A self-condensation type silicone emulsion and a method for preparing the same

Abstract

The application provides a self-condensation type silicone emulsion, which is prepared from raw materials comprising the following components: 250-400 parts by weight of linear polydimethylsiloxane; 50-100 parts by weight of a silicone resin; 50-100 parts by weight of a functional additive; 30-70 parts by weight of a surfactant; and 330-620 parts by weight of water; the unit chain of the silicone resin is: [R'3SiO 0.5 ] M [R"SiO 1.5 ] T [SiO2] Q ; wherein R' and R" are independently selected from a phenyl group, a methyl group, an ethyl group, an aminoethyl group or an aminopropyl group, (R'+R") / Si is 1.1-1.5, and the hydroxyl content is 0.5%-4%. Compared with the prior art, the self-condensation type silicone emulsion provided by the application realizes better interaction by using components with specific contents, and has the following advantages: no catalyst is needed, is safe and environmentally friendly, has adjustable performance, is simple to use and has wide application, and can be applied in the fields of cosmetics, concrete waterproofing, coating hand feeling modification, fabric waterproofing and the like.

Description

Technical Field

[0001] This invention relates to the field of organosilicon emulsion technology, and more specifically, to a self-condensing organosilicon emulsion and its preparation method. Background Technology

[0002] Organosilicon, due to its unique chemical structure, possesses excellent heat resistance, breathability, flexibility, and low surface energy, making it widely applicable in industries such as construction, textiles, and cosmetics. Typically, uncrosslinked and cured silicone oils lack any mechanical properties, so a certain amount of metal catalyst is often added to the active silicone oil system to promote the reaction between active groups. Currently, commonly used metal catalysts are organotin catalysts or platinum catalysts. Tin catalysts are used in condensation systems, but they possess a certain degree of toxicity, limiting their application. Platinum catalysts, on the other hand, are addition systems, which are more expensive, and the inhibitors present within the system require high-temperature treatment; otherwise, a two-component system needs to be prepared, requiring mixing before use, which is cumbersome. Some waterproof silicone emulsions are often silane and silicone resin or simple silane emulsions. Although they can react without a catalyst, they contain a large number of hydrolyzed free small molecules, resulting in high VOC content. Furthermore, some only modify the surface of the substrate, resulting in poor mechanical strength, which cannot meet the needs of high-end applications.

[0003] Chinese Patent Publication No. CN102219551A discloses a breathable organosilicon waterproofing agent, composed of an active ingredient, a solvent, and a catalyst. The active ingredient is characterized by being prepared by hydrolysis of an alkylsiloxane coupling agent and / or a fluoroalkylsiloxane coupling agent with a solvent under acid or alkali conditions. The siloxane coupling agent has the structural formula: R n -Si(OR') 4-n In the formula, R is a saturated long-chain alkyl group with 3 to 12 carbon atoms, or a perfluorinated or partially fluorinated saturated long-chain alkyl group with 3 to 12 carbon atoms, R' is methyl or ethyl, and n is 1 or 2. This waterproofing agent, by introducing fluorinated alkylsiloxanes, not only possesses excellent waterproofing and breathability, but also exhibits good adhesion, acid and alkali resistance, and aging resistance. However, this method only yields a waterproofing agent with surface modification function for the substrate, resulting in poor mechanical properties and the presence of a large amount of solvent.

[0004] Chinese Patent Publication No. CN103043946A discloses an organosilicon waterproof emulsion, which is composed of the following raw materials in the following weight ratios: 1-100 parts of silane or siloxane containing active groups, 4-100 parts of silane coupling agent, 1-20 parts of emulsifier, and 600-22000 parts of water. This invention also provides a preparation method, comprising: 1) adding silane or siloxane containing active groups and water to a reaction vessel equipped with a stirrer and stirring for approximately 0.8-1.2 hours; 2) adding the silane coupling agent, emulsifier, and water to another reaction vessel equipped with a stirrer and stirring for approximately 1.5-2.5 hours; 3) mixing the mixtures obtained in steps 1) and 2) and emulsifying them in an ultrasonic emulsifier to obtain a milky-white organosilicon waterproof emulsion; this emulsion has the advantages of strong penetration and long-lasting waterproof performance. However, because the main active ingredient of this waterproofing agent is a silane coupling agent, a large amount of low-molecular-weight substances will be generated during the curing process, and this waterproofing agent is only suitable for the construction industry such as concrete.

[0005] Chinese patent CN103787612A discloses a method for preparing an emulsion-type waterproof and mildew-resistant silicone waterproofing agent. The preparation steps are as follows: First, octyltriethoxysilane, silicone resin prepolymer, and a nonionic surfactant are added to a plastic cup and stirred until homogeneous. Then, the mixture is poured into a high-shear emulsifier, and deionized water is added in several batches. A buffer solution is then added to adjust the pH to 6-7, resulting in a 40% waterproofing agent emulsion. A silane quaternary ammonium salt is then added to the 40% waterproofing agent emulsion and stirred until homogeneous, yielding a concentrated waterproof and mildew-resistant solution A. However, this preparation method produces a large amount of hydrolysate, and the product has low mechanical strength.

