JPH0116265B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin polymer composition for coating with improved weather resistance. More specifically, the present invention relates to a polyolefin polymer composition containing an antioxidant, an ultraviolet absorber and/or a light stabilizer as a resin stabilizer, and a carboxyl group. The object of the present invention is to provide a polyolefin-based polymer composition which is blended with a containing ethylene polymer, suppresses leaching of a resin stabilizer, and has excellent weather resistance. Conventionally, polyolefin polymers are materials with excellent chemical resistance, durability, and processability. Taking advantage of these advantages, polyolefin polymers are coated on metals by extrusion methods, powder coating methods, etc., and are used to prevent corrosion of the metals. It is widely used to add sexiness and decoration. However, when such coatings are used outdoors, they are susceptible to photodeterioration due to ultraviolet rays, solar heat, rainfall, moisture, oxygen and ozone, active gases such as sulfur dioxide and nitrogen oxides, day and night temperature cycles, and dew condensation. Since it is exposed to a harsh environment where thermal deterioration and chemical deterioration coexist, the photosensitivity decreases significantly after short-term outdoor exposure, and it has the disadvantage of causing cracking, which greatly limits its range of use. Conventionally, methods for preventing such deterioration phenomena include adding a suitable ultraviolet absorber, light stabilizer, or a weathering agent using a combination thereof (for example, Japanese Patent Publication No. 45-30567, Japanese Patent Publication No. 46 −
31733, Japanese Patent Publication No. 54-39019) have been proposed. However, when these weathering agents are simply blended, their compatibility with the polyolefin polymer is low, and the weathering agent migrates to the coating surface and oozes out in a short period of time, causing sweating and solid precipitation, which significantly deteriorates the appearance. Since it causes damage, there is a limit to its amount. In particular, when coating by powder coating, various additives are added to improve the grindability of the polyolefin polymer and to prevent thermal oxidative deterioration during coating processing, so the amount of weathering agent added is As a result, sufficiently satisfactory weather resistance cannot be obtained, and a solution to this problem is desired. As a result of intensive research into a formulation that overcomes the above-mentioned drawbacks and suppresses oozing of the resin stabilizer, the present inventors have surprisingly found that the weather resistance of polyolefin-based polymers is Although it is inferior to the conventional method, by blending a polyolefin polymer with a resin stabilizer and a carboxyl group-containing ethylene polymer, it is possible to easily obtain a high degree of weather resistance that could not be achieved with conventional methods. They discovered this and arrived at the present invention. That is, the present invention provides: 1 0.01 to 1.0 parts by weight of an antioxidant and 0.01 to 1.0 parts by weight of an ultraviolet absorber and/or light stabilizer as a resin stabilizer to 100 parts by weight of a polyolefin polymer.
Polyolefin composition 2 comprising 4.99 parts by weight and 0.5 to 50 parts by weight of a carboxyl group-containing ethylene polymer. Polyolefin composition 3 according to Item 1. Polyolefin composition 4 according to Item 1 above, wherein the antioxidant is a hindered phenolic antioxidant. Polyolefin composition according to Item 1, wherein the carboxyl group-containing ethylene polymer is an ionomer resin. provide something. As a result, the oozing of the resin stabilizer is greatly suppressed, and as a result, the amount of resin stabilizer blended can be increased, and the stability of the stabilizer is excellent, and deterioration phenomena such as weather resistance are substantially prevented for a long period of time. The present invention provides a polyolefin-based polymer composition. In addition, polyolefin polymers are nonpolar resins and usually have poor adhesion to metals, but the composition of the present invention containing a carboxyl group-containing ethylene polymer also improves adhesion to metals. It has the effect of improving corrosion resistance. The polyolefin polymer used in the present invention refers to polyethylene polymerized by medium/low pressure method or high pressure method, ethylene polymer with ethylene content of 90% by weight or more, or ethylene polymer with 10% by weight or less of propylene or butene. 1, hexene-1,3-methyl-1
- Copolymers with other α-olefins such as butene, octene-1, and 4-methyl-1-pentene, vinyl copolymers with vinyl acetate, etc., acrylic copolymers with methyl methacrylate, etc., or these. It means a mixture containing the above polymer as the main component and other resins such as propylene, polybutadiene, polyisobutylene, butyl rubber as a resin modifier, and ethylene/vinyl acetate copolymer with a vinyl acetate content of 20% by weight or more. It also includes mixtures of ethylene and carbon atoms with a carbon number of 4 to 10.
