JP6000003B2 - Heavy calcium carbonate for synthetic resin, process for producing the same, and resin composition containing the calcium carbonate - Google Patents

Description

  The present invention relates to heavy calcium carbonate suitable for synthetic resins, particularly suitable for one-component adhesives and sealants, a method for producing the same, and a resin composition containing the calcium carbonate.

  Calcium carbonate is inactive, relatively inexpensive, and has little influence on the human body and is environmentally friendly. However, it has a hydrophilic surface, easily absorbs moisture, and is inferior in affinity with the resin. Therefore, in some cases, these defects have been improved by surface treatment, but for advanced applications, sufficient performance cannot be obtained due to poor adhesion to the resin and poor storage stability. There is.

One-component moisture-curable adhesives are designed so that the curing reaction proceeds with moisture in the air, but by adding fillers such as calcium carbonate, volume can be given to the adhesive, and the modulus can be reduced. Control to improve the workability of bonding or control the bonding strength. However, if moisture in the calcium carbonate is released and comes out in the resin containing the calcium carbonate, or if the calcium carbonate absorbs moisture over time in the resin, the curing reaction will occur before use as an adhesive. May adversely affect the storage stability of the adhesive and lead to performance degradation. There is a problem that the blending design is difficult, for example, it is necessary to blend a dehydrating agent for this measure.
There is a possibility that these problems can be solved if calcium carbonate with low moisture content, low hygroscopicity, or easily dried can be provided. For example, it is generally known that moisture treatment decreases after surface treatment after wet pulverization. However, dehydration and drying steps are essential, which is disadvantageous in terms of cost. Moreover, since the water | moisture content will increase when a specific surface area becomes large, use is restrict | limited.

  Various studies have been carried out to improve such moisture problems. For example, attempts have been made to dehumidify calcium carbonate filler by adding quick lime, but quick lime is a strong alkali, so its use is limited. The addition of a dehydrating agent such as vinyl silane has been studied, but there is a problem that it causes a cost increase.

  By the way, the storage stability of the sealant and the adhesive deteriorates when water is preliminarily present on the surface of the calcium carbonate particles, and it is easy to agglomerate. However, since moisture is taken into the interior, the moisture content is not sufficiently low.

  So far, the powder temperature is heated to 200-350 ° C. with high-speed stirring at a peripheral speed of 20 m / sec or more and dehydrated to reduce the water content to 0.02% by weight or less, and fatty acid metal soap or nonionic surfactant When a light calcium carbonate filler mixed at a temperature not lower than the melting point and up to 180 ° C. is mixed with plastic and injection molded to form a molded body having a thickness of 4 mm, a silver mark due to moisture does not occur, It has been reported that a molded article with greatly improved impact, surface gloss and heat resistance can be obtained. (Patent Document 1)

JP-A-61-97363

In the above Patent Document 1, heavy calcium carbonate having an average particle size of 3 μm and a moisture content of 0.1% by weight is dried for 25 minutes at a powder temperature of 280 to 300 ° C. while stirring with a Henschel mixer at a peripheral speed of 40 m / sec. At 160 ° C., 2% of calcium stearate was added at 160 ° C. to obtain a surface-treated heavy calcium carbonate having a moisture content of 0.009% by weight.
However, it is difficult for the equipment to be heated to 280-300 ° C with the heat of stirring of the Henschel mixer, and even if an oil medium is passed through the jacket, the seal part is damaged, and maintenance of the equipment is difficult and the powder is This is not preferable because it may be contaminated. Furthermore, silver marks are not generated in the applied physical properties in which this heavy calcium carbonate is blended with polypropylene, but the surface gloss and impact resistance are inferior, and a satisfactory effect is not obtained. In addition, when left in the atmosphere, moisture is re-adsorbed and a sufficiently low moisture cannot be maintained at the time of use, so that it is not possible to omit the one-component adhesive or one-component sealant drying step.

  In view of such circumstances, the present inventors consider that heavy calcium carbonate produced by physical means such as pulverization and classification of calcium carbonate is advantageous for reducing moisture because it has relatively low initial moisture. As a result of research, heavy calcium carbonate is adjusted to show the particle size characteristics required for adhesives and sealants aimed at, and dried by an appropriate heating method and heating conditions to reduce moisture, and further requires low moisture In this case, the present inventors have found that a filler produced by hydrophobizing surface treatment can solve the above problems, and completed the present invention.

