JPH0351801B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to dustproof clothing. Precision industry, semiconductors,
So-called clean rooms are rapidly developing in the manufacturing process of pharmaceuticals, foods, etc., as well as in hospitals and fields that handle microorganisms, and there is a need for clothing with excellent dust resistance as working clothes in these clean rooms. It concerns dustproof clothing. Conventional technology The required performance of dustproof clothing is (a) high ability to prevent dust from passing through, (b) dust that is difficult to adhere to and easy to remove, (c) low dust generation, and (d) anti-static. (e)
Overall excellent performance is required, including excellent chemical resistance. Conventional materials for dustproof clothing include:
For example, as shown in the example of JP-A-55-30436, polyethylene terephthalate fiber is used, but this is unsatisfactory from the viewpoint of dust generation. That is, polyethylene terephthalate has a drawback in that its fibers tend to break, become fibrillated, and fall off due to friction during wear and washing, and generate dust. Problems to be Solved by the Invention An object of the present invention is to provide an improved dustproof garment that generates less dust. Means for Solving the Problem The dustproof clothing of the present invention has at least a portion of the fibers made of polyethylene terephthalate (hereinafter referred to as PET).
Polybutylene terephthalate (hereinafter referred to as PBT)
and modified products thereof, containing at least one lubricant selected from the group consisting of paraffin, polyolefin, polyalkylene ether, compound having an alkyl group, organic silicon compound, and organic fluorine compound. It is characterized by being made of a fiber structure having a coefficient of friction of 90% or less of that of a fiber containing no lubricant. Here, the modified product refers to PET or PBT containing a small amount (50% or less, especially 30% or less, most often 0.1 to
10%) A third component is copolymerized or mixed to change properties such as hydrophilicity, dyeability, color, antistatic property, and affinity with lubricants. For example, PET
By copolymerizing 0.5 to 5% of polyethylene oxide, polypropylene oxide, polybutylene oxide, etc. to (homopolymer), it is easy to contain an oil-like lubricant and the lubricant is easily leached to the surface even at relatively low temperatures (modification) You can. Specific examples of the above-mentioned lubricants include mineral oil, paraffin, polyethylene, polybutene, copolymerized polyolefins thereof, polyethylene oxide, polypropylene oxide, polybutylene oxide, copolymerized polyethers thereof, fatty acids, fatty acid esters or metal salts, higher alcohols, Examples include their esters, animal and vegetable oils, synthetic oils and fats such as alkylbenzene and polyalkyldiphenyl, silicone oils such as polyorganosiloxane, fluorinated ethylene polymers and copolymers, and compounds with fluorinated alkyl groups. . Even below the above, PET, PBT,
Materials that can be mixed with modified PET and modified PBT and whose friction coefficient can be reduced to 90% or less of the friction coefficient without additives can be used. Friction coefficient is 0.3 for PET and PBT
-0.4, but it is preferably reduced to 90% or less, particularly 80% or less, most preferably 60% or less by adding a lubricant (based on 100% when no lubricant is added). The coefficient of friction is determined by washing the fiber thoroughly with a solvent or a solvent after proper washing to eliminate the effects of oils, softeners, antistatic agents, etc. applied to the surface during spinning or dyeing, and if necessary, removing the inside of the fiber. Appropriate heating or aging (e.g.
