KR20230087995A - Polystyrene-phenol composite foam and method of producing the same - Google Patents

Abstract

It includes a phenolic resin, expanded polystyrene beads, and a foaming agent, has a density of 25 kg/m3 to 35 kg/m3, and a thermal conductivity measured at an average temperature of 20° C. according to KS L 9016 of 0.017 W/m. A polystyrene-phenol composite foam having a K to 0.022 W/m·K is provided.

Description

Polystyrene-phenol composite foam and its manufacturing method {POLYSTYRENE-PHENOL COMPOSITE FOAM AND METHOD OF PRODUCING THE SAME}

The present invention relates to a polystyrene-phenol composite foam and a manufacturing method thereof.

Phenolic foam has excellent insulation performance and excellent flame retardant performance, so it is an insulation material that is increasingly in demand these days when energy saving and fire stability are becoming more and more important.

On the other hand, phenolic foam has problems in that raw materials are expensive, hard, brittle, and not light, so that it is uneconomical and has poor workability.

Therefore, there is a need for a foam that is more economically inexpensive and has excellent workability by supplementing the above disadvantages of the phenolic foam and does not degrade the advantages of the phenol foam.

An object of the present invention is to provide a composite foam that simultaneously exhibits excellent physical properties such as low thermal conductivity, dimensional stability and excellent compressive strength while improving economic efficiency and workability due to low brittleness and low density by including polystyrene beads in a phenolic foam.

It is also an object of the present invention to provide a method for producing the composite 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 above can 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 means of the instrumentalities and combinations indicated in the claims.

It includes a phenolic resin, expanded polystyrene beads and a foaming agent according to the present invention, has a density of 25 kg / m 3 to 35 kg / m 3, and a thermal conductivity measured at an average temperature of 20 ° C according to KS L 9016 is 0.017 A polystyrene-phenol composite foam having W/m·K to 0.022 W/m·K can be provided.

In addition, preparing a foamable composition comprising a phenolic resin, unexpanded polystyrene beads and a foaming agent according to the present invention; and injecting the foamable composition into a mold and foaming and curing; the density is 25 kg/m3 to 35 kg/m3, and the thermal conductivity measured at an average temperature of 20°C according to KS L 9016 is 0.017 W/m It is possible to provide a method for producing a polystyrene-phenol composite foam having a K to 0.022 W/m K.

The polystyrene-phenol composite foam according to the present invention can exhibit excellent physical properties such as low thermal conductivity, dimensional stability, and excellent compressive strength while improving economic efficiency and workability due to low brittleness and low density.

In addition, the method for producing a polystyrene-phenol composite foam according to the present invention can manufacture the polystyrene-phenol composite foam.

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

1 is a view showing the positions of a surface cross section (CSs) and a cross section (CSc) including a center portion of a polystyrene-phenol composite foam and polystyrene beads distributed in the cross section.
2 is a schematic diagram briefly showing a method for measuring the dimensional stability of a polystyrene-phenol composite foam according to another embodiment of the present invention.

The above objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention belongs will be able to easily implement the technical spirit of the present invention. In describing the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter 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. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, the arrangement of an arbitrary element on the "upper (or lower)" or "upper (or lower)" of a component means that an arbitrary element is placed in contact with the upper (or lower) surface of the component. In addition, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

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

One embodiment of the present invention includes a phenolic resin, expandable polystyrene beads and a foaming agent, has a density of 25 kg / m 3 to 35 kg / m 3, and measured at an average temperature of 20 ° C according to KS L 9016 A polystyrene-phenol composite foam having a thermal conductivity of 0.017 W/m K to 0.022 W/m K is provided.

Phenolic foam has excellent insulation performance and excellent flame retardant performance, but has problems in that the raw material price is expensive, it is rigid, brittle, and not light, so it is uneconomical and poor workability.

Accordingly, there is a tendency to include inexpensive expanded polystyrene beads (EPS) in the phenolic foam to impart flexibility to the phenolic foam and to produce a foam having a low density.

On the other hand, the phenolic foam contains a foaming agent, and reaction heat is generated during foaming and curing, and physical properties such as thermal conductivity tend to be greatly affected by the size, uniformity, and degree of closed cell ratio of the foamed cells.

Therefore, when a lot of expanded polystyrene beads (EPS) are included to lower the density of the phenolic foam to a certain level or more and impart flexibility, the thermal conductivity is rather increased, reducing the advantages of the phenolic foam and lowering the compressive strength. There is a problem with this degradation.

On the other hand, the polystyrene-phenol composite foam includes a phenolic resin, a foaming agent, and expandable polystyrene, and has a low density of 25 kg/m3 to 35 kg/m3, and at the same time, according to KS L 9016 The thermal conductivity measured at an average temperature of 20 ° C is 0.017 W / m K to 0.022 W / m K, which can simultaneously exhibit excellent thermal conductivity.

