JP4329105B2 - Metal-coated fiber body and method for producing the same - Google Patents

Description

  The present invention relates to a metal body provided with a metal coating on a high-strength nylon fiber body, and relates to a metal-coated fiber body excellent in adhesion of the metal coating and excellent in durability under heating, and a method for producing the same.

Conventionally known are conductive fibers or yarns in which a metal thin film is coated on the surface of a synthetic fiber made of a polymer material such as nylon fiber or polyester fiber, and various methods are available for improving the adhesion of the metal coating film. Has been tried. For example, when coating copper sulfide, a method of pre-treating a polymer material with a dye having a copper ion-trapping group, and then sulfiding after binding copper ions to this (Japanese Patent Publication No. 01-37513) or alkali treatment A method of attaching a copper ion capturing group to a roughened fiber surface and bonding copper sulfide to the copper ion capturing group is known (Japanese Patent Laid-Open No. 06-298973). For materials that are difficult to be metal-plated, such as aramid fiber, a method of forming metal plating by attaching metal ions using polyvinylpyrrolidone (PVP) and reducing the metal ions (JP-A 06-506267) No.) is known.
Japanese Patent Publication No. 01-037513 JP 06-298773 A Special table 06-506267

  However, the plating method using PVP is not general because the types of fibers are limited. Further, the coating method for introducing a copper ion capturing group has a problem that the metal coating is limited to copper or a compound thereof and the strength of the metal coating is not always sufficient. Note that if the fiber is roughened by alkali treatment, the adhesion strength of the metal coating can be generally increased, but sufficient effects cannot be obtained unless the degree of roughening and the state of the metal coating are appropriate. Moreover, when the metal-coated fiber is used for clothing or the like, it is necessary to withstand severe use conditions such as washing and wear. Further, from the viewpoint of electrical conductivity, the metal coating is required to have a highly reliable adhesion strength because a disconnection state is also caused by partial peeling of the metal coating.

  The inventors of the present invention applied heat treatment to a fiber body having a metal coating to prepare the structure of the fiber body. Specifically, for example, if the fiber body is heat-treated and crystallized, the coating strength of the metal coating is increased. I found a dramatic improvement. Further, it has been found that by gradually raising the temperature and cooling in this heat treatment, the strength of the metal coating is further improved and the durability is enhanced, and the expansion / contraction rate of the fiber body is significantly reduced. The present invention applies this finding to a high-strength nylon fiber body as a fiber body.

The present invention relates to a metal-coated fiber body having the following configuration.
(1) A high-strength nylon fiber body is provided with a metal coating, and is heat-treated at a temperature in the range of 400 to 500 ° C. that is higher than the crystallization temperature of the fiber body and lower than the melting temperature. Metal-coated fibrous body to be used.

The metal-coated fiber body of the present invention includes the following aspects.
(2) The metal-coated fiber body according to the above (1), which has a stretch rate of ± 4% or less at a temperature not lower than the crystallization temperature of the fiber body and lower than the melting temperature.
(3) The above stretching ratio of ± 2% or less with respect to g load corresponding to 1 / 100th of the fiber body diameter (denier value) at a temperature not lower than the crystallization temperature of the fiber body and lower than the melting temperature ( The metal-coated fiber body according to 1) or (2).
(4) The metal-coated fiber body according to any one of (1) to (3) above, wherein an electrical resistance per denier is 1 Ω / cm · denier or less per 1 cm of the fiber body.
(5) The metal-coated fiber body according to any one of (1) to (4) above, wherein the metal coating has a reference strength of grade 4 or higher in the coating peeling test.
(6) The metal-coated fiber body according to any one of claims 1 to 5, wherein the fiber body is a short fiber, a long fiber, or various yarns composed of these fibers.
(7) The metal coating according to any one of (1) to (6) above, wherein the metal coating is a conductive metal made of silver, gold, platinum, copper, nickel, tin, zinc, palladium, or a mixture or alloy thereof. Fiber body.
(8) A mixed fiber body obtained by blending at least one of the metal-coated fiber bodies according to any one of (1) to (7) above into synthetic fibers, natural fibers, or mixed fibers of synthetic fibers and natural fibers.
(9) A woven fabric or a non-woven fabric comprising the metal-coated fibrous body according to any one of (1) to (8) above.
(10) An electric wire substitute material comprising the metal-coated fiber body according to any one of (1) to (9) above.

