JP7232111B2 - elastic laminate - Google Patents

Description

The present invention relates to elastic laminates.

In the medical field, there is a demand for fabrics (stretchable materials) with excellent extensibility in a wide range of products such as gauze, bandages and poultices. Since these products are to be worn by people, they should not be uncomfortable, and specifically require a certain degree of thinness, flexibility, and breathability.

In general, woven fabrics and non-woven fabrics of short fibers are used as elastic materials for medical use, but in recent years, many examples of using ultrafine long fibers have been reported.
For example, Patent Literature 1 below discloses a support for a poultice comprising a single layer of a meltblown nonwoven fabric, which is a long-fiber nonwoven fabric. It is disclosed that, by using the support, it has a chemical liquid retention property, a chemical liquid effect persistence, and an adhesive property.

Further, Patent Document 2 below discloses a stretchable composite fiber sheet obtained by combining a nonwoven fabric made of elastomer fibers and a nonwoven fabric or fabric made of non-elastomeric fibers. Non-elastomeric fiber non-woven fabrics are mainly formed by a needle punching method, and two non-woven fabrics are combined by thermal bonding.

JP-A-2001-79032 JP-A-63-145463

In view of the above prior art, the problem to be solved by the present invention is that it has sufficient tensile strength even if it is thin, and it is suitable for medical use, which has little oozing of chemicals and the like, and does not cause delamination. Another object of the present invention is to provide a stretchable laminate.

As a result of intensive research and repeated experiments to solve the above problems, the present inventors unexpectedly found that the elastic laminate having the specific structure described below can solve the above problems, and completed the present invention. It is a thing.

That is, the present invention is as follows.
[1] An elastic laminate in which a nonwoven fabric and an elastic substrate are joined by embossing, the elastic laminate having a thickness of 0.02 mm to 3.0 mm, and the elastic laminate The body is the following formula:
0.3 ≤ 1000 x airflow resistance (kPa s/m) / {embossing rate (%) x formation index} ≤ 2.3
An elastic laminate characterized by satisfying
[2] The elastic laminate according to [1], wherein the embossing rate is 5% to 65%.
[3] The stretchable laminate according to [1] or [2], wherein the stretchable laminate has a ventilation resistance of 0.1 kPa·s/m to 4.0 kPa·s/m.
[4] The elastic laminate according to any one of [1] to [3], wherein the elastic laminate has a formation index of 20 to 200.
[5] The elastic laminate according to any one of [1] to [4], wherein the elastic laminate has a tensile strength of 0.01 N/25 mm to 5.0 N/25 mm at 5% elongation.
[6] The elastic laminate according to any one of [1] to [5], wherein the elastic laminate has an elongation recovery rate of 60% to 100%.
[7] The elastic laminate according to any one of [1] to [6], wherein the nonwoven fabric has an average fiber diameter of 0.1 μm to 3 μm.
[8] The elastic laminate according to any one of [1] to [7], wherein the nonwoven fabric has a specific surface area of 0.1 ^m 2 /g to 4.5 m ² /g.
[9] The elastic laminate according to any one of [1] to [8], wherein the nonwoven fabric has a basis weight of 1.0 g/m ² to 40 g/m ² .
[10] The elastic laminate according to any one of [1] to [9], wherein the nonwoven fabric has a porosity of 40% to 95%.
[11] The elastic laminate according to any one of [1] to [10], which is for medical use.

INDUSTRIAL APPLICABILITY The stretchable laminate according to the present invention has sufficient tensile strength even when the thickness is thin, and it can be suitably used as a stretchable material for medical use because it causes little oozing of chemicals and does not cause delamination. be.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
The elastic laminate of the present embodiment is an elastic laminate in which a nonwoven fabric and an elastic substrate are joined by embossing, and the thickness of the elastic laminate is 0.02 mm to 3.0 mm. and the elastic laminate has the following formula:
0.3 ≤ 1000 x airflow resistance (kPa s/m) / {embossing rate (%) x formation index} ≤ 2.3
is characterized by satisfying

The elastic laminate of this embodiment is a laminate containing a nonwoven fabric and an elastic base material.
The type of nonwoven fabric that constitutes the elastic laminate of the present embodiment is not particularly limited, and nonwoven fabrics using ultrafine fibers produced by a dry method, a wet method, an electrospinning method, a meltblown method, or the like can be used. Nonwoven fabrics produced by the meltblown method are preferred because they can be easily and densely formed into ultrafine nonwoven fabrics.

