Waterborne polyurethane suitable for manufacturing ultrathin high-strength condoms as well as preparation and application of waterborne polyurethane

Abstract

The invention discloses waterborne polyurethane suitable for manufacturing ultrathin high-strength condoms as well as a preparation method and application of the waterborne polyurethane. The waterborne polyurethane is prepared from the following raw materials in parts by weight: 20 to 30 parts of diisocyanate, 100 to 200 parts of binary macromolecular alcohol, 0 to 3 parts of ternary micromolecular alcohol, 2 to 5 parts of binary micromolecular alcohol, 5 to 10 parts of hydrophilic chain extender, 50 to 100 parts of diluent, 200 to 300 parts of water, 0.5 to 2 parts of amine chain extender and 5 to 10 parts of latent curing agent. The latent curing agent is a diacetylmonoxime-terminated polyethylene glycol monomethyl ether modified hexamethylene diisocyanate tripolymer. A specific latent curing agent is introduced into a waterborne polyurethane system, and a cross-linked structure between waterborne polyurethane molecular chains is increased through a chemical combination theory, so that the mechanical property of the material is improved, the problems of poor ductility and the like of waterborne polyurethane condoms in the market are solved, and the technical defects and market requirements are filled up.

Description

Technical Field

[0001] The invention relates to the technical field of waterborne polyurethane, and in particular to a waterborne polyurethane suitable for making ultra-thin high-strength condoms, and a preparation method and application thereof. Background Art

[0002] The three most common materials for condoms on the market are: natural latex, polyurethane and polyisoprene.

[0003] Natural latex is the most common material for condoms. Its advantages are good ductility and the condoms made from it are more resistant to pulling. Its disadvantages are that some people are allergic to latex and due to material limitations, the thinnest one can only be 0.03mm.

[0004] Condoms made of polyisoprene have the advantages of high elasticity, good wear resistance and acid and alkali corrosion resistance, but the disadvantages are poor thermal conductivity, heat resistance and difficulty in machining.

[0005] Water-based polyurethane condoms are a type of polyurethane condoms. The advantage is that the thickness of the condom can be reduced to 0.01mm and it is suitable for people who are allergic to latex. The disadvantage is that the water-based polyurethane condoms currently on sale have poor ductility.

[0006] The patent specification with announcement number CN112062983B discloses an aqueous polyurethane for making condoms. The aqueous polyurethane is formed by dispersing an aqueous polyurethane polymer in water. The aqueous polyurethane polymer includes a soft segment and a hard segment. The soft segment includes a macromolecular polyol or a combination of macromolecular polyols. The hard segment includes a polyisocyanate or a combination of polyisocyanates. The macromolecular polyol is composed of polytetramolecular furan diol with a molecular weight of 500-4000, polypropylene glycol with a molecular weight of 1000-5000, and propylene oxide triol with a molecular weight of 650-6000.

[0007] The patent specification with announcement number CN117986850B discloses a degradable water-based polyurethane for condoms and a preparation method. The polyvinyl alcohol cross-linked acrylate polylactic acid particles have a three-dimensional branched molecular chain and contain olefin groups. Under the action of a photocuring agent, they undergo cross-linking and curing with the olefin groups capped at the polyurethane end, forming a stable three-dimensional chemical cross-linking network in the polyurethane matrix. When the polyurethane is subjected to external force, it can absorb and dissipate a lot of energy, have a good toughening effect, and improve the tensile properties of the polyurethane. Summary of the invention

[0008] The present invention provides an aqueous polyurethane suitable for making ultra-thin high-strength condoms, and a preparation method and application thereof, which can solve the problems raised in the above background technology that the current aqueous polyurethane condoms are ultra-thin but have poor ductility.

[0009] The present invention optimizes the structure of the waterborne polyurethane during synthesis and the formula during compounding, so that the product meets the requirement of ultra-thinness (0.01-0.03 mm) of the condom while still having high strength performance, and the hydrolysis resistance can also be further improved, thereby ensuring product performance while greatly improving user experience.

