JPS6347824B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to conductive fibers containing copper sulfide and a method for producing the same, and in particular to synthetic or natural conductive fibers that do not have cyano groups, such as polyamide fibers, polyester fibers, and rayon fibers. The purpose of this method is to introduce cyano groups into the fibers, contain copper sulfide through the cyano groups, and impart electrical conductivity to the fibers.

Conventionally, conductive fibers have been manufactured by methods such as applying metal plating to the surface of the fibers and kneading metals into polymers, but these methods have various drawbacks in terms of manufacturing and product quality. Ta. Therefore, the present inventors proposed a method for manufacturing conductive fibers made of acrylic fibers or acrylic fibers in order to overcome the drawbacks of the above-mentioned conventional techniques (Japanese Patent Application Laid-open No.
55-51873). This method consists of first adsorbing monovalent copper ions onto acrylic fibers in the first step, and then applying a reducing agent to the fibers in the second step.

The present inventors subsequently conducted various studies in order to impart conductivity to synthetic fibers that do not have cyano groups, and as a result, they have completed the present invention.

That is, according to the present invention, a synthetic or natural fiber containing no cyano groups is brought into contact with an aqueous bath containing monovalent copper ions and thiosulfate ions, and copper sulfide is added to the fibers. A method for producing conductive fibers is provided, which comprises bonding the conductive fibers.

In the present invention, first, polyamide fibers,
Reaction with dicyandiamide, graft polymerization with acrylonitrile, cyanoethylation reaction, mixed spinning method, graft polymer spinning method on non-cyano synthetic or natural fibers such as polyester fibers, rayon fibers, Kyupra fibers, animal fibers, or vegetable fibers. The fibers to be treated are those into which cyano groups have been introduced using a known method such as block polymer spinning.

The method of the present invention is a one-step method, and the treatment can be completed in one treatment bath. Therefore, in the case of the present invention, product productivity is significantly improved.

In the present invention, fibers as raw materials to be treated are brought into contact with an aqueous bath containing monovalent copper ions and thiosulfate ions (S ₂ O ₃ ^-- ) to bond copper sulfide onto the fibers. As mentioned above, cyano groups in fibers have a strong affinity for monovalent copper ions, so
It is thought that the valent copper ions are selectively adsorbed onto the cyano groups and react with the thiosulfate ions in this state, thereby bonding copper sulfide onto the fibers.

The aqueous bath used in the present invention may contain monovalent copper ions and thiosulfate ions, and the source of the thiosulfate ions is not particularly limited.

In the present invention, cyano groups on the fibers provide conditions that promote the copper sulfide forming reaction between monovalent copper ions and thiosulfate ions. That is, dissolved monovalent copper ions and thiosulfate ions that have not reacted in the aqueous bath react on this cyano group and bond to the fibers as copper sulfide, thereby imparting conductivity to the fibers. be done. 1 that coexists in a dissolved state in an aqueous bath
It is an unexpected fact discovered by the present inventors that copper valence ions and thiosulfate ions react specifically on the cyano group to form copper sulfide.

In the aqueous bath used in the present invention, as the monovalent copper ion source, a monovalent copper salt itself may be used, or a combination of a divalent copper salt and a reducing agent may be used. In this combination of divalent copper salt and reducing agent,
Divalent copper ions are reduced to monovalent copper ions by the action of the reducing agent. In this case, examples of divalent copper salts include cupric sulfate, cupric chloride, and cupric nitrate.
Copper or the like is used, and any reducing agent that can reduce divalent copper ions to monovalent copper ions can be used, such as metallic copper, hydroxylamine sulfate, ferrous sulfate, etc. , ammonium vanadate, furfural, sodium hypophosphite, glucose, etc. are used, and sulfur compounds such as thiosulfate, sodium pyrosulfite, and acidic sodium sulfite can also be used because they have reducing properties. Moreover, as the monovalent copper salt, cuprous chloride, its ammonium complex salt, etc. are used.

