Unsaturated resin (1) Overview

Unsaturated resin (1) Overview (2) Development 1 Source: China Unsaturated Resin Network----------------------------------------------------------------------------- Unsaturated polyester resins (unsaturatedpolyesterresins) refer to polyester polymers with unsaturated bonds (such as double bonds) in the molecular chain. Unsaturated dibasic acid (or anhydride), saturated dibasic acid (or anhydride) and glycol (or polyol) undergo a polycondensation reaction under certain conditions to form an unsaturated polyester. The unsaturated polyester is dissolved in a certain amount of cross-linking monomer (such as styrene) to form a liquid resin, which is an unsaturated polyester resin. When unsaturated polyester resin is added to the initiating system, it can react to form an insoluble and infusible polymer material with a three-dimensional network structure, so it is a typical thermosetting resin. Unsaturated polyester resin has its unique advantages compared with many other thermosetting resins. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that unsaturated polyester resin has good processing characteristics and can be solidified and molded at room temperature (not less than 15-20°C) and normal pressure without releasing any by-products. Moreover, the viscosity of the resin is relatively suitable, and a variety of processing and molding methods can be used, such as hand lay-up molding, injection molding, pultrusion molding, injection molding, winding molding, etc. Unsaturated polyester resin is known in the industry as contact molding or low pressure molding thermosetting resin. 1. Overview 2. Overview of domestic and foreign development (1) Overview of foreign development The development history of unsaturated polyester resin can be roughly divided into three stages. According to China Unsaturated Resin Network ( www.upr-e.cn ) expert introduction, specifically it can be divided into: ①The first stage, from the mid-19th century to the 1930s, was the early stage of unsaturated polyester resin. As early as 1847, Swedish scientist Bertilius reacted tartaric acid and glycerol to obtain polyglyceryl tartrate, which is a solid block of unsaturated polyester resin. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that between 1894 and 1901, unsaturated polyester synthesized by the reaction of ethylene glycol and maleic acid, and polyglyceryl phthalate obtained by the reaction of phthalic anhydride and glycerol appeared successively. This type of polyester products are mainly used in coatings and are still used in related fields today. ②Phase 2, from the 1930s to the end of World War II. As a new type of material, unsaturated polyester resin has been used in war, especially in the field of military aviation. In 1941, propylene-based casting resin made from unsaturated alcohols, such as propylene alcohol, appeared in the United States as a substitute for glass. In 1942, a fiberglass cloth-reinforced polyester resin aircraft radome was developed. This kind of radome has the unique advantages of being lightweight, high-strength, good in microwave permeability, and easy to manufacture. Polyester was commercialized in the United States in 1946, using raw materials such as ethylene glycol, maleic anhydride, styrene, and methacrylic acid. Around the same time, another type of polyester resin was manufactured in the UK, the reaction product of methacrylic acid, phthalic anhydride, and ethylene glycol for use in fiberglass-reinforced molding compounds. In 1944, room temperature curing systems for polyester were developed, such as benzoyl peroxide. * * Amine systems, and subsequently many cold-curing catalyst systems, were developed, which greatly facilitated the molding of polyester and its fiberglass reinforced plastics. ③Stage 3, after World War II to the present. Unsaturated polyester resin has been rapidly promoted and turned to civilian use. This is the rapid development stage of unsaturated polyester resin, and its development exceeds that of other plastic industries. In 1957, castings of unsaturated polyester were used to produce "pearl" buttons. After 1959, unsaturated polyester resin was used to manufacture artificial marble, artificial agate, and floor and pavement covering materials. After 1957, bulk molding compounds and sheet molding compounds were developed, which significantly improved the molding and processing methods of unsaturated polyester resin and enabled the high-speed, high-quality, low-cost, and mass production of polyester products. At present, foreign UPR production and consumption areas are mainly concentrated in the United States, Japan and Western Europe. According to China Unsaturated Resin Network ( www.upr-e.cn ) According to experts, the main manufacturers