A hydrophilic rubber, a method for preparing the same and use thereof

Abstract

The application discloses a kind of hydrophilic rubber and its preparation method and application, the hydrophilic rubber includes modified rubber, and the surface of the modified rubber is covered with hydrophilic polymer coating;The modified rubber is prepared by the following steps: isoprene rubber or natural rubber is treated with epoxidation reagent and strong oxidant.The modified rubber and hydrophilic polymer coating are covalently grafted by hydrogen bond complexation or by ester bond, ether bond, wherein the hydrogen bond is not easily destroyed by small molecule solvent by hydrophilic polymer coating, and hydrogen bond is conducive to improving the stability of hydrophilic coating, and cooperatively makes rubber keep hydrophilic lubricity.The hydrophilic rubber of the application has good biocompatibility, and has no irritation to skin.The hydrophilic rubber of the application can be applied to self-lubricating condom, and the surface coating of condom can greatly reduce the friction coefficient after being contacted with water, aqueous solution or body fluid.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of modified rubber, and particularly relates to a hydrophilic rubber as well as a preparation method and application thereof. BACKGROUND

[0002] Commercially sold condoms are mainly used for female contraception and prevention of sexually transmitted diseases during sexual intercourse. Since natural rubber condoms have the advantages of low price, strong elasticity and good skin feel, natural rubber condoms have always occupied the largest market share. However, the surface of natural rubber has high hydrophobicity, and when it directly contacts human skin or mucosa and slides relatively, high friction will cause discomfort or even pain to the user, causing tissue damage and increasing the risk of infection.

[0003] The most common way to increase the lubricity and usability of commercial natural rubber latex condoms is to coat the surface of the condom with an oily lubricant or an aqueous lubricant. Since oily lubricants can cause changes in the properties of natural rubber, are difficult to clean and leave residues in the female body that are difficult to decompose, they have been gradually eliminated from the market. Although aqueous lubricants overcome the above shortcomings of oily lubricants, the amount of lubricant added to the condom is limited, and the lubricant is diluted by body fluids and absorbed by the skin and mucosa during sexual intercourse, which is not enough to support the lubrication needs throughout the entire sexual intercourse, causing the condom to become dry and the friction to increase sharply during the later stages of sexual intercourse, resulting in a significant decrease in user experience.

[0004] To this end, the surface of the condom needs to be modified to improve its performance. CN110467741A discloses a technology for grafting zwitterionic polymers on the surface of a condom. This invention solves the lubrication problem during condom use, and obtains a hydrophilic coating on the surface of the condom with strong bonding force, stability and good lubricity, which can greatly improve the comfort of condom use. However, this invention still has some problems: 1. A new type of zwitterionic polymer material is used, which has certain safety risks; 2. Free radical initiation polymerization grafting technology is used, such as using benzophenone, azobisisobutyronitrile and other free radical initiators. The residues of these compounds on the surface of the condom will pose certain safety risks; 3. The grafting reaction time is 3-6 hours, which is too long for large-scale commercial production. Therefore, there is an urgent need to develop an environmentally friendly, safe, hydrophilic and rapidly prepared natural rubber latex condom. SUMMARY

[0005] In order to overcome the problems of the prior art, one of the purposes of the present application is to provide a hydrophilic rubber. The second purpose of the present application is to provide a preparation method of the above-mentioned hydrophilic rubber. The third purpose of the present application is to provide the application of the above-mentioned hydrophilic rubber.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0007] The present application provides a hydrophilic rubber in the first aspect, comprising a modified rubber, wherein the modified rubber is coated with a hydrophilic polymer coating; the modified rubber is prepared by a method comprising the following steps: treating isoprene rubber or natural rubber with an epoxidizing agent and a strong oxidizing agent.

[0008] Isoprene rubber or natural rubber is a kind of rubber material mainly composed of polyisoprene and containing a certain proportion of non-rubber substances such as protein, fatty acid, ash, sugar, etc. The chemical formula of polyisoprene is:

[0009]

[0010] The double bond of polyisoprene is a relatively active functional group, and the main reason for the aging of rubber is that the double bond is oxidized by oxygen in the air or ozone.

