JPS6116945A - Electrically-conductive composition - Google Patents

Abstract

PURPOSE:An electrically-conductive composition useful as parts of electrical tools, etc., having improved electrical conductivity, improved mechanical properties and molding properties, comprising a non-crystalline chlorinated polyethylene, a crystalline chlorinated polyethylene, and two kinds of electrically-conductive carbon black, etc. CONSTITUTION:(A) 100pts.wt. two kinds of chlorinated polyethylenes consisting of A1: 100pts.wt. non-crystalline chlorinated polyethylene having 20-50wt% chlorine content, and A2: 50-120pts.wt. crystalline chlorinated polyethylene having 20-50wt% chlorine content, 3-50wt% remaining crystal, 1.1-1.3 specific gravity, is uniformly blended with (B) 20-80pts.wt. electrically-conductive carbon black consisting of B1: 100pts.wt. carbon black having 1,100-1,300m<3>/g surface area and B2: 50-120pts.wt. carbon black having 200-300m<3>/g surface area, (C) 1.0-15pts.wt. inhibitor for dehydrochlorination of a vinyl chloride polymer (e.g., metallic soap, organotin compound), and (D) 0.1-20pts.wt. organic peroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION [I] OBJECTS OF THE INVENTION The present invention relates to a conductive composition containing at least two types of chlorinated preethylene and two types of conductive carbon black. More specifically, (5) amorphous chlorinated polyethylene, ■) crystalline chlorinated polyethylene, (C) two types of conductive carbon black with different surface areas, ■ vinyl chloride polymer, and (6) organic peroxide. The purpose of the present invention is to provide a composition that has excellent electrical conductivity and is particularly promising for parts of electrical appliances.

[■] Background of the Invention Rubber compositions having electrical conductivity are widely used as electrical materials such as switches or connectors of electrical appliances and heating elements, and as antistatic materials for packaging materials and the like. Many rubber compositions are known in which a conductive substance (eg, carbon black, metal powder) is added to various types of rubber. However, metal powder
When obtaining a composition with high specific gravity and excellent electrical conductivity, a large amount of metal powder must be added, which reduces the mechanical properties (e.g., tensile strength) of the composition, making it impractical. isn't it.

From the above, many of the commonly used conductive rubber compositions are rubber with carbon black (eg, acetylene black, conductive furnace black) added thereto. However, in order to incorporate carbon black into rubber and obtain a composition with sufficient electrical conductivity, a considerable amount of carbon black must be added. For example, in order to reduce the volume resistivity of styrene-butadiene rubber to 100 mm or less, approximately 100 parts by weight of carbon black must be added to 100 parts by weight of rubber. In this way, when a large amount of carbine black is added to improve conductivity, the resulting composition not only has poor moldability, but also fails to have mechanical properties that can withstand practical use.

[TII) Structure of the Invention In light of the above, the present inventors have conducted various searches to obtain a rubber composition that has excellent conductivity and does not have these drawbacks. (5) A rubber composition with a chlorine content of 20 (B) crystalline chlorinated polyethylene having a chlorine content of 20 to 50% by weight and residual crystals of 3 to 50 parts by weight; (C) a surface area of 3 to 50 parts by weight; 200 to 300 m2/I conductive carbon black [hereinafter referred to as "conductive carbon black (1)"
”) and surface area of 1.100 to 1.300 m
2/9 conductive carbon black (hereinafter referred to as "conductive carbon black (2)"))) is a composition consisting of a dehydrochlorination inhibitor for a vinyl chloride polymer and (Q) an organic peroxide; The composition of crystalline chlorinated polyethylene relative to the amorphous chlorinated polyethylene in the heavy background is 50 to 120 parts by weight, and the composition ratio is based on 100 parts by weight of the total amount of amorphous chlorinated polyethylene and crystalline chlorinated polyethylene. The total amount of biconductive carbon black is 20 to 80 parts by weight, the dehydrochlorination inhibitor is 1.0 to 15 parts by weight, and the organic peroxide is 0.
1 to 20 parts by weight of conductive carbon black (1 to 20 parts by weight), 1100 weight parts of conductive carbon black (2)
) has a composition ratio of 50 to 120 parts by weight.The conductive composition has good conductivity, good moldability, and does not have the above-mentioned drawbacks. They discovered this and arrived at the present invention.

