MXPA99011326A - Paintable organopolysiloxane mold release compositions and processes for their use - Google Patents

Abstract

Silicone mold release compositions which are a stableblend of hydrophobic-modified organopolysiloxane and an aminoorgano- or mercaptoorgano-functional organopolysiloxane, or a solution in organic solvent of a stable or unstable blend, provide exceptional mold release properties while retaining paintability of molded parts.

Description

COMPOSITIONS OF PINTABLE DESMOLDEO. BASED ON ORGANOPOLISILOXANOS, AND PROCEDURE FOR USE TECHNICAL FIELD The present invention relates to mold release compositions based on organopolysiloxanes which have improved paintability.

TECHNICAL BACKGROUND Release compositions have been used for a long time to facilitate the detachment of molded polymer parts from molds. Particularly in the case of parts having complex shapes or deep sections, and more particularly in the case of polymers that exhibit aggressive adhesion to the mold surface, it would not be possible to produce parts without effective demolding. There is a wide variety of release agents. The first known release agents used natural and synthetic waxes. Frequently, the molds had to be polished manually or mechanically to obtain a maximum detachment. Said demolding agents are not practical for modern high speed production regimes. However, an advantage of such mold release agents is that they are often paintable without rubbing or cleaning, and can also be easily removed. Sometimes solutions and aqueous dispersions of soaps are used as demolding agents. However, soaps are not very effective, and can not be used with moisture-sensitive molding compositions such as polyurethane RIM (internal molding reactive compositions), unless they are allowed to dry thoroughly. If they are still wet, surface defects and local foaming may occur in the polyurethane RIMs. Polyurethane RIMs have been especially problematic due to their natural tendency to adhere to the molds. A considerable advance in the technology of the RIM consisted in the introduction of internal demolding agents based on zinc stearate in conjunction with fatty substances such as fatty esters and epoxidized natural oils. These release agents are incorporated into the reactive composition before molding. Unfortunately, in order to provide multiple and coherent detachments, said internal mold release agents must be used at high levels. For pieces that must be painted, these high levels of use impair the ability to paint. However, the fact of decreasing the amount of the release agent increases the difficulty of detachment. Therefore, said systems generally employ external demolding agents in conjunction with internal demolding agents.

Organopolysiloxanes such as poly (dimethylsiloxane) fluids terminated in trimethylsiloxy have proven to be effective mold release agents, and when used in conjunction with organopolysiloxanes having aminoalkyl and thioalkyl functions, as described in US Pat. . 4,251,277 and 3,883,628, provide an extraordinary detachment. Said organopolysiloxane fluids may be applied without mixing, in solution in an organic solvent, or in the form of an aqueous emulsion. For pigmented molded parts such as ski boots, in-line roller skates, and the like, said mold release agents are exemplary. Unfortunately, poly (dimethylsiloxane) fluids have a bad reputation for destroying the paintability of castings, even after extensive rubbing and washing operations. Current defects of the paints include an irregular covering, sometimes to the extent of leaving large bare areas, rough surfaces known as "orange peel", fades, shifts and, particularly, superficial microcracks known as "fish eyes". The effects of such fluids on paintability are so severe that some manufacturing facilities prohibit all products containing poly (dimethylsiloxanes), including solid silicones such as a gasket material. Suppliers of O-ring seals and other products must often certify that their products do not contain poly (dimethylsiloxanes).

Efforts to retain the advantages of poly (dimethylsiloxanes) as release agents while retaining paintability have only partially succeeded. Modification of these siloxanes by replacement of a portion of the methyl groups by relatively hydrophobic hydrocarbyl groups, eg C4-30 alkyl groups, phenyl groups and, in particular, by a-methyl phenylethyl groups, has resulted in of demolding the type of siloxanes which are sometimes paintable immediately after they have been demoulded and without any additional subsequent treatment such as rubbing or washing, and which rather uniformly show good paintability after said subsequent treatment. An example of such fluids is the Wacker TN available from Wacker Silicones, Adrián, Michigan. Similar mold release agents are described in Japanese Patent Document Kokai JP 09012886 A2. Unfortunately, although they exhibit improved drawability, the aforementioned modified siloxanes are not even nearly as effective in their demoulding properties as the unmixed poly (dimethylsiloxanes) containing an organopolysiloxane with amino-organic or thiol-organic functions. This is the case particularly when deep sections and / or polymeric systems that aggressively adhere are involved. It would be desirable to provide a mold release composition which would be comparable in its ability to be demolded with poly (dimethylsiloxanes) containing organopolysiloxane (s) with amino-organic or thiol-organic functions, while also being paintable.

DESCRIPTION OF THE INVENTION The present invention relates to mixtures of organopolysiloxanes based on fluids of hydrophobically modified poly (dimethylsiloxanes) and organopolysiloxanes with amino-organic and / or mercapto-organic functions. These compositions provide both excellent release characteristics and paintability when prepared as stable compositions, as described below. Surprisingly, unstable compositions that are not suitable as paintable release agents by themselves become very effective when dissolved in an organic solvent.

BEST WAY TO CARRY OUT THE INVENTION The release compositions of the present invention contain, as active ingredients, an organopolysiloxane with organic functions and a hydrophobically modified polyorganosiloxane. The compositions can be applied without mixing, from a solution or as a dispersion. Unmixed products should have stability, as defined in this specification. The compositions may also include additional organopolysiloxanes, silanes, rheology control agents, surfactants, etc., but most preferably are devoid of poly (dimethylsiloxane) fluids, including silanol-terminated polydimethyl fluids, such as ,? - dihydroxyl-poly (dimethylsiloxanes); and poly (dimethylsiloxanes) having terminal or pendant alkyloxy or acetoxy hydrolyzable groups. Alkoxy groups or other groups which are not hydrolysable, or which hydrolyze only slowly, may be acceptable for use as water-repellent groups, if these groups contain an appropriate hydrophobic element. The hydrophobically modified polyorganosiloxane can be branched or linear, and contains moieties corresponding to: RaRlSiOu2 (I) RaRSiOv (H) KSiOvl (III) SiO 4/2 (IV) wherein R is a lower alkyl or alkylene, optionally interrupted by an ether oxygen or a thioether sulfur, such as methyl, n-propyl, i-propyl, n-butyl, vinyl, methoxy-methyl, methoxy-ethyl, ethoxy -methyl, ethoxy-ethyl, methoxypropyl and 2-thio-butyl.

