KR0147201B1 - Method of manufacturing silicone resin releasing agent - Google Patents

Abstract

The present invention relates to a water-soluble silicone resin release agent and a method for producing the same. The water-soluble silicone resin mold release agent of this invention consists of a silicone resin, a nonionic surfactant, and an anionic surfactant hardening catalyst. The release agent of the present invention forms a semi-permanent film on the surface of the molding mold with only silicone resin emulsion without adding any reinforcing agent or filler, so that it is easy to demold when forming rubber and synthetic resin products, and the secondary processing of the molded product is possible. It is a water-soluble silicone resin releasing agent excellent in heat resistance, abrasion resistance and durability.

Description

Water Soluble Silicone Resin Release Agent And Manufacturing Method Thereof

The present invention relates to a water-soluble silicone resin releasing agent and a method for producing the same. More specifically, the oil-in-water oil of a silicone resin obtained by adding a nonionic surfactant, an anionic surfactant and a curing catalyst to water phase transition in water to the silicone resin of the following general formula The present invention relates to a water-soluble silicone resin releasing agent composed of an emulsion and a method of manufacturing the same.

Wherein R is methyl or phenyl and R ¹ , R ² , R ³ , and R ⁴ each represent a crosslink followed by a methyl group or silicon-oxygen-silicon.

Since silicone resins are oil-based, silicone resin releasing agents generally use organic solvents, but these releasing agents have various disadvantages such as being harmful to the human body, causing fire and explosion and environmental pollution by using organic solvents. Its use was extremely limited.

In addition, a water-soluble releasing agent using an emulsion of silicone is known to improve the disadvantages of the releasing agent using an organic solvent, but since the effect is changed as a releasing agent according to the type of silicone resin, its selection is recognized as an important problem.

Release agents using monomers of cyclookcamethyltetrasiloxane as emulsions of silicones are generally well known (see US Pat. Nos. 2,891,920, 3,294,725, 3,355,406, 3,360491 and 3,698,469). In the manufacturing method of this mold release agent, the use of additives, such as a hardening catalyst, a silane crosslinking agent, and a reinforcing agent, is added separately to the oily emulsion obtained by emulsion polymerization using a strong acid, a strong base, or a polymerization catalyst from the said monomer. In addition, a method has been reported in which a silane crosslinker and various fillers are mixed with polydimethylsiloxane, methylvinylpolysiloxane, methylhydropolysiloxane, and the like, and then emulsified using an anionic surfactant, and a curing catalyst is added thereto (US Pat. No. 4,248,751 4,273,634, 4,568,718 and 4,584,341).

On the other hand, the release agent emulsifying only lolidiorganosiloxane oil among the currently released mold release agents is applied to a molding mold to form a film, and then hardened. Therefore, if the product is stained with oil or needs secondary processing such as adhesion or painting, it is washed or wiped. There is inconvenience to pay and sustainability is not good. In view of these disadvantages, polydiorgano silo acid oil emulsions use various additives such as silane crosslinking agents and fillers, and add a catalyst for curing to form a cured film after application. It is used as a release agent to facilitate processing (see Korean Patent Publication Nos. 93-9729, US Patent Nos. 2,891,920, 3,355,406, 3,306,491, 4,248,751, 4,273,634, 4,568,718 and 4,584,341 number).

The above techniques may cause corrosion of the mold by using strong acid or strong alkali during emulsification, and if the release agent is cured or does not cure during storage, it does not cure after application, resulting in poor storage stability. In addition, due to the use of additives in the silicone oil, the amount of accumulation in the mold increases as the use time of the release agent increases, so it is inconvenient to clean the mold frequently, and it may be adversely affected on the appearance of the product.

In the present invention, a method of directly emulsifying a mixture of the co-hydrolyzed silicone resin type of the above-mentioned general formula, which has not yet been studied to solve the above-mentioned disadvantages, has been developed. Thus, by using a thermosetting silicone resin, , To minimize the disadvantages of water-soluble mold release agent using silicone oil, to apply to the surface of the mold of a certain condition and to form a film that is cured after evaporation of water to give the release property, persistence, etc. and to minimize the residue on the mold to adversely affect the product appearance Secondary processing is easy without affecting and without special treatment. In addition, the field test results showed that the performance was the same or more effective release agent compared to the water-soluble release agent added various fillers to the silicone oil.

Accordingly, it is an object of the present invention to provide a water-soluble silicone resin release agent composed of an oil-in-water emulsion of a silicone resin obtained by phase-transferring a silicone resin, a nonionic surfactant, an anionic surfactant, and a curing catalyst in water.

Wherein R is methyl or phenyl and R ¹ , R ² , R ³ , and R ⁴ each represent a crosslink leading to a methyl group or silicon-oxygen-silicon.