[■] Effects of the Invention The conductive composition of the present invention exhibits the following effects (characteristics) despite the relatively large amount of conductive carbon black (high loading).

(1) Excellent formability (flow characteristics).

(2) Mechanical strength (for example, tensile strength, tear strength) is good.

(3) Excellent electrical conductivity is obtained even in compositions with low loadings of carbon black relative to amorphous and crystalline chlorinated polyethylene.

(A) Excellent flexibility.

(5) Good workability (for example, kneading properties).

Furthermore, mechanical strength can be further improved by crosslinking.

As described above, the conductive composition obtained by the present invention is
It is not only good in conductivity, but also has the above-mentioned excellent features, so it can be used in a wide variety of fields. Its uses are as follows.

(1) Switch materials for electrical appliances (2) Connectors for electrical appliances (3) Surface heating elements (A) Antistatic agents such as packaging materials (5) Connectors that provide guidance on digital displays to check indicators during exercise (6) Health management Ultrasonic contact devices such as devices [Vl
Detailed Description of the Invention (A) Amorphous chlorinated polyethylene and crystalline chlorinated polyethylene Both the amorphous chlorinated polyethylene and the crystalline chlorinated polyethylene used in the present invention are obtained by preparing polyethylene powder or particles in an aqueous suspension. or by chlorinating polyethylene dissolved in an organic solvent (preferably by chlorinating it in an aqueous suspension). All of them are chlorinated polyethylenes having a chlorine content of 20 to 50% by weight, and amorphous and crystalline chlorinated polyethylenes having a chlorine content of 25 to 45% by weight are particularly preferred.

The polyethylene is obtained by homopolymerizing ethylene or copolymerizing ethylene with at most 20% by weight of α-olefin (generally having at most 12 carbon atoms). Their density is generally 0.900~
It is 0.980/cc. Also, their molecular weight is 50,000~
It is 800,000.

The crystalline chlorinated polyethylene of the present invention has a polyethylene crystal content of 3 to 50% by weight, and its typical characteristics are as follows:
Specific gravity is 1.10-1,30, JISK-6301
Tensile breaking strength is 100~ in tensile test measurement according to
150Kg/crIL2, tensile elongation at break is 500
It is in charge of ~800. In addition, hardness Shore A) is 70~
90, and the volume resistivity (measured by ASTM D-254) is 1.0×10 to 1.0×10150.It exhibits characteristics such as a sieve. The X-ray wide-angle diffraction pattern was analyzed using an X-ray wide-angle diffractometer (
Figure 1 shows the X-ray wide-angle diffraction diagram of the crystalline chlorinated polyethylene used in the example in which Cu- was measured with alpha rays using a product manufactured by Rigaku Denki Co., Ltd. (trade name: IGAFLEX 2028).
Furthermore, the X-ray wide-angle diffraction diagram of the non-quality chlorinated polyethylene used in the Examples and Comparative Examples is shown as the dotted line (a) in Figure 2, and these chlorinated 4? The wide-angle X-ray diffraction pattern of the ethylene-butene-1 copolymer used as a raw material for polyethylene is shown as the solid line (b) in FIG. According to the wide-angle X-ray diffraction diagram, ethylene-butene-1 copolymer (crystalline polyethylene) has a Bragg angle of 2θ = 21° (1
It can be seen that a crystallinity peak of (200 plane) is shown at the 10) plane and the Bragg angle 2θ=24°.

In addition, for non-grade chlorinated polyethylene, Bragg angle 2θ = 1
Although amorphous peaks appear from 2 to 13 degrees, the crystalline peak of the crystalline polyethylene completely disappears. Furthermore, crystalline chlorinated polyethylene has a Bragg angle of 2θ
It shows a peak equivalent to that of non-grade chlorinated polyethylene at =12 to 13°, and Bragg angles of 20 = 2]' and 24
It is clear that the crystallinity peaks depending on the crystalline polyethylene are shown at each angle. In Figure 1,
The amount of crystalline polyethylene in the whole is 10 to 15 inches, and this amount can be arbitrarily changed depending on the manufacturing conditions of chlorinated polyethylene.

