Thermoplastic resin composition

Abstract

To provide a thermoplastic resin composition which is excellent in mechanical strength.SOLUTION: A thermoplastic resin composition (X) contains the following polyolefin resin (A) and the following polyolefin (D), wherein a weight ratio [(A) / (D)] of the polyolefin resin (A) to the polyolefin resin (D) is 0.01 / 99.99 to 0.9 / 99.1. Polyolefin resin (A): containing α-olefin (3-8 carbon atoms) as a constituent monomer, and having isotacticity of an α-olefin part of 1-69%; and polyolefin resin (D): containing α-olefin (3-8 carbon atoms) as a constituent monomer, and isotacticity of the α-olefin part of 70-100%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition. [Background technology]

[0002] Thermoplastic resin compositions, particularly polyolefin resins, are inexpensive and have excellent moldability, rigidity, electrical insulation, etc., and are therefore widely and generally used as films, fibers, and other molded articles of various shapes. Various modifiers for polyolefin resins have also been developed, and modifiers containing low-molecular-weight polyolefins have been proposed for the purpose of improving pigment dispersibility and mechanical strength (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-117362 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] However, even the above techniques have not been fully satisfactory in terms of mechanical strength. An object of the present invention is to provide a thermoplastic resin composition having excellent mechanical strength. [Means for solving the problem]

[0005] The present inventors have conducted extensive research to achieve the above object and have arrived at the present invention. Specifically, the present invention relates to a thermoplastic resin composition (X) comprising the following polyolefin resin (A) and the following polyolefin resin (D), in which the weight ratio of the polyolefin resin (A) to the polyolefin resin (D) [(A) / (D)] is 0.01 / 99.99 to 0.9 / 99.1. Polyolefin resin (A): Contains α-olefin (having 3 to 8 carbon atoms) as a constituent monomer, and the isotacticity of the α-olefin portion is 1 to 69%; Polyolefin resin (D): Contains α-olefin (having 3 to 8 carbon atoms) as a constituent monomer, and the isotacticity of the α-olefin portion is 70 to 100%; [Effects of the Invention]

[0006] The thermoplastic resin composition (X) of the present invention has the following effects. (1) It gives molded products excellent mechanical strength (tensile strength and impact strength). (2) Even if the polyolefin resin (D) is a recycled polyolefin resin (DR), it has excellent mechanical strength. DETAILED DESCRIPTION OF THE INVENTION

[0007] <Polyolefin resin (A)> The polyolefin resin (A) in the present invention contains an α-olefin (having 3 to 8 carbon atoms) as a constituent monomer, and the isotacticity of the α-olefin portion is 1 to 69%.

[0008] In the following, "α-olefin (having 3 to 8 carbon atoms)" may be referred to as "α-olefin". Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Among the above α-olefins, propylene is preferred from the viewpoint of isotacticity, which will be described later.

[0009] The polyolefin resin (A) may contain other monomers as constituent monomers in addition to the α-olefin. In this case, the weight of the other monomers is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 2% by weight or less, based on the weight of all the monomers constituting the polyolefin resin (A).

[0010] Examples of other monomers constituting the polyolefin resin (A) include ethylene, 2-butene, isobutene, α-olefins having 9 to 30 carbon atoms (hereinafter sometimes abbreviated as C) (1-decene, 1-dodecene, etc.), and unsaturated monomers having 4 to 30 carbon atoms other than α-olefins (for example, vinyl acetate). Of the above other monomers, ethylene is preferred, and among (A), propylene / ethylene copolymers and propylene polymers are preferred, with propylene polymers being more preferred.

[0011] The isotacticity of the α-olefin portion of the polyolefin resin (A) is preferably from 1 to 69%, more preferably from 10 to 65%, and particularly preferably from 30 to 60%, from the viewpoint of mechanical strength.