  Therefore, the object of the present invention is advantageous in terms of cost because it can be produced in a dry process. For example, when blended in a one-pack type moisture-curable adhesive, it is sufficient to use a simple pre-drying without pre-drying. An object of the present invention is to provide heavy calcium carbonate that can greatly shorten the process.

A heavy calcium carbonate which is surface-treated with at least one selected from fatty acids and derivatives thereof and satisfies the following formulas (1) to (4).
9,800 ≦ A ≦ 20,000 (1)
1.5 ≦ B ≦ 15 (2)
0 ≤ C1 ≤ 780 (3)
0 ≤ C2 ≤ 150 (4)
However,
A: Specific surface area by air permeation method (cm ² / g),
B: 50% particle diameter (d50) of particles measured with a Microtrac MT3300 laser particle size distribution meter with an average particle diameter (μm) of calcium carbonate powder,
C1: moisture (ppm) measured between 25 and 300 ° C. by Karl Fischer method (heat vaporization method),
C2: Moisture (ppm) measured between 200 and 300 ° C. by Karl Fischer method (heat vaporization method).

Yet another feature of the invention, selected heavy calcium carbonate, an electric furnace, rotary kiln, after heat treatment at 3 00 ° C. or higher 800 ° C. or less by using a heating device selected from the microwave oven, fatty acids, derivatives thereof Surface-treating with at least one selected from the above-mentioned heavy calcium carbonate production method.

  Still another feature of the present invention is a resin composition comprising the above-described heavy calcium carbonate.

  Yet another feature of the present invention is that the resin is a curable resin.

Still another feature of the present invention is that the curable resin is a resin composition for a one-component adhesive or a one-component sealant .

  The surface-treated heavy calcium carbonate of the present invention is advantageous in terms of cost because it can be produced in a dry process. For example, when blended with a one-pack type moisture curable adhesive, it is not necessary to be pre-dried or a simple spare. Heavy calcium carbonate that can be sufficiently dehydrated by drying is provided. Furthermore, the cooling time when dried can be shortened. That is, it is possible to provide an adhesive and a sealant excellent in storage stability with little change in viscosity due to moisture even if the process is simplified.

The heavy calcium carbonate according to the present invention is surface-treated with at least one selected from fatty acids and derivatives thereof, and has the following particle size characteristics (1) and (2) and moisture represented by (3) and (4). It is characterized by satisfying the value.
9,800 ≦ A ≦ 20,000 (1)
1.5 ≦ B ≦ 15 (2)
0 ≤ C1 ≤ 780 (3)
0 ≤ C2 ≤ 150 (4)
However,
A: Specific surface area by air permeation method (cm ² / g),
B: 50% particle diameter (d50) of particles measured with a Microtrac MT3300 laser particle size distribution meter with an average particle diameter (μm) of calcium carbonate powder,
C1: moisture (ppm) measured between normal temperature and 300 ° C. by Karl Fischer method (heat vaporization method),
C2: Moisture (ppm) measured between 200 and 300 ° C. by Karl Fischer method (heat vaporization method).

The heavy calcium carbonate according to the present invention needs to have a specific surface area A by air permeation method of 8,000 to 25,000 cm ² / g, preferably 10,000 to 20,000 cm ² / g, more preferably 12,000 to 18,000. cm ² / g.
If the specific surface area A exceeds 25,000 cm ² / g, it is not preferable from the viewpoint of dispersibility, and the adsorbed moisture increases because the surface area is large. In order to omit the drying step, it is preferable to perform a surface treatment that makes the surface hydrophobic when it exceeds 10,000 cm ² / g. On the other hand, if it is less than 8,000 cm ² / g, the thixotropy is low and the workability is inferior for use in a sealant.

