High-temperature-resistant self-whitening polyurethane elastomer for hand handling as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polyurethane elastomers, and particularly relates to a high-temperature-resistant self-whitening polyurethane elastomer for hand handling as well as a preparation method and application thereof. The hand-made high-temperature-resistant self-whitening polyurethane elastomer is composed of a component A and a component B according to the mass ratio of 100: (95-105), and the component A is a curing agent and comprises the following raw materials: polyether polyol 1, polyether polyol 2, an antioxidant and a catalyst; and the component B is an isocyanato-terminated polyurethane prepolymer and is prepared from the following raw materials: polyether polyol 3 and diisocyanate. The high-temperature-resistant self-whitening polyurethane elastomer for the hand office is excellent in mechanical property, good in high-temperature resistance and aging resistance, capable of whitening automatically after reaction and comfortable in hand feeling, the appearance of the product is milky white, color mixing is convenient, and when the high-temperature-resistant self-whitening polyurethane elastomer is applied to hand office manufacturing, the product is resistant to high temperature, good in toughness, not prone to breaking and discoloring and diverse in color change; the invention also provides a preparation method thereof.

Description

Technical Field

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

[0002] As a derivative of popular culture such as animation and games, figures have received widespread attention and love around the world in recent years. They are usually made of various materials and are made through sophisticated design and production processes. In the production of figures, the choice 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 the figures.

[0003] PVC material is widely used in the production of figures due to its good plasticity and rich color expression. However, PVC material is prone to yellowing, deformation, cracking, oil release and other problems after being placed at high temperature and for a long time. Therefore, special attention should be paid during storage and display. Secondly, figures made of PVC material need to be heated and melted before they can be molded, and metal molds (steel molds, copper molds) must be used, which greatly increases the production cost.

[0004] ABS plastic is known for its high strength and drop resistance, and is often used to make joints and weapons of action figures that need to withstand certain external forces. ABS plastic is easy to process, has strong detail expression, and good electroplating performance, making it suitable for expressing details and metal textures. However, ABS plastic has poor toughness and heat resistance, and is easy to soften and deform. Secondly, it has poor weather resistance and is prone to aging and discoloration in sunlight, ultraviolet rays, etc., affecting its appearance and performance.

[0005] In summary, the material selection of the figures has an important impact on their overall quality and expressiveness. PU stands for polyurethane, a polymer material with excellent mechanical properties formed by polyols and polyisocyanates through polycondensation reactions. After curing, its physical properties are stronger than PVC and ABS, and it will not deform easily. It also has the advantages of comfortable hand feel, rich colors, strong durability, anti-aging, wear resistance, and long service life. Secondly, PU materials are highly plastic when making figures. In terms of processing and production, since PU does not need to be heated and melted, silicone molds can be used. Compared with metal molds used for PVC, the mold opening cost is lower and the production is simpler. However, compared with traditional plastics such as PVC and ABS, PU materials are more expensive, harder and more brittle, and figures made of it need to be handled with care when carried.

[0006] Therefore, it is necessary to conduct further research on polyurethane elastomer materials so that they have excellent mechanical properties and aging resistance and can be better used in the production of figures. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant spontaneously whitening polyurethane elastomer for figures. The product has excellent mechanical properties, good high-temperature resistance and aging resistance, spontaneous whitening reaction, and a comfortable hand feel. The product has a milky white appearance and is convenient for color adjustment. It is applied to the production of figures. The product is resistant to high temperatures, has good toughness, is not easy to break or discolor, and 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 figures of the present invention is composed of 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, which includes the following raw materials in parts by weight: 18-47 parts of polyether polyol 3 and 53-82 parts of diisocyanate.

[0009] The polyether polyol 1 is a mixture 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 obtained by chain extension of propylene oxide (PO); the polyether polyols with a functionality of 4, a hydroxyl value of 360-560, and a number average molecular weight of 400-600 are PN-360 and PN-400. , PN-560, preferably PN-560 produced by Guodu Chemical (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).

[0010] The polyether polyol 2 is prepared by chain extension reaction of ethylene oxide (EO) with ethylene glycol as an initiator, with 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.

[0011] 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.

[0012] The diisocyanate is one or more of IPDI, HMDI and HDI.

[0013] The antioxidant is one or more of UV-44, UV-21, UV-02, UV-01, 1039, and 1076.

[0014] The catalyst is one or more of CUCAT-E01, CUCAT-E02, and CUCAT-E05.

[0015] The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (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, raise the temperature to 80-95°C and react for 3-5 hours. 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.

[0016] In the step (3), when component A and component B are uniformly mixed according to the mass ratio, the mixing temperature is maintained at 25-35°C; when poured into the mold for curing and molding, the operating time is 3-5 minutes and the mold opening time is 30-60 minutes.

