JPH027964B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention has excellent mechanical properties, such as low-temperature impact strength, tensile strength, and elongation, and is suitable for manufacturing molded products.It also melts at a relatively low temperature and has excellent thermal stability when melted. This invention relates to a method for producing a copolymer that is excellent as a hot melt agent or a heat seal agent. That is, the present invention provides a terephthalate unit (Y) obtained from terephthalic acid or an ester-forming derivative thereof and a low molecular weight glycol having 2 to 10 carbon atoms or an ester-forming derivative thereof, an aromatic dicarboxylic acid other than terephthalic acid, or an ester thereof. Ester unit (Z) obtained from a forming derivative and a low molecular weight glycol having 2 to 10 carbon atoms or an ester forming derivative thereof and a molecular weight of 400 to 6000
The composition of the poly(alkylene oxide) glycol dicarboxylate unit (X) is A in FIG.
This is a method for producing a polyester/polyether block copolymer, which is characterized in that each component is mixed and reacted so as to fit into the area surrounded by points B, C, and D.

[Table] Polyester/polyether block copolymers mainly composed of terephthalic acid have been known and are useful as elastomers with excellent toughness and low-temperature flexibility, but on the other hand, they have a high melting temperature and It has poor thermal stability and has an unfavorable effect on melt molding. Copolymerized polyesters using terephthalic acid and other dicarboxylic acids are also known, but these copolymers are glassy or starch syrup-like and lack toughness, and are useful as adhesives, etc., but they cannot be used in molded products. It is inappropriate for However, since the block copolymer of the present invention melts at a relatively low temperature, it is not only easy to mold, but also has good thermal stability when melted, and the molded products obtained also have low-temperature impact strength and tensile strength. It has excellent mechanical properties such as strength and extensibility. Normally, copolymers have a lower melting temperature and lower mechanical properties than homopolymers, but it is surprising that the mechanical properties of the copolymer of the present invention hardly decrease. It is the right thing to do. In addition, the copolymer of the present invention has good thermal stability when melted and the film is strong, so it is useful as a hot melt agent or a heat sealing agent.It also has good solubility in solvents, so it can be used in solution type or emulsion. It is also useful as a mold paint and adhesive. Examples of terephthalic acid or its ester-forming derivatives used in the present invention include terephthalic acid, dimethyl terephthalate, terephthalic acid diglycol ester, and terephthalic acid chloride. Examples of low molecular weight glycols having 2 to 10 carbon atoms or ester-forming derivatives thereof used in the present invention include ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycol, and cyclohexane glycol. Examples include methanol and neopentyl glycol. Generally, ethylene glycol and tetramethylene glycol are preferred. The Y unit is obtained from the terephthalic acid component and the glycol component, and the ester unit other than the Y unit, that is, the Z unit, is a repeating unit in which the dicarboxylic acid component is different from the Y unit. Dicarboxylic acid components different from the above units include:
Aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 1,5-naphthalene dicarboxylic acid, 2,
Examples include 6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,2-di(4-carboxyphenoxy)ethane, and bis(4-carboxyphenyl)sulfone. As the glycol component, those mentioned above may be used. Poly(alkylene oxide) glycols having a molecular weight of 400 to 6,000 used in the method of the present invention include poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol, and mixtures thereof. Random or block copolymers of these polyether components can be mentioned. By combining the above compounds and reacting them in a specific ratio, the above-mentioned copolymer can be obtained.
The Y component and Z component mentioned above may be combined randomly or block-combined, but
They are usually combined randomly. Considering the composition of the copolymer of the present invention, the composition E or F in Figure 1 contains a large amount of poly(alkylene oxide) glycol dicarboxylate units, so the initial modulus of the molded article is small; It lacks toughness and has reduced resistance to thermal oxidation, resulting in poor thermal stability during melting as well as poor deterioration resistance at temperatures below the melting temperature. Since the copolymer near H does not contain poly(alkylene oxide) glycol dicarboxylate units or contains only a small amount of poly(alkylene oxide) glycol dicarboxylate units, when the Z unit is an aromatic ester unit, the elongation at yield is small and the netting behavior is poor. It exhibits significantly less behavior as an elastomer and has extremely poor low-temperature properties. Further, copolymers near G have a high melting point and are elastomers with excellent heat resistance, but they are not suitable for rotary molding, powder coating, etc. because of their high melting temperatures and poor heat resistance at molding temperatures. Furthermore, it is not suitable for solvent processing because it is releasable to common solvents. Furthermore, the copolymer near I has a low melting temperature because it has a small amount of polyalkylene terephthalate component.
