JPH0140750B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for bonding metal and polyolefin resin. More specifically, there is a method of fusing a polyolefin modified with an unsaturated carboxylic acid or its derivative, the main component of which is an ethylene-α-olefin copolymer, which is polymerized in the gas phase under a specific catalyst with an epoxy resin interposed on the metal. Regarding. Polyolefin resin has excellent corrosion resistance against acids, alkalis, solvents, etc., solvent resistance, and electrical insulation properties, so it is used for lining steel pipes, drums, etc., coating electric wires, machinery and equipment, and protecting glass. It is widely used. In particular, coating metal surfaces has been actively carried out, and various processing methods have been developed. However, since polyolefin is nonpolar, its adhesion to metals is extremely poor. In order to improve this drawback, there is a method in which polyolefin powder is applied to the metal surface heated to a temperature significantly higher than the melting point of polyolefin, and a part of the resin is decomposed to create polar groups and improve adhesion to the metal. A method of blending a substance that improves adhesion such as polyisobutylene or butyl rubber, or using a polyolefin modified with an unsaturated carboxylic acid such as maleic anhydride or acrylic acid or a derivative thereof as an intermediate layer between the metal and the polyolefin, or using the polyolefin itself as an intermediate layer between the metal and the polyolefin. Attempts have been made to use the adhesive as an alternative to strengthen the adhesion between the two, but the adhesive strength, salt water resistance, environmental stress cracking resistance, etc. are still not sufficiently satisfactory for practical use. In addition, there is a method (Japanese Patent Publication No. 48-29301, Japanese Patent Publication No. 53-4880) in which a film of thermosetting epoxy resin is formed on the metal surface, heat-cured, and then coated with polyolefin modified with unsaturated carboxylic acid. be. However, when the present inventors investigated such a method, it was found that the adhesive strength decreased in a short time when it came into contact with an aqueous solution containing an electrolyte such as seawater or saline, and the salt water resistance and environmental stress cracking resistance ( (hereinafter referred to as ESCR), etc., and is not used for applications such as seawater pipes. An object of the present invention is to provide an adhesive method for obtaining a laminate of polyolefin and metal that not only has high adhesive strength to metal but also has excellent water resistance, salt water resistance, and ESCR. That is, the present invention provides a method for bonding a polyolefin and a metal, in which the metal is bonded with an epoxy resin in the presence of a catalyst consisting of a solid substance containing magnesium, titanium, and/or vanadium, and an organoaluminum compound. , the density obtained by copolymerizing ethylene and α-olefin having 3 to 12 carbon atoms in a gas phase state substantially free of solvent is 0.890 to 0.960 g/cc, and the melt index is 0.1 to 10.0 g/10 min. This is a method of fusing a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof, the main component of which is an ethylene-α-olefin copolymer. In the present invention, in the presence of a catalyst consisting of a solid material containing magnesium and titanium and/or vanadium and an organoaluminum compound as a polyolefin, ethylene and a −Density obtained by copolymerizing olefin is 0.890 to 0.960
g/cc, melt index is 0.1~10.0g/
A polyolefin modified with an unsaturated carboxylic acid or a derivative thereof whose main component is a 10-minute ethylene-α-olefin copolymer is used. The polyolefin of the present invention whose main component is an ethylene-α-olefin copolymer modified with an unsaturated carboxylic acid or a derivative thereof is an ethylene-α-olefin copolymer modified with an ethylene-α-olefin copolymer in the gas phase in the presence of the specific catalyst. The polymer may be grafted with an unsaturated carboxylic acid or a derivative, or a polyolefin blended with another polyolefin containing the ethylene-α-olefin copolymer as the main component, grafted in the same manner as above, or a conventional polyolefin with unsaturated carboxylic acid or derivatives. It refers to a blend of a polyolefin modified with a saturated carboxylic acid or a derivative thereof and the above-mentioned unmodified ethylene-α-olefin copolymer. The polyolefins to be blended with the above ethylene-α-olefin copolymer include low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene obtained by high, medium and low pressure methods,
Examples include poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, propylene/1-butene copolymer, and mixtures thereof. Below, ethylene used in the present invention and α-