[0017] The high temperature resistant self-whitening polyurethane elastomer for figures is used to cast it into molds of different shapes for preparing figures. During the preparation, different pigments can be added thereto to prepare colorful figure products. The milky white product base can also be dyed after demoulding.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The high temperature resistant spontaneously whitening polyurethane elastomer for figures of the present invention introduces polyether polyols with different chain extension groups into component A. The different activities of the EO and PO chain extension groups are utilized to make them have obvious differences in activity when reacting with isocyanate groups. The asynchronous curing makes the polyurethane elastomer prepared by the reaction not only have excellent appearance, with an overall milky white color, but also have excellent mechanical properties and a warm feel.

[0019] (2) The high temperature resistant self-whitening polyurethane elastomer for figures of the present invention uses a macromolecular polyether polyol to modify the diisocyanate in component B, so that the free isocyanate in component B increases, the free isocyanate has high activity, and the modified diisocyanate has low activity. The appearance of the product is more likely to turn white after curing. In addition, due to the large number average molecular weight of the polyether polyol, the cured product has good toughness. Secondly, the polyurethane elastomer is prepared with aliphatic diisocyanates, which further improves the product's aging resistance and yellowing resistance, making the product excellent in weather resistance.

[0020] (3) The method for preparing the high-temperature resistant self-whitening polyurethane elastomer for figures 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 into different molds to make figures, which is simple to operate, and the product has a milky white base, which is convenient for color adjustment. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the embodiments and comparative examples. The raw materials used in the embodiments and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used are conventional methods in the art unless otherwise specified. The parts of the raw materials in the embodiments and comparative examples are all parts by mass.

[0022] The raw materials used in the embodiments and comparative examples are described as follows: PN-560: PO chain extension, hydroxyl value 560, functionality 4, number average molecular weight 400, Guodu Chemical (Kunshan) Co., Ltd. P-350: PO chain extension, hydroxyl value 35, functionality 3, number average molecular weight 5000, Shandong Bluestar Dongda Co., Ltd.; PEG700: ethylene glycol as initiator, EO as chain extension, hydroxyl value 160, functionality 2, number average molecular weight 700, Liaoning Aoke Chemical Co., Ltd.; C210: hydroxyl value 112, functionality 2, number average molecular weight 1000, Shandong Yinuowei New Materials Co., Ltd.; C207: hydroxyl value 160, functionality 2, number average molecular weight 700, Shandong Yinuowei New Materials Co., Ltd.; C240: hydroxyl value 28, functionality 2, number average molecular weight 4000, Shandong Yinuowei New Materials Co., Ltd.; C260: hydroxyl value 19, functionality 2, number average molecular weight 6000, Shandong Yinuowei New Materials Co., Ltd.; C280: hydroxyl value 14, functionality 2, number average molecular weight 8000, Shandong Yinuowei New Materials Co., Ltd.; HMDI: 4,4-dicyclohexylmethane diisocyanate, Wanhua Chemical Group Co., Ltd. IPDI: isophorone diisocyanate, Wanhua Chemical Group Co., Ltd.; HDI: Hexamethylene diisocyanate, Wanhua Chemical Group Co., Ltd.; MDI-100: diphenylmethane diisocyanate, Wanhua Chemical Group Co., Ltd.; UV-44, UV-21, UV-01, UV-02, 1076, 1039: BASF SE; CUCAT-E01, CUCAT-E02, CUCAT-E05: Guangzhou Yourun Synthetic Materials Co., Ltd.