Curing is slow and overall formability is poor. The polymer of the present invention can be produced by a conventional condensation polymerization method. A preferred method is to use dimethyl ester of terephthalic acid, one or more low molecular weight alkylene glycols having 2 to 10 carbon atoms, and other ester-forming derivatives such as dimethyl ester of aromatic dicarboxylic acids other than terephthalic acid, and poly(alkylene glycols). oxide) glycol in the presence of a transesterification polycondensation catalyst, about 150 to 240
In this method, a polyester copolymer is obtained by heating the prepolymer to a temperature of 0.degree. C., removing methanol formed by the transesterification reaction, and vacuum distilling excess low molecular weight alkylene glycol from the produced prepolymer. In order to smoothly proceed with the above polymerization reaction, it is preferable to use a transesterification polycondensation catalyst. Particularly effective ones include zinc acetate-antimony trioxide, magnesium acetate-antimony trioxide, calcium acetate-germanium dioxide,
Examples include potassium titanyl oxalate, tetra-iso-propyl titanate, tetra-n-butyl titanate, magnesium hexabutoxyhydrodiene titanate, and the like. Although the polymers of the present invention have many desirable properties as is, they can be further stabilized by adding various stabilizers. Useful stabilizers include substituted benzophenones, ultraviolet absorbers such as benzotriazole, hindered phenols, thiodipropionic acid esters, antioxidants such as aromatic amines and their derivatives, and hydrated polycarbodisides. There are decomposition stabilizers, etc. Furthermore, depending on the purpose, these polyester copolymers may contain antistatic agents, plasticizers,
Lubricants, flame retardants, etc. can be added. Furthermore, these polyester copolymers can be modified by adding powdered or fibrous fillers such as inorganic or organic pigments, glass fibers, carbon fibers, asbestos, calcium carbonate, finely powdered silica, and talc. It is. In particular, they can increase the elastic modulus of the material. The copolymer of the present invention usually has a melting point of 200°C or less, and therefore has sufficient fluidity at a molding temperature of about 220°C. Normally, this type of polymer has the disadvantage of rapidly deteriorating and becoming discolored when heated above 240°C in air, but the copolymer of the present invention has sufficient fluidity at temperatures below 220°C, so it does not deteriorate. Roll molding, press molding, calendar processing, melt casting molding, powder coating, etc. can be performed with almost no occurrence. Furthermore, since the molten polymer cures quickly, it can be molded using various molding methods such as injection molding, extrusion molding, and blow molding. Furthermore, the polymer of the present invention is capable of high frequency bonding. In addition, the copolymers of the present invention are not only soluble in solvents at relatively high concentrations and are suitable for various solvent processing, but also provide stable emulsions, which enable emulsion processing and can be used in a wide range of applications. The present invention will be explained in more detail below using Examples. In the present invention, various properties were measured by the following methods. (1) Crystal melting point: 1℃/1℃ using a micro melting point meter (Yanagimoto Manufacturing)
The temperature was increased at a rate of 1 minute, and the temperature at which a dark field appeared under a polarizing microscope was determined. (2) Solution viscosity Measurement was performed at 30° C. at a concentration of 0.2 g/100 c.c. using a mixed solvent of phenol:tetrachloroethane=6:4 to determine the reduced specific viscosity. (3) Flow start temperature Using a high-speed flow tester, the hole diameter is 1 mm and the length is
A 10 mm nozzle was attached and the temperature at which the discharge speed was 0.001 cm ² /sec when a pressure of 100 Kg/cm ² was applied was measured. (4) Tensile strength JIS K6301 method (5) Elongation at break Same as above (6) Brittle temperature Same as above (7) Surface hardness ASTM-D1484 method, JIS K6301 method Example 1 Poly(tetramethylene oxide) glycol
1050 parts (average molecular weight 1050) 1,4-butanediol 2025〃 Dimethyl terephthalate 2190〃 Dimethyl isophthalate 730〃 Tetrabutyl titanate 2.1〃 Ionox 330 (manufactured by Ciel) 8.5〃 Put the above substances into a polymerization pot and make polyester copolymer Combined _P1 was produced. The above substance was placed in an autoclave, purged with nitrogen, and then heated to bring the internal temperature to 250°C over 100 minutes. During this time, methanol was distilled out due to the transesterification reaction. After reaching 250°C, the pressure was gradually reduced to 0.1 mmHg or less for 100 minutes to carry out polycondensation. 120
Polycondensation under reduced pressure was completed in minutes, and the polymer was extruded into a strand from the autoclave under nitrogen pressure, and after cooling, it was pelletized. The solution viscosity of this product was ηsp/c=1.60. Comparative Example 1 Poly(tetramethylene oxide) glycol
1050 parts (average molecular weight 1050) 1,4-butanediol 2025〃 Dimethyl terephthalate 2910〃 Tetrabutyl titanate 2.1〃 Polyester copolymer Q ₁ was prepared from the above materials according to the method of Example 1. The solution viscosity of this product was ηsp/c=1.60. Table 1 shows the properties of the polyester copolymer P ₁ of the present invention and the comparative polymer Q ₁ .

