High-temperature resistant self-whitening polyurethane elastomer for figurines, its preparation method and application

Abstract

The present invention belongs to the technical field of polyurethane elastomers, and particularly relates to a high-temperature resistant and self-whitening polyurethane elastomer for figurines, its preparation method and application. The high-temperature resistant and self-whitening polyurethane elastomer for figurines of the present invention is composed of component A and component B in a mass ratio of 100:(95-105). Component A is a curing agent and includes the following raw materials: polyether polyol 1, polyether polyol 2, antioxidant, catalyst; Component B is an isocyanate-terminated polyurethane prepolymer and includes the following raw materials: polyether polyol 3, diisocyanate. The high-temperature resistant and self-whitening polyurethane elastomer for figurines of the present invention has excellent mechanical properties of the product, has good high-temperature resistance, aging resistance, reaction self-whitening, comfortable hand feeling, and the appearance of the product presents milky white, which is convenient for color matching. When it is applied to figurine production, the product has high temperature resistance, good toughness, is not easy to break and discolor, and at the same time has various color changes; the present invention also provides its preparation method.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyurethane elastomers, and particularly relates to a high-temperature resistant and self-whitening polyurethane elastomer for figurines, its preparation method and application. Background Art

[0002] Figurines, as derivatives of popular cultures such as anime and games, have received extensive attention and love globally in recent years. They are usually made of various materials as the main raw materials through fine design and production processes. In figurine production, the selection of materials is crucial. Common materials include PVC (polyvinyl chloride), resin, ABS plastic, etc. These materials have their own characteristics, bringing different textures and expressiveness to figurines.

[0003] PVC material is widely used in figurine production due to its good plasticity and rich color expressiveness. However, PVC material is prone to problems such as yellowing, deformation, cracking, and oil leakage after being placed at high temperature for a long time. Therefore, special attention needs to be paid during storage and display. Secondly, PVC figurines need to be heated and melted before being molded, and metal molds (steel molds, copper molds) must be used, greatly increasing the production cost.

[0004] ABS plastic is known for its high strength and anti-drop performance, and is commonly used to make parts such as joints and weapons of figurines that need to withstand a certain amount of external force. ABS plastic is easy to process, has strong detail expressiveness, and good electroplating performance, suitable for showing details and metallic textures. However, ABS plastic has poor toughness and heat resistance, is easy to soften and deform. Secondly, its weather resistance is poor, and it is easy to age and discolor under environments such as sunlight and ultraviolet rays, affecting its appearance and performance.

[0005] In summary, the material selection of figurines has an important impact on their overall quality and expressiveness. PU, full name polyurethane, is a polymer material formed by the polycondensation reaction of polyols and polyisocyanates and has excellent mechanical properties. After curing, its physical properties are stronger and tougher than those of PVC and ABS, and it will not deform easily. Moreover, it has the advantages of comfortable touch, rich colors, strong durability, anti-aging, wear resistance, and long service life. Secondly, when making figurines with PU material, it has strong plasticity. In terms of processing and production, since PU does not need to be heated and melted, a silicone mold can be used. Compared with the metal molds used for PVC, the mold opening cost is lower and the production is simple. However, compared with traditional plastics such as PVC and ABS, the material price of PU material is relatively expensive, and the texture is hard and brittle. Figurines made of it need to be handled with care when carried.

[0006] Therefore, it is necessary to further study polyurethane elastomer materials to make them have excellent mechanical properties and anti-aging properties, and be better applied in figurine production. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a high-temperature resistant self-whitening polyurethane elastomer for figurines. The product has excellent mechanical properties, good high-temperature resistance, aging resistance, spontaneous whitening during reaction, comfortable hand feeling, and the product appearance presents milky white, which is convenient for color matching. When applied to figurine production, the product has high temperature resistance, good toughness, is not easy to break or discolor, and at the same time has a variety of color changes; the present invention also provides a preparation method thereof.

