CN111072902A

CN111072902A - Multilayer condom containing modified polyurethane raw material and preparation method thereof

Info

Publication number: CN111072902A
Application number: CN201911389641.XA
Authority: CN
Inventors: 叶恒; 刘灯旺; 艾婷婷; 张丽娜
Original assignee: Meishan Youborui New Material Co Ltd
Current assignee: Meishan Youborui New Material Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-28
Anticipated expiration: 2039-12-30
Also published as: CN111072902B

Abstract

The invention provides a multilayer condom containing a modified polyurethane raw material and a preparation method thereof. The condom is of a multilayer sandwich type, and the preparation method comprises the following steps: (1) preparing an inner-layer adhesive film: reacting polyisocyanate with a chain extender to obtain fluorine-containing silicon-containing polyurethane emulsion, and then preparing a membrane; (2) preparing an intermediate layer adhesive film: prepared by blending polyisoprene rubber and modified polyurethane emulsion; (3) preparing an outer-layer adhesive film: the modified rosin resin latex is prepared by maleic rosin through emulsion polymerization, and then the modified rosin resin latex is blended with modified polyurethane emulsion and polyisoprene rubber emulsion to prepare a film; (4) and carrying out edge curling and demoulding forming to obtain a finished product. The multilayer condom obtained by the invention has no special smell and anaphylactic reaction, has high tensile strength, high elongation at break, good toughness and high resilience rate, has good bacteriostatic action on various common bacteria, has efficient barrier property on small molecules, can be well processed and produced, and has good application prospect.

Description

Multilayer condom containing modified polyurethane raw material and preparation method thereof

Technical Field

The invention belongs to the technical field of contraceptive tools, and particularly relates to a multilayer condom containing a modified polyurethane raw material and a preparation method thereof.

Background

The condom is a non-medicine mode for preventing pregnancy, is the most common contraceptive tool used in the world, and according to incomplete statistics, the consumption of the condom is nearly 120 hundred million per year in China. At present, the condom is not only a birth control tool, but also one of the most effective methods for preventing the spread of sexually transmitted diseases, and along with the rapid spread of the sexually transmitted diseases such as AIDS, the work situation for preventing and treating AIDS is increasingly severe, and the quality of the condom product is more and more emphasized.

The main raw material for manufacturing condoms is natural rubber latex which always dominates the field of latex products, and according to related reports, the consumption of the natural rubber latex is more than 1000kt per year at present, wherein more than 40 percent of the natural rubber latex is used for producing condoms. The natural latex has unique excellent performance in the aspect of producing condoms, and has simple production process, easy gelatinization, easy vulcanization and good film forming property; the product has the advantages of large elasticity, high strength, small creep, excellent comprehensive performance and small influence on human bodies. However, natural latex contains many non-rubber components such as allergic water-soluble protein and other biological macromolecules, and if the content of the water-soluble protein in the latex exceeds a certain content, the skin of a user can generate allergic reactions such as erythema, pruritus and the like, and many serious allergic people can even generate life-threatening twitching, shivering and the like. Since the 80's of the 20 th century, natural latex medical hygiene products have caused frequent allergic events in humans, while in the United states, it is estimated that about 1700 thousands of people have become allergic to natural latex, in 1992, the U.S. Federal food and drug administration has warned the sensitization of natural rubber, and scientists have subsequently attempted to reduce the sensitization of natural rubber by various means, but the success has been marginal and, to date, the problem of sensitization of natural rubber has not been well solved. On the other hand, condoms made of natural rubber also suffer from the following drawbacks: odorous, low resistance to oil-based lubricants, and rapid strength loss.

In addition, natural cracks of the natural latex are 5000-. Meanwhile, the condom is produced by taking natural latex as a raw material and needs to be vulcanized, and the condom can generate nitrosamine in the process, and the substance has strong carcinogenicity. It is affected by various oil-based lubricants, and when condoms are used, carcinogens come into contact with human body fluids, and the resulting nitrosamines alkylate DNA, with the risk of eventually causing cancer. Therefore, the search for a more innovative material for producing condoms is a necessary trend in the development of condoms.

In view of the above disadvantages of natural rubber, the current disadvantages of natural rubber are not well solved, which has prompted technologists to develop research and development on synthetic latex to replace natural latex in the field of producing medical and health products such as condoms and medical gloves.

In the field of synthetic rubber, the performance of polyisoprene rubber is most similar to that of natural rubber, and the polyisoprene rubber has a pure system, does not contain non-rubber components and does not cause protein anaphylactic reaction of a human body, so that the polyisoprene rubber is particularly suitable for manufacturing articles contacting with the skin of the human body. The synthetic latex can well solve the problem of human allergy caused by natural latex products, is the best choice for replacing natural latex, but because the polyisoprene rubber has poor processing performance, such as being much worse than natural rubber in mixing and calendering, the clinical breakage rate of producing non-natural latex condoms is obviously higher than that of natural latex condoms, and the trend that the synthetic latex replaces the natural latex is delayed; on the other hand, in an attempt to prepare a synthetic rubber using cis-1, 4-polyisoprene, which is a main component of natural rubber, it was found that although the problem of allergic reaction was well solved, the resulting condom product lacked tensile properties, which were low in elongation at break, and tensile properties were important characteristics of condom products, which resulted in a decrease in mechanical strength. For example, US3917746 acknowledges that products made of unmodified cis-1, 4-polyisoprene cause damage when the cured product is removed from the mould and leave streaks and grooves in the rubber film, causing defects in mechanical strength. Subsequent reports show that the tensile strength of the condom product is obviously reduced while the elongation at break of the condom product is improved by adopting various treatment modes.

US 3215649 discloses a process for curing polyisoprene rubber lattices by using sulphur and zinc alkyl dithiocarbamates and zinc mercaptobenzothiazole with zinc oxide as activators, the latex being pre-vulcanized for 72 hours at 40 ℃ or 16 hours at 50 ℃ to a suitable cross-link density, the ultimate tensile strength value being 460psi (about 3MPa), which is however far from sufficient for condoms. US 6618861 discloses a method for making a glove having a transparent wrist portion from a material comprising a polyisoprene latex, which in example 2 gives a formulation for a polyisoprene latex comprising five accelerators (tetramethylthiuram disulphide, zinc 2-mercaptobenzothiazole, zinc dibutyldithiocarbamate, zinc diethyldithiocarbamate and 1, 2-diphenyl-2-thiourea), and sulphur and zinc oxide as vulcanising agents, and a film made from this polyisoprene latex having tensile properties: the tensile strength is 13.22MPa, the elongation at break is 1028%, and the stress at 300% strain is 1.03MPa, the tensile strength obtained by this method is still insufficient for condoms. WO02/090430 discloses a method for making polyisoprene articles using a novel three-part accelerator system comprising dithiocarbamate, thiazole and guanidine compounds. It is also specifically noted in this document that the omission of any of the three preferred accelerator components results in a significant reduction in tensile strength: it has thus been demonstrated that the tensile strength of the resulting polyisoprene article is critically related to the composition of the three-part accelerator. However, the search for these accelerators and the research on their functions are difficult, and how to solve the problems caused by replacing natural rubber with synthetic rubber by reducing the accelerator components or not using the accelerators becomes a great problem to be solved, and a condom product which not only has high tensile strength but also ensures high elongation at break is obtained.