R preferably contains 4 carbon atoms or less, more preferably 3 carbon atoms or less, and in particular 1 or 2 carbon atoms. R1 is a hydrophobic C-C3o group that optionally contains no more than one ether oxygen or one thioether sulfur when the carbon content is less than C10, and in general not more than two atoms of oxygen of ether or of sulfur of thioether for groups Cío-C30, in any case an insufficient quantity of atoms of -O- and / or -S- interdispersed to annul the hydrophobicity of the hydrophobic group R1 The hydrophobic nature of the R1 groups containing inter-dispersed -O- and -S- atoms can be determined by evaluating the paintability of the molded parts that have been prepared using a release agent containing a polysiloxane with organic functions and the modified candidate polysiloxane hydrophobically, which contains -O- or -S-. Preferred examples of R1 are alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, alkylaryl and arylalkyl groups C4.3o, preferably C6-2o- Non-limiting examples are 2-ethylhexyl, n-octyl, n-decyl, n-dodecyl, n-octadecyl, lauryl, stearyl, phenyl, tolyl, benzyl, phenylethyl, norbornenyl and particularly a-methyl-phenylethyl. Also particularly suitable are alkylated phenyl and naphthyl groups, for example 4-nonyl-phenyl, 4-nonyl-phenylethyl, and 4-nonyl-2-methyl-phenylethyl, and the like, and cycloalkyl and cycloalkenyl groups substituted with alkyl, such as 4-ethyl-cyclohexyl, 4-nonyl-cyclohexyl, 4-methyl-cyclohexyl, 2-cyclohexyl-hexyl, and the like.

The various groups R and R1 may be substituted or unsubstituted. Examples of suitable substituents are the alkoxy, cyano and halo substituents, preferably cyano and chloro. Also suitable are the trifluoromethyl group and other haloalkyl groups. It is possible that some of the R and / or R1 groups may be replaced by hydroxy, halo, hydrido or alkoxy groups, but these are preferably absent, the amounts preferably being not greater than those which are unavoidable in the preparation of the hydrophobically modified organopolysiloxane. . Most preferably, R is methyl and R 1 is phenyl, benzyl, phenylethyl or a-methyl-phenyl-ethyl. Other preferred R1 groups are -R2-R3 in which R2 is an alkylene, cycloalkylene or phenylene di-radical, and R3 is phenyl, naphthyl, tolyl, and the like. Essentially, R1 can be any hydrophobic group that improves paintability. In formulas I, II and III, a, b and c can be 0, 1, 2 or 3, and the sum of a + b is such that it is 3 for formula I, 2 for formula 11, and 1 for the formula lll. Preferably, the hydrophobically modified organosiloxanes contain no more than 10 mole percent of units of the formula IV (Q units), more preferably no more than 5 mole percent, and most preferably only unavoidable amounts of Q units. The organopolysiloxanes hydrophobically modified also preferably contain no more than 20 mole percent of the units of formulas III (units T), more preferably no more than 10 mole percent, still more preferably no more than 5 mole percent, and most preferably preferably 2 mole percent or less, for example without T units or only those which are unavoidable. More preferably, the hydrophobically modified organopolysiloxanes correspond to the formula wherein R2 is R or R1, and R2 is preferably methyl; or R2 is R3 or R4; wherein R3 is preferably an aryl or arylalkyl group such as phenyl, tolyl, benzyl, phenylethyl and in particular a-methyl-phenylethyl; and wherein R 4 is preferably a C 8 -C 20 alkyl group, more preferably a C 1 -C 0 alkyl group. The two terminal methyl groups of formula V can also be replaced by R 2, but this is not preferred. Most preferably, R2 is methyl. Most preferably, the hydrophobically modified organopolysiloxanes are those corresponding to In the above formulas, x, y and z are positive integers, preferably such that z is an integer from 3 to 30, more preferably from 4 to 24, and most preferably from 5 to 18, and x and y are integers from 0 to about 1000, more preferably from 3 to 250, and most preferably from 4 to 60, with the proviso that the sum of x + y must be at least 5, and the molecules must have, on average, at least 5 repeating siloxy units, preferably from 10 to 100 such repeating units, and most preferably from 15 to 50 such repeating units, corresponding to a number average molecular weights of from greater than approximately 600 Da to approximately 600,000 Da or greater, and viscosities of from about 10 cSt to about 20,000 cSt, preferably 50 cSt to about 5000 cSt. The hydrophobically modified organopolysiloxanes can be prepared by known methods, for example by hydrosilylation of 2-methyl-styrene and similar compounds, and of terminal or non-terminal alkenes, and mixtures thereof, with organopolysiloxanes containing silicon-bonded hydrogen (SiH), for example organopolysiloxanes having terminal methyl-silane or dimethylsilane groups, or internal methylhydrogen-siloxy groups, in the presence of conventional hydrosilylation catalysts, in particular catalysts with platinum.

