JPH05331767A - Nonwoven fabric - Google Patents

Abstract

PURPOSE:To obtain a polyolefin nonwoven fabric with a combination of high- level antistaticity and water repellency both desired for specific applications, by treating a polyolefin nonwoven fabric with an antistatic agent high in surface tension. CONSTITUTION:The objective polyolefin nonwoven fabric having the above- mentioned advantages can be obtained by imparting (A) a polyolefin nonwoven fabric >=1m<2>/g in specific surface area and 40-75% in porosity (produced by flash spinning, melt blow process, etc.) with (B) an antistatic agent >=45dyne/cm in the surface tension of its 1% aqueous solution. The present nonwoven fabric has the following characteristics: (1) water-repelling degree: 2 80; (2) water- bearing pressure: >=500mmH2O; (3) surface resistivity: <=10<9>OMEGA. The antistatic agent meeting the purpose is e.g. a methoxyalkyl phosphate salt, alkylalkylene oxide phosphate salt, oxacycloalkylmethyl phosphate salt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin non-woven fabric having a waterproof property and an excellent antistatic property. More specifically, the present invention relates to a non-woven fabric having a high balance of waterproofness and antistatic property, and having a proper moisture permeability and flexibility, which is useful for protective clothes, work clothes, windbreakers, rain clothes and the like.

[0002]

2. Description of the Related Art When non-woven fabric is used for the above-mentioned purposes,
It is required to have waterproofness and antistatic properties. However, since the polyolefin non-woven fabric is poor in antistatic property, it is necessary to perform antistatic processing. As a non-static treated non-woven fabric, Japanese Patent Publication No. 55-5106

Japanese Patent Laid-Open No. 8 discloses a chemical formula 1 in which n is 1.
With the compound of

[0004]

[Chemical 1]

It has been disclosed that if a fiber treatment agent in which a compound having n of 2 is mixed is used, antistatic property can be imparted without impairing waterproof property. In addition, the present inventors aim to improve antistatic and waterproof performances.

A fiber treating agent comprising a compound represented by the following chemical formula (1) and a compound 2 represented by the following chemical formula (2), wherein the molar ratio of the compound of (1) is at least twice that of the compound of (2). Polyolefin nonwoven fabric containing 0.05% by weight or more and a waterproofing agent comprising a fluorocarbon compound in an amount of 0.05% by weight or more

[0007]

[Chemical 2]

Was found to have excellent waterproofness and antistatic property, and it has already been filed as Japanese Patent Application No. 1-279765.

[0009]

However, depending on the use of the antistatic waterproof clothing, higher performance antistatic properties and waterproof properties are required. For example, in protective clothing and work clothes in a nuclear power plant or in a workplace where there is a risk of explosion or ignition due to electrification, it is required that water does not completely penetrate into the clothes and that electrification does not occur at all. ..

The present invention is to provide a non-woven fabric having a high degree of waterproofness and antistatic property, which can be applied to such applications.

[0011]

Means for Solving the Problems The present invention does not use a compound having hydrophilicity, which is a characteristic of conventional antistatic agents, but uses an antistatic agent having a high surface tension value to provide a waterproof polyolefin nonwoven fabric. It was completed by applying antistatic processing to. The object of the present invention is to have a specific surface area of 1 m ² / g or more,
And 1 for polyolefin nonwoven fabric with porosity of 40-75%
% Aqueous solution having a surface tension value of 45 dyne / cm or more can be achieved by depositing 0.1 wt% or more of an antistatic agent. The polyolefin nonwoven fabric of the present invention has a high balance of excellent waterproofness and antistatic property.

In order to impart waterproofness to the polyolefin nonwoven fabric used in the present invention, it is necessary that the specific surface area is 1 m ² / g or more and the porosity is 75% or less.
A specific surface area of 1 m ² / g or more indicates that the fibers constituting the sheet are extremely fine, and a porosity of 75% or less indicates that the structure is dense. As such a non-woven fabric, a polyolefin non-woven fabric produced by a flash spinning method or a melt blow method is preferable. The non-woven fabric before antistatic waterproofing used in the present invention can be manufactured by a known method. For example, JP-A-61-160469 discloses a method for producing a polypropylene continuous filament nonwoven fabric,
Japanese Unexamined Patent Publication No. 63-6107 discloses a method for producing a nonwoven fabric of polypropylene ultrafine fibers by a melt blow method. Further, as an example of the flash spinning method, for example, Japanese Patent Publication No. 62-172073 discloses an example of high density polyethylene, and Japanese Patent Publication No. 62-192598 discloses an example of polypropylene.

