JPH08217961A - Polyester composition and molding obtained therefrom - Google Patents

Abstract

PURPOSE: To obtain a polyester composition in which calcium carbonate particles are highly dispersible and which has excellent heat resistance; and to obtain from the composition a molding excellent in whiteness, hiding power, and gloss. CONSTITUTION: This composition comprises a polyester (A) which is a copolymer of a phosphorus compound and calcium carbonate (B) whose spectrum obtained by the FT-IR diffusion reflection method has an absorption band in the range of 1,000-1,200cm<-1> and/or a polyester composition (C) containing calcium carbonate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition and a molded article made of the same, and more specifically to a phosphorus compound copolymerized polyester and FT-IR spectrum obtained by a diffuse reflection method of 1000 to 1200 cm.
^{The present} invention relates to a polyester composition containing calcium carbonate and / or a calcium carbonate-containing polyester composition having an absorption band between ⁻¹ and a molded article such as a film made of the same, and more specifically, photographic paper and X-ray. The present invention relates to a polyester composition suitable as a base material for an intensifying screen, a card, a label, a display board, a white board and the like, and a molded article such as a film made of the same.

[0002]

2. Description of the Related Art Polyester represented by polyethylene terephthalate has excellent physical and chemical properties and is widely used as a fiber, a film and other molded articles. Among these applications, a white film is used as a base material for cards, labels, display boards, white boards and the like.

Conventionally, it is well known to add a large amount of white inorganic particles to polyethylene terephthalate in order to obtain a white film. For example, Japanese Patent Publication No. 59-490
No. 1 discloses a large amount of titanium oxide and barium sulfate, and Japanese Patent Publication No. 60-30930 discloses a large amount of barium sulfate, and Japanese Patent Publication No. 60-30930 and Japanese Patent Publication No. 43-12013. Then, adding a large amount of calcium carbonate, and Japanese Patent Laid-Open No. 51-2814.
No. 1 and JP-A No. 61-209260 disclose a method of kneading an inorganic filler powder or a white inorganic pigment at a high concentration. However, in the above-mentioned prior art, the one to which barium sulfate is added is inferior in the dispersibility of particles, and when the obtained polyester is used to form a film, a film having sufficient whiteness, hiding power and gloss is obtained. I can't. On the other hand, the one to which titanium oxide is added has an excellent hiding power because of the high refractive index of the particles, but is, for example, 450 n.
Decrease in spectral reflectance in the low wavelength region below m,
A film having sufficient whiteness cannot be obtained.

Further, polyesters containing only high concentration of calcium carbonate as disclosed in JP-B-43-12013 and JP-A-51-28141 and JP-A-61-209260 are disclosed. When calcium carbonate is simply contained in a high concentration in the polyester by the method as disclosed, the calcium carbonate particles aggregate in the polyester due to the interaction and reaction between the calcium carbonate and the polyester. When it stays at high temperature, it will be denatured,
When the polyester composition, which becomes a foreign substance, stays at a high temperature, it foams and a polyester having good melt heat stability cannot be obtained.

As a result, the film obtained from the polyester composition is inferior in whiteness, hiding power and surface smoothness.

Further, in order to solve the above-mentioned drawbacks, JP-A-62-207337 discloses a method for producing a film by simply melt-extruding a mixture of polyester, calcium carbonate and a phosphorus compound. 6622
Japanese Patent Publication No. 2 discloses a method of adding calcium carbonate and a phosphorus compound to a polyester reaction system.

On the other hand, in JP-A-6-271682, in order to improve the transparency, slipperiness and abrasion resistance of the film, the polymer thermal stability at the time of melting is excellent, and the dispersibility and affinity of calcium carbonate particles for polyester are improved. A method of kneading powdery calcium carbonate and a specific amount of phosphorus atom-containing polyester with a vent-type kneading extruder is disclosed for the purpose of producing an improved polyester composition.

However, a method of simply kneading polyester with calcium carbonate and a phosphorus compound, a method of adding calcium carbonate and a phosphorus compound to the reaction system of polyester, or a method of simply adding calcium carbonate in a powder state and a specific amount of phosphorus atom-containing polyester The method of kneading with a vent-type kneading extruder can improve various problems caused by the above-described interaction / reaction between calcium carbonate and polyester to a certain extent. The reaction cannot be suppressed, it is difficult to efficiently contain calcium carbonate in a high concentration, the effect of improving the dispersibility of particles, and the effect of suppressing the generation of foreign matters and foaming when the polymer stays at high temperature are not sufficient. .

