A polyurethane raw rubber, a compounded polyurethane, and a polyurethane compound molded body.

Abstract

This invention provides a polyurethane raw rubber, a compounded polyurethane, and a polyurethane compounded molded article. The raw materials for preparing the polyurethane raw rubber include a polyester polyol and a polyisocyanate. The polyester polyol is selected from polyester polyols without side chains, and the polyisocyanate is selected from aliphatic symmetrical polyisocyanates. This invention, through the design of the raw materials for preparing the polyurethane raw rubber, obtains a high-performance polyurethane raw rubber using polyester polyols without side chains and aliphatic symmetrical polyisocyanates. Furthermore, it prepares a compounded polyurethane that, while maintaining transparency and resistance to yellowing (A method ≥ 4, B method ≥ 4), has a tear strength ≥ 75 kN / m at a hardness of 65–70 A.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane material technology, specifically relating to a polyurethane raw rubber, a compounded polyurethane, and a polyurethane compound molded body. Background Technology

[0002] Compound polyurethane rubber (MPU) is made by compounding raw rubber synthesized from diols and isocyanates as the main raw materials. Its processing and vulcanization processes are the same as those for general-purpose rubber; it is suitable for producing rubber products with a Shore A hardness range of 50 to 95. Compared to traditional rubber materials, compound polyurethane rubber has significant advantages in wear resistance, oil resistance, and environmental friendliness, making it a new type of green and environmentally friendly material.

[0003] Currently available polyurethane systems typically exhibit a tear strength of less than 60 kN / m at right angles under a hardness of 65–70 A. Tear strength is a key indicator of a polymer material's resistance to damage; the higher the value, the stronger the product's resistance to external forces. Materials with high tear strength are more suitable for products requiring high fatigue and wear resistance, such as shoe soles and speed skating wheels.

[0004] CN110317447A provides a method for preparing a highly transparent, yellowing-resistant compounded polyurethane, which is made from polyether raw rubber. Although the yellowing resistance of this patent is good, its tear strength and abrasion resistance are poor at a hardness of 60-85A.

[0005] CN106432682A discloses a raw rubber prepared using toluene diisocyanate, glyceryl allyl ether, and polyester polyol. Although the Mooney viscosity ML(1+4, 100℃) = 70, due to the asymmetry and side groups of toluene diisocyanate and glyceryl allyl ether, oriented crystallization is difficult to achieve. Therefore, it is inferred that the tear strength of the vulcanized rubber prepared using this raw rubber is unlikely to reach above 75 KN / M when the hardness is 65-70A.

[0006] Therefore, how to provide a compounded polyurethane with high tear strength, especially how to provide a compounded polyurethane with a tear strength ≥75kN / m at a hardness of 65-70A while ensuring transparency and resistance to yellowing (A method ≥4 grade, B method ≥4 grade), has become an urgent technical problem to be solved. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a polyurethane raw rubber, a compounded polyurethane, and a polyurethane compounded molded article. The present invention designs the raw materials for preparing the polyurethane raw rubber, and obtains a high-performance polyurethane raw rubber through the preparation of a non-side-chain polyester polyol and an aliphatic symmetrical polyisocyanate. Furthermore, it prepares a compounded polyurethane that, while ensuring transparency and resistance to yellowing (A method ≥ grade 4, B method ≥ grade 4), has a tear strength ≥ 75 kN / m at a hardness of 65–70 A.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a polyurethane raw rubber, wherein the raw materials for preparing the polyurethane raw rubber include polyester polyol and polyisocyanate.

[0010] The polyester polyol is selected from polyester polyols without side chains;

[0011] The polyisocyanate is selected from aliphatic symmetrical polyisocyanates.

[0012] This invention designs the raw materials for preparing polyurethane raw rubber, and obtains high-performance polyurethane raw rubber by using polyester polyols without side chains and aliphatic symmetrical polyisocyanates. In addition, it prepares a compounded polyurethane that, while ensuring transparency and resistance to yellowing (A method ≥ 4 grade, B method ≥ 4 grade), has a tear strength ≥ 75 kN / m at a hardness of 65-70A.

