JP7070958B1 - Inorganic substance powder-filled resin composition and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a molded product having excellent molding processability and a good surface appearance, an inorganic substance powder-filled resin composition having good mechanical properties, particularly impact resistance and excellent flexibility, and an inorganic substance powder-filled resin composition. A molded product made of such a resin composition is provided. SOLUTION: In an inorganic substance powder-filled resin composition containing a thermoplastic resin and an inorganic substance powder in a mass ratio of 50:50 to 10:90, the thermoplastic resin is a polypropylene-based resin, and the inorganic substance. To 100 parts by mass of the powder-filled resin composition, 0.01% by mass or more of tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane is 0.10. An inorganic substance powder-filled resin composition containing 0.02% by mass or more and 0.20% by mass or less of tris (2,4-di-tert-butylphenyl) phosphite in an amount of mass% or less. [Selection diagram] None

Description

The present invention relates to an inorganic substance powder-filled resin composition and a molded product. More specifically, the present invention can produce a molded product having excellent molding processability and a good surface appearance, despite the fact that the thermoplastic resin is highly filled with the inorganic substance powder, and is a good machine. The present invention relates to a resin composition having specific properties, particularly impact resistance and exhibiting excellent flexibility, and a molded product comprising such a resin composition.

Conventionally, thermoplastic resins have been widely used together with paper materials derived from forest resources as materials for various industrial and household molded products, food packaging and molding packaging for general products, but environmental protection is required. Now that it has become an international issue, it is also being considered to reduce the consumption of thermoplastic resins and paper materials in parallel with the viewpoint of making them non-toxic, recyclable, and incinerated. From this point of view, an inorganic substance powder-blended thermoplastic resin composition in which an inorganic substance powder such as calcium carbonate is highly filled in a thermoplastic resin has been proposed and put into practical use (for example, Patent Documents). See 1st grade).

However, the resin composition highly filled with the inorganic substance powder tends to have generally lower molding processability and inferior mechanical strength (tensile strength, elongation) as compared with the resin alone. In particular, when molded into a thin sheet such as a film or injection molded, the production efficiency is low, and the molded product may have an appearance defect such as a striped flow mark (tiger stripe). In addition, the impact resistance tends to be significantly reduced, which causes problems such as problems during use.

As a means for improving the moldability of the resin composition, a technique of blending a lubricant or a plasticizer is known. For example, Patent Document 2 discloses a thermoplastic resin composition containing an inorganic substance powder to which an alkane sulfonate is added as a lubricant. Further, Patent Document 3 discloses a biodegradable resin composition in which heavy calcium carbonate particles are highly filled and a plasticizer such as a lactic acid oligomer is blended.

In addition to the above, a technique of blending a modified polymer or an elastomer component is known as a means for improving the mechanical properties and moldability of the resin composition. For example, Patent Document 4 describes a polypropylene resin composition containing a polypropylene resin, an elastomer having a polar functional group, and a filler.

Japanese Unexamined Patent Publication No. 2013-10931 Japanese Unexamined Patent Publication No. 2020-50831 Japanese Unexamined Patent Publication No. 2020-66721 JP-A-2019-99807

However, when a lubricant is added, the strength of the resin composition may decrease. Further, as the lubricant, metal soap-based lubricants such as saturated fatty acid amide and magnesium stearate are generally used, and such lubricants generate an odor. Therefore, the resin composition containing the lubricant is unsuitable especially for applications such as food molded products. In the resin composition described in Patent Document 2, an alkane sulfonate is used as a lubricant, and for example, an antioxidant is added in an amount of 0.3 parts by mass to reduce the odor, but the resin composition is completely odorless. It is difficult.

When a plasticizer is added to improve moldability, a part of the plasticizer may bleed on the surface of the resin composition or its molded product. Therefore, the resin composition containing a plasticizer is not very preferable as a medical / food material. Bleed may also deteriorate the appearance. Plasticizers may also reduce mechanical strength, such as tensile strength, while improving flexibility and elongation properties.

Even in the blending of modified polymers and copolymers, if the polymer to be blended is inappropriate, the highly filled resin composition may become rather brittle, or molding defects such as tiger stripes may occur. The same applies to the elastomer component, and the mechanical properties of the resin composition are not sufficiently improved unless the type to be blended is selected. In addition, these polymers are often expensive and have the disadvantage that the cost increase due to compounding is unavoidable.

The present invention has been made in view of the above circumstances, and it is possible to produce a molded product having excellent molding processability and a good surface appearance, and has good mechanical properties, particularly impact resistance, and flexibility. It is an object of the present invention to provide an excellent inorganic substance powder-filled resin composition and a molded product made of such a resin composition.

As a result of diligent studies to solve the above problems, the present inventors have used a polypropylene-based resin as the thermoplastic resin in the highly filled resin composition, and a specific phenol-based compound and a specific phosphite-based compound. By blending in small amounts in combination with the above, a molded product having excellent moldability and a good surface appearance can be produced, and an inorganic substance powder-filled resin composition having flexible and excellent mechanical properties such as impact resistance can be produced. We have found that it can be obtained and arrived at the present invention.

That is, the present invention relates to an inorganic substance powder-filled resin composition containing a thermoplastic resin and an inorganic substance powder in a mass ratio of 50:50 to 10:90.
The thermoplastic resin is a polypropylene-based resin and is
0.01% by mass or more of tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane with respect to 100 parts by mass of the inorganic substance powder-filled resin composition. An inorganic substance powder-filled resin containing 0.10% by mass or less and tris (2,4-di-tert-butylphenyl) phosphite in a proportion of 0.02% by mass or more and 0.20% by mass or less. It is a composition.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the tetrakis [methylene-3- (3', 5'-di-t-) is added to 100 parts by mass of the inorganic substance powder-filled resin composition. Butyl-4'-hydroxyphenyl) propionate] An inorganic substance powder-filled resin composition containing 0.01% by mass or more and 0.07% by mass or less of methane is shown.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the tris (2,4-di-tert-butylphenyl) phosphite is contained in a proportion of 0.08% by mass or more and 0.17% by mass or less. The inorganic substance powder-filled resin composition which has been used is shown.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and the tris ( An inorganic substance powder-filled resin composition containing 2,4-di-tert-butylphenyl) phosphite in a mass ratio of 1.0: 1.5 to 1.0: 8.0 is shown.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the inorganic substance powder-filled resin composition in which the inorganic substance powder is calcium carbonate is shown.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the inorganic substance powder-filled resin composition in which the inorganic substance powder is heavy calcium carbonate is shown.

In one aspect of the inorganic substance powder-filled resin composition according to the present invention, the heavy calcium carbonate has an average particle size of 0.7 μm or more and 6.0 μm or less by an air permeation method according to JIS M-8511. An inorganic substance powder-filled resin composition, which is calcium carbonate particles, is shown.

The present invention that solves the above problems is also a molded product comprising the above-mentioned inorganic substance powder-filled resin composition.

In one aspect of the molded product according to the present invention, the molded product is an injection molded product.

In one aspect of the molded product according to the present invention, the molded product is an extruded product.

