Flexible tube

Abstract

The present invention aims to provide a flexible tube that is excellent in both flexibility and transparency, and a tube, hose, pipe, or cable covering material equipped with the flexible tube. [Solution] A flexible tube having a layer comprising a resin composition (X) containing 60 to 95 parts by mass of polymer (A) satisfying the following requirement (AI), and 5 to 40 parts by mass of polymer (B) satisfying the following requirement (BI). (AI): Contains 50.0 to 100 mol% of structural units derived from 4-methyl-1-pentene and 0 to 50.0 mol% of structural units derived from α-olefins having 5 to 20 carbon atoms (excluding 4-methyl-1-pentene). (BI): Contains 50.0 to 95.0 mol% of structural units derived from 4-methyl-1-pentene and 5.0 to 50.0 mol% of structural units derived from α-olefins having 2 to 4 carbon atoms.

Description

Technical Field

[0001] The present invention relates to a flexible tube. The present invention also relates to a tube, hose or pipe provided with the flexible tube, or a cable coating material.

Background Art

[0002] 4-Methyl-1-pentene polymers such as 4-methyl-1-pentene homopolymers or 4-methyl-1-pentene copolymers are resins having excellent characteristics such as transparency, heat resistance, light weight, steam resistance, mold release properties, gas permeability, and electrical properties compared to polyethylene and polypropylene. They are used in various fields such as food containers, auxiliary materials for electronic and information members, laboratory equipment, stationery, engineering materials for crosslinking, mold release films, films for electronic and information members, food packaging materials, and synthetic paper. As an example of a molded body using such a 4-methyl-1-pentene polymer, a molded body as described in Patent Document 1 can be cited.

[0003] On the other hand, fluororesins are also widely used as resins for molding applications. For example, Patent Document 2 discloses a tube containing a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer as a fluororesin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] While 4-methyl-1-pentene polymers, such as those described in Patent Document 1, are resins with excellent transparency, there was room for improvement in terms of flexibility when applying these resins to flexible tubes such as tubing. On the other hand, fluorine-based resins, such as those described in Patent Document 2, are widely used in flexible tubes and other flexible pipes due to their excellent flexibility, but they have drawbacks in terms of transparency. The present invention aims to provide a flexible tube that is excellent in both flexibility and transparency, and a tube, hose, pipe, or cable covering material equipped with the flexible tube. [Means for solving the problem]

[0006] The present invention relates, for example, to the following [1] to [6]. [1] 60 to 95 parts by mass of polymer (A) that meets the following requirements (AI), and A flexible tube having a layer containing a resin composition (X) comprising 5 to 40 parts by mass of polymer (B) that satisfies the following requirement (BI) (wherein the total of polymer (A) and polymer (B) is 100 parts by mass). (AI): Polymer (A) contains 50.0 to 100 mol% of structural units derived from 4-methyl-1-pentene and 0 to 50.0 mol% of structural units derived from α-olefins having 5 to 20 carbon atoms (excluding 4-methyl-1-pentene). (BI): Polymer (B) contains 50.0 to 95.0 mol% of structural units derived from 4-methyl-1-pentene and 5.0 to 50.0 mol% of structural units derived from α-olefins having 2 to 4 carbon atoms.

[0007] [2] The flexible tube according to [1], wherein the total content of polymer (A) and polymer (B) in the resin composition (X) is 70 to 100% by mass. [3] The flexible tube according to [1] or [2], wherein the tensile elongation at break of the polymer (B), measured in accordance with JIS K 7127, is 150 to 1000%.

[0008] [4] The flexible tube according to any one of [1] to [3], wherein the polymer (B) has a glass transition temperature (Tg) of 10 to 100°C as measured by a differential scanning calorimeter (DSC). [5] The flexible tube according to any one of [1] to [4], wherein the content of the fluorine compound in the resin composition (X) is 0 to 10% by mass. A tube, hose, pipe, or cable covering material comprising a flexible pipe as described in any of [6], [1], to [5]. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a flexible tube that is excellent in both flexibility and transparency, and a tube, hose, pipe, or cable covering material equipped with the flexible tube. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below. In this specification, numerical ranges indicated using "~" include the values ​​indicated before and after them as the lower and upper limits, respectively. The various monomers in this invention may be derived from fossil raw materials, from biological sources such as biomass, from chemical recycling, or from mixtures thereof.

[0011] The flexible tube according to the present invention has a layer comprising a polymer (A) and a resin composition (X) containing polymer (B). [conversely (A)] The flexible tube according to the present invention has good transparency due to the inclusion of polymer (A). Polymer (A) satisfies the following requirement (AI). In the following description, the constituent unit derived from 4-methyl-1-pentene may be referred to as "constituent unit (ai)". Similarly, the constituent unit derived from α-olefins having 5 to 20 carbon atoms (excluding 4-methyl-1-pentene) may be referred to as "constituent unit (a-ii)".

