The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals.

Disclosed are a gradient resin, a preparation method therefor and the use thereof. The gradient resin of the present application is formed by fusing different layers with color transition changes, wherein the color transition change between the two adjacent layers is in the range of 0.1% to 20%. The gradient resin is composed of, by mass percentage, 98%-99.99% of a resin powder and 0.01%-2% of a pigment.

A resin composition or the like may exhibit high vibration damping properties even at a relatively high temperature, have good moldability, and have excellent impact resistance. The resin composition contains a thermoplastic resin (A), a thermoplastic resin (B), and a polar resin (C), wherein the resin composition satisfies (1) to (3): (1) the thermoplastic resin (B) has at least one of a reactive functional group and a monomer unit containing a hetero atom; (2) the thermoplastic resin (A) and the thermoplastic resin (B) are different types of resins; (3) with respect to the total mass of the resin composition, the content of the thermoplastic resin (A) is 1 to 30% by mass, the content of the thermoplastic resin (B) is 1 to 30% by mass, and the content of the polar resin (C) is 40 to 98% by mass.

Provided is a method for producing a resin composition from which can be formed a molded body having excellent tensile elongation and/or rigidity, and more preferably a molded body which stably achieves both high tensile elongation and high rigidity. An aspect of the present invention provides a method for producing a resin composition which contains a first component and a second component, said method comprising a kneading step for kneading the first component and the second component via an extruder provided with a kneading zone that includes a plurality of narrow gap zones in which the gap between a cylinder inner wall and a screw is not more than 2 mm. An aspect of the present invention provides a method for producing a resin composition which contains a first component and a second component, said method comprising a kneading step for kneading the first component and the second component via an extruder provided with a kneading zone that includes a plurality of high-pressure zones in which the pressure is not less than 0.1 MPa, wherein out of the plurality of high-pressure zones, a maximum pressure zone in which the pressure is the highest has a pressure [P1] of not less than 0.5 MPa, and the ratio [P1/P2] of the pressure [P1] to the average value [P2] of pressures in high-pressure zones other than the maximum pressure zone is greater than 1 but not greater than 100.