JPH06313076A - Propylene-based resin composition - Google Patents

Abstract

PURPOSE:To obtain a propylene-based resin composition capable of giving inks curable by UV lights or molded articles excellent in adhesiveness to coatings without primer treatments and without using any special additive. CONSTITUTION:(1) This propylene-based composition comprises 100 pts.wt. crystalline polypropylene-based resin added with 0.01-0.3 pts.wt. phosphorus-based antioxidant having >=175 deg.C melting point. (2) The antioxidant having >=175 deg.C melting point in the propylene-based resin composition is tris(2,4-di-t-butylphenyl) phosphite, bis(2,6-di-t-butyl-methylphenyl) pentaerythritol diphosphite or a mixture of both compounds.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a propylene resin composition. More specifically, a propylene-based resin composition comprising a crystalline propylene-based resin and a specific phosphorus-based antioxidant, which is used for pretreatment of the surface of a molded product in printing or coating with an ultraviolet curable ink or paint. The present invention relates to a propylene-based resin composition capable of obtaining a molded article having excellent adhesiveness to ink or paint without a certain primer treatment.

[0002]

2. Description of the Related Art Generally, a crystalline propylene-based resin is a resin which is susceptible to oxidative deterioration, so that it is general to add an antioxidant to the resin before use. As such an antioxidant, a phosphorus-based antioxidant is a useful antioxidant because of its high antioxidant performance and high effect of improving the hue of a molded article. However, if a molded product obtained by molding a composition containing a phosphorus-based antioxidant having a melting point of less than 175 ° C. is printed or coated with UV-curable ink or paint, the molded product deteriorates due to irradiation with ultraviolet rays. As a result, there is a drawback that the adhesiveness with ink or paint is significantly deteriorated. Conventionally, in order to improve this drawback, when printing or painting with an ultraviolet curable ink or paint, it has been necessary to perform a primer treatment as a pretreatment step.

Further, in order to improve the adhesiveness of a molded article obtained by using the propylene-based resin without a primer treatment with an ultraviolet-curable ink or paint, methacrylic acid, methyl acrylate, methyl methacrylate, acetic acid. A composition has been proposed in which a copolymer obtained by copolymerizing a monomer such as vinyl or styrene with ethylene is added to a propylene resin (Japanese Patent Laid-Open No. 62-201955). However, the primer treatment method requires a primer treatment step, and the method of adding a special copolymer has the drawbacks that the moldability of the obtained composition is deteriorated and the cost is increased.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention printed using an ultraviolet curable ink or paint without a primer treatment and without using a composition containing a special copolymer. Alternatively, the inventors have earnestly studied in order to obtain a propylene-based resin composition capable of obtaining a molded article having excellent adhesion to ink or paint in coating. As a result, a composition obtained by adding a specific amount of a phosphorus-based antioxidant having a specific melting point to a propylene-based resin is used as an ink or ink in printing or painting with an ultraviolet curable ink or paint without a primer treatment. It was found that a molded product having excellent adhesiveness with a paint can be provided, and the present invention was completed based on this finding. As is clear from the above description, the object of the present invention is to provide a molded article excellent in adhesiveness with an ultraviolet curable ink or paint without primer treatment and without using a special additive. A propylene-based resin composition is provided.

The present invention has the following configuration. (1) 100 parts by weight of crystalline propylene resin, 175 ° C
The phosphorus-based antioxidant having a melting point of 0.01 to 0.
A propylene-based resin composition containing 3 parts by weight. (2) The phosphorus-based antioxidant having a melting point of 175 ° C. or higher is tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl-methylphenyl) pentaerythritol. -The propylene-based resin composition according to the above item 1, which is ludiphosphite and a mixture thereof.

The propylene-based resin used in the present invention is a homopolymer of propylene, a copolymer of propylene as a main component with propylene and an α-olefin other than propylene, for example, an ethylene-propylene block copolymer,
Acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, maleic anhydride, etc. for ethylene-propylene random copolymer, ethylene-propylene-1-butene terpolymer, etc. and the homopolymer and the copolymer. Examples thereof include a graft copolymer obtained by graft-copolymerizing the organic acid or its ester, or a mixture of two or more kinds thereof, and the melt flow rate (MFR) of the propylene resin is not particularly limited. But usually 0,
01 to 100 g / 10 minutes, preferably 0.5 to 50 g / 1
The 0 minute one is used.