As the stretchable base material constituting the stretchable laminate of the present embodiment, if it is a fabric having an elongation of 5% or more at a load of 4.0 N / 25 mm in either the vertical or horizontal direction, the type of fabric is not particularly limited. A woven fabric, a knitted fabric, a non-woven fabric, or the like can be used instead, but the knitted fabric is preferred.

In the elastic laminate of this embodiment, the nonwoven fabric and the elastic base material are joined by embossing. Bonding by embossing is preferable because the surface area and pore size of the nonwoven fabric and the stretchability of the stretchable substrate can be maintained, and multiple webs with different properties can be integrated without using a binder, especially for medical stretchable laminates. very preferred as The surface pattern of the uneven surface roll used for embossing is preferably one that does not destroy the properties of the nonwoven fabric and the stretchable substrate. Further, embossing is preferably performed at a temperature 100 to 200° C. lower than the melting point of the thermoplastic resin that constitutes the nonwoven fabric and/or the stretchable substrate.

The thickness of the elastic laminate of the present embodiment is 0.02 mm to 3.0 mm, more preferably 0.05 mm to 2 mm, still more preferably 0.1 mm to 1.5 mm. If the thickness is less than 0.02 mm, handleability will deteriorate. On the other hand, if the thickness exceeds 3.0 mm, discomfort during use will increase.

The elastic laminate of this embodiment has the following formula:
0.3 ≤ 1000 x airflow resistance (kPa s/m) / {embossing rate (%) x formation index} ≤ 2.3
is characterized by satisfying If 1000×airflow resistance (kPa·s/m)/{embossing ratio (%)×formation index} is less than 0.3, the agent will seep into the stretchable base material. If it exceeds 3, peeling (delamination) between the nonwoven fabric and the elastic substrate occurs. 1000×airflow resistance (kPa·s/m)/{embossing ratio (%)×formation index} is more preferably 0.6 or more and 2.0 or less.

The embossing rate in joining the stretchable laminate of the present embodiment by embossing is preferably 5% to 65%. If the embossing rate is 5% or more, the nonwoven fabric and the stretchable base material can be sufficiently integrated, and delamination is unlikely to occur. On the other hand, if the embossing rate is 65% or less, the properties of the nonwoven fabric and the stretchable substrate are not destroyed.

The average fiber diameter of the fibers constituting the nonwoven fabric constituting the elastic laminate of the present embodiment is preferably 0.1 μm to 3 μm, more preferably 0.2 μm to 2.5 μm, and still more preferably 0.3 μm. ~2 μm. When the average fiber diameter is 0.1 μm or more, the drug sufficiently permeates into the nonwoven fabric.

In the elastic laminate of the present embodiment, dispersibility is an important factor for drug retention, and the formation index, which indicates dispersibility, is preferably 20 to 200, more preferably 30 to 180, and still more preferably. 35-170. If the formation index is 200 or less, unevenness in basis weight is sufficiently small, and the drug is less likely to seep out into the stretchable base material at locations with low basis weight. On the other hand, if the formation index is 20 or more, the chemical will sufficiently permeate into the nonwoven fabric.

The tensile strength of the elastic laminate of the present embodiment at 5% elongation is preferably 0.01 N/25 mm to 5.0 N/25 mm, more preferably 0.02 N/25 mm to 4.0 N/25 mm, More preferably, it is 0.03N/25mm to 3.5N/25mm. If the tensile strength at 5% elongation is 5.0 N/25 mm or less, the fit is good and the tightening is appropriate.

The stretch recovery rate of the elastic laminate of the present embodiment is preferably 60% to 100%, more preferably 65% to 100%, still more preferably 70 to 100%, and particularly preferably 80 to 100%. be. If the elongation recovery rate is 60% or more, the structure will not be destroyed.

