JPH04164966A - Resin composition containing flaky iron oxide - Google Patents

Abstract

PURPOSE:To obtain a decorative resin composition having brilliant stable metallic luster due to platy iron oxide it contains by dispersing coarse platy iron oxide particles having metallic luster in a resin. CONSTITUTION:Coarse platy iron oxide particles having metallic luster (MIO) (preferably particles which have a mean particle diameter of 30mum or larger, preferably 50-150mum, and do not substantially contain particles of a diameter of 20mum or smaller) are dispersed in a resin (any of a thermoplastic resin, a thermosetting resin, or an elastic resin such as synthetic rubber) to give the title composition. This composition has a highly decorative feature with brilliant metallic luster due to the MIO dispersed in the resin, is stable to resin as compared with a powder of metal, such as Al or Ni, and is free from change with time, e.g. the deterioration of the resin and the loss of the metallic luster.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition containing platy synthetic iron oxide. More specifically, the present invention relates to a resin composition useful for decorative materials and various light-reflecting functional materials that utilize the metallic luster of plate-like iron oxide with developed crystals.

(Prior Art) When using various resin molding materials, coloring materials such as pigments are generally added.

In such coloring materials, aluminum, nickel, zinc,
By adding metal powder pigments such as copper-zinc alloy or stainless steel to the resin, the resin material may be given a metallic color.

However, metal powders are generally active towards resins,
Metal powder is not used as it is because it often causes deterioration of the resin; instead, metal powder is coated with a certain type of material. On the other hand, the production of fine metal powder not only requires special technology, but also causes phenomena such as the metal surface being oxidized and losing its metallic luster.
Despite the demand for durable metallic resins, there are almost no coloring materials that meet this demand.

(Problems to be Solved by the Invention) Under the current circumstances, the development of a resin composition having stable metallic luster has a wide range of uses due to its design properties.

By the way, plate-like iron oxide, which is an iron oxide pigment, is mica-like iron oxide (Micaceous Iron Oxide).
It is known as "MIOJ" hereinafter, and is characterized by its blackish-purple color and plate-like and flaky shapes.Due to its morphology, the plate-like particles are oriented parallel to the coating surface. Its fine powder is used as an anti-rust pigment to form a strong coating film.It is also known that mica-like iron oxide with a large particle size has a metallic luster.
Conventionally, since it was obtained by crushing natural products, it not only contained fine particles but also had an irregular shape, and these particles adhered to the surface of coarse particles, resulting in a weak metallic luster as a whole.

In view of the above problems, the present inventors conducted intensive research on resin compositions with beautiful metallic luster, and found that when the resin contains specific coarse-grained plate-like iron oxide, dispersed plate-like iron oxide The present invention was completed based on the discovery that a resin composition with a unique three-dimensional effect and a high-class feel, which is diffusely reflected and sparkles, can be obtained.

(Means and effects for solving the problem) That is, the plate-shaped iron oxide-containing resin composition provided by the present invention is characterized in that coarse-grained MIO having metallic luster is dispersed in the resin. It is something to do.

The present invention will be explained in detail below.

The MIO according to the present invention is α-iron oxide, which is a so-called mica-like iron oxide having a hexagonal plate shape as described above, and may be either a natural product or a synthetic product, but a synthetic product is preferable. This is particularly preferred since the shape and grain size of the single crystal can be controlled.

Such MIO is generally well known as a rust-preventive pigment, and fine particles are used, but in the present invention, it must be coarse particles with metallic luster. Therefore, if it is a natural product, it must be well classified and the fine particles adhering to the washed surface must be removed. Here, coarse particles mean an average particle size of 30- or more, preferably 50- or more.
It is preferable that the particle size is in the range of ~150 IIm and substantially free of fine particles of 201M or less.

The metallic luster is especially excellent for particles with many single crystals, and the color tone is reddish brown for particles as small as 1-1, and as they grow larger they turn reddish-purple, dark purple, silver, and black, gradually becoming more vivid metallic luster. have In particular, when the average particle diameter exceeds 30 mm, the metallic luster becomes more colorful. This is because when light hits plate-shaped iron oxide, the amount of light reflected increases.
If the particle diameter is smaller than 30, which gives a more sparkling feeling, the amount of reflected light will also be smaller and the metallic luster will be weaker.

In particular, when dispersed in resin, 20I! Since the presence of fine particles of m or less causes a so-called dull color and reduces the metallic luster, the MIO must be coarse-grained as described above. In the present invention, the MIO further includes the above-mentioned MIO
It may also be coated with fine titanium dioxide particles.

Mica coated with titanium dioxide is known as a high-grade pigment that exhibits a so-called pearlescent luster, but MIO coated with a titanium dioxide film also has a unique pearlescent luster that is different from that of titanium dioxide coated mical.

Such MIO has been proposed, for example, by the present inventors in Japanese Patent Application No. 1-2
According to the method disclosed in No. 66919, iron powder can be obtained by subjecting it to alkaline hydrothermal treatment at a desired oxygen partial pressure. According to this production method, the alkali is not consumed, so the raw materials are only iron powder and oxygen, and no by-products are produced, so the production process is extremely simple, and has an industrial advantage over comparisons that were conventionally difficult. It is possible to produce large plate iron oxide.

Next, the resin that can be used in the resin composition according to the present invention is not particularly limited, and may be either a thermoplastic resin or a thermosetting resin. Alternatively, an elastic resin such as synthetic rubber may be used.

Typical thermoplastic resins include polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyethylene, polypropylene, polystyrene, (meth)acrylic resin, chlorinated polyolefin resin, fluororesin,
Polyacetal resin, polyamide resin, polyimide resin, polyester resin, polycarbonate resin, polysulfone resin, ionomer resin, silicone resin or AA
Examples include copolymer resins such as SAs resin, BS resin, As resin, ABS resin, and EVA resin, and they may also be one or more composite resins such as polymer alloys.