[0011] By utilizing the double bond characteristics of polyisoprene, the present application first oxidizes the olefin in polyisoprene into epoxy, vicinal diol and carboxylic acid, and the specific reaction formula is as follows:

[0012]

[0013] Then, a hydrophilic polymer with high safety which has been used in the market for a long time is grafted onto the surface of isoprene rubber or natural rubber through hydrogen bond, ether bond and ester bond to form a hydrophilic polymer coating. Under the condition of contacting water without additional lubricant, the lubricity of the isoprene rubber or natural rubber condom can be greatly improved, and the comfort and safety of the user can be satisfied at the same time.

[0014] Preferably, the material of the hydrophilic polymer coating is selected from one or more of polyvinyl alcohol, sodium polyacrylate, polyethylene oxide and sodium hyaluronate.

[0015] More preferably, the molecular weight of the polyvinyl alcohol is 170-220 million; the molecular weight of the sodium polyacrylate is 300-700 million; the molecular weight of the polyethylene oxide is 300-700 million; and the molecular weight of the sodium hyaluronate is 170-220 million.

[0016] Preferably, the epoxidizing agent is selected from one or more of inorganic peroxide, organic peroxy acid and inorganic peroxy acid; and the strong oxidizing agent is a permanganate oxidizing agent or a periodate oxidizing agent.

[0017] More preferably, the organic peroxy acid comprises one or more of peroxymethanoic acid, peroxyacetic acid, peroxybenzoic acid, meta-chloro peroxybenzoic acid, peroxytrifluoroacetic acid; the inorganic peroxy acid comprises peroxy sulfuric acid; the inorganic peroxide comprises one or more of hydrogen peroxide, potassium persulfate; the periodate oxidant comprises one or more of periodate, potassium periodate, sodium periodate.

[0018] The second aspect of the present application provides a method for preparing the hydrophilic rubber of the first aspect, comprising the following steps:

[0019] S1, dipping isoprene rubber or natural rubber in an aqueous solution of epoxidation reagent and performing reaction a; then dipping in an aqueous solution of strong oxidant and performing reaction b, to obtain the modified rubber;

[0020] or dipping isoprene rubber or natural rubber in an aqueous solution containing epoxidation reagent and strong oxidant and performing reaction c, to obtain the modified rubber;

[0021] S2, dipping the modified rubber in an aqueous solution of hydrophilic polymer and performing reaction d, to obtain the hydrophilic rubber.

[0022] Preferably, the concentration of peroxide in the aqueous solution of peroxide is 1-30 wt%. More preferably, the concentration of hydrogen peroxide in the aqueous solution of hydrogen peroxide is 1-30 wt%. More preferably, the concentration of peroxyacetic acid in the aqueous solution of peroxyacetic acid is 1-20 wt%. More preferably, the concentration of potassium persulfate in the aqueous solution of potassium persulfate is 1-20 wt%.

[0023] Preferably, the concentration of strong oxidant in the aqueous solution of strong oxidant is 0.5-20 wt%. More preferably, the concentration of potassium permanganate in the aqueous solution of potassium permanganate is 0.5-20 wt%. More preferably, the concentration of potassium periodate in the aqueous solution of potassium periodate is 1-10 wt%.

[0024] Preferably, the concentration of hydrophilic polymer in the aqueous solution of hydrophilic polymer is 0.05-10 wt%. More preferably, the concentration of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is 0.1-5 wt%. More preferably, the concentration of sodium polyacrylate in the aqueous solution of sodium polyacrylate is 0.1-3 wt%. More preferably, the concentration of polyethylene oxide in the aqueous solution of polyethylene oxide is 0.1-10 wt%. More preferably, the concentration of sodium hyaluronate in the aqueous solution of sodium hyaluronate is 0.05-0.5 wt%.

[0025] Preferably, when the aqueous solution of strong oxidant is a periodate oxidant, the composition of the aqueous solution of strong oxidant further comprises an acidic substance.

[0026] More preferably, the acidic substance is an inorganic acidic oxidant. Further preferably, the inorganic acidic oxidant is selected from one or more of potassium hydrogen persulfate, potassium persulfate, and sodium persulfate.

[0027] More preferably, the concentration of the acidic substance in the aqueous solution of the strong oxidant is 5-20 wt%.

