Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06Q—DECORATING TEXTILES
  • D06Q1/00—Decorating textiles
  • D06Q1/04—Decorating textiles by metallising

Definitions

• This invention relates generally to the manufacture of fibrous mixtures having superior antistatic characteristics; it concerns more specifically the manufacture of fibrous mixtures containing metallized or chemically metal-deposited fibers acting as antistatic components for said mixture substantially composed of water-repellent fibers, especially thermoplastic and synthetic fibers.
• fibrous mixture used herein throughout the specification includes fiber mixture; blended fibers; mixedly spun fibers; mixed filaments bundle; conjugate composite fiber, mixed yarn bundle; mixed fiber thread or threads; and woven and knitted fabrics.
• a highly effective metal coating is realized on a chemical fiber, preferably a thermoplastic fiber, when it is sensitized and activated by deposition on its surface of a noble metal catalyst, dried, subjected to a fiber-improving after-treatment such as oiling, stretching, shrinking or dyeing or the like; and then degreasing and chemically metal-depositing.
• a fiber-improving after-treatment such as oiling, stretching, shrinking or dyeing or the like
• the above process can effectively be applied to various kinds of chemical fibers including those of acetate, triacetate, cuprammonium rayon, polyamide, polyester, polyvinyl, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polyolefin, polyurethane and their copolymers, of which acrylonitrile synthetic fibers and then those of polyvinyl chloride, polyvinylidene chloride or the like are highly effective for the desired purpose on account of the provision of a highly tight and durable metal deposit.
• the acrylonitrile fiber has in its molecular structure at least a high polarizing group, such as CN and the like radicals and that the fiber surface represents a fine fibril structure, in addition to the very presence of fine surface undulations which are formed in the course of its dryor wet-spinning process, whereby the acrylonitrile series synthetic fibers are generally manufactured, said undulations being found highly effective for anchoring of the catalyst.
• a high polarizing group such as CN and the like radicals
• silver; copper; nickel; cobalt; tin; palladium and the like may be used, of which nickel and copper are highly recommendable. This may be at tributed to a strong autocatalytic performance possessed by these metals.
• the resulting superior metallized fibers capable of obviating the aforementioned various conventional drawbacks can be, as ascertained by our profound practical experiments, processed without substantial loss of the now realized favorable performances in the field of fiber improving after-treatment whereby the fibers are subjected, as is well known, to a considerable mechanical and thermal deformation to such a degree that the deposit of the coated metal layer on the fiber proper would be substantially loosened.
• the term mechanical and thermal deformation as used throughout this specification is intended to include stretching, bending, twisting, frictional slippage or the like in or among fibers, or any combination thereof.
• the chemical deposition of metal or metallization of fibers employed as a step of the process according to this invention is realized substantially by depositing a selected metal on the fibers through the Way of a reducing separation. Therefore, the metallic coating thus produced has a strong tendency of reducing activity.
• a fibrous mixture containing an amount of such metallized fibers is dyed in a conventional way, uneveness of the dyed color tone could be invited on account of practical discoloration and/ or fading of the dyestufi.
• the process is carried out in such a way that the fibers are at first subjected to sensibilization and activation, and then the thus resulted raw fibers activated are mixed with plain or non-processed fibers, dyed and chemically metal-deposited.
• a fiber mixture including metal-coated fibers and representing a superior color tone without any appreciable degree of discoloration and/or fading appearing in and after the dyeing step can be provided.
• the fiber is generally processed in such a way that upon thermo-slackened it is subjected to a stretching of 1.1-1.5 times at a high temperature in the order of 100- 150 C. by means of boiling water, dry heating, turbo stapler or the like, into a high shrinkable fibrous stock having 540% shrinkability which stock is then mixed with a low shrinkable fiber mass, and the resulting mixture is caused to shrink during the next succeeding step of dyeing or heat treatment, for developing the latent bulkiness into its apparent form.
• a high shrinkable fiber mass is manufactured in such a way the fibers are subjected to thermo-slackening; degreased; sensitized and activated, and then thermally stretched to a degree of about 1.1-1.5
• the fibers are so processed that upon being subjected to a thermal slackening, they are thermally stretched to about 1.1-1.5 times elongation; degreased; sensibilized and activated, so as to provide a similar high shrinkable fiber mass.
