主题：【无卤专题讨论】关于BFR和CFR

BFR：Brominated Flame Retardants溴化阻燃剂
CFR：Chlorinated Flame Retardants氯化阻燃剂

要做到不含BFR和CFR，就应积极寻找合适的代替品，但就目前来讲成本可能要增加100%--200%。

尽量减少使用或寻找替代品

原文由 jiping_111 发表:
尽量减少使用或寻找替代品

这个等于没说，客户有要求了，当然不能使用，要寻找替代品。那具体怎么做呢？

大家一起来提高提高英语，呵呵

WHAT ARE BROMINATED FLAME RETARDANTS? WHAT ARE THEY USED FOR?

The introduction of 'new materials'

Today, we live in a modern society where we are surrounded by many consumer products, made out of flammable materials such as oil-based plastics and synthetic materials.

Brominated Flame Retardants (BFRs) are chemicals commonly used in many domestic and industrial appliances and equipment such as computers, TV's, mobile phones, furniture, insulation boards, mattresses and many more others. 90% of electrical and electronic appliances contain BFRs. BFRs are used to increase their resistance to fire. Flame retardants give up to 15 times more time to scape when there is a fire. BFRs are also used in textiles for upholstered furniture.

For an overview of the applications of the different brominated flame retardants, please click here.

Protecting peoples' lives



In 2000 in the US, there were more than 4,000 deaths in fires. It is estimated that at least 280 lives were saved thanks to the use of Brominated Flame Retardants alone.
In Europe, the EU Commission has estimated a 20% reduction of fire deaths as a result of the use of flame retardants in the last 10 years.
In the United Kingdom , government scientists have estimated that more than 3,000 lives were saved in the period between 1988 - 2000 as a result of Flame Retardants, in particular BFRs. The UK and Irish Furniture Fire Safety Regulations from 1988 provide the UK consumer with the highest levels of fire safety protection in the world.


Providing Safety in the Home



The development of flame retardants has made possible the safe use of a wide range of materials and consumer products. Flame retardants are chemicals which are added to materials, either during or after manufacture, and because of their chemical nature reduce both the chances of the material igniting and, if they do, they slow the rate of combustion. The use of flame retardants in the manufacture of electronic equipment, upholstered furniture and textiles has been shown to save lives from fire.


After many years of serious fires involving upholstered furniture (such as sofas), in 1988 the UK passed legislation requiring such furniture to meet a higher flammability standard, which required both the fillings and covers of most upholstered furniture to be flame-retarded. The legislation has proved highly effective as older furniture is replaced by new, safer furniture.

However the UK is still one of the only countries in Europe to require the use of high levels of fire safety in upholstered furniture.
Similarly in the case of televisions, the introduction of a higher fire safety standard in the US for television enclosures has led to a 73% decrease in the incidence of fires involving televisions.

Yet, in Europe, where no such high standard exists, fires involving televisions, with resultant deaths and injuries, have continued to climb.


Providing Safety in Public Places

Flame retardants are not only important in the home, they also ensure the fire safety of many public places. In modern facilities such as cinemas and theatres, it is almost inconceivable that the textile furnishings would not be flame-retarded. The same applies to many forms of transport, including cars, airplanes and train furnishings. But flame retardants are perhaps most important in protecting people where they are at their most vulnerable, in schools, homes for the elderly, and hospitals.

How do Flame Retardants work?

Fire is a chemical reaction between oxygen and a fuel, triggered by an ignition source or heat. Brominated Flame Retardants (BFRs) are in many circumstances the most effective chemical to prevent ignition or a fire from developing. Basically, BFRs inhibit this chemical reaction from taking place and in that way prevent a fire from developing.



When Flame Retardants started to be used

Chemical flame retardants have been used since Roman times when they were used to prevent seige towers from catching fire. The first patent on a flame retardant was British Patent 551 to Obadiah Wilde in 1735 to flame retard canvas for use in theatres and public buildings. In the plastics industry they were first used in cellulose nitrate which was extremely inflammable. In the early '70s, the increasing use of flammable materials such as plastics in electrical equipment or synthetic fibres in sofas and curtains led to the wider use of flame retardants. Manufacturers of furniture and appliances began to move away from traditional materials such as wood and metal towards new materials such as plastics for appliances and polyurethane foam and fibre-based fillings for furniture. While these new materials provided many benefits, they had one problem - they were far more combustable than the materials they replaced, which meant they would both catch fire more easily, and once alight, combust more rapidly, giving people little time to escape. Flame Retardants are able to contribute greatly to reducing the risk of fires providing safety in the home and in public places.



Different types of flame retardants

There are a number of different "families" of flame retardants:

Brominated flame retardants

Chlorinated flame retardants

Phosphorous-containing flame retardants

Nitrogen-containing flame retardants (i.e. Melamines)

Inorganic flame retardants
The choice of a given flame retardant frequently depends on the type of application. Their suitability is subject to variables such as the material to be flame-retarded, the fire safety standards with which the product must comply, cost considerations and recyclability.



Halogenated flame retardants

Bromine, chlorine, fluorine and iodine, are the elements in the chemical group known as halogens. The word halogen derives from Greek, meaning 'salt-former', because these elements are commonly found in nature reacted with metals to form salts. For example, sodium chloride, or table salt, is the most common example of a halogen salt.

Halogenated flame retardants act in the vapour phase. That is they actually interfere with the chemistry of the flame to prevent it from propagating. Chlorine and bromine are both effective in this role. Fluorine is too stable to be an active flame retardant and iodine based compounds are too unstable to be flame retardants.

Chlorinated flame retardants are mainly used in plastics. They offer good light stability but compared to brominated flame retardants, higher quantities are needed for achieving comparable flame retardancy.

Brominated flame retardants are often the most effective flame retardant when both performance and cost are considered.



Why is bromine effective as a flame retardant?

In general the stability of bromine in a typical flame retardant molecule means that they can offer the highest activity as a flame active retardant as well being very cost effective. The choice of flame retardant systems for any particular application will depend on how the material decomposes in a fire, as well as the physical properties required. BFRs, because they act in the flame, can be used in just about every application, indeed in some plastics and uses they may be almost the only choice.

The fact that BFRs are particularly efficient on an addition level basis means that frequently they may have less impact on the physical properties of a plastic than other systems. There are also a wide range of BFRs available. These enable a formulator to select the optimum product to balance cost with physical properties, temperature resistance, processing characteristics and all the other important characteristics a particular end use may require.



Different types of Brominated Flame Retardants (BFRs)

Among the many BFRs used in the world the main commercial BFRs are the following:

TBBPA: Tetrabromobisphenol -A

HBCD: Hexabromocyclododecane

Deca-BDE (Decabromodiphenyl ether)

Brominated polymers such as brominated epoxy, brominated polystyrene, brominated polycarbonate, poly (brominated acrylate), and brominated polyols.

Octa-BDE (Octabromodiphenyl ether) - Phased out in Europe

Penta-BDE (Pentabromodiphenyl ether) - Phased out in Europe

PBB: Polybrominated biphenyls - Phased out in Europe
Each of these Brominated Flame Retardants have very different properties.



Brominated Flame Retardants (BFRs) and the environment

The important contribution of BFRs in protecting our environment is often not known. For instance, according to a life cycle assessment (LCA), the use of plastics flame retarded by BFRs reduces dramatically the emissions of toxic substances such as polyaromatic hydrocarbons (PAH) and dibenzodioxins and furans.
Several studies have also found that recycling of plastics containing brominated flame retardant fully meets the German Dioxin Ordinance requirements. It was also found that this could be easily done to comply with the German Worker Health and Safety requirements.
Moreover it has also been shown that recycling of plastics containing BFRs is preferable in terms of stability and flame resistance. The same can be said about the incineration of plastics containing brominated flame retardants.

环保已经指明了方向,应该将来的趋势是向这个方向发展的.


"磷氮系的膨胀型阻燃剂及氮基阻燃剂将进一步得到发展和受人青睐；无毒、抑烟的无卤无机阻燃剂，如改性的氢氧化铝、氢氧化镁、硼酸锌等，特别是可用于较高温度的氢氧化镁，将进一步得到开发；抑烟剂的市场前景看好；阻燃剂领域呼唤更多的法规和标准问世。"

溴化阻燃剂(BFRs)是在生产中普遍使用的工业化学制剂,种类繁多.近几年,在环境生物体内检测到几种BFRs,如多聚溴化二苯醚(PBDEs)、四溴双酚A(TBBPA)及其衍生物、六溴环丙烷十二烷(HBCD)、多溴二苯联苯(PBBs)等.

  溴系阻燃剂（BFR）是消费量最大的有机阻燃剂，其全球总用量达250~300kt/a，占阻燃剂总量的15%~20%。目前，全球电子电气产品所用的阻燃剂，仍有80%是BFR。
  BFR的生产和使用已有30多年历史。当前全球规模生产的BFR约有70多种，主要是十溴联苯醚（DBDPO）、四溴双酚A（TBBPA）和六溴环十二烷（HBCD），前两者的产量占BFR总产量的50%。
  目前，聚合型溴系阻燃剂主要为溴化聚苯乙烯（Brominated Polystyrene, BPS）、聚溴化苯乙烯、溴化环氧树脂齐聚物（Brominated Epoxy Oligomer，BEO）、溴化聚碳酸酯低聚物（Brominated Carbonated Oligomer，BCO）、聚溴化基丙烯酸酯（Poly(pentabromobenzyl acrylate)，PPBA）等。通过分子量控制，可形成适用于不同树脂基体的阻燃剂系列。
    溴化聚苯乙烯是聚合型溴系阻燃剂的主要品种之一，包含聚溴化苯乙烯（Polybrominated styrenics，PBS）和溴化苯乙烯的低聚物。市场上的主要产品包括Albemarle公司的SAYTEX® HP-3010、HP-7010、PYRO-CHEK®68PB；ICL公司的FR803P、F-2000、F-2100、F-2200、F-2400、F-3100、Phenoxy-terminated carbonate oligomer of TBBA、FR-1025；Chemturo的BC-58、BC-52等。

