High-strength p-benzene pultrusion resin as well as preparation method and application thereof

Abstract

The invention discloses high-strength p-benzene pultruded resin as well as a preparation method and application thereof, and belongs to the technical field of unsaturated polyester resin. The p-benzene pultrusion resin is prepared from the following raw materials in parts by weight: 330 to 420 parts of diethylene glycol, 150 to 250 parts of propylene glycol, 40 to 120 parts of ethylene glycol, 390 to 440 parts of maleic anhydride, 350 to 450 parts of terephthalic acid, 50 to 150 parts of phthalic anhydride, 0.3 to 1.0 part of an antioxidant, 0.3 to 0.8 part of a catalyst, 0.1 to 0.5 part of a first polymerization inhibitor, 0.1 to 0.5 part of a second polymerization inhibitor, 0.01 to 0.04 part of a stabilizer, 0.3 to 0.8 part of a catalyst and 600 to 700 parts of styrene. The high-strength p-benzene pultruded resin has the advantages of excellent mechanical properties, good toughness, good corrosion resistance, low price and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of unsaturated polyester resins, and in particular relates to a high-strength paraben pultrusion resin and a preparation method and application thereof. Background Art

[0002] Pultrusion resin is a key component in the pultrusion manufacturing process. It is used to manufacture continuous profiles of fiber reinforced polymer (FRP) materials. The products are widely used in construction and infrastructure, electrical and telecommunications, transportation, industrial and corrosive environments, and renewable energy. Among them, unsaturated polyester resin is a commonly used pultrusion resin. As a matrix, it has a great influence on the mechanical strength, corrosion resistance, and heat resistance of composite materials. At present, my country's pultruded unsaturated polyester resin-based composite materials industry is developing rapidly. Unsaturated polyester resins generally use o-phthalate and isophthalate unsaturated polyester resins. The bending strength of o-phthalate and isophthalate resins is worse than that of p-phthalate resins, which has a great influence on the application of composite materials. However, the corrosion resistance and some mechanical properties of o-phthalate and isophthalate resins are not as good as those of p-phthalate resins. In addition, the prices of o-phthalate and isophthalate continue to rise, and the preparation cost of pultruded unsaturated polyester resins is also increasing. In the actual production of unsaturated polyester resins, multiple acids and multiple alcohols are often used for synthesis reactions. The different molar ratios of acids and alcohols have a great influence on the mechanical properties of the resin.

[0003] Patent CN116512642B discloses a composite high-strength fiberglass pultruded profile, which uses unsaturated polyester resin, epoxy resin, phenolic resin, glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fiber and other materials, and considers the effect of fiber posture on mechanical strength during the preparation process, thereby improving the mechanical strength of the composite fiberglass and reducing the overall weight. However, in this technical solution, the composite use of multiple resins and fibers increases the complexity and cost of the materials, and the proportion and mixing method of multiple materials need to be precisely controlled during the preparation process, which may lead to increased production difficulty and rising costs. In addition, the mixed use of multiple fibers may affect the uniformity and stability of the material, and affect the performance and quality of the final product.

[0004] The above problems indicate that the existing high-strength pultruded resin preparation process still has certain shortcomings in terms of complexity, cost control, material uniformity and stability. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a high-strength phenylene pultrusion resin having good corrosion resistance, good wettability, excellent mechanical properties and low price and a preparation method thereof.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a high-strength phenylene pultrusion resin, wherein the raw materials by weight include: 330-420 parts of diethylene glycol, 40-120 parts of ethylene glycol, 150-250 parts of propylene glycol, 390-440 parts of maleic anhydride, 350-450 parts of terephthalic acid, 50-150 parts of phthalic anhydride, 0.3-1.0 parts of antioxidant, 0.3-0.8 parts of catalyst, 0.1-0.5 parts of first polymerization inhibitor, 0.1-0.5 parts of second polymerization inhibitor, 0.01-0.04 parts of stabilizer and 600-700 parts of styrene.

[0007] The para-phenylene resin used in the present invention shows better corrosion resistance than ortho-phenylene and iso-phenylene resins, can effectively resist various corrosion environments, and extend the service life of the composite material; in terms of mechanical properties, through a specific raw material ratio and synthesis process, the mechanical strength of the resin is significantly improved, and the demand for high-strength pultruded composite materials can be met; its impregnation performance is good, and the formula design of the resin makes it have a low viscosity and good fluidity, which can better impregnate the fiber, ensure the close bonding between the fiber and the resin, and improve the overall performance of the composite material; in terms of cost control, the price of para-phenylene resin is relatively low, and the technical solution reduces unnecessary complex components and steps by optimizing the raw material ratio and the synthesis process, which helps to reduce production costs; at the same time, the technical solution focuses on the optimization of para-phenylene resin, avoids the uniformity and stability problems that may be caused by the mixing of multiple materials, and ensures the performance and quality of the final product; and the resin is suitable for pultrusion manufacturing process, can meet the requirements of continuous production, and ensure the stability and efficiency of the production process.

