CN108184831B

CN108184831B - Reusable portable self-heating mosquito-repellent incense and preparation method thereof

Info

Publication number: CN108184831B
Application number: CN201711460863.7A
Authority: CN
Inventors: 咸士凯; 何佳兴; 孙飞野; 罗勇; 张利萍
Original assignee: Guangzhou Liby Enterprise Group Co Ltd
Current assignee: Guangzhou Liby Enterprise Group Co Ltd
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2020-09-08
Anticipated expiration: 2037-12-28
Also published as: CN108184831A

Abstract

The invention discloses a portable self-heating mosquito-repellent incense capable of being used repeatedly and a preparation method thereof. The portable self-heating mosquito-repellent incense comprises: a sealed container with a cover body, and a heating body, a heat conducting sheet and pyrethroid which are respectively arranged in the sealed container. The invention can initiate/stop the heating of the heating element by opening/closing the sealed container cover for many times, and the formula is optimized to ensure that the heating element can maintain high temperature quickly and stably for a long time, so that the pyrethrin on the heat conducting strip can be volatilized quickly to achieve the aim of quickly repelling and killing mosquitoes; the structure that the heating body, the heat conducting sheet and the medicament are separated up and down is adopted, so that the diffusion of the pyrethrin in the space can be promoted by fully utilizing the airflow of the rising water vapor; the invention optimizes the relative position structures of four parts and the formulas related to individual composition structures of the mosquito-repellent incense to obtain the portable mosquito-repellent incense which can freely control the opening/stopping for many times and has the effect of quickly repelling and killing mosquitoes.

Description

Reusable portable self-heating mosquito-repellent incense and preparation method thereof

Technical Field

The invention relates to a portable self-heating mosquito-repellent incense convenient to open and close, belongs to the technical field of daily chemical products, and particularly relates to a reusable portable self-heating mosquito-repellent incense and a preparation method thereof.

Background

Humans have experienced countless difficulties and challenges in long-term struggling with nature, however, until now humans have not been able to actually overcome small insects such as mosquitoes. In the face of the mosquito-related afflictions, people often use mosquito-repellent products to kill or repel mosquitoes.

At present, various mosquito repellent products are available on the market, including mosquito coil incense, electric mosquito repellent tablet, electric mosquito repellent liquid, mosquito repellent pendant and the like, and various mosquito repellent products have the characteristics of the mosquito repellent liquid and have some problems to be solved. The mosquito coil incense has good mosquito repelling and killing effect, but needs to be ignited and releases a large amount of PM2.5 harmful to human bodies; the mosquito-repellent incense liquid is convenient and durable to use, but can emit organic volatile matters harmful to human bodies; the mosquito-repellent incense piece is unstable in use effect and needs to be replaced frequently. Some ornaments for repelling mosquitoes in the market are convenient to use, but the effect is not ideal.

In addition, with the improvement of living standard of people and the increase of outdoor activities such as tourism, the convenience in use and carrying become more and more key problems considered by people. Unfortunately, the portability of current mosquito coil products in both use and carrying is unsatisfactory. The mosquito coil is inconvenient to carry, and has fire hazard when being used in the field; mosquito-repellent incense liquid and mosquito-repellent incense tablet can not be used under the condition of no electricity; the mosquito repellent ornament still has an insignificant effect because the effective components volatilize too slowly.

The main component of the mosquito-repellent incense is pyrethroid, and if the mosquito-repellent incense has excellent mosquito repelling and killing effect, enough pyrethrin must be volatilized in unit time, and the pyrethrin can be quickly diffused in space. The mosquito coil incense, the electric mosquito liquid, the electric mosquito tablet and the like in the market are heated to quickly volatilize the pyrethrin. The difference is that the mosquito coil incense is heated by burning the mosquito coil incense body, and the mosquito coil incense liquid and the mosquito coil incense pieces are both electrically heated with the volatile pyrethrin. The mosquito repellent ornament increases the volatilization of the pyrethroid as much as possible by increasing the concentration of the pyrethroid and the contact area with the air, but the volatilization rate of the pyrethroid of the mosquito repellent ornament is low because the pyrethroid has high boiling point. The heat flow and smoke generated by burning the mosquito coil incense can promote the diffusion of the pyrethrin in the space, and the volatilization of the organic steam under the heating condition of the mosquito incense liquid can also promote the diffusion of the pyrethrin in the space. The mosquito repellent ornament has no thermal convection, so that the pyrethrin is slowly volatilized, and the diffusion of the pyrethrin in the space is slow.

In order to improve the diffusion of the pyrethrin in the mosquito repellent ornaments, some mosquito repellent ornaments can be used together with the fan to obviously improve the mosquito repelling and killing effect. However, the introduction of the fan inevitably causes loss of portability, and the driving of the fan requires a large amount of electricity, and a large amount of batteries or a large-capacity charger should be carried.

In conclusion, the existing mosquito incense technology is difficult to meet the outdoor portable requirement of people, so that the research and development of a product which is convenient to use and carry, is friendly to human bodies and environment and has a good mosquito repelling and killing effect is very promising.