The present invention also provides a method for producing a water-soluble silicone resin releasing agent consisting of adding and mixing a nonionic surfactant and a curing catalyst to the silicone resin of the general formula, adding and mixing an aqueous solution of an anionic surfactant, and then performing phase transition in water. do.

Silicone resins are generally polysiloxanes whose molecular structure is three-dimensionally crosslinked and can be prepared by hydrolyzing a mixture of monochloroorganosilanes, dichloroorganosilanes, trichloroorganosilanes or tetrachloroorganosilanes. When the mixture of chlorosilanes is dissolved in a suitable solvent and hydrolyzed, the bond between silicon and chlorine is hydrolyzed to generate hydrogen chloride and become silanol. Since this silanol is unstable, most of the silanes are condensed immediately and converted into siloxane bonds. The hydrolyzed silicone resin has about 3-6% silanol groups (W. Noll Chemistry and Technology of silicones, Academic Press, New York, 1968).

Among the units constituting the silicone resin, most of the substituents bonded to silicon are MeSiO _1-5 , PhSiO _1-5 , Me ₂ SiO, Ph ₂ SiO and PhMeSiO, and their compounding ratios are variously copolymerized. Increasing methyl content in silicone resin improves flexibility, water repellency, fast curing, stable to chemicals and UV rays, and good surface gloss (LH Brown, Silicon in protective coatings in film forming composions, Vol. 1, part III, RR Meyers and JS Long, Eds, Marcel Dekker, New York, 1972). The molecular structure types of the silicone resins synthesized to date include organic silanes having only three organic groups or organic silanes having one organic group bonded to silicon and the remaining three bonds being functional groups such as halogen or alkoxy which can be hydrolyzed. There are two types of organosilanes in which a functional group is mixed in an appropriate ratio. Therefore, the number of substitutions indicating the number of organic groups bonded to the silicon of the silicone resin is on average between 1.1 and 1.9, which is greater than 1 and less than 2. As mentioned above, a silicone resin composed of only three organosilanes having a functional group forms a film suitable for many purposes and can be used as a release agent.

In this case, however, the film is brittle and inflexible. Therefore, an appropriate amount of two functional organosilanes are mixed. Therefore, even after forming the film, even if it withstands any impact and bumps, the film does not crumble. In preparing the silicone resin, if the average value of the functional groups bonded to silicon is different, the properties of the resin are also different. Therefore, in order to obtain the properties of the silicone resin suitable for the purpose of use, the average value of the functional group should be selected well, and for this, organic trichlorosilane and organic dichlorosilane should be mixed in an appropriate ratio.

The silicone resin used in the present invention is a silicone resin of the general formula which exhibits the maximum effect as a releasing agent while sufficiently collecting these properties and emulsifying the silicone resin in the form of oil in water.

This silicone resin has an organosilane of formula (I) having three hydrolyzable functional groups and an organosilane of formula (II) having two hydrolysable functional groups. Bissilyl methane (Korean Patent Application No. 91-24243) may be prepared by co-gas decomposition in toluene or a mixed solvent of toluene and acetone (Korean Patent Application No. 92-3204).

Wherein R is methyl or phenyl, X is a chlorine or methoxy group and R ¹ , R ² , R ³ , and R ⁴ are methyl, hydrogen or chlorine, respectively. In addition, the co-hydrolyzed silicone resin is a compound of formula (I) having three hydrolysable functional groups of 40-70 mol%, of the general formula (II) having two hydrolysable functional groups It is composed from 20-60 mole% of the compound and 1-10 mole% of the bissilylmethane compound so that the average grouping period of the organic group is between 1.2-1.7.

The silicone resin (hydrolyzate product of the silane mixture) prepared in this way is co-hydrolyzed to contain 30-70% by weight, preferably 40-60% by weight, based on the total amount of oil-in-water emulsion of the silicone resin according to the invention. Add. When the resin solution is less than 30% by weight, the phase transition to oil-in-water is easy and stable in the emulsion, but it is not a reasonable production condition. When it exceeds 70% by weight, it is difficult to be phase-in-water-in-oil and oil-in-water. Even if the phase change, the safety of the emulsion is not good.

Nonionic surfactants and anionic surfactants are used as emulsifiers. Nonionic surfactants are generally used in the range of H-18 (Hydrophilic Lipophilic Balance) used in oil-in-water emulsification, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tree Sorbitan derivatives such as stearate, sorbitan monooleate, sorbitan trioleate and polyoxyethylene fatty acid esters, polyoxyethylene tridecyl ether, colloxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene Polyoxyethylene oxide derivatives such as lauryl ether are used.

