Resin composition and molded article of the same

Abstract

To provide a resin composition which can be easily molded through injection molding and from which a white molded article having excellent discoloration resistance, mechanical strength, and surface smoothness can be obtained.SOLUTION: A white resin composition comprises a partially fluorinated fluororesin (A), particles (B) in which titanium oxide is the main component, a phosphorus compound (C), and a potassium titanate whisker (D), wherein the partially fluorinated fluororesin (A) has a melting point of 150-300°C, the potassium titanate whisker (D) has a fiber diameter of less than 9 μm and a Mohs' hardness of 6 or less, and with respect to the total mass of the partially fluorinated fluororesin (A), the particles (B), the phosphorus compound (C), and the potassium titanate whisker (D), the contained amounts of the particles (B), the phosphorus compound (C), and the potassium titanate whisker (D) are 1.0-20.0 mass%, 0.1-1.0 mass%, and 5-30 mass%, respectively, the resin composition having a melt flow rate of 11 g / 10 min or more and a tensile elastic modulus of 2.0 GPa or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a molded article thereof. [Background technology]

[0002] Resin molded articles are used as housings for various electronic devices. For these applications, the resin molded articles are required to have mechanical strength, such as bending strength, to prevent cracks or chips from occurring in the housing when subjected to impact. From the viewpoint of mechanical strength, ABS resin is commonly used as the resin for the resin molded articles. Furthermore, from the viewpoint of aesthetics, the resin molded articles may be made white by incorporating a white pigment, such as titanium oxide, into the resin molded articles. However, resin molded products made from ABS resin have the problem of being easily discolored by light and heat, and discoloration is particularly noticeable in white products.

[0003] On the other hand, a resin film made of a resin composition containing fluororesin, particles mainly composed of titanium oxide, a phosphorus compound, and silicone oil is known as a white resin film with excellent weather resistance (Patent Document 1). However, the resin composition described in Patent Document 1 does not have sufficient mechanical strength.

[0004] A commonly known method for increasing the mechanical strength of a resin composition is to incorporate reinforcing fibers such as glass fibers. However, when a resin composition contains reinforcing fibers, the surface appearance of the resulting molded article is impaired. In addition, although injection molding is preferred as a molding method for molded articles from the viewpoint of productivity, a high content of reinforcing fibers makes injection molding difficult. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 069482 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a resin composition that can be easily molded by injection molding to give a white molded article that is excellent in discoloration resistance, mechanical strength, and surface smoothness, and a molded article made from the resin composition. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A white resin composition comprising a partially fluorinated fluororesin (A), particles (B) mainly composed of titanium oxide, a phosphorus compound (C), and potassium titanate whiskers (D), The partially fluorinated fluororesin (A) has a melting point of 150 to 300°C, The potassium titanate whiskers (D) have a fiber diameter of less than 9 μm and a Mohs hardness of 6 or less, the particles (B) account for 1.0 to 20.0 mass%, the phosphorus compound (C) for 0.1 to 1.0 mass%, and the potassium titanate whiskers (D) for 5 to 30 mass%, based on the total mass of the partially fluorinated fluororesin (A), the particles (B), the phosphorus compound (C), and the potassium titanate whiskers (D); A melt flow rate of 11 g / 10 min or more measured at 297°C in accordance with ASTM D3159, A resin composition having a tensile modulus of 2.0 GPa or more measured at 23±1°C in accordance with ASTM D638. [2] The resin composition according to [1] above, which is for injection molding. [3] The resin composition according to the above [1] or [2], wherein the phosphorus compound (C) is at least one compound selected from the group consisting of a phosphonite compound (C1) represented by the following formula (1) and having a molecular weight of 600 to 1,500, a phosphonate compound (C2) represented by the following formula (2) and having a molecular weight of 400 to 1,500, a phosphate compound (C3) represented by the following formula (3) and having a molecular weight of 400 to 1,500, and a phosphite compound (C4) represented by the following formula (4) and having a molecular weight of 400 to 1,500. [ka] In formula (1), R 11 ~R 14 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 15 represents a divalent hydrocarbon group. 21 ~R 24 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 25 represents a divalent hydrocarbon group. 31 ~R 34 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 35 represents a divalent hydrocarbon group. 41 and R 42 each independently represents an alkyl group or an aryl group which may have an alkyl group. [4] The resin composition according to any one of [1] to [3] above, wherein the partially fluorinated fluororesin (A) comprises a copolymer having units based on ethylene and units based on tetrafluoroethylene. [5] The mass percentage of the potassium titanate whiskers (D) relative to the total mass of the resin composition is r D When the above r D is divided by the melt flow rate (g / 10 min) is 0.45 to 3.0, D and the melt flow rate (g / 10 min) are multiplied to yield a value of 200 to 350. [6] A molded article obtained by molding the resin composition according to any one of [1] to [5] above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin composition that can be easily molded by injection molding to give a white molded article that is excellent in discoloration resistance, mechanical strength, and surface smoothness, and a molded article made from the resin composition. DETAILED DESCRIPTION OF THE INVENTION

