JPH0725998B2 - Polyester composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester composition having excellent slipperiness. More specifically, it relates to a polyester composition containing a specific organic lubricant and having improved slipperiness while maintaining flatness.

[Prior Art] Polyester, especially polyethylene terephthalate, has excellent mechanical and chemical properties, and is therefore widely used as a fiber for clothing, industrial use, as well as a film for magnetic tape, photography, capacitors, etc. ing.

In these applications, not only the flatness of the surface but also the workability at the time of molding a molded product such as a film or a fiber, and the handleability of the product are required to be easily slippery.

Conventionally, as a method of improving slipperiness, silicon oxide,
A method of adding inert particles such as titanium dioxide, calcium carbonate, talc, and clay (external particles), a catalyst component used in polyester synthesis, and a method of forming fine particles based on a coloring inhibitor (internal particle method) have been proposed. It is known that fine particles in polyester are used to form protrusions on the surface to improve slipperiness. However, when such particles are used, the problem of impairing the surface flatness due to the inclusion of coarse particles or agglomerated particles is unavoidable, and there is a limit to imparting slipperiness while maintaining the surface flatness. It was

In addition, as an additive other than particles, A. An ester product of a polyol having 3 or more hydroxyl groups and an aliphatic monocarboxylic acid having 8 or more carbon atoms (JP-A-57-195143)
Alternatively, a method of using B. higher aliphatic monocarboxylic acid having 10 to 33 carbon atoms or its ester (JP-A-60-71659) is proposed. Although slip properties are improved by these compounds, when used as a magnetic recording medium for a magnetic tape or the like, higher surface flatness and slip properties are required for higher density and higher recording. That is, in the case of the compound of A, the heat resistance is insufficient, so that a foreign substance is generated when dispersed in the polyester, which becomes a defect on the film, and in the case of the compound of B, it is not compatible with the polyester, There was a problem that crater-like irregularities were generated on the surface of the polyester.

[Problems to be Solved by the Invention] As a result of intensive studies, the inventors of the present invention have found that the inclusion of a specific organic lubricant in a polyester can solve the above-mentioned drawbacks of the prior art and have reached the present invention. It was done.

That is, an object of the present invention is to provide a polyester composition having improved slipperiness while maintaining surface flatness.

[Means for Solving Problems] The object of the present invention is to provide 100 parts by weight of polyester whose main repeating unit is ethylene terephthalate,
An aliphatic hydroxy acid ester composed of an aliphatic hydroxy acid component having at least one hydroxyl group and having 10 or more carbon atoms and an aliphatic alcohol component having 15 or more carbon atoms.
This can be achieved with a polyester composition containing 0.005 to 2.0 parts by weight.

The polyester in the present invention is mainly composed of polyethylene terephthalate that can be molded into a fiber, film or other molded product. This polyester may be a homopolyester or a copolyester. Examples of acid components other than terephthalic acid include isophthalic acid and p-
β-oxyethoxybenzoic acid, diphenylsulfone-4,
One or more of 4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, 5-sodium sulfoisophthalic acid and the like can be used in combination.

As a glycol component other than ethylene glycol, propylene glycol, trimethylene triglycol, neopentyl glycol, hexamethylene glycol, pentamethylene glycol, 1,4-cyclohexanediol, 1,4
-One or two of cyclohexanedimethanol, diethylene glycol, polyoxyethylene glycol, etc.
One or more species can be used in combination.

A conventionally known method is adopted as a method for producing a polyester. When the dicarboxylic acid component is an acid component, after the esterification reaction with glycol, and in the case of a dicarboxylic acid ester, after the transesterification reaction, the obtained prepolymer is heated at high temperature.
Polycondensed polyester under vacuum. The obtained prepolymer itself can be used as a starting material for polycondensation.