(for at least 24 hours), then measure. Of course, it is necessary to choose a lubricant that is difficult to extract and fall off during normal washing or dry cleaning. The lubricant may be in the form of oil, wax, or resin, but from the viewpoint of leaching to the surface, lubricants with relatively small molecular weights (for example, molecular weight of 10,000 or less, particularly about 500 to 5,000) are preferable. On the contrary, from the viewpoint of washing resistance and dry cleaning resistance, it is preferable that the molecular weight is slightly larger (for example, 5000 to 50000). Addition of lubricants generally causes deterioration of fiber properties such as strength, elongation, elastic modulus, heat resistance, weather resistance, fibrillation resistance, and color fastness. It is desirable to add the necessary minimum amount. Usually, the lubricant content is
0.001-20%, particularly 0.01-5%, preferably 0.05-20%
2% is most preferred. The fiber containing a lubricant-containing polyester used in the present invention may be a single-component filament, but a composite filament in which a plurality of components are bonded together is also suitable. In particular, polymers that tend to contain lubricants as core components (e.g. PBT, modified PBT, modified PET, polyamides, modified polyamides, polyolefins, etc.) are made to contain a relatively large amount (e.g. 1 to 20%) of lubricants, either unmodified or modified. Core/sheath composite filaments that are gradually diffused into a sheath component of low polyester are among the most preferred fibers for purposes of this invention. The composite ratio of the core-sheath composite filament is arbitrary, but for example, 9/1 to 1/20 (volume ratio)
It can be done. When a highly modified polymer is used for the core and a large amount of lubricant is contained, it is desirable to reduce the composite ratio of the core. Also useful are conjugate fibers in which the lubricant-rich component occupies a portion of the surface of the fiber. In this case, although the advantage is that the lubricant easily leaches out onto the surface, the disadvantages are that the components that are easily degraded by the lubricant are exposed on the surface, and the lubricant is extracted and removed by washing, etc. Since there is a risk that the lubricant-containing ingredients will be lost due to aging, the lubricant-containing ingredients must be carefully selected. Such shortcomings are
This can be improved by reducing the surface area occupied by the lubricant-rich component, for example by setting the surface area occupancy to 30% or less, particularly 10% or less, most preferably 5% or less. FIGS. 1 to 6 are examples of cross-sectional views of composite fibers suitable for the present invention. In the figure, the component with a small lubricant content is indicated by 1, and the component with a large content is indicated by 2. Of course, even if component 1 does not contain any lubricant at the time of composite spinning, the lubricant in component 2 can be diffused into component 1 by heating or aging. Figure 1 shows a concentric core-sheath type, Figure 2 shows a type with a non-circular core, Figure 3 shows a type with a non-circular core and sheath, and Figure 4 shows a type with a non-circular core and sheath.
Figures 6 to 6 show examples in which the surface area occupation ratio of component 2, which has a large lubricant content, is reduced. FIG. 7 is an example of a normal parallel composite in which the surface area occupancy of component 2 is 50%. When components 1 and 2 in Figures 1 to 6 are exchanged, the component containing more lubricant occupies all or most of the surface of the fiber, so the effect of the lubricant is remarkable, but the effect of the lubricant is significant. Care must be taken to avoid deterioration of the properties of Of course, the same applies to monocomponent fibers made of only one component including a lubricant. The cross-sectional shape of the composite fiber or monocomponent fiber may be circular or non-circular. Although non-circular fibers have excellent ability to prevent the passage of dust, they have the disadvantage of being easily fibrillated due to friction, so care must be taken. Single yarn fineness is 0.1
~5d is preferred, especially 0.5-3d, most preferred is 0.7-2.5d. The fabric preferably has low air permeability from the viewpoint of preventing dust from passing through. Air permeability is measured by JISL-1096 (1979) A method (Fragir method). Air permeability is 30
ml/cm ³ /sec or less is preferred, 10 ml/cm ³ /sec is particularly preferred, and 5 ml/cm ^{3 /} sec is most preferred. However, if the breathability is too low, the feeling of wearing will be poor.