A method for producing an olefin copolymer will be explained. The catalyst system used is a combination of a solid substance containing magnesium, titanium and/or vanadium, and an organoaluminium compound, such as magnesium metal, magnesium hydroxide, magnesium carbonate, magnesium oxide, magnesium chloride, etc. Magnesium, etc., as well as double salts, double oxides, carbonates, chlorides, hydroxides, etc. containing magnesium atoms and metals selected from silicon aluminum and calcium. Examples include those in which a titanium compound and/or vanadium compound is supported by a known method on an inorganic solid support, such as one treated or reacted with a compound, an aromatic hydrocarbon, or a halogen-containing substance. Examples of the above oxygen-containing compounds include organic oxygen-containing compounds such as water, alcohol, phenol, ketone, aldehyde, carboxylic acid, ester, and acid amide, and inorganic oxygen-containing compounds such as metal alkoxides and metal oxychlorides. be able to. Examples of sulfur-containing compounds include organic sulfur-containing compounds such as thiols and thioethers, sulfur dioxide, sulfur trioxide,
Examples include inorganic sulfur compounds such as sulfuric acid. Examples of aromatic hydrocarbons include various monocyclic and polycyclic aromatic hydrocarbon compounds such as benzene, toluene, xylene, anthracene, and phenanthrene. Examples of the halogen-containing substance include compounds such as chlorine, hydrogen chloride, metal chlorides, and organic halides. Examples of the titanium compound and/or vanadium compound include halides, alkoxy halides, alkoxides, and halogenated oxides of titanium and/or vanadium. Preferred titanium compounds are tetravalent titanium compounds and trivalent titanium compounds, and specific examples of tetravalent titanium compounds include the general formula Ti(OR) _o X _4-o
(Here, R represents an alkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms, and X represents a halogen atom. n is 0≦n≦4.) Titanium tetrachloride is preferable. , titanium tetrabromide,
Titanium tetraiodide, monomethoxytrichlorotitanium, dimethoxydichlorotitanium, trimethoxymonochlorotitanium, tetramethoxytitanium, monoethoxytrichlorotitanium, diethoxydichlorotitanium, triethoxymonochlorotitanium, tetraethoxytitanium, monoisopropoxytrichlorotitanium, diiso Propoxydichlorotitanium, triisopropoxymonochlorotitanium, tetraisopropoxytitanium, monoptoxytrichlorotitanium,
Examples include diphenoxydichlorotitanium, monobenxytrichlorotitanium, monophenoxytrichlorotitanium, diphenoxydichlorotitanium, triphenoxymonochlorotitanium, and tetraphenoxytitanium. Trivalent titanium compounds include titanium trihalides obtained by reducing titanium tetrahalides such as titanium tetrachloride and titanium tetrabromide with hydrogen, aluminum, titanium, or organometallic compounds of group metals of the periodic table. can be mentioned. In addition, the general formula Ti(OR _{) n}
m<4. ) A trivalent titanium compound obtained by reducing a tetravalent alkoxy titanium halide represented by the following formula with an organometallic compound of a group metal of the periodic table is exemplified. As a vanadium compound,
Tetravalent vanadium compounds such as vanadium tetrachloride, vanadium tetrabromide, and vanadium tetraiodide; pentavalent vanadium compounds such as vanadium oxytrichloride and oxoalkylvanadate; trivalent vanadium compounds such as vanadium trichloride and vanadium triethoxide; Examples include vanadium compounds. Among these titanium compounds and vanadium compounds, tetravalent titanium compounds are particularly preferred. Specific examples of these catalysts include, for example, MgO-RX-TiCl ₄ system (Japanese Patent Publication No. 51-3514),
Mg- _SiCl4 -ROH- _TiCl4 system
), MgCl ₂ −Al(OR) ₃ −TiCl ₄ system (Special Publication No. 51-
152, Special Publication No. 52-15111), MgCl ₂ −SiCl ₄ −
ROH-TiCl ₄ system (JP-A-49-106581), Mg
(OOCR) ₂ −Al(OR) ₃ −TiC ₄ series (Special Publication 1977-
11710), Mg-POCl ₃ -TiCl ₄ system (Special Publication No. 1171-
No. 153), MgCl ₂ −AlOCl−TiCl ₄ system (Special Publication No. 154-
15316) (in the above formula,
An example of a preferable catalyst system is one in which R represents an organic residue and X represents a halogen atom) in combination with an organoaluminium compound. As an example of another catalyst system, a reaction product of an organomagnesium compound such as a so-called Grignard compound and a titanium compound and/or a vanadium compound is used as a solid substance, and an organoaluminum compound is combined with this. Can be done. Examples of organomagnesium compounds include organomagnesium compounds with the general formula RMgX, R ₂ Mg, RMg (OR) (where R is an organic residue having 1 to 20 carbon atoms, and X represents a halogen); Ether complexes and these organomagnesium compounds further modified by adding various other organometallic compounds such as organosodium, organolithium, organopotassium, organoboron, organic calcium, and organozinc can be used. can. Specific examples of these catalyst systems include, for example:
RMgX-TiCl ₄ series (Special Publication No. 50-39470), RMgX
