JPH07275174A - Non-woven fabric wiper - Google Patents

Abstract

PURPOSE:To provide a wiper which is soft in hand, has an excellent fit to an object and wiping away property and is capable of removing hydrophilic stains without generating dust pickup although this wiper is composed of synthetic fibers. CONSTITUTION:This wiper is composed of a melt blown non-woven fabric consisting of a polybutyrene terephthalate contg. >=0.1 to <=0.3wt.% sodium alkyl allyl sulfonate or sodium alkyl sulfonate. The average fiber diameter of the fibers constituting this non-woven fabric is >=1 to <=10mum, the METSUKE (unit) weight is >=10 to <=160g/m<2>, the apparent density is >=0.1 to <=0.6g/cm<3> and the thermal fusion area rate is >=10 to <=30%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper made of a polybutylene terephthalate meltblown nonwoven fabric which is excellent in fit property, wiping property and long-lasting hydrophilicity.

[0002]

2. Description of the Related Art Conventionally, as wipers, non-woven fabrics made of natural fibers such as cotton and pulp, raised fabrics, and woven fabrics, knitted fabrics and non-woven fabrics made of synthetic fibers have been widely used. Among these, short-fiber non-woven fabrics made of natural fibers such as cotton and pulp have excellent hydrophilicity, soft texture, and good fit to an object, but the fibers constituting this non-woven fabric are thick. Therefore, there was a problem that the fit surface was rough and the wiping property was poor. Moreover, when stains are removed using this wiper made of natural fibers, the fibers are likely to be cut or fallen off, which itself becomes a source of dust, so it is necessary to maintain a highly clean atmosphere in the room. It could not be used in the manufacturing site of certain electronic materials such as semiconductors, precision equipment such as cameras, and medical equipment.

In order to solve these problems, wipers made of synthetic fiber filament woven fabrics, knitted fabrics, etc. have been proposed.

However, since the conventional synthetic wiper made of synthetic fiber has high strength, the synthetic fiber has a high strength, so that the fiber is cut off when dirt is removed and becomes a source of dust like a short fiber non-woven fabric wiper made of natural fiber. On the other hand, on the other hand, it has a problem that it absorbs the surrounding dust and becomes a source of dust because it is highly hydrophobic and easily generates static electricity. Also, the constituent fibers are thick and the fitting surface becomes rough. Therefore, problems such as poor wipeability have not been solved. Further, since the synthetic fibers are hydrophobic, there is a drawback that they are inferior in wiping-off property against hydrophilic stains.

Therefore, in order to impart hydrophilicity and antistatic property to synthetic fibers, Japanese Patent Publication No. 63-25701 and Japanese Patent Publication No.
-5305 proposes a non-woven wiper laminate treated with a surfactant, and JP-A-1-149482 proposes a wiping cloth containing an antistatic fiber or a conductive fiber in an ultrafine fiber sheet. JP-A-2-28
9220 proposes a cloth for wiping cloth containing polyoxyalkylene glycol and a metal salt derivative of sulfonic acid.

However, although these wipers are recognized as having an effect of improving the hydrophilicity and antistatic property such as a dust adsorption preventing effect due to static electricity or a wiping-off effect against hydrophilic stains, they satisfy all the requirements required for the wiper. However, the performance as a wiper was not fully satisfactory.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to be composed of synthetic fibers, but does not cause adsorption of dust, has a soft texture, is excellent in fit and wipeability with respect to an object, and has hydrophilic stains. The present invention also provides a non-woven wiper that can be sufficiently removed.

[0008]

The present invention for solving the above problems has the following constitution.

That is, a melt blown nonwoven fabric made of polybutylene terephthalate containing 0.1% by weight or more and 3.0% by weight or less of sodium alkylallyl sulfonate or sodium alkyl sulfonate, the average fiber of the fibers constituting the nonwoven fabric. Diameter is 1 μm or more and 10 μm
Below, the basis weight is 10 g / m ² or more and 160 g / m ² or less, and the apparent density is 0.1 g / cm ³ or more and 0.6 g / cm
A nonwoven fabric wiper comprising a nonwoven fabric having a heat-fusing area ratio of ³ or less and 10% or more and 30% or less.

The present invention is a wiper composed of a non-woven fabric obtained by a melt blow spinning method of a specific polymer, and the fiber diameter of the ultrafine fibers constituting the non-woven fabric, the weight of the non-woven fabric, the apparent density, and the heat-sealing area ratio. It has been found that in a specific range, a wiper having a soft texture, an excellent fit property, and a high wiping property can be obtained.

