Process for separating formaldehyde and trioxane
    2.
    发明授权
    Process for separating formaldehyde and trioxane 失效
    甲醛和三恶烷分离方法

    公开(公告)号:US5872263A

    公开(公告)日:1999-02-16

    申请号:US431100

    申请日:1995-04-28

    摘要: A process for separating a gaseous reaction mixture in the preparation of trioxane is described, in which a) the gaseous mixture leaving the reactor is scrubbed in countercurrent with an organic solvent whose boiling point is above 135.degree. C. in which the trioxane predominantly dissolves and which leaves the formaldehyde predominantly in the gas phase which is returned to the reactor, b) the trioxane together with residual formaldehyde is stripped from the solvent by distillation via a column, the overhead product being partially condensed in the temperature range from 62.degree. to 100.degree. C. c) some of the resulting condensate is applied to the column as reflux and some is taken off as product and d) the non-condensed portion is returned to the scrubbing step a).

    摘要翻译: 描述了在三恶烷制备中分离气态反应混合物的方法,其中a)离开反应器的气体混合物与沸点高于135℃的有机溶剂逆流洗涤,其中三恶烷主要溶于其中, 其主要在气相中离开甲醛,其返回到反应器中,b)通过柱蒸馏将三恶烷与残余甲醛一起从溶剂中汽提,塔顶产物在62℃至100℃的温度范围内部分冷凝 c)将一些所得的冷凝物作为回流加到塔上,一些作为产物取出,d)将未冷凝的部分返回到洗涤步骤a)。

    Process for the preparation of polyacetal copolymers
    3.
    发明授权
    Process for the preparation of polyacetal copolymers 失效
    制备聚缩醛共聚物的方法

    公开(公告)号:US5587449A

    公开(公告)日:1996-12-24

    申请号:US521998

    申请日:1995-08-31

    CPC分类号: C08G2/24 C08G2/00 C08G2/28

    摘要: In the process for the preparation, with simultaneous end group stabilization, of polyacetal copolymers in a homogeneous phase and working up thereof, cyclic formaldehyde oligomers are copolymerized with cyclic acetals in the presence of an initiator in a polymerization reactor and immediately thereafter the initiator is deactivated by addition of basic substances, the unstable chain ends being degraded down to 0.01% to 1% in the presence of residual monomer, the product losing the majority of the residual monomer at the reactor outlet by letting down into a pelletizing device and the residual monomer which remains and the impurities dissolved in the product being removed by extraction with solvents and the product being pelletized, after drying and stabilization.

    摘要翻译: 在制备方法中,同时进行端基稳定化,聚缩醛共聚物在均相和加工中,环状甲醛低聚物在聚合反应器中在引发剂存在下与环状缩醛共聚,此后引发剂失活 通过添加碱性物质,在残留单体存在下,不稳定的链末端降解至0.01%至1%,产物通过放入造粒装置而丢失大部分残留单体,并将剩余的单体 其残留并且溶解在产物中的杂质通过用溶剂萃取除去,产物在干燥和稳定后被造粒。

    Continuous process for removing unstable components from crude
oxymethylene copolymer
    5.
    发明授权
    Continuous process for removing unstable components from crude oxymethylene copolymer 失效
    从原始甲基乙烯共聚物中除去不稳定成分的连续方法

    公开(公告)号:US5144005A

    公开(公告)日:1992-09-01

    申请号:US152170

    申请日:1988-02-04

    IPC分类号: C08G2/10 C08G2/28

    CPC分类号: C08G2/28

    摘要: Continuous process for removing unstable components from crude oxymethylene copolymer, which still contains catalysts, monomeric starting materials and unstable components, by treating the copolymer with deactivators, optionally in the presence of auxiliaries, in a pressure zone, and subsequently removing volatile components in a pressure-release zone in the presence or absence of stabilizers, in which process the crude polymer is fully melted in the absence of the deactivators and auxiliaries immediately after completion of the polymerization step, and the deactivators are subsequently incorporated, alone or together with auxiliaries, under pressure into the resultant polymer melt in at least one pressure zone.By this process, degradation is avoided and significantly better properties are obtained.

