JPH01104867A - Extremely fine fiber nonwoven fabric - Google Patents

Abstract

PURPOSE: To prepare a nonwoven fabric of ultrafine fibers excellent in abrasion resistance, dust resistance, moisture absorbing properties and air permeability, and useful as a sterilizing wrapping material or the like by placing an ultrafine- fiber web layer between two web-layers of long-yarn cellulose fibers, and integrally entangling fibers of every layer with each other. CONSTITUTION: A web layer C consisting of ultrafine fibers 2 is placed between two web layers B and D consisting of cellulose fibers 1, 1', 1", 1''' of long fibers or relatively long fibers, and the laminated layers are placed on a 100-mesh screen, thin ejecting water streams of high pressure are ejected from the upper side to treat the laminated layers, and at the same time, suctioning is applied from the lower side of the screen to integrally entangle fibers constituting each web layer with fibers constituting the other web layers. Thus, the objective nonwoven fabric is obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a three-layer ultrafine fiber nonwoven fabric.

More specifically, it relates to an ultrafine fiber nonwoven fabric having a three-layer structure consisting of two web layers made of cellulose fibers and a web layer made of ultrafine fibers arranged between the two web layers.

[Prior Art and Problems to be Solved by the Invention] The present invention is constructed by treating an aggregate of fibers made of wood pulp and synthetic organic fibers with a thin columnar jet of water having an Olyce supply pressure of at least 6900 Kpm. Japanese Patent Application Laid-Open No. 59-94659 discloses a method for obtaining a Snowsun lace nonwoven fabric by intertwining the fibers. This nonwoven fabric is mainly suitable for medical applications (uses that take advantage of its bacterial barrier properties).

However, this nonwoven fabric cannot be used as a packaging material that is sterilized.
Plasticizers, stabilizers, etc. contained in synthetic fibers may be extracted during steam sterilization and appear on the fiber surface. Many of these plasticizers and stabilizers are harmful to the human body, which poses a problem. Furthermore, when sterilizing with E, O, G (ethylene oxide gas), synthetic fibers absorb much more than cellulose, resulting in residual E, 0. There is a problem that it takes a long time to leave the product in order to reduce the amount of G.

In addition, a nonwoven fabric in which a layer of hydrophobic fine fibers is sandwiched between two layers of a composite material consisting of a low melting point component material and a high melting point component material, and is fused and integrated at a temperature lower than that of the high melting point material is disclosed in JP-A-Sho. 6
It is disclosed in Japanese Patent No. 2-104954 and is said to be suitable for sterile packaging materials.

However, since this composite nonwoven fabric is heat-sealed at 135°C to 145°C, low melting point components may harden during steam sterilization, and plasticizers, stabilizers, etc. contained in the fibers may be extracted during steam sterilization.
There are problems such as coming out on the surface of the fibers.

In addition, in the electronics field, the two-layer nonwoven fabric of wood pulp and organic synthetic fiber disclosed in JP-A No. 59-94659 has a fibrillated wood pulp layer on the surface, so it is highly absorbent. Although the liquid properties are good, fiber fuzz and falling fibers are likely to occur due to wear and friction.

Therefore, there is a problem in that it is still unsatisfactory for use in clean rooms with high cleanliness.

The present invention solves the above-mentioned problems of the conventionally known nonwoven fabric of this type, and although it is a nonwoven fabric mainly composed of cellulose fiber web, it has high lint-free property, abrasion resistance, and excellent water absorption and bacteria barrier. The purpose of the present invention is to provide a nonwoven fabric having characteristics such as elasticity.

[Means for solving problems]

The foregoing object of the present invention is to provide a web layer consisting of two web layers consisting of long fibers or cellulosic fibers having a relatively long fiber length, and a web layer consisting of ultrafine fibers disposed between the two web layers. This is achieved by an ultrafine fiber nonwoven fabric having a three-layer structure, characterized in that the fibers constituting each web layer of the nonwoven fabric are integrally intertwined with the fibers constituting other web layers. Ru.

That is, in the nonwoven fabric according to the present invention, cellulose fibers are selected from which impurities are not extracted during steam sterilization, and the cellulose fibers have an extremely low Young's modulus in a wet state, and have the characteristic of being easily moved by water flow and easily entangled with other fibers. Focusing on this point, the lint dropout from the ultrafine fiber web forming a dense layer is stopped by sandwiching the web between the front and back sides with a cellulose fiber web. Furthermore, the entire structure is integrated by intertwining the fibers.

