Surface-treated calcium carbonate filler, and resin composition and molded article using same

Abstract

This surface-treated calcium carbonate filler satisfies the following formulae (a), (b) and (c): (a) 2.0 < = Sw < = 20.0 (m2 / g), (b) 300 < = Pw < = 5000 (ppm), and (c) 0.01 < = Tw < = 0.30 (mass%). Here, Sw is the BET specific surface area (m2 / g) of the surface-treated calcium carbonate filler, Pw is the phosphorus element content (ppm) of the surface-treated calcium carbonate filler as measured by an inductively coupled plasma (ICP) emission spectroscopic analysis device, and Tw is the decrement value (mass%) of the surface-treated calcium carbonate filler at 140-220 DEG C as measured by a differential thermal balance device.

Description

Technical Field

[0001] This invention relates to surface-treated calcium carbonate fillers, and resin compositions and molded articles using the same. Background Technology

[0002] Polyolefin resins, due to their excellent rigidity, impact resistance, heat resistance, formability, transparency, and chemical resistance, are widely used in a wide variety of applications, such as in various industrial materials, automotive parts, containers for medical supplies or cosmetics, and films and fibers for daily necessities and industrial use, for example, when combined with inorganic pigments like calcium carbonate. Furthermore, they are known to be relatively environmentally friendly resins, and there is anticipation for their use as a base material in green infrastructure applications. On the other hand, for resin compositions containing polyolefin resins that are melt-blended into finished products, there is a desire to further improve their weather resistance, heat resistance, and strength.

[0003] Furthermore, efforts have been made to stabilize resin compositions by adding metal soaps such as calcium stearate, or phenolic and phosphorus-based antioxidants, to melt-blended resins. Alternatively, efforts have been made to add calcium carbonate treated with fatty acids such as stearic acid or stearic acid soap to these resins, so that the function of calcium carbonate also improves resin stability (see, for example, Patent Document 1). Resin compositions obtained in this way are useful, for example, as materials for porous membranes (Patent Documents 2-4) that can be used in battery separators, etc.

[0004] On the other hand, in order to obtain such a resin composition, methods have been proposed such as using a super mixer, a drum mixer, or other mixers to premix the resin with antioxidants such as phenolic or phosphoric acid-based agents and then melt-mixing them; methods to simultaneously add the resin and additives separately and melt-mix them; and methods to side-feed the resin from the middle of the mixer where the resin is melting.

[0005] However, the antioxidants may not reach all parts of the resulting resin composition, or they may not function fully due to thermal degradation. Although the reasons are not yet clear, these methods all suffer from issues such as the antioxidants not reaching all parts of the resulting resin composition, not functioning fully due to thermal degradation, and insufficient thermal stability of the molded resin composition. Therefore, it is desirable to develop additives that can reach all parts of the resin composition, prevent thermal degradation, fully exert their lubricity function, and further improve the stability of the resin composition.

[0006] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2002-363443 Patent Document 2: Japanese Patent Application Publication No. 2006-169421 Patent Document 3: International Publication No. 2007 / 088707 Patent document 4: Japanese Patent Application Publication No. 2004-196917. Summary of the Invention

[0007] The problem that the invention aims to solve The present invention addresses the aforementioned problems and aims to provide a surface-treated calcium carbonate filler that improves the weather resistance, heat resistance, and strength of resin compositions obtained when compounded with resins such as polyolefin resins, as well as resin compositions and molded articles using the same.

[0008] Solution for solving the problem This invention relates to surface-treated calcium carbonate fillers that satisfy the following formulas (a), (b), and (c): (a) 2.0 ≤ Sw ≤ 20.0 (m) 2 / g) (b) 300≤Pw≤5000 (ppm) (c) 0.01≤Tw≤0.30 (mass%) (Sw is the BET specific surface area (m²) of the surface-treated calcium carbonate filler) 2 / g), Pw is the phosphorus content (ppm) of the surface-treated calcium carbonate filler, measured using an inductively coupled plasma (ICP) emission spectrometer. Tw is the weight loss (mass%) of the surface-treated calcium carbonate filler at 140℃~220℃, measured using a differential thermal balance.

[0009] In one embodiment, the surface-treated calcium carbonate filler of the present invention further satisfies the following formula (d): (d) 0.80≤bw≤1.50 The bw is the hue change rate calculated as follows: for a paste obtained by mixing the surface-treated calcium carbonate filler with dioctyl phthalate (DOP) at a mass ratio of 3:7, the yellow value (b value) before and after continuous heating at 140°C for 48 hours is measured using a spectrophotometer. Using this yellow value (b value), the following formula is used to calculate: Hue change rate (bw) = (b value of the paste after heating / b value of the paste before heating).

[0010] In one embodiment, the surface-treated calcium carbonate filler of the present invention further satisfies the following formulas (e), (f), and (g): (e)0.10≤D50≤2.00 (μm) (f)0.9≤(D90-D10) / D50≤2.0 (g) Da≤5.0 (μm) The D50 is the cumulative diameter (μm) from the small particle side in the volumetric particle size distribution of the surface-treated calcium carbonate filler, as measured using a laser diffraction particle size distribution measuring device. The D90 is the cumulative diameter (μm) from the small particle side in the volumetric particle size distribution of the surface-treated calcium carbonate filler, as measured by the laser diffraction particle size distribution measuring device. D10 is the cumulative diameter (μm) of the surface-treated calcium carbonate filler, measured using the laser diffraction particle size distribution measuring device, starting from the small particle side. Da is the maximum particle size (μm) in the volumetric particle size distribution of the surface-treated calcium carbonate filler, measured using the laser diffraction particle size distribution measuring device.

[0011] In one embodiment, the surface-treated calcium carbonate filler of the present invention is used to form a polyolefin resin composition.

[0012] In addition, the present invention is a resin composition characterized by comprising a resin and the above-mentioned surface-treated calcium carbonate filler.

[0013] In one embodiment, the resin is a polyolefin resin.

[0014] In addition, the present invention is a molded article composed of the above-described resin composition.

[0015] In one embodiment, the molded article of the present invention has a film morphology.

[0016] The effects of the invention According to the present invention, a resin composition with excellent heat resistance and easy mixing with resin can be provided. Furthermore, the surface-treated calcium carbonate filler of the present invention exhibits good dispersibility in resin, providing a resin composition that reduces resin scorching, agglomeration, or filter clogging during melt mixing, and exhibits excellent operational stability. Moreover, films obtained, for example, using the surface-treated calcium carbonate filler of the present invention and polyolefin resins are characterized by resistance to weathering and heat degradation. Detailed Implementation

[0017] 1. Surface-treated calcium carbonate filler First, the surface-treated calcium carbonate filler of the present invention will be described.

[0018] The surface-treated calcium carbonate filler of the present invention satisfies the following formulas (a), (b) and (c).

[0019] (a) BET specific surface area (Sw) The surface-treated calcium carbonate filler of the present invention has a specified BET specific surface area (Sw; m²) measured by nitrogen adsorption method. 2 / g). In this invention, the Sw of the surface-treated calcium carbonate filler is 2.0 ≤ Sw ≤ 20.0 (m 2 / g), preferably 3.0≤Sw≤15.0 (m 2 / g), more preferably 5.0≤Sw≤12.0 (m 2 / g). If the Sw of the surface-treated calcium carbonate filler is less than 2.0 (m 2 If the primary particles ( / g) become too large, they will reduce the strength of the resin composition when incorporated into it. Furthermore, due to the large primary particles, undesirable protrusions may sometimes form on the surface of the resulting resin molded article, reducing its slip properties. If the Sw of the surface-treated calcium carbonate filler exceeds 20.0 (m²), the primary particles will become excessively large, leading to a decrease in the strength of the resin composition when incorporated into it. 2 If the calcium carbonate used as filler in the surface treatment is reduced to a smaller size (e.g., g), the crystallinity of the calcium carbonate decreases, and the resulting resin composition obtained by mixing it with polyolefin resins or the like cannot have sufficient weather resistance or heat resistance. Moreover, as the primary particles become smaller, the cohesive force between the particles increases, so for example, it is sometimes impossible to disperse sufficiently when mixed with resin, and undesirable protrusions are formed on the surface of the resin molded article, which reduces the sliding properties of the resin molded article.

[0020] (Method for determining Sw) Regarding the Sw of surface-treated calcium carbonate filler, for example, Macsorb HM model-1201 manufactured by Mountech Corporation can be used, and the measurement can be performed as follows.

[0021] Specifically, approximately 300 mg of surface-treated calcium carbonate filler for testing was placed in the measuring apparatus as a pretreatment. After heating at 200°C for 10 minutes in a mixed nitrogen and helium atmosphere, low-temperature and low-humidity physical adsorption was performed in a liquid nitrogen environment, thereby determining Sw.

