A three-dimensional printing kit can include a polymeric build material including from about 80 wt % to 100 wt % polymer particles having an average particle size from about 10 μm to about 150 μm and from about 0.01 wt % to about 2 wt % dihydrazide, and a fusing agent formulation including an aqueous liquid vehicle and a radiation absorber.

A method for producing a polyacetal resin composition which allows for suppression of formaldehyde generation from a molded article to an extremely low level, and stable suppression of mold deposits during molding. The polyacetal resin composition contains: 100 parts by mass of a polyacetal polymer (A); 0.01 to 0.50 parts by mass of an aliphatic carboxylic acid hydrazide (B); 0.001 to 0.50 parts by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups (C); and 0.001 to 0.30 parts by mass of an alkaline earth metal salt of aliphatic carboxylic acid (D), wherein the total amount of the components (B) and (C) with respect to 100 parts by mass of the polyacetal polymer (A) is 0.03 to 0.55 parts by mass, and the polyacetal polymer (A) is a polyacetal copolymer obtained by copolymerizing trioxane as a principal monomer (a) with a cyclic ether having at least one carbon-carbon bond as a comonomer (b) using a heteropolyacid represented by general formula (1) as a polymerization catalyst (c) to obtain a reaction product, and subsequently adding a carbonate of an alkali metal element or alkaline earth metal element (d) to the reaction product to deactivate the polymerization catalyst (c).

A method for producing a polyacetal resin composition which allows for suppression of formaldehyde generation from a molded article to an extremely low level, and stable suppression of mold deposits during molding. The polyacetal resin composition contains: 100 parts by mass of a polyacetal polymer (A); 0.01 to 0.50 parts by mass of an aliphatic carboxylic acid hydrazide (B); 0.001 to 0.50 parts by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups (C); and 0.001 to 0.30 parts by mass of an alkaline earth metal salt of aliphatic carboxylic acid (D), wherein the total amount of the components (B) and (C) with respect to 100 parts by mass of the polyacetal polymer (A) is 0.03 to 0.55 parts by mass, and the polyacetal polymer (A) is a polyacetal copolymer obtained by copolymerizing trioxane as a principal monomer (a) with a cyclic ether having at least one carbon-carbon bond as a comonomer (b) using a heteropolyacid represented by general formula (1) as a polymerization catalyst (c) to obtain a reaction product, and subsequently adding a carbonate of an alkali metal element or alkaline earth metal element (d) to the reaction product to deactivate the polymerization catalyst (c).

A method for producing a polyacetal resin composition which allows for suppression of formaldehyde generation from a molded article to an extremely low level, and stable suppression of mold deposits during molding. The polyacetal resin composition contains: 100 parts by mass of a polyacetal polymer (A); 0.01 to 0.50 parts by mass of an aliphatic carboxylic acid hydrazide (B); 0.001 to 0.50 parts by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups (C); and 0.001 to 0.30 parts by mass of an alkaline earth metal salt of aliphatic carboxylic acid (D), wherein the total amount of the components (B) and (C) with respect to 100 parts by mass of the polyacetal polymer (A) is 0.03 to 0.55 parts by mass, and the polyacetal polymer (A) is a polyacetal copolymer obtained by copolymerizing trioxane as a principal monomer (a) with a cyclic ether having at least one carbon-carbon bond as a comonomer (b) using a heteropolyacid represented by general formula (1) as a polymerization catalyst (c) to obtain a reaction product, and subsequently adding a carbonate of an alkali metal element or alkaline earth metal element (d) to the reaction product to deactivate the polymerization catalyst (c).

Disclosed is a method for producing a surface-treated carbon black, including a step (step (i)) of mixing a carbon-black-containing aqueous-slurry-solution in which a carbon black is dispersed in water with a dihydrazide compound, and subsequently removing the water. Disclosed is a method for producing a rubber wet masterbatch, including: a step (I) of mixing a carbon-black-containing aqueous-slurry-solution in which a carbon black is dispersed in water, a rubber latex solution, and a dihydrazide compound with each other to produce a carbon-black-containing aqueous-rubber-latex-solution; a step (II) of solidifying the resultant carbon-black-containing aqueous-rubber-latex-solution to produce a carbon-black-containing rubber solidified product; and a step (III) of dehydrating and drying the resultant carbon-black-containing rubber solidified product to produce the rubber wet masterbatch. These producing methods can give a vulcanized rubber low in exothermicity, and a rubber composition restrained from being lowered in scorch property (or having scorch resistance).

