Engine cover polyurethane material with self-demolding function as well as preparation method and application of engine cover polyurethane material

Abstract

The invention provides an engine cover polyurethane material with a self-demolding function as well as a preparation method and application thereof. The material is prepared from polyurethane base resin, a self-demolding additive, a color regulator, a catalytic system, filler, a plasticizer, a flame retardant, an anti-aging agent, a modified material and other auxiliaries, the preparation method comprises the steps of mixing, pouring, curing, demolding, post-processing and the like. Wherein the self-demolding additive can migrate to the surface of the material in the curing process to form a self-demolding film, and the color regulator realizes material coloring without additional spraying. The material has excellent mechanical strength, heat resistance and colorability, and is especially suitable for manufacturing automobile engine covers. The preparation method is simple and efficient, the production efficiency can be remarkably improved, the production cost is reduced, and the product is attractive, durable and excellent in environmental protection performance. The polyurethane material provided by the invention provides a new high-performance material choice for the automobile part industry.

Description

Technical Field

[0001] The invention belongs to the field of novel automobile materials, and specifically discloses an engine hood polyurethane material with a self-demolding function, a preparation method and an application thereof. Background Art

[0002] In the prior art, the engine hood is an important part of the automobile, and its material selection and preparation process have an important impact on the overall performance and appearance quality of the automobile. Traditional engine hood materials are mostly made of metal materials, such as steel plates, etc. Although they have certain mechanical strength and heat resistance, they have defects such as heavy weight, easy corrosion, high processing cost, and difficulty in forming complex shapes. With the development trend of lightweight and environmentally friendly automobiles, non-metallic materials, especially polyurethane materials, have gradually become ideal alternative materials for engine hoods.

[0003] However, existing polyurethane engine hood materials still have some obvious technical defects in the preparation and application process. On the one hand, traditional polyurethane materials often adhere tightly to the mold after curing, making demoulding difficult and requiring additional release agents or complex demoulding processes, which not only increases production costs but may also have an adverse effect on the surface quality of the product. On the other hand, the coloring of polyurethane materials usually needs to be achieved through a subsequent spray painting process, which not only increases the production process, but may also burden the environment due to paint volatilization and pollution problems.

[0004] In addition, the existing polyurethane engine hood materials still need to be improved in terms of mechanical strength and heat resistance to meet the high performance requirements of automobiles in different use environments. At the same time, the modification of polyurethane materials and the optimization of processing properties are also issues that need to be urgently addressed.

[0005] In summary, the prior art lacks an engine hood polyurethane material having self-demolding function, easy coloring, high mechanical strength, good heat resistance and excellent processing performance and a preparation method thereof. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides an engine hood polyurethane material with a self-demolding function, and a preparation method and application thereof.

[0007] The present invention includes the following technical solutions:

[0008] A polyurethane material for an engine hood with a self-demolding function, made from the following raw materials in parts by weight:

[0009] Polyurethane base resin: 80-120 parts,

[0010] Selected from polyether type, polyester type or their mixture as the main component of polyurethane material;

[0011] Self-release additives: 1-10 parts,

[0012] The additive is a compound or mixture with a self-release function, which can migrate to the surface of the material during the curing process of the polyurethane material to form a film with a self-release effect;

[0013] Color regulator: 0.5-15 parts,

[0014] The regulator is a pigment, dye or a mixture thereof that is compatible with the polyurethane material and is used to achieve the coloring of the polyurethane material without the need for additional spraying of paint;

[0015] Catalytic system: 0.1-8 parts,

[0016] It includes at least one catalyst for adjusting the reaction speed and curing time of the polyurethane material so that the material can be cured evenly and quickly in the mold;

[0017] Filler: 1-10 parts,

[0018] Selected from inorganic or organic fillers, including but not limited to talc, calcium carbonate, wollastonite, glass fiber, used to improve the mechanical strength and heat resistance of polyurethane materials;

[0019] Plasticizer: 1-5 parts,

[0020] Used to improve the processing performance and flexibility of polyurethane materials, making them easier to form in molds;

