JPS6178872A - Conductive resin composition - Google Patents

Abstract

PURPOSE:A conductive resin composition having excellent flexing durability, made by incorporating a conductive metal compound and agents for rendering lipophilic into a thermoplastic resin. CONSTITUTION:A thermoplastic resin (A) (e.g., a polyethylene, a polystyrene or a polyethylene terephthalate), a conductive metal compound (B) (e.g., stannic oxide or zinc oxide), and agents for rendering lipophilic (C), preferably an organic carboxylic acid of at least 6C (e.g., n-caproic acid) and/or an organic sulfonic acid of at least 5C (e.g. n-pentasulfonic acid), preferably in an amount of about 0.3-3pts.wt. based on 100pts.wt. conductive metal oxide, are mixed to give a conductive resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a conductive resin composition, particularly a conductive resin composition having excellent bending resistance.

(1)) Prior Art Thermoplastic resins such as polyethylene, polyamide, polyester, etc. are used in many applications as fibers, films, and molded products.

However, such thermoplastic resins generally have poor antistatic properties and are easily charged. For example, clothing made of polyester polyethylene terephthalate llAl#
Due to its electrostatic properties, it may cling to the body when worn,
Furthermore, due to the electrification, it attracts dust floating in the air, which causes many problems such as easy staining.

As a method for solving this problem, methods have been proposed such as adding an electrically conductive compound to the resin in advance or adding a conductive substance such as conductive carbon to the resin.

However, for example, conductive 111 g, conductive film obtained from resin blended with conductive carbon.

Since the conductive carbon of conductive seals such as L- is black,
It has the disadvantage that it is extremely colored and cannot be used in fields where aesthetics are required, and its uses are extremely limited.

As a method to solve the drawbacks caused by such coloring, the recent 11
．． A method of obtaining conductive fibers, conductive films, etc. using a colorless or light-colored conductive resin composition blended with a bright-colored or light-colored conductive metal compound, particularly a conductive metal oxide, has been proposed.

(C) Problems to be solved However, conductive fibers, conductive films, etc. manufactured based on these proposals lose their conductivity after being bent several dozen times, and it is expected that they will lose their conductivity in a short time when worn. As a result of losing the antistatic effect, if the clothes cling as mentioned above,
Causes dust to accumulate.

(d) As a result of intensive research into a method for providing a conductive molded product free from such drawbacks, the inventors at Yamakatsu discovered that the surface of the conductive metal oxide powder is hydrophilic and has an affinity with thermoplastic resins. We found that this was due to the small flexural properties of the conductive metal oxide, and after making the surface of the conductive metal oxide lipophilic, if we made a molded product using a thermoplastic resin blended with this, we could create a conductive product with bending durability. The present invention was achieved based on the discovery that a molded product with a soft texture can be obtained.

That is, the present invention combines a conductive metal compound and a lipophilic agent into a thermoplastic 1! Conductive resin composition blended with I resin The thermoplastic resin in the present invention is polyethylene.

This is related to b.

Polypropylene, polystyrene, polybutadiene.

Polyisoprene, nylon-6, nylon-6,6° polyethylene terephthalate, polybutylene terephthalate
The main targets are 1 to 1, but some of these may be replaced with copolymer components, and if it is a thermoplastic resin, resins other than the above may be used depending on the purpose. Depending on the situation, a combination of two or more of these may be used.

The electrically conductive metal compound referred to in the present invention mainly refers to electrically conductive metal oxides, and particularly preferred are stannic oxide and zinc oxide. The stannic oxide mentioned here also includes stannic oxide containing a small amount of antimony compound, and a conductive metal composite obtained by coating the surface of titanium chloride particles with stannic oxide containing a small amount of antimony compound. included. Zinc oxide also includes conductive zinc oxide in which a small amount of aluminum oxide or lithium oxide is dissolved. These are usually treated as fine powders.

As a lipophilic agent for such conductive metal oxide, carbon number 6
The above organic carboxylic acids and organic sulfonic acids having 5 or more carbon atoms are preferred, and the carboxyl group.