include 13 companies such as Alpha and Reichhold in the United States, 13 companies including Mitsui Tokui in Japan, and more than 30 manufacturers in Western Europe. According to statistics, the global UPR production in 2000 was about 2 million tons, of which the U.S. UPR production accounted for about half of the world. Table 2-2 and Table 2-3 show the global and U.S. UPR production over the years respectively. Table 2-2 Global unsaturated polyester resin production by year: 1966 1972 1984 1994 1998 2000 Output/10,000 tons: 53 106 120 160 170 200 Table 2-3 Historical production of unsaturated polyester resin in the United States Year 1980 1985 1990 1995 1999 2000 Production/10,000 tons 42.6 55 55.8 72.4 94 lOO (Data source: China Unsaturated Resin Expert Database)

Unsaturated resin (1) Overview (3) Technology 1 Source: China Unsaturated Resin Network Unsaturated polyester resins (unsaturated polyester resins) refer to polyester polymers with unsaturated bonds (such as double bonds) in the molecular chain. Unsaturated dibasic acid (or anhydride), saturated dibasic acid (or anhydride) and glycol (or polyol) undergo a polycondensation reaction under certain conditions to form an unsaturated polyester. The unsaturated polyester is dissolved in a certain amount of cross-linking monomer (such as styrene) to form a liquid resin, which is an unsaturated polyester resin. When unsaturated polyester resin is added to the initiating system, it can react to form an insoluble and infusible polymer material with a three-dimensional network structure, so it is a typical thermosetting resin. Unsaturated polyester resin has its unique advantages compared with many other thermosetting resins. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that unsaturated polyester resin has good processing characteristics and can be solidified and molded at room temperature (not less than 15-20°C) and normal pressure without releasing any by-products. Moreover, the viscosity of the resin is relatively suitable, and a variety of processing and molding methods can be used, such as hand lay-up molding, injection molding, pultrusion molding, injection molding, winding molding, etc. Unsaturated polyester resin is known in the industry as contact molding or low pressure molding thermosetting resin. 1. Overview 3. Technical progress of unsaturated polyester resin (1) Theoretical progress ① Further understanding of the mechanism of unsaturated polyester polycondensation reaction process and rationally determining the staged reaction process are of great significance for obtaining high-quality products with uniform molecular chain structure. ②Predict and control the molecular weight of polyester polycondensation products through analysis, derivation, and calculation of polyester average molecular weight and molecular weight distribution. Hexcyclopentadiene and its derivatives are combined with UPR to reduce the molecular weight, thereby reducing the use of styrene. Foreign BYK Chemical Company has developed a new additive LPX 5500, which can reduce styrene volatilization by 70% to 90%. ③Resin modification and blending, resin modification through methods such as block, graft, copolymerization and interpenetrating network, and research results on the thickening mechanism of resin for sheet molding compounds and the action mechanism of low-profile additives by adding certain components and blending, have overcome the technical difficulties in SMC production, enabling large-scale, high-efficiency production of polyester molding compounds. ④Progress in structural design and calculation theory of composite materials, according to China Unsaturated Resin Network ( www.upr-e.cn ) According to experts, it provides theoretical guidance for product design and practical application. ⑤Composite material interface research has significantly improved the performance of composite materials, and a series of coupling agent products have been developed. ⑥Diversified research on initiators provides the possibility for the development of new processes, such as the curing and application of low-temperature and low-pressure SMC and water-emulsified system UP resin. ⑦The compound diversification of the polymerization inhibition system provides help for extending the storage period of UP intermediate products and stabilizing product quality. ⑧Various characteristic additives such as antioxidants, flame retardants, light stabilizers, surface isolators, wetting agents, thixotropic agents, coupling agents, etc. enrich the variety of resins. ⑨Application of computers in chemical synthesis, according to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that this provides convenience for the development of continuous production of unsaturated polyester resin.