0.1 ml/cm ³ /sec or more, particularly 0.3 ml/cm ^{3 /} sec or more is preferred. Cloths with low air permeability (high dust-blocking ability) are
It is obtained by spinning thin fibers (for example, single yarns of 3 d or less, especially 0.1 to 2 d) at high density or shrinking them at a high shrinkage rate (for example, area shrinkage rate of 10% or more, especially 20 to 50%). Furthermore, if necessary, the blocking ability can be increased by densifying the fabric by pressing the fabric, such as by calendering, or by applying a thin resin film to the fabric by laminating or coating. Preferably, the fabric is antistatic. This is to prevent the adsorption of dust and microorganisms due to static electricity, as well as to prevent destruction of semiconductors due to static electricity in industries that handle semiconductors. For this reason, it is preferable that the electrostatic voltage (absolute value) when the fabric is placed on a wooden table and sufficiently rubbed with a friction cloth made of cotton, wool, or acrylic fibers and then removed from the table is 6 KV or less. In particular, it is preferably 3KV or less, and most preferably 2KV or less. Frictional electrification can be measured accurately by the method disclosed by the present inventors in Japanese Patent Application Laid-Open No. 56-48550, particularly by the apparatus disclosed in FIG. 2 or 3 of the same publication. The atmosphere for sample preparation and measurement shall be 25℃ and 40%RH (JIS L-
1094 (1980) B method, the measurement of frictional charging voltage using a so-called rotary static tester is not preferred because it has large errors and poor reproducibility). There is a difference between the charged voltage E (volts) measured by the method disclosed by the inventors and the amount of electricity Q (coulombs/m ² ) of the cloth per unit area measured by the Faraday cage method.
It has been confirmed that the relationship Q=3×10 ^-10 E holds true in the region below 8KV. In other words, the charging voltage
6KV is approximately 1.8μC/m ² , 3KV is 0.9μC/m ² , 2KV is approximately
Corresponds to a charge density of 0.6 μC/m ² . In order to impart the above-mentioned antistatic properties to fabrics, the optimal method is to mix conductive fibers. Conductive fibers include metal fibers, metal-plated fibers, metal compounds (semiconductors, etc.), fibers that have a conductive layer on the surface or inside made of other conductive substances (specific resistance of 10 ⁷ Ω・cm or less), conductive particles, or Examples include fibers having a conductive layer on the surface or inside thereof made of a resin mixed with a component having high conductivity. Examples of the conductive particles include carbon black, metal particles, metal compound particles, and particles having a thin layer of metal or metal compound on their surfaces. Among them, the most suitable is a composite fiber in which a conductive layer containing conductive particles and a protective layer made of a fiber-forming polymer are bonded together.
The electrical resistance per 1 cm length of the conductive fiber is preferably 10 ¹⁰ Ω or less, most preferably 10 ⁸ Ω or less. Fig. 8 shows a method for measuring dust generation of knitted fabrics. The upper end of the sample 3 is fixed to a support rod 4, and a load 5 is applied to the lower end.
is attached and a constant tension is applied. On the other hand, a plurality of friction rods 7 are attached to the rotary plate 6, and the surfaces thereof are covered with a friction cloth 8. When the rotary plate 6 rotates in the direction of the arrow, the sample 3 is intermittently rubbed by the friction cloth 8, and the generated dust is sucked through the air suction port 9 and measured by the particle counter 10. 11
is an inlet for clean air from which dust has been removed by a high-performance filter, and 12 is a case. If the friction cloth 8 is omitted, dust generation due to friction between the sample and the friction rod can be evaluated. The friction rod may be made of metal, ceramics, resin, etc. depending on the purpose, but it is generally good to use one with excellent wear resistance, and the shape can be arbitrary, but round rods are common. The friction cloth is also optional, but nylon, polyester, etc., which have excellent abrasion resistance, are preferable. It is also possible to use 8 as a sample and 3 as a friction cloth. In the example below, the sample is 6 cm wide, ultrasonic (melting) cutting is used to prevent dust from the cut surface, and the sample is folded in half (width 3 cm) and mounted so that the cut part is at the center of the back, and the load is 60 g. do. Similarly, the friction rod has a diameter of 8
mm, length 6cm, made of hard alumina porcelain.The friction cloth is ultrasonically cut 40D/10F tricot (knitted fabric) of nylon 6 without pigment into a width of 5cm.It is attached so that the cut surface does not come into contact with the sample. . Disk 11
The rotation speed of is 30 rpm (number of frictions: 180 times/min). The sample should be washed with clean water and dried in a clean room. The measuring device will also be installed in a clean room (a clean bench may be used). The air suction rate of the particle counter 15 is 0.5/min. The coefficient of friction of fibers is measured as follows. The sample (filament) was thoroughly washed with a benzene/methanol (1/1) mixture and heated in dry heat at 120℃ for 20 minutes.
