JP2560763B2 - Polyester composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester composition.

[Prior Art] Polyesters, especially polyethylene terephthalate, are widely used as fibers, films, and other molded articles because of their excellent physical and chemical properties. However, contrary to its excellent characteristics, unfavorable troubles such as deterioration of workability due to poor processability in the molding step for obtaining the above-mentioned molded product or slipperiness in handling of the product itself, reduction of commercialization value occur. It is also known to do.

To solve these problems, a number of methods have been proposed to improve the slipperiness of the surface of the molded article by adding appropriate irregularities to the surface of the molded article by incorporating fine particles in the polyester, and some of them have been put to practical use. ing. For example, there is a method of adding inert inorganic particles such as silicon oxide, titanium dioxide, calcium carbonate, talc and kaolinite to the polyester synthesis reaction system. (For example, JP-A-55-133431).

However, when such an inert inorganic particle is added, the transparency, which is an important characteristic of the polyester, decreases as the amount added increases. It is known that when formed into a film, transparency is remarkably impaired, particularly due to the influence of the refractive index of the particles and polyester and the generation of voids around the particles due to stretching. Regarding the refractive index of the particles, there are few particles having a refractive index close to that of polyester, especially polyethylene terephthalate, and even if there are particles having a similar refractive index, there is a problem that the slipperiness is poor.

Regarding voids, the particles have insufficient affinity with polyester, so that voids are generated, which causes the transparency to be significantly impaired.

In recent years, especially for plate making printing, which requires a film with excellent slipperiness and transparency, for X-ray photography, for microfilm, for electrophotography, for copying applications such as for diazo photography,
It has become required to satisfy the trade-off between smoothness and transparency to a higher degree. However, the current situation is that the decision has not been reached yet.

Therefore, the present inventor has improved the drawbacks of the above-mentioned conventionally used inert inorganic particle addition method, and as a result of earnest studies to obtain a polyester film having an excellent balance of slipperiness and transparency, as a result of silica, It is possible to achieve the object of the present invention by using an inorganic oxide having a specific porosity and an average particle diameter as a main constituent component of a composite oxide in which a silicon atom and a metal oxide are bonded via oxygen. There was found.

[Problems to be Solved by the Invention] An object of the present invention is to use, as a main constituent, a composite oxide in which a silicon atom of silica and a metal oxide are bonded with oxygen as an intermediary, and have a specific porosity and an average value. It is intended to provide a polyester composition containing an inorganic oxide having a particle size and having excellent slipperiness and transparency which cannot be achieved by conventional techniques.

[Means for Solving Problems] The above-mentioned object of the present invention is to have a porosity of 50 to 95%, an average particle diameter of 0.01 to 5 μm, and a silicon atom of silica and a metal oxide containing oxygen. This is achieved by a polyester composition containing an inorganic oxide whose main constituent is a complex oxide bonded via an intermediary.

The difunctional acid component of the polyester of the present invention is mainly an aromatic dicarboxylic acid or an ester-forming derivative thereof, specifically, terephthalic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis. (2-o-chlorophenoxy) ethane-4,4'-dicarboxylic acid, dimethyl terephthalate as its ester-forming derivative, 2,6-naphthalene dicarboxylic acid, 1,2-bis (2-o-chlorophenoxy) ethane- Examples thereof include dimethyl 4,4′-dicarboxylate, and among them, terephthalic acid or dimethyl terephthalate is preferable. Examples of the glycol component include ethylene glycol, butylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, and 1,4-cyclohexanedimethanol. Of these, ethylene glycol is preferable. In addition to these dicarboxylic acid or its ester-forming derivative and glycol component, other components may be copolymerized, for example, diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, p-xylene glycol, 1,4- Cyclohexanedimethanol, 5-diol components such as sodium sulforesorcin, adipic acid, sebacic acid, phthalic acid, 5-
Examples include dicarboxylic acid components such as sodium sulfoisophthalic acid, dicarboxylic acid components such as 5-sodium sulfoisophthalic acid, polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxydicarboxylic acid components such as oxyethoxybenzoic acid. To be

When the dicarboxylic acid component is a dicarboxylic acid, it is subjected to an esterification reaction with glycol, and when the dicarboxylic acid ester is a dicarboxylic acid ester, after a transesterification reaction with glycol, polycondensation is performed at high temperature and reduced pressure to obtain a polyester.