[0008] Preferably, the raw material weight composition includes: 360-420 parts of diethylene glycol, 60-100 parts of ethylene glycol, 180-230 parts of propylene glycol, 390-410 parts of maleic anhydride, 350-400 parts of terephthalic acid, 70-120 parts of phthalic anhydride, 0.3-0.5 parts of antioxidant, 0.3-0.5 parts of catalyst, 0.1-0.3 parts of first inhibitor, 0.1-0.3 parts of second inhibitor, 0.01-0.02 parts of stabilizer, and 630-680 parts of styrene. Under the preferred raw material weight composition, the high-strength phenylene pultrusion resin has more optimized performance and cost-effectiveness.

[0009] Preferably, the molar ratio of maleic anhydride, terephthalic acid and phthalic anhydride in the raw material weight composition of the high-strength phenylene pultrusion resin is 4:2.1~2.5:0.4~0.9. This molar ratio helps to find the best balance between tensile and flexural strength, so that the resin has good flexibility and impact resistance while maintaining high strength; and the appropriate proportion of terephthalic acid ensures the excellent resistance of the resin to various chemicals, while the appropriate addition of phthalic anhydride helps to further improve the corrosion resistance.

[0010] Preferably, the molar ratio of diethylene glycol, ethylene glycol and propylene glycol in the raw material weight composition of the high-strength paraben pultrusion resin is 4: 1 to 1.5: 2.4 to 3. Under the preferred ratio of the three, diethylene glycol can better increase the flexibility of the resin, while propylene glycol helps to improve the heat resistance of the resin, and ethylene glycol plays a balancing role between the two, so that the resin has high heat resistance while maintaining good flexibility; and this molar ratio helps to enhance the tensile and flexural strength of the resin while maintaining good impact toughness.

[0011] Preferably, in the above-mentioned high-strength p-phenylene pultrusion resin, the first polymerization inhibitor and the second polymerization inhibitor are independently selected from any one or more of hydroquinone, hydroquinone, p-benzoquinone, tert-butylhydroquinone, o-methylhydroquinone and tert-butylcatechol. These polymerization inhibitors can effectively prevent the self-polymerization of the p-phenylene pultrusion resin during production and storage, ensure the stability and processability of the resin, and they show good chemical stability in the resin system.

[0012] Preferably, in the above-mentioned high-strength paraben pultrusion resin, the antioxidant is triphenyl phosphite or 2,5-di-tert-butylhydroquinone. The addition of these two antioxidants helps to improve the thermal stability and oxidation resistance of the resin, prolong the service life, and enhance the processing performance of the resin and the performance of the final product.

[0013] Preferably, in the above-mentioned high-strength phenylene pultrusion resin, the catalyst is a combination of any one or more of monobutyltin oxide, zinc acetate and stannous chloride. The combined use of these catalysts helps to improve the production efficiency of the resin and the performance of the final product.

[0014] Preferably, in the above-mentioned high-strength phenylene pultrusion resin, the stabilizer is a combination of tert-butylhydroquinone and benzoquinone in any proportion. Tert-butylhydroquinone has a strong antioxidant ability, which can effectively prevent the oxidative degradation of the resin during storage and use, and extend the service life of the resin. It can still maintain good stability under high temperature conditions and will not fail due to temperature changes, which helps to maintain the performance of the resin. Benzoquinone can prevent the polymerization reaction of the resin under anaerobic conditions, ensuring the stability of the phenylene pultrusion resin during production and storage. This combination can significantly improve the thermal stability and oxidation resistance of the phenylene pultrusion resin, reduce the performance degradation caused by oxidation and polymerization, thereby improving the overall performance and service life of the final composite material.

[0015] A method for preparing the above-mentioned high-strength phenylene pultrusion resin comprises the following steps: 1) Add diethylene glycol, ethylene glycol, terephthalic acid and catalyst into the reactor. Under the protection of inert gas, raise the temperature of the reactor to 170℃~180℃ and keep the temperature for 40min~60min; 2) Raise the temperature of the reactor to 220℃~223℃ and keep the temperature to react until the acid value is lower than 3mgKOH / g; 3) Cool down to 120℃, add propylene glycol, maleic anhydride, phthalic anhydride, first inhibitor and antioxidant into the reactor 4) Raise the temperature of the reactor to 165℃~175℃ and keep the temperature for 40min~60min; 5) Raise the temperature to 204℃~206℃, keep warm and react until the acid value reaches 24mgKOH / g~30mgKOH / g, and the cone-plate viscosity reaches 450mPa·s~480mPa·s (3#, 150℃); 6) Cool down to 180°C and add the second inhibitor into the reactor; 7) Cool down to 120℃, add stabilizer and styrene, stir evenly, and cool down to 60℃ to obtain high-strength phenylene pultrusion resin.