[0028] Preferably, the pH value of the aqueous solution of the hydrophilic polymer is 2-5, more preferably 2-3. More preferably, dilute sulfuric acid, dilute hydrochloric acid, acetic acid, or propionic acid is used to adjust the pH value.

[0029] Preferably, the reaction time of the reaction a is 10-120 s; the reaction time of the reaction b is 10-120 s; and the reaction time of the reaction c is 10-120 s.

[0030] More preferably, the reaction time of the reaction a is 20-40 s; the reaction time of the reaction b is 40-80 s; and the reaction time of the reaction c is 40-80 s.

[0031] Preferably, the reaction time of the reaction d is 5-30 s.

[0032] More preferably, the reaction time of the reaction d is 5-20 s.

[0033] Preferably, the step S1 further comprises the following step: after the reaction b or the reaction c, the modified rubber is washed with water, and the time for the water washing is 3-10 s.

[0034] Preferably, the step S2 further comprises the following step: after the reaction d, the product is dried, and the drying temperature is 80-120℃.

[0035] Preferably, the isoprene rubber or the natural rubber is an isoprene rubber condom or a natural rubber condom.

[0036] More preferably, the method further comprises the following steps: before the dipping, the isoprene rubber condom or the natural rubber condom is sleeved on a mold; and after the dipping, the mold is removed.

[0037] The third aspect of the present application provides an application of the hydrophilic rubber of the first aspect in the preparation of a condom, a condom, or a finger cot.

[0038] The present application has the following beneficial effects:

[0039] (1) The present application provides a hydrophilic rubber, comprising a modified rubber and a hydrophilic polymer coating, the modified rubber and the hydrophilic polymer coating are covalently grafted by hydrogen bond complexation or by ester bond, ether bond, wherein the hydrophilic polymer coating makes the covalent bond not easy to be destroyed by water molecules, alcohol and other small molecule solvents, and the covalent bond is conducive to improving the stability and durability of the hydrophilic coating, both of which make the rubber can continuously maintain hydrophilic lubricity.

[0040] (2) The hydrophilic rubber of the present application uses a hydrophilic polymer with good biocompatibility and no skin irritation, and external use will not cause skin allergy.

[0041] (3) The hydrophilic rubber of the present application can be applied to self-lubricating condoms, and after the surface coating of the condom is contacted with water, aqueous solution or body fluid, the friction coefficient of the condom surface can be greatly reduced, and the coating has strong adhesion compared with traditional self-lubricating condoms, and can still provide low friction force after many friction cycles.

[0042] (4) The present application also provides a preparation method of the hydrophilic rubber, which does not need to use initiator, has no residual risk, and has short production time, and can realize large-scale rapid preparation. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Figure is the water contact angle test diagram of the self-lubricating condom of Example 4;

[0044] Figure 2 Figure is the water contact angle test diagram of the bare condom. DETAILED DESCRIPTION

[0045] The content of the present application is further described in detail through specific examples. In the following examples, the raw materials used, unless otherwise specified, can be obtained from conventional commercial channels or prepared and separated by simple synthesis; the processes used, unless otherwise specified, all use conventional processes in the art.

[0046] The condom bare condom used in the following examples and comparative examples is a natural rubber condom produced by Guangzhou Wanfangjian Medicine Co., Ltd., which does not add a hydrophilic polymer coating, and the material is natural rubber, the specification is: width 48-49mm, length 178-180mm, thickness 50-55μm.

[0047] Example 1

[0048] The present application provides a hydrophilic rubber, specifically a self-lubricating condom, and the preparation method is as follows:

[0049] 1. Solution preparation

[0050] Solution a1: 15% concentration of hydrogen peroxide aqueous solution;

[0051] Solution b1: aqueous solution containing 10% of potassium hydrogen persulfate and 3% of sodium periodate;

[0052] Solution c1: aqueous solution of polyvinyl alcohol (degree of alcoholysis 88%, molecular weight 180-200,000) at a concentration of 2% (pH adjusted to 2-3 with 0.1 mol / L dilute sulfuric acid);

[0053] wherein the concentration values are all mass percentage concentrations;

[0054] 2. Rubber modification

[0055] The bare sheath, which is fitted on the mold, is immersed in solution a1 for 30 seconds, taken out, and then immersed in solution b1 for 60 seconds, taken out, and the surface of the bare sheath is rinsed with flowing water for 5 seconds to obtain the modified rubber;

[0056] 3. Hydrophilic coating curing

[0057] The modified rubber is immersed in solution c1 for 10 seconds, taken out, and the condom together with the mold is dried in an oven at 80°C for 25 minutes, cooled after drying, demolded, and a self-lubricating condom is prepared.