Since the 90 s of the 20 th century, as a new type of polyurethane condom was developed, the development of condom research has rapidly changed, and latex condoms are increasingly replaced by polyurethane condoms. Compared with latex condoms, the polyurethane condom has the characteristics of no toxicity, high strength, good thermal conductivity, good toughness of a condom film, no special smell, no anaphylactic reaction and the like, is insensitive to heat, humidity and ultraviolet light, has good aging resistance, is not influenced by various oil-based lubricants in the storage process, cannot greatly reduce the physical performance of a product, and is a condom safe and comfortable to use. Polyurethane condoms have improved the problem of relatively low tensile strength of synthetic polyisoprene rubber condoms, as disclosed in CN110279507A, a polyurethane condom having a thickness of between 0.010mm and 0.030mm, capable of having an elongation at break in the range of 600% to 1000% and having a tensile strength in the range of 15MPa to 45 MPa. However, CN101432342B reports that although polyurethane can have high tensile strength, it lacks the resilience and low tensile set value of natural rubber. Thus, it has been found that for many applications of natural rubber, polyurethanes are not suitable.

Most of the existing condom products can be divided into natural rubber condoms, polyisoprene condoms and polyurethane condoms, which have unique advantages, but each condom has certain defects to be improved, and modification of each component and mutual overlapping use of multiple components are also studied in order to improve the performance of a glue film, but various defects which are shown are still shown. For example, Chowdhury and the like blend natural latex and butyronitrile latex, so that the oil resistance of the adhesive film is improved by 34 percent, but the physical property of the adhesive film is reduced by 7 percent. Zengxiajun and the like blend the waterborne polyurethane and the polyacrylate, and the tensile strength of the PU/PA blended adhesive film is larger than that of PU, but the elongation at break is greatly reduced, and the film becomes harder. The experimental result shows that the tensile strength of the grafted latex is higher than that of the common natural latex, and the elongation at break is reduced to some extent.

The modification of various condom adhesive film materials is still under study at present, but a condom which can have the advantages of the three condoms does not exist at present, the tensile strength of a condom adhesive film can be improved by a modification method, the elongation at break of the condom adhesive film can be obviously improved, the mechanical property and the service performance of the condom can be well ensured, the defects of the three condom materials at present are overcome, and the technical problem to be solved urgently is solved.

Disclosure of Invention

Under the background, the invention aims to overcome the defects of the existing condom product and provide a multilayer condom containing modified polyurethane raw materials and a preparation method thereof. The multilayer condom product provided by the invention has no special smell and anaphylactic reaction, has high tensile strength, high elongation at break, good toughness, small permanent deformation, high rebound rate, easy demoulding, tear resistance, good antibacterial property and good virus blocking effect, can be well processed and produced, and has good application prospect.

One of the purposes of the invention is to provide a preparation method of a multilayer condom containing a modified polyurethane raw material, which sequentially comprises the following steps:

(1) preparing an inner-layer adhesive film:

according to weight percentage, mixing 15-40% of diisocyanate, 40-80% of polymer diol, 0.1-15.0% of polysiloxane diol, 0.4-5.0% of fluorine-containing chain extender, 1-5% of chain extender I and 1-10% of hydrophilic chain extender, then carrying out polymerization and emulsification to prepare fluorine-containing silicon-containing aqueous polyurethane emulsion, diluting until the solid content is 25-30%, soaking a rod-shaped mould into the polyurethane emulsion, taking out, drying at 80-95 ℃ for 5-10min, and forming a first layer of glue film on the rod-shaped mould;

(2) preparing an intermediate layer adhesive film:

A. carrying out emulsion polymerization reaction on diisocyanate, polymer dihydric alcohol, a modified polyurethane chain extender and a hydrophilic chain extender according to the molar ratio of 3:2:0.5:0.5 to prepare a polyurethane emulsion, wherein the molecular weight range of the polyurethane emulsion is 80000-150000, the solid content of the polyurethane emulsion is 25-35%, and the synthetic method of the modified polyurethane chain extender comprises the following steps: performing amino protection on lysine through tert-butyloxycarbonyl, then reacting the lysine with N-N-hydroxysuccinimide for 5-6h at normal temperature, then reacting with dopamine hydrochloride for 10-12h at normal temperature to obtain an intermediate product, and reacting the intermediate product with hydrochloric acid for 2-3h at normal temperature to remove amino protecting groups to obtain the modified polyurethane chain extender, wherein the structural formula of the modified polyurethane chain extender is as follows:

B. dissolving cis-1, 4-polyisoprene rubber in an organic solvent, adding an emulsifier under high-speed stirring for emulsification, removing the organic solvent, and pre-vulcanizing to obtain a polyisoprene emulsion with the solid content of 30-35%;

C. b, blending the polyurethane emulsion obtained in the step A and the polyisoprene emulsion obtained in the step B, wherein the weight percentage of the polyurethane emulsion to the polyisoprene emulsion in a blending system is 10-20% to 90-80%, and the solid content in the blending system is 28-32%, then soaking a rod-shaped mould with a first layer into the blending emulsion, taking out the mould, drying the mould at 80-95 ℃ for 5-10min, and forming a second adhesive film on the surface of the first adhesive film;

(3) preparing an outer-layer adhesive film:

D. performing esterification reaction on maleic rosin and allyl alcohol at the temperature of 110 ℃ according to the molar ratio of 1:4 to obtain maleic rosin allyl alcohol ester, then adding an emulsifier OP-10 into water, stirring to obtain a pre-emulsion, heating to 60 ℃, adding an acrylic monomer, maleic rosin allyl alcohol ester and an initiator, wherein the mass ratio of the acrylic monomer to the maleic rosin allyl alcohol ester is 1:3, heating in a water bath to 85 ℃, and performing emulsion polymerization reaction to prepare a rosin modified resin emulsion with the solid content of 15-30%;

E. blending the polyurethane emulsion and the polyisoprene emulsion respectively obtained in the step A, B and the rosin modified resin emulsion obtained in the step D, wherein the weight percentage of the rosin modified resin emulsion, the polyurethane emulsion and the polyisoprene emulsion in the blended emulsion is 10-20%, 70-50%, 20-30%, and the solid content in the blended emulsion is 25-30%, then soaking the rod-shaped mold in the blended emulsion, taking out and drying at 90-100 ℃ for 5-10min to form a third adhesive film;

(4) carrying out edge curling, demoulding, forming and vulcanization on the formed adhesive film, inspecting by a pinhole, and packaging to obtain a condom package;

wherein the thickness ratio of the inner-layer adhesive film to the middle-layer adhesive film to the outer-layer adhesive film is controlled to be 1:3: 1.5.

