Comfortable cotton polyurethane foam material

Abstract

The present application relates to a polyurethane foam comprising A) a highly active polyether polyol having a low unsaturation of no more than 0.04 mol / kg and having a weight average molecular weight Mw of from 6500 to 7800; b) a polyisocyanate; and C) a blowing agent in an amount of 2.60 to 3.40% by weight, preferably 2.70 to 3.30% by weight, particularly 2.80 to 3.20% by weight, based on 100 parts by weight of the highly active polyether polyol; wherein the NCO index of the polyisocyanate is in the range of 0.86 to 0.98, preferably in the range of 0.89 to 0.95. In addition, the invention also relates to a preparation method of the polyurethane foam material and a product prepared by the preparation method.

Description

Field of the Invention

[0001] The present invention relates to a foam material for seats and interior trims of vehicles, in particular a foam material based on polyurethane. In addition, the present invention also relates to a method for preparing the foam material and a product containing the foam material. Background of the Invention

[0003] In the manufacture of transportation vehicles such as automobiles, the comfort of seats and interior parts is very important. It is one of the important considerations when consumers choose and experience products.

[0004] Polyurethane materials have good elasticity, wear resistance and chemical resistance. Different hardness and performance can be controlled by adjusting the raw material ratio and reaction conditions of polyurethane materials. Foam material is a material with a closed-cell or open-cell structure, which has good functional properties such as light weight, shock absorption, sound insulation, and heat insulation. Therefore, in the field of automobile manufacturing, polyurethane materials, especially polyurethane foam materials, are widely used in the manufacture of seat filling materials and interior parts.

[0005] There are a wide variety of polyurethane soft foam products on the market, including high-rebound polyurethane foam and slow-rebound polyurethane foam.

[0006] Slow-rebound polyurethane foam products will not rebound immediately when deformed by external pressure, but will be delayed for several seconds and slowly restored. Therefore, the foam has significant viscoelastic properties, embodies very soft material properties, and has strong impact energy absorption capacity. However, this type of foam material has defects such as slow and poor rebound, sensitive to temperature, hardness change is greatly affected by temperature, poor foam hysteresis loss, and large compression deformation.

[0007] High-resilience polyurethane foam has the advantages of super strong resilience and air permeability, low hysteresis loss, high compression load ratio, and good resistance to heat aging, wet aging and dynamic fatigue. However, this foam material has defects such as too fast rebound (resulting in poor shock absorption), lack of stability and absorption capacity, poor sound insulation, poor air permeability and insufficient softness.

[0008] Therefore, in the current field of transportation manufacturing, especially in the field of automobile manufacturing, traditional polyurethane foam filling materials are difficult to meet the comfort requirements during long-term driving or riding, so there is an urgent need to develop new polyurethane foam materials (especially for seats and interior trims) to provide a better comfort experience. Summary of the invention

[0009] In view of this, the main task of the present invention is to provide an improved polyurethane foam material, which can be particularly used for seats and interior parts in vehicles such as automobiles to improve their comfort. In particular, these seats and interior parts made of the polyurethane foam material of the present invention should have better cell structure control, rebound rate, hysteresis loss, softness, compression deformation, sound absorption, low temperature resistance and shock absorption performance, so as to provide better comfort to enhance the experience of drivers and passengers.

[0010] The polyurethane foam material according to the present invention combines the advantages of slow-rebound foam and high-rebound foam, while avoiding or weakening the defects of the two as much as possible. Specifically, the polyurethane foam material of the present invention solves the problem of insufficient softness of high-rebound foam on the one hand, and can have good low hysteresis characteristics like high-rebound foam in a very soft state, thereby improving more uniform pressure distribution; on the other hand, it solves the problems of low-temperature resistance and insufficient support of slow-rebound foam, and has softer and better body feel and shock-absorbing performance.

