JP2019143100A - Ethylene-based resin composition, master batch, molded product and crosslinked product - Google Patents

Abstract

To provide an ethylene-based resin composition capable of producing a crosslinked product with high production efficiency and high quality, a master batch and a molded product and to provide a crosslinked product having high quality.SOLUTION: The ethylene-based resin composition of the invention contains 100 pts.mass of (a) an ethylene-based polymer and 0.05 to 5.0 pts.mass of (b) a silanol condensation catalyst in which the total of components having a molecular weight of 1,000,000 or more is 3.0% or less; the total of components having a molecular weight of less than 1,000 is 4.5% or less; and the total of a compositional fraction γof (γ) a component having the highest mobility measured by the pulse NMR and a compositional fraction βof (β) a component having an intermediate mobility is 40% or more. The ethylene-based resin composition is a master batch comprising the ethylene-based resin composition. The molded product is a molded product formed of a melt-kneaded product of the master batch and a silane-grafted polyethylene. The crosslinked product is a crosslinked product of the molded product.SELECTED DRAWING: None

Description

  The present invention relates to an ethylene-based resin composition, a master batch, a molded body, and a crosslinked body.

  Conventionally, a crosslinked product obtained by crosslinking a polyethylene resin is easy to be molded or crosslinked, for example, tubular bodies such as pipes, hoses and tubes, insulating coating materials used for conductors such as electric wires and cables, various containers, and It is used in various applications such as sheets. For example, pipes (cross-linked polyethylene pipes) that can be used in the construction field have higher creep characteristics at high temperatures, longer durability, and workability than vinyl chloride pipes and copper pipes that are also used in the construction field. In recent years, cross-linked polyethylene pipes are being used more frequently in the construction field, specifically for water supply / drainage, hot water supply, and heating.

JP-A-57-170913 Japanese Patent Laid-Open No. 11-248046 JP 2000-38481 A JP 2011-11497 A JP 2012-136596 A

  Here, as one of the typical methods for producing a crosslinked product of polyethylene, a silane compound such as vinylalkoxysilane is melt-kneaded with polyolefin and subjected to graft polymerization, and then the silane-modified polyethylene is formed into a desired shape. In addition, there is known a method for producing by causing crosslinking by placing the catalyst under conditions such as exposure to warm water or high-temperature steam in the presence of a catalyst (for example, see Patent Documents 1 to 5). In this production method, when the silane compound is melt-kneaded into the polyolefin, a catalyst for water crosslinking is added together with the silane compound, or after graft polymerization, the catalyst is melt-kneaded into the graft-polymerized polyethylene. Thus, the catalyst is present in polyethylene.

  However, in the technology disclosed in the above-mentioned patent documents, there is room for improvement in the production efficiency of the crosslinked body and the quality of the obtained crosslinked body, and further improvement thereof has been demanded.

  This invention is made | formed in view of the said problem, and it aims at providing the ethylene-type resin composition, masterbatch, and molded object which can produce a crosslinked body with high production efficiency by high quality. Moreover, an object of this invention is to provide the crosslinked body which has high quality.

  As a result of intensive studies to solve the above-mentioned problems, the present invention has been found to be suitable for the purpose by using an ethylene resin composition having the following specific properties. It came.

That is, the invention relating to the ethylene-based resin composition is as follows.
[1]
(A) 100 parts by mass of an ethylene polymer, and (b) 0.05 part by mass or more and 5.0 parts by mass or less of a silanol condensation catalyst,
In gel permeation chromatograph (GPC) measurement, the total of components having a weight average molecular weight of 1,000,000 or more is 3.0% or less, and the total of components having a weight average molecular weight of less than 1000 is 4.5% or less,
In the measurement by the solid echo method of pulsed NMR, when the free induction decay curve at 30 ° C. is approximated by three components, the composition fraction γ ₃₀ of the highest mobility component (γ) and the intermediate mobility component (β) Ethylene resin composition whose total with composition fraction (beta) ₃₀ is 40% or more.
[2]
The (a) ethylene polymer has a melt flow rate of 0.1 g / 10 min to 10.0 g / 10 min, a density of 935 kg / m ^{3 to} 960 kg / m ³ , and a number average molecular weight Mn in GPC measurement. The ethylene-based resin composition according to [1], wherein the weight average molecular weight Mw (Mw / Mn) is 3.0 or more and 10.0 or less.
[3]
(C) The ethylene-based resin composition according to [1] or [2] above, which contains a phenol-based antioxidant and (d) a phosphorus-based antioxidant.
[4]
The (a) ethylene polymer in which the contents of the (b) phenolic antioxidant and the (c) phosphorus antioxidant in the (a) ethylene polymer are each 20 ppm or less is used. The ethylene-based resin composition according to any one of [1] to [3].
[5]
(C) contains a phenolic antioxidant and (d) a phosphorus antioxidant,
[1] to [1], wherein the (a) ethylene polymer, the (b) silanol condensation catalyst, the (c) phenolic antioxidant, and the (d) phosphorus antioxidant are melt-kneaded. 4]. The ethylene-based resin composition according to any one of [4].
[6]
The ethylene resin composition according to any one of [1] to [5], wherein a total of components having a weight average molecular weight of less than 10,000 is 15.0% or more in GPC measurement of the ethylene resin composition. .
[7]
The ethylene resin composition according to any one of [1] to [6], wherein a component having a weight average molecular weight of 1,000,000 or more is 2.0% or less in GPC measurement of the ethylene resin composition.
[8]
In the pulsed NMR measurement of the ethylene resin composition, the total of the composition fraction γ ₃₀ of the component (γ) and the composition fraction β ₃ of the component (β) is 45% or more, [1] to [7] The ethylene-based resin composition according to any one of [7].
[9]
The masterbatch which consists of an ethylene-type resin composition in any one of said [1]-[8].
[10]
A molded product of a melt-kneaded product of the master batch according to [9] above and silane-grafted polyethylene.
[11]
A cross-linked product of the molded product according to [10].

  ADVANTAGE OF THE INVENTION According to this invention, the ethylene-type resin composition, masterbatch, and molded object which can produce a crosslinked body with high production efficiency and high quality can be provided. Moreover, according to this invention, the crosslinked body which has high quality can be provided.

  Hereinafter, a mode for carrying out the invention of the present application (hereinafter referred to as “the present embodiment”) will be described in more detail. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention. Deformation is possible.

[Ethylene resin composition]
The ethylene resin composition of this embodiment contains (a) 100 parts by mass of an ethylene polymer and (b) 0.05 parts by mass or more and 5.0 parts by mass or less of a silanol condensation catalyst. The ethylene-based polymer composition is a total of components having a weight average molecular weight of 1 million or more and a weight average molecular weight of less than 1000 in a gel permeation chromatograph (GPC) measurement. Is less than 4.5%, and in the measurement by the solid echo method of pulsed NMR, when the free induction decay curve at 30 ° C. is approximated by three components, the composition fraction γ ₃₀ of the highest mobility component (γ) and the intermediate The total of the motility component (β) and the composition fraction β ₃₀ is 40% or more. According to the polyethylene resin composition, a crosslinked product can be produced with high production efficiency and high quality. Specifically, for example, the polyethylene resin composition can be melt-kneaded with a grafted polyethylene resin, and further molded and crosslinked, and the catalyst in the polyethylene resin composition and the grafted polyethylene resin are mixed. It becomes easier to mix more uniformly, and a crosslinked product can be produced with high production efficiency and high quality.

  Here, in the ethylene-based resin composition of the present embodiment, the total of components having a weight average molecular weight of 1,000,000 or more is 3.0% or less, preferably 2.0%, in GPC measurement of the ethylene-based resin composition. Or less, more preferably 1.0% or less. When the total of components having a weight average molecular weight of 1,000,000 or more is 3.0% or less, when a molded product or a crosslinked product is produced using an ethylene-based resin composition, there is a problem that causes defects in appearance. Since generation | occurrence | production can be reduced, a crosslinked body can be manufactured with high quality.

  In the GPC measurement of the ethylene resin composition, the ethylene resin composition of the present embodiment has a total weight average molecular weight of less than 1000 components of 4.5% or less, preferably less than 4.0%, More preferably, it is less than 3.5%. By causing the total of components having a weight average molecular weight of less than 1000 to be 4.5% or less, in melt-kneading when producing a molded body using an ethylene-based resin composition, such low molecular weight components are caused. Smoke can be suppressed. Therefore, it is possible to produce a crosslinked product with high production efficiency while suppressing deterioration of the environment during the production process of the crosslinked product.

  Furthermore, the ethylene-based resin composition of the present embodiment can be cross-linked after being melt-kneaded and molded with, for example, a silane-grafted polyethylene, which will be described later. In these processes, the component having a molecular weight of less than 1000 is included in the ethylene-based resin composition. , Since there is little entanglement between molecules, there is a concern that it is weak against external pressure and stress, and may be a starting point for cracking of the molded product, and the total of components having a molecular weight of less than 1000 is 4.5% or less The concern can be suppressed.

  In the ethylene resin composition of the present embodiment, the total of components having a weight average molecular weight of less than 10,000 is preferably 10.0% or more, more preferably 15.0, in GPC measurement of the ethylene resin composition. % Or more, and more preferably 20.0% or more. A component having a weight average molecular weight of less than 10,000 is an important component for smoothly performing melt-kneading and molding when a molded product is produced using an ethylene-based resin composition. Therefore, by setting the total of the components to 10.0% or more, it is possible to smoothly perform melt-kneading and molding, and to reduce the occurrence of unevenness of the molded body that causes appearance defects. That is, by making the total of the components 10.0% or more, the crosslinked product can be produced with higher production efficiency and higher quality.

