Preparation method of mosquito repelling coating with fast-curing polyurethane as carrier and paper diaper

Abstract

The invention relates to a preparation method of a mosquito-repellent coating with fast-curing polyurethane as a carrier, which comprises the following steps: S1, adding each component in a formula of a component A into a stirring kettle, and uniformly mixing to obtain a first component of the coating; s2, uniformly mixing the component B to obtain a second component of the coating; and S3, coating the carrier with the first component of the coating, spraying and covering the coating film of the component A with the second component of the coating, and standing to form the mosquito-repellent coating. The component A comprises a mosquito repellent, a volatilization assisting solvent, long-chain polyol, a tackifier, a cross-linking agent, a foaming agent and a catalyst; and the component B is polyisocyanate and / or a prepolymer of the polyisocyanate. The preparation method is used for preparing the mosquito-repelling coating capable of being rapidly cured on the carrier, the coating is of a gap structure, the mosquito-repelling coating does not volatilize in the low-temperature storage process, the mosquito-repelling coating volatilizes after being in contact with a human body and heated, and the mosquito-repelling coating can be applied to disposable products such as paper diapers.

Description

Technical Field

[0001] The invention belongs to the field of chemistry and relates to mosquito repellent materials, and in particular to a method for preparing a mosquito repellent coating with fast-curing polyurethane as a carrier and a diaper. Background Art

[0002] Mosquitoes can transmit epidemic encephalitis B, malaria, dengue fever, filariasis, Zika virus disease and many other diseases. The number of human deaths caused directly or indirectly by mosquitoes each year exceeds that of all other animals. The harm to infants and young children is much greater than that to adults. Mosquitoes often carry some pathogens, such as Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, etc. After being bitten by them, not only will the skin become red, swollen and itchy, but it is also more likely to spread diseases. Therefore, mosquito repellent is urgent for infants and young children.

[0003] The main ingredients of mosquito repellent products on the market are mainly divided into the following categories: ① Picaridin, ② DEET, ③ DEET. According to the national standard GB24330-2009 "General Technical Conditions for Safety of Household Hygiene Insecticides", mosquito repellent products are regulated, but there is no specific division for the age of infants and young children. According to the regulations of the American Academy of Pediatrics, children two months old and above can use mosquito repellent products with DEET as the main ingredient. Compared with DEET, DEET is safer, and there are no clear restrictions on its use in various countries.

[0004] Once the existing mosquito repellent products are exposed or sprayed on clothing, they will evaporate quickly, which is not conducive to storage and use in combination with clothing. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for preparing a mosquito repellent coating with a fast-curing polyurethane as a carrier and a diaper. The coating prepared by the present invention has certain mechanical properties and excellent mosquito repellent effect.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing a mosquito repellent coating with a fast-curing polyurethane as a carrier comprises the following steps:

[0008] S1. Add the ingredients of component A into a stirred tank, heat to 40-60°C, stir for 2-6 hours, and mix well to obtain the first component of the coating;

[0009] S2: Mix component B evenly to obtain the second component of the coating;

[0010] S3: applying the first component of the coating to the carrier, spraying the second component of the coating to cover the coating film of component A, and letting it stand to form a mosquito repellent coating.

[0011] The component A comprises 10-50% of mosquito repellent, 20-60% of volatile solvent, 25-50% of long-chain polyol, 0.5-15% of tackifier, 0.1-5% of cross-linking agent, 0.1-5% of foaming agent and 0.1-20% of catalyst; the component B is polyisocyanate and / or prepolymer of polyisocyanate, and the above proportions are all weight ratios, and the mass ratio of the first component of the coating to the second component of the coating is 1.5 to 3:1.

[0012] Preferably, the volatile solvent in component A is a mixture of any one or more of isohexylene glycol, ethyl acetate, butyl acetate, eucalyptus essential oil, peppermint essential oil, lavender essential oil and geranium essential oil.

[0013] Preferably, the mosquito repellent in the A component is one of the original mosquito repellents such as DEET, picaridin, and dimethoate.