[0008] The high-temperature resistant self-whitening polyurethane elastomer for figurines according to the present invention is composed of component A and component B in a mass ratio of 100:(95 - 105). Among them, component A is a curing agent, including the following raw materials in parts by mass: 68.8 - 78.8 parts of polyether polyol 1, 20 - 30 parts of polyether polyol 2, 0.9 - 1.5 parts of antioxidant, and 0.3 - 0.5 parts of catalyst;

[0009] Component B is an isocyanate-terminated polyurethane prepolymer, including the following raw materials in parts by mass: 18 - 47 parts of polyether polyol 3, and 53 - 82 parts of diisocyanate.

[0010] The polyether polyol 1 is composed of a polyether polyol with a functionality of 4, a hydroxyl value of 360 - 560, and a number-average molecular weight of 400 - 600 and a polyether polyol with a functionality of 3, a hydroxyl value of 28 - 55, and a number-average molecular weight of 3000 - 6000. Both polyether polyols are prepared by chain extension with propylene oxide (PO); the polyether polyol with a functionality of 4, a hydroxyl value of 360 - 560, and a number-average molecular weight of 400 - 600 is one or more of PN-360, PN-400, and PN-560, preferably PN-560 produced by Guodu Chemical Industry (Kunshan) Co., Ltd.; the polyether polyol with a functionality of 3, a hydroxyl value of 28 - 55, and a number-average molecular weight of 3000 - 6000 is one or more of MN-3050D, P-350, and P-360, preferably P-350 produced by Shandong Bluestar Dongda Co., Ltd. The mass ratio of PN-560 to P-350 in polyether polyol 1 is 1:(0.4 - 0.5).

[0011] The polyether polyol 2 is prepared by a chain extension reaction with ethylene glycol as the initiator and ethylene oxide (EO). It has a functionality of 2, a hydroxyl value of 160 - 280, and a number-average molecular weight of 400 - 700; the polyether polyol 2 is one or more of PEG400, PEG500, PEG600, and PEG700, preferably PEG700 produced by Liaoning Aoke Chemical Co., Ltd.

[0012] The polyether polyol 3 is a polyether polyol with a functionality of 2, a hydroxyl value of 14 - 28, and a number-average molecular weight of 4000 - 8000. The polyether polyol 3 is one or more of C240, C260, and C280.

[0013] The diisocyanate described above is one or more of IPDI, HMDI, and HDI.

[0014] The antioxidant described above is one or more of UV-44, UV-21, UV-02, UV-01, 1039, and 1076.

[0015] The catalyst described above is one or more of CUCAT-E01, CUCAT-E02, and CUCAT-E05.

[0016] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0017] (1) Preparation of component A: Put polyether polyol 1, polyether polyol 2, catalyst, and antioxidant into a reaction vessel, stir evenly, protect with nitrogen, heat up to 95-100 °C, vacuum dehydrate until the water content is <0.05 wt.%, cool down and seal for storage to obtain component A;

[0018] (2) Preparation of component B: Add diisocyanate to a reaction vessel, protect with nitrogen, add polyether polyol 3, heat up to 80-95 °C and react for 3-5 h. After the reaction is completed, vacuum degas, cool down to obtain component B with an isocyanate group content of 25.8-26.25 wt.%;

[0019] (3) During use, mix component A and component B evenly according to the mass ratio, pour them into a mold for curing and forming, and perform room-temperature vulcanization after demolding to obtain the high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0020] In the step (3) described above, when component A and component B are mixed evenly according to the mass ratio, the mixing temperature is maintained at 25-35 °C; when pouring into the mold for curing and forming, the workable time is 3-5 min, and the demolding time is 30-60 min.