  The total value of the component having a weight average molecular weight of 1,000,000 or more, the component having a weight average molecular weight of less than 1,000, and the component having a weight average molecular weight of less than 10,000 in the ethylene resin composition is not particularly limited. The polymerization temperature can be adjusted by polymerizing the polymer, introducing hydrogen during polymerization, residence time during polymerization, and catalyst type. Specifically, when the polymerization temperature is increased or the amount of hydrogenation during polymerization is increased, the amount of components having a molecular weight of 1,000,000 or more is decreased, and the amount of components having a molecular weight of less than 1,000 is increased. be able to. Further, when the residence time at the time of polymerization is increased, the molecular weight distribution is widened, so that it is possible to adjust so that both components having a molecular weight of 1,000,000 or more and components having a molecular weight of less than 1,000 increase. In addition, by using a metallocene catalyst as a polymerization catalyst, the molecular weight distribution can be narrower than when a Ziegler-Natta catalyst is used.

In the ethylene-based resin composition of the present embodiment, the component having the highest mobility (γ) when the free induction decay curve at 30 ° C. is approximated by three components in the pulsed NMR solid echo method of the ethylene-based resin composition. The total of the composition fraction γ ₃₀ and the composition fraction β ₃₀ of the intermediate motility component (β) is 40% or more. Further, total of the composition fraction beta ₃₀ component composition fraction gamma ₃₀ and components (γ) (β), is preferably 45% or more, more preferably 50% or more.

  Here, pulse NMR is an analysis method for evaluating the mobility of the entire polymer molecular chain system, and the mobility can be evaluated by measuring the relaxation time of the resin composition and the signal intensity at that time. . In general, the lower the mobility of the polymer chain, the shorter the relaxation time, so that the signal intensity decays faster, and the relative signal intensity when the initial signal intensity is 100% decreases in a short time. Moreover, since the relaxation time becomes longer as the mobility of the polymer chain is higher, the decay of the signal intensity is delayed, and the relative signal intensity when the initial signal intensity is 100% is gradually decreased over a long time.

When the free induction decay curve at 30 ° C. obtained by measurement by the solid-echo method of pulsed NMR of an ethylene-based resin composition is approximated by three components, the signal obtained by the measurement is the component having the lowest mobility in the resin composition. (Α), the intermediate motility component (β) and the most motility component (γ) can be classified, and the component fractions α ₃₀ , β ₃₀ and γ ₃₀ can be determined.

Specific composition fractions α ₃₀ , β ₃₀ and γ ₃₀ can be determined as follows. By fitting the free induction decay curve at 30 ° C. measured by the solid-state method of pulsed NMR using the following (Equation 1), the component with the lowest mobility (α) and the component with intermediate mobility Can be approximated to the component (β) and the component having the highest mobility to the three components of component (γ), and each composition fraction can be obtained by approximation to the three components.
M (t) = αexp (− (1/2) (t / T _α ) ² ) sinbt / bt + βexp (− (1 / Wa) (t / T _β ) ^Wa ) + γexp (−t / T _γ ). (Formula 1)
α: Composition ratio of α component T _α : Relaxation time of α component (unit: msec)
β: Composition ratio of β component T _β : Relaxation time of β component (unit: msec)
γ: Composition fraction of γ component T _γ : Relaxation time of γ component (unit: msec)
t: Observation time (unit: msec)
Wa: Shape factor b: Shape factor More specifically, the shape factor can be measured by the method described in Examples described later.

And in this invention, the degree of the mobility of the polymer molecular chain grasped | ascertained by the measurement of pulse NMR with content of the specific molecular weight component in the above-mentioned ethylene-type resin composition is ethylene type which concerns on this embodiment. It has been found that it is related to the quality of a molded product and a crosslinked product obtained by melt-kneading using a resin composition. That is, the molded product and the crosslinked product are silane grafting agents in which the components such as (a) an ethylene polymer and (b) a silanol condensation catalyst contained in the ethylene resin composition are kneaded when the molded product is produced. Or it is calculated | required to mix with silane graft | grafting polyethylene uniformly. With most motile component (gamma) of the composition fraction gamma ₃₀ and the intermediate motility component (beta) Total 40% or more between the composition fraction beta ₃₀ of, contained in the ethylene-based resin composition The dispersibility of each component such as (a) an ethylene-based polymer and (b) a silanol condensation catalyst can be sufficiently increased in melt-kneading at the time of producing a molded article. Therefore, it is possible to produce a crosslinked product with high production efficiency while reducing the occurrence of unevenness of the molded product causing the appearance defect.

In the present embodiment, as a method for controlling the sum of the values of the composition fraction beta ₃₀ of the most motile high component (gamma) of the composition fraction gamma ₃₀ and the intermediate motility component (beta) is Although not particularly limited, for example, the polymerization temperature of the ethylene polymer is set to 85 ° C. or less, the average residence time in the reactor during polymerization is set to 5 hours or less, and the drying conditions of the powder after polymerization are set. Dry at a temperature of 110 ° C. or less for 3 hours or less, then dry in an air flow of 60 ° C. or less (preferably 30 ° C. or more) for 1 minute or more, and further melt and knead the resin composition to a liquid such as water of 80 ° C. or less. (Preferably 30 ° C. or higher) for 5 seconds to 2 minutes.

Moreover, the following method is also mentioned as a method of controlling the total value of the composition fraction γ ₃₀ and the composition fraction β ₃₀ . In the production of the ethylene resin composition, pellets or powder can be used as the (a) ethylene polymer at the time of production, and at least a part of the powdery (a) ethylene polymer is used for the most movement. it can be controlled so as to increase the sum of the values of the composition fraction beta ₃₀ sex high component (gamma) of the composition fraction gamma ₃₀ and the intermediate motility component (beta). The reason is not clear, but the powdery (a) ethylene polymer is powdery and has no excessive heat history after synthesis. Therefore, it melts quickly during melt-kneading in the production of an ethylene-based resin composition. The (b) silanol condensation catalyst and the like in the resin-based resin composition can be more uniformly mixed with the (a) ethylene-based polymer. And since (b) silanol condensation catalyst etc. exists uniformly in an ethylene-type resin composition, for example, (b) suppressing the induction of crystallization of the ethylene polymer by the uneven distribution (b) silanol condensation catalyst etc. it can be, thereby making it possible to relatively increase the composition fraction beta ₃₀ of the most motile high component (gamma) of the composition fraction gamma ₃₀ and the intermediate motility component (beta).

  In the case where the additive components (components other than the component (a)) including powders such as (c) a phenolic antioxidant and (d) a phosphoric acid antioxidant, which can be optionally contained, are powdery It is preferable to use (a) ethylene polymer powder having a mass that is at least half of the total mass of the components in the form of a mixture, and previously mixing with the additive components. And it is preferable to manufacture the ethylene-type resin composition by mixing the said mixture mixed beforehand and the remaining component.

[[(A) ethylene polymer]]
The (a) ethylene polymer used in this embodiment is not particularly limited, but is a copolymer of ethylene and an α-olefin copolymerizable with ethylene. Although it does not specifically limit as the said alpha olefin, For example, a C3-C20 alpha olefin is mentioned. The α-olefin can be represented by H ₂ C═CHR, where R is a linear or branched aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group, or aromatic. A hydrocarbon group is shown.

  Specific examples of the α-olefin include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1- Examples include tridecene and 1-tetradecene. Further, specific examples of the α-olefin are not particularly limited, and examples thereof include vinylcyclohexane, styrene, and derivatives thereof. Furthermore, the α-olefin may have a non-conjugated unsaturated bond, and the α-olefin is not particularly limited, but examples thereof include non-conjugated polyenes such as 1,5-hexadiene and 1,7-octadiene. It can also be used.

  Although it does not specifically limit as an alpha olefin, A propylene and 1-butene are preferable. The copolymer may be a ternary random polymer. As a comonomer contained in a copolymer, 1 type may be used individually and 2 or more types may be used together.

  Here, the MFR of the ethylene-based polymer (a) of the present embodiment is preferably 0.1 g / 10 min or more and 10.0 g / 10 min or less, more preferably 0.5 g / 10 min or more and 5.0 g / 10 min. It is below, More preferably, they are 3.0 g / 10min or more and 5.0 g / 10min or less. (A) When the MFR of the ethylene polymer is 0.1 g / 10 min or more, the moldability is excellent and the pipe surface is smooth. In addition, since the resin pressure during melt molding and shear heat generation can be reduced, it is possible to suppress resin degradation during molding and the like, and it is difficult for resin to decompose in the extruder, so smoke is generated during processing. Less likely to occur. On the other hand, when the MFR is 10.0 g / 10 min or less, a crosslinked pipe having excellent durability is obtained.

  (A) The MFR of the ethylene polymer can be controlled by the temperature during polymerization, the amount of hydrogen to be added, and the like. Specifically, the MFR of the ethylene polymer can be controlled to increase by increasing the temperature during polymerization or increasing the amount of hydrogenation. The MFR can be measured by the method described in the examples.

(A) The density of the ethylene-based polymer is preferably 935 kg / m ³ or more and 960 kg / m ³ or less, more preferably 935 kg / m ³ or more and 950 kg / m ³ or less, and still more preferably 939 kg / m ^3. above 950 kg / ^{m 3} or less, most preferably 945 kg / ^{m 3} or more 950 kg / ^{m 3} or less. (A) When the density of the ethylene-based polymer is 935 kg / m ³ or more, a crosslinked pipe having excellent durability can be obtained. Moreover, (a) Since the density of an ethylene-type polymer is 960 kg / m < ³ > or less, the bridge | crosslinking pipe which is excellent in a softness | flexibility and is easy to construct is obtained.

  (A) The density of the ethylene polymer can be controlled by the amount of α-olefin added. Specifically, the density of the ethylene polymer can be controlled to be reduced by increasing the amount of α-olefin. Moreover, the said density can be measured by the method as described in an Example.