[0012] The isotacticity in the present invention is 13 It can be calculated using C-NMR (nuclear magnetic resonance spectroscopy). Generally, when the α-olefin is propylene, the side chain methyl group, and when the α-olefin is 1-butene, 1-pentene, 1-hexene, 1-heptene, or 1-octene, the side chain methylene group adjacent to the main chain methine group are affected by the configuration (meso or racemo) of both adjacent ones (triad), both adjacent ones (pentad), and even both adjacent ones (heptad) of the pentad, and are known to have peaks observed at different chemical shifts. Therefore, the evaluation of stereoregularity is generally performed on the pentad, and the isotacticity in the present invention is also calculated based on the evaluation of the pentad.

[0013] That is, when the α-olefin is propylene, 13 Regarding the carbon peaks derived from the side chain methyl groups in propylene obtained by C-NMR, when the α-olefin is 1-butene, 1-pentene, 1-hexene, 1-heptene, or 1-octene, 13Regarding the carbon peaks derived from the side chain methylene groups adjacent to the main chain methine groups in the α-olefins obtained by C-NMR, the peak intensity of each pentad in the α-olefin portion of polyolefin (A) is (H). In isotactic polyolefins in which the pentad is formed only from a mesostructure, if the α-olefin is propylene, it is a methyl group. In the case of α-olefins of 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, it is a methyl group. 13 When the peak intensity derived from a side-chain methylene group adjacent to a main-chain methine group in an α-olefin obtained by C-NMR is taken as (Ha), isotacticity can be calculated using the following formula: Isotacticity (%) = [(Ha) / Σ(H)] × 100 (1)

[0014] The conditions for measuring isotacticity in the present invention are as follows. Equipment: JEOL Ltd. ECZ400R Measurement mode: Proton decoupling method Pulse width: 8μsec Pulse repetition time: 4.6 seconds Relaxation time: 3.0 seconds Accumulation count: 10,000 times Solvent: orthodichlorobenzene Reference material: tetramethylsilane Sample concentration: 10mg / mL ·Measurement temperature: 120℃

[0015] The number average molecular weight (Mn) of the polyolefin resin (A) is preferably from 1,000 to 100,000, more preferably from 10,000 to 80,000, and particularly preferably from 20,000 to 60,000, from the viewpoint of mechanical strength.

[0016] In the present invention, the number average molecular weight (Mn) and weight average molecular weight (Mw) can be measured by GPC (gel permeation chromatography). In the present invention, the conditions for measuring Mn by GPC are as follows. Apparatus: High-temperature gel permeation chromatography ["AllianceGPCV2000", manufactured by Waters] Detection device: Refractive index detector Solvent: orthodichlorobenzene Reference material: Polystyrene Sample concentration: 3mg / ml Column stationary phase: PLgel 10 μm, MIXED-B 2 columns in series [Manufactured by Polymer Laboratories, Inc.] Column temperature: 135℃ Reference material: Standard polystyrene

[0017] The polyolefin resin (A) can be produced by a known method, but may also be a commercially available product, such as those under the trade names "ELMODU S400," "ELMODU S410," "ELMODU S600," and "ELMODU S901," all manufactured by Idemitsu Kosan Co., Ltd.

[0018] <Polyolefin resin (D)> The polyolefin resin (D) in the present invention contains an α-olefin (having 3 to 8 carbon atoms) as a constituent monomer, and the isotacticity of the α-olefin portion is 70 to 100%.

[0019] Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Of the above α-olefins, propylene is preferred from the viewpoint of mechanical strength.

[0020] The polyolefin resin (D) may contain other monomers as constituent monomers in addition to the α-olefin. In this case, the weight of the other monomers is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 2% by weight or less, based on the weight of all the monomers constituting the polyolefin resin (D).

[0021] Examples of other monomers constituting the polyolefin resin (D) include ethylene, 2-butene, isobutene, α-olefins having 9 to 30 carbon atoms (hereinafter sometimes abbreviated as C) (1-decene, 1-dodecene, etc.), and unsaturated monomers having 4 to 30 carbon atoms other than α-olefins (for example, vinyl acetate). Of the other monomers, ethylene is preferred, and among (D), propylene / ethylene copolymers and propylene polymers are preferred, with propylene polymers being more preferred.