[0013] In this invention, the polyester polyol without side chains has high regularity and is not easily crystallized at room temperature. However, under external force, it undergoes deformation to induce oriented crystallization. Using polyester polyols with specific structures can improve the tear strength and other mechanical properties of compounded polyurethane. The aliphatic symmetrical polyisocyanate has high structural regularity and is prone to oriented crystallization after being subjected to external force. Using isocyanates with specific structures can improve the tear strength and other mechanical properties of compounded polyurethane. At the same time, the aliphatic symmetrical polyisocyanate does not contain chromogenic groups and will not cause the polyurethane material to yellow.

[0014] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0015] As a preferred embodiment of the present invention, the number average molecular weight of the polyester polyol is 1000-4000 g / mol, for example, it can be 1000 g / mol, 1200 g / mol, 1500 g / mol, 1800 g / mol, 2000 g / mol, 2300 g / mol, 2500 g / mol, 2700 g / mol, 3000 g / mol, 3300 g / mol, 3600 g / mol, 3800 g / mol or 4000 g / mol, etc.

[0016] The polyester polyols selected in this invention, with a number average molecular weight of 1000-4000 g / mol, have good flexibility and are not easily crystallized at room temperature. However, under external force, they undergo deformation to induce orientation crystallization.

[0017] Preferably, the polyester polyol is selected from polyadipate polyols and / or polycaprolactone polyols.

[0018] Preferably, the aliphatic symmetrical polyisocyanate includes hexamethylene diisocyanate and / or dicyclohexylmethane diisocyanate.

[0019] As a preferred embodiment of the present invention, the raw materials for preparing the polyurethane raw rubber also include a chain extender;

[0020] Preferably, based on the mass percentage of the raw materials for preparing the polyurethane raw rubber being 100%, the mass percentage of the chain extender is ≤3%, for example, it can be 0.1%, 0.3%, 0.5%, 0.7%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.7%, or 3%, etc.

[0021] Preferably, the chain extender is selected from small molecule diols that do not have side chains.

[0022] If the amount of chain extender is too large, it will lead to high microphase separation of polyurethane raw rubber, resulting in physical cross-linking and easy crystallization at room temperature. Although polyurethane raw rubber can be normally mixed to prepare polyurethane compounded molded articles at low Mooney viscosity (ML(1+4,100℃)<55), the heat generated during mixing at high Mooney viscosity is much higher than that of traditional rubber, making mixing difficult and easily leading to degradation of polyurethane raw rubber during the mixing process. Chain extenders containing side chains can also easily affect the regularity of polyurethane raw rubber, making it difficult for polyurethane raw rubber to produce oriented crystals after being subjected to external force, thereby affecting the tear strength and other mechanical properties of compounded polyurethane.

[0023] Preferably, the small molecule diol without side chains is selected from any one or a combination of at least two of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol or 1,6-hexanediol.

[0024] Preferably, the raw materials for preparing the polyurethane raw rubber do not contain chain extenders.

[0025] As a preferred embodiment of the present invention, the isocyanate index (R value) of the polyurethane raw rubber is 0.91 to 1 (for example, it can be 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99 or 1, etc.), preferably 0.98 to 0.99 (for example, it can be 0.981, 0.982, 0.983, 0.984, 0.985, 0.986, 0.987, 0.988, 0.989 or 0.99, etc.).

[0026] Preferably, the Mooney viscosity ML (1+4, 100°C) of the polyurethane raw rubber is 65-90 (e.g., it can be 65, 66, 68, 70, 72, 75, 78, 80, 81, 82, 85, 88 or 90, etc.), and more preferably 70-90.

[0027] This invention designs the raw materials for preparing polyurethane raw rubber, using a non-side-chain polyester polyol, an aliphatic symmetrical polyisocyanate, and a small amount of optional non-side-chain chain extender, and utilizes a suitable isocyanate index (R value) to prepare polyurethane raw rubber with a high Mooney viscosity (ML), thereby obtaining a compounded polyurethane with high tear strength and good other mechanical properties.