[0012] <Requirements (AI)> The polymer (A) contains 50.0 to 100 mol% of a structural unit derived from 4-methyl-1-pentene and 0 to 50.0 mol% of a structural unit derived from an α-olefin having 5 to 20 carbon atoms (excluding 4-methyl-1-pentene).

[0013] The content (UA1) of the structural unit (a-i) in the polymer (A) is preferably 88.0 to 100 mol%, more preferably 93.0 to 99.0 mol%, and still more preferably 95.0 to 98.0 mol% (provided that the total of the content of the structural unit (i) and the content of the structural unit (ii) is 100 mol%).

[0014] The content (UA2) of the structural unit (a-ii) in the polymer (A) is preferably 0 to 12.0 mol%, more preferably 1 to 7 mol%, and still more preferably 2.0 to 5.0 mol% (provided that the total of the content of the structural unit (i) and the content of the structural unit (ii) is 100 mol%).

[0015] UA1 and UA2 are determined by the method described in the examples. The polymer (A) in which UA1 and UA2 are within the above ranges is excellent in transparency, mold release property, heat resistance, etc. Therefore, a flexible tube containing the polymer (A) in which UA1 and UA2 are within the above ranges also tends to have excellent physical properties.

[0016] The α-olefin that leads to the structural unit (a-ii) is, for example, a linear α-olefin. Examples of the α-olefin that leads to the structural unit (a-ii) include 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, and 1-eicosene.

[0017] Among these, linear α-olefins having 6 to 18 carbon atoms are preferred. Specific examples of the α-olefin that leads to the structural unit (a-ii) include 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-heptadecene, and 1-octadecene, with 1-decene, 1-hexadecene, and 1-octadecene being particularly preferred.

[0018] The structural unit (a-ii) may be derived from only one kind selected from the group consisting of α-olefins having 5 to 20 carbon atoms, or may be derived from two or more kinds selected from the group consisting of α-olefins having 5 to 20 carbon atoms.

[0019] A preferred embodiment of the polymer (A) includes a copolymer consisting only of the structural unit (a-i) and the structural unit (a-ii). In this case, the total content of the structural unit (a-i) and the structural unit (a-ii) is 100 mol%.

[0020] Another preferred embodiment of the polymer (A) includes, in addition to the structural unit (a-i) and the structural unit (a-ii), a structural unit derived from 4-methyl-1-pentene and other polymerizable monomers other than α-olefins having 5 to 20 carbon atoms, in a small amount that does not impair the object of the present invention, specifically 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less. The other polymerizable monomer may be one kind or two or more kinds.

[0021] Other preferred examples of polymerizable monomers include vinyl compounds having a cyclic structure such as styrene, vinylcyclopentane, vinylcyclohexane, and vinylnorbornane; vinyl esters such as vinyl acetate; unsaturated organic acids or their derivatives such as maleic anhydride; conjugated dienes such as butadiene, isoprene, pentadiene, and 2,3-dimethylbutadiene; 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene. Examples of non-conjugated polyenes include ene, dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, and 2-propenyl-2,2-norbornadiene.

[0022] Here, if polymer (A) contains structural units derived from other polymerizable monomers, it is preferable that the total content of structural units (a-ii) and structural units derived from other polymerizable monomers satisfies the range of content of structural units (a-ii). In this case, the total content of structural units (ai), structural units (a-ii), and structural units derived from other polymerizable monomers is 100 mol%.

[0023] <Intrinsic viscosity of polymer (A) in decalin at 135°C> The intrinsic viscosity [η] of polymer (A), measured in decalin at 135°C by the method described in the examples below, is preferably 0.5 to 5.0 dl / g, and more preferably 1.0 to 3.0 dl / g. When the intrinsic viscosity [η] of polymer (A) falls within the aforementioned range, the fluidity when forming it into a flexible tube is good. The intrinsic viscosity [η] can be adjusted, for example, by the amount of hydrogen added during the polymerization process when producing polymer (A).

[0024] <Molecular weight and molecular weight distribution of polymer (A)> The weight-average molecular weight (Mw) of polymer (A) measured by the method described in the examples below is preferably 10,000 to 1,000,000, more preferably 20,000 to 800,000, in terms of polystyrene. Furthermore, the molecular weight distribution (Mw / Mn) obtained by dividing Mw by the number-average molecular weight Mn of polymer (A) is preferably 0.5 to 10.0, more preferably 1.0 to 5.0.

[0025] When the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of polymer (A) are within the above range, it exhibits excellent moldability and is preferable from the viewpoint of appearance and surface roughness. It is also preferable because the influence of low molecular weight polymers and low stereoregularity polymers derived from the composition distribution is reduced, and the mechanical strength of the resulting molded article does not decrease easily. The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of polymer (A) can be adjusted, for example, by the amount of hydrogen added during the polymerization process when producing polymer (A).