[0022] The isotacticity of the α-olefin portion of the polyolefin resin (D) is preferably from 70 to 100%, more preferably from 75 to 100%, and particularly preferably from 80 to 100%, from the viewpoint of mechanical strength.

[0023] The number average molecular weight (Mn) of the polyolefin resin (D) is preferably 20,000 to 400,000, more preferably 40,000 to 300,000, from the viewpoint of mechanical strength.

[0024] Furthermore, recycled polyolefin resin (DR) is also suitable as polyolefin resin (D). The (DR) is preferably a polyolefin resin that has been subjected to molding once and then crushed, pulverized, pelletized, or the like.

[0025] <Thermoplastic resin composition (X)> The thermoplastic resin composition (X) of the present invention contains the polyolefin resin (A) and the polyolefin resin (D), and the weight ratio of the polyolefin resin (A) to the polyolefin resin (D) [(A) / (D)] is 0.01 / 99.99 to 0.9 / 99.1. If the weight ratio [(A) / (D)] is less than 0.01 / 99.99, the Izod impact strength of the molded article will be poor, and if it exceeds 0.9 / 99.1, the mechanical strength of the molded article will be poor. The weight ratio [(A) / (D)] is preferably 0.05 / 99.95 to 0.8 / 99.2, and more preferably 0.1 / 99.1 to 0.5 / 99.5.

[0026] The thermoplastic resin composition (X) of the present invention may further contain, if necessary, one or more additives (N) selected from the group consisting of fillers (N1), colorants (N2), matting agents (N3), antistatic agents (N4), dispersants (N5), flame retardants (N6), foaming agents (N7), antioxidants (N8), ultraviolet absorbers (N9) and plasticizers (N10), within the scope of not impairing the effects of the present invention.

[0027] Examples of the filler (N1) include organic fillers (for example, wood flour, cellulose) and inorganic fillers (for example, calcium carbonate, talc, glass fiber, carbon fiber). Among these fillers (N1), from the viewpoint of mechanical strength, inorganic fillers are preferred, and calcium carbonate is more preferred. The amount of (N1) used based on the total weight of the thermoplastic resin composition (X) is, for example, 70 wt % or less, preferably 3 to 70 wt %, and more preferably 5 to 40 wt %.

[0028] The total amount of (N2) to (N10) used in the thermoplastic resin composition (X) of the present invention is, for example, 30% by weight or less, based on the total weight of the thermoplastic resin composition (X), and preferably 1 to 20% by weight from the viewpoint of functional expression of (N) and industrial applications.

[0029] The amount of each additive (N) other than (N1) used, based on the total weight of the thermoplastic resin composition (X), is as follows: (N2) is, for example, 10% by weight or less, preferably 1 to 5% by weight; (N3) is, for example, 20% by weight or less, preferably 1 to 10% by weight; (N4) is, for example, 10% by weight or less, preferably 1 to 5% by weight; (N5) is, for example, 20% by weight or less, preferably 0 to 15% by weight, and more preferably 0 to 10% by weight; (N6) is, for example, 15% by weight or less, preferably 3 to 10% by weight; (N7) is, for example, 1 to 20% by weight or less, preferably 5 to 15% by weight; (N8) is, for example, 3% by weight or less, preferably 0.01 to 1% by weight; (N9) is, for example, 3% by weight or less, preferably 0.01 to 1% by weight; and (N10) is, for example, 20% by weight or less, preferably 5 to 15% by weight.

[0030] In addition, when the same additives are used among (N1) to (N10), the amount of each additive that exerts the corresponding additive effect is not used regardless of the effect of the other additives, but the amount used is adjusted according to the purpose of use, taking into consideration that the effects of the other additives can also be obtained at the same time.

