Ultrathin flexible waterborne polyurethane fingerstall and preparation method thereof

Abstract

The invention discloses an ultrathin flexible waterborne polyurethane fingerstall, and relates to the technical field of fingerstalls. The ultrathin flexible waterborne polyurethane fingerstall is prepared from the following raw materials in parts by weight: 91 to 95 parts of waterborne polyurethane latex, 2.3 to 8.5 parts of polyisoprene latex and 0.5 to 1.0 part of organic modified polysiloxane of a waterborne system. According to the technical scheme, the water-based polyurethane latex, the polyisoprene latex and the organic modified polysiloxane of the water-based system are blended according to a specific proportion, so that the material keeps the characteristics of polyurethane and also has excellent flexibility, and the prepared fingerstall is relatively thin in thickness, good in flexibility and good in fitting property.

Description

Technical Field

[0001] The present invention relates to the technical field of finger cots, in particular to an ultra-thin and flexible waterborne polyurethane finger cot and a preparation method thereof. Background Art

[0002] With people's growing knowledge of sex, attention to sexual hygiene and health has greatly increased. Finger cots have emerged as a response to this demand. These latex products, worn on the fingers, provide lubrication and protection during sexual stimulation, preventing nail scratches and bacterial invasion, allowing women to fully enjoy convenient, hygienic, and comfortable intercourse.

[0003] Finger cots are typically made of a natural latex elastic film. Existing natural latex finger cots have a thickness of 0.050-0.061mm, which ensures good elasticity and flexibility while also meeting certain tensile strength and tear resistance requirements. However, existing natural latex finger cots are too thick, which can affect sexual experience. Furthermore, existing natural latex finger cots contain additives such as vulcanizers and accelerators, which can easily cause allergic contact dermatitis in susceptible individuals.

[0004] Polyurethane finger cots are also available on the market. Although they can be made thinner and are non-toxic, odorless, and non-allergenic, they lack elasticity and flexibility compared to natural latex, feel harder when used, and don't fit as well as natural latex. Summary of the Invention

[0005] The main purpose of the present invention is to provide an ultra-thin and flexible water-based polyurethane finger sleeve and a preparation method thereof, aiming to solve the problem that the existing finger sleeves are too thick and have poor flexibility.

[0006] To achieve the above objectives, the present invention provides an ultra-thin and flexible water-based polyurethane fingertip, which is characterized by comprising the following raw materials in weight fractions: 91-95 parts of water-based polyurethane latex, 2.3-8.5 parts of polyisoprene latex, and 0.5-1.0 parts of an organically modified polysiloxane of a water-based system.

[0007] Optionally, the preparation method of the aqueous polyurethane latex comprises the following steps: S10, in the presence of a catalyst, causing a prepolymerization reaction between diisocyanate and polyether diol to generate a small molecule prepolymer; S20, adding a hydrophilic chain extender and an organic solvent to the small molecule prepolymer obtained in step S10 to cause a chain extension reaction to form a macromolecular prepolymer; S30, adding triethylamine to the macromolecular prepolymer obtained in step S20 for neutralization reaction, and adding water to the product after the neutralization reaction for emulsification to obtain a polyurethane emulsion; S40, the organic solvent in the polyurethane emulsion obtained in step S30 is removed by vacuum distillation to obtain the water-based polyurethane latex.

[0008] Optionally, in the step S10 and the step S20, the weight ratio of the polyether diol, the diisocyanate, the catalyst, the hydrophilic chain extender and the organic solvent is (190-210):(95-105):(0.4-0.6):(12-18):(90-110). In the step S30, the weight ratio of the triethylamine to the hydrophilic chain extender in the step S20 is (8.1-12.6):(12-18). In the step S30, the weight ratio of the water to the product after neutralization is (0.16-0.22):1.

[0009] Optionally, in the step S10, the diisocyanate includes hexamethylene diisocyanate, the polyether diol is selected from at least one of polytetrahydrofuran ether diol and polypropylene glycol, and the catalyst is selected from at least one of dibutyl tin dilaurate, bismuth laurate and bismuth iso-octoate. In the step S20, the hydrophilic chain extender includes 2,2-dimethylol propionic acid, and the organic solvent includes acetone.

[0010] Optionally, the weight ratio of the water-based polyurethane latex to the polyisoprene latex is 93:(4.1-6.5).

[0011] Optionally, the weight ratio of the water-based polyurethane latex to the organic modified polysiloxane of the water-based system is 93:(0.65-0.80).