[0009]

DISCLOSURE OF THE INVENTION An object of the present invention is to contain a large amount of white inorganic particles in a polyester to obtain a molded article excellent in whiteness, hiding power, and glossiness, in order to obtain a phosphorus compound copolymerized polyester and FT. -Polyester composition comprising calcium carbonate and / or calcium carbonate-containing polyester composition having an absorption band between 1000 and 1200 cm ^-1 in the spectrum obtained by the IR diffuse reflection method, and molding of a film or the like comprising the same The purpose is to solve the above-mentioned conventional drawbacks.

[0010]

The above-mentioned object of the present invention is to obtain a spectrum obtained by the diffuse reflection method of FT-IR defined by phosphorus compound copolymerized polyester (A) and FT-IR defined in the text between 1000 and 1200 cm ^-1. And a calcium carbonate (B) having an absorption band and / or a calcium carbonate-containing polyester composition (C).

The polyester of the present invention can be produced by an esterification or transesterification reaction between a dicarboxylic acid or an ester-forming derivative and a diol and a subsequent polycondensation reaction. Fiber for the type of polyester,
There is no particular limitation as long as it can be molded into a film or other molded product. Suitable polyesters that can be molded into fibers, films and other molded articles are those using aromatic dicarboxylic acids as dicarboxylic acid components, such as polyethylene terephthalate and polyethylene-p-
Oxybenzoate, polyethylene-1,2-bis (2
-Chlorophenoxy) ethane-4,4'-dicarboxylate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-dicarboxylate, polyethylene-
2,6-naphthalenecarboxylate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate and the like can be mentioned, and among them, polyethylene terephthalate, polyethylene-2,6-naphthalene carboxylate and polybutylene terephthalate are preferable. Of course, even if these polyesters are homopolyesters,
It may be a copolyester, and as the copolymerization component,
For example, adipic acid, sebacic acid, dimer acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
5-Sodium sulfoisophthalic acid, diphenyldicarboxylic acid, 4,4'-sulfonyldibenzoic acid and other dicarboxylic acids or ester-forming derivatives thereof, trimellitic acid, pyromellitic acid and other polyfunctional carboxylic acids or ester-forming derivatives thereof , Oxycarboxylic acids such as p-oxyethoxybenzoic acid or ester-forming derivatives thereof,
Furthermore, ethylene glycol, butanediol, propylene glycol, diethylene glycol, neopentyl glycol, p-xylylene glycol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, polyalkylene glycol having an average molecular weight of 200 to 20,000, and the like. Is mentioned.

The polyester composition of the present invention has a spectrum obtained by the diffuse reflection method of FT-IR with the phosphorus compound-copolymerized polyester (A) in a range of 1000 to 1200 cm.
Carbonate (B) and / or calcium carbonate-containing polyester composition (C) having absorption band between ^-1
It is a polyester composition containing. The production method is not particularly limited, but is, for example, 1000 to 1200 cm in the spectrum obtained by the diffuse reflection method of phosphorus compound copolymerized polyester (A) and FT-IR.
Carbonate (B) and / or calcium carbonate-containing polyester composition (C) having absorption band between ^-1
Is directly melted and kneaded using a normal single-screw, twin-screw extruder or vent-type single-screw, twin-screw extruder, or a method of melt-kneading after mixing in advance with a blender, a mixer or the like, phosphorus compound copolyester ( After producing A), calcium carbonate (B) and / or calcium carbonate-containing polyester composition (C) is produced within the production process.
The method of melt-kneading can be mentioned. Among them, from the viewpoint of particle dispersibility of calcium carbonate, quality stability of the obtained polyester composition, foamability of polymer when retained at high temperature, generation of foreign matter due to calcium carbonate, etc., a normal single-screw or twin-screw extruder is used. Alternatively, a melt-kneading method using a vent-type single-screw or twin-screw extruder is preferable, and a melt-kneading method using a vent-type single-screw or twin-screw extruder is more preferable. The method of kneading and manufacturing with a vent type extruder is not particularly limited, but for example, the extrusion conditions are not less than the melting point of the polyester, the residence time is within 2 hours, preferably 1 minute to 1 hour, Is a vacuum degree of 10 as much as possible in order to remove decomposition gas components, low volatile components, and suppress polyester decomposition.
It is preferably 0 torr or less, preferably 10 torr or less, and further preferably 2 torr or less.

The phosphorus compound copolymerized polyester (A) of the present invention must have a phosphorus compound copolymerized.
The phosphorus compound copolymerized with the polyester is not particularly limited as long as it is a compound containing an element phosphorus and copolymerizable with the polyester. For example, phosphoric acid,
Examples thereof include phosphorous acid, phosphinic acid, phosphonic acid, phosphine oxide and derivatives thereof. Specifically, phosphoric acid, phosphorous acid, phosphoric acid trimethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester,
Phosphoric acid mono or dimethyl ester, dimethylphosphinic acid, phenylphosphinic acid, 2-carboxyethyl-methyl-phosphinic acid, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, tributylphosphine oxide, tris-3-hydroxypropylphosphine oxide, etc. Can be mentioned.

