JPH0967509A - Polyester composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester composition which has excellent moldability and can give a film excellent in slipperiness, abrasion resistance and scratch resistance by using internal deposition type particles having a specified particle diameter and a specified particle diameter distribution. SOLUTION: This polyester composition contains internal deposition type particles prepared by performing the reaction for producing a polyester in the presence of 0.05-3.0mol%, based on the total dicarboxylic acid component, total of an alkali metal compound and an hlkaline earth metal compound and 0.05-1.5mol%, based on the total dicarboxylic acid component, phosphorus compound to deposit particles during the reaction. Because the internal deposition type particles have a mean particle diameter of 0.5-10.0μm and an at least bimodal particle diameter distribution, this composition has excellent moldability such as fiber-forming properties and film-forming properties and can give a molding excellent in slipperiness and surface properties.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester composition. More specifically, it relates to a polyester composition suitable for obtaining yarns and films having excellent moldability such as yarn-forming property and film-forming property and slipperiness as a molded product and excellent surface characteristics.

[0002]

2. Description of the Related Art Generally, polyester represented by polyethylene terephthalate has excellent mechanical properties and chemical properties and is widely used as a molded product such as a film or a fiber. However, polyester has a problem that productivity is lowered due to lack of slipperiness when processed into a molded product. As a method for improving such a problem, it is usual to impart appropriate surface irregularities to the surface of the molded product to impart surface slipperiness to the molded product. And, as a method of allowing the fine particles to exist in the polyester composition,
Titanium oxide, silicon oxide, calcium carbonate, aluminum oxide, kaolinite, etc. as they are, or after pulverization and classification, a method of adding at the time of polyester production or molding, a part of catalysts or anti-coloring agents used during polyester production, or A method is known in which all of them are deposited as fine particles during the production of polyester during the reaction.

However, although the above-mentioned addition method is effective in solving the problem of slipperiness, when it is used as a molded product, the abrasion resistance and scratch resistance cannot be made to a satisfactory level. In order to satisfy the sliding property and the abrasion resistance and the scratch resistance, for example, JP-A-7-70 is used.
415, JP-A-7-57964, and JP-A-6
No. 84445, Japanese Unexamined Patent Publication No. 6-279599 and the like disclose a method of blending two or more kinds of particles or particles having a particle size. However, such a method also provides good slipperiness and scratch resistance. I couldn't be satisfied.

When the abrasion resistance of a molded product, for example, a film for a magnetic tape is low, abrasion powder of the film is apt to be generated during the manufacturing process of the magnetic tape, and a coating omission occurs in the process of applying the magnetic layer. As a result, the magnetic recording may drop out. In addition, when using a magnetic tape, in most cases, it travels while contacting with recording and reproducing equipment, etc., so abrasion powder generated at the time of contact adheres to the magnetic material and drops (drops) in magnetic recording during recording and reproducing. Out). If the scratch resistance of the molded product, for example, the film for magnetic tape, is low, foreign matter is generated during the manufacturing process of the magnetic tape, and easily scratches the surface of the film, resulting in loss of magnetic recording (drop-out). ), Etc., or easily scratch the film surface when the magnetic tape runs at high speed. That is, the film for a magnetic tape is required to have not only slipperiness but also abrasion resistance and scratch resistance both during the magnetic tape manufacturing process and when used as a magnetic tape.

On the other hand, a method for depositing fine particles in the polyester production process using the above-mentioned metal compound residue is disclosed in JP-A-48-61556 and JP-A-51-11.
No. 2860, No. 53-25694, No. 53-113868, No. 57-83524
Many applications have been filed such as Japanese Patent Publication No. 59-126456. The polymer obtained by such a method contains internal precipitation type particles having a good affinity with polyester, and therefore has the characteristics of being excellent in abrasion resistance and scratch resistance, while the particle size distribution is Since it had a single peak, the slipperiness could not be satisfied.

