January 17, 2024 Longchang Chemical

Crafting a Future of Resilient Materials with Polythiol Brilliance

1.1 Definition and Properties of Polymer Thiols

Sinomer® PETMP Monomer is an excellent sulfur ester antioxidant, with a high sulfur content per unit, and the pentaerythritol-containing structure exhibits excellent high-temperature resistance and resistance to water extraction, so it is especially suitable for polymer products that are susceptible to water impregnation or use in strict climatic conditions compared with traditional sulfur-containing antioxidants, such as antioxidants DSTDP and antioxidant DLTDP, and is also very valuable in polymer fiber applications when the R The high molecular weight structure of polymer fibers with more than 10 alkyl C atoms is also of great value.

1.2 Main uses of polythiols

Low viscosity polythiol, is a powerful chemical with a wide range of applications.
It can be used in the manufacture of coatings, sealants, adhesives and many other products. Today, we will introduce the characteristics and applications of low viscosity polythiol.
Low viscosity polymer mercaptan is a polymer compound with strong adhesion, characterized by low viscosity, high solid content and high chemical resistance. Due to its special structure and chemical properties, low viscosity polythiol is widely used in various fields.
Low viscosity polythiol is a very useful chemical with a wide range of applications and characteristics. If you have related manufacturing needs, you may want to try low viscosity polymer mercaptan, I believe it will add more value to your products.

1.2.1 Polymer mercaptan for epoxy resin curing agent

Adhesive is a viscose-based agent, with a variety of curing agents, plasticizers and fillers and other additives formulated with our daily life is closely related to the contact surface of the same material or even different materials for effective bonding of contact surfaces, usually used for bonding handicrafts, furniture repair, glass sealing, packaging, etc., in addition to the traditional areas of application, the adhesive in the wind power, electrical and electronic appliances, aerospace and other emerging areas of application. The development of adhesives in wind power, electronics and electrical appliances, aerospace and other emerging applications has a broad prospect. At present, under the guidance of relevant policies, adhesive products gradually to high-performance, environmentally friendly development, adhesive new applications more widely.

According to different molecular structures, adhesives can be divided into silicone adhesives, polyurethane adhesives, hot melt adhesives, epoxy resin adhesives, etc. Among them, epoxy resin adhesives can be bonded between metal and most non-metallic materials, and are widely used in construction, automotive, electronics, electrical appliances and daily household goods. For example, in the field of encapsulation of electronic and electrical appliances, epoxy resin potting adhesive can be used as a good encapsulation material due to its small shrinkage rate, good heat-resistant and electrical insulation properties, good sealing properties, etc. It can also enhance the durability of the encapsulation while improving the convenience and success rate of the encapsulation. Therefore, epoxy resin potting adhesive is the most widely used adhesive products in the field of electronic and electrical packaging.

Epoxy resin itself is a linear structure of thermoplastic resin, the performance is very stable, only by adding a curing agent, so that it by the linear structure crosslinked into a mesh or three-dimensional structure, in order to have excellent performance, and the performance of the curing product depends largely on the curing agent, so the curing agent is an essential part of the process of using epoxy resin. Epoxy resin curing agent is divided into a variety of types, according to different use scenarios with the appropriate curing agent, in order to play out the best performance of the epoxy resin system.

Epoxy resin curing agent is mainly divided into obvious type and latent type two kinds, obvious type curing agent is usually ordinary use of the curing agent, generally divided into amine, anhydride, phenolic, alkyd resin, polymer thiols, etc., this kind of curing agent either open the ring of the epoxy group through the addition and polymerization reaction, itself involved in three-dimensional mesh structure, either anionic way to make the epoxy group open the ring of the addition and polymerization, itself does not participate in the Mesh structure; latent curing agent means that after mixing with epoxy resin, it remains stable under certain conditions, but when it is exposed to special conditions (e.g., light, heat, moisture, etc.), the curing reaction starts to occur.

At present, in order to meet the demand for resin modification, the development of functional curing agents with excellent properties such as fast curing, low-temperature curing, toughening, flame retardant, etc., as well as low-toxicity, non-toxicity curing agents and curing agents adapted to special environments have become the focus of attention in the market. Polysulfanol is one of these functional curing agents, which can increase the speed of curing reaction to several times that of polyamine curing agents under the action of appropriate accelerators (e.g., tertiary amines), and is therefore irreplaceable in some specific areas. For example, it can cure quickly at low temperatures of about -10℃, so it is suitable for winter outdoor construction adhesives; its fast hardness development, low toxicity/non-toxicity, not easy to yellowing characteristics also make it in the “5 minutes” consumer adhesives and rapid repair adhesives have been widely used; as well as a strong adhesive strength, good toughness and so on. The advantages of mechanical properties also determine its important position in the epoxy resin curing agent. In addition, because of the sulfur flexible chain segment and high refractive index, the polythiol curing agent also has greater application value in transparent resin and toughening resin.