According to the present invention, it is possible to produce a molded product having excellent molding processability and a good surface appearance, and an inorganic substance powder-filled resin having good mechanical properties, particularly impact resistance and excellent flexibility. It is possible to provide a composition and a molded product composed of such a resin composition. Although the resin composition of the present invention is highly filled with the inorganic substance powder in the thermoplastic resin, it does not require the addition of a lubricant or a plasticizer for improving workability, and thus is caused by these additives. It can avoid the risk of odor and bleeding, and is suitable for medical and food applications. Further, since it is not necessary to add an expensive modified polymer or copolymer, it is possible to avoid deterioration of physical properties and cost increase due to phase separation of the polymer.

Hereinafter, the present invention will be described in detail based on the embodiments.

≪Inorganic substance powder-filled resin composition≫
The inorganic substance powder-filled resin composition of the present invention contains a thermoplastic resin and an inorganic substance powder in a mass ratio of 50:50 to 10:90, and the thermoplastic resin is a polypropylene-based resin. To 100 parts by mass of the inorganic substance powder-filled resin composition, 0.01% by mass or more of tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane is 0. .10% by mass or less and contains tris (2,4-di-tert-butylphenyl) phosphite in a proportion of 0.02% by mass or more and 0.20% by mass or less. Hereinafter, each component constituting the inorganic substance powder-filled resin composition according to the present invention (hereinafter, may be abbreviated as “resin composition”) will be described in detail.

<Polypropylene resin>
The polypropylene-based resin that can be a component of the inorganic substance powder-filled resin composition according to the present invention is not particularly limited, and various polymers may be used depending on the use, function, and the like of the composition. The polypropylene-based resin is a resin containing a propylene unit as a main component, and its structure, molecular weight, and manufacturing method are not particularly limited. For example, it may be obtained by any of a method using a Ziegler-Natta catalyst, a metallocene catalyst, a radical initiator such as oxygen or a peroxide, or the like. The above-mentioned "main component" means that the resin contains 50% by mass or more of the propylene unit, and the content thereof is preferably 75% by mass or more, more preferably 85% by mass or more. Yes, more preferably 90% by mass or more. Examples thereof include a propylene homopolymer, a copolymer with another monomer copolymerizable with propylene, and the like. In particular, a polypropylene homopolymer is preferable.

<Propene homopolymer>
Propylene homopolymer (hereinafter, may be abbreviated as "PP") is a polymer obtained by polymerizing only propylene, and is excellent in rigidity and heat resistance. Various products are commercially available, such as Wintech (registered trademark) and Novatec (registered trademark) of Nippon Polypro Co., Ltd., Noblen (registered trademark) of Sumitomo Chemical Co., Ltd., and Prime Polypro (registered trademark) of Prime Polymer Co., Ltd. ), Toray Co., Ltd.'s Treca (registered trademark), SABIC Petrochemicals' SABIC (registered trademark) PP, and Sun Aroma Co., Ltd.'s Sun Aroma (registered trademark). PP may be included. Multiple types of PP can be used in combination.

Propylene homopolymers are classified into isotactic PP, syndiotactic PP, atactic PP, hemiisotactic PP and the like according to the difference in stereoregularity. The resin composition of the present invention may contain any of these, and a plurality of types thereof may be used in combination. Further, the homopolymer may contain a trace component produced as a by-product during polymerization, or may have a branched structure. For example, as a result of polymerization, a structure as if an α-olefin such as hexene was copolymerized may be contained in an amount of 5% by mass or less, particularly about 1% by mass or less. In the present invention, such a polymer is also contained. Widely included as a propylene homopolymer (propylene homopolymer).

The molecular weight of the propylene homopolymer is also not particularly limited. However, in the present invention, it is preferable to use PP having a mass average molecular weight of about 50,000 or more and 500,000 or less, particularly about 100,000 or more and 400,000 or less. Generally, the higher the molecular weight, the better the mechanical properties such as strength, and the lower the molecular weight, the better the moldability. Those having a mass average molecular weight of about 50,000 or more and less than 200,000 and those having a mass average molecular weight of about 200,000 or more and 500,000 or less can be used in combination. By using PPs having different molecular weights in combination, it is possible to improve the moldability and reduce the appearance defects of the molded product.

<Propene copolymer>
The resin composition of the present invention may contain a propylene copolymer as a polypropylene-based resin. Copolymerization components with propylene include ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, and 3-methyl. Olefin such as -1-hexene, 1-octene and cycloolefin; vinyl compounds such as vinyl acetate and (meth) acrylic acid (ester), acrylonitrile and acrylamide; halides such as vinyl chloride, tetrafluoroethylene and vinylidene fluoride However, it is not limited to these. It may be a ternary or quaternary copolymer containing a plurality of types of copolymerization components. The form of the copolymer is not limited, and various forms of copolymer such as a random copolymer, a block copolymer, an alternate copolymer, and a graft copolymer can be used. As described above, the polypropylene-based resin in the present invention is preferably a propylene homopolymer, but a copolymer of propylene and α-olefin or block polypropylene is also suitable. Further, both a propylene homopolymer and a copolymer can be used in combination.

<Propene block copolymer>
A propylene block copolymer is a copolymer composed of a block in which a propylene monomer is continuous and a block in which other monomer components are continuous. Block copolymers of propylene and α-olefins are known and various varieties are commercially available. Examples include Novatec (registered trademark) of Nippon Polypro Co., Ltd., Prime Polypro (registered trademark) of Prime Polymer Co., Ltd., Umex (registered trademark) of Sanyo Kasei Kogyo Co., Ltd., and SunAllomer (registered trademark) of SunAllomer Ltd. However, the present invention is not limited to these, and any propylene block copolymer may be contained. The propylene block copolymer also includes a blend polymer having a sea-island structure in which a homopolypropylene chain and an ethylene-propylene copolymer chain are not chemically bonded in a broad sense, and such a polymer can be used in the present invention. can. It is also possible to use two or more types of block copolymers in combination. The copolymerization ratio and molecular weight are not particularly limited, but the structural unit derived from α-olefin, which is a copolymerization monomer, is preferably 5% by mass or more, more preferably 7% by mass or more, and particularly preferably 8% by mass or more. A polymer and a copolymer having the same structural unit of preferably 35% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, particularly preferably 18% by mass or less can be used. .. Further, a polymer having a mass average molecular weight in the range of 20,000 to 5,000,000, typically 50,000 to 1,000,000, particularly 70,000 to 400,000 is preferable. These block copolymers are highly flexible and exhibit particularly excellent mechanical properties and moldability when blended in the inorganic substance powder-filled resin composition of the present invention.

The block copolymer of propylene and α-olefin may also contain a structural unit derived from a third component such as a diene or a carboxylic acid (ester) modified olefin. The diene components include 1,4-hexadiene, 1,6-octadien, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadien, dicyclopentadiene (DCPD), and ethylidene norbornene (ENB). ), Norbornadiene, 5-vinyl-2-norbornene, etc .; Examples of the carboxylic acid (ester) -modified olefin include, but are not limited to, carboxyl group-containing olefins. A copolymer containing, for example, 0.1 to 10% by mass, particularly 0.5 to 8% by mass, particularly 1 to 5% by mass, of a constituent unit derived from these third components is the same as the above block copolymer containing no third component. May exhibit different melting behaviors and compatibility, and it is also possible to control the physical properties and processability of the inorganic substance powder-filled resin composition of the present invention by blending them. Since the constituent unit derived from diene can also be a cross-linking site, the block copolymer can be partially cross-linked by mixing with a cross-linking agent such as a peroxide to modify the processability. Further, by using the block copolymer having a functional group such as a carboxylic acid group, miscibility with the inorganic substance powder may be enhanced, and physical properties and moldability may be improved.

