JPS6160767B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a laminate of metal and polyolefin. Due to its inherent properties, polyolefin has been widely used for lining steel pipes, drums, etc., coating electric wires, machinery and equipment, and protecting glass. Particularly, metal surfaces such as iron and aluminum are frequently coated, and various processing methods have been proposed. However, polyolefins such as polyethylene, polypropylene, and polybutene do not have polar parts, such as functional groups, in their molecules and are highly crystalline, so they have extremely poor adhesion to iron, aluminum, etc. This was the biggest difficulty in doing so. Various attempts have been made to improve this adhesiveness. For example, methods have been proposed to treat the adhesive surface of polyolefin with solvent treatment, flame treatment, heated air treatment, oxidation treatment, etc., or methods to mechanically roughen or surface oxidize the metal surface to be bonded. ing. However, all of these methods not only require complicated processing operations, but also fail to provide sufficient adhesive strength. Furthermore, even if sufficient adhesive strength is obtained, if it comes into contact with an aqueous solution containing electrolytes such as seawater or saline, the adhesive strength will decrease and rust will occur within a short period of time, resulting in peeling from the adhesive surface or Since a phenomenon in which the resistance to impact decreased was observed, it was unsuitable for applications requiring salt water resistance. As a solution to these problems,
No. 6012 proposes that a polyolefin composition with excellent adhesiveness can be obtained by modification with a hydrocarbon polymer having one or more active hydrogens at its ends. Although this invention has excellent adhesion between polyolefin and specific dissimilar materials such as aluminum, it has sufficient adhesion with epoxy primer-coated steel sheets used in fields where water resistance and salt water resistance are particularly required. It wasn't. The inventors of the present invention have conducted various studies to solve these problems, and as a result, they have found that they not only have sufficient adhesive strength with epoxy primer-coated steel sheets, but also have excellent water resistance, especially salt water resistance, and polyolefin. The present invention was achieved by discovering a method for manufacturing a laminate. That is, the gist of the present invention is to provide a polymer obtained by reacting a hydrocarbon polymer having active hydrogen with an unsaturated polycarboxylic acid or its derivative and a monoepoxy compound or its derivative, and then reacting it with an aromatic polycarboxylic acid or its derivative. A metal characterized in that a thermoplastic or thermosetting epoxy resin adhesive is interposed between a polyolefin composition prepared by blending the above into a polyolefin and the metal to fuse the composition to the metal. and a method for producing a polyolefin laminate. The present invention will be explained in more detail below. The polyolefin composition of the present invention is made by blending a special polymer and a polyolefin, which will be described later. Examples of the base polyolefin include high-density polyethylene, low-density polyethylene, medium-density polyethylene, ethylene-propylene copolymer, and ethylene-butene copolymer. -1 copolymer, polypropylene,
Propylene-butene-1 copolymer, polybutene-
1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene-dicyclopentadiene terpolymer, and the like. Among these various polyolefins, high-density polyethylene, medium-density polyethylene, and low-density polyethylene are usually used. Next, the hydrocarbon polymer having active hydrogen, which is the raw material for the special polymer in which the above-mentioned polyolefin is blended, has functional groups such as hydroxyl group, carboxyl group, imino group, mercapto group, and amino group at the end. , the number of active hydrogens in the functional group is on average 1 or more per molecule, preferably 1.2 to 3.0, and the main chain is a conjugated diene polymer or a copolymer of a conjugated diene and a vinyl monomer, or a hydrogenated product thereof. and the molecular weight is the weight average molecular weight,
500 to 50,000. The main chain hydrocarbon polymer is preferably saturated from the viewpoint of adhesiveness. Therefore, for example, if the main chain is a conjugated diene polymer or a copolymer of a conjugated diene and a vinyl monomer, and the double bonds are mainly in the main chain, 30% or more of the double bonds in the main chain are It is preferable to add it to a saturated or partially saturated state. However, as described in Japanese Patent Publication No. 53-6012, hydrocarbon polymers having active hydrogen can be produced by various well-known methods such as radical polymerization using conjugated dienes or conjugated dienes and vinyl monomers as raw materials. It can be produced by legal, anionic polymerization. In the case of radical polymerization, the type of functional group containing active hydrogen varies depending on the polymerization