  (A) The weight average molecular weight Mw (Mw / Mn) relative to the number average molecular weight Mn in the GPC measurement of the ethylene polymer is preferably 3.0 or more and 10.0 or less, more preferably 3.0 or more and 7. It is 0 or less, More preferably, it is 3.0 or more and 4.0 or less. When Mw / Mn is 3.0 or more and 10.0 or less, a more uniform ethylene-based resin composition can be produced. When Mw / Mn is 3.0 or more, each component in the ethylene resin composition can be more uniformly dispersed, and when Mw / Mn is 10.0 or less, the ethylene resin composition. The amount of the low molecular weight component in it can be reduced.

  (A) The molecular weight distribution of the ethylene-based polymer can be controlled by the catalyst used during production. When a metallocene catalyst is used as the polymerization catalyst, the molecular weight distribution becomes narrower than when a Ziegler-Natta catalyst is used. Moreover, the said molecular weight distribution can be measured by the method as described in an Example.

  (A) Ethylene polymer is (c) phenolic antioxidant and (d) phosphorus antioxidant, which will be described later, and each of (c) phenolic antioxidant and (d) phosphorus antioxidant The content is preferably 20 ppm or less. (A) When the content of these antioxidants in the ethylene polymer exceeds 20 ppm, the (a) the ethylene polymer is melt kneaded to oxidize when obtaining the ethylene resin composition according to the present embodiment. The inhibitor may be altered and the final crosslinked product may turn yellow. (A) When the content of these antioxidants is 20 ppm or less at the stage of the ethylene polymer, it is difficult for the antioxidants to be altered before becoming a final crosslinked body, and finally the crosslinked white color You can get a body.

[[[(A) Method for producing ethylene polymer]]]
The method for producing the ethylene-based polymer (a) of the present embodiment is not particularly limited, but at least ethylene and the above α-olefin are polymerized in the presence of a metallocene catalyst or a Ziegler-Natta catalyst. (A) It has the superposition | polymerization process of obtaining the ethylene-type polymer of embodiment. When a metallocene catalyst is used as the catalyst, a supported metallocene catalyst obtained from at least a support material, an organoaluminum compound, a borate compound having active hydrogen, a cyclopentadiene compound, and a transition metal compound of Group IV of the periodic table, and a liquid In the presence of a cocatalyst, at least ethylene and the above α-olefin can be polymerized to produce (a) an ethylene-based polymer of the present embodiment.

  (A) When using the said supported metallocene catalyst, the other metallocene catalyst, Ziegler-Natta catalyst, Phillips catalyst, etc. can also be used for the catalyst used for the manufacturing method of an ethylene-type polymer. By using the supported metallocene catalyst, (a) low molecular weight components in the ethylene polymer can be reduced. Although it does not specifically limit as a metallocene catalyst, For example, the thing of Unexamined-Japanese-Patent No. 2006-273777 can be used conveniently.

  The supported metallocene catalyst can be prepared and prepared from at least a support material, an organoaluminum compound, a borate compound having active hydrogen, a cyclopentadiene compound, and a group IV transition metal compound.

  The average particle size of the carrier substance is preferably 1.0 μm or more and 20 μm or less, more preferably 1.0 μm or more and 15 μm or less, and further preferably 2.0 μm or more and 10 μm or less. When the average particle size is 1.0 μm or more, the resulting polymer particles tend to be prevented from scattering and adhering. Moreover, when the average particle diameter is 20 μm or less, (a) the carrier substance remaining in the polyethylene polymer tends to suppress a decrease in smoothness of the surface of the crosslinked product. In addition, when polyethylene is extruded, the carrier substance remaining in the polyethylene tends to be clogged in the filter of the extruder, thereby increasing the pressure and suppressing a decrease in smoothness of the surface of the crosslinked body. The particle size distribution of the carrier material is preferably as narrow as possible, and the particle size distribution can be adjusted by removing fine particles and coarse particles by sieving, centrifugation, or cyclone.

  The compressive strength of the carrier material is preferably 1.0 MPa or more and less than 10 MPa, more preferably 1.0 MPa or more and less than 8.0 MPa, and still more preferably 2.0 MPa or more and less than 6.0 MPa. When the compressive strength is 1.0 MPa or more, the catalyst particles are crushed and reduced when the catalyst is synthesized or fed, and the resulting polymer particles tend to be prevented from scattering and adhering. When the compressive strength is less than 10 MPa, the carrier material is not crushed during the polymerization and the probability of remaining in the polyethylene is increased, and the problem that the smoothness of the cross-linked body surface is hindered tends to be suppressed.

  Further, the obtained supported metallocene catalyst may be washed by a method such as decantation or filtration using an inert solvent for the purpose of removing organoaluminum compounds, borate compounds, etc. not supported on the carrier. it can. In the case of producing the (a) ethylene polymer used in the present embodiment, it is preferable to carry out decantation and / or filtration twice or more in order to reduce low molecular weight components generated by side reactions. .

  Furthermore, the chlorine content in the catalyst is preferably 50 ppm by mass or less, more preferably 20 ppm by mass or less, still more preferably 5.0 ppm by mass or less, and the lower the content, the more preferable.

  The liquid promoter is a liquid promoter and a substance that increases the activity of the supported metallocene catalyst. Although it does not specifically limit as a liquid co-catalyst, For example, it can prepare from an organomagnesium compound and methyl hydropolysiloxane.

  Further, (a) the Ziegler-Natta catalyst used as a catalyst used in the method for producing an ethylene polymer is not particularly limited, but a compound containing a silane compound, organic magnesium, and titanium is prepared as a main raw material. be able to. More specifically, it can be prepared from trichlorosilane, organomagnesium, n-butyl alcohol, organoaluminum, and titanium tetrachloride.

  When preparing a Ziegler-Natta catalyst, when reacting a silane compound such as trichlorosilane with organomagnesium, the organomagnesium (eg, n-heptane solvent) is slowly added over 1 hour, preferably over 2 hours. It is preferable to add. Further, when adjusting the Ziegler-Natta catalyst, by-products and unreacted substances are mixed in the solvent after completion of the reaction, it is preferable to perform a washing operation three or more times after the reaction. Similarly, it is preferable to perform washing once or more after each reaction with an alcohol such as n-butyl alcohol, a compound containing titanium such as organic aluminum or titanium tetrachloride.

  The chlorine content in the solid catalyst is 70% or less, preferably 65% or less, and more preferably 60% or less.

  The polymerization method in the polymerization step is not particularly limited, and examples thereof include a slurry polymerization method, a gas phase polymerization method, and a solution polymerization method, and ethylene and α-olefin can be copolymerized by these polymerization methods. Among these, the slurry polymerization method that can efficiently remove the heat of polymerization is preferable. In the slurry polymerization method, an inert hydrocarbon medium can be used as the polymerization medium, and the olefin itself can also be used as the polymerization medium.

  The inert hydrocarbon medium is not particularly limited, but examples thereof include aliphatic hydrocarbons such as propane, butane, isobutane, pentane, isopentane, hexane, heptane, octane, decane, dodecane, and kerosene; cyclopentane, cyclohexane, methylcyclo Examples thereof include alicyclic hydrocarbons such as pentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethyl chloride, chlorobenzene and dichloromethane, and mixtures thereof.

  In the polymerization step, among the above-described inert hydrocarbon media, it is more preferable to use a hydrocarbon media having 6 to 10 carbon atoms. When the number of carbon atoms is 6 or more, a low molecular weight component that reacts with a crosslinking agent to lower pressure resistance and durability is relatively easily dissolved, and (a) in the step of separating the ethylene polymer and the polymerization medium ( a) It tends to be easily removed from the ethylene-based polymer. When the number of carbon atoms is 10 or less, (a) low molecular weight components (medium) remaining in the ethylene polymer are reduced, and adhesion of (a) ethylene polymer powder to the reaction vessel is suppressed. Therefore, industrially stable operation tends to be possible.

The polymerization temperature in the polymerization step is preferably 30 ° C. or higher and 100 ° C. or lower, more preferably 35 ° C. or higher and 95 ° C. or lower, and further preferably 40 ° C. or higher and 90 ° C. or lower. If the polymerization temperature is 30 ° C. or higher, industrially efficient production tends to be possible. On the other hand, when the polymerization temperature is 100 ° C. or lower, the stable operation tends to be continuously possible. From the viewpoint that a suitably predetermined range the sum of the composition fraction beta ₃₀ component (gamma) Composition fraction gamma ₃₀ and components (beta), the polymerization temperature is preferably 85 ° C. or less.

  The polymerization pressure in the polymerization step is preferably from normal pressure to 2 MPa, more preferably from 0.1 MPa to 1.5 MPa, and even more preferably from 0.1 MPa to 1.0 MPa.

  The polymerization in the polymerization step can be performed by any of batch, semi-continuous and continuous methods, and it is preferable to perform polymerization in a continuous manner. The continuous system supplies ethylene gas, solvent, catalyst, etc. continuously into the polymerization system, and continuously discharges it together with the generated (a) ethylene-based polymer, resulting in a partial high temperature due to rapid ethylene reaction. The state can be suppressed, and the inside of the polymerization system is further stabilized. When ethylene reacts in a uniform state in the system, it is possible to suppress the formation of branches, double bonds, and the like in the polymer chain. Thereby, (a) an ethylene-based polymer having high crosslinking efficiency is easily obtained, and the gel fraction tends to be increased. Therefore, a continuous system in which the inside of the polymerization system becomes more uniform is preferable.

  The polymerization step is preferably a step of polymerization by a two-stage polymerization method in which the polymerization is divided into two or more stages having different reaction conditions. The polymerization step is more preferably a step of polymerization by a slurry polymerization method and a two-stage polymerization method using a polymerization medium having 6 to 10 carbon atoms.

