JPS602330B2 - Salt water-resistant polyolefin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyolefin composition that exhibits excellent salt water release resistance when laminated to metal.

BACKGROUND ART Conventionally, in order to protect the surface of water-conducting steel pipes and the like from corrosion, methods of coating the metal surface with a corrosion-resistant resin such as polyolefin have been studied.

Since polyolefin does not have polarity on its surface, it cannot firmly adhere to the surface of metal and cannot be coated with a coating that can withstand practical use. In order to solve this drawback, measures have been taken to introduce polar groups, such as carboxyl groups or carboxylic acid anhydride groups, into the resin. Although it is possible to achieve a certain level of adhesion of the polyolefin to the metal surface by this measure, the water peeling resistance, especially the salt water peeling resistance, which is an even more important practical requirement, does not reach a sufficient level. Therefore, in order to solve this drawback, a measure is often taken to apply a primer having affinity to both the metal and the polyolefin to the metal surface. However, this primer treatment results in an additional process, resulting in a decrease in productivity and an increase in product price. The inventors of the present invention have arrived at the present invention as a result of intensive studies aimed at creating a polyolefin composition that exhibits sufficient salt water peeling resistance without applying any treatment such as a primer to the metal surface.

The present invention contains [a' carpoxyl group or a group derived from carpoxyl group (provided that the acid value is 0.5 or more).

) weight part of olefin polymer 10 and 'b' halogen-containing compound of divalent metal (however, CaC12, MgC12
, remove 12 from S. ) 0.05 to 5 parts by weight of a salt water-releasable polyolefin composition. An olefin polymer containing a carboxyl group or a group derived from a carboxyl group (hereinafter referred to as a hydrophilic polymer), which is the component 'a', is, for example, an olefin polymer that is dispersed in an aqueous state, in an organic solvent solution, or in a molten state. (i) obtained by contacting with oxygen or oxygen-containing gas in
)' Olefin polymer oxide and (ii) a compound selected from unsaturated aliphatic carboxylic acids or derivatives thereof (
(hereinafter referred to as an acid-based compound), a copolymer of an olefin and an acid-based compound itself, or one or more of the above... to (iii) of 0 and another olefin polymer. Any composition may be used.

When this hydrophilic polymer is used alone, its acid value is usually 0.5 to 150, preferably 5 to 14 on the basis of monovalent carboxylic acid units, and divalent carboxylic acids or their anhydrides. The unit standard is preferably 0.5 or 30. When used in the form of a composition with other olefin polymers, the composition should be prepared so that the acid value of the composition is usually 2 x 10-3 to 1, preferably 0.5 to 10. Bye. To prepare the composition of the present invention, a chlorine-containing compound of a divalent metal is generally added in an amount of 0.05 to 5 parts by weight, preferably 0.1 parts by weight, per 100 parts by weight of a hydrophilic polymer.
or 1. If the weight part is used, normal salt water peeling resistance can be sufficiently achieved.

In the present invention, the compounds (acidic compounds) selected from unsaturated aliphatic carboxylic acids or derivatives thereof that may be used to produce a hydrophilic olefin polymer include free acids, acid hydrates thereof, and acid halogens. compounds, acid amides, imides, partial esters, salts, and partial hydrolysates thereof, and these may coexist within the same molecule.

For example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, nozaconic acid, citraconic acid, itaconic acid, 3-cyclohexenecarboxylic acid, 4-cyclohexenedicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, maleic acid, diyl chloride, maleimide, monomethyl maleate, sodium acrylate, calcium acrylate, zinc acrylate, potassium methacrylate, calcium methacrylate, zinc methacrylate, potassium maleate, zinc maleate, partial hydrolysates thereof can be exemplified. In the present invention, the olefin polymer is a single 1-olefin such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, etc., which usually has no carbon atoms and contains silica solids. Polymers and copolymers, such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, propylene-1-butene copolymer, ethylene-4 -Methyl-1-bentene copolymer, 4-methyl-
1-pentene-1-decene copolymers, copolymers of the above-mentioned 1-olefins and small amounts of diolefins, such as ethylene-butadiene copolymers and propylene-butadiene copolymers, and various homopolymers thereof and various copolymers, and may be a crystalline or non-crystalline composition.

Although the wax-like material does not pass the adhesive evaluation based on tensile strength, it is found to be sufficiently effective using other evaluation methods. In these crystalline polyolefins, polyethylene has an intrinsic viscosity of a decalin solution at 135°C, usually 0.5 to 5.0, preferably 0.7 to 3.0, an X-ray crystallinity of 60% to 85%, and a density of 0.90 None, 0.9
7 nights/me, preferably 0.92 no, then 0.96 ta' mine. In addition to ethylene units, this polyethylene contains 1-olefin units, such as polyethylene units. Copolymers containing pyrene units, 1-butene units, butadiene units, etc. may be used, but the copolymers are limited to those that exhibit non-rubber-like properties in normal state. What is polypropylene?
Usually 0.5 to 10, preferably 1.0 to 4.
uX-ray crystallinity: Normally 50 None, 60%, Density 0.90
Copolymers with styrene usually have an ethylene unit content of 8 hol% or less.

