Polyurethane foam as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to polyurethane foam as well as a preparation method and application thereof. According to the polyurethane foam provided by the invention, a specific amount of the polyether polyol initiated by the amine containing the terminal secondary amine group or the amine containing the terminal tertiary amine group is introduced into the polyether polyol, so that the use of a catalyst is omitted, the hidden dangers of VOC (Volatile Organic Compounds) and odor are fundamentally solved, and the polyurethane foam prepared by adopting the high-activity polyether polyol has the advantages that the service life of the polyurethane foam is prolonged; according to the present invention, the material has characteristics of excellent VOC, excellent odor performance, excellent damp-heat aging resistance, low density and rapid curing, can ensure the normal production process efficiency without using the catalyst during the preparation process, is suitable for the production process requirements of automobile parts, household parts and other parts, and can improve the health and the comfort of the terminal user.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a polyurethane foam and a preparation method and application thereof. Background Art

[0002] Polyurethane foam is widely used in vehicles such as automobiles, high-speed trains, and airplanes due to its superior physical properties and processing flexibility. It is usually used to prepare interior parts such as automotive carpets, front panels, seats, coat racks, and home mattresses. In recent years, both automotive and home manufacturers have made more stringent demands on their foam suppliers, especially the standards for the volatile organic compound (VOC) content, odor, and resistance to moisture and heat aging of polyurethane foam.

[0003] VOC has olfactory irritation and certain toxicity, mainly including aldehydes, amines, benzene compounds, and low molecular alcohols. VOC and odor mainly come from small and medium molecular alcohols such as catalysts, polyethers, and silicone oils, among which catalysts and polyethers dominate. Therefore, to reduce the VOC content in polyurethane materials, it is necessary to select or transform the raw materials for polyurethane foaming in order to effectively reduce the presence of volatile organic compounds. For example, existing patent documents disclose a low-VOC hydrolysis-resistant polyurethane foam and a preparation method thereof, which includes the selection and compounding of a variety of polyether polyols to achieve the effect of low VOC, but the introduction of amine catalysts still has hidden dangers of odor and VOC sources. The prior art also discloses the use of a combination of deodorants to obtain low-odor polyurethane foam, but this does not fundamentally reduce VOC. In addition, the resistance to wet heat aging of polyurethane foam in the prior art also needs to be further improved.

[0004] In view of this, it is urgent to develop a polyurethane foam that can fundamentally reduce the VOC and odor of the polyurethane foam and improve the moisture and heat aging resistance of the polyurethane foam. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defects in the prior art that the VOC and odor of polyurethane foam cannot be fundamentally reduced, and the resistance to moisture and heat aging performance needs to be further improved, so as to provide a polyurethane foam and its preparation method and application.

[0006] To this end, this application provides the following technical solutions:

[0007] According to one aspect of the present application, a polyurethane foam is provided, wherein the raw materials include component A and component B, wherein component A is an isocyanate reactive component, and component B is an isocyanate component.

[0008] Wherein, the component A comprises the following components in parts by weight:

[0009]

[0010] The polyether polyol comprises 50-100 parts of a polyether polyol initiated by a first initiator (polyether polyol A1, i.e., a highly active polyether polyol), and comprises 50%-100% of an amine containing a terminal tertiary amine group and / or an amine containing a terminal secondary amine group, based on the total molar amount of the first initiator.

[0011] In some optional embodiments, the amine containing a terminal secondary amine group or the amine containing a terminal tertiary amine group has any of the following structures:

[0012]

[0013]

[0014] Among them, R1, R2, R3, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 and R 13 R1, R2, R3, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 and R 13 Independently selected from at least one of -CH2-, -CH2CH2-, -CH2CH2CH2-, and -CH2CH2CH2CH2-; R4 is selected from one of -CH3, -CH2CH3, -CH2CH2CH3, and -CH2CH2CH2CH3.