The three-layer ultrafine fiber nonwoven fabric of the present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a diagram schematically showing the state of the ultrafine fiber nonwoven fabric of the present invention before entanglement. In FIG. 1, ■ and O are web layers made of cellulose fibers, and ■ is a web layer made of ultrafine fibers.

FIG. 2 is a schematic diagram showing an enlarged cross section of the ultrafine fiber nonwoven fabric of the present invention (magnification: about 60 times).

In Figure 2, ■ and ■ are web layers made of cellulose fibers, and ■ is a web layer made of ultrafine fibers. These three web layers are stacked in a sandwich shape, and the fibers are intertwined with each other. An organization is formed. A part 1' of the constituent fibers of the web layer made of cellulose fibers 1 sticks between the ultrafine fibers 2 of the web layer O made of ultrafine fibers 2, and a part of them bends in all directions and intertwines with the ultrafine fibers 2. are doing. Furthermore, some fibers 11
penetrates the web layer O made of cellulose fibers, and some of them are bent in all directions and intertwined with the cellulose long fibers 1''.

Alternatively, the cellulose fibers may be inserted from both sides to another web layer, entwined with and penetrated from both sides, and then inserted into the opposite web layer of cellulose fibers, thereby integrating the nonwoven fabric.

The integration of the ultrafine fiber nonwoven fabric of the present invention can be evaluated by measuring the peel strength.

The microfiber nonwoven fabric of the present invention having such a structure can be used as sterilizable packaging materials that require high lint-free properties, abrasion-resistant strength, and excellent bacterial barrier properties, and for use in clean rooms with high lint-free properties and resistance. It can be usefully used in wipers that require high abrasion strength and excellent water absorption.

The degree of integration is such that, for example, when the nonwoven fabric according to the present invention is used in the wiping wipe 9-, each layer will not peel off during bending or wiping during use.

The cellulose fiber web layer used in the present invention is a web made of either regenerated cellulose fibers such as cuproammonium rayon or piscose rayon, or natural cellulose fibers such as cotton, and has a fiber length of 205 m or more, preferably 281 m or more. It is a short fiber having a long length, and more preferably, one consisting essentially of continuous long fibers may be used. When the fiber length is less than 20+s, the abrasion resistance and lint-free properties targeted by the present invention cannot be achieved.

The cellulosic fiber wet layer is, for example, a web formed by aligning fibers with a card, a paper-like web made by wet papermaking, or a wet horn 9 nonwoven fabric.
It is sufficient if the constituent fibers are resistant to water flow.

Further, the cross section of the fibers may have an irregular shape such as a triangle or a square shape.

Next, the ultrafine fiber web layer is made of Ilyamide, ? Riester,
Synthetic polymers such as polyacrylonitrile and polypropylene or their copolymers, and fibers such as cugraammonium rayon and viscose rayon, whose thickness is 0.
．． Fibers of 6d or less are used. Special microfibers include fibrillated fibers, pulp, linters, and other beaten products of natural fibers, and bulb-like particles of synthetic polymers.

The length of the ultrafine fibers is not particularly limited, but
A length of 2 m or more is suitable for loops and the like.

If the length is less than 2 m, the problem arises that the abrasion resistance and lint-free properties targeted by the present invention cannot be achieved. More preferably 5m
The above is preferable. In addition, if the fiber thickness K is 0.6 d or more, the problem arises that the bacteria barrier properties targeted by the present invention cannot be achieved.

In the case of synthetic fibers, a web can be formed by spinning fibers with uniform fineness by melt spinning.

In the case of cugraammonium rayon, po and ld fibers can be spun by wet spinning.

(Refer to Japanese Unexamined Patent Publication No. 51-70311.) In addition, the beaten fibers may be distributed from G, 01d to 2d, and the average denier thereof should be 0.6d or less.

If the fiber is 0.6 d or more, the bacteria barrier properties will be poor as described above, and it is more preferable to use fibers with a diameter of 0.3 d or less.

The basis weight of the ultrafine fiber web layer is formed in the range of 6 to 50 Jil/m". If it is less than 6117 m", the bacteria barrier property will be poor, and if it is more than 5017 m", it will be too dense and the breathability will be poor. The more preferable range is 8.
~40#/m''.

The ultra-fine fiber web layer can be formed into a web by spinning, cutting and carding using a normal melt spinning method, or formed into a web by spinning using a melt blow spinning method, or by wet spinning recycled fibers. It is possible to use a paper formed into a web, or a paper made by beating natural fibers.

The ultrafine fiber nonwoven fabric of the present invention has the above-mentioned ultrafine fiber web layer sandwiched between cellulose long fiber web layers in a slant-like shape, laminated, and integrally intertwined. This provides properties such as wear resistance, lint-free properties, bacterial barrier properties, and water absorption.

