阅读说明：本技术 阻燃涂料、石墨聚苯阻燃颗粒、石墨聚苯阻燃板及制备方法 (Flame-retardant coating, graphite polyphenyl flame-retardant particles, graphite polyphenyl flame-retardant plate and preparation method ) 是由 甘世鹏 李迎旭 查纯喜 李金钟 于 2021-07-29 设计创作，主要内容包括：本发明提供了一种阻燃涂料、石墨聚苯阻燃颗粒、石墨聚苯阻燃板及制备方法,涉及涂料技术领域,所述阻燃涂料包括按质量份数计的如下原料：A阶酚醛树脂25-45份,石墨10-20份,无卤阻燃剂25-40份、成膜物质8-15份和水5-10份。本发明提供的阻燃涂料引入A阶酚醛树脂、石墨无卤阻燃剂和成膜物质相互配合,不仅降低了体系的导热系数,而且提高了体系的可膨胀性,增强了粘结强度,同时其包覆于石墨聚苯颗粒表面后,能够在石墨聚苯颗粒周围形成隔绝空气的隔离罩,遇热部分组分蒸发并带走大量热,剩下组分炭化结晶形成骨架,解决石墨聚苯颗粒遇火燃烧的缺陷,增强其阻燃性能。(The invention provides a flame-retardant coating, graphite polyphenyl flame-retardant particles, a graphite polyphenyl flame-retardant plate and a preparation method thereof, and relates to the technical field of coatings, wherein the flame-retardant coating comprises the following raw materials in parts by weight: 25-45 parts of A-stage phenolic resin, 10-20 parts of graphite, 25-40 parts of halogen-free flame retardant, 8-15 parts of film forming material and 5-10 parts of water. The flame-retardant coating provided by the invention introduces the A-stage phenolic resin, the graphite halogen-free flame retardant and the film-forming substance to be matched with each other, so that the heat conductivity coefficient of a system is reduced, the expansibility of the system is improved, the bonding strength is enhanced, meanwhile, after the flame-retardant coating is coated on the surface of the graphite polyphenyl granules, an isolation cover for isolating air can be formed around the graphite polyphenyl granules, components are evaporated and take away a large amount of heat when being heated, the rest components are carbonized and crystallized to form a framework, the defect that the graphite polyphenyl granules burn when encountering fire is overcome, and the flame retardant property of the flame-retardant coating is enhanced.)

1. The flame-retardant coating is characterized by comprising the following raw materials in parts by weight:

25-45 parts of A-stage phenolic resin, 10-20 parts of graphite, 25-40 parts of halogen-free flame retardant, 8-15 parts of film forming material and 5-10 parts of water.

2. The flame-retardant coating according to claim 1, which is characterized by comprising the following raw materials in parts by mass: 25-35 parts of A-stage phenolic resin, 10-20 parts of graphite, 30-35 parts of halogen-free flame retardant, 8-15 parts of film forming material and 8-10 parts of water.

3. The flame retardant coating of claim 1 further comprising an adjuvant comprising at least one of a thickener, lubricant or dispersant;

preferably, the thickening agent is 0.1-1 part by mass;

preferably, the lubricant is 0.5-1 part by mass;

preferably, the thickener comprises at least one of carboxymethyl cellulose, hydroxyethyl cellulose, or bentonite;

preferably, the lubricant comprises a silicone oil;

preferably, the dispersant comprises sodium polyacrylate.

4. The flame retardant coating of claim 1, wherein the halogen-free flame retardant comprises at least one of aluminum hydroxide, magnesium hydroxide, antimony trioxide, or melamine cyanurate urea;

preferably, the particle size of the halogen-free flame retardant is 0.5-100 μm.

5. The flame retardant coating of claim 1, wherein the film forming material comprises at least one of a silicone-acrylic emulsion, a styrene-acrylic emulsion, or a vinyl-acrylic emulsion;

preferably, the particle size of the graphite is less than or equal to 80 meshes;

further preferably, the particle size of the graphite is 7500-8000 meshes.

6. A fire retardant particle of graphite-polyphenyl comprising graphite-polyphenyl particles and the fire retardant coating of any one of claims 1 to 5, wherein the fire retardant coating coats the surface of the graphite-polyphenyl particles.

7. The graphite-polyphenyl flame retardant particles of claim 6, wherein the mass ratio of the graphite-polyphenyl particles to the flame retardant coating is 1: (1.5-2);

preferably, the particle size of the graphite polyphenyl particles is 4-5 mm.

8. The method for preparing the graphite-polyphenyl flame-retardant particles according to claim 6 or 7, characterized by comprising the following steps:

pre-foaming the graphite polyphenyl master batch to obtain graphite polyphenyl particles, uniformly mixing the graphite polyphenyl particles with the flame retardant coating to coat the surface of the graphite polyphenyl particles with the flame retardant coating, and drying to obtain the graphite polyphenyl flame retardant particles;

preferably, the expansion ratio in the pre-foaming treatment is 40 to 50 times.