Organic residues that bind to sulfonic acid groups include alkyl groups,
Those having an alkylene group, an aryl group, an alkylaryl group, or an aralkyl group are preferred, and as long as these groups are groups other than carboxyl, they may have any substituent.

Specific examples of organic carboxylic acids used as lipophilic agents include n-caprone ftl and n-hebutanoic acid.

Benzoic acid, n-caprylic acid, phenylacetic acid, toluyl f
lJ, n-nonanoic acid, n-caprylic acid. Examples include stearic acid. Further, specific examples of organic sulfonic acids include low pentanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, and the like. These organic carboxylic acids and organic sulfonic acids used as lipophilic agents may be used alone or in appropriate combinations.

The number of carbon atoms in the organic carboxylic acid used as a lipophilic agent is 5.
In the following cases and when the number of carbon atoms in the organic sulfonic acid is 4 or less, it is clear from the lipophilicity determination described below that the conductive metal oxide after lipophilic treatment moves to the water layer and is not lipophilic. However, the bending durability of a conductive molded article made from a thermoplastic resin blended with a treated conductive metal oxide does not improve.

The method for making conductive metal oxides lipophilic varies depending on the type of thermoplastic resin used and the type of lipophilic agent.
Considering the thermal properties of organic carboxylic acids and organic sulfonic acids as lipophilic agents, (1) A method of directly melt-mixing a thermoplastic resin, a conductive metal oxide, and a lipophilic agent (2) Conductive metal It is preferable to appropriately select either a method in which the oxide is treated with a lipophilic agent in advance or a method in which the oxide is melt-mixed with a thermoplastic resin.

For example, an organic carboxylic acid with a low boiling point such as n-hebutanoic acid is used as a lipophilic agent and is directly melt-mixed with a conductive metal compound into a thermoplastic resin with a high melting point such as polyethylene terephthalate-1. It is not preferable to try to obtain resin composition power. In such a case, it is preferable to treat the conductive metal oxide with n-hebutanoic acid in advance and then melt-mix it with the thermoplastic resin.

On the other hand, even if the same n-hebutanoic acid is used as the lipophilic agent, if the thermoplastic resin used has a relatively low melting point such as polyethylene, the conductive metal oxide and n-hebutanoic acid may be mixed together. There is no problem even if it is directly melt-mixed with polyethylene.

As a method for making the conductive metal oxide lipophilic in advance,
It is extremely simple: the desired conductive metal oxide powder is inhaled and dispersed in the solution obtained by dissolving the lipophilic agent in an organic solvent, and after stirring for several hours, the frozen melt and the powder are separated by filtration. methods are used.

The amount of the lipophilizing agent used is preferably kept to a necessary and sufficient minimum amount, and is preferably in the range of 0.1 to 3 parts by weight per 100 parts by weight of the conductive metal oxide powder. If the amount of the lipophilic agent is less than 0.1 parts, it may be difficult to make the surface of the conductive metal oxide sufficiently lipophilic by the treatment. In addition, if the amount exceeds 3 parts by weight, it may become difficult to filter it from the solvent dispersion after treatment, or it may be necessary to remove the excess lipophilic agent by 8% after filtration. I don't like it.

In addition, lipophilic agent and conductive gold fili! Direct heat pJ with compound
When melt-mixing with a plastic resin, it is not preferable to add an excessive amount of the lipophilic agent because it impairs the physical properties of the thermoplastic resin.

In the method of pre-treating the conductive metal compound with a lipophilic agent,
As mentioned above, it is possible to make the material lipophilic by adding and dispersing the conductive metal compound into the organic solvent solution of the lipophilic agent and stirring it at room temperature for several hours (), but in order to process it in a shorter time, it is necessary to heat it. is effective.

The solvent used here is not particularly limited as long as it dissolves the organic carboxylic acid and/or sulfonic acid compound that is the lipophilic agent, but if heat treatment is required, a solvent with a low boiling point should be used. Undesirable.

If the conductive metal oxide is not lipophilic and therefore does not have sufficient affinity with the thermoplastic resin, the resulting resin composition may be molded [i. It is extremely important in the present invention to determine whether or not the conductive metal oxide has been sufficiently made lipophilic in order to cause serious defects. This is extremely important as it serves as the standard for determining the amount of oxidizing agent to be used. In particular, conductive metal oxides are directly dissolved in thermoplastic resins together with lipophilic agents.
In the case of a, it is important to determine in advance the necessary and sufficient amount of the lipophilic agent, and from this point of view, it is necessary to select an appropriate determination method.