Disclosure of Invention

Aiming at the technical problems that organic matters or smoke dust harmful to human bodies is released in the using process of the existing mosquito repelling and killing products, and ignition is needed or the electricity consumption portability is poor, the invention aims to provide the portable self-heating mosquito incense which can be used repeatedly, and the formula is optimized to ensure that the heating body can quickly and stably maintain high temperature for a long time so as to quickly volatilize pyrethrin on the heat conducting sheet to achieve the aim of quickly repelling and killing mosquitoes; the heating element can be triggered/stopped to generate heat by opening/closing the sealed container for a plurality of times so as to control the volatilization of the pyrethrin.

In order to achieve the purpose, the invention adopts the following technical scheme.

A portable self-heating mosquito coil which can be used repeatedly comprises: a heating element, a heat conducting sheet and pyrethroid which are respectively arranged in the sealed container from bottom to top; the heat conducting sheet is in a sheet shape in the sealed container, and the lower surface of the heat conducting sheet is contacted with the heating body; the pyrethroid is directly loaded on the upper surface of the heat conducting sheet or loaded on other carriers and then placed on the heat conducting sheet; the portable self-heating mosquito-repellent incense can initiate/terminate heating of the heating body by opening/closing the sealed container cover for multiple times, thereby controlling the volatilization of the pyrethroid.

In the portable self-heating mosquito-repellent incense which can be used repeatedly,

the heating element comprises the following components in percentage by mass:

reduced iron powder: 40% -70%;

water-absorbent resin: 3% -15%;

water: 15% -35%;

carbon powder: 1% -10%;

vermiculite: 0.01% -10%;

sodium chloride: 1 to 10 percent.

The invention relates to a portable self-heating mosquito-repellent incense capable of being used repeatedly, which comprises a heating body and preferably comprises the following components in percentage by mass:

reduced iron powder: 40% -60%;

water-absorbent resin: 4% -12%;

water: 20% -30%;

carbon powder: 2% -6%;

vermiculite: 1% -3%;

sodium chloride: 2 to 5 percent.

The invention relates to a portable self-heating mosquito-repellent incense capable of being used repeatedly, wherein the sealing mode of a sealing container comprises a rotary cover, a buckle cover and a sliding cover.

The reusable portable self-heating mosquito-repellent incense is characterized in that a heat insulation layer is arranged on the inner wall or the outer wall of the sealed container, and the heat insulation layer is made of cotton, polyester cotton, glass fiber cotton or silicon dioxide aerogel.

The portable self-heating mosquito-repellent incense capable of being used repeatedly is characterized in that the temperature range of the heating body is 65-90 ℃ when the heating body works stably.

The portable self-heating mosquito-repellent incense capable of being used repeatedly is characterized in that the flaky heat conducting sheet is made of metal and has a shape including a circle, a rectangle and a triangle.

The reusable portable self-heating mosquito-repellent incense comprises one or more of ethofenprox, permethrin, deltamethrin, cypermethrin, beta-cypermethrin, alpha-cypermethrin, fenvalerate, cyhalothrin, flucythrinate, cyhalothrin, cyfluthrin, pentathrin, fenpropathrin, cyhalothrin, furamethrin, resmethrin, and allethrin.

The reusable portable self-heating mosquito-repellent incense is characterized in that the usage amount of the pyrethroid is 50-300 mg.

The invention relates to a portable self-heating mosquito-repellent incense capable of being used repeatedly, which is prepared by the following steps:

s1: putting 3% -15% of water-absorbent resin into 1% -10% of sodium chloride solution, and fully absorbing water to obtain expanded water-absorbent resin; fully and uniformly stirring the expanded water-absorbing resin, 40-70% of reduced iron powder, 1-10% of carbon powder and 0.01-10% of vermiculite to obtain a heating element;

s2: opening a cover body of the sealed container, adding a heating body into the sealed container, and then putting the heat conducting sheet loaded with the pyrethroid into the container, so that one surface of the heat conducting sheet, which is not loaded with the pyrethroid, is in contact with the heating body; the portable self-heating mosquito-repellent incense which can be used for many times is obtained by closing the sealing cover.

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

1. the mosquito-repellent incense does not need electricity, water or other materials in the using process, can automatically generate heat to promote the volatilization of the pyrethrin, and simultaneously the rising vapor flow can quickly bring out the pyrethrin, so that the rapid diffusion of the pyrethrin can achieve the effect of quickly repelling and killing mosquitoes;

2. the 'switch' can be closed or opened at any time by controlling the extrusion of the medicament and air, so that the pyrethroid is released when needed and is not wasted;

3. the appearance is regular weight is little, does not contain easily revealed material such as gas, liquid and conveniently goes out and hand-carries.

