JPH0699060A - Glycol based dispersion of calcium carbonate - Google Patents

Abstract

PURPOSE:To make the dispersion stability of calcium carbonate excellent and to prevent the generation of an aggregate at the time of condensation by stirring to mix and/or pulverizing calcium carbonate in a glycol, in which a copolymer of a certain kind of unsaturated carboxylic acid and a specific polyethylene glycol ether are added. CONSTITUTION:Calcium carbonate is stirred to mix and/or wet pulverized in the glycol, in which the 500-10000 av. molecular weight copolymer of a monomer of alpha,beta-monoethlenic unsaturated carboxylic acid and/or the salt and a monomer of polyethylene glycol ether of a 3-6C unsaturated alcohol are added. Thus, the glycol base dispersion body of calcium carbonate having excellent dispersion stability in the glycol and the polyester is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a glycolic dispersion of calcium carbonate. More specifically, in calcium carbonate used to improve the slipperiness and transparency of polyester fibers and films, the dispersion stability of submicron primary particles in glycol, which is the polymer raw material, is good, and the polyester weight is high. The present invention relates to a glycol-based dispersion of calcium carbonate, which can minimize the generation of aggregates composed of extremely fine particles, which are caused by addition during condensation.

[0002]

2. Description of the Related Art Demand for saturated linear polyester fibers, films, and other various molded products has been increasing due to the excellent physical and chemical properties of the polymer itself, and the required functions are diversifying. I am following. Particularly, in the case of fibers, titanium oxide, silica, for the purpose of imparting functions such as slipperiness, transparency, matting, ultraviolet shielding, antibacterial properties and hygroscopicity,
Various inorganic particles which are insoluble and inactive in polyesters such as aluminum oxide, precipitated barium sulfate, zinc oxide, mica, talc and kaolin are used. These so-called external particles are generally added in the polyester polycondensation step in a slurry state in which they are dispersed in a glycol solvent.

Polyethylene terephthalate (P) can be selected depending on the purpose of the function depending on the physical properties such as refractive index, specific gravity, hardness and particle size of each particle.
ET) physical properties required for inorganic particles used as external particles when it is desired to impart the texture such as the smoothness, suppleness, lightness, modest luster, deep color tone after dyeing, which is possessed by natural fibers such as silk. Has a refractive index close to that of polyester, low specific gravity, low hardness, and ultrafine grain size. However, there are few inorganic particles that can satisfy all of these characteristics. For example, titanium oxide has a large refractive index, increases opacity, has high specific gravity and hardness, and is not suitable except for the particle size.
Further, aluminum oxide, silica, etc. are not suitable because of their high hardness, and precipitated barium sulfate, zinc oxide, etc. are not suitable because of their large specific gravity.

It is well known that calcium carbonate satisfies the above-mentioned required properties in terms of physical properties such as refractive index, specific gravity and hardness, not limited to natural products and synthetic products, in contrast to these inorganic particles. However, the particle size distribution did not always meet the requirements sufficiently. That is, although the colloidal product of synthetic calcium carbonate (precipitated calcium carbonate) has a fine primary particle size of 0.04 to 0.15 μm as observed by an electron microscope, the strong agglomerated secondary particles in the drying process are ethylene glycol-based. And the primary particles are re-aggregated even if wet pulverization is performed in this solvent system, resulting in a particle size distribution in the polyester of 0.04 to several tens of μm.

To solve such problems, Japanese Patent Publication No. 48174/1990 discloses that wet precipitation is appropriately performed by using, as a raw material, a calcium carbonate glycol slurry having a specific particle size distribution and an average particle size in precipitated calcium carbonate. It is said that particles having good dispersion in glycol and having a uniform particle size distribution can be obtained. Further, in JP-A-64-4239 and JP-A-64-4240, α, β-monoethylenically unsaturated carboxylic acid and its salt and α, β-monoethylenically unsaturated carboxylic acid are added to calcium carbonate. A product obtained by wet-milling a glycol slurry using a salt of a copolymer with an ester and / or a copolymer as a surface-treating agent has good dispersion stability in glycol and good affinity with polyester. I am trying.

