JPH031402B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a dust-free garment used in clean rooms, bio-clean rooms, operating rooms, etc.
More specifically, the present invention relates to dust-free clothing that is made of a fabric with low air permeability and has improved dustproof properties by improving the sealing of the cuffs to reduce dust leakage from the cuffs. <Prior Art> Clothing intended to reduce or prevent dust generation from workers in clean rooms, ie, dust-free garments or sterile garments (hereinafter referred to as dust-free garments), are conventionally known. Dust-free clothing prevents dust and germs (hereinafter referred to as dust generation) from workers in spaces with high air purity or few bacteria (such as clean rooms), and keeps the space highly clean. They are worn to prevent dust from contaminating products, and are used in industries and fields such as electronics, precision, optics, food, biology, medicine, space, and hospitals. However, in recent years, as industry has become more precise,
The level of cleanliness required for clean rooms is becoming extremely high. For example, in the field of electronics, especially semiconductors, the degree of integration of semiconductor devices is increasing year by year, and currently 64 to 256K bits,
It is expected to reach 1 megabit in a few years. The level of cleanliness in clean rooms in such places needs to be much higher than it currently is. On the other hand, the biggest source of dust in a clean room is a human being, ie, a worker wearing dust-free clothing, and most of the generated dust is generated from the human body or underwear inside the dust-free clothing. Therefore, in order to maintain a high degree of cleanliness in a clean room and to prevent contamination of products, it is necessary to reduce the amount of dust generated by workers.
However, with conventional dust-free clothing, little consideration has been given to the generation of dust from the cuffs of the dust-free clothing, so the dust generated by workers has a significant impact on cleanliness, and extremely high levels of cleanliness are required. In recent years, it has become unsuitable for use in clean rooms. Recently, in order to overcome the drawbacks of such conventional dust-free clothing, proposals have been made for fabrics for dust-free clothing that have improved dustproof properties. The first measure is to prevent dust from permeating the material for dustproof clothing, such as cloth, by almost eliminating its breathability. Specifically, it is made by laminating a fabric and a microporous membrane made of synthetic resin (for example, Japanese Utility Model Application Publication No. 59-133615, Japanese Utility Model Application No. 133615,
59-35029) or fabric coated with a synthetic resin (for example, a comparative example of JP-A-59-115391). The second measure was proposed by the present inventors, and is one that has air permeability and high collection efficiency by improving the fabric structure (Japanese Patent Application Laid-open No. 74169/1989, Patent application 1986-26132
(Special Application No. 115391/1983). For both of these first and second measures, the air permeability is approximately 4 c.c./cm ² /sec.
The air permeability of the first type, which ^is lower than the conventional dust-free clothing exceeding Efficiency is generally high.
If the dustproof properties of the material itself are improved in this way,
The air permeability is also lower than traditional dust-free clothing,
However, the inventors of the present invention, etc.
As pointed out in Japanese Patent Application No. 60-173140) and Japanese Patent Application No. 59-115391 (see Japanese Unexamined Patent Publication No. 60-259649), when workers operate while wearing dust-free clothing, Dust inside clothing leaks directly from openings such as cuffs, ankles, and collar openings, which is a major cause of reduced cleanliness. The amount of air leaking from openings such as cuffs, ankles, and collar openings is generally proportional to the pressure inside the garment.