[0015] The amine containing a terminal secondary amine group or the amine structure containing a terminal tertiary amine group contains a tertiary amine group / secondary amine group at one end. The N atom in the amine group, after being used as an initiator and ring-opening polymerization with a polymerization monomer, forms a polyether polyol containing a tertiary amine group. The steric hindrance of the N atom in the tertiary amine group is small, and the high activity of its lone pair of electrons is maintained. This characteristic of the amine group in its structure can be used to achieve a catalytic reaction in polyurethane.

[0016] In some optional embodiments, the hydroxyl value of the polyether polyol initiated by the first initiator is 22-56 mgKOH / g, preferably 28-35 mgKOH / g; the primary hydroxyl content is ≥65%, preferably ≥80%.

[0017] In the present application, the polyether polyol initiated by an amine containing a terminal secondary amine group or an amine containing a terminal tertiary amine group can be prepared by self-production, and the preparation method is conventional in the field. For example, ring-opening polymerization is performed by using ethylene oxide, propylene oxide and butylene oxide, preferably ethylene oxide and propylene oxide, and the reaction molar ratio of the initiator to ethylene oxide and propylene oxide is 1:m:n, wherein m and n are selected from integers of 0 to 200, and the ethylene oxide content in the polyether polyol is preferably 20 to 40%. Typically, but not limiting, the preparation method may include the following steps:

[0018] S1: Add the first initiator (amine containing terminal secondary amine group or terminal tertiary amine group, and may also contain conventional initiator) and catalyst into the reaction kettle, increase the temperature, introduce the epoxy compound, and perform aging reaction;

[0019] S2: Adjust the temperature, introduce the epoxy compound, and continue the reaction;

[0020] S3: The material is transferred to a refining kettle, and acid and water are added for neutralization, dehydration and filtration are performed to obtain the target polyether polyol.

[0021] In some optional embodiments, the catalyst in S1 is an alkali metal catalyst and / or an organic base, a phosphazene catalyst or other common catalysts in the art, preferably one or more of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, metallic sodium, and a phosphazene catalyst; the epoxide in S1 is one or at least two of ethylene oxide, propylene oxide, and butylene oxide, preferably propylene oxide and ethylene oxide;

[0022] and / or, the temperature in S1 is 85-120° C. and the pressure is lower than 0.5 MPaG;

[0023] And / or, propylene oxide is introduced into S1, and the propylene oxide addition cycle is 5 to 10 hours;

[0024] And / or, the aging reaction time in S1 is 0.5 to 2 hours.

[0025] In some optional embodiments, S2 adjusts the temperature to 110-130° C. and the pressure to less than 0.5 MPaG;

[0026] And / or, S2 adds ethylene oxide, and the ethylene oxide addition cycle is 1 to 3 hours;

[0027] And / or, S2 continues to react for 0.5 to 2 hours.

[0028] In some optional embodiments, the acid in S3 is one or more of phosphoric acid, sulfuric acid, acetic acid, and hydrochloric acid, preferably phosphoric acid and / or hydrochloric acid;

[0029] Preferably, the neutralization step in S3 adjusts the pH to 4-7;

[0030] And / or, the dehydrating reduces the moisture to <500 ppm.

[0031] In some optional embodiments, the first initiator further comprises 0-50% of a conventional initiator; as an example, the content of the conventional initiator in the first initiator is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or within the range of any of the above values;

[0032] And / or, the polyether polyol also includes 0 to 50 parts of polyether polyol initiated by a conventional initiator; as an example, the amount of polyether polyol initiated by a conventional initiator in the polyether polyol can be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, or within the range of any of the above values.

[0033] In some optional embodiments, the conventional initiator includes at least one of, including but not limited to, an olamine, a polyamine, and a polyol. It is understood that when the conventional initiator includes multiple initiators, it can be a mixture of initiators of the same type (e.g., a mixture of different olamines, a mixture of different polyamines, a mixture of different polyols, etc.), or a mixture of initiators of different types (e.g., a mixture of an olamine and a polyamine, a mixture of a polyamine and a polyol, etc.).

