JPH05155996A - Production of elastic polyester - Google Patents

Abstract

PURPOSE:To efficiently and speedily produce a stable elastic polyester of high quality having excellent mechanical properties and thermal stability by the continuous addition polymerization of a crystalline aromatic polyester and a lactone compound. CONSTITUTION:This production process is effected by the continuous addition polymerization of a crystalline aromatic polyester and a lactone compound, wherein the water content of the lactone compound is kept at 300ppm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an elastic polyester having a crystalline aromatic polyester as a hard segment and a polylactone as a soft segment. More specifically, the present invention relates to a method for producing an elastic polyester, which is capable of stably obtaining a highly viscous elastic polyester in a short time and has excellent mechanical properties.

[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, and can be processed by injection molding, extrusion molding, or other processing methods. Widely used in parts, electric / electronic parts, machine parts, etc. The elastic polyester of this 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
Japanese Patent Publication, Japanese Patent Publication No. 52-49037, Japanese Patent Laid-Open Publication No. 61-
281124, JP 61-283619, JP 61-287922, and JP 62-2.
It is disclosed in Japanese Patent Application Laid-Open No. 0525, Japanese Patent Application Laid-Open No. 62-27425, Japanese Patent Application Laid-Open No. 62-53336, and the like.

[0003]

However, the production method of the above-mentioned known example is economically inferior because the reaction time is long, and the elastic polyester obtained by this method has a fragrance which constitutes the hard segment. Since the group-polyester and the polylactone forming the soft segment have a long reaction time, they are partially randomized by a transesterification reaction, and an elastic polyester having poor heat resistance and mechanical strength can be obtained. In the apparatus for continuously producing elastic polyester of the present invention,
Since the lactone compound has water absorbency, when it is manufactured for a long time, the viscosity of the elastic polyester gradually decreases with an increase in the amount of water in the lactone compound, and an elastic polyester having a stable viscosity cannot be obtained. Therefore, it is possible to obtain an elastic polyester whose physical properties gradually decrease in heat resistance and mechanical strength as the viscosity decreases. Further, when a lactone compound having a large amount of water is used, the viscosity is reduced as in the above case, resulting in an elastic polyester having poor heat resistance and mechanical strength. An object of the present invention is to solve the above problems and efficiently obtain a high-quality stable elastic polyester.

[0004]

[Means for Solving the Problems] That is, according to the present invention, when a crystalline aromatic polyester and a lactone compound are continuously added and polymerized to produce an elastic polyester, the water content in the lactone compound is adjusted to 300 ppm or less in advance. The present invention provides a method for producing an elastic polyester characterized by being maintained.

The elastic polyester is a polyester-polyester block copolymer obtained by addition-polymerizing a crystalline polyester and a lactone compound.

In the present invention, the crystalline aromatic polyester is a polymer having an ester bond with at least one kind of aromatic group in the main repeating unit, such as 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 resulting 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 mechanical properties of the obtained polyester-polyester block copolymer, and the crystalline aromatic polyester / lactone 9 by weight of compound
9/1 to 20/80 are preferable, and 98 is particularly preferable.
/ 2 to 30/70.

In the present invention, a catalyst is not particularly required, but an organic tin compound and a phosphorus compound can be used 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. Be done. 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 diaryl tin compounds such as dibutyl tin maleate, dibutyl tin diacetate and diphenyl tin oxide are effective and are preferably used. The amount of tin compound added is preferably 0.001 to 0.5% by weight, based on the elastic polyester of the polyester-polyester block copolymer, as an 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 of adding it at the time of producing the crystalline aromatic polyester, a method of adding it when supplying the crystalline aromatic polyester and the lactone compound to the reactor, and the like are adopted. ..

As the phosphorus compound, phosphoric acid, phosphorous acid,
Pentavalent phosphorus compounds such as phosphonic acid, phosphinic acid, phosphoric acid ester, phosphite ester, phosphonic acid ester, and phosphinic acid ester, and trivalent phosphorus compounds such as phosphinic acid, phosphinauic acid, phosphine, phosphonite, phosphinite, and phosphite Examples thereof include phosphorus compounds, phosphorus compounds containing different elements, vinyl group-containing phosphorus compounds, 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, and 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 supplied to the reactor. The method of adding to the elastic polyester after the addition polymerization reaction is adopted.

In the elastic polyester of the present invention, known hindered phenol-based, thioether-based, amine-based antioxidants, benzophenone-based, hindered amine-based weathering agents and the like are used within a range that does not impair the object of the present invention. , Fluorine-containing polymers, silicone oil, stearic acid metal salt, montanic acid metal salt, montanic acid ester wax, release agent such as polyethylene wax, epoxy compound, carbodiimide compound, bisoxazoline compound, acyllactam compound, isocyanate compound, etc. Thickeners, coloring agents 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, glass. Filling beads Agents, nucleating agents such as talc, flame retardants, plasticizers, adhesives, adhesion promoters, can be allowed to optionally contain an adhesive or the like,. 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, or may be blended with the elastic polyester after the addition polymerization reaction.

