JP2829434B2 - Pellet aggregate for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a pellet assembly for molding for mixing a base resin and various compounding agents by a master batch method.

(Prior Art) Generally, in the preparation of a conductive molding material or a colored molding material, mixing is performed by a master batch method as described below.

In other words, the masterbatch method is to prepare a masterbatch by adding a compounding agent such as a conductive filler or a coloring agent to be added in order to impart a desired property to a molding material in a predetermined ratio in the base resin in advance, In this method, the master batch pellets are mixed and diluted in a base resin pellet to obtain a molding material having desired characteristics.

(Problems to be Solved by the Invention) However, in such a conventional master batch method, particularly when preparing a conductive molding material, there is a large specific gravity difference between the base resin pellet and the master batch pellet. During the molding operation, in the hopper of the molding machine, a phenomenon occurs in which the master batch pellets of the conductive filler having a large specific gravity sink before the base resin pellets, and the mixing ratio of the two changes with time.

Therefore, it has been difficult to produce a molded article having a stable conductivity in which the conductive filler is uniformly dispersed in the base resin.

Further, depending on the degree of variation in the mixing ratio between the base resin pellets and the master batch pellets, there is a problem that a portion having no desired conductive performance is generated in the molded product.

Furthermore, in order to solve the above-mentioned inconveniences, a method of attaching a stirring device to a hopper of a molding machine, or using a quantitative mixer has been considered, but these methods can achieve a certain degree of solution. However, new equipment investment was required and the cost was increased, and partial uneven distribution and poor dispersion of the compounding agent in the molded product could not be completely eliminated.

The present invention has been made in order to solve these problems, and the ratio (ratio) of the compounding agent mixed and contained in the entire material is fixed at any part, and the molding material for obtaining a molded product having stable characteristics is obtained. It is intended to provide a pellet aggregate.

[Constitution of the Invention] (Means for Solving the Problems) The molding pellet aggregate of the present invention is a masterbatch pellet obtained by adding a desired compounding agent to a base resin.
It is characterized in that one or more pieces and one or more base resin pellets are joined and integrated.

In the present invention, the ratio of the number of the master batch pellets and the base resin pellets to be joined and integrated, the size of one pellet, and the arrangement of these pellets can be arbitrarily set. The compounding ratio of the compounding agent in the entire molding material can be freely changed.

However, if the size of one such pellet aggregate is too large, it may cause a compounding agent or poor dispersion in the molding process or cause clogging in a molding machine hopper.

That is, suitable sizes that can specifically perform good molding are 3 to 15 mm in length, 3 to 8 mm in width, and 10 mm or less in thickness, and the size of one molding material falls within such a range. It is desirable to stop.

(Function) In the pellet aggregate for molding of the present invention, the masterbatch pellets containing the compounding agent and the base resin pellets are assembled and joined together in an appropriate number, and the mixing ratio of the compounding agent is determined. Any part of the material can be constant and evenly distributed.

Therefore, it is possible to obtain a molded product in which the characteristics of each part are uniform and stable, and have no variation.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of a molding pellet aggregate of the present invention.

In the figure, reference numeral 1 denotes a cylindrical masterbatch pellet, which is the same or similar to a base resin described later on the outer periphery of a collection of fibrous conductive fillers 2 such as copper fiber and stainless steel fiber. Convergent layer 3 made of resin
Is covered.

Around the master batch pellet 1 having such a structure, two cylindrical pellets 4 made of a base resin such as a polypropylene resin, a polystyrene resin, a polyamide resin, and a polycarbonate resin are arranged so as to face each other. I have. The contact portions on the outer peripheral surfaces of these pellets are heated and fused together.

 Another embodiment of the present invention is shown in FIG.

In this embodiment, six base resin pellets 4 of substantially the same size are arranged without gaps around one master batch pellet 1 and are integrally joined by heat fusion.

In the molding pellet aggregate of the embodiment configured as described above, since the master batch pellets 1 and the base resin pellets 4 are assembled at an appropriate ratio and fused and integrated, during kneading molding, The master batch pellet 1 having a higher specific gravity does not sink first, and can be uniformly mixed and dispersed.

Also, by changing the number of base resin pellets 4 arranged and joined around the master batch pellets 1,
By changing the collection ratio of the conductive filler 2 per pellet aggregate, the mixing ratio of the conductive filler 2 as the whole molding material can be arbitrarily set.

In the above embodiments, the masterbatch pellets having a two-layer separation structure in which the conductive fillers 2 are assembled and the converging layer 3 is coated on the outer periphery are used, but the present invention is not limited to such a structure. . That is, when a powdery material such as a coloring agent or a metal powder is used as a compounding agent, such a powdery compounding agent is directly mixed into the base resin to form a master batch, and from here onward, Pellets composed of one layer can be manufactured.

Further, the individual shapes of the master batch pellet 1 and the base resin pellet may be spherical, cubic, or the like in addition to the columnar shape.

[Effects of the Invention] As described above, in the molding pellet aggregate of the present invention, since the compounding ratio of the compounding agent to the base resin is constant for each aggregate, the weight, conductivity, color, etc. The characteristics do not vary from product to product or from product to product.

Therefore, it is possible to mass-produce a molded product having uniform and stable characteristics in each part, and to improve the product yield.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the pellet assembly for molding of the present invention, and FIG. 2 is a perspective view showing another embodiment. 1 Master batch pellets 2 Conductive filler 3 Converging layer 4 Base resin pellets

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B29B 9/00-9/16

Claims (1)

(57) [Claims] The present invention is characterized in that one or more masterbatch pellets containing a desired compounding agent in a base resin and one or more base resin pellets are joined and integrated. Pellet assembly for molding.