[0006]

However, such prior art yarns and films still have insufficient slipperiness and surface properties. In particular, the film was inferior in abrasion resistance and scratch resistance.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. When a polyester containing internally precipitated particles having at least two peaks in the particle size distribution is formed on a film, It is an object of the present invention to provide a polyester composition capable of obtaining a film excellent in slipperiness, abrasion resistance and scratch resistance.

[0008]

The above-mentioned object of the present invention is to contain internal precipitation type particles, have an average particle size of 0.5 to 10.0 μm by a laser diffraction scattering method, and obtain a particle size distribution. It can be achieved by a polyester composition characterized by having at least two or more peaks.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Internal precipitation-type particles in a polyester composition are internal precipitation-type particles obtained by precipitating a part or all of a catalyst, a coloring preventing agent, etc. used in the production of polyester in a reaction process. And has a peak due to the benzene ring when the internally precipitated particles are separated from the polymer by a predetermined method.

The separation of the internally precipitated particles from the polymer can be confirmed by the following method. That is, 300 g of polyester composition or film, or thread is collected and thoroughly washed with methanol to remove surface deposits.
Then, it is washed with water and dried. 2.7 kg of o-chlorophenol was added to this, and the temperature was raised to 100 ° C. with stirring,
After the temperature is raised, it is left as it is for 1 hour to dissolve the polyester part. However, when the polyester portion is not dissolved, such as when the polyester is highly crystallized, the above melting operation is performed after melting once and quenching.

Next, in order to remove coarse insoluble matters other than the internal particles, such as dust contained in the polyester or a reinforcing agent added, the solution is filtered with a G-1 glass filter.

A separation ultracentrifuge 40P type rotor RP30 manufactured by Hitachi Ltd. is equipped, and after injecting 30 ml of the solution after filtering the glass filter per cell, the rotor is rotated at 4500 rpm, and there is no abnormal rotation. After confirming that, the inside of the rotor is evacuated, the rotation speed is increased to 30,000 rpm, and the particles are centrifuged at this rotation speed. The completion of the separation is completed after about 40 minutes, but this confirmation is performed if necessary by the light transmittance at 375 mμ of the liquid after the separation being a constant value higher than that before the separation. After separation, the supernatant is removed by a gradient method to obtain separated particles.

Since the separated particles may contain a polyester component due to insufficient separation, o-chlorophenol at room temperature is added to the collected particles and suspended almost uniformly, and then the ultracentrifuge is again used. Perform processing. This operation needs to be repeated until the melting peak corresponding to the polymer cannot be detected by scanning differential calorimetric analysis of the particles.
The separated particles thus obtained are obtained by vacuum drying at 120 ° C. for 16 hours.

Whether or not the separated particles obtained by the above operation are internal precipitation type particles is determined by Fourier transform infrared spectrophotometer (manufactured by Nippon Bio-Rad Laboratories Co., Ltd .: FTS).
-40) or a UV absorption spectrophotometer (U3200 type manufactured by Hitachi Keisoku Service Co., Ltd.) is used to judge by the presence or absence of a peak due to the benzene ring.

The polyester in the present invention may be any one as long as it can form threads and films, for example, polyethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate. Rate, polyethylene-1,2-bis (2
Preferred examples thereof include -chlorophenoxy) ethane-4,4'-dicarboxylate, and polyethylene terephthalate or polyethylene-2,6-naphthalene dicarboxylate are particularly preferred.

These polyesters include dicarboxylic acids such as adipic acid, isophthalic acid, sebacic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid and their ester-forming derivatives, polyethylene glycol and hexamethylene glycol as copolymerization components. A dioxy compound such as neopentyl glycol or polypropylene glycol, an oxycarboxylic acid such as p- (β-oxyethoxy) benzoic acid, or an ester-forming derivative thereof may be copolymerized.

For example, in the case of polyethylene terephthalate, the polyester according to the present invention is obtained by transesterifying dimethyl terephthalate with ethylene glycol to give bis-
Hydroxyethyl terephthalate, then 2
A method of completing polycondensation while removing ethylene glycol under a high vacuum of 80 to 300 ° C. and 1 mmHg, or a method of directly converting terephthalic acid and ethylene glycol into bis-hydroxyethyl terephthalate by esterification instead of the transesterification method. Can be synthesized by a method of completing the polycondensation.