[0021] Flame retardant: 1-5 parts,

[0022] Used to improve the flame retardant properties of polyurethane materials;

[0023] Anti-aging agent: 1-5 parts,

[0024] Used to extend the service life of polyurethane materials and improve their weather resistance and chemical corrosion resistance;

[0025] Modified materials: 1-10 parts,

[0026] Selected from polymer materials such as rubber, plastic, elastomer or mixtures thereof, used to modify polyurethane materials to improve elasticity, wear resistance and impact resistance;

[0027] Other additives: appropriate amount, including but not limited to leveling agent and defoamer, used to improve the processing performance of polyurethane materials and the appearance quality of the final product.

[0028] Furthermore, in the above-mentioned engine hood polyurethane material with self-demolding function, the self-demolding additive is selected from fatty acid amide compounds, silicone compounds or their mixtures; wherein the fatty acid amide compounds include but are not limited to stearic acid amide, vinyl bisstearamide, and the silicone compounds include but are not limited to polydimethylsiloxane and silicone oil.

[0029] Furthermore, in the above-mentioned engine hood polyurethane material with self-demolding function, the color regulator is a high temperature resistant and UV resistant pigment or dye, including but not limited to titanium dioxide, iron red, carbon black or a combination thereof.

[0030] Furthermore, in the above-mentioned engine hood polyurethane material with self-demolding function, the catalytic system includes at least one amine catalyst and / or organic metal catalyst, including but not limited to dimethylethanolamine, triethylamine, and dibutyltin dilaurate.

[0031] Furthermore, in the above-mentioned polyurethane material for an engine hood with a self-demolding function, the filler is a nano-scale filler, including but not limited to nano-silicon dioxide and nano-calcium carbonate.

[0032] Furthermore, in the above-mentioned polyurethane material for an engine hood with a self-demolding function, the plasticizer is selected from polyester plasticizers, epoxy plasticizers or mixtures thereof.

[0033] Furthermore, in the above-mentioned polyurethane material for the engine hood with self-demolding function, the flame retardant is a halogen-free flame retardant.

[0034] Furthermore, in the above-mentioned engine hood polyurethane material with self-demolding function, the anti-aging agent includes but is not limited to hindered phenol anti-aging agents, light stabilizers or a combination thereof.

[0035] The present invention also discloses a method for preparing the polyurethane material of the engine cover with self-demolding function, comprising the following steps:

[0036] S1 Mixing: Put the polyurethane base resin, self-release additives, color regulator, catalyst system, filler, plasticizer, flame retardant, anti-aging agent, modified material and other additives into the mixing equipment, and stir them fully until the components are evenly dispersed to form a mixed material;

[0037] S2 Pouring: Pour the evenly mixed material into a mold preheated to a set temperature to ensure that the material is evenly distributed in the mold;

[0038] S3 curing: Under the set temperature and time conditions, the polyurethane material is cured in the mold, during which the self-release additive will migrate to the surface of the material to form a film with a self-release effect;

[0039] S4 demoulding: After the polyurethane material is completely cured, the polyurethane material of the engine hood cover can be easily removed from the mold by using the characteristics of the self-release film;

[0040] S5 post-processing: perform necessary post-processing on the demoulding polyurethane material, including trimming the edges and inspecting the quality, to obtain the final engine hood polyurethane material product with self-demolding function.

[0041] Furthermore, the present invention discloses the application of the above material in manufacturing automobile engine hoods.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention discloses a polyurethane material for an engine hood with a self-demolding function, and a preparation method and application thereof. The present invention successfully organically integrates multiple components such as self-demolding additives, color regulators, high-efficiency catalytic systems, reinforcing fillers, plasticizers, environmentally friendly flame retardants, anti-aging agents, and modified materials, which not only gives the polyurethane material the convenient characteristic of self-demolding, but also makes the demoulding process smoother, without the need for additional demoulding agents, greatly reducing production costs and improving production efficiency; at the same time, the direct addition of color regulators realizes instant coloring of the material, eliminating the cumbersome steps of traditional spraying paint, reducing environmental pollution, and ensuring the uniformity and durability of product color. In addition, the polyurethane material of the present invention performs well in mechanical strength and heat resistance, and fully meets the stringent requirements of automobile engine hoods in complex and changeable use environments. The clever use of plasticizers further improves the processing performance of the material, making the molding more precise and stable, and the selection of environmentally friendly flame retardants and anti-aging agents highlights the profound consideration of the present invention for environmental protection. In summary, the present invention significantly improves the comprehensive performance and production efficiency of the polyurethane material for the engine hood. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Comparison of demoulding time (s) of test cases;