[0010] [1] A water-based polyurethane suitable for making ultra-thin high-strength condoms, the raw materials comprising, by weight: 20-30 parts of diisocyanate, 100-200 parts of dihydric macromolecular alcohol, 0-3 parts of trihydric micromolecular alcohol, preferably 1-3 parts of trihydric micromolecular alcohol, 2-5 parts of dihydric micromolecular alcohol, 5-10 parts of hydrophilic chain extender, 50-100 parts of diluent, 200-300 parts of water, 0.5-2 parts of amine chain extender, and 5-10 parts of latent curing agent;

[0011] The latent curing agent is butanone oxime-terminated polyethylene glycol monomethyl ether-modified hexamethylene diisocyanate trimer.

[0012] The present invention uses butanone oxime as a capping agent, and uses butanone oxime to react with NCO groups to cap the ends. The obtained latent curing agent can be stably present when added to the emulsion, and will not react with other raw material components. When the emulsion is heated (for example, the drying step in the condom manufacturing process, etc.) to reach the unblocking temperature, the chemical bond formed by the capping agent and the NCO group is broken, and the NCO group is released again, and further reacts and crosslinks with other raw material components, so that the final polyurethane product (for example, the condom after shaping and drying) has high strength performance.

[0013] The present invention uses butanone oxime for blocking, because its unblocking temperature is low and does not require too high a temperature for unblocking, and can be matched with conventional polyurethane condom manufacturing processes and conditions (such as the temperature of the shaping and drying process, etc.).

[0014] The latent curing agent of the present invention is modified with polyethylene glycol monomethyl ether to increase the hydrophilicity of the isocyanate trimer and make it more compatible with the polyurethane emulsion.

[0015] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the diisocyanate may include one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate (HDI), polymethylene polyphenyl diisocyanate, tetramethylxylylene diisocyanate, methylcyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate. The polymethylene polyphenyl diisocyanate is a reaction product of diisocyanate and polyether, and has NCO end groups at both ends.

[0016] The waterborne polyurethane suitable for making ultra-thin high-strength condoms, the number average molecular weight of the dihydric macromolecular alcohol can be 1000-3000 g / mol, such as 1550 g / mol.

[0017] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the dihydric macromolecular alcohol may include one or more of polytetrahydrofuran polyol, polyester polyol, polyether polyol and polycarbonate polyol.

[0018] The raw material composition of the water-based polyurethane suitable for making ultra-thin high-strength condoms preferably includes trivalent small molecule alcohols. The polyurethane product with the addition of trivalent small molecule alcohols has a higher hard segment content, a more complex structure, and improved mechanical properties and water resistance. Preferably, the trivalent small molecule alcohol includes one or more of trimethylolpropane and glycerol.

[0019] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the divalent small molecule alcohol may include one or more of 1,4-butanediol, 1,4-cyclohexanediol, ethylene glycol, propylene glycol, neopentyl glycol, ethyl butyl propanediol, cyclohexanedimethanol (specifically 1,4-cyclohexanedimethanol, etc.).

[0020] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the hydrophilic chain extender may include one or more of dimethylol propionic acid, dimethylol butyric acid, aminosulfonate aqueous solution, and small molecule sulfonate diamine.

[0021] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the diluent may include one or more of dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, butanone, and acetone.

[0022] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the amine chain extender may include one or more of ethylenediamine and hydroxyethylethylenediamine.

[0023] The water-based polyurethane suitable for making ultra-thin high-strength condoms may also include 0.02-0.06 parts of catalyst in the raw material composition in parts by weight.

[0024] The waterborne polyurethane suitable for making ultra-thin high-strength condoms, the catalyst may include one or more of dibutyltin dilaurate, organic bismuth, and triazine trimerization catalysts.

[0025] The water-based polyurethane suitable for making ultra-thin high-strength condoms may also include no more than 5 parts of a neutralizing agent in terms of weight.

[0026] The aqueous polyurethane suitable for making ultra-thin high-strength condoms, the neutralizing agent can be an organic tertiary amine, specifically triethylamine and the like.

[0027] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer can be obtained by reacting polyethylene glycol monomethyl ether with HDI trimer. Furthermore, taking into account factors such as compatibility with the emulsion, the subsequent degree of cross-linking with other raw material components, and the strength of the final polyurethane product, the mass ratio of polyethylene glycol monomethyl ether to HDI trimer is preferably 8-24:100.

