JPH0687982A - Colored polyolefinic resin composition - Google Patents

Abstract

PURPOSE:To obtain a colored polyolefinic resin composition capable of preventing moldings from yellowing even in preservation for a long period. CONSTITUTION:The polyolefinic resin composition comprises 0.1-50 pts.wt. pearly pigment made of mica and 0.001-10 pts.wt. polysiloxane based on 100 pts.wt. polyolefinic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yellowing-resistant polyolefin resin coloring composition containing a mica pearl pigment.

[0002]

2. Description of the Related Art Conventionally, a mica (electric mother) pearl pigment has been used as a colorant in order to give a pearly feel to a polyolefin resin molded product in terms of design. Extrusion molding or injection molding is used as a coloring molding method, and extrusion molding can obtain colored moldings such as sheets, blow bottles and films, and injection molding widely provides moldings such as home appliances and sundries. Has been done.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Generally, a stabilizer such as an antioxidant is added to a polyolefin resin in order to prevent oxidative deterioration of the resin. However, phenolic compounds in antioxidants such as B
When HT (2,6-di-tert-butyl-4-methylphenol) is added to the polyolefin resin, the above phenolic compound reacts with heat, light, humidity, nitrogen oxides, etc. during long-term storage. However, the hue of the polyolefin resin or its molded product may change from white to yellow or pink. Furthermore, when colored with a mica pearl pigment,
There is a problem in that the yellowing of the resin or the molded product is strongly promoted due to the effect of titanium coating the mica surface. Therefore,
An object of the present invention is to provide a polyolefin resin coloring composition in which yellowing of a molded article is prevented even during long-term storage.

[0004]

The above object can be achieved by the present invention described below. That is, the present invention is based on 100 parts by weight of polyolefin resin.
It is a polyolefin resin coloring composition containing 50 parts by weight and 0.001 to 10 parts by weight of polysiloxane.

[0005]

The present inventor has conducted various studies on the formulation of the colorant for preventing the yellowing of the above-mentioned polyolefin resin, and as a result, the polyolefin resin is mixed with a mica pearl pigment and a specific amount of polysiloxane for coloring. As a result, they have found that the yellowing of the polyolefin resin or its molded product is prevented, and the present invention has been completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The polyolefin resin used in the present invention is a conventionally known polyolefin resin for extrusion molding, injection molding, and the like. For example, polyethylene resin (specific gravity: 0.91 to 0.97, MFR: 0.05 to
50), polypropylene resin (specific gravity: 0.89 to 0.9)
1, other MFR: 0.1-50) and other thermoplastic resins and mixtures thereof.

The mica-made pearl pigment used in the present invention is a fine mica having a laminated structure, and a pearl pigment in which the surface of mica particles is treated with titanium oxide in order to further develop a pearly feeling. Is. These pearl pigments have an average particle size of about 1 to 200 μm, and such mica pearl pigments can be easily obtained from the market and used in the present invention. These mica pearl pigments are about 0.1 to 100 parts by weight of the polyolefin resin.
It is used at a ratio of 50 parts by weight.

The polysiloxane used in the present invention and characterized in the present invention is a polysiloxane which is cured by heating and / or a suitable catalyst to form a hydrophobic coating.
For example, alkylhydrogenpolysiloxane such as methylhydrogenpolysiloxane and ethylhydrogenpolysiloxane, organopolysiloxane containing a reactive group such as vinyl group or epoxy group are particularly effective, and most preferable is methylhydrogenpolysiloxane. Genpolysiloxane.

These can be obtained from the market and used in the present invention as described above. The amount of these polysiloxanes used is about 0.001 to 10 parts by weight, preferably 0.01 to 100 parts by weight, based on 100 parts by weight of the polyolefin resin.
5 parts by weight. The amount of polysiloxane used is 0.001
If it is less than 10 parts by weight, yellowing of the polyolefin resin aimed at by the present invention cannot be prevented. On the other hand, if it is more than 10 parts by weight, molding is not easy, and
It is not preferable because it hinders the dispersion of the mica-made pearl pigment and causes many agglomerates of the mica-made pearl pigment, resulting in poor appearance of the molded product.

