EP1727664A1 - Procede de fa onnage faisant appel a une composition de caoutchouc de silicone - Google Patents

Procede de fa onnage faisant appel a une composition de caoutchouc de silicone

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Publication number
EP1727664A1
EP1727664A1 EP05729674A EP05729674A EP1727664A1 EP 1727664 A1 EP1727664 A1 EP 1727664A1 EP 05729674 A EP05729674 A EP 05729674A EP 05729674 A EP05729674 A EP 05729674A EP 1727664 A1 EP1727664 A1 EP 1727664A1
Authority
EP
European Patent Office
Prior art keywords
silicone composition
optionally
component
silicone
alkenyl
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05729674A
Other languages
German (de)
English (en)
Inventor
Wilhelm Weber
Frans Wolffs
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Momentive Performance Materials GmbH
Original Assignee
GE Bayer Silicones GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GE Bayer Silicones GmbH and Co KG filed Critical GE Bayer Silicones GmbH and Co KG
Publication of EP1727664A1 publication Critical patent/EP1727664A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
    • B29C67/246—Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2883/00—Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as mould material

Definitions

  • the invention relates to a process for the production of molded resin articles by a transfer process using a silicone rubber composition which can be applied in a spray process and cured at room temperature to form flexible separating membranes with good mechanical strength, and the use of the silicone rubber composition for producing a separating membrane.
  • the separating membrane according to the invention is used in a molding process for the production of plastic parts from (fiber-reinforced, in particular glass-fiber-reinforced) curable casting resins.
  • the basic principle is an inexpensive rigid mother mold, which is covered or sealed on one side with a flexible membrane, a hardenable casting resin being filled into the space between the mother mold and the membrane and reinforcing elements or reinforcing fibers or fabrics being able to be inserted if necessary.
  • the casting resin for such processes is expediently selected from the casting resins which can be hardened at low temperatures and is filled into the prepared interspace by casting, pressing or sucking in with the aid of pressure or a vacuum.
  • silicone rubbers which are either very pseudoplastic to thixotropic, but which take a long time to cure, or, on the other hand, b) faster crosslinking systems, with which, however, only thin layers could be applied in a coherent layer, because these systems have a short processing time have been selected in a low-viscosity form so that they can be applied quickly.
  • Another embodiment was the addition of solvents to lower the viscosity for quick application.
  • a silicone rubber and a process should be sought which allow a thick-walled membrane to be produced in a few steps at room temperature in a short time.
  • the patent US 2 913 036 and GB 944 955 describe a process for the production of molded parts made of glass fiber reinforced plastic, in which a one-sided rigid form is filled with reinforcing fibers or fabrics and sealed by a flexible, transparent and impervious cover. The space between the mold and the cover is filled with a hardenable resin with the help of an applied vacuum. The bubble-free filling is checked through the transparent cover.
  • the reactive casting resin is cured in the mold, then the transparent cover and the molded part are separated from the rigid mold.
  • the flexible cover can be used several times depending on the material and manufacturing process. The method is often referred to in later patents as "resin transfer molding” (US 4,762,740).
  • US Pat. No. 5,433,165 extends the process for producing a boat hull with the aid of a flexible vacuum bag ' made of transparent ' reinforced 'silicone rubber by vulcanizing a mesh for reinforcement into the silicone layer. To produce the separating bag, the silicone rubber is again diluted with solvent and applied in layers and then hardened.
  • Other patents such as US Pat. No. 4,698,115 or US Pat. No. 4,878,979, teach how to seal flexible covers made from prefabricated silicone rubber parts, for example with silicone adhesive.
  • WO95 / 32849 describes the production of boat hulls with the aid of a vacuum bag with the silicone rubber Dow Corning Tooling Elastomer THT.
  • This "viscous" silicone mixture is applied in several layers to an intermediate layer made of wax.
  • This silicone material is transparent, has a viscosity of 45 Pa.s, is easy to spread out, stable and only hardens after 24 hours after adding the catalyst.
  • No. 5,665,301 uses comparable moisture-curing, transparent 1-component silicone rubbers which are applied in several layers to a thickness of 3 to 4 mm and harden as a thin layer within one hour.
  • a comparable method is taught in US 5,702,663. After exposure to moisture, these systems release fission products from the crosslinking agents used, which is undesirable.
  • US Pat. No. 5,641,525 describes unspecified 2K silicone products for the production of the silicone bag.
  • US Pat. No. 4,822,436 describes how flexible silicone bags can be produced by spraying and brushing with addition-crosslinkable silicone rubbers, by diluting such a rubber with solvents, but without naming further parameters.
  • the problem of limited life due to observed shrinkage is pointed out.
  • EP 874032 describes a sprayable addition-crosslinkable silicone rubber which is to be used as an antifouling coating in a marine environment.
  • the object of the present invention was to provide a silicone composition which can be used in a method for producing a silicone membrane for a “resin transfer molding” method.
  • the method should be suitable for having a sufficiently tear-resistant or thick-walled, transparent separation membrane to produce simple means on site in a short time in order to use this to produce large-area plastic parts using a “resin transfer molding” process.
  • the inventive solution to the problem was achieved by combining a two-component spray application process with a fast-crosslinking silicone rubber, which runs only slightly from vertical surfaces during the short crosslinking time and has high strength after crosslinking.
  • the inventors of the present patent application surprisingly succeeded in fulfilling all of these partially contradicting requirements by using a special application material.
  • the silicone composition used must have a sufficiently low viscosity under the conditions of the spray application, which is so low on the one hand that the composition can be applied by spraying and on the other hand hardens sufficiently quickly that it does not run off obliquely or vertically shaped parts when sprayed on. Furthermore, it has to cure quickly to a transparent silicone rubber at ambient temperature. For this, the transparency must have a level that allows bubbles to be recognized in the casting resin through an approximately 5 mm thick layer.
  • the mechanical strength of the silicone composition which has hardened in a short time must be sufficient to withstand the removal of the silicone cover from the mold or the replica, the hardened casting resin, without damage. This ensures that the separating membrane can be used several times.