[0028] The aqueous polyurethane suitable for making ultra-thin high-strength condoms may have a number average molecular weight of 500-2000 g / mol, such as 520 g / mol.

[0029] The water-based polyurethane suitable for making ultra-thin high-strength condoms, the preparation method of the latent curing agent may include:

[0030] Polyethylene glycol monomethyl ether reacts with HDI trimer to obtain polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer;

[0031] The latent curing agent is obtained by reacting butanone oxime with polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer.

[0032] The amount of butanone oxime used can be determined according to the NCO content in the polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer that has not been reacted with polyethylene glycol monomethyl ether, and it is ensured that the NCO groups in the polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer that have not been reacted with polyethylene glycol monomethyl ether are all capped by the butanone oxime reaction.

[0033] The temperature for the reaction of polyethylene glycol monomethyl ether with HDI trimer can be 80-90° C., such as 85° C.

[0034] The reaction temperature of butanone oxime and polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer can be 60-90° C., further can be 80-90° C., for example 85° C., etc. A higher reaction temperature can improve the bonding efficiency and shorten the reaction time.

[0035] [2] The method for preparing the water-based polyurethane suitable for making ultra-thin high-strength condoms according to [1] comprises the steps of:

[0036] S1, dehydrating the dihydric macromolecular alcohol, mixing it with a diisocyanate and a catalyst that can be added or not, heating it to 70-80° C. (preferably 75° C.) to obtain a first reactant;

[0037] S2, adding a dihydric small molecule alcohol and an optional trihydric small molecule alcohol to the first reactant, reacting at 70-80° C. (preferably 75° C.), cooling to 45-55° C. (preferably 50° C.) after the reaction is completed, and then adding a diluent to reduce viscosity to obtain a second reactant;

[0038] S3, add a hydrophilic chain extender and an amine chain extender to the second reactant, react at 35-45°C (preferably 40°C) for a period of time, optionally add (or not add) a neutralizer to react for a period of time, add water to disperse, add a latent curing agent to the solution after removing the diluent, and obtain an aqueous polyurethane emulsion suitable for making ultra-thin high-strength condoms.

[0039] In the method for preparing the water-based polyurethane suitable for making ultra-thin high-strength condoms, in step S1, the reaction time can be 2.5-3.5 hours, preferably 3 hours.

[0040] In the method for preparing the water-based polyurethane suitable for making ultra-thin high-strength condoms, in step S2, the reaction time can be 1.5-2.5 hours, preferably 2 hours.

[0041] In the method for preparing water-based polyurethane suitable for making ultra-thin high-strength condoms, in step S3, the reaction time at 35-45° C. (preferably 40° C.) can be 15-25 minutes, preferably 20 minutes.

[0042] In the method for preparing the water-based polyurethane suitable for making ultra-thin high-strength condoms, the reaction time for adding the neutralizer can be 5-15 minutes, preferably 10 minutes.

[0043] [3] Use of the aqueous polyurethane described in [1] or the aqueous polyurethane emulsion prepared according to the preparation method described in [2] in the production of (ultra-thin) high-strength condoms.

[0044] In some embodiments, in the application, when making (ultra-thin) high-strength condoms, the aqueous polyurethane or the aqueous polyurethane emulsion is dried at a temperature above 100° C. A higher drying temperature can improve the bond breaking and unblocking efficiency.

[0045] As a general inventive concept, [4] a (ultra-thin) high-strength condom, the raw material composition of the (ultra-thin) high-strength condom includes the aqueous polyurethane described in [1] or the aqueous polyurethane emulsion prepared by the preparation method described in [2].

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The invention introduces a specific latent curing agent into the waterborne polyurethane system, and increases the cross-linking structure between the waterborne polyurethane molecular chains through the chemical bonding theory, so that the mechanical properties of the material are improved, and the difficult problems of poor ductility of waterborne polyurethane condoms in the market are solved, thus filling the technical defects and market demands.

