Provide is a polymer having a narrow molecular weight distribution by living radical polymerization.

A polymer manufacturing method comprising a step of performing living radical polymerization using 0.005 to 0.5 parts by mass of an oxygen radical scavenger per 100 parts by mass of a radical polymerizable monomer.

A method of preparing an acrylonitrile-based copolymer for a carbon fiber. The method includes: preparing a reaction solution including a (meth)acrylonitrile-based monomer and a first reaction solvent; adding a first portion of a radical polymerization initiator to the reaction solution to initiate polymerization; and adding a second portion of the radical polymerization initiator to the reaction solution when a polymerization conversion ratio is between 70 to 80%.

The present invention includes a first raw material feeding unit, a second raw material feeding unit, a reactor unit, and a controller configured to control the amount of a first raw material being fed from the first raw material feeding unit to the reactor unit, the amount of a second raw material being fed from the second raw material feeding unit to the reactor unit, the temperature of the first raw material being fed from the first raw material feeding unit to the reactor unit, and the temperature of the second raw material being fed from the second raw material feeding unit to the reactor unit. The first raw material is raw material monomer solution containing a raw material monomer. The second raw material is polymerization initiator solution containing a polymerization initiator. A reaction product is polymer compound resulting from a living anionic polymerization reaction of the raw material monomer.

An aspect of the present invention relates to a resin composition containing an acrylic resin and a curing agent, in which the acrylic resin contains a polymerization unit (A) of a (meth)acrylate having an epoxy group, a polymerization unit (B) of a (meth)acrylate having a cyano group, and a polymerization unit (C) of a (meth)acrylate having an isobornyl group, a weight average molecular weight of the acrylic resin is 50,000 or more and 3,000,000 or less, and a storage modulus of a cured product of the resin composition at 200 C. is 0.1 MPa or more and 3.5 MPa or less.

An aspect of the present invention relates to a resin composition containing an acrylic resin and a curing agent, in which the acrylic resin contains a polymerization unit (A) of a (meth)acrylate having an epoxy group, a polymerization unit (B) of a (meth)acrylate having a cyano group, and a polymerization unit (C) of a (meth)acrylate having an isobornyl group, a weight average molecular weight of the acrylic resin is 50,000 or more and 3,000,000 or less, and a storage modulus of a cured product of the resin composition at 200 C. is 0.1 MPa or more and 3.5 MPa or less.

The present invention provides a polymer-based piezoelectric composite material from which a piezoelectric film capable of outputting a higher sound pressure is obtained in a case of using a piezoelectric speaker, a piezoelectric film formed of the polymer-based piezoelectric composite material, and a piezoelectric speaker and a flexible display which are formed of the piezoelectric film. The polymer-based piezoelectric composite material of the present invention is a polymer-based piezoelectric composite material including a polymer matrix which contains a polymer containing a group represented by Formula (1), and piezoelectric particles.
*-L.sup.1-CR.sup.1R.sup.2CNFormula (1) In Formula (1), L.sup.1 represents a divalent linking group excluding a divalent aliphatic hydrocarbon group. R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

The present invention provides a polymer-based piezoelectric composite material from which a piezoelectric film capable of outputting a higher sound pressure is obtained in a case of using a piezoelectric speaker, a piezoelectric film formed of the polymer-based piezoelectric composite material, and a piezoelectric speaker and a flexible display which are formed of the piezoelectric film. The polymer-based piezoelectric composite material of the present invention is a polymer-based piezoelectric composite material including a polymer matrix which contains a polymer containing a group represented by Formula (1), and piezoelectric particles.
*-L.sup.1-CR.sup.1R.sup.2CNFormula (1) In Formula (1), L.sup.1 represents a divalent linking group excluding a divalent aliphatic hydrocarbon group. R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group, or an aryl group.