An SMC material for a truck bed with high impact resistance and aging resistance and its preparation method

Abstract

The present invention provides an SMC material for a truck bed with high impact resistance and aging resistance, and a preparation method thereof. By selecting different unsaturated polyester resins and applying them to the systems of phenolic vinyl resin and epoxy vinyl resin, the prepared SMC material and its molded products have high impact toughness, high heat resistance and extremely high chemical corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the field of composite materials for vehicle beds, and particularly relates to an SMC material for vehicle beds with high impact resistance and aging resistance, and a preparation method thereof. Background Art

[0002] Sheet Molding Compound (SMC) is a thermosetting fiberglass molding composite material, which is the most common form of fiber-reinforced plastics. The comprehensive performance of the composite material is improved by the combination of fibers and resins. SMC materials usually use thermosetting resins as the main raw materials, and thickeners, mold release agents, fillers and other additives are added thereto, and glass fibers and the like are added to produce SMC materials with different properties. According to the different properties of SMC materials, they can be applied to many industries, such as vehicles, construction, electronics and other industries. For vehicles, according to the performance requirements of different components, they can be further divided into automotive exterior covers, engine protection plates, vehicle beds, and so on.

[0003] With the rapid development of global electric vehicles, pickups built on pure electric platforms have also developed rapidly. Due to the characteristics of pure electric vehicles, it is necessary to significantly reduce the weight of the carriage. Therefore, SMC materials have gradually replaced traditional sheet metal materials and become the main materials for the rear beds of pickups.

[0004] Patent CN114350131B discloses an SMC material for pickup beds. It mainly adds a scratch-resistant agent to the SMC material for pickup beds, so that the degree of change in the surface brightness of the material after scratching is small, which facilitates the use of pickup products. At the same time, a quick-setting composite reagent is added to the SMC material for pickup beds, which can greatly shorten the curing time of the material and improve production efficiency. However, since the vehicle beds of pickups are often exposed outdoors, they have relatively high requirements for high temperature resistance / aging resistance. The vehicle beds often carry various goods and have relatively high requirements for impact resistance, corrosion resistance, etc. The above patent does not solve the requirements in aspects such as high temperature resistance and corrosion resistance, and there is still room for improvement in terms of impact resistance. Summary of the Invention

[0005] The present invention provides an SMC material for vehicle beds with high impact resistance and aging resistance, which has advantages such as high impact resistance / impact toughness, aging resistance (especially good heat resistance), and strong corrosion resistance (especially extremely strong chemical corrosion resistance to sulfuric acid, alcohol, diesel, brake fluid, coolant, brine, etc.).

[0006] The present invention provides an SMC material, which comprises any one or more of phenolic vinyl resin, epoxy vinyl resin, unsaturated polyester resin, corrosion-resistant plastic additives, curing agents, mold release agents, ceramic micro-powders, alumina micro-powders, thickeners, and glass fibers.

[0007] In the present invention, the unsaturated polyester resin is selected from isophthalic neopentyl glycol unsaturated polyester resin, phthalic neopentyl glycol unsaturated polyester resin, terephthalic neopentyl glycol unsaturated polyester resin or isophthalic propylene glycol unsaturated polyester resin, preferably isophthalic neopentyl glycol unsaturated polyester resin;

[0008] In the present invention, the corrosion-resistant plastic auxiliary is selected from one or both of PE powder and polytetrafluoroethylene micro powder;

[0009] In the present invention, the curing agent is selected from one or both of tert-butyl peroxybenzoate and diisopropylbenzene peroxide, preferably tert-butyl peroxybenzoate;

[0010] In the present invention, the mold release agent is selected from one or both of zinc stearate and calcium stearate, preferably zinc stearate;

[0011] In the present invention, the thickening agent is selected from one or several of magnesium oxide, calcium oxide, magnesium hydroxide and calcium hydroxide, preferably magnesium oxide;

[0012] In the present invention, the glass fiber is selected from glass fibers (non-alkali chopped) of 10 - 30 mm, preferably 25 mm;

[0013] In the present invention, the SMC material comprises 4 - 10 parts by weight of phenolic vinyl resin;

[0014] And / or,

[0015] In the present invention, the SMC material comprises 4 - 10 parts by weight of epoxy vinyl resin;

[0016] And / or,

[0017] In the present invention, the SMC material comprises 4 - 20 parts by weight of unsaturated polyester resin, preferably 5 - 20 parts by weight, more preferably 10 - 15 parts by weight;