[0028] It should be noted that this invention does not impose any special limitations on the preparation method of polyurethane raw rubber; commonly used preparation methods in the art are applicable, including but not limited to:

[0029] Polyester polyol, optional chain extender and polyisocyanate are mixed and reacted at 70-100°C (e.g., 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc.) for 2-30 min (e.g., 2 min, 5 min, 7 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 27 min or 30 min, etc.) in the presence of a catalyst, and then baked at 100-130°C (e.g., 100°C, 105°C, 110°C, 115°C, 120°C, 125°C or 130°C, etc.) for 2-30 h (e.g., 3 h, 5 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h, 23 h, 25 h, 27 h or 30 h, etc.) to obtain the polyurethane raw rubber.

[0030] The catalyst includes one or more organometallic catalysts, such as bismuth neodecanoate, tin isooctanoate, and lead isooctanoate; the amount of catalyst added is 20-1000 ppm (e.g., 20 ppm, 50 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, or 1000 ppm, etc.), calculated based on the total mass of the reactants.

[0031] Secondly, the present invention provides a compounded polyurethane, the compounded polyurethane comprising the following components in parts by weight:

[0032] 100 parts of the polyurethane raw rubber as described in the first aspect;

[0033] 15-40 parts of reinforcing agent;

[0034] 0.5-2 parts of coupling agent.

[0035] In this invention, the weight parts of the reinforcing agent in the compounded polyurethane can be 15 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, or 40 parts, etc.

[0036] The weight percentage of the coupling agent in the compounded polyurethane can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2 parts, etc.

[0037] As a preferred embodiment of the present invention, the reinforcing agent includes silica and / or calcium carbonate.

[0038] Preferably, the reinforcing agent in the compounded polyurethane contains 20-30 parts by weight, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 parts.

[0039] Preferably, the coupling agent includes a silane coupling agent and / or a titanate coupling agent.

[0040] It should be noted that the present invention does not impose any special restrictions on the specific selection of silane coupling agents and titanate coupling agents, and commonly used silane coupling agents and titanate coupling agents in the art are applicable.

[0041] Preferably, the compounded polyurethane further includes a crosslinking agent A.

[0042] Based on 100 parts by weight of the polyurethane raw rubber, the crosslinking agent A is 0.5-4 parts by weight, for example, it can be 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.3 parts, 2.5 parts, 2.7 parts, 3 parts, 3.3 parts, 3.6 parts, 3.8 parts, or 4 parts, etc.

[0043] Preferably, the crosslinking agent includes a primary vulcanizing agent A and an optional co-vulcanizing agent A.

[0044] Preferably, the main vulcanizing agent A includes a peroxide vulcanizing agent.

[0045] Preferably, the peroxide vulcanizing agent includes alkyl peroxides and / or diacyl peroxides.

[0046] Preferably, the alkyl peroxide includes any one or a combination of at least two of di-tert-butyl peroxide, diisocyanate peroxide, 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane or 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

[0047] Preferably, the diacyl peroxide includes benzoyl peroxide and / or tert-butyl perbenzoate.

[0048] Preferably, the co-vulcanizing agent A includes any one or a combination of at least two of sulfur, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), or N,N'-m-phenylene-bismaleimide (HVA-2).

[0049] Preferably, the mass ratio of the main vulcanizing agent A to the auxiliary vulcanizing agent A is 1:(1-2.5), for example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4 or 1:2.5, etc.

[0050] In this invention, there are no special limitations on the preparation method of compounded polyurethane; commonly used preparation methods in the art are applicable. Taking compounded polyurethane containing a crosslinking agent as an example, its preparation method includes, but is not limited to:

[0051] After mixing all components except the crosslinking agent in an internal mixer until homogeneous, the crosslinking agent is added and mixed using a two-roll mill. Once all components are mixed evenly, the compounded polyurethane is obtained.