Drawings

FIG. 1 is a schematic diagram of the appearance three-dimensional structure of the portable self-heating mosquito-repellent incense of the invention; FIG. 2 is a schematic top view of the portable self-heating mosquito-repellent incense of the present invention with the cover removed; FIG. 3 is a schematic cross-sectional structure view of the portable self-heating mosquito coil of the present invention; fig. 4 is a schematic view of the structure of the heat conductive sheet of the present invention.

FIG. 5 shows the effect of the experiment of knockdown of Culex on a mosquito coil sample of a comparative example.

10: sealing the container 11: cover body 12: thermal insulation layer

20: heating element 30: heat conducting fin

40: pyrethroid compound

Detailed Description

In order to more fully understand the technical contents of the present invention, the technical solutions of the present invention will be further described and illustrated with reference to the following specific embodiments.

The features, benefits and advantages of the present invention will become apparent to those skilled in the art from a reading of the present disclosure.

As shown in fig. 1 to 4, a portable self-heating mosquito coil which can be used repeatedly, comprises: a sealed container 10 with a lid 11, and a heating element 20, a heat conductive sheet 30 and a pyrethroid 40 which are respectively provided in the sealed container 10 from the bottom up. The heat conductive sheet 30 is in the form of a sheet in the sealed container 10, and the lower surface thereof is in contact with the heating element 20. The pyrethroid 40 is directly loaded on the upper surface of the thermally conductive sheet 30, or loaded on another carrier and then placed on the thermally conductive sheet 30. The portable self-heating mosquito incense can initiate or terminate heating of the heating element 20 by opening/closing the cover body 11 of the sealed container 10 for many times, thereby controlling the volatilization of the pyrethroid 40.

According to the technical scheme, the heating element 20 can maintain high temperature quickly and stably for a long time by optimizing the formula, so that the pyrethrin on the heat conducting sheet 30 is quickly volatilized to achieve the purpose of quickly repelling and killing mosquitoes. The structure that the heating body 20, the heat conducting sheet 30 and the medicament are vertically separated is adopted, so that the spreading of the pyrethrin in the space can be promoted by fully utilizing the airflow of the rising water vapor. The aim of multiple use and ready use is achieved by controlling the opening and closing of the sealed container 10.

The invention optimizes the relative position structures of four parts and the related formula of individual composition structures of the mosquito-repellent incense to obtain the portable mosquito-repellent incense which can freely control opening/stopping and has the effect of quickly repelling and killing mosquitoes.

In the portable self-heating mosquito-repellent incense capable of being used repeatedly, the heating principle of the heating body is a primary battery reaction, and the half reactions of two poles are as follows:

negative electrode: fe-2e^-→Fe²⁺；

And (3) positive electrode: o is₂+2H₂O+4e^-→4OH^-。

The invention provides a novel portable mosquito-repellent incense which heats pyrethrin by using iron powder oxidation as a heat source. The proportion of the water-absorbing resin, the iron powder, the active carbon, the salt and the like in the formula is adjusted to stably control the temperature. The heat conducting sheet containing pyrethrin is placed in a sealed container, and the start and stop of the reaction are controlled by controlling the contact with oxygen.

s1, dissolving 50-300 mg of pyrethroid into 2-4ml of 99.7% ethanol solvent to prepare a pyrethroid solution, dropwise adding the pyrethroid solution to one side of a heat conducting strip, and heating to volatilize ethanol to obtain the heat conducting strip loaded with the pyrethroid;

s1, putting 3-15% of water-absorbent resin into 1-10% of sodium chloride solution, and fully absorbing water to obtain expanded water-absorbent resin; fully and uniformly stirring the expanded water-absorbing resin, 40-70% of reduced iron powder, 1-10% of carbon powder and 0.01-10% of vermiculite to obtain a heating element;

s3, opening a cover of the sealed container, adding a heating element into the container, and then putting the heat conducting sheet loaded with the pyrethroid into the container to enable one surface of the heat conducting sheet, which is not loaded with the pyrethroid, to be in contact with the heating element; the portable self-heating mosquito-repellent incense which can be used for many times is obtained by closing the sealing cover.

The following are the contents of examples 1 to 8, and the unit of the following parts by mass may be g or kg.

Example 1

A portable self-heating mosquito-repellent incense capable of being used repeatedly is prepared by the following steps:

1. 100mg of transfluthrin is dissolved in 2ml of 99.7% ethanol solution, the solution is dropwise added and spread on a circular aluminum heat conducting sheet with the diameter of 5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. 3 parts by mass of sodium chloride was dissolved in 35 parts by mass of water, and 8 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 3 parts by mass of carbon powder and 1 part by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a polypropylene screw cap bottle with the diameter of 8cm and the depth of 4cm, arranging a silicon dioxide aerogel heat insulation layer with the thickness of 5mm on the inner wall and the bottom of the screw cap bottle, putting the heat conducting sheet loaded with pyrethrin face up on the heating body, and screwing the screw cap tightly to obtain the reusable portable self-heating mosquito-repellent incense.

