Composition for the production of polyurethane foam and a molded object produced therefrom

Abstract

Composition for the production of a polyurethane foam, comprising: a quantity of 100 parts by weight of a polyol composition (A), an isocyanate composition (B) wherein the isocyanate composition (B) is obtainable by steps comprising polymerizing 1) an amount of approximately 1 to 5 parts by weight of polyether polyol (b2) in relation to 100 parts by weight of the polyol composition (A) and 2) an isocyanate composition (b1) comprising i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl isocyanate (M-MDI) in relation to 100 parts by weight of the polyol composition (A) and ii) an amount of approximately 8 to 21 parts by weight of polymethylene diphenyl isocyanate (P-MDI) in relation to 100 parts by weight of the polyol composition (A), wherein the polyether polyol (b2) is obtainable by steps including the polymerization of propylene oxide (PO) and ethylene oxide (EO) and has a weight-averaged molecular weight of approximately 3,000 to 8,000 g / mol and an OH value of 20 to 60 mg KOH / g, the polyol composition (A) comprises: an amount of approximately 85 to 95 wt% polyether polyol (a1); and an amount of approximately 5 to 15 wt% of a grafted polymer polyol (a2') in which one or more monomers consisting of the group comprising acrylonitrile and Styrene are selected and grafted onto a polyether polyol with a weight-averaged molecular weight of 5,000 to 8,000 g / mol and an OH value of 20 to 35 mg KOH / g, with respect to the total weight of the polyol composition (A), wherein the polyether polyol (a1) is obtainable by steps including the polymerization of propylene oxide (PO) and ethylene oxide (EO) and has a weight-averaged molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g.

Description

TECHNICAL AREA

[0001] The present invention relates to a polyurethane composition for manufacturing a vehicle seat cushion with improved static and dynamic comfort. The composition comprises a polyol composition A, in which polyether polyol a1 and polymer polyol a2 are mixed in a predetermined amount, and an isocyanate composition B, obtainable by steps that include polymerizing polyether polyol in an isocyanate mixture of methylene diphenyl diisocyanate (monomeric or M-MDI) and polymethylene diphenyl diisocyanate (P-MDI) without the use of toluene diisocyanate. The composition may optionally include additives. BACKGROUND

[0002] In the prior art, the hardness and other mechanical properties of a vehicle seat cushion were considered significant property factors relating to characteristics such as the seat's shape and malleability, as well as its appearance. Furthermore, to reduce vehicle manufacturing costs, a polyurethane seat cushion was produced using a raw material that is inexpensive, low-density, and malleable, thereby increasing productivity but comparatively reducing driving comfort.

[0003] The main factors influencing ride comfort can be measured as hysteresis loss, which indicates the supportive feel of the seat cushion when the driver is seated, and vibration characteristics, which indicate ride comfort while driving. Seat cushion ride comfort can be significantly improved by minimizing hysteresis loss and enhancing vibration characteristics.

[0004] Recently, developments in the automotive industry have diversified customer requirements for vehicle performance, and the importance of seat cushions for driving comfort has increased significantly. In response to these customer needs, the automotive industry and polyurethane raw material manufacturers have developed polyurethane seat cushions that minimize hysteresis loss and improve vibration damping. However, the availability of conventional polyurethane raw materials can be limited, necessitating compensatory measures.

[0005] In particular, toluene diisocyanate, methylene diphenyl diisocyanate and polymethylene diphenyl diisocyanate were used as isocyanates in a conventional polyurethane foam composition, but the driving comfort of the seat cushion did not improve sufficiently.

[0006] Consequently, the development of a composition for manufacturing an automotive seat cushion with further improved static and dynamic comfort is urgently needed.

[0007] US 6 077 456 A describes a liquid polyisocyanate prepolymer comprising the reaction product of an organic polyisocyanate mixture and a polyoxyalkylene polyol.

[0008] The above information, disclosed in the background section, is provided solely for a better understanding of the background of the invention and may therefore contain information that does not constitute the prior art which is already known to a person skilled in the art in this country. SUMMARY

[0009] In a preferred aspect, the present invention provides a composition for manufacturing a vehicle seat cushion. The composition is manufactured using an isocyanate composition (B) polymerized with 1) polyether polyol having a weight-averaged molecular weight in a predetermined range using methylenediphenyl diisocyanate (M-MDI) and polymethylenediphenyl diisocyanate (P-MDI) as the isocyanate without the use of toluene diisocyanate, and a polyol composition (A) comprising polyether polyol (a1) having a weight-averaged molecular weight and a specific OH value, and polymer polyol (a2). As a result, to complete the present invention, the driving comfort of the seat cushion can be significantly improved by reducing hysteresis loss, vibration transmission rate, resonance frequency, and isolation frequency.

[0010] In one aspect of the present invention, a composition for producing a polyurethane foam for manufacturing a vehicle seat cushion with improved static and dynamic comfort can be provided. The composition comprises: an amount of 100 parts by weight of polyol composition (A), and an isocyanate composition (B).

[0011] The isocyanate composition (B) is obtained accordingly by addition polymerization of 1) an amount of approximately 1 to 5 parts by weight of polyether polyol (b2) in relation to 100 parts by weight of the polyol composition (A) and 2) an isocyanate composition (b1) including i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl isocyanate (monomeric MDI or M-MDI) in relation to 100 parts by weight of the polyol composition A and ii) an amount of approximately 8 to 21 parts by weight of polymethylene diphenyl isocyanate (P-MDI) in relation to 100 parts by weight of the polyol composition A.

[0012] The composition may further contain one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E) and a foaming agent (F).

[0013] Preferably, the composition may further comprise an amount of approximately 0.01 to 10 parts by weight of the crosslinking agent (C), an amount of approximately 0.01 to 3 parts by weight of the catalyst (D), an amount of approximately 0.01 to 3 parts by weight of the foam stabilizer (E) and an amount of approximately 1 to 5 parts by weight of the foaming agent (F) in relation to 100 parts by weight of the polyol composition (A).

[0014] The methylenediphenyl isocyanate (monomeric MDI or M-MDI) can have an NCO content of approximately 30 to 35 wt% in relation to the total weight of the methylenediphenyl isocyanate.

[0015] The polymethylenediphenyl isocyanate (P-MDI) has a weight-average molecular weight in the range of approximately 370 to 390 g / mol and an NCO content of approximately 25 to 35 wt% in relation to the total weight of the polymethylenediphenyl isocyanate.

[0016] The term “NCO content”, as used herein, refers to an index indicating the weight or mole percent of the NCO (N=C=O) group in isocyanate compounds. For example, the NCO groups can react with hydroxyl (OH) in polyol to form a polyurethane. In certain embodiments of the present invention, the NCO content in isocyanate compounds can be expressed in wt.%.

[0017] The polyol composition (A) comprises: an amount of approximately 85 to 95 wt% polyether polyol (a1); and an amount of approximately 5 to 15 wt% grafted polymer polyol (a2') in which one or more monomers selected from the group consisting of acrylonitrile and styrene are grafted onto a polyether polyol having a weight-average molecular weight of approximately 5,000 to 8,000 g / mol and an OH value of approximately 20 to 35 mg KOH / g. All weights refer to the total weight of the polyol composition (A).

[0018] As used herein, the term "grafted" means segmented or branched onto a polymer backbone structure with one or more different chemical groups (side chains) from the backbone structure. As used herein, the grafted polymer may include additional side chains segmented or branched from the backbone or main chain. The individual grafted chains may vary to impart desired properties to the main chain, such as water compatibility, elasticity, hydrophobicity, heat resistance, thermosensitivity, antibacterial activity, or the like. Examples of side chains grafted onto the preferred polymer of the present invention may include acrylonitrile and styrene.

[0019] The polyether polyol (a1) is obtainable by steps comprising the polymerization of propylene oxide (PO) and ethylene oxide (EO) and has a weight-averaged molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g. Preferably, the polyether polyol (a1) may contain approximately 10 to 20 wt% ethylene oxide (EO) and approximately 80 to 90 wt% propylene oxide (PO) as a percentage of the total weight of the polyether polyol (a1).

[0020] The polyether polyol (b2) is obtainable by steps involving the polymerization of propylene oxide and ethylene oxide, and accordingly has a weight-averaged molecular weight of approximately 3,000 to 8,000 g / mol and an OH value of approximately 20 to 60 mg KOH / g.

[0021] The term “OH value”, as used here, refers to an index for the content of hydroxyl groups (OH) in polyol polymers. For example, the OH groups can react with an NCO (N=C=O) group in an isocyanate composition to form a polyurethane. In certain embodiments of the present invention, the OH value in the polyol polymers can be expressed as a weight that can be provided in the form of KOH.

[0022] In another aspect, the present invention provides a molded object for a vehicle seat cushion, which was produced using the composition for the production of the polyurethane foam as described herein.

[0023] Furthermore, a composition for the production of a polyurethane foam is provided. The composition comprises: an amount of 100 parts by weight of a polyol composition (A), and an isocyanate composition (B). The isocyanate composition (B) comprises: 1) an amount of approximately 1 to 5 parts by weight of polyether polyol (b2) in relation to 100 parts by weight of the polyol composition (A), and 2) an isocyanate composition (b1) comprising i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl isocyanate (M-MDI) in relation to 100 parts by weight of the polyol composition (A), and ii) an amount of approximately 8 to 21 parts by weight of polymethylene diphenyl isocyanate (P-MDI) in relation to 100 parts by weight of the polyol composition (A).

[0024] The composition may further comprise one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E), and a foaming agent (F). Preferably, the composition may further comprise an amount of approximately 0.01 to 10 parts by weight of the crosslinking agent (C), an amount of approximately 0.01 to 3 parts by weight of the catalyst (D), an amount of approximately 0.01 to 3 parts by weight of the foam stabilizer (E), and an amount of approximately 5 parts by weight of the foaming agent (F) per 100 parts by weight of the polyol composition (A).

[0025] The methylenediphenyl isocyanate (M-MDI) can accordingly have an NCO content of approximately 30 to 35 wt% based on the total weight of the methylenediphenyl isocyanate, and the polymethylenediphenyl isocyanate (P-MDI) can accordingly have a weight-averaged molecular weight in the range of approximately 370 to 390 g / mol and an NCO content of approximately 25 to 35 wt% based on the total weight of the polymethylenediphenyl isocyanate.

[0026] The polyol composition (A) comprises: an amount of approximately 85 to 95 wt% polyether polyol (a1); and an amount of approximately 5 to 15 wt% of a grafted polymer polyol (a2') in which one or more monomers selected from the group consisting of acrylonitrile and styrene are grafted onto a polyether polyol having a weight-average molecular weight of 5,000 to 8,000 g / ml and an OH value of 20 to 35 mg KOH / g, based on the total weight of the polyol composition (A). The polyether polyol (a1) comprises, according to the composition, propylene oxide (PO) and ethylene oxide (EO) and has a weight-average molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g.

[0027] Preferably the polyether polyol (a1) may comprise an amount of approximately 10 to wt% ethylene oxide (EO) and an amount of approximately 80 to 90 wt% propylene oxide (PO), wherein all wt% values ​​refer to the total weight of the polyether polyol (a1).

[0028] The polyether polyol (b2) comprises propylene oxide and ethylene oxide and has a weight-average molecular weight of approximately 3,000 to 8,000 g / mol and an OH value of approximately 20 to 60 mg KOH / g.

[0029] Furthermore, a vehicle will be provided which may include the composition described herein.

[0030] According to various exemplary embodiments of the present invention, a seat can exhibit improved comfort by maintaining the hysteresis loss using the composition for manufacturing the polyurethane foam. For example, the hysteresis loss can be approximately 20% or less. Furthermore, ride comfort can be substantially improved by reducing the vibration transmission rate, one of the vibration characteristics, to approximately 3.0 or less, and the isolation frequency and resonance frequency can be substantially reduced compared to a conventional seat cushion to minimize vibration generated by the road surface and the vehicle during travel.

[0031] Since conventional seat cushions have a large surface thickness and roughness when mounted on a frame, friction between the frame and the cushion can cause noise. To prevent this noise, the back of the seat cushion was coated with an anti-noise agent. In contrast, the seat cushion produced according to the present invention can be soft and moist, the noise level can be reduced, and a significantly smaller amount of anti-noise agent can be used.

[0032] Furthermore, conventional seat cushions contain specific isocyanate mixed with 20 to 30 wt% toluene diisocyanate to improve the foaming rate. In this case, the foam hardens slowly, and therefore, at a temperature of 55 to 65°C, it is removed from the mold within approximately 5 minutes. However, the hardening of the molded product can be improved when using the composition of the present invention, and therefore the foam can be removed within approximately 3 to 4 minutes, thus significantly reducing the removal time. This allows for an increase in the production quantity of seat cushions.

[0033] In other words, the present invention can provide the benefits of maximizing the driving comfort of a driver and a passenger by improving the comfort function of the vehicle seat cushion, maintaining the moist and soft texture of the seat cushion, and increasing productivity.

[0034] Further aspects and preferred embodiments of the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments shown in the accompanying drawings, which are intended for illustrative purposes only and are therefore not limiting to the present invention, and wherein: Fig. 1A and Fig. 1B Show exemplary hysteresis loss curves of the comparison examples 1A and 6B; and Fig. Two exemplary curves are shown to compare the vibration characteristics of comparison example 1 and example 1.

[0036] It should be assumed that the accompanying drawings are not necessarily to scale and are a somewhat simplified representation of various preferred features illustrating the basic principles of the invention. The specific embodiments of the present invention, as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, are partly determined by the specific intended application and environment of use.

[0037] In the figures, the reference numerals refer to the same or equivalent parts of the present invention in all figures of the drawing. DETAILED DESCRIPTION

[0038] The terminology used herein serves only to describe individual exemplary embodiments and is not intended to limit the invention. As used herein, the singular forms "a" and "the" are to include the plural forms as well, unless the context clearly indicates otherwise. It is further understood that the terms "comprises" and / or "comprehensive," when used in this description, specify the presence of the indicated features, numbers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more further features, numbers, steps, operations, elements, components, and / or their groups. The term "and / or," as used herein, includes all combinations of one or more of the related listed terms.

[0039] Unless specifically stated or evident from the context, the term "approximately" as used herein is to be understood as being within a range of normal tolerance in the prior art, for example, within two standard deviations of the mean. "Approximately" may be understood as being within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise evident from the context, all numerical values ​​provided herein are modified by the term "approximately".

[0040] It is understood that the term "vehicle" or "vehicle-like" or any other similar term as used herein includes motor vehicles in general, such as passenger cars including all-terrain sports cars (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum). As defined herein, a hybrid vehicle is a vehicle that has two or more energy sources, for example, both gasoline-powered and electric-powered vehicles.

[0041] Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention is described in connection with exemplary embodiments, it is understood that the present description is not intended to limit the invention to these exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents, and further embodiments that fall within the basic concept and scope of the attached claims, as defined by the attached claims.

[0042] The present invention will now be described in detail as an exemplary embodiment.

[0043] The present invention provides a polyurethane foam composition. The composition comprises: an amount of 100 parts by weight of polyol composition A, and an isocyanate composition B. The isocyanate composition B is obtained by steps comprising the polymerization of a) an amount of approximately 1 to 5 parts by weight of polyether polyol b2 with 2) an isocyanate composition b1 including i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl diisocyanate (M-MDI) in relation to 100 parts by weight of polyol composition A, and ii) an amount of approximately 9 to 21 parts by weight of polymethylene diphenyl diisocyanate (P-MDI) in relation to 100 parts by weight of polyol composition A.

[0044] The composition of the present invention may further comprise one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E), and a foaming agent (F). Preferably, the composition may further comprise an amount of approximately 0.01 to 10 parts by weight of the crosslinking agent (C), an amount of approximately 0.01 to 3 parts by weight of the catalyst (D), an amount of approximately 0.01 to 3 parts by weight of the foam stabilizer (E), and an amount of approximately 1 to 5 parts by weight of the foaming agent (F) with respect to the total weight of the polyol composition (A).

[0045] Each component is described in detail below.

[0046] The polyol composition A is a mixture of: a polyether polyol (a1) with a weight-average molecular weight of 6,000 to 8,000 g / mol and an OH value of 20 to 30 mg KOH / g and a grafted polymer polyol (a2') in which one or more monomers selected from the group consisting of acrylonitrile and styrene monomers are grafted onto a polyether polyol with a weight-average molecular weight of approximately 5,000 to 8,000 g / mol and an OH value of approximately 20 to 35 mg KOH / g.

[0047] The polyether polyol a1 is obtained by steps involving the addition polymerization of propylene oxide (PO) and ethylene oxide (EO), and the resulting polyether polyol a1 has a weight-average molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g. If the weight-average molecular weight of the polyether polyol a1 is less than approximately 6,000 g / mol or the OH value of the polyether polyol a1 is greater than approximately 30 mg KOH / g, the hysteresis loss may be significantly worsened, and a collapse defect, in which the foam dents during the manufacture of the seat cushion, may occur. If the weight-averaged molecular weight of the polyether polyol a1 is higher than approximately 8,000 g / mol or the OH value of the polyether polyol a1 is less than approximately 20, a shrinkage defect of the seat cushion may occur due to a pressure difference between inside and outside.Accordingly, it is preferred that the polyether polyol has the properties in the area as described above.

[0048] Preferably, the polyether polyol a1 may contain approximately 10 to wt% ethylene oxide (EO) and approximately 80 to 90 wt% propylene oxide (PO) by weight of the polyether polyol a1. If the ethylene oxide content is less than approximately 10 wt% or more than approximately 20 wt%, a molding defect occurs due to indentation and shrinkage of the foam during foaming.

[0049] A polymerization initiator can be used in the addition polymerization reaction and can be one or more selected from the group consisting of ethylene glycol, glycerol, triethanolamine, pentaerythritol, toluenediamine, ethylenediamine, 4,4'-diamidiphenylmethane, sorbitol and sucrose.

[0050] The polyether polyol a1 is present in an amount of approximately 85 to 95 wt% of the total weight of the polyol composition A. If the polyether polyol a1 is less than approximately 60 wt%, the hardness of the seat cushion may increase, and consequently, the hysteresis loss and vibration transmission performance may decrease significantly. If the amount of polyether polyol a1 is more than approximately 99 wt%, the hardness of the seat cushion may decrease significantly, rendering it unmarketable. Accordingly, it is preferred that the polyether polyol a1 be used within the range described above.

[0051] The polymer polyol a2' is a grafted polymer polyol in which one or more monomers selected from the group consisting of acrylonitrile and styrene are grafted onto a polyether polyol with a weight-average molecular weight of 5,000 to 8,000 g / mol and an OH value of 20 to 35 mg KOH / g. The polymer polyol a2 is present in an amount of approximately 5 to 15 wt% of the total weight of the polyol composition A.

[0052] If the weight-averaged molecular weight of the polyether polyol is less than approximately 5,000 g / mol or the OH value is less than approximately 20, the hysteresis loss can be significantly lower. If the weight-averaged molecular weight of the polyether polyol is greater than approximately 8,000 g / mol or the OH value is greater than approximately 35, a shrinkage defect of the seat cushion may occur due to the difference between internal and external pressure. Accordingly, it is preferred that the polyether polyol be used within the range defined above.

[0053] If the amount of polymer polyol a2 is less than approximately 1 wt% of the total weight of polyol composition A, the hardness of the seat cushion may be significantly reduced, rendering it unmarketable. If the amount of polymer polyol a2 is more than approximately 40 wt%, the hardness of the seat cushion may be significantly increased, and consequently, the hysteresis loss and vibration transmission performance may be significantly reduced. Accordingly, it is preferred that the polymer polyol a2 be contained in polyol composition A within the range described above.

[0054] Isocyanate composition B can contain methylenediphenyl isocyanate (M-MDI) and polymethylenediphenyl isocyanate (P-MDI) without the use of toluene diisocyanate. Isocyanate composition B can be obtained by addition polymerization of polyether polyol with a weight-average molecular weight of approximately 3,000 to 8,000 g / mol with the isocyanate mixture (M-MDI and P-MDI).

[0055] Preferably, the methylenediphenyl isocyanate (M-MDI) may have an NCO (N=C=O) content of approximately 30 to 35 wt% based on the total weight of the M-MDI. If the NCO content is less than approximately 30 wt%, the density of the seat cushion may be significantly increased due to a low urethane foaming rate, and thus fuel efficiency may be reduced. If the NCO content is more than approximately 35 wt%, the density of the seat cushion may be significantly reduced, and thus the service life of the seat cushion may be reduced. Accordingly, the NCO content of the M-MDI may be within the range described above.

[0056] Preferably, the polymethylene diphenyl isocyanate (P-MDI) has a weight-averaged molecular weight in the range of approximately 370 to 390 g / mol, and the NCO content can be in the range of approximately 25 to 35 wt% of the total weight of the P-MDI. If the weight-averaged molecular weight is less than approximately 370 g / mol, the tear strength and elongation of the seat cushion may be reduced, and if the weight-averaged molecular weight is greater than approximately 390 g / mol, the tensile strength of the seat cushion may be reduced. If the NCO content is less than approximately 25 wt%, the density of the seat cushion may be significantly increased due to the low urethane foaming rate, and thus fuel efficiency may be reduced. If the NCO content is greater than approximately 35 wt%, the density of the seat cushion may be significantly increased due to the low urethane foaming rate, and thus fuel efficiency may be reduced.If the percentage is -%, the thickness of the seat cushion can be significantly reduced, and therefore the durability of the seat cushion can be reduced. Accordingly, the polymethylene diphenyl isocyanate can exhibit properties in the areas described above.

[0057] The isocyanate composition B is obtained by steps comprising the addition polymerization of a) an amount of approximately 1 to 5 parts by weight of polyether polyol b2, having a weight-averaged molecular weight of approximately 3,000 to 8,000 g / mol, with 2) the isocyanate mixture b1. The isocyanate mixture b1 contains i) an amount of approximately 15 to 40 parts by weight of methylenediphenyl isocyanate (M-MDI) per 100 parts by weight of polyol composition A, and ii) an amount of approximately 8 to 21 parts by weight of polymethylenediphenyl isocyanate (P-MDI) per 100 parts by weight of polyol composition A.

[0058] Preferably, the mixing ratio of methylenediphenyl isocyanate (M-MDI) : polymethylenediphenyl isocyanate (P-MDI) : polyether polyol in the isocyanate compound can be approximately 30 to 80 wt% : 20 to 45 wt% : 1 to 30 wt%, or particularly approximately 40 to 65 wt% : 30 to 40 wt% : 2 to 7 wt%. If the polyether polyol content is smaller than the predetermined range, the additive effect may be significantly reduced, and if the content is larger than the predetermined range, the foam hardness and productivity may be significantly reduced; thus, the mixing ratio in the range described above is preferred.

[0059] Polyether polyol b2 is obtained from the synthesis of isocyanate composition B by steps involving the addition polymerization of propylene oxide and ethylene oxide. Furthermore, polyether polyol b2 has a weight-average molecular weight of 3,000 to 8,000 g / mol and an OH value of approximately 20 to 60 mg KOH / g. If the weight-averaged molecular weight of polyether polyol b2 is less than approximately 3,000 g / mol or the OH value of polyether polyol b2 is greater than approximately 60 mg KOH / g, the hysteresis loss and vibration transmission power may be significantly reduced, and if the weight-averaged molecular weight of polyether polyol b2 is greater than approximately 8,000 g / mol or the OH value of polyether polyol b2 is less than approximately 20 mg KOH / g, deformation of the seat cushion shape may occur due to a difference between internal and external pressure.Accordingly, the polyether polyol can exhibit these properties in the areas described above. In comparison, the polyether polyol b2, which is used in the preparation of the isocyanate composition, can differ from the polyether polyol a1, which is contained in the polyol composition A.

[0060] As described above, the composition of the present invention may further comprise one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E), and a foaming agent (F). Preferably, the additive may be added primarily to the polyol composition and then added to the composition during a reaction in general, or alternatively, the additive may be added and then mixed into the isocyanate or the foaming agent.

[0061] In particular, the crosslinking agent (C) as used herein may be glycol-based or amine-based and may be selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, pentylerythritol, diethanolamine, triethanolamine, ethylenediamine, triethylenetetraamine, methylene orthochloroaniline, 4,4-diphenylmethanediamine, 2,6-dichloro-4,4-diphenylmethanediamine, 2,4-toluenediamine and 2,6-toluenediamine, examples of which are not necessarily limited.

[0062] The crosslinking agent can increase the bonding strength between molecules to improve general properties such as tensile and shear strength, while simultaneously increasing hydrolysis resistance to maintain product properties under high temperature and humidity conditions. However, the amount of crosslinking agent required may be only sufficient to meet the desired properties of the final product, as productivity can be reduced due to issues such as closed cells and poor flowability.

[0063] Preferably, the crosslinking agent can be used in an amount of approximately 0.01 to 10 parts by weight and / or, more specifically, in an amount of approximately 0.01 to 5 parts by weight per 100 parts by weight of polyol. If the amount of crosslinking agent is less than approximately 0.01 parts by weight, its effect may be significantly reduced, and if the amount of crosslinking agent is more than approximately 10 parts by weight, the flowability may deteriorate, and thus the rate of mold defects may increase significantly. Accordingly, the crosslinking agent can be used within the range described above.

[0064] The catalyst D may contain a general catalyst used in the production of a polyurethane foam body and is not particularly limited. The catalyst may contain an amine catalyst selected from the group consisting of triethylenediamine, bis(diethylaminoethyl) ether, tripropylamine, triisopropanolamine, tributylamine, triethylamine, N-methylmorpholine, diethylenetriamine bis(2-(N,N-diethylaminoethyl) ether) and their salts.

[0065] The catalyst can be used in an amount of approximately 0.01 to 3 parts by weight per 100 parts by weight of polyol. If the amount of catalyst is less than approximately 0.01 parts by weight, curability and polymerization may be significantly reduced, and thus productivity may be substantially decreased. If the catalyst is present in an amount greater than approximately 3 parts by weight, the defect rate may be significantly increased due to a deterioration in flowability, corresponding to an initial increase in curability. Accordingly, the catalyst can be used within the range described above.

[0066] The foam stabilizer (E), as used here, can promote interreactivity by reducing emulsification between materials and surface tension, and may include a foam stabilizer generally used to produce a polyurethane foam body. Exemplary foam stabilizers may include, but are not limited to, an organosilicate surfactant.

[0067] The foam stabilizer can be used in an amount of approximately 0.01 to 3 parts by weight per 100 parts by weight of polyol. If the amount of foam stabilizer is less than approximately 0.01 parts by weight, the foam cannot be produced by phase separation between the materials, and if the foam stabilizer is used in an amount greater than 3 parts by weight, productivity can be significantly reduced due to excessive formation of closed cells. Preferably, the foam stabilizer can be used within the range described above.

[0068] The foaming agent (F) may contain water, or the foaming agent F may comprise Freon-based (CFC, HCFC, and HFC) or pentane-based (cyclopentane) compounds, which can be general physical foaming agents. However, the Freon-based foaming agent may not be practical due to a global regulation to prevent ozone depletion, and the pentane-based foaming agent may require substantial investment to prevent explosion due to its explosive properties associated with even a small amount of air.

[0069] Preferably, the foaming agent can be used in an amount of approximately 1 to 5 parts by weight per 100 parts by weight of the polyol composition. If the foaming agent is used in an amount of less than approximately 1 part by weight, the problem of non-formability may occur due to deterioration of the foaming process, and the density quality may deteriorate. If the foaming agent is used in an amount of more than approximately 5 parts by weight, the properties may deteriorate significantly due to excessive foaming.

[0070] The resin composition of the present invention may, in addition to the main components, also include one or more additives selected from the group consisting of stabilizers, fillers, dyes, flame retardants and antimicrobial agents, if necessary.

[0071] The composition for producing the polyurethane foam according to various exemplary embodiments of the present invention can reduce the hysteresis loss, which is an index of static comfort with respect to the vehicle seat cushion with a density in a range of approximately 50 to 80 kg / m³. 3 The composition of the present invention reduces the vibration transmission rate and the resonance and isolation frequencies, thereby improving static and dynamic comfort compared to a conventional seat cushion. Accordingly, the composition of the present invention can be provided in a polyurethane foam for a vehicle seat cushion with improved driving comfort.

[0072] The invention will now be described in greater detail with reference to the examples. The following examples are intended only to illustrate the present invention, and the scope of the present invention is not limited to these examples. EXAMPLES

[0073] The following examples illustrate the invention, but are not intended to limit it. Comparative examples 1 to 15

[0074] An isocyanate composition was prepared according to the components and proportions in Tables 1 to 3 below. The isocyanate composition was then mixed and stirred with a polyol composition, reacted, and poured into an aluminum square mold (400 × 400 × 100 mm). 3 The mixture, heated to 60°C, was injected. After 4 minutes, the mold was removed to produce a polyurethane foam. Example 1

[0075] A polyurethane foam was produced using the same method as comparative examples 1 to 15 according to a composition ratio from Table 3 below. Table 1 Composition for the production of polyurethane foam (unit: part by weight) classification Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Isocyanate compound M-MDI #1) 27,5 31,5 29,4 31,5 27,3 23,1 18,9 P-MDI #2) 12,5 10,5 10,5 8,4 12,6 16,8 21,0 TDI #3) 10 - - - - - - Polyol A #4) - - 2,1 2,1 2,1 2,1 2,1 Polyol composition Polyol composition A #5) 100 - - - - - - Polyol composition B #6) - 100 100 100 100 100 100 #1) Methylene diphenyl diisocyanate, NCO%: 33.5% by weight #2) Polymethylene diphenyl diisocyanate, NCO %: 31.0 wt.% #3) Toluene diisocyanate, NCO%: 48.3% by weight #4) Polyether polyol (weight-averaged molecular weight of 3,000), obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #5) Product of KPX Chemical Corporation, polyol composition for the manufacture of vehicle seat cushions (product name: MBR-660) #6) Product of Kumho Mitsui Chemicals Corporation, polyol composition for the manufacture of vehicle seat cushions (product name: RP-3000) Table 2 Composition for the production of polyurethane foam (unit: part by weight) classification Comparative example 8 Comparative example 9 Comparative example 10 Comparative example 11 Isocyanate composition (B) M-MDI 27,3 27,3 27,3 27,3 P-MDI 12,6 12,6 12,6 12,6 Polyol B #7) 2,1 - - - Polyol C #8) - 2,1 - - Polyol D #9) - - 2,1 - Polyol E #10) - - - 2,1 Polyol composition Polyol composition B 100 100 100 100 #7) Polyether polyol (weight-averaged molecular weight of 2,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #8) Polyether polyol (weight-averaged molecular weight of 5,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #9) Polyether polyol (weight-averaged molecular weight of 6,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #10) Polyether polyol (weight-averaged molecular weight of 8,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide Table 3 Composition for the production of polyurethane foam (unit: part by weight) classification Comparative example 12 Comparative example 13 Comparative example 14 Comparative example 15 Example 1 M-MDI 27,3 27,3 27,3 27,3 27,3 Isocyanate composition g #11) P-MDI 12,6 12,6 12,6 12,6 12,6 Polyol E 2,1 2,1 2,1 2,1 2,1 Polyol composition g Polyol F#12) 100 - - - - Polyol G#13) - 100 - - - Polyol H#14) - - 100 - - Polyol I #15) - - - 100 90 Polyol J #16) - - - - 10 Additive Networking tool (C)#17) 1,0 1,0 1,0 1,0 1,0 Catalyst(D) #18) 1,0 1,0 1,0 1,0 1,0 Foam stabilizer (E) #19) 0,8 0,8 0,8 0,8 0,8 Foaming agent (F)#20) 3,0 3,0 3,0 3,0 3,0 #11) NCO % 29.0, product (product name: COSMONATE CG-3000) of Kumho Mitsui Chemicals Corporation, isocyanate composition according to the present invention. #12) Polyether polyol (weight-averaged molecular weight of 4,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #13) ) Polyether polyol (weight-averaged molecular weight of 6,000) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #14) ) Polyether polyol (weight-averaged molecular weight of 6,500) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #15) ) Polyether polyol (weight-averaged molecular weight of 7,500) obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #16) Polymer polyol produced by dispersing acrylonitrile and styrene monomer in polyether polyol with a weight-averaged molecular weight of 6,500 obtained by using glycerol as an initiator and addition polymerization of propylene oxide and ethylene oxide #17) Diethanolamine #18) Amine catalyst (product of Air Products Co. Ltd.) #19) Organosilicone surfactant product from Momentive Corp.) #20) Distilled water or ion exchange water TEST EXAMPLES Measurement of properties

[0076] Regarding the polyurethane foams produced in comparative examples 1 to 15 and example 1, the density, hardness, hysteresis loss, resonance frequency, vibration transmission rate, and isolation frequency of the foam were measured after 24 hours, and the results of these properties are listed in Tables 4 to 6 below. The test procedures were as follows. 1) Specific gravity: The specific gravity was measured using ASTM D3574-05 TEST A. (2) Hardness: The hardness was measured using ATM D3574-05 TEST B. (3) Hysteresis loss: The hysteresis loss was measured using ASTM D3574-05 TEST X6. The measured hysteresis loss can indicate that static comfort increases when the measured value decreases. (4) Maximum vibration transmission rate / resonant frequency / isolation frequency: The maximum vibration transmission rate / resonant frequency / isolation frequency was measured using MS200-34 Section 4.8. The measured value may indicate that a reduction in the measured value indicates that the seat cushion absorbs the vibration transmitted from a vehicle and minimizes the specific frequency that reduces comfort caused by vehicle vibrations while driving, in order to improve dynamic comfort. Table 4 Result of property measurement 1 classification Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Density (kg / m³) 3 ) 55,1 65,2 65,1 65,0 64,8 65,0 65,0 Hardness (kgf / 314cm) 2 ) 2,3 24,1 23,9 24,5 24,3 23,8 24,2 Hysteresis loss (%) 26,5 22,3 21,1 22,5 17,8 17,1 22,6 Vibration characteristics Maximum vibration transfer rate (A / A0) 4,87 3,45 3´,23 3,51 3,20 3,14 3,42 Resonance frequency (Hz) 4,99 4,47 4,44 4,45 4,23 4,05 4,46 Insulation frequency (Hz,A / A0=1) 7,45 6,99 6,74 6,96 6,24 6,01 6,94

[0077] According to the results in Table 4, in comparative example 1, toluene diisocyanate was present in an amount of 10 parts by weight as polyurethane foam produced using isocyanate for the manufacture of a conventional vehicle seat cushion, and the hysteresis loss and vibration properties were significantly reduced compared to the example.

[0078] Meanwhile, in comparative example 2, it was shown that the hysteresis loss and the vibrational properties improved simultaneously without adding toluene diisocyanate to the isocyanate compound.

[0079] In comparison example 3, it was evident that, in comparison to comparison example 1, the hysteresis loss and the vibrational properties were further improved by using the compound obtained by adding a predetermined amount of polyether polyol to the isocyanate composition, without adding toluene diisocyanate to the isocyanate compound.

[0080] In comparative examples 4 to 7, compared to comparative example 3, it was evident that the polymethylene diisocyanate (P-MDI) content was increased, and the hysteresis loss and vibration characteristics were further improved. Comparative example 6, in which 16.8 parts by weight of polymethylene diisocyanate (P-MDI) were used per 100 parts by weight of the polyol composition, showed the best result, while comparative examples 4 (8.4 parts by weight) and 7 (21 parts by weight) confirmed that the difference in effect was not particularly large.

[0081] Fig. 1A and Fig.Figure 1B shows the hysteresis loss curves of comparison example 1A and comparison example 6B in comparison. It can thus be concluded that when only methylenediphenyl diisocyanate (M-MDI) and polymethylenediphenyl diisocyanate (P-MDI) were used as isocyanates without the use of toluene diisocyanate, the static and dynamic comfort improved.

[0082] As a result, comparative examples 1 to 7 confirmed that in the case of the production of polyurethane foam, the hysteresis loss and the vibration characteristics were improved by using isocyanate including a predetermined amount of polymethylene diisocyanate without using toluene diisocyanate. Table 5 Result of property measurement 2 classification Comparative example 8 Comparative example 9 Comparative example 10 Comparative example 11 Density (kg / m³) 3 ) 65,4 65,0 65,2 65,1 Hardness (kgf / 314cm) 2 ) 25,3 24,9 24,8 24,9 Hysteresis loss (%) 19,0 17,3 17,1 16,9 Vibration characteristics Maximum vibration transfer rate (A / A0) 3,24 3,20 3,18 3,10 Resonance frequency (Hz) 4,28 4,18 4,05 4,01 Isolation frequency (Hz,A / A0=1) 6,55 6,36 6,26 6,01

[0083] As can be seen from Table 5, in the case of comparison examples 8 to 11, polyether polyols with high and low molecular weights were used in the isocyanate compound compared to comparison example 5. In comparison example 8 (molecular weight of 2,000), virtually no effect was observed, and in comparison example 9 (molecular weight of 5,000), a relatively small effect was observed compared to comparison examples 10 and 11. No commercially available polyether polyol with a molecular weight of 9,000 or more was found in the comparison.

[0084] As a result, comparative examples 8 to 11 confirmed that, in the case of the polyether polyol used in the preparation of the isocyanate compound, the hysteresis loss and the vibrational properties improved when the weight-averaged molecular weight was greater than 2,000 g / mol. Accordingly, it is preferred that the isocyanate composition be prepared using polyether polyol with a weight-averaged molecular weight of 3,000 to 8,000 g / mol. Table 6 Result of property measurement 3 classification Comparative example 12 Comparative example 13 Comparative example 14 Comparative example 15 Example 1 Density (kg / m³) 3 ) 64,6 64,8 65,0 64,7 65,1 Hardness (kgf / 314cm) 2 ) 24,7 24,6 24,7 24,4 24,2 Hysteresis loss (%) 20,9 18,5 17,8 16,9 16,1 Vibration characteristics Maximum vibration transfer rate (A / A0) 4,82 4,27 3,89 2,87 2,80 Resonance frequency (Hz) 5,55 4,76 4,23 3,87 3,53 Insulation frequency (Hz,A / A0=1) 7,32 6,87 6,76 5,99 5,74

[0085] As can be seen from Table 6, in the case of comparison examples 12 to 15, it was shown that static and dynamic comfort improved when the molecular weight of the polyether polyol in the polyol composition was increased, but the effect decreased significantly, and in comparison example 12 (molecular weight of 4,000) the effect decreased the most.

[0086] However, in the case of Example 1, using the polyol composition including polyether polyol and polymer polyol with a predetermined amount according to the present invention, the effect was found to be quite excellent.

[0087] Fig. Figure 2 represents a curve comparing the variation characteristics of comparison example 1 and example 1. However, in the case of example 1, which uses polyether polyol and polymer polyol as the polyol composition, it is shown that the static and dynamic comfort was significantly improved.

[0088] As described above, it was shown that the polypropylene resin composition of Example 1 according to the present invention can reduce the hysteresis loss, the vibration transmission rate, the resonance frequency and the isolation frequency by appropriate use of the respective components to improve the driving comfort of the seat cushion when driving the vehicle.

Claims

A composition for the manufacture of a polyurethane foam, comprising: an amount of 100 parts by weight of a polyol composition (A), an isocyanate composition (B) wherein the isocyanate composition (B) is obtainable by steps comprising the polymerization of 1) an amount of approximately 1 to 5 parts by weight of polyether polyol (b2) in relation to 100 parts by weight of the polyol composition (A) and 2) an isocyanate composition (b1) comprising i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl isocyanate (M-MDI) in relation to 100 parts by weight of the polyol composition (A) and ii) an amount of approximately 8 to 21 parts by weight of polymethylene diphenyl isocyanate (P-MDI) in relation to 100 parts by weight of the polyol composition (A), wherein the polyether polyol (b2) is obtainable by steps comprising the polymerization of propylene oxide (PO) and ethylene oxide (EO) and a weight-averaged molecular weight of approximately 3,000 to 8.000 g / mol and has an OH value of 20 to 60 mg KOH / g, wherein the polyol composition (A) comprises: an amount of approximately 85 to 95 wt.% polyether polyol (a1); and an amount of approximately 5 to 15 wt% of a grafted polymer polyol (a2') in which one or more monomers selected from the group consisting of acrylonitrile and styrene are grafted onto a polyether polyol having a weight-average molecular weight of 5,000 to 8,000 g / mol and an OH value of 20 to 35 mg KOH / g, in relation to the total weight of the polyol composition (A), wherein the polyether polyol (a1) is obtainable by steps comprising the polymerization of propylene oxide (PO) and ethylene oxide (EO) and has a weight-average molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g. Composition according to claim 1, further comprising: one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E) and a foaming agent (F), wherein the composition further comprises an amount of approximately 0.01 to 10 parts by weight of the crosslinking agent (C), an amount of approximately 0.01 to 3 parts by weight of the catalyst (D), an amount of approximately 0.01 to 3 parts by weight of the foam stabilizer (E) and an amount of approximately 1 to 5 parts by weight of the foaming agent (F) in relation to 100 parts by weight of the polyol composition (A). Composition according to claim 1 wherein the methylenediphenyl isocyanate (M-MDI) has an NCO content of approximately 30 to 35 wt% in relation to the total weight of the methylenediphenyl isocyanate. Composition according to claim 1, wherein the polymethylenediphenyl isocyanate (P-MDI) has a weight-averaged molecular weight in the range of approximately 370 to 390 g / mol and an NCO content of approximately 25 to 35 wt% with respect to the total weight of the polymethylenediphenyl isocyanate. Composition according to claim 1, wherein the polyether polyol (a1) comprises an amount of approximately 10 to 20 wt% ethylene oxide (EO) and an amount of approximately 80 to 90 wt% propylene oxide (PO), wherein all wt% values ​​refer to the total weight of the polyether polyol (a1). Composition for the manufacture of a polyurethane foam, comprising: an amount of 100 parts by weight of a polyol composition (A), an isocyanate composition (B), wherein the isocyanate composition (B) comprises: 1) an amount of approximately 1 to 5 parts by weight of the polyether polyol (b2) in relation to 100 parts by weight of the polyol composition (A), and 2) an isocyanate composition (b1), comprising i) an amount of approximately 15 to 40 parts by weight of methylene diphenyl isocyanate (M-MDI) in relation to 100 parts by weight of the polyol composition (A), and ii) an amount of approximately 8 to 21 parts by weight of polymethylene diphenyl isocyanate (P-MDI) in relation to 100 parts by weight of the polyol composition (A), wherein the polyether polyol (b2) comprises propylene oxide and ethylene oxide and has a weight-averaged molecular weight of approximately 3,000 to 8,000 g / mol and has an OH value of approximately 20 to 60 mg KOH / g, the polyol composition (A) comprising: an amount of approximately 85 to 95 wt.-% polyether polyol (a1); and an amount of approximately 5 to 15 wt% of a grafted polymer polyol (a2') in which one or more monomers selected from the group consisting of acrylonitrile and styrene are grafted onto a polyether polyol having a weight-average molecular weight of 5,000 to 8,000 g / mol and an OH value of 20 to 35 mg KOH / g, in relation to the total weight of the polyol composition (A), wherein the polyether polyol (a1) comprises propylene oxide (PO) and ethylene oxide (EO) and has a weight-average molecular weight of approximately 6,000 to 8,000 g / mol and an OH value of approximately 20 to 30 mg KOH / g. The composition according to claim 6, further comprising: one or more additives selected from the group consisting of a crosslinking agent (C), a catalyst (D), a foam stabilizer (E) and a foaming agent (F), wherein the composition further comprises an amount of approximately 0.01 to 10 parts by weight of the crosslinking agent (C), an amount of approximately 0.01 to 3 parts by weight of the catalyst (D), an amount of approximately 0.01 to 3 parts by weight of the foam stabilizer (E) and an amount of approximately 1 to 5 parts by weight of the foaming agent (F) in relation to 100 parts by weight of the polyol composition (A). Composition according to claim 6, wherein the methylenediphenyl isocyanate (M-MDI) has an NCO content of approximately 30 to 35 wt% in relation to the total weight of the methylenediphenyl isocyanate. Composition according to claim 6, wherein the polymethylenediphenyl isocyanate (P-MDI) has a weight-averaged molecular weight in the range of approximately 370 to 390 g / mol and an NCO content of approximately 25 to 35 wt% with respect to the total weight of the polymethylenediphenyl isocyanate. Composition according to claim 6, wherein the polyether polyol (a1) comprises an amount of approximately 10 to 20 wt% ethylene oxide (EO) and an amount of approximately 80 to 90 wt% propylene oxide (PO), wherein all wt% values ​​refer to the total weight of the polyether polyol (a1).

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