[0022] Sw can be controlled by changing various conditions during the manufacture of the surface-treated calcium carbonate filler of the present invention. Examples of conditions that allow Sw to be controlled within the aforementioned range include, for instance, the concentration of lime slurry used in the carbonation reaction, the temperature employed in the carbonation reaction, the concentration of carbon dioxide used, and the types and combinations of additives used in the carbonation reaction. When these conditions are not sufficiently set, it is sometimes difficult to obtain a surface-treated calcium carbonate filler that satisfies the aforementioned range of Sw.

[0023] (b) Phosphorus content (Pw) measured by inductively coupled plasma (ICP) emission spectrometry. The surface-treated calcium carbonate filler of the present invention has a specified phosphorus content (Pw; ppm) as measured by an ICP emission spectrometer. In the present invention, the Pw of the surface-treated calcium carbonate filler is 300 ≤ Pw ≤ 5000 (ppm), preferably 400 ≤ Pw ≤ 3000 (ppm), and more preferably 500 ≤ Pw ≤ 1500 (ppm). If Pw is less than 300 (ppm), the filler itself does not have sufficient heat resistance. If Pw is greater than 5000 (ppm), the resulting surface-treated calcium carbonate filler becomes prone to aggregation, its dispersibility in the resin decreases, and thus the required thermal stability in the resin composition cannot be achieved.

[0024] (Method for determining Pw) For example, Pw can be measured using the SPS3500 ICP emission spectrometer manufactured by SII NanoTechnology Co., Ltd., as follows.

[0025] (1) First, about 1000 mg of surface-treated calcium carbonate filler for testing was placed in a crucible and calcined in an electric furnace at 300°C for 3 hours.

[0026] (2) After firing, add a small amount (e.g., about 60 mL) of distilled water and 7.5 mL of 1.38 equivalent nitric acid (nitric acid (1.38) for the determination of harmful metals, manufactured by Fujifilm and Kojun Pharmaceutical Co., Ltd.) to a 200 mL beaker, boil the mixture in an electric furnace and cool it slowly.

[0027] (3) Add 100 μL of yttrium standard solution (Y1000 manufactured by Fujifilm and Koh Genuine Chemicals Co., Ltd.) to a 100 mL volumetric flask, add the mixture after slow cooling, and then dilute to 100 mL with distilled water.

[0028] (4) Then, filter with 5C filter paper and prepare a sample for ICP determination from the filtrate.

[0029] (5) Then, using the sample, the phosphorus content (ppm) in the sample is determined by the above-mentioned ICP emission spectroscopy analysis device.

[0030] (c) Decrease value (Tw) The surface-treated calcium carbonate filler of the present invention has a specified weight loss value (Tw; mass%) at 140°C to 220°C, measured using a differential thermal balance. In the present invention, the Tw of the surface-treated calcium carbonate filler is 0.01 ≤ Tw ≤ 0.30 (mass%), preferably 0.01 ≤ Tw ≤ 0.20 (mass%), and more preferably 0.01 ≤ Tw ≤ 0.15 (mass%). If Tw is less than 0.01 (mass%), although the physical properties of the filler itself are not problematic, a large production load is required to improve the crystallinity of the calcium carbonate constituting the filler. If Tw is greater than 0.30 (mass%), the resulting surface-treated calcium carbonate filler does not have sufficient heat resistance, making it difficult to obtain a resin composition with excellent weather resistance, heat resistance, and strength.

[0031] (Method for determining Tw) Tw can be measured using a differential thermal balance (such as the DTG-60A manufactured by Shimadzu Corporation) as follows.

[0032] (1) First, weigh about 30 mg of surface-treated calcium carbonate filler in a platinum sample pan and place it in the measuring instrument.

[0033] (2) Subsequently, the temperature of the measuring instrument was increased from room temperature to 550°C at a heating rate of 30°C / min, and the measurement was performed to calculate the weight loss (mass%) of each 1g of surface-treated calcium carbonate filler up to 140°C to 220°C.

[0034] Furthermore, the surface-treated calcium carbonate filler of the present invention is more preferably, in addition to the above formulas (a) to (c), it also satisfies the following formula (d).

[0035] (d) Hue change rate (bw) The surface-treated calcium carbonate filler of the present invention preferably has a specified hue change rate (bw), which is calculated as follows: for a paste obtained by mixing the surface-treated calcium carbonate filler with dioctyl phthalate (DOP) at a mass ratio of 3:7 (also called "DOP paste"), the yellow value (b value) before and after continuous heating at 140°C for 48 hours is measured using a spectrophotometer, referring to JIS K 7368:1999 (Plastics—Polypropylene and propylene copolymers—Determination of thermal oxidative stability in air—Oven method), and the hue change rate (b value) is calculated based on this yellow value (b value). It should be noted that the hue change rate (bw) can be calculated by the following formula: Hue change rate (bw) = (b value of the paste after heating / b value of the paste before heating).

[0036] In this invention, the bw of the surface-treated calcium carbonate filler is preferably 0.80 ≤ bw ≤ 1.50, more preferably 1.00 ≤ bw ≤ 1.20. If bw is less than 0.80, although the physical properties of the filler itself are not problematic, a large production load is required to improve the crystallinity of the calcium carbonate constituting the filler. If bw is greater than 1.50, the resulting surface-treated calcium carbonate filler does not have sufficient heat resistance, making it difficult to obtain a resin composition with excellent weather resistance, heat resistance, and strength.

[0037] (Method for determining bw) bw can be measured, for example, as follows.

[0038] (1) First, weigh the surface-treated calcium carbonate filler and dioctyl phthalate (DOP) in a mass ratio of 3 to 7, and mix them with a degassing mixer (e.g., Mazerustar manufactured by Kurashiki Spinning Co., Ltd.) to make DOP paste.

[0039] (2) Subsequently, the color difference of the DOP paste was measured using a spectrophotometer (e.g., Nippon Denshoku Co., Ltd. ZE-2000) as the "b value of the paste before heating".

[0040] (3) Subsequently, the DOP paste was placed in a glass petri dish and heated continuously for 48 hours in a forced ventilation oven set at 140°C (i.e., a heat resistance test was conducted).

[0041] (4) After removing the product from the oven and allowing it to cool, use a spectrophotometer (e.g., Nippon Denshoku Co., Ltd. ZE-2000) to measure the color difference of the DOP paste as the "b value of the heated paste".

[0042] (5) Calculate the hue change rate bw before and after heating from the above-obtained "b value of the paste before heating" and "b value of the paste after heating" (bw = (b value of the paste after heating / b value of the paste before heating)).

[0043] Furthermore, the surface-treated calcium carbonate filler of the present invention is preferably a substance that, in addition to satisfying the above formulas (a) to (c), also satisfies one or more of the following formulas (e), (f) and (g), and more preferably a substance that also satisfies all of formulas (e), (f) and (g).

[0044] (e) The 50% diameter accumulated from the smallest particle side in the volumetric particle size distribution (D50) The surface-treated calcium carbonate filler of the present invention preferably has a cumulative diameter (D50; μm) of 50% from the small particle side in the volumetric particle size distribution measured by a laser diffraction particle size distribution measuring device, which meets the specified range. In the present invention, the D50 of the surface-treated calcium carbonate filler is preferably 0.10 ≤ D50 ≤ 2.00 (μm), more preferably 0.30 ≤ D50 ≤ 0.80 (μm). Although surface-treated calcium carbonate particles with a D50 of less than 0.10 (μm) can be obtained technically, there are concerns about increased manufacturing costs due to the need for more advanced and precise technology. If the D50 is greater than 2.00 (μm), the cohesion of secondary particles composed of primary particle aggregates may increase, making it difficult to disperse sufficiently when mixed with resin, which can easily cause filter clogging.

[0045] (Method for determining D50) D50 can be measured, for example, using a laser diffraction particle size distribution measuring device (MT-3300EX II manufactured by MicrotracBEL Co., Ltd.), together with D10, D90 and Da described later, as follows.

[0046] (1) First, in a 100 mL beaker, mix and suspend about 0.3 g of the surface-treated calcium carbonate filler sample and 50 mL of medium.

[0047] (2) Then, the contents of the beaker are dispersed by irradiating the contents with ultrasonic waves at 300 μA for 1 minute using a chip-type ultrasonic disperser (e.g., US-300T manufactured by Nippon Seiki Co., Ltd.).

[0048] (3) Subsequently, the volume particle size distribution of surface-treated calcium carbonate particles in the sample was determined using a laser diffraction particle size distribution measuring device (MT-3300EX II manufactured by MicrotracBEL Co., Ltd.).