The hydrophobically modified organopolysiloxanes can also be prepared by condensation reactions, for example by condensation of organopolysiloxanes having SiH functions with chlorinated hydrocarbons, generating HCl, or, when appropriate, by direct synthesis. The molecular weight and the viscosity can be adjusted by equilibration and condensation reactions known in the art. Preferably, poly (dimethylsiloxanes) that do not contain hydrophobing groups are absent during equilibration. Organopolysiloxanes with organic functions, which are a necessary component of the present invention, contain an amino-organic or mercapto-organic functionality. In general, and in particular due to their mode of preparation, organopolysiloxanes with organic functions may also contain a hydrolyzable alkoxy functionality. The amino organic and mercapto organic groups generally correspond to the formulas R6HN-X- and HS-X- wherein X is a linker group attached to Si, preferably an alkylene group, which optionally contains heteroatoms or heteroatom-containing groups such as as, but not limited to, or -NH-, -NR-, -C-, -CO, OCO, -OS-, -OSO- 0 OSS II II II II -OC- H-, -NH-C- H-, -C-, - CS, and others similar, and R6 is as defined below. The linker group X may also be a phenylene, cycloalkylene, arylalkyl, alkylaryl, or other similar group, and generally contains from 1 to about 30 carbon atoms, preferably from 2 to 10 carbon atoms, and most preferably from 3 to 5 carbon atoms. Preferred aminoalkyl groups are those corresponding to the formula VII -R5 - [(NR6) -R7] tNR8R9 (VII) wherein R5 and R7 are divalent hydrocarbyl groups, and R6, R8 and R9 are hydrogen or substituted or unsubstituted C1-30 hydrocarbyl groups, more preferably C1-C18 hydrocarbyl groups, which optionally contain heteroatoms or interdispersed heteroatom-containing groups, and R5 is preferably a divalent C1 to C8 hydrocarbyl radical, R6 is preferably a hydrogen atom or an unsubstituted C1 to C2 alkyl or aryl radical, in which the alkyl and aryl with respect to R6 may also include arylalkyl radicals and alkylaryl, respectively, R 7 is preferably a divalent C 1 to C 8 hydrocarbyl radical, R is preferably a hydrogen atom or an unsubstituted C 1 -C 8 alkyl or aryl radical, wherein the alkyl and aryl with respect to R 8 they may also include arylalkyl and alkylaryl radicals, respectively, R9 is preferably a hydrogen atom or an unsubstituted CrC18 alkyl or aryl radical, wherein alkyl and aryl are With respect to R9 they can also include arylalkyl and alkylaryl radicals, respectively, and t is preferably an integer from 0 to 6. Examples of divalent Ci to C? 8 hydrocarbyl radicals, represented by R5 and R7, are the methylene, ethylene, n-propylene, sopropylene, n-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, neopentylene and tert-pentylene; hexylene radicals such as the n-hexylene radical; heptylene radicals such as the n-heptylene radical; octylene radicals such as the n-octylene radical and isooctylene radicals such as the 2,2,4-trimethyl-pentylene radical; nonylene radicals such as the n-nonylene radical; decylene radicals such as the n-decylene radical; dodecylene radicals such as the n-dodecylene radical; and octadecylene radicals such as the n-octadecylene radical. Examples of C 1 to C 8 alkyl radicals R 6, R 8 and R 9 are methyl radicals, ethyl radicals, propyl radicals, butyl radicals, cyclohexyl radicals, pentyl radicals, hexyl radicals, decyl radicals, dodecyl radicals and octadecyl radicals. Examples of C 1 to C 8 aryl radicals represented by R 6, R 8 and R 9 are benzyl radicals and naphthyl radicals. Preferred mercapto groups are those having the formula HS-R 10 wherein R "10 is an organic di-radical corresponding to those derived from R5 and R7. Preferably, R10 is ethylene, n-propylene, n-butylene, and in general C? -C, 8 hydrocarbons optionally interdispersed with S S II II -NH-, -NR-, -O-, -S-, -C-, -C-S, or one of the heteroatom-containing groups that have been previously identified. More preferably, R10 is C2_6 alkylene, most preferably C2-C3 alkylene, and in particular n-propylene. Suitable examples of groups R ^ SR '"^ include -CH2SH, -C2H4SH, - C3H6SH, (HSCH2) 2CHCH CH2-, (HSCH ^ CH ^ CCHzCH, -, (HSCH2CH2) (HSCH2) CHCH (CH2SH) CH2CH2CH2-HS (CH2) 3CH (CH2CH2SH) CH2CH2CH (CH2CH3) -, (HSCHJCH ^ CHC ^ CHJ -, (HSCH2) 2 (C2H5) CCH2SCH2CH2CH3 -, (HSCH2) 3CCH2SCH2CH2CH2 -, (HSCHiXHSCHzCHiCH ^ K? CHSCHjCHjCHj -, (HSCH2CH,) 2C? CH2SCH2CH2CH2 -, (HSCH2) 2 (C2H3) CCH2SCH2CH2S (SCH2) 3 -, ( HSCH ^ CCHaSíCH ^ StC? ^ -, S II (HSCH2) 2CHCH2CSCH2CH2CH2- S11 (HSCH2) 3CCH2CSCH2CH2CH2 - • (HSCH2) 2 (C2H5) CCH2SCCH2CH2CH2- 'O I! (HSCH2) 2 (C2H5) CCH2SCH2CH (CH3) COCH2CH2CH2- and the like. The groups with organic-organic or mercapto-organic functional groups are linked to silicon atoms which are contained in the organopolysiloxanes, preferably organopolysiloxanes which contain moieties analogous to the preceding formulas I, II, III and IV, but in which the substituents which are other than organic-amino groups and mercapto-organic groups are preferably R groups, more preferably methyl groups or lower alkoxy groups, whose presence is sometimes dictated by the synthesis method that is used. The content of alkoxy groups is therefore generally less than 20 weight percent, more preferably less than 10 weight percent, and generally between about 0.1 weight percent and 8 weight percent. Fluids with amino-organic functions have amine equivalents that are at least about 0.01 meq / g, more preferably at least 0.1 meq / g, and most preferably at least 1 meq / g, and as maximum preferably 7 meq / g, more preferably 3 meq / g. Organopolysiloxanes with mercapto-organic functions generally contain above 0.01 weight percent of -SH groups, more preferably above 0.1 weight percent, and preferably less than 5 weight percent, more preferably less of 2 weight percent. The substantially linear poly (dimethylsiloxanes), with amino-alkyl and mercaptoalkyl functions, are the organopolysiloxanes with preferred organic functions, more preferably those containing silsesquisiloxane groups having an amino-organic or mercapto-organic functionality bonded thereto. Organopolysiloxanes with amino functions and mercapto functions can be prepared by conventional methods, ie by hydrosilylation of unsaturated amines or mercaptans by organopolysiloxanes with hydrogen functions in the presence of a catalyst for hydrosilylation. Such functional organopolysiloxanes are available on a commercial scale.

It has surprisingly been found that not all mixtures of hydrophobically modified organopolysiloxanes and organopolysiloxanes with organic functions are inherently suitable for use as release agents. In particular, it has been found that the suitability depends on the physical stability of the mixture. The physical stability is determined by a simple test involving centrifuging a 50 ml sample contained in a 50 ml capacity conical centrifuge tube at 3000 rpm in an IEC Centra 8 Model 2476 centrifuge, manufactured by International Equipment Company. An angled rotor, 822a is used. The sample is centrifuged for one hour. The samples are carefully taken from the top and the bottom after centrifugation, and analyzed for their content of organic functional groups. Classical analyzes are used, for example acid titration for siloxanes with amino functions and titration with silver nitrate for siloxanes with mercapto functions. Other analytical methods are also suitable. A mixture is stable if the molar ratio of functional groups in the upper part compared to that in the lower part is between 0.9 and 1.1, and preferably in the range of 0.93 to 1.07. If the mixture is stable, in the sense described above, it will be suitable as an effective release agent at the same time that it will also be paintable. Preferred stable blends contain from 0.02 to about 8 weight percent of an organopolysiloxane with organic functions, more preferably from 0.05 to about 3.0 weight percent. Blends that are not stable are less effective as release agents and also require vigorous cleaning in order to be painted satisfactorily. Therefore, pure and stable mixtures comprising organopolysiloxanes modified with organic functions and hydrophobically modified organopolysiloxanes constitute an embodiment of the present invention. It has also surprisingly been found that mixtures of organopolysiloxanes modified with organic functions and hydrophobically modified organopo-lysiloxanes are not stable, ie they are outside the molar ratio of 0.9 to 1.1 between the top and the bottom. , will provide excellent demoulding and in addition will be paintable, if dissolved in an organic solvent in a concentration of about 10 weight percent or less, preferably less than 6 weight percent. Preferred organic solvents include aromatic compounds such as toluene and xylene; alcohols such as isopropyl alcohol and n-propanol; aliphatic solvents such as mineral spirits, petroleum ether, heptane, cyclohexane and the like; and volatile siloxanes such as hexamethyl-cyclotrisiloxane and octamethyl-cyclotetrasiloxane. The stability of these mixtures should be such that the molar ratio between the upper part and the lower part is preferably between 0.5 and 1.4, and more preferably 0.8 to 1.2, when the concentration of siloxane components in the solvent is less than about 10 weight percent, and more preferably less than 6 weight percent. Illustrative mixtures are separation-prone mixtures containing from 3 weight percent to about 20 weight percent of an organopolysiloxane with organic functions, more preferably from 3 weight percent to about 10 weight percent based on the total content of organosilicon compound. The stable mixtures can also be applied from a solvent. Unexpectedly, however, unstable solvent-based formulations have proven to be superior to stable solvent-based formulations, when the concentrations of the demoulding agent mixture are less than about 10 weight percent. The demolding agents of the present invention, whether stable or unstable, can also be applied from aqueous emulsions or dispersions (both referred to herein as "emulsions"). Most preferably, microemulsions are preferred, ie those having particle sizes of the dispersed phase in the range of less than 1 μm. Such emulsions are prepared by conventional methods, and preferably employ a non-ionic surfactant having a hydrophilic-lipophilic balance (HLB) value of 11-14 and preferably 12-13. Mixtures of surfactants having low and high HLB values can also be used. The amount of the surfactant is conventional, and generally ranges from about 3 weight percent to about 8 weight percent, more preferably between 4 weight percent and 6 weight percent for an emulsion containing 60 weight percent of the mixture of this invention. The amount of mold release agent employed in a molding operation will depend on the material from which the mold is constructed, its surface finish, the depth of the section, the molding temperature, etc., all of which are well known to the manufacturers. experts in the art. The amount will also depend on the polymer that is molded, with aggressively adhering polymers such as a polyurethane RIM and an epoxy polymer generally requiring larger amounts. Polymers or their reactive precursor systems containing internal mold release agents may require less of a release agent. The actual amount can be determined by simple scoring techniques. If necessary, the unmixed release compositions can be diluted with an appropriate solvent or emulsified in water. The solutions and emulsions can be further diluted as necessary. Additional demolding substances may be added if desired, such as fatty alcohols, fatty esters, fatty carboxylates and metal soaps, etc. Waxes, both natural and synthetic, can be added, without mixing, in solution, or as a dispersion. The fluids of poly (dimethylsiloxanes) can not be added, in general, unless it is desired to employ the release agent for moldings that do not have to be painted.