[0034] In some optional embodiments, the alcoholamine includes but is not limited to at least one of diethanolamine (DEA), triethanolamine (TEA), diisopropanolamine (DIPA) and methyldiethanolamine (MDEA);

[0035] And / or, the polyamine includes at least one of aliphatic or aromatic amines containing more than 2 N atoms and having an active hydrogen content of ≥2 in each molecule, for example, the polyamine includes but is not limited to at least one of ethylenediamine, propylenediamine, diethylenetriamine, metaphenylenediamine, metaphenylenediamine, diaminotoluene, 4,4'-methylenebis(2-chloroaniline), etc.;

[0036] And / or, the polyol includes but is not limited to at least one of ethylene glycol, glycerol, trimethylolpropane, tetrapentaerythritol or sucrose.

[0037] In some optional embodiments, the NCO content in the component B is 18% to 35%, preferably 22 to 32%.

[0038] In some optional embodiments, the mass ratio of component A to component B is 100:30-70, preferably 100:45-65.

[0039] The initiator in the polyether polyol (polyether polyol A2) initiated by the conventional initiator may be an alcohol amine, a polyamine or a polyol with a functionality of 3 and / or 4 and / or 5; the average functionality of the polyether polyol A2 is 3 to 5, the hydroxyl value is 24 to 42 mgKOH / g, the ethylene oxide content is 20 to 40%, based on the weight of the polyether polyol A2, the primary hydroxyl content is greater than or equal to 80%, calculated based on the amount of primary hydroxyl groups and secondary hydroxyl groups;

[0040] In some optional embodiments, the mass fraction of the surfactant is 0.2 to 1.5, preferably 0.3 to 1.0; the surfactant can be obtained by preparation or commercially available. The preparation method can be carried out according to the method commonly used by those skilled in the art; examples of surfactants obtained from commercial sources include but are not limited to M-8818LO, M-8805, M-7734LF2, M7771LF2 of Jiangsu Meside Chemical Co., Ltd., B8870, B8002, B8715, B8734LF2 of Evonik Industries, HR-8870, HR8871 of Dow Chemical, etc. The surfactants can be used alone or in combination.

[0041] In some optional embodiments, the mass fraction of the foaming agent is 3 to 6, preferably 3.5 to 4.5; the foaming agent that can be used includes chemical foaming agents and / or physical foaming agents, examples of which include but are not limited to water, CO2, alkane foaming agents, chlorine-containing or fluorine-containing foaming agents, etc. Examples of the alkane foaming agent are butane, n-pentane, cyclopentane, isopentane, etc., and examples of the fluorine-containing or chlorine-containing foaming agent are 1,2-dichlorofluoroethane, pentafluoropropane, pentafluorobutane, dichloromethane, etc.

[0042] As a preferred technical solution of the present application, the foaming agent is selected from one or more of water, CO2, 1,2-dichlorofluoroethane, butane, n-pentane, cyclopentane and isopentane, preferably water.

[0043] In some optional embodiments, the mass fraction of the cross-linking agent is 0.2 to 1.5, preferably 0.3 to 0.8; the cross-linking agent that can be used is at least one of ethanolamine, diethanolamine, triethanolamine, ethylenediamine, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexanediol, cyclohexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, glycerol, trimethylolpropane or pentaerythritol, preferably one or two of diethanolamine and triethanolamine.

[0044] In some optional embodiments, the component B can be selected from any known isocyanate, modified isocyanate, and isocyanate prepolymer.

[0045] As a preferred technical solution of the present application, the isocyanate component of component B includes polyphenylmethane polyisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate and polyol-modified isocyanate prepolymer, preferably a mixture of polyphenylmethane polyisocyanate, 4,4-diphenylmethane diisocyanate and polyol-modified isocyanate prepolymer, and the NCO content is 18-35%, preferably 22-32%.

[0046] The polyphenylmethane polyisocyanate described in the present application refers to a mixture of polyphenylmethane polyisocyanates having a functionality greater than or equal to 3.

[0047] According to another aspect of the present application, there is provided a method for preparing the above-mentioned polyurethane foam, comprising the following steps:

[0048] Component A and component B are mixed and foamed to obtain the polyurethane foam.

[0049] In some optional embodiments, the mixing temperature is 20 to 40°C, preferably fully mixed at 22 to 35°C;

[0050] And / or, the foaming temperature is 50-80° C., and the foaming time is 60-100 s.