  (A) The molecular weight of the ethylene-based polymer is not particularly limited. For example, as described in the specification of German Patent Application Publication No. 3127133, hydrogen is allowed to exist in the polymerization system, and the polymerization temperature is changed. Can be adjusted by etc. It is also possible to control the molecular weight within an appropriate range by adding hydrogen as a chain transfer agent into the polymerization system. When hydrogen in the polymerization system is added, the molar fraction of hydrogen is preferably 0 mol% or more and 30 mol% or less, more preferably 0 mol% or more and 25 mol% or less, and 0 mol% or more and 20 mol% or less. Is more preferable.

  Furthermore, it is preferable that hydrogen is added to the polymerization system from the catalyst introduction line after contacting with the catalyst in advance. Immediately after the catalyst is introduced into the polymerization system, the concentration of the catalyst near the outlet of the introduction line is high, and there is an increased possibility of partial high temperatures due to the rapid reaction of ethylene. By bringing into contact before introduction, it is possible to suppress the initial activity of the catalyst, and it is possible to suppress the generation of low molecular weight components. Therefore, it is preferable to introduce hydrogen into the polymerization system in contact with the catalyst.

  After the polymerization step, wet nitrogen is preferably fed into the liquid to a flash tank for removing unreacted ethylene, comonomer, hydrogen and the like. By feeding wet nitrogen in the liquid, it is possible to suppress post-polymerization in flash tanks with different polymerization conditions (temperature, concentration, etc.), and reduce the production of low molecular weight components, low melting point polyethylene, etc. it can.

  (A) The solvent separation method in the method for producing an ethylene polymer can be carried out by a decantation method, a centrifugal separation method, a filter filtration method, or the like, but (a) a centrifugal separation method with good separation efficiency between the ethylene polymer and the solvent. Is more preferable. The amount of the solvent contained in the (a) ethylene polymer after the solvent separation is not particularly limited, but it is 70% by mass or less, more preferably based on the mass (100% by mass) of the (a) ethylene polymer. It is 60 mass% or less, More preferably, it is 50 mass% or less. (A) When the solvent contained in the ethylene polymer is removed in a small amount, the metal component or low molecular weight component contained in the solvent tends not to remain in the (a) ethylene polymer. It is in. When these components do not remain, (a) an ethylene polymer having excellent hygiene and high crosslinking efficiency is obtained, and a crosslinked product having excellent pressure resistance and durability is easily obtained. Therefore, it is preferable to separate (a) the ethylene polymer and the solvent by a centrifugal separation method.

(A) The drying temperature in the method for producing an ethylene polymer is preferably 50 ° C. or higher and 150 ° C. or lower, more preferably 50 ° C. or higher and 140 ° C. or lower, and further preferably 50 ° C. or higher and 130 ° C. or lower. When the drying temperature is 50 ° C. or higher, efficient drying tends to be possible. On the other hand, when the drying temperature is 150 ° C. or lower, (a) it tends to be possible to dry in a state where decomposition of the ethylene-based polymer is suppressed. From the viewpoint that a suitably predetermined range the sum of the composition fraction beta ₃₀ component (gamma) Composition fraction gamma ₃₀ and components (beta), the drying temperature is preferably 110 ° C. or less.

  (A) For pelletizing the ethylene polymer, it is preferable to use an extruder equipped with a 350 mesh screen. By using a 350 mesh screen, foreign matter and gel can be removed, the smoothness of the pipe surface tends to be improved, and a certain amount of extrusion can be ensured. In the present embodiment, in addition to the above production method, (a) other known methods useful for the production of an ethylene-based polymer can be included.

[[(B) Silanol condensation catalyst]]
The (b) silanol condensation catalyst used in the present embodiment is used to crosslink a silane compound grafted on polyethylene in the presence of water or water vapor when the molded body is crosslinked to produce a crosslinked body. In the ethylene resin composition, the content of the (b) silanol condensation catalyst is 0.05 parts by mass or more and 5.0 parts by mass or less, and preferably 0.1 parts by mass with respect to 100 parts by mass of the (a) ethylene polymer. It is not less than 3.0 parts by mass and more preferably not less than 0.3 parts by mass and not more than 2.0 parts by mass. (B) By setting the content of the silanol condensation catalyst to 0.05 parts by mass or more, the crosslinking reaction can be sufficiently advanced, and by setting the content to 5.0 parts by mass or less, the inside of the extruder during extrusion Therefore, it is possible to prevent the appearance from deteriorating due to local progress of crosslinking.

  (B) Silanol condensation catalyst is not particularly limited, but dibutyltin dilaurate, dibutyltin dioctoate, dibutyltin acetate, dibutyltin diacetate, dibutyltin maleate, dibutyltin phthalate, dibutyltin bis (2-ethylhexa Noe), dibutyltin bis (one decyl maleate), dibutyltin bis (benzyl malee), dibutyltin dimethoxide, dibutyltin bis (nonylphenoxide), dibutyltin oxide, dibutyltin bis (acetylacetonate) , Dibutyltin bis (ethylacetate), reaction product of dibutyltin oxide and silicate compound, reaction product of dibutyltin oxide and phthalate ester, tributyltin dilaurate (TBTDL), dioctyltin diacetate, dioctyl tin Laurate, dioctyl tin-bis (isooctyl maleate), dioctyl tin-bis (isooctyl thioglycolate), dioctyl tin maleate, dioctyl tin bis (ethyl maleate), dioctyl tin dineodecanoate, dioctyl tin oxide, Stannous acetate, stannous octoate, tin naphthenate, tin (II) stearate, tin (II) octate, tin dineodecanoate, stannous cabrylate, tin bisneodecanoate, bis (2-ethylhexanoic acid) ) Tin, tin (II) 2,4 pentadionate, acetylacetonate tin (II) and the like. (B) Preferred compounds include dibutyltin dilaurate and dioctyltin dilaurate. More preferred compounds include dioctyltin dilaurate.

〔〔Antioxidant〕〕
The ethylene-based resin composition of the present embodiment can contain (c) a phenol-based antioxidant and / or (d) a phosphorus-based antioxidant. (C) By containing a phenolic antioxidant and / or (d) a phosphorus antioxidant, it is possible to suppress deterioration of the resin after molding and during processing, and the resin deteriorates during and after molding. And long-term durability can be prevented from decreasing. The ethylene resin composition preferably contains at least one kind of (c) a phenolic antioxidant and (d) a phosphorus antioxidant.

  (C) Although it does not specifically limit as a phenolic antioxidant, For example, dibutylhydroxytoluene, pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl -3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate and the like.

  (C) Although content of a phenolic antioxidant is not specifically limited, 1.0 mass part or more and 30.0 mass parts or less are preferable with respect to an ethylene-type resin composition, More preferably, it is 5.0 mass parts. The amount is 20.0 parts by mass or less.

  (D) Phosphorus antioxidants include tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene-di-phosphonite, tris (2,4-di-t-butylphenyl) phos Phyto, cyclic neopentanetetrayl bis (2,4-t-butylphenyl phosphite) and the like.

  (D) Although content of phosphorus antioxidant is not specifically limited, 0.1 mass part or more and 5.0 mass part or less are preferable with respect to an ethylene-type resin composition, More preferably, it is 0.5 mass part. It is 3.0 parts by mass or more.

  In this embodiment, when (c) a phenolic antioxidant and (d) a phosphorus antioxidant are mixed in an ethylene resin composition, (a) an ethylene polymer and (b) a silanol condensation When the catalyst is melt-kneaded, it is preferable to melt-knead an antioxidant, particularly (c) a phenol-based antioxidant and (d) a phosphorus-based antioxidant. (A) If these antioxidants are contained in the ethylene polymer (if (a) the polymer contained in the polymer is used as the ethylene polymer), the crosslinked product may be yellowed. It is. In this embodiment, when (c) a phenol-based antioxidant and (d) a phosphorus-based antioxidant are mixed in a molded body or a crosslinked body described later, (c) a phenol-based antioxidant, (d ) It is preferable that the phosphorus-based antioxidant is contained in the ethylene-based resin composition and not contained in the silane-grafted polyethylene described later before mixing the ethylene-based resin composition.

[[Method for producing ethylene-based resin composition]]
The ethylene resin composition of the present embodiment is not particularly limited. For example, (a) an ethylene polymer, (b) a silanol condensation catalyst, any (c) a phenolic antioxidant, (d) It can be produced by melt-kneading a phosphorus-based antioxidant or the like with an extruder. During the melt-kneading, the resin temperature is not particularly limited and is preferably 180 ° C to 240 ° C.

〔Master Badge〕
The master batch of this embodiment consists of said ethylene-type resin composition. By using the ethylene resin composition as a master batch for producing a crosslinked product, a molded product and a crosslinked product can be produced with high production efficiency and high quality.

[Molded body]
The molded product of the present embodiment can be obtained using the above-described ethylene-based resin composition or masterbatch. Thereby, the molded object and crosslinked body of this embodiment can be produced with high production efficiency and high quality.

  Although it does not specifically limit as a manufacturing method of the molded object of this embodiment, For example, (1) Other component (silane graft | grafting) which contains said ethylene-type resin composition or masterbatch, and a silane grafting agent. A method of manufacturing by melt-kneading together and then forming into a desired shape, or (2) obtaining a silane-grafted polyethylene by previously grafting an ethylene-based polymer to a silane, Examples thereof include a method in which the above-described ethylene-based resin composition or masterbatch is melt-kneaded with a silane-grafted polyethylene obtained in advance and then formed into a desired shape.

