Highly rigid and transparent olefin resin molded body

Abstract

To provide a molding such as an olefinic resin sheet, a plate and a container which contains a biomass-derived polyethylene-based resin, has large mechanical strength, particularly, large rigidity (tensile elastic modulus), and is excellent in transparency, and has a thickness of a certain degree.SOLUTION: A high rigidity transparent olefinic resin molding is formed of an olefinic resin composition composed of a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, and has a tensile elastic modulus of 1,500-2,200 MPa and total light transmittance of 75-95%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an olefin-based resin molded article having high rigidity and excellent transparency, which is made of a polypropylene-based resin containing an environmentally friendly polyethylene resin derived from biomass. [Background technology]

[0002] Olefin resins such as polyethylene resin and polypropylene resin produced from fossil fuels are so-called general-purpose resins, and are widely used as materials for molded articles such as films, sheets, plates, containers, and molded articles.

[0003] However, in recent years, with the growing demand for the creation of a recycling-oriented society, research has been conducted into the use of biomass-derived olefin resins, which are carbon-neutral, renewable synthetic resins, instead of olefin resins such as polyethylene resins and polypropylene resins produced from fossil fuels, i.e., petroleum-derived olefin resins.

[0004] For example, a resin film for packaging products is provided which is made of a resin composition containing a biomass-derived polyolefin obtained by polymerizing a monomer containing ethylene derived from biomass, and a fossil fuel-derived polyolefin obtained by polymerizing ethylene derived from a fossil fuel and a monomer containing ethylene and / or α-olefin derived from a fossil fuel, the resin composition containing 5% by mass or more of the biomass-derived ethylene relative to the entire resin composition, and the resin composition has a molecular weight of 0.91 to 0.937 g / cm 3 "A resin film for packaging products having a density of 100 to 200 mm" (see, for example, Patent Document 1).

[0005] However, the above-mentioned resin films are intended for use in packaging products and are therefore thin and soft, and therefore have low mechanical strength, particularly rigidity (tensile modulus), and are therefore unsuitable for producing molded articles that require high mechanical strength.

[0006] Also, as a film having high rigidity (tensile modulus) and excellent transparency, "the film has at least one base layer and a skin layer laminated on one or both sides of the base layer, and the base layer has a melt flow rate of 1.5 g / 10 min or more and 15 g / 10 min or less at 190°C and a density of 0.910 g / cm3 per 100 parts by mass of polypropylene." 3 More than 0.935g / cm 3 a stretched polypropylene film having an image clarity of 65% or more and a haze value of 8% or less, the film being made of a polypropylene-based resin containing 1 to 23 parts by mass of polyethylene (containing plant-derived polyethylene) of 100 parts by mass or less of polypropylene, the skin layer being made of a polypropylene-based resin containing a copolymer having propylene as a monomer, the polypropylene-based resin containing a copolymer having propylene as a monomer being a mixture containing 10 parts by mass or less of polyethylene (containing plant-derived polyethylene) per 100 parts by mass of polypropylene, an ethylene-propylene random copolymer, and an ethylene-propylene-butene copolymer, and a mixture containing at least one of an ethylene-propylene-elastomer resin, an ethylene-butene-1-elastomer resin, a propylene-butene-1-elastomer resin, and an ethylene-propylene-butene-1-elastomer resin, the film having an image clarity of 65% or more and a haze value of 8% or less. (For example, see Patent Document 2.) has been proposed.

