Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/28—Oxygen or compounds releasing free oxygen
  • C08F4/32—Organic compounds
  • C08F4/38—Mixtures of peroxy-compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/06—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent
  • C08J9/10—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent developing nitrogen, the blowing agent being a compound containing a nitrogen-to-nitrogen bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
  • C08J9/142—Compounds containing oxygen but no halogen atom
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2203/00—Foams characterized by the expanding agent
  • C08J2203/12—Organic compounds only containing carbon, hydrogen and oxygen atoms, e.g. ketone or alcohol
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
  • C08J2333/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2333/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
  • C08J2333/24—Homopolymers or copolymers of amides or imides

Definitions

• the invention relates to a process for the preparation of poly (meth) acrylimidschaumstoffen and blocks, plates and the like from such poly (meth) acrylimidschaumstoffen and occurring as intermediates molded article from the copolymer of (meth) acrylic acid and
• Copolymerization prepared a precursor, which is already obtained in a corresponding plate form. Subsequently, the copolymer is cyclized to imide. An im
• DE 1 817 156 already describes a process according to which foamable plastics are produced in sheet form by polymerizing mixtures of methacrylonitrile and methacrylic acid between two glass plates which are sealed with a flexible cord.
• the starting mixture is already a blowing agent, namely
• Formamide or monoalkylformamide added.
• free radical generators are present, for example as
• the polymerization takes place at temperatures of
• Azo-bis-isobutyronitrile for example, is used as the free-radical initiator, and 0.1-10% by weight of electrically conductive particles are added to the mixture to be polymerized. Also in this method, the above problems arise.
• EP 1 175 458 describes the production of thick blocks in isothermal mode. This is achieved by the use of at least 4 different initiators. However, this document is limited to methacrylonitrile and not applicable to acrylonitrile as a building block. Furthermore, it does not affect the reduction of the residual monomer content
• the described initiator which is active at the highest temperature has a half-life of 1 h at 115 ° C. to 125 ° C. and acts primarily during tempering, but not during foaming.
• Foams based on methacrylic acid and acrylonitrile are described, for example, in CN 100420702C. These PI foams do not have a greatly increased content
• Half life of 1 h at 60 ° C to 100 ° C or 100 ° C to 140 ° C additionally be used. However, this method is not transferable to foaming or acidic systems.
• the annealing at least partially at a temperature between 80 and 120 ° C and the foaming at a temperature between 120 and 200 ° C is performed.
• the tempering is usually carried out at a steady or increasing in stages temperature, wherein at least the final temperature between 80 and 120 ° C.
• the method according to the invention is characterized in that the polymerization mixture contains at least three initiators.
• the decomposition temperatures of the three initiators are such that a half-life of one hour of the first initiator below 80 ° C, preferably in a Range of 40 to 80 ° C and more preferably in a range of 50 to 75 ° C, the second initiator between 80 and 120 ° C, preferably in a range of 85 to 100 ° C, and the third initiator above 120 ° C. .
• the decomposition temperatures of the three initiators are preferably at least 10 ° C., preferably at least 15 ° C., apart.
• the mixture is composed of three
• Initiators based on the total composition together as follows: 0.5 to 1.5% by weight of a first initiator having a half-life of one hour in the range of 50 to 75 ° C,
• the monomer composition and the poly (meth) acrylimide foam prepared therefrom additionally contain 8 to 18% by weight of dimethyl propyl phosphonate
• a first embodiment is characterized in that exactly three initiators are used. This particularly relates to an embodiment in which a
• PMI foams Polymethacrylimid foams
• polyacrylimide foams are produced by copolymerization of a mixture of methacrylic acid and acrylonitrile and optionally other copolymerizable monomers.
• at least four, preferably four or five, initiators are particularly preferably used for different temperature ranges.
• the fourth and optionally the fifth initiator may each have a decomposition temperature in the range of one of the four initiators described above and be activated with this each in the same process step.
• this mixture of four initiators based on the total composition is composed of 0.5 to 1.5% by weight of a first initiator having a half-life of one hour in the range of 50 to 75 ° C, 0.01 to 0.2% by weight. a second initiator having a half-life of one hour in the range of 85 to 100 ° C, 0.01 to 0.2% by weight of a third initiator having a half-life of one hour in the range of 120 to 130 ° C and 0.01 to 0 2 % By weight of a fourth initiator having a half-life of one hour in the range of 130 to 180 ° C.
• the amount of initiator mixture used may be in
• the polymerization temperature can also be influenced by the amount of initiators used.
• the amounts used in the invention are given in parts by weight of initiator per 100 parts by weight of monomers.
• Methacrylic acid, styrene, maleic acid or itaconic acid or their anhydrides or vinylpyrrolidone should not exceed 30% by weight, preferably not more than 10% by weight, of the two main constituents
• crosslinking monomers e.g. Allyl acrylate
• the amounts should preferably be at most 0.05 to 2.0% by weight.
• the mixture for the copolymerization further contains
• Propellants that either decompose or evaporate at temperatures of about 150 to 250 ° C while a
