JP2024002575A - polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-density polyurethane foam that can be easily manufactured.

SOLUTION: A polyurethane foam is obtained from a composition containing polyols and polyisocyanates. The polyols contain a plant-derived polyol. The hydroxyl value of the plant-derived polyol is 130 mg KOH/g or less. The density based on JIS K7222 of the polyurethane foam is 25 kg/m³ or less.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

Application for application of Article 30, Paragraph 2 of the Patent Act Publisher: INOAC Corporation Sample provision location (distribution location): Techno Farm Keihanna, a factory of Spread Co., Ltd., an operating company of Earthside Co., Ltd. (Kizugawa City, Kyoto Prefecture) Kizugawadai 9-5-5) Sample provision date (distribution date): March 25, 2020

The present disclosure relates to polyurethane foams.

Patent Document 1 discloses a polyurethane foam obtained from a composition containing a plant-derived polyol. There is also a need for polyurethane foams for low density applications.

Japanese Patent Application Publication No. 2011-202026

In the polyurethane foam of Patent Document 1, a castor oil-derived polyol having a hydroxyl value of about 160 mgKOH/g is used as a raw material. By using a polyol with a relatively high hydroxyl value, the internal heat generation temperature during foaming tends to increase, making it difficult to manufacture. Therefore, there is a need for low density polyurethane foams that are easy to manufacture.
The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a low-density polyurethane foam that can be easily manufactured.
The present disclosure can be realized as the following forms.

[1] A polyurethane foam obtained from a composition containing polyols and polyisocyanates,
The polyols contain a plant-derived polyol,
The hydroxyl value of the plant-derived polyol is 130 mgKOH/g or less,
A polyurethane foam having a density based on JIS K7222 of 25 kg/m ³ or less.

The present disclosure provides low density polyurethane foams that are easily manufacturable.

Here, a desirable example of the present disclosure will be shown.

[2] A polyurethane foam having an isocyanate index of 91 or more.
[3] A polyurethane foam in which the polyols contain a petroleum-derived polyol, and the amount of the plant-derived polyol is 75 parts by mass or less when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass. .
[4] A polyurethane foam having a compressive residual strain of less than 8.5% in accordance with JIS K 6400-4 4.5.2.
[5] A polyurethane foam whose impact resilience according to JIS K 6400-3 is 25% or more and 45% or less.
[6] Polyurethane foam for bedding.

The present disclosure will be described in detail below. In addition, in this specification, descriptions using "-" for numerical ranges include the lower limit value and the upper limit value, unless otherwise specified. For example, the description "10-20" includes both the lower limit value "10" and the upper limit value "20". That is, "10-20" has the same meaning as "10 or more and 20 or less".

1. Polyurethane Foam Polyurethane foam is obtained from a polyurethane resin composition (hereinafter also simply referred to as a composition) containing polyols and polyisocyanates. Polyols include plant-derived polyols. It is preferable that the polyols contain a petroleum-derived polyol.

[Plant-derived polyol]
The plant-derived polyol contains, for example, castor oil. "Castor oil" in the present disclosure does not include modified castor oil and dehydrated castor oil, which will be described later. "Castor oil" in this disclosure means unmodified castor oil. Unmodified castor oil is extracted and purified from the seeds of castor bean belonging to the Euphorbiaceae family, and is not subjected to crosslinking (denaturation) treatment with dibasic acids or the like or dehydration treatment, which will be described later. Dehydrated castor oil is a drying oil obtained by dehydrating castor oil (non-drying oil). Castor oil is an ester of fatty acids and glycerin. Castor oil has ricinoleic acid as its main component, and contains other components such as unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and saturated fatty acids such as palmitic acid and stearic acid.

The plant-derived polyol may contain modified plant-derived oil or fat as a component using plant-derived oil or fat. An example of a modified plant-derived fat or oil is modified castor oil.

Modified plant-derived fats and oils such as modified castor oil are obtained by mixing a dibasic acid and plant-derived fats and oils and subjecting them to a dehydration condensation reaction so as to obtain the desired properties. Known methods can be used to synthesize this modified plant-derived oil and fat. For example, a dibasic acid is added after dissolving a vegetable oil or fat in an arbitrary solvent. This reaction solution is refluxed through a Dean-Stark trap to perform a dehydration condensation reaction while removing water produced by the reaction from the system. After the reaction is completed, the target compound can be obtained by removing the solvent under reduced pressure.

Examples of the dibasic acid include aliphatic dibasic acids, alicyclic dibasic acids, aromatic dibasic acids, and mixtures thereof. Examples of aliphatic dibasic acids include sebacic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, and tetradecanedioic acid. , pentadecanedioic acid, thapsic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, docosanedioic acid, tetracosanedioic acid, hexacosanedioic acid, octacosanedioic acid, maleic acid, fumaric acid, citraconic acid, itacone acids, mesaconic acid, muconic acid, or mixtures thereof.

Examples of the alicyclic dibasic acid include cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, tetrahydrophthalic acid, hymic acid, or mixtures thereof.

Examples of aromatic dibasic acids include terephthalic acid, isophthalic acid, phthalic acid, bibenzoic acid, tolylene dicarboxylic acid, xylene dicarboxylic acid, naphthalene dicarboxylic acid, biphenylene dicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, and dicarboxylic acid. Examples include phenoxyethane dicarboxylic acid, diphenylketone dicarboxylic acid, phenylindane dicarboxylic acid, or mixtures thereof.

Further, as the dibasic acid, a hydroxy dibasic acid containing a hydroxyl group in the molecule can also be used. Examples of hydroxy dibasic acids include tartronic acid, isomalic acid, hydroxymethylmalonic acid, dihydroxymalonic acid, malic acid, itamaric acid, citramalic acid, methylmalic acid, ethylmalic acid, dimethylmalic acid, trimethylmalic acid, tartaric acid, 2, 2- Dihydroxysuccinic acid, methyltartaric acid, dimethyltartaric acid, hydroxyglutaric acid, dihydroxyglutaric acid, trihydroxyglutaric acid, hydroxyadipic acid, dihydroxyadipic acid, hydroxypimelic acid, dihydroxypimelic acid, hydroxysuberic acid, hydroxy Azelaic acid, dihydroxyazelaic acid, hydroxysebacic acid, dihydroxysebacic acid, hydroxydodecanedioic acid, dihydroxydodecanedioic acid, hydroxybrassylic acid, hydroxytetradecanedioic acid, dihydroxyhexadecanedioic acid, hydroxyoctadecanedioic acid, dihydroxyoctadecanedioic acid, Furion Acid, hydroxyeicosanedioic acid, dihydroxyeicosanedioic acid, dihydroxyfumaric acid, dihydroxymaleic acid, hydroxycitraconic acid, hydroxymuconic acid, hydroxyclopentanedicarboxylic acid, hydroxycyclohexanedicarboxylic acid, hydroxytetrahydrophthalic acid, hydroxyterephthalic acid, Mention may be made of dihydroxyterephthalic acid, hydroxyisophthalic acid, dihydroxyisophthalic acid, hydroxyphthalic acid, dihydroxyphthalic acid, cuccinic acid, hydroxynaphthalene dicarboxylic acid, dihydroxynaphthalene dicarboxylic acid, hydroxydiphenylsulfone dicarboxylic acid, meconic acid or mixtures thereof.

Preferably, the dibasic acid includes sebacic acid. Sebacic acid is a plant-derived dibasic acid.

When the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the plant-derived polyol is preferably larger than 0 parts by mass, more preferably 30 parts by mass or more, and more preferably 40 parts by mass or more from the viewpoint of environmental friendliness. is even more preferable. When the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the plant-derived polyol is preferably 75 parts by mass or less, more preferably 65 parts by mass or less, and even more preferably 55 parts by mass or less, from the viewpoint of ensuring strength. preferable. From these points of view, when the total of petroleum-derived polyol and plant-derived polyol is 100 parts by mass, the plant-derived polyol is preferably greater than 0 parts by mass and 75 parts by mass or less, more preferably 30 parts by mass or more and 65 parts by mass or less. It is preferably 40 parts by mass or more and 55 parts by mass or less.

From the viewpoint of reaction acceleration, the hydroxyl value of the plant-derived polyol is preferably 40 mgKOH/g or more, more preferably 60 mgKOH/g or more, and even more preferably 80 mgKOH/g or more. From the viewpoint of suppressing heat generation during foaming, the hydroxyl value of the plant-derived polyol is 130 mgKOH/g or less, preferably 115 mgKOH/g or less, and more preferably 100 mgKOH/g or less. From these viewpoints, the hydroxyl value of the plant-derived polyol is 40 mgKOH/g or more and 130 mgKOH/g or less, preferably 60 mgKOH/g or more and 115 mgKOH/g or less, and more preferably 80 mgKOH/g or more and 100 mgKOH/g or less. Note that the hydroxyl value of a mixture of two or more types of plant-derived polyols is the value for the mixture as a whole.

[Petroleum-derived polyol]
The petroleum-derived polyol is not particularly limited. The petroleum-derived polyol is preferably larger than 0 parts by mass, more preferably 20 parts by mass or more, and 40 parts by mass when the total of petroleum-derived polyols and plant-derived polyols is 100 parts by mass. The above is more preferable. When the total of petroleum-derived polyol and plant-derived polyol is 100 parts by mass, the petroleum-derived polyol is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and still more preferably 60 parts by mass or less. preferable. From these viewpoints, when the total of petroleum-derived polyol and plant-derived polyol is 100 parts by mass, the petroleum-derived polyol is preferably greater than 0 parts by mass and 80 parts by mass or less, more preferably 20 parts by mass or more and 70 parts by mass or less. It is preferably 40 parts by mass or more and 60 parts by mass or less.

Examples of petroleum-derived polyols include polyether polyols, polymer polyols, polyester polyols, and the like.

Examples of polyether polyols include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose, and ethylene oxide (EO). ), polyether polyols to which alkylene oxides such as propylene oxide (PO) are added can be mentioned.

The polyether polyol is preferably a polyether polyol having a weight average molecular weight of 500-8000 (preferably 800-5000, more preferably 1000-3000) and a functional group number of 2-6 (preferably 2 or 3).

As the polymer polyol, for example, a polymer polyol obtained by graft copolymerizing a vinyl monomer such as acrylonitrile and styrene in a polyether polyol having two or three functional groups as a base polyol can be suitably used. Examples of the base polyol include polyether polyols containing PO units (propylene oxide units) and EO units (ethylene oxide units) as AO units (alkylene oxide units). Note that the weight average molecular weight of the polymer polyol means the weight average molecular weight of the base polyol.

As the polyester polyol, for example, polycaprolactone-based polyester polyol, adipate-based polyester polyol, etc. can be used. Examples of polycaprolactone-based polyester polyols include polyester polyols obtained by ring-opening addition polymerization of lactones such as ε-caprolactone. Examples of adipate polyester polyols include polyester polyols obtained by polycondensation of a polyfunctional carboxylic acid and a polyfunctional hydroxy compound. Polyester polyol also has the effect of making the cells of polyurethane foam fine and uniform.

[Other polyols]
Further, as the polyols, other polyols than the above-mentioned polyols may be contained. Other polyols may be used without particular limitation as long as they are polyols commonly used for polyurethane foams.

In the present disclosure, low molecular weight polymers such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, etc. When polyhydric alcohols are used, these polyhydric alcohols are also included in the polyols.

[Polyisocyanates]
Polyisocyanates are compounds having multiple isocyanate groups, such as tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate, and xylene diisocyanate. Aromatic isocyanates such as diisocyanate (XDI), alicyclic isocyanates such as isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate, aliphatic isocyanates such as hexamethylene diisocyanate (HDI), or by reaction with polyols. Modified isocyanates such as free isocyanate prepolymers and carbodiimide-modified isocyanates can be used. Further, these polyisocyanates may be contained alone or in combination of two or more types.

The polyisocyanates may be aromatic, alicyclic, or aliphatic isocyanates, and may be difunctional isocyanates having two isocyanate groups in one molecule, or It may be a trifunctional or higher functional isocyanate having three or more isocyanate groups, and they may be used alone or in combination. For example, as bifunctional isocyanates, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'- Aromatic ones such as dimethoxy-4,4'-biphenylene diisocyanate, alicyclic ones such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexane diisocyanate, butane Examples include aliphatic ones such as -1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, and lysine isocyanate. Furthermore, as the isocyanate having two or more functionalities, polymethylene polyphenylisocyanate (polymeric MDI) can be mentioned. Examples of trifunctional or more functional isocyanates include 1-methylbenzole-2,4,6-triisocyanate, 1,3,5-trimethylbenzole-2,4,6-triisocyanate, and biphenyl-2,4,4'-triisocyanate. Isocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'tetraisocyanate, triphenylmethane -4,4',4"-triisocyanate, etc. Also, the number of isocyanates is not limited to one type, but two or more types may be used. For example, one type of aliphatic isocyanate and one type of aromatic isocyanate can be mentioned. Two types of group-based isocyanates may be used together.

The isocyanate index is the equivalent ratio of isocyanate groups in polyisocyanates to reactive groups such as hydroxyl groups that can react with isocyanates in polyols. Therefore, if the value is less than 100, it means that reactive groups such as hydroxyl groups are in excess of isocyanate groups, and if it exceeds 100, it means that isocyanate groups are in excess of reactive groups such as hydroxyl groups. . From the viewpoint of reaction stability, the isocyanate index (INDEX) of the polyisocyanate is preferably 91 or more, more preferably 93 or more, and even more preferably 95 or more. From the viewpoint of suppressing heat generation during foaming, the isocyanate index (INDEX) of the polyisocyanate is preferably 125 or less, more preferably 115 or less, and even more preferably 110 or less. From these viewpoints, the isocyanate index (INDEX) of the polyisocyanate is preferably 91 or more and 125 or less, more preferably 93 or more and 115 or less, and even more preferably 95 or more and 110 or less.

[catalyst]
Preferably, the composition includes a catalyst. The catalyst is mainly for promoting the urethanization reaction between polyols and polyisocyanates. As the catalyst, known catalysts commonly used for polyurethane foam, such as triethylenediamine, N,N-dimethylaminoethanol, 6-dimethylamino-1-hexanol, N,N',N'-trimethylaminoethylpiperazine, etc. tertiary amines, stannous octoate, organometallic compounds such as stannous octylate, acetates, and alkali metal alcoholates can be used.

The content of the catalyst in the composition is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass. If this content is 0.1 part by mass or more, the urethanization reaction can be sufficiently promoted. When the amount is 5.0 parts by mass or less, it is possible to suppress the formation of a cell structure from becoming non-uniform due to excessive promotion of the urethanization reaction.

[Foam stabilizer]
Preferably, the composition contains a foam stabilizer. The foam stabilizer is not particularly limited. Foam stabilizers include, for example, organopolysiloxanes, organopolysiloxane-polyoxyalkylene copolymers, polyalkenylsiloxanes having polyoxyalkylene side chains, silicone-based compounds such as silicone-grease copolymers, and sodium dodecylbenzenesulfonate. , anionic surfactants such as sodium lauryl sulfate, polyether siloxanes, phenolic compounds, and the like are preferred. These foam stabilizers may be used alone or in combination of two or more. The blending amount of the foam stabilizer is not particularly limited. The blending amount of the foam stabilizer is preferably 0.03 parts by mass or more and 5.0 parts by mass or less, when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass.

[Foaming agent]
Preferably, the composition includes a blowing agent. The blowing agent is not particularly limited. As the blowing agent, for example, water, carbon dioxide, hydrohaloolefin, etc. are suitably used. When the blowing agent is water, the amount added is determined within a range that provides the desired density and good foaming state in the polyurethane foam, and usually when the total of petroleum-derived polyol and plant-derived polyol is 100 parts by mass. , preferably 1 part by mass or more and 10 parts by mass or less.

Examples of the hydrohaloolefins include hydrofluoroolefins (HFO) and hydrochlorofluoroolefins (HCFO). The content of the hydrohaloolefin is preferably greater than 0 parts by mass and 25 parts by mass or less, when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass.

[Other ingredients]
The composition may contain other components other than those listed above, if necessary. Other components include, for example, antioxidants, ultraviolet absorbers, thickeners, plasticizers, antibacterial agents, and colorants. Examples of antioxidants include dibutylhydroxytoluene and hindered phenol antioxidants, but from the perspective of reducing the content of volatile organic compounds, hindered phenol antioxidants with a molecular weight of 300 or more are used. It is particularly preferred to use Thickeners include, for example, calcium carbonate, aluminum hydroxide, and magnesium hydroxide.

2. Requirements Regarding Density In polyurethane foam, the density according to JIS K 7222 is preferably 30 kg/m ³ or less, more preferably 27 kg/m ³ or less, even more preferably 25 kg/m ³ or less, and particularly preferably 24 kg/m ³ or less. In polyurethane foam, the density according to JIS K 7222 is usually 5 kg/m ³ or more.

3. Requirements regarding compression residual strain In polyurethane foam, the compression residual strain according to JIS K 6400-4 4.5.2 A method is preferably less than 10%, more preferably less than 8.5%, and even more preferably less than 5%. In polyurethane foam, the compressive residual strain according to JIS K 6400-4 4.5.2 A method is usually 0.5% or more.

4. Requirements regarding rebound modulus In polyurethane foam, the rebound modulus based on a rebound test based on JIS K6400-3 is preferably 10% or more, more preferably 25% or more, and even more preferably 30% or more. In the polyurethane foam, the rebound modulus based on a rebound test according to JIS K6400-3 is preferably 80% or less, more preferably 60% or less, and even more preferably 45% or less. From these viewpoints, in polyurethane foam, the rebound modulus based on a rebound test based on JIS K6400-3 is preferably 10% or more and 80% or less, more preferably 25% or more and 60% or less, and 30% or more and 45% or less. More preferred.

5. Requirements regarding elongation In polyurethane foam, elongation according to JIS K6400-5 5 is preferably 80% or more, more preferably 90% or more, and even more preferably 100% or more. In polyurethane foam, the elongation according to JIS K6400-5 5 is usually 500% or less.

6. Requirements regarding hardness In polyurethane foam, the hardness according to JIS K6400-2 6.7 D method is preferably 20N or more, more preferably 40N or more, and even more preferably 60N or more. In the polyurethane foam, the hardness according to JIS K6400-2 6.7 D method is preferably 300N or less, more preferably 200N or less, and even more preferably 150N or less. From these viewpoints, the hardness of the polyurethane foam according to JIS K6400-2 6.7 D method is preferably 20N or more and 300N or less, more preferably 40N or more and 200N or less, and even more preferably 60N or more and 150N or less.

7. Requirements regarding ventilation rate In polyurethane foam, the ventilation rate according to JIS K6400-7 is preferably 30 L/min or more, more preferably 40 L/min or more, and even more preferably 50 L/min or more. In polyurethane foam, the air permeability according to JIS K6400-7 is usually 300 L/min or less.

8. Requirements regarding the degree of biomass based on the mixing ratio of raw materials The degree of biomass based on the mixing ratio of raw materials in polyurethane foam (hereinafter also referred to as the biomass degree of raw materials) is calculated using the following formula (1). In formula (1), "the number of parts added of the plant-derived polyol" is the total number of parts added of all the plant-derived polyols when a plurality of types of plant-derived polyols are used. The "number of parts added of plant-derived polyol" includes the number of parts added of any of the following materials: unmodified castor oil, modified castor oil, and dehydrated castor oil. In the "number of parts added of plant-derived polyol", if the degree of plantification of the plant-derived polyol is less than 100%, the number of parts added of the plant-derived polyol is multiplied by the degree of plantification. Here, the degree of vegetableization is the proportion of plant-derived materials in the raw materials. In formula (1), "the total number of parts added of the polyurethane resin composition" is the total number of parts added of all raw materials contained in the polyurethane resin composition. All raw materials are plant-derived polyols, petroleum-derived polyols, catalysts, foam stabilizers, blowing agents, polyisocyanates, and other raw materials (crosslinking agents, antibacterial agents, pigments, flame retardants, etc.). The gas loss in formula (1) is calculated using the following formula (2) when water is used as a foaming agent. In formula (2), "18" is the molecular weight of water, and "44" is the molecular weight of carbon dioxide. Note that when the polyurethane resin composition contains HFO as a blowing agent, the degree of biomass in the polyurethane foam is calculated using the following formula (3), assuming that all the HFO is volatilized during the reaction. The units of "number of parts added of plant-derived polyol", "total number of parts added of polyurethane resin composition" and "number of parts added of HFO" are parts by mass.

In polyurethane foam, the biomass degree of the raw material is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more.

9. Requirements regarding biomass degree by AMS method The biomass degree of polyurethane foam is also determined by the value measured by accelerator mass spectrometry (AMS method) based on ASTM D6866-21. Measure the carbon-14 concentration in polyurethane foam and the standard material for carbon-14 concentration in the atmosphere in 1950, and calculate the biomass level by the ratio. However, since the current carbon-14 concentration in the atmosphere is increasing year by year, a coefficient is applied to the carbon-14 concentration value for correction. By calculating the biomass degree according to ASTM D6866-21, the biomass degree is calculated using the atmospheric correction factor for 2021, REF (pMC) = 100.0.

The biomass degree of the polyurethane foam measured by the AMS method based on ASTM D6866-21 (hereinafter also referred to as the biomass degree by the AMS method) is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more.

10. Method for Producing Polyurethane Foam Polyurethane foam can be produced by a known foaming method in which a polyurethane resin composition is stirred and mixed to cause a polyol and a polyisocyanate to react. Foaming methods include slab foaming, mold foaming, etc., and any molding method may be used. Slab foaming is a method in which a mixed polyurethane resin composition is discharged onto a belt conveyor and foamed at room temperature under atmospheric pressure. On the other hand, mold foaming is a method in which a mixed polyurethane resin composition is filled into a mold and foamed within the mold.

11. Application of polyurethane foam Polyurethane foam is suitable for bedding. For example, polyurethane foam can be used in mattresses, comforters, mattresses, pillows, and the like. Further, for example, polyurethane foam can be used as a cushioning material, a sound absorbing material, a kitchen sponge, a culture medium for hydroponic cultivation of plants, and the like.

12. Actions and Effects of the Present Embodiment The present embodiment can provide a low-density polyurethane foam with good foamability.
In the polyurethane foam of this embodiment, the internal heat generation temperature during foaming can be lowered, making manufacturing easier.
In the polyurethane foam of this embodiment, the degree of biomass can be increased.
In the polyurethane foam of this embodiment, the compressive residual strain can be reduced.
The polyurethane foam of this embodiment can have increased elongation.

Next, the above embodiment will be described in more detail by giving Examples and Comparative Examples.
1. Production of polyurethane foam Polyurethane resin compositions blended in the ratios shown in Tables 1 and 2 were prepared, and polyurethane foams of Examples and Comparative Examples were produced by slab foaming.

In Tables 1 and 2, the numerical values of each component without a unit other than the index represent parts by mass.
Various information regarding petroleum-derived polyols 1-3 and plant-derived polyols 1 and 2 is shown in Table 3 below.
Plant-derived polyol 2 is a castor oil-derived polyol with a degree of vegetableization of 100%, consisting of plant-derived polyol 1: sebacic acid = 2 mol: 1 mol. Note that sebacic acid is a derivative of castor oil and has a degree of vegetable conversion of 100%. Plant-derived polyol 2 is prepared by charging 100 parts by weight of plant-derived polyol 1 and 10.9 parts by weight of sebacic acid into a glass reactor equipped with a stirrer, a temperature controller, etc., and then heating the mixture at a predetermined temperature for a predetermined period of time. This is a compound produced by reacting with stirring.
The "OHV" column in Table 3 indicates the hydroxyl value. In Example 2, the OHV of the plant-derived polyol containing 20 parts by mass of plant-derived polyol 1 and 25 parts by mass of plant-derived polyol 2 is 121.1 mgKOH/g. "Mw" indicates weight average molecular weight. "Mn" indicates number average molecular weight.

The specific contents of the catalyst, foam stabilizer, blowing agent, and polyisocyanate in Tables 1 and 2 are shown below.
Catalyst 1: Aliphatic tertiary amine (manufactured by Evonik Japan, DABCO 33LSI)
Catalyst 2: Stannous octylate (manufactured by Johoku Kagaku Kogyo Co., Ltd., MRH-110)
Foam stabilizer: Organic-containing silicone (manufactured by Dow Corning Toray, SZ-1136)
Foaming agent: Hydrofluoroolefin (Mitsui Chemours Fluoro Products Co., Ltd., Opteon ^TM 1100 Foam Expansion Agent)
Polyisocyanate: toluene diisocyanate (TDI) with a mixing ratio of 2,4/2,6 isomers of 80/20 (manufactured by Tosoh Corporation, Coronate T-80)

2. Evaluation Next, the polyurethane foams of the obtained Examples and Comparative Examples were evaluated as follows.

[Biomass degree based on the blending ratio of raw materials]
The biomass degree based on the blending ratio of raw materials was calculated using the above formulas (1) to (3). The calculation results are shown in the "Biomass content of raw material" column in Tables 1 and 2.

[Biomass degree by AMS method]
The biomass degree by the AMS method was determined by measurement using accelerator mass spectrometry (AMS method) based on ASTM D6866-21. The biomass degree was calculated using the atmospheric correction factor for 2021, REF (pMC) = 100.0. The calculation results are shown in the "Biomass degree by AMS method" column in Tables 1 and 2.

[Foamability]
The foamability of polyurethane foam was evaluated based on the following criteria.
"B": Good foaming.
"C": Foaming is poor.

[Internal temperature]
The internal temperature of polyurethane foam during foaming was evaluated based on the following criteria.
"B": Less than 160℃ "C": More than 160℃

[density]
The density of the polyurethane foam was determined by a measuring method based on JIS K 7222. The measurement results are shown in the "density" column of Tables 1 and 2.
The density of polyurethane foam was evaluated based on the following criteria.
"B": 25kg/ ^m3 or less "C": Greater than 25kg/ ^m3

[stretch]
The elongation of the polyurethane foam was determined by a measuring method based on JIS K 6400-55. The measurement results are shown in the "Elongation" column of Tables 1 and 2.
The elongation of polyurethane foam was evaluated based on the following criteria.
"A": 100% or more "B": 80% or more and less than 100% "C": Less than 80%

[Repulsion modulus]
The rebound modulus of the polyurethane foam was determined by a measuring method based on JIS K 6400-3. The measurement results are shown in the "Repulsion Resilience Modulus" column of Tables 1 and 2.
The evaluation of the impact resilience of polyurethane foam was based on the following criteria.
"A": 30% or more "B": 25% or more and less than 30% "C": Less than 25%

[Hardness]
The hardness of the polyurethane foam was determined by a measuring method based on JIS K 6400-2 6.7 D method. The measurement results are shown in the "Hardness" column of Tables 1 and 2.
The hardness of polyurethane foam was evaluated based on the following criteria.
"B": 20N or more and 300N or less "C": Less than 20N or greater than 300N

[Airflow amount]
The air permeability of the polyurethane foam was determined by a measuring method based on JIS K 6400-7. The measurement results are shown in the "Aeration amount" column of Tables 1 and 2.
The air permeability of polyurethane foam was evaluated based on the following criteria.
"A": 50L/min or more "B": 30L/min or more but less than 50L/min "C": Less than 30L/min

[Compression residual strain]
The compressive residual strain of the polyurethane foam was determined by a measuring method based on JIS K 6400-4 4.5.2 A method. The measurement results are shown in the "compression residual strain" column of Tables 1 and 2.
The compression residual strain of polyurethane foam was evaluated based on the following criteria.
"A": Less than 5% "B": 5% or more and less than 10% "C": 10% or more

[comprehensive evaluation]
"A": "Evaluation of foamability""Evaluation of internal temperature""Evaluation of density" None of the evaluations are ``C''. ``B'': ``Evaluation of foamability'', ``Evaluation of internal temperature'', ``Evaluation of density'', ``Evaluation of elongation'', ``Evaluation of rebound modulus'', ``Evaluation of hardness'', Either “Evaluation of ventilation amount” or “Evaluation of compressive residual strain” is “C”.

3. Results In both Example 1-12 and Comparative Example 1-3, the "evaluation of density" was "B". In Example 1-12 and Comparative Example 1-3, the polyurethane resin composition contained a plant-derived polyol containing castor oil or modified castor oil, but the density was a low value of 25 kg/m ³ or less.

Example 1-12 satisfies both requirements (a) and (b) below. Comparative Examples 1 and 2 do not meet the following requirement (b). Comparative Example 3 does not meet the following requirement (a).
- Requirement (a): The hydroxyl value of the plant-derived polyol is 130 mgKOH/g or less.
- Requirement (b): When the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the plant-derived polyol is 75 parts by mass or less.
In Examples 1-12, the "overall evaluation" was "A". In Example 1-12, by satisfying the above requirements (a) and (b), it was possible to reduce the internal temperature of the polyurethane foam during foaming while improving the physical properties (resilience modulus, air flow rate, compression residual strain). Ta.

4. Effects of Examples According to the above examples, a low-density polyurethane foam with good foamability can be produced.
It was possible to lower the internal heat generation temperature during foaming, and it was easy to manufacture.
We were able to increase the biomass content of polyurethane foam.
We were able to increase the rebound elasticity of polyurethane foam.
We were able to increase the amount of ventilation in the polyurethane foam.
We were able to reduce the compressive residual strain of polyurethane foam.

The present disclosure is not limited to the embodiments detailed above, and various modifications and changes can be made within the scope of the claims of the present disclosure.

Claims (6)

A polyurethane foam obtained from a composition containing polyols and polyisocyanates,
The polyols contain a plant-derived polyol,
The hydroxyl value of the plant-derived polyol is 130 mgKOH/g or less,
A polyurethane foam having a density based on JIS K7222 of 25 kg/m ³ or less. The polyurethane foam according to claim 1, having an isocyanate index of 91 or more. The polyols contain a petroleum-derived polyol,
The polyurethane foam according to claim 1 or 2, wherein the plant-derived polyol is 75 parts by mass or less when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass. The polyurethane foam according to claim 1 or 2, having a compressive residual strain of less than 8.5% according to JIS K 6400-4 4.5.2. The polyurethane foam according to claim 1 or 2, having a rebound resilience according to JIS K 6400-3 of 25% or more and 45% or less. The polyurethane foam according to claim 1 or 2, which is used for bedding.