Method for producing melt-kneaded composition, and melt-kneaded composition

Abstract

A method for producing a melt-kneaded composition, the method comprising a step for melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger, the melt-kneading being performed at 300-380 DEG C, the melt-kneading being performed by injecting an inert gas into the inside of a melt-kneading mill, and the melt-kneaded composition being obtained by melting the 3-methyl-1-butene polymer and the alkyl radical scavenger. Or the melt kneading is performed by decompressing and degassing the inside of the melt kneading machine.

Description

Technical Field

[0001] The present invention relates to a method for producing a melt-kneaded composition containing a 3-methyl-1-butene polymer and to the melt-kneaded composition. Background Art

[0002] 3-methyl-1-butene polymers have a high melting point among thermoplastic polyolefin resins and are useful as heat-resistant polyolefins. However, 3-methyl-1-butene polymers have a high melting point and therefore must be melt-kneaded at high temperatures. Therefore, there is a problem that during melt-kneading, 3-methyl-1-butene polymers deteriorate (decompose) due to heat and oxidation, resulting in reduced physical properties such as reduced viscosity of the melt and reduced mechanical properties of the molded body.

[0003] Therefore, Patent Document 1 studies the combination of antioxidants in view of the fact that the effect of antioxidants is lost in a short time. Patent Document 2 studies the type and combination of antioxidants added in order to prevent oxidative degradation of 3-methyl-1-butene polymers during melt kneading.

[0004] On the other hand, in order to ensure the stability of polyolefin during thermoforming, alkyl radical scavengers are sometimes used. For example, Patent Document 3 describes a polyolefin composition, which contains polyolefin, hindered phenol compound, acrylate compound and phosphorus compound in order to ensure heat resistance during high-temperature processing when forming fibers, etc. In addition, Patent Document 4 describes the oxidation stabilization of polyolefin-based thermoplastic resins, which describes a composition containing thermoplastic resins, phenolic antioxidants, aromatic amines and / or N,N'-substituted oxamide antioxidants and lactone antioxidants.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 61-181844

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 06-100742

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 05-059227

[0010] Patent Document 4: International Publication No. 2002 / 31038 Summary of the invention

[0011] Problems to be solved by the invention

[0012] In order to prevent the 3-methyl-1-butene polymer from being thermally degraded during melt kneading, it is conceivable to shorten the melt kneading time as much as possible.

[0013] However, the required melt-kneading time varies depending on the melt-kneader, and the larger the melt-kneader, the longer the melt-kneading time tends to be. Therefore, not using a large melt-kneader in order to shorten the melt-kneading time is disadvantageous from the viewpoint of productivity.

[0014] Like this, be difficult to avoid 3-methyl-1-butene based polymer being exposed to high temperature for a long time practically.In addition, if it is the resin combination of poor thermal stability, then can't guarantee the reproducibility of the difference between the mixing device, be difficult to stably manufacture formed body.In addition, even if the melt mixing time is short, if repeatedly carry out the reuse (material reuse) of scrap, then the melt mixing time that accumulates lengthens is inevitable.

[0015] As described above, in order to prevent the thermal degradation of 3-methyl-1-butene-based polymers, studies have been conducted on the use of antioxidants, alkyl radical scavengers, and the like.

[0016] However, no research has been conducted on the stability of physical properties during melt kneading with respect to long-term heat in Patent Documents 1 and 2. In fact, the inventors have tested the methods described in Patent Documents 1 and 2, but the long-term heat stability of the composition containing the 3-methyl-1-butene polymer is insufficient.

[0017] In Patent Document 3, no research was conducted on the use of 3-methyl-1-butene polymers as polyolefins. The results of the experiments of the inventors and others showed that even by the method described in Patent Document 3, the composition containing 3-methyl-1-butene polymers could not obtain long-term thermal stability. In addition, in Patent Document 4, no research was conducted on the use of 3-methyl-1-butene polymers, and only the thermal stability at a temperature lower than the melting point of the 3-methyl-1-butene polymers was studied. Therefore, even by the method described in Patent Document 4, long-term thermal stability cannot be expected for the composition containing 3-methyl-1-butene polymers.

[0018] Therefore, the problem of the present invention is to provide a method for producing a melt-kneaded composition that can maintain the stability of physical properties even after long-term melt-kneading, and a melt-kneaded composition. More specifically, the problem of the present invention is to provide a method for producing a melt-kneaded composition that can maintain the stability of physical properties even after long-term melt-kneading, has good productivity, and can obtain a molded body with good mechanical properties, and a melt-kneaded composition.

[0019] Those skilled in the art can grasp other issues based on the disclosure of this specification.

[0020] Means for solving problems

[0021] As a result of intensive studies to solve the above-mentioned problems, the present inventors have come up with the following invention and found that the problems can be solved.

[0022] That is, the present invention is as follows.

[0023] [1] A method for producing a melt-kneading composition, comprising the step of melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger at 300 to 380° C. in a low-oxygen state compared to the atmosphere.

[0024] [2] The method for producing a melt-kneaded composition according to [1], further comprising the step of injecting an inert gas into the interior of a melt-kneader, wherein the melt-kneading is performed in the melt-kneader.

[0025] [3] The method for producing a melt-kneaded composition according to [1] or [2], further comprising a step of decompressing and degassing the interior of a melt-kneader, wherein the melt-kneading is performed in the melt-kneader.

[0026] [4] A method for producing a melt-kneading composition, comprising the steps of melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger,

[0027] The melt kneading is performed at 300 to 380° C., and

[0028] The melt-kneading is performed by injecting an inert gas into the interior of the melt-kneading machine, or by decompressing and degassing the interior of the melt-kneading machine.

[0029] [5] The method for producing a melt-kneaded composition according to any one of [1] to [4], wherein the melt-kneading is performed for 1 to 15 minutes.

[0030] [6] The method for producing a melt-kneaded composition according to any one of [1] to [5], wherein the 3-methyl-1-butene-based polymer is at least one selected from a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms.

[0031] [7] The method for producing a melt-kneaded composition according to [6], wherein the content of the structural unit derived from the α-olefin in the copolymer is more than 0 mol % and not more than 20 mol %.

[0032] [8] The method for producing a melt-kneaded composition according to any one of [1] to [7], wherein the alkyl radical scavenger comprises at least one selected from an acrylic phenol compound and a benzofuranone compound.

[0033] [9] The method for producing a melt-kneaded composition according to [8], wherein the acrylic phenol compound is represented by the following general formula (I).

[0034] [Chemical formula 1]

[0035]

[0036] (In the general formula (I), R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 3 , R 4 , R 5 and R 6 Each independently represents an alkyl group having 1 to 9 carbon atoms.

[0037]

[10] The method for producing a melt-kneaded composition according to [8] or [9], wherein the benzofuranone compound is represented by the following general formula (II).

[0038] [Chemical formula 2]

[0039]

[0040] (In the general formula (II), R 7 and R 8 Each independently represents an alkyl group having 1 to 4 carbon atoms, R 9 and R 10 Each independently represents an alkyl group having 1 to 9 carbon atoms.

[0041]

[11] The method for producing a melt-kneaded composition according to any one of [1] to

[10] , wherein the amount of the alkyl radical scavenger is 0.01 to 1.00 parts by mass per 100 parts by mass of the 3-methyl-1-butene polymer.

