KR102369665B1 - Phenol resin foam and method for manufacturing the same - Google Patents

Abstract

It is a thermosetting product of a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent, and the nucleating agent includes one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof. , a phenolic resin foam with a standard deviation of the mean diameter of the foam cells of 8.5 to 12 is provided.

Description

Phenolic resin foam and manufacturing method thereof

The present invention relates to a phenolic resin foam and an insulating material comprising the same.

Thermosetting foams can be mainly used as insulation materials for various buildings, warehouses, refrigerators, and the like. At this time, the insulator is a material used to increase heating and cooling efficiency by blocking or reducing heat exchange between the inside and outside of a building. In addition, the thermosetting foam used as a thermal insulator may have a foamed cell structure filled with foaming gas to improve thermal insulation performance.

On the other hand, in the case of a chlorine-containing blowing agent such as chlorofluorocarbon (CFC), it is effective as an insulator because of its high stability and low thermal conductivity, but its use is limited due to the property of destroying the ozone layer. Accordingly, a foam that exhibits excellent thermal insulation performance without destroying the ozone layer is practically required.

An object of the present invention is to provide a phenolic resin foam having zero ozone depletion potential (ODP), having small and uniformly-diameter foamed cells, and implementing excellent long-term thermal conductivity and dimensional stability.

It is also an object of the present invention to provide a method for producing the phenolic resin foam.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

A thermosetting product of a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent according to the present invention, wherein the nucleating agent is selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof one, wherein the standard deviation of the average diameter of the foam cells is 8.5 to 12.

In addition, preparing a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent according to the present invention; And applying heat to the foamable composition to foam and harden; including, wherein the nucleating agent comprises one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof, The standard deviation of the average diameter of the foam cells can provide a method for producing a phenolic resin foam of 8.5 to 12.

The phenolic resin foam of the present invention has zero ozone depletion potential (ODP), has foam cells of uniform diameter, and can exhibit excellent long-term thermal conductivity and dimensional stability at the same time.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 shows a graph in which the foam cell diameter of the foam of Example 1 was measured using an electron microscope (hitachi, FE-SEM), and measured and classified within the range of about 20 μm to about 230 μm for every 20 μm.
FIG. 2 shows a graph in which the foam cell diameter of the foam of Comparative Example 1 was measured using an electron microscope (hitachi, FE-SEM), and measured and classified within the range of about 20 μm to about 230 μm for every 20 μm.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

One embodiment of the present invention is a thermosetting product of a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent, wherein the nucleating agent is hydrofluoroalkane, hydrofluoroether, and a combination thereof and one selected from the group, wherein the standard deviation of the mean diameter of the foam cells is 8.5 to 12.

In the case of a chlorine-containing blowing agent such as isopropyl chloride, the thermal conductivity is low, so it may be effective as a heat insulator. However, its use is limited due to its depleting properties of the ozone layer. Accordingly, a blowing agent such as hydrofluoroolefin may be used, but the cost is too high, which is uneconomical. And, when a hydrocarbon-based foaming agent is used, the problem of ozone layer depletion can be solved, but the foaming gas trapping power is lowered, the foam is contracted, dimensional stability is lowered, thermal conductivity is increased, and thermal insulation properties are lowered. Occurs. That is, there is a problem in that it is difficult to have an ozone depletion potential (ODP) of zero and at the same time have desired physical properties.

The phenolic resin foam can economically exhibit zero ozone depletion index (ODP), and exhibit excellent long-term thermal conductivity and dimensional stability at the same time.

The phenolic resin foam may not include isopropylchloride and hydrofluoroolefin. The phenolic resin foam does not contain isopropyl chloride, which destroys the ozone layer, and hydrofluoroolefin, which is expensive and expensive, and has zero ozone depletion index including a hydrocarbon-based foaming agent, and more economically excellent long-term thermal conductivity and dimensions stability can be exhibited at the same time.

Specifically, the hydrocarbon-based blowing agent is n-butane, isobutane, n-pentane, isopentane, cyclopentane, n-hexane (n- hexane) and one compound selected from the group consisting of combinations thereof. More specifically, the phenolic resin foam may contain cyclopentane, and by including the hydrocarbon-based foaming agent, it suppresses volatilization of the foaming gas, and the loss rate of the foaming gas during foaming is small, so that the foam can be produced more stably. can

The phenolic resin foam comprising the phenolic resin and the hydrocarbon-based foaming agent includes a hydrophobic nucleating agent comprising one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof. , it has uniformly foamed cells of appropriate diameter, and can exhibit excellent long-term thermal conductivity and dimensional stability at the same time. The phenolic resin foam does not contain a nucleating agent such as a perfluoroalkane having a high global warming potential (GWP).