The condom with the three-layer rubber film structure is prepared according to the method, and comprises a polyurethane layer, a middle rubber film layer prepared by blending modified polyurethane and polyisoprene, and an outer layer prepared by blending polyurethane, polyisoprene and rosin modified resin emulsion. The traditional condom product is in a single-layer structure and a double-layer structure at first, but the physical performance of the condom is poor, the elastic modulus is low, the breakage rate is high, the anti-permeation and blocking effects on bacteria and viruses are generally poor, and particularly the viruses with small particle sizes cannot be blocked. Although the condom products with multilayer sandwich structure have been developed by people, for example, patent CN 107057129B discloses a sandwich polyurethane modified acrylate condom, the middle two layers are made of organosilicon modified polyurethane material, the obtained condom has the characteristics of high barrier property and high strength, the burst volume and burst pressure of the condom are evaluated in the second embodiment, but the obtained condom has insufficient tensile strength and elongation, poor resilience, insufficient adhesive property between each layer of glue film, relative independence between each layer, and no complete whole body, and is easy to be damaged when taken down from a mold, and the disadvantages of the polyurethane condom are not solved.

After a large number of experimental researches, the inventor of the invention discovers that the condom prepared by the method disclosed by the invention is distributed according to the three-layer adhesive film structure, so that the obtained condom product has higher tensile strength, the elongation at break of the condom product is greatly improved, meanwhile, the obtained condom product has good rebound resilience and small permanent deformation, is easy to demould from a mould, and also shows excellent performances in the aspects of antibiosis and virus barrier, and in addition, the surface of the obtained condom is smooth and transparent, and the obtained condom product has excellent friction and wear resistance under high-speed sliding.

The inner-layer adhesive film is prepared from the fluorine-containing and silicon-containing polyurethane emulsion, can effectively improve the problems of surface property, water resistance and the like of the waterborne polyurethane through the synergistic effect of the fluorine and the silicon which migrate to the surface in the film forming process, simultaneously improves the surface property of the waterborne polyurethane adhesive film layer, is beneficial to demoulding, and improves the comprehensive performance of waterborne polyurethane film products. On the other hand, the middle film layer of the condom is prepared by adopting a modified polyurethane chain extender to obtain polyurethane emulsion and then is blended with polyisoprene rubber emulsion to obtain the condom product, wherein the hydrophilicity of the polyurethane layer is increased due to the increase of catechol groups in polyurethane, and on the other hand, the viscosity of the condom is greatly increased, compared with unmodified polyurethane, the peel strength of the condom is improved by more than 300%, and excellent adhesion performance is shown. The antibacterial layer is prepared by blending the polyurethane emulsion, the polyisoprene emulsion and the rosin modified resin emulsion on the outer layer of the condom, the antibacterial property of the obtained condom is greatly improved due to the special phenanthrene ring framework in the rosin resin structure, the tensile strength of the condom is improved, and the barrier property of the condom against viruses is excellent.

The preparation method of the invention has the advantages of simpler processing of the condom with the multilayer sandwich structure and more controllable preparation process, and well solves the defects of poor processing performance, poor mixing and calendering effects and high breakage rate caused by adopting synthetic rubber to prepare the condom. The condom product obtained by the invention can well ensure the mechanical strength of the product, and can also solve the problems that the existing synthetic rubber has poor tensile property and low elongation at break compared with natural rubber, and is easy to damage when being taken down from a mould.

The invention well solves the defects brought by the replacement of natural rubber by the existing synthetic rubber, and simultaneously, because the condom with a multilayer sandwich structure is easy to have reduced sensitivity to skin, the surface of the film is easy to become rough and unsmooth, the invention creatively adds the rosin modified resin emulsion on the outermost layer, finds that the obtained film has better appearance effect and adhesive force, greatly improves the film forming effect, and the surface of the obtained condom product is smooth and transparent, because the molecular structure of the natural rosin and the derivative thereof has a huge and nonpolar ternary phenanthrene ring structure, the invention has excellent adhesion increasing and glossiness improving effects during film forming, and particularly tests under high-speed sliding show that the condom product has excellent friction and wear resistance, and can greatly reduce the using amount of the lubricant in the existing condom.

It is worth pointing out that the condom product prepared by the invention has more excellent tensile strength and elongation at break by controlling the thickness ratio of each layer of glue film to be 1:3:1.5, and the condom product is ensured to have the characteristics of higher rebound rate and small permanent deformation.

The condom product prepared by the invention has the characteristics of no toxicity, high strength, good toughness, high elongation, good thermal conductivity, friction and abrasion resistance, easy demoulding and the like, and also has excellent physical and chemical properties and an antibacterial and virus-blocking function, and the adhesive film has higher compactness and can inhibit bacteria in contact with the adhesive film.

In the preparation method, the film forming and shaping method of the condom is not particularly limited, and the condom provided by the invention can be obtained by dipping, molding, drying, demoulding and vulcanizing according to the conventional production method of the condom. Because the condom has a three-layer structure, the condom needs to be dipped for at least three times, three layers of thin films are sequentially formed on a rod-shaped mould, and then the condom with the three-layer elastic glue film structure is formed after demoulding and vulcanization.

Further, in the preparation method, the polysiloxane diol is dimethyl siloxane with an active end group, the siloxane end group is connected with an active end hydroxyl group through a carbon chain, an ester carbon chain or an ether carbon chain, and the molecular weight of the polysiloxane diol is 1000-5000-; the fluorine-containing chain extender is dihydric alcohol or diamine with a side chain containing a fluorocarbon chain segment, and the fluorocarbon chain of the side chain of the fluorine-containing chain extender can be a perfluorocarbon chain with 4-7 carbons or a non-perfluorocarbon chain.

In the method, the diisocyanate is aliphatic and/or alicyclic diisocyanate, specifically selected from lysine-derived diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, m-xylylene isocyanate, 4-dicyclohexylmethane diisocyanate, trimethyl 1, 6-hexamethylene diisocyanate and cyclohexane dimethylene diisocyanate, and the polymer diol is at least one of polyether diol, copolyether diol, polyester diol, copolyester diol, polyether-polyester diol and polycarbonate diol, and has a number average molecular weight of 400-6000.

Further, in the step (1), the chain extender I is diamine or diol with a molecular weight of less than 300, the diol is selected from any one of ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, 1, 4-cyclohexanedimethanol, diethylene glycol or tetraethylene glycol, and the diamine is selected from any one of hydrazine, ethylenediamine, 1, 3-propylenediamine, 1, 4-butylenediamine, 1, 6-hexamethylenediamine, isophoronediamine, ethanolamine or propanolamine; the hydrophilic chain extender is one of dihydric alcohol or diamine containing hydrophilic groups.

And further, when the modified polyurethane chain extender is prepared in the step A, adding a coupling agent EDC-HCl and a dichloromethane solvent for a first reaction, and then performing a second reaction in methanol to obtain an intermediate product.