[0042]

[12] A method for producing a melt-kneaded composition according to any one of [1] to

[11] , wherein in the melt-kneading step, at least one antioxidant selected from a phenolic antioxidant and a phosphorus antioxidant is further added to carry out the melt-kneading.

[0043]

[13] A melt-kneaded composition produced by the method for producing a melt-kneaded composition according to any one of [1] to

[12] .

[0044] Effects of the Invention

[0045] According to the present invention, there can be provided a method for producing a melt-kneaded composition which can maintain the stability of physical properties even after long-term melt-kneading, has good productivity, and can obtain a molded body having good mechanical properties, and a melt-kneaded composition. DETAILED DESCRIPTION

[0046] Hereinafter, an example of an embodiment of the present invention will be described. However, the embodiment described below is an example for embodying the technical idea of ​​the present invention, and the present invention is not limited to the following description.

[0047] In addition, in this specification, preferred modes of the embodiments are shown, but the mode formed by combining two or more preferred modes is also a preferred mode. Regarding the matters shown in the numerical range, when there are several numerical ranges, their lower limits and upper limits can be selectively combined to form a preferred mode.

[0048] In addition, in this specification, when the numerical range of "XX to YY" is described, it means "XX or more and YY or less".

[0049] The melt-kneaded composition and the method for producing the same according to the present embodiment are characterized in that:

[0050] The method comprises the steps of melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger,

[0051] The mixture is melt-kneaded at 300 to 380°C, and

[0052] In the step of melt-kneading, melt-kneading is performed by injecting an inert gas into the interior of a melt-kneader, or melt-kneading is performed by decompressing and degassing the interior of the melt-kneader.

[0053] The melting point of 3-methyl-1-butene polymers is as high as about 280°C or more. Therefore, even if a composition is prepared by adding an antioxidant recommended in the art for high-temperature molding, it is sometimes impossible to maintain the stability of physical properties due to thermal degradation during high-temperature melt kneading at about 300°C or more, resulting in a decrease in the mechanical properties of the molded body. The inventors of the present invention focused on the fact that 3-methyl-1-butene polymers can produce decomposition starting from alkyl radicals (R·) by high-temperature melt kneading, and prepared a composition in which an alkyl radical scavenger was added to the 3-methyl-1-butene polymer. However, even if an alkyl radical scavenger is added, it is not easy to suppress the thermal degradation caused by high-temperature melt kneading. Therefore, the inventors believed that even if an alkyl radical scavenger is used, the decomposition will be carried out by oxygen before thermal decomposition, and focused on the atmosphere conditions in the device during melt kneading. As a result, the inventors found that, in addition to adding an alkyl radical scavenger to the 3-methyl-1-butene polymer, it was effective to lower the oxygen concentration inside the melt kneader before melt kneading. The inventors further conducted studies and completed the present invention.

[0054] It should be noted that, in the present embodiment, the above-mentioned "long time" is, for example, about 15 minutes. The above-mentioned "melt-kneading process" generally includes a process of melt-kneading 3-methyl-1-butene polymer and alkyl radical scavenger in the interior of a melt-kneader. In addition, the manufacturing method of the above-mentioned melt-kneading composition or the above-mentioned "melt-kneading process" includes any one of the process of injecting an inert gas into the interior of the melt-kneader and the process of decompressing and degassing the interior of the melt-kneader, and may also include these two processes. For example, the process of injecting an inert gas can be implemented on the upstream side of the melt-kneader, and the process of decompressing and degassing can be implemented on its downstream side. The above-mentioned "injection process" or the above-mentioned "decompressed and degassing process" can be implemented in the early stage of melt-kneading 3-methyl-1-butene polymer and alkyl radical scavenger, for example, before the start of heating, before the start of shearing, before the start of heating and shearing, and is preferably continued during melt kneading.

[0055] <Method for producing melt-kneaded composition>

[0056] [3-Methyl-1-butene polymer]

[0057] The 3-methyl-1-butene polymer may be a 3-methyl-1-butene homopolymer or a copolymer of 3-methyl-1-butene and an unsaturated hydrocarbon. Examples of the unsaturated hydrocarbon include α-olefins, and α-olefins having 2 to 20 carbon atoms are preferred from the viewpoint of good copolymerizability.

[0058] From the viewpoint of suitably utilizing the physical properties of 3-methyl-1-butene, the 3-methyl-1-butene-based polymer is preferably at least one selected from a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms.

[0059] When the 3-methyl-1-butene polymer is the above copolymer, the content of the structural unit derived from the α-olefin in the copolymer is preferably more than 0 mol % and 20 mol % or less.

[0060] From the viewpoint of suitably exerting the physical properties of the α-olefin, the content of the structural unit derived from the α-olefin in the copolymer is more preferably 0.1 mol % or more, and further preferably 0.5 mol % or more.

[0061] From the viewpoint of appropriately maintaining the physical properties of 3-methyl-1-butene, the content of the structural unit derived from the α-olefin in the copolymer is more preferably 15 mol % or less, and further preferably 10 mol % or less.

[0062] The content ratio of the structural unit derived from α-olefin in the copolymer can be determined by Fourier transform infrared spectrophotometry (FT-IR). Specifically, it can be measured by the method described in Examples.

[0063] From the viewpoint of suitably exerting the physical properties of 3-methyl-1-butene, the α-olefin having 2 to 20 carbon atoms is preferably an α-olefin having 4 to 16 carbon atoms, and more preferably an α-olefin having 4 to 12 carbon atoms. The α-olefin having 2 to 20 carbon atoms may be linear or branched.

[0064] Examples of the α-olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinylcyclohexene, and vinylnorbornane.

[0065] The α-olefins having 2 to 20 carbon atoms may be used alone or in combination of two or more.

[0066] In the present embodiment, the method for producing 3-methyl-1-butene polymers is not particularly limited, and can be produced using known catalysts such as Ziegler-Natta catalysts and metallocene catalysts. The method for producing 3-methyl-1-butene polymers can be obtained in the form of powder by homopolymerizing 3-methyl-1-butene in the presence of a catalyst, or copolymerizing 3-methyl-1-butene with the above-mentioned α-olefin, as described in Japanese Patent Publication No. 61-103910.

[0067] The stereoregularity of the 3-methyl-1-butene polymer may be isotactic or syndiotactic. In addition, the copolymer may be a random copolymer, a block copolymer, or an alternating copolymer.

[0068] [Alkyl radical scavenger]

[0069] In the present embodiment, the “alkyl radical scavenger” refers to a compound having a function of reacting with an alkyl radical derived from a 3-methyl-1-butene polymer to stabilize the alkyl radical and thereby suppress the subsequent chain carbon-carbon bond dissociation reaction.

[0070] The alkyl radical scavenger preferably contains at least one selected from the group consisting of acrylic phenol compounds and benzofuranone compounds.

[0071] The alkyl radical scavengers may be used alone or in combination of two or more.

[0072] 〈Acrylic phenol compounds〉

[0073] The acrylic phenol compound used in the present embodiment can be represented by, for example, the following general formula (I).

[0074] [Chemical formula 3]

[0075]

[0076] In the general formula (I), R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 3 , R 4 , R 5 and R 6 Each independently represents an alkyl group having 1 to 9 carbon atoms.

[0077] Examples of the alkyl group having 1 to 3 carbon atoms include methyl group, ethyl group, n-propyl group and isopropyl group.

[0078] The alkyl group having 1 to 9 carbon atoms may be linear or branched.

[0079] Examples of the alkyl group having 1 to 9 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and n-nonyl.

