JPH0493348A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. giving a molded item contg. small voids and excellent in slipperiness, shavability, and abrasion resistance by compounding a polyester with spherical inorg. particles having specified compsn., mean particle diameter, specific surface area, and microprobe vol. in the particle. CONSTITUTION:100 pts.wt. polyester is compounded with 0.005-5 pts.wt. spherical inorg. particles mainly comprising silica and/or alumina and having a mean particle diameter of 0.1-5mum, a specific surface area of 100m<2>/g or higher, and a microprobe vol. in the particle of 1.5ml/g or higher, giving the title compsn. As the polyester, one mainly comprising alkylene terephthalate units and/or alkylene naphthalate units is pref., polyethylene terephthalate and polyethylene 2, 6-naphthalate being examples.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polyester composition containing specific spherical inorganic fine particles, which improves slipperiness, abrasion resistance, abrasion resistance, transparency, etc. The present invention relates to a polyester composition capable of forming excellent molded articles.

[Prior Art] Generally, polyester, particularly polyethylene terephthalate or polyethylene naphthalate, has excellent mechanical properties and chemical properties, and is therefore widely used for films, Im fibers, etc. However, when producing films or fibers that take full advantage of their transparency and brightness, process defects often occur during the molding and processing steps. This is often due to a high coefficient of friction.

Conventionally, many methods have been proposed to reduce the coefficient of friction of polyester, including the presence of fine particles in polyester, but the affinity between the fine particles and polyester is insufficient, and the slipperiness and scraping of films and fibers have Both properties and abrasion resistance were unsatisfactory. To explain this method more specifically, as a means to improve the surface properties of polyester, conventionally, there are two methods: (1) a method in which part or all of the catalyst used during polyester synthesis is precipitated during the reaction process (internal particle precipitation method); ■ Many methods have been proposed in which fine particles of calcium carbonate, silicon oxide, etc. are added during or after polymerization (external particle addition method).

However, in the internal particle precipitation method (2), since the particles are metal salts of polyester components, it has a certain degree of affinity with polyester, but on the other hand, it is a method in which particles are generated during the reaction, so the amount of particles It is difficult to control the diameter and prevent the generation of coarse particles.

On the other hand, in method (2), if the particle size, amount added, etc. are appropriately selected, and fine particles from which coarse particles have been removed by classification or the like are added, excellent lubricity can be obtained. However, since the affinity between the inorganic fine particles and the organic component polyester is not sufficient, the fine particles and the polyester become separated at the interface during stretching, etc., and voids are generated. Therefore, there are problems to be solved in terms of abrasion resistance, wear resistance, and in some cases, transparency.

To improve the affinity between inorganic particles and polyester, surface treatment using a coupling reaction between silane compounds or titanate compounds and inorganic particles has been proposed, but the treatment process is complex and what are the expectations? There were various problems such as lack of effectiveness.

[Purpose of the Invention] In view of the above-mentioned circumstances, the present inventors conducted extensive studies in order to obtain a polyester composition suitable for forming molded products with excellent slipperiness, abrasion resistance, abrasion resistance, or transparency. As a result, the average particle size was 0.1 to 5 μm, mainly composed of silica and/or alumina, and the specific surface area was 100 rn2/
0.00 g of spherical inorganic fine particles with a particle size of 1.5 ml/g or more and a particle pore volume of 1.5 ml/g or less relative to polyester.
It has been discovered that a polyester composition containing 5 to 5% by weight has good properties, and the present invention has been achieved.

Therefore, an object of the present invention is to provide a polyester composition that can form molded articles with small voids and excellent slipperiness, abrasion resistance, and abrasion resistance.

[Configuration and Effects of the Invention] According to the present invention, the first object of the present invention is to
．． Spherical inorganic fine particles having a diameter of 1 to 5 μm, mainly composed of silica and/or alumina, and having a specific surface area of 100 m2/g or more and a particle pore volume of 1.5 ml1/g or less are added to the polyester at a rate of 0. This is achieved by a polyester composition characterized by containing 0.005 to 5% by weight.