A copolymer with α-olefin is most preferred because it has excellent resin properties. The resin stabilizer used in the present invention consists of an antioxidant, an ultraviolet absorber, and/or a light stabilizer, and these are known suitable ones. Butyl p-cresol, 4,4'-thiobis-(3-methyl-6-tertiarybutylphenol), 4,
4'-Butylidenebis-(6-tertiarybutyl-
3-methylphenol), pentaerythrityl-
Tetrakis[3-(3,5-ditertyabutyl-4-hydroxyphenyl)]propionate,
2,2'-methylenebis(6-tertiarybutyl-
4-methylphenol), octadecyl 3-(3.
Hindered phenol-based antioxidants such as 5-ditertyabutyl-4-hydroxyphenyl) propionate, and thiodipropionate acid-based antioxidants such as dilaurylthiodipropionate and distearylthiodipropionate. , hindered phenolic antioxidants are preferred. In particular, when coating by powder coating, the coating processing temperature may be 200℃ or higher, and the most preferable antioxidant is pentaerythrityl tetrakis Butyl-4-hydroxyphenyl) propionate is recommended. Further, as the ultraviolet absorber or light stabilizer, for example, 2-n-octylthio-4,6-di(4-
Hydroxy-3′・5′-diobutyl)phenoxy-
1,3,5-triazine, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-
Benzophenones such as n-octoxybenzophenone, 2,2'-hydroxy-4-methoxybenzophenone, or 2-(2'-hydroxy-5'-
methylphenyl)benzotriazole, 2-
(2'-Hydroxy-3'-tertiarybutyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-tertiarybutylphenyl)-5 -Chlorobenzotriazole, 2-(2'-Hydroxy-3',5'-ditersialyamylphenyls)benzotriazole, 2-
(2'-hydroxy-4-n-octoxyphenyl)
UV absorbers of benzotriazole derivatives such as benzotriazole and/or 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-(4'-toluoyloxy)-2,2.
6,6-tetramethylpiperidine, 4-benzoyloxy-2,2-dimethyl-6,6-diethylpiperidine, 4-acetoxy-2,2,6,6-
Tetramethylpiperidine, 4-n-butyroyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexanoyl-2,2,6,6-
Tetramethylpiperidine, bis(2, 2, 6, 6
-tetramethylpiperidine)oxalate, bis(2,2,6,6-tetramethylpiperidine)malonate, bis-(2,2,6,6-tetramethylpiperidine)succinate, bis(2,2,
6,6-tetramethylpiperidine) fumarate,
Bis-(2,2,6,6-tetramethylpiperidine) sebacate, bis-(2,2,6,6-tetramethylpiperidine) terephthalate, bis-
Piperidine derivatives such as (2,2,6,6-tetramethylpiperidine)hexahydroterephthalate and 1,3,8-triaza-7,7,9.
9-tetramethyl-3-n-hexyl-spiro(4,5)decane-2,4-dione, 1,3,8
-triaza-7,7,9,9-tetramethyl-3
-n-octyl-spiro(4.5)decane-2.
4-dione, 1,3,8-triaza-7,7.