[0058] Example 2

[0059] The present example provides a hydrophilic rubber, specifically a self-lubricating condom, and a preparation method thereof, which is specifically as follows:

[0060] 1. Solution preparation

[0061] Solution a2: aqueous solution of peroxoacetic acid at a concentration of 10%;

[0062] Solution b2: aqueous solution containing 15% of potassium hydrogen persulfate and 6% of potassium periodate;

[0063] Solution c2: aqueous solution of sodium polyacrylate (molecular weight 400-500 million) at a concentration of 1% (pH adjusted to 2-3 with 0.1 mol / L dilute hydrochloric acid);

[0064] wherein the concentration values are all mass percentage concentrations;

[0065] 2. Rubber modification

[0066] The bare sheath, which is fitted on the mold, is immersed in solution a2 for 30 seconds, taken out, and then immersed in solution b2 for 60 seconds, taken out, and the surface of the bare sheath is rinsed with flowing water for 5 seconds to obtain the modified rubber;

[0067] 3. Hydrophilic coating curing

[0068] The modified rubber is immersed in solution c2 for 10 seconds, taken out, and the condom together with the mold is dried in an oven at 90°C for 20 minutes, cooled after drying, demolded, and a self-lubricating condom is prepared.

[0069] Example 3

[0070] This example provides a hydrophilic rubber, specifically a self-lubricating condom, and its preparation method is as follows:

[0071] 1. Solution preparation

[0072] Solution a3: 10% potassium permanganate aqueous solution;

[0073] Solution b3: 20% potassium persulfate and 10% periodic acid aqueous solution;

[0074] Solution c3: 5% polyethylene oxide (molecular weight 40-50 million) aqueous solution (pH adjusted to 2-3 with 0.5 mol / L acetic acid);

[0075] Wherein, the concentration values all refer to mass percentage concentration;

[0076] 2. Rubber modification

[0077] The bare condom on the mold is immersed in solution a3 for 30 seconds, taken out, and then immersed in solution b3 for 60 seconds, taken out, and the surface of the bare condom is rinsed with flowing water for 5 seconds to obtain a modified rubber;

[0078] 3. Hydrophilic coating curing

[0079] The modified rubber is immersed in solution c3 for 10 seconds, taken out, and the condom together with the mold is dried in an oven at 100°C for 15 minutes, cooled after drying, demolded, and a self-lubricating condom is prepared.

[0080] Example 4

[0081] This example provides a hydrophilic rubber, specifically a self-lubricating condom, and its preparation method is as follows:

[0082] 1. Solution preparation

[0083] Solution a4: 25% hydrogen peroxide aqueous solution;

[0084] Solution b4: 5% potassium persulfate and 1% sodium periodate aqueous solution;

[0085] Solution c4: 0.2% sodium hyaluronate (molecular weight 180-200 million) aqueous solution (pH adjusted to 2-3 with 0.5 mol / L propionic acid);

[0086] Wherein, the concentration values all refer to mass percentage concentration;

[0087] 2. Rubber modification

[0088] The bare sheath on the mold is immersed in solution a4 for 30 seconds, taken out, and then immersed in solution b4 for 60 seconds, taken out, and the surface of the bare sheath is rinsed with flowing water for 5 seconds to obtain a modified rubber;

[0089] 3. Hydrophilic coating curing

[0090] The modified rubber is immersed in solution c4 for 10 seconds, taken out, and the condom is dried together with the mold in an oven at 120°C for 8 minutes, cooled after drying, demolded, and a self-lubricating condom is prepared.