The specific surface area A by the air permeation method was measured by the following method.
It measured on the following measurement conditions using the constant-pressure-powder specific surface area measuring apparatus (Shimadzu make: SS-100).
Specific gravity of heavy calcium carbonate: 2.7 g / ml
Sample: 2.7 g
Amount of water to be aerated: 5 ml
Sample layer thickness: When the specific surface area is less than 10000 cm ² / g, the thickness is adjusted to 8 mm to 9 mm.
When the specific surface area is 10000 cm ² / g or more and 20000 cm ² / g or less, it is adjusted to 9 mm to 12 mm.
If the specific surface area exceeds 20000 cm ² / g, adjust between 12 mm and 13 mm.

The heavy calcium carbonate according to the present invention is required to have an average particle diameter B measured by Microtrack MT3300 manufactured by Leeds & Northrup Co., 0.8 to 15 μm, preferably 1.5 to 10 μm, more preferably 2 to 7 μm.
Although it is technically possible to reduce the average particle size B to less than 0.8 μm, it is not preferable because the amount of ultrafine powder increases, which is disadvantageous in terms of moisture removal, and also exists as aggregated secondary particles in the resin. On the other hand, if the average particle diameter B exceeds 15 μm, for example, precipitation occurs in the adhesive, which is not preferable.

Note that methanol was used as a medium used for measurement with the Microtrac MT3300.
In addition, the measurement was performed after irradiating at 300 μA for 60 seconds using an ultrasonic disperser Ultra Sonic Generator US-300T manufactured by Nippon Seiki Seisakusho as pre-dispersion in methanol slurry used for measurement.

The heavy calcium carbonate according to the present invention requires that the moisture C1 measured between 25 and 300 ° C. by the Karl Fischer method (heat vaporization method) be 1000 ppm or less, preferably 700 ppm or less, and more preferably Is 500 ppm or less. When C1 exceeds 1000 ppm, a normal drying step is required, and even if it is dried by heating under reduced pressure, the step takes time, and the subsequent cooling usually takes 3 to 4 hours. Therefore, the object of the present invention for obtaining a calcium carbonate filler capable of obtaining a one-component adhesive without pre-drying calcium carbonate cannot be achieved.
Further, the heavy calcium carbonate in the present invention, and the moisture C2 measured between 200-300 ° C. must be 0 ≦ C2 ≦ 150 (ppm), preferably 0 ≦ C2 ≦ 100 (ppm). More preferably, 0 ≦ C2 ≦ 50 (ppm). If C2 exceeds 150 ppm, there is a high possibility that the viscosity of the adhesive cartridge will increase with time, and the storage stability will be insufficient, and the object of the present invention will not be achieved.

For the moisture C1 and C2, heavy calcium carbonate is heat-treated at, for example, a product temperature of 200 ° C to 800 ° C, more preferably a product temperature of 250 ° C to 700 ° C, and still more preferably a product temperature of 300 ° C to 600 ° C. Can be made smaller. In particular, C2 reduced the specific surface area because ultrafine particles in heavy calcium carbonate powder were sintered on the surface of relatively large particles, or several tens of mesopores generated by pulverization were shrunk by sintering. As a result, it is thought that water content decreases. At a temperature lower than 200 ° C., only the adsorbed moisture on the powder surface is released and the chemically adsorbed moisture is not released. Further, it has a high hygroscopic property and cannot fulfill the object of the present invention. In addition, heat treatment at a temperature higher than 800 ° C. is not preferable because, depending on the residence time, quick calcification is performed to the inside of the particles, PH is increased, and coarse particles are aggregated by sintering.
Examples of the heating device used for the heat treatment in the present invention include a tunnel kiln, a roller house kiln, a pusher kiln, a shuttle kiln, a cart lifting kiln, an electric furnace, and the like. Examples of the rotary kiln include an external heating rotary kiln, an internal heating rotary kiln, and a batch rotary kiln. Furthermore, the microwave furnace etc. which combined the microwave with these heating apparatuses are mentioned. Preferably, a rotary kiln is preferable in consideration of cost, workability, and thermal history unevenness, and an external heating rotary kiln is particularly preferable. This is because the internal heat type rotary kiln may reduce the whiteness of the powder, and the batch type is inefficient when considering the surface treatment in the subsequent process.

