JP3083136B2 - Polyester resin composition and use thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition of a polyester copolymer, and more particularly, to a polyester resin composition useful for a polyester elastomer film having excellent moisture permeability and swelling resistance, and the film. .

[0002]

2. Description of the Related Art A polyester-polyether type block copolymer comprising a polyester of an aromatic dicarboxylic acid and an aliphatic glycol as a hard segment and a poly (alkylene oxide) glycol as a soft segment is provided with cold resistance, heat resistance and oil resistance. Used as a saturated polyester elastomer with excellent heat resistance, bending fatigue resistance, and mechanical strength in automotive parts, industrial parts, electric and electronic parts, etc., recently, utilizing the moisture permeability of the copolymer. In addition, it is also used for applications such as a moisture-permeable film, and its use is expanding in relation to waterproof and moisture-permeable clothing.

For example, Japanese Patent Publication No. 1-48872 discloses a polyester film having a short-chain ester unit content of 50 to 70% by weight.

[0004]

However, since the above-mentioned polyester film contains 50% by weight or more of short-chain ester units, it has excellent swelling resistance.
It is difficult to ensure sufficient moisture permeability and flexibility, and a polyester elastomer film satisfying all of swelling resistance, moisture permeability, flexibility and the like is desired.

[0005]

The present inventor has conducted intensive studies in view of the above circumstances. As a result, the hard segment (A1) of the aromatic polyester unit was 20 to 50% by weight and the carbon / oxygen atom ratio was 2%. 20 to 50% by weight of a polyester resin (A) obtained by condensing 50 to 80% by weight of a soft segment (A2) composed of a polyalkylene oxide glycol represented by the formula: % By weight and a polyester resin (B) obtained by condensing 50 to 80% by weight of a soft segment (B2) composed of a polyalkylene oxide glycol having a carbon / oxygen atom ratio of 3.0 to 4.0. The present inventors have found that a polyester resin composition is suitable for obtaining the above film, and have completed the present invention.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The polyester resin composition of the present invention is obtained by mixing a polyester resin (A) and a polyester resin (B). The polyester resin (A) has a hard segment (A1) of an aromatic polyester unit of 20 to A soft segment (A2) composed of 50% by weight and a polyalkylene oxide glycol having a carbon / oxygen atom ratio of 2.0 to 2.9 is condensed by 50 to 80% by weight, and more specifically, A polyester resin obtained by polycondensation of an aromatic dicarboxylic acid, an alkylene glycol and a polyalkylene oxide glycol having a carbon / oxygen atom ratio of 2.0 to 2.9. The aromatic dicarboxylic acid is mainly terephthalic acid. Acids and lower alkyl esters thereof are used. Others include isophthalic acid, phthalic acid, 2,5-nor Nonanedicarboxylic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, 4,4-but-oxybenzoate and the like their lower alkyl esters,
Among them, dimethyl terephthalate is particularly preferred in view of the availability of the raw material, the high rate of polyesterification, and the effect on polyether (no acid decomposition).

The alkylene glycols include ethylene glycol, propylene glycol, 1,
3-butylene glycol, 1,4-butanediol,
Examples thereof include 1,6-hexanediol and the like, and among them, 1,4-butanediol is particularly preferable because it shows good crystallinity. Further, examples of the polyalkylene oxide glycol having a carbon / oxygen atom ratio of 2.0 to 2.9 include polyethylene glycol and an ethylene oxide adduct of polypropylene glycol, and polyethylene glycol is preferably used.

[0008] The polyester resin composition of the present invention can be produced by a usual copolymerization method using the above-mentioned components. That is, an aromatic dicarboxylic acid, an alkylene glycol and a poly (alkylene oxide) glycol are reacted.
An ester reaction occurs between the aromatic dicarboxylic acid and the alkylene glycol and between the aromatic dicarboxylic acid and the poly (alkylene oxide) glycol, followed by polycondensation to produce a polyester copolymer (saturated polyester elastomer). In the above reaction, a catalyst is used, and the catalyst is a titanium-based catalyst, and specific examples thereof include tetraisopropyl titanate and tetra-n-butyl titanate, and preferably tetra-n-butyl titanate. Is used. Also, two or more of these catalysts may be used in combination, and the catalyst may be added at once, but it is better to add them separately during the ester reaction and during the polycondensation reaction. The ratio of the amount is 1/1 to 1
It is preferable to carry out in the range of 0.