The fibers constituting the nonwoven fabric wiper of the present invention are composed of sodium alkylallyl sulfonate or polybutylene terephthalate containing 0.1% by weight or more and 3% by weight or less of sodium alkylsulfonate. By using the melt-blown nonwoven fabric made of this specific polybutylene terephthalate, the nonwoven fabric wiper of the present invention can impart excellent antistatic property and high hydrophilicity and long-lasting hydrophilicity, and fiber cutting and It does not cause dust adsorption. Therefore, it is useful as a high-performance wiper excellent in hydrophilic dirt removal performance that can be used in the manufacturing sites of electronic materials such as semiconductors, precision machines such as cameras, and medical equipment.

The polybutylene terephthalate used in the present invention may be a polyester polymer having butylene terephthalate as a main repeating unit, and preferably has a number average molecular weight of 5,000 to 20,000. Various additives that are usually used (a light stabilizer, an antistatic agent, a stabilizer, etc.) within a range in which the effect of the present invention does not exist
May be included.

In the present invention, sodium alkylallylsulfonate contained in polybutylene terephthalate is an anionic surfactant generally represented by the following formula (I) or (II).

[0014]

[Chemical 1]

[Chemical 2] Further, in the present invention, sodium alkyl sulfonate contained in polybutylene terephthalate is an anionic surfactant generally represented by the formula (III).

[0015]

[Chemical 3] These have high heat resistance so that they are not thermally decomposed even when added to a molten butylene terephthalate polymer, and have excellent properties such as hydrophilicity and imparting an antistatic effect. It is important that the content is 0.1% by weight or more and 3% by weight or less. If the content is less than 0.1% by weight, the antistatic property and hydrophilicity are low, and static electricity is easily generated, so that the surrounding dust is adsorbed and becomes a dust generation source. Also, the wiping property is low.
If the content exceeds 3% by weight, the strength of the wiper decreases. It is preferably in the range of 0.2% by weight or more and 2% by weight or less.

The nonwoven fabric wiper of the present invention is obtained by the melt blow spinning method. A known method can be adopted as the melt blow spinning method. For example, there is a method in which a molten butylene terephthalate polymer is discharged as a continuous fiber from a nozzle and is blown onto a net-shaped moving and collecting surface together with high-speed heated compressed air to form a nonwoven fabric.

In the present invention, the fibers constituting the meltblown nonwoven fabric have an average fiber diameter of 1 μm or more and 1 or more.
It is important to make it 0 μm or less. Average fiber diameter is 1
If it is less than μm, floating cotton is generated during melt blow spinning, which deteriorates the workability and the quality of the wiper. If it exceeds 10 μm, the rigidity of the constituent fibers is too strong, and the texture becomes hard, resulting in poor fit and wipeability. Further, in order to secure the strength of the wiper and to make it soft and excellent in the fitting property and the wiping property, it is preferable that the average fiber diameter is in the range of 2 μm or more and 6 μm or less.

The average fiber diameter referred to here is 100 from a 1000 times magnified photograph by a scanning electron microscope.
The fiber diameter is read, and it is the average value.

Further, it is important that the nonwoven fabric constituting the present invention has a basis weight of 10 g / m ² or more and 160 g / m ² or less. From the viewpoint of ease of use as a wiper and cost, it is preferably 20 g / m ² or more and 140 g / m ² or less.

Further, it is important that the nonwoven fabric constituting the present invention has an apparent density of 0.1 g / cm ³ or more and 0.6 g / cm ³ or less. Apparent density is 0.1g / c
If it is less than m ³ , the fibers are less entangled with each other and the strength of the non-woven fabric is lowered to deteriorate the operability and the quality of the wiper. 0.
If it exceeds 6 g / cm ³ , entanglement between fibers becomes excessive,
The texture becomes hard and the fit and wiping performance are deteriorated. From the viewpoint of ensuring the strength of the wiper, softer and more excellent in fitting and wiping off the object, the apparent density is 0.2 g / cm ³ or more and 0.4 g /
It is preferably in the range of ³ cm ³ or less.

In the non-woven fabric constituting the present invention, it is important that the fibers are partially heat-sealed. Preferably, it is desirable that the surface of the non-woven fabric is unevenly shaped.

The area of the part to be partially heat-sealed is 10% or more 3 in terms of the area ratio to the total area of the nonwoven fabric.
It is important that the content is 0% or less, preferably 15% or more and 25% or less. When the heat-sealing area ratio is less than 10%, the heat-fixed portions of the fibers are small, and the wear durability deteriorates. If the heat-sealing area ratio exceeds 30%, the fibers will be in the form of a film, and the texture will be rough and hard, resulting in poor fit and wipeability.

Means for heat-sealing the nonwoven fabric constituting the present invention include means such as hot embossing, ultrasonic wave or high frequency. The heat embossing method is preferable from the viewpoint of cost, practicality, versatility, etc. By this method, the fibers can be partially heat-adhered to each other, and at the same time, the surface of the nonwoven fabric can be formed into an uneven shape.

