Polyurethane foam

Abstract

Provided is a polyurethane foam which is obtained from a composition for polyurethane foam, the composition containing a polyol component, a polyisocyanate, a foaming agent and a catalyst. With respect to this polyurethane foam, the polyol component contains a plant-derived polyol and a polymer polyol; the plant degree, which is expressed by the percentage by weight of the plant-derived polyol contained in this composition for polyurethane foam, is 15% or more; and the air permeability (as determined by method A in accordance with JIS K6400-7 (2012)) is 10 L / min or less.

Description

Polyurethane foam

[0001] The present disclosure relates to polyurethane foams suitable as soundproofing materials.

[0002] For example, in automobiles, soundproofing materials made of polyurethane foam are placed in sound transmission paths around fenders, instrument panels, cowls, etc. to reduce the transmission of noise into the vehicle interior (Japanese Patent Application Laid-Open No. 2013-246182).

[0003] Generally, for soundproofing materials made of the same material, the heavier they are, the greater their soundproofing effect tends to be. However, in the case of automobiles, lightweight construction is required to improve fuel efficiency, so increasing the weight of polyurethane foam to improve soundproofing is not desirable. Furthermore, in recent years, in order to reduce environmental impact, there has been a demand for the use of plant-derived resins obtained from plant resources instead of petroleum-derived resins made from petroleum resources. The present disclosure has been made in consideration of the above points, and aims to provide a polyurethane foam that provides good soundproofing even when lightweight and contributes to reducing environmental impact.

[0004] In a first aspect, a polyurethane foam obtained from a polyurethane foam composition containing a polyol component, a polyisocyanate, a blowing agent, and a catalyst, the polyol component contains a plant-derived polyol and a polymer polyol, and the plant-derived polyol contained in the polyurethane foam composition has a plant-derived content, expressed as weight %, of 15% or more, and an air permeability (JIS K6400-7:2012A method) of 10 L / min or less.

[0005] In a second aspect, in the first aspect, the total amount of the plant-derived polyol and the polymer polyol in the polyol component is 86% by weight or more.

[0006] In a third aspect, in the first or second aspect, the average sound transmission loss (JIS A1441-1:2007) in a frequency range of 1000 to 6300 Hz is 30 dB or more.

[0007] The fourth aspect is any one of the first to third aspects, wherein the density is 100 to 160 kg / m３ is.

[0008] A fifth aspect is any one of the first to fourth aspects, wherein the surface hardness is an Asker C hardness of 30 or less.

[0009] According to the present disclosure, a polyurethane foam can be obtained that is lightweight yet has good soundproofing properties and contributes to reducing the environmental load.

[0010] 1 is a table showing the formulations of polyurethane foam compositions and the physical properties of the polyurethane foams of each Example and Comparative Example.

[0011] This application is based on Japanese Patent Application No. 2022-119350, filed on July 27, 2022, in Japan, the contents of which are incorporated herein by reference. The present invention will be more fully understood from the following detailed description. Further scope of application of the present invention will become apparent from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the present invention and are described for illustrative purposes only. From this detailed description, various changes and modifications will be apparent to those skilled in the art within the spirit and scope of the present invention. The applicant does not intend to dedicate any of the described embodiments to the public, and modifications and alternatives that may not literally fall within the scope of the claims are considered part of the invention under the doctrine of equivalents.

[0012] DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention provides a polyurethane foam comprising a polyol component, a polyisocyanate, a blowing agent, and a catalyst. The polyurethane foam is formed by reacting the polyol component with the polyisocyanate and foaming the polyurethane foam composition with the polyol component.

[0013] The polyol component includes a plant-derived polyol and a polymer polyol. The plant-derived polyol is a polyol produced using a plant-derived raw material, such as vegetable oil. The plant-derived polyol preferably has 2 to 4 functional groups and a molecular weight of 600 to 5,000, more preferably 800 to 4,000, and even more preferably 900 to 3,000.

[0014] Examples of vegetable oils as plant-derived raw materials include castor oil, sunflower oil, rapeseed oil, linseed oil, cottonseed oil, tung oil, coconut (palm) oil, poppy seed oil, corn oil, soybean oil, etc. Among these, castor oil polyol produced using castor oil as a raw material is a suitable example of the plant-derived polyol in the present disclosure.

[0015] The castor oil polyol may be either a modified castor oil polyol or an unmodified castor oil polyol, or may contain both. Examples of the modified castor oil polyol include a transesterification reaction product between castor oil and fats and oils other than castor oil, a transesterification reaction product between castor oil and fat fatty acids, a transesterification reaction product between castor oil and polyhydric alcohols, an esterification reaction product between castor oil fatty acids and polyhydric alcohols, an esterification reaction product between a portion of the hydroxyl groups contained in castor oil and monocarboxylic acids such as acetic acid, a reaction product obtained by addition polymerization of these with alkylene oxide, and a hydrogenated product obtained by adding hydrogen to these. Examples of the unmodified castor oil polyol include a refined castor oil polyol, a semi-refined castor oil polyol, and an unrefined castor oil polyol.

[0016] Multiple types of plant-derived polyols may be used. The amount of plant-derived polyol is, for example, preferably an amount that results in a plant-derived content of 15% or more, more preferably an amount that results in a plant-derived content of 20% or more, and even more preferably an amount that results in a plant-derived content of 25% or more. The plant-derived content (%) in the present disclosure is a value expressed as the weight % of the plant-derived polyol contained in the polyurethane foam composition, and is calculated by the formula: [plant-derived content (%) = (weight of plant-derived polyol / total weight of polyurethane foam composition) × 100].

[0017] Examples of polymer polyols include those obtained by graft polymerizing acrylonitrile, styrene, or the like onto polyether polyol and finely dispersing the acrylonitrile, styrene, or the like. The polymer polyol preferably has 2 to 4 functional groups and a molecular weight of 2,000 to 7,000, more preferably 2,500 to 6,500, and even more preferably 3,000 to 6,000. Two or more polymer polyols may be used in combination. By including a polymer polyol in the polyol component, excessive reduction in breathability of the polyurethane foam caused by plant-derived polyols can be mitigated. If the breathability of the polyurethane foam is too low, it becomes difficult to compress and deform, making it difficult to compress and insert / position into the sound transmission path. Furthermore, the foam may be prone to shrinkage during molding, resulting in poor moldability. The amount of polymer polyol is, for example, preferably 10 to 80 wt %, more preferably 20 to 70 wt %, and even more preferably 30 to 60 wt % per 100 wt % of the polyol component. The total amount of plant-derived polyol and polymer polyol in 100% by weight of the polyol component is, for example, preferably 86% by weight or more, more preferably 88% by weight or more, and even more preferably 90% by weight or more.

[0018] The polyol component may contain a petroleum-derived polyol in addition to the plant-derived polyol and polymer polyol. The inclusion of a petroleum-derived polyol improves the moldability and productivity of polyurethane foam. The petroleum-derived polyol in the present disclosure is a polyol other than the plant-derived polyol and polymer polyol, and may be any of polyether polyols, polyester polyols, polyether ester polyols, etc., and one or more of these may be used. The petroleum-derived polyol preferably has 2 to 4 functional groups and a molecular weight of 100 to 10,000, more preferably a molecular weight of 400 to 8,000, and even more preferably a molecular weight of 700 to 7,000. The amount of petroleum-derived polyol is the remainder of the plant-derived polyol and polymer polyol blended in 100% by weight of the polyol component, and is, for example, preferably less than 14% by weight, more preferably less than 12% by weight, and even more preferably less than 10% by weight.

[0019] The polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups, and those for polyurethane foams can be used. The polyisocyanate is not limited to one type, and two or more types may be used in combination. Examples of polyisocyanates include aromatic, aliphatic, and alicyclic isocyanate compounds, as well as modified products thereof.

[0020] Examples of aromatic isocyanate compounds include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate (TDI), naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI), and tolidine isocyanate (TODI). Examples of aliphatic isocyanate compounds include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), and lysine triisocyanate (LTI). Examples of alicyclic isocyanate compounds include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H6XDI), and hydrogenated MDI (H12MDI). Examples of modified isocyanate compounds include urethane-modified isocyanate compounds, dimers, trimers, carbodiimide-modified isocyanate compounds, allophanate-modified isocyanate compounds, biuret-modified isocyanate compounds, urea-modified isocyanurate-modified isocyanate compounds, oxazolidone-modified isocyanate compounds, and isocyanate-terminated prepolymers.

[0021] The amount of polyisocyanate blended is preferably an amount that results in an isocyanate index of 70 to 110. If the isocyanate index is less than 70, the polyurethane foam will have too low strength and poor durability, or it will be difficult for gas to escape, resulting in shrinkage and poor molding quality. On the other hand, if the isocyanate index exceeds 110, the polyurethane foam will have high hardness and will be less likely to deform into the shape of the mating surface. The isocyanate index is a value that indicates, as a percentage, the equivalent ratio of isocyanate groups in the polyisocyanate to the total active hydrogen groups in the polyurethane foam composition (e.g., hydroxyl groups in polyols, active hydrogen groups such as water used as a blowing agent), and is an index used in the field of polyurethane foam.

[0022] Examples of blowing agents include water, hydrocarbons, and halogenated compounds. These may be used alone or in combination of two or more. Examples of hydrocarbons include cyclopentane, isopentane, and normal pentane. Examples of halogenated compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, pentafluoroethyl methyl ether, and heptafluoroisopropyl methyl ether. Among these, water is preferred as a blowing agent. The amount of water used as a blowing agent is preferably about 1 to 10% by weight, more preferably about 1 to 7% by weight, based on 100% by weight of the polyol component, allowing for adjustment of the density of the polyurethane foam. Alternatively, the amount may be 1 to 10 parts by weight, or even 1 to 7 parts by weight, based on 100 parts by weight of the polyol component.

[0023] Examples of the catalyst include amine catalysts and metal catalysts. Examples of the amine catalyst include N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethylaminoethanol, N,N',N'-trimethylaminoethylpiperazine, and triethylenediamine. Examples of the metal catalyst include tin catalysts such as stannous octoate and dibutyltin dilaurate, phenylmercury propionate, and lead octenate. The amount of catalyst is preferably about 0.1 to 8.0% by weight based on 100 parts by weight of the polyol. Alternatively, it may be 0.1 to 8.0 parts by weight based on 100 parts by weight of the polyol.

[0024] In addition, additives such as a crosslinking agent, a foam stabilizer, a flame retardant, a colorant, etc. may be appropriately blended into the polyurethane foam composition.

[0025] Examples of crosslinking agents include polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, butanetetraol, and polyoxypropylene glycol, as well as diethanolamine and polyamine. The crosslinking agent is not limited to one type, and multiple types may be used in combination. The amount of crosslinking agent is preferably about 0.3 to 5 wt % per 100 wt % of the polyol component. Alternatively, it may be 0.3 to 5 parts by weight per 100 parts by weight of the polyol component.

[0026] The foam stabilizer may be any foam stabilizer that is used in polyurethane foams, including silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and known surfactants. Silicone-based foam stabilizers are particularly preferred.

[0027] The polyurethane foam of the present disclosure preferably has an air permeability (JIS K6400-7:2012A method) of 10 L / min or less, more preferably 6 L / min or less, even more preferably 5 L / min or less, and particularly preferably 4 L / min or less. By setting the air permeability within this range, good soundproofing properties can be obtained. The lower limit is preferably 1 L / min or more. If the air permeability of the polyurethane foam is too low, it becomes difficult to compress and deform, making it difficult to compress and insert or place it in the sound transmission path, and further, the foam may be more likely to shrink during molding, which may deteriorate moldability. Therefore, the lower limit of air permeability is preferably 1 L / min or more. JIS (Japanese Industrial Standards) are Japanese standards related to industrial and mineral products, processing technology, electromagnetic records, services, business management, etc.

[0028] The polyurethane foam of the present disclosure has an average sound transmission loss (JIS A1441-1:2007 / ISO 15186-1:2000) of 30 dB or more, preferably 32 dB or more, over a frequency range of 1000 to 6300 Hz. The larger the average sound transmission loss, the higher the sound insulation properties. The average sound transmission loss over a frequency range of 1000 to 6300 Hz is determined by measuring the sound transmission loss (JIS A1441-1:2007 / ISO 15186-1:2000) in a 1 / 3 octave band and averaging the sound transmission loss (average sound transmission loss) over a frequency range of 1000 Hz to 6300 kHz.

[0029] The polyurethane foam of the present disclosure has a density (JIS K7222:2005) of, for example, 170 kg / m ３ Preferably less than 160 kg / m ３ More preferably, less than 130 kg / m ３ By setting the density of the polyurethane foam within the above range, the polyurethane foam can be made lightweight.

[0030] The polyurethane foam of the present disclosure preferably has a surface hardness, as measured by Asker C hardness, of, for example, 30 or less, more preferably 20 or less, and even more preferably 10 or less. By setting the surface hardness of the polyurethane foam within this range, the polyurethane foam can easily adhere to the wall surface shape of the sound transmission path, thereby improving the soundproofing effect.

[0031] The polyurethane foam of the present disclosure preferably has a skin layer (coating layer) on its surface. The skin layer is a portion of the surface of the polyurethane foam that is denser than the inner (center) portion of the polyurethane foam. By having a skin layer, the polyurethane foam can reduce frictional resistance with the wall surface when inserted into a gap, making insertion and placement easier. Furthermore, the presence of the skin layer (coating layer) enhances the sound insulation effect.

[0032] The polyurethane foam of the present disclosure is produced by molding, in which the polyurethane foam composition is stirred and poured into a foam mold, where it is foamed. Molding is a widely used method for producing polyurethane foam, and by pre-forming the inner surface of the foam mold into the desired product shape, polyurethane foam can be obtained in the desired product shape without post-processing.

[0033] When molding polyurethane foam, a mold release agent is first applied to the inner surface of the foam molding mold using a brush or spray. The foam molding mold is equipped with a heating means such as an electric heater or a heat transfer medium circulating pipe, and the mold temperature can be controlled to a predetermined value using hot water or heated oil flowing through the electric heater or the heat transfer medium circulating pipe. The mold temperature is preferably about 50 to 70°C. A mold temperature lower than 50°C results in poor curing properties and reduced productivity. Conversely, a mold temperature higher than 70°C results in excessively high reactivity of the polyurethane foam composition, which reduces the flowability of the polyurethane foam composition and may result in underfilling of the polyurethane foam or a rough surface appearance.

[0034] The release agent preferably contains a solid component (wax component) having a first melting peak at 70 to 90°C and a second melting peak at 100 to 130°C. The melting peak is a value measured by a differential scanning calorimeter (DSC) for the solid component remaining after evaporating the liquid component of the release agent. When the release agent has a first melting peak at 70 to 90°C and a second melting peak at 100 to 130°C, a polyurethane foam with a good skin layer can be obtained.

[0035] The release agent having a first melting peak at 70 to 90°C and a second melting peak at 100 to 130°C preferably contains a branched-chain wax-based release agent. Examples of branched-chain wax-based release agents include those that use a branched-chain wax such as modified polyethylene wax, microcrystalline wax, or hydrocarbon-based wax as the main component, dissolved in an organic solvent, or dispersed in water using an emulsifier. The application amount of the release agent is 10 to 100 g / m. ２ is preferred.

[0036] After applying a mold release agent to the inner surface of the foam molding mold, the polyurethane foam composition is stirred and injected into the foam molding mold, and the foam molding mold is closed. The amount of polyurethane foam composition injected into the foam molding mold is determined according to the density of the resulting polyurethane foam (JIS K7222:2005). After foaming of the polyurethane foam composition, the foam molding mold is opened and the polyurethane foam is demolded.

[0037] A branched wax-based mold release agent (product name: N-915, manufactured by Chukyo Yushi Co., Ltd., melting point 48°C) was sprayed (approximately 25 g / m) onto the inner surface of a foam molding mold having an inner surface shaped like a rectangular parallelepiped. ２A polyurethane foam composition having the formulation shown in FIG. 1 and composed of the following raw materials was stirred and poured into a foam mold in an amount to achieve the density set for each Example and Comparative Example. The mold temperature was maintained at 60°C to allow foaming. The mixture was then demolded to obtain polyurethane foams for each Example and Comparative Example. For Comparative Examples 1 and 3, a foam mold with inner dimensions of 500 x 500 x 40 mm was used, while for Comparative Example 4 and Examples 1 to 3, a foam mold with inner dimensions of 500 x 500 x 30 mm was used. The amounts of each component in FIG. 1 are in "parts by weight," and "total parts" refers to the total parts by weight of the polyurethane foam composition.

[0038] Polyol A: Petroleum-derived polyether polyol, molecular weight 5000, functionality 3, hydroxyl value 34 mg KOH / g; Polyol B: Plant-derived castor oil polyol, unmodified (purified), molecular weight 945, functionality 2.7, hydroxyl value 160 mg KOH / g, product name: H-30, manufactured by Ito Oil Mills, Ltd.; Polyol C: Plant-derived castor oil polyol, modified type, molecular weight approximately 2000, functionality 3.5, product name: URIC HF2050, manufactured by Ito Oil Mills, Ltd.; Polymer polyol: Molecular weight 5000, functionality 3, hydroxyl value 28 mg KOH / g; Crosslinker: Diethanolamine; Catalyst: Amine catalyst, product name: DABCO 33LV, manufactured by Evonik Japan; Blowing agent: Water; Foam stabilizer: Silicone foam stabilizer, product name: SZ1346E, manufactured by Dow-Toray Industries, Inc. Polyisocyanate: Modified 4,4'-diphenylmethane diisocyanate, product name: Coronate 1050, manufactured by Tosoh Corporation

[0039] For the polyurethane foams of each Example and Comparative Example, moldability was judged, the biomass content was calculated, and measurements were made of density, dynamic friction coefficient, breathability, sound transmission loss, and surface hardness, and soundproofing was evaluated based on the sound transmission loss results. The symbols representing the evaluation results in Figure 1 have the following meanings: "◎" (double circle): Excellent "◯" (circle): Good "△" (triangle): Average "×" (cross): Poor

[0040] Moldability was evaluated by visually observing the demolded polyurethane foam to determine whether or not there was shrinkage. The moldability was evaluated as "good" when there was no shrinkage, "fair" when there was slight shrinkage or roughness in the skin layer, and "poor" when there was clear shrinkage or roughness in the skin layer. The plant-derived content was calculated by ([(parts of plant-derived polyol / total parts of polyurethane foam composition) x 100]. The density was measured in accordance with JIS JIS K7222:2005. Specifically, it was calculated by [sample weight / sample volume (mold internal volume)]. The dynamic friction coefficient was measured in accordance with JIS K7125. In order to facilitate sliding of the polyurethane foam and placement in a gap, the dynamic friction coefficient is, for example, preferably 5 or less, more preferably 3 or less, even more preferably 2 or less, and particularly preferably 1.5 or less. The breathability of the surface was measured in accordance with JIS K6400-7:2012A method using a sample (with skin layer) cut 10 mm from the surface of the polyurethane foam to a size of 51 x 51 x 10 mm.

[0041] The sound transmission loss was measured in a 1 / 3 octave band in the frequency range of 1000 to 6300 Hz based on JIS A1441-1:2007, and the average sound transmission loss in the frequency range of 1000 to 6300 Hz (average sound transmission loss) was calculated. The sound transmission loss was measured in a 36 m sound source reverberation chamber. ３ , the anechoic chamber is 20m ３ , the measurement area is 400 × 400 mm (0.16 m ２ ) A soundproofing material made of polyurethane foam measuring 500 mm square x 30 mm or 40 mm (with a surface skin layer) was fixed in a 50 mm wide frame around the periphery, and the gaps were further sealed with clay. Sound was introduced from a reverberation chamber on the sound source side, and measurements were taken at 25 locations (80 mm pitch) 215 mm away from the surface of the soundproofing material from a sound-receiving anechoic chamber on the non-sound source side, at 1000 Hz to 6300 Hz, and the average value was calculated.

[0042] The soundproofing evaluation was rated as "excellent" when the average sound transmission loss between 1000 and 6300 Hz was 33 dB or more, "good" when it was less than 33 dB and 30 dB or more, "fair" when it was 25 dB or more and less than 30 dB, and "poor" when it was less than 25 dB. The surface hardness was measured using an Asker C hardness tester.

[0043] Comparative Examples 1 and 2 are examples in which the polyol is composed of petroleum-derived polyol A and polymer polyol, and does not contain plant-derived polyol, and the sample thickness is different. Comparative Example 1 has a moldability of "good", a plant-derived content of 0%, and a density of 130 kg / m ３ The sample had a thickness of 40 mm, an air permeability of 4 L / min, an average sound transmission loss of 31.5 dB in the 1000-6300 Hz range, a soundproofing rating of "good", and an Asker C hardness of 2. Comparative Example 2 had a moldability rating of "good", a plant-based content of 0%, and a density of 130 kg / m ３ The sample had a thickness of 30 mm, an air permeability of 4 L / min, an average sound transmission loss of 28.8 dB in the 1000-6300 Hz range, a soundproofing rating of "fair," and an Asker C hardness of 2.

[0044] Comparative Example 3 is an example in which the polyol is composed of 90 parts by weight of plant-derived polyol B and 10 parts by weight of polymer polyol. Comparative Example 3 has a moldability of "unacceptable," a plant-derived content of 51%, and a density of 130 kg / m ３ The sample thickness was 40 mm. Comparative Example 3 had poor moldability and a good polyurethane foam could not be obtained, so that the dynamic friction coefficient, air permeability, sound transmission loss, and Asker C hardness could not be measured.

[0045] Comparative Example 4 is an example in which the polyol is composed of 33.5 parts by weight of petroleum-derived polyol A, 56.5 parts by weight of plant-derived polyol B, and 10 parts by weight of polymer polyol. Comparative Example 4 has a moldability of "good", a plant-derived content of 35%, and a density of 130 kg / m ３ The sample had a thickness of 30 mm and was not suitable for evaluation due to poor formability.

[0046] Examples 1 and 2: Examples 1 and 2 are examples in which the polyol is composed of 56.5 parts by weight of plant-derived polyol B and 43.5 parts by weight of polymer polyol, and differ in density. Example 1 has a moldability of "good", a plant-derived content of 35%, and a density of 130 kg / m ３ The sample had a thickness of 30 mm, breathability of 1.5 L / min, an average sound transmission loss of 33.5 dB in the 1000-6300 Hz range, a soundproofing rating of "excellent," and an Asker C hardness of 2. Example 1 has better soundproofing than Comparative Example 2, which has the same sample thickness and density as Example 1 and also has good moldability. Example 2 has a moldability rating of "good," a plant-based content of 35%, and a density of 120 kg / m. ３ The sample had a thickness of 30 mm, air permeability of 2 L / min, an average sound transmission loss of 32.9 dB in the 1000-6300 Hz range, a soundproofing rating of "good", and an Asker C hardness of 1. Example 2 had a lower density than Comparative Example 2 and was lighter in weight, yet had better soundproofing than Comparative Example 2.

[0047] Example 3 is an example in which the polyol is composed of 46.5 parts by weight of plant-derived polyol B, 10 parts by weight of plant-derived polyol C, and 43.5 parts by weight of polymer polyol. Example 3 has a moldability of "good", a plant-derived content of 35%, and a density of 120 kg / m ３ The sample had a thickness of 30 mm and was not suitable for evaluation due to poor formability.

[0048] Thus, according to the present disclosure, a polyurethane foam can be obtained that is lightweight yet has good soundproofing properties and contributes to reducing environmental impact. Furthermore, the polyurethane foam of the present disclosure is suitable not only for placement on wall surfaces or spaces where soundproofing is required, but also for soundproofing applications in which it is compressed and slid into voids in sound transmission paths, and then elastically restored to fill the voids after placement. It is particularly suitable as a vehicle soundproofing material, which requires both light weight and soundproofing properties. The present invention is not limited to the examples, and modifications can be made without departing from the spirit of the invention.

[0049] All references, including publications, patent applications, and patents, cited in this specification are herein incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference in its entirety.

[0050] The use of nouns and similar referents in connection with the description of the present invention (particularly in connection with the claims that follow) shall be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The words "comprises," "has," "includes," and "comprises" shall be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise noted. The recitation of numerical ranges herein is merely intended to serve as a shorthand method for individually referring to each value falling within the range, unless otherwise indicated herein, and each value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. Any example or exemplary language used herein (e.g., "etc.") is intended merely to better describe the invention and does not pose a limitation on the scope of the invention, unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0051] Preferred embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of these preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor anticipates that skilled artisans will apply such variations as appropriate, and intends to practice the invention otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, this invention includes any combination of the above-described elements in all variations thereof unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A polyurethane foam obtained from a polyurethane foam composition comprising a polyol component, a polyisocyanate, a blowing agent, and a catalyst, The polyol component includes a plant-derived polyol and a polymer polyol, the plant-derived polyol contained in the polyurethane foam composition has a plant content, expressed as % by weight, of 15% or more; A polyurethane foam having an air permeability (JIS K6400-7:2012A method) of 10 L / min or less.

2. The polyurethane foam according to claim 1 , wherein a total content of the plant-derived polyol and the polymer polyol in the polyol component is 90% by weight or more.

3. The polyurethane foam according to claim 1 or 2, having an average sound transmission loss (JIS A1441-1:2007) of 30 dB or more at a frequency of 1000 to 6300 Hz.

4. The polyurethane foam according to claim 1 or 2, having a density of 120 kg / m 3 or more and less than 170 kg / m 3 .

5. 3. The polyurethane foam according to claim 1, having a surface hardness of 30 or less on the Asker C scale.

6. A polyurethane foam as described in claim 1 or 2, having a wax component on its surface having a first melting peak of 70 to 90°C and a second melting peak of 100 to 130°C.

7. A polyurethane foam as described in claim 1 or 2, having a dynamic friction coefficient of 5 or less.

8. A soundproofing material comprising the polyurethane foam described in claim 1 or 2.

9. A soundproofing material for vehicles comprising the polyurethane foam described in claim 1 or 2.

10. A polyurethane foam as described in claim 1, having an air permeability (JIS K6400-7:2012A method) of 6 L / min or less.

11. A polyurethane foam as described in claim 2, wherein the polyol component consists only of the plant-derived polyol and the polymer polyol.

12. A polyurethane foam as described in claim 3, having an average sound transmission loss (JIS A1441-1:2007) of 32 dB or more at frequencies of 1000 to 6300 Hz.

13. A polyurethane foam as described in claim 12, having an average sound transmission loss (JIS A1441-1:2007) of 33 dB or more at frequencies of 1000 to 6300 Hz.

14. The polyurethane foam according to claim 4, having a density of 120 kg / m 3 or more and 130 kg / m 3 or less.