9,9-tetramethyl-3-n-decyl-spiro(4,5)decane-2,4-dione, 1,3,8
-triaza-7,7-dimethyl-9,9-diethyl-3-n-decyl-spiro(4,5)decane-
It is a light stabilizer such as a spiro compound such as 2,4-dione, and these can be used alone or in combination. Therefore, when these antioxidants are used in combination with an ultraviolet absorber and/or a light stabilizer, a synergistic effect of improving weather resistance can be obtained, which is most preferable. The blending amount of the resin stabilizer is 0.02 to 5 parts by weight, preferably 0.05 to 2.5 parts by weight, based on 100 parts by weight of the polyolefin polymer. Among them, the antioxidant is blended in an amount of 0.01 to 1.0 parts by weight. If the amount of the resin stabilizer is less than 0.02 parts by weight, no resin stabilizing effect can be obtained, and if the amount is more than 5 parts by weight, the resin stabilizer is generally expensive and economically disadvantageous. In the present invention, the carboxyl group-containing ethylene polymer refers to ethylene and α,β-ethylenically unsaturated mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, mesaconic acid, etc. A method of copolymerizing an acid, citraconic acid, etc., a method of graft copolymerizing the above α,β-ethylenically unsaturated mono- or dicarboxylic acid or its anhydride to polyethylene or an ethylene copolymer, or a method of graft copolymerizing a polyethylene or an ethylene copolymer with - a method of copolymerizing monomers such as esters, anhydrides, and amides of ethylenically unsaturated carboxylic acid derivatives and then converting the monomers to free carboxylic acids;
For example, by saponifying the ester part of an ethylene/methyl methacrylate copolymer containing 5 to 35 parts by weight of methyl methacrylate with a hydroxide such as sodium hydroxide, and then reacting it with an acid such as sulfuric acid. can get. Further, there are ethylene-based ionomer resins (trade name: Copolene, manufactured by Asahi Dow Co., Ltd.) obtained by replacing the hydrogen of the carboxyl group obtained in this manner with sodium, lithium, zinc, magnesium, etc. Among these, ethylene-based ionomer resins are most preferred because of their excellent resin properties. The amount of carboxyl group-containing ethylene polymer is based on 100 parts by weight of polyolefin polymer.
The amount is 0.5 to 50 parts by weight, preferably 1 to 25 parts by weight. If the amount is less than this amount, the expected effects of the present invention will not be obtained, and no improvement in weather resistance will be observed.
In addition, if the blending amount exceeds 50 parts by weight, problems may arise in compatibility with the polyolefin polymer, the characteristics of the polyolefin polymer for coating may be lost, and it may become uneconomical to blend more than necessary. Not. The composition of the present invention is prepared by mixing a polyolefin polymer, a resin stabilizer, and a carboxyl group-containing ethylene polymer using a known suitable method such as a V-type blender or a Henschel mixer.
It is uniformly dispersed using ordinary kneading equipment such as an extruder, Banbury mixer, or kneader. However, when blending the resin stabilizer, a master batch is used in which the resin stabilizer is blended in advance into polyolefin polymer powder at a high concentration and granulated. It is preferable to mix it more uniformly. At this time, other additives such as a peroxide decomposer, a copper damage inhibitor, a grindability improver, and a pigment may also be added at the same time. The composition of the present invention can be easily molded into various molded products such as films, sheets, pipes, etc. by known methods.
For example, the composition of the present invention can be applied mechanically to molded products such as agricultural films, cover sheets, water-stop sheets, protective pipes, construction safety light covers, bottle containers, transport boxes for agricultural and fisheries products, extrusion coatings such as electric wire protection pipes, etc. Alternatively, it is made into a powder using a solvent, etc., and used for many outdoor applications such as coating pipes, coating fences, and coating balls for road signs by powder coating called the fluidized dipping method and electrostatic powder coating method. . Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded. In addition, all parts in Examples and Comparative Examples indicate parts by weight. Example 1 Ionomer resin (manufactured by Asahi Dow Co., Ltd., trade name, Copolene D200) as a carboxyl group-containing ethylene polymer was added to 100 parts of high-pressure polyethylene (manufactured by Asahi Dow Co., Ltd., trade name, Asahi Dow Polyethylene M-6525). 5 parts of octadecyl-3 (3,5-ditertyabutyl-4-hydroxyphenyl) propionate (manufactured by Ciba Geigy, trade name, Irganox) as an antioxidant was added to the polyethylene powder in advance.