[0049] It should be noted that, as media that can be used in the above determinations, examples include methanol and ethanol, as well as combinations thereof.

[0050] D50 can be controlled by changing various conditions during the manufacture of the surface-treated calcium carbonate particles constituting the filler of the present invention. Various methods for dispersing calcium carbonate particles are known in the past, such as mechanical methods using ball mills, sand mills, impact mills, homogenizers, DYNO-MILLs, etc., to finely pulverize the particles and reduce D50. In the carbon dioxide reaction method of wet synthesis, Ostwald ripening, where the particles are grown to a certain size and dispersed, is a preferred method for controlling the particle size of calcium carbonate particles.

[0051] (f) Sharpness index of volumetric particle size distribution ((D90-D10) / D50) The surface-treated calcium carbonate filler of the present invention preferably has a sharpness index ((D90-D10) / D50) in the volumetric particle size distribution measured by a laser diffraction particle size distribution measuring device within a specified range. Here, D50 is as described above, D90 is the 90% diameter (μm) accumulated from the small particle side in the volumetric particle size distribution measured by the laser diffraction particle size distribution measuring device, D10 is the 10% diameter (μm) accumulated from the small particle side in the volumetric particle size distribution measured by the laser diffraction particle size distribution measuring device, and Da is the maximum particle size (μm) in the volumetric particle size distribution measured by the laser diffraction particle size distribution measuring device.

[0052] In this invention, the sharpness index ((D90-D10) / D50) of the surface-treated calcium carbonate filler is preferably 0.9 ≤ (D90-D10) / D50 ≤ 2.0, more preferably 1.0 ≤ (D90-D10) / D50 ≤ 1.5. Although it is technically possible to obtain surface-treated calcium carbonate fillers with a sharpness index less than 0.9, there is a concern about increased manufacturing costs due to the need for more advanced and precise techniques. If the sharpness index of the surface-treated calcium carbonate filler is greater than 2.0, the deviation in the size of the voids formed in the molded article (e.g., film) obtained by mixing the obtained surface-treated calcium carbonate filler with resin sometimes becomes larger, making it difficult to obtain a porous film with a uniform distribution of in-plane voids.

[0053] (Method for determining the sharpness index ((D90-D10) / D50)) The sharpness indices D10, D90, and Da can be measured, for example, using a laser diffraction particle size distribution measuring device (e.g., MicrotracBEL Co., Ltd. MT-3300EX II) described for the determination of D50, in the same manner as the determination of D50.

[0054] The sharpness index can be controlled by changing various conditions during the manufacture of the surface-treated calcium carbonate filler of the present invention. As a method to reduce the sharpness index of calcium carbonate particles (e.g., to sharpen the particle size distribution by reducing coarse and fine particles), mechanical methods such as ball mills, sand mills, impact mills, homogenizers, and DYNO-MILLs, or methods such as panning that utilize the difference in settling velocity in water due to particle size to separate fine and coarse particles can also be used. However, from the viewpoint that the sharpness index can be easily reduced by improving the uniformity of the particle size of calcium carbonate particles, Oswald curing is preferred.

[0055] (g) Maximum particle size (Da) in the volumetric particle size distribution The surface-treated calcium carbonate filler of the present invention preferably has a maximum particle size (Da) within a specified range in the volumetric particle size distribution measured using a laser diffraction particle size distribution measuring device. In the present invention, the Da of the surface-treated calcium carbonate filler is preferably Da≤5.0 (μm) (i.e., 0<Da≤5.0 (μm)), more preferably Da≤3.0 (μm) (i.e., 0<Da≤3.0 (μm)). If Da is greater than 5.0 μm, problems may occur, for example, such as: breakage may occur during film stretching of the obtained surface-treated calcium carbonate filler and resin composition, and the surface-treated calcium carbonate filler may become easy to detach; undesirable protrusions may form on the surface of the obtained resin molded article, reducing the slipability of the resin molded article.

[0056] (Method for determining Da) For example, a laser diffraction particle size distribution measuring device (e.g., MicrotracBEL Co., Ltd. MT-3300EX II) described for the determination of D50 can be used to perform the measurement in the same manner as the determination of D50 described above.

[0057] The maximum particle size (Da) can be controlled by changing various conditions during the manufacture of the surface-treated calcium carbonate filler of the present invention. As a method to reduce the maximum particle size (Da) in the volumetric particle size distribution, it is preferable to perform classification operations such as decantation using gravity or centrifugal force, buoyancy separation, etc., in the water slurry form for the purpose of removing impurities and coarse particles, or to remove them using sieves, filters, etc., or, in the powder form, to perform classification operations such as air classification, etc., to remove agglomerates generated due to drying.

[0058] (Surface-treated calcium carbonate filler that has undergone surface treatment with a surface treatment agent) As described above, the surface-treated calcium carbonate filler of the present invention satisfies all of formulas (a), (b), and (c), and at least one of formulas (d), (e), (f), and (g) as needed. This surface-treated calcium carbonate filler comprises surface-treated calcium carbonate particles that have been surface-treated with a surface-treatment agent, preferably composed of these surface-treated calcium carbonate particles as the main component.

[0059] Here, the term "surface treated" is used to indicate the "state" of the surface of the surface of the surface-treated calcium carbonate filler and / or surface-treated calcium carbonate particles. On the other hand, the term "surface treated / surface-treated" is used to indicate that untreated (i.e., untreated) calcium carbonate particles are provided for a process of modifying their surface (surface treatment).

[0060] The surface-treated calcium carbonate particles in this invention are obtained by surface-treating unmodified (before surface treatment) calcium carbonate particles with a surface treatment agent.

[0061] (Unmodified calcium carbonate particles) Here, from the viewpoint of degassing during resin mixing, the unmodified calcium carbonate particles are synthetic calcium carbonate particles (e.g., light / colloidal calcium carbonate) prepared by calcining natural gray dense limestone, rather than natural white sugar-crystalline limestone (heavy calcium carbonate) containing more fine particles. For synthetic calcium carbonate, it is possible to control the particle size uniformly, and hydrochloric acid-insoluble ores that are raw materials for relatively coarse particles are removed beforehand. As for the crystal forms of synthetic calcium carbonate, the three most unstable crystals in aqueous or thermodynamic systems—barite, metastable aragonite, and stable calcite—can be cited. From the perspective of good stability, a substance containing calcite crystals as the main component is preferred.

[0062] These unmodified calcium carbonate particles can be manufactured using a known carbon dioxide process, for example, by adding water to quicklime obtained from the calcination of dense gray limestone to form calcium hydroxide, which then reacts with the carbon dioxide produced during calcination. Alternatively, the desired calcium carbonate particles can be obtained by adjusting the calcium carbonate slurry obtained from the carbon dioxide process to have a desired BET specific surface area through Oswald slaking.

[0063] It should be noted that, as the main objective of the present invention, namely to further improve the weather resistance or heat resistance of the resin composition when blended with polyolefin resins, in order to obtain calcium carbonate particles with further improved crystallinity, a seeding method using calcium carbonate particles obtained by Oswald curing as seed particles and subjecting them to a carbonation reaction is preferred over a method of preparing desired calcium carbonate particles by Oswald curing.

[0064] In addition, for the purpose of further improving the uniformity of the synthesized calcium carbonate particles, the calcium carbonate particles can also be obtained by using a separation device such as a liquid phase cyclone separator to separate the light liquid (particle side) and the heavy liquid in an appropriate ratio for the water slurry used to obtain the synthesized calcium carbonate particles or the water slurry containing calcium hydroxide before manufacturing the synthesized calcium carbonate particles.

[0065] (Surface treatment agent) Surface treatment agents are substances used on unmodified calcium carbonate particles to improve the flowability of powders, enhance the alkali resistance or slip resistance of calcium carbonate, and improve the properties of calcium carbonate fillers. Examples of surface treatment agents include phosphorus compounds. Examples of phosphorus compounds include inorganic phosphoric acids, organic phosphoric acids, and combinations thereof.

[0066] Examples of inorganic phosphates include: orthophosphoric acid, phosphorous acid, phosphonic acid, pyrophosphoric acid, polyphosphoric acid (e.g., tripolyphosphoric acid) and condensed phosphoric acid, their salts (e.g., alkali metal salts such as sodium and potassium salts; alkaline earth metal salts such as magnesium salts; aluminum salts), and combinations thereof. Specific examples of salts of inorganic phosphates include: sodium phosphate, potassium phosphate, aluminum phosphate, sodium polyphosphate, sodium pyrophosphate, sodium tripolyphosphate, acidic sodium tripolyphosphate, sodium tetrapolyphosphate, sodium pentapolyphosphate, sodium metaphosphate, sodium hexametaphosphate, sodium metaphosphate, and sodium superphosphate, and combinations thereof.