The added metal compounds include chlorides, bromides, acetates, butyrates, propionates, oxalates of alkali metals such as lithium, sodium and potassium, alkaline earth metals such as calcium, strontium and barium. The compound soluble in the reaction system is preferable, and after the esterification reaction or transesterification reaction is completed, the molar ratio of the glycol component and the aromatic dicarboxylic acid component is 2.4 to
It is added at a time of 1.05 and a temperature of 200 to 260 ° C.

Particularly preferred metal compounds include lithium acetate, calcium acetate, strontium acetate and the like, among which lithium compounds such as lithium acetate and lithium chloride are preferred.

As a method of obtaining the internal precipitation type particles having two or more peaks, which is a feature of the present invention, for example, an alkali metal compound or an alkaline earth metal compound is added after the transesterification reaction or the esterification reaction is completed. Then
After total reflux for 5 to 20 minutes, the phosphorus compound is added immediately. After that, excess ethylene glycol is added at normal pressure to 5
The extraction operation is carried out for about 100 minutes to 100 minutes, and then the polycondensation reaction is completed to obtain a polyester composition containing internally precipitated particles having two or more peaks. In this case, the difference from the conventional production method is that after adding the alkali metal compound, the alkaline earth metal compound, and the phosphorus compound, which are the particle source of the internal precipitation type particles, in the order described above, excess ethylene glycol is added under normal pressure. It is to carry out the extracting operation.
This results in internal particle precipitation type particles having two or more peaks, that is, the internal precipitation type particle generation rate is different due to ethylene glycol extraction under normal pressure conditions and ethylene glycol extraction operation under vacuum conditions. It is considered that two or more peaks are expressed in the shaped particles.

The amount of the metal compound added affects the amount of the internally precipitated particles, but if it is too small, sufficient slipperiness cannot be imparted. On the other hand, when the amount is too large, the added metal compound is essentially deposited with the structure before being added, and is dropped due to lack of affinity with the polymer, and particles are coarsened. May occur. The amount of the metal compound added is 0.05 to 3.0 mol%
(To the total dicarboxylic acid component) is preferable, and 0.4 to 1.5 mol% is more preferable.

As the phosphorus compound, phosphoric acid, phosphorous acid,
One or more selected from phosphonic acids and their esters can be used.

Specific examples thereof include phosphoric acid, phosphorous acid, methylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, and their methyl esters, ethyl esters, phenyl esters, and partial ester compounds. The addition amount of these phosphorus compounds is 0.05
˜1.5 mol% (relative to dicarboxylic acid component) is preferred, and more preferably 0.15 to 1.2 mol%.

The polyester composition can also be employed by blending a polymer having two or more kinds of internally precipitated particles. In addition, external particles may be included in the polyester composition.

The polyester composition of the present invention can be formed into a film by the following method, for example. Pellets of the polyester composition obtained by the polymerization reaction are sufficiently dried and then directly fed to the extruder. The pellets are melted at 260 to 350 ° C., extruded in a sheet form from a die, cooled on a casting roll and solidified to obtain an unstretched film. Next, it is preferable to biaxially stretch this unstretched film. As the stretching method, a sequential biaxial stretching method,
A simultaneous biaxial stretching method or a method of stretching the biaxially stretched film again in this manner may be adopted. Although depending on the composition of the polyester, in order to obtain a sufficient elastic modulus as a film for a magnetic recording medium, it is preferable that the final stretched area ratio (longitudinal ratio × lateral ratio) is 6 or more. Also,
To keep the heat shrinkage rate of the film small, 150 to 2
It is preferable to perform heat treatment for about 0.1 to 60 seconds in the temperature range of 60 ° C.

The use of the polyester composition in the present invention is not limited, such as general molded products and fibers, but it is particularly preferable to use it for film.