conditions. For example, when hydrogen peroxide or azobiscyano acid is used as a polymerization initiator, a polymer having a hydroxyl group or a carboxyl group at the terminal, respectively, is obtained. It will be done. In the case of the anionic polymerization method, by reacting a living polymer with monoepoxide or carbon dioxide gas, a polymer having a hydroxyl group or a carboxyl group at the end, respectively, can be obtained. Here, the living polymer is a polymer produced by polymerizing a conjugated diene alone or a conjugated diene and a vinyl monomer using an anionic polymerization catalyst, such as an alkali metal, according to a well-known method, and whose both terminals are A substance having a structure in which an alkali metal is bonded to at least one of the above. Examples of the conjugated diene include butadiene 1,3 and isoprene, and examples of the vinyl monomer include styrene, methyl acrylate, and acrylonitrile. The amount of vinyl monomer used is preferably 50% by weight or less based on the total amount of monomers. As mentioned above, it is preferable that the double bonds in the main chain of these conjugated diene polymers or copolymers are hydrogenated in whole or in part before use. but,
In the case of polybutadiene with 1,2 bonds and no double bonds in the main chain, it is used as is. The method of hydrogenation may be a well-known method, and a nickel catalyst, a ruthenium catalyst, a platinum catalyst, etc. may be used. Another method for producing a hydrocarbon polymer having active hydrogen includes a method in which a copolymer of α-olefin and other monomers is oxidized and decomposed, and then reduced. On the other hand, examples of unsaturated polycarboxylic acids or derivatives thereof to be reacted with the hydrocarbon polymer having active hydrogen include maleic acid, fumaric acid, itaconic acid, citraconic acid, and their anhydrides, acid halides, and alkyl esters. Examples of the monoepoxy compound include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, phenyl glycidyl ether, glycidyl acrylate, and the like. Derivatives include glycols, which are hydration products of monoepoxy compounds. The amount of the unsaturated polycarboxylic acid or its derivative and the monoepoxy compound or its derivative to be reacted with the hydrocarbon polymer having active hydrogen is not particularly limited, and depends on the type of functional group having active hydrogen in the raw material polymer and the amount obtained. It is selected as appropriate depending on the physical properties required of the polymer, the type of functional group, etc. For example, when using a raw material polymer with a hydroxyl group at the end and desiring the resulting polymer to have a carboxyl group at the end, use an excess of unsaturated polycarboxylic acid or its derivative relative to the monoepoxy compound or its derivative. Just use it. As described in Japanese Patent Publication No. 53-6012, the reaction is carried out by adding an unsaturated polycarboxylic acid or its derivative and a monoepoxy compound or its derivative to a hydrocarbon polymer having active hydrogen in the presence of a catalyst. It may be heated under or in the absence. As the catalyst, tertiary amines, quaternary ammonium compounds, alkali metal salts, and other common esterification catalysts and ring-opening polymerization catalysts are used. The reaction temperature is preferably 80°C to 100°C. Another reaction method involves reacting an unsaturated polycarboxylic acid or its derivative with a monoepoxy compound or its derivative in advance to produce a low molecular weight polyester with terminal carboxyl groups, which is then dehydrated with a hydrocarbon polymer having active hydrogen. Examples include a method of carrying out an esterification reaction under the following conditions, or a method of sequentially reacting a hydrocarbon polymer having active hydrogen with an unsaturated polycarboxylic acid or its derivative and a monoepoxy compound or its derivative in this order or in the reverse order. It will be done. The polymer obtained by this reaction is one in which active hydrogen contained in a hydrocarbon polymer reacts with an unsaturated polycarboxylic acid or its derivative and a monoepoxy compound or its derivative to form one or more polyester blocks. It is. For example, when a hydrogenated polyhydroxypolybutadiene having a hydroxyl group at the end is reacted with maleic anhydride and epichlorohydrin in a ratio of 1:n:n in terms of hydroxyl group equivalents, a polyester block as shown in the following formula is formed at the end of the main chain. A polymer is obtained. If the amount (molar amount) of maleic anhydride is larger than that of epichlorohydrin, the maleic anhydride will further react to form a carboxy group at the end. (The formula represents a polyhydroxy saturated hydrocarbon polymer residue, n represents an integer of 1 or more, and increases as the amount of maleic anhydride and epichlorohydrin increases.) Therefore, the polymer represented by the above formula In the derivative, the ratio of the polyester unit part to the part is 100 parts by weight of the former and 5 to 100 parts by weight of the latter.
