Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • 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
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/09—Carboxylic acids; Metal salts thereof; Anhydrides thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof

Definitions

• the French patent application FR 2,638,752 A1 also describes a process for functionalizing an ⁇ , ⁇ -dihydroxypolydimethylsiloxane oil, by reaction with a polyalkoxysilane, in the presence of a functionalization catalyst, lithium hydroxide.
• the functionalized oils obtained are useful for the preparation of compositions crosslinkable by condensation in the presence of water, comprising, as condensation catalyst, an organometallic compound based on tin.
• Another object of the invention is to provide a one-component silicone composition for general use, that is to say that its implementation is not accompanied by the emission of products considered toxic, irritating or simply smelly. .
• it is desirable that the implementation of such a silicone composition is particularly easy and fast.
• an object of the invention is to arrive at a satisfactory compromise, both from the point of view of the reactivity of the silicone composition in the presence of moisture, and from the point of view of storage stability or safety. of the silicone composition.
• the composition may include one or more of the following optional components:
• At least one crosslinkable alkoxy-functional polyorganosiloxane resin E a residual amount of a functionalization catalyst F used during the preparation of the oil A and / or the resin E,
• At least one alkoxy-functional silane and / or at least one alkyl-G polysilicate at least one alkoxy-functional silane and / or at least one alkyl-G polysilicate
• the invention relates to a silicone elastomer free of tin, obtained by crosslinking and curing a one-component silicone composition free of tin according to the invention.
• silicone elastomers find their application in many industrial fields. Among these applications include, for example, the preparation of coatings for paints, for antifouling and for antiadhesion food, the formulation of water repellents or thick joints such as cold glues, and mastics used in particular in the construction, household appliances or automobiles, as well as coatings on textile substrates.
• the one-component silicone composition described herein has all the properties of interest and specific to this type of product and has the following advantages: it has a setting kinetics very close to that of a composition comprising a tin-based catalyst;
• the silicone composition is economical and leads to crosslinked elastomers having advantageous mechanical properties.
• the elastomers obtained adhere to many supports.
• oils and the polyorganosiloxane resins will be conventionally described using the following usual notations, used to designate various siloxyl units of formula M, D, T and Q as follows:
• substantially linear is meant a POS oil composed of siloxyl units D further comprising siloxyl units T and / or siloxyl units Q, the number of siloxyl units T and Q being less than or equal to one percent silicon.
• the groups R 1 are identical to or different from each other and each represents a monovalent hydrocarbon group, saturated or unsaturated, substituted or unsubstituted, aliphatic, cyclanic or aromatic, comprising from 1 to 13 carbon atoms,
• the groups R f are identical to or different from each other and each represents a group of formula R 2 O- (CH 2 CH 2 O) b- in which the groups R 2 are identical to or different from each other and each represents a linear alkyl or branched compound comprising 1 to 8 carbon atoms, or a cycloalkyl comprising 3 to 8 carbon atoms, and wherein b is 0 or 1,
• n is sufficient to give the oil POS A a dynamic viscosity at 25 ° C. ranging from 10 3 mPa.s to 10 6 mPa.s, - a is 0 or 1.
• POS A oil comprises a substantially linear silicone oil
• the latter also has the general formula (I) wherein D siloxyl units of formula (R 1 SiO ⁇ 2 Z 2 are replaced by siloxyl units T of formula R 1 SiO 2 and / or siloxyl units Q of formula SiO 4/2, the number of siloxyl units T and
• POS A oil is functionalized according to techniques known to those skilled in the art.
• the functionalized POS A oil corresponds to a stable form, in the absence of moisture, of the one-component silicone composition, or of the one-component silicone mastic, here considered.
• this stable form is that of the composition packaged in hermetically sealed cartridges, which will be opened by the operator during use and which will allow him to apply the composition or putty on all desired media.
• Crosslinking occurs in the presence of water, especially the humidity of the air.