The average particle size of the internal precipitation type particles in the present invention is required to be 0.5 to 10.0 μm, preferably 0.5 to 5.0 μm. Average particle size is 10.0μ
If it is larger than m, the surface roughness of the film becomes large, and the electrical characteristics of the magnetic tape deteriorate. On the contrary, when it is smaller than 0.5 μm, the slipperiness, which is one of the objects of the present invention, becomes insufficient.

The polyester composition of the present invention must have two or more peaks in the particle size distribution. Due to the presence of two or more peaks in the particle size distribution, the film surface formed by the smaller peak particles and the larger peak particles is mixed with protrusions consisting of large and small particles, and is based on the larger peak particles. By increasing the roughness of the film surface by the projections and lowering the friction coefficient of the surface, scratch resistance is improved and resistance when contacting other surfaces such as rolls during processing etc. is reduced, and the film surface is The purpose is to make it hard to be scraped off. When the particle size distribution has a single peak, the unevenness of the film surface is small and the friction coefficient of the surface is increased, so that the running property, abrasion resistance and scratch resistance are deteriorated.

[0029]

The present invention will be described in more detail with reference to the following examples. The parts in the examples are parts by weight, and the method of measuring characteristic values and the method of evaluating effects are as follows. (A) Particle characteristics (1) Average particle size 1.0 g of polyester is mixed with phenol / ethane tetrachloride (6
Dissolve in 20 ml of mixed solvent (4/4 weight ratio) (dissolution condition: 1
30 ° C., 30 minutes; stirring), using a laser diffraction / scattering particle size distribution analyzer LA-700 manufactured by Horiba Ltd.,
The average particle size (median size) is measured and the particle size distribution is output.
The details of measurement conditions and display conditions are shown below.

[Measurement conditions] Measurement mode: Batch type cell measurement Number of times of data acquisition: 10 Distribution form: 1 Refractive index set value: 1.1 [Display condition] Cumulative distribution graph: Attached Cumulative distribution display type: Sifted histogram Scale: Fixed Fixed scale: 15 Number of divisions: 64 Particle size standard: Volume Particle size interval: Fixed interval% particle size setting: No

(B) Film characteristics (1) Friction coefficient The friction coefficient was measured according to the ASTM D-1894B method using a slip tester. The coefficient of static friction was used to determine slipperiness.

(2) Abrasion resistance A tape-shaped roll in which a film is slit into a narrow width is rubbed against a stainless steel SUS-304 guide roll at a constant tension for a long time at a high speed, and depending on the amount of white powder generated on the guide roll surface, Ranked like.

Class A: No white powder generated B class: Small amount of white powder C Class: Moderate amount of white powder D Class: Large amount of white powder generated

(3) Scratch resistance A tape running tester TBT300D / H type (manufactured by Yokohama System Laboratory Co., Ltd.) was used to slit into a tape having a film width of 1/2 inch, a tension of 30 g and a running speed of 25.
At 0 m / min, the tape was run for 60 m at a winding angle of 60 ° on a tape guide pin (stainless steel guide pin having a surface roughness of about 2500 nm in surface roughness Rt) of a video cassette,
The amount of scratches formed at that time was visually evaluated according to the following criteria.

No scratches: 5 points Shallow scratches: 3 points Deep scratches: 1 point In addition, the middle of 5 points and 3 points is 4 points, and the middle point of 3 points and 1 points is 2 points
It was a point. At this time, 3 points or less were defined as poor scratch resistance. A film having less than 3 points as judged at this time has a significantly deteriorated product quality because the film surface is worn and deep scratches are generated at the time of processing the film or traveling as a product.