[0012] Optionally, the ultra-thin flexible water-based polyurethane finger sleeve includes a sleeve body, and the sleeve body has oppositely arranged open ends and closed ends.

[0013] Optionally, the surface of the closed end is provided with a first floating point, the sleeve body connected with the closed end is provided with a threaded segment, in the direction away from the closed end, the threaded segment includes a first threaded segment, a second threaded segment and a third threaded segment arranged in sequence, and the first threaded segment and the third threaded segment are both provided with a second floating point.

[0014] The application further provides a preparation method of the ultra-thin flexible water-based polyurethane finger sleeve, which includes the following steps: Preparation of water-based polyurethane latex, and mixing of the water-based polyurethane latex, polyisoprene latex and organic modified polysiloxane of the water-based system, and fully stirring to obtain polyurethane finger sleeve mixed latex; Immersion of a mold in the polyurethane finger sleeve mixed latex, taking out of the mold and drying and demolding to obtain the ultra-thin flexible water-based polyurethane finger sleeve.

[0015] In the technical scheme of the present application, the water-based polyurethane latex is used as the base material, and the polyisoprene latex and the water-based organic modified polysiloxane are added in a specific ratio. The polyisoprene latex has excellent high elasticity and flexibility. The flexible chain segments of the polyisoprene latex can weaken the interaction force between the polyurethane molecular chains. The molecular chains of the two can interpenetrate, entangle and interact with each other, forming a special micro-phase structure, thereby effectively reducing the hardness and modulus of the polyurethane, improving the flexibility of the material, making the finger sleeve more fit the human body during use, and enhancing the comfort. The water-based organic modified polysiloxane can migrate to the surface of the polyurethane and enrich, and interact with the groups on the polyurethane molecular chain through various action mechanisms such as hydrogen bond, van der Waals force and chemical bond, thereby enhancing the interfacial bonding force between the two, and further improving the flexibility of the finger sleeve.

[0016] The technical scheme of the present application blends the water-based polyurethane latex, the polyisoprene latex and the water-based organic modified polysiloxane in a specific ratio, so that the material retains the characteristics of polyurethane while having excellent flexibility. The finger sleeve prepared has a thin thickness, good flexibility and good fit. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 An embodiment of the ultra-thin flexible water-based polyurethane finger sleeve provided by the present application is shown in the structure diagram.

[0018] Explanation of reference numerals: 1, sleeve body; 11, closed end; 111, first floating point; 12, first threaded segment; 13, second threaded segment; 14, third threaded segment; 15, thread; 16, second floating point.

[0019] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0020] The technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0021] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, motion condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications will also change accordingly.

[0022] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.

[0023] Please refer to Figure 1 The present application provides a kind of super thin flexible water-based polyurethane finger stall, including sleeve body 1, the sleeve body 1 has oppositely arranged opening end and closed end 11;The surface of the closed end 11 is provided with first floating point 111, and the sleeve body 1 connected with the closed end 11 is provided with threaded section, in the direction away from the closed end 11, the threaded section includes first threaded section 12, second threaded section 13 and third threaded section 14 arranged in sequence, and the first threaded section 12 and the third threaded section 14 are all provided with thread 15 and second floating point 16.

[0024] In the technical scheme of the present application, the structure of floating point and thread is arranged on the surface of the finger stall, which changes the physical structure of the surface of the finger stall and enriches the sense of touch.

[0025] It should be noted that the length d1 of the closed end 11 is 9~11mm, the length d2 of the first threaded section 12 is 22~26mm, the length d3 of the second threaded section 13 is 8~10mm, and the length d4 of the third threaded section 14 is 12~16mm.

[0026] Further, the super thin flexible water-based polyurethane finger stall includes the following weight fractions of raw materials: water-based polyurethane latex 91~95 parts, polyisoprene latex 2.3~8.5 parts, and organic modified polysiloxane of water-based system 0.5~1.0 parts.

[0027] By adopting the above technical solution, water-based polyurethane latex, polyisoprene latex and organically modified polysiloxane of the water-based system are blended in a specific ratio, so that the material has the characteristics of polyurethane while also having excellent flexibility and good adhesion.

[0028] It should be noted that the “polyisoprene latex” is Lin Chemical IR-550 polyisoprene emulsion, and the “water-based organically modified polysiloxane” is AFCONA-3580 water-based organically modified polysiloxane produced by EFCONA Polymer Co., Ltd.

[0029] It is understandable that if the amount of polyisoprene latex used is too small, the flexibility of the material cannot be fully improved; if the amount of polyisoprene latex used is too much, compatibility problems are likely to occur, affecting the stability of the emulsion system, resulting in reduced flexibility of the material and increased costs.

