JPH01225658A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a white film excellent in whiteness, covering power and dulness, by adding specified amounts of CaCO3 of a specified particle diameter, inorganic particles of a specified particle diameter and a phosphorus compound to a specified polyester. CONSTITUTION:5-50wt.% CaCO3 of a mean particle diameter of 0.05-5mum, 0.01-10wt.% (not inclusive) inorganic particles (e.g., SiO2) other than CaCO3, of a mean particle diameter of 0.06-10mum, and 100-5,000ppm (in terms of P atoms) of a phosphorus compound (e.g., trimethyl phosphate) are added to a polyester comprising at least 80mol.%, based on the total repeating units, ethylene terephthalate. Thus a polyester composition which is freed of agglomerated particles, has a high whiteness, is less yellowish and cannot be obtained heretofore can be obtained. This composition can give a white film excellent in whiteness, covering power, and dulness and can be desirably used as a base for sensitive papers, X-ray-sensitive papers, cards, labels, display boards, white boards, decorative use, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to polyester compositions. Specifically, it relates to a polyester composition containing a specific amount of calcium carbonate, inorganic particles other than calcium carbonate, and a phosphorus compound, and more specifically, to a white polyester film used as a substrate for cards, labels, display boards, white boards, etc. The present invention relates to a polyester composition suitable for use.

[Conventional technology]

Polyesters, represented by polyethylene terephthalate, have excellent physical and chemical properties and are widely used in fabrics, fibers, films, and other molded products. Among these uses, white films are particularly used as substrates 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, titanium oxide and barium sulfate are added in large amounts to gold (% Publication No. 56-4901), sulfuric acid (
There is an example (Japanese Patent Publication No. 60-30930) in which a large amount of lithium gold is added.

Furthermore, Japanese Patent Publication No. 43-12013 discloses adding a large amount of calcium carbonate.

However, in the above conventional technology, the particles added with barium sulfate have poor dispersibility, and when the resulting polyester is used to form a film, a film with sufficient whitening and hiding power cannot be obtained. . On the other hand, those containing titanium oxide have excellent hiding power due to the high refractive index of the particles, but a decrease in spectral reflectance in the low wavelength region of 450 nm or less is observed, making it difficult to obtain sufficient whitening. do not have.

Furthermore, when a large amount of calcium carbonate is added to polyester as exemplified in Japanese Patent Publication No. 43-12013, it is not preferable because particle aggregation occurs or a polymer with a strong yellowish color is obtained. When molded, a film with sufficient white discoloration cannot be obtained.

On the other hand, in order to use white film for cards, labels, display boards, etc., in addition to the film's white discoloration and hiding power, the film must also be matte to make it easier to read or see written characters such as printing and display characters. There is also a need to impart properties to the film.For boat fishing, the surface of the film is subjected to post-processing such as alkali treatment and sandblasting to roughen the surface.

However, these methods are not sufficient in terms of performance and have many disadvantages from an economic standpoint.

In addition, in order to eliminate this drawback, it is possible to roughen the film surface by incorporating particles with a large particle size into polyester, but roughening the film surface improves the matte property. However, it is difficult to provide sufficient white discoloration and concealing power.

[Problem that the invention seeks to solve]

The purpose of the present invention is to incorporate a large amount of white inorganic particles into polyester to obtain a molded product with excellent white discoloration, hiding power, and matting properties.
By using a polyester composition containing inorganic particles other than calcium carbonate and a phosphorus compound, the above-mentioned conventional drawbacks can be solved.

[Means for solving problems]

The object of the present invention as described above is to provide at least 80 repeating units.
Molch is a polyester made of ethylene terephthalate, and contains 5 to 50% by weight of calcium carbonate with an average particle size of 0.05 to 5μ, (B) an average particle size of 0.06 to 1
Inorganic particles other than calcium carbonate of 0μ i0.01-1.
This can be achieved by a polyester composition containing (C) a phosphorus compound in an amount of 100 to 5000 pprn as a P atom.

The polyester of the present invention means at least 8 repeating units.
It is a polyester consisting of ethylene terephthalate, and is produced by transesterification or esterification reaction and polycondensation reaction between a dicarboxylic acid, mainly terephthalic acid, or its ester-forming derivative, and a glycol, mainly ethylene glycol. Of course, the polyester may be a homopolyester or a copolyester. In the case of copolyester, examples of components to be copolymerized include diethylene glycol, neopentyl glycol, and
0 polyalkylene glycol, p-xylene glycol, 1,4-cyclohexane dimetatool, diol components such as 5-sodium sulforesorcin, adipic acid,
Dicarboxylic acid components such as sebacic acid, phthalic acid, isophthalic acid, λ6-naphthalene dicarboxylic acid, and 5-sodium sulfoisophthalic acid, polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid, p-oxyethoxybenzoic acid, etc. Examples include oxycarboxylic acid components.