It is also possible to carry out polycondensation using the prepolymer itself as a starting material.

In the inorganic oxide used in the present invention, a silicon atom of silica and a metal oxide are bonded via oxygen, and mainly silica and one or more kinds of metal oxides are constituent components.
The feature of the present particles is that the refractive index can be changed by the constituent components of silica and metal oxide. That is, the refractive index can be set close to the refractive index of polyester by selecting the constituent components, and when formed into a film, a very transparent film can be obtained. Therefore,
The type of metal oxide that can be bonded to silica is not particularly limited, but a metal oxide having a higher refractive index than silica is preferable,
Examples thereof include titanium oxide, zirconium oxide, germanium oxide, tin oxide, aluminum oxide and magnesium oxide. Among them, titanium oxide and zirconium oxide are particularly preferable from the viewpoint of transparency of the film. Of course, an alkali metal oxide may be included as the metal oxide. The range of refractive index is 1.
50 to 1.70 are more preferable.

The inorganic oxide has a porosity of 50 to 95%, preferably 55 to 80%. When the porosity is less than 50%, the film is better in transparency than the above-mentioned inorganic particles, but when the porosity is 50% or more, the affinity with polyester is improved and the transparency is remarkably improved. If it exceeds 95%, it becomes difficult to maintain the particle shape.

On the other hand, the shape of the particles is preferably spherical from the viewpoint of slipperiness, preferably having a volume shape factor of 0.25 to 0.52, and more preferably 0.35 or more.

[However, the volume shape factor f is represented by the following equation. f = V /
D ³ V is the particle volume (μm ³ ), D is the maximum diameter (μm) on the projection surface of the particle] The method for producing the inorganic oxide used in the present invention is to use an organosilicon compound (alkoxysilane or its low-condensation compound). An organometallic compound (for example, tetrabutyl titanate in the case of Ti) is mixed in advance to prepare a mixed solution. After that, the adjustment liquid is added to an alkaline solvent that dissolves in the organic silicon compound and the organic folklore, but does not substantially dissolve in the reaction product, and the inorganic oxide containing silica and the metal oxide as main constituents is added. The primary particles of the product are precipitated.
After that, a method of dispersing the primary particles in water to form colloidal particles and drying the sol to form a gel having a specific porosity is preferably used, but this method is not particularly limited. Absent. In the inorganic oxide obtained by such a method, it is possible to confirm that both components are chemically bound, usually by measuring the infrared spectrum and refractive index of the inorganic oxide. For example, in the infrared spectrum, when the metal oxide is TiO ₂ , a peculiar absorption can be observed at 950 cm ^-1 , and the refractive index of the inorganic oxide is between the respective refractive indexes of its constituents, and the metal oxide This can be confirmed from the fact that the refractive index of silica alone becomes higher as the components of the product such as TiO ₂ and ZrO ₂ increase.

The average particle size of the inorganic oxide used in the present invention is 0.1 to 5 μm.
It is necessary to set it as follows, and it is more preferably 0.05 to 2 μm. When the average particle size is less than 0.01 μm
The slipperiness decreases. On the other hand, if the average particle size exceeds 5 μm, the transparency of the film decreases due to an increase in scattering on the film surface due to the large protrusions.

Further, the addition amount of the inorganic oxide to the polyester is 0.
The amount is 01 to 10% by weight, preferably 0.02 to 2% by weight.

