Boron trifluoride is an important catalyst widely used in organic synthesis and petrochemical industry. It is used in many organic chemical reactions such as alkylation, polymerization, isomerization, addition, synthesis and decomposition. The reason why it has such a wide range of applications in catalytic reactions is that the boron electron layer structure has a strong tendency to form complexes, which is very important to produce catalytically active structures in acid catalysis. In many reactions, catalysts based on boron trifluoride are more active than halides of inorganic acid metals and do not cause adverse side reactions. As a catalyst, BF3 can be used in a variety of forms, such as in the gaseous state alone, or in conjunction with many types of inorganic and organic additives and its complex applications. At the same time, it can be recycled by distillation or chemical methods and reused after refining. BF3 and its compounds are used as curing agent in epoxy resin, dyeing polymerase fiber and making alcohol-soluble phenolic resin.

(1) Organic Synthesis Catalyst

BF3 plays a catalytic role in many organic syntheses. For example, in the industrial production of medium molecular weight PIB, BF3 catalytic system can not only simplify the production unit, shorten the production cycle, reduce labor intensity, but also significantly improve the yield of PIB.

(2) Ion Boriding

The term "boronizing" first appeared in literature in 1917, but detailed information on boronizing treatment and the properties of boronizing layers did not appear until more than fifty years later. Boronizing, or boronizing, is an austenitic chemical heat treatment applied to ferrous and non-ferrous materials to create a hardened layer containing borides on their surfaces. The hardness of boriding layer is up to 2000HV, and it has good wear resistance and corrosion resistance. Because boron trifluoride is easier to operate, does not need to be heated on the gas path, is more evenly distributed in the furnace, and because of its high boron content, it is often used as a carrier gas for boron in ion boriding.

(3) Used as Rapid Curing Agent at Room Temperature

BF3 is a fast curing agent for epoxy resin at room temperature. BF3 as curing agent must be separately packaged with epoxy resin and used with. The ratio error during operation affects the bonding quality and the process is complicated. At present, solid substances with different melting points are selected as the coating material, BF3 is made into micro-capsules, and the effect of epoxy resin and BF3 is blocked through the capsule wall, so as to make a single component product and stable storage. The release temperature is selected through the melting point of the capsule, and the BF3 curing agent is released in the capsule at this temperature, which is mixed with the epoxy resin to promote its rapid curing. The flexibility of cured epoxy resin can be improved by selecting the viscosity and molecular chain length of the capsule material.

(4) Applications in The Field of Nuclear Technology

The boron trifluoride 10-ether complex is reacted with calcium chloride to produce trimethyl borate, which is then hydrolyzed, and the obtained high-purity boric acid can be used as a neutron moderator in nuclear reactors.

Some complexes of BF3 enrich 10B in the form of 10 BF3, which can be used to separate isotopes of boron. 10BF3 can be used as a neutron absorption medium in proportional neutron counters in nuclear technology and for the control of nuclear reactors.

(5) Ion Implantation Source For Semiconductor Device Manufacturing Process

Boron trifluoride is used as ion implantation source in semiconductor device manufacturing process, which can improve the performance of semi-allogeneic devices.

When Group V atoms are doped in Group IV silicon atoms in the periodic table, they can conduct electricity because the outer electron has one more free electron. We call Group V impurities N-type impurities, and atoms that produce free electrons are called donors. When doped with Group III atoms, in contrast to the above, holes appear due to the absence of an electron. Inside this hole, neighboring electrons can jump in and move in sequence. This Group III impurity is called a P-type impurity, and the atom that produces the pore is called the acceptor.

In general, phosphorus and arsenic are used as N-type impurities, and boron is used as P-type impurities. Such impurities are called dopants, and the process of adding dopants is called dopants. Usually, the ratio of doped material is 106-107 silicon atoms doped with 1 impurity to form a conductive region.

The doping methods include thermal diffusion and ion implantation. The thermal diffusion method is to place the silicon wafer in the diffusion furnace and heat it to about 1000 ° C in the impurity gas temperament, at which time the impurity atoms will diffuse into the silicon crystals to form a conductive region. The gases commonly used in thermal diffusion are eborane (B2H6) for the P type and phosphine (PH3) and hydrogen arsenide (AsH3) for the N type.

Ion implantation is a technique that ionizes impurity atoms in a vacuum, accelerates them in an electric field, and then drives ions into a crystal. The gases used in ion implantation are boron trichloride (BF3), phosphine and hydrogen arsenide. The ion implantation method is less affected by impurities because it has an internal mass analyzer to select the required ions. In addition, the amount of ion implantation can be controlled by electric field regulation, and the concentration and location of ion implantation can be adjusted, so it is superior to the thermal diffusion method.

(6) Metallurgy and Welding

BF3 can prevent the oxidation of magnesium and its alloys during melt casting, and is used as a flux when welding magnesium. It is also used as a component of boron treatment agents for steel or other metal surfaces, and as a lubricant for cast steel. In the arc welding of titanium, if BF3 is involved, the weld will have strong impact resistance.

(7) Synthesis of Eborane

Borane can be prepared by BF3. It reacts with alkali metal hydrides to form ethoborane. Reaction with Grignard reagent to produce organoborate compound

(8) Medical Purposes

With the technological progress in the medical field, new antibiotic drugs are constantly being developed. The synthesis of these new antibiotic drugs requires boron trifluoride gas as a catalyst.