The method of copolymerizing the above-mentioned phosphorus compound with polyester is not particularly limited, and, for example, a method of adding the phosphorus compound at an arbitrary stage during the production of polyester can be adopted.

The amount of elemental phosphorus in the phosphorus compound copolymerized polyester (A) is not particularly limited, but the particle dispersibility of calcium carbonate in the obtained polyester composition,
From the viewpoints of quality stability of the polyester composition, foamability of the polymer when retained at high temperature, and generation of foreign substances due to calcium carbonate, the amount of phosphorus element in the polyester is 200.
It is preferably at least ppm, more preferably at least 300 ppm, further preferably at least 500 ppm, and particularly preferably at least 1000 ppm. When the phosphorus element content in the polyester is less than 200 ppm, the particle dispersibility of calcium carbonate in the obtained polyester composition is poor, or when the polyester composition stays at high temperature, the polymer foams or calcium carbonate Foreign matter may be generated due to.

The calcium carbonate (B) of the present invention is FT-I.
1000 in the spectrum obtained by the diffuse reflection method of R
Must have an absorption band between ~ 1200 cm ^-1 ,
Those which do not show an absorption band between 1000 and 1200 cm ⁻¹ are inferior in the particle dispersibility of calcium carbonate, the generation of foreign matters during high temperature retention of the polyester composition, and the foamability.

The spectrum obtained by the diffuse reflection method of FT-IR of the present invention means FT-IR of calcium carbonate.
(Biorat Digilab Co., Ltd. FTS60A / 896 resolution 4 cm ^-1 ) refers to the difference spectrum between the spectrum measured by the diffuse reflection method and the normal spectrum of calcium carbonate which has not been treated. The calcium carbonate of the present invention is This difference spectrum must have an absorption band between 1000 and 1200 cm ^-1 .

The method for obtaining the calcium carbonate (B) of the present invention is not particularly limited, but it can be obtained, for example, by surface treating calcium carbonate with various treating agents. Among various surface treatment agents, it is particularly preferable to perform surface treatment with a phosphorus compound. The phosphorus compound used for the surface treatment is not particularly limited, and examples thereof include phosphoric acid, phosphorous acid, phosphinic acid, phosphonic acid and their derivatives. Specifically, phosphoric acid, phosphorous acid, phosphoric acid trimethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid mono- or dimethyl ester, dimethylphosphinic acid, phenylphosphinic acid, 2-carboxyethyl-methyl-phosphine Examples thereof include acids, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, and the like, metal phosphates such as calcium phosphate, sodium phosphate, magnesium phosphate, manganese phosphate, and phosphorus compounds such as ammonium phosphate. . From the viewpoint of particle dispersibility of calcium carbonate in the obtained polyester composition, quality stability of the polyester composition, foamability of the polymer when retained at high temperature, generation of foreign substances due to calcium carbonate, etc. As, phosphoric acid, phosphorous acid, phosphinic acid, phosphonic acid and derivatives thereof or metal salts of phosphoric acid are preferable, more preferably phosphoric acid, phosphorous acid, phosphinic acid, phosphonic acid or their C 3 or less It is an alkyl ester compound. Further, two or more kinds of these phosphorus compounds may be used in combination. Further, the amount of phosphorus compound used for the surface treatment of calcium carbonate is not particularly limited, but from the viewpoint of the object of the present invention, it is 0.
It is preferably 1% by weight or more, more preferably 0.5 to 20% by weight, and particularly preferably 2.0 to 15% by weight. If the content of calcium carbonate is less than 0.1% by weight, the particle dispersibility of calcium carbonate may be poor, or foreign matter may be generated or foaming may occur when the polyester composition is retained at high temperature.

The amount of elemental phosphorus contained in calcium carbonate (B) is not particularly limited, but the amount of elemental phosphorus is 10
It is preferably contained in an amount of 0 ppm or more, more preferably 300 to 30,000 ppm, further preferably 50.
It is 0 to 20000 ppm. The amount of elemental phosphorus is 100p
If it is less than pm, the particle dispersibility of calcium carbonate may be poor, or foreign matter may be generated or foaming may occur during high temperature retention of the polyester composition.

Further, the surface treatment method of calcium carbonate with a phosphorus compound is not particularly limited, but a method of physically mixing calcium carbonate and a phosphorus compound can be mentioned, for example, a roll mill or a high-speed rotary pulverizer. ,
A crusher such as a jet mill or a mixer such as a Nauta mixer, a ribbon mixer and a Henschel mixer can be used.