[0006] Chinese patent CN104327723A discloses a transparent, highly elastic organosilicon waterproofing agent and its preparation method. The method involves adding hydroxyl-terminated polysiloxane, methyltriethoxysilane oligomer, and solvent to a high-speed stirrer and mixing thoroughly. Then, an organotin catalyst is added and stirred until homogeneous, yielding the transparent, highly elastic organosilicon waterproofing agent. However, the waterproofing agent prepared by this method contains a large amount of organic solvent and tin catalyst, causing environmental pollution. Summary of the Invention

[0007] To address the shortcomings and deficiencies of existing technologies, the present invention aims to provide an environmentally friendly, simple to prepare, and easy-to-construct self-condensing "soft-hard" segmental structure organosilicon emulsion and its preparation method. The emulsion exhibits self-condensing curing characteristics at room temperature / heat, and no metal catalyst is required during the curing process. The organosilicon emulsion is prepared using a "one-pot method," eliminating the need for adding an aqueous phase via a pump during emulsification. The material is subjected to high-pressure work by a high-pressure homogenizer, which simultaneously applies mechanical forces such as high-speed shearing, high-frequency oscillation, cavitation, and convective impact, as well as corresponding thermal effects. This disperses the metastable, coarse emulsion with large particle size formed during the initial mixing process into a micron-sized organosilicon emulsion.

[0008] This invention provides a self-condensing silicone emulsion, prepared from raw materials comprising the following components:

[0009] 250 to 400 parts by weight of linear polydimethylsiloxane;

[0010] 50 to 100 parts by weight of silicone resin;

[0011] Functional additives, 50 to 100 parts by weight;

[0012] Surfactant 30 parts by weight to 70 parts by weight;

[0013] 330 to 620 parts by weight of water;

[0014] The unit chain segment of the silicone resin is:

[0015] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0016] R' and R” are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, (R'+R”) / Si is 1.1 to 1.5, and the hydroxyl content is 0.5% to 4%.

[0017] Preferably, the linear polydimethylsiloxane has the following structural formula:

[0018]

[0019] Wherein, n is 280–1500, m is 200–800, R is methoxy, ethoxy, or hydroxyl, and R3 is methyl, vinyl, phenyl, trifluoropropyl, or an alkane with 8–16 carbon atoms.

[0020] Preferably, the structural formula of the functional additive is:

[0021]

[0022] Wherein, R1 is methyl, methoxy, ethoxy or hydroxyl, R2 is phenyl or an alkane group with 2 to 10 carbon atoms substituted by aromatic group, amino group, urea group, methacryloyloxy group, mercapto group or epoxy group, and p+q is 15 to 80, where p is 10 to 70 and q is 5 to 20.

[0023] Preferably, the surfactant is selected from one or more of nonionic surfactants, anionic surfactants, and cationic surfactants; wherein, the nonionic surfactant is selected from one or more of Span series, Tween series, polyethylene glycol fatty acid esters, fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, isomeric alcohol polyoxyethylene ethers, nonylphenol polyoxyethylene ethers, and paraffin emulsifiers; the cationic surfactant is selected from one or more of fatty amine salts, ethanolamine salts, and polyethylene polyamine salts; and the anionic surfactant is selected from one or more of anionic polyacrylamide, fatty acid salts, sulfonates, sulfate esters, and phosphate esters.

[0024] This invention also provides a method for preparing the self-condensing silicone emulsion described in the above technical solution, comprising the following steps:

[0025] a) A linear polydimethylsiloxane, silicone resin, and functional additives are mixed to form a homogeneous organosilicon mixture;

[0026] b) Mix the organosilicon mixture obtained in step a) with surfactant and water to form a base emulsion;

[0027] c) The base emulsion obtained in step b) is homogenized, and then subjected to pH adjustment, pre-curing and neutralization treatments in sequence to obtain a self-condensing silicone emulsion.

[0028] Preferably, step b) specifically comprises:

[0029] The surfactant and the organosilicon mixture obtained in step a) are stirred and mixed evenly, and then water is added dropwise under strong stirring to form a basic emulsion.

[0030] Preferably, the speed of the high-intensity stirring is 1000 r / min to 2000 r / min.

[0031] Preferably, the homogenization process in step c) is performed using a high-pressure homogenizer; the pressure of the homogenization process is 400 bar to 800 bar.

[0032] Preferably, the process of sequentially adjusting pH, pre-curing, and neutralizing in step c) specifically comprises:

[0033] Add alkali to the homogenized base emulsion to make the pH ≥ 10, pre-curing for 5 h to 8 h, then add acid to neutralize, and obtain a self-condensing silicone emulsion.

[0034] or,

[0035] Acid was added to the homogenized base emulsion to make the pH ≤ 4. After pre-curing for 5 to 8 hours, alkali was added for neutralization to obtain a self-condensing silicone emulsion.

[0036] Preferably, the base is selected from inorganic bases and / or organic bases; wherein the inorganic base is selected from sodium hydroxide and / or potassium hydroxide, and the organic base is selected from triethylamine and / or diethylamine;

[0037] The acid is selected from inorganic acids and / or organic acids; wherein the inorganic acid is selected from hydrochloric acid and / or sulfuric acid, and the organic acid is selected from citric acid and / or acetic acid.