As the thiosulfate ion source used in the present invention, thiosulfates such as sodium thiosulfate and potassium thiosulfate are preferably used, but any source can be used as long as it can generate thiosulfate ions in an aqueous bath. I can do it. For example, when a dithionite aqueous solution is left for a long time, an aqueous solution containing thiosulfate ions is obtained due to the decomposition of the dithionite; however, in the present invention, such an aqueous solution containing thiosulfate ions can also be used. . Furthermore, as exemplified as the reducing agent above, this thiosulfate ion also acts as a reducing agent for divalent copper ions, so this thiosulfate ion can also be used as a reducing agent.

Furthermore, in the present invention, an acid or a salt is used as a PH regulator to adjust the PH of the aqueous bath, if necessary. Examples of such PH regulators include sulfuric acid, hydrochloric acid, phosphoric acid, etc. Inorganic acids and organic acids such as citric acid and acetic acid, or salts thereof or combinations of acids and salts, such as a combination of citric acid and disodium phosphate, can be used. this
By using a PH modifier, the rate of binding (reaction rate) of copper sulfide from the aqueous bath to the fiber surface can be controlled.

Regarding the treatment temperature in the present invention, the higher the temperature, the more quickly the reaction proceeds, but higher temperatures may reduce the strength of the fibers, while lower temperatures require more time for the reaction, so there is an appropriate temperature range. That is, approximately 30
A suitable temperature range is from 120°C to 120°C, preferably from 40 to 100°C.

Next, the higher the content of copper sulfide in the fiber, the better the conductivity of the fiber will be, but on the other hand, the other physical properties of the fiber will deteriorate, and if it is too low, sufficient conductivity will not be obtained. Therefore, the appropriate content thereof is 1% to 30% by weight based on the weight of the fiber. When the conductive fiber thus obtained was analyzed by X-ray analysis, it was found that the diffraction lines (planar spacing: _1.97 Å, _3.21 Å, 2.79 ) was observed, and it was revealed that it was contained in the fiber as copper sulfide.

According to the present invention, excellent conductivity can be imparted to various synthetic fibers or natural fibers such as polyamide fibers, polyester fibers, rayon fibers, Kyupra fibers, animal fibers, or vegetable fibers. The resulting conductive fibers have good washing resistance and maintain the texture and physical properties of the original fibers with almost no loss. Therefore, the conductive fiber obtained by the present invention can be used alone, blended with other non-conductive fibers, etc., or mixed with various knitted fabrics to impart an excellent antistatic effect to these fibers. ,
It is useful in an extremely wide range of fields. For example, synthetic fibers, especially polyamide fibers and polyester fibers, are easily charged and cause discomfort when used in clothing or carpets, but this problem can be solved by using this conductive fiber. be able to.

The conductive fiber of the present invention and the method for producing the same will be explained in detail by giving examples below.

Example 1 Nylon staple (3 denier, cut length
76mm, manufactured by Toray Industries, Inc.) was washed with warm water at 50°C to remove the oil, and then 50% by weight of acrylonitrile, 1.2% by weight of ammonium persulfate, and 3% by weight of hydrogen sulfite were added to the weight of the nylon staple. Place it in an aqueous solution containing sodium at a bath ratio of 1:20,
The temperature was gradually raised from room temperature and treated at 70°C for 60 minutes. After thorough washing with hot water and water to sufficiently remove unreacted substances, side-reacted substances, catalysts, etc., analysis revealed that the introduction of acrylonitrile into the nylon fiber was 10%. Next, the washed nylon staple was treated with 10% by weight of cupric sulfate based on the fiber weight.
The sample was placed in an aqueous solution containing 10% by weight of sodium thiosulfate and 5% by weight of sodium bisulfite at a bath ratio of 1:20, and the temperature was gradually raised from room temperature to 100°C for 60 minutes. Wash thoroughly with water and dry.

X-ray analysis of the nylon fibers obtained in this way revealed that the diffraction lines ( _planar spacing: _1.97 Å,
3.21 Å, 2.79 Å), and therefore, it became clear that copper ions were dispersed and adsorbed on the nylon fibers as copper sulfide. Next, when the electrical resistivity value of this olive gray nylon fiber was measured, it was 4×10 ^-1 Ω·cm, and the content of copper sulfide in the fiber was 3.5%.