Specifically, the polystyrene-phenol composite foam includes a phenolic resin.

The phenol-based resin may be obtained by reacting phenol and formaldehyde, and may include, for example, a resol-based phenolic resin (hereinafter referred to as 'resol resin').

The phenolic resin may be included in an amount of about 30% by weight to about 70% by weight in the polystyrene-phenol composite foam. The phenolic resin foam may stably form small-sized foam cells and realize excellent thermal conductivity by including the phenolic resin in an amount within the above range.

The polystyrene-phenol composite foam includes a blowing agent. For example, the blowing agent may include one selected from the group consisting of hydrofluoroolefin (HFO)-based compounds, hydrocarbon-based compounds, and combinations thereof. Specifically, the hydrofluoroolefin-based compound is, for example, monochlorotrifluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, hexafluorobutene, and combinations thereof. It may include at least one selected from the group consisting of And, the hydrocarbon-based compound may include a hydrocarbon having 1 to 5 carbon atoms. For example, the hydrocarbon-based compound is dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride, n-butane, isobutane, n-pentane, isopentane, cyclopentane and It may include at least one selected from the group consisting of combinations thereof. The foaming agent may be included in an amount of about 6 parts by weight to about 20 parts by weight based on about 100 parts by weight of the phenolic resin. or about 8 parts by weight to about 20 parts by weight, about 9 parts by weight to about 20 parts by weight, about 6 parts by weight to about 17 parts by weight, about 6 parts by weight to about 15 parts by weight, about 8 parts by weight to about 17 parts by weight , About 8 parts by weight to about 15 parts by weight, about 9 parts by weight to about 17 parts by weight, or about 9 parts by weight to about 15 parts by weight.

And, the polystyrene-phenol composite foam includes a curing agent. The curing agent may include 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 phenolic resin foam may exhibit appropriate crosslinking, curing, and foaming properties by including the curing agent. The curing agent may be included in an amount of about 10 parts by weight to about 25 parts by weight based on 100 parts by weight of the phenolic resin. Alternatively, the curing agent is about 10 parts by weight to about 23 parts by weight, about 10 parts by weight to about 20 parts by weight, about 10 parts by weight to about 18 parts by weight, about 13 parts by weight to about 100 parts by weight of the phenolic resin 23 parts by weight, about 15 parts by weight to about 23 parts by weight, about 18 parts by weight to about 23 parts by weight, about 13 parts by weight to about 20 parts by weight, about 13 parts by weight to about 18 parts by weight, about 15 parts by weight to about It may be included in an amount of 20 parts by weight or about 15 parts by weight to about 18 parts by weight.

The composite foam may exhibit appropriate crosslinking, curing, and foaming properties by including the curing agent in an amount within the above range. The content of the curing agent means the content of a mixture obtained by mixing a substance such as toluenesulfonic acid with a solvent such as ethylene glycol.

The polystyrene-phenol composite foam includes expandable polystyrene together with the phenolic resin and the foaming agent.

Polystyrene beads contain a material that expands and vaporizes when heated. For example, the polystyrene beads may contain propane-based hydrocarbons therein. The polystyrene beads may be derived from commonly used styrene polymers. As well as using styrene as the sole monomer, other addition polymerizable monomers may be used, and such copolymers are included in the term polystyrene in the present invention. Styrene is always present as a major component of polystyrene polymers. The polystyrene beads may be modified with one or more additives, such as flame retardants, smoke suppressants, antistatic agents, rheology enhancers or modifiers. For example, polystyrene particles can be coated or impregnated with flame retardants to enhance flame retardancy. As the flame retardant, conventionally used inorganic flame retardants such as graphite, expanded graphite, and aluminum hydroxide or phosphorus-based flame retardants such as red, phosphate, and phosphoric acid may be used alone or in appropriate combination.

The expanded polystyrene beads may reduce brittleness and density by imparting flexibility to the composite foam.

Specifically, the expanded polystyrene beads may be included in an amount of about 10 parts by weight to 50 parts by weight based on 100 parts by weight of the phenolic resin. Accordingly, while the density of the polystyrene-phenol composite foam is lowered, physical properties such as excellent thermal conductivity can be exhibited at the same time. For example, when the content of the expanded polystyrene beads is less than the above range, the effect of reducing the density of the phenolic foam is insignificant, and when it exceeds the above range, the phenolic resin ratio is greatly lowered to lower the internal heating temperature , the expansion ratio of the polystyrene beads may also be lowered. Therefore, there may be a problem in that the thermal conductivity and compressive strength of the composite foam are lowered.