[0006]

However, calcium carbonate used in high-performance polyester fibers, films, and the like requires a finer particle size than that described in the above patent publication. Not only synthetic (precipitated) or natural (heavy) calcium carbonate, but also fine particles having an average particle diameter can be obtained by highly accurate dry or wet pulverization, classification or the like. However, the problem here is that especially in the case of calcite-based precipitated calcium carbonate, most of them are aggregates based on primary particles with a particle size of 0.04 to 0.15 μm observed by an electron microscope, regardless of the particle shape. Or agglomerates and agglomerates of these, and therefore, when pulverized with high energy, the primary particle size is
The problem is that the following ultrafine particles are produced in large quantities.

It is extremely difficult to prevent reaggregation of these calcium carbonate particles in glycol and polyester. Even if the copolymers and / or their salts in the above patent publications are used as a dispersant, the dispersion stability up to the primary particles cannot be expected. Further, since α, β-monoethylenically unsaturated carboxylic acid ester is used as a copolymerization monomer, it reacts with water mixed during the production of the dispersion or during storage to hydrolyze, and further during polyester polycondensation. Similarly, hydrolysis and transesterification also occur, causing a decrease in dispersibility and a decrease in compatibility.

From the above, it is possible to stabilize the dispersion in glycol and polyester to the particle size level of the inorganic particles used for the purpose of bringing the natural fibers of polyester fibers, films, etc., which are particularly required for PET fibers, to have a texture close to that of natural fibers. Creating a glycol-based dispersion of calcium carbonate having good properties has been a problem to be solved.

[0009]

SUMMARY OF THE INVENTION In view of the above situation, the present inventors have found that the main monomer component of a saturated linear polyester, carboxylic acid or its functional derivative, and calcium carbonate added in the polycondensation reaction step of glycol. In a glycol-based dispersion, the dispersion stability of calcium carbonate is good, and as a result of diligent examination of the dispersion that does not form aggregates during polycondensation, it was found that calcium carbonate in glycol contained a certain unsaturated carboxylic acid or a salt thereof. Addition of a copolymer of polyethylene glycol and a specific polyethylene glycol ether, stirring and mixing and / or wet pulverization allows calcium carbonate to be stably dispersed in submicron primary particles, and the occurrence of aggregates in polyester is also reduced. It was found that a glycol-based dispersion of calcium carbonate that can be obtained is obtained, and the present invention is completed. It led to.

That is, the present invention relates to calcium carbonate in glycol, and (A) one or more monomers selected from (a) α, β-monoethylenically unsaturated carboxylic acid and / or a salt thereof, (B) Addition of a copolymer of one or more monomers selected from polyethylene glycol ethers of unsaturated alcohols having 3 to 6 carbon atoms and having an average molecular weight of 500 to 10,000, The present invention provides a glycol-based dispersion of calcium carbonate, which is obtained by stirring and mixing and / or wet grinding.

The copolymer used in the present invention preferably has a ratio of the constituent monomers of (A) / (B) = 5/95 to 95/5 (molar ratio), more preferably (B). It is preferable that the average molecular weight of the polyethylene glycol moiety in the polyethylene glycol ether is 100-500. The amount of the copolymer added is 0 in terms of pure content with respect to calcium carbonate.
It is preferably from 01 to 20% by weight.

Typical α, β-monoethylenically unsaturated carboxylic acids used in the present invention are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. In addition, generally known α, β-monoethylenically unsaturated carboxylic acid monomers having polymerizability can be mentioned. Examples of the salts of these unsaturated carboxylic acids include alkali metal salts and ammonium salts of the above-mentioned generally known unsaturated carboxylic acid monomers such as sodium salts, potassium salts and lithium salts. To make the copolymer in the form of a salt, a method in which a monomer α, β-monoethylenically unsaturated carboxylic acid is copolymerized with the monomer (B) and then converted into a salt by a neutralization reaction , Or monomeric α, β
-There is a method of copolymerizing a salt of monoethylenically unsaturated carboxylic acid with the monomer (B), and any method may be used.

The unsaturated alcohol having 3 to 6 carbon atoms which constitutes the polyethylene glycol ether of the unsaturated alcohol having 3 to 6 carbon atoms of (B) used in the present invention includes allyl alcohol, crotyl alcohol, methacrylic alcohol, 1-hexene-3-ol, 2-hexene-1
-Ol, 3-hexene-1-ol, 4-hexene-
1-ol, 5-hexen-1-ol, 2-methyl-
3-buten-1-ol, 3-methyl-3-butene-1
-All, 1-pentene-3-ol, 2-pentene-
Examples include 1-ol and 4-penten-1-ol.
The polyethylene glycol ether may be prepared by any commonly used method, but it is common to add ethylene oxide to the unsaturated alcohol. The polyethylene glycol moiety in this polyethylene glycol ether preferably has an average molecular weight of 100 to 500. If this average molecular weight is less than 100, the affinity between polyester and calcium carbonate will deteriorate, and if it exceeds 500, the dispersibility of calcium carbonate in glycol may not be satisfied.

