JP2817231B2 - Chlorosulfonated polyethylene polymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composition for vulcanizing a chlorosulfonated polyethylene polymer. More particularly, it relates to a chlorosulfonated polyethylene polymer composition having improved flex crack resistance.

The composition is particularly useful for belts such as timing belts, V-belts, polyribbed belts, and boots such as constant velocity joint boots, ball joint boots, and rack and pinion boots.

[Prior art] Chlorosulfonated polyethylene polymer has ozone resistance,
It is a special elastomer with excellent weather resistance, heat resistance, oil resistance, and chemical resistance.It is used for extruded products such as electric wires and hoses, calendar products such as drawn cloth, paints, adhesives, etc. ing.

However, special rubber applications such as belts and boots are also used in so-called dynamic environments where the amount of deformation and distortion is large and the deformation speed is high. Even if it occurs, crack growth is slow, and a long time to fracture is required.

In this respect, chlorosulfonated polyethylene polymers have not been considered to have sufficient performance so far, and improvement in flex crack resistance has been desired so that they can be used in a dynamic environment.

[Problems to be Solved by the Invention] That is, an object of the present invention is to provide a large deformation distortion amount of a belt, a boot and the like, and a high repetition deformation speed.
Chlorosulfonation that not only has excellent mechanical properties as a rubber that has excellent strength, heat resistance and cold resistance in a so-called dynamic environment but also has excellent crack resistance An object of the present invention is to provide a polyethylene polymer composition.

[Means for Solving the Problems] The present inventors have conducted intensive studies to obtain a vulcanizate having excellent crack resistance, and as a result, have found that the following chlorosulfonated polyethylene polymer composition achieves the object.

That is, the present invention provides: a) 100 parts by weight of a chlorosulfonated polyethylene polymer having a sulfur content of 0.2 to 1.2 wt% and a chlorine content of 20 to 50 wt%, and b) an alkylnaphthalene condensate having an alkyl chain having 2 or more carbon atoms. 1-30 parts by weight c) Acid acceptor 1-30 parts by weight d) Chlorosulfonated polyethylene polymer composition comprising 0.1-10 parts by weight of diamine maleimide and / or thiurams.

However, the symbol “−” is written as “A” to “B” to indicate that the value is A or more and B or less.

[Action] In the present invention, the sulfur content is 0.2 to 1.2 wt%, and the chlorine content is 20 to 50 wt%.
The chlorosulfonated polyethylene polymer is chlorine and sulfur dioxide gas, chlorine and sulfuryl chloride or sulfuryl chloride alone or chlorinated and chlorinated so that the polyethylene polymer contains a predetermined amount of sulfur (ie, -SO ₂ Cl) and an amount of chlorine. It is obtained by sulfonation.

Examples of the polymer as a raw material include polyethylene, ethylene-butene-1 copolymer, ethylene-propylene copolymer, and ethylene-based copolymer such as ethylene-vinyl acetate copolymer.

In the present invention, it is important that the sulfur content of the chlorosulfonated polyethylene polymer is 0.2 to 1.2% by weight.

If the content is less than 0.2 wt%, the crosslinked density of the vulcanized product becomes low and the tensile strength is inferior, so that it cannot be put to practical use. On the other hand, if the sulfur content exceeds 1.2 wt%, the crosslinked density of the vulcanizate is sufficient, but the crack resistance is poor.

 More preferably, the sulfur content is 0.4 to 0.8 wt%.

In the present invention, the amount of chlorine in the chlorosulfonated polyethylene polymer is not particularly limited, and may be 20 to 50% by weight. However, when the chlorosulfonated polyethylene polymer composition of the present invention is used in a low-temperature atmosphere and cold resistance is desired, the chlorine content is desirably in the range of 20 to 32% by weight.

The alkylnaphthalene condensate having 2 or more carbon atoms in the alkyl chain referred to in the present invention is a methylene condensate of a mono- or polyalkylnaphthalene having 2 or more carbon atoms in the alkyl chain, and is an ethylnaphthalene condensate, n-propyl Naphthalene condensate, isopropyl naphthalene condensate, butyl naphthalene condensate, isobutyl naphthalene condensate, diethyl naphthalene condensate, di-n-propyl naphthalene condensate,
Examples thereof include a diisopropyl naphthalene condensate, a dibutyl naphthalene condensate, and a diisobutyl naphthalene condensate, and there is no particular limitation on the substitution position of the naphthalene ring.

An alkylnaphthalene condensate having an alkyl chain having 1 carbon atom has insufficient crack resistance, and is preferably a dialkylnaphthalene condensate having an alkyl chain having 2 or more carbon atoms.

 There is no particular limitation on the degree of condensation.

In the present invention, the alkylnaphthalene condensate having an alkyl chain having 2 or more carbon atoms is used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the chlorosulfonated polyethylene polymer. If the amount is less than 1 part by weight, crack resistance is not sufficient, and if it is more than 30 parts by weight, low-temperature brittleness deteriorates. Preferably, it is 2 to 15 parts by weight.

