JPS6254068B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a laminate having excellent interlayer adhesion between a metal layer and a modified polyolefin layer, particularly excellent durable adhesion. Conventionally, metals have been widely coated with synthetic resins for purposes such as corrosion resistance and electrical insulation. For example, polyolefins have strong corrosion resistance against acids, alkalis, and certain organic solvents, and are also used in steel pipes, steel plates, drums, etc. due to their excellent electrical insulation properties and ease of coating work. It is widely used for covering electric wires, machinery and equipment, and for laminated with metal plates. As a method to improve the adhesion between these metal surfaces and the polyolefin layer, polyolefins are modified by, for example, blending unsaturated carboxylic acids or derivatives thereof into the polyolefins, or graft polymerizing these monomers. ing. It is also known to treat metal surfaces with acids or primers. However, although this modified polyolefin or a metal surface coating or a laminate with a metal plate using this modified polyolefin as an adhesive has high adhesion, the adhesive joint has low water resistance and salt water resistance, and water from scratches in the coating layer does not easily escape. There were problems with durability such as infiltration and cathodic electrolysis removability, so-called secondary adhesion. In order to improve these problems, for example, in the method of coating metal pipes with polyethylene via a polyolefin adhesive modified with maleic anhydride, the metal pipes are pretreated with a chromic acid-based or phosphoric acid-based conversion coating. A method has been proposed to apply
- Publication No. 113871). However, although the chromic acid treatment in this method improves secondary adhesion, it uses toxic hexavalent chromium, which poses safety and health problems. On the other hand, although phosphoric acid treatment is simple and has an antirust effect, it cannot be said that the secondary adhesion is necessarily sufficient. The present invention was made for the purpose of improving such drawbacks in conventionally known coatings of metals with resins or laminates of metals and resins.
The present invention is based on the general formula R ¹ _o Si(OR ² ) _4-o [wherein R ¹ is alkyl, vinyl, cycloalkyl, or aryl substituted with a polar group, and R ² is alkyl or aryl which may have a substituent. aryl, n=1 or 2] A metal layer having a polysiloxane film obtained from an organosilane compound represented by This is a laminate coated with a coating layer made of a graft-modified product reacted with the derivative thereof. Examples of metals that can be treated with the organosilane compound in the present invention include aluminum, iron, copper,
These include tin, zinc, nickel, etc., and alloys containing one or more of these, such as stainless steel. Among these, iron and aluminum are preferred. Furthermore, the present invention can be applied to metal molded products in various shapes such as tubes, plates, foils, rods, wires, and others. In the ^present invention, the organic silane compound represented by the general formula R ¹ _o Si(OR ² ) _4-o includes nitrogen, oxygen, Alkyl, vinyl, cycloalkyl or aryl substituted with a polar group containing an element such as sulfuric acid or phosphorus, R ² is alkyl or aryl which may have a substituent, and n
Examples include those with 1 or 2. Among these, those in which R ¹ is substituted alkyl, substituted cycloalkyl or substituted aryl and n=1 are preferred. Examples of the above polar groups include amino,
Examples of the substituent include ureido, glycidoxy, epoxy, merkabuto, methacryloxy, and anilino groups, and examples of the substituents include methoxy groups. Specific examples of R ¹ include γ-aminopropyl, N-β(aminoethyl)-γ-aminopropyl, γ-ureidopropyl, γ-glycidoxypropyl, β-(3,4-epoxycyclohexyl) ) Those having polar functional groups such as ethyl, γ-mercaptopropyl, para-aminophenyl, γ-methacryloxypropyl, γ-anilinopropyl, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyl, and methyl,
Examples include nonpolar ones such as ethyl, propyl, butyl, vinyl, cyclohexyl, phenyl, and octadecyl. Further, specific examples of R ² include methyl, ethyl, propyl, butyl, β-methoxyethyl, and the like. Among these organic silane compounds, those having a polar functional group in R ¹ are preferable, such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β(aminoethyl)-γ-
Preferred examples include aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, and N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane. As a treatment method using an organic silane compound, the above organic silane compound is mixed with water, alcohols such as methanol, ethanol, propanol, and t-butanol, Kents such as acetone, methyl ethyl ketone, and methyl cellosolve, or a mixed solvent thereof with water. 0.05~10% by weight, preferably 0.1~
There is a method of dissolving 2% by weight to make a homogeneous solution and applying this solution to a descaled metal surface at room temperature to 100°C, preferably room temperature to 80°C, or immersing the metal surface in the solution. can give. Application methods include gravure roll, air spray, spray, roll coater, brush, etc., but for continuous treatment, gravure roll, air spray, roll coater, dipping, etc. are preferred. The metal surface coated in this way is heated for 2 hours at a temperature of 60 to 250 °C, preferably 80 to 200 °C, using a heater such as a hot air dryer or an induction heater.
The solvent is removed by heating and drying for 10 seconds to 10 minutes, preferably 10 seconds to 5 minutes, and silanol condensation is simultaneously performed to form a polysiloxane coating. If the concentration of the organosilane compound is less than 0.05% by weight, the effects of the present invention cannot be expected, while if it exceeds 10% by weight, dissolution will be insufficient and both are not preferred.
If the temperature of the solution is outside the above range, if it is too low, the organic silane compound will not be sufficiently dissolved, and if it is too high, the solvent will evaporate rapidly, resulting in poor workability. Further, if the drying temperature is lower than 60°C, the solvent will not be removed sufficiently and the polysiloxane film will not be formed sufficiently, which is not preferable. Next, a method for manufacturing a laminate according to the present invention will be explained using a method for manufacturing a resin-coated metal tube as an example. The base metal steel pipe is cleaned by surface treatment such as shot blasting, grit blasting, or pickling, or by chemical conversion treatment such as zinc phosphate treatment, and then immersed in the above-mentioned solution of the organic silane compound and then taken out. Heat and dry the tube. Then,