Further, (A) one or two selected from α, β-monoethylenically unsaturated carboxylic acid and / or its salt.
When polymerizing one or more kinds of monomers with (B) one or more kinds of monomers selected from polyethylene glycol ethers of unsaturated alcohols having 3 to 6 carbon atoms, it is preferable to carry out in an aqueous system. However, it is also possible to use an alcohol-based solvent, a ketone-based solvent or the like in the range in which the monomer and the copolymer are dissolved. The ratio of monomer (A) and monomer (B) is (A) /
The range of (B) = 5/95 to 95/5 (molar ratio) is preferable. If the amount of the monomer (A) exceeds the above range or is less than the above range, the dispersion stability of calcium carbonate cannot be maintained during the polycondensation, and the particles aggregate.

The polymerization initiator used in this polymerization can be selected from peroxide type, azo type, persulfate type, redox type depending on the polymerization temperature, the presence or absence of dissolution in a solvent, and the addition amount of the polymerization initiator. 0.1 to 50 based on the total amount of monomers
A weight% range is preferred. The average molecular weight of the copolymer thus obtained must be 500 to 10,000. When the average molecular weight is less than 500, the dispersibility of calcium carbonate is remarkably reduced, and when it exceeds 10,000, there is a problem that the glycol dispersion and the polyester after polycondensation are remarkably thickened. In the present invention, the molecular weight is measured by GPC by a conventional method. However, commercial products are indicated according to the label.

The calcium carbonate used in the present invention can be selected from calcite-based, aragonite-based, vaterite-based synthetic (precipitated) and / or natural (heavy) calcium carbonate. It may be pulverized and classified and / or wet-pulverized and classified in an aqueous or non-aqueous system, and then dried, pulverized and classified. Above all, those having a BET specific surface area of 3 to ²⁰ m ² / g are preferable. Here, the BET specific surface area is assumed to be measured by a single-point or multi-point method by an adsorption measuring device such as a volume method, a weight method, a flow method using a nitrogen adsorption method.

Examples of glycols used in the present invention include glycols such as ethylene glycol, propylene glycol and butylene glycol, which are raw materials for polyester production. In the present invention, the following method can be mentioned as a method for producing a glycol-based dispersion of calcium carbonate.

1) An appropriate amount of the above copolymer is added to a suspension obtained by pulverizing and / or classifying calcium carbonate in an aqueous or non-aqueous system, and the mixture is wet agitated and mixed, and then dried, pulverized, and classified calcium carbonate powder is used as a raw material. As the above, the mixture is put into glycol and stirred and mixed and / or wet pulverized until the calcium carbonate particles reach the required particle size distribution, to obtain a glycol-based dispersion of calcium carbonate.

2) Dry pulverization, classification and / or pulverization and / or classification in an aqueous or non-aqueous system, and then dry, pulverized and classified calcium carbonate powder, to which an appropriate amount of the above copolymer is added and dry agitated and mixed Is added as a raw material to glycol, and the mixture is stirred and mixed and / or wet pulverized until the calcium carbonate particles reach the required particle size distribution, to obtain a glycol-based dispersion of calcium carbonate.

3) Dry pulverization, classification and / or pulverization and / or classification in an aqueous or non-aqueous system, and then drying, pulverizing and classifying the calcium carbonate powder as a raw material at the same time and / or at the same time when it is added to glycol. Before and after that, an appropriate amount of the above-mentioned copolymer is added to glycol, and the mixture is stirred and mixed and / or wet-ground until the calcium carbonate particles reach the required particle size distribution, to obtain a glycol dispersion of calcium carbonate.

4) Dry pulverization, classification and / or pulverization and / or classification with an aqueous or non-aqueous system, and then the dried, pulverized, and classified calcium carbonate powder is put into glycol as a raw material, and calcium carbonate particles are required. After stirring and mixing and / or wet pulverization until the particle size distribution is reached, an appropriate amount of the above copolymer is added to this glycol slurry,
Further, the mixture is stirred and mixed to obtain a glycol-based dispersion of calcium carbonate.