Since anionic surfactants have a large hydrophilic group, they are easily combined with water molecules to form small particle diameters, and exist in the atmosphere or separation around silicon particles to make the particles of the emulsion very fine, thereby inducing stability of the emulsion and freezing of the electrolyte. Although it is used, it generates a lot of bubbles, which lowers the storage stability, so that when used in combination with an antifoaming agent and the above nonionic surfactant, a stable emulsion can be obtained. Examples of anionic surfactants include sodium dodecylbenzenesulfonate, sodium benzenesulfonate, sodium laurylsulfonate, sodium oxyethylene lauryl ether sulfonate, ammonium polyoxyethylene nonyl phenol ether sulfonate and the like.

On the other hand, the indenter size of the emulsifier is proportional to the concentration of the emulsifier, and as the amount of the emulsifier increases, the particle size decreases, but the water resistance decreases. Therefore, the amount of use must be adjusted within the range of suitable stability according to the particle size, reaction time, and the like. Generally, the amount of emulsifier used is about 3-10% by weight based on the total amount of the emulsion, and is suitable for use in the range of 2-6% by weight for the nonionic surfactant and 1-4% by weight for the anionic surfactant. Particle size and stable emulsion can be made. The mixing ratio of these surfactants can also be determined by varying the flow rate in accordance with the desired effect.

When the silicone resin emulsion of the present invention is used as a releasing agent, an oil-in-water emulsion of silicone resin is prepared by adding a curing catalyst so that the silicone resin, which is a residual oil coating, can be cured in a short time after evaporation and drying of dilution water. do. The curing catalyst may be added at any stage in the oil-in-water emulsion production process of the silicone resin. However, if the curing catalyst is added after the oil-in-water emulsion forming step of the silicone resin, the curing catalyst itself is not water-soluble and thus must be emulsified again. Alkaline tin carboxylates such as dimethyltin laurate, dibutytin dilaurate, octyl tin laurate may be used as the curing catalyst, and dibutyltin dilaurate is preferable. The amount of this curing catalyst used is 1-5% by weight based on the total amount of emulsion. The amount of curing catalyst can be adjusted by the specific molar composition ratio of the resin. If the amount of catalyst is too small, it will not be cured under the temperature condition of 150 ° C or the curing rate will be slow to achieve the required purpose. It does not affect the speed but rather adversely affects the stability of the emulsion.

In the present invention to form an oil-in-water emulsion, as a dispersion medium, the water is easily mixed while maintaining a uniform viscosity of the entire reaction mixture and serves to evenly transfer the supply heat from the outside. At this time, natural water and tap water have polyvalent metal ions, and since these metal ions are a detrimental factor in obtaining a stable emulsion, it is preferable to use soft water or distilled water and ion exchange water.

The amount of water used is 20-65% by weight, preferably 30-40% by weight, based on the total amount of the emulsion.

To the oil-in-water emulsion of the silicone resin thus obtained, a viscosity stabilizer, a preservative, or the like may be added as necessary to maintain storage stability for a long time.

The water-soluble silicone resin releasing agent according to the present invention is added anionic surfactant and water at the same time while slowly stirring while maintaining the internal temperature of the container at 30 ℃ by adding a nonionic surfactant to the silicone resin, the speed is increased and stirred for about 2-3 minutes Phase-change into oil-in-water form and then quenched by raising the temperature to 70 ° C. for the stability of the emulsion and then quenching the oil-in-water emulsion of the silicone resin, and then adjusting the active ingredient of the known oil-in-water oil emulsion obtained according to the application. It can then be prepared by adding a large amount of ion-exchanged water and by oscillating ultrasonic waves specifically for their dispersion stability.

The following examples illustrate the invention in more detail, but the invention is not limited thereto.

Example 1

The 1 liter three-necked flask was equipped with a mechanical stirrer in the center and a condenser and a dropping funnel on each side. In order to prevent the reaction temperature from changing during the reaction, a bath containing ice water was installed under the flask. 82.2 g (0.55 mol, 55 mol%) of methyltrichlorosilane, 45.2 g (0.35 mol, 35 mol%) of dimethyldichlorosilane, 1,1,1,3-tetrachloro-3-methyl-1,3 in a dropping funnel 24.3 g (0.1 mole, 10 mole%) of disilabuta was added to the flask to give 60% solids of the resulting resin solution after hydrolysis, and 50.1 g of toluene and 10.1 g of acetone corresponding to 20% of toluene were hydrolyzed. 495 g of water corresponding to 10 times the number of moles of silicon-chlorine bond were added thereto. Toluene and water in the flask form a heterogeneous system that does not mix with each other, so that the silane mixture is slowly dropped from the dropping funnel while stirring vigorously using a mechanical stirrer. The silane mixture was allowed to fall at a constant rate and the time required was 30 minutes. After the injection of silane was stirred for an additional hour to complete the hydrolysis. The solution was transferred to a separatory funnel and left to separate immediately into a water layer and an organic solvent layer. After removing the lower water layer, the remaining hydrochloric acid was washed three times by adding about 200ml of water, and then separated and removed. After washing, neutrality was obtained by adding about 10 g of anhydrous titanium sulfate to the resin solution to remove residual water, and then filtering sodium sulfate with a filter to obtain a clear resin solution (molecular weight 5,000).