The moisture C1 and C2 by the Karl Fischer method (heat vaporization method) were measured by the following method.
Using a moisture vaporizer (Mitsubishi Chemical Corporation: VA-100), the moisture content of heavy calcium carbonate was measured three times with a Karl Fischer method moisture meter (Mitsubishi Chemical Corporation: CA-100), and the average value thereof. It was.
In addition, a heavy calcium carbonate sample is measured after leaving still for 2 days or more in the room adjusted to 25 degreeC. The measurement conditions are as follows.
Temperature rise start temperature: 25 ° C
Temperature rise end temperature: 300 ° C
Step temperature: 100 ° C
End point detection level: 0.1 μg / s
Titration start delay time: 2 min
Conducting gas: N ₂ gas Conducting gas amount: 250 ml / min
Sample amount: 1g

The heavy calcium carbonate according to the present invention is preferably subjected to a hydrophobic surface treatment. This is because, in particular, when the specific surface area A exceeds 10,000 cm ² / g, after the heat treatment, the adsorbed moisture increases with time in proportion to the surface area. The amount of water to be re-adsorbed is a value sufficiently smaller than that in the case where heat treatment is not performed, but there is a problem in using it without a drying step. Normally, depending on the blending amount, if it exceeds 800 ppm, drying is required. Heat treatment can drastically shorten the drying time, but if it is used in a wide range, it needs to be surface treated to hydrophobize the surface and lower the surface tension. In particular, when viscosity or thixotropy is required, the particle diameter of heavy calcium carbonate needs to be small, and in such a case, sufficient low moisture cannot be obtained only by heat treatment.

  The surface treating agent used in the present invention can be used without any particular limitation as long as it is organic. Specific examples include fatty acid ester lubricants such as higher fatty acid esters of monohydric alcohols, higher fatty acid esters of polyhydric alcohols, and partial hydrolysates of very long chain esters of the Monta wax type; polyoxyethylene glycerin fatty acid esters Nonionic surfactants such as polyoxyethylene castor oil and hydrogenated castor oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester These may be used alone or in combination of two or more. Examples of the monohydric alcohol include methyl alcohol having 1 to 18 carbon atoms, ethyl alcohol, propyl alcohol, and butyl alcohol. Examples of the polyhydric alcohol include ethylene glycol, glycerin, sorbitol, and the like, and higher fatty acids. Examples thereof include lauric acid having 8 to 18 carbon atoms, myristic acid, palmitic acid, stearic acid and the like.

Furthermore, fatty acids such as oleic acid, lauric acid, myristic acid, isotridecyl myristate, palmitic acid, behenic acid, stearic acid, isostearic acid; amides, esters and bisamides of the fatty acids; higher alcohols such as stearyl alcohol or branched higher alcohols Metal soap-type lubricants such as barium stearate, calcium stearate, aluminum stearate, zinc stearate, magnesium stearate or composites thereof; C16 liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax and these Aliphatic hydrocarbon lubricants such as fluoride, chloride, etc .; silicone oil, soybean oil, coconut oil, palm kernel oil, linseed oil, rapeseed oil, cottonseed oil, Oils such as lily oil, castor oil, beef tallow, squalane, lanolin, hydrogenated oil; carboxylates such as N-acyl amino acid salts, alkyl ether carboxylates, acylated peptides; alkyl sulfonates, alkyl benzenes and alkyl naphthalene sulfonic acids Sulfonates such as salts, sulfosuccinates, α-olefin sulfonates, N-acyl sulfonates; sulfated oils, alkyl sulfates, alkyl ether sulfates, alkyl allyl ether sulfates, alkyl amide sulfates, etc. Sulfate ester salts; phosphate salts such as alkyl phosphates, alkyl ether phosphates, alkyl allyl ether phosphates; aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium Cationic surfactants such as salts and imidazolinium salts; Amphoteric surfactants such as ruboxybetaine type, aminocarboxylate, imidazolinium betaine, lecithin; polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene sterol ether, polyoxy Ethylene lanolin derivative, ethylene oxide derivative of alkylphenol formalin condensate, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, fatty acid alkanolamide, polyoxyethylene fatty acid ester amide, polyoxyethylene alkylamine, alkylamine Nonionic surfactants such as oxides; Fluorosurfactants; Polyoxyethylene allyl glycidyl nonyl Reaction-based surfactants such as phenyl ether and the like, which are used alone or in combination of two or more. Furthermore, it is used in combination with the above-mentioned nonionic surfactant.
Among these surface treatment agents, saturated fatty acids such as lauric acid, palmitic acid, stearic acid, and behenic acid, and methyl and butyl esters thereof are preferable in terms of performance and cost.