[0048] The present invention simplifies the condom production process by using a latent curing agent, and the latent curing agent can be directly added to the aqueous polyurethane emulsion system in advance, without the need to temporarily add the curing agent during the condom production process or when the aqueous polyurethane emulsion needs to be used. In addition, even if the conventional aqueous polyurethane emulsion temporarily adds a curing agent when it needs to be used, the resulting emulsion system has a short shelf life, usually only 3-6 hours, which has high production efficiency requirements and limits the flexibility of production. The latent curing agent of the present invention can be added when the aqueous polyurethane emulsion product is produced, and the existing process can activate it during condom production, and the shelf life is the same as the shelf life of the emulsion without the curing agent, which is at least 6 months. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0050] Embodiment 1:

[0051] 16 g of polyethylene glycol monomethyl ether with a number average molecular weight of 520 g / mol was weighed into a reactor and dehydrated at 85° C. under negative pressure for 2.5 h. After returning to normal pressure, 184 g of HDI trimer was added and the reaction was continued for 3 h. 109.63 g of butanone oxime was added and reacted for 30 min to obtain a latent curing agent.

[0052] 150 g of polytetrahydrofuran (PTMG) with a number average molecular weight of 1550 g / mol was taken into a reactor, and water was removed at 120 ° C and -0.09 MPa for 20 min. The temperature was reduced to 75 ° C and restored to normal pressure under nitrogen protection, and then 27 g of hexamethylene diisocyanate (HDI) and 0.06 g of catalyst dibutyltin dilaurate were added. After reacting for 3 hours, 1 g of trimethylolpropane (TMP) and 2.76 g of 1,4-cyclohexanedimethanol (CHDM) was reacted at 75°C for 2 hours. After the reaction was completed, the temperature was cooled to 50°C and 100g of acetone was added. After stirring at 20rpm for 20min, the temperature was cooled to 40°C, 9g of aminosulfonate A95 and 1.5g of hydroxyethylethylenediamine (AEEA) were added, and after reacting for 20min, 200g of water was added to disperse the mixture. After removing acetone, 10g of latent curing agent was added to the solution to obtain an aqueous polyurethane emulsion suitable for making ultra-thin high-strength condoms.

[0053] The prepared aqueous polyurethane emulsion was spread in a mold, and the water was dried at 100°C to form a film with a thickness of 0.1-0.2 mm to form a polyurethane resin. After measurement, the 100% tensile modulus of the prepared polyurethane resin was 2.08 MPa, the 300% tensile modulus was 3.44 MPa, and the elongation at break was 967%.

[0054] The glass mold was cleaned, the mold surface was heated to 35°C, and the above-prepared waterborne polyurethane emulsion was impregnated 3 times. After each impregnation, the mold was shaped and dried at 100°C for 4 minutes, and the mold was formed and dried at 100°C for 8 minutes after curling. Then, the mold was impregnated with a release agent and dried at 80°C. After demoulding, electrical inspection, inner packaging, and outer packaging were performed to obtain sample 1. The thickness of sample 1 was 0.021mm. The 100% tensile modulus of sample 1 was 2.14MPa, the 300% tensile modulus was 3.65MPa, the elongation at break was 926%, and the tensile strength was 31MPa. After hydrolysis in hot water at 80°C for 7 days, 80% of the tensile strength was still retained.

[0055] Comparative Example 1:

[0056] The 001 series of a certain brand on the market has a thickness of 0.02mm, a 100% tensile modulus of 1.67MPa, a 300% tensile modulus of 1.85MPa, a break elongation of 712%, and a tensile strength of 23.1MPa. It loses its basic strength after hydrolysis in hot water at 70℃ for 3 days.

[0057] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A water-based polyurethane suitable for making ultra-thin high-strength condoms, characterized in that: The raw material composition includes, by weight: 20-30 parts of diisocyanate, 100-200 parts of dihydric macromolecular alcohol, 0-3 parts of trihydric small molecule alcohol, preferably 1-3 parts, 2-5 parts of dihydric small molecule alcohol, 5-10 parts of hydrophilic chain extender, 50-100 parts of diluent, 200-300 parts of water, 0.5-2 parts of amine chain extender, and 5-10 parts of latent curing agent; The latent curing agent is butanone oxime-terminated polyethylene glycol monomethyl ether-modified hexamethylene diisocyanate trimer.