[0014] Preferably, the long-chain polyol in the component A is any one of polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene adipate glycol, polyethylene adipate glycol monopropylene glycol ester glycol, polyethylene adipate glycol ether, and polyethylene adipate glycol.

[0015] Preferably, the viscosity enhancer in the component A is any one of polyvinyl pyrrolidone, polyvinyl butyral and polyvinyl formal.

[0016] Preferably, the crosslinking agent in the component A is any one of diethylenetriamine, diethyltoluenediamine, dimethylthiotoluenediamine, diethanolamine and triethanolamine, or a combination of any two thereof.

[0017] Preferably, the catalyst in component A is any one of triethylenediamine, triethylamine, dibutyltin dilaurate, bis(dimethylaminoethyl)ether, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylalkylenediamine, and N,N'-diethylpiperazine.

[0018] Preferably, the B component is any one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, or a prepolymer or polymer of any one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate.

[0019] A mosquito repellent coating with fast-curing polyurethane as a carrier is obtained by using any one of the above preparation methods.

[0020] A paper diaper comprises a carrier, wherein the carrier is provided with the mosquito repellent coating.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The mosquito repellent component in the present invention does not participate in the chemical reaction and will not affect the subsequent effect of the mosquito repellent component.

[0023] 2. The viscosity of component A in the present invention is reasonably designed, which is easy for industrial film coating and not easy to flow. The viscosity of component B is moderate, which is easy for industrial production spraying.

[0024] 3. The solidified material formed by the present invention has a fast solidification speed and is easy to industrialize.

[0025] 4. The present invention uses a non-toxic volatile solvent such as isohexylene glycol, which is not only easy to adjust the viscosity, but also easy for the subsequent mosquito repellent to evaporate at an appropriate speed, so that the mosquito repellent effect reaches an ideal level.

[0026] 5. The selected tackifier has good compatibility with the volatile solvent isohexanediol, but slightly weaker compatibility with the long-chain polyols and crosslinking agents in component A, so that the macromolecular tackifier forms a cage effect on isohexanediol due to solvation; at the same time, the selected component B isocyanate has significantly better compatibility with long-chain polyols and crosslinking agents than caged isohexanediol, which makes the diffusion rate and reaction rate of the isocyanate in component B to the long-chain polyols and crosslinking agents in component A much higher than that to the volatile solvent isohexanediol. Isohexanediol basically does not participate in the reaction during the mixed crosslinking and foaming process of components A and B, thereby maximizing its volatile effect on the mosquito repellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is the weight loss curve obtained by testing the volatilization process of Example 1 of the present invention;

[0029] Figure 2 This is the weight loss curve obtained by testing the volatilization process of Example 2 of the present invention;

[0030] Figure 3 This is the weight loss curve obtained by testing the volatilization process of Example 3 of the present invention;

[0031] Figure 4 This is the weight loss curve obtained by testing the volatilization process of Example 4 of the present invention;

[0032] Figure 5 This is an enlarged photograph of the coating void structure obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] A method for preparing a mosquito repellent coating with a fast-curing polyurethane as a carrier includes three steps: preparation of component A, preparation of component B, and fast curing of the two components. The formula examples of components A and B of the specific implementation method are shown in Table 1.

[0035] Table 1 Formulation Example of Component A and Component B

[0036]

[0037]

[0038] Example 1: A fast-curing mosquito repellent coating with polyurethane as carrier and its preparation method:

[0039] Step S1: Prepare the raw materials according to the formula 1 in Table 1, weigh 30 kg of isohexanediol as a volatile solvent, 20 kg of mosquito repellent and 1 kg of polyvinyl butyral (PVB) as a tackifier, add them into a container equipped with a thermostat and a stirring blade, and stir for 30 minutes at 40°C to fully dissolve them. Then add 25 kg of polyether 330 and 10 kg of polyether 3628 as long-chain polyols, 1 kg of water as a foaming agent, 12 kg of triethylenediamine as a catalyst, and 1 kg of diethanolamine as a cross-linking agent, continue stirring for 120 minutes, and discharge the material as the first component of the coating;

[0040] Polyether 330 and Polyether 3628 are common long-chain polyol mixtures available on the market, and the main components are polyether polyol copolymers.