[0080] R 1 Preferred is a hydrogen atom.

[0081] R 2 It is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

[0082] R 3 , R 4 , R 5 and R 6 Each independently is preferably an alkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 5 carbon atoms, and still more preferably a 1,1-dimethylpropyl group.

[0083] Examples of the acrylic phenol compound represented by the general formula (I) include 2,4-di-tert-amyl-6-[1-(3,5-di-tert-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2,4-di-tert-butyl-6-[1-(3,5-di-tert-butyl-2-hydroxyphenyl)ethyl]phenyl acrylate, and 2-tert-butyl-6-[(3-tert-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenyl acrylate.

[0084] The alkyl radical scavenger may be a commercially available product. Examples of the acrylic phenol compound represented by the general formula (I) include "SUMILIZER (registered trademark) GS" and "SUMILIZER (registered trademark) GM" manufactured by Sumitomo Chemical Co., Ltd., and the like.

[0085] 〈Benzofuranoside compounds〉

[0086] The benzofuranone compound used in the present embodiment can be represented by the following general formula (II), for example.

[0087] [Chemical formula 4]

[0088]

[0089] In the general formula (II), R 7 and R 8 Each independently represents an alkyl group having 1 to 4 carbon atoms, R 9 and R 10 Each independently represents an alkyl group having 1 to 9 carbon atoms.

[0090] Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0091] The alkyl group having 1 to 9 carbon atoms may be linear or branched. Examples of the alkyl group having 1 to 9 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-nonyl.

[0092] R 7 and R 8 Each independently is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.

[0093] R 9 and R 10 Each independently is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a tert-butyl group.

[0094] Examples of the benzofuranone compound represented by the general formula (II) include 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one, 5,7-di-tert-butyl-3-(3,4-dipropyl-phenyl)-3H-benzofuran-2-one, and 4-tert-butyl-2-(5-tert-butyl-2-oxo-3H-benzofuran-3-yl)phenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

[0095] The alkyl radical scavenger may be a commercially available product. Examples of the benzofuranone compound represented by the general formula (II) include "Irganox (registered trademark) HP-136" manufactured by BASF and "Revonox (registered trademark) 501" manufactured by Chitec.

[0096] 〈Amount of Compounding〉

[0097] The amount of the alkyl radical scavenger to be added is preferably 0.01 to 1.00 part by mass relative to 100 parts by mass of the 3-methyl-1-butene polymer.

[0098] If the amount of the alkyl radical scavenger is within the above numerical range, the stability of the physical properties of the melt-kneaded composition can be maintained during melt-kneading. In addition, there is no concern that the physical properties required for the resin composition will be impaired, such as the alkyl radical scavenger seeping out or the hygroscopicity deteriorating. In addition, there is no concern that decomposition gas will be generated during melt molding and poor molding.

[0099] From the viewpoint of more easily exhibiting the effects of the present invention, the amount of the alkyl radical scavenger blended is more preferably 0.02 parts by mass or more, and even more preferably 0.05 parts by mass or more, based on 100 parts by mass of the 3-methyl-1-butene polymer.

[0100] From the viewpoint of the balance between the effects of the present invention and economic efficiency, the amount of the alkyl radical scavenger is more preferably 0.80 parts by mass or less, and even more preferably 0.70 parts by mass or less, based on 100 parts by mass of the 3-methyl-1-butene polymer.

[0101] In addition, when two or more alkyl radical scavengers are blended, the blending amount of the alkyl radical scavengers mentioned above refers to the total blending amount of the alkyl radical scavengers.

[0102] [Antioxidants]

[0103] From the viewpoint of heat aging resistance, in the process of melt-kneading, at least one antioxidant selected from phenolic antioxidants and phosphorus antioxidants can be further coordinated to carry out melt-kneading. In addition, in the process of melt-kneading, melt-kneading can also be carried out without coordination of antioxidants.

[0104] The antioxidant may be used alone or in combination of two or more.

[0105] 〈Phenolic antioxidants〉

[0106] Examples of the phenolic antioxidant include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione. triketone, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, diethylenethioate-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 3,3',3'',5,5',5''-hexa-tert-butyl-α,α',α''-(mesitylene-2,4,6-triyl) tris(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide) Cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-[4,6-bis(octylthio)-1,3,5-triazine-2-ylamino]phenol, 3,9-bis[2-(3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-di methylethyl]-2,4,8,10-tetraoxaspiro(5,5)undecane, 4,4',4''-(1-methylpropyl-3-ylidene)tri(6-tert-butyl-m-cresol), 6,6'-di-tert-butyl-4,4'-butylene-di-m-cresol, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, and phenylpropionic acid 3,5-bis-(1,1-dimethylethyl)-4-hydroxy-C7-C9 branched alkyl ester, etc.

[0107] As the phenolic antioxidant, commercially available products may be used, and examples thereof include “ADK STAB (registered trademark) AO series” manufactured by ADEKA Corporation and “Irganox (registered trademark) series” manufactured by BASF JAPAN Corporation.

[0108] 〈Phosphorus antioxidants〉

[0109] Phosphorus antioxidants include, for example, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite , bis(2,4-dicumylphenyl)pentaerythritol diphosphite, di-tert-butyl m-tolylphosphite, diethyl [(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl]phosphonate, tris(2,4-di-tert-butylphenyl)phosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris(2,4-di-tert-butylphenyl)phosphite, tris(nonylphenyl)phosphite, tetra-C 12 -C 15 -alkyl [propane-2,2-diylbis(4,1-phenylene)]bis(phosphite), 2-ethylhexyl diphenyl phosphite, isodecyl diphenyl phosphite, triisodecyl phosphite, triphenyl phosphite, and 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, etc.

[0110] As the phosphorus-based antioxidant, commercially available products may be used, and examples thereof include "ADK STAB (registered trademark) PEP series" and "ADK STAB (registered trademark) HP series" manufactured by ADEKA, "Irgafos (registered trademark) series" manufactured by BASF JAPAN, and "HOSTANOX (registered trademark) P-EPQ" manufactured by Clariant.

[0111] 〈Other antioxidants〉

[0112] In addition, in the process of melt kneading, other antioxidants other than phenolic antioxidants and phosphorus antioxidants may be added as long as the effects of the present invention are not impaired. Antioxidants other than phenolic antioxidants and phosphorus antioxidants include, for example, sulfur antioxidants and amine antioxidants.

[0113] 〈Amount of Compounding〉

[0114] From the viewpoint of more easily exhibiting heat aging resistance, the amount of the antioxidant blended relative to 100 parts by mass of the 3-methyl-1-butene polymer is preferably 0.01 parts by mass or more, and more preferably 0.10 parts by mass or more.

[0115] From the viewpoint of economic efficiency, the amount of the antioxidant to be added is preferably 1.00 part by mass or less, and more preferably 0.80 part by mass or less, based on 100 parts by mass of the 3-methyl-1-butene polymer.

[0116] In addition, when two or more antioxidants are blended, the blending amount of the antioxidants mentioned above means the total blending amount of the antioxidants.

[0117] [Other additives]

[0118] In the melt-kneading step, in addition to the 3-methyl-1-butene polymer, the alkyl radical scavenger and the antioxidant, other additives may be blended and melt-kneaded.

[0119] Other additives include, for example, antacids, fillers, light stabilizers, antistatic agents, flame retardants, pigments, polymerization inhibitors, heavy metal deactivators, ultraviolet absorbers, nucleating agents, transparent agents, lubricants, fluorescent brighteners, and rust inhibitors.

