CN111057404B

CN111057404B - Fireproof expansion film and preparation method and application thereof

Info

Publication number: CN111057404B
Application number: CN201911393929.4A
Authority: CN
Inventors: 王乾龙; 徐峰; 黄睿之; 陈淑静; 唐婕
Original assignee: Shenzhen Shen Rui Graphene Technology Co ltd; Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Shenzhen Shen Rui Graphene Technology Co ltd; Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2022-01-04
Anticipated expiration: 2039-12-30
Also published as: CN111057404A

Abstract

The invention provides a fireproof expansion film and a preparation method and application thereof. The fireproof expansion film provided by the invention can be expanded by heating when being subjected to a certain external temperature, and simultaneously generates a large amount of non-toxic and harmless non-combustible gas which can be filled around a heat source (battery), so that the risk of fire is reduced; meanwhile, the expansion of the material can also play a role in early warning.

Description

Fireproof expansion film and preparation method and application thereof

Technical Field

The invention belongs to the technical field of battery safety, and relates to a fireproof expansion film, and a preparation method and application thereof.

Background

With the background of the era of rapid economic development, technological progress is also changing day by day. Electronic products are also more and more advanced, for example, mobile phones, tablets and computers become an indispensable part of life of people at present, and the mobile phone is almost a normal state without leaving. Electronic products such as mobile phones are powered by built-in batteries, and the most dangerous parts of the mobile phones are also batteries, so that the prevention of battery ignition is the most important thing. The mobile phone is easy to have dangers such as fire or explosion caused by overhigh temperature in the using or charging process, and the problem to be solved urgently is presented. Currently, there are few effective solutions for electronic products such as mobile phones and the like in terms of ignition.

CN107146897A discloses an explosion-proof battery, which includes a battery body having a positive electrode and a negative electrode, wherein a protective sleeve is sleeved on the outer side of the battery body, the positive electrode post and the negative electrode post of the battery body penetrate through the protective sleeve and are located on the outer side of the protective sleeve, and a closed space is formed between the protective sleeve and the battery body; the protective sleeve is provided with a communication port, a cooling storage tank is arranged at the communication port, cooling fire extinguishing substances are stored in the cooling storage tank, and the air pressure in the cooling storage tank is greater than that in the closed space; the cooling storage tank is communicated with the closed space through a communication port, and a closed device is arranged at the communication port; the sealing device is composed of two sealing plates made of thermal deformation materials, the two sealing plates are contacted with each other at normal temperature to jointly seal the communication port, and when the temperature in the sealing space is not less than the deformation temperature of the two sealing plates, the two sealing plates deform and separate. The explosion-proof battery provided by the patent has no way to be applied to a small electronic device such as a mobile phone and the like.

Therefore, it is required to provide a fire-retardant film capable of effectively preventing the occurrence of a risk such as fire or explosion of a battery of an electronic product.

Disclosure of Invention

The invention aims to provide a fireproof expansion film and a preparation method and application thereof. The fireproof expansion film provided by the invention can be expanded by heating when being subjected to a certain external temperature, and simultaneously generates a large amount of non-toxic and harmless non-combustible gas which can be filled around a heat source (battery), so that the risk of fire is reduced; meanwhile, the expansion of the material can also play a role in early warning.

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

in a first aspect, the present invention provides a fire-retardant intumescent film, wherein the composition of the fire-retardant intumescent film is graphene oxide.

When the fireproof expansion film provided by the invention is heated, the oxygen-containing functional groups such as-OH, -COOH and the like carried by the graphene oxide can be subjected to oxidation reaction, so that the expansion film provided by the invention is expanded, meanwhile, the oxygen-containing functional groups are oxidized into non-combustible gases such as water vapor and carbon dioxide, and the non-combustible gases are filled around a heat source to isolate air, and further, the risk of fire or explosion of the heat source can be reduced.

Preferably, the graphene oxide has an oxygen-to-carbon molar ratio of 0.5-0.7, such as 0.52, 0.53, 0.54, 0.55, 0.58, 0.60, 0.62, 0.64, 0.65, 0.68, and the like.

In the invention, the fireproof expansion film is prepared by preferably using the graphene oxide with high oxygen content, and compared with the graphene oxide with slightly low oxygen content, when the oxygen content of the graphene oxide is higher, the graphene oxide can expand at a lower temperature and generate non-combustible gas (water vapor, carbon dioxide and the like); the lower temperature in the present invention means relatively low, probably around 150 ℃.

