Antiviral fiber assembly with cellulose sulfate

Abstract

An object of the present invention is to provide an antiviral fiber assembly in which an antiviral agent is retained with chemical stability over a long period of time, and which is gentle to the human body. A further object of the present invention is to provide a fiber assembly with cellulose sulfate that can exhibit sufficient antiviral activity over a long period of time. Further, another object of the present invention is to provide a textile product obtained using such a fiber assembly. The present invention provides a fiber assembly with cellulose sulfate, wherein the hyaluronidase inhibitory activity is 50% or higher; and a process for producing a fiber assembly with cellulose sulfate, including treating a fiber assembly with an aqueous cellulose sulfate solution and drying, then treating the same with a pH buffer solution and drying.

Claims

1. A fiber assembly comprising hydrophobic fibers hydrophilized with an anionic surfactant comprising a phosphate ester salt, wherein the fiber assembly further retains cellulose sulfate and comprises pH buffer attached to the fiber assembly after the cellulose sulfate is retained thereon, the pH buffer is citrate buffer and is attached to the fiber assembly in an amount range from 0.1 to 0.2 wt % as an amount of attached components of the pH buffer relative to a total weight of the fiber assembly, the surfactant is attached to the fiber assembly in a range from 0.2 to 2.0 wt % relative to the total weight of the fiber assembly, the phosphate ester salt is a mixture of octyl phosphate salt or dodecyl phosphate salt with dipotassium tridecan-1-yl phosphate, hydrophobic fibers are, or a fiber assembly containing hydrophobic fibers is, hydrophilized with the surfactant by an immersion method, a coating method, or a spray method, so as to form the hydrophilized fibers, and the fiber assembly has a hyaluronidase inhibitory activity of 70% or higher.

2. The fiber assembly according to claim 1, wherein the fiber assembly containing the hydrophobic fibers is hydrophilized by the immersion method.

3. The fiber assembly according to claim 1, wherein the hydrophobic fibers are, or the fiber assembly is, hydrophilized in an aqueous solution of the surfactant by the immersion method.

4. The fiber assembly according to claim 1, wherein the cellulose sulfate has a degree of sulfur esterification of the cellulose sulfate in a range of 13 to 17% by weight as a sulfur concentration relative to a total amount of the cellulose sulfate.

5. The fiber assembly according to claim 1, wherein fibers constituting the fiber assembly comprise polyolefin, polyester, or a combination thereof.

6. A textile product obtained using the fiber assembly according to-claim 1.

7. A process for producing a fiber assembly comprising hydrophobic fibers hydrophilized with an anionic surfactant that comprises a phosphate ester salt, and having a hyaluronidate inhibitory activity, the process comprising: treating a fiber assembly with an aqueous cellulose sulfate solution and drying; and then treating the fibers with a pH buffer and drying, wherein hydrophobic fibers are, or a fiber assembly containing hydrophobic fibers is, hydrophilized with the surfactant by an immersion method, a coating method, or a spray method, so as to form the hydrophilized fibers, the surfactant is attached to the fiber assembly in a range from 0.2 to 2.0 wt % relative to the total weight of the fiber assembly, the phosphate ester salt is a mixture of octyl phosphate salt or dodecyl phosphate salt with dipotassium tridecan-1-yl phosphate, the fiber assembly further retains cellulose sulfate and comprises pH buffer attached to the fiber assembly after the cellulose sulfate is retained thereon, the pH buffer is citrate buffer and is attached to the fiber assembly in an amount range from 0.1 to 0.2 wt % as an amount of attached components of the pH buffer relative to a total weight of the fiber assembly, and the fiber assembly has a hyaluronidase inhibitory activity of 70% or higher.

8. The process for producing a fiber assembly according to claim 7, wherein the fiber assembly comprises the hydrophilized hydrophobic fibers and is formed by treating the fiber assembly with the surfactant before treating the fiber assembly with the aqueous cellulose sulfate solution.

