JPS6154804B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to an olefin interpolymer (hereinafter referred to as
(simply referred to as olefin interpolymer). Olef interpolymers generally have the drawback of poor oil resistance (solvent resistance) and adhesion, but this drawback has been overcome, and in addition, this type of polymer has relatively good weather resistance, heat resistance, and fatigue resistance. Attempts have been made for a long time to further improve various properties such as ozone resistance and to diversify their usefulness and applications. For example, methods of blending this type of polymer with other polymers, methods of mixing acrylic acid or quinone dioxime and cross-linking with peroxide are known, and these methods can be easily applied to sealants, etc. This is done at the same time as the kneading process and the vulcanization process. However, the former blending method has the disadvantage of easily causing variations in properties, and although the latter method can improve oil resistance and adhesion, the above-mentioned properties inherent to the terpolymer are not the main characteristics of this type of polymer. Due to the fact that the chains are easily radically cleaved by the peroxide used, hardly any improvement can be expected, and in extreme cases, the properties actually deteriorate compared to those before modification. Moreover, the latter method even had the problem of dangerous handling of peroxide. As a result of extensive research in light of the above circumstances, this invention uses a specific reactive unsaturated compound to form double bonds based on cyclic or acyclic polyenes contained in olefin interpolymers. When the terpolymer was added simply by heating without the aid of a radical initiator such as peroxide, the heat resistance, which is the inherent property of the terpolymer, was improved.
This was done based on the finding that weather resistance, fatigue resistance, etc. can be greatly improved, and oil resistance and adhesiveness, which are disadvantages of this type of polymer, can be sufficiently improved. That is, this invention mixes an olefin interpolymer with a reactive unsaturated compound having at least one functional group selected from hydroxyl group, carboxyl group, nitrile group and epoxy group and having a molecular weight of 10,000 or less, The present invention relates to a method for modifying an olefin interpolymer, which is characterized by carrying out an addition reaction by heating in the absence of a radical initiator. Typical olefin interpolymers to be applied in this invention are terpolymers made of ethylene, propylene or butene-1 and the polyene monomers listed below. Ordinary rubber such as butyl rubber may be included. Specific examples of polyene monomers include dicyclopentadiene, 1,5-cyclooctadiene,
1,1-cyclooctadiene, 1,6-cyclododecadiene, 1,7-cyclododecadiene, 1.
5,9-cyclododecatriene, 1,4-cycloheptadiene, 1,4-cyclohexadiene, norbornadiene, methylenenorbornene, 2-methylpentadiene-1,4,1,5-hexadiene, 1,6-heptadiene, methyl -Tetrahydroindene, 1,4-hexadiene, etc. The reactive unsaturated compound in this invention has at least one reactive carbon-carbon double bond in the molecule, preferably at the end of the molecule, and has highly polar functional groups such as hydroxyl group, carboxyl group, and nitrile group. and epoxy groups, and a molecular weight of 10,000 or less. All of the above functional groups are highly polar with specific polarization in the range of 8 to 13, but it is only by selecting such functional groups that it is possible to improve adhesion and oil resistance. At the same time, improvements in the inherent properties of the terpolymer such as heat resistance and weather resistance can be expected. Other highly polar functional groups whose specific polarization falls within the above range include acid anhydride groups (for example, maleic anhydride), halogens, and amino groups. but,
It is difficult to achieve both of the above properties with these functional groups.For example, acid anhydride groups improve the properties inherent to terpolymers such as heat resistance and weather resistance, but the effect of improving adhesion and oil resistance is very low. It becomes a small thing. Regarding the molecular weight, if it is too large, it may interfere with reactivity and uniform mixing.
Usually less than 10,000 as mentioned above, preferably 1,000
The following are good. Within this range, it may be in the form of a monomer or in any form such as a condensate, an adduct, or a polymer (copolymer). Typical reactive unsaturated compounds include allyl alcohol, hydroxyethyl (meth)acrylate, (meth)acrylic acid or its homopolymer or copolymer, maleic acid, acrylonitrile fumarate, glycidyl (meth)acrylate, and the like. In the present invention, such a reactive unsaturated compound is first blended into an olefin interpolymer and preferably mixed using a mixer that applies shearing force, such as a pressure kneader, mixing roll, Banbury mixer, or the like. The blending ratio varies depending on the type of olefin interpolymer, especially the ratio of double bonds contained in the terpolymer, the type of reactive unsaturated compound, etc.