1076) 1% by weight, bis(2.2.
3 parts by weight of 6,6-tetramethylpiperidyl) sebacate (manufactured by Sankyo Co., Ltd., trade name, Sanol LS-770) and 2% by weight of cyanine green as a coloring agent.
Mix 2.5% by weight of Irgazin yellow with 12 parts of a masterbatch containing a pelletized resin stabilizer and coloring agent in a blender to form a 40mm
The mixture was kneaded and pelletized at 130°C to 160°C using a φ extruder. The pellets were then used to coat metal according to the following method, and the leaching properties and weather resistance of the resin stabilizer were tested. The results are shown in Table 1. Coating on metal, thickness pre-degreased with trichlorethylene
Place the 0.8mm cold rolled steel plate on the compression molding machine and
Using a spacer of mm thickness, temperature 160℃, pressure 5
A test piece was prepared under the condition of Kg/cm ² . Leakage test: After leaving the test piece in a constant temperature and humidity environment of 23℃ and 65% relative humidity for two months, the glossiness of the sample surface (60
The glossiness retention rate (percentage of the glossiness immediately after coating) is determined. Weather resistance test: Peel off a 0.5 mm thick film from the test piece and use a Sunshine Weather Meter (manufactured by Suga Test Instruments Co., Ltd., WE-
A 2,500-hour test was conducted using the SUN-HC model). The tensile elongation at break of the coating was measured every 300 hours of the test, and the test time at which the elongation retention rate (percentage of the tensile elongation at break of the untested piece) was 50% was determined and defined as the weathering time. Examples 2 to 4 In the formulation of Example 1, as shown in Table 1, the ultraviolet absorber 2-(2-hydroxy-3'.
5′-ditertyabutylphenyl)-5-chlorobenzotriazole (manufactured by Ciba Geigy, trade name, Tinuvin 327) or light stabilizer 1, 3, 6
Triazo-7,7,9,9-tetramethyl-3-
n-octylspiro(4.5)-decane-2.4
-Dione (manufactured by Sankyo Co., Ltd., trade name, Sanol 772) and these in combination were used to test the exudation properties and weather resistance of the resin stabilizer according to the method of Example 1.
The results are shown in Table 1. In this way, even when other ultraviolet absorbers or light stabilizers were used, leaching of the resin stabilizer was suppressed and good weather resistance was obtained. Control example A press sheet was prepared using only the high-pressure polyethylene used in Example 1 or the ionomer resin used in Example 1 without adding a weathering agent, and its weather resistance was tested under the same conditions as Example 1. The results were are shown in Table 1. Comparative Example 1 A composition obtained by removing the resin stabilizer from the formulation of Example 1 was tested for weather resistance according to the method of Example 1. The results are shown in Table 1. Comparative Examples 2 to 5 A composition was prepared in which the ionomer resin was removed from the formulation of Example 1, and the exudation property and weather resistance of the resin stabilizer were tested according to the method of Example 1. The results are shown in Table 1. Compared to the Examples, the resin stabilizer oozed out more intensely, the gloss retention rate decreased significantly, and the weather resistance was also insufficient. Example 5 In the formulation of Example 1, for 100 parts of polyethylene, 2 parts of ionomer resin, 0.05 part of Irganox 1076, an antioxidant, and Sanol, a light stabilizer.