[0067] Examples of organophosphoric acids include: hydroxyethylidene diphosphonic acid, hypozonyltrimethylenephosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, ethylenediaminetetramethylenephosphonic acid, and phenylphosphonic acid; and their salts; trimethyl phosphate, triethyl phosphate, tripropyl phosphate, monomethyl phosphate or dimethyl phosphate, dimethyl phenylphosphonate, diethyl phenylphosphonate, trimethyl phosphite (methyl phosphite), triethyl phosphite (ethyl phosphite), acidic phosphate esters, and combinations thereof.

[0068] For the aforementioned surface treatment agents, considering that they can effectively improve all the properties of the resulting resin composition, such as weather resistance, heat resistance, and strength, inorganic phosphoric acids such as sodium hexametaphosphate, sodium polyphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium superphosphate, as well as organic phosphoric acids such as triazinetrimethylenephosphonic acid and trimethyl phosphate, and combinations thereof, are preferably used as phosphoric acid compounds.

[0069] In this invention, the surface treatment agent may also contain other surface treatment agents besides the aforementioned phosphorus compounds.

[0070] Examples of other surface treatment agents include: fatty acid / fatty acid soap-based surface treatment agents, coupling agent-based surface treatment agents, and surfactant-based surface treatment agents, as well as combinations thereof. These other surface treatment agents may also be commercially available products.

[0071] Examples of fatty acid / fatty acid soap-based surface treatment agents include fatty acids and fatty acid salts, as well as combinations thereof.

[0072] Examples of fatty acids include saturated fatty acids, unsaturated fatty acids, alicyclic carboxylic acids and resin acids, and combinations thereof.

[0073] Examples of saturated fatty acids include: capric acid, hexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and isostearic acid, as well as combinations thereof. Examples of unsaturated fatty acids include: oleic acid, linoleic acid, and linolenic acid, as well as combinations thereof. Examples of alicyclic carboxylic acids include: cycloalkanoic acids with a carboxyl group at the end of a cyclopentane or cyclohexane ring. Examples of resin acids include: rosin acid, piratic acid, and neorosin acid, as well as combinations thereof.

[0074] Examples of fatty acid salts include: alkali metal salts (e.g., sodium and potassium salts), alkaline earth metal salts (e.g., calcium and magnesium salts), ammonium salts, and amine salts, as well as combinations thereof. Considering their high solubility in water and ease of surface treatment of calcium carbonate, alkali metal salts of fatty acids are preferred.

[0075] Examples of fatty acid salts include: saturated fatty acid salts such as potassium laurate, potassium myristate, potassium palmitate, sodium palmitate, potassium stearate, sodium stearate, and sodium isostearate; unsaturated fatty acid salts such as potassium oleate and sodium oleate; alicyclic carboxylates such as sodium naphthenate and lead cyclohexylbutyrate; potassium rosinate and sodium rosinate; and combinations thereof.

[0076] The aforementioned fatty acid / fatty acid soap-based surface treatment agents may also be modified or unmodified fatty acids derived from animals or plants. For example, they may be mixed fatty acids commonly used in this technical field, such as tallow fatty acids, palm oil fatty acids, palm kernel oil fatty acids, soybean oil fatty acids, etc.; their alkali metal salts; or so-called hydrogenated mixed fatty acids or their alkali metal salts that have been hydrogenated to reduce the unsaturation of these mixed fatty acids.

[0077] It should be noted that when using fatty acids directly as fatty acids, from the perspective of being able to achieve a more uniform surface treatment of unmodified calcium carbonate particles, it is preferable to pre-dissolve them in hot water heated to above the melting point of the fatty acid used, add an appropriate amount of known emulsifiers such as anionic surfactants or nonionic surfactants, emulsify the fatty acid using a homogenizer or other emulsifying and dispersing machine, and then add it to the aforementioned unmodified calcium carbonate.

[0078] Furthermore, among the aforementioned fatty acids, unsaturated fatty acids, due to their high solubility in water and low melting point, facilitate more uniform surface treatment of unmodified calcium carbonate particles. On the other hand, from a heat resistance perspective, unsaturated fatty acids are prone to thermal degradation due to the presence of unsaturated double bonds. Therefore, in this invention, considering the need to completely eliminate concerns about thermal degradation from unsaturated fatty acids, the fatty acids are preferably saturated fatty acids and / or saturated fatty acid salts. Alternatively, the total amount of saturated fatty acids and saturated fatty acid salts relative to the total mass of the fatty acids is preferably 90% by mass or more, more preferably 100% by mass.

[0079] Examples of surface treatments using coupling agents include: vinyl silane coupling agents, amino silane coupling agents, phenyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, acryloyl silane coupling agents, methacryl silane coupling agents, isocyanurate silane coupling agents, ureoyl silane coupling agents, mercaptosilane coupling agents, and isocyanate silane coupling agents, as well as combinations thereof. Vinyl silane coupling agents are preferred for the reason that they impart good strength to the resulting resin composition, while phenyl silane coupling agents are preferred for the reason that they impart good weather resistance or heat resistance to the resulting resin composition.

[0080] Examples of surfactant-based surface treatment agents include: aromatic sulfonic acids and / or resin acids and their salts or esters; alcohol surfactants; polyols; sorbitol fatty acid esters; amide surfactants; amine surfactants; polyoxyethylene alkyl ethers; polyoxyethylene nonylphenyl ethers; sodium α-olefin sulfonate; long-chain alkyl amino acids; amine oxides; alkylamines; and quaternary ammonium salts; and combinations thereof.

[0081] If good compatibility and dispersibility with the resin are considered when the obtained surface-treated calcium carbonate filler is blended with the resin, then other surface treatment agents are preferably fatty acid / fatty acid soap-based surface treatment agents, more preferably saturated fatty acids and unsaturated fatty acids, and their salts, and most preferably saturated fatty acid salts.

[0082] (Surface treatment of unmodified calcium carbonate particles) The surface treatment of unmodified calcium carbonate particles using the above-mentioned surface treatment agent is carried out, for example, in the following manner.

[0083] The surface treatment of unmodified calcium carbonate particles can be performed using either a conventional dry treatment or a wet treatment. Preferably, the surface treatment agent is added to an aqueous slurry containing the unmodified calcium carbonate particles. This method, commonly referred to as wet treatment, is preferred in that it appropriately balances the degree of surface treatment with manufacturing efficiency for the calcium carbonate particles.

[0084] The amount of surface treatment agent used, especially phosphorus compounds, varies depending on the BET specific surface area and / or amount of unmodified calcium carbonate particles, the phosphorus content contained in the phosphate itself, the type of resin to be finally compounded, or the compounding conditions, and is therefore not particularly limited. It can be appropriately selected by those skilled in the art in a manner that satisfies the above-mentioned Pw range.

[0085] For unmodified calcium carbonate particles, there is no particular limitation on the treatment order of the aforementioned surface treatment agents, especially phosphorus-based compounds and other surface treatment agents. For example, the unmodified calcium carbonate particles can be treated with other surface treatment agents first, followed by treatment with a phosphorus-based compound. Alternatively, the unmodified calcium carbonate particles can be treated with a phosphorus-based compound first, followed by treatment with other surface treatment agents. Or, phosphorus-based compounds and other surface treatment agents can be used together, i.e., simultaneously, to treat the unmodified calcium carbonate particles.

[0086] There are no particular limitations on the temperature used for surface treatment; a suitable temperature can be selected by those skilled in the art.

[0087] After the above surface treatment, the resulting particles can be powdered by any operation such as dehydration, drying, and pulverization, according to conventional methods.

[0088] It should be noted that filter presses or centrifugal dewatering machines can be used to dewater slurries containing surface-treated calcium carbonate particles. For drying, hot air dryers such as micron dryers, which can efficiently dry by directly contacting the surface-treated calcium carbonate particles with high-temperature hot air, can be used, or heat transfer dryers such as CD dryers, which indirectly dry the surface-treated calcium carbonate particles by contacting a heating plate.

[0089] Thus, surface-treated calcium carbonate particles that have undergone surface treatment with a surface treatment agent can be obtained. These surface-treated calcium carbonate particles can be directly used as surface-treated calcium carbonate fillers that satisfy all of the above formulas (a), (b), and (c), and at least one of formulas (d), (e), (f), and (g) as needed.

[0090] 2. Resin composition Next, the resin composition of the present invention will be described.

[0091] The resin composition of the present invention contains a resin and the above-mentioned surface-treated calcium carbonate filler.

