JP6317970B2 - Resin composition, molded body, pipe and coiled pipe - Google Patents

Description

The present invention relates to a resin composition, a molded article, a pipe and a coiled pipe comprising the resin composition.
In detail, it is related with the resin composition used suitably for the pipe for water supply and hot water supply.

  Plastic pipes are widely used because they are lightweight, easy to lay, and difficult to break in an earthquake disaster. Moreover, since plastic piping is rich in flexibility, it is wound in a coil shape and sent to the site, and the coil is unwound and laid according to the required amount.

  Polyethylene pipes and polybutene pipes are known as plastic pipes. Among these, polybutene pipes are preferable because they are superior in pressure strength and wear resistance compared to polyethylene pipes (for example, Patent Documents 1 to 4), but are inferior in stress relaxation properties (return stress). Therefore, for example, when a polybutene pipe is wound in a coil shape, a large bending stress is applied. Therefore, in order to return the pipe to a straight line and keep it in a straight line at the facility site, a bending is required. A large force is needed to remove the stress. For this reason, the laying work efficiency of the polybutene pipe may deteriorate depending on the bending radius at the time of construction. Further, in the conventional polybutene pipe, there is a possibility that a crack caused by the stress portion may occur. For this reason, there has been a strong demand for a polybutene pipe capable of suppressing cracks, which can greatly reduce stress and facilitate facility work.

  On the other hand, 4-methyl-1-pentene / α-olefin copolymer is used in various fields as a resin excellent in light weight, chemical resistance, heat resistance and the like. Patent Document 5 proposes a copolymer composition containing the copolymer that is lightweight and has excellent stress relaxation properties.

However, there is room for improvement in the strength of a molded body made of the copolymer composition, particularly a pipe.
Therefore, there has been a strong demand for a resin composition that is lightweight and has a very excellent stress relaxation property and strength, and particularly suitable for a pipe.

JP 58-084839 A Japanese Patent Laid-Open No. 63-213542 JP 63-213543 A Japanese Unexamined Patent Publication No. 63-213544 WO2011 / 055803 Publication

  The present invention is to solve the above-described points, and is a light-weighted, extremely excellent stress relaxation property and strength compared to conventional plastic piping, and particularly a molded body with a small reaction force, particularly a pipe (piping). An object is to provide a suitable resin composition and the pipe and coiled pipe.

  More specifically, it is particularly lightweight, excellent in strength, and has a large stress relaxation (low return stress). For example, when a coil is unwound at a facility site, a desired shape, for example, a straight line shape, is obtained immediately. The purpose is to provide a pipe that is easy to return.

The present inventors have conducted extensive consider as a result, we have completed the present invention.
The resin composition of the present invention comprises a poly-1-butene resin (A) 99 to 1 part by weight and a 4-methyl-1-pentene / α-olefin copolymer that satisfies the following requirements (a) to (d) ( B) 1 to 99 parts by weight (provided that the total of the resin (A) and the copolymer (B) is 100 parts by weight).

(A) 50-90 mol% of the structural unit (i) derived from 4-methyl-1-pentene and the structural unit (ii) derived from an α-olefin (excluding 4-methyl-1-pentene) (The total of the structural unit (i) and the structural unit (ii) is 100 mol%),
(B) The intrinsic viscosity [η] measured at 135 ° C. in decalin is in the range of 0.1 to 5.0 dL / g.
(C) The ratio (molecular weight distribution; Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 1.0 to 3.5. It is in,
(D) The density is in the range of 870 to 830 kg / m ³ .

The molded product of the present invention is characterized by comprising the resin composition of the present invention.
The pipe of the present invention is characterized by comprising the resin composition of the present invention.
The coil-wound pipe of the present invention is characterized in that a pipe comprising the resin composition of the present invention is wound in a coil shape.

According to the resin composition of the present invention, it is possible to suitably obtain a molded article, particularly a pipe, which is lightweight, excellent in stress relaxation and strength, and has a small reaction force.
According to the pipe comprising the resin composition of the present invention, for example, the force required to bend the pipe wound in a coil shape in the direction opposite to the radius of curvature of the coil winding is small, and a desired shape, for example, Since it can be returned to a straight line and is lighter in weight, facility work can be performed more efficiently than in the past. Moreover, according to this pipe, generation | occurrence | production of the crack resulting from this stress part can also be suppressed.

FIG. 1 is a diagram showing the relationship between the strength (YS) obtained by the samples described in Examples and Comparative Examples and the stress relaxation rate.

The present invention will be described below.
The resin composition of the present invention contains a poly-1-butene resin (A) and a specific 4-methyl-1-pentene / α-olefin copolymer (B) in a specific ratio.

  In the present specification, poly-1-butene resin (A) is referred to as “resin (A)”, and 4-methyl-1-pentene / α-olefin copolymer (B) is referred to as “copolymer (B)”. And the resin composition may be referred to as “composition (X)”.

