JPH0534379B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a colored olefin resin molded article having excellent weather resistance.

(Prior Art) Olefin resins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymers are widely used in various molded products including various films and textile products. These molded bodies are usually
They are colored according to their purpose. for example,
Artificial grass is prepared by mixing several types of pigments to give it a bright green color.

Olefin resins are inherently susceptible to embrittlement and powdering due to deterioration due to heat and ultraviolet rays, and deterioration is particularly rapid when placed outdoors. Therefore, stabilizers are usually added. As a stabilizer, for example, dimethyl-1-(2-hydroxyethyl)-succinate
4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate; bis(2,2,6,6,-
Tetramethyl-4-piperidyl) sebacate;
Examples include N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylene diamine polymer. In addition, Japanese Patent Publication No. Sho 61-11255 discloses bis(phenyl-2-hydroxy-4-octyloxyphenyl ketoxime) nickel. Since such a stabilizer is added, deterioration of the resin is suppressed. However, pigments added to olefin resins for coloring may accelerate resin deterioration (thermal deterioration, photodeterioration). Previous research has revealed that there are pigments that suppress or do not promote the deterioration of olefin resins, and pigments that promote the deterioration of the resins. For example, among inorganic pigments, lead chromate pigments such as yellow; cadmium pigments such as cadmium yellow and cadmium orange (all called heavy metal pigments) suppress or prevent the deterioration of olefin resins. Not substantially promoted. However, since these are harmful to living things, there is a risk of environmental pollution if they are used. Conversely, among inorganic pigments, titanium-based pigments such as titanium white and titanium yellow; synthetic iron oxide pigments commonly known as red iron oxide and yellow iron oxide; and most organic pigments (e.g., isoindolinone yellow and other Linone pigments; phthalocyanine pigments such as phthalocyanine green and phthalocyanine blue; condensed azo pigments such as polyazo yellow) are harmless or have low toxicity to living things, but they can cause deterioration of olefin resins. promote Deterioration of the resin can be suppressed by selecting a pigment, but as for green, white, and yellow pigments, a harmless pigment that does not promote resin deterioration has not yet been developed.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks, and its purpose is to use pigments that have excellent weather resistance and low toxicity to living organisms. An object of the present invention is to provide an olefin resin molded article colored in a desired color.

(Means for Solving the Problems) The present invention aims to reduce the concentration of free transition metal ions to a predetermined concentration or lower, since deterioration of the olefin resin is accelerated due to free transition metal ions originating from pigments. The invention was completed based on the knowledge of the present invention that resin deterioration is suppressed.

Therefore, the colored olefin resin molded article of the present invention is a colored olefin resin molded article containing an olefin resin and an organic pigment and/or a surface-treated inorganic pigment. The concentration of free transition metal ions contained is 1 ppm or less based on the weight of the olefinic resin, and the surface-treated inorganic pigment is a surface coating of the inorganic pigment with silicon oxide and/or silicon hydroxide; This achieves the above objective.

The olefin resin used in the molded article of the present invention includes ordinary olefin resins such as polyethylene, polypropylene, polybutene, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer. are selected depending on the type and purpose of use.

As the pigment used for coloring, both organic pigments and inorganic pigments can be used, and any known pigments can be used. Examples of organic pigments include monoazo pigments; disazo pigments; condensed azo pigments such as polyazo yellow; anthraquinone pigments;
Perinone/perylene pigments; indico/thioindigo pigments; isoindolinone pigments such as isoindolinone yellow; phthalocyanine pigments such as phthalocyanine green and phthalocyanine blue; quinacridone pigments such as quinacridone; dioxazine pigments; carbon Examples include black. Examples of inorganic pigments include titanium oxide pigments such as titanium white and titanium yellow; iron oxide pigments containing synthetic iron oxides commonly known as red iron oxide and yellow iron oxide; chromium oxide pigments;
Examples include spinel-type fired pigments such as spinel green.

The above organic pigments usually contain trace amounts of metal ions such as copper, iron, cobalt, manganese, and titanium, which are derived from the catalysts and unreacted raw materials used when synthesizing them, or are mixed in from manufacturing equipment. present (usually 200 ppm or more). Such metal ions are transition metal ions, and thus
The presence of 200 ppm or more of transition metal ions, especially copper ions, accelerates resin deterioration. Therefore, in the present invention, organic pigments with low transition metal content are used. As such organic pigments,
A material is selected so that when the pigment is added and a molded product is prepared, the concentration of free transition metal ions in the molded product is 1 ppm or less based on the weight of the olefin resin. Usually, an organic pigment is used in which the concentration of free transition metal ions is 100 ppm or less. Such an organic pigment can be obtained, for example, by thoroughly washing a commercially available organic pigment or a synthetically obtained organic pigment in a dilute aqueous acid solution to remove metal ions. The organic pigment is usually contained in the molded article in a proportion of 2% by weight or less, although it varies depending on the type and the desired degree of coloring.

