Provided is a method of preparing a superabsorbent polymer. More particularly, provided is a method of preparing a superabsorbent polymer, the method capable of preparing the superabsorbent polymer maintaining excellent basic absorption performances such as centrifugal retention capacity, absorbency under load, etc. while also exhibiting an improved absorption rate.

The resin composition according to one aspect is a resin composition containing a polyamic acid and a solvent, wherein the polyamic acid has a repeating unit represented by the following general formula (1) in a molecular chain, and the molecular chain has a structure represented by the following general formula (2) at one end or both ends. The proportion of the structure represented by the following general formula (2) relative to 1 mol of the repeating unit represented by the following general formula (1) is 0.001 mol or more and 0.1 mol or less. In the following general formulas, R.sup.1 is a tetravalent organic group; R.sup.2 is a divalent organic group; and R.sup.3 is an organic group having 15 or less carbon atoms.

##STR00001##

The resin composition according to one aspect is a resin composition containing a polyamic acid and a solvent, wherein the polyamic acid has a repeating unit represented by the following general formula (1) in a molecular chain, and the molecular chain has a structure represented by the following general formula (2) at one end or both ends. The proportion of the structure represented by the following general formula (2) relative to 1 mol of the repeating unit represented by the following general formula (1) is 0.001 mol or more and 0.1 mol or less. In the following general formulas, R.sup.1 is a tetravalent organic group; R.sup.2 is a divalent organic group; and R.sup.3 is an organic group having 15 or less carbon atoms.

##STR00001##

An example method of forming a biodegradable component includes extruding a mixture of biodegradable material and water through a die. The method further includes dividing the extruded mixture to form a plurality of biodegradable pellets. The method further includes forming the plurality of biodegradable pellets into a component. The water acts as a binding agent to bind the plurality of biodegradable pellets to one another.

In the composition according to the embodiment, the content of an unreacted diisocyanate monomer in a urethane-based prepolymer may be controlled to control the physical properties thereof such as gelation time. Thus, since the micropore characteristics, polishing rate, and pad cut rate of a polishing pad obtained by curing the composition according to the embodiment may be controlled, it is possible to efficiently manufacture high-quality semiconductor devices using the polishing pad.

Coating compositions comprising a polymer binder and a sphere selected from porous metal oxide spheres formed from metal oxide particles and having, e.g., an average porosity of from 0.10 to 0.90; polymer spheres formed from a multimodal distribution of polymer particles; or mixtures thereof, are described herein. The sphere enhances the reflective characteristics of the coating compositions with respect to electromagnetic radiation. In particular, the coating compositions when dried, can exhibit UV reflectance, visible light reflectance, IR reflectance, or a combination thereof.

Coating compositions comprising a polymer binder and a sphere selected from porous metal oxide spheres formed from metal oxide particles and having, e.g., an average porosity of from 0.10 to 0.90; polymer spheres formed from a multimodal distribution of polymer particles; or mixtures thereof, are described herein. The sphere enhances the reflective characteristics of the coating compositions with respect to electromagnetic radiation. In particular, the coating compositions when dried, can exhibit UV reflectance, visible light reflectance, IR reflectance, or a combination thereof.

An expandable structural adhesive film for bonding metal parts. The adhesive film comprises at least one first epoxy compound; at least one epoxy curing agent; at least one blowing agent; at least one film-forming agent; and at least one impact modifier. The structural adhesive film exhibits an elongation at break of at least 300% according to tensile test DIN EN ISO 527 and a free expansion rate according to EN 2667-3 of at least 45%.

Provided is a flame retardant and heat insulating sheet having high flame retardancy and a high heat insulating property. Also provided is a flame retardant heat insulator including such flame retardant and heat insulating sheet. A flame retardant and heat insulating sheet according to one embodiment includes: a flame retardant and heat insulating layer formed from a resin composition (A); and a heat insulating layer, wherein the resin composition (A) contains: a binder resin; a low-melting point inorganic substance; a high-melting point inorganic substance; and voids. A flame retardant and heat insulating sheet according to one embodiment includes: a flame retardant and heat insulating layer formed from a resin composition (B); and a heat insulating layer, wherein the resin composition (B) contains: a binder resin that produces a high-melting point inorganic substance when heated; a low-melting point inorganic substance; and voids and/or a void-forming agent.

The rubber-plastic composite foamed material of the present invention is made by mixing and foaming a plurality of components including 100 parts by weight of rubber, 5-70 parts by weight of hollow glass microspheres, 2-25 parts by weight of carbon black, 10-40 parts by weight of softening oil, 10-30 parts by weight of sulfur ointment, 0.5-5 parts by weight of antioxidant, 0.5-10 parts by weight of crosslinking agent and 2-12 parts by weight of foaming agent. By including hollow glass microspheres into the composition, the rubber-plastic composite foamed material of the present invention exhibits better compression resistance and heat retention.