[0021] The application of the high-temperature resistant self-whitening polyurethane elastomer for figurines is to pour it into molds with different shapes for preparing figurines. During preparation, different pigments can be added to prepare figurine products with rich colors, or after demolding, dyeing can be carried out on the milky white product substrate.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1)The high-temperature resistant and self-whitening polyurethane elastomer for figurines of the present invention introduces polyether polyols with different chain extension groups into component A. By utilizing the different activities of the EO and PO chain extension groups, when reacting with isocyanate groups, there are significant differences in activity, and the asynchronous curing makes the prepared polyurethane elastomer not only have excellent appearance, presenting a milky white overall, but also have excellent mechanical properties and a gentle touch.

[0024] (2)The high-temperature resistant and self-whitening polyurethane elastomer for figurines of the present invention uses macromolecular polyether polyols to modify diisocyanate in component B, resulting in an increase in free isocyanate groups in component B. The free isocyanate has high activity, while the modified diisocyanate has low activity. After curing, the appearance of the product is more likely to turn white. Moreover, due to the relatively large number-average molecular weight of the polyether polyol, the cured product has good toughness. Secondly, by using aliphatic diisocyanate to prepare polyurethane elastomer in combination, the aging resistance and yellowing resistance of the product are further improved, making the product have excellent weather resistance.

[0025] (3)The preparation method of the high-temperature resistant and self-whitening polyurethane elastomer for figurines of the present invention has a simple process flow, good fluidity of each component, and is convenient for manual pouring. Secondly, the prepared product is poured and applied to different molds to make figurines, with simple operation, and the product has a milky white base, which is convenient for color adjustment. Specific Embodiments

[0026] The present invention will be further described below with reference to examples and comparative examples. The raw materials used in the examples and comparative examples are all conventional commercially available raw materials without special instructions, and the process methods used are all conventional methods in the art. The parts involved in the raw materials in the examples and comparative examples are all parts by mass.

[0027] The raw materials used in the examples and comparative examples are described as follows:

[0028] PN-560: PO chain extension, hydroxyl value 560, functionality 4, number-average molecular weight 400, Guodu Chemical (Kunshan) Co., Ltd.;

[0029] P-350: PO chain extension, hydroxyl value 35, functionality 3, number-average molecular weight 5000, Shandong Bluestar Dongda Co., Ltd.;

[0030] PEG700: Starting agent is ethylene glycol, EO chain extension, hydroxyl value 160, functionality 2, number-average molecular weight 700, Liaoning Aoke Chemical Co., Ltd.;

[0031] C210: Hydroxyl value 112, functionality 2, number-average molecular weight 1000, Shandong Yinuowei New Materials Co., Ltd.;

[0032] C207: hydroxyl value 160, functionality 2, number-average molecular weight 700, Shandong INOV New Materials Co., Ltd.;

[0033] C240: hydroxyl value 28, functionality 2, number-average molecular weight 4000, Shandong INOV New Materials Co., Ltd.;

[0034] C260: hydroxyl value 19, functionality 2, number-average molecular weight 6000, Shandong INOV New Materials Co., Ltd.;

[0035] C280: hydroxyl value 14, functionality 2, number-average molecular weight 8000, Shandong INOV New Materials Co., Ltd.;

[0036] HMDI: 4,4'-dicyclohexylmethane diisocyanate, Wanhua Chemical Group Co., Ltd.;

[0037] IPDI: isophorone diisocyanate, Wanhua Chemical Group Co., Ltd.;

[0038] HDI: hexamethylene diisocyanate, Wanhua Chemical Group Co., Ltd.;

[0039] MDI-100: diphenylmethane diisocyanate, Wanhua Chemical Group Co., Ltd.;

[0040] UV-44, UV-21, UV-01, UV-02, 1076, 1039: BASF SE;

[0041] CUCAT-E01, CUCAT-E02, CUCAT-E05: Guangzhou Yourun Synthetic Materials Co., Ltd.

