A scratch-resistant polyurethane engineering plastic
By using the polymerization reaction of high-rigidity diisocyanate and small molecule diol, scratch-resistant polyurethane engineering plastics were prepared, solving the problem of wear and scratches on polymer materials during use, and achieving a combination of high transparency, high toughness and high surface hardness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MIRACLL CHEM
- Filing Date
- 2025-01-23
- Publication Date
- 2026-05-26
Smart Images
Figure BDA0005256610940000071
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thermoplastic polyurethane resins, specifically relating to a polyurethane engineering plastic with inherent scratch resistance and its preparation method. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] Commonly used polymer materials for making rigid outer shells, such as ABS, polycarbonate, copolyester, and nylon, will all have marks left on their surfaces due to friction and scratches during daily use. These marks cannot be removed and significantly affect the appearance of the product. Although polymethyl methacrylate has a high surface hardness, it has extremely poor toughness, is notch sensitive, and is prone to stress cracking, making it unsuitable for applications requiring impact and drop resistance.
[0004] To address the issue of scratches and abrasions easily forming on the surface of polymer materials during use, two main approaches are employed. One is surface treatment to increase the surface hardness of the outer shell; the other is bulk modification to directly improve the surface hardness of the material itself. Surface treatment increases processing complexity and production costs, and the surface treatment agent gradually detaches during use, causing the surface hardness to decrease again. Directly improving the surface hardness of the material itself is currently generally achieved through blending modification. While the addition of modifiers such as polymethyl methacrylate improves surface hardness, it also significantly reduces the material's toughness. In summary, existing methods struggle to simultaneously meet the performance requirements of permanent transparency, high toughness, and high surface hardness. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides a polyurethane engineering plastic with a scratch-resistant body and a method for preparing the same.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] In a first aspect, the present invention provides a polyurethane engineering plastic with a scratch-resistant body, which is polymerized from the following raw materials in weight percentages: 45wt% to 68wt% rigid diisocyanate, 32wt% to 55wt% small molecule diol, and 10 to 2000ppm catalyst, wherein the sum of the percentages of the raw materials is 100%.
[0008] The rigid diisocyanate described herein has two characteristics:
[0009] (1) Both isocyanate groups are directly attached to the alicyclic or aromatic ring;
[0010] (2) There are no flexible groups connecting the alicyclic and aromatic rings within the molecule, and the flexible groups include: methylene and ether bonds;
[0011] The small molecule diol contains an ester ring.
[0012] In some embodiments, the rigid diisocyanate is selected from at least one of terephthalic diisocyanate, 1,5-naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, and 3,3'-dimethyl-4,4'-biphenyl diisocyanate.
[0013] Small molecule diols all contain rigid alicyclic rings, which, combined with highly rigid diisocyanates, enhance the rigidity of the main chain, giving the polymer high modulus and high surface hardness. Simultaneously, the alicyclic structure of the selected small molecule diols reduces the regularity of the main chain, effectively inhibiting polyurethane segment crystallization and resulting in high transparency in the product. Therefore, in some embodiments, the small molecule diol is selected from at least one of isosorbide, tricyclo[5.2.1,2,6]decanediethanol, 1,4-cyclohexanediethanol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.
[0014] Although isocyanates generally exhibit high reactivity with hydroxyl groups and can react spontaneously, actual experiments have shown that the steric hindrance effect of alicyclic diols significantly reduces the reactivity of the hydroxyl group. Without a catalyst, the degree of polymerization will be severely affected, further impacting product performance. Adding a catalyst can effectively shorten the viscosity increase rate and increase the molecular weight of the product. Therefore, in some embodiments, the catalyst is an organotin or organobismuth esterification catalyst.
[0015] In some embodiments, the catalyst is stannous octoate or bismuth neodecanoate.
[0016] Increased main-chain rigidity raises the glass transition temperature (Tg) of the material, thereby improving its processability. Excessively high processing temperatures accelerate the degradation of polyurethane during processing, affecting the product's appearance and performance. Considering this, the present invention does not use a fully aromatic main chain (i.e., polymerization of aromatic diisocyanates and aromatic small-molecule diols) as an option. Meanwhile, in some embodiments, linear small-molecule diols are used to partially replace small-molecule diols containing ester rings, sacrificing a slight increase in surface hardness to achieve lower processing temperatures.