The present invention includes a method for producing a metal-coated fiber body having the following configuration.
(11) A metal characterized by providing a high-strength nylon fiber body with a metal coating and heat-treating at a temperature not lower than the melting temperature and higher than the crystallization temperature of the fiber body in a temperature range of 400 to 500 ° C. A method for producing a coated fiber body.
The manufacturing method of the metal coating fiber body of this invention includes the following aspects.
(12) The process according to (11), wherein the temperature is raised at a rate of 0.1 to 10 ° C. per minute, and the raised temperature is maintained for 5 to 200 minutes.
(13) The method according to (12), wherein the temperature is raised and then gradually cooled to room temperature at a rate of 0.1 to 10 ° C. per minute.
(14) The method according to any one of (11) to (13) above, wherein the heating and cooling treatment is carried out under pressurized steam or in an electric furnace under an inert atmosphere of nitrogen gas or argon gas.

  The metal-coated fiber body of the present invention has an excellent coating strength, and specifically, it can have a reference strength of 4 grades or more in a coating peel strength test. In addition, the stretch rate is small even under heating, and the durability against external force is excellent. Therefore, the metal-coated fiber body of the present invention can also be used in a field that could not be applied conventionally because the adhesion and durability of the metal coating are not sufficient. In addition, the metal-coated fiber body of the present invention can be easily produced because it is obtained by applying a heat annealing process at a specific temperature after providing a metal coating.

Hereinafter, the present invention will be described in detail based on embodiments.
[Metal-coated fiber body]
The metal-coated fiber body of the present invention is provided with a metal coating on a high-strength nylon-based fiber body, and heat-treated at a temperature in the temperature range of 200 to 500 ° C. that is higher than the crystallization temperature of the fiber body and lower than the melting temperature. It is characterized by.
In the present invention, the fiber body refers to short fibers (staples), long fibers (filaments), and various processed yarns (filament yarns, spun yarns, etc.) made of these fibers, and these are also referred to as fiber bodies. . The high-strength nylon fiber body is a highly polymerized nylon fiber body marketed under the trade name “Zylon”. In addition, the fiber etc. which consist of other engineering plastics can also be used.

In general, when synthetic fibers such as polyester, nylon, and polyacryl are heated, the state gradually changes depending on the heating temperature, such as glass transition, crystallization, and melting (melting). It shrinks greatly at the crystallization stage. In the present invention, the metal-coated fiber body using a high-strength nylon-based fiber body as the fiber body is subjected to such heat treatment to increase the adhesion strength of the metal coating.

That is, the metal coated body made of a high-strength nylon-based fibrous body is heated to a temperature higher than the crystallization temperature of the fibrous body in a temperature range of 200 to 500 ° C. , preferably 400 to 500 ° C. , to soften the fibrous body surface. The surface of the softened fiber body enters fine irregularities on the contact surface with the metal coating, and the adhesion between the metal coating and the fiber body is improved by the anchor effect.

  The high-strength nylon fiber body used in the present invention has higher heat resistance than other synthetic fibers, has a melting temperature slightly below 700 ° C., and is high in strength, and therefore has a high temperature of about 500 ° C. to 600 ° C. It can also be used in an environment. If the heating temperature is less than 100 ° C., a sufficient heat treatment effect cannot be obtained. On the other hand, if the heating temperature exceeds 700 ° C., the fibrous body is melted, which is not preferable.

  This heat treatment is preferably performed at a rate of 0.1 to 10 ° C. per minute, and the elevated temperature is preferably maintained for 5 to 200 minutes. If the heating rate is lower than 0.1 ° C./min, it takes a long time, and if it is higher than 10 ° C./min, the metal coating tends to peel off, which is not preferable. In addition, if it heats higher than the melting temperature of a fiber body, the whole fiber body will melt | dissolve and crystallinity will fall, and it will become impossible to hold | maintain a metal coating by destroying a fiber body.