[0011] The polyurethane foam material according to the present invention can advantageously have at least three of the following advantageous structures and performance indicators, and preferably has these advantageous structures and performance indicators simultaneously:

[0012] Rebound rate: can be between 25-40%, such as 28-39% or 30%-39%. This parameter can be determined by method B of test standard GB / T 6670;

[0013] Hysteresis loss: can be between 18% and 25%, such as 19-24% and 21%. This parameter can be determined by standard GB / T 18942.1;

[0014] Softness: The top hardness of the polyurethane foam material of the present invention is between 1.3-2.4 kPa, such as 1.4, 1.6, 2.2 or 2.3 kPa. This parameter can be determined by standard GB / T 18942.1;

[0015] Low temperature resistance: the polyurethane foam material of the present invention does not change significantly in its indentation hardness under low temperature conditions, such as as low as -40°C compared with that at room temperature (23°C), such as a change in indentation hardness of no more than 5.02N, such as 5.01N or 5.0N; and / or

[0016] Shock absorption performance: The conductivity of the polyurethane foam material of the present invention can reach about 2.68, such as 2.5-2.85, and the resonance frequency is about 3.25 Hz, such as 3.20 Hz to 3.35 Hz, which meets the test standard of JASO 407.

[0017] In a preferred embodiment, the polyurethane foam material according to the present invention can advantageously have the above-mentioned rebound rate, hysteresis loss and softness indexes at the same time.

[0018] In a more preferred embodiment, the polyurethane foam material according to the present invention may also have the following advantageous properties:

[0019] Noise reduction and sound absorption: The sound absorption coefficient of the polyurethane foam material of the present invention can reach greater than 0.8 in the range of 2000-3150Hz, which can be measured by the transfer function method in the test standard GB / T 18696.2-2002 "Measurement of sound absorption coefficient and acoustic impedance in impedance tubes";

[0020] and / or

[0021] Cell structure: The number of cells in the foam is about 60 kg / m 3 Approximately 2000-2600 pores / square inch can be achieved, which can be determined using an optical microscope.

[0022] In the prior art, it is quite difficult to balance and take into account the advantages of slow-rebound foam and high-rebound foam, especially to achieve simultaneous improvement of at least three (preferably all) of the above-mentioned rebound rate, hysteresis loss, softness, low-temperature resistance and shock absorption. However, the inventors of the present application unexpectedly achieved this technical effect by adjusting the composition of the polyurethane foam material. At the same time, the mechanical properties of the obtained polyurethane foam material can also be maintained or improved, especially in terms of elongation at break, tensile strength and tear strength.

[0023] Therefore, a first aspect of the present invention relates to a polyurethane foam material comprising:

[0024] A) a highly active polyether polyol having a low unsaturation of not more than 0.04 mol / kg and a weight average molecular weight Mw of 6500-7800;

[0025] B) polyisocyanates; and

[0026] C) a blowing agent, wherein the content of the blowing agent is 2.60-3.40 wt % based on 100 parts by weight of the highly active polyether polyol;

[0027] The NCO index of the polyisocyanate is in the range of 0.86-0.98, preferably 0.89-0.95.

[0028] A second aspect of the present invention relates to a process for preparing the polyurethane foam according to the present invention.

[0029] In the context of this application, polyurethane foam materials (or polyurethane foam compositions) are based on polyurethane polymers. Polyurethanes, also known as polyurethanes, are usually prepared by reacting one or more alcohol components, such as polyols, with one or more isocyanate components, such as polyisocyanates. Therefore, the polyurethane foam materials according to the present invention usually include at least one polyol and at least one polyisocyanate, as well as a blowing agent. The blowing agent can induce gas in the material, thereby generating pores and forming a foam structure.

[0030] In the polyurethane foam material of the present invention, the polymer matrix containing the porous foam structure is mainly composed of polyurethane. For example, in one embodiment, more than 90% by weight, preferably more than 95% by weight, more than 98% by weight or 99% by weight or all of the polymer matrix can be composed of polyurethane, especially polyurethane formed by polyether polyol and polyisocyanate according to the present invention. In one embodiment, the polyurethane matrix formed by the reaction of alcohol and isocyanate, especially the polyurethane according to the present invention, can account for more than 75% by weight of the total weight of the entire foam material, preferably 80% by weight, more preferably 85% by weight or more than 90% by weight, and the remainder can include possible various functional additives or possible fillers, etc.

[0031] In a preferred embodiment, the blowing agent may be water, which can react with polyisocyanate to generate carbon dioxide gas. However, other blowing agents, including those commonly used physical and chemical blowing agents, may also be used alone or in combination with water. In addition, the polyurethane foam material of the present invention may also contain a crosslinking agent, a chain extender, a catalyst, a cell opener, a surfactant and other additives.

[0032] Preferably, from the perspective of environmental friendliness and being more conducive to foaming and density control, the blowing agent used in the polyurethane foam composition according to the present invention mainly comprises water, which means that the main amount of the blowing agent component, such as 90wt% or more, preferably 95wt%, more preferably 98wt% or 99wt% or more or most preferably 100wt%, is water, based on the total weight of the blowing agent component.

[0033] In the polyurethane foam composition according to the present invention, the content of the blowing agent is 2.60-3.40 wt%, preferably 2.70-3.30 wt%, and particularly 2.80-3.20 wt%, based on 100 wt% of the highly active polyether polyol. The applicant has found that controlling the content of the blowing agent within such a narrow specific range is particularly advantageous for obtaining the desired top hardness, rebound rate and hysteresis loss values.

[0034] A variety of different polyisocyanates can be used to prepare the polyurethane foams of the present invention. Suitable polyisocyanates include organic polyisocyanates such as aromatic polyisocyanates, aliphatic, alicyclic or araliphatic polyisocyanates. Particularly preferred are those polyisocyanates that are liquid at 25°C. Examples of suitable polyisocyanates include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-xylylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), polymethylene polyphenylene polyisocyanate (such as polymeric MDI); and 1,5-naphthalene diisocyanate. Mixtures of these polyisocyanates may also be used.

[0035] As the polyisocyanate in the polyurethane foam material of the present invention, aromatic polyisocyanates such as MDI, TDI or a mixture of the two are preferred. 2,4-Toluene diisocyanate, 2,6-Toluene diisocyanate and mixtures thereof are generally referred to as "TDI". Diphenylmethane-4,4'-diisocyanate (4,4'-diphenylmethane diisocyanate), diphenylmethane-2,2'-diisocyanate (2,2'-diphenylmethane diisocyanate) and diphenylmethane-2,4'-diisocyanate (2,4'-diphenylmethane diisocyanate) and mixtures thereof are generally referred to as "MDI" herein. In one embodiment, MDI or a mixture of polymeric MDI and TDI is used as the polyisocyanate. Preferably, in this embodiment, the weight ratio of TDI:MDI (including polymeric MDI) may be in the range of 90 / 10-60 / 40; or in this embodiment, the weight content of polymeric MDI may be greater than or equal to 20% and the weight content of TDI may be less than or equal to 80%. Suitable polyisocyanates are commercially available, for example, from BASF or Huntsman, etc., or can be synthesized by a person skilled in the art according to a preparation method known in the art.

[0036] It has been found that aromatic polyisocyanates are more preferred than aliphatic, alicyclic or aromatic aliphatic polyisocyanates. The use of aromatic polyisocyanates can be more conducive to the improvement and balance of rebound rate, hysteresis loss, top hardness and shock absorption, and can also improve the mechanical properties of polyurethane foam materials such as elastic modulus, wear resistance, chemical resistance and flame retardancy.

[0037] Optionally, as polyisocyanates, some isocyanate-terminated prepolymers can also be used. Such prepolymers are generally prepared by reacting a molar excess of polymeric or pure polyisocyanates with one or more polyols. Such polyols include, for example, aminated polyols, imine- or enamine-modified polyols, polyether polyols, polyester polyols or polyamines. Pseudo-prepolymers can also be used, which are mixtures of isocyanate-terminated prepolymers and one or more monomeric di- or polyisocyanates.

[0038] Polyisocyanates can be characterized by the "functionality" of the average number of isocyanate groups per molecule. The number average isocyanate functionality of the polyisocyanate is preferably at least 1.8 to about 5.0. Particularly preferred polyisocyanates include polyisocyanates having a functionality of about 2.0 to about 4.0, more preferably about 2.3 to about 2.9, such as polyisocyanates based on MDI or TDI.

[0039] In the field of polyurethane, a variety of polyols are usually used to prepare polyurethane foam materials. Exemplary polyols include polyhydroxyalkane polyols, polyoxyalkylene polyols (or polyether polyols), alkylene oxide adducts of polyhydroxyalkanes, alkylene oxide adducts of non-reducing sugars and sugar derivatives, alkylene oxide adducts of phosphorous acid and polyphosphorous acid, and alkylene oxide adducts of polyphenols and polyols from natural oils such as castor oil.

[0040] However, the inventors of the present invention have found that the use of a high-activity polyether polyol as the main polyol in the polyurethane foam material according to the present invention is very important for achieving the excellent effects of the present invention as described above. Such a high-activity polyether polyol should have a low unsaturation of no more than 0.04 mol / kg, preferably less than 0.038, such as 0.035, such as 0.032 mol / kg, and a weight average molecular weight Mw of 6500-7800 g / mol, more preferably 6900-7700 g / mol, such as 7000-7600 g / mol. More preferably, the high-activity polyether polyol has an average functionality greater than 2, preferably greater than 2.5, such as 3, and / or a hydroxyl value of 19.0-28.0, preferably 21.0-24.0 mg KOH / g. In one embodiment, such a high-activity polyether polyol advantageously has a viscosity at 25°C of about 1400-1700 cps.

[0041] In the context of this application, the molecular weight refers to the weight average molecular weight Mw, which is measured by gel permeation chromatography. In this test method, the polymer substance is fractionated in solution according to the hydrodynamic volume, wherein the polymer solution is passed through a separation column composed of a porous support, and macromolecules with different molecular volumes are located in different positions and have different residence times inside the column, thereby being separated. Those skilled in the art are familiar with how to operate gel permeation chromatography and what suitable equipment to use for measurement.

[0042] In the context of this application, viscosity is measured using a rotational viscometer. The rotational viscometer is a commonly used viscosity measurement method that measures the viscosity of a liquid using a rotational viscometer. A rotational viscometer is a precision instrument that consists of a rotating cylindrical rotor and a fixed cylindrical container. During measurement, the liquid to be measured is injected into the container, and then the rotor is placed in the container. The rotational viscometer is started, and the rotor begins to rotate. The liquid generates shear force as the rotor rotates, thereby generating flow. By measuring the resistance to the rotation of the rotor, the viscosity of the liquid can be calculated.

[0043] Suitable highly active polyether polyols for use in the present invention include, for example, polyether diols and polyether triols or mixtures thereof, with polyether triols being particularly preferred.

[0044] Particularly suitable polyether polyols are the polymerization products of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetanes, tetrahydrofuran or mixtures thereof, optionally with the aid of starter molecules having two or more active hydrogen atoms, for example water, ammonia or compounds having a plurality of OH or NH groups, for example 1,2-ethanediol, 1,2- and 1,3-propylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, 1,3- and 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, aniline and mixtures of the aforementioned compounds.

[0045] Ethylene oxide-terminated polyoxypropylene polyols are also suitable. These are in particular polyoxypropylene polyoxyethylene polyols, which can be obtained, for example, by further alkoxylating pure polyoxypropylene polyols, in particular polyoxypropylene diols and triols, with ethylene oxide after the polypropoxylation reaction has ended, thereby providing them with primary hydroxyl groups. Preferred in this case are polyoxypropylene polyoxyethylene diols and polyoxypropylene polyoxyethylene triols.

[0046] In a preferred embodiment, the polyether diol and polyether triol are selected from polyoxyethylene diol or triol, polyoxypropylene diol or triol, and polyoxypropylene polyoxyethylene diol or triol; in particular, polyoxyethylene triol and polyoxypropylene triol.

[0047] In a preferred embodiment of the polyurethane foam material of the present invention, the polyol in the polyurethane foam composition is essentially composed of the high-reactive polyether polyol, which means that based on the total weight of all polyols in the composition, the polyol component includes at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, such as at least 99% by weight, and most preferably 100% by weight of the high-reactive polyether polyol, based on the total weight of all polyols.

[0048] The compositions of the present invention may also optionally contain small amounts of other simple polyols (e.g., 1,2-ethanediol, 1,2- and 1,3-propylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, isomeric dipropylene glycol and tripropylene glycol, isomeric butanediols, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimeric fatty alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol). , pentaerythritol, sugar alcohols such as xylitol, sorbitol or mannitol, sugars such as sucrose, other higher alcohols, low molecular weight alkoxylation products of the diols and polyols, polyester polyols, and mixtures of the above alcohols), or polyhydroxyalkane polyols as described above, other polyether polyols, alkylene oxide adducts of polyhydroxyalkanes, alkylene oxide adducts of non-reducing sugars and sugar derivatives, alkylene oxide adducts of phosphorous acid and polyphosphorous acid, alkylene oxide adducts of polyphenols and polyols from natural oils such as castor oil. In an advantageous embodiment, the polyurethane foam composition according to the invention may contain less than 5% by weight, more preferably less than 2% by weight, such as less than 1% by weight, less than 0.5% by weight or less than 0.1% by weight or 0% by weight of other polyether polyols different from the highly active polyether polyols as polyol components.

[0049] All these polyols, in particular polyether polyols such as these, are commercially available or can be prepared by a person skilled in the art according to methods known in the art.

[0050] The polyurethane foam material according to the present invention can be formulated in the form of two components / parts, three components / parts or more components / parts, that is, by mixing a "second component" containing at least one polyisocyanate with a "first component" containing a polyol and optional other components. In the chemical field, the so-called "two components / parts" or "multi-component / parts" formulation is a composition formulation form familiar to technicians, in which the components of one or more compositions are prepared separately and placed in separate packages or containers (i.e., components or parts) to facilitate processing, operation and avoid premature mutual reactions. These components or parts containing one or more components are opened when needed during operation and processing to mix the components with each other. The technician knows that when preparing a two-component or multi-component formulation, the components that do not react with each other under operating or storage conditions should be placed in the same package or container.

[0051] In a preferred formulation, the polyol of the first component / part comprises a high-reactive polyether polyol, preferably in an amount of at least 70 wt %, preferably at least 80 wt %, more preferably at least 85 wt %, 90 wt % or at least 95 wt % or at least 98 wt % or 100 wt % based on the total amount of the first component / part.

[0052] In an advantageous embodiment, the content of the high-activity polyether polyol may be, for example, in the range of 55-92 wt %, preferably 60-87 wt % or 65-85 wt %, based on the total weight of the foam composition.

[0053] In addition, the polyurethane foam composition according to the present invention may also contain some other types of ingredients for adjusting the properties of the polyurethane foam, such as crosslinking agents, chain extenders, cell openers, surfactants, delayed foaming catalysts, etc. In the form of two components / parts, these other types of ingredients may, for example, be contained in the first component / part or the second component / part. In the form of more components / parts, these other types of ingredients may also constitute the third, fourth or more components / parts alone.

[0054] The total amount of crosslinking agent and / or chain extender should be sufficient to cause crosslinking and chain growth in the polyurethane product. The total amount of crosslinking agent and chain extender can generally be about 0.2 to about 2.5 weight %, such as 0.7-2.0 weight %, based on the total weight of the composition. Preferred crosslinking agents and chain extenders include amine compounds, such as triethanolamine or diethanolamine.

[0055] The polyurethane foam composition according to the present invention may also contain one or more catalysts for the reaction of alcohols with isocyanates (especially in the first component), which are preferably contained in an amount of about 0.1 to about 2.5% by weight, for example 0.15-1.5% by weight, 0.20 to about 1.0% by weight or 0.25-0.85% by weight, based on the total weight of the composition.

[0056] Advantageously, the polyurethane foam composition according to the present invention may contain a combination of two catalysts to better regulate the formation of polyurethane and control the formation of gas, such as an amine catalyst and a tin catalyst. Suitable amine catalysts include, for example, bis(dimethylaminoethyl) ether, triethylenediamine, dimethylaminopropylaminodiisopropanol, etc. Suitable tin catalysts include organic tin compounds such as stannous octoate or other tin catalysts such as dibutyltin catalysts.

[0057] In addition, the polyurethane foam composition according to the present invention may also include one or more cell openers (especially included in the first component). The foam can generally be characterized as "open cell" or "closed cell", depending on whether the mouth of adjacent cells is open (i.e., the cells are interconnected) or closed. In certain exemplary embodiments, the polyurethane foam according to the present invention may have at least about 80% open cells, such as at least about 90% open cells, and even at least about 95% of the cells are open. The cell opener can promote the formation of open cells. Exemplary cell openers include silicon-based defoamers, waxes, fine particle solids, liquid perfluorocarbons, paraffin oils, and long-chain fatty acids. If a cell opener is used, it is preferably present in an amount sufficient to provide the desired percentage of open cells. For example, the cell opener can be present in an amount of 0.5-5% by weight, such as 1.0-2.5% by weight, based on the total weight of the composition.

[0058] In order to promote cell formation and stabilization, the polyurethane foam composition may also include one or more surfactants (especially included in the first component). Examples of surfactants include nonionic surfactants and wetting agents. Such surfactants may be silicone oils. The total amount of surfactant may be, for example, about 0.5-6% by weight based on the total weight of the composition, for example, in an amount of about 1.0 to about 3% by weight.

[0059] It is important in the present invention that the NCO index of the polyisocyanate be controlled within a narrow range of 0.86-0.98, preferably 0.89-0.96, for example 0.90, 0.92 or 0.95.

[0060] The NCO index of isocyanate refers to the ratio of the isocyanate equivalent of isocyanate to the hydroxyl equivalent of alcohol in the polyurethane reaction. In particular, in the present invention, the NCO index of isocyanate can be calculated according to the following formula:

[0061] NCO index = (number of isocyanate groups (-NCO) equivalents ÷ number of hydroxyl groups equivalents)

[0062] In this formula, the isocyanate equivalent number is based on all isocyanate-containing compounds in the system, including isocyanate groups in the form of functional groups on monomers containing free isocyanate groups or polymeric or oligomeric polyisocyanates. The hydroxyl equivalent is based on all alcohols or polyol compounds used in the system (excluding hydroxyls that may be contained in water or other additives), such as polyether polyols. In a preferred embodiment, the alcohols or polyols in the polyurethane reaction system of the present invention are all the highly active polyether polyols.

[0063] It is well known to those skilled in the art that the equivalent number of a functional group in a given compound molecule can be determined by the following formula: equivalent number = (weight of the compound molecule / g) ÷ (equivalent weight of the compound molecule g / eq). Furthermore, those skilled in the art can also calculate the equivalent weight of a specific functional group in a given compound according to the following formula: equivalent weight = (molecular weight of the specified functional group g / mol) ÷ (the number of functional groups contained in the molecule). Therefore, in the present invention, for a selected isocyanate such as an aromatic polyisocyanate and an alcohol or polyol compound, the polyisocyanate index in the system can be easily determined.

[0064] Another aspect of the present invention relates to a method for preparing a polyurethane foam material according to the present invention. The present invention can provide a flexible polyurethane foam which has a wide processing window and can be produced as a continuous foaming or a molded foam.

[0065] The preparation method comprises mixing the components of the polyurethane foam material according to the present invention, and then foaming the mixture, thereby obtaining the polyurethane foam material having the advantages as described above. The mixing operation can be performed manually or automatically in any suitable mixing device and container. The foaming of the mixture can adopt any suitable foaming process, such as molded foaming (including cutting and vertical / horizontal double hardness foaming, with less edge skin loss), box foaming (which is an intermittent fast foaming process, in which the raw materials are mixed evenly and then quickly injected into the mold for foaming molding) and continuous foaming (large output, suitable for large-scale production, improving production efficiency, and reducing production costs), etc.

[0066] In an advantageous embodiment, the polyurethane foam material is in the form of a multi-component material comprising at least two components, which includes a "first component" comprising a polyol and a "second component" comprising at least one polyisocyanate. The method for preparing the polyurethane foam material in the form of a multi-component composition comprises the following steps:

[0067] 1) providing the various components of the first component to obtain a first component containing a highly active polyether polyol,

[0068] 2) providing the components of the second component to obtain a second component comprising a polyisocyanate,

[0069] 3) optionally providing further components comprising additives,

[0070] 4) mixing the separately prepared first and second components and optionally further components with one another, and

[0071] 5) The obtained mixture is foamed.

[0072] When formulated into a two-component or more-component multi-component form, ensure that the first component / part contains at least the highly active polyether polyol and the second component / part contains at least the polyisocyanate, and the remaining ingredients, such as additive ingredients such as crosslinking agents, chain extenders, cell openers, surfactants, delayed foaming catalysts, etc., can be selectively included in the first component / part or the second component / part, provided that the individual ingredients in each component do not react with each other prematurely. In the form of more components / parts, these other types of ingredients can also constitute the third, fourth or more components / parts separately.

[0073] In a specific embodiment, the various components of the first component can be mixed in a batching container according to the formula to obtain a mixture of the first component. A stirrer is preferably used during mixing, for example, mixing can be performed at a speed of 50 rpm. The mixing time can be set as needed, for example, advantageously 30 min-45 min. Optionally, after standing for a period of time such as 10 min to 15 min, the first component is fed into a material tank of a foaming machine and then a second component or more components are provided. For example, the second component containing polyisocyanate prepared separately and the third and fourth components containing other components can then be successively fed into another material tank of the foaming machine, and after mixing, they are fed into a foaming process such as pouring into a mold for reaction and foaming.

[0074] Here, the temperature of the raw material can be controlled at 20° C. to 30° C. In a specific embodiment, the mold temperature can be set to 55-70° C., and the reaction time is 150s to 200s. Demolding is performed after aging.

[0075] The demoulded product can be further subjected to vacuum foaming treatment. After vacuuming, it can be cut into required sizes to obtain the required polyurethane foam material.

[0076] It has been found in the present invention that in a more preferred embodiment, the foaming of the polyurethane foam material is controlled so that it has a density of 45-65 kg / m 3 Density, for example 49-62 kg / m 3The density of the foam is very advantageous for achieving the effect of the present invention by simple means. This can be achieved by selecting suitable foaming conditions and processes, such as selecting suitable molded foaming, box-type foaming or continuous foaming, and / or by controlling the temperature and duration of foaming.

[0077] The operation of controlling the density itself is easy for those skilled in the art. In addition to selecting different foaming methods as mentioned above, the material can also be foamed to the required density level by, for example, selecting a suitable mold size and the corresponding amount of polyurethane feed.

[0078] The polyurethane foam material according to the present invention has a wide range of applications, for example, it can be used as a cushioning material in furniture, household appliances, office supplies, automobiles, trains, ships or aerospace fields, such as a cushioning material in office chairs, sofas, mattresses, carpets, and seats in vehicles. Example

[0079] The present invention is further explained below by way of examples, but the present invention should obviously not be limited to these specific examples.

[0080] Ingredients list

[0081] The following raw materials were used in the examples

[0082] Table 1

[0083]

[0084]

[0085] Preparation of polyurethane foam materials

[0086] According to the formula shown in Table 2, add all the ingredients except polyisocyanate into the batching cylinder, mix and stir for 30min-45min with a stirrer (stirring speed 50rpm), let stand for 10min-15min, and then pump into the material tank of the foaming machine as the first component containing polyol. The second component containing polyisocyanate is pumped into the isocyanate material tank of the foaming machine, and the raw material temperature is controlled at 20℃~30℃. Mix in proportion through the mixing head of the foaming machine and pour into the mold for foaming. The mold temperature is 68℃, the reaction time is 150s~200s, and demolding is performed after aging. Finally, the demolded product is subjected to vacuum foaming treatment, and after vacuum treatment, it is cut into the required size.

[0087] The obtained polyurethane foam material was subjected to performance testing using the automotive industry standards shown in the table. The test results are listed in Table 2.

[0088] The following table lists the tested properties and the measurement standards or measurement conditions of the properties. The following are particularly required:

[0089] Low temperature resistance: Low temperature resistance is characterized by the change in indentation hardness at low temperature. This value is defined in this application as the change in the extrusion force required for the polyurethane foam material to be indented to the same depth at -40°C compared to room temperature (23°C). First, cut the epidermis of the sample and then cut it into 3 pieces of 100mm×100mm×50mm in size. Use the Lixinbao FGJ-20 hardness tester to measure the extrusion force applied to indent it to a fixed depth d at room temperature 23°C. Then put the sample into a constant temperature and humidity test chamber (its temperature accuracy can be ±1°C, relative humidity (50±5)%). After the temperature reaches -40°C for 6 hours, use the Lixinbao FGJ-20 hardness tester to measure the pressure value applied to indent the sample to the same depth d at this temperature. Take multiple pressure averages, and then calculate the pressure change (unit N) at the same indentation depth at -40°C compared to room temperature.

[0090] Cell structure: First, select three locations equidistant along the length of the product and measure and record the number of cells within one square inch at the three locations. Then, take the average of the three sets of data as the test result. The following evaluation criteria are used:

[0091] "Coarse": the number of cells is 1000-1499 / square inch,

[0092] "Slightly coarse": the number of cells is 1500-1999 / square inch,

[0093] “Fine”: The number of cells is 2000-2600 / square inch.

[0094] "Closed cell" is determined by air permeability, the test standard is ISO 7231, using a foam air permeability tester, ≤0.3 (dm 3 / s) was considered as closed cells, and ≥0.4 (dm3 / s) was considered as open cells. The number of cells was determined by using an optical microscope.

[0095] In the following table, Ex1 to Ex12 respectively compare the performance of different polyols when using different aromatic polyisocyanates and different NCO indices, showing that when the low-unsaturation high-activity polyether polyol according to the present invention is used, a polyurethane foam material with resilience, hysteresis loss, softness, low temperature resistance and shock absorption all within the required range can be obtained.

[0096] Ex13-Ex17 show the effect of different blowing agent contents on the performance of polyurethane foam materials.

[0097] Ex18-Ex23 show the effect of different NCO indexes on the properties of the polyurethane foam of the present invention.

[0098] In Ex24-Ex27, the density of the polyurethane foam material after foaming is controlled by different foaming processes and conditions, and it is controlled at different density levels. As shown in the table, when the density is controlled at 45-65kg / m 3 level, a polyurethane foam material with favorable rebound rate, hysteresis loss, softness, low temperature resistance and shock absorption can be obtained.

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

Claims

1. A polyurethane foam material comprising A) a highly active polyether polyol having a low unsaturation of not more than 0.04 mol / kg, preferably less than 0.035, such as 0.032 mol / kg, and a weight average molecular weight Mw of 6500-7800 g / mol, more preferably 6900-7700 g / mol; B) polyisocyanates; and C) a blowing agent, the content of which is 2.60-3.40 wt. %, preferably 2.70-3.30 wt. %, in particular 2.80-3.20 wt. %, based on 100 parts by weight of the highly active polyether polyol; The NCO index of the polyisocyanate is in the range of 0.86-0.98, preferably 0.89-0.

95.

2. The polyurethane foam material according to claim 1, characterized in that The blowing agent is water.

3. The polyurethane foam material according to any one of the preceding claims, characterized in that The high-activity polyether polyol has an average functionality greater than 2, preferably greater than 2.5, such as 3, and / or a hydroxyl value of 19.0-28.0, preferably 21.0-24.0 mg KOH / g.

4. The polyurethane foam material according to any one of the preceding claims, characterized in that The highly active polyether polyols include polyether diols and polyether triols or mixtures thereof, and polyether triols are particularly preferred.

5. The polyurethane foam material according to any one of the preceding claims, characterized in that The polyisocyanate is an aromatic polyisocyanate, preferably selected from 1,4-xylylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), polymethylene polyphenylene polyisocyanate (such as polymeric MDI), 1,5-naphthalene diisocyanate; in particular MDI, polymeric MDI, TDI or mixtures thereof.

6. The polyurethane foam material according to any one of the preceding claims, characterized in that The polyisocyanate is MDI or a mixture of polymeric MDI and TDI.

7. The polyurethane foam material according to any one of the preceding claims, characterized in that The polyurethane foam material is in the form of a multi-component material comprising at least two components, which includes a "first component" comprising a polyol and a "second component" comprising at least one polyisocyanate.

8. The polyurethane foam material according to any one of the preceding claims, characterized in that The polyurethane foam material has a rebound rate ranging between 25-40% as measured by method B of test standard GB / T 6670, a hysteresis loss ranging between 18%-25% as measured by standard GB / T 18942.1, and a softness with a top hardness between 1.3-2.4 kPa as measured by standard GB / T 18942.

1.

9. The polyurethane foam material according to any one of the preceding claims, characterized in that The polyurethane foam material has an indentation hardness change value of not more than 5.02N at a temperature as low as -40°C compared with that at normal temperature (23°C).

10. The polyurethane foam material according to any one of the preceding claims, characterized in that The obtained polyurethane foam material has a hardness of 45-65kg / m 3 Density, for example 49-62 kg / m 3 density.

11. A method for preparing a polyurethane foam material according to any one of the preceding claims, comprising mixing the individual components of the polyurethane foam material with one another and then foaming the mixture to obtain the polyurethane foam material.

12. The method according to claim 11, wherein the foaming of the mixture is carried out by a foaming process selected from the following: molded foaming, box foaming and continuous foaming.

13. The method according to claim 11 or 12, wherein the polyurethane foam material is a polyurethane foam material in the form of a multi-component composition, comprising the steps of: 1) providing the various components of the first component to obtain a first component containing a highly active polyether polyol, 2) providing the components of the second component to obtain a second component comprising a polyisocyanate, 3) optionally providing further components comprising additives, 4) mixing the separately prepared first and second components and optionally further components with one another, and 5) The obtained mixture is foamed.

14. A foam product obtained from the polyurethane foam material according to any one of claims 1 to 8 or prepared by the process according to claims 9 to 11.

15. The foam product according to claim 14, wherein the product is a cushioning material in furniture, household appliances, office supplies, automobiles, trains, ships or aerospace fields, such as a cushioning material in office chairs, sofas, mattresses, carpets, and seats in vehicles.

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