Preferably, the thickness of the fire-blocking intumescent film is 20-50 μm, such as 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, and the like.

In view of the fact that the fire-retardant intumescent film provided by the invention is mainly applied to the outer side of a built-in mobile phone of an electronic product, and the requirements of the electronic product are all towards light weight and thinness at present, the film thickness of the fire-retardant intumescent film is preferably below 50 μm.

In a second aspect, the present invention provides a method for preparing a fire-retardant intumescent film according to the first aspect, comprising the steps of:

and coating the graphene oxide dispersion liquid on a base film, drying, and then removing the base film to obtain the fireproof expansion film.

Preferably, the temperature of the drying is less than 100 ℃, such as 90 ℃, 80 ℃, 70 ℃, 60 ℃, 50 ℃ and the like.

And drying the graphene oxide at a lower temperature to form hydrogen bonds among oxygen-containing functional groups such as hydroxyl groups and carboxyl groups of the graphene oxide, so that the graphene oxide obtained by drying can form a film, and the fireproof expansion film is obtained.

When the fireproof expansion film is subjected to a certain temperature, hydrogen bonds are broken, oxygen-containing functional groups are oxidized to release non-combustible gas, and then the fireproof expansion film starts to expand, so that the purpose of early warning is achieved on the one hand, and the non-combustible gas released on the other hand achieves a certain fireproof effect.

Preferably, the base film is selected from a polyethylene terephthalate film (PET film), a polypropylene film (PP film) or a polyimide film (PI film).

In the present invention, the concentration of the graphene oxide in the graphene oxide dispersion liquid is 1 to 5 wt%, for example, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, etc.

Preferably, the solvent of the graphene oxide dispersion liquid is water.

The invention selects water as the dispersant, and has the advantages of environmental protection and safety.

Preferably, the viscosity of the graphene oxide dispersion liquid is 20000-26000cP, such as 21000cP, 22000cP, 23000cP, 24000cP, 25000cP and the like.

Preferably, the pH of the graphene oxide dispersion is 1.5-2, such as 1.6, 1.7, 1.8, 1.9, and the like.

Preferably, the preparation method of the graphene oxide dispersion liquid is as follows:

dispersing graphene oxide in water to obtain a graphene oxide dispersion liquid;

preferably, the dispersion is performed at a dispersion speed of 50-60rpm, such as 52rpm, 54rpm, 56rpm, 58rpm, etc., a shear speed of 4500-5500rpm, such as 4800rpm, 5000rpm, 5200rpm, for a period of 80-90min, such as 82min, 84min, 88min, etc.

In a third aspect, the invention provides the application of the fireproof expansion film according to the first aspect in the fireproof and explosion-proof of the battery;

preferably, the battery is a built-in battery of the electronic device.

The fireproof expansion film provided by the invention has the advantages that the risk of fire is well reduced, the early warning effect can be realized, and the fireproof expansion film can be used for the fireproof and explosion-proof aspects of a built-in battery of electronic equipment.

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

when the fireproof expansion film provided by the invention is heated, the oxygen-containing functional groups such as-OH, -COOH and the like carried by graphene oxide can generate oxidation reaction, so that the expansion film provided by the invention expands, meanwhile, the oxygen-containing functional groups are oxidized into non-combustible gases such as water vapor, carbon dioxide and the like, the non-combustible gases are filled around a heat source to isolate air, and further, the risk of fire or explosion of the heat source can be reduced, wherein the lowest initial expansion temperature can be below 145 ℃.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

A fireproof expansion film is prepared by the following steps:

(1) dispersing graphene oxide (Litternanotechnology Co., Ltd.) with oxygen-carbon molar ratio within 0.6 +/-0.1 in water to make the dispersion concentration of the graphene oxide be 1.5 wt%;

during dispersion, a planetary disperser was used, and the dispersion speed was 55rpm, the shear speed was 5000rpm, and the time was 85 min.

(2) The coating was performed on the PET film using a coater, and then dried in an oven at 70 ℃, and the PET film was removed to obtain a fire-retardant expanded film having a thickness of 35 μm.

