan Steel Works, 2-axis co-rotating intermeshing type extruder TEX44H (inner diameter 4
7 mmφ, L / D = 40), and ε-
TEX44 of caprolactone 5kg / h by metering pump
It was continuously supplied to the H supply port. Figure 1 is made by Japan Steel Works 2
Axial co-rotating mesh type extruder TEX44H (inner diameter 47
mmφ, L / D = 40), and this extruder is composed of an extruding section 8 and a discharging section 9. The extruding section 8 is provided with a supply port 1 and a vent port 4, and the vent of the extruding unit is A discharge part 9 is installed at the end on the side of the mouth 4, the internal pressure method tube molding die part 2 is provided in the discharge part 9, and the rotary shaft 7 penetrates the entire area of the extruder 8. FIG. 2 is a partially cutaway enlarged explanatory view of the extruding part 8. The rotating shaft 7 includes a large number of convex lens type or rice ball type kneading paddles 6 from the vent port 4 to the intermediate part, and from the supply port 1 to the intermediate part. A screw type paddle 5 is provided from the vent port 4 to the discharge part 9. 3 and 4 are cross-sectional explanatory views of the screw type paddle 5 and the kneading disc paddle 6, respectively. The cylinder of TEX44H is heated and controlled by 12 electric heaters (not shown) that are divided into 12 equal parts.
50 ° C, 250 ° C, 250 ° C, 250 ° C, 250 ° C, 2
50 ° C, 250 ° C, 250 ° C, 250 ° C, 230 ° C, 2
30 ° C., the die part 2 was set to 230 ° C., and the addition reaction was performed at a screw rotation speed of 70 rpm. At this time, carbon black powder was added from the supply port 1 and the average residence time was measured and found to be 4 minutes. Next, the molten polymer is extruded onto the cylinder through the tube part for forming an inner pressure tube 2 and cooled in water through a sizing plate to form a tube having an outer diameter of 8 mm and an inner diameter of 6 mm, and the elastic polyester tubular body (A- 1) was obtained.

Under the same conditions as in (A-1) above, an elastic polyester tubular body (A-2) containing no organotin compound and an elastic polyester tubular body containing no organotin compound and phosphorus compound. (A-3), an elastic polyester tubular body added with 0.03 part of tetrabutyl titanate instead of the organotin compound (A-4), and an elastic polyester tubular body similarly added with 0.03 part of antimony trioxide (A). -5) was obtained. Comparative Examples 1-2 75 parts of polybutylene terephthalate pellets having a relative viscosity of 1.52 and 25 parts of ε-caprolactone were charged in a reactor equipped with a helical ribbon stirring blade and purged with N ₂ ,
The mixture was heated and stirred at 250 ° C. for 20 minutes to carry out addition polymerization, then discharged from the reactor in a gut form into water and pelletized through a cutter. Then, after vacuum drying the pellets,
From a single-screw extruder heated to 230 ° C. and having a diameter of 45 mmφ and L / D = 25, the molten polymer was extruded onto a cylinder through an internal pressure method tube forming die, cooled in water through a sizing plate, An elastic polyester tubular body (A-6) having the same diameter as in Example 1 was obtained. Also, an elastic polyester tubular body (A-7) having a reaction time of 60 minutes
Got

Table 1 shows the melting point, melt viscosity index (MI) and mechanical properties of the elastic polyesters obtained in the above Examples and Comparative Examples.

[0025]

[Table 1]

From Table 1, Comparative Example 1 (A
Since the reaction time of the elastic polyester tubular body of -6) is short, an elastic polyester tubular body is not obtained. Similarly, the elastic polyester tubular body of Comparative Example 2 (A-7) obtained in the polymerization tank required a long reaction time, and since it was tube-formed into the elastic polyester tubular body, the melting point was lowered by remelting. And is inferior in thermal stability. Therefore, it is clear that the elastic polyester tubular bodies of Examples 1 to 5 (A-1 to A-5) of the present invention have excellent mechanical properties and thermal stability, and can be obtained continuously and in a short time. Further, Example 1 (A-1) in which an organotin compound and a phosphorus compound were used in combination.
It is apparent that the elastic polyester tubular body of 1 can obtain an elastic polyester tubular body excellent in mechanical properties and thermal stability in a shorter time.

Example 6 Polybutylene terephthalate 100 having a relative viscosity of 1.52
Parts, 0.03 parts of an organotin compound of monobutylmonohydroxytin oxide, and 0.08 parts of a phosphorus compound of triphenyl phosphite are mixed to obtain a pellet of 12 kg / h.
Then, the supply amount of ε-caprolactone was continuously supplied at 8 kg / h, and addition polymerization and tube molding were performed in the same manner as in Example 1 to obtain an elastic polyester tubular body (A-8). The melting point of the obtained polymer was 184 ° C., the surface hardness was 50 D, the tensile strength was 31 MPa, and the elongation was 540%. From this,
It is apparent that elastic polyester tubular bodies having different hardness can be obtained in the same manner as in Example 1.

[0028]

INDUSTRIAL APPLICABILITY The present invention is a known method for obtaining an elastic polyester tubular body of a crystalline aromatic polyester and a lactone compound, because the addition polymerization reaction time is significantly shortened by continuous addition polymerization. It is possible to easily and economically and continuously obtain a stable elastic polyester in a simplified device such as an extruder other than the reactor, and by attaching a tube forming die to the extruder, it is possible to continuously produce it without remelting. It is possible to obtain an elastic polyester tubular body. Further, since it is excellent in thermal stability, it can be expected to be excellent in recyclability, and it is expected that applications of the elastic polyester as a thermoplastic elastomer tubular body which can be stably molded will be expanded.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of a twin-screw extruder used in an example of the present invention.

FIG. 2 is an enlarged explanatory view of a discharge part and a central part of the twin-screw extruder shown in FIG.

FIG. 3 is a cross-sectional explanatory view of a screw type paddle of the discharge part shown in FIG.

4 is a cross-sectional explanatory view of the kneading disc paddle 6 shown in FIG.

[Explanation of symbols]

1 supply port 2 Tube forming die 3 outlets 4 vent 5 screw type paddle 6 Kneading disc paddle 7 rotation axis 8 Extruder 9 Discharge part

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Claims (2)

[Claims] 1. An elastic polyester tubular body obtained by continuously subjecting a crystalline aromatic polyester and a lactone compound to addition polymerization, and then continuously tube-forming. 2. The elastic polyester tubular body according to claim 1, wherein the addition polymerization is carried out in the presence of an organotin compound and a phosphorus compound.