[0042] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for the figure model comprises the following steps:

[0043] (1) Preparation of component A: Add 68.8 - 78.8 parts of polyether polyol 1, 20 - 30 parts of polyether polyol 2, 0.3 - 0.5 part of catalyst and 0.9 - 1.5 parts of antioxidant into a four-necked flask, stir evenly, protect with nitrogen, heat up to 95 - 100 °C, evacuate to -0.01 MPa to dehydrate until the water content < 0.05 wt.%, cool down and seal for storage to obtain component A;

[0044] (2) Preparation of component B: Add 53 - 82 parts of diisocyanate into a four-necked flask, protect with nitrogen, add 18 - 47 parts of polyether polyol 3, heat up to 80 - 95 °C, keep warm and react for 3 - 5 h. After the reaction is completed, evacuate to -0.01 MPa to defoam for 1 h, cool down to obtain component B with an isocyanate group content of 25.8 - 26.25 wt.%;

[0045] (3) During use, the A component and the B component are mixed evenly at a mass ratio of 100:100, the mixing temperature is 25 - 35°C, poured into a preheated mold for curing and forming, the workable time is 3 - 5 min, demolded after 30 - 60 min, and room temperature vulcanized for 7 days after demolding, thus obtaining the high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0046] Example 1

[0047] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0048] (1) Preparation of the A component: Add 53.8 parts of polyether polyol PN-560, 20 parts of polyether polyol PEG700, 25 parts of polyether polyol P-350, 0.3 part of catalyst CUCAT-E01, 0.3 part of antioxidant UV-44, 0.3 part of antioxidant UV-01, and 0.3 part of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat up to 95°C, evacuate to -0.01 MPa to dehydrate until the water content < 0.05 wt.%, cool down and store in a sealed manner, thus obtaining the A component;

[0049] (2) Preparation of the B component: Add 82 parts of HMDI into a four-necked flask, protect with nitrogen, add 18 parts of polyether polyol C280, heat up to 80°C, keep warm and react for 3 h. After the reaction ends, evacuate to -0.01 MPa to defoam for 1 h, cool down, thus obtaining the B component with an isocyanate group content of 26.1 wt.%;

[0050] (3) During use, the A component and the B component are mixed evenly at a mass ratio of 100:100, the mixing temperature is 25°C, poured into a preheated mold for curing and forming, the workable time is 3 min, demolded after 30 min, and room temperature vulcanized for 7 days after demolding, thus obtaining the high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0051] Example 2

[0052] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0053] (1) Preparation of the A component: Add 51 parts of polyether polyol PN-560, 25 parts of polyether polyol PEG700, 22 parts of polyether polyol P-350, 0.5 part of catalyst CUCAT-E02, 0.5 part of antioxidant UV-44, 0.5 part of antioxidant UV-01, and 0.5 part of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat up to 100°C, evacuate to -0.01 MPa to dehydrate until the water content < 0.05 wt.%, cool down and store in a sealed manner, thus obtaining the A component;

[0054] (2)Preparation of Component B: Add 53 parts of HDI into a four-necked flask, under nitrogen protection, add 47 parts of polyether polyol C260, heat up to 85 °C, keep the temperature for reaction for 3.5 h. After the reaction is completed, evacuate to -0.01 MPa for defoaming for 1 h, and then cool down to obtain Component B with an isocyanate group content of 25.8 wt.%.

[0055] (3)During use, mix Component A and Component B evenly at a mass ratio of 100:95, with a mixing temperature of 30 °C, pour them into a preheated mold for curing and forming. The workable time is 4 min, demold after 40 min, and cure at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0056] Example 3

[0057] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0058] (1)Preparation of Component A: Add 48.8 parts of polyether polyol PN-560, 30 parts of polyether polyol PEG700, 20 parts of polyether polyol P-350, 0.3 part of catalyst CUCAT-E05, 0.3 part of antioxidant UV-21, 0.3 part of antioxidant UV-02, and 0.3 part of antioxidant 1039 into a four-necked flask, stir evenly, under nitrogen protection, heat up to 100 °C, evacuate to -0.01 MPa to dehydrate until the water content < 0.05 wt.%, then cool down and store in a sealed manner to obtain Component A;

[0059] (2)Preparation of Component B: Add 71 parts of IPDI into a four-necked flask, under nitrogen protection, add 29 parts of polyether polyol C240, heat up to 90 °C, keep the temperature for reaction for 5 h. After the reaction is completed, evacuate to -0.01 MPa for defoaming for 1 h, and then cool down to obtain Component B with an isocyanate group content of 26.25 wt.%.