Example 1 100 parts of dimethyl terephthalate, ethylene glycol 6
The transesterification reaction was carried out from 4 parts by a conventional method using 0.09 part of calcium acetate as a catalyst. The product (molar ratio of ethylene glycol component / terephthalic acid component 1.90)
In addition, 0.03 part of antimony trioxide, 0.2 of lithium acetate
After adding 5 parts at 225 ° C., about 3 minutes later, 0.16 parts of trimethyl phosphate was added. Then, after extracting excess ethylene glycol under normal pressure for 20 minutes, the pressure inside the system was gradually reduced, and finally a polycondensation reaction was performed at 0.6 mmHg and 290 ° C. for about 3 hours. The obtained polymer had an average particle size of 3.0 μm and two peaks appeared in the particle size distribution.

Next, the obtained polymer was extruded into a sheet at 288 ° C. from an extruder and rapidly cooled to obtain an amorphous sheet, which was stretched at 90 ° C. in the longitudinal direction by 3.3 times and in the transverse direction by 3.5 times. Then, the film was heat treated at 210 ° C. to obtain a film having a thickness of 12 μm. As for the film characteristics, as shown in Table 1, the coefficient of static friction was 0.52, and a film excellent in abrasion resistance and scratch resistance could be obtained.

Example 2 Two kinds of internally precipitated particle polymers (average particle diameter 0.8 μm and average particle diameter 3.9 μ) having a single peak in particle size distribution.
m) was blended, and this polymer was molded into a film by the method shown in Example 1. The film characteristics thus obtained were such that the coefficient of static friction was as good as 0.48, and the film was excellent in abrasion resistance and scratch resistance.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that excess ethylene glycol was not extracted under normal pressure. The average particle size of the obtained polymer was 2.9 μm,
Only one peak appeared in the particle size distribution. The polymer was formed into a film in the same manner as in Example 1,
The coefficient of static friction was 1.23, which was poor in slipperiness, and was extremely poor in wear resistance and scratch resistance.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 1 except that the amount of lithium acetate was increased from 0.24 part to 1.70 part. The average particle size of the obtained polymer was coarsened to 13.4 μm, but two peaks appeared in the particle size distribution. Example 1 of the polymer
As a result of making a film by the same method as above, the static friction coefficient was as good as 0.40, but coarse particles were found to have fallen off, resulting in extremely poor wear resistance and scratch resistance.

Comparative Example 3 As in Comparative Example 1, excessive ethylene glycol was not extracted under normal pressure, and the pressure reduction rate in the system was rapidly increased to carry out the polycondensation reaction in about 2 hours and 30 minutes. . Other than that, the polymerization was carried out in exactly the same manner as in Example 1. The average particle size of the obtained polymer was 0.3 μm, and the particle size distribution had only one peak. The polymer was formed into a film by the same method as in Example 1. As a result, the coefficient of static friction was increased to 1.95, slipperiness was extremely poor, and abrasion resistance and scratch resistance were poor. Comparative Example 4 A polymer obtained by blending internally precipitated particles having an average particle size of 3.5 μm and a single peak in particle size distribution with alumina-based external particles having an average particle size of 0.7 μm was prepared in the same manner as in Example 1. As a result, the coefficient of static friction was as good as 0.50, but the results were inferior in wear resistance and scratch resistance.

Comparative Example 5 An alumina-based external particle polymer having an average particle size of 0.7 μm and a silica-based external particle polymer having an average particle size of 1.8 μm (both of which have a single peak in particle size distribution) were blended, and Example 1 was used. As a result of making a film by the same method, the coefficient of static friction is 0.63.
The result was poor wear resistance and scratch resistance.

[0043]

[Table 1]

[0044]

As described above, according to the present invention,
The film containing the internally precipitated particles having at least two peaks in the particle size distribution has a good affinity with the base material and achieves a strong bond with the base material. It is possible to obtain a film having excellent abrasion resistance and scratch resistance. Further, basically, the film surface can be easily and inexpensively formed without containing external particles, so that the cost of the product can be reduced.

Claims (2)

[Claims] 1. An internal deposition type particle is contained, the average particle size by a laser diffraction scattering method is 0.5 to 10.0 μm, and the particle size distribution has at least two or more peaks. Polyester composition. 2. A film comprising the polyester composition according to claim 1.