NL2025363A

NL2025363A - Method of producing polyphenylene ether?based resin composition

Info

Publication number: NL2025363A
Application number: NL2025363A
Authority: NL
Inventors: Yamaguchi Toru
Original assignee: Asahi Chemical Ind
Priority date: 2019-04-19
Filing date: 2020-04-17
Publication date: 2020-10-22
Also published as: JP2020175649A; JP7409900B2; CN111823531A; NL2025363B1

Abstract

Provided ii; a method (If producing a. resin composi— tion, with which the usual generation of degraded products of polyphenylene ether resin inside a barrel of an extrud— er during extrusion and the usual generation of gums around a die nozzle are significantly suppressed, the ex— trusion productivity is improved, and a resin composition having good toughness and reduced contamination with for— eign matters derived from polyphenylene ether can be ob— tained. It is a method of producing a resin composition using an extruder, where the resin composition contains 10 mass%)or more of PPE (A); the extruder is a twin screw ex— truder having a solid transport zone, a melting and knead— ing zone, and a melt transport zone, where 30 96 to 60 96 from an upstream side of the extruder is the solid transport zone, and the remaining 40 96 to 70 96 is the melting' and. kneading zone and. the melt transport zone; when a length of barrels constituting the solid transport zone excluding the barrel provided with the first supply port is 100 96, 75 96 or more of the barrels have a set temperature in a range of 50 °C to 190 °C; barrels consti— tuting the melting and kneading zone and barrels consti— tuting the melt transport zone have a set temperature in a range of 250 °C to 320 °C; and a collecting hopper has an oxygen concentration of 3 vol%)or less.

Description

METHOD OF PRODUCING POLYPHENYLENE ETHER-BASED RESIN COMPOSITION TECHNICAL FIELD

[0001] This disclosure relates to a method of producing a polyphenylene ether-based resin composition.

BACKGROUND

[0002] Polyphenylene ether-based resin compositions are obtained by compounding a polyphenylene ether resin alone, or a polyphenylene ether resin and a styrene- based resin, with a thermoplastic elastomer and additive components such as a flame retardant, a heat stabilizer, a release agent, a lubricant, and inorganic filler, as necessary.

[0003] Polyphenylene ether-based resin compositions are excellent in mechanical properties, electrical properties, acid and alkali resistance, and heat resistance, and have various characteristics such as low specific gravity, low water absorption, and excellent dimensional stability. Therefore, they are widely used as materials for household appliances, electronic office equipment, business machines, information appliances, automobiles, and the like.

[0004] However, polyphenylene ether-based resin compositions usually have a high melt viscosity. Therefore, when an extruder or the like is used to perform melting and kneading to form the resin composition (pellet), the melt-kneaded resin composition comes into contact with oxygen under high temperature conditions, which accelerates the oxidative crosslinking of polyphenylene ether resin. Eventually, the resin gels and carbonizes. When the gelled and carbonized resin is mixed as foreign matters with the resin composition, the appearance, toughness and other properties of a molded product may be deteriorated.

[0005] In addition, during the production of a polyphenylene ether-based resin composition using an extruder, the melt-kneaded resin composition adheres around a circular outlet (die nozzle} at the tip of the extruder where the resin composition is discharged. As the production continues, the adhered matters (gums) are exposed to heat and the outside air for a long time, undergoing oxidative crosslinking and growing like whiskers. They eventually adhere to the extruded resin and get mixed with the resin composition, which may again cause deterioration in the appearance, toughness and other properties of a molded product.

[0006] Further, in the process of collecting and cutting (pelletizing) the resin (strand) continuously discharged in the form of a string from the die nozzle by a cutting machine {(pelletizer), the flow of the strand is unstable due to the presence of grown gums that do not leave the periphery of the die nozzle, and this may cause production troubles such as a broken strand or strand collecting failure by the pelletizer.

[0007] Jp 2012-255046 A (PTL 1) describes a technology for reducing degraded products of polyphenylene ether resin generated inside a barrel of an extruder for a specific polyphenylene ether-based resin composition, which is achieved by adjusting the oxygen concentration inside a first supply port hopper for supplying raw materials of the extruder to 1.0 vol% or less.

JP 2008-274035 A (PTL 2) describes a technology for suppressing thermal degradation of resin and improving impact resistance and heat aging resistance, which is achieved by, when extruding a polyphenylene ether resin composition using an extruder, taking the total length of barrels in the extruder as 100 % and making 45 % to 75 % of the length from the upstream as an unmolten mixing zone.

CITATION LIST Patent Literature

[0008] PTL 1: JP 2012-255046 A PTL 2: JP 2008-274035 A

SUMMARY (Technical Problem)

[0009] However, although the technology described in PTL 1 does reduce degraded products of polyphenylene ether resin generated inside a barrel of an extruder, it may not sufficiently reduce the gums around the die nozzle. In addition, although the technology described in PTL 2 is effective to some extent in reducing the generation of foreign matters inside a barrel of an extruder and in suppressing the deterioration of physical properties of the resin composition, it is insufficient in suppressing the gums during the extrusion.

[0010] It could thus be helpful to provide a method of producing a resin composition, with which the usual generation of degraded products of polyphenylene ether resin inside a barrel of an extruder during extrusion and the usual generation of gums around a die nozzle are significantly suppressed, the extrusion productivity is improved, and a resin composition having good toughness and reduced contamination with foreign matters derived from polyphenylene ether can be obtained. (Solution to Problem)

[0011] After intensive studies, we found that, by extruding a resin composition, which contains a certain amount or more of polyphenylene ether, with a specific extrusion method using an extruder, it is possible to significantly suppress the generation of degraded products of polyphenylene ether resin inside a barrel of an extruder during the extrusion and the generation of gums around a die nozzle and improve the extrusion productivity, and to stably produce a polyphenylene ether-based resin composition having good toughness and reduced contamination with foreign matters derived from polyphenylene ether. We thereby completed the present disclosure.

[0012] The primary features of the present disclosure are as follows.

[1] A method of producing a resin composition using an extruder, wherein the resin composition contains 10 mass% or more of polyphenylene ether (A) with respect to a total amount of the resin composition which is 100 mass%, the extruder 1s a twin screw extruder having a solid transport zone, a melting and kneading zone, and a melt transport zone, where the solid transport zone has a barrel provided with a first supply port, when a length of all barrels in the extruder is 100 %, 30 % to 60 % from an upstream side of the extruder is the solid transport zone, and the remaining 40 % to 70 % is the melting and kneading zone and the melt transport zone, when a length of barrels constituting the solid transport zone excluding the barrel provided with the first supply port is 100 %, 75 % or more of the barrels have a set temperature in a range of 50 °C to 190 °C, barrels constituting the melting and kneading zone and barrels constituting the melt transport zone have a set temperature in a range of 250 °C to 320 °C, and a collecting hopper provided above the first supply port has an oxygen concentration of 3 vol% or less.

[2] The method of producing a resin composition according to [1], wherein, when a length of barrels constituting the solid transport zone excluding the 5 barrel provided with the first supply port is 100 %, 100 % of the barrels have a set temperature in a range of 50 °C to 190 °C.

[3] The method of producing a resin composition according to [1] or [2], wherein the melt transport zone has a barrel provided with an opening, and a vent port having a nitrogen injection line and a gas vent is provided above the opening.

[4] The method of producing a resin composition according to any one of [1] to [3], wherein all raw materials for extrusion are supplied from the first supply port.

[5] The method of producing a resin composition according to any one of [1] to [4], wherein the resin composition further contains 5 mass% to 80 mass% of a styrene-based resin (B) with respect to the total amount of the resin composition which is 100 mass%.

[6] The method of producing a resin composition according to any one of [1] to [5], wherein the resin composition further contains 0.1 mass% to 25 mass% of a styrene-based thermoplastic elastomer {C) with respect to the total amount of the resin composition which is 100 mass%.

[7] The method of producing a resin composition according to any one of [1] to [6], wherein the resin composition further contains 0.001 mass% to 3 mass% of an antioxidant (DPD) with respect to the total amount of the resin composition which is 100 mass%.

[8] The method of producing a resin composition according to any one of [1] to [7], wherein in the resin composition, a content of a polyolefin-based resin component is 5 mass% or less with respect to the total amount of the resin composition which is 100 mass%.