The calcium carbonate (B) of the present invention is FT-I.
1000 in the spectrum obtained by the diffuse reflection method of R
It is characterized by having an absorption band between ˜1200 cm ⁻¹ , which can be confirmed by surface treating calcium carbonate with a phosphorus compound. By using calcium carbonate having this unique absorption band, the surface activity of calcium carbonate can be suppressed,
The particle dispersibility of calcium carbonate is improved, and the generation of foreign matters and foaming properties of the polyester composition during high temperature retention can be suppressed. This absorption band was generated as a result of treating the surface of calcium carbonate with a phosphorus compound and is presumed to be derived from a metal phosphate.

The calcium carbonate of the present invention may be a natural product or a synthetic product, and its crystal form may be any of calcite, anagolite and vaterite. Natural products are preferable from the viewpoint of dispersibility, and calcite is preferable as the crystal form. Further, other metal compounds such as magnesium oxide, aluminum oxide, silicon dioxide and the like may be contained.

The particle size and specific surface area of the calcium carbonate of the present invention are not particularly limited, but the average particle size is 0.01 to 20 μm, more preferably 0.1 to 10 μm.
In particular, 0.2 to 5 μm is preferable in terms of whiteness, hiding power and gloss. The specific surface area is preferably 0.5 to 100 m ² / g, more preferably 1 to 70 m ² / g, and particularly preferably 3 to 60 m ² / g in terms of whiteness, hiding power and gloss. When the average particle size of the particles exceeds 20 μm or the specific surface area is less than 0.5 m ² / g, the particle dispersibility in the polyester composition is good, but when the polyester composition is film-formed, it is white. In some cases, it is not preferable because of poor inferiority, hiding power and gloss. On the other hand, when the average particle size is less than 0.01 μm or the specific surface area exceeds 100 m ² / g, the dispersibility of particles in the polyester composition is remarkably poor and the polyester composition stays in a high temperature field. In this case, coarse foreign matter may be generated, foaming may occur, and further, a polyester having a high degree of polymerization may not be obtained, which is not preferable in some cases.

The calcium carbonate-containing polyester composition (C) of the present invention is not particularly limited as long as calcium carbonate is contained in the polyester, but the calcium carbonate particle dispersibility, the polyester composition obtained. From the viewpoints of quality stability of the product, foamability of the polymer when retained at high temperature, generation of foreign substances due to calcium carbonate, etc., the one containing calcium carbonate (B) is preferable. The method of incorporating calcium carbonate into polyester is obtained by, for example, a method of blending and adding calcium carbonate to polyester. Specifically, calcium carbonate is directly melted and kneaded into polyester using a conventional single-screw extruder, a vent-type single-screw extruder or a twin-screw extruder, or after being mixed in advance with a blender, a mixer or the like. And a method of adding and adding calcium carbonate at any stage of the polyester production process. Among them, particle dispersibility of calcium carbonate, quality stability of the obtained polyester composition,
From the viewpoint of foamability of polymer when retained at high temperature, generation of foreign substances due to calcium carbonate, etc., a method of melt kneading using an ordinary single-screw or twin-screw extruder or vent-type single-screw or twin-screw extruder is used. A method of melt kneading using a vent type uniaxial or biaxial extruder is preferable. The method of kneading and manufacturing with a vent type extruder is not particularly limited, but for example, the extrusion conditions are not less than the melting point of the polyester, the residence time is within 2 hours, preferably 1 minute to 1 hour, In order to remove decomposed gas components, low volatile components and suppress decomposition of polyester, the degree of vacuum is preferably 100 torr or less, preferably 10 torr or less, and further preferably 2 torr or less.

The calcium carbonate content in the calcium carbonate-containing polyester composition (C) of the present invention is not particularly limited, but in order to efficiently contain calcium carbonate in a high concentration in the obtained polyester composition. Is
It is preferable to contain 5 to 90% by weight in the polyester, more preferably more than 5% by weight and 80% by weight or less,
More preferably 10 to 70% by weight, particularly preferably 1
It is 5 to 60% by weight. When the content is less than 5% by weight, when the obtained polyester composition is formed into a film, the whiteness and the hiding property of the film are insufficient, which may not be preferable. When the content exceeds 90% by weight, the particle dispersibility of calcium carbonate in the polyester composition is poor, foreign matter is generated or foams when the polyester composition stays at high temperature, and a polyester having a high degree of polymerization is obtained. Since it is not possible, the film strength is not sufficient and may not be preferable.