Next, a method for manufacturing the ultrafine fiber nonwoven fabric of the present invention will be explained.

When using a cellulose-based fibrous web, for example, a web made of cuglaanthonium rayon, this web has a structure formed by self-adhesion and light entanglement of the fibers, and can be rearranged by water flow, but is free from other fibers. When using a web made of PVA, CMC, or the like, it is preferable to use a web whose state is maintained using a water-soluble adhesive such as PVA or CMC.

Next, a web ribbon made of an appropriate type of ultra-fine fiber.

Three layers are laminated with the ultra-fine fiber que f sandwiched between them. At this time, the webs manufactured in different manufacturing processes may be laminated and manufactured in an offline process, or the processes for manufacturing each web may be combined. For example, a process for manufacturing a regenerated fiber spunmend nonwoven fabric using a wet method and a process for manufacturing a melt-blown nonwoven fabric may be combined.

As shown in Figure 1, a web made of ultrafine fibers is laminated between two layers of cellulosic long fiber webs, and this is placed on a screen. A thin stream of high-pressure water is sprayed from above. Alternatively, the web may be reversed and subjected to water jet treatment. The mesh size of the screen is usually about 200 to 100. The jet pressure of the jet water stream is usually selected to be 25 kg/cm" or higher, more preferably 30 kgF/cm" or higher.

If it is less than 25 kg/an'', a satisfactory wet strength is often not obtained. After the treatment, it is dried to obtain an ultrafine fiber nonwoven fabric.

The present invention utilizes the property that when the fibers constituting the cellulosic fiber web layer are wetted, they become fibers with an extremely low Young's modulus and are easily moved by water flow. As a result, the cellulose fibers are inserted into the ultra-fine fiber web layer and entwined with the fibers, and also penetrated through the ultra-fine fiber web layer and inserted into the cellulose fiber web layer on the opposite side.
It entangles the fibers and becomes intertwined with them.

If the web layer is further inverted and subjected to the water jet treatment described above, a phenomenon similar to that described above will occur, increasing the chance of fiber entanglement, and the fibers will become intertwined in one layer.

〔Example〕

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

Prior to describing the examples, the definitions and measurement methods of characteristic values used in the examples will be collectively shown.

◎Measurement: Take three samples of 250 x 250 ■ from the samples in the standard state, and after reaching a moisture equilibrium state, weigh them and calculate the average value as ff (F/m”) per unit area. Expressed as

◎Water absorption rate: Take three test pieces of 14.5 x 2.2 cW1 from the sample, one each in the vertical and horizontal directions, support them at a constant height above a beaker containing Hemacell at 20 ± 2 ° C, and clean them vertically. , stop by clicking. Next, the Hemacel was brought close to the test piece, and the water absorption height (-) of the Hemacel 1 minute after contact was measured, and the average value (,,) is expressed.

◎Water absorption: Cut the sample into 110m x 10 pieces and measure the weight (
Wl), sandwich this sample between 10 mesh wire mesh and soak it in Hemacel solution for 5 minutes. Next, leave it on a wire mesh for 5 minutes, pick it up with tweezers for 30 seconds to remove excess hemacel, and weigh it (Wl).

Expressed in water absorption capacity.

◎Strong elongation: Measured according to JIS-1068. Strength (ky15cIn@), elongation (%) table b-t.

◎Abrasion resistance: Sungle in standard condition, width 25m x length 25
0m+ with a character type bending friction tester (manufactured by Takasu Seisakusho).
Friction was performed under the conditions of a load of 200g and 50 frictions. After rubbing, sample 25x25
Accurately collect approximately 21 small pieces of ■, and use an ultrasonic cleaner (Yamato).

B220H) filled with 250cc of water and washed for 15 minutes.
After removing the sample piece, the material that falls off is collected on black paper and dried.

After adjusting the humidity, measure the weight using a microbalance.

The more lint, the worse the wear resistance. I rate it as

◎ Bacterial resistance: Under the flow of monodisperse particles under certain conditions, the upstream pumping and downstream concentrations of the test specimen are measured simultaneously with two detectors to determine the dustproof rate (嗟). As monodisperse particles, stearic acid aerosol with an average diameter of 0.3 μm was used. The flow rate was set to 2.1 erll/B 6 C1, and the measurement time was 1 minute. The measuring device is 5IBATA DigitalDus
tIngieator Model AP-632 was used.

Dustproof rate (9k) = (IDz/I)+)X10
0DI; Upstream photo counter D2; Downstream photo counter The higher the dust resistance rate (chi), the better the bacterial barrier property.