[0007] However, the above-mentioned stretched polypropylene film is a film that has been given rigidity by stretching, and an unstretched film still has low mechanical strength, particularly rigidity (tensile modulus), and is therefore unsuitable for producing molded articles having a certain thickness that requires mechanical strength. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5862055 [Patent Document 2] Patent No. 6764754 Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above problems, an object of the present invention is to provide a molded article having a certain thickness, such as an olefin-based resin sheet, plate, container, etc., which contains a biomass-derived polyethylene-based resin and has high mechanical strength, particularly rigidity (tensile elastic modulus), and excellent transparency. [Means for solving the problem]

[0010] That is, the present invention provides: [1] A highly rigid and transparent olefin-based resin molded product, which is made of an olefin-based resin composition comprising a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, and which has a tensile modulus of elasticity of 1500 to 2200 MPa and a total light transmittance of 75 to 95%. [2] The highly rigid and transparent olefin-based resin molded product according to the above [1], characterized in that the olefin-based resin composition comprises 100 parts by weight of a polypropylene-based resin and 3 to 40 parts by weight of a polyethylene-based resin. [3] The high-rigidity transparent olefin-based resin molded product according to the above [1] or [2], characterized in that the polypropylene-based resin is a homopolypropylene resin and / or a random polypropylene resin. [4] The highly rigid and transparent olefin-based resin molded product according to the above [1], [2] or [3], characterized in that the biomass-derived polyethylene-based resin is high-density polyethylene, low-density polyethylene and / or linear low-density polyethylene. [5] A highly rigid, transparent olefin-based resin molded product, characterized in that a surface layer is laminated on at least one surface of the highly rigid, transparent olefin-based resin layer according to any one of the above [1] to [4], the surface layer being made of an olefin-based resin composition comprising a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, the composition ratio of which is different from that of the highly rigid, transparent olefin-based resin layer; and [6] The highly rigid and transparent olefin-based resin molded article according to any one of the above [1] to [5], characterized in that the molded article is a sheet, plate, container or irregularly shaped article having a thickness of 0.1 mm or more. Regarding. Effect of the Invention

[0011] The highly rigid and transparent olefin-based resin molded article of the present invention has the above-mentioned structure, and contains a biomass-derived polyethylene resin, so that the amount of petroleum-derived polyethylene resin used can be reduced. In addition, it is possible to provide molded articles such as olefin-based resin sheets, plates, and containers that have high mechanical strength, especially high rigidity (tensile elastic modulus), and excellent transparency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The highly rigid and transparent olefin-based resin molded body of the present invention is made of an olefin-based resin composition consisting of a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, and is characterized by having a tensile modulus of elasticity of 1500 to 2200 MPa and a total light transmittance of 75 to 95%.

[0013] The petroleum-derived polypropylene resin is a polymer polymerized using propylene monomer refined from petroleum as the main raw material, and examples thereof include polypropylene homopolymers such as homopolypropylene resins and random polypropylene resins, and copolymers mainly composed of propylene and α-olefins such as ethylene, 1-butene, 1-hexene, 1-pentene, and 1-heptene, among which homopolypropylene resins and random polypropylene resins having excellent transparency are preferred. These polypropylene resins may be used alone, or two or more types of polypropylene resins may be used in combination.

[0014] Biomass-derived polyethylene resins are polymers made by polymerizing ethylene that has been chemically reacted and refined using ethanol produced from renewable natural raw materials (such as corn, sugarcane, beets, manioc, etc.).

[0015] Examples of the polyethylene resin derived from biomass include polyethylene homopolymers such as high density polyethylene resin, medium density polyethylene resin, and low density polyethylene resin, and copolymers mainly composed of ethylene and α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-pentene, and 1-heptene, among which high density polyethylene resin, low density polyethylene, and linear low density polyethylene are preferred. These polyethylene resins may be used alone or in combination of two or more kinds.

[0016] The high-rigidity, transparent olefin-based resin molded body of the present invention is made of the above-mentioned olefin-based resin composition, which is made of a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin. Since the molded body has a tensile modulus of elasticity of 1500 to 2200 MPa and a total light transmittance of 75 to 95%, it is preferable that the composition be made of 100 parts by weight of polypropylene-based resin and 3 to 40 parts by weight of polyethylene-based resin.

[0017] Furthermore, if the amount of biomass-derived polyethylene resin added is large, the molded article will lose stiffness and its transparency, printability, etc. will decrease, so for molded articles that require these properties, it is preferable to add a small amount.