The phenol resin foam is a cured product by physical foaming, and the foaming gas is dissolved in a polymer resin to form a single phase, and then the foam is formed as the foaming agent is separated from the polymer resin due to an increase in thermodynamic instability.

The phenolic resin foam includes the nucleating agent in the phenolic resin and the hydrocarbon-based foaming agent, so that the diameter of the foamed cells can be made uniform to an appropriate size, and the stability of the walls formed between the foamed cells can be increased. For example, as a phenol-based resin exhibits hydrophilicity, when another nucleating agent, for example, a hydrophilic nucleating agent is used, the nucleating agent may be dissolved in the phenol-based resin to rather hinder the formation of foam cells. Accordingly, an open cell may be formed and thermal insulation properties may be deteriorated.

The phenolic resin foam may include the nucleating agent, and the phenolic resin, the hydrocarbon-based foaming agent, the foaming gas, and the like may be uniformly mixed. In addition, the foaming gas is uniformly dispersed to form an appropriate nucleating site or a small cell (micelle). The diameter of the foaming cells can be made uniform to an appropriate size, and the effect of collecting the foaming gas can be maximized by increasing the stability of the wall formed between the foaming cells. Therefore, the phenolic resin foam can exhibit excellent long-term thermal conductivity and dimensional stability.

Specifically, the hydrofluoroalkane may be an alkane having 4 to 6 carbon atoms. For example, the hydrofluoroalkane is difluoromethane, fluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, penta It may include one selected from the group consisting of fluoropropane, pentafluorobutane, hexafluorobutane, isomers thereof, and combinations thereof. More specifically, the hydrofluoroalkane may be difluoromethane and/or hexafluoropropane, which has more hydrophobicity to form more uniform, foamed cells having an appropriate size during foaming of the phenolic resin. can do.

More specifically, the foamable composition contains the hydrocarbon-based foaming agent to the hydrofluoroalkane in a weight ratio of about 92:5 to about 80:20, so that the diameter of the foamed cells in the phenolic resin foam is uniform to an appropriate size. And it is possible to increase the stability of the wall formed between the foam cells.

And, the hydrofluoroether (hydrofluoroether) may be a compound represented by the following formula (1).

[Equation 1]

C _a H _b F _c -O- C _d H _e F _f

In Formula 1, a may be 1 to 9, b is 0 to 12, c is 1 to 12, d is 1 to 2, e is 1 to 5, and f may be 0 to 5, and one of Ca is the Cd can be combined with one of the following to form cyclofluoroethers.

Specifically, the hydrofluoroether may be one selected from the group consisting of 1,1,2,2-tetrafluoroethyl methyl ether, methylperfluorobutyl ether, and combinations thereof. For example, the hydrofluoroether may be methylperfluorobutyl ether, and including the hydrofluoroether, foam cells having a uniform and appropriate diameter are formed, and heat conduction while forming a solid cell wall diagram can be improved.

The nucleating agent may be included in an amount of about 0.5 parts by weight to about 2 parts by weight based on 100 parts by weight of the phenolic resin. Specifically, when the content of the nucleating agent is less than the above range, the effect of the nucleating agent is insignificant and there is a problem in that the cell uniformity is not improved. and there may be problems that impair physical properties.

The phenolic resin foam may further include hydrochloroalkene in addition to the nucleating agent, thereby preventing pin-holes from being formed in the foamed cells. For example, the hydrochloroalkene can be used together with hydrofluoroether to prevent pin-hole formation, and improve thermal insulation properties by homogenizing and stabilizing the walls of the cell.

Specifically, the hydrochloroalkene may include one selected from the group consisting of dichloroethene, dichloropropene, dichlorobutene, and combinations thereof.

The hydrochloroalkene may be included in an amount of about 0.1 to about 10 parts by weight, specifically, about 0.1 to about 5 parts by weight, or about 0.1 to about 1 part by weight, based on 100 parts by weight of the total nucleating agent. Specifically, when the content of the hydrochloroalkene is less than the above range, there is a problem that the effect of the nucleating agent is insignificant due to the addition, so there is no improvement in cell homogenization, etc., and when it exceeds the above range, the content is too high. There may be a problem of impairing physical properties because it can perform an additional reaction other than its role.

The foamed cells of the phenolic resin foam have a standard deviation of about 8.5 to about 12, have uniformly sized foamed cells, and exhibit excellent thermal insulation and dimensional stability. The standard deviation means the standard deviation for the average diameter of the foam cells. Specifically, when the standard deviation exceeds the above range, thermal conductivity may increase over the period of use, thereby reducing thermal insulation and dimensional stability.

