CN109180492B

CN109180492B - Rosin benzocyclobutene monomer capable of free radical polymerization, preparation method and application thereof

Info

Publication number: CN109180492B
Application number: CN201811186912.7A
Authority: CN
Inventors: 王丹; 付飞; 沈明贵; 商士斌; 宋湛谦; 宋杰
Original assignee: Institute of Chemical Industry of Forest Products of CAF
Current assignee: Institute of Chemical Industry of Forest Products of CAF
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2021-02-19
Anticipated expiration: 2038-10-12
Also published as: CN109180492A

Abstract

The invention discloses a free-radically polymerizable rosin benzocyclobutene monomer, a preparation method thereof and a prepared benzocyclobutene resin, a free-radically polymerizable rosin benzocyclobutene monomer, and its molecule The structural formula is:

The preparation method of the above-mentioned free-radically polymerizable rosin benzocyclobutene monomer is as follows, taking dehydroabietic acid as a raw material, and successively passing through bromination, Suzuki coupling and esterification to obtain a free-radically polymerizable rosin benzocyclobutene monomer. Cyclobutene monomer. The free-radically polymerizable rosin benzocyclobutene monomer of the present invention can carry out free-radical polymerization and post-ring-opening polymerization, and synthesize functional monomers through various reaction pathways to prepare polymer materials. The thermal stability, water resistance and dielectric properties of the resin prepared from the rosin benzocyclobutene monomer are improved; the reprocessing and utilization of the rosin is strengthened, the use value of the rosin is improved, and the use of petrochemical resources is reduced.

Description

Rosin benzocyclobutene monomer capable of free radical polymerization, preparation method and application thereof

Technical Field

The invention relates to a rosin benzocyclobutene monomer capable of free radical polymerization, a preparation method and application thereof, belonging to the field of organic synthesis.

Background

In recent years, rosin-modified molecular materials have been widely used in the fields of surfactants, ink coatings, food industry, paper-making aids, pharmaceuticals and pesticides, etc., and rosin-modified polymer materials are used as substitutes for conventional petrochemical materials, so that the environmental damage can be reduced, and the exhaustion of petroleum resources can be reduced.

Benzocyclobutene (BCB) resin is a novel active resin, can form thermoplastic resin and thermosetting resin, and has excellent properties of thermal stability, molding processability, low dielectric constant, low thermal expansion coefficient and the like. Based on these excellent properties, BCB resins have been widely used in the fields of electronics, microelectronics industry, and the like. With the development of very large scale integrated circuits, multi-chip modules and the like, the requirements on the dielectric material of the intermediate layer are higher and higher, and the material not only needs to have excellent dielectric properties, but also needs to have excellent thermal stability, water resistance and the like. A single BCB resin material cannot meet the requirements of these applications in terms of properties, so that it is required to improve the properties of the BCB resin by introducing other groups.

Disclosure of Invention

In order to solve the above-mentioned defects in the prior art, the present invention provides a radically polymerizable rosin benzocyclobutene monomer, a preparation method thereof, and an application thereof, and a polymer prepared from the radically polymerizable rosin benzocyclobutene monomer has significantly improved dielectric properties, thermal stability, hydrophobicity, and the like.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a rosin benzocyclobutene monomer capable of free radical polymerization has a molecular structural formula as follows:

the monomer can be subjected to free radical polymerization and ring-opening post-polymerization, a functional monomer is synthesized through multiple reaction ways to prepare a high polymer material, and the thermal stability, the water resistance and the dielectric property of the resin prepared by utilizing the free radical polymerizable rosin benzocyclobutene monomer (12-position benzocyclobutene dehydroabietic acid propenyl ester) are remarkably improved.

The monomer can be subjected to free radical polymerization at low temperature and can be further subjected to post-polymerization at high temperature to form crosslinked resin.

The preparation method of the rosin benzocyclobutene monomer capable of free radical polymerization comprises the steps of taking dehydroabietic acid as a raw material, and sequentially carrying out bromination, Suzuki coupling and esterification reaction to prepare the rosin benzocyclobutene monomer capable of free radical polymerization.