• the POS E resin can also be produced by reacting a precursor POS E resin bearing ⁇ Si-H units on an olefinic alkoxysilane, which resin E "meets the definition given above for E with the difference that part of the groups R 1 are now hydrogen atoms, which will be replaced by R 4 groups during the functionalization reaction.
• An alkoxy functional POS resin E can also be prepared by hydrolyzing condensation of alkyl silicates or an alkyltrialkoxysilane.
• hydrolysis-condensation can be carried out from ethyl silicate or ethyl-triethoxysilane.
• the optional POS E resin and the optional inert POS H, constituting the silicone composition it is important to specify that the groups R 1 are identical or different from each other and are selected from:
• cycloalkyl and halogenocycloalkyl groups having 5 to 13 carbon atoms such as cyclopentyl, cyclohexyl, methylcyclohexyl, propylcyclohexyl, 2,3-difluorocyclo-butyl, 3,4-difluoro-5-methylcycloheptyl groups, alkenyl groups having 2 to 8 carbon atoms such as vinyl, allyl, butene-2-yl,
• polymers A 1 and A "of formulas (F and I") a mixture consisting of several polymers which differ from each other by the value of the viscosity and / or the nature of the groups bonded to the silicon atoms.
• the polymers A 1 and A 'of formula (I' and I ") may include the siloxyl units T of formula R 1 SiO ⁇ and / or siloxyl units Q: SiO 4/2, in the proportion at most 1% (this percentage expressing the number of T and Q units per 100 silicon atoms).
• inert polymers H the same remarks apply to inert polymers H.
• 25 ° C ranging from 10 to 200,000 mPa.s and preferably from 50 to 150,000 mPa.s.
• each R symbol represents an oxygen atom.
• this functionalization catalyst F can advantageously be selected from the following compounds: :
• catalyst F In most cases, from 0.001 to 5 moles of catalyst F are used per 1 mole of silanol groups ( ⁇ Si-OH) supplied, on the one hand, by the precursor (s) A 1 of the ( or of the alkoxylated oil (s) POS A and, on the other hand, by the precursor (s) E 1 of the alkoxylated (s) resin (s) POS E.
• precursor (s) A 1 of the ( or of the alkoxylated oil (s) POS A the precursor (s) E 1 of the alkoxylated (s) resin (s) POS E.
• LiOH 0.005 to 0.5 moles of LiOH are used per 1 mole of silanol groups of A 1 or E 1 .
• the one-component polyorganosiloxane composition comprises, in addition to at least one POS A oil, at least one crosslinking catalyst C in the form of a carboxylic acid and / or a carboxylic anhydride.
• the carboxylic acid C1 comprises at least three carbon atoms, or even better still, at least five carbon atoms.
• at least one carboxylic acid from which the carboxylic anhydride C2 is derived has at least three carbon atoms.
• the crosslinking catalyst C may be chosen, preferably, from: 2-ethylhexanoic acid, octanoic acid, 2-ethylbutyric acid, iso -butyric acid, anhydrides derived from one or two of these carboxylic acids, acetic anhydride and mixtures thereof.
• the silicone composition may further comprise a mineral filler B selected from acidic or neutral mineral fillers, or mixtures thereof.
• the charge B provided is mineral and may consist of products selected from siliceous or non-siliceous materials.
• These powders have an average particle size of generally less than 0.1 .mu.m and a BET surface area greater than 50 m 2 / g, preferably between 100 and 350 m 2 / g.
• Semi-reinforcing siliceous fillers such as amorphous silicas, diatomaceous earths or crushed quartz may also be used.
• non-siliceous mineral materials they can be used as semi-reinforcing mineral filler or stuffing.
• these non-siliceous fillers that may be used alone or in admixture are carbon black, titanium dioxide, aluminum oxide, hydrated alumina, expanded vermiculite, unexpanded vermiculite, calcium carbonate, calcium carbonate and the like. zinc oxide, mica, talc, iron oxide, barium sulfate and slaked lime.
• These fillers have a particle size generally of between 0.001 and 300 ⁇ m and a BET surface area of less than 100 m 2 / g.