[0092] The resin contained in the resin composition is not particularly limited, and examples include: polyolefin resins, polystyrene resins, acrylic resins, methacrylic resins, vinyl chloride resins, vinylidene chloride resins, polyamide resins, polyether resins, vinyl acetate resins, and polyvinyl alcohol resins, as well as combinations thereof. Specific examples of polyolefin resins include: low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (L-LDPE), ultra-high molecular weight polyethylene (UHMWPE), and other polyethylene resins or polypropylene resins, ethylene-propylene copolymers, copolymers of ethylene or propylene with other monomers, etc. The resin may also be petroleum-derived, plant-derived (e.g., bioplastics), or combinations thereof. In this invention, considering that the molding temperature is lower than that of engineering plastics and that it has sufficient heat resistance at temperatures where the surface-treated calcium carbonate particles can exhibit heat resistance, the resin is preferably a polyolefin resin.

[0093] The content of surface-treated calcium carbonate filler in the resin composition varies depending on the type of resin used, the intended use of the resulting resin composition, and the desired physical properties, and is therefore not necessarily limited. For example, it is 0.05 to 100 parts by weight relative to 100 parts by weight of resin, preferably 50 to 100 parts by weight, and more preferably 70 to 100 parts by weight. If the content of surface-treated calcium carbonate filler in the resin composition exceeds 100 parts by weight (i.e., greater than the resin content), a decrease in hue (whiteness) may sometimes occur due to reduced compatibility with the resin or resin deterioration. If the content of surface-treated calcium carbonate filler in the resin composition is less than 0.05 parts by weight, the resulting resin composition may sometimes lack sufficient heat resistance.

[0094] It should be noted that, as other additives, the resin composition of the present invention may also contain lubricants such as fatty acids, fatty amides, ethylene bis-stearamide, and dehydrated sorbitol fatty acid esters; plasticizers; stabilizers such as heat stabilizers and light stabilizers; antioxidants; ultraviolet absorbers; neutralizers; antifogging agents; antiblocking agents; antistatic agents; lubricants; and colorants; as well as combinations thereof. The content of other additives is not particularly limited, and those skilled in the art can select appropriate amounts without hindering the effects produced by the surface-treated calcium carbonate filler described above.

[0095] The resin, surface-treated calcium carbonate filler, and other additives as needed can be mixed using known mixers such as high-speed mixers, Henschel mixers, drum mixers, and belt blenders. After mixing the resin composition in the mixer, it can be heated and kneaded using a single-screw or twin-screw extruder, a kneading mixer, a Banbury mixer, etc., temporarily processed into granules as a masterbatch, and then melted and formed into a film using known forming machines such as T-die extrusion or blow molding.

[0096] 3. Molded products The molded article of the present invention is composed of the above-described resin composition.

[0097] The molded article of the present invention preferably has a film morphology.

[0098] For example, after forming a sheet from the resin composition obtained by mixing as described above using a T-die or similar method, uniaxial or biaxial stretching can be performed to obtain a porous film with fine pores on the surface. Alternatively, after the above mixing, a film can be formed using a known forming machine such as a T-die extruder or blow molding, and then acid-treated to dissolve the aforementioned surface-treated calcium carbonate filler present inside, thereby obtaining a porous film with fine pores on the surface. Furthermore, multiple T-die extruders from the above steps can be stacked as needed, or a multilayer film can be formed by stretching and bonding. In addition, for the purpose of imparting printability to the film, surface treatment such as plasma discharge can be performed on the film surface, and an ink receiving layer can be coated. Example

[0099] The present invention will now be described in detail with reference to specific embodiments, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise specified, % refers to mass, and parts refers to parts by mass in the following description.

[0100] The materials, surface-treated calcium carbonate fillers, and particles described in the various embodiments and comparative examples were evaluated in the following manner.

[0101] (1) BET specific surface area of ​​unmodified calcium carbonate Approximately 300 mg of unmodified calcium carbonate particles used in each example and comparative example were placed in a measuring apparatus (Macsorb HM model-1201 manufactured by Mounttech Corporation). After pretreatment by heating at 200°C for 10 minutes in a nitrogen and helium mixed atmosphere, low-temperature, low-humidity physical adsorption was performed in a liquid nitrogen environment. The BET specific surface area (m²) of the unmodified calcium carbonate particles was then measured. 2 / g).

[0102] (2) BET specific surface area (Sw) of surface-treated calcium carbonate filler Approximately 300 mg of the surface-treated calcium carbonate filler obtained in each embodiment and comparative example was placed in a measuring apparatus (Macsorb HM model-1201 manufactured by Mounttech Corporation). After pretreatment by heating at 200°C for 10 minutes in a nitrogen and helium mixed atmosphere, low-temperature, low-humidity physical adsorption was performed in a liquid nitrogen environment. The BET specific surface area (m²) of the surface-treated calcium carbonate particles constituting the filler was then measured. 2 / g).

[0103] (3) The phosphorus content (Pw) of the surface-treated calcium carbonate filler was measured using an inductively coupled plasma (ICP) emission spectrometer. Approximately 1000 mg of the surface-treated calcium carbonate filler obtained in the various examples and comparative examples was placed in a crucible and calcined at 300°C for 3 hours in an electric furnace. After calcination, a small amount of distilled water and 7.5 mL of 1.38 equivalent nitric acid (nitric acid (1.38) for the determination of hazardous metals, manufactured by Fujifilm and Koko Pure Chemical Industries Co., Ltd.) were added to a 200 mL beaker containing the mixture, and the mixture was boiled and slowly cooled using an electric furnace. The slowly cooled mixture was added to a 100 mL volumetric flask containing 100 μL of yttrium standard solution (Y1000 manufactured by Fujifilm and Koko Pure Chemical Industries Co., Ltd.), and then diluted to 100 mL with distilled water. The solution was then filtered through 5°C filter paper, and the resulting filtrate was used to prepare a sample for ICP determination. Subsequently, the phosphorus content (ppm) in the sample was determined using an inductively coupled plasma (ICP) emission spectrometer (SII NanoTechnology Co., Ltd. ICP emission spectrometer SPS3500).

[0104] (4) Weight loss (Tw) of surface-treated calcium carbonate filler at 140℃~220℃ Approximately 30 mg of the surface-treated calcium carbonate filler obtained in each example and comparative example was weighed into a platinum sample pan and placed in a differential thermal balance (Shimadzu Corporation DTG-60A). The temperature of the measuring apparatus was then increased from room temperature to 550°C at a rate of 30°C / min, and the weight loss (mass%) per 1 g of surface-treated calcium carbonate filler from 140°C to 220°C was calculated.

[0105] (5) Color change rate (bw) of surface-treated calcium carbonate filler The surface-treated calcium carbonate filler and dioctyl phthalate (DOP) obtained in the examples and comparative examples were weighed at a mass ratio of 3:7 and mixed using a degassing mixer (Mazerustar, manufactured by Kurashiki Spinning Co., Ltd.) to prepare a DOP paste. The color difference of this DOP paste was then measured using a spectrophotometer (ZE-2000, manufactured by Nippon Denshoku Co., Ltd.) as the "b-value of the paste before heating". Subsequently, the DOP paste was placed in a glass petri dish and continuously heated in a forced-ventilation oven set to 140°C for 48 hours. The DOP paste was removed from the oven and allowed to cool. The color difference of the DOP paste was then measured using the aforementioned spectrophotometer as the "b-value of the paste after heating".

[0106] Based on the obtained "b-value of the paste before heating" and "b-value of the paste after heating", the hue change rate bw before and after heating is calculated according to the following formula: bw = (b value of the paste after heating / b value of the paste before heating).

[0107] (6) The D50, sharpness index ((D90-D10) / D50) and Da of the surface-treated calcium carbonate filler Approximately 0.3 g of the surface-treated calcium carbonate filler obtained in each example and comparative example and 50 mL of methanol were added to a 100 mL beaker. The contents of the beaker were then dispersed by irradiation with ultrasound at 300 μA for 60 seconds using, for example, an ultrasonic disperser US-300T manufactured by Nippon Seiki Co., Ltd., to obtain a sample. Subsequently, the volumetric particle size distribution of the surface-treated calcium carbonate particles in the sample was measured using a laser diffraction particle size distribution measuring device (MT-3300EX II manufactured by MicrotracBEL Co., Ltd.). Based on the obtained volumetric particle size distribution results, the values ​​of D50, D10, D90, and Da, as well as the sharpness index ((D90 - D10) / D50) calculated using these values, were obtained.