[0052] Thirdly, the present invention provides a polyurethane compound molded article, wherein the raw materials for preparing the polyurethane molded article include the compounded polyurethane as described in the second aspect and optional crosslinking agent B;

[0053] Based on 100 parts by weight of raw polyurethane in the compounded polyurethane, the crosslinking agent B is 0.5-4 parts by weight, for example, 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.3 parts, 2.5 parts, 2.7 parts, 3 parts, 3.3 parts, 3.6 parts, 3.8 parts, or 4 parts, etc.

[0054] It should be noted that the crosslinking agent in the polyurethane molded body can be provided by the compounded polyurethane itself (i.e., the compounded polyurethane contains a crosslinking agent), or it can be added separately when preparing the polyurethane molded body.

[0055] As a preferred embodiment of the present invention, the crosslinking agent B includes a primary vulcanizing agent B and a co-vulcanizing agent B.

[0056] Preferably, the main vulcanizing agent B includes a peroxide vulcanizing agent.

[0057] Preferably, the peroxide vulcanizing agent includes alkyl peroxides and / or diacyl peroxides.

[0058] Preferably, the alkyl peroxide includes any one or a combination of at least two of di-tert-butyl peroxide, diisocyanate peroxide, 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane or 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

[0059] Preferably, the diacyl peroxide includes benzoyl peroxide and / or tert-butyl perbenzoate.

[0060] Preferably, the co-vulcanizing agent B includes any one or a combination of at least two of sulfur, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), or N,N'-m-phenylene-bismaleimide (HVA-2).

[0061] Preferably, the mass ratio of the main vulcanizing agent B to the auxiliary vulcanizing agent B is 1:(1-2.5), for example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4 or 1:2.5, etc.

[0062] As a preferred embodiment of the present invention, the polyurethane compound further includes additives.

[0063] Preferably, based on 100 parts by weight of raw polyurethane in the compounded polyurethane, the amount of additives is 0.5-8 parts by weight, for example, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, or 8 parts, etc.

[0064] Preferably, the additives include any one or a combination of at least two of the following: anti-yellowing agents, anti-hydrolysis agents, antioxidants, and lubricants.

[0065] Preferably, the anti-yellowing agent includes any one or a combination of at least two of the following: anti-yellowing agent NH-130, anti-yellowing agent NH-150, anti-yellowing agent SAS, or anti-yellowing agent UHS.

[0066] The antioxidants include any one or a combination of at least two of antioxidants 1010, 1135, 1076, or 1222.

[0067] The anti-hydrolysis agents include anti-hydrolysis agent 1010 and / or anti-hydrolysis agent Stabaxol-1.

[0068] The lubricant includes any one or a combination of at least two of stearic acid, stearate, oleamide, paraffin, or polytetrafluoroethylene.

[0069] As a preferred embodiment of the present invention, the Shore A hardness of the polyurethane compound is 60-75 (e.g., it can be 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 or 75, etc.), and the right-angle tear strength is ≥75kN / m (e.g., it can be 75kN / m, 78kN / m, 80kN / m, 81kN / m, 84kN / m, 86kN / m, 88kN / m, 91kN / m, 94kN / m, 95kN / m, 97kN / m, 98kN / m, 100kN / m, 101kN / m, 102kN / m or 105kN / m, etc.).

[0070] Fourthly, the present invention provides a method for preparing a polyurethane compound as described in the third aspect, the method comprising the following steps:

[0071] The polyurethane compound is crosslinked to obtain the polyurethane compound molded body.

[0072] Preferably, the crosslinking temperature is 145-185℃ (e.g., 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, or 185℃, etc.), and the crosslinking time is measured by a vulcanizing apparatus at the corresponding temperature. 90 time.

[0073] In this invention, the crosslinking methods include, but are not limited to, pressure heat vulcanization or medium heat vulcanization.

