JPH0433802B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a modified polyolefin. Specifically, the present invention relates to a method for producing a modified polyolefin that has improved adhesion to polar polymers, metals, inorganic fillers, etc., and has improved dyeability and paintability. A method for obtaining a modified polyolefin by reacting a copolymer of an α-olefin and an unsaturated carboxylic acid with an amine is known. For example, Tokuko Sho 39-22588
The publication describes a method for obtaining polyolefins that give molded products with good hardness, tensile strength, transparency, etc. by reacting specific diamines.
Publication No. 1540 proposes a method for improving the dyeability, heat, light, and oxidation stability of polyolefins by reacting them with specific diamines. A method for obtaining a modified polyolefin by reacting a polyolefin with a mixture or reaction product of an unsaturated carboxylic acid and an amine is also known. For example, JP-A-56-135511 discloses a method of obtaining a polyolefin with good adhesive properties by using a specific diamine. However, according to studies conducted by the present inventors, when polyolefin is reacted with unsaturated carboxylic acids and diamines used in the conventional method, the effect of improving adhesion is insufficient, or Gel-like particles were formed, which spoiled the appearance. As a result of intensive studies aimed at solving these drawbacks, the present inventors have found that by using piperidine derivatives such as aminopiperidine and aminoalkylpiperidine, a modified polyolefin with fewer such drawbacks and improved adhesive properties can be obtained. The present invention was achieved by discovering that That is, the gist of the present invention is to combine polyolefin with maleic acid or its anhydride and the general formula X-(Y) _o -NHR in the presence of a radical initiator. (represents an optionally substituted 3- or 4-piperidinyl group, Y represents an alkylene group or arylene group, R represents an alkyl group or aryl group, and n is 0 or 1). A method for producing a modified polyolefin, characterized by reacting with. The present invention will be explained in detail below. The polyolefins used in the method of the present invention include high density, medium density and low density polyethylene;
Olefin polymers such as polypropylene, polybutene-1, poly4-methylpentene-1, etc., olefin copolymers such as ethylene-propylene random copolymers, block copolymers, ethylene-propylene-diene copolymers, etc.; It is a mixture of these. In the piperidine derivative represented by the general formula [], the number of carbon atoms of the alkyl group and aryl group as a substituent of the piperidinyl group or the alkyl group and aryl group represented by R is preferably 1 to 6, and Y is carbon Preferably, it is an alkylene group or a phenylene group having 1 to 6 atoms. Specifically, 3-aminopiperidine, 4-aminopiperidine, 3-(aminomethyl)piperidine,
4-(aminomethyl)piperidine, 3-(2-aminoethyl)piperidine, 4-(2-aminoethyl)
piperidine, 3-(3-aminopropyl)piperidine, 4-(3-aminopropyl)piperidine,
3-(4-aminobutyl)piperidine, 4-(4-
aminobutyl)piperidine, 3-(P-aminophenyl)piperidine, 4-(P-aminophenyl)
Examples include piperidine, 4-amino-2,5-dimethylpiperidine, and the like. In order to react a polyolefin with maleic acid or its anhydride (hereinafter abbreviated as "maleic acid") and a piperidine derivative represented by the above general formula, the polyolefin is usually first reacted with maleic acid and then reacted with the piperidine derivative. Alternatively, a method is used in which a polyolefin is reacted with a mixture or reaction product of maleic acid and a piperidine derivative. The reaction of polyolefin with a mixture or reaction product of maleic acid or an unsaturated carboxylic acid and a piperidine derivative can be carried out by a known method. For example, the reaction can be carried out after or while previously subjecting the polyolefin to peroxidation treatment or various radiation treatments, but it is preferably carried out in the presence of a radical initiator. The radical initiator is added to the polyolefin in the presence or absence of a solvent by kneading at high temperatures. The kneading is carried out using a conventional method such as a Banbury mixer, a single-screw or twin-screw extruder, and the like. As a radical initiator, oxygen, benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, α,α'-bis(t
-butylperoxyisopropyl)benzene,
2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-
Peroxides such as di(t-butylperoxy)hexyne-3 are used. The amounts of maleic acid and piperidine derivatives used in the reaction are usually selected from the range of 0.01 to 10% by weight based on the polyolefin to be modified. The modified polyolefin thus obtained is a polar polymer such as polyamide, polyester, etc.
It has good adhesion to metals such as aluminum and iron, and inorganic fillers such as charcoal and talc, and has good dyeability and paintability, so it can be applied to various uses. Hereinafter, the present invention will be explained with reference to Examples. In addition, in the examples, the adhesion test of the modified polyolefin was conducted as follows. That is, a modified polyolefin film formed into a film with a thickness of 50μ is placed on a polyester film with a thickness of 25μ.
It was pressed at 0.degree. C. and subjected to a T-peel test using an Instron universal tensile tester. The larger the peel resistance value, the better the adhesiveness. Furthermore, in the examples, all "parts" mean "parts by weight." Example 1 Melt flow index (hereinafter abbreviated as MFI)
JIS-K6758) Mix 100 parts of 0.65 g/10 min polypropylene powder, 0.50 parts of maleic anhydride, 0.075 parts of α,α'-bis(t-butylperoxyisopropyl)benzene, and 1.0 parts of ethylene glycol dimethacrylate. The mixture was melt-kneaded at 220°C using a single-screw extruder. A portion of the obtained pellets was pulverized and extracted with acetone to remove unreacted maleic anhydride. According to an infrared absorption spectrum, the maleic anhydride content in the reaction product was 2500 PPM. Next, 4-
0.70 part of (aminomethyl)piperidine was mixed and melt-kneaded at 220°C using a single-screw extruder. The MFI of the final reaction product obtained is 1.2,
In addition, in the infrared absorption spectrum, the absorption at 1785 cm ^-1 due to maleic anhydride disappears, and a new absorption at 1700 cm ^-1
absorption was observed. When we conducted an adhesion test with polyester film using the reaction product obtained in this way, we found that
Peeling resistance was 0.8 kg/cm, indicating good adhesion. Examples 2-4 Example 1 was repeated, but the amounts of maleic anhydride, peroxide and 4-(aminomethyl)piperidine were changed as shown in Table-1. Table 1 shows the results of an adhesion test with a polyester film using the obtained reaction product.

