RU2184125C1 - Aqueous heteropolymeric dispersion for preparing covers and method of its preparing - Google Patents

Abstract

FIELD: polymers, chemical technology. SUBSTANCE: invention relates to dispersions used for preparing covers, in part, transparent, shock-resistant covers on glass articles, for example, light-technical articles, display screens, glass fibers and so on. Particles of an aqueous heteropolymeric dispersion used for covers making comprise copolymers including links of acrylic monomers and consist of a core, intermediate envelope and external envelope. The core copolymer is a copolymer of (meth)acrylic ester or a mixture of (meth)acrylic esters, ethylene-unsaturated monomer comprising two or three bonds C=C and, possibly, ethylene-unsaturated monomer comprising carboxyl-groups and it shows a vitrification point less 7 C. Copolymer of an intermediate envelope is a copolymer of methacrylic ester or a mixture of methacrylic esters, ethylene- unsaturated monomer comprising two or three bonds C=C and, possibly, ethylene-unsaturated monomer comprising carboxyl-groups and showing a vitrification point 50-85 C. Copolymer of an external envelope is a copolymer of methacrylic ester or a mixture of methacrylic esters and ethylene-unsaturated monomer comprising carboxyl-groups with a vitrification point 25-70 C. Mass ratio of core copolymers, intermediate and external envelopes is in the range = (60-75) : (7.5-20) : (10-22.5), respectively, and mean size of particles dispersion is 50-220 nm. An aqueous heteropolymeric dispersion for covers making is prepared by multistage emulsion copolymerization involving successive stages of emulsion copolymerization of core monomers and envelope monomers at temperature less 100 C in the presence of a water-soluble free-radical initiating agent and an anionic surface-active substance. The stage of core copolymer preparing is carried out for two steps. At the first step emulsion copolymerization is carried out in the presence of an initiating agent and an anionic surface-active substance in a one-time loading 10- 30% of the total amount of the core monomer mixture. In the second step the remained part of core monomers or emulsion of this part of core monomer stabilized with an anionic surface-active substance is dosed to the formed primer latex. The stage of preparing a copolymer of intermediate envelope is carried out by continuous dosing a monomeric mixture forming an intermediate envelope to a core copolymer dispersion. Before onset of this stage an aqueous solution of initiating agent is added to a core copolymer dispersion. The preparation of copolymer of an intermediate envelope can be made for two steps being compositions of a monomeric mixture are different in indicated steps. The stage of preparing the external envelope copolymer is carried out by emulsion copolymerization of monomers forming an external envelope in the presence of a dispersion obtained in a previous stage. The prepared heteropolymeric aqueous dispersions provide the transparency, hardness, nonsticking and shock-resistance of covers. EFFECT: simplified technology, improved and valuable properties of dispersion, improved method of making. 7 cl, 2 tbl, 1 dwg

Description

 The invention relates to aqueous heteropolymer dispersions used for the manufacture of coatings, in particular transparent, impact-resistant coatings on glass products. Such dispersions can be used in the preparation of shatterproof glasses, protective coatings on glass lighting products, on display screens, on glass fibers, etc. The water base of polymer dispersions creates favorable technological and environmental conditions for the formation of polymer coatings on glass products by spraying, dipping and other methods.

 A number of aqueous polymer dispersions or compositions based on them are known that are suitable for producing coatings on glass.

 Known aqueous composition based on elastomeric latex, plasticizer and small amounts of other ingredients (US patent 4263362, 32 In 7/00, 1981). As an elastomeric latex, the composition comprises a latex of polybutadiene or a carboxylated styrene-butadiene copolymer. Coatings obtained on the basis of these polymers are sticky and not sufficiently hard due to the fact that the polymers contained in them, especially in the presence of plasticizers, have a low glass transition temperature.

 A known composition comprising a latex based on a copolymer of butadiene, unsaturated carboxylic acid and a vinyl compound (US patent 3919440, 32 32 17/10, 1975). Coatings on glass products obtained on the basis of this composition have insufficient heat and light resistance, as well as low strength, since they partially break down even with a thickness of 145-250 microns.

 Aqueous polymer compositions are also known, including latexes of polybutadiene or copolymers based on styrene, butadiene and vinylpyridine (US patents 4060658, B 32 V 9/00, D 02 G 3/00, 1977; 3853605, B 32 V 17/06, B 32 B 17/10, C 03 C 25/02, 1974). The composition of these compositions also includes resorcinol formaldehyde resins, which makes it possible to count on the formation of more durable and hard coatings. However, the high content in the polymers and copolymers of butadiene carbon-carbon double bonds reduces the chemical resistance and weather resistance of the resulting coatings.