[0108] (7) Thermal oxidation stability of particles Using a G-12 benchtop hot press manufactured by Orihara Manufacturing Co., Ltd., set to 200°C, 50×50×1 mm test pieces were prepared from the granules obtained in the various examples and comparative examples. For these test pieces, based on Japanese Industrial Standard JIS K7368 (Plastics - Polypropylene and Propylene Copolymers - Determination of Thermal Oxidative Stability in Air - Oven Method), the test pieces were heated in air at a set temperature of 140°C using a forced-ventilation oven to promote degradation. The number of days required from the start of the test until local cracks, collapse, and / or discoloration could be visually observed was recorded, and the results were evaluated according to the following criteria.

[0109] A: Even after 10 days, there was no significant change.

[0110] B: The color change was confirmed after 10 days.

[0111] C: Discoloration and cracks were confirmed after 10 days.

[0112] D: Discoloration and cracks have been confirmed after 5 days.

[0113] (8) Evaluation of the heat resistance of particles For the particles obtained in each embodiment and comparative example, each particle was heated in air for 10 days using a forced-ventilation oven at 140°C to promote degradation. For the obtained heat-degraded particles and the particles in their initial state (without heat degradation), the MFR value (g / 10 min) was measured using a MELT INDEXER F-F01 manufactured by Toyo Seiki Co., Ltd., based on Japanese Industrial Standard JIS K7210 (Test Methods for Melt Flow Rate (MFR) and Melt Volumetric Flow Rate (MVR) of Plastics—Thermoplastics), at a test temperature of 230°C and a rated load of 21.6 kg. Furthermore, based on the results, the rate of change of MFR (%) was calculated according to the following formula to evaluate the presence or absence of heat resistance.

[0114]

Number 1

[0115] (7) Evaluation of particle dispersibility In a twin-shaft mixer (Toyo Seiki Co., Ltd. 2D25W) equipped with a three-piece filter consisting of 100 μm, 60 μm and 400 μm mesh, the granules obtained in each example and comparative example were mixed and extruded at a barrel set temperature of 170°C, a screw speed of 150 rpm and a feed rate of 6 kg / h. The resin pressure was measured after 60 minutes, and the dispersibility was evaluated according to the following criteria.

[0116] A: The resin pressure after 60 minutes of mixing is less than 4 MPa.

[0117] B: The resin pressure after 60 minutes of mixing is above 4 MPa and less than 6 MPa.

[0118] C: The resin pressure after 60 minutes of mixing is above 6 MPa and less than 8 MPa.

[0119] D: The resin pressure after 60 minutes of mixing is above 8 MPa, or it sprays out due to filter blockage before passing through.

[0120] (8) Evaluation of tensile strength For the particles obtained in the various embodiments and comparative examples, a film with a thickness of 200 μm was prepared using a benchtop hot press G-12 manufactured by Orihara Manufacturing Co., Ltd., set to 200°C. Using a stamping die, 20 dumbbell-shaped test pieces were stamped from the film, and the thickness of each test piece was measured. Five test pieces with a film thickness within ±10% of the average film thickness of the 20 pieces were selected. For the selected test pieces, tensile strength was evaluated based on Japanese Industrial Standard JIS K7127 (Plastics - Test methods for tensile properties - Part 3) using an AUTOGRAPH AG-I manufactured by Shimadzu Corporation, with a test force of 500 N and a test speed of 5 mm / min. Dispersion was evaluated according to the following criteria. It should be noted that the tensile strength referred to here is the stress measured at the point of fracture of the test piece.

[0121] A: Tensile strength is above 33 MPa.

[0122] B: Tensile strength is above 30 MPa and less than 33 MPa.

[0123] C: Tensile strength is above 27 MPa and less than 30 MPa.

[0124] D: Tensile strength less than 27 MPa.

[0125] (9) Evaluation of sliding properties: Determination of static and dynamic friction coefficients For the particles obtained in the various embodiments and comparative examples, test pieces of 80×200×1 mm were prepared using a benchtop hot press G-12 manufactured by Orihara Seisakusho Co., Ltd., set to 200°C. For these test pieces, the static and dynamic coefficients of friction were measured using a coefficient of friction measuring machine AN-S2 manufactured by Toyo Seiki Co., Ltd., based on Japanese Industrial Standard JIS K7125 (Plastics—Films and Sheets—Test Method for Coefficient of Friction), with a load of 200 g and a test speed of 100 mm / min. The sliding properties were evaluated according to the following criteria. It should be noted that low values ​​for both the static and dynamic coefficients of friction indicate high sliding properties.

[0126] (Evaluation of static friction coefficient) A: The static friction coefficient is less than 0.60. B: The static friction coefficient is greater than 0.60 and less than 0.70. C: The static friction coefficient is below 0.70 and less than 0.80. D: The static friction coefficient is above 0.80.

[0127] (Evaluation of dynamic and static friction coefficients) A: The coefficient of kinetic friction is less than 0.40. B: The coefficient of kinetic friction is greater than 0.40 and less than 0.50. C: The coefficient of kinetic friction is below 0.50 and less than 0.60. D: The coefficient of kinetic friction is above 0.60.

[0128] (Comprehensive evaluation of sliding performance) A: Excellent sliding properties. B: Good sliding properties. C: Slightly better sliding properties. D: Poor slippage.

[0129] (Example 1: Preparation of surface-treated calcium carbonate filler (E1)) Using natural gas as a heat source, quicklime is obtained by calcining gray, dense limestone in a calcining furnace. The quicklime is then dissolved in water to obtain a calcium hydroxide slurry with a specific gravity adjusted to 1.050. By reacting this calcium hydroxide slurry with CO2 gas discharged from the calcining furnace, a synthetic calcium carbonate slurry with a concentration of 8.0% by mass is obtained.

[0130] The resulting synthetic calcium carbonate slurry was subjected to Oswald curing to produce particles with a BET specific surface area of ​​10.0 m². 2 After / g, the obtained calcium carbonate was used as a seed crystal, and calcium hydroxide at 10% by mass relative to the calcium carbonate solids was added to react with CO2 gas discharged from the calcination furnace to obtain a BET specific surface area of ​​8.0 m². 2 / g of calcium carbonate slurry.

[0131] To this end, an aqueous solution of a phosphorus-based compound was added to the calcium carbonate slurry. The aqueous solution of the phosphorus-based compound was prepared by dissolving sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at 0.6% by mass relative to the solid content of calcium carbonate in warm water to a concentration of 10% by mass. The mixture was stirred at 60°C for 12 hours, dehydrated using a filter press to a solid content of 65% by mass, dried using a hot air dryer (Hosokawa Micron Co., Ltd. Drymeister DMR-1 dryer), subjected to impact crushing, and classified using an air classifier to obtain the surface-treated calcium carbonate filler (E1) for polyolefin resin of Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (E1) are shown in Table 1.

[0132] (Example 2: Preparation of surface-treated calcium carbonate filler (E2)) Instead of the aqueous solution of the phosphorus compound prepared in Example 1, an aqueous solution of the phosphorus compound prepared by means of aluminum dihydrogen phosphate (a 50% aluminum dihydrogen phosphate solution manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 1.0% by mass relative to the solid fraction of calcium carbonate was added to the calcium carbonate slurry. A fatty acid salt prepared by saponification of saturated fatty acid (NAA-122 (lauric acid: 99%) manufactured by Nippon Oil Co., Ltd.) with caustic soda at a concentration of 1.6% by mass relative to the solid fraction of calcium carbonate was also added to the slurry. Otherwise, surface-treated calcium carbonate filler (E2) was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (E2) are shown in Table 1.

[0133] (Example 3: Preparation of surface-treated calcium carbonate filler (E3)) Instead of the aqueous solution of the phosphorus compound prepared in Example 1, an aqueous solution of the phosphorus compound prepared by means of sodium pyrophosphate (manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 0.3% by mass relative to the solid fraction of calcium carbonate was added to the calcium carbonate slurry. A substance prepared by means of saturated fatty acid soap (manufactured by Nippon Oil Co., Ltd., NONSOUL SN-1 (100% saturated fatty acid content)) at a concentration of 2.2% by mass relative to the solid fraction of calcium carbonate was used to achieve a concentration of 10% by mass in warm water. Otherwise, surface-treated calcium carbonate filler (E3) was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (E3) are shown in Table 1.

[0134] It should be noted that the NONSOUL SN-1 manufactured by Nippon Oil Co., Ltd. used above has the following composition (myristic acid 3% by mass, palmitic acid 27% by mass, stearic acid 66% by mass and other 4% by mass).

[0135] (Example 4: Preparation of surface-treated calcium carbonate filler (E4)) Instead of the aqueous solution of the phosphorus compound prepared in Example 3, an aqueous solution of a phosphorus compound prepared in a manner that makes orthophosphoric acid (75% orthophosphoric acid manufactured by RASA Kogyo Co., Ltd.) at a concentration of 1.5% by mass relative to the solid fraction of calcium carbonate to a concentration of 10% by mass in warm water was used. Otherwise, surface-treated calcium carbonate filler (E4) was obtained in the same manner as in Example 3. The physical properties of the obtained surface-treated calcium carbonate (E4) are shown in Table 1.