[Poly-1-butene resin (A)]
The poly-1-butene resin (A) used in the present invention is usually 80 to 100 mol% of 1-butene, preferably 90 to 100 mol%, and 0 to 20 mol of α-olefin other than 1-butene. %, Preferably 0 to 10 mol% (provided that the total amount of 1-butene and α-olefin is 100 mol%), or a 1-butene homopolymer or 1- It is a butene / α-olefin copolymer.

  Examples of α-olefins other than 1-butene include, for example, α-olefins having 2 to 10 carbon atoms, specifically ethylene, propylene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-hexene, Heptene, 1-octene, 1-nonene, 1-decene and the like can be mentioned. These α-olefins may be used alone or in combination.

  The melt flow rate (MFR; ASTM D 1238, 190 ° C., 2.16 kg load) of the resin (A) is preferably 0.01 to 50 g / 10 minutes, more preferably 0.01 to 30 g / 10 minutes. Poly-1-butene resin having a melt flow rate within the above range is flexible and excellent in creep resistance, impact resistance, wear resistance, chemical resistance, stress cracking resistance, and the like. preferable.

  Resin (A) has the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) method (molecular weight distribution: Mw / Mn). Is not particularly limited as long as it is obtained, but usually 2.1 or more, particularly 3 to 30 is preferable, and 3 to 10 is more preferable.

The resin (A) has an isotactic pentad fraction (mmmm%) by NMR method, which is not particularly limited, but is preferably 85% or more, more preferably 90% or more.
The isotactic pentad fraction indicates the abundance of isotactic chains in pentad units in the molecular chain measured using ¹³ C-NMR, and includes 5 1-butene monomer units. It is the fraction of butene monomer units at the center of the chain that are continuously meso-bonded. In addition, this isotactic pentad fraction (mmmm%) can be calculated | required by the method of Unexamined-Japanese-Patent No. 2007-186664, for example.

  The resin (A) is not particularly limited as long as the melting point (Tm) measured by a differential scanning calorimeter (DSC) obtains the effects of the present invention, but is preferably 100 ° C. or higher, more preferably 110 ° C. or higher. More preferably, it is preferably 120 ° C. or higher. When the melting point of the resin (A) is in the above range, the heat resistant creep property is excellent.

Resin (A) is a known process, for example, in the presence of a Ziegler-Natta catalyst or a metallocene catalyst, only 1-butene is polymerized, or 1-butene and an α-olefin other than 1-butene are copolymerized. Can be prepared. A production example of the resin (A) is described in, for example, WO02 / 02659.
Commercially available poly-1-butene such as Mitsui Chemical Co., Ltd. and buron can also be used.

[4-Methyl-1-pentene / α-olefin copolymer (B)]
The 4-methyl-1-pentene / α-olefin copolymer (B) used in the present invention satisfies the following requirements (a) to (d).

Requirement (a);
The copolymer (B) includes a structural unit (i) derived from 4-methyl-1-pentene, a structural unit (ii) derived from an α-olefin (excluding 4-methyl-1-pentene), and The structural unit (i) is composed of 50 to 90 mol% and the structural unit (ii) is composed of 50 to 10 mol%.

  The copolymer (B) is preferably 55 to 90 mol%, more preferably 68 to 90 mol in that the copolymer (B) can obtain a pipe having a higher relaxation rate and excellent strength. %, More preferably more than 80 mol% and 90 mol% or less, still more preferably 82 to 87 mol%, and the structural unit (ii) is preferably 10 to 45 mol%, more preferably 10 to 32 mol%. It is a copolymer composed of mol%, more preferably 10 mol% or more and less than 20 mol%, and still more preferably 13 to 18 mol% (however, the total of the structural unit (i) and the structural unit (ii) is 100 Mol%).

  If the proportion of the structural unit (i) is less than 50 mol%, the heat resistance and stress relaxation properties in the room temperature region may be low, and if it exceeds 90 mol%, the flexibility of the material may be impaired. is there.

  Further, when the proportion of the structural unit (i) exceeds 55 mol%, preferably 68 mol% or more, the compatibility between the copolymer (B) and the resin (A) becomes good, and the stress relaxation rate. Is preferable.

  Furthermore, when the proportion of the structural unit (i) exceeds 80 mol%, preferably 82 mol% or more, the resulting copolymer (B) becomes crystalline. Therefore, the degree of crystallinity of the composition (X1) containing the copolymer (B) is increased, and the stress relaxation rate is increased while maintaining the same strength as the resin (A), which is preferable. Further, the composition (X1) contains an amorphous copolymer (B), and when compared with the composition (X2) having the same degree of strength (YS), slipping of molecules is likely to occur. Since the stress relaxation rate increases, it is preferable.

