JPS596240A - Modified polyethylene resin composition and bonding method using the same - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent corrosion proof performance and adhesion to metal, by grafting an unsaturated carboxylic acid (derivative) onto a blend of a specified ethylene polymer with polyethylene. CONSTITUTION:An ethylene polymer (A) having an MI of 0.1-30 and a density of 0.90-0.945 obtd. by copolymerizing ethylene with 1-12mol% of 4C or higher alpha-olefin in the presence of a catalyst consisting of a combination of an org. Al compd. with a solid catalyst component contg. Mg, Ti and halogen, is blended with a copolymer (B) consisting of ethylene and a small amount of an alpha-olefin and having an MI of 0.1-50 and a density higher than that of component A in a ratio of B/A+B of 0.05-0.35. 0.05-5wt% unsaturated carboxylic acid (derivative) is grafted onto the above blend in the presence of a radical generating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified polyurethane resin composition having excellent adhesive properties and anticorrosive properties, and further relates to a method for bonding a metal material such as a metal or steel pipe to a polyethylene resin.

Conventionally, it is well known that metal materials such as steel pipes are coated with polyethylene resin as an anti-corrosion protection material, but polyethylene resin itself is required to have adhesive strength, so unsaturated carboxylic acid such as maleic anhydride is used as an adhesive component. Adhesion is usually achieved through a polyethylene layer modified with an acid or a monomer with various polar groups.

Furthermore, pretreatment such as surface treatment of the metal material and application of a primer may be performed. Various resins such as high-pressure low-density polyethylene, low-pressure high-density polyethylene, and mixtures thereof with rubber components and the like are used as raw materials for modified polyethylene resins used in such applications. However, there are few resin components that have been proposed to date that have a good balance between raw adhesive strength and adhesive durability; some have excellent adhesive strength but have poor durability; others have good durability but lack adhesive strength It was customary to do so. Tree brother EJ
In an attempt to improve these points, foil et al. achieved the present invention by modifying a specific polyethylene resin formulation to create a modified polyethylene resin composition with excellent adhesive durability.

That is, the invention of the present invention involves copolymerizing ethylene and a small amount of an olefin with a carbon number of 4 or more using a catalyst that combines a solid catalyst component containing magnesium, titanium, and a halogen, and an organoaluminum compound. Obtained melt index 0.1-30, 'MW O, 910-0.9
40 polyethylene and ethylene alone, or a copolymer of a small amount of α-olefin and ethylene, with a melt index of 0.1 to 50, and the above polyethylene (
4) A polyethylene composition consisting of polyethylene (CB) having a higher density, in which the polyethylene (T) in the total composition weight is 0.05 to 0.35 in the ratio of B / A + B
and unsaturated carboxylic acid or its wire conductor is grafted onto polyethylene (b) and/or 1103),
The amount of grafting is 74 to the total polyethylene weight and 0.05
This is a modified polyethylene resin composition with improved adhesive performance, characterized in that the adhesive strength is 5%.

This is a method to completely bond metal and polyethylene resin by combining resin resin and epoxy primer with silk.

Polyethylene (A) used in the present invention is obtained by copolymerizing ethylene with a small amount of α-olefin having 4 or more carbon atoms using a catalyst component containing magnesium, titanium, and halogen. It is a low-density polyethylene with an Intex of 0.1 to 30 and a density of 0.90 to 0.945, and the JQI standard monomer content is about 1 to 12 mol. The τ parameter of the present invention is 0.9.
A density of 10 to 0.940 is desirable. α- to copolymerize
As the olefin (butene, pentene, hexene, octene, etc., copolymers of butene, hexene, mectene, etc.) are preferred. Copolymers of mixtures of these α-olefins may also be used.

Polyethylene (BIU) is a homopolymer of ethylene or a copolymer with a small amount of α-olefin,
The melt index is 0.1 to 50, the density is higher than that of polyethylene, preferably 0.945 or more, and the catalyst may be the same as that used for producing blue polyethylene. , or something else is fine. Propylene, butene, etc. are used as the α-molefin used in the copolymerization, but higher α-olefins may also be used. These wide olefins are usually used in such a manner that their content in the polymer is less than 10 mol, preferably less than 1 mol.