[0009] The meanings and definitions of terms used in the present invention are as follows. The term "unit based on a monomer" is a general term for an atomic group formed directly by polymerizing one monomer molecule, and an atomic group obtained by chemically converting a part of the atomic group. "Monomer" means a compound having a polymerizable carbon-carbon double bond. A unit based on a monomer may also be simply referred to as a “monomer unit.” For example, a unit based on ethylene may also be referred to as an “ethylene unit.” The "melting point" is the temperature corresponding to the maximum value of the melting peak measured by differential scanning calorimetry (DSC). "Melt flow rate" (hereinafter also referred to as "MFR") is a melt mass flow rate measured in accordance with ASTM D3159. The MFR measurement conditions are a temperature of 297°C and a load of 5 kg. "Specific gravity" is measured by the water displacement (suspension) method at 23±1°C. "Tensile strength," "tensile elongation," and "tensile modulus" are measured in accordance with ASTM D638. Specifically, an ASTM Type I dumbbell-shaped test piece (4 mm thick) is prepared from a sample (resin composition), and a tensile test is performed on the obtained test piece under conditions in accordance with ASTM D638 to determine the values. The "flexural strength" and "flexural modulus" are measured in accordance with ASTM D790. Specifically, a test piece having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm is prepared from a sample (resin composition), and the obtained test piece is subjected to a bending test under conditions in accordance with ASTM D790 to determine the flexural strength and flexural modulus. The "Izod impact strength" is measured in accordance with JIS K7110. Specifically, a test piece (with a notch) having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm is prepared from a sample (resin composition), and the obtained test piece is subjected to an Izod impact test under conditions in accordance with JIS K7110 to determine the Izod impact strength. The symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0010] [Resin composition] A resin composition according to one embodiment of the present invention (hereinafter also referred to as "the resin composition") is a white resin composition containing a partially fluorinated fluororesin (A) (hereinafter also referred to as "component (A)"), particles (B) mainly composed of titanium oxide, a phosphorus compound (C) (hereinafter also referred to as "component (C)"), and potassium titanate whiskers (D) (hereinafter also referred to as "component (D)"). Each component will be described in detail below. The present resin composition may further contain other components in addition to those described above.

[0011] The mass ratio of particles (B) to the total mass of component (A), particles (B), component (C), and component (D) is 1.0 to 20.0 mass%, preferably 1.5 to 10.0 mass%, and more preferably 2.0 to 6.0 mass%. When particles (B) are at least the lower limit, the color fastness is excellent, and when particles (B) are at most the upper limit, the particles (B) are easily dispersed in component (A), and the mechanical strength and surface smoothness are excellent.

[0012] The mass proportion of component (C) relative to the total mass of component (A), particles (B), component (C), and component (D) is 0.1 to 1.0 mass%, preferably 0.1 to 0.7 mass%, and more preferably 0.1 to 0.3 mass%. When component (C) is at least the lower limit, excellent discoloration resistance is achieved, and when it is at most the upper limit, generation of unpleasant odors during molding can be suppressed.

[0013] The mass proportion of component (D) relative to the total mass of component (A), particles (B), component (C), and component (D) is 5 to 30 mass%, preferably 7.5 to 25 mass%, more preferably 10 to 20 mass%. When component (D) is at least the lower limit, the mechanical strength and whiteness are excellent, and when it is at most the upper limit, the surface smoothness and injection moldability are excellent.

[0014] The total mass proportion of particles (B), component (C) and component (D) relative to the total mass of component (A), particles (B), component (C) and component (D) is preferably 4.0 to 45 mass%, more preferably 8 to 35 mass%, and even more preferably 13 to 25 mass%.

[0015] The total mass proportion of component (A), particles (B), component (C) and component (D) relative to the total mass of the resin composition is preferably 50 mass% or more, more preferably 75 mass% or more, and may be 100 mass%.

[0016] The MFR of this resin composition measured at 297°C is 11 g / 10 min or more, preferably 13 g / 10 min or more, more preferably 15 g / 10 min or more, and preferably 34 g / 10 min or less, more preferably 28 g / 10 min or less. The lower limit and the upper limit can be combined as appropriate. When the MFR is equal to or greater than the lower limit, the fluidity during injection molding is high and the injection moldability is excellent. When the MFR is equal to or less than the upper limit, the generation of flash during injection molding can be suppressed.

[0017] In the present resin composition, the mass percentage of component (D) relative to the total mass of the present resin composition is represented by r D When r D is divided by the MFR (g / 10 min) of the resin composition (r D / MFR) is 0.45 to 3.0, and r D and the MFR (g / 10 min) of the resin composition (r D × MFR) is preferably 200 to 350. r D When the / MFR is equal to or greater than the lower limit, the mechanical strength tends to be excellent, and when it is equal to or less than the upper limit, the injection moldability tends to be excellent. D When the ×MFR is equal to or greater than the lower limit, the mechanical strength tends to be excellent, and when it is equal to or less than the upper limit, the tensile modulus and flexural modulus tend to be excellent. r D The / MFR is preferably from 0.45 to 2.8, more preferably from 0.48 to 1.4. r D The ×MFR is preferably 200 to 330, and more preferably 210 to 300.

[0018] The tensile modulus of the resin composition measured at 23±1°C is 2.0 GPa or more, preferably 2.2 GPa or more, and more preferably 3.0 GPa or more. If the tensile modulus is equal to or greater than the lower limit, the resin composition has excellent mechanical strength. The upper limit of the tensile modulus is not particularly limited, but is, for example, 5.0 GPa.

[0019] The tensile strength of the resin composition measured at 23±1° C. is preferably 36 MPa or more, more preferably 39 MPa or more, and even more preferably 50 MPa or more, from the viewpoint of mechanical strength. The upper limit of the tensile strength is not particularly limited, but is, for example, 60 MPa.

[0020] The tensile elongation of the resin composition measured at 23±1° C. is preferably 12% or more, more preferably 21% or more, and even more preferably 40% or more, from the viewpoint of mechanical strength. The upper limit of the tensile elongation is not particularly limited, but is, for example, 300%.

[0021] The flexural modulus of the resin composition measured at 23±1° C. is preferably 2.0 GPa or more, more preferably 3.0 GPa or more, and even more preferably 4.0 GPa or more, from the viewpoint of mechanical strength. The upper limit of the flexural modulus is not particularly limited, but is, for example, 8.0 GPa.

[0022] The flexural strength of the resin composition measured at 23±1° C. is preferably 30 MPa or more, more preferably 45 MPa or more, and even more preferably 60 MPa or more, from the viewpoint of mechanical strength. The upper limit of the flexural strength is not particularly limited, but is, for example, 101 MPa.

[0023] From the viewpoint of impact resistance, the Izod impact strength of the resin composition measured at 23±1° C. is preferably 90 J / m or more, more preferably 110 J / m or more, and even more preferably 300 J / m or more. The upper limit of the Izod impact strength is not particularly limited, and may be, for example, NB (No break).