Since the pressure inside the clothing is a function of the air permeability of the material, the lower the air permeability of the material, the higher the pressure inside the clothing during operation, and the greater the amount of air leaking from the opening, that is, the amount of leaking dust. Therefore, when the dustproof properties of the material itself are increased, dust-free clothing has the drawback of increased dust leakage from the openings. Dust leakage from the cuffs
Because workers often handle products by hand, this not only reduces the cleanliness of the clean room, but also
The impact on cleanliness is particularly large in that the contamination of the product is significant. Therefore, it is particularly necessary to reduce dust leakage from the cuffs of dust-free clothing in which air permeability is lowered and the dust-proofing properties of the material itself are improved. Based on this viewpoint, the present inventors evaluated the ability to prevent dust from leaking from the cuffs of conventional dust-free clothing products, and as a result, the prevention performance was found to be insufficient. <Object of the Invention> In order to eliminate such drawbacks, the present invention has been made as a result of intensive studies, and has been developed to provide a dust-free garment made of a fabric having an air permeability of approximately 4 c.c./cm ² /sec or less. It has been discovered that highly dust-proof and dust-free clothing can be obtained by improving the sealing of the cuffs. That is, an object of the present invention is to provide dust-free clothing that has a high degree of dust resistance and can be used in modern clean rooms where high cleanliness is required. <Structure of the present invention> That is, the present invention includes conductive fibers having an electrical resistance value of 10 ¹⁰ Ω/cm or less, and an air permeability of approximately 4 c.c./cm ² /cm.
This is a dust-free garment characterized by being made of a fabric of sec or less and having an expansion stress (T) of 150 g or more at the cuffs. The material of the fiber is not particularly limited. For example, polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyamides such as nylon-6, nylon 66, and aromatic polyamides, polyolefins such as polyethylene and polypropylene, polyvinyl alcohol, polyvinyl chloride, and polyacrylonitrile. Examples include synthetic fibers made of polyvinyl polymers such as rayon fibers, acetate fibers, silk fibers, and glass fibers. The fibers may be composed of these materials alone or may be composed of two or more of these materials. In addition to its function as clothing, dust-free clothing is sometimes required to have chemical resistance, and is particularly required to have durability, washing resistance, and dry cleaning resistance. It is more preferable to use materials that can meet a wide range of these required characteristics, such as polyester-based materials such as PET and PBT, polyamide-based materials such as nylon 6 and nylon-66, or aromatic polyamide-based materials. It is. In the present invention, the fabric has an electrical resistance value of 10 ¹⁰ Ω/
cm or less, preferably 10 ⁹ Ω/cm or less, is mixed. The diameter of the conductive fiber is preferably 100 μm or less, particularly 60 μm. The electrical resistance value was determined by fixing both ends of the fiber to aluminum foil using conductive paste to serve as electrodes, sample length 2 cm, and applied voltage.
This is a value measured at 100V. Any fiber material may be used as long as the electrical resistance value of the conductive fiber is 10 ¹⁰ Ω/cm or less. That is, it includes any of metal fibers, carbon fibers, and organic conductive fibers. Examples of organic conductive fibers include synthetic fibers coated with carbon black or metal powder together with resin (Japanese Patent Publication No. 46-23799);
Those obtained by composite spinning using a polymer containing carbon black or fine metal powder as one component (Japanese Unexamined Patent Publication No. 48-48715), those obtained by forming a metal complex inside the fiber by diffusion of metal ions, Fiber containing cuprous iodide (Japanese Unexamined Patent Application Publication No. 1983-1999)
Publication No. 35004). Further, in the present invention, an antistatic finishing agent may be further added to the fabric mixed with conductive fibers, or antistatic synthetic fibers may be used. The triboelectric charge density of the antistatic fabric of the present invention is 7 μC/m ² or less. The air permeability of the fabric in the present invention is approximately 4 c.c./cm ² /
less than sec. Although it depends on the fabric structure, in general, as the air permeability of the fabric increases, the dust collection efficiency decreases. Furthermore, when operating while wearing dust-free clothing, the amount of air that passes through the dust-free clothing fabric depends on the air permeability of the fabric, and the greater the air permeability of the fabric, the greater the amount of air that passes through the fabric. The number of dust that passes through the fabric is proportional to the product of the amount of air and the collection efficiency. Therefore, the number of dust particles that pass through the fabric and leak out increases significantly as the air permeability of the fabric increases. If the air permeability of the fabric exceeds approximately 4 c.c./cm ² /sec, even if dust leakage from the cuffs is completely eliminated,
Because so much dust passes through the fabric, it cannot be used in clean rooms where a high degree of cleanliness is required. Therefore, the air permeability of the fabric in the present invention must be about 4 c.c./cm ² /sec or less. Preferably it is 1 c.c./cm ² /sec or less. The fabric may be a woven or knitted fabric, a nonwoven fabric, or a fabric coated with a resin or laminated with a membrane or film, and is not particularly limited. In the present invention, it is necessary that the expansion stress (T) is 150 g or more. The cuffs of dust-free clothing are generally made with a rubber-like elastic material, such as a rubber ring, sewn to the end of the cuff to prevent dust from leaking from the cuff, but there are cases where a rubber-like elastic material is not used. Some styles have cuffs closed with hooks after being worn for a long time, while others are made from knitted fabric.