Description

EXAMPLES

(1) The present invention is described in detail below through examples, but is by no means limited thereto. The evaluations in the examples were performed by the methods shown below.

(2) (Hyaluronidase Inhibitory Activity Test)

(3) First 50.2 mg of the test fiber or fiber assembly was placed in a screw-top test tube. Then 100 L of deionized water and 225 L of a mixture of hyaluronidase-0.1 M acetate buffer solution adjusted to 2.83 mg/mL and 0.1 M acetate buffer solution-0.3 M NaCl was added. The tube was shaken to mix the contents, and then let stand at 37 C. for 20 min. The volume ratio of the hyaluronidase-0.1 M acetate buffer solution to the 0.1 M acetate buffer solution-0.3 M NaCl was 1:8. Next 200 L of hyaluronic acid-0.1 M acetate buffer solution was added, and the tube was shaken to mix the contents and let stand at 37 C. for 20 min. Next 100 L each of aqueous 0.4 N NaOH solution and 0.8 M sodium borate solution was added, the tube was shaken to mix the contents, the cap was closed, and the tube was let stand at 100 C. for 3 min. After the tube was cooled about 30 sec, 3 mL of p-dimethylamino benzaldehyde was added, the tube was shaken to mix the contents, and then let stand at 37 C. for 20 min. Finally, the test fiber or fiber assembly was removed, and the absorbance was measured at 585 nm.

(4) The hyaluronidase inhibition activity was calculated by the following formula.
Hyaluronidase inhibition activity (%)={()()/()}100

(5) : Absorption measured after performing the above procedure without adding the fiber or fiber assembly test sample and by adding 225 L of deionized water and hyaluronic acid-0.1 M acetate buffer solution in place of the mixed solution of hyaluronidase-0.1 M acetate buffer solution and 0.1 M acetate buffer solution-0.3 M NaCl.

(6) : Absorption measured after performing the above procedure using the fiber or fiber assembly test sample.

(7) : Absorption measured after performing the above procedure without adding the fiber or fiber assembly test sample.

(8) The above test was performed again on the fiber assembly as a storage test after letting the fiber assembly stand in an environment at 50 C. and 65% RH for 1 month.

(9) [Nonwoven Fabric Made with the Fiber]Preparation of Fiber Assembly for Retaining Cellulose Sulfate

(10) Two types of nonwoven fabrics were produced by the following processes and conditions.

(11) (1) Through-air process (TA): Short fibers cut to 51 mm long and prepared using high-density polyethylene and polypropylene were used as the test fibers. The test fibers used are a conjugate fiber and the form is a concentric sheath-core type with a circular cross section. The test fibers were made into a carded web using a roller-carder test machine, and the carded web was processed into a nonwoven fiber with a mass per unit area of 22 g/m.sup.2 and a specific volume of about 54 cm.sup.3/g with a suction dryer. The processing temperature was 130 C.
(2) Spunbond process (SB): Spunbond processed EB3020 from Chisso Polypro Fiber Co., Ltd. were used. EB3020 is a nonwoven fabric of high-density polyethylene and polypropylene with a mass per unit area of 20 g/m.sup.2 and a specific volume of 11 cm.sup.3/g.
[Treatment Agents]

(12) The compositions of various treatment agents (units: wt %) used in treatment examples 1 to 5 are shown in Table 1 below divided into surfactant-containing textile oils used for the hydrophilization treatment (A) and pH buffer solutions (B). As described below, the surfactant-containing textile oils (A) and the pH buffer solutions (B) were used separately, and Table 1 lists the total of the surfactant-containing textile oil and the pH buffer as 100 wt %.