The metal tube on which the silane coating has been formed is coated with a polyolefin adhesive by extrusion coating or sheet-like wrapping, and then the exterior resin is further extruded or wrapped in sheet-form to form a laminated coating. . The polyolefin-based adhesive and sheathing material may be extruded and coated in multiple layers on the silane-treated metal tube, or may be laminated and coated by wrapping a composite sheet around the tube. Furthermore, the resin coating of the exterior material may be omitted as appropriate depending on the application. As the polyolefin adhesive, a copolymer obtained by reacting an olefin, a polyolefin, or a hydrocarbon elastomer with an unsaturated carboxylic acid or a derivative thereof, or a grafted modified product can be used. Examples of the olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, and 4-methyl-1-pentene. The polyolefin may be, for example, a homopolymer of the above olefin or one of the above monomers.
Copolymers with 10 mol% or less of other α-olefins or vinyl acetate, etc., with crystallinity of 20% or more (X-ray diffraction method), or mixtures thereof, are included; Density polyethylene, polypropylene, etc. are preferred. Examples of hydrocarbon elastomers include ethylene-propylene rubber, ethylene-1-butene rubber, ethylene-propylene-dienta polymer,
Examples include polyisobutylene rubber, ethylene-butadiene rubber, butadiene rubber, styrene-butadiene rubber, among which ethylene-propylene rubber, ethylene-1-butene rubber,
Polyisobutylene rubber and the like are preferred. As unsaturated carboxylic acids or derivatives thereof,
For example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid, endo-
Bicyclo [2, 2, 1] - 1, 4, 5, 6, 7,
7-hexachloro-5-heptene-2,3-dicarboxylic acid, endo-bicyclo-[2,2,1]-
5-heptene-2,3-dicarboxylic acid, cis-4
Examples include -cyclohexene-1,2 dicarboxylic acid, and acid anhydrides or esters thereof. Among these, maleic anhydride, endo-bicyclo[2,2,1]-5-heptene-
2,3-dicarboxylic anhydride and the like are preferred. Various known methods can be employed for the reaction of the above-mentioned olefin, polyolefin, or hydrocarbon elastomer with the unsaturated carboxylic acid or its derivative. Further, the polyolefin or the hydrocarbon elastomer may be used alone or in combination. Furthermore, the obtained copolymer or graft modified product may be used after being diluted with a polyolefin and/or a hydrocarbon elastomer. The resin for the above-mentioned exterior material is not limited as long as it has an affinity with the above-mentioned polyolefin-based adhesive, and can be selected as appropriate depending on the application. Examples include polyolefin, polyurethane, polyamide, polyester, etc. Among these, polyolefins are preferred, and polyethylene is particularly preferred. As described above, the laminate of the present invention is basically a laminate in which a metal layer having a polysiloxane film made of an organic silane compound on the surface and a modified polyolefin layer are laminated to form a metal layer/polysiloxane film/modified polyolefin layer. It is not limited to coating the outer surface of metal tubes, but also resin coating of the inner surface of tubes, plates, foils, rods, wires, and other metal surfaces of various shapes, laminates of metal and resin, and coatings on metal. It can also be applied to printing, etc. In addition, by applying the organic silane compound treatment of the present invention, it is possible to prevent rusting during the process from descaling the metal surface to the resin coating process, and to improve the adhesive strength and bondability of metal and coating resin and metal and resin laminates. Next, adhesion can be enhanced. EXAMPLES Hereinafter, the laminate of the present invention will be explained in more detail using Examples. In addition, % in the examples indicates weight,
The test method is as follows. (1) Melt index (MI) JISK6760 (2) Melt flow index (MFI)
JISK6758 (3) Adhesive strength For coated metal tubes, cut the resin layer into 1cm wide strips, peel off the adhesive layer from one end, and cut the resin layer into 5cm/width strips.
A 90° peel test was performed at a speed of 1 minute. In addition, in the case of a laminate, cut the laminate into a 25 mm x 300 mm strip, peel off the end face by 50 mm to use as a gripping margin, perform a 90° peel test at a speed of 10 cm/min, and evaluate the adhesive strength at 2.5. The adhesive strength per 1 cm width was calculated. (4) Soaking in saline solution In the case of coated metal pipes, the tubes were immersed in a 3% NaCl solution at 80°C, and the degree of peeling of the coating was examined after 100 hours. In addition, in the case of laminated board, 50mm x 200mm
The test piece was immersed in a 3% NaCl solution at 60°C, and the degree of penetration was examined from the end face after 30 days. (3) Cathodic electrolytic stripping property ASTM G-8-72 compliant, 5mmφ Holiday, applied voltage 1.5V, 20℃/30 days, in 3% NaCl solution. (4) Rust prevention The pickled products and those treated with organic silane were observed for rust after 5 days. No rust was rated as ○, and rust was rated as ×. (5) Heat cycle test A 52 m x 300 mm laminate was used as a test piece, and the test piece was placed in a constant temperature bath at -30°C for 8 hours, and then in a constant temperature bath at 60°C for 16 hours, making this one cycle. The adhesive strength of the test piece was measured after the same cycle was repeated 10 times. (6) Post-workability (bending) A 25 mm x 200 mm laminate was used as a test piece, and this test piece was wound around the circumference of a 6 mmφ steel bar and bent to a radius of 3 mmφ. The bent portion was cut and the state of peeling was observed. Examples 1 to 3 A 50mmφ SGP black tube as a test metal tube was descaled by a pickling method, and then immersed in an aqueous solution of γ-aminopropyltriethoxysilane at each concentration shown in Table 1 at a temperature of 80℃. The adhesive material (a modified mixture of linear low-density polyethylene and polyisobutylene rubber grafted with 0.6% maleic anhydride) was then applied to the metal tube dried at 120°C.
Extrusion coated with 0.4mm and then high density polyethylene (density = 0.935g/cc, MI = 0.2g/10min)
was laminated and coated with a thickness of 3 mm. The resulting resin-coated metal tube was tested for adhesive strength, saline immersion, and cathodic electrolysis peelability, and the results are shown in Table 1. In addition, regarding rust prevention properties, comparisons were made between those after pickling and those after silane treatment. Examples 4 to 6 In Example 1, N-β (aminoethyl)-γ was used instead of γ-aminopropyltriethoxysilane.
Coating was performed in the same manner except that -aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane and γ-anilinopropyltrimethoxysilane were used, and the results are also listed in Table 1. Comparative Examples 1 and 2 In Examples, resin coatings were performed in the same manner as those without pretreatment with an organic silane compound and those treated with zinc phosphate instead of the organic silane compound, and the results are also listed in Table 1. .

