KR102716785B1 - Phenol foam, method of producing the same, and insulating material - Google Patents

Abstract

A phenolic foam is provided, wherein the mass reduction rate (W1) is 5% to 35% after applying 50 kW of radiant heat to the foam for 5 minutes according to KS F ISO 5660-1.

Description

Phenolic foam, method of producing the same, and insulating material comprising the same {PHENOL FOAM, METHOD OF PRODUCING THE SAME, AND INSULATING MATERIAL}

The present invention relates to a phenol foam, a method for producing the same, and an insulating material comprising the same.

Insulation is an essential material used to prevent energy loss in buildings. As the importance of green growth continues to be emphasized worldwide due to global warming, insulation is becoming more important to minimize energy loss.

There are thermosetting foam insulation, EPS (expanded polystyrene foam) insulation, XPS (extruded polystyrene foam) insulation, and vacuum insulation as insulation materials. Among them, thermosetting foam insulation is widely used because it has the best insulation properties among existing materials except for vacuum insulation. However, due to the fundamental limitations of organic substances, its fire stability is bound to be weaker than that of inorganic insulation.

In addition, thermosetting foams such as urethane foam and phenol foam are manufactured by including surface materials in the manufacturing process, so flame retardancy can be improved by applying surface materials made of aluminum. However, in extreme situations such as an actual fire, the flame resistance of the surface material is greatly reduced, so it is very important to fundamentally maintain the flame retardancy of the foam.

The purpose of the present invention is to provide a phenolic foam having excellent flame retardancy by preventing the propagation and spread of flame with a low mass reduction rate of the foam in case of fire, and at the same time having excellent thermal insulation and physical properties.

Another object of the present invention is to provide a method for producing the phenol foam.

Another object of the present invention is to provide an insulating material comprising the phenol foam.

The purposes of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be easily understood that the purposes and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

According to the present invention, a phenol foam can be provided having a mass reduction rate (W1, %) of 5% to 35% after applying 50 kW/m ² radiant heat according to KS F ISO 5660-1 to the foam for 5 minutes.

In addition, the present invention provides a method for producing a phenolic foam, comprising: a step of preparing a flame retardant composition including a subject matter, a curing agent, a foaming agent and a first flame retardant including a phenolic resin; a step of stirring the subject matter, the curing agent, the foaming agent and the flame retardant composition to produce a foam composition; and a step of foaming and curing the foam composition; wherein the first flame retardant is phosphorus, and a mass reduction rate (W1, %) after applying 50 kW/m ² radiant heat according to KS F ISO 5660-1 to the foam for 5 minutes is 5% to 35%.

In addition, an insulating material including the phenol foam according to the present invention can be provided.

The phenol foam according to the present invention has excellent flame retardancy by preventing the propagation and spread of flame with a low mass reduction rate during combustion, and at the same time can exhibit excellent thermal insulation properties and physical properties such as excellent compressive strength and dimensional stability.

In addition, the insulation material according to the present invention can have improved flame retardancy and excellent insulation properties by including the phenol foam, and can exhibit properties such as excellent compressive strength and dimensional stability.

In addition to the effects described above, specific effects of the present invention are described below together with specific details for carrying out the invention.

Figure 1 is a schematic diagram briefly illustrating a method for measuring the dimensional stability of a phenol foam of the present invention.

The above-mentioned objects, features and advantages are described in detail below, so that those with ordinary skill in the art to which the present invention pertains can easily practice the technical idea of the present invention. In describing the present invention, if it is judged that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, phenol foams according to some embodiments of the present invention will be described.

One embodiment of the present invention provides a phenol foam having a mass reduction rate (W1, %) of 5% to 35% after applying 50 kW/m ² radiant heat according to KS F ISO 5660-1 to the foam for 5 minutes.

The above mass reduction rate (W1, %) can be obtained by the following equation 3.

[Formula 3]

Mass loss rate (W1, %) = (Wi-Wf)/Wi X 100

In the above equation 3, Wi is the initial mass of the foam before applying the radiant heat, and Wf means the later mass of the foam after applying 50 kW/m ² radiant heat for 5 minutes according to KS F ISO 5660-1.

Due to various recent fire accidents, insulation materials that are essential for buildings are required to have not only excellent insulation properties but also improved flame retardancy. However, thermosetting foams are bound to be less fire-resistant than inorganic insulation materials due to the fundamental limitations of organic materials. Therefore, it is common to provide flame retardancy to the foam through surface treatment such as aluminum facing, but there is a risk that the facing may fall off in an actual fire, and if the facing falls off, the fire is likely to spread. In addition, among thermosetting foams, phenol foams have rigid characteristics compared to other thermosetting foams and the viscosity of the resin is also high, making it difficult to manufacture foams suitable for insulation using other additives such as flame retardants.

In addition, conventional thermosetting foams without flame retardants tend to easily lose material when organic substances such as thermosetting resins and foaming agents burn and shrink in the event of a fire, and carbonized films tend not to form easily. In addition, even if a flame retardant such as phosphate is added to the foam to form a carbonized film, if the carbonized film is formed after a large amount of organic substances in the thermosetting foam have burned and disappeared, the foam itself can easily fall off and break, which can cause a secondary fire in which the foam spreads the fire.

The mass reduction rate (W1) of the above phenol foam is about 5% to about 35% after applying 50 kW/m ² radiant heat to the foam for 5 minutes according to KS F ISO 5660-1. For example, the mass reduction rate of the above phenol foam may be about 5% to about 33%, about 5% to about 30%, about 5% to about 25%, or about 5% to less than about 20%.

The above phenol foam can secure evacuation time in case of fire and prevent fire from spreading by having a low mass reduction rate within the above range. Specifically, if the mass reduction rate of the above phenol foam exceeds the above range, too much phenol foam is already lost before a carbon film is formed, so the foam is easily detached and easily broken by a small external impact, which may cause fire to spread.

In addition, although the mass reduction rate can be reduced to below the above range by including an excessive amount of flame retardant, there is a problem of reduced insulation.

The above phenol foam can satisfy the following equation 1 in terms of the relationship between the mass reduction rate (W2) after applying 50 kW/m ² radiant heat to the foam for 10 minutes according to KS F ISO 5660-1 and the mass reduction rate (W1) after applying the heat for 5 minutes.

[Formula 1]

W1 + 3.0% < W2 < W1 + 20.0%

For example, the phenol foam can satisfy W1 + 8.0% < W2 < W1 + 17.0%. Specifically, the phenol foam satisfies Equation 1 in the relationship between the mass reduction rate (W2) when the radiant heat is applied for 10 minutes and the mass reduction rate (W1) when the radiant heat is applied for 5 minutes, so that the foam can form a carbon film well in the early stage of the combustion reaction, and at the same time, the foam can have a stable carbon film. Accordingly, the foam can exhibit excellent flame retardancy because the combustion reaction can occur slowly even though time is cured. For example, when the W2 exceeds the range in relation to W1, it is difficult to secure evacuation time in case of a fire, and there may be a problem that the foam causes a secondary fire. In addition, when it is less than the range, it can be seen that the flame retardancy is secured by including an excessive amount of flame retardant, but there may be a problem that the thermal conductivity increases and the insulation deteriorates.

And, the mass reduction rate (W2) of the phenol foam after applying 50 kW of radiant heat for 10 minutes according to KS F ISO 5660-1 can satisfy the following equation 2 in the relationship with the mass reduction rate (W1) after applying the heat for 5 minutes.

[Formula 2]

0.25 < (W2-W1)/W1 < 0.75

For example, if the value of Equation 2 of the phenol foam exceeds the above range, there may be a problem that the carbon film formed at the beginning of combustion is not stable, and the foam including the carbon film continuously or exponentially causes a combustion reaction over time, causing fire propagation and spread. In addition, although the mass reduction rate can be made below the above range by including an excessive amount of flame retardant, there is a problem that the insulation property deteriorates. In the above Equation 2, 0.25 < (W2-W1)/W1 < 0.7 may be satisfied.

The above phenol foam comprises a phenolic resin, a curing agent, a foaming agent and a first flame retardant, and the first flame retardant may be phosphorus.