Since the heavy calcium carbonate obtained as described above has a low moisture content, it can be suitably blended in a curable resin that cures with moisture, such as an adhesive or a sealant. Examples of the one-component moisture-curable adhesive and sealant according to the present invention include one-component moisture-curable urethane resin, silicone resin, modified silicone resin, polysulfide, and epoxy resin.
One-part moisture-curing urethane resin adhesives and sealants are composed of polyols having a total molecular weight of 2 or more and a molecular weight of 100 to 20000, aromatic polyisocyanates, aliphatic or cycloaliphatic polyisocyanates. It consists of a urethane prepolymer obtained by reaction with a polyisocyanate compound such as isocyanates, a urethane prepolymer, a filler, an additive such as polyethylene fiber or silica, and a diluent.
Silicone resin adhesives and sealants contain at least one kind of silicone polymer having an alkoxysilyl group at the molecular end and an alkylene structure in the main chain, for example, a trialkoxysilyl group, an alkyldialkoxysilyl group, a dialkylalkoxysilyl group, etc. A polymer having a number average molecular weight of 1000 to 30000 having a polyalkylene structure of a repeating unit such as ethylene, propylene, butylene, and isobutylene at the molecular terminal is used.
The modified silicone resin adhesive and the sealant are polyether copolymers having hydrolyzable silicon functional groups at their ends, and the ends are hydrolyzed by the action of the curing catalyst, and the ends are bonded to each other and cured. There are those having an ether bond as the main chain structure. Specific examples include poly (methyldimethoxysilyl ether).
As the curing catalyst for the modified silicone resin, known ones can be used, for example, organic carboxylates such as tin octylate, tin stearate, iron naphthenate, lead octylate, di-n-butyltin-dilaurate, di- Organic tin such as n-butyltin-diphthalate can be used alone or in combination.
The modified silicone resin may be used alone, or an epoxy resin may be used in combination. Since the cohesive force and hardness of the adhesive can be imparted by using the epoxy resin in combination, it is only necessary to determine the formulation corresponding to the performance required for the adhesive layer.
When an epoxy resin is used in combination, an aliphatic polyamine, an alicyclic polyamine, a norbornanediamine-epoxy adduct, a hydrophilic ketimine, a hydrophobic ketimine, or the like, which is a curing agent for the epoxy resin, is employed.
Polysulfide resin adhesives and sealants are polymers having a reactive mercapto group at the end, and have a molecular weight of 200 to 20000, and the resin has a filler, plasticizer, reaction preparation agent, tackifier, etc. Those prepared by blending additives are used.
When the heavy calcium carbonate of the present invention is blended with these one-pack type moisture curable adhesives, the heavy calcium carbonate can be used without being pre-dried, which is very advantageous in terms of workability and cost.
The compounding amount of the heavy calcium carbonate of the present invention is adjusted as necessary, but is generally 1 to 200 parts by weight based on the total amount of these one-component moisture-curable adhesive and sealant. For example, in a one-component moisture-curing urethane resin adhesive, heavy calcium carbonate may be added and blended in an amount of about 10 to 300 parts by weight, preferably about 25 to 200 parts by weight with respect to 100 parts by weight of the urethane prepolymer.

  For the purpose of imparting appropriate viscosity and thixotropy to a one-component moisture-curing urethane adhesive and sealant composition, polyethylene fiber and silica are blended to make the coating workability, comb texture, sharpness, etc. And the cohesive force of an adhesive agent film can also be provided further. The blending amount is arbitrary, but for example, about 0.1 to 10 parts by weight, preferably about 0.5 to 8 parts by weight may be added to 100 parts by weight of the urethane prepolymer.

