JPH04333652A - Nonwoven composite sheet for medical care - Google Patents

Abstract

PURPOSE:To provide a non-woven fabric composite sheet suitable for medical gowns having excellent wearing comfort, etc. CONSTITUTION:A non-woven fabric composite sheet for clothes, produced by laminating a sheet comprising rayon short fibers having a length of 5mm and a single diameter of 10mum and having a weight of 40g/m<2> to a polyester spun bonded fabric having a weight of 30g/m<2> and subsequently subjecting the laminated product to a column flow interlacement treatment alternately from either of both the sides of the fabric. The composite sheet has not only excellent softness, air permeability, bulkiness and wearing comfort but also good strength, water resistance and bacteriumbarriering property for practical uses, thereby permitting to realize defect-free medical gowns.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical nonwoven composite sheet. In detail, it is a non-woven medical gown with an unprecedented balance that has sufficient liquid repellency, bacterial barrier properties, and mechanical strength, while also being comfortable to wear, especially in terms of flexibility and texture. , relates to a medical nonwoven composite sheet that can be used for drapes, wipers, etc.

0002

[Prior Art] Compared to conventional linen medical gowns, non-woven medical gowns are more convenient for hospitals because they are disposable, and have a total cost advantage that leads to reduced labor costs in terms of hygiene and recycling storage management. Various types of gowns with improved bacterial barrier properties and comfort are now available on the market, and are increasingly being used in place of woven linen medical gowns. Conventional nonwoven medical gowns can be broadly divided into three types. One type uses a spunbond nonwoven fabric disclosed in Japanese Patent Publication No. 48-38025. This is a method in which the filaments are pulled by air, gas, etc. just below the spinning of a polymer, the assembled web is thermally embossed, and the fibers are thermally bonded at the embossed portions. Therefore, although it has sufficient strength and breathability to withstand wearing, it has the disadvantage of poor liquid repellency and bacterial barrier properties due to poor uniform dispersibility. The second type is a composite nonwoven fabric sheet made of a composite of a web and a nonwoven fabric, as disclosed in, for example, Japanese Patent Application Laid-Open No. 59-94659. This is a so-called spunlace type nonwoven fabric in which a paper sheet of wood pulp is laminated on a long fiber aggregate and integrated with columnar flow entanglement. Because it is fibrillated and packed, it has excellent water resistance, that is, bacterial barrier properties.However, on the other hand, since the entanglement caused by columnar flow is linear with respect to the nonwoven fabric, the strength in the winding direction is high, but it is not perpendicular to the winding direction. It has extremely low directional strength, and because it uses pulp, it is thin and has a paper-like feel, lacking a luxurious feel. Furthermore, as disclosed in Japanese Patent Application Laid-open No. 1-97257, a fiber fleece is produced by self-adhering each intersection of a fiber web formed by short fibers other than pulp in a sheet shape and a continuous filament group. There is a nonwoven fabric in which short fibers or short fibers and continuous filaments are tightly entangled by applying a high-pressure columnar flow to a stacked laminate. This is said to have excellent drapeability and strength, but since the short fiber web is produced using a card method or an air lay method, and short fibers with a relatively long fiber length are used, high-speed columnar flow is required. The strength is still insufficient because the fibers are not sufficiently intertwined during the process. Furthermore, JP-A-3-33
No. 52 discloses that a fibrous web A layer containing split fibers formed by joining ultrafine fibers and a fibrous web B layer consisting of constituent fibers with a larger fineness than the ultrafine fibers are laminated and subjected to high-pressure columnar flow. A nonwoven fabric with excellent bacteria barrier properties is disclosed in which split fibers are divided into ultrafine fibers and the ultrafine fibers and constituent fibers are entangled and integrated. However, since the web of this nonwoven fabric is manufactured using a card method, the fiber length is long, and since the split fibers are split after being made into a web, the opening and dispersion of the ultrafine fibers is insufficient, resulting in a lack of uniformity. It has the disadvantage of being exposed to water, and even though it uses ultra-fine fibers, its strength and water pressure resistance are insufficient. The third example is a wet-laid nonwoven fabric that has uniformity, extremely high density, and a soft texture, and is produced using a papermaking method, and has strength developed through columnar flow entanglement. For example, JP-A-3-14 filed by the present applicant.
No. 693 is mentioned, which states that the fiber length is 20 mm.
Even if it is as short as below, the ratio of fiber length (L) to fiber diameter (d) is 0.
．． It is stated that if it satisfies 8×103 <L/d<2.0×103, it has excellent uniformity and denseness, and the difference in strength between the winding direction and the direction perpendicular to it is extremely small, making it suitable for resin processing. A nonwoven fabric that is suitable for medical gowns is disclosed, which has sufficient strength to withstand practical use even without it, and is also excellent in lint-free properties. however,
This non-woven fabric had the disadvantage that the short fibers were highly entangled, so that the bulkiness associated with flexibility and luxury was slightly impaired.