[0041] Step S2: Weigh 50 kg of polymethylene polyphenyl isocyanate as the second coating component.

[0042] Step S3: uniformly apply the first component of the coating obtained in step 1 onto a plastic film or a non-woven fabric carrier, and then spray a layer of the second component of the coating on the coating layer of the first component of the coating, wherein the weight ratio of the first component of the coating to the second component of the coating is 1:0.5, and the two components are mixed to complete the curing and foaming process, and the curing time is 30-60 seconds. The obtained coating has certain mechanical properties and mosquito repellent effects.

[0043] The curing and foaming process is that the foaming agent water in component A reacts with component B to generate carbamic acid. Component B can be any one of toluene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl isocyanate, as long as it contains an NCO group.

[0044] The reaction equation is:

[0045] R-NCO+H2O→R-NHCOOH→R-NH2+CO2↑

[0046] Amino acid is unstable and decomposes into carbon dioxide gas and amines. The long-chain polyol can be any one of polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene adipate glycol, polyethylene adipate glycol monopropylene glycol ester glycol, polyethylene adipate glycol ether, and polyethylene adipate glycol. The cross-linking agent can be diethylenetriamine, diethyltoluenediamine, dimethylthiotoluenediamine, diethanolamine, and triethanolamine.

[0047] The curing and foaming process is that the long-chain polyol and cross-linking agent in component A react with component B to form a three-dimensional porous structure object through cross-linking, such as Figure 5 As shown, the mosquito repellent and the volatile solvent do not participate in the cross-linking process and fill in the pores. The role of the catalyst is to accelerate the cross-linking reaction speed. The role of the thickener is to increase the viscosity of the A component mixture, so that the coating process is stable, flow is prevented, and the quantitative control of the coating amount is facilitated.

[0048] The catalyst can be any one of triethylenediamine, triethylamine, dibutyltin dilaurate, bis(dimethylaminoethyl)ether, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylalkylenediamine, and N,N'-diethylpiperazine.

[0049] The role of the catalyst is to speed up the reaction rate. The initial research and development purpose of the coating of the present invention is to be applied to diapers. The diapers are packaged and shipped with the cured coating. In the process of mass production of diapers in modern industry, the curing time of the coating after spraying is required to be controlled within 30 seconds. After adding the catalyst, the curing speed of the A and B coatings after spraying can be controlled within 7-20 seconds.

[0050] Embodiment 2:

[0051] Step S1: Prepare the raw materials according to formula 2 in Table 1, weigh 28 kg of isohexylene glycol and 2 kg of butyl acetate as volatile solvent, 20 kg of DEET and 1 kg of polyvinyl formal as tackifier, add them into a container equipped with a thermostat and stirring blades, and stir for 30 minutes at 40°C to fully dissolve them. Then add 25 kg of polyether PPG2000 and 15 kg of polyether 3628 as long-chain polyols, 1 kg of water as a foaming agent, 9 kg of bis(dimethylaminoethyl)ether as a catalyst, and 1 kg of diethyltoluenediamine as a crosslinking agent, continue stirring for 120 minutes, and discharge the material as the first component of the coating;

[0052] Polyether PPG2000 is a common long-chain polyol mixture on the market, the main component of which is polypropylene glycol.

[0053] Step S2: Weigh 50 kg of liquefied diphenylmethane diisocyanate as the second coating component.

[0054] The remaining steps are similar to those in Example 1.

[0055] Embodiment 3:

[0056] Step S1: Prepare the raw materials according to formula 3 in Table 1, weigh 28 kg of isohexylene glycol and 1 kg of lavender essential oil as volatile solvents, 20 kg of mosquito repellent and 1 kg of polyvinyl pyrrolidone as tackifiers, add them into a container equipped with a thermostat and stirring blades, and stir for 30 minutes at 45°C to fully dissolve them. Then add 25 kg of polyether PPG2000 and 15 kg of polyether 3628 as long-chain polyols, 1.5 kg of water as a foaming agent, 11 kg of triethylenediamine as a catalyst, and 1 kg of triethanolamine as a cross-linking agent, continue stirring for 120 minutes, and discharge the material as the first component of the coating;

[0057] Step S2: Weigh 50 kg of polymethylene polyphenyl isocyanate as the second coating component.

