JPH0987955A - Production of deodorizing continuous fiber nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a deodorizing continuous fiber nonwoven fabric excellent in melt spinnability, causing no dropping out the deodorizing agent contained therein, thus capable of effectively erasing offensive odor. SOLUTION: A resin composition comprising thermoplastic polymer (s) is incorporated and kneaded with a deodorizing inorganic compound followed by heating and melting the blend which is then extruded and spun through a spinneret, and a group of the resultant continuous filaments are taken up while being drawn by high-speed-high-pressure air from an ejector, opened, and then collected on a substrate to form a web, which is then subjected to hot press bonding, thus obtaining the objective deodorizing continuous fiber nonwoven fabric. The amount of the inorganic compound (fibrous inorganic compound predominant in magnesium silicate <2.3μm in average fiber length) to be incorporated in the resin composition is 0.5-3.0wt.% based on the total weight of the composition and the inorganic compound.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface material for sanitary materials such as a disposable diaper and a sanitary napkin, which has excellent melt spinning properties, does not drop off a deodorant, and can effectively eliminate odors. The present invention relates to a method for producing a deodorant long-fiber non-woven fabric suitable for use as a ceiling material for construction, a wall material, an absorbent sheet used in lockers and chests, and a carpet for pets.

[0002]

2. Description of the Related Art Conventionally, spunbonded nonwoven fabrics have been widely used in fields such as medical / sanitary materials, general industrial materials, and civil engineering / construction materials. Among these, in recent years, examples of disposable diapers, sanitary napkins, wipers, hospital gowns, sheets, etc. that are used in a state where they are in direct contact with the skin of the human body are rapidly increasing. Therefore, the nonwoven fabrics used for these purposes have been demanded to eliminate stains such as sweat, sebum, dead steam, dirt and the like, and eliminate the bad odor caused by these stains.

Conventionally, examples of substances that can impart deodorizing performance include activated carbon, silica gel, citric acid, metal phthalocyanine derivatives, acidic phosphates, copper compounds and chitosan. Among them, various methods have been proposed for providing a deodorant non-woven fabric in which an organic deodorant is applied to the surface of the non-woven fabric. However, such a coating type deodorant non-woven fabric can maintain its deodorant performance for a long period of time because the deodorant drops off when the deodorant coated surface comes into contact with human skin. Without it was not practical.

Further, a method of mixing chitosan with cellulose viscose and spinning it is disclosed in JP-A-5-186945. However, this method can prevent the deodorant from falling off and maintain the deodorant property stably for a long time, but in the process of melt spinning viscose, the pack life is shortened due to clogging of the pack filter, and There is a problem that yarn breakage occurs during the process of stretching the filament group, and the deodorant long-fiber nonwoven fabric cannot be stably manufactured.

[0005]

DISCLOSURE OF THE INVENTION In view of the present situation, the inventors of the present invention melt-spin a resin, take out a spun continuous filament filament group while stretching it with high-speed high-pressure air by an ejector, and open it. In the method for producing a spunbonded non-woven fabric by collecting a web on a support surface for collection and subjecting the web to thermocompression bonding, there is no clogging in a pack filter and no yarn breakage occurs. As a result of earnest research on a method capable of producing a deodorant non-woven fabric, a specific amount of a magnesium silicate-based inorganic compound having a specific average fiber length and being thermally stable is mixed in a resin composition made of a thermoplastic polymer. Therefore, the inventors have found that the above problems can be solved by using the same, and have completed the present invention. The object of the present invention is to maintain the deodorant property for a long period of time without the deodorant falling off, and to prevent yarn breakage in the drawing process and shortening of the pack life due to clogging of the pack filter. It is to provide a method for producing a fibrous nonwoven fabric.