[0074] It should be noted that in this invention, the additives can be mixed in the compounded polyurethane, and then mixed with the crosslinking agent to prepare the polyurethane compounded molded body through crosslinking. Alternatively, the compounded polyurethane, additives and crosslinking agent can be mixed and the polyurethane compounded molded body can be prepared through crosslinking.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] This invention designs the raw materials for preparing polyurethane raw rubber, and obtains high-performance polyurethane raw rubber by using polyester polyols without side chains and aliphatic symmetrical polyisocyanates. In addition, it prepares a compounded polyurethane that, while ensuring transparency and resistance to yellowing (A method ≥ 4 grade, B method ≥ 4 grade), has a tear strength ≥ 75 kN / m at a hardness of 65-70A. Detailed Implementation

[0077] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0078] The sources of some components in the examples and comparative examples are shown in Table 1 below:

[0079] Table 1

[0080]

[0081] The number-average molecular weight of the above polyols varies depending on the production batch. The average molecular weight of the polyols in the embodiments of this invention is used for calculation.

[0082] The calculation methods for the isocyanate index (R value) and Mooney viscosity ML (1+4, 100°C) of the polyurethane raw rubber provided in the comparative examples below are as follows:

[0083] Isocyanate index (R value): It is obtained by calculating the ratio of the molar amount of NCO groups in the polyisocyanate to the molar amount of NCO-reactive groups in the polyester polyol and chain extender.

[0084] Mooney viscosity ML (1+4, 100℃): Tested using the MN-2000 high-speed rail equipment according to GB 1232 standard, where M represents Mooney, L represents the use of a large rotor, 1 represents a preheating time of 1 min, 4 represents a rotation time of 4 min, and 100℃ represents a test temperature of 100℃.

[0085] Example 1

[0086] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0087] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1 and hexamethylene diisocyanate were mixed, and the R value was controlled at 0.985. 200 ppm of bismuth neodecanoate catalyst was added. After reacting at 85°C for 10 minutes, the mixture was poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0088] The Mooney viscosity (ML, 1+4, 100℃) of the polyurethane raw rubber was tested to be 82.

[0089] Example 2

[0090] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0091] 100 parts by weight of butylene adipate, ethylene glycol, polyol 2 and hexamethylene diisocyanate were mixed, and the R value was controlled at 0.982. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0092] The Mooney viscosity (ML1+4, 100℃) of the raw polyurethane rubber was tested to be 75.

[0093] Example 3

[0094] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0095] 100 parts by weight of polycaprolactone polyol 1 and dicyclohexyl diisocyanate were mixed, and the R value was controlled at 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0096] The Mooney viscosity (ML, 1+4, 100℃) of the polyurethane raw rubber was tested to be 81.

[0097] Example 4

[0098] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0099] 100 parts by weight of polycaprolactone polyol 2 and 1 part by weight of 1,6-hexanediol were mixed, and 9.33 parts by weight of dicyclohexylmethane diisocyanate were added to adjust its R value to 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0100] The Mooney viscosity (ML, 1+4, 100℃) of the raw polyurethane was tested to be 79.

[0101] Example 5

[0102] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0103] 100 parts by weight of butylene adipate glycol ethylene glycol polyol 1 and 1 part by weight of 1,4-butanediol were mixed, and 10.12 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0104] The Mooney viscosity (ML1+4, 100℃) of the polyurethane raw rubber was tested to be 83.

[0105] Example 6

[0106] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0107] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and 3.5 parts by weight of 1,4-butanediol were mixed, and 14.65 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.980. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0108] The Mooney viscosity (ML, 1+4, 100℃) of the raw polyurethane was tested to be 76.

[0109] Example 7

[0110] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0111] 100 parts by weight of butylene adipate glycol ethylene glycol polyol 1 and 1 part by weight of 1,4-butanediol were mixed, and 10.04 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.977. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0112] The Mooney viscosity (ML1+4, 100℃) of the polyurethane raw rubber was tested to be 65.

[0113] Example 8

[0114] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0115] 100 parts by weight of butylene adipate glycol ethylene glycol polyol 1 and 1 part by weight of 1,4-butanediol were mixed, and 10.07 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.980. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0116] The Mooney viscosity (ML, 1+4, 100℃) of the raw polyurethane was tested to be 73.