The calcium carbonate content in the polyester composition of the present invention is not particularly limited, but it is preferably more than 5% by weight and 80% by weight or less, more preferably 20% by weight in the polyester composition. ˜70% by weight, particularly preferably more than 30% by weight and 60% by weight or less. When the content is 5% by weight or less, when the polyester composition is molded into a film, the whiteness of the film,
In some cases, the hiding property is insufficient, which is not preferable. When the content exceeds 80% by weight, the particle dispersibility of calcium carbonate in the polyester composition is poor, foreign matter is generated or foams when the polyester composition stays at high temperature, and further, a polyester having a high degree of polymerization is obtained. In some cases, the film strength is not sufficient and the film strength is not sufficient.

The phosphorus element content in the polyester composition of the present invention is not particularly limited, but the phosphorus element content is preferably 100 to 30000 ppm, more preferably 200 to 20000 pm, and further preferably 300 to. 10,000 ppm, particularly preferably 500-8
It is 000 ppm. If the amount of elemental phosphorus is less than 100 ppm, the particle dispersibility of calcium carbonate in the polyester composition may be poor, or foreign matter may be generated or foaming may occur during high temperature retention of the polyester composition. On the other hand, 30,000p
When it exceeds pm, a polyester having a high degree of polymerization cannot be obtained, which is not preferable in some cases.

As described above, the polyester composition of the present invention comprises the phosphorus compound copolymerized polyester (A) and FT-I.
1000 in the spectrum obtained by the diffuse reflection method of R
A polyester composition comprising calcium carbonate (B) and / or a calcium carbonate-containing polyester composition (C) having an absorption band between ˜1200 cm ⁻¹ . Phosphorus compound copolymerized polyester (A) and FT-IR
1000 by the spectrum obtained by the diffuse reflection method of
The calcium carbonate (B) having an absorption band between 1200 cm ^-1 and / or the calcium carbonate-containing polyester composition (C) may have some reaction with each other, probably because of excellent particle dispersibility of calcium carbonate in the polyester composition, Calcium carbonate can be efficiently and highly contained in polyester. Further, the polyester composition has excellent heat resistance without foaming or generation of foreign matter when retained at high temperature.

In particular, the polyester composition of the present invention obtained by the method of melt-kneading using a vent type single-screw or twin-screw extruder is excellent in the above-mentioned properties, and further the polyester composition of the present invention is produced. At this time, it is preferable in terms of removal of decomposed gas components and low volatile components and suppression of polyester decomposition, and calcium carbonate can be efficiently and highly contained in polyester.

The method for obtaining various molded products from the polyester composition of the present invention is not particularly limited, but various fibers can be prepared by melt spinning, various molded products can be prepared by extrusion molding or injection molding, and sheets can be prepared by melt extrusion. The film can be produced by stretching the film or by stretching the film. The various molded products obtained have slipperiness, glossiness,
It has excellent whiteness and hiding power.

A specific method for producing a film made of the polyester composition of the present invention will be described. After drying the polyester composition, it is melt extruded into an unstretched sheet, and then biaxially stretched and heat-treated to obtain a film. . Biaxial stretching may be either longitudinal or transverse sequential stretching or biaxial simultaneous stretching, and the stretching ratio is not particularly limited, but usually 2.0 to 5.0 times both longitudinal and transverse are suitable. Also,
After biaxial stretching, it may be re-stretched in either the longitudinal or transverse direction. At this time, the content of the modifier composed of calcium carbonate can be appropriately changed by mixing the polyester composition of the present invention with various polyesters. Further, various polyesters to be mixed may be the same as or different from the base polyester of the polyester composition of the present invention.

The film of the present invention can be obtained from the polyester composition by the method described above. The film of the present invention is not particularly limited, but in order to obtain a biaxially stretched film excellent in whiteness, glossiness and hiding property, the content of calcium carbonate in the film is more than 5% by weight and 40% by weight or less. And more preferably 7 to 30% by weight, especially 1
It is preferably 0 to 20% by weight. If the content of calcium carbonate is 5% by weight or less, the whiteness and the hiding property may be poor, which may not be preferable. If the content exceeds 40% by weight, the mechanical properties of the film may be inferior, which may be undesirable.
The density of the film is preferably 0.80 g / cm ³ or more in terms of film productivity and mechanical properties, and is preferably 1.38 g / cm ³ or less in terms of whiteness and hiding power.

The polyester composition and molded article of the present invention include other thermoplastic resins such as polyethylene,
Polypropylene, polystyrene, etc., various additives,
For example, UV absorbers, antioxidants, antistatic agents, surfactants, pigments, optical brighteners, and other inorganic particles, organic particles such as titanium dioxide, barium sulfate, clay, talc, kaolin, alumina, wet type In addition, dry type, inorganic particles such as spherical silica, and organic particles containing acrylic acid, styrene and the like as constituent components may be appropriately blended and added as necessary.