[0003] As described above, nonwoven fabrics obtained by conventional techniques have advantages and disadvantages, and the current situation is that a nonwoven composite sheet for medical use that is free from defects has not yet been realized.

0004

[Problems to be Solved by the Invention] The present invention eliminates the drawbacks of conventional nonwoven fabric sheets, has sufficient strength, liquid repellency, bacteria barrier properties, and lint-free properties, and provides a sheet that is comfortable for the operator to wear. The object of the present invention is to provide a medical nonwoven fabric composite sheet that is particularly suitable for use as a nonwoven fabric for medical gowns and has excellent flexibility, bulkiness (luxury feel), and air permeability, and has no defects.

[0005]

[Means for Solving the Problems] The present invention provides a short fiber web layer made of regenerated cellulose and/or synthetic polymer, and a single fiber having a fineness of 0.5d or more, which is formed by partially bonding the constituent fibers to each other. A laminated nonwoven fabric composite sheet with a long fiber nonwoven fabric layer, wherein the fiber length of the short fiber web layer is 10 mm or less, and the ratio of fiber length (L) to single fiber diameter (d) is 0.05.
×103≦L/d≦0.6×103, and the short fibers are intertwined with each other in the web layer, and the fibers of both layers are intertwined at the joint surface of the short fiber web layer and the nonwoven fabric layer. This is a medical nonwoven composite sheet characterized by being interlaced and integrated.

That is, the present inventors laminated a short fiber web layer made of short fibers having a very limited length and thickness relationship and a long fiber nonwoven fabric layer, and created a high-speed columnar flow caused by water flow or the like, knee pants, etc. We have discovered that when interlaced and integrated using the method described above, a medical non-woven composite sheet can be obtained that exhibits extremely high flexibility and breathability, which contributes to the comfort of medical gowns, and has sufficient strength and water resistance for practical use, and has developed the present invention. This is what we have come to.

[0007] The short fiber web layer referred to in the present invention must be an aggregate of regenerated cellulose short fibers or synthetic polymer short fibers, and it is preferable to make it by the papermaking method in that it can be uniformly accumulated. is preferred, but of course if possible,
Other methods may also be used. The regenerated cellulose short fibers mentioned here are made from pulp and cotton.
Examples include viscose rayon and cupro, and synthetic polymer short fibers include polyethylene, polypropylene,
Examples include short fibers such as polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, and acrylic. The length of the short fibers used is 10 mm or less, and the ratio L/d of short fiber length L to single fiber diameter d is 0.05.
It is necessary to satisfy ×103≦L/d≦0.6×103.

[0008] The single fiber diameter d here corresponds to the arithmetic average of the longest length and the shortest length passing through the center of gravity of the cross section when the cross section of the fiber is not circular, and when the cross section is circular,
Of course, it corresponds to the diameter of a circle. If the short fibers meet the above conditions, when the short fibers are laminated on the nonwoven fabric layer and then subjected to the interlacing treatment using columnar flow or needle punching, the short fibers will become intertwined mainly by forming loops between the short fibers within the web layer. The intertwining with the long fibers of the nonwoven fabric layer is performed in a well-balanced manner, resulting in a nonwoven fabric composite sheet with excellent flexibility and air permeability without compromising strength or water pressure resistance, which was completely unexpected at the time. That is, in a composite sheet of a short fiber web layer and a long fiber layer, the short fibers in the short fiber web layer form loops between intertwining points, creating a "three-dimensional structure" centered on a relaxed intertwined state. As a result, it has extremely flexible properties, a bulky texture and breathability, and has a structure in which the long fibers of the long fiber nonwoven fabric layer are sufficiently intertwined. ”, so it develops sufficient strength. Furthermore, because of this "structure in which the interlacing is sufficiently dense,"
Practical water pressure resistance is achieved by water repellent treatment using a water repellent agent. As the water repellent, commercially available water repellents such as fluorine-based, silicone-based, and wax-based water repellents can be used, and the adhesion amount thereof is usually preferably about 0.1 to 5% based on the weight of the nonwoven fabric. In addition, in a "structure in which the entanglement is sufficiently dense", the average of the straight lines connecting the interlacing points of adjacent fibers is 40
A thickness of 0 μm or less and 0.1 μm or more is preferable in terms of strength and water pressure resistance.