Usually, the amount is preferably 1 to 40 parts by weight, preferably 5 to 20 parts by weight, per 100 parts by weight of the olefin interpolymer; if it is blended in too much, the original properties of the terpolymer will be impaired. The reactive unsaturated compounds have relatively low molecular weights, and unlike the conventional polymer blending methods, they can be mixed uniformly by the method described above, which has good results in subsequent addition reactions and in eliminating variations in properties. bring. After this mixing, heating is optionally performed during mixing to effect an addition reaction between the reactive unsaturated compound and the olefin interpolymer. It is usually sufficient to heat the heating at 80 to 150°C for about 2 to 12 hours, but it may be heated at a higher temperature or for a longer time if necessary. The modified polymer obtained in this way has improved oil resistance and adhesive properties mainly due to the specific functional group of the added reactive unsaturated compound, and furthermore, the addition reaction is carried out using radical initiators such as peroxides. Since it is carried out only by heating without using a terpolymer, and the heating conditions can be relatively mild, there is almost no problem such as cleavage of the main chain of the terpolymer during the addition reaction. The excellent weather resistance, heat resistance, ozone resistance, fatigue resistance, etc. inherent to polymers are further improved. As described above, according to the method of this invention, it is possible to improve the oil resistance and adhesiveness, which were considered to be major drawbacks of olefin interpolymers, and it is also possible to further improve the inherent properties of the terpolymer, such as heat resistance and weather resistance. Its usefulness increases and it becomes possible to diversify its uses, making it possible to provide modified polymers suitable for various uses such as sealing materials, adhesives, lining materials, and sheet forming materials. Next, examples of this invention will be described. In addition, in the following, parts represent parts by weight. Example 1 EPT1045 manufactured by Mitsui Petrochemicals (ethylene-propylene-dicyclopentadiene terpolymer)
10 parts of acrylonitrile was added to 100 parts, and mixed for 10 minutes while cooling with water on a mixing roll. After that, take it out and put it in a hot air constant temperature bath at 120℃.
The addition reaction was carried out by heating for a certain period of time. The resulting modified polymer was vacuum dried at 100°C and the reaction rate of acrylonitrile was measured to be 75%.
It was hot. Example 2 20 parts of epoxy diacrylic ester having the following structural formula was blended with 100 parts of EPT1045 (mentioned above), mixed for about 10 minutes while cooling with water in a pressure kneader, and then heated to 120°C. The addition reaction was allowed to continue at this temperature for 30 minutes with continued mixing. <Structural formula of epoxy diacrylic ester> The conversion rate of epoxy-diacryl ester in this addition reaction was 85%. The reaction rate is calculated by taking out a part of the addition reaction product and adding it to a polar solvent (ethanol-
The unreacted substances were separated using water), dried at 100° C. for 3 hours, and the heating residue was measured, and calculated according to the following formula. Reaction rate (%) = heating residue - [amount of sample collected x 100/110)/amount of sample collected x 10/110 x 100 Example 3 10 parts of hydroxy methacrylate was mixed with 100 parts of EPT1045 (mentioned above), and this were thoroughly mixed in a closed pressurized kneader while cooling with water. After mixing, the temperature was raised to 120° C. while stirring, and the mixture was heated for 30 minutes to carry out an addition reaction. The conversion rate of hydroxymethacrylate in this addition reaction was 72%. Example 4 100 parts of EPT1045 (mentioned above) and a 10:90 copolymer of acrylic acid and ethyl acrylate (molecular weight 3000)
20 parts were mixed well in a closed pressurized kneader while cooling with water, and then heated at 110° C. for 60 minutes to carry out an addition reaction. The reaction rate of the above copolymer in this addition reaction was 63%. Example 5 30 parts of glycidyl methacrylate was blended with 100 parts of EPT1045 (mentioned above), and this was mixed for 30 minutes while cooling with water in a closed pressurized kneader.
The addition reaction was carried out at 100-120°C for 60 minutes. The reaction rate of glycidyl methacrylate in this addition reaction was 90%. Comparative Example 1 10 parts of maleic anhydride was mixed with 100 parts of EPT1045 (mentioned above), and this was mixed with water cooling in a pressure kneader.
