JPH03249203A - Dust-proof cap - Google Patents

Abstract

PURPOSE:To obtain the subject working cap excellent in resistance to coming off of hairs, dusts, etc., derived form a worker, excellent in air transmissivity and free from stuffiness by using a non-woven sheet composed of a fiber having a specified fineness and elecret properties and having many pores. CONSTITUTION:An objective cap produced by using a non-woven sheet composed of a fiber having 0.5-6mum average diameter and elecret properties and having many pores. In addition, polyethylene terephthalate, nylon 6, PE, etc., are exemplified as the fiber material constituting the non-woven sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dustproof hat. In more detail, it has excellent properties to prevent hair and debris from falling off (dust-proof) from workers.
Furthermore, the present invention relates to a dustproof hat for various types of work that does not get smelt because it has excellent breathability.

[Conventional technology]

In the medical field, food field, electronic field, pharmaceutical field, etc., a simple hat called a hair cap is used to suppress dust such as hair, dandruff, flakes, and bacteria from workers.

Hats of this type that are made of ordinary non-woven fabrics or woven or knitted fabrics are breathable, but are less dust-proof, while hats that are made of film are dust-proof but are not breathable and can get stuffy. There was a problem.

In an attempt to solve the conflicting issues of dustproofness and breathability, sheets using microfiber nonwoven sheets have been developed in recent years. For example, Japanese Patent Application Laid-Open No. 62-94180 discloses that a fiber aggregate made of one or more laminated ultrafine long fiber webs or sheets with a single fiber diameter of 0.1 to 5.0 µm has a porous sheet on one or both sides. A hood mask is disclosed in which a fiber structure having an air permeability of 1 cc/d·sec or more is used in part or in whole by bonding and integrating the above.

Further, JP-A-1-280007 discloses a dust-proofing device characterized by using an electret material having a surface charge density of I Xl0-'' coulombs/c+f1 or more and an air permeability of 10 to 100 OCC/Cl11·sec. Hats for use are disclosed.

[Problem to be solved by the invention]

However, although the ultrafine fiber sheets described in the above-mentioned two publications were excellent in dust resistance, they were inadequate in terms of breathability. It is particularly unsuitable for wearing for long periods of time, for work that involves a lot of movement, for work in the summer, or in relatively high-temperature environments.

An object of the present invention is to solve the above-mentioned problems and provide a soft dustproof hat that has higher dustproofness, higher air permeability, and stronger strength than conventional hats.

[Means for #determining issues]

The present invention is a dustproof hat characterized by using a nonwoven sheet having a large number of small holes and made of electret fibers having an average fiber diameter of 0.5 to 6 μm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings, which are shown as an embodiment of the dustproof hat of the present invention.

Figure 1 shows the dustproof hat (hair cap) of the present invention.
It is a schematic perspective view showing an example of the external appearance, and the dustproof hat of the present invention uses an electro-grooved nonwoven sheet (1) having a large number of small holes (2). )
It is circular in shape and has an opening (3) at the bottom for inserting the head.

The dustproof cap opening (3) preferably has a structure in which a tightening tool (4) made of an elastic material or a tightening string is attached. The elastic material or tightening device is used to prevent the cap from coming off easily, and can be appropriately used in the form of a string, a belt, a hook, a zipper, or the like.

Stretchable materials can be virtually any stretchable material, such as rubber cord, or a material with a bag-shaped end that can be pulled and tightened. etc. can be used.

The average fiber diameter of the nonwoven sheet (1) used in the present invention is 0.5
~6μ intestine is required. If the diameter is less than 0.5 μm, the strength of the nonwoven sheet will be low, and the air permeability will also be low. % or more, the dustproof property and strength will be inferior.The total opening area ratio is the percentage of the total opening area of the small holes to the sheet area.

On the other hand, if the diameter is 6 μm or more, there is good air permeability, but even if the total opening area ratio is 1% or less, the dustproof property is poor.

The fiber materials constituting the nonwoven sheet (1) used in the present invention include polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, nylon 6.
6, polyolefins such as polypropylene and polyethylene, polyurethanes, and thermoplastic elastomers such as hydrogenated block copolymers of block copolymers of vinyl aromatic compounds and conjugated diene compounds. Furthermore, copolymers and blends of these polymers may also be used.

A typical hydrogenated block copolymer of a vinyl aromatic compound and a conjugated diene compound is manufactured by Shell Chemical Co.
+1cal Company) JP-A-61-425
The thermoplastic material trade name Krato disclosed in Japanese Patent Application No. 54 and Japanese Patent Application Laid-Open No. 155446/1983
n) is known.

For information on the thermoplastic material Kraton, please refer to the booklet rKRATON@T)IERMOPLAsT published by Shell Chemical Company.
IcRUBBERTypical Property
s 1986J, and the most
The boat fishing structure is a linear A-B-A block type, with styrene-ethylene/butylene-styrene (S-E
There is B-3) Kraton G series.

JP-A No. 61-42554 discloses that at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a hydrogenated conjugated diene compound are used. A composition is disclosed in which 0.01 to 3 parts by weight of a hindered amine compound is added to 100 parts by weight of a hydrogenated block copolymer having the following properties.

The nonwoven sheet used in the present invention is polyolefin, because ultrafine fibers can be easily obtained by melt blowing, high dust resistance can be obtained by electret treatment, and it has a soft texture and excellent fit and touch. A hydrogenated block copolymer of a block copolymer of a vinyl aromatic compound and a conjugated diene compound is preferred. In particular, it has at least two polymer blocks A mainly composed of polypropylene and a vinyl aromatic compound, at least two polymer blocks B mainly composed of a conjugated diene compound, and at least one polymer block B
is at the end of the polymer chain, and the overall number average molecular weight is 30.
,000 to 65,000, and a hydrogenated block copolymer obtained by hydrogenating a block copolymer having a vinyl aromatic compound content of 15 to 40% by weight, and this copolymer. Blends of polyolefins and polyolefins are preferred. Furthermore, since the above-mentioned hydrogenated block copolymer provides a soft and stretchable nonwoven sheet, the fit and touch are further improved. Further, when this copolymer is used, the nonwoven fabric sheet is elastic, so the above-mentioned dustproof cap opening (3) does not necessarily require a separate tightening member (4).

The basis weight of the nonwoven sheet used in the present invention is preferably 10 to 60 g/, particularly preferably 15 to 40 g/I. If it is less than 10 g/rrf, the dustproofness and strength will be poor, while if it is more than 60g/rrf, if the total opening area is increased to obtain sufficient ventilation, the dustproofness will be poor. Moreover, the bulk density is 0.1 to 0.
3 g/ctA is preferred.

The methods for manufacturing the nonwoven sheet used in the present invention include a melt blow method, a method of forming a sheet by direct spinning and then forming a sheet, a method of performing sea-island spinning or blend spinning and dissolving and removing components after forming into a sheet, and forming a sheet of split fibers. Various methods are used, such as
Particularly preferred is the melt blow method.

Regarding the melt blowing method, please refer to the Industrial and Engineering Chemistry (Industrial and Engineering Chemistry)
and Engineering Chemistry
y) Published in 1956, Volume 48, No. 8, No. 1342~
On page 1346, the basic method and apparatus for carrying out the method are disclosed. Further, Japanese Patent Publication No. 33511/1982 and Japanese Patent Application Laid-open No. 142757/1983 disclose methods for producing ultrafine fibers such as polyolefins and polyesters.

The nonwoven sheet used in the present invention needs to be treated with electret. Dust resistance (collection efficiency) is significantly improved by electret treatment. The degree of electretization is 3X10-'. Chron/d. Preferably 5X10-' coulombs/C-1, more preferably 7X
10-'' coulomb/cd. Various known methods can be used to convert a nonwoven sheet into an electret. For example, a nonwoven sheet can be heated to around its softening temperature, and then cooled while applying a high DC voltage. Thermal electret, which applies a corona discharge or pulsed high voltage to the surface of a nonwoven sheet, and radio electleft, which applies T-rays or electron beams, can be used.

The method described in JP-A-63-150909, in which a ground electrode having a porous surface is used to perform corona discharge, is also a preferred method.

FIGS. 2 and 3 are plan views showing an example of the nonwoven fabric sheet (1) constituting the dustproof cap of the present invention, which has a large number of small holes (2). The shape of this small hole may be any shape such as a circle, an ellipse, a triangle, a polygon such as a square, or the like. Also,
Items with different shapes may be mixed. A preferred shape is a circle or an ellipse.

The opening area of one small hole is 1 to 20-1, especially 2 to 15
- is preferred. If it is less than 1, it is necessary to make a large number of holes in order to maintain sufficient air permeability, and the strength of the nonwoven sheet decreases.

On the other hand, if it is 20 or more, the dust resistance and strength will be poor.

Moreover, the total opening area ratio of this small hole is 1 to 20%, especially 1.
5 to 10% is preferred. If it is less than 1%, the breathability will be poor;
If it is more than 0%, the dust resistance and strength will be poor.

The nonwoven sheet used in the present invention has an average fiber diameter of 0.5 to 6.
When all of the following conditions are satisfied: being composed of electret fibers of μm, the opening area of the pores being 1 to 20 d, and the ratio of the total opening area of the pores being 1 to 20%, We have found that the king of dustproofness, breathability, and strength provides the best balance.

It is preferable that the ultrafine fibers constituting the periphery of the pores be fused and bonded, since tearing and tearing from the pores can be prevented and the strength of the nonwoven sheet will be increased. It is also preferable from the viewpoint of preventing fluff from surrounding the small pores and shedding of single fibers.

As a method for opening the small holes, a punching method, a method using a roll provided with a large number of small protrusions or needle-like objects, etc. are commonly used. Melting and bonding the peripheral edge of the small hole can be easily achieved by performing the above method in a heated state. Furthermore, by setting the temperature and press pressure high in a hot embossing method using an engraved roll, it is also possible to obtain small holes whose peripheral portions are melt-bonded.

The air permeability of the non-edge sheet used in the present invention is 30 cc/c
111 seconds or more, particularly 40 to 200 CC/c1 fl.seconds, is preferable from the viewpoint of causing stuffiness when worn.

In addition, as for dust resistance, the collection efficiency is 20% or more, especially 3
If it is 0% or more, it is practically sufficient.

Further, the nonwoven sheet may be a mixture of two or more types of materials and fibers with different average fiber diameters, or may be a lamination of spunbond, dry, wet, etc. nonwoven fabrics. If necessary, some of the fibers may be bonded using a hot embossing roll, an ultrasonic bonding method, or the like.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.

The definitions and measurement methods of various physical properties shown in Examples and Comparative Examples are shown below.

(1) Average fiber diameter (μm) Ten arbitrary points on the sample were examined using an electron microscope at a magnification of 2000.
Take 10 photos at double magnification. Measure the diameter of 10 arbitrary fibers for each photograph, and do this for each of the 10 photographs. A total of 100 fiber diameter measurements are obtained and the average value is calculated.

(2) Thickness (m) Measured using a peacock type thickness gauge under a constant load of 130 g/c+d.

(3) Bulk density (g/cffl): Measure the thickness under a constant load of 130 g/cal and calculate from the basis weight.

(4) Collection efficiency (%) Rion particle counter (PARTICLE)
Using the KC-OIA model (trade name), the blank value A (
Next, a sample is set, the number of particles B (pieces) passing through the sample is measured, and the collection efficiency is determined by the following formula.

Collection efficiency = (1-B/A)xlOO (5) Air permeability (cc/c111・sec) Measured by JIS-1096 Fraziel method.

(6) Tensile strength (in g/cm) A sample of 20 mm width x 160 m length was taken and measured using a universal tensile tester (Tensilon) at a gripping length of 100 mm, a load capacity of 100 kg, and a tensile speed of 100 mm/min. Convert the value to ICII + width, and find the average value for the vertical and horizontal values.

(7) Tear strength (g) Take a 6011III medium x 65 length sample, place it on a sample stand, and make a cut with a knife.

Read the maximum vibration using an Elmendorf tear tester,
Find the average vertical and horizontal values.

(8) Opening area (-) Directly measure the major axis and minor axis of the small hole in the sample to calculate the area of the hole.

Examples 1 to 4 and Comparative Examples 1 to 3 Polypropylene fiber webs having various average fiber diameters shown in Table 1 were obtained by a melt blowing method. The basis weight of this web is 30g#+ (, thickness 0.21 plate, bulk density 0.1
It was 4 g/c+l. This web was subjected to electroleft processing by applying a voltage of 19 kV and corona discharge.

Next, a large number of oval small holes of 10 m + equal pitch were made using a roll equipped with a large number of heated needles. At this time, the opening area of one small hole is 2-1.The total opening area ratio of small holes is 2%.
Met. In addition, the fibers around the pores were heat-fused, and no fluff was required. The physical properties of this unmarried sheet are
Shown in the table. Table 1 shows that the nonwoven sheet used in the present invention is excellent in collection efficiency, air permeability, and strength.

A dustproof hat shown in FIG. 1 was made using this nonwoven sheet. I wore this dust-proof hat for 7 hours in a clean room, but it did not cause any stuffiness, and it was an excellent hat that did not actually cause problems with environmental pollution.

Table C (margin below) Comparative Example 3 is a non-woven sheet with no small holes and has low air permeability, so the dustproof hat made using this sheet feels stuffy. Furthermore, it can be seen that the nonwoven sheet used in the present invention has higher strength than a sheet without holes because the fibers around the holes are thermally fused.

Examples 5 to 12 By melt blowing, the average fiber diameter was 1.2 μm and the basis weight was 3.
A polypropylene fiber web having a thickness of 5 g/rrf and a thickness of 0.22 turns was obtained. Various small circular holes were made in this web using a heated needle. This perforated web was subjected to electret treatment by corona discharge.

The physical properties of this nonwoven sheet are shown in Table 2.

(The following is a blank space) As is clear from Table 2, the nonwoven sheet used in the present invention is excellent in collection efficiency and air permeability.

Using the nonwoven sheet shown in Table 2, a dustproof hat shown in Figure 1 was made and tested for wearing. As a result, all of the Examples were free from steam, but those of Examples 9 and I2 had somewhat insufficient dustproof properties and were easily torn.

Example 13 A butadiene-styrene butadiene-styrene type block copolymer C&! was produced by sequential block copolymerization using a lithium alkyl catalyst. l composition weight%1
0-12.5-65-12.5) was synthesized as a precursor polymer. This precursor polymer had a number average molecular weight of 47,
000, the polystyrene content was 25% by weight, and the amount of 1,2-bonds of conjugated diene was 31% by weight. This precursor polymer was hydrogenated and a hindered amine stabilizer was added to
% by weight was added to form pellets to obtain a hydrogenated block copolymer.

This hydrogenated block copolymer chip has a number average molecular weight of 45. '000 polypropylene chips were blended in a ratio of 85/15, and a web with an average fiber diameter of 2 pm, a basis weight of 40 g/rrr, and a bulk density of 0.27 g/cn was obtained by melt blowing.

This web was subjected to the electroleft treatment in the same manner as in Examples 1 to 4, and a large number of circular holes with a diameter of 311III+opening area of 7- were punched at room temperature.

The total open area ratio of the small pores was 1.5%. The collection efficiency of the obtained nonwoven sheet was 42%, and the air permeability was 50cc/ci.
seconds, tensile strength was 310 g/an width, tear strength was 300 g, and elongation was 260%. Dust-proof hats made of this non-woven sheet had excellent dust-proof properties and no stuffy feeling (and also had excellent fit due to its elasticity).

〔Effect of the invention〕

The dustproof hat of the present invention is extremely effective in removing hair and other dust particles that have fallen into the dustproof hat due to the synergistic effect of the electrical adsorption power of the electret fibers and the mechanical filtering performance of the ultrafine fibers. Adsorbs and collects and has excellent dustproof properties.

It also has excellent breathability and strength, and has a soft texture that does not make you feel stuffy when you wear it.

Therefore, it is effective when used in clean rooms, operating rooms, drug manufacturing rooms, cooking rooms, work rooms such as food manufacturing and hygiene-related industries, and other environments where contamination by contaminants from the head should be prevented. It is especially suitable for use in cooking rooms and food manufacturing work rooms.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of the external appearance of an example of the dustproof cap of the present invention, and FIGS. 2 and 3 are schematic plan views showing an example of a nonwoven sheet used in the dustproof cap of the present invention. . 1 - Non-woven sheet 2 - Small hole 3 - Dustproof cap opening 4 - Tightening member 5 - Periphery of small hole

Claims (1)

[Claims] 1. A dustproof hat characterized by using a nonwoven sheet having a large number of small holes and made of electret fibers with an average fiber diameter of 0.5 to 6 μm.