[0136] (Example 5: Preparation of surface-treated calcium carbonate filler (E5)) Instead of the aqueous solution of the phosphorus compound prepared in Example 3, an aqueous solution of the phosphorus compound was prepared in warm water in a manner that made sodium hexametaphosphate (manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 0.6% by mass relative to the solid fraction of calcium carbonate to a concentration of 10% by mass. Otherwise, the surface-treated calcium carbonate filler (E5) was obtained in the same manner as in Example 3. The physical properties of the obtained surface-treated calcium carbonate filler (E5) are shown in Table 1.

[0137] (Example 6: Preparation of surface-treated calcium carbonate filler (E6)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing to achieve a BET specific surface area of ​​13.0 m², in the same manner as in Example 1. 2 / g, to obtain calcium carbonate slurry.

[0138] Using this calcium carbonate slurry, and instead of the aqueous solution of the phosphorus compound prepared in Example 1, an aqueous solution of the phosphorus compound was prepared in warm water to a concentration of 10% by mass of 0.3% by mass of triazinetrimethylenephosphonic acid (JPCN-300 manufactured by Jōhoku Chemical Co., Ltd.) relative to the solid fraction of calcium carbonate. A CD dryer manufactured by Kurimoto Iron Works Co., Ltd. was used as a heat transfer dryer, and the solution was dried at a vapor pressure of 0.25 MPa for 2 hours. Otherwise, surface-treated calcium carbonate filler (E6) was obtained in the same manner as in Example 2. The physical properties of the obtained surface-treated calcium carbonate filler (E6) are shown in Table 1.

[0139] (Example 7: Preparation of surface-treated calcium carbonate filler (E7)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing to achieve a BET specific surface area of ​​10.0 m², in the same manner as in Example 1. 2 After / g, particles were grown to a BET specific surface area of ​​8.0m² through seed crystal synthesis. 2 / g, to obtain calcium carbonate slurry.

[0140] For this calcium carbonate slurry, an aqueous solution of phosphorus compounds was prepared by dissolving sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 0.6% by mass relative to the solid content of calcium carbonate in warm water to a concentration of 10% by mass. The solution was stirred at 60°C for 12 hours, dehydrated by a filter press to a solid content of 65% by mass, dried using a hot air dryer (Hosokawa Micron Co., Ltd. Drymeister DMR-1 dryer), and then subjected to impact crushing to obtain phosphorus compound-treated calcium carbonate powder.

[0141] The obtained phosphorus-based compound-treated calcium carbonate powder was fed into a high-speed mixer SMV(G)-100 manufactured by KAWATA Corporation. While stirring, glycerol (refined glycerol manufactured by Miyoshi Oils & Fats Co., Ltd.) as a polyol was added at 0.6% by mass relative to the solid fraction of calcium carbonate as a surface treatment agent. The mixture was dry-treated at 110°C for 0.5 hours, followed by impact crushing. The resulting powder was then classified using an air classifier to obtain surface-treated calcium carbonate filler (E7). The physical properties of the obtained surface-treated calcium carbonate filler (E7) are shown in Table 1.

[0142] (Example 8: Preparation of surface-treated calcium carbonate filler (E8)) Instead of the surface treatment agent used in Example 7, a vinyl silane coupling agent (Shin-Etsu Chemical Co., Ltd. KBM-1003) at 1.0% by mass relative to the solid fraction of calcium carbonate was used as the surface treatment agent, and the surface-treated calcium carbonate filler (E8) was obtained in the same manner as in Example 7. The physical properties of the obtained surface-treated calcium carbonate filler (E8) are shown in Table 1.

[0143] (Example 9: Preparation of surface-treated calcium carbonate filler (E9)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing in the same manner as in Example 1, resulting in particle growth to a BET specific surface area of ​​4.0 m². 2 After / g, the obtained calcium carbonate was used as a seed crystal, and calcium hydroxide at 10% by mass relative to the calcium carbonate solids was added to react with CO2 gas discharged from the calcination furnace to obtain a BET specific surface area of ​​2.8m². 2 / g of calcium carbonate slurry was then used to obtain calcium carbonate powder treated with phosphorus compounds in the same manner as in Example 7.

[0144] The surface treatment agent used in Example 7 was replaced with a saturated fatty acid (Sakura beaded stearic acid manufactured by Nippon Oil Co., Ltd.) at 1.0% by mass relative to the solid fraction of calcium carbonate. Otherwise, the surface-treated calcium carbonate filler (E9) was obtained in the same manner as in Example 7. The physical properties of the obtained surface-treated calcium carbonate filler (E9) are shown in Table 1.

[0145] It should be noted that the beaded stearic acid Sakura manufactured by Nippon Oil Co., Ltd. used above has the following composition (myristic acid 4% by mass, palmitic acid 30% by mass, stearic acid 65% by mass and others 1% by mass).

[0146] (Example 10: Preparation of surface-treated calcium carbonate filler (E10)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing in the same manner as in Example 1, resulting in particle growth to a BET specific surface area of ​​20.0 m². 2 After / g, the obtained calcium carbonate was used as a seed crystal, and calcium hydroxide at 10% by mass relative to the calcium carbonate solids was added to react with CO2 gas discharged from the calcination furnace to obtain a BET specific surface area of ​​17.0 m². 2 / g of calcium carbonate slurry.

[0147] For this calcium carbonate slurry, an aqueous solution of a phosphorus compound was prepared by adding sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 3.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. A fatty acid salt obtained by saponifying a saturated fatty acid (NAA-122 (lauric acid: 99%) manufactured by Nippon Oil Co., Ltd.) at a concentration of 2.7% by mass relative to the solid fraction of calcium carbonate with caustic soda was added to the solution, and the resulting solution was prepared by adding a fatty acid salt at a concentration of 10% by mass relative to the solid fraction of calcium carbonate with caustic soda. Otherwise, surface-treated calcium carbonate filler (E10) was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (E10) are shown in Table 1.

[0148] (Example 11: Preparation of surface-treated calcium carbonate filler (E11)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing to achieve a BET specific surface area of ​​24.0 m², in the same manner as in Example 1. 2 After / g, the obtained calcium carbonate was used as a seed crystal, and calcium hydroxide at 10% by mass relative to the calcium carbonate solids was added to react with CO2 gas discharged from the calcination furnace to obtain a BET specific surface area of ​​20.0 m². 2 / g of calcium carbonate slurry.

[0149] For this calcium carbonate slurry, an aqueous solution of a phosphorus compound was prepared by adding sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 4.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. A fatty acid salt prepared by saponifying a saturated fatty acid (NAA-122 (lauric acid: 99%) manufactured by Nippon Oil Co., Ltd.) at a concentration of 3.4% by mass relative to the solid fraction of calcium carbonate with caustic soda was added to the solution, and the resulting solution was prepared by adding a fatty acid salt at a concentration of 10% by mass relative to the solid fraction of calcium carbonate with caustic soda. Otherwise, surface-treated calcium carbonate filler (E11) was obtained in the same manner as in Example 11. The physical properties of the obtained surface-treated calcium carbonate filler (E11) are shown in Table 1.

[0150] [Table 1] .

[0151] (Comparative Example 1: Preparation of surface-treated calcium carbonate filler (C1)) While using the SMV(G)-100 high-speed mixer manufactured by KAWATA Corporation, the BET specific surface area is 1.9m². 2 The mixture was prepared by stirring heavy calcium carbonate (Super S, manufactured by Maruo Calcium Co., Ltd.) and adding sodium superphosphate (Ultraporine, manufactured by Taihei Chemical Industry Co., Ltd.) in warm water to a concentration of 10% by mass relative to the solid fraction of calcium carbonate. Then, saturated fatty acid (Sakura beaded stearic acid, manufactured by Nippon Oil Co., Ltd., 100% saturated fatty acid content) was added as a surface treatment agent at 1.0% by mass relative to the solid fraction of calcium carbonate. The mixture was stirred at 110°C for 0.5 hours to obtain surface-treated calcium carbonate filler (C1). The physical properties of the obtained surface-treated calcium carbonate filler (C1) are shown in Table 2.

[0152] (Comparative Example 2: Preparation of surface-treated calcium carbonate filler (C2)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing in the same manner as in Example 1, resulting in particle growth to a BET specific surface area of ​​30.0 m². 2 After / g, the obtained calcium carbonate was used as a seed crystal, and calcium hydroxide at 10% by mass relative to the calcium carbonate solids was added to react with CO2 gas discharged from the calcination furnace to obtain a BET specific surface area of ​​25.0 m². 2 / g of calcium carbonate slurry.

