JPS6126820B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polymer composition for direct crosslinking adhesion to brass, which includes an ethylene-based saturated polymer,
By adding trimercaptotriazine and epoxy resin in the crosslinking system with organic peroxide, the peroxide has good pressure heating and crosslinking adhesion with brass without impairing the organic peroxide crosslinking properties of the polymer. The present invention relates to crosslinked polymer compositions. Conventionally, methods for adhering polymers and metals, particularly brass, include (1) interposing an ebonite layer between the polymer composition and the metal (2)
Adhesives (cyclized rubber, chlorinated rubber, phenolic resin,
(3) direct adhesion of a rubber composition and metal by pressure vulcanization, and the like. As described above, there are various conventional methods for adhering polymers and metals. For example, a method of interposing an ebonite layer between a polymer composition and a metal is possible mainly for polymers that can be made into hard rubber with sulfur, but it generally takes a long time to bond and is not suitable for applications that require flexibility. It had drawbacks such as being difficult to use. In addition, the method shown in (2), in which an adhesive is applied to a metal surface and a polymer composition is pressure-crosslinked and bonded, is commonly used. Although this increases the adhesive strength, it has the disadvantage that it is insufficient to achieve strong adhesion between brass and polymer. In addition, as a direct bonding method between polymer and brass, it is known that good adhesion can be obtained between sulfur-crosslinkable rubber, such as diene rubber vulcanizate, and brass. Adhesion techniques between wires and polymers are often used. This is thought to be due to the primary bond between the rubber and copper formed by the reaction between the mercapto group and copper that occurs during the rubber vulcanization reaction, or the reaction between CuS and the double bond of the rubber. However, when attempting to apply the above direct bonding method to polymer compositions in which peroxide crosslinking is required or preferred in order to obtain properties essential to elastomers such as permanent elongation and compression set, During pressure and heat adhesion, the reaction between the peroxide and sulfur or a sulfur donor such as thiuram-based thiazole causes a primary bonding reaction between the polymer composition and the brass, and inhibition of the crosslinking reaction between the polymer and the peroxide leads to a bonding reaction between the brass and the peroxide. It has the disadvantage that both the adhesive strength and the physical properties of the crosslinked material are impaired. In addition, mixing a polar compound used in adhesives as shown in (2) into the peroxide cross-linked product to increase the secondary bonding force and strengthen the adhesive force essentially exceeds the adhesive force due to the primary bonding. It is thought that power cannot be obtained. These disadvantages can be overcome by peroxide crosslinked products, which are generally advantageous over other crosslinked systems such as highly saturated polymers such as ethylene propylene rubber (EPR, EPDM), ethylene vinyl acetate rubber (EVA), and chlorinated polyethylene (CM). This is particularly noticeable in chlorosulfonated polyethylene (CSM) and polyethylene (PE). In order to solve the above-mentioned drawbacks, the inventors have developed various adhesion systems for peroxide-crosslinked polymer formulations that have less reactivity with peroxide and therefore less deterioration of physical properties and have secondary bonding strength due to sulfur. As a result of investigating sulfur donors, it was found that an adhesive system having the desired effect could be obtained by combining a polymer with a peroxide, a trimercaptotriazine, and an epoxy compound. In these adhesive systems, it is important to note that trimercaptotriazine and the epoxy compound have reactivity, that trimercaptotriazine and the above polymers have reactivity, and that trimercaptotriazine has reactivity with copper. is also publicly known. However, in a peroxide crosslinking system, a good adhesive effect cannot be obtained by adding only trimercaptotriazine, but the present invention is characterized in that a good adhesive effect can be obtained by combining the above-mentioned epoxy compounds. This is because the reaction between peroxide and trimercaptotriazine and the polymer, the reaction between the epoxy compound and trimercaptotriazine, and the reaction between trimercaptotriazine and copper in the brass alloy proceed in concert, resulting in the secondary bonding force between the epoxy compound and the metal. Together with this, it is thought that the peroxide crosslinked product exhibits adhesive strength without deteriorating its physical properties. Therefore, any material having two mercapto groups in the triazine ring may be used to develop adhesion. An object of the present invention is to reduce the organic peroxide crosslinking properties of the polymer by the reaction of peroxide with sulfur or a sulfur donor in direct adhesion between an organic peroxide crosslinking polymer composition and brass plates or wires. It is possible to firmly bond the peroxide crosslinked polymer composition and brass plates or wires without any problems, and to provide particularly high crosslinking density, and to obtain low compression set, etc., the polymer composition and brass are bonded together. Fields that require peroxide cross-linked adhesion,