  The adhesion (coating) strength of the metal coating can be further increased by slowly cooling to room temperature at a constant rate after this heat treatment. That is, after the heat treatment of the metal-coated fiber body, the fiber body and the metal coating are integrally cooled in a state where the adhesion between the metal cover and the fiber body is enhanced, so that the contact surface between the fiber body and the metal cover in the cooling process is Peeling is prevented and the adhesion strength of the metal coating is further improved. Further, by performing appropriate slow cooling, even if the metal-coated fiber body is subsequently heated, it hardly shrinks, and the expansion / contraction rate is greatly reduced.

  The slow cooling rate is, for example, suitably from 0.1 to 10 ° C. per minute, preferably from 0.1 to 5 ° C. per minute, more preferably from 0.2 to 2 ° C. Good to do. It should be noted that if the slow cooling rate is less than 0.1 ° C./min, the treatment time becomes longer, and if it is greater than 10 ° C./min, the cooling rate is too fast and the recrystallization of the fiber body becomes insufficient, which is not preferable. .

  The heat treatment means may be heating by infrared rays in addition to a heating furnace, a hot air furnace or the like. Moreover, the heat processing by the pressurized water vapor | steam in a plating tank may be sufficient. The heat treatment atmosphere may be air, but in order to prevent discoloration due to oxidation of the metal coating, heat treatment is preferably performed in an inert gas atmosphere such as nitrogen or argon.

  As described above, in the metal-coated fiber body of the present invention, as a first step, the metal-coated fiber body is heated to a temperature higher than the crystallization temperature of the fiber body to promote recrystallization of the fiber body, and this temperature is maintained for a certain period of time. After the surface of the fibrous body softened by the metal coating is sufficiently penetrated to eliminate the gap and improve the adhesion, preferably, when cooling from the set temperature to room temperature as the second stage, Sufficient slow cooling prevents local delamination between the recrystallized fiber body and the metal coating during cooling shrinkage, greatly increases the coating strength of the metal coating on the fiber body, and greatly increases the stretchability of the fiber body To suppress.

  The metal-coated fiber body of the present invention has excellent coating strength and non-stretchability by such heating and cooling treatment. In other words, as mentioned above, synthetic fibers generally change their crystal structure when heated to a temperature higher than the crystallization temperature and may cause heat shrinkage of 10% or more. In the case where the crystal structure of the fibrous body is adjusted, the crystal structure hardly changes even when heated thereafter, and hardly causes thermal contraction. Rather, in some cases, it tends to exhibit a slight elongation.

  Specifically, for example, a metal-coated fiber body having a stretch rate of ± 4% or less, preferably ± 3% or less when no load is applied, at a temperature higher than the crystallization temperature of the fiber body and lower than the melting temperature. Can be obtained. Further, even when a load is applied under this heating, for example, g corresponding to 1 / 100th of the diameter (denier value) of the fiber body at a temperature higher than the crystallization temperature of the fiber body and lower than the melting temperature. It is possible to obtain a metal-coated fiber body having a stretch rate of ± 2% or less, preferably a stretch rate of ± 1.5% or less, more preferably a stretch rate of ± 1% or less with respect to the load. Note that the g load corresponding to 1/100 of the denier value means that a load of 1 g is applied to a 100 denier fiber body, for example.

  In addition, the metal-coated fibrous body of the present invention has a peel strength of 4 or more in the peel strength test based on the standard (JIS L 0849) (simply called a strength of 4 or more) by performing the above heating and cooling treatment. Can have. By the way, the above standard test (JIS L 0849) is a test to show the fastness of dyeing of fiber bodies and fabrics, and the degree of contamination of white fabrics that occurs when a white fabric is layered on a dyed fabric and rubbed a specified number of times under a specified load. To determine the adherence of dyeing. Criteria from grade 1 to grade 5 are set in order of the degree of contamination (in order of low adhesion), and the degree of contamination of grade 5 is the lowest and therefore the adhesion of dyeing is the highest. With respect to the metal-coated fiber body subjected to the heat treatment, the adhesion strength (coating strength) of the metal coating can be similarly determined based on the degree of contamination of the white cloth in this peel test. Before the heat treatment, a metal-coated fiber body having a coating strength of 3 grades or less can be obtained having a high coating strength of 4 grades or more by performing the heating and slow cooling treatment of the present invention.