9. A graphite-polyphenyl flame-retardant sheet, which is characterized by being mainly prepared from the graphite-polyphenyl flame-retardant particles of claim 6 or 7, wherein the density of the graphite-polyphenyl flame-retardant sheet is 35-50kg/m³。

10. The method for preparing a graphite-polyphenyl flame-retardant plate according to claim 9, characterized by comprising the following steps:

after the graphite polyphenyl flame-retardant particles are formed by steam, sequentially cooling and aging to obtain a graphite polyphenyl flame-retardant plate;

preferably, the pressure of steam forming is 0.04-0.06MPa, and the temperature is 95-110 ℃;

preferably, the cooling treatment is carried out by adopting a vacuum cooling mode;

preferably, the temperature of the aging treatment is 60-70 ℃ and the time is 1-2 d.

Technical Field

The invention relates to the technical field of coatings, in particular to a flame-retardant coating, graphite polyphenyl flame-retardant particles, a graphite polyphenyl flame-retardant plate and a preparation method thereof.

Background

The graphite polystyrene board is a graphite modified polystyrene foam board, referred to as SEPS board for short, and is a building heat-insulating material with the highest utilization rate in the market at present. It is a black solid with a micro-closed pore structure, which is formed by heating expandable polystyrene particles containing a volatile liquid foaming agent in a mold after heating and pre-foaming. The graphite polystyrene board can effectively protect the wall, has high strength, long durability, good heat insulation performance, low manufacturing cost, simple construction and convenient maintenance, so the graphite polystyrene board is widely applied to a wall heat insulation system as a heat insulation material with good performance. However, the traditional graphite polystyrene board belongs to thermoplastic B1 grade material, and is melted, shrunk and flowed immediately when meeting fire, the fire spreading speed is high, and the fire passing area is large.

At present, the graphite polyphenyl plate with the halogen flame retardant is commonly used for flame retardant modification, but the halogen flame retardant can generate toxic and harmful gases in the combustion process and cause harm to human bodies and the environment.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

One of the purposes of the invention is to provide an environment-friendly flame retardant coating for improving the flame retardant property of a graphite polystyrene board, so as to solve the technical problem that the existing halogen-containing flame retardant is adopted to carry out flame retardant modification on the graphite polystyrene board and cause harm to human bodies and the environment.

The flame-retardant coating provided by the invention comprises the following raw materials in parts by weight: 25-45 parts of A-stage phenolic resin, 10-20 parts of graphite, 25-40 parts of halogen-free flame retardant, 8-15 parts of film forming material and 5-10 parts of water.

Further, the flame-retardant coating provided by the invention comprises the following raw materials in parts by weight: 25-35 parts of A-stage phenolic resin, 10-20 parts of graphite, 30-35 parts of halogen-free flame retardant, 8-15 parts of film forming material and 8-10 parts of water.

Further, the flame-retardant coating also comprises an auxiliary agent, wherein the auxiliary agent comprises at least one of a thickening agent, a lubricating agent or a dispersing agent;

preferably, the thickening agent is 0.1-1 part by mass;

preferably, the lubricant is 0.5-1 part by mass;

preferably, the thickener comprises at least one of carboxymethyl cellulose, hydroxyethyl cellulose or bentonite;

preferably, the lubricant comprises a silicone oil;

preferably, the dispersant comprises sodium polyacrylate.

Further, the halogen-free flame retardant comprises at least one of aluminum hydroxide, magnesium hydroxide, antimony trioxide or melamine urea cyanide;

preferably, the particle size of the halogen-free flame retardant is 0.5-100 μm.

Further, the film forming substance comprises at least one of silicone-acrylic emulsion, pure acrylic emulsion, styrene-acrylic emulsion or vinyl acetate-acrylic emulsion;

preferably, the particle size of the graphite is less than or equal to 80 meshes;

preferably, the particle size of the graphite is 7500-8000 meshes.

The second purpose of the invention is to provide a graphite polyphenyl flame-retardant particle, which comprises graphite polyphenyl particles and the flame-retardant coating provided by the first purpose of the invention, wherein the flame-retardant coating is coated on the surfaces of the graphite polyphenyl particles.

Further, the mass ratio of the graphite polyphenyl particles to the flame-retardant coating is 1: (1.5-2);

preferably, the particle size of the graphite polyphenyl particles is 4-5 mm.

The invention also aims to provide a preparation method of the graphite polyphenyl flame-retardant particle, which comprises the following steps:

pre-foaming the graphite polyphenyl master batch to obtain graphite polyphenyl particles, uniformly mixing the graphite polyphenyl particles with the flame retardant coating to coat the surface of the graphite polyphenyl particles with the flame retardant coating, and drying to obtain the graphite polyphenyl flame retardant particles;

preferably, the expansion ratio in the pre-foaming treatment is 40 to 50 times.