  • a method for producing resin moldings by a transfer method is suitable for solving the problem described above, which comprises the following steps: a) providing a mother mold, b) producing a separating membrane, by spraying a carrier material with a hardening silicone composition, c) assembling the mother mold and the separating membrane obtained in step a) to create a cavity between the mother mold and the separating membrane, d) optionally introducing reinforcing materials into the cavity mentioned, e) optionally applying a vacuum to the cavity, f) filling the cavity with a curable resin composition, g) curing the resin composition, h) removing the separating membrane and i) demolding the resin molded body from the mother mold,
  • said sprayable, hardening silicone composition contains:
  • steps a) to i) are known per se, but in the process according to the invention particularities result from the preferred two-component spray application using essentially solvent-free silicone compositions. Since these compositions have very short pot lives, the spray application is preferably carried out by combining at least two subcomponents which are designed in such a way that they do not contain components (A), (B) and (D) at the same time.
  • conventional two-component spray guns such as those used for polyurethane systems such as those from Graco or Hilger and Kern and static mixers, preferably with a length to diameter ratio of approximately> 10, as are known, for example, from Sulzer or Kenics, used.
  • combinations of static mixers, in particular dynamic static mixers and simple spray guns can also be used.
  • the mother mold usually contains molds made of metal or plastic, which at least partly determine the surface or the shape of the replica.
  • the carrier material can be the mother form itself or a complementary form thereof.
  • the carrier material can also consist of metal, plaster, modeling clay or plastic, which may be reinforced.
  • the silicone composition used according to the invention is preferably sprayed onto the carrier material, preferably by means of a two-component spray application, using a separating layer.
  • a separating layer By using the special fast-curing silicone composition, multiple spraying in a short time can produce a relatively thick-walled separating membrane that has sufficient mechanical strength.
  • Preferred layer thicknesses are 1 to 30 mm, preferably 3 to 12 mm. Systems which harden less quickly could thus be processed less well in terms of the speed of the method according to the invention, since the applied materials would run off during the application.
  • step a) (c) assembling the mother mold and the separation membrane obtained in step a) to create a cavity between the mother mold and the separation membrane and (d) optionally introducing reinforcing materials into said cavity.
  • the separating membrane After the separating membrane has hardened, it can be brought together with the mother mold, optionally after coating the mother mold with a separating agent and introducing reinforcing materials, such as fiber mats, nonwovens and other fabrics or reinforcing elements, a cavity being formed between the silicone separating membrane and the mother mold.
  • a separating agent such as fiber mats, nonwovens and other fabrics or reinforcing elements
  • the resulting cavity can expediently be filled particularly well with the casting resin if either a slight excess pressure or a vacuum is applied there, preferably a vacuum is applied in order to enable the cavity to be filled faster and without bubbles.
  • the cavity is then filled with at least one curable resin composition.
  • curable resin composition can be, for example, free-radically started, hardening unsaturated organic compounds, such as monomer compositions, oligomer or polymer compositions, which may contain other customary auxiliaries, fillers, dyes.
  • unsaturated organic compounds such as monomer compositions, oligomer or polymer compositions, which may contain other customary auxiliaries, fillers, dyes.
  • compounds containing styrene, acrylic groups or unsaturated polyesters can be used.
  • addition-crosslinking resin compositions such as, for example, isocyanate-containing, epoxy-containing crosslinkable monomers, oligomers or polymers which contain suitable crosslinking agents, such as polyols, polyamines, etc.
  • curing takes place in a manner known per se. Curing is preferably carried out at 0 ° C. to about 60 ° C., optionally with the aid of trace heating on the molded parts, more preferably at room temperature from 15 ° C. to about 40 ° C. (h) removing the separation membrane.
  • the separation membrane is removed from the mother mold.
  • the separation membrane can then be used for the next shaping process.
  • the resin molded body formed can then be removed from the mother mold and subjected to further processing steps in a manner known per se.
  • the sprayable, hardening silicone composition used according to the invention expediently contains:
  • the alkenyl group-containing polyorganosiloxane (A) has a viscosity range of 0.025 and 40 Pa.s (25 ° C; shear rate gradient D of 1 s "1 ). It can be made from a uniform polymer or mixtures of different polyorganosiloxanes ( A1) or (A1) and (A2) exist.
  • the polyorganosiloxanes (A) are preferably produced by catalytic equilibration or catalyzed polycondensation. The viscosity and alkenyl concentration resulting from this polyreaction after evaporation of the low molecular weight constituents each defines the polyorganosiloxane (A), for example prepared as disclosed in US Pat. No. 6,387,487 columns 3 and 4, which in this form, alone or in the form of mixtures, differ Polymer types are present, with mixtures being preferred.
  • the polyorganosiloxane (A) can be described with the general formula (I): [MaDbTcQdjm (I)
  • the siloxy units M, D, T and Q can be distributed in blocks or randomly in the polymer chain and linked to one another. Within the polysiloxane chain, each siloxane unit can be the same or different.
  • the aforementioned polyorganosiloxanes (A) or their mixtures containing the polyorganosiloxanes (A1) and (A2) preferably have a structure of the general formula (Ia) for the polyorganosiloxanes (A1) which are essentially linear and contain unsaturated substances have organic groups, which is preferably between 0.035 to 1.0 mmol / g.
  • the content of unsaturated organic groups relates to polymethylvinylsiloxanes and is to be adjusted within the specified viscosity limits to siloxy groups with a higher molecular weight.
  • R is an organic group which is preferably selected from: unsubstituted and substituted hydrocarbon radicals, such as n-, iso-, tert.- or -CC 2 alkyl, -C 1 -C 2 alkoxyalkyl, C 5 -C 30 cycloalkyl or C 6 -C 30 aryl, C1-C12 alkyl (C6-C- ⁇ o) aryl, which may optionally each be substituted by one or more O or F atoms and are, for example, ethers.
  • hydrocarbon radicals such as n-, iso-, tert.- or -CC 2 alkyl, -C 1 -C 2 alkoxyalkyl, C 5 -C 30 cycloalkyl or C 6 -C 30 aryl, C1-C12 alkyl (C6-C- ⁇ o) aryl, which may optionally each be substituted by one or more O or F atoms and are, for example, ethers.
  • Suitable monovalent hydrocarbon radicals R include alkyl groups, preferably CH 3 -, CH 3 CH 2 -, (CH 3 ) 2 CH, CsHi7 and C ⁇ oH2i groups, cycloaliphatic groups such as cyclohexylethyl, aryl groups such as phenyl, tolyl, xylyl, Aralkyl groups such as benzyl and 2-phenylethyl groups.
  • Preferred monovalent halogenated hydrocarbon radicals R have the formula C n F 2 n + ⁇ CH 2 CH 2 - where n has a value from 1 to 10, such as, for example, CF3CH2CH2-, C 4 F 9 CH 2 CH 2 - and C 6 F ⁇ 3 CH 2 CH 2 -, preferred radical is the 3,3,3-trifluoropropyl group.
