JPS5920447B2 - Metal/olefin polymer laminate and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminate of a metal body and an olefin polymer that exhibits a high degree of salt water resistance, and a method for producing the same.

Conventionally, when non-polar resins such as polyolefins are used to coat metal surfaces with resin to prevent metal surface corrosion, various treatments are applied to the resin surfaces, or olefins are used as the resin. Countermeasures have been proposed, such as using a copolymer with a polar comonomer or a modified polyolefin obtained by grafting a polar monomer onto a polyolefin molecule.

However, when steel pipes are used under severe conditions such as transporting salt water, conventional measures have little effect.
Therefore, it was necessary to apply a primer that has high affinity to both the steel and the coating resin to the surface of the steel pipe, and to laminate a modified polyolefin coating thereon. The present inventor has developed a useful treatment method for applying a resin coating directly to a metal surface without applying a complicated primer as described above, and as a result, a metal/olefin polymer that exhibits a high degree of salt water removability has been developed. We succeeded in producing a laminate.

In the present invention, the invention described in claim 1 is characterized by ``a salt-resistant product comprising a metal body and an olefin polymer whose surface has been subjected to contact treatment with a vapor phase of a substance selected from acids and derivatives thereof. The invention relates to a "water-releasable laminate," and the invention according to claim 2 is directed to "bringing the surface of a metal body into contact with a vapor phase of a substance selected from acids and derivatives thereof, and then contacting the surface with a vapor phase of a substance selected from acids and derivatives thereof. The present invention relates to a method for producing a salt water-releasable laminate characterized by laminating olefin polymers.

The laminate of the present invention is produced by laminating an olefin polymer on the treated surface of a metal body using known means.

Of course, the olefin polymer layer can be applied to one or both sides of the metal body. The metal material that can be used to manufacture the laminate of the present invention is a metal that hardly reacts with water at around room temperature or that does not substantially generate hydrogen even if it reacts. For example, iron
Aluminum, zinc, tin, copper, those plated on a substrate, and alloys thereof can be mentioned, but particularly preferred metals in the present invention are iron and alloys thereof, such as steel. It is preferable that the surfaces of these metals be clean before coming into contact with a vapor phase such as an acid, and it is desirable to remove rust, dirt, etc., and to further degrease the surfaces.
The surface may be roughened if necessary. Acids and the like used for surface treatment of metal objects include those that generate vapor near the treatment temperature, such as those that vaporize in the form of evaporation, sublimation, etc. and reduce the molecular concentration of the acid, etc. in the treatment atmosphere to 10-
Organic acids, inorganic acids, their anhydrides, halogenides, as long as they reach 5 m01/l or more and can treat metal surfaces.
Any acid derivatives (sometimes referred to as acids etc. in the present invention) such as partial esters and partial esters may be used. Examples of inorganic acids and derivatives thereof include the following.

Hydrogen chloride, hydrogen bromide, hydrogen iodide, hydrochloric acid, hydrobromic acid,
Hydrohalic acids such as hydroiodic acid, sulfur oxygen acids such as sulfuric acid, pyrosulfuric acid, sulfurous acid, sulfur oxides such as sulfur trioxide and sulfur dioxide, sulfur oxygen acids such as thionyl chloride, sulfuryl chloride, and chlorosulfonic acid. Acid halides, nitrogen oxygen acids such as nitric acid and nitrous acid, nitrogen oxides such as nitrogen pentoxide, nitrogen tetroxide, nitrogen dioxide, nitrogen monoxide, and nitrous oxide, ditrosyl chloride, ditrosyl bromide, etc. Nitrosyl halides, oxides containing both sulfur and nitrogen such as nitrosyl sulfuric acid, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, polyphosphoric acid, superphosphoric acid, disuperphosphoric acid, hypophosphoric acid, phosphorous acid, etc. Phosphorous oxides, such as phosphorus oxygen acids, phosphorus pentoxide,
Phosphorus halides such as phosphorus pentachloride, phosphorus trichloride, and phosphorus pentabromide; phosphorus oxyhalides such as phosphorous chloride and phosphorus oxybromide; arsenic oxoacids such as arsenic acid and arsenous acid; and arsenic pentoxide. , arsenic oxides such as arsenic trioxide, chromium oxyacids such as chromic acid, dichromic acid, polychromic acid,
Chromium oxides such as chromium trioxide, chromium pentoxide, chromium dioxide, and chromium suboxide; chromyl halides such as chromyl chloride and chromyl bromide.