  Examples of the α-olefin that leads to the structural unit (ii) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, and 1-tetradecene. , 1-hexadecene, 1-octadecene, 1-eicosene and the like, a linear α-olefin having 2 to 20 carbon atoms, preferably 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms, 3- Methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, Examples thereof include branched α-olefins having 5 to 20 carbon atoms, preferably 5 to 15 carbon atoms, such as 4-ethyl-1-hexene and 3-ethyl-1-hexene. Among these, ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable, ethylene and propylene are particularly preferable, a relaxation rate is higher, and a pipe excellent in strength can be obtained. Propylene is most preferred.

  Here, in one embodiment of the present invention, the 4-methyl-1-pentene / α-olefin copolymer (B) is composed only of the structural unit (i) and the first structural unit (ii). However, if the 4-methyl-1-pentene / α-olefin copolymer (B) is a small amount (for example, 10 mol% or less) that does not impair the object of the present invention, the structural unit (i) and In addition to one structural unit (ii), as the second structural unit (ii), from other monomer that is neither 4-methyl-1-pentene nor an α-olefin leading to the first structural unit (ii) A derived structural unit may be further included. As such other preferred specific examples, when the 4-methyl-1-pentene / α-olefin copolymer (B) is a 4-methyl-1-pentene / propylene copolymer, ethylene, Examples include 1-butene, 1-hexene, 1-octene, 5-vinyl-2-norbornene, and 5-ethylidene-2-norbornene.

Requirement (b);
The intrinsic viscosity [η] measured at 135 ° C. in decalin of the copolymer (B) is in the range of 0.1 to 5.0 (dL / g). The details of the measurement conditions and the like are as described in the column of Examples described later.

The intrinsic viscosity [η] is preferably 0.5 to 4.0 (dL / g), more preferably 0.5 to 3.5 (dL / g).
As described later, when hydrogen is used together during polymerization, the molecular weight can be controlled, and the intrinsic viscosity [η] can be adjusted by freely obtaining from a low molecular weight body to a high molecular weight body.
If the intrinsic viscosity [η] is less than 0.1 dL / g or more than 5.0 dL / g, moldability and strength when formed into a pipe may be impaired.

Requirement (c);
The ratio (molecular weight distribution; Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by the GPC method of the copolymer (B) is usually in the range of 1.0 to 3.5. It is in. The details of the measurement conditions and the like are as described in the column of Examples described later.

  Mw / Mn is preferably 1.2 to 3.0, more preferably 1.5 to 2.8. If Mw / Mn is more than 3.5, the influence of the low molecular weight, low stereoregular polymer derived from the composition distribution is concerned, and stickiness may occur in the resulting pipe.

  Here, in the present invention, if the catalyst described later is used, the copolymer (B) satisfying the requirement (c) can be obtained within the range of the intrinsic viscosity [η] indicated by the requirement (b). it can. In addition, the value of said Mw / Mn and the following Mw is a value at the time of measuring by the method employ | adopted in the Example mentioned later.

  The weight average molecular weight (Mw) measured by the GPC method of the copolymer (B) is preferably from 500 to 10,000,000, more preferably from 1,000 to 5,000,000, even more preferably, in terms of polystyrene. Is 1,000 to 2,500,000.

Requirement (d);
The density of the copolymer (B) (ASTM D 1505, measured by an underwater substitution method) is 870 to 830 kg / m ³ , preferably 865 to 830 kg / m ³ , and more preferably 855 to 830 kg / m ³ . The details of the measurement conditions and the like are as described in the column of Examples described later.

The density can be appropriately changed depending on the comonomer composition ratio of the copolymer (B). The copolymer (B) having a density within the above range is advantageous in terms of light weight.
The melt flow rate (MFR; ASTM D1238, 230 ° C., 2.16 kg load) of the copolymer (B) is not particularly limited as long as the effects of the present invention are obtained, but usually 0.1 to 100 g / 10 min, preferably 1 It is in the range of ˜50 g / 10 minutes, more preferably 3 to 20 g / 10 minutes.

  The copolymer (B) is not particularly limited as long as the melting point (Tm) measured by a differential scanning calorimeter (DSC) obtains the effects of the present invention, but is preferably 180 ° C. or lower, more preferably not observed. 140 ° C. or lower or not recognized, more preferably 140 ° C. or lower. The melting point of the copolymer (B) can be arbitrarily changed depending on the comonomer type and comonomer composition. When the melting point is in the above range, the copolymer is excellent in flexibility.

The copolymer (B) is not particularly limited as long as the parameter B value indicating the randomness of the chain distribution of the comonomer measured by ¹³ C-NMR is obtained, but it is 0.9 to 1.5. Preferably, it is 0.9 to 1.3, more preferably 0.9 to 1.2. When the parameter B value is within the above range, the randomness of the chain distribution of the monomers in the polymer is good, the composition distribution in the polymer is lost, and, for example, the stress relaxation property and strength are excellent.