  The fiber body used in the present invention is a high-strength nylon fiber body, but it may be a blend of other synthetic fibers or natural fibers.

  The kind of the metal coated on the surface of the fiber body is not limited. For example, silver, gold, platinum, copper, nickel, tin, zinc, palladium, and a mixture or alloy thereof can be used. The coating method or means is not limited. The present invention can be widely applied to a fibrous body provided with a metal coating by electrolytic plating, chemical plating, vacuum deposition, or the like. Also, other construction conditions are not limited as long as they do not interfere with the heating and cooling treatment.

  The metal-coated fiber body of the present invention can have good conductivity. Specifically, for example, a conductive fiber body having an electric resistance per denier of 1 000 Ω / cm · denier or less, preferably 1000 Ω / cm · denier or less, more preferably 100 Ω / cm · denier or less per 1 cm of fiber body is obtained. be able to. In addition, by reducing the metal coating amount, a fiber body having an electrical resistance of 100,000 Ω / cm · denier or more can be obtained. In particular, those coated with a white glossy metal such as silver, platinum, nickel, and tin can obtain a conductive fiber body having a high whiteness with a whiteness (L value) of 50 or more. The whiteness is measured by the Lab method based on Hunter's equation.

  The metal-coated fiber body of the present invention can be further subjected to a surface treatment after the heat annealing treatment. As this surface treatment, a reactive surface treatment agent, a surfactant having an affinity for the metal surface, or a rust prevention treatment or oil treatment (oiling) with paraffin or wax can be applied. In addition, this rust prevention treatment can prevent a decrease in whiteness over time and a decrease in adhesion (peeling strength). Moreover, the slipperiness of the fiber body surface improves by performing an oil process.

  This oil treatment improves slipping when the fiber body is processed by a loom or a knitting machine, and thus also protects the adhesion of the metal coating. When the metal-coated fiber body is actually used, it receives physical forces such as friction, shearing force, bending, and the like, and the metal coating is peeled or missing depending on its strength and frequency. The degree thereof is directly based on the adhesion strength between the metal coating and the fibrous body, but by applying the surface treatment, friction, shearing force and the like are buffered, and as a result, peeling of the metal coating is prevented. Further, since the metal surface is generally partially oxidized to have a hydroxyl group, it is preferable to prevent oxidation and prevent rust by surface treatment. The amount of the surface treatment agent used is generally in the range of 0.1 to 20 wt%, although it depends on the type of metal and the conditions of the heating and cooling treatment.

  The metal-coated fiber body of the present invention is used as various yarns such as short fibers and long fibers, or spun yarn and processed yarn. In addition to using the metal-coated fiber alone, it can be used as a synthetic fiber, a natural fiber, or a mixed fiber blended with a synthetic fiber and a natural fiber.

  Furthermore, the metal-coated fiber body of the present invention can be used as a fabric material such as a woven fabric or a non-woven fabric or a knitted material. In this case, those using silver, tin, nickel, etc. have high whiteness, so that they have excellent color developability when dyed and are suitable for textiles and clothing materials. Furthermore, what coated silver etc. can be utilized as an antimicrobial fiber body and antimicrobial clothing.

  Specific examples include antibacterial socks, underwear, outerwear, white robes, bedding, sheets, napkins, gloves, shirts, trousers, carpets, mats, and work clothes. In addition, the metal-coated fiber body of the present invention is not limited to a fabric material or the like, but uses an electroconductive property, such as an electromagnetic shielding material, dust-free clothing or gloves, shoes, covers, work clothes, or an antistatic material such as an electrode or an electric wire. It can be used as an alternative material for reducing the weight. Further, it can be used as a composite conductive material by surface coating on a conductive organic material, a conductive reinforcing material of a fiber reinforced plastic, or the like.