The following method is an example of the flash spinning method. When a polyolefin polymer is dissolved in a halogenated carbon such as trichlorofluoromethane or trichlorotrifluoroethane, a hydrocarbon such as methylene chloride, or a mixture thereof at high temperature and high pressure, a sharp pressure loss is applied to it, resulting in extremely fine solution. Shows the structure as if they were phase separated. This liquid material is discharged from a spinning nozzle to orient the polymer and form a three-dimensional reticulated fiber. After this is shaken off on a conveyor belt to form a web, a roll (smooth roll, embossing roll, etc.) kept at room temperature or at an appropriate temperature (below the melting point of polyolefin) or a felt calender is used to press the part or the entire surface to form a sheet. To This non-woven fabric consists of fibers with a very fine and complex cross-sectional structure. However, it is not preferable to set the porosity to 40% or less at the time of pressure bonding in terms of moisture permeability and breathability, and when used for the above-mentioned work clothes and protective clothes, the moisture permeability is 100 g / m ² / hr or more, that is, Pressure bonding is performed so that the porosity is 40% or more. Further, it is necessary to have flexibility from the feeling of wearing, and it is preferable that the above-mentioned polyolefin nonwoven fabric is made soft by performing a softening process.
As a measure of flexibility, pure bending value of 0.01 by KES method
A range of 0.5 gfcm ² / cm is preferred.

The basis weight of the nonwoven fabric is preferably 30 to 200 g / m ² , more preferably 40 to 100 g / m ² .
If the basis weight is less than 30 g / m ^2, it is difficult to obtain sufficient waterproofness. On the other hand, if it exceeds 200 g / m ² , flexibility will be impaired, and wrinkles or breakage will be likely to occur during production. In order to impart antistatic property to the polyolefin nonwoven fabric manufactured by the above method, antistatic processing is performed. As the antistatic agent, it is necessary to use an antistatic agent that does not reduce the water repellency and water pressure resistance of the nonwoven fabric. Such an antistatic agent has a surface tension value of 45 dyne in an aqueous solution of 1%.
/ Cm or more is required. Antistatic agents exhibiting such performance include methoxyalkyl phosphate salts, alkylalkylene oxide phosphate salts,
Oxacycloalkyl methyl phosphate salt etc. are mentioned. It is necessary to give an appropriate amount of the antistatic agent depending on the type of the antistatic agent, the molecular structure of the non-woven fabric, the surface condition, etc. However, in order to keep the surface resistance value at 1 × 10 ⁹ Ω or less, 0.1 is required. Weight% or more is required, preferably 0.3% by weight
That is all.

As a method for applying the antistatic agent, an ordinary application method can be applied, but coating method, gravure roll method,
An application method in which the antistatic agent is distributed on the surface of the nonwoven fabric by a kiss roll method, a spray method, or the like is preferable. For example, by applying 0.3 to 5% of methoxybutyl phosphate potassium to the polyethylene nonwoven fabric by the above-mentioned flash spinning method by the rotor dampening method with respect to the dry sample weight, the water repellency is 80 or more and the water pressure resistance is 500 mmH _2. It is possible to manufacture a nonwoven fabric which is O and has a surface resistance value of 1 × 10 ⁹ Ω or less.

Further, the non-woven fabric used in the present invention can be colored, and even if it is subjected to gravure printing, flexographic printing, print printing, etc., there is no problem as long as the antistatic property and water repellency are not deteriorated. Means for molding the nonwoven fabric used in the present invention as clothing is not particularly limited, such as sewing, heat sealing, and adhesive molding.