[0024] <Component (A)> Component (A) is a partially fluorinated fluororesin. As component (A), known materials can be used, such as a copolymer having ethylene units and tetrafluoroethylene (hereinafter also referred to as "TFE") units (hereinafter also referred to as "ETFE"), a polymer having vinylidene fluoride units (hereinafter also referred to as "PVDF"), and a copolymer having ethylene units and chlorotrifluoroethylene units. These polymers may be used alone or in combination of two or more.

[0025] As the component (A), ETFE is preferred because it has better mechanical strength and injection moldability. As ETFE, a copolymer having ethylene units, TFE units, and units based on other monomers other than ethylene and TFE (hereinafter also referred to as "other monomer units") is preferred because it has better heat resistance, mechanical properties, and chemical resistance. The other monomers may be any monomers as long as they are copolymerizable with ethylene and TFE, and one type may be used alone, or two or more types may be used in combination.

[0026] Examples of other monomer units include units based on the following monomers (1) to (7): The following monomers (1) to (7) can be used singly or in combination of two or more. (1) A compound represented by the following formula 1: CH2=CX(CF2) n Z expression 1 Here, X and Z each independently represent a hydrogen atom or a fluorine atom, and n represents an integer of 1 to 10. (2) Olefins such as propylene, butene, and isobutylene (excluding ethylene). (3) Fluoroolefins that do not have a hydrogen atom in the unsaturated group, such as hexafluoropropylene (HFP) and chlorotrifluoroethylene (CTFE) (excluding TFE). (4) Fluoroolefins having a hydrogen atom in an unsaturated group, such as vinylidene fluoride (VDF), vinyl fluoride (VF), trifluoroethylene, and hexafluoroisobutylene (HFIB). (5) Perfluoro(alkyl vinyl ethers) (PAVEs) such as perfluoro(methyl vinyl ether) (PMVE), perfluoro(ethyl vinyl ether) (PEVE), perfluoro(propyl vinyl ether) (PPVE), and perfluoro(butyl vinyl ether) (PBVE). (6) Perfluorovinyl ethers having two unsaturated bonds, such as CF2=CFOCF2CF=CF2 and CF2=CFO(CF2)2CF=CF2. (7) Fluorine-containing monomers having an aliphatic ring structure, such as perfluoro(2,2-dimethyl-1,3-dioxole) (PDD), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, and perfluoro(2-methylene-4-methyl-1,3-dioxolane).

[0027] Among these, it is preferable to have a unit based on the compound represented by the formula 1 (hereinafter also referred to as "FAE"), since this provides better mechanical properties and thermal stability. X in formula 1 is preferably a hydrogen atom, as this provides better flexibility, elongation, and strength. Z in formula 1 is preferably a fluorine atom in view of further improving heat resistance and chemical resistance. In formula 1, n is preferably 2 to 8, more preferably 2 to 6, and even more preferably 2, 4, or 6. When n is at least the lower limit, the mechanical properties and thermal stability of the resin composition are even more excellent, and when n is at most the upper limit, the FAE has sufficient polymerization reactivity.

[0028] Specific preferred examples of FAE include CH2=CH(CF2)2F, CH2=CH(CF2)4F, CH2=CH(CF2)6F, CH2=CF(CF2)4F, CH2=CF(CF2)3H, etc. Among them, CH2=CH(CF2)4F (hereinafter also referred to as PFBE) is preferred because it has even more excellent mechanical properties and thermal stability. The FAE may be used alone or in combination of two or more.

[0029] In ETFE, the molar ratio of E units to TFE units (E units / TFE units) is preferably 30 / 70 to 60 / 40, more preferably 35 / 65 to 60 / 40. When the E units / TFE units is equal to or greater than the lower limit, the melting point of ETFE is sufficiently high and the heat resistance and rigidity at high temperatures are excellent, and when it is equal to or less than the upper limit, the chemical resistance is excellent.

[0030] The proportion of the other monomer units is preferably 0.7 to 5.0 mol %, more preferably 0.9 to 4.0 mol %, based on the total units constituting ETFE. When the proportion of the other monomer units is equal to or greater than the lower limit, the stress crack resistance at high temperatures is further improved, and when it is equal to or less than the upper limit, the melting point of ETFE is sufficiently high, and the heat resistance and rigidity at high temperatures are excellent.

[0031] Component (A) has a melting point of 150 to 300° C. If the melting point of component (A) is 150° C. or higher, the heat resistance is excellent, and if it is 300° C. or lower, the injection moldability of the resin composition is excellent. The melting point of component (A) is preferably 170 to 290° C., more preferably 200 to 280° C.

[0032] The melting point of component (A) can be adjusted by the proportion of the monomer units, etc. For example, in the case of ETFE, the melting point can be adjusted by the molar ratio of E units to TFE units, the ratio of other monomer units to all units constituting ETFE, etc. Specifically, to increase the melting point of ETFE, it is thought that the crystallinity can be increased by bringing the (E / TFE) molar ratio closer to 50 / 50 and reducing the content of other monomer units. On the other hand, to lower the melting point, it is thought that the crystallinity can be decreased by increasing the content of TFE units, etc., and by moving the (E / TFE) molar ratio away from 50 / 50 and increasing the content of other monomer units.

[0033] The MFR of component (A) at 297°C is preferably from 10 to 70 g / 10 min, more preferably from 20 to 60 g / 10 min, and even more preferably from 30 to 50 g / 10 min. MFR is also a measure of molecular weight, with a smaller value indicating a higher molecular weight and a larger value indicating a lower molecular weight. When the MFR of component (A) is equal to or greater than the lower limit, the MFR of the resin composition can be easily adjusted to 11 g / 10 min or more.When the MFR of component (A) is equal to or less than the upper limit, the mechanical strength is superior.

[0034] Component (A) may be a commercially available product or may be produced by a known production method, such as the method described in paragraphs

[0021] to

[0025] of Patent Document 1 or the method described in paragraphs

[0036] to

[0043] of International Publication No. 2016 / 006644.

[0035] <Particle (B)> The particles (B) are particles containing titanium oxide as a main component. By using both the particles (B) and the component (C), discoloration resistance can be improved. The phrase "particles (B) mainly comprise titanium oxide" means that the content of titanium oxide in particles (B) is 95% by mass or more, and preferably 97% by mass or more.