The object of the present invention is to provide a peroxide crosslinked polymer composition that can be used, for example, in belts, hoses, molds, rubber rolls, linings, metal parts of bags, and the like. The present invention provides a polymer composition containing 1 to 30 parts by weight of an organic peroxide per 100 parts by weight of an ethylene-based saturated polymer, and further comprising 0.001 to 30 parts by weight of trimercaptotriazine per 100 parts by weight of the polymer.
0.1 mol and epoxy resin per 1 mol of trimercaptotriazine, expressed as the number of epoxy groups.
It is a polymer composition with excellent adhesion to brass, which is characterized by being added at a ratio of 0.1 to 10. Ethylene-based saturated polymers that can be used in the present invention include ethylene propylene rubber (EPR,
EPDM), ethylene vinyl acetate rubber (EVA), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), polyvinyl chloride (PVC), etc., with CM, CSM, etc. being preferred. Further, the type of peroxide used in the present invention may be any peroxide as long as the crosslinking reaction does not proceed to an extreme extent at the temperature during processing in the compounding system, preferably one with a half-life of 10 hours and a decomposition temperature of 80°C or higher. Certain dialkyl peroxides are good. For example, dicumyl peroxide, 4,4-tertiarybutyl peroxyvaleric acid n
-butyl, 1,3-bis-(t-butylperoxy-isopropyl)benzene. More preferred is n-butyl 4,4-di,t-butylperoxyvalericate. In addition, the type of epoxy compound used in the present invention may be any mono- or di- or higher-functional epoxide as long as it is an epoxy resin that can react with trimercaptotriazine, and the resin structure may include glycidyl ether type, glycidyl ester type, Any of glycidylamine type, flocculent aliphatic epoxide, and alicyclic epoxide may be used. In the practice of the present invention, 1 to 30 g, preferably 2 to 20 g of peroxide is blended with 100 g of ethylene-based saturated polymer (less than 1 g will not crosslink, and more than 30 g will cause scorch, which is not practical). Furthermore, the number of epoxy groups in the added epoxy is preferably 0.1 to 10 per mole of trimercaptotriazine.
The amount of mercaptotriazine is preferably 0.001 to 0.1 mol (0.177 to 17.7 g) in a ratio of 0.2 to 5.
Add in a range of 0.007 to 0.07 mol (1.2 to 12 g). If trimercaptotriazine is less than 0.001 mol, it will not adhere, and if it exceeds 0.1 mol, it will react with peroxide and inhibit crosslinking. If there are less than 0.1 epoxy groups per mole of trimercaptotriazine, no adhesive effect due to a synergistic action with triazine will be obtained, and if there are more than 10 epoxy groups, the epoxy groups will react with triazine, resulting in no adhesion. Trimercaptotriazine and epoxy compound work together to increase the adhesive effect, but they also react with each other, so when increasing the amount of epoxy compound used,
At the same time, it is necessary to increase the amount of trimercaptotriazine. Further, if necessary, a plasticizer, a reinforcing agent, a pigment, etc. are mixed therein, and the product is processed and molded into the desired shape using a normal processing method, and is bonded to the brass by pressure heating and cross-linking. As for the pressurization and heating method, in addition to the usual press, it is of course possible to use steam, hot water, or the like. By using the polymer composition according to the present invention as an adhesive polymer, it is possible to obtain a molded product as a rubber/metal composite by interposing it between a brass plate and other compounds, and further, by dissolving the polymer composition in an organic solvent or the like. It can also be used as a so-called cement layer. It goes without saying that the polymer composition of the polymer composition may be a blend of two or more different types of peroxide crosslinkable polymers. Further, the compression heating temperature may be any temperature as long as peroxide crosslinking is possible (130°C to 180°C). Next, the present invention will be explained with reference to examples. In addition,
In each example, the amounts (parts) are based on weight unless otherwise specified. Example 1 The composition shown in Table 1 was mixed for 15 minutes at 70°C with a mixing roll, formed into a sheet approximately 2.5 mm thick, thoroughly immersed in toluene for degreasing, and then dried.
The sheet was placed on a brass plate having a thickness of mm, and pressure molded using a press molding machine at 165° C. for 30 minutes at a surface pressure of 30 kg/cm ² . Also, 2.5 mm 180° peeling force is 50 by autograph.
Measurement was performed at a peeling rate of mm/sec. A cross-linked sheet was created under the same vulcanization conditions as above and JIS-K-
Crosslinked physical properties were measured using 6301. Comparing Blend Nos. 1 and 2 in Table 1, it can be seen that in the epoxy resin/trimercaptotriazine/peroxide system, trimercaptotriazine contributes to improving adhesion and the crosslinking properties do not deteriorate. Comparing Blends No. 2 and No. 5, it can be seen that in the peroxide cross-linked system, the addition of sulfur causes a greater drop in physical properties compared to trimercaptotriazine, and it is not possible to impart adhesive strength. In addition, a comparison of formulations Nos. 1 and 3 reveals that epoxy resin alone does not improve the adhesion to the brass plate. It is also seen from formulation No. 4 that in the epoxy/mercaptotriazine/peroxide system, removing epoxy reduces the adhesive strength. Also No.
A comparison of Examples 2 and 7 shows that similar results can be obtained even if the type of peroxide crosslinkable polymer is changed.

