JPS6234243B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for crosslinking chlorinated polyethylene. As a method for crosslinking chlorinated polyethylene, a method using an organic peroxide is conventionally known. However, this conventionally widely practiced method requires high temperatures of 100°C or more for crosslinking.
The required cross-pole cannot be obtained at normal temperature and pressure. For example, in the vulcanization method using Deikmil peroxide, which is commonly used as an organic peroxide, even if an excellent vulcanization accelerator is used, press vulcanization requires heating at 150℃ for 30 to 60 minutes. be. In the case of steam vulcanization, a continuous vulcanizer is used,
The extruded product is introduced into a vulcanization tube and heated with high-temperature, high-pressure steam to perform vulcanization. Alternatively, the material is extruded, covered with tape or lead, placed in a vulcanization pot, and vulcanized by directly introducing high-temperature, high-pressure steam. As described above, conventional vulcanization methods require heating in any case, and therefore have the disadvantage that a large amount of thermal energy, such as electric heating, high temperature, and high pressure steam, is consumed. Furthermore, these conventional vulcanization methods require special manufacturing equipment such as a hot press, a continuous vulcanizer, and a vulcanizing pot, resulting in high equipment costs. The present invention has been made to overcome these conventional drawbacks, and its particular purpose is to provide a method that can crosslink chlorinated polyethylene at room temperature and under normal pressure. A feature of the present invention that achieves this object is to react an amino group-containing aminoorganosilane compound with chlorinated polyethylene to produce a crosslinkable chlorinated polyethylene, a so-called chlorinated polyethylene silane graftomer. A method for crosslinking chlorinated polyethylene by contacting it with moisture in the presence of a silanol condensation catalyst. The aminoorganosilane compound has the general formula RR′ _o SiX _3-o (wherein R is an organic group bonded to silicon via a silicon-to-carbon bond and has 20 or less carbon atoms; The group is composed of carbon, hydrogen, nitrogen and optionally oxygen and contains at least one amino group, R' being 1 having 1 to 9 carbon atoms.
is a valent hydrocarbon group, X is an alkoxy group having 1 to 6 carbon atoms, or an alkoxyalkoxy group or an oxime group having up to 14 carbon atoms, and n is 0 or 1); More specifically, as mentioned above, R is an organic group containing at least one amino group. The amino group includes primary, secondary and tertiary amino, and also includes imino. Therefore, as an example of an R group,
−(CH ₂ ) ₃ NHCH ₂ CH ₂ NH ₂ , −
(CH ₂ ) ₄ NHCH ₂ CH ₂ NH ₂ , −
(CH ₂ ) ₃ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NH ₂ , −
CH ₂ CHCH ₃ CH ₂ NH(CH ₂ ) ₆ NH ₂ , −(CH ₂ ) ₃ NH ₂ ,
−(CH ₂ ) ₄ NHCH ₃ , −(CH ₂ ) ₁₁ NH ₂ , −NHSi
(CH ₃ ) ₃ , −(CH ₂ ) ₃ NHCH ₂ CH ₂ NHCO・NH ₂ , and