[0016] By adding diethylene glycol, ethylene glycol, terephthalic acid and a catalyst at the beginning of the reaction and keeping the reaction at 170°C~180°C for 40min~60min, it is helpful to promote the esterification reaction, make the raw materials fully mixed and react, and lay the foundation for the subsequent reaction. Then the temperature is raised to 220°C~223°C, and the reaction is kept until the acid value is less than 3mgKOH / g. This step can ensure the full reaction of the anhydride and the alcohol, and improve the molecular weight and mechanical properties of the resin. After cooling to 120°C, propylene glycol, maleic anhydride, phthalic anhydride, the first inhibitor and antioxidant are added, which helps to control the molecular weight and molecular weight distribution of the resin, and prevent the self-polymerization of the resin at high temperature. Raising the temperature of the reactor to 165°C~175°C and keeping the reaction for 40min~60min helps to further promote the polymerization reaction of the resin and improve the comprehensive performance of the resin. Raise the temperature to 204°C~206°C and keep the reaction warm until the acid value and viscosity reach a specific range, which can ensure that the resin has good processing performance and mechanical properties. Cool down to 180°C and add the second inhibitor, which helps to further stabilize the molecular weight and performance of the resin. Finally, cool down to 120°C, add stabilizer and styrene, stir evenly, and cool down to 60°C to obtain high-strength paraben pultrusion resin. This step helps to improve the stability and storage performance of the resin. The entire preparation method can effectively improve the mechanical strength, corrosion resistance and processing performance of the resin by precisely controlling the reaction temperature, time, order of raw material addition and the use of inhibitors, while reducing production costs and improving production efficiency.

[0017] Preferably, in the method for preparing the high-strength benzene pultrusion resin, in steps 2) and 5), the heating rate is 12°C / h to 18°C / h. The preferred heating rate helps the reaction system to be heated evenly, ensuring that the reaction can proceed fully and avoiding side reactions or uneven reactions caused by local overheating. Secondly, this heating rate can effectively control the molecular weight and molecular weight distribution of the resin, which helps to improve the mechanical properties and heat resistance of the resin.

[0018] An application of the above-mentioned high-strength para-phenylene pultrusion resin, wherein the high-strength para-phenylene pultrusion resin is applied as a pultrusion resin.

[0019] According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned thermosetting trenchless repair unsaturated polyester resin, comprising the following steps: Compared with the prior art, the high-strength paraben pultrusion resin and its preparation method and application of the present invention have the following beneficial effects: 1) The present invention uses a large amount of terephthalic acid in the synthetic raw material of the thermosetting unsaturated polyester resin. Although the concentration of terephthalic acid is the same as that of the ortho-phthalic and iso-phthalic ester bonds, the molecular arrangement of the terephthalic acid is symmetrical, which further increases the molecular distance of the ester bond, reduces the repulsive force and polarity, thereby improving the corrosion resistance of the resin; since the symmetrical structure of terephthalic acid has good crystallinity and poor compatibility with styrene, a large amount of diethylene glycol and propylene glycol are used. The low crystallinity of diethylene glycol and the asymmetric structure of propylene glycol are conducive to improving the compatibility with styrene.

[0020] 2) The preparation method of the present invention controls the synthesis conditions of the unsaturated polyester to ensure the normal reaction and the product quality.

[0021] 3) The present invention saves the preparation cost of the pultrusion resin. By further controlling the molar ratio of the three acids and the three alcohols in the raw materials, the comprehensive mechanical properties of the unsaturated polyester resin can be further improved, the chemical resistance can be improved, and the various properties of the benzene pultrusion resin can be improved. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0023] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0024] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0025] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0026] The invention provides a thermosetting trenchless repair unsaturated polyester resin, whose reaction raw materials include: diethylene glycol, propylene glycol, ethylene glycol, terephthalic acid, maleic anhydride, phthalic anhydride, antioxidant, catalyst, first inhibitor, second inhibitor and styrene.

