reactive monomers for cationic uv curing -利来国际w66

 

目前为止，光引发自由基聚合体系应用最为普遍，但是它也有自己不可克服的弊端限制了其应用。自由基聚合在反应过程中会有氧阻聚，反应体系粘结性不好，体积收缩率高，导致产品尺寸精度降低，因应力的产生使材料发生变形，易破裂，在基材上有比较差的附着力。

so far the photo-initiated free radical polymerization system is the most widely used, but it also has its own insurmountable drawbacks that limit its application. in the process of free radical polymerization, there will be oxygen inhibition. besides, the reaction system has poor adhesion and high volume shrinkage, which may result in the reduction of dimensional accuracy of the product. the impact of stress may lead to material deformation, easy to break and poor adhesion on substrate.

对阳离子光固化体系的研究可以追溯到上个世纪，阳离子光固化有一系列自身独特的优点。首先，阳离子光聚合体系最大的优点是没有氧阻聚，不需要在一个惰性气体氛围中进行反应，既可以节省反应成本，又可以简化反应条件，克服了一直限制自由基光聚合反应的难题。阳离子光聚合是一个活性聚合反应，一旦引发聚合即使撤离光源也不会中止反应，有明显的后固化反应，使反应进行的更彻底，称之为“不死聚合”，适合厚度较厚的涂层固化，而自由基聚合则十分依赖光源，一旦离开光源反应立马停止；阳离子光固化体系中反应的单体或者聚合物一般不单能够发生双键聚合还能够发生开环反应，如环醚、乙缩醛、乙烯基醚类等等，反应物种类增加，且毒性比丙烯酸酯类单体或聚合物要低；阳离子光固化体系发生聚合开环反应体积会有一定膨胀，会补偿减小聚合过程中产生的体积收缩，对基材的附着力大大提高，改善光固化涂层的机械性能和热稳定性。阳离子光固化体系中常用的单体或者低聚物为乙烯基醚类，氧杂环丁烷类和环氧类。

research on cationic uv curing systems can be traced back to the last century, and cationic uv curing has a series of unique advantages. first of all, the biggest advantage of the cationic photopolymerization system is no oxygen inhibition. there is no need to carry out a reaction in an inert gas atmosphere, which not only saves the reaction cost, but also simplifies the reaction conditions. it also overcomes the problem that has always limited the free radical photopolymerization reaction. cationic photopolymerization is a living polymerization reaction. once the polymerization is initiated, the reaction will not stop even if the light source is removed. there is an obvious post-curing reaction, which makes the reaction more thorough. it is called "immortal polymerization" and suitable for thicker coatings. however, free radical polymerization is very dependent on the light source, because the reaction will stop immediately once it leaves the light source. the monomers or polymers reacted in the cationic uv curing system generally can not only undergo double-bond polymerization but also undergo ring-opening reaction, such as cyclic ethers, acetals, vinyl ethers, etc.. reactant types are increased and the toxicity is lower than that of acrylate monomers or polymers. after polymerization and ring-opening reaction, the volume of the cationic uv curing system will expand to a certain extent, which will compensate for the reduction of the volume in the polymerization process. it also helps greatly increase the adhesion to substrate and improve the mechanical properties and thermal stability of the uv-cured coating. commonly used monomers or oligomers in cationic uv curable systems are vinyl ethers, oxetanes and epoxies.

 

活性单体/reactive monomers

 

在光固化体系中，活性单体虽然在反应体系中占有比例不是最大的，但是它也是重要组成部分。一般活性单体的粘度比较低，它具有溶解光固化低聚物的作用，可以通过调节加入活性单体的量调整配方体系的粘度使其达到合适的状态；而且活性单体拥有光固化活性基团，可以作为反应物参与到聚合反应中，不会像溶剂一样残留在固化体系中，而且对光聚合反应速率，固化成膜的性质有很大的贡献，减少了有机溶剂挥发对环境的污染。因为自由基聚合不可克服的氧阻聚问题，我们将重点介绍可进行阳离子光固化的活性单体。

although the active monomer does not occupy the largest proportion in the uv curing reaction system, it is still considered as an important part. due to its relatively low viscosity, the active monomer has the function of dissolving the uv curable oligomer. the viscosity of the formulation system can be adjusted to a suitable state by adjusting the amount of the active monomer added. moreover, the active monomer has uv curing active group, which can participate in the polymerization reaction as a reactant and it will not remain in the curing system like a solvent. furthermore, it has a great contribution to the photopolymerization reaction rate and the properties of cured films. it also helps reduce the pollution of organic solvent on the environment. because of the insurmountable oxygen inhibition problem of free radical polymerization, we will focus on reactive monomers that can undergo cationic uv curing.