In general, heat of reaction is generated during foaming and curing of a phenolic foam, and heat of reaction is accumulated in the center in the thickness direction of the foam during the foaming and curing process, and thus relatively excessive expansion is likely to occur. Accordingly, the size and uniformity of cells at each position according to the thickness of the foam tends to vary, and accordingly, physical properties such as thermal conductivity of the foam tend to be greatly affected.

In the polystyrene-phenol composite foam, physical properties of the composite foam may be appropriately controlled by appropriately adjusting the distribution and expansion degree of the polystyrene beads included therein.

Specifically, the average diameter of the expanded polystyrene beads included in the polystyrene-phenol composite foam may satisfy Equation 1 below.

[Equation 1]

68 ≤ (ds/dc) X100 ≤ 95

The polystyrene-phenol composite foam may be a hexahedral panel foam having a thickness in the direction in which the foaming composition expands and both surfaces to which a face member or the like is attached.

1 is a view showing the positions of a surface cross section (CSs) and a cross section (CSc) including a center portion of a polystyrene-phenol composite foam and polystyrene beads distributed in the cross section.

As shown in FIG. 1, in Equation 1, dc is the number of the expanded polystyrene beads distributed in a cross section (CSc) perpendicular to the thickness direction including the 1/2 thickness point of the composite foam where the most heat is accumulated in the foam. It represents the average diameter (dc), and ds is the thickness direction from the surface to which the face material is attached, for example, to measure the diameter of the polystyrene beads distributed on the surface while excluding the influence of external contaminants. It shows the average diameter (ds) of the expanded polystyrene beads distributed in the cross-section (CSs) perpendicular to the thickness direction and including the point 5 mm inward. The average diameter ds may be 2 mm to 5 mm or 2.3 mm to 5 mm.

In this case, the average diameter means an average value obtained by dividing the total sum of diameters of polystyrene beads distributed in the cross section by the number of polystyrene beads included in the cross section. And, at this time, the diameter of the polystyrene bead is a line segment connecting two points on the circumference of the bead, for example, the circumference of the bead in a straight line passing through the center of the polystyrene bead, for example, the center of the circle, exposed on the two-dimensional plane, which is each cross section. means the maximum value of the length of

Through the ratio of “ds/dc”, it is possible to know the extent to which the foaming and curing process has been performed and the degree of influence of the polystyrene beads during the process.

Specifically, when the “ds / dc” of the polystyrene-phenol composite foam is less than the above range, it shows that the polystyrene beads of the surface portion are not sufficiently expanded, and the thermal conductivity of the polystyrene-phenol composite foam is increased and the surface density is increased. The effect of reducing the density of the composite foam may be significantly reduced.

The average diameter of the expanded polystyrene beads included in the polystyrene-phenol composite foam may be 70 to 95, 75 to 95, or 77 to 95 in “(ds/dc) X100” in Equation 1 above.

The composite foam is manufactured by including unexpanded polystyrene beads in a foaming composition, absorbs heat generated during foaming and curing, and is included in a cross section (CSc) perpendicular to the thickness direction including a 1/2 thickness point. An average diameter (dc) of the expanded polystyrene beads may be 2 mm to 5 mm. By maximally expanding the polystyrene beads within the above range to lower thermal conductivity, improve the brittleness and dimensional stability of the phenolic foam, and lower the density as much as possible, economically inexpensive products can be realized and workability can be improved. For example, the average diameter (dc) of the expanded polystyrene beads may be 3 mm to 5 mm.

The polystyrene-phenol composite foam may further include one surfactant selected from the group consisting of amphoteric, cationic, anionic, and nonionic surfactants, and combinations thereof. For example, the phenolic resin foam may include an ethoxylated castor oil surfactant (eg, LG Household & Health Care, ELOTANT COE 131), that is, a nonionic surfactant.

The polystyrene-phenol composite foam, including the expanded polystyrene beads together with the phenolic resin and the foaming agent, exhibits flexibility and lowers brittleness, and has 25 kg/m3 to 35 kg/m3, 25 kg/m3 to 34.5 kg / m 3 or 25 kg / m 3 to 34.4 kg / m 3 shows a low density can improve workability.

In addition, the thermal conductivity of the polystyrene-phenol composite foam measured at an average temperature of 20 ° C according to KS L 9016 is 0.017 W / m K to 0.022 W / m K, which indicates excellent physical properties of the excellent phenol foam. For example, the polystyrene-phenol composite foam may have a thermal conductivity of 0.017 W/m·K to 0.0215 W/m·K or 0.017 W/m·K to 0.020 W/m·K at an average temperature of 20°C.