Example 2

The one-liter three-necked flask was equipped with a mechanical stirrer in the center and a dropping funnel and thermometer on each side. An electric mantle was installed to keep the flask internal temperature at a moderate level. 60 g of the silicone resin solution synthesized in Example 1) was added to the flask, and 3 g of polyoxyethylene nonylphenyl ether (20 mol of ethylene oxide added), 1 g of sorbitan monolaurate, and 1 g of dibutyltin dilaurate were added. Stirring slowly for about 5 minutes while maintaining the temperature, add a mixture of 5g of sodium dodecylbenzenesulfonate (50% by weight of active ingredient) and 30g of ion-exchanged water through a dropping funnel. After stirring, the phase transition was carried out in the form of oil in water, and then the temperature was gradually raised to 70 ° C. and rapidly cooled using ice water to synthesize a stable oil-in-water emulsion of silicone resin.

Example 3

The oil-in-water emulsion of the silicone resin synthesized in Example 2 was left at room temperature for 48 hours at 25 ° C., and then diluted with 230 ml of ion-exchanged water so that the solid content was 1.5% at 150 ° C., and then the ultrasonic wave at 15 KHz for 1 minute was used. Oscillation was carried out to prepare a water-soluble silicone resin release agent using an oil-in-water emulsion of a silicone resin.

In a field experiment in which the water-soluble silicone resin releasing agent was spray-coated to a rubber mold having a temperature of 150 ° C., a thin film was formed together with evaporative drying of water as a solvent, and the properties of the resin remaining after curing were soft and smooth. In addition, mold release and continuity were good even at more than 20 times of demolding, and the secondary operation of the molding was easy, and there was almost no corrosion of the mold or formation of contaminants. This result gives the maximum effect with this agent.

Example 4

As shown in Table 1 below, each silicone resin solution was synthesized under the same conditions and methods as in Example 1, except that only the type of silane used for hydrolysis was used.

Example 5

As shown in the following Table 2, using the respective silicone resin solution synthesized in Example 4, the oil-in-water emulsion was synthesized in the same manner as in Example 2 by varying only the amount of emulsifier, catalyst, and water.

Example 6

As a result of diluting the oil-in-water emulsion of the silicone resin synthesized in Example 5 in the same manner as in Example 3, a thin film was formed with evaporation and drying of the solvent, and the curing rate was slightly different. As a result, the remaining resin was flexible and smooth and did not appear. Also, more than 20 times of demolding showed good releasability and sustainability, and the secondary processing of the molding was easy. These results can be seen to give the maximum effect as a release agent.

Claims (6)

A water-soluble silicone resin releasing agent comprising an oil-in-water emulsion of a silicone resin obtained by phase-transferring a silicone resin, a nonionic surfactant, an anionic surfactant, and a curing catalyst in water Wherein R is methyl or phenyl and R ¹ , R ² , R ³ , and R ⁴ each represent a crosslink leading to a methyl group or silicon-oxygen-silicon. The nonionic surfactant according to claim 1, wherein the nonionic surfactant is sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, polyoxyethylene A water-soluble silicone resin releasing agent characterized in that it is selected from fatty acid fat esters, polyoxyethylene tridecyl ether, colliethylene ethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene lauryl ether. The method of claim 1, wherein the anionic surfactant is selected from sodium dodecylbenzenesulfonate, sodium benzenesulfonate, sodium laurylsulfonate, sodium oxyethylene lauryl ether sulfonate, ammonium polyoxyethylene nonyl phenol ether sulfonate Water-soluble silicone resin release agent characterized in that. The water-soluble silicone resin release agent according to claim 1, wherein the curing catalyst is selected from dimethyltin lyrate, dibutyltin dilauretiti and octyltin laurate. A nonionic surfactant is added to and mixed with a silicone resin of the following general formula, an aqueous solution of an anionic surfactant is added and mixed, followed by a phase shift in water to obtain an oil-in-water emulsion of the silicone resin. Wherein R is methyl or phenyl and R ¹ , R ² , R ³ , and R ⁴ each represent a crosslink leading to a methyl group or silicon-oxygen-silicon. 6. The production method according to claim 5, wherein the oil-in-water emulsion of the silicone resin is further diluted with ion-exchanged water, at which time the ultrasonic wave is oscillated to stabilize the emulsification.