[0051] Specifically, the preparation method of the polyurethane foam comprises: fully mixing component A and component B at 20-40°C, preferably 22-35°C, and then rapidly injecting them into a mold at a mold temperature of 50-80°C for foaming, and opening the mold after 60-120 seconds to obtain the polyurethane foam.

[0052] In the preparation steps described in this application, specific preparation parameters and processes and other conditions that are not described in detail may adopt the preparation parameters and processes commonly used by those skilled in the art.

[0053] The molded density of the polyurethane foam prepared according to the technical solution of this application is 50-80 kg / m 3 , suitable for foaming in molds at 50-80°C, with high production efficiency.

[0054] According to another aspect of the present application, there is provided an application of the polyurethane foam or the polyurethane foam prepared by the preparation method in the field of transportation or home furnishing. For example, the polyurethane foam can be used in the preparation of high-resilience polyurethane soft foams such as automotive parts and home mattresses.

[0055] The polyurethane foam described in the present application has a wide range of uses. As long as the physical properties of the polyurethane foam of the present application, such as density and wet heat compression permanent deformation, meet the requirements of any application field, it can be applied to the corresponding field.

[0056] As a preferred use, the polyurethane foam described in the present application can be used to manufacture automobile and home parts, preferably used to manufacture interior products such as automobile carpets and front panels.

[0057] The technical solution of this application has the following advantages:

[0058] The polyurethane foam provided in the present application can eliminate the use of catalysts by introducing a specific amount of amines containing terminal secondary amine groups or polyether polyols initiated by amines containing terminal tertiary amine groups into polyether polyols, thereby fundamentally solving the hidden dangers of VOC and odor. The polyurethane foam prepared using the highly active polyether polyol has excellent VOC, odor performance and resistance to moisture and heat aging, and has low density and fast maturation characteristics. Although no catalyst is used in the preparation process, normal production process efficiency can still be guaranteed, and it is suitable for the production process requirements of parts such as automobiles and homes, thereby improving the health and comfort of end users.

[0059] The polyurethane foam provided by the present application uses a mixed initiator in the polyether polyol initiated by the first initiator, which ensures that the obtained polyether polyol has high activity while taking into account the control of the synthesis process to obtain a polyether polyol with a narrower molecular weight distribution. The mixed initiator can effectively adjust and control the functionality, thereby having better adaptability in the application field of polyurethane foam and further reducing the VOC content and odor level. DETAILED DESCRIPTION

[0060] The following examples are provided for a better understanding of the present application, but are not limited to the best implementation mode described, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the protection scope of the present application.

[0061] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0062] The main raw materials used in the examples and comparative examples of the present application are as follows. Other raw materials are common commercially available unless otherwise specified:

[0063] Polyether polyol A1-1, using the compound shown in the following structure 1 as an initiator, propylene oxide and ethylene oxide as polymerization monomers and ethylene oxide end-capping, ethylene oxide content of 20%, primary hydroxyl content of 85%, hydroxyl value of 28 mgKOH / g;

[0064] Structure 1, 3-Dimethylaminopropylamine was purchased from Aladdin; the specific synthesis includes the following steps:

[0065] 1) Add 102.18g (1 mol) of 3-dimethylaminopropylamine and potassium hydroxide equivalent to 0.2% of the total mass of 3-dimethylaminopropylamine, propylene oxide, and ethylene oxide into a self-priming reactor. Seal the reactor and replace it with nitrogen three times. When the reactor is heated to 65°C, evacuate the reactor for 1 hour. Heat the reactor to 110°C and control the pressure below 0.5MPa. Add 3370g of propylene oxide. Add the materials after 5 hours. Continue the reaction until the pressure no longer decreases.

[0066] 2) Control the pressure below 0.4 MPa and add 750 g of ethylene oxide. Add the mixture over 2 h and continue the reaction until the pressure no longer decreases;

[0067] 3) Cool to 75-80℃ to remove the monomer for 1 hour, add appropriate amount of hydrochloric acid to the product to neutralize the pH to about 7, remove water and unreacted hydrochloric acid, and discharge the product. Determine the hydroxyl value and trialdehyde content of the product.