For the purpose of reducing the viscosity of the one-component moisture-curing urethane adhesive and sealant composition by a diluting action, for example, aromatic hydrocarbons such as toluene, xylene, mineral spirits, hexane, heptane, Aliphatic hydrocarbons such as octane, alicyclic hydrocarbons such as methylcyclohexane, petroleum solvents from gasoline to kerosene fraction, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB) , Esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and methylcyclohexanone, ether esters such as tetrahydrofuran, cellosolve acetate and butyl cellosolve acetate, N, N-dimethylformamide, N, N- Dimethylacetamide Examples thereof include nitrogen-containing solvents such as 1-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone. Furthermore, from the viewpoint of VOC countermeasures, N-alkyl-2-pyrrolidone (here The alkyl group may be any octyl group or more), 2,2,4-trimethyl-1,3-pentanediol isobutyrate-2-ethylhexanoate, 2,2,4-trimethyl-1,3-pentane Diol-2-ethylhexanoate, alkyl ester of ricinoleic acid (wherein the alkyl group has 1 or more carbon atoms), dialkyl ester of adipic acid (wherein the alkyl group has 8 or more carbon atoms), etc. You can also An aromatic solvent is preferable from the viewpoint of ease of handling and cost. As diluents and / or plasticizers, for example, dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butyl benzyl phthalate (BBP), dioctyl adipate, diisononyl phthalate, diisodecyl adipate, diisodecyl phthalate, trioctyl Examples include phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, propylene glycol adipate polyester, butylene glycol adipate polyester, alkylepoxystearate, epoxidized soybean oil, and the like. Can be used.
The blending amount is arbitrary, but for example, about 1 to 100 parts by weight, preferably about 5 to 50 parts by weight may be added to 100 parts by weight of the urethane prepolymer.

  Furthermore, conventionally known arbitrary components may be contained in the one-component moisture-curing urethane adhesive and sealant composition. For example, fillers such as aerosil, synthetic calcium carbonate, kaolin, clay, talc and silica sand can be used, but aerosil which does not require pre-drying is preferred. Any colorant such as titanium oxide, carbon black, other dyes or pigments, tackifier, thickener, silane coupling agent, titanium coupling agent, pigment dispersant, antifoaming agent, ultraviolet absorber, etc. Ingredients may be contained.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by this Example and a comparative example. In the following description, parts represent parts by weight.

Example 1
Super S (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, is used with an external heating rotary kiln (manufactured by Takasago Industry Co., Ltd .; external dimensions φ150 × 2000 mm), an external heating temperature of 620 ° C., a retort rotation speed of 4 rpm, and an angle. It heat-processed on conditions with 60 mm and input amount 6kg / h. At this time, the product temperature was 490 ° C. and the residence time was about 10 minutes. This product is allowed to cool, and a mesh with a mesh size of 75 μm is attached to a high-bolter type 300 (manufactured by Toyo Hitech; non-liner), and coarse particles and agglomerated particles are removed by sieving to have the powder physical properties shown in Table 1. Heavy calcium carbonate was obtained.

Example 2
The heat treatment was performed in the same manner as in Example 1 except that Super SS (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, was used. The product was allowed to cool and surface-treated using a supermixer SMV-20 (manufactured by Kawata). 6 kg of this product was put into a mixer, and after heating, the product temperature reached 70 ° C., 48 g of beef tallow fatty acid ester was added with stirring and the mixture was stirred and heated until the product temperature reached 130 ° C. Then, the surface treatment heavy calcium carbonate which has a powder physical property shown in Table 1 through the sieving process similarly to Example 1 was obtained.

Example 3
Super SSS (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, was subjected to strong heat treatment at 400 ° C. for 1 hour in an electric furnace. The product was subjected to a sieving step in the same manner as in Example 1 to obtain heavy calcium carbonate having powder properties shown in Table 1.

Example 4
Super SSS (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, was heat-treated in the same manner as in Example 3 and surface-treated in the same manner as in Example 2. The product was subjected to a sieving step in the same manner as in Example 1 to obtain a surface-treated heavy calcium carbonate having the powder physical properties shown in Table 1. However, the surface treatment agent was stearic acid, which was melted at 70 ° C. and added. The amount was 36 g.

Example 5
Surface treatment having the powder physical properties shown in Table 1 through heat treatment, surface treatment, and sieving step in the same manner as in Example 4 except that super # 1700 (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, was used. Heavy calcium carbonate was obtained. However, the surface treatment agent was butyl stearate, and the amount was 60 g.