Unsaturated resin (1) Overview (3) Technology 2 Unsaturated polyester resins refer to polyester polymers with unsaturated bonds (such as double bonds) in the molecular chain. Unsaturated dibasic acid (or anhydride), saturated dibasic acid (or anhydride) and glycol (or polyol) undergo a polycondensation reaction under certain conditions to form an unsaturated polyester. The unsaturated polyester is dissolved in a certain amount of cross-linking monomer (such as styrene) to form a liquid resin, which is an unsaturated polyester resin. When unsaturated polyester resin is added to the initiating system, it can react to form an insoluble and infusible polymer material with a three-dimensional network structure, so it is a typical thermosetting resin. Unsaturated polyester resin has its unique advantages compared with many other thermosetting resins. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that unsaturated polyester resin has good processing characteristics and can be solidified and molded at room temperature (not less than 15-20°C) and normal pressure without releasing any by-products. Moreover, the viscosity of the resin is relatively suitable, and a variety of processing and molding methods can be used, such as hand lay-up molding, injection molding, pultrusion molding, injection molding, winding molding, etc. Unsaturated polyester resin is known in the industry as contact molding or low pressure molding thermosetting resin. 1. Overview (2) New varieties of resin. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that in terms of resin varieties, traditional general-purpose resins, gel coat resins, chemical-resistant resins, flame-retardant resins, sheet resins, casting resins, molding resins, etc. are still the main types of resins, but new UP resins are constantly emerging through formula improvements and resin modifications. The technological development trend of unsaturated polyester in the world is mainly towards reducing resin shrinkage, improving product surface quality, improving compatibility with additives, increasing the infiltration of reinforced materials, and improving processing performance and mechanical properties through resin modification and blending. ①Low shrinkage resin. The use of thermoplastic resin to reduce and moderate the curing shrinkage of UPR has been widely used in SMC manufacturing. Commonly used low shrinkage agents include polystyrene, polymethylmethacrylate and diallyl phthalate polymers. At present, in addition to polystyrene and its copolymers, polycaprolactone (LPS 60), modified polyurethane and cellulose acetate butyl ester are also developed abroad. ②Flame retardant resin. Commonly used additive flame retardants include Al(OH)3, Sb203, phosphate ester and Mg(OH)2. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that currently Europe also uses the method of adding phenolic resin, while the United States also uses X-methyl phosphate and triethyl phosphate, both of which have achieved good results. ③Corrosion resistant resin. Commonly used corrosion-resistant resins include bisphenol A-type unsaturated polyester, isophthalic acid-type resin and rosin-modified unsaturated polyester. The 8250 vinyl ester resin developed by Japan's Ube Company not only has good corrosion resistance, but also has a storage period of up to 14 months. The domestically developed HET acid resin, aromatic alcohol resin and xylene resin have excellent corrosion resistance and are especially used in heavy anti-corrosion fields. ④Strong and tough resin. At present, foreign countries mainly use the method of adding saturated resin to improve toughness. Such as adding saturated polyester, styrene-butadiene rubber and carboxyl-terminated nitrile rubber. Amoco Chemical Company of the United States uses a resin made by reacting unsaturated polyester with hydroxyl groups at the end and diisocyanate, which can increase its toughness by 2 to 3 times. ⑤Low volatility resin. environmental protection in various countries * * Regulations strictly limit the release of styrene monomer and volatile organic compounds (VOC) during production. The general requirement is that the styrene content in the air around the workshop must be less than 50×10-6. Therefore, companies are working hard to develop new varieties that can meet regulatory requirements while having minimal impact on performance. Low styrene volatility resin is currently a topic being developed abroad. According to China Unsaturated Resin Network ( www.upr-e.cn ) experts introduced that the method is: Add film