 Polymeric compositions based on acrylic monomers are more consistent with the requirements for coatings on glass products. For example, aqueous dispersions of thermosetting compositions are known, including acrylic copolymers and epoxy resins (US patent 3970628, C 08 L 63/10, 1976), which could be used for coatings on glass, however, information about their strength and transparency is not available.

 Compositions are known including acrylic latex, in particular acrylonitrile-ethyl acrylate copolymer latex, a crosslinking agent and a thickening agent (US Pat. Nos. 3,944,100, B 65 D 23/00, C 08 L 61/20, 1976, and 4098934, B 32 V 17/10, 1978). These compositions are used to coat glass products, but high temperatures are required to cure them, as are the compositions of US Pat. No. 3,970,628.

Also known are aqueous acrylic polymer dispersions used for the manufacture of coatings on fiberglass (US patent 5827612, D 02 G 3/00, 1998), free from this drawback. The process of producing polymer coatings based on these dispersions consists of the following stages:
1. Application of the first acrylic polymer dispersion using known methods on the surface of glass fibers.

 2. Drying the obtained first polymer layer at room or elevated temperature.

 3. Application of the second polymer layer, for example, by dipping the product into a second acrylic polymer dispersion, which differs in composition from the first.

 4. Drying of the second polymer layer.

 The disadvantage of these compositions is the multi-stage production of coatings based on them. It would be preferable to use aqueous polymer compositions, which can provide a polymer coating in one cycle "coating - drying."

Known aqueous polymer composition, which allows to obtain a shatterproof coating on glass with improved mechanical characteristics, based on acrylic polymer dispersions, for example Нycar 2679, into which a 1% solution of Polyhall 295 polyacrylamide was introduced, probably to thicken the dispersion, which is necessary to control the thickness coatings (German application 2424329, B 65 D 23/08, C 03 from 17/32, 1974). The composition forms a coating on glass products, having improved mechanical properties and ensuring the absence of fragments during the destruction of the product; such coatings and products in which they are used are hereinafter referred to as shatterproof. Coatings based on this composition were obtained by dipping glass products into a polymer dispersion, followed by drying at room temperature and final curing of the coating at 232 ^{° C.} for 4 minutes. The impact resistance of the coating was evaluated by breaking under certain conditions with the determination of the number of fragments into which the product disintegrates upon destruction. Depending on the type, the glass product without a polymer coating was destroyed with the formation of 120-155 fragments (table 1 from the description of the invention to the German application 2424329). When coating a glass product, the number of fragments during destruction decreased depending on the thickness of the coating to 18-43 (examples F, G, H in the above table 1). Thus, glass products with the specified acrylic polymer coating cannot be considered shatterproof. Impact resistance improves and the product becomes shatterproof if, before applying the polymer acrylic coating, the glass surface is first treated with a wetting agent - tetraisopropyl titanate, and then with SC-100 polyethylene emulsion (Example K, Table 1).

 The disadvantage of the described composition is the multi-stage process of obtaining coatings based on it. To obtain shatterproof glass products using this composition, it is necessary to carry out at least three successive operations, "application-drying."

 Coatings based on the various latex systems described above are typically single-phase polymer systems that may contain solid inclusions of cured thermosetting resins. To obtain impact-resistant coatings, the use of microheterogeneous polymer systems is more preferable.

 Closest to the claimed technical essence is the known aqueous heteropolymer dispersion for the manufacture of coatings, the particles of which contain copolymers including units of acrylic monomers, and consist of a core and one outer shell (US patent 4009317, 32 V 17/02, C 08 L 23/02, 1977). An aqueous polymer composition prepared using the specified dispersion was used for a single treatment of glass fibers. The use of acrylic type monomers at the stages of preparing core and shell polymers suggests that coatings based on these dispersions can be optically transparent, and if a large amount of shell polymer is present, it can also be impact resistant. However, in US patent 4009317 there are no indicators characterizing the transparency and impact resistance of the resulting coatings. The main disadvantage of coatings made on the basis of aqueous polymer compositions obtained according to this patent is the low glass transition temperature of the polymer shell and the presence in the composition of various additives (paraffin, wax, cationic grease, etc.). Both of these factors, increasing the stickiness of the coating, prevent the formation of coatings with sufficient surface hardness.