Further, in the nonwoven fabric wiper of the present invention, the object is secondarily contaminated by sodium alkylallyl sulfonate or the like eluted from the wiper when the hydrophilic stain is removed, resulting in a defect in the manufacturing process of electronic materials such as semiconductors. From the viewpoint of making it difficult to pass through, it is preferable that the weight loss rate when washed with water is 0.3% by weight or less. On the other hand, from the viewpoint of obtaining excellent antistatic property and hydrophilicity, making it difficult to generate static electricity and adsorbing surrounding dust, and improving the wiping property, the weight reduction rate when washed with water is 0.01 % Or more is preferable. More preferably, 0.02 wt% or more 0.2
It is preferable to set it in the range of 5% by weight or less.

[0025]

EXAMPLES The present invention will be described in more detail below with reference to examples.

The characteristic values in the examples are obtained by the following method.

<Average fiber diameter> 100 fiber diameters were read from a 1000 times magnified photograph by a scanning electron microscope, and the average thereof was taken as the average fiber diameter.

<Handle> JIS-L1096A method (45
° The cantilever method) was used as the index of the texture for the vertical and horizontal total values. The smaller the total value, the softer the texture.

<Hydrophilicity> The water absorption height according to the JIS-L1096B method (Bayrec method) was used as an index of hydrophilicity. The higher the water absorption height, the higher the hydrophilicity.

<Hydrophilicity after washing with water> After being washed in running tap water for 5 minutes while shaking, it is dried at room temperature on a filter paper,
The water absorption height was measured by the JIS-L1096B method (Bayrec method) and used as an index of hydrophilicity after washing with water. The higher the water absorption height, the higher the hydrophilicity after washing with water.

<Weight reduction rate after washing with water> A wiper stored in a room at room temperature of 20 ° C. and a relative humidity of 60% RH for 24 hours was weighed and then washed with running tap water for 5 minutes while shaking. Was dried at room temperature on filter paper. Weight was measured under the same conditions as before water washing, and the ratio of the reduced weight to the weight before water washing was determined as the weight loss rate (%) after water washing.

<Wipeability> A drop of silicone oil was dropped on a glass plate with a syringe, and wiped off with a wiper attached to a cylinder having a diameter of 45 mm under a load of 1000 g at a speed of 1 m / min. After wiping, the toner was sprinkled, and then the excess toner was removed with a compressed air of 1 kg / cm ² , the residual toner was transferred to cellophane tape, and the residual amount was compared to determine the grade, which was used as an index of the wiping property.

<Antistatic property> The friction band withstand voltage was measured by the JIS-L1094B method and used as an index of antistatic property. The lower the charged voltage, the better the antistatic property and the less the generation of static electricity.

<Dust generation property> Measured by JIS-B9923 (6) (shaking method), the number of particles of 0.5 μm or less in one cubic foot was used as an index of dust generation property. The smaller the number, the better the dust generation.

Example 1 75 parts of polybutylene terephthalate having an average molecular weight of 19,000 and 25 parts of sodium alkylallylsulfonate were added and mixed, and then melt-mixed at 280 ° C. using a twin-screw extruder to obtain an alkyl. A polybutylene terephthalate master chip containing 25% by weight of sodium allylsulfonate was obtained.

Further, polybutylene terephthalate 96
And 4 parts of the master chip were mixed with a Hensyl mixer to prepare a polybutylene terephthalate chip containing 1% by weight of sodium alkylallylsulfonate. Next, the chips were dried with hot air at 140 ° C. for 4 hours, and then the dried chips were used for spinning temperature 285 ° C. and heating air temperature 28.
Melt blow spinning was performed under the conditions of 5 ° C., heated air pressure 1.2 kg / cm ² , polymer discharge rate 38.5 g / min, average fiber diameter 2.2 μm, basis weight 40 g / m ² , apparent density 0.3 g / cm. ^Three non-woven fabrics were produced.

Two pieces of this non-woven fabric are overlaid, and the processing temperature is 1
Embossing was performed under the conditions of 40 ° C. and a processing pressure of 10 kg / cm ² to obtain a nonwoven fabric wiper having a heat-sealing area ratio of 15%.

Table 1 shows the evaluation results of the feel, hydrophilicity, hydrophilicity after washing with water, weight reduction rate after washing with water, wiping property, antistatic property, and dusting property of this wiper.

Example 2 Melt-blow spinning was carried out under the same conditions except that the surfactant added to polybutylene terephthalate in Example 1 was changed to sodium alkylsulfonate, the average fiber diameter was 1.9 μm, and the basis weight was 4
A non-woven fabric of 0 g / m ² and an apparent density of 0.3 g / cm ³ was produced.