forming agent to reduce styrene volatilization ； A high boiling point cross-linking agent is added instead of styrene. ⑥Modification and blending of resins. A hybrid resin developed by the American Amoco Company is a two-component liquid resin. Component A is toluene diisocyanate and component B is low molecular weight isophthalic acid UPR. The hybrid resin has low viscosity for easy pumping and high filling, very fast cure, high elongation, high strength, high modulus and excellent corrosion resistance with low styrene escape. The resin is easy to process and can be used with all common processing techniques used for reinforced plastics, making it suitable for making large parts. Freeman Company has improved the formula of this resin to make it a castable polyurethane. Its biggest features are high hardness, non-stickiness on the surface when exposed to air during curing, high gloss, gel time of less than 2 minutes, and demoulding time of less than 10 minutes. Using blending technology to blend UPR and urethane, this material can use little or no reinforcing agents. It has high strength and flexibility, low styrene content, and can quickly process large parts using low-pressure processes like resin transfer molding (RTM). ⑦Resource-saving product development. According to China Unsaturated Resin Network ( www.upr-e.cn )Expert introduction, for example: Use cyclopentadiene to make low-cost resin, use recycled polyester waste to synthesize resin, etc. ⑧Degrade unsaturated resins. Due to the needs of environmental protection, some research on the degradation of unsaturated resins has also begun at home and abroad. It mainly introduces biodegradable structures such as polyethylene glycol, lactic acid, polycaprolactone, and N-vinylpyrrolidine into the molecular chain. In addition, many varieties of light-curing and radiation-curing UPR resins have been developed abroad. (3) New equipment and new processes ① Resin synthesis equipment is constantly updated to ensure the requirements of high-efficiency, high-quality automated processes. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that they adapt to the requirements of different resin processes and are designed with different heating systems, fractionation columns, and various solid raw materials are heated and melted before storage, transportation, and reflux. ②In terms of resin processing and molding, various molding methods have developed from hand lay-up and spray molding to bag pressing, injection molding, molding, winding, centrifugation, continuous plate making, pultrusion and other molding methods. There are more than 15 kinds of molding process equipment. The level of mechanization and automation has gradually improved, product quality has been stable, costs have been reduced, and high-efficiency production has been achieved. In particular, sheet molding compound (SMC) and bulk molding compound (BMC) technologies are becoming increasingly mature and can be used to mechanize the mass production of automobile shell parts and other industrial and daily necessities parts.

Unsaturated resin (1) Overview (2) Development 2 Unsaturated polyester resins (unsaturated polyester resins) refer to polyester polymers with unsaturated bonds (such as double bonds) in the molecular chain. Unsaturated dibasic acid (or anhydride), saturated dibasic acid (or anhydride) and glycol (or polyol) undergo a polycondensation reaction under certain conditions to form an unsaturated polyester. The unsaturated polyester is dissolved in a certain amount of cross-linking monomer (such as styrene) to form a liquid resin, which is an unsaturated polyester resin. When unsaturated polyester resin is added to the initiating system, it can react to form an insoluble and infusible polymer material with a three-dimensional network structure, so it is a typical thermosetting resin. Unsaturated polyester resin has its unique advantages compared with many other thermosetting resins. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that unsaturated polyester resin has good processing characteristics and can be solidified and molded at room temperature (not less than 15-20°C) and normal pressure without releasing any by-products. Moreover, the viscosity of the resin is relatively suitable, and a variety of processing and molding methods can be used, such as hand lay-up molding, injection molding, pultrusion molding, injection molding, winding molding, etc. Unsaturated polyester resin is known in the industry as contact molding or low pressure molding thermosetting resin. 