[0091] Example 5

[0092] The present example provides a hydrophilic rubber, in particular a self-lubricating condom, and a preparation method thereof, which specifically comprises the following steps:

[0093] 1. Solution preparation

[0094] Solution b4: an aqueous solution containing 5% potassium hydrogen persulfate and 1% sodium periodate;

[0095] Solution c4: an aqueous solution of sodium hyaluronate (molecular weight 1.8-2 million) with a concentration of 0.2% (pH=2-3 is adjusted by 0.5 mol / L propionic acid);

[0096] The concentration values all refer to mass percentage concentration;

[0097] 2. Rubber modification

[0098] The bare sheath on the mold is immersed in solution b4 for 60 seconds, taken out, and the surface of the bare sheath is rinsed with flowing water for 5 seconds to obtain a modified rubber;

[0099] 3. Hydrophilic coating curing

[0100] The modified rubber is immersed in solution c4 for 10 seconds, taken out, and the condom is dried together with the mold in an oven at 120°C for 8 minutes, cooled after drying, demolded, and a self-lubricating condom is prepared.

[0101] Comparative Example 1

[0102] The present comparative example provides a water-lubricating condom, which is not modified compared to Example 4, and the difference from Example 4 is only that the bare sheath on the mold is not immersed in solution a4 and solution b4, and the remaining steps are consistent, i.e., the bare sheath on the mold is rinsed with flowing water and then subjected to hydrophilic coating curing.

[0103] Comparative Example 2

[0104] The present comparative example provides a water-lubricating condom, which is not modified compared to Example 4, and the difference from Example 4 is only that the bare sheath on the mold is not immersed in solution a4, solution b4 is replaced by an aqueous solution of potassium permanganate with a concentration of 25%, and the immersion time in solution b4 is 100 seconds, and the remaining steps are consistent.

[0105] Comparative Example 3

[0106] This comparative example provides a water-wettable condom, which is modified with a low concentration solution compared to Example 4, and the only difference from Example 4 is that solution a4 is replaced by a 0.5% hydrogen peroxide aqueous solution, and solution b4 is replaced by an aqueous solution containing 0.5% potassium persulfate and 0.5% sodium periodate, and the rest of the steps are the same.

[0107] Comparative Example 4

[0108] This comparative example provides a water-wettable condom, which is modified with a low concentration solution compared to Example 4, and the only difference from Example 4 is that solution a4 is replaced by a 0.5% hydrogen peroxide aqueous solution, and solution b4 is replaced by an aqueous solution containing 0.5% potassium persulfate and 0.5% sodium periodate, and the rest of the steps are the same.

[0109] Comparative Example 5

[0110] This comparative example provides a water-wettable condom, which is modified with a reduced modification time compared to Example 4, and the only difference from Example 4 is that solution b4 is replaced by a 25% potassium permanganate aqueous solution, and the immersion time in solution a4 is kept at 3 seconds, and the immersion time in b4 is kept at 6 seconds, and the rest of the steps are the same.

[0111] Performance Test and Results

[0112] 1. Water contact angle, bursting capacity and bursting pressure test

[0113] The water contact angle of the self-lubricating condoms of Examples 1-5 and the bare condom (the bare condom is a condom that has not been treated in any way, and the same applies below) and Comparative Examples 1-5 was measured using a German Kruss DSA25 contact angle measuring instrument, Figure 1 is a water contact angle test diagram for the self-lubricating condom of Example 4, Figure 2 is a water contact angle test diagram for the bare condom, and the specific results are shown in Table 1;

[0114] Table 1

[0115]

[0116]

[0117] The bursting capacity and bursting pressure of the self-lubricating condoms of Examples 1-5 and the bare condom were tested in accordance with the GB / T 7544-2019 standard, and the specific results are shown in Table 2:

[0118] Table 2

[0119]

[0120] From the data in Table 1 and Table 2, it can be seen that after hydrophilic modification, the condom with hydrophilic coating solidification has a significant decrease in water contact angle, and the hydrophilicity of the condom surface is greatly improved. At the same time, after the accelerated aging test, the burst capacity and burst pressure of all samples meet the requirements of GB / T 7544-2019, indicating that the product condom after hydrophilic modification still has excellent durability and anti-burst ability, ensuring that it will not cause safety risks due to accidental rupture during use.