However, in conventional dust-free clothing, T is small and sealing performance is insufficient. 150g or more of T, preferably
By weighing 400 g or more, the airtightness of the cuffs can be obtained that is suitable for fabrics for dust-proof clothing that have a high degree of dust-proof performance. There is no particular limit on the upper limit of T, but if the tightening force is too strong, the feeling of wearing will be poor, so it is desirable that it does not exceed 1000. The cuff sealing method that can be used in the present invention includes, for example, a method using a rubber-like elastic body such as a rubber string or a rubber belt, or a method in which the sleeve portion is made of stretchable fabric. Examples include knitted fabrics, textured yarn fabrics, non-woven fabrics, and fabrics coated or laminated with stretchable resins. <Effects of the present invention> (1) The dust collection efficiency of the fabric is high. (2) The cuffs have excellent sealing properties, so there is less dust leaking from the cuffs. (3) Compared to conventional products, it has higher dustproof properties as a dust-free garment. <Example> The present invention will be specifically described below with reference to Examples. Note that the evaluation method in the present invention is as follows. (1) Air permeability Evaluated by JIS L-1079 Frazier method. (2) Expansion stress (T) A metal rod with a diameter of 5 mm is fixed horizontally, and the upper side of the cuff of a dust-free garment is inserted horizontally into the other end of the metal rod. Fix the rod and insert the metal rod under the cuff. Then, lower the spring scale vertically until the distance between the uppermost surface of the upper metal rod inserted into the cuff and the lowermost surface of the lower metal rod is 8 cm, read the apparent stress at this 8 cm distance, and read the apparent stress on the spring scale. After correcting the weight,
Find the stress T. This operation is performed on both cuffs of the dust-free garment, the average value of both is determined, and this average value is taken as the expansion stress T of the dust-free garment. (3) Cuff length L In the method for measuring the expansion stress T in (2), the cuff length L is the inner diameter of the cuff when the expansion stress T is 10 g. (4) Extensional elasticity This is the extensional stress per 1% extension at an extension interval of 8cm, and was calculated using the following formula (1). Elongation elasticity = T / 8 - L / L × 100 (g / %) ... (1) (5) Dustproof properties of dustproof clothing A box with air inflow and outflow holes in the ceiling and lower sides (volume 0.7m3 ⁾ ) was installed in a clean bench of class 100 or below, and a person (subject) wearing dust-free clothing entered the box and exercised, and the amount of dust generated was measured using a dust counter. Air cleanliness of the box before people enter (as B/G)
The amount of dust was on the same level as on the clean bench (3 to 4 particles/dust of 0.3 μm or more). The subjects wore a commercially available cotton shirt under dust-free clothing, as well as boots for use in a dust-free room, a head hood, and gloves. Dust-free clothing and boots are all antistatic products that use conductive thread.
