JPH01240558A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain a polyester composition having excellent slipperiness and transparency and suitable for photographic use, plate-making, magnetic recording tape, etc., by compounding crosslinked polystyrene particles having specific heat-decomposition temperature and void ratio. CONSTITUTION:A polyester composed of a difunctional acid component composed mainly of an aromatic dicarboxylic acid (e.g., terephthalic acid) and one or more glycol components (e.g., ethylene glycol) is compounded with crosslinked polystyrene having a heat-decomposition temperature of >=380 deg.C, preferably >=410 deg.C, a void ratio of 40-95%, preferably 50-80% and an average particle diameter of 0.01-5mum, preferably 0.05-2mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polyester composition, and more specifically, a polyester composition having a thermal decomposition temperature of 380°C or higher, a porosity of 40 to 95%, and an average particle size of 0. The present invention relates to a polyester composition containing crosslinked polystyrene particles of 01 to 5 μm.

[Prior art] Polyester, especially polyethylene terephthalate [.
Because of its excellent physical and chemical properties, it is widely used in fibers, films, and other molded products. However, contrary to its excellent properties, undesirable problems occur, such as poor workability due to poor process passability during the molding process to obtain the above molded product, or poor slipperiness during handling of the product itself, and a decrease in product value. It is also known to do.

In order to solve these problems, many methods have been proposed to improve the slipperiness of the surface of molded products by incorporating fine particles into polyester to give the surface of molded products appropriate irregularities, and some of these methods have not been put into practical use. ing. For example, inert inorganic particles such as silicon oxide, titanium dioxide, calcium carbonate, talc, and kaolinite, or organic polymers such as benzoguanamine/formaldehyde resin, bolite/fluoroethylene-hexafluoropropylene copolymer, and polyphenyl ester resin. There is a method of adding molecular fine particles to the polyester synthesis reaction system (for example, Japanese Patent Application Laid-Open No. 133431/1983).
(Japanese Patent Application Laid-open No. 125247/1983, etc.).

However, when such particles are added, clarity, an important property of polyester, decreases as the amount added increases. When formed into a film, it is known that transparency is significantly affected by 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 with a refractive index close to that of polyester, particularly polyethylene terephthalate, and even if there are particles with a similar refractive index, there are problems such as poor slipperiness.

On the other hand, some organic polymer fine particles in particular have a refractive index close to that of polyester, but their heat resistance is generally inferior. Therefore, it tends to soften during polyester polymerization or melt molding, which causes problems such as poor dispersion of organic particles in the polymer due to aggregation. Unexamined Japanese Patent Publication No. 55-1 502
9: Even the crosslinkable polymer particles shown in the publication 1711 have insufficient heat resistance.

In recent years, there has been a strong demand for films with excellent properties of both slipperiness and transparency, especially in copying applications such as plate printing, X-ray photography, microfilm, electrophotography, and diazophotography. Since film properties and transparency are conventionally contradictory phenomena, the problem of imparting both properties has not yet been resolved.

Therefore, the present inventors have conducted intensive studies to improve the drawbacks of the conventional particle addition method and obtain a polyester film with a particularly excellent balance between slipperiness and transparency. Porosity is 40-9 at 380℃ or higher
It has been found that the goals of the invention can be achieved by using 5% crosslinked polystyrene particles.

[Problems to be Solved by the Invention] An object of the present invention is to produce a polyester containing crosslinked borisdylene particles having a specific thermal decomposition temperature and porosity, and having excellent slipperiness and transparency that could not be achieved with conventional techniques. An object of the present invention is to provide a composition.

[Means for Solving the Problems] The object of the present invention described above is to provide a polyester comprising a bifunctional acid component mainly consisting of an aromatic dicarboxylic acid and at least one type of glycol component at a thermal decomposition temperature of 380°C or higher. and a porosity of 40 to 95% and an average particle size of 0.01 to 5 μm
This is achieved by a polyester composition comprising crosslinked polystyrene particles.