Parts by weight ranges are preferred. The polymer obtained by the reaction as described above (hereinafter referred to as component A) is then reacted with an aromatic polycarboxylic acid or a derivative thereof. Examples of aromatic polycarboxylic acids or derivatives thereof include aromatic dicarboxylic acids, tricarboxylic acids,
Examples include tetracarboxylic acids, their anhydrides, acid halides, and those derived from these with functional groups such as hydroxyl groups and epoxy groups. Specifically, examples include phthalic acid, trimellitic acid, pyrimellitic acid, and these. anhydride, hemimellitic anhydride, naphthalene-1,2,5-tricarboxylic acid, naphthalene-1,2,5-tricarboxylic acid-1,2 anhydride, naphthalene-1,3,8-
Tricarboxylic acid, naphthalene-1,3,8-tricarboxylic acid-1,8 anhydride, naphthalene-1,
Examples include 4,5-tricarboxylic acid-4,5 anhydride, trimellitic anhydride acid chloride, hemimellitic anhydride acid chloride, 4-hydroxylphthalic anhydride, and the like. Among these, trimellitic anhydride acid chloride and pyromellitic anhydride are preferred. The reaction between component A and aromatic polycarboxylic acid or its derivative (hereinafter referred to as component B) is as follows:
It is carried out by heating in the presence or absence of a catalyst. As a catalyst, an organic tin compound,
Tertiary amines, quaternary ammonium compounds, alkali metal salts, and other conventional esterification catalysts are used. Further, the reaction temperature is not particularly limited, but is preferably 50°C or higher. However, if the temperature is too high, side reactions such as gelation occur, which is undesirable, and if the temperature is too low, the reaction rate decreases, which is undesirable. Therefore, a temperature of 80°C to 150°C is preferred.
The usage ratio of both components is 0.1 to 10 mol, preferably 0.2 to 8 mol, of component B per 1 mol of active hydrogen of component A. The product obtained by the reaction as described above has a group consisting of an aromatic polycarboxylic acid or a derivative thereof. For example, depending on the product, pyromellitic anhydride or 4-hydroxyphthalic anhydride is reacted with a polymer obtained by reacting the aforementioned hydrogenated polyhydroxypolybutadiene with hydroxyl groups at the terminals with maleic anhydride and epichlorohydrin. By doing so, a polymer having an acid anhydride at the terminal as shown in the following formula is obtained. or The composition of the present invention is obtained by blending the above-obtained polymer having a group consisting of an aromatic polycarboxylic acid or a derivative thereof (hereinafter referred to as a polymer derivative) with the polyolefin. As for the blending method, for example, the two may be mixed using a Henschel mixer, a V-shaped blender, etc., and then pelletized using an extruder, double screw mixer, etc., or the two may be blended by charging both into a Banbury mixer or twin-screw roll mixer. Examples include a method of cutting it into pellets using a sheet cutter. The temperature in these methods varies depending on the type of polyolefin used; for example, in the case of high-density polyethylene, it is melt-kneaded at 115°C to 250°C. The mixing ratio is selected at a ratio that effectively exhibits the properties of the composition of the present invention, which will be described later, but is usually in the range of 0.05 to 100 parts by weight, preferably 0.1 to 10 parts by weight, of the above polymer derivative per 100 parts by weight of the polyolefin. selected from. Another blending method includes a method in which polyolefin is present when producing a polymer derivative by reacting component A and component B. That is, 0.05 parts by weight of component A to 100 parts by weight of polyolefin.