[0120] The other additives may be used alone or in combination of two or more.

[0121] 〈Antacids〉

[0122] In order to suppress deterioration caused by acid components generated from residual metal components and the like, it is preferred that an antacid is further blended during the melt-kneading step.

[0123] Examples of the antacid include barium laurate, calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, zinc oleate, and 12-hydroxymagnesium stearate.

[0124] The antacid may be used alone or in combination of two or more.

[0125] The amount of the antacid to be added to 100 parts by mass of the 3-methyl-1-butene polymer can be appropriately determined depending on the application of the melt-kneaded composition, and may be, for example, 0.01 to 200 parts by mass.

[0126] 〈Fillers〉

[0127] Depending on the purpose of the melt-kneaded composition, in addition to the 3-methyl-1-butene polymer and the alkyl radical scavenger, a filler may be further added for melt-kneading. Alternatively, the melt-kneaded composition may be melt-kneaded again after adding a filler.

[0128] Fillers include fibrous compounds such as glass fiber, alumina fiber, resin fiber, carbon fiber, cellulose fiber, etc.; flat compounds such as mica, talc, montmorillonite, flat aluminum, etc.; spherical compounds such as glass beads, white sand balls (Japanese: シラスバルーン), acrylic balls, etc.; needle-shaped compounds such as needle-shaped metal titanates, wollastonite, needle-shaped silica, tin oxide, etc.; powdered metal titanates, micronized wood chips, titanium oxide, calcium carbonate, silica, aluminum oxide, etc. Powdered compounds, etc. These fillers can be surface treated with, for example, a silane coupling agent. In addition, a compatibilizer can be used to improve the dispersibility of the filler.

[0129] The filler may be used alone or in combination of two or more.

[0130] The amount of the filler to be added relative to 100 parts by mass of the 3-methyl-1-butene polymer can be appropriately determined depending on the application of the melt-kneaded composition, and may be, for example, 0.01 to 300 parts by mass.

[0131] [Melt-kneading conditions]

[0132] 〈Inactive atmosphere〉

[0133] The manufacturing method of the present embodiment has a step of melt-kneading 3-methyl-1-butene polymer and alkyl radical scavenger at 300 to 380°C and in a low oxygen state lower than the atmosphere. This manufacturing method preferably also includes a step of injecting an inert gas into the interior of a melt-kneader, and performing the melt-kneading in the above-mentioned melt-kneader. By injecting an inert gas, preferably continuing to inject an inert gas, a low oxygen state inside the melt-kneader can be achieved. This manufacturing method preferably also includes a step of degassing the interior of the melt-kneader under reduced pressure, and performing the melt-kneading in the above-mentioned melt-kneader. By degassing under reduced pressure, preferably continuing to degassing under reduced pressure, a low oxygen state inside the melt-kneader can be achieved. This manufacturing method preferably also includes a step of injecting an inert gas into the interior of the melt-kneader and a step of degassing the interior of the melt-kneader under reduced pressure, and performing the melt-kneading in the above-mentioned melt-kneader.

[0134] In one mode of the production method of the present embodiment, in the step of melt-kneading the 3-methyl-1-butene polymer and the alkyl radical scavenger, melt-kneading is performed by injecting an inert gas into the interior of the melt-kneader, or by degassing the interior of the melt-kneader under reduced pressure.

[0135] In the production method of the present embodiment, in order to produce a melt-kneaded composition that can suppress the reduction in physical properties of the melt-kneaded composition caused by oxygen, effectively exert the function of the alkyl radical scavenger, and obtain a molded body with good mechanical properties, it is important to carry out melt-kneading under an inert atmosphere or a low-oxygen state.

[0136] Here, in the present embodiment, "hypoxic state" refers to a state in which the oxygen concentration inside the melt kneader is lower than before decompression and degassing by decompressing and degassing the inside of the melt kneader. In addition, in the state of "inert atmosphere", by injecting inert gas into the inside of the melt kneader, the oxygen concentration inside the melt kneader is lower than before the injection of inert gas. Therefore, the concept of "hypoxic state" may include the state of "inert atmosphere". In the "hypoxic state", the oxygen concentration inside the melt kneader is preferably less than 5%, more preferably less than 2%, and further preferably less than 1%. In addition, the measurement of the above-mentioned oxygen concentration is set to a value performed using an oxygen concentration meter, preferably set to a value performed using a diaphragm type galvanic type, more preferably set to a value performed using an oxygen concentration meter such as a diaphragm type galvanic battery type, a galvanic battery type, etc. In more detail, the oxygen concentration can be measured by the method described in the embodiment. As the oxygen concentration meter, for example, "XP-3180E" (diaphragm type galvanic cell type) manufactured by Shin-Cosmos Electric Co., Ltd. and its successor "XP-3380II-E" (galvanic cell type) can be used.

[0137] The method of melt kneading by injecting an inert gas into the interior of the melt kneader can be, for example, melt kneading by injecting each component into the melt kneader while injecting the inert gas into the interior of the melt kneader, or melt kneading by injecting the inert gas after injecting each component into the interior of the melt kneader, preferably before starting to heat up or before starting to shear, more preferably before starting to heat up and before starting to shear, or melt kneading by injecting the inert gas into the interior of the melt kneader and then injecting each component from a sealed supply portion. In addition, during the melt kneading, the inert gas can be continuously injected into the interior of the melt kneader.

[0138] The method of injecting the inert gas can be carried out according to the equipment equipped in each melt-kneading machine. For example, it can be carried out from the supply section of the inert gas or other gas equipped in the melt-kneading machine, from the supply section of each component equipped in the melt-kneading machine, or from the exhaust port equipped in the melt-kneading machine.

[0139] There is no limitation on the method of injection as long as the inert gas can be injected into the entire area from the inert gas supply section to the heating section where melt-kneading is performed to perform melt-kneading.

[0140] Examples of the inert gas include nitrogen, helium, neon, argon, krypton, and carbon dioxide. Nitrogen is preferred from the viewpoint of high availability and versatility.

[0141] The method of melt-kneading by degassing the inside of the melt-kneader, for example, can be performed by putting in each component while degassing the inside of the melt-kneader, or can be performed by degassing the inside of the melt-kneader after putting in each component, preferably before starting to heat up or before starting to shear, more preferably before starting to heat up and before starting to shear, or can be performed by degassing the inside of the melt-kneader after degassing the inside of the melt-kneader, and then putting in each component from the sealed supply part to melt-knead. In addition, degassing the inside of the melt-kneader can be performed intermittently or continuously during melt-kneading.

[0142] The method of degassing the inside of the melt-kneading machine under reduced pressure can be carried out according to the equipment equipped in each melt-kneading machine, for example, it can be carried out from a vacuum exhaust port. For degassing under reduced pressure, for example, a reduced pressure pump can be used.

[0143] Regarding the reduced pressure degassing inside the melt-kneader, there is no limitation on the reduced pressure degassing method as long as melt-kneading can be performed under a low oxygen state.

[0144] When degassing under reduced pressure is performed, the interior of the melt-kneading machine can be set to a vacuum state of, for example, 50 kPa or less and 0.1 kPa or more.

[0145] The melt kneader may be a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, or the like, which is capable of injecting an inert gas into the melt kneader for melt kneading or capable of decompressing and degassing the inside of the melt kneader for melt kneading.