Preferred among these inorganic acids and their derivatives are hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, etc., and hydrochloric acid and hydrogen chloride are most preferred. Examples of organic acids and derivatives thereof include the following. Formic acid, acetic acid, propionic acid, butyric acid, valeric acid, lactic acid, glycolic acid, monochloroacetic acid, trichloroacetic acid, acrylic acid, methacrylic acid,
4 lower aliphatic saturated or unsaturated, substituted or unsubstituted monocarboxylic acids, their acid anhydrides and acid halides, such as crotonic acid; sialic acid, malonic acid, succinic acid, pimelic acid, adipic acid, tartaric acid, maleic acid, itacon acids, lower aliphatic saturated or unsaturated, substituted or unsubstituted dicarboxylic acids, their acid anhydrides and acid halides, such as suberic acid; alicyclic saturated or unsaturated carboxylic acids, such as naphthenic acid, hexahydrophthalic acid, norbornene dicarboxylic acid; acid,
Halogen substituted products, acid anhydrides and acid halides thereof: Aromatic monocarboxylic acids such as benzoic acid, toluic acid, styrene carboxylic acid, nitrobenzoic acid, chlorobenzoic acid, hydroxybenzoic acid: phthalic acid, trimellitic acid, pyromellitic acid, Aromatic substituted or unsubstituted carboxylic acids such as nitrophthalic acid and chlorphthalic acid, their acid anhydrides and acid halides; aromatic nucleus-containing aliphatic carboxylic acids such as phenyl acetic acid, atropaic acid, and cinnamic acid, and their logogen substituted products , acid anhydrides and acid halides; these carboxylic acids are sufficiently stable for processing at the metal processing temperatures and can be converted to the gas phase by evaporation or sublimation (even under reduced pressure if necessary); , not only in the free acid form,
Even in the form of acid derivatives such as acid anhydrides and acid halides, they can be used in the treatment of the present invention.

The conditions used for surface treatment of metals in the present invention are generally in the range of room temperature to 100°C, preferably 20 to 80°C.

Of course, it is also possible to carry out the treatment at a higher temperature using an acid or a derivative thereof having a boiling point or sublimation point at a higher temperature. The suitable contact time with the acid vapor varies depending on the temperature, the pressure of the gas phase system and the partial pressure of the acid vapor, but is usually selected from 1 to 60 minutes, preferably from 5 to 30 minutes, in the above temperature range. The treatment can also be carried out in a reduced pressure system or a pressurized system, if necessary. The concentration of acid present in the gas phase during contact is usually 10-5m2 in the above temperature range.
01/l (gas phase) or more, preferably 10-3 m01/l
I? (gas phase) or more. With this kind of surface treatment,
The adhesion of the metal to the resin and the salt water peeling resistance after adhesion are sufficient to reach a sufficient level (following the above contact treatment, the adhesiveness of the metal to the resin is maintained at room temperature, around normal pressure, and in an atmosphere with a relative humidity (RH) of 5 to 50% in the air. Generally, the adhesion and salt water peeling resistance are further increased when stored for 5 minutes or more, preferably 20 minutes or more.The metal plate treated by the method developed by the present inventors has a laminate with a modified olefin polymer. It exhibits a high level of salt water peeling resistance that could never be achieved with a conventional laminate of a metal plate and a modified polyolefin.The modified polyolefin preferably contains a polar group in an appropriate proportion.