In the inorganic substance powder-filled resin composition of the present invention, the thermoplastic resin is the above-mentioned polypropylene-based resin, but it may be further composed of other resin components. For example, thermoplastic resins such as poly (meth) acrylic acid (ester), polyvinyl acetate, polyacrylonitrile, polystyrene, ABS resin, polycarbonate, polyamide, polyvinyl alcohol, petroleum hydrocarbon resin, kumaron inden resin; and further, styrene-. Examples thereof include elastomers such as butadiene copolymers, styrene-isoprene copolymers, styrene-butadiene-ethylene copolymers, styrene-isoprene-ethylene copolymers, acrylonitrile-butadiene copolymers, and fluoroevaporants. By blending these resin components, the physical characteristics and processability of the inorganic substance powder-filled resin composition may be improved.

However, in the inorganic substance powder-filled resin composition of the present invention, the thermoplastic resin component is preferably 90% by mass or more, more preferably 97% by mass or more, and particularly preferably substantially, from the viewpoint of compatibility of each component. The whole amount is made of the above-mentioned polypropylene-based resin. If the resin composition is an inorganic substance powder-filled resin composition that does not substantially contain resin components other than these, there is no possibility that a part of the resin components will be separated, and deterioration of mechanical properties and moldability can be prevented.

<Inorganic substance powder>
The inorganic substance powder-filled resin composition of the present invention contains an inorganic substance powder together with the above-mentioned thermoplastic resin. The inorganic substance powder is not particularly limited, and is, for example, carbonates such as calcium, magnesium, aluminum, titanium, iron, and zinc, sulfates, silicates, phosphates, borates, oxides, or water thereof. Examples thereof include powdered Japanese products, and specific examples thereof include calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clays such as talc and kaolin, aluminum hydroxide, magnesium hydroxide, and kei. Aluminum acid, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous soil, sericite, silas, calcium sulfite, sodium sulfate, titanium Examples thereof include potassium acid acid, bentonite, wollastonite, dolomite, graphite and the like. These may be synthetic or derived from natural minerals, and they may be contained alone or in combination of two or more.

Further, the shape of the inorganic substance powder is not particularly limited, and may be in the form of particles, flakes, granules, fibers, or the like. Further, it may be in the form of particles, which may be spherical as generally obtained by a synthetic method, or may have an indefinite shape as obtained by pulverizing the collected natural minerals. ..

These inorganic substance powders are preferably calcium carbonate, magnesium carbonate, dolomite, zinc oxide, titanium oxide, silica, alumina, clay such as talc and kaolin, aluminum hydroxide, magnesium hydroxide and the like, and particularly include calcium carbonate. The one is preferable. Further, the calcium carbonate is either so-called light calcium carbonate prepared by a synthetic method or so-called heavy calcium carbonate obtained by mechanically crushing and classifying a natural raw material containing CaCO ₃ as a main component such as limestone. It may be present, or it may be a combination of these.

However, in the present invention, it is preferable to use an inorganic substance powder containing heavy calcium carbonate. Here, heavy calcium carbonate is obtained by mechanically crushing and processing natural limestone or the like, and is clearly distinguished from synthetic calcium carbonate produced by a chemical precipitation reaction or the like. There are two types of pulverization methods, a dry method and a wet method, but the dry method is preferable.

The heavy calcium carbonate particles are characterized by the irregularity of the surface and the size of the specific surface area due to the particle formation performed by the pulverization treatment, unlike the light calcium carbonate obtained by the synthetic method, for example. Due to the irregularity and specific surface area of the heavy calcium carbonate particles, the heavy calcium carbonate particles have more contact interfaces with the thermoplastic resin when blended in the thermoplastic resin. It has an effect on uniform dispersion.

Although not particularly limited, the specific surface area of the heavy calcium carbonate particles may be about 3,000 cm ^{2 / g or more and 35,000 cm 2 /} g or less, although it depends on the average particle size. desired. The specific surface area referred to here is based on the air permeation method. When the specific surface area is within this range, the deterioration of workability of the obtained molded product tends to be suppressed.

Further, the indeterminate form of the heavy calcium carbonate particles can be expressed by the low degree of spheroidization of the particle shape, and is not particularly limited, but specifically, the roundness is 0.50. More than 0.95 or less, more preferably 0.55 or more and 0.93 or less, still more preferably 0.60 or more and 0.90 or less. When the roundness of the heavy calcium carbonate particles is within this range, the strength and moldability of the molded product are also appropriate. Here, the roundness can be expressed by (projected area of particles) / (area of a circle having the same perimeter as the projected perimeter of particles). The method for measuring the roundness is not particularly limited, and for example, the projected area of the particles and the projected peripheral length of the particles may be measured from a micrograph, or a commercially available image analysis software may be used.

Further, the surface may be surface-modified according to a conventional method in order to enhance the dispersibility or reactivity of the inorganic substance powder. Examples of the surface modification method include a physical method such as plasma treatment and a method of chemically surface-treating the surface with a coupling agent or a surfactant. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. The surfactant may be anionic, cationic, nonionic or amphoteric, and examples thereof include higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid salts. On the contrary, it may contain an inorganic substance powder that has not been surface-treated.

The inorganic substance powder such as heavy calcium carbonate particles is not particularly limited, but the average particle size thereof is preferably 0.5 μm or more and 9.0 μm or less, and more preferably 0.7 μm or more and 6.0 μm or less. , 1.0 μm or more and 4.0 μm or less is more preferable, and 1.2 μm or more and 3.0 μm or less is particularly preferable. The average particle size of the inorganic substance powder described in the present specification is a value calculated from the measurement result of the specific surface area by the air permeation method according to JIS M-8511. As the measuring device, for example, a specific surface area measuring device SS-100 manufactured by Shimadzu Corporation can be preferably used. When the average particle size is larger than 9.0 μm, for example, when a sheet-shaped molded product is formed, the inorganic substance powder protrudes from the surface of the molded product and the powder falls off, depending on the layer thickness of the molded product. There is a risk of damage to the surface texture and mechanical strength. In particular, it is preferable that the particle size distribution does not contain particles having a particle size of 45 μm or more. On the other hand, if the particles become too fine, the viscosity may be remarkably increased when kneaded with the above-mentioned resin, which may make it difficult to manufacture a molded product. In order to reduce such a risk, it is effective to keep the average particle size of the inorganic substance powder within the above range.