In the above-mentioned manufacturing method, the water-based or glycol-based wet stirring / mixing method may be a propeller type, turbine type, paddle type, anchor type, gate type, ribbon type, screw type, etc. single-axis or multi-axis stirring blade. One or more of mechanical homogenizers, homomixers, agitators, dispersers, planetary mixers, mechanical homogenizers such as agitomo mixers and universal mixers, or forced homogenizers such as ultrasonic homogenizers and pressure homogenizers. The method of dry stirring and mixing can be selected as a mechanical stirring mixer having a rotary blade such as a ribbon type, a screw type, a paddle type, a rod type, a hoe type, and a disk type, and a mechanofusion.
One or two or more methods can be selected from mechanochemical treatment methods such as hybridization and saffusion system.

Further, as a wet pulverization method, the rotational energy of a rod, a pin or a disk is changed to glass, zircon,
Zirconia, alumina, etc. are converted into the collision energy of bead-shaped media for pulverization, attritors, sand mills, pearl mills, gran mills, dyno mills, and other wet pulverizers, and vibration are converted into collision energy of media for pulverization. In addition to the wet vibration ball mill, one or more methods can be selected from wet mills such as colloid mills.

The glycol-based dispersion of calcium carbonate according to the present invention is added in the polycondensation step of polyester fibers and films to give various functionalities required for these polymer products, and thus the calcium carbonate particles are dispersed. The BET specific surface area is 5 to 30 m ² / g, preferably 10 to 25
It is desirable to adjust to m ² / g.

Therefore, in the above production method, the calcium carbonate solid content concentration of the glycol-based dispersion for adjusting the calcium carbonate particles to the target particle size is 20 to 70% by weight,
It is preferably 30 to 60% by weight. When the concentration is lower than this, it is disadvantageous in terms of economy and efficiency, while when the concentration is high, it is considered that the dispersion has a high viscosity and causes an obstacle in the manufacturing process.

The amount of the above copolymer used is preferably 0.01 to 20% by weight, more preferably 1.0 to 10% by weight in terms of pure content, based on calcium carbonate. If the amount added is less than 0.01% by weight, it is difficult to obtain sufficient dispersion stability of the calcium carbonate particles in the glycol type and polyester polycondensation type. If the amount added exceeds 20% by weight, the polyester polycondensation system may have problems such as thickening.

By the above method, the dispersion stability of submicron primary particles in glycol, which is the raw material of polyester, is good, and the addition of the particles during polyester polycondensation causes the formation of agglomerates of extremely fine particles. It is possible to obtain a glycol-based dispersion of calcium carbonate in which the amount is reduced as much as possible.

[0028]

The glycol-based dispersion of calcium carbonate according to the present invention minimizes the generation of aggregates due to calcium carbonate particles in glycol and at the time of polyester polycondensation, and improves the compatibility with the polymer. It is characterized by using a copolymer as a dispersant.
Therefore, the requirements for the copolymer as a dispersant are 1)
Binding properties of copolymers on the surface of calcium carbonate particles, 2)
Affinity between the copolymer and glycol solvent and polyester, 3) Heat resistance and hydrolysis resistance of the copolymer. Of these, the requirement 1) is (A) one or two selected from α, β-monoethylenically unsaturated carboxylic acids and / or salts thereof.
More than one type of monomer, the requirements of 2), 3) are (B) carbon number 3 ~
Using one or more monomers selected from polyethylene glycol ethers of unsaturated alcohols of 6,
It is speculated that this can be satisfied by selecting the copolymer.

Further, a copolymer of a specific unsaturated carboxylic acid and / or salt thereof and an ether of polyethylene glycol having a specific molecular weight and an unsaturated alcohol in a specific molecular weight range, and the ratio of the copolymerizing monomer is By specifying, it is possible to obtain a dispersant that is compatible with both glycol solvent and polyester and is extremely stable under all conditions such as high pH, high temperature and high pressure. It is considered that it efficiently adsorbs under all conditions and exhibits high dispersibility such as electrostatic charge repulsion and steric repulsion.

In the present invention, the dispersion state of calcium carbonate in glycol or polyester is evaluated by the following means. Generally, particle size measurement methods include an electron microscope method and a Coulter counter method based on the counting principle, an X-ray cedigraph method and a centrifugal sedimentation light transmission method based on the sedimentation velocity principle, a laser light diffraction method and a laser Doppler method based on the electromagnetic wave scattering principle, Furthermore, the laser scanning method, the BET specific surface area method based on the adsorption principle, etc. can be mentioned. However, the dispersion state of calcium carbonate in glycol is clarified for the first time in a particle size measurement method using the same kind of glycol as a solvent, and it is possible to use electron microscopy, BET specific surface area method, and centrifugal sedimentation in an aqueous solvent. The particle size measurement method such as the light transmission method cannot evaluate the function of the glycol-based dispersion as a dispersant for the above copolymers and the like.