【table】

[Table] Example 7 Using the continuous laminate manufacturing equipment shown in Figure 1, a cold rolled steel plate (thickness 0.2 mm, width 300 mm) 1, an aqueous solution of γ-aminopropyltriethoxysilane with a concentration of 1% was applied to the surface of each layer using a roll coater 6 at a take-up speed of 5 m/min, and the outlet temperature was 100
Each was dried in a steel sheet preheating dryer 9 at ℃. Next, modified polyethylene (linear low-density polyethylene (MI = 2.0 g/10
minute, density = 0.926g/cc, hereinafter L-LDPE-1) 80
and ethylene-1-butene rubber (MI=4.0g/10
Modified product in which 0.6% maleic anhydride is grafted onto a mixture of 20 parts of min., density = 0.88 g/cc, hereinafter EBR)
A composition consisting of 25 parts of L-LDPE-1, 60 parts of L-LDPE-1, and 15 parts of EBR] was passed through a 65 mmφ extruder 11.
The laminated plate 16 was manufactured by extruding at an extrusion temperature of 230° C. and heat-pressing with rolls at a set temperature of 180° C. and a set pressure of 1.0 Kg/cm ² . The thickness composition of the obtained laminate is as follows:
Steel plate/modified polyethylene/steel plate is 0.2mm/0.4mm/
It was 0.2mm. The obtained laminate was tested for adhesive strength, saline immersion, heat cycle test, and post-processability (bending), and the results are shown in Table 2. Examples 8 to 14 In Example 7, Table 2 was used instead of the aqueous solution of γ-aminopropyltriethoxysilane with a concentration of 1%.
A laminate was produced in the same manner except that a solution of an organic silane compound as shown in Figure 1 was used, and the test results are also listed in Table 2. Comparative Examples 3 to 5 In Example 7, the pretreatment with an organic silane compound was not performed, and instead of the organic silane compound treatment, zinc phosphate treatment and chromate treatment were performed in advance in a conventional manner, and the steel plate was preheated. A laminate was manufactured in the same manner except that the dryer outlet temperature was 130°C and the steel plate preheating temperature was 120°C, and the test results are also listed in Table 2.

