Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L81/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing sulfur with or without nitrogen, oxygen or carbon only; Compositions of polysulfones; Compositions of derivatives of such polymers
  • C08L81/04—Polysulfides

Definitions

• the invention relates to a ner process for the production of preferably liquid prepolymers based on polysulfides and polyepoxides, and to the prepolymers produced by this process.
• prepolymers are made by reacting polysulfides e.g. B. the general formula
• polyepoxides can be implemented with a wide variety of polyepoxides. Since the index x 2 and the indices n and y can be zero and mainly bisepoxides are used as polyepoxides, polysulphides which have two epoxy end groups also belong to the disclosure of this patent. However, the products obtained there by reacting polyepoxides with polysulfides are not suitable as liquid, durable polymers, as will be explained in more detail below.
• the ner driving according to US Pat. No. 2,789,958 can be carried out without the presence of catalysts. In this case, a mixed mixture is created.
• reaction of the epoxides with the polysulfides can, however, also be carried out in the presence of aliphatic amines such as ethylenediamine, methyldiethanolamine, etc., as a catalyst, according to the teaching of this American patent.
• aliphatic amines such as ethylenediamine, methyldiethanolamine, etc.
• EP 0 171 198 B1 describes a ner process with reference to US Pat. No. 2,789,958, in which an epoxy resin with an epoxy group content of 2 to 6 mol / kg with a polymer having mercaptan end groups with at least 2 mercaptan groups per molecule and one molecular weight does not have 2,000 implemented and thereby a curable liquid block copolymer is obtained, which can be referred to as a prepolymer.
• the reaction must be carried out in a stoichiometric excess, ie the molar ratio of epoxy / mercaptan groups should be in the range from 2: 1 to 7.5: 1 in the case of epoxy-terminated prepolymers or in the case of mercapto-terminated prepolymers in the range 1: 1, 5 to 1: 3.
• the reaction should be carried out in the absence of a catalyst or curing agent.
• the prepolymers described there which can also be referred to as block polymers, are, as can be seen in this document, after about 1-2 weeks of approximately stable viscosity and can only be stored, but leave something to be desired in terms of their uniformity , In this way it is not possible in many cases to carry out targeted hardening which leads to end products with certain desired properties.
• the implementation also takes a disproportionately long time. It has been shown, as can be seen from the examples in EP 0 171 198 B1, that a longer period of time is required to obtain a stable product.
• Example 2 the mercaptan content there did not drop to 0 until after one week's storage at 40 ° C.
• the mercaptan content only decreased to 0 after 16 days when stored at room temperature.
• the object of the invention is therefore to provide a ner process for the preparation of prepolymers with epoxy end groups or SH end groups by reacting polysulfides and polyepoxides which are particularly uniform with regard to their end groups and which are particularly suitable for further processing by means of curing.
• Another object of the invention is to provide prepolymers with epoxy end groups or SH end groups, with which it is possible to produce tailor-made end products with properties defined in advance.
• the object of the invention is also to provide a ner process for the production of product mixtures with uniform functionality.
• the object of the invention is also to provide a ner method in which not only are products with uniform bifunctionality produced, but also with which it is possible to obtain uniform products which are higher than bifunctional in terms of mercapto groups or epoxy groups Contain proportions of tri- or higher functional prepolymers.
• polysulfides with polyepoxides by reacting polyepoxides with polysulfides which have at least 2 mercapto groups in the presence of quaternary ammonium compounds as a catalyst.
• Preferred polyepoxides are compounds of the formula
• R '' or R ''' is an organic radical with an aliphatic, aromatic or cycloaliphatic basic structure.
• R '"or R" is preferred
• Epilox resins are e.g. B. from the company Leuna-Harz GmbH, D-06237 Leuna, Bakelite epoxides such as Rütapox ® resins from Bakelite AG, D-47125 Duisburg and Araldite resins from Vantico CH-4002 Basel.
• Polysulfides of the following formula are preferably used as polysulfides
• the reaction is advantageously carried out in a molar ratio of 1 mol of polysulfide to 2 ⁇ 0.2 mol of polyepoxide or in a molar ratio of 1 mol of polyepoxide to 2 ⁇ 0.2 mol of polysulfide, an exact stoichiometric ratio of 1: 2 or 2: 1 is preferred.
