Polyurethane foam and cushioning material

Abstract

To provide a polyurethane foam having excellent antistatic ability while ensuring physical properties of the polyurethane foam.SOLUTION: A polyurethane foam is made from a composition comprising a polyol, an isocyanate, and an ionic compound, the polyurethane foam having density of 10 kg / m3 or more and 80 kg / m3 or less. The ionic compound includes an anion, which is a fluorine-containing anion.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to polyurethane foams and cushioning materials.

Background Art

[0002] Patent Document 1 describes a polyurethane containing an ionic liquid which is a kind of ionic compound. It is described that various compounds can be used as the ionic liquid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the conventional technology is used for polyurethane foams, depending on the type of ionic compound, the antistatic ability is insufficient. Also, depending on the type of ionic compound, there is a problem that the physical properties of the polyurethane foam cannot be ensured.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to obtain a polyurethane foam having good antistatic ability while ensuring the physical properties of the polyurethane foam. The present disclosure can be realized in the following forms.

Means for Solving the Problems

[0006] A polyurethane foam obtained from a composition containing a polyol, an isocyanate, and an ionic compound, where the density of the polyurethane foam is 10 kg / m 3 or more and 80 kg / m 3 or less, The anion of the aforementioned ionic compound is a fluorine-containing anion, in a polyurethane foam. [Effects of the Invention]

[0007] According to this disclosure, it is possible to obtain a polyurethane foam that has good antistatic properties while ensuring the physical properties of the polyurethane foam. [Modes for carrying out the invention]

[0008] Herein lies a preferred example of this disclosure. • A polyurethane foam obtained from a composition comprising a polyol, an isocyanate, and an ionic compound, The hardness of the aforementioned polyurethane foam, measured according to JIS K 6400-2:2012 6.7D method, is between 20N and 400N. The anion of the aforementioned ionic compound is a fluorine-containing anion, in a polyurethane foam. A polyurethane foam in which the content of the ionic compound is greater than 0 parts by mass and less than 5.0 parts by mass per 100 parts by mass of polyol. • A polyurethane foam in which the anion of the ionic compound is selected from the group of anions represented by the following formulas (1)-(4). [ka] In formula (1), R 1 , R 2 Each of these independently represents a saturated or unsaturated linear or branched alkyl group having 1 to 10 carbon atoms, in which a fluorine atom or some or all of a hydrogen atom is substituted with a fluorine atom. [ka] [ka] [ka] In formula (4), R 3 This represents a saturated or unsaturated linear or branched alkyl group having 1 to 10 carbon atoms, in which some or all of the hydrogen atoms are replaced by fluorine atoms. • Volume resistivity is 5.0 × 10⁻⁶ 11 Polyurethane foam with a density of Ω·cm or less. • Cushioning material featuring the polyurethane foam described above.

[0009] The disclosure is described in detail below. In this specification, when a numerical range is indicated using "-", it includes both the lower and upper limits unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less".

[0010] 1. Polyurethane foam (Part 1) Polyurethane foam (part 1) is a polyurethane foam obtained from a composition containing a polyol, an isocyanate, and an ionic compound. The density of the polyurethane foam is 10 kg / m³. 3 More than 80kg / m 3 The following applies: Anions in ionic compounds are fluorine-containing anions.

[0011] In addition to the polyol, isocyanate, and ionic compound, the composition may optionally contain at least one component selected from a foaming agent, catalyst, or foam stabilizer. The components of the composition will be described below.

[0012] (1) Polyol The polyol is not particularly limited. Various polyols may be used individually or in combination of two or more. Examples of polyols include polyether polyols, polyester polyols, and polyether ester polyols.

[0013] Examples of polyether polyols include polyether polyols obtained by adding alkylene oxides such as ethylene oxide (EO) and propylene oxide (PO) to polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose.

[0014] Examples of polyester polyols include those obtained by polycondensation of aliphatic carboxylic acids such as malonic acid, succinic acid, and adipic acid, or aromatic carboxylic acids such as phthalic acid, with aliphatic glycols such as ethylene glycol, diethylene glycol, and propylene glycol. Furthermore, examples of polyether ester polyols include those obtained by reacting the aforementioned polyether polyol with a polybasic acid to produce polyester, or those having both polyether and polyester segments within a single molecule.