[0009] Regarding the entanglement of short fibers in the short fiber web layer, the average length L'' of the fibers connecting adjacent interlace points among the interlace points formed by any short fiber with other short fibers is and the average length L' of the straight line distance connecting the adjacent intersection points.
When the ratio L''/L' is 1.5 or more, the rate of forming loops is high and is preferable.When the fiber length of the short fibers is too long or thick, such as when the fiber length L exceeds 10 mm, Because it is difficult for fibers to move in the web, sufficient orientation of the fibers does not occur due to columnar flow or knee panning.Furthermore, even if the fibers are short, if they are not balanced with the fiber thickness, for example, L/d>0 In the case of .6, the entanglement of the fibers in the web layer becomes strong and the entanglement with the short fibers in the long fiber nonwoven fabric layer is not sufficiently performed, and in the case of L/d<0.05, the short fibers are bent. It is presumed that this makes it difficult for the short fibers to intertwine and develop sufficient strength.In other words, only short fibers that meet the extremely limited conditions found by the present inventors have the above-mentioned structure and excellent properties. This aims to realize a medical nonwoven fabric composite sheet having the following characteristics.

[0010] The basis weight of the short fiber web layer is 1
A range of 0 g/m 2 to 100 g/m 2 is preferable because it causes sufficient intertwining mainly in the formation of loops between the short fibers and the intertwining and integration of the long fiber nonwoven fabric layer. In addition, in order to develop water pressure resistance and strength, pulp, ultrafine fibers, etc. may be mixed to the extent that flexibility and air permeability are not degraded.

[0011] Next, the long fiber nonwoven fabric layer as used in the present invention is as follows:
Thermoplastic polymer fibers such as nylon 6, nylon 66, polypropylene, polyethylene terephthalate, and polybutylene terephthalate, their mixed spun fibers, and composite spun fibers are spun into a net and subjected to traction and heat embossing, the so-called spunbonding method and heat embossing. Mixing fused short fibers,
It is a nonwoven fabric obtained by partially joining with adhesive. The partially joined area is related to the intertwining of the short fiber web layer with the fibers, and in order to obtain sufficient strength and texture,
There is a suitable range depending on the joining method. for example,
In the spunbond method, which performs partial bonding by heat embossing,
It is preferable that thermal bonding be performed within a range of 2% to 20% of the area of the nonwoven fabric layer.

[0012] Furthermore, the thickness of the fibers used in the long fiber nonwoven fabric layer must have a single fiber fineness of 0.5 d or more, since this affects the strength of the nonwoven composite sheet. Further, the basis weight is preferably 10 g/m2 or more and 100 g/m2 or less. Next, as a compositing means for realizing interlacing centering around the loops of short fibers in the short fiber web layer and intertwining and integrating the long fibers in the long fiber nonwoven fabric layer and the short fibers in the short fiber web, This can be carried out by the conventionally known needle punching method or the columnar flow method described in JP-A-3-33252, but other known techniques can be used as long as they can achieve the purpose of the present application. Needless to say. Of these, compounding using the columnar flow method is
It is preferable to rotate the injection nozzle at high speed or insert a mesh between the injection nozzle and the laminate to be composited, since a medical nonwoven fabric composite sheet with no holes and extremely high surface quality can be obtained. In addition, in order to promote the development of strength by interlacing and integrating the two layers of the medical nonwoven composite sheet and the softening of the long fiber nonwoven fabric layer, it is necessary to It is best to apply needle punching or columnar flow. Note that it is preferable that the area of the portion treated by needle punching or columnar flow be 50% or more of the medical nonwoven fabric composite sheet because the desired structure and physical properties can be sufficiently expressed. Further, the thickness of the needle used for needle punching is preferably as thin as possible, for example, preferably 0.5 mm or less at the thickest point. In addition, the nozzle diameter of the columnar flow is 0.03
~0.5 mm is preferable, and the water pressure of the columnar flow is as follows:
20Kg/cm2 or more and 100Kg/cm2 or less,
preferable.