Further, the solvent used in the amino protecting group removal in the step a is ethyl acetate.

Further, when the polyisoprene emulsion is prepared, a stabilizer, water and an anti-aging agent are added into the polyisoprene rubber, and the latex is prepared according to a conventional synthetic rubber process.

Another object of the present invention is to provide a condom obtained by the above method, wherein the thickness of the condom is 20-35 μm, the length of the condom is not less than 160mm, and the inner diameter of the condom is 31-42 mm.

Compared with the prior art, the invention has the beneficial effects that:

(1) the condom product is of a multilayer sandwich type, the adhesive performance among the rubber film layers is excellent, and the condom product can be integrally formed, and due to the specific structure of demoulding of each layer, the product has excellent mechanical properties, high tensile strength, high elongation at break, good toughness, high rebound rate, smooth and transparent surface and excellent friction and wear resistance;

(2) the preparation method is simple, the preparation process is more controllable, the problems of poor processing performance, poor mixing and calendering effects and low breakage rate caused by adopting the synthetic rubber to prepare the condom are well solved, the condom product with extremely excellent performance can be obtained according to the conventional condom production method, and the product shows more excellent antibacterial property and virus barrier property.

Drawings

FIG. 1 is a mass spectrogram of the modified polyurethane chain extender obtained in the present invention;

FIG. 2 is a nuclear magnetic hydrogen spectrum of the modified polyurethane chain extender obtained in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following embodiments, and it should be noted that the following embodiments are only for explaining and illustrating the present invention and are not intended to limit the present invention. The invention is not limited to the embodiments described above, but rather, may be modified within the scope of the invention.

Example 1

Synthesizing a modified polyurethane chain extender:

performing amino protection on lysine through tert-butyloxycarbonyl, then reacting the lysine with N-N-hydroxysuccinimide in a dichloromethane solvent added with a coupling agent EDC-HCl for 5 hours at normal temperature to obtain an intermediate product I, reacting the intermediate product I with dopamine hydrochloride by using methanol as a solvent at normal temperature for 10 hours to obtain an intermediate product II, and reacting the intermediate product II with hydrochloric acid/ethyl acetate at normal temperature for 2 hours to remove an amino protecting group to obtain the modified polyurethane chain extender, wherein the reaction formula is as follows:

the mass spectrum data of the modified polyurethane chain extender obtained by testing is shown in figure 1, and the nuclear magnetic hydrogen spectrum is shown in figure 2.

Example 2

Synthesis of modified polyurethane:

(A1)) Reacting isophorone diisocyanate, polytetrahydrofuran ether glycol and hydrophilic chain extender 2, 2-dimethylolpropionic acid (DMPA) according to a molar ratio of 3:2:1 to prepare modified polyurethane, marking as PU-LDA00, and determining the molecular weight M of the modified polyurethane_n＝93215。

(II) isophorone diisocyanate, polytetrahydrofuran ether glycol and a mixed chain extender react in a molar ratio of 3:2:1, wherein the molar ratio of the mixed chain extender to the modified polyurethane chain extender is ① to the hydrophilic chain extender DMPA is 0.3:0.7, the molar ratio of the modified polyurethane chain extender to the hydrophilic chain extender DMPA is 0.5:0.5, modified polyurethanes are prepared and respectively marked as PU-LDA30 and PU-LDA50, and the molecular weights of the modified polyurethanes are respectively ① M measured_n＝108864； ②M_n＝112350。

And (3) carrying out tape casting film forming on the obtained modified polyurethane emulsion to obtain an adhesive film with the thickness of 0.1mm, carrying out water contact angle test, measuring the water contact angle by adopting a video contact tester, dropping deionized water on six different places on the surface of the film, reading the contact angle of the adhesive film after the small water drop on the surface of the adhesive film is stable, and taking an average value. The results obtained are shown in table 1.

TABLE 1

Polyurethane type	Water contact Angle (°)
		PU-LDA00	73.5±1.8
PU-LDA30	69.2±1.4
		PU-LDA50	60.6±2.0

Adhesion performance test: the modified polyurethane emulsion obtained above was used as a coating to be subjected to 180 ° peel strength test, and the coating was coated on the surface of a glass material, the thickness of the coating was 0.1mm, and the peel strength (dry state) test results are shown in table 2, which shows that the peel strength of PU-LDA50 was increased by 91.4% as compared with PU-LDA 00; the modified polyurethane emulsion is coated on the surface of a PP material, the thickness of the coating is 0.1mm, the obtained result is shown in Table 3, the peeling strength of PU-LDA50 is improved by 200% compared with that of PU-LDA00, and the obtained modified polyurethane emulsion is proved to have excellent adhesion performance.

TABLE 2

TABLE 3

Example 3

The preparation method of the multilayer condom containing the modified polyurethane raw material comprises the following steps:

(1) preparing an inner-layer adhesive film:

the emulsion is prepared by polymerizing and emulsifying the following components in percentage by mass: 19.2% of diisocyanate, 68.9% of polymer diol, 6.4% of polysiloxane diol, 1.67% of fluorine-containing chain extender, 1.13% of chain extender I and 2.7% of hydrophilic chain extender; wherein the diisocyanate is isophorone diisocyanate (IPDI); the polymer dihydric alcohol is polybutylene adipate glycol (PBA) with molecular weight of 2000; the polysiloxane diol is dimethyl siloxane with active end group, the siloxane end group is connected with the active end hydroxyl group through an ether carbon chain, and the molecular weight of the polysiloxane diol is 2500; the fluorine-containing chain extender is dihydric alcohol with a side chain containing a fluorocarbon chain segment, and a fluorocarbon chain of the side chain is a non-perfluorinated carbon chain with 5 carbons; the chain extender I is 1, 4-Butanediol (BDO); the hydrophilic chain extender is N- (2-aminoethyl) -2-aminoethane sulfonic acid sodium salt (AAS).

Preparing fluorine-containing silicon-containing aqueous polyurethane emulsion by adopting the raw materials according to a conventional prepolymer dispersion method, wherein the final solid content of the emulsion is 52%, diluting the emulsion until the solid content is 28%, soaking a rod-shaped mould into the polyurethane emulsion, taking out the rod-shaped mould, and drying the rod-shaped mould for 5-10min at 95 ℃ to form a first glue film on the rod-shaped mould;

(2) preparing an intermediate layer adhesive film:

A. emulsion polymerization is carried out on isophorone diisocyanate, polytetrahydrofuran ether glycol, a modified polyurethane chain extender and DMPA according to the molar ratio of 3:2:0.5:0.5 to prepare the modified polyurethane emulsion PU-LDA50 in the embodiment 2, wherein the solid content is 35%;