(Advantageous Effect)

[0013] According to the production method of the present disclosure, it is possible to significantly suppress the usual generation of degraded products of polyphenylene ether resin inside a barrel of an extruder during extrusion and the usual generation of gums around a die nozzle and improve the extrusion productivity, and to stably obtain a resin composition having good toughness and reduced contamination with foreign matters derived from polyphenylene ether.

DETAILED DESCRIPTION

[0014] The following provides a detailed description of an embodiment of the present disclosure (hereinafter, referred to as the “present embodiment”). However, the present disclosure is not limited to the following embodiment and may be implemented with various alterations that are within the essential scope thereof.

[0015] The method of producing a polyphenylene ether- based resin composition of the present embodiment is a method of producing a resin composition using an extruder, where the resin composition contains 10 mass% or more of polyphenylene ether (A) with respect to a total amount of the resin composition which is 100 mass%; the extruder is a twin screw extruder having a solid transport zone, a melting and kneading zone, and a melt transport zone, where the solid transport zone has a barrel provided with a first supply port; when a length of all barrels in the extruder is 100 %, 30 %

to 60 % from an upstream side of the extruder is the solid transport zone, and the remaining 40 % to 70 % is the melting and kneading zone and the melt transport zone; when a length of barrels constituting the solid transport zone excluding the barrel provided with the first supply port is 100 %, 75 % or more of the barrels have a set temperature in a range of 50 °C to 190 °C; barrels constituting the melting and kneading zone and barrels constituting the melt transport zone have a set temperature in a range of 250 °C to 320 °C; and a collecting hopper provided above the first supply port has an oxygen concentration of 3 vol% or less.

[0016] <<Resin composition>> The resin composition of the present embodiment contains 10 mass% or more of polyphenylene ether (A) with respect to the total amount of the resin composition (100 mass%) .

[0017] The polyphenylene ether-based resin composition of the present embodiment is produced by melting and kneading the component (A) and, if necessary, the components (B) to (D) of the present application, and other components added as necessary with the production method of the present embodiment described later.

[0018] We found that, when the above resin composition is extruded with a specific extrusion method, the generation of oxidized cross-linked products of polyphenylene ether resin inside a barrel of an extruder during the extrusion and the generation of gums around a die nozzle are significantly suppressed, the extrusion productivity is improved, and the contamination with foreign matters derived from polyphenylene ether is reduced. The following provides a detailed description of the components of the resin composition.

[0019] <Polyphenylene ether (A)>

The polyphenylene ether (A) is preferably a homopolymer or a copolymer having a repeating unit of [a] and/or [b] of the general formula (1).

R, R, (1) [a] R, R, RR, (1) [Db] In the [a] and [b] of the formula (1), it is pref- erable that R:, Rs, Ry, Rs, Rs and Rs each independently represent a monovalent residue selected from the group consisting of an alkyl group having 1 to 4 carbon at- oms, an aryl group having 6 to 12 carbon atoms, a halo- gen atom, and a hydrogen atom.

Note that Rs and Rg should not simultaneously be hydrogen.

It is more preferably that the alkyl group have 1 to 3 carbon atoms and the aryl group have 6 to 8 carbon atoms. Among the monovalent residues, hydrogen is more preferable.

The number of repeating units in the [a] and [b] of the (1) is not particularly limited, because it var- ies depending on the molecular weight distribution of the polyphenylene ether (A).

[0020] Examples of the polyphenylene ether homopoly- mer include, but are not limited to, poly{(2,6-dimethyl- 1,4-phenylene) ether, poly (Z2-methyl-6-ethyl-1,4- phenylene) ether, poly (2, 6-diethyl-1, 4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene)} ether, poly (2, 6~di-n~-propyl~-1,4~-phenylene) ether, poly (2- methyl-6-n-butyl-1,4-phenylene) ether, poly{2-ethyl-6- isopropyl-1,4-phenylene) ether, poly{2-methyl-6- chloroethyl-1,4-phenylene)}) ether, poly{2-methyl-6- hydroxyethyl-1, 4-phenylene) ether, and poly{2-methyl-6- chloroethyl-1,4-phenylene) ether.

[0021] Examples of the polyphenylene ether copolymer include, but are not limited to, those mainly based on a polyphenylene ether structure such as a copolymer of 2, 6-dimethylphenol and 2,3, 6-trimethylphenol, a copoly- mer of 2,6-dimethylphenol and o-crescl, and a copolymer of 2,3,6~trimethylphencl and o-cresol.

[0022] Among polyphenylene ether, it is preferable to use poly (2, 6-dimethyl-1,4-phenylene}) ether.

[0023] The above-mentioned polyphenylene ether (A) may be used alone or in combination of two or more.

[0024] In addition, the polyphenylene ether (A) may contain various phenylene ether units other than the [a] and [b] of the formula (l) as a partial structure.

Examples of the phenylene ether unit include, but are not limited to, a 2-(dialkylaminomethyl)-6- methylphenylene ether unit and a 2-{N-alkyl-N- phenylaminomethyl) ~-6-methylphenylene ether unit de- scribed in JP H01-297428 A and JP S63-301222 A.

[0025] In addition, the polyphenylene ether (A) may contain a structural unit other than a phenylene ether unit in the main chain. Examples of such a structural unit include a unit derived from diphenoguinone. However, the structural unit contained in the main chain other than the phe- nylene ether unit is preferably 20 mass% or less, more preferably 10 mass% or less, and still more preferably 5 mass% or less, with respect to 100 mass% of the pol- yphenylene ether (A).

[0026] Further, the polyphenylene ether (A) may be functionalized polyphenylene ether obtained by reacting (modifying) a part or all of polyphenylene ether with a functionalizing agent containing at least one selected from the group consisting of carboxylic acids, acid an- hydrides, acid amides, imides, amines, ortho esters, hydroxy, and ammonium carboxylates.

[0027] The reduced viscosity of the polyphenylene ether (A) used in the present embodiment is preferably in the range of 0.25 dL/g to 0.60 dL/g, more preferably in the range of 0.30 dL/g to 0.55 dL/g, and still more preferably in the range of 0.35 dL/g to 0.50 dL/g. It is preferably 0.25 dL/g or more from the viewpoint of obtaining sufficient mechanical properties and is pref- erably 0.55 dL/g or less from the viewpoint of molda- bility and workability and the brightness of a molded product. The reduced viscosity in the present embodiment is a value obtained by measuring with an Ubbelohde viscom- eter at 30 °C in a chloroform solvent at a concentration of 0.50 g/dL.

[0028] The ratio (Mw/Mn value) between the weight- average molecular weight Mw and the number-average mo-

lecular weight Mn of the polyphenylene ether (A) used in the present embodiment (which is in the form of a polymer powder) before heat processing such as extru- sion is preferably 1.2 to 3.0, more preferably 1.5 to

2.5, and still more preferably 1.8 to 2.3. The Mw/Mn value is preferably 1.2 or more from the viewpoint of the moldability and workability of the resin composi- tion, and the Mw/Mn value is preferably 3.0 or less from the viewpoint of the mechanical properties of the resin composition, particularly from the viewpoint of maintaining the tensile strength.

The weight-average molecular weight Mw and the number-average molecular weight Mn are obtained from the molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

[0029] In the polyphenylene ether-based resin compo- sition of the present embodiment, the content of the polyphenylene ether (A) is 10 mass% or more of the to- tal of the resin composition. The content is prefera- bly 20 mass% or more, more preferably 30 mass% or more, and still more preferably 50 mass% or more. It is important to have a content of 10 mass% or more from the viewpoint of sufficiently exhibiting the effects of the production method of the present embodiment.

[0030] <Styrene-based resin component (B)> The resin composition of the present embodiment may contain a styrene-based resin (B) mainly for the purpose of improving molding fluidity.

In the present embodiment, the styrene-based resin (B) refers to a homopolymer of a styrene-based compound or a copolymer of a styrene-based compound and a com- pound that is copolymerizable with a styrene-based com- pound (excluding a conjugated diene compound). The component (B) does not include those included in the category of the component (C) described later.

Specific examples of the styrene-based resin (B) include styrene, a-methylstyrene, 2,4-dimethylstyrene, monochlorostyrene, p-methylstyrene, p-tert- butylstyrene, and ethylstyrene.