(13) Treatment examples 1 and 2 are cases wherein a surfactant-containing textile oil (A) and a pH buffer (B) were both used, and these show the percentage by weight of each component in relation to the total weight of (A) and (B) combined. Treatment examples 3 to 5 are cases wherein only a surfactant-containing textile oil (A) was used. In the following section entitled Treatment of nonwoven fabric, a method is described wherein both (A) and (B) were separately attached in sequence as the method of treating the nonwoven fabric (treatment examples 1 and 2). Treatment examples 3-5 are cases wherein only (A) was used, and these show the percentage by weight of each component in relation to (A).

(14) TABLE-US-00001 TABLE 1 Treatment Treatment example agent Component 1 2 3 4 5 (A) anionic sorbitan monopalminate 8 8 10 surfactant- sorbitan esters of tallow 26.4 26.4 33 containing fatty acid oil (a) potassium dodecyl 24.8 24.8 31 phosphate mixed potassium 20.8 20.8 26 phosphates* anionic potassium octyl phosphate 66 surfactant- potassium dodecyl 8 containing phosphate oil (b) propylene glycol 18 ethylene glycol 8 monobutyl ether cationic polyglycerol fatty acid ester 28 surfactant- polyether 28 containing polyether esters 20 oil alkyl imidazolium alkyl 10 sulfate polyoxyalkylene-modified 9 silicone ethylene oxide adduct 5 of alkanol amide (B) phosphate buffer** 20 citrate buffer*** 20 *The mixed potassium phosphates is dipotassium tridecan-1-yl phosphate **Phosphate buffer: pH 6.4 (value listed on reagent bottle), mixed reagent of potassium dihydrogen phosphate: 10 g/L and dipotassium hydrogen phosphate: 3.67 g/L. Shown as wt % of solid components. ***Citrate buffer: mixture of citric acid monohydrate and trisodium citrate dihydrate with weight ratio of 1:10 dissolved in deionized water and adjusted to a pH of 6.2. Shown as wt % of solid components.
[Treatment of Nonwoven Fabric]

(15) A hydrophilization treatment and treatment with cellulose sulfate (treatment examples 1 to 5) were performed in the following sequence on nonwoven fabrics prepared as described above, and then a treatment with a pH buffer was performed (treatment examples 1 and 2). In treatment example 6 only a treatment with cellulose sulfate was performed on the nonwoven fabric.

(16) First 3 g of the textile oil (A) of Table 1 diluted to have a solid component of 0.4 wt % was weighed out into a beaker so that the solid component would be 0.4 wt % in relation to the 3 g of nonwoven fabric that had been weighed out, and then deionized water was added and the volume was increased to make it sufficient to immerse the nonwoven fabric. Then the nonwoven fabric, which had been kept in a separate container, was immersed to attach the oil thereto. Rubber gloves were worn, and the nonwoven fabric was massaged with the hands to attach the oil uniformly to the nonwoven fabric. To attach surfactant that had become adhered to the walls of the beaker to the nonwoven fabric, a small amount of deionized water was swirled around the inside walls of the beaker and then attached to the nonwoven fabric in the manner described above. By repeating this procedure about two times, it was possible to attach essentially the entire amount of surfactant to the nonwoven fabric. The nonwoven fabric with the surfactant attached was placed on a Teflon film, and dried for 40 min in a 90 C. constant temperature bath. The nonwoven fabric was turned over once after 20 min had elapsed.

(17) Next, 3 g of cellulose sulfate diluted to have a solid component of 0.01 wt % was weighed out into a beaker so that the solid component would be 0.01 wt % in relation to the weight of the nonwoven fabric, and then the entire amount was attached and dried by the same method used for the textile oil described above. The cellulose sulfate was from Chisso Corporation (Lot No. A07070101). The cellulose sulfate was a colorless powder with a sulfur content of 14 wt % and a weight-average molecular weight of 66,000 (GPC measured value). The GPC measurement was performed as follows: GPC apparatus: Waters 2695, RI detector: Waters 2487, column: Shodex OHpak SB-G+OHpak SB-805 HQ+OHpak SB-802.5 HQ.

