Polyurethane anti-stone impact coatings, polyurethane anti-stone impact films, their preparation methods and applications

Abstract

This invention discloses a polyurethane anti-stone impact coating, a polyurethane anti-stone impact film, and their preparation methods and applications. The polyurethane anti-stone impact coating comprises a first component and a second component; wherein the first component includes the following components: black pigment, catalyst, antioxidant, flame retardant, aromatic glycol chain extender, high-resilience polyether polyol, and high-functionality polyether polyol; the second component includes polytetrahydrofuran-modified toluene diisocyanate prepolymer and crude MDI. The prefabricated polyurethane anti-stone impact film of this invention is prefabricated according to the shape of the workpiece to be coated. During assembly, adhesive is applied to the back of the polyurethane anti-stone impact film, and it is then adhered to the workpiece and pressed firmly.

Description

Technical Field

[0001] This invention belongs to the field of anti-stone impact coating and assembly technology, specifically relating to a polyurethane anti-stone impact coating, a polyurethane anti-stone impact film, and their preparation methods and applications. Background Technology

[0002] The power batteries used in new energy vehicles are very large, typically weighing over 100 kilograms. Due to safety and vehicle weight considerations, they are usually placed under the vehicle. During operation, the undercarriage and wheel wells are frequently subjected to impacts and erosion from mud, gravel, and sewage. Ordinary paints are easily damaged, losing their protective ability and causing these areas to corrode quickly. Therefore, anti-stone-impact coatings must be used on these areas.

[0003] Currently, the main products used in this field are PVC anti-stone impact coatings. For example, patent ZL201910023650.0 discloses an automotive PVC anti-stone impact coating, its preparation method, and its application. This automotive PVC anti-stone impact coating contains 10-20% polyvinyl chloride paste resin and 0.1-5% thermally expanded microspheres by weight. It can reduce the weight of the anti-stone impact coating by 50%, reaching approximately 5 kg, thus achieving automotive lightweighting. The bubbles formed by the expanded microspheres have a closed-cell structure, preventing cross-contamination. Furthermore, the bubbles are uniform in size and regularly distributed, thus not affecting the mechanical properties of the paint film, such as poor abrasion resistance, reduced corrosion resistance, or easy penetration and retention of moisture. The dense structure of the expanded microspheres allows it to integrate with a highly resistant matrix, resulting in excellent protection and improving other properties of the paint film. However, coatings of this type have the following problems: 1. The pressure plate spraying machine is noisy and the site is noisy; 2. Defects such as pits are easily formed on the material surface; 3. The material is baked at 140℃ for 30 minutes, which consumes a lot of energy; 4. There is waste in spraying and the recycling of secondary materials is troublesome; 5. Unpainted areas need to be masked, which limits the efficiency of operation; 6. The adhesion to bare aluminum is generally not good. Summary of the Invention

[0004] The main objective of this invention is to provide a polyurethane anti-stone impact coating, a polyurethane anti-stone impact film, and their preparation methods and applications, so as to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] This invention provides a polyurethane anti-stone chip coating, which includes a first component and a second component;

[0007] The first component includes the following components: black colorant, catalyst, antioxidant, flame retardant, aromatic diol chain extender, high-resilience polyether polyol and high-functionality polyether polyol; the second component includes polytetrahydrofuran modified toluene diisocyanate prepolymer and crude MDI.

[0008] This invention also provides a method for preparing the aforementioned polyurethane anti-stone chip coating, comprising:

[0009] The flame retardant, high resilience polyether polyol, high functionality polyether polyol, and aromatic diol chain extender are mixed and stirred evenly. Then, black colorant, catalyst, and antioxidant are added in sequence, and the mixture is stirred at a speed of 1000-1500 r / min for 10-15 min to obtain the first component.

[0010] Furthermore, the polytetrahydrofuran-modified toluene diisocyanate prepolymer was stirred and mixed evenly with crude MDI to obtain the second component.

[0011] This invention also provides a method for preparing an assembled polyurethane anti-stone impact membrane, comprising:

[0012] Provide the aforementioned polyurethane anti-stone chip coating;

[0013] The first and second components of the polyurethane anti-stone impact coating are heated to 55-65°C, and then poured and demolded to obtain an assembled polyurethane anti-stone impact film.