The film of the present invention may be a composite film comprising a layer composed of the polyester composition of the present invention and another polyester layer. The laminated structure at that time is not particularly limited as long as it has two or more layers. For example, a layer made of another polyester, for example, a transparent polyester layer, a roughened layer, or a layer having a polar group or a hydrophilic group may be laminated on at least one surface of the layer made of the polyester composition of the present invention. The thickness of these layers is not particularly limited,
0.001 to 10 μm is preferable. In addition to whiteness, these composite films have excellent surface glossiness, and conversely, due to the roughening, the matteness and the writability and the adhesiveness are improved.

[0035]

EXAMPLES The present invention will now be described in more detail with reference to Examples and Examples. The properties in Reference Examples and Examples were measured as follows.

A. Specific surface area and particle size of calcium carbonate The specific surface area is measured with a BET method surface area measuring device, and the particle size is an ultracentrifugal particle size distribution measuring device CAP manufactured by Horiba Ltd.
It was measured using A-700.

B. Amount of phosphorus element in polyester and calcium carbonate Wet decomposition of polyester and calcium carbonate with acid,
It was measured by the phosphomolybdenum blue colorimetric method.

C. Intrinsic viscosity of polyester It was measured at 25 ° C using an o-chlorophenol solvent.

D. Particle dispersibility in polyester 20 mg of polymer is sandwiched between two coverslips 280
After melt press cooling at ℃, it was judged by microscopic observation. A: No aggregated particles or coarse particles are observed. Δ: Aggregated particles or coarse particles are slightly observed. X: Many aggregated particles or coarse particles are observed.

E. Concealment of Film The visible light transmission density of a film having a thickness of 50 μm was measured with a Macbeth TD-504 transmission densitometer to determine the hiding property.
The transmission density here is calculated by the following equation. O · D = −log (T / 100) where O · D; transmission density [−] T; visible light transmittance [%]

F. Whiteness of film 50 nm thickness at 450 nm and 550 nm measured with a tungsten light source using Hitachi's own recording spectrophotometer EPE-2
It was calculated from the respective reflectances R ₄₅₀ and R ₅₅₀ of the film of m by the following formula. Whiteness (%) = 4R ₄₅₀ -3R ₅₅₀

G. Gloss of Film According to JIS Z84741, 60-degree specular gloss was measured to measure the gloss of the film.

Reference Example A 86 parts by weight of terephthalic acid and ethylene glycol 3
The esterification reaction product with 9 parts by weight was used as a storage portion, and 86 parts by weight of terephthalic acid and ethylene glycol
9 parts by weight were added, the esterification reaction was continued at 250 ° C., and the reaction product corresponding to 86 parts by weight of the terephthalic acid component was transferred to the polycondensation can from the reaction product having a reaction rate of 97% or more, and phosphoric acid was used as a phosphorus compound. After adding 0.60 part by weight of antimony trioxide, 0.04 part by weight of antimony trioxide was added, and then polycondensation reaction was performed according to a conventional method under a high temperature and reduced pressure of 290 ° C. to obtain an intrinsic viscosity of 0.61.
A phosphorus compound copolymerized polyester containing dl / g and 1500 ppm of phosphorus element was obtained.

Reference Examples B to D As shown in Table 1, phosphorus compound copolymer polyesters were obtained in the same manner as in Reference Example A, except that the phosphorus compound type and amount were changed.

[0045]

[Table 1] Reference Example E Calcite-type natural calcium carbonate powder having an average particle size of 1.2 μm and a specific surface area of 8.0 m ² / g was charged in a supermixer made by Kawata Co., Ltd., which is a fixed container type mixer, and was put into a rotor blade. The temperature was raised with stirring at a rotation speed of 760 rpm, and when the temperature inside the can reached 50 ° C., trimethyl phosphate as a phosphorus compound was added while being sprayed to 5% by weight with respect to calcium carbonate. Then mix for 10 minutes,
The surface was treated. The obtained calcium carbonate contained 7900 ppm of elemental phosphorus. Furthermore, a remarkable absorption band was confirmed at around 1120 cm ^-1 from the difference spectrum between the calcium carbonate not surface-treated and the calcium carbonate surface-treated, which was measured by the diffuse reflection method of FT-IR.

Reference Examples F to H As shown in Table 2, in the same manner as in Reference Example E, the kind of calcium carbonate and the kind and amount of the phosphorus compound of the surface treating agent were changed to obtain surface-treated calcium carbonate. Obtained. Table 2 shows the amount of elemental phosphorus in the obtained calcium carbonate. Further, from the difference spectrum between the non-surface-treated calcium carbonate and the surface-treated calcium carbonate measured by the diffuse reflection method of FT-IR, a remarkable absorption band was confirmed in the vicinity of 1120 cm ^{-1 for} both calcium carbonates.