(18) Finally, 3 g of pH buffer solution (B) diluted in deionized water to have a solid component of 0.1 wt % was weighed out into a beaker so that the solid component (as solid component of pH buffer solution) would be 0.1 wt % in relation to the weight of the nonwoven fabric, and then the entire amount was attached and dried by the same method used for the textile oil and cellulose sulfate described above.

(19) Treatment examples 1 to 6 and the test results are described below.

(20) [Treatment Example 1]

(21) A spunbond nonwoven fabric was treated with a textile oil containing potassium dodecyl phosphate and mixed potassium phosphates as anionic surfactants, and sorbitan monopalminate and sorbitan esters of tallow fatty acid as nonionic surfactants, and after the cellulose sulfate was attached, the fabric was treated with a phosphate buffer solution.

(22) The results of the hyaluronidase inhibitory activity test revealed that both before and after storage the inhibitory activity was 50% or higher. A fiber assembly that achieves the object of the present invention was obtained thereby.

(23) [Treatment Example 2]

(24) A spunbond nonwoven fabric was treated with a textile oil containing potassium lauryl phosphate and mixed potassium phosphates as anionic surfactants, and sorbitan monopalminate and sorbitan esters of tallow fatty acid as nonionic surfactants, and after the cellulose sulfate was attached, the fabric was treated with a citrate buffer solution.

(25) The results of the hyaluronidase inhibitory activity test revealed that both before and after storage the inhibitory activity was 50% or higher. A fiber assembly that achieves the object of the present invention was obtained thereby.

(26) [Treatment Example 3]

(27) A through-air nonwoven fabric was treated with a textile oil containing potassium lauryl phosphate and mixed potassium phosphates as anionic surfactants, and sorbitan monopalminate and sorbitan esters of tallow fatty acid as nonionic surfactants, and thereafter the cellulose sulfate was attached.

(28) The results of the hyaluronidase inhibitory activity test revealed that before storage the inhibitory activity was 50% or higher, but after storage it had dropped to less than 50%.

(29) [Treatment Agent 4]

(30) A through-air nonwoven fabric was treated with a textile oil containing potassium octyl phosphate and potassium dodecyl phosphate as anionic surfactants, and ethylene glycol monobutyl ether as a nonionic surfactant, and thereafter the cellulose sulfate was attached.

(31) The results of the hyaluronidase inhibitory activity test revealed that before storage the inhibitory activity was 50% or higher, but after storage it had dropped to less than 50%.

(32) [Treatment Agent 5]

(33) A through-air nonwoven fabric was treated with a textile oil containing alkyl imidazolium alkyl sulfate as a cationic surfactant and polyglycerol fatty acid esters, poly ethers, polyether esters, and ethylene oxide adduct of alkanol amide as nonionic surfactants, and thereafter the cellulose sulfate was attached.

(34) The results of the hyaluronidase inhibitory activity test revealed that even before the storage test the inhibitory activity was less than 50%.

(35) [Treatment Example 6]

(36) In this treatment example cellulose sulfate alone was attached to a through-air nonwoven fabric, and no other treatment was performed.

(37) The results of the hyaluronidase inhibitory activity test revealed that even before the storage test the inhibitory activity was less than 50%.

(38) The results of the hyaluronidase inhibitory activity test (% inhibitory activity) obtained in treatment examples 1 to 6 above are shown in Table 2 below.

(39) TABLE-US-00002 TABLE 2 Treatment Example 1 2 3 4 5 6 Before storage test 70 70 70 60 <10 <10 After storage test 70 70 <40 <40

INDUSTRIAL APPLICABILITY

(40) Because cellulose sulfate has antiviral properties, a fiber assembly retaining the same can be used as a sanitary material for medical uses such as masks, gowns, surgical gowns, etc., intended for antiviral applications. The fiber assembly of the present invention is not limited to the examples described above, and can be used in a variety of ways intended for antiviral applications.