This determination method involves heating and stirring in a solution in which a lipophilic agent is dissolved in an organic solvent to make it lipophilic, and then applying a conductive metal compound powder to water and an organic solvent that is incompatible with water. It is extremely effective to assume that when the conductive metal compound powder transfers to the organic layer and becomes lipophilic when it is poured into a liquid consisting of a layer and left to stand after stirring 1'f. .

A lipophilized conductive metal compound is melted with a thermoplastic resin.
When mixing, or when directly melt-mixing a conductive metal compound and a lipophilic agent necessary for making the conductive metal compound lipophilic, in order to mix effectively, For the purpose of improving the moldability of the resulting conductive resin composition, an appropriate viscosity modifier may be used, and if necessary, an antioxidant may also be used in combination.

Fibers, films, sheets, etc. formed from a resin composition made by combining a conductive metal compound made lipophilic with a thermoplastic resin according to the present invention do not lose their conductivity when bent, and are extremely durable. Maintains high performance and vines.

Oral m The present invention will be specifically explained below using Examples.

Example 1 SI powder 1 of titanium oxide fine particles coated with conductive tin oxide and having an average particle size of 0.2μ and a specific resistance of 10Ω・α.K9 and 20J of rhohebutanoic acid were added with 3 grams of toluene. Heat to reflux for 5 hours with vigorous stirring. After the mixture was allowed to stand overnight, most of the toluene was removed by decantation, and the powder was filtered, thoroughly washed with toluene, and dried. When a small amount of this dry powder was poured into a liquid for determining lipophilicity consisting of two layers of 100 d of water and 100 d of benzene and shaken, the powder moved to the benzene layer and was made lipophilic. It was determined that The untreated conductive powder was in the aqueous layer, and the conductive powder treated in the same manner as above except that tCn-hebutanoic acid was not added also moved to the aqueous layer.

250 parts by weight of lipophilized powder, 20 parts by weight of liquid paraffin and melt index 75 (JIS K676
0-1971) in a kneader.
The mixture was heated to 175°C and mixed for 5 hours. The specific resistance of the obtained conductive resin was 4×10 2 Ω·cm. By melt-spinning, a core-sheath type composite fiber (core-sheath ratio -1/6) with this conductive resin as a core and polyethylene terephthalate as a sheath was made, and it was drawn 4 times to make a conductive multi fiber with a denier of 100 and a single yarn count of 12. I got the filament. This conductive composite m-fiber was cut to a length of 1CIR, conductive paint was applied to both ends, and the electrical resistance between both ends was measured.
X 10'Ω.

Furthermore, this conductive composite Jl fiber was cut to a length of 20 (-Jl), a weight of IOog (1 g per denier) was hung on one end, and the other end was hung up and down by a freely rotating support rod with a diameter of 1#1111. The relationship between the number of bends and the electrical resistance was investigated by the method of repeatedly bending the thread using the U method, cutting off the central part of the thread, applying conductive paint to both ends, and measuring the electrical resistance between both ends. The values shown in the left column of Table 1 are 1.

For comparison, conductive composite fibers obtained in the same manner except for using conductive powder that was not subjected to lipophilic treatment with n-hebutanoic acid were subjected to a bending test. The results are shown in the right column of Table 1. Indicated.

(Margin below) Table 1 Example 2 250 parts by weight of the untreated conductive powder described in Example 1,
80 parts of polyethylene with a melt index of 15 was charged into a kneader and kneaded at 175°C for 30 minutes. h
20 parts by weight of paraffin, 3 parts of stearic acid as a lipophilic agent
Parts by weight were added and kneaded for an additional 4 hours.

The specific resistance of the obtained conductive resin is 2.8X 102Ω・α
Met.