[0006]

Means for Solving the Problem According to the present invention, an inorganic compound having a deodorant property is added to a resin composition made of a thermoplastic polymer, kneaded, and then heat-melted, extruded from a spinneret, spun, and spun. The continuous continuous fiber filament group is drawn by an ejector while being drawn with high-speed high-pressure air,
In a method for forming a web by opening and collecting on a support surface for collection, and subjecting this web to thermocompression treatment to produce a deodorant long-fiber nonwoven fabric, the average fiber length is less than 2.3 μm. The fibrous inorganic compound containing magnesium silicate as a main component of 0.5 to 3% by weight based on the total weight of the resin composition and the inorganic compound.
The method for producing a deodorant long-fiber nonwoven fabric is characterized by adding 0% by weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The deodorant which is a fibrous inorganic compound containing magnesium silicate as a main component used in the present invention is sepiolite, and examples thereof include hydrous magnesium silicate sepiolite and hydrous magnesium aluminum silicate attapulgite. You can Sepiolite means natural mineral fiber,
It is a clay mineral commonly called mountain leather, mountain cork, mountain wood, etc., and generally indicates magnesium silicate having a hydroxyl group on the surface.

The average fiber length of the fibrous inorganic deodorant used in the present invention is less than 2.3 μm, preferably 0.5-2.
0 μm. If the average fiber length exceeds 2.3 μm, the fibers fall off during melt spinning, and the filter life is apt to shorten the pack life and cause yarn breakage during drawing.

The addition ratio of the deodorant to the resin composition is 0.5 to 3.0% by weight based on the total weight of the resin composition and the deodorant. If the addition rate exceeds 3.0% by weight, the dispersibility of the deodorant tends to be poor, the yarn breakage during the drawing process increases, and the effect of the deodorant performance reaches a peak, which is uneconomical. On the contrary, if the addition rate is less than 0.5% by weight, the deodorizing performance is not sufficiently exhibited. Examples of the resin composition made of a thermoplastic polymer that can be used in the present invention include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyamide resins, etc., which are appropriately selected and used.

Among the resin compositions described above, a polyolefin resin, particularly a polypropylene resin, is preferable because it is easy to control the water content, the resin unit price is low, and it is resistant to acids, alkalis and solvents. Used. The resin composition used in the present invention is JIS K
The melt flow rate under the conditions of a temperature of 190 ° C. and a load of 2.16 kg measured by the method shown in 7210 is 20 to 20.
A range of 70 g / 10 minutes is preferable, and 30 to 60 g / 10
The range of minutes is more preferable.

When the melt flow rate is less than 20 g / 10 minutes, it is necessary to raise the melt spinning temperature, which not only causes an increase in cost, but also the produced non-woven fabric becomes hard and the texture is deteriorated, which is not preferable. On the contrary, if the melt flow rate exceeds 70 g / 10 minutes and becomes high, the occurrence of yarn breakage during drawing with high-pressure air increases, which is not preferable. The melting temperature during melt spinning is higher than the melting point of the resin by 50 to 135 ° C, preferably 60 to 120 ° C. The melting temperature during melt spinning is 50 ° C above the melting point of the resin.
At a temperature difference of less than 1, the viscosity of the resin during melt spinning is high and it is not suitable for spinning. Conversely, the melting temperature is 1 above the melting point of the resin
When the temperature is higher than 35 ° C., the temperature is separated from the melting point of the resin by too much, so that it becomes difficult to cool the resin when spinning the resin from the spinneret, and not only fusion of the fibers or breakage of the resin occurs, Is not suitable because it lowers the stability and may cause partial resin decomposition.

The water content measured by the Karl Fischer method of the resin composition before melt spinning with a melt extruder is 0.2% by weight or less, preferably 0.05% by weight or less. If the water content of the resin is more than 0.2% by weight, not only the yarn breakage during melt spinning will increase, but also in an extreme case, the resin will be decomposed, making spinning impossible. The fineness of long fibers obtained by melt spinning a resin composition comprising a thermoplastic polymer with a melt extruder is in the range of 1 to 5 denier.
If the fineness of the long fibers is less than 1 denier, the spinning conditions become strict and it becomes difficult to spin the long fibers stably. Conversely, if the fineness of the long fibers exceeds 5 denier, the fiber diameter becomes too thick. However, it is not preferable because the long-fiber non-woven fabric becomes hard and the texture is lowered.