〔Production method〕
The metal-coated fiber body of the present invention can be obtained by providing a metal coating on the surface of a high-strength nylon-based fiber body by electrolytic plating, chemical plating, or the like, heat-treating in the above temperature range, and cooling. When the metal coating is provided, the surface of the fiber body is etched in advance with alkali or the like, and if the surface is roughened, the coated metal enters the rough surface of the fiber body surface and exhibits an anchor effect. preferable.

  When a metal coating is provided on the fiber body (raw yarn), a fixed shaft is provided inside the plating tank for mounting the wound yarn body with the raw yarn in a cheese winding state, and this fixed shaft is formed by a hollow tube material. Then, it is preferable to provide a large number of liquid passage holes on the tube wall so that the plating solution flows out from the inside of the wound body through the fixed shaft. According to such an apparatus configuration, since the plating solution is supplied from the inside of the wound body through the fixed shaft and flows toward the outside of the wound body, the gap between the fiber bodies is pushed outward by the plating solution. Since the plating solution penetrates into the details between the fiber bodies, the metal plating is uniformly formed on the surface of the fiber bodies even in the cheese-wrapped state.

  After the metal coating (plating) is applied, the fiber body is dried and subjected to a heating / cooling treatment within the above temperature range. This heat treatment may be performed by introducing pressurized water vapor into the plating tank. Alternatively, the wound body may be taken out from the plating tank and transferred to an electric furnace or the like for heat treatment. Note that the heat treatment atmosphere may be air, but in order to prevent discoloration due to oxidation of the metal coating, the heat treatment may be performed in an inert atmosphere such as nitrogen or argon.

Hereinafter, the present invention will be specifically described by way of examples. A fiber body composed of high-strength nylon fibers shown in Table 1 is put in a plating tank and subjected to the following (ii) degreasing treatment, (ii) alkali treatment / neutralization treatment, and (iii) activation treatment. ) Electroless plating was performed, and (e) heat treatment was performed.

(A) Degreasing treatment: A 5 wt% solution of a degreasing solution (Ascreen A-220: Okuno Pharmaceutical Co., Ltd.) was circulated in a plating tank at 55 ° C. for 5 minutes, and then thoroughly washed with ion-exchanged water.
(B) Alkaline treatment: After degreasing treatment, 20 wt% sodium hydroxide solution is circulated in the plating tank for 20 minutes at 70 ° C., and after thoroughly washing with ion exchange water, 5 wt% concentrated hydrochloric acid solution is placed in the plating tank at room temperature for 2 minutes. It was circulated.
(C) Activation treatment: After alkali treatment, concentrated hydrochloric acid solution and palladium chloride mixed solution (Catalyst C: Hadano Pharmaceutical Co., Ltd. product) was circulated through the plating bath at room temperature for 3 minutes and then thoroughly washed with ion-exchanged water. . Further, a 10 wt% sulfuric acid solution was circulated through the plating tank at 45 ° C. for 3 minutes for activation.
(D) Plating step: After depositing the catalyst on the surface of the fiber body by the above pretreatment, each metal plating solution is circulated through the plating tank to form a metal coating for gold, silver, nickel and copper shown in Table 1. did.
(E) Heat treatment: The wound body on which the metal coating was formed was placed in an electric furnace and heat-cooled under the temperature conditions shown in Table 1.

  The adhesion (peeling) strength of the coating was measured for these metal-coated fiber bodies. The results are shown in Table 1. Similar test results for those not subjected to heat treatment after metal coating are shown in Table 1 as comparative examples. In addition, what provided the metal coating similarly about the polyphenylene sulfide type fiber, the polycarbonate type fiber, and the aramid fiber was shown as a reference example.