• the thus processed fiber mass is admixed evenly with a similar high shrinkable fiber mass which has not been, however, activated, yet having the same latent shrinkability of about 540%.
• This mixture is further admixed evenly with a still further fiber mass, having a substantially less shrinkability than that above specified and formed into yarns through spinning.
• These mixed-fiber yarns are subjected to a dyeing or a heat treating step, for developing the latent bulkiness, and finally treated in a chemical bath adapted for performing the metal depositing step.
• the activated, high shrinkable fiber components of the overall fiber mass only are formed with metallized coatings. In this case, the final mass or yarns represent a satisfactory bulkiness.
• the products prepared by the aforementioned preferable mode of the process represent an evenly mixed state; substantially no discoloring and fading of the above defective kind; a superior dyeing performance; an improved coverage of the metallic coating layer; as well as a superior hand feeling.
• the yarn When it is intended to provide a textile product with a superior antistatic performance under the utilization of yarns including said kind of metallized fibers, the yarn should preferably contain them in such a mixing ratio which is higher than that assuring a continuity of said fibers when seen from the point of its theoretical probability.
• the metallized fibers When the metallized fibers are utilized in the form of their filaments or alternatively of mixed filaments, they are frequently processed into textured yarns. For this purpose, it would be conceivable to process the metallized fibers prepared by the prior proposed technique and the textured and metallized yarns thus realized could be further processed through weaving or knitting into a final textile product. In this case, however, the metallized fibers must be subjected to a severe physical treatment such as strong twisting, edging or the like, so that part of the metallic coatings will frequently be scaled-off from the fibers to lesser or greater degree. Even if such phenomenon should not be invited, the tightness of the coating will become loosened under most circumstances.
• the thus partially processed filaments are dried, wound-up and mixed with a similar or different kind of plain or non-processed filaments and either in the state of filaments, or in the course of twisting the yarns prepared therefrom.
• the thus prepared m xedfiber multifilaments are then subjected to a conventional texturing step and then, preferably upon degreasing and dyeing, to the metal-depositing chemical step. In this way, the preactivated filament components only are metalcoated and contained in the textured yarns.
• These textured yarns may be further processed mto final textile products by weaving, knitting or the l1ke conventional finishing technique.
• the textured and activated yarns or textured yarns includmg activated filaments are fabricated into final products by weaving, knitting or like procedures. Then, these final products are subjected to a treatment in a metal-depositing bath for attaining the desired effect upon the preactlvated fibrous constituents only. It has been ascertained through practical experiments that the chemically deposited metal layer has an even coverage and a satisfactory depositing power.
• the textured fabrics thus finished have a superior covering power, an efiicient hand feeling and stretchabrhty, as well as a favorable permanent antistatic characteristic which is provided by the very existence of practically continuous metal-coated filaments in place of short length fibers admixed to plain or non-metallized fibers or filaments as in the case of prior technique.
• the textured yarns including metallized fibers or filaments must not be contained 100% or so. Accordmgto our experiments, it is sufficient to set the fiber mixing ratio to at least 0.01 wt. percent, preferably at least 0.1 wt. percent, for obtaining suflicient antistatic performance.
• Thickness of the metal coating layer should be 0.01-l micron, preferably, 0.02.5-025 micron.
• the thickness is less than 0.01 micron, the desired metallic appearance cannot practically be obtained, in additlon to the produced uneven metallic coating which has been realized only with substantial difiiculty in the control of the processing conditions.
• coating thickness greater than one micron, the inherent physical properties of thermoplastic fibers will become rather considerably unfavorable and thus should be avoided.
• the thickness of the metal coating on the fiber or filament to be used for the stretch yarn should preferably be less than 0.25 micron, since this kind of yarn may have a stretch or the rate of crimp elongation rate amounting to as high as 400%. With the stretch fabrics made of this kind of yarns, the rate may amount to 15-70%. The rate of stretch of the stretch knitted fabrics will be still larger.
• the fibrous material is immersed in a bath solution containing a noble metal for adsorbing the latter, and then the fibrous material is treated in a reducing base so as to reduce the adsorbed noble metal which is deposited thereby on the surface of the fibrous material and in the form of the desired catalyst.
• the noble metal catalyst may be Ag, Pt, Pd, Au or the like.