Next, the present invention will be explained in more detail using a structural cross-sectional conceptual diagram of an example of the present invention and measured values of its physical properties. FIG. 1 is a conceptual diagram of a cross-sectional structure in a direction perpendicular to the plane of a medical nonwoven fabric composite sheet according to Example 2, which is an example of the product of the present invention. In the figure, layer 1A is a short fiber web layer (40
g/m2), and layer 1B shows ester spunbond (hot embossed area 10%) with a single fiber diameter of 10 μm and a basis weight of 30 g/m2. As is clear from the figure, in layer 1A, the short rayon fibers 11 are arranged between adjacent interlacing points a and b.
This forms a loop (for example, the shaded part 11'). In addition, at the joint surface of layer 1A and layer 1B, rayon staple fibers 11
and ester long fibers 12 are sufficiently intertwined and integrated.

On the other hand, FIG. 2 shows, as a comparative example, a fiber length of 2.
A composite composite was prepared using the same long fiber nonwoven fabric as in Example 2 above under the same composite conditions, except that a short fiber web layer (fabric weight 40 g/m2) consisting of 0 mm short rayon fibers (fiber diameter 10 μm) was used. FIG. 2 is a conceptual diagram of a cross-sectional structure of a nonwoven fabric sheet in a direction perpendicular to a plane. In the figure, layer 2A is a short fiber web layer, and layer 2B is a long fiber nonwoven fabric layer. As is clear from the figure, since the rayon staple fibers 21 with a long fiber length of 20 mm are used in layer 2A, the short fibers are not sufficiently intertwined with each other, and almost no loops are formed, resulting in a flat surface. In contrast, short fibers are oriented horizontally. Therefore, 2A
At the bonding surface between the layer and the layer 2B, almost no entanglement is observed between the short rayon fibers 21 and the long ester fibers 22. Table 1,
By comparing Example 2 and Comparative Example 2 shown in Table 1, the effects of the present invention can be clearly seen. That is, the pure flexural modulus indicating the flexibility of Example 2, which is the product of the present invention, is:
It can be seen that the value is about half that of Comparative Example 2, indicating extremely excellent flexibility. Furthermore, it can be seen that it has excellent bulkiness and air permeability, as well as slightly superior strength. As described above, when the product of the present invention is used as a medical nonwoven fabric, especially a medical gown, it has excellent flexibility, is bulky and luxurious, is breathable, and is extremely comfortable to wear without stuffiness. It can be used as a well-balanced medical gown that satisfies practical strength, practical water pressure resistance, and bacteria barrier properties.

[0015]

[Examples] The present invention will be explained in more detail with reference to Examples below. Incidentally, the measured values in the examples were determined by the following method.・Weight (g/m2): Based on JIS-L-1096. - Thickness (mm): Compliant with JIS-L-1096.・Pure bending value (gcm2/cm): Using a pure bending tester (manufactured by Kato Tech Co., Ltd., pure bending tester), measure the composite process progress direction (longitude) of the sample and the direction perpendicular to it (latitude). Each value is measured five times and represents the average value.・Breathability (cc/cm2 ・sec); JIS-L-1
Measured using a Frazier type tester in accordance with 096. Expressed as the average value of 5 measurements. - Strong (Kg/3cm width); Compliant with JIS-L-1096. Adjust the sample so that it is 3cm wide and the grip interval is 20cm. Tensilon manufactured by Toyo Baldwin
Measured with UTM-I model. Expressed as the average value of 5 times.・Elongation (%): Measured using the same method as for strength. Expressed as the average value of 5 times.・Water pressure resistance (mmH2 0): Compliant with JIS-L-1092. Measured by low water pressure method (up to 1000 mmH2O water column) and expressed as the average value of 5 measurements.・Mason jar test: Based on IST80, 7-70, Mason jar method, measure the time (minutes) until water leakage occurs by applying a water column pressure of 114 mmH2O. A test of 60 minutes or more is considered to be a pass, and is expressed as the average value of three measurements.