Generally, flame retardancy can be provided to thermosetting foam by using a phosphorus-based flame retardant such as phosphate. However, when using a phosphorus-based flame retardant such as phosphate, flame retardancy is improved, but there is a problem that the foam cells are destroyed during the foaming process and the flame retardancy is reduced. In addition, when using aluminum hydroxide (ATH) as a flame retardant in thermosetting foam, the aluminum hydroxide is a basic substance and can neutralize the acid curing agent, which can reduce the curing reactivity of the phenol resin. Accordingly, there is a problem that the insulation properties of the foam manufactured from it are reduced.

The above phenol foam comprises a phenol resin, a curing agent, a foaming agent, and a first flame retardant which is phosphorus, and thus can have not only improved flame retardancy but also excellent insulation properties, despite the trade-off between flame retardancy and insulation properties. In addition, the above phenol foam can exhibit properties such as excellent compressive strength and dimensional stability.

Specifically, the phenol foam includes a phenol resin. The phenol resin can be obtained by a reaction of phenol and formaldehyde, and may include, for example, a resole-based phenol resin (hereinafter, referred to as 'resole resin'). In addition, the first flame retardant or the composite flame retardant including the first flame retardant and the second flame retardant can be well mixed with the phenol resin including a benzene ring and can be uniformly dispersed and foamed. Accordingly, the phenol foam can exhibit improved insulation properties in terms of not only initial insulation properties but also long-term insulation properties while stably forming foam cells of uniform and small sizes while including the flame retardant.

The above phenolic resin may be included in the phenolic foam in an amount of about 30 wt% to about 90 wt%, or about 50 wt% to about 90 wt%, or about 55 wt% to about 90 wt%. The phenolic foam can stably form small-sized foam cells and implement excellent thermal conductivity by including the phenolic resin in an amount within the above range.

The above phenol foam comprises a curing agent. The curing agent may comprise one acid curing agent selected from the group consisting of toluene sulfonic acid, xylene sulfonic acid, benzene sulfonic acid, phenol sulfonic acid, ethylbenzene sulfonic acid, styrene sulfonic acid, naphthalene sulfonic acid, and combinations thereof. The above phenol foam may exhibit appropriate crosslinking, curing, and foaming properties by comprising the curing agent.

The above phenol foam may include a blowing agent. For example, the blowing agent may include one selected from the group consisting of a hydrofluoroolefin (HFO) compound, a hydrocarbon compound, and a combination thereof. Specifically, the hydrofluoroolefin compound may include at least one selected from the group consisting of monochlorotrifluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, hexafluorobutene, and a combination thereof. In addition, the hydrocarbon compound may include an aliphatic hydrocarbon having 1 to 8 carbon atoms. For example, the hydrocarbon compound may be a chlorine-substituted or unsubstituted aliphatic hydrocarbon. For example, it may include at least one selected from the group consisting of dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride, n-butane, isobutane, n-pentane, isopentane, cyclopentane, hexane, heptane, cyclopentane, and combinations thereof. The phenol foam may exhibit excellent insulating properties along with environmental friendliness by including an aliphatic hydrocarbon having 1 to 8 carbon atoms.

In addition, the phenol foam may contain one surfactant selected from the group consisting of amphoteric, cationic, anionic, nonionic surfactants, and combinations thereof. For example, the phenol foam may contain an ethoxylated castor oil surfactant, i.e., a nonionic surfactant.

The above phenol foam can easily disperse components such as a first flame retardant including phosphorus or a composite flame retardant including a first flame retardant including phosphorus and a second flame retardant by including the surfactant, and can stably form an appropriate foam structure in the phenol foam to realize excellent thermal conductivity and excellent physical strength.

Phenolic foam can exhibit excellent insulation properties by including the above phenolic resin and the above foaming agent. However, the above materials are highly flammable and exhibit a high mass loss rate when burned in a fire, so that a large portion of the foam can be lost before the carbon film is formed, and can easily fall off.

The above phenol foam comprises phosphorus as a first flame retardant together with the above phenol resin, the above curing agent, and the above foaming agent, and can satisfy the above formulas 1 and 2, stably form a carbon film easily, and exhibit excellent flame retardancy with a low mass reduction rate in the above-mentioned range. In addition, the above phenol foam can have excellent physical properties such as thermal insulation, compressive strength, and dimensional stability.

Specifically, the first flame retardant, phosphorus, in the phenol foam can form a carbon film (char) well with excellent carbonization during combustion. In particular, the phenol resin foam can form a carbon film (char) better by including phosphorus in the phenol resin containing a benzene ring. In addition, the phosphorus can capture hydrogen radicals and hydroxyl radicals generated during combustion to prevent a combustion reaction from occurring in a chain reaction, thereby quickly blocking the spread of fire.

The above phosphorus can be distinguished into white phosphorus, red phosphorus, black phosphorus, and red phosphorus depending on the structural state and color of the phosphorus. Specifically, the phenol foam can contain red phosphorus. The phenol foam can be easily handled when forming the phenol foam by containing red phosphorus having an appropriate structure. In addition, by controlling the rate of carbonization film (Char) formation during combustion of the phenol foam, it can satisfy the above formulas 1 and 2 with a low mass reduction rate, and can have excellent flame retardancy and thermal insulation properties at the same time. For example, the phenol foam can contain 80% or more or 100% of the phosphorus.

The above phenol foam contains only the first flame retardant as a flame retardant, and the first flame retardant may be included in an amount of about 0.9 parts by weight to about 15 parts by weight based on 100 parts by weight of the phenol foam. For example, it may be included in an amount of about 1 part by weight to about 12 parts by weight, about 1 part by weight to about 10 parts by weight, or about 2 parts by weight to about 8 parts by weight. The phenol foam may include the first flame retardant in an amount within the above range so as to be uniformly dispersed in the phenol resin and maintain excellent thermal insulation properties. In addition, the combustion rate and degree of the foam may be controlled during a fire, and a carbonization film may be stably formed, thereby satisfying Equations 1 and 2 with a low mass reduction rate and exhibiting excellent flame retardancy. In addition, the phenol foam may have excellent physical properties such as compressive strength and dimensional stability.

Specifically, when the content of the first flame retardant is less than the above range, the mass reduction rate may not exhibit a sufficient flame retardant effect if it exceeds the above range, may not prevent fire propagation in the event of a fire, and dimensional stability may deteriorate. In addition, when it exceeds the above range, the viscosity of the foam composition may increase significantly, which may cause problems during foaming. For example, when the viscosity of the foam composition increases, the torque of the mixer is increased during stirring, which may cause the temperature of the foam composition to rise significantly. In addition, the amount of blowing agent volatilization increases, which may deteriorate the insulation. In addition, due to the high viscosity of the foam composition, the phosphorus, blowing agent, and curing agent may not be evenly dispersed, which may cause a problem in that the physical properties of the foam are not uniformly formed, such as a decrease in the compressive strength.

The above phenol foam further includes a second flame retardant, and includes a composite flame retardant including the first flame retardant and the second flame retardant, wherein the second flame retardant may include one selected from the group consisting of pentaerythritol-based compounds, melamine cyanurate, trialkyl phosphates, and combinations thereof.

The second flame retardant has excellent compatibility with the first flame retardant, the phosphorus, and can be mixed well, suppresses the agglomeration of small-sized phosphorus particles, allows the composite flame retardant to be evenly dispersed, and can provide excellent insulation along with improved flame retardancy by uniformly foaming.

Specifically, the pentaerythritol-based compound can form a carbon film (Char) better by binding between the phosphorus and phosphorus during combustion, thereby better controlling the equations 1 and 2 within the above range with a low mass reduction rate, and preventing the fire from spreading. The pentaerythritol-based compound may include one selected from the group consisting of monopentaerythritol, dipentaerythritol, tripentaerythritol, and combinations thereof.