Additives that may be useful include hydrophobic silica with very small particle size, ie a silica having a surface area greater than 40 m2 / g, preferably greater than 100 m2 / g. Preferably, any non-soluable solid additives are present in amounts of less than 5 weight percent, more preferably less than 2 weight percent, in order to avoid buildup on the mold surface or surface contamination of the part molded Organic dyes can be added to help determine if complete mold coverage has been obtained. However, the dyes will preferably be absent. Organic and inorganic viscosifying agents may be useful, particularly for aqueous emulsions. Examples of suitable viscosifying agents are the various vegetable gums, ie those of carrageenan, tragacanth, guar, arabic and the like; various alkylated and carboxylated celluloses, such as carboxymethyl- and carboxypropyl celluloses; polyacrylates, in particular poly (acrylic acids) and their copolymers, such as the various polymers Carbopol ™ and Acrysol ™; and inorganic thickening agents such as finely divided silicas and clay materials. Associative thickeners may also be useful. Examples of associative thickeners include hydrophobic polymers terminated with hydrophilic and / or polar groups, and in particular copolymers of poly (oxyethylene) and poly (oxypropylene) terminated with C.sub.8-3 oxyalkylene moieties. Having generally described this invention, it is possible to obtain an Further understanding by reference to certain specific examples that are provided herein for purposes of illustration only and that are not intended to be limiting, unless otherwise specified. In the following Examples, a two-part polyurethane molding composition is chosen because of its aggressive adhesive properties. A mold consisting of a cold-rolled steel cylinder with the lower part closed, the upper part open, and a height of one inch (2.54 cm) is used as a mold. The side walls have a thickness of approximately 0.25 inches (0.6 cm). The candidate mold release agents are liberally applied by means of a brush, and fifteen grams of a reactive polyurethane consisting of 69.4% by weight of Conthane® TU-401 Part A and 30.6% by weight are poured into the mold. Conthane® TU-401 Part B, both available from Tool Chemical Co., Madison Heights, Michigan, and allowed to cure for 2 hours at 80 ° C in an oven with forced air circulation. Before pouring the reactive polyurethane into the mold, the head of a bolt having a diameter of 5/16 inches (0.8 cm) is suspended in the center of the mold so that the head will be encapsulated. The opposite end of the bolt has a ring to make it possible to remove the molded part from the mold. In some examples, open aluminum molds are used instead.

It is believed that the release agent, or "mold-release component" Organosilicone Fluid L-42, available from Witco Corporation, Organosilicon Group, is a polyorganosiloxane containing methyl groups and a-methyl-phenylethyl groups linked to the silicon atoms. . It is believed that the release agent or release component "Reléase Agent TN", available from Wacker Silicons, Adrián, Michigan, is a similar organopolysiloxane containing methyl groups, phenylethyl groups and dodecyl groups attached to silicon. Both of these release agents correspond to the "hydrophobically modified organopolysiloxanes" of the present invention.

COMPARATIVE EXAMPLE C1 A commercial release agent Organosilicone Fluid L-42 is applied to the mold before pouring into it and curing the polyurethane. The molded part is allowed to cool to room temperature before determining the force required to remove the part from the mold. A manually held Chatillon ™ gauge is attached to the ring and a voltage is applied. The maximum force required for the withdrawal is noted. The piece could not be taken out. It had to be cut and removed from the mold. The L-42 fluid does not provide detachment.

COMPARATIVE EXAMPLE C2 The procedure of Comparative Example 1 is repeated except that Reléase Agent TN produced by Wacker Chemie is used in place of agent L-42. The molded part could not be removed from the mold. The molded piece had to be cut and removed from the mold. The mold release agent TN does not provide any detachment with this mold and this polymer system.

COMPARATIVE EXAMPLE C3 The procedure of Comparative Example C1 is repeated except that a thin-walled open aluminum tray is used for the mold and a bolt is not used. The Reléase Agent TN produced by Wacker Chemie is used as a demolding agent. The aluminum must be separated from the part using pliers. It is very difficult to separate the piece from the mold, which breaks into pieces when it is removed from the piece. The molded piece is painted with a red acrylic varnish for cars, but the paint does not cover the piece well. Another piece is molded and separated from an aluminum tray and the piece is rubbed with a paper towel. The molded part is painted with a red acrylic varnish for automobiles as before. A good coating is obtained and this is free of "orange peel" and "fish eye" defects.

COMPARATIVE EXAMPLE C4 The procedure of Comparative Example C1 is repeated three times except that a mixture consisting of 0.75 weight percent dimethyl polysiloxane with amino functions and 99.25 weight percent of a methyl-terminated dimethyl polysiloxane, which has a viscosity of 350 cSt, is the demolding agent used. The dimethyl polysiloxane fluid with amino functions having an amine content of 0.00014 equivalents per gram (0.14 meq / g), a methoxy content of 0.6 weight percent, has a viscosity of about 400 cSt, and an amine functionality which is a silsesquioxane group containing an aminoethyl aminopropyl group. Only 1 pound (0.45 kg) of force is required to remove the part from the mold. The piece is painted without having cleaned it and the coating obtained is very irregular, containing many "fish eyes". Another piece is rubbed with a paper towel and then painted. Although it is better than the first painted piece, it still has many superficial flaws. The piece is scrubbed with Citrikleen®, a product of Penetone Corporation, and then washed with water. The piece is dried and then painted. There are some "fish eyes" on the surface. This example illustrates the need for rigorous cleaning of molded parts with polysiloxanes containing poly (dimethyl siloxane) groups.