A conductive composite U&miscellaneous was obtained having this conductive resin as a core and polyethylene terephthalate i- as a sheath in the same manner as in Example 1. This I! Regarding miscellaneous matters, a bending test was conducted using the same method as in Example 1 to examine the relationship between the number of bends and the electrical resistance value, and the results shown in the left column of Table 2 were obtained.

For comparison, a similar test was carried out on III, which had a core of resin prepared with exactly the same amount of charge except that stearic acid was not mixed, and the results are shown on the right side of the same table.

Table 2 Examples 3 to 6 Conductive resins were prepared in the same manner as in Example 1, using various acids shown in Table 3 instead of the lipophilic agent n-heptanoic acid used in Example 1. However, in the same manner as in Example 1, a composite fiber having this resin as a core and polyethylene terephthalate as a sheath was prepared, and the change in electrical resistance due to bending was examined. - The results shown in Table 3 are all good results.

(Leaving space below) Table 3 Comparative Examples 1 to 4 The conductive powder shown in Example 1 was prepared by using various acids shown in Table 4 instead of n-hebutanoic acid used in Example 1. was processed. The treated powder was put into a test solution consisting of two layers of water and liquid paraffin and shaken, but 1 Wf
The fi-like powders were all in the water layer. Real 7+1 using this powder! Composite II having a polyethylene terephthalate sheath was prepared in the same manner as Example I, and the change in electrical resistance due to bending was investigated.

The results are shown in Table 4.

(Left below) Table 4 implementation l+! I7 Conductive metal powder made of stannic oxide containing a small amount of antimony trioxide 250 heavy lifting weight Melt flow index 1
．． 0 (ASTM n1238-65T) polypropylene was charged into a Nigu and melted at 200°C for 30 minutes, followed by 3 parts by weight of stearin M.

50 parts by weight of liquid paraffin, Irganox 10100
．． 5 parts by weight were added and kneaded for a further 4 hours.

The specific resistance of the conductive resin thus obtained was 5.5×102Ω・
It was the mouth. By melt spinning, a core-sheath type composite fiber (core-sheath ratio =
115) and stretched four times to obtain a 100 denier conductive multifilament with a monofilament number of 12.

This conductive composite fiber was cut into a length of 1 cta, and the electrical resistance was measured in the same manner as in Example 1.
It was 10'Ω.

As a matter of fact, the changes in electrical resistance of this fiber depending on the number of bends were investigated in the same manner as in Example 1, and the results are shown in the left column of Table 5.

For comparison, C was prepared in the same manner except that stearic acid was not used.
+r/1. :M composite fibers were similarly examined for changes in electroacidity depending on the number of bends, and the results are shown in the right column of the M5 table. When stearic acid was not added, conductivity was lost after 100 bends.

(Leaving space below) Table 5 Patent Applicant Teijin Co., Ltd. Company Procedures JE Book July/2, 1985 'l''J' IT Office Director's Office 1, '■ Matter Indication of Vi Application No. 59-199357 No. 2, Title of Invention Conductive Resin Composition 3, Supplement 1 [Relationship with the Case Patent Applicant: Teidai Co., Ltd., 1-11 Minamihonmachi, Higashi-ku, Osaka (300) Representative Okamoto Hiroshibe 4, immediately entered 2-1-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo (1) Ming #I Kodai/I Sada lines 1-3
1. Conductive resin composition blended with plastic bamboo resin Heat 6 [Plastic resin refers to polyethylene] in the present invention. '' This is related to a conductive resin composition formed by blending ``with a thermoplastic resin.''

The thermoplastic resin referred to in the present invention is polyethylene, 1 and iif i[rJ-ru.

(2) In 1i11, page 7, line 12, correct the word "inhalation" by adding U.

(3) On page 14, line 3, 1 melt index 75
1 is corrected to 1 of Melt Index 15.

that's all

Claims (3)

[Claims] (1) A conductive resin composition formed by blending a conductive metal compound and a lipophilic agent with a thermoplastic resin. (2) The conductive resin composition according to claim 1, wherein the lipophilic agent is an organic carboxylic acid compound having 6 or more carbon atoms and/or an organic sulfonic acid compound having 5 or more carbon atoms. (3) The conductive resin composition according to claim 1 or 2, wherein the conductive metal compound is stannic oxide and/or zinc oxide.