[0031] Examples of the compound that is copolymeriza- ble with a styrene-based compound include methacrylic acid esters such as methyl methacrylate and ethyl meth- acrylate; unsaturated nitrile compounds such as acrylo- nitrile and methacrylonitrile; and acid anhydrides such as maleic anhydride.

[0032] The styrene-based resin (B) may be obtained by polymerizing a styrene-based compound, or a styrene- based compound and a compound that is copolymerizable with a styrene-based compound in the presence or ab- sence of a rubbery polymer.

Examples of the rubbery polymer include a conju- gated diene-based rubber, a copolymer of a conjugated diene and an aromatic vinyl compound, a hydrogenated product thereof, and an ethylene-propylene copolymer- based rubber.

[0033] In the present embodiment, the styrene-based resin (B) is preferably polystyrene or high-impact pol- ystyrene reinforced with a rubbery polymer, and the styrene-based resin (B) is more preferably polystyrene.

[0034] The content of the styrene-based resin (B) in the resin composition used in the present embodiment is preferably 5 mass% to 80 mass%, more preferably 10 mass% to 60 mass%, still more preferably 20 mass% to 60 mass%, and particularly preferably 25 mass% to 45 mass%, in 100 mass% of the resin composition. The content is preferably 5 mass% or more from the view-

point of obtaining sufficient molding fluidity, and the content is preferably 80 mass% or less from the view- point of maintaining sufficient heat resistance.

[0035] <Styrene-based thermoplastic elastomer (C)> The styrene-based thermoplastic elastomer (C) used in the present embodiment is a block copolymer having a styrene block and a conjugated diene compound block.

[0036] The conjugated diene compound block is prefer- ably a hydrogenated one whose hydrogenation rate is at least 50 % or more from the viewpoint of thermal sta- bility. The hydrogenation rate 1s more preferably 80 % or more and still more preferably 95 % or more.

[0037] Examples of the conjugated diene compound block include, but are not limited to, polybutadiene, polyisoprene, poly {ethylene-butylene), poly (ethylene- propylene), and vinyl-polyisoprene. The above- mentioned conjugated diene compound block may be used alone or in combination of two or more.

[0038] The type of arrangement of the repeating units constituting the block copolymer may be a linear type or a radial type. In addition, polystyrene blocks and rubber intermediate blocks may form a two, three, or four block structure. Among such block copolymers, a triblock linear-type block copolymer formed by a poly- styrene-poly{(ethylene-butylene) polystyrene structure is preferable from the viewpoint of sufficiently exhib- iting the effects desired in the present embodiment. The conjugated diene compound block may contain a buta- diene unit in a range not exceeding 30 mass.

[0039] In the composition of the present embodiment, the styrene-based thermoplastic elastomer may be a functionalized styrene-based thermoplastic elastomer obtained by introducing a functional group such as a carbonyl group or an amino group.

[0040] The bound styrene content of the styrene-based thermoplastic elastomer (C) of the present embodiment is in the range of 20 mass% to 90 mass%, preferably in the range of 55 mass% to 80 mass%, and more preferably in the range of 60 mass% to 70 mass%. The content is preferably 20 mass% or more from the viewpoint of the miscibility with the components (A) and (B), and the content is preferably 90 mass% or less from the view- point of obtaining sufficient impact resistance.

[0041] The number-average molecular weight Mn of the styrene-based thermoplastic elastomer {C) of the pre- sent embodiment is preferably in the range of 30,000 to 500,000, more preferably in the range of 40,000 to 300,000, and still more preferably in the range of 45,000 to 250,000. It is preferably in the range 30,000 to 500,000 from the viewpoint of obtaining suf- ficient toughness in a molded product.

The Mw/Mn value of the component (C), which is de- termined from the weight-average molecular weight Mw and the number-average molecular weight Mn obtained from the molecular weight in terms of polystyrene, is preferably in the range of 1.0 to 3.0, more preferably in the range of 1.0 to 2.0, and still more preferably in the range of 1.0 to 1.5. It is preferably in the range of 1.0 to 3.0 from the viewpoint of mechanical properties.

[0042] The content of the styrene-based thermoplastic elastomer (C) of the present embodiment is preferably in the range of 0.1 mass% to 25 mass%, more preferably in the range of 0.5 mass% to 20 mass%, and still more preferably in the range of 1 mass% to 20 mass%, in 100 mass% of the resin composition. The content is prefer- ably 0.1 mass% or more from the viewpoint of toughness improvement, and the content is preferably 25 mass% or less from the viewpoint of the mechanical properties of a molded product.

[0043] <Antioxidant (D)> The resin composition of the present embodiment may further contain an antioxidant (D).

[0044] The antioxidant (D) may be either a primary antioxidant that functions as a radical chain inhibitor or a secondary antioxidant that has an effect of decom- posing peroxides. In other words, through the use of an antioxidant, radicals that may arise at terminal me- thyl groups or side chain methyl groups when the poly- phenylene ether is exposed to high temperature for a long time can be captured (primary antioxidant) or per- oxides that arise at terminal methyl groups or side chain methyl groups due to the above-mentioned radicals can be broken down (secondary antioxidant). Conse- quently, oxidative crosslinking of the polyphenylene ether can be prevented.

[0045] Hindered phenol-based antioxidants may be mainly used as the primary antioxidant, and specific examples thereof include 2,6-di-t-butyl-4-methylphenol, pentaerythritol tetrakis[3-(3,5-di-t-butyl-4- hydroxyphenyl) propionate], n-octadecyl-3-{3,5-di-t- butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4- methyl-6-t-butylphenol), 2-t-butyl-6-(3-t-butyl-2- hydroxy~b-methylbenzyl)-4-methylphenyl acrylate, 2-[1- (2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t- pentylphenyl acrylate, 4,4'-butylidenebis (3-methyl-6-t- butylphenol), alkylated bisphenol, tetrakis[methylene- 3-{3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane,

and 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)- propionyloxy}-1, l-dimethylethyl]-2,4,8,10~ tetraoxyspirol[5, 5]lundecane.

[0046] Phosphoric antioxidant may be mainly used as the secondary antioxidant. Specific examples of the phosphoric antioxidant include trisnonylphenyl phos- phite, triphenyl phosphite, tris (2,4-di-t- butylphenyl) phosphite, bis{(2,4-di-t- butylphenyl)pentaerythritol-di-phosphite, bis(2,6-di-t- butyl-4-methylphenvl)pentaervthritol-di-phosphite, and 3, 9-bis{2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10- tetraoxa-3, 9S-diphosphaspiro[5,5]lundecane.

[0047] Other antioxidants including metal oxides such as zinc oxide and magnesium oxide and metal sulfides such as zinc sulfide can be used in combination with the above-mentioned antioxidant.

[0048] Among these, in order to improve the toughness and the mechanical properties after long-term high- temperature exposure of a molded product, it is prefer- ably a phosphoric antioxidant which is a secondary an- tioxidant, more preferably a phosphite-based antioxi- dant, and particularly preferably a phosphite-based an- tioxidant having the structure of the following chemi- cal formula (2) in molecules. 0o © Ee eG ze 0 O (2)

[0049] The content of the antioxidant (D) is prefera- bly 0.001 mass% to 3 mass%, more preferably 0.01 mass% to 2 mass%, still more preferably 0.1 mass% to 1 mass%, and particularly preferably 0.1 mass% to 0.5 mass%, with respect to 100 mass% of the resin composi- tion. The content is preferably 0.001 mass% or more from the viewpoint of suppressing the oxidation deteri- oration of resin during the extrusion molding, and the content is preferably 3 mass% or less from the view- point of maintaining the surface appearance of a molded product.

[0050] <Other components» In the case of coloring the resin composition of the present embodiment, it is preferable to contain colorants composed of carbon black, titanium oxide, other known inorganic and organic dyes, pigments, etc. in the range of 0.001 mass% to 5 mass%, in 100 mass% of the resin composition. The content is preferably

0.001 mass% or more from the viewpoint of sufficient coloring, and the content is preferably 5 mass% or less from the viewpoint of obtaining sufficient mechanical strength in a molded product, maintaining a good ap- pearance, and the like.