[0068] Polyether polyol A1-2, starting from the compound shown in structure 1 and diethylenetriamine, propylene oxide and ethylene oxide are polymerization monomers and ethylene oxide is terminated, the ethylene oxide content is 30%, the primary hydroxyl content is 89%, and the hydroxyl value is 34 mgKOH / g;

[0069] Diethylenetriamine was purchased from Aladdin; the specific synthesis includes the following steps:

[0070] 1) Add 61.3g (0.6mol) 3-dimethylaminopropylamine, 41.27g (0.4mol) diethylenetriamine and 0.05% of the total mass of 3-dimethylaminopropylamine, diethylenetriamine, propylene oxide and ethylene oxide to a self-priming reactor, with a phosphazene:potassium hydroxide mass ratio of 1:1. Close the reactor and replace it with nitrogen three times. Vacuum the reactor until it is heated to 70°C for 1h. Heat the reactor to 110°C and control the pressure below 0.4MPa. Add 3650g propylene oxide. Add the materials after 5h, and continue the reaction until the pressure no longer decreases.

[0071] 2) Control the pressure below 0.3 MPa and add 1560 g of ethylene oxide. Add the mixture over 2 h and continue the reaction until the pressure stops decreasing.

[0072] 3) Cool to 75-80℃ to remove the monomer for 1 hour, add appropriate amount of hydrochloric acid to the product to neutralize the pH to about 7, remove water and unreacted hydrochloric acid, and discharge the product. Determine the hydroxyl value and trialdehyde content of the product.

[0073] Polyether polyol A1-3, using the compound shown in structure 2 as an initiator, propylene oxide and ethylene oxide as polymerization monomers and ethylene oxide end-capping, ethylene oxide content of 20%, primary hydroxyl content of 87%, hydroxyl value of 35 mgKOH / g;

[0074] Structure 2, N,N-dimethyldipropylenetriamine was purchased from Aladdin; the specific synthesis includes the following steps:

[0075] 1) Add 159.3g (1mol) of N,N-dimethyldipropylenetriamine and 0.05% of the total mass of N,N-dimethyldipropylenetriamine, propylene oxide and ethylene oxide to a self-priming reactor, with a phosphazene composite catalyst composition of 2:1 mass ratio of phosphazene to potassium hydroxide. Close the reactor and replace it with nitrogen three times. Vacuum the reactor until it is heated to 90°C for 1h. Heat the reactor to 120°C and control the pressure below 0.4MPa. Add 3850g of propylene oxide. Add the materials after 5h, and continue the reaction until the pressure no longer decreases.

[0076] 2) Control the pressure below 0.3 MPa and add 960 g of ethylene oxide. The addition should be completed within 2 hours and the reaction should continue until the pressure no longer decreases.

[0077] 3) Cool to 75-80℃ to remove the monomer for 1 hour, add appropriate amount of hydrochloric acid to the product to neutralize the pH to about 7, remove water and unreacted hydrochloric acid, and discharge the product. Determine the hydroxyl value and trialdehyde content of the product.

[0078] Polyether polyol A1-4, with the compound shown in structure 3 and triethylenediamine as mixed initiators, propylene oxide and ethylene oxide as polymerization monomers and ethylene oxide end-capping, ethylene oxide content of 18%, primary hydroxyl content of 84%, hydroxyl value of 36 mgKOH / g;

[0079] Structure 3 is N-Methylethylenediamine was purchased from Aladdin; the specific synthesis steps are as follows:

[0080] 1) Add 59.3g (0.8mol) of N-methylethylenediamine, 20.6g (0.2mol) of diethylenetriamine and 0.05% of the total mass of N-methylethylenediamine, diethylenetriamine, propylene oxide and ethylene oxide to a self-priming reactor. The composition is a phosphazene:potassium hydroxide mass ratio of 2:1. Close the reactor and replace it with nitrogen three times. Wait for the reactor to be heated to 90℃ and evacuate for 1h. Heat the reactor to 120℃ and control the pressure below 0.4MPa. Add 4230g of propylene oxide. Add the materials after 5h. Continue the reaction until the pressure no longer decreases.