A composition was prepared by adding 0.05 part of LS-770 to the same coloring formulation as in Example 1, and the exudation property and weather resistance of the resin stabilizer were tested in accordance with the method of Example 1. The results are shown in Table 1. Despite the small amount of resin stabilizer,
Good weather resistance was obtained. Comparative Examples 6 and 7 In the formulation of Example 5, a composition was prepared in which only an antioxidant or only a light stabilizer was blended as a resin stabilizer, and a resin stabilizer was added according to the method of Example 1. The leaching and weathering resistance of the material was tested. The results are shown in Table 1. Good weather resistance cannot be obtained if the resin stabilizer is an antioxidant or a light stabilizer alone. Comparative Example 8 A composition obtained by removing the ionomer resin from the formulation of Example 5 was tested for exudation and weather resistance of the resin stabilizer according to the method of Example 1. The results are shown in Table 1. Despite the small amount of resin stabilizer,
The oozing phenomenon is observed and the weather resistance is low.

【table】

[Table] Example 6 An ionomer resin (Asahi Dow
Co., Ltd. (trade name: Copolene D200)) and high-pressure polyethylene powder (Asahi Dow Co., Ltd., trade name: Asahi Dow Powder Polyethylene M-6525) were added in advance to 5 parts of pentaerythrityltetrakis [3-
(3,5-ditertyabutyl-4-hydroxyphenyl) propionate (manufactured by Ciba Geigy,
(trade name: Irganox 1010) 1% by weight and bis(2,2,6,6-tetramethylpiperidyl) sebacate (manufactured by Sankyo Co., Ltd., trade name: Sanol) as a light stabilizer.
LS770) 2% by weight, 2-(2
-Hydroxy-3',5'-dithyabutylphenyl) 5-chlorobenzotriazole (manufactured by Ciba Geigy, trade name Tinuvin 327) 2% by weight, cyanine green 2% by weight as coloring agents, irgazine yellow 2.5% by weight , a pelletized resin stabilizer containing 0.5% by weight of red red iron and 12 parts of a masterbatch containing a coloring agent were mixed in a blender to prepare a composition according to the method of Example 1, and the resin stabilizer was exuded. and weather resistance. The results are shown in Table 2. Examples 7 to 9 In the formulation of Example 6, an ethylene/acrylic acid copolymer with an acrylic acid content of 8% by weight or 20% by weight (manufactured by Dow Chemical Company, commercial product) was used instead of the ionomer resin as the carboxyl group-containing ethylene polymer. name, EAA-455 or EAA-X033)
5 parts or a polymer obtained by grafting 0.5% by weight of maleic acid and maleic anhydride onto polyethylene.
A composition was prepared in the same manner as in Example 6, except that 10 parts of the resin stabilizer was used, and the leaching properties and weather resistance of the resin stabilizer were tested. The results are shown in Table 2. Examples 10, 11 In the formulation of Example 6, the vinyl acetate content was 8 instead of the copolymer of ethylene and octene-1.
The same method as in Example 6 was used, except that ethylene/vinyl acetate copolymer or ethylene and butene-1 copolymer (manufactured by Mitsui Petrochemicals Co., Ltd., trade name, Neozex 2540R) was used. A composition was prepared according to the following and tested for leaching and weather resistance of the resin stabilizer. The results are shown in Table 2. Comparative Example 9 A composition was prepared by removing the ionomer resin from the formulation of Example 6, and the exudation property and weather resistance of the resin stabilizer were tested according to the method of Example 6. The results are shown in Table 2.

[Table] Example 12 100 parts of high-pressure polyethylene (manufactured by Asahi Dow Co., Ltd., trade name Asahi Dow Polyethylene M-6525) and polyisobutylene (manufactured by Ciel Corporation, trade name Vistanecx ML)
5 parts and 10 parts of an ionomer resin (manufactured by Asahi Dow Co., Ltd., trade name Copolene D200) and pentaerythrityl-tetrakis [3-(3,5-diterthyabutyl-)] were added to the polyethylene powder as an antioxidant in advance. 1% by weight of propionate (manufactured by Ciba Geigy, trade name Irganox 1010) and bis(2-4-hydroxyphenyl) as a light stabilizer.