[0038] This invention provides a self-condensing silicone emulsion, prepared from raw materials comprising the following components: 250-400 parts by weight of linear polydimethylsiloxane; 50-100 parts by weight of silicone resin; 50-100 parts by weight of functional additives; 30-70 parts by weight of surfactant; and 330-620 parts by weight of water; wherein the unit chain segment of the silicone resin is: [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q Wherein, R' and R” are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, (R'+R”) / Si is 1.1 to 1.5, and the hydroxyl content is 0.5% to 4%. Compared with the prior art, the self-condensing silicone emulsion provided by the present invention uses specific content components to achieve better interaction and has the following advantages: (1) No catalyst required: A self-condensing "soft-hard" segment structure silicone emulsion is obtained. This emulsion does not require a catalyst and can be cured into a film by self-condensation reaction with the evaporation of water at room temperature; (2) Safe and environmentally friendly: It can achieve Voc-free and physiologically inert characteristics by adjusting the formula; (3) Adjustable performance: The performance of the "soft-hard" block coating after self-condensation can be adjusted by adjusting the total proportion of silicone resin in the formula. The performance of the coating can also be adjusted by adjusting the ratio of M, T and Q in the silicone resin; (4) Simple to use: It can be cured by self-condensation at room temperature to form a "soft-hard" block polymer waterproof coating without high temperature heating; (5) Wide application: It can be widely used in cosmetics, concrete waterproofing, coating feel modification, fabric waterproofing and other fields.

[0039] In addition, the present invention can selectively add color paste, water-soluble silica sol, mildew inhibitor, reinforcing agent and other components as needed. The addition of other components will not affect the basic properties of the emulsion. By adding different functional additives, the special groups provided can enhance the adhesion to the substrate by intermolecular forces, and can be used for waterproofing of various substrate surfaces.

[0040] In addition, the preparation method provided by this invention is simple, easy to operate, and has mild and easy-to-control conditions, and has broad application prospects. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] This invention provides a self-condensing silicone emulsion, prepared from raw materials comprising the following components:

[0043] 250 to 400 parts by weight of linear polydimethylsiloxane;

[0044] 50 to 100 parts by weight of silicone resin;

[0045] Functional additives, 50 to 100 parts by weight;

[0046] Surfactant 30 parts by weight to 70 parts by weight;

[0047] 330 to 620 parts by weight of water;

[0048] The unit chain segment of the silicone resin is:

[0049] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0050] R' and R” are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, (R'+R”) / Si is 1.1 to 1.5, and the hydroxyl content is 0.5% to 4%.

[0051] In this invention, the self-condensing silicone emulsion is specifically a self-condensing "soft-hard" segment structure silicone emulsion, prepared from raw materials including linear polydimethylsiloxane, silicone resin, functional additives, surfactants and water, preferably prepared from linear polydimethylsiloxane, silicone resin, functional additives, surfactants and water; the linear polydimethylsiloxane, silicone resin and functional additives can be pre-cured under acid or alkali conditions, and after 5h to 8h of pre-curing, the emulsion obtained by neutralization with acid or alkali can then self-condense and cure into a film at room temperature as the water evaporates.

[0052] In this invention, the structural formula of the linear polydimethylsiloxane is:

[0053]

[0054] Wherein, n is 280–1500, m is 200–800, R is methoxy, ethoxy, or hydroxyl, and R3 is methyl, vinyl, phenyl, trifluoropropyl, or an alkane with 8–16 carbon atoms.

[0055] In this invention, when the value of n is outside this range, the film-forming performance of the emulsion after self-condensation is poor, affecting its application range and effect. If R is a group other than methoxy, ethoxy, or hydroxyl groups that can participate in the reaction, such as methyl, ethyl, or phenyl groups, then the linear polydimethylsiloxane cannot participate in the pre-curing and self-condensation reaction, resulting in the inability to form a film.

[0056] In a preferred embodiment of the present invention:

[0057] n is 1000, m is 200, R is methoxy, and R3 is vinyl;

[0058] or,

[0059] n is 280, m is 800, R is hydroxyl, and R3 is phenyl;

[0060] or,

[0061] n is 1500, m is 600, R is hydroxyl, and R3 is an alkane with 8 carbon atoms;

[0062] or,

[0063] n is 500, m is 300, R is hydroxyl, and R3 is methyl.

[0064] or,

[0065] n is 500, m is 350, R is hydroxyl, and R3 is an alkane with 16 carbon atoms.

[0066] The present invention does not impose any special restrictions on the source of the linear polydimethylsiloxane; commercially available products well known to those skilled in the art can be used.

[0067] In this invention, the unit chain segment of the silicone resin is:

[0068] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0069] R' and R” are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, wherein R' is preferably phenyl or methyl, R” is preferably methyl, aminoethyl or aminopropyl, (R'+R”) / Si is 1.1 to 1.5, and the hydroxyl content is 0.5% to 4%.

[0070] In this invention, when the (R'+R”) / Si ratio is less than 1.1, the content of functional groups in the silicone resin decreases, leading to a reduction in the strength of the film and its adhesion to the substrate after self-condensation, thus affecting its application range and performance. When the (R'+R”) / Si ratio is greater than 1.5, the silicone resin contains a large number of functional groups, resulting in reduced reactivity of the reactive hydroxyl groups, lower crosslinking density, and poor or no film formation performance after self-condensation. When the hydroxyl content is less than 0.5%, the content of reactive groups is low, which also leads to a lower crosslinking density, resulting in poor or no film formation performance after self-condensation. When the hydroxyl content is greater than 4%, the reactivity is too high, and the emulsion forms crosslinks during the acid or alkali-catalyzed pre-curing stage, producing colloidal particles, ultimately preventing film formation.