In order to increase the yield, the preferred synthetic route is as follows:

NBS in the above formula is N-bromosuccinimide.

The preparation method of the rosin benzocyclobutene monomer capable of free radical polymerization comprises the following steps:

1) reacting dehydroabietic acid with N-bromosuccinimide at room temperature for 12-24h to generate 12-bit bromo-dehydroabietic acid shown in formula (I);

2) under the protection of inert atmosphere, under the action of alkali and palladium catalyst, reacting 12-bit bromo dehydroabietic acid with 4-boronate benzocyclobutene at 50-80 ℃ for 8-12h to generate 12-bit benzocyclobutene dehydroabietic acid shown in formula (II);

3) reacting 12-position benzocyclobutene dehydroabietic acid with bromopropene at 60-80 ℃ for 8-12h to generate the rosin benzocyclobutene monomer capable of free radical polymerization shown in the formula (III).

In order to further improve the reaction efficiency and the product yield, the preparation method of the rosin benzocyclobutene monomer capable of free radical polymerization comprises the following steps

1) Dissolving dehydroabietic acid and N-bromosuccinimide in a molar ratio of 1 (1-2) in a first solvent, and reacting at room temperature for 12-24h to generate 12-bit bromo-dehydroabietic acid;

2) under the protection of inert atmosphere, dissolving 12-bit bromo dehydroabietic acid and 4-boronate benzocyclobutene in a molar ratio of 1 (1-2) in a second solvent, adding an alkali and a palladium catalyst in a molar ratio of 1 (0.001-0.01), and continuously reacting at 50-80 ℃ for 8-12h under the protection of inert atmosphere to generate 12-bit benzocyclobutene dehydroabietic acid, wherein the molar ratio of the alkali to the 12-bit bromo dehydroabietic acid is (1-2): 1;

3) dissolving 12-bit benzocyclobutene dehydroabietic acid in a third solvent, and adding alkali to obtain a first solution, wherein the molar ratio of the alkali to the 12-bit benzocyclobutene dehydroabietic acid is 1: (1-2); and then, dissolving bromopropylene in a fourth solvent to obtain a second solution, wherein the molar ratio of the bromopropylene to the 12-position benzocyclobutene dehydroabietic acid is 1: (1-2), then dropping the second solution into the first solution at 50 ℃, and reacting for 8-12h at 60-80 ℃ after dropping to generate the rosin benzocyclobutene monomer capable of free radical polymerization.

In order to further improve the reaction efficiency, the first solvent in the step 1) is acetonitrile; the second solvent in the step 2) is at least one of ethanol, benzene, toluene, dioxane, dimethyl ether, dimethylformamide, dimethyl sulfoxide or water; the third solvent and the fourth solvent in the step 3) are at least one of acetone, dichloromethane, petroleum ether, N-dimethylformamide or tetrahydrofuran.

The alkali in the step 2) and the step 3) is inorganic alkali or organic alkali.

In order to further improve the reaction efficiency, it is preferable that the inorganic base is at least one of sodium carbonate, potassium phosphate, or cesium carbonate; the organic base is triethylamine or pyridine.

In order to further improve the reaction efficiency, preferably, the palladium catalyst in step 2) is: 1,1' -bis-diphenylphosphino ferrocene palladium dichloride, tetrakis (triphenylphosphine) palladium, bis (triphenylphosphine) palladium dichloride or palladium acetate.

The rosin benzocyclobutene monomer capable of free radical polymerization can be used for preparing polymer materials, and the prepared polymer has remarkable improvement on dielectric property, thermal stability, hydrophobicity and the like.

As a preferable embodiment, the method for preparing the polymer from the radically polymerizable rosin benzocyclobutene monomer comprises the following steps:

the method comprises the steps of adding a free radical polymerizable rosin benzocyclobutene monomer into a solvent, adding an initiator, and carrying out heating reaction at 70-90 ℃ for 5-10h to carry out free radical polymerization to obtain a prepolymer, wherein the mass consumption of the initiator is 2-4 wt% of the free radical polymerizable rosin benzocyclobutene monomer;

heating and curing the prepolymer in an electric heating constant-temperature drying oven under the atmosphere of inert gas to obtain the polymer, wherein the heating and curing are sequentially performed for 1 plus or minus 0.1h at 130 plus or minus 10 ℃,1 plus or minus 0.1h at 180 plus or minus 10 ℃,1 plus or minus 0.1h at 220 plus or minus 10 ℃, 4 plus or minus 0.2h at 240 plus or minus 10 ℃, 4 plus or minus 0.2h at 260 plus or minus 10 ℃ and 2 plus or minus 0.2h at 280 plus or minus 10 ℃.