  Specifically, in the production method of the above (1), an ethylene polymer, an organic peroxide and an organic unsaturated silane compound as a silane grafting agent, and the ethylene resin composition or master batch described above are extruders. And then kneaded into a desired shape. In this method, the ethylene-based resin composition or the master batch is kneaded with the respective components at once with an extruder, so that the respective components are appropriately and uniformly dispersed. Therefore, by using this at the time of pipe forming, each raw material component can be uniformly dispersed in the pipe by one kneading, so that a crosslinked product can be produced with high production efficiency and high quality. In the production method (1), the silane graft agent and the ethylene resin composition can be melt-kneaded with an ethylene polymer in an extruder, but without the ethylene polymer, The ethylene resin composition can also be melt-kneaded with an extruder.

  In the production method of (2), an ethylene polymer, and an organic peroxide and an organic unsaturated silane compound as a silane grafting agent are first melt-kneaded with an extruder to form a silane-grafted polyethylene, Next, the silane-grafted polyethylene and the above-described ethylene-based resin composition or masterbatch are melt-kneaded and then molded into a desired shape. In this method, the silane-grafted polyethylene is first formed, and then kneaded with the ethylene resin composition or masterbatch described above, so that it can be produced under more flexible melt-kneading conditions than the production method of (1). can do. In the production method of (2), more specifically, after the silane-grafted polyethylene is taken out from the extruder, the taken-out silane-grafted polyethylene and the ethylene resin composition or masterbatch are extruded. A method of melt-kneading in a machine, or forming the silane-grafted polyethylene in an extruder, and removing the formed silane-grafted polyethylene from the extruder, for example, from the feed port in the middle of the cylinder A method of charging and melting and kneading a resin composition or a master batch can be used.

  When melt kneading each component, the resin temperature is not particularly limited and is preferably 170 ° C to 240 ° C.

  The content of the ethylene resin composition in the molded body of the present embodiment is desirably 2% by mass or more and 7% by mass or less with respect to the molded body. If the content is less than 2% by mass, the crosslinking reaction described later will not proceed sufficiently, and if the content is more than 7% by mass, the crosslinking reaction may occur rapidly during melt-kneading. For example, the appearance of the molded body is deteriorated.

  The ethylene-based polymer that can be used in the production of the molded body of the present embodiment is not particularly limited, but (a) the same resin as the ethylene-based polymer in the ethylene-based resin composition is used. Can do.

  The organic peroxide of the silane grafting agent that can be used in the production of the molded article of this embodiment is not particularly limited, but dicumyl peroxide, 2,5-dimethyl-2,5-di- ( t-butyl-oxy) -hexyne-3,1,3-bis- (t-butyl-oxy-isopropyl) -benzene, t-butylcumyl peroxide, 4,4, -di- (t-butylperoxy) Valeric acid-butyl ester, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexanexin-3, benzoyl peroxide, dicyclobenzoperoxide, di-tert-butyl peroxide, Examples include lauroyl peroxide, di-t-butylperoxyisophthalate, and compounds having a double bond group and a peroxide group in the molecule. Of these, dicumyl peroxide, 2,5-dimethyl-2,5-di- (t-butyl-oxy) -hexyne-3 is preferable.

  The content of the organic peroxide of the silane grafting agent that can be used in the production of the molded product of the present embodiment is not particularly limited, but is 0.01% by mass or more and 0.5% by mass or less with respect to the molded product. Preferably, it is 0.05 mass% or more and 0.3 mass% or less.

  The organounsaturated silane compound of the silane grafting agent that can be used in the production of the molded article of the present embodiment is not particularly limited, and examples thereof include vinyltrimethyoxysilane, vinyltriethoxysilane, vinyltributoxysilane, Examples include allyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyltris (β-methoxyethoxy) silane.

  The content of the organounsaturated silane compound of the silane grafting agent that can be used in the production of the molded product of the present embodiment is not particularly limited, but is preferably 1% by mass or more and 20% by mass or less with respect to the molded product. Preferably they are 1 mass% or more and 10 mass% or less.

  The molded body of this embodiment may further contain various additives such as a neutralizing agent, a processing stabilizer, a metal deactivator, and a light resistance stabilizer. The additive may be added during the production of the molded article, or may be contained during the production of the ethylene resin composition and the silane-grafted polyethylene.

  The neutralizing agent is used as a catcher for chlorine components contained in the molded body, a molding processing aid, and the like. Although it does not specifically limit as a neutralizing agent, For example, the stearates of alkaline-earth metals, such as calcium, magnesium, barium, are mentioned. The content of the neutralizing agent is not particularly limited, but is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and still more preferably 0.3% by mass or less with respect to the molded body. is there. The polyethylene polymer obtained by the slurry polymerization method using a metallocene catalyst can exclude a halogen component from catalyst components, and in this case, the molded product may not contain a neutralizing agent. preferable.

  The light-resistant stabilizer is not particularly limited, and examples thereof include 2- (5-methyl-2-hydroxyphenyl) benzotriazole and 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chloro. Benzotriazole-based light stabilizers such as benzotriazole; bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) amino- 1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4- Hindered amine light stabilizers such as piperidyl) imino}]. The content of the light-resistant stabilizer is not particularly limited, but is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and further preferably 0.3% by mass or less with respect to the molded body. is there.

  In addition to the above, the molded article of the present embodiment includes known phenolic stabilizers, organic phosphite stabilizers, organic thioether stabilizers, stabilizers such as metal salts of higher fatty acids: pigments, weathering agents, dyes, Lubricating agents such as nucleating agents and calcium stearate; inorganic fillers such as carbon black, talc and glass fibers or reinforcing materials, flame retardants, compounding agents added to polyolefins such as neutron blocking agents, do not impair the purpose of the present invention It can be added in a range. In addition, when an unreacted organic unsaturated silane compound, silanol condensation catalyst, and organic peroxide are present in the crosslinked product, an adsorbent such as activated carbon may be added in order to suppress elution thereof.

[Crosslinked product]
The crosslinked body of this embodiment is obtained by advancing a crosslinking reaction in the above molded body. Specifically, the crosslinked product is obtained by exposing the molded product to warm water, water vapor or the like to crosslink the silyl group in the molded product.

  The cross-linked product of this embodiment preferably has a gel fraction of 30% or more, more preferably 50% or more, and even more preferably 65% or more. The gel fraction is not particularly limited, but the gel fraction can be made high by uniformly grafting the organic unsaturated silane compound in the crosslinked body and further uniformly crosslinking the silane group with a silanol condensation catalyst. . In general, a crosslinked product having a high gel fraction has excellent mechanical strength such as short-term and long-term hot internal pressure creep. In the conventional crosslinked body, in order to obtain a high gel fraction, it is necessary to use a large amount of an organic unsaturated silane compound at the time of preparing the silane-grafted polyethylene. Moreover, even with a conventional crosslinked body, even if a high gel fraction is achieved, the hot internal pressure creep property is not satisfactory. On the other hand, since the crosslinked product of the present embodiment uses the above-mentioned ethylene resin composition or master batch, a high gel fraction can be obtained even with a small amount of an organic unsaturated silane compound added, and sufficient pressure resistance is obtained. And the durability tends to be achieved.

Here, the gel fraction is a value measured according to the estimation of the degree of cross-linking by measurement of JIS K 6696-1998 cross-linked polyethylene (PE-X) pipe and joint-gel content. Next, the measuring method of the gel fraction of a crosslinked body is demonstrated. Samples were cut from 0.5 g to 1.0 g from the cross-linked product, extracted in a flask using xylene solvent for 8 hours, dried residue was extracted, and the mass of the residue was measured. Obtained by the formula.
G = (mass of residue after extraction) / (mass of sample before extraction) × 100
G: Gel fraction

  In the crosslinked body of this embodiment, the oxidation induction time is preferably 40 minutes or more, more preferably 45 minutes or more. By setting the oxidation induction time to 40 or more, the crosslinked body can have excellent thermal stability and oxidation resistance. The oxidation induction time can be measured by the method described in Examples described later.

[Use]
The ethylene-based resin composition, master batch, molded product, and crosslinked product of the present embodiment are not particularly limited, but are coated with tubular materials such as pipes, hoses and tubes, coating materials used for conductors such as electric wires and cables, various containers, and sealing. It can be used for various applications such as materials, films, porous films, and sheets. The ethylene-based resin composition, master batch, molded body and crosslinked body are preferably for a tubular body, and more preferably for a pipe. The shape of the crosslinked body for these uses is not particularly limited, but it may be formed into a desired shape in the molded body before forming the crosslinked body, or may be formed into a desired shape after forming the crosslinked body. You may shape | mold (for example, cutting etc.).

  Hereinafter, the present embodiment will be described in more detail based on examples, but the present embodiment is not limited to the following examples. First, the physical properties and measurement methods for evaluation and evaluation criteria will be described below.

(Physical property 1: weight average molecular weight and number average molecular weight of ethylene resin composition and ethylene polymer, and ratio thereof)
A sample solution was prepared by introducing 15 mL of o-dichlorobenzene into 20 mg of the sample (ethylene-based resin composition or ethylene-based polymer) obtained in Examples and Comparative Examples and stirring at 150 ° C. for 1 hour. Permeation chromatography (GPC) was measured. From the measurement results, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the ratio (Mw / Mn) of the sample are calculated based on a calibration curve (primary approximation) created using commercially available monodisperse polystyrene. Asked. The materials and conditions used for the measurement were as follows. The results obtained from the samples of each Example and Comparative Example are shown in Tables 1 and 2.

Apparatus: 150-C ALC / GPC manufactured by Waters
Detector: RI detector Mobile phase: o-dichlorobenzene (for high performance liquid chromatograph)
Flow rate: 1.0 mL / min Column: What connected one AT-807S by Showa Denko KK and two TSK-gelGMH-H6 by Tosoh KK was used.
Column temperature: 140 ° C

(Physical property 2: MFR of ethylene polymer)
About each ethylene polymer obtained by the Example and the comparative example, melt flow rate (MFR) was measured by JISK7210 code | cord | dies D: 1999 (temperature = 190 degreeC, load = 2.16kg). Tables 1 and 2 show the results obtained from the ethylene polymers of the examples and comparative examples.