In producing the composition of the present invention, only amorphous chlorinated polyethylene and crystalline chlorinated polyethylene may be used, but other types of polymeric substances that are miscible with crystalline chlorinated polyethylene may be blended. It's okay. Examples of the polymeric substances include ethylene-zologycine-diene ternary copolymer comb (EPDM), natural comb, chlorozolene comb,
Chlorosulfonated polyethylene rubber, styrene
Rubbery products such as butadiene copolymer rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR), and butadiene homopolymer rubber [generally,
The Mooney viscosity (ML, +4) is 10 to 200]. In addition, other polymeric substances include the above-mentioned polyethylene, vinyl chloride resin containing vinyl chloride as the main component (degree of polymerization, 400-1800), methyl methacrylate resin containing methyl methacrylate as the main component, and acrylonitrile-styrene copolymer resin. Examples include resin-like substances such as. Regarding these rubber-like substances and resin-like substances, please refer to “Synthetic Rubber Handbook” edited by Kambara et al.
(Published in 2013), ``Plastic Handbook'' (edited by Murahashi et al.)
It is well known by Asakura Shoten, published in 1962).

When blending other types of rubbery substances, their blending ratio is 1
00 parts by weight of amorphous chlorinated polyethylene and crystalline chlorinated polyethylene.

(B) Conductive carbon black Furthermore, conductive carbon black (1) and carbon black (2) used in the present invention are all channel black, acetylene black, and rubber distribution carbine black produced by the Furnace rack method. and other conductive carbon blacks. For information on these carbon plastics, please refer to the Carbon Black Association Network °'Carbon Black Handbook'' (Tosho Publishing Co., Ltd., published in 1972), Rubber Digest Co., Ltd., Compound Compound Chemicals'' (Rubber Digest Co., Ltd., Their manufacturing methods and physical properties are well known from the above-mentioned "Synthetic Rubber Handbook" (published in 1972).

The surface area of the conductive carbon black (1) is 200 to 300 m2/i as measured by low temperature nitrogen adsorption method and BET method, and particularly preferably 200 to 280 m27g. Conductive carbon black (1) with a surface area of 200 m2/
,! When using conductive carbon black less than i',
A composition with excellent conductivity cannot be obtained.

On the other hand, if conductive carbon black exceeding 300 m2/I is used, the resulting composition has excellent conductivity, but
Poor workability and lack of hardness are both undesirable. Furthermore, the surface area of the conductive carbon black (2) is i, io as measured by the method described above.

~1.300 m2/,! 9, and the difference is 1.15
0~], 300 m2/g is desirable. As conductive carbon black (2), the surface area is 1.100 m2/7
If less conductive carbon black is used, it will be difficult to obtain a composition with excellent conductivity. On the other hand, 1,300
If conductive carbine exceeding m2/g is used, the processability of the composition will not only be poor, but it will also become hard, which is undesirable.

(C) Dehydrochlorination inhibitor Furthermore, the dehydrochlorination inhibitor used in the present invention is generally a polymer containing nitrogen atoms (mainly chlorine atoms), such as a vinyl chloride polymer, that is It is widely used to prevent the dehydrochlorination that occurs. The dehydrochlorination inhibitors are broadly classified into metal soaps, inorganic acid salt metal compounds, organic tin compounds, and pure organic compounds.

Among these, typical examples of metal soaps include metal salts of organic carboxylic acids having 1 to 10 carbon atoms (which may be substituted with at most 3 chlorine atoms). Such metals include lithium, magnesium, calcium, strontium, barium, cadmium, aluminum and lead.