In the present invention, the method of continuously carrying out addition polymerization is preferably a method of continuously carrying out addition polymerization using one or more extruders, and the extruders are single-screw extruders, twin-screw extruders and mixer type extruders. Examples of the extruder include a kneader type extruder. The method for supplying the crystalline aromatic polyester and the lactone compound is not particularly limited, but (1) the method for simultaneously supplying the crystalline aromatic polyester and the lactone compound in the solid state from the supply port, and (2) the crystalline polyester in the solid state A method for supplying a lactone compound from a supply port through a supply port, (3) a method for simultaneously supplying a crystalline aromatic polyester in a molten state and a lactone compound through a supply port, and (4) a crystalline polyester in a molten state through a supply port. , A method of supplying a lactone compound from a vent port,
(5) A method in which the crystalline polyester and the lactone compound are melt-mixed in advance and then supplied can be adopted. The conditions for addition polymerization in the extruder are 210 to 210.
At a temperature of 280 ° C, preferably 215-270 ° C, the residence time in the extruder is 1-30 minutes, preferably 1.5-20.
Minutes. Furthermore, as a method for removing the lactone compound monomer present in the polymer obtained by addition polymerization,
(1) A method of removing a lactone compound monomer at a vacuum degree of 50 Torr or less, preferably 10 Torr or less by providing a vent port at the tip of an extruder used in addition polymerization.
(2) The polymer obtained by the addition polymerization is fed to an extruder having a vent port in a solid or molten state, and the lactone compound monomer is heated at a temperature of the melting point of the polymer or higher and a vacuum degree of the vent port of 50 Torr or less, preferably 10 Torr or less. And a method of removing.

As a method for removing water in the lactone compound of the present invention, (1) a method for removing water by passing the lactone compound through a cylinder containing a molecular sieve.
(2) A method of directly adding a molecular sieve to a lactone compound to remove water. (3) Metal Na, NaH, Ca
A method in which water is removed using a metal compound such as H ₂ and then distilled. (1) and (2) are preferable as a simple method.

[0018]

In the present invention, when a crystalline aromatic polyester and a lactone are continuously added and polymerized to produce an elastic polyester, the water content of the lactone compound is set to 300 pp in advance.
By maintaining the value of m or less, a stable and highly viscous elastic polyester can be efficiently obtained in a short time, and a high-quality elastic polyester excellent in mechanical properties and heat resistance can be stably produced.

[0019]

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 measured at 25 ° C. in a 0.5% polymer solution using o-chlorophenol as a solvent. Physical properties shown in Examples and Comparative Examples were measured as follows.

Test piece: The elastic polyester obtained was processed into a JIS No. 2 dumbbell by an injection molding machine.

Melt viscosity index (MI value): ASTM D-1238 was prepared using the obtained elastic polyester pellets.
The temperature was 240 ° C. and the load was 2160 g.

Surface hardness: Using the JIS No. 2 dumbbell, the surface hardness was measured according to the ASTM D-2240 method.

Tensile Strength and Elongation: Using the above JIS No. 2 dumbbell, the mechanical properties of tensile strength and elongation were measured according to the ASTM D-638 method.

Melting point: about 5 mg of elastic polyester 10
It was measured by a DSC (differential scanning calorimeter) at a temperature rising rate of ° C / min.

Water content: The water content in ε-caprolactone was measured with a Karl Fischer water content measuring instrument.

Example 1 100 parts of pellets of polybutylene terephthalate having a relative viscosity of 1.52 and 0.0 parts of an organotin compound of monobutylmonohydroxytin oxide were added 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 the water content of 10 which was passed through a packed column filled with molecular sieves.
5 ppm of ε-caprolactone at 5 kg /
It was continuously supplied to the supply port of the same TEX44H at h. Figure 1
Is a two-shaft co-rotating intermeshing type extruder TEX manufactured by Japan Steel Works
44H is an overall explanatory view of 44H (inner diameter 47 mmφ, L / D = 40), and this extruder is composed of an extrusion section 8 and a discharge section 9, and the extrusion section 8 is provided with a supply port 1 and a vent port 4.
A discharge part 9 is installed at the end of the extrusion part on the vent port 4 side, a die part 2 is provided in the discharge part 9, and a rotary shaft 7 penetrates the entire area of the extruder 8. FIG. 2 is a partially cutaway enlarged explanatory view of the extruding section 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 portion, and the supply port 1 to the intermediate portion. 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. Also, the cylinder part of this TEX44H is 12
Heating is controlled by 12 equally divided electric heaters (not shown).
℃, 250 ℃, 250 ℃, 250 ℃, 250 ℃, 250
℃, 250 ℃, 250 ℃, 250 ℃, 230 ℃, 230
C. Further, the die part 2 was set to 230.degree. C., and the addition reaction was performed at a screw rotation speed of 70 rpm. At this time, supply port 1
The carbon black powder was added and the average residence time was measured and found to be 4 minutes. Next, the molten polymer was discharged in a gut form through the die part 2 and then pelletized by a cutter through a cooling bath to obtain an elastic polyester (A-1).