[0018] And / or,

[0019] In the present invention, the SMC material comprises 6 - 20 parts by weight of corrosion-resistant plastic auxiliary; preferably comprises 3 - 10 parts by weight of PE powder, and / or comprises 3 - 10 parts by weight of polytetrafluoroethylene micro powder;

[0020] And / or,

[0021] In the present invention, the SMC material comprises 0.3 - 2 parts by weight of curing agent;

[0022] And / or,

[0023] In the present invention, the SMC material comprises 1 - 3 parts by weight of mold release agent;

[0024] And / or,

[0025] In the present invention, the SMC material comprises 10-20 parts by weight of ceramic micro-powder;

[0026] and / or,

[0027] In the present invention, the SMC material comprises 10-20 parts by weight of alumina micro-powder;

[0028] and / or,

[0029] In the present invention, the SMC material comprises 1-5 parts by weight of thickener;

[0030] and / or,

[0031] In the present invention, the SMC material comprises 40-60 parts by weight of glass fiber;

[0032] In the SMC material of the present invention, the weight ratio of phenolic vinyl resin, epoxy vinyl resin, and unsaturated polyester resin can be 1:1:0.5-2, preferably 1:1:1-1.5;

[0033] The present invention also provides a method for preparing an SMC material, comprising the following steps:

[0034] 3) Mix phenolic vinyl resin, epoxy vinyl resin, unsaturated polyester resin, corrosion-resistant plastic auxiliary, curing agent, release agent, ceramic micro-powder, and alumina micro-powder evenly, and then add thickener and mix evenly to obtain resin paste;

[0035] 4) Coat the resin paste on the upper and lower two polyethylene films, evenly deposit glass fiber on the resin paste, and roll, wind, and cure the lower film carrying the fiber and the upper film to obtain the SMC material;

[0036] In the present invention, the temperature of the curing is 40-60°C, preferably 50°C;

[0037] In the present invention, the time of the curing is 12-48 h, preferably 24 h.

[0038] By selecting different unsaturated polyester resins and applying them to the systems of phenolic vinyl resin and epoxy vinyl resin, the SMC material and its molded products prepared in the present invention have high impact toughness. Among them, using isophthalic neopentyl glycol unsaturated polyester resin as the unsaturated polyester resin has the best effect, and the usage amount or ratio of isophthalic neopentyl glycol unsaturated polyester resin will also affect the impact toughness performance; the SMC material and its molded products of the present invention have high heat resistance and have no deformation / slight deformation and no cracking under the test conditions of 250°C; in addition, the SMC material and its molded products of the present invention have extremely high chemical corrosion resistance and have good tolerance to sulfuric acid, alcohol, diesel, brake fluid, coolant, brine, etc. Detailed implementation manners

[0039] Example 1

[0040] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 Isophthalic neopentyl glycol unsaturated polyester resin 10 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0041] In a high-speed shear mixer (1500 r / min), phenolic vinyl resin, epoxy vinyl resin, isophthalone neopentyl glycol unsaturated polyester resin, PE powder, polytetrafluoroethylene micro powder, tert-butyl perbenzoate, zinc stearate, ceramic micro powder, alumina micro powder, and alumina micro powder were sequentially added according to the weight ratio, and mixed and stirred for 8 min. Then, magnesium oxide was added and stirring was continued for 10 min while controlling the system temperature not to exceed 45 °C to form a resin paste.

[0042] The resin paste was poured onto the upper and lower rubber tables of an SMC compounding machine. The compounding machine was started, and the upper and lower base polyethylene films were unrolled. The scrapers on the upper and lower rubber tables uniformly coated the resin paste on the upper and lower base polyethylene films. When the PET film on the lower rubber table passed through the fiber sedimentation area, glass fibers (25 mm) were uniformly sedimented on the resin composition, and the mass ratio of fiber to resin paste was controlled to be 60:67. The lower film carrying the fiber and the upper film passed through the pressure roller, so that the resin paste and the glass fiber were soaked and mixed into one body. Then, the air was removed by the rolling roller to fully infiltrate the resin paste and the fiber. It was wound up and cured at 50 °C for 24 h to obtain the SMC material.

[0043] Example 2

[0044] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 O-phthalic neopentyl glycol unsaturated polyester resin 10 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0045] An SMC material was prepared by a method similar to that of Example 1.