Other metal soaps include lead salts of carboxylic acids such as tribasic maleic acid, dibasic phthalic acid and salicylic acid. In addition, examples of inorganic acid salts include alkylaryl cadmium sulfite, lead orthosilicate-silica glu coprecipitate, basic lead silicate, tribasic lead sulfate, basic lead sulfite, and dibasic lead phosphite. can give. Among metal oxides, magnesium oxide is preferably used. Furthermore, examples of organic tin compounds include diptyl tin dilaurate, octyl tin compounds, dimethyl tin compounds, diptyl tin malate, sulfur-containing organotin compounds, stannane diol derivatives, and diptyl-1-
Examples include C-tin-β-mercazotoprono and phate. Examples of pure organic compounds include chelating agents [the general formula is shown in formula (1)] and epoxy compounds.

In formula (1), R1, R2 and R3 may be the same or different and are hydrocarbon groups having at most 20 carbon atoms.

Furthermore, other dehydrochlorination inhibitors include stearoylbenzoylmethane and balmitoylbenzoylmethane. .

These dehydrochlorination inhibitors are listed in “
Handbook, Rubber/Plastic Compound Chemicals'' (1971,
Published by Rubber Digest, page 266, page 31
．． It is described on page 9. Among these dehydrochlorination inhibitors, inorganic acid salts, metal oxides, and organic tin compounds are preferred, and inorganic acid salts and metal oxides are particularly preferred. In particular, dibasic lead phthalate, dibasic lead stearate, tribasic sulfuric acid, basic lead silicate, magnesium oxide and lead oxide are preferred.

(D) Organic peroxide The organic peroxide used in the present invention is not particularly limited, but it is particularly desirable to have a decomposition temperature (temperature at which the half-life is 1 minute) of 120°C or higher, particularly 140°C. ℃
The above are preferred.

Representative examples of suitable organic peroxyoxides include i,1-bis-tertiary-butylperoxy-3,3,5-)! Ketones/F-oxides such as J methylcyclohexane, 2
, 5-dimethylhexane-2,5-dihydro-i4-oxide, hydroperoxides such as 2,5-dimethyl-2,5-di-tertiary-butyl-oxyhexane, monooxyesters such as penzoyl, -oxides such as noarsilver oxide and dialkyl peroxides such as dicumyl peroxide.

Furthermore, polyfunctional substances such as triallyl isocyanurate and triallyl isocyanurate, which are commonly used as crosslinking aids in the rubber field, may be blended.

(E) Composition ratio In producing the composition of the present invention, the composition ratio of crystalline chlorinated polyethylene to 100 parts by weight of amorphous chlorinated polyethylene is 50 to 120 parts by weight, and 50 to 120 parts by weight.
The amount is preferably 110 parts by weight, particularly preferably 50 to 100 parts by weight. If the composition ratio of crystalline chlorinated polyethylene to 100 parts by weight of amorphous chlorinated polyethylene is less than 50 parts by weight, the resulting composition will have low conductivity. on the other hand,
When the amount exceeds 120 parts by weight, the resulting composition has good conductivity but poor flexibility.

The composition ratios of conductive carbon black, dehydrochlorination inhibitor, and organic peroxide relative to 100 parts by weight of amorphous chlorinated polyethylene and crystalline chlorinated polyethylene are as follows.

Regarding the conductive carbon black, the total amount of conductive carbon black (1) and conductive carbon black (2) is 20 to 80 parts by weight, preferably 30 to 75 parts by weight, and 30 to 70 parts by weight. Parts by weight are preferred. If the total amount of conductive carbon black is less than 20 parts by weight, the resulting composition will have low conductivity. On the other hand, 80
If the amount exceeds 1 part by weight, the resulting composition will have good conductivity but poor flexibility. Further, the amount of the dehydrochlorination inhibitor is 1.0 to 15 parts by weight, preferably 1.0 to 13 parts by weight, and particularly preferably 2.0 to 10 parts by weight.