[0036] The particles (B) may be titanium oxide particles (containing 100% by mass of titanium oxide) or composite particles having a coating layer on the surface of titanium oxide particles. The coating layer may be single-layered or multi-layered. Examples of the coating layer include layers containing inorganic components such as silicon oxide, cerium oxide, aluminum oxide, phosphorus oxide, sodium oxide, zirconium oxide, cerium oxide, etc. For the purpose of obtaining a molded product excellent in weather resistance and appearance, the content of inorganic components having water of crystallization that leads to foaming (silicon oxide, cerium oxide, aluminum oxide, etc.) in the particles (B) is preferably 3 mass % or less. The inorganic components in the particles (B) can be quantified using a scanning X-ray fluorescence analyzer (for example, ZSX Primus II manufactured by Rigaku Co., Ltd.) using a pressed sheet of the particles (B).

[0037] The average particle size of the particles (B) is preferably 0.15 to 0.40 μm, more preferably 0.17 to 0.30 μm. When the average particle size of the particles (B) is equal to or greater than the lower limit, the dispersibility during kneading is superior. When the average particle size of the particles (B) is equal to or less than the upper limit, the specific surface area of ​​the titanium oxide is small, making it difficult for photoactivity to be exhibited, and thus providing superior discoloration resistance. In this specification, the average particle size is the average value of particle sizes measured using an electron microscope for 20 particles randomly selected.

[0038] The particles (B) may be commercially available products or may be produced by a known production method. Examples of commercially available products that can be used as particles (B) include R101, R102, R103, and R104 manufactured by DuPont; RCL-69 and TiONA188 manufactured by Millennium; 2230 and 2233 manufactured by Cronos; CR-50 and CR-63 manufactured by Ishihara Sangyo Kaisha; and CR470 manufactured by Tronox. According to the manufacturer's analysis, the pure titanium oxide content of each product is 96% by mass or more.

[0039] <Ingredient (C)> Component (C) is a phosphorus compound. Examples of the component (C) include phosphonite compounds, phosphonate compounds, phosphate compounds, and phosphite compounds.

[0040] An example of the phosphonite compound is a phosphonite compound (C1) represented by the following formula (1) and having a molecular weight of 600 to 1,500.

[0041] [ka] In formula (1), R 11 ~R 14 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 15 represents a divalent hydrocarbon group.

[0042] In formula (1), R 11 ~R 14The alkyl group in may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group may be within a range such that the molecular weight of the phosphonite compound (C1) is 600 to 1,500, and preferably 1 to 18. R 11 ~R 14 Examples of the aryl group in (a) include monocyclic aryl groups such as a phenyl group, condensed polycyclic aryl groups such as a naphthyl group, and linked polycyclic aryl groups. A linked polycyclic aryl group refers to a monovalent group in which monocyclic or condensed polycyclic aromatic rings are linked directly or via an alkylene group or the like. The aryl group may have an alkyl group, and the alkyl group may be linear, branched, or cyclic, but preferably has 1 to 8 carbon atoms. R 11 ~R 14 may be the same or different. R 11 ~R 14 Among the above, an aryl group which may have an alkyl group is preferable, and a phenyl group which may have an alkyl group is more preferable.

[0043] R 15 Examples of the divalent hydrocarbon group in the formula include an alkylene group and an arylene group. The alkylene group may be linear, branched, or cyclic. The number of carbon atoms in the alkylene group may be within a range such that the molecular weight of the phosphonite compound (C1) is 600 to 1,500, and is preferably 1 to 30. Of these, the number of carbon atoms in a cyclic alkylene group (cycloalkylene group) is more preferably 5 to 12. Examples of arylene groups include monocyclic arylene groups such as phenylene groups, condensed polycyclic arylene groups such as naphthylene groups, and linked polycyclic arylene groups. The term "linked polycyclic arylene group" refers to a divalent group in which monocyclic or condensed polycyclic aromatic rings are linked directly or via an alkylene group or the like. The alkylene group linking the aromatic rings is preferably an alkylene group having 6 or less carbon atoms. The arylene group may also have an alkyl group. Examples of the linked polycyclic arylene group include biarylene groups such as a biphenylene group represented by the following formula (15-1), and linked polycyclic arylene groups represented by the following formula (15-2). R 15 As the alkyl group, an arylene group is preferred, a phenylene group, a biphenylene group, and a linked phenylene group in which phenylene groups are linked via an alkylene group are more preferred, and a biphenylene group is particularly preferred.

[0044] [ka]

[0045] The molecular weight of the phosphonite compound (C1) is 600 to 1,500, and more preferably 1,000 to 1,500. The molecular weight is related to the decomposition temperature of the phosphonite compound (C1). A molecular weight of 600 or more has a sufficiently high decomposition temperature, which makes it difficult for decomposition gas to be generated during the compounding and molding processes, resulting in an excellent working environment. Furthermore, when the molecular weight is within the above range, the phosphonite compound (C1) has an excellent effect of suppressing the photoactivity of titanium oxide. This is thought to be because the phosphonite compound (C1) is uniformly oriented on the titanium oxide. Furthermore, the phosphonite compound (C1) itself is unlikely to aggregate and generate foreign matter. The phosphorus atom content (proportion of the mass of phosphorus atoms relative to the total mass of all atoms (100 mass%)) of the phosphonite compound (C1) is preferably about 4 to 12%.

[0046] Specific examples of the phosphonite compound (C1) include a compound represented by the following formula (1-1) (tetrakis(2,4-di-t-butyl-5-methylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonite, molecular weight: 1,092, melting point: 234 to 240°C) and a compound represented by the following formula (1-2) (tetrakis(2,4-di-tert-butylphenyl){1,1-biphenyl}-4,4'-diylbisphosphonite, molecular weight: 1,035, melting point: 93 to 99°C).