[0031] The method for producing the thermoplastic resin composition (X) of the present invention includes the following steps: (1) A method in which the entire amounts of the polyolefin resin (D) and the polyolefin resin (A), and optionally (N), are mixed together in one lump to prepare a resin composition (lump method); (2) A method (masterbatch method) in which a part of the polyolefin resin (D), the whole of the polyolefin resin (A), and, if necessary, a part or all of the additive (N) are mixed to prepare a masterbatch resin composition containing a high concentration of polyolefin resin (A), and then the remaining polyolefin resin (D) and, if necessary, the remaining additive (N) are added and mixed to prepare a resin composition is also exemplified. From the viewpoint of the mixing efficiency of the polyolefin resin (A), the method (2) is preferred.

[0032] <Molded products> The molded article of the present invention is a molded product of the above thermoplastic resin composition (X), that is, the molded article of the present invention is obtained by molding the above thermoplastic resin composition (X). Examples of molding methods include injection molding, compression molding, calendar molding, slush molding, rotational molding, extrusion molding, blow molding, and film molding (casting, tenter molding, inflation method, etc.), and molding can be performed by any method incorporating means such as single-layer molding, multi-layer molding, or foam molding depending on the purpose. Examples of the form of the molded product include plate, sheet, film, fiber (including nonwoven fabric, etc.), etc. [Example]

[0033] Examples of the present invention will be described below, but the present invention is not limited to these. In the following, parts are by weight. In the following, Examples 1 to 3 and 11 to 13 correspond to Reference Examples 1 to 6, respectively.

[0034] <Examples 1 to 3, Comparative Examples 1 and 2> According to the compounding composition (parts) in Table 1, polyolefin resin (A) and polyolefin resin (D) were melt-kneaded in a twin-screw extruder (trade name "KZW45TW", manufactured by Technovel Co., Ltd.) at 230°C and 100 rpm to obtain each thermoplastic resin composition (X). Each thermoplastic resin composition (X) was injection molded using an injection molding machine (trade name "PS40E5ASE", manufactured by Nissei Plastics Co., Ltd.) at a nozzle temperature of 230°C and a mold temperature of 50°C, and evaluated according to the evaluation methods described below. The results are shown in Table 1.

[0035] <Evaluation method> (1) Tensile strength The tensile strength was evaluated by measuring in accordance with JIS K7171. <Evaluation criteria> ◎:30MPa or more ○: 25MPa or more and less than 30MPa △: 20MPa or more and less than 25MPa ×: Less than 20 MPa

[0036] (2) Impact resistance The Izod impact value was measured in accordance with JIS K7110. <Evaluation criteria> ◎: 3.0 kJ / m 2 End ○: 1.5kJ / m 2 More than 3.0kJ / m 2 less than △: 1.0 kJ / m 2 More than 1.5kJ / m 2 less than ×:1.0kJ / m 2 less than

[0037] [Table 1]

[0038] <Examples 11 to 13, Comparative Examples 11 and 12> According to the compounding composition (parts) in Table 2, polyolefin resin (A) and recycled polyolefin resin (DR) were melt-kneaded in a twin-screw extruder (trade name "KZW45TW", manufactured by Technovel Co., Ltd.) at 230°C and 100 rpm to obtain each thermoplastic resin composition (X). After pelletizing, the mixture was injection molded using an injection molding machine (trade name "PS40E5ASE", manufactured by Nissei Plastics Co., Ltd.) at a nozzle temperature of 230°C and a mold temperature of 50°C to prepare test specimens, which were evaluated according to the evaluation methods described below. The results are shown in Table 2.