If the composition ratio of the dehydrochlorination inhibitor is less than 1.0 parts by weight,
This is not preferred because the resulting composition undergoes dehydrochlorination and the composition deteriorates. On the other hand, even if more than 15 parts by weight is added, the effect cannot be improved. Regarding organic peroxide, it is 0.1 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and divided into 1.0 to 20 parts by weight.
10 parts by weight is preferred. Composition ratio of organic peroxide is 0
．． If it is less than 1 part by weight, a good crosslinked product will not be obtained, the surface of the product will be rough, and a good product will not be obtained. On the other hand, if it exceeds 15 parts by weight, the resulting product will be hard and flexible.

Furthermore, 100 parts by weight of conductive carbon black (2)
The composition ratio of conductive carbon black (1) to
It is 0 to 120 parts by weight, preferably 50 to 110 parts by weight, and preferably 50 to 100 parts by weight. If the composition ratio of the conductive carbon black (1) to 100 parts by weight of the conductive carbon black (2) is less than 50 parts by weight, the resulting composition will not have good conductivity. On the other hand, when the amount exceeds 120 parts by weight, the resulting composition has excellent conductivity, but
Not very flexible.

(F') Mixing method, molding method, etc. Although the composition of the present invention can be obtained by uniformly blending the above substances, fillers and plasticizers commonly used in the rubber industry and resin industry, Additives such as oxygen, ozone, heat and light (ultraviolet) stabilizers, lubricants and colorants may be added depending on the intended use of the composition. Furthermore, additives such as sulfur vulcanizing agents, sulfur-releasing compound-based vulcanizing agents, and amine-based vulcanizing agents commonly used in the comb industry and resin industry may be added depending on the intended use of the composition. good.

When producing the composition of the present invention, the blending (mixing) method is as follows: Mixing may be carried out using a mixer such as an open roll, a dry blender, a Banbury mixer, and a Nigu mixer commonly used in the art. good. Among these mixing methods, in order to obtain a more uniform composition, two or more of these mixing methods may be applied (for example, after mixing in advance with a dry blender, the mixture may be mixed using an open roll. How to mix).

To produce the composition of the present invention, all the ingredients may be mixed at the same time, but some of the ingredients may be mixed in advance and then the other ingredients may be mixed into the resulting mixture. (For example, after mixing crystalline chlorinated polyethylene and amorphous chlorinated polyethylene in advance,
method of mixing the resulting mixture with other ingredients)
.

The composition of the present invention may be molded into a desired shape using a molding machine commonly used in the rubber industry, such as an extrusion molding machine, an injection molding machine, a compression molding machine, or a calendar molding machine. In addition, a method is applied in which crystalline chlorinated polyethylene or the above-mentioned composition is added to produce a molded product while vulcanization (crosslinking) is generally performed in the rubber technology field, that is, a method in which vulcanization and molding proceed simultaneously. It may be molded into a desired shape.

As mentioned above, the composition of the present invention has high electrical conductivity (103
less than Ω・鑞). Furthermore, the brittleness, hardness, and mechanical properties of commonly used conductive rubber molded products have been significantly improved.
The composition of the present invention has extremely great practical value.

[VD Examples and Comparative Examples The present invention will now be explained in more detail with reference to Examples.

In the Examples and Comparative Examples, the hardness was measured using a JIS hardness meter (Shore A) by stacking three JISA3 dumbbells according to test piece JISK-6301. Resistance meter (manufactured by Takeda Riken Co., Ltd., product name Digital Multimeter TR-68
56), using a specimen with a thickness of 2 mm, at a temperature of 25°C.
The resistance of the specimen was measured in an atmosphere with a humidity of 60 degrees, and calculated according to the formula below.

Here, S is the electrode area of the specific resistivity measuring electrode, hD, R
is the resistance value of the specimen, and t represents the thickness of the specimen.

In addition, in the bending test, the thickness was 21nrL1 width was IQiim
A sheet with a length of 100 mm is wrapped around a cylinder (10 mm in diameter), and the cracks on the surface observed with the naked eye are ranked in 3 stages according to the following criteria.