[0071] In a preferred embodiment of the present invention:

[0072] R' is phenyl, R” is methyl, (R'+R”) / Si is 1.1, and the hydroxyl content is 4%;

[0073] or,

[0074] R' is methyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 0.5%;

[0075] or,

[0076] R' is phenyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 2.5%;

[0077] or,

[0078] R' is methyl, R” is aminopropyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 0.8%;

[0079] or,

[0080] R' is methyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 3%.

[0081] The present invention does not impose any special restrictions on the source of the silicone resin; commercially available products well known to those skilled in the art can be used.

[0082] In this invention, the structural formula of the functional additive is:

[0083]

[0084] Wherein, R1 is methyl, methoxy, ethoxy or hydroxyl, R2 is phenyl or an alkane group with 2 to 10 carbon atoms substituted by aromatic group, amino group, urea group, methacryloyloxy group, mercapto group or epoxy group, and p+q is 15 to 80, where p is 10 to 70 and q is 5 to 20.

[0085] In this invention, the functional additives primarily provide three functions: first, they provide highly hydrophilic groups to improve emulsification, such as the amino and alkane groups in R2; second, they provide groups that do not participate in the reaction but have special functions, such as the amino, epoxy, and phenyl groups in R2, which can improve the adhesion to the substrate or the mechanical properties of the film after self-condensation; and third, they provide reactive groups to promote pre-curing and self-condensation, thereby improving the relevant properties of the film. Depending on the application effect, two or three of these functions can be selected to choose the functional additive. For example, if R1 is a methoxy group and R2 is an amino-substituted alkane group, the emulsification effect can be improved, pre-curing and self-condensation can be promoted, and adhesion to the substrate can be enhanced.

[0086] In this invention patent, if the number of carbon atoms substituted by the R2 functional group in the functional additive is greater than 10, it will lead to excessively low reactivity of the functional additive or affect its adhesion to the substrate. If p+q is less than 15, the functional additive chain length is short, the hydrolysis ability and reactivity are high, the stability is poor, and it is prone to cross-linking and gelation. If p+q is greater than 80, the functional additive chain length is long, the viscosity is high, which affects its dispersion in the system, thereby affecting its application range and effect.

[0087] In a preferred embodiment of the present invention:

[0088] R1 is methyl, R2 is aminoethyl, p+q is 15, where p is 10 and q is 5;

[0089] or,

[0090] R1 is methyl, R2 is an alkyl group with 4 carbon atoms substituted by an epoxy group, p+q is 30, where p is 15 and q is 15;

[0091] or,

[0092] R1 is methoxy, R2 is phenyl, p+q is 80, where p is 60 and q is 20;

[0093] or,

[0094] R1 is methyl, R2 is a phenyl-substituted alkane group with 2 carbon atoms, p+q is 75, where p is 70 and q is 5;

[0095] or,

[0096] R1 is a hydroxyl group, R2 is a 2-carbon alkane group substituted with a mercapto group, and p+q is 70, where p is 60 and q is 10.

[0097] The present invention does not impose any special restrictions on the source of the functional additives; commercially available products well known to those skilled in the art can be used.

[0098] In this invention, the surfactant is preferably selected from one or more of nonionic surfactants, anionic surfactants, and cationic surfactants; wherein, the nonionic surfactant is preferably selected from one or more of Span series, Tween series, polyethylene glycol fatty acid esters, fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, isomeric alcohol polyoxyethylene ethers, nonylphenol polyoxyethylene ethers, and paraffin emulsifiers; the cationic surfactant is preferably selected from one or more of fatty amine salts, ethanolamine salts, and polyethylene polyamine salts; and the anionic surfactant is preferably selected from one or more of anionic polyacrylamide, fatty acid salts, sulfonates, sulfate esters, and phosphate esters.

[0099] In a preferred embodiment of the present invention:

[0100] The surfactant is Span 80 and triethanolamine dodecylbenzenesulfonate in a mass ratio of 6:1; or, fatty alcohol polyoxyethylene ether AEO-9 and triethanolamine dodecylbenzenesulfonate in a mass ratio of 5:1; or, fatty alcohol polyoxyethylene ether AEO-9 and triethanolamine dodecylbenzenesulfonate in a mass ratio of 2:1; or, fatty alcohol polyoxyethylene ether AEO-9 and isotridecyl alcohol polyoxyethylene ether 1307 in a mass ratio of 2:1; or, fatty alcohol polyoxyethylene ether AEO-7 and isotridecyl alcohol polyoxyethylene ether 1310 in a mass ratio of 2:1.

[0101] The present invention does not impose any special restrictions on the source of the surfactant; commercially available products well known to those skilled in the art can be used.

[0102] In this invention, the solid content in the self-condensing "soft-hard" segment structure organosilicon emulsion is preferably 38% to 67% by mass; wherein the mass ratio of the total mass of linear polydimethylsiloxane, silicone resin and functional additives to the mass of surfactant is preferably 100:(5 to 20); wherein the mass ratio of the total mass of linear polydimethylsiloxane and silicone resin to the mass of functional additives is preferably 100:(10 to 33.33).

[0103] In this invention, when the solid content in the self-condensing "soft-hard" segment structure silicone emulsion is less than 38%, the final sample self-condenses into a film too slowly or fails to form a film; or it is prone to wrinkles or cracks, and cannot form a complete film; when it is greater than 67%, the sample viscosity is high, it is not easy to level, resulting in uneven film thickness during film formation; at the same time, the high viscosity will also make it difficult to disperse when mixed with other systems, affecting its application effect.