• the reducing agent may be stannous chloride, hypophosphorous acid, hydrazine chloride, hydroquinone or the like.
• the chemical coating bath may contain metal salt, reducing agent, main or auxiliary accelerator additive, pH- modifier and the like.
• the metallizing metal may be silver, copper, nickel, cobalt, zinc, chrominum, tin, gold, palladium or the like.
• copper, nickel and tin are suitable for the desired purpose, especially when considering the tightness, even stabilization, operating ease and the like of the produced metallizing coating.
• the chem1cal bath adapted for nickel coating may contain nickel ions derived from the chloride, sulphate or the like, or a combination thereof.
• hypophosphite such as sodium hypophosphite, calcium hypophosphite or the like may effectively be utilized.
• Hypohydrosulphite ions may be employed for the desired purpose.
• hypophosphite When a hypophosphite is used as the reducing agent, carboxyhc acid such as propionic acid, succinic acid or the like, or amino-carboxylic acid can be used as the main or auxiliary accelerator.
• carboxyhc acid such as propionic acid, succinic acid or the like
• amino-carboxylic acid As the complexing agent, hydroxycarboxylic acid such as tartaric acid, glycolic acid, lactic acid, citric acid or the like may be used.
• a most representative chemical bath adapted for the metal-depositing purpose comprises hypophosphite as the reducing agent; succinic acid as the accelerator; and acetic acid or sodium acetate as the buffer.
• fiber mass (A) a mass of the activated fibers
• Nickel chloride g 20 Sodium hypophosphite g 27 Sodium succinate g 20 pH Temp. C 96 Bath ratio was 1:24; V/ A ratio (bath volume/surface area of the treated fiber mass) was 1/50.
• the mean thickness of the nickel coatings amounted 0.065 micron.
• the thus nickel-deposited fibers were washed; dehydrated; dried up; and oiled and then mixedly spun at mixing ratios of 1% and 5%, respectively, with a mass of same kind of acrylonitrile fibers, each being again of 6 d., to provide 2/24 nm. of spun yarns.
• This product is called spun yarn (B) herein.
• the activated fiber mass (A) was without being chemically metal-deposited, mixedly spun at mixing ratios of 1% and 5%, respectively, with a mass of same kind of acrylonitrile fibers, each being again 6 d., to produce 2/ 24 nm. of spun yarns.
• This product is called spun yarn (C) herein.
• Said spun yarns (B) and (C) were dyed with Kayalon Fast Red R, manufactured and sold by a Japanese firm, Hodogaya Chemical Co., Ltd., Hodogaya, near Yokohama, Japan and believed to be under the following treating conditions:
• EXAMPLE 2 A tow of 3 d.-acrylic synthetic fibers was treated in a turbo-stapler at 140 C. with 1.25 times elongation, to provide a sliver. This sliver was immersed in a sensibilizing bath containing '10 g. of stannous chloride, 400 cc. of hydrochloric acid and 1,000 cc. of water, for 5 minutes. Then, the fibrous material thus treated was washed sufficiently with water; immersed in an activating bath containing 0.5 g. of palladium chloride, 5 cc. of hydrochloric acid and water 6,000 cc. for 5 minutes; washed with water; oiled and dried up.
• This activated and high-shrunk fiber mass was admixed with similar 3 d.- acrylic high contracted and at a mixing ratio of 10% so as to provide a sliver.
• This sliver was mixed with 3 d.- low-shrunk sliver on a mixing gill in such a manner that the content of the activated, high-shrunk fiber component amounted to 5%. From this, spun yarns, 2/4'8 nm., were prepared.
• EXAMPLE 3 A tow of 6 d.-acrylic fibers was subjected to a thermal shrinking step and then subjected to an elongation of 1.3 times length in a boiling water. These fiber filaments were cut into a mean length of 76 mm. These cut fibers were activated in the same manner as in the foregoing Example 2, so as to provide activated and highshrinking acrylic fibers which were then mixed with similar fibers prepared in the similar way, but not activated, at a mixing ratio of 6% of the former. This high-shrinking sliver was mixed at a ratio of 1:1 with a corresponding, yet low-shrinking tow in a mixing gill, so as to provide filaments, each d., 1/ 24 nm.