【table】

[Table] Example 15 In Example 7, modified polypropylene [crystalline propylene-ethylene block copolymer [MFI = 1.0 g/10 min, ethylene content = 7.0%, hereinafter referred to as PP block-1] was used instead of modified polyethylene. 85
and ethylene-propylene rubber (MI=4.0g/10
20 parts of a modified product obtained by grafting 0.5% maleic anhydride to a mixture of 15 parts of ethylene content = 72% (hereinafter EPR), 68 parts of PP Block-1, and
Using a composition consisting of 12 parts of EPR], the outlet temperature of the steel plate preheating dryer was set to 150℃, and the steel plate preheating temperature was set to 150℃.
A laminate was produced in the same manner except that the temperature was 140°C.
The test results are shown in Table 3. Example 16 In Example 15, a crystalline propylene-ethylene block copolymer (MFI = 1.0 g/10 min, ethylene content = 7.0) was used instead of modified polypropylene.
%, hereinafter referred to as PP block-2) with 0.6% of endobicyclo[2,2,1]-5-heptene-2,3-dicarboxylic anhydride grafted 20
A laminate was produced in the same manner as above except that the temperature at the outlet of the preheating dryer for the steel plate was 160°C and the preheating temperature for the steel plate was 150°C using a composition consisting of 80 parts of PP block 2 and 80 parts of PP block 2. The results are also listed in Table 3. Example 17 In Example 7, instead of modified polyethylene,
Modified nylon [linear low density polyethylene (MI=
5.0g/10 minutes, density = 0.934g/cc or less L-LDPE-
2) 40 parts of a modified product obtained by grafting 0.6% maleic anhydride to a mixture of 50 parts of polyisobutylene (manufactured by Etsuo Chemical: Vistanecs MML-80 (trade name)) and crystalline 6 nylon (manufactured by Unitika: A ―
A laminate was produced in the same manner except that the temperature at the outlet of the preheating dryer for the steel plate was 180°C and the preheating temperature for the steel plate was 170°C. The results are also listed in Table 3. Comparative Examples 6 to 8 In Examples 15, 16, and 17, no pretreatment with the organosilane compound was performed, and the preheating drying temperature of the steel plate and the preheating temperature of the steel plate were 180°C and 170°C, respectively.
(Comparative Examples 6 and 7) and 200°C and 190°C (Comparative Example 8) produced laminates in the same manner,
The test results are also listed in Table 3. Example 18 In Example 7, pure aluminum-based 1100-H24 material (thickness 0.2 mm, width 300
A laminate was produced in the same manner except that mm) was used,
The test results are also listed in Table 3.

【table】 [Brief explanation of the drawing]

FIG. 1 is a schematic side view of a continuous laminate manufacturing apparatus showing an embodiment of the present invention. 1...Metal sheet, 2...Modified polyolefin, 3...Uncoiler, 4...Take-up roll, 5
...Guide roll, 6...Surface coating device, 7...
... Doctor knife, 8 ... Surface coating liquid and container, 9 ... Preheating drying device, 10 ... Guide roll, 11 ... Extruder, 12 ... T-die, 13 ...
...Heating pressure bonding roll, 14... Preheating device, 15...
Cooling device, 16...Laminated board.

Claims (1)

[Claims] 1 General formula R ¹ _o Si(OR ² ) _4-o [However, R ¹ is alkyl, vinyl, cycloalkyl, or aryl substituted with a polar group, and R ² is a metal layer having a polysiloxane film obtained from an organic silane compound having a good alkyl or aryl, and n=1 or 2], and a polyolefin and/or hydrocarbon elastomer and an unsaturated carbon dioxide on the surface of the polysiloxane film. A laminate coated with a coating layer made of a graft-modified product reacted with an acid or its derivative.