 Known methods for producing aqueous heteropolymer dispersions for the manufacture of coatings, the particles of which contain copolymers including acrylic monomer units, by emulsion copolymerization of these monomers in several stages in the presence of an anionic surfactant and a water-soluble free radical initiator (US patent 4469825, C 08 F 265/10, 1984; 5157084, C 08 F 265/02, 1992).

Closest to the proposed technical essence is a known method for producing an aqueous heteropolymer dispersion for the manufacture of coatings used for processing glass fibers, the particles of which contain copolymers including acrylic monomer units, and consist of a core and one outer shell by two-stage emulsion copolymerization, which includes sequential stages emulsion copolymerization of core monomers and the outer shell at a temperature less than 100 ^o C in the presence of water-soluble vobodnoradikalnogo initiator and anionic surfactants (U.S. Patent 4,009,317, in 32 V 17/02, C 08 L 23/02, 1977). The core particles of this dispersion were obtained by emulsion polymerization of alkyl methacrylates, usually methyl methacrylate. Then, in the presence of the resulting dispersion, seed emulsion polymerization of monomers, usually alkyl acrylates, was carried out with the formation of a polymer shell of particles having a glass transition temperature of 10 ^{° C.} or lower. The polymer dispersion thus obtained is not used directly to obtain coatings, but is mixed with a pre-prepared emulsion of certain additives (paraffin, wax, etc.), so that the process of obtaining the final coating composition includes at least three processes, namely: obtaining a heteropolymer dispersion obtaining an emulsion and mixing the two components.

 The technical result, the achievement of which the present invention provides, is to simplify the technology for producing impact-resistant polymer coatings on glass by using an aqueous polymer dispersion of a certain composition obtained by the claimed method. The invention provides shockproof shatterproof coatings in one application-drying cycle.

The specified technical result is achieved due to the fact that to obtain coatings, in particular transparent impact-resistant coatings on glass, an aqueous heteropolymer dispersion is proposed for the manufacture of coatings, the particles of which contain copolymers including units of acrylic monomers and consist of a core and at least one outer shell characterized in that its particles consist of a core, an intermediate shell and an outer shell, the copolymer of the core is a copolymer of (meth) acrylic ester or a mixture of (meth) acrylic esters, ethylene an unsaturated monomer containing two or three C = C bonds, and possibly an ethylenically unsaturated monomer containing carboxyl groups and has a glass transition temperature of less than 7 ^° C, the intermediate shell copolymer is a copolymer of methacrylic ester or a mixture of methacrylic esters, an ethylenically unsaturated monomer containing two or three C = C bond, and optionally, an ethylenically unsaturated monomer containing a carboxyl group and has a glass transition temperature of 50-85 ^o C, and the outer shell copolymer is a copolymer of methacrylic ester yl mixture of methacrylic esters and the ethylenically unsaturated monomer containing a carboxyl group and has a glass transition temperature of 25-70 ^o C, wherein the weight ratio of the core copolymer intermediate and outer shells is in the range (60-75) :( 7,5-20): (10 -22.5), and the particle diameter of the dispersion is 50-220 nm.

In preparing a heteropolymer dispersion, it is preferable to use
- as (meth) acrylic ester, a compound of the general formula CH ₂ = C (R) -C (O) OR ₁ , where R = H or CH ₃ , R ₁ -C ₁ -C ₁₈ alkyl, for example, selected from the group including methyl, ethyl, n-butyl, isobutyl, n-octyl, 2-ethylhexyl, dodecyl acrylate, methyl, ethyl methacrylate;
- as an ethylenically unsaturated monomer containing two or three bonds C = C, di (meth) acrylate of ethylene, diethylene or triethylene glycol, allyl (meth) acrylate, trimethylol propane trimethacrylate, triallyl cyanurate, divinylbenzene;
- as an ethylenically unsaturated monomer containing carboxyl groups, acrylic acid or its α- (C ₁ -C ₅ alkyl) -substituted, maleic, fumaric, itaconic acids or their mono (C ₁ -C ₄ alkyl) esters.