As described above, in the present invention, it is preferable to use calcium carbonate as the inorganic substance powder. If desired, the calcium carbonate may be a first calcium carbonate having an average particle size of 0.5 μm or more and less than 2.0 μm, particularly 0.7 μm or more and less than 2.0 μm, as measured by the air permeation method according to JIS M-8511. It may contain a second calcium carbonate having an average particle size of 2.0 μm or more and less than 9.0 μm, particularly 2.0 μm or more and less than 6.0 μm, as measured by the air permeation method according to JIS M-8511. This makes it possible to improve the surface properties of the molded product and the physical properties such as printability and blocking property. In addition, uneven distribution of calcium carbonate is suppressed, a molded product having good appearance and mechanical properties such as elongation at break can be obtained, and it is possible to reduce the loss of calcium carbonate from the molded product of the resin composition. .. Although not particularly limited, when the average particle size of the first calcium carbonate is a and the average particle size of the second calcium carbonate is b, the a / b ratio is more preferably 0.85 or less. Is preferably 0.10 to 0.70, and more preferably 0.10 to 0.50. This is because a particularly excellent effect can be expected by using those having a certain difference in average particle size in combination. Further, it is desirable that the coefficient of variation (Cv) of the distribution of the particle size (μm) of each of the first calcium carbonate and the second calcium carbonate is about 0.01 to 0.10, particularly 0.03. It is desirable that it is about 0.08. If the variation in the particle size defined by the coefficient of variation (Cv) is about this level, it is considered that each powder group can give a more complementary effect. The mass ratio of the first calcium carbonate to the second calcium carbonate is preferably 90:10 to 98: 2, particularly 92: 8 to 95: 5. As the calcium carbonate group having different average particle size distributions, three or more may be used. Further, both the first calcium carbonate and the second calcium carbonate may be surface-treated heavy calcium carbonate.

In the inorganic substance powder-filled resin composition of the present invention, the above-mentioned thermoplastic resin and the inorganic substance powder are contained in a mass ratio of 50:50 to 10:90. This is because if the content of the inorganic substance powder is small, it is difficult to obtain physical properties such as the texture and strength of the resin composition, and if it is too large, kneading and molding are difficult, and the flexibility is insufficient. The ratio of the inorganic substance powder to the total mass of the thermoplastic resin and the inorganic substance powder is preferably 55% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The upper limit of the ratio is preferably 85% by mass or less, more preferably 82% by mass or less, and particularly preferably 80% by mass or less.

<Formulation of inorganic substance powder-filled resin composition>
The inorganic substance powder-filled resin composition of the present invention, together with the above-mentioned thermoplastic resin and inorganic substance powder, comprises a specific amount of tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl). ) Propionate] Contains methane and tris (2,4-di-tert-butylphenyl) phosphite. By blending both of these in small amounts, it is possible to produce a molded product with excellent moldability and a good surface appearance, despite the fact that it is filled with a large amount of inorganic substance powder, and it is flexible and has excellent impact resistance. It is possible to obtain an inorganic substance powder-filled resin composition having the mechanical properties of the above.

Tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] Methane itself is known and commercially available. Examples thereof include, but are not limited to, Irganox (registered trademark) 1010 of BASF, and ADEKA STAB (registered trademark) AO-60 of ADEKA CORPORATION. This compound has a structure of [HO-C ₁₄ H ₂₀ -C ₂ H ₄ -COO-CH ₂ ] ₄ C and has a pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate]. It is a so-called hindered phenol compound having t-butyl groups on both sides of the phenolic hydroxyl group, and has an action of preventing thermal oxidative deterioration and discoloration of the resin like other hindered phenols.

Tris (2,4-di-tert-butylphenyl) phosphite is also known and commercially available. Examples thereof include, but are not limited to, Irgafos (registered trademark) 168 of BASF, and ADEKA STAB (registered trademark) 2112 of ADEKA CORPORATION. This compound has a structure of ₍ C 14H _{21 -} O) 3P, and has peroxide resolution and discoloration prevention effect like other phosphite compounds.

As described above, many hindered phenol compounds and phosphite compounds have an action of preventing deterioration and discoloration of the resin, and therefore various compounds are used as, for example, deterioration / discoloration preventing agents for polymer coating films (for example). See Japanese Patent Publication No. 2016-531962).

Among these many hindered phenol compounds and phosphite compounds, the present inventors have tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris. It has been found that the processability, flexibility and mechanical properties of the highly filled resin composition are improved by blending a specific amount of the combination of (2,4-di-tert-butylphenyl) phosphite. As shown in Examples described later, in the highly filled resin composition, even if other types of general-purpose hindered phenol compounds and phosphite compounds are used, the improvement in processability and mechanical properties aimed at by the present invention can be achieved. It's hard to do. On the other hand, when tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris (2,4-di-tert-butylphenyl) phosphite are combined, Not only can the deterioration and discoloration of the resin be prevented, but also the processability and mechanical properties of the highly filled resin composition can be improved.

In the resin composition of the present invention, the contents of the hindered phenol compound and the phosphite compound are also important in obtaining the desired effect. That is, the resin composition of the present invention is tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] with respect to 100 parts by mass of the inorganic substance powder-filled resin composition. 0.01% by mass or more and 0.10% by mass or less of methane, preferably 0.01% by mass or more and 0.08% by mass or less, more preferably 0.01% by mass or more and 0.06% by mass or less, still more preferably 0. 0.02% by mass or more and 0.05% by mass or less, particularly preferably 0.03% by mass or more and less than 0.05% by mass, for example, at a ratio of 0.04% by mass or less; Tris (2,4-di-tert-butyl) Phenyl) phosphite is 0.02% by mass or more and 0.20% by mass or less, preferably 0.05% by mass or more and 0.18% by mass or less, more preferably 0.08% by mass or more and 0.17% by mass or less, and further. It is preferably contained in an amount of 0.10% by mass or more and 0.17% by mass or less, and particularly preferably 0.12% by mass or more and 0.16% by mass or less. With such a blending amount, the processability of the highly filled resin composition, for example, melt fluidity and weld characteristics are improved, appearance defects such as tiger stripes, flow marks, and rough skin on the surface are suppressed, and impact resistance and other machines are used. Characteristics and flexibility can also be improved. In addition, it is possible to avoid deterioration of appearance, deterioration of adhesiveness, risk of odor generation, etc. due to bleeding of the blended components.

The resin compositions of the present invention also include tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris (2,4-di-tert-butylphenyl). ) Phosphite, preferably with a mass ratio of 1.0: 1.5 to 1.0: 8.0, more preferably 1.0: 2.0 to 1.0: 6.0, still more preferably 1. It is contained in a ratio of 0: 2.1 to 1.0: 5.0, particularly preferably 1.0: 2.5 to 1.0: 4.0. With such a compounding ratio, the processability and mechanical properties of the highly filled resin composition can be more reliably improved.

<Other additives>
If necessary, other additives may be added to the inorganic substance powder-filled resin composition according to the present invention as an auxiliary agent. Other additives include, for example, lubricants, plasticizers, colorants, coupling agents, fluidity improvers (fluidity modifiers), cross-linking agents, dispersants, UV absorbers, flame retardants, foaming agents, antistatic agents. Agents, antioxidants other than the above, stabilizers and the like may be blended. These additives may be used alone or in combination of two or more. Further, these may be blended in the kneading step described later, or may be blended in the raw material components in advance before the kneading step. In the inorganic substance powder-filled resin composition according to the present invention, the amount of these other additives added is not particularly limited as long as it does not impair the desired physical properties and processability, but for example, the inorganic substance powder-filled resin. When the total mass of the composition is 100%, these other additives are each about 0 to 10% by mass, particularly about 0.04 to 5% by mass, and the total amount of the other additives is 10. It is desirable that the mixture is blended in a proportion of mass% or less.