◎Peel strength: Measured according to JIS-1068.

Strength (15t0M width) Example 1 A web made of copper ammonia cellulose fibers (copper ammonia rayon) continuous filaments (single thread 1.5 d) according to the regenerated fiber spunbond nonwoven fabric manufacturing method described in Japanese Patent Publication No. 52-6381. was manufactured. The basis weight is 81/l
n” + 10117 m2 was manufactured.

Separately, a web made of ultrafine polyester fibers was produced according to the melt blowing spinning method described in JP-A-51-67411.

The single yarn fineness is 0.05d, and the scale (t 51/7m2
．． 6117m", 81/m", 1211/m"
, 2097 m'' was manufactured.

Next, the next ultra-fine fiber web was sandwiched between the previous two layers of the web and laminated into three layers, placed on a 100-mesh screen, and treated by spraying a high-pressure thin jet of water from above. . At the same time, suction was drawn from the bottom of the screen. The web layer was also reversed and subjected to the water jet treatment described above. The processing conditions are shown below.

Orifice diameter 0.15■φ Processing density 30 ho 111 / cIIIX
After the 5 times treatment pressure: 30 kII/α2 treatment speed: 5 m/min, the sample was dried in a drier to obtain an ultrafine fiber nonwoven fabric.

Table 1 shows the combinations of webs and the characteristic values of the obtained microfiber nonwoven fabrics.

As can be seen from Table 1, the basis weight of the ultrafine fiber web is 517 m.
” has a dustproof rate of 2.2 mm, which is much lower than the conventional product's 10.1 rate, and it can be seen that if it is 6Ii/m2 or higher, it can be manufactured at the same level as the conventional product or even higher. .

Furthermore, these products of the present invention have water absorption properties and wet strength close to those of conventional products. It should be noted that the basis weight of the ultrafine fiber web was selected to be 20g/m2, and the overall basis weight was 4.
09/m'' showed a dustproof rate of 46.0%, which was four times better than the conventional product, and it can be said that the product of the present invention is thin and has excellent bacteria barrier properties.

Furthermore, it can be seen that the wear resistance of the product of the present invention is about three times better than that of the conventional product after wear.

In addition, the peel strength is such that when used in a wiper for wiping, each layer will not peel off during bending or wiping during use.

Furthermore, a web made of copper ammonia rayon continuous filaments with a basis weight of 1017 m'' and a web made of ultrafine polyester fibers with a basis weight of 2017 m'' were selected, and among these, the copper ammonia rayon web was dyed under the following conditions.

4 Dyeing and dyeing of copper ammonia rayon web; Ka
yarus 5upra Red 6BL (Japanese Gunpowder K
K product) Dyeing; 3 towf Bath ratio 1:50 Temperature rise: 30 minutes Room temperature to 90°C 90°C Wash with water for 45 minutes;
Color fixing for 5 minutes; Ami-Pun (Daiichi Kogyo Seiyaku KK #! product) 0.2% Bath ratio 1:50 After immersing for 10 minutes, dehydrating and drying, place the next microfiber between the two layers of the copper ammonia rayon web. The web was sandwiched to form three layers and subjected to interlacing treatment according to the conditions described above, and after treatment and drying, an ultrafine fiber nonwoven fabric was obtained.

When we observed the cross section of this nonwoven fabric under a microscope, we found that
It was possible to observe the fiber entanglement described in detail above, such as the red-dyed cuprammonium rayon fibers entering the white polyester ultrafine fiber web layer and intertwining them.

Example 2 Among the webs made from the copper ammonia cellulose continuous filament (single yarn 1.5 d) used in Example 1, one with a basis weight of 10 Ji'/m'' was used.

Furthermore, the web made of ultrafine polyester fibers used in Example 1 had a basis weight of 20! //m2 was used.

Separately, a random card web of viscose rayon staple fiber (single thread 2d, fiber length 51cm) has a basis weight of 1
We prepared one with a length of 517 m.

For cholera web, a polyester ultrafine fiber web was laminated with a viscose rayon staple fiber web facing down, and a copper ammonia cellulose fiber continuous filament web was further laminated on top of the viscose rayon staple fiber web, and the ultrafine fiber nonwoven fabric was processed according to Example 1. was manufactured. The characteristic values are shown in Table 1.

As can be seen from the table, the water absorption and wet strength are on par with conventional products, but despite being thin with a basis weight of 4,597 m,
It can be seen that the wear resistance is also excellent, with a rate of 51.79G, which is five times higher than that of conventional products.