 

活性单体的种类十分丰富，按照官能团数量可以分为单、双和多官能度三类。活性单体的反应活性不但和官能度数相关而且与官能团的种类也是相关，且都是正相关，光固化速率会随之增大，转化率增高，表面膜的交联密度也会增大。

there are many kinds of reactive monomers. according to the number of functional groups, they can be divided into three types: mono-, bi- and multi-functional. the reactivity of reactive monomers is not only related to the number of functionalities, but also to the types of functional groups, and they are all positively related. the more functional groups they have, the higher the uv curing rate, conversion rate and cross-linking density of the surface film will be.

 

环氧类活性单体是现在应用比较多的一类单体，环氧类单体在光固化反应中, 发生开环反应，且固化后固化膜体积收缩小。体积收缩会导致产品尺寸精度的下降，而且因收缩产生的应力会引起材料的变形，破裂及在基材上较差的附着力，而环氧类活性光固化开环引起的体积膨胀刚好弥补了聚合产生的体积收缩，故其体积收缩小，具有优异热稳定性和机械性能。但是，环氧类的活性单体因为反应速率常数比较低，所以其反应速率比同官能团的丙烯酸酯类单体要低。但脂环族环氧反应速率比较快，且聚合产物具有较好的耐候性和电绝缘性，在阳离子光固化体系中应用十分广泛。

epoxy-based reactive monomers are a type of monomers which have been widely used now. these monomers will undergo a ring-opening reaction in the uv curing process and the volume shrinkage of the cured film is small. volume shrinkage may lead to a decrease in dimensional accuracy of the product. the stress generated by shrinkage may cause material deformation, cracking and poor adhesion on substrate. however, the volume expansion caused by uv curing and ring opening of epoxy-based reactive monomers just makes up for the volume shrinkage produced by polymerization, so it has excellent thermal stability and mechanical properties in addition to small volume shrinkage. the reaction rate of epoxy-based reactive monomers is lower than that of acrylate-based monomers with the same functional group. however, the reaction rate of cycloaliphatic epoxies is relatively fast and the polymer product has good weather resistance and electrical insulation, so it is widely used in cationic uv curing system.

 

氧杂环丁烷类活性单体的环张力（107kj/mol）类似于脂肪族环氧，只比脂环族环氧的环氧基的环张力略低一点，但氧杂环丁烷相比脂环族环氧的碱性强，因而氧杂环丁烷更容易发生阳离子开环聚合，其反应速率更快。单官能度氧杂环丁烷反应活性不低于双官能度的环氧甚至比其更高，而且氧杂环丁烷的粘度、毒性、挥发性和体积收缩都比较低，机械性能和热稳定性都性能良好，应用于uv涂料、油墨、电子封装、牙科树脂、3d打印等领域。

the ring tension (107kj/mol) of oxetane-based reactive monomers is similar to that of cycloaliphatic epoxies. it is only slightly lower than the ring tension of the epoxy group of cycloaliphatic epoxies. however, the basicity of cycloaliphatic epoxies is stronger than that of the oxetane, so oxetane is more prone to cationic ring-opening polymerization and its reaction rate is higher. the reactivity of mono-functional oxetane is not lower than or even higher than that of bi-functional epoxy. furthermore, the viscosity, toxicity, volatility and volume shrinkage of oxetane are relatively low, which attributes to excellent mechanical properties and thermal stability. applications include uv coatings, inks, electrical encapsulation, dental resins, 3d printing and so on. 

 

 

s-101

cas-3047-32-3

syna-epoxy 101是一种阳离子型、紫外线固化、活性、水溶性环氧稀释剂。

syna-epoxy 101 is a cationic, uv-curable, reactive and water-soluble epoxy diluent.

 

 

规格参数

syna-epoxy 101
外观	无色透明液体
粘度 @ 25℃	≤ 25.0cps
水分 (k.f)	≤ 0.1%
色度 (pt-co)	＜50
纯度 (g.c)	≥98.0%

 

specifications

syna-epoxy 101
appearance	colorless transparent liquid
viscosity@25℃	≤25.0cps
moisture (k.f)	≤0.05%
color (pt-co)	＜50
purity (g.c)	≥98.0%

 

 

产品应用

用于粘胶树脂和涂料，适用于电子和建筑材料的粘合剂，汽车涂料和其他绝缘材料。

product application

for adhesive resins and coatings, adhesives for electronics and building materials, automotive coatings and other insulation materials.

 

南通新纳希新材料有限公司可提供多款氧杂环丁烷类活性单体，如s-101、s-221等牌号已广泛应用于各行各业中，欢迎广大客户来电垂询！

 

nantong synasia new material co., ltd. can provide a variety of oxetane-based reactive monomers such as s-101, s-221 and other grades. these products have been widely used in many industries. welcome all customers to inquire!