Use one that has been heat-treated for a minute. As the friction body, a hard chrome-plated steel round bar with a diameter of about 1 cm is used as the friction body, and while the thread is in 180° contact with the friction body,
Tension before and after the friction body when running at a speed of 300 m/min
Measure T ₁ and T ₂ . Adjust T ₁ to 10g using a tension adjuster. The friction coefficient is calculated using Equation 1. Friction coefficient μ=0.732logT ₂ /T ₁ (Formula 1) Examples In the following examples, parts, percentages, etc. are weight ratios unless otherwise specified. Example 1 PET with a molecular weight of 18,000 and containing no pigment was spun at 285°C from an orifice with a diameter of 0.25mm, cooled, reeled at a speed of 1500 m/min while being oiled, stretched 3.3 times at 80°C, and subjected to tension heat treatment at 150°C. The drawn yarn with a circular cross section of 75d/36f obtained in this manner is designated as Y1. obtained in the same way
A drawn yarn with a circular cross section of 150d/48f is designated as Y2. The friction coefficients of Y1 and Y2 were 0.41 and 0.41, respectively. Y1,
Y3 is a yarn in which one conductive composite fiber (Kanebo, polyester "Beltron") 20d/6f is combined into one yarn. A plain woven fabric was obtained using Y1 and Y3 (one at 4 mm intervals, conductive yarn mixing rate of about 0.8%) as warp yarns and Y2 as weft yarns, and the woven fabric dyed and finished by a conventional method is hereinafter referred to as F1. The air permeability of F1 was 1.3 ml/cm ³ /sec, and the frictional charging voltage when wool was used as the friction cloth was -1.8 KV. F2 is a fabric obtained in almost the same manner as F1, except that 0.2% of silicone oil (polymethylphenylsiloxane, Shin-Etsu Chemical, KF54) is mixed as a lubricant during PET spinning. The friction coefficients of the warp and weft of F2 were 0.33 and 0.32, respectively, which were 80% and 78% of those without silicone oil, respectively.
The air permeability of F2 was 1.3 ml/cm ³ /sec, and the frictional charging voltage was −1.9 KV. A polyester with a molecular weight of 20,000 obtained by copolymerizing 3% of polybutylene glycol with a molecular weight of 600 with respect to PET is designated as polymer P1. Molecular weight relative to PBT
Polymer P2 was prepared by copolymerizing 8% polybutylene glycol of 2000 with a molecular weight of 21000, 1.2% titanium oxide particles as a pigment, and 3% of the above silicone oil as a lubricant. Polymer P1 is used as a sheath,
Using polymer P2 as a core, both were composite-spun into a core-sheath type (volume composite ratio 2/1) at 285°C as shown in Figure 1.
A drawn yarn of 75d/36f was wound at a speed of 1500 m/min, stretched to 3.4 times at 80°C, and subjected to tension heat treatment at 150°C.
Let Y4 be the same, and let the drawn yarn of 150d/48f be Y5.
A yarn made by twisting Y4 and the conductive composite yarn 20d/1f.
Let's say Y5. Y3 and Y5 (4mm interval) are the warp threads,
A plain woven fabric was obtained using Y5 as the weft, and the woven fabric dyed and finished by a conventional method is hereinafter referred to as F3. Air permeability of F3 is 1.0
ml/cm ³ /sec, and the frictional charging voltage was −1.8 KV. For comparison, Y6 is a drawn yarn of 75d/36f produced under the same spinning and drawing conditions from a monocomponent yarn made only of polymer P1, and Y7 is a drawn yarn of 150d/48f.