The medical nonwoven fabric composite sheets of this example were all water-repellent treated after composite treatment, and the formulation was as follows. Water repellent; Meisei Chemical, Asahi Guard series, AG-43
3 Treatment: After immersing in a 3% aqueous solution of water repellent, drying at 100°C for 15 minutes, and further curing at 130°C for 1 minute.

[0017] Furthermore, all of the composition of the medical nonwoven fabric composite sheet of this example was carried out using a high-speed columnar flow of water. The combined conditions are as follows.・Column flow injection nozzle; orifice diameter 0.2 mm, pitch of widthwise arrangement 5.0 mm, ・Column flow number and conditions: 3 rows of column flow injection nozzles x 20 kg
/cm2 on the front and back, then 18 rows x 30Kg/cm2 on the front and back, and then between the nozzle and the medical nonwoven composite sheet.
Insert 0 mesh wire mesh and sprinkle water, 8 rows x 30kg/
cm2, and was sprayed and composited from the front and back.・Distance from nozzle to medical nonwoven sheet: 30mm
.・Mesh of conveyor wire mesh and conveyance speed: 80 mesh,
4m/min.・Nozzle rotation conditions: rotation radius 4mm, rotation speed 400rp
m.・Others: A long fiber nonwoven fabric layer is placed on a conveyor wire mesh, a short fiber web layer is placed on top of it, a columnar flow is first applied from the short fiber web layer side (front side), and then the long fiber nonwoven fabric layer is turned over. It was hung from the side (back side). (Preparation of short fiber web layer) Fiber length: 3 mm, single fiber diameter: 10
Micron short rayon fibers (L/d=0.3×10 3 ) were dispersed in water and stirred to form a slurry with a concentration of 1%. This slurry was made into paper using an inclined mesh paper making machine conveyed through an 80 mesh wire mesh to obtain a short fiber web layer (1) having a basis weight of 40 g/m2. Similarly, the fiber length is 5 mm, the single fiber diameter is 1
0 μm rayon staple fiber (L/d=0.5×103)
By changing the slurry concentration using
Short fiber web layer (2) of 0, 30, 40 g/m2, (
3)'' and (4) were obtained using short rayon fibers (L/d=0.6×103) with a fiber length of 6 mm and a single fiber diameter of 10 μm to obtain a short fiber web layer (5) with a basis weight of 40 g/m2. In addition, a short fiber web layer (6) consisting of short rayon fibers (L/d = 0.1 x 103) with a fiber length of 2 mm and a single fiber diameter of 20 μm was prepared using a short fiber web layer (6) with a single fiber diameter of 10 μm and a fiber length of 5 mm and 6 m.
m polyester fiber (L/d=0.5×103, 0
．． Short fiber web layers (7) and (8) with a basis weight of 40 g/m2 were obtained. Furthermore, one short rayon fiber and one short ester fiber with a fiber length of 5 mm and a single fiber diameter of 10 μm were used.
: 1 to form a short fiber web layer with a basis weight of 40 g/m2 (
9) was obtained.

[0018]

[Examples 1 to 12] As the long fiber nonwoven fabric layer, polyester spunbond E1030 (fabric weight 3
Short fiber web layers (1), (2), (3), (4), (5), (
6), (7), (8), and (9) were combined with columnar flow, respectively.

Example 1 and (4) are composites of (1) and (4).
Example 2 is a composite with (5), Example 3 is a composite with (6), Example 7 is a composite with (3), Example 8 is a composite with (2). Example 9 is the combination with (7), Example 10 is the combination with (8), Example 11 is the combination with (8), and Example 12 is the combination with (9).