[0045] Figure 2 Comparison of demoulding force (N) of test cases;

[0046] Figure 3 Comparison of tensile strength (Mpa) of test cases;

[0047] Figure 4 Comparison of test case flexural strength (Mpa);

[0048] Figure 5 Test case Impact toughness (kJ / m 2 ) comparison. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Embodiment 1:

[0051] A polyurethane material for an engine hood with a self-demolding function, the specific preparation process of which is as follows:

[0052] Raw material formula (weight parts):

[0053] Polyurethane base resin: 100 parts (polyether polyol PPG-2000)

[0054] Self-release additive: 5 parts (stearic acid amide)

[0055] Color regulator: 8 parts (titanium dioxide, model R-902)

[0056] Catalytic system: 3 parts (dimethylethanolamine)

[0057] Filler: 5 parts (nano silicon dioxide, particle size 20nm)

[0058] Plasticizer: 3 parts (polyester plasticizer, model DOTP)

[0059] Flame retardant: 2 parts (halogen-free flame retardant, type Al(OH))

[0060] Anti-aging agent: 2 parts (hindered phenol antioxidant, model BHT)

[0061] Modified material: 5 parts (styrene-butadiene rubber particles, particle size 1 mm)

[0062] Other additives: appropriate amount (leveling agent BYK-333 and defoamer Defoamer-A)

[0063] Preparation method:

[0064] S1 Premix:

[0065] Add 100 parts of polyether polyol PPG-2000, 5 parts of stearic acid amide, 8 parts of titanium dioxide R-902, 5 parts of nano-silica, 3 parts of polyester plasticizer DOTP, 2 parts of halogen-free flame retardant Al(OH), 2 parts of hindered phenol anti-aging agent BHT, 5 parts of styrene-butadiene rubber particles and appropriate amounts of leveling agent BYK-333 and defoamer Defoamer-A into a high-speed mixer.

[0066] The mixer runs at an appropriate speed to ensure that all ingredients are evenly mixed to form a premix.

[0067] S2 catalytic addition:

[0068] Add 3 parts of dimethylethanolamine to the premix and continue mixing until the catalyst system is evenly distributed.

[0069] S3 Melt Treatment:

[0070] The mixed materials are fed into a melt extruder and the temperature is set at 180-220°C to fully melt the materials.

[0071] S4 Injection Molding:

[0072] The molten material is injected into the engine cover mold through the injection molding machine, and the pressure is maintained for 30-60 seconds to ensure that the material completely fills the mold and initially solidifies.

[0073] S5 post-processing:

[0074] Take out the injection-molded engine hood cover and cool it to room temperature.

[0075] Trim the product to remove excess burrs and flash.

[0076] Example 2

[0077] Raw material formula (weight parts):

[0078] Polyurethane base resin: 80 parts (polyester polyol PET-3000)

[0079] Self-release additive: 1 part (polydimethylsiloxane, viscosity 500cSt)

[0080] Color regulator: 0.5 parts (iron red pigment, model Red Iron Oxide)

[0081] Catalytic system: 0.1 parts (triethylamine)

[0082] Filler: 1 part (talcum powder, particle size 325 mesh)

[0083] Plasticizer: 1 part (epoxidized soybean oil, type ESBO)

[0084] Flame retardant: 1 part (halogen-free flame retardant, type Mg(OH))

[0085] Anti-aging agent: 1 part (light stabilizer, model UV-531)

[0086] Modified material: 1 part (polyethylene granules, melt index 2g / 10min)

[0087] Other additives: appropriate amount (leveling agent BYK-306)

[0088] Preparation method:

[0089] The preparation was carried out in the same manner according to the steps from S1 to S5 of Example 1, with the specific conditions slightly adjusted according to the characteristics of the raw materials.