[0030] If the amount of organically modified polysiloxane used in the water-based system is too small, the flexibility of the material cannot be fully improved; if the amount of organically modified polysiloxane used in the water-based system is too large, it is easy to destroy the continuous phase structure of the emulsion system, thereby affecting the flexibility of the material.

[0031] Specifically, the preparation method of the aqueous polyurethane latex comprises the following steps: S10, in the presence of a catalyst, causing a prepolymerization reaction between diisocyanate and polyether diol to generate a small molecule prepolymer; S20, adding a hydrophilic chain extender and an organic solvent to the small molecule prepolymer obtained in step S10 to cause a chain extension reaction to form a macromolecular prepolymer; S30, adding triethylamine to the macromolecular prepolymer obtained in step S20 for neutralization reaction, and adding water to the product after the neutralization reaction for emulsification to obtain a polyurethane emulsion; S40, removing the organic solvent from the polyurethane emulsion obtained in step S30 by distillation under reduced pressure to obtain the aqueous polyurethane latex.

[0032] By adopting the above technical solution, in step S10, diisocyanate and polyether diol are added to a reactor, stirred at a stirring rate of 50-100 rpm, a catalyst is added, the reactor is sealed, and the temperature of the mixture is heated to 80±2°C. At this temperature, the stirring reaction is maintained for 2-3 hours to obtain a small molecule prepolymer.

[0033] In step S20, the temperature of the small molecule prepolymer is lowered to 40-50°C, a hydrophilic chain extender is added, and the mixture is stirred at a stirring rate of 100-150 rpm. The temperature of the material is heated to 80±2°C. At this temperature, the stirring reaction is maintained for 3-5 hours to obtain a macromolecular prepolymer. During the reaction, an appropriate amount of organic solvent is added to reduce the viscosity of the material.

[0034] In step S30, the temperature of the macromolecular prepolymer is lowered to below 60° C., triethylamine is added, and the mixture is stirred at a stirring rate of 100 to 200 rpm. A neutralization reaction is carried out for 10 to 20 minutes to obtain a semi-finished product. The semi-finished product is transferred to an emulsifier. During the transfer process, the stirring device in the emulsifier is started and stirred at a rate of 100 to 300 rpm. After the transfer of the semi-finished product is completed, water is added and stirred at a rate of 800 to 1000 rpm for 1 to 2 hours to achieve emulsification and obtain a polyurethane emulsion.

[0035] In step S40, the polyurethane emulsion is transferred to a vacuum distillation apparatus, the pressure is controlled to be -0.08~-0.09MPa (gauge pressure), and the temperature is 40~50°C, and vacuum distillation is performed to remove the organic solvent to obtain an aqueous polyurethane latex, wherein the separated organic solvent can be recovered for recycling.

[0036] It should be noted that in step S10 and step S20, the weight ratio of polyether diol, diisocyanate, catalyst, hydrophilic chain extender and organic solvent is (190-210): (95-105): (0.4-0.6): (12-18): (90-110); The weight ratio of the triethylamine in step S30 to the hydrophilic chain extender in step S20 is (8.1-12.6): (12-18); In step S30, the weight ratio of water to the product after the neutralization reaction is (0.16-0.22):1.

[0037] Specifically, in step S10, the polyether diol is selected from at least one of polytetramethylene ether glycol (PTMEG) and polypropylene glycol, and the catalyst is selected from at least one of dibutyltin dilaurate, bismuth laurate and bismuth isooctanoate; In step S20, the hydrophilic chain extender includes 2,2-dimethylolpropionic acid; and the organic solvent includes acetone.

[0038] The present invention also provides a method for preparing an ultra-thin and flexible water-based polyurethane fingertip, comprising the following steps: Prepare water-based polyurethane latex, and mix the water-based polyurethane latex, polyisoprene latex and organically modified polysiloxane of the water-based system, and stir them thoroughly to obtain a polyurethane fingertip mixed latex; The mold is immersed in the polyurethane finger sleeve mixed latex, the mold is taken out and dried, and demoulding is performed to prepare the ultra-thin and flexible water-based polyurethane finger sleeve.

[0039] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention. Preparation Example 1

[0040] A method for preparing an aqueous polyurethane latex comprises the following steps: S10. Add 200 kg of PTMEG-2000 and 100 kg of hexamethylene diisocyanate (HDI) into a reactor, stir at a rate of 100 rpm, add 0.5 kg of bismuth isooctanoate, seal the reactor, raise the temperature of the mixture in the reactor to 80°C, and at this temperature, keep stirring (100 rpm) and react for 2 hours to obtain a small molecule prepolymer.