[0051] In the resin composition of the present embod- iment, the content of a polyolefin-based resin compo- nent is preferably 5 mass% or less in 100 mass% of the resin composition.

Examples of the polyolefin-based resin component include polyolefin resins such as polyethylene and pol- ypropylene, and polyolefin-based copolymers such as ethylene-propylene copolymer, ethylene-octene copoly- mer, ethylene-ethyl acrylate copolymer, and ethylene- ethyl methacrylate copolymer.

The content of the polyolefin-based resin compo- nent in the resin composition of the present embodiment is more preferably 3 mass% or less, and still more preferably 1 mass% or less. The content is preferably of 5 mass% or less from the viewpoint of suppressing the deterioration of physical properties and the dete- rioration of appearance of a molded product due to sur- face layer peeling or the like.

[0052] The resin composition of the present embodi- ment preferably does not contain any inorganic filler as a reinforcement agent from the viewpoint of the toughness and appearance of a molded product. Inorgan- ic filler as a reinforcing agent is generally used for reinforcing a thermoplastic resin, and examples thereof include glass fiber, carbon fiber, glass flake, talc, and mica. Containing no inorganic filler here means that the content of the inorganic filler is 1 mass% or less in 100 mass% of the resin composition. The con- tent is preferably 0.5 mass% or less and more prefera- bly 0.1 mass% or less.

[0053] The resin composition of the present embodi- ment may be also added with, if necessary, an ultravio- let absorber, a release agent, a lubricant, and other components within a range in which the effects of the present embodiment would not be significantly reduced.

[0054] <<Method of producing resin composition >> The resin composition of the present embodiment is produced by melting and kneading the component (A) and, if necessary, the components (B) to (D) of the present application, and other components added as necessary, as described below.

[0055] We found a production method, where, by ex- truding the above-described resin composition with a specific extrusion method, the generation of degraded products of polyphenylene ether resin in a barrel of an extruder during the extrusion and the generation of gums around a die nozzle are significantly suppressed, the extrusion productivity is improved, and a polyphe- nylene ether-based resin composition having good tough- ness and reduced contamination with foreign matters de- rived from polyphenylene ether can be stably mass- produced.

[0056] The following provides a detailed description of the method of producing a resin composition.

[0057] The polyphenylene ether-based resin composi- tion of the present embodiment is produced by melting and kneading the component (A) and, if necessary, the components (B) to (D), and other components added as necessary in a twin screw extruder having a solid transport zone, a melting and kneading zone, and a melt transport zone in barrels.

[0058] When a length of all barrels in the extruder is 100 %, 30 % to 60 % from an upstream side of the extruder is the solid transport zone, and the remaining 40 % to 70 % is the melting and kneading zone and the melt transport zone. In addition, when a length of barrels constituting the solid transport zone excluding a barrel provided with a first supply port is 100 %, 75 % or more of the barrels have a set temperature in a range of 50 °C to 190 °C; barrels of the melting and kneading zone and barrels of the melt transport zone have a set temperature in a range of 250 °C to 320 °C; and a collecting hopper provided above the first supply port has an oxygen concentration of 3 vol% or less. The melting and kneading are performed under these con- ditions to produce a resin composition.

[0059] From the viewpoint of stably obtaining a large amount of resin composition that can sufficiently ex- hibit the desired effects of the present embodiment, it is preferable to use a twin screw extruder having a screw diameter of 40 mm to 90 mm during the production of the resin composition.

Preferable examples include a method of using a TEM58SS twin screw extruder (made by Toshiba Machine Co., Ltd., barrels: 13 (including the barrel below a first supply port hopper), screw diameter: 58 mm, L/D = 53; at a screw pattern that kneading discs L: 2, knead- ing discs R: 12 and kneading discs N: 4) and performing melting and kneading under conditions where, when the length of all barrels in the extruder (including a bar- rel provided with a hopper at a first supply port) is 100 %, the length of barrels of the solid transport zone is 45 %, and the length of barrels of the remain- ing melting and kneading zone and melt transport zone is 55 %; the barrels of the solid transport zone (ex- cluding the barrel below the first supply port hopper for water cooling) have a set temperature of 100 °C to 180 °C, and the barrels of the melting and kneading zone and the melt transport zone have a set temperature of 270 °C to 310 °C; the oxygen concentration inside a col- lecting hopper above the first supply port is 0.3 vol% to 2.0 vol%; the screw rotation speed is 350 rpm to 600 rpm; and the extrusion rate is 350 kg/h to 600 kg/h.

[0060] During the production of the resin composi- tion, the solid transport zone in the barrels of the twin screw extruder refers to a zone where the raw ma- terial components for extrusion, which are not com- pletely molten and are in a incompletely molten state or a semi-molten state where the raw material compo- nents for extrusion contain unmolten components, are transported only by a feed screw element configuration of a right-handed screw that is single-threaded and/or double-threaded.

[0061] When the length of all barrels in the extruder is 100 %, the length of the solid transport zone in the extruder is in the range of 30 % to 60 % of the length. It is preferably in the range of 35 % to 60 %, more preferably in the range of 40 % to 55 %, and still more preferably in the range of 45 % to 55 %. It should be 30 % or more from the viewpoint of suffi- ciently suppressing the thermal degradation of the pol- yphenylene ether resin, and it should be 60 % or less from the viewpoint of sufficiently melting and kneading the raw material components for extrusion and from the viewpoint of production stability.

[0062] The melting and kneading zone in the barrels of the twin screw extruder is a zone where the incom- pletely molten or semi-molten raw material components for extrusion sent from the solid transport zone are literally molten and kneaded, and refers to a zone hav- ing a screw configuration including a plurality of kneading screw elements such as kneading discs R, kneading discs N and kneading discs L. The melt transport zone in the barrels of the twin screw extruder is a zone for transporting the raw mate- rial components for extrusion sent from the melting and kneading zone to a resin outlet (die nozzle) of the ex- truder, and refers to a zone in which the molten raw material components for extrusion is transported only by a feed screw element configuration of a right-handed screw that is single-threaded and/or double-threaded.

[0063] When the length of all barrels in the extruder is 100 %, the total length of the melting and kneading zone and the melt transport zone in the extruder is in the range of 70 % to 40 % of the length. It is pref- erably in the range of 60 % to 40 %, more preferably in the range of 57 % to 40 %, and still more prefera- bly in the range of 57 % to 45 ©. It should be 70 % or less from the viewpoint of sufficiently suppressing the thermal degradation of the polyphenylene ether res- in, and it should be 40 % or less from the viewpoint of sufficiently melting and kneading the raw material com- ponents for extrusion.

[0064] When the length of all barrels in the extruder is 100 %, the length of the melting and kneading zone in the extruder is preferably in the range of 15 % to 40 % of the length. It is more preferably in the range of 20 % to 40 %, and still more preferably in the range of 22 % to 35 %. It is preferably 15 % or more from the viewpoint of sufficiently melting and kneading the resin components for extrusion, and it is prefera- bly 40 % or less from the viewpoint of suppressing the thermal degradation of the polyphenylene ether resin.

[0065] With respect to the set temperature of barrels of the solid transport zone in the extruder, when a length of barrels constituting the solid transport zone excluding the barrel provided with the first supply port is 100 %, 75 % or more, preferably 80 % or more,

more preferably 90 % or more, and still more preferably 100 % of the barrels have a set temperature in a range of 50 °C to 190 °C. The set temperature is preferably in the range of 70 °C to 190 °C, more preferably in the range of 100 °C to 180 °C, and still more preferably in the range of 130 °C to 170 °C. It should be 50 °C or higher from the viewpoint of production stability, and it should be 190 °C or lower from the viewpoint of sup- pressing the thermal degradation of the polyphenylene ether resin.

[0066] The set temperature of barrels of the melting and kneading zone and the melt transport zone in the extruder 1s in the range of 250 °C to 320 °C. It is preferably in the range of 260 °C to 320 °C, and more preferably in the range of 270 °C to 310 °C. It should be 250 °C or higher from the viewpoint of sufficiently melting and kneading the resin components for extrusion and the viewpoint of production stability, and it should be 329 °C or lower from the viewpoint of sup- pressing the thermal degradation of the polyphenylene ether resin and the viewpoint of production stability.