The polyester resin (A) of the present invention is obtained by the above method. In the present invention, the hard segment (A1) of the aromatic polyester unit in the obtained polyester resin (A) is used. 20 to 50% by weight, and the soft segment (A2) composed of a polyalkylene oxide glycol having a carbon / oxygen atom ratio of 2.0 to 2.9 is required to be 50 to 80% by weight.
When the condensation ratio of (A1) is less than 20% by weight or the condensation ratio of (A2) exceeds 80% by weight, the moldability is significantly reduced,
Conversely, if the condensation ratio of (A2) is less than 50% by weight or the condensation ratio of (A1) exceeds 50% by weight, the flexibility and moisture permeability of the molded product are reduced, and the object of the present invention cannot be achieved. .

In order to control the condensation ratio of (A1) and (A2), the amount of each material used in the above-mentioned production method is controlled by using an aromatic dicarboxylic acid or a lower alkyl ester thereof, an alkylene glycol and a polyalkylene oxide glycol. 1 / 0.5 to 2.0 / 0.05 in molar ratio
The ratio is preferably 0.6 to 0.6, and particularly preferably,
1 / 1.0 to 1.5 / 0.1 to 0.4. The amount of catalyst added per mole of aromatic dicarboxylic acid was 0.1.
0001 to 0.1 mol is preferred, and 1/1 / mol is particularly preferred.
0.001 to 0.01 mol.

The polyester resin (B) mixed with the polyester resin (A) can be produced in the same manner as the polyester resin (A). However, the polyalkylene oxide glycol used for the soft segment may be carbon / oxygen. It is necessary to use a polyalkylene oxide glycol having an atomic ratio of 3.0 to 4.0. Examples of the polyalkylene oxide glycol include polypropylene glycol, polytetramethylene glycol, and ethylene oxide adducts of polypropylene glycol. Preferably, polytetramethylene glycol is used. The polyalkylene oxide glycols used for the polyester resins (A) and (B) each have a molecular weight of 500 to 3000 (further 10
When the molecular weight is less than 500, the blockability of the soft segment is reduced, and the decrease in melting point and rubber elasticity are remarkable. It is not preferable because the compatibility is greatly reduced and the resin strength is adversely affected.

The polyester resins (A) and (B) obtained as described above are mixed to form the polyester resin composition of the present invention, but the mixing is not particularly limited. Examples of the method include melt-mixing, and dissolving and mixing both with an appropriate solvent, and then distilling off the solvent.Generally, both are directly melt-mixed with a single-screw or twin-screw extruder. Is adopted.

In the present invention, the mixing ratio of (A) and (B) is not particularly limited, but the mixing weight ratio (A / B) is 3
/ 2 to 1/7, more preferably 3/2 to 3/5. When the mixing weight ratio (A / B) is less than 1/7,
When the moisture permeability of the obtained molded product (such as a polyester elastomer film) is insufficient, and when it exceeds 3/2, the swelling resistance of the obtained molded product is undesirably reduced. In addition, the polyester resin composition preferably contains 10 to 30% by weight of the soft segment (A2) derived from the polyester resin (A) in the polyester resin composition after mixing, and the content is 10% by weight. %, The moisture permeability of the obtained molded product is insufficient, and if it exceeds 30% by weight, the swelling resistance of the obtained molded product is undesirably reduced.

The polyester resin composition of the present invention comprises:
If necessary, antioxidants such as hindered phenols, heat stabilizers, alkali metal compounds, crystal nucleating agents such as talc, glass fibers, flame retardants, ultraviolet absorbers, coloring agents, etc. can be blended. Such compounding can be performed either at the time of the reaction or after the reaction. Thus, the polyester resin composition of the present invention is obtained, but in the present invention,
It is useful to make such a resin composition into a film to form a polyester elastomer film, and such a film will be described.

The above-mentioned polyester elastomer can be formed into a film (or sheet) by melt-forming the above-mentioned composition according to a well-known method. The thickness of the film is not particularly limited and can be set to several μm to several hundred μm.
It is 50 μm, particularly preferably 10 to 30 μm. The film obtained as described above is subjected to a moisture conditioning treatment such as moisture absorption or drying, if necessary, and then subjected to stretching. Stretching may be either uniaxial stretching or biaxial stretching. In the case of uniaxial stretching, it is preferably at least 1.5 times, particularly preferably at least 2 times. In the case of biaxial stretching, the area magnification is 1.5 times or more, especially 2 times.
It is preferably at least twice, more preferably at least four times. As a stretching method, a roll stretching method, a tenter stretching method, a stretching blow method, or the like can be employed. In the case of biaxial stretching, any of a simultaneous biaxial stretching method and a sequential biaxial stretching method can be adopted. In general, after such stretching, heat treatment or surface treatment such as corona discharge treatment can also be performed.