[0026] <MFR of polymer (A)> The melt flow rate (MFR) of polymer (A) measured in accordance with ASTM D1238 at 260°C and a 5kg load is preferably in the range of 1 to 100 g / 10 min, more preferably 5 to 50 g / 10 min, and even more preferably 7 to 30 g / 10 min. An MFR within this range is preferable in terms of fluidity when molding the resin composition (X) into a flexible tube.

[0027] <Density of polymer (A)> The density of polymer (A) measured by the method described in the examples below is preferably 700 to 1,000 kg / m³. 3 More comfortably 800-900 kg / m 3 Therefore, if the density of polymer (A) is within the above range, the amount of resin used when manufacturing a molded product (such as a flexible tube) of the same volume can be reduced, which is preferable from the viewpoint of reducing environmental impact. The density of polymer (A) can be adjusted, for example, by the amount of hydrogen added in the polymerization process when manufacturing polymer (A).

[0028] <Melting point of polymer (A)> The melting point (Tm) of polymer (A), as measured by differential scanning calorimeter (DSC) using the method described in the examples below, is preferably 150°C or higher. When the melting point (Tm) of polymer (A) is within the above range, it has good heat resistance. The melting point (Tm) is more preferably 180°C or higher, and even more preferably 200°C or higher. There is no particular upper limit to the melting point (Tm), but for example, it is 500°C or lower, preferably 280°C or lower. The melting point (Tm) tends to depend on the stereoregularity of polymer (A) and the content of constituent units (a-ii) in polymer (A). Therefore, the melting point (Tm) can be adjusted by using the olefin polymerization catalyst described later and by controlling the content of constituent units (a-ii).

[0029] <Method for producing polymer (A)> Polymer (A) can be obtained by polymerizing polymerizable monomers such as 4-methyl-1-pentene, which will be the constituent units of polymer (A), in the presence of an olefin polymerization catalyst, using a known method.

[0030] Examples of olefin polymerization catalysts that can be used in the production of polymer (A) include Ziegler-Natta catalysts and metallocene catalysts. A preferred Ziegler-Natta catalyst is, for example, the solid titanium catalyst component [A-9] described in International Publication No. 2006 / 054613. Other preferred metallocene catalysts include, for example, the metallocene catalysts described in International Publication No. 01 / 53369, International Publication No. 01 / 27124, Japanese Patent Publication No. 3-193796, Japanese Patent Publication No. 02-41303, International Publication No. 06 / 025540, or International Publication No. 2014 / 123212. Furthermore, polymer (A) can also be obtained by polymerizing polymerizable monomers such as 4-methyl-1-pentene, which form the constituent units of polymer (A), based on the method described in International Publication No. 2004 / 87775.

[0031] Polymer (A) may be a polymer prepared to satisfy requirement (AI) by heat-treating a polymer that has been produced using the catalyst, etc., in an extruder or mixer, etc. Polymer (A) may be a polymer prepared to satisfy requirement (AI) by heat-treating a commercially available 4-methyl-1-pentene polymer in an extruder or mixer. An example of such a commercially available product is TPX manufactured by Mitsui Chemicals, Inc.

[0032] [Polymer (B)] The flexible tube contains polymer (B), thereby providing good flexibility. Polymer (B) satisfies the following requirement (BI). In the following description, the structural unit derived from 4-methyl-1-pentene may be referred to as "structural unit (bi)". Similarly, the structural unit derived from α-olefins having 2 to 4 carbon atoms may be referred to as "structural unit (b-iii)".

[0033] <Requirements (BI)> Polymer (B) contains 50.0 to 95.0 mol% of structural units derived from 4-methyl-1-pentene and 5.0 to 50.0 mol% of structural units derived from α-olefins having 2 to 4 carbon atoms.

[0034] The content (UB1) of constituent unit (bi) in polymer (B) is preferably 50.0 to 90.0 mol%, more preferably 50.0 to 87.0 mol%, even more preferably 60.0 to 87.0 mol%, and particularly preferably 70.0 to 87.0 mol% (provided that the sum of the content of constituent unit (bi) and the content of constituent unit (b-iii) is 100 mol%). The content (UB3) of constituent unit (b-iii) in polymer (B) is preferably 10.0 to 50.0 mol%, more preferably 13.0 to 50.0 mol%, even more preferably 13.0 to 40.0 mol%, and particularly preferably 13.0 to 30.0 mol% (provided that the sum of the content of constituent unit (bi) and the content of constituent unit (b-iii) is 100 mol%). UB1 and UB3 are determined by the method described in the examples. Polymer (B) in which UB1 and UB3 are within the above range exhibits excellent release properties and flexibility. Therefore, flexible tubes containing polymer (B) in which UB1 and UB3 are within the above range also tend to exhibit excellent release properties and flexibility.