The elastic laminate air resistance of the present embodiment is preferably 0.1 kPa s/m to 4.0 kPa s/m, more preferably 0.2 kPa s/m to 3.5 kPa s/ m, more preferably 0.3 to 3.0 kPa·s/m. If the ventilation resistance is 0.1 kPa·s/m or more, the agent is less likely to seep into the stretchable base material. On the other hand, if the ventilation resistance is 4.0 kPa·s/m or less, the drug will sufficiently permeate into the nonwoven fabric.

The specific surface area of the nonwoven fabric constituting the elastic laminate of the present embodiment is preferably 0.1 m ² /g to 4.5 m ² /g, more preferably 0.3 m ² /g to 3.5 m ^{2 .} /g, more preferably 0.5 m ² /g to 3.0 m ² /g. If the specific surface area is 0.1 m ² /g or more, the drug is less likely to seep out into the stretchable base material. On the other hand, if it is 4.5 m ² /g or less, the drug will sufficiently permeate into the nonwoven fabric.

The fabric weight of the nonwoven fabric constituting the elastic laminate of the present embodiment is preferably 1.0 g/m ² to 40 g/m ² , more preferably 2 g/m ² to 30 g/m ² , still more preferably 3 g. /m ² to 25 g/m ² . If the basis weight is 1.0 g/m ² or more, the drug is less likely to seep into the stretchable base material. On the other hand, if the basis weight is 40 g/m ² or less, the drug will sufficiently permeate into the nonwoven fabric.

The porosity of the nonwoven fabric constituting the elastic laminate of the present embodiment is preferably 40% to 95%, more preferably 50% to 93%, still more preferably 55% to 90%. If the porosity is 40% or more, a high surface area can be maintained, while if it is 95% or less, the shape can be maintained as a nonwoven fabric.

In the elastic laminate of the present embodiment, both the nonwoven fabric and the elastic substrate are preferably made of a thermoplastic synthetic resin. For example, it can be polyolefin resin, polyester resin, polyphenylene sulfide resin, and specifically, ethylene, propylene, 1-butene, 1-hexane, 4-methyl-1-pentene, 1-octene, etc. High-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), high-density polyethylene, polypropylene (propylene homopolymer), polypropylene random copolymer, poly-1-butene, poly 4-methyl-1-pentene, ethylene-propylene random copolymer polyolefin, polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate). In particular, by using a nonwoven fabric composed of a resin having a melting point of 140° C. or higher, the spinning stability and processing characteristics when integrated are excellent. The material of the non-woven fabric and stretchable substrate is more preferably polyester or polypropylene polymer.

EXAMPLES The present embodiment will be specifically described below with reference to Examples, but the present embodiment is not limited to these Examples. In the following examples and comparative examples, unless otherwise specified, the physical properties of the nonwoven fabric and the stretchable substrate were measured using the stripped stretchable laminate.

(1) Thickness (μm)
Measurement is carried out using a PEACOCK thickness gauge with a load of 5 g/cm ² . A total of 10 points are measured equally in the vertical and horizontal directions, and the average value is taken as the thickness.

(2) Airflow resistance [kPa s/m]
The airflow resistance of the samples was measured.
Measuring device: KES-F8-AP1 air permeability tester manufactured by Kato Tech Measuring conditions: Piston speed: 2.0 cm/s
Integration method: Standard
Sensitivity: L (200Pa/V)
Vent area: 2π (cm ² )

(3) Formation index Apparatus type: FMT-MIII manufactured by Nomura Shoji Co., Ltd. was used.
With no sample set, the amount of transmitted light was measured with a CCD camera when the light source was on/off. Subsequently, the amount of transmitted light was similarly measured with the sample cut into A4 size set, and the average transmittance, average absorbance, and standard deviation (variation in absorbance) were obtained. The formation index can be determined by {standard deviation/average absorbance}×10. The formation index has an extremely high correlation with visual observation, and is the most direct index of the formation of the sample. Also, the formation index becomes smaller as the formation becomes better, and becomes larger as the formation becomes worse.