(Physical property 3: Density of ethylene polymer)
About each ethylene polymer obtained by the Example and the comparative example, the density was measured by JIS K7112: 1999 and a density gradient tube method (23 degreeC). Tables 1 and 2 show the results obtained from the ethylene polymers of the examples and comparative examples.

(Physical property 4: Pulsed NMR of ethylene resin composition)
For each ethylene-based resin composition obtained in the examples and comparative examples, the component having the lowest motility when approximating the three components of the free induction decay curve measured at 30 ° C. by the solid NMR method of pulsed NMR The composition ratio α, β, γ of the component (γ) having the highest motility, the intermediate motility component (β), and the relaxation time T _γ of the component (γ) were measured under the following conditions. The results obtained from the ethylene resin compositions of the examples and comparative examples are shown in Tables 1 and 2.
Measuring device: JNM-Mu25 manufactured by JEOL Ltd.
Observation nucleus: ¹ H
Measurement: Spin-spin relaxation Measurement method: Solid echo method Pulse width: 2.2 to 2.3 μs
Pulse interval: 7.0 μs to 9.2 μs
Number of integrations: 128 times Measurement temperature: 30 ° C. (Measurement started 5 minutes after reaching the measurement temperature.)
Repeat time: 3 sec
Analysis method: Using the following (Equation 1), fitting was performed with analysis software to approximate three components.
M (t) = αexp (− (1/2) (t / T _α ) ² ) sinbt / bt + βexp (− (1 / Wa) (t / T _β ) ^Wa ) + γexp (−t / T _γ ). (Formula 1)
α: Composition ratio of α component T _α : Relaxation time of α component (unit: msec)
β: Composition ratio of β component T _β : Relaxation time of β component (unit: msec)
γ: Composition fraction of γ component T _γ : Relaxation time of γ component (unit: msec)
t: Observation time (unit: msec)
Wa: Shape factor b: Shape factor

(Evaluation 1: Smoke amount during processing)
When each of the ethylene resin compositions of Examples and Comparative Examples and the silane-grafted polyethylene of Example 1 were used to produce molded bodies by the method of producing a molded body of Example 1, melt kneading in an extruder was used. Occasionally, the amount of smoke generated in the extruder die was visually checked and evaluated. The results obtained from the ethylene resin compositions of the examples and comparative examples are shown in Tables 1 and 2.
○: Smoke is observed.
Δ: Smoke is occasionally generated, but the amount of smoke is small throughout.
×: Smoke generation is always observed.

(Evaluation 2: Appearance of molded body)
The crosslinked bodies obtained in the examples and comparative examples were visually confirmed, and the appearance of the molded bodies was evaluated according to the following criteria. Tables 1 and 2 show the results obtained from the crosslinked products of the examples and comparative examples.
○: Good when there are no irregularities due to gel or the like on the outer surface of the molded body.
Δ: When there are irregularities due to gel-like materials on the outer surface of the molded body, but only a small part of the surface of the molded body has a slight effect on the overall appearance.
X: When there are many unevenness | corrugations by a gel-like thing etc. on the outer surface in a molding.

(Evaluation 3: Molded body color)
The color of the molded products obtained in Examples and Comparative Examples was visually confirmed, and compared with the color (white) of the raw ethylene polymer, and evaluated. Tables 1 and 2 show the results obtained from the molded articles of each Example and Comparative Example.
○: Equivalent to the color of ethylene polymer. (white)
(Triangle | delta): Some discoloration is seen compared with the color of an ethylene-type polymer. (White to light beige)
X: Discoloration is observed as compared with the color of the ethylene polymer. (Beige to yellow)

(Evaluation 4: Gel fraction of crosslinked product)
The gel fraction of each crosslinked product obtained in the Examples and Comparative Examples is as follows according to the JIS K 6787-1997 Crosslinked Polyethylene Pipe for Water Supply Annex 7 (normative): Measured by the method. Tables 1 and 2 show the results obtained from the crosslinked products of the examples and comparative examples.

Next, a specific method for measuring the gel fraction of the crosslinked body will be described.
(I) An aluminum or stainless steel cage having a mesh with a hole diameter of 125 μm ± 25 μm is prepared. (The weight of the car is “m1”.)
(Ii) 0.5 g to 1.0 g of a sample sliced or scraped to a thickness of 0.1 mm to 0.2 mm is weighed and placed in the basket. (The weight of the basket including the sample is “m2”.)
(Iii) Place the basket containing the sample in the flask and add a sufficient amount of xylene that can be reliably immersed, and then vigorously boil the solvent for 8 hours ± 5 minutes.
(Iv) Carefully remove the sample residue and the basket from the boiling solvent and wipe the outside of the basket with a cloth.
(V) The remaining basket is completely dried for 3 hours by either of the following methods a) and b).
a) In a vacuum furnace at 140 ° C. ± 2 ° C. and at a negative pressure of at least 0.85 Bar (85 KPa) (ie, absolute pressure of about 0.15 bar or less).
b) At 140 ° C ± 2 ° C in a forced ventilation oven with appropriate exhaust.
(Vi) Cool well and remove residue from the basket. (The weight of the basket including the residue is “m3”.)
(Vii) Calculate the degree of crosslinking for each sample as a percentage of the mass of insoluble matter; G1 according to the following formula:
(Viii) G1 = (m3−m1) / (m2−m1) × 100
Results are expressed as the closest integer.
(Ix) The above operations (i) to (vii) are repeated at least once with a new sample.
(X) The average degree of cross-linking G is calculated from each result. If there is a difference of 3 points or more between two individual results, repeat the test with two new samples again.

(Evaluation 5: Oxidation induction time)
The oxidation induction time (OIP) of each crosslinked product obtained in Examples and Comparative Examples is measured using DSC. DSC-60 Plus (manufactured by Shimadzu Corporation) was used for the measurement. First, 5 mg of aluminum oxide was put into an aluminum pan for DSC measurement. This was set on the left side of the DSC-60Plus furnace, and on the right side of the furnace, an aluminum pan containing 5 mg of a cross-linked sample for measurement was set. The inner lid was closed, the protective cover was lowered, the temperature was raised to 240 ° C. while flowing nitrogen gas at 25 mL / min in the furnace, and the measurement was started after standing for 1 minute in that state. The heating rate was 25 ° C./min. The sampling interval during measurement was set to 0.5 seconds. After 1 minute, the nitrogen was switched to oxygen to oxidize the sample. It passes through a point on the chart when nitrogen is switched to oxygen, a straight line with the slope of the chart at that point, the chart rises, passes through the inflection point before passing the first peak, and at that inflection point OIP was measured by calculating the time of intersection with a straight line having the slope of the chart. Tables 1 and 2 show the results obtained from the crosslinked products of the examples and comparative examples.

  OIP is closely related to the thermal stability and oxidation resistance of the sample, and the longer the OIP, the better the thermal stability and oxidation resistance.

(Adjustment of polymerization catalyst)
A metallocene supported catalyst [A], a Ziegler-Natta catalyst [H], and a liquid promoter [B] that can be used with them were prepared by the following method.

[Metalocene-supported catalyst [A]]
The metallocene supported catalyst [A] was obtained through the adjustment of the following carrier [C], transition metal compound [D], and activator [E].
(Preparation of carrier [C])
The spherical silica (40 g) after heat treatment was dispersed in 800 mL of hexane in a 1.8 L autoclave purged with nitrogen to obtain a slurry. While maintaining the resulting slurry at 20 ° C. with stirring, 80 mL of a hexane solution of triethylaluminum (concentration 1M) was added, and then stirred for 2 hours to prepare 880 mL of a hexane slurry of carrier [C] adsorbing triethylaluminum.

(Preparation of transition metal compound [D])
As the transition metal compound (D-1), [(Nt-butylamide) (tetramethyl-η5-cyclopentadienyl) dimethylsilane] titanium-1,3-pentadiene (hereinafter abbreviated as “titanium complex”) Prepared. Furthermore, a composition formula AlMg ₆ (C ₂ H ₅ ) ₃ (C ₄ H ₉ ) ₁₂ (hereinafter abbreviated as “Mg1”) was prepared as the organomagnesium compound (D-2). In addition, Mg1 as an organomagnesium compound (D-2) was synthesized by mixing a predetermined amount of triethylaluminum and dibutylmagnesium at 25 ° C. in hexane. 200 mmol of titanium complex as transition metal compound (D-1) is dissolved in 1000 mL of Isopar (registered trademark) E (manufactured by ExxonMobil Chemical), and then hexane solution of Mg1 as organomagnesium compound (D-2) in the solution. 20 mL of (concentration 1M) was added, and hexane was further added to the solution to adjust the titanium complex concentration in the solution to 0.1 M, thereby obtaining a transition metal compound [D].

(Preparation of activator [E])
As the activating compound (E-1), bis (hydrogenated tallow alkyl) methylammonium-tris (pentafluorophenyl) (4-hydroxyphenyl) borate (hereinafter abbreviated as “borate”) was prepared. Further, ethoxydiethylaluminum was prepared as the activating compound (E-2). 5.7 g of borate as the activating compound (E-1) was added and dissolved in 50 mL of toluene to obtain a 100 mM toluene solution of borate. To this toluene solution of borate, 5 mL of a hexane solution of ethoxydiethylaluminum (concentration 1M) was added at 25 ° C., and further hexane was added to adjust the borate concentration in the toluene solution to 80 mM. Then, activator [E] was prepared by stirring at 25 degreeC for 1 hour.