In the present invention, polyethylene is mixed and used at a ratio of (8)kB/A10B=(LO5 to 0.35 (weight)).

In the present invention, the mixing ratio is λ, and if there is too little polyethylene (F), the water resistance performance among the adhesive durability will be poor, and if it is too much, the heat resistance will decrease, so it is not good for freezing. The range of o, i to 0.25 is most preferred. As for the mixing method, there is a method in which the polyethylene and Φ) are prepared separately and then mixed together, and a method in which a multi-stage polymerization method is used during the polymerization reaction and two types of polyethylene are sequentially produced on the same catalyst. Very good.

Modification (grafting) of polyethylene (C) and (B) is carried out by contacting maleic anhydride or the like with a radical generator. Modification methods include methods known in the art such as a method in a solution, a method in a slurry, and a melt mixing method. This can be done using any of the following methods.

In addition, when performing this modification and mixing, the polymer (4
), 03), either one or both of them may be denatured and then mixed, or both may be mixed in advance and then denatured.

It is desirable that the amount of the unsaturated carboxylic acid graft (4) falls within the range of 0.05 to 5 wt% based on the total amount of the polyethylene mixture. If the amount of unsaturated carboxylic acids is too small, the adhesive force will decrease, and if it is too large, undesirable phenomena such as coloring will occur, while the effect of improving the adhesion force will be reduced. fi 0.0
It is 7-1 wt%.

Examples of unsaturated carboxylic acids and derivatives thereof used in the present invention include maleic acid, fumaric acid, acrylic acid, methacrylic acid, citraconic acid, endobicyclo(2,2,1)
Examples include unsaturated carboxylic acids such as 5-hegetene-2,3-dicarboxylic acid, and derivatives thereof such as anhydrides, esters, and amides. Among these, maleic anhydride and acrylic acid are preferred, with maleic anhydride being particularly preferred.

The modified polyethylene resin composition of the present invention can be used for metal covering materials (
Although it is effectively used as an adhesive layer for (polyethylene resin), it is obvious that stabilizers, colorants, fillers, and various other additives can also be added when used for such purposes.

The present invention will be explained in more detail below with reference to Examples.

In addition, the melt index is ASTM D-1238-5.
7'l', and the density is A51.
Measured according to STM, D 1505.

Example 1 Using a solid catalyst component obtained by the reaction of magnesium diethoxide and titanium tetrachloride and triethylaluminum, ethylene and butene-14,5 were prepared in isobutane.
Copolymerized with molch, melt index 0.8,
A copolymer with a density of 0.920 was obtained. [Polyethylene (4
)] Using the same catalyst, copolymerize ethylene and 0.3 mol of propylene to achieve a melt index of 20° and a density of 0.9.
70 copolymers were obtained. (Polyethylene (B)) 80 parts by weight of polymer, ■) 20 parts by weight of polymer, 0.15 parts by weight of maleic anhydride, 0.025 parts by weight of α,α'-bistershaributylbaroxyparadiisoglobilbenzene
Parts by weight were mixed and melt-kneaded at 210° C. using a 30Mφ, φ=24 single-screw full-flight screw extruder.

The melt index of the modified polyethylene resin composition is 1
．． 2. The amount of graft polymerization of maleic anhydride is 0.12wt
It was Chi.

Adhesive strength and heat resistance were measured as follows.

After the surface of the steel plate (10 mm thick) is plasted with a 1.3 mm steel grid, an epoxy primer (Epotherm P 330 manufactured by Mitsubishi Chemical Industries, Ltd., Evotherm is a registered trademark) is applied on top to a thickness of approximately 30 μm. The coated material was heated to about 140'C in a heating furnace, and then a molten sheet of 2J@ consisting of the modified polyethylene resin composition and high-density polyethylene (
A laminate of a steel plate and polyethylene was produced by bonding a modified polyethylene resin composition 4 ( ) θ μ, high density polyethylene 4 mm, resin temperature 230° C. so that the epoxy primer and the modified polyethylene resin composition were in contact with each other.

After cooling the tf4 layered product to room temperature, the adhesive strength and heat resistance of the layered product were evaluated.

Adhesive strength was determined according to the conventional method, with a peeling speed of 10 m and a leakage of 1 n.
Measured by 0° peel test. Heat resistance was evaluated by cutting out a 100 mm x 1 (10 mm) test sample from the laminate using a band saw, leaving it in an oven at 100°C and observing how it peeled off from the end. The conditions were observed and rubbed.The results were expressed as the number of days in which peeling was observed.