[0035] Examples of α-olefins used to derive the constituent unit (b-iii) include ethylene, propylene, and 1-butene, with propylene being preferred. The constituent unit (b-iii) may be derived from only one selected from the group consisting of α-olefins having 2 to 4 carbon atoms, or it may be derived from two or more selected from the group consisting of α-olefins having 2 to 4 carbon atoms.

[0036] A preferred embodiment of polymer (B) is a copolymer consisting only of structural unit (bi) and structural unit (b-iii). In this case, the sum of the content of structural unit (bi) and structural unit (b-iii) is 100 mol%.

[0037] Another preferred embodiment of polymer (B) is a copolymer that, in addition to structural units (bi) and (b-iii), contains a small amount, specifically 10 mol% or less, preferably 5 mol% or less, and more preferably 3 mol% or less, of structural units derived from 4-methyl-1-pentene and other polymerizable monomers other than α-olefins having 2 to 4 carbon atoms, in an amount that does not impair the purpose of the present invention. The other polymerizable monomer may be one type or two or more types.

[0038] Preferred examples of such other polymerizable monomers include monomers similar to the other polymerizable monomers in polymer (A).

[0039] Here, if polymer (B) contains structural units derived from other polymerizable monomers, it is preferable that the total content of structural unit (b-iii) and structural units derived from other polymerizable monomers satisfies the range of content of structural unit (b-iii). In this case, the total content of structural unit (bi), structural unit (b-iii), and structural units derived from other polymerizable monomers is 100 mol%.

[0040] <Intrinsic viscosity of polymer (B) in decalin at 135°C> The intrinsic viscosity [η] of polymer (B), measured in decalin at 135°C by the method described in the examples below, is preferably 0.5 to 5.0 dl / g, more preferably 1.0 to 3.0 dl / g, and even more preferably 1.0 to 2.0 dl / g. When the intrinsic viscosity [η] of polymer (B) falls within the aforementioned range, the fluidity during the molding of the flexible tube is good. The intrinsic viscosity [η] can be adjusted, for example, by the amount of hydrogen added during the polymerization process when producing polymer (B).

[0041] <Molecular weight and molecular weight distribution of polymer (B)> The weight-average molecular weight (Mw) of polymer (B) measured by the method described in the examples below is preferably 5,000 to 800,000, more preferably 15,000 to 500,000, in terms of polystyrene. Furthermore, the molecular weight distribution (Mw / Mn) obtained by dividing Mw by the number-average molecular weight Mn of polymer (B) is preferably 0.1 to 8.0, more preferably 0.5 to 4.0. When the weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of polymer (B) are within the above range, it exhibits excellent moldability and is preferable from the viewpoint of appearance and surface roughness. It is also preferable because the influence of low molecular weight polymers and low stereoregularity polymers derived from the composition distribution is reduced, and the mechanical strength of the resulting molded article does not decrease easily. The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of polymer (B) can be adjusted, for example, by the amount of hydrogen added in the polymerization process when producing polymer (B).

[0042] <MFR of polymer (B)> The melt flow rate (MFR) of polymer (B), measured in accordance with ASTM D1238 at 230°C and a 2.16 kg load, is preferably in the range of 1 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, and even more preferably 5 to 20 g / 10 min. An MFR within this range is preferable in terms of fluidity when forming into a flexible tube.

[0043] <Density of polymer (B)> The density of polymer (B) measured by the method described in the examples below is preferably 700 to 1,000 kg / m³. 3 More comfortably 800-900 kg / m 3 Therefore, if the density of polymer (B) is within the above range, the amount of resin used when manufacturing a molded product (such as a flexible tube) of the same volume can be reduced, which is preferable from the viewpoint of reducing environmental impact. The density of polymer (B) can be adjusted, for example, by the amount of hydrogen added in the polymerization process when manufacturing polymer (B).

[0044] <Melting point and glass transition temperature of polymer (B)> Preferably, the melting point (Tm) of polymer (B), as measured by differential scanning calorimeter (DSC) using the method described in the examples below, is not observed. When the melting point (Tm) of polymer (B) is not observed, it exhibits excellent flexibility. Furthermore, the glass transition temperature (Tg) of polymer (B), as measured by differential scanning calorimeter (DSC) using the method described in the examples below, is preferably 10 to 100°C, and more preferably 15 to 50°C.

[0045] The melting point (Tm) and glass transition temperature (Tg) values ​​tend to depend on the stereoregularity of polymer (B) and the content of constituent units (b-iii) in polymer (B). Therefore, the melting point (Tm) and glass transition temperature (Tg) can be adjusted by using the olefin polymerization catalyst described later and by controlling the content of constituent units (b-iii).