[0104] In this invention, when the content of the surfactant is less than the above proportion, the critical micelle concentration cannot be formed, and the mixture of linear polydimethylsiloxane with silicone resin and functional additives cannot be emulsified; when the content of the surfactant is greater than the above proportion, the transparency and performance of the film will decrease during curing, affecting its application range and effect.

[0105] In this invention, when the mass ratio of the functional additive to the total mass of linear polydimethylsiloxane and silicone resin is less than the aforementioned ratio, it will lead to difficulty in emulsification and instability of the emulsion after emulsification, making it prone to separation; or the final emulsion sample will fail to solidify into a complete film during the self-condensation stage, affecting its application range and effectiveness. When the mass ratio is greater than the aforementioned ratio, the excess functional additive cannot participate in the reaction, and the film formed after the pre-cured emulsion self-condenses is relatively soft, has poor performance, and has functional additive residues on the surface, affecting its application range and effectiveness.

[0106] The present invention does not impose any special restrictions on the water used; deionized water, which is well known to those skilled in the art, can be used.

[0107] This invention also provides a method for preparing the self-condensing silicone emulsion described in the above technical solution, comprising the following steps:

[0108] a) A linear polydimethylsiloxane, silicone resin, and functional additives are mixed to form a homogeneous organosilicon mixture;

[0109] b) Mix the organosilicon mixture obtained in step a) with surfactant and water to form a base emulsion;

[0110] c) The base emulsion obtained in step b) is homogenized, and then subjected to pH adjustment, pre-curing and neutralization treatments in sequence to obtain a self-condensing silicone emulsion.

[0111] The present invention first mixes linear polydimethylsiloxane, silicone resin and functional additives to form a homogeneous organosilicon mixture; then mixes the obtained organosilicon mixture with surfactant and water to form a basic emulsion.

[0112] In this invention, the linear polydimethylsiloxane, silicone resin, functional additives, surfactants, and water are the same as those in the above-described technical solutions, and will not be repeated here.

[0113] In this invention, the process of mixing the obtained organosilicon mixture with surfactant and water is preferably as follows:

[0114] The surfactant and the obtained organosilicon mixture were stirred and mixed evenly, and then water was added dropwise under strong stirring to form a basic emulsion.

[0115] In this invention, the preferred stirring speed is 1000 r / min to 2000 r / min.

[0116] After obtaining the base emulsion, the present invention performs homogenization treatment on the base emulsion, and then sequentially performs pH adjustment, pre-curing and neutralization treatment to obtain a self-condensing silicone emulsion.

[0117] In this invention, the homogenization process is preferably carried out using a high-pressure homogenizer; the homogenization pressure is preferably 400 bar to 800 bar, specifically 400 bar, 600 bar, or 800 bar.

[0118] In this invention, the process of sequentially adjusting pH, pre-curing, and neutralizing is preferably as follows:

[0119] Add alkali to the homogenized base emulsion to make the pH ≥ 10, pre-curing for 5 h to 8 h, then add acid to neutralize, and obtain a self-condensing silicone emulsion.

[0120] or,

[0121] Acid was added to the homogenized base emulsion to make the pH ≤ 4. After pre-curing for 5 to 8 hours, alkali was added for neutralization to obtain a self-condensing silicone emulsion.

[0122] In this invention, the alkali is preferably selected from inorganic alkalis and / or organic alkalis, more preferably inorganic alkalis or organic alkalis; wherein, the inorganic alkali is preferably selected from sodium hydroxide and / or potassium hydroxide, more preferably sodium hydroxide or potassium hydroxide, and the organic alkali is preferably selected from triethylamine and / or diethylamine, more preferably triethylamine or diethylamine. This invention does not impose any special restrictions on the source of the alkali; commercially available products well known to those skilled in the art can be used.

[0123] In this invention, the acid is preferably selected from inorganic acids and / or organic acids, more preferably inorganic acids or organic acids; wherein, the inorganic acid is preferably selected from hydrochloric acid and / or sulfuric acid, more preferably hydrochloric acid or sulfuric acid, and the organic acid is preferably selected from citric acid and / or acetic acid, more preferably citric acid or acetic acid. This invention does not impose any special restrictions on the source of the acid; commercially available products well known to those skilled in the art can be used.

[0124] This invention provides a self-condensing silicone emulsion, prepared from raw materials comprising the following components: 250-400 parts by weight of linear polydimethylsiloxane; 50-100 parts by weight of silicone resin; 50-100 parts by weight of functional additives; 30-70 parts by weight of surfactant; and 330-620 parts by weight of water; wherein the unit chain segment of the silicone resin is: [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q Wherein, R' and R” are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, (R'+R”) / Si is 1.1 to 1.5, and the hydroxyl content is 0.5% to 4%. Compared with the prior art, the self-condensing silicone emulsion provided by the present invention uses specific content components to achieve better interaction and has the following advantages: (1) No catalyst required: A self-condensing "soft-hard" segment structure silicone emulsion is obtained. This emulsion does not require a catalyst and can be cured into a film by self-condensation reaction with the evaporation of water at room temperature; (2) Safe and environmentally friendly: It can achieve Voc-free and physiologically inert characteristics by adjusting the formula; (3) Adjustable performance: The performance of the "soft-hard" block coating after self-condensation can be adjusted by adjusting the total proportion of silicone resin in the formula. The performance of the coating can also be adjusted by adjusting the ratio of M, T and Q in the silicone resin; (4) Simple to use: It can be cured by self-condensation at room temperature to form a "soft-hard" block polymer waterproof coating without high temperature heating; (5) Wide application: It can be widely used in cosmetics, concrete waterproofing, coating feel modification, fabric waterproofing and other fields.