The average diameter of the foam cells may be about 85㎛ to about 100㎛. The phenolic resin foam may include a foaming cell having an average diameter in the above range to increase the capture rate of the foaming gas, and may exhibit excellent thermal insulation and dimensional stability by maintaining low long-term thermal conductivity. Specifically, when the average diameter of the foamed cells is less than the above range, it may be difficult to control the uniformity of the size of the cells, and a complicated process is additionally required to control the problem, so there may be an uneconomic problem. And, when it exceeds the above range, there may be a problem in that the foaming gas capture rate is lowered, and the long-term thermal conductivity rate is increased.

The phenolic resin foam may include about 80% to about 90% of foamed cells having a diameter of about 90 μm to about 110 μm. The phenolic resin foam may include foam cells having an appropriate diameter in the above range in the above range. Accordingly, the capture rate of the foaming gas can be increased, and long-term thermal conductivity can be kept low to exhibit excellent thermal insulation and dimensional stability.

The phenolic resin foam may have a closed cell ratio of about 85% to about 95%. The phenolic resin foam is composed of small honeycomb-shaped cells, and the percentage of closed cells among the cells is referred to as a closed cell ratio. The higher the closed cell ratio, the better the thermal insulation properties, and the phenolic resin foam may exhibit excellent thermal insulation properties having a closed cell ratio within the above range.

Another embodiment of the present invention comprises the steps of preparing a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent; And applying heat to the foamable composition to foam and harden; including, wherein the nucleating agent comprises one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof, The standard deviation of the average diameter of the foam cells is 8.5 to 12. The above-mentioned phenolic resin foam can be manufactured by the above manufacturing method.

In the above manufacturing method, a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent is prepared. Specifically, the foamable composition may be mixed by stirring at about 100 rpm to about 1,500 rpm. Specific details of the foamable composition are the same as described above.

In addition, the manufacturing method includes the step of foaming and curing by applying heat to the prepared foamable composition.

The foaming and curing may be performed under a temperature condition of, for example, about 40 °C to about 70 °C. In addition, the foaming and curing may be performed for a time of about 2 minutes to about 20 minutes, but is not limited thereto, and may appropriately vary depending on the purpose and use of the invention.

The foamable composition, for example, may be foamed and cured in a predetermined mold or, for example, may be foamed and cured while being injected or discharged between both surface materials, but is not limited thereto. Through this, it is possible to prepare the above-described phenolic resin foam.

(Example)

Example 1 :

A resol-based phenolic resin having a viscosity of 15,000cps and a moisture content of 10% by weight under a temperature condition of 25°C was prepared at a temperature of 20°C. A foamable composition comprising the resol-based phenol resin, cyclopentane as a foaming agent, methylperfluorobutyl ether as a nucleating agent, and a castor oil-based surfactant was prepared. At this time, 1 part by weight of the nucleating agent was included with respect to 100 parts by weight of the resol-based phenol resin. Then, the foamable composition was stirred at a speed of 100 rpm to 1,500 rpm.

After aging the foamable composition at room temperature of about 25° C. for about 2 hours, it was thermosetted in a mold at 40° C. to 70° C. to prepare a foam.

Example 2

A foam was prepared in the same manner as in Example 1, except that the foamable composition was prepared by further including 1 part by weight of dichloroethylene, based on 100 parts by weight of the methylperfluorobutyl ether.

Example 3

A resol-based phenolic resin having a viscosity of 15,000cps and a moisture content of 10% by weight under a temperature condition of 25°C was prepared at a temperature of 20°C. The resol-based phenol resin, cyclopentane as a foaming agent, hexafluoropropane as a nucleating agent, and a weight ratio of cyclopentane to hexafluoropropane were 19:1, and a foamable composition including a castor oil-based surfactant was prepared. At this time, 1 part by weight of the nucleating agent was included with respect to 100 parts by weight of the resol-based phenol resin. Then, the foamable composition was stirred at a speed of 100 rpm to 1,500 rpm.

After aging the foamable composition at room temperature of about 25° C. for about 2 hours, it was thermosetted in a mold at 40° C. to 70° C. to prepare a foam.

Comparative Example 1

A resol-based phenolic resin having a viscosity of 15,000cps and a moisture content of 10% by weight under a temperature condition of 25°C was prepared at a temperature of 20°C. A foam was prepared in the same manner as in Example 1, except that a foamable composition containing a mixture of isopentane and isopropane, a castor oil-based surfactant, urea, and the like was prepared as the resol-based phenol resin and the foaming agent.

Comparative Example 2

A foam was prepared in the same manner as in Comparative Example 1, except that cyclopentane was used instead of the mixture of isopentane and isopropane as a foaming agent.