The polyester referred to in the present invention is a polyester containing an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component.

The polyester is substantially linear and has film or fiber forming properties, particularly by melt forming. Examples of aromatic dicarboxylic acids include terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid, diphenylethanedicarboxylic acid, diphenyldicarboxylic acid, diphenyl etherdicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenylketonedicarboxylic acid, and the like. Examples of aliphatic glycols include those having 2 or more carbon atoms, such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, decamethylene glycol, etc.
10 polymethylene glycol, or alicyclic diols such as cyclohexane dimetatool.

In the present invention, polyesters containing, for example, alkylene terephthalate and/or alkylene naphthalate as main constituents are preferably used.

Among such polyesters, for example, not only polyethylene terephthalate and polyethylene-26-naphthalate, but also terephthalic acid or 2,6-naphthalenedicarboxylic acid accounts for 80 mol% or more of the total dicarboxylic acid component, and 80 mol% of the total glycolic acid component Copolymers in which mol % or more is ethylene glycol are preferred, in which case 20 mol % or less of the total acid component is terephthalic acid and/or 2,
Can be the above-mentioned aromatic dicarboxylic acids other than 6-naphthalene dicarboxylic acid, and also aliphatic dicarboxylic acids such as adipic acid, sebacic acid, etc.; cyclohexane-1
, 4-dicarboxylic acid, and the like. In addition, 20 mol% or less of the total glycol component can be the above-mentioned glycols other than ethylene glycol, or aromatic diols such as hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)propane, etc.; Aliphatic diols having an aromatic ring such as 1,4-dihydroxymethylbenzene; polyalkylene glycols (polyoxyalkylene glycols) such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. can also be used.

In addition, the polyester in the present invention may contain components derived from oxycarboxylic acids such as aromatic oxyacids such as hydroxybenzoic acid; aliphatic oxyacids such as ω-hydroxycaproic acid; dicarboxylic acid components and oxycarboxylic acid components. It also includes those copolymerized or combined in an amount of 20 mol% or less based on the total amount of.

Furthermore, the polyester in the present invention contains a trifunctional or higher functional polycarboxylic acid or a polyhydroxy compound, such as trimellitic acid, in an amount within a substantially linear range, for example, an amount of 2 mol % or less based on the total acid components. Copolymerized products such as pentaerythritol are also included.

The inorganic fine particles used in the present invention are spherical inorganic fine particles mainly composed of silica and/or alumina, and have a specific surface area of 100 m2/g or more and a particle pore volume of 1.5 ml/g or less. Particle pore volume of inorganic fine particles is 1.5 m
If it exceeds l/g, it becomes difficult for the particles themselves to maintain their shape in the polyester, which is undesirable.
If the specific surface area is less than 100 m''/g, the affinity between the inorganic fine particles and the polyester will be insufficient, resulting in poor abrasion resistance and wear resistance, which is not preferable.

The spherical fine particles preferably have a sphericity expressed by a particle diameter ratio (major axis/minor axis) of 1.2 or less; when this ratio is 1, they represent a perfect sphere.

The inorganic fine particles used in the present invention may contain an oxide component other than silica or alumina, for example, a part of the alumina (for example, less than 30% by weight) may contain SiR? It may be substituted with an oxide such as Na or oxide.

Spherical inorganic fine particles can be manufactured according to the method described in, for example, JP-A-1-230421 and JP-A-1-239015, and even if they are manufactured by a method other than this, the method described above may be used. There is no problem as long as the material has the following characteristics.

The inorganic fine particles used in the present invention have an average particle size of 0.1 to 5 μm.
, preferably 0.1 to 3 μm.

If the average particle size of the inorganic fine particles exceeds 5 μm, for example, the roughness of the film will become higher than necessary, resulting in a decrease in electromagnetic conversion characteristics and an increase in dropouts after forming into a magnetic tape, which is undesirable. The average particle size of the fine particles is 0.
If it is less than 1 μm, for example, the handling properties of the film, abrasion resistance,
This is undesirable because the running properties and abrasion resistance when used as a magnetic tape become poor.