100 parts by weight, preferably 0.1 parts by weight to 10 parts by weight, and 0.01 parts by weight to 10 parts by weight of component B are blended and melt-kneaded. In this case, due to the presence of polyolefin,
No gelation occurs even if kneaded at a temperature of 200°C or higher. Therefore, the melt-kneading temperature may be 115°C to 250°C. Further, during melt-kneading, the above-mentioned esterification catalyst and ring-opening polymerization catalyst used for the reaction of component A and component B may be added. The melt-kneading method may be the same as the above-mentioned method. According to this method,
Since the production of the polymer derivative and the blending with the polyolefin are carried out simultaneously, it is advantageous in terms of the process and physical properties such as less thermal decomposition of the polyolefin. It goes without saying that the polyolefin composition described above may further contain colorants, stabilizers, other additives, and fillers that are conventionally commonly used. Fillers include natural silica such as sand quartz, synthetic silica produced by wet or dry methods, natural silicates such as kaolin, mica, talc, clay, and asbestos, synthetic silicates such as calcium silicate, aluminum silicate, and alumina. , metal oxides such as titania, calcium carbonate, calcium sulfate, other metal powders such as aluminum and bronze, carbon black, etc. can be used. In the present invention, when such a polyolefin composition is fused to metal, it is necessary to use an epoxy resin adhesive. As such an adhesive, various known adhesives used for fusing polyolefins or polyolefin compositions having various functional groups to metals can be used. For example, various epoxy resin adhesives described in US Pat. No. 4,048,355 can be used. One of them is the molecular weight that is not included in the curing agent.
More than 10,000 thermoplastic epoxy resins are used. In this case, it is not preferable to use a material with a low molecular weight because the adhesive strength will be low. In the present invention, it is also possible to use epoxy resins having a molecular weight of about 500 to 10,000 and containing so-called epoxy resin curing agents such as amines, polyamides, acid anhydrides, phenolic resins, and butylated urea formaldehyde resins. The epoxy resin used for this is generally a bisphenol A-based epoxy resin, but other types may also be used. Furthermore, the present invention includes adhesives having a molecular weight of 800 to 800.
30 to 70 parts by weight of 4000 epoxy resin and carbon number
So-called epoxy esters, which are reaction products of 70 to 30 parts by weight of 10 to 20 fatty acids, or
It is also possible to add and use a curing agent such as butylated melamine formaldehyde resin within 30% by weight. A film thickness of about 5 to 100 microns is sufficient for the epoxy resin adhesive, and the general method is to dissolve it in a suitable solvent and apply it to the metal surface using, for example, spraying or a bar coater. The polyolefin composition is fused onto the adhesive. Examples of metals used for adhesion with the polyolefin composition include iron, aluminum, tin, zinc, alloys thereof, and metals plated with these metals. It is sufficient if the metal surface is clean, but blasting or chemical conversion treatment is more effective. Several known methods can be used to fuse the polyolefin composition. Specifically, there are methods of powder coating a polyolefin composition on metal by applying an electrostatic coating method, fluidized dipping method, or sprinkle coating method, a method of fusing a polyolefin composition in the form of a film or sheet, and a method of extrusion coating of a polyolefin composition. A method of coating a polyolefin composition in the form of a sol, etc. In addition, an ordinary polyolefin layer can also be formed in the same manner as the outer layer of the coating layer of the special polyolefin composition of the present invention. For this fusion, if a thermoplastic type epoxy resin adhesive is used, it is necessary to heat the adhesive to a temperature of 200° C. or higher. In addition, when a thermosetting adhesive is used, the epoxy resin adhesive is coated with a polyolefin composition and fused while it is uncured or in the process of curing, that is, while it still has thermosetting properties. It is necessary to do so. Even if the polyolefin composition is fused after the epoxy resin adhesive has completely cured, good adhesion cannot be obtained. However, when a thermosetting epoxy resin adhesive is used to fuse the adhesive while it is in the process of curing, the cured state is, for example, 30% in terms of gelation rate.