The difunctional acid component of the polyester of the present invention is mainly an aromatic dicarboxylic acid or an ester-forming derivative thereof, and specifically, terephthalic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis (2-chlorophenoxy)ethane-4,4-dicarboxylic acid, its ester-forming derivatives include dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, 1,2-bis(2-chlorophenoxy)ethane-4,4 - dimethyl dicarboxylate, etc., among which terephthalic acid or dimethyl terephthalate is preferred. Examples of glycol components include ethylene glycol, butylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, and 1,4-cyclohexane dimetatool, with ethylene glycol being preferred. In addition to these dicarboxylic acids or their ester-forming derivatives and glycol components, other components may be copolymerized, such as diethylene glycol, propylene glycol, neopentyl glycol, polyalkylene glycol, p-xylylene glycol, Diol components such as 1,4-cyclohexane dimetatool, 5-sodium sulforesorcin, adipic acid, sebacic acid,
Dicarboxylic acid components such as phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 5-sodium sulfoisophthalic acid, polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxydicarboxylic acid components such as Kanooxyethoxybenzoic acid. Examples include acid components.

When the dicarboxylic acid component is a dicarboxylic acid, it is subjected to an esterification reaction with a glycol, and when it is a dicarboxylic acid ester, it is subjected to a transesterification reaction with a glycol, and then polycondensed at high temperature and under reduced pressure to obtain 1 q of polyester.

Moreover, polycondensation can also be carried out using the prepolymer itself as a starting material.

The crosslinked polystyrene particles used in the present invention are highly crosslinked particles and have heat resistance with a thermal decomposition temperature (10% decomposition temperature) of 380° C. or higher on a thermobalance. That is,
In order for the crosslinked polystyrene particles to function as a lubricant, they must have heat resistance so that they do not melt at the melt molding temperature during polyester polymerization. Preferably the pyrolysis temperature is 400
The temperature is preferably 410°C or higher, more preferably 410°C or higher. heat content v
If the N temperature is less than 380° C., particle force aggregation occurs during polyester polymerization or melt molding, making it impossible to use it as a lubricant.

In order to have such heat resistance, it is necessary to highly crosslink with divinylbenzene, and 12% by weight or more of pure divinylbenzene is required, preferably 30% by weight or more, and more preferably 50% by weight or more. % by weight or more.

Further, in order to obtain good transparency, the crosslinked polystyrene particles of the present invention need to have a porosity of 40 to 95%, preferably 50 to 80%. If the porosity is less than 40%, voids will occur when formed into a film, making it impossible to obtain good transparency. If it exceeds 95%, the shape stability of the particles becomes poor and it cannot be used as a lubricant.

The crosslinked polystyrene particles used in the present invention preferably have a spherical particle shape and a uniform particle size distribution from the viewpoint of transparency and slipperiness. That is, the volume shape factor is preferably 0.35 to 0.52, more preferably 0.45 or more [however, the volume shape factor f is expressed by the following formula. f=V
/D3, ■ is the particle volume (μm'), and D is the maximum diameter in the particle projection plane (μm>].

For example, with the method of pulverizing and making fine particles disclosed in Japanese Patent Publication No. 55-158937, it is difficult to obtain a uniform particle size distribution, and coarse particles are present, especially when forming into a film. This is undesirable because the product becomes unfavorable because it blocks the surface of the product and impairs its transparency, slipperiness, and aesthetic appearance.

The method for producing spherical cross-linked polystyrene particles with a uniform particle size distribution is to synthesize seed particles by soap-free emulsion polymerization, swell them using a swelling aid with a molecular weight similar to that of an oligomer, and absorb divinylbenzene and divinylbenzene. There is a way to make arrangements. In order to impart a specific porosity, that is, pore volume, to cross-linked polystyrene particles, an organic solvent or a polymer compound (Δ) soluble in an organic solvent is allowed to coexist during polymerization and cross-linking, and the polymerization reaction is performed. After completion, the compound (A) is obtained by removing the compound (A) from the produced crosslinked polystyrene particles. However, the method is not limited to these methods.

The average particle size of the crosslinked polystyrene used in the present invention is 0.01
It is necessary to set it to ~5μm, more preferably 0.05~
It is 2 μm. If the average particle size is less than 0.01 μm, the slipperiness will decrease when formed into a film. Furthermore, if the average particle size exceeds 5 μm, the transparency of the film decreases due to the generation of voids and increased scattering on the film surface due to coarse protrusions. Further, the amount of crosslinked polystyrene particles added to the polyester is preferably 0.001 to 10% by weight, more preferably 0.002 to 2% by weight.