Due to the polythiol curing agent belongs to the special high-end field of epoxy resin curing agent applications, and technology is more difficult to break through, need to be closely integrated with the downstream application, so the global layout of this product is not many enterprises, foreign countries are mainly in the United States Huntsman, Japan, Toray, Germany, Bruno, Japan, such as SC Chemical as the representative of developed countries monopolized the market for a long time, and the domestic production enterprises of the field of development and research Ltd. and a few other enterprises have achieved mass production, and some of the products have been completely replaced by localization in some high-end fields.

PM839 is a low temperature fast curing agent for epoxy resin, with the appearance of colorless or light yellow transparent liquid, viscosity range of 12000~14000 mPa-s at room temperature (25℃), mercapto content ≥12, chromaticity ≤20, it can be used in the application fields of 5 minutes AB adhesive, electronic adhesive, metal epoxy putty, electronic thermal conductive adhesive, anticorrosive coating, silicone rod cutting adhesive and so on. Application fields. Among them, the silicon rod cutting adhesive generated by polythiol PM839 has high bonding strength and flexibility after curing, which can reduce the defects of silicon rod cutting process, such as dropping, edge chipping and cracking, thus improving the yield of the silicon rod cutting itself, and the silicon rod cutting itself can be detached quickly and easily after the silicon rod cutting is completed and the silicon wafers glued with adhesive can be quickly and easily detached after being immersed in warm water. According to the latest data from the National Energy Administration, China’s cumulative installed capacity of PV in 2022 has reached 392.61GW, with a new installed capacity of 87.41GW, hitting a new record high, and ranking first in the world for 10 consecutive years. According to China’s efforts to achieve carbon peak by 2030 and 2060 years ago to achieve carbon neutrality of the important declaration, the photovoltaic industry and other clean energy is in a period of vigorous development, the requirements for fine cutting technology will also continue to improve, will inevitably lead to the rapid growth of the demand for silicone rod cutting adhesive.

In addition, polysulfide PM839 can also be used to generate encapsulation adhesive, encapsulation is an important process in the production of electronic and electrical appliances, mostly non-removable, so the failure of the encapsulation means product obsolescence, the production of enterprises will have a negative impact. In the encapsulation process of electronic components, encapsulation adhesive can play a protective role for electronic components, not only to prevent moisture, dust and harmful gases and other factors on the erosion of electronic devices or electrical board, but also to slow down or offset external forces, vibration brought about by the damage, thus improving the stability of electronic devices. With the continued growth in demand for smart phones, smart homes and other electronic and electrical products, China’s electronic products market scale continues to expand steadily, will drive a steady rise in demand for electronic and electrical products on the adhesive.

We also introduced polythiol PETMP – tetrakis (3-mercaptopropionic acid) pentaerythritol ester, which is a fast-curing polythiol curing agent that can be applied in high-end adhesive fields such as orthodontic adhesives, quantum dot films, 3C electronic adhesives, UV optical adhesives, and so on. However, the odor problem of polysulfide has been troubling downstream customers. Longchang Chemical has now launched odorless polysulfide PETMP products, which further expands the application areas of the products and meets more diversified needs of customers.