These polar groups are, for example, carboxylate groups (-COO
M) - (here, M represents an atom or atomic group selected from hydrogen, ammonium, alkali metals, alkaline earth metals, zinc, aluminum), oxirane ring (-C-C-
), acid anhydride group (Tsuji % J.) o), isocyanate group (
-NCO), urethane bond (-0-C-1), -Si(
0R) 1Xm group (here, R is a group selected from hydrogen, an alkyl group, an aryl group, and a cycloalkyl group, and the plurality of R's may be different from each other.
and m is O≦1. ．． O≦m and 1≦l+m≦3
), hydroxyl group (-0H), amino group (-NR
R'') (here, R and k are groups selected from hydrogen, an alkyl group, an aryl group, and a cycloalkyl group, and the plurality of R's may be different from each other), an imino group (〉N-
R) (where R is the same as above), acid halide group (-CO
X) (where X represents a halogen) and a sulfonate group (-SO3M) (where M represents an atom or atomic group selected from hydrogen, ammonium, alkali metals, alkaline earth metals, zinc and aluminum) be able to. Among these polar groups, carboxylate groups, acid anhydride groups, and oxirane rings are preferred. Also,
Two or more types of each polar group may coexist in the modified polyolefin. Raw material polymers for modified olefin polymers include:
Examples include:

As a homopolymer, a polyethylene wax with an intrinsic viscosity [η] (value determined from the measured value of a decalin solution at 135°C) of usually 0.07 to 1, O, [η] usually 0.01 to 0.5 is used. Polypropylene wax, [η] Usually 1.
Copolymers include wax-like, resin-like and Wax-like, resinous and rubber-like materials consisting of ethylene-1-butene copolymers with a 1-butene unit content of usually not more than 30m01%, a propylene unit content of 70m01%
Wax-like, resin-like, and rubber-like products made of the above propylene-ethylene copolymers; Wax-like, resin-like, and rubber-like products made of ethylene-conjugated diene copolymers with a conjugated diene unit content such as butadiene, usually 5m01% or less thing,
Wax-like, resin-like and rubbery substance.

The above conjugated diene or non-conjugated diene unit content, usually 5
A rubber-like material consisting of an ethylene-propylene-diene copolymer with m01% or less. These polymers and copolymers include, for example, Mll (190°C, under a 2160f7 load,
Resin extrusion amount for 10 minutes) 4 to 14 Hi-Zex8
Examples include various olefin polymers such as various brands, 3 to 15 brands of NeO-Zex (trademark), Hi-WO (trademark), and Mitsui EPT (trademark). Of course, two or more of these polymers may be used as a composition. Other copolymers include ethylene-vinyl acetate copolymers with a vinyl acetate unit content of usually 30 m or less, such as various brands of Evaflex 9, partially or completely saponified products thereof, and ethyl acrylate unit content of usually 10 m
Examples include ethylene-ethyl acrylate copolymer with a concentration of 0.01% or less. These copolymers can also be used as a composition of two or more types. These modified olefin polymers can be used by themselves to produce laminates, and can also be used as a composition with other unmodified olefin polymers. Unmodified olefin polymers hardly adhere to metal bodies, and of course there is no problem with salt water peeling resistance, but by blending a small amount of the above modified olefin polymer, a high degree of salt water peeling resistance can be obtained. That is surprising.
The blending ratio of modified olefin polymer and unmodified olefin polymer varies depending on the type of each, but if we take carboxyl-modified polyethylene (including acid anhydride group-modified polyethylene) and polyethylene as an example, carboxyl The group content (acid anhydride groups are counted as 2) in the entire composition,
It is usually sufficient to select 10-3 to 10-1 meq/t.

The unmodified olefin polymer may be the same as the modified raw material polymer. A metal-resin laminate for evaluating the effects of the laminate obtained by applying the metal surface treatment method developed by the present inventors was prepared as follows.

A metal plate (140 mm x 1
40m7! L x 1 mm) was placed on the hot plate of a compression molding machine set at 200°C, and about 287 resin was spread almost horizontally on the metal plate and preheated for 5 minutes to melt the resin, and then the pressure was 40 kg. /C! Pressing with TLG was performed for 5 minutes to obtain a laminate in which a resin layer with a thickness of about 1 mm was bonded to the metal plate.

Measurement of interlayer adhesion and salt water peeling test of the laminate of metal and resin surface-treated by the method of the present invention were carried out as follows.