[0014] The present invention also provides an assembled polyurethane anti-stone impact membrane prepared by the aforementioned preparation method.

[0015] The present invention also provides the use of the aforementioned polyurethane anti-stone chip coating or assembled polyurethane anti-stone chip film in automobile chassis or wheel mudguards.

[0016] This invention also provides a method for using a prefabricated polyurethane anti-stone impact membrane, comprising:

[0017] Provide the aforementioned prefabricated polyurethane anti-stone impact membrane;

[0018] Adhesive is applied to the surface of the assembled polyurethane anti-stone impact film, and then one side of the assembled polyurethane anti-stone impact film with adhesive is bonded to the workpiece, thereby realizing the assembly of the assembled polyurethane anti-stone impact film and the workpiece.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) The polyurethane anti-stone impact coating prepared by the present invention is provided by high-resilience polyether polyol with a functionality of 2-4, aromatic diol chain extender, and polytetrahydrofuran modified toluene diisocyanate prepolymer to provide soft segments, which are used to improve the flexibility and impact resistance at low temperature; and by high-functionality polyether polyol with a functionality of 4-6 and part of crude MD self-polymer to provide hard segments, which are used to improve the strength of the coating film, increase the tensile strength and hardness, and adjust the ratio of soft segments and hard segments to meet the technical requirements of anti-stone impact.

[0021] (2) The assembled polyurethane anti-stone impact film prepared by the present invention is a pre-made polyurethane anti-stone impact film. It can be brushed with adhesive and attached to the workpiece without masking. It is simple, quick and efficient.

[0022] (3) The assembled polyurethane anti-stone impact membrane product prepared by the present invention can be stacked and dried, and occupies a small area.

[0023] (4) The prefabricated polyurethane anti-stone impact membrane prepared by the present invention does not require painting or high-temperature baking during assembly and use, which is a brand-new green construction process.

[0024] (5) The assembled polyurethane anti-stone impact film prepared by the invention has better adhesion to bare aluminum and other substrates through the selection of backing adhesive.

[0025] (6) The assembled polyurethane anti-stone impact membrane prepared by the present invention can be a DIY product, and secondary maintenance is easier. Detailed Implementation

[0026] In view of the deficiencies of the prior art, the inventors of this case, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] Specifically, as one aspect of the technical solution of the present invention, a polyurethane anti-stone chip coating includes a first component and a second component.

[0028] The first component includes the following components: black colorant, catalyst, antioxidant, flame retardant, aromatic diol chain extender, high resilience polyether polyol and high functionality polyether polyol; the second component includes polytetrahydrofuran modified toluene diisocyanate prepolymer (denoted as: PTMEG modified TDI prepolymer) and crude MDI.

[0029] In some preferred embodiments, the first component comprises the following components by weight: 0.1 to 0.2 parts of black colorant, 1.0 to 2.0 parts of catalyst, 0.5 to 1.5 parts of antioxidant, 15.0 to 25.0 parts of flame retardant, 15.0 to 25.0 parts of aromatic diol chain extender, 42.0 to 52.0 parts of high-resilience polyether polyol and 8.0 to 12.0 parts of high-functionality polyether polyol.

[0030] In some preferred embodiments, the second component comprises the following components in parts by weight: 20.0 to 30.0 parts of polytetrahydrofuran modified toluene diisocyanate prepolymer and 70.0 to 80.0 parts of crude MDI.

[0031] In some preferred embodiments, the mass ratio of the first component to the second component is 2:1 to 1.1.

[0032] In some preferred embodiments, the black pigment includes a black dye and an organic solvent.

[0033] Furthermore, the solid content in the black pigment is 5-35 wt%.

[0034] Furthermore, the black pigment includes, but is not limited to, Y856 black pigment.

[0035] In some preferred embodiments, the catalyst includes any two or more combinations of catalyst A33, catalyst SMP, catalyst SA-800, catalyst PC-5, catalyst PC-77, and catalyst DMCHA, and is not limited thereto.