Example 2

A fireproof expansion film is prepared by the following steps:

(1) dispersing graphene oxide (Litternanotechnology Co., Ltd.) with oxygen-carbon molar ratio within 0.6 +/-0.1 in water to make the dispersion concentration of the graphene oxide be 1 wt%;

during dispersion, a planetary disperser was used, and the dispersion speed was 50rpm, the shear speed was 4500rpm, and the time was 80 min.

(2) The coating was performed on the PET film using a coater, and then dried in an oven at 30 ℃, and the PET film was removed to obtain a fire-retardant expanded film having a thickness of 20 μm.

Example 3

A fireproof expansion film is prepared by the following steps:

(1) dispersing graphene oxide (Litternanotechnology Co., Ltd.) with oxygen-carbon molar ratio within 0.6 +/-0.1 in water to make the dispersion concentration of the graphene oxide be 5 wt%;

during dispersion, a planetary disperser was used, and the dispersion speed was 60rpm, the shear speed was 5500rpm, and the time was 90 min.

(2) The coating was performed on the PET film using a coater, and then dried in an oven at 50 ℃, and the PET film was removed to obtain a fire-retardant expanded film having a thickness of 50 μm.

Comparative example 1

The difference from example 1 is that this comparative example provides graphene oxide with an oxygen-to-carbon molar ratio of 0.3.

Comparative example 2

The difference from example 1 is that step (2) of this comparative example provides a drying temperature of 120 ℃.

Performance testing

The fire-retardant intumescent films provided in the examples and comparative examples were subjected to performance tests as follows:

(1) appearance: visually observing whether a film is formed or not and whether an incomplete part is broken or not;

(2) initial expansion temperature: and (3) placing the sample in a 70 ℃ oven for heat preservation for 5min, then heating at the heating rate of 1 ℃/min, and recording the initial expansion temperature.

The test results are shown in table 1:

TABLE 1

Sample (I)	Apparent morphology	Initial expansion temperature/. degree.C
			Example 1	Film formation	154
Example 2	Film formation	164
			Example 3	Film formation	145
Comparative example 1	Film formation	＞180
			Comparative example 2	Lump form, no film formation	-

The embodiment and the performance test show that the fireproof expansion film provided by the invention has good film forming property, can be expanded at a lower temperature, and the lowest initial expansion temperature can reach below 145 ℃.

As can be seen from the comparison between example 1 and comparative example 1, the oxygen-carbon ratio is preferably 0.5 or more in the present invention, and at this time, the initial expansion temperature of the fireproof expansion film is low; as is clear from the comparison between example 1 and comparative example 2, the drying temperature of the present invention needs to be 100 ℃ or lower, otherwise film formation is not easy.

The applicant states that the present invention is illustrated by the above examples of the fire-retardant intumescent film of the invention and the method of preparation and use thereof, but the invention is not limited to the above detailed methods, i.e. it is not meant that the invention must rely on the above detailed methods to be practiced. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The application of the fireproof expansion film in fireproof and explosion-proof of the battery is characterized in that the fireproof expansion film comprises the following components of graphene oxide;

the battery is a built-in battery of the electronic equipment;

the oxygen-carbon molar ratio of the graphene oxide is 0.5-0.7;

the thickness of the fireproof expansion film is 20-50 μm;

the fireproof expansion film is prepared by adopting the following method, and the method comprises the following steps:

coating the graphene oxide dispersion liquid on a base film, drying, and then removing the base film to obtain the fireproof expansion film;

the drying temperature is less than 100 ℃.

2. Use according to claim 1, characterized in that the base film is selected from polyethylene terephthalate films, polypropylene films or polyimide films.

3. The use according to claim 1, wherein the graphene oxide dispersion has a concentration of 1-5 wt%.

4. The use according to claim 1, wherein the solvent of the graphene oxide dispersion is water.

5. The use according to claim 1, wherein the viscosity of the graphene oxide dispersion is 20000-26000 cP.

6. The use according to claim 1, wherein the graphene oxide dispersion has a pH of 1.5 to 2.

7. The use according to claim 1, wherein the graphene oxide dispersion is prepared by the following method:

and dispersing graphene oxide in water to obtain the graphene oxide dispersion liquid.

8. The use as claimed in claim 7, wherein the dispersion speed is 50-60rpm, the shear speed is 4500-5500rpm, and the time is 80-90 min.