[0015] Regarding the polyol, it is preferable to use one or more polyols having a hydroxyl value (OHV) of 25-70 mgKOH / g, 2-4 functional groups, and a weight-average molecular weight of 500-7000.

[0016] (2) Ionic compounds The ionic compounds described herein are compounds composed of a cation and anion. Ionic compounds may be solid or liquid at 100°C. Among ionic compounds, those with a melting point of 100°C or lower are also called ionic liquids. The inventors have diligently studied polyurethane foams using various ionic compounds composed of cations and anions, and have newly discovered a relationship between the type of ionic compound and the antistatic properties of the polyurethane foam, leading to the development of the technology described herein.

[0017] The anion of the ionic compound is a fluorine-containing anion. The fluorine-containing anion may be a fluorine-containing organic anion or a fluorine-containing inorganic anion. When using an ionic compound with a fluorine-containing anion, the reason for the improvement of the antistatic ability of the polyurethane foam is not clear, but it may be related to the hydrophobicity exhibited by the fluorine-containing anion.

[0018] The anion of the ionic compound is preferably selected from the group of anions represented by the following formulas (1)-(4). Among these groups of anions, from the viewpoint of temperature stability, the following formulas (1), (3), and (4) are more preferable, and from the viewpoints of temperature stability and volume resistivity, the following formula (1) is even more preferable.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0019] R 1 , R 2Examples of these include F, CF3, CHF2, and C2F5. Among these, CF3 is particularly preferred. That is, the anion of the ionic compound is particularly preferably the bis(trifluoromethanesulfonyl)amide anion represented by the following formula (1-1). [ka]

[0020] Also, R in equation (4) above 3 Examples include CF3, CHF2, and C2F5. Among these, CF3 is particularly preferred. That is, CF3SO3 is the preferred anion for the ionic compound. - It is particularly preferable that this be the case.

[0021] The cation of the ionic compound is not particularly limited, and any cation commonly used in ionic compounds can be used. Examples of cations of ionic compounds include cations selected from the group consisting of onium cations of 5-6 membered ring compounds with 1-3 nitrogen atoms, quaternary ammonium cations, phosphonium cations, and alkali metal cations. Examples of onium cations of 5-6 membered ring compounds with 1-3 nitrogen atoms include onium cations of 5-membered ring compounds such as imidazolium cations and pyrrolidinium cations, and onium cations of 6-membered ring compounds such as pyridinium cations and piperidinium cations. Among these, imidazolium cations and pyridinium cations are preferred.

[0022] Examples of imidazolium cations include the imidazolium cation represented by the following formula (11). [ka] In formula (11), R 4 , R 5 , R 6 , R 7 , R 8Each of them operates independently. hydrogen atom, Substituted or unsubstituted C1-C20 saturated or unsaturated linear, branched, or cyclic alkyl groups, Substituted or unsubstituted aryl groups with 6-30 carbon atoms, A substituted or unsubstituted arylalkyl group having 7-31 carbon atoms, or It is an alkoxy group having 1 to 20 carbon atoms. If the alkyl group, aryl group, or arylalkyl group is substituted, it is substituted with a halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyloxy group, acyl group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, dialkylamino group, arylamino group, hydroxyl group, carboxyl group, formyl group, mercapto group, sulfo group, mesyl group, p-toluenesulfonyl group, amino group, nitro group, cyano group, trifluoromethyl group, trichloromethyl group, trimethylsilyl group, phosfinico group, or phosphono group.

[0023] R in equation (11) above 4 , R 5 , R 6 , R 7 , R 8 Examples include, R 4 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, 2-hydroxyethyl, or 2-cyanoethyl, R 6 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, 2-hydroxyethyl, or 2-cyanoethyl, R 5 , R 7 , R 8 These can be hydrogen, methyl, or ethyl, each independently of the others.