2. The aqueous polyurethane according to claim 1, characterized in that The diisocyanate includes one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl diisocyanate, tetramethylxylylene diisocyanate, methylcyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate; the polymethylene polyphenyl diisocyanate is a reaction product of a diisocyanate and a polyether, and has NCO end groups at both ends; The dihydric macromolecular alcohol has a number average molecular weight of 1000-3000 g / mol, and includes one or more of polytetrahydrofuran polyol, polyester polyol, polyether polyol, and polycarbonate polyol; The trivalent small molecule alcohol includes one or more of trimethylolpropane and glycerol; The divalent small molecule alcohol includes one or more of 1,4-butanediol, 1,4-cyclohexanediol, ethylene glycol, propylene glycol, neopentyl glycol, ethyl butyl propylene glycol, and cyclohexanedimethanol; The hydrophilic chain extender includes one or more of dimethylol propionic acid, dimethylol butyric acid, aminosulfonate aqueous solution, and small molecular sulfonate diamine; The diluent includes one or more of dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, butanone, and acetone; The amine chain extender includes one or more of ethylenediamine and hydroxyethylethylenediamine.

3. The aqueous polyurethane according to claim 1, characterized in that In parts by weight, the raw material composition also includes 0.02-0.06 parts of catalyst; The catalyst includes one or more of dibutyltin dilaurate, organic bismuth, and triazine trimerization catalysts.

4. The waterborne polyurethane according to claim 1, characterized in that The raw material composition further includes no more than 5 parts of a neutralizing agent by weight; The neutralizing agent is an organic tertiary amine, including triethylamine.

5. The waterborne polyurethane according to claim 1, characterized in that The polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer is obtained by reacting polyethylene glycol monomethyl ether with HDI trimer, wherein the mass ratio of polyethylene glycol monomethyl ether to HDI trimer is 8-24:100; The number average molecular weight of the polyethylene glycol monomethyl ether is 500-2000 g / mol; The preparation method of the latent curing agent comprises: Polyethylene glycol monomethyl ether reacts with HDI trimer to obtain polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer; The latent curing agent is obtained by reacting butanone oxime with polyethylene glycol monomethyl ether modified hexamethylene diisocyanate trimer; The temperature for the reaction of polyethylene glycol monomethyl ether with HDI trimer is 80-90°C; The temperature for the reaction of butanone oxime with polyethylene glycol monomethyl ether-modified hexamethylene diisocyanate trimer is 60 to 90°C, and further 80 to 90°C.

6. The method for preparing waterborne polyurethane according to any one of claims 1 to 5, characterized in that: Includes steps: S1, dehydrating the dihydric macromolecular alcohol, mixing it with a diisocyanate and an optionally added catalyst, heating it to 70-80° C. to react and obtain a first reactant; S2, adding a dihydric small molecule alcohol and optionally a trihydric small molecule alcohol to the first reactant, reacting at 70-80° C., cooling to 45-55° C. after the reaction, adding a diluent to reduce viscosity, and obtaining a second reactant; S3, adding a hydrophilic chain extender and an amine chain extender to the second reactant, reacting at 35-45°C for a period of time, optionally adding a neutralizer to react for a period of time, adding water to disperse, and adding a latent curing agent to the solution after removing the diluent to obtain an aqueous polyurethane emulsion suitable for making ultra-thin high-strength condoms.

7. The preparation method according to claim 6, characterized in that: In step S1, the reaction time is 2.5-3.5h; In step S2, the reaction time is 1.5-2.5h; In step S3: The reaction time at 35-45°C is 15-25 minutes; The reaction time after adding the neutralizer is 5-15 minutes.

8. Use of the aqueous polyurethane according to any one of claims 1 to 5 or the aqueous polyurethane emulsion prepared according to the preparation method according to claim 6 or 7 in the preparation of high-strength condoms.

9. The use according to claim 8, characterized in that: When making high-strength condoms, the aqueous polyurethane or the aqueous polyurethane emulsion is dried at a temperature above 100°C.

10. A high-strength condom, characterized in that: The raw material composition of the high-strength condom includes the aqueous polyurethane described in any one of claims 1 to 5 or the aqueous polyurethane emulsion prepared by the preparation method described in claim 6 or 7.