(Preparation of metallocene supported catalyst [A])
50 mL of the activator [E] obtained by the above operation was added to 880 mL of the slurry of the support [C] obtained by the above operation with stirring at 20 ° C., and the reaction was continued for 10 minutes. Next, 40 mL of the transition metal compound component [D] obtained by the above operation was added with stirring, and the reaction was continued for 3 hours to obtain a slurry. Further, the supernatant of this slurry was removed, and a purification operation in which hexane was added and stirred was carried out three times, and a metallocene supported catalyst [A] having a chlorine content of 1 mass ppm or less (in Table 1, simply [A ] Was prepared.

[Ziegler-Natta catalyst [H]]
2740 mL of trichlorosilane (HSiCl ₃ ) as a 2 mol / L n-heptane solution was charged into a 15 L reactor sufficiently purged with nitrogen, maintained at 50 ° C. with stirring, and the composition formula AlMg ₆ (C ₂ H ₅ ) ₃ (N-C ₄ H ₉ ) _10.8 (On-C ₄ H ₉ ) 7 L of an n-heptane solution of an organomagnesium component represented by _1.2 (5 mol in terms of magnesium) is added over 3 hours, and further 50 ° C. For 1 hour with stirring. After completion of the reaction, the supernatant was removed from the reaction solution containing the solid, and the resulting solid was washed 4 times with 7 L of n-hexane to obtain a slurry. As a result of separating, drying and analyzing this solid, it contained Mg 8.62 mmol, Cl 17.1 mmol, and n-butoxy group (On-C ₄ H ₉ ) 0.84 mmol per gram of the solid.

  The slurry containing 500 g of the solid obtained as described above was reacted with 1250 mL of n-butyl alcohol 1 mol / L n-hexane solution at 50 ° C. for 1 hour with stirring. After completion of the reaction, the supernatant was removed from the reaction solution containing the solid, and the resulting solid was washed once with 7 L of n-hexane to obtain a slurry. The slurry was kept at 50 ° C., and 500 mL of an n-hexane solution of 1 mol / L of diethylaluminum chloride was added with stirring and reacted for 1 hour. After completion of the reaction, the supernatant was removed from the reaction solution containing the solid, and the resulting solid was washed twice with 7 L of n-hexane to obtain a slurry. This slurry was kept at 50 ° C., 78 mL of n-hexane solution of 1 mol / L of diethylaluminum chloride and 78 mL of n-hexane solution of 1 mol / L of titanium tetrachloride were added and reacted for 1 hour. Furthermore, 234 mL of n-hexane solution of 1 mol / L of diethylaluminum chloride and 234 mL of n-hexane solution of 1 mol / L of titanium tetrachloride were added to this reaction solution, and reacted for 2 hours. After completion of the reaction, the supernatant was removed from the reaction solution containing the solid, and the inner temperature was kept at 50 ° C., followed by washing 4 times with 7 L of n-hexane, and the solid catalyst Ziegler-Natta catalyst [H] ( In Table 1, simply indicated as [H]) was obtained as a hexane slurry solution. The chlorine content of this solid catalyst was 55% by mass.

[Liquid cocatalyst [B]]
The Mg1 was prepared as the organomagnesium compound [G]. As compound [J], methylhydropolysiloxane (viscosity at 25 ° C., 20 centistokes, manufactured by Shin-Etsu Silicon Co., Ltd.) was used. To a 200 mL flask, 40 mL of hexane and Mg1 were added with stirring so that the total amount of Mg and Al was 37.8 mmol, and 40 mL of hexane containing 2.27 g (37.8 mmol) of methylhydropolysiloxane at 25 ° C. Was added with stirring, and then the temperature was raised to 80 ° C., and the reaction was allowed to proceed with stirring for 3 hours to prepare a liquid promoter component [B].

[Example 1]
(Method for producing ethylene polymer)
Using a Bessel type 340L polymerization reactor equipped with a stirrer, continuous polymerization was carried out under conditions of a polymerization temperature of 80 ° C., a polymerization pressure of 1 MPa, and an average residence time of 2.5 hours. Dehydrated normal hexane 65 L / hour as a solvent, 50 mg / hour of the supported metallocene catalyst [A] as a catalyst, 4 mmol / hour of liquid promoter [B] in terms of Al atom, Polymerization was carried out by supplying 0.25 mol% of butene and 0.37 mol% of hydrogen. Hydrogen was reacted with the supported metallocene catalyst [A] and then introduced into the reactor. The polymerization slurry in the polymerization reactor was led to a flash tank having a pressure of 0.04 MPa and a temperature of 70 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene, 1-butene and hydrogen were separated.

  Subsequently, the polymerization slurry in the polymerization reactor was continuously sent to a centrifuge to separate the polymer from the other solvent and obtain polyethylene powder. Content of the solvent etc. with respect to the polymer at that time was 45 mass%. The separated polyethylene powder was dried for 1.5 hours while blowing nitrogen at 85 ° C. After drying, it was further cooled for 1 minute in a stream of 50 ° C.

  The obtained polyethylene powder (powder of ethylene polymer) was added to a twin screw extruder (TEX-44 (screw diameter 44 mm, manufactured by Nippon Steel Works) without using additives such as neutralizing agents and antioxidants. , L / D = 35 L: distance (m) from the raw material supply port to the discharge port of the polymerization reactor, D: inner diameter (m) of the polymerization reactor, hereinafter, the twin-screw extruder is the Japan Steel Works, Ltd. Using TEX-44 manufactured at a temperature of 230 ° C. to obtain an ethylene-based polymer (pellet) having a 120 mesh, The screens were used in the order of 350 mesh and 120 mesh.

(Method for producing silane-grafted polyethylene)
As the silane-grafted polyethylene, the above ethylene polymer is used, and with respect to 100 parts by mass of the ethylene polymer, 5.0 parts by mass of vinyltrimethoxysilane and perhexa 25B (manufactured by NOF Corporation) 0 as an organic peroxide. .15 parts by mass was contained. Each component was mixed with Hensiel, and then a silane-grafted polyethylene was obtained by adjusting the resin temperature to about 200 ° C. and performing extrusion compounding and pelletizing using a twin screw extruder.

(Method for producing ethylene resin composition)
The ethylene-based resin composition uses the above-mentioned ethylene-based polymer, and (b) 1.7 parts by weight of dioctyltin dilaurate as a silanol condensation catalyst with respect to 100 parts by weight of the ethylene-based polymer, (c) phenol-based antioxidant 4.1 parts by mass of Irganox 1010 (manufactured by BASF) as the agent, 8.3 parts by mass of Irganox 1330 (manufactured by BASF), 4.9 parts by mass of Irganox 1076 (manufactured by BASF), (d) Irgafos 168 as the phosphorus-based heat stabilizer (Made by BASF) 2.5 mass parts was contained. Furthermore, 5.2 parts by mass of Irganox MD1024 (manufactured by BASF) and 4.3 parts by mass of Dynamer FX9613 (manufactured by 3M) were added as other additives. Each component was mixed with Hensiel, and then melt kneaded while adjusting the resin temperature to about 200 ° C. using a twin screw extruder. After melt-kneading, it was cooled with 40 ° C. water for 20 seconds and pelletized to obtain an ethylene-based resin composition. Of the ethylene-based polymers used, 15 parts by mass of powder (the ethylene-based polymer before the above pelletizing) was used, 85 parts by mass of pellets, and the powdered ethylene-based polymer and (c) phenol A system antioxidant, (d) a phosphorus-based heat stabilizer and other powdered additives were mixed in advance, and the remaining components and pelleted ethylene polymer were mixed with the premixed components.

(Method for producing molded body and crosslinked body)
The ethylene-based resin composition used as a master batch for the silane-grafted polyethylene is uniformly mixed using a Henschel mixer so that the mass becomes 5.0% by mass, and melt-kneaded with a pipe extruder. As a result, a tubular molded body having a nominal diameter of 13 mm was obtained. This molded body was immersed in warm water at 100 ° C. for 12 hours to obtain a tubular crosslinked body.

[Example 2]
(Method for producing ethylene polymer)
As the first stage polymerization, continuous polymerization was performed using a Bessel type 340L polymerization reactor equipped with a stirrer under conditions of a polymerization temperature of 80 ° C., a polymerization pressure of 0.95 MPa, and an average residence time of 2.5 hours. Dehydrated normal hexane 65 L / hour as a solvent, the above Ziegler-Natta catalyst [H] as a catalyst, 10.0 mg / hour, the liquid promoter [B] as an Al atom in terms of 10 mmol / hour, with respect to the ethylene gas phase concentration Each was supplied so that the hydrogen content would be 79.5 mol%, and the first stage polymerization was performed. The polymerization slurry in the polymerization reactor was led to a flash tank having a pressure of 0.4 MPa and a temperature of 70 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene and hydrogen were separated.

  Next, it is continuously transferred to a vessel type 300 L polymerization reactor equipped with a second-stage stirring device, and subjected to continuous polymerization under conditions of a polymerization temperature of 80 ° C., a polymerization pressure of 0.4 MPa, and an average residence time of 0.5 hours. went. The second-stage polymerization was carried out by supplying dehydrated normal hexane as a solvent at 190 L / hr, 1-butene 4 mol% and hydrogen 28 mol% with respect to the gas phase concentration of ethylene. The polymerization slurry in the polymerization reactor was continuously drawn into a flash drum at a pressure of 0.4 MPa and a temperature of 70 ° C. so that the level of the polymerization reactor was kept constant, and unreacted ethylene, 1-butene and hydrogen were removed. separated.

  In addition, about the process after isolation | separation of unreacted ethylene etc., it carried out similarly to Example 1, and obtained the powder and pellet of the ethylene-type polymer.

