Abstract: A coil spring includes an elongated body (10) formed by a plurality of continuous coils (21, 31), and the body (10) includes an upper section (20) and a lower section (30), wherein pitches (22) and coil angles (23) of the coils (21) in the upper section (20) are consistent to form an upright profile (24) for the upper section (20), and wherein pitches (32) and coil angles (33) of two or more coils (31) at a free end of the lower section (30) is differed from the pitches (22) and the coil angles (23) of the coils (21) in the upper section (20) to form a gradually curved profile (34) for the lower section (30).

Abstract: A resin composition includes 100 parts by weight of a polybutadiene and 10 parts by weight to 40 parts by weight of a maleimide resin, wherein: the polybutadiene has a 1,2-vinyl content of greater than or equal to 85%; the polybutadiene has a lithium ion content of less than or equal to 100 ppm; and the resin composition is free from a polyphenylene ether resin. Moreover, an article may be made from the resin composition, including a prepreg, a resin film, a laminate or a printed circuit board.

Abstract: An epoxy resin oligomer is provided. The epoxy resin oligomer is obtained by the reaction of at least a first reactant and a second reactant, and the molecular weight of the epoxy resin oligomer is between 3000 and 9000, wherein the mole ratio of the first reactant and the second reactant is between 1:0.9 and 0.9:1, and each of the first reactant and the second reactant is a compound having two polymerizable groups.

Abstract: A resin composition and an article made from the resin composition are disclosed. The resin composition comprises: a first vinyl-containing polyphenylene oxide resin, a prepolymer thereof or both; and a second vinyl-containing polyphenylene oxide resin or a prepolymer thereof; wherein the first vinyl-containing polyphenylene oxide resin has a number average molecular weight of between 500 and 1500, and the second vinyl-containing polyphenylene oxide resin has a number average molecular weight of between 1600 and 3500.

Abstract: A resin composition and an article made from the resin composition are disclosed. The resin composition comprises: a first vinyl-containing polyphenylene oxide resin, a prepolymer thereof or both; and a second vinyl-containing polyphenylene oxide resin or a prepolymer thereof; wherein the first vinyl-containing polyphenylene oxide resin has a number average molecular weight of between 500 and 1500, and the second vinyl-containing polyphenylene oxide resin has a number average molecular weight of between 1600 and 3500.

Abstract: A thermoplastic epoxy matrix formulation, based on 100 parts by weight of the thermoplastic epoxy matrix formulation, includes 0.1 to 95 parts by weight of a difunctional epoxy resin and 0.1 to 80 parts by weight of a latent hardener, wherein the latent hardener is an amine compound containing two reactive hydrogens.

Abstract: A precursor blend for preparing a thermoplastic polymer for a fiber-reinforced composite material includes a major amount of a stoichiometric mixture of a diepoxide, and an amine compound selected from the group consisting of monofunctional primary amine and difunctional secondary amine, and a minor amount of a modifier selected from the group consisting of difunctional primary amine, trifunctional primary amine, triepoxide, tetraepoxide, and combinations thereof.

Abstract: An epoxy resin oligomer is provided. The epoxy resin oligomer is obtained by the reaction of at least a first reactant and a second reactant, and the molecular weight of the epoxy resin oligomer is between 3000 and 9000, wherein the mole ratio of the first reactant and the second reactant is between 1:0.9 and 0.9:1, and each of the first reactant and the second reactant is a compound having two polymerizable groups.

Abstract: A thermoplastic prepreg includes a latent resin and a fiber, wherein the latent resin at least includes a resin and a latent hardener or an initiator. The latent resin includes an in-situ polymerization formulation, and the latent resin has a viscosity of 500,000-70,000,000 cps at 25° C. The thermoplastic prepreg is suitable for various wet lay-up processes.

Abstract: A thermoplastic epoxy matrix formulation, based on 100 parts by weight of the thermoplastic epoxy matrix formulation, includes 0.1 to 95 parts by weight of a difunctional epoxy resin and 0.1 to 80 parts by weight of a latent hardener, wherein the latent hardener is an amine compound containing two reactive hydrogens.

Abstract: A precursor blend for preparing a thermoplastic polymer for a fiber-reinforced composite material includes a major amount of a stoichiometric mixture of a diepoxide, and an amine compound selected from the group consisting of monofunctional primary amine and difunctional secondary amine, and a minor amount of a modifier selected from the group consisting of difunctional primary amine, trifunctional primary amine, triepoxide, tetraepoxide, and combinations thereof.