-Phenol-TiCl ₄ system (Special Publication No. 12953/1983),
Examples include combinations of organic aluminum compounds with solid substances such as RMgX-halogenated phenol-TiCl ₄ system (Japanese Patent Publication No. 12954/1983). In these catalyst systems, a titanium compound and/or a vanadium compound can also be used as an adduct with an organic carboxylic acid ester, and after contacting the above-mentioned magnesium-containing inorganic compound solid support with an organic carboxylic acid ester. You can also use Moreover, there is no problem in using an organoaluminum compound as an adduct with an organic carboxylic acid ester. Furthermore, in all cases it is also possible to use catalyst systems prepared in the presence of organic carboxylic esters without any problems. As the organic carboxylic acid ester, various aliphatic, alicyclic, and aromatic acid carboxylic esters are used, and aromatic carboxylic acids having 7 to 12 carbon atoms are preferably used. Specific examples include alkyl esters of benzoic acid, anisic acid, toluic acid, such as methyl and ethyl. Specific examples of organoaluminum compounds to be combined with the above-mentioned solid substances include general formula R ₃ Al;
R ₂ AlX, RAlX ₂ , R ₂ AlOR, RAl(OR)X and
Organoaluminum compound of R _{3 Al 2} Preferred compounds include triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride,
and mixtures thereof. The amount of organoaluminum compound used is not particularly limited, but is usually 0.1 to 0.1 to the amount of transition metal compound.
1000 mole times can be used. In addition, by bringing the above catalyst system into contact with α-olefin and then using it in a gas phase polymerization reaction, the polymerization activity can be greatly improved and the operation can be made more stable than in the case of no treatment. . Various α-olefins can be used as the α-olefin used at this time, but α-olefins having 3 to 12 carbon atoms are preferable, and α-olefins having 3 to 8 carbon atoms are more preferable.
α-olefin is preferred. Examples of these α-olefins include propylene, butene-1, pentene-1, 4-methylpentene-1,
Examples include heptene-1, hexene-1, octene-1, decene-1, dodecene-1, and mixtures thereof. The temperature and time during contact between the catalyst system and the α-olefin can be selected within a wide range, for example from 0 to 200°C, preferably from 0 to 200°C.
Contact treatment can be carried out at 110°C for 1 minute to 24 hours. The amount of α-olefin to be contacted can be selected within a wide range, but it is usually 1 g to 1 g per 1 g of the solid substance.
50,000g, preferably 5g to 30,000g of α-olefin, and 1g to 1g per 1g of the solid material.
It is desirable to react 500 g of alpha-olefin. At this time, the pressure at the time of contact can be arbitrarily selected, but it is usually desirable to contact under a pressure of -1 to 100 kg/cm ³ ·G. During the α-olefin treatment, the entire amount of the organoaluminum compound used may be combined with the solid substance and then brought into contact with the α-olefin, or a part of the organoaluminum compound used may be combined with the solid substance. Afterwards gaseous α-
The polymerization reaction may be carried out by contacting with olefin and adding the remaining organoaluminum compound separately during gas phase polymerization. Further, when the catalyst system and the α-olefin are brought into contact, there is no problem even if hydrogen gas coexists, and there is no problem even if other inert gases such as nitrogen, argon, helium, etc. coexist. The ethylene-α-olefin copolymer of the present invention is produced by copolymerizing gas-phase butethylene and α-olefin in the presence of a solid substance containing magnesium and a titanium compound and/or a vanadium compound and a catalyst consisting of an organoaluminum compound. The polymerization reaction between ethylene and the above α-olefin having 3 to 12 carbon atoms is
The process is carried out in a gas phase substantially free of solvent. As the reactor used, known reactors such as a fluidized bed and a stirring tank can be used. The polymerization reaction temperature is usually 0 to 110°C, preferably
The temperature is 20 to 80°C, and the pressure is normal pressure to 70 kg/cm ³ ·G, preferably 2 to 60 kg/cm ³ ·G. Although the molecular weight can be controlled by adjusting the polymerization temperature, the molar ratio of the catalyst, the amount of comonomer, etc., it is effectively carried out by adding hydrogen to the polymerization system. Of course, a two-stage or more multi-stage polymerization reaction may be carried out using different polymerization conditions such as hydrogen concentration, comonomer concentration, and polymerization temperature. The density of the ethylene-α-olefin copolymer of the present invention is from 0.890 to 0.960 g/cc, preferably from 0.900 to
It is 0.945g/cc. If the density is lower than 0.890 g/cc, the adhesive strength will decrease and the heat resistance will also be poor. Also, the melt index (MI) is 0.1 to 10.0.