The content of inorganic fine particles in the present invention is o, oos to 5% by weight, preferably 0.01 to 3% by weight, based on the polyester.
Weight%. If the content is less than 0.005% by weight, the effect of improving machinability and wear resistance is not observed, which is undesirable.On the other hand, if the content exceeds 5% by weight, coarse protrusions will occur due to agglomeration, for example, electromagnetic tape of magnetic tape. This is undesirable as it leads to deterioration of conversion characteristics.

Although the particle size distribution of the inorganic fine particles used in the present invention is not particularly limited, it is preferable to have a sharper particle size distribution, for example, one having a relative standard difference defined below of 0.7 or less, more preferably 0.5 or less.

Relative standard deviation = here, Di: Area circle equivalent diameter of each particle represents.

For this reason, it is preferable to remove coarse particles from the inorganic fine particles using a purification process before incorporating them into the polyester. Examples of the classification means include wet or dry centrifuges, filter filtration, and the like. Note that two or more of these methods may be used in combination to perform stepwise purification.

The surfaces of these inorganic fine particles may be modified with various surface treatment agents. These surface treatment agents, which are usually used to improve the affinity with ethylene glycol and polyester, are generally applied in an amount of 5% by weight or less based on the particles. Examples include silane coupling agents and Mention may be made of titanium coupling agents.

The inorganic fine particles in the present invention may be added to the polyester in any manner before the start of the polycondensation reaction, during the polycondensation reaction, or after the polycondensation reaction, but particularly preferably before the polycondensation reaction and at the beginning of the polycondensation reaction. . Particularly preferred is a method in which the glycol slurry is added before the end of the transesterification or esterification reaction.

Polyester molded products, such as fibers and films, can be obtained from the above polyester composition as it is, or by diluting it with another polyester (polyester that does not contain a predetermined proportion of inorganic fine particles) and then forming a film or spinning the polyester composition. . Other polyesters used for dilution include, for example, polyesters produced by conventional precipitation or addition methods or particle-free polyesters. In any case, it is necessary that the final molded product contains a predetermined amount of inorganic fine particles.

The polyester composition of the present invention can be made into molded products such as films and fibers by known methods.

In the case of a film, the film forming conditions are known methods, for example, usually 2.
A method in which the sheet is extruded for 4M at 80 to 300°C, cooled and solidified to form an amorphous sheet, and then biaxially stretched sequentially in, for example, the knitting direction and the transverse direction, or the longitudinal, transverse, and longitudinal directions.
A method of simultaneous biaxial stretching in the lateral direction, etc. can be adopted.

The polyester composition of the present invention has excellent slip properties and excellent affinity between particles and polyester, so it can be used to form molded products with advantages such as good abrasion resistance and abrasion resistance, and can be used for various purposes. . In particular, it can be preferably used in the film field and textile field, which require slipperiness, abrasion resistance, abrasion resistance, or transparency.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist thereof. The measurement methods and definitions of various physical properties and characteristics in Examples are as follows.

In addition, "parts" in the examples mean parts by weight.

(1) Particle size There are the following conditions for particle size measurement.

1) When calculating the average particle size, diameter ratio, etc. from powder 2) When calculating the average particle size 1 particle size ratio of particles in the film 1) From powder The individual particles are scattered so that they do not overlap as much as possible, and a thin gold film is deposited on the surface using a gold sputtering device to a thickness of 200 to 300 layers. TE [L, Luzex 500 made by Japan Regulator ■
The major axis (Dli), minor axis (DSi), and area circle equivalent (Di) of at least 100 particles are determined. Then, the average particle size 1 particle size ratio is calculated from these values.