Examples of the acid acceptor include alkaline earth metal oxides and hydroxides, and specific preferred examples thereof include magnesium oxide, calcium oxide, calcium hydroxide, and lead oxide. Hydrotalcite, which is a composite of a metal hydroxide and a carbonate, can also be used. The compounding amount is 1 to 30 parts by weight based on 100 parts by weight of the chlorosulfonated polyethylene polymer. If the amount is less than 1 part by weight, the effect of receiving acid is not sufficient, and if it is more than 30 parts by weight, only a vulcanized product having high hardness can be obtained.

Specific examples of the diamine maleimide compound used in the present invention include N, N'-phenylenediamine maleimide,
N, N'-ethylenediaminemaleimide, N, N'-propylenediaminemaleimide and the like are used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the chlorosulfonated polyethylene polymer.

N, N'-diphenylethylenediamine, N-isopropyl N'-phenyl-p-phenylenediamine, a condensate of n-butyraldehyde and aniline, 6-ethoxy-2,
When used in combination with an amine compound such as 2,4-trimethyl-1,2-dihydroquinoline and / or nickel dialkyldithiocarbamate such as nickel diethyldithiocarbamate and nickel dibutyldithiocarbamate, the diaminemaleimide compound acts as a vulcanizing agent. If the amount is less than 0.1 part by weight, the crosslinking density is low and the tensile strength is reduced. If the amount is more than 10 parts by weight, the scorch becomes short and a problem occurs in the processing step.

Further, when the diamine maleimide compound is used not in combination with the amine compound and / or nickel dialkyldithiocarbamate but in combination with thiurams, the compound functions as a vulcanizing aid for increasing scorch safety, and the thiurams function as a vulcanizing agent. When the amount of the diamine maleimide compound is 0.1 parts by weight or less, the scorch time does not increase. When the amount is 10 parts by weight or more, vulcanization is delayed, and a sufficient tensile strength cannot be obtained. The preferred amount is 1 to 5 parts by weight.

Specific examples of thiurams include dipentamethylenethiuram tetrasulfide (TRA), tetramethylthiuram disulfide (TMTD), and tetraethylthiuram disulfide (TETD). The compounding amount is 0.1 to 10 parts by weight based on 100 parts by weight of the chlorosulfonated polyethylene polymer.

If the amount of thiurams is less than 0.1 part by weight, the crosslinking density is low and the tensile strength is reduced. If the amount is more than 10 parts by weight, crack resistance is poor. The preferred amount is 0.5 to 5 parts by weight.

Diamine maleimide compounds and thiurams can be used alone, but when used together, processing safety,
This is advantageous in balancing the crosslink density, and is more preferable.

In addition to the composition of the present invention, fillers such as carbon black, clay, silica, calcium carbonate and oil as plasticizers, esters, chlorinated paraffins and low molecular weight polyethylene as processing aids and antioxidants, etc. And
Conventional rubber compounding agents can be added as needed.

Vulcanization is carried out by a known method such as steam vulcanization or press vulcanization, usually at 140 to 250 ° C. for 1 to 100 minutes.

[Examples] Next, in order to specifically describe the present invention, examples and comparative examples will be described. However, these are examples for helping to understand the present invention, and the present invention is not limited thereto. Not something.

The numerical values described in Examples and Comparative Examples were obtained by the following measurement methods.

Mooney scorch: JIS K6300 Tensile properties: JIS K6301 Flex crack resistance: Dematcher crack growth test was performed at 23 ° C. in accordance with JIS K6301, and the number of flexures until the crack length reached 10 mm was determined.

Gehman cold resistance test: JIS K6301 Examples 1-4 In a 10 liter reactor, 10 kg of carbon tetrachloride and a melt flow rate of 2 g / 10 min, a density of 0.92, per 1000 carbon atoms copolymerized with butene-1 1.0 kg of linear low-density polyethylene having 23 methyl groups was added, and the polyethylene was dissolved at 110 ° C. under pressure. After 0.12 g of pyridine was added as a cocatalyst by a conventional method, 1820 g of sulfuryl chloride was added while 800 g of carbon tetrachloride in which 2.0 g of α, α'-azobisisobutyronitrile was dissolved as a radical generator. After the reaction is completed, carbon tetrachloride is removed by a drum dryer, and solid chlorosulfonated polyethylene polymer (chlorine content 30 wt%, sulfur content 0.7 wt%, Mooney viscosity 81)
I got

Using this chlorosulfonated polyethylene polymer, a diethylnaphthalene condensate (manufactured by Silund Seiracher Co., trade name: Stractol 40MS-F) as an alkylnaphthalene condensate having an alkyl chain having 2 or more carbon atoms,
N, N'-phenylenediamine maleimide (Ouchi Shinko, trade name: Balnoc PM) as a vulcanizing agent, dipentamethylenethiuram tetrasulfide (Ouchi Shinko, trade name Noxeller TR, a thiuram)
A), and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (manufactured by Ouchi Shinko, trade name Nocrack AW-
Along with N), a composition was prepared according to the composition shown in Table 1 by Banbury kneading and press vulcanized at 150 ° C. for 20 minutes to prepare a vulcanized sheet.