(4) Measurement of Average Fiber Diameter (μm) The average fiber diameter of the nonwoven fabric was measured as it was as a laminate. The laminate was cut into a size of 10 cm×10 cm and pressed against an iron plate at 60° C. for 90 seconds at a pressure of 0.30 MPa, and then platinum was deposited on the surface of the non-woven fabric. Using an SEM apparatus (JSM-6510, manufactured by JEOL Ltd.), the surface of the nonwoven fabric was photographed under the conditions of an acceleration voltage of 15 kV and a working distance of 21 mm. The photographing magnification was 10,000 times for yarns with an average fiber diameter of less than 0.5 µm, 6,000 times for yarns with an average fiber diameter of 0.5 to 1.5 µm, and 4,000 times for yarns with an average fiber diameter of 1.5 µm or more. The field of view at each magnification was 12.7 μm×9.3 μm at 10000×, 21.1 μm×15.9 μm at 6000×, and 31.7 μm×23.9 μm at 4000×. More than 100 fibers were photographed at random, and all fiber diameters were photographed. However, the fibers that are fused together in the yarn length direction are excluded from the objects of length measurement. The formula below:
Dw=ΣWi·Di=Σ(NiDi ² )/(Ni·Di)
{In the formula, Wi=weight fraction of fiber diameter Di=Ni.Di/.SIGMA.Ni.Di. where i is the number of fibers photographed, Di is the fiber diameter of the i-th fiber, and Ni is the number of fibers with fiber diameter Di. }
The weight average fiber diameter (Dw) determined by the above was taken as the average fiber diameter.

(5) Measurement of tensile strength (N / 25 mm) at 5% elongation According to the method specified in JIS 8113, a test piece of width 25 mm × length 200 mm was fixed so that the distance between the grips was 100 mm, and the cross Measurement is performed at a head speed of 20 mm/min. A load is applied until the test piece breaks, measurements are taken at a total of 5 points in each of the vertical and horizontal directions, and the tension at 5% elongation is confirmed from the results.

(6) Elongation recovery rate (%)
A sample having a width of 25 mm and a length of 200 mm is fixed so that the distance between the grips is 100 mm, and the distance between the grips is extended to 200 mm at a crosshead speed of 20 mm/min. From the result of releasing the grip from that state and measuring the length of the sample after that, the following formula:
Elongation recovery rate (%) = 100-{(A-B)/B x 100}
{In the formula, A: dimension before stretching, B: dimension after stretching. }
Calculate the recovery rate.

(7) Specific Surface Area Apparatus model: Gemini2360 (manufactured by Shimadzu Corporation) is used.
A sample is rounded into a cylindrical shape and packed in a cell for specific surface area measurement. The weight of the sample charged at this time is about 0.20 to 0.60 g. After drying the cell containing the sample at 60° C. for 30 minutes, it is cooled for 10 minutes. After that, the cell was set in the above specific surface area measuring device, and the following BET relational expression was obtained by nitrogen gas adsorption on the sample surface:
P/{(V(P0−P)}=1/(Vm×C)+{(C−1)/(Vm×C)}(P/P0)
{Wherein, P is the adsorption equilibrium pressure, V is the adsorption amount at the adsorption equilibrium pressure, P0 is the saturated water vapor pressure (Pa), and Vm is the monomolecular layer adsorption amount (mg/ g), and C is a parameter (-) < 0, such as for the heat of adsorption. This relational expression holds particularly well in the range of P/P0=0.05 to 0.35. } to obtain the specific surface area value. The BET relational expression is a formula that expresses the relationship between the adsorption equilibrium pressure P and the adsorption amount V at that pressure when the adsorption equilibrium state is established at a constant temperature.

(8) basis weight (g/m ² )
A sample is cut into a shape of 10 cm long×10 cm wide, and the mass per unit area is calculated.

(9) Porosity (%)
Calculate the porosity with the following formula:
Porosity (%) = [1-{basis weight/(thickness x material density)}] x 100
Calculated by

(10) Chemical coating evaluation (exudation of chemicals, etc.)
20 g of a common poultice prepared in a ratio of 6:1.5:1 of methyl salicylate, dl-camphor, and l-menthol was spread evenly on the non-woven surface of the elastic laminate cut to 10 cm × 14 cm. to coat. Whether or not the chemical oozes out on the surface of the laminate on the stretchable substrate side (the non-bonded surface of the stretchable substrate) when coated is determined according to the following evaluation criteria.
OK: No drug oozes out. NG: Drugs ooze out.