Example 6
Surface treatment having the powder physical properties shown in Table 1 through heat treatment, surface treatment, and sieving step in the same manner as in Example 4 except that Super # 2000 (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate, was used. Heavy calcium carbonate was obtained. However, the amount of stearic acid as the surface treatment agent was 60 g.

Example 7
A surface-treated heavy calcium carbonate having the powder physical properties shown in Table 1 was obtained through the surface treatment and sieving step in the same manner as in Example 6 except that the temperature condition of the electric furnace was changed to 250 ° C. for 1 hour.

Example 8
Caltex 5 (manufactured by Maruo Calcium Co., Ltd.), a commercially available heavy calcium carbonate, was fed using a fluid classifier turbo classifier TC-15, feed rate 1.0 kg / h, rotor rotational speed 12000 rpm, air volume 1.5 m ³ / min. Classification was carried out under the conditions described above, and the coarse powder side was recovered. This was heat-treated at 400 ° C. for 1 hour in an electric furnace. The product was subjected to a surface treatment and a sieving step in the same manner as in Example 6 to obtain a surface-treated heavy calcium carbonate having powder properties shown in Table 1. However, the amount of stearic acid as the surface treatment agent was 82.5 g.

Comparative Example 1
N-35 (manufactured by Maruo Calcium Co., Ltd.) which is a commercially available heavy calcium carbonate.

Comparative Example 2
Super S (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available heavy calcium carbonate.

Comparative Example 3
MC coat S-13 (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available surface-treated heavy calcium carbonate.

Comparative Example 4
MC coat S-20 (manufactured by Maruo Calcium Co., Ltd.), which is a commercially available surface-treated heavy calcium carbonate.

Comparative Example 5
Surface treatment was performed in the same manner as in Example 8 except that classification was not performed, and a surface-treated heavy calcium carbonate having powder physical properties shown in Table 1 was obtained through a sieving step.

Examples 9-16, Comparative Examples 6-10
Using the heavy calcium carbonate obtained by Examples 1-8 and Comparative Examples 1-5, each synthetic resin composition was created in the following way, and the storage stability test was done. The test results are shown in Table 2.
Silica was pre-dried in an oven at 110 ° C. for 3 hours, but heavy calcium carbonate was not pre-dried.
(Polyurethane one-part adhesive)
L-1036: 540 parts made by Mitsui Takeda Chemical Co. (polyurethane resin)
Mineral spirit: 60 parts (solvent)
Aerosil 200: 2.4 parts, manufactured by Degussa Japan (silica)
Heavy calcium carbonate: 400 parts

<Storage stability test>
With the above blending, the mixture was stirred and mixed using a Dalton universal mixer (Dalton: 2 L) to obtain a synthetic resin composition. This is packed in a cartridge, and the viscosity after 23 ° C. × 1 day (2 rpm: V1, 20 rpm: V2) and TI value (TI ₂₃ value: V1 / V2) are measured, and then the viscosity after 70 ° C. × 1 day has passed. (2 rpm: V3, 20 rpm: V4), TI value (TI ₇₀ value: V3 / V4), and viscosity change rate (2 rpm: V3 / V1 × 100, 20 rpm: V4 / V2 × 100) And storage stability was evaluated.
<Appearance appearance>
Moreover, the synthetic resin composition mixed and stirred by the said mixing | blending was taken, and it extended thinly to about 1 mm to the slate board, and the external appearance was judged visually with the following criteria.
○: The coated surface is uniform and no aggregates are found.
Δ: The coated surface is uniform, but several aggregates can be confirmed.
X: The coated surface is non-uniform and many aggregates can be confirmed.
<Sedimentation test>
Moreover, the synthetic resin composition mixed and stirred in the above composition was put in a transparent mayonnaise bottle, left in a constant temperature and humidity chamber, and the synthetic resin composition after 70 ° C. × 7 days was visually observed according to the following criteria. It was judged.
○: There is no sediment at all, or a slight sediment is seen at the bottom of the bottle.
(Triangle | delta): Although a sediment is seen thinly at the bottle bottom, it can be used without trouble.
X: A hard cake is formed at the bottom of the bottle.

  As described above, the heavy calcium carbonate of the present invention can provide an adhesive having good storage stability and maintaining thixotropy even if the pretreatment drying step is omitted.