• blowing agents are the nitrogen-containing compounds urea, monomethyl or N, N'-dimethylurea, formamide or monomethylformamide.
• nitrogen-free propellants are formic acid, water or monohydric aliphatic alcohols, in particular those having three to eight
• the blowing agents are generally used in amounts of from 0.5 to 8% by weight, based on the monomers used.
• the polymerization suitably takes place in block form.
• the monomer mixture is between two glass plates, which are each sealed at the edge and form a kind of flat chamber.
• This flat chamber is surrounded by a water bath that is on the desired
• Polymerization temperature is adjusted.
• the polymerization can be carried out largely or over a wide range under isothermal conditions, i. at constant water bath temperature. In many cases, it is possible to keep the water bath temperature constant from the beginning to the end of the polymerization. Possibly. However, the water bath temperature can also initially be kept constant for a long time and increased after a certain time to perform part of the polymerization at a higher temperature. Also in this next, carried out at a higher temperature polymerization, the
• the chosen water bath temperature depends on the thickness of the polymerization chamber and the formulation used in the polymerization. That's it in general
• the appropriate temperature for formulation and thickness can each be optimized by simple preliminary tests.
• the temperature is adjusted to the thickness of the chamber and the formulation within the limits listed above so that the heat released during the polymerization can be dissipated to a sufficient extent without it during the
• Temperature control starting at 38 ° C, preferably starting at the polymerization temperature, can be adjusted. 10 to 1000 hours are generally sufficient for this final polymerization in a tempering cabinet.
• the block After completion of the polymerization, the block is heated to a temperature of about 120 to 250 ° C, preferably from 120 to 200 ° C, at which temperature the cyclization to the imide structure and foaming take place.
• times of 3 to 5 hours are sufficient for this thermal aftertreatment.
• the imidization within one and the foaming may be completed within two additional hours.
• the case obtained blocks are characterized by a homogeneous uniform structure.
• foam blocks produced therefrom can be made up as such, wherein the
• a particular aspect of the present invention is that initiators from different temperature ranges
• Acrylic foams are transferable and the technical
• initiators customary per se can be used, as are used for radical formation in free-radically initiated polymerization.
• organic peroxides such as dicumyl peroxide
• Peroxydicarbonates such as diisopropyl peroxydicarbonate, peresters such as tert-butyl peroxy-2-ethylhexanoate and the like.
• Other types of compounds which can form radicals are also suitable within the scope of the invention. These include in particular azo compounds such as azo-bis (isobutyronitrile) and azo-bis (2,4-dimethylvaleronitrile).
• initiator mixtures whose components are selected from the following initiators: azo-bis (isobutyronitrile), t-butyl peroctoate, t-butylper-2-ethylhexanoate, t-butylperbenzoate, t-butylperpivalate, azo-bis - (2,4-dimethylvaleronitrile), t-butylperneodecanoate, di-t-butyl peroxide, dibenzoyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate,
• Cumylperoxineodecanoate and 1,4-di- (2-neodecanoylperoxyisopropyl) benzene The half-life of the initiators that can be used is generally already specified by the manufacturer. It is easy to determine analytically, with benzene as the solvent generally being found to be suitable. The determination is generally carried out with a 0.1 molar solution
• foamed blocks or plates or
• foam sheets or foam blocks are very valuable materials and can be used as components in particular
• Aircraft, vehicle, rail, spacecraft, aircraft or ship construction are used.
• the polymer blocks produced according to the invention are characterized by a very uniform structure and a very low residual monomer content. They can be stored for any length of time and, if necessary, converted from case to case into foam sheets by appropriate heating.
• Comparative Example 1 4.2 parts of isopropanol and 4.7 parts of formamide were added as blowing agent to a mixture of 57 parts of methacrylic acid and 43 parts of acrylonitrile. Furthermore, the mixture 0.103 parts Cumylperneodecanoat, 0.04 parts tert-butyl perpivalate, 0.04 parts tert. Butyl per-2-ethyl hexanoate, 50 ppm p-benzoquinone, 0.22 part zinc oxide and 0.150 part release agent (PAT 1037).
• Residual content of unreacted acrylonitrile to 9810 ppm determined.
• Example 1 In this comparative example, three initiators having decomposition temperatures based on a half-life of less than 100 ° C. were not used according to the invention. The high residual content of acrylonitrile shows that such a process is unsuitable for solving the problems underlying this invention.
• Example 1
• Residual content of unreacted acrylonitrile to 5850 ppm determined.
• the subsequent foaming in the hot air process was 2 hours at 185 ° C.
• the resulting foam had a
• the subsequent foaming in the hot air process was 2 hours at 185 ° C.
• the resulting foam had a
• Residual content of unreacted methacrylonitrile to 1660 ppm determined.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

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• 2011
  • 2011-01-20 DE DE102011002905A patent/DE102011002905A1/de not_active Withdrawn
  • 2011-12-13 US US13/996,552 patent/US20130281561A1/en not_active Abandoned
  • 2011-12-13 CN CN2011800653017A patent/CN103328550A/zh active Pending
  • 2011-12-13 WO PCT/EP2011/072540 patent/WO2012097921A2/fr active Application Filing
  • 2011-12-13 EP EP11793820.9A patent/EP2665766A2/fr not_active Withdrawn
• 2012
  • 2012-01-17 TW TW101101773A patent/TW201245250A/zh unknown

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