[0046] <Tensile elongation at fracture of polymer (B)> The tensile elongation at break of polymer (B), measured in accordance with JIS K 7127 by the method described in the examples below, is preferably 150 to 1000%, more preferably 200 to 800%, and even more preferably 300 to 600%. If the tensile elongation at break of polymer (B) is within the above range, the flexibility of the flexible tube is better.

[0047] <Method for producing polymer (B)> Polymer (B) can be obtained by polymerizing polymerizable monomers such as 4-methyl-1-pentene, which form the constituent units of polymer (B), using the same method as for producing polymer (A). Alternatively, polymer (B) may be obtained by heat-treating a polymer that has already been produced, similar to polymer (A). Polymer (B) may be a commercially available 4-methyl-1-pentene polymer. An example of such a commercially available product is the absortomer manufactured by Mitsui Chemicals, Inc.

[0048] Polymer (A) may be a modified polymer obtained by graft-modifying the unmodified polymer (A) with a graft component. The same applies to polymer (B). A method for graft-modifying polymer (A) or polymer (B) with a graft component includes, for example, first dissolving the unmodified polymer (A) or polymer (B) in a known organic solvent (e.g., toluene), then adding the graft component and a radical polymerization initiator, mixing them, and heating (specifically, melt-mixing).

[0049] Examples of graft components include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, vinyl ester compounds, and thiol group-containing ethylenically unsaturated compounds. Preferred graft components include unsaturated carboxylic acids and / or unsaturated carboxylic acid anhydrides. The graft component is preferably an unsaturated carboxylic acid anhydride, and more preferably maleic anhydride. The graft component may be used alone or in combination of two or more types.

[0050] Examples of radical polymerization initiators include organic peroxides and organic peresters. A single radical polymerization initiator may be used, or two or more may be used in combination.

[0051] <Resin composition (X)> The resin composition (X) is a resin composition containing 60 to 95 parts by mass of polymer (A) and 5 to 40 parts by mass of polymer (B) (provided that the total of polymer (A) and polymer (B) is 100 parts by mass). Preferably, the resin composition (X) contains 65 to 85 parts by mass of polymer (A) and 15 to 35 parts by mass of polymer (B), more preferably 65 to 80 parts by mass of polymer (A) and 20 to 35 parts by mass of polymer (B) (provided that the total of polymer (A) and polymer (B) is 100 parts by mass).

[0052] By containing polymer (A) and polymer (B) in such ratios, the layer containing resin composition (X) exhibits excellent flexibility and transparency. In one preferred embodiment, the resin composition (X) may consist only of the polymer (A) and the polymer (B) described above, but it may also contain additives to the extent that it does not impair the objectives of the present invention.

[0053] [Additives] The resin composition (X) according to the present invention may optionally contain additives, to the extent that they do not impair the effects of the present invention. Examples of additives include other polymer components other than the polymers (A) and (B) described above, leveling agents, defoaming agents, antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, surfactants, pigments, thixotropes, thickeners, tackifiers, surface modifiers, anti-settling agents, weathering agents, pigment dispersants, antistatic agents, fillers, antifungal agents, and silane coupling agents.

[0054] Additives may be used individually or in combination of two or more types. However, from the viewpoint of better exhibiting the effects of the present invention, the total content of polymer (A) and polymer (B) in the resin composition (X) is preferably 70 to 100% by mass, and more preferably 90 to 100% by mass. Furthermore, from the viewpoint of transparency, the content of the fluorine compound in the resin composition (X) is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and even more preferably the resin composition (X) is substantially free of the fluorine compound.

[0055] The resin composition (X) according to the present invention can be obtained by simultaneously or sequentially compounding the polymer (A), polymer (B), and optionally additives described above using known methods.

[0056] [Flexible tube] The flexible pipe of the present invention is a flexible pipe having a layer containing the above-mentioned resin composition (X), and is not particularly limited as long as it is a flexible tubular molded body. For example, it may be a tube, hose or pipe, or it may be a covering material for covering cables such as electric wires. Furthermore, the flexible pipe of the present invention may be a flexible pipe having a layer made of the above-mentioned resin composition (X). Furthermore, the flexible tube of the present invention may consist of a single molded layer of a resin composition (X) containing the above polymer (A) and polymer (B), and optionally an additive, or it may consist of a laminate formed by laminating a layer made of the resin composition (X) with other layers.

[0057] In a preferred embodiment, the flexible tube of the present invention is a flexible tube consisting only of a layer made of a resin composition (X) containing the polymer (A) and polymer (B), that is, a flexible tube formed by molding the resin composition (X) alone into a tubular shape. Such a flexible tube has excellent transparency and superior flexibility compared to conventionally known flexible tubes such as single-layer tubes made of 4-methyl-1-pentene resins. It also has excellent heat resistance, chemical resistance, and electrical insulation properties inherent to 4-methyl-1-pentene resins.