Examples 17-24, Comparative Examples 11-15
Using the heavy calcium carbonate obtained by Examples 1-8 and Comparative Examples 1-5, each synthetic resin composition was created in the following way, and the storage stability test was done. The test results are shown in Table 3.
Silica was pre-dried in an oven at 110 ° C. for 3 hours, but heavy calcium carbonate was not pre-dried.
(Modified silicone one-component sealant)
MS polymer 203: 540 parts Kaneka Corporation (modified silicone resin)
DINP: 30 parts J-Plus (solvent)
Aerosil 200: 8 parts Degussa Japan (silica)
KBM1003: 3 parts Shin-Etsu Chemical Co., Ltd. (dehydrating agent)
Neostan U220H: 1 part Nitto Kasei Co., Ltd. (tin catalyst)
KBM-603: 1 part Shin-Etsu Chemical Co., Ltd. (adhesive agent)
Heavy calcium carbonate: 100 parts

<Storage stability test>
With the above blending, the mixture was stirred and mixed using a Dalton universal mixer (Dalton: 2 L) to obtain a synthetic resin composition. This was packed in a cartridge, and the viscosity after 23 ° C. × 1 day (1 rpm: V1, 10 rpm: V2) and the TI value (TI ₂₃ value: V1 / V2) were measured. (1 rpm: V3, 10 rpm: V4), TI value (TI ₅₀ value: V3 / V4), and viscosity change rate (1 rpm: V3 / V1 × 100, 10 rpm: V4 / V2 × 100) And storage stability was evaluated.
<Dispersibility test>
Moreover, the synthetic resin composition mixed and stirred by the said mixing | blending was taken and spread thinly with a spatula so that it might become 5 cm or more length, 5 cm or more width, and 1 mm or less thickness on a glass plate. The appearance was visually judged according to the following criteria.
A: No aggregate of 0.5 mm or more is found on the coated surface of 5 cm square.
Δ: One or two aggregates of 0.5 mm or more are present on the 5 cm square coated surface.
X: There are 3 or more aggregates of 0.5 mm or more on the 5 cm square coated surface.

  As described above, the heavy calcium carbonate of the present invention can provide a sealant having excellent storage stability even if the pretreatment drying step is omitted.

As described above, the surface-treated heavy calcium carbonate of the present invention is advantageous in terms of cost because it can be produced in a dry process. For example, when blended with a curable resin such as a one-component moisture-curable adhesive or sealant, Provided is a surface-treated heavy calcium carbonate that can be sufficiently dehydrated without drying or with simple preliminary drying.
In addition, since the surface-treated heavy calcium carbonate of the present invention has low moisture properties, it is necessary to knead at high temperature because of its high moisture content, such as bioplastics, polyester resins that are easily hydrolyzed, such as PET and PEN. It is also suitable for resins called engineering plastics such as nylon and polycarbonate, and its usefulness is extremely large.

Claims (5)

A heavy calcium carbonate which is surface-treated with at least one selected from fatty acids and derivatives thereof and satisfies the following formulas (1) to (4).
9,800 ≦ A ≦ 20,000 (1)
1.5 ≦ B ≦ 15 (2)
0 ≤ C1 ≤ 780 (3)
0 ≤ C2 ≤ 150 (4)
However,
A: Specific surface area by air permeation method (cm ² / g),
B: 50% particle diameter (d50) of particles measured with a Microtrac MT3300 laser particle size distribution meter with an average particle diameter (μm) of calcium carbonate powder,
C1: moisture (ppm) measured between 25 and 300 ° C. by Karl Fischer method (heat vaporization method),
C2: Moisture (ppm) measured between 200 and 300 ° C. by Karl Fischer method (heat vaporization method). Heavy calcium carbonate, an electric furnace, rotary kiln, after heat treatment at 3 00 ° C. or higher 800 ° C. or less by using a heating device selected from the microwave oven, fatty acids, be surface treated with at least one selected from a derivative thereof The method for producing heavy calcium carbonate according to claim 1.   A resin composition comprising the heavy calcium carbonate according to claim 1.   The resin composition according to claim 3, wherein the resin is a curable resin.   5. The resin composition according to claim 4, wherein the curable resin is for a one-component adhesive or a one-component sealant.