The following describes examples of these that are considered to be important, but the present invention is not limited to these.

Examples of the lubricant include fatty acid-based lubricants such as stearic acid, hydroxystearic acid, complex stearic acid, and oleic acid; aliphatic alcohol-based lubricants; Adipose amide lubricants such as amide, methylene bisstearoamide, methylene bisstearobehenamide, higher fatty acid bisamide acid, complex amide; stearic acid-n-butyl, methyl hydroxystearate, polyhydric alcohol fatty acid ester, Fatty acid ester-based lubricants such as saturated fatty acid esters and ester-based waxes; fatty acid metal soap-based lubricants such as zinc stearate; and sulfonates such as sodium alkanesulfonate can be mentioned. It is also possible to blend these lubricants together with the above-mentioned hindered phenol compound and phosphite compound to further improve the processability of the inorganic substance powder-filled resin composition of the present invention.

However, in order to reduce the risk of the above-mentioned odor, the blending amount of such an aliphatic amide-based or sulfonate lubricant is less than 0.2 parts by mass, for example, 0.01 to 100 parts by mass with respect to 100 parts by mass of the thermoplastic resin. It is preferably limited to about 0.1 part by mass, and more preferably not blended.

Examples of the plasticizer include triethyl citrate, acetyl triethyl citrate, dibutyl phthalate, diaryl phthalate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, di (2-ethylhexyl) phthalate, and di-phthalate. Examples thereof include 2-methoxyethyl, dibutyl tartrate, o-benzoylbenzoic acid ester, diacetin, epoxidized soybean oil and the like. These plasticizers are usually blended in an amount of about several mass% with respect to the thermoplastic resin, but the amount thereof is not limited to these ranges, and depending on the purpose of the molded product, epoxidized soybean oil or the like is blended in an amount of about 20 to 50 parts by mass. It is also possible to do. However, in the inorganic substance powder-filled resin composition of the present invention, even when a plasticizer is blended, the blending amount thereof is 0.5 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic resin from the viewpoint of improving the appearance of the molded product. In particular, it is preferably about 1 to 5 parts by mass. More preferably, the composition is such that no plasticizer is added. In the inorganic substance powder-filled resin composition of the present invention, since the processability can be improved only by the above-mentioned hindered phenol compound and the above-mentioned phosphite compound, it is possible to make the compound not only plastic and also the above-mentioned lubricant-free compound.

As the colorant, any known organic pigment, inorganic pigment or dye can be used. Specifically, organic pigments such as azo-based, anthracinone-based, phthalocyanine-based, quinacridone-based, isoindoleinone-based, geoosazine-based, perinone-based, quinophthalone-based, and perylene-based pigments, ultramarine, titanium oxide, titanium yellow, and iron oxide. (Valve handle), chrome oxide, zinc flower, carbon black and other inorganic pigments can be mentioned.

As the antioxidant, a phosphorus-based antioxidant, a phenol-based antioxidant, and a pentaerythritol-based antioxidant other than the above can be used in combination. Phosphorus-based, more specifically, phosphorus-based antioxidant stabilizers such as phosphite ester and phosphoric acid ester are preferably used. Examples of the phosphorous acid ester include triesters of phosphorous acids such as triphenylphosphite and trisnonylphenylphosphite, diesters and monoesters.

Examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2-ethylphenyldiphenyl phosphate and the like. These phosphorus-based antioxidants may be used alone or in combination of two or more.

Phenolic antioxidants include α-tocopherol, butylhydroxytoluene, cinapyl alcohol, vitamin E, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2- t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenylacrylate, 2,6-di-t-butyl-4- (N, N-dimethyl) Aminomethyl) phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester and the like are exemplified, and these can be used alone or in combination of two or more.

The flame retardant is not particularly limited, but for example, a halogen-based flame retardant or a non-phosphorus-based halogen-based flame retardant such as a phosphorus-based flame retardant or a metal hydrate can be used. Specific examples of the halogen-based flame retardant include halogenated bisphenol compounds such as halogenated bisphenylalkane, halogenated bisphenyl ether, halogenated bisphenylthio ether, and halogenated bisphenyl sulfone, brominated bisphenol A, and bromine. Bisphenol-bis (alkyl ether) compounds such as bisphenol S, chlorinated bisphenol A, chlorinated bisphenol S, etc., and as phosphorus-based flame retardants, tris (diethylphosphinic acid) aluminum, bisphenol A bis (diphenyl phosphate) , Triaryl isopropyl phosphate, cresyldi 2, 6-xylenyl phosphate, aromatic condensed phosphate ester, etc., as metal hydrates, for example, aluminum trihydrate, magnesium dihydration, or a combination thereof. Etc. can be exemplified respectively, and these can be used alone or in combination of two or more kinds. It works as a flame-retardant aid and can improve the flame-retardant effect more effectively. Further, for example, antimony oxide such as antimony trioxide and antimony pentoxide, zinc oxide, iron oxide, aluminum oxide, molybdenum oxide, titanium oxide, calcium oxide, magnesium oxide and the like can be used in combination as a flame retardant aid. ..

The effervescent agent is a substance that is mixed or press-fitted into an inorganic substance powder-filled resin composition that is a raw material that is in a molten state in a melt-kneader and undergoes a phase change from a solid to a gas, from a liquid to a gas, or the gas itself. It is mainly used to control the foaming ratio (foaming density) of the foamed sheet. As for the foaming agent, the one that is liquid at room temperature changes its phase to a gas depending on the resin temperature and dissolves in the molten resin, and the one that is gas at room temperature does not change its phase and dissolves in the molten resin as it is. When the molten resin is extruded into a sheet from an extrusion die, the foaming agent dispersed and dissolved in the molten resin expands inside the sheet because the pressure is released, and foams by forming a large number of fine closed cells in the sheet. A sheet is obtained. The foaming agent secondarily acts as a plasticizer that lowers the melt viscosity of the raw material resin composition, and lowers the temperature for bringing the raw material resin composition into a plasticized state.

Examples of the effervescent agent include aliphatic hydrocarbons such as propane, butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclobutane, cyclopentane and cyclohexane; chlorodifluoromethane, difluoromethane, trifluoromethane and trichlorofluoro. Methan, dichloromethane, dichlorofluoromethane, dichlorodifluoromethane, chloromethane, chloroethane, dichlorotrifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane , Tetrachlorodifluoroethane, halogenated hydrocarbons such as perfluorocyclobutane; inorganic gases such as carbon dioxide, nitrogen, air; water and the like.

Further, as the foaming agent, for example, a carrier resin containing an active ingredient of the foaming agent can be preferably used. Examples of the carrier resin include crystalline olefin resins. Of these, crystalline polypropylene resin is preferable. In addition, examples of the active ingredient include hydrogen carbonate and the like. Of these, bicarbonate is preferred. It is preferable that the foaming agent concentrate contains a crystalline polypropylene resin as a carrier resin and a bicarbonate as a pyrolytic foaming agent.

The content of the foaming agent contained in the foaming agent in the molding step can be appropriately set according to the amount of the thermoplastic resin and the inorganic substance powder, and is 0. It is preferably in the range of 04 to 5.00% by mass.