  • a particularly preferred radical R is methyl, phenyl, 1,1, 1-trifluoropropyl.
  • R 1 is an alkenyl-containing organic group which is preferably selected from: Unsubstituted and substituted alkenyl-containing hydrocarbon radicals, such as n-, iso-, tert.- or cyclic C 2 -C 2 -alkenyl, vinyl, allyl, hexenyl, C6-C 3 o-cycloalkenyl, cycloalkenylalkyl, norbomenylethyl, limonenyl, C 8 -C 3 o-alkenylaryl, which are each substituted with one or more O or F atoms, for example ether.
  • Unsubstituted and substituted alkenyl-containing hydrocarbon radicals such as n-, iso-, tert.- or cyclic C 2 -C 2 -alkenyl, vinyl, allyl, hexenyl, C6-C 3 o-cycloalkenyl, cycloalkenylalkyl
  • R 1 are groups such as vinyl, allyl, 5-hexenyl, cyclohexenylethyl, limonenyl, norbomenylethyl, ethylidene norbomyl and styryl, vinyl is particularly preferred.
  • R 2 bridges two siloxy units M, D or T.
  • the divalent units R 2 each bridge 2 siloxane units, for example -DR 2 -D-.
  • R 2 is selected from divalent aliphatic or aromatic n-, iso-, tert.- or cyclic C 1 -C 6 -alkylene, C 6 -C 6 -arylene or -alkylene aryl groups.
  • Suitable divalent hydrocarbon groups R 2 which can bridge siloxy units include all alkylene and dialkylarylene radicals, preferably those such as -CH 2 -, -CH 2 CH 2 -, CH 2 (CH 3 ) CH-, - (CH 2 ) 4, -CH 2 CH (CH 3 ) CH 2 -, - (CH 2 ) 6 - - (CH 2 ) ⁇ - and - (CH 2 ) i8-cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene, xylene. Their proportion does not exceed 30 mol% of all siloxy units. Groups such as alpha, omega-ethylene, alpha, omega-hexylene or alpha, omega-phenylene are preferred.
  • the radical R is preferably in the form of a methyl radical with at least 90 mol% (i.e., 90 to 99 mol% with respect to Si atoms), preferably with at least 95 mol%.
  • the polyorganosiloxanes (A1) contain at least 2 unsaturated organic radicals. They preferably contain 0.035 to 1.0 mmol / g, more preferably 0.05 to 0.8 mmol / g alkenyl groups.
  • the content of unsaturated organic groups relates to polymethylvinylsiloxanes and is to be adjusted within the specified viscosity limits to siloxy groups with a higher molecular weight.
  • the alkenyl groups can either be attached to the chain end of a silioxane molecule or as a group to a silicon atom in the siloxane chain.
  • the alkenyl groups are preferably only present at the chain end of the siloxane molecule. If there are alkenyl groups on silicon atoms of the siloxane chains, their content is preferably less than 0.01 mmol / g.
  • mixtures of different polymers ie there are at least 2 polymers (A1) or at least (A1) and (A2)) with different alkenyl content and / or different chain lengths are advantageously used, the total content of unsaturated groups expediently not exceeding 1.0 mmol / g in component (A).
  • Preferred siloxy units are, for example, alkenyl units, such as dimethylvinylsiloxy, alkyl units, such as trimethylsiloxy, dimethylsiloxy and methylsiloxy units, aryl units, such as phenylsiloxy units, such as triphenylsiloxy-dimethylphenylsiloxy, diphenylsiloxy, phenylmethylvinylsiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxysiloxy.
  • the polyorganosiloxane (A) preferably has a number of siloxy units from 20 to 1000, particularly preferably 100 to 800 (average degree of polymerization P n , which relates to polymethylvinylsiloxanes and must be adapted to siloxy groups with a higher molecular weight within the predetermined viscosity limits).
  • alkenyl content is determined here by 1 H-NMR - see AL Smith (Ed.): The Analytical Chemistry of Silicones, J. Wiley & Sons 1991 Vol. 112 p.356 ff. In Chemical Analysis ed. By JD Winefordner.
  • the alkenyl group content is preferably represented by alkenyldimethylsiloxy units as chain-terminating siloxy units.
  • the alkenyl content can also be defined via the viscosity.
  • the alkenyl content is thus clearly linked to the chain length or the degree of polymerization and thus the viscosity.
  • the polyorganosiloxane (A1) and the mixture of (A1) and (A2) have a viscosity of 0.025 to 40 Pa.s, very particularly preferably 0.2 to 20 Pa.s at 25 ° C.
  • the alkenyl groups R 1 are preferably bonded to terminal silicon units.
  • the C 3 -Ci2 alkenyl group has the olefinic group at the terminal carbon atom, since these alkenyl groups are more reactive.
  • the C 3 -C 2 alkenylsiloxanes claimed here have arisen, for example, from precursors using alpha, omega-halogenoalkenes or alpha, omega-dienes.
  • Another class of preferred polymers (A) which form component (A) together with (A1) are branched polyorganosiloxanes (A2) which are used in combination with other polyorganosiloxanes, such as those defined above, to increase the tear strength or tensile strength, for example can, if no or little reinforcing filler of component (C) is used.
  • These polyorganosiloxanes (A2) such as.
  • the amount of branching units should, however, be limited by the fact that this component should preferably be liquid, low-melting (mp. ⁇ 160 ° C.) or transparent silicone compositions miscible with the other polymers (A) (> 70% transmission at 400 nm and 2 mm layer thickness).
  • the above-mentioned, highly branched polyorganosiloxanes are polymers which contain the aforementioned M, D, T and Q units. They preferably have the general formula (II), (IIa) to (IIb): ⁇ [R ⁇ SiO 3/2] [R 3 O ⁇ / 2] ni ⁇ mi (IIa) ⁇ [SiO4 / 2 ⁇ ] [R 3 O ⁇ 2] ni [R 2 R 1 SiO ⁇ / 2] o, o ⁇ - ⁇ o [ RSiO 3 2] o-so [R2Si0 2/2] o 5 oo ⁇ mi (II b)
  • R 3 is a Ci to C22 organic radical, such as alkyl, aryl or arylalkyl.
  • the molar ratio M: Q can assume values from 0.1 to 4: 1 or M: T from 0.1 to 3: 1, the ratio of D: Q or D: T from 0 to 333: 1, the Units M, D and T which may contain radicals R or R 1 .
  • the branched polyorganosiloxanes (A2) rich in alkenyl groups include, in particular, liquid polyorganosiloxanes, solid resins or liquid resins which are soluble in organic solvents, which preferably consist of trialkylsiloxy (M units) and silicate units (Q units), and preferably vinyldimethylsiloxy units in an amount of at least Contain 0.2 mmol / g. These resins can also have up to a maximum of 10 mol% of alkoxy or OH groups on the Si atoms.
  • the radical R is preferably in the form of a methyl radical with at least 50 mol% (i.e. 50 to 95 mol% with respect to Si atoms), preferably at least 80 mol%.
  • the alkenyl group-rich, preferably vinyl group-rich, polyorganosiloxane (A2) preferably has an alkenyl group content of more than 0.35 mmol / g to 11 mmol / g, which relates to polymethylvinylsiloxanes and, within the specified viscosity limits, to adapt to siloxy groups with a higher molecular weight is.
  • the polyorganosiloxanes (A) can be mixed with one another in any ratio of (A1) to (A2).
  • the ratio (A1): (A2) is preferably more than 2.5: 1.
  • the mixture of polyorganosiloxanes (A1) and (A2) has a viscosity of less than 40 Pa.s at 25 ° C.
  • the invention comprises the polyorganosiloxane (A) essentially linear polyorganosiloxanes (A1) as described above. Branched polyorganosiloxanes (A2) as described above can be added to improve the mechanical properties, especially if the amount of the filler (C) is limited, for example for reasons of viscosity.
  • Another preferred mixture of the polyorganosiloxanes (A) contains two essentially linear alkenyl-terminated polyorganosiloxanes (A1) with different alkenyl, preferably vinyl, contents.
  • This measure is intended on the one hand to prescribe the lowest possible viscosity of the silicone composition, and on the other hand to enable a crosslinking structure with the Si-H compounds of component (B) defined below, which brings about the highest possible mechanical strengths, such as elongation and tear resistance of the crosslinked silicone rubbers , If larger amounts of short-chain alpha-omega-vinyl siloxanes (expediently below a viscosity of 10 Pa.s) are used, this requires larger amounts of alpha, omega-Si-H-siloxanes as so-called chain extenders in order to form suitable crosslinking structures.
  • An alkenyl group-containing, non-mixture polydiorganosiloxane of type (A) is defined in that the weight and number average distribution has arisen from one of the known polymerization reactions, preferably from equilibration or polycondensation with basic or acidic catalysts.
  • Such processes with alkaline or acidic catalysts are disclosed, for example, in US Pat. No. 5,536,803 column 4.
  • the various cyclosiloxanes, linear polyorganosiloxanes, as well as symmetrical 1,3-divinyltetramethyldisiloxane, other longer-chain siloxanes with a trialkylsiloxy end stop or OH end groups can be used for the polymerization reaction with basic or acidic catalysts.
  • the average degree of polymerization P n of the polyorganosiloxane (A), measured as the number average M n by GPC and with polystyrene as the standard, is preferably in the range from P n > 20 to 1000, the more preferred range is Pn 200 to 800.
  • polymers (A) defined in this way in combination with suitable polyhydrogenorganosiloxanes of component (B) described below, allow the production of separating membranes which have sufficiently good rubber mechanical properties, such as elongation at break, tensile strength and tear resistance, and stability of the mechanical properties, and which are applied by spray application, especially two-component spray application can be processed.
  • the polyorganosiloxanes (B) can be described, for example, by the general formula (III), in which the symbols M * stand for M and M H , D * for D and D H and T * for T and T H :
  • the siloxy units can be linked together in blocks or statistically in the polymer chain. Each siloxane unit in the polysiloxane chain can carry identical or different residues.
  • the indices of the formula (III) describe the average degree of polymerization Pn, measured as the number average Mn by GPC, which relate to polyhydrogenmethylsiloxanes and must be adapted to siloxy groups with a higher molecular weight within the specified viscosity limits.
  • the polyorganohydrogensiloxane (B) comprises in particular all liquid, flowable and solid polymer structures of the formula (III) with the degrees of polymerization resulting from the indices given above.
  • the polyorganosiloxanes (B) which are liquid at 25 ° C.
  • the preferred polyorganohydrogensiloxanes (B) are structures which are selected from the group which can be described by the formulas (llla-llle) HR2SiO (R 2 SiO) z (RHSiO) pSiR2H (purple) HMe 2 SiO (Me 2 SiO) 2 (MeHSiO) p SiMe2H (lllb) Me 3 SiO (Me 2 SiO) z (MeHSiO) pSiMe3 (Never) Me 3 SiO (MeHSiO) pSiMe 3 (llld) ⁇ [R 2 YSiO 1/2 ] o-3 [YSiO 3/2] [R 3 O) n2 ⁇ m2 (Hie) ⁇ [SiO 4/2 ⁇ ] [R 3 O ⁇ / 2]
  • a preferred embodiment of the compound classes (Never) and (Ulf) are, for example, monomeric to polymeric compounds which can be described by the formula [(Me 2 HSiO) 4Q] m2.
  • the SiH concentration is preferably in the range from 0.1 to 17 mmol / g, which relates to polyhydrogenmethylsiloxanes and must be adapted to siloxy groups with a higher molecular weight within the specified viscosity limits.
  • the polyorganohydrogensiloxane (B) consists of at least one polyorganohydrogensiloxane (B1) with two Si-H groups per molecule and at least one polyorganohydrogensiloxane of type (B2) with more than two Si-H groups per molecule.
  • component (B) consists of at least two different organohydrogenpolysiloxanes which produce different crosslinking structures in order to give silicone elastomers of high strength in conjunction with low-viscosity sprayable polysiloxanes of component (A). These different organohydrogenpolysiloxanes can essentially be assigned two functions.
  • Bifunctional polyorganohydrogensiloxanes (B1) act as so-called chain extenders
  • the polyorganohydrogensiloxanes (B2) with higher functionality (> 2) act as crosslinkers.
  • the silicone composition used according to the invention preferably contains at least one bifunctional chain extender (B1) and at least one crosslinker (B2).