B. dissolving 30g of cis-1, 4-polyisoprene rubber (synthetic rubber Li-IR, purchased) in n-pentane, wherein the mass fraction of a glue solution after dissolution is 12%, emulsifying in a colloid mill emulsifier at a linear speed of 20m/s, selecting fatty acid soap as an emulsifier, adding a stabilizer, water and an anti-aging agent, removing an organic solvent, and pre-vulcanizing to obtain a polyisoprene emulsion with uniform granulation diameter distribution and good stability, wherein the solid content of the polyisoprene emulsion is 30%;

C. b, blending the polyurethane emulsion obtained in the step A and the polyisoprene emulsion obtained in the step B, wherein the solid content in the blending system is 31% according to the weight percentage of 20% to 80% of the polyurethane emulsion and the polyisoprene emulsion, then soaking a rod-shaped mould with a first layer into the blending emulsion, taking out the mould, and drying the mould at 95 ℃ for 5-10min to form a second adhesive film on the surface of the first adhesive film;

(3) preparing an outer-layer adhesive film:

D. 30g of maleated rosin 107^#Grinding, placing in 250ml three-neck bottle, adding 100ml gasoline 200^#Adding 17.5ml of allyl alcohol (the molar ratio of the maleic rosin to the allyl alcohol is 1:4) as a solvent, adding a proper amount of catalyst p-toluenesulfonic acid (6.5 percent of the mass of the maleic rosin) and polymerization inhibitor hydroquinone (0.5 percent of the mass of the maleic rosin) for reaction, and reacting at 110 ℃ for 5 hours to obtain maleic rosin allyl alcohol ester with an acid value of 71.75; then adding emulsifier OP-10(0.4g) and SDS (0.6g) into 30g of water, stirring to obtain pre-emulsion, heating to 60 ℃, and adding 20 weight percent (based on 100 percent of acrylic acid) of acrylic acid monomer (the total amount of acrylic acid monomer used)3% of the weight of the raw materials), 0.4g of initiator potassium persulfate and pH buffer sodium bicarbonate, heating in a water bath to 85 ℃ to perform emulsion prepolymerization for 30min, then slowly adding maleic rosin allyl alcohol ester (the mass fraction accounts for 9% of the total weight of the raw materials), the rest 80% of acrylic monomer and 0.8g of initiator potassium persulfate in a dropwise manner to prepare rosin modified resin emulsion with the solid content of 30% (refer to the literature, "synthesis of maleic rosin modified acrylic resin and performance research", Hayao, China printing and packaging research, 2010);

E. blending the polyurethane emulsion and the polyisoprene emulsion obtained in the step A, B with the rosin modified resin emulsion obtained in the step D, wherein the weight percentage of the polyurethane emulsion, the rosin modified resin emulsion and the polyisoprene emulsion in the blended emulsion is 10: 70: 20%, and the solid content in the blended emulsion is 28%, then dipping the rod-shaped mold in the blended emulsion, taking out and drying at 100 ℃ for 5-10min to form a third adhesive film;

(4) curling the glue film formed on the rod-shaped mould, further drying the four layers of films at the temperature of 120 ℃, demoulding and forming, anti-sticking treatment by using an anti-sticking material, hot air vulcanization, pinhole inspection, lubricant addition and packaging to obtain the bag.

The thickness ratio of each glue film from inside to outside in the three-layer demoulding is controlled to be 1:3:1.5 by controlling the rotating speed of the mould for dipping in each glue film.

Example 4

(1) preparing an inner-layer adhesive film:

the emulsion is prepared by polymerizing and emulsifying the following components in percentage by mass: 17.6% of diisocyanate, 61.4% of polymer diol, 9.9% of polysiloxane diol, 1.5% of fluorine-containing chain extender, 2.6% of chain extender I, 6.2% of hydrophilic chain extender, 0.5% of cross-linking agent and 0.3% of neutralizing agent;

wherein, the diisocyanate is isophorone diisocyanate (IPDI) and m-xylylene isocyanate (XDI) (the mass ratio of the isophorone diisocyanate to the m-xylylene isocyanate is 1.24: 1); the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol (PTMG with molecular weight of 3000) and polycarbonate dihydric alcohol (PCDL with molecular weight of 2000) (the mass ratio of the polytetrahydrofuran ether dihydric alcohol to the polycarbonate dihydric alcohol is 6.00: 1); the polysiloxane diol is dimethyl siloxane with active end group, the siloxane end group is connected with the active end hydroxyl group through a carbon chain, and the molecular weight of the polysiloxane diol is 5000; the fluorine-containing chain extender is N- (1, 1-dihydroxymethyl) -2- (1, 1-dihydro-perfluoropentoxy) acetamide; the chain extender I is isophorone diamine; the hydrophilic chain extender is anionic chain extender dimethylolpropionic acid (DMPA) and nonionic chain extender Ymer N-120 (the mass ratio of the two is 0.42: 1); the cross-linking agent is diethylenetriamine; the neutralizer is sodium hydroxide.

Preparing fluorine-containing silicon-containing aqueous polyurethane emulsion by adopting the raw materials according to an acetone method, wherein the final solid content of the emulsion is 25%, soaking a rod-shaped mould into the polyurethane emulsion, taking out the polyurethane emulsion, drying the polyurethane emulsion at 95 ℃ for 5-10min, and forming a first layer of glue film on the rod-shaped mould;

(2) preparing an intermediate layer adhesive film:

A. emulsion polymerization is carried out on isophorone diisocyanate, polytetrahydrofuran ether glycol, a modified polyurethane chain extender and DMPA according to the molar ratio of 3:2:0.5:0.5 to prepare polyurethane emulsion PU-LDA50 in example 2, wherein the solid content of the polyurethane emulsion is 25%;

B. dissolving 30g of cis-1, 4-polyisoprene rubber (synthetic rubber Li-IR, purchased) in n-pentane, wherein the mass fraction of a glue solution after dissolution is 15%, emulsifying in a colloid mill emulsifier at a linear speed of 25m/s, selecting fatty acid soap as an emulsifier, adding a stabilizer, water and an anti-aging agent, removing an organic solvent, and pre-vulcanizing to obtain a polyisoprene emulsion with uniform granulation diameter distribution and good stability, wherein the solid content of the polyisoprene emulsion is 30%;

C. b, blending the polyurethane emulsion obtained in the step A and the polyisoprene emulsion obtained in the step B, wherein the solid content in the blending system is 29.5% according to the weight percentage of 10% to 90% of the polyurethane emulsion and the polyisoprene emulsion, then soaking a rod-shaped mould with a first layer into the blending emulsion, taking out the mould, and drying the mould at 85 ℃ for 10min to form a second adhesive film on the surface of the first adhesive film;

(3) preparing an outer-layer adhesive film:

D. 30g of maleated rosin 107^#Grinding, placing in 250ml three-neck bottle, adding 100ml gasoline 200^#Adding 17.5ml of allyl alcohol (the molar ratio of the maleic rosin to the allyl alcohol is 1:4) as a solvent, adding a proper amount of catalyst (6.5 percent of the mass of the maleic rosin) and polymerization inhibitor (0.5 percent of the mass of the maleic rosin) to react, and reacting at 110 ℃ for 5 hours to obtain maleic rosin allyl alcohol ester with the acid value of 71.75; then adding emulsifier OP-10(0.4g), SDS (0.6g) into 30g of water and stirring to obtain pre-emulsion, heating to 60 ℃, adding 10 wt% (based on 100% of acrylic acid) of acrylic acid monomer (the total amount of acrylic acid monomer is 5% of the weight of raw materials), 0.45g of initiator potassium persulfate and pH buffer sodium bicarbonate, heating in water bath to 85 ℃ to perform emulsion prepolymerization for 30min, and then slowly dropwise adding maleated rosin propenyl alcohol ester (the mass fraction accounts for 15% of the total weight of raw materials) and the remaining 90% of acrylic acid monomer and 0.85g of initiator potassium persulfate to prepare rosin modified resin emulsion with the solid content of 20% (refer to the literature, "synthesis and performance research of maleated rosin modified acrylic resin", Yanghui, Chinese printing and packaging research, 2010);

E. blending the polyurethane emulsion and the polyisoprene emulsion obtained in the step A, B with the rosin modified resin emulsion obtained in the step D, wherein the weight percentage of the polyurethane emulsion, the rosin modified resin emulsion and the polyisoprene emulsion in the blended emulsion is 20 to 50 to 30 percent, the solid content in the blended emulsion is 30 percent, then soaking the rod-shaped mold in the blended emulsion, taking out the mold and drying the mold for 5 to 10 minutes at 90 ℃ to form a third adhesive film;

(4) curling the glue film formed on the rod-shaped mould, further drying the obtained three-layer film at the temperature of 120 ℃, demoulding and forming, anti-sticking treatment by using an anti-sticking material, hot air vulcanization, pinhole inspection, lubricant addition and packaging to obtain a package.

Example 5

(1) preparing an inner-layer adhesive film:

the emulsion is prepared by polymerizing and emulsifying the following components in percentage by mass: 37.5% of diisocyanate, 43.4% of polymer diol, 4.3% of polysiloxane diol, 4.0% of fluorine-containing chain extender, 3.8% of chain extender I, 6.7% of hydrophilic chain extender and 0.3% of cross-linking agent;

wherein the diisocyanate is isophorone diisocyanate (IPDI); the polymer dihydric alcohol is polytetrahydrofuran ether dihydric alcohol (PTMG with the molecular weight of 1000); the polysiloxane diol is dimethyl siloxane with active end group, the siloxane end group is connected with the active end hydroxyl group through an ether chain, and the molecular weight of the polysiloxane diol is 1000; the fluorine-containing chain extender is dihydric alcohol with a side chain containing a fluorocarbon chain segment, and the fluorocarbon chain of the side chain is a 7-carbon perfluorocarbon chain; the chain extender I is ethylenediamine; the hydrophilic chain extender is a cationic chain extender biquaternary ammonium diamine NG8(CN 201310337018.6); the cross-linking agent is pentaerythritol.

Preparing fluorine-containing silicon-containing aqueous polyurethane emulsion by adopting an acetone method according to the raw materials, wherein the final solid content of the emulsion is 30%, soaking a rod-shaped mould into the polyurethane emulsion, taking out the polyurethane emulsion, drying the polyurethane emulsion at 95 ℃ for 5-10min, and forming a first layer of glue film on the rod-shaped mould;

(2) preparing an intermediate layer adhesive film:

A. emulsion polymerization is carried out on isophorone diisocyanate, polytetrahydrofuran ether glycol, a modified polyurethane chain extender and DMPA according to the molar ratio of 3:2:0.5:0.5, and the polyurethane emulsion PU-LDA50 in the embodiment 2 is prepared, wherein the solid content is 30%;

B. dissolving 30g of cis-1, 4-polyisoprene rubber (synthetic rubber Li-IR, purchased) in n-pentane, wherein the mass fraction of a glue solution after dissolution is 8%, emulsifying in a colloid mill emulsifier at a linear speed of 21m/s, selecting fatty acid soap as an emulsifier, adding a stabilizer, water and an anti-aging agent, removing an organic solvent, and pre-vulcanizing to obtain a polyisoprene emulsion with uniform granulation diameter distribution and good stability, wherein the solid content of the polyisoprene emulsion is 32%;

C. b, blending the polyurethane emulsion obtained in the step A and the polyisoprene emulsion obtained in the step B, wherein the solid content in the blending system is 31.7% according to the weight percentage of 15% to 85% of the polyurethane emulsion and the polyisoprene emulsion, then soaking a rod-shaped mould with a first layer into the blending emulsion, taking out the mould, and drying the mould at 95 ℃ for 10min to form a second adhesive film on the surface of the first adhesive film;

(3) preparing an outer-layer adhesive film:

D. 30g of maleated rosin 107^#Grinding, placing in 250ml three-neck bottle, adding 100ml gasoline 200^#Adding 17.5ml of allyl alcohol (the molar ratio of the maleic rosin to the allyl alcohol is 1:4) as a solvent, adding a proper amount of a catalyst (6.5 percent of the mass of the maleic rosin) and a polymerization inhibitor (0.5 percent of the mass of the maleic rosin) to react, reacting for 5 hours at 110 ℃ to obtain maleic rosin allyl alcohol ester, then adding an emulsifier OP-10(0.4g) and SDS (0.6g) into 30g of water, stirring to obtain a pre-emulsion, heating to 60 ℃, adding 18 percent by mass (based on 100 percent of acrylic acid) of acrylic acid monomers (the total amount of the acrylic acid monomers is 4 percent of the weight of the raw materials), 0.32g of initiator potassium persulfate and pH buffer sodium bicarbonate, heating in a water bath to 85 ℃ to perform emulsion prepolymerization for 30 minutes, then slowly dropwise adding the maleic rosin allyl alcohol ester (the mass fraction accounts for 9 percent of the total weight of the raw materials), the rest 80 percent of the acrylic acid monomers and 0.78g of, the prepared rosin modified resin emulsion has a solid content of 24% (refer to the document, "synthesis of maleic rosin modified acrylic resin and performance research", shi, chinese printing and packaging research, 2010);

E. blending the polyurethane emulsion and the polyisoprene emulsion obtained in the step A, B with the rosin modified resin emulsion obtained in the step D, wherein the weight percentage of the polyurethane emulsion, the rosin modified resin emulsion and the polyisoprene emulsion in the blended emulsion is 15 to 60 to 25 percent, the solid content in the blended emulsion is 26 percent, then dipping the rod-shaped mould in the blended emulsion, taking out and drying at 95 ℃ for 5-10min to form a third glue film;

The condom prepared in the above examples 3-5 may have a sheath length of 160-200mm, an inner diameter of 31-42mm, and a thickness of 20-35 μm. Performing performance tests on the condom prepared in example 3, and selecting 100 tests, wherein no electric leakage is found in electrode tests; the water leakage test is maintained for 2-3min, and no water leakage phenomenon is found, which is higher than 1min specified by the standard; the average value of the breaking force is 60-90N, which is far higher than 10N (standard polyurethane condom standard HG/T5456-; there were no pinholes and visible defects.