The fourth purpose of the invention is to provide a graphite polyphenyl flame-retardant plate which is mainly prepared from the graphite polyphenyl flame-retardant particles provided by the second purpose of the invention, wherein the density of the graphite polyphenyl flame-retardant plate is 35-50kg/m³。

The fifth purpose of the invention is to provide a preparation method of the graphite polyphenyl flame-retardant plate, which comprises the following steps:

after the graphite polyphenyl flame-retardant particles are formed by steam, sequentially cooling and aging to obtain a graphite polyphenyl flame-retardant plate;

preferably, the pressure of steam forming is 0.04-0.06MPa, and the temperature is 95-110 ℃;

preferably, the cooling treatment is carried out by adopting a vacuum cooling mode;

preferably, the temperature of the aging treatment is 60-70 ℃ and the time is 1-2 d.

The invention has at least the following beneficial effects:

the flame-retardant coating provided by the invention introduces the A-stage phenolic resin, the graphite halogen-free flame retardant and the film-forming substance to be matched with each other, so that the heat conductivity coefficient of a system is reduced, the expansibility of the system is improved, the bonding strength is enhanced, meanwhile, after the flame-retardant coating is coated on the surface of the graphite polyphenyl granules, an isolation cover for isolating air can be formed around the graphite polyphenyl granules, components are evaporated and take away a large amount of heat when being heated, the rest components are carbonized and crystallized to form a framework, the defect that the graphite polyphenyl granules burn when encountering fire is overcome, and the flame retardant property of the flame-retardant coating is enhanced.

In addition, the raw materials of the flame-retardant coating provided by the invention do not contain a halogen flame retardant, so that the flame-retardant coating is safe and environment-friendly, and a curing agent is not introduced to participate in the reaction, so that the safety of production and other links is ensured.

The flame-retardant graphite particles provided by the invention have the advantages that the flame-retardant coating is coated on the surfaces of the graphite polyphenyl particles, the isolation cover for isolating air is formed around the graphite polyphenyl particles, part of components are evaporated and take away a large amount of heat after being heated, and the rest of components are carbonized and crystallized to form a framework, so that the defect that the graphite polyphenyl particles burn when encountering fire is overcome, and the flame retardant property and the thermal stability of the graphite polyphenyl particles are enhanced.

The graphite polyphenyl flame-retardant plate provided by the invention is low in volume weight, excellent in flame-retardant property and mechanical property, safe and environment-friendly due to the fact that no halogen-containing flame retardant is introduced, and wide in application prospect.

The preparation process of the graphite flame-retardant plate provided by the invention is simple to operate, safe and environment-friendly, and easy to realize large-scale production.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to improve the flame retardant property of the graphite polystyrene board, a mode of adding a liquid flame retardant into graphite polystyrene particles is adopted, but the volatilization of the flame retardant is fast, and the flame retardant property of the graphite polystyrene board is seriously reduced after a period of time. Although the fireproof performance of the graphite polystyrene board prepared by the method is obviously improved, the capacity of the graphite polystyrene board is increased by multiple times, so that the heat insulation performance is seriously reduced, the water absorption is obviously improved, the requirements of energy conservation and environmental protection cannot be met, the graphite polystyrene board is easy to separate from a wall under the action of wind power, and serious potential safety hazards of high-altitude falling exist.

The surface of the graphite polyphenyl plate is coated with flame-retardant coating mainly prepared from thermosetting resin and flame retardant to improve the flame-retardant property, but the graphite polyphenyl flame-retardant plate prepared by the method has high heat conductivity coefficient and cannot meet the requirements of energy conservation and environmental protection in severe cold areas, graphite polyphenyl particles are connected by the thermosetting resin only, the adhesive force is insufficient, the potential safety hazards of separation from a wall body and high-altitude falling exist, meanwhile, a curing agent is required to be introduced in the production process, the curing agent belongs to dangerous chemicals, the potential safety hazards of burning and corrosion in production, transportation and the like are relieved, and the requirements on the process control of transportation, storage and use are high.

Therefore, the technical personnel in the field need to develop a graphite polyphenyl flame-retardant plate, which can eliminate potential safety hazards in the process of high-altitude falling and raw material transportation while ensuring the requirements of energy conservation and environmental protection.

According to a first aspect of the invention, the invention provides a flame retardant coating capable of improving the flame retardant property of a graphite polystyrene board, which comprises the following raw materials in parts by weight: 25-45 parts of A-stage phenolic resin, 10-20 parts of graphite, 25-40 parts of halogen-free flame retardant, 8-15 parts of film forming material and 5-10 parts of water.