Examples of the phosphorus-based antioxidant having a melting point of 175 ° C. or higher used in the present invention include tris (2,4-di-t-butylphenyl) phosphite and bis (2,6-di-t-butyl-methyl). Phenyl) pentaerythritol diphosphite or mixtures thereof can be mentioned. The addition amount of the phosphorus-based antioxidant is propylene-based resin 1
It is 0.01 to 0.3 parts by weight with respect to 00 parts by weight. If the addition amount is less than 0.01 part by weight, the effect of improving the adhesiveness with the ultraviolet curable ink or paint will not be exhibited, and the addition amount will be 0.
Even if added in excess of 3 parts by weight, the effect of improving the adhesiveness with ink or paint is saturated, and no further improvement in the effect is observed, which is uneconomical.

In the composition of the present invention, various additives usually added to crystalline polyolefins such as antioxidants such as phenol type, thioether type, phosphorus type melting point less than 175 ° C., light stabilizer, Heavy metal deactivator (copper damage inhibitor), clarifying agent, nucleating agent, lubricant, antistatic agent, antifogging agent, antiblocking agent, non-dripping agent, radical generator such as peroxide, flame retardant, Flame retardant aids, pigments, halogen scavengers, dispersants or neutralizers for metal soaps, organic or inorganic antibacterial agents, inorganic fillers (eg talc, mica, clay, wollastonite, zeolite) , Kaolin, bentonite, perlite, diatomaceous earth, asbestos, calcium carbonate, aluminum hydroxide, magnesium hydroxide, silicon dioxide, titanium dioxide, zinc oxide, magnesium oxide, sulfur Zinc, barium sulfate, calcium silicate, aluminum silicate, glass fiber, potassium titanate, carbon fiber, carbon black, graphite and metal fiber), coupling agent (eg, silane-based, titanate-based, boron-based, aluminate-based) , Zircoaluminate, etc.) to the extent that the above-mentioned inorganic filler or organic filler (for example, wood flour, pulp, waste paper, synthetic fiber, natural fiber, etc.) surface-treated is not impaired. Can be used together.

In the composition of the present invention, for example, a predetermined amount of a phosphorus-based antioxidant having a melting point of 175 ° C. or higher in crystalline propylene-based resin and the above-mentioned various additives usually added to crystalline propylene-based resin are usually used. Mixing device such as Henschel mixer (trade name), super mixer, ribbon blender, Banbury mixer, etc.,
Using a conventional single-screw extruder, twin-screw extruder, Brabender or roll, the melt-kneading temperature is 150 ° C to 300 ° C, preferably 18
It can be obtained by melt-kneading and pelletizing at 0 ° C to 270 ° C. The obtained composition is used for producing a desired molded article by various molding methods such as an injection molding method, an extrusion molding method and a blow molding method.

[0010]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods used in Examples and Comparative Examples were as follows. 1) Ultraviolet irradiation test An ultraviolet irradiation device (UVC-1 manufactured by Ushio Inc.) was prepared using the predetermined test pieces obtained in each of the examples and comparative examples.
81) is used to irradiate ultraviolet rays under the conditions of an ultraviolet wavelength of 300 nm, an ultraviolet irradiation intensity of 100 w / m ² , a treatment time of 3 seconds, and a distance of 100 mm between an ultraviolet ray generation source and a test piece to be treated, and the degree of discoloration of the test piece, The degree of deformation and surface gloss were visually determined and evaluated according to the following criteria. ⊚: No discoloration, neither deformation nor surface gloss change. ◯: Slightly discolored and deformed, and slightly changed gloss, but no problem in practical use. X: Discoloration, deformation, and remarkable change in gloss were observed, and practically unusable.

2) Ink Adhesion Test RI was applied to the predetermined test pieces obtained in each Example and Comparative Example.
Using a tester, 0.3 cc of UV-curable ink manufactured by Toyo Ink Mfg. Co., Ltd. was subjected to offset printing by UV irradiation, and a 2 mm grid was placed on the printed surface of the obtained test piece. Stick Cellophane Tape (trademark) on,
Rapid peeling was performed at a 45-degree angle, the peeled state was visually observed, and the ink adhesion was evaluated according to the following criteria. A: There is no peeling at all. ◯: Some peeling is observed at the corners of the grid, but there is no practical problem. Δ: Peeling was clearly observed at the corners of the grid and there was a problem in practical use. X: Remarkable peeling is recognized and practically unusable.