~90%. The polyolefin composition is fused under conditions such that the epoxy resin adhesive is completely cured. Good adhesion cannot be obtained unless curing is completed. Note that the gelation rate refers to a thermosetting epoxy resin adhesive that is heated appropriately to gel, and then mixed with methyl ethyl ketone and ethylene glycol monomethyl ether in a ratio of 1:1.
(Volume) This is the percentage of the material that remains undissolved when immersed in a mixed solvent and held at 25°C for 5 minutes.
Assuming that the weight before immersion is A and the remaining weight after immersion is B, it is defined by the following formula. Gelation rate = B / A × 100 (%) As detailed above, according to the present invention, metal and polyolefin can be firmly bonded,
In addition, a laminate with excellent salt water resistance can be obtained. There is a method of using maleic anhydride-modified polyolefin to improve the adhesion between metals and polyolefins, but the method of the present invention provides excellent adhesion in areas where the content of polycarboxylic acid or its derivatives is smaller than that method. It has the advantage of providing strength and excellent salt water resistance. Next, examples of the present invention and production examples (reference examples) of a special polymer C constituting the polyolefin composition used in the present invention will be explained. It is not subject to any restrictions. Reference Example 1 (Production of saturated hydrocarbon polymer having active hydrogen) Polyhydroxypolybutadiene (R-45HT manufactured by Arco Chem.,
Mn3110, [-OH] = 0.82meq/g, cis1,4:15
%, trans-1,4: 58%, vinyl: 27%) 3
Kg, cyclohexane 3Kg and carbon-supported ruthenium (5%) catalyst [manufactured by Nippon Engelhard Co., Ltd.]
After charging 300g and replacing the inside of the system with purified argon gas, high-purity hydrogen gas is started to be supplied into the autoclave, and heating is started at the same time. It took about 30 minutes for the inside of the autoclave to reach steady conditions (internal temperature 100°C, internal pressure 150 Kg/cm ² ). After 15 hours under these conditions, the hydrogenation reaction was stopped, and the polymer was purified and dried according to a conventional method. As a result of analysis by infrared absorption spectrum, the obtained polymer was found to be a hydrocarbon polymer containing almost no double bonds. -OH group of hydrogenated product is 0.81meq/g
It was hot. 14.9 parts by weight of maleic anhydride, 0.18 parts by weight of N,N-dimethylbenzylamine, and 100 parts by weight of toluene were added to 100 parts by weight of the saturated hydrocarbon polymer having hydroxyl groups at the terminals prepared by the above method. After reacting maleic anhydride, 7.0 parts by weight of epichlorohydrin was added and reacted. The reaction temperature was 110°C for 4 hours. After that, 35.2 parts by weight of epichlorohydrin was added,
After reacting at 110°C for 3 hours, toluene was removed to obtain a product. Hereinafter, this product will be referred to as component A. Example 1 For 100 parts by weight of component A obtained in Reference Example 1, 17.7 parts by weight of pyromellitic anhydride, 0.1 parts by weight of dibutyltin oxide, 50 parts by weight of toluene, N,
After adding 50 parts by weight of N' dimethylformamide and carrying out the reaction at a reaction temperature of 110 DEG C. for 2 hours, the mixture was precipitated in acetone and dried to produce a special polymer derivative that provides adhesive properties to polyolefins. 1.0 parts by weight of the above polymer derivative was mixed into 100 parts by weight of high-density polyethylene (Novatek BR002, Novatek is a registered trademark of Mitsubishi Chemical Industries, Ltd.).
Knead for 3 minutes using a Banbury (resin temperature 200
~220°C) An adhesive polyolefin composition was obtained.