• the filler used is fumed silica powder; this silica is in amorphous form when it is intended to obtain translucent mastics.
• these fillers can be surface-modified by treatment with the various organosilicon compounds usually employed for this purpose.
• these organosilicon compounds may be organochlorosilanes, diorganocyclopolysiloxanes, hexaorganodisiloxanes, hexaorganodisilazanes or diorganocyclopolysilazanes (patents FR 1 126 884, FR 1 136 885, FR 1 236 505, GB 1 024 234).
• the treated fillers contain, in most cases, from 3 to 30% of their weight of organosilicic compounds.
• the purpose of introducing the fillers is to impart good mechanical and rheological characteristics to the elastomers resulting from the hardening of the compositions in accordance with the invention. Only one species of feedstock or mixtures of several species can be introduced.
• L represents a ligand ⁇ donor with or without a participation ⁇ , as for example the ligands of the type of those derivatives of acetylacetone, ⁇ -keto esters, malonic esters and acetylimines;
• C represents 0, 1, 2, 3 or 4;
• Ml is a metal selected from titanium, zirconium and mixtures thereof;
• the groups R 6 which are identical or different, each represent a linear or branched C 1 to C 20 alkyl group
• the symbol R 7 with the meaning given above in the formula (V) for R 5 ;
• the symbol L represents a ligand ⁇ donor with or without a participation ⁇ , such as ligands such as those derived from acetylacetone, ⁇ -keto esters, malonic esters and acetylimines;
• M2 is a metal of valence v selected from zinc, aluminum, bismuth, boron and mixtures thereof; E represents a number ranging from zero to v.
• Dl.1 monomers of formula (II) mention may be made of: titanate or ethyl zirconate, titanate or propyl zirconate, titanate or isopropyl zirconate, titanate or zirconate.
• the monomeric metal compounds Dl.1 more particularly preferred are the following products, taken alone or in a mixture: ethyl titanate, propyl titanate, isopropyl titanate, butyl titanate (n-butyl).
• polymers D 1.2 originating from the partial hydrolysis of monomers D 1.1 mention may be made of: polymers D 1.2 originating from the partial hydrolysis of titanates or zirconates of isopropyl, butyl or 2-ethylhexyl .
• the curing catalyst D there may be mentioned: by way of examples of the symbols R 6 and R 7 in the derivatives D2.1 and D2.2 of the formulas (III) and (IV), the propyl groups, isopropyl, butyl (n-butyl), isobutyl, sec-butyl, tert-butyl, hexyl, 2-ethylhexyl, octyl, decyl and dodecyl; and as examples of the symbol L in the D2.2 derivatives of formula (IV), the acetylacetonate ligand.
• organic derivatives D2 may be mentioned: zinc dioctoate, tributyl borate, a bismuth carboxylate and aluminum acetylacetonate.
• the D2 compounds that are more particularly preferred are the following products, taken alone or as a mixture: zinc dioctoate, aluminum acetylacetonate, and aluminum butoxide (linear or branched).
• crosslinking cocatalyst D is chosen from: tetrabutyl titanate, zinc bis (ethyl-2-hexanoate), zinc bis-octoate, aluminum acetyl acetonate, tributyl borate , bismuth carboxylate, tetrapropyl zirconate, and mixtures thereof.
• the one-component silicone compositions according to the present invention may also contain one or more auxiliary agent (s) I such as, for example, per 100 parts by weight of POS A oil: - optionally from 0.1 to 10 parts of an adhesion promoter II,
• VTMS vinyltrimethoxysilane
• the one-component silicone composition comprises:
• auxiliary agent (s) I from 0 to 20 parts by weight of auxiliary agent (s) I, the complement to 100% by weight of oil POS A, with the condition according to which the oil POS A represents at least 45% by weight, preferably at least 55% by weight, of the composition.
• compositions according to the invention harden at room temperature, especially at temperatures between 5 and 35 ° C, in the presence of moisture.