[0047] [ka]

[0048] The phosphonite compound (C1) may be a commercially available product or may be synthesized by a known manufacturing method. For example, the compound represented by formula (1-1) is available as "GSY-P101" manufactured by Osaki Kogyo Kagaku Co., Ltd. The compound represented by formula (1-2) is available as "Irgafos P-EPQ" manufactured by Ciba Specialty Chemicals.

[0049] An example of the phosphonate compound is a phosphonate compound (C2) represented by the following formula (2) and having a molecular weight of 400 to 1,500.

[0050] [ka] In formula (2), R 21 ~R 24 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 25 represents a divalent hydrocarbon group.

[0051] In formula (2), R 21 ~R 24 The alkyl group and the aryl group optionally having an alkyl group in 11 ~R 14 Examples of the alkyl group and the aryl group optionally having an alkyl group in the above formula (1) include the same groups as those in the above formula (1) and (2). R 21 ~R 24 may be the same or different. R 21 ~R 24 Among the above, an aryl group which may have an alkyl group is preferable, and a phenyl group which may have an alkyl group is more preferable. R 25 As the divalent hydrocarbon group in 15 Examples of the divalent hydrocarbon group include the same groups as the divalent hydrocarbon group in the above. R 25As the alkylene group, an arylene group is preferred, and among these, a phenylene group, a biphenylene group, and a linked phenylene group in which phenylene groups are linked via an alkylene group are more preferred, and a biphenylene group is particularly preferred.

[0052] The molecular weight of the phosphonate compound (C2) is 400 to 1,500, and more preferably 900 to 1,500. The molecular weight is related to the decomposition temperature of the phosphonate compound (C2). A molecular weight of 400 or more has a sufficiently high decomposition temperature, which makes it difficult for decomposition gas to be generated during the compounding and molding processes, resulting in an excellent working environment. Furthermore, when the molecular weight is within the above range, the effect of suppressing the photoactivity of titanium oxide is excellent. This is thought to be due to the phosphonate compound (C2) being uniformly oriented on the titanium oxide. Furthermore, the phosphonate compound (C2) itself is unlikely to aggregate to generate foreign matter. The phosphorus atom content of the phosphonate compound (C2) is preferably about 4 to 12%.

[0053] Specific examples of the phosphonate compound (C2) include a compound represented by the following formula (2-1) (tetraethylbiphenyl-4,4'-diyldiphosphonate, molecular weight: 426) and a compound represented by the following formula (2-2) (tetradodecylbiphenyl-4,4'-diyldiphosphonate, molecular weight: 986).

[0054] [ka]

[0055] The phosphonate compound (C2) may be a commercially available product or may be synthesized by a known production method. For example, the compound represented by formula (2-2) is available from Johoku Chemical Industry Co., Ltd.

[0056] The phosphate compound may, for example, be a phosphate compound (C3) represented by the following formula (3) and having a molecular weight of 400 to 1,500.

[0057] [ka] In formula (3), R 31 ~R 34 each independently represents an alkyl group or an aryl group which may have an alkyl group, R 35 represents a divalent hydrocarbon group.

[0058] R 31 ~R 34 The alkyl group and the aryl group optionally having an alkyl group in 11 ~R 14 Examples of the alkyl group and the aryl group optionally having an alkyl group in the above formula (1) include the same groups as those in the above formula (1) and (2). R 31 ~R 34 may be the same or different. R 31 ~R 34 Among the above, an aryl group which may have an alkyl group is preferable, and a phenyl group which may have an alkyl group is more preferable. R 35 The divalent hydrocarbon groups in 15 The divalent hydrocarbon groups are the same as those in the above. R 35 As the alkyl group, an arylene group is preferred, and among these, a phenylene group, a biphenylene group, and a linked phenylene group in which phenylene groups are linked via an alkylene group are more preferred, and a phenylene group is particularly preferred.

[0059] The molecular weight of the phosphate compound (C3) is 400 to 1,500, and more preferably 600 to 1,500. The molecular weight is related to the decomposition temperature of the phosphate compound. A molecular weight of 400 or more has a sufficiently high decomposition temperature, which makes it difficult for decomposition gas to be generated during the compounding and molding processes, resulting in an excellent working environment. Furthermore, when the molecular weight is within the above range, the effect of suppressing the photoactivity of titanium oxide is excellent. This is thought to be due to the phosphate compound (C3) being uniformly oriented on the titanium oxide. Furthermore, the phosphate compound (C3) itself is unlikely to aggregate and generate foreign matter. The phosphorus atom content of the phosphate compound (C3) is preferably about 4 to 12%.

[0060] Specific examples of the phosphate compound (C3) include a compound represented by the following formula (3-1) (resorcinol bis-diphenyl phosphate, molecular weight: 687), a compound represented by the following formula (3-2) (resorcinol bis-dixylenyl phosphate, molecular weight: 879), and bisphenol A bis-diphenyl phosphate.

[0061] [ka]

[0062] The phosphate compound (C3) may be a commercially available product or may be synthesized by a known production method. For example, the compound represented by formula (3-1) is available as "aromatic condensed phosphate ester 733S" manufactured by Daihachi Chemical Industry Co., Ltd. The compound represented by formula (3-2) is available as "aromatic condensed phosphate ester PX200" manufactured by Daihachi Chemical Industry Co., Ltd.

[0063] An example of the phosphite compound is a phosphite compound (C4) represented by the following formula (4) and having a molecular weight of 400 to 1,500.

[0064] [ka] In formula (4), R 41 and R 42 each independently represents an alkyl group or an aryl group which may have an alkyl group.

[0065] R 41 and R 42 The alkyl group and the aryl group optionally having an alkyl group in 11 ~R 14 Examples of the alkyl group and the aryl group optionally having an alkyl group in the above formula (1) include the same groups as those in the above formula (1) and (2). R 41 and R42 may be the same or different. R 41 and R 42 Among the above, an aryl group which may have an alkyl group is preferable, and a phenyl group which may have an alkyl group is more preferable.