[0036] In some preferred embodiments, the antioxidant includes antioxidant 1076 and / or antioxidant 168, but is not limited thereto.

[0037] In some preferred embodiments, the flame retardant includes phosphate ester liquid flame retardants.

[0038] In some preferred embodiments, the flame retardant includes any one or a combination of two or more of TCP flame retardants, TCPP flame retardants, TEP flame retardants, TDCPP flame retardants, and TCEP flame retardants, and is not limited thereto.

[0039] In some preferred embodiments, the hydroxyl value of the aromatic diol chain extender is 400-500 mg KOH / g.

[0040] In some preferred embodiments, the aromatic diol chain extender includes, but is not limited to, the chain extender HER-L.

[0041] In some preferred embodiments, the high-resilience polyether polyol has a hydroxyl value of 25–35 mg KOH / g, a viscosity of 800–1500 MPa·s, and a functionality of 2–4.

[0042] In some preferred embodiments, the high resilience polyether polyol includes any one or a combination of two or more of NJ-360N, CHE-632N, and RT-330, but is not limited thereto.

[0043] In some preferred embodiments, the high-functionality polyether polyol has a hydroxyl value of 380–500 mg KOH / g and a functionality of 4–6.

[0044] In some preferred embodiments, the high-functionality polyether polyol includes, but is not limited to, YHY-4110 and / or INOVOLR8238.

[0045] In some preferred embodiments, the method for preparing the polytetrahydrofuran-modified toluene diisocyanate prepolymer includes: reacting polytetrahydrofuran (PTMEG) and toluene diisocyanate (TDI) at 80-90°C to obtain the polytetrahydrofuran-modified toluene diisocyanate prepolymer.

[0046] Furthermore, the preparation method of the polytetrahydrofuran modified toluene diisocyanate prepolymer includes: adding a metered amount of PTMEG to an open reactor, heating to 80-90°C, adding an appropriate amount of TDI and reacting for 2-3 hours to make the NCO mass fraction between 5-8 wt%, cooling, and obtaining the prepolymer.

[0047] Furthermore, the PTMEG includes any one or a combination of two or more of PTMEG 1000, PTMEG 2000, and PTMEG 3000, and is not limited thereto.

[0048] Furthermore, the TDI is an industrial product, CAS number: 584-84-9.

[0049] Furthermore, the mass fraction of NCO in the PTMEG-modified TDI prepolymer is controlled between 5 and 8 wt%.

[0050] In this invention, the PTMEG-modified TDI prepolymer has two functions: (1) introducing the highly reactive isocyanate groups in TDI into the PTMEG polymer to improve the reactivity; (2) the modified prepolymer retains the flexibility of PTMEG.

[0051] In some preferred embodiments, the crude MDI includes any one of PM200, M20S, and MR200, but is not limited thereto.

[0052] Another aspect of the present invention provides a method for preparing the aforementioned polyurethane anti-stone chip coating, comprising:

[0053] The flame retardant, high resilience polyether polyol, high functionality polyether polyol, and aromatic diol chain extender are mixed and stirred evenly. Then, black colorant, catalyst, and antioxidant are added in sequence, and the mixture is stirred at a speed of 1000-1500 r / min for 10-15 min to obtain the first component.

[0054] Furthermore, the polytetrahydrofuran-modified toluene diisocyanate prepolymer was stirred and mixed evenly with crude MDI to obtain the second component.

[0055] Further, 15.0–25.0 parts of flame retardant, 42.0–52.0 parts of high-resilience polyether polyol, 8.0–12.0 parts of high-functionality polyether polyol, and 15.0–25.0 parts of aromatic diol chain extender are stirred evenly. Then, 0.1–0.2 parts of black colorant, 1.0–2.0 parts of catalyst, and 0.5–1.5 parts of antioxidant are added sequentially. The mixture is stirred at a speed of 1000–1500 r / min for 10–15 minutes to obtain component A (the aforementioned “first component”).

[0056] Further, 20.0-30.0 parts of polytetrahydrofuran modified toluene diisocyanate prepolymer and 70.0-80.0 parts of crude MDI are stirred and mixed evenly to obtain component B (the aforementioned "second component").