[0027] In the present invention, the weight portion of the diethylene glycol is 330 to 420 parts. It is understood that the weight portion can be any specific value of 330, 340, 350, 360, 370, 380, 390, 400, 410, 420 parts or any value within the range of 330 to 420 parts. In some embodiments, the weight portion of the diethylene glycol is preferably 360 to 400 parts. The inventors of the present invention have found that after a certain amount of diethylene glycol is introduced into the raw materials, the symmetry and low crystallinity of diethylene glycol are conducive to improving the toughness of the resin.

[0028] In the present invention, the weight portion of the propylene glycol is 150 to 250 parts. It is understood that the weight portion can be any specific value of 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250 parts or any value within the range of 150 to 250 parts. In some embodiments, the weight portion of the propylene glycol is preferably 180 to 230 parts. The inventors of the present invention have found that the weight portion of propylene glycol is beneficial to improving the compatibility of polyester and styrene.

[0029] In the present invention, the weight of the ethylene glycol is 40 to 120 parts. It is understood that the weight of the ethylene glycol can be any specific value of 40, 50, 60, 70, 80, 90, 100, 110, 120 parts or any value within the range of 40 to 120 parts. In some embodiments, the weight of the ethylene glycol is preferably 60 to 100 parts. The inventors of the present invention have found that the weight of the ethylene glycol is beneficial to improving the crystallinity and orderliness of the resin, thereby improving the tensile strength of the resin.

[0030] In the present invention, the weight portion of the maleic anhydride is 390 to 440 parts, and it is understandable that the weight portion can be any specific value in 390, 400, 410, 420, 430, 440 parts or any value in the range of 390 to 440 parts. In certain embodiments, the weight portion of the maleic anhydride is preferably 390 to 410 parts. The inventors of the present invention have found that the weight portion of maleic anhydride is conducive to the process of the synthesis reaction and improves the yield and performance stability of the product.

[0031] In the present invention, the weight of the terephthalic acid is 350-450 parts. It is understandable that the weight of the terephthalic acid can be any specific value of 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450 parts or any value within the range of 350-450 parts. In some embodiments, the weight of the terephthalic acid is preferably 350-400 parts. The inventors of the present invention have found that although a certain amount of terephthalic acid is introduced into the raw material, the concentration of the ester bond is the same as that of the o-phthalic and isophthalic ester bonds, but the molecular arrangement of the isophthalic type is symmetrical, which further increases the molecular distance of the ester bond, reduces the repulsion and polarity, thereby improving the corrosion resistance of the resin. In the present invention, the weight portion of the phthalic anhydride is 50 to 150 parts. It is understood that the weight portion can be any specific value of 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 parts or any value within the range of 50 to 150 parts. In certain embodiments, the weight portion of the phthalic anhydride is preferably 70 to 120 parts. The inventors of the present invention have found that the weight portion of phthalic anhydride can improve the bending strength of the resin due to the small spacing between functional groups and the large polarity.

[0032] In the present invention, the weight portion of the antioxidant is 0.3 to 1.0 parts. It is understood that the weight portion can be any specific value of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 parts or any value within the range of 0.3 to 1.0 parts. In some embodiments, the weight portion of the antioxidant is preferably 0.3 to 0.5 parts. In some embodiments, the antioxidant is triphenyl phosphite or 2,5-di-tert-butylhydroquinone.

[0033] In the present invention, the weight portion of the catalyst is 0.3 to 0.8 parts. It is understood that the weight portion can be any specific value of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or any value within the range of 0.3 to 0.8. In some embodiments, the weight portion of the catalyst is preferably 0.3 to 0.5 parts. In some embodiments, the catalyst is any one or more of monobutyltin oxide, zinc acetate and stannous chloride.

[0034] In the present invention, the weight portion of the first polymerization inhibitor is 0.1 to 0.5 parts. It is understood that the weight portion can be any specific value of 0.1, 0.2, 0.3, 0.4, 0.5 parts or any value within the range of 0.1 to 0.5 parts. In some embodiments, the weight portion of the first polymerization inhibitor is preferably 0.1 to 0.3 parts. In some embodiments, the first polymerization inhibitor is selected from any one or more of hydroquinone, hydroquinone, p-benzoquinone, tert-butylhydroquinone, o-methylhydroquinone and tert-butylcatechol.

[0035] In the present invention, the weight portion of the second polymerization inhibitor is 0.1 to 0.5 parts. It is understood that the weight portion can be any specific value of 0.1, 0.2, 0.3, 0.4, 0.5 parts or any value within the range of 0.1 to 0.5 parts. In some embodiments, the weight portion of the second polymerization inhibitor is preferably 0.1 to 0.3 parts. In some embodiments, the second polymerization inhibitor is selected from any one or more of hydroquinone, hydroquinone, p-benzoquinone, tert-butylhydroquinone, o-methylhydroquinone and tert-butylcatechol.