[0058] In another preferred embodiment, the flexible tube of the present invention is a flexible tube having a laminated structure in which layers made of a resin composition (X) containing the polymer (A) and polymer (B) are laminated with other layers. When the flexible tube has a laminated structure (is a laminate), the layer structure is not particularly limited, and may be a two-layer structure of a layer made of the resin composition (X) and other layers, a multilayer structure of a layer made of the resin composition (X) and multiple other layers, or a multilayer structure of multiple layers made of the resin composition (X) and one or more other layers. The other layers may be provided throughout the entire flexible tube or in part thereto.

[0059] Examples of such laminated structures include a layer made of resin composition (X) / other layers, a layer made of resin composition (X) / other layers / a layer made of resin composition (X), and other layers / a layer made of resin composition (X) / other layers. When the flexible tube of the present invention has a laminated structure, the layer made of resin composition (X) may constitute the outer layer, inner layer, or intermediate layer of the laminated tube, but preferably it is the outer layer and / or inner layer of the laminated tube, and more preferably the inner layer of the laminated tube (inner surface layer of the flexible tube), in which the effects of the excellent properties of the layer made of resin composition (X) can be favorably enjoyed.

[0060] Other layers that can constitute the flexible tube of the present invention are not particularly limited, as long as they are flexible, but examples include layers made of various resins such as polyolefins, modified polyolefins, polyamides, polyesters, polyurethanes, perfluoroalkoxyalkanes (PFAs) and fluororesins such as perfluoroethylenepropene copolymers (FEPs), and elastomers; layers made of fibers such as metal wires, carbon fibers, glass fibers, synthetic fibers, and natural fibers, or their woven or nonwoven fabrics; layers made of paper, metal foils, and film-like materials; and layers made of composite materials thereof.

[0061] [Method for manufacturing flexible pipes] The flexible tube of the present invention can be obtained by molding a resin composition (X) containing the above polymers (A) and (B), and optionally additives, by known methods. The molding method is not particularly limited, but for example, A method of melt-extruding a resin composition (X) into a tubular shape using a melt-extrude molding machine equipped with a cylindrical die. A method of forming a tube by extruding a resin composition (X) onto a core material, and then removing the core material. A method of forming a resin composition (X) into a sheet, laminating it with other layers as needed, and then forming it into a tube by a known method. These are some examples.

[0062] Furthermore, the flexible tube of the present invention can also have a so-called multi-lumen structure, in which case it can be obtained, for example, by a molding apparatus described in Japanese Patent Publication No. 2017-202615 or Japanese Patent Publication No. 2024-106310.

[0063] Furthermore, if the flexible tube of the present invention has a multilayer structure comprising a layer containing a resin composition (X) and other layers, it can be manufactured by appropriately applying known methods for manufacturing multilayer tubular structures, depending on the desired structure and the material of the other layers. Examples include a method of manufacturing a tubular object made of a resin composition (X) and then providing the other layers on its surface; a method of providing a layer made of a resin composition (X) on the surface of a tubular object made of other layers; a method of forming a laminate having a layer made of a resin composition (X) and other layers into a tubular shape; a method of simultaneously extruding the resin composition (X) and other resins into a tubular shape by co-extrusion or the like; and methods combining these.

[0064] [Uses of flexible pipes] The flexible tube of the present invention is a tubular material with flexibility and can be used without restriction for various applications. It can be suitably used alone or in combination with other materials as a tube, hose, pipe, or cable covering material. The tube, hose, pipe, or cable covering material of the present invention comprises the flexible pipe of the present invention as described above. That is, the tube, hose, pipe, or cable covering material of the present invention may consist only of the flexible pipe of the present invention, or it may be composed in combination with a component made of another material. The component made of the other material may or may not be flexible. The flexible pipe, tube, hose or pipe, or cable covering material of the present invention exhibits particularly excellent flexibility and transparency in the portion containing the resin composition (X). [Examples]

[0065] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the spirit of the invention. The various physical properties of the copolymer, resin composition, and molded article in the examples were measured or evaluated by the following methods.

[0066] <Method for measuring the physical properties of polymers> 〔composition〕 The content (mol%) of 4-methyl-1-pentene and comonomer in the copolymer is: 13 The measurement was performed by 13C-NMR. The measurement conditions were as follows: Measurement equipment: Nuclear magnetic resonance spectrometer (ECP500 model, manufactured by JEOL Ltd.) Observation nucleus: 13 C(125MHz) Sequence: Single-pulse proton decoupling Pulse width: 4.7 μs (45° pulse) Repeat time: 5.5 seconds Total number of times: 10,000 or more Solvent: Orthodichlorobenzene / deuterated benzene (volume ratio: 80 / 20) mixed solvent Sample concentration: 55 mg / 0.6 mL Measurement temperature: 120℃ Chemical shift baseline: 27.50 ppm