虽然欧盟RoHS禁令明确禁用多溴联苯和多溴联苯醚类阻燃剂后，又于2005年10月15日豁免了十溴联苯醚，但是采用十溴联苯醚不是唯一选择，也不都是最佳选择，仅仅是性价比较高的一种选择。溴系阻燃剂的发展出路应以生产和应用绿色环保化为前提，从产品结构研究入手，开发综合性价比较高的环保型阻燃剂。Albemarle、Chemturo、ICL（原DSBG）等公司已相继规模化生产环保型溴系阻燃剂系列产品，可替代受限的多溴联苯和多溴联苯醚类阻燃剂。
  BFR有诸多的缺点，但由于BFR高性价比在阻燃领域内占据举足轻重的地位。在很多应用领域，还难以找到BFR的代用品。
  为此，欧美、日本等发达国家和地区相继颁布了诸多法令，强制使用者使用无毒化和环境友好化阻燃剂，通过法令或法规的限制达到下游产品无害化的目的。
  虽然困扰阻燃行业多年的十溴联苯醚的问题得到解决，但是我们仍不得不面对溴系阻燃剂所带来的潜在危害。尽管法令和法规上已经不再限制十溴联苯醚的使用，但是其溴化物结构仍使人们对其有所禁忌。万客化工在线各国阻燃行业的技术人员也都在考虑解决方案，努力寻找真正无毒化和环境友好化的阻燃剂或是目前溴系阻燃剂的替代品。
  磷系阻燃剂是业内人士考虑的主要产品，虽然已成功研制出磷系无卤阻燃PC/ABS合金、无卤阻燃PA及无卤阻燃PC。DOPO、BDP、RDP、PX-200、201、202等均是这类阻燃剂的代表产品。但是这些无卤阻燃材料价格较高，且物理性能有一定幅度的下降，仍需优化其性能、降低成本。
硅系阻燃剂则是另一类受关注的无毒化阻燃剂。该阻燃剂在阻止PC燃烧方面十分有效，且阻燃PC的物理性能与未阻燃PC非常接近，但价格没有较大的竞争优势。
  除采用添加阻燃剂的方法外，进行树脂的分子设计，设计出具有阻燃性能的树脂材料也是高聚物阻燃方法之一。或者共聚或者共混等材料改性，均可达到使材料本身阻燃的效果。如将PS与PPO共混，即使不添加阻燃剂，也可提高PS的阻燃性。而PC与聚硅氧烷的共聚物，则具有优异的阻燃性能，物理性能又几乎与典型的PC相同。
  此外，通过纳米无机材料与树脂基材复合的方式也可达到使材料阻燃的目的，并且纳米无机材料还具有良好的增强作用，增加聚合物材料在自然条件下的崩解速度，扩大与有机霉菌的接触面积，有利于环境降解。美国Cornell大学及美国国家技术和标准局（NITC）的研究已证明，由PC、PA6及接枝顺丁烯二酸酐的PP与粘土制备的插层型聚合物/粘土纳米复合材料的释热速度（HRR）峰值，比纯聚合物大为降低。PS/粘土纳米复合材料释热速度的降低幅度可与十溴联苯醚/三氧化二锑（PS常用的阻燃剂）含量很高的PS相比。对纳米复合材料，只需加入很少量（3%~6%）的无机物，即可获得阻燃性。将PS与经双（二甲基）双（十八烷基）卤化铵改性的蒙脱土熔融共混，即可制得具插层结构的纳米复合材料。将粘土用烷基铵盐处理，除去粘土上的钠离子，即形成亲有机的，而不是亲水的粘土。锥形量热仪测定表明，树脂/粘土纳米复合材料之所以具有阻燃性，是由于它热分解时能形成炭层，而后者可作为隔绝层，减缓可燃烧料由高聚物逸出。
  虽然出现了大量的无卤阻燃方案，但都存在一个共同的问题，即新的阻燃材料价格比溴系阻燃材料有较大提升。因此，溴系无毒型阻燃剂也成为替代现有具有潜在性危害的溴系阻燃剂的一种方式。聚合型溴系阻燃剂较好地解决了原溴系阻燃剂可能产生多卤代二苯并二恶烷及多卤代二苯并喃的这一问题，成为一种新型的环保型阻燃剂。