The polyester elastomer film thus obtained is excellent in swelling resistance, moisture permeability, flexibility, waterproofness, etc., and is used for medical purposes (base materials for medical aid tapes such as emergency bandages, surgical tapes, rehabilitation tapes, etc.). Very useful in base materials for tapes for treating diseases such as anti-inflammatory, analgesic, and promoting blood circulation, surgical gloves, etc., sanitary applications (base materials for fixing tape for disposable diapers, base materials for fixing napkins), sports clothing, etc. It is.

[0017]

The present invention will now be described more specifically with reference to examples. In Examples, “%” and “parts” mean “parts by weight” unless otherwise specified. Example 1 [Production of polyester resin (A)] In a reactor equipped with a stirrer, a thermometer, a gas injection port and a distillation port, under a nitrogen gas atmosphere, 22.2 parts of dimethyl terephthalate and 1,4-butanediol were used. 6 parts, 57.1 parts of polyethylene glycol having an average molecular weight of 2,000, 0.0015 parts of tetrabutyl titanate as a catalyst, and 0.1 part of a hindered phenol compound (Irganox 1330, manufactured by Ciba Geigy) as an antioxidant were charged at 210 ° C. After reacting in nitrogen gas for 2 hours, 7.2 parts of methanol was distilled off, and then 0.1 part of the hindered phenol compound and 0.0020 part of tetrabutyl titanate were added and the mixture was heated from 210 ° C. to 245 ° C. The temperature was raised in 90 minutes, and at the same time, the pressure of the reaction system was gradually reduced, and the reaction was carried out at a degree of vacuum of 1.0 Torr for 30 minutes. Next, the temperature of the reaction system was cooled to 230 ° C., and the reaction was continued. After 5 hours from the temperature rise, the system was returned to normal pressure, pelletized with a pelletizer, and pelletized polyester resin composition (A) (hard segment). (A1) 28.
4% by weight and a soft segment (A2) 71.6% by weight).

[Production of polyester resin (B)]
22.2 parts of dimethyl terephthalate in a reactor equipped with a thermometer, a gas inlet and a distillation port under a nitrogen gas atmosphere;
20.6 parts of 1,4-butanediol, average molecular weight 200
57.1 parts of polytetramethylene glycol 0, 0.0015 parts of tetrabutyl titanate as a catalyst, and 0.1 parts of a hindered phenol compound (Irganox 1330, manufactured by Ciba Geigy) as an antioxidant 2
6. The reaction was carried out at 10 ° C. for 2 hours in nitrogen gas,
After distilling out 2 parts, 0.1 part of the hindered phenol compound and 0.0020 part of tetrabutyl titanate are further added, and the temperature is raised from 210 ° C. to 245 ° C. for 90 minutes, and at the same time, the pressure of the reaction system is increased. The reaction was gradually reduced, and the reaction was performed at a degree of vacuum of 1.0 Torr for 30 minutes. Next, the temperature of the reaction system was set to 230 ° C.
The reaction was continued while cooling to 5 hours after the temperature was raised, the system was returned to normal pressure, pelletized with a pelletizer, and pelletized polyester resin composition (B) (hard segment (B1) 28.4% by weight, Soft segment (B2) 7
1.6% by weight).

The polyester resins (A) and (B) obtained above are melt-mixed at 190 ° C. with a single screw extruder so that the mixing weight ratio (A / B) becomes 3/5, and the mixture is pelletized. The polyester resin composition of the present invention was obtained. Next, the obtained pellets were screwed to a diameter of 40 mmφ and L / D = 28.
Lip opening 0.6mm, width 500 attached to the extruder
extruded at a temperature 50 ° C. higher than the melting point of the resin using a T-die having a diameter of 350 mm and a water circulating at 25 ° C.
Contact with the cooling roll, and withdraw at 10 m / min.
A 10 μm thick polyester elastomer film was obtained.