F4 is a plain woven fabric (dyed finished product) obtained by twisting and twisting the conductive composite yarns to Y6 and Y6, with Y8 as the warp and Y7 as the weft. Air permeability of F4 is 1.1ml/ ^cm3 /
seconds, the frictional charging voltage was 1.9KV. The friction coefficients of Y3 and Y5 are 0.30 and 0.31, which correspond to 66% and 67% of those of Y6 and Y7, respectively. The friction dust generation properties of each fabric were measured by the method shown in FIG. Particles are 5μm or more, 2μm or more, 1μm or more,
Count the air by dividing it into 0.5 μm or more and 0.3 μm or more
(2 minutes) Indicated by the number in the middle. The friction was carried out continuously for about 1 hour, and the average from 0 to 4 minutes was taken as the count after 2 minutes, the average from 28 to 32 minutes was taken as the count after 30 minutes, and the average from 58 to 62 minutes was taken as the count after 60 minutes. Show with 3 significant figures (round 4 to 5). In addition, dust generation properties were similarly measured after each fabric was washed 50 times (drying at 110°C for 20 minutes). The results are shown in Table 1.

[Table] Example 2 Composite spinning was carried out using a polymer that was almost the same as polymer P2 of Example 1, except that 3% of each of various compounds was mixed in place of silicone oil as a lubricant, and P1 was used as a sheath. The dust generation properties of five types of plain woven fabrics F5 to F9 obtained in the same manner as F3 in Example 1 were measured. Table 2 shows the relationship between the type of lubricant and the mixing ratio. The number of dust particles is the value after 1 hour of friction.

[Table] The friction coefficient ratio is for polymer P1 of Example 1.
The ratio (75d, 150d average) to the friction coefficient of the drawn yarn made of Example 3 Polymers P1 and P2 of Example 1 were melt-spun at a composite ratio of 3/1 as shown in Figure 4 to obtain 75d/
Drawn yarns of 36f and 150d/48f were obtained. The coefficient of friction was 56% compared to that of yarns Y6 and Y7 of Example 1, respectively.
It was 58%. Example 1 below using the above drawn yarn
F10 is a plain woven fabric obtained in the same manner as F3.
Table 3 shows the dust generation properties of F10 (after 1 hour).

[Table] Effects of the Invention As is clear from the examples, the dustproof clothing of the present invention has low dust generation due to friction and is excellent. This effect was obtained by reducing the coefficient of friction by incorporating a lubricant into the fibers. It is also desirable that the result be durable against washing and dry cleaning. The washing and cleaning durability of the friction coefficient reducing effect can be sufficiently increased by appropriately selecting the type of polymer, the type of lubricant, and the composite structure (particularly the core-sheath type).

[Brief explanation of drawings]

1 to 6 are examples of cross sections of composite fibers suitable for the present invention, and FIG. 7 is an example of a cross section of parallel composite fibers. FIG. 8 is an explanatory diagram showing a method for measuring dust generation.

Claims (1)

[Scope of Claims] 1 At least a portion of the fiber is a polyester selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and modified products thereof, and a paraffin, a polyolefin, a polyalkylene ether, a compound having an alkyl group, and an organic silicone. A dustproof structure made of a fiber structure containing at least one type of lubricant selected from the group consisting of compounds and organic fluorine compounds, and the coefficient of friction of the fibers is 90% or less of that of the fiber without the lubricant. Clothes. 2. The dust-proof clothing according to claim 1, wherein the friction coefficient of the lubricant-containing polyester is 80% or less of that of the polyester without the lubricant. 3. The dust-proof garment according to claim 1, wherein part or all of the fibers are core-sheath composite fibers having a core made of a polymer containing a lubricant and a sheath made of polyester with a lubricant content lower than that of the core polymer. . 4 Some or all of the fibers that make up the fabric are
The surface area occupancy of the component made of polymer with a high lubricant content is 50% or less, and the surface area occupancy of the component made of polyester with a low lubricant content is 50%.
The dustproof clothing according to claim 1, which is made of the above composite fiber.