Example 2 In a 18 L can, 2 kg of molecular sieve and 13 kg of ε-
An elastic polyester (A-2) was obtained under the same conditions as in Example 1 except that ε-caprolactone having a water content of 65 ppm which had been charged with caprolactone and left stirring at room temperature for 1 day was used.

Example 3 100 g of CaH ₂ and 14 kg of ε-caprolactone were charged into an 18 L can and left at room temperature for 1 day, then ε-caprolactone was distilled by a distillation apparatus to obtain a water content of 23 pp.
m of ε-caprolactone was obtained. An elastic polyester (A-3) was obtained under the same conditions as in Example 1 except that this ε-caprolactone was used.

Comparative Example 1 An elastic polyester (A-4) was obtained under the same conditions as in Example 1 except that ε-caprolactone having a water content of 450 ppm was used.

Comparative Example 2 18% of the above-mentioned ε-caprolactone having a water content of 450 ppm was used.
After being placed in a poly bucket of L and allowed to stand at room temperature for 2 days, the water content of ε-caprolactone was 850 ppm. Under the same conditions as in Example 1 except that ε-caprolactone having a water content of 850 ppm was used, the elastic polyester (A-
5) was obtained.

Comparative Examples 3 to 4 75 parts of polybutylene terephthalate pellets having a relative viscosity of 1.52, 25 parts of ε-caprolactone, and an organotin compound of monobutylmonohydroxytin oxide 0.0
3 parts, triphenylphosphite tonoline compound 0.08
Part was charged into a reactor equipped with a helical ribbon blade, purged with N ₂ , heated and stirred at 240 ° C. for 10 minutes to carry out addition polymerization, discharged from the reactor into water in a gut form, and pelletized through a cutter. Polyester (A-6) was obtained. Further, an elastic polyester (A-7) obtained by addition polymerization for 60 minutes under the same conditions was obtained.

The melting point and melt viscosity index (MI) of the elastic polyesters obtained in Examples 1 to 3 and Comparative Examples 1 to 4 above,
The mechanical properties are shown in Table 1.

[0033]

[Table 1] From Table 1, the inertial polyesters of Comparative Examples 1 to 2 (A-4 to A-5) using lactone compounds having a water content of more than 300 ppm cannot be obtained as elastic polyesters having a high MI value and a high viscosity. An elastic polyester having poor physical properties is obtained. Further, Comparative Example 3 (A-6) obtained in the polymerization tank
Since the reaction time of the elastic polyester is short, an elastic polyester has not been obtained. Similarly, the elastic polyester of Comparative Example 4 (A-7) obtained in the polymerization tank requires a long reaction time and a part of randomization proceeds, so that the melting point is lowered and the thermal stability is poor. Therefore, Examples 1 to 3 (A-
It is clear that the elastic polyesters of 1 to A-3) of the present invention are excellent in mechanical properties and thermal stability, and a stable elastic polyester of high quality can be obtained continuously and in a short time.

Example 4 Polybutylene terephthalate 100 having a relative viscosity of 1.52
Part, 0.03 part of an organotin compound of monobutylmonohydroxytin oxide, and 0.08 part of a phosphorus compound of triphenylphosphite are mixed, and a pellet of 12 kg /
At h, ε-caprolactone having a water content of 105 ppm used in Example 1 was continuously subjected to addition polymerization in the same manner as in Example 1 at a supply rate of 8 kg / h to obtain an elastic polyester (A-7). The polymer obtained has a melting point of 183 ° C. and a surface hardness of 50.
D, tensile strength was 30 MPa, and elongation was 550%. From this, it is clear that elastic polyesters having different hardness can be obtained in the same manner as in Example 1.

[0035]

INDUSTRIAL APPLICABILITY The present invention uses a lactone compound in which the water content in the lactone compound is maintained at 300 ppm or less in advance in a method of continuously adding a crystalline aromatic polyester and a lactone compound to obtain an elastic polyester. This makes it possible to easily and efficiently obtain a continuously stable elastic polyester in a simplified apparatus such as an extruder other than a known reactor. Further, since it is excellent in thermal stability, it can be expected to be excellent in recyclability, and it is expected that the use of elastic polyester will be expanded as a thermoplastic elastomer capable of stably molding high-quality elastic polyester.

[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 section and a central section 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.

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

[Explanation of symbols]

 1 Supply Port 2 Die Part 3 Discharge Port 4 Vent Port 5 Screw Type Paddle 6 Kneading Disc Paddle 7 Rotating Shaft 8 Extruding Section 9 Discharging Section

Claims (2)

[Claims] 1. When a crystalline aromatic polyester and a lactone compound are continuously added and polymerized to produce an elastic polyester, the water content in the lactone compound is set to 300 in advance.
A method for producing an elastic polyester, characterized in that the content is maintained at ppm or less. 2. The method for producing an elastic polyester according to claim 1, wherein a molecular sieve is used for removing water in the lactone compound.