[0067] [Intrinsic viscosity [η]] The intrinsic viscosity [η] of the copolymer was measured using an Ubbelohde viscometer in decalin solvent at 135°C. Specifically, approximately 20 mg of powdered copolymer was dissolved in 25 ml of decalin, and the specific viscosity ηsp was measured in an oil bath at 135°C using an Ubbelohde viscometer. After diluting this decalin solution by adding 5 ml of decalin, the specific viscosity ηsp was measured in the same manner as above. This dilution procedure was repeated two more times, and the intrinsic viscosity [η] (unit: dl / g) was determined by extrapolating the concentration (C) to 0 as ηsp / C (see equation (1) below). [η]=lim(ηsp / C) (C→0)...Equation (1)

[0068] [Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn)] The weight-average molecular weight (Mw) of the copolymer, and the molecular weight distribution (Mw / Mn), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), were calculated using a standard polystyrene equivalent method with gel permeation chromatography (GPC). The measurement conditions were as follows. Measurement device: GPC (ALC / GPC 150-C plus type, with integrated differential refractometer detector, manufactured by Waters) Columns: Two GMH6-HT (manufactured by Tosoh Corporation) and two GMH6-HTL (manufactured by Tosoh Corporation) connected in series. Eluent: o-dichlorobenzene Column temperature: 140℃ Flow rate: 1.0mL / min

[0069] [Melt Flow Rate (MFR)] The melt flow rate (MFR) of copolymer (B) was measured in accordance with ASTM D1238 at 230°C with a load of 2.16 kg. Copolymer (A) was measured at 260°C with a load of 5 kg. The unit is g / 10 min.

[0070] 〔density〕 The density of the copolymer was measured in accordance with JIS K7112 (density gradient tube method).

[0071] [Melting point (Tm) and glass transition temperature (Tg)] The melting point (Tm) and glass transition temperature (Tg) of the copolymers were measured using a differential scanning calorimeter (DSC220C model, manufactured by Seiko Instruments Inc.). For polymer (A), only the melting point (Tm) was measured, while for polymer (B), both the melting point (Tm) and the glass transition temperature (Tg) were measured. Approximately 5 mg of the copolymer was sealed in an aluminum pan for measurement and heated from room temperature to 200°C at a rate of 10°C / min. To completely melt the copolymer, it was held at 200°C for 5 minutes, and then cooled to -50°C at a rate of 10°C / min. After being left at -50°C for 5 minutes, a second heating was performed to 200°C at a rate of 10°C / min to determine the melting point (Tm) and glass transition temperature (Tg). For the melting point (Tm), the peak temperature (°C) during this second heating was used as the melting point (Tm) of the copolymer.

[0072] [Tensile elongation at fracture] The tensile elongation at break of polymer (B) was measured in accordance with JIS K 7127.

[0073] [Raw materials] Polymer (A) was polymer (A-1) as shown below, and polymer (B) was polymer (B-1) as shown below.

[0074] <Potassium (A-1)>: Following the method of Comparative Example 9 in International Publication No. 2006 / 054613, the amount of monomers charged was changed so that the content of the constituent units derived from 4-methyl-1-pentene, 1-hexadecene, and 1-octadecene in the resulting copolymer was as shown in Table 1 below, and the amount of hydrogen during polymerization was adjusted so that the composition and physical properties were as shown in Table 1 below, thereby obtaining 4-methyl-1-pentene·1-hexadecene·1-octadecene copolymer (A-1). Subsequently, granulation was performed using a twin-screw extruder (model: BT-30 (screw diameter 30 mmφ, L / D=46)) manufactured by Plastics Engineering Laboratory Co., Ltd., under the conditions of a set temperature of 270°C, a resin extrusion rate of 60 g / min, and 200 rpm, to obtain pellets. The results of the measurements of the above various physical properties are shown in Table 1.

[0075] <Polymer (B-1)> [Manufacturing example] A 1.5 L stainless steel autoclave with a stirring blade, thoroughly purged with nitrogen, was charged at 23°C with 300 ml of n-hexane (dried on activated alumina under a dry nitrogen atmosphere) and 450 ml of 4-methyl-1-pentene. 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL) was then added to the autoclave, and the mixture was stirred.

[0076] Next, the autoclave was heated to an internal temperature of 60°C and pressurized with propylene to a total pressure (gauge pressure) of 0.40 MPa. Subsequently, 0.34 ml of a toluene solution containing 1 mmol of methylaluminoxane (in terms of Al) and 0.01 mmol of diphenylmethylene (1-ethyl-3-t-butyl-cyclopentadienyl)(2,7-di-t-butyl-fluorenyl)zirconium dichloride, which had been prepared in advance, was injected into the autoclave under nitrogen pressure to initiate the polymerization reaction. During the polymerization reaction, the temperature of the autoclave was adjusted to maintain an internal temperature of 60°C.