A rubber composition is prepared by mixing a specific hydrazide compound at a ratio of 0.5 to 3.0 parts by mass, zinc oxide at a ratio of 1 to 5 parts by mass, and carbon black having N.sub.2SA of 60 to 150 m.sup.2/g at a ratio of 30 to 60 parts by mass per 100 parts by mass of diene rubber containing 80 parts by mass or more of natural rubber. The rubber composition is prepared through (a) mixing the hydrazide compound and the carbon black to obtain a mixture, and (b) mixing the zinc oxide with the mixture obtained in step (a) to obtain a mixture. A maximum ultimate temperature during the mixture in step (a) is from 140 to 170° C. A storage modulus and elongation at break have a specific relationship.

A rubber composition is prepared by mixing a specific hydrazide compound at a ratio of 0.5 to 3.0 parts by mass, zinc oxide at a ratio of 1 to 5 parts by mass, and carbon black having N.sub.2SA of 60 to 150 m.sup.2/g at a ratio of 30 to 60 parts by mass per 100 parts by mass of diene rubber containing 80 parts by mass or more of natural rubber. The rubber composition is prepared through (a) mixing the hydrazide compound and the carbon black to obtain a mixture, and (b) mixing the zinc oxide with the mixture obtained in step (a) to obtain a mixture. A maximum ultimate temperature during the mixture in step (a) is from 140 to 170° C. A storage modulus and elongation at break have a specific relationship.

A rubber composition comprising at least one member selected from the group consisting of compounds represented by the following formulas (1) to (7) and 3-methyl-5-pyrazolone, and a rubber component:

##STR00001##

wherein the R group is a hydrazide group, an N′-alkylidene hydrazide group, an N-allyl carbamoyl group, a 3-carboxyl acryloyl group, a hydrazine carboxyamino group, a thiocarboxyl group, a thiol group, or a hydrogen atom; R.sup.4 is a sulfur atom or an oxygen atom; R.sup.5 is a thiol group or a hydroxy group; R.sup.6 is a C.sub.1-4 alkylene group; R.sup.7 is an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R.sup.8 is a hydrogen atom or an amino group; R.sup.9 is a heteroatom; and R.sup.10 is a heterocyclic group.

A rubber composition comprising at least one member selected from the group consisting of compounds represented by the following formulas (1) to (7) and 3-methyl-5-pyrazolone, and a rubber component:

##STR00001##

wherein the R group is a hydrazide group, an N′-alkylidene hydrazide group, an N-allyl carbamoyl group, a 3-carboxyl acryloyl group, a hydrazine carboxyamino group, a thiocarboxyl group, a thiol group, or a hydrogen atom; R.sup.4 is a sulfur atom or an oxygen atom; R.sup.5 is a thiol group or a hydroxy group; R.sup.6 is a C.sub.1-4 alkylene group; R.sup.7 is an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R.sup.8 is a hydrogen atom or an amino group; R.sup.9 is a heteroatom; and R.sup.10 is a heterocyclic group.

A rubber composition comprising at least one member selected from the group consisting of compounds represented by the following formulas (1) to (7) and 3-methyl-5-pyrazolone, and a rubber component:

##STR00001##

wherein the R group is a hydrazide group, an N′-alkylidene hydrazide group, an N-allyl carbamoyl group, a 3-carboxyl acryloyl group, a hydrazine carboxyamino group, a thiocarboxyl group, a thiol group, or a hydrogen atom; R.sup.4 is a sulfur atom or an oxygen atom; R.sup.5 is a thiol group or a hydroxy group; R.sup.6 is a C.sub.1-4 alkylene group; R.sup.7 is an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group; R.sup.8 is a hydrogen atom or an amino group; R.sup.9 is a heteroatom; and R.sup.10 is a heterocyclic group.