[0067] The set temperature of the resin outlet (die head) in the extruder is preferably in the range of 270 °C to 320 °C. It is more preferably in the range of 290 °C to 315 °C, and still more preferably in the range of 300 °C to 310 °C. It is preferably 270 °C or higher from the viewpoint of production stability, and it is preferably 320 °C or lower from the viewpoint of sup- pressing the thermal degradation of the polyphenylene ether resin.

[0068] During the production of the resin composition used in the present embodiment using a twin screw ex- truder, attention should be paid to the fact that con- tamination with gels or carbide generated due to the oxidation deterioration of polyphenylene ether, which is the component (A), in extruded resin pellets will cause the deterioration of the physical properties of a molded product such as the deterioration of the surface appearance or the toughness. Therefore, it is important that the component (A) be charged from a most upstream (top feed) raw material inlet, and that the oxygen concentration inside a col- lecting hopper at the most upstream inlet be set to 3 vol% or less. The oxygen concentration inside the col- lecting hopper is preferably 2 vol% or less, more pref- erably 1 vol% or less, and still more preferably 0.5 vol®% or less.

[0069] The oxygen concentration can be adjusted by sufficiently replacing the gas inside the raw material storage hopper with nitrogen, sealing the feed piping from the raw material storage hopper to the raw materi- al inlet of the extruder to prevent air from going in and out of the feed piping, and then adjusting the feeding amount of nitrogen and the degree of opening of a gas vent.

[0070] During the production of the resin composition of the present embodiment, it is preferable that all of the raw materials for extrusion be supplied from the first supply port (top feed) from the viewpoint of suf- ficiently reducing the oxygen concentration inside the collecting hopper at the most upstream inlet and from the viewpoint of suppressing the oxidation deteriora- tion of the component (A) and sufficiently exhibiting the effects desired in the application of the present disclosure.

[0071] The measurement of the oxygen concentration inside the collecting hopper is performed using an oxi- meter, where a sensor portion of the oximeter is ar- ranged in the middle part inside the collecting hopper, so that the measurement can be always performed during the extrusion.

[0072] In addition, when the molten resin extruded from the die nozzle of the extruder comes into contact with air, the molten resin adhered to the edge of the nozzle may be deteriorated due to oxidative crosslink- ing, causing the generation and growth of gums. As the production continues over a long period of time, it grows on the edge of the nozzle, and eventually gets mixed with the resin and deteriorates the appearance and physical properties of a product. Therefore, it is preferable to blow nitrogen gas against the resin imme- diately out of the die nozzle. The nitrogen gas blow may be performed by connecting a known gum-removing ap- paratus with a nitrogen gas line.

[0073] The amount of nitrogen gas blown to the die nozzle is preferably in the range of 1 L/min to 50 L/min, more preferably in the range of 5 L/min to 30 L/min, and still more preferably in the range of 10 L/min to 25 L/min. It is preferably 1 L/min or more from the viewpoint of providing adequate contacts be- tween the resin and the nitrogen gas, and it is prefer- ably 50 L/min or less from the viewpoint of considera- tion of the surrounding environment.

[0074] It is usually desirable to perform decompres- sion and devolatilization with a vacuum vent to remove residual volatile matters in the raw material compo- nents during the extrusion. However, in this case, the outside air may be sucked from a slight space between the joints of the barrels to the inside of the vacuum vent and the barrels around the wvacuum vent, which may accelerate the deterioration of the resin due to the oxidative crosslinking of the molten resin. In this case, it may be preferable to perform extrusion without decompression or devolatilization with a vacuum vent. When the vacuum vent is removed and the top of the bar- rel is plugged, the gas generated from the molten resin during the extrusion raises the internal pressure of the barrel. As a result, the discharge of molten resin from the die nozzle becomes unstable, rendering it dif- ficult to collect the strand during the extrusion. Therefore, it is preferable to provide an opening above the barrel, arrange a vent port having a nitrogen in- jection line and a gas vent in the opening, inject ni- trogen from the nitrogen injection line into the vent pert to blow nitrogen against the molten resin at the vent opening, and performing the extrusion while dis- charging the gas component generated from the molten resin and the nitrogen gas from the gas vent. {0075] The flow rate of the nitrogen gas injected in- to the vent port is preferably in the range of 1 L/min to 50 L/min, more preferably in the range of 5 L/min to 30 L/min, and still more preferably in the range of 10 L/min to 25 L/min. It is preferably 1 L/min or more from the viewpoint of providing adequate contacts be- tween the resin and the nitrogen gas, and it is prefer- ably 50 L/min or less from the viewpoint of considera- tion of the surrounding environment.

[0076] In the production of the resin composition of the present embodiment, the screw rotation speed of the twin screw extruder is preferably in the range of 250 rpm to 700 rpm. It is more preferably in the range of 300 rpm to 600 rpm, still more preferably in the range of 350 rpm to 600 rpm, and particularly preferably in the range of 400 rpm to 500 rpm. It is preferably 250 rpm or more from the viewpoint of sufficiently melting and kneading the resin composition, and it is prefera- bly 700 rpm or less from the viewpoint of suppressing the thermal degradation due to the shear heating of the resin composition.

[0077] During the production of the resin composition of the present embodiment, the extrusion rate of the twin screw extruder is preferably in the range of 250 kg/h to 700 kg/h. It is more preferably in the range of 300 kg/h to 600 kg/h, still more preferably in the range of 350 kg/h to 500 kg/h, and particularly prefer- ably in the range of 350 kg/h to 450 kg/h. It is pref- erably 250 kg/h or more from the viewpoint of obtaining sufficient mass productivity, and it is preferably 700 kg/h or less from the viewpoint of production stabil- ity.

[0078] [Molded product] The molded product of the present embodiment con- taining polyphenylene ether-based resin composition can be obtained by subjecting the resin composition ob- tained with the above-described production method to molding. Preferable examples of the method of molding the resin composition include, but are not limited to, in- jection molding, extrusion molding, vacuum molding, and pressure molding. Injection molding is more preferable particularly from the viewpoint of molding appearance.

[0079] The molding temperature during the molding of the resin composition is preferably in the range of 250 °C to 340 °C, which is the highest set temperature range of the barrel, more preferably in the range of 270 °C to 330 °C, and still more preferably in the range of 280 °C to 320 °C. The molding temperature is preferably 250 °C or higher from the viewpoint of obtaining sufficient moldability and workability, and the molding tempera- ture is preferably 340 °C or lower from the viewpoint of suppressing the thermal degradation of the resin and maintaining the physical properties.

[0080] The mold temperature during the molding of the resin composition is preferably in the range of 40 °C to 150 °C, more preferably in the range of 80 °C to 140 °C, and still more preferably in the range of 80 °C to 120 °C. The mold temperature is preferably 40 °C or higher from the viewpoint of sufficiently maintaining the ap- pearance of a molded product, and the mold temperature is preferably 150 °C or lower from the viewpoint of molding stability.

[0081] According to the production method of the pre- sent embodiment, it is possible to significantly sup- press the generation of degraded products of polyphe- nylene ether resin in a barrel of an extruder during extrusion and the generation of gums around a die noz- zle, improve the extrusion productivity, and stably mass-produce a polyphenylene ether-based resin composi- tion having good toughness and reduced contamination with foreign matters derived from polyphenylene ether. Therefore, preferable examples of the molded product of the present embodiment include household appliance and electronic office equipment members, electrical and electronic equipment, automotive applications, various industrial products, and the like.

EXAMPLES

[0082] The following provides a more detailed de- scription of the present embodiment through examples and comparative examples. However, the present embodi- ment is not limited to only these examples.

[0083] Methods of evaluating and measuring physical properties and raw materials used in the examples and comparative examples are as follows.

[0084] [Production stability]

1. Gums When the resin compositions of the following exam- ples and comparative examples were melt-kneaded and produced under the extrusion conditions described later using a TEM58SS twin screw extruder (made by Toshiba Machine Co., Ltd., barrels: 12 (excluding the barrel below a first supply port hopper), screw diameter: 58 mm, L/D = 53), the presence or absence of gums (which were generated when the molten resin adhered to the edge of the die nozzle and grew into a needle shape ) was confirmed.

After the operation continued for two hours, a sample in which no gums were visually observed was evaluated as “excellent”, and a sample in which gums were visually observed in the two hours was evaluated as “poor”. The evaluation criterion is that those evaluated as “excellent” are suitable for the produc- tion method of the present disclosure.