The aliphatic hydroxy acid ester contained in the polyester composition of the present invention comprises an aliphatic hydroxy acid component having at least one hydroxyl group and having 10 or more carbon atoms and an aliphatic alcohol component having 15 or more carbon atoms. Must be configured. The more preferred aliphatic hydroxy acid component has 14 to 34 carbon atoms. When the aliphatic hydroxy acid component has less than 10 carbon atoms, the slipperiness improving effect cannot be obtained even if the aliphatic alcohol component has 15 or more carbon atoms, which is not preferable. Further, the number of hydroxyl groups needs to be 1 or more, preferably 1 or 2, and the position thereof is more preferably 3 or more position ( ^-3 C- ² C-COOH) with respect to the carboxyl group. The carbon number of the aliphatic alcohol component is 15
It is necessary to be above, preferably 18 to 40, more preferably 22 to 34. If it is less than 15, the desired effect of improving slipperiness cannot be obtained, which is not preferable. The total number of carbon atoms in the aliphatic hydroxy acid ester is 30 to 70.
The degree is more preferable. Specific compounds include octadecyl 3-hydroxydecanoate, octadecyl 3-hydroxytetradecanoate, octadecyl 3-hydroxyhexadecanoate, octadecyl 3-hydroxyoctadecanoate, octadecyl 3-hydroxyeicosanoate, octadecyl 3-hydroxydocosanoate, Octadecyl 3-hydroxytetracosanoate, octadecyl 6-hydroxyoctadecanoate, octadecyl 7-hydroxyoctadecanoate, octadecyl 8-hydroxyoctadecanoate,
Octadecyl 9-hydroxyoctadecanoate, octadecyl 10-hydroxyoctadecanoate, octadecyl 11-hydroxyoctadecanoate, octadecyl 12-hydroxyoctadecanoate, octadecyl 13-hydroxyoctadecanoate, octadecyl 14-hydroxyoctadecanoate, octadecyl 15-hydroxyoctadecanoate,- Octadecyl hydroxyoctadecanoate, octadecyl 17-hydroxyoctadecanoate, octadecyl 18-hydroxyoctadecanoate, eicosyl 12-hydroxyoctadecanoate, docosyl 12-hydroxyoctadecanoate, 12
-Tetracosyl hydroxyoctadecanoate, hexacosyl 12-hydroxyoctadecanoate, triacontyl 12-hydroxyoctadecanoate, dotriacontyl 12-hydroxyoctadecanoate, tetratriacontyl 12-hydroxyoctadecanoate, octadecyl 3,11-dihydroxytetradecanoate 9,10- Examples thereof include octadecyl dioxyoctadecanoate, but are not limited thereto. Further, these compounds may be present alone in the polyester, or may be present as a mixture of two or more kinds.

In the polyester composition of the present invention, the content of the hydroxy acid ester is 100 parts by weight of the polyester.
It should be 0.005-2.0 parts by weight, preferably 0.01-
1.0 parts by weight. If the content is less than 0.005 parts by weight, the effect of improving slipperiness is insufficient, and if it is used in an amount of more than 2.0 parts by weight, no further improvement effect is observed and the dispersion becomes poor, which is not preferable.

The aliphatic hydroxy acid ester can be added to the polyester at any time. That is, a method of adding during the polycondensation reaction, a method of mixing in a molten state after the completion of the polycondensation reaction, and a method of kneading with an extruder before extrusion can be used, but in order to improve the dispersion and simplify the operation. It is preferable to mix them in a molten state after the completion of the polycondensation reaction. It is also possible to use a method in which a high-concentration master polymer is prepared in advance and this is diluted with a polyester homopolymer.

In the polyester composition of the present invention, the effect can be sufficiently obtained by using the aliphatic hydroxy acid ester alone, but the above-mentioned outer particles and inner particles can be made to coexist. With the conventional method of imparting fine particles, it was not possible to satisfy the flatness and slipperiness of the film or fiber surface at the same time.
The effect can be synergistically enhanced by using the present invention together with the conventional method for imparting fine particles. Examples of the fine particles used include external particles of silica, alumina, kaolin, calcium carbonate, talc, calcium fluoride, titanium oxide, barium sulfate, calcium phosphate, etc., catalyst components used during polyester synthesis, and internal particles based on a coloring inhibitor. And so on. The average particle size of the fine particles used in combination is preferably 0.01 to 3.0 μm, and the content in the polyester composition is preferably 0.005 to 1.0 part by weight with respect to 100 parts by weight of the polyester.

Known additives such as an antistatic agent, a heat stabilizer, and an ultraviolet absorber may be added to the polyester composition of the present invention in an amount that does not impair the effects of the present invention.

[Examples] The present invention will be described in more detail with reference to Examples. In addition, it measured like the physical property in an Example.

A. Polymer intrinsic viscosity It is a value measured at 25 ° C using o-chlorophenol as a solvent.

B. Film friction coefficient It is a value measured according to the ASTM-D-1894-63 method.

C. Surface Roughness of Film The maximum roughness and the average roughness (μ) were determined by measuring with a stylus type roughness meter according to the method specified in JIS-BO601.

Example 1 100 parts by weight of dimethyl terephthalate and ethylene glycol 7
0 parts by weight calcium acetate 0.1 parts by weight, antimony trioxide
0.03 parts by weight was added, and the transesterification reaction was carried out by a conventional method.After 0.04 parts by weight of phosphoric acid trimethyl ester was added to the obtained product, the temperature was gradually raised and the pressure was reduced to 290 ° C. under a reduced pressure of 1 mmHg or less. Polymerization was carried out. A polycondensation reaction was performed for 3 hours and 15 minutes from the start of reduced pressure, and after the reaction was completed, 2 parts by weight of 12-hydroxyoctadecanoic acid triacontyl was added and kneaded under reduced pressure for about 10 minutes to obtain a polymer having an intrinsic viscosity of 0.612. (Polymer A) A polymer having an intrinsic viscosity of 0.610 was obtained in the same manner as in Example 1 except that triacontyl 12-hydroxyoctadecanoate was not added. (Polymer B) Polymer A and polymer B thus obtained were mixed in the proportions shown in Table 1, dried under reduced pressure (170 ° C., 4 hours) and melt extruded at 285 ° C. to prepare an unstretched sheet. did. Then stretched by 3.3 times in the longitudinal direction and 3.5 times in the width direction,
Heat treatment was carried out at 215 ° C. while slightly relaxing to obtain a biaxially stretched film having a thickness of 15 μm.