Typically, but not by way of limitation, in the flame retardant coating provided by the present invention, the parts by weight of the phenolic resole resin are, for example, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 38, 40, 42, or 45 parts; the mass fraction of the graphite is 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20; the mass portion of the halogen-free flame retardant is 25, 28, 30, 32, 35, 38 or 40 parts, the mass portion of the film forming material is 8, 9, 10, 11, 12, 13, 14 or 15 parts, and the mass portion of the water is 5, 6, 7, 8, 9 or 10 parts.

[ A-stage phenol resin ]

Phenolic resin is a typical thermosetting polymer and is generally divided into A, B and C stages, wherein A stage phenolic resin has good dissolubility, dissolubility and fluidity, and the reaction degree p is less than the critical reaction degree at the beginning of gelationp_c(gel point).

[ graphite ]

Based on the fact that the existing flame-retardant coating which adopts thermosetting resin and flame retardant as main raw materials is high in heat conductivity coefficient and low in expansibility and cannot meet the requirements of energy conservation and environmental protection in severe cold areas and has potential safety hazards of high-altitude falling, the flame-retardant coating provided by the invention introduces graphite, thermosetting resin and halogen-free flame retardant to be matched with each other, so that the heat conductivity coefficient of a coating system is reduced, the expansibility of the system is improved, and the potential safety hazards are reduced while the requirements of energy conservation and environmental protection in severe cold areas are met.

In a preferable scheme of the invention, the particle size of the graphite is less than or equal to 80 meshes, so that the graphite is more favorably and uniformly distributed in the flame-retardant coating, and particularly when the particle size of the graphite is 7500-8000 meshes, the graphite is more uniformly dispersed in the prepared flame-retardant coating, and the flame-retardant effect is more excellent.

The particle size in the present invention refers to an average particle size.

Typically, but not by way of limitation, the particle size of the graphite is, for example, 80 mesh, 800 mesh, 7500 mesh, or 8000 mesh.

[ halogen-free flame retardant ]

The halogen-free flame retardant is introduced into the flame-retardant coating provided by the invention as a raw material, so that the safety and environmental protection performance of the system are improved.

In the present invention, the halogen-free flame retardant includes, but is not limited to, organic flame retardants and inorganic flame retardants, and inorganic flame retardants are preferable from the viewpoint of cost and flame-retardant stability.

Wherein, the organic flame retardant comprises any one or the combination of at least two of melamine, cyanuric acid or melamine cyanuric acid; the inorganic flame retardant comprises one or a combination of at least two of aluminum hydroxide, magnesium hydroxide, antimony trioxide or melamine urea, and the aluminum hydroxide is preferably used as the flame retardant from the viewpoints of comprehensive cost and flame retardant performance.

In a preferable scheme of the invention, the particle size of the halogen-free flame retardant is 0.5-100 μm, so that the halogen-free flame retardant is uniformly distributed in the flame retardant coating.

Typically, but not by way of limitation, the particle size of the halogen-free flame retardant is, for example, 0.5, 1, 2, 5, 10, 20, 50, 80 or 100. mu.m.

When the particle size of the halogen-free flame retardant is less than 0.5 mu m, agglomeration is easy to occur, so that the halogen-free flame retardant cannot be uniformly dispersed in the flame retardant coating, and when the particle size of the halogen-free flame retardant is more than 100 mu m, the particle size is too large, so that the halogen-free flame retardant is easy to settle and difficult to uniformly disperse in the flame retardant coating.

[ film-Forming Material ]

In order to facilitate the film formation of the flame-retardant coating and coat the surface of the graphite polyphenyl particles, the flame-retardant coating provided by the invention introduces a film-forming substance as a raw material.

In one embodiment of the present invention, the film-forming material includes, but is not limited to, one or a combination of at least two of silicone-acrylic emulsion, styrene-acrylic emulsion, or vinyl acetate-acrylic emulsion, preferably silicone-acrylic emulsion.

[ Water ]

In a preferred embodiment of the present invention, the water comprises one or a combination of at least two of purified water, deionized water and distilled water, so as to avoid introducing other impurities to affect the performance of the flame retardant coating.

[ auxiliary Agents ]

In a preferable scheme of the invention, corresponding auxiliary agents can be added into the flame-retardant coating to improve the performance of the flame-retardant coating.

The auxiliary agent includes, but is not limited to, any one or a combination of at least two of a thickener, a lubricant, a dispersant, a defoamer, and a filler.

Preferably, a thickening agent is added into the flame-retardant coating provided by the invention to improve the viscosity of the flame-retardant coating, so that the flame-retardant coating is favorably coated on the surface of the graphite polyphenyl particles.

Optionally, the thickener includes, but is not limited to, any one or a combination of at least two of sodium polyacrylate, carboxymethyl cellulose, or hydroxyethyl cellulose, preferably sodium polyacrylate.

Preferably, a lubricant is added into the flame-retardant coating provided by the invention to improve the wetting performance of the flame-retardant coating.

Optionally, organic silicon oil is used as a lubricant and added into the flame-retardant coating, so that the lubricating property of the flame-retardant coating is improved, and the waterproof property and defoaming property of the flame-retardant coating can be improved.