[0117] Example 9

[0118] This embodiment provides a polyurethane raw rubber and its preparation method. The preparation method of the polyurethane raw rubber is as follows:

[0119] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and 1 part by weight of 1,4-butanediol were mixed, and 10.18 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.990. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0120] The Mooney viscosity (ML, 1+4, 100℃) of the raw polyurethane was tested to be 89.

[0121] Comparative Example 1

[0122] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0123] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and 1 part by weight of 1,2-propanediol were mixed, and 10.46 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0124] The Mooney viscosity (ML1+4, 100℃) of the polyurethane raw rubber was tested to be 83.

[0125] Comparative Example 2

[0126] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0127] 100 parts by weight of polytetramethylene ether polyol and hexamethylene diisocyanate were mixed, and the R value was controlled at 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0128] The Mooney viscosity (ML1+4, 100℃) of the raw polyurethane was tested to be 78.

[0129] Comparative Example 3

[0130] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0131] 100 parts by weight of a polyester polyol containing side chains and hexamethylene diisocyanate were mixed, with the R value controlled at 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the raw polyurethane.

[0132] The Mooney viscosity (ML, 1+4, 100℃) of the polyurethane raw rubber was tested to be 81.

[0133] Comparative Example 4

[0134] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0135] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and 5 parts by weight of 1,4-butanediol were mixed, and 17.49 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0136] The Mooney viscosity (ML, 1+4, 100℃) of the polyurethane raw rubber was tested to be 81.

[0137] Comparative Example 5

[0138] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0139] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and 1 part by weight of 1,4-butanediol were mixed, and 10.01 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 0.974. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0140] The Mooney viscosity (ML1+4, 100℃) of the raw polyurethane rubber was tested to be 55.

[0141] Comparative Example 6

[0142] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0143] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1 and 1 part by weight of 1,4-butanediol were mixed, and 10.48 parts by weight of hexamethylene diisocyanate were added to adjust its R value to 1.02. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the polyurethane raw rubber.

[0144] The Mooney viscosity (ML1+4, 100℃) of the raw polyurethane rubber was tested to be 95.

[0145] Comparative Example 7

[0146] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0147] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1, and isophorone diisocyanate (IPDI) were mixed, with an R value of 0.985. 200 ppm of bismuth neodecanoate catalyst was added, and the mixture was reacted at 85°C for 10 minutes. The mixture was then poured into a tray and baked at 120°C for 20 hours to obtain the raw polyurethane rubber.

[0148] The Mooney viscosity (ML, 1+4, 100℃) of the polyurethane raw rubber was tested to be 81.

[0149] Comparative Example 8

[0150] This comparative example provides a polyurethane raw material and its preparation method. The preparation method of the polyurethane raw material is as follows:

[0151] 100 parts by weight of butylene adipate, ethylene glycol, polyol 1 and 4,4'-diphenylmethane diisocyanate were mixed, with an R value of 0.985. 200 ppm of bismuth neodecanoate catalyst was added. The mixture was reacted at 85°C for 10 minutes and then poured into a tray. The mixture was baked at 120°C for 20 hours to obtain the raw polyurethane rubber.

[0152] The Mooney viscosity (ML1+4, 100℃) of the polyurethane raw rubber was tested to be 83.

[0153] Application Examples 1-9, Comparative Application Examples 1-8

[0154] Application Examples 1-9 and Comparative Application Examples 1-8 respectively provide a compounded polyurethane and a polyurethane compounded molded body. The compounded polyurethane includes polyurethane raw rubber, reinforcing agent, coupling agent and additives. The specific selection and dosage of polyurethane raw rubber, reinforcing agent, coupling agent and additives are detailed in Table 2 below (the dosage of the above components in Table 2 are all parts by weight).

[0155] The preparation method of the above-mentioned compounded polyurethane is as follows:

[0156] The polyurethane raw rubber, reinforcing agent, coupling agent and additives are mixed evenly to obtain the compounded polyurethane.