(Production method of copolymer (B))
The copolymer (B) is obtained by polymerizing 4-methyl-1-pentene with the above-mentioned specific α-olefin and, if necessary, the polymerizable compound in the presence of an olefin polymerization catalyst by a known method. Can be obtained.

Among the above-mentioned olefin polymerization catalysts, a metallocene catalyst can be mentioned as a preferred embodiment of the catalyst for producing the 4-methyl-1-pentene copolymer (B).
Preferred metallocene catalysts include those described in WO 01/53369, WO 01/27124, JP-A-3-19396, JP-A-02-41303, or WO 06/025540. And metallocene catalysts described in the above.

(Resin composition)
In the resin composition of the present invention, the poly-1-butene resin (A) is 99 to 1 part by weight, preferably 99 to 35 parts by weight, more preferably 99 to 40 parts by weight, and still more preferably 90 to 40 parts by weight. Even more preferably, 90 parts by weight or less and more than 50 parts by weight, most preferably 90 to 60 parts by weight, and 1 to 99 parts by weight of the 4-methyl-1-pentene / α-olefin copolymer (B), Preferably 1 to 65 parts by weight, more preferably 1 to 60 parts by weight, still more preferably 10 to 60 parts by weight, still more preferably 10 to less than 50 parts by weight, most preferably 10 to 40 parts by weight (provided that (A ) And (B) is 100 parts by weight). Within this range, a resin composition can be obtained that is lightweight and can suitably obtain a molded article having high strength, stress relaxation, flexibility, scratch resistance, and abrasion resistance.

  The composition (X) preferably satisfies the following requirement (Xa), more preferably satisfies any of the requirements (Xa) to (Xc), and further satisfies the requirements (Xa) and (Xb). It is preferable to satisfy all of the requirements (Xa) to (Xc).

・ Requirements (Xa)
The stress relaxation rate of the test piece obtained using the composition (X) is usually 0.3 or more, preferably 0.4 or more. The method for preparing the test piece and the method for calculating the stress relaxation rate are as described in the Examples section. The maximum value of the stress relaxation rate is 1.

・ Requirements (Xb)
The strength of the test piece obtained using the composition (X) is 10 MPa or more, preferably 10 to 30 MPa, more preferably 12 to 20 MPa. The method for preparing the test piece and the method for measuring the strength are as described in the Examples section.

・ Requirements (Xc)
The reaction force of the test piece (pipe) obtained using the composition (X) is 100 N or less, preferably 90 N or less, more preferably 80 N or less. The method for preparing the test piece and the method for measuring the reaction force are as described in the Examples section.

(Additive)
The resin composition of the present invention includes a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an anti-slip agent, an anti-blocking agent, an antifogging agent, a nucleating agent, a lubricant, and a pigment as long as the object of the present invention is not impaired. Additives such as dyes, plasticizers, anti-aging agents, hydrochloric acid absorbents, antioxidants and secondary antioxidants may be blended as necessary. The blending amount is not particularly limited, but usually it is preferably about 0.1 to 1 part by weight per 100 parts by weight of the composition (X). Furthermore, if necessary, foaming agents, foaming aids, vulcanizing agents, vulcanization accelerators, vulcanizing aids, reinforcing agents, fillers, softeners, anti-aging agents (stabilizers), processing aids, activators Other components such as a hygroscopic agent, a crosslinking agent, a co-crosslinking agent, a crosslinking aid, a pressure-sensitive adhesive, and a flame retardant can be blended.

(Production method of resin composition (X))
The resin composition (X) is prepared by blending the resin (A), the copolymer (B), and, if necessary, the above various additives in the above ranges, and various known methods such as a multistage polymerization method, Method of mixing with plast mill, Henschel mixer, V-blender, ribbon blender, tumbler blender, kneader ruder, etc., or after mixing, melt kneading with a single screw extruder, twin screw extruder, kneader, Banbury mixer, etc., granulation or grinding It can be manufactured by adopting the method.

[Molded body]
The resin composition of the present invention can be widely used for conventionally known polyolefin applications, and can be used as molded articles having various other shapes.

  The molded body is obtained by a known thermoforming method such as extrusion molding, injection molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, calendar molding, foam molding, powder slush molding, etc. It is done.

Resin composition (X) is lightweight and can suitably obtain a molded article excellent in stress relaxation properties and strength.
In addition, the pipe comprising the resin composition of the present invention is lightweight and has excellent stress relaxation properties and strength. Therefore, the pipe is particularly suitable for a water supply / hot water supply pipe.