[0066] The molecular weight of the phosphite compound (C4) is 400 to 1,500, and more preferably 600 to 1,500. The molecular weight is related to the decomposition temperature of the phosphite compound. Molecular weights of 400 or more have a sufficiently high decomposition temperature, which makes it difficult for decomposition gases to be generated during the compounding and molding processes, resulting in an excellent working environment. Furthermore, when the molecular weight is within the above range, the effect of suppressing the photoactivity of titanium oxide is excellent. This is thought to be due to the phosphite compound (C4) being uniformly oriented on the titanium oxide. Furthermore, the phosphite compound (C4) itself is unlikely to aggregate to generate foreign matter. The phosphorus atom content of the phosphite compound (C4) is preferably about 5 to 15%.

[0067] Specific examples of the phosphite compound (C4) include phosphite antioxidants such as 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane and 3,9-dioctadecane-1-yl-2,4,8,10-tetraoxa-3,9-diphosphapyro[5.5]undecane.

[0068] The phosphite compound may be a commercially available product or may be synthesized by a known production method. For example, phosphite-based antioxidants are available as "ADEKA STAB PEP-36" and "ADEKA STAB PEP-8" manufactured by Adeka Corporation.

[0069] As the component (C), one type may be used, or two or more types may be used in combination. Among the above, in terms of discoloration resistance, at least one compound selected from the group consisting of phosphonite compounds (C1), phosphonate compounds (C2), phosphate compounds (C3) and phosphite compounds (C4) is preferred.

[0070] The melting point of component (C) is preferably equal to or lower than the melting point of component (A). For example, when component (A) has a melting point of 240°C, component (C) is preferably a phosphorus compound having a melting point of 240°C or lower.

[0071] <Ingredient (D)> Component (D) is potassium titanate whisker, which is a single crystal fiber of K2O·nTiO2 (n is 1 or more). Component (D) functions as a filler. When the resin composition contains component (D), mechanical strength such as tensile modulus, tensile strength, flexural modulus, and flexural strength is improved. Furthermore, since component (D) is white, the resin composition can be made white by including component (D).

[0072] The fiber diameter of component (D) is less than 9 μm. If the fiber diameter is less than 9 μm, the surface smoothness of the molded article will be excellent. The fiber diameter of component (D) is preferably 5 μm or less, more preferably 1 μm or less. On the other hand, from the viewpoint of injection moldability, the fiber diameter of component (D) is preferably 0.1 μm or more, more preferably 0.3 μm or more. The above upper limit and lower limit can be combined as appropriate. The fiber diameter of component (D) is determined using an electron microscope.

[0073] The fiber length of component (D) is preferably 5 to 90 μm, more preferably 10 to 50 μm, and even more preferably 10 to 20 μm. If the fiber length is equal to or greater than the lower limit, the reinforcing effect is superior, and if it is equal to or less than the upper limit, the surface smoothness is superior. The fiber length of component (D) can be determined using an electron microscope.

[0074] The Mohs hardness of component (D) is 6 or less. A Mohs hardness of 6 or less provides excellent surface smoothness. The Mohs hardness of component (D) is preferably 5.5 or less, more preferably 5 or less. On the other hand, from the viewpoint of mechanical strength, the Mohs hardness of component (D) is preferably 2 or more, more preferably 3 or more. The above upper limit and lower limit can be combined as appropriate. The Mohs hardness of component (D) is determined by a Mohs hardness scale.

[0075] Component (D) may be a commercially available product or may be produced by a known production method. Examples of commercially available products that can be used as component (D) include TISMO D, TISMO D101, and TISMO N manufactured by Otsuka Chemical Co., Ltd.

[0076] <Other ingredients> The present resin composition may contain other components in addition to those described above, as needed, to the extent that the whiteness, injection moldability, mechanical strength, etc. of the present resin composition are not significantly impaired. Examples of other components include fillers other than component (D), heat stabilizers other than the phosphorus compound (C), dispersants, mold release agents, and flame retardants.

[0077] <Method of manufacturing resin composition> The resin composition can be produced, for example, by pre-mixing the components using various mixers such as a tumbler or a Henschel mixer, and then melt-kneading them using a Banbury mixer, a roll, a Brabender mixer, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, or the like. The melt-kneading temperature is preferably 250 to 300°C, more preferably 270 to 290°C.

[0078] The resin composition described above can be easily molded by injection molding, and by molding the resin composition, a white molded article having excellent discoloration resistance, mechanical strength, and surface smoothness can be obtained. Because of the above effects, the resin composition is useful as a molding material, and is particularly suitable for use in injection molding.

[0079] [Molded body] A molded article according to one embodiment of the present invention (hereinafter also referred to as "the present molded article") is obtained by molding the present resin composition.

[0080] Examples of molding methods include compression molding (hot molding, free baking, etc.), injection molding, transfer molding, and other common methods. Among these, injection molding is preferred from the viewpoint of freedom in shape. Examples of injection molding methods include general injection molding, high-speed injection molding, multi-color molding, coinjection molding, injection compression molding, gas-assisted injection molding, foam injection molding (MUCELL), heat-and-cool molding using a rapidly heated mold, insert molding, and in-mold decoration molding. The molding cylinder temperature is preferably 260 to 330°C, more preferably 280 to 310°C, and the mold temperature is preferably 80 to 160°C, more preferably 100 to 140°C.

[0081] The present molded article may be used as a composite by being combined or laminated with other materials than the present molded article, such as metals, glass, plastics, and rubber. Specific examples of plastics include those described in International Publication No. 2015 / 182702, liquid crystal polymers, polyaryl ketones, polyethersulfones, polyphenylsulfones, polyacetals, and polyurethanes. Examples of polyamides include polyamide 6, polyamide 66, polyamide 46, polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 6 / 66 copolymers, polyamide 6 / 66 / 610 copolymers, polyamide MXD6, polyamide 6T, polyamide 9T, and polyamide 6 / 6T copolymers.

[0082] Specific forms and applications of the present molded body and composite include, for example, housings for portable electronic devices, connecting members for portable electronic devices, sliding members, three-dimensional circuit components, gears, actuators, pistons, bearings, aircraft interior materials, bushings, tubes (for fuel, etc.), hoses, tanks, seals, wires, insulating coating materials for electric wires (wires, cables, etc.), films, sheets, bottles, and fibers.