[0041] S20, lowering the temperature of the small molecule prepolymer obtained in step S10 to 45°C, adding 15 kg of 2,2-dihydroxymethylpropionic acid, stirring at a rate of 150 rpm, raising the temperature of the material to 80°C, and at this temperature, maintaining stirring (150 rpm) for 4 hours to obtain a macromolecular prepolymer, wherein, during the reaction, 100 kg of acetone (purity 99.7 wt%) was added to reduce the viscosity of the material.

[0042] S30, lowering the temperature of the macromolecular prepolymer obtained in step S20 to 45°C, adding 10.1 kg of triethylamine, stirring at a rate of 200 rpm, and neutralizing the reaction for 20 minutes to obtain a semi-finished product; transferring the semi-finished product to an emulsifier, and during the transfer process, starting the stirring device in the emulsifier and stirring at a rate of 200 rpm. After the transfer of the semi-finished product is completed, adding soft water (temperature of 20±1°C) and stirring at a rate of 1000 rpm for 1 hour to achieve emulsification to obtain a polyurethane emulsion; wherein the mass of the added soft water is 20% of the mass of the semi-finished product.

[0043] S40. Transfer the polyurethane emulsion obtained in step S30 to a vacuum distillation apparatus, control the pressure to -0.08 MPa (gauge pressure) and the temperature to 45° C., and perform vacuum distillation to remove acetone to obtain an aqueous polyurethane latex. The separated acetone can be recovered for recycling. Examples 1 to 7

[0044] Examples 1 to 7 provide an ultra-thin, flexible, water-based polyurethane finger cot. The raw materials and their contents are shown in Table 1. The method for preparing the ultra-thin, flexible, water-based polyurethane finger cot comprises the following steps: (1) The aqueous polyurethane latex prepared in Preparation Example 1, polyisoprene latex (Lin's Chemical IR-550) and organic modified polysiloxane of the aqueous system (AFCONA-3580 of Efcona) were mixed and stirred at a rate of 100 rpm for 4 h to prepare a polyurethane fingertip mixed latex.

[0045] (2) Clean the mold, dry the cleaned mold at 85℃, take out the mold, and when the temperature of the mold is 50℃, immerse the mold vertically in the polyurethane finger cot mixed latex, stay for 5s, take out the mold, dry it at 85℃ for 3min, take out the mold, and complete the first dipping; when the temperature of the polyurethane latex layer attached to the mold is 50℃, immerse the mold vertically in the polyurethane finger cot mixed latex again, rotate the mold in the latex so that the mold is horizontal, pause horizontally for 2s, take out the mold, dry it at 85℃ for 3min, take out the mold, and complete the second dipping; when the temperature of the polyurethane latex layer on the surface of the mold is 50℃, immerse the mold vertically in the polyurethane finger cot mixed latex again, rotate the mold in the latex so that the mold is horizontal, pause horizontally for 2s, take out the mold, dry it at 85℃ for 3min, take out the mold, and complete the third dipping.

[0046] (3) After the third dipping, the mold with the polyurethane latex layer was immersed in 65°C water for 15 minutes, taken out and dried, and rolled. It was dried at 110°C for 10 minutes, immersed in 85°C ethanol (purity of 80wt%) for 50 seconds, taken out and demolded, and dried at 90°C for 15 minutes to obtain an ultra-thin and flexible water-based polyurethane fingertip.

[0047] Table 1 Raw materials and content of ultra-thin flexible water-based polyurethane finger cots (unit: kg) Water-based polyurethane latex Polyisoprene latex Organically modified polysiloxanes for water-based systems Example 1 93 6.5 0.5 Example 2 93 2.3 0.5 Example 3 93 4.1 0.5 Example 4 93 8.5 0.5 Example 5 93 6.5 0.65 Example 6 93 6.5 0.8 Example 7 93 6.5 1.0 Comparative Example 1

[0048] This comparative example is based on Example 1, with the difference that step (1) does not contain polyisoprene latex, and the rest is the same as Example 1. Comparative Example 2

[0049] This comparative example is based on Example 1, with the difference that step (1) does not contain an aqueous system of organically modified polysiloxane, and the rest remains the same as Example 1. Performance Testing

[0050] The mechanical properties of the polyurethane finger cots prepared in Examples 1 to 7 and Comparative Examples 1 to 2 were tested, and the test results are shown in Table 2 below.

[0051] Table 2 Mechanical properties test results of polyurethane finger cots Number of tests (pieces) Thickness of finger cot (μm) Average breaking force (N) Average elongation (%) Example 1 60 20~40 35.3 678 Example 2 60 20~40 32.0 676 Example 3 60 20~40 34.8 652 Example 4 60 20~40 35.1 659 Example 5 60 20~40 35.9 685 Example 6 60 20~40 36.5 689 Example 7 60 20~40 36.1 671 Comparative Example 1 60 20~40 21.7 470 Comparative Example 2 60 20~40 28.2 568 From the test results of Table 2, it can be seen that the waterborne polyurethane latex, polyisoprene latex and waterborne organic modified polysiloxane are blended according to a specific ratio, the thickness of the finger cot prepared is thinner, and the finger cot has higher tensile strength and elongation, and good flexibility.

[0052] The above merely describes the preferred embodiments of the present application, and does not limit the patent scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

Claims

1. An ultra-thin and flexible water-based polyurethane fingertip, characterized in that: The invention comprises the following raw materials in weight fractions: 91-95 parts of waterborne polyurethane latex, 2.3-8.5 parts of polyisoprene latex, and 0.5-1.0 part of organically modified polysiloxane of a waterborne system.

2. The ultra-thin and flexible water-based polyurethane finger sleeve according to claim 1, characterized in that: The preparation method of the aqueous polyurethane latex comprises the following steps: S10, in the presence of a catalyst, causing a prepolymerization reaction between diisocyanate and polyether diol to generate a small molecule prepolymer; S20, adding a hydrophilic chain extender and an organic solvent to the small molecule prepolymer obtained in step S10 to cause a chain extension reaction to form a macromolecular prepolymer; S30, adding triethylamine to the macromolecular prepolymer obtained in step S20 for neutralization reaction, and adding water to the product after the neutralization reaction for emulsification to obtain a polyurethane emulsion; S40, removing the organic solvent from the polyurethane emulsion obtained in step S30 by distillation under reduced pressure to obtain the aqueous polyurethane latex.

3. The ultra-thin and flexible water-based polyurethane finger cot according to claim 2, characterized in that: In the step S10 and the step S20, the weight ratio of the polyether diol, the diisocyanate, the catalyst, the hydrophilic chain extender and the organic solvent is (190-210): (95-105): (0.4-0.6): (12-18): (90-110); The weight ratio of the triethylamine in step S30 to the hydrophilic chain extender in step S20 is (8.1-12.6): (12-18); In step S30, the weight ratio of water to the product after the neutralization reaction is (0.16-0.22):

1.

4. The ultra-thin and flexible water-based polyurethane finger sleeve according to claim 2, characterized in that: In step S10, the polyether diol is selected from at least one of polytetramethylene ether diol and polypropylene glycol, and the catalyst is selected from at least one of dibutyltin dilaurate, bismuth laurate and bismuth isooctanoate; In step S20, the hydrophilic chain extender includes 2,2-dimethylolpropionic acid, and the organic solvent includes acetone.

5. The ultra-thin and flexible water-based polyurethane finger sleeve according to claim 1, characterized in that: The weight ratio of the aqueous polyurethane latex to the polyisoprene latex is 93:(4.1-6.5).

6. The ultra-thin and flexible water-based polyurethane finger sleeve according to claim 1, characterized in that: The weight ratio of the aqueous polyurethane latex to the organically modified polysiloxane of the aqueous system is 93:(0.65-0.80).

7. The ultra-thin and flexible water-based polyurethane finger sleeve according to claim 1, characterized in that: The ultra-thin, flexible, water-based polyurethane finger sleeve includes a sleeve body having an open end and a closed end opposite to each other; a first floating point is provided on the surface of the closed end, and a threaded segment is provided on the sleeve body connected to the closed end. In a direction away from the closed end, the threaded segment includes a first threaded segment, a second threaded segment, and a third threaded segment arranged in sequence, and a second floating point is provided on both the first threaded segment and the third threaded segment.

8. A method for preparing ultra-thin and flexible water-based polyurethane finger cots, characterized in that: The following steps are involved: Prepare water-based polyurethane latex, and mix the water-based polyurethane latex, polyisoprene latex and organically modified polysiloxane of the water-based system, and stir them thoroughly to obtain a polyurethane finger cot mixed latex; The mold is immersed in the polyurethane finger sleeve mixed latex, the mold is taken out and dried, and demoulding is performed to prepare the ultra-thin and flexible water-based polyurethane finger sleeve.

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