3% by weight of 2,6,6-tetramethylpiperidyl) sebacate (manufactured by Sankyo Co., Ltd., trade name Sanol LS-770), 2-(2-hydroxy-
2% by weight of 3', 5'-diterthyabutylphenyls) 5-chlorobenzotriazole (manufactured by Ciba Geigy, trade name Tinuvin 327), 2% by weight of cyanine green as a coloring agent, 2.5% by weight of Irgazine yellow.
% by weight, 0.5% by weight of red red iron and 2% by weight of oleic acid amide as a grinding improver, pelletized, and well mixed with 12 parts of a masterbatch containing a resin stabilizer, a coloring agent, and a grinding improver in a blender, 130℃~160℃ using 40mmφ extruder
The pellets were kneaded under the following conditions to form pellets, and the pellets were mechanically pulverized using a Victor Mill VP-1 type pulverizer (manufactured by Hosokawa Tekko Co., Ltd.) and passed through a 40-mesh sieve to prepare powdered polyethylene. This powder composition
A 0.8 mmt cold rolled steel plate was coated by the fluidized dipping method to obtain a coated steel plate with a film thickness of 400 μm and a good appearance. The conditions for powder coating using the fluidized immersion method are as follows: A steel plate is coated in an electric furnace preheated to 350°C for 30 minutes.
Preheat for 4 minutes, then immerse it in a flowing powder tank for 4 seconds, remove it from the tank, and heat it to 200°C.
The film was introduced into an oven heated to 300°C and heated for 3 minutes to form a smooth film. When the obtained coated steel sheet was tested for exudation of resin stabilizers, etc. according to the method of Example 1, the gloss retention rate after 2 months was 90°C, and when the weather resistance was tested, the weather resistance was The test time was over 2,500 hours, and it had excellent weather resistance. FIG. 1 shows the weather resistance of Example 12, and FIG. 2 shows the change over time in the exudation of the resin stabilizer, etc. Comparative Example 10 A composition was prepared by removing the ionomer resin from the formulation of Example 12, powdered polyethylene was prepared according to the same method as in Example 12, and a steel plate was coated to improve the exudation properties and weather resistance of resin stabilizers, etc. tested for sex. As a result, the gloss retention rate after two months was 8%, indicating that the resin stabilizer etc. were oozing out heavily.
The weather resistance was 1300 hours, and the weather resistance was poor even though a large amount of resin stabilizer was blended. Figure 1 shows the weather resistance of Comparative Example 10, and Figure 2 shows the exudation of the resin stabilizer and changes over time. As described above, conventional compositions in which a resin stabilizer is simply blended with a polyolefin polymer do not exhibit sufficient light resistance, and due to the problem of leaching of the resin stabilizer, However, in the composition of the present invention, the exudation of the resin stabilizer is suppressed and good gloss is maintained for a long period of time, so it is possible to increase the amount of the resin stabilizer blended. It is recognized that the heat resistance is significantly superior.

[Brief explanation of drawings]

Figure 1 is an example of weather resistance, and is a diagram showing the relationship between weather resistance test time and tensile elongation retention of the coating sheet. Figure 2 is an example of exudation of additives such as resin stabilizers, and is a diagram showing the relationship between days and gloss retention. It is a relationship diagram of rates. In the figure, A is a conventional composition simply containing an antioxidant, an ultraviolet absorber, and a light stabilizer, and B is a composition of the present invention.

Claims (1)

[Claims] 1 100 parts by weight of a polyolefin polymer, 0.01 to 1.0 parts by weight of an antioxidant as a resin stabilizer, 0.01 to 4.99 parts by weight of an ultraviolet absorber and/or light stabilizer, and 0.5 to 0.5 parts by weight of a carboxyl group-containing ethylene polymer.
A polyolefin composition comprising 50 parts by weight.