And, the melamine cyanurate can delay ignition by lowering the combustion heat through the absorption of heat by the sublimation and decomposition of melamine itself and the endothermic decomposition of hydrogen bonds within the melamine cyanurate structure during combustion. In addition, the melamine cyanurate can dilute oxygen by generating nitrogen and/or ammonia gas during combustion. And, the melamine cyanurate can form a carbon film including a multi-ring structure such as melem and melon by condensing the melamine itself generated by the combustion decomposition. At this time, the melamine cyanurate acts together when the phosphorus is formed to enhance the phosphorus carbon film formation reaction, and forms a stable carbon film to better control the mass reduction rate and the equations 1 and 2 within the above ranges, and prevent the spread of fire. In addition, the melamine cyanurate can form uniform and small-sized cells in the phenol foam. In addition, the above melamine cyanurate can act as a nucleating agent in the foam, and can form a cell structure more stably, thereby further improving the insulating properties.

The average particle size of the above melamine cyanurate may be about 1 ㎛ to 20 ㎛ or about 1 ㎛ to 10 ㎛. The particle size can be measured by a laser particle size analyzer (Laser Particle Size Analyzer, model name: BT-2000). If the average particle size of the melamine cyanurate is less than the above range, the viscosity of the composition containing it may increase and there may be a problem of poor dispersion. In addition, if it exceeds the above range, there may be a problem of reduced flame retardancy.

And, the trialkyl phosphate may include one compound selected from the group consisting of trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris (1-chloro 2-propyl) phosphate, tri (2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropyl phenyl) phosphate, tris (phenyl phenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropyl phenyl) phenyl phosphate, monoisodecyl phosphate, and combinations thereof. The trialkyl phosphate can improve the uniform dispersion of the phosphorus, suppress the agglomeration of small-sized phosphorus particles, so that the composite flame retardant can be evenly dispersed, and can exhibit excellent insulation along with improved flame retardancy by uniformly foaming. Specifically, the trialkyl phosphate may be triethyl phosphate, and is well mixed with the phosphorus with excellent compatibility to better control the mass reduction rate and equations 1 and 2 within the above range, and prevent fire from spreading, thereby further improving the thermal insulation along with excellent flame retardancy.

The composite flame retardant may be included in an amount of about 1 part by weight to about 20 parts by weight based on 100 parts by weight of the phenol foam. For example, the composite flame retardant may be included in an amount of about 1.5 parts by weight to about 15 parts by weight or about 2 parts by weight to about 10 parts by weight. The phenol foam may contain the composite flame retardant in an amount within the above range to control the combustion rate of the foam in the event of a fire and stably form a carbonized film, thereby satisfying Equations 1 and 2 with a low mass reduction rate, and may have excellent flame retardancy and excellent physical properties such as excellent thermal insulation, compressive strength, and dimensional stability.

Specifically, when the content of the composite flame retardant is less than the above range, the mass reduction rate may exceed the above range, so that a carbon film may not be stably formed and a sufficient flame retardant effect may not be exhibited. In addition, when the content of the composite flame retardant is exceeded, it is uneconomical because a lot of cost is required compared to the increased flame retardant effect, and the viscosity of the foam composition may increase significantly, which may cause problems during foaming. For example, when the viscosity of the foam composition increases due to the content of the composite flame retardant, the torque of the mixer is high during stirring, so the temperature of the foam composition increases significantly. In addition, the amount of blowing agent volatilization increases, which may deteriorate the insulation. In addition, due to the high viscosity of the foam composition, the phosphorus, blowing agent, and curing agent may not be evenly dispersed, which may cause a problem in that the physical properties of the foam are not uniformly formed.

The above phenol foam includes the composite flame retardant, and at this time, the first flame retardant may be included in an amount of 0.9 to 15 parts by weight relative to 100 parts by weight of the phenol foam. For example, the first flame retardant may be included in an amount of about 1 to 12 parts by weight, about 1 to 10 parts by weight, or about 2 to 8 parts by weight relative to 100 parts by weight of the phenol foam. In addition, the second flame retardant may be included in an amount of 0.1 to 7 parts by weight relative to 100 parts by weight of the phenol foam. For example, the second flame retardant may be included in an amount of about 0.1 to 4 parts by weight. The above composite flame retardant, together with the first flame retardant, contains the second flame retardant in the above range to control the combustion rate of the foam in case of a fire and form a stable carbonized film, thereby satisfying Equations 1 and 2 with a low mass reduction rate, and can have excellent flame retardancy as well as excellent physical properties such as excellent heat insulation, compressive strength, and dimensional stability. When the content of the second flame retardant is less than the above range, it may not react properly with the phosphorus and may not form an appropriate carbonized film. In addition, the formation speed of the carbonized film may not be sufficient, so that the mass reduction rate exceeds the above range and the flame retardancy improvement effect may be reduced. In addition, when the content of the second flame retardant exceeds the above range, the second flame retardant compound itself, which does not react with phosphorus in case of a fire and remains, may burn, thereby increasing the mass reduction rate and deviating from Equations 1 and 2, thereby lowering the flame retardancy.

The weight ratio of the first flame retardant to the second flame retardant can be about 1:0.05 to about 1:1.2. For example, the weight ratio of the first flame retardant to the second flame retardant can be about 1:0.07 to about 1:0.6, or about 1:0.1 to about 1:0.5. The phenolic foam can contain the first flame retardant and the second flame retardant in the weight ratio within the above range, thereby better controlling the mass reduction rate and the equations 1 and 2 within the above range, and exhibiting improved flame retardancy by preventing fire from spreading, and at the same time exhibiting excellent thermal insulation properties and excellent physical properties. Specifically, if the second flame retardant is mixed in an amount below the above range, the synergistic effect of the causal relationship is minimal, which causes an uneconomical problem. In addition, if the second flame retardant is mixed in an amount exceeding the above range, the flame retardancy may be reduced, it may be difficult to secure a high independent cell ratio, and it may be difficult to secure sufficient compressive strength.

The above composite flame retardant may include a phosphorus and pentaerythritol-based compound, and a weight ratio of the phosphorus to the pentaerythritol-based compound may be from about 1:0.05 to about 1:0.6. For example, the weight ratio of the phosphorus to the pentaerythritol-based compound may be from about 1:0.07 to about 1:0.5.

The composite flame retardant may include a phosphorus and a melamine cyanurate compound, and a weight ratio of the phosphorus to the melamine cyanurate compound may be from about 1:0.05 to about 1:0.8. For example, the weight ratio of the phosphorus to the melamine cyanurate compound may be from about 1:0.07 to about 1:0.6.

The above composite flame retardant may include phosphorus and a trialkyl phosphate, and the weight ratio of the phosphorus to the trialkyl phosphate may be from about 1:0.05 to about 1:0.8. For example, the weight ratio of the phosphorus to the trialkyl phosphate may be from about 1:0.07 to about 1:0.6.

In the relationship between the first flame retardant and the second flame retardant, if the content of each of the first flame retardants exceeds the above range, the mass reduction rate increases when burning due to the second flame retardant remaining without reacting with the first flame retardant, and the flame retardancy may be reduced beyond the above equations 1 and 2. In addition, if the content of the second flame retardant is less than the above range, the dispersibility of phosphorus in the phenol foam may be poor, and the insulation may not be sufficient. In addition, the synergistic flame retardancy effect according to the combination of the second flame retardant and the phosphorus may not appear.

And, the composite flame retardant may include phosphorus, a pentaerythritol-based compound, and melamine cyanurate, and may include 1 to 50 parts by weight of the pentaerythritol-based compound and 1 to 80 parts by weight of the melamine cyanurate relative to 100 parts by weight of the phosphorus. For example, relative to 100 parts by weight of the phosphorus, the pentaerythritol-based compound may be included in an amount of about 5 to about 30 parts by weight, and the melamine cyanurate may be included in an amount of about 5 to about 40 parts by weight.

If the content of the pentaerythritol-based compound compared to the melamine cyanurate is below the above range, the carbon film formed through a synergistic effect with the phosphorus and melamine cyanurate may be insufficient, and if it exceeds the above range, there may be a problem in which the flame retardancy is reduced as the excess pentaerythritol-based compound remaining without reacting burns.

The composite flame retardant may include the phosphorus, melamine cyanurate, and trialkyl phosphate, and may include about 1 part by weight to about 80 parts by weight of the melamine cyanurate and about 1 part by weight to about 80 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the phosphorus. For example, the composite flame retardant may include about 5 parts by weight to about 40 parts by weight of the melamine cyanurate and about 5 parts by weight to about 40 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the phosphorus.

