Rigid polyurethane foam composition having excellent thermal insulation

Abstract

The present invention relates to a rigid polyurethane foam composition and, more specifically, to a rigid polyurethane foam composition in which by using glycerol carbonate as a nucleating agent, the sizes of bubbles in the foam are reduced, thereby improving the bubble composition and thermal insulation performance of the foam. In addition, the nucleating agent is a low-priced eco-friendly nucleating agent rather than a fluorine compound commonly used in rigid polyurethane foams, and solves the problems of existing nucleating agents such as a phase separation problem or a harmfulness problem.

Description

Rigid polyurethane foam composition with excellent insulation properties

[0001] The present invention relates to a rigid polyurethane foam composition, and more particularly, to a rigid polyurethane foam composition capable of increasing the compressive strength of a foam and reducing thermal conductivity by forming small and uniform bubbles using glycerol carbonate as a nucleating agent during the production of polyurethane, thereby improving insulation performance.

[0002] Polyurethane plays a vital role in many industries, from furniture and footwear to construction and automotive applications. Flexible polyurethane foam is used in mattresses, automotive, and household upholstery, while rigid polyurethane foam is the most effective and practical insulation material in a wide range of applications, from household refrigerators to refrigerated containers, cold storage warehouses, and other large industrial buildings.

[0003] Conventional rigid polyurethane foam manufacturing compositions consist of polyol, polyisocyanate, CFC or HCFC compound blowing agent, silicone surfactant, and catalyst. However, recently, to address the issue of banning the use of CFC or HCFC compounds that cause environmental problems in refrigerators and other appliances and to save energy, rigid polyurethane foams using low-boiling-point hydrocarbons such as cyclopentane or pentane as blowing agents have been manufactured as replacements for freon-based blowing agents. However, the compatibility between polyol and cyclopentane or pentane blowing agents is low, which reduces the storability of the polyurethane foam premix, and the thermal conductivity is relatively high compared to CFC and HCFC foams.

[0004] In order to solve the problem of high thermal conductivity that occurs when using hydrocarbons such as pentane and cyclopentane, which are environmentally friendly blowing agents in the production of rigid polyurethane foam, a nucleator such as perfluoroalkane, which reduces the bubble size and improves thermal conductivity, can be added. However, these perfluoroalkanes are harmful to the human body and the environment, and have strong bonding strength, making them difficult to use because of their low compatibility with polyols.

[0005] Therefore, there is a need for a polyurethane foam composition that is environmentally friendly, inexpensive, non-toxic, and improves thermal conductivity by reducing bubble size compared to conventional technologies.

[0006]

[0007] [Prior Art Literature]

[0008] [Patent Document]

[0009] (Patent Document 1) Korean Patent No. 2010-0082116

[0010] (Patent Document 2) Korean Patent No. 2003-0017127

[0011] (Patent Document 3) Korean Patent No. 2000-0061868

[0012] In order to solve such problems, the purpose of the present invention is to provide a rigid polyurethane foam composition in which glycerol carbonate is added as a nucleating agent during the manufacture of a polyurethane foam composition to form small and uniform bubbles in the foam, thereby improving the bubble composition and insulating performance of the foam.

[0013] To achieve the above purpose,

[0014] The rigid polyurethane foam composition of the present invention comprises a polyol, a physical blowing agent, and glycerol carbonate as a nucleating agent.

[0015] It is preferable that the amount of glycerol carbonate added is 1 to 10 parts by weight based on 100 parts by weight of polyol.

[0016] The above polyol may be a polyester polyol, a polyether polyol, or a mixture of a polyester polyol and a polyether polyol.

[0017] The foam composition may further include a foaming agent, a catalyst, a flame retardant, and water.

[0018] The above-mentioned stabilizer may be at least one selected from the group consisting of silicone, silicone glycol copolymer, polysiloxane ether, and vinyl-2-pyrrolidone.

[0019] The catalyst may be at least one selected from the group consisting of dimethylcyclohexylamine, triethylenediamine, dimethylethanolamine, tetramethyl butanediamine, triethylamine, pentamethyldiethylenetriamine, tris[3-(dimethylamino)propyl] hexahydrotriazine, potassium octoate, dibutyltin dilaurate, dibutyltin dimercaptide, and stannous octoate.

[0020] The above flame retardant may be at least one selected from the group consisting of Tris(1-Chloro-2-Propyl)Phosphate, Tris(2-Chloropropyl)Phosphate, Tris(2-Chloroethyl)Phosphate, and chlorinated paraffins.

[0021] The above physical blowing agent is cyclopentane, hydrochlorofluorocarbon (HCFC-141b), 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), methyl formate, chloropropene, 1-chloropropene, 2-chloropropene, 3-chloropropene, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, It may be at least one selected from the group consisting of cis-1,1,1,4,4,4-hexafluoro-2-butene, pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1-dichloro-1-fluoroethane, trans-1,2-dichloroethylene, methylal, c-pentane, n-pentane, and i-pentane.

[0022] The rigid polyurethane foam composition of the present invention can cause a rapid crosslinking reaction by using glycerol carbonate as a nucleating agent, thereby making the cell wall rigid and preventing single bubbles generated during foaming from fusing and growing, and forming the bubbles small and uniformly during foaming, thereby increasing the compressive strength of the foam and reducing the thermal conductivity, thereby improving the insulation performance.

[0023] In addition, by using glycerol carbonate, not a fluorine compound, as a nucleating agent, it is less hazardous, more environmentally friendly, reduces phase separation problems, and reduces production costs, resulting in economic benefits.

[0024]

[0025] Figure 1 is a graph comparing the average size of independent cells of a foam using cyclopentane according to the amount of nucleating agent added according to one embodiment of the present invention.

[0026] Figure 2 is a graph showing the average size of independent cells and the thermal conductivity according to the presence or absence of a core agent in a foam according to one embodiment and a comparative example of the present invention.

[0027] Figure 3 is a graph showing the distribution of compressive strength according to the average size of independent cells of a foam using cyclopentane according to one embodiment of the present invention.

[0028] Figure 4 is a graph showing the thermal conductivity according to the amount of nucleating agent added to a foam using cyclopentane according to one embodiment of the present invention.

[0029] Hereinafter, embodiments will be described in detail with reference to the attached drawings. The embodiments described in this specification and the configurations depicted in the drawings are preferred embodiments of the present invention, but do not fully represent the technical spirit of the present invention. Therefore, various equivalents and modified examples may be substituted for them at the time of filing of this application.

[0030] The terms used in the examples are for the purpose of description only and should not be construed as limiting the scope of the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "has" and the like are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0031] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0032] Components that share common functions with components included in one embodiment will be described using the same designation in other embodiments. Unless otherwise stated, the descriptions given in one embodiment may also apply to other embodiments, and detailed descriptions will be omitted to the extent of overlap.

[0033]

[0034] The present invention provides a rigid polyurethane foam composition having excellent insulating properties, wherein the foam composition comprises a polyol, a physical blowing agent, and glycerol carbonate as a nucleating agent.

[0035] The above polyol can be used alone or in a mixture, and may vary depending on the index of the foam being manufactured. The reasons for using a mixture are to achieve a high price, improve flame retardancy, and match the index (calculating the appropriate polyol and isocyanate content in the polyurethane). In addition, the polyol may be a polyester polyol, a polyether polyol, or a mixture of a polyester polyol and a polyether polyol.

[0036] The above physical blowing agent is cyclopentane, hydrochlorofluorocarbon (HCFC-141b), 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), methyl formate, chloropropene, 1-chloropropene, 2-chloropropene, 3-chloropropene, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, It may be at least one selected from the group consisting of cis-1,1,1,4,4,4-hexafluoro-2-butene, pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1-dichloro-1-fluoroethane, trans-1,2-dichloroethylene, methylal, c-pentane, n-pentane, and i-pentane.

[0037] In the examples and comparative examples of the present invention, cyclopentane, 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), and hydrochlorofluorocarbon (HCFC-141b) were used as physical blowing agents, each of which has a different molecular weight and boiling point. The blowing agents are vaporized by the heat of reaction generated by the reaction between polyol and isocyanate, thereby forming bubbles, and the size of the bubbles thus formed varies depending on the type of blowing agent used.

[0038] The performance of physical blowing agents such as 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) and hydrochlorofluorocarbon (HCFC-141b) is higher than that of cyclopentane, but they have the disadvantages of being expensive and causing environmental pollution. On the other hand, cyclopentane has low performance as an insulator due to its large bubble size when used alone, but the addition of glycerol carbonate as a nucleating agent reduces the bubble size, thereby improving the insulation effect and being environmentally friendly.

[0039] The above glycerol carbonate is also called glycerine carbonate or 4-Hydroxymethyl-1,3-dioxolan-2-one and has a structure represented by the following chemical formula 1.

[0040] [Chemical Formula 1]

[0041]

[0042] The above-mentioned glycerol carbonate not only aids in some foaming action but also acts as a cross-linking agent. This fast cross-linking reaction strengthens the cell walls, preventing single bubbles from coalescing and growing during foaming, and creates small, uniform bubbles. This improves the foam's cell composition and insulation performance.

[0043] The above glycerol carbonate is a nucleating agent, and is preferably used in an amount of 1 to 10 parts by weight based on 100 parts by weight of polyol. If it is used in an amount less than 1 part by weight, the effect of the nucleating agent is minimal, and if it is used in an amount exceeding 10 parts by weight, the nucleating agent promotes foaming of the physical blowing agent, thereby increasing the number of open cells, which tends to reduce the performance of the rigid polyurethane foam. As the number of open cells increases, the ability to withstand the load weakens, reducing the compressive strength and increasing the thermal conductivity, which may reduce the overall performance despite the small number of cells.

[0044] However, the optimal content of glycerol carbonate, a nucleating agent, may vary depending on the type and amount of polyol, stabilizer, flame retardant, catalyst, etc. added.

[0045] Using an excessive amount of nucleating agent will cause the heat generated from the foaming reaction to accelerate foaming before the foam has fully cured, converting the closed cells created within the foam into open cells, thereby increasing the number of open cells. The smaller the cell size, the lower the thermal conductivity, and the lower the thermal conductivity, the better the insulation effect. Furthermore, smaller cell sizes help distribute the load applied to the foam, which has the effect of improving mechanical properties.

[0046] In the present invention, instead of the fluorine compounds commonly used in rigid polyurethane foam, low-cost, environmentally friendly glycerol carbonate is used as a nucleating agent, thereby solving problems of existing nucleating agents, such as phase separation problems and toxicity problems.

[0047] Additionally, the rigid polyurethane foam composition may further include a foaming agent, a catalyst, a flame retardant, and water.

[0048] The above-mentioned stabilizer may be at least one selected from the group consisting of silicone, silicone glycol copolymer, polysiloxane ether, and vinyl-2-pyrrolidone.

[0049] The catalyst may be at least one selected from the group consisting of dimethylcyclohexylamine, triethylenediamine, dimethylethanolamine, tetramethyl butanediamine, triethylamine, pentamethyldiethylenetriamine, tris[3-(dimethylamino)propyl] hexahydrotriazine, potassium octoate, dibutyltin dilaurate, dibutyltin dimercaptide, and stannous octoate.

[0050] The above flame retardant may be at least one selected from the group consisting of Tris(1-Chloro-2-Propyl)Phosphate, Tris(2-Chloropropyl)Phosphate, Tris(2-Chloroethyl)Phosphate, and chlorinated paraffins.

[0051] The amounts of the above-mentioned stabilizer, catalyst, flame retardant, and water can be selected in various ways depending on the application target of the foam and the required physical properties.

[0052]

[0053] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples, in accordance with the gist of the present invention.

[0054] In addition, in the manufacturing method of the present invention, other polyols, stabilizers, catalysts, flame retardants, foaming agents, etc. other than the nucleating agent can be arbitrarily selected and used as those commonly used.

[0055]

[0056] <Example>

[0057] Examples 1 to 8, Comparative Examples 1 to 3: Preparation of rigid polyurethane foam

[0058] In order to manufacture a rigid polyurethane foam, a system (System Mixing Ratio) was created using polyester polyol, polyether polyol, a foaming agent, a flame retardant, a catalyst, and water as described in Table 1 below, and mixed with isocyanate to manufacture polyurethane foam compositions of Examples 1 to 8 and Comparative Examples 1 to 3.

[0059] Specifically, as described in Table 1 below, a system (System Mixing Ratio) was prepared using 10 parts by weight of polyester polyol (Polyester polyol, OHV=320, SP-320G, Seho Co., Ltd.), 10 parts by weight of polyester polyol (Polyester polyol, OHV=240, SP-240, Seho Co., Ltd.), 80 parts by weight of polyether polyol (Polyether polyol, OHV=440, HS-209, KPX chemical product), 2.5 parts by weight of silicone surfactant (Silicone surfactant, AK-8805, Maysta product), 15 parts by weight of flame retardant (Tris(1-Chloro-2-Propyl)Phosphate, TCPP), 0.6 parts by weight of catalyst (Dimethylcyclohexylamine, PC-8), and 2.8 parts by weight of water. Polyurethane foam compositions of Examples 1 to 8 and Comparative Examples 1 to 3 were prepared using 100 parts by weight of the above system (System Mixing Ratio) and 110 parts by weight of MDI (Methylene Diphenyl diisocyanate).

[0060] Examples 1 to 8 were prepared by adding glycerol carbonate, a nucleating agent, to the above composition as described in Table 1.

[0061] For the physical blowing agent, cyclopentane, 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), and hydrochlorofluorocarbon (HCFC-141b) were used as described in Table 1 to prepare Examples 1 to 8 and Comparative Examples 1 to 3.

[0062]

[0063] <Example of an exam>

[0064] Test Example 1: Measurement of the average size of independent cells in a foam using cyclopentane according to the amount of nucleating agent added.

[0065] In order to measure the average size of independent cells in a foam using cyclopentane according to the amount of nucleating agent added, the cell size of the independent cells was measured by preparing three specimens with an area of ​​1×1 cm per sample using a scanning electron microscope (SEM), obtaining more than 10 images per specimen, and measuring the size of the independent cells one by one and averaging them.

[0066] Referring to Table 1 and Figure 1, the cell size of Comparative Example 1, a rigid polyurethane foam manufactured using only cyclopentane as a physical blowing agent, was 554.6 ㎛, but the cell sizes of Examples 1 to 6, which are rigid polyurethane foams manufactured by adding glycerol carbonate as a nucleating agent, were 529.8 ㎛, 544.2 ㎛, 506.5 ㎛, 464.2 ㎛, 410.5 ㎛, and 429.9 ㎛, respectively, indicating that adding glycerol carbonate as a nucleating agent has the effect of reducing the cell size by about 10% to 30%.

[0067]

[0068] Test Example 2: Measurement of the average size of independent cells and the resulting thermal conductivity according to the presence or absence of a nucleating agent in the foam.

[0069] The average size of independent cells was measured according to the presence or absence of a nucleating agent in foams using other foaming agents, and the thermal conductivity was measured accordingly.

[0070] Referring to Table 1 and FIG. 2, Example 7 and Comparative Example 2 were manufactured using 1-chloro-3,3,3-trifluoropropene (HFO-1233zd) as a physical blowing agent, and Example 8 and Comparative Example 3 were manufactured using hydrochlorofluorocarbon (HCFC-141b) as a physical blowing agent. The cell sizes of Examples 7 and 8, which are rigid polyurethane foams manufactured by adding a nucleating agent, were 374.6 ㎛ and 400.7 ㎛, respectively, and the cell sizes of Comparative Examples 2 and 3, which are rigid polyurethane foams manufactured without adding a nucleating agent, were 412.0 ㎛ and 502.1 ㎛, respectively, showing that the addition of a nucleating agent has the effect of reducing the cell size by about 10% to 20%.

[0071]

[0072] Test Example 3: Measurement of Compressive Strength According to the Average Size of Independent Cells in a Cyclopentane-Based Foam

[0073] To measure the compressive strength according to the average size of independent cells of a foam using cyclopentane, the KS M 3809 method was performed.

[0074] Referring to Table 1 and Figure 3, the cell sizes of rigid polyurethane foam examples 1 to 5 manufactured using cyclopentane as a physical blowing agent were 529.8 ㎛, 544.2 ㎛, 506.5 ㎛, 464.2 ㎛, and 410.5 ㎛, respectively, and the compressive strengths were 0.061 ㎫, 0.065 ㎫, 0.070 ㎫, 0.072 ㎫, and 0.068 ㎫, respectively.

[0075] The rigid polyurethane foams of Examples 1 to 4 containing 1 to 5 parts by weight of the glycerol carbonate nucleating agent showed increased compressive strength due to improved load distribution as the cell size decreased, and in the case of Examples 5 to 6 using more than 5 parts by weight of the glycerol carbonate nucleating agent, the cell size decreased, but the compressive strength decreased.

[0076]

[0077] Test Example 4: Thermal Conductivity According to the Addition Amount of Nucleating Agent in a Foam Using Cyclopentane

[0078] To measure the thermal conductivity according to the amount of nucleating agent added to the foam using cyclopentane, the KS L 9016 method was performed.

[0079] Referring to Table 1 and Fig. 4, the cell sizes of rigid polyurethane foam examples 1 to 5 and comparative example 1 manufactured using cyclopentane as a physical blowing agent were 529.8 ㎛, 544.2 ㎛, 506.5 ㎛, 464.2 ㎛, 410.5 ㎛, and 554.6 ㎛, respectively, and the thermal conductivities were 0.02570 W / m·K, 0.02425 W / m·K, 0.02375 W / m·K, 0.02554 W / m·K, 0.02621 W / m·K, and 0.02591 W / m·K, respectively.

[0080] In Examples 1 to 4, which are rigid polyurethane foams manufactured by including 1 to 5 parts by weight of a glycerol carbonate nucleating agent, the thermal conductivity decreased as the cell size decreased, and in Examples 5 to 6, which are rigid polyurethane foams manufactured by using more than 5 parts by weight of a glycerol carbonate nucleating agent, the number of open cells increased in terms of thermal conductivity, and the presence of carbon dioxide released due to the foaming reaction of the nucleating agent increased the thermal conductivity of the gas in the cells, thereby reducing the insulating effect. In Comparative Example 1, which is a rigid polyurethane foam manufactured without adding a glycerol carbonate nucleating agent, both the cell size and the thermal conductivity were high.

[0081] The optimal content of glycerol carbonate, a nucleating agent, varies depending on the type and amount of polyol and physical blowing agent added. When cyclopentane was used as the physical blowing agent, the content of glycerol carbonate, a nucleating agent, was 1 to 5 parts by weight, resulting in small bubble size, low thermal conductivity, and high compressive strength.

[0082]

[0083] Example / Comparative Example Example Example Example Example Example Example Example Example Example Example Preliminary Comparison Preliminary Comparison Preliminary Comparison Example 12345678123 Polyester polyol 1 (OHV=320): 10Polyester polyol 2 (OHV=240): 10Polyether polyol 3 (OHV=440): 80Silicone surfactant 4 : 2.5 Fire retardant 5 : 15CAT 6: 0.6H2O: 2.8MDI / System Mixing Ratio - 110 / 100 foaming agent amount 2828282828283131283131 used Foaming AgentCyclopentaneCyclopentaneCyclopentaneCyclopentaneCyclopentaneCyclopentaneHFO-1233zdHCFC-141bCyclopentaneHFO-1233zdHCFC-141bNuclear Jeyang123571033000FRD (kg / m 3 )18.118.418.318.618.517.918.81918.219.119.4Compressive strength (MPa)0.0610.0650.0700.0720.0680.0440.0610.0800.0590.0690.072Thermal conductivity (W / m K)0.025700.0242 50.023750.025540.026210.026830.020910.020960.025910.022140.02141Average independent bubble size (㎛)529.8544.2506.5464.2410.5429.9374.6400.7554.6412.0502.11. SP-320G, Seho Co., Ltd. product 2. SP-240, Seho Co., Ltd. product 3. HS-209, KPX chemical product 4. AK-8805, Maysta product 5. Tris(1-Chloro-2-Propyl)Phosphate, TCPP 6. Dimethylcyclohexylamine, PC-8

Claims

1. A rigid polyurethane foam composition comprising a polyol, a physical blowing agent, and glycerol carbonate as a nucleating agent.

2. In paragraph 1, A rigid polyurethane foam composition characterized in that the amount of glycerol carbonate added is 1 to 10 parts by weight based on 100 parts by weight of polyol.

3. In paragraph 1, A rigid polyurethane foam composition characterized in that the polyol is a polyester polyol, a polyether polyol, or a mixture of a polyester polyol and a polyether polyol.

4. In paragraph 1, A rigid polyurethane foam composition characterized in that the foam composition further comprises a foaming agent, a catalyst, a flame retardant, and water.

5. In paragraph 4, A rigid polyurethane foam composition characterized in that the foaming agent is at least one selected from the group consisting of silicone, silicone glycol copolymer, polysiloxane ether, and vinyl-2-pyrrolidone.

6. In paragraph 4, A rigid polyurethane foam composition characterized in that the catalyst is at least one selected from the group consisting of dimethylcyclohexylamine, triethylenediamine, dimethylethanolamine, tetramethyl butanediamine, triethylamine, pentamethyldiethylenetriamine, tris[3-(dimethylamino)propyl] hexahydrotriazine, potassium octoate, dibutyltin dilaurate, dibutyltin dimercaptide, and stannous octoate.

7. In paragraph 4, A rigid polyurethane foam composition characterized in that the flame retardant is at least one selected from the group consisting of Tris(1-Chloro-2-Propyl)Phosphate, Tris(2-Chloropropyl)Phosphate, Tris(2-Chloroethyl)Phosphate, and chlorinated paraffins.

8. In paragraph 1, The above physical blowing agent is cyclopentane, hydrochlorofluorocarbon (HCFC-141b), 1-chloro-3,3,3-trifluoropropene (HFO-1233zd), methyl formate, chloropropene, 1-chloropropene, 2-chloropropene, 3-chloropropene, 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene, A rigid polyurethane foam composition characterized by comprising at least one selected from the group consisting of cis-1,1,1,4,4,4-hexafluoro-2-butene, pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1-dichloro-1-fluoroethane, trans-1,2-dichloroethylene, methylal, c-pentane, n-pentane, and i-pentane.

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