The thermal stability, the water resistance and the dielectric property of the benzocyclobutene resin obtained by polymerizing the rosin benzocyclobutene monomer capable of free radical polymerization are improved.

The prior art is referred to in the art for techniques not mentioned in the present invention.

The rosin benzocyclobutene monomer capable of free radical polymerization can be subjected to free radical polymerization and ring-opening polymerization, a functional monomer is synthesized through multiple reaction ways to prepare a high polymer material, and the thermal stability, the water resistance and the dielectric property of the resin prepared by utilizing the rosin benzocyclobutene monomer capable of free radical polymerization are improved; the reprocessing and utilization of the rosin are enhanced, the use value of the rosin is improved, and the use of petrochemical resources is reduced.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of bromodehydroabietic acid at the 12-position obtained in example 1;

FIG. 2 is a mass spectrum of the brominated dehydroabietic acid at the 12-position obtained in example 1;

FIG. 3 is a nuclear magnetic hydrogen spectrum of 12-position benzocyclobutene dehydroabietic acid obtained in example 1;

FIG. 4 is a mass spectrum of 12-position benzocyclobutene dehydroabietic acid obtained in example 1;

FIG. 5 is a nuclear magnetic hydrogen spectrum of a radical polymerizable rosin benzocyclobutene monomer obtained in example 1;

FIG. 6 is a mass spectrum of a radical polymerizable rosin benzocyclobutene monomer obtained in example 1;

FIG. 7 is a graph of differential scanning calorimetry of the free radical polymerizable rosin benzocyclobutene monomer obtained in example 1;

FIG. 8 is a graph of a differential scanning calorimeter of benzocyclobutene resin obtained in example 3;

FIG. 9 is a graph showing thermogravimetric analysis of benzocyclobutene resin obtained in example 3;

fig. 10 is a schematic view showing a contact angle of benzocyclobutene resin obtained in example 3;

FIG. 11 is a schematic diagram showing the dielectric constant of benzocyclobutene resin obtained in example 3;

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.

Example 1

The monomers prepared in this example were: the 12-position benzocyclobutene dehydroabietic acid allyl alcohol ester has the following structure:

the preparation process comprises the following steps:

1) adding 5.00g of starting material dehydroabietic acid, 5.54g of NBS and 337mL of anhydrous acetonitrile into a round-bottom flask, reacting at 25 ℃ in the dark for 24H, filtering, dissolving solid in ethyl acetate, adding H₂O extraction, washing of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and washing with H₂O washes the organic phase (50 mL. times.2); then using anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a white solid: the purity of the 12-bit bromo dehydroabietic acid is more than 95%, the yield is more than 90%, and the product structure representation of the step is as follows:¹h NMR (400MHz, DMSO). delta.12.20 (s,1H),7.36(s,1H),7.00(s, 1H); in the examples, 50 mL. times.2 indicates washing 2 times, and the amount of washing solution used per time was 50 mL;

2) 0.419g of the first-step reaction product, 0.185g of 4-boratobenzocyclobutene, and 0.425g of tripotassium phosphate were dissolved in 6mL of a mixture of water and ethanol (water and ethanol in a volume ratio of 1:1) and charged into a three-necked flask under N₂Adding 0.01g of palladium tetratriphenylphosphine under protection; in N₂At ambient temperature of 60 ℃, byCooling to room temperature for 10H, filtering with diatomaceous earth, washing with ethyl acetate, and adding H₂O extraction, washing of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and washing with H₂O washes the organic phase (50 mL. times.2); then anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a white solid: 12-benzocyclobutene dehydroabietic acid, the purity is more than 95%, the yield is more than 90%, and the product structure representation of the step is as follows:¹H NMR(500MHz,DMSO)δ12.16(s,1H),7.10(d,J＝7.5Hz,1H),7.02(dd,J＝7.5,0.9Hz,1H),7.00(s,1H),6.93(s,1H),6.91(s,1H)；