[0018] Furthermore, to the polyolefin resin composition, additives which have been generally used in the past when molding polyolefin resins, for example, inorganic fillers such as calcium carbonate, magnesium carbonate, aluminum oxide, magnesium oxide, titanium oxide, magnesium hydroxide, talc, mica, clay, etc., heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, antifogging agents, antistatic agents, flame retardants, colorants, pigments, etc., may be added as necessary, within the ranges of the above physical properties.

[0019] The shape of the highly rigid, transparent olefin-based resin molded body of the present invention is not particularly limited as long as it has a certain degree of thickness, and examples of such shapes include sheets, plates, containers, tabular bodies, pillars, and other irregularly shaped bodies having a thickness of 0.1 mm or more.

[0020] The method for producing the high-rigidity, transparent olefin-based resin molded product of the present invention is not particularly limited, and any conventionally known method may be adopted, and the above-mentioned olefin-based resin composition is molded by a conventionally known molding method such as an extrusion method, a T-die method, a casting method, a calendar method, an injection molding method, or a press method.

[0021] Furthermore, a surface layer may be laminated on at least one surface of the high-rigidity, transparent olefin-based resin molded body of the present invention, the surface layer being made of an olefin-based resin composition consisting of a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, the composition ratio of which differs from the composition ratio of the high-rigidity, transparent olefin-based resin molded body.

[0022] The surface layer is made of an olefin resin composition comprising the above-mentioned petroleum-derived polypropylene resin and biomass-derived polyethylene resin, but the composition ratio thereof is different from the composition ratio of the high-rigidity, transparent olefin resin molded article.

[0023] As the ratio of biomass-derived polyethylene resin in the olefin-based resin composition of the surface layer increases, the ratio of biomass-derived polyethylene resin in the entire molded body increases, the biomass content increases, and the amount of fossil fuel used can be further reduced, thereby contributing to the creation of a society that is kind to the environment and circular economy.

[0024] In addition, the high-rigidity, transparent olefin-based resin molded body of the present invention has poor cold resistance due to its high polypropylene-based resin content, but the cold resistance is improved by laminating a surface layer containing a high ratio of biomass-derived polyethylene-based resin in the olefin-based resin composition.

[0025] Furthermore, polyethylene-based resins have poor printability and are less scratch-resistant and more susceptible to damage than polypropylene-based resins, so when performance such as scratch resistance and printability is required, a higher proportion of polypropylene-based resin is preferred.

[0026] Therefore, both the high-rigidity transparent olefin-based resin molded body and the surface layer laminated on at least one surface thereof are made of an olefin-based resin composition consisting of the aforementioned petroleum-derived polypropylene-based resin and biomass-derived polyethylene-based resin, but the composition ratios are different and are appropriately determined depending on the required performance of the surface layer.

[0027] Furthermore, the thickness ratio between the highly rigid transparent olefin-based resin molded product and the surface layer laminated on at least one surface of the product may be appropriately determined, and is generally 1:1 to 100:1. EXAMPLES

[0028] Next, the present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples.

[0029] The olefin resins used are as follows: (1) Petroleum-derived polypropylene resin h-PP homopolypropylene resin (Prime Polymer Co., Ltd., product name "Prime Polyp B), MFR at 230℃ 1.0g / 10min, melting point approx. 160℃) r-PP Random polypropylene resin (Prime Polymer Co., Ltd., product name "PrimePo Repro, MFR 2.4g / 10min at 230℃, melting point approx. 150℃)

[0030] (2) Biomass-derived polyethylene resin Bio-HDPE High density polyethylene resin (manufactured by Braskem, product name "SHE15 0", MFR at 190℃ 0.6g / 10min, melting point approx. 140℃, biomass content 94%) Bio-LLDPE Linear low-density polyethylene resin (manufactured by Braskem, product name "SLH118", MFR at 190℃ 1.0g / 10min, melting point approx. 130℃, biomass content 84%) Bio-LDPE low-density polyethylene resin (manufactured by Braskem, product name "STN700 6", MFR at 190℃ 0.6g / 10min, melting point approx. 120℃, biomass content 95%)