[0153] For this calcium carbonate slurry, an aqueous solution of a phosphorus compound was prepared by adding sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 1.2% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. The resulting substance was then added to this solution by adding saturated fatty acid soap (NONSOUL SN-1 (100% saturated fatty acid content) manufactured by Nippon Oil Co., Ltd.) at a concentration of 4.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. Otherwise, surface-treated calcium carbonate filler (C2) was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (C2) are shown in Table 2.

[0154] (Comparative Example 3: Preparation of surface-treated calcium carbonate filler (C3)) Surface-treated calcium carbonate filler (C3) was obtained in the same manner as in Example 3, except that no phosphorus compounds were added. The physical properties of the obtained surface-treated calcium carbonate filler (C3) are shown in Table 2.

[0155] (Comparative Example 4: Preparation of surface-treated calcium carbonate filler (C4)) Instead of the aqueous solution prepared in Example 3, an aqueous solution of a phosphorus compound prepared in warm water to make sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 5.0% by mass relative to the calcium carbonate solid fraction to a concentration of 10% by mass was used. Otherwise, the surface-treated calcium carbonate filler (C4) was obtained in the same manner as in Example 3. The physical properties of the obtained surface-treated calcium carbonate filler (C4) are shown in Table 2.

[0156] (Comparative Example 5: Preparation of surface-treated calcium carbonate filler (C5)) In the same manner as in Example 1, the resulting synthetic calcium carbonate slurry was subjected to Oswald curing to grow particles to a BET specific surface area of ​​19.5 m². 2 / g, thus obtaining calcium carbonate slurry.

[0157] For this calcium carbonate slurry, an aqueous solution of a phosphorus compound was prepared by adding sodium superphosphate (Ultraporine manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 1.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. A substance prepared by adding saturated fatty acid soap (NONSOUL SN-1 manufactured by Nippon Oil Co., Ltd.) at a concentration of 4.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass was obtained. Otherwise, a surface-treated calcium carbonate filler (C5) for resin was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (C5) are shown in Table 2.

[0158] The physical properties of the obtained surface-treated calcium carbonate filler (C4) are shown in Table 2.

[0159] (Comparative Example 6: Preparation of surface-treated calcium carbonate filler (C6)) The resulting synthetic calcium carbonate slurry was subjected to Oswald curing to achieve a BET specific surface area of ​​16.0 m², in the same manner as in Example 1. 2 / g, to obtain a calcium carbonate slurry with a concentration of 10.0% by mass.

[0160] For this calcium carbonate slurry, an aqueous solution of a phosphorus compound was prepared by adding sodium hexametaphosphate (manufactured by Taihei Chemical Industry Co., Ltd.) at a concentration of 1.67% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. The resulting substance was then added to the slurry by adding a saturated fatty acid soap (manufactured by Nippon Oil Co., Ltd., NONSOUL SN-1) at a concentration of 4.0% by mass relative to the solid fraction of calcium carbonate to warm water to a concentration of 10% by mass. The mixture was stirred at 80°C for 0.5 hours. Otherwise, surface-treated calcium carbonate filler (C6) was obtained in the same manner as in Example 1. The physical properties of the obtained surface-treated calcium carbonate filler (C6) are shown in Table 2.

[0161] [Table 2] .

[0162] (Examples 12-22 and Comparative Examples 7-12: Preparation of Particles (PE1)-(PE11) and (PC1)-(PC6)) A resin mixture was prepared by mixing 30 parts by weight of surface-treated calcium carbonate (E1) to (E11) and (C1) to (C6) prepared in Examples 1 to 11 and Comparative Examples 1 to 6, 70 parts by weight of polypropylene resin (NOVATEC PP FB3B manufactured by Polypropylene Co., Ltd., MFR: 7.5 g / 10 min) and 1.0 part by weight of phenolic antioxidant (Irganox 1010 manufactured by BASF JAPAN Co., Ltd.). 10 kg of the resin mixture was passed through a TEX25αIII twin-shaft mixer manufactured by Japan Steel Works (JSW) equipped with a filter with a mesh size of 100 μm. After melt mixing at a barrel set temperature of 170°C, a screw speed of 250 rpm, and a feed rate of 8 kg / h, the mixture was cut by a cold granulator manufactured by Inoue Manufacturing Co., Ltd., thereby producing granules (PE1) to (PE11) and (PC1) to (PC6). The results of the application evaluation of the obtained particles (PE1) to (PE11) and (PC1) to (PC6) are shown in Tables 3 and 4.

[0163] (Comparative Example 13: Production of Particles (PC7)) When mixing surface-treated calcium carbonate filler, polypropylene resin, and phenolic antioxidant, 1.0 part by weight of phosphorus-based antioxidant (BASF JAPAN Co., Ltd. Irgafos 168) was further added. Otherwise, granules (PC7) were prepared in the same manner as in Comparative Example 9. The results of the application evaluation of the obtained granules (PC7) are shown in Table 4.

[0164] [Table 3] .

[0165] [Table 4] .

[0166] As shown in Tables 3 and 4, compared with the particles (PC1) to (PC7) of Comparative Examples 7 to 13, the particles (PE1) to (PE11) prepared in Examples 12 to 22 all exhibited excellent thermal oxidation stability and a significantly reduced MFR change rate. In addition, there were also significant differences between the two in terms of dispersibility and maximum stress (strength).

[0167] Therefore, it can be seen that, compared with the surface-treated calcium carbonate fillers (C1) to (C6) of Comparative Examples 1 to 6, the surface-treated calcium carbonate fillers (PE1) to (PE11) prepared in Examples 1 to 11 all have the ability to improve any one of the stability, heat resistance, dispersibility and strength of the resulting resin composition.

[0168] Thus, the surface-treated calcium carbonate filler of the present invention can reduce resin scorching or agglomeration during melt mixing of resin compositions using it, can suppress filter clogging, and provides excellent operational stability. Furthermore, it can, for example, provide polyolefin resin compositions that are less prone to strength degradation.

[0169] Industrial availability According to the present invention, it can be used, for example, in the fields of resin molding, construction / housing, coatings, and a wide range of related technical fields.

Claims

1. A surface-treated calcium carbonate filler that satisfies the following formulas (a), (b), (c), (e), (f) and (g): (a)2.0≤Sw≤20.0(m 2 / g) (b) 300≤Pw≤5000 (ppm) (c) 0.01≤Tw≤0.30 (mass%) (e)0.10≤D50≤2.00 (μm) (f)0.9≤(D90-D10) / D50≤2.0 (g) Da≤5.0 (μm) Sw is the BET specific surface area (m²) of the surface-treated calcium carbonate filler. 2 / g), Pw is the phosphorus content (ppm) of the surface-treated calcium carbonate filler, measured using an inductively coupled plasma (ICP) emission spectrometer. Tw is the weight loss (mass%) of the surface-treated calcium carbonate filler at 140℃~220℃, measured using a differential thermal balance. The D50 is the cumulative diameter (μm) from the small particle side in the volumetric particle size distribution of the surface-treated calcium carbonate filler, as measured using a laser diffraction particle size distribution measuring device. The D90 is the cumulative diameter (μm) from the small particle side in the volumetric particle size distribution of the surface-treated calcium carbonate filler, as measured by the laser diffraction particle size distribution measuring device. D10 is the cumulative diameter (μm) of the surface-treated calcium carbonate filler, measured using the laser diffraction particle size distribution measuring device, starting from the small particle side. Da is the maximum particle size (μm) in the volumetric particle size distribution of the surface-treated calcium carbonate filler, measured using the laser diffraction particle size distribution measuring device.

2. The surface-treated calcium carbonate filler according to claim 1, further satisfies the following formula (d): (d) 0.80≤bw≤1.50 The bw is the hue change rate calculated as follows: for a paste obtained by mixing the surface-treated calcium carbonate filler with dioctyl phthalate (DOP) at a mass ratio of 3:7, the yellow value (b value) before and after continuous heating at 140°C for 48 hours is measured using a spectrophotometer. Using this yellow value (b value), the following formula is used to calculate: Hue change rate (bw) = (b value of the paste after heating / b value of the paste before heating).

3. The surface-treated calcium carbonate filler according to claim 1, which is used to form a polyolefin resin composition.

4. A resin composition, characterized in that, It comprises resin and the surface-treated calcium carbonate filler as described in claim 1 or 2.

5. The resin composition according to claim 4, wherein, This resin is a polyolefin resin.

6. A molded article comprising the resin composition of claim 4.

7. The molded article according to claim 6, having a film morphology.