3) adding 0.68g of the second-step reaction product into a 100mL round-bottom flask, then adding 10mL of acetone, heating to 50 ℃, dissolving the solid, and then adding 0.216g of potassium carbonate; 0.377g of bromopropylene was dissolved in 5mL of acetone; then dropwise adding the mixture into a round-bottom flask by using a constant-pressure funnel at 50 ℃, reacting at 70 ℃ for 12 hours after dropwise adding, cooling to room temperature after the reaction is finished, performing suction filtration, washing by using ethyl acetate, and adding H₂O, extraction of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and addition of H₂O washes the organic phase (50 mL. times.2); then anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a colourless oil: the rosin benzocyclobutene monomer capable of free radical polymerization has the purity of more than 95 percent and the yield of more than 90 percent, and the product structure representation of the step is as follows:¹H NMR(500MHz,DMSO)δ7.11(d,J＝6.3Hz,1H),7.02(s,1H),7.01(s,1H),6.93(s,1H),6.91(s,1H),5.92(s,1H),5.30(d,J＝16.7Hz,1H),5.22(d,J＝10.3Hz,1H),4.64–4.51(m,3H),4.56(d,J＝17.8Hz,2H)。

4) differential scanning calorimetry is used for representing that the monomer III can carry out free radical polymerization and high-temperature thermal ring-opening polymerization; 5mg of monomer III are placed in an aluminum dish, N₂As a protective gas, the reaction is carried out in a differential scanning calorimeter, the temperature is increased from 30 ℃ to 180 ℃ at the temperature increasing rate of 10k/min, and the result is shown as a line (r) in FIG. 7; 5mg of monomer III are placed in an aluminum dish and 2% by weight of Azobisisobutyronitrile (AIBN), N are added₂As a shielding gas, the reaction is carried out in a differential scanning calorimeter, the temperature is increased from 30 ℃ to 180 ℃ at the temperature increasing rate of 10k/min, and the result is shown as a line II in figure 7; mixing 5mgMonomer III was placed in an aluminum dish and 2% wt AIBN, N added₂As a shielding gas, the reaction was carried out in a differential scanning calorimeter at a temperature rising rate of 10k/min from 30 ℃ to 300 ℃ and the result was shown by line c in FIG. 7.

Example 2

the preparation process comprises the following steps:

1) adding 5.00g of starting raw material dehydroabietic acid, 5.54g of NBS and 300mL of anhydrous acetonitrile into a round-bottom flask, reacting at 25 ℃ in the dark for 24 hours, filtering, dissolving solid in ethyl acetate, and adding H₂O extraction, washing of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and washing with H₂O washes the organic phase (50 mL. times.2); then using anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a white solid: the purity of the 12-bit bromo dehydroabietic acid is more than 95%, the yield is more than 90%, and the product structure representation of the step is as follows:¹h NMR (400MHz, DMSO). delta.12.20 (s,1H),7.36(s,1H),7.00(s, 1H); in the examples, 50 mL. times.2 indicates washing 2 times, and the amount of washing solution used per time was 50 mL;

2) 0.419g of the first-step reaction product, 0.185g of 4-boratobenzocyclobutene, was dissolved in 10mL of dioxane and charged into a three-necked flask, and 0245g of sodium carbonate was added thereto, and the reaction solution was stirred in the presence of N₂Adding 0.01g of palladium tetratriphenylphosphine under protection; in N₂Reacting at 60 deg.C for 10H, cooling to room temperature, filtering with diatomaceous earth, washing with ethyl acetate, and adding H₂O extraction, washing of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and washing with H₂O washes the organic phase (50 mL. times.2); then anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a white solid: 12-benzocyclobutene dehydroabietic acid, the purity is more than 95%, the yield is more than 90%, and the product structure representation of the step is as follows:¹H NMR(500MHz,DMSO)δ12.16(s,1H),7.10(d,J＝7.5Hz,1H),7.02(dd,J＝7.5,0.9Hz,1H),7.00(s,1H),6.93(s,1H),6.91(s,1H)；

