JP7634392B2 - Polyurethane foam - Google Patents

Description

This disclosure relates to polyurethane foams.

Generally, soft urethane foam has high electrical resistance (volume resistivity) and is prone to generating static electricity. Therefore, antistatic foams have been proposed that lower the volume resistivity by adding antistatic agents (see, for example, Patent Documents 1-3). Examples of antistatic agents that have been used include quaternary ammonium salts, cationic/nonionic surfactants, alkylamines, and conductive carbon.

Japanese Patent Application Publication No. 6-173939 JP 2005-114043 A JP 2006-154537 A

However, most antistatic agents are expensive.
The present disclosure has been made in view of the above-mentioned circumstances, and has an object to suppress the generation of static electricity without using an antistatic agent. The present disclosure can be realized in the following aspects.

At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The polyurethane foam composition includes one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts.

This disclosure makes it possible to suppress the generation of static electricity.

Here, a preferred example of the present disclosure is given.
[2] A polyurethane foam, wherein the compound has a solubility of 80 or more in 100 g of water at 20°C.

[3] One or more metals selected from the group consisting of alkali metals and alkaline earth metals are detected by qualitative analysis;
A polyurethane foam having an apparent density of 50 kg/m3 or ^less .

[4] A polyurethane foam having a volume resistivity measured in accordance with JIS K6911 of 1×10 ¹⁴ Ωcm or less.

The present disclosure is described in detail below. In this specification, when a numerical range is described using "to" it is intended to include the lower limit and the upper limit unless otherwise specified. For example, the description "10 to 20" is intended to include both the lower limit "10" and the upper limit "20". In other words, "10 to 20" has the same meaning as "10 or more and 20 or less".

1. Polyurethane foam (part 1)
The polyurethane foam is obtained from a composition (hereinafter also referred to as "polyurethane resin composition") obtained by mixing at least a polyol, a foam stabilizer, a blowing agent, and an isocyanate. The polyurethane foam has an apparent density of 50 kg/ ^m3 or less. The polyurethane resin composition contains one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts.

(1) Polyol The polyol is not particularly limited. Various polyols may be used alone or in combination of two or more kinds.
Examples of the polyol include polyether polyol, polyester polyol, polyether ester polyol, polycarbonate diol, and polyol having a carbon-carbon bond main chain.
Examples of the polyether polyol include polyoxypropylene-polyoxyethylene polyol, polymer polyol, and polyoxytetramethylene glycol.
Examples of the polyester polyol include aliphatic or aromatic polycondensation polyester polyols and polycaprolactone polyols.
Examples of polyols having a carbon-carbon bond main chain include polyolefin polyols such as polybutadiene polyol and isoprene polyol, and acrylic polyols.

(1.1) Polyether Polyol Examples of polyether polyols include polyether polyols obtained by adding one or more of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, epichlorohydrin, styrene oxide, and the like to one or more of the following initiators (compounds), or polytetramethylene ether glycol.

(1.1.1) Initiator (1.1.1.1) Polyhydric alcohols and alkylene oxide adducts of polyhydric alcohols Examples of polyhydric alcohols:
[Difunctional alcohols] ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol [Trifunctional alcohols] glycerin, trimethylolpropane [Tetrafunctional alcohols] pentaerythritol [Hexafunctional alcohols] sorbitol [Octafunctional alcohols] sucrose (1.1.1.2) Alkylene oxide adducts of polyhydric phenols Example of alkylene oxide adducts of polyhydric phenols: alkylene oxide adducts of bisphenol A (1.1.1.3) Polyhydric hydroxy compounds Examples of polyhydric hydroxy compounds: phosphoric acid, benzene phosphoric acid, polyphosphoric acid (e.g. tripolyphosphoric acid and tetrapolyphosphoric acid), etc. (1.1.1.4) Phenol-aniline-formaldehyde ternary condensation products (1.1.1.5) Aniline-formaldehyde condensation products (1.1.1.6) Polyamines Examples of polyamines: ethylenediamine, diethylenetriamine, triethylenetetramine, methylenebisorthochloroaniline, 4,4- and 2,4'-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, etc. (1.1.1.7) Alkanolamines Examples of alkanolamines: triethanolamine, diethanolamine, etc.

(1.1.2) Polymer Polyol Polymer polyols are polyols obtained by graft polymerizing the above-mentioned polyether polyols with ethylenically unsaturated compounds such as acrylonitrile, styrene, and alkyl methacrylates.

(1.2) Polyester polyols Polyester polyols are polyester polyols obtained by condensation of one or more compounds having at least two hydroxyl groups with one or more compounds having at least two carboxyl groups, or ring-opening polymers of cyclic esters such as caprolactone and methylvalerolactone.

(1.2.1) Examples of compounds having at least two hydroxy groups: ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3- and 1,4-butanediol, tetramethylene glycol, neopentyl glycol, methylpentanediol, butylethylpropanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol

(1.2.2) Examples of compounds having at least two carboxyl groups: malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, pimelic acid, azelaic acid, sebacic acid, oxalic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and hemellitic acid.

(1.3) Polycarbonate Diols Examples of polycarbonate polyols include those obtained by transesterification of low molecular weight polyols such as butanediol and hexanediol with low molecular weight carbonates such as propylene carbonate and diethyl carbonate.

(1.4) Polyolefin-Based Polyols Examples of polyolefin-based polyols include polybutadiene polyols, polyisoprene polyols, hydrogenated polybutadiene polyols, and hydrogenated polyisoprene polyols.

(1.5) Plant-derived polyols In addition to the above polyols, the polyol may contain a plant-derived polyol. Examples of plant-derived polyols include castor oil-based polyols, soybean oil-based polyols, palm oil-based polyols, palm kernel oil-based polyols, coconut oil-based polyols, cashew oil-based polyols, olive oil-based polyols, cottonseed oil-based polyols, safflower oil-based polyols, sesame oil-based polyols, sunflower oil-based polyols, and linseed oil-based polyols. Plant-derived polyols usually have 2 to 3 functional hydroxyl groups in one molecule.
Examples of castor oil-based polyols include castor oil, a reaction product of castor oil with a polyol, an esterification reaction product of castor oil fatty acid with a polyol, etc. Examples of polyols to be reacted with castor oil or castor oil fatty acid include divalent polyols such as ethylene glycol, diethylene glycol, and propylene glycol, and trivalent or higher polyols such as glycerin, trimethylolpropane, hexanetriol, and sorbitol.
The soybean oil-based polyol may be a polyol derived from soybean oil, such as a reaction product of soybean oil and a polyol, or an esterification reaction product of soybean oil fatty acid and a polyol. The polyol to be reacted with soybean oil or soybean oil fatty acid may be the same as that of castor oil. The same applies to palm oil-based polyol, cashew oil-based polyol, etc. as to soybean oil-based polyol. The various polyols exemplified as plant-derived polyols may be used alone or in combination of two or more kinds.

(2) Catalyst A catalyst may be blended into the polyurethane resin composition. Any conventionally known catalyst may be used without any particular limitation. Various catalysts may be used alone or in combination of two or more kinds.
As the catalyst, an amine catalyst or a quaternary ammonium salt catalyst can be used. Specific examples of these catalysts are shown below.
Tertiary amine catalysts such as N,N-dimethylaminohexanol, triethylenediamine, triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, N,N-dimethylaminoethoxyethoxyethanol, and N,N-dimethylaminoethoxyethanol; formate and other salts of triethylenediamine; oxyalkylene adducts of amino groups of primary and secondary amines; azacyclic compounds such as N-N-dialkylpiperazines; various N,N',N'-trialkylaminoalkylhexahydrotriazines; and amine catalysts having an amino group as a functional group such as N,N,N",N"-tetramethyldiethylenetriamine.
Among the amine catalysts, reactive amine catalysts are preferred. The reactive amine catalyst has a functional group that reacts with isocyanate, and is preferably an amine compound having at least one OH group (for example, N,N-dimethylaminohexanol).
Further, quaternary ammonium salt catalysts such as tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide salts, and tetraalkylammonium organic acid salts such as tetramethylammonium 2-ethylhexanoate, 2-hydroxypropyltrimethylammonium formate, and 2-hydroxypropyltrimethylammonium 2-ethylhexanoate can also be used.
The amount of one or more catalysts selected from the group consisting of amine catalysts and quaternary ammonium salt catalysts in the polyurethane resin composition is not particularly limited. The amount (total amount) of these catalysts is preferably 0 parts by mass or more and 1 part by mass or less, more preferably 0 parts by mass or more and 0.5 parts by mass or less, and even more preferably 0 parts by mass or more and 0.3 parts by mass or less, relative to 100 parts by mass of polyol.

As the catalyst, a metal catalyst (organometallic catalyst) can be used. As the metal catalyst, any conventionally known metal catalyst can be used without any particular limitation.
As the metal catalyst, for example, metal salts of Sn (tin), Pb (lead), Bi (bismuth), Ni (nickel), Co (cobalt), Fe (iron), Zr (zirconium), Cu (copper), Zn (zinc), etc., organic acid metal salts, etc. can be used. More specifically, the following metal catalysts can be used.
Sn catalyst: tin(II) octoate (tin 2-ethylhexanoate, stannous dioctoate), tin(II) acetate, stannous diacetate, tin(II) octanoate, tin stannous dioleate, tin(II) neodecanoate, stannous dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, dibutyltin dimaleate, dioctyltin diacetate, etc. Pb catalyst: lead octoate, lead naphthenate, etc. Bi catalyst: bismuth octoate, bismuth naphthenate, bismuth neodecanoate, bismuth rosinate, etc. Fe catalyst: iron acetylacetonate, etc. Zr catalyst: zirconium acetylacetonate, etc. Ni catalyst: nickel acetylacetonate, nickel octoate, nickel naphthenate, etc. Co catalyst: cobalt acetylacetonate, cobalt octylate, cobalt naphthenate, etc.

The amount of the metal catalyst in the polyurethane resin composition is not particularly limited. The amount of the metal catalyst is preferably 0 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of polyol, from the viewpoint of sufficiently promoting the polyurethane production reaction. On the other hand, from the viewpoint of suppressing volatile organic compounds (such as 2-ethylhexanoic acid) derived from the metal catalyst, it is preferably 1.0 parts by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.30 parts by mass or less. From these viewpoints, the amount of the metal catalyst is preferably 0 parts by mass or more and 1.0 parts by mass or less, more preferably 0.01 parts by mass or more and 0.5 parts by mass or less, and even more preferably 0.05 parts by mass or more and 0.3 parts by mass or less, per 100 parts by mass of polyol.

(3) Foam Stabilizer The foam stabilizer is not particularly limited.
Specific examples of the foam stabilizer include silicone compounds (silicone foam stabilizers) such as organopolysiloxane, organopolysiloxane-polyoxyalkylene copolymer, polyalkenylsiloxane having a polyoxyalkylene side chain, silicone-grease copolymer, etc., anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, polyether siloxane, phenolic compounds, etc. These foam stabilizers may be used alone or in combination of two or more kinds.
The amount of the foam stabilizer is not particularly limited, but is preferably 0.03 parts by mass or more and 5.0 parts by mass or less based on 100 parts by mass of the polyol.

(4) Foaming agent The foaming agent is not particularly limited. As the foaming agent, water, pentane, cyclopentane, hexane, cyclohexane, dichloromethane (methylene chloride), carbon dioxide gas, etc. are preferably used. When the foaming agent is water, the amount added is determined within a range in which the desired density and good foaming state are obtained in the polyurethane foam, and usually, 1 part by mass or more and 5 parts by mass or less per 100 parts by mass of polyol is preferable.

(5) Isocyanate (Polyisocyanate)
The isocyanate is not particularly limited. At least one selected from the group consisting of aromatic isocyanates, alicyclic isocyanates, and aliphatic isocyanates is preferably used as the isocyanate. At least one aliphatic isocyanate and at least one aromatic isocyanate may be used in combination.
From the viewpoint of effectively suppressing static electricity, it is preferable to use an aromatic isocyanate having an electrically suitable aromatic ring (e.g., a benzene ring, etc.), and it is particularly preferable to use only aromatic isocyanates as the isocyanate.
The isocyanate may be either a bifunctional isocyanate having two isocyanate groups in one molecule, or a trifunctional or higher isocyanate having three or more isocyanate groups in one molecule, and may be used alone or in combination.
For example, bifunctional isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate. Examples of the isocyanate include aromatic isocyanates such as nylene diisocyanate, alicyclic isocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate, and aliphatic isocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, and lysine isocyanate.
Examples of tri- or higher functional isocyanates include 1-methylbenzene-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'tetraisocyanate, triphenylmethane-4,4',4"-triisocyanate, and polymeric MDI.
In addition, urethane prepolymers, carbodiimide-modified isocyanates, isocyanurate-modified isocyanates, and biuret-modified isocyanates can also be used.

The mixing ratio of isocyanate and polyol is not particularly limited. The isocyanate index is preferably 80 or more and 120 or less. The isocyanate index (INDEX) is the value obtained by multiplying the number of moles of isocyanate groups per mole of active hydrogen groups contained in the polyurethane resin composition by 100, and is calculated as [(isocyanate equivalent in composition/active hydrogen equivalent in composition) x 100].

(6) One or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts (6.1) Alkali Metal Salt Examples of the alkali metal constituting the alkali metal salt include potassium (K), sodium (Na), and lithium (Li).
The alkali metal salt may be any of a potassium salt, a sodium salt, and a lithium salt.
The potassium salt is not particularly limited. From the viewpoint of a high scavenging effect of volatile organic compounds such as 2-ethylhexanoic acid, examples of the potassium salt include inorganic acid salts and organic acid salts such as potassium benzoate, potassium chloride, potassium acetate, potassium oxalate, potassium carbonate, potassium hydrogen carbonate, potassium thiocyanate, tripotassium phosphate, dipotassium hydrogen phosphate, potassium laurate, potassium succinate, dipotassium adipate, and dipotassium malonate, and among these, one or more compounds selected from the group consisting of potassium carbonate, potassium hydrogen carbonate, potassium acetate, tripotassium phosphate, and potassium laurate are preferred.
The sodium salt is not particularly limited. From the viewpoint of a high scavenging effect of volatile organic compounds such as 2-ethylhexanoic acid, examples of the sodium salt include sodium benzoate, sodium chloride, sodium acetate, sodium oxalate, sodium carbonate, sodium hydrogen carbonate, trisodium phosphate, sodium hydrogen carbonate, sodium succinate, and disodium malonate, and among these, one or more compounds selected from the group consisting of sodium carbonate and sodium chloride are preferred.
The lithium salt is not particularly limited. From the viewpoint of a high scavenging effect of volatile organic compounds such as 2-ethylhexanoic acid, examples of the lithium salt include lithium benzoate, lithium chloride, lithium acetate, lithium oxalate, lithium carbonate, lithium hydrogen carbonate, lithium thiocyanate, lithium phosphate, and lithium hydrogen phosphate.

(6.2) Alkaline Earth Metal Salts Examples of alkali metals constituting alkaline earth metal salts include calcium (Ca) and magnesium (Mg).
The alkaline earth metal salt may be either a calcium salt or a magnesium salt.
The calcium salt is not particularly limited. From the viewpoint of a high effect of capturing volatile organic compounds such as 2-ethylhexanoic acid, examples of the calcium salt include calcium benzoate, calcium chloride, calcium acetate, calcium hydrogen carbonate, calcium lactate, and calcium dihydrogen phosphate, and among these, one or more compounds selected from the group consisting of calcium acetate and calcium lactate are preferred.
The magnesium salt is not particularly limited. As the magnesium salt, one or more compounds selected from the group consisting of magnesium chloride and magnesium acetate are preferred from the viewpoint of high scavenging effect of volatile organic compounds such as 2-ethylhexanoic acid.

(6.3) Solubility in water of one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts (hereinafter also referred to as "the compound"). The solubility in water of the compound is not particularly limited. The solubility of the compound in 100 g of water at 20°C is preferably 80 (g) or more, more preferably 100 (g) or more, and even more preferably 110 (g) or more, from the viewpoint of facilitating the production of polyurethane foam, enhancing the dispersibility of ions in the raw material solution and polyurethane foam, suppressing the generation of static electricity, and enhancing the effect of capturing volatile organic compounds such as 2-ethylhexanoic acid. The upper limit of the solubility of the compound in 100 g of water at 20°C is not particularly limited, but is usually 300 (g). The solubility of the compound in 100 g of water at 20°C is preferably 80 (g) or more and 300 (g) or less, more preferably 100 (g) or more and 300 (g) or less, and even more preferably 110 (g) or more and 300 (g) or less.

(6.4) Amount of one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts (hereinafter also referred to as "the compound") The amount of the compound in the polyurethane resin composition is not particularly limited, and may be any amount as long as it is blended. The amount of the compound is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, relative to 100 parts by mass of polyol, from the viewpoint of suppressing the generation of static electricity. On the other hand, from the viewpoint of maintaining the various physical properties of the polyurethane foam and from the viewpoint of production costs, it is preferably 3.0 parts by mass or less, more preferably 2.0 parts by mass or less, and even more preferably 1.0 parts by mass or less. From these viewpoints, the amount of the compound is preferably 0.01 parts by mass or more and 3.0 parts by mass or less, more preferably 0.1 parts by mass or more and 2.0 parts by mass or less, and even more preferably 0.3 parts by mass or more and 1.0 parts by mass or less, relative to 100 parts by mass of polyol.
In addition, it is considered that the effect of suppressing the generation of VOCs is influenced by the ratio of the amount of the compound to the metal catalyst tin octoate (tin compound). From this viewpoint, the amount of the compound is preferably 0.1 mol or more, more preferably 1 mol or more, and even more preferably 10 mol or more per 1.0 mol of tin octoate (tin compound).

(6.5) Other Additives The polyurethane resin composition may contain other additives as appropriate, such as crosslinking agents, plasticizers, flame retardants, fillers, antioxidants, UV absorbers, defoamers, compatibilizers, colorants, stabilizers, antibacterial agents, antifungal agents, deodorants, deodorants, fragrances, and flavorings. Examples of crosslinking agents include short-chain diol-based crosslinking agents such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, glycerin, and trimethylolpropane. Examples of coloring agents include pigments, dyes, and colorants.

(7) Volatile organic compound capture mechanism in polyurethane foam The mechanism of volatile organic compound capture will be explained. An example will be given of a polyurethane foam containing liquid tin octoate. In this case, 2-ethylhexanoic acid is produced from the tin octoate. In conventional formulations, 2-ethylhexanoic acid volatilizes from polyurethane foam and becomes a VOC. In the case of the polyurethane foam of this embodiment, it is presumed that "alkali metal ions (K ⁺ (potassium ion), Na ⁺ (sodium ion), Li ⁺ (lithium ion))" and "alkaline earth metal ions (Ca ²⁺ (calcium ion), Mg ²⁺ (magnesium ion))" derived from one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts combine (ionically bond) with 2-ethylhexanoic acid to produce potassium octoate, sodium octoate, lithium octoate, calcium octoate, magnesium octoate (hereinafter also referred to as "potassium octoate, etc."). Since this potassium octoate, etc. is a solid at room temperature, it does not volatilize, and it is presumed that the generation of VOCs is suppressed.

(8) Physical Properties of Polyurethane Foam The physical properties of the polyurethane foam can be appropriately set depending on the application, etc. The polyurethane foam is preferably a flexible polyurethane foam.
(8.1) Apparent density The apparent density (JIS K7222) is 50 kg/m ³ or less, preferably 40 kg/m ³ or less, and more preferably 30 kg/m ³ or less. The lower the density of the polyurethane foam, the more easily it becomes charged when it is cut with a blade or the like, so in the case of the above-mentioned low density, the static electricity suppression effect is more effectively exhibited. The lower limit of the apparent density is not particularly limited. From the viewpoint of suppressing the rise in heat generation temperature during foaming of a low-density product and stably producing it, the lower limit is preferably 10 kg/m ³ or more, and more preferably 15 kg/m ³ or more. From these viewpoints, the apparent density is preferably 10 kg/m ³ or more and 50 kg/m ³ or less, more preferably 15 kg/m ³ or more and 40 kg/m ³ or less, and even more preferably 15 kg/m ³ or more and 30 kg/m ³ or less.

(8.2) Volume resistivity The volume resistivity of the polyurethane foam is preferably 1× ^{10 Ωcm or less from the viewpoint of suppressing the generation of static electricity. The lower limit of the volume resistivity is not particularly limited. A suitable range of the volume resistivity is, for example, 1×10 Ωcm to 1×10 Ωcm .} Furthermore, in the case of a conductive foam, it is, for example, 1× ¹⁰ Ωcm to 1× ¹⁰ Ωcm.
The volume resistivity is measured under the following conditions in accordance with JIS K6911-1995 (5.13).
Measurement environmental conditions Temperature: 23℃ (±2℃)
Humidity: 50% (±5%)
Voltage: 500V

(8.3) Hardness The hardness (JIS K6400-2 D method) is preferably 10 N to 600 N, more preferably 20 N to 400 N. If it is 600 N or less, it is highly flexible and is preferable as a flexible polyurethane foam.

(8.4) Rebound Resilience The rebound resilience (JIS K6400-3) is preferably from 1% to 80%, and more preferably from 5% to 70%.

(8.5) Tensile Strength and Elongation The tensile strength (JIS K6400-5) is preferably 30 kPa or more, and more preferably 50 kPa or more.
The elongation (JIS K6400-5) is preferably 50% to 500%. If it is 50% or more, the polyurethane foam is highly flexible and is preferable as a flexible polyurethane foam.

2. Polyurethane foam (part 2)
In the polyurethane foam, one or more elements selected from the group consisting of alkali metals and alkaline earth metals are detected by qualitative analysis. The polyurethane foam is usually obtained from a composition ("polyurethane resin composition") containing at least a polyol, a foam stabilizer, a blowing agent, and an isocyanate.
Alkali metals can be detected by ICP emission spectrometry, while potassium can also be detected by XRF qualitative analysis.
The alkaline earth metals can be detected by ICP emission spectrometry.
If one or more selected from the group consisting of alkali metals and alkaline earth metals are detected in a qualitative analysis of a polyurethane foam, this means that one or more selected from the group consisting of alkali metals and alkaline earth metals remain in the polyurethane foam. In this case, there is a possibility that one or more selected from the group consisting of the above-mentioned alkali metal salts and alkaline earth metal salts remain, and the generation of static electricity is suppressed.
Incidentally, if the alkali metal content is 500 ppm or more, the generation of static electricity is sufficiently suppressed. The upper limit of the alkali metal content is usually 5,000 ppm or less.
When the alkaline earth metal content is 500 ppm or more, the generation of static electricity is sufficiently suppressed. The upper limit of the alkaline earth metal content is usually 5,000 ppm or less.
In polyurethane foam (part 2), the explanations in the "Polyurethane foam (part 1)" section apply as is to the "Polyurethane foam (part 2)" for "Polyurethane foam (part 1)," and the descriptions are omitted here. In other words, the "Polyol,""Catalyst,""Foamstabilizer,""Foamingagent," and "Isocyanate" explained in the "Polyurethane foam (part 1)" section apply as is.

The polyurethane foam of the present disclosure is not particularly limited in its applications. The polyurethane foam of the present disclosure is suitably used for food containers, packaging materials, sponges for hydroponic cultivation, furniture, bedding, household goods (kitchen sponges, etc.), and the like.

4. Production of polyurethane foam Polyurethane foam can be produced by a known foaming method in which a polyurethane resin composition is stirred and mixed to react with a polyol and an isocyanate. The foaming method includes slab foaming and mold foaming, and either molding method may be used. Slab foaming is a method in which a mixed polyurethane resin composition is discharged onto a belt conveyer and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a mixed polyurethane resin composition is filled into a mold (forming die) and foamed in the mold.

1. Production of Polyurethane Foams Polyurethane resin compositions having compositions formulated in the proportions shown in Tables 1 and 2 were prepared, and polyurethane foams of the examples and comparative examples were produced by slab foaming.
The details of each raw material are as follows:
・Polyol:
Polyether polyol, functionality 3, molecular weight 3000, hydroxyl value 56 mgKOH/g, product name: CARADOL56-16, manufactured by SHELL. Foaming agent:
Water Methylene chloride Alkali metal salts:
_{K2CO3 ​
CH3COOK}
Antistatic agent Elegan LD-204 manufactured by NOF Corporation Amine catalyst:
Kao Raiser No. 25 (N,N-dimethylaminohexanol) Kao Raiser No. 81 Kao Corporation TEDA33 (C ₆ H ₁₂ N ₂ , Triethylene Diamine) Tosoh Corporation U-CAT 18X (quaternary ammonium salt) San-Apro Co., Ltd., tin octylate catalyst (tin octylate catalyst) MRH110 Johoku Chemical Industry Co., Ltd., silicone foam stabilizer B8110 Evonik Co., Ltd., silicone foam stabilizer B8244 Evonik Co., Ltd., isocyanate: toluene diisocyanate (TDI) Coronate T-80 2,4/2,6 isomers mixed at a ratio of 80/20 Tosoh Corporation, isocyanate: toluene diisocyanate (TDI) Coronate T-65 2,4/2,6 isomers mixed at a ratio of 65/35 Tosoh Corporation

Specifically, the polyurethane foam was produced according to the following procedure.
The raw materials other than the isocyanate were weighed and mixed in a cup container to prepare a mixed solution. Metal salts such as potassium carbonate were dissolved in water and mixed with the polyol.
Isocyanate was added to the mixed solution and stirred to obtain a polyurethane resin composition.

2. Evaluation method (1) Apparent density (density)
The apparent density was measured according to JIS K7222 as described in section (8.1) above.
(2) Volume Resistivity Value The volume resistivity value was measured in accordance with JIS K6911-1995 as described in the above section (8.2).
(3) VOC Values For the measurement of the VOC values, a 7 mg test piece was prepared from each sample, the test piece was placed in a glass tube, and a thermal desorption device was used to carry out the VOC measurement method specified in "German Association of the Automotive Industry VDA278." Specifically, each test piece was heated at 90°C for 30 minutes, and the gas generated during heating was analyzed by a gas chromatograph mass spectrometer to calculate the VOC values.
(4) Sensory Test for Odor The following test method was used for the sensory test for odor.
Test method: A 100x100x10mm urethane foam sample was placed in an odorless 5L plastic bag and five people smelled the odor. Evaluation was performed using the following evaluation criteria. The results were the average of the five people. The odor in this test was mainly due to the raw materials.
<Evaluation criteria>
Odor Intensity 5: Intense odor 4: Strong odor 3: Easily detectable odor 2: Weak odor that is easy to identify 1: Detectable odor 0: No odor

- Quality of odor (pleasantness)
-3: Very unpleasant -2: Unpleasant -1: Slightly unpleasant 0: Neither pleasant nor unpleasant 1: Slightly pleasant 2: Comfortable 3: Very pleasant

3. Results The results are shown in Tables 1 and 2.

It was found that the polyurethane foams of Examples 1 to 7 had low volume resistivity and suppressed the generation of static electricity even without the use of an antistatic agent. The polyurethane foams of Examples 1 to 7 had volume resistivity values equivalent to that of Comparative Example 3, which used an antistatic agent. On the other hand, the polyurethane foams of Comparative Examples 1 and 2 had high volume resistivity values and were prone to generating static electricity.
The polyurethane foams of Examples 1, 4 and 5 had lower VOC measurement values than the polyurethane foams of Comparative Examples 1, 2 and 3.
The polyurethane foam of Example 1 was evaluated as being more favorable than the polyurethane foams of Comparative Examples 1 and 2 in the odor sensory test.

4. Effects of the Examples According to the above examples, it is possible to provide polyurethane foams in which the generation of static electricity is suppressed without using an antistatic agent. The polyurethane foams of the examples have an excellent effect of capturing volatile organic compounds. The polyurethane foams of the examples also suppress odors derived from the raw materials.

This disclosure is not limited to the embodiments detailed above, and various modifications and variations are possible within the scope of this disclosure.

Claims (8)

At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of potassium salts and alkaline earth metal salts ;
A polyurethane foam having a volume resistivity measured in accordance with JIS K6911 of 1×10 ¹⁴ Ωcm or less (excluding polyurethane foams having an isocyanate index of 150 or more). At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of potassium salts, sodium salts, and alkaline earth metal salts ;
A polyurethane foam having a volume resistivity of 1 x 10 ¹⁴ Ωcm or less, measured in accordance with JIS K6911 (excluding polyurethane foams having an isocyanate index of 150 or more , polyurethane foams containing sodium bicarbonate, polyurethane foams containing sodium carbonate, and polyurethane foams containing a sodium salt of an organic solid acid ). At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of potassium salts, lithium salts , and alkaline earth metal salts ;
A polyurethane foam having a volume resistivity of 1 x 10 ¹⁴ Ωcm or less as measured in accordance with JIS K6911 (excluding polyurethane foams containing a quaternary ammonium salt represented by the following general formula (I) in the composition and polyurethane foams having an isocyanate index of 150 or more).

R, R', R'', and R''' are each a group having 1 to 4 carbon atoms, and any of R, R', R'', and R''' has one or more reactive groups having active hydrogen that reacts with isocyanate. X is an anionic group. At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts ,
A polyurethane foam having a volume resistivity of 1 x ¹⁰ Ωcm or less, measured in accordance with JIS K6911 (excluding polyurethane foams containing a quaternary ammonium salt represented by the following general formula (I) in the composition, polyurethane foams having an isocyanate index of 150 or more , polyurethane foams containing sodium bicarbonate, polyurethane foams containing sodium carbonate, and polyurethane foams containing a sodium salt of an organic solid acid ):

R, R', R'', and R''' are each a group having 1 to 4 carbon atoms, and any of R, R', R'', and R''' has one or more reactive groups having active hydrogen that reacts with isocyanate. X is an anionic group. At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of potassium salts, sodium salts, and alkaline earth metal salts ;
The compound is a polyurethane foam having a solubility of 80 or more in 100 g of water at 20° C. (excluding polyurethane foams having an isocyanate index of 150 or more). At least a polyol;
A foam stabilizer,
A foaming agent;
A static suppression polyurethane foam obtained from a composition comprising a mixture of an isocyanate and
The apparent density is 50 kg/ ^m3 or less,
The composition includes one or more compounds selected from the group consisting of alkali metal salts and alkaline earth metal salts ;
The compound has a solubility of 80 or more in 100 g of water at 20°C (excluding polyurethane foams containing a quaternary ammonium salt represented by the following general formula (I) in the composition and polyurethane foams having an isocyanate index of 150 or more).

R, R', R'', and R''' are each a group having 1 to 4 carbon atoms, and any of R, R', R'', and R''' has one or more reactive groups having active hydrogen that reacts with isocyanate. X is an anionic group. One or more elements selected from the group consisting of potassium and alkaline earth metals are detected by qualitative analysis;
The apparent density is 50 kg/ ^m3 or less,
The volume resistivity measured in accordance with JIS K6911 is 1×10 ^Ωcm or less;
A polyurethane foam that satisfies at least one of the following (A) and (B):
(A) Hardness (JIS K6400-2 D method) is 10N to 600N.
(B) Elongation (JIS K6400-5) is 50% to 500%. One or more metals selected from the group consisting of alkali metals and alkaline earth metals are detected by qualitative analysis;
The apparent density is 50 kg/ ^m3 or less,
The volume resistivity measured in accordance with JIS K6911 is 1×10 ^Ωcm or less;
The method uses, as raw materials, at least one compound selected from the group consisting of alkali metal salts and alkaline earth metal salts (excluding potassium formate and sodium hydrogen carbonate ) and a polyol,
The amount of the compound is 2.0 parts by mass or less per 100 parts by mass of the polyol (excluding those using a quaternary ammonium salt represented by the following general formula (I) as a raw material).

R, R', R'', and R''' are each a group having 1 to 4 carbon atoms, and any of R, R', R'', and R''' has one or more reactive groups having active hydrogen that reacts with isocyanate. X is an anionic group.