Using the obtained polyester-based resin composition pellets and polyester elastomer film,
The following evaluation was performed. (Hardness) The obtained pellets were processed with an injection molding machine to a diameter of 10
cm, 7 mm thick test piece, and shore (D)
Was measured at 20 ° C. (Swelling degree) The obtained polyester elastomer film was cut into 15 cm x 15 cm, and was cut at 40 ° C and 90% RH.
The area of the film before and after the standing was measured, and the area (relative value) after the standing was determined with the area before the standing as 100. (Moisture Permeability) Using the obtained polyester elastomer film, it was measured in accordance with the JIS Z 0208 CUP method.

Example 2 [Production of polyester resin (A)] In a reactor equipped with a stirrer, a thermometer, a gas inlet and a distillation port, 31.1 parts of dimethyl terephthalate and an average molecular weight of 1 were placed under a nitrogen gas atmosphere.
000 polyethylene glycol 40.0 parts, 1,4-
28.9 parts of butanediol, 0.0015 part of tetrabutyl titanate as a catalyst, and 0.1 part of a hindered phenolic compound (manufactured by Ciba Geigy; Irganox 1330) as an antioxidant were charged at 210 ° C. in a nitrogen gas atmosphere. After reacting for 10 hours and distilling 10.1 parts of methanol,
Further, 0.05 parts of the hindered phenol compound and 0.0020 parts of tetrabutyl titanate were added to add 210 parts.
The temperature was raised from 90 ° C. to 245 ° C. in 90 minutes, and at the same time, the pressure of the reaction system was gradually reduced, and the reaction was carried out at a vacuum of 1.0 Torr for 30 minutes. Next, the temperature of the reaction system was cooled to 230 ° C., and the reaction was continued. After 4.5 hours from the temperature increase, the system was returned to normal pressure, and pelletized with a pelletizer. (44.2% by weight of hard segment (A1), 55.50% of soft segment (A2)).
8% by weight).

[Production of polyester resin (B)]
31.1 parts of dimethyl terephthalate in a nitrogen gas atmosphere in a reactor equipped with a thermometer, a gas injection port and a distillation port,
Polytetramethylene glycol 4 having an average molecular weight of 1,000
0.0 part, 28.9 parts of 1,4-butanediol, 0.0015 part of tetrabutyl titanate as a catalyst, and 0.1 part of a hindered phenolic compound (manufactured by Ciba Geigy; Irganox 1330) as an antioxidant The reaction was carried out at 210 ° C. in a nitrogen gas for 2 hours.
After distilling out 0.1 part, 0.05 part of the hindered phenol compound and 0.0020 of tetrabutyl titanate were further added.
And the temperature was raised from 210 ° C. to 245 ° C. in 90 minutes.
The reaction was performed at orr for 30 minutes. Next, the temperature of the reaction system was cooled to 230 ° C., and the reaction was continued.
After 5 hours, the system was returned to normal pressure, pelletized with a pelletizer, and pelletized polyester resin composition of the present invention (hard segment (B1) 44.2% by weight, soft segment (B2) 55.8% by weight) ) Got. The polyester resin (A) and (B) obtained above are mixed at a weight ratio (A
(B) was melt-mixed at 200 ° C. with a single screw extruder so as to be 1/1 to obtain a pellet-shaped polyester resin composition of the present invention. Example 1 was prepared using the obtained resin composition.
The evaluation was performed in the same manner as described above.

Example 3 In Example 1, the polyester resins (A) and (B)
Dimethyl terephthalate 27.3
Parts, 2,5.4 parts of 1,4-butanediol,
In the production of the polyester resin (A), 47.3 parts of polyethylene glycol having an average molecular weight of 1450 was used,
In the production of the polyester resin (B), polytetramethylene glycol having an average molecular weight of 1400 was used.
Polyester resin (A) (37.1% by weight of hard segment (A1), 62.9% by weight of soft segment (A2)) / polyester resin (B) except that the reaction was carried out using 3 parts. (Hard segment (B1) 37.1
After obtaining a polyester resin composition in which the weight ratio of the soft segment (B2) was 62.9% by weight) was 4/5 (weight ratio), the same evaluation was performed.