3) adding 0.68g of the second-step reaction product into a 100mL round-bottom flask, then adding 10mL of acetone, heating to 50 ℃, dissolving the solid, and then adding 0.216g of sodium carbonate; 0.377g of bromopropylene was dissolved in 5mL of acetone; then dropwise adding the mixture into a round-bottom flask by using a constant-pressure funnel at 50 ℃, reacting at 70 ℃ for 12 hours after dropwise adding, cooling to room temperature after the reaction is finished, performing suction filtration, washing by using ethyl acetate, and adding H₂O, extraction of the aqueous phase with ethyl acetate (50 mL. times.2), combining the organic phases and addition of H₂O washes the organic phase (50 mL. times.2); then anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a colourless oil: the rosin benzocyclobutene monomer capable of free radical polymerization has the purity of more than 95 percent and the yield of more than 90 percent, and the product structure representation of the step is as follows:¹H NMR(500MHz,DMSO)δ7.11(d,J＝6.3Hz,1H),7.02(s,1H),7.01(s,1H),6.93(s,1H),6.91(s,1H),5.92(s,1H),5.30(d,J＝16.7Hz,1H),5.22(d,J＝10.3Hz,1H),4.64–4.51(m,3H),4.56(d,J＝17.8Hz,2H)。

example 3

Preparation of monomers

0.419g of 12-bromo dehydroabietic acid (product obtained in step 1 of example 1) and 0.185g of 4-boratobenzocyclobutene were dissolved in 10mL of dioxane, and charged into a three-necked flask followed by 0.255g of potassium carbonate in the presence of N₂Adding 0.005g of palladium tetratriphenylphosphine under protection; in N₂Reacting at 75 ℃ for 8H, cooling to room temperature, filtering with diatomite, washing with ethyl acetate, and adding H₂O extraction; the aqueous phase was washed with ethyl acetate (50 mL. times.2), the organic phases were combined and washed with H₂O washes the organic phase (50 mL. times.2); then anhydrous Na₂SO₄The organic phase was dried, filtered and rotary evaporated to give a white solid: 12-bit benzocyclobutene dehydroabietic acid, the product structure representation of this step:¹H NMR(500MHz,DMSO)δ12.16(s,1H),7.10(d,J＝7.5Hz,1H),7.02(dd,J＝7.5,0.9Hz,1H),7.00(s,1H),6.93(s,1H),6.91(s,1H)。

example 4

The scheme for preparing the polymer by free radical polymerization of rosin benzocyclobutene monomer is as follows:

first example 1.0g of radical polymerizable rosin benzocyclobutene monomer obtained in example 1 was dissolved in 5mL of toluene,

adding azodiisobutyronitrile with the mass amount of 3 percent by weight of the free radical polymerization rosin benzocyclobutene monomer to react for 7 hours at the temperature of 75-85 ℃ to obtain a prepolymer;

the method comprises the following steps of heating and curing the prepolymer in an electric heating constant-temperature drying box under the atmosphere of inert gas, wherein the heating and curing procedures are as follows: 130 ℃/1 h; 180 ℃/1 h; 220 ℃/1 h; 240 ℃/4 h; 260 ℃/4 h; and (4) obtaining benzocyclobutene resin at the temperature of 280 ℃/2 h.

As can be seen from FIGS. 8 to 11, the prepared resin was excellent in thermal stability, water resistance and dielectric properties.

Claims

1. a free-radical polymerizable rosin benzocyclobutene monomer is characterized in that: its molecular structural formula is:

2. the preparation method of the free-radical polymerizable rosin benzocyclobutene monomer of claim 1, is characterized in that: take dehydroabietic acid as raw material, pass through bromination, Suzuki coupling and esterification successively, The free radical polymerizable rosin benzocyclobutene monomer is obtained, wherein the structure of dehydroabietic acid is

3. method as claimed in claim 2 is characterized in that: synthetic route is as follows:

4. method as claimed in claim 3 is characterized in that: comprise the following steps:

1) Dehydroabietic acid and N-bromosuccinimide are reacted at room temperature for 12-24h to generate 12-brominated dehydroabietic acid;

2) Under the protection of an inert atmosphere, under the action of alkali and palladium catalyst, the 12-position brominated dehydroabietic acid and 4-boronic acid-based benzocyclobutene are reacted at 50-80 ° C for 8-12 h to generate the 12-position Benzocyclobutene dehydroabietic acid;

3) The 12-position benzocyclobutene dehydroabietic acid and bromopropene are reacted at 60-80° C. for 8-12 hours to generate a free-radical polymerizable rosin benzocyclobutene monomer.

5. method as claimed in claim 4 is characterized in that: comprise the following steps

1) Dehydroabietic acid and N-bromosuccinimide with a molar ratio of 1:(1-2) are dissolved in the first solvent, and react at room temperature for 12-24h to generate 12-position brominated dehydroabietic acid ;

2) under the protection of inert atmosphere, the 12-position brominated dehydroabietic acid and 4-boronic acid-based benzocyclobutene whose molar ratio is 1:(1-2) are dissolved in the second solvent, and the molar ratio is 1 : (0.001-0.01) alkali and palladium catalyst, continue to react under the protection of inert atmosphere, 50-80 DEG C for 8-12h, generate 12-position benzocyclobutene dehydroabietic acid, wherein, alkali and 12-position bromine dehydroabietic acid The molar ratio of hydroabietic acid is (1-2): 1;

3) 12 benzocyclobutene dehydroabietic acids are dissolved in the third solvent and alkali is added to obtain the first solution, wherein the mol ratio of alkali and 12 benzocyclobutene dehydroabietic acids is 1:( 1-2); then dissolving propene bromide in the fourth solvent to obtain a second solution, wherein the molar ratio of propene bromide to the 12-position benzocyclobutene dehydroabietic acid is 1:(1-2), and then in The second solution is dropped into the first solution at 50°C, and after the dropwise addition is completed, the reaction is carried out at 60-80°C for 8-12 hours to generate a free-radically polymerizable rosin benzocyclobutene monomer.

6. The method of claim 5, wherein the first solvent in step 1) is acetonitrile; the second solvent in step 2) is ethanol, benzene, toluene, dioxane, dimethyl ether, At least one of dimethylformamide, dimethyl sulfoxide or water; the third solvent and the fourth solvent in step 3) are acetone, dichloromethane, petroleum ether, N,N-dimethylformamide or at least one of tetrahydrofuran; the bases in step 2) and step 3) are inorganic bases or organic bases.

7. The method of claim 6, wherein the inorganic base is at least one of sodium carbonate, potassium carbonate, potassium phosphate or cesium carbonate; the organic base is triethylamine or pyridine.

8. the method as described in any one of claim 4-7 is characterized in that: the palladium catalyst in step 2) is: 1,1 '-bis-diphenylphosphinoferrocene palladium dichloride, tetrakis (tri at least one of phenylphosphine) palladium, bis(triphenylphosphine) palladium dichloride or palladium acetate.

9. The use of the free-radically polymerizable rosin benzocyclobutene monomer as claimed in claim 1 in the preparation of polymer materials.

10. application as claimed in claim 9 is characterized in that: the method for preparing polymer with radical polymerizable rosin benzocyclobutene monomer is:

(1) Add the free-radically polymerizable rosin benzocyclobutene monomer to the solvent, add the initiator, and conduct free-radical polymerization at 70-90°C for 5-10h heating reaction to obtain a prepolymer. The mass dosage is 2%wt-4%wt of the free-radically polymerizable rosin benzocyclobutene monomer;

(2) Under an inert gas atmosphere, the prepolymer is heated and cured in an electric heating constant temperature drying oven, and the heating and curing are sequentially cured at 130 ± 10 ° C for 1 ± 0.1 h, at 180 ± 10 ° C for 1 ± 0.1 h, and at 180 ± 10 °C. Curing at 220±10℃ for 1±0.1h, curing at 240±10℃ for 4±0.2h, curing at 260±10℃ for 4±0.2h, curing at 280±10℃ for 2±0.2h.