  • component (B1) in the silicone rubber composition according to the invention examples include chain extenders (B1) such as: HMe 2 SiO- (Me 2 SiO) z SiMe 2 H and Me 3 SiO- (Me 2 SiO) z ⁇ (MeHSiO ) 2 SiMe 3 , [(Me 2 SiO) z ⁇ (MeHSiO) 2 ]
  • chain extenders (B1) such as: HMe 2 SiO- (Me 2 SiO) z SiMe 2 H and Me 3 SiO- (Me 2 SiO) z ⁇ (MeHSiO ) 2 SiMe 3 , [(Me 2 SiO) z ⁇ (MeHSiO) 2 ]
  • the crosslinkers (B2) contain compounds such as: Me 3 SiO- (MeHSiO) p SiMe 3 ,
  • HMe2SiO (Me 2 SiO) z ⁇ (MePhSiO) z2- (MeHSiO) pSiMe 2 H, (MeHSiO) p, (HMe 2 SiO) 4 Si MeSi (OSiMe 2 H) 3 , wherein p, z, z1 and z2 are as defined above.
  • chain extenders and crosslinking agents can be used, for example, as described in US Pat. No. 3,697,473.
  • ⁇ is the total alkenyl content of component (A), preferably the vinyl content is greater than 0.035 mmol / g
  • ⁇ is the chain extender, preferably a polyhydrogenmethlysiloxane
  • (B1) is such that, after subtracting its molar SiH Computed content of the alkenyl content of component A) remains 0.08 to 0.02 mmol / g alkenyl of component (A), ⁇ , the crosslinker (B2) being dimensioned such that the molar ratio of the total amount Si-H (B1) and (B2) to the total amount of Si-alkenyl is 1.1 to 1.5 to 1.
  • this can e.g. by increasing the SiH to alkenyl ratio, an increased amount of catalyst (D) or by increasing the proportion of polyorganosiloxanes (B2) containing HMe2SiOo, 5 units.
  • the chain length of the crosslinking agent as component (B2) which predominantly consist of MeHSiO units, is preferably 3 to 200, particularly preferably 15 to 60 MeHSiO units.
  • the chain length of the chain extenders as component (B1) which mainly consist of Me 2 SiO units and HMe 2 SiO ⁇ / 2 , is preferably 2 to 100, particularly preferably 2 to 60 M ⁇ 2SiO units.
  • the SiH content in the present invention is determined via 1 H-NMR see AL Smith (Ed.): The Analytical Chemistry of Silicones, J. Wiley & Sons 1991 Vol.112 p. 356 ff. In Chemical Analysis ed. By JD Winefordner.
  • the polyorganohydrogensiloxanes (B) can be prepared by processes known per se, for example using an acidic equilibration or condensation, as disclosed, for example, in US Pat. No. 5,536,803.
  • the polyorganohydrogensiloxanes (B) can also be reaction products which have resulted from a hydrosilylation of organohydrogen siloxanes with siloxanes containing alkenyl groups in the presence of the catalysts (D), the resulting SiH content preferably being within the previously defined limits. This results in R 2 - or alkylene group-bridged organohydrogensiloxanes (B).
  • the polyorganohydrogensiloxanes (B) can also be reaction products which result from the condensation of e.g. Organohydrogenalkoxysiloxanes (B) with hydroxy- or alkoxysilanes or siloxanes have emerged, such as e.g. in U.S. 4,082,726 e.g. Columns 5 and 6 are described.
  • the preferred amount of the polyorganohydrogensiloxanes (B) is 0.1 to 200 parts by weight based on 100 parts by weight of component (A).
  • the preferred amount of the polyorganohydrogensiloxanes (B) is chosen such that the molar ratio of the total amount of Si-H to the total amount of Si-alkenyl in component (A) is from 0.5 to 10 to 1, preferably 1.0 to 2.0 to 1, more preferably 1.1 to 1.5 to 1.
  • the ratio of SiH to Si-alkenyl units can be used to influence many properties, such as the rubber-mechanical properties, the rate of crosslinking, the stability and the release properties with respect to the resin molded body.
  • the silicone rubber mixtures used according to the invention furthermore optionally contain one or more, optionally surface-modified fillers
  • fillers include, for example, all finely divided fillers, ie which have particles smaller than 100 ⁇ m, ie preferably consist of such particles.
  • These can be mineral fillers such as silicates, carbonates, nitrides, oxides, carbon blacks or silicas.
  • the fillers are preferably so-called reinforcing silicas, which allow the production of opaque, more transparent elastomers, ie those which improve the rubber-mechanical properties after crosslinking, increase the strength, such as pyrogenic or precipitated silica with BET surfaces between 50 and 400 m 2 / g, which here are preferably hydrophobicized in a special way on the surface.
  • component (C) is used in amounts of 1 to 100 parts by weight, preferably 10 to 70 parts by weight, more preferably 10 to 50 parts by weight, based on 100 parts by weight of component (A) ,
  • the highest transparency is achieved with pyrogenic silicas with a BET surface area of more than 100, preferably more than 200 m 2 / g, more preferably more than 300 m 2 / g, which are dispersed in a suitable manner
  • non-reinforcing extender fillers such as quartz powder, diatomaceous earth, cristobalite powder, mica, aluminum oxides, hydroxides, Ti, Fe, Zn oxides, chalks or carbon blacks with BET can additionally or alternatively be used -Surfaces of 0.2-50 m 2 / g are used. These fillers are available under a variety of trade names such as Sicron, Min-U-Sil, Dicalite Crystallite.
  • inert fillers or extenders with BET Surfaces below 50 m 2 / g should expediently not contain any particles ( ⁇ 0.005% by weight) above 100 ⁇ m for use in the silicone rubbers according to the invention, so that there are no problems during further processing, such as passing through screens or nozzles, during further processing. occur or the mechanical properties of the molded parts produced therefrom are adversely affected.
  • filler (C) means the fillers, including their hydrophobizing agents or dispersing agents or process aids bound to the surface, which influence the interaction of the filler with the polymer, for example the thickening effect.
  • the surface treatment of the fillers is preferably hydrophobic with silanes or siloxanes. It can be carried out, for example, ' in situ' by adding silazanes, such as hexamethyldisilazane and / or divinyltetramethyldisilazane, with the addition of water, and the 'in situ' hydrophobization is preferred.
  • customary filler treatment agents such as vinylalkoxysilanes, for example vinyltrimethoxysilane, other silanes with unsaturated organofunctional groups, such as methacryloxypropyl trialkoxaysilanes, but also polyorganosiloxane diols with chain lengths of 2-50, which carry unsaturated organic radicals in order to provide reactive sites for the crosslinking reaction .
  • silicas which have been rendered hydrophobic beforehand with various silanes are: Aerosil R 972, R 974, R 976 or R 812 or e.g. HDK 2000 or H30 Exemplary trade names for so-called hydrophobic precipitated silicas.