Example 2

1. 200mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a square iron heat conducting sheet with the side length of 4.5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. Dissolving 4 parts by mass of sodium chloride in 30 parts by mass of water, and adding 6 parts by mass of a water-absorbent resin into the saline solution so that the water-absorbent resin sufficiently absorbs the saline to obtain swollen water-absorbent resin particles; and fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 6 parts by mass of carbon powder and 4 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a polypropylene screw cap bottle with the diameter of 8cm and the depth of 4cm, paving a glass fiber heat insulation cotton layer with the thickness of 5mm on the inner wall and the bottom of the screw cap bottle, putting the heat conducting sheet with the pyrethroid loaded surface upwards on the heating body, and screwing the screw cap tightly to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 3

1. 200mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a square iron heat conducting sheet with the diameter of 5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. Dissolving 2 parts by mass of sodium chloride in 32 parts by mass of water, and adding 12 parts by mass of a water-absorbent resin into the saline solution so that the water-absorbent resin sufficiently absorbs the saline to obtain swollen water-absorbent resin particles; and fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 3 parts by mass of carbon powder and 1 part by mass of vermiculite to obtain the heating element.

3. Putting the heating element into a glass covered bottle with the diameter of 8cm and the depth of 4cm, paving a glass fiber heat insulation cotton layer with the thickness of 5mm on the inner wall and the bottom of the covered bottle, putting the heat conducting sheet with the pyrethroid loaded surface upwards on the heating element, and fastening the cover to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 4

1. 200mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a circular iron heat conducting sheet with the diameter of 5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. Dissolving 3 parts by mass of sodium chloride in 40 parts by mass of water, and adding 8 parts by mass of a water-absorbent resin to the saline solution so that the water-absorbent resin sufficiently absorbs the saline to obtain swollen water-absorbent resin particles; and fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 2 parts by mass of carbon powder and 2 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a glass covering bottle with the diameter of 8cm and the depth of 4cm, paving a silica aerogel layer with the thickness of 5mm on the inner wall and the bottom of the covering bottle, putting the heat conducting sheet with the pyrethroid loaded surface upwards on the heating body, and fastening the cover to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 5

1. 200mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a circular copper heat conducting sheet with the diameter of 5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. Dissolving 4 parts by mass of sodium chloride in 30 parts by mass of water, and putting 4 parts by mass of a water-absorbent resin into the saline solution so that the water-absorbent resin sufficiently absorbs saline to obtain swollen water-absorbent resin particles; and fully mixing and uniformly stirring the expanded water-absorbent resin particles, 55 parts by mass of iron powder, 5 parts by mass of carbon powder and 2 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a polypropylene slide cover box with the side length of 6cm and the depth of 4cm, paving a silica aerogel layer with the thickness of 5mm on the inner wall and the bottom of the slide cover box, putting the heat conducting sheet loaded with pyrethrin face up on the heating body, and tightly closing the slide cover box cover to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 6

1. 250mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a circular iron heat conducting sheet with the diameter of 5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. 4 parts by mass of sodium chloride was dissolved in 35 parts by mass of water, and 8 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 45 parts by mass of iron powder, 6 parts by mass of carbon powder and 2 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a polypropylene sliding cover box with the side length of 6cm and the depth of 4cm, paving a cotton layer with the thickness of 5mm on the inner wall and the bottom of the sliding cover box, putting the heat conducting sheet with the pyrethroid loaded surface facing upwards on the heating body, and tightly closing the sliding cover box to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 7

1. 100mg of transfluthrin is dissolved in 2ml of 99.7% ethanol solution, the solution is dropwise added and spread on a square aluminum oxide ceramic heat conducting sheet with the side length of 4.5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2. 4 parts by mass of sodium chloride was dissolved in 40 parts by mass of water, and 12 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 40 parts by mass of iron powder, 2 parts by mass of carbon powder and 3 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a glass rotary cover box with the diameter of 8cm and the depth of 4cm, paving a cotton layer with the thickness of 5mm on the inner wall and the bottom of the rotary cover bottle, putting the heat conducting sheet with pyrethroid loaded surface upwards on the heating body, and screwing the cover of the rotary cover bottle to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 8

2. Sodium chloride of 4 parts by mass was dissolved in 40 parts by mass of water, and 12 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 40 parts by mass of iron powder, 2 parts by mass of carbon powder and 3 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating element into a glass screw-cap bottle with the diameter of 8cm and the depth of 4cm, paving a cotton layer with the thickness of 5mm on the inner wall and the bottom of the screw-cap bottle, putting the heat conducting sheet with pyrethroid loaded surface upwards on the heating element, and screwing the cap of the screw-cap bottle to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Example 9

1. 250mg of transfluthrin is dissolved in 3ml of 99.7% ethanol solution, the solution is dropwise added and spread on a square aluminum heat conducting sheet with the side length of 4.5cm and the thickness of 1mm by a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

2.5 parts by mass of sodium chloride was dissolved in 30 parts by mass of water, and 10 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 45 parts by mass of iron powder, 5 parts by mass of carbon powder and 5 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a polypropylene screw-cap bottle with the diameter of 8cm and the depth of 4cm, paving a silica aerogel layer with the thickness of 5mm on the inner wall and the bottom of the screw-cap bottle, putting the heat conducting sheet with the pyrethroid loaded surface upwards on the heating body, and screwing the cap of the screw-cap bottle to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

The contents of comparative examples 1 to 7 are as follows.