[0017] A second aspect of the present invention provides a method for preparing a polyurethane engineering plastic with a scratch-resistant bulk, comprising:
[0018] The small molecule diol is heated to 80–150°C, and a rigid diisocyanate and catalyst are added. The mixture is stirred until viscous, then stirring is stopped, and the mixture is aged at 90–120°C to obtain the final product.
[0019] In some embodiments, the stirring speed is 500 to 1500 r / min.
[0020] In some embodiments, the curing time is 12h to 24h.
[0021] A third aspect of the present invention provides the application of the above-described scratch-resistant polyurethane engineering plastic in the fields of construction, automotive, aerospace, thermal insulation, and mechanical parts.
[0022] Beneficial effects of the present invention
[0023] (1) The scratch resistance of a material is related to its surface resistance to deformation or damage. Generally speaking, the stronger the main chain of a material, the higher its strength and the harder its surface. However, high main chain rigidity generally means poor material toughness and high processing difficulty. Traditional materials cannot simultaneously meet the requirements of transparency, high toughness, and high surface hardness. The polyurethane engineering plastic with a scratch-resistant body provided by this invention introduces a large number of high-rigidity groups into the main chain through polymer structure design, fundamentally solving the problem of low surface hardness of the material while retaining the structural characteristics of polyurethane. The product obtained by this invention has high transparency, high strength, and high toughness of polyurethane engineering plastic, as well as high surface hardness, which can meet the needs of various easily worn and scratched appearance parts.
[0024] (2) The preparation method of the present invention is simple, practical and easy to promote. Detailed Implementation
[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0026] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.
[0027] Example 1
[0028] 146.14 g of isosorbide was heated to 80 °C and poured into a reaction vessel. While stirring at 1500 rpm, 169.50 g of 1,4-cyclohexane diisocyanate was rapidly added to the reaction vessel, along with 0.63 g of bismuth neodecanoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 90 °C oven for 24 h to mature, yielding a high-hardness polyurethane engineering plastic.
[0029] Example 2
[0030] 196.28 g of tricyclo[5.2.1,2,6]decanediethanol was heated to 150 °C and poured into a reaction vessel. 214.39 g of terephthalic diisocyanate and 0.36 g of stannous octoate catalyst were rapidly added to the reaction vessel while stirring at 500 rpm. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 120 °C oven for 12 h to mature, yielding a high-hardness polyurethane engineering plastic.
[0031] Example 3
[0032] 144.21 g of 1,4-cyclohexanediethanol was heated to 100 °C and poured into a reaction vessel. While stirring at 1000 rpm, 169.50 g of 1,5-naphthalene diisocyanate and 0.0035 g of stannous octoate catalyst were rapidly added to the reaction vessel. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0033] Example 4
[0034] 144.21 g of 2,2,4,4-tetramethyl-1,3-cyclobutanediol was heated to 100 °C and poured into a reaction vessel. 272.21 g of 3,3'-dimethyl-4,4'-biphenyl diisocyanate was rapidly added to the reaction vessel while stirring at 1000 rpm, along with 0.008 g of stannous octoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0035] Example 5
[0036] 146.14 g of isosorbide was heated to 100 °C and poured into a reaction vessel. While stirring at 1000 rpm, 161.73 g of terephthalic diisocyanate was rapidly added to the reaction vessel, along with 0.03 g of stannous octoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 hours to mature, yielding a high-hardness polyurethane engineering plastic.
[0037] Example 6
[0038] 86.53 g of 1,4-cyclohexanediethanol and 57.68 g of 2,2,4,4-tetramethyl-1,3-cyclobutanediol were heated to 100 °C and poured into a reaction vessel. Under stirring at 1000 rpm, 214.39 g of 1,5-naphthalene diisocyanate and 0.06 g of bismuth neodecanoate catalyst were rapidly added to the reaction vessel. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0039] Example 7
[0040] 144.21 g of 1,4-cyclohexanediethanol was heated to 100 °C and poured into a reaction vessel. While stirring at 1000 rpm, 84.75 g of 1,4-cyclohexanediisocyanate and 81.66 g of terephthalic diisocyanate were rapidly added to the reaction vessel, along with 0.2 g of bismuth neodecanoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0041] Example 8
[0042] 100.95 g of 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 27.04 g of 1,4-butanediol were heated to 100 °C and poured into a reaction vessel. 272.21 g of 3,3'-dimethyl-4,4'-biphenyl diisocyanate was rapidly added to the reaction vessel while stirring at 1000 rpm, along with 0.008 g of stannous octoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0043] Comparative Example 1
[0044] 144.21 g of 1,4-cyclohexanediethanol was heated to 100 °C and poured into a reaction vessel. 255.24 g of 4,4-diphenylmethane diisocyanate was rapidly added to the reaction vessel while stirring at 1000 rpm, along with 0.2 g of stannous octoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 h to obtain a high-hardness polyurethane engineering plastic.
[0045] Comparative Example 2
[0046] 90.12 g of 1,4-butanediol was heated to 100 °C and poured into a reaction vessel. While stirring at 1000 rpm, 255.24 g of 4,4-diphenylmethane diisocyanate was rapidly added to the reaction vessel, along with 0.2 g of stannous octoate catalyst. The mixture was stirred until viscous, then stirring was stopped. The polymer, along with the reaction vessel, was placed in a 100 °C oven for 16 hours to cure, yielding a high-hardness polyurethane engineering plastic.
[0047] The pencil hardness test method is as follows: the obtained thermoplastic polyurethane resin product is crushed, injection molded, and then tested according to standard GB / T 6739-2006.
[0048] The tensile strength assessment method is as follows: the obtained thermoplastic polyurethane resin product is crushed, injection molded, and then tested according to standard ISO 527.
[0049] The impact strength assessment method is as follows: The obtained thermoplastic polyurethane resin product is crushed, injection molded, and then tested according to the standard ASTM D256. The specimen thickness is 3.2 mm, and a notch is milled using a cutter with an angle radius of 0.25 mm. The test temperature is 25°C.
[0050] Table 1. Performance test results of thermoplastic polyurethane resin
[0051]
[0052] A comparison of Example 3 and Comparative Example 1 shows that, compared with MDI, the use of high-rigidity diisocyanate (NDI) can significantly improve pencil hardness. A comparison of Comparative Example 1 and Comparative Example 2 shows that, compared with BDO, the use of alicyclic diol (CHDM) can improve pencil hardness.
[0053] A comparison of Examples 4 and 8 shows that after partially replacing alicyclic diols with butanediol, the pencil hardness of the product decreases slightly, but due to the reduction in the rigid structure of the main chain, a lower processing temperature can be obtained.
[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A polyurethane engineering plastic with inherent scratch resistance, characterized in that, It is polymerized from the following raw materials in weight percentages: 45wt%~68wt% rigid diisocyanate, 32wt%~55wt% small molecule diol, and 10~2000ppm catalyst, with the sum of the percentages of each raw material being 100%. The rigid diisocyanate described herein has two characteristics: (1) Both isocyanate groups are directly attached to the alicyclic or aromatic ring; (2) There are no flexible groups connecting the alicyclic and aromatic rings within the molecule, and the flexible groups include: methylene and ether bonds; The small molecule diol is selected from at least one of tricyclo[5.2.1,2,6]decanediethanol, 1,4-cyclohexanediethanol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol; The catalyst is bismuth neodecanoate; The rigid diisocyanate is selected from at least one of terephthalic diisocyanate, 1,5-naphthalene diisocyanate, and 1,4-cyclohexane diisocyanate.
2. The method for preparing the scratch-resistant polyurethane engineering plastic of claim 1, characterized in that, include: The small molecule diol is heated to 80~150℃, a rigid diisocyanate and a catalyst are added, and the mixture is stirred until viscous. Then the stirring is stopped and the mixture is aged at 90~120℃ to obtain the final product.
3. The method for preparing the scratch-resistant polyurethane engineering plastic as described in claim 2, characterized in that, The stirring speed is 500~1500 r / min.
4. The method for preparing the scratch-resistant polyurethane engineering plastic as described in claim 2, characterized in that, The ripening time is 12h to 24h.
5. The application of the scratch-resistant polyurethane engineering plastic of claim 1 in the fields of construction, automobiles, aerospace industry, thermal insulation, and mechanical parts.