When glycol is used as a solvent, it is difficult to measure the viscosity based on the sedimentation rate because the viscosity is high. Therefore, it is suitable for measuring methods such as Coulter counter method, laser light diffraction method, laser Doppler method and laser scanning method. Limited. Among these measurement methods, the present inventors can measure not only the particle size distribution of calcium carbonate in a glycol solvent but also the particle size distribution in a polyester film by the laser scanning method.
Choose MODEL CIS-1 made by AI Co., Ltd. (Japan's exclusive agent, Central Scientific Trading), and use the glycol-based dispersion of calcium carbonate to
The particle size distribution of calcium carbonate when dispersed in the same glycol solvent, and further, the particle size distribution of calcium carbonate dispersed in the film of the polyester film to which this dispersion was added during polycondensation were measured. .

From these particle size measurement results, the glycol-based dispersion of calcium carbonate of the present invention was satisfactorily dispersion-stabilized to submicron primary particles in glycol, which is a raw material of polyester, and was added during polyester polycondensation. It has been clarified that the generation of agglomerates composed of extremely fine particles can be reduced as much as possible.

[0033]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 A commercially available heavy-duty calcium carbonate (Softon # 2200, made by Bihoku Kogaku Kogyo Co., Ltd.) in a 5 wt% methanol slurry was prepared,
The classified slurry that has been classified with a centrifugal force of 3000 G by a decanter type centrifugal separator is made into powder using a centrifugal thin film vacuum evaporator and a vacuum dryer, and this is crushed and classified to BET.
Calcium carbonate having a specific surface area of 11 m ² / g (hereinafter referred to as calcium carbonate A) was obtained. Add 150 parts of ethylene glycol (monoethylene glycol-Y, manufactured by Nippon Shokubai Co., Ltd.) to a mechanical stirrer (capacity 500 liters) with a disper type stirring blade
A copolymer of 30 mol% of sodium acrylate, 20 mol% of sodium maleate and 50 mol% of allyl ether of polyethylene glycol (average molecular weight 200) as a dispersant is prepared at the same time as 150 kg of calcium carbonate A is added. Then, 1.0 wt% in terms of pure content of calcium carbonate having an average molecular weight of 3000 was added and mixed by stirring. This slurry is wet-milled (Dyno Mill KD-45C
Type, manufactured by WAB, zirconia beads with media of 0.6 to 0.8 mmφ, media filling rate 80%, disk peripheral speed 12 m / sec) and wet pulverized to obtain a BET specific surface area of 16 m ² /
An ethylene glycol-based dispersion having a concentration of 50% by weight consisting of g of calcium carbonate was obtained.

FIG. 1 shows the particle size distribution of calcium carbonate when this dispersion is dispersed in an ethylene glycol solvent. For particle size distribution measurement, laser scanning MODE
Using L CIS-1 (manufactured by GALAI) with ethylene glycol (monoethylene glycol-Y, manufactured by Nippon Shokubai Co., Ltd.) as a solvent and adjusting the concentration of calcium carbonate to 5% by weight, an appropriate amount of pyrophosphoric acid was used. Add sodium aqueous solution (10% by weight), stir with a mixer (household) for 10 minutes,
Further, this suspension was diluted to 0.01% by weight with an ethylene glycol solvent, and ultrasonically dispersed for 1 minute. The chart in Fig. 1 shows the volume frequency histogram (PROBAB
It is an original chart of ILITY VOLUME DENSITY GRAPH).

Example 2 As a dispersant, a copolymer composed of 50 mol% of sodium acrylate, 25 mol% of sodium maleate and 25 mol% of polyethylene glycol (average molecular weight 300) methacrylic ether and having an average molecular weight of 4000 is calcium carbonate. On the other hand, an ethylene glycol-based dispersion having a concentration of 50% by weight and made of calcium carbonate having a BET specific surface area of 16 m ² / g was obtained by the same method as in Example 1 except that 1.0% by weight as a pure component was added. The particle size distribution of calcium carbonate when this dispersion was dispersed in an ethylene glycol solvent was measured by the same method as in Example 1, and the results are shown in FIG.

