JP2817128B2 - Polyethylene resin coloring composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyethylene resin colored composition for giving a pearl-like appearance to a polyethylene resin molded product such as a resin bottle.

[0002]

2. Description of the Related Art Conventionally, resin bottles such as detergents and cosmetic containers are colored by rutile-type titanium oxide, iron oxide,
Inorganic pigments such as ultramarine blue or organic pigments such as azo-based or phthalocyanine-based are added to the raw material resin. In recent years, in order to give the resin bottle a pearly feeling from the viewpoint of the design of these resin bottles, mica is used. (Mica) pearl pigments have come to be used. As a method of molding a resin bottle,
Conventionally, an extruder-type blow molding machine has been used to heat, melt and knead a resin and a colorant, extrude a parison (pipe-shaped extrudate) through a die, sandwich the parison with a mold, and blow air. A method of forming a bottle has been adopted. At this time, when the parison is extruded, in the coloring with a conventional type of inorganic pigment or organic pigment,
Since the parison having a smooth surface (skin) is extruded, the molded resin bottle also has an excellent appearance with commercial value.

[0003]

[Problems to be solved by the invention]
In order to further enhance the design, a mica pearl pigment is used as a coloring agent to mold a resin bottle in the same manner as before, and the parison extruded from the die of the blow molding machine is kneaded due to the structure of the die. A thin streak is formed in the vertical direction of the resin bottle at the part where the material and the kneaded material wrap around and join in the die (weld part) (weld line), and only the mica pearl pigment partially aggregates around this weld part However, there is a problem that a poor appearance is caused. This is because the mica pearl pigment is scaly particles, so these particles are joined and stacked in the weld part,
On the other hand, the part other than the weld part is a phenomenon in which particles are mixed in a direction perpendicular to the weld part, and furthermore, this weld part is emphasized due to the light interference effect of the mica pearl pigment, forming a vertical streak shape This causes poor appearance of the molded product.

[0004] The above-mentioned poor appearance may be caused by mixing a diluting resin with a diluting resin by using a coloring agent such as a coloring master batch even if a color compound such as a coloring masterbatch is used in advance before a blow molding machine is put in. In any of the coloring and molding methods in which the mica pearl pigment is used, it is generated as long as a mica pearl pigment is used. As a method for solving such a problem, a method of changing the structure of the die of the blow molding machine or a method of changing a position of a weld portion of the die can be considered.
Machine improvement, die improvement, etc. are too economically problematic. In addition, since no hindrance is observed when molding resin bottles of products that do not use mica pearl pigments,
Improving the molding machine is not always the preferred method. Therefore, an object of the present invention is to solve the above-mentioned problem of poor appearance that occurs when a mica pearl pigment is used, and to provide a good pearl appearance even when a normal blow molding machine is used as it is. It is to provide a polyethylene resin coloring composition which can be obtained.

[0005]

The above object is achieved by the present invention described below. That is, the present invention provides a polyethylene resin of 0 to 99.2 parts by weight, a mica pearl pigment of 0.3 to 5 parts.
A polyethylene resin colored composition comprising 0 parts by weight and 0.5 to 99.7 parts by weight of an acid-modified polyethylene.

[0006]

By adding an appropriate amount of an acid-modified polyethylene to a composition comprising a specific ratio of a polyethylene resin and a mica pearl pigment, a resin bottle having a smooth surface and an excellent design without weld lines can be obtained. A polyethylene resin coloring composition is provided.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention is described in more detail with reference to preferred embodiments. The polyethylene resin used in the present invention has a density (g / cc) of 0.94 to 0.9.
6. MFR (g / 10 min) is about 0.1 to 10; such a polyethylene resin can be easily obtained from the market and used.

The mica pearl pigment used in the present invention is a fine mica having a laminated structure, or a pearl pigment obtained by treating mica with titanium oxide to further develop a pearly feeling. The average particle size is about 5 to 200 μm, and such mica pearl pigment can be easily obtained from the market and used in the present invention. Naturally, these mica pearl pigments may have been previously treated with a titanium coupling agent, a silane coupling agent, or the like. Further, used in the present invention, the acid-modified polyethylene which characterizes the present invention is a polyethylene resin to which a functional group such as a carboxyl group is graft-polymerized and imparted, and examples of the functional group include: A copolymer of two or more of these functional groups may be used.