1.2.2 Polysulfides for Optical Lenses
History of the evolution of resin lens materials
First generation: CR-39 (low-folding lenses)
Allyl diethylene glycol dicarbonate, which is the common CR-39 material nowadays, was initially developed by the American PPG company in the 1940s and gradually applied to the lens material of eyeglasses to improve the shortcomings of the glass material which is easy to be broken.CR-39 lenses have a high Abbe number, excellent optical performance, and the refractive index of 1.49, and now it has become the most widely used material in the low-folding lenses. Usually in the same degree, the lower the refractive index of the lens, the heavier the lens, the refractive index of only 1.49 CR-39 lenses will inevitably bring the problem of heavy wear to consumers, so the search for a higher refractive index of the lens material has become the focus of the research since then.
Second Generation: Acrylic, PC (medium and high refractive index lenses)
From the 1970s to 1980s, acrylic and PC were gradually used for eyeglass lenses, with a refractive index between 1.56 and 1.60, thus opening the second generation of resin lens materials, and becoming the representative material for medium-refractive-index lenses at present. pc has a low specific gravity and strong impact resistance, but has a low Abbe number of only about 29. Acrylic (PMMA, polymethylmethacrylate) is used as a lens material for eyeglasses, which is inexpensive and easy to process, but its Abbe number is low and its impact resistance is poor.
Third Generation: Polyurethane Material (High Folding Lens)
In 1987, Mitsui Chemicals first applied polyurethane materials to eyeglass lenses and named them “MR” lens materials, opening up the era of high refractive index lenses, the third generation of resin lens materials. Currently, Mitsui Chemicals has launched MR-8, MR-7/10, MR-174 and other polyurethane lens materials, with a choice of refractive indexes ranging from 1.60 to 1.74, to meet the different wearing needs of consumers. Compared with traditional resin lens materials, these lens materials have the advantages of high refractive index, low dispersion, light weight, wear-resistant and impact-resistant. At the same time, while maintaining high light transmission, the material’s haze index, ultraviolet ray blocking ability and other performances have been improved, and it has now become the industry’s first choice of materials for high-folding eyeglass lenses. A comparison of the relevant performance indexes of each lens material is as follows:

Performance comparison of different types of optical materials
Production process of polyurethane sulfide lenses
Polyurethane lenses have extremely high requirements for the purity, chromaticity, refractive index and other indexes of monomer materials, and the monomers required for the production of domestic high refractive lens materials basically rely on imports. At present, the lens material production adopts one-time heat curing molding process, which can be divided into two process steps: prepolymer production and polymerization curing. In the prepolymer production stage, the basic chemical raw materials in accordance with a certain formula proportion of mixing, supplemented by catalysts, specific temperature, environment, after a certain period of time after the polymerization reaction to generate larger molecules of prepolymer. In the lens curing stage, the prepolymers are injected into the lens molds and cured by polymerization for a certain period of time under a specific temperature and environment to form a solid lens substrate.
As far as the process of polyurethane lenses is concerned, polythiol and isocyanate are the core raw materials for the production of its base lenses. Specific process flow is as follows:

① monomer preparation: A component isocyanate and B component polythiol mix;

② material pouring and curing: using program temperature oven for the first time temperature curing;

③ molding, grinding, cleaning;

④ secondary curing: in the secondary curing oven to eliminate the internal stresses of the lens;

⑤ hardening, coating: the purpose is to improve the surface abrasion resistance and light transmittance.

Lens production process
Polyurethane lenses make use of the fact that sulfur atoms have both high molar refractive index and low molecular dispersion. By introducing sulfur atoms into resin lenses through polymerization of mercaptan, the refractive index of the lenses can be greatly increased under the prerequisite of meeting the Abbe number of >30. At present, the main suppliers of polymerized mercaptan are Mitsui Chemicals Co., Ltd. and its Korean KOC and Yifeng New Materials Co., Ltd. Both companies hold the core technology, and the quality control of the products and the application technology have reached the world’s excellent level. The main suppliers of isocyanate are Wanhua Chemical, Japan Mitsui, Germany Kostron and other enterprises, compared with polymerization of mercaptan, lens manufacturers have more selectivity for isocyanate.
The process of domestic substitution of polythiol
As the key material to determine the refractive index of lenses, polymer mercaptan has been monopolized by foreign head enterprises for a long time, and foreign enterprises have almost completely grasped the pricing right of the market of high refractive lens materials. The process of localization and substitution of polymer mercaptan is of great significance to the development of resin lens industry while enhancing the independent supply and guarantee ability of new materials in China.
Longchang Chemical, as an enterprise focusing on the R&D, production and sales of new optical materials, has developed two monomer materials of 1.60/1.67 high refractive index spectacle lenses, namely BMPT and PETMP, which broke the long-term monopoly of foreign countries on the polymerization of polymer thiols for optical lenses.
In addition, Longchang Chemical also has the corresponding production technology of polysulfide optical resin material, which is the key monomer for the production of 1.71 and 1.74 refractive index resin lenses. It is expected that Longchang Chemical will put the device into production in the next two years and realize the industrialized production to meet the market demand for ultra-high-refractive index resin lens monomer materials. The edge thickness of the lens is 1/3 thinner than that of ordinary lenses with low refractive index, and the impact strength is 6 times higher than that of ordinary lenses.

2、What is the difference between polymerized mercaptan PM83 PETMP BMPT?