If the content of the melamine cyanurate compared to the trialkyl phosphate is below the above range, there is a problem of insufficient formation of a carbon film formed through a synergistic effect with the trialkyl phosphate, and if it exceeds the above range, there may be a problem of excessive melamine cyanurate hindering cell formation of the phenol foam, thereby lowering the thermal conductivity.

The composite flame retardant may include the phosphorus, the pentaerythritol-based compound, and the trialkyl phosphate, and may include about 1 part by weight to about 50 parts by weight of the pentaerythritol-based compound and about 1 part by weight to about 80 parts by weight of the trialkyl phosphate relative to 100 parts by weight of the phosphorus. For example, the composite flame retardant may include about 5 parts by weight to about 30 parts by weight of the pentaerythritol-based compound and about 5 parts by weight to about 40 parts by weight of the trialkyl phosphate relative to 100 parts by weight of the phosphorus.

If the content of the pentaerythritol-based compound compared to the trialkyl phosphate is below the above range, the formation of a carbon film formed synergistically with the trialkyl phosphate may be insufficient, and if it exceeds the above range, there may be a problem in which the flame retardancy is reduced as the excess pentaerythritol-based compound remaining without reacting burns.

The composite flame retardant may include the phosphorus, the pentaerythritol-based compound, the melamine cyanurate, and the trialkyl phosphate, and may include about 1 part by weight to about 30 parts by weight of the pentaerythritol-based compound, about 1 part by weight to about 50 parts by weight of the melamine cyanurate, and about 1 part by weight to about 60 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the phosphorus. For example, the composite flame retardant may include about 3 parts by weight to about 20 parts by weight of the pentaerythritol-based compound, about 5 parts by weight to about 30 parts by weight of the melamine cyanurate, and about 5 parts by weight to about 40 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the phosphorus.

When the weight ratio of the melamine cyanurate and the trialkyl phosphate compared to the pentaerythritol-based compound is below the above range, there is a problem in that the synergistic effect of improving flame retardancy is not sufficiently exerted by interacting with the first flame retardant, phosphorus, and when the weight ratio of the melamine cyanurate and the trialkyl phosphate exceeds the above range, there may be a problem in that the formation of the cell structure of the phenol foam is hindered due to an excessive amount of flame retardant, resulting in structural instability and deterioration of insulation.

A composite flame retardant comprising the above phenolic resin, a curing agent, a foaming agent, and a first flame retardant that is phosphorus or the first flame retardant and a second flame retardant, wherein the phenolic foam may have a thermal conductivity of about 0.016 W/m K to about 0.029 W/m K measured at an average temperature of 20° C. according to KS L 9016. For example, the phenol foam may have a thermal conductivity measured at an average temperature of 20°C according to KS L 9016 of about 0.016 W/m K to about 0.025 W/m K, about 0.016 W/m K to about 0.023 W/m K, about 0.016 W/m K or more and less than about 0.020 W/m K, or about 0.016 W/m K or more and less than about 0.0195 W/m K. The thermal conductivity represents the initial insulating properties of the foam, and the phenol foam can improve not only the flame retardancy but also the insulating properties by including the flame retardant.

And, the phenol foam may have a thermal conductivity of about 0.017 W/m K to about 0.029 W/m K measured at an average temperature of 20° C. after drying at 70° C. for 7 days and then drying at 110° C. for 14 days according to EN13166. For example, it may be about 0.017 W/m K to about 0.025 W/m K or about 0.017 W/m K or more and less than about 0.023 W/m K. The thermal conductivity represents long-term thermal insulation properties of the foam, and the phenol foam may exhibit long-term thermal insulation properties that are the same as or in a similar range to the initial thermal insulation properties, including the composite flame retardant.

At the same time, the phenol foam may have a total heat release amount (THR600s) of about 2.0 MJ/m2 to about 15 MJ/m2 for 10 minutes as measured by a cone calorimeter according to KS F ISO 5660-1. For example, it may be about 2.0 MJ/m2 to about 10.0 MJ/m2 or about 2.0 MJ/m2 to less than about 8.0 MJ/m2. That is, the phenol foam may have excellent flame retardancy close to being quasi-noncombustible even without a separate facing material.

In addition, the phenol foam may exhibit excellent flame retardancy, with a total heat release (THR300s) for 5 minutes by a cone calorimeter according to KS F ISO 5660-1 of about 1.0 MJ/m2 to about 12 MJ/m2, for example, about 1.0 MJ/m2 to about 7.5 MJ/m2, about 1.0 MJ/m2 to about 5 MJ/m2, or about 1.0 MJ/m2 or more and less than about 4 MJ/m2.

Additionally, the independent cell ratio of the phenol foam may be from about 75% to about 98%. For example, the independent cell ratio of the phenol foam may be from about 80% to about 95%.

In general, when a phosphorus flame retardant such as phosphate is used in phenol foam to improve flame retardancy, the flame retardancy can be improved, but there is a problem that the foam cells are destroyed during the foaming process, resulting in a decrease in the independent cell ratio and a decrease in the flame retardancy. On the other hand, the phenol foam can maintain a high independent cell ratio within the above range by including the phenol resin, the curing agent, the foaming agent, and the flame retardant. In addition, it can exhibit excellent insulation along with excellent flame retardancy or semi-flammability within the above range.

In the case of phosphorus-based flame retardants, such as phosphates, which are generally used as flame retardants, they have poor compatibility with thermosetting resins and may destroy the foam cell structure, thereby reducing physical properties, such as compressive strength and flexural failure load. Meanwhile, the phenol foam is uniformly mixed with the phenol resin including the flame retardant, the foam cell structure is not easily destroyed, and uniform foaming can provide uniform physical properties. In addition, the first flame retardant acts as a filler in the phenol foam and, together with the second flame retardant, provides structural stability to the phenol foam and, at the same time, provides excellent compressive strength and flexural failure load within the above range.

Specifically, the phenol foam may have a compressive strength of about 80 kPa to about 300 kPa according to KS M ISO 844. For example, about 150 kPa to about 230 kPa. It could be.

The above phenol foam may have a flexural failure load (N) of about 15 N to about 50 N, which is the maximum load (N) until the specimen is judged, at a support spacing of 200 mm and a load concentration speed of 50 mm/min on a specimen of 250 mm (L) X 100 mm (W) X 20 mm (T) in size according to KS M ISO 4898. For example, it may be about 20 N to about 50 N.

And, the phenol foam may have an average value of a dimensional change rate of 0% to 1.0% according to the following Equation 4. For example, the phenol foam may have an average dimensional change rate of about 0% to about 0.8% or about 0% to about 0.6%.

[Formula 4]

Dimensional change rate (%) = (initial length (a) - final length (a')) / initial length (a) X 100

In the above equation 4, the initial length (a) is the length of each line at n equal points in the length (L) and width (W) directions of the phenol foam, and the later length (a') means the later length (a') of each line at the points after the phenol foam is left in an oven at 70° C. for 48 hours. At this time, n may be 2 to 5. n may be 3.

The above phenol foam has a dimensional change rate within the above range including the flame retardant, and thus can be seen to have excellent dimensional stability. Accordingly, the above phenol foam exhibits excellent thermal conductivity, so that long-term thermal insulation can be more effectively improved, and when applied to a given product, processability and workability can be more excellent.

And, the phenol foam can exhibit excellent flame retardancy with an oxygen index of about 32% or higher according to KS M ISO 4589-2. Specifically, the phenol foam can be about 32% to about 60%, about 36% to about 60%, or about 43% to about 60%. Since the phenol foam has an oxygen index of the above range, it may not easily combust in case of fire, and thus, it may be easy to secure evacuation time, etc.

Another embodiment of the present invention comprises the steps of: preparing a flame retardant composition including a subject including a phenolic resin, a curing agent, a foaming agent, and a first flame retardant; stirring the subject, the curing agent, the foaming agent, and the flame retardant composition to prepare a foam composition; and foaming and curing the foam composition; wherein the first flame retardant is phosphorus, and the present invention provides a method for producing a phenolic foam having a mass reduction rate (W1) of 5% to 35% after applying 50 kW radiant heat according to KS F ISO 5660-1 to the foam for 5 minutes.

