KR20170098757A - Foam Article Comprising Multi-Functional Foam Layer And Method For Preparing The Same - Google Patents

Abstract

The present invention relates to a foaming-molded product with enhanced functionality for each layer. Provided is the foaming-molded product which is formed by laminating a resin foamed layer with enhanced thermal insulation properties and a foamed resin layer with enhanced strength and thus has excellent thermal insulation and strength performance. According to the present invention, the foaming-molded product comprises: a first resin foamed layer; and a second resin foamed layer having bending strength higher than the first resin foamed layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an expanded molded article comprising a plurality of functional foam layers,

The present invention relates to a foamed molded article having improved layer-wise functional properties.

Examples of the conventional heat insulating plate include a glass fiber press plate, a polystyrene foam by beads foaming or extrusion, a rigid polyurethane foam, and a polyethylene foam. Among them, the resin foam excluding the glass fiber is lightweight and has thermal conductivity, water resistance, Resistance, and compressibility.

Among these, polystyrene foam called "Styrofoam" is most widely used because of its high economic efficiency.

However, these resin foams, including polystyrene foam, are not satisfactory in terms of workability because it is relatively difficult to perform surface curving or surface roughening in the field, and in many cases the use of wire or anchor is required, so that the workability is also unsatisfactory. Since the bondability with the material is inferior, there is a certain limit in the application area of the construction.

Therefore, for the purpose of improving workability or workability, a composite plate material in which a thin metal plate is attached to one surface of a polystyrene foam and a sand is sandblasted to the other surface, or a glass fiber plate is bonded to one surface of a polystyrene foam And a composite plate in the form of a ceramic plate adhered to the other surface have been proposed. However, the anchor bolt is not satisfactory because it is inferior in economical efficiency and is used for external heat insulation.

On the other hand, a non-combustible inorganic foam using an inorganic filler such as calcium carbonate and zinc oxide as a main material and a vinyl chloride resin as a binder is known. However, in the above-mentioned incombustible inorganic foam, the added weight of the inorganic filler It is impossible to foam by a conventional method because it is used in an excess amount of about 4 to 18 times as much as the weight, so that it requires special equipment for the kneading and foaming molding process and extremely troublesome procedures, The lack of economics of the lightweight non-burning products directly led to the withdrawal from the market.

Therefore, it is urgently required to develop a heat insulating plate having excellent heat insulating property, moisture resistance, mechanical strength and processability, light weight, nonflammable property, particularly excellent bonding property with dissimilar materials and excellent in workability and economy.

United States Patent Number 5000991.

It is an object of the present invention to provide a multilayer foamed molded article having improved layer-specific functionality.

In order to solve the above problems,

A first resin foam layer; And

And a second resin foam layer formed on at least one side of the first resin foam layer and having a flexural strength higher than that of the first resin foam layer.

The present invention also provides a method for producing a resin composition, comprising the steps of: heating a first resin to form a first resin melt;

Mixing the first resin melt with a foaming agent to form a first foamable melt;

Forming a first resin foam layer by foaming while extruding the first foamable melted resin;

Heating the second resin to form a second resin melt;

Mixing the second resin melt with a foaming agent to form a second foamable melt;

Forming a second resin foam layer by foaming while extruding the second foamable melt; And

And a step of bonding the first resin foam layer and the second resin foam layer to each other.

The foamed molded article according to the present invention is formed by laminating a resin foam layer having improved heat insulation property and a resin foamed layer having improved strength, so that excellent heat insulating performance and strength performance can be realized at the same time.

1 is a structural view of an expansion-molded article according to one embodiment.
2 is a structural view of a foamed molded article according to another embodiment.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present invention, the terms "comprising" or "having ", and the like, specify that the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Therefore, the configurations shown in the embodiments described herein are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents And variations.

In the present invention, the term "cell" means a microstructure expanded by foaming in a polymer.

Hereinafter, the foamed molded article according to the present invention will be described in detail.

In the expansion-molded article according to the present invention,

A first resin foam layer; And

And a second resin foam layer formed on at least one side of the first resin foam layer and having a higher bending strength than the first resin foam layer.

In one embodiment, the thermal conductivity of the first resin foam layer according to the present invention may be lower than that of the second resin foam layer. The first resin foam layer exhibits a lower thermal conductivity than the second resin foam layer, so that excellent heat insulating performance can be realized.

In one embodiment, resins of the first resin foam layer and the second resin foam layer according to the present invention may use the same or different kinds of resins. If the resins of the first resin foam layer and the second resin foam layer are the same, the strength of the two foam layers can be controlled by appropriately controlling the density or the expansion ratio of the resin.

In one embodiment, the expansion-molded article according to the present invention is a two-layer structure in which a second resin foam layer and a first resin foam layer are laminated or a second resin foam layer / a first resin foam layer / a second resin foam layer A three-layer structure or a structure in which the second resin foam layer and the first resin foam layer are alternately repeatedly laminated several times.

The foamed molded article of the present invention has a structure in which a first resin foamed layer having reduced thermal conductivity and improved heat insulating performance and a second resin foamed layer having improved bending strength and compressive strength are stacked to realize significantly improved heat insulation and strength performance .

In one embodiment, the second resin foam layer according to the present invention may satisfy the following general formula (1).

[Formula 1]

 X / Y ≥ 1.5

Wherein X represents the flexural strength (N / cm ² ) of the second resin foam layer according to KS M ISO 844 and Y represents the density (kg / m ³⁾ of the second resin foam layer according to KS M ISO 845 ). That is, the bending strength of the second resin foam layer according to the present invention may be at least 1.5 times, 1.5 to 3 times, or 1.6 to 2 times the density of the second resin foam layer. When the ratio of the bending strength and the density of the second resin foam layer satisfies the above range, the strength of the foamed molded article can be effectively improved.

In the general formula 1, X (flexural strength) may be 30 to 350 N / cm ² , and the Y (density) may be 20 to 230 kg / m ³ . Specifically, the flexural strength of the second resin foam layer according to the present invention may be 35 to 300 N / cm ² , 40 to 250 N / cm ² , 50 to 200 or 60 to 100 N / cm ² , To 200 kg / m ³ , 25 to 150 kg / m ³ , 30 to 100 kg / m ³ or 35 to 60 kg / m ³ . When the bending strength and density of the second resin foam layer satisfy the above range, the strength of the foamed molded article can be effectively improved.

In one embodiment, the compressive strength (KS M ISO 844) of the second resin foam layer according to the present invention may be 20-300 N / cm ² . Specifically, the compressive strength may be 25 to 250 N / cm ² , 30 to 200 N / cm ² , 35 to 150 N / cm ² , 40 to 100 N / cm ² or 43 to 70 N / cm ² . When the compression strength of the second resin foam layer is in the above range, the strength of the foamed molded article can be effectively improved. In the case of bead foaming, a method in which a bead-shaped resin is put in a metal mold and foaming is carried out. In the compression test, the bead foamed molded article is liable to cause cracking and granular fracture phenomenon relatively easily between beads and beads . On the other hand, the resin foam layer according to the present invention can realize remarkably excellent compression strength as compared with the case where it is produced by the bead foaming method, by melting the resin and producing it by the extrusion foaming method.

In one embodiment, the thermal conductivity (KS L 9016) of the second resin foam layer may be 0.04 W / mK or less. Specifically, the thermal conductivity of the second resin foam layer may be 0.01 to 0.04 W / mK, 0.013 to 0.038 W / mK, 0.015 to 0.035, or 0.018 to 0.03 W / mK. The foamed molded article according to the present invention includes a resin foamed layer having a thermal conductivity within the above range, so that excellent heat insulating property can be realized.

In one embodiment, the second resin foam layer may comprise a polyester. The polyester resin is not particularly limited as long as it has biodegradability and can retain the physical properties of the polyester and is excellent in softness characteristics and foam forming workability.

The polyester resin mainly used so far is a high molecular weight aromatic polyester resin produced by the condensation polymerization reaction of 1,4-butanediol with terephthalic acid. Here, the high molecular weight polyester may mean a polymer having an intrinsic viscosity [?] Of 0.8 (dL / g) or more. However, the aromatic polyester resin is excellent in physical properties such as high molecular weight, thermal stability and tensile strength, but it is not decomposed in a natural ecosystem after disposal, causing serious environmental pollution problem for a long time.

On the other hand, it is already known that aliphatic polyester has biodegradability. However, conventional aliphatic polyesters have a low melting point due to the flexible structure of the main chain and low crystallinity, are low in thermal stability upon melting, are likely to be thermally decomposed, have a high melt flow index, There is a problem that the use thereof is limited due to poor physical properties such as tear strength. The aliphatic polyester may include, for example, polyglycolide, polycaprolactone, polylactide, and polybutylene succinate.

Specifically, the second resin foam layer may be a polyester. Examples of the second resin foam layer include polyethylene terephthalate (PET), polystyrene (PS), polybutylene terephthalate (PBT), poly Polylactic acid (PLA), polyglycolic acid (PGA), polypropylene (PP), polyethylene (PE), polyethylene adipate (PEA), polyhydroxyalkanoate At least one selected from the group consisting of polyhydroxyalkanoate (PHA), polytrimethylene terephthalate (PTT), and polyethylene naphthalate (PEN). Specifically, polyethylene terephthalate (PET) may be used in the present invention.

In one embodiment, the flexural strength (KS M ISO 844) of the first resin foam layer may be 1 to 50 N / cm ² . Specifically, the flexural strength may be 5 to 45 N / cm ² or 10 to 30 N / cm ² . When the flexural strength of the first resin foam layer is in the above range, the strength of the foamed molded article can be effectively improved and the heat insulating performance can be prevented from deteriorating.

In one embodiment, the compressive strength (KS M ISO 844) of the first resin foam layer may be 1 to 40 N / cm ² . Specifically, the compressive strength may be 5 to 35 N / cm ² or 10 to 30 N / cm ² . When the compressive strength of the first resin foam layer is in the above range, the strength of the foamed molded article can be effectively improved and the heat insulating performance can be prevented from deteriorating. The resin foam layer according to the present invention can realize remarkably excellent compression strength as compared with the case where it is produced by the bead foaming method by melting the resin and producing it by the extrusion foaming method.

In one embodiment, the thermal conductivity (KS L 9016) of the first resin foam layer may be 0.03 W / mK or less. Specifically, the thermal conductivity may be 0.005 to 0.25 W / mK, 0.01 to 0.22 W / mK, or 0.013 to 0.02 W / mK. The first resin foam layer according to the present invention has thermal conductivity in the above-mentioned range, so that excellent heat insulation performance can be realized when the foamed molded article is produced by the foamed molded article.

In one embodiment, the first resin foam layer may comprise polyurethane or polystyrene. Further, the first resin foam layer may comprise a phenolic resin.

In general, the polyurethane resin composition is used for producing foaming products such as leather, elastomer, coating, sealant and the like, and foamed products such as building insulation, shoe window, or automobile interior material. The polyurethane resin composition may be classified into a two-pack type polyurethane resin composition comprising a prepolymer component and a resin component, and a one-pack type polyurethane resin composition comprising a solvent and a resin component. The two-pack type polyurethane resin composition is mainly used for a foam or an elastomer, and the one-pack type polyurethane resin composition is used for coating. Also, the two-pack type polyurethane resin composition can be applied to a shock absorber, and the one-pack type polyurethane resin composition can be applied to interior materials such as vehicle seat, artificial leather for furniture and synthetic leather.

In general, polystyrenes have almost no hygroscopicity, have excellent properties as high-frequency insulating materials, are very light in weight when manufactured from foam, and provide improved physical properties as heat insulating materials and sound absorbing materials.

Phenol resin is a typical thermosetting material. It can be used as a flame retardant material because it generates little flame gas and has excellent self-extinguishing ability. When a phenol resin having excellent flame retardancy is contained in this way, there is an advantage that fire risk of the foamed molded article can be effectively reduced.

In one embodiment, the phenolic resin has a moisture content of 2-12% and a viscosity (cps) at 25 ° C may range from 4000 to 25000. The foamed molded article to which the phenolic resin exhibiting the above-described properties is added has an excellent heat insulating performance.

In one embodiment, the total thickness of the foamed molded article according to the present invention may be from 3 to 60 cm, from 5 to 55 cm, from 10 to 55 cm, or from 15 to 50 cm. In addition, the thickness of each of the first resin foam layer and the second resin foam layer, which are individual layers of the foamed molded article, may be 1 to 40 cm, 3 to 35 cm, or 5 to 25 cm. As a result, it can be seen that the molded foam according to the present invention can achieve properties such as excellent bending strength, compressive strength and heat insulation even with a relatively thin thickness. Therefore, it is possible to reduce the weight of the foamed molded article, and the production cost can be reduced.

In one embodiment, the second resin foam layer of the present invention may have at least 90% of the cells closed cells (DIN ISO4590). This may mean that the measured value of the second resin foam layer according to DIN ISO 4590 is that at least 90% of the cells are closed cells. For example, the closed cell of the second resin foam layer may be 90 to 100% or 95 to 100%. The foamed molded article according to the present invention includes the second papermaking foam layer having the closed cells within the above range, so that excellent heat insulating properties can be realized. As a result, the foamed molded article can be widely used in the construction industry for insulation of a part of a building, for example, a foundation, a wall, a floor and a roof. For example, the number of cells of the foamed molded article may include 1 to 30 cells, 3 to 25 cells, or 3 to 20 cells per mm.

In one embodiment, the first resin foam layer of the present invention may have the same closed cell ratio as the second resin foam layer.

The first resin foam layer and the second resin foam layer according to the present invention can appropriately adjust the ratio of the closed cells and the number of cells in order to realize different strength and adiabatic characteristics.

In one embodiment, the second resin foam layer may be an extruded foam.

Specifically, there are types of foaming methods largely bead foaming or extrusion foaming. In general, the bead foaming is a method of heating a resin bead to form a primary foam, aging the resin bead for a suitable time, filling the resin bead in a plate-shaped or cylindrical mold, heating the same again, and fusing and forming the product by secondary foaming.

On the other hand, the extrusion foaming can simplify the process steps by heating and melting the resin and continuously extruding and foaming the resin melt, and it is possible to mass-produce, and the cracks, Development and the like can be prevented, and more excellent bending strength and compressive strength can be realized.

Hereinafter, a method for producing an expanded molded article according to the present invention will be described in detail.

In the method for producing an expansion-molded article according to the present invention,

Heating the first resin to form a first resin melt;

Mixing the first resin melt with a foaming agent to form a first foamable melt;

Forming a first resin foam layer by foaming while extruding the first foamable melted resin;

Heating the second resin to form a second resin melt;

Mixing the second resin melt with a foaming agent to form a second foamable melt;

Forming a second resin foam layer by foaming while extruding the second foamable melt; And

And bonding the first resin foam layer and the second resin foam layer to each other.

Specifically, the resin may be heated at a temperature of 200 ° C or higher to prepare a resin melt, and a foaming agent may be mixed into the resin melt to form a foamable melt.

Here, the resin may be the same as that described above, and the blowing agent may include a thermally decomposing foaming agent, a volatile foaming agent, or a mixture thereof. As the pyrolytic foaming agent, for example, an inorganic foaming agent containing sodium hydrogencarbonate, an azo compound, a nitroso compound, a hydrazine compound and the like may be included. The volatile foaming agent may include, for example, an organic gas such as carbon dioxide gas or nitrogen, an organic foaming agent such as propane, butane, hexane, methane and the like. At this time, when a pyrolytic foaming agent or a volatile foaming agent is used, there is an advantage that a foamed molded article of high magnification can be obtained.

When the first and second foamable melts are co-extruded and expanded by foaming, there is no need for a separate adhesive or bonding step for bonding the first and second resin foam layers, thereby improving the efficiency of the foamed molded product manufacturing process It is effective.

In the step of bonding the first resin foam layer and the second resin foam layer, the bonding may be performed by melting or bonding the bonding surfaces of the first resin foam layer and the second resin foam layer, or performing the thermal bonding method. The bonding may be performed by applying a conventional adhesive or the like to the bonding surface of the first resin foam layer and the second resin foam layer and bonding them to each other. The adhesive may be a film-type adhesive having a flame-retardant rating. Specifically, in the present invention, the first resin foam layer and the second resin foam layer can be adhered to each other through the thermal bonding method. In this case, harmful components of the resin foam layer can be removed due to heat, .

The foamed molded article according to the present invention is produced by adhering two or more layers of a first resin foam layer having excellent heat insulating properties and a second resin foamed layer having excellent strength characteristics alternately to obtain an expanded molded article It is possible to manufacture.

In one embodiment, the first and second resin foam layers according to the present invention may further have a hydrophilizing function, a waterproof function, a flame retarding function, or an ultraviolet shielding function, and may further comprise a surfactant, a UV- May further comprise at least one functional additive selected from the group of water repellents, cell size extenders, infrared attenuators, plasticizers, fire retardants, pigments, elastic polymers, extrusion aids, antioxidants, fillers, have.

The surfactant is not particularly limited, and examples thereof include anionic surfactants (e.g., fatty acid salts, alkylsulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfosuccinic acid salts and polyoxyethylene alkylsulfuric acid ester salts) , Nonionic surfactants (for example, polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, polyoxyethylene derivatives, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, (E.g., alkylamine salts, quaternary ammonium salts, alkylbetaines, amine oxides, etc.), and water-soluble polymers such as polyoxyethylene alkylamines and alkylalkanolamides), cationic and amphoteric surfactants Or protective colloids (e.g., gelatin, methylcellulose, hydroxyethylcellulose, Polyoxyethylene-polyoxypropylene block copolymer, polyacrylamide, polyacrylic acid, polyacrylic acid salt, sodium alginate, polyvinyl alcohol partial saponification, etc.), and the like have.

The waterproofing agent is not particularly limited and includes, for example, silicone, epoxy, cyanoacrylate, polyvinyl acrylate, ethylene vinyl acetate, acrylate, polychloroprene, polyurethane and polyester resins , A mixture of polyol and polyurethane resin, a mixture of acrylic polymer and polyurethane resin, a polyimide, and a mixture of cyanoacrylate and urethane.

The flame retardant is not particularly limited and may include, for example, a bromine compound, a phosphorus or phosphorus compound, an antimony compound and a metal hydroxide. The bromine compound includes, for example, tetrabromobisphenol A and decabromodiphenyl ether, and the phosphorus or phosphorus compound includes an aromatic phosphoric acid ester, an aromatic condensed phosphoric acid ester, a halogenated phosphoric acid ester, and the like, and the antimony compound Antimony trioxide, antimony pentoxide, and the like. Examples of the metal element in the metal hydroxide include aluminum (Al), magnesium (Mg), calcium (Ca), nickel (Ni), cobalt (Co), tin (Sn), zinc (Zn) ), Iron (Fe), titanium (Ti), boron (B), and the like. Of these, aluminum and magnesium are preferable. The metal hydroxide may be composed of one kind of metal element or two or more kinds of metal elements. For example, metal hydroxides composed of one kind of metal element may include aluminum hydroxide, magnesium hydroxide, and the like.

The ultraviolet screening agent is not particularly limited and may be, for example, an organic or inorganic ultraviolet screening agent. Examples of the organic ultraviolet screening agent include p-aminobenzoic acid derivatives, benzylidene camphor derivatives, cinnamic acid derivatives, Benzotriazole derivatives, and mixtures thereof. Examples of the inorganic ultraviolet screening agent may include titanium dioxide, zinc oxide, manganese oxide, zirconium dioxide, cerium dioxide, and mixtures thereof.

Specifically, the foamed molded article according to the present invention can be produced by an extrusion foaming method which can be continuously produced, and the extrusion foaming process is carried out at about 200 to 250 ° C, and a functional additive To form a functional coating layer. At this time, the functional coating layer is coated with a functional additive composed of an inorganic material or an organic material, and in case of an organic material, the boiling point may be 250 ° C or more. By using an organic material having a boiling point of 250 DEG C or more, deterioration of the physical properties of the functional coating layer can be prevented.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited by the following description.

Example  One

In order to produce a foamed molded article having a three-layer structure, the first resin foam layer was made of a polystyrene (XPS) foam with a thickness of 20 mm and the second resin foam layer with a PET foam with a thickness of 30 mm.

First, 100 phr of a polystyrene resin, 0.2 phr of titanium oxide and 1 phr of talc were mixed and heated to 220 DEG C to prepare a polystyrene foam (XPS). Then, a resin melt was prepared, and HCFC-22 and carbonic acid After the gas was introduced, the resin melt prepared by mixing was passed through a second extruder and cooled to 120 ° C. The cooled resin melt was extruded and foamed while passing through a die to form a first resin foam layer.

Then, the PET resin was dried at 130 ° C to remove moisture, and then the water extruded was washed with 100 phr of PET resin, 1 phr of PMDA, 1 phr of talc, 1 phr of Irganox (IRG 1010) 0.1 phr, and the mixture was heated to 280 ° C to prepare a resin melt. Carbon dioxide gas as a foaming agent was added thereto, and the mixture was thoroughly mixed. The resin melt thus prepared was sent to a second extruder and cooled to 220 ° C. The cooled resin melt was extruded and foamed while passing through a die to form a second resin foam layer.

Then, the first resin foam layer and the second resin foam layer were combined using an adhesive.

1 shows the structure of an expanded molded article produced by the above method. The structure of a foamed molded article having a three-layered structure in which the second resin foamed layers 20 and 21 and the first resin foamed layer 10 are alternately laminated Can be confirmed.

Example  2

Was prepared in the same manner as in Example 1, except that the first resin foam layer was produced using polyurethane.

The first resin foam layer was prepared by uniformly mixing 1 phr of a polyol, 0.1 phr of a catalyst, 0.1 phr of diethanolamine, 1 phr of a silicone antifoam and 4.6 phr of water as a foaming agent, followed by the addition of a polyisocyanate (Cosmonate T-80) 56 phr. The mixture was stirred for 5 to 7 seconds, rapidly poured into a mold, immediately foamed, and cured at 80 DEG C for 20 minutes.

Example  3

Was prepared in the same manner as in Example 1 except that the first resin foam layer was prepared using phenol.

The phenol foam (PF), which is the first resin foam layer, was blended with 100 phr of phenol resin, 2 phr of foam stabilizer (silicone siloxane), 20 phr of plasticizer (TCPP) and 5.5 phr of foaming agent HCF, .

Comparative Example  One

Polyethylene terephthalate (PET) resin was dried at 130 占 폚 to remove water. In the first extruder, 100 phr of PET resin, 1 phr of PMDA, 1 phr of talc, and 0.1 phr of Irganox (IRG 1010) And the mixture was heated to 280 ° C. to prepare a resin melt. Carbon dioxide gas as a foaming agent was added thereto, and the mixture was thoroughly mixed. The resin melt was sent to a second extruder and cooled to 220 ° C. The cooled resin melt was extruded and foamed through a die to produce a 5 mm thick PET foam.

Comparative Example  2

100 phr of polystyrene resin, 0.2 phr of titanium oxide and 1 phr of talc were mixed and heated to 220 DEG C to prepare a resin melt. Then, HCFC-22 and carbonic acid gas were introduced as a foaming agent, And sent to a second extruder to cool to 120 ° C. The cooled resin melt was extruded and foamed while passing through a die to prepare a polystyrene resin foam (XPS) having a thickness of 5 mm.

Comparative Example  3

After mixing 56 phr of a polyisocyanate (Cosmonate T-80) for 5 to 7 seconds, 100 phr of polyol, 0.1 phr of catalyst, 0.1 phr of diethanolamine, 1 phr of silicone antifoam, and 4.6 phr of water as foaming agent were uniformly mixed for 1 minute. After stirring, the mixture was immediately poured into a mold, immediately foamed, and then cured at 80 DEG C for 20 minutes to prepare a polyurethane (PU) foam having a thickness of 5 mm.

Comparative Example  4

Phenol resin (PF) was prepared by blending 100 phr of a phenol resin, 2 phr of a foam stabilizer (silicone siloxane), 20 phr of a plasticizer (TCPP) and 5.5 phr of a foaming agent HCF and then curing the mixture with 33 phr of a curing agent.

Experimental Example

The foamed molded articles prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured for heat insulation, compressive strength, flexural strength and density. The measurement method is described below, and the results are shown in Table 1 below.

1) Insulation measurement

Thermal conductivity was measured under KS L 9016 conditions.

2) Compressive strength measurement

The compressive strength was measured under KS M ISO 844 conditions.

3) Measurement of flexural strength

Flexural strength was measured under KS M ISO 844 conditions.

5) Density measurement

The density was measured under KS M ISO 845 conditions.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 The first resin foam layer XPS PU PF PET XPS PU PF The second resin foam layer PET PET PET Thermal conductivity
(W / mK) 0.03 0.026 0.021 0.034 0.029 0.024 0.019 Compressive strength
(N / cm ² ) 55 50 45 60 30 20 5 Flexural strength
(N / cm ² ) 80 75 65 89 35 30 10 density
(kg / m ³ ) 50 50 50 60 40 40 40 1
(Flexural strength / density) 1.6 1.5 1.3 1.5 0.9 0.75 0.25

As shown in Table 1, in Examples 1 to 3 according to the present invention, the thermal conductivity was 0.03 W / mK or less, the flexural strength was 65 N / cm ² or more, I could. On the other hand, in Comparative Example 1, although the bending strength was excellent, the thermal conductivity was 0.034 W / mK and the thermal conductivity was relatively low. In Comparative Examples 2 to 4, the thermal conductivity was low, but the bending strength was 35 N / cm ² or less And the strength was remarkably lowered.

Therefore, it has been confirmed that the foamed molded body according to the present invention can simultaneously realize improved heat insulation and flexural strength by laminating a first resin foamed layer having improved heat insulation property and a second resin foamed layer having improved bending strength.

100, 200: expanded molded article
10, 11: a first resin foam layer
20, 21, 22: a second resin foam layer

Claims (14)

A first resin foam layer; And
And a second resin foam layer formed on at least one side of the first resin foam layer and having a flexural strength higher than that of the first resin foam layer.
The method according to claim 1,
And the thermal conductivity of the first resin foam layer is lower than that of the second resin foam layer.
The method according to claim 1,
And the second resin foam layer satisfies the following general formula (1).
[Formula 1]
X / Y ≥ 1.5
Wherein X represents the flexural strength (N / cm ² ) of the second resin foam layer according to KS M ISO 844 and Y represents the density (kg / m ³⁾ of the second resin foam layer according to KS M ISO 845 ).
The method of claim 3,
Wherein X is 30 to 350 N / cm ² , and Y is 20 to 230 kg / m ³ .
The method according to claim 1,
And the compression strength (KS M ISO 844) of the second resin foam layer is 20 to 300 N / cm ² .
The method according to claim 1,
And the thermal conductivity (KS L 9016) of the second resin foam layer is 0.04 W / mK or less.
The method according to claim 1,
Wherein the second resin foam layer comprises polyester.
The method according to claim 1,
And the flexural strength (KS M ISO 844) of the first resin foam layer is 1 to 50 N / cm ² .
The method according to claim 1,
And the compression strength (KS M ISO 844) of the first resin foam layer is 1 to 40 N / cm ² .
The method according to claim 1,
Wherein the first resin foam layer has a thermal conductivity (KS L 9016) of 0.03 W / mK or less.
The method according to claim 1,
Wherein the first resin foam layer comprises polyurethane or polystyrene.
The method according to claim 1,
Wherein at least 90% of the cells of the second resin foam layer are closed cells (DIN ISO4590).
The method according to claim 1,
Wherein the second resin foam layer is an extruded foam.
Heating the first resin to form a first resin melt;
Mixing the first resin melt with a foaming agent to form a first foamable melt;
Forming a first resin foam layer by foaming while extruding the first foamable melted resin;
Heating the second resin to form a second resin melt;
Mixing the second resin melt with a foaming agent to form a second foamable melt;
Forming a second resin foam layer by foaming while extruding the second foamable melt; And
The method for manufacturing an expansion-molded article according to claim 1, comprising the step of adhering the first resin foam layer and the second resin foam layer.

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