Polymer mercaptan BMPT is 1.67 refractive index optical resin material special mercaptan, can be used in optical resin lenses, transparent materials and other fields. It is characterized by high refractive index and good light transmission, and can be used with matching products to obtain high-end resin lenses with high refractive index, high light transmission, strong toughness, anti-blue light, and easy coloring.
PETMP is a special mercaptan for 1.60 refractive index optical resin material, which can be used with matching products to obtain high-end resin lenses with high refractive index, high light transmission, strong toughness, anti-blue light and easy coloring. It can also be used as modifier and cross-linking agent in the polymerization reaction of UV coatings, inks and adhesives, as well as acidic ion exchange catalyst and low temperature curing agent.
Polysulfide PM839 products are mainly used in epoxy resin primer fast curing agent, industrial coatings, electronic adhesive, optical adhesive and other fields.

3.1 Market Demand Analysis of Polythiol 405:

Versatility and Applications:
Demand for polythiol 405 is driven by its versatility, which can be used in various industries such as pharmaceuticals, chemicals, and polymers. The demand for polythiol 405 is driven by its use as a cross-linker in polymers, especially in the production of specialty rubbers. In addition, it finds application in the pharmaceutical industry as a reactant for synthesizing certain drugs, further enriching its market demand.

Growth of Polymer Industry:
The growth of the polymer industry is largely influencing the demand for polythiol 405. As various industries are increasingly adopting polymers in various applications, the demand for crosslinkers such as Polysulfanol 405 has increased. This is particularly evident in the production of elastomers and specialty rubbers, where this compound plays a vital role in improving the mechanical and thermal properties of the end product.

Pharmaceutical applications:
Demand for polythiol 405 from the pharmaceutical industry has increased due to its use in drug synthesis. With the expansion of pharmaceutical R&D activities, the demand for specialized compounds such as Polysulfanol 405 is also growing. The use of Polysulfanol 405 as a reactant in certain drug synthesis processes makes it a key component in the pharmaceutical supply chain.

Global Trends in Specialty Chemicals:
Global trends in the specialty chemicals industry are also impacting the demand for polythiol 405. As industries focus on developing high-performance specialty chemicals for specific applications, the unique properties of polythiol 405 make it a sought-after ingredient. Its compatibility with a variety of chemical processes and applications makes it an important ingredient in the production of specialty chemicals.

R&D Programs:
Ongoing R&D activities are contributing to the market demand for polythiol 405. Various industries have invested in exploring new applications and formulations, which has led to increasing adoption of polythiol 405 in emerging industries. Continuous exploration of its potential applications is further driving its market demand.

3.2 Competition in the market for polythiol 405:

Competition in the market for Polysulphanol 405 is influenced by a number of factors including the presence of key players, product differentiation, and industry regulations. Analyzing the competitive landscape provides insights into the positioning of companies in the market.

Key Players and Market Share:
The polysulfoethanol 405 market is characterized by the presence of key players that dominate the industry. These companies typically hold a significant market share by virtue of their well-established market positions, strong distribution networks, and robust R&D capabilities. Competition among the major players revolves around maintaining and expanding market share through strategic initiatives.

Product differentiation strategy:
Competitive differentiation is crucial in the polythiol 405 market. Companies strive to differentiate their products by focusing on factors such as purity, quality, and formulation technology. Customization of formulations as per specific industry requirements is also a part of product differentiation strategy. This enables the companies to fulfill different application requirements and gain competitive advantage.

Global and Regional Market Dynamics:
Competition in the polythiol 405 market is influenced by global and regional dynamics. Global players may dominate the entire market, while regional players tend to focus on specific regional markets where they have a stronghold. Understanding and adapting to regional market trends and regulations is critical for companies to maintain a competitive edge.

Regulatory compliance and sustainability:
Compliance with industry regulations and sustainability factors play an important role in competing in the market. Companies that comply with environmental and safety regulations while ensuring that production processes are sustainable will gain a competitive advantage. Consumers and industry are increasingly prioritizing products that meet environmental and regulatory standards.

Investment in innovation and research:
Competition in the marketplace is driven by continued investment in innovation and research. Companies that invest in developing new formulations, improving manufacturing processes and exploring novel applications for Polysulfan 405 position themselves as industry leaders. In a competitive market environment, innovation becomes a key differentiator.

In conclusion, the market demand for polythiol 405 is influenced by its wide range of applications in various industries, with the polymers and pharmaceuticals industries being the major contributors. The competitive landscape is characterized by key players focusing on product differentiation, global and regional dynamics, compliance, and continuous innovation to maintain and expand their market share.

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