COMPARATIVE EXAMPLE C5 The procedure of Comparative Example C1 is repeated except that the stripping composition is a mixture consisting of 1 weight percent of a methoxy-terminated dimethylpolysiloxane fluid having a viscosity of about 12 cSt and 99 percent in Weight of the Reléase Agent TN described above. The dimethyl polysiloxane contains 7.4% methoxy groups. The test is carried out in triplicate. Approximately 10 pounds (4.5 kg) of force is required to remove two of the pieces. The third piece could not be detached. This example demonstrates that the groups with amino-organic and / or mercapto-organic functions of the present invention are necessary to achieve a good release. The pieces are not painted.

COMPARATIVE EXAMPLE C6 The procedure of Comparative Example C5 is repeated except that the stripping composition is first dissolved in toluene, at a concentration of 10 weight percent. Two of the molded parts could not be separated from the molds. The third required a force of 27.5 pounds (12.375 kg) to be removed. The pieces are not painted. This example further demonstrates the need for the functional groups of the present invention to achieve a low release force, and also demonstrates that dilution with a solvent usually results in molded parts that adhere more aggressively to the molds.

COMPARATIVE EXAMPLE C7 The procedure of Comparative Example C3 is followed. A solution consisting of 10 weight percent of a dimethyl polysiloxane with amino functions and 90 weight percent of xylene is the mold release composition used. Three pieces of urethane are molded. The mold has to be broken into pieces when it is removed from the urethane piece. The first piece is painted without having cleaned it and the coating obtained is very irregular, containing many "fish eyes". Another piece is rubbed with a paper towel and then painted. Its appearance is similar to the appearance of the first piece. It still has many superficial defects. The third piece is scrubbed with Citrikleen®, a product of Penetone Corporation, and then washed with water. The piece is dried and then painted. The piece has multiple "fish eyes". This example demonstrates that even with a vigorous cleaning the dimethyl-polysiloxane with amino functions is not removed from the piece, besides being a bad release agent.

EXAMPLE 1 A mixture (A) is prepared by mixing 1 weight percent of a dimethyl polysiloxane having amino functions with 99 weight percent of an Organosilicone Fluid L-42 produced by Witco Corporation, Organosilicones Group. A second mixture (B) is prepared by mixing 1 weight percent of a dimethyl polysiloxane having amino functions with 99 weight percent of the Reléase Agent TN produced by Wacker Chemie. The dimethyl polysiloxane fluid having amino functions has an amine content of 0.0014 equivalents per gram (1.4 meq / g), a methoxy content of 7 weight percent, a viscosity of about 20 cSt, and an amine functionality which is a silsesquioxane group containing an aminoethyl aminopropyl group. The mixture (A) is transparent and the mixture (B) is cloudy. Both mixtures are formulations that are within the scope of the invention. Each of the mixtures is applied to two molds and the procedure of Comparative Example C1 is followed to produce molded parts. One of the pieces is painted immediately and the second piece is painted after the surface of the piece has been rubbed with a paper towel. The piece molded with the mixture (A) has a few minor defects in the untreated part. The rubbed piece has no surface defects. The part molded with the mixture (B) has several surface defects in the untreated part. The rubbed part is free of superficial defects. Each piece requires a force of one pound (0.45 kg) to remove it from the mold. An excellent detachment is obtained. The mixture (B) is centrifuged for one hour at 3000 rpm. A sample from the upper part and another from the lower part are evaluated for their amine content. The one in the upper part contains 0.00016 equivalents per gram and the one in the lower part contains 0.00017 equivalents per gram. The ratio of the functional groups in the upper part to the functional groups in the lower part is 0.94.

EXAMPLE 2 A mixture (C) is prepared by mixing 1 weight percent of a dimethyl polysiloxane having mercaptan functions with 99 weight percent of the Reléase Agent TN. The dimethyl polysiloxane having mercaptan functions contains about 0.8 weight percent of SH groups, has a viscosity of about 70 cSt, and the mercaptan functionality is carried by a silsesquioxane group having a mercaptopropyl group attached thereto. The resulting cloudy mixture is centrifuged for one hour at 3000 rpm. A sample is taken from the bottom and another from the top. The mercaptan (SH) content is determined by evaluating the mixture with silver nitrate. It is found that the one in the upper part has 0.008 weight percent SH and that in the lower part has 0.008 weight percent SH. The ratio of the functional groups in the upper part to the functional groups in the lower part is 1, 0. Two pieces of urethane are prepared following the procedure of Comparative Example C1. One pound (0.45 kg) of force is required to remove the pieces from the molds. The first piece is painted and the coating is very irregular and the paint does not cover the piece in an effective way. The second piece is rubbed before being painted and a uniform coating is obtained.

EXAMPLE 3 A mixture (D) is prepared by mixing 3 weight percent of the dimethyl polysiloxane having mercaptan functions of Example 2 with 97 weight percent of the Reléase Agent TN. The resulting cloudy mixture is centrifuged for one hour at 3000 rpm. A sample is taken from the upper part and another from the lower part. The mercaptan (SH) content is determined by evaluating the mixture with silver nitrate. It is found that the one in the upper part has 0.013 weight percent SH and that in the lower part has 0.026 weight percent SH. The ratio of the functional groups in the upper part to the functional groups in the lower part is 0.5. Two pieces of urethane are prepared following the procedure of Comparison Example C1. A force of one pound (0.45 kg) was required to remove the pieces from the molds. The first piece was painted and the coating was very irregular and the paint did not cover the piece effectively. The second piece is rubbed before being painted. Defects of "orange peel" and "fish eyes" are very evident. You get a bad coating. The mixture (D) is mixed with xylene at a concentration of 10 weight percent. Two pieces of urethane are prepared following the procedure of Comparative Example C1. A force of approximately 5 pounds (2.25 kg) is required to remove the pieces from the mold. The first piece is painted and a good coating is obtained. The second piece is rubbed and then painted. An excellent coating is obtained.

EXAMPLE 4 The mixture (B) from Example 1 is mixed with xylene at a concentration of 10 weight percent. The resulting solution is applied to two molds and two pieces of urethane are molded following the procedure of Comparative Example C1. The first piece is painted and an excellent coating is obtained. The second one is rubbed and then painted. An excellent coating is obtained. A release force of 8.3 pounds (3.735 kg) is required to remove the urethane parts from the molds. The procedure is repeated with a 5 weight percent solution of (B) in xylene. A force of 30 pounds (13.5 kg) does not remove the piece from the mold. The xylene solution does not contain any sufficient amount of the release agent, although it may be suitable for polymers that adhere less aggressively, eg polypropylene.