The term chlorine-containing compounds of divalent metals is a comprehensive concept, and includes not only dichlorides but also their hydrates, oxychlorides, complexes of chlorides and hydroxides, rust aggregates, and their hydrates. It refers to compounds containing a bond between a divalent metal and chlorine, such as a complex of a chloride and an oxide, a combination thereof, a hydrate thereof, a double chloride, a fin chloride, a hydrate thereof, etc.

Preferred are dichlorides and their hydrates. The mechanism by which these chlorine compounds contribute to improving salt water peeling resistance is not clear, but when they are blended into the 'a' and 'b-components and melt-molded, they generate components such as hydrogen chloride. It is assumed that a suitable treatment is applied to the metal surface.

Two or more types of divalent metal chlorine-containing compounds can be used in combination.

The metals constituting the compound include Group 2 metals of the periodic table, such as magnesium, calcium, barium, strontium, zinc, etc., Group 4 metals, such as tin (0), lead, Group 7 metals, such as manganese, and Group 8 metals. Examples of metals include iron (0), cobalt (0), and nickel (0), among which magnesium, calcium, zinc,
Iron(0) is preferred. However, the dihalides of magnesium, calcium, and strontium are excluded as chlorine-containing compounds of divalent metals. Adhesive strength (measured as peel strength) and salt water peeling resistance (measured during salt water peeling) in the laminate of the polyolefin composition of the present invention and metal
A metal-resin laminate for evaluation is prepared as follows.

Steel plate with the specifications and treatments described below (14 ribs x 1
4 sides x 1 side) was placed on the hot slope of a compression molding machine set at 20 mm, and about 28 mm of resin was spread out almost horizontally on a metal plate and preheated for 5 minutes to melt the resin. After that, pressing was carried out for 5 minutes at a pressure of 40 k9' G to obtain a laminate in which a resin layer of about 1 skin thickness was crimped onto the steel plate. The peel strength measurement and salt water peel test of the obtained laminate are carried out as follows.

A steel plate (1 side thickness) prepared for peel strength measurement and a hydrophilic polyethylene report (
Cut out a sample of the middle 2nd cape from the laminate with about 1 fence thickness).
Peeling angle 180o, pulling speed 5 in 2-chi○ atmosphere
Peel strength (k9') is measured in units per minute.

Saltwater Peeling Resistance Test Samples for Peeling Strength Measurement were Cut from Samples A medium-sized 20mm sample was cut from the layered material, immersed in saline solution with a concentration of 3%, and soaked in saline water at a temperature of 60 oo and 100 pm. The specimen was left to stand for a predetermined period of time, and the inside of the specimen, which was naturally peeled off from one edge, was evaluated by salt water peeling rate (Waki no Hi, hereinafter abbreviated as PR).

The immersion test was not carried out using a continuous immersion groove, but was conducted for a total of 8 cycles, with each cycle consisting of leaving the sample in the air for one vowel after 8 hours of immersion. This test is considered to be more irritating than Renzoku dihin. It is a type of accelerated test in that it involves changes in temperature, changes in moisture content, changes in oxygen concentration, etc. Example 1 Hydrophilic polyethylene grafted with maleic anhydride (acid value 0.7, density 0.96 #', MIIO 1/1 h)
In) was dry blended with various amounts of ferrous chloride listed in Table 1 to prepare a composition with a total of 100 parts by weight.
The laminate was degreased with xylene-acetone and laminated on a laminate (14 ft x 140 ft x 1 sq.) according to the laminate preparation method described above, and the mysterious piece was cut out according to the same method.

This sample was subjected to the above test to measure initial peel strength (PSo) and salt water peel rate (PR).

The results are shown in Table 1. Comparative Example 1 The same procedure as in Example 1 was carried out except that no metal chloride was added. As a result, the initial peel strength was 4.4k9/2, and the salt water peeling rate was >3.
It was found that it could not withstand use if the number of ships per day exceeded 30.

Table 1 Example 2 Hydrophilic polypropylene grafted with acrylic acid (oxidation 1.0, density 0.91 mm/hin, skin 6 mm/1 hin) 1
0 parts by weight of the metal chlorides listed in Table 1. Table 2 shows the results of the same procedure as in Example 1 except that the composition was prepared by adding a part by weight.

2 Loss of polypropylene is difficult to produce 18 liters at room temperature, so the results are the peel test results at 40°C.

Claims (1)

[Scope of Claims] 1 (a) 100 parts by weight of an olefin polymer containing a carboxyl group or a group derived from a carboxyl group (oxidation is 0.5 or more); and (b) a divalent metal. Halogen-containing compounds (however, CaCl_2, MgCl
_2, excluding SrCl_2. ) A salt water releasable polyolefin composition comprising 0.05 to 5 parts by weight.