In addition, the polystyrene-phenol composite foam may exhibit a compressive strength of 100 kPa to 300 kPa according to KS M ISO 844. Compressive strength means the pressure when the foam is broken, and the polystyrene-phenol composite foam has a compressive strength within the above range, thereby maintaining an excellent balance between physical properties and exhibiting excellent long-term durability even after distribution and construction. . For example, the polystyrene-phenol composite foam may have a compressive strength of about 110 kPa to 300 kPa or about 115 kPa to 300 kPa.

An average value of the dimensional change rate of the polystyrene-phenol composite foam according to Equation 2 below may be 0% to 1.0%.

[Equation 2]

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

In Equation 2, the initial length (a) is the length of each line at n equal points in the length (L) and width (W) directions of the composite foam, and the final length (a') is the length of the composite foam It means the final length (a') of each line at the point after leaving it in an oven at 70 ° C. for 48 hours. (n is 2 to 5)

It can be seen that the composite includes the polystyrene beads and exhibits excellent dimensional stability in the above range. Accordingly, the polystyrene-phenol composite foam exhibits excellent thermal conductivity, so that long-term thermal insulation properties can be more effectively improved, and processability and workability can be further improved when applied as a predetermined product. For example, the polystyrene-phenol composite foam may have a dimensional change of about 0% to about 0.6% or about 0% to about 0.57%.

In general, when the thickness of a phenolic foam exceeds a certain level, a large amount of reaction heat is accumulated in the center of the foam in the thickness direction during the foaming and curing process, and thus relatively excessive expansion is likely to occur. Accordingly, the cell size and physical properties vary depending on the thickness of the foam, which may result in a problem of deteriorating the physical properties of the entire foam. This may become more severe as the thickness of the foam increases.

The thickness of the composite foam may be 20 mm to 150 mm,

The composite foam is manufactured by the manufacturing method described below, and a foam of high thickness is easily prepared by including unexpanded polystyrene beads in the composition and expanding and foaming the polystyrene beads using the heat of reaction generated during the foaming and curing process. can do. For example, the thickness of the composite foam may be 30 mm to 150 mm, 40 mm to 150 mm, 50 mm to 150 mm, 60 mm to 150 mm, 70 mm to 150 mm, or 80 mm to 150 mm,

In addition, even when the composite foam is a high-thickness foam, it can maintain a constant range of 'ds/dc' as described above and exhibit excellent physical properties such as low density, thermal conductivity, compressive strength, and dimensional stability.

Another embodiment of the present invention comprises the steps of preparing a foamable composition comprising a phenolic resin, unexpanded polystyrene beads and a foaming agent; and injecting the foamable composition into a mold and foaming and curing; the density is 25 kg/m3 to 35 kg/m3, and the thermal conductivity measured at an average temperature of 20°C according to KS L 9016 is 0.017 W/m · K to 0.022 W / m · K Provided is a method for producing a polystyrene-phenol composite foam.

As described above, it is possible to prepare a polystyrene-phenol composite foam that simultaneously exhibits excellent physical properties such as low thermal conductivity, dimensional stability, and excellent compressive strength while improving economic efficiency and workability with low brittleness and low density. Matters related to the phenolic resin, foaming agent, polystyrene beads, etc. are the same as described above except for those specifically described below.

First, a method for producing a polystyrene-phenol composite foam includes preparing a foamable composition including a phenolic resin, unexpanded polystyrene beads, and a foaming agent.

The manufacturing method may include unexpanded polystyrene beads in the expandable composition so that the polystyrene beads are uniformly mixed. For example, when mixing expanded polystyrene beads into an expandable composition, the already expanded beads are too bulky and too low in density, which can make it difficult to mix them uniformly within the composition.

The diameter of the unexpanded polystyrene beads may be 0.25 mm to 2 mm. For example, 0.25 mm to 1.7 mm, 0.25 mm to 1.5 mm, 0.25 mm to 1.2 mm, 0.5 mm to 2 mm, 0.5 mm to 1.7 mm, 0.5 mm to 1.5 mm, 0.5 mm to 1.2 mm, 0.7 mm to 2 mm. mm, 0.7 mm to 1.7 mm, 0.7 mm to 1.5 mm, 0.7 mm to 1.2 mm, 1 mm to 2 mm, 1 mm to 1.7 mm, 1 mm to 1.5 mm, or 1 mm to 1.2 mm.

The bead may have a spherical shape. In this case, the diameter is a straight line passing through the center of the spherical polystyrene bead and means the maximum value of the length of a line segment connecting two points on the circumference of the bead. In the case of other shapes, it means the length of the major axis when divided into major axis and minor axis. The diameter can be measured by a Laser Particle Size Analyzer (model name: BT-2000).

Accordingly, the formation and size of air bubbles can be appropriately controlled during the foaming and curing process of the phenolic resin, and the polystyrene beads can be easily and homogeneously mixed into the phenolic resin. It can be evenly distributed to increase product stability.

The unexpanded polystyrene beads can be expanded and distributed while absorbing reaction heat generated during the foaming and curing of the foamable composition. At this time, when the expansibility of the polystyrene beads is maximized, flexibility is sufficiently imparted to the composite material, brittleness is reduced, and low density can be implemented.

On the other hand, when the unexpanded polystyrene beads are expanded, the phenolic resin is foamed and cured simultaneously, so that the foamable composition expands the unexpanded polystyrene beads, while at the same time the foaming agent included in the composition is well foamed and cured. A level of reactivity required to cure it.

The foamable composition may use a highly reactive resin as a phenolic resin. The foamable composition may cause a high exothermic reaction when a foaming and curing reaction occurs using a highly reactive phenolic resin, and the polystyrene beads added in the composition may be maximally expanded.

In general phenolic foams, when the heat of reaction is high due to high reactivity, excessive heat is accumulated in the center of the foam, which damages cell cells and the like, which may cause a problem of deterioration of physical properties.

Meanwhile, the composite foam includes non-expanded polystyrene beads, and heat accumulation can be dispersed by the included polystyrene beads.

Accordingly, the cell structure of the composite foam may be stably maintained while the polystyrene beads expand to the maximum by appropriately adjusting the reactivity of the phenolic resin and the addition amount of the polystyrene beads. In addition, by adjusting the rate and degree of foaming and curing of the foaming agent, the collection rate of the foaming agent may be increased and the physical properties of the foam may be improved.

Specifically, the moisture content of the phenolic resin may be greater than 7% by weight and less than 11% by weight. For example, the water content of the phenolic resin is 7.5% to 11% by weight, 8% to 11% by weight, 7% to 10% by weight, 7.5% to 10% by weight, 8% to 10% by weight % can be When the moisture content of the phenolic resin is less than the above range, the reactivity of the phenolic resin is too high, and cell destruction may occur due to overheating during foaming. may not be The water content can be controlled by the amount of water added during polymerization of the phenolic resin, and the water content in the resin can be confirmed by Karl-Fischer titration.

In addition, the phenolic resin may exhibit a viscosity of 7,000 to 12,000cps at 25°C. For example, the phenolic resin has 8,000cps to 12,000cps, 9,000cps to 12,000cps, 7,000cps to 11,000cps, 7,000cps to 10,000cps, 7,000cps to 9,000cps, 8,000cps to 11, 000cps, 8,000cps to 10,000cps, 8,000cps to 9,000cps.

The viscosity may be measured with a Brookfield viscometer.

The phenolic resin may increase the internal temperature of the foam to a certain level or higher during the foaming and curing process by using a highly reactive phenolic resin having a viscosity within the above range and/or a moisture content as described above. Accordingly, while maximally expanding the non-expanded polystyrene beads, the expansion of the foaming agent in the composition is appropriately controlled at a constant speed, so that excellent physical properties can be imparted to the polystyrene-phenol composite foam.

In addition, the phenol-based resin may exhibit a maximum temperature of 150° C. or more when 500 g of the phenol-based resin is added with 20 g of a curing agent, for example, a curing agent containing toluene sulfonic acid, and stirred. For example, it may indicate a maximum temperature of 150 ° C to 180 ° C, 155 ° C to 180 ° C or 160 ° C to 180 ° C. When the maximum temperature of the phenolic resin is less than the above range, there is a problem in that sufficient heat of reaction is not generated during foaming of the composite foam and thus polystyrene is not sufficiently expanded. There may be a problem in which cell destruction occurs.

The highest temperature of the phenolic resin may appear between 8 and 20 minutes after the curing agent is added. or between 8 and 15 minutes or between 8 and 10 minutes.

The foamable composition may further include 3 to 10 parts by weight of urea based on 100 parts by weight of the phenolic resin.

Thereafter, the step of putting the foamable composition into a mold and foaming and curing it is included. Among conventional foams containing polystyrene beads, there are cases in which a compression step is performed at the time of manufacture. On the other hand, in the manufacturing method including a foaming agent, foaming and curing as in the present invention, when the compression process is performed, problems such as increased thermal conductivity and the like may occur as closed cell cells of the phenolic foam are destroyed. Accordingly, the present invention does not include a compression process.

The foamable composition is put into a mold and foaming and curing proceed. At this time, the temperature of the mold may be 75 ℃ to 90 ℃. In this way, by adjusting the temperature of the mold within the above range, it is possible to reduce the temperature difference between the maximum temperature at the center of the foam and the temperature at the surface of the foam, which occurs during the foaming and curing of the foamable composition.

In this way, by controlling the temperature difference, the distribution and degree of expansion of the expanded polystyrene beads included in the final foam can be controlled, and physical properties such as excellent thermal conductivity of the phenolic foam can be excellently displayed. For example, the temperature of the mold may be 75 °C to 80 °C or 80 °C to 90 °C.

Another embodiment of the present invention provides an insulator comprising the polystyrene-phenol composite foam. The polystyrene-phenol composite foam has low brittleness and low density, improves economics and workability, and simultaneously satisfies excellent physical properties such as low thermal conductivity, dimensional stability, and excellent compressive strength, and can be used as a building insulation material.

The building insulation material may further include, for example, a face material on one side or both sides of the phenolic foam, and the flame retardancy may be further improved by including aluminum as the face material.

(Example)

Example 1:

250 g of a resol resin having a viscosity of 9,000 cps at 25° C. and a moisture content of 8% by weight was prepared. And, relative to 100 parts by weight of the resol resin, 3 parts by weight of ethoxylated castor oil surfactant, 5 parts by weight of powdery urea, 9 parts by weight of cyclopentane as a blowing agent, and polystyrene beads with an unexpanded diameter of 1.2 mm (LG Chem, R160) 10 parts by weight were mixed well with a high-speed stirrer to make a premix.

And, based on 100 parts by weight of the resol resin, 18 parts by weight of a mixture obtained by mixing 80% by weight of toluenesulfonic acid with 15% by weight of ethylene glycol and 5% by weight of water was evenly mixed with the premix to prepare a foamable composition.

Then, the foamable composition was put into a mold having a size of 250 mm X 250 mm X 80 mm and set at 80° C. and heated, and then foamed and cured in the mold for 10 minutes. Then, the foam taken out of the mold was placed in an oven at 80° C. and cured for one day to prepare a polystyrene-phenol composite foam having a thickness of 80 mm.

Example 2:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 1, except that 30 parts by weight of unexpanded polystyrene beads (LG Chem, R160) was included relative to 100 parts by weight of the resol resin.

Example 3:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 1, except that 50 parts by weight of unexpanded polystyrene beads (LG Chem, R160) was included relative to 100 parts by weight of the resol resin.

Comparative Example 1:

250 g of a resol resin having a viscosity of 14,000 cps at 25° C. and a moisture content of 13% by weight was prepared. In addition, 3 parts by weight of the ethoxylated castor oil surfactant, 5 parts by weight of powdered urea, and 9 parts by weight of cyclopentane as a foaming agent were mixed well with a high-speed stirrer to prepare a premix with 100 parts by weight of the resol resin.

And, based on 100 parts by weight of the resol resin, 18 parts by weight of a mixture obtained by mixing 80% by weight of toluenesulfonic acid with 15% by weight of ethylene glycol and 5% by weight of water was evenly mixed with the premix to prepare a foamable composition.

Then, the foamable composition was put into a mold having a size of 250 mm X 250 mm X 80 mm and set at 65°C and heated, and then foamed and cured in the mold for 10 minutes. Then, the foam taken out of the mold was placed in an oven at 80° C. and cured for one day to prepare a phenolic foam having a thickness of 80 mm.

Comparative Example 2:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 2, except that the expandable composition was prepared using 30 parts by weight of expanded polystyrene beads (LG Chem, R160) with a diameter of 4 mm instead of unexpanded polystyrene beads. did

Comparative Example 3:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 1, except that 5 parts by weight of unexpanded polystyrene beads (LG Chem, R160) were included relative to 100 parts by weight of the resol resin.

Comparative Example 4:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 1, except that 60 parts by weight of unexpanded polystyrene beads (LG Chem, R160) was included relative to 100 parts by weight of the resol resin.

Comparative Example 5:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 2, except that a resol resin having a water content of 5% by weight was used.

Comparative Example 6:

A polystyrene-phenol composite foam was prepared in the same manner as in Example 2, except that a resol resin having a moisture content of 15% by weight was used.

evaluation

Experimental Example 1: Reactivity of phenolic resin

Example 1, Comparative Examples 5 and 6 500g of each resol resin was weighed into a beaker and 20g of a mixture of 80% by weight of toluenesulfonic acid mixed with 15% by weight of ethylene glycol and 5% by weight of water was added as a curing agent at a speed of 1500 rpm. Stir. In addition, the beaker was placed in a prepared insulated box, and the maximum reaction temperature and the time required to reach the maximum temperature were measured using a K-type temperature sensor at the center of the beaker where the reaction occurred. And the results are shown in Table 1 below.

Maximum temperature (℃) Time taken (minutes) Example 1 162 9 minutes 43 seconds Comparative Example 5 187 6 minutes 51 seconds Comparative Example 6 124 23 minutes 15 seconds

Experimental Example 2: Average diameter (mm) of expanded polystyrene beads (EPS beads)

Composite foam samples having a size of 30 mm (L) X 30 mm (W) or more were prepared from Examples 4 and 6 as Examples and Comparative Examples. Then, the sample was freeze-dried in liquid nitrogen for 1 minute, and then a cross-section including the surface and the central portion of the composite foam was cut with a sharp thin razor blade.

Specifically, in the cross section (CSs) including the surface of the composite foam, a face material is attached from the surface, for example, to measure the diameter of the polystyrene beads distributed on the surface while excluding the influence of external contaminants. It was cut parallel to the foam surface to include a point 5 mm inward in the thickness direction from the surface to be formed and to include a cross section (CSs,) perpendicular to the thickness direction.

And, as for the cross section (CSc) including the central portion of the composite foam, the 1/2 point in the thickness direction before cutting was flatly cut perpendicularly to the thickness direction (parallel to the surface to which the face material is attached).

Then, the average diameter (ds) of the polystyrene beads included in the cross section (CSs) including a point 5 mm inward from the surface of the foam in the thickness direction and included in the cross section (CSc) including the central portion of the composite foam The average diameter (dc) of the polystyrene beads was measured using a digital microscope (manufacturer: Leica Microsystems, model name: DVM6) as a photograph of an image of an area of 20 mm X 16 mm, and the maximum diameter of each polystyrene bead on the image was measured using a dimension drawing tool. was measured and the average value was recorded. And the results are shown in Table 2 below. In this case, the average diameter means an average value obtained by dividing the total sum of diameters of polystyrene beads included in the cross section by the number of polystyrene beads included in the cross section. Further, the diameter of the polystyrene bead means the maximum value of the length of a line segment connecting two points on the circumference of the bead in a straight line passing through the center of the polystyrene bead.

EPS bead average diameter (ds) on foam surface (CSs) (mm) Average diameter of EPS beads at the center of the foam (dc) (mm) (ds/dc)X100
(%) Example 1 3.3 3.6 92 Example 2 2.7 3.3 82 Example 3 2.3 3 77 Comparative Example 4 1.5 2.4 63 Comparative Example 6 1.3 1.6 81

Experimental Example 3: Density (kg/m3)

The foams of Examples and Comparative Examples were cut into a size of 200 mm (L, width) X 200 mm (W, width) X 50 mm (T, thickness) while including the 1/2 point of the thickness in the center to obtain a specimen. After preparing, the weight, width, length, and thickness of the specimen were measured and calculated.

Experimental Example 4: Thermal Conductivity (W/m K)

The foams of Examples and Comparative Examples were cut into a size of 200 mm (L, width) X 200 mm (W, width) X 50 mm (T, thickness) while including the 1/2 point of the thickness in the center to obtain a specimen. After preparing, the specimen was pretreated by drying at 70° C. for 12 hours. In addition, the thermal conductivity of the specimen was measured using an HC-074-300 (EKO) thermal conductivity device at an average temperature of 20 ° C according to the measurement conditions of KS L 9016 (plate heat flow measurement method), and the results are shown in the table below 3.

Experimental Example 5: Compressive Strength (kPa)

The foams of Examples and Comparative Examples were prepared as specimens of 50 mm (L) ХΧ 50 mm (W) ХΧ 50 mm (T) size, and the specimens were placed between wide plates of Lloyd instruments LF Plus Universal Testing Machine, UTM It was measured by setting the speed at 10%/min of the specimen thickness (5 mm/min) in the equipment, and the strength was measured until the sample thickness was deformed by 10% (5 mm), and the maximum value was recorded. Compressive strength was measured by the method of KS M ISO 844 standard, and the results are shown in Table 3 below.

Experimental Example 6: Dimensional stability (%)

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

The foams of Examples and Comparative Examples were prepared as specimens having a size of 100 mm (L) ХΧ 100 mm (W) ХΧ 50 mm (T). And, as shown in FIG. 1, draw a line at n (n = 3) points even in the length (L) and width (W) directions of the specimen, and measure the initial length (a) of each line at 25 ° C did

In addition, after leaving the specimen in an oven at 70 ° C. for 48 hours, the final length (a ') of each point was measured, and the dimensional change rate (%) changed from the initial dimension was measured by Equation 1 below, respectively, and the average value was It is listed in Table 3. Dimensional stability was measured by the method of KS M ISO 2796 standard.

Density (kg/㎥) Thermal conductivity (W/m K) Compressive strength (kPa) Dimensional stability (%) Example 1 34.4 0.0191 135.6 0.57 Example 2 31.2 0.0194 124.5 0.44 Example 3 27.9 0.0215 115.8 0.32 Comparative Example 1 37.6 0.0189 146.5 0.77 Comparative Example 2 32.1 0.0236 81.3 1.34 Comparative Example 3 36.5 0.0211 107.7 0.84 Comparative Example 4 28.6 0.0288 97.9 0.45 Comparative Example 5 30.8 0.0264 73.8 1.25 Comparative Example 6 35.2 0.0239 99.2 0.96

Unlike Comparative Example 1, the polystyrene-phenol composite foam of Example did not break easily after being cut. And, as shown in Table 3, in the composite foams of the examples, the polystyrene beads included in the foam expand at an appropriate average diameter and ratio ((ds / dc) X100) to realize low density, while achieving thermal conductivity, compressive strength, dimensional stability, etc. It can be seen that it exhibits excellent physical properties in the physical properties of. On the other hand, in Comparative Examples 2 to 6, it can be confirmed that the polystyrene beads do not expand to an appropriate average diameter and ratio ((ds/dc) X100) or the physical properties are rather deteriorated.

As described above, the present invention has been described with reference to the drawings illustrated, but the present invention is not limited by the embodiments and drawings disclosed herein, and various modifications are made by those skilled in the art within the scope of the technical idea of the present invention. It is obvious that variations can be made. In addition, although the operation and effect according to the configuration of the present invention have not been explicitly described and described while describing the embodiments of the present invention above, it is natural that the effects predictable by the corresponding configuration should also be recognized.

Claims (12)

A phenolic resin, expanded polystyrene and a foaming agent,
The density is 25 kg / m 3 to 35 kg / m 3,
The thermal conductivity measured at an average temperature of 20 ° C according to KS L 9016 is 0.017 W / m K to 0.022 W / m K
Polystyrene-phenol composite foam.
According to claim 1,
The average diameter of the expanded polystyrene beads included in the composite foam satisfies the following formula 1
Polystyrene-phenolic composite foam:

[Equation 1]
68 ≤ (ds/dc) X100 ≤ 95

In Equation 1, ds is the average diameter of the expanded polystyrene beads (ds) distributed over a cross section (CSs) perpendicular to the thickness direction and including a point 5 mm inward from any one surface of the composite foam in the thickness direction ) is shown,
dc represents the average diameter (dc) of the expanded polystyrene beads distributed in a cross section (CSc) perpendicular to the thickness direction and including a point of 1/2 the thickness of the composite foam.
According to claim 1,
The average diameter (dc) of the expanded polystyrene beads including the thickness 1/2 point of the composite foam and distributed in the cross section (CSc) perpendicular to the thickness direction is 2 mm to 5 mm
Polystyrene-phenol composite foam.
According to claim 1,
10 to 50 parts by weight of the expanded polystyrene beads based on 100 parts by weight of the phenolic resin
Polystyrene-phenol composite foam.
According to claim 1,
Compressive strength according to KS M ISO 844 is 100 kPa to 300 kPa
Polystyrene-phenol composite foam.
According to claim 1,
The average value of the dimensional change rate according to the following formula 2 is 0% to 1.0%
Polystyrene-phenolic composite foam:

[Equation 2]
Dimensional change rate (%) = {|initial length (a)-final length (a')|/initial length (a)} X 100

In Equation 2, the initial length (a) is the length of each line at equal n points in the length (L) and width (W) directions of the composite foam, and the final length (a') is the composite foam It means the final length (a') of each line at the point after leaving it in an oven at 70 ° C for 48 hours. (n is 2 to 5)
According to claim 1,
The thickness of the composite foam is 20 mm to 150 mm
Polystyrene-phenol composite foam.
preparing a foamable composition comprising a phenolic resin, unexpanded polystyrene beads and a foaming agent; and
Including; injecting the foamable composition into a mold and foaming and curing;
The density is 25 kg / m 3 to 35 kg / m 3,
Thermal conductivity measured at an average temperature of 20 ° C according to KS L 9016 is 0.017 W / m K to 0.022 W / m K
Method for producing a polystyrene-phenol composite foam.
According to claim 8,
The moisture content of the phenolic resin is greater than 7% by weight and less than 11% by weight
Method for producing a polystyrene-phenol composite foam.
According to claim 8,
The phenolic resin has a reactivity such that when 20g of the curing agent is added to 500g of the phenolic resin and stirred, the highest temperature is 150 ° C. or higher.
Method for producing a polystyrene-phenol composite foam.
According to claim 8,
The diameter of the unexpanded polystyrene beads is 0.25 mm to 2 mm
Method for producing a polystyrene-phenol composite foam.
According to claim 8,
The temperature of the mold is 75 ℃ to 90 ℃
Method for producing a polystyrene-phenol composite foam.

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