[0121] 2. Dynamic friction test

[0122] The dynamic friction coefficient of the condom samples prepared in Examples 1-5 and the bare condom was determined according to the method of GB 10006-2021. Specifically, the condom-covered stainless steel mold was placed in a container containing physiological saline (water temperature 37℃), vertically fixed on a friction coefficient instrument (test range 0-5 Newton), and a clamp coated with rubber was used to apply a force of 2 Newton to the surface of the condom on the stainless steel mold. When the mold moved at a speed of 150 mm / min, the clamp reciprocated on the surface of the condom on the mold for 500 times, with a single movement distance of 120 mm. The dynamic friction coefficient was determined, and the test results are shown in Table 3:

[0123] Table 3

[0124]

[0125] As can be seen from the data in Table 3, the condom containing the lubricating coating obtained in Examples 1-5 has a relatively stable friction coefficient during the cycle sliding process of the clamp, which increases with the number of times. This indicates that the coating is firm and rarely falls off, especially the friction coefficient of Examples 4-5 is still less than 0.1 after 300 cycles. The bare condom without any treatment has a much higher friction coefficient than the condom with lubricating coating and ruptures after about 150 cycles.

[0126] From the experimental data in Table 3, it can be seen that the product prepared in Example 4 using sodium hyaluronate as the lubricating component has the best coating firmness. By comparing the structural features of the hydrophilic polymers used in the examples (see Table 4), it can be inferred that under acidic conditions, during the heating and curing of the condom, the sodium hyaluronate, which contains a large number of hydroxyl and carboxyl groups, is more likely to form ester or ether reactions with the certain amount of hydroxyl and carboxyl groups on the surface of the condom produced by oxidation, forming more covalent bond grafting effects. Polyvinyl alcohol only contains a large number of hydroxyl groups, and polyethylene oxide only contains hydroxyl groups at the end. The conditions for these two high-molecular-weight polymers to form ether bonds with the newly formed hydroxyl groups on the surface of the condom are relatively difficult. Sodium polyacrylate only contains a large number of carboxyl groups, which can form a certain amount of ester bonds. The four high-molecular-weight polymers all contain a large number of functional groups that can form hydrogen bonds: hydroxyl / carboxyl groups. The products obtained in the four examples have strong hydrogen bonds between the coating molecules and the condom, in addition to covalent grafting, which makes the hydrophilic high-molecular-weight polymers have strong adhesion on the surface of the condom.

[0127] Table 4

[0128]

[0129]

[0130] The dynamic friction coefficients of the condom samples of Comparative Examples 1-5 and the bare condom were measured using the same method, and the reciprocating motion was reduced to 30 times. The test results are shown in Table 5:

[0131] Table 5

[0132]

[0133] From the data in Table 5, the following conclusions can be drawn: (1) Comparative Example 1, the condom surface is not treated with any oxidation and directly immersed with the hydrophilic polymer solution and dried. Since the condom natural rubber surface lacks a large number of hydroxyl, carboxyl, carbonyl and other functional groups that can form strong hydrogen bonding and ether and ester, the adhesion of the hydrophilic polymer is very weak, and after 10 cycles of the clamp, the hydrophilic polymer lubricating coating is basically completely detached; (2) Comparative Example 2, when using peroxide treatment without using potassium persulfate / periodate compound, the peroxide bond or hydroxyl formed on the surface of the condom natural rubber is insufficient, and it is still difficult to form a strong enough hydrogen bond and ether with the hydrophilic polymer, and there is no carboxyl to provide ester conditions, after 20 cycles of the clamp, the hydrophilic polymer lubricating coating is basically completely detached; (3) Comparative Example 3, when using peroxide to pre-treat the surface of the condom, other commonly used strong oxidizing agents such as sodium hypochlorite are used, the hydroxyl and chloro can be formed on the surface of the condom natural rubber, but the key carboxyl cannot be formed, and the lubricating coating has been obviously detached after 30 cycles of the clamp; (5) Comparative Examples 4 and 5, when the concentration of the oxidation solution is too low and the immersion time is too short, the lubricating coating is easily detached.

[0134] In summary, the combination of epoxidation reagent and strong oxidizing agent for treating the surface of the condom can make the condom well combined with the hydrophilic polymer.

[0135] 3. Mechanical property test

[0136] The tensile strength and elongation of the self-lubricating condoms of Examples 1-5 and the bare condoms were tested according to the standard GB / T 7544-2019, and the results are shown in Table 6:

[0137] Table 6

[0138]

[0139] The results in Table 6 show that the condoms of Examples 1-5 have high tensile strength and elongation after hydrophilic modification, and are not easy to break or damage.