    摘要翻译: 通过在压力区任选地在助剂的存在下用失活剂处理共聚物,然后在压力下除去挥发性组分,从而仍然含有催化剂,单体原料和不稳定组分的粗制甲醛共聚物中除去不稳定组分的连续方法 在存在或不存在稳定剂的情况下,释放区域,在该方法中,在聚合步骤完成之后,粗聚合物在不存在失活剂和助剂的情况下完全熔融,随后将失活剂单独或与助剂一起加入到助剂中 在至少一个压力区中压入所得聚合物熔体。 通过该过程,可以避免劣化并获得显着更好的性能。

    Thermoplastic molding compositions on the basis of polyoxymethylenes
    9.
    发明授权
    Thermoplastic molding compositions on the basis of polyoxymethylenes 失效
    基于聚甲醛的热塑性成型组合物

    公开(公告)号:US4181685A

    公开(公告)日:1980-01-01

    申请号:US676927

    申请日:1976-04-14

    IPC分类号: C08G2/18 C08L59/00 C08L59/02

    CPC分类号: C08G2/18 C08L59/02 C08L59/00

    摘要: Thermoplastic molding compositions having improved properties are composed of a mixture of from 99.999 to 90% by weight of a linear polyoxymethylene and from 0.001 to 10% by weight of a branched or cross-linked polyoxymethylene. The linear polyoxymethylenes are homopolymers of formaldehyde or of trioxane or copolymers of trioxane and at least one compound of monofunctional reaction which can be copolymerized with trioxane. The branched or cross-linked polyoxymethylenes are copolymers of trioxane and a multifunctionally reacting compound, or copolymers of trioxane, a monofunctionally reacting compound and a branched or cross-linked polyether. The molding compositions yield shaped articles having improved mechanical properties.

    摘要翻译: 具有改进性能的热塑性成型组合物由99.999至90重量%的线性聚甲醛和0.001至10重量%的支链或交联的聚甲醛的混合物组成。 线性聚氧化甲烯是甲醛或三恶烷的均聚物或三恶烷与至少一种可与三恶烷共聚的单官能反应化合物的共聚物。 支链或交联聚氧亚甲基是三恶烷和多官能化反应化合物的共聚物,或三恶烷,单官能化反应化合物和支链或交联聚醚的共聚物。 成型组合物产生具有改善的机械性能的成型制品。

    Process for preparing oxymethylene polymers in a granular form
    10.
    发明授权
    Process for preparing oxymethylene polymers in a granular form 失效
    制备颗粒形式的甲醛聚合物的方法

    公开(公告)号:US4151346A

    公开(公告)日:1979-04-24

    申请号:US872441

    申请日:1978-01-26

    摘要: Oxymethylene polymers are obtained in a granular form by cooling a solution or dispersion of an oxymethylene polymer, the temperature of which solution or dispersion is above the sintering temperature of the oxymethylene polymer, to a temperature just below the sintering temperature of the oxymethylene polymer. As dissolving or dispersing agent as well as precipitating and cooling agent there is used a mixture of methanol and water having a methanol content of at least 75% by weight. The oxymethylene polymer obtained is suitable as engineering plastic for preparing moulded articles.

    摘要翻译: 通过将甲醛聚合物的溶液或分散体(其溶液或分散体的温度高于甲醛聚合物的烧结温度)冷却到刚好低于甲醛聚合物的烧结温度的温度,获得了颗粒形式的甲醛聚合物。 作为溶解或分散剂以及沉淀和冷却剂,使用具有至少75重量%的甲醇含量的甲醇和水的混合物。 所得到的甲醛聚合物适用于制备模塑制品的工程塑料。