Since inorganic pigments are themselves metal compounds, in the present invention, surface-treated inorganic pigments whose surfaces are coated with silicon oxide and/or silicon hydroxide are used. Surface treated inorganic pigments are
For example, by finely dispersing ordinary inorganic pigments in water,
It is obtained by a conventional method of dropping an aqueous solution of sodium silicate, potassium silicate, etc. and a dilute aqueous sulfuric acid solution thereto and stirring. In the generated surface-treated inorganic pigment, the surface of the inorganic pigment particles is coated with silicon oxide and/or
Or it is almost uniformly coated with silicon hydroxide. The silicon oxide and/or silicon hydroxide is contained in an amount of 10 to 100 parts by weight, preferably 25 to 60 parts by weight, per 100 parts by weight of the inorganic pigment. If the amount of silicon oxide and/or silicon hydroxide is too small, the resin deterioration prevention effect will be insufficient, and if it is too much, the pigment surface will be coated thickly, so it is necessary to ensure the desired degree of coloring. requires large amounts of surface-treated inorganic pigments. Moreover, no resin deterioration preventing effect is observed in proportion to the amount of silicon oxide and/or silicon hydroxide. The surface-treated inorganic pigment produced in the reaction solution is thoroughly washed with water and dried before use. The surface-treated inorganic pigment is usually contained in the molded article in a proportion of 5% by weight or less.

These organic pigments and/or surface-treated inorganic pigments are contained in the molded article in a total amount of about 0.3 to 5% by weight.

In addition to the above-mentioned olefin resin and pigment, the molded article of the present invention usually contains an olefin resin stabilizer. As this stabilizer, known stabilizers can be used, for example those listed in the prior art section. In addition, the molded article may contain a filler, a pigment dispersant, and the like, if necessary.

The molded article of the present invention is prepared by mixing the above-mentioned olefin resin, pigment, and, if necessary, a stabilizer, a filler, and a dispersant, and using an extruder or the like in a conventional manner.
Usually, a pellet-like masterbatch containing a high concentration of pigment is prepared, and this is kneaded with an olefin resin to prepare a desired molded article.

(Function) When an organic pigment is used as a coloring pigment in the molded article of the present invention, a pigment having a low concentration of free transition metal ions in the pigment is used as described above. Since the organic pigment itself has no effect of substantially deteriorating the olefin resin, the molded article has excellent weather resistance. When using an inorganic pigment, a surface-treated inorganic pigment whose surface is coated with silicon oxide and/or silicon hydroxide is used, so a partition wall is formed between the inorganic pigment and the olefin resin. . Therefore, there are substantially no free transition metal ions in the molded article, and even if an inorganic pigment that promotes deterioration of olefin resin, such as synthetic iron oxide, is used, the deterioration of the resin will not be accelerated. There is no need to use heavy metal pigments as inorganic pigments, so there is no environmental pollution caused by cadmium or lead. Since a desired pigment can be used in this way, a molded article colored in a desired color can be obtained. This molded product has excellent weather resistance and does not pollute the environment.

(Example) The invention will be explained below with reference to examples.

Example 1 (A) Preparation of masterbatch pellets: [Masterbatch composition] Component weight parts (surface-treated inorganic pigment) Surface-treated synthetic iron oxide 21.0 (organic pigment) Copper phthalocyanine green 2.0 (free copper ion concentration: 40 ppm free) Iron ion concentration: 10ppm or less) Isoindolinone Yellow 4.0 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 10ppm or less) Polycondensed Azoretz 0.3 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 10ppm or less) Carbon Black 0.1 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 18ppm) (Dispersant) Low molecular weight polyethylene 16.4 (Stabilizer) N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl) Hexamethylene diamine polymer (MW2000) 9.8 (Olefin resin) Polypropylene pellets (melt index 4.0) 44.6 After pre-blending the above masterbatch composition,
The mixture was melt-extruded at 220 to 240°C using a vent-type extruder to form pellets to obtain a green masterbatch for polypropylene artificial turf.