The surface roughness and slipperiness of the film are as shown in Table 1, and it is understood that the polyester composition of the present invention has excellent performances in surface flatness and slipperiness.

Comparative Example 1 Polycondensation and kneading were carried out in the same manner as in Polymer A of Example 1 except that sorbitan tristearate was added instead of octadecyl 12-hydroxyoctadecanoate,
A polymer with an intrinsic viscosity of 0.618 was obtained. (Polymer C) The polymer C and the polymer B of Example 1 were blended, and a biaxially stretched film was prepared in the same manner as in Example 1 such that the proportions shown in Table 1 were obtained.

Table 1 shows the surface roughness and the slipperiness of the film. Coarse protrusions due to dark brown foreign matter were present on the film surface.

In general, the desired values in the field of high-performance films for high-grade magnetic tapes are an average surface roughness of 0.015 μm or less and a static friction coefficient of 1.0 or less.

Comparative Example 2 Polycondensation and kneading were carried out in the same manner as in Polymer A of Example 1 except that triacontyl behenate was added instead of octadecyl 12-hydroxyoctadecanoate to give an intrinsic viscosity of 0.61.
Got 5 polymers. (Polymer D) The polymer D and the polymer B of Example 1 were blended to prepare a biaxially stretched film in the same manner as in Example 1.

The surface roughness and slipperiness of the film are as shown in Table 1, and crater-like unevenness was present on the surface of the film.

Example 2 100 parts by weight of dimethyl terephthalate and ethylene glycol 7
0 parts by weight calcium acetate 0.1 parts by weight, antimony trioxide
Add 0.03 part by weight and carry out a transesterification reaction by a conventional method.Add 1.0 part by weight of calcium carbonate having an average particle size of 0.4μ as ethylene glycol slurry to the obtained product and carry out a polycondensation reaction according to a conventional method. , Intrinsic viscosity 0.619
Got the polymer of. (Polymer E) The polymer E was blended with the polymers A and B of Example 1 to prepare a biaxially stretched film in the same manner as in Example 1. As for the characteristics of the film, as shown in Table-1, it can be seen that the surface flatness and slipperiness are good.

Comparative Example 3 The polymer B of Example 1 and the polymer E of Example 2 were blended to prepare a biaxially stretched film containing no particles and no organic lubricant in the same manner as in Example 1. The film had poor slipperiness and the friction coefficient could not be measured.

Comparative Example 4 Polymer D of Comparative Example 2, polymer B of Example 1 and polymer E of Example 2 were blended to prepare a biaxially stretched film in the same manner as in Example 1.

As shown in Table 1, it is understood that the characteristics of the film are inferior to those of the present invention in surface flatness and slipperiness.

Example 3 Example 1 was repeated except that octadecyl 3-hydroxyoctadecanoate, octadecyl 3-hydroxydodecanoate, and triacontyl 14-hydroxytetradecanoate were added instead of triacyl 12-hydroxyoctadecanoate.
Polycondensation and kneading were carried out in the same manner as in Polymer A to obtain a polymer. (Polymer F, G, H) The polymer F, G, H was blended with the polymer B of Example 1 and the polymer E of Example 2 to obtain a biaxially stretched film in the same manner as in Example 1.

As shown in Table 1, the characteristics of the film are excellent in surface flatness and slipperiness.

Comparative Example 5 Polycondensation and kneading were carried out in the same manner as in Polymer A of Example 1 except that dodecyl 8-hydroxyoctanoate and dodecyl 12-hydroxyoctanoate were added instead of triacontyl 12-hydroxyoctadecanoate. Got
(Polymer J, K) The polymer J, K, the polymer B of Example 1 and the polymer E of Example 2 were blended to prepare a biaxially stretched film in the same manner as in Example 1.

The characteristics of the film are as shown in Table 1 and it is understood that the slipperiness is insufficient.

[Effects of the Invention] In the present invention, the flatness and the slipperiness of the surface can be satisfied at the same time by including a specific organic lubricant in the polyester.

Since the polyester composition of the present invention has excellent surface flatness and slipperiness, it is effectively used in the field of films, fibers and the like. When used in the film field, the effect is more remarkably exhibited.

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Claims (1)

[Claims] 1. An aliphatic hydroxy acid component having at least one hydroxyl group, having 10 or more carbon atoms, and having 15 or more carbon atoms, per 100 parts by weight of a polyester whose main repeating unit is ethylene terephthalate. 0.005 of aliphatic hydroxy acid ester composed of aliphatic alcohol component
A polyester composition containing about 2.0 parts by weight.