Using the crosslinked polystyrene particles having a specific porosity of the present invention, The resulting biaxially stretched film has the characteristic of being able to simultaneously satisfy the antinomy phenomena of slipperiness and transparency, which have never been achieved with conventional techniques.

Furthermore, the particles of the present invention can also have a group capable of reacting with the polyester to form a covalent bond introduced into the crosslinked polystyrene in order to greatly improve the affinity with the polyester. Examples include carboxyl groups, hydroxyl groups, sulfonic acid groups, ester groups, etc. Methacrylic acid is used to introduce carboxyl groups, acrylic monomer is used for water M groups, and styrene sulfonic acid is used for sulfonic acid groups. Suitable, but not particularly limited. The amount of 7mers for introducing these active groups is preferably 1 to 10% by weight based on the particles.

Furthermore, in order to improve the heat resistance of the crosslinked polystyrene particles or to control the refractive index, the crosslinked polystyrene particles may be coated with an inorganic substance such as S i 02 or T i 02 .

The crosslinked polystyrene particles of the present invention can be added to and mixed with polyester by various known methods. Among these, it is particularly preferable to add it from the polyester polymerization initiation surface to the stage during the hand-combining reaction from the viewpoint of particle dispersibility. Preferably, the particles are added as a slurry of ethylene glycol during the precursor or polycondensation stage of producing the polyester composition. The slurry concentration is 0.5 to 20% by weight.
The degree is appropriate.

For dispersion in a dispersion medium such as ethylene glycol, a high-speed dispersion machine, a sand mill, a roll seal, etc. may be used, for example.

In addition, during dispersion, phosphorus atom-containing compounds such as phosphoric acid, phosphorous acid, and sodium phosphate, nitrogen atom-containing compounds such as tetraethylammonium hydroxinoids, and hydroxylamine, alkali compounds, cations, ions, and anions are used. The use of a surfactant such as an amphoteric or nonionic surfactant or a dispersant such as a water-soluble polymer further improves the dispersibility of the crosslinked polystyrene particles in the slurry and polymer, and is particularly preferred.

In addition, metal compound catalysts such as lithium, sodium, calcium, magnesium, manganese, zinc, antimony, germanium, titanium, etc., which are commonly used in the production of polyester, phosphorus compounds as color inhibitors, and non-organic materials other than crosslinked polystyrene particles. Particles and organic polymer fine particles can also be added as appropriate.

[Example] The present invention will be described in detail by giving examples below. Incidentally, each characteristic value of the obtained polyester was measured according to the following method.

(△) Particle size The average particle size was 50% as measured by electron micrograph of the particles.
It was determined by the equivalent spherical diameter of the particles corresponding to the volume % point. The equivalent spherical diameter is the diameter of a sphere that has the same volume as the particle.

(B) Thermal decomposition of particles Temperature increase rate Maro 2 under nitrogen atmosphere using Thermology Denki TAS-100
A thermobalance weight loss curve at 0° C./min was measured. The 10% weight loss temperature was defined as the thermal decomposition temperature.

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

(D> Intrinsic viscosity of polymer 0 Measured at 25°C using chlorophenol as a solvent.

(E) State of particle dispersion in polymer After the polymer was cut into ultra-thin sections of approximately 800 slices using an ultra-thin film production device, the state of particle dispersion in the polymer was observed using a transmission electron microscope.

The dispersion state was determined in the following three cases.

○: Almost no secondary agglomerated particles are observed, and the objective is achieved.

Δ: A slight amount of secondary agglomerated particles is present, and the purpose is not achieved.

×: Since most of the particles are secondary particles, the purpose is not achieved.

(F) Film characteristics 1) Surface roughness: Ra (μm) Shown as a value measured by stylus surface roughness (cutoff value 0.08111111, measurement length 0.5 m)
m0, but in accordance with JIS-B-8601. )2) Slip property The static friction coefficient (μS) and dynamic friction coefficient (μd) were measured using a slip tester according to ASTM-D-1894B-63.

3) Film haze Measured according to ASTM-Di 003-52.