Exercises performed in boxing were arm swings (both feet on the ground)
It operated at a speed of 90 times per minute. Dust generated by operations within the box exits from the outflow hole of the box along with the airflow, and the number of dust particles is measured at the center of the outflow hole and calculated by subtracting B/G. Furthermore, the number of dust generated when performing the same stepping exercise while wearing only the above-mentioned underwear (cotton briefs and long-sleeved cotton shirt) was extremely high at 7,160 particles/piece. (6) Frictional charge density Static electricity safety guidelines of the Labor and Industrial Safety Research Institute (1978
(October) Structural standards for antistatic work clothes (No. 154 to 154)
The charging performance test method for antistatic work clothes (Page 161) (Fallerday gauge method, temperature and humidity 20℃, relative humidity 30%RH, standard cloth for measurement uses nylon cloth and polyacrylonitrile cloth) Therefore, it was carried out. Examples 1 and 2, Comparative Examples 1 ^and 2 Conductive fiber Metalian (Teijin Ltd. ) manufactured by ) was inserted at 1 cm intervals in the warp direction, with an air permeability of 0.8 cc/
Using a fabric of cm ² /sec, four types of identical overall-type dust-free garments were created, differing only in the stress T at the cuffs. These four types of dust-free garments had different expansion stresses T by sewing the same rubber cord to the cuffs and changing the diameter of the cuffs. Table 1 shows the cuff length, expansion stress, expansion elasticity, dust resistance, and triboelectric charge density of each dust-free garment. The amount of triboelectric charge of the fabric used here was 2.1 μc/m ² . Comparative Examples 3 to 7 Commercially available overall-type dust-free clothing was evaluated in the same manner as in Example 1 for air permeability, cuff length, expansion stress, expansion elasticity, dust resistance, and triboelectric charge density, and Table 2 shows the results. Comparative Example 3 uses a polyester filament fabric coated with a synthetic resin, which has very low air permeability and has the property of almost completely blocking the permeation of dust. Comparative Example 4 is a dust-free garment made of polyester filament fabric. Comparative Example 5 is a dust-free garment made of highly breathable polyester filament fabric that does not contain conductive fibers, and has hook-type cuffs. Comparative Examples 6 and 7 are dust-free garments made of highly breathable polyester filament fabric. Except for Comparative Example 5, conductive long fibers were mixed in the fabric. The expansion stress and dust resistance of Comparative Example 7 are as follows:
Of the three hook holes on the cuff, the one with the smallest cuff diameter was used for evaluation. As is clear from Table 2, the expansion stress T of all commercially available dust-free garments was 100 g or less. Furthermore, in Comparative Example 5, since a fabric in which conductive fibers were not mixed was used, almost no antistatic property was observed. Example 4, Comparative Example 8 For the dust-free garments of Comparative Example 3 and Comparative Example 7, in place of the rubber cords that had been unsewn and inserted at the cuffs, a rubber cord with greater elasticity was inserted between the original cuffs. The garments were sewn to have the same diameter to create dust-free garments with improved sealing properties at the cuffs (referred to as Example 4 and Comparative Example 8, respectively). Each cuff length,
Table 3 shows the expansion stress, expansion elasticity, and dust resistance. As is clear from the comparisons between Comparative Example 3 and Example 4, and Comparative Example 7 and Comparative Example 8, Comparative Example 3, which was made of a material with low air permeability, had poor dustproof properties due to poor sealing properties of the cuffs. However, in Example 4, in which the sealing performance of the cuffs was improved, the dustproof property was significantly improved. On the other hand, in Comparative Example 8, although the sealing performance of the cuffs was improved compared to Comparative Example 7, the dustproof property did not change much. Almost no improvement effect was observed even if the value was increased.

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Claims (1)

[Claims] 1. A fabric containing conductive fibers with an electrical resistance value of 10 ¹⁰ Ω/cm or less and an air permeability of about 4 c.c./cm ² /sec or less, and having an expansion stress ( A dust-free garment characterized by having T) of 150 g or more. 2. The dust-free garment according to claim 1, which has an air permeability of 1 c.c./cm ² /sec or less. 3. The dust-free garment according to claim 1 or 2, which has an expansion stress (T) of 400 to 1000 g.