Comparative Example 1 [Production of polyester resin (A)] in Example 1
The polyester resin (A) (hard segment) was prepared in the same manner except that the reaction was carried out using 42.7 parts of dimethyl terephthalate, 39.7 parts of 1,4-butanediol and 17.6 parts of polyethylene glycol having an average molecular weight of 1,000. (A1) 72.7% by weight, soft segment (A2)
3% by weight) to obtain a polyester-based resin composition in the same manner. However, when mixed with the polyester resin (B), the mixing property between the resins is greatly reduced, and phase separation is caused. The resin composition could not be obtained, and was not evaluated.

Comparative Example 2 In Example 1, [Production of polyester resin (A)]
The reaction was carried out using 12.3 parts of dimethyl terephthalate, 11.5 parts of 1,4-butanediol and 76.2 parts of polyethylene glycol having an average molecular weight of 2,000, but the obtained resin did not show clear crystallinity. It was impossible to mold, good pellets could not be obtained, and no evaluation was performed.

Comparative Example 3 In Example 1, [Production of polyester resin (B)]
The polyester resin (B) was prepared in the same manner except that the reaction was carried out using 42.7 parts of dimethyl terephthalate, 39.7 parts of 1,4-butanediol, and 17.6 parts of polytetramethylene glycol having an average molecular weight of 1,000. 72.7% by weight of hard segment (B1), soft segment (B2)
27.3% by weight) to obtain a polyester resin composition in the same manner. However, when mixed with the polyester resin (A), the mixing property between the resins is greatly reduced, causing phase separation. A good resin composition could not be obtained, and no evaluation was performed.

Comparative Example 4 In Example 1, [Production of polyester resin (B)]
The reaction was carried out using 12.3 parts of dimethyl terephthalate, 11.5 parts of 1,4 butanediol, and 76.2 parts of polytetramethylene glycol having an average molecular weight of 2,000, but the obtained resin did not show clear crystallinity. No molding was possible, good pellets could not be obtained, and no evaluation was performed.

Comparative Example 5 In Example 1, [Production of polyester resin (A)]
A polyester resin (A) (hard segment (A1) 28.4% by weight, soft segment (A2) 71.6% by weight was obtained in the same manner except that polyethylene glycol was changed to polytetramethylene glycol. After obtaining the polyester-based resin composition, the same evaluation was performed.

Comparative Example 6 In Example 1, [Production of polyester resin (B)]
Polyester resin (B) (28.4% by weight of hard segment (B1) and 71.6% by weight of soft segment (B2) were obtained in the same manner except that polytetramethylene glycol was changed to polyethylene glycol. After obtaining the polyester-based resin composition, the same evaluation was performed.
Table 1 shows the evaluation results of the examples and the comparative examples.

[0030]

[Table 1] * Unit of moisture ^{permeability, g / m 2 · 24h ·} 10μm

[0031]

The polyester resin composition of the present invention comprises:
Excellent in swelling resistance, moisture permeability, flexibility, waterproofness, etc., the polyester elastomer film obtained from such a resin composition is used for medical applications (base materials for medical auxiliary tapes such as emergency bandages, surgical tapes, rehabilitation tapes, etc. Pain relief
It is also very useful in base materials for tapes for treating diseases such as blood circulation promotion, surgical gloves, etc., sanitary uses (base materials for fixing tapes for disposable diapers, base materials for fixing napkins), and sports clothing.

Claims (5)

(57) [Claims] 1. A soft segment (A2) comprising a polyalkylene oxide glycol having a hard segment (A1) of 20 to 50% by weight of an aromatic polyester unit and a carbon / oxygen atom ratio of 2.0 to 2.9. 50 to 80% by weight of the polyester resin (A) and the aromatic polyester unit hard segment (B1) of 20 to 5%
0% by weight and a polyester resin (B) obtained by condensing 50 to 80% by weight of a soft segment (B2) comprising a polyalkylene oxide glycol having a carbon / oxygen atom ratio of 3.0 to 4.0 are mixed. A polyester resin composition characterized by comprising: 2. The polyester resin composition according to claim 1, wherein the mixing weight ratio (A / B) of the polyester resin (A) and the polyester resin (B) is 3/2 to 1/7. . 3. The polyester resin composition according to claim 1, wherein the content of the soft segment (A2) in the polyester resin composition after mixing is 10 to 30% by weight. 4. The polyester resin composition according to claim 1, wherein the molecular weight of the polyalkylene oxide glycol is from 500 to 3,000. 5. A polyester elastomer film comprising the polyester resin composition according to claim 1.