The burst pressure (KPa) of the resulting condom was tested according to the methods in ISO4074 and ASTM D3492; a burst capacity (L); tensile strength (MPa), ring specimen; elongation at break (%), loop test specimen; breaking load (N), ring specimen; 300% modulus (MPa), ring specimen; the permanent deformation test is carried out according to the method GB/T1040.3-2006 for measuring the tensile property of the elastic film.

In the above embodiments 3-5, the polysiloxane diol is dimethylsiloxane with active end group, the siloxane end group is connected with the active end hydroxyl group through carbon chain, ester carbon chain or ether carbon chain, and the molecular weight is 1000-; the fluorine-containing chain extender is dihydric alcohol or diamine with a side chain containing a fluorocarbon chain segment, and a fluorocarbon chain of the side chain of the fluorine-containing chain extender can be a perfluorocarbon chain with 4-7 carbons or a non-perfluorocarbon chain; the diisocyanate is aliphatic and/or alicyclic diisocyanate, is specifically selected from lysine-derived diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, m-xylylene isocyanate, 4-dicyclohexylmethane diisocyanate, trimethyl 1, 6-hexamethylene diisocyanate and cyclohexane dimethylene diisocyanate, and the polymer diol is at least one of polyether diol, copolyether diol, polyester diol, copolyester diol, polyether-polyester diol and polycarbonate diol, and has the number average molecular weight of 400-6000; the chain extender I is diamine or diol with the molecular weight less than 300, the diol is selected from any one of ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, 1, 4-cyclohexanedimethanol, diethylene glycol or tetraethylene glycol, and the diamine is selected from any one of hydrazine, ethylenediamine, 1, 3-propylenediamine, 1, 4-butanediamine, 1, 6-hexanediamine, isophoronediamine, ethanolamine or propanolamine; the hydrophilic chain extender is one of dihydric alcohol or diamine containing hydrophilic groups; and B, when the modified polyurethane chain extender is prepared in the step A, adding a coupling agent EDC-HCl and a dichloromethane solvent to perform a first-step reaction for 5-6h, then performing a second-step reaction in methanol to obtain an intermediate product, wherein the reaction time is 10-12h, and the condition for removing the amino protecting group is that the reaction is performed in a mixed solvent of HCl/ethyl acetate at normal temperature for 2-3 h.

By replacing the corresponding raw materials and adopting the method of example 3, the multilayer condom with excellent mechanical properties can be well prepared.

The following comparative examples were designed to examine the effect of the structure of each layer of the condom and its thickness ratio on its mechanical properties and compared with common commercial condoms.

Comparative example 1

According to the method of the embodiment 3, the operation of preparing the rosin modified resin emulsion in the step (3) is removed, the outer-layer glue film is prepared by only blending the polyurethane emulsion and the polyisoprene emulsion, and the multilayer condom is prepared by the remaining steps.

Comparative example 2

According to the method of the embodiment 3, the operation of preparing the modified polyurethane emulsion in the step (2) is removed, and the polyisoprene rubber emulsion is directly adopted to prepare the middle layer for demoulding, so that the multilayer condom is obtained.

Comparative example 3

According to the method of the embodiment 3, the step of adding the polyisoprene emulsion in the step (3) is removed, only the polyurethane emulsion and the rosin modified resin emulsion are blended to prepare the outer-layer adhesive film, and the multilayer condom is prepared by the other methods without changing.

Comparative example 4

In order to examine the influence of the thickness ratio of each glue layer on the related performance of the condom, the invention designs different thickness ratios of each glue layer in the condom preparation process, and the control situation of the thickness ratio is shown in Table 4.

TABLE 4

Test example 1

The bursting property test is that 20 condoms of each model are randomly selected respectively for actual measurement and an average value is taken, and a condom bursting pressure tester PC-2010 is adopted for testing, and the results are shown in Table 5.

TABLE 5

Condom type	Blasting charge volume L	Burst pressure KPa
			EXAMPLE 3 Multi-layer condom	30	3.9
Condom made of natural latex	30	1.6
			Commercially available polyurethane condoms	12	2.5
Comparative example 1 Multi-layer mosquito repellentPregnant sleeve	25	2.8
			Comparative example 2 multilayer condom	22	2.2
Comparative example 3 multilayer condom	18	3.3

The tensile strength, elongation at break and permanent set rate of the material are shown in Table 6.

TABLE 6

The smoothness of the material surface was compared with the gloss and the wear resistance under high speed sliding:

surface observation of the condoms obtained in example 3 and comparative examples 1 to 3 revealed that the condoms of example 3 and comparative examples 2 and 3 had smoother and more transparent surfaces, whereas the condom of comparative example 1 had a slightly rougher and less transparent surface, demonstrating that the condom products with a modified rosin resin layer had higher smoothness and better gloss.

The friction and wear resistance performance of the obtained condom is tested, and the method comprises the following steps: the obtained condom is sleeved on a static and dynamic friction coefficient tester for friction test, a coupling part sample is a bearing steel ball with the diameter of 3mm, and the test conditions are that the stroke is 20mm, the room temperature is 20 ℃, the relative humidity is 45 percent, and the sliding speed is 20 cm/min. The wear life of the film is expressed in terms of the number of sliding cycles when the film is worn through, and when the coefficient of friction suddenly increases, the film is considered to have been worn through. The experimental results show that: the condoms of example 3 were not worn through after being subjected to the rubbing test for 1h, whereas the condoms of comparative examples 1-3 were worn through after being subjected to the rubbing test for 30min, 45min and 40min, respectively.

The mechanical properties of the resulting multilayered condoms at different thickness ratios were examined and the results are shown in table 7.

TABLE 7

As can be seen from the above table, the multilayered condom has the characteristics of being soft in texture but high in strength, wherein the multilayered condom obtained with the thickness ratio of 1:3:1.5 has the highest tensile strength and elongation at break, but has the characteristic of being soft.

Application example 1

(one) bacteriostatic test:

1. and (3) bacterial culture: respectively purifying three pathogenic bacteria (Diplococcus gonorrhoeae, Staphylococcus aureus, hemolytic streptococcus, purchased) on a culture medium plate until single bacterial colony appears, selecting the single bacterial colony, placing into sterile normal saline, observing under microscope, and diluting to 10%⁵CFU/ml bacterial suspension.

2. A total of 30 pieces of the commercial condom (taking the example of a commercially available polyurethane condom) products of example 3 and comparative examples 1-3 were randomly selected, 6 pieces in each group, and tightly bound to either open end of a glass cylinder having a diameter of 60mm and a height of 150mm, and used as a bottom.

3. And (3) respectively sucking 1ml of the cultured bacterial suspensions of the diplococcus gonorrhoeae, the staphylococcus aureus and the hemolytic streptococcus, respectively dripping the bacterial suspensions into the glass cylinder, uniformly coating the bacterial liquid into the glass cylinder by using an L-shaped coater, placing the glass cylinder into culture dishes containing corresponding bacterial culture media, and observing whether a bacteriostatic ring appears in each culture dish.