[0036] In the present invention, the weight portion of the stabilizer is 0.01 to 0.04 parts. It is understood that the weight portion can be any specific value of 0.01, 0.02, 0.03, 0.04 parts or any value within the range of 0.01 to 0.04 parts. In some embodiments, the weight portion of the third inhibitor is preferably 0.01 to 0.02 parts. In some embodiments, the stabilizer is any one or more of tert-butylhydroquinone and benzoquinone. In the present invention, the weight of the styrene is 600-700 parts. It is understood that the weight of the styrene can be any specific value of 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700 parts or any value within the range of 600-700 parts. In some embodiments, the weight of the styrene is preferably 630-670 parts.

[0037] In the present invention, the molar ratio of maleic acid, terephthalic acid and phthalic anhydride in the raw material is 4:2.1-2.5:0.4-0.9. It can be understood that the molar ratio can be any specific molar ratio of 4:2.1, 2.2, 2.3, 2,4 or 2.5:0.4, 0.5, 0.6, 0.7, 0.7, 0.8 or 0.9 or any numerical value in the range of 4:2.1-2.5:0.4-0.9. The ratio of the three acids shown, the content of maleic anhydride is increased, the heat deformation temperature is increased, and the tensile strength is reduced; when the content of terephthalic acid is high, the tensile strength is high and the bending strength is reduced; when the content of terephthalic acid is high, the bending strength is high and the tensile strength is reduced; In the present invention, the molar ratio of diethylene glycol, ethylene glycol and propylene glycol in the raw material is 4:1.1~1.8:2.5~3.4. It can be understood that the molar ratio can be any specific molar ratio of 4:1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7 or 1.8:2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3 or 3.4, or any ratio within the range of 4:1.1~1.8:2.5~3.4. When the content of diethylene glycol in the raw material increases, the toughness increases and the elastic modulus decreases; when the content of ethylene glycol increases, the modulus increases and the compatibility with styrene decreases; when the content of propylene glycol increases, the compatibility with styrene increases and the tensile strength decreases.

[0038] According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned phenylene pultrusion resin, comprising the following steps: 1) Add diethylene glycol, ethylene glycol, terephthalic acid and catalyst into the reactor. Under the protection of inert gas, raise the temperature of the reactor to 170℃~180℃ and keep the temperature for 40min~60min; 2) Raise the temperature of the reactor to 220℃~223℃ and keep the temperature to react until the acid value is lower than 3mgKOH / g; 3) Cool down to 120℃, add propylene glycol, maleic anhydride, phthalic anhydride, first inhibitor and antioxidant into the reactor 4) Raise the temperature of the reactor to 165℃~175℃ and keep the temperature for 40min~60min; 5) Raise the temperature to 204℃~206℃, keep warm and react until the acid value is 24mgKOH / g~30mgKOH / g, and the cone and plate viscosity is 450mPa·s~480mPa·s (3#, 150℃); 6) Cool down to 180°C and add the second inhibitor into the reactor; 7) Cooling to 120° C., adding stabilizer and styrene, stirring evenly, and cooling to 60° C. to obtain the high-strength phenylene pultrusion resin.

[0039] In the present invention, in step 1), diethylene glycol, ethylene glycol, terephthalic acid and a catalyst are added to a reaction kettle, and the temperature of the reaction kettle is raised to 170°C to 180°C under the protection of an inert gas, and the reaction is kept warm for 40min to 60min. In some embodiments, the flow rate of the inert gas is 5m 3 / h~20m 3 / h, it is understandable that its flow rate can be 5m 3 / h、10m 3 / h、15m 3 / h、20m 3Any specific value in / h or 5m 3 / h~20m 3 / h. In some embodiments, the inert gas may be nitrogen. In some embodiments, in step 1), the temperature of the reactor is raised to 170°C to 180°C. It is understood that the temperature may be any specific value of 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C or any value within the range of 170°C to 180°C. In some embodiments, in step 1), the reaction is kept warm for 40min to 60min. It is understood that the insulation time may be any specific value of 40min, 42min, 44min, 46min, 48min, 50min, 52min, 54min, 56min, 58min, 60min or any value within the range of 40min to 60min. In some embodiments, in step 1), the heating rate of the reactor is 12°C / h~18°C / h. It can be understood that the heating rate can be any specific value of 12°C / h, 13°C / h, 14°C / h, 15°C / h, 16°C / h, 17°C / h, 18°C / h or any value within the range of 12°C / h~18°C / h.