When the inorganic oxide used in the present invention is used, it can be designed to have a refractive index close to that of polyester depending on the composition ratio of silica and metal oxide, and since there is almost no void with good affinity with polyester, when a biaxially stretched film is used, A film having excellent transparency can be obtained, and the trade-off phenomena of slipperiness and transparency can be more highly satisfied. The timing and method of adding the inorganic oxide particles to the polyester are not particularly limited, but it is particularly preferable from the viewpoint of particle dispersibility to add the inorganic oxide particles at a stage before the initiation of polymerization and during the polycondensation reaction. It is preferable to add the particles in the precursor stage or the polycondensation stage of the polyester composition in a slurry state in which ethylene glycol is dispersed.

As a dispersion method in a dispersion medium such as ethylene glycol, for example, a high speed disperser, a sand mill, a roll seal or the like may be used.

When dispersed, phosphoric acid, phosphorous acid, phosphorus atom-containing compounds such as sodium hexamethanate, nitrogen atom-containing compounds such as tetraethylantimony hydroxide, hydroxylamide, alkali compounds, cations, anions, amphoteric or nonionic, etc. It is particularly preferable to use a dispersant such as a surfactant because the dispersibility of the inorganic oxide particles in the slurry and the polymer is further improved.

Further usually used in the production of polyester lithium, sodium, carboxylic acid, magnesium, manganese, zinc, antimony, germanium, metal oxide catalysts of compounds such as titanium, phosphorus compounds as a coloring inhibitor,
Inorganic particles other than inorganic oxide particles and organic polymer fine particles can be appropriately added as necessary.

[Examples] The present invention will be described in detail below with reference to Examples.

The characteristic values of the obtained polyester were measured according to the following methods.

(A) Particle size of particles The average particle size was measured by an electron micrograph of the particles.
It was determined by the equivalent sphere diameter of the particle corresponding to the volume% point. It is a diameter having the same volume as an equivalent sphere diameter and a particle.

(B) Refractive Index of Particles A solvent having the same refractive index as that of the inorganic oxide of the sample was prepared, and the refractive index of the solvent was used as the refractive index of the sample. As a method for adjusting the solvent, the sample was suspended in the solvent, and a solvent composition that was transparent to the naked eye was adjusted at a constant temperature. The solvent used was pentane, hexane, cyclohexane, toluene, styrene, methylene iodide, etc., and the refractive index of the solvent was measured by Abbe's refractive index.

(C) Particle composition ratio The composition ratio of the inorganic oxide used in the present invention was determined by quantifying each component by ICP (inductively coupled plasma) emission spectroscopy.

(D) Porosity (%) The pore volume of the particles is measured by a mercury porosimeter,
It is calculated from the pore volume and the specific gravity of the particles.

(E) Intrinsic viscosity of polymer It was measured at 25 ° C using o-chlorophenol as a solvent.

(F) Particle Dispersion State in Polymer After the polymer was cut into an ultrathin section of about 800 L by an ultrathin film forming apparatus, the particle dispersion state in the polymer was observed by a transmission electron microscope.

 The state of dispersion was determined as follows.

：: The secondary aggregated particles were hardly observed and the object was achieved.

(Triangle | delta): Secondary agglomerated particles exist, and the objective is not achieved.

X: The objective was not achieved because most of the particles were secondary aggregated particles.

(G) Film characteristics 1) Surface roughness: Ra (μm) Measured by stylus surface roughness (cutoff value
0.08mm, measuring length 0.5mm. However, according to JIS-B-8601. 2) Sliding property According to ASTM-1894B-63, a static friction coefficient (μs) and a dynamic friction coefficient (μd) were measured using a slip tester.

3) Film haze Measured according to ASTM-D1003-52.

4) Void Stretching ratio: 3.3 times long, 3.6 times wide, stretching temperature 85-95 ° C
A 25μ thick biaxially oriented film stretched by a liquid paraffin is mounted on a slide glass with a transmission optical microscope in the dark field, and the area A of the high brightness part (white part) is image analyzer (QTM900, Cambridge Instrument) Manufactured). Next, the area B of the low-brightness part (gray to black part) in the same place as the above-mentioned high-brightness part was obtained with an image analyzer in the same manner as above with a phase contrast microscope, and the ratio (B / A) of both areas was calculated. The void ratio was used.

 The evaluation criteria are as follows.