As described above, by the above manufacturing method, it is possible to manufacture the phenol foam having excellent flame retardancy by satisfying Equations 1 and 2 with a low mass reduction rate during combustion and preventing the propagation and spread of flames, and at the same time excellent heat insulation, excellent compressive strength, dimensional stability, and other physical properties. Matters relating to the phenol resin, curing agent, foaming agent, and flame retardant are as described above, except as specifically described below.

First, a flame retardant composition is prepared, which comprises a subject matter including a phenolic resin, a curing agent, a blowing agent, and a first flame retardant. The subject matter may comprise about 1 part by weight to about 5 parts by weight of a surfactant and about 3 parts by weight to about 10 parts by weight of urea, relative to 100 parts by weight of the phenolic resin.

The first flame retardant includes a solid material such as phosphorus. And, the flame retardant composition may further include a second flame retardant to include a composite flame retardant. The composite flame retardant may include a solid material such as phosphorus, a pentaerythritol-based compound, melamine cyanurate, and a combination thereof. At this time, the composite flame retardant is included in the foam composition in the form of a flame retardant composition mixed with an organic solvent, so that it has appropriate flowability and is easily introduced into the production process and can be uniformly mixed with the phenol-based resin. For example, the flame retardant: organic solvent may be mixed in a weight ratio of about 2:1 to about 1:2 and included in the flame retardant composition, and the flame retardancy improving effect of the flame retardant may not be reduced when mixed in the content ratio within the above range.

The above organic solvent may be a low viscosity organic solvent selected from the group consisting of polyols, surfactants, polyethylene glycol, ethylene glycol, phosphate compounds, and combinations thereof. The phosphate compound may be, for example, tris-(1-chloro-2-propyl) phosphate (TCPP), tris-(2-chloroethyl) phosphate (TCEP), triethyl phosphate (TEP), etc.

The organic solvent may be added in an amount ranging from about 1 part by weight to about 15 parts by weight per 100 parts by weight of the phenolic resin. If the content of the organic solvent exceeds the above range, a problem of reduced insulation may occur.

For example, the organic solvent may be a mixed organic solvent of one first organic solvent selected from the group consisting of TCPP, TCEP, TEP, and combinations thereof, and one second organic solvent selected from the group consisting of polyols, surfactants, polyethylene glycol, ethylene glycol, and combinations thereof.

At this time, at 20℃, the viscosity difference (△V=|V1 - V2|) between the viscosity (V1) of the phenolic resin and the viscosity (V2) of the flame retardant composition may be about 30,000 cps or less or about 20,000 cps or less. It may be about 0 or more and about 10,000 cps or less. By adjusting the viscosity difference (△V) between the viscosity (V1) of the phenolic resin and the viscosity (V2) of the flame retardant composition within the above range, the flame retardant including the solid substance may not be precipitated during the foam manufacturing process, but may be uniformly and well mixed with the phenolic resin, thereby exhibiting improved flame retardancy, excellent insulation, and excellent physical properties.

Specifically, when the viscosity difference (△V) exceeds the above range, uniform mixing and foaming of the flame retardant and the phenolic resin, etc. may become difficult, and thus the physical properties of the phenolic foam may deteriorate. In addition, as the viscosity of the foam composition including the phenolic resin and the flame retardant composition, etc. increases overall, the torque of the stirring mixer is increased, and the temperature of the foam composition rapidly increases, so that the amount of volatile foaming agent may increase before the foam is hardened, and thus the insulation may deteriorate.

And, the viscosity (V1) of the phenol resin can be about 10,000 cps to about 80,000 cps, about 10,000 cps to about 50,000 cps, or about 20,000 cps to about 50,000 cps at 20°C. By adjusting the viscosity difference (△V) and the viscosity (V1) of the phenol resin within the above range, the curing reaction speed of the phenol resin in which the flame retardant is dispersed can be appropriately controlled. Accordingly, a phenol foam that is structurally stable and has an appropriate crosslinking structure can be formed, so that the phenol foam can maintain excellent thermal insulation at a certain level along with improved flame retardancy and exhibit excellent physical properties such as excellent compressive strength.

The foaming agent may be included in an amount of about 5 parts by weight to about 15 parts by weight based on about 100 parts by weight of the phenolic resin. By including the foaming agent in an amount within the above range, the foam composition including the flame retardant dispersed in the phenolic resin can be uniformly foamed at an appropriate foaming pressure during the foaming process, thereby forming a phenolic foam having improved properties such as flame retardancy, heat insulation, and compressive strength. For example, when the amount of the foaming agent exceeds the above range, the foam cells may be destroyed, thereby lowering the heat insulation, increasing the dimensional change rate of the foam, and lowering the compressive strength.

And, the hardener may be included in an amount of about 15 to 25 parts by weight based on 100 parts by weight of the phenol resin. The hardener refers to a mixture of a substance such as toluenesulfonic acid mixed with a solvent. By including the hardener in an amount within the above range, the balance of foaming and curing can be appropriately controlled in a composition including a composite flame retardant, and thus, excellent flame retardancy, heat insulation, and excellent compressive strength can be imparted.

And, the method for producing the phenol foam includes a step of producing a foam composition by stirring the subject, the curing agent, the foaming agent, and the flame retardant composition. The method for producing the phenol foam can mix and stir the flame retardant composition including the flame retardant separately from the subject including the phenol resin. Accordingly, the viscosity of the subject including the phenol resin can be prevented from rapidly increasing, and the phenol foam having the above-described physical properties can be easily produced.

And, the method for manufacturing the phenol foam includes a step of foaming the foam composition. The phenol foam can be foamed and cured under temperature conditions of, for example, about 50° C. to about 90° C. In addition, the foaming and curing can be performed for a time of about 2 minutes to about 20 minutes, but is not limited thereto, and can be appropriately varied depending on the purpose and use of the invention.

Another embodiment of the present invention provides an insulation comprising the phenolic foam.

The above phenol foam can be applied, for example, as a building insulation material, and thus can simultaneously satisfy excellent insulation properties required as a building insulation material and significantly improved flame retardancy. In addition, it can have excellent compressive strength, dimensional stability, and a high oxygen index.

The above-mentioned building insulation material may further include a facing material on one or both sides of the phenolic foam, for example, and the facing material may include aluminum to further improve flame retardancy.

(Example)

Example 1:

A flame retardant composition was prepared by mixing 100 parts by weight of a resol resin having a viscosity of 30,000 cps at 20°C, 2.5 parts by weight of an ethoxylated castor oil surfactant, and 3.5 parts by weight of powdered urea, toluenesulfonic acid as a curing agent, and cyclopentane as a blowing agent, and mixing castor oil surfactant: polyester polyol in a weight ratio of 1:1 in a solvent.

Then, for 100 parts by weight of the resol resin, 16 parts by weight of a mixture of 80 parts by weight of toluenesulfonic acid, 15 parts by weight of ethylene glycol, and 5 parts by weight of water, and 8 parts by weight of cyclopentane were supplied to a stirrer through a pipe and stirred to prepare a foam composition.

Then, the stirred foam composition was fed into a ketupil operating at a speed of 5 m/min to produce a phenol foam having a density of 45 kg/m ³ . The temperature of the ketupil was 70°C, and the thickness was 50 mm.

At this time, the content of the red pigment and the content of the organic solvent included in the flame retardant composition were adjusted so that, at 20°C, the viscosity difference (△V=|V1 - V2|) between the viscosity of the resole resin (V1) and the viscosity of the flame retardant composition (V2) was within 10,000 cps. The viscosity was measured using a Brookfield viscometer (Brookfield, DV3T Rheometer, #63 spindle).

And, finally, the phenol foam was made to contain 9 parts by weight per 100 parts by weight of the phenol foam.

Example 2:

Instead of a flame retardant composition mixed with mercury, a composite flame retardant of mercury and monopentaerythritol was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of mercury and 3 parts by weight of monopentaerythritol were ultimately included relative to 100 parts by weight of the phenol foam.

Example 3:

Instead of a flame retardant composition mixed with cyanurate, a composite flame retardant of cyanurate and melamine cyanurate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of cyanurate and 3 parts by weight of melamine cyanurate were ultimately included relative to 100 parts by weight of the phenol foam.