【table】

[Table] Example 2 (Relationship between the amount of 1,3,5-trimercaptotriazine added and adhesion)

【table】

[Table] Example 2 shows the relationship between 1,3,5-trimercaptotriazine and brass adhesion in the epoxy resin/1,3,5-trimercaptotriazine/peroxide adhesive system. The random effects of triazine are shown in Table 2. Method for preparing compositions of formulation Nos. 8 to 12 in this example,
The sample preparation method and adhesive force measurement method were the same as in Example 1. The test results for formulations Nos. 8 to 12 show that the addition of 1,3,5-trimercaptotriazine in this adhesive system has an effective effect on the adhesive strength with brass. Example 3 (Effect of the amount of epoxy resin added)

【table】

[Table] In Example 3, in the peroxide vulcanization system,
Addition amount of epoxy resin (Epicote 828) and 1,
The variation in adhesion strength with brass when the amount of 3,5-trimercaptotriazine added was varied in the third experiment.
- Shown in Table 4. This result shows that as the amount of epoxy resin added increases, the amount of 1,3,5-trimercaptotriazine required to provide effective adhesive strength also increases. It can be seen that there is a correlation between the amount of resin and the amount of 1,3,5-trimercaptotriazine. Furthermore, since no adhesive force was developed in the system without the addition of epoxy resin, it can be seen that the present adhesive system is composed of a system of peroxide/1,3,5-mercaptotriazine/epoxy resin. Example 4 (Effect of type of epoxy resin)

【table】

[Table] Table 5 and Figure 1 show the relationship between the type of epoxy resin and the amount of 1,3,5-trimercaptotriazine that provides the optimum amount of adhesion. (The blending amount of the peroxide adhesive system is the same as in Table 3.) Types of epoxy resins include Epicote 828, 834, and 871 with different epoxy equivalents and structures, and TEPIC as a monofunctional epoxy and phenyl glycidyl ether trifunctional epoxy. was selected. Provides optimal adhesion in peroxide/epoxy/1,3,5-trimercaptotriazine systems. The relationship between the number of epoxy groups contained in the epoxy resin added to 100 g of rubber and the amount of 1,3,5-trimercaptotriazine that provides optimal adhesion is shown in Figure 1. It can be seen that there is a correlation between the two. Figure 1 shows the epoxy and 1,3,5-trimercaptotriazine required to provide optimal adhesiveness, but based on this correlation, even within the range shown, adhesiveness is developed as shown in Examples 1, 2, and 3. Needless to say, the amount should be determined depending on the purpose and use. However, it goes without saying that adhesive properties will not be developed if it deviates significantly from this range. From the above results, it is easy to believe that in the epoxy/1,3,5-trimercaptotriazine/peroxide system, there is an optimal range for adhesion due to mutual reactions with the additive system and with the polymer. It is thought that this adhesive system constitutes a reaction system suitable for adhesion between a polymer and brass without impairing the physical properties of the peroxide crosslinked polymer. As is clear from the above results, a composition in which epoxy and mercaptotriazine are used in combination in a polymer composition using peroxide as a crosslinking system,
Good crosslinking properties and crosslinking adhesion to brass can be imparted without deterioration of physical properties due to the reaction between peroxide and sulfur, and without deterioration of adhesive strength with brass. Therefore, by using the present composition, a polymer system that can obtain the most desirable physical properties such as high elasticity and high compression set resistance through peroxide crosslinking, and a brass plate or wire or a brass plated plate or wire is used. When trying to manufacture composites of polymers, it has the advantage that it can be used as a composition for direct adhesion between polymers and brass, and it can also be used as an adhesive rubber layer or as an adhesive dissolved in a solvent to bond other polymer compounds and brass. It can also be used for adhesion.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the number of epoxy groups and the amount of trimercaptotriazine to obtain the highest adhesive strength when using the composition of the present invention.

Claims (1)

[Claims] 1. In a polymer composition containing 1 to 30 parts by weight of an organic peroxide to 100 parts by weight of an ethylene-based saturated polymer, 0.001 to 0.1 mol of trimercaptotriazine is further added to 100 parts by weight of the polymer and an epoxy resin is added to trimercaptotriazine. 1
A polymer composition with excellent adhesion to brass, characterized in that it is added at a ratio of 0.1 to 10 in terms of the number of epoxy groups per mole.