As the fluidity adjusting agent, various conventional ones can be used. Examples include, but are not limited to, peroxides such as dialkyl peroxide, such as 1,4-bis [(t-butylperoxy) isopropyl] benzene. Depending on the type of thermoplastic resin used, these peroxides also act as cross-linking agents. The amount of the peroxide added is not particularly limited, but is in the range of 0.04 to 2.00% by mass, particularly about 0.05 to 0.50% by mass, based on the total mass of the inorganic substance powder-filled resin composition. It is preferable to do so.

As the antistatic agent, for example, fatty acid diethanolamides such as lauryl diethanolamide and stearyl diethanolamide, and hydroxyl group-containing compounds such as alcohol amine compounds can be used. In particular, alcohol amines such as monoethanolamine, diethanolamine, triethanolamine and the like are preferable. Two or more antistatic agents can also be used in combination. These antistatic agents may be supported on calcium silicate, calcium carbonate, or the like. The range of carbon atoms of the acyl group of the fatty acid diethanolamide is preferably about 8 to 22 from the viewpoint that a sufficient antistatic effect can be exhibited. The amount of such an antistatic agent to be blended is about 0.01 to 8.00% by mass, more preferably 0.02, when the total mass of the inorganic substance powder blended thermoplastic resin composition is 100% by mass. It is desirable that the mixture is blended in an amount of about 4.00% by mass, more preferably 0.05 to 3.00% by mass, and particularly about 0.10 to 1.50% by mass. By using the product within this range, a sufficient antistatic effect can be obtained, and there is little possibility that the resin surface becomes sticky or adversely affects the resin physical properties.

<< Manufacturing method of inorganic substance powder-filled resin composition >>
As a method for producing the inorganic substance powder-filled resin composition of the present invention, an ordinary method can be used, and appropriately set according to the molding method (extrusion molding, injection molding, vacuum molding, etc.), for example, a thermoplastic resin. And the inorganic substance powder may be melt-kneaded. In melt kneading, it is preferable to knead by applying a high shear stress while uniformly dispersing each component. As the mixing device, various devices such as a general extruder, a kneader, and a Banbury mixer can be used, but it is preferable to knead with a twin-screw kneader, for example.

In the production method of the present invention, thermoplastic resin, inorganic substance powder, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, and tris (2,4). -The kneading order of di-tert-butylphenyl) phosphite is not particularly limited. For example, these four can be kneaded at the same time, and a dry blend of components other than the thermoplastic resin can be kneaded with the thermoplastic resin. Further, after kneading a part of the thermoplastic resin, for example, 1/2 to 3/4 and another raw material to prepare a first resin composition, this resin composition and the remaining 1/2 to 1/4 are prepared. May be kneaded with the thermoplastic resin of. Tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris (2,4-di-tert-butylphenyl) phosphite have resin compositions. It may be kneaded into the product at the same time, or it may be kneaded separately.

In the method for producing an inorganic substance powder-filled resin composition of the present invention, the inorganic substance powder-filled resin composition may be in the form of pellets or not in the form of pellets, but in the case of pellets, it may be in the form of pellets. The shape of the above is not particularly limited, and for example, pellets such as a cylinder, a sphere, and an elliptical sphere may be formed.

The size of the pellet may be appropriately set according to the shape, but for example, in the case of a spherical pellet, the diameter may be 1 to 10 mm. In the case of an elliptical spherical pellet, the pellet may have an elliptical shape with an aspect ratio of 0.1 to 1.0 and an aspect ratio of 1 to 10 mm. In the case of cylindrical pellets, the diameter may be in the range of 1 to 10 mm and the length may be in the range of 1 to 10 mm. These shapes may be formed on the pellets after the kneading step described later. The shape of the pellet may be formed according to a conventional method.

≪Molded product≫
The molded product according to the present invention is a molded product made of the above-mentioned inorganic substance powder-filled resin composition.

The shape of the molded product according to the present invention is not particularly limited, and may be of various shapes. Since the inorganic substance powder-filled resin composition of the present invention has excellent moldability, various shapes such as sheets, especially substitutes for paper and synthetic paper, daily necessities such as brushes and shoehorns, housings for remote controls and telephones, etc. In addition, it can be molded as various molded products such as food containers and other containers. Since the molded product of the present invention has excellent flexibility, it is suitable as a housing, a sheet, a daily necessities, etc. to which force is applied during assembly and use. Since the molded product of the present invention does not have an odor caused by a lubricant or a bloom of a plasticizer, it can be used for various purposes such as medical use and food use.

The wall thickness of the molded product according to the present invention is not particularly limited, and may vary from thin to thick depending on the form of the molded product. For example, the wall thickness is 40 μm. A molded product having a wall thickness of about 40 mm, more preferably 50 μm to 30 mm is shown. If the wall thickness is within this range, it is possible to form a homogeneous and defect-free molded product without any problems of moldability and workability and without causing uneven thickness.

In particular, when the form of the molded product is a sheet, it is more preferably 50 μm to 1,000 μm in wall thickness, and further preferably 50 μm to 400 μm in wall thickness. A sheet having a wall thickness within such a range can be suitably used in place of general printing / information and packaging paper or synthetic paper.

≪Manufacturing method of molded products≫
The method for producing the molded product of the present invention is not particularly limited as long as it can be molded into a desired shape, and may be any of conventionally known methods such as extrusion molding, injection molding, vacuum molding, blow molding and calendar molding. Molding is possible. In particular, injection molding and extrusion molding are preferable. Furthermore, even when the inorganic substance powder-filled resin composition according to the present invention contains a foaming agent to obtain a molded product in the form of a foam, a method for molding the foam can be obtained as long as it can be molded into a desired shape. Any of the conventionally known liquid phase foaming methods such as injection foaming, extrusion foaming, and foaming blow, or solid phase foaming methods such as bead foaming, batch foaming, press foaming, and normal pressure secondary foaming is used. It is also possible. In one aspect of the above-mentioned thermoplastic composition containing crystalline polypropylene as a carrier resin and hydrogen carbonate as a pyrolytic foaming agent, an injection foaming method and an extrusion foaming method can be preferably used.

<Manufacturing method of injection molded products>
Since the inorganic substance powder-filled resin composition of the present invention is also excellent in moldability as described above, it can be molded into articles having various shapes by injection molding. The present invention also includes molded articles of the above-mentioned inorganic substance powder-filled resin compositions, particularly injection molded articles. Such a molded product of the present invention has the advantages of having no appearance defects such as tiger stripes and having excellent mechanical properties such as flexibility. Since a part of the raw material of the inorganic substance powder-filled resin composition also exerts such an effect in the product recovered from the market or the factory, the molded product of the present invention exhibits good characteristics even if it is a recycled product.

<Manufacturing method of extruded products>
The inorganic substance powder-filled resin composition of the present invention can also be molded into articles having various shapes such as sheets, rods, pipes, tubes and strands by extrusion molding. The present invention also includes an extruded product of the above-mentioned inorganic substance powder-filled resin composition. The extrusion molding method is not particularly limited, and general-purpose single-screw extrusion, twin-screw extrusion, or the like can be used. Further, a direct method in which the step of kneading each component and the step of molding into a sheet or the like are continuously performed may be used, or for example, a method using a T-die type twin-screw extrusion molding machine may be used. ..