[0039] (1) Tensile strength The tensile strength was evaluated by measuring in accordance with JIS K7171. <Evaluation criteria> ◎:25MPa or more ○: 20MPa or more and less than 25MPa △: 15 MPa or more and less than 20 MPa ×: Less than 15 MPa

[0040] (2) Impact resistance The Izod impact value was measured in accordance with JIS K7110. <Evaluation criteria> ◎: 2.5kJ / m 2 End ○: 1.2 kJ / m 2More than 2.5kJ / m 2 less than △: 0.8kJ / m 2 More than 1.2kJ / m 2 less than ×:0.8kJ / m 2 less than

[0041] [Table 2]

[0042] <Examples 21 to 23, Comparative Examples 21 to 22> According to the compounding composition (parts) in Table 3, polyolefin resin (A), polyolefin resin (D), and filler (N1) were melt-kneaded in a twin-screw extruder (trade name "KZW45TW", manufactured by Technovel Co., Ltd.) at 230°C and 100 rpm to obtain each thermoplastic resin composition (X). After pelletizing, the mixture was injection molded using an injection molding machine (trade name "PS40E5ASE", manufactured by Nissei Plastics Co., Ltd.) at a nozzle temperature of 230°C and a mold temperature of 50°C to prepare test specimens, which were evaluated according to the evaluation methods described below. The results are shown in Table 3.

[0043] (1) Tensile strength The tensile strength was evaluated by measuring in accordance with JIS K7171. <Evaluation criteria> ◎:25MPa or more ○: 20MPa or more and less than 25MPa △: 15 MPa or more and less than 20 MPa ×: Less than 15 MPa

[0044] (2) Impact resistance The Izod impact value was measured in accordance with JIS K7110. <Evaluation criteria> ◎: 2.5kJ / m 2 End ○: 1.2 kJ / m 2 More than 2.5kJ / m 2 less than △: 0.8kJ / m 2 More than 1.2kJ / m 2 less than ×:0.8kJ / m 2 less than

[0045] [Table 3]

[0046] The results in Tables 1 to 3 show that the thermoplastic resin composition (X) of the present invention provides molded articles with superior mechanical strength compared to the comparative examples. Furthermore, even when the polyolefin resin (D) is a recycled polyolefin resin (DR), the molded articles still have superior mechanical strength. [Industrial Applicability]

[0047] Each thermoplastic resin composition (X) of the present invention imparts excellent mechanical strength to molded articles, and is therefore suitable for use as a material for housing products (for home appliances, office equipment, game machines, office machines, etc.) molded by various molding methods (such as injection molding, compression molding, calendar molding, slush molding, rotational molding, extrusion molding, blow molding, foam molding, and film molding (casting, tenter molding, and inflation molding)), plastic container materials (such as trays (e.g., IC trays) and other containers used in clean rooms), various cushioning materials, covering materials (such as packaging films and protective films), flooring sheets, artificial turf, mats, tape substrates (for semiconductor manufacturing processes, etc.), and various molded articles (such as automobile parts).

Claims

1. A thermoplastic resin composition (X) comprising the following polyolefin resin (A), the following polyolefin resin (D), and a filler (N1), wherein the filler (N1) is calcium carbonate, the number average molecular weight (Mn) of the polyolefin resin (D) is 20,000 to 400,000, the weight ratio of the polyolefin resin (A) to the polyolefin resin (D) [(A) / (D)] is 0.01 / 99.99 to 0.9 / 99.1, and the weight of the filler (N1) is 5 to 40% by weight based on the weight of the thermoplastic resin composition (X). Polyolefin resin (A): a propylene / ethylene copolymer or propylene polymer containing an α-olefin (having 3 carbon atoms) as a constituent monomer, the α-olefin portion having an isotacticity of 30 to 65%; Polyolefin resin (D): a propylene / ethylene copolymer or propylene polymer containing an α-olefin (having 3 carbon atoms) as a constituent monomer, in which the isotacticity of the α-olefin portion is 70 to 100%;

2. The thermoplastic resin composition (X) according to claim 1, wherein the polyolefin resin (A) has a number average molecular weight (Mn) of 1,000 to 100,000.

3. A molded article obtained by molding the thermoplastic resin composition (X) according to claim 1 or 2.

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