Comparative example 1

1. dissolving 100mg transfluthrin in 2ml ethanol solution, dripping and spreading the solution on a square aluminum heat conducting sheet with side length of 4.5cm and thickness of 1mm by using a dropper, putting the heat conducting sheet into a 50 ℃ oven, baking for 1h, and removing the solvent ethanol.

2. 3 parts by mass of sodium chloride was dissolved in 60 parts by mass of water, and 10 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And (3) fully mixing and uniformly stirring the expanded water-absorbent resin particles, 20 parts by mass of iron powder, 4 parts by mass of carbon powder and 3 parts by mass of vermiculite to obtain the heating element.

Comparative example 2

1. dissolving 100mg transfluthrin in 2ml ethanol solution, dripping and spreading the solution on a square iron heat conducting sheet with side length of 4.5cm and thickness of 1mm, baking the heat conducting sheet in a 50 ℃ oven for 1h, and removing solvent ethanol.

2. 3 parts by mass of sodium chloride was dissolved in 10 parts by mass of water, and 15 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 65 parts by mass of iron powder, 4 parts by mass of carbon powder and 3 parts by mass of vermiculite to obtain the heating element.

Comparative example 3

1. dissolving 100mg transfluthrin in 2ml ethanol solution, dripping and spreading the solution on a circular aluminum heat conducting sheet with diameter of 5cm and thickness of 1mm by using a dropper, baking the heat conducting sheet in a 50 ℃ oven for 1h, and removing the solvent ethanol.

3. And putting the heat-conducting sheet with the pyrethroid loaded surface facing upwards on the heating body to obtain the portable self-heating mosquito-repellent incense.

Comparative example 4

2. 4 parts by mass of sodium chloride was dissolved in 30 parts by mass of water, and 6 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 6 parts by mass of carbon powder and 4 parts by mass of vermiculite to obtain the heating element.

3. Putting the heating body into a glass screw-cap bottle with the diameter of 8cm and the depth of 4cm, wherein the screw-cap bottle is not provided with a heat insulation layer, putting the heat conducting sheet with pyrethroid-loaded surface upwards on the heating body, and screwing the cap of the screw-cap bottle to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Comparative example 5

1. 200mg of transfluthrin is dissolved in 3ml of ethanol solution, the solution is dropwise and dropwise spread on a square aluminum oxide ceramic heat conducting sheet with the side length of 4.5cm and the thickness of 1mm by using a dropper, the heat conducting sheet is placed in a 50 ℃ oven to be baked for 1 hour, and the solvent ethanol is removed.

3. The heating element was placed in a polypropylene box with a lid having a side length of 6cm and a depth of 4cm and poor sealing properties, cotton layers having a thickness of 5mm were laid on the inner wall and bottom of the box, the heat-conducting sheet-supported pyrethrin sheet was placed on the heating element with its surface facing upward, and the box lid was closed to obtain the spontaneous heating mosquito-repellent incense sample of comparative example 5.

Comparative example 6

2. Putting the heat conducting sheet loaded with the pyrethrin into a polypropylene buckle cover sealing box with the side length of 6cm and the depth of 4cm, paving cotton layers with the thickness of 5mm on the inner wall and the bottom of the box, and tightly covering the box cover to obtain the spontaneous heating mosquito-repellent incense sample of the comparative example 6.

Comparative example 7

1. dissolving 200mg transfluthrin in 3ml ethanol solution, dripping the solution on activated carbon powder by a dropper, placing the activated carbon powder adsorbing the transfluthrin solution in a 50 ℃ oven for baking for 1h, and removing the solvent ethanol.

2. 3 parts by mass of sodium chloride was dissolved in 40 parts by mass of water, and 8 parts by mass of a water-absorbent resin was put into the saline solution, so that the water-absorbent resin sufficiently absorbed the saline to obtain swollen water-absorbent resin particles. And fully mixing and uniformly stirring the expanded water-absorbent resin particles, 50 parts by mass of iron powder, 2 parts by mass of activated carbon powder for adsorbing pyrethrin and 2 parts by mass of vermiculite to obtain the medicine-carrying heating element.

3. Putting the heating body into a glass covering bottle with the diameter of 8cm and the depth of 4cm, paving a silica aerogel layer with the thickness of 5mm on the inner wall and the bottom of the covering bottle, and fastening the cover to obtain the portable self-heating mosquito-repellent incense which can be used repeatedly.

Comparative example 8

1 piece of warming tablet with the mass of 100g and the size of 12cm multiplied by 15cm is prepared by dissolving 200mg of pyrethrin in 3ml of ethanol solution, uniformly dripping the pyrethrin solution on the warming tablet under the condition of air isolation, and drying to obtain the warming tablet loaded with the pyrethrin.