 Void ratio ○: The objective is achieved with less than 0.06.

Δ: The objective was not achieved with 0.06 to 0.13.

×: The value exceeds 0.13 and the purpose is not achieved.

Example 1 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were used to carry out a transesterification reaction by a conventional method using 0.09 parts by weight of calcium acetate as a catalyst, and the product was 0.03 parts by weight of ammonium trioxide and trimellimethyl phosphate.
Spherical inorganic oxide particles (SiO ₂ · TiO ₂ , composition ratio SiO ₂₎ composed of silica and titanium oxide having a porosity of 75% and an average particle size of 0.6 μm dispersed as an ethylene glycol slurry of 0.2 parts by weight and 10% by weight concentration: TiO ₂ = 80: 20, volume shape factor
0.40) 0.1 part by weight was added and polymerized by a conventional method to obtain polyethylene terephthalate having an intrinsic viscosity of 0.610 and a softening point of 260.5 ° C. As a result of observing the particles in the polymer with a transmission microscope, the particles were in a substantially monodispersed state with little secondary aggregation. The polymer was melt extruded at 290 ° C and stretched 3.3 times in the machine direction at 85 ° C and 3.6 times in the transverse direction at 95 ° C. Then, it was heat set at 205 ° C. to obtain a biaxially stretched film having a thickness of 25 μm. As a result of evaluating the film characteristics,
The slipperiness and transparency were good (Table 1).

Examples 2 to 9 and Comparative Examples 1 to 3 The types of the inorganic oxide particles contained, the ratio of the components constituting the particles, the porosity, the average particle size and the content (volume shape factor is
SiO ₂・ TiO ₂ : 0.40, SiO ₂・ ZrO ₂ : 0.41, SiO ₂・ TiO ₂・ Al ₂ O
₃ : 0.38) was changed variously to give a polyethylene terephthalate biaxially oriented film in the same manner as in Example 1. When the type of the inorganic oxide contained and the average particle size of the porosity were within the range of the present invention, when formed into a film, both slipperiness and transparency were excellent (Examples 2 to 9).

On the other hand, when the porosity and the average particle diameter of the contained inorganic oxide particles were other than those of the present invention, it was not possible to satisfy both the slidability and the transparency. (Comparative Examples 1 to 3) Comparative Examples 4 to 6 In the same manner as in Example 1, colloidal silica particles (volume shape factor 0.50) and titanium dioxide particles (volume shape factor 0.3.
5), a biaxially oriented polyethylene terephthalate film containing α-alumina particles (volume shape factor 0.22) was obtained. In either case, it was not possible to satisfy both the slip property and the transparency.

[Effects of the Invention] The polyester of the present invention contains inorganic oxide particles containing a composite oxide, in which a silicon atom of silica and a metal oxide are bonded through oxygen as a main component, as a main component. Excellent effects such as

(1) Since the inorganic oxide particles of the present invention are extremely uniformly dispersed in a polymer, they are excellent in slipperiness between fibers, films or molded articles obtained from the polyester composition of the present invention, and are excellent in extrudability and the like. Clogging of the molding machine or thread breakage,
No film tears or transparency problems.

(2) The particles of the present invention can be designed to have a refractive index close to that of polyester by selecting the composition ratio of silica and metal oxide, and voids are remarkably small. can get. Such a film is suitable for photography and plate making.

(3) Since the particles of the present invention have a good affinity with polyester and almost no voids, they are excellent in abrasion resistance and electrical insulation when formed into a film. Such a film is suitable for magnetic tape applications and capacitor applications.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display part C08K 3:36) (56) References JP-A-60-82325 (JP, A) JP-A-62 -135543 (JP, A) JP-A-62-241928 (JP, A) JP-A-62-95339 (JP, A)

Claims (1)

(57) [Claims] 1. A porosity of 50 to 95% and an average particle diameter of 0.01 to 5 μm.
A polyester composition containing m, and an inorganic oxide containing a composite oxide in which a silicon atom of silica and a metal oxide are bonded via oxygen as a main component.