  The shape of the pipe comprising the resin composition (X), in particular, the water / hot water supply pipe is not particularly limited, and the cross-sectional shape may be circular, polygonal, or any other shape. In addition, this pipe usually has an inner diameter of 3 to 1400 mm, an outer diameter of 5 to 1600 mm, and a wall thickness of 1 to 100 mm. The pipe can be obtained by a conventionally known extrusion method.

  The pipe is flexible and can have a bend. When the pipe has a bent portion, the bend radius (minimum bend radius) may have a bent portion that is 50 times or less the outer diameter of the pipe. The bending portion in the pipe may be formed by any known method for manufacturing, storing, and piping the pipe, and may be raw bending at normal temperature or bending by heating. The pipe can be piped by a conventionally known pipe construction method, and is particularly suitable for the sheath pipe construction method.

  The pipe may be inserted into a protective tube or a sheath tube to form a double piping structure. There is no restriction | limiting in particular in the material of a protection tube or a sheath tube, A conventionally well-known protection tube or sheath tube can be used. The piping method for forming the double piping structure according to the present invention is not particularly limited, and may be piped after forming the double piping structure in advance. It may be formed.

  In the present invention, a coil-wound pipe obtained by winding a pipe in a coil shape (also referred to as a pipe coil in the present invention) can be suitably obtained. According to this pipe, even if it is wound in a coil shape or stress is applied, it can be easily returned to a shape required for a facility, for example, a straight line shape. Therefore, facility work can be performed very efficiently as compared with the prior art. Further, cracks due to the stress portion are not generated.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these Examples.
[Measurement conditions]
The measurement conditions of the physical properties in the examples are as follows.

(MFR)
The MFR of the resin (A) was measured at 190 ° C. with a load of 2.16 kg according to ASTM D 1238.
The MFR of the copolymer (B) was measured at 230 ° C. and a load of 2.16 kg in accordance with ASTM D 1238.

(composition)
The 4-methyl-1-pentene and α-olefin contents in the resin (A) and the copolymer (B) were measured by ¹³ C-NMR using the following apparatus and conditions. Using an ECP500 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd., a mixed solvent of orthodichlorobenzene / heavy benzene (80/20% by volume) as a solvent, sample concentration 55 mg / 0.6 mL, measurement temperature 120 ° C., observation nucleus ¹³ C (125 MHz), sequence is single pulse proton decoupling, pulse width is 4.7 μs (45 ° pulse), repetition time is 5.5 seconds, integration number is 10,000 times or more, 27.50 ppm as standard for chemical shift Measured as a value.

(Intrinsic viscosity)
The intrinsic viscosity [η] was measured at 135 ° C. using a decalin solvent.
(Molecular weight (Mw, Mn), molecular weight distribution (Mw / Mn))
The molecular weight of the resin (A) and the copolymer (B) was measured using a liquid chromatograph: Waters ALC / GPC 150-C plus type (with suggested refractometer detector integrated type), and GHS6-HT manufactured by Tosoh Corporation. × 2 and GMH6-HTL × 2 were connected in series, and o-dichlorobenzene was used as the mobile phase medium, and measurement was performed at 140 ° C. at a flow rate of 1.0 ml / min.

  Mw / Mn value was calculated by analyzing the obtained chromatogram by a known method using a calibration curve using a standard polystyrene sample. The measurement time per sample was 60 minutes.

(density)
The density of the copolymer (B) was calculated from the weight of each sample measured in water and in air using ALFA MIRAGE electronic hydrometer MD-300S in accordance with ASTM D 1505 (in-water substitution method).

(Isotactic Pendat fraction (mmmm fraction: [%]))
In a sample tube of a nuclear magnetic resonance apparatus (NMR; GSX-400 type manufactured by JEOL Ltd.), 50 mg of a sample (polybutene resin) is added, 0.5 ml of a solvent hexachlorobutadiene is added, and sonicated for 30 minutes. The sample was dissolved in a heating furnace at 0 ° C. When almost the entire amount of the sample was dissolved, 0.2 ml of deuterated benzene was added, and the sample was further heated and dissolved uniformly. At the time of uniform dissolution, the sample tube was sealed to obtain a measurement sample. The sample was measured under the following conditions using NMR.
Measurement nucleus: 13C
Observation frequency: 100.4 MHz
Pulse interval: 4.5 seconds Pulse width: 45 °
Measurement temperature: 115 ° C

  The isotactic index (II) was calculated by the following method. II (pentad) in the case of a 1-butene homopolymer has an area (S2) of 27.36 to 28.2 ppm relative to the total area (S1) of 26.1 to 28.2 ppm of methylene carbon and a mmmm peak at S2. Of the area of the low magnetic field side (S3). That is, it is calculated as II (mmmm%) of the homopolymer of 1-butene = (S2 + S3) / S1 × 100%. In the case of 1-butene / propylene copolymer, it is calculated as II (mmmm%) = S2 / S1 × 100%.