[0085] 2. Stability of collecting strand During the extrusion of resin composition in the above “1. Gums”, after the operation continued for two hours, a sample in which the strand was stably collect- ed was evaluated as “excellent”, a sample in which the strand broke for 2 times or less during the two hours was evaluated as “fair”, and a sample in which the strand broke for 3 times or more during the two hours was evaluated as “poor”. The evaluation criterion is that those evaluated as “excellent” are suitable for the production method of the present disclosure.

[0086] [Evaluation of physical properties]

3. Toughness (tensile strength and tensile elongation) Pellets of the resin compositions of the examples and comparative examples obtained by the extrusion in the above “1. Gums” were dried in a hot-air dryer at 100 °C for two hours. The dried resin composition was molded into an IS03167 dumbbell molded piece of multi- purpose test specimen A type with an injection molding machine with a mold for ISO physical property specimen attached thereto (IS-80EPN, made by Toshiba Machine Co., Ltd.), where the cylinder temperature was 320 °C, the mold temperature was 80 °C, the injection pressure was 50 MPa (gauge pressure), the injection speed was 200 mm/sec, and the injection time/cooling time was 20 sec/20 sec. The obtained dumbbell molded pieces were left at 23 °C for 24 hours, and then the tensile strength and the tensile elongation (nominal tensile strain) of five pieces were measured at 23 °C and under the condition of a tensile test speed of 5 mm/min in accordance with IS0527 and the average value was deter- mined. The evaluation criteria were as follows: a high tensile strength means excellent mechanical strength, and a high tensile elongation means excellent tough- ness; and a sample having a high tensile strength and a high tensile elongation means that the oxidation dete- rioration of the resin composition was suppressed and the contamination with foreign matters was reduced.

[0087] 4. Thermal stability (tensile strength reten- tion after aging) The ISO dumbbell molded pieces of the resin compo sitions of Examples 1 to 12 and Comparative Examples 1 to 6 obtained through the molding in the above “3. Toughness (tensile strength and tensile elongation)” were subjected to aging in a hot-air oven at 140 °C for 1000 hours, and then left at 23 °C for 24 hours. Subse~ quently, the tensile strength of five pieces were meas- ured at 23 °C and under the condition of a tensile test speed of 5 mm/min in accordance with 180527, and the average value was determined. Further, taking the ten- sile strength before aging as 100 %, the retention % of the value of the tensile strength after aging was calculated. High retention of tensile strength after aging means that the oxidation deterioration of the resin composition inside a barrel of an extruder was suppressed and the contamination with foreign matters was reduced.

[0088] [Raw materials] <Polyphenylene ether (A)> (A-1) Poly{(2,6-dimethyl-1, 4-phenylene) ether having a reduced viscosity of 0.50 dL/g (measured with an Ub- belohde viscometer at 30 °C in a chloroform solvent of

0.5 g/dL).

<Styrene-based resin (B)> (B-1) General purpose polystyrene (product name: Poly- styrene 685® (Polystyrene 685 is a registered trademark in Japan, other countries, or both), produced by PS Ja- pan Corporation). This is polystyrene containing no rubber component, that is, polystyrene not reinforced with a rubber.

<Styrene-based thermoplastic elastomer (C)> (C-1) Three-block type copolymer having a structure of polystyrene block-poly (styrene-butadiene) random block-polystyrene block with a bound styrene content of 62 mass%, where the hydrogenation rate was 98 %, Mn = 48000, Mw = 55000, and Mw/Mn = 1.146.

<Antioxidant (D)> (D-1) Phosphoric antioxidant (chemical name: 3,9- bis (2, 6-di-tert-butyl- 4-methylphenoxy)-2,4,8,10~ tetraoxa-3, 9-diphosphaspiro[5,5]undecane; product name: ADK STAB PEP-36® (ADK STAB PEP-36 is a registered trademark in Japan, other countries, or both); produced by ADEKA Corporation). <Other components> (Colorant) Carbon black with an average primary particle size of 16 nm.

(Polyolefin-based resin component) Ethylene-propylene copolymer (product name: TAFMER PO680J® (TAFMER P0680J is a registered trademark in Ja- pan, other countries, or both); produced by Mitsui Chemicals, Inc)

[0089] [Example 1] (A-1) 100 mass% was supplied from the most up- stream part (top feed) of a TEM58SS twin screw extruder (made by Toshiba Machine Co., Ltd., barrels: 13 (in- cluding the barrel below a first supply port hopper), screw diameter: 58 mm, L/D = 53; at a screw pattern that kneading discs L: 2, kneading discs R: 12 and kneading discs N: 4). When a length of all barrels (including the barrel below the first supply port hop- per) in the extruder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 38.5 %, and the bar- rel length of the remaining melting and kneading zone and melt transport zone was 61.5 % (where the barrel length of the melting and kneading zone was 38.5 %). The set temperature of all barrels Cl to C4 of the sol- id transport zone (excluding the barrel CO below the first supply port hopper for water cooling) was 180 °C, and the set temperature of all barrels C5 to C9 of the melting and kneading zone was 290 °C. For the barrels C10 to Cl2 in the melt transport zone, the set tempera- ture of C10 was 290 °C, the set temperature of Cll was 300 °C, and the set temperature of Cl2 was 320 °C. The die head was set at 320 °C. Nitrogen was blown to the die nozzle at a flow rate of 20 L/min. A vent port having a nitrogen injection line and a gas vent was provided at an opening above the barrel Cll, and nitro- gen was blown from the nitrogen injection line at a flow rate of 20 L/min during the extrusion. Further, the oxygen concentration inside the collecting hopper above the first supply port was 0.5 vol%. The melting and kneading were performed under the conditions of a screw rotation speed of 500 rpm and an extrusion rate of 400 kg/h to obtain a resin composition. The evalua- tion results of the obtained resin composition are listed in Table 1 below,

[0090] [Example 2] (A-1) 70 mass% and (B-1) 30 mass% were supplied from the most upstream part of the twin screw extruder described in Example 1 above and extruded using the ex- truder. The melting and kneading and extrusion were performed under the same conditions as in Example 1 to obtain a resin composition except the following condi- tions. When a length of all barrels (including the barrel below the first supply port hopper) in the ex- truder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 46.2 %, and the barrel length of the remaining melting and kneading zone and melt transport zone was 53.8 % (where the barrel length of the melting and kneading zone was 30.8 %). The set temperature of all barrels Cl to C5 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling) was 180 °C, and the set temperature of all barrels C6 to C2 of the melting and kneading zone was 290 °C. For the barrels Cl0 to Cl2 in the melt transport zone, the set tempera- ture of C10 was 290 °C, the set temperature of Cll was 300 °C, and the set temperature of C12 was 310 °C. The die head was set at 310 °C. No nitrogen was blown to the die nozzle. A vent port connected to a vent vacuum line was provided at an opening above the barrel C11, and the degree of vacuum of the vent was 7.998 kPa (60 Torr). The evaluation results of the obtained resin composition are listed in Table 1 below.

[0091] [Example 3] {(A-1) 50 mass%, (B-1) 30 mass% and (C-1) 20 mass% were supplied from the most upstream part of the twin screw extruder described in Example 1 above and extrud- ed using the extruder. The melting and kneading and extrusion were performed under the same conditions as in Example 1 to obtain a resin composition except the following conditions. When a length of all barrels (including the barrel below the first supply port hop- per) in the extruder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 53.8 %, and the bar- rel length of the remaining melting and kneading zone and melt transport zone was 46.2 % (where the barrel length of the melting and kneading zone was 30.8 %). For the barrels Cl to C6 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl was 50 °C, the set temperature of C2 to C4 was 100 °C, and the set temperature of C5 and C6 was 140 °C. The set temperature of all barrels C7 to Cl0 of the melting and kneading zone was 280 °C. The set temperature of barrels Cll and Cl2Z of the melt transport zone was 280 °C. The die head was set at 300 °C. No nitrogen was blown to the die nozzle. A vent port connected to a vent vacuum line was provided at an opening above the barrel C11, and the degree of vacuum of the vent was

7.998 kPa (60 Torr). Further, the oxygen concentration inside the collecting hopper above the first supply port was 1.0 vol%. The evaluation results of the ob- tained resin composition are listed in Table 1 below.