g/10 minutes, preferably 0.5 to 7.0 g/10 minutes.
Melt index lower than 0.1g/10min has poor processability, and ESCR is higher than 10.0g/10min.
Both are unfavorable as they result in a decrease in This melt index is measured by the cut-off method according to ASTM-D1238. Examples of unsaturated carboxylic acids or derivatives thereof to be grafted in the present invention include monobasic unsaturated carboxylic acids such as acrylic acid and methacrylic acid, dibasic unsaturated carboxylic acids such as maleic acid and itaconic acid, and their anhydrides. Among these, maleic anhydride is most preferred. As is well known, various methods can be used to react the polyolefin with the unsaturated carboxylic acid or its anhydride. For example, by heating both to a high temperature in the presence or absence of a solvent, with or without the addition of a radical initiator. Other vinyl monomers such as styrene may be present during the reaction. The amount of the unsaturated carboxylic acid or its derivative is preferably 0.01 to 10 parts by weight, more preferably 0.005 to 10 parts by weight, based on 100 parts by weight of the polyolefin whose main component is the ethylene-α-olefin copolymer.
5 parts by weight is preferred. The epoxy resins used in the present invention include ordinary modified and unmodified epoxy resins, epoxy adhesives, and epoxy paints, and if necessary, aliphatic amines, aromatic amines,
A curing agent such as a polyamide resin or an organic carboxylic acid can be used in combination. In the method of the present invention, the epoxy resin may be present in either an uncured or cured state. As the bonding method of the present invention, several well-known methods are possible. In other words, there is a method in which a cured or uncured epoxy resin is interposed on the metal, and a modified polyolefin is powder-coated on the metal by applying an electrostatic coating method, a fluidized dipping method, or a sprinkle coating method, and a modified polyolefin in the form of a film or sheet is applied. Examples include a method of fusing, a method of extrusion coating with a modified polyolefin, a method of coating with a sol-like modified polyolefin, and a method of melt spray coating.
In the present invention, a four-layer structure or a multilayer structure of more than 4 layers may be employed in which an unmodified polyolefin layer is further formed on the outer layer of the modified polyolefin layer. Metals to which the present invention can be applied include, for example, iron, aluminum, tin, zinc, copper, alloys thereof, and metals plated with these metals, and are not particularly limited. Although it is sufficient if the surface of the metal is clean, it is more effective to perform surface treatment such as chemical conversion treatment. If necessary, pigments such as coloring pigments and extender pigments, rust preventive agents, antioxidants, ultraviolet light inhibitors, stabilizers, fillers, antistatic agents, etc. are commonly added to the modified polyolefin or epoxy resin used in the present invention. There is no problem even if it is used in combination with other agents. 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. The preparation of the test piece and the test method were as follows. Preparation of test pieces (1) Metal plate Cold rolled steel plate (SPCC plate, 100mm x 100mm x
2 mm thick) was derusted in advance, degreased with caustic soda, neutralized, dried, and used for testing. (2) Epoxy resin High-build epoxy resin paint (product name: Nitsushin Sunfirst HB, manufactured by Takashi Kubo Paint) (3) Ethylene-α-olefin copolymer Anhydrous magnesium chloride 1 kg, dibutoxydichlorosilane 146 g and tetraiso 267g of propoxytitanium at room temperature under nitrogen atmosphere
The titanium compound was supported on the carrier by ball milling for a period of time. This solid substance is 34 per gram
mg of titanium. A stainless steel autoclave was used as the gas phase polymerization apparatus, and a loop was created with a blower, a flow rate regulator, and a dry cyclone, and the temperature of the autoclave was adjusted by flowing hot water through the jacket. (Polymerization method) The above solid substance was supplied as a catalyst to an autoclave adjusted to 80°C at a rate of 250 mg/hr and triethylaluminum 50 mmol/hr, and the butene-1/ethylene ratio (molar ratio) and hydrogen in the gas phase of the autoclave were The desired ethylene copolymer was obtained by adjusting and circulating the gas in the system using a blower. (4) Modification method 100 parts by weight of the above ethylene copolymer (density 0.92, melt index 8.5), 0.25 parts by weight of maleic anhydride and dicumyl peroxide.