1. Overview (2) Domestic Development my country’s UPR research work began in 1958 and can be roughly divided into several stages. According to China Unsaturated Resin Network ( www.upr-e.cn ) expert introduction, specifically it can be divided into: ①During the development stage (1958-1965), several universities and scientific research institutes successively carried out research work and established a number of pilot-scale production devices. ②During the development stage (1966-1990), Changzhou Building Materials Factory 253 introduced technology and equipment from the British Scott-Bader Company in 1966 and quickly put it into industrial production, thus laying the industrial foundation for my country's UPR. At the same time, Shanghai Xinhua Resin Factory and resin manufacturers in Tianjin introduced a number of technologies and equipment and built a number of industrial production devices. After forming a certain production capacity, a number of resin production enterprises were established in various places. In order to meet the demand for FRP products, we have successively developed and introduced some UPR resin varieties, and formulated a resin testing system. * * The standards have shortened the gap between my country's UPR industry and the world's advanced level. ③Growth stage (1990 to present), during which the average annual growth rate of my country's UPR exceeded 20%, which was much higher than the growth rate of GDP in the same period. ； According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that by 1999, the total domestic UPR production had reached 320,000 tons, and the UPR consumption in the domestic market had reached more than 400,000 tons, ranking among the top in the world. Table 2-4 shows domestic UPR production over the years. Table 2-4 Domestic UPR production over the years Years 1976 1980 1985 1990 1994 1997 2000 Production/10,000 tons 0.28 1.07 4.08 4.5 13 20 38 However, the current domestic UPR technology level and development * * There is still a gap in comparison. According to China Unsaturated Resin Network ( www.upr-e.cn )Expert introduction, the main performance is as follows: There are not enough varieties, low-quality and low-price varieties flood the mainstream market, high-end additives are dependent on imports, and the degree of mechanization of product deep processing technology is not high.

Unsaturated resin (1) Overview (4) Application sources: China Unsaturated Resin Network Unsaturated polyester resins (unsaturated polyester resins) refer to polyester polymers with unsaturated bonds (such as double bonds) in the molecular chain. Unsaturated dibasic acid (or anhydride), saturated dibasic acid (or anhydride) and glycol (or polyol) undergo a polycondensation reaction under certain conditions to form an unsaturated polyester. The unsaturated polyester is dissolved in a certain amount of cross-linking monomer (such as styrene) to form a liquid resin, which is an unsaturated polyester resin. When unsaturated polyester resin is added to the initiating system, it can react to form an insoluble and infusible polymer material with a three-dimensional network structure, so it is a typical thermosetting resin. Unsaturated polyester resin has its unique advantages compared with many other thermosetting resins. According to China Unsaturated Resin Network ( www.upr-e.cn ) Experts said that unsaturated polyester resin has good processing characteristics and can be solidified and molded at room temperature (not less than 15-20°C) and normal pressure without releasing any by-products. Moreover, the viscosity of the resin is relatively suitable, and a variety of processing and molding methods can be used, such as hand lay-up molding, injection molding, pultrusion molding, injection molding, winding molding, etc. Unsaturated polyester resin is known in the industry as contact molding or low pressure molding thermosetting resin. 1. Overview 4. Application of unsaturated polyester resin Unsaturated polyester was mainly used as coating and casting molding in the early days. After polyester FRP (glass fiber reinforced polyester) appeared in 1942, it developed extremely rapidly due to the huge advantages of FRP products and processes. According to China Unsaturated Resin Network ( www.upr-e.cn ) According to experts, the use of UPR resin is mainly divided into two categories: fiber reinforced and non-fiber reinforced. At present, FRP accounts for 70% to 80% of the total consumption of polyester abroad. In addition to hand lay-up method, FRP forming processing technology also includes winding method, cold molding method, low-pressure molding method and pouring method. In the late 1970s and early 1980s, the injection molding method was the main method in the United States, and the hand lay-up method was the main method in Japan, the United Kingdom, and France. In the mid-to-late 1980s, the traditional hand lay-up process showed a downward trend, the injection molding method increased year by year, and the molding molding also increased exponentially. Especially in recent years, with the development of the electronic appliances and automobile industries, the molding process suitable for these products has achieved significant development. At present, the foreign FRP processing industry is gradually developing towards mechanization and automation, and some special-shaped processing is still inseparable from hand lay-up molding. In the future, the injection molding method will mainly develop in the direction of high-pressure quantification of injection equipment. The compression molding method is mainly used for the processing of SMC and BMC, while the winding method is also used in XMC manufacturing in addition to being mainly used for tubes, tanks and pressure vessels. According to China Unsaturated Resin Network ( www.upr-e.cn ) According to experts, the continuous method generally refers to continuous resin impregnation, molding under a certain pressure, and then entering the 80 to 130°C curing zone. The processing pressure is 0.02 to 0.2MPa, and the transfer rate is 2 to 5m/min. American FRP is mainly used in automobile parts, pipelines, storage tanks, building materials, ships, etc. ； Japanese FRP is widely used in sanitary ware and industrial machinery, as well as containers, building materials, ships, automobile parts, etc. ； Europe's FRP pipe and storage tank technology is at the world's leading level. Table 2-5 shows the allocation of UP uses in the United States, and Table 2-6 shows the allocation of UP uses in Japan. Table 2-5 Consumption status of UP resin in the United States Year 19931995199720021997~2002 Growth rate/% Glass fiber reinforced general buildings 7.228.6310.0311.83.3 Bathtubs, etc. 6.587.178.6710.43.8 Anti-corrosion tanks and pipes 6.407.496.367.262.7 Ship 12.1213.5311.8913.42.4 Transportation 4.456.497.088.634.0 Consumer supplies 0.410.770.730.822.5 Leisure supplies 0.541.141.451 .774.0 Others 0.591.040.640.732.8 Various small parts 1.452.042.683.314.4 Others 1.631.041.141.323.0 Glass fiber reinforced subtotal 41.3649.3550.6759.473.2 Non-glass Resin for fiber reinforced coating 5.458.499.0811.124.1 Synthetic marble consumer products 1.541.771.822.002.0 Gel coating 2.813.093.544.092.9 Vehicle repair putty 2.182.091.952.132.0 Others 2.183.133.133 .633.0 Non-glass fiber reinforced subtotal 14.8018.5719.5222.933.3 Total 56.1667.9270.1982.403.3 Table 2-6 Consumption status of UP resin in Japan Year glass Fiber Reinforced Non-Glass Reinforced Total Building Industry Products Marine and Transportation Other Subtotal Coatings Coatings Laminations Subtotal 199410.714.512.312.0219.552.261.723.9823.531995 10.834.862.042.1119.842.311.663.9723.81199611.274.922.132.1720.492.431.584.0124.519 9710.814.492.152.1819.632.291.533.8223.45200211.504.502.202.2020.402.31.653.9524.35 http://www.upr-e.cn/uploadfile/jszy/uploadfile/200902/20090225082503693.gif The consumption of UPR in the field of non-reinforced products in my country has grown very rapidly in recent years, and its total consumption is close to that of FRP. In 1998, my country's unsaturated resins for FRP reached 140,000 tons, accounting for 56% of the total consumption, and unsaturated resins for non-reinforced products reached 110,000 tons, accounting for 44% of the total consumption. They were mainly used in arts and crafts, buttons, polyester panels, artificial panels and other fields, and a considerable share of the products were exported.: The approximate proportion of each product is shown in Table 2-7. Table 2-7 The proportion of UPR used in domestic non-reinforced products in 1998 Product type proportion/% usage/10,000 tons Product type proportion/% usage/10,000 tons Buttons 313.41 Agate/artificial stone 60.66 Handicrafts 343.74 Atomic ash 40.44 Polycarbonate 151.65 Others 30.33 Furniture coatings 70.77 Total 10011 (data source: China Unsaturated Resin Expert Database)

May I ask what the molding process of the material in your mechanical property table is? Hand lay-up, winding, molding, material thickness? Otherwise, this form would be meaningless.