A polyurethane foam composition and the production method for the same

Abstract

The present invention relates to a rigid polyurethane foam composition comprising a polyol mixture, a polyisocyanate component, a blowing agent, and a deep eutectic solvent (DES) synthesized from a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) as a nucleating agent.

Description

[0001] 7.3644

[0002] DESCRIPTION A POLYURETHANE FOAM COMPOSITION AND THE PRODUCTION METHOD FOR THE SAME

[0003] The present invention relates to a method for preparing a rigid polyurethane foam using deep eutectic solvents as nucleating agents to improve thermal insulation properties, and to a rigid polyurethane foam composition.

[0004] Rigid polyurethane foam (RPUF) is a versatile and efficient insulation material commonly used in refrigerators and other applications requiring thermal insulation. RPUF is known for its excellent thermal insulation properties, structural durability, and lightweight characteristics, which are essential for maintaining internal temperatures and improving energy efficiency in various products. The foam is formed through the reaction between two main components, namely polyols and isocyanates, and a cellular structure is created with the addition of blowing agents.

[0005] In recent years, regulatory restrictions on per- and polyfluoroalkyl substances (PFAS) and F-gases have led to the prohibition of hydrofluoroolefins (HFOs) as blowing agents in the production of RPUF. This regulatory change has necessitated the use of alternative blowing agents, with cyclopentanes becoming the preferred choice. However, cyclopentanes do not reach the thermal conductivity reduction capabilities of hydrofluoroolefins (HFOs), which results in the foam having less effective insulation properties.

[0006] The performance of rigid polyurethane foam (RPUF) is highly influenced by additives and processing parameters. Catalysts control the reaction rate. Surfactants directly affect the mechanical and thermal properties of the foam by controlling the cell structure. Nucleating agents play a critical role in promoting cell formation in rigid polyurethane foams, forming a smaller and more homogeneous cell structure which can reduce thermal conductivity and improve insulation. However, finding cost-effective and environmentally friendly nucleating agents remains a significant challenge in the industry.

[0007] The potential ban on hydrofluoroolefins (HFOs) has created a demand for alternatives which can achieve optimal thermal performance in rigid polyurethane foam (RPUF). This situation has led to increased energy consumption in refrigerators and other applications which rely on rigid polyurethane foam insulation. Moreover, the limitations of existing alternatives have made it7.3644

[0008] difficult for manufacturers to meet increasingly stringent energy efficiency standards while maintaining product performance and cost-efficiency.

[0009] It has thus been understood that there is a need for a new nucleating agent for rigid polyurethane foam which addresses one or more of these issues.

[0010] The aim of the present invention is the realization of a polyurethane foam composition which improves the micro structure of the foam to achieve smaller and more uniform cell sizes, thereby enhancing the thermal and mechanical properties of the material.

[0011] Another aim of the present invention is the realization of a rigid polyurethane foam composition which offers a bio-based, environmentally friendly, and cost-effective solution, thereby reducing the carbon footprint compared to non-bio-based alternatives.

[0012] Yet another aim of the present invention is the realization of a polyurethane foam composition which significantly reduces thermal conductivity, thereby improving the insulation properties of the foam.

[0013] Yet another aim of the present invention is the realization of a polyurethane foam composition which enables a smoother and more efficient production process by preventing clumping and clogging in the mixing device during production, thanks to the liquid form thereof.

[0014] Yet another aim of the present invention is the realization of a polyurethane foam composition which, through integration into foam production, offers significant environmental benefits, improved foam properties, and enhanced process efficiency.

[0015] The rigid polyurethane foam composition of the present invention comprises a polyol mixture, polyisocyanate, blowing agent, and nucleating agent.

[0016] In an embodiment of the present invention, the rigid polyurethane foam composition comprises a deep eutectic solvent as a nucleating agent, wherein the deep eutectic solvent (DES) is obtained with a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA). The use of deep eutectic solvents in the rigid polyurethane foam composition provides synergistic effects which interact with one another, such as enhanced thermal insulation properties, increased environmental sustainability, and more efficient production processes.

[0017] In an embodiment of the present invention, the rigid polyurethane foam composition comprises a polyol mixture which includes polyols such as poly ether polyols and polyester polyols. The mixture of polyether and polyester provides optimum reaction efficiency, and the mechanical properties of the rigid polyurethane foam composition are improved by the addition of polyester.7.3644

[0018] In an embodiment of the present invention, the polyol in the polyol mixture is selected from a group comprising at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, 1,6-hexanediol, cyclohexane dimethanol, neopentyl glycol, polycaprolactone, bisphenol A polyol, polyether polyol, toluenediamine polyol, glycerin polyol, trimethylolpropane polyol, and sucrose glycerin polyol.