0.005 part by weight was added and melt-kneaded through an extruder to obtain a modified polyethylene copolymer. Test method (1) Adhesive strength A 25 mm wide polyethylene section is pulled at 180° at a tensile speed of 50 mm/min using an Instron type tensile tester, and the adhesive strength is defined as the force required for peeling (Kg/25 mm width). (2) Salt water resistance The time required for scratch marks to be made on a sample and immersion in a 5% saline solution until peeling occurs (HR). (3) ESCR The time required (HR) for a crack to occur when a sample is bent at 180° and immersed in a 10% concentration Reuponox solution at 50°C. Example 1 The high-build epoxy resin paint was applied to the metal plate, dried at 100°C for 60 minutes, and then ethylene-butene-1 copolymer (butene -1 content, 5.8
mol, d = 0.918, MI = 8.5), and further graft-modified ethylene-butene-1 copolymer with 0.25 parts by weight of maleic anhydride per 100 parts by weight of the copolymer was prepared in advance in a 0.5 mm x 50 mm x 100 mm The epoxy resin paint was layered on a baked metal plate and fused using a heat press. The pressing conditions at this time were preheating at 220°C for 5 minutes, heating and pressing at 220°C.
^The material was cooled at 34° C. for 50 kg/cm ² for 5 minutes, and the physical properties are shown in Table 1. Example 2 Example except that an ethylene-butene-1 copolymer modified by adding 0.1 part by weight of maleic anhydride to 100 parts by weight of the ethylene-butene-1 copolymer used in Example 1 was used. The test was carried out in the same manner as in Example 1, and the results are shown in Table 1. Example 3 Ethylene-butene-1 copolymer (butene-1 content:
2.0 mol, d=0.935, MI=8.5) was obtained, Example 1
Modify it using the same method as above, evaluate the physical properties,
The results are shown in Table 1. Comparative Example 1 The results are shown in Table 1 in the same manner as in Example 1 except that the modified ethylene-butene-1 copolymer used in Example 1 was used and no epoxy resin was used. Comparative Example 2 The same procedure as in Example 1 was performed except that high-density polyethylene (Stafrene E870 manufactured by Nippon Petrochemical Co., Ltd.) was used instead of the ethylene-butene-1 copolymer in Example 1, and the results are shown in Table 1. It was shown to. Comparative Example 3 The same procedure as Comparative Example 2 was carried out except that the epoxy resin was not interposed in the metal. The results are shown in Table 1. Comparative Examples 4 and 5 Ethylene-butene-1 obtained by solution polymerization instead of the ethylene-butene-1 copolymer of Example 1
The procedure was carried out in the same manner as in Example 1, except that low-density polyethylene (NeoZex2015M, manufactured by Mitsui Petrochemicals Co., Ltd.) consisting of a copolymer and medium-density polyethylene (manufactured by Mitsui Petrochemicals Co., Ltd.) were used. It is shown in Table 1. Reference Example 1 Table 1 shows the adhesive strength of an ionomer resin (Surlyn A1555, manufactured by Dupont) that has good adhesion to metals without intervening epoxy resin. As is clear from Table 1, the laminate produced by the method of the present invention has remarkable adhesive strength, salt water resistance, and ESCR.

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Claims (1)

[Claims] 1. In a method of bonding a polyolefin and a metal, an epoxy resin is interposed on the metal, and a catalyst consisting of a solid substance containing magnesium, titanium and/or vanadium, and an organoaluminum compound is bonded to the metal. Density 0.890 ~ obtained by copolymerizing ethylene and α-olefin having 3 to 12 carbon atoms in the gas phase in the presence of substantially no solvent.
0.960g/cc, melt index 0.1-10.0
A method of fusing a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof, the main component of which is an ethylene-α-olefin copolymer of g/10 min. 2 The amount of the unsaturated carboxylic acid or its derivative is 0.01 to 10 parts by weight per 100 parts by weight of the polyolefin whose main component is an ethylene-α-olefin copolymer.
The method for adhering metal and polyolefin according to claim 1, wherein the parts by weight are parts by weight.