Example 4:

Instead of a flame retardant composition mixed with mercury, a composite flame retardant of mercury and triethyl phosphate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, the content of the composite flame retardant was adjusted so that 6 parts by weight of mercury and 3 parts by weight of triethyl phosphate were ultimately included relative to 100 parts by weight of the phenol foam, except that a phenol foam was manufactured in the same manner as in Example 1.

Example 5:

Instead of a flame retardant composition mixed with mercury, a composite flame retardant of mercury, monopentaerythritol, and melamine cyanurate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, the content of the composite flame retardant was adjusted so that 6 parts by weight of mercury, 1.5 parts by weight of monopentaerythritol, and 1.5 parts by weight of melamine cyanurate were ultimately contained relative to 100 parts by weight of the phenol foam, except that a phenol foam was manufactured in the same manner as in Example 1.

Example 6:

Instead of a flame retardant composition mixed with cyanurate, a composite flame retardant of cyanurate, melamine cyanurate, and triethyl phosphate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, the content of the composite flame retardant was adjusted so that 6 parts by weight of cyanurate, 1.5 parts by weight of melamine cyanurate, and 1.5 parts by weight of triethyl phosphate were ultimately contained relative to 100 parts by weight of the phenol foam, except that a phenol foam was manufactured in the same manner as in Example 1.

Example 7:

Instead of a flame retardant composition mixed with mercury, a composite flame retardant of mercury, monopentaerythritol, and triethyl phosphate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, the content of the composite flame retardant was adjusted so that 6 parts by weight of mercury, 1.5 parts by weight of monopentaerythritol, and 1.5 parts by weight of triethyl phosphate were ultimately contained relative to 100 parts by weight of the phenol foam, except that a phenol foam was manufactured in the same manner as in Example 1.

Example 8:

Instead of a flame retardant composition mixed with mercury, a composite flame retardant of mercury, monopentaerythritol, melamine cyanurate, and triethyl phosphate was mixed in a solvent containing castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. At this time, the content of the composite flame retardant was adjusted so that ultimately 6 parts by weight of mercury, 1 part by weight of monopentaerythritol, 1 part by weight of melamine cyanurate, and 1 part by weight of triethyl phosphate were contained relative to 100 parts by weight of the phenol foam, except that a phenol foam was manufactured in the same manner as in Example 1.

Comparative Example 1:

Instead of a flame retardant composition mixed with a phenol, a flame retardant composition was prepared by mixing ammonium polyphosphate in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the ammonium polyphosphate was adjusted so that 9 parts by weight of ammonium polyphosphate was included relative to 100 parts by weight of the phenol foam.

Comparative Example 2:

Instead of a flame retardant composition mixed with the enemy, a flame retardant composition was prepared by mixing expanded graphite in a solvent containing castor oil surfactant and polyester polyol in a weight ratio of 1:1. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the expanded graphite was adjusted so that 9 parts by weight of the expanded graphite was included relative to 100 parts by weight of the phenol foam.

Comparative Example 3:

Instead of a flame retardant composition mixed with graphite, a composite flame retardant of expanded graphite and tris-(1-chloro-2-propyl)phosphate (TCPP) was mixed in a solvent containing castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of expanded graphite and 3 parts by weight of tris(1-chloro-2-propyl)phosphate were ultimately included based on 100 parts by weight of the phenol foam.

Comparative Example 4:

Instead of a flame retardant composition mixed with melamine cyanurate, a flame retardant composition was prepared by mixing melamine cyanurate in a solvent containing castor oil surfactant and polyester polyol in a weight ratio of 1:1. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the melamine cyanurate was adjusted so that 9 parts by weight of melamine cyanurate was included relative to 100 parts by weight of the phenol foam.

Comparative Example 5:

Instead of a flame retardant composition mixed with a phenol, a flame retardant composition was prepared by mixing monopentaerythritol in a solvent containing castor oil surfactant and polyester polyol in a weight ratio of 1:1. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the monopentaerythritol was adjusted so that 9 parts by weight of monopentaerythritol was included per 100 parts by weight of the phenol foam.

Comparative Example 6:

Instead of a flame retardant composition mixed with the enemy, a flame retardant composition was prepared by mixing triethyl phosphate in a solvent in which castor oil surfactant: polyester polyol were mixed in a weight ratio of 1:1. At this time, a phenol foam was manufactured in the same manner as in Example 1, except that the content of the triethyl phosphate was adjusted so that 9 parts by weight of triethyl phosphate was included relative to 100 parts by weight of the phenol foam.

Comparative Example 7:

Instead of a flame retardant composition mixed with the enemy, a composite flame retardant of ammonium polyphosphate and melamine cyanurate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of ammonium polyphosphate and 3 parts by weight of melamine cyanurate were ultimately included based on 100 parts by weight of the phenol foam.

Comparative Example 8:

Instead of a flame retardant composition mixed with the enemy, a composite flame retardant of ammonium polyphosphate and monopentaerythritol was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of ammonium polyphosphate and 3 parts by weight of monopentaerythritol were ultimately included based on 100 parts by weight of the phenol foam.

Comparative Example 9:

Instead of a flame retardant composition mixed with the enemy, a composite flame retardant of ammonium polyphosphate and triethyl phosphate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of ammonium polyphosphate and 3 parts by weight of triethyl phosphate were ultimately included based on 100 parts by weight of the phenol foam.

Comparative Example 10:

Instead of a flame retardant composition mixed with the enemy, a composite flame retardant of monopentaerythritol and melamine cyanurate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of monopentaerythritol and 3 parts by weight of melamine cyanurate were ultimately contained relative to 100 parts by weight of the phenol foam.

Comparative Example 11:

Instead of a flame retardant composition mixed with the enemy, a composite flame retardant of triethyl phosphate and melamine cyanurate was mixed in a solvent containing a castor oil surfactant and polyester polyol in a weight ratio of 1:1 to prepare a flame retardant composition. A phenol foam was manufactured in the same manner as in Example 1, except that the content of the composite flame retardant was adjusted so that 6 parts by weight of triethyl phosphate and 3 parts by weight of melamine cyanurate were ultimately included based on 100 parts by weight of the phenol foam.

Comparative Example 12:

A subject was prepared by mixing 2 parts by weight of a silicone-based surfactant, 0.8 parts by weight of an amine-based catalyst, and phosphoric acid for 100 parts by weight of a polyol having an average OH value of 350.

Then, for 100 parts by weight of the polyol, 115 parts by weight of methylene diphenyl diisocyanate and 12 parts by weight of cyclopentane were supplied to a stirrer through a pipe and stirred to prepare a foam composition.

Then, the stirred foam composition was fed into a caterpillar operating at a speed of 5 m/min to produce a urethane foam having a density of 45 kg/m ³ . At this time, the temperature of the caterpillar was 70°C and the thickness was 50 mm.

Finally, the urethane foam was made to contain 9 parts by weight of the polymer based on 100 parts by weight of the urethane foam.

evaluation

Experimental Example 1: Mass Reduction Rate (W1)

The foams of the above examples and comparative examples were manufactured into specimens measuring 100 mm (L) X 100 mm (W) X 50 mm (T) using a grizzly band saw.

After measuring the initial mass (Wi) of the above specimen, the remaining five sides except the heating side are wrapped with aluminum foil, the specimen is placed in a cone calorimeter holder with the zero point set, and the weight of the aluminum foil (W _Al ) is confirmed through the mass of the specimen including the foil displayed on the device.

According to KS F ISO 5660-1, the temperature of the cone heater was set to 700℃ with 50kW/ ^m2 of radiant heat, the blower speed was 24L/min, and the oxygen concentration was 20.950%, and the mass of the specimen was measured for 10 minutes.

After the test was completed, the mass after 5 minutes was automatically recorded, i.e., the later mass of the phenol foam containing the aluminum foil burned by applying the radiant heat for 5 minutes, was determined, and the final later mass (Wf) of the specimen was obtained by subtracting the initially obtained weight of the aluminum foil (W _Al ).

And, the mass reduction rate (W1(%) = [Wi-Wf]/Wi X 100) compared to the initial mass is shown in Table 1 below.

Experimental Example 2: Mass Reduction Rate (W2)

The initial mass (Wi) and the later mass (Wf') were measured in the same manner as in Experimental Example 1, except that the later mass 10 minutes after measurement in Experimental Example 1 was obtained.

And, the mass reduction rate (W2, %) compared to the initial mass ([Wi-Wf']/Wi X 100) is shown in Table 1 below.

Experimental Example 3: Initial thermal conductivity ( W/m K )

The foams of the examples and comparative examples were cut into 50 mm thick and 300 mm × 300 mm in size to prepare test pieces, and the test pieces were dried at 70°C for 12 hours to perform pretreatment. Then, the thermal conductivity of the test pieces was measured at an average temperature of 20°C using a thermal conductivity device HC-074-300 (EKO Corporation) according to the measurement conditions of KS L 9016 (plate heat flow meter measurement method), and the results are shown in Table 2 below.

Experimental Example 4: Long-term thermal conductivity ( W/m K )

The foams of the examples and comparative examples were cut to a thickness of 50 mm and a size of 300 mm × 300 mm to prepare test pieces, and the test pieces were dried at 70°C for 7 days and then at 110°C for 14 days in accordance with EN13166. The thermal conductivity was then measured using a thermal conductivity device HC-074-300 (EKO Corporation) at an average temperature of 20°C, and the results are shown in Table 2 below.

Experimental Example 5: THR 300s ( MJ/㎡ )

The phenol foam of the above examples and comparative examples was manufactured into specimens measuring 100 mm (L) X 100 mm (W) X 50 mm (T) using a grizzly band saw.

And, the measurement conditions of KS F ISO 5660-1 were set as follows. The temperature of the cone heater was set to 700℃ by setting 50kW/ ^m2 radiant heat, the blower speed was 24L/min, and the oxygen concentration was started at 20.950%. And, using a cone calorimeter measuring device (Festek International), 50kW/ ^m2 radiant heat was applied to the specimen for 5 minutes, and the total heat release (THR300) was measured. And, the results are shown in Table 2 below.

Experimental Example 6: THR 600s ( MJ/㎡ )

The measurement was performed in the same manner as in Experimental Example 3, except that 50 kW/m ² radiant heat was applied to the specimen for 10 minutes using a cone calorimeter (Festek International) and the total heat release (THR600) was measured. The results are shown in Table 2 below.

Experimental Example 7: Independent bubble ratio (%)

Each foam of Examples and Comparative Examples was cut into 2.5 cm (L) X 2.5 cm (W) X 2.5 cm (T) to prepare a specimen. Then, the independent cell rate measuring device (Quantachrome, ULTRAPYC 1200e) was used to measure the foam according to the KS M ISO 4590 measuring method, and the results are shown in Table 2 below.

Experimental Example 8: Compressive strength (kPa)

The phenol resin foams of the examples and comparative examples were prepared as specimens of 50 mm (L) X 50 mm (W) X 50 mm (T), and the specimens were placed between the wide plates of a Lloyd instrument LF Plus Universal Testing Machine, and the UTM equipment was set to a speed of 10% mm/min of the specimen thickness, and the compressive strength test was started, and the strength at the first compressive yield point appearing while the thickness was decreasing was recorded. The compressive strength was measured by the method of the KS M ISO 844 standard, and the results are shown in Table 2 below.

Experimental Example 9: Dimensional Stability (%)

Figure 1 is a schematic diagram briefly illustrating a method for measuring the dimensional stability of a foam of the present invention.

The phenol foams of the examples and comparative examples were prepared as specimens with a size of 100 mm (L) X 100 mm (W) X 50 mm (T). Then, as shown in Fig. 1, lines were drawn at n (n = 3) equal points in the length (L) and width (W) directions of the specimen, and the initial length (a) of each line was measured at 25°C.

Then, after leaving the above specimen in a 70℃ oven for 48 hours, the later length (a') of each point was measured, and the dimensional change rate (%) from the initial dimension was measured using Equation 4 below, and the average value is recorded in Table 2. The dimensional stability was measured using the method of KS M ISO 2796.

[Formula 4]

Dimensional change rate (%) = (Initial length (a) - Final length (a')) / Initial length (a) X 100

Experimental Example 10: Oxygen Index (LOI)

The minimum concentration of oxygen required to sustain combustion of the foams of the examples and comparative examples under the test conditions specified in the KS M ISO 4589-2 standard was measured, and the results are shown in Table 2 below. The test results are given as the volume percentage of oxygen in the oxygen and nitrogen mixture injected at a temperature of 23±2℃.

Experimental Example 11: Flexural failure load (N)

The foams of the examples and comparative examples were prepared as specimens with the size of 250 mm (L) × 100 mm (W) × 20 mm (T), and the maximum load (N) until the specimens were broken was measured at a support spacing of 200 mm and a load concentration speed of 50 mm/min according to KS M ISO 4898, and the results are shown in Table 2 below.

W1 W2 Regarding equation 1, the relationship between W1 and W2 (=W2-W1) The value of [Formula 2]
((W2-W1)/W1) Example 1 25.8 42.3 16.5 0.64 Example 2 24.5 40.4 15.9 0.65 Example 3 21.2 36.1 14.9 0.70 Example 4 23.4 38.6 15.2 0.65 Example 5 22.8 36.8 14 0.61 Example 6 21.4 35.9 14.5 0.68 Example 7 22.6 37.8 15.2 0.67 Example 8 19.5 32.4 12.9 0.66 Comparative Example 1 31.1 55.8 24.7 0.79 Comparative Example 2 34.2 60.5 26.3 0.77 Comparative Example 3 33.7 59.3 25.6 0.76 Comparative Example 4 34.9 62.1 27.2 0.78 Comparative Example 5 38.6 68.1 29.5 0.76 Comparative Example 6 36.1 67.2 31.1 0.86 Comparative Example 7 30.8 54.3 23.5 0.76 Comparative Example 8 31.3 55.8 24.5 0.78 Comparative Example 9 32.4 56.9 24.5 0.76 Comparative Example 10 35.8 66.7 30.9 0.86 Comparative Example 11 36.9 67.1 30.2 0.82 Comparative Example 12 40.5 72.9 32.4 0.80

beginning
Thermal Conductivity
(W/m K) long time
Thermal Conductivity
(W/m K) THR _300s
(MJ/㎡) THR ^600s
(MJ/㎡) independence
Foaming rate
(%) Compressive strength
(kPa) size
Stability
(%) Oxygen Index (LOI) winding
Breaking load
(N) Example 1 0.01998 0.02276 4.4 7.9 87.4 166.3 0.55 43.8 22.6 Example 2 0.01911 0.01989 4.6 7.4 90.4 186.3 0.45 44.2 26.4 Example 3 0.01989 0.02234 3.6 6.9 86.9 174.4 0.52 45.2 23.6 Example 4 0.01953 0.02172 4.5 7.3 89.1 168.5 0.44 43.4 23.9 Example 5 0.01977 0.02037 3.8 6.2 88.4 184.2 0.53 46.4 27.3 Example 6 0.01942 0.02146 3.4 6 87.6 194.2 0.48 47.2 26.2 Example 7 0.01916 0.02088 4.2 6.4 90.2 182.6 0.41 47.6 29.4 Example 8 0.01924 0.01986 3 5.7 90.6 199.2 0.40 48.0 29.5 Comparative Example 1 0.03159 0.03369 7.1 10.4 10.5 112.0 1.20 41.2 18.5 Comparative Example 2 0.02029 0.02351 11.5 19.8 90.5 143.2 0.85 33.8 20.2 Comparative Example 3 0.02134 0.02333 12.6 20.1 88.4 138.5 0.88 32.6 19.4 Comparative Example 4 0.02362 0.02847 11.9 19.4 78.2 124.8 1.11 35.6 21.2 Comparative Example 5 0.01945 0.02277 14.8 24.6 89.4 156.5 0.94 31.0 23.4 Comparative Example 6 0.02159 0.02442 13.2 22.5 81.5 135.2 0.77 31.4 18.7 Comparative Example 7 0.03154 0.03324 6.2 9.7 8.5 105.9 1.22 41.4 17.4 Comparative Example 8 0.02994 0.03245 6.6 9.9 10.4 111.5 1.07 40.5 20.8 Comparative Example 9 0.03328 0.03452 7.8 11.1 7.6 98.4 1.17 39.7 19.5 Comparative Example 10 0.02048 0.02268 13.6 21.2 89.4 142.5 0.85 32.2 23.5 Comparative Example 11 0.02311 0.02414 12.8 19.9 83.2 128.4 0.91 33.0 19.4 Comparative Example 12 0.02424 0.02914 10.1 16.1 79.6 137.3 0.63 25.4 23.5

As shown in Table 2 above, unlike the comparative examples, the phenol foam of the examples satisfying Equations 1 and 2 exhibits excellent flame retardancy, such as low total heat release and high oxygen index, and also exhibits excellent thermal conductivity. In addition, it can be seen that the phenol foam of the examples also has excellent flexural fracture load.

Although the present invention has been described as above, it is obvious that the present invention is not limited to the contents disclosed in this specification, and various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, even if the operation and effect according to the configuration of the present invention was not explicitly described while explaining the embodiments of the present invention, it is natural that the effects that can be predicted by the configuration should also be recognized.

Claims (26)

A phenolic foam comprising a composite flame retardant comprising a phenolic resin, a curing agent, a foaming agent, and a first flame retardant and a second flame retardant,
The first flame retardant is phosphorus,
The second flame retardant comprises at least one selected from the group consisting of pentaerythritol-based compounds, melamine cyanurate, trialkyl phosphates, and combinations thereof.
The mass reduction rate (W1, %) after applying 50 kW/m ² radiant heat to the foam for 5 minutes according to KS F ISO 5660-1 is 5% to 35%,
The mass reduction rate (W2, %) after applying 50 kW/m ² radiant heat for 10 minutes according to KS F ISO 5660-1 satisfies the following equation 2 in the relationship with the mass reduction rate (W1, %) after applying the above for 5 minutes.
The thermal conductivity measured at an average temperature of 20℃ according to KS L 9016 is 0.016 W/m K to 0.023 W/m K.
Phenolic foam.

[Formula 2]
0.25 < (W2-W1)/W1 < 0.75
In the first paragraph,
The mass reduction rate (W2, %) after applying 50kW/ ^m2 radiant heat to the foam for 10 minutes according to KS F ISO 5660-1 satisfies the following equation 1 in relation to the mass reduction rate (W1, %) after applying the heat for 5 minutes.
Phenolic foam.

[Formula 1]
W1 + 3.0% < W2 < W1 + 20.0%
delete In the first paragraph,
Oxygen index of 32% or higher according to KS M ISO 4589-2
Phenolic foam.
In the first paragraph,
The independent foaming rate is 75% to 98%.
Phenolic foam.
In the first paragraph,
The above-mentioned foaming agent comprises an aliphatic hydrocarbon having 1 to 8 carbon atoms.
Phenolic foam.
In the first paragraph,
The first flame retardant is contained in an amount of 0.9 to 15 parts by weight relative to 100 parts by weight of the phenol foam.
Phenolic foam.
In the first paragraph,
The above composite flame retardant is included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the above phenol foam.
Phenolic foam.
In the first paragraph,
The second flame retardant is 0.1 part by weight based on 100 parts by weight of the phenol foam. Containing a content of 7 parts by weight
Phenolic foam.
In the first paragraph,
The weight ratio of the first flame retardant to the second flame retardant is 1:0.05 to 1:1.2.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises a phosphorus and pentaerythritol compound,
The weight ratio of the above-mentioned pentaerythritol compound is 1:0.05 to 1:0.6.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises a phosphorus and melamine cyanurate compound,
The weight ratio of the above-mentioned melamine cyanurate compound is 1:0.05 to 1:0.8.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises phosphorus and trialkyl phosphate,
The weight ratio of the above trialkyl phosphate to the above trialkyl phosphate is 1:0.05 to 1:0.8.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises a phosphorus, pentaerythritol-based compound and melamine cyanurate.
The composition comprises 1 to 50 parts by weight of the pentaerythritol compound and 1 to 80 parts by weight of the melamine cyanurate, relative to 100 parts by weight of the above-mentioned phosphorus.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises phosphorus, melamine cyanurate and trialkyl phosphate,
The composition comprises 1 to 80 parts by weight of the melamine cyanurate and 1 to 80 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the above-mentioned phosphorus.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises a phosphorus, pentaerythritol-based compound and a trialkyl phosphate,
The pentaerythritol compound is included in an amount of 1 to 50 parts by weight, and the trialkyl phosphate is included in an amount of 1 to 80 parts by weight, relative to 100 parts by weight of the above-mentioned phosphorus.
Phenolic foam.
In the first paragraph,
The above composite flame retardant comprises phosphorus, pentaerythritol-based compounds, melamine cyanurate and trialkyl phosphate.
The composition comprises 1 to 30 parts by weight of the pentaerythritol compound, 1 to 50 parts by weight of the melamine cyanurate, and 1 to 60 parts by weight of the trialkyl phosphate, relative to 100 parts by weight of the above-mentioned phosphorus.
Phenolic foam.
In the first paragraph,
The total heat release (THR300s) for 5 minutes by a cone calorimeter according to KS F ISO 5660-1 is 1.0 MJ/㎡ to 12 MJ/㎡.
Phenolic foam.
In the first paragraph,
According to EN13166, after drying at 70°C for 7 days and then at 110°C for 14 days, the thermal conductivity measured at an average temperature of 20°C is between 0.017 W/m K and 0.029 W/m K.
Phenolic foam.
In the first paragraph,
Compressive strength of 80kPa to 300kPa according to KS M ISO 844
Phenolic foam.
In the first paragraph,
Total heat release (THR600s) for 10 minutes by a cone calorimeter according to KS F ISO 5660-1 is 2.0 MJ/㎡ to 15 MJ/㎡
Phenolic foam.
In the first paragraph,
According to KS M ISO 4898, the maximum load (N) until the specimen is judged, the flexural failure load (N), is 15 N to 50 N, at a support spacing of 200 mm and a load concentration speed of 50 mm/min on a specimen of 250 mm (L) X 100 mm (W) X 20 mm (T) in size.
Phenolic foam.
In the first paragraph,
The average value of the dimensional change rate according to the following equation 4 is 0% to 1.0%.
Phenolic foam:

[Formula 4]
Dimensional change rate (%) = (initial length (a) - final length (a')) / initial length (a) X 100

In the above equation 4, the initial length (a) is the length of each line at n points that are equal in the length (L) and width (W) directions of the phenol foam, and the later length (a') means the later length (a') of each line at the points after the phenol foam is left in an oven at 70° C. for 48 hours. (n is 2 to 5)
A step of preparing a flame retardant composition comprising a subject matter including a phenolic resin, a curing agent, a blowing agent, and a composite flame retardant including a first flame retardant and a second flame retardant;
A step of preparing a foam composition by stirring the above-mentioned subject matter, curing agent, foaming agent and flame retardant composition; and
A step of foaming and curing the foam composition is included;
The first flame retardant is phosphorus,
The second flame retardant comprises at least one selected from the group consisting of pentaerythritol-based compounds, melamine cyanurate, trialkyl phosphates, and combinations thereof.
The mass reduction rate (W1) after applying 50kW radiant heat to the foam for 5 minutes according to KS F ISO 5660-1 is 5% to 35%,
The mass reduction rate (W2, %) after applying 50 kW/m ² radiant heat for 10 minutes according to KS F ISO 5660-1 satisfies the following equation 2 in the relationship with the mass reduction rate (W1, %) after applying the above for 5 minutes.
The thermal conductivity measured at an average temperature of 20℃ according to KS L 9016 is 0.016 W/m K to 0.023 W/m K.
Method for producing phenol foam.

[Formula 2]
0.25 < (W2-W1)/W1 < 0.75
In Article 24,
At 20℃, the viscosity difference (△V=|V1 - V2|) between the viscosity (V1) of the phenolic resin and the viscosity (V2) of the flame retardant composition is 30,000 cps or less.
Method for producing phenol foam.
An insulating material comprising a phenol foam according to any one of claims 1, 2, and 4 to 23.

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