In the case of forming into a sheet, it is possible to stretch in the uniaxial direction or the biaxial direction or in the multiaxial direction (stretching by the tubular method, etc.) at the time of the molding or after the molding. In the case of biaxial stretching, sequential biaxial stretching or simultaneous biaxial stretching may be used. When the sheet after molding is stretched (for example, longitudinally and / or laterally stretched), minute voids are generated in the sheet. The whiteness of the sheet becomes good due to the formation of minute voids in the sheet.

The molding temperature in injection molding, extrusion molding, etc. varies to some extent depending on the molding method, the type of polypropylene-based resin used, etc., and therefore cannot be unconditionally specified, but is, for example, 180 to 260 ° C. Preferably, at a temperature of 190 to 230 ° C., the inorganic substance powder-filled resin composition according to the present invention has good draw-down characteristics and spreadability, and the composition does not cause local modification. Can be molded into a predetermined shape.

Hereinafter, the present invention will be described in more detail based on examples. It should be noted that these examples are specific embodiments and practices in order to facilitate understanding of the concepts and scope of the present invention disclosed in the present specification and described in the appended claims. The present invention is described only for the purpose of exemplifying the embodiments, and the present invention is not limited to these examples.

In the following examples, various inorganic substance powder-filled resin compositions were prepared using the following raw materials and molded into test pieces.
Polypropylene resin PR1: Propylene homopolymer manufactured by Prime Polymer Co., Ltd. (MFR: 0.5 g / 10 min, melting point 160 ° C)
PR2: Propylene homopolymer manufactured by Prime Polymer Co., Ltd. (MFR: 2.0 g / 10 min)
PR3: Polypropylene manufactured by Prime Polymer Co., Ltd. (random type, MFR: 0.5 g / 10 min)
PR4: Polypropylene manufactured by Prime Polymer Co., Ltd. (block type, MFR: 0.9 g / 10 min, melting point: 160 to 165 ° C)
-Calcium carbonate CC1: Heavy calcium carbonate powder (without surface treatment) Average particle size: 0.7 μm, BET specific surface area 3.2 m ² / g, roundness: 0.53
CC2: Heavy calcium carbonate powder (without surface treatment) Average particle size: 1.1 μm, BET specific surface area: 3.2 m ² / g, roundness: 0.55
CC3: Heavy calcium carbonate powder (without surface treatment) Average particle size: 2.2 μm, BET specific surface area: 1.0 m ² / g, roundness: 0.85
CC4: Heavy calcium carbonate powder (without surface treatment) Average particle size: 3.6 μm, BET specific surface area: 0.6 m ² / g, roundness: 0.90
CC5: Heavy calcium carbonate powder (surface-treated product) CC2 stearic acid-treated product CC6: Light calcium carbonate (without surface treatment) Average particle size: 1.5 μm, BET specific surface area: 0.1 m ² / g, perfect circle Degree: 1.00
-Other inorganic substance powder K1: Kaolin clay Volume average particle size: 1.50 μm, specific density 2.6
T1: Talc volume average particle size: 3.3 μm
・ Hindered phenol compound (phenol)
HP1: Tetrakis [Methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] Methane ADEKA STAB (registered trademark) AO-60 manufactured by ADEKA Corporation
HP2: Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate ADEKA STAB (registered trademark) AO-50 manufactured by ADEKA Corporation
HP3: Isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate BASF's Irganox® 1135
-Phosphite compound P1: Tris (2,4-di-tert-butylphenyl) phosphite ADEKA CORPORATION ADEKA STAB (registered trademark) 2112
P2: Triphenylphosphine Co., Ltd. ADEKA's ADEKA STAB (registered trademark) TPP
P3: ADEKA STAB (registered trademark) 3010 of ADEKA Corporation
-Other additives S: Sodium alkanesulfonate (carbon number (average value) of alkyl group = 12) Lubricants DOP: Dioctylphthalate General-purpose plasticizer A1: Triethanolamine A2: Lauryldiethanolamide A3: Contains lauryldiethanolamide and diethanolamine Antistatic agent HS15N manufactured by Kao Co., Ltd.

When preparing the inorganic substance powder-filled resin composition and molding it into a test piece, the melt flowability of the resin composition, the appearance of the molded sample, and the like were evaluated according to the following criteria.
(Liquidity)
-◎: The kneading / extrusion operation proceeded extremely smoothly, and a test piece having a uniform thickness could be easily molded even during injection molding.
-○: It was possible to mold a test piece having a uniform thickness without uneven distribution of the inorganic substance powder.
-Δ: Uneven distribution of the inorganic substance powder was observed, or it was difficult to form a uniform test piece.
-X: Extrusion molding was not possible due to a significant increase in viscosity during kneading.
(Sample appearance, etc.)
-○: Rough skin (fine wrinkles and protrusions), unevenness, scratches, and bleeding of raw material components were not observed on the surface of the test piece, and the test piece had good smoothness.
-Δ: Rough skin, unevenness, or bleeding was slightly generated on the surface.
-X: Rough skin, unevenness, or bleeding was conspicuous on the surface.

Using each of the molded test pieces, the flexibility and tensile properties were evaluated by the following methods, and in some examples, the Charpy impact strength was further evaluated.
(Flexibility test)
The above test piece was bent by hand and the flexibility was evaluated according to the following criteria.
-◎: The test piece was bent 5 times to around 160 °, but did not break.
〇: The test piece did not break unless it was bent 2-3 times to around 160 °.
-Δ: When the test piece was bent by about 120 ° or more, it broke at one time.
-X: When the test piece was bent by about 90 to 120 °, it broke at one time.
(Tensile characteristics)
The tensile elastic modulus and the elongation at break point were measured using an autograph AG-100kNXplus (Shimadzu Corporation) under the conditions of 23 ° C. and 50% RH according to JIS K 7161-2: 2014. The stretching speed was 10 mm / min.
(Charpy impact strength)
A test piece having an size of 80 mm × 10 mm was injection-molded in the same manner as the above-mentioned dumbbell-shaped test piece, and measured according to ISO179 / 1eA.

[Example 1]
25 parts by mass of PR1 (propylene homopolymer), 75 parts by mass of CC1 (heavy calcium carbonate), 0.3 parts by mass of A1 (antistatic agent), 0.04 parts by mass of HP1 (hindered phenol compound) and P1. 0.10 parts by mass of (phosphite compound) was put into a HK-25D (φ25 mm, L / D = 41) doublic rotation twin-screw kneading extruder manufactured by Parker Corporation, and the cylinder temperature was 190 to 200 ° C. Pellets were prepared by extruding the strands, cooling and cutting. Next, the pellets were put into an injection molding machine, and dumbbell-shaped test pieces were molded and subjected to various evaluation tests. The evaluation results are shown in Table 1 below.

[Examples 2 to 3, Comparative Examples 1 to 12]
Resin compositions and the like were prepared according to the same formulations and conditions as in Example 1 except that the types and amounts of raw materials were changed as shown in Table 1 described later, molded into test pieces, and subjected to various evaluation tests. .. Further, 0.3 parts by mass of A2 was used as the antistatic agent instead of A1, and the same operations as in Example 1 and Comparative Example 1 were performed (Example 3 and Comparative Example 12). The composition and evaluation results of each sample are shown in Table 1.