As the basis weight of the long fiber non-woven fabric, JIS P
The weight per unit area measured by 8124 is preferably 5 to 100 g / m ² . When the basis weight is less than 5 g / m ² , the basis weight is too low and it becomes difficult to stably produce the long-fiber nonwoven fabric, which is not preferable. Conversely, the basis weight is 100 g /
When it exceeds m ² , the feel of the sheet is deteriorated, which is not preferable. In the present invention, as described above, the spun continuous filament filament group is drawn by an ejector while being drawn with high-speed and high-pressure air, opened, and collected to form a web on a support surface for collection. Then, for the purpose of imparting shape retention and strength to the nonwoven fabric, this web is subjected to thermocompression bonding, and self-bonding areas of the fibers are provided at regular intervals.

In this self-fusing zone, the long fiber web accumulated on the support is introduced between a heated uneven roll and a smooth roll, and subjected to heating and pressure treatment, thereby forming a convex portion of the uneven roll. It is formed by fusing corresponding parts. In this case, the temperature of the roll is 5 to 50 ° C., preferably 5 to 50 ° C., higher than the melting point of the resin composition constituting the long fibers used.
40 ° C. lower temperature. If the difference between the roll temperature and the melting point of the resin is less than 5 ° C., the fibers adhere to the roll during thermocompression bonding by the roll, which causes manufacturing troubles. On the other hand, if the difference between the roll temperature and the melting point of the resin exceeds 50 ° C., the formation of the self-bonding portion becomes insufficient, not only the strength of the non-woven fabric remarkably decreases, but also fuzz becomes severe, which is not suitable.

The linear pressure when the thermocompression treatment is performed with the uneven roll and the smooth roll is 10 to 80 kg / cm, preferably 2
It is 0 to 60 kg / cm. If the linear pressure is less than 10 kg / cm, the formation of the self-bonding area by thermocompression bonding becomes insufficient, and if it exceeds 80 kg / cm, a break in the fusion area occurs and the texture of the nonwoven fabric deteriorates.
It is also unsuitable as it causes a decrease in strength. As a method of forming a self-fusion area, the continuous continuous fibers that have been accumulated are introduced between an uneven roll and an ultrasonic horn, and subjected to ultrasonic treatment to form a point fusion portion corresponding to the convex portion. It is also possible.

In the present invention, the area of each self-bonding zone is adjusted in the range of 0.03 to ⁴ mm ² . If the area of the self-bonding area is less than 0.03 mm ² , the strength of the nonwoven fabric is insufficient, and conversely, if the area of the self-bonding area exceeds 4 mm ² , the nonwoven fabric becomes hard and unsuitable. The total area of the self-bonding area is 2 to 2 of the surface area of the long fiber nonwoven fabric.
It is 20 area%. If the total area of the self-bonding area is less than 2 area%, the strength is insufficient, and conversely, if the area of the self-bonding area exceeds 20 area%, the nonwoven fabric becomes hard, which is not suitable.

As described above, the present invention is suitable for thermoforming because it is thermally stable, and is thermoplastic with a fibrous inorganic compound containing magnesium silicate as a main component and having a small average fiber length as a deodorant. When a long-fiber non-woven fabric was produced by adding the mixture to the resin composition of the polymer, kneading, and further heating and melt-spinning, no yarn breakage or clogging of the pack filter occurred in the stretching process, and thus the obtained Odorable long-fiber non-woven fabric absorbs bad odors such as ammonia, hydrogen sulfide, trimethylamine, etc. very efficiently and exerts deodorizing effect, and since it is a non-woven fabric, it is extremely easy to handle, and various processing is carried out if necessary. , Hygienic materials, medical base materials, clothing base materials, household base materials, industrial base materials, etc.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following examples, all% are% by weight.
It is.