• the necessary mixing ratio for attaining a theoretical continuity of the nickel-coated fibers may be:
• a mixed-fiber knitted product composed of said both kinds bulky yarns with a mixing ratio of 1:3 and containing about 1% of nickel-deposited fibers represented a surface electrical resistancez4 ohms.
• the antistatic characteristics and dyed color tone were highly superior.
• the surface electrical resistance was measured at -22 C. with RH:65%.
• Honest-Meter was manufactured and sold by a Japanese firm: Shishido Shokai. Applied voltage was +10 kv. for 30 seconds. The initial voltage of the yarns containing none of metal-deposited fibers amounted to 38 mv.
• these filaments were spun, dried, twisted and wound up. Then, these filaments were passed through several steps of degreasing, water-washing, sensibilizing, second water-washing, activating, third water-washing and drying and then wound up again on a bobbin.
• the sensibilizing bath comprises 10 g. of stannous chloride, 40 cc. of'hydrochloric acid and 1,000 cc. of water, while the activating bath contained:5 g. of palladium chloride, 5 cc. of hydrochloric acid and 6,000 cc. of water, being adapted for one pass operation for both cases.
• Mlx ratio 1%, V 45 38 6 360 450 268 Blank including no metallized fibers 81 59 9 840 1, 080 910 1 Friction element: calfskin, RH 456, 30 0.; measuring instrument: rotary static tester.
• EXAMPLE 6 66 nylon-multifilaments, 11 d./ 5 f., were spun, stretched, twisted and once wound up on a bobbin. Then, it was passed successively and continuously through several baths of degreasing, Water-washing, sensibilizing, water-washing and drying, and once again wound up. The compositions of the sensibilizing and activating were same as in the foregoing Example 1. Duration of pass was adjusted to 3 minutes.
• the thus activated nylon multifilaments were mixed with plain or non-activated nylon multifilaments to such of fibrous mixture, 70 d./ 32 f. This mixture so treated was subjected to a stulfer step and then wound up.
• Main components of the copper-depositing composition above-mentioned are believed to include copper sulfate, Formalin and sodium sulfate, added with small amounts of caustic soda and sodium carbonate.
• This dyed fiber mixture was then immersed in a golddepositing chemical bath containing per lit. silver nitrate 22.2 g.; 25%-ammonia aqua-solution 30 ml.; 37%-Formalin 2.5 ml.; degradation inhibitor composition including sodium sulfate and ethyl alcohol, at normal temperature for about 5 minutes.
• the resulting products had an eflicient conductivity as a whole, and the well-developed color tone was of saxe blue.
• Surface electric resistance amounted to 6.5 l ohms.
• Initial voltage on Honest- Tester amounted to 20.5 mv., 20 C., RH 25%. This was then dehydrated at 20 C., RH 40%. Antistatic performance was superior. No sparks or discharge noises were encountered while undressing (underwear was made of cotton).
• a process for the manufacture of a fibrous mixture having superior antistatic characteristics comprising the steps of (l) subjecting a fibrous material to deposition of a noble metal catalyst on the surface of said fibrous material, thereby sensitizing, conditioning and activating said surface,
• said metal catalyst is selected from the group consisting of platinum, palladium, gold and silver.
• said deposition of said noble metal catalyst comprises depositing a noble metal on said fibrous material by reducing a salt of said noble metal.
• said reducing agent is selected from the group consisting of stannous chloride, hypophosphorus acid, an alkali metal hypophosphite, an alkaline earth metal hypophosphite, hydrazine hydrochloride, and hydroquinone.
• said fibrous material is a fiber selected from the group consisting of the acetates, triacetates, cuprammonium rayons, polyamides, polyesters, polyvinyls, polyacrylonitriles, polyvinyl chlorides, polyvinylidene chlorides, polyolefins, polyurethanes, and copolymers thereof.
• said fiber is selected from the group consisting of polyvinyl chlorides, polyvinylidene chlorides, and polyacrylonitrile.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Chemically Coating (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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Publications (1)

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Cited By (12)

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• 1969
  • 1969-10-23 US US868889A patent/US3686019A/en not_active Expired - Lifetime
  • 1969-10-24 GB GB52351/69A patent/GB1247090A/en not_active Expired
  • 1969-10-24 FR FR696936603A patent/FR2021502B1/fr not_active Expired

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