EXAMPLE 5 A mixture (F) is prepared by mixing 5 weight percent of a dimethyl polysiloxane having amino functions with 95 weight percent of the Reléase Agent TN produced by Wacker-Chemie. The dimethyl polysiloxane fluid with amino functions has an amine content of 0.0014 equivalents per gram (1.4 meq / g), a methoxy content of 7 weight percent, a viscosity of about 20 cSt and has a amine functionality in silsesquioxane groups containing an aminoethyl aminopropyl group. The mixture (F) is cloudy. The mixture is centrifuged for one hour at 3000 rpm. A sample taken from the upper part and another from the lower part are evaluated in terms of the amine content. The upper part contains 0.000067 equivalents per gram and the lower part contains 0.000085 equivalents per gram. The ratio of the functional groups in the upper part to the functional groups in the lower part is 0.79. A solution consisting of 5 percent by weight of the mixture (F) in xylene is applied to two molds and the procedure of Comparative Example C1 is followed to produce moldings. One of the pieces is painted immediately and the second piece was painted after the surface of the piece had been rubbed with a paper towel. The piece molded with the mixture has a few minor defects in the un-rubbed part. The rubbed piece has no surface defects. Each piece requires a force of 4.3 pounds (1, 935 kg) to remove it from the mold.

EXAMPLE 6 A mixture (G) is prepared by mixing 1 weight percent of a dimethyl polysiloxane with amino functions and 99 weight percent of the Reléase Agent TN produced by Wacker-Chemie. The dimethyl-polysiloxane fluid with amino functions has an amine content of 0, 00014 equivalents per gram (0.14 meq / g), a methoxy content of 0.6 percent by weight, a viscosity of approximately 400 cSt, and carries silsesquioxane groups containing an aminoethyl-aminopropyl group. The mixture is cloudy. This mixture is applied to two molds and the procedure of Comparative Example C1 is followed to produce molded parts. One of the pieces is painted immediately and the second piece is painted after the surface of the piece has been rubbed with a paper towel. The untwisted part has numerous surface defects. The rubbed piece does not present superficial defects. Each piece requires a force of one pound (0.45 kg) to remove it from the mold. An excellent detachment is obtained.

The mixture (G) is centrifuged for one hour at 3000 rpm. A sample taken from the upper part and another taken from the lower part are evaluated in terms of the amine content. The upper part contains 0.000002 equivalents per gram and the lower part contains 0.000002 equivalents per gram. The ratio of the functional groups in the upper part to the functional groups in the lower part is 1, 0.

EXAMPLE 7 A mixture (H) is prepared by mixing 1 weight percent of a dimethyl polysiloxane with amino functions and 99 weight percent of the Reléase Agent TN produced by Wacker-Chemie. The dimethyl polysiloxane fluid with amino functions has an amine content of 0.0005 equivalents per gram (0.5 meq / g), a methoxy content of 2.6 weight percent, a viscosity of about 60 cSt, and contains silsesquioxane groups containing an aminoethyl aminopropyl group. The mixture is cloudy. This mixture is applied to two molds and the procedure of Comparative Example C1 is followed to produce the molded parts. One of the pieces is painted immediately and the second piece is painted after the surface of the piece has been rubbed with a paper towel. The untwisted part has numerous surface defects. The rubbed piece has no surface defects. The pieces require a force of 1.8 pounds (0.81 kg) to remove them from the mold. An excellent detachment is obtained.

The mixture (G) is centrifuged for one hour at 3000 rpm. A sample from the upper part and another from the lower part are evaluated in terms of amine content. The one in the upper part contains 0.000005 equivalents per gram and the one in the lower part contains 0.000005 equivalents per gram. The ratio of the functional groups in the upper part to the functional groups in the lower part is 1, 0.

EXAMPLE 8 A mixture (I) is prepared by mixing 1 weight percent of a dimethyl polysiloxane with methyl-terminated amino functions with 99 weight percent of the Reléase Agent TN produced by Wacker-Chemie. The dimethyl polysiloxane fluid with amino functions has an amine content of 0.00014 equivalents per gram (0.14 meq / g), a viscosity of about 500 cSt and contains silsesquioxane groups containing an aminoethyl aminopropyl group. The mixture is cloudy. The mixture is applied to two molds and the procedure of Comparative Example C1 is followed to produce molded parts. One of the pieces is painted immediately and the second piece is painted after the surface of the piece has been rubbed with a paper towel. The untwisted part has numerous surface defects. The rubbed piece has no surface defects. The pieces require a force of 1 pound (0.45 kg) to remove them from the mold. An excellent detachment is obtained.

EXAMPLE 9 An emulsion of the mixture (B) is prepared by mixing 7.0 parts of a nonionic surfactant with 6 parts of water. The mixture (B) is added to the resulting mixture in 60 parts. 33 parts of water are carefully added to this mixture. A stable white emulsion with a particle size of the dispersed phase of 309 nanometers is obtained. The emulsion is applied to a mold as described in Comparative Example C1. The mold is allowed to dry and then a piece of urethane is produced according to the procedure of Comparative Example C1. The mold is allowed to dry and then a piece of urethane is produced according to the procedure of Comparative Example C1. The piece of urethane could be separated from the mold. The foregoing experiments demonstrate that the hydrophobically modified organopolysiloxanes do not provide a high release capacity, particularly when used with reactive polyurethanes in deep section molds (Comparative Examples C1-C3). However, if removal of the mold is possible in some way, the pieces are not immediately paintable, but they can be painted satisfactorily after having rubbed the surface with a dry towel or with a dry cloth (Comparative Example C3). The experiments also demonstrate that mixtures of fluids with amino functions and conventional poly (dimethylsiloxane) fluids (Comparative Example C4) provide excellent detachment, but exceptionally poor drawability. Such mold release compositions can not be used in many applications, for example as release agents for automotive polyurethane RIM parts. In Comparative Example C5, the importance of the aminoalkyl or mercaptoalkyl functional groups in organopolysiloxane with organic functions is demonstrated. Substitution by a siloxane with methoxy functions of the siloxanes with organic functions of the present invention required a greater detachment force than desired when the pieces could have been released in some way. The example Comparative C6 illustrates that the application of an unmixed release agent of Comparative Example C5, dissolved in a solvent, does not improve the release, rather, the part adheres more aggressively to the mold. Comparative Example C7 demonstrates that fluids with aminoalkyl functions alone are very ineffective demolding agents. Despite using a mold with a deep section, the mold must be destroyed when it is removed from the piece. Moreover, the piece exhibited an almost 3 failure Complete with regard to paintability even after having cleaned it with a powerful cleansing agent and having washed it with water. Examples 1 and 2 demonstrate the efficacy of stable and pure mixtures of a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions. Both Examples A and B exhibited exceptional demolding properties as well as good paintability after being rubbed. Example 6 demonstrates that a stable mixture containing only one-tenth of the aminoalkyl functionality, as used in Example 1, still provides exceptional detachment. Example 7 is intermediate between these examples in terms of aminoalkyl functionality. Example 3 demonstrates that unstable mixtures (molar ratio of the functional groups in the upper part to those in the lower part of 0.5) of a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions provide excellent demoulding at despite the instability, but they are quite deficient in terms of paintability. Surprisingly, however, after having diluted it with a solvent, a modest increase in the peeling force is observed, but the paintability is restored. Unstable mixtures are appropriate when dissolved in a solvent. Example 5 illustrates that the unstable mixtures (molar ratio of the groups in the upper part to the groups in the lower part of 0.79) are satisfactory if they are dissolved in a solvent.