Example 1 Sepiolite (Omi Mining Co., Ltd., trade name "Miraclay P-200V") having an average fiber length of 1.1 μm was used as a deodorant inorganic compound with a melt flow rate of 50 g / 10.
0.5% of polypropylene and sepiolite based on the total weight of polypropylene, kneaded with a twin-screw kneading extruder, and then 230 at 230 ° C. in an extrusion melt spinning machine.
It is heated and melted at ℃, extruded from fine pores and spun, and the spun continuous filament filaments are drawn by an ejector while being drawn with high-speed high-pressure air, opened, and spread on a support surface for collection that is running. A web was formed by collecting and depositing. The fineness of this long fiber was 2.1 denier.
Next, the obtained web was introduced between a concavo-convex roll heated to 150 ° C. and a smooth roll, and a portion corresponding to the convex part of the concavo-convex roll was fused to give a long fiber having a basis weight of 23.5 g / m ² . A non-woven fabric was produced. The roll linear pressure at this time is 35
kg / cm, the area of the obtained self-fusion area is 0.12 m
The sum of m ² and the area of the self-bonding area was 4.0 area% of the total surface area of the nonwoven fabric.

The clogging state of the pack filter and the spinnability when the resin composition was melted by heating and spun were evaluated by the following methods. (1) Pack filter clogging status When the filter is clogged with foreign matter, the pack filter pressure rises. Therefore, if the dispersibility of the deodorant inorganic compound added to the resin composition is poor, the inorganic compound will fall off during the melt spinning in the extrusion spinning machine, clogging the filter, and increasing the pressure of the pack filter. Therefore, the difference between the pressure P ₂ of the pack filter when spinning the resin composition containing no inorganic compound and the pressure P ₁ of the pack filter when spinning the resin composition containing the inorganic compound (P ₁ -P ₂ The value of) evaluated the clogging situation. Those with a difference value of more than 5 kg / cm ² were considered to be in a clogged state. (2) Spinnability When the resin composition containing an inorganic compound was extruded and melt-spun by a spinning machine, the spinnability was evaluated by the number of yarn breakages per hour. The spinnability was determined to be good when the number of yarn breakage was 15 times / hour or less.

The deodorizing property and flexibility of the obtained long-fiber non-woven fabric were measured by the following test methods to evaluate the quality. Test method (1) Deodorant 10 g of the obtained long fiber non-woven fabric was used as trimethylamine 10
0ppm, hydrogen sulfide 100ppm, ammonia 100p
It is left for 1 hour in a polypropylene film (gas impermeable substance coating) having a capacity of 5 pm in which pm is sealed, and the residual gas concentration after each standing is measured by a gas chromatograph mass spectrometer (VG MASLAB, TR1).
0-1000), and the change rate of the concentration was calculated by the deodorizing rate from the following formula (1) to obtain, and the deodorizing property was evaluated. A deodorizing rate of 90% or more was regarded as good deodorizing property. Deodorization rate (%) = [(initial gas concentration-residual gas concentration) / (initial gas concentration)] × 100 (1)

(2) Softness The softness of the nonwoven fabric was evaluated by touching it with the hands and evaluated according to the following five grades. 5 ・ Excellent flexibility. 4 ... Flexible. 3 ... Flexibility is normal. 2 ... Slightly inferior in flexibility. 1 ・ ・ Flexibility is extremely poor.

Example 2 A long fiber was prepared in the same manner as in Example 1 except that sepiolite having an average fiber length of 1.1 μm was added as a deodorant inorganic compound in an amount of 2.5% based on the total weight of polypropylene and sepiolite. A nonwoven fabric was prepared and its quality was evaluated.

Example 3 Sepiolite (manufactured by Omi Mining Co., Ltd., trade name: Miraclay P-8) having an average fiber length of 2.0 μm as a deodorant inorganic compound
0V) was added in the same manner as in Example 1 except that 0.5% was added based on the total weight of polypropylene and sepiolite, and a long-fiber nonwoven fabric was produced, and the quality thereof was evaluated.