[0146] The above-mentioned inert gas injection and degassing under reduced pressure may also be used in combination. In this case, it is preferred that the inert gas is injected into the upstream side of the melt kneader before the raw materials are added or together with the raw materials, and degassing under reduced pressure is performed on the downstream side. It is more preferred that the injection of the inert gas and degassing under reduced pressure are continued during the melt kneading.

[0147] 〈Temperature and time, etc.〉

[0148] In the production method of the present embodiment, the melt kneading is performed at 300 to 380°C.

[0149] If the melt kneading temperature is lower than 300° C., the 3-methyl-1-butene polymer will not be sufficiently melted, and the dispersion of the alkyl radical scavenger and additives will become insufficient. If the melt kneading temperature exceeds 380° C., the decomposition of raw materials such as the 3-methyl-1-butene polymer and the alkyl radical scavenger will become significant, and the sufficient effect of the invention cannot be obtained.

[0150] From the viewpoint of sufficiently dispersing the alkyl radical scavenger and additives throughout the entire 3-methyl-1-butene polymer, the melt-kneading temperature is preferably 300° C. or higher, more preferably 310° C. or higher.

[0151] From the viewpoint of suppressing significant decomposition of the raw materials, the melt-kneading temperature is preferably 380° C. or lower, more preferably 360° C. or lower.

[0152] The melt-kneading time can be adjusted according to the size of the kneading device, etc. For example, it can be 1 to 15 minutes, but it is not limited to the numerical range of the melt-kneading time. In addition, in the present embodiment, the "melt-kneading time" refers to the time for rotating the mixer in the case of an intermittent kneading machine, and refers to the residence time of the raw materials in the device in the case of a continuous extrusion kneading machine. It is preferred to continue to maintain the above-mentioned low oxygen state throughout the melt-kneading time.

[0153] The manufacturing method of the present embodiment is not prone to causing a decrease in physical properties due to high-temperature melt kneading. Therefore, the longer the melt kneading time (about 15 minutes in the present embodiment), the easier it is to exert the effect of the present invention that a melt kneading resin composition can be manufactured with good productivity, and the melt kneading resin composition can obtain a molded body that maintains the physical property stability of the melt and has good mechanical properties.

[0154] The larger the melt kneader, the more the production volume increases and the longer the melt kneading time is, so the possibility of the physical property degradation of the melt kneading composition is also higher. However, if it is the manufacturing method of this embodiment, the stability of the physical property can be maintained, so the melt kneading resin composition with good mechanical properties can be manufactured with good productivity.

[0155] The mixer rotation speed during melt kneading may be 80 rpm or more or 100 rpm or more, or 400 rpm or less or 350 rpm or less.

[0156] After melt-kneading, the melt-kneaded composition is taken out from the melt-kneader and cooled.

[0157] <Melt-kneaded composition>

[0158] The present embodiment provides a melt-kneaded composition produced by the above-mentioned method for producing a melt-kneaded composition.

[0159] For the melt-kneaded composition manufactured by the manufacture method of the above-mentioned melt-kneaded composition, for example, a part of the 3-methyl-1-butene-based polymer may decompose due to the high temperature during melt-kneading, the high temperature and shearing according to the situation, and in addition, the amount of the alkyl radical scavenger is small, so it is difficult to accurately define the decomposed alkyl radical scavenger. Therefore, there is currently the following situation: clearly analyzing and determining the structure of the melt-kneaded composition containing the above-mentioned decomposition product, the reaction product of the 3-methyl-1-butene-based polymer and the alkyl radical scavenger, etc. is difficult at present. Therefore, with regard to the melt-kneaded composition, it is impossible or impractical to directly determine according to the specific chemical structure, etc. in the current technology, so there is a situation determined according to its manufacture method. Nevertheless, as illustrated in the embodiment one column, the melt-kneaded composition manufactured by the manufacture method of the above-mentioned melt-kneaded composition is compared with the melt-kneaded composition manufactured by the method other than the manufacture method of the above-mentioned melt-kneaded composition, and obviously maintains the stability of physical properties.

[0160] It should be noted that a part or all of the undecomposed alkyl radical scavenger present in the melt-kneaded composition may be detected.

[0161] In the absence of an antioxidant, the total content of the 3-methyl-1-butene polymer and the alkyl radical scavenger in the melt-kneaded composition is preferably 99.0% by mass or more, more preferably 99.5% by mass or more. The upper limit of the total content is not limited as long as it does not damage the effect of the invention, for example, it can be 100% by mass or less, or it can be 99.9% by mass or less.

[0162] In addition, when containing the above-mentioned antioxidant, the total content of the 3-methyl-1-butene polymer, the alkyl radical scavenger and the antioxidant in the melt-kneaded composition is preferably 99.0% by mass or more, more preferably 99.5% by mass or more. The upper limit of the total content is not limited as long as it does not damage the effect of the invention, for example, it can be 100% by mass or less, or it can be 99.9% by mass or less.

[0163] In addition, in this specification, the said "content ratio" is calculated based on the compounding quantity of each component used for the melt-kneaded composition.

[0164] As described above, after melt kneading, part or all of the blended 3-methyl-1-butene polymer and alkyl radical scavenger react or decompose, or evaporate, making it difficult to determine the exact content ratio of each component.

[0165] Melting Point

[0166] The melting point of the melt-kneaded composition of the present embodiment is preferably 280 to 310° C. When the melting point of the melt-kneaded composition is within the above range, the composition has excellent heat resistance and can appropriately exhibit the characteristics of the 3-methyl-1-butene polymer.

[0167] It should be noted that the melting point of the melt-kneaded composition of the present embodiment is almost the same as the melting point of the 3-methyl-1-butene polymer used in the raw material. Therefore, in this specification, the melting point of the 3-methyl-1-butene polymer used in the raw material can be regarded as the melting point of the melt-kneaded composition. The melting point can be measured by the method described in the examples.

[0168] 〈Melt viscosity〉

[0169] The melt-kneaded composition of this embodiment is subjected to a cylinder temperature of 320°C and a shear rate of 1220 sec. -1 The melt viscosity of the melt-kneaded composition is preferably 10 to 1000 Pa·s, more preferably 20 to 500 Pa·s. If the melt viscosity of the melt-kneaded composition is 10 Pa·s or more, the strength of the molded body becomes good. In addition, if the melt viscosity of the melt-kneaded composition is 1000 Pa·s or less, the fluidity during molding becomes good.

[0170] The melt viscosity of the melt-kneaded composition can be measured by the method described in Examples.

[0171] 〈Forming method〉

[0172] According to the purpose of the melt-kneaded composition, the 3-methyl-1-butene polymer, the alkyl radical scavenger and other additives such as antioxidants and fillers that are matched as needed can be continuously molded together. Alternatively, the melt-kneaded composition can be melt-molded again after being temporarily taken out. As a molding method, for example, common molding methods such as injection molding, extrusion molding, hollow molding and vacuum molding can be used.

[0173] 〈Breaking Strength〉

[0174] The melt-kneaded composition of the present embodiment preferably has a breaking strength of 10 MPa or more, more preferably 25 MPa or more, as measured on a molded article thereof in accordance with JIS K 7161-1: 2014. If the breaking strength is 10 MPa or more, it is considered to have good mechanical strength.

[0175] The breaking strength can be measured by the method described in the Examples.

[0176] Example

[0177] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

[0178] <Measurement and evaluation methods>

[0179] Various physical properties were measured or evaluated by the following methods.