Comparative example 9

300mg of pyrethrin is dissolved in 5ml of ethanol solution, a screen cloth of the pyrethrin with the size of 20cm multiplied by 15cm is immersed in the solution, after the pyrethrin solution is completely absorbed, the screen cloth is dried in a 50 ℃ oven for 1 hour, and the screen cloth is taken out after drying, so that the mosquito repellent pendant of the comparative example 9 is obtained.

The contents of the effect test examples are as follows.

Examples of Effect test

Test experiment 1 measurement of heating parameters of mosquito-repellent incense

The experimental method comprises the following steps: samples of each example and test example were prepared, the cover of each sample was opened, the heat-generating body of each sample was allowed to come into contact with air, and a thermometer was inserted into the heat-generating body to follow the change in temperature in the test powder.

Temperature rise time: for the present invention, the temperature rise time means a time from the start of contact of the heating element with air to the time when the center temperature of the heating element reaches 60 ℃.

Maintaining time: for the purposes of the present invention, the maintenance time refers to the total time period during which the temperature is maintained above 60 degrees celsius.

Table 1 peak heating temperature, temperature rise time and hold time for samples of different example and comparative example formulations.

Sample (I)	Peak temperature (. degree. C.)	Time of temperature rise (min)	Maintenance time (h)
				Example 1	80	12	14
Example 2	82	11.5	15
				Example 3	82	12	15.5
Example 4	85	10	13.5
				Example 5	80	13	16
Example 6	87	8.5	12.5
				Example 7	85	10	12
Example 8	87	7.5	11.5
				Comparative example 1	48	0	0
Comparative example 2	88	11	3
				Comparative example 3	71	16	4.5
Comparative example 4	80	12	7
				Comparative example 5	85	10	12
Comparative example 6	25	0	0
				Comparative example 7	90	7	9.5
Comparative example 8	55	13	7.5
				Comparative example 9	25	0	0

Table 1 shows the peak heating temperature, the temperature rise time and the holding time of the samples of different formulations of examples and comparative examples. In the table, the exothermic peak temperatures of the examples were 80 ℃ or higher, and the holding times were 10 hours or longer. The higher temperature and the longer heating time can ensure that a large amount of the pyrethrin volatilizes for a long time, and the heating time of less than 13 minutes can also ensure that the pyrethrin takes effect quickly.

Comparative example 1A heat-generating body of a material contained a large amount of water and a low content of iron powder. On one hand, the heating element has low heat productivity in unit time, and on the other hand, the heating element consumes a large amount of heat when a large amount of water is heated, so that the sample of the comparative example 1 has the highest temperature of only 48 degrees and has limited contribution to promoting the volatilization of the pyrethrin. Comparative example 2 contains a large amount of iron powder and little water, and the temperature rises faster and the peak temperature is higher because of much heat generation per unit time when the lid is opened to start using, in contrast to comparative example 1, but the galvanic reaction stops when water is consumed and evaporated to the end, and thus the heat generation duration is only 3 hours. Comparative example 3 since there is no thermal insulation of the sealed box, the heat is largely dissipated, and thus the peak temperature, the heating rate and the duration of the critical parameters are inferior to those of the examples. Also, comparative example 4 has a shorter heating time because there is no heat insulating layer, resulting in more heat loss.

In conclusion, the experimental results show that the sample adopting the technical scheme of the invention has the characteristics of high peak temperature, short heating time and long duration; the heating parameter values of the comparative example samples which do not use the technical scheme are poor, and the comparative example samples are not suitable for being used as self-heating mosquito-repellent incense.

Test experiment 2: pyrethroid release rate test

The experimental method comprises the following steps: the heating mosquito-repellent incense is placed in a 1 cubic meter gas cabin with a disturbance fan, the gas cabin is sealed, the heating mosquito-repellent incense cover is opened to enable the mosquito-repellent incense to be in contact with air to generate heat and release pyrethrin into the gas cabin, and the disturbance fan is opened to ensure that gas in the cabin is uniformly mixed. And collecting gas by using a gas sampler every 1 hour, dissolving the gas into absolute ethyl alcohol, testing the concentration of the pyrethrin in the ethanol solution by adopting chromatography, and calculating to obtain the release amount of the pyrethrin in per unit time.

TABLE 2 pyrethroid release of mosquito coil samples of different examples and comparative examples

Table 2 shows the hourly and 8 hr total pyrethroid release for several of the examples and comparative examples. As can be seen from the table, the pyrethroid release amount per hour of each example is about 1mg, and the minimum release amount is above 0.6mg, which shows that the continuous release performance of each example sample is better. On the one hand, the heating temperature of the samples in all the embodiments is over 80 ℃, so that a large amount of volatilization of the pyrethrin can be promoted; on the other hand, a large amount of water vapor in the heating body can volatilize at a higher temperature, and the rising air flow can promote the pyrethrin to quickly separate from the heat conducting sheet and volatilize into the air.