[0060] (3)During use, mix Component A and Component B evenly at a mass ratio of 100:100, with a mixing temperature of 35 °C, pour them into a preheated mold for curing and forming. The workable time is 3 min, demold after 50 min, and cure at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0061] Example 4

[0062] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0063] (1)Preparation of Component A: Add 52.6 parts of polyether polyol PN-560, 20 parts of polyether polyol PEG700, 25 parts of polyether polyol P-350, 0.2 part of catalyst CUCAT-E01, 0.2 part of catalyst CUCAT-E02, 0.3 part of antioxidant UV-44, 0.3 part of antioxidant UV-21, 0.3 part of antioxidant UV-02, 0.3 part of antioxidant UV-01, and 0.3 part of antioxidant 1076 into a four-necked flask. Stir evenly, protect with nitrogen, heat up to 100 °C, evacuate to -0.01 MPa to dehydrate until the water content is <0.05 wt.%, cool down and store in a sealed manner to obtain Component A;

[0064] (2)Preparation of Component B: Add 53 parts of HMDI and 25 parts of IPDI into a four-necked flask, protect with nitrogen, add 15 parts of polyether polyol C240 and 7 parts of polyether polyol C260, heat up to 95 °C, keep the temperature for reaction for 5 h. After the reaction is completed, evacuate to -0.01 MPa to defoam for 1 h, cool down to obtain Component B with an isocyanate group content of 26.04 wt.%;

[0065] (3)During use, mix Component A and Component B evenly according to a mass ratio of 100:105, with a mixing temperature of 35 °C, pour them into a preheated mold for curing and forming. The pot life is 5 min, demold after 60 min, and cure at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0066] Comparative Example 1

[0067] This comparative example is the same as Example 3, except that the polyether polyol C240 in Component B is replaced with the same mass fraction of C210, and the remaining steps are the same as those in Example 3.

[0068] Comparative Example 2

[0069] This comparative example is the same as Example 3, except that the diisocyanate in Component B is replaced with MDI-100. After replacement, the raw material mass fractions in Component B are: 20.5 parts of C240 and 79.5 parts of MDI-100, and the remaining steps are the same as those in Example 3.

[0070] Comparative Example 3

[0071] This comparative example is the same as Example 1, except that the polyether polyols in Component A are different. The preparation process of Component A is as follows:

[0072] Preparation of Component A: Add 58.8 parts of polyether polyol PN560, 40 parts of polyether polyol P-350, 0.3 part of catalyst CUCAT-E01, 0.3 part of antioxidant UV-44, 0.3 part of antioxidant UV-01, and 0.3 part of antioxidant 1076 into a four-necked flask. Stir evenly, protect with nitrogen, heat up to 95 °C, evacuate to -0.01 MPa to dehydrate until the water content is < 0.05 wt.%, cool down and store in a sealed manner to obtain Component A; the remaining steps are the same as those in Example 1.