[0180] [Content ratio of the structural unit derived from the comonomer]

[0181] In Production Examples 1 and 2, FT-IR (manufactured by Ailent Technologies, device name: "cary 600 series FTIR spectrometer") was used as an analysis device, and IR measurement was performed by the ATR method to determine the content ratio of the structural unit derived from the α-olefin (comonomer) other than 3-methyl-1-butene in the 3-methyl-1-butene-based copolymer as follows.

[0182] According to the variable angle vibration of the main chain methylene group from 3-methyl-1-butene homopolymer 1,461 cm -1 The peak area is related to the variable angle vibration of the side chain methylene of the homopolymer of α-olefin at 727 cm -1 The 3-methyl-1-butene copolymer obtained in the manufacturing example was subjected to the above IR measurement, and the obtained measured values ​​were inserted into the above calibration curve to obtain the content ratio of the structural unit derived from α-olefins other than 3-methyl-1-butene.

[0183] [Melting point]

[0184] The copolymer or homopolymer obtained in the production example was heated from 30°C to 320°C at 10°C / min under a nitrogen flow rate (100 mL / min) using a differential scanning calorimeter ("DSC25" manufactured by TA Instrument Co., Ltd.), maintained at 320°C for 5 minutes, and then cooled to -70°C at 10°C / min. After being maintained at -70°C for 5 minutes, the melting point was measured when the temperature was increased to 320°C at 10°C / min.

[0185] [Melt viscosity]

[0186] In Examples 1, 7, and 8, the components shown in Table 1 were blended and subjected to flow measurement using a capillary rheometer (“Capilograph 1C” manufactured by Toyo Seiki Seisaku-sho, Ltd.) at a cylinder temperature of 320° C. and a shear rate of 1220 sec. -1 The melt viscosity (Pa·s) of the melt-kneaded composition was measured under the conditions of (capillary: inner diameter 1.0 mm×length 10 mm, extrusion speed 10 mm / min).

[0187] [Stability of physical properties during melt kneading]

[0188] (1) Preparation of test pieces for complex shear viscosity measurement

[0189] In the examples and comparative examples, the components shown in Table 1 or 2 were kneaded for 4 minutes at 200 rpm and 320° C. in a nitrogen atmosphere using a small kneading machine (“Micro 15 Compounder” manufactured by DSMXplore). After kneading, the melt-kneaded composition was drawn out in a strand form and cut into a length of about 1 mm.

[0190] The melt-kneaded composition was decompressed to -0.1 MPaG using a reduced pressure hot press (IMC-183B manufactured by Imoto Seisakusho Co., Ltd.) using an oil rotary pump, preheated at 320°C for 2 minutes, and then pressed at 70 kN (1.7 MPa) for 2 minutes. Then, a cooling press equipped with water flow cooling was used at 70 kgf / cm 2 The pressed plate was pressed at 6.9 MPa for 2 minutes to produce a pressed plate with a thickness of 0.5 mm. A cylindrical test piece with a diameter of 8 mm was cut out from the obtained pressed plate.

[0191] (2) Temporal changes in complex shear viscosity

[0192] In accordance with ISO6721-10:1999, a strain-controlled dynamic viscoelasticity device “ARES-G2” (manufactured by TA Instruments Japan) having a circular plate diameter of 8 mm was used as a parallel plate vibration rheometer.

[0193] The gap between the two plates was completely filled with the test piece, and the strain was 0.1%, the temperature was 320°C, and the angular frequency was 100 rad·s -1 The test piece is melt-kneaded under a nitrogen atmosphere or an air atmosphere (under atmospheric conditions) while being vibrated.

[0194] After the melt kneading starts, the complex shear viscosity is measured every 8.5 seconds from 60 seconds to 1500 seconds. The logarithmic value of the complex shear viscosity decreases linearly with the measurement time, and the slope is calculated. The stability of the physical properties during melt kneading is evaluated based on the absolute value of the value.

[0195] The evaluation results are shown in Table 1 or 2. The smaller the slope (absolute value of the numerical value), the more stable the physical properties of the melt-kneaded composition are maintained.

[0196] (3) Complex shear viscosity retention rate

[0197] The complex shear viscosity retention rate was calculated from the values ​​of the complex shear viscosity measured under the above conditions 4 minutes after and 15 minutes after the start of kneading.

[0198] Complex shear viscosity retention rate (%) = (complex shear viscosity 15 minutes after the start of kneading / complex shear viscosity 4 minutes after the start of kneading) × 100

[0199] The evaluation results are shown in Table 1 or 2. A larger value of the complex shear viscosity retention rate (%) indicates that the stability of the physical properties is maintained.

[0200] [Breaking strength]

[0201] In Example 1 and Comparative Example 1, each component shown in Table 1 or 2 was melt-kneaded using a small kneader (“Micro 15 Compounder” manufactured by DSMXplore) at 200 rpm and 320° C. in a nitrogen atmosphere.

[0202] The melt-kneaded composition at each time after 4 minutes and 15 minutes from the start of the above-mentioned melt-kneading was molded into a small test piece (1BA-shaped dumbbell test piece described in Appendix A of JIS7161-2) using a small injection molding machine ("Micro Injection Molding Machine 10cc" manufactured by DSMXplore) under the conditions of injection pressure 0.3 MPa, mold retention time 35 seconds, and mold temperature 180°C.

[0203] The prepared dumbbell test piece was stored at 23°C and 49% humidity for more than 24 hours, and the breaking strength (MPa) was measured at 23°C and 49% humidity at a tensile speed of 5 mm / min using a universal material testing machine (Instron Corporation "INSTRON5900R-5666") in accordance with JIS K 7161-1:2014. The measurement was performed 5 times each, and the average value was used.

[0204] The strength retention rate was calculated based on the following formula from the above-mentioned breaking strength of the dumbbell test pieces produced under the above-mentioned conditions 4 minutes after and 15 minutes after the start of the melt-kneading.

[0205] Strength retention rate (%) = (Breaking strength of dumbbell test piece produced under the conditions 15 minutes after the start of kneading / Breaking strength of dumbbell test piece produced under the conditions 4 minutes after the start of kneading) × 100

[0206] The evaluation results are summarized in Table 3. A larger value of the strength retention rate (%) indicates that the tensile properties are more maintained.

[0207] [Analysis of the amount of additives contained in the melt-kneaded composition]

[0208] The melt-kneaded compositions obtained in Example 1 and Comparative Example 5 were molded by injection molding, and the obtained molded pieces were frozen and crushed to form powders. About 25 g of the obtained powder was accurately weighed and Soxhlet extraction was performed with chloroform for 8 hours. After extraction, the mixture was concentrated with an evaporator (40° C.) and vacuum dried (40° C., 6 hours). About 20 mg of the obtained solid component was accurately weighed, the volume was fixed to 10 mL with acetonitrile, and HPLC was performed to calculate the amount of components (additives) other than the 3-methyl-1-butene polymer.