In the above composition, the surface-treated synthetic iron oxide pigment is obtained by finely dispersing a zinc ferrite-based synthetic iron oxide pigment in water, adding a sodium silicate aqueous solution and a dilute sulfuric acid aqueous solution dropwise thereto in accordance with a conventional method, stirring, and then washing with hot water. , washed with water and dried. This surface-treated synthetic iron oxide contains 30 parts by weight of silicon oxide and/or silicon hydroxide based on 100 parts by weight of synthetic iron oxide as a raw material.

The above-mentioned copper phthalocyanine green pigment and polycondensed azolet pigment are synthesized by a conventional method, then finely dispersed in water, added with dilute sulfuric acid, stirred, filtered, washed with hot water, further washed with water, then dried and pulverized. obtained.

(B) Preparation and performance evaluation of olefin resin molded product (artificial turf): 1 part by weight of the masterbatch pellets obtained in section (A) and 17 parts by weight of polypropylene pellets (same as above) were kneaded, Molding temperature
Film formation was performed at 260°C. The obtained sheet was stretched about 5 times on a heated roll and split with a splitter to obtain a 3000 denier (D) yarn. This yarn was twisted at a rate of 60 times/m and flocked onto a polypropylene base fabric weighing 100 g/m ² using a tufting machine. As a result, artificial turf with a density of 17×10 ³ D/cm ² and a fiber length of 20 mm was obtained (the concentration of free transition metal ions in the fibers was 1 ppm or less based on the weight of polypropylene).

The weather resistance of the obtained artificial turf was evaluated using a weatherometer. No change in the apparent condition of the artificial turf was observed 1600 hours after the start of the test. At this time, when the rough surface of #100 sandpaper was brought into close contact with the artificial turf surface and rubbed 10 times with a load of 1 kg, no powdering of the resin was observed.

Comparative example 1 [Masterbatch composition] Parts by weight of components (inorganic pigment) Zinc ferrite-based synthetic iron oxide 16.3 (organic pigment) Copper phthalocyanine green 2.1 (Free copper ion concentration: 800 ppm Free iron ion concentration: 90 ppm or less) Isoindolinone yellow 4.2 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 10ppm or less) Polycondensed Azoret 0.3 (Free copper ion concentration: 110ppm Free iron ion concentration: 55ppm) Carbon black 0.1 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 18ppm) (Dispersant) Low molecular weight polyethylene 17.0 (Stabilizer) Copolymer of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 1,2-dibromoethane Coalescence (MW2000) 9.8 (Olefin resin) Polypropylene pellets (Melt index 4.0) 51.3 As described above, an inorganic pigment with no surface treatment and an organic pigment with a high concentration of free transition metal ions were used, and Example 1 was carried out. Masterbatch pellets having substantially the same color tone were obtained. In the above composition, the copper phthalocyanine green pigment and the polycondensed azolet pigment were used as they were without being treated with dilute sulfuric acid in Example 1.

Example 1 Using this masterbatch pellet
A weathering test was conducted on artificial turf (the concentration of free transition metal ions in the fibers is 1 ppm or more based on the weight of polypropylene) prepared almost in accordance with Example 1. Powdering was observed in the scratch test using sandpaper in section (B). In the following Examples and Comparative Examples, the time at which powdering was observed is defined as the weather resistance time measured by a weatherometer.

Example 2 [Masterbatch composition] Parts by weight of ingredients (organic pigment) Copper phthalocyanine green 3.0 (Free copper ion concentration: 40 ppm Free iron ion concentration: 10 ppm or less) Isoindolinone yellow 11.2 (Free copper ion concentration: 10 ppm or less Free iron ion Concentration: 10ppm or less) Carbon black 0.2 (Free copper ion concentration: 10ppm or less Free iron ion concentration: 18ppm) (Dispersant) Low molecular weight polyethylene 13.4 (Stabilizer) N,N'-bis(2,2,6,6- Tetramethyl-4-piperidyl)hexamethylene diamine polymer (MW2000) 9.8 (Olefin resin) Polypropylene pellets (melt index 4.0) 59.4 Masterbatch pellets were prepared according to Example 1 using the above composition. Then, 1 part by weight was kneaded with 24 parts by weight of polypropylene pellets (same quality as above) to prepare artificial turf. The weather resistance time measured by a weatherometer was 1300 hours.