  The adhesion strength was measured based on a peel strength test in accordance with a standard test (JIS L 0849) showing the dyeing fastness of a fiber body or cloth. Specifically, a white cloth is piled on a bundle of metal-coated fibrous bodies of a test sample, a load of 200 g is applied, a reciprocating friction is performed 100 times at a reciprocating speed of 30 times per minute, and the degree of contamination attached to the white cloth is determined. The peel strength (adhesion strength) was determined according to the standards of grades 1 to 5 in descending order of degree of contamination (in order of low adhesion). In addition, conductivity was measured. For electrical conductivity, the electrical resistance between 10 cm of the central part of the fiber body was measured, and the resistance value per 1 denier (Ω / cm · denier) was determined for 1 cm of the 150 denier fiber body. This was determined for the initial electrical resistance and the electrical resistance after 100 frictions. Further, the shrinkage rate (stretch rate) was measured. This shrinkage ratio is the length of expansion and contraction when a load of 1.5 g is applied to the fibrous body at a temperature of 200 ° C. These results are shown in Table 1.

  As shown in the results in Table 1, all of the samples (A1, A2, A3, A4) of the present invention that were heat-treated after metal coating had a peel strength of 4 grades or more, but comparative samples that were not heat-treated (B1, B2, B3) is 3 grades or less, and the coating (peeling) strength of the present invention is remarkably large and has excellent adhesion. Moreover, although there is no difference in initial electrical resistance, the electrical resistance after friction is significantly lower than that of the comparative sample, and has excellent conductivity. Furthermore, the shrinkage rate of the comparative sample shows shrinkage of −1% to −2%, but the shrinkage rate of the fiber body of the present invention is 0% or less, hardly shrinks, and is extremely stable.

Claims (14)

A metal coating characterized by being provided with a metal coating on a high-strength nylon fiber body and heat-treated at a temperature in the temperature range of 400 to 500 ° C. that is higher than the crystallization temperature of the fiber body and lower than the melting temperature. Fiber body fiber body.
The metal-coated fiber body according to claim 1, wherein the stretch ratio at a temperature not lower than the crystallization temperature of the fiber body and lower than the melting temperature is ± 4% or less. The expansion / contraction rate with respect to g load corresponding to 1/100 of the fiber body diameter (denier value) is not more than ± 2% at a temperature not less than the crystallization temperature of the fiber body and less than the melting temperature. Metal-coated fiber body. The metal-coated fiber body according to any one of claims 1 to 3, wherein an electrical resistance per denier per 1 cm of the fiber body is 1000 Ω / cm · denier or less. The metal-coated fiber body according to any one of claims 1 to 4, wherein the metal coating has a reference strength of 4 grades or more in a coating peeling test. The metal-coated fiber body according to any one of claims 1 to 5, wherein the fiber body is a short fiber, a long fiber, or various yarns composed of these fibers. The metal-coated fiber body according to any one of claims 1 to 6, wherein the metal coating is a conductive metal made of silver, gold, platinum, copper, nickel, tin, zinc, baradium, or a mixture or alloy thereof. A mixed fiber body obtained by blending at least one of the metal-coated fiber bodies according to any one of claims 1 to 7 into a synthetic fiber, a natural fiber, or a mixed fiber of a synthetic fiber and a natural fiber. A woven or non-woven fabric comprising the metal-coated fiber body according to any one of claims 1 to 8. The electric wire substitute material which consists of a metal-coated fiber body in any one of Claims 1-9. A metal-coated fiber body, which is provided with a metal coating on a high-strength nylon-based fiber body, and is heat-treated at a temperature not lower than the melting temperature and lower than the melting temperature in the temperature range of 400 to 500 ° C. Manufacturing method.
The manufacturing method of Claim 11 which heats up at a rate of 0.1-10 degreeC in 1 minute, and hold | maintains the heated temperature for 5 minutes-200 minutes.
The method according to claim 12, wherein after the temperature is raised, the solution is gradually cooled to room temperature at a rate of 0.1 to 10 ° C per minute. The production method according to any one of claims 11 to 13, wherein the heating and cooling treatment is performed under pressured steam or in an electric furnace under an inert atmosphere of nitrogen gas or argon gas.