Mixed for 10 minutes. Thereafter, it was taken out and heated in a hot air constant temperature bath at 100°C for 1 hour to carry out an addition reaction. The conversion rate of maleic anhydride in this addition reaction is 55%
It was hot. The reaction rate was determined by swelling a portion of the addition reaction product with toluene, extracting unreacted maleic acid with hot water, drying at 100°C for 3 hours, and measuring the heating residue, and the following measurements were performed according to Example 2. did. Comparative Example 2 100 parts of EPT1045 (mentioned above) was blended with 10 parts of maleic anhydride and 0.2 parts of benzoyl peroxide, and after mixing well with water cooling in a pressure kneader,
The addition reaction was carried out by heating at 80-100°C for 2 hours. The conversion rate of maleic anhydride in this addition reaction was measured in the same manner as in Comparative Example 1, and the result was 85%. Comparative example 3 100 parts of EPT1045 (mentioned above) and 10 parts of acrylonitrile
1 part and 0.3 part of benzoyl peroxide, and an addition reaction was carried out in the same manner as in Comparative Example 2. The conversion rate of acrylonitrile in this addition reaction was measured in the same manner as in Example 1 and was found to be 80%. The modified polymers obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were tested for adhesion, oil resistance, heat resistance, and weather resistance using the following methods. The results are shown in the table below. In addition, in the same table, the untreated sample is shown as Comparative Example 4. (1) Adhesion test The modified polymer was hot-pressed onto an EPT vulcanized rubber sheet to a thickness of approximately 0.5 mm, and then hot-pressed onto an aluminum plate so that the polymer surface was in contact with the aluminum plate. Glue. Heat and pressure conditions are 80
℃ x 10 minutes, and the crimped product in this way is 25mm
It was cut into widths and peeled off at 180 degrees at a speed of 300 mm/min to measure the adhesive strength. (2) Oil resistance test After the modified polymer was made into a sheet with a thickness of approximately 1 mm, this was cut into lengths of 50 mm both vertically and horizontally, and immersed in machine oil No. 1 at 20°C for 24 hours. The oil on the rear surface was wiped off and the weight change was measured. (3) Heat resistance test According to JISK-6001, a test piece (dumbbell No. 1, thickness 2 mm) obtained from the modified polymer was
The elongation was measured after being left at ℃ for 30 days, and the rate of change (%) with respect to the same elongation before being left was calculated.
In the table, + means an increase in elongation, and - means a decrease in elongation. (4) Weather resistance test In accordance with JISK-6001, a test piece (dumbbell No. 1, thickness 2 mm) obtained from the modified polymer was exposed for 2000 hours using a sunshine weather meter, and then the elongation was measured. The rate of change (%) with respect to the same elongation before exposure was calculated. In the table, + means an increase in elongation, and - means a decrease in elongation.

[Table] As is clear from the above table, according to the method of this invention, a specific reactive unsaturated compound can be added to an olefin interpolymer by simply heating without the aid of a radical initiator. It can be seen that the modified polymer obtained has significantly improved adhesion and oil resistance, as well as further improved heat resistance and weather resistance. On the other hand, in the case of using a reactive unsaturated compound different from that according to the present invention (Comparative Example 1), no remarkable improvement in oil resistance or adhesion was observed; In the case of using a compound and subjecting it to an addition reaction with peroxide (Comparative Example 2), the above-mentioned improvements in oil resistance and adhesion were observed, but on the other hand, the effect of improving heat resistance and weather resistance was very poor. It becomes a thing. In addition, even when using the specific reactive unsaturated compound of this invention, when it was subjected to an addition reaction with a peroxide (Comparative Example 3), oil resistance and adhesion were improved as in the case of Comparative Example 2. Even if good results are obtained in terms of properties, the effect of improving heat resistance and weather resistance will hardly be recognized.

Claims (1)

[Scope of Claims] 1. An olefin interpolymer consisting of ethylene, α-olefin and a cyclic or non-cyclic polyene having a non-conjugated double bond, at least one selected from a hydroxyl group, a carboxyl group, a nitrile group and an epoxy group. A method for modifying an olefin interpolymer, which comprises mixing a reactive unsaturated compound with a molecular weight of 10,000 or less and carrying out an addition reaction by heating in the absence of a radical initiator. 2. The method for modifying an olefin interpolymer according to claim 1, wherein the reactive unsaturated compound has a molecular weight of 1000 or less.