[0140] 4. Biological toxicity test

[0141] The condom samples obtained from Examples 1-5 and Comparative Examples 1-5 were tested according to the standards GB / T 16886.5-2017 (Biological Evaluation of Medical Devices Part 5: In Vitro Cytotoxicity Test) and GB / T 14233.2-2005 (Part 2: Biological Test Methods):

[0142] (1) Main materials and reagents:

[0143] Cell line: L929 mouse fibroblast (Shanghai Cell Bank of Chinese Academy of Sciences), RPMI1640 medium (GIBCO), dimethyl sulfoxide (DMSO, Meril), CO2 incubator (Therm HERA cell 150i), inverted microscope (Nikon TE2000-U), constant temperature water bath.

[0144] Preparation of leaching solution:

[0145] Sample group: According to GB / T 16886.12-2017, the condom sample was leached according to the ratio of 6 cm 2 / mL, 4.5 cm 2 / mL, 3 cm 2 / mL, 1.5 cm 2 / mL, 0.6 cm 2 / mL at 37±1℃ for 24h. The leaching medium was RPMI1640 medium containing 10% serum.

[0146] Negative group: High-density polyethylene was leached according to the ratio of 0.2 g / mL, and the conditions were the same as the sample group.

[0147] Positive group: Natural rubber material was leached with RPMI1640 medium containing 5% DMSO and 10% serum, and the conditions were the same as the sample group.

[0148] Test method (microscopic observation according to GB / T 14233.2-2005):

[0149] Blank group, negative group, positive group, sample group were set. The L929 cells which had been cultured for 72h and grew vigorously were digested and added to cell culture solution to prepare 1×10 5 / mL cell suspension, inoculated in 6-well cell culture dishes, 2mL per well. Each group was operated in parallel for 3 wells, and placed in a CO2 incubator (37±1)℃ for culture until the single layer cells were 70% confluent. The original solution was discarded, and 2mL of corresponding test solution (blank group, negative group, positive group, sample leaching solution of different concentrations) was added to each well, respectively, and placed in a CO2 incubator for continuous culture for 72h, and observed under a microscope.

[0150] It should be noted that according to GB / T 16886.5-2017 test, all leaching concentrations in the table need to be covered. Since the condom tested only has a single side hydrophilic coating, the protein and other impurities brought in by the dissolved natural rubber on the side without coating will definitely affect cell growth, so the result of severe level will appear.

[0151] (2) The experimental results are shown in Table 7:

[0152] Table 7

[0153]

[0154]

[0155] From the data in Table 7, some substances harmful to cells in the bare condom without lubricating coating covering were leached out, the coating adhesion of Comparative Examples 1-5 was poor, the coating gradually fell off during the 24h leaching process, and then some substances harmful to cells in the natural rubber were leached out, which caused a relatively major impact on cell growth and caused cytotoxicity.

[0156] Examples 1-5 are samples with firm lubricating coating, because the coating covers one side of the condom sample, impurities harmful to cells will not be dissolved out during leaching, so the test results are better than those of bare condoms. At a concentration of 4.5 cm 2 / mL, the degree of reaction has been reduced from severe to moderate, at a concentration of 1.5 cm 2 / mL and below, there is no toxicity.

[0157] All the sample of examples and comparative examples of the present application are also detected according to the standard GB / T 16886.10-2017 "Medical devices-Biological evaluation Part 10: Tests for irritation and skin sensitization" and the standard GB 15979-2002 "Hygienic standard for disposable sanitary products". The test results show that all the condoms meet the requirements of the above standards.

[0158] The above is the preferred embodiment of the present application, it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements also considered as the protection scope of the present application.