[0017]

EXAMPLES The present invention will be specifically described with reference to the following examples.
Prior to the description of the examples, methods for measuring various physical properties of the nonwoven fabric used in the waterproof and antistatic clothing of the present invention will be described.・ Antistatic property (Surface resistance measurement method) A voltage of 500 V is applied to the protective electrode from the main electrode on the surface of the sample, and the surface electrical resistivity is determined from the value of the current flowing through the protective electrode (JIS-L-1094 surface leakage) Resistance measurement
Main electrode diameter: 50 mm Protective electrode inner diameter: 70 mm). -Water repellency test (spray test) The water repellency test method (JIS-L-1092) of a textile product is used for measurement. -Water pressure resistance test It is measured by the hydrostatic pressure of Method A and Method B of the waterproofness test (JIS-L-1092) of textile products. -Moisture permeability test Method of moisture permeability test for textile products (JIS-L-1099) A
It is evaluated by the -1 method (calcium chloride method). -Surface tension value An antistatic agent is made into a 1% pure aqueous solution with distilled water (65 dyne / cm), the temperature is adjusted to 20 ° C, and then measured with a Wilhelm surface tensiometer. -Specific surface area BET method (nitrogen adsorption method) Sorptomatic 1800 manufactured by Carlo Erba Co.-Porosity

[0018]

[Equation 1]

Thickness: Measured with a load of 20 g / cm ² . In each of the examples described below, application of the antistatic agent and adjustment of the measurement sample were performed by the following methods. An aqueous solution containing an antistatic agent was applied almost uniformly to the non-woven fabric by spraying, and nipping was performed between rubber rolls having a hardness of 75 ± 5 to remove excess solution from the non-woven fabric surface.
This damp non-woven fabric is air dried and then pre-designated 20
It was adjusted in a constant temperature room of ± 2 ° C. and 40 ± 2% RH for 24 hours or more.

[0020]

[Examples 1 and 2 Comparative Examples 1 to 3] A polyethylene polymer and a solvent were discharged from a nozzle under a high temperature and high pressure condition to a low temperature and low pressure range, and the solvent was flushed to form a fibrillated reticulated fiber, which was then deposited in a wire mesh form. It is thermocompression bonded with a 130 ° C calender roll, and has a basis weight of 62 g / m ² thickness of 0.2 mm.
A polyethylene nonwoven fabric having a porosity of 68% and a specific surface area of 9.5 m ² / g was obtained. The nonwoven fabric was kneaded by a roll and had a pure bending value of flexibility of 0.13 gfcm ² / cm. Next, the non-woven fabric was treated with various antistatic agents as shown in Table 1 in various concentrations of aqueous solutions. All of these antistatic agents are mixtures of mono and bis shown in the table (about 1:
1 molar amount). Table 1 shows the results of the antistatic agent adhesion amount, antistatic property and waterproof property.

[0021]

[Table 1]

Next, the non-woven fabric processed with an antistatic agent was sewn into a form of a garment for joining and then worn, and the following items were tested. The results are shown in Table 1. -Staining property test 2 cc of hard water (surface tension value: 62 dyne, 20 ° C) is placed on an acrylic plate, and sit for 1 minute so that weight is applied to the water part at the buttocks part.

○: Water does not penetrate. ×: Water penetrates.・ Antistatic test After wearing on 100% cotton underwear, 15% 10% R
A light exercise such as radio exercises is performed for about 10 minutes in a thermostatic chamber at H, and immediately after that, a dusting test with carbon toner is performed.

○: No dust is attached at all △: Dust is slightly attached ×: Dust is severely attached As a result, the waterproof / antistatic clothing of the present invention has a high level of antistatic and waterproof properties. I knew that.

[0025]

The polyolefin nonwoven fabric used in the present invention has an unprecedentedly high level of antistatic property and waterproof property in view of antistatic property and waterproof property which are considered to be contradictory performances. Therefore, when it is used as protective clothes or work clothes for nuclear power plants, etc., it becomes a waterproof anti-static clothing having excellent performance in terms of safety, practicality and comfort.

Claims (1)

[Claims] 1. An antistatic agent having a specific surface area of 1 m ² / g or more and a porosity of 40 to 75% and a surface tension value of a 1% aqueous solution of 45 dyne / cm or more in 0.1% by weight of an antistatic agent. Non-woven fabric with more than% adhered.