4. The culture conditions are as follows: 37 ℃ and 5% CO₂The incubator is used for culturing gonococcus, and the common microorganism incubator is used for culturing staphylococcus aureus and hemolytic streptococcus at 37 ℃.

5. After the same time of standing, the inhibition zone appeared in the culture dish and the glass cylinder, wherein the inhibition zone was the largest in example 3, and the results showed that: compared with other common condoms, the condom obtained by the invention has better antibacterial effect.

(II) the condom prepared in comparative example 4 with different thickness ratios was examined for the inhibition of the above bacteria by each gel layer structure, and the results of bacteriostasis are shown in Table 8.

TABLE 8

As can be seen from Table 7, the thickness ratio of each glue layer has a certain influence on the antibacterial effect of the condom, and the antibacterial effect of the condom obtained by the thickness ratio of the invention is optimal.

Application example 2

(III) testing the barrier property of the small molecules:

using water-soluble methylene blue dye as a model, molecular weight: 799 the diameter of the molecule is 2nm, the thickness is 0.5nm, the size of the dye is far smaller than the size of the virus, and the dye can be used for simulating the virus barrier property. A 5% strength methylene blue solution was prepared with deionized water. A1000 mL beaker 8cm in diameter was charged with 600mL of deionized water, 10 samples of condoms from examples 3-5, numbered 1-10, of which 1-3 was selected from the condoms from example 3, 4-6 was selected from the condoms from example 4, and 7-10 were selected from the condoms from example 5, tested for defects, and three commercial grade 0.03 natural latex condoms, numbered 11-13, were selected as controls. Under the condition of 25 ℃, 150mL of 108mol/L methylene blue solution is injected into each condom, the open end of the condom is fastened, a thin wire is hung on a bracket and is respectively suspended in the beaker filled with 600mL of deionized water, and after the condom is immersed for 0.5 hour, the deionized water in the beaker is taken out, and the absorbance value is measured by using the pure deionized water as a reference and adopting the wavelength of 420 nanometers (the precision of an ultraviolet spectrophotometer is 0.0001). (reference: JAMA, December4,1991-Vol266, No.21,2986)

The results obtained are shown in Table 9.

TABLE 9

Sample numbering	Absorbance value
		1	0.0000
2	0.0000
		3	0.0000
4	0.0000
		5	0.0000
6	0.0000
		7	0.0000
8	0.0000
		9	0.0000
10	0.0000
		11	0.0009
12	0.0012
		13	0.0010

As can be seen from Table 9, condoms obtained by the methods of examples 3-5 of the present invention have good barrier properties against viruses.

Claims

1. A preparation method of a multilayer condom containing a modified polyurethane raw material is characterized by comprising the following steps:

(1) preparing an inner-layer adhesive film:

according to the weight percentage, 15-40% of diisocyanate, 40-80% of polymer diol, 0.1-15.0% of polysiloxane diol, 0.4-5.0% of fluorine-containing chain extender, 1-5% of chain extender I and 1-10% of hydrophilic chain extender are mixed and then polymerized and emulsified to prepare fluorine-containing silicon-containing aqueous polyurethane emulsion, the fluorine-containing silicon-containing aqueous polyurethane emulsion is diluted to have the solid content of 25-30%, a rod-shaped mold is soaked in the polyurethane emulsion, the rod-shaped mold is taken out and dried at the temperature of 80-95 ℃ for 5-10min, and a first layer of adhesive film is formed on the rod-shaped mold;

(2) preparing an intermediate layer adhesive film:

A. carrying out emulsion polymerization reaction on diisocyanate, polymer dihydric alcohol, a modified polyurethane chain extender and a hydrophilic chain extender according to the molar ratio of 3:2:0.5:0.5 to prepare a polyurethane emulsion with the molecular weight range of 80000-150000 and the solid content of 25-35%, wherein the synthetic method of the modified polyurethane chain extender comprises the following steps: performing amino protection on lysine through tert-butyloxycarbonyl, then reacting the lysine with N-N-hydroxysuccinimide for 5-6h at normal temperature, then reacting with dopamine hydrochloride for 10-12h at normal temperature to obtain an intermediate product, and reacting the intermediate product with hydrochloric acid for 2-3h at normal temperature to remove amino protecting groups to obtain the modified polyurethane chain extender, wherein the structural formula of the modified polyurethane chain extender is as follows:

(3) preparing an outer-layer adhesive film:

2. The method as claimed in claim 1, wherein the polysiloxane diol is dimethylsiloxane with active terminal group, the siloxane terminal group is connected with the active terminal hydroxyl group through carbon chain, ester carbon chain or ether carbon chain, and the molecular weight is 1000-; the fluorine-containing chain extender is dihydric alcohol or diamine with a side chain containing a fluorocarbon chain segment, and the fluorocarbon chain of the side chain of the fluorine-containing chain extender can be a perfluorocarbon chain with 4-7 carbons or a non-perfluorocarbon chain.

3. The method according to claim 1, wherein the diisocyanate is an aliphatic and/or alicyclic diisocyanate, and is selected from the group consisting of lysine-derived diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, m-xylylene isocyanate, 4-dicyclohexylmethane diisocyanate, trimethyl 1, 6-hexamethylene diisocyanate, and cyclohexanedimethylene diisocyanate, and the polymer diol is at least one of polyether diol, copolyether diol, polyester diol, copolyester diol, polyether-polyester diol, and polycarbonate diol, and has a number average molecular weight of 400 to 6000.

4. The preparation method according to claim 1, wherein the chain extender I in the step (1) is diamine or diol with molecular weight less than 300, the diol is selected from any one of ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, 1, 4-cyclohexanedimethanol, diethylene glycol or tetraethylene glycol, and the diamine is selected from any one of hydrazine, ethylenediamine, 1, 3-propylenediamine, 1, 4-butanediamine, 1, 6-hexanediamine, isophoronediamine, ethanolamine or propanolamine; the hydrophilic chain extender is one of dihydric alcohol or diamine containing hydrophilic groups.

5. The preparation method of claim 1, wherein the modified polyurethane chain extender is prepared in step a by adding a coupling agent EDC-HCl and a dichloromethane solvent to perform a first reaction, and then performing a second reaction in methanol to obtain an intermediate product.

6. The process according to claim 1, wherein the solvent used for removing the amino-protecting group in step A is ethyl acetate.

7. The method according to claim 1, wherein the polyisoprene emulsion is prepared by adding a stabilizer, water and an antioxidant to the polyisoprene rubber.

8. A condom produced by the process according to any one of claims 1 to 7.

9. The condom of claim 8, wherein the condom has a thickness of 20-35 μm.

10. The condom of claim 8, wherein the condom has a length of not less than 160mm and an inner diameter of 31-42 mm.