Examples include [Formula]. Among these, R is of the formula -QNH ₂ or -
QNHCH ₂ CH ₂ NH ₂ (wherein, Q is -(CH ₂ ) ₃ -, -
( _CH2 ) _4- or _-CH2CHCH3- ) _is preferred. R' is a monovalent hydrocarbon radical having 1 to 9 carbon atoms. Each X substituent may also be an alkoxy or alkoxyalkoxy group having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy or methoxyethoxy, or an oxime group having up to 14 carbon atoms, such as -ON=C(CH ₃ )
( _{C2H5 )} , or -ON=C( _CH3 )( _{C6H5 )} . Preferred aminoorganosilane compounds for use in the present invention are those in which X is an alkoxy group having 1 to 4 carbon atoms, e.g.
H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ , CH ₃・NH・C ₃ H ₆ Si
(OC ₂ H ₅ ) ₃ , H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si(OCH ₃ ) ₃ and the like are preferred. Next, crosslinking of chlorinated polyethylene in the present invention will be described. First, chlorinated polyethylene and an aminoorganosilane compound are reacted to produce a crosslinkable chlorinated polyethylene silane graftomer. This reaction is thought to be based on the following reaction formula. (However, aminoorganosilane compounds are expressed as H ₂ NRR′ _o Si(OR″) _3-o .) A specific method for obtaining such a silane graftomer of chlorinated polyethylene is to sufficiently mix chlorinated polyethylene and an aminoorganosilane compound at 100°C or lower, preferably at 40°C to 80°C. This can be carried out using, for example, a two-roll kneader, a Banbury mixer, a kneader, an extruder, or the like. The amount of the aminoorganosilane compound used at this time is 0.1 to 20 parts by weight, preferably 1 part by weight, based on 100 parts by weight of chlorinated polyethylene.
~10 parts by weight. The silane-grafted chlorinated polyethylene thus obtained can be shaped by conventional extrusion or other methods and then crosslinked by contacting with water in the presence of a silanol condensation catalyst. In this case, crosslinking can occur even with moisture present in the atmosphere. Alternatively, a compound that releases moisture may be directly mixed with a chlorinated polyethylene silane graftomer and then molded. Compounds that release water include anhydrous inorganic salts that have a high absorption rate and amount of water at room temperature, contain water in the polymer as water of crystallization, and release water of crystallization when decomposed by the heat during extrusion processing, such as sulfuric acid. Examples include sodium, sodium sulfite, magnesium sulfate, thallium sulfate, and strontium chloride. As the silanol condensation catalyst, a substance that promotes the formation of siloxane bonds in the presence of moisture can be used. The crosslinking of the chlorinated polyethylene graftomer with water in the presence of this silanol condensation catalyst is considered to be according to the following reaction formula. Various substances are already known that are effective as silanol condensation catalysts, including metal salts of carboxylic acids, titanium chelates, alkyl titanate esters, and organic acids. Examples include dibutyltin dilaurate, dibutyltin dioctoate, lead octoate, cobalt octoate, tetrabutyl titanate, P-toluenesulfonic acid, acetic acid, and the like.
Among these, preferred catalysts are organometallic compounds, and more specifically tin carboxylates, such as the above-mentioned dibutyltin dilaurate and dibutyltin diacetate. The blending of the silanol condensation catalyst may vary from 0.01 to 10 parts by weight based on 100 parts by weight of the chlorinated polyethylene graftomer. However, it is preferably 0.01 to 1 part by weight. This silanol condensation catalyst is preferably blended into the chlorinated polyethylene graftomer immediately before processing and molding. For example, a catalyst master patch in which a silanol condensation catalyst is blended with untreated chlorinated polyethylene is made in advance, and when processing and molding it,
It can be mixed with chlorinated polyethylene graftomer. Alternatively, a silanol condensation catalyst may be dispersed in a processed and molded chlorinated polyethylene graftomer and the resulting product may be brought into contact with an aqueous solution. If necessary, fillers, pigments, anti-aging agents, processing aids, etc. can be added to the chlorinated polyethylene graftomer produced according to the present invention before or after making the graftomer. As described above, the crosslinked chlorinated polyethylene produced according to the present invention can be used without any problem in areas where conventionally crosslinked chlorinated polyethylene is used. For example, it can be used for covering materials for electric wires and cables, sealing materials, pipes, etc. Examples of the present invention will be described below, but of course the present invention is not limited thereto. <Example> Formulation A (graftomer) Chlorinated polyethylene (Elastrene 401A)
100 parts by weight Silane A1100, H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ (manufactured by Nippon Unicar) 2 SPF carbon 3 Hard clay 60 DOP 15 Roll kneading the above mixture at approximately 60℃ I made a graftomer. Blend B (Catalyst Conc) Chlorinated polyethylene (Elastrene 401A)
100 parts by weight dibutyltin dilaurate 1 The above formulation was roll kneaded at about 60°C to prepare a catalyst concrete. Graftomer of formulation A prepared in this way
A mixture of 100 parts by weight and 5 parts by weight of catalyst concretion B was fed into an extruder and coated onto a 5.5 mm ² conductor. The extruded product was immersed in water at room temperature for one day, and the properties of the coating layer were measured, and the following results were obtained. 200% Modulus 0.6Kg/mm ² Tensile Strength 1.7Kg/mm ² Elongation 450% Heating Deformation Rate 27% Permanent Deformation Rate 5% <Comparative Example> Blend C Chlorinated Polyethylene (Elastrene 401A)
100 parts by weight Tribasic lead sulfate 5 Deicmil peroxide 2.5 Triallyl isocyanate 2 SRF carbon 3 DOP 15 For comparison with the present invention, the above formulation C was heated at about 60°C according to the conventional method. After kneading with rolls, the mixture was fed to an extruder and coated onto a conductor. A cloth tape was wrapped on top of this coating layer, and the mixture was placed in a vulcanization pot at 150°C and heated for about 15 minutes to vulcanize it. When the properties of the coating layer thus vulcanized were measured, the following crystals were obtained. 200% Modulus 0.6Kg/ ^mm2 Tensile strength 1.8Kg/ ^mm2 Elongation 460% Heating deformation rate 25% Permanent deformation rate 6% From the results of the above examples and comparative examples, it is clear that cross-linked chlorinated polyethylene due to moisture in the present invention and the characteristics of
It can be seen that the properties of those crosslinked by heating using the conventional method are almost the same. As described above, according to the present invention, chlorinated polyethylene can be crosslinked without applying heat and pressure. Therefore, a large amount of thermal energy such as electric heat, high temperature, and high pressure steam for heating is not required, and manufacturing costs can be reduced. In addition, special manufacturing equipment such as heated presses, continuous vulcanizers, and vulcanizing pots is no longer required, which reduces equipment costs and eliminates the need for heat management, which significantly simplifies equipment maintenance. be.

Claims (1)

[Claims] 1 Chlorinated polyethylene and general formula RR′ _n SiX _3-o
(However, in the formula, R is an organic group bonded to silicon through a silicon-to-carbon bond and having 20 or less carbon atoms, and the R group is composed of carbon, hydrogen, nitrogen, and optionally oxygen, and at least 1 containing one amino group and R' having 1 to 9 carbon atoms
a valent hydrocarbon group, X is an alkoxy group having 1 to 6 carbon atoms, or an alkoxyalkoxy group or an oxime group having up to 14 carbon atoms, and n is 0 or 1) A method for crosslinking chlorinated polyethylene, which comprises reacting an organic silane compound to obtain crosslinkable chlorinated polyethylene, and contacting this with moisture in the presence of a silanol condensation catalyst.