[0209] <HPLC analysis>

[0210] Device: ACQUITY UPLC H-class

[0211] Column: ACQUITY UPLC BEH C18 2.1×100mm, 1.7μm (waters)

[0212] Mobile phase: Liquid A: 0.1 mass% formic acid aqueous solution, Liquid B: acetonitrile / tetrahydrofuran = 1 / 1 (volume ratio)

[0213] Gradient conditions (B solution concentration): 0-3 minutes…50%, 3-7.1 minutes…95%, 7.1-10 minutes…50%

[0214] Flow rate: 0.4mL / min

[0215] Temperature: 40℃

[0216] Detector: PDA (280nm), ELSD

[0217] Injection volume: 5μL

[0218] [Measurement method of oxygen concentration]

[0219] In the Examples and Comparative Examples, the oxygen concentration was measured in parallel with the measurement of the temporal change of the complex shear viscosity described above using an oxygen concentration meter (“XP-3180E” manufactured by Shin Cosmos Electric Co., Ltd.) airtightly installed in a strain-controlled dynamic viscoelasticity apparatus “ARES-G2” (manufactured by TA Instruments Japan).

[0220] In Examples 1 to 8 and Comparative Examples 1 to 4, 7, and 8, the oxygen concentration inside the hopper was measured using an oxygen concentration meter (XP-3180E manufactured by Shin-COSMOS Electric Co., Ltd.) airtightly installed in the hopper installed in a small mixer (Micro 15 Compounder manufactured by DSMXplore). The measurement of the oxygen concentration was started after nitrogen was continuously injected into the small mixer for at least 10 minutes. Nitrogen was continuously injected during the oxygen concentration measurement. While nitrogen was continuously injected, the components shown in Table 1 or 2 were subsequently added and melt-kneaded.

[0221] [Each ingredient]

[0222] The components used in Examples and Comparative Examples are as follows.

[0223] 〈3-Methyl-1-butene polymer (P3MB)〉

[0224] Copolymer (A): 3-methyl-1-butene copolymer produced in Production Example 1

[0225] · Copolymer (B): 3-methyl-1-butene copolymer produced in Production Example 2

[0226] Homopolymer (C): 3-methyl-1-butene homopolymer produced in Production Example 3

[0227] 〈Alkyl radical scavenger〉

[0228] ·A-1: 2,4-di-tert-pentyl-6-[1-(3,5-di-tert-pentyl-2-hydroxyphenyl)ethyl]phenyl acrylate, trade name "SUMILIZER (registered trademark) GS", manufactured by Sumitomo Chemical Co., Ltd.

[0229] ·A-2: 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one, manufactured by Tokyo Chemical Industry Co., Ltd.

[0230] 〈Phenolic antioxidants〉

[0231] ·B-1: Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], trade name "AO-60", manufactured by ADEKA

[0232] ・B-2: 1,3,5-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trade name "ADK STAB (registered trademark) AO-20", manufactured by ADEKA Corporation

[0233] 〈Phosphorus antioxidants〉

[0234] ·C-1: 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, trade name "ADK STAB (registered trademark) PEP-36", manufactured by ADEKA Corporation

[0235] C-2: A composition containing tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenephosphonite as the main component, trade name "HOSTANOX (registered trademark) P-EPQ", manufactured by Clariant

[0236] 〈Sulfur antioxidants〉

[0237] ·D-1: 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propionate], trade name "ADK STAB (registered trademark) AO-412S", manufactured by ADEKA Corporation

[0238] 〈Catechols〉

[0239] ·E-1: 4-tert-butyl-pyrocatechol, manufactured by Tokyo Chemical Industry Co., Ltd.

[0240] 〈Nitroxyl radicals (Japanese: Nitroxyl radicals)〉

[0241] ·E-2: Bis(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) sebacate, manufactured by Tokyo Chemical Industry Co., Ltd.

[0242] 〈Other additives〉

[0243] Antacid: Zinc stearate

[0244] [Preparation of catalyst]

[0245] Preparation of titanium catalyst components

[0246] 47.6 g (500 mmol) of anhydrous magnesium chloride, 250 mL of decane, and 234 mL (1.5 mol) of 2-ethylhexanol were heated at 130°C for 2 hours to make a uniform solution. After the obtained uniform solution was cooled to room temperature (23°C), it was added dropwise to 2 L (18 mol) of titanium tetrachloride maintained at -20°C over 1 hour. After the addition was completed, the temperature of the mixed solution was raised to 110°C over 2 hours, and 42.4 mL (160 mmol) of dibutyl phthalate was added when it reached 110°C, and it was kept at the same temperature for 2 hours while stirring. After the 2-hour reaction was completed, the supernatant was removed after standing. Decane and hexane were added to it, and the solid components were washed 3 times, and then it was resuspended with 2 L of titanium tetrachloride and heated again at 110°C for 2 hours. After the reaction was completed, the mixture was repeatedly allowed to stand again with decane and hexane, and the supernatant was removed, and it was fully washed until no free titanium compound was detected in the washing liquid. The obtained suspension component was dried under reduced pressure at room temperature for 6 hours to obtain a dried titanium catalyst component.

[0247] The composition of the obtained titanium catalyst component was 4.0 mass % of titanium, 56.0 mass % of chlorine, 17.0 mass % of magnesium, and 11.0 mass % of dibutyl phthalate.

[0248] [Production Example 1]

[0249] Production of copolymer (A)

[0250] 8.0 kg of 3-methyl-1-butene, 0.6 kg of 1-decene, 50 g of triethylaluminum diluted with hexane to a concentration of 1 mol / L, and 4 g of the titanium catalyst component produced in the above [Preparation of Catalyst] were added to a 20 L stainless steel autoclave, and a polymerization reaction was carried out at 70°C for 4 hours. During the polymerization reaction, hydrogen was continuously supplied at a rate of 40 mL / min. After 4 hours, 200 g of isoamyl alcohol was pressed in to stop the reaction and remove the remaining unreacted monomers. Next, 2 kg of n-heptane was introduced, and after stirring at 60°C for 30 minutes, the solid component was filtered out with a pressure filter. After repeating this operation twice, the solvent was changed from 2 kg of n-heptane to 3 kg of 2-propanol, and the same operation was repeated twice.

[0251] 7.7 kg of the obtained crude polymer was added to a 50 L container equipped with a stirrer, and then 8 kg of 1 mol / L hydrochloric acid and 16 kg of 2-propanol were added and stirred for 1 hour. The suspension was filtered out by vacuum filtration and rinsed with 10 kg of 2-propanol. The washed polymer was dried under reduced pressure at 80° C. for 2 days, thereby obtaining 3.2 kg of a copolymer of 3-methyl-1-butene and 1-decene, namely, copolymer (A).

[0252] The above-mentioned measurement of the obtained copolymer (A) revealed that the melting point was 296° C. The content of the structural unit derived from 1-decene as a comonomer in the copolymer (A) was 1.1 mol %. The melt viscosity of the melt-kneaded composition obtained in Example 1 was 104 Pa·s.

[0253] [Production Example 2]

[0254] Production of copolymer (B)

[0255] The same operation as in Production Example 1 was carried out except that 0.6 kg of 1-decene was changed to 3.6 kg of 1-decene, thereby obtaining 2.8 kg of a copolymer (B) of 3-methyl-1-butene-1-decene.

[0256] The above-mentioned measurement of the obtained copolymer (B) revealed that the melting point was 281° C. The content of the structural unit derived from 1-decene as a comonomer in the copolymer (B) was 6.4 mol %. The melt viscosity of the melt-kneaded composition obtained in Example 7 was 99 Pa·s.

[0257] [Production Example 3]

[0258] Preparation of homopolymer (C)

[0259] The same operation as in Production Example 1 was carried out except that 0.6 kg of 1-decene was not added, thereby obtaining 3.3 kg of a homopolymer (C) of 3-methyl-1-butene.