  • 'Wet Silicas' are Sipemat D10 or D15 from Degussa.
  • the silicone composition used according to the invention contains at least one reinforcing filler (C).
  • the thickening behavior of the uncured silicone composition, as well as the transparency and the rubber mechanical properties of the cured silicone separating membrane material can be influenced by the selection of the BET surface and the type of filler.
  • the hydrosilylation catalyst preferably contains at least one metal which is selected from the group consisting of Pt, Pd, Rh, Ni, Ir or Ru.
  • the hydrosilylation catalyst can be used in metallic form, in the form of a complex compound and / or as a salt.
  • the catalysts can be used with or without support materials in a colloidal or powdery state.
  • the amount of component (D) is preferably 0.1-5000 ppm, preferably 0.5-1000 ppm, more preferably 1-500 ppm, particularly preferably 2-100 ppm, calculated as metal, based on the weight of the components (A ) to (C).
  • component (D) is selected, for example, from the Pt catalysts, in particular Pt ° complex Compounds with olefins, particularly preferably with vinylsiloxanes, such as, for example, 1: 1 complexes with 1,3-divinyl-tetra-methyldisiloxane and / or tetravinyltetramethyltetracyclosiloxane.
  • Pt catalysts are exemplified in US 3,715,334 or US 3,419,593 and Lewis, Colborn, Grade, Bryant, Sumpter and Scott in Organometallics, 1995, 14, 2202-2213.
  • the Pt preferably employed ° olefin complexes to set in the presence of 1, 3-di- vinyltetramethyldisiloxane (M Vl 2) by reduction of hexachloroplatinic acid or of other platinum chlorides forth.
  • M Vl 2 1, 3-di- vinyltetramethyldisiloxane
  • these platinum catalysts generally contain free, uncomplexed vinyl siloxanes.
  • These vinyl siloxanes can also have an inhibiting effect on the addition crosslinking. For this reason, a platinum preparation should be used for the fast-curing addition system according to the invention which contains the smallest possible excess of inhibiting vinylsiloxane.
  • the catalyst should contain at least 5% by weight of platinum as metal in M VI 2, preferably more than 10% by weight and particularly preferably at least 18% by weight of platinum, measured as metal. It can be diluted with vinyl-terminated polydimethylsiloxanes for better dosing before use.
  • concentration of platinum in the overall system must preferably be at least 1 ppm, more preferably 15 to 40 ppm Pt calculated as metal.
  • platinum compounds insofar as they allow rapid crosslinking, can be used, such as the photo-activatable Pt catalysts of EP 122008, EP 146307. or US 2003-0199603.
  • the rate of hydrosilylation is determined by the selected catalyst compound, its amount and the type and amount of the additional inhibitor component (E).
  • All solid substances can be selected as supports for the catalysts, provided they do not undesirably inhibit hydrosilylation.
  • the supports can be selected from the group of powdered silicas or gels or organic resins or polymers and can be used in accordance with the desired transparency, preference being given to non-opacifying supports.
  • the rate of the hydrosilylation reaction can be influenced by a number of compounds. This influences the rate of crosslinking, i.e. it is determined at what temperature and in what time the silicone composition or rubber mixture cures or vulcanizes to an elastomeric molded body after the spray application.
  • crosslinking is carried out in a vulkameter according to DIN 53529.
  • t-values such as tio or tgo
  • a time can be determined after which a 10% or 90% increase in torque in relation to the final value of the torque after complete crosslinking takes place at a given temperature Has. So you measure the crosslinking compared to an initial state by changing the torque.
  • the resulting torque also correlates with the elasticity module or the degree of cross-linking of the elastomer under investigation
  • the reaction rate can be reduced, if appropriate, by adding inhibitors, such as vinylsiloxanes, 1,3-divinyltetramethyldisiloxane or tetravinyltetramethyltetracyclosiloxane.
  • inhibitors such as vinylsiloxanes, 1,3-divinyltetramethyldisiloxane or tetravinyltetramethyltetracyclosiloxane.
  • Other known inhibitors can also be used, for example ethynyl-cyclohexanol, 3-methylbutinol or dimethyl maleate.
  • the inhibitors serve to delay the crosslinking reaction for a certain time at room temperature. Thus, at temperatures from 0 to 30 ° C there is both a time-limited inhibition (pot life) and a sufficiently quick and complete cross-linkability (up to the point of non-sticking) at elevated temperature.
  • all inhibitors known for the class of the group of platinum metals can be used, unless a sufficiently long processing time is already achieved by selecting the ligands of the catalyst (D).
  • a preferred embodiment is to use the catalyst without the inhibitor (E).
  • Examples of the large number of known inhibitors are unsaturated organic compounds such as ethylenically unsaturated amides (US 4,337,332); acetylenic compounds (U.S. 3,445,420, U.S. 4,347,346), isocyanates (U.S. 3,882,083); unsaturated siloxanes, (US 3,989,667); unsaturated diesters (U.S. 4,256,870, U.S. 4,476,166 and U.S. 4,562,096), hydroperoxides (U.S. 4,061,609), ketones (U.S. 3,418,731); Sulphoxides, amines, phosphines, phosphites, nitriles (US. 3,344,111), diaziridines (US 4,043,977).
  • unsaturated organic compounds such as ethylenically unsaturated amides (US 4,337,332); acetylenic compounds (U
  • alkynols as described in US 3,445,420. These are e.g. Ethinylcyclohexanol and 3-methylbutinol and the unsaturated carboxylic acid esters of US Pat. No. 4,256,870 and diallyl maleate and dimethyl maleate and the fumarates of US Pat. No. 4,562,096 and US Pat. No. 4,774,111, such as diethyl fumarate, diallyl fumarate or bis- (methoxyisopropyl) maleate.
  • R 5 is selected from the group of C1-C10 alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, etc., and aryl radicals, such as phenyl or benzyl, an alkenyl radical such as vinyl or allyl, W becomes independently from divalent C2-C4 Alkylene residues selected, the index V has the value 0 or 1.
  • the amount of inhibitor component (E) is chosen so that the desired crosslinking time can be set in a suitable manner, ie time and temperature, under the chosen processing conditions, in particular in coordination with the catalyst (D) and the other components.
  • the amount of inhibi- Gate component (E) is preferably 0.0001 to 2% by weight of one or more inhibitors based on the amount of components (A) to (C). If the inhibitor component (E) is used, preferably about 0.001 to 0.5% by weight, particularly preferably 0.05 to 0.2% by weight, of alkynols at metal contents of component (D) of 10 to 100 ppm are metered in.