Examples 1 to 9 and Comparative Examples 1 to 6 As crystalline propylene resin, 100 parts by weight of non-stabilized powdery crystalline propylene homopolymer of 2 g / 10 minutes in MFR are listed in Table 1 below. The phosphorus compound of
Tris (2,4-di-t-butylphenyl) phosphite (phosphorus compound I, melting point 185 ° C., Ciba-Gaigi I
rgafos168 ™), bis (2,6-di-t-butyl-)
Methylphenyl) pentaerythritol diphosphite (phosphorus compound II, melting point 240 ° C., Mark PEP-36 (trademark) manufactured by Asahi Denka Co., Ltd.), bis (2,4-di-t-butylphenyl) pentaeryth Lithol diphosphite (phosphorus compound III, melting point 165 ° C, Mark PEP-24G (trademark) manufactured by Asahi Denka Co., Ltd.), distearyl pentaerythritol diphosphite (phosphorus compound IV, melting point 4
Mark PEP-8 (trademark) manufactured by Asahi Denka Kogyo Co., Ltd. and tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylene diphosphinate (phosphorus compound)
V, melting point 75 ° C, SANDOSTAB P-EPQ (trademark) manufactured by Sand Co., Ltd., and 0.1% by weight of calcium stearate as an additional component in the same table are put in a Henschel mixer (trade name) and mixed with stirring for 5 minutes. After that, caliber 40mm
Was melt-kneaded at 230 ° C. with a twin-screw extruder to prepare pellets. Further, as Comparative Examples 1 to 6, pellets were obtained by melt-kneading in accordance with Examples 1 to 9 except that a predetermined amount of each phosphorus-based antioxidant shown in Table 1 below was added.
Each of the pellets obtained in each of Examples and Comparative Examples was extruded at a cylinder temperature of 230 ° C. and a die temperature of 250 ° C. using a T-die extruder having a diameter of 40 mm to form a sheet. The sheet was cut into a size having a length of 100 mm, a width of 10 mm and a thickness of 1.0 mm, and then one side of the cut sheet was subjected to corona discharge treatment so that the surface wetting tension was 40 dynes / cm,
After aging at 60 ° C. for 48 hours to prepare a test piece, an ultraviolet irradiation test and an ink adhesion test were carried out. The results are shown in Table 1.

Examples 10 to 13 and Comparative Examples 7 to 10 As a crystalline propylene resin, 100 parts by weight of a propylene-ethylene copolymer having an MFR of 4 g / 10 min and an ethylene content of 8% by weight are described in Table 1 below. 0.1% by weight of calcium stearate as an additional component and an additional component shown in the same table is put into a Henschel mixer (trade name), and the mixture is stirred and mixed for 5 minutes, and then is mixed with a twin-screw extruder having a diameter of 30 mm.
Melt kneading treatment was carried out at 230 ° C. to obtain pellets. Further, as Comparative Examples 7 to 10, Examples 10 to 1 except that the phosphorus-based antioxidant shown in Table 1 described later was added in the addition amount shown in the same table.
Pellets were obtained according to 3. Using each of the pellets obtained in the Examples and Comparative Examples, Examples 1-9
A predetermined test piece was prepared in accordance with the above, and an ultraviolet irradiation test and an ink adhesion test were performed. The results are shown in Table 1.

[0014]

[Table 1]

As is clear from Table 1, the melting point is 175.
Molded articles obtained from the compositions of Examples using phosphorus-based antioxidants having a temperature of ℃ or above were free from discoloration, deformation and surface gloss change in the UV irradiation test without primer treatment. It is also found in the adhesion test that the ink has excellent ink adhesion.

[0016]

INDUSTRIAL APPLICABILITY The composition of the present invention, even though it uses a crystalline propylene-based resin, can be used as a primer even when printed or painted with an ultraviolet curable ink or paint.
It is possible to give a molded product that does not undergo discoloration, deformation, gloss failure, and has a high adhesive strength with ink or paint without treatment.
It can be suitably used in the product field for printing or painting with an ultraviolet curable ink or paint.

Claims (2)

[Claims] 1. To 100 parts by weight of a crystalline propylene resin, 1 is added.
0.01% phosphorus-based antioxidant having a melting point of 75 ° C. or higher
~ 0.3 parts by weight of a propylene resin composition. 2. A phosphorus-based antioxidant having a melting point of 175 ° C. or higher is tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl-methylphenyl) penta. The propylene-based resin composition according to claim 1, which is erythritol diphosphite and a mixture thereof.