[0047]

[Table 2] Reference Example I After mixing 30 parts by weight of the calcium carbonate powder of Reference Example E and 70 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.65 dl / g, the mixture was fed to a vent type twin-screw extruder using a feeder and vented. The mouth was maintained at a vacuum degree of 10 torr, and the mixture was kneaded at a temperature of 280 ° C. for a residence time of 5 minutes to obtain a polyester composition containing 30% by weight of calcium carbonate.

Reference Examples J to L As shown in Table 3, a calcium carbonate-containing polyester composition was obtained by changing the kind and amount of calcium carbonate in the same manner as in Reference Example I.

[0049]

[Table 3] Example 1 After mixing 85 parts by weight of the phosphorus compound copolymerized polyester of Reference Example A and 15 parts by weight of calcium carbonate of Reference Example E,
The mixture was fed to a vent type twin-screw extruder using a feeder, the vent opening was maintained at a vacuum degree of 10 torr, and the mixture was kneaded at a temperature of 280 ° C. for a residence time of 5 minutes to obtain polyethylene terephthalate containing 15% by weight of calcium carbonate. No foreign matter was generated during kneading and no foaming was observed. The particle dispersibility of calcium carbonate in the obtained composition was also good. Further, the amount of elemental phosphorus in the composition was 2100 ppm as measured by a colorimetric method.

Fluorescent whitening agent "OB-1" (manufactured by Eastman) 0.02 with respect to 100 parts by weight of polyethylene terephthalate containing 15% by weight of calcium carbonate obtained.
2 parts by weight are blended and dried thoroughly before being fed to the extruder.
Melted at 90 ℃, extruded in sheet form from T-shaped die, 3
An unstretched film was obtained by cooling and solidifying with a 0 ° C. cooling drum. Next, the unstretched film is heated to 95 ° C. and stretched 3.3 times in the longitudinal direction, further heated to 100 ° C. and stretched 3.3 times in the transverse direction, and heat treated at 200 ° C. to a thickness of 50 μm.
m film was obtained. The results of characteristics of the obtained film are shown in Table 4.

Density 1.21 g / cm ³ , whiteness 99%, O
・ D0.8, glossiness 29%, and whiteness, hiding power and glossiness were excellent.

Comparative Example 1 A polyester not copolymerized with a phosphorus compound having an intrinsic viscosity of 0.61 dl / g was obtained in the same manner as in Reference Example A except that the phosphorus compound was not added. Using the polyester and 15 parts by weight of non-surface-treated calcite-type natural calcium carbonate powder having an average particle size of 1.2 μm and a specific surface area of 8.0 m ² / g, a vent method was used in the same manner as in Example 1. Using a twin-screw extruder, polyethylene terephthalate and film containing 15% by weight of calcium carbonate were obtained. Table 4
Shows the results of various characteristics.

When a polyethylene terephthalate containing 15% by weight of calcium carbonate was produced using a vent type twin-screw extruder, foaming occurred in the polymer or the calcium carbonate particle dispersibility was poor. Further, tearing due to foaming was severe during the production of the film, and the obtained film was inferior in whiteness, hiding power and gloss.

Examples 2 to 8 As shown in Table 4, polyester compounds and films were obtained in the same manner as in Example 1 except that the phosphorus compound copolymerized polyester and calcium carbonate were changed in kind and amount.
Table 4 shows various characteristic results.

Examples 2 to 8 were within the scope of the present invention, the particle dispersibility of calcium carbonate in the obtained polyester was good, and the film was excellent in both whiteness and hiding power.

Comparative Example 2 A polyester containing no phosphorus element having an intrinsic viscosity of 0.61 dl / g was obtained in the same manner as in Reference Example A except that the phosphorus compound was not added. 85 parts by weight of the polyester, an average particle diameter of 1.2 μm, a specific surface area of 8.0 m ² / g, and a non-surface-treated calcite-type natural calcium carbonate powder 15
Parts by weight were mixed and thoroughly dried. Trimethyl phosphate as a phosphorus compound was mixed with this mixture in an amount of 5% by weight with respect to calcium carbonate, and then the mixture was fed to an ordinary non-vented single-screw extruder and kneaded at a temperature of 280 ° C. for a residence time of 5 minutes. Polyethylene terephthalate containing 15% by weight of calcium carbonate was obtained. Although no foreign matter was generated during the kneading, the viscosity of the polymer was remarkably reduced, and fine bubbles were found in the polymer. Further, aggregated particles or coarse particles of calcium carbonate were observed in the obtained composition.