[0009]

Embedded image The density (g / cc) of the acid-modified polyethylene is:
0.90 to 0.96, MFR (g / 10 min) is 0.1
To 10 are preferred.

[0010] The polyethylene resin coloring composition of the present invention comprises:
The above components are essential components, and the mixing ratio of these components is 0 to 99.2 parts by weight of a polyethylene resin, 0.3 to 50 parts by weight of a mica pearl pigment, and 0.5 to 9 parts of an acid-modified polyethylene.
The range of 9.7 parts by weight is suitable, and more preferably 40 to 98 parts by weight of polyethylene resin, 0.3 to 50 parts by weight of mica pearl pigment and 0.5 to 5 parts of acid-modified polyethylene.
0 parts by weight. When the mica pearl pigment and the acid-modified polyethylene are in the low concentration range in this range, they are used as so-called color compounds and can be directly used for molding.
This can be used as a coloring master batch that is diluted with a resin and used. The polyethylene resin coloring composition of the present invention may be in a state where the above components are simply mixed,
Alternatively, pellets may be once melt-kneaded, and any of their production methods may be conventionally known methods.

When the amount of the mica pearl pigment in the above components is too small, the pearly feeling developed becomes insufficient. On the other hand, when the amount is too large, the molding itself becomes difficult. Also, if the amount of the acid-modified polyethylene is too small, it is difficult to obtain the effects of the present invention.
In some cases, the above-described defective appearance of the molded product occurs. The polyethylene resin coloring composition of the present invention, in addition to the above components, other optional coloring agents, antistatic agents, dispersants, ultraviolet absorbers, and the like,
Known additives can be added as needed.

[0012]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Example Maleic anhydride-based acid-modified polyethylene A (MFR:
2.0 g / 10 minutes, density: 0.94 g / cc) and acrylic acid-based acid-modified polyethylene B (MFR: 3.0 g / cc)
10 minutes, density: 0.92 g / cc) and a polyethylene resin bottle according to the following method, using seven kinds of coloring master batches containing mica pearl pigments having the composition shown in Table 1 according to the following method. Was extruded and blow-molded. Next, the appearance of the obtained bottle was observed, and the state of the weld line and the presence or absence of aggregates of mica pearl pigment were examined. The results are shown in Table 1 below.

Preparation Method of Colored Masterbatch The one having the composition shown in Table 1 was charged into a Banbury mixer,
The mixture is heated, melted and kneaded at about 170 to 190 ° C. to disperse the mica pearl pigment in the polyethylene resin and the acid-modified polyethylene. Thereafter, the mixture was pulled out into a belt shape by a mixing roll and formed into a square pellet by a square pelletizer. Further, in order to adjust the shape of the colored master batch, the extruder was melt-extruded at about 180 to 200 ° C. and granulated into round pellets.

Extrusion Blow Molding Method 10 parts by weight of the colored masterbatch prepared above was mixed with polyethylene resin (manufactured by Mitsui Petrochemical, Hyzex 6204).
B) 90 parts by weight, L / D = 20, die / core =
The mixture was put into a hopper of a molding machine of 9.3 × 9.7 / 4φ, and the mixture was heated, melted and kneaded at a set temperature of the cylinder and the die of 180 to 200 ° C., and extrusion blow-molded.

[0015]

[Table 1] Polyethylene resin: MFR: 0.3 g / 10 min Density: 0.96 g / cc ：: Weld lines are not conspicuous. X: The weld line is extremely conspicuous.

[0016]

As described above, according to the present invention, there is provided a polyethylene resin coloring composition which gives a molded article having a smooth surface and inconspicuous weld lines in the production of resin bottles used for detergents and cosmetic containers. You can do it.

Continuation of the front page (56) References JP-A-3-244671 (JP, A) JP-A-4-8742 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 23 / 00-23/36

Claims (2)

(57) [Claims] 1. A polyethylene resin of 0 to 99.2 parts by weight,
A polyethylene resin coloring composition comprising 0.3 to 50 parts by weight of mica pearl pigment and 0.5 to 99.7 parts by weight of acid-modified polyethylene. 2. The polyethylene resin colored composition according to claim 1, comprising 40 to 98 parts by weight of a polyethylene resin, 0.3 to 50 parts by weight of a mica pearl pigment, and 0.5 to 50 parts by weight of an acid-modified polyethylene.