[0125] In addition, the present invention can selectively add color paste, water-soluble silica sol, mildew inhibitor, reinforcing agent and other components as needed. The addition of other components will not affect the basic properties of the emulsion. By adding different functional additives, the special groups provided can enhance the adhesion to the substrate by intermolecular forces, and can be used for waterproofing of various substrate surfaces.

[0126] In addition, the preparation method provided by this invention is simple, easy to operate, and has mild and easy-to-control conditions, and has broad application prospects.

[0127] To further illustrate the present invention, the following embodiments will be described in detail.

[0128] Example 1

[0129] (1) Accurate weighing:

[0130] 250g of linear polydimethylsiloxane, with the following structural formula:

[0131]

[0132] Where n is 1000, m is 200, R is methoxy, and R3 is vinyl;

[0133] 50g of silicone resin, wherein the unit chain segment of the silicone resin is:

[0134] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0135] Wherein, R' is phenyl, R” is methyl, (R'+R”) / Si is 1.1, and the hydroxyl content is 4%;

[0136] 50g of functional additive, with the following structural formula:

[0137]

[0138] Wherein, R1 is methyl, R2 is aminoethyl, p+q is 15, where p is 10 and q is 5;

[0139] Mix the above three components to form a homogeneous organosilicon mixture.

[0140] (2) Mix 60g of surfactant Span 80 and 10g of triethanolamine dodecylbenzenesulfonate with the organosilicon mixture obtained in step (1) until homogeneous. Under strong stirring (1000r / min), gradually add 580g of water to form a basic emulsion.

[0141] (3) The base emulsion obtained in step (2) is homogenized by a high-pressure homogenizer at a pressure of 800 bar; then, an alkali (potassium hydroxide) is added to the homogenized base emulsion to make the pH of the emulsion = 10; after pre-curing for 7 hours, an acid (acetic acid) is added for neutralization to obtain a self-condensing "soft-hard" segment structure silicone emulsion; the self-condensing silicone emulsion can be packaged and stored in a sealed container.

[0142] Tests have shown that this self-condensing silicone emulsion has excellent waterproofing properties, exhibits self-condensing curing characteristics at room temperature / heat, requires no metal catalyst during curing, is environmentally friendly and easy to use, and has good adhesion to a variety of substrates, meeting various construction conditions.

[0143] Example 2

[0144] (1) Accurate weighing:

[0145] 400g of linear polydimethylsiloxane, with the following structural formula:

[0146]

[0147] Where n is 280, m is 800, R is hydroxyl, and R3 is phenyl;

[0148] 100g of silicone resin, wherein the unit chain segment of the silicone resin is:

[0149] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0150] Wherein, R' is methyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 0.5%;

[0151] 100g of functional additives, with the following structural formula:

[0152]

[0153] Wherein, R1 is methyl, R2 is an alkyl group with 4 carbon atoms substituted by an epoxy group, p+q is 30, where p is 15 and q is 15;

[0154] Mix the above three components to form a homogeneous organosilicon mixture.

[0155] (2) Mix 25g of surfactant fatty alcohol polyoxyethylene ether AEO-9, 5g of dodecylbenzenesulfonic acid triethanolamine salt and the organosilicon mixture obtained in step (1) until homogeneous. Under strong stirring (1500r / min), gradually add 370g of water to form a basic emulsion.

[0156] (3) The base emulsion obtained in step (2) is homogenized by a high-pressure homogenizer at a pressure of 400 bar; then acid (acetic acid) is added to the homogenized base emulsion to make the pH of the emulsion = 4; after pre-curing for 8 hours, alkali (diethylamine) is added for neutralization treatment to obtain a self-condensing "soft-hard" segment structure silicone emulsion; the self-condensing silicone emulsion can be packaged and stored in a sealed container.

[0157] Tests have shown that this self-condensing silicone emulsion has excellent waterproofing properties, exhibits self-condensing curing characteristics at room temperature / heat, requires no metal catalyst during curing, is environmentally friendly and easy to use, and has good adhesion to a variety of substrates, meeting various construction conditions.

[0158] Example 3

[0159] (1) Accurate weighing:

[0160] 250g of linear polydimethylsiloxane, with the following structural formula:

[0161]

[0162] Where n is 1500, m is 600, R is hydroxyl, and R3 is an alkane with 8 carbon atoms;

[0163] 50g of silicone resin, wherein the unit chain segment of the silicone resin is:

[0164] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0165] Wherein, R' is phenyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 2.5%;

[0166] 50g of functional additive, with the following structural formula:

[0167]

[0168] Wherein, R1 is methoxy, R2 is phenyl, p+q is 80, where p is 60 and q is 20;

[0169] Mix the above three components to form a homogeneous organosilicon mixture.

[0170] (2) Mix 20g of surfactant fatty alcohol polyoxyethylene ether AEO-9, 10g of triethanolamine dodecylbenzenesulfonic acid salt and the organosilicon mixture obtained in step (1) until homogeneous. Under strong stirring (2000r / min), gradually add 620g of water to form a basic emulsion.