The polyolefin resin coloring composition of the present invention may be in the state of simply mixing the above components, or may be in the form of pellets obtained by once melt-kneading and granulating. For example, the carrier resin such as polyolefin, the pearl pigment and the polysiloxane may be kneaded and granulated by a conventionally known method such as a Banbury mixer or an extruder. Further, when the content of the mica pearl pigment and polysiloxa in the carrier resin is low, it can be used as a so-called color compound and can be used as it is for coloring molding. It can be used as a colored masterbatch to be diluted with a resin. In addition to the above components, the polyolefin resin coloring composition of the present invention may contain known additives such as any other colorant, antistatic agent, dispersant, and ultraviolet absorber, if necessary.

[0011]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. Yellowing Degree Evaluation Method The coloring compositions prepared in the following Examples and Comparative Examples were placed in a 2 liter desiccator, and 200 ml of 28% ammonia water was injected into this desiccator, and the mixture was sealed while being exposed in this ammonia gas atmosphere. At that time, a fluorescent lamp is irradiated from above (illuminance of the sample surface is about 2,000 Lux) and the temperature is maintained at room temperature for 100 hours. The yellowing degree (ΔYI) of the coloring composition is measured according to JISK7103 (Plasticity Yellowness and Yellowing Test Method) using a colorimeter.

Example 1 Polyethylene resin (Showa Denko, Shorex 500)
3, specific gravity: 0.944, MFR: 0.3 g / 10 minutes) 9
7.98 parts by weight, mica pearl pigment (average particle size: 2
(0 μm) 2.0 parts by weight and methyl hydrogen polysiloxane 0.02 parts by weight were uniformly mixed by a Henschel mixer, and the resulting mixture was extrusion-molded at a temperature of 200 ° C. by an extruder to obtain colored pellets. 90 × 50 × 2 of the above pellets using an injection molding machine (manufactured by JSW, 50Z)
A mm-shaped plate-shaped molded product was molded (molding condition: temperature 230 ° C., mold temperature: 40 ° C.). Next, the degree of yellowing of the above-mentioned molded product was measured according to the above-mentioned yellowing degree evaluation method. The results are shown in Table 1 below.

Example 2 Polyethylene resin (Showa Denko, Shorex 500)
3, specific gravity: 0.944, MFR: 0.3 g / 10 minutes) 9
7.5 parts by weight, mica pearl pigment (average particle size: 20
μm) 2.0 parts by weight and methyl hydrogen polysiloxane 0.5 parts by weight were uniformly mixed with a Henschel mixer, and then evaluated in the same manner as in Example 1.

Example 3 Polypropylene resin (Mitsui Toatsu Chemicals, Mitsui Noblen JH-G, specific gravity: 0.91, MFR: 4 g / 10 minutes) 9
7.98 parts by weight, mica pearl pigment (average particle size: 2
(0 μm) 2.0 parts by weight and methyl hydrogen polysiloxane 0.02 parts by weight were uniformly mixed with a Henschel mixer, and then evaluated in the same manner as in Example 1.

Example 4 Polypropylene resin (Mitsui Toatsu Chemicals, Mitsui Noblen JH-G, specific gravity: 0.91, MFR: 4 g / 10 min) 9
7.5 parts by weight, mica pearl pigment (average particle size: 20
μm) 2.0 parts by weight and methyl hydrogen polysiloxane 0.5 parts by weight were uniformly mixed with a Henschel mixer, and then evaluated in the same manner as in Example 1.

Comparative Example 1 Polyethylene resin (Showa Denko, Sholex 500
3, specific gravity: 0.944, MFR: 0.3 g / 10 minutes) 9
8.0 parts by weight and mica pearl pigment (average particle size: 2
2.0 parts by weight (0 μm) were uniformly mixed with a Henschel mixer, and evaluated in the same manner as in Example 1 below.

Comparative Example 2 Polypropylene resin (Mitsui Toatsu Chemicals, Mitsui Noblen JH-G, specific gravity: 0.91, MFR: 4 g / 10 minutes) 9
8.0 parts by weight and mica pearl pigment (average particle size: 2
2.0 parts by weight (0 μm) were uniformly mixed with a Henschel mixer, and evaluated in the same manner as in Example 1 below.

[0018]

[Table 1]

[0019]

As described above, according to the present invention, by using the coloring composition of the present invention, it is possible to obtain a polyolefin-colored molded product having no yellowing.

Claims (2)

[Claims] 1. A polyolefin resin coloring composition comprising 0.1 to 50 parts by weight of a mica pearl pigment and 0.001 to 10 parts by weight of polysiloxane per 100 parts by weight of a polyolefin resin. 2. The polyolefin resin coloring composition according to claim 1, wherein the polysiloxane is methyl hydrogen polysiloxane.