The calcium carbonate referred to in the present invention may be either a natural product or a synthetic product, and its crystal form includes, but is not particularly limited to, calcite, aragonite, vaterite, and the like.

Further, calcium carbonate may be surface-treated with stearic acid, polyacrylic acids, a silane coupling agent, a titanium coupling agent, etc., and a surfactant such as sodium dodecylbenzenesulfonate may be used in combination.

The average particle size of calcium carbonate must be 0.05 to 5 μm, preferably 0.1 to 3 μm, and preferably 0.2 to 2 μm. When a film is formed when the average particle diameter is less than 0.05 μm or exceeds 5 μm, the desired film of the present invention cannot be obtained due to white discoloration and poor hiding power.

Furthermore, the content of calcium carbonate in the present invention is 5 to 5
It is necessary to set it to 0% by weight, preferably 6 to 40% by weight, and more preferably t-jlO to 30% by weight.

If this content is less than 5% by weight, when the resulting polyester is formed into a film, the desired film will not turn white and the hiding power will be insufficient. If the content exceeds 50% by weight, the dispersibility of particles in the polyester may be poor and the film strength may be insufficient.

Inorganic particles other than calcium carbonate in the present invention are not particularly limited, but include barium sulfate, silicon dioxide, magnesium oxide, alumina, talc, clay, and the like. Specifically, the use of silicon dioxide is particularly preferred since it provides high hiding power, high matting properties as well as whitening when formed into a film.

Furthermore, these inorganic particles may be used alone or in combination of two or more types.

The average particle size of the inorganic particles other than charcoal calcium in the present invention must be 0.06 to 10μ, preferably 0.1 to 7μ, and more preferably 0.3 to 5μ.

If the average particle diameter is less than 0.06μ, the dispersibility of calcium carbonate particles in polyester deteriorates, and when molded into an l+ film, the desired film of the present invention, such as poor hiding power or matting properties, cannot be obtained. . Also, if the average particle size exceeds 10μ, the film surface may become too rough.
Problems arise such as poor filterability during film production.

Further, the ratio of the average particle size of inorganic particles other than calcium carbonate to the average particle size of calcium carbonate of the present invention is not particularly limited, but from the viewpoint of matting properties of the film, it is preferably 1.1 or more, and more preferably 2. .0 or more is more preferable.

Furthermore, the content tFi of inorganic particles other than calcium carbonate in the present invention must be less than 0.01 to 1.0% by weight, preferably 0.05 to 0.9% by weight, more preferably 0.1 to 0.8% by weight. Weight%.

If this content is less than 0.01% by weight and the obtained polyester is formed into a film, the desired matting properties of the film will be insufficient. If the content exceeds 1.0, problems such as poor particle dispersibility in the polyester, excessively rough film surface, and poor filterability during film production will occur.

The phosphorus compound as used in the present invention refers to a compound that contains a phosphorus atom and is glycol-soluble.

Examples include phosphoric acid, phosphorous acid, phosphonic acid, and their derivatives.Specifically, phosphoric acid, phosphorous acid, trimethyl phosphate, tributyl phosphate, triphenyl phosphate, monophosphoric acid, etc. Alternatively, dimethyl ester, trimethyl phosphorous acid ester, methylphosphonic acid, methylsulfonated dimethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, etc. can be mentioned. Among these, use of phosphoric acid, phosphorous acid, and ester-forming derivatives thereof is particularly preferred.

Furthermore, these phosphorus compounds may be used alone or in combination of two or more.

The content of the phosphorus compound in the present invention is 1O as a P atom.
Must be O~5000 ppm, preferably 2
00 to 4000 ppm, more preferably 300 to 30
00 ppm.

If the content of the phosphorus compound is less than 100 ppm as P atoms, the dispersibility of calcium carbonate and inorganic particles other than calcium carbonate in the polyester will be poor. Alternatively, the color tone of the resulting polyester composition deteriorates, and when it is made into a film, sufficient white discoloration and hiding power cannot be obtained. On the other hand, if the content exceeds 5000 ppm' as P atoms,
There are drawbacks such as an increase in diethylene glycol as a by-product of polyester and significant deterioration of polyester, making it impossible to obtain a good film.

In the present invention, the ratio of the phosphorus compound content (weight loss as P atoms) to calcium carbonate and inorganic particles other than calcium carbonate is not particularly limited, but is preferable in order to obtain the desired whitening and hiding power of the film. Hao,
ooos~0.05, more preferably #'i0.001
~0.03.

As mentioned above, the present invention improves particle dispersibility in polyester by containing calcium carbonate of a specific particle size and inorganic particles other than calcium carbonate in a specific amount together, and by containing a phosphorus compound in a fixed amount of 't%. In addition to improving the color tone, when the polyester composition is formed into a film, it has the characteristic that a white film with excellent white discoloration, hiding power, and matte properties can be obtained.