While the samples of comparative example 1 and comparative example 2 had poor sustained release of pyrethrin due to low heating temperature or poor continuity of heating of the heating element. Comparative example 6 because there is no heating element, the high boiling point pyrethrin is difficult to volatilize, the amount of pyrethrin volatilized in the whole test process can be ignored. It was experimentally determined that comparative example 7 did not release the pyrethroid throughout the process, mainly because the pyrethroid had completely hydrolyzed during the heating in comparative example 7. In comparative example 7, there was no heat conductive sheet, and pyrethrin was directly supported on the heating element. The positive pole is alkaline in the exothermic reaction process of the heating element, and the pyrethroid can be hydrolyzed completely under the high-temperature and strong-alkaline conditions, so that no pyrethroid is released in the whole process. The sample of comparative example 8 had only 0.59mg of pyrethroid released throughout the test. This is because the maximum exothermic temperature of comparative example 8 is only 55 deg.c, which does not promote the volatilization of pyrethrin well; in addition, the lower temperature and the thicker packing material are not favorable for the volatilization of the water vapor, and the rising water vapor flow promoting the volatilization of the pyrethrin can not be formed compared with the examples. Example 9 is a mosquito repellent hanger used at normal temperature, and although the contact area with air is large enough to promote the volatilization of pyrethrin, the volatilization of pyrethrin is slow at normal temperature, so the volatilization amount of pyrethrin per hour is below 0.1mg, and a good mosquito repellent effect is difficult to achieve.

From the above experimental results, it can be found that the example sample adopting the technical scheme of the invention has good pyrethroid sustained release performance, while the comparative example pyrethroid not adopting the technical scheme of the invention has poor pyrethroid release performance and can not meet the practical requirement.

Test experiment 3: multiple use performance testing

The experimental method is as follows:

the heating mosquito-repellent incense is placed in a 1 cubic meter gas cabin with a disturbance fan, the gas cabin is sealed, the heating mosquito-repellent incense cover is opened to enable the mosquito-repellent incense to be in contact with air to generate heat and release pyrethrin into the gas cabin, and the disturbance fan is opened to ensure that gas in the cabin is uniformly mixed. And 2h later, collecting gas by using a gas sampler, dissolving the gas into absolute ethyl alcohol, testing the concentration of the pyrethrin in the ethanol solution by adopting chromatography, and calculating to obtain the release amount of the pyrethrin in per unit time. And opening the gas cabin after sampling, taking out the heating mosquito-repellent incense sample and closing the sealing box cover. And cleaning the gas cabin by using a water gun and then drying the gas cabin by using hot air. Opening the mosquito-repellent incense cover after 3h, putting the mosquito-repellent incense into the gas chamber, collecting gas in the chamber by using a gas sampler after 2h, and measuring the concentration of the pyrethroid in the chamber by adopting the method.

The above experiment was repeated 4 times to determine the amount of released pyrethrin per 2h of mosquito coil application.

TABLE 3 Release amount of pyrethrin during multiple uses of mosquito incense of each example and comparative example

Table 3 shows the amount of chrysanthemum ester released by the mosquito-repellent incense used for a plurality of times in each example and comparative example. It can be seen from the table that even after three uses, the mosquito incense samples of the embodiments still release enough amount of pyrethrin for the fourth use and the amount of the pyrethrin released by the same mosquito incense is not different each time the mosquito incense is used. This demonstrates that the samples of each example can be reused multiple times and are stable in performance. The values of the amount of multi-use pyrethroid released are also shown in the table for some of the comparative examples. The sample of comparative example 3 has a large difference in the amount of pyrethroid released between the first use and the second use, and the amount of pyrethroid released is reduced from 0.5mg to 0.04 mg. This phenomenon occurred mainly because the sample of comparative example 3, which did not have the sealed case, caused the heat-generating body to continuously release heat even when not in use, and when the heat-generating body was continuously heated for 5 hours and the temperature was reduced to 60 degrees centigrade or less at the time of the second use, the amount of release of pyrethrin was greatly reduced. Therefore, the heat-generating body was exposed to the air for 8 hours when the use was started for the third time, the heat-generating body did not generate heat, and the amount of volatilization of pyrethrin was almost 0.

From the test results of comparative example 3, it was found that a sealing container capable of isolating air is essential in order that the self-heating mosquito-repellent incense can be stably used for a plurality of times. Similarly, the heat-generating body continuously releases heat when being in contact with air when not in use due to the unsealed container, so that the release amount of the pyrethrin of the mosquito-repellent incense sample of the comparative example 5 is greatly changed when being used for multiple times. The example 8 sample continued to generate heat without interruption when not in use due to the absence of a sealed container, resulting in its fourth use in which the iron had completely oxidized and no longer heated.

As can be seen from the test procedures and results of comparative examples 3, 5 and 8, the absence of a container completely isolating air does not ensure the spontaneous heating mosquito coil to start and stop releasing pyrethrin at any time, and thus the aim of repeated effective use cannot be achieved. And the device can not be carried or has great potential safety hazard in the carrying process because the device can not be stopped after being opened. Comparative example 9 relies on the volatile pyrethrin at normal temperature, and the pyrethrin is released more stably and continuously during the whole experiment. However, similar to the results of test experiment 2, the amount of the pyrethroid released in comparative example 9 was so low that the object of rapidly and effectively killing mosquitoes could not be achieved.