[0058] The remaining steps are similar to those in Example 1.

[0059] Embodiment 4:

[0060] Step S1: Prepare the raw materials according to formula 4 in Table 1, weigh 25 kg of isohexylene glycol, 3 kg of butyl acetate and 2 kg of lavender essential oil as volatile solvents, 19 kg of picaridin and 2 kg of polyvinyl formal as tackifiers, add them into a container equipped with a thermostat and stirring blades, and stir for 30 minutes at 40°C to fully dissolve them. Then add 28 kg of polyether PPG2000 and 12 kg of polyether 3628 as long-chain polyols, 1 kg of water as a foaming agent, 7 kg of bis-dimethylaminoethyl ether as a catalyst, and 1 kg of diethanolamine as a cross-linking agent, continue stirring for 120 minutes, and discharge the material as the first component of the coating;

[0061] Picaridin, also known as icaridin, was invented by the German company Saltigo. It is a broad-spectrum repellent with good mosquito repellent effect and long protection time. It is considered to be safer and less toxic than DEET, has no skin irritation, and has a higher overall level.

[0062] Step S2: weigh 50 kg of toluene diisocyanate as the second component of the coating.

[0063] The remaining steps are similar to those in Example 1.

[0064] Example 5: A diaper is produced using a coated carrier obtained by any one of the methods of Examples 1 to 4, wherein the carrier is usually a non-woven fabric.

[0065] like Figures 1 to 4 The weight loss curves obtained in Examples 1 to 4 are given, with the horizontal axis being time (hours) and the vertical axis being the residual mass percentage, that is, the percentage of the residual mass to the original mass as time increases. In an open environment, a carrier sample coated with a mosquito repellent coating is placed on a sample stage of a thermal gravimetric analyzer (TGA) at a constant temperature to measure the weight loss curve of the sample to simulate the volatilization rate of the mosquito repellent coating at various temperatures.

[0066] The content of volatile mosquito repellent and volatile solvent in the carrier submitted for inspection is about 33%. The volatilization rate is measured in an open environment to simulate the volatilization process of the mosquito repellent components after the diaper is opened.

[0067] from Figures 1 to 4 It can be seen that at 25 degrees Celsius, the volatilization time of the volatile components exceeds 72 hours, and the volatilization speed is accelerated at 35 degrees Celsius and 45 degrees Celsius. The time from the volatile components to the vertical axis no longer decreasing, that is, 66%, is 60-70 hours and 30-35 hours respectively. This feature can be applied to diapers. Before wearing, diapers are generally placed in a room with a low temperature. After wearing, the baby may go out in a hot outdoor environment, and the baby's body temperature will also cause the temperature of the diaper to increase. At this time, the volatilization speed of the volatile components is accelerated, which is conducive to repelling mosquitoes.

[0068] At the same time, the above test curves are carried out in an open environment. Diapers are sealed during transportation and when not in use. The evaporation rate is slower in a sealed state. Even if the whole package is opened, babies generally change more than 6 diapers every 24 hours. As long as the number of diapers in the whole package is properly controlled, it can be ensured that all diapers are used within the non-evaporation time.

[0069] from Figures 1 to 4 It can also be seen that Figure 1 , Figure 2 The evaporation rate in Figure 3 and Figure 4 This is because the mass ratio of the volatile solvent to the mosquito repellent in Example 1 and Example 2 is about 1.5:1, while the mass ratio of the volatile solvent to the mosquito repellent in Example 3 and Example 4 is about 2.2. It can be seen that with the increase of the volatile solvent, the volatile rate will also increase. The increase in the volatile rate means a shortening of the storage and use period, but the mosquito repellent effect within the use period can be improved. According to the specific needs of diaper products, the volatile rate can be adjusted by adjusting the mass ratio of the volatile solvent to the mosquito repellent.

[0070] Since the coating formed by the present application has a cubic pore structure, the volatile substances and mosquito repellent substances are all inside the pores. Even if a small amount is exposed on the surface, it will evaporate rapidly during the production, transportation and use. When used as a diaper coating, it does not directly contact the baby's skin. The three-dimensional pore structure-shaped objects that directly contact the baby's skin are long-chain polyols and isocyanate reactants, which have no irritating effect on biological tissues.

[0071] The applicant commissioned China Inspection and Quarantine (Tianjin) Testing Co., Ltd. to conduct an irritation test report on diapers with layers. The test report issued (test report number CAST-03-2024-0698-01) showed that during multiple complete skin irritation tests: the average score of the test sample diapers on multiple complete skin irritations of rabbits was 0.00, and the irritation intensity was judged to be non-irritating.

[0072] The foregoing describes various preferred embodiments of the present invention. Unless the preferred implementation modes in various preferred embodiments are obviously self-contradictory or based on a certain preferred implementation mode, various preferred implementation modes can be arbitrarily superimposed and used in combination. The embodiments and specific parameters in the embodiments are only for clearly describing the invention verification process of the inventor, and are not used to limit the patent protection scope of the present invention. The patent protection scope of the present invention shall still be based on its claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a mosquito repellent coating with a fast-curing polyurethane as a carrier, characterized in that: The following steps are involved: S1. Add the ingredients of component A into a stirred tank, heat to 40-60°C, stir for 2-6 hours, and mix well to obtain the first component of the coating; S2: Mix component B evenly to obtain the second component of the coating; S3: applying the first component of the coating to the carrier, spraying the second component of the coating to cover the coating film of component A, and letting it stand to form a mosquito repellent coating. The component A comprises 10-50% of mosquito repellent, 20-60% of volatile solvent, 25-50% of long-chain polyol, 0.5-15% of tackifier, 0.1-5% of cross-linking agent, 0.1-5% of foaming agent and 0.1-20% of catalyst; the component B is polyisocyanate and / or prepolymer of polyisocyanate, and the above proportions are all weight ratios, and the mass ratio of the first component of the coating to the second component of the coating is 1.5 to 3:

1.

2. The preparation method according to claim 1, characterized in that The volatile solvent in component A is a mixture of any one or more of isohexylene glycol, ethyl acetate, butyl acetate, eucalyptus essential oil, peppermint essential oil, lavender essential oil and geranium essential oil.

3. The preparation method according to claim 1, characterized in that: The mosquito repellent in the A component is one of the original mosquito repellents such as DEET, picaridin, and dimethoate.

4. The preparation method according to claim 1, characterized in that: The long-chain polyol in the component A is any one of polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene adipate glycol, polyethylene adipate glycol monopropylene glycol ester glycol, polyethylene adipate glycol ether, and polyethylene adipate glycol.

5. The preparation method according to claim 1, characterized in that: The tackifier in the component A is any one of polyvinyl pyrrolidone, polyvinyl butyral and polyvinyl formal.

6. The preparation method according to claim 1, characterized in that: The crosslinking agent in the component A is any one of diethylenetriamine, diethyltoluenediamine, dimethylthiotoluenediamine, diethanolamine and triethanolamine, or a combination of any two of them.

7. The preparation method according to claim 1, characterized in that: The catalyst in the A component is any one of triethylenediamine, triethylamine, dibutyltin dilaurate, bis(dimethylaminoethyl)ether, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylalkylenediamine, and N,N'-diethylpiperazine.

8. The preparation method according to claim 1, characterized in that: The B component is any one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, or a prepolymer or polymer of any one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate.

9. A mosquito repellent coating with a fast-curing polyurethane as a carrier, characterized in that: Obtained by the method according to any one of claims 1 to 8.

10. A diaper comprising a carrier, characterized in that: The carrier has the mosquito repellent coating as claimed in claim 9.

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