(Melting point (Tm))
The melting point (Tm) of the polymer was measured with a differential scanning calorimeter (DSC) using a DSC220C apparatus manufactured by Seiko Instruments Inc. Samples 7-12 mg obtained from the polymerization were sealed in an aluminum pan and heated from room temperature to 200 ° C. at 10 ° C./min. The sample was held at 200 ° C. for 5 minutes to completely melt and then cooled to −50 ° C. at 10 ° C./min. After 5 minutes at −50 ° C., the sample was heated again to 200 ° C. at 10 ° C./min. This peak temperature in the second heating (second time) was adopted as the melting point (Tm).

(Shore hardness measurement)
For the measurement of Shore hardness (conforming to JIS K6253), a press sheet with a thickness of 3 mm is used as a measurement sample, and the scale immediately after the start of contact with the Shore A hardness meter or Shore D hardness meter and after 15 seconds from the start of contact with the needle I read.

Further, a change ΔHS in Shore hardness value defined by the following equation was obtained.
ΔHS = (Shore hardness value immediately after the start of pressing needle contact−Shore hardness value 15 seconds after the start of pressing needle contact)
Here, the Shore hardness was measured using a Shore A hardness meter in principle, but for a measurement sample in which the Shore A hardness was difficult to measure, a Shore D hardness meter was used instead.

[Methods for producing various measurement press sheets]
The resin compositions, resins (A), and copolymers (B) of Examples and Comparative Examples were formed into a sheet at a pressure of 10 MPa using a hydraulic hot press set at 190 ° C. In the case of a sheet of 2 mm thickness (spacer shape: 200 × 200 × 2 mm thickness), the remaining heat is applied for 5 minutes, pressurized at 10 MPa for 5 minutes, and then compressed at 10 MPa using another hot press set at 20 ° C. A sample for measurement was prepared by cooling for 5 minutes. Samples prepared by the above method were used for various physical property evaluation samples.

(Stress relaxation rate)
An ASTM IV dumbbell test piece was punched from the press sheet produced under the above conditions, and this was mounted on an Instron universal testing machine. Next, the dumbbell is pulled at a temperature of 23 ° C. at a pulling speed of 50 mm / min until the strain between chucks becomes 10%. When the strain reaches 10%, the deformation is stopped and the stress (Y0) at that time is recorded. Let stand for 1 hour as it is, and determine the stress (Y1) after 1 hour. The stress relaxation rate was calculated by (Y0−Y1) / Y0.

(Strength (YS): MPa)
An ASTM IV dumbbell test piece was punched from the press sheet produced under the above conditions, and this was installed in an Instron universal testing machine. A tensile test was performed at a temperature of 23 ° C. and a tensile speed of 50 mm / min. Asked.

[Measurement of reaction force (N)]
Using the resin compositions of Examples and Comparative Examples, a straight pipe having an outer diameter of 17 mm and a wall thickness of 2.1 mm was prepared under the conditions of an extruder temperature of 190 ° C., a molding speed of 10 m / min, and a cooling water temperature of 15 ° C. A sample having a length of 40 cm was prepared. Next, with one end of the straight pipe fixed and the other end attached with a device that can measure the load (for example, a spring only), the pipe is bent in 1 second so as to form an arc with a radius of 102 mm from the linear shape. It was. The state was left as it was for 60 seconds, the load after 60 seconds was recorded, and this was used as the reaction force.

[Synthesis Example 1]
(Synthesis of copolymer (B1))
A SUS autoclave with a stirring blade having a capacity of 1.5 liters sufficiently purged with nitrogen was charged with 300 ml of normal hexane at 23 ° C. (dried in a dry nitrogen atmosphere and activated alumina) and 450 ml of 4-methyl-1-pentene. . The autoclave was charged with 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL), and the stirrer was rotated.

  Next, the autoclave was heated to an internal temperature of 60 ° C. and pressurized with propylene so that the total pressure was 0.40 MPa (gauge pressure). Subsequently, 1 mmol of methylaluminoxane prepared in advance, diphenylmethylene (1-ethyl-3-tert-butyl-cyclopentadienyl) (2,7-di-tert-butyl-fluorenyl) zirconium in terms of Al Polymerization was initiated by injecting 0.34 ml of a toluene solution containing 0.01 mmol of dichloride into the autoclave with nitrogen. During the polymerization reaction, the temperature was adjusted so that the internal temperature of the autoclave was 60 ° C. Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave with nitrogen to stop the polymerization, and the autoclave was depressurized to atmospheric pressure. Acetone was poured into the reaction solution with stirring.

  The obtained powdered polymer containing the solvent was dried at 100 ° C. under reduced pressure for 12 hours. The obtained polymer was 36.9 g, and the 4-methyl-1-pentene content in the polymer was 72 mol% and the propylene content was 28 mol%. Table 1 shows the measurement results of various physical properties.