 Preferably, the copolymers included in the dispersion particles can be characterized as follows: the core copolymer is a copolymer of a (meth) acrylic ester or a mixture of (meth) acrylic esters, di (meth) acrylic ester and, optionally, (meth) acrylic acid, contains 0, 1-0.5 wt.% Units of di (methacrylic) ether and 0-5.0 wt.% Units of (meth) acrylic acid, the intermediate shell copolymer is a copolymer of methacrylic ester or a mixture of methacrylic esters, di (meth) acrylic ether and, possibly (meth) acrylic acid, contains 0.5-2.0 wt.% units di (meth) acrylic ether and 0-7.5 wt. % units of (meth) acrylic acid, and the copolymer of the outer shell is a copolymer of methacrylic ester or a mixture of methacrylic esters and (meth) acrylic acid and contains 7.5-10.0 wt.% units of (meth) acrylic acid.

To obtain the specified dispersion, a method for producing an aqueous heteropolymer dispersion for the manufacture of coatings is proposed, the particles of which contain copolymers including acrylic monomer units and consist of a core and at least one outer shell by means of multi-stage emulsion copolymerization, which includes sequential stages of emulsion copolymerization of core monomers and monomers membranes at a temperature less than 100 ^o C in the presence of water soluble free radical initiator and anionic surfactant substance (surfactant), characterized in that the stage of obtaining the core copolymer is carried out in two stages, at the first of which emulsion copolymerization is carried out in the presence of initiator and anionic surfactant at a single charge of 10-30% of the total amount of the monomer mixture of the core, and at the second stage the remaining part of the core monomers or the emulsion of this part of the core monomers stabilized by an anionic surfactant is dosed into the resulting seed latex; the stage of preparing the intermediate shell copolymer is carried out by continuous dosing of the monomer of the mixture forming the intermediate shell into the dispersion of the copolymer of the core, and before the start of this stage, an aqueous solution of the initiator is introduced into the dispersion of the copolymer of the core, the step of obtaining the copolymer of the outer shell is carried out by emulsion copolymerization of the monomers forming the outer shell in the presence of the dispersion obtained in the previous stages, moreover, the loading of the monomers of the outer shell is carried out either in two equal portions, while introducing into the dispersion aqueous solutions of the initiator and anionic surfactant before loading the monomer the outer shell, either by continuous dosing in the form of an aqueous emulsion of monomers stabilized by an anionic surfactant, while dosing an aqueous solution of the initiator, which may contain dissolved anionic surfactant, and after completion of the process, an aqueous solution of ammonia, a volatile aliphatic amine, or a water-soluble hydroxide or salts of a divalent metal in an amount of 0.1-1.0 mol per 1 mol of monomer units containing carboxyl groups.

According to the proposed method, the stage of obtaining the core copolymer is carried out in two stages. First, in the aqueous phase containing the dissolved initiator and anionic surfactant, 10-30% of the monomer mixture of the total amount of the monomer mixture of the core is loaded, the polymerization process is carried out and seed latex is obtained. At the second stage, the remaining part of the monomer mixture is started to be dosed into the seed latex. The specified part of the monomer mixture can be dosed in the form of a pre-prepared emulsion stabilized by an anionic surfactant. To obtain a core copolymer, it is preferable to use an alkyl acrylate or a mixture of alkyl acrylate and alkyl methacrylate, and the mass ratio of the latter is chosen so that the glass transition temperature of the core copolymer is not higher than 7 ^° , preferably from -25 to -54 ^° C.

The stage of obtaining the intermediate shell copolymer can be carried out with continuous dosing of the monomer mixture into the dispersion of the core copolymer. Before dosing of the monomer mixture forming the intermediate shell copolymer, an aqueous initiator solution is introduced into the dispersion of the core copolymer. At this stage, a mixture of two alkyl methacrylates with different substituents can be used as alkyl methacrylate, but their mass ratio is chosen so that the copolymer of the intermediate shell has a glass transition temperature in the range of 50-85 ^o C, preferably 50-70 ^o C.

 Obtaining a copolymer of the intermediate shell can also be carried out in two stages, at each of which the composition of the monomer mixture is different, while in the second stage, the monomer mixture and the aqueous solution of the initiator and anionic surfactant are simultaneously dosed.