(Silane grafted polyethylene, ethylene-based resin composition, molded product, and method for producing crosslinked product)
In the same manner as in Example 1, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

Example 3
As a method for producing an ethylene-based polymer, a polymerization temperature of 85 ° C., a polymerization pressure of 1 MPa, an average residence time of 4 hours, a dehydrated normal hexane of 35 L / hour, a 10.0 mg / hour of the above Ziegler-Natta catalyst [H] as a catalyst, a liquid The co-catalyst [B] was polymerized at 10 mmol / hour in terms of Al atoms, 1-butene 0 mol% and hydrogen 46 mol% with respect to the gas phase concentration of ethylene, and placed in a flash tank at a pressure of 0.03 MPa and a temperature of 72 ° C. Except for the above, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product and a crosslinked product were obtained in the same manner as in Example 1.

Example 4
As a method for producing an ethylene polymer, 1960 ppm of (I) Irganox 1076 manufactured by BASF as a phenolic antioxidant was added to polyethylene powder obtained by drying, and melted and kneaded with a twin screw extruder. In the same manner as in Example 1, an ethylene polymer was obtained. As a method for producing an ethylene resin composition, an ethylene resin composition was obtained in the same manner as in Example 1 except that (c) Irganox 1076 as a phenolic antioxidant was not contained. Moreover, the silane grafted polyethylene, the molded product, and the crosslinked product were obtained by the same production method as in Example 1.

Example 5
As a method for producing an ethylene polymer, polymerization is performed at a polymerization temperature of 82 ° C., an average residence time of 5 hours, dehydrated normal hexane 25 L / hour, and 1-butene 0.25 mol% and hydrogen 25 mol% with respect to the gas phase concentration of ethylene. An ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained in the same manner as in Example 3 except that it was led to a flash tank having a pressure of 0.04 MPa and a temperature of 70 ° C.

Example 6
As a method for producing a molded article, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, and a molded article were the same as in Example 1 except that the ethylene resin composition was 1% by mass with respect to the molded article. And the crosslinked body was obtained.

Example 7
As the ethylene-based polymer of the ethylene-based resin composition, the ethylene-based polymer and the silane-grafted polyethylene were the same as in Example 1 except that 50 parts by mass of the ethylene-based polymer was powder and 50 parts by mass was pelleted. Then, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

Example 8
As the ethylene-based polymer of the ethylene-based resin composition, the ethylene-based polymer and the silane-grafted polyethylene were the same as in Example 1 except that 75 parts by mass of the ethylene polymer was powder and 25 parts by mass of pellets. Then, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

Example 9
As the ethylene polymer of the ethylene resin composition, 50 parts by mass of powder of the ethylene polymer, 50 parts by mass of pellets, and cooling after melting and kneading the ethylene resin composition with water at 95 ° C. In the same manner as in Example 1 except that the conditions were 5 minutes, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

Example 10
As the ethylene polymer of the ethylene resin composition, 75 parts by mass of powder of the ethylene polymer, 25 parts by mass of pellets, and cooling after melting and kneading the ethylene resin composition with water at 95 ° C. In the same manner as in Example 1 except that the conditions were 5 minutes, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

Example 11
As a method for producing an ethylene resin composition, (c) an ethylene polymer, a silane-grafted polyethylene, and an ethylene resin were used in the same manner as in Example 1 except that Irganox 1010, Irganox 1330, and Irganox 1076 as phenolic antioxidants were not used. A composition, a molded product and a crosslinked product were obtained.

Example 12
As the method for producing an ethylene resin composition, (d) an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, and a molded article are the same as in Example 1 except that Irgafos 168 is not used as the phosphorus heat stabilizer. And the crosslinked body was obtained.

[Comparative Example 1]
As the method for producing an ethylene resin composition, an ethylene polymer, a silane-grafted polyethylene, and an ethylene resin composition were used in the same manner as in Example 1 except that (b) 7 parts by mass of dioctyltin dilaurate as a silanol condensation catalyst was used. Articles, molded bodies and cross-linked bodies were obtained.

[Comparative Example 2]
As a method for producing an ethylene polymer, polymerization temperature 83 ° C., polymerization pressure 0.5 MPa, average residence time 5 hours, dehydrated normal hexane 32 L / hour, propylene 4 mol%, hydrogen 53.5 mol% with respect to ethylene gas phase concentration The ethylene-based polymer, the silane-grafted polyethylene, the ethylene-based resin composition, the molded product, and the molded product were obtained in the same manner as in Example 3 except that the resin composition was melt-kneaded and cooled with 95 ° C. water for 10 minutes. A crosslinked product was obtained.

[Comparative Example 3]
As an ethylene polymer production method, an average residence time is 4.3 hours, dehydrated normal hexane is 25 L / hour, polymerization is performed at 16.5 mol% of hydrogen with respect to a gas phase concentration of ethylene, a pressure of 0.06 MPa, and a temperature of 50 ° C. An ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained in the same manner as in Example 3 except that it was led to the flash tank.

[Comparative Example 4]
As an ethylene polymer of the ethylene resin composition, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained in the same manner as in Example 1 except that 100 parts by mass of pellets were used. Obtained.

[Comparative Example 5]
An ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, and a molded product in the same manner as in Example 1 except that the cooling after the melt-kneading of the ethylene resin composition was performed with water at 10 ° C. for 5 minutes. And the crosslinked body was obtained.

[Comparative Example 6]
Example 1 except that 100 parts by mass of the ethylene-based resin composition as an ethylene polymer was pelleted, and that the cooling after the melt-kneading of the ethylene-based resin composition was performed at 10 ° C. for 5 minutes. Similarly, an ethylene polymer, a silane-grafted polyethylene, an ethylene resin composition, a molded product, and a crosslinked product were obtained.

上記表によれば、実施例１〜１２では、エチレン系樹脂組成物が、（ａ）エチレン系重合体１００質量部と、（ｂ）シラノール縮合触媒０．０５質量部以上５．０質量部以下とを含有し、重量平均分子量が１００万以上の成分の合計が３．０％以下、重量平均分子量が１０００未満の成分の合計が４．５％以下であり、組成分率γ_３０と組成分率β_３０との合計が４０％以上であるので、比較例１〜６に比べて、加工時の発煙及びパイプ外観が向上しており、したがって、架橋体を高い生産効率で、高い品質で生産可能である。

According to the said table | surface, in Examples 1-12, ethylene-type resin composition is (a) 100 mass parts of ethylene polymers, and (b) 0.05 mass part or less of silanol condensation catalyst. The total of components having a weight average molecular weight of 1,000,000 or more is 3.0% or less, the total of components having a weight average molecular weight of less than 1000 is 4.5% or less, and the composition fraction γ ₃₀ and the composition Since the total with the rate β ₃₀ is 40% or more, compared with Comparative Examples 1 to 6, the smoke generation and the pipe appearance at the time of processing are improved, and thus the crosslinked body is produced with high production efficiency and high quality. Is possible.

  ADVANTAGE OF THE INVENTION According to this invention, the ethylene-type resin composition, masterbatch, and molded object which can produce a crosslinked body with high production efficiency and high quality can be provided. Moreover, according to this invention, the crosslinked body which has high quality can be provided.

Claims (11)

(A) 100 parts by mass of an ethylene polymer, and (b) 0.05 part by mass or more and 5.0 parts by mass or less of a silanol condensation catalyst,
In gel permeation chromatograph (GPC) measurement, the total of components having a weight average molecular weight of 1,000,000 or more is 3.0% or less, and the total of components having a weight average molecular weight of less than 1000 is 4.5% or less,
In the measurement by the solid echo method of pulsed NMR, when the free induction decay curve at 30 ° C. is approximated by three components, the composition fraction γ ₃₀ of the highest mobility component (γ) and the intermediate mobility component (β) Ethylene resin composition whose total with composition fraction (beta) ₃₀ is 40% or more. The (a) ethylene polymer has a melt flow rate of 0.1 g / 10 min to 10.0 g / 10 min, a density of 935 kg / m ^{3 to} 960 kg / m ³ , and a number average molecular weight Mn in GPC measurement. The ethylene-based resin composition according to claim 1, wherein the weight average molecular weight Mw (Mw / Mn) is 3.0 or more and 10.0 or less.   The ethylene resin composition according to claim 1 or 2, comprising (c) a phenolic antioxidant and (d) a phosphorus antioxidant.   The (a) ethylene polymer in which the contents of the (b) phenolic antioxidant and the (c) phosphorus antioxidant in the (a) ethylene polymer are each 20 ppm or less is used. The ethylene-based resin composition according to any one of claims 1 to 3. (C) contains a phenolic antioxidant and (d) a phosphorus antioxidant,
The said (a) ethylene polymer, the said (b) silanol condensation catalyst, the said (c) phenolic antioxidant, and the said (d) phosphorus antioxidant are melt-kneaded, The Claims 1-4 The ethylene resin composition in any one.   The GPC measurement of the said ethylene resin composition WHEREIN: The ethylene resin composition in any one of Claims 1-5 whose sum total of a component whose weight average molecular weight is less than 10,000 is 15.0% or more.   The ethylene resin composition according to any one of claims 1 to 6, wherein a component having a weight average molecular weight of 1,000,000 or more is 2.0% or less in GPC measurement of the ethylene resin composition. In the pulse NMR measurement of the ethylene-based resin composition, the sum of the composition fraction γ ₃₀ of the component (γ) and the composition fraction β ₃ of the component (β) is 45% or more. The ethylene-based resin composition according to any one of the above.   The masterbatch which consists of an ethylene-type resin composition in any one of Claims 1-8.   A molded product of a melt-kneaded product of the masterbatch according to claim 9 and silane-grafted polyethylene.   A cross-linked product of the molded product according to claim 10.