Comparative Examples 1-2 The same chlorosulfonated polyethylene polymer as in Examples 1-4 was used.

In Comparative Example 1, an alkyl naphthalene condensate having an alkyl chain having 2 or more carbon atoms was not added, and in Comparative Example 2, a dimethyl naphthalene condensate which was an alkyl naphthalene condensate having an alkyl chain of 1 (manufactured by Kenrich Co., Ltd.) With trade name Kenflex A)
A composition was prepared with the composition shown in No. 1 and press-vulcanized at 150 ° C. for 20 minutes to prepare a vulcanized sheet.

As is clear from the results in Table 1, the vulcanized products of the blends of Examples 1 to 4 in which the diethyl naphthalene condensate was blended were Comparative Example 1 in which the diethyl naphthalene condensate was not contained, and the carbon number of the alkyl chain was 1 It can be seen that the composition exhibits superior flex crack resistance as compared with Comparative Example 2 in which the dialkylnaphthalene condensate was added.

Comparative Example 3 A chlorosulfonated polyethylene polymer (chlorine content) synthesized using the same starting polyethylene as in Examples 1 to 4
The procedure was performed in the same manner as in Examples 1 to 4, except that 30 wt%, the amount of sulfur was 1.5 wt%, and the Mooney viscosity was 102). The results are shown in Table 1.

It can be seen that when the sulfur content is set to 1.5 wt%, even if a diethylalkylnaphthalene condensate is contained, the crack resistance is inferior to Examples 1-4.

Examples 5 to 6 Chlorosulfonated polyethylene polymers (chlorine content 26) synthesized using the same linear low-density polyethylene as in Examples 1 to 4 except that the melt flow rate was 6 g / 10 min as a raw material.
wt%, sulfur content 1.0 wt%, Mooney viscosity 45) were used.

In Example 5, no cracks PM and nickel dibutyldithiocarbamate (Ouchi Shinko, trade name: Nocrack NBC) were used without using thiurams as a vulcanizing agent, and in Example 6, diamine maleimide was not used as a vulcanizing agent. Using Noxeller TRA and Pentaerythritol. The procedure was performed in the same manner as in Examples 1 to 4, except that the amounts of magnesium oxide, FEF carbon, and plasticizer DOS were reduced.

 Table 1 shows the results of Examples 5 and 6.

Example 7 A chlorosulfonated polyethylene polymer having a chlorine content of 26 wt%, a sulfur content of 0.5 wt%, and a Mooney viscosity of 43, produced from the same raw material polyethylene as in Examples 5 to 6, was used as a vulcanizing agent. And pentaerythritol. Other than that, it carried out similarly to Example 5-6. Table 1 shows the results of Example 7.

It is clear that all of Examples 5 to 7 show excellent crack resistance.

Example 8 TOSO-CSM, a chlorosulfonated polyethylene polymer having a high chlorine content; TS430 (35 wt% chlorine content, 1.0 wt% sulfur content)
%, Mooney viscosity 45, manufactured by Tosoh Corporation). The results are shown in Table 1.

It can be seen that, although inferior in cold resistance, it exhibits excellent flex crack resistance as in the other examples.

[Effect of the Invention] The chlorosulfonated polyethylene polymer composition according to the present invention has excellent ozone resistance, weather resistance, heat resistance, oil resistance, and chemical resistance inherent to the chlorosulfonated polyethylene polymer, A chlorosulfonated polyethylene polymer vulcanizate having excellent mechanical properties and cold resistance and having improved crack resistance, which has been a disadvantage of the prior art, is provided.

For this reason, it is useful for applications that are used in so-called dynamic environments where the amount of deformation distortion is large and the deformation rate is high, which has been rarely applied in the past, especially in rack and pinion boots, ball joint boots, and constant velocity. It is suitable for boots such as joint boots and belts such as timing belts, polyribbed belts and V-belts.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 61:18) (C08K 13/02 3:22 5: 3415 5:40) (58) Investigated field (Int.Cl. ⁶ , DB name) C08L 23/34

Claims (1)

(57) [Claims] 1. A) Sulfur content 0.2 to 1.2 wt%, chlorine content 20 to 50
(b) 1 to 30 parts by weight of an alkylnaphthalene condensate having 2 or more carbon atoms in the alkyl chain per 100 parts by weight of a chlorosulfonated polyethylene polymer (wt%) c) 1 to 30 parts by weight of an acid acceptor d) Diamine maleimide And / or 0.1 to 10 parts by weight of thiurams.