[0040] In some embodiments, in step 2), the temperature is raised to 220°C~223°C, and the temperature is kept to react until the acid value is less than 3mgKOH / g. In some embodiments, in step 2), the heating rate is 12°C / h~18°C / h. It can be understood that the heating rate can be any specific value of 12°C / h, 13°C / h, 14°C / h, 15°C / h, 16°C / h, 17°C / h, 18°C / h or any value within the range of 12°C / h~18°C / h. In some embodiments, the temperature is raised to 220°C~223°C. It can be understood that the temperature can be any specific value of 220°C, 221°C, 222°C, 223°C or any value within the range of 220°C~223°C. The reaction acid value of step 2) is controlled below a certain value to ensure that terephthalic acid participates in the reaction as much as possible, so that the synthesized resin has a certain order in structure, thereby improving the tensile strength of the resin.

[0041] In some embodiments, in step 3), the temperature is lowered to 120° C., and propylene glycol, maleic anhydride, phthalic anhydride, a first inhibitor and an antioxidant are added to the reaction kettle.

[0042] In some embodiments, in step 4), the temperature of the reactor is raised to 165°C~175°C, and the reaction is kept warm for 40min~60min. In some embodiments, in step 4), the heating rate is 12°C / h~18°C / h. It can be understood that the heating rate can be any specific value of 12°C / h, 13°C / h, 14°C / h, 15°C / h, 16°C / h, 17°C / h, 18°C / h or any value within the range of 12°C / h~18°C / h. In some embodiments, the temperature is raised to 165°C~175°C. It can be understood that the temperature can be any specific value of 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C or any value within the range of 165°C~175°C. In some embodiments, in step 4), the reaction is kept warm for 40 min to 60 min. It can be understood that the insulation time can be any specific value of 40 min, 42 min, 44 min, 46 min, 48 min, 50 min, 52 min, 54 min, 56 min, 58 min, 60 min or any value within the range of 40 min to 60 min.

[0043] In some embodiments, in step 5), the temperature of the reactor is raised to 204°C to 206°C, and the temperature is kept to react until the acid value is 24mgKOH / g to 30mgKOH / g, and the cone-plate viscosity is 450mPa·s to 500mPa·s. In some embodiments, in step 5), the heating rate is 12°C / h to 18°C / h. It can be understood that the heating rate can be any specific value of 12°C / h, 13°C / h, 14°C / h, 15°C / h, 16°C / h, 17°C / h, 18°C / h, or any value within the range of 12°C / h to 18°C / h. In some embodiments, in step 5), the reaction is carried out by heat preservation until the acid value is 24 mgKOH / g to 30 mgKOH / g. It is understood that the acid value can be any specific value of 24 mgKOH / g, 25 mgKOH / g, 26 mgKOH / g, 27 mgKOH / g, 28 mgKOH / g, 29 mgKOH / g, 30 mgKOH / g, or any value within the range of 24 mgKOH / g to 30 mgKOH / g. In some embodiments, in step 5), the cone-plate viscosity is reacted to 450 mPa·s to 500 mPa·s. It is understood that the cone-plate viscosity can be any specific value of 450 mPa·s, 460 mPa·s, 470 mPa·s, 480 mPa·s, 490 mPa·s, 500 mPa·s, or any value within the range of 450 mPa·s to 500 mPa·s.

[0044] In some embodiments, in step 6), the temperature is lowered to 180° C. and a second polymerization inhibitor is added into the reactor.

[0045] In some embodiments, in step 7), the temperature is lowered to 120° C., a stabilizer and styrene are added, stirred evenly, and the temperature is lowered to 60° C. to obtain the thermosetting unsaturated polyester resin.

[0046] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention, and are not intended to limit the present invention. The chemical additives used in the examples and comparative examples of the present invention are all commercially available, and the specific information is as follows: Diethylene glycol, propylene glycol, ethylene glycol, maleic anhydride, terephthalic acid, phthalic acid, and styrene: analytically pure, all purchased from Aladdin Reagent Co., Ltd.; antioxidant: triphenyl phosphite, purchased from Jiangsu Evergreen New Materials Technology Co., Ltd.; catalyst: zinc acetate, purchased from Tianjin Jinhui Taiya Chemical Reagent Co., Ltd.; first / second inhibitor: hydroquinone, purchased from Weifang Tongrun Chemical Co., Ltd.; stabilizer: tert-butylhydroquinone, purchased from Wuhan Jixin Yibang Biotechnology Co., Ltd.

[0047] Embodiment 1~5 The raw material ratios of Examples 1 to 5 are shown in Table 1 below, where the amounts of each raw material in Table 1 are in parts by weight.

[0048] Table 1 Reaction materials in Examples 1 to 5 .

[0049] The preparation method of embodiments 1 to 5 comprises the following steps: (1) Add diethylene glycol, ethylene glycol, terephthalic acid and catalyst into the reactor in the order of liquid first and solid later. Under nitrogen protection, raise the temperature of the reactor to 175°C at a rate of 18°C / h. Keep the outlet water warm for 60 minutes. The nitrogen flow rate is 5m 3 / h; (2) gradually raise the temperature to 220°C at a rate of 18°C / h and keep the temperature to react until the acid value reaches 2.7 mgKOH / g; (3) Cooling to 120° C., adding propylene glycol, maleic anhydride, phthalic anhydride, a first inhibitor and an antioxidant into the reaction kettle; (4) Gradually increase the temperature to 170°C at a rate of 18°C / h and keep the temperature for 60 minutes; (5) gradually raise the temperature to 204°C at a rate of 18°C / h and keep the temperature to react until the acid value reaches 28 mgKOH / g and the cone-plate viscosity reaches 460 mPa·s; (6) Cooling to 180°C, adding a second polymerization inhibitor into the reactor; (7) Cool down to 120°C, turn off the nitrogen, add stabilizer and styrene, stir evenly, cool down to 60°C, and obtain high-strength phenylene pultrusion resin.

[0050] Comparative Examples 1 to 5 The raw material ratios of Comparative Examples 1 to 5 refer to Table 2 below, where the amounts of each raw material in Table 2 are in parts by weight.

[0051] Table 2 Reaction materials in comparative examples 1 to 5 .

[0052] Performance Testing 2% of the accelerator cobalt isooctanoate was added to the thermosetting unsaturated polyester resin obtained in Examples 1 to 6 and Comparative Examples 1 to 2, and stirred evenly. Then, 2% of the initiator methyl ethyl ketone peroxide was added, and stirred evenly. The mixture was poured into a steel mold with a size of 350 mm × 300 mm × 5 mm, and cured at 23 ± 2 ° C for 24 hours to obtain a thermosetting unsaturated polyester resin casting. The performance test was carried out according to the following method, and the specific results are shown in Table 3.

[0053] (1) Tensile strength: tested in accordance with standard GB / T 2567-2008; (2) Tensile elastic modulus: tested in accordance with standard GB / T 2567-2008; (3) Elongation at break: tested in accordance with standard GB / T 2567-2008; (4) Bending strength: tested in accordance with standard GB / T 2567-2008; (5) Flexural modulus: tested in accordance with standard GB / T 2567-2008; (6) Impact strength: tested in accordance with standard GB / T 2567-2008; (7) Heat deformation temperature: Tested in accordance with standard GB / T 2567-2008; (8) Chemical resistance: The synthetic unsaturated polyester resin is used to make a resin casting, and the casting is tested for chemical medium resistance according to standard GB / T 3857-2017. The casting after being immersed in the chemical medium is tested for bending performance according to standard GB / T 2567-2008.

[0054] Table 3 Performance data of Examples 1 to 5 and Comparative Examples 1 to 5 .

[0055] Table 4 Comparison of flexural strength and flexural modulus retention rate of castings after immersion in different chemical media for 28 days .

[0056] It can be seen from Table 3 and Table 4 that the thermosetting unsaturated polyester resins described in Examples 1 to 5 of the present invention have better comprehensive mechanical properties and better corrosion resistance of the products. In Comparative Example 1, the proportion of propylene glycol in the three alcohols is too high and the proportion of diethylene glycol is too low, resulting in a decrease in the crystallinity and flexibility of the polyester, so that the impact strength and tensile strength are not as good as those in Examples 1 to 5. In Comparative Example 2, the proportion of terephthalic acid in the three acids is too high and the proportion of phthalic anhydride is too low, which reduces the polarity of the polyester, resulting in a bending strength that is not as good as that in Examples 1 to 5. In Comparative Example 3, the proportion of diethylene glycol in the three alcohols is too high and the proportion of ethylene glycol is too low, which reduces the crystallinity of the polyester and improves the flexibility, resulting in a modulus that is not as good as that in Examples 1 to 5. In Comparative Example 4, the proportion of ethylene glycol in the three alcohols is too high and the proportion of propylene glycol is too low, which increases the crystallinity of the polyester and deteriorates the compatibility with styrene, resulting in resin delamination and mechanical properties that are not as good as those in Examples 1 to 5. In comparative example 5, the proportion of phthalic anhydride in the three acids is too high, and the proportion of terephthalic acid is too low, which leads to a decrease in the symmetry of the polyester, further reducing the molecular distance of the ester bond, increasing the repulsion and polarity, so that the corrosion resistance of the resin is not as good as that of Examples 1 to 5, and the phthalic acid content is increased, and the polyester synthesis price will also increase. It shows that the use of a suitable molar ratio of the three alcohols and the three acids is beneficial to improving the comprehensive mechanical properties of the casting body and improving the corrosion resistance of the product.

[0057] It can be seen that the present invention controls the molar ratio of three alcohols and three acids in the synthetic raw materials of the thermosetting unsaturated polyester resin so that the alcohol and the acid have a better synergistic effect, so that the thermosetting unsaturated polyester resin is easy to manufacture, low in cost, excellent in comprehensive mechanical properties, and resistant to corrosion by acids, alkalis and various solvents.

[0058] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A high-strength phenylene pultrusion resin, characterized in that: The raw materials include: 330-420 parts by weight of diethylene glycol, 40-120 parts by weight of ethylene glycol, 150-250 parts by weight of propylene glycol, 390-440 parts by weight of maleic anhydride, 350-450 parts by weight of terephthalic acid, 50-150 parts by weight of phthalic anhydride, 0.3-1.0 parts by weight of an antioxidant, 0.3-0.8 parts by weight of a catalyst, 0.1-0.5 parts by weight of a first polymerization inhibitor, 0.1-0.5 parts by weight of a second polymerization inhibitor, 0.01-0.04 parts by weight of a stabilizer, and 600-700 parts by weight of styrene.

2. A high-strength phenylene pultrusion resin according to claim 1, characterized in that: The raw materials include, by weight: 360-420 parts of diethylene glycol, 60-100 parts of ethylene glycol, 180-230 parts of propylene glycol, 390-410 parts of maleic anhydride, 350-400 parts of terephthalic acid, 70-120 parts of phthalic anhydride, 0.3-0.5 parts of antioxidant, 0.3-0.5 parts of catalyst, 0.1-0.3 parts of first polymerization inhibitor, 0.1-0.3 parts of second polymerization inhibitor, 0.01-0.02 parts of stabilizer and 630-680 parts of styrene.

3. A high-strength phenylene pultrusion resin according to claim 1, characterized in that: The molar ratio of maleic anhydride, terephthalic acid and phthalic anhydride in the raw material composition is 4:2.1-2.5:0.4-0.

9.

4. The high-strength phenylene pultrusion resin according to claim 1, characterized in that: The molar ratio of diethylene glycol, ethylene glycol and propylene glycol in the raw material composition is 4:1-1.5:2.4-3.

5. A high-strength phenylene pultrusion resin according to claim 1 or 2, characterized in that: The first polymerization inhibitor and the second polymerization inhibitor are each independently selected from any one or more of hydroquinone, hydroquinone, p-benzoquinone, tert-butylhydroquinone, o-methylhydroquinone and tert-butylcatechol.

6. A high-strength phenylene pultrusion resin according to claim 1 or 2, characterized in that: The antioxidant is triphenyl phosphite or 2,5-di-tert-butylhydroquinone.

7. A high-strength phenylene pultrusion resin according to claim 1 or 2, characterized in that: The catalyst is any one or more combinations of monobutyltin oxide, zinc acetate and stannous chloride; the stabilizer is any combination of tert-butylhydroquinone and benzoquinone.

8. A method for preparing the high-strength paraben pultrusion resin according to any one of claims 1 to 7, characterized in that: The steps include: 1) Add diethylene glycol, ethylene glycol, terephthalic acid and catalyst into the reactor. Under the protection of inert gas, raise the temperature of the reactor to 170℃~180℃ and keep the temperature for 40min~60min; 2) Raise the temperature of the reactor to 220℃~223℃ and keep the temperature to react until the acid value is lower than 3mgKOH / g; 3) Cool down to 120℃, add propylene glycol, maleic anhydride, phthalic anhydride, first inhibitor and antioxidant into the reactor 4) Raise the temperature of the reactor to 165℃~175℃ and keep the temperature for 40min~60min; 5) Raise the temperature to 204°C~206°C, keep the temperature and react until the acid value reaches 24mgKOH / g~30mgKOH / g, and the cone-plate viscosity reaches 450mPa·s~480mPa·s; 6) Cool down to 180°C and add the second inhibitor into the reactor; 7) Cool down to 120℃, add stabilizer and styrene, stir evenly, and cool down to 60℃ to obtain high-strength phenylene pultrusion resin.

9. The method for preparing a high-strength paraben pultrusion resin according to claim 8, characterized in that: In steps 2) and 5), the heating rate is 12°C / h~18°C / h.

10. An application of the high-strength paraben pultrusion resin according to any one of claims 1 to 6, characterized in that: The high-strength paraben pultrusion resin is used as pultrusion resin.