An object of the present invention is to provide a fiber-reinforced thermoplastic resin sheet which can be manufactured into a molded body exhibiting excellent appearance quality as well as exhibits both high moldability and strength and a manufacturing method of such a fiber-reinforced thermoplastic resin sheet. The present invention relates to a fiber-reinforced thermoplastic resin sheet which is a random laminated body of a tape-shaped unidirectional prepreg and contains spread reinforcement fibers and a polymer (a) and in which the polymer (a) is a polymer of at least a bisphenol A type epoxy compound represented by Formula (1):

##STR00001##

[where n is an integer of 1 to 4] and a bisphenol compound selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol E, and bisphenol P, and M.sub.wa is 25,000 or more and a proportion (M.sub.wb/M.sub.wa) of M.sub.wb to M.sub.wa is 1.01 to 1.8, where M.sub.wa denotes a weight average molecular weight of the polymer (a) and M.sub.wb denotes a weight average molecular weight of a polymer (b) contained in a heat-treated fiber-reinforced thermoplastic resin sheet acquired by heating the fiber-reinforced thermoplastic resin sheet at 180° C. for 1 hour.

A magnetic powder is obtained by removing a dispersion medium from a magnetic fluid that includes magnetic particles, a dispersant and the dispersion medium. A magnetic powder composition includes the magnetic powder and a resin material, and a magnetic powder composition molded body is obtained therefrom. A method of producing a magnetic powder includes removing a dispersion medium from a magnetic fluid containing magnetic particles, a dispersant and the dispersion medium, and powdering a solid component obtained by removing the dispersion medium. A method of producing a magnetic powder composition and a method of producing a magnetic powder composition molded product are also provided.

Provided are an epoxy resin including: an epoxidized product of monoalkyl dihydroxybenzene; and a compound that is detected in the molecular weight range from a molecular weight at the peak top of the epoxidized product of the monoalkyl dihydroxybenzene to the molecular weight at the peak top+20 to 40 and has a peak area % of 0.1% to 0.8% in a GPC chart, and an epoxy resin including an epoxidized product of monoalkyl catechol in which the ratio of the total content of a cyclic compound having a cyclic structure that has two adjacent oxygen atoms derived from the monoalkyl catechol as constituent atoms and a monoglycidyletherified product of the monoalkyl catechol to the content of a diglycidyletherified product of the monoalkyl catechol is in the range of 0.10 to 0.40 as measured by high performance liquid chromatography.

Optical films comprising a polyester resin comprising a structural unit (A) of the following formula (1) wherein the content of the structural unit (A) based on the total structural units of the polyester resin is 76 mol % or greater: ##STR00001## wherein R.sub.1 is a hydrogen atom, CH.sub.3, or C.sub.2H.sub.5; R.sub.2 and R.sub.3 is each independently a hydrogen atom or CH.sub.3; and n is 1, for example, Decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6(7)-methanol. Retardation films and circularly or elliptically polarizing plates comprising the optical films are also provided.

A thermosetting composition including at least a thermosetting compound, the thermosetting composition satisfying relationships represented by formulas (i) and (ii) below:

0.80≤b/a≤0.98  (i), and

0.05≤c/a≤0.30  (ii), wherein a, b, and c represent storage moduli (unit: GPa) at 30° C., 100° C., and 260° C., respectively, of a cured product formed by curing a prepreg obtained by impregnating or coating a base material with the thermosetting composition.

The present invention provides a curable composition comprising a urethane-modified epoxy resin (A) as an essential component of a main material, and an acid anhydride (B) as an essential component of a curing agent, wherein the urethane-modified epoxy resin (A) is a reaction product of a polyisocyanate compound (a1), a polyester polyol (a2), and a hydroxyl group-containing epoxy resin (a3) as essential reaction raw materials. The curable composition of the invention is advantageous in that a cured product having excellent fracture toughness and excellent tensile strength can be formed from the composition.

Provided is a prepreg including the following constituents [A] to [C], the prepreg satisfying the following conditions [I] to [III]: [A]: a sizing agent-coated carbon fiber; [B]: an epoxy resin having a specific structure; and [C]: a hardener for [B], [I]: an epoxy resin composition including the constituents [B] and [C] has a nematic-isotropic phase transition temperature in a temperature range of 130° C. to 180° C.; [II] a prepreg after isothermal holding at 100° C. for 30 minutes does not have a high-order structure originated from a diffraction angle of 2θ=1.0° to 6.0° measured by wide angle X-ray diffraction at 100° C.; and [III]: a prepreg after isothermal holding at 180° C. for 2 hours has a high-order structure originated from the diffraction angle of 2θ=1.0° to 6.0° measured by wide angle X-ray diffraction at 180° C.

A prepreg is described having good handleability and a low resin flow, facilitating the work in the process of a molded body and improving the dimensional accuracy of the molded body, where the prepreg includes a fiber substrate; and a resin layer containing a thermosetting resin composition containing at least components [A] and [B] below, stacked on one surface of the fiber substrate, wherein the fiber substrate is impregnated with a part of the thermosetting resin composition of the resin layer, the thermosetting resin composition having a complex viscosity 3*24 at 24 C. of 20,000 to 100,000 Pa.Math.s and a complex viscosity 3*70 at 70 C. of 100 to 5,000 Pa.Math.s, and a volatile amount of the thermosetting resin composition is 1 mass % or less when a total mass of the prepreg is 100 mass %.

[A] Thermosetting resin

[B] Curing agent of [A]

A fiber reinforced plastic material is provided. The fiber reinforced plastic material includes a plurality of carbon fibers, and a vinyl ester resin or unsaturated polyester resin containing at least one low coefficient of linear thermal expansion (CLTE) filler.

A prepreg tape in which reinforcing fiber bundles are impregnated with a thermosetting resin composition, wherein the prepreg tape has a tack value measured at 23 C. at a plunger push pressure of 90 kPa of 5-40 kPa, a tack value measured at 45 C. and a plunger push pressure of 150 kPa of 35-100 kPa, and a drape value at 23 C. of 10-40, and includes unidirectional fibers arranged along the direction of length of the prepreg tape.