[0057] Another aspect of the present invention provides a method for preparing an assembled polyurethane anti-stone impact membrane, comprising:

[0058] Provide the aforementioned polyurethane anti-stone chip coating;

[0059] The first and second components of the polyurethane anti-stone impact coating are heated to 55-65°C, and then poured and demolded to obtain an assembled polyurethane anti-stone impact film.

[0060] Furthermore, the first and second components of the polyurethane anti-stone chip coating are heated to 55-65°C, and then poured into the mold using an elastomer casting machine according to the specified ratio. After cooling and demolding, the resulting coating has a thickness of approximately 1.8-2.2 mm.

[0061] Another aspect of the present invention provides an assembled polyurethane anti-stone impact membrane prepared by the aforementioned preparation method.

[0062] The prefabricated polyurethane anti-stone impact film of the present invention is prefabricated according to the shape of the workpiece to be coated, with a thickness of about 1.8 to 2.2 mm. During assembly, the backing adhesive is brushed on the back of the polyurethane anti-stone impact film, and then it is pressed firmly onto the workpiece.

[0063] Furthermore, the thickness of the assembled polyurethane anti-stone impact membrane is 1.8–2.2 mm.

[0064] Another aspect of the present invention provides the use of the aforementioned polyurethane anti-stone chip coating or assembled polyurethane anti-stone chip film in automobile chassis or wheel mudguards.

[0065] Another aspect of the present invention provides a method for using an assembled polyurethane anti-stone impact membrane, comprising:

[0066] Provide the aforementioned prefabricated polyurethane anti-stone impact membrane;

[0067] Adhesive is applied to the surface of the assembled polyurethane anti-stone impact film, and then one side of the assembled polyurethane anti-stone impact film with adhesive is bonded to the workpiece, thereby realizing the assembly of the assembled polyurethane anti-stone impact film and the workpiece.

[0068] In some preferred embodiments, the adhesive backing includes PU-2020 and / or PU-2117, but is not limited thereto.

[0069] In some preferred embodiments, the workpiece includes, but is not limited to, an automobile chassis.

[0070] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments. These embodiments are implemented on the premise of the technical solution of the invention, and provide detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0071] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0072] The sources of the raw materials used in this invention are shown in Table 1 below:

[0073] Table 1 Raw Material List

[0074]

[0075]

[0076] Example 1

[0077] (1) Component A, by weight, includes: 10.0 parts of flame retardant TCP, 5.0 parts of TCPP, 5.0 parts of TEP, 42.0 parts of high-resilience polyether polyol CHE-632N, 8.0 parts of high-functionality polyether polyol YHY-4110, and 20.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.1 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of SMP, 1.0 parts of SA-800, and 1.0 parts of antioxidant 1076 are added in sequence and mixed. The mixture is stirred at 1200 r / min for 10 minutes to obtain component A.

[0078] Component B, by weight, comprises 100.0 parts of PTMEG1000 and 20.0 parts of PTMEG2000 added to an open reactor, heated to 80°C, adding an appropriate amount of TDI and reacting for 3.0 h, controlling the mass fraction of NCO between 6.0 and 6.4 wt%, cooling to obtain PTMEG-modified TDI prepolymer. 20.0 parts of PTMEG-modified TDI prepolymer and 80.0 parts of crude MDI PM200 are taken and mixed evenly to obtain component B.

[0079] (2) Heat both component A and component B to 55°C, and inject them into the mold in a weight ratio of 2:1 using an elastomer casting machine. Control the thickness to 1.8 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0080] Example 2

[0081] (1) Component A, by weight, includes: 10.0 parts of flame retardant TDCPP, 5.0 parts of TCPP, 5.0 parts of TEP, 45.0 parts of high-resilience polyether polyol NJ-360N, 10.0 parts of high-functionality polyether polyol YHY-4110, and 25.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.2 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of PC-5, 1.0 part of DMCHA, 0.8 parts of antioxidant 1076, and 0.5 parts of antioxidant 168 are added in sequence and mixed. The mixture is stirred at 1500 r / min for 10 minutes to obtain component A.