In a preferred scheme of the invention, when the flame-retardant coating comprises, by mass, 25-35 parts of A-stage phenolic resin, 8-10 parts of deionized water, 0.5 part of sodium polyacrylate, 10-20 parts of 80-mesh graphite, 30-35 parts of 30-80 μm aluminum hydroxide powder, 0.5-1 part of silicone oil and 8-15 parts of silicone acrylic emulsion, the flame-retardant coating has a lower thermal conductivity, and is more excellent in expansibility and bonding strength.

In one alternative of the invention, the preparation method of the flame-retardant coating comprises the following steps:

uniformly mixing the A-stage phenolic resin, graphite, the halogen-free flame retardant, the film forming substance, water and the optional auxiliary agent to obtain the flame-retardant coating.

It is noted that during the preparation of the flame retardant coating, the temperature needs to be lower than the crosslinking temperature of the phenolic resole resin.

According to a second aspect of the present invention, there is provided a fire retardant particle comprising a fire retardant coating and a graphite-polyphenyl particle, wherein the fire retardant coating is coated on the surface of the graphite-polyphenyl particle.

The flame-retardant graphite particles provided by the invention are coated with the flame-retardant coating provided by the first aspect of the invention, an isolation cover for isolating air is formed around the graphite polyphenyl particles, after the graphite polyphenyl particles are heated, part of components are evaporated and take away a large amount of heat, and the rest of components are carbonized and crystallized to form a framework, so that the defect that the graphite polyphenyl particles burn in fire is overcome, and the flame retardant performance and the thermal stability of the graphite polyphenyl particles are enhanced.

In one scheme of the invention, when the mass ratio of the graphite polyphenyl particles to the flame retardant coating is 1 (1.5-2), the graphite polyphenyl flame retardant plate which is prepared by uniformly coating the flame retardant coating on the surfaces of the graphite polyphenyl particles and has low heat conductivity, high bonding strength and mechanical property is easy to prepare.

Typically, but not by way of limitation, the mass of the graphite-polystyrene particles and the flame retardant coating is, for example, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1: 2.

Optionally, the graphite polyphenyl particles are pre-expanded graphite polyphenyl particles with the particle size of 4-5mm, so that the flame retardant coating in the graphite polyphenyl flame retardant plate prepared by the subsequent graphite polyphenyl flame retardant particles is more uniformly distributed, and the flame retardant performance is more excellent.

Typically, but not by way of limitation, the particle size of the graphitic polyphenyl particles is, for example, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 or 5 mm.

According to a third aspect of the present invention, there is provided a method for preparing a graphite-polyphenyl flame-retardant particle, comprising the steps of:

pre-foaming the graphite polyphenyl master batch to obtain graphite polyphenyl particles, uniformly mixing the graphite polyphenyl particles with the flame retardant coating to coat the surface of the foamed graphite polyphenyl particles with the flame retardant coating, and drying to obtain the graphite polyphenyl flame retardant particles.

Preferably, when the graphite polyphenyl master batch is controlled to be pre-foamed, the foaming ratio is controlled to be 40-50 times, and the graphite polyphenyl granules are obtained.

Typically, but not by way of limitation, the expansion ratio in the pre-foaming treatment is, for example, 40, 42, 45, 48 or 50 times.

Preferably, the pre-expanded particles are aged for 4-8h at 40-50 ℃ to promote the stability of the performance of the graphite polyphenyl particles.

Typically, but not limitatively, the maturation time is for example 4, 5, 6, 7 or 8 hours and the maturation temperature is for example 40, 42, 45, 48 or 50 ℃.

Optionally, a particle pre-foaming machine is used for foaming the graphite polyphenyl master batch, the pressure of the pre-foaming machine is controlled to be 0.04MPa, the temperature is controlled to be 100 ℃, and the foaming time is controlled to be 60 s.

Optionally, blowing the pre-foamed particles into a curing bin, controlling the temperature in the feeding bin to be 40-50 ℃, and curing for 4-8 h.

Preferably, drying is carried out by adopting a drying mode, wherein the drying temperature is 40-60 ℃, and the drying time is 5-10 min.

Typically, but not by way of limitation, the temperature of the oven is 40, 45, 50, 55, 56, 57, 58, 59, or 60 deg.C for a period of time, such as 5, 6, 7, 8, 9, or 10 minutes.

Optionally, adding the graphite polyphenyl particles into a coating machine, adding the flame-retardant coating, uniformly coating to enable the flame-retardant coating to be uniformly coated on the surfaces of the graphite polyphenyl particles to form flame-retardant coatings, adding the graphite polyphenyl particles coated with the flame-retardant coatings into a fluidized bed dryer to dry the surfaces, controlling the feeding temperature at the front end of a fluidized bed to be 55 ℃, the temperature at the middle end to be 60 ℃, the discharging temperature at the tail end to be 40 ℃, and the drying time to be 8-10min, and then storing the dried graphite polyphenyl flame-retardant particles for later use.