4) Void stretching ratio: 3.3 times vertical, 3.6 times horizontal, stretching temperature 85
A 25μ thick 2[III] oriented film stretched at ~95°C was mounted on a slide glass with liquid paraffin, and the area A of the high brightness area (white area) was measured using an image analyzer (with a transmission optical microscope in the dark field). QTM90
0, manufactured by Cambridge Instruments). Next, using a phase-contrast microscope, the area B of the high i-intensity area and the low-luminance area (gray to black area in the same location) was determined using an image analyzer in the same manner as above, and the ratio of their areas (B/△
) was taken as the void ratio.

The evaluation criteria are as follows.

void ratio Achieve the objective in less than 0.06.

△: Achieved the objective with 0.06 to 0.13 do not.

x: Exceed 0.13 and achieve the objective. stomach.

Example 1 A transesterification reaction was carried out using 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol using a conventional method using 0.09 parts of calcium acetate as a catalyst, and 0.03 parts of antimony trioxide was added to the product. , dispersed as an ethylene glycol slurry containing 0.2 parts by weight of trimethyl phosphate and a concentration of 5% by weight, with a thermal decomposition temperature of 420°C.
1 Crosslinked polystyrene particles (volume shape coefficient 0.51>0.05 parts by weight) with an average particle diameter of 0.9 μm and a porosity of 60% are added and polymerized by a conventional method to obtain an intrinsic viscosity of 0.615 and a softening point of 260. Polyethylene terephthalate at 2°C was obtained.

As a result of observing the particles in the polymer using a transmission electron microscope, it was found that the particles were dispersed in a nearly monodispersed state with little secondary aggregation.

The polymer was melt extruded at 290°C, stretched at 85°C in the machine direction and 3.6 (8) in the dipping direction at 85°C. It was then heat set at 205°C and stretched into a 25 μm thick biaxial The stretched film was removed.As a result of evaluating the film properties,
The slipperiness and transparency were good (Table 1).

Examples 2 to 7 and Comparative Examples 1 to 4 Polyethylene terephthalate particles were prepared in the same manner as in Example 1 by changing the thermal decomposition temperature, porosity, and average particle size, with each containing crosslinked polystyrene particles having a volume shape factor of 0.51. It was made into a biaxially oriented film. When the crosslinked polystyrene particles contained within the thermal decomposition temperature, porosity, and average particle size were within the ranges of the present invention, they were made into films with excellent slipperiness and transparency (Examples 2 to 7).

However, when the thermal decomposition temperature, porosity, and average particle size of the crosslinked polystyrene particles contained were outside the scope of the present invention, it was not possible to satisfy both slipperiness and transparency (Comparative Examples 1 to 4).
).

Particles containing styrene, which is another polymer particle,
A biaxially oriented film of polyethylene terephthalate was prepared in the same manner as in Example 1 using colloidal silica as the acrylic co-merged particles and inorganic particles. None of them could satisfy both slipperiness and transparency.

(The following is a blank space) [Effects of the Invention 1 The polyester of the present invention contains crosslinked polystyrene particles having a specific thermal decomposition temperature, and therefore exhibits the following excellent effects.

(1) The crosslinked polystyrene particles of the present invention are highly crosslinked, thereby improving the heat resistance of the particles and allowing them to be extremely uniformly dispersed in the polymer. Therefore, it can be easily molded by ordinary molding methods, and the obtained fibers, films, or molded products are easily slippery between each other, and troubles such as clogging of the molding machine, thread breakage, and film tearing do not occur.

(2) Since the particles of the present invention have a refractive index close to that of PET and have excellent affinity, when made into a film, a film with good transparency can be obtained.

Such films are suitable for photographic and plate-making applications.

(3) The particles of the present invention have excellent affinity with polyester, so when made into a film, there are almost no voids and the particles have excellent abrasion resistance and electrical properties. Such a film is suitable for magnetic tape applications and capacitor applications.

Claims (1)

[Claims] A polyester consisting of a bifunctional acid component mainly consisting of an aromatic dicarboxylic acid and at least one type of glycol component has a thermal decomposition temperature of 380°C or higher and a porosity of 40 to 95%, and has an average particle size of 0. A polyester composition comprising crosslinked polystyrene particles of .01 to 5 μm.