Example 3 As a dry stirring and mixing method, a mechanochemical type hybridization system (NHS-1 manufactured by Nara Machinery Co., Ltd.) was adopted, and raw material carbon dioxide per batch under mixing and dispersing conditions of a rotor rotation speed of 6400 rpm. A copolymer composed of 70 mol% of maleic acid and 30 mol% of polyethylene glycol (average molecular weight 200) allyl ether having a mean molecular weight of 1,500 as a dispersant, in which 500 g of calcium A was introduced, and 1.0% in terms of pure content of calcium carbonate The treatment was carried out for 3 minutes with addition of weight%. A 50% by weight ethylene glycol slurry of this surface-treated calcium carbonate was prepared and wet-milled (Dyno Mill KDL-PILOT, manufactured by WAB, glass beads with media 0.5 to 0.75 mmφ, media filling rate 80%, disk peripheral speed 10 m /
BET specific surface area
An ethylene glycol-based dispersion having a concentration of 50% by weight and containing 18 m ² / g of calcium carbonate was obtained. When the dispersion was dispersed in an ethylene glycol solvent, the particle size distribution of calcium carbonate was measured by the same method as in Example 1 and the results are shown in FIG.
Shown in.

Example 4 1 m ³ (solid amount: 62 kg) of lime milk having a concentration of 6% by weight was charged into a gas-stirring reactor having a volume of 2 m ³ (diameter: 1 mφ) and the temperature was 18 ° C.
30% by volume of CO ₂ gas is blown into the suspension system held at 1 at a superficial velocity of 4 cm / sec (1 atm, 0 ° C. conversion). As the reaction progresses, the viscosity of the entire system remarkably increases, but the viscosity after aging is 0.3P.
At the time of decrease before and after as, that is, when the carbonation rate reaches about 20%, the superficial velocity of CO ₂ gas is 2 cm / sec (1 atm, 0 ° C).
(Calculated), and the reaction was continued for about 2 hours in this state to obtain a colloid-precipitated calcium carbonate slurry (solid amount: 84 kg) having a BET specific surface area of 33 m ² / g. Next, the precipitated calcium carbonate slurry was heated to 70 ° C. and left to stand, and after 72 hours, it was confirmed that the pH of the slurry system was 12 or more,
The supernatant was removed and the concentration was adjusted to 12% by weight. For this slurry (maintained at 50 ° C) in terms of calcium carbonate solid amount
10 parts of lime milk (10% by weight) was added, and the above CO ₂ gas was adjusted to 0.
Blow at a superficial velocity of 5 cm / sec (1 atm, 0 ° C conversion),
The reaction was carried out until the pH of the system reached 9.5 ± 0.5. After repeating the same addition reaction 10 times, the pH of the slurry system was 7.5 ± 0.
The reaction was terminated when it reached 5. 50 mol% of sodium methacrylate as a dispersant was added to the calcium carbonate slurry (hereinafter referred to as calcium carbonate B slurry) obtained here.
A copolymer of 30 mol% sodium itaconate and 20 mol% polyethylene glycol (average molecular weight 400) allyl ether with an average molecular weight of 5000 is added to 1.5% by weight of calcium carbonate in terms of pure content and mixed by stirring. went.
The slurry was dried with a spray dryer, pulverized, and classified to obtain 160 kg of precipitated calcium carbonate having a BET specific surface area of 4.1 m ² / g.

After preparing a 50% by weight ethylene glycol slurry using 150 kg of the obtained precipitated calcium carbonate, the same wet pulverization method as in Example 1 was used to obtain a concentration of calcium carbonate having a BET specific surface area of 21 m ² / g. A 50% by weight ethylene glycol dispersion was obtained. The particle size distribution of calcium carbonate when this dispersion was dispersed in an ethylene glycol solvent was measured by the same method as in Example 1, and the results are shown in FIG. 7.

Example 5 Calcium carbonate B slurry was dried with a spray dryer, pulverized and classified, and as a result, BET specific surface area of 4.8 m ² /
g of precipitated calcium carbonate (hereinafter referred to as calcium carbonate B) was obtained. A copolymer of 90 mol% of ammonium acrylate and 10 mol% of polyethylene glycol (average molecular weight 400) allyl ether as a dispersant, using this calcium carbonate B as a raw material, and having an average molecular weight of 5,000 is converted to calcium carbonate as a pure component. Example 1 except that 1.5% by weight was added.
By the same method as described above, an ethylene glycol-based dispersion containing calcium carbonate having a BET specific surface area of 23 m ² / g and a concentration of 50% by weight was obtained. FIG. 9 shows the result of measurement of the particle size distribution of calcium carbonate when this dispersion was dispersed in an ethylene glycol solvent, in the same manner as in Example 1.