The method of incorporating calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds into polyester of the present invention includes adding one or more of calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds in the polyester manufacturing process. , a method of tri-blending with polyester, and a method of melt-blending the polyester obtained by these methods within the scope of the present invention, etc. Although not particularly limited, it is preferable to use calcium carbonate or other materials other than calcium carbonate at any stage during polyester production. This method involves adding inorganic particles and a phosphorus compound. As for the specific production method, calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds may be added to the polyester reaction system at any time, preferably before the esterification or transesterification reaction during polyester production. The period is during the initial stage of the condensation reaction, and more preferably between the end of the esterification or transesterification reaction and the initial stage of the polycondensation reaction.

The method of adding calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds to the polyester reaction system is not particularly limited, and calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds may be added at the same time or in a mixture. May be added. In order to obtain particularly good dispersibility of calcium carbonate and inorganic particles other than calcium carbonate, a preferable addition method is to add km of calcium carbonate and inorganic particles other than calcium carbonate after adding a phosphorus compound, and to add km of inorganic particles other than calcium carbonate at intervals of 1 hour. within 30 minutes, more preferably within 30 minutes.

Calcium carbonate, inorganic particles other than calcium carbonate, and phosphorus compounds to be added to the polyester reaction system may be added as a powder or liquid, or in the form of a trench. From the viewpoint of particle dispersibility, it is preferable to add the particles in a slurry or liquid state mixed with an organic solvent such as glycol as appropriate. Furthermore, the slurry or liquid may be added after being heat-treated.

In addition, the polyester of the present invention may contain metal compound catalysts such as lithium, sodium, calcium, magnesium, manganese, zinc, cobalt, antimony, germanium, and titanium, which are commonly used during production, antioxidants, pigments, fluorescent brighteners, and surfactants. Agents, antistatic agents, etc. can also be added as appropriate.

Hikoo: When producing a film f from a polyester composition containing calcium carbonate, inorganic particles other than calcium carbonate, and a phosphorus compound according to the present invention, the polyester composition is formed into a sheet by a conventional method, and then The film is produced by stretching the film by 2.5 to 4.0 times in each biaxial direction and then heat-setting it at a temperature of 150° C. or higher.

The preferred density of the biaxially stretched film using the polyester composition obtained by the present invention is 0.90 to 1.38.
f/crr? , more preferably 0.95 to 1.35 f/
It is 2-. If the density is less than 0.90, the productivity and mechanical properties of the film will be poor, and if the density is more than 1.38, the desired film whitening and hiding power will not be obtained.

The polyester composition obtained in the present invention can also be preferably used in the field of molded products other than films, such as fibers.

〔Example〕

The present invention will be explained in more detail below using examples. Note that the characteristics in the examples were measured as follows.

A. Intrinsic viscosity of polymer Measured at 25°C using 0-chlorophenol as a solvent.

B. Softening point of polymer Place the polymer chip in a heating bath and heat at 6°C for 15 minutes.
The temperature at which the tip of the load penetrated 5 m into the chip was measured.

C. Particle dispersion in polymer 20 cm of polymer was sandwiched between two cover glasses at 280°C.
After cooling in the melt press, judgment was made by microscopic observation.

The judgment criteria are as follows.

○: Almost no particle collection is observed. (Within the objective range of the present invention.) Δ: Slightly aggregated particles are observed. (The object of the present invention is not achieved.) ×: Many aggregated particles are observed. (The purpose of the present invention is not achieved.) D. Hunter values (L, a,
Calculated from b).

◎: Confession 1f0 or more (especially within the objective range of the present invention) ○: White discoloration 55 or less and less than 70 (within the objective range of the present invention) △: White discoloration 53 or more and less than 55 (this invention (does not achieve the purpose of the present invention)
, film hiding power Macbeth transmission densitometer TD-504, thickness 175μ
The visible light transmission density of the film was measured and the hiding power was determined.

The transmission density here is calculated from the following equation.

Transmission density [-] X; Less than O, S (poor hiding power) △; 0°5~0
．． Less than 7 (slightly poor hiding power) ○: 0.7 to less than 1.0 (good hiding power) 071.0 or more (very good hiding power) D = -log (T / 100) where D: Transmission density [ -] T: Visible light transmittance (CH) F: Film whitening Reflectance R450 of 450 nm and 550 nm films with a thickness of 175μ measured at the original tungsten thickness using a Hitachi self-recording spectrophotometer EPE-2'i and R55O
It was determined by the following formula.

White discoloration (%) 4 R45O3R55゜◎; 95 inches or more (particularly preferred within the objective range of the present invention) ○; 90 inches or more, less than 95% (within the objective range of the present invention) △; 85 degrees or more, less than 90% (does not achieve the purpose of the present invention) ×; less than 85% (does not achieve the purpose of the present invention) G,
Matting property The 60 degree φ surface gloss was measured according to JIS z84741, and the film was judged based on its glossiness.