Measurement of interlayer adhesion strength A laminate (140 mm x 140
A specimen with a width of 20 mm was cut from 20 mm) and peeled at a peel angle of 180 cuts and a tensile speed of 50 mm/70 in an atmosphere of 23 °C.
7! Measure the peel strength (Kg/?).

Saltwater Peeling Test Cutting a Sample for Interlaminar Adhesion Measurement A sample with a width of 20 m1 was cut from the original laminate, immersed in a saline solution with a concentration of 3%, and stirred at 1000 rpm at a temperature of 60°C for a predetermined period of time. Leave to stand and evaluate the width of natural peeling from the edge of one of the specimens in Mm/day.

The immersion test was not continuous immersion, but a total of 8 cycles, with one cycle consisting of 8 hours of immersion followed by 16 hours of standing in the air. This test is considered to be more severe than continuous immersion. It is a kind of accelerated test in that it involves changes in temperature, changes in moisture content, changes in oxygen concentration, etc. Example 1 Concentrated hydrochloric acid (
A hub (#120) polished steel plate (JISG-310
1, 140mm x 140mm x 1mm), and set the temperature to 2.
After being left at 0°C for 30 minutes, the temperature was increased to 50°C, relative temperature (
RH) Leave in 25% air for 24 hours.

Modified polyethylene containing maleic anhydride units, MI4, density 0.937/Ml was applied to the treated steel plate by the method described above.
An original laminate was obtained by laminating 28y with an acid value of 5×10 −3 meq/7.

Samples cut from the original laminate were evaluated using the test method described above.

Comparative Example 1 For comparison, a laminate was prepared in the same manner as in Example 1 using a steel plate that was not brought into contact with hydrogen chloride vapor, and specimens cut from it were tested in the same manner.

As a result, the initial peel strength (interlayer adhesion strength) of the laminate in Example 1 was 10.6k9/CIrL. In the comparative example, there was no significant difference at 7.3k9/CrrL, but the salt water resistance peeling width was 0 mm/day in Example 1, while it was 30 mm/day in Comparative Example 1, which was a large difference. Examples 2 to 8 The same steel plates and the same resin compositions used in Example 1 were subjected to surface treatments with various acid vapors and left to stand under the same conditions.

The results are shown in Table 1. Table 1 shows that the treatment method of the present invention is sufficiently effective even when various acids are used.

Examples 9 to 12 Table 2 shows the results of confirming the effects of the present invention using modified polyethylenes containing maleic acid units with various MIs, densities, and acid values.

Table 2 shows that the steel plate treated by the method of the present invention exhibits excellent initial adhesion and salt water peeling resistance to various modified polyethylenes.

Example 13 Modified polypropylene containing maleic anhydride units, MI (230°C, 2160t load) 30t/10m
m, density 0.91 t/ml, acid value 5 x 10-3 meq/
A laminate was prepared in the same manner as in Example 1, except that t, 28f was used instead of modified polyethylene.

The initial peel strength of a specimen cut from this laminate at 40° C.* atmosphere was 9.6 k9/CTrL, and the salt water peel width was 0 m1fL/day, which was recognized to have sufficient performance for practical use. :Polypropylene is hard at room temperature and cannot be peeled off, so it was tested at 40°C. Examples 14 to 19 and Comparative Examples 2 to 7 Similar tests were conducted using the method of Example 1, but using an ethylene polymer containing carboxyl groups, carboxylate groups, and acid anhydride groups instead of modified polyethylene. The results are shown in Table 3.

As a comparative example, Table 3 also shows the test results of laminates using steel plates that were not subjected to the surface treatment of the present invention for each modified ethylene polymer.

Claims (1)

[Scope of Claims] 1. A salt water-releasable laminate comprising an olefin polymer and a metal body whose surface has been subjected to contact treatment with a vapor phase of a substance selected from acids and derivatives thereof. 2. A method for producing a salt water-resistant laminate, which comprises bringing the surface of a metal body into contact with a vapor phase of a substance selected from acids and derivatives thereof, and then laminating an olefin polymer on the surface.