2) In the case of particles in a film, a small piece of sample film was fixed on a sample stage for a scanning electron microscope, and sputtering equipment (JFC-110 manufactured by JEOL Ltd.) was used.
The ion etching process is performed on the film surface under the following conditions using a Type 0 ion etching apparatus.The 0 condition is such that the sample is placed in a Pelger, the degree of vacuum is raised to a vacuum state of approximately 10'' Torr, and the voltage is 0. 25KV, current 1
Perform ion etching at 2.5 aA for approximately 10 minutes. Furthermore, using the same equipment, a gold sputter was applied to the surface of the film, and a 10,000 to 30,000 gold sputter was applied using a scanning electronic microscope.
Observe at double magnification and use Luzex 50 manufactured by Nippon Regulator ■.
the long diameter (Dli) of at least 100 particles at 0;
Determine the short axis (Dsi) and the area circle equivalent diameter (Dl). Then, the average particle size 9 particle size ratio is calculated from these values.

(2) Affinity In the film (surface) according to the method of +1) -2) above
The periphery of the particles is exposed, the major axis of at least 50 solid particles and the major axis of the voids are measured, and the number average value of the void ratio is determined by the following formula: void ratio = major axis of void / major axis of solid fine particles.

This number average value is used to display the following criteria.

1st grade = 1≦void ratio<1.5+ (i.e., voids do not exist or are very small) 2nd grade = 1.5≦void ratio<2.0 3rd grade = 2.0≦void ratio<3.0 4th grade =3.0≦void ratio<4.0 (3) Press one blade perpendicularly against a 172-inch wide tape-shaped slit of the abrasive film, push it in 0.5 inch, and then
ci traveling (speed 6.7ci/s, tension=50
0g). The height of the powder adhesion scraped off by one blade is read with a microscope and determined as the scraping amount (μm).This scraping amount is 15 μm.
If it is less than m, the abrasion resistance is considered to be good, and if it exceeds it, the durability is considered to be poor. This corresponds to the abrasion resistance during the film processing process.

(4) Haze (cloudiness) According to JIS-674, the haze of the film is determined using an integrating sphere HTR meter manufactured by Nippon Seimitsu Kogaku Co., Ltd.

(5) Specific surface area and string hole volume Using Autosorb-1 manufactured by Quantachrome, BET
The specific surface area and pore volume are determined by the method.

Examples-1 to -3 and Comparative Examples-1 and -2 100 parts of dimethyl terephthalate and 70 parts of ethylene glycol (hereinafter abbreviated as EG) were mixed with 0.035 parts of manganese acetate tetrahydrate as a catalyst. After carrying out the transesterification reaction according to the method, 0.03 parts of trimethyl phosphate was added under stirring, and 1 part of EG slurry (silica concentration 0.2 wt% vs. polymer) was added.

Thereafter, 0.03 parts of antimony trioxide was added, followed by a polycondensation reaction under high temperature and high vacuum in a conventional manner, and the intrinsic viscosity (
Orthochlorophenol, 35℃) 0.60dl/g
of polyethylene terephthalate was obtained.

Next, the obtained polyethylene terephthalate was heated to 180
After drying at °C, it was formed into a sheet using a melt extruder, and the resulting amorphous sheet was then biaxially stretched at 90 °C with a longitudinal stretch ratio of 3.5 times and a transverse stretch ratio of 4.0 times, followed by heat setting. , and a film with a thickness of 15 μm.

The properties of this film are shown in Table 1.

In the films of Examples-1 to -3, the lubricant had high affinity for the polymer, and had good abrasion resistance and transparency. On the other hand, the films of Comparative Examples-1 and -2 were poor in both abrasion resistance and transparency.

Examples 4 and 5 A polyester was synthesized in the same manner as in Example 1, except that spherical alumina having the characteristics shown in Table 1 was used instead of spherical silica, and a film was also obtained.

The properties of this film are shown in Table 1, and both the abrasion resistance and transparency were good.

Claims (1)

[Claims] 1. Average particle size is 0.1 to 5 μm, mainly composed of silica and/or alumina, and specific surface area is 100 m^
2/g or more and a particle pore volume of 1.5 ml/g or less, 0.0
A polyester composition characterized by containing 0.05 to 5% by weight. 2. The polyester composition according to claim 1, wherein the polyester is a polyester whose main repeating unit is ethylene terephthalate or ethylene naphthalate. 3. A polyester film comprising the polyester composition according to claim 1.