JPH0356549A - Chlorosulfonated polyethylene composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having clear colored tone and able to be clearly colored with a slight deterioration of electric insulating properties after dipped with water by mixing basic lead compound. CONSTITUTION:(A) 100 pts.wt. chlorosulfonated polyethylene is mixed with (B) 10-80 pts.wt. basic lead compound. Furthermore, a small amount of lead oxide or magnesium oxide may be added. As the B component, a mixture containing tribasic lead sulfate such as mixed crystal of tribasic lead sulfate with basic organic acid salt of lead as essential ingredients is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a crosslinked resin composition made of chlorosulfonated polyethylene, which has both good electrical insulation properties and a clear color tone.

[Conventional technology]

Chlorosulfonated polyethylene (hereinafter abbreviated as CS polyethylene) has excellent heat resistance, jib resistance, ozone resistance, etc., and is used as insulation materials for electric wires, cables, electronic components, rubber belts, packing, sheets, and anti-vibration materials. It is widely used for materials such as wood.

Conventionally, crosslinking (vulcanization) of this CS polyethylene has been carried out using lead oxide (PbO, Resurge) and a sulfur-containing compound vulcanization accelerator, or magnesium oxide (MgO, magnesia) and sulfur-containing compound vulcanization. A method using an accelerator is also used.

[Problem to be solved by the invention]

However, vulcanization using a combination of lead oxide and a sulfur-based vulcanization accelerator has the drawback that the color tone of the vulcanized composition lacks sharpness and vivid coloring cannot be achieved.

In addition, in vulcanization using a combination of magnesium oxide and a sulfur-based vulcanization accelerator, the water resistance of the vulcanized composition may decrease,
In particular, there is a drawback that the insulation resistance value decreases significantly after being submerged in water.

[Means to solve the problem]

In this invention, a basic lead compound is used as a vulcanizing agent, and 10 to 8 parts by weight of this is used per 100 parts by weight of CS-modified polyethylene.
The above drawbacks were solved by adding 0 parts by weight and vulcanizing.

This invention will be explained in detail below.

The CS polyethylene composition of the present invention is made by adding 10 to 80 parts by weight of a basic lead compound to 100 parts by weight of CS polyethylene.

CS-modified polyethylene is made by directly treating polyethylene such as high-density polyethylene or low-density polyethylene with chlorine and sulfur dioxide, and introducing a chlorsulfone group (-SO.C0) into the polyethylene molecule. For example, "Hypalon" (USA) , DuPont product name), etc. are used.

In addition, basic lead compounds used as vulcanizing agents include tribasic lead sulfate, dibasic lead phthalate, basic lead maleate, mixed crystals and mixtures thereof, and basic lead carbonate (lead white).
There are some lead compounds that are white in color and have a rich function as an acid acceptor that captures the chlorine that is produced as a by-product during the vulcanization of CS polyethylene. Among these, mixtures containing tribasic lead sulfate as an essential component, such as a mixed crystal of tribasic lead sulfate and basic organic acid lead, are preferred.

The blending amount of this basic lead compound is 1
The amount is 10 to 80 parts by weight relative to 00 parts by weight. If the amount of the basic lead compound is less than 10 parts by weight, vulcanization will not take place, and if it exceeds 80 parts by weight, it will not only be excessive and uneconomical, but also deteriorate mechanical properties, electrical insulation, etc. come.

The main point of this invention is to vulcanize CS-modified polyethylene with a basic lead compound, but in order to increase the vulcanization rate, vulcanization rate, etc., lead oxide, magnesium oxide, etc.
Small amounts of lead stearate, magnesium stearate, etc. can be added.

However, as mentioned above, the addition of lead oxide will cause the coloring to lack clarity, and the addition of magnesium oxide will reduce water resistance, so it is desirable to keep its addition to a minimum. The amount should be 10 parts by weight or less based on too many parts of polyethylene, and the same should be true for magnesium oxide (it should be 5 parts by weight or less based on too many parts of CS-modified polyethylene).

Further, in the composition of the present invention, a vulcanization accelerator can be used in combination, and the vulcanization accelerator used here is dipentamethylene thiuram tetrasulfide (TRA
Organic sulfur-based vulcanization accelerators such as ) impart a brown color to the composition and should be avoided; small amounts of sulfur alone or non-sulfur vulcanization accelerators such as petaerythritol are preferred. The amount of this vulcanization accelerator added is C
0.1 to 0.5 to too parts by weight of S-polyethylene
Approximately parts by weight.

Furthermore, in the composition of the present invention, a softener can be added in order to impart appropriate flexibility to the composition and improve processability. As this softener, esters such as phthalate, trimellitate, and pyromellitate are used. Normally, mineral oils such as aromatic and naphthenic oils are used as softeners for elastic bodies such as rubber, but the addition of these mineral oils reduces the electrical insulation properties of the composition. cannot obtain a sufficiently high value. For this reason, here, the above-mentioned S.A., which is used as a plasticizer for vinyl chloride resin, etc. Blend the esters.

Further, among these esters, those having a molecular weight of about 450 or more and having low volatility are preferable in order to take advantage of the heat resistance originally possessed by CS-modified polyethylene. Specific examples of esters having a molecular weight of about 4.50 or more include trioctyl trimellitate (TOTM), trioctyl pyromellitate (TOPM), diisodecyl phthalate, ditridecyl phthalate, and the like. The amount of the esters to be blended is set at an upper limit of 50 parts by weight per 100 parts by weight of CS-modified polyethylene. If the ester exceeds 50 parts by weight, it will be in excess relative to the CS-modified polyethylene, and a portion of it will lose compatibility and bleed onto the surface of the molded product, causing problems. By using these esters, it is possible to prevent the electrical insulation properties of the softened (plasticized) composition from decreasing, especially the electrical insulation resistance value after immersion in water.

Furthermore, suitable amounts of inorganic fillers such as calcium carbonate, talc, silica, titanium oxide, and various coloring agents can be added to the composition of the present invention.

In such a CS-modified polyethylene composition, the color tone of the vulcanized product is clear, and there is almost no decrease in water resistance, especially in insulation resistance after immersion in water.

Hereinafter, specific examples will be shown to clarify the effects.

〔Example〕

A composition having the formulation shown in Table 1 was prepared, kneaded by a conventional method, and vulcanized and shaped into a sheet to prepare a test piece. The hardness (Situation A) of this test piece and the volume resistivity after immersing the test piece in warm water at 60° C. for 24 hours were measured. The color tone of the test piece was also evaluated. The results are also shown in Table 1.

As is clear from the results in Table 1, the composition of the present invention has good water resistance and clear color tone.

〔Effect of the invention〕

As explained above, the chlorosulfonated polyethylene composition of the present invention has chlorosulfonated polyethylene 10
Since it contains 10 to 80 parts by weight of a basic lead compound to 0 parts by weight, there is only a slight decrease in electrical insulation properties after immersion in water, and the color tone is clear, allowing for vivid coloring. It has the following effects.

Claims (1)

[Claims] A chlorosulfonated polyethylene composition comprising 10 to 80 parts by weight of a basic lead compound per 100 parts by weight of chlorosulfonated polyethylene.