×: 60% or more (poor matte property) △; 50 inches or more to less than 60 inches (slightly poor matte property) 01
30% or more to less than 50% (good matting properties) ◎; Less than 30% (very good matting properties) Example 1 79 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and 0.09 parts by weight of calcium acetate. After carrying out the transesterification reaction according to a conventional method as a catalyst, an ethylene glycol solution containing 10% by weight of trimethyl phosphate was added as a phosphorus compound in an amount of 0.70i to the polymer, and the average particle diameter was adjusted for 10 minutes. 0.5μ
1ft of calcium carbonate: 50 parts by weight of ethylene glycol slurry containing 40% by weight and average particle size of 4.0
5 parts by weight of an ethylene glycol slurry containing 10 parts by weight of silicon dioxide of μ is added, and then 0.03 parts by weight of antimony trioxide is added as a polymerization catalyst. Thereafter, a polycondensation reaction is carried out according to a conventional method at high temperature and reduced pressure. Intrinsic viscosity 0.572, softening point 259.7°C, P content ij
1350 ppm of polyethylene terephthalate was obtained. As a result of observing the particle dispersion state of calcium carbonate and silicon dioxide in the polymer, no aggregated particles were observed. The color tone of the obtained polymer was very good, with a high white discoloration of 72.3 and very little yellowing.

0.03 parts by weight of fluorescent brightener "0B-1" (manufactured by Eastman) was added to 100 parts by weight of the obtained polyester, and biaxially stretched 3.2 times in length and 3.2 times in width according to a conventional method. A film with a thickness of 175 μm was obtained. The density of the obtained film was 1.15, there were no defects such as bubbles, and there was no white discoloration of 98.7.
It was a good white film with a hiding power of 1.27 and a gloss level of 28.

Comparative Example 1 Polyethylene terephthalate except silicon dioxide was obtained in the same manner as in Example 1. Although both the particle dispersibility of calcium carbonate in the polymer and the color tone of the polymer were excellent, Example 1. When a film was produced in the same manner as above, the matte properties of the film were poor.

Examples 2 to 9, Comparative Examples 2 to 7 As shown in Table 1, polyester and produced a film. The results are shown in Table-1.

Examples 2 to 9 are within the scope of the present invention, and have excellent particle dispersibility and color tone, and the films obtained from the polyester have no bubble defects and are good in self-separation, hiding power, and gloss. Ta.

On the other hand, Comparative Examples 2 to 7 are all outside the scope of the present invention, and are inferior in particle dispersibility, color tone, hiding power of the film, self-dispersion, and glossiness.Example 10 Same method as Example 1 Polyethylene terephthalate containing 25% by weight of calcium carbonate and 1350 ppm P content with an average particle size of 0.5 μm and polyethylene terephthalate containing 5% by weight of silicon dioxide and 70 ppm P content with an average particle size of 4.0 μm were produced.

80 parts by weight of the above-mentioned calcium carbonate-containing polyethylene terephthalate and 20 parts by weight of silicon dioxide-containing polyethylene terephthalate were melt-blended in an extrusion molding machine to obtain 20 parts by weight of calcium carbonate, 1.0 parts by weight of silicon dioxide, and 1.0 parts by weight of silicon dioxide.
A polyethylene terephthalate composition having a content of 1094 ppm was obtained.

Thereafter, a film was produced in the same manner as in Example 1.

The density of the obtained film was 1.17, 95.5% self-contained,
It was a good white film with a hiding power of 1.23 and a gloss level of 27%.

[Results of the invention]

As mentioned above, the present invention provides a specific amount of average particle diameter of 0.05 to
By incorporating calcium carbonate having a particle diameter of 5μ, inorganic particles other than calcium carbonate, and a phosphorus compound into a polyester, it is possible to obtain a polyester composition that does not contain agglomerated particles, has a high porosity, and has a low yellowish tinge, which has not been previously obtained. can.

When the polyester composition obtained according to the present invention is formed into a film, it is possible to produce a white film with excellent hiding power and matte properties, which can be used for photographic paper, X-ray intensifying screens, cards, labels, displays, etc. It is preferably used as a base material for boards, whiteboards, decorative purposes, etc.

Claims (1)

[Claims] (1) at least 80 mol% of the repeating units are polyester consisting of ethylene terephthalate, and (A)
5 to 50 pieces of calcium carbonate with an average particle size of 0.05 to 5μ
(B) less than 0.01 to 1.0 weight % of inorganic particles other than calcium carbonate with an average particle diameter of 0.06 to 10 μ;
and (C) a phosphorus compound with a P atom of 100 to 500
A polyester composition containing 0 ppm.