In addition, as the long fiber nonwoven fabric layer, polyester spunbond E3030, polypropylene spunbond P3030, and nylon spunbond N30 manufactured by Asahi Kasei Corporation and having a basis weight of 30 g/m2 and a heat embossed area of 6% were used.
Examples 4, 5, and 6, which are products of the present invention, were obtained by subjecting the short fiber web layer (4) to the short fiber web layer (4) in a columnar flow manner.

[0021]

[Comparative Examples 1 to 8] As comparative examples, the fiber length is 1 mm and the single fiber diameter is 30 μm, and the single fiber diameter is 10 μm and the fiber length is 20 mm.
, each rayon staple fiber of 10 mm (each L/d=0.03×
103, 2.0×103, 1.0×103) with a basis weight of 40 g/m2, (10), (
11) and (12) were created in the same manner as short fiber web layer (1). Next, Comparative Examples 1, 2, and 3 were produced by using E1030 as a long fiber nonwoven fabric layer and compositing under the same columnar flow conditions as the present invention. In addition, the single fiber diameter is 10 μm, and the single fiber diameter is the same as that of polyester staple fibers with a fiber length of 10 mm.
Rayon short fibers with a fiber length of 8 mm were dispersed and mixed in water at a ratio of 1:1 to prepare a slurry solution with a concentration of 2%, and a short fiber web layer with a basis weight of 70 g/m2 was made using the paper making machine used in the example. I got it. Comparative Example 8 was obtained by applying a columnar flow to this short fiber web layer alone under the same conditions as in the example.

Tables 1 to 4 show Example 1, which is a product of the present invention.
~12, together with Comparative Examples 1, 2, 3, and 8 as a comparative example, E
1030, E3030, N3030, and P3030 were also used as Comparative Examples 4, 5, 6, and 7, and the physical property data necessary for medical gowns were measured and summarized. As can be seen from Tables 1 to 4, all of the products of the present invention have smaller pure curve values in both warp and latitude than Comparative Examples 1 to 3, which are composites, and Comparative Example 8, which has a basis weight of 70 g/m2. It can be seen that it has a large thickness, bulkiness, and excellent breathability, as well as good composite properties. Furthermore, compared to Comparative Example 8, the strength is excellent, and it can be seen that the decrease in strength due to water repellent treatment is improved by compounding.

Furthermore, compared to Comparative Examples 4, 5, 6, and 7, the strength, water pressure resistance, and mason jar quality were significantly superior, indicating that a composite effect was obtained. Regarding the ratio L''/L' of the average length L'' of the fibers connecting adjacent interlacing points in the short fiber web layer and the average length L' of the straight line distance connecting the adjacent interlacing points, Examples 1 to 12, which are the products of the present invention, all had L″/L′>2, but the comparative example 1
, 2, 3, and 8 all had L″/L′<1.5.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Effects of the Invention] The medical nonwoven composite sheet of the present invention is not only extremely flexible, bulky, and breathable, but also
It has sufficient strength, water resistance, and bacteria barrier properties to withstand practical use, so it can be used for medical gowns, drapes,
It can be used as a highly safe and comfortable item for various examination gowns and patient wear. In addition, it is expected to be used in various sanitary materials such as clean room workwear, masks, clean wipers, and filters.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a cross-sectional structure in a direction perpendicular to the surface of an embodiment of a medical nonwoven composite sheet of the present invention.

FIG. 2 is a conceptual diagram of a cross-sectional structure in a direction perpendicular to the plane of an example of a comparative example.

[Explanation of symbols]

1A, 2A Short fiber web layer 1B, 2B Long fiber nonwoven fabric layer 11, 21 Rayon staple fiber 12, 22 Ester long fiber

Claims (1)

[Claims] Claim 1: Lamination of a short fiber web layer made of regenerated cellulose yarn and/or a synthetic polymer system, and a long fiber nonwoven fabric layer with a single fiber fineness of 0.5 d or more, which is formed by partially bonding the constituent fibers together. A nonwoven fabric composite sheet, wherein the short fiber web layer has a fiber length of 10 mm or less, and a ratio of fiber length (L) to single fiber diameter (d) of 0.05 x 103 ≦L/d≦
0.6 x 103, and the short fibers are intertwined with each other in the web layer, and the fibers of both layers are intertwined and integrated at the bonding surface between the short fiber web layer and the nonwoven fabric layer. A medical nonwoven composite sheet featuring: