Flame-retardant polyurethane reaction system and application thereof

Abstract

The invention discloses a polyurethane reaction system, application of the polyurethane reaction system in encapsulation of an automobile battery product, and the automobile battery product containing a cured product of the polyurethane reaction system. According to the polyurethane reaction system disclosed by the invention, the polyol component and / or the isocyanate component comprise at least one phosphate flame retardant F1 which is solid at the temperature of 25 DEG C, and the phosphate flame retardant F1 is dissolved in the polyol component and / or the isocyanate component at the temperature of 25 DEG C, and forming a storage stable polyol flame retardant liquid mixture and / or isocyanate flame retardant liquid mixture.

Description

Technical Field

[0001] The present disclosure relates to the field of polyurethanes. More specifically, the present disclosure relates to a flame retardant polyurethane reaction system, its application in encapsulation of automotive battery products, and automotive battery products containing the cured product of the polyurethane reaction system. Background Art

[0002] Polyurethane materials with flame retardant function have been widely used in the fields of automobiles, construction, electronic products, etc. In order to achieve the flame retardant purpose of polyurethane materials, additional flame retardants are usually added or polyol components with flame retardant function are used.

[0003] Flame retardants can be divided into two types: solid flame retardants and liquid flame retardants. After traditional solid flame retardants are added to polyurethane components, it is difficult for the solid flame retardants to maintain uniform stability in the polyurethane components and they are prone to precipitation or precipitation, which can easily lead to problems such as clogging the machine and uneven flame retardancy of the polyurethane material. Summary of the invention

[0004] In view of the above problems, the present disclosure hopes to provide a polyurethane reaction system with good flame retardancy and good long-term storage stability.

[0005] According to one aspect of the present disclosure, there is provided a polyurethane reaction system, comprising:

[0006] (a) a polyol component comprising at least one isocyanate-reactive polyol; and

[0007] (b) an isocyanate component comprising at least one polyisocyanate;

[0008] Characterized in that the isocyanate component further comprises at least one solid phosphate flame retardant F1 at 25°C, and the phosphate flame retardant F1 is dissolved in the isocyanate component at 25°C to form a storage-stable isocyanate flame retardant liquid mixture.

[0009] According to another aspect of the present disclosure, another polyurethane reaction system is provided, comprising:

[0010] (a) a polyol component comprising at least one isocyanate-reactive polyol; and

[0011] (b) an isocyanate component comprising at least one polyisocyanate;

[0012] Characterized in that the polyol component further comprises at least one phosphate flame retardant F1 which is solid at 25°C, and the phosphate flame retardant F1 is dissolved in the polyol component at 25°C to form a storage-stable polyol flame retardant liquid mixture;

[0013] The polyol component further comprises at least one flame retardant F2 which is liquid at 25° C., or the polyol in the polyol component and the phosphate flame retardant F1 both contain phenyl groups.

[0014] According to another aspect of the present disclosure, there is provided an automotive battery product, characterized in that the automotive battery product comprises

[0015] Battery cells potted in polyurethane foam; and

[0016] The polyurethane foam is a cured product of the polyurethane reaction system according to the present disclosure.

[0017] In some embodiments, the automotive battery product includes a battery module or a battery pack. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present disclosure are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0019] The term "storage stable" as used in the present disclosure means that, when observed with the naked eye at room temperature (e.g., 25° C.), the polyol flame retardant liquid mixture / isocyanate flame retardant liquid mixture does not show any solid precipitation or solid separation for at least 10 days, preferably at least 20 days, and more preferably at least 30 days.

[0020] The "homogeneous liquid phase" mentioned in the present disclosure means that, through naked eye observation, at room temperature, the polyol flame retardant liquid mixture / isocyanate flame retardant liquid mixture does not show obvious phase separation (for example, forming more than two liquid layers, or forming a liquid layer and a solid layer) and the constituent substances are evenly distributed.

[0021] The molecular weight described in this disclosure refers to the number average molecular weight Mn.

[0022] The functionality described in the present disclosure is also referred to as equivalent functionality or average functionality. Methods for determining the functionality of polyols are known to those skilled in the art, for example, see M. Ionescu "Chemistry and Technology of Polyols for Polyurethanes", 2005, Rapra Technology Limited, pp. 34 to 39.

[0023] The density described in this disclosure can be measured according to ISO 1183, which is expressed in g / cm 3 express.

[0024] The flame retardancy rating of the present disclosure is measured according to the UL 94 Plastics Flammability Test.

[0025] The volume resistivity of the present disclosure is measured according to IEC 62631-3-1.

[0026] The viscosity of the present disclosure may be measured according to ASTM D2196-15 and is expressed in cp.s.

[0027] Polyurethane Reaction System I

[0028] According to the present disclosure, a polyurethane reaction system is provided, comprising:

[0029] (a) a polyol component comprising at least one isocyanate-reactive polyol; and

[0030] (b) an isocyanate component comprising at least one polyisocyanate;

[0031] Characterized in that the isocyanate component further comprises at least one solid phosphate flame retardant F1 at 25°C, and the phosphate flame retardant F1 is dissolved in the isocyanate component at 25°C to form a storage-stable isocyanate flame retardant liquid mixture.

[0032] In some embodiments, the isocyanate component optionally further comprises at least one flame retardant F2 which is liquid at 25°C.

[0033] According to the polyurethane reaction system disclosed herein, the isocyanate component containing the phosphate flame retardant F1 is a storage-stable isocyanate flame retardant liquid mixture. That is, by naked eye observation, at room temperature (e.g., 25° C.), no solid precipitation or solid precipitation is formed for at least 10 days, preferably at least 20 days, and more preferably at least 30 days.

[0034] In some preferred embodiments, the isocyanate flame retardant liquid mixture according to the present disclosure remains as a uniform liquid phase at room temperature for at least 10 days, preferably at least 20 days, and more preferably at least 30 days, that is, the isocyanate flame retardant liquid mixture does not show obvious phase separation (e.g., forming two or more liquid layers, or forming a liquid layer and a solid layer) and the constituent substances are evenly distributed.

[0035] This is very important for the polyurethane reaction system, because the polyol component and the isocyanate component are usually not used immediately after preparation, but need to be transported and stored for a period of time before use. If the phosphate flame retardant F1 precipitates or precipitates from the isocyanate component, it will block the machine on the one hand, and on the other hand, it will cause the flame retardant properties of the cured polyurethane material to be uneven.

[0036] Polyol components

[0037] As noted above, the polyol component comprises at least one isocyanate-reactive polyol.

[0038] Examples of suitable polyols include, but are not limited to, polyether polyols, graft polyether polyols, polyester polyols, polyolefin polyols, and mixtures thereof. In some preferred embodiments, the polyol is preferably a polyether polyol.

[0039] Polyether polyols are organic compounds containing at least ether and OH groups as functional groups. Polyether polyols are prepared using catalysts, for example from epoxides such as propylene oxide and / or ethylene oxide, or from tetrahydrofuran with hydrogen-active starter compounds such as aliphatic alcohols, phenols, amines, carboxylic acids, water and compounds based on natural substances such as sucrose, sorbitol or mannitol. These may include alkaline catalysts or double metal cyanide catalysts, such as those described in, for example, PCT / EP2005 / 010124, EP 90444 or WO 05 / 090440.

[0040] Polyester polyols are prepared, for example, from aliphatic or aromatic dicarboxylic acids and polyols, polythioether polyols, polyesteramides, hydroxylated polyacetals and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are described, for example, in "Kunststoffhandbuch", volume 7, "Polyurethane", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.

[0041] In some embodiments, the polyol has an average functionality equal to or greater than 2 (i.e., having at least two groups reactive to isocyanate), such as 2, 3, or 4. The polyol may be a dihydric polyol, a trihydric polyol, a tetrahydric polyol, or a higher polyol. In some preferred embodiments, the average functionality of the polyol is from 2 to 3.

[0042] In some embodiments, the number average molecular weight of the polyol is 200-7000 g / mol, preferably 400-6000 g / mol. For example, the polyol has a number average molecular weight of 400 g / mol, 500 g / mol, 600 g / mol, 700 g / mol, 800 g / mol, 900 g / mol, 1000 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol.

[0043] Examples of suitable commercially available polyols include 2095 (from BASF), 4003 / 1 (from BASF), 2090 (from BASF), 3505 / 1 (from BASF), 3905 (from BASF), 3907 (from BASF), 3909 (from BASF), NJ 360S, NJ330S (from NihgWu), BP 11-S (from Kuodu Chemical).

[0044] Based on the total weight of the polyol component, the total amount of polyol is 5-40wt%, for example, in some embodiments, the total amount of polyol is 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%.

[0045] Isocyanate component

[0046] As mentioned above, the isocyanate component according to the present disclosure includes at least one polyisocyanate.

[0047] Polyisocyanate

[0048] The present disclosure does not limit the type of polyisocyanate, which refers to an organic compound containing two or more active isocyanate groups per molecule, i.e., a functionality of 2 (in this case, polyisocyanates are also referred to as diisocyanates) or greater than 2. Examples of polyisocyanates may include any aliphatic, alicyclic, aromatic aliphatic and aromatic difunctional or polyfunctional isocyanates known in the prior art and any desired mixtures thereof. Polyisocyanates may be monomers, prepolymers and / or polymeric isocyanates.

[0049] Examples of suitable polyisocyanates include, but are not limited to, aromatic isocyanates, aliphatic isocyanates, cycloaliphatic isocyanates, and aromatic aliphatic isocyanates. Examples of suitable polyisocyanates include tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, butylene-1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), cyclohexane-1,4- diisocyanates, 1-methylcyclohexane-2,4- and / or 2,6-diisocyanate and / or dicyclohexylmethane-4,4′-, 2,4′- and 2,2′-diisocyanate, diphenylmethane-2,2′-, 2,4′- and / or 4,4′-diisocyanate (MDI), polymeric MDI, naphthalene-1,5-diisocyanate (NDI), toluene-2,4- and / or 2,6-diisocyanate (TDI), 3,3′-dimethyldiphenyl diisocyanate, 1,2-diphenylethane diisocyanate and / or phenylene diisocyanate and combinations thereof.

[0050] In some preferred embodiments, the polyisocyanates are those having two isocyanate groups. In some preferred embodiments, the polyisocyanates are aromatic isocyanates. Diphenylmethane diisocyanate (MDI) and / or toluene diisocyanate (TDI) are particularly preferred for the present disclosure.

[0051] Further possible polyisocyanates are given, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics Handbook, Volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, Chapters 3.2 and 3.3.2.

[0052] Isocyanate prepolymers can be obtained by reacting the above-mentioned polyisocyanates in excess with polyols, for example, at a temperature of 30-100° C., preferably about 80° C. Preferably, 4,4'-MDI together with oxadiazine-modified MDI and commercially available polyols based on polyesters, such as polyesters derived from adipic acid, or polyethers, such as polyethers derived from ethylene oxide and / or propylene oxide are used to produce the prepolymers used in the present disclosure. Preferably, 4,4'-MDI and polyols derived from ethylene oxide and / or propylene oxide are used to produce the prepolymers used in the present disclosure.

[0053] Polyols for preparing isocyanate prepolymers are known to the person skilled in the art and are described, for example, in “Kunststoffhandbuch [Plastics Handbook], Volume 7, Polyurethane [Polyurethane]”, Carl Hanser Verlag, 3rd edition, 1993, Chapter 3.1.

[0054] Modified polyisocyanates are also commonly used, i.e. products obtained by chemical reaction of organic polyisocyanates having two or more active isocyanate groups per molecule. Particular mention may be made of polyisocyanates containing ester groups, urea groups, biuret groups, allophanate groups, carbodiimide groups, isocyanurate groups, uretdione groups, carbamate groups and / or urethane groups.

[0055] Examples of suitable commercially available polyisocyanate compounds include M20S (from BASF) or MIPS (from BASF), etc.

[0056] Flame retardants

[0057] According to the present disclosure, the isocyanate component further includes at least one phosphate flame retardant F1 that is solid at 25°C. That is, the melting point of the phosphate flame retardant F1 is higher than 25°C, i.e., it is solid at room temperature. In some embodiments, the melting point of the phosphate flame retardant F1 is higher than 30°C, 35°C, 40°C, 50°C, or 60°C, etc.

[0058] The phosphate flame retardant F1 can be dissolved in the isocyanate component after being heated and melted, and will not precipitate or precipitate after being cooled to room temperature. Therefore, the isocyanate component containing the phosphate flame retardant F1 does not form solid precipitation or solid precipitation at room temperature (e.g., 25°C) for at least 10 days, preferably at least 20 days, and more preferably at least 30 days. In some preferred embodiments, the isocyanate flame retardant liquid mixture according to the present disclosure remains as a uniform liquid phase at room temperature for at least 10 days, preferably at least 20 days, and more preferably at least 30 days, i.e., no obvious phase separation occurs (e.g., forming two or more liquid layers, or forming a liquid layer and a solid layer).

[0059] In some embodiments, the melting point of the phosphate flame retardant F1 is below 250°C, preferably below 200°C, and more preferably below 150°C.

[0060] In some embodiments, in addition to the above-mentioned phosphate flame retardant F1, the polyurethane reaction system may optionally further include a liquid flame retardant F2 that is liquid at 25°C. In some embodiments, the polyurethane reaction system includes two or more flame retardants. The flame retardants according to the present disclosure may each be present in one of the polyol component or the isocyanate component, or may be present in both components at the same time.

[0061] According to the present disclosure, the storage-stable isocyanate flame retardant liquid mixture can be obtained by the following steps:

[0062] (1) dissolving the phosphate flame retardant F1; and

[0063] (2) forming a storage-stable liquid mixture comprising the phosphate flame retardant F1, the optional flame retardant F2 and the isocyanate component.

[0064] In some embodiments, the phosphate flame retardant F1 in the above step (1) is dissolved in the isocyanate component. When the isocyanate component also includes a flame retardant F2, in some embodiments, the phosphate flame retardant F1 is first dissolved in the flame retardant F2 and then added to the isocyanate component; in other embodiments, the phosphate flame retardant F1 and the flame retardant F2 are added to the isocyanate component at the same time and then dissolved together. It should be understood that the phosphate flame retardant F1 can also be dissolved in the isocyanate component first, and then the flame retardant F2 is added.

[0065] Accordingly, phosphate flame retardant F1 can be dissolved by: 1) heating phosphate flame retardant F1, 2) simultaneously heating phosphate flame retardant F1 and isocyanate component mixture, 3) simultaneously heating phosphate flame retardant F1 and flame retardant F2, or 4) simultaneously heating phosphate flame retardant F1, flame retardant F2 and isocyanate component mixture.

[0066] In some preferred embodiments, the phosphate flame retardant F1 and the optional flame retardant F2 are added to the isocyanate component and then heated together to dissolve.

[0067] In step (2), the dissolved phosphate flame retardant F1, optional flame retardant F2, and isocyanate component mixture obtained in step (1) are stirred evenly and cooled to room temperature to form a storage-stable liquid mixture containing the phosphate flame retardant F1, optional flame retardant F2 and the isocyanate component.

[0068] As for the heating temperature, in the case of adding only phosphate flame retardant F1, F1 should be heated to its melting point ±10°C, and this temperature should be maintained until it is completely melted or dissolved. In the case of adding phosphate flame retardant F1 and flame retardant F2 at the same time, the heating temperature varies with the type and ratio of the flame retardants, and those skilled in the art should determine it during operation according to the actual formula. In general, it only needs to be heated to an appropriate temperature and stirred until it is completely dissolved or melted. In practice, the operating temperature is usually lower than the melting point of phosphate flame retardant F1, because F1 and F2 can form a low melting point eutectic.

[0069] The present disclosure has no special requirements for stirring rate, stirring time and stirring equipment, and those skilled in the art can determine them in actual operation according to the selected flame retardant and ratio. In general, the present disclosure has no obvious characteristics for stirring rate and stirring time. In some embodiments, the phosphate flame retardant F1 after heating and melting can form a uniform liquid mixture with the isocyanate component by conventional stirring for more than 5 minutes.

[0070] Phosphate flame retardant F1 not only has excellent flame retardancy, but also produces less toxic and corrosive gases than halogen flame retardants. In some preferred embodiments, phosphate flame retardant F1 is preferably a halogen-free / halogen-free phosphate flame retardant.

[0071] In some preferred embodiments, the phosphate flame retardant F1 is an aromatic phosphate, i.e., an aromatic phosphate with a melting point higher than 25°C; more preferably, the aromatic phosphate flame retardant is triaryl phosphate and aromatic bisphosphate or aromatic polyphosphate, i.e., triaryl phosphate and aromatic bisphosphate or aromatic polyphosphate with a melting point higher than 25°C. In some specific embodiments, the phosphate flame retardant F1 is trioctyl phosphite (TOP), triphenyl phosphate (TPP), tri(tert-butylphenyl) phosphate (TBPP), biphenyl diphenyl phosphate (BPDP) or a combination thereof.

[0072] In some embodiments, based on the total weight of the polyurethane reaction system, the content of the phosphate flame retardant F1 is 1.8wt%-30wt% or more, for example, 1.8wt%, 2wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%. In some preferred embodiments, based on the total weight of the isocyanate component, the content of the phosphate flame retardant F1 is 10-25wt%.

[0073] In some embodiments, based on the total weight of the polyurethane reaction system, the total content of the phosphate flame retardant F1 and the flame retardant F2 is 1.8wt%-60wt% or more, for example, 1.8wt%, 2wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%. In some preferred embodiments, based on the total weight of the polyurethane reaction system, the total content of the flame retardant F1 and the flame retardant F2 is 15-30wt%.

[0074] Polyurethane Reaction System II

[0075] According to the present disclosure, another polyurethane reaction system is also provided, comprising:

[0076] (a) a polyol component comprising at least one isocyanate-reactive polyol; and

[0077] (b) an isocyanate component comprising at least one polyisocyanate;

[0078] Characterized in that the polyol component further comprises at least one phosphate flame retardant F1 which is solid at 25°C, and the phosphate flame retardant F1 is dissolved in the polyol component at 25°C.

[0079] and forming a storage-stable polyol flame retardant liquid mixture;

[0080] The polyol component further comprises at least one flame retardant F2 which is liquid at 25° C., or the polyol in the polyol component and the phosphate flame retardant F1 both contain phenyl groups.

[0081] That is, in some embodiments, the polyol component includes at least one phosphate flame retardant F1 that is solid at 25° C. and at least one flame retardant F2 that is liquid at 25° C. It should be understood that the isocyanate component may also include the above phosphate flame retardant F1 (and optionally the above flame retardant F2).

[0082] According to the polyurethane reaction system disclosed herein, the polyol component containing the phosphate flame retardant F1 is a storage-stable polyol flame retardant liquid mixture. That is, by naked eye observation, at room temperature (e.g., 25° C.), no solid precipitation or solid precipitation is formed for at least 10 days, preferably at least 20 days, and more preferably at least 30 days.

[0083] In some preferred embodiments, the polyol flame retardant liquid mixture according to the present disclosure remains in a uniform liquid phase at room temperature for at least 10 days, preferably at least 20 days, and more preferably at least 30 days, i.e., no obvious phase separation occurs (e.g., forming two or more liquid layers, or forming a liquid layer and a solid layer).

[0084] This is very important for the polyurethane reaction system, because the polyol component and the isocyanate component are usually not used immediately after preparation, but need to be transported and stored for a period of time before use. If the phosphate flame retardant F1 precipitates or precipitates from the polyol component, it will block the machine on the one hand, and on the other hand, it will cause the flame retardant properties of the cured polyurethane material to be uneven.

[0085] Isocyanate component

[0086] As mentioned above, the isocyanate component according to the present disclosure includes at least one polyisocyanate.

[0087] Polyisocyanate

[0088] The present disclosure does not limit the type of polyisocyanate, which refers to an organic compound containing two or more active isocyanate groups per molecule, i.e., a functionality of 2 (in this case, polyisocyanates are also referred to as diisocyanates) or greater than 2. Examples of polyisocyanates may include any aliphatic, alicyclic, aromatic aliphatic and aromatic difunctional or polyfunctional isocyanates known in the prior art and any desired mixtures thereof. Polyisocyanates may be monomers, prepolymers and / or polymeric isocyanates.

[0089] Examples of suitable polyisocyanates include, but are not limited to, aromatic isocyanates, aliphatic isocyanates, cycloaliphatic isocyanates, and aromatic aliphatic isocyanates. Examples of suitable polyisocyanates include tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, butylene-1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), cyclohexane-1,4- diisocyanates, 1-methylcyclohexane-2,4- and / or 2,6-diisocyanate and / or dicyclohexylmethane-4,4′-, 2,4′- and 2,2′-diisocyanate, diphenylmethane-2,2′-, 2,4′- and / or 4,4′-diisocyanate (MDI), polymeric MDI, naphthalene-1,5-diisocyanate (NDI), toluene-2,4- and / or 2,6-diisocyanate (TDI), 3,3′-dimethyldiphenyl diisocyanate, 1,2-diphenylethane diisocyanate and / or phenylene diisocyanate and combinations thereof.

[0090] In some preferred embodiments, the polyisocyanates are those having two isocyanate groups. In some preferred embodiments, the polyisocyanates are aromatic isocyanates. Diphenylmethane diisocyanate (MDI) and / or toluene diisocyanate (TDI) are particularly preferred for the present disclosure.

[0091] Further possible polyisocyanates are given, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics Handbook, Volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, Chapters 3.2 and 3.3.2.

[0092] Isocyanate prepolymers can be obtained by reacting the above-mentioned polyisocyanates in excess with polyols, for example, at a temperature of 30-100° C., preferably about 80° C. Preferably, 4,4'-MDI together with oxadiazine-modified MDI and commercially available polyols based on polyesters, such as polyesters derived from adipic acid, or polyethers, such as polyethers derived from ethylene oxide and / or propylene oxide are used to produce the prepolymers used in the present disclosure. Preferably, 4,4'-MDI and polyols derived from ethylene oxide and / or propylene oxide are used to produce the prepolymers used in the present disclosure.

[0093] Polyols for preparing isocyanate prepolymers are known to the person skilled in the art and are described, for example, in “Kunststoffhandbuch [Plastics Handbook], Volume 7, Polyurethane [Polyurethane]”, Carl Hanser Verlag, 3rd edition, 1993, Chapter 3.1.

[0094] Modified polyisocyanates are also commonly used, i.e. products obtained by chemical reaction of organic polyisocyanates having two or more active isocyanate groups per molecule. Particular mention may be made of polyisocyanates containing ester groups, urea groups, biuret groups, allophanate groups, carbodiimide groups, isocyanurate groups, uretdione groups, carbamate groups and / or urethane groups.

[0095] Examples of suitable commercially available polyisocyanate compounds include M20S (from BASF) or MIPS (from BASF), etc.

[0096] Polyol components

[0097] As noted above, the polyol component comprises at least one isocyanate-reactive polyol.

[0098] Polyols

[0099] Examples of suitable polyols include, but are not limited to, polyether polyols, graft polyether polyols, polyester polyols, polyolefin polyols, and mixtures thereof. In some embodiments, the polyol is preferably a polyether polyol containing phenyl groups, ie, an aromatic polyether polyol.

[0100] Polyether polyols are organic compounds containing at least ether and OH groups as functional groups. Polyether polyols are prepared using catalysts, for example from epoxides such as propylene oxide and / or ethylene oxide, or from tetrahydrofuran with hydrogen-active starter compounds such as aliphatic alcohols, phenols, amines, carboxylic acids, water and compounds based on natural substances such as sucrose, sorbitol or mannitol. These may include alkaline catalysts or double metal cyanide catalysts, such as those described in, for example, PCT / EP2005 / 010124, EP 90444 or WO 05 / 090440.

[0101] Polyester polyols are prepared, for example, from aliphatic or aromatic dicarboxylic acids and polyols, polythioether polyols, polyesteramides, hydroxylated polyacetals and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are described, for example, in "Kunststoffhandbuch", volume 7, "Polyurethane", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.

[0102] In some embodiments, the polyol has an average functionality equal to or greater than 2 (i.e., having at least two groups reactive to isocyanate), such as 2, 3, or 4. The polyol may be a dihydric polyol, a trihydric polyol, a tetrahydric polyol, or a higher polyol. In some preferred embodiments, the average functionality of the polyol is from 2 to 3.

[0103] In some embodiments, the number average molecular weight of the polyol is 200-7000 g / mol, preferably 400-6000 g / mol. For example, the polyol has a number average molecular weight of 400 g / mol, 500 g / mol, 600 g / mol, 700 g / mol, 800 g / mol, 900 g / mol, 1000 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol.

[0104] Examples of suitable commercially available polyols include 2095 (from BASF), 4003 / 1 (from BASF), 2090 (from BASF), 3505 / 1 (from BASF), 3905 (from BASF), 3907 (from BASF), 3909 (from BASF), NJ 360S, NJ330S (from NingWu), BP 11-S (from Guodu Chemical).

[0105] Based on the total weight of the polyol component, the total amount of polyol is 5-40wt%, for example, in some embodiments, the total amount of polyol is 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%.

[0106] Flame retardants

[0107] According to the present disclosure, the polyol component includes at least one phosphate flame retardant F1 that is solid at 25°C. That is, the melting point of the phosphate flame retardant F1 is higher than 25°C, i.e., it is solid at room temperature. In some embodiments, the melting point of the phosphate flame retardant F1 is higher than 30°C, 35°C, 40°C, 50°C, or 60°C, etc.

[0108] The phosphate flame retardant F1 can be dissolved in the polyol component after being heated and melted, and will not precipitate or precipitate at room temperature. Therefore, the polyol component containing the phosphate flame retardant F1 does not form solid precipitation or solid precipitation at room temperature (e.g., 25°C) for at least 10 days, preferably at least 20 days, and more preferably at least 30 days. In some preferred embodiments, the polyol flame retardant liquid mixture according to the present disclosure remains as a uniform liquid phase at room temperature for at least 10 days, preferably at least 20 days, and more preferably at least 30 days, i.e., no obvious phase separation occurs (e.g., forming two or more liquid layers, or forming a liquid layer and a solid layer).

[0109] In some embodiments, the melting point of the phosphate flame retardant F1 is below 250°C, preferably below 200°C, and more preferably below 150°C.

[0110] As described above, the polyol component according to the present disclosure further comprises at least one flame retardant F2 which is liquid at 25°C, or the polyol in the polyol component and the phosphate flame retardant F1 both contain phenyl groups (ie, aromatic polyol and aromatic phosphate flame retardant which is solid at 25°C).

[0111] That is, in some embodiments, the polyol component includes at least two flame retardants, namely, at least one phosphate flame retardant F1 and at least one flame retardant F2. In other embodiments, the polyol and phosphate flame retardant F1 in the polyol component both contain phenyl (i.e., aromatic polyol and aromatic phosphate flame retardant that is solid at 25°C), and optionally, flame retardant F2 may also be included.

[0112] In some embodiments, when the polyol component includes both the phosphate flame retardant F1 and the flame retardant F2, the content of the flame retardant F2 accounts for more than 20% of the total flame retardant content (ie, the sum of the contents of the phosphate flame retardant F1 and the flame retardant F2), for example, more than 30%.

[0113] According to the present disclosure, the storage-stable polyol flame retardant liquid mixture can be obtained by the following steps:

[0114] (i-1) dissolving the phosphate flame retardant F1; and

[0115] (i-2) forming a storage-stable liquid mixture comprising the phosphate flame retardant F1, the flame retardant F2 and the polyol component;

[0116] Or you can get it by following the steps below:

[0117] (ii-1) dissolving the phosphate flame retardant F1;

[0118] (ii-2) forming a storage-stable liquid mixture comprising the phosphate ester flame retardant F1, an optional flame retardant F2 and a polyol component, wherein the polyol in the polyol component and the phosphate ester flame retardant F1 both contain phenyl groups.

[0119] When the polyol component includes liquid flame retardant F2, in some embodiments, phosphate flame retardant F1 is first dissolved in liquid flame retardant F2 and then added to the polyol component; in other embodiments, phosphate flame retardant F1 and liquid flame retardant F2 are added to the polyol component at the same time and then dissolved together.

[0120] When the polyol component does not contain the flame retardant F2, the polyol in the polyol component and the phosphate flame retardant F1 both contain phenyl groups, and the phosphate flame retardant F1 is dissolved in the polyol component.

[0121] Accordingly, phosphate flame retardant F1 can be dissolved by: 1) heating phosphate flame retardant F1; 2) simultaneously heating phosphate flame retardant F1 and polyol component; 3) simultaneously heating phosphate flame retardant F1 and flame retardant F2; or 4) simultaneously heating phosphate flame retardant F1, flame retardant F2 and polyol component.

[0122] In some preferred embodiments, the (phenyl-containing) phosphate flame retardant F1 and the optional flame retardant F2 are added to the (phenyl-containing) polyol component and then heated together to dissolve.

[0123] In step (2), the dissolved phosphate flame retardant F1 obtained in step (1) and the polyol flame retardant of the optional flame retardant F2 are mixed and stirred uniformly, and cooled to room temperature to form a storage-stable liquid mixture containing the phosphate flame retardant F1, the optional flame retardant F2 and the polyol component.

[0124] As for the heating temperature, in the case of adding only phosphate flame retardant F1, F1 should be heated to its melting point ± 10°C, and this temperature should be maintained until it is completely melted or dissolved. In the case of adding phosphate flame retardant F1 and flame retardant F2 at the same time, the heating temperature varies with the type and ratio of the flame retardants, and those skilled in the art should determine it in operation according to the actual formula. In general, it only needs to be added to the appropriate temperature and stirred until it is completely dissolved or melted. In practice, the operating temperature is usually lower than the melting point of F1, because F1 and F2 can form a low melting point eutectic.

[0125] The present disclosure has no special requirements for stirring rate, stirring time and stirring equipment, and those skilled in the art can determine them in actual operation according to the selected flame retardant and ratio. In general, the present disclosure has no obvious characteristics for stirring rate and stirring time. In some embodiments, the phosphate flame retardant F1 after heating and melting can form a uniform liquid mixture with the polyol component by conventional stirring for more than 5 minutes.

[0126] Phosphate flame retardant F1 not only has excellent flame retardancy, but also produces less toxic and corrosive gases than halogen flame retardants. In some preferred embodiments, phosphate flame retardant F1 is preferably a halogen-free / halogen-free phosphate flame retardant.

[0127] In some preferred embodiments, the phosphate flame retardant F1 is an aromatic phosphate flame retardant, i.e., an aromatic phosphate with a melting point higher than 25°C; more preferably, the aromatic phosphate flame retardant is a triaryl phosphate and an aromatic polyphosphate (e.g., an aromatic bisphosphate) flame retardant, i.e., a triaryl phosphate and an aromatic polyphosphate with a melting point higher than 25°C. In some specific embodiments, the phosphate flame retardant F1 includes trioctyl phosphite (TOP), triphenyl phosphate (TPP), tri(tert-butylphenyl) phosphate (TBPP), biphenyl diphenyl phosphate (BPDP) or a combination thereof.

[0128] In some embodiments, based on the total weight of the polyurethane reaction system, the content of the phosphate flame retardant F1 is 1.8wt%-30wt% or more, for example, 1.8wt%, 2wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%. In some preferred embodiments, based on the total weight of the polyol component, the content of the phosphate flame retardant F1 is 5-25wt%.

[0129] In some embodiments, based on the total weight of the polyurethane reaction system, the total content of the phosphate flame retardant F1 and the liquid flame retardant F2 is 1.8wt%-60wt% or more, for example, 1.8wt%, 2wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%. In some preferred embodiments, based on the total weight of the polyurethane reaction system, the total content of the phosphate flame retardant F1 and the flame retardant F2 is 15-30wt%.

[0130] It should be understood that the present disclosure also relates to a polyurethane reaction system comprising the storage-stable isocyanate flame retardant liquid mixture and the polyol flame retardant liquid mixture as described above.

[0131] In addition to the above components, any of the above polyurethane reaction systems may also include other components.

[0132] Chain Extender / Crosslinker

[0133] In some embodiments, the polyol component according to the present disclosure further comprises a chain extender and / or a cross-linking agent. The molecular weight of the chain extender / cross-linking agent suitable for the present disclosure is less than 500 g / mol, for example, less than 400 g / mol, less than 300 g / mol, less than 200 g / mol, less than 100 g / mol.

[0134] Chain extenders have two isocyanate-reactive functional groups, such as OH-, -SH or NH 2 Based on the total weight of the first component, the content of the chain extender is 5-30wt%, preferably 10-25wt%, more preferably 10-20wt%.

[0135] Examples of chain extenders include monoethylene glycol (MEG), diethylene glycol (DEG), 1,2-propylene glycol, 1,3-propylene glycol (DPG), 1,4-butanediol (BDO), 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, tetraethylene glycol, dipropylene glycol, cyclohexanediol and aliphatic or aromatic amine-based chain extenders, for example aliphatic or aromatic diamines such as ethylenediamine, triethylenediamine and / or diethyltoluenediamine (DETDA). Other possible low molecular weight chain extenders are mentioned, for example, in "Polyurethane Handbook", Carl Hanser Verlag, 2nd edition, 1994, chapters 3.2 and 3.3.2. In some preferred embodiments, the chain extender is selected from monoethylene glycol (MEG), 1,3-propylene glycol (DPG) and 1,4-butanediol (BDO).

[0136] The crosslinking agent has at least three functional groups reactive to isocyanate. Examples of crosslinking agents include 1,2,4-, 1,3,5-trihydroxycyclohexane, glycerol (GLY), trimethylolpropane (TMP), pentaerythritol, triethanolamine (TEOA), diethanolamine (DEOA) and low molecular weight hydroxyl-containing polyoxyalkylenes based on ethylene oxide and / or 1,2-propylene oxide and the above-mentioned diols and / or triols. Other possible low molecular weight crosslinking agents are mentioned, for example, in "Polyurethane Handbook", Carl Hanser Verlag, 2nd edition, 1994, chapters 3.2 and 3.3.2.

[0137] catalyst

[0138] In some embodiments, the polyurethane reaction system according to the present disclosure further includes a catalyst. The catalyst can accelerate the reaction of the polyol and the isocyanate. Examples of conventional catalysts for preparing polyurethanes include, for example, amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine; tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, N-cyclohexylmorpholine, N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylbutanediamine, N,N,N′,N′-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2-dimethylimidazole, 1-azabicyclo(3,3,0)octane, preferably 1,4-diazabicyclo(2,2,2)octane and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyldiethanolamine and N-ethyldiethanolamine and dimethylethanolamine. Likewise useful are organometallic compounds, preferably organotin compounds, such as tin(II) salts of organic carboxylic acids, for example tin(II) acetate, tin(II) octoate, tin(II) ethylhexanoate, tin(II) laurate; and dialkyltin(IV) salts of organic carboxylic acids, for example dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; and bismuth carboxylates, such as bismuth(III) neodecanoate, bismuth 2-ethylhexanoate and bismuth octoate or mixtures thereof. The organometallic compounds can be used alone or, preferably, in combination with a strongly basic amine.

[0139] In some embodiments, the catalyst is preferably a trimerization catalyst, examples of which include alkali metal carboxylates, alkaline earth metal carboxylates, quaternary ammonium carboxylates, or any combination thereof. Examples of suitable alkali metal carboxylates include, but are not limited to potassium neopentanoate, potassium formate, potassium acetate, potassium propionate, butanoate, potassium pentanoate, potassium hexanoate, potassium neohexanoate, potassium heptanoate, potassium octanoate, potassium neooctanoate, 2-ethylhexanoate, potassium decanoate, butyrate, potassium isobutyrate, potassium nonanoate, potassium stearate, potassium neodecanoate, potassium neoheptanoate, sodium octanoate, lithium stearate, sodium hexanoate, lithium octanoate, etc., or any combination thereof. In another aspect, at least one carboxylate is potassium neopentanoate, potassium acetate, potassium octanoate, 2-ethylhexanoate, or any combination thereof.

[0140] Other components

[0141] The polyol component and / or isocyanate component according to the present disclosure may further contain auxiliary agents and / or additives. Any known auxiliary agents and additive materials for the preparation of polyurethanes can be used here. Suitable examples include surfactants, fillers, mold release agents, dyes, pigments, hydrolysis inhibitors, antifungal, antibacterial substances and stabilizers (preferably resistant to hydrolysis, light, heat or discoloration). Such substances are known and are described, for example, in "Kunststoffhandbuch, Band 7, Polyurethane", Carl Hanser Verlag, 3rd edition, 1993, chapters 3.4.4 and 3.4.6 to 3.4.11.

[0142] According to the present disclosure, the polyol component and the isocyanate component are mixed in a ratio of 100:(30-100), for example, 100:30, 100:40, 100:50, 100:60, 100:70, 100:80, 100:90 or 100:100.

[0143] The viscosity of the polyurethane reaction system of the present invention at 25°C measured according to ASTM D2196-15 is 5000cp.s or less, for example, 5000cp.s, 4000cp.s, 3500cp.s, 3000cp.s, 2500cp.s, 2000cp.s, 1500cp.s, 1000cp.s, 500cp.s. In some preferred embodiments, the viscosity of the polyurethane reaction system of the present invention at 25°C measured according to ASTM D2196-15 is 500-2000cp.s.

[0144] application

[0145] The polyurethane reaction system according to the present disclosure has good flame retardant properties and can maintain long-term stability, and can therefore be widely used in fields requiring higher flame retardant properties, including but not limited to automotive products (such as automotive battery products), construction fields, electronic products and other fields.

[0146] In one example of the present disclosure, the present disclosure provides application of the above-mentioned polyurethane reaction system in potting of automotive battery products, wherein the automotive battery products include battery modules and battery packs.

[0147] Automobile battery products

[0148] In another aspect of the present disclosure, there is also provided an automotive battery product, comprising

[0149] Battery cells potted in polyurethane foam;

[0150] The polyurethane foam is a cured product of the polyurethane reaction system described above.

[0151] In some embodiments, the automotive battery product includes a battery module or a battery pack.

[0152] In some embodiments, the polyurethane foam according to the present disclosure has a flame retardancy of at least V2 level, preferably at least V1 level, and more preferably at least V0 level, measured according to UL94.

[0153] In some embodiments, the polyurethane foam according to the present disclosure has a hardness greater than 50 Shore A (measured according to ISO 7619).

[0154] In some embodiments, the polyurethane foam according to the present disclosure has a density (tested according to ISO 1183) of 170-700 g / L, preferably 300-600 g / L.

[0155] In some embodiments, the polyurethane foam according to the present disclosure has a volume resistivity greater than 1E+12.

[0156] It should be understood that the above are only some exemplary application scenarios of the polyurethane reaction system according to the present disclosure. Those skilled in the art will appreciate that the polyurethane reaction system according to the present disclosure can also be applied to other products requiring flame retardant properties.

[0157] Example

[0158] The present disclosure will now be described with reference to Examples and Comparative Examples, which are not intended to limit the present disclosure.

[0159] I. Materials:

[0160]

[0161] Examples (E1-E11) and Comparative Examples (CE1-3) for Preparing Polyol / Isocyanate Components

[0162] Step 1: First, mix the ingredients except the flame retardant according to Table 1 and Table 2 and stir well.

[0163] The isocyanate components of Examples 1-3 and the polyol components of Examples 6-11 did not contain any flame retardant and therefore required no further treatment.

[0164] The polyol component of Examples 4-5 further comprises a liquid flame retardant TEP, which can be mixed with other ingredients in step 1 to prepare the polyol component.

[0165] Step 2:

[0166] The isocyanate component of Examples 4-5 and 6-11 contains solid phosphate flame retardant F1 (i.e., TPP or TBPP). Accordingly, after adding the solid phosphate flame retardant TPP or TBPP to the isocyanate component mixture obtained in the above step 1, the mixture is heated and maintained at 60° C. (TPP) and 95° C. (TBPP), respectively, and then stirred continuously until the solid phosphate flame retardant TPP or TBPP is completely melted, and then cooled to room temperature to obtain an isocyanate component in the form of a uniform liquid phase.

[0167] The polyol components of Examples 1 and 2 simultaneously contain a solid phosphate flame retardant (ie, TPP) at 25°C and a liquid phosphate flame retardant (ie, TEP) at 25°C. Accordingly, the mixture of flame retardants TPP and TEP is first heated and maintained at 60°C and stirred continuously until TPP is completely melted, and then stirred continuously for 5 minutes to obtain a liquid flame retardant mixture. The liquid flame retardant mixture is then added to the polyol component and / or the isocyanate component, stirred evenly and cooled to room temperature to obtain a polyol component in the form of a uniform liquid phase. The polyol component of Example 3 contains only a solid phosphate flame retardant (ie, TPP) at 25°C, TPP is added to the polyol component, heated and maintained at 60°C and stirred continuously until TPP is completely melted, and then stirred continuously for 5 minutes to obtain a polyol flame retardant liquid mixture.

[0168] Comparative Example 1: Only the polyol component contains a flame retardant, namely, liquid flame retardant TEP, which can be mixed with other ingredients in step 1 to prepare the polyol component.

[0169] Comparative Example 2: Only the polyol component contains a flame retardant, namely, solid flame retardant aluminum hydroxide (powder), which can be mixed with other ingredients in step 1 and then stirred to prepare a polyol component.

[0170] Comparative Example 3, in which only the isocyanate component includes the solid phosphate flame retardant TPP, can be prepared using the same steps as in Example 5 above.

[0171] Preparation of polyurethane reaction mixture

[0172] When used, the prepared polyol component and isocyanate component were fed into a mixing chamber at 150 bar in the mixing ratios shown in Table 1 and Table 2, respectively, and mixed to obtain a polyurethane reaction mixture.

[0173] The content (wt %, based on the total amount of the polyurethane reaction system) of the phosphate flame retardant F1 in the polyurethane reaction system of the embodiments (E1-E11) and the comparative examples (CE1-CE3), the total amount of flame retardant (wt %, based on the total amount of the polyurethane reaction system), and the initial viscosity, reaction stability and storage stability of the polyurethane reaction system are also listed in Tables 1 and 2, respectively.

[0174] Table 1

[0175]

[0176]

[0177] Table 2

[0178]

[0179]

[0180] Storage stability

[0181] As shown in Tables 1 and 2, by visual observation, at 25°C, the polyol component and the isocyanate component prepared according to Examples 1-11 of the present disclosure have no obvious phase separation / caking / solid precipitation / solid precipitation, and can continue to maintain a uniform liquid phase state at 25°C for at least 10 days (E3), or even more than 30 days (E1-E2, E4-E11).

[0182] In contrast, the aluminum hydroxide in Comparative Example 2 was stratified and agglomerated after being stored for 7 days.

[0183] Reaction stability

[0184] As shown in Table 1 and Table 2, at 30°C, the difference in the rising time of Examples 1-11 on the 0th day and the 30th day was within an acceptable range, and the reaction stability was good. The rising time here should be understood as the time from mixing the polyol component and the isocyanate component to the time when the mixture starts to foam, wherein the foaming start time can be judged by observing the volume expansion of the mixture.

[0185] In contrast, the fermentation time of Comparative Example 1 was greatly delayed (changed from 43 seconds to 59 seconds) after storage for 30 days, that is, the reaction stability was poor.

[0186] Preparation Example of Battery Product

[0187] The battery product includes a battery housing and has a size of 150 cm (width)×150 cm (length)×15 cm (height). The battery cell is placed inside the battery housing, that is, on the bottom of the battery housing. The battery product further includes other components. The battery cell and other components divide the internal space of the battery housing into a plurality of receiving cavities.

[0188] The liquid polyurethane reaction mixture prepared according to Examples 1 to 11 and Comparative Examples 1 to 3 was injected into the receiving cavity. The volumes of the liquid polyurethane reaction mixture injected in the Examples and Comparative Examples were the same.

[0189] The battery pack was kept at room temperature (25°C) after injection. The liquid polyurethane reaction mixture foamed freely and gradually solidified into polyurethane foam. The density, volume resistivity and flame retardancy of the polyurethane foam are listed in Table 3.

[0190] Table 3 Density, volume resistivity and flame retardant performance test results

[0191]

[0192] As shown in Table 3 above, the polyurethane foam cured using the polyurethane reaction system according to the present disclosure has a flame retardancy of at least V-2 level as measured by UL 94. In contrast, the flame retardancy of Comparative Examples CE1 and CE3 are both lower than the flame retardancy of V-2 level.

[0193] The above describes the basic principle and exemplary embodiments of the present disclosure. It should be understood by those skilled in the art that the above description is only for the purpose of illustrating the present disclosure, and the present disclosure is not limited by the above embodiments. Without departing from the spirit and scope of the present disclosure, the present disclosure may also have various changes and improvements, and these changes and improvements all fall within the scope of the present disclosure.

Claims

1. A polyurethane reaction system comprising: (a) a polyol component comprising at least one isocyanate-reactive polyol; and (b) an isocyanate component comprising at least one polyisocyanate; Characterized in that the isocyanate component further comprises at least one solid phosphate flame retardant F1 at 25°C, and the phosphate flame retardant F1 is dissolved in the isocyanate component at 25°C to form a storage-stable isocyanate flame retardant liquid mixture.

2. The polyurethane reaction system according to claim 1, characterized in that: The isocyanate component also comprises at least one flame retardant F2 which is liquid at 25°C.

3. The polyurethane reaction system according to claim 1 or 2, characterized in that: The storage-stable isocyanate flame retardant liquid mixture is obtained by the following steps: (1) dissolving the phosphate flame retardant F1; and (2) forming a storage-stable liquid mixture comprising the phosphate flame retardant F1, the optional flame retardant F2 and the isocyanate component.

4. A polyurethane reaction system comprising: (a) a polyol component comprising at least one isocyanate-reactive polyol; and (b) an isocyanate component comprising at least one polyisocyanate; Characterized in that the polyol component further comprises at least one phosphate flame retardant F1 which is solid at 25°C, and the phosphate flame retardant F1 is dissolved in the polyol component at 25°C to form a storage-stable polyol flame retardant liquid mixture; The polyol component further comprises at least one flame retardant F2 which is liquid at 25° C., or the polyol in the polyol component and the phosphate flame retardant F1 both contain phenyl groups.

5. The polyurethane reaction system according to claim 4, characterized in that: The storage-stable polyol flame retardant liquid mixture is obtained by the following steps: (i-1) dissolving the phosphate flame retardant F1; and (i-2) forming a storage-stable liquid mixture comprising the phosphate flame retardant F1, the flame retardant F2 and the polyol component; Or you can get it by following the steps below: (ii-1) dissolving the phosphate flame retardant F1; (ii-2) forming a storage-stable liquid mixture comprising the phosphate ester flame retardant F1, an optional flame retardant F2 and a polyol component, wherein the polyol in the polyol component and the phosphate ester flame retardant F1 both contain phenyl groups.

6. The polyurethane reaction system according to claim 1 or 4, characterized in that: The isocyanate flame retardant liquid mixture or the polyol flame retardant liquid mixture remains in a uniform liquid phase at room temperature for at least 10 days, preferably at least 20 days, and more preferably at least 30 days.

7. The polyurethane reaction system according to claim 1 or 4, characterized in that: The phosphate flame retardant F1 is an aromatic phosphate flame retardant; preferably, the aromatic phosphate flame retardant is a triaryl phosphate flame retardant or an aromatic polyphosphate flame retardant; more preferably, the triaryl phosphate flame retardant is triphenyl phosphate (TPP), tri(tert-butylphenyl) phosphate (TBPP), phenyl biphenyl phosphate or a combination thereof.

8. The polyurethane reaction system according to claim 1 or 4, characterized in that: Based on the total weight of the polyurethane reaction system, the content of the phosphate flame retardant F1 is 1.8-30wt%, preferably 10-25wt%.

9. The polyurethane reaction system according to claim 2 or 4, characterized in that: Based on the total weight of the polyurethane reaction system, the total content of the phosphate flame retardant F1 and the flame retardant F2 is 1.8-60wt%, preferably 15-30wt%.

10. The polyurethane reaction system according to claim 4, characterized in that: When the polyol component includes both the phosphate flame retardant F1 and the flame retardant F2, the flame retardant F2 accounts for more than 20% of the total content of the flame retardant.

11. An automotive battery product, characterized in that: The automotive battery article includes a battery cell potted in polyurethane foam; and The polyurethane foam is a cured product of the polyurethane reaction system described in claims 1 to 10.

12. The automotive battery product according to claim 11, characterized in that: The polyurethane foam has a flame retardancy of at least V2 level, preferably at least V1 level, and more preferably at least V0 level, measured according to UL94.

13. The automotive battery product according to claim 11, characterized in that: The hardness of the polyurethane foam is greater than 50 Shore A.

14. The automotive battery product according to claim 11, characterized in that: The density of the polyurethane foam is 100-700 g / L, preferably 300-600 g / L.

15. The automotive battery product according to claim 11, characterized in that: The volume resistivity of the polyurethane foam is >1E+12.

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