  • Component (E) is preferably selected from the group consisting of alkynols and vinylsiloxanes.
  • the addition-crosslinking silicone rubber mixtures used according to the invention furthermore optionally contain one or more auxiliaries (F), such as e.g. Plasticizers or release oils, such as polydimethylsiloxane oils, without reactive alkenyl or SiH groups with a viscosity of preferably 0.001-10 Pa.s at 25 ° C.
  • auxiliaries such as e.g. Plasticizers or release oils, such as polydimethylsiloxane oils, without reactive alkenyl or SiH groups with a viscosity of preferably 0.001-10 Pa.s at 25 ° C.
  • additional mold release agents such as fatty acid or fatty alcohol derivatives or extrusion aids such as PTFE pastes can be used.
  • PTFE pastes can be used.
  • Non-opacifying inorganic pigments are expediently used as transparent colorants or color pigments.
  • the stability after exposure to hot air can be increased, for example, using known hot air stabilizers, such as Fe, Ti, Ce compounds in the form of their oxides, inorganic and organic salts and complexes.
  • the amount of auxiliaries (F) is preferably 0 to 15 parts by weight based on 100 parts by weight of components (A) and (B).
  • the silicone composition used according to the invention contains: (A) 100 parts by weight of at least one alkenyl group-containing polyorganosiloxane with a viscosity range of 0.025 and 40 Pa.s (25 ° C; shear rate gradient D of 1 s "1 ), (B) of 0.1 up to 200 parts by weight of at least one polyorganohydrogen siloxane, (C) optionally from 1 to 100 parts by weight of one or more fillers, (D) from 0.5 to 1000 ppm of at least one hydrosilylation catalyst calculated as metal based on the amount of components (A) to (C), (E) optionally from 0.0001 to 2% by weight of one or more inhibitors based on the the amount of components (A) to (C), (F) optionally further auxiliaries.
  • silicone rubber compositions used according to the invention can be obtained by mixing components (A) to (F), the substances advantageously being combined in preferred sequences and preferably at least two partial mixtures being combined and reacted immediately before spraying.
  • the individual components of the silicone rubber mixture are preferably mixed in suitable static mixers, in particular dynamic static mixers, two-component mixing nozzles, as is customary when spraying with reactive lacquers, but also by connecting all possible static mixers and simple spray nozzles.
  • suitable static mixers in particular dynamic static mixers, two-component mixing nozzles, as is customary when spraying with reactive lacquers, but also by connecting all possible static mixers and simple spray nozzles.
  • the dynamic static mixers which support the mixing process with the help of rotating mixing elements, have proven to be the preferred static mixers.
  • the polyorganosiloxanes (A), reinforcing fillers (C) and, if appropriate, the hydrophobicizing agent belonging to (C), preferably hexamethyldisilazane and, if appropriate, divinyltetramethyldisilazane are mixed with water or the silanols prepared therefrom preferably at temperatures from 10 to 100 ° C at least 20 minutes to 120 minutes in a mixing unit suitable for highly viscous materials, such as a kneader, dissolver, planetary mixer or other screw mixer.
  • the excess hydrophobizing agent and water are then evaporated at 120 to 160 ° C. at atmospheric pressure, then optionally in vacuo at a pressure of 100 to 20 mbar.
  • the partial mixtures containing (A) and (C) further components such as components (D), (E) and (F) and, if appropriate, so-called non-reinforcing filler (C) are expediently placed in this basic mixture between 10 up to 120 minutes at 10-160 ° C mixed.
  • Another partial mixture (2) is obtained by adding the hardener (B) to the basic mixture.
  • the components (E) and (F) and, if appropriate, so-called non-reinforcing filler (C) can also advantageously be mixed in between 10 to 60 minutes at 10-160 ° C.
  • the reactive, sprayable silicone composition is obtained by combining the partial mixtures (1) and (2).
  • the addition-crosslinking, sprayable silicone rubber mixtures are produced by producing at least two partial mixtures (1) and (2) which more than one but not all of the components (A) to (F) includes, included.
  • the preferred division into partial mixtures serves for better handling and storage.
  • the reaction of these components with one another can be postponed until immediately before all the components are combined before mixing and spraying.
  • a partial mixture (1) consisting of components (A), (C) and (D) and optionally (F)
  • a partial mixture (2) consisting of at least the components ( B) and optionally (F)
  • partial mixture (2) of components (A), (B), (C), (E) and optionally (F) is mixed.
  • the component (D) can be more or less advantageously kept in each of the components, unless the components (A), (B) reacting with one another are present simultaneously.
  • the inhibitor (E) can be present in any partial mixture; the combination in a partial mixture with (B) is preferred.
  • the silicone composition mentioned can be sprayed above 0 ° C. up to a pressure of at most about 200 bar, more preferably at most 100 bar, more preferably 5-40 bar.
  • the silicone composition is curable above 15 ° C, preferably within 3 hours, i.e. until a tack-free surface is obtained.
  • Non-tacky means that a casting resin that hardens on the surface can be separated.
  • the silicone composition has a tio value of 30 to 400 s at 30 ° C. measured in a vulkameter according to DIN 53 529.
  • the silicone composition is essentially free of solvents.
  • “Essentially free from solvents” in the sense of the invention means that the silicone composition contains less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight of solvent, in particular organic solvent.
  • Organic solvents “includes all carbonaceous solvents except silicon-containing compounds.
  • a silicone composition which can be sprayed, preferably above 0 ° C., up to a pressure of at most 200 bar, more preferably at most 100 bar, even more preferably 5-40 bar, comprising: (A) at least one alkenyl group-containing polyorganosiloxane with
  • the invention further relates to a method for producing a separating membrane by spraying the silicone composition defined above onto a support at least once, and the separating membrane obtainable by this method.
  • “One-time spraying” means that spraying takes place in a single operation and curing without a layer-like structure. This is preferred according to the invention, although it is also possible to repeat this process once or several times after the first layer has hardened.
  • the invention further relates to the use of the separation membrane obtained in a transfer-form process The process allows the production of separation membranes with a wall thickness of 1 to 30 mm, preferably 3 to 12 mm, more preferably 3 to 6 mm.
  • the silicone mixtures cured according to the conditions mentioned in the example should have at least the following rubber mechanical properties: hardness DIN 53505 from 15 to 50 ° Shore A, elongation at break DIN 53504 at least 200% and tensile strength at least 1.5 N / mm 2 .