• the starting component determining the functionality of the prepolymer is used in a stoichiometric excess, which, for. B. can be up to 2 - to 7 times or more.
• Methyltrioctylammonium chloride is preferably used as the catalyst. This product is commercially available as Aliquat 336.
• the catalyst is used in catalytic amounts.
• the amount depends on the selected reaction temperature and the reactivity of the epoxides used and can be determined by a person skilled in the art by simple preliminary tests. In general, 0.01 to 0.5% by weight, based on epoxy, is sufficient. Higher or lower quantities are possible.
• Bisphenol A diglycidyl ether and bisphenol F diglycidyl ether and mixtures thereof are particularly suitable as polyepoxide.
• Polypropylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether and mixtures thereof are also very suitable.
• the polysulfide is introduced and polyepoxide is metered in for the preparation of mercapto-terminated prepolymers.
• the polyepoxide is initially introduced and polysulfide is metered in.
• the reaction of the starting products according to the process according to the invention can be carried out at room temperature, but it is preferred to work at higher temperatures.
• a temperature range of about 20 to 150 ° C is generally suitable for carrying out the reaction. Is preferably carried out at a temperature of 40 to 150, in particular from 40 to 100, preferably 50 to 70 ° C.
• reaction components together with the catalyst directly into a reaction vessel and to allow them to react completely.
• the invention further relates to prepolymers which can be prepared by one of the processes specified above.
• the functionality and viscosity achieved after completion of the reaction remain stable.
• the product can therefore be forwarded immediately to the end processor and retains the guaranteed properties unchanged for a long time and can be reproducibly processed into products with a defined property profile. Even if a substantial excess of polyepoxides or of starting products containing mercapto end groups is used, the reaction mixture remains constant after a relatively short reaction time and no longer changes its properties. This makes it possible to specifically produce an end product with a defined content of epoxy or mercaptan end groups.
• the prepolymer obtained is thus very uniform as far as the functional groups are concerned, and it is also possible to set the proportion of functional groups per unit weight of end product in a wide range; it can be used very advantageously in further processing, e.g. B. also as an internal plasticizer for corresponding polymers.
• the prepolymer is extremely curable with the usual hardeners and thus leads to very uniform cured products.
• polyamines, polythiols or other conventional compounds with at least two reactive hydrogen atoms can be used as hardeners.
• customary oxidizing agents such as, for. B. manganese dioxide, hydrogen peroxide or organic peroxy compounds are used.
• a mixture of 765 kg of epoxy resin Epilox T 1927 (equivalent weight 180 g / eq) and 225 kg Epilox P 1320 (equivalent weight 150 g / eq) and 0.5 kg of Aliquat 336 is placed and heated to 70 ° C. Furthermore, a vacuum of 50 mbar is added with vigorous stirring and 510 kg of polysulfide G44 are metered in over the course of 5 hours, the temperature being kept at 70.degree. The reaction mixture is then kept at a temperature between 70 and 90 ° C. for a further 4 hours with further stirring.
• the result is a prepolymer which, after cooling, has a viscosity of 7 Pa.s, an SH group content of 0% and an epoxy content of 49% by weight. The viscosity of the product is unchanged even after 6 months.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Epoxy Resins (AREA)
• Polymers With Sulfur, Phosphorus Or Metals In The Main Chain (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 2003
  • 2003-05-07 DE DE10320543A patent/DE10320543B4/de not_active Expired - Fee Related
• 2004
  • 2004-05-03 AT AT04739125T patent/ATE360655T1/de active
  • 2004-05-03 JP JP2006505353A patent/JP2006525390A/ja active Pending
  • 2004-05-03 CN CNA2004800123453A patent/CN1802398A/zh active Pending
  • 2004-05-03 US US10/555,726 patent/US20060287466A1/en not_active Abandoned
  • 2004-05-03 ES ES04739125T patent/ES2285467T3/es not_active Expired - Lifetime
  • 2004-05-03 EP EP04739125A patent/EP1620484B1/de not_active Expired - Lifetime
  • 2004-05-03 WO PCT/EP2004/004643 patent/WO2004099283A1/de not_active Ceased
  • 2004-05-03 DE DE502004003614T patent/DE502004003614D1/de not_active Expired - Lifetime

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