Example 4 A long fiber was prepared in the same manner as in Example 1 except that sepiolite having an average fiber length of 2.0 μm was added as a deodorant inorganic compound in an amount of 2.5% based on the total weight of polypropylene and sepiolite. A nonwoven fabric was prepared and its quality was evaluated.

Comparative Example 1 Sepiolite (manufactured by Omi Mining Co., Ltd., trade name: Miraclay P-1) having an average fiber length of 2.5 μm as a deodorant inorganic compound
50) was added in the same manner as in Example 1 except that 0.5% based on the total weight of polypropylene and sepiolite was added, and a long-fiber nonwoven fabric was produced, and the quality thereof was evaluated.

Comparative Example 2 A long fiber was prepared in the same manner as in Example 1 except that sepiolite having an average fiber length of 1.1 μm was added as a deodorant inorganic compound in an amount of 0.1% based on the total weight of polypropylene and sepiolite. A nonwoven fabric was prepared and its quality was evaluated.

Comparative Example 3 A long fiber was prepared in the same manner as in Example 1 except that 3.5% of sepiolite having an average fiber length of 1.1 μm was added as a deodorant inorganic compound to the total weight of polypropylene and sepiolite. A nonwoven fabric was prepared and its quality was evaluated.

Comparative Example 4 A long fiber was prepared in the same manner as in Example 1 except that sepiolite having an average fiber length of 2.0 μm was added as a deodorant inorganic compound in an amount of 0.1% based on the total weight of polypropylene and sepiolite. A nonwoven fabric was prepared and its quality was evaluated.

The obtained results are shown in Table 1.

[0031]

[Table 1]

As is clear from Table 1, the present invention hardly produces clogging or yarn breakage in the pack filter during melt spinning, has excellent spinnability, and is capable of stably producing a long fiber nonwoven fabric, The obtained non-woven fabric, with respect to the malodorous component,
Has excellent deodorant properties. On the other hand, even if the addition rate of the deodorant inorganic compound is appropriate, if the average fiber length is too long (Comparative Example 1), the flexibility of the nonwoven fabric is normal and there is no problem, and the deodorant property is excellent. When the filter is clogged, the differential pressure is 9 kg / cm ² , yarn breakage occurs frequently, and the operability is poor.

On the other hand, even if the average fiber length of the deodorant inorganic compound used is within the proper range, if the addition rate is too low (Comparative Examples 2 and 4), clogging or yarn breakage in the pack filter may occur. Almost no generation occurs, and the operability is excellent, but sufficient deodorant properties cannot be imparted to the obtained nonwoven fabric. When the addition rate of the deodorant inorganic compound is too large (Comparative Example 3), the non-woven fabric is excellent in deodorizing property, but the packing filter often causes clogging and yarn breakage, resulting in poor spinnability and stability. Therefore, it is impossible to manufacture a long-fiber nonwoven fabric.

[0034]

Industrial Applicability As described above, according to the present invention, the spinning property and operability are remarkably excellent, and the obtained nonwoven fabric is in the form of a sheet, so that it is easy to handle, and the deodorizing property of the malodorous gas is extremely excellent. An effect of providing a method for manufacturing a non-woven fabric is provided.

Claims (1)

[Claims] 1. A resin composition comprising a thermoplastic polymer, an inorganic compound having deodorant performance is added and kneaded, then melted by heating, extruded from a spinneret, spun, and spun into a continuous long fiber filament group. It is drawn by an ejector while being drawn with high-speed and high-pressure air, opened, and collected to form a web on the support surface for collection, and the web is subjected to thermocompression bonding to produce a deodorant long-fiber nonwoven fabric. In the method, a fibrous inorganic compound having an average fiber length of less than 2.3 μm and containing magnesium silicate as a main component is added in an amount of 0.5 to 3.0% by weight based on the total weight of the resin composition and the inorganic compound. A method for producing a deodorant long-fiber non-woven fabric.