Rank Degree of cracks on the surface ○ No cracks at all △ Slight cracks × Large overlaps and cracks Examples 1 to 7, Comparative Examples 1 to 6 Ethylene containing 3.0% by weight of butene-1 -Butene-
1 copolymer (density 0.94017 cc, average molecular weight approximately 150,000 cc) was chlorinated in an aqueous suspension to obtain crystalline chlorinated polyethylene [chlorine content 30.2% by weight, residual crystal content of polyethylene 7. 15 Weight factor, Mooney viscosity (ML
110, hereinafter referred to as 1-BCPE, J] was produced.

Also, the density is 0.950! ? /cc polyethylene [chlorine content 40% by weight, amorphous, Mooney viscosity (MS
4. ) 80, hereinafter referred to as "CPEJ".

BCPE and CPE produced in this way were used as rubber-like materials, and 10 parts by weight of each tribasic lead sulfate was added as a dehydrochlorination inhibitor (however, it was not added in Comparative Example 6), and dioctyl phthalate was added as a plasticizer. 30 parts by weight (however, not added in Examples 1 and 5 and Comparative Examples 1 and 2), 4 parts by weight each of dicumyl peroxide as an organic peroxide, and 3 parts by weight each of triisocyanurate as a crosslinking aid. Furnace black with an average particle size of approximately 30 mm as carbon black
(Vulcan) XC-72, density approximately 1.8E
/cc,.

Surface area 258 m2/I, hereinafter referred to as "C-1"] Oyobi Ketjen Black (manufactured by Akzochemy, Netherlands, trade name Ketjen Black, density 1.8 g/cQ).

BCPE, CPE, C-1, and C-2 were thoroughly kneaded for 20 minutes using a sheet with a surface area of 1195 m27 g (hereinafter referred to as "c-2J"), and formed into a sheet.

Among the sheets obtained as described above, some of the sheets were pressed for 5 minutes at a temperature of 70° C. and a pressure of 100 KgAL2 to create a sheet.

A hardness test, a bending test, and a measurement of the volume resistivity value of each sheet were conducted in this manner. The results are shown in Table 1.

In Comparative Example 6, dehydrochlorination occurred during press molding, and a sheet could not be created.

From the results of the above Examples and Comparative Examples, it is clear that the conductive composition obtained by the present invention not only has excellent flexibility in hardness and bending tests, but also has good volume resistivity. Therefore, it is clear that it has great potential in the future as a switch material for electrical appliances, connectors, ultrasonic contacts, etc.

[Brief explanation of drawings]

FIG. 1 is an X-ray wide-angle diffraction diagram of crystalline chlorinated polyethylene (BCPE) used in Examples. In addition, (a) (dotted line) in Figure 2 shows the
This is a line wide-angle diffraction diagram, and (b) (solid line) in Figure 2 shows the ethylene-
FIG. 2 is an X-ray wide-angle diffraction diagram of a butene-1 copolymer. IQ 15 20 25
30 Procedural Amendment (Method) Date of November 1982

Claims (1)

[Scope of Claims] (A) Amorphous chlorinated polyethylene having a chlorine content of 20 to 50% by weight; (B) A chlorine content of 20 to 50% by weight and remaining crystals of 3 to 50% by weight % of crystalline chlorinated polyethylene, (C) conductive carbon black (1) with a surface area of 200 to 300 m^2/g and a surface area of 1,100 to 1,3
00m^2/g conductive carbon black (2), (D
) A dehydrochlorination inhibitor for vinyl chloride polymers and (E) an organic peroxide, and the composition ratio of crystalline chlorinated polyethylene to 100 parts by weight of amorphous chlorinated polyethylene is 50 to 120 parts by weight. The total amount of amorphous chlorinated polyethylene and crystalline chlorinated polyethylene is 100 parts by weight.
Regarding the composition ratio to parts by weight, the total amount of biconductive carbon black is 20 to 80 parts by weight, the dehydrochlorination inhibitor is 1.0 to 15 parts by weight, and the organic peroxide is 0.
．． The amount of conductive carbon black (1 to 20 parts by weight) per 100 parts by weight of conductive carbon black (2) is 1 to 20 parts by weight.
) has a composition ratio of 50 to 120 parts by weight.