[0092] [Example 4] The melting and kneading and extrusion were per- formed under the same conditions as in Example 3 above to obtain a resin composition except that nitrogen was blown to the die nozzle at a flow rate of 20 L/min.

The evaluation results of the obtained resin composi- tion are listed in Table 1 below.

[0093] [Example 5] The melting and kneading and extrusion were per- formed under the same conditions as in Example 4 above to obtain a resin composition except that a vent port having a nitrogen injection line and a gas vent was provided at an opening above the barrel Cll, and nitro- gen was blown from the nitrogen injection line at a flow rate of 20 L/min during the extrusion. The evalu- ation results of the obtained resin composition are listed in Table 1 below.

[0094] [Example 6] The melting and kneading and extrusion were per- formed under the same conditions as in Example 3 to ob- tain a resin composition except that (A-1) was 30 mass%, (B-1) was 50 mass%, (C-1) was 20 mass%, and the oxygen concentration inside the collecting hopper above the first supply port was 1.5 vol%. The evaluation re- sults of the obtained resin composition are listed in Table 1 below.

[0095] [Example 7]

The melting and kneading and extrusion were per- formed under the same conditions as in Example 6 above to obtain a resin composition except the following con- ditions. (A-1) was 15 mass%, (B-1) was 65 mass%, and (C-1) was 20 mass%. When a length of all barrels (in- cluding the barrel below the first supply port hopper) in the extruder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 38.5 %, and the barrel length of the remaining melting and kneading zone and melt transport zone was 61.5 % (where the barrel length of the melting and kneading zone was 23.1 %). For the barrels Cl to C4 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl was 50 °C, the set temperature of C2 and C3 was 100 °C, and the set temperature of C4 was 130 °C. The set temperature of all barrels C5 to C7 of the melting and kneading zone was 270 °C. The set temperature of all barrels C8 to C12 of the melt transport zone was 270 °C. The die head was set at 280 °C. No nitrogen was blown to the die nozzle. A vent port connected to a vent vacuum line was provided at an opening above the barrel Cl1, and the degree of vacuum of the vent was 7.998 kPa (60 Torr). Further, the oxygen concentration inside the collecting hopper above the first supply port was 1.8 vol%. The evaluation results of the obtained resin composition are listed in Table 1 below.

[0096] [Example 8] The melting and kneading and extrusion were per- formed under the same conditions as in Example 3 above to obtain a resin composition except that {A-1) 50 mass%, (B-1) 29.5 mass%, (C-1) 20 mass% and (D-1) 0.5 mass% were supplied, the set temperature of all barrels Cl to C6 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling) was 150 °C, and the oxygen concentration inside the collecting hopper above the first supply port was

2.7 vol%. The evaluation results of the obtained resin composition are listed in Table 1 below.

[0097] [Example 9] (A-1) 65 mass%, (B-1) 20 mass%, (C-1) 14 mass%, (D-1) 0.5 mass% and carbon black 0.5 mass% of were supplied from the most upstream part of the twin screw extruder described in Example 1 above and extruded us- ing the extruder. The melting and kneading and extru- sion were performed under the same conditions as in Ex- ample 1 to obtain a resin composition except the fol- lowing conditions. When a length of all barrels (in- cluding the barrel below the first supply port hopper) in the extruder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 46.2 %, and the barrel length of the remaining melting and kneading zone and melt transport zone was 53.8 % (where the barrel length of the melting and kneading zone was 38.5 %). For the barrels Cl to C5 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl was 120 °C, the set temperature of C2 to C4 was 150 °C, and the set temperature of C5 was 180 °C. The set temperature of all barrels C6 to Cl0 of the melting and kneading zone was 280 °C. For the barrels Cll and Cl2 in the melt transport zone, the set temperature of Cll was 280 °C, and the set temperature of Cl2 was 300 °C. The die head was set at 310 °C. No nitrogen was blown to the die nozzle. A vent port connected to a vent vacuum line was provided at an opening above the barrel Cl1, and the degree of vacuum of the vent was 7.998 kPa (60 Torr). The oxygen concentration inside the collecting hopper above the first supply port was 2.0 vol%. The evaluation results of the obtained resin composition are listed in Table 1 below.

[0098] [Example 10]

The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except that 4 mass% of the (C- 1) 14 mass% was replaced with a polyolefin-based resin component TAFMER® P0680J. The evaluation results of the obtained resin composition are listed in Table 1 below.

[0099] [Example 11] The melting and kneading and extrusion were per- formed under the same conditions as in Example 3 to ob- tain a resin composition except that, for the barrels of the solid transport zone, the set temperature of C6 was 230 °C. The evaluation results of the obtained res- in composition are listed in Table 1 below.

[0100] [Example 12] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except that, for the barrels of the solid transport zone, the set temperature of C5 was 250 °C. The evaluation results of the obtained res- in composition are listed in Table 1 below.

[0101] [Comparative Example 1] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except the following condi- tions. When a length of all barrels (including the barrel below the first supply port hopper) in the ex- truder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 23.1 %, and the barrel length of the remaining melting and kneading zone and melt transport zone was 76.9 % (where the barrel length of the melting and kneading zone was 38.5 %). For the barrels Cl and C2 of the solid transport zone (exclud- ing the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl was 120 °C, and the set temperature of C2 was 180 °C. The set temperature of all barrels C3 to C7 of the melting and kneading zone was 280 °C. For the barrels C8 to Cl2 in the melt transport zone, the set temperature of C8 to Cll was 280 °C, and the set temperature of C12 was 300 °C. The evaluation results of the obtained resin compo- sition are listed in Table 1 below.

[0102] [Comparative Example 2] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except the following condi- tions. For the barrels Cl to C5 of the solid transport zone {excluding the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl was 230 °C, the set temperature of C2 to C4 was 250 °C, and the set temperature of C5 was 280 °C. The oxy- gen concentration inside the collecting hopper above the first supply port was 0.5 vol%. The evaluation re- sults of the obtained resin composition are listed in Table 1 below.

[0103] [Comparative Example 3] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except the following condi- tions. When a length of all barrels (including the barrel below the first supply port hopper) in the ex- truder was 100 %, the barrel length of the solid transport zone (including the barrel below the first supply port hopper) was 61.5 %, and the barrel length of the remaining melting and kneading zone and melt transport zone was 38.5 % (where the barrel length of the melting and kneading zone was 15.4 %). For the barrels Cl to C7 of the solid transport zone (excluding the barrel CO below the first supply port hopper for water cooling), the set temperature of Cl to C3 was 120 °C, the set temperature of C4 to C6 was 150 °C, and the set temperature of C7 was 180 °C. The set temperature of all barrels C8 and C9 of the melting and kneading zone was 280 °C. For the barrels Cl10 to Cl2 in the melt transport zone, the set temperature of C10 and Cll was 280 °C, and the set temperature of Cl2 was 300 °C. The oxygen concentration inside the collecting hopper above the first supply port was 0.5 vol%. The evaluation re- sults of the obtained resin composition are listed in Table 1 below.

[0104] [Comparative Example 4] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except that the oxygen concen- tration inside the collecting hopper above the first supply port was 4.5 vol®%. The evaluation results of the obtained resin composition are listed in Table 1 below.

[0105] [Comparative Example 5] The melting and kneading and extrusion were per- formed under the same conditions as in Comparative Ex- ample 2 to obtain a resin composition except that ni- trogen was blown to the die nozzle at a flow rate of 20 L/min, a vent port having a nitrogen injection line and a gas vent was provided at an opening above the barrel Cll, and nitrogen was blown from the nitrogen injection line at a flow rate of 20 L/min during the extrusion.

[0106] [Comparative Example 6] The melting and kneading and extrusion were per- formed under the same conditions as in Example 9 to ob- tain a resin composition except that, for the barrels of the solid transport zone, the set temperature of C4 and C5 was 250 °C. The evaluation results of the ob- tained resin composition are listed in Table 1 below.

[0107] Table 1 Example Example Example {| Example Example Example Example Example | Example Example Example | Example I 2 3 4 5 6 7 8 9 10 11 £2 Resi composition Others Length of the solid transport zone = Yo 38.5 2 53. 53. 53.8 53. 38.5 53. 46. 46.2 53. ‚2 Length of the melting and kneading zone or 33.5 10.8 308 308 30.8 20.8 231 308 38.5 38.5 308 385 1 0.) IV.