Two pieces of this non-woven fabric are overlaid, and the processing temperature is 1
Embossing was performed under the conditions of 40 ° C. and a processing pressure of 10 kg / cm ² to obtain a nonwoven fabric wiper having a heat-sealing area ratio of 15%. The texture of this wiper, hydrophilicity, hydrophilicity after washing with water,
The weight loss rate after washing with water, the wiping property, the antistatic property, and the dust generation property were evaluated, and the results are shown in Table 1.

[Comparative Example 1] The heating air pressure was 1.2 kg /
was changed from cm ² to 0.6 kg / cm ² is subjected to melt-blow spinning under the same conditions as in Example 1, the average fiber diameter 12.1Myuemu, basis weight 40 g / m ^2, an apparent density of 0.3 g / cm ³ The non-woven fabric of was produced.

Two pieces of this non-woven fabric are overlaid, and the processing temperature is 1
Embossing was performed under the conditions of 40 ° C. and a processing pressure of 10 kg / cm ² to obtain a nonwoven fabric wiper having a heat-sealing area ratio of 15%. The texture of this wiper, hydrophilicity, hydrophilicity after washing with water,
The weight loss rate after washing with water, the wiping property, the antistatic property, and the dust generation property were evaluated, and the results are shown in Table 1.

[Comparative Example 2] In Example 1, melt-blow spinning was carried out under the same conditions with polybutylene terephthalate alone without adding sodium alkylsulfonate. The average fiber diameter was 2.1 µm, the basis weight was 40 g / m ² , and the apparent density was Formed a non-woven fabric of 0.3 g / cm ³ .

Two sheets of this non-woven fabric are superposed, and the processing temperature is 1
Embossing was performed under the conditions of 40 ° C. and a processing pressure of 10 kg / cm ² to obtain a nonwoven fabric wiper having a heat-sealing area ratio of 15%. The texture of the wiper, hydrophilicity, hydrophilicity after washing with water,
The weight loss rate after washing with water, the wiping property, the antistatic property, and the dust generation property were evaluated, and the results are shown in Table 1.

[Comparative Example 3] In Comparative Example 2, a 1% by weight aqueous solution of dialkylsulfosuccinic acid ester salt was sprayed onto the wiper after embossing, and then it was heated to 80 ° C.
And dried for 1 hour to obtain a wiper having 0.3% by weight of the above compound attached.

The texture, hydrophilicity, hydrophilicity after washing, weight reduction rate after washing, wiping property, antistatic property, and dusting property of the wiper were evaluated, and the results are shown in Table 1.

[0047]

[Table 1] As is apparent from Table 1, the wipers of Examples 1 and 2 of the present invention, by containing sodium alkylallyl sulfonate or sodium alkyl sulfonate, have a soft texture and are excellent in hydrophilicity and wiping-off property. It was Further, it had excellent dust-generating property and antistatic property, and particularly had extremely excellent hydrophilicity (hydrophilicity durability) after washing with water, and had a well-balanced performance as a whole.

On the other hand, the wiper of Comparative Example 1 was inferior in texture, wiping property and the like because the average fineness of the nonwoven fabric was large. Further, the wiper of Comparative Example 2 did not contain sodium alkyl sulfonate and the like, and thus was inferior in performance such as texture, hydrophilicity and wiping-off property. Further, the wiper of Comparative Example 3 was obtained by applying a surfactant agent by post-processing,
Although it had excellent hydrophilicity, it had a slightly hard texture and poor fit, and also had poor hydrophilic durability.

[0049]

EFFECT OF THE INVENTION The nonwoven fabric wiper of the present invention has a soft texture, excellent fit to an object, and high wipeability. Moreover, polybutylene terephthalate contains at least sodium alkylallyl sulfonate or sodium alkyl sulfonate, imparts antistatic property and high hydrophilicity and its hydrophilic durability, does not adsorb dust, and is hydrophilic. Enables removal of sexual stains.

Therefore, the wiper is useful at the manufacturing site of electronic materials such as semiconductors and precision equipment such as cameras, which are required to maintain a highly clean atmosphere in the room.

Claims (2)

[Claims] 1. Sodium alkylallyl sulfonate or sodium alkyl sulfonate 0.1 wt% or more 3
A melt-blown non-woven fabric comprising polybutylene terephthalate in an amount of up to 10% by weight, wherein the fibers constituting the non-woven fabric have an average fiber diameter of 1 μm or more and 10 μm or less, a basis weight of 10 g / m ² or more and 160 g / m ² or less, and an apparent density of 0. .1g / cm ³ or more 0.6 g / cm ³ or less, a nonwoven fabric wiper thermally fused area ratio is equal to or of 10% or more and 30% or less in a non-woven fabric. 2. The non-woven fabric wiper according to claim 1, wherein a weight reduction rate by washing with water is 0.01% by weight or more and 0.3% by weight or less.