[0090] Example 3

[0091] Raw material formula (weight parts):

[0092] Polyurethane base resin: 120 parts (polyether-polyester copolymer polyol, model PE-PO 4000)

[0093] Self-release additive: 10 parts (vinyl bisstearamide)

[0094] Color regulator: 15 parts (carbon black, model N330)

[0095] Catalytic system: 8 parts (mixture of dimethylethanolamine and dibutyltin diacetate, ratio 2:1)

[0096] Filler: 10 parts (calcium carbonate, particle size 10 μm)

[0097] Plasticizer: 5 parts (polyester plasticizer, model DINP)

[0098] Flame retardant: 5 parts (halogen-free flame retardant, model phosphorus flame retardant FR-P)

[0099] Anti-aging agent: 5 parts (hindered phenol anti-aging agent and light stabilizer mixture, model BHT: UV-327 = 1:1) Modified material: 10 parts (EPDM rubber particles, particle size 2mm)

[0100] Other additives: appropriate amount (defoamer-B)

[0101] Preparation method:

[0102] Prepare according to steps S1 to S5, paying attention to the mixing ratio of the catalyst system and the selection of the plasticizer.

[0103] Example 4

[0104] Raw material formula (weight parts):

[0105] Polyurethane base resin: 90 parts (polyether polyol PPG-1000)

[0106] Self-release additive: 3 parts (silicone oil, model Silicone Oil 200)

[0107] Color regulator: 5 parts (phthalocyanine blue pigment, model PB15:3)

[0108] Catalytic system: 2 parts (dimethylethanolamine)

[0109] Filler: 3 parts (wollastonite, particle size 5 μm)

[0110] Plasticizer: 2 parts (epoxy plasticizer, model EPO)

[0111] Flame retardant: 3 parts (halogen-free flame retardant, model ATH, i.e. bauxite)

[0112] Anti-aging agent: 3 parts (hindered phenol antioxidant, model 1010)

[0113] Modified material: 3 parts (polyurethane elastomer particles, Shore hardness 80A)

[0114] Other additives: appropriate amount (leveling agent BYK-358 and defoamer Defoamer-C)

[0115] Preparation method:

[0116] Prepare according to steps S1 to S5, paying attention to the dispersibility of the pigment and the amount of plasticizer used.

[0117] Example 5

[0118] Raw material formula (weight parts):

[0119] Polyurethane base resin: 110 parts (polyester polyol PET-2000)

[0120] Self-release additive: 7 parts (calcium stearate)

[0121] Color regulator: 10 parts (yellow pigment, model Yellow Oxide)

[0122] Catalytic system: 5 parts (mixture of dimethylethanolamine and triethylamine, ratio 1:1)

[0123] Filler: 7 parts (glass fiber, length 3mm)

[0124] Plasticizer: 4 parts (polyester plasticizer, model DEHP)

[0125] Flame retardant: 4 parts (halogen-free flame retardant, model MEL, i.e. melamine cyanurate)

[0126] Anti-aging agent: 4 parts (light stabilizer, type UV-P)

[0127] Modified material: 7 parts (ethylene-vinyl acetate copolymer particles, melt index 5g / 10min)

[0128] Other additives: appropriate amount (leveling agent BYK-378 and defoamer Defoamer-D)

[0129] Preparation method:

[0130] The preparation is carried out according to steps S1 to S5, with particular attention paid to the dispersion of glass fibers and the synergistic effect of the catalyst system.

[0131] Comparative Example 1

[0132] No self-release additive is contained, and the other parts are the same as those in Example 1.

[0133] Comparative Example 2

[0134] It does not contain the catalyst system and the modified material, and the rest is the same as Example 1.