IRC SA DU DN 23. SA S23 ou DUE JO. when the length of all barrefs in the extruder is 100% i > ° > ° * Set temperature of barrels of the solid transport zone 180 50-140 50-140 50-140 50-140 50-130 120-180 120-180 50-230 120-250 Length of barrels having a set temperature of 50 °C to fo ; ) °C w e length of barrels of Method of M90 °Cowhenthelength of baels of % 100 100 100 100 100 100 toa 100 100 100 83 80 producing the solid transport zone (excluding the barre provided resin with the first supply post) is 100% Set temperature of barrels of the melt transport zone 290-320 290-310 280 280-300 280-300) 280-300 Production Toughness Ta Tr ey Te Te re ew ee Thermal Tensile strength retention after aging o < en © oe % 5 75 78 77 75 82 3 70 (140°C, 1000 B} ’ | |] ° | O1] 7 ’ ° —: Unmeasured

Table | {cont'd} Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example 1 2 3 4 5 6 Resi composition Others Length of the solid transport zone or 231 46.2 61.5 46.2 46.2 46.2 when the length of all barrels in the extruder is 100% “ or ne © ne ne ne Length of the melting and kneading zone a 385 385 15.4 385 385 385 when the. length of all barrels in the extroder is 100% “ or or or or or or Set temperature of barrels of the solid transport zone 120-180 120-180 120-180 Length of barrels having a set temperature of 50 °C to 190 °C wben the leogth of barrels of 5 - = % Method ot the solid transport Zone {excluding the barre] provided ” tae 0 tae tae 0 60 producing resin with the first supply port) is 100% composition Set temperature of barrels of the melt transport zone 280-300 280-300 280-300 280-300 280-300 280-300 ee Te ee Production EN em ability of collecting ted BH Toughness Thermal Tensile strength retention áfter aging i. s “> % 36 48 38 46 48 34 (140 °C.1000 b) > ° —: Ünmeasured

[0108] As indicated in Table 1, all the resin composi- tions of Examples 1 to 12 were produced with the produc- tion method described in the claims of the present disclo- sure. During the two hours of extrusion production, no gums were observed in the die nozzle, the stability of collecting strand was good, and no strand breakage was ob- served.

In Example 4, nitrogen gas was blown to the part of the die nozzle where the resin was discharged from a hole.

The tensile elongation and the tensile strength retention after aging tended to be excellent in Example 4 as com- pared with Example 3 in which no nitrogen was blown.

In Example 5, nitrogen gas was further blown into the vent port. The tensile elongation and the tensile strength retention after aging tended to be more excellent than those of Example 4.

In Example 8, an antioxidant component (CC) was added to the resin composition in addition to the production method of the present disclosure. In this way, the oxida- tion deterioration of resin during the extrusion was fur- ther suppressed, and the tensile elongation and the ten- sile strength retention after aging tended to be excel- lent.

In Example 9, although a colorant (carbon black) was added to the resin composition, the production stability and the resin performance according to the production method of the present disclosure were not affected, and a resin composition with good performance was obtained.

In Example 10, a polyolefin-based resin component was added. However, if the content was within 5 mass%, the production stability and the physical properties were not affected, and the tensile elongation and the tensile strength retention after aging tended to be excellent.

In both Examples 11 and 12, the barrel length and the set temperature of the solid transport zone were within the scope of the claims of the present disclosure, and the physical properties were good. However, for the length of barrels in the solid transport zone excluding the barrel provided with the first supply port, the length of barrels having a set temperature of 50 °C to 190 °C was in a range of 75 % to less than 100%, so that the toughness and the thermal stability of the molded product tended to slightly decrease as compared with the case where the length was 100 %.

On the other hand, in each of Comparative Examples 1 to 6, the resin composition was produced with a production method outside the scope of the claims of the present dis- closure, so that neither the production stability nor the physical properties were sufficient.

In Comparative Example 1, the length of the solid transport zone was short, and in Comparative Example 2, the setting temperature of the barrels the solid transport zone was high, both of which were outside the scope of the claims of the present disclosure. Therefore, generation and growth of gums were observed during the production. Neither the production stability nor the physical proper- ties were sufficient.

In Comparative Example 3, the length of the solid transport zone was too long and was outside the scope of the claims of the present disclosure. Unmolten materials were found in the resin composition, and the stability of collecting strand and the physical properties were insuf- ficient.

In Comparative Example 4, the oxygen concentration inside the collecting hopper was high, which was outside the scope of the claims of the present disclosure. Gener- ation and growth of gums were observed during the produc- tion. Neither the production stability nor the physical properties were sufficient.

Comparative Example 5 was similar to Comparative Ex- ample 2, where the set temperature of the barrels of the solid transport zone was high and outside the scope of the claims of the present disclosure, and nitrogen was blown to the die nozzle and to the vent port. Therefore, the growth of gums was suppressed, and the strand was stably collected to the end. However, gums were generated during the production, and the physical properties were insuffi- cient.

In Comparative Example 6, the set temperature of the solid transport zone was outside the scope of the claims of the present disclosure. As a result, although the strand was stably collected to the end, gums were generat- ed during the production. In addition, the physical prop- erties were insufficient.

INDUSTRIAL APPLICABILITY

[0109] According to the production method of the pre- sent disclosure, it is possible to significantly suppress the generation of degraded products of polyphenylene ether resin in a barrel of an extruder during extrusion and the generation of gums around a die nozzle to improve the ex- trusion production stability. In addition, since the con- tamination with foreign matters is reduced, it is possible to stably mass-produce a polyphenylene ether-based resin composition having good toughness. The obtained resin composition can be favorably used for household appliance and electronic office equipment members, electrical and electronic equipment, automotive applications, various in- dustrial products, and the like.

Claims

CONCLUSIONS

A method of producing a resin composition using an extruder, wherein the resin composition contains 10% by mass or more of polyphenylene ether (A), relative to a total amount of the resin composition which is 100% by mass , the extruder is a twin screw extruder having a solid material transport zone, a melting and kneading zone, and a molten material transport zone, the solid material transport zone having a barrel provided with a first supply port when a length of all barrels in the extruder is 100%, 30% to 60% from an upstream side of the extruder is the solids transport zone, and the remaining 40% to 70% is the melting and kneading zone and the transport zone For molten material, when a length of vessels forming the solid material transport zone, excluding the vessel provided with the first supply port, is 100%, 75% or more of the vessels are at a set temperature temperature in the range of 50 ° C to 190 ° C, vessels constituting the melting and kneading zone, and vessels constituting the molten material transport zone have a set temperature in a range of 250 ° C to 320 ° C, and a collection canister is provided above the first supply port which has an oxygen concentration of 3 vols or less.

A method for producing a resin composition according to claim 1, wherein when a length of vessels constituting the solid material transport zone, excluding the vessel provided with the first supply port, is 100%, 100% of the vessels has a set temperature in a range of 50 ° C to 190 ° C.

A method of producing a resin composition according to claim 1 or 2, wherein the molten material transport zone has an apertured vessel and a vent port with a nitrogen injection line and a gas valve is provided above. the opening .

A method for producing a resin composition according to any one of claims 1 to 3, wherein all raw materials for extrusion are supplied from the first feed port.

A method of producing a resin composition according to any one of claims 1 to 4, wherein the resin composition further contains 5% by mass to 80% by mass of a styrene-based resin (B), relative to the total amount of the resin composition which is 100 mass%.

A method for producing a resin composition according to any one of claims 1 to 5, wherein the resin composition further contains 0.1% to 25% by mass of a styrene-based thermoplastic elastomer (c}), relative to the weight of the resin composition. total amount of the resin composition which is 100 mass%.

A method of producing a resin composition according to any one of claims 1 to 6, wherein the resin composition further contains 0.001% to 3% by mass of an antioxidant (D), based on the total amount of the resin composition. which is 100 mass% $.

A method for producing a resin composition according to any one of claims 1 to 7, wherein in the resin composition a content of a polyolefin-based resin component is 5 mass or less, relative to the total amount of the resin composition comprising 100 masses. is. -0-0-0-