The stage of obtaining the copolymer of the outer shell is carried out by emulsion copolymerization of the monomers of the outer shell in the presence of a dispersion obtained in the previous step and containing particles consisting of a core and an intermediate shell. The loading of monomers can be carried out in two equal portions. In this case, before loading the monomers forming the copolymer of the outer shell, aqueous solutions of initiator and anionic surfactant are introduced. It is preferable to dose the monomeric mixture of the outer shell continuously in the form of an aqueous emulsion stabilized by an anionic surfactant, while an aqueous solution containing the dissolved initiator and anionic surfactant can be dosed at the same time. As the alkyl methacrylate at this stage, one monomer or a mixture of two alkyl methacrylates with different alkyl substituents can be used, but their mass ratio is chosen so that the outer shell copolymer has a glass transition temperature in the range of 25-70 ^o C, preferably 30-60 ^o C.

 After completion of the polymerization process, an aqueous solution of ammonia, a volatile aliphatic amine, such as trimethylamine, diethylamine, triethylamine, diethylethanolamine, or a water-soluble hydroxide or divalent metal salt, for example, barium, zinc or its barium hydroxide, is introduced into the resulting aqueous heteropolymer dispersion; ammonia complex, in an amount of 0.1-1.0 mol per 1 mol of units used in the process of ethylenically unsaturated monomer containing carboxyl groups. The introduction of these agents leads to at least partial neutralization of the carboxyl groups of said unsaturated monomer. In addition, divalent metal compounds not only neutralize carboxyl groups, but also act as crosslinking agents, increasing the surface hardness of the coating. When using divalent metal compounds, non-ionic surfactants (for example, ethoxylated aliphatic alcohol) are introduced before loading in the amount of 0.5-1.0% by weight of the dispersion, based on the dry matter content in it.

 The copolymerization at each stage of the process is carried out almost until the monomers are completely converted into a copolymer, i.e. the composition of the resulting copolymers corresponds to the composition of the monomer mixture. This is achieved by the selected concentrations of initiator and anionic surfactant, the duration of the process, and the additional exposure of the polymer dispersion after each stage at the reaction temperature after the loading of the components for 30 minutes. It is preferable to use a water-soluble initiator and anionic surfactant, respectively, in an amount of 0.3-0.4% and 0.2-2.0% by weight of the monomers in the preparation of a core copolymer, 0.3-0.9% and 0-0, 5% by weight of monomers upon receipt of the intermediate shell copolymer, 0.3-1.2% and 0.3-3.0% by weight of monomers upon receipt of the outer shell copolymer.

 Known water-soluble compounds, for example, ammonium, sodium, potassium persulfates, are used as initiators of emulsion copolymerization.

Sodium C ₁₂ -C ₁₈ -alkyl sulfonates, for example, Elfan OS-46 (a mixture of C ₁₄ -C ₁₆ alkyls from Akzo Nobel), or C ₁₀ -C ₁₈ -alkylaryl sulfonates or C ₁₂ -C ₁₈ - are preferably used as anionic surfactants. sodium alkyl sulfates.

 Upon receipt of a heteropolymer aqueous dispersion, it is very important to comply with the proposed ratios of the amounts of monomers loaded at various stages of the process. When deviating from the above ratios, coatings obtained using a heteropolymer aqueous dispersion are either sticky or do not have the necessary impact resistance.

Obtained by the present invention, aqueous heteropolymer dispersions are characterized by the following properties:
- dry residue 36-50 wt.%,
- particle diameter of 50-220 nm,
- pH 7-8.4 when using ammonia and 2.2-2.3 when using zinc acetate,
- viscosity on the viscometer VZ-4 30-53 s.

 Coatings made using the obtained dispersions are characterized by high transparency (integrated light transmission of 91-92%), hardness and impact resistance. Coated glass products are truly shatterproof, since when they break, all glass fragments remain in the polymer shell.

The properties of the obtained aqueous heteropolymer dispersions and coatings based on them were determined by the following methods:
1. The pH of the dispersions was determined on a universal ionomer EV-74.

 2. The particle size of the dispersion was determined by the well-known method of light scattering by diluted dispersion, based on the logarithmic dependence of optical density on wavelength (V.I. Klenin et al. Characteristic functions of light scattering of dispersed systems. Saratov: Saratov University Press, 1977, 177 pp. .).

 3. The solids content in the dispersion was determined by the gravimetric method according to GOST 25709-83.

4. The adhesion of the copolymers was determined by peeling the latex film from the glass plate at an angle of 180 ^o .

5. The hardness of the coatings was determined by the method of damping the oscillations of the pendulum according to GOST 5233-89 (pendulum weight 120 ± 1 g, pendulum length 500 ± 1 mm