[0031] (Examples 1 to 5, Comparative Examples 1 to 5) The olefin resin compositions consisting of the predetermined amounts of h-PP, r-PP, Bio-HDPE, Bio-LLDPE, Bio-LDPE and 1.0 part by weight of an antistatic agent (manufactured by Kao Corporation, product name "ELESTMASTER") shown in Tables 1 and 2 were fed to a single screw extruder with a screw diameter of 70 mm, melt-kneaded at 210°C, extruded at a speed of about 6.0 m through a T-die, and cooled with a mirror roll and an air knife set at 30°C to obtain a sheet-like molded product.

[0032] (Examples 6 to 8) The olefin resin composition for the central layer, which is composed of the predetermined amounts of h-PP, r-PP, Bio-HDPE, Bio-LLDPE, and Bio-LDPE shown in Table 3, and 1.0 part by weight of an antistatic agent (manufactured by Kao Corporation, product name "ELESTMASTER"), and the olefin resin composition for the surface layer, which is composed of 1.0 part by weight of h-PP, r-PP, Bio-HDPE, and an antistatic agent (manufactured by Kao Corporation, product name "ELESTMASTER"), were fed to a single-screw extruder for the central layer with a screw diameter of 70 mm and a single-screw extruder for the surface layer with a screw diameter of 70 mm, respectively, and melt-kneaded at 230°C. After that, the three-layer co-extrusion was performed at a speed of about 6.0 m using a feed block, and the three-layer sheet-like molded product was obtained by cooling with a mirror roll and an air knife set at 30°C.

[0033] The obtained molded article was subjected to a tensile test in accordance with JIS K 7127:1999 to measure the tensile strength (MD and TD), tensile modulus (MD and TD), and elongation (MD and TD).

[0034] In addition, the haze was measured in accordance with JIS K 7136: 2000, and the total light transmittance was measured in accordance with JIS K 7361: 1997. The results are shown in Tables 1 to 3.

[0035] [Table 1]

[0036] [Table 2]

[0037] [Table 3] [Industrial Applicability]

[0038] The highly rigid and transparent olefin-based resin molded article of the present invention is as described above, has high mechanical strength, particularly high rigidity (tensile elastic modulus), and excellent transparency, and is suitably used as containers, industrial materials, building materials, etc., in the form of molded articles such as olefin-based resin sheets, plates, and containers.

Claims

1. A highly rigid and transparent olefin-based resin molded article is made of an olefin-based resin composition consisting of 100 parts by weight of a petroleum-derived polypropylene-based resin and 3 to 40 parts by weight of a biomass-derived polyethylene-based resin, and is characterized in that the molded article has a tensile modulus of elasticity of 1500 to 2200 MPa, a total light transmittance of 85 to 90%, and a haze value of 30 to 60%.

2. 2. The highly rigid and transparent olefin resin molded article according to claim 1, wherein the polypropylene resin is a homopolypropylene resin and / or a random polypropylene resin.

3. 3. The highly rigid and transparent olefin-based resin molded article according to claim 1, wherein the biomass-derived polyethylene-based resin is a high-density polyethylene, a low-density polyethylene and / or a linear low-density polyethylene.

4. A highly rigid, transparent olefin-based resin molded product, characterized in that a surface layer is laminated on at least one surface of the highly rigid, transparent olefin-based resin molded product according to any one of claims 1 to 3, and the surface layer is made of an olefin-based resin composition consisting of a petroleum-derived polypropylene-based resin and a biomass-derived polyethylene-based resin, the composition ratio of which is different from the composition ratio of the highly rigid, transparent olefin-based resin molded product.

5. 5. The highly rigid and transparent olefin-based resin molded article according to claim 1, which is a sheet, plate, container or irregularly shaped article having a thickness of 0.1 mm or more.

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