The cathode peeling performance was evaluated by using a cathode peeling test device configured as shown in FIG.

In the figure, l is a coating layer, 2 is a steel plate, 3 is a hole (with a diameter of 5 mm), 4 is a glass cylinder, 5 is a triple saline solution, 6 is an anode (platinum), and 7 is a DC power source (3■).The results are shown below. -1.

Examples 2 and 3 An experiment was conducted in the same manner as in Example 1 except that the ratio of raw material polyethylene was changed, and the results are shown in Table 1.

Example 4 Maleic anhydride was grafted only to polyethylene (I3) to create modified polyethylene with a maleic anhydride content (1.82 wt), and the same was mixed with polyethylene (4) in the same ratio as in Example 2. An experiment was conducted in the same manner as in 1 to evaluate the adhesive strength.The results are shown in Table 1.

Example 5 Same polyethylene as Example 1, polyethylene (J3)
Polyethylene (4) alone was modified with maleic anhydride (same as in Example 1, i.e. (4) 80, maleic anhydride 0.15, and peroxylide 0-025 parts by weight were kneaded in the same way. Grafting amount 0. 14 wt%. Pelletization) and (6) were blended under the same conditions. The results are shown in Table 1.

Comparative Example 1 An experiment similar to Example 1 was conducted except that only polymer (2) was used. The results are shown in Table-1.

Comparative Example 2 An experiment similar to Example 1 was conducted except that only Polymer 03) was used. The results are shown in Table-1.

Comparative Example 3 Low density polyethylene manufactured by high 11-radical polymerization method (melt index [1,45, density 0.922)
The same experiment as in Example 1 was conducted except that Polymer (A) was used instead of Polymer (A). The results are shown in Table-1.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the cathode peeling test device. 1... Covering layer 2... Steel plate 3... Hole
4...Glass cylinder 5...3
% saline solution 6... Anode 7... DC power supply - 2 pieces

Claims (6)

[Claims] (1) A melt index of 0 obtained by copolymerizing ethylene and a small alpha-olefin having 4 or more carbon atoms using a catalyst that combines a solid catalyst component containing magnesium, titanium, and halogen with an organoaluminum compound. .1
~30, polyethylene with a density of 0.910 to 0.940 (
) and polyethylene (g), which is ethylene alone or a copolymer of ethylene with a small amount of α-olefin, and has a melt index of 0.1 to 50 and a higher density than the above polyethylene (4). A polyethylene composition consisting of B/A polyethylene (5) in the total composition weight
The ratio of A modified polyethylene resin composition with improved adhesive performance, characterized in that the adhesive strength is 0.05 to 5. (2) The composition according to claim (1), wherein the unsaturated carboxylic acid is maleic anhydride and/or acrylic acid. (3) The composition according to claim 11, wherein the unsaturated carboxylic acid is maleic anhydride. (4) The composition according to claim (2) or (3), wherein the proportion of polyethylene [F]) based on the total weight of the composition is 0.1 to 0.25. (5) Grafting amount of maleic anhydride is 0.07 to 1
Claims (31) or (41) that are heavy
Compositions as described in Section. (6) Claims (e) (1), (e) (2), (e) (3) in which unsaturated carboxylic acids are grafted to at least polyethylene in polyethylene and (g).
The composition according to item 51, item 4) or item 51. Melt index 0.1 obtained by copolymerizing α-olefins of 4 or more
~30, polyethylene with a density of 0.910 to 0.940 (
) and a polyethylene composition consisting of ethylene alone or a copolymer of a small amount of olefin and ethylene, which has a melt index of 0.1 to 50 and a higher density than the polyethylene (4) above. , polyethylene (B) in the entire composition is in a ratio of B/A+B of 0.05 to 0.35, and polyethylene (
5) and/or (a modified polyethylene resin composition to which an unsaturated carboxylic acid or a wire conductor thereof is grafted, and the amount of grafting is 0.05 to 5% based on the total weight of the polyethylene, and an epoxy glymer) A method for bonding polyethylene resin and metal, which is characterized by bonding metal and polyethylene resin in combination.