A film was obtained in the same manner as in Example 1, except that polyethylene terephthalate containing 15% by weight of calcium carbonate was used. Table 4 shows various characteristic results.

The density of the obtained film was 1.29 g / cm.
³ , whiteness 85%, OD 0.6, gloss 20%, whiteness, concealment and gloss were almost good, but sometimes tearing due to foaming occurred during film production, and in some parts of the film Bubbles or breakage due to foaming occurred, and the melt heat stability was poor.

[0059]

[Table 4] Example 9 50 parts by weight of the phosphorus compound copolymerized polyester of Reference Example A and the calcium carbonate-containing polyester composition 50 of Reference Example I
After mixing with 1 part by weight, the mixture was fed to a vent type twin-screw extruder using a feeder, the vent opening was maintained at a vacuum degree of 10 torr, and the mixture was kneaded at a temperature of 280 ° C. for a residence time of 5 minutes to give 15% by weight of calcium carbonate. The contained polyethylene terephthalate was obtained. No foreign matter was generated during kneading and no foaming was observed. The particle dispersibility of calcium carbonate in the obtained composition was also good. Further, the amount of elemental phosphorus in the composition was 1500 ppm as measured by a colorimetric method.

Fluorescent whitening agent "OB-1" (manufactured by Eastman) 0.02 with respect to 100 parts by weight of polyethylene terephthalate containing 15% by weight of calcium carbonate obtained.
2 parts by weight are blended and dried thoroughly before being fed to the extruder.
Melted at 90 ℃, extruded in sheet form from T-shaped die, 3
An unstretched film was obtained by cooling and solidifying with a 0 ° C. cooling drum. Next, the unstretched film is heated to 95 ° C. and stretched 3.3 times in the longitudinal direction, further heated to 100 ° C. and stretched 3.3 times in the transverse direction, and heat treated at 200 ° C. to a thickness of 50 μm.
m film was obtained. The characteristic results of the obtained film are shown in Table 5.

Density 1.22 g / cm ³ , whiteness 98%, O
・ D0.8, glossiness 29%, and whiteness, hiding power and glossiness were excellent.

Examples 10 to 14 As described in Table 5, the phosphorus compound copolymerized polyester and the calcium carbonate-containing polyester composition were changed in kind and amount in the same manner as in Example 9 to obtain a polyester composition and a film. It was Table 5 shows the results of various characteristics.

Examples 10 to 14 were within the scope of the present invention, the particle dispersibility of calcium carbonate in the obtained polyester was good, and the film was excellent in both whiteness and hiding power.

[0064]

[Table 5]

[0065]

INDUSTRIAL APPLICABILITY As described above, the present invention provides calcium carbonate and / or calcium carbonate having an absorption band between 1000 and 1200 cm ^-1 in the spectrum obtained by the diffuse reflection method of phosphorus compound copolymerized polyester and FT-IR. A polyester composition containing a polyester composition containing the calcium carbonate particles, wherein the polyester composition has excellent dispersibility of calcium carbonate particles and excellent heat resistance, and the whiteness, hiding power, and luster can be obtained from the polyester composition. A molded product with excellent properties can be obtained. In particular, when a polyester composition is formed into a film, a white film excellent in whiteness, hiding power, and gloss can be produced, and such as photographic paper, X-ray intensifying screen, card, label, display board, white board, etc. It is preferably used as a base material.

Claims (9)

[Claims] 1. A phosphorus compound copolyester (A) and calcium carbonate (B) having an absorption band between 1000 and 1200 cm ⁻¹ in a spectrum obtained by the diffuse reflection method of FT-IR defined in the text and // Alternatively, a polyester composition containing a calcium carbonate-containing polyester composition (C). 2. The polyester composition according to claim 1, wherein the phosphorus compound content of the phosphorus compound copolymerized polyester (A) is 200 ppm or more. 3. The polyester composition according to claim 1 or 2, wherein the calcium carbonate (B) is surface-treated with a phosphorus compound. 4. The polyester composition according to claim 1, wherein the calcium carbonate-containing polyester composition (C) has a calcium carbonate content of 5 to 90% by weight. 5. A calcium carbonate content of more than 5% by weight, 80%
It is characterized by containing less than or equal to wt%.
6. The polyester composition according to any one of 1. 6. The polyester composition according to claim 1, wherein the phosphorus element content in the polyester composition is 100 to 30,000 ppm. 7. A molded article made of the polyester composition according to claim 1. 8. A film comprising the polyester composition according to claim 1. 9. A white film, wherein the film according to claim 8 is white.