[0171] (3) The base emulsion obtained in step (2) is homogenized by a high-pressure homogenizer at a pressure of 600 bar; then, an alkali (potassium hydroxide) is added to the homogenized base emulsion to make the pH of the emulsion = 11; after pre-curing for 6 hours, an acid (citric acid) is added for neutralization to obtain a self-condensing "soft-hard" segment structure silicone emulsion; the self-condensing silicone emulsion can be packaged and stored in a sealed container.

[0172] Tests have shown that this self-condensing silicone emulsion has excellent waterproofing properties, exhibits self-condensing curing characteristics at room temperature / heat, requires no metal catalyst during curing, is environmentally friendly and easy to use, and has good adhesion to a variety of substrates, meeting various construction conditions.

[0173] Example 4

[0174] (1) Accurate weighing:

[0175] 250g of linear polydimethylsiloxane, with the following structural formula:

[0176]

[0177] Where n is 500, m is 300, R is hydroxyl, and R3 is methyl;

[0178] 100g of silicone resin, wherein the unit chain segment of the silicone resin is:

[0179] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0180] Wherein, R' is methyl, R” is aminopropyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 0.8%;

[0181] 100g of functional additives, with the following structural formula:

[0182]

[0183] Wherein, R1 is methyl, R2 is a phenyl-substituted alkane group with 2 carbon atoms, and p+q is 75, where p is 70 and q is 5;

[0184] Mix the above three components to form a homogeneous organosilicon mixture.

[0185] (2) Mix 20g of surfactant fatty alcohol polyoxyethylene ether AEO-9 and 10g of isomeric tridecyl alcohol polyoxyethylene ether 1307 with the organosilicon mixture obtained in step (1) until homogeneous. Under strong stirring (1300r / min), gradually add 520g of water to form a basic emulsion.

[0186] (3) The base emulsion obtained in step (2) is homogenized by a high-pressure homogenizer at a pressure of 600 bar; then, an alkali (potassium hydroxide) is added to the homogenized base emulsion to make the pH of the emulsion = 10; after pre-curing for 8 hours, an acid (hydrochloric acid) is added for neutralization to obtain a self-condensing "soft-hard" segment structure silicone emulsion; the self-condensing silicone emulsion can be packaged and stored in a sealed container.

[0187] Tests have shown that this self-condensing silicone emulsion has excellent waterproofing properties, exhibits self-condensing curing characteristics at room temperature / heat, requires no metal catalyst during curing, is environmentally friendly and easy to use, and has good adhesion to a variety of substrates, meeting various construction conditions.

[0188] Example 5

[0189] (1) Accurate weighing:

[0190] 400g of linear polydimethylsiloxane, with the following structural formula:

[0191]

[0192] Where n is 500, m is 350, R is hydroxyl, and R3 is an alkane with 16 carbon atoms;

[0193] 100g of silicone resin, wherein the unit chain segment of the silicone resin is:

[0194] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0195] Wherein, R' is methyl, R” is aminoethyl, (R'+R”) / Si is 1.5, and the hydroxyl content is 3%;

[0196] 100g of functional additives, with the following structural formula:

[0197]

[0198] Wherein, R1 is a hydroxyl group, R2 is a 2-carbon alkane group substituted with a mercapto group, and p+q is 70, where p is 60 and q is 10;

[0199] Mix the above three components to form a homogeneous organosilicon mixture.

[0200] (2) Mix 40g of surfactant fatty alcohol polyoxyethylene ether AEO-7, 20g of isomeric tridecyl alcohol polyoxyethylene ether 1310, 10g of dodecylbenzenesulfonic acid triethanolamine salt with the organosilicon mixture obtained in step (1) until homogeneous. Under strong stirring (1800r / min), gradually add 400g of water to form a basic emulsion.

[0201] (3) The base emulsion obtained in step (2) is homogenized by a high-pressure homogenizer at a pressure of 800 bar; then, an alkali (potassium hydroxide) is added to the homogenized base emulsion to make the pH of the emulsion = 10; after pre-curing for 5 hours, an acid (hydrochloric acid) is added for neutralization to obtain a self-condensing "soft-hard" segment structure silicone emulsion; the self-condensing silicone emulsion can be packaged and stored in a sealed container.

[0202] Tests have shown that this self-condensing silicone emulsion has excellent waterproofing properties, exhibits self-condensing curing characteristics at room temperature / heat, requires no metal catalyst during curing, is environmentally friendly and easy to use, and has good adhesion to a variety of substrates, meeting various construction conditions.

[0203] Comparative Example 1

[0204] The preparation method provided in Example 1 is used, except that the unit chain segment of the silicone resin in this comparative example is:

[0205] [R'3SiO 0.5 ] M [R”SiO 1.5 ] T [SiO2] Q ;

[0206] Wherein: R' and R” are both methyl groups, (R'+R”) / Si is 1.1, and the hydroxyl content is 4%; all other conditions are the same as in Example 1.

[0207] Comparative Example 2

[0208] The preparation method provided in Example 1 was used, except that the homogenization pressure of the emulsion in this comparative example was 200 bar; all other conditions were the same as in Example 1.

[0209] Comparative Example 3

[0210] The preparation method provided in Example 1 was used, except that the homogenization pressure of the emulsion in this comparative example was 1000 bar; all other conditions were the same as in Example 1.