Claims

1. A hydrophilic rubber, characterized in that, This includes modified rubber, the surface of which is covered with a hydrophilic polymer coating; the hydrophilic rubber is prepared by a method comprising the following steps: S1. Impregnate isoprene rubber or natural rubber in an aqueous solution of an epoxidizing agent and carry out reaction a; then impregnate it in an aqueous solution of a strong oxidizing agent and carry out reaction b to obtain the modified rubber. The reaction times of reactions a and b are independently 10–120 s; After reaction b is completed, the modified rubber is washed with water for 3-10 seconds. S2. The modified rubber is impregnated in a hydrophilic polymer aqueous solution and reacted for d to obtain the hydrophilic rubber. The epoxidizing agent is selected from one or more of inorganic peroxides and organic peroxy acids; the organic peroxy acids include one or more of peroxyformic acid, peracetic acid, perbenzoic acid, m-chloroperoxybenzoic acid, and pertrifluoroacetic acid; the inorganic peroxides include one or more of persulfate, hydrogen peroxide, and potassium persulfate. The strong oxidizing agent is a periodic acid-based oxidizing agent; the periodic acid-based oxidizing agent includes one or more of periodic acid, potassium periodate, and sodium periodate; when the aqueous solution of the strong oxidizing agent also includes an acidic substance; the acidic substance is an inorganic acidic oxidizing agent, and the inorganic acidic oxidizing agent is selected from one or more of potassium persulfate, potassium persulfate, and sodium persulfate; The concentration of the epoxidizing agent in the aqueous solution of the epoxidizing agent is 10~30wt%; the concentration of the strong oxidizing agent in the aqueous solution of the strong oxidizing agent is 0.5~20wt%.

2. The hydrophilic rubber according to claim 1, characterized in that, The hydrophilic polymer coating material is selected from one or more of polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, and sodium hyaluronate.

3. The hydrophilic rubber according to claim 2, characterized in that, The molecular weight of the polyvinyl alcohol is 170,000-220,000; the molecular weight of the sodium polyacrylate is 3,000,000-7,000,000; the molecular weight of the polyethylene oxide is 3,000,000-7,000,000; and the molecular weight of the sodium hyaluronate is 1,700,000-2,200,000.

4. The method for preparing the hydrophilic rubber according to any one of claims 1-3, characterized in that, Specifically, the steps include the following: S1. Impregnate isoprene rubber or natural rubber in an aqueous solution of an epoxidizing agent and carry out reaction a; then impregnate it in an aqueous solution of a strong oxidizing agent and carry out reaction b to obtain the modified rubber. The reaction times of reactions a and b are independently 10–120 s; After reaction b is completed, the modified rubber is washed with water for 3-10 seconds. S2. The modified rubber is impregnated in a hydrophilic polymer aqueous solution and reacted for d to obtain the hydrophilic rubber. The epoxidizing agent is selected from one or more of inorganic peroxides and organic peroxy acids; the organic peroxy acids include one or more of peroxyformic acid, peracetic acid, perbenzoic acid, m-chloroperoxybenzoic acid, and pertrifluoroacetic acid; the inorganic peroxides include one or more of persulfate, hydrogen peroxide, and potassium persulfate. The strong oxidizing agent is a periodic acid-based oxidizing agent; the periodic acid-based oxidizing agent includes one or more of periodic acid, potassium periodate, and sodium periodate; when the aqueous solution of the strong oxidizing agent also includes an acidic substance; the acidic substance is an inorganic acidic oxidizing agent, and the inorganic acidic oxidizing agent is selected from one or more of potassium persulfate, potassium persulfate, and sodium persulfate; The concentration of the epoxidizing agent in the aqueous solution of the epoxidizing agent is 1~30wt%; the concentration of the strong oxidizing agent in the aqueous solution of the strong oxidizing agent is 0.5~20wt%.

5. The method for preparing hydrophilic rubber according to claim 4, characterized in that, The concentration of the hydrophilic polymer aqueous solution is 0.05~10wt%.

6. The method for preparing hydrophilic rubber according to claim 4, characterized in that, The pH value of the hydrophilic polymer aqueous solution is 2~5.

7. The method for preparing hydrophilic rubber according to claim 6, characterized in that, The pH value of the hydrophilic polymer aqueous solution is adjusted using dilute sulfuric acid, dilute hydrochloric acid, acetic acid, or propionic acid.

8. The method for preparing hydrophilic rubber according to claim 4, characterized in that, The reaction time of reaction d is 5~30 s.

9. The use of the hydrophilic rubber according to any one of claims 1-3 in the preparation of condoms, safety condoms or finger cots.

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