[0023] The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (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 parts of catalyst and 0.9-1.5 parts of antioxidant into a four-necked flask, stir evenly, protect with nitrogen, heat to 95-100°C, evacuate to -0.01MPa for dehydration to a moisture content of <0.05wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: Add 53-82 parts of diisocyanate to a four-necked flask, protect with nitrogen, add 18-47 parts of polyether polyol 3, raise the temperature to 80-95°C, keep the temperature for reaction for 3-5 hours, and after the reaction is completed, evacuate to -0.01 MPa for degassing for 1 hour, and cool down to obtain component B with an isocyanate content of 25.8-26.25 wt.%; (3) When using, mix component A and component B in a mass ratio of 100:100 at a mixing temperature of 25-35°C, pour into a preheated mold for curing and molding. The operating time is 3-5 minutes. Open the mold after 30-60 minutes. After opening the mold, vulcanize at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0024] Example 1 The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (1) Preparation of component A: Add 53.8 parts of polyether polyol PN-560, 20 parts of polyether polyol PEG700, 25 parts of polyether polyol P-350, 0.3 parts of catalyst CUCAT-E01, 0.3 parts of antioxidant UV-44, 0.3 parts of antioxidant UV-01, and 0.3 parts of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat to 95°C, evacuate to -0.01 MPa for dehydration to a moisture content of <0.05 wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: 82 parts of HMDI were added to a four-necked flask, and 18 parts of polyether polyol C280 were added under nitrogen protection. The temperature was raised to 80°C and kept for reaction for 3 hours. After the reaction was completed, the flask was evacuated to -0.01 MPa for degassing for 1 hour and cooled to obtain component B with an isocyanate content of 26.1 wt.%; (3) When using, mix component A and component B in a mass ratio of 100:100 at a mixing temperature of 25°C, pour into a preheated mold for curing and molding. The operating time is 3 minutes. Open the mold after 30 minutes. After opening the mold, vulcanize at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0025] Example 2 The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (1) Preparation of component A: Add 51 parts of polyether polyol PN-560, 25 parts of polyether polyol PEG700, 22 parts of polyether polyol P-350, 0.5 parts of catalyst CUCAT-E02, 0.5 parts of antioxidant UV-44, 0.5 parts of antioxidant UV-01, and 0.5 parts of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat to 100°C, vacuum -0.01MPa to dehydrate to a moisture content of <0.05wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: 53 parts of HDI were added to a four-necked flask, and 47 parts of polyether polyol C260 were added under nitrogen protection. The temperature was raised to 85°C and kept for reaction for 3.5 hours. After the reaction was completed, the flask was vacuumed to -0.01 MPa for degassing for 1 hour and cooled to obtain component B with an isocyanate content of 25.8 wt.%; (3) When in use, mix component A and component B in a mass ratio of 100:95 at a mixing temperature of 30°C, pour into a preheated mold for curing and molding. The operating time is 4 minutes. Open the mold after 40 minutes. Vulcanize at room temperature for 7 days after opening the mold to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0026] Example 3 The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (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 parts of catalyst CUCAT-E05, 0.3 parts of antioxidant UV-21, 0.3 parts of antioxidant UV-02, and 0.3 parts of antioxidant 1039 into a four-necked flask, stir evenly, protect with nitrogen, heat to 100°C, vacuum -0.01MPa to dehydrate to a moisture content of <0.05wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: 71 parts of IPDI were added to a four-necked flask, and 29 parts of polyether polyol C240 ​​were added under nitrogen protection. The temperature was raised to 90°C and kept for reaction for 5 hours. After the reaction was completed, the flask was evacuated to -0.01 MPa for degassing for 1 hour, and the temperature was lowered to obtain component B with an isocyanate content of 26.25 wt.%; (3) When using, mix component A and component B in a mass ratio of 100:100 at a mixing temperature of 35°C, pour into a preheated mold for curing and molding. The operating time is 3 minutes. Open the mold after 50 minutes. After opening the mold, vulcanize at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0027] Example 4 The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (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 parts of catalyst CUCAT-E01, 0.2 parts of catalyst CUCAT-E02, 0.3 parts of antioxidant UV-44, 0.3 parts of antioxidant UV-21, 0.3 parts of antioxidant UV-02, 0.3 parts of antioxidant UV-01, and 0.3 parts of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat to 100°C, evacuate to -0.01 MPa for dehydration to a moisture content of <0.05 wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: 53 parts of HMDI and 25 parts of IPDI were added to a four-necked flask, and 15 parts of polyether polyol C240 ​​and 7 parts of polyether polyol C260 were added under nitrogen protection. The temperature was raised to 95°C and kept for reaction for 5 hours. After the reaction was completed, the flask was evacuated to -0.01 MPa for degassing for 1 hour, and the temperature was lowered to obtain component B with an isocyanate content of 26.04 wt.%; (3) When in use, mix component A and component B in a mass ratio of 100:105 at a mixing temperature of 35°C, pour into a preheated mold for curing and molding. The operating time is 5 minutes. Open the mold after 60 minutes. Vulcanize at room temperature for 7 days after opening the mold to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0028] Comparative Example 1 This comparative example is the same as Example 3, except that the polyether polyol C240 ​​in component B is replaced by C210 of the same mass fraction, and the remaining steps are the same as Example 3.

[0029] Comparative Example 2 This comparative example is the same as Example 3, except that the diisocyanate in component B is replaced by MDI-100. After the replacement, the mass fractions of raw materials in component B are: 20.5 parts of C240 ​​and 79.5 parts of MDI-100. The remaining steps are the same as Example 3.

[0030] Comparative Example 3 This comparative example is the same as Example 1, except that the polyether polyol in component A is different. The preparation process of component A is as follows: Preparation of component A: Add 58.8 parts of polyether polyol PN560, 40 parts of polyether polyol P-350, 0.3 parts of catalyst CUCAT-E01, 0.3 parts of antioxidant UV-44, 0.3 parts of antioxidant UV-01, and 0.3 parts of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat to 95°C, vacuum -0.01MPa to dehydrate to a moisture content of <0.05wt.%, cool and seal for storage, and obtain component A; the remaining steps are the same as those in Example 1.

[0031] Comparative Example 4 The method for preparing the high temperature resistant spontaneously whitening polyurethane elastomer for figures comprises the following steps: (1) Preparation of component A: Add 58.8 parts of polyether polyol PN560, 40 parts of polyether polyol P-350, 0.3 parts of catalyst CUCAT-E01, 0.3 parts of antioxidant UV-44, 0.3 parts of antioxidant UV-01, and 0.3 parts of antioxidant 1076 into a four-necked flask, stir evenly, protect with nitrogen, heat to 95°C, evacuate to -0.01 MPa for dehydration to a moisture content of <0.05 wt.%, cool and seal for storage, and obtain component A; (2) Preparation of component B: 78 parts of MDI-100 were added to a four-necked flask, and 22 parts of polyether polyol C280 were added under nitrogen protection. The temperature was raised to 80°C and kept for reaction for 3 hours. After the reaction was completed, the flask was evacuated to -0.01 MPa for degassing for 1 hour, and the temperature was lowered to obtain component B with an isocyanate content of 26 wt.%; (3) When using, mix component A and component B in a mass ratio of 100:100 at a mixing temperature of 25°C, pour into a preheated mold for curing and molding. The operating time is 3 minutes. Open the mold after 30 minutes. After opening the mold, vulcanize at room temperature for 7 days to obtain a high-temperature resistant self-whitening polyurethane elastomer for figurines.

[0032] Comparative Example 5 This comparative example is the same as Example 2, except that PEG700 in component A is replaced by C207 with the same number average molecular weight, and the remaining steps are the same as Example 2.

[0033] Comparative Example 6 Purchase ordinary model products on the market, made of ABS / PVC composite material, purchased from JD.com, the product number is 100125956397.

[0034] Comparative Example 7 Shandong Yinuowei Polyurethane Co., Ltd. currently has 80D products, model DJ1680D-A, DJ1630-B.

[0035] The polyurethane elastomers prepared in each embodiment and comparative example were subjected to performance tests. The 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 determining the 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.

[0036] Table 1 Test results

[0037] It can be seen from Table 1 that: in Example 1, component B uses C280 to synthesize prepolymer, which has the largest number average molecular weight, the most free isocyanate in the synthesized prepolymer, and the polyurethane elastomer prepared therefrom has the whitest appearance and the highest whiteness grade; compared with Example 3 and Example 4, the amount of PEG700 added to component A of Example 3 is larger, and its EO content is higher and its activity is higher. Therefore, the polyurethane elastomer prepared therefrom has a higher whiteness grade.

[0038] Compared with Example 3, the polyether polyol of component B in Comparative Example 1 is replaced with C210, and the isocyanate content is consistent with that in Example 3, both of which are 26.25wt.%. However, due to its low molecular weight, relatively less free isocyanate and high activity, the polyurethane elastomer prepared therefrom is transparent in appearance and not white at all.

[0039] Compared with Example 3, the diisocyanate in component B of Comparative Example 2 was replaced with MDI-100, and the isocyanate content was consistent with that in Example 3, which was 26.25 wt.%, and the polyether polyol was unchanged. Although more free isocyanate made the product look whitish, due to the presence of a large number of easily oxidized benzene rings in the molecular chain of MDI-100, it performed the worst in the yellowing resistance test.

[0040] Compared with Example 1, the B component of Comparative Example 3 is the same, except that the more active polyether polyol PEG700 is not used in the A component, resulting in the appearance of the product not turning completely white after curing. However, the use of C280 in the B component to modify HMDI results in more free isocyanate, and the appearance of the product is semi-transparent, and the whiteness grade is slightly lower.

[0041] Compared with Example 2, the B component of Comparative Example 5 is the same, but the more active polyether polyol PEG700 in component A is replaced with C207 with relatively low activity, so the appearance of the product after curing does not turn completely white, the appearance of the product is semi-transparent, and the whiteness grade is lower.

[0042] Compared with Examples 1-4, the A component and the B component of Comparative Example 4 are different, so its whitening effect and yellowing resistance effect are the worst.

[0043] Comparative Example 6 is a finished figurine purchased from the market, which is made of PVC / ABS composite material, and its high temperature resistance and yellowing resistance are relatively poor.

[0044] Comparative Example 7 is our company's existing 80D product, whose formula system is an ordinary polyether / MDI system, component A is PO chain-extended polyether, and component B is a polyether / ordinary MDI system, which is different from the polyethylene glycol system introduced in the present invention, and its high temperature resistance effect, anti-whitening effect and yellowing resistance effect are quite different.

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, and a number average molecular weight of 400-600 and a polyether polyol having a functionality of 3, a hydroxyl value of 28-55, and a number average molecular weight of 3000-6000; 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, 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, 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.

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