On the other hand, epoxy resin manufactured by Ciel Chemical Co., Ltd. (Epicoat)
1:1 mixture of 1001 and Epicote 828, bisphenol A epoxy resin, Epicote is a trademark)
Polyamide curing agent (Tomide 235A, Tomide is a trademark of Fuji Kasei Kogyo Co., Ltd.) per 100 parts by weight
Dissolve 50 parts by weight in a mixed solution of methyl isobutyl ketone, cellosolve, and n-butanol (solid content 10%).
weight) and was applied onto the surface of a blast-treated steel plate (1.6 mm thick) using a bar coater (#8).
The steel plate was heated at 160°C for 5 minutes on a hot plate to harden the epoxy resin adhesive on the surface of the steel plate to a gel content of 60%, and then the polyolefin composition was placed on the steel plate and heated at 240°C using a hot press. Pressed for 15 minutes. To specify the thickness of the laminate during pressing
A 5.2mm spacer was used. The pressed pieces were taken out and cooled for 20 minutes in a cooling press (temperature set at 18°C) to obtain a laminate. The thickness of the polyethylene layer of the obtained laminate was about 3 mm. A sample with a length of 100 mm and a width of 25 mm was cut from this laminate and subjected to a 180° peel test (using Tensilon, peeling speed was 50 mm/mi).
n) was carried out. Peel strength at this time (Kg/cm)
are shown in Table-1. In addition, from the same laminate, we also have a length of 90 mm and a width of 20 mm.
A sample was cut out and immersed in 3% saline solution at 60°C for 60 hours to conduct a salt water resistance test.
The results are shown in Table-1. The evaluation of this salt water resistance test was to look at the state of peeling in the width direction of 20 mm, and the maximum value of the peeling distance from both end faces was read. Example 2 Epicoat 1007 as an epoxy resin adhesive
(manufactured by Ciel Chemical Co., Ltd., Epicoat is a trademark), and 50 parts by weight of a butylated urea curing agent Melan 11 (Melan is a trademark of Hitachi Chemical Co., Ltd.) are mixed with methyl isobutyl ketone and cellosolve. A laminate was obtained in the same manner as in Example 1 except that the solid content was 10% by weight. A sample was cut out from this laminate in the same manner as in Example 1, and a peel test and a salt water resistance test were conducted. The results are shown in Table-1. Example 3 To 100 parts by weight of high-density polyethylene (Novatec BR002, Novatec is a registered trademark of Mitsubishi Chemical Industries, Ltd.), 1.0 parts by weight of component A obtained in Reference Example 1, 0.08 parts by weight of pyromellitic anhydride, and dibutyl 0.01 part by weight of tin oxide was uniformly dispersed and blended, and kneaded using a Midget Banbury to obtain a polyolefin composition. A laminate was obtained using this polyolefin composition in the same manner as in Example 1, and a peel test and a salt water resistance test were conducted. The results are shown in Table-1. Comparative Example 1 A laminate was produced in the same manner as in Example 1, except that component A obtained in Reference Example 1 was used as it was without being modified with pyromellitic anhydride, and the peel strength,
Table 1 shows the measurement results of the salt water resistance test. Comparative Example 2 A laminate was produced in the same manner as in Example 3, except that pyromellitic anhydride was not used, and the peel strength,
Table 1 shows the measurement results of the salt water resistance test. 【table】

Claims (1)

[Claims] 1. A hydrocarbon polymer having active hydrogen at the molecular end is reacted with an unsaturated polycarboxylic acid or its derivative and a monoepoxy compound or its derivative, and then an aromatic polycarboxylic acid or its derivative is reacted. A thermoplastic or thermosetting epoxy resin adhesive is interposed between the metal and the olefin composition obtained by blending the obtained polymer with polyolefin, and the composition is fused to the metal. A method for producing a laminate of metal and polyolefin. 2. The method for producing a metal and polyolefin laminate according to claim 1, which comprises interposing an epoxy resin adhesive that is uncured or in the process of curing.