Example 4 illustrates that the release force can be altered by increasing or decreasing the solvent content in the mold release solutions. It is generally observed that a higher solvent content, and of course the presence of any solvent, increases the force required to remove the piece. Example 9 indicates that the aqueous emulsions of the present compositions also function as effective release compositions. The invention described herein can be practiced with any combination of named necessary ingredients, particularly those identified as "preferred", with the exclusion of other named or unnamed ingredients. The necessary ingredients comprise a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions, as defined herein, in a stable and pure mixture, or a stable or stable mixture dissolved in an organic solvent or emulsified to form an aqueous dispersion. By the terms "one" and "one" are meant "one or more" unless the context clearly indicates something else. By the term "analogous composition suitable to" in reference to a stable composition is meant a different composition in terms of the amounts of ingredients, the molecular weight, the content of hydrophobic groups, the content of functional groups or other properties or compositions or a combination of it, but which belong to the same general class of compositions, the unstable composition having a 4"molar ratio between the groups in the upper part to the groups in the lower part" located outside the range of 0.9 to 1, 1. By a "molar ratio between the groups in the upper part to the groups in the lower part" is meant the molar ratio of functional groups in the upper part and in the lower part of a sample after centrifugation, as previously defined . Although embodiments of the invention have been illustrated and described, these embodiments are not intended to illustrate and describe all possible forms of the invention. Instead, the words used in the specification are words of description rather than words of limitation, and that various changes can be made without departing from the spirit and scope of the invention.

Claims (17)

NOVELTY OF THE INVENTION CLAIMS

1. An unmixed stripping composition, which provides paintability to the castings, comprising a stable mixture of a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions, said organopolysiloxane containing organic functional groups both amino-organic functional groups and mercapto functional groups organic, or at the same time amino-organic and mercapto-organic functional groups.

2. The unmixed stripping composition of claim 1, wherein said hydrophobically modified organopolysiloxane comprises a branched or linear polyorganosiloxane containing traces of the formulas R SiO, 1/2 (I) RaRlSiOvl (II) RXSiOV2 (III) SiO 4/2 (IV) in which R is a lower alkyl or alkylene, optionally interrupted by ether oxygen or thioether sulfur; R1 is a C-C30 hydrophobic group that optionally contains no more than one ether oxygen or one thioether sulfur when the carbon content is less than C-? 0, and no more than two ether oxygen atoms or sulfur thioether when the carbon content is C 0 or higher, R 1 containing an insufficient amount of -O and / or -S- dispersed atoms to cancel the water repellency of the hydrophobicizing group R 1.

3. The unmixed desmoid agent of claim 1, wherein said organopolysiloxane with organic functions contains one or more of the groups R6HN-X- and HS-X- wherein X is a hydrocarbyl linking group C? .30 which optionally contains one or more heteroatoms interposed of -O- and -S- and groups containing heteroatoms O -NH-, -NR-, -C-, -C-O, O-C-O, -O-S-, -O- S -O- O O S S II. II II II -O-C-NH-, -NH-C-NH-, -C-, -C-S, wherein R is hydrogen or an alkyl or aryl C C 8 radical.

4. The unmixed stripping agent of claim 2, wherein said organopolysiloxane with organic functions contains one or more of the groups R HN-X- and HS-X- wherein X is a hydrocarbyl linking group C? 3o which optionally contains one or more heteroatoms interposed of O- and -S- and groups containing heteroatoms O O O O O II II II II II -NH-, -NR-, -C-, -CO, OCO, -OS-, -OS -O- OOSS -OC-NH-, -NH-C-NH-, -C-, -CS, wherein R6 is hydrogen or an alkyl or aryl C C? 8 radical.

5. The unmixed mold release composition of claim 1, wherein said organopolysiloxane with amino-organic functions contains amino-organic groups corresponding to the formulas VII. -R ° - [(NR 6 °) -CR.7 '] 1t.MNPR8 ° 0R9' (VII) wherein Rd is a divalent CrC18 hydrocarbyl radical, R6 is a hydrogen atom or an unsubstituted C? -C? 8 alkyl radical, R7 is a divalent CC? 8 hydrocarbyl radical, R8 is a hydrogen atom or an alkyl radical or unsubstituted CrC10 aryl radical, R9 is a hydrogen atom or an unsubstituted alkyl radical or aryl radical CrC10, and t is an integer from 0 to 6.

6. The unmixed demolding agent of claim 1, in the said mercaptoalkyl group comprises one or more of the groups - CH2SH, - C2H SH, - C3H6SH, (HSCH2) 2CHCH2CH2 -, (HSCHjCH ^ \ HSCH ^ CHICH,), -, (HSCH2) CH2) 3CCH2CH2 -, (HSCHjCHiXHSCH ^ CHCHíCHzSHJCHzCH ^ H, -, HSÍCH ^ CHÍCHZCHJS ^ CHZCH ^ HÍCHJCHJ) -, (HSCH ^ JCHSCHÍCHJCHJ -, (HSCH2) 2 (C2H3) CCH2SCH2CH2CH3 -, (HSCH2) 3CCH2SCH2CH2CH2 -, (HSCH ^ íHSCHjCHiCHiCH ^ CHSCHzCHjCHz -, (HSCH2CH2) 2CHCH2SCH2CH2CH2 -, (HSCH2) 3CCH2S (CH2) 3S (CH2) 3 -, (HSCH2) 2CHCH2CSCH2CH2CH2- S II (HSCH2) 3CCH2CSCH2CH2CH, - (HSCH2) 2 (C2H5) CCH2SCCH2CH2CH2 - and O (HSCH2) 2 (C2H5) CCH2SCH2CH (CH3) COCH2CH2CH2-

7. - The unmixed release agent of claim 5, in which mercapto-alkyl group comprises one or more of the groups - CH2SH, - C2H4SH, - C3H6SH, (HSCH2), CHCH2CH2 -, (HSCHjCH ^ \ HSCH ^ CHYCHJ ^ -, (HSCHZCH ^ \ HSCH ^ CHCHíCHzSHJCHzC ^ CH, - HS (CH2) JCH (CH2CH2SH) CH2CH2CH (CH2CH3) -, (HSCH ^ ÍÍCJHJJCCHÍSCHJCHZCHJ -, (HSCH2) 3CCH2SCH2CH2CH2 -, (HSCH ^ íHSCHiCHzCHiCH ^ CHSCHzCHzCHi -, (HSCH2CH2) 2CHCH2SCH2CH2CH2 -, (HSCH2) 2 (C2HJ) CCH2SCH2CH2S (SCH 2) 3 -, (HSCH,) 3CCH2S (CH2) 3S ( CH2) 3 -, (HSCH2) 2CHCH2CSCH2CH2CH2- - 'S ll (HSCH2) 3CCH2CSCH2CH2CH2- • S (HSCH2) 2 (C2H5) CCH2SCCH2CH2CH2- and O (HSCH2) 2 (C2H5) CCH2SCH2CH (CH3) COCH2CH2CH2-

8. The unmixed release agent of claim 1, wherein the molar ratio of the functional groups in the upper part and the functional groups in the lower part is between about 0.93 and about 1.07.