[0024] Specifically, an example of an imidazolium cation is the 1-butyl-3-methylimidazolium cation represented by the following formula (11-1). [ka]

[0025] Examples of pyridinium cations include the pyridinium cation represented by the following formula (12). [ka] In formula (12), R 9 , R 10 , R 11 , R 12 , R 13 , R 14 Each of them operates independently. hydrogen atom, Substituted or unsubstituted C1-C20 saturated or unsaturated linear, branched, or cyclic alkyl groups, Substituted or unsubstituted aryl groups with 6-30 carbon atoms, A substituted or unsubstituted arylalkyl group having 7-31 carbon atoms, or It is an alkoxy group having 1 to 20 carbon atoms. If the alkyl group, aryl group, or arylalkyl group is substituted, it is substituted with a halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyloxy group, acyl group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, dialkylamino group, arylamino group, hydroxyl group, carboxyl group, formyl group, mercapto group, sulfo group, mesyl group, p-toluenesulfonyl group, amino group, nitro group, cyano group, trifluoromethyl group, trichloromethyl group, trimethylsilyl group, phosfinico group, or phosphono group.

[0026] R in equation (12) above 9 , R 10, R 11 , R 12 , R 13 , R 14 Examples include, R 9 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, 2-hydroxyethyl, or 2-cyanoethyl, R 10 -R 14 One example is a compound that is methyl or ethyl, with the remainder being hydrogen.

[0027] Specifically, an example of a pyridinium cation is the 1-butyl-3-methylpyridinium cation represented by the following formula (12-1). [ka]

[0028] As for alkali metal cations, K + kaNa + , and Li + These are some examples.

[0029] Specific examples of ionic compounds include, for example, potassium bis(trifluoromethanesulfonyl)amide, 1-butyl-3-methylimidazolium=bis(trifluoromethanesulfonyl)amide, 1-butyl-3-methylpyridinium=bis(trifluorosulfonyl)amide, potassium hexafluorophosphate, 1-butyl-3-methylimidazolium hexafluorophosphate, sodium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, lithium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, and 1-butyl-3-methylpyridinium trifluoromethanesulfonate. Ionic compounds may be used individually or in combination of two or more.

[0030] The content of the ionic compound is not particularly limited and can be set according to the required volume resistivity and various physical properties of the polyurethane foam. The content of the ionic compound is more than 0 parts by mass per 100 parts by mass of polyol, preferably 0.2 parts by mass or more, and may be 0.5 parts by mass or more, 1.0 parts by mass or more, or 1.5 parts by mass. From the viewpoint of foaming properties, the content of the above ionic compound is preferably less than 5.0 parts by mass, and may be 4.0 parts by mass or less, 3.0 parts by mass or less, 2.5 parts by mass or less, or 2.0 parts by mass or less. The content of the above ionic compound is preferably more than 0 parts by mass and less than 5.0 parts by mass, and can be set within a range that appropriately combines the above lower and upper limits.

[0031] (3) Foaming agents, catalysts, foam stabilizers, and other components As a blowing agent, water, alternative chlorofluorocarbons (CFCs), or hydrocarbons such as pentane can be used alone or in combination. From the viewpoint of cost and reducing environmental impact, water is preferred as the blowing agent. In the case of water, carbon dioxide is generated during the reaction between the polyol and isocyanate, and foaming occurs due to this carbon dioxide. The amount of water used as a blowing agent is preferably 1.0 part by mass or more and 6.0 parts by mass or less, and more preferably 2.0 parts by mass or more and 5.0 parts by mass or less, per 100 parts by mass of polyol.

[0032] The catalyst promotes the urethane reaction between the polyol and the isocyanate. Examples of catalysts include amine-based catalysts and metal catalysts. Specifically, amine-based catalysts include N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethylaminoethanol, N,N',N'-trimethylaminoethylpiperazine, and triethylenediamine. Examples of metal catalysts include tin catalysts such as stas octoate (stannous octylate) and dibutyltin dilaurate, as well as phenylmercury propionate and lead octate. The amount of catalyst is preferably 0.1 parts by mass to 5.0 parts by mass per 100 parts by mass of polyol.

[0033] As a foam stabilizer, those known for use in polyurethane foams can be used. Examples include silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and known surfactants. The amount of foam stabilizer to be added is preferably 0.4 parts by mass or more and 1.5 parts by mass or less per 100 parts by mass of polyol.

[0034] The composition may optionally contain other components, such as crosslinking agents, plasticizers, flame retardants, fillers, antioxidants, UV absorbers, defoaming agents, compatibilizers, colorants, stabilizers, antibacterial agents, antifungal agents, deodorizers, fragrances, and scents. Examples of crosslinking agents include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, glycerin, trimethylolpropane, and other short-chain diol crosslinking agents. Examples of colorants include pigments, dyes, and colorants.