[0082] Component B, by weight, comprises 90.0 parts of PTMEG1000, 20.0 parts of PTMEG2000, and 5.0 parts of PTMEG3000 added to an open reactor, heated to 85°C, adding an appropriate amount of TDI and reacting for 2.5 hours, controlling the mass fraction of NCO between 5.0 and 5.4 wt%, cooling to obtain a PTMEG-modified TDI prepolymer. 25.0 parts of the PTMEG-modified TDI prepolymer and 75.0 parts of crude MDI M20S are taken and mixed evenly to obtain component B.

[0083] (2) Heat both component A and component B to 60°C, and inject them into the mold in a weight ratio of 2:1 using an elastomer casting machine. Control the thickness to 2.0 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0084] Example 3

[0085] (1) Component A, by weight, includes: 10.0 parts of flame retardant TCEP, 5.0 parts of TCPP, 5.0 parts of TEP, 52.0 parts of high-resilience polyether polyol RT-330N, 12.0 parts of high-functionality polyether polyol INOVOL R8238, and 15.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.1 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of PC-77, 1.0 part of DMCHA, and 1.5 parts of antioxidant 168 are added in sequence and mixed. The mixture is stirred at 1000 r / min for 15 minutes to obtain component A.

[0086] Component B, by weight, comprises 110.0 parts of PTMEG1000 and 5.0 parts of PTMEG2000 added to an open reactor, heated to 90°C, and an appropriate amount of TDI added and reacted for 2.0 h, controlling the mass fraction of NCO between 7.0 and 7.4 wt%. After cooling, a PTMEG-modified TDI prepolymer is obtained. 30.0 parts of the PTMEG-modified TDI prepolymer and 70.0 parts of crude MDI MR200 are taken and mixed evenly to obtain component B.

[0087] (2) Heat both component A and component B to 65°C, and inject them into the mold in a weight ratio of 2:1.1 using an elastomer casting machine. Control the thickness to 2.2 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0088] Comparative Example 1

[0089] (1) Component A, by weight, includes: 10.0 parts of flame retardant TCP, 5.0 parts of TCPP, 5.0 parts of TEP, 42.0 parts of high-resilience polyether polyol CHE-632N, 8.0 parts of high-functionality polyether polyol YHY-4110, and 20.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.1 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of SMP, 1.0 parts of SA-800, and 1.0 parts of antioxidant 1076 are added in sequence and mixed. The mixture is stirred at 1200 r / min for 10 minutes to obtain component A.

[0090] Component B comprises, by weight, 100.0 parts of crude MDI PM200.

[0091] (2) Heat both component A and component B to 55°C, and inject them into the mold in a weight ratio of 2:0.8 using an elastomer casting machine. Control the thickness to 1.8 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0092] Comparative Example 2

[0093] (1) Component A, by weight, includes: 10.0 parts of flame retardant TCP, 5.0 parts of TCPP, 5.0 parts of TEP, 10.0 parts of high-functionality polyether polyol YHY-4110, and 20.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.1 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of SMP, 1.0 parts of SA-800, and 1.0 parts of antioxidant 1076 are added in sequence and mixed. The mixture is stirred at 1200 r / min for 10 minutes to obtain component A.

[0094] Component B, by weight, comprises 100.0 parts of PTMEG1000 and 20.0 parts of PTMEG2000 added to an open reactor, heated to 80°C, adding an appropriate amount of TDI and reacting for 3.0 h, controlling the mass fraction of NCO between 6.0 and 6.4 wt%, cooling to obtain PTMEG-modified TDI prepolymer. 20.0 parts of PTMEG-modified TDI prepolymer and 80.0 parts of crude MDI PM200 are taken and mixed evenly to obtain component B.

[0095] (2) Heat both component A and component B to 55°C, and inject them into the mold in a weight ratio of 3:2 using an elastomer casting machine. Control the thickness to 1.8 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0096] Comparative Example 3

[0097] (1) Component A, by weight, includes: 10.0 parts of flame retardant TCP, 5.0 parts of TCPP, 5.0 parts of TEP, 45.0 parts of high-resilience polyether polyol CHE-632N, and 20.0 parts of aromatic diol chain extender HER-L. The mixture is stirred evenly, and then 0.1 parts of black colorant Y856, 0.3 parts of catalyst A33, 0.5 parts of SMP, 1.0 parts of SA-800, and 1.0 parts of antioxidant 1076 are added in sequence and mixed. The mixture is stirred at 1200 r / min for 10 minutes to obtain component A.

[0098] Component B, by weight, comprises 100.0 parts of PTMEG1000 and 20.0 parts of PTMEG2000 added to an open reactor, heated to 80°C, and TDI added and reacted for 3.0 h, controlling the mass fraction of NCO between 6.0 and 6.4, and then cooled to obtain PTMEG-modified TDI prepolymer. 20.0 parts of PTMEG-modified TDI prepolymer and 80.0 parts of crude MDI PM200 are taken and mixed evenly to obtain component B.

[0099] (2) Heat both component A and component B to 55°C, and inject them into the mold in a weight ratio of 5:3 using an elastomer casting machine. Control the thickness to 1.8 mm, and then cool and demold to obtain a polyurethane anti-stone impact film.

[0100] Table 2 Performance test data of polyurethane anti-stone impact films in Examples 1-3 and Comparative Examples 1-3

[0101]

[0102] Examples 1-3 are polyurethane anti-stone impact films obtained by the present invention, which meet the technical specifications.

[0103] Comparative Example 1 is the same as Example 1, except that the polyurethane anti-stone impact film prepared in Example 1 uses crude MDI as the curing agent, without the addition of PTMEG-modified TDI prepolymer. The test data shows that using only crude MDI increases the film strength but also its brittleness, and the film's anti-stone impact performance deteriorates at low temperatures. Adding PTMEG-modified TDI prepolymer increases the film's flexibility.

[0104] Comparative Example 2 is the same as Example 1, except that the raw materials used in the polyurethane anti-stone impact film prepared in Example 1 lacked high-resilience polyether polyol. The test data shows that the entire coating is very brittle, which is due to the lack of high-resilience polyether polyol, resulting in a high crosslinking density and poor impact resistance of the hard coating.

[0105] Comparative Example 3 is the same as Example 1, except that the polyurethane anti-stone chip film prepared in Example 1 lacks high-functionality polyether polyol in its raw materials. The test data shows that the entire coating is relatively soft, which is due to the low crosslinking density and poor resistance to the medium. High-functionality polyether polyol has high reactivity and a functionality of 4-6; adding it to the formulation can make the surface smooth and non-sticky, and improve the crosslinking density.

[0106] Example 4

[0107] The polyurethane anti-stone impact film prepared in Example 1 was brushed with PU-2117 adhesive and attached to the car chassis.

[0108] Comparative Example 4

[0109] The PVC anti-stone chip coating, which is made in imitation of patent ZL201910023650.0, is sprayed onto the chassis of a car.

[0110] Table 3 Comparison data between Example 4 and Comparative Example 4

[0111] name Example 4 Comparative Example 4 Substrate treatment methods Dust removal and oil removal Dust removal, oil removal, and masking. Construction method Apply adhesive and stick. Press-plate spraying machine spraying Drying conditions Leave at room temperature for 24 hours Bake at 140℃ for 30 minutes Material loss Lossless At least 5% loss Adhesion (bare aluminum) Cohesion destruction Interlayer failure

[0112] As can be seen from the table above, the pre-fabricated polyurethane anti-stone impact membrane of this invention is simple and convenient to install on automobile chassis, and the quality is guaranteed.

[0113] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0114] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A polyurethane anti-stone chip coating, characterized in that: The polyurethane anti-stone chip coating comprises a first component and a second component; The first component includes the following components: black colorant, catalyst, antioxidant, flame retardant, aromatic diol chain extender, high-resilience polyether polyol and high-functionality polyether polyol; the second component includes polytetrahydrofuran modified toluene diisocyanate prepolymer and crude MDI. The high-resilience polyether polyol has a hydroxyl value of 25-35 mgKOH / g, a viscosity of 800-1500 MPa•s, and a functionality of 2-4; the high-functionality polyether polyol has a hydroxyl value of 380-500 mgKOH / g and a functionality of 4-6. The preparation method of the polytetrahydrofuran modified toluene diisocyanate prepolymer includes: reacting polytetrahydrofuran and toluene diisocyanate at 80-90°C to obtain the polytetrahydrofuran modified toluene diisocyanate prepolymer.

2. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The first component comprises the following components by weight: 0.1-0.2 parts of black colorant, 1.0-2.0 parts of catalyst, 0.5-1.5 parts of antioxidant, 15.0-25.0 parts of flame retardant, 15.0-25.0 parts of aromatic diol chain extender, 42.0-52.0 parts of high-resilience polyether polyol and 8.0-12.0 parts of high-functionality polyether polyol.

3. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The second component comprises the following components in parts by weight: 20.0 to 30.0 parts of polytetrahydrofuran modified toluene diisocyanate prepolymer and 70.0 to 80.0 parts of crude MDI.

4. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The mass ratio of the first component to the second component is 2:1 to 1.

1.

5. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The black colorant includes black dye and organic solvent; the solid content of the black colorant is 5-35 wt%; the black colorant includes Y856 black colorant.

6. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The catalyst includes any two or more combinations of catalyst A33, catalyst SMP, catalyst SA-800, catalyst PC-5, catalyst PC-77, and catalyst DMCHA.

7. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The antioxidants include antioxidant 1076 and / or antioxidant 168.

8. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The flame retardant includes phosphate ester liquid flame retardants.

9. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The flame retardant includes any one or a combination of two or more of the following: TCP flame retardant, TCPP flame retardant, TEP flame retardant, TDCPP flame retardant, and TCEP flame retardant.

10. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The aromatic diol chain extender has a hydroxyl value of 400-500 mgKOH / g; and / or, the aromatic diol chain extender includes the chain extender HER-L.

11. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The polytetrahydrofuran includes any one or a combination of two or more of PTMEG1000, PTMEG2000, and PTMEG3000.

12. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The mass fraction of NCO in the polytetrahydrofuran-modified toluene diisocyanate prepolymer is controlled between 5 and 8 wt%.

13. The polyurethane anti-stone chip coating according to claim 1, characterized in that: The crude MDI includes any one of PM200, M20S, and MR200.

14. The method for preparing the polyurethane anti-stone chip coating according to any one of claims 1-13, characterized in that, include: The flame retardant, high resilience polyether polyol, high functionality polyether polyol, and aromatic diol chain extender are mixed and stirred evenly. Then, black colorant, catalyst, and antioxidant are added in sequence, and the mixture is stirred at a speed of 1000-1500 r / min for 10-15 min to obtain the first component. Furthermore, the polytetrahydrofuran-modified toluene diisocyanate prepolymer was stirred and mixed evenly with crude MDI to obtain the second component.

15. A method for preparing an assembled polyurethane anti-stone impact membrane, characterized in that, include: Provide a polyurethane anti-stone chip coating according to any one of claims 1-13; The first and second components of the polyurethane anti-stone impact coating are heated to 55-65°C, and then poured and demolded to obtain an assembled polyurethane anti-stone impact film.

16. An assembled polyurethane anti-stone impact membrane prepared by the preparation method of claim 15; wherein the thickness of the assembled polyurethane anti-stone impact membrane is 1.8 to 2.2 mm.

17. Use of the polyurethane anti-stone impact coating of any one of claims 1-13 or the assembled polyurethane anti-stone impact film of claim 16 in automobile chassis or wheel mudguards.

18. A method for using a prefabricated polyurethane anti-stone impact membrane, characterized in that, include: Provide the assembled polyurethane anti-stone impact membrane as described in claim 16; Adhesive is applied to the surface of the assembled polyurethane anti-stone impact film, and then one side of the assembled polyurethane anti-stone impact film with adhesive is bonded to the workpiece, thereby realizing the assembly of the assembled polyurethane anti-stone impact film and the workpiece.

19. The method of use according to claim 18, characterized in that: The workpiece includes an automobile chassis.

Images