[Synthesis Example 2]
(Synthesis of copolymer (B2))
A SUS autoclave with a stirring blade having a capacity of 1.5 liters sufficiently purged with nitrogen was charged with 300 ml of normal hexane at 23 ° C. (dried in a dry nitrogen atmosphere and activated alumina) and 450 ml of 4-methyl-1-pentene. . The autoclave was charged with 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL), and the stirrer was rotated.

  Next, the autoclave was heated to an internal temperature of 60 ° C. and pressurized with propylene so that the total pressure was 0.19 MPa (gauge pressure). Subsequently, 1 mmol of methylaluminoxane prepared in advance, diphenylmethylene (1-ethyl-3-tert-butyl-cyclopentadienyl) (2,7-di-tert-butyl-fluorenyl) zirconium in terms of Al Polymerization was initiated by injecting 0.34 ml of a toluene solution containing 0.01 mmol of dichloride into the autoclave with nitrogen. During the polymerization reaction, the temperature was adjusted so that the internal temperature of the autoclave was 60 ° C. Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave with nitrogen to stop the polymerization, and the autoclave was depressurized to atmospheric pressure. Acetone was poured into the reaction solution with stirring.

  The obtained powdered polymer containing the solvent was dried at 100 ° C. under reduced pressure for 12 hours. The obtained polymer was 44.0 g, and the 4-methyl-1-pentene content in the polymer was 85 mol% and the propylene content was 15 mol%. Table 1 shows the measurement results of various physical properties.

[Synthesis Example 3]
(Preparation of solid titanium catalyst component)
Anhydrous magnesium chloride (6.0 kg, 63 mol), decane (26.6 L) and 2-ethylhexyl alcohol (29.2 L) (189 mol) were reacted by heating at 140 ° C. for 4 hours to obtain a homogeneous solution. Thereafter, 1.59 kg (7.88 mol) of 2-isopropyl-1,3-dimethoxypropane was added to the solution, and the mixture was further stirred and mixed at 110 ° C. for 1 hour.

  After cooling the obtained homogeneous solution to room temperature, 37.0 kg of the solution obtained by the above method was added dropwise to 120 L (1080 mol) of titanium tetrachloride maintained at −24 ° C. over 2.5 hours. Then, the temperature of the obtained solution was raised over 6 hours, and when it reached 110 ° C., 0.68 kg (3.37 mol) of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was added. The solid was collected by hot filtration, put in 132 L of titanium tetrachloride and reslurried, and then the slurry was heated again at 110 ° C. for 2 hours to be reacted.

  Thereafter, the solid part was again collected from the reaction mixture by hot filtration, and washed with decane and hexane at 90 ° C. When no titanium compound was detected in the cleaning solution, the cleaning was stopped to obtain a solid titanium catalyst component.

  A part of the hexane slurry of the solid titanium catalyst component was collected and dried, and the dried product was analyzed. The mass composition of the solid titanium catalyst component was 3.0% titanium, 57% chlorine, 17% magnesium, and 18.0% 2-isopropyl-2-isobutyl-1,3-dimethoxypropane.

(Synthesis of resin (A2))
In a continuous polymerization vessel with an internal volume of 200 L, hexane is converted to 73 L / h, 1-butene is set to 16 kg / h, propylene is set to 0.05 kg / h, hydrogen is set to 10 NL / h, and the solid titanium catalyst component is converted to titanium atoms to 0.38 mmol / h. 1-butene and propylene were copolymerized while supplying 38 mmol of triethylaluminum per hour and 1.3 mmol of cyclohexylmethyldimethoxysilane per hour to obtain 4.8 kg of a copolymer. The copolymerization temperature was 60 ° C., the average residence time was 0.8 hours, and the total pressure was 3 × 10 ⁻¹ MPa · G.

To the obtained polymer, 1.0 part by weight of high density polyethylene having a density of 0.965 g / cm ³ (ASTM D1505) and MFR 13 g / 10 min (ASTM D1238, 2.16 kg, 190 ° C.) was added, and the screw diameter was 40 mm. The pellets were granulated using a machine. Table 1 shows the physical properties of the obtained resin.

[Synthesis Example 4]
(Synthesis of resin (A3))
In the production of the above 1-butene / propylene copolymer, the polymerization was repeated under the same conditions as described above except that the amount of propylene was changed to 0.15 kg per hour to produce a copolymer.

To the obtained polymer, 1.0 part by weight of high density polyethylene having a density of 0.965 g / cm ³ (ASTM D1505) and MFR 13 g / 10 min (ASTM D1238, 2.16 kg, 190 ° C.) was added, and the screw diameter was 40 mm. The pellets were granulated using a machine. Table 1 shows the physical properties of the obtained resin.

[Synthesis Example 5]
(Synthesis of resin (A4))
In the production of the above 1-butene / propylene copolymer, the polymerization was repeated under the same conditions as above except that the amount of propylene was changed to 0.26 kg per hour to produce a copolymer.

