A gear is provided that has excellent continuous moldability for practical use, and both high slidability and high durability. The provided gear is a molded resin constructed of a resin composition comprising a thermoplastic resin (A) and cellulose nanofibers (B) with an average fiber diameter of 1000 nm or smaller, and having a number average molecular weight of the thermoplastic resin (A) in the range of 10,000 to 150,000, wherein a sliding surface of the gear with another gear teeth has an arithmetic mean surface roughness Sa of 3.0 μm or lower.

A gear is provided that has excellent continuous moldability for practical use, and both high slidability and high durability. The provided gear is a molded resin constructed of a resin composition comprising a thermoplastic resin (A) and cellulose nanofibers (B) with an average fiber diameter of 1000 nm or smaller, and having a number average molecular weight of the thermoplastic resin (A) in the range of 10,000 to 150,000, wherein a sliding surface of the gear with another gear teeth has an arithmetic mean surface roughness Sa of 3.0 μm or lower.

A resin composition having favorable heat stability while capable of primary curing at 140° C or lower, and having excellent heat resistance after curing, and a pre-preg having excellent heat resistance while a molded product after molding maintains mechanical characteristics are provided. The resin composition of the present invention comprises a constituent element (A): a cyanate ester resin, a constituent element (B): an imidazole compound, and a constituent element (C): silica, in which an average particle size of the silica is 0.4 μm or less. The pre-preg of the present invention comprises carbon fibers, and the resin composition of the present invention.

A resin composition having favorable heat stability while capable of primary curing at 140° C or lower, and having excellent heat resistance after curing, and a pre-preg having excellent heat resistance while a molded product after molding maintains mechanical characteristics are provided. The resin composition of the present invention comprises a constituent element (A): a cyanate ester resin, a constituent element (B): an imidazole compound, and a constituent element (C): silica, in which an average particle size of the silica is 0.4 μm or less. The pre-preg of the present invention comprises carbon fibers, and the resin composition of the present invention.

A polyacetal resin composition capable of keeping the generation of formaldehyde from a molded article at a very low level and stably keeping mold deposits at a minimum during molding. The polyacetal resin composition includes at least (A) 100 parts by mass of a polyacetal polymer, (B) 0.01-0.50 parts by mass of an aliphatic carboxylic hydrazide, (C) 0.001-0.50 part by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups, and (D) 0.001-0.30 part by mass of an alkaline earth metal salt of an aliphatic carboxylic acid. The total amount of (B) and (C) is 0.03-0.55 part by mass per 100 parts by mass of the (A) polyacetal polymer.

A polyacetal resin composition capable of keeping the generation of formaldehyde from a molded article at a very low level and stably keeping mold deposits at a minimum during molding. The polyacetal resin composition includes at least (A) 100 parts by mass of a polyacetal polymer, (B) 0.01-0.50 parts by mass of an aliphatic carboxylic hydrazide, (C) 0.001-0.50 part by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups, and (D) 0.001-0.30 part by mass of an alkaline earth metal salt of an aliphatic carboxylic acid. The total amount of (B) and (C) is 0.03-0.55 part by mass per 100 parts by mass of the (A) polyacetal polymer.

A polyacetal resin composition capable of keeping the generation of formaldehyde from a molded article at a very low level and stably keeping mold deposits at a minimum during molding. The polyacetal resin composition includes at least (A) 100 parts by mass of a polyacetal polymer, (B) 0.01-0.50 parts by mass of an aliphatic carboxylic hydrazide, (C) 0.001-0.50 part by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups, and (D) 0.001-0.30 part by mass of an alkaline earth metal salt of an aliphatic carboxylic acid. The total amount of (B) and (C) is 0.03-0.55 part by mass per 100 parts by mass of the (A) polyacetal polymer.

The present invention relates to a binder composition for metal powder injection molding, and more specifically, to a binder composition for metal powder injection molding, which can be promptly debound, facilitates the setting of flow conditions in an injection process, and enables the minimization of poor debinding such as swelling, carbonization of low-molecular-weight binders, and other internal defects, during a debinding process.

The binder composition for metal powder injection molding of the present invention contains 10 to 50 wt % of a high-viscosity polyoxymethylene polymer and 50 to 90 wt % of a low-viscosity polyoxymethylene polymer.

By containing polyoxymethylenes alone, which has been produced with different viscosities, without feeding of other monomers in the polymerization process of polyoxymethylene, the binder composition for metal powder injection molding according to the present invention is more economical through low manufacturing costs compared with a conventional technique in which the rate of decomposition by a gas-phase acid is controlled by viscosity adjustment in a polymerization process, and has excellent injection characteristics and debinding/sintering characteristics compared with a technique in which polyoxymethylene and other polymer resins, such as polyolefins and polyamides, are used together.

The present invention relates to a binder composition for metal powder injection molding, and more specifically, to a binder composition for metal powder injection molding, which can be promptly debound, facilitates the setting of flow conditions in an injection process, and enables the minimization of poor debinding such as swelling, carbonization of low-molecular-weight binders, and other internal defects, during a debinding process.

The binder composition for metal powder injection molding of the present invention contains 10 to 50 wt % of a high-viscosity polyoxymethylene polymer and 50 to 90 wt % of a low-viscosity polyoxymethylene polymer.

By containing polyoxymethylenes alone, which has been produced with different viscosities, without feeding of other monomers in the polymerization process of polyoxymethylene, the binder composition for metal powder injection molding according to the present invention is more economical through low manufacturing costs compared with a conventional technique in which the rate of decomposition by a gas-phase acid is controlled by viscosity adjustment in a polymerization process, and has excellent injection characteristics and debinding/sintering characteristics compared with a technique in which polyoxymethylene and other polymer resins, such as polyolefins and polyamides, are used together.

A polymer composition containing a polyoxymethylene polymer in the form of particles for rotational molding applications is disclosed. The polyoxymethylene polymer is selected to have physical characteristics and is combined with one or more impact modifiers in order to produce hollow vessels and other articles having improved physical properties, such as impact strength resistance.