Comparative Example 1 A copolymer of 90 mol% sodium acrylate and 10 mol% polyethylene glycol (average molecular weight 100) allyl ether as a dispersant having an average molecular weight of 400 is 1.0 in terms of pure content with respect to calcium carbonate. By the same method as in Example 1 except that the ethylene glycol-based dispersion having a BET specific surface area of 16 m ² / g and a concentration of 50% by weight was obtained, an ethylene glycol-based dispersion was obtained. FIG. 11 shows the result of measuring the particle size distribution of calcium carbonate in the same manner as in Example 1 when this dispersion was dispersed in an ethylene glycol solvent.

Comparative Example 2 A sodium salt of a copolymer comprising 90 mol% of acrylic acid and 10 mol% of methoxypolyethylene glycol polypropylene glycol monomethacrylate as a dispersant, and 100% of all carboxyl groups in the copolymer are sodium. A concentration of calcium carbonate having a BET specific surface area of 16 m ² / g was measured by the same method as in Example 1 except that 1.0% by weight of neutralized one having an average molecular weight of 2000 was added to calcium carbonate in terms of pure content. A weight percent ethylene glycol based dispersion was obtained. FIG. 13 shows the result of measurement of the particle size distribution of calcium carbonate when this dispersion was dispersed in an ethylene glycol solvent, in the same manner as in Example 1.

Comparative Example 3 Sodium polyacrylate (average molecular weight 20
00) was added to calcium carbonate in an amount of 1.0% by weight in terms of pure content, and the BET specific surface area was measured in the same manner as in Example 1.
An ethylene glycol-based dispersion having a concentration of 50% by weight consisting of 16 m ² / g of calcium carbonate was obtained. When the dispersion was dispersed in an ethylene glycol solvent, the particle size distribution of calcium carbonate was measured by the same method as in Example 1 and the results are shown in FIG.
5 shows.

Application Examples 1 to 5 Using a vacuum emulsion stirrer (PVQS-5 type, manufactured by Mizuho Industry Co., Ltd.), 100 parts of dimethyl phthalate and ethylene glycol were used.
After transesterifying 64 parts by a conventional method using 0.04 part of manganese acetate tetrahydrate as a catalyst, 10% by weight of the ethylene glycol-based dispersion of calcium carbonate obtained in Examples 1 to 5 was used.
0.5% by weight of diluted slurry as calcium carbonate (relative to polymer), 0.03 part of trimethyl phosphate and as polymerization catalyst
0.035 parts of antimony trioxide were added with stirring. Then start depressurizing the reaction system at a reaction temperature of 250 ± 5 ℃, and in 90 minutes
280 ± 5 ℃ and reaction pressure below 2mmHg,
This state was continued for 4 hours to carry out a polycondensation reaction to obtain a PET polymer. MODEL CIS-1 (manufactured by GALAI) of laser scanning method of calcium carbonate dispersed in the polymer, which was obtained by sandwiching the obtained polymer between two cover glasses and melt-pressing at 280 ° C and quenching.
The particle size distribution measured by the particle size analyzer is shown in Figs.
8 and 10.

Application Comparative Examples 1 to 3 PET polymers were obtained in the same manner as in Application Examples 1 to 5 except that the ethylene glycol-based dispersions of calcium carbonate obtained in Comparative Examples 1 to 3 were added. The results of measuring these particle size distributions in the same manner as in Application Examples 1 to 5 are shown in FIG.
14 and 16.

What can be said based on the above-mentioned measurement results of the particle size distribution is that the ethylene glycol-based dispersions of calcium carbonate obtained by the methods of Examples 1, 2 and 3 are as shown in FIGS.
As shown in 3, 4, 5 and 6, the dispersion stability in ethylene glycol and polyester is very good. On the other hand, in the case of Examples 4 and 5, since the precipitation-produced calcium carbonate was used, a large amount of ultrafine particles were produced by high-energy pulverization, and the dispersions obtained in Examples 1 to 3 were compared with those in FIGS. , 10, some aggregated secondary particles are seen, but the dispersion stability is generally good.