[Table] The polyester copolymer P ₁ of the present invention exhibits excellent tensile strength and exhibits elastic behavior without any netting phenomenon, whereas the comparative polymer exhibits netting behavior and the strain is below the elongation at yield point. It only shows elastic behavior within 40%. Furthermore, polymer P ₁ is approximately
It can be thermally stably molded at around 220°C, but comparative polymer Q ₁ needs to be molded at an even higher temperature.
Prolonged exposure to air causes significant thermal oxidative deterioration.
Furthermore, the film obtained from polymer P ₁ has good heat sealability and high frequency adhesion, but compared to the comparative polymer
The heat-sealed part of the film from Q ₂ turns white.
High frequency bonding was not possible. Example 2

【table】

[Table] Polyester copolymer P ₂ and comparative polymers Q ₂ and Q ₃ were prepared from the above materials according to the method of Example 1. The respective solution viscosities are ηsp/c=1.72, 2.23,
It was 3.06. Their properties are shown in Table 2.

[Table] Q ₂ for compositions with too many poly(tetramethylene oxide) glycol dicarboxylate units,
Q ₃ has a low surface hardness and a low initial modulus, so it lacks toughness and its uses are limited, making it undesirable. On the other hand, the copolymer P ₂ of the present invention has appropriate toughness and is a resin suitable for all kinds of molding materials.

[Brief explanation of drawings]

Figure 1 shows the terephthalate unit (Y) of the present invention,
These are triangular coordinates showing the composition of three components: an ester unit (Z) other than the above Y unit and a poly(alkylene oxide) glycol dicarboxylate unit (X).

Claims (1)

[Scope of Claims] 1. A terephthalate unit (Y) obtained from terephthalic acid or its ester-forming derivative and a low molecular weight glycol having 2 to 10 carbon atoms or its ester-forming derivative, an aromatic dicarboxylic acid other than terephthalic acid, or An ester unit (Z) obtained from the ester-forming derivative and a low molecular weight glycol having 2 to 10 carbon atoms or an ester-forming derivative thereof, and a poly(alkylene oxide) glycol dicarboxylate unit (X) having a molecular weight of 400 to 6000. 1. A method for producing a thermoplastic polyester copolymer, which comprises blending and reacting each component so that the composition thereof is surrounded by points A, B, C, and D in FIG. 【table】