Examples of the thermosetting resin include phenol resin, epoxy resin, unsaturated polyester resin, polyurethane resin, melamine resin, urea resin, diallyl phthalate resin,
Examples include silicone resin.

Examples of synthetic rubber include SBR, BR, IR, NBR, urethane rubber, silicone rubber, and various elastic resins.

In the present invention, the ratio of platy iron oxide mixed with the resin varies depending on the purpose of use, but the ratio of MI to 100 parts by weight of the resin is
oo, 5 to 20 parts by weight, preferably 1 to 15 parts by weight.

If the blending ratio of plate iron oxide is less than 0.5 parts by weight, sufficient metallic luster cannot be obtained, and if it is 20 parts by weight or more, an effect commensurate with the amount added cannot be obtained.

In the present invention, such a resin composition is obtained by blending MIO with a resin, but in some cases, MIO may also be combined with titanium oxide, zinc oxide, barium sulfate, calcium carbonate extender pigments, organic or inorganic coloring pigments, plasticizers, crosslinkers, etc. agent,
Additives such as fillers, flame retardants, antioxidants, UV stabilizers, heat stabilizers, or antistatic agents can be used in combination.

Further, such a resin composition may be molded by known means.

Thus, the resin composition according to the present invention has a more vivid metallic luster due to the plate-like iron oxide contained therein, and can provide a resin composition with good design.

〔Example〕

Hereinafter, the present invention will be specifically explained based on Examples.

Various synthetic MIOs used in the examples were manufactured according to the following manufacturing examples. 3 parts iron powder, 5 parts water, and 15-5 m NaOH in a stainless steel autoclave.

Filled with 1 part kg HzO equivalent and heated to 210℃ under stirring.
The oxidation reaction was carried out for 2 to 6 hours at a temperature of 5 MPa or higher.

After the reaction was completed, the product was taken out and separated into solids, washed with methanol, and dried to recover a powder with metallic luster. X-ray diffraction of both powders showed α-Fe.
There was only a single phase of O, and when observed with an electron microscope, all particles were found to be hexagonal plate-shaped, well-ordered single-crystal particles.

(1) Preparation of resin composition Vinyl chloride resin (Zeon 103EP: Nippon Zeon ■)
100 parts by weight MIO10
Part by weight DOP 50 parts by weight Stearic acid 2 parts by weight After kneading the resin composition with the above blending ratio for 5 minutes using two rolls, it was taken out into a sheet with a thickness of 0.5 mm, and then 2 cm x 5
A test piece was cut into a rectangle of c+m.

(2) Evaluation Evaluate the appearance of the test piece in three stages using the following method. The evaluation results are shown in Table 1.

◎-The dispersed metallic luster is sparkling and vivid, and it is rich in beauty and decoration.

〇-Slightly inferior in metallic luster, but aesthetically pleasing and decorative.

×- It is colored brown and has no metallic luster, and is neither aesthetic nor decorative.

Examples 1 to 3 and Comparative Example 1 Test pieces of resin compositions were prepared in the same manner as in Example 1, except that the particle size of the plate-like iron oxide was changed.

Table 1 Example 4 Fine titanium dioxide particles were added to MrO used in Example 1.
A test piece of the resin composition was prepared in the same manner as in Example 1 except that MIO coated with 10.5 wt% of MIO was used. Met.

Example 5 High density polyethylene resin powder (melt index 0
．． 9) 100 parts by weight, 0.2 parts by weight of calcium stearate, 0.0 parts by weight of antioxidant. 2 parts by weight and 0.2 parts by weight of heat stabilizer
5 parts by weight of various MIOs were added to each part by weight.

Next, the polyethylene resin compositions of each blending ratio were kneaded for 5 minutes using a test roll with a front roll surface temperature of 160°C and a back roll surface temperature of 120°C, and then kneaded to a thickness of 0.
It was taken out in the form of a 5-inch sheet.

The obtained sheet was cut into a 3 cm x 5 cm rectangle to prepare a test piece.

When this test piece was observed using the same evaluation method as above, Table 2
The results were obtained.

The test pieces were tested for heat resistance by placing them in a gear opener kept at 200°C, and all showed good thermal stability.

Table 2 Note (1) Titanium dioxide coated MIO used in Example 4 Note (
2) Natural MIO classified and washed with water [Effect of the invention] The resin composition according to the present invention exhibits a sparkling metallic luster due to the MIO dispersed in the resin, and is rich in design.

The plate-shaped iron oxide according to the present invention is more stable with respect to resin than metal powders such as aluminum and nickel, and provides a stable resin composition that does not undergo changes over time such as resin deterioration or loss of metallic luster. , it can be said that the value of the molded product in use is much greater than that of conventional molded products.

Applicant: Nippon Chemical Industry Co., Ltd. Agent: Patent Attorney Tadashi Takahata

Claims (1)

[Claims] 1. Coarse-grained plate-like iron oxide (MI
A resin composition characterized by dispersing O). 2. Plate iron oxide has an average particle size of 30 μm or more and 20 μm
The plate-shaped iron oxide-containing resin composition according to claim 1, which is a coarse-grained synthetic MIO substantially free of fine particles of m or less. 3. The plate-shaped iron oxide-containing resin composition according to claim 1 or 2, wherein the plate-shaped iron oxide is coated with fine titanium dioxide particles. 4. The content of plate iron oxide is 1 per 100 parts by weight of resin.
The plate-shaped iron oxide-containing resin composition according to claim 1 or 2, wherein the iron oxide-containing resin composition is 15 parts by weight.