[0083] Examples of portable electronic devices include mobile phones, personal digital assistants, laptop computers, tablet computers, radios, cameras, camera accessories, watches, calculators, earphones, music players, global positioning system receivers, portable games, hard drives, portable recording devices, portable playback devices, and portable radio receivers.

[0084] Examples of the housing of a portable electronic device include a back cover, a front cover, an antenna housing, a frame, and a backbone of the portable electronic device. The housing may be a single component of the molded article or a multi-component component. Here, the backbone is a component to which the components of the portable electronic device, such as electronics, a microprocessor, a screen, a keyboard, a keypad, an antenna, and a battery socket, are attached. When the housing is inside the portable electronic device, the housing may not be visible from the outside of the portable electronic device, or may be partially visible from the outside of the portable electronic device. The housing, such as a cover for protecting and supporting the internal structure, may be exposed to the outside of the portable electronic device.

[0085] Examples of the form of the coupling member for a portable electronic device include a snap-type connector between a circuit board, a microphone, a speaker, a display, a battery, a cover, an electrical connector, an electronic connector, a hinge, an antenna, a switch, and a switch pad of the portable electronic device. The coupling member is suitably applicable to portable electronic devices such as a mobile phone, a personal digital assistant (PDA), a music storage device, a bug, a portable DVD player, an electric multimeter, a portable electronic game console, and a portable personal computer (e.g., a notebook computer).

[0086] Three-dimensional circuit components are components in which a circuit pattern is formed on the surface of a resin part molded into a three-dimensional shape, and are used as antenna parts for mobile electronic devices and parts for in-vehicle electronic devices. The circuit pattern is formed using the laser direct structuring (LDS) method, which involves etching the circuit pattern with a laser and then plating it.

[0087] Examples of uses for tubes, hoses, tanks, seals, and wires include those described in International Publication No. 2015 / 182702. Examples of uses for tubes and hoses include tubes for drilling for energy resources such as petroleum, natural gas, and shale oil. Examples of applications of insulating coating materials for electric wires include electric wires or rectangular copper wires for motor coils, and in particular, insulating coating materials for rectangular conductors in drive motors for hybrid electric vehicles (HEVs) and electric vehicles (EVs). Examples of the form of insulating coating materials for rectangular conductors include films. Examples of applications of the insulating coating material for electric wires include insulating coating materials for downhole cables used in drilling for energy resources (oil, natural gas, shale oil, etc.), and among these, insulating coating materials for downhole cables used in oil mining are preferred. Applications of films and sheets include, for example, speaker diaphragms, plates for trauma and fractures, insulating paper for various electrical insulating adhesive tapes (insulating paper for motors, etc.), sealing tape for oil and natural gas pipes, and release films.

[0088] When the molded article is a film, its applications include speaker diaphragms, wire coating films, flexible printed circuit boards, rigid substrates, coverlays, housings for electronic devices, heat-resistant rolls for office automation equipment, and films for impregnating other fiber composites. The film thickness is preferably 1 to 100 μm, more preferably 2 to 80 μm, and even more preferably 5 to 50 μm. When the film thickness is at least the lower limit of the above range, the strength of the film is improved. When the film thickness is at most the upper limit of the above range, the film has excellent handleability. When the molded article is a tube, its applications include medical catheters equipped with a tube, electrical wire coating, and piping for analytical equipment. When the molded article is a fiber, its applications include protective clothing and various filters. [Example]

[0089] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Examples 1 and 5 to 8 are comparative examples, and Examples 2 to 4 are working examples.

[0090] (Evaluation method) <Melting point> Using a differential scanning calorimeter (Seiko Instruments Inc.), the resin was heated at a rate of 10°C / min, and the melting peak was recorded, and the temperature corresponding to the maximum value was taken as the melting point.

[0091] <Specific gravity> The specific gravity was measured at 23±1°C by the water displacement (suspension) method.

[0092] <mfr> The melt indexer (manufactured by Techno Seven Co., Ltd.) was used and measurements were performed in accordance with ASTM D3159 at a temperature of 297°C and a load of 5 kg.

[0093] <Preparation of injection molded articles for evaluation> The resin composition was injection molded using an injection molding machine (ROBOSHOT α-50, manufactured by Fanuc Corporation) at a cylinder temperature of 120°C and a mold temperature of 120°C to obtain an ASTM D638 Type I injection-molded article for evaluation, 4 mm thick.

[0094] <Tensile strength, tensile elongation, tensile modulus> Test specimens were cut from the injection-molded articles for evaluation, and the tensile strength, tensile elongation, and tensile modulus of these test specimens were measured at 23±1°C using a TENSILON (manufactured by A&D Co., Ltd., model RTF-1350) in accordance with ASTM D638 under the conditions of a load cell rating of 10 kN, a chuck distance of 115 mm, and a speed of 50 mm / min.

[0095] <Flexural strength, flexural modulus> Test pieces measuring 80 mm in length and 10 mm in width were cut out from the injection-molded articles for evaluation. The flexural strength and flexural modulus of these test pieces were measured at 23±1°C using a TENSILON (A&D Corporation, RTF-1350) in accordance with ASTM D790 under the following conditions: load cell rating 10 kN, support distance 64 mm, and speed 2 mm / min.

[0096] <Izod impact strength> A test piece measuring 80 mm in length and 10 mm in width was cut from the injection-molded article for evaluation, and a notch was made at a position 40 mm above the test piece. The Izod impact strength of this test piece was measured at 23±1°C using an Izod tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) in accordance with JIS K 7110 under the following conditions: hammer capacity 2.75 J, hammer load 13.97 N, distance from the shaft center to the center of gravity 10.54 cm, and distance from the shaft center to the impact point 33.5 cm.

[0097] <Injection moldability> From the measurement results of the MFR of the resin composition, the injection moldability was evaluated according to the following criteria: The larger the MFR, the better the injection moldability. ○: MFR is 12g / 10min or more. △: MFR is 8g / 10min or more and less than 12g / 10min. ×: MFR is less than 8 g / 10 min.