[0035] (4) Isocyanates As isocyanates, aliphatic or aromatic isocyanates having two or more isocyanate groups, mixtures thereof, and modified isocyanates obtained by modifying them can be used. Examples of aliphatic isocyanates include hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexamethane diisocyanate, while examples of aromatic isocyanates include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate, xylylene diisocyanate, and polymeric isocyanate (crude MDI). In addition, polyisocyanates, which are polymers of other prepolymers or isocyanates, can also be used.

[0036] From the viewpoint of effervescence, toluene diisocyanate (TDI) is more preferably used as the isocyanate. Examples of toluene diisocyanate (TDI) include 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), or a mixture of 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). The mixing ratio (2,4-TDI / 2,6-TDI, mass ratio) of the mixture of 2,4-TDI and 2,6-TDI is preferably 50 / 50-90 / 10, and more preferably 70 / 30-85 / 15.

[0037] The isocyanate index (INDEX) is preferably 70 or higher, and more preferably between 70 and 120. The isocyanate index is calculated by dividing the number of moles of isocyanate groups in the isocyanate by the total number of moles of active hydrogen groups such as hydroxyl groups in the polyol, and multiplying the result by 100. It is calculated as [NCO equivalent of isocyanate / active hydrogen equivalent × 100].

[0038] 2. Method for manufacturing polyurethane foam Polyurethane foam can be produced by known foaming methods, which involve stirring and mixing a composition to react a polyol with an isocyanate. Foaming methods include slab foaming and mold foaming, and either method may be used. Slab foaming involves extruding a mixed polyurethane resin composition onto a belt conveyor and foaming it at atmospheric pressure and room temperature. Mold foaming, on the other hand, involves filling a mold with a mixed polyurethane resin composition and foaming it within the mold.

[0039] Salts of fluorine-containing anions have good ionic dissociation properties and can therefore be readily mixed with other components. Among ionic compounds, ionic liquids that exist as liquids at 100°C are easy to add to compositions and easy to stir and mix. Among ionic compounds, ionic compounds that exist as solids at 100°C, such as alkali metal salts, may be mixed with other components in a solid state or in a dissolved state in a solvent (such as water).

[0040] 3. Physical properties of polyurethane foam The physical properties of the polyurethane foam can be appropriately set according to the application and other factors. A flexible polyurethane foam is preferable. That is, according to this embodiment, by using a specific ionic compound, even flexible polyurethane foams, which have not been conventionally applied, can be suitably obtained.

[0041] (1) Volume resistivity The volume resistivity (JIS K6911) can be set appropriately depending on the application, etc. The volume resistivity is 1.0 × 10⁻⁶. 12 Preferably, it should be Ω·cm or less, and 5.0 × 10 11 It is more preferable that it be Ω·cm or less, and 1.0 × 10 11 It is even more preferable that the resistivity is Ω·cm or less. Also, the volume resistivity is 5.0 × 10⁻⁶ 10 Ω cm or less, 1.0×10 10 It is also possible to set it to Ω·cm or less. The lower limit of volume resistivity is not particularly limited; for example, 1.0 × 10 7 It is greater than Ω·cm. Volume resistivity can be controlled by adjusting the ionic structure of the ionic compound, the proportion of the ionic compound in the mixture, and the density of the polyurethane foam.

[0042] (2) Density (apparent density) The density (JIS K7222:2005) is 10 kg / m³. 3 The above is preferable, preferably 15 kg / m 3 The above is preferable to 20 kg / m 3 That's all. The density is 80 kg / m³. 3 The following applies: 70 kg / m 3 Below 60kg / m 3 Below 50kg / m 3 Below 40kg / m 3 The following is possible: The density is 10 kg / m³. 3 More than 80kg / m 3 The range is as follows, and can be a combination of the above upper and lower limits as appropriate.

[0043] (3) Hardness (25% ILD hardness) The hardness (JIS K6400-2:2012 6.7 Method D) is preferably 10N-600N, more preferably 20N-400N, even more preferably 50N-400N, and still more preferably 100N-400N. (4) Rebound elasticity The rebound elasticity (JIS K6400-3:2011) is preferably 1%-80%, and more preferably 5%-70%. (5) Tensile strength, elongation, tear strength The tensile strength (JIS K6400-5:2012) is preferably 30 kPa or higher, more preferably 50 kPa or higher, and even more preferably 80 kPa or higher. The elongation (JIS K6400-5:2012) is preferably 50%-500%, but may be 80% or more, or 100% or more. The tear strength (JIS K6400-5:2012) is preferably 2 N / cm or higher, and more preferably 4 N / cm or higher. The upper limit of the tear strength is not particularly limited and may be, for example, 10 N / cm or lower. (6) Number of cells The number of cells (JIS K6400-1:2004) is preferably 10-70 (cells / 25mm), more preferably 20-60 (cells / 25mm), and even more preferably 30-50 (cells / 25mm).

[0044] 4. Polyurethane foam (Part 2) Polyurethane foam (part 2) is a polyurethane foam obtained from a composition containing a polyol, an isocyanate, and an ionic compound. The hardness of the polyurethane foam, measured according to JIS K 6400-2:2012 6.7D method, is between 20N and 400N. The anion of the ionic compound is a fluorine-containing anion. The hardness of the polyurethane foam is more preferably 50N-400N, and even more preferably 100N-400N.

[0045] The density of polyurethane foam (part 2) is arbitrary. Except for the fact that the hardness is within the above range and the density is arbitrary, polyurethane foam (part 2) is the same as polyurethane foam (part 1), and therefore its explanation is omitted. In other words, the explanations of "polyols," "ionic compounds," "isocyanates," etc., explained in the "Polyurethane Foam (Part 1)" section are applied directly to polyurethane foam (part 2). The preferred range for the density of polyurethane foam (part 2) is the range described in "(2) Density (Apparent Density)" in the "Polyurethane Foam (Part 1)" section.

[0046] 5. Effects and Uses of Polyurethane Foam Conventionally, electron conductors have been widely used as antistatic agents for polyurethane foam. Examples of electron conductors include carbon-based materials and metal nanoparticles. However, in order to ensure antistatic performance, a large amount of electron conductor may be required (for example, 20 parts by mass or more per 100 parts by mass of polyol). On the other hand, according to this embodiment, by using a specific ionic compound as the antistatic agent, the desired antistatic performance can be achieved even with a relatively small blending ratio. Furthermore, by reducing the blending ratio of the antistatic agent, various physical properties such as density and 25% ILD hardness can be suitably ensured. Furthermore, since many electronic conductors are made from powdered raw materials, there is a concern that handling antistatic agents will be complicated. According to this embodiment, by using ionic compounds that are liquid at room temperature or ionic compounds that are soluble in a solvent, the handling of antistatic agents is made easier.

[0047] The polyurethane foam of this embodiment can be used in a variety of applications as a low-static polyurethane foam. For example, the polyurethane foam of this embodiment is suitable as a cushioning material for packaging electronic components and electronic devices, a cushioning material for assembling electronic components and electronic devices, and a sealing material for electronic components and electronic devices. Furthermore, when polyurethane foam becomes electrically charged, it can stick to itself or attract dust, making it difficult to handle. The polyurethane foam of this embodiment has excellent antistatic properties, making it highly versatile as a polyurethane foam with excellent handling characteristics. Polyurethane foam can become electrically charged, for example, during cutting. The polyurethane foam of this embodiment is also useful, for example, as a polyurethane foam for cutting. [Examples]

[0048] 1. Sample preparation Table 1 shows the ionic compounds 1-25 used to prepare the samples. The following raw materials were mixed in the proportions shown in Tables 2 and 3, and then reacted and foamed to produce polyurethane foams for each example and comparative example. In Tables 2 and 3, blank spaces indicate that the amount of that raw material is "0 parts by mass".

[0049] Details of each raw material are as follows: The anions of ionic compounds 1-10 and 23 are fluorine-containing anions, while the anions of ionic compounds 11 and 22 are fluorine-free anions. • Ionic compound 1: bis(trifluoromethanesulfonyl)amide potassium, anion; formula (1-1) above • Ionic compound 2: 1-butyl-3-methylimidazolium = bis(trifluoromethanesulfonyl)amide, anion; formula (1-1) above • Ionic compound 3: 1-butyl-3-methylpyridinium = bis(trifluoromethanesulfonyl)amide, anion; formula (1-1) above • Ionic compound 4: Potassium hexafluorophosphate, anion; PF6 - • Ionic compound 5: 1-butyl-3-methylimidazolium hexafluorophosphate, anion; PF6 - • Ionic compound 6: Sodium tetrafluoroborate, anion; BF4 - • Ionic compound 7: 1-butyl-3-methylimidazolium tetrafluoroborate, anion; BF4 - • Ionic compound 8: Lithium trifluoromethanesulfonate, anion; CF3SO3 - • Ionic compound 9: 1-butyl-3-methylimidazolium trifluoromethanesulfonate, anion; CF3SO3 - • Ionic compound 10: 1-butyl-3-methylpyridinium trifluoromethanesulfonate, anion; CF3SO3 - • Ionic compounds 11: 3-nitrobenzenesulfonate sodium anion; 3-nitrobenzenesulfonate anion • Ionic compound 12: Sodium benzenesulfonate, anion; benzenesulfonate anion • Ionic compound 13: 1-butyl-3-methylimidazolium methanesulfonate, anion; CH3SO3 - • Ionic compound 14: Potassium lauryl anion; Lauryl anion • Ionic compound 15: Long-chain alkyl carboxylate salt of N,N-dihydroxyalkyl-N,N-dialkylammonium (manufactured by Kao Corporation, Kaolizer No. 420), anion; long-chain alkyl carboxylate anion • Ionic compound 16: N-(2-hydroxyethyl)-N-(2-hydroxypropyl)-N,N-dimethylammonium acetate (manufactured by Kao Corporation, Kaolizer No. 410), anion; CH3COO - • Ionic compound 17: Potassium acetate, anion; CH3COO - • Ionic compound 18: Potassium carbonate, anion; CO3 2- • Ionic compound 19: Sodium carbonate, anion; CO3 2- • Ionic compound 20: Quaternary ammonium nitrate (manufactured by Toho Chemical Industry Co., Ltd., Anstex C-200X), anion; NO3- • Ionic compound 21: 1-butyl-3-methylimidazolium bromide, anion; Br - • Ionic compound 22: Sodium chloride, anion; Cl - • Ionic compound 23: 1-ethyl-3-methylimidazolium=bis(trifluoromethanesulfonyl)amide, anion; formula (1-1) above

[0050] • Polyol: Polyether polyol, weight-average molecular weight 3000, number of functional groups 3, hydroxyl value 56 mgKOH / g • Foaming agent: Water • Amine catalyst: N,N-dimethylaminohexanol • Foam stabilizer: Silicone-based foam stabilizer ·Metal catalyst: stannous octylate • Isocyanate: TDI: A mixture of 2,4-TDI 80% and 2,6-TDI 20%

[0051] [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8]

[0052] 2. Evaluation Method The foaming properties of polyurethane foam manufactured using the above raw materials were evaluated. The foaming properties were evaluated by visual inspection of the appearance; a good appearance was rated "good," and an appearance defect due to poor foaming was rated "poor." Specifically, a good result was a polyurethane foam with a uniform shape, while a poor result was an uneven state such as cracking. Comparative Examples 3 and 6 showed poor foaming properties. Comparative Example 6 also exhibited shrinkage.

[0053] Test specimens were cut from polyurethane foam manufactured using the above raw materials, and the volume resistivity (JIS K6911), density (JIS K7222:2005), 25% ILD hardness (JIS K6400-2:2012 6.7 Method D), rebound elasticity (JIS K6400-3:2011), tensile strength, elongation, tear strength (both JIS K6400-5:2012), and cell count (JIS K6400-1:2004) were measured.

[0054] Furthermore, test specimens cut from polyurethane foams manufactured using the above raw materials, specifically from Examples 3, 9, 12, 16, 20, 21, 22 and Comparative Examples 4 and 14, were heat-treated at predetermined temperatures for 4 hours, and their volume resistivity was measured. The predetermined temperatures were 160°C, 170°C, 180°C, and 200°C. The measurement of volume resistivity was performed in accordance with JIS K6911, except for the heat treatment performed before measurement.

[0055] 3.Results The results are shown in Table 2-7. In Table 2-7, "-" indicates that no evaluation was performed. Examples 1-22, which used fluorine-containing anionic compounds, showed a volume resistivity of 5.0 × 10⁻⁶. 11 The volume resistivity was less than Ω·cm. On the other hand, comparative examples 1-5 and 7-14, which used fluorine-free anionic compounds, had a volume resistivity of 5.0 × 10⁻⁶. 11 It was larger than Ω·cm. Furthermore, Examples 1-22 have a density of 10 kg / m³. 3 More than 80kg / m 3 The results were as follows: Examples 1-22 had a hardness (25% ILD hardness) of 20N to 400N, measured in accordance with the JIS K 6400-2:2012 6.7D method for polyurethane foam. Examples 1-22 had tensile strength, elongation, tear strength, and cell count suitable for practical use.

[0056] Table 8 shows the volume resistivity of Examples 3, 9, 12, 16, 20, 21, 22 and Comparative Examples 4 and 14, as well as the volume resistivity after heat treatment (160°C, 170°C, 180°C, 200°C). Examples 3, 20, and 22, where the anionic species is bis(trifluoromethanesulfonyl)amide, did not show an increase in volume resistivity after heat treatment, demonstrating high temperature stability of volume resistivity. Examples 12, where the anionic species is tetrafluoroboric acid, and Example 16, where the anionic species is trifluoromethanesulfonic acid, also did not show an increase in volume resistivity after heat treatment, demonstrating high temperature stability of volume resistivity. These results suggest that anionic species such as bis(trifluoromethanesulfonyl)amide, tetrafluoroboric acid, and trifluoromethanesulfonic acid are suitable for the production of large polyurethane foams, for example, where the core tends to become hot during manufacturing.

[0057] 4. Effects of the Examples According to the above examples, it was possible to obtain a polyurethane foam that has good antistatic properties while ensuring the physical properties of the polyurethane foam.

[0058] This disclosure is not limited to the embodiments detailed above, and various modifications or alterations are possible.

Claims

1. A polyurethane foam obtained from a composition comprising a polyol, an isocyanate, and an ionic compound, The anion of the aforementioned ionic compound is a fluorine-containing anion. The cation of the ionic compound is a cation selected from the group consisting of imidazolium cations and phosphonium cations represented by the following formula (11): A polyurethane foam that satisfies both (A) and (B) below. (A) Density of 10 kg / m³ ３ More than 80kg / m ３ below (B) Hardness measured in accordance with JIS K 6400-2:2012 6.7D method is between 20N and 400N. 【Chemistry 1】 In formula (11), R4 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R 6 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R5, R7, and R8 are each independently of each other: hydrogen, methyl, or ethyl.

2. A polyurethane foam obtained from a composition comprising a polyol, an isocyanate, and an ionic compound, The anion of the aforementioned ionic compound is a fluorine-containing anion. The cation of the ionic compound is a cation selected from the group consisting of imidazolium cations and phosphonium cations represented by the following formula (11): The aforementioned ionic compound is an ionic liquid, A polyurethane foam that satisfies both (A) and (B) below. (A) Density of 10 kg / m³ ３ More than 80kg / m ３ below (B) Hardness measured in accordance with JIS K 6400-2:2012 6.7D method is between 20N and 400N. 【Chemistry 2】 In formula (11), R4 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R 6 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R5, R7, and R8 are each independently of each other: hydrogen, methyl, or ethyl.

3. A polyurethane foam obtained from a composition comprising a polyol, an isocyanate, and an ionic compound, The anion of the aforementioned ionic compound is a fluorine-containing anion. The cation of the ionic compound is a cation selected from the group consisting of imidazolium cations and phosphonium cations represented by the following formula (11): A polyurethane foam that satisfies the following conditions (B) and (C). (B) Hardness measured in accordance with JIS K 6400-2:2012 6.7D method is between 20N and 400N. (C) The volume resistivity measured after heat treatment at 200°C for 4 hours does not increase from the volume resistivity before heat treatment. 【Transformation 3】 In formula (11), R4 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R 6 is methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, or 2-cyanoethyl. R5, R7, and R8 are each independently of each other: hydrogen, methyl, or ethyl.

4. A cushioning material comprising the polyurethane foam described in any one of claims 1 to 3.

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