• the hardening (or crosslinking) is carried out from the outside towards the inside of the mass of the composition. Firstly, on the surface, a skin is formed, then the reticulation continues in the mass. The formation time of the skin is faster in the presence of a branched carboxylic acid crosslinking catalyst than in the presence of only an organometallic cocatalyst.
• the subject of the present invention is also (second subject of the invention) a tin-free elastomer capable of adhering to different substrates and obtained by crosslinking and hardening of the single-component silicone composition described above. .
• tin-free one-component silicone compositions according to the present invention are prepared in the absence of moisture by operating in a closed reactor equipped with stirring, in which a vacuum can be evacuated, if necessary, and then optionally replaced air expelled by an anhydrous gas, for example by nitrogen.
• Alkoxy-functional POS E optionally olefinic alkoxysilane (which may be silane G1), and / or G2 alkyl polysilicate, functionalization catalyst F, inert POS H (optional); • then in a step 2, the reaction mixture of step 1 completed by the addition of constituents B (optional), C, I (optional), H (optional) and D (optional); and
• Step 1 A '+ possibly E' + G + F + possibly D + B, with evacuation at this stage of the volatile materials;
• each of the steps implemented in this preparation is conducted at a temperature within the temperature range from 10 to 110 0 C.
• each of the steps is conducted at a temperature ranging from 15 to 90 0 C.
• Step 1 is carried out for a sufficient period of time (for example from 10 seconds to 10 minutes) to carry out a complete functionalization reaction or as close as possible to the maximum degree of functionalization accessible under the operating conditions chosen.
• Step 2 is conducted for a sufficient period of time (for example from 10 seconds to 30 minutes) to arrive at homogeneous compositions.
• Step 3 is generally conducted under reduced pressure between
• a condensation catalyst C and optionally a crosslinking cocatalyst D are added to the slurry obtained according to Preparation 1.
• 0.7 g is added.
• the various catalysts C are 2-ethyl hexanoic acid, octanoic acid, 2-ethyl butyric acid, isobutyric acid and acetic anhydride.
• the various co-catalysts D are butyl titanate, zinc bis (2-ethyl hexanoate).
• Various mixtures of catalyst C and cocatalyst D are also tested:
• pyrogenation silica B (Degussa Aerosil 150) developing a specific surface area of 150 m 2 / g, are incorporated at moderate stirring speed (10 min at 160 rpm) and then more vigorous (4 min at 400 rpm). ) to complete the dispersion in the mixture.
• a viscoelastic fluid is obtained which is rather thick and not very flowing.
• the resulting slurry is degassed under vacuum (less than 50mbar for 6 min at 130rpm) and then transferred to a storage container.
• the different catalysts are:
• titanium tetrakis ethyl-2 hexanolate
• Tyzor TOT of Dupont
• Examples 1 to 6 use the slurry prepared according to Preparation 2.
• Examples 7 and 8 use the slurry prepared according to Preparation 4.
• butyl titanate is substituted with a C8 carboxylic acid, the setting kinetics are faster, especially if the carboxylic acid is branched, as is 2-ethyl hexanoic acid.
• butyl titanate with 2-ethyl hexanoic acid makes it possible to have faster crosslinking kinetics than the two components taken separately.

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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)
• Oil, Petroleum & Natural Gas (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Silicon Polymers (AREA)
• Adhesives Or Adhesive Processes (AREA)

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• 2006
  • 2006-11-09 FR FR0609785A patent/FR2908420A1/fr not_active Withdrawn
• 2007
  • 2007-11-09 JP JP2009535746A patent/JP5261395B2/ja not_active Expired - Fee Related
  • 2007-11-09 US US12/514,243 patent/US20100234510A1/en not_active Abandoned
  • 2007-11-09 CN CN200780046920A patent/CN101743271A/zh active Pending
  • 2007-11-09 WO PCT/EP2007/062165 patent/WO2008055985A1/fr active Application Filing
  • 2007-11-09 CN CN201410140236.5A patent/CN103937262A/zh active Pending
  • 2007-11-09 KR KR1020097011834A patent/KR101135918B1/ko not_active IP Right Cessation
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