Example 3 Among the webs made of continuous filaments of copper ammonia cellulose fibers used in Example 1, one with a basis weight of 1017 m'' was used to form two layers, and between them a sufficiently scaled valve seat (
A nonwoven fabric having a fabric weight of 20.9 m'' was sandwiched between layers and treated according to Example 1 to obtain an ultrafine fiber nonwoven fabric. Its characteristic values are shown in Table 1.

As can be seen from the table, the water absorption and dust resistance are on par with conventional products, but the abrasion resistance is slightly better.

Margin Example 4 Below, in this example, the fineness of the ultrafine fibers was varied and the relationship with the dustproof rate was examined.

The copper ammonia cellulose fiber (copper ammonia rayon) continuous filament web used in Example 1 was prepared.

Separately, a web was manufactured by spinning ultrafine fibers of preester using a melt spinning method. At that time, the fineness of the fiber is 1
．． Webs of different deniers were manufactured by spinning the fibers with different deniers of Od, 0.6d, and 0.3d.

Then, the ultrafine fiber web was sandwiched and laminated into three layers, each having a different denier, and each layer was treated according to the treatment conditions of Example 1.

Table 2 shows the characteristic values of the ultrafine fiber nonwoven fabric for each denier. Further, the characteristic values in the case of using a web of ultrafine fibers of Q and 05d are those of Example 1.

As can be seen from Table 2, the fineness of the ultrafine fibers is 1. The dustproof rate of the Od product is 3.9%, which is much lower than the 10.1% dustproof rate of the conventional product described in Example 1, and is 7.8% at 0.6d.
It can be seen that it is possible to manufacture products close to conventional products. Furthermore, the fineness of the ultrafine fibers is as high as 10.6 at 0 and 3 d, and 13.8 at 0.05 d, indicating that the fineness of the ultrafine fibers is preferably 0.6 d or less.

Example 5 Copper ammonia cellulose fibers (copper ammonia rayon) were spun into 15 m x 20 m by a downward tension spinning method.
y Cut into four types of staple fibers of 28 m and 51 m, scouring, drying, and carding to produce a class 4a1 web (single yarn 1.6 d, basis weight 20 JJ/m"
).

Further, using the F-edge device for spinning ultrafine yarn disclosed in Japanese Patent Application Laid-Open No. 51-70311, single yarns of copper ammonia cellulose fibers with 0. A large number of ld yarns are spun to produce a fabric weight of 10117m.
” was produced.

Then, the ultrafine fiber webs were sandwiched between each of the four types of webs and laminated in three layers, and treated with a high-pressure thin jet of water according to Example 1. Table 2 shows the characteristic values of the obtained ultrafine fiber nonwoven fabric.

As can be seen from the table, the fiber length of 15+w+ has a low wet strength of 1.1 ky/5 cm width, and a dustproof rate of 3.
．． It can be seen that the peel strength is as low as 3 mm, and the peel strength is also as low as 1101/15 m width.If the fiber length is 20 mm or more, each property value can be formed close to that of the conventional product.

Margins below [Effects of the Invention] The ultrafine fiber nonwoven fabric of the present invention has water absorption and moisture absorption properties comparable to conventional products, high lint-free properties, i.e., abrasion resistance, and excellent bacterial barrier properties ( The composite nonwoven fabric has excellent functions and effects such as dust resistance), thereby making it possible to provide a composite nonwoven fabric suitable for use in the medical and electronics fields.

The microfiber nonwoven fabric of the present invention is useful as a packaging material in the medical field. Impurities are not extracted during steam sterilization, making it hygienic.

Furthermore, even after E, O, G sterilization, no E, O, G remains. Furthermore, since it has excellent water absorption and high lint-free properties, it is useful as a wine base in the electronics field.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically illustrating the state of the ultrafine fiber nonwoven fabric of the present invention before entanglement, and FIG. 2 is an enlarged cross-sectional view (magnification: approximately 60 times) of the ultrafine fiber nonwoven fabric of the present invention. ■ and ■... web layer consisting of cellulose long fibers,
■...Web layer made of ultrafine fibers, 111'l 1'
11#... cellulose long fiber, 2... ultrafine fiber.

Claims (1)

[Claims] 1. An ultrafine fiber nonwoven fabric with a three-layer structure consisting of two web layers made of long fibers or cellulosic fibers having a relatively long fiber length, and a web layer made of ultrafine fibers arranged between the two web layers. An ultrafine fiber nonwoven fabric characterized in that the fibers constituting each web layer of the nonwoven fabric are integrally intertwined with the fibers constituting other web layers.