[0073] Comparative Example 4

[0074] The preparation method of the high-temperature resistant self-whitening polyurethane elastomer for figurines includes the following steps:

[0075] (1) Preparation of Component A: Add 58.8 parts of polyether polyol PN560, 40 parts of polyether polyol P-350, 0.3 part of catalyst CUCAT-E01, 0.3 part of antioxidant UV-44, 0.3 part of antioxidant UV-01, and 0.3 part of antioxidant 1076 into a four-necked flask. Stir evenly, protect with nitrogen, heat up to 95 °C, evacuate to -0.01 MPa to dehydrate until the water content is < 0.05 wt.%, cool down and store in a sealed manner to obtain Component A;

[0076] (2) Preparation of Component B: Add 78 parts of MDI-100 into a four-necked flask, protect with nitrogen, add 22 parts of polyether polyol C280, heat up to 80 °C, keep warm and react for 3 h. After the reaction is completed, evacuate to -0.01 MPa to defoam for 1 h, cool down to obtain Component B with an isocyanate group content of 26 wt.%;

[0077] (3) During use, mix Component A and Component B evenly at a mass ratio of 100:100, the mixing temperature is 25 °C, pour them into a preheated mold for curing and forming. The operable time is 3 min, demold after 30 min, and vulcanize at room temperature for 7 days to obtain the high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0078] Comparative Example 5

[0079] This comparative example is the same as Example 2, the difference is that PEG700 in Component A is replaced with C207 with the same number average molecular weight, and the remaining steps are the same as those in Example 2.

[0080] Comparative Example 6

[0081] Purchase a commercially available ordinary figurine product, the material is an ABS / PVC composite material, purchased from JD.com, and the product number is 100125956397.

[0082] Comparative Example 7

[0083] Shandong Yinuowei Polyurethane Co., Ltd. currently has 80D products with models DJ1680D-A and DJ1630-B.

[0084] The polyurethane elastomers prepared in each example and comparative example were subjected to performance tests. Hardness, tensile strength, and elongation at break were tested according to the methods of GB / T528-2009, GB / T529-1999, and GB / T531-1999; the whiteness grade was tested according to the general method for the determination of whiteness of inorganic chemical products in GB / T23774-2009; the yellowing resistance grade was tested according to GBT23983-2009. The test results are shown in Table 1.

[0085] Table 1 Test Results

[0086]

[0087] It can be seen from Table 1 that in Example 1, the C280 synthetic prepolymer was used in the B component, which had the largest number-average molecular weight, the most free isocyanate in the synthesized prepolymer, and the polyurethane elastomer prepared had the whitest appearance and the highest whiteness grade. Comparing Example 3 and Example 4, in Example 3, a larger amount of PEG700 was added to the A component, with a higher EO content and higher activity. Therefore, the polyurethane elastomer prepared had a higher whiteness grade.

[0088] Compared with Example 3, in Comparative Example 1, the polyether polyol in the B component was replaced with C210, and the isocyanate group content was the same as that in Example 3, both being 26.25 wt.%. However, due to its low molecular weight, relatively less free isocyanate, and high activity, the polyurethane elastomer prepared had a transparent appearance and was completely non-white.

[0089] Compared with Example 3, in Comparative Example 2, the diisocyanate in the B component was replaced with MDI-100, and the isocyanate group content was the same as that in Example 3, both being 26.25 wt.%, and the polyether polyol remained unchanged. Although the relatively large amount of free isocyanate made the product appearance white, due to the presence of a large number of benzene rings in the MDI-100 molecular chain that are easily oxidized, it performed the worst in the yellowing resistance test.

[0090] Compared with Example 1, the B component in Comparative Example 3 was the same. The difference was that in the A component, the more active polyether polyol PEG700 was not used, resulting in the appearance of the cured product not being completely white. However, the use of C280 to modify HMDI in its B component led to a relatively large amount of free isocyanate, and the appearance of the product was semi-transparent with a slightly lower whiteness grade.

[0091] Compared with Example 2, the B component of Comparative Example 5 is the same, but the polyether polyol PEG700 with higher activity in the A component is replaced by C207 with relatively lower activity. Therefore, the appearance of the cured product is not completely white, the appearance of the product is semi-transparent, and the whiteness grade is lower.

[0092] Compared with Examples 1-4, both the A component and the B component of Comparative Example 4 are different. Therefore, its whitening effect and yellowing resistance effect are the worst.

[0093] Comparative Example 6 is a finished figure purchased from the market, and its material is a PVC / ABS composite material, and its high temperature resistance and yellowing resistance are both poor.

[0094] Comparative Example 7 is our company's existing 80D product, and its formulation system is a common polyether / MDI system. The A component is a PO-extended polyether, and the B component is a polyether / ordinary MDI system, which is different from the polyethylene glycol system introduced in the present invention. There are significant differences in its high temperature resistance effect, anti-whitening effect and yellowing resistance effect.

Claims

1. A high temperature resistant self-whitening polyurethane elastomer for figures, characterized in that: The method comprises component A and component B in a mass ratio of 100:(95-105), wherein component A is a curing agent, and comprises the following raw materials in mass parts: 68.8-78.8 parts of polyether polyol 1, 20-30 parts of polyether polyol 2, 0.9-1.5 parts of antioxidant, and 0.3-0.5 parts of catalyst; Component B is an isocyanate-terminated polyurethane prepolymer, comprising the following raw materials in parts by weight: 18-47 parts of polyether polyol 3, 53-82 parts of diisocyanate; The polyether polyol 1 is a mixture of a polyether polyol having a functionality of 4, a hydroxyl value of 360-560 mgKOH / g, and a number average molecular weight of 400-600 formed by chain extension of propylene oxide and a polyether polyol having a functionality of 3, a hydroxyl value of 28-55 mgKOH / g, and a number average molecular weight of 3000-6000 formed by chain extension of propylene oxide; The polyether polyol 2 is prepared by chain extension reaction of ethylene oxide with ethylene glycol as an initiator, with a functionality of 2, a hydroxyl value of 160-280 mgKOH / g, and a number average molecular weight of 400-700; The polyether polyol 3 is a polyether polyol having a functionality of 2, a hydroxyl value of 14-28 mgKOH / g, and a number average molecular weight of 4000-8000; The diisocyanate is one or more of IPDI, HMDI and HDI.

2. The high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 1, characterized in that: The polyether polyol 2 is one or more of PEG400, PEG500, PEG600 and PEG700.

3. The high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 1, characterized in that: The antioxidant is one or more of UV-44, UV-21, UV-02, UV-01, 1039, and 1076.

4. The high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 1, characterized in that: The catalyst is one or more of CUCAT-E01, CUCAT-E02, and CUCAT-E05.

5. The high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 1, characterized in that: The polyether polyol 3 is one or more of C240, C260, and C280.

6. A method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparation of component A: polyether polyol 1, polyether polyol 2, catalyst and antioxidant are placed in a reaction vessel, stirred evenly, protected by nitrogen, heated to 95-100°C, vacuum-dehydrated to a moisture content of <0.05wt.%, cooled, sealed and stored, to obtain component A; (2) Preparation of component B: Add diisocyanate to a reaction vessel, protect with nitrogen, add polyether polyol 3, and heat to react. After the reaction is completed, vacuum degassing and cooling are performed to obtain component B with an isocyanate content of 25.8-26.25 wt.%; (3) When using, mix component A and component B evenly according to the mass ratio, pour them into the mold for curing and forming, and vulcanize at room temperature after opening the mold to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

7. The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 6, characterized in that: In the step (2), the temperature is raised to 80-95°C and the reaction time is 3-5h.

8. The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 6, characterized in that: In the step (3), when component A and component B are mixed uniformly according to the mass ratio, the mixing temperature is maintained at 25-35°C.

9. The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures according to claim 6, characterized in that: In the step (3), when pouring into the mold for curing and forming, the operating time is 3-5 minutes and the mold opening time is 30-60 minutes.

10. An application of the high temperature resistant spontaneously whitening polyurethane elastomer for figures according to any one of claims 1 to 5, characterized in that: It is poured into molds of different shapes to make figures.

Images