[0260] The above-mentioned measurement was performed on the obtained homopolymer (C), and the melting point was 305° C. The melt viscosity of the melt-kneaded composition obtained in Example 8 was 126 Pa·s.

[0261] [Example 1]

[0262] Using the components shown in Table 1, the melt-kneaded compositions were evaluated according to the above-mentioned evaluation methods of [Stability of Physical Properties During Melt-kneading] and [Strength Retention].

[0263] In addition, regarding the evaluation results of the above-mentioned [Analysis of the amount of additives contained in the melt-kneaded composition], the amount of additives contained in the injection molded sheet with a kneading time of 4 minutes was as follows: A-1 was 520 mass ppm, B-1 was 1,100 mass ppm, and C-1 was 490 mass ppm. The amount of additives contained in the injection molded sheet with a kneading time of 15 minutes was as follows: A-1 was 170 mass ppm, B-1 was 520 mass ppm, and C-1 was 130 mass ppm.

[0264] [Examples 2 to 8 and Comparative Examples 1 to 8]

[0265] The same test and evaluation as in Example 1 were carried out except that the components and the blending amounts of the composition were changed as shown in the table. The results are shown in Table 1 or 2.

[0266] In Comparative Example 5, regarding the evaluation results of the above-mentioned [Analysis of the amount of additives contained in the melt-kneaded composition], the amount of additives contained in the injection molded sheet with a kneading time of 4 minutes was as follows: A-1 was 400 mass ppm, B-1 was 965 mass ppm, and C-1 was 536 mass ppm. The amount of additives contained in the injection molded sheet with a kneading time of 15 minutes was as follows: A-1 was 61 mass ppm, B-1 was 1183 mass ppm, and C-1 was 263 mass ppm.

[0267]

[0268]

[0269]

[0270] 〈Investigation〉

[0271] It can be seen that although the amount of antioxidant added is large in Comparative Example 1 compared to Example 1, the alkyl radical scavenger is not added, so the absolute value of the numerical value representing the slope of the logarithmic value of the complex shear viscosity from the measurement time of 60 seconds to 900 seconds is large, and the viscosity retention rate and the strength retention rate both show small values, that is, the 3-methyl-1-butene polymer deteriorates rapidly during melt kneading. In addition, from the comparison between Example 1 and Comparative Example 1, it can be seen that the smaller the absolute value of the numerical value representing the slope of the logarithmic value of the complex shear viscosity from the measurement time of 60 seconds to 900 seconds, the higher the strength retention rate, that is, the higher the mechanical strength of the molded body can be maintained.

[0272] According to Example 2, it is understood that the effects of the present invention are exhibited even when the alkyl radical scavenger is a benzofuranone.

[0273] According to Examples 1, 3 and 4, it is known that the alkyl radical scavenger alone has the effect of suppressing the degradation of the 3-methyl-1-butene polymer during melt kneading, regardless of the presence or absence of an antioxidant. On the other hand, according to Comparative Example 3, it is known that there is no effect without the alkyl radical scavenger.

[0274] According to Examples 1 and 5, even when the amount of the alkyl radical scavenger added is 0.02 parts by mass, there is an effect of suppressing the degradation of the 3-methyl-1-butene polymer during melt kneading.

[0275] According to Example 6 and Comparative Example 2, the composition containing an antioxidant described in Patent Document 1 has a certain effect of suppressing the degradation of 3-methyl-1-butene polymer during melt kneading compared to the composition without adding a stabilizer, but it is not sufficient, and an alkyl radical scavenger is necessary. In addition, according to Comparative Example 4, it is known that in the composition containing an antioxidant described in Patent Document 2, the degradation of 3-methyl-1-butene polymer during melt kneading is not sufficiently suppressed.

[0276] According to Examples 7 and 8, even a 3-methyl-1-butene copolymer or a 3-methyl-1-butene homopolymer having a high copolymerization ratio has the effect of suppressing deterioration during melt kneading by the alkyl radical scavenger.

[0277] According to Example 1 and Comparative Examples 1, 5 and 6, the effect of suppressing the degradation of the 3-methyl-1-butene polymer during melt kneading by the alkyl radical scavenger is exerted by kneading in a low oxygen state compared to the air, for example, in an inert atmosphere.

[0278] According to Example 1 and Comparative Example 7, it is understood that catechols have no effect of suppressing the degradation of 3-methyl-1-butene polymers during melt kneading.

[0279] According to Example 1 and Comparative Example 8, it is understood that nitroxyl radicals have no effect of suppressing the degradation of the 3-methyl-1-butene polymer during melt kneading.

[0280] Comparative Examples 7 and 8 show that catechols and nitroxyl radicals have no stabilizing function, and therefore the effects of the present invention cannot be obtained.

Claims

1. A method for producing a melt-kneaded composition, comprising the step of melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger at 300°C to 380°C and in a low-oxygen state compared to the atmosphere. 2 . The method for producing a melt-kneaded composition according to claim 1 , further comprising the step of injecting an inert gas into the interior of a melt-kneader, wherein the melt-kneading is performed in the melt-kneader. 3 . The method for producing a melt-kneaded composition according to claim 1 , further comprising a step of decompressing and degassing the interior of a melt-kneader, wherein the melt-kneading is performed in the melt-kneader.

4. A method for producing a melt-kneading composition, comprising the step of melt-kneading a 3-methyl-1-butene polymer and an alkyl radical scavenger. The melt kneading is performed at 300°C to 380°C, and The melt-kneading is performed by injecting an inert gas into the interior of the melt-kneading machine, or by decompressing and degassing the interior of the melt-kneading machine.

5. The method for producing a melt-kneaded composition according to any one of claims 1 to 4, wherein The melt kneading is performed for 1 minute to 15 minutes.

6. The method for producing a melt-kneaded composition according to any one of claims 1 to 5, wherein The 3-methyl-1-butene polymer is at least one selected from a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and an α-olefin having 2 to 20 carbon atoms.

7. The method for producing a melt-kneaded composition according to claim 6, wherein: The content ratio of the structural unit derived from the α-olefin in the copolymer exceeds 0 mol % and is 20 mol % or less.

8. The method for producing a melt-kneaded composition according to any one of claims 1 to 7, wherein The alkyl radical scavenger includes at least one selected from acrylic phenol compounds and benzofuranone compounds.

9. The method for producing a melt-kneaded composition according to claim 8, wherein: The acrylic phenol compound is represented by the following general formula (I): In the general formula (I), R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 3 , R 4 , R 5 and R 6 Each independently represents an alkyl group having 1 to 9 carbon atoms.

10. The method for producing a melt-kneaded composition according to claim 8 or 9, wherein: The benzofuranone compound is represented by the following general formula (II): In the general formula (II), R 7 and R 8 Each independently represents an alkyl group having 1 to 4 carbon atoms, R 9 and R 10 Each independently represents an alkyl group having 1 to 9 carbon atoms.

11. The method for producing a melt-kneaded composition according to any one of claims 1 to 10, wherein: The blending amount of the alkyl radical scavenger is 0.01 to 1.00 parts by mass based on 100 parts by mass of the 3-methyl-1-butene polymer.

12. The method for producing a melt-kneaded composition according to any one of claims 1 to 11, wherein In the melt kneading step, The melt-kneading is performed by further adding at least one antioxidant selected from phenolic antioxidants and phosphorus antioxidants. 13 . A melt-kneaded composition produced by the method for producing a melt-kneaded composition according to claim 1 .

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