According to a fourth aspect of the present invention, there is provided a fire retardant panel made from the fire retardant particles of the second aspect of the present application, wherein the density of the fire retardant panel is 35-50kg/m³。

Typically, but not by way of limitation, the density of the graphite-polystyrene fire-retardant sheet is, for example, 35, 38, 40, 42, 45, 48 or 50kg/m³。

The graphite polyphenyl flame-retardant plate provided by the invention is mainly prepared from graphite polyphenyl flame-retardant particles, the flame-retardant coating forms an isolation cover for isolating air around the graphite polyphenyl particles, part of components are evaporated and take away a large amount of heat after being heated, and the rest of components are carbonized and crystallized to form a framework, so that the defect that the graphite polyphenyl plate burns when being heated is overcome, and the flame retardant property and the thermal stability of the graphite polyphenyl plate are enhanced.

In addition, the graphite polyphenyl flame-retardant plate provided by the invention is low in volume weight and excellent in mechanical strength, does not introduce any halogen-containing flame retardant, is safe and environment-friendly, and has wide application prospects.

According to a fifth aspect of the present invention, there is provided a method for preparing a graphite-polyphenyl flame-retardant sheet, comprising the steps of:

and (3) performing steam forming on the graphite polyphenyl flame-retardant particles, and then sequentially performing cooling and aging treatment to obtain the graphite polyphenyl flame-retardant plate.

In a preferred embodiment of the invention, the steam forming pressure is 0.04-0.06MPa and the temperature is 95-110 ℃.

Typically, but not by way of limitation, the vapor forming pressure is, for example, 0.04, 0.045, 0.05, 0.055, or 0.06MPa and the temperature is, for example, 95, 98, 100, 102, 105, or 110 ℃.

Preferably, the cooling treatment is carried out by vacuum cooling for 80-120s, preferably 100 s.

Typically, but not by way of limitation, the vacuum cooling time is, for example, 80, 90, 100, 110, or 120 seconds.

According to the invention, the cooled plate is aged to promote the performance of the graphite polyphenyl flame-retardant plate to be more stable.

Preferably, the temperature of the aging treatment is 60 to 70 ℃ and the time is 1 to 2 days, preferably 1 day.

Typically, but not by way of limitation, the temperature of the aging treatment is, for example, 60, 62, 64, 65, 66, 68 or 70 ℃ and the time of the aging treatment is, for example, 1, 1.5 or 2 days.

Optionally, the graphite polyphenyl flame-retardant plate is prepared according to the following steps:

(s1) adding the graphite polyphenyl flame-retardant particles into a full-automatic forming machine for steam forming, controlling the pressure of first steam in the forming machine to be 0.05MPa, the heating time of the bottom surface and the top surface to be 15s, controlling the second steam pressure to be 0.06MPa, controlling the heating time of four side surfaces to be 3s and controlling the temperature to be 100 ℃ so as to form the graphite polyphenyl flame-retardant plate;

(s2) cooling the steam-formed graphite polyphenyl flame-retardant plate for 100s in vacuum, and then aging for 1d at 65 ℃ to obtain the finished graphite polyphenyl flame-retardant plate.

According to a sixth aspect of the present invention, there is provided the use of a graphite-polyphenyl fire retardant panel in the field of building insulation.

In order to facilitate understanding of those skilled in the art, the technical solutions provided by the present invention will be further described below with reference to examples and comparative examples.

The raw material suppliers in the following examples and comparative examples are shown in Table 1 below, and all the raw materials not listed in Table 1 were obtained by commercial purchase.

TABLE 1

Example 1

The embodiment provides a flame-retardant coating, which comprises the following raw materials in parts by weight: 25 parts of A-stage phenolic resin, 20 parts of graphite, 25 parts of aluminum hydroxide powder, 0.5 part of sodium polyacrylate, 15 parts of silicone-acrylic emulsion, 0.5 part of organic silicone oil and 5 parts of deionized water, wherein the graphite is 8000 meshes.

Example 2

The embodiment provides a flame-retardant coating, which comprises the following raw materials in parts by weight: 45 parts of A-stage phenolic resin, 10 parts of graphite, 40 parts of aluminum hydroxide powder, 1 part of sodium polyacrylate, 8 parts of silicone-acrylic emulsion, 1 part of organic silicone oil and 10 parts of deionized water, wherein the graphite is 8000 meshes.

Example 3

The embodiment provides a flame-retardant coating, which comprises the following raw materials in parts by weight: 25 parts of A-stage phenolic resin, 20 parts of graphite, 30 parts of aluminum hydroxide powder, 0.5 part of sodium polyacrylate, 15 parts of silicone-acrylic emulsion, 0.5 part of organic silicone oil and 8 parts of deionized water, wherein the graphite is 8000 meshes.

Example 4

The embodiment provides a flame-retardant coating, which comprises the following raw materials in parts by weight: 35 parts of A-stage phenolic resin, 10 parts of graphite, 35 parts of aluminum hydroxide powder, 1 part of sodium polyacrylate, 8 parts of silicone-acrylic emulsion, 1 part of organic silicone oil and 10 parts of deionized water, wherein the graphite is 8000 meshes.

Example 5

The embodiment provides a flame-retardant coating, which comprises the following raw materials in parts by weight: 30 parts of A-stage phenolic resin, 15 parts of graphite, 32 parts of aluminum hydroxide powder, 1 part of sodium polyacrylate, 11 parts of silicone-acrylic emulsion, 1 part of organic silicone oil and 10 parts of deionized water, wherein the graphite is 8000 meshes.

Example 6

This example provides a flame retardant coating which differs from example 5 in that graphite having a particle size of 80 mesh is used.

Example 7

This example provides a flame retardant coating which differs from example 5 in that the particle size of the graphite employed is 800 mesh.

Comparative example 1

This comparative example provides a flame retardant coating which differs from example 5 in that calcium carbonate is used in place of graphite, and the remainder is the same as example 5 and will not be described again.

Comparative example 2

This comparative example provides a flame retardant coating which differs from example 5 in that a polyurethane resin is used in place of the phenolic resole resin, and the remainder is the same as example 5 and will not be described again.

Comparative example 3

This comparative example provides a flame retardant coating which differs from example 5 in that the amount of graphite used is 5 parts, while 10 parts of calcium carbonate are added, and the remainder is the same as example 5 and will not be described again.

Comparative example 4

This comparative example provides a flame retardant coating, which differs from example 5 in that the amount of graphite used is 30 parts, and the remainder is the same as example 5 and will not be described again.

Comparative example 5

This comparative example provides a flame retardant coating, which is different from example 5 in that 15 parts of aluminum hydroxide powder is used, 17 parts of calcium carbonate is added, and the rest is the same as example 5, and thus the description is omitted.

Comparative example 6

The comparative example provides a flame-retardant coating, which is different from the flame-retardant coating in example 5 in that the amount of aluminum hydroxide powder is 50 parts, and the rest is the same as that in example 5, and is not described again.

Comparative example 7

This comparative example provides a flame retardant coating which differs from example 5 in that 15 parts of phenolic resole resin is used, 15 parts of calcium carbonate are added, and the remainder is the same as example 5 and will not be described again.

Comparative example 8

This comparative example provides a flame retardant coating that differs from example 5 in that the amount of phenolic resole resin is 50 parts, and the remainder is the same as example 5 and will not be described again.

The flame retardant coatings provided in examples 1-7 and comparative examples 1-8 above were prepared as follows: the A-stage phenolic resin (polyurethane resin in comparative example 2), graphite, aluminum hydroxide powder, sodium acrylate, silicone-acrylate emulsion, organic silicone oil, deionized water and optional calcium carbonate are uniformly mixed at room temperature to obtain the flame-retardant coating.

Examples 8 to 14

Examples 8 to 14 each provide a graphite-polyphenyl flame-retardant particle prepared by coating the flame-retardant coating provided in examples 1 to 7 on the surface of a graphite-polyphenyl particle, wherein the mass ratio of the graphite-polyphenyl particle to the flame-retardant coating is 1:1.8, and the particle size of the graphite-polyphenyl particle is 4 to 5 mm.

Example 15

Embodiment 15 provides a graphite-polyphenyl flame-retardant particle, which is prepared by coating the flame-retardant coating provided in embodiment 5 on the surface of the graphite-polyphenyl particle, wherein the mass ratio of the graphite-polyphenyl particle to the flame-retardant coating is 1:1.5, and the graphite-polyphenyl particle is the same as the graphite-polyphenyl particles used in embodiments 8 to 14 in batch, which is not described herein again.

Example 16

Embodiment 16 provides a graphite-polyphenyl flame-retardant particle, which is prepared by coating the flame-retardant coating provided in embodiment 5 on the surface of the graphite-polyphenyl particle, wherein the mass ratio of the graphite-polyphenyl particle to the flame-retardant coating is 1:2, and the graphite-polyphenyl particle is the same as the graphite-polyphenyl particles adopted in embodiments 8 to 14 in batch, and details are not repeated here.

Comparative examples 9 to 16

Comparative examples 9 to 16 each provide a graphite-polyphenyl flame-retardant particle prepared by coating the flame-retardant coating provided in comparative examples 1 to 8 on the surface of the graphite-polyphenyl particle, wherein the mass ratio of the graphite-polyphenyl particle to the flame-retardant coating is 1:1.8, and the graphite-polyphenyl particle is the same as the graphite-polyphenyl particle used in examples 8 to 14 in batch and is not described herein again.

The graphite polyphenyl flame retardant particles provided by the above examples and comparative examples are prepared according to the following steps:

pre-foaming the graphite polyphenyl master batch to obtain graphite polyphenyl granules with the grain diameter of 4-5mm, then uniformly mixing the graphite polyphenyl granules with the flame retardant coating to coat the surface of the graphite polyphenyl granules with the flame retardant coating, then drying the surface in a fluidized bed dryer, controlling the feeding temperature at the front end of a fluidized bed to be 55 ℃, the middle end temperature to be 60 ℃, the discharging temperature at the tail end to be 40 ℃, and drying for 8-10min to obtain the graphite polyphenyl flame retardant granules.

Examples 17 to 25

Examples 17-25 each provide a graphite-polyphenyl flame retardant panel prepared from the graphite-polyphenyl flame retardant particles provided in examples 8-16, respectively.

Comparative examples 17 to 24

Comparative examples 17-24 provide a graphite-polyphenyl flame retardant sheet, respectively, prepared from the graphite-polyphenyl flame retardant particles provided in comparative examples 9-16, respectively.

The graphite polyphenyl flame-retardant plates provided by the above examples and comparative examples are prepared according to the following steps:

(1) adding the graphite polyphenyl flame-retardant particles into a full-automatic forming machine for steam forming, controlling the pressure of first steam in the forming machine to be 0.05MPa, the heating time of the bottom surface and the top surface to be 15s, the second steam pressure to be 0.06MPa, the heating time of four side surfaces to be 3s and the temperature to be 100 ℃ so as to form the graphite polyphenyl flame-retardant plate;

(2) and (3) cooling the graphite polyphenyl flame-retardant plate formed by steam for 100s in vacuum, and then aging for 1d at 65 ℃ to obtain the finished graphite polyphenyl flame-retardant plate.

Test example 1

The graphite polyphenyl flame retardant sheets provided in examples 17 to 25 and comparative examples 17 to 24 were subjected to performance tests according to JGT536-2017 "Heat cured composite polystyrene foam insulation board" and GB8624-2012 "Combustion Performance Classification of building materials and products", respectively, and the results are shown in Table 2 below.

TABLE 2

As can be seen from the comparison between examples 17-21, examples 24-25 and comparative examples 17-24, the flame retardant coating system provided by the invention has the advantages that the A-stage phenolic resin, the graphite halogen-free flame retardant and the film forming substance in a specific mass ratio are matched, so that the heat conductivity coefficient of the flame retardant system is reduced, the expansibility of the system is improved, the bonding strength is enhanced, the defect that the graphite polyphenyl particles burn in case of fire is overcome, and the flame retardant property of the graphite polyphenyl particles is enhanced.

As can be seen from the comparison of examples 17-21 and examples 24-25 with comparative example 20, the adhesion strength of the flame retardant system is poor when the graphite powder is excessive, because excessive graphite powder causes the flame retardant system to be unevenly distributed and unstable, and agglomeration of the graphite powder is easy to occur, and finally the adhesion strength of the system is poor.

As can be seen by comparing examples 17-21 and examples 24-25 with comparative example 22, the excessive amount of aluminum hydroxide results in poor bonding strength and high thermal conductivity of the flame retardant system, because the excessive amount of aluminum hydroxide causes uneven distribution of the flame retardant system, easy sedimentation and delamination, poor coating efficiency when mixed with particles, and finally results in poor bonding strength and high thermal conductivity of the flame retardant system.

As can be seen by comparing examples 17-25 and examples 24-25 with comparative example 23, the phenolic resin of A stage is less, and the fire-retardant system has poor fire-retardant performance because the phenolic resin of A stage is less, the fire-retardant system is unevenly distributed, is easy to settle and delaminate, has poor coating efficiency when being mixed with particles, and finally causes the problems of poor bonding strength of the system, high thermal conductivity and the like, and the less phenolic resin of A stage can cause insufficient fire-proof separation bins formed when meeting fire, possibly causes melting and dropping of the graphite polyphenyl particles, and has poor fire-retardant performance.

As can be seen by comparing examples 17-21, examples 24-25 with comparative example 24, the amount of the A-stage phenolic resin is large, and the compression strength and the weather resistance of the flame-retardant system are poor, because the amount of the A-stage phenolic resin is large, the load on equipment in the production process is large, and the curing speed is slow, so that the production efficiency is low; and excessive addition of phenolic resin can reduce the compressive strength and weather resistance of the system.

As can be seen from the comparison between examples 23-24 and example 21, the flame retardant system prepared when the particle size of the graphite is 8000 meshes has better fire resistance, compressive strength and weather resistance, because the smaller particle size of the graphite is more beneficial to uniformly distributing in the flame retardant system when the particle size is 8000 meshes, thereby being more beneficial to improving the fire resistance, compressive strength and weather resistance of the flame retardant system.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.