[0046] Example 3

[0047] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 p-Phthalic neopentyl glycol unsaturated polyester resin 10 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0048] An SMC material was prepared by a method similar to that of Example 1.

[0049] Example 4

[0050] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 Isophthalic propylene glycol unsaturated polyester resin 10 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0051] An SMC material was prepared by a method similar to that of Example 1.

[0052] Example 5

[0053]

[0054]

[0055] In a high-speed shear mixer (1500 r / min), successively add phenolic vinyl resin, epoxy vinyl resin, isophthaloneopentyl glycol unsaturated polyester resin, PE powder, polytetrafluoroethylene micro-powder, tert-butyl perbenzoate, zinc stearate, ceramic micro-powder, alumina micro-powder, alumina micro-powder according to the weight ratio, mix and stir for 8 min, then add magnesium oxide and continue to stir for 10 min, controlling the system temperature not to exceed 45 °C to form a resin paste;

[0056] Pour the resin paste onto the upper and lower rubber tables of the SMC laminator, start the laminator, unwind the upper and lower base polyethylene films, and the scrapers on the upper and lower rubber tables evenly coat the resin paste on the upper and lower base polyethylene films. When the PET film on the lower rubber table passes through the fiber sedimentation area, glass fibers (25 mm) are evenly sedimented on the resin composition, controlling the mass ratio of fiber to resin paste to be 60:62. The lower film carrying the fibers and the upper film pass through the pressure roller to make the resin paste and the glass fibers soak and mix into one body, and then the air is removed by the rolling roller to make the resin paste and the fibers fully infiltrated, and then it is wound up and cured at 50 °C for 24 h to obtain the SMC material.

[0057] Example 6

[0058] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 Isophthalic neopentyl glycol unsaturated polyester resin 15 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0059] In a high-speed shear mixer (1500 r / min), successively add phenolic vinyl resin, epoxy vinyl resin, isophthaloneopentyl glycol unsaturated polyester resin, PE powder, polytetrafluoroethylene micro-powder, tert-butyl perbenzoate, zinc stearate, ceramic micro-powder, alumina micro-powder, alumina micro-powder according to the weight ratio, mix and stir for 8 min, then add magnesium oxide and continue to stir for 10 min, controlling the system temperature not to exceed 45 °C to form a resin paste;

[0060] Pour the resin paste onto the upper and lower rubber tables of the SMC laminator, start the laminator, unwind the upper and lower base polyethylene films, and the scrapers on the upper and lower rubber tables evenly coat the resin paste on the upper and lower base polyethylene films. When the PET film on the lower rubber table passes through the fiber sedimentation area, glass fibers (25 mm) are evenly sedimented on the resin composition, controlling the mass ratio of fiber to resin paste to be 60:72. The lower film carrying the fibers and the upper film pass through the pressure roller to make the resin paste and the glass fibers soak and mix into one body, and then the air is removed by the rolling roller to make the resin paste and the fibers fully infiltrated, and then it is wound up and cured at 50 °C for 24 h to obtain the SMC material.

[0061] Example 7

[0062] Serial number Raw material Parts by weight 1 Phenolic vinyl resin 10 2 Epoxy vinyl resin 10 3 Isophthalic neopentyl glycol unsaturated polyester resin 20 4 PE powder 3 5 Polytetrafluoroethylene micro powder 5 6 Tert-butyl peroxybenzoate (curing agent) 2 7 Zinc stearate (demolding agent) 2 8 Ceramic micro powder 10 9 Aluminum oxide micro powder 10 10 Magnesium oxide (thickening agent) 5 11 Glass fiber (25mm) 60

[0063] In a high-speed shearing mixer (1500 r / min), phenolic vinyl resin, epoxy vinyl resin, isophthalone neopentyl glycol unsaturated polyester resin, PE powder, polytetrafluoroethylene micro-powder, tert-butyl peroxybenzoate, zinc stearate, ceramic micro-powder, alumina micro-powder, and alumina micro-powder were sequentially added according to the weight ratio, and mixed and stirred for 8 min. Then, magnesium oxide was added and stirring was continued for 10 min while controlling the system temperature not to exceed 45 °C to form a resin paste.

[0064] The resin paste was poured onto the upper and lower rubber tables of an SMC compounding machine. The compounding machine was started, and the upper and lower base polyethylene films were unrolled. The scrapers on the upper and lower rubber tables evenly coated the resin paste on the upper and lower base polyethylene films. When the PET film on the lower rubber table passed through the fiber sedimentation area, glass fibers (25 mm) were evenly sedimented on the resin composition, and the mass ratio of fiber to resin paste was controlled to be 60:77. The lower film carrying the fibers and the upper film passed through a pressure roller, so that the resin paste and the glass fibers were soaked and mixed into one body. Then, air was removed through a rolling roller to fully infiltrate the resin paste and the fibers. It was wound up and cured at 50 °C for 24 h to obtain an SMC material.

[0065] Application Example 1

[0066] The SMC material obtained in the above example was pressed at 140 °C, with a pressure of 1000 T / m 2 , and the time was 30 s / mm. Finally, a molded product of the SMC material was obtained.

[0067] The impact toughness of the molded product was tested according to GB / T1451-2005, and the test results are as follows:

[0068]

[0069] The molded product was baked at 250 °C for 2 h to test its heat resistance, and the test results are as follows:

[0070]

[0071] The above-described embodiments are only relatively preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. An SMC material, the SMC material comprising phenolic vinyl resin, epoxy vinyl resin, unsaturated polyester resin, corrosion-resistant plastic additives, curing agent, mold release agent, ceramic micro-powder, alumina micro-powder, thickening agent and glass fiber; The unsaturated polyester resin is isophthaloneopentyl glycol unsaturated polyester resin; The corrosion-resistant plastic additives are selected from one or two of PE powder and polytetrafluoroethylene micro-powder; The curing agent is selected from one or two of tert-butyl peroxybenzoate or dicumyl peroxide; The mold release agent is selected from one or two of zinc stearate or calcium stearate; The thickening agent is selected from one or several of magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide; The glass fiber is selected from glass fiber of 10 - 30 mm; The SMC material comprises 10 parts by weight of phenolic vinyl resin; The SMC material comprises 10 parts by weight of epoxy vinyl resin; The SMC material comprises 10 parts by weight of isophthaloneopentyl glycol unsaturated polyester resin; The SMC material comprises 6 - 20 parts by weight of corrosion-resistant plastic additives; The SMC material comprises 0.3 - 2 parts by weight of curing agent; The SMC material comprises 1 - 3 parts by weight of mold release agent; The SMC material comprises 10 - 20 parts by weight of ceramic micro-powder; The SMC material comprises 10 - 20 parts by weight of alumina micro-powder; The SMC material comprises 1 - 5 parts by weight of thickening agent; The SMC material comprises 40 - 60 parts by weight of glass fiber.

2. The SMC material according to claim 1, wherein, The curing agent is selected from tert-butyl peroxybenzoate.

3. The SMC material according to any one of claims 1-2, characterized in that, The mold release agent is selected from zinc stearate.

4. The SMC material according to any one of claims 1-2, characterized in that, The thickening agent is selected from magnesium oxide.

5. The SMC material according to any one of claims 1-2, characterized in that, The glass fiber is selected from glass fiber of 25 mm.

6. The SMC material according to any one of claims 1-2, characterized in that, The SMC material comprises 3 - 10 parts by weight of PE powder and 3 - 10 parts by weight of polytetrafluoroethylene micro-powder.

7. The SMC material according to any one of claims 1 - 2, wherein The SMC material comprises 3 parts by weight of PE powder and 5 parts by weight of polytetrafluoroethylene micro-powder; The SMC material comprises 2 parts by weight of the curing agent tert-butyl peroxybenzoate; The SMC material comprises 2 parts by weight of the mold release agent zinc stearate; The SMC material comprises 10 parts by weight of ceramic micro-powder; The SMC material comprises 10 parts by weight of alumina micro-powder; The SMC material comprises 5 parts by weight of the thickening agent magnesium oxide; The SMC material comprises 60 parts by weight of 25 mm glass fiber.

8. A preparation method of the SMC material according to any one of claims 1-7, characterized in that, Comprising the following steps: Mix the phenolic vinyl resin, epoxy vinyl resin, unsaturated polyester resin, corrosion-resistant plastic additives, curing agent, mold release agent, ceramic micro-powder, alumina micro-powder evenly, and then add the thickening agent and mix evenly to obtain a resin paste; Coat the resin paste on the upper and lower two polyethylene films, and the glass fiber is evenly settled on the resin paste. The lower film carrying the fiber and the upper film are roll-pressed, wound, and cured to obtain the SMC material.

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