Example 3 [Masterbatch composition] Parts by weight of components (surface-treated inorganic pigment) Surface-treated spinel-type fired green pigment 18.9 Surface-treated synthetic iron oxide 16.2 (dispersant) Low molecular weight polyethylene 17.6 (stabilizer) N,N'-bis( 2,2,6,6-tetramethyl-4-piperidyl)hexamethylene diamine polymer (MW2000) 9.8 (Olefin resin) Polypropylene pellets (melt index 4.0) 37.2 Using the above composition, the same procedure as in Example 1 was carried out. Masterbatch pellets were prepared. In the above composition,
The surface-treated spinel type fired green pigment is obtained by treating a titanium-zinc-cobalt-nickel based spinel type fired pigment with an aqueous sodium silicate solution according to Example 1(A). Surface-treated synthetic iron oxide is also obtained in the same manner as in Example 1 (A).

Using this masterbatch pellet, add 1 part by weight to polypropylene pellets (same quality as above).
Parts by weight were kneaded to prepare artificial turf according to Example 1 (B). The weather resistance time according to weatherometer is
It was 1700 hours.

Example 4 [Masterbatch composition] Parts by weight of ingredients (organic pigment) Copper phthalocyanine green 20.0 (Free copper ion concentration: 45 ppm Free iron ion concentration: 10 ppm or less) Carbon black 0.2 (Free copper ion concentration: 10 ppm or less Free iron ion concentration: 18ppm) (Dispersant) Low molecular weight polyethylene 20.2 (Stabilizer) N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine polymer (MW2000) 9.8 (Olefin resin) Polypropylene pellets (melt index 4.0) 49.8 Using the above composition, masterbatch pellets were prepared according to Example 1, and 1 part by weight of the pellets was kneaded with 19 parts by weight of polypropylene pellets (same quality as above). , prepared artificial turf. The weather resistance time measured by a weatherometer was 1200 hours.

Comparative example 2 Free copper ion concentration 800 ppm, free iron ion concentration
The same as Example 2 except that 70 ppm copper phthalocyanine green (not subjected to washing treatment) was used. The weather resistance time measured by a weatherometer was 1000 hours.

Comparative Example 3 [Masterbatch composition] Parts by weight of components (inorganic pigment) Spinel-type fired green pigment 14.5 Synthetic iron oxide 12.5 (Dispersant) Low molecular weight polyethylene 13.5 (Stabilizer) N,N'-bis(2,2,6, 6-tetramethyl-4-piperidyl)hexamethylene diamine polymer (MW2000) 9.8 (Olefin resin) Polypropylene pellets (melt index 4.0) 49.4 As described above, using an inorganic pigment without surface treatment, Masterbatch pellets having substantially the same color tone as in Example 3 were obtained. Using this masterbatch pellet, artificial turf was prepared according to Example 1 (B). The weather resistance time according to weatherometer is
It was 1100 hours.

Comparative example 4 Free copper ion concentration 600 ppm, free iron ion concentration
The same as Example 4 except that 80 ppm copper phthalocyanine green (without washing treatment) was used. The weather resistance time measured by a weatherometer was 900 hours.

(Effects of the Invention) As described above, according to the present invention, an olefin resin molded article that is colored in a desired color and has excellent weather resistance can be obtained. Since this molded article uses pigments that are non-toxic or low-toxic to living organisms, it does not pollute the environment. Such molded bodies are particularly useful for products installed outdoors, such as artificial turf, agricultural films, and miscellaneous ropes.

Claims (1)

[Scope of Claims] 1. A colored olefin resin molded article containing an olefin resin and an organic pigment and/or a surface-treated inorganic pigment, the colored olefin resin molded article comprising: a free transition metal ion contained in the colored olefin resin molded article; A molded article, wherein the concentration is 1 ppm or less based on the weight of the olefin resin, and the surface-treated inorganic pigment is a surface coating of an inorganic pigment with silicon oxide and/or silicon hydroxide. 2 The surface-treated inorganic pigment is the inorganic pigment 100
The molded article according to claim 1, which contains 10 to 100 parts by weight of silicon oxide and/or silicon hydroxide. 3. The molded article according to claim 1, wherein the free transition metal ions are mainly derived from an organic pigment. 4 The concentration of free transition metal ions in the organic pigment is
The molded article according to claim 3, which has a content of 100 ppm or less. 5. The molded article according to claim 1, wherein the organic pigment is a phthalocyanine pigment. 6. The molded article according to claim 1, wherein the inorganic pigment is an iron oxide pigment. 7. The molded article according to claim 1, wherein the transition metal ion is a copper ion.