JPH0246059B2 - PUROPIRENKEIJUSHISEIKEIHINNOHYOMENSHORIHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for surface treatment of propylene-based resin molded articles, and more specifically, the present invention relates to a method for surface treatment of propylene-based resin molded articles, and more specifically, by treating the surface of the propylene-based resin molded article with low-temperature plasma, the paintability, printability and This invention relates to a method for improving adhesive properties, etc. Propylene resin has mechanical and thermal properties,
It is a relatively inexpensive resin with excellent moldability, so it is widely used in various fields, but it is also used in paints, inks,
Due to its poor adhesion to adhesives, its use in applications requiring painting, printing, and adhesion is limited, and improvements in its adhesion are being considered. An effective method for this purpose is to improve the adhesion of the molded product surface by low-temperature plasma surface treatment using oxidizing gas, but even this plasma treatment method cannot sufficiently achieve the adhesion required in actual applications. The current situation is that we are not satisfied. In view of the current situation, the present invention provides a method for surface treatment of propylene-based resin molded products using low-temperature plasma, which can impart advanced adhesive performance by subjecting the propylene-based resin to a specific treatment in advance. . The surface treatment method for a propylene resin molded article of the present invention involves treating the surface of a molded article made of a melt-kneaded product of a propylene resin and an organic peroxide in an amount of 0.005 to 0.2 parts by weight per 100 parts by weight of the resin. It is characterized by plasma treatment. The propylene resin used here is a substantially crystalline propylene homopolymer, a random or block copolymer of propylene and α-olefin containing 1 to 30% by weight of ethylene or other α-olefin, etc. be. In addition, the organic peroxide used here usually has a peroxide bond (-O-O
-) hydroperoxides, dialkyl peroxides, dialperoxides,
Selected from ketone peroxides, alkyl peroxy esters, peroxydicarbonates, etc., preferably, for example, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5 -dimethyl-2,
5-di-(t-butylperoxy)hexane, 2,
Examples include 5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3, 1,3-bis-(t-butylperoxyisopropyl)benzene, and the like. Two or more of these organic peroxides may be used in combination. The amount of the organic peroxide added to the propylene resin is 0.005 to 100 parts by weight of the resin.
0.2 parts by weight, preferably 0.01 to 0.1 parts by weight,
Particularly preferably 0.02 to 0.05 parts by weight. If the amount added is less than 0.005 parts by weight, the effect of improving the adhesion of plasma-treated molded products will not be sufficient;
Even if the amount exceeds 1 part by weight, not only is the effect of increasing the amount not observed, but also the molecular cleavage of the propylene resin is excessive, resulting in a decrease in the mechanical strength of the molded product. To obtain a melt-kneaded product from the propylene resin and the organic peroxide, add the organic peroxide in the amount added to the propylene resin, mix uniformly with a V blender or high-speed mixer, and then mix using a uniaxial extruder. ,
Using a twin-screw kneading extruder, Banbury type mixer, etc.,
It is common to melt and knead at ℃ to form pellets.
Both components may be directly fed into a molding machine and melt-molded. The melt flow rate (MFR) of the propylene resin is not particularly limited, but
It is preferable that the value according to JIS K7210 is 0.1 to 20 g/10 minutes, and the MFR of the melt-kneaded product with organic peroxide
is preferably 1 to 100 g/10 minutes, particularly 5 to 40
g/10 minutes is preferred. MFR of melt-kneaded material is 1
If it is less than g/10 minutes, the moldability will be poor and the effect of improving the adhesion of the molded article will not be sufficient. Also, 100g/10
If the temperature exceeds 50%, the mechanical strength of the molded product will decrease. The propylene resin may include low to high density polyethylene, plastics such as ethylene-vinyl acetate copolymer, elastomers such as ethylene-propylene copolymer rubber, styrene-butadiene block copolymer rubber, etc., as long as the characteristics of the present invention are not impaired.
Inorganic fillers such as talc, calcium carbonate, and glass fibers, colorants, antioxidants, neutralizing agents, ultraviolet stabilizers, ultraviolet absorbers, crystallization nucleating agents, and the like may be added as desired. The molded product may be molded by any method such as injection molding, extrusion molding, blow molding, etc., and is not limited to a specific product. Low-temperature plasma treatment involves exciting a low-pressure oxidizing gas such as oxygen or a gas mixed with nitrogen, air, argon, carbon gas, chlorine gas, etc. using high-frequency discharge, microwave discharge, etc. to generate an active gas. , this is done by bringing it into contact with the surface of the molded article. Processing conditions are not particularly limited, but usually the pressure is 0.1 to 10 torr and the processing time is 5 seconds to 15 minutes. The effects of the present invention will be clarified by Examples and Comparative Examples below. Examples 1 to 7, Comparative Examples 1 to 7 Various homopolypropylene or ethylene propylene block copolymers (manufactured by Mitsubishi Yuka Co., Ltd.) shown in Table 1 and 2,6-di-t-butyl-4 as an antioxidant -Methylphenol (manufactured by Yoshitomi Pharmaceutical Co., Ltd.,
BHT) 0.2 parts by weight, organic peroxide 1,3
-bis-(t-butylperoxyisopropyl)
Benzene (manufactured by Kayaku Nouri Co., Ltd., Perkadox)
14) in a predetermined amount (0 to 0.05 parts by weight), and in Example 7 and Comparative Example 7, ethylene propylene rubber (manufactured by Japan EP Rubber Co., Ltd., EPO2P, Moony Clay
After uniformly mixing 10% by weight of ML ₁₊₄ (100°C) = 24) with a high-speed mixer, the mixture was melt-kneaded and extruded at 230°C using a 50O single-screw extruder (manufactured by Thermoplastics) to form pellets. Adhesion test pieces were made using an injection molding machine (N made by Japan Steel Works, Ltd.).
−100) obtained by 100mm×100mm×3mmt
This is the board. Low-temperature plasma surface treatment was performed using a microwave plasma treatment device (TMZ-9602B manufactured by Tokyo Shibaura Electric Co., Ltd.) using oxygen gas at a flow rate of 400 c.c./min and a pressure of 0.5 torr.
Processed for 10 seconds at an output of 400W. The adhesion test was conducted using the following method. After plasma treatment, a two-component curing urethane paint (manufactured by Nippon B Chemical Co., Ltd., R-263) was spray-coated to a film thickness of approximately 100 to 120μ, and then heated at 90℃ for 40 minutes.
Bake for a minute. Next, a 10 mm wide cut was made in the coating film, and a strip of coating film was peeled off from one end, folded back in the opposite direction, and subjected to a 180° peel test (using Shimadzu Autograph P-100, pulling speed 20 mm/min).
Did. The results are shown in Table 1. Those within the scope of the present invention (Examples 1 to 7) all had extremely high peel strength, whereas those outside the scope of the present invention (Comparative Example 1)
~7) Peel strength is low in all cases. Table 1 also shows the MFR of the pellets, and the addition of organic peroxide improves the peel strength as well as the MFR. However, as seen in Comparative Example 2, the MFR was Although the peel strength was large (MFR was increased during polymerization), the peel strength was not as great as on the left, indicating that the addition of organic peroxide is essential. 【table】

Claims (1)

[Claims] 1. A propylene-based resin molded article comprising a melt-kneaded product of a propylene-based resin and 0.005 to 0.2 parts by weight of organic peroxide per 100 parts by weight of the resin, the surface of which is subjected to low-temperature plasma treatment. surface treatment method.