[0211] Performance testing: The various physical and chemical properties of the samples were tested according to the JC / T902-2002 industry standard for silicone waterproofing for building surfaces, as shown in Table 1 below.

[0212] Table 1

[0213]

[0214]

[0215] Performance testing: The particle size of the emulsion was tested using a laser particle size analyzer, and the data are shown in Table 2 below.

[0216] Table 2

[0217]

[0218] In summary, under the relevant industry standards, the silicone emulsions prepared by this invention are significantly superior to the standard indicators (water absorption rate ≤20%). At the same time, the emulsions of this invention have excellent waterproof effect, self-condensation curing characteristics at room temperature / heat, no need for the use of metal catalysts during the curing process, are environmentally friendly and easy to use, have good adhesion to a variety of substrates, and can meet a variety of construction conditions.

[0219] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-condensation type silicone emulsion prepared from the following raw materials: linear polydimethylsiloxane 250-400 parts by weight; silicone resin 50-100 parts by weight; functional additive 50-100 parts by weight; surfactant 30-70 parts by weight; water 330-620 parts by weight; the linear polydimethylsiloxane has the following structural formula: ； wherein n is 280-1500, m is 200-800, R is methoxy, ethoxy or hydroxyl, and R3 is methyl, vinyl, phenyl, trifluoropropyl or alkane with 8-16 carbon atoms; the silicone resin has the following unit link: [R'3SiO 0.5 ] M [R''SiO 1.5 ] T [SiO2] Q ; wherein R' and R" are independently selected from phenyl, methyl, ethyl, aminoethyl or aminopropyl, (R' + R") / Si is 1.1-1.5, and the hydroxyl content is 0.5%-4%; the functional additive has the following structural formula: ； wherein R1 is methyl, methoxy, ethoxy or hydroxyl, R2 is phenyl or alkyl with 2-10 carbon atoms substituted by aromatic group, amino group, ureido group, methacryloyloxy group, mercapto group or epoxy group, and p + q is 15-80, wherein p is 10-70 and q is 5-20; the preparation method of the self-condensation type silicone emulsion comprises the following steps: a) mixing the linear polydimethylsiloxane, the silicone resin and the functional additive to form a uniform silicone mixture; b) mixing the silicone mixture obtained in step a) with the surfactant and water to form a base emulsion; c) homogenizing the base emulsion obtained in step b), and then sequentially adjusting the pH, pre-curing and neutralizing to obtain the self-condensation type silicone emulsion; the homogenization pressure is 400-800 bar; the self-condensation type silicone emulsion does not require the use of metal catalysts during the curing process.

2. The self-condensation type silicone emulsion according to claim 1, characterized by the surfactant is selected from one or more of non-ionic surfactants, anionic surfactants and cationic surfactants; wherein the non-ionic surfactant is selected from one or more of the following: the Span series, the Tween series, polyethylene glycol fatty acid ester, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, isomeric alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and paraffin emulsifier; the cationic surfactant is selected from one or more of the following: fatty amine salt, ethanolamine salt and polyethylene polyamine salt; and the anionic surfactant is selected from one or more of the following: anionic polyacrylamide, fatty acid salt, sulfonate, sulfate salt and phosphate salt.

3. A preparation method of the self-condensation type silicone emulsion according to any one of claims 1-2, comprising the following steps: a) mixing the linear polydimethylsiloxane, the silicone resin and the functional additive to form a uniform silicone mixture; b) mixing the silicone mixture obtained in step a) with the surfactant and water to form a base emulsion; c) homogenizing the base emulsion obtained in step b), and then sequentially adjusting the pH, pre-curing and neutralizing to obtain the self-condensation type silicone emulsion; the homogenization pressure is 400-800 bar. The self-condensation type silicone emulsion can be cured into a film by self-condensation reaction at room temperature without catalyst as water evaporates.

4. The production method according to claim 3, characterized by, The step b) is specifically: The surfactant is mixed with the silicone mixture obtained in step a) under stirring, and then water is added dropwise under strong stirring to form a base emulsion.

5. The preparation method according to claim 4, characterized in that, The rotating speed of the strong stirring is 1000 r / min-2000 r / min.

6. The preparation method according to claim 3, characterized in that, The homogenization treatment in step c) is performed by using a high-pressure homogenizer.

7. The preparation method according to claim 3, characterized in that, The process of sequentially adjusting pH, pre-curing and neutralization treatment in step c) is specifically: The pH of the base emulsion after the homogenization treatment is adjusted to be greater than or equal to 10 by adding a base, and then the base emulsion is pre-cured for 5-8 hours, and then an acid is added for neutralization to obtain the self-condensation type silicone emulsion. Or, The pH of the base emulsion after the homogenization treatment is adjusted to be less than or equal to 4 by adding an acid, and then the base emulsion is pre-cured for 5-8 hours, and then a base is added for neutralization to obtain the self-condensation type silicone emulsion.

8. The preparation method according to claim 7, characterized in that, The base is selected from inorganic bases and / or organic bases; wherein the inorganic base is selected from sodium hydroxide and / or potassium hydroxide, and the organic base is selected from triethylamine and / or diethylamine. The acid is selected from inorganic acids and / or organic acids; wherein the inorganic acid is selected from hydrochloric acid and / or sulfuric acid, and the organic acid is selected from citric acid and / or acetic acid.

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