[0081] 2) Control the pressure below 0.3 MPa and add 880 g of ethylene oxide. The addition should be completed within 2 hours and the reaction should continue until the pressure no longer decreases.

[0082] 3) Cool to 75-80℃ to remove the monomer for 1 hour, add appropriate amount of hydrochloric acid to the product to neutralize the pH to about 7, remove water and unreacted hydrochloric acid, and discharge the product. Determine the hydroxyl value and trialdehyde content of the product.

[0083] Polyether polyol A2-1, starting with glycerol, with propylene oxide and ethylene oxide as polymerization monomers and ethylene oxide end-capping, ethylene oxide content of 23%, primary hydroxyl content of 85%, and hydroxyl value of 28 mgKOH / g.

[0084] Polyether polyol A2-2, trimethylolpropane is used as the starting material, propylene oxide and ethylene oxide are used as polymerization monomers and ethylene oxide is used as the terminal end capping material, the ethylene oxide content is 25%, the primary hydroxyl content is 88%, and the hydroxyl value is 35 mgKOH / g.

[0085] Polyether polyol A2-3, starting with triethanolamine, with propylene oxide and ethylene oxide as polymerization monomers and ethylene oxide end-capping, ethylene oxide content of 23%, primary hydroxyl content of 87%, hydroxyl value of 33 mgKOH / g;

[0086] The polyether polyol A2-4 is initiated by triethylenediamine, and propylene oxide and ethylene oxide are polymerization monomers and ethylene oxide is terminated. The ethylene oxide content is 21%, the primary hydroxyl content is 86%, and the hydroxyl value is 36 mgKOH / g.

[0087] Surfactant, Evonik B8734LF2.

[0088] Cross-linking agent 1: triethanolamine;

[0089] Cross-linker 2: diethanolamine.

[0090] Isocyanate B1, a mixture of polyphenylmethane polyisocyanate, 4,4-diphenylmethane diisocyanate and polyol-modified isocyanate prepolymer, NCO content 30%;

[0091] Isocyanate B2, a mixture of polyphenylmethane polyisocyanate, 4,4-diphenylmethane diisocyanate and polyol-modified isocyanate prepolymer, NCO content 22%;

[0092] Isocyanate B3, a mixture of polyphenylmethane polyisocyanate, 4,4-diphenylmethane diisocyanate and polyol-modified isocyanate prepolymer, NCO content 32%.

[0093] Catalyst 1: Huntsman, dimethylaminopropylamine;

[0094] Catalyst 2: Huntsman, N,N-dimethyl-N,N-bis(2-hydroxypropyl)-1,3-propylenediamine (CAS No. 63469-23-8).

[0095] Example 1

[0096] This embodiment provides a polyurethane foam, and the preparation method thereof comprises the following steps:

[0097] According to the proportion in Table 1: the measured raw materials of component A are uniformly mixed at 25°C, then fully mixed with the measured component B at 25°C and injected into a mold at a mold temperature of 65°C for reaction foaming. After 120 seconds, the mold is opened and the foam is taken out (the gel time needs to be less than 70 seconds) to obtain a polyurethane foam.

[0098] Performance Test:

[0099] The standard used for testing density is ISO845;

[0100] Odor and VOC evaluation standards: BMW cubic warehouse test method, GS97014-3:2022 (VOC) GS97014-4:2021 (Odour);

[0101] Wet heat aging test: place the foam in a constant temperature and humidity aging box at 60°C and 90% RH for 240 hours, refer to the standard: GB / T10802-2023 to test the compression permanent deformation;

[0102] Rising time: visual method, after component A and component B are mixed under the set material temperature and ambient temperature conditions, the time when the liquid material turns milky white and starts to foam and rise;

[0103] Gel time: visual method, after component A and component B are mixed under the set material temperature and ambient temperature conditions, the foam begins to form a strength that can resist slight external pressure and has a relatively stable three-dimensional structure. Gel time is also called wire drawing time. Common test methods: from the time the foaming material is mixed to the time when a bamboo stick is inserted into the foam 1 cm deep, and the first filament appears.

[0104] The raw materials of each component in Table 1 are calculated by weight.

[0105] Embodiment 2-9

[0106] This embodiment provides a polyurethane foam, and its preparation method is the same as that of Embodiment 1. The specific composition of the raw materials is shown in Table 1.

[0107] Comparative Examples 1-4

[0108] This comparative example provides a polyurethane foam, and its preparation method is the same as that of Example 1. The specific composition of the raw materials is shown in Table 2.

[0109] In the following Tables 1 and 2, “ / ” represents that the corresponding component was not added or the relevant performance test was not performed.

[0110] Table 1 Composition and test results of the embodiments

[0111]

[0112]

[0113] Table 2 Composition and test results of comparative examples

[0114]

[0115]

[0116] From the data in the above table, it can be seen that by using polyether polyols initiated by amines containing terminal secondary amine groups or amines containing terminal tertiary amine groups, the foam can be kept to rise and mature quickly without catalysts, fundamentally solving the hidden dangers of VOC and odor. The prepared polyurethane foam has excellent VOC and odor performance, and has excellent moisture and heat resistance and low density. From the comparison between Example 1 and Example 2, it can be seen that the use of mixed initiators in highly active polyether polyols can further reduce the VOC content and odor level. Among them, the gel time of Comparative Example 1 and Comparative Examples 3-4 is more than 70s, which does not meet the foaming requirements, and no subsequent performance tests were performed.

[0117] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A polyurethane foam, characterized in that The raw materials include component A and component B, wherein component A is an isocyanate reactive component, and component B is an isocyanate component. Wherein, the component A comprises the following components in parts by weight: 100 parts of polyether polyol, 0.2-1.5 parts of surfactant; 3 to 6 parts of foaming agent; 0.2-1.5 parts of cross-linking agent; The polyether polyol comprises 50-100 parts of polyether polyol initiated by a first initiator, and comprises 50%-100% of amines containing terminal tertiary amine groups and / or amines containing terminal secondary amine groups, based on the total molar amount of the first initiator.

2. The polyurethane foam according to claim 1, characterized in that The amine containing a terminal secondary amine group or the amine containing a terminal tertiary amine group has any of the following structures: Among them, R1, R2, R3, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 and R 13 R4 is independently selected from one of the C1-C4 alkyl groups.

3. The polyurethane foam according to claim 1, characterized in that The polyether polyol initiated by the first initiator has a hydroxyl value of 22-56 mgKOH / g and a primary hydroxyl content of ≥65%.

4. The polyurethane foam according to any one of claims 1 to 3, characterized in that The first initiator also includes 0-50% of a conventional initiator.

5. The polyurethane foam according to claim 4, characterized in that The conventional initiator comprises at least one of an alcohol amine, a polyamine, and a polyol; The alcohol amine includes at least one of diethanolamine, triethanolamine, diisopropanolamine, and methyldiethanolamine; The polyamine includes at least one of aliphatic or aromatic amines containing more than 2 N atoms and an active hydrogen content of ≥2 in each molecule; The polyol includes at least one of ethylene glycol, glycerol, trimethylolpropane, tetrapentaerythritol or sucrose.

6. The polyurethane foam according to any one of claims 1 to 3 or 5, characterized in that The NCO content of the component B is 18% to 35%.

7. The polyurethane foam according to claim 6, characterized in that The mass ratio of component A to component B is 100:30-70.

8. A method for preparing the polyurethane foam according to any one of claims 1 to 7, characterized in that: The steps include: Component A and component B are mixed and foamed to obtain the polyurethane foam.

9. The method for preparing polyurethane foam according to claim 8, characterized in that: The mixing temperature is 20 to 40°C; And / or, the foaming temperature is 50-80° C., and the foaming time is 60-100 s.

10. Use of the polyurethane foam according to any one of claims 1 to 7 or the polyurethane foam prepared by the preparation method according to claim 8 or 9 in the field of transportation or home furnishing.

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