The heavy calcium carbonate CC1 has a reinforcing property due to its fine particle size, but tends to increase the melt viscosity of the resin composition. Therefore, in Comparative Example 1, the viscosity increased significantly during kneading, and extrusion itself could not be performed. On the other hand, according to the present invention, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris (2,4-di-tert-butylphenyl) phosphite. The resin compositions of Examples 1 and 2 containing the above in small amounts were good in moldability, excellent in flexibility, and good in tensile properties. In the compositions of Comparative Examples 2 to 9 in which HP2 and HP3 having different chemical structures or P2 and P3 are blended as a hindered phenol compound or a phosphite compound, excellent processing such as a composition in which HP1 and P1 are combined is excellent. No sex or physical properties were expressed. The processability and physical properties could be improved by blending sodium alkanesulfonate S, but they were inferior to the resin compositions of Examples 1 and 2, and a slight odor was perceived from the molded sample. (Comparative example 10). Further, although the flowability and flexibility during molding were improved by blending the plasticizer DOP, the appearance was deteriorated and the tensile properties were deteriorated due to the bleeding of the DOP (Comparative Example 11). When triethanolamine A1 was used as an antistatic agent, better evaluation results were obtained than when lauryldiethanolamide A2 was added (Example 3).

[Examples 4 to 16, Comparative Examples 13 to 17]
20 parts by mass of PR1 as a polypropylene resin, 80 parts by mass of heavy calcium carbonate CC3 as an inorganic substance powder, 0.5 parts by mass of A3 as an antistatic agent, and the ratio of the hindered phenol compound HP1 to the phosphite compound P1. The same operation as in Example 1 was performed except that the above was changed as shown in Table 2. Table 2 shows the composition and evaluation results of each resin composition.

According to the present invention, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane is 0.01% by mass or more and 0.10% by mass or less, and Tris (2, The inorganic substance powder-filled resin compositions of Examples 4 to 16 containing 4-di-tert-butylphenyl) phosphite in a proportion of 0.02% by mass or more and 0.20% by mass or less are all processable and flexible. It was excellent in terms of mechanical properties such as property (flexibility) and impact strength. In particular, Examples 11 to 13 in which the content of the hindered phenol compound is 0.01% by mass or more and 0.07% by mass or less and the content of the phosphite compound is 0.08% by mass or more and 0.17% by mass or less. And in Examples 15 to 16, extremely excellent processability was exhibited. On the other hand, in Comparative Examples 16 and 17 in which about 0.3 parts by mass of the hindered phenol compound and the phosphite compound were used in total, the results were inferior in moldability and flexibility (flexibility). It became clear that the content of hindered phenol compounds and phosphite compounds is not good if it is high.

[Example 17, Comparative Example 18]
20 parts by mass of PR1 (polypropylene resin), 70 parts by mass of CC2 (heavy calcium carbonate), 0.5 parts by mass of A3 (antistatic agent), and 0.04 or 0 parts by mass of HP1 (hindered phenol compound). And P1 (phosphite compound P1) 0.12 or 0 parts by mass were melt-kneaded by the same operation as in Example 1 to prepare a first pellet. Further, 90.66 parts by mass or 90.5 parts by mass of the first pellet and 10 parts by mass of PR1 are melt-kneaded and injection-molded under the same conditions as in Example 1 to prepare test pieces, and various types are prepared. An evaluation test was conducted. The composition and evaluation results of each resin composition are shown in Table 3.

[Examples 18 to 26, Comparative Examples 19 to 27]
Using the raw materials shown in Table 3, the final compounding amount was 30 parts by mass of the polypropylene resin, 70 parts by mass of the inorganic substance powder, and 0.5 part by mass of A3 (antistatic agent), and then the hindered phenol compound HP1. The same operation as in Example 17 was carried out with 0.04 or 0 parts by mass and 0.12 or 0 parts by mass of the phosphite compound P1. The composition and evaluation results of each resin composition are shown in Table 3.

According to the present invention, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris (2,4-di-tert-butylphenyl) phosphite are used. It has been clarified that the compounding improves the processability and physical properties of the inorganic substance powder-filled resin composition regardless of the type of the polypropylene-based resin or the inorganic substance powder. In particular, Examples 17 to 24 in which the propylene-based resin is polypropylene homopolymer and Examples 17 to 24 in which the inorganic substance powder is heavy calcium carbonate, among which two varieties having different average particle diameters are blended as heavy calcium carbonate. The resin composition of Example 24 was extremely excellent in both processability and physical properties.

From the above, even in the case of a resin composition highly filled with an inorganic substance powder, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris ( By containing 2,4-di-tert-butylphenyl) phosphite in small amounts, it is possible to produce a molded product having excellent molding processability and a good surface appearance, and has good mechanical properties, particularly resistance. It has been clarified that an inorganic substance powder-filled resin composition having impact resistance and excellent flexibility, and a molded product made of such a resin composition are provided.

Claims (9)

In an inorganic substance powder-filled resin composition containing a thermoplastic resin and an inorganic substance powder in a mass ratio of 45:55 to 10:90.
The thermoplastic resin has a propylene homopolymer of 90% by mass or more with respect to the thermoplastic resin (however, the mesopentad fraction (mm mm) is 0.2 to 0.6, and the racempentad fraction (rrrrr). ) And (1-mmmm) are polypropylene-based resins containing the following relationship: [rrrr / (1-mmmm)] ≤0.1).
0.01% by mass or more of tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane with respect to 100 parts by mass of the inorganic substance powder-filled resin composition. It contains 0.10% by mass or less and tris (2,4-di-tert-butylphenyl) phosphite in a proportion of 0.02% by mass or more and 0.20% by mass or less .
The tris (2,4-di-tert-butylphenyl) phosphite is contained in an amount of 0.08% by mass or more and 0.17% by mass or less with respect to 100 parts by mass of the inorganic substance powder-filled resin composition.
Inorganic substance powder-filled resin composition. 0.01% by mass of the tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane with respect to 100 parts by mass of the inorganic substance powder-filled resin composition. The inorganic substance powder-filled resin composition according to claim 1, which is contained in a proportion of 0.07% by mass or less. The mass of the tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and the tris (2,4-di-tert-butylphenyl) phosphite. The inorganic substance powder-filled resin composition according to claim 1 or 2 , which contains a ratio of 1.0: 1.5 to 1.0: 8.0. The inorganic substance powder-filled resin composition according to any one of claims 1 to 3 , wherein the inorganic substance powder is calcium carbonate. The inorganic substance powder-filled resin composition according to any one of claims 1 to 4 , wherein the inorganic substance powder is heavy calcium carbonate. The inorganic substance powder-filled resin according to claim 5 , wherein the heavy calcium carbonate is heavy calcium carbonate particles having an average particle diameter of 0.7 μm or more and 6.0 μm or less by an air permeation method according to JIS M-8511. Composition. A molded product comprising the inorganic substance powder-filled resin composition according to any one of claims 1 to 6 . The molded product according to claim 7 , wherein the molded product is an injection molded product. The molded product according to claim 7 , wherein the molded product is an extruded product.