The present invention provides a method for producing an oxymethylene copolymer resin composition, comprising: adding to an oxymethylene copolymer (A), an Mn micromole of an amine-substituted triazine compound (B) per gram of the oxymethylene copolymer (A), an Mc micromole of a choline hydroxide (C) per gram of the oxymethylene copolymer (A), and 0.05 to 1.1 parts by weight of an antioxidant (D) with respect to 100 parts by weight of the oxymethylene copolymer (A), and melt kneading a mixture of the oxymethylene copolymer (A), amine-substituted triazine compound (B), the choline hydroxide (C), and the antioxidant (D), wherein Mn (μmol/g-POM) and Mc (μmol/g-POM) satisfy: 6.5<(Mn+Mc×8)<25, 0.5<Mn<7.0, and 0.0<Mc.

A block copolymer including a polymer block (A) containing more than 70 mol % of a unit derived from an aromatic vinyl compound, and a polymer block (B) containing 30 mol % or more of a unit derived from a conjugated diene compound is provided. The block copolymer satisfies the conditions: (1): a content of the polymer block (A) in the block copolymer is 1 to 70% by mass; (2): a maximum width of a series of temperature regions where tan δ measured in accordance with JIS K7244-10 (2005), under conditions including a strain amount of 0.1%, a frequency of 1 a measurement temperature of −70 to 100° C., and a temperature rise rate of 3° C./min, is 1.0 or more is less than 16° C.; (3): a temperature at a peak position of tan δ in the condition (2) is 0° C. to +50° C.; and (4): a mobility parameter M indicating a mobility of the polymer block (B) is 0.01 to 0.25 sec.

A block copolymer including a polymer block (A) containing more than 70 mol % of a unit derived from an aromatic vinyl compound, and a polymer block (B) containing 30 mol % or more of a unit derived from a conjugated diene compound is provided. The block copolymer satisfies the conditions: (1): a content of the polymer block (A) in the block copolymer is 1 to 70% by mass; (2): a maximum width of a series of temperature regions where tan δ measured in accordance with JIS K7244-10 (2005), under conditions including a strain amount of 0.1%, a frequency of 1 a measurement temperature of −70 to 100° C., and a temperature rise rate of 3° C./min, is 1.0 or more is less than 16° C.; (3): a temperature at a peak position of tan δ in the condition (2) is 0° C. to +50° C.; and (4): a mobility parameter M indicating a mobility of the polymer block (B) is 0.01 to 0.25 sec.

A polyacetal resin composition capable of minimizing degradation when a molded body thereof comes into contact with an acidic cleaner. The polyacetal resin composition contains with respect to (A) 100 parts by mass of a polyacetal copolymer in which the amount of a hemiformal end group is 0.8 mmol/kg or less, (B) more than 1.0 parts by mass and at most 5.0 parts by mass of a hindered phenol-based antioxidant, and (C) more than 4.0 parts by mass and at most 30 parts by mass of magnesium oxide.

A polyacetal resin composition capable of minimizing degradation when a molded body thereof comes into contact with an acidic cleaner. The polyacetal resin composition contains with respect to (A) 100 parts by mass of a polyacetal copolymer in which the amount of a hemiformal end group is 0.8 mmol/kg or less, (B) more than 1.0 parts by mass and at most 5.0 parts by mass of a hindered phenol-based antioxidant, and (C) more than 4.0 parts by mass and at most 30 parts by mass of magnesium oxide.

To provide a resin composition, a pellet, a composite molded article, a method for manufacturing a composite molded article and a tank, all capable of enabling tight joining and integration of the polyacetal resin molded article and the polyethylene resin molded article, and of suppressing formaldehyde emission and occurrence of mold deposit. The resin composition contains a resin ingredient and melamine, the resin ingredient containing a polyacetal resin and a maleic anhydride-modified polyethylene resin, the polyacetal resin and the maleic anhydride-modified polyethylene resin following a mass proportion of (20 to 49):(80 to 51), and molar concentration of the maleic anhydride group capable of reacting with amino group of melamine contained in the resin composition being 5 to 25 μmol/g.

To provide a resin composition, a pellet, a composite molded article, a method for manufacturing a composite molded article and a tank, all capable of enabling tight joining and integration of the polyacetal resin molded article and the polyethylene resin molded article, and of suppressing formaldehyde emission and occurrence of mold deposit. The resin composition contains a resin ingredient and melamine, the resin ingredient containing a polyacetal resin and a maleic anhydride-modified polyethylene resin, the polyacetal resin and the maleic anhydride-modified polyethylene resin following a mass proportion of (20 to 49):(80 to 51), and molar concentration of the maleic anhydride group capable of reacting with amino group of melamine contained in the resin composition being 5 to 25 μmol/g.

Disclosed herein are a novel polyacetal resin composition and a vehicle fuel pump module made of the same with excellent acid resistance.

Disclosed herein are a novel polyacetal resin composition and a vehicle fuel pump module made of the same with excellent acid resistance.

An oxymethylene copolymer resin composition, which includes (i) an oxymethylene copolymer, (ii) a derivative of an aryl boron fluoride compound, and (iii) a layered double hydroxide; and a method for producing the same.