(11) Delamination After applying the poultice, the drug surface (nonwoven fabric surface) is adhered to a person, holding the elastic base material of the elastic laminate, and peeling it off with a force of 1 N / 10 cm. Whether or not the stretchable base material is peeled off is judged according to the following evaluation criteria.
OK: no peeling NG: peeling.

[Examples 1 to 3, Comparative Examples 4 to 8]
Polyethylene terephthalate (hereinafter referred to as PET) resin was used as a fibrous material by a meltblown method, and the PET resin melted by an extruder was extruded from a spinning nozzle having a spinning nozzle diameter of 0.30 mm. The melting temperature of the PET resin in the extruder, the spinning gas temperature, the single-hole discharge amount of the molten resin, etc. were appropriately selected, and the thermoplastic resin was pulled and thinned. After that, the elastic base material, which is a circular knitted fabric with a jersey structure, and the obtained nonwoven fabric were calendered.

[Examples 4 and 5, Comparative Example 9]
Polypropylene (hereinafter referred to as PP) resin was used as a fibrous material by the meltblown method, and the PP resin melted by an extruder was extruded through a spinneret having a spinneret diameter of 0.30 mm. The melting temperature of the PP resin in the extruder, the spinning gas temperature, the single-hole discharge amount of the molten resin, etc. were appropriately selected, and the thermoplastic resin was pulled and thinned. After that, the woven stretchable substrate and the obtained nonwoven fabric were calendered.

[Comparative Examples 1 and 2]
A PET resin was used as a fibrous material by a meltblown method, and the PET resin melted by an extruder was extruded through a spinning nozzle having a diameter of 0.30 mm. The melting temperature of the PET resin in the extruder, the spinning gas temperature, the single-hole discharge amount of the molten resin, etc. were appropriately selected, and the thermoplastic resin was pulled and thinned.

[Comparative Example 3]
The elastic substrate used in Example 1 was obtained without being laminated with the nonwoven fabric.
Various physical properties of the fabrics obtained in the above Examples and Comparative Examples are shown in Table 1 below.

The elastic laminate according to the present invention has sufficient tensile strength even if the thickness is thin, and the chemical oozes out little and does not cause delamination. It can be suitably used as a stretchable material in the medical field that requires high holding capacity for drugs and the like.

Claims (10)

An elastic laminate in which a nonwoven fabric and an elastic substrate are bonded by embossing, the elastic laminate having a thickness of 0.02 mm to 3.0 mm, and the elastic laminate having the following formula:
0.3 ≤ 1000 x airflow resistance (kPa s/m) / {embossing rate (%) x formation index} ≤ 2.3
and an elongation recovery rate of the elastic laminate of 60% to 100% . The elastic laminate according to claim 1, wherein the embossing rate is 5% to 65%. 3. The stretchable laminate according to claim 1, wherein the stretchable laminate has an air resistance of 0.1 kPa·s/m to 4.0 kPa·s/m. The elastic laminate according to any one of claims 1 to 3, wherein the elastic laminate has a formation index of 20 to 200. The elastic laminate according to any one of claims 1 to 4, wherein the elastic laminate has a tensile strength of 0.01 N/25 mm to 5.0 N/25 mm when stretched by 5%. The elastic laminate according to any one of claims 1 to 5 , wherein the nonwoven fabric has an average fiber diameter of 0.1 µm to 3 µm. The elastic laminate according to any one of claims 1 to 6 , wherein the nonwoven fabric has a specific surface area of 0.1 m ² /g to 4.5 m ² /g. The elastic laminate according to any one of claims 1 to 7 , wherein the nonwoven fabric has a basis weight of 1.0 g/m ² to 40 g/m ² . The elastic laminate according to any one of claims 1 to 8 , wherein the nonwoven fabric has a porosity of 40% to 95%. The elastic laminate according to any one of claims 1 to 9 , which is for medical use.