From a comparison of the data results of the above examples and comparative examples we can conclude that:

each embodiment manufactured by adopting the technical scheme of the invention can be effectively used for many times; the aim of multiple effective use can not be achieved by adopting each proportion without adopting the technical scheme of the invention.

Test experiment 4: culex knockdown experiment

The experimental method is as follows:

the sealing covers of the self-heating mosquito-repellent incense of each example and comparative example were opened and left in the air for 30 min. At 36m ³50 fatigued culex mosquitoes are put into the glass room, after the culex mosquitoes to be tested move normally, mosquito-repellent incense is put on the middle ground of the glass room, the whole glass room is closed, timing is started, the number of the knocked down culex mosquitoes is checked and recorded every 5min, and KT-50 time and KT-95 time are calculated according to the recorded result.

TABLE 4 KT-50 and KT-95 of different examples of culex knockdown experiments

Sample (I)	KT-50(min)	KT-95(min)
			Example 1	11.315	22.16
Example 3	7.655	15.135
			Example 5	8.44	16.055
Example 7	10.265	19.885

As can be seen in Table 4, the KT-50 values of the mosquito incense samples of the examples are within 12min, which shows that the examples can play a remarkable role quickly. This is because the samples of the examples have a reasonable structure and a sufficient calorific value, and are capable of releasing a sufficient amount of pyrethrin in a short period of time.

The comparative examples shown in fig. 5 each hit mosquitoes less than 10 within 60min, because a sufficient amount of pyrethrin was not released per unit time. Comparative example 1 a sufficient amount of pyrethrin could not be volatilized due to the low temperature of the heating element; comparative example 7 pyrethroid is directly contacted with a heating body to cause hydrolysis of pyrethroid during heat release, thereby disabling release of pyrethroid; comparative example 8 the sample was cooler and did not form a large updraft of water vapour, so the amount of pyrethroid released was low and diffusion of pyrethroid in the glasshouse was slow; comparative example 9 has no heat-generating body, and the amount of released pyrethrin is small even if the volatilization area is large.

From the above experimental results, it can be seen that the example using the technical solution of the present invention can rapidly knock down culex for experiments, whereas the comparative example not using the technical solution of the present invention has poor performance in knocking down culex.

The foregoing is a preferred embodiment of the present invention, and is not intended to limit the invention in any way, so that the invention is not to be limited by the scope of the appended claims, and any simple modification, equivalent change or modification made to the foregoing embodiment according to the technical spirit of the present invention is still within the scope of the invention.

Claims

1. A portable self-heating mosquito-repellent incense that can repetitiously use, its characterized in that includes: a heating element, a heat conducting sheet and pyrethroid which are respectively arranged in the sealed container from bottom to top; the heat conducting sheet is in a sheet shape in the sealed container, and the lower surface of the heat conducting sheet is contacted with the heating body; the pyrethroid is directly loaded on the heat conducting sheet or loaded on other carriers and then placed on the heat conducting sheet; the portable self-heating mosquito-repellent incense can initiate/terminate heating of the heating element by opening/closing the sealed container cover for multiple times, so that the pyrethroid volatilization is controlled;

the heating element is powder or block-shaped, and comprises the following components in percentage by mass:

reduced iron powder: 40% -70%;

water-absorbent resin: 3% -15%;

water: 15% -35%;

carbon powder: 1% -10%;

vermiculite: 0.01% -10%;

sodium chloride: 1 to 10 percent.

2. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the sealing mode between the sealed container and the cover body comprises a screw cap, a buckle cap and a sliding cap.

3. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the inner wall or the outer wall of the sealed container is provided with a heat insulation layer, and the heat insulation layer is made of cotton, polyester cotton, glass fiber cotton or silicon dioxide aerogel pads.

4. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the preferable composition and mass percentage of the heating element are as follows:

reduced iron powder: 40% -60%;

water-absorbent resin: 4% -12%;

water: 20% -30%;

carbon powder: 2% -6%;

vermiculite: 1% -3%;

sodium chloride: 2 to 5 percent.

5. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the flaky heat conducting fin is made of metal.

6. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the pyrethroid comprises one or more of ethofenprox, permethrin, deltamethrin, cypermethrin, fenvalerate, cyhalofop-butyl valerate, cyfluthrin, fluthrin, cyhalofop-butyl valerate, cyhalothrin, cyfluthrin, pentathrin, fenpropathrin, cyhalothrin, furamethrin, resmethrin and allethrin.

7. The portable self-heating mosquito coil capable of being used repeatedly according to claim 1, characterized in that: the usage amount of the pyrethroid is 50mg-300 mg.

8. The reusable portable self-heating mosquito coil according to any one of claims 1-7, wherein: the preparation method comprises the following steps: