JPH11310619A - Polyurethane foam, its production, insulating material and insulating box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane foam having a low density and excellent in insulation properties, strength and dimensional stability without using a fluorocarbon-based foaming agent by including a polyol, an organic polyisocyanate, a foam stabilizer, polymer hollow particles and the like. SOLUTION: The objective foam is obtained by foaming a mixture comprising (A) a polyol (e.g. a sucrose-based polyetherpolyol), (B) an organic polyisocyanate (e.g. diphenylmethanediisocyanate), (C) a foam stabilizer, e.g. a linear or branched polyether/siloxane compound, (D) a catalyst (e.g. triethylamine), (E) a foaming agent and preferably (F) polymer hollow particles (a particulate polymer having vacant part in the interior) having 1-100 μm particle size. Preferably, the component C of 1-10 pts.wt. and the component D of 0.5-10 pts.wt. are included in the component A of 100 pts.wt., and 1-30 wt.% component F based on the whole amount of the foam is included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyurethane foam and a method for producing the same, a heat insulating material using such a polyurethane foam, and a box comprising such a polyurethane foam or a heat insulating material.

[0002]

2. Description of the Related Art Equipment for maintaining the inside at a predetermined temperature in response to a change in ambient temperature, such as a refrigerator, a freezer,
Equipment such as refrigerated freezer cases, warm storage, tanks for maintaining temperature such as for cold or hot water, containers and piping, and vehicles, aircraft and ships equipped with these facilities,
In addition, foamed insulation materials are widely used in buildings such as wall materials, underfloor materials and roofing materials, and among such foamed insulation materials, polyurethane foam is preferable because of its excellent heat insulation and productivity. Is widely used today.

[0003]

As a foaming agent for such a polyurethane foam for a heat insulating material, a CFC-based foaming agent such as chlorofluorocarbon (hereinafter referred to as CFC) or hydrofluorochlorocarbon (hereinafter referred to as HCFC) has been used for many years. Have been used. However, these CFC-based gases are considered to be major factors in destruction of the ozone layer and global warming, and the use of CFCs and / or HCFCs is considered to have an adverse effect on the environment. There is an urgent need in the art to replace blowing agents.

For this reason, a method using a low-boiling hydrocarbon, such as cyclopentane, or water or a carboxylic acid compound, such as cyclopentane, which does not destroy the ozone layer and has relatively little effect on global warming, has been studied as a foaming agent for the polyurethane foam. It is being adopted. When water or a carboxylic acid compound is used as a foaming agent, the water or the carboxylic acid compound reacts with the organic isocyanate to generate carbon dioxide gas, so that the carbon dioxide gas can foam the polyurethane foam.

[0005] By the way, foamed heat insulating materials are also required to have good heat insulating properties from the viewpoint of energy saving. In order to impart good heat insulating properties to the polyurethane foam, it is important to lower the gas thermal conductivity of the gas in the foam cells. Therefore, a foaming agent that generates a gas having a low gas thermal conductivity is used. An effective means is to fill the foam cells with the gas.

In this regard, CF, which has been frequently used in the past,
Compared with CFC-based gases such as C and HCFCs, hydrocarbons and carbon dioxide based on hydrocarbon-based blowing agents, which have been increasingly adopted in recent years, have higher gas thermal conductivity. Therefore, when hydrocarbons and carbon dioxide gas are used for foaming the polyurethane foam, it cannot be denied that the performance in terms of heat insulation is somewhat inferior to the case where a CFC-based foaming agent is used.

[0007] In particular, when carbon dioxide is used as the gas in the foam bubble, the carbon dioxide has a higher gas thermal conductivity than the hydrocarbon-based gas, so that the heat insulating property is inferior to the hydrocarbon-based gas. Can be

Therefore, in order to prevent a decrease in heat insulation due to carbon dioxide gas in a method of generating carbon dioxide gas in the step of foaming the foam, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 8-198996, bubbles in There is a method of adsorbing and removing carbon dioxide gas remaining on the carbon dioxide with a carbon dioxide adsorbent. In this method, an adsorbent made of zeolite or the like is preliminarily mixed in a raw material, and foam is foamed with carbon dioxide gas and hydrocarbons. After a polyurethane foam is formed, carbon dioxide gas is adsorbed by the adsorbent and removed. In this method, the foam cells are filled with only hydrocarbons, and thus the polyurethane foam obtained can be improved in heat insulation performance.

However, in the above-mentioned method of adsorbing carbon dioxide with an absorbent, the foam is foamed and then formed, and as a result of adsorbing carbon dioxide in the foam bubbles, the total pressure of the gas in the bubbles is reduced. The pressure is reduced by a pressure equivalent to the partial pressure of the carbon dioxide removed by adsorption.

[0010] Accordingly, the polyurethane foam tends to shrink under the atmosphere of atmospheric pressure due to a decrease in the total pressure of the gas in the cells. Therefore, when the dimensional stability of the polyurethane foam is to be maintained, the density of the foam is set to a high value. I needed to.

There is also a method of forming a polyurethane foam by using only carbon dioxide gas generated by the reaction between an organic isocyanate and water or a carboxylic acid compound for foaming. When the method disclosed in Japanese Patent Application Laid-Open No. 8-198996 is applied to such a method, carbon dioxide in the foam cells is completely adsorbed and removed. There is also a problem that the density of the foam must be set higher in order to prevent the foam from shrinking.

Accordingly, the present invention has been made in view of the above problems, and has as its main object the protection of the global environment. Even when carbon dioxide gas generated by the reaction between polyisocyanate and water or a carboxylic acid compound is used as a foaming agent, a high-quality heat insulating material having excellent heat insulating performance, strength, and dimensional stability at low density,
An object of the present invention is to provide a heat-insulating box body filled with the heat-insulating material.

[0013]

SUMMARY OF THE INVENTION In one aspect, the present invention provides a polyurethane foam formed by foaming a mixture comprising a polyol, an organic polyisocyanate, a foam stabilizer, a catalyst, a foaming agent, and polymer hollow particles. I will provide a.

In the polyurethane foam of the present invention,
The blowing agent can be at least one compound selected from the group consisting of hydrocarbons, water and carboxylic acid compounds, and cyclopentane can be used as the hydrocarbon.

In the polyurethane foam of the present invention,
The outer shell of the polymer hollow particles can be made of a thermoplastic resin, and the thermoplastic resin is selected from the group consisting of ethylene, propylene, styrene, vinyl chloride, vinylidene chloride, vinyl acetate, acrylate, and acrylonitrile. It may be a homopolymer of the selected compound or a copolymer of at least two compounds.

In the polyurethane foam of the present invention,
The softening temperature of the thermoplastic resin constituting the outer shell of the polymer hollow particles is preferably 150 ° C. or lower. The hollow polymer particles preferably contain a hydrocarbon having a boiling point of 10 ° C. or lower.

In another aspect, the present invention is characterized in that the polyurethane foam contains polymer hollow particles in a dispersed state. In the polyurethane foam of the present invention, the content of the hollow polymer particles can be 1 to 30% by weight, preferably 3 to 20% by weight based on the weight of the entire polyurethane foam.

The particle size of the hollow polymer particles contained in the polyurethane foam of the present invention is preferably from 1 to 1.
It can be in the range of 00 μm, more preferably 10 to 50 μm.

In another aspect, the present invention provides a mixture comprising a polyol, an organic polyisocyanate, a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles,
A method for producing a polyurethane foam by foaming the mixture is provided.

The present invention provides, in yet another aspect,
Provided is a method for producing a polyurethane foam by mixing a polyol system containing a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles dispersed therein, and an organic polyisocyanate system.

The present invention provides, in still another aspect,
A heat insulator comprising a polyurethane foam as described above is provided.

The present invention, in yet another aspect, comprises:
An outer box, an inner box, and a box having a gap between the outer box and the inner box, the box including the polyurethane foam or the heat insulating material as described above in the gap. provide.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyurethane foam of the present invention is characterized in that a conventional polyurethane foam contains specific polymer hollow particles as defined in the present invention. Accordingly, with respect to the types and compositions of raw materials generally used for producing polyurethane foams, such as polyols, organic polyisocyanates, foam stabilizers, catalysts and foaming agents, those used for conventional polyurethane foams Can be the same as Further, the polyurethane foam of the present invention may further contain, as necessary, a chain extender, a crosslinking agent, a filler, a flame retardant, an antioxidant, an ultraviolet absorber, a hydrolysis inhibitor, and a coloring agent. Can also be included.

In the present invention, the organic polyisocyanate means a compound having two or more isocyanate groups in one molecule. Such compounds include, for example, diphenylmethane diisocyanate (hereinafter referred to as MDI), polymeric MDI, toluene diisocyanate (hereinafter referred to as TDI), hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, phenylene diisocyanate, dimethyl diphenyl diisocyanate, tetramethylene diisocyanate ,
Various compounds such as isophorone diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate can be used alone or in combination of two or more.

Further, for example, a compound which is an adduct of a compound having a plurality of active hydrogen groups in one molecule and two or more molecules of di- or tri-isocyanate, or a di-, tri- or isocyanate is polymerized to a degree of dimer, trimer or oligomer. Compounds having a relatively high molecular weight having two or more isocyanate groups per molecule, for example, "Coronate (registered trademark) L (manufactured by Nippon Polyurethane)" may also be used as the organic polyisocyanate. it can.

In the present invention, examples of the polyol component include glycerin, trimethylolpropane, pentaerythritol, ethylenediamine, triethanolamine, triethylenediamine, tolylenediamine,
Polyether polyol compounds obtained by adding one or more molecules of epoxide groups such as ethylene oxide and propylene oxide to active hydrogen compounds such as diphenylmethane diamine, methyl glycoside, sorbitol, and soucrose, and polyfunctional carboxylic acid compounds such as phthalic acid And a polyester polyol compound obtained by polycondensation of a polyfunctional hydroxy compound, or a mixture thereof.

The organic polyisocyanate is based on one hydroxyl group contained in the polyol and water (if present).
0.8 to 1.4 isocyanate groups, preferably 1.0
It is preferable that the number be within the range of 1.2.

The foam stabilizer regulates the size of cells during foaming and improves the stability. For example, a foam stabilizer can be used by selecting from linear and branched polyether / siloxane compounds. it can. Foam stabilizer is polyol 1
1 to 10 parts by weight, preferably 2 to 100 parts by weight
It can be used in the range of 5 parts by weight.

Examples of the catalyst include various amine compounds such as monoamines, diamines, triamines, cyclic amines, alcohol amines and ether amines, for example, triethylamine, tripropylamine, triisopropanolamine, tributylamine. , Trioctylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetra Methylpropylenediamine, N, N, N ', N'-tetramethylbutanediamine, N,
N, N ', N'-tetramethyl-1,3-butanediamine,
N, N, N ', N'-tetramethylhexamethylenediamine, bis [2- (N, N-dimethylamino) ethyl] ether, N, N-dimethylcyclohexylamine,
N, N ', N ", N" -pentamethyldiethylenetriamine,
Triethylenediamine, triethylenediamine, trimethylaminoethylpiperazine, N, N-dialkylpiperazine, and organotin compounds such as dibutyltin dilaurate can be used. The amount of the catalyst to be added is usually 0.1 to 100 parts by weight of the polyol component.
It is 5 to 10 parts by weight, preferably 1 to 5 parts by weight.

In the present invention, the hollow polymer particles are:
A particulate polymer having a space therein, for example, having a polymer outer shell (so-called shell) and having at least one space therein. The thickness of the outer shell part of the polymer hollow particles is such that if a space can be secured inside the polymer hollow particles,
It can include thin to thick. The internal space may be partitioned into two or more cells by a polymer wall. The internal space may contain a substance other than the polymer forming the hollow particles, and the substance may be a gas or a liquid depending on conditions, and may include a paste or a solid in some cases.

The outer shell portion of the hollow polymer particles is not particularly limited as long as it can hold gas inside, but is preferably formed of a thermoplastic resin. In that case, the thermoplastic resin preferably has a softening temperature of 150 ° C. or less.

Examples of such thermoplastic resins include homopolymers such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylate, acrylonitrile, and two or more of these. And copolymers obtained by combining the above.

Generally, the particle size of the hollow polymer particles is preferably small for uniform dispersion in the polyurethane foam, and improvement in the heat insulating performance when the polyurethane foam is formed can be expected. Usually, 1 to 1
Polymer hollow particles having a particle size in the range of 00 μm are used.

The space inside the polymer hollow particles is filled with a substance that is a gas at atmospheric pressure and normal temperature. This gas is preferably a substance having a boiling point of 10 ° C. or less at atmospheric pressure, particularly a hydrocarbon. The kind of such a gas is not particularly limited, but as the gas having a lower gas thermal conductivity is used, the heat insulation performance of the obtained polyurethane foam is improved. In addition, the higher the vapor pressure of the gas, the more effectively a polyurethane foam having a low density and excellent heat insulation performance, strength and dimensional stability can be formed.
Such gases include, for example, ethane, propane,
Two or more gases selected from the group consisting of hydrocarbons such as butane and isobutane, and rare gases such as argon, xenon and krypton, alone or on condition that the mixture does not have any other adverse effect. Can be used.

A thermoplastic resin having a softening temperature of 150 ° C. or less (preferably 70 to 150 ° C.) is used for the outer shell of the polymer hollow particles, and a substance having a boiling point of 10 ° C. or less at atmospheric pressure is contained inside the polymer hollow particles. By adopting a configuration that includes, since the polymerization reaction between the organic polyisocyanate and the polyol is an exothermic reaction, the internal temperature of the reaction system during the polymerization reaction may be local, for example, 70 to 170 ° C., particularly The temperature may rise to about 80 to 120 ° C., and the volume of gas inside the polymer hollow particles expands, and the thermoplastic resin of the outer shell of the polymer hollow particles softens to some extent, so that the polymer hollow particles expand. For example, it becomes spherical and has a maximum volume allowed by the thermoplastic resin constituting the outer shell. Therefore, in this state, the hollow polymer particles themselves have a lower density.

The outer surface of the thermoplastic resin constituting the outer shell of the hollow polymer particles is in a softened state during the above-mentioned foaming process, and is preferably being produced by polymerization of a polyol and an organic polyisocyanate. It can adhere to the polyurethane and integrate with the resulting polyurethane foam.

After this foaming step, the temperature of the polyurethane foam and the hollow polymer particles is lower than the temperature during the foaming, but the outer shell of the hollow polymer particles has a lower limit of the softening temperature, for example, 70 ° C. or less. When the temperature rises, the resin hardens to form a hard shell, and the hollow polymer particles can maintain a state of occupying the same volume in the formed polyurethane foam.

In the polyurethane foam of the present invention, a blowing agent such as a hydrocarbon or water or a carboxylic acid compound which is usually used is also used. The hydrocarbon or carbon dioxide gas generated by these blowing agents is also used as the polyurethane foam. Exists in the air bubbles. Therefore, since the inside of the obtained polyurethane foam includes a normal cell portion formed by a foaming agent and a space inside the polymer hollow particles as a space occupied by the gas, it is further more than a normal polyurethane foam. A polyurethane foam having low density and improved heat insulation performance can be formed.

In a conventional polyurethane foam, the internal bubbles shrink with a decrease in temperature, and the dimensions of the entire polyurethane foam also shrink, but the polymer hollow particles of the present invention have an outer shell portion. Since the maximum volume that can be held in the foaming step can be substantially maintained inside the polyurethane foam even after the constituent polymer is cured, by using such polymer hollow particles, the polymer hollow particles can be used. Depending on the proportion of the foam, the proportion of the bubbles that shrink as the temperature decreases in the entire foam can be reduced,
Changes in the dimensions of the resulting foam can also be kept to a minimum. Therefore, the polyurethane foam of the present invention has good dimensional stability.

The polymer hollow particles used in the present invention include, for example, emulsion polymerization of a hydrocarbon enclosed therein and a thermoplastic polymer monomer constituting the outer shell under the condition that the hydrocarbon is a liquid. Can be used. Depending on the combination of the type of the polymer in the outer shell and the type of hydrocarbon in the inner shell, such microcapsules can be formed by microencapsulation and then maintained at a temperature relatively lower than the softening temperature of the polymer. Hydrogen can be present in a liquid state, or, after microencapsulation, by quenching under the temperature conditions at which the polymer softens, the hydrocarbons inside are vaporized and relatively spherical. Particles having an outer shell of the following shape. Therefore,
In the space inside the hollow particles, a part may exist as a gas and another part may exist as a liquid.

Commercially available polymer hollow particles can also be used. Specific examples of such polymer hollow particles include "Matsumoto Microsphere (registered trademark) F-20" commercially available from Matsumoto Yushi Seiyaku Co., Ltd., and Nippon Ferrite in Japan.
`` EXPANSEL '' commercially available from Co., Ltd.
(Registered trademark) 551DU ".

Further, the polyurethane foam of the present invention comprises
Preferably 1 to 100 μm, more preferably 10 to 50
Since polymer hollow particles having a particle size in the range of μm are dispersed therein, the polymer hollow particles are dispersed and present in the polyurethane foam in a state of independent cells,
The strength of the obtained urethane foam is also improved.

The polyurethane foam of the present invention basically comprises a polyol, an organic polyisocyanate, a foam stabilizer,
It can be produced by forming a mixture comprising a catalyst, a blowing agent and polymer hollow particles, and foaming the mixture. In particular, a polyol system containing a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles dispersed therein is first prepared, and in this state, the polymer hollow particles are homogeneously dispersed throughout the polyol system by sufficiently stirring the system. Can be done. The polyurethane foam of the present invention can be produced by mixing the polyol system and the organic polyisocyanate system thus obtained.

The polyurethane foam of the present invention as described above has a lower density than a conventional polyurethane foam and has better heat insulating performance, strength and dimensional stability, and can be used for its properties. In particular, it can be used as a heat insulating material, a sealing material, a caulking material, an insulating material, a cushioning material, a structural material or a coating material that can be a substitute for metal, and the like.

In particular, when the polyurethane foam is polymerized or after the foam is formed, it is processed into various shapes so that the desired shape can be obtained with low density and excellent heat insulation, strength and dimensional stability. It can be used as a material. For example, when foaming the polyurethane foam of the present invention, by appropriately adopting an application method such as an injection method, a casting method, or a spraying method, it surrounds a member having a complicated shape or fills an internal space. It can also be used as thermal insulation. Therefore, for example, the space between the outer box and the inner box, such as a box, can be filled, so that a light-weight, heat-insulating box having excellent heat insulation performance can be obtained.
The heat insulating material and the heat insulating box of the present invention can be used for various applications as described in the section of the prior art.

[0046]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these embodiments.

A polyurethane foam was formed using the recipe shown in Table 1. In these examples, the polyol is a mixture of a shoe-closed polyether polyol and an ethylenediamine-based polyether polyol having a total hydroxyl value of 460 mgKOH / g, and the foam stabilizer is Nippon Unicar Co., Ltd. Made L-5
340, Kaolyzer No. manufactured by Kao Corporation as a catalyst.
31 is an organic polyisocyanate having an amine equivalent of 1
35 polymeric MDIs were used.

In the examples shown in Table 1, the hollow polymer particles B are made of a vinylidene chloride / acrylonitrile copolymer having an outer shell having a softening temperature of 70 to 75 ° C., and have a particle size of 10 to 10 containing isobutane. 20 μm, heat-expandable polymer hollow particles having a true specific gravity of 1.1 g / cc (Matsumoto Microsphere F-2 manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
0) was used. Further, as the polymer hollow particles A,
The polymer hollow particles having a particle size of 80 to 100 μm obtained by subjecting the above polymer hollow particles B to a heat treatment at about 100 ° C. for 10 minutes were used.

As the blowing agent, cyclopentane or carbon dioxide gas generated by the reaction between water and isocyanate was used. The above-mentioned raw materials are mixed and stirred in the number of parts shown in Table 1, foamed by a high-pressure foaming machine, and filled in the gap of the heat-insulated box having a gap between the outer box and the inner box. I got

A polyurethane foam was cut out from the heat-insulating box thus obtained, and its core density, thermal conductivity, compressive mechanical strength, wet heat dimensional stability, and low temperature dimensional stability were examined. The measurement results are shown in Table 1. here,
The thermal conductivity was measured by AUTO-Λ manufactured by Eiko Seiki Co., Ltd. The compressive mechanical strength was obtained by measuring the strength in the thickness direction of a test piece having a length of 50 mm, a width of 50 mm and a thickness of 30 mm at a test speed of 10 mm / min using an autograph manufactured by Shimadzu Corporation. Dimensional stability is 75 mm long x 50 mm wide x 30 thickness
mm test piece was prepared and subjected to wet heat conditions (70 ° C, 90 RH).
%), And the rate of change in volume of the test piece when left for 48 hours under low-temperature conditions (−20 ° C.).

[0051]

[Table 1]

Comparative Examples 1 and 3 show the case where no polymer hollow particles were added. In these cases, the density of the polyurethane foam could not be reduced. Comparative Examples 2 and 4 show cases where the density of the polyurethane foam was reduced by increasing the amount of cyclopentane or water as a blowing agent. In these cases, the dimensional stability and compressive strength of the polyurethane foam were significantly reduced. On the other hand, Examples 1 to 6 of the present invention
In the above, a polyurethane foam having a low density and excellent in heat insulation performance, strength and dimensional stability could be obtained.

[0053]

According to the present invention, a polyol, an organic polyisocyanate,
The polyurethane foam of the present invention formed by foaming a mixture comprising a foam stabilizer, a catalyst, a foaming agent, and polymer hollow particles has a higher effect by adding polymer hollow particles than in the case where no polymer hollow particles are added. With a low density, more excellent heat insulating performance, strength and dimensional stability can be secured.

The use of at least one compound selected from the group consisting of hydrocarbons, water and carboxylic acid compounds as a foaming agent for the polyurethane foam, and the use of cyclopentane as the hydrocarbon in particular can reduce ozone layer depletion. It is possible to avoid the use of Freon-based gas that has a negative effect on global warming.

By forming the outer shell of the hollow polymer particles with a thermoplastic resin, the shape of the hollow polymer particles can be changed as desired. The thermoplastic resin, ethylene, propylene, styrene, vinyl chloride, vinylidene chloride, vinyl acetate, a homopolymer of a compound selected from the group consisting of acrylates and acrylonitrile or a copolymer of at least two compounds, or heat By using a plastic resin having a softening temperature of 150 ° C. or lower, a process of expanding the foam during foaming to change the shape of the polymer hollow particles can be easily performed.

By forming the outer shell of the polymer hollow particles as described above and including a hydrocarbon having a boiling point of 10 ° C. or less inside the polymer hollow particles, a hollow state can be ensured during normal use. .

The polyurethane foam contains the polymer hollow particles in a dispersed state, and the content of the polymer hollow particles is 1 to 30% by weight, preferably 3 to 20% by weight based on the weight of the entire polyurethane foam. As a result, the polyurethane foam contains the polymer hollow particles as a whole, preferably uniformly, so that a low specific gravity and good heat insulating properties, strength, and dimensional stability can be achieved throughout the polyurethane foam.

By setting the particle size of the hollow polymer particles to preferably 1 to 100 μm, more preferably 10 to 50 μm, the range of the quantitative ratio of adding the hollow polymer particles to the polyurethane foam can be increased. By dispersing the polymer hollow particles having such a particle size therein, the polymer hollow particles can be dispersed in the polyurethane foam so as to exist as closed cells, and thus the obtained urethane foam Strength can be improved.

In one method for producing the polyurethane foam of the present invention, a mixture comprising a polyol, an organic polyisocyanate, a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles is formed, and the mixture is foamed. A polyurethane foam containing polymer hollow particles can be produced. Specifically, a polyol system containing a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles dispersed therein, and an organic polyisocyanate system are respectively prepared and mixed to form a polyurethane containing polymer hollow particles. Since the foam can be produced, the polymer hollow particles can be easily added into the system for producing the polyurethane foam. Furthermore, many polyol systems are viscous, and by thoroughly stirring and mixing the polyol system containing the polymer hollow particles,
The hollow polymer particles can also be substantially uniformly dispersed in the polyol system. Therefore, polymer hollow particles can be included in the obtained polyurethane foam, preferably in a state of being substantially uniformly dispersed.

The polyurethane foam of the present invention has a low density and is excellent in heat insulating properties, strength and dimensional stability, and is therefore very suitable for use as a heat insulating material. Further, by allowing the polyurethane foam or the heat insulating material of the present invention to be included in the outer box, the inner box, and the gap of the box having the gap between the outer box and the inner box, This box can be used as a high-performance heat-insulating box. Therefore, by applying the polyurethane foam or the heat insulating material of the present invention to a heat insulating box such as a refrigerator or a refrigerated showcase, it is possible to obtain a heat insulating box having a light weight and excellent heat insulation performance, and also to prevent heat leakage from the container. Energy saving can be further promoted, for example, power consumption of refrigerators and refrigerated showcases can be reduced to a minimum, and the quality of the heat insulating box can be improved.

The polyurethane foam of the present invention can be processed into various shapes at the time of polymerization or after the foam is formed, so that it has the required shape, low density, heat insulation, strength and dimensional stability. It can be used as a heat insulating material with excellent properties. Therefore, besides filling the gap between the outer box and the inner box such as a heat insulating box, for example, when foaming the polyurethane foam of the present invention, such as injection method, casting method or spraying method By adopting an application method, it can be applied as a heat insulating material surrounding a member having a complicated shape or a heat insulating material filling a space between two members. The heat insulating material and the heat insulating box of the present invention can be used for various applications as described in the section of the prior art.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 7/22 C08K 7/22 C08L 75/04 C08L 75/04

Claims (14)

[Claims] 1. A polyol, an organic polyisocyanate,
A polyurethane foam formed by foaming a mixture comprising a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles. 2. The polyurethane foam according to claim 1, wherein the blowing agent is at least one compound selected from the group consisting of a hydrocarbon, water and a carboxylic acid compound. 3. The polyurethane foam according to claim 2, wherein the hydrocarbon is cyclopentane. 4. The polyurethane foam according to claim 1, comprising a thermoplastic resin constituting the polymer hollow particles. 5. The thermoplastic resin is a homopolymer of a compound selected from the group consisting of ethylene, propylene, styrene, vinyl chloride, vinylidene chloride, vinyl acetate, acrylate and acrylonitrile, or at least 2
5. The polyurethane foam according to claim 4, which is a copolymer of various compounds. 6. The polyurethane foam according to claim 4, wherein the softening temperature of the thermoplastic resin is 150 ° C. or lower. 7. The polyurethane foam according to claim 1, wherein the hollow polymer particles contain a hydrocarbon having a boiling point of 10 ° C. or less. 8. A polyurethane foam containing polymer hollow particles in a dispersed state. 9. The polyurethane foam according to claim 1, wherein the content of the polymer hollow particles is 1 to 30% by weight, preferably 3 to 20% by weight, based on the weight of the entire polyurethane foam. 10. The polymer hollow particles having a particle size of 1 to 1
The polyurethane foam according to any one of claims 1 to 9, which has a range of 00 µm. 11. A process for producing a polyurethane foam, comprising forming a mixture comprising a polyol, an organic polyisocyanate, a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles, and foaming the mixture. 12. The method for producing a polyurethane foam according to claim 11, wherein a polyol system containing a foam stabilizer, a catalyst, a foaming agent and polymer hollow particles dispersed therein and an organic polyisocyanate system are mixed. 13. A heat insulating material comprising the polyurethane foam according to claim 1. 14. A box body having an outer box, an inner box, and a gap between the outer box and the inner box, wherein the gap is in the gap.
A heat-insulating box comprising the polyurethane foam or the heat-insulating material according to any one of claims 10 to 13.