9. - The unmixed release agent of claim 1, wherein the organopolysiloxanes with organic functions comprise one or more of the poly (dimethylsiloxanes) with functions α-aminopropyl, poly (dimethylsiloxanes) with β-aminoethyl- functions aminopropyl and poly (dimethylsiloxanes) with? -mercaptopropyl functions.

10. A solution of a demolding agent in an organic solvent that provides pintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable demolding composition of claim 1; b) an unstable demolding composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions, having a molar ratio of the functional groups in the upper part to the functional groups in the lower part that is less than 0 , 9 or greater than 1, 1.

11. A solution of a release agent in an organic solvent that provides pintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable demolding composition of claim 1; b) a suitable mold release composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a molar ratio of the functional groups in the upper part to the functional groups in the lower part which is less than 0 , 9 or greater than 1.1, wherein said modified organopolysiloxane hydrophobically comprises a branched or linear polyorganosiloxane, which contains moieties of the formulas RaRbSiO? 2 (I) RaRlSiOvz (H) SiOy? (III) SiO 4/2 (IV) and wherein R is lower alkyl or alkylene, optionally interrupted by an ether oxygen or a thioether sulfur; R1 is a C-C30 hydrophobic group optionally containing no more than one ether oxygen or one thioether sulfur when the carbon content is less than Cio, and no more than two ether oxygen atoms or thioether sulfur when the carbon content is C 1 or higher, R 1 containing an insufficient amount of -O and / or -S- interdispersed atoms to cancel the water repellency of the R1 water repellent group.

12. A solution of a mold release agent in an organic solvent that provides pintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable mold release composition of claim 1; b) an unstable demold composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a molar ratio of the functional groups in the upper part to the functional groups in the lower part which is smaller in that organopolysilaxane with organic functions 0.9 or greater than 1.1, wherein said organopolysiloxane with organic functions contains one or more of the groups R6HN-X- and HS-X- in which X is a C1-C30 hydrocarbyl linker group optionally contains one or more heteroatoms interposed of -O- and -S- and groups containing heteroatoms -NH-, -NR-, -C-, -C-O, O-C-O, -O-S-, -O- S -O- O O S S II II II II -O-C-NH-, -NH-C-NH-, -C-, -C-S,

13. - A solution of a release agent in an organic solvent that provides pintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable demolding composition of claim 1; b) an unstable demolding composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a molar ratio of the functional groups in the upper part to the functional groups in the lower part which is less than 0, 9 or greater than 1.1, wherein said organopolysiloxane with aminoalkyl functions contains aminoalkyl groups corresponding to the formulas VII -R5 - [(NR6) -R7] tNR8R9 (VII) wherein R5 is a divalent C -? - C18 hydrocarbyl radical, R6 is a hydrogen atom or an unsubstituted C? -C? 8 alkyl radical, R7 is a divalent CC? 8 hydrocarbyl radical, R8 is a hydrogen atom or an unsubstituted alkyl radical or CrC10 aryl radical, R9 is a hydrogen atom or an unsubstituted C1-C10 alkyl or aryl radical, and t is an integer from 0 to 6.

14.- A solution of a mold release agent. in an organic solvent that provides paintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable demixing composition of claim 1; b) an unstable demolding composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a molar ratio of the functional groups in the upper part to the functional groups in the lower part which is less than 0, 9 or greater than 1, 1, wherein said mercaptoalkyl group comprises one or more groups between - CH2SH, - C2H4SH, - C3H6SH, (HSCH2) 2CHCH2CH2 -, (HSCH2CH2) (HSCH2) CH (CH2) 4 -, (HSCH2CH2) (HSCH2) CHCH (CH2SH) CH2CH2CH2 -, HS (CH2) 5CH (CH2CH2SH) CH2CH2CH (CH2CH3) -, (HSCH2CH2) 2CHCH2CH2 -, (HSCH2) 2CHSCH2CH2CH2 -, (HSCH2) 2 (C2H3) CCH2SCH2CH2CH3 -, (HSCH2) (HSCH2CH2CH2CH2) CHSCH2CH2CH2 -, (HSCH2CH2) 2CHCH2SCH2CH2CH2 -, (HSCH2) 2 (C2Hj) CCH2SCH2CH2S (SCH2) 3 -, (HSCH2) 3CCH2S (CH2) 3S (CH2) 3 -, (HSCH2) 2CHCH2CSCH2CH2CH2- > S II (HSCH2) 3CCH2CSCH2CH, CH7- ' (HSCH2) 2 (C2H5) CCH2SCCH2CH2CH2- > I II (HSCH2) 2 (C2H5) CCH2SCH2CH (CH3) COCH2CH2CH2-

15. - A solution of a mold release agent in an organic solvent that provides paintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable mold release composition of claim 1, that the molar ratio of the functional groups in the upper part to the functional groups in the lower part is between approximately 0.93 and approximately 1.07; b) a suitable mold release composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a ratio of the functional groups in the upper part to the functional groups in the lower part of less than 0.9 or greater than eleven.

16. A solution of a demolding agent in an organic solvent that provides pintability to the molded parts, the solution comprising, in addition to one or more organic solvents, one or more compositions between a) the stable demolding composition of claim 1; b) a suitable mold release composition comprising a hydrophobically modified organopolysiloxane and an organopolysiloxane with organic functions having a molar ratio of the functional groups in the upper part to the functional groups in the lower part which is less than 0 , 9 or greater than 1.1, in which the organopolysiloxane with organic functions comprises one or more of the poly (dimethylsiloxanes) with functions α-aminopropyl, poly (dimethylsiloxanes) with β-aminoethyl-aminopropyl and poly ( dimethyl siloxanes) with functions? -mercaptopro-pilo.

17. A method for molding and painting molded polymeric parts, said method comprising: a) supplying a mold intended to receive a molten or reactive polymer composition on at least one of the surfaces; b) applying to the surface of said mold a demolding composition comprising a release agent selected from one or more of the groups consisting of: b) i) a stable and pure mixture of one or more hydrophobically modified organopolysiloxanes and one or more organopolysiloxanes with organic functions; b) ii) a solution of b) i) or a similar analogous solution to b) i) dissolved in one or more organic solvents; and b) i¡¡) an aqueous emulsion of b) ¡) or an analogous emulsion unstable to b) i); c) introducing a molten polymer or reactive polymer composition into said mold; d) removing a molded polymer part from said mold; e) optionally cleaning said molded part; and f) painting said molded part, whereby a painted part substantially free of defects in the paint is obtained, wherein said organopolysiloxane with organic functions comprises one or more between an organopolysiloxane with aminoalkyl functions or an organopolysiloxane with mercaptoalkyl functions.