[0098] <Surface smoothness> The arithmetic mean roughness Ra of the surface of the injection molded product for evaluation was measured using a contact surface roughness measuring instrument (Surfcom manufactured by Tokyo Seimitsu Co., Ltd.) in accordance with JIS B0601: 1994 under the conditions of measurement length: 4.0 mm, measurement speed: 0.30 mm / s, and cutoff value λc: 0.8 mm. The smaller the Ra, the better the surface smoothness.

[0099] <Colorfastness> 2 g of the pellets were placed on a glass dish and heated at 300°C for 30 minutes, after which the pellets were visually observed and evaluated for discoloration resistance according to the following criteria. ○: No discoloration. △: Partially discolored. ×: The entire surface is discolored.

[0100] (Materials used) <Component (A)> A1: AGC "Fluon ETFE C-88AXMP", ETFE, melting point 260°C, MFR 39g / 10min. A2: AGC "Fluon ETFE C-88AXP", ETFE, melting point 260℃, MFR 11g / 10min.

[0101] <Particle (B)> B1: "Tipake CR-63" manufactured by Ishihara Sangyo Co., Ltd., titanium dioxide powder, titanium oxide content 97% by mass, average particle size 0.2 μm.

[0102] <Ingredient (C)> Reagent B: Adeka Corporation's "Adeka Stab PEP-36", a phosphite antioxidant, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, molecular weight 633.

[0103] <Ingredient (D)> D1: "Tismo D101" manufactured by Otsuka Chemical Co., Ltd., potassium titanate whisker, fiber diameter 0.3-0.6 μm, fiber length 10-20 μm, Mohs hardness 4.

[0104] <Fillers other than component (D)> E1: Nittobo "SS 05C-404S", cut glass fiber, fiber diameter 10 μm, cut length 100 μm.

[0105] (Examples 1 to 8) According to the composition (mass%) shown in Table 1, each component was kneaded in a twin-screw extruder ("KZW15TW-45MG" manufactured by Technovel Co., Ltd.) under the following conditions: resin discharge rate: 2.0 kg / hour, screw rotation speed: 100 rpm, set resin temperature: 285°C. The strand extruded from the tip of the die was air-cooled and cut with a pelletizer to obtain a pellet-shaped resin composition. The resin composition thus obtained was subjected to the above evaluations, and the results are shown in Table 1.

[0106] [Table 1]

[0107] The resin compositions of Examples 2 to 4 had a large MFR and excellent injection moldability, and the resulting molded articles were excellent in mechanical strength such as flexural modulus, surface smoothness, and discoloration resistance. On the other hand, the resin composition of Example 1, which did not contain component (D), gave molded articles that were inferior in mechanical strength such as flexural modulus and discoloration resistance. The resin composition of Example 5, in which the amount of component (D) exceeded 30 mass% relative to the total mass of component (A), particles (B), component (C), and component (D), was inferior in injection moldability and surface smoothness of the obtained molded article. The resin composition of Example 6, in which another filler was used instead of component (D) in Example 1, gave molded articles that were inferior in mechanical strength and surface smoothness. The resin composition of Example 7, in which the content of the other filler was increased compared to Example 6, improved the mechanical strength and molding shrinkage of the molded article, but further deteriorated the surface smoothness. The resin composition of Example 8, which did not contain the particles (B) and the component (C), was not white and was poor in injection moldability and discoloration resistance.< / mfr>

Claims

1. A white resin composition comprising a partially fluorinated fluororesin (A), particles (B) containing titanium oxide as a main component, a phosphorus compound (C), and potassium titanate whiskers (D), The partially fluorinated fluororesin (A) has a melting point of 150 to 300°C, The potassium titanate whiskers (D) have a fiber diameter of less than 9 μm and a Mohs hardness of 6 or less, the particles (B) account for 1.0 to 20.0 mass%, the phosphorus compound (C) for 0.1 to 1.0 mass%, and the potassium titanate whiskers (D) for 5 to 30 mass%, based on the total mass of the partially fluorinated fluororesin (A), the particles (B), the phosphorus compound (C), and the potassium titanate whiskers (D); A melt flow rate measured at 297°C in accordance with ASTM D3159 is 11 g / 10 min or more; A resin composition having a tensile modulus of 2.0 GPa or more as measured at 23±1°C in accordance with ASTM D638.

2. The resin composition according to claim 1, which is for injection molding.

3. 3. The resin composition according to claim 1, wherein the phosphorus compound (C) is at least one compound selected from the group consisting of a phosphonite compound (C1) represented by the following formula (1) and having a molecular weight of 600 to 1,500, a phosphonate compound (C2) represented by the following formula (2) and having a molecular weight of 400 to 1,500, a phosphate compound (C3) represented by the following formula (3) and having a molecular weight of 400 to 1,500, and a phosphite compound (C4) represented by the following formula (4) and having a molecular weight of 400 to 1,500. 【Chemical 1】 In formula (1), R １１ ~R １４ each independently represents an alkyl group or an aryl group which may have an alkyl group; R １５ represents a divalent hydrocarbon group. ２１ ~R ２４ each independently represents an alkyl group or an aryl group which may have an alkyl group; R ２５ represents a divalent hydrocarbon group. ３１ ~R ３４ each independently represents an alkyl group or an aryl group which may have an alkyl group; R ３５ represents a divalent hydrocarbon group. ４１ and R ４２ each independently represents an alkyl group or an aryl group which may have an alkyl group.

4. 3. The resin composition according to claim 1, wherein the partially fluorinated fluororesin (A) comprises a copolymer having units based on ethylene and units based on tetrafluoroethylene.

5. The mass percentage of the potassium titanate whiskers (D) relative to the total mass of the resin composition is r Ｄ When the above r Ｄ is 0.45 to 3.0, and the value obtained by dividing by the melt flow rate (g / 10 min) is Ｄ The resin composition according to claim 1 or 2, wherein the value obtained by multiplying the melt flow rate (g / 10 min) by the melt flow rate (g / 10 min) is 200 to 350.

6. A molded article obtained by molding the resin composition according to claim 1 or 2.

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