Granulated colorant and related art

Abstract

A granulated colorant as a granulation product of a powdery nigrosine dye, that has a bulk density of 0.4 to 0.7 g / ml and a hardness of 1 to 20 N. A high-concentration master batch obtained by blending a granulated colorant and a thermoplastic resin, which comprises 25 to 100 parts by weight of a nigrosine dye in the granulated colorant per 100 parts by weight of the thermoplastic resin. A colored composition comprising a granulated colorant or high-concentration master batch and a thermoplastic resin or thermoplastic elastomer.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a nigrosine granulated colorant that is used to impart a color to thermoplastic resin and for other purposes and has good handlability and good dispersibility in resin, a method of producing the same, a high-concentration master batch using the granulated colorant, a method of producing the same, and a colored composition using the granulated colorant or high-concentration master batch.[0003]2. Description of the Prior Art[0004]Because thermoplastic resins have excellent mechanical and chemical properties, they are widely used in plastic molding products in the field of components for automobiles, electric / electronic products and the like, and the demands are increasing in the field of engineering plastics. Additionally, thermoplastic resins are fitted to a broad range of industrial applications by formulating fibrous reinforcing material in thermoplastic resins to improve the heat resis...

AI Technical Summary

Benefits of technology

[0012]The aforementioned hardness (hardness determined using a KIYA type hardness meter) is preferably 2 to 15 N, more preferably 3 to 12 N. By rendering the granulated colorant to have such a hardness, both good handlability during transportation and the like and good dispersibility of nigrosine dye in resin can be achieved at the same time.

[0029]Because the colored composition of the present invention has low anisotropy and is excellent in heat resistance, sliding quality and dimensional accuracy, is excellent in mechanical properties, particularly in impact strength, and confers excellent surface appearance to molded products, it is useful as an engineering plastic in, for example, electric / electronic components such as connectors, sockets, relay case switches, variable condenser cases, optical pickups, plugs, printed substrates, tuners, speakers, microphones, headphones, FDD chassis, motor brush holders, parabola antennas, computer-related components, VTR components, television components, irons, hair dryers, electric rice cooker components, microwave oven components, acoustic components, audio / laser discs, compact discs, lighting components, refrigerator components, air conditioner components, and word processor components; office machine components such as typewriter parts; telephone-related components, facsimile-related components, copying machine-related components, washing devices, motor components, lighters, machine-related components; optical equipment / precision equipment-related components such as microscopes, binoculars, cameras, and watches and clocks; automobile / vehicle-related components such as alternator connectors, IC regulators, various valves such as exhaust gas valves, various fuel supply / exhaust / air intake system pipes, air intake nozzles, intake manifolds, fuel pumps, engine coolant joints, carburetor main bodies, carburetor spencers, air flowmeters, starter switches, transmission wire harnesses, window washer nozzles, air conditioner panel switch substrates, fuse connectors, horn terminals, electric appliances insulation panels, and igniter cases; and various other applications.

Problems solved by technology

Generally, in coloring a fiber-reinforced thermoplastic resin, a problem arises that the colorant (particularly black pigment) is difficult to sufficiently uniformly disperse in the resin even with a long time of kneading, because a fibrous reinforcing material is present in the resin.

In particular, the spoilage of the gloss, appearance and the like of the colored molded product by the fibrous reinforcing material floating on the surface of the molded product during molding has been problematic.

Additionally, because nigrosine dyes are powders having small values of bulk density and average particle diameter, nigrosine dye dusting can occur during dye charge, blending with the resin, and the like, posing the problem with work environment deterioration, so that special measures have been required to prevent the dusting.

In this manufacturing process, however, drawbacks, including phenomena such as bridging in the hopper and unsmooth feed of raw materials (resin, nigrosine dye, etc.) into the screw during extrusion kneading due to fluidity differences between nigrosine dye and resin, and a lack of fluidity due to dye wetting and adhesion as a result of dye exposure to the gas from the resin, additives and the like in the extrusion process, have been likely.

As such, nigrosine dyes are extremely poorly handlable; it has been difficult to fill a nigrosine dye in a master batch at high concentrations.

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