[0077] Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave under pressure with nitrogen to stop the polymerization reaction, and then the autoclave was depressurized to atmospheric pressure. After depressurization, acetone was added to the reaction solution while stirring to obtain a polymerization reaction product containing the solvent.

[0078] Next, the polymerization reaction product containing the obtained solvent was dried under reduced pressure at 100°C for 12 hours to obtain 36.9 g of powdered polymer (B-1). The results of the measurement of various physical properties of the obtained polymer (B-1) are shown in Table 1.

[0079] The obtained polymer (B-1) was granulated using a twin-screw extruder (manufactured by Plastics Industry Co., Ltd., φ=30mm, L / D=27, cylinder temperature: 230℃) to obtain pellets.

[0080] [Table 1]

[0081] [Example 1] (Fabrication of resin tubes) 7 kg of polymer (A-1) pellets were mixed with 3 kg of polymer (B-1) pellets in a Henschel mixer (manufactured by Mitsui Miike Seisakusho Co., Ltd., 150 L) and stirred at 1460 rpm for 2 minutes to obtain composition (X-1). (That is, composition (X-1) was obtained with polymer (A-1) at 70% by mass, polymer (B-1) at 30% by mass, and the total of polymers (A-1) and (B-1) at 100% by mass.)

[0082] Composition (X-1) was melt-extruded into a tubular shape at 295°C using a melt extrusion molding machine (PCM-43, manufactured by Ikegai) equipped with a cylindrical die, to obtain a resin tube with an inner diameter of 4 mm and an outer diameter of 6 mm.

[0083] [Comparative Example 1] (Fabrication of resin tubes) The resin tube was molded in the same manner as in Example 1, except that polymer (A) was used instead of composition (X1).

[0084] [Comparative Example 2] (Fabrication of resin tubes) The resin tube was molded in the same manner as in Example 1, except that only PFA (perfluoroalkoxyalkane) was used instead of composition (X1).

[0085] [Mechanical properties of the tube (flexural modulus)] The resin tubes obtained in the above examples and comparative examples were used as test specimens, and the flexural modulus (unit: MPa) of the test specimens was measured using a precision universal testing machine (AG-XP, manufactured by Shimadzu Corporation) under the conditions of a chuck distance of 50 mm, a tensile speed of 10 mm / min, and a temperature of 23°C. The results were evaluated according to the following criteria. The obtained results are shown in Table 2. Judgment criteria A: Less than 550 MPa B:550MPa or more

[0086] [Manufacturing of resin plates] Each resin used to create the resin tubes in the above examples and comparative examples, i.e., composition (X-1), polymer (A-1), or PFA, was press-molded using a hydraulic hot press (NS-50) manufactured by Shinto Metal Industries Co., Ltd. at 260°C for 10 minutes under a pressure of 10 MPa to obtain a plate with a thickness of 1 mm.

[0087] <Hayes (Transparency)> Using the 1mm thick resin plate obtained above, the haze was measured in accordance with JIS K 7136 using a HM-150 haze / transmittance meter (D65 light source) manufactured by Murakami Color Technology Laboratory Co., Ltd., and evaluated according to the following criteria. The results obtained are shown in Table 2. Judgment criteria A: Less than 20% B: 20% or more

[0088] [Table 2]

Claims

1. 60 to 95 parts by mass of polymer (A) that satisfies the following requirements (A-I), and A flexible tube having a layer containing a resin composition (X) comprising 5 to 40 parts by mass of polymer (B) that satisfies the following requirement (B-I) (wherein the total of polymer (A) and polymer (B) is 100 parts by mass). (A-I): Polymer (A) contains 50.0 to 100 mol% of structural units derived from 4-methyl-1-pentene and 0 to 50.0 mol% of structural units derived from α-olefins having 5 to 20 carbon atoms (excluding 4-methyl-1-pentene). (B-I): Polymer (B) contains 50.0 to 95.0 mol% of structural units derived from 4-methyl-1-pentene and 5.0 to 50.0 mol% of structural units derived from α-olefins having 2 to 4 carbon atoms.

2. The flexible tube according to claim 1, wherein the total content of polymer (A) and polymer (B) in the resin composition (X) is 70 to 100% by mass.

3. The flexible tube according to claim 1 or 2, wherein the tensile elongation at break of the polymer (B), as measured in accordance with JIS K 7127, is 150 to 1000%.

4. The flexible tube according to claim 1 or 2, wherein the glass transition temperature (Tg) of the polymer (B), as measured by a differential scanning calorimeter (DSC), is 10 to 100°C.

5. The flexible tube according to claim 1 or 2, wherein the content of the fluorine compound in the resin composition (X) is 0 to 10% by mass.

6. A tube, hose, pipe, or cable covering material comprising the flexible tube described in claim 1 or 2.

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