  • a basic mixture containing silica 1120 g of a linear vinyl-terminated polydimethylsiloxane with a viscosity of 10 Pa.s at 25 ° C. were initially introduced as component (A) with 0.046 mmol / g vinyl and 150 g hexamethyldisilazane as a water repellent (C), 10 g of 1,3-divinyl-tetramethyi-disilazane as a reactive water repellent (C), and 55 g of water were mixed in. Then 560 g of fumed silica with a BET surface area of 300 m 2 / g as component (C) were mixed in stepwise.
  • a dissolver 268 g of the basic mixture previously prepared were mixed with 230 g of a linear vinyl-terminated polydimethylsiloxane (A) with the viscosity of 1 Pa.s at 25 ° C. with a vinyl content of 0.046 mmol / g and 2.0 g of a platinum catalyst Component (D) mixed with 1 wt.% Pt as a Pt ° complex with 1,3-di-vinyltetramethyldisiloxane.
  • This platinum catalyst was prepared in accordance with US Pat. No. 3,715,334 and was diluted with a linear vinyl-terminated poly-dimethylsiloxane with a viscosity of 1 Pa.s at 25 ° C.
  • a rheometer MDR 2000 from Alpha Technologies was used at a chamber temperature of 30 ° C, in which the partial mixtures (1) and (2) were filled into a two-chamber cartridge at approx. 30 ° C
  • a two-chamber dosing gun With the help of a two-chamber dosing gun, a short static mixer was sprayed directly into the measuring chamber of the rheometer, which was kept at 30 ° C, and the measurement started immediately (see Tab. 1). The measurement time was 30 minutes.
  • Example 2 To determine the mechanical properties, 200 mg of the partial mixture (1) were mixed with 40 mg of the inhibitor dimethyl maleate and then mixed with 200 g of the partial mixture (2). The mixture was deaerated in vacuo at 20 mbar, poured into a test plate mold (2 mm thick test plates) and cured under pressure (60 bar) for 10 minutes at 170 ° C (see Table 2). Tab. 2 Rubber mechanical properties of Example 2
  • Example 3 The partial mixture (1) and (2) of Example 1 were fed in a temperature-controlled two-component system with the aid of drum pumps to a continuously variable gear pump, which pumps the partial mixtures into a static-dynamic mixer at a pressure of up to 150 bar via hose lines dosed. This was connected to a spray attachment over a short distance. The order quantity could be controlled by changing the pressure.
  • the reactive mixture of the partial mixtures (1) and (2) was sprayed onto a rigid mother mold made of polyurethane in order to produce the separating membrane according to the invention. The application was carried out at a temperature of 24 ° C in one operation to layer thicknesses between 5 and 15 mm. The sprayed mass did not run off the vertical parts of the mold and hardened quickly. It took 15 minutes to apply. The working pressure at the spray nozzle was approximately 15 bar. The silicone separation membrane could be removed from the rigid form in less than 30 minutes.
  • This separating membrane was used as an elastic silicone cover for the "Resin Transfer Molding" process.
  • a mold consisting of a rigid mother mold made of polyurethane (outer mold) and the flexible separating membrane made of silicone elastomer was formed.
  • the separating membrane was already in the process of being networked with suitable suction openings
  • the mother form contained a Release agent.
  • the intermediate space contained a glass fiber braid, was sealed to maintain the vacuum and filled with an unsaturated polyester resin incl. Hardener by applying a vacuum. Then the polyester resin was sucked in, soaking the glass fiber with resin. After the polyester had cured, the silicone cover could be removed and used again.

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Abstract

L'invention concerne un procédé pour produire une membrane en silicone pour un procédé de moulage par transfert de résine, procédé au cours duquel une composition de silicone pulvérisable exempte de solvant, qui durcit en couches épaisses pour former une membrane de séparation transparente, souple et à parois épaisses est utilisée. Cette membrane de séparation est utilisée dans un procédé de façonnage pour produire des pièces en plastique à partir de résines de coulée durcissables renforcées par des fibres.
EP05729674A 2004-03-18 2005-03-17 Procede de fa onnage faisant appel a une composition de caoutchouc de silicone Withdrawn EP1727664A1 (fr)

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DE200410013742 DE102004013742A1 (de) 2004-03-18 2004-03-18 Formgebungsprozess unter Verwendung einer Silikonkautschuk-Zusammensetzung
PCT/EP2005/051257 WO2005090057A1 (fr) 2004-03-18 2005-03-17 Procede de façonnage faisant appel a une composition de caoutchouc de silicone

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EP1727664A1 true EP1727664A1 (fr) 2006-12-06

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WO2008103485A1 (fr) 2007-02-23 2008-08-28 Rydin Richard W Procédé de fabrication et d'utilisation d'un sac sous vide en caoutchouc naturel formé par pulvérisation
US8672665B2 (en) 2007-05-18 2014-03-18 Arjr Group, Llc Vacuum bag with integral fluid transfer conduits and seals for resin transfer and other processes

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US4822436A (en) * 1986-03-07 1989-04-18 Northrop Corporation Apparatus for debulking and autoclaving laminates of complex shapes
US5624512A (en) * 1992-10-02 1997-04-29 United Technologies Corporation Method of curing composite articles using conformable vacuum bags
US5439635A (en) * 1993-02-18 1995-08-08 Scrimp Systems, Llc Unitary vacuum bag for forming fiber reinforced composite articles and process for making same
US5326521A (en) * 1993-05-26 1994-07-05 East Douglas A Method for preparing silicone mold tooling
US5433165A (en) * 1994-03-30 1995-07-18 Outboard Marine Corporation Method of manufacturing a boat hull
US5958325A (en) * 1995-06-07 1999-09-28 Tpi Technology, Inc. Large composite structures and a method for production of large composite structures incorporating a resin distribution network
US5807593A (en) * 1996-07-10 1998-09-15 The Boeing Company Vacuum bag not requiring disposable breathers
US5906893A (en) * 1997-04-25 1999-05-25 General Electric Company Sprayable, addition curable silicone foul release coatings and articles coated therewith
NO317413B1 (no) * 1999-05-21 2004-10-25 Hiform As Fremgangsmate for fremstilling av fiberarmerte termoplastkomposittmaterialemner
US6723273B2 (en) * 2002-09-11 2004-04-20 Keith Johnson Curable liquid sealant used as vacuum bag in composite manufacturing

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