Comparative Example 3

A foam was prepared in the same manner as in Comparative Example 2, except that the foamable composition was prepared by including more parts by weight, based on 100 parts by weight of the resol-type phenol resin, including cyclopentane.

evaluation

Experimental example 1: Average of foam cells diameter , standard deviation and measurement method of the graph you provided

Foam cell diameters of the foams of Examples and Comparative Examples were measured using an electron microscope (hitachi, FE-SEM). Specifically, the foam cell diameter of each foam was measured and classified within the range of about 20 μm to about 230 μm for every 20 μm. Then, after organizing the classified values using an Excel program, the average diameter and standard deviation were calculated. And, the results are shown in Table 1 below.

Figure 1 is the foam cell diameter of the foam of Example 1, Figure 2 is the foam cell diameter of the foam of Comparative Example 1 was measured using an electron microscope (hitachi, FE-SEM), and this is shown in a graph.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Diameter (㎛) 70 16% 12% 9% One% 3% - 90 58% 72% 63% 11% 9% - 110 22% 16% 26% 17% 28% 2% 130 4% 2% 33% 36% 5% 150 - - - 16% 15% 18% 170 - - - 16% 6% 14% 190 - - - 4% 2% 38% 210 - - - One% - 15% 230 - - - - - 8% Average diameter (μm) 91.80 91.44 94.60 133.84 125.97 181.60 Standard Deviation 10.26 9.95 11.67 36.55 31.67 36.68

As shown in Table 1, the example uses a hydrocarbon-based foaming agent with a low ozone depletion index, and has a foam cell having an average diameter of 85 μm to 100 μm and a standard deviation of the average diameter of 8.5 to 12. can check On the other hand, in the comparative example, the average diameter of the foamed cells is too large and the standard deviation is large, so long-term thermal conductivity and dimensional stability will be deteriorated.

Although the present invention has been described as described above, the present invention is not limited by the embodiments disclosed herein, and it is apparent that various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, although the effects according to the configuration of the present invention are not explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

Claims (12)

It is a thermosetting product of a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent,
The nucleating agent includes one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof,
The foamable composition does not contain isopropylchloride and hydrofluoroolefin,
Based on 100 parts by weight of the phenolic resin, the nucleating agent is included in an amount of 0.5 to 2 parts by weight,
The hydrofluoroalkane is difluoromethane, fluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, pentafluoro containing one selected from the group consisting of ropropane, pentafluorobutane, hexafluorobutane, isomers thereof, and combinations thereof,
The hydrofluoroether is one selected from the group consisting of 1,1,2,2-tetrafluoroethyl methyl ether, methylperfluorobutyl ether, and combinations thereof,
the standard deviation of the average diameter of the foam cells is 8.5 to 12,
The average diameter of the foam cells is 85㎛ to 94.6㎛
Phenolic resin foam.
The method of claim 1,
The hydrocarbon-based blowing agent is n-butane, isobutane, n-pentane, isopentane, cyclopentane, n-hexane, and comprising one compound selected from the group consisting of combinations thereof
Phenolic resin foam.
The method of claim 1,
The foamable composition comprises the hydrocarbon-based blowing agent to the hydrofluoroalkane in a weight ratio of 92:5 to 80:20
Phenolic resin foam.
delete delete delete The method of claim 1,
Hydrochloroalkene further comprising
Phenolic resin foam.
8. The method of claim 7,
The hydrochloroalkene includes one selected from the group consisting of dichloroethylene, dichloropropene, dichlorobutene, and combinations thereof.
Phenolic resin foam.
8. The method of claim 7,
The hydrochloroalkene is contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total nucleating agent.
Phenolic resin foam.
delete The method of claim 1,
80% to 90% of foamed cells having a diameter of 90 μm to 110 μm
Phenolic resin foam.
Preparing a foamable composition comprising a phenol-based resin, a hydrocarbon-based foaming agent and a nucleating agent; and
Including; foaming and curing by applying heat to the foamable composition;
The step of preparing the foamable composition is prepared by mixing the foamable composition by stirring at 100 rpm to 1,500 rpm,
The nucleating agent includes one selected from the group consisting of hydrofluoroalkane, hydrofluoroether, and combinations thereof,
The foamable composition does not contain isopropylchloride and hydrofluoroolefin,
Based on 100 parts by weight of the phenolic resin, the nucleating agent is included in an amount of 0.5 to 2 parts by weight,
The hydrofluoroalkane is difluoromethane, fluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, pentafluoro containing one selected from the group consisting of ropropane, pentafluorobutane, hexafluorobutane, isomers thereof, and combinations thereof,
The hydrofluoroether is one selected from the group consisting of 1,1,2,2-tetrafluoroethyl methyl ether, methylperfluorobutyl ether, and combinations thereof,
the standard deviation of the average diameter of the foam cells is 8.5 to 12,
The average diameter of the foam cells is 85㎛ to 94.6㎛
A method for producing a phenolic resin foam.

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