[0157] The polyurethane compound is prepared by compounded polyurethane and crosslinking agent. The specific selection and dosage of crosslinking agent are detailed in Table 2 below (the dosage of the above components in Table 2 are all parts by weight).

[0158] The preparation method of the above-mentioned polyurethane compound is as follows:

[0159] The components of the polyurethane compound are mixed and crosslinked at 155°C for 5 minutes using an internal mixer. After uniform mixing, the mixture is sheeted out to obtain the polyurethane compound.

[0160] The sources of some of the components used in Tables 2 and 3 are as follows:

[0161] Silica: Grade JS-185;

[0162] Silane coupling agent A-172: Vinyltris(β-methoxyethoxy)silane;

[0163] Silane coupling agent KH570: γ-methacryloyloxypropyltrimethoxysilane;

[0164] Anti-yellowing agent NH130: brand name NH130;

[0165] Antioxidant 1010 and anti-hydrolysis agent Stabaxol-1: Commercially available products.

[0166] The properties of the polyurethane compound molded articles provided in the above application examples and comparative application examples were tested. The test standards and test results are shown in Tables 2-3 below:

[0167] Table 2

[0168]

[0169]

[0170] Table 3

[0171]

[0172] In Comparative Examples 4 and 6, the Mooney viscosity of the polyurethane raw rubber used was too high, making it impossible to mix and thus impossible to perform data characterization.

[0173] As described above, this invention designs the raw materials for preparing polyurethane raw rubber, and obtains high-performance polyurethane raw rubber through the preparation of polyester polyols without side chains and aliphatic symmetrical polyisocyanates. Furthermore, it prepares a compounded polyurethane that, while maintaining transparency and resistance to yellowing (A method ≥ grade 4, B method ≥ grade 4), has a right-angle tear strength ≥ 75 kN / m at a hardness of 65–70 A, specifically 75–101 kN / m. The prepared compounded polyurethane also possesses excellent other mechanical properties, with a tensile strength of 24–28 MPa, an elongation of 527–612%, and an abrasion resistance of 39–47 mm. 3 .

[0174] As can be seen from Application Examples 1-9 and Comparative Application Examples 1-2, Comparative Application Example 3, and corresponding Case Examples 7-8, the present invention, through the use of side-chain-free polyester polyol, aliphatic symmetrical polyisocyanate, and side-chain-free chain extender, prepares a compounded polyurethane that, while ensuring transparency and resistance to yellowing, also possesses high hardness and high tear strength.

[0175] As can be seen from Application Example 1, Application Examples 5-6, and Comparative Application Example 4, this invention obtains high-performance polyurethane raw rubber by controlling the amount of chain extender in the preparation of polyurethane raw rubber within a specific range, and then obtains compounded polyurethane with excellent comprehensive performance.

[0176] As can be seen from Application Examples 1, 7-9, and Comparative Application Examples 5-6, this invention, by designing the raw materials for preparing polyurethane raw rubber, prepared polyurethane raw rubber with suitable Mooney viscosity, thus obtaining polyurethane raw rubber with excellent performance, and further obtaining compounded polyurethane with excellent comprehensive performance.

[0177] In summary, this invention designs the raw materials for preparing polyurethane raw rubber and obtains high-performance polyurethane raw rubber by using non-side-chain polyester polyol and aliphatic symmetrical polyisocyanate. Furthermore, it prepares a compounded polyurethane that, while ensuring transparency and resistance to yellowing (A method ≥ grade 4, B method ≥ grade 4), has a tear strength ≥ 75 kN / m at a hardness of 65-70 A.

[0178] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A type of polyurethane raw rubber, characterized in that, The raw materials for preparing the polyurethane raw rubber include polyester polyol and polyisocyanate; The polyester polyol is selected from polyester polyols without side chains; The polyisocyanate is selected from aliphatic symmetrical polyisocyanates.

2. The polyurethane raw rubber according to claim 1, characterized in that, The number-average molecular weight of the polyester polyol is 1000-4000 g / mol; Preferably, the polyester polyol is selected from polyadipate-based polyols and / or polycaprolactone-based polyols; Preferably, the aliphatic symmetrical polyisocyanate includes hexamethylene diisocyanate and / or dicyclohexylmethane diisocyanate.

3. The polyurethane raw rubber according to claim 1 or 2, characterized in that, The raw materials for preparing the polyurethane raw rubber also include chain extenders; Preferably, based on the mass percentage of the raw materials for preparing the polyurethane raw rubber being 100%, the mass percentage of the chain extender is ≤3%. Preferably, the chain extender is selected from small molecule diols that do not have side chains; Preferably, the small molecule diol without side chains is selected from any one or a combination of at least two of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol or 1,6-hexanediol. Preferably, the raw materials for preparing the polyurethane raw rubber do not contain chain extenders.

4. The polyurethane raw rubber according to any one of claims 1-3, characterized in that, The isocyanate index of the raw polyurethane rubber is 0.91 to 1, preferably 0.98 to 0.99; Preferably, the Mooney viscosity ML (1+4, 100°C) of the polyurethane raw rubber is 65-90, and more preferably 70-90.

5. A compounded polyurethane, characterized in that, The compounded polyurethane comprises the following components in parts by weight: 100 parts of the polyurethane raw rubber as described in any one of claims 1-4; 15-40 parts of reinforcing agent; 0.5-2 parts of coupling agent.

6. The compounded polyurethane according to claim 5, characterized in that, The reinforcing agent includes silica and / or calcium carbonate; Preferably, the reinforcing agent in the compounded polyurethane is 20-30 parts by weight; Preferably, the coupling agent comprises a silane coupling agent and / or a titanate coupling agent; Preferably, the compounded polyurethane further includes a crosslinking agent A; Based on 100 parts by weight of the polyurethane raw rubber, the crosslinking agent A is 0.5-4 parts by weight; Preferably, the crosslinking agent includes a primary vulcanizing agent A and an optional co-vulcanizing agent A; Preferably, the mass ratio of the main vulcanizing agent A to the auxiliary vulcanizing agent A is 1:(1-2.5).

7. A polyurethane compound molded article, characterized in that, The raw materials for preparing the polyurethane molded article include the compounded polyurethane as described in claim 5 or 6 and optional crosslinking agent B; With the weight of the raw polyurethane in the compounded polyurethane being 100 parts, the weight of the crosslinking agent B is 0.5-4 parts.

8. The polyurethane compound molded article according to claim 7, characterized in that, The crosslinking agent B includes a primary vulcanizing agent B and an optional co-vulcanizing agent B; Preferably, the main vulcanizing agent B includes a peroxide vulcanizing agent; Preferably, the peroxide vulcanizing agent comprises alkyl peroxides and / or diacyl peroxides; Preferably, the alkyl peroxide includes any one or a combination of at least two of di-tert-butyl peroxide, diisocyanate peroxide, 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane or 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane. Preferably, the diacyl peroxide comprises benzoyl peroxide and / or tert-butyl perbenzoate; Preferably, the co-vulcanizing agent B includes any one or a combination of at least two of sulfur, triallyl isocyanurate, triallyl cyanurate, or N,N'-m-phenylene-bismaleimide. Preferably, the mass ratio of the main vulcanizing agent B to the auxiliary vulcanizing agent B is 1:(1-2.5).

9. The polyurethane compound molded article according to claim 7 or 8, characterized in that, The polyurethane compound also includes additives; Preferably, based on 100 parts by weight of raw polyurethane in the compounded polyurethane, the amount of additives is 0.5-8 parts by weight. The additives include any one or a combination of at least two of the following: anti-yellowing agents, anti-hydrolysis agents, antioxidants, and lubricants.

10. A method for preparing a polyurethane compound molded article as described in any one of claims 7-9, characterized in that, The preparation method includes the following steps: The polyurethane compound is crosslinked to obtain the polyurethane compound molded body.

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