[0135] Comparative Example 3

[0136] No filler or plasticizer is contained, and the other parts are the same as those in Example 1.

[0137] Comparative Example 4

[0138] Commercially available common polyurethane material.

[0139] Test Example 1

[0140] Self-release performance test of embodiments and comparative examples

[0141] Test purpose: To verify the effectiveness of self-release additives and the smoothness of demoulding.

[0142] Test method:

[0143] After curing, the time and force required to release from the mold were recorded to compare the ease of demoulding.

[0144] Observe and record the integrity and uniformity of the self-release film on the sample surface. The results are shown in Table 1 and Figure 1-2 shown.

[0145] Table 1 Self-release performance test of embodiments and comparative examples

[0146] Demolding time(s) Demolding force (N) Film integrity and uniformity Example 1 124 245 Complete and uniform Example 2 128 253 Complete and uniform Example 3 131 249 Complete and uniform Example 4 136 229 Complete and uniform Example 5 141 235 Complete and uniform Comparative Example 1 176 325 Incomplete and uneven Comparative Example 2 152 274 Complete, uneven Comparative Example 3 136 251 Complete and uniform Comparative Example 4 212 433 Complete, uneven

[0147] It can be seen from the data in Table 1 that the polyurethane engine hood prepared using the formula of the present invention can significantly shorten the demolding time and demolding force while maintaining the integrity and uniformity of the self-release film on the sample surface.

[0148] Test Example 2

[0149] Test purpose: To evaluate the tensile strength, flexural strength and impact toughness of polyurethane materials.

[0150] Test method:

[0151] The test specimens were prepared according to the standard test method (ASTM D638).

[0152] The tensile strength and flexural strength of the samples were tested using a universal testing machine, and the impact toughness of the samples was tested using an impact testing machine.

[0153] Compare the test results of the samples, the results are shown in Table 2 and Figure 3-5 shown.

[0154] Table 2 Mechanical properties test of embodiments and comparative examples

[0155]

[0156]

[0157] From the data in Table 2, it can be seen that the polyurethane material disclosed in the present invention has good mechanical properties, and the addition of the self-release additive in the present invention does not affect the mechanical properties. From the comparison between Example 1 and Comparative Examples 2-4, it can be seen that the modified material, filler and plasticizer in the present invention can greatly increase the mechanical properties of the material.

[0158] Test Example 3

[0159] Color stability test

[0160] Test purpose: To evaluate the high temperature resistance, UV resistance and color durability of color regulators.

[0161] Test method:

[0162] The samples were placed under high temperature of 80°C and UV irradiation conditions (UVA band: 320-400 nm, 0.68 W / m 2 ) to simulate an accelerated long-term usage environment.

[0163] Check and record color changes of samples, including fading, discoloration, etc.

[0164] The results are shown in Table 3.

[0165] Table 3 Color stability test

[0166]

[0167]

[0168] From the results in Table 3, it can be seen that after long-term high temperature and ultraviolet irradiation, the color of the sample of the present invention remains stable without obvious fading or discoloration, which proves that the color in the polyurethane material of the present invention has good high temperature resistance and ultraviolet resistance.

[0169] It can be seen from the above embodiments that the present invention successfully integrates multiple components such as self-demolding additives, color regulators, high-efficiency catalytic systems, reinforcing fillers, plasticizers, environmentally friendly flame retardants, anti-aging agents and modified materials, which not only gives the polyurethane material the convenient self-demolding characteristics, but also makes the demoulding process smoother, without the need for additional demoulding agents, greatly reducing production costs and improving production efficiency; at the same time, the direct addition of color regulators realizes the instant coloring of materials, eliminating the cumbersome steps of traditional spraying paint, reducing environmental pollution, and ensuring the uniformity and durability of product colors. In addition, the polyurethane material of the present invention performs well in mechanical strength and heat resistance, and fully meets the stringent requirements of automobile engine hoods in complex and changeable use environments. The clever use of plasticizers further improves the processing performance of the material, making the molding more precise and stable, and the selection of environmentally friendly flame retardants and anti-aging agents highlights the profound consideration of the present invention for environmental protection. In summary, the present invention significantly improves the comprehensive performance and production efficiency of the engine hood polyurethane material.