Next, in Comparative Example 1, since the average molecular weight of the copolymer is small, the dispersing function is not sufficient and the results shown in FIGS.
As shown in (1), aggregated secondary particles of calcium carbonate are generated in both ethylene glycol and polyester. Further, since Comparative Example 2 uses α, β-monoethylenically unsaturated carboxylic acid ester as a copolymerization monomer, Comparative Example 3 further shows a homopolymer of α, β-monoethylenically unsaturated carboxylic acid. Since the alkali metal salt is used, as is clear from FIGS. 13 and 15, although the dispersion stability in ethylene glycol is good, FIG.
As shown in 16, at the time of polyester polycondensation, these copolymers undergo hydrolysis and transesterification,
Aggregated secondary particles of calcium carbonate, which are considered to be caused by the deterioration of the dispersion function, are generated in the polyester.

[0048]

As is apparent from the above Examples, Comparative Examples, Applied Examples and Applied Comparative Examples, the ethylene glycol-based dispersion of calcium carbonate according to the present invention is used in the glycol which is the raw material of polyester. It was clarified that the dispersion stability of the primary particles of micron is good, and that the generation of aggregates composed of extremely fine particles, which are caused by addition during the polyester polycondensation, can be reduced as much as possible. Therefore, when the glycol dispersion of calcium carbonate of the present invention is used as external particles such as polyester fiber and film, not only the slipperiness and transparency can be improved, but also the smoothness and suppleness required for the polyester fiber can be obtained. It is presumed that it is possible to satisfy the purpose of approaching the texture of natural fibers such as lightness, lightness, modest luster, and deep color tone after dyeing.

[Brief description of drawings]

FIG. 1 is an original chart of a volume frequency histogram by a laser scanning method when an ethylene glycol dispersion of calcium carbonate of Example 1 is dispersed in an ethylene glycol solvent.

FIG. 2 is an original chart of a volume frequency histogram by a laser scanning method showing a dispersion state in polyester obtained by adding the dispersion of Example 1 during a polyester polycondensation reaction.

FIG. 3 is an original chart similar to FIG. 1 for the dispersion of Example 2.

FIG. 4 is an original chart similar to FIG. 2 for the dispersion of Example 2.

5 is an original chart similar to FIG. 1 for the dispersion of Example 3. FIG.

FIG. 6 is an original chart similar to FIG. 2 for the dispersion of Example 3.

FIG. 7 is an original chart similar to FIG. 1 for the dispersion of Example 4.

FIG. 8 is an original chart similar to FIG. 2 for the dispersion of Example 4.

FIG. 9 is an original chart similar to FIG. 1 for the dispersion of Example 5.

FIG. 10 is an original chart similar to FIG. 2 for the dispersion of Example 5.

11 is an original chart similar to FIG. 1 for the dispersion of Comparative Example 1. FIG.

12 is an original chart similar to FIG. 2 for the dispersion of Comparative Example 1. FIG.

13 is an original chart similar to FIG. 1 for the dispersion of Comparative Example 2. FIG.

14 is an original chart similar to FIG. 2 for the dispersion of Comparative Example 2. FIG.

15 is an original chart similar to FIG. 1 for the dispersion of Comparative Example 3. FIG.

16 is an original chart similar to FIG. 2 for the dispersion of Comparative Example 3. FIG.

Claims (4)

[Claims] 1. Calcium carbonate in glycol, (A)
one or more monomers selected from α, β-monoethylenically unsaturated carboxylic acids and / or salts thereof,
(B) Copolymer with one or more monomers selected from polyethylene glycol ethers of unsaturated alcohols having 3 to 6 carbon atoms and having an average molecular weight of 500 to 10
A glycol-based dispersion of calcium carbonate, which is obtained by adding 000 of the above, stirring and mixing, and / or wet pulverizing. 2. The ratio of the constituent monomers of the copolymer is (A) /
(B) = 5/95 to 95/5 (molar ratio).
A glycol-based dispersion of the described calcium carbonate. 3. The polyethylene glycol moiety in the polyethylene glycol ether (B) has an average molecular weight of 100 to 100.
The glycol-based dispersion of calcium carbonate according to claim 1 or 2, which is 500. 4. The glycol-based dispersion of calcium carbonate according to claim 1, wherein the amount of the copolymer added is 0.01 to 20% by weight in terms of pure content with respect to calcium carbonate.