In addition, in the above, the nylon staple treated with cyano group introduction was added to 20% of the fiber weight.
The same procedure was followed except that the treatment was carried out at 40°C for 10 hours in an aqueous solution containing 1:20 bath ratio containing 20% by weight of cupric sulfate, 20% by weight of sodium thiosulfate, and 10% by weight of sodium bisulfite. Upon treatment, the resulting fibers exhibited a specific resistance value of 5.2×10 ⁻² Ω·cm.

Example 2 Polyester fiber (3 denier, cut length 89
mm bias, type T-981, manufactured by Toray Industries, Inc.), after thoroughly washing it, 50% by weight of acrylonitrile, 1% by weight of benzoyl peroxide, and 5% by weight of Neugen SS (emulsifier) based on the weight of the fiber. The sample was placed in a bath with a bath ratio of 1:15 and treated at 105°C for 90 minutes.
It was thoroughly washed with water to remove unreacted substances, side reactants, and catalyst. Next, the washed fibers were placed in a bath containing 10% by weight of cupric sulfate, 10% by weight of sodium thiosulfate, and 10% by weight of hydroxyamine sulfate at a bath ratio of 1:20 based on the weight of the fibers. Then, the temperature was gradually raised from room temperature to 100°C for 60 minutes, and after washing with water, it was thoroughly dried. The polyester fiber obtained by the above treatment exhibits an olive color, and its electrical resistivity value is 3.2.
×10 ^-2 Ω·cm, indicating good conductivity. Moreover, the content of copper sulfide was 3.2%. In addition, 8.2% of acrylonitrile was introduced into the polyester fiber by the above graft polymerization.

Example 3 Rayon staple (2 denier, cut length
51 mm, type KRP, manufactured by Kojin Co., Ltd.) was immersed in a 2% sodium hydroxide aqueous solution at room temperature for 15 minutes, squeezed to a squeezing rate of 100%, and then soaked in a bath containing 50 g/acrylonitrile at a ratio of 1. :20 in the bath, 55
℃ for 90 minutes. After neutralizing the alkali, unreacted substances and side reactants were removed. The cyanoethylation rate in the above reaction was 8%. After this treatment, the fibers were treated with cupric sulfate in an amount of 10% by weight based on the fiber weight.
It was placed in a 1:20 bath containing 10% by weight of sodium thiosulfate and 5% by weight of hydroxyamine sulfate, treated at 80°C for 90 minutes, then washed with water and dried. The obtained fiber exhibited an electrical resistivity value of 1.0 Ω·cm, and the content of copper sulfide was 2.8%.

Similar results were observed when Cuypra fiber was used instead of the rayon staple.

Example 4 An aqueous solution containing 50 g of dicyandiamide and 300 g of formalin (30% formaldehyde aqueous solution) was adjusted to pH 10 with sodium carbonate, and then
The methylolation reaction was carried out at ℃ for 3 hours. After cooling,
Reactants 100g/and ammonium chloride 10
Cotton, which had been previously treated at 100℃ for 60 minutes in a bath containing 10g of sodium hydroxide, was soaked at room temperature, then squeezed to a squeezing rate of 90%, and then heated to 80℃. It was pre-dried and then heat treated at 180°C for 3 minutes. The cotton treated as described above is placed in a bath containing 15% by weight of cupric sulfate, 10% by weight of sodium thiosulfate and 10% by weight of sodium hydrogen sulfite in a bath ratio of 1:20, based on the weight of the fiber; Gradually raise the temperature from room temperature and treat at 80℃ for 90 minutes.
It was then washed with water and dried. The obtained cotton fibers had a khaki color and exhibited good electrical conductivity with an electrical resistivity value of 3.6 Ω·cm. In addition, the content of copper sulfide is
It was 2.5%.

Comparative Example 1 To obtain a treatment bath, sodium dithionite was added to an aqueous solution containing 10% by weight of cupric sulfate and 5% by weight of sodium bisulfite.
Precipitation of copper sulfide occurred, and this treatment bath had no practical value as a treatment bath for producing conductive fibers.

Claims (1)

[Scope of Claims] 1. A conductive fiber comprising a synthetic or natural fiber containing no cyano groups and containing copper sulfide via the cyano groups. . 2. Copper sulfide is bonded to the synthetic or natural fiber that does not contain cyano groups by contacting the fiber with an aqueous solution bath containing monovalent copper ions and thiosulfate ions. A method for manufacturing conductive fibers.