[Table] ** Maleic anhydride modified polypropylene
Example 5 Example 1 was repeated for 100 parts, but 4-(aminomethyl)
0.70 part of 3-aminopiperidine was used instead of piperidine. When an adhesion test with polyester and film was conducted using the obtained reaction product, the peeling resistance was 0.7 kg/cm. Comparative Examples 1-2 Example 1 was repeated, but in Comparative Example 1, 0.70 parts of hexamethylene diamine was used instead of 4-(aminomethyl)piperidine, and in Comparative Example 2, no piperidine derivative was used. The results are shown in Table 2, and a large number of gel-like particles were observed in the film obtained from the reaction product of Comparative Example 1. Also, the adhesiveness was somewhat insufficient. The adhesion of the reaction product of Comparative Example 2 was poor.

[Table] ** Maleic anhydride modified polypropylene
Example 6 Example 1 was repeated for 100 parts, but instead of polypropylene, melt index (JIS-K6760) 4, density
0.92 polyethylene was used, and the melting temperature in the extruder was 200°C. No ethylene glycol dimethacrylate was used. An adhesion test with a polyester film using the obtained reaction product showed good adhesion, with peel resistance of 0.9 kg/cm. Example 7 Example 1 was repeated but with maleic anhydride and 4-
(aminomethyl)piperidine rather than separately,
At the same time, it was mixed with polypropylene and reacted.
When we conducted an adhesion test with polyester film using the reaction product, the peel resistance was 0.7.
Kg/cm, showing good adhesion.

Claims (1)

[Claims] 1. In the presence of a radical initiator, a polyolefin is treated with maleic acid or its anhydride and the general formula
(Y) _o -NHR (wherein, X represents a 3- or 4-piperidinyl group optionally substituted with an alkyl group or an aryl group, Y represents an alkylene group or an arylene group, and R represents an alkyl group or an aryl group) 1. A method for producing a modified polyolefin, which is characterized by reacting the modified polyolefin with a piperidine derivative represented by the following formula (n is 0 or 1). 2. The method according to claim 1, characterized in that polyolefin is reacted with a reaction product of maleic acid or its anhydride and a piperidine derivative.