To the obtained polymer, 1.0 part by weight of high density polyethylene having a density of 0.965 g / cm ³ (ASTM D1505) and MFR 13 g / 10 min (ASTM D1238, 2.16 kg, 190 ° C.) was added, and the screw diameter was 40 mm. The pellets were granulated using a machine. Table 1 shows the physical properties of the obtained resin.

[Synthesis Example 6]
(Synthesis of resin (A1))
In the production of the 1-butene / propylene copolymer, polymerization was repeated under the same conditions as above without using propylene as a copolymerization component to produce a poly-1-butene polymer.

To the obtained polymer, 1.0 part by weight of high density polyethylene having a density of 0.965 g / cm ³ (ASTM D1505) and MFR 13 g / 10 min (ASTM D1238, 2.16 kg, 190 ° C.) was added, and the screw diameter was 40 mm. The pellets were granulated using a machine. Table 1 shows the physical properties of the obtained resin.

[Examples 1-3]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A1) and the copolymer (B1) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 4 to 7]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A1) and the copolymer (B2) were melt-mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 8 to 9]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A2) and the copolymer (B1) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 10 to 11]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A2) and the copolymer (B2) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 12 to 13]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A3) and the copolymer (B1) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 14 to 15]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A3) and the copolymer (B2) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 16 to 17]
Using a 40 mm uniaxial extruder set at 200 ° C., the resin (A4) and the copolymer (B1) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Examples 18 to 19]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A4) and the copolymer (B2) were melted and mixed at the ratios shown in Table 2 to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Comparative Example 1]
Using a 40 mm single screw extruder set at 200 ° C., the resin (A1) was melted and mixed to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Comparative Examples 2 to 4]
Pellets were prepared in the same manner as in Comparative Example 1 except that the resin (A1) was changed to any of the resins (A2) to (A4). According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

[Comparative Examples 5-6]
Pellets were prepared in the same manner as in Comparative Example 1 except that the resin (A1) was changed to the copolymer (B1) or (B2). According to the above method, various samples were prepared from the pellets, and the yield point stress and the stress relaxation rate were measured. The obtained results are shown in Table 2.
In Comparative Examples 5 and 6, the pipe could not be molded because the elastic modulus was too small, and the reaction force was not measured.

Example 20
Using a 40 mm single screw extruder set at 200 ° C., 20 parts by weight of the resin (A1) and 80 parts by weight of the copolymer (B2) were melt-mixed to prepare pellets. According to the above method, various samples were prepared from the pellets, and yield point stress, stress relaxation rate and reaction force were measured. The obtained results are shown in Table 2.

As shown in the Examples and Comparative Examples, it can be seen that the stress relaxation rate of the obtained molded product is increased by mixing a specific amount of the copolymer (B) with the resin (A) according to the present invention.
Moreover, it turns out that the molded object which contains the resin composition of this invention has a suitable intensity | strength from a Example and a comparative example, a stress relaxation property is large, and reaction force is small.
As is clear from the above comparative example, the difference in stress relaxation rate between the copolymers (B1) and (B2) is almost 0.03, but the same amount was added to the resin (A). When the stress relaxation rates are compared, the difference in the stress relaxation rates is large. This is one of the features of the present invention.

  The pipe comprising the resin composition of the present invention is lightweight and has excellent stress relaxation properties and strength. According to this pipe, even if it is wound in a coil shape and stress is applied, it can be easily returned to a shape required for a facility, for example, a straight line shape. Therefore, facility work can be performed very efficiently as compared with the prior art. Moreover, since the crack resulting from this stress part is not produced, this pipe is industrially useful.

Claims (4)

99-1 parts by weight of poly-1-butene resin (A);
1-99 parts by weight of 4-methyl-1-pentene / α-olefin copolymer (B) satisfying the following requirements (a) to (d) (however, the total of resin (A) and copolymer (B) is 100 parts by weight).
(A) The structural unit (i) derived from 4-methyl-1-pentene is derived from α-olefin (excluding 4-methyl-1-pentene) exceeding 80 mol% and 90 mol% or less. The structural unit (ii) is composed of 10 mol% or more and less than 20 mol% (provided that the total of the structural unit (i) and the structural unit (ii) is 100 mol%).
(B) The intrinsic viscosity [η] measured at 135 ° C. in decalin is in the range of 0.1 to 5.0 dL / g.
(C) The ratio (molecular weight distribution; Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 1.0 to 3.5. It is in,
(D) The density is in the range of 870 to 830 kg / m ³ . A molded article comprising the resin composition according to claim 1 . A pipe comprising the resin composition according to claim 1 . A coil-wound pipe in which a pipe comprising the resin composition according to claim 1 is wound in a coil shape.

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