[0170] The above are limited to several preferred embodiments of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A polyurethane material for an engine hood with a self-demolding function, characterized in that: Made from the following raw materials in parts by weight: Polyurethane base resin: 80-120 parts, Selected from polyether type, polyester type or their mixture as the main component of polyurethane material; Self-release additives: 1-10 parts, The additive is a compound or mixture with a self-release function, which can migrate to the surface of the material during the curing process of the polyurethane material to form a film with a self-release effect; Color regulator: 0.5-15 parts, The regulator is a pigment, dye or a mixture thereof that is compatible with the polyurethane material and is used to achieve the coloring of the polyurethane material without the need for additional spraying of paint; Catalytic system: 0.1-8 parts, It includes at least one catalyst for adjusting the reaction speed and curing time of the polyurethane material so that the material can be cured evenly and quickly in the mold; Filler: 1-10 parts, Selected from inorganic or organic fillers, including but not limited to talc, calcium carbonate, wollastonite, glass fiber, used to improve the mechanical strength and heat resistance of polyurethane materials; Plasticizer: 1-5 parts, Used to improve the processing performance and flexibility of polyurethane materials, making them easier to form in molds; Flame retardant: 1-5 parts, Used to improve the flame retardant properties of polyurethane materials; Anti-aging agent: 1-5 parts, Used to extend the service life of polyurethane materials and improve their weather resistance and chemical corrosion resistance; Modified materials: 1-10 parts, Selected from polymer materials such as rubber, plastic, elastomer or mixtures thereof, used to modify polyurethane materials to improve elasticity, wear resistance and impact resistance; Other additives: appropriate amount, including but not limited to leveling agent and defoamer, used to improve the processing performance of polyurethane materials and the appearance quality of the final product.

2. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The self-release additive is selected from fatty acid amide compounds, silicone compounds or mixtures thereof; wherein the fatty acid amide compounds include but are not limited to stearic acid amide and vinyl bisstearamide, and the silicone compounds include but are not limited to polydimethylsiloxane and silicone oil.

3. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The color regulator is a high temperature resistant and ultraviolet resistant pigment or dye, including but not limited to titanium dioxide, iron oxide red, carbon black or a combination thereof.

4. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The catalytic system includes at least one amine catalyst and / or organic metal catalyst, including but not limited to dimethylethanolamine, triethylamine, and dibutyltin dilaurate.

5. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The filler is a nano-scale filler, including but not limited to nano-silicon dioxide and nano-calcium carbonate.

6. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The plasticizer is selected from polyester plasticizer, epoxy plasticizer or a mixture thereof.

7. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The flame retardant is a halogen-free flame retardant.

8. The polyurethane material for an engine cover having a self-release function according to claim 1, characterized in that: The anti-aging agent includes, but is not limited to, hindered phenol anti-aging agents, light stabilizers or a combination thereof.

9. The method for preparing the polyurethane material for an engine cover with a self-release function according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1 Mixing: Put the polyurethane base resin, self-release additives, color regulator, catalyst system, filler, plasticizer, flame retardant, anti-aging agent, modified material and other additives into the mixing equipment, and stir them fully until the components are evenly dispersed to form a mixed material; S2 Pouring: Pour the evenly mixed material into a mold preheated to a set temperature to ensure that the material is evenly distributed in the mold; S3 curing: Under the set temperature and time conditions, the polyurethane material is cured in the mold, during which the self-release additive will migrate to the surface of the material to form a film with a self-release effect; S4 demoulding: After the polyurethane material is completely cured, the polyurethane material of the engine hood cover can be easily removed from the mold by using the characteristics of the self-release film; S5 post-processing: perform necessary post-processing on the demoulding polyurethane material, including trimming the edges and inspecting the quality, to obtain the final engine hood polyurethane material product with self-demolding function.

10. Use of the material according to any one of claims 1 to 8 in manufacturing automobile engine hoods.

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