[0019] In an embodiment of the present invention, the polyol mixture comprises a polyol, at least one surfactant, a catalyst, and water. The presence of the said additives in the polyol mixture enables the reaction kinetics and safety properties of the rigid polyurethane foam composition to be adjusted, while preserving the effects of the deep eutectic solvent (DES) nucleating agent in the rigid polyurethane foam composition.

[0020] In an embodiment of the present invention, the rigid polyurethane foam composition comprises the deep eutectic solvent (DES) in the range of 1% to 25% by weight of the polyol component. This weight range of the deep eutectic solvent (DES) in the rigid polyurethane foam composition allows optimal nucleation effects, resulting in a dimensionally smaller and more homogeneous cell structure and improved thermal conductivity, without compromising other physical properties.

[0021] In an embodiment of the present invention, the rigid polyurethane foam composition comprises the deep eutectic solvent (DES) wherein the hydrogen bond donor (HBD) is urea and the hydrogen bond acceptor (HBA) is choline chloride, and which is obtained by synthesizing choline chloride and urea in a 1:2 molar ratio.

[0022] In an embodiment of the present invention, the hydrogen bond donor (HBD) is selected from the group consisting of acetamide, oxalic acid, malonic acid, malic acid, xylitol, urea, 1,1-dimethylurea, d-isosorbide, thiourea, trifluoroacetamide, benzamide, itaconic acid, citric acid, imidazole, 2-imidazolinone, 4-hydroxybenzoic acid, cinnamic acid, ethylene glycol, propylene urea, resorcinol, phenylacetic acid, d-sorbitol, lactic acid, 1,3 -dimethylurea, levulinic acid, 1-methylurea, glycerol, succinic acid, hexanoic acid, coumaric acid, stearic acid, adipic acid, oleic acid, suberic acid, linoleic acid, and decanoic acid. The selected hydrogen bond donor enables the deep eutectic solvent (DES) properties to be tailored to specific foam formulations, thereby enabling optimization of nucleation effects for various applications and environmental conditions.7.3644

[0023] In an embodiment of the present invention, the hydrogen bond acceptor (HBA) is selected from the group consisting of ethylammonium chloride, nicotinic acid, trimethylammonium chloride, betaine, choline chloride, choline nitrate, tetramethylammonium chloride, tetramethylammonium bromide, choline tetrafluoroborate, choline fluoride, acetylcholine chloride, choline fluoroacetate, glycine, alanine, proline, methyltriphenylphosphonium bromide, phenyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, methyltriphenylphosphonium chloride, tetrapropylammonium bromide, zinc chloride, and ZnCh. The selected hydrogen bond acceptors provide flexibility in designing deep eutectic solvent (DES) compositions compatible with various polyurethane foam systems and ensure optimal nucleation performance in different formulations.

[0024] In an embodiment of the present invention, the rigid polyurethane foam composition comprises cyclopentane as the blowing agent. The use of cyclopentane as the blowing agent in combination with the deep eutectic solvent (DES) nucleating agent improves the insulation properties of the foam while ensuring compliance with environmental regulations.

[0025] In an embodiment of the present invention, the rigid polyurethane foam composition further comprises one or more than one additive selected from the group comprising at least one catalyst, at least one surfactant, and at least one flame retardant. The inclusion of the said additives in the rigid polyurethane foam composition enables the reaction kinetics and safety properties of the rigid polyurethane foam composition to be adjusted, while preserving the effects of the deep eutectic solvent (DES) nucleating agent.

[0026] An embodiment of the present invention discloses a method for preparing a rigid polyurethane foam.

[0027] A method for preparing a rigid polyurethane foam comprises the steps of:

[0028] - obtaining a deep eutectic solvent (DES) with a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA);

[0029] - adding the deep eutectic solvent (DES) as a nucleating agent to a polyol mixture;

[0030] - combining the polyol mixture with a blowing agent to form a first mixture; and

[0031] - reacting the said first mixture with a polyisocyanate component to obtain a rigid polyurethane foam. Thus, the method for preparing a rigid polyurethane foam comprising the deep eutectic solvent (DES) as a nucleating agent enables the production of a foam with improved thermal7.3644

[0032] insulation properties and a more uniform cell structure, while maintaining a simple and efficient manufacturing process.

[0033] In an embodiment of the present invention, the polyol in the polyol mixture is selected from a group comprising at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, 1,6-hexanediol, cyclohexane dimethanol, neopentyl glycol, polycaprolactone, bisphenol A polyol, polyether polyol, toluenediamine polyol, glycerin polyol, trimethylolpropane polyol, and sucrose glycerin polyol.

[0034] In an embodiment of the present invention, the polyol mixture comprises a polyol, at least one surfactant, a catalyst, and water.

[0035] In an embodiment of the present invention, the method for preparing a rigid polyurethane foam comprises the step of synthesizing a deep eutectic solvent (DES) by combining a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) in a specific molar ratio and mixing the combination at a certain temperature for a predetermined duration.

[0036] In an embodiment of the present invention, the method for preparing a rigid polyurethane foam comprises the step of combining a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) in a 2: 1 molar ratio.

[0037] In an embodiment of the present invention, the method for preparing a rigid polyurethane foam comprises the step of synthesizing the deep eutectic solvent (DES) by mixing the hydrogen bond donor (HBD) and the hydrogen bond acceptor (HBA) at a temperature in the range of approximately 70 to 85°C for a duration in the range of 1 to 2 hours. Thus, these specific conditions for the synthesis of the deep eutectic solvent (DES) provide an efficient and repeatable method for preparing the nucleating agent, ensuring consistent foam quality across production batches.

[0038] In an embodiment of the present invention, the hydrogen bond donor (HBD) is urea and the hydrogen bond acceptor (HBA) is choline chloride. The use of this specific deep eutectic solvent (DES) composition as a nucleating agent in the rigid polyurethane foam composition has demonstrated a particularly synergistic effect, providing an optimal balance between nucleation effects, environmental sustainability, and cost efficiency.

[0039] An embodiment of the present invention is a cooling device comprising a rigid polyurethane foam composition having the features described above. The cooling device comprises an7.3644

[0040] insulation layer containing the rigid polyurethane foam composition, wherein the rigid polyurethane foam composition comprises a polyol component, a polyisocyanate component, a blowing agent, and a deep eutectic solvent (DES) as a nucleating agent. In an embodiment of the present invention, the deep eutectic solvent (DES) is obtained with a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA). The use of a rigid polyurethane foam composition containing the deep eutectic solvent (DES) nucleating agent in the insulation of the cooling device provides enhanced thermal efficiency while complying with environmental regulations, and potentially reduces energy consumption and operating costs.

[0041] In an embodiment of the present invention, the rigid polyurethane foam composition in the insulation layer of the cooling device exhibits a thermal conductivity reduction in the range of 0.5 to 1 mW / mK compared to a reference foam without the deep eutectic solvent (DES) nucleating agent. In this embodiment of the present invention, this significant reduction in thermal conductivity translates into superior insulation performance, potentially enabling thinner insulation layers and improved energy efficiency in cooling device designs.

[0042] In an embodiment of the present invention, the rigid polyurethane foam composition in the insulation layer of the cooling device comprises cyclopentane as the blowing agent, and the rigid polyurethane foam composition is free from hydrofluoroolefins (HFOs). The use of cyclopentane as the blowing agent maintains thermal performance and enables the production of an environmentally friendly cooling device insulation which complies with regulations concerning per- and polyfluoroalkyl substances (PFAS) and F-gases.

[0043] In an embodiment of the present invention, the rigid polyurethane foam composition in the insulation layer of the cooling device comprises the deep eutectic solvent (DES) in the range of 1% to 25% by weight, preferably 1% to 10% by weight, more preferably 1% to 5% by weight of the polyol mixture. The addition of the deep eutectic solvent (DES) as a nucleating agent reduces the thermal conductivity of the resulting foam in the range of approximately 0.5 to 1 mW / mK and improves the insulation properties of the material.

[0044] In an embodiment of the present invention, the rigid polyurethane foam composition in the insulation layer of the cooling device comprises a deep eutectic solvent (DES) synthesized by combining hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs).

[0045] In an embodiment of the present invention, the rigid polyurethane foam composition in the insulation layer of the cooling device comprises a deep eutectic solvent (DES) synthesized by combining choline chloride and urea in a 1:2 molar ratio and mixing the combination at a7.3644

[0046] temperature in the range of 70 to 85°C for a duration in the range of 1 to 2 hours. However, various alternative deep eutectic solvents may be formed by using different combinations of hydrogen bond donors and hydrogen bond acceptors.

[0047] In an embodiment of the present invention, the inclusion of deep eutectic solvents in the rigid polyurethane foam composition can be verified using analytical techniques. Fourier transform infrared spectroscopy (FTIR) analysis of the rigid polyurethane foam composition comprising the deep eutectic solvent (DES) reveals new peaks at 1670 cm1and 954

[0048]

[0049] which are not present in the reference polyurethane foam without the deep eutectic solvent. Moreover, the gas chromatography-mass spectrometry (PY (pyrolyzer) / GC-MS) analysis is used to verify the presence of deep eutectic solvents in the polyurethane foam.

[0050] Table 1: Comparison of the thermal conductivity values of a polyurethane foam composition without a deep eutectic solvent (DES) and a polyurethane foam composition comprising a deep eutectic solvent (DES)

[0051]

Claims

44CLAIMS1. A rigid polyurethane foam composition characterized by comprising a polyol mixture; a polyisocyanate component; a blowing agent; and a deep eutectic solvent (DES) synthesized with a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) as a nucleating agent.

2. A rigid polyurethane foam composition as in Claim 1, characterized by comprising the deep eutectic solvent (DES) in the range of 1% to 25% by weight of the polyol component.

3. A rigid polyurethane foam composition as in Claim 1 or 2, characterized by a polyol mixture comprising at least one surfactant, a catalyst, water, and a polyol.

4. A rigid polyurethane foam composition as in Claim 3, characterized by the polyol which is is selected from a group comprising at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, 1,6- hexanediol, cyclohexane dimethanol, neopentyl glycol, polycaprolactone, bisphenol A polyol, polyether polyol, toluenediamine polyol, glycerin polyol, trimethylolpropane polyol, and sucrose glycerin polyol.

5. A rigid polyurethane foam composition as in any one of the above claims, characterized by the hydrogen bond donor (HBD) which is selected from the group consisting of acetamide, oxalic acid, malonic acid, malic acid, xylitol, urea, 1,1 -dimethylurea, d- isosorbide, thiourea, trifluoroacetamide, benzamide, itaconic acid, citric acid, imidazole, 2-imidazolinone, 4-hydroxybenzoic acid, cinnamic acid, ethylene glycol, propylene urea, resorcinol, phenylacetic acid, d-sorbitol, lactic acid, 1,3 -dimethylurea, levulinic acid, 1- methylurea, glycerol, succinic acid, hexanoic acid, coumaric acid, stearic acid, adipic acid, oleic acid, suberic acid, linoleic acid, and decanoic acid.

6. A rigid polyurethane foam composition as in any one of the above claims, characterized by the hydrogen bond acceptor (HBA) which is is selected from the group consisting of ethylammonium chloride, nicotinic acid, trimethylammonium chloride, betaine, choline chloride, choline nitrate, tetramethylammonium chloride, tetramethylammonium bromide, choline tetrafluoroborate, choline fluoride, acetylcholine chloride, choline fluoroacetate, glycine, alanine, proline, methyltriphenylphosphonium bromide,44phenyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, methyltriphenylphosphonium chloride, tetrapropylammonium bromide, zinc chloride, and ZnCh.

7. A rigid polyurethane foam composition as in any one of the above claims, characterized by comprising cyclopentane as a blowing agent.

8. A rigid polyurethane foam composition as in any one of the above claims, characterized in that the hydrogen bond donor (HBD) is urea, the hydrogen bond acceptor (HBA) is choline chloride and the molar ratio of choline chloride to urea is 1:2.

9. - A method for preparing a rigid polyurethane foam as in any one of Claims 1 to 8, characterized by the steps of- obtaining a deep eutectic solvent (DES) with a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA);- adding the deep eutectic solvent (DES) as a nucleating agent to a polyol mixture;- combining the polyol mixture with a blowing agent to form a first mixture; and- reacting the said first mixture with a polyisocyanate component to obtain a rigid polyurethane foam.

10. A method for preparing a rigid polyurethane foam as in Claim 9, characterized by synthesizing the deep eutectic solvent (DES) by mixing the hydrogen bond donor (HBD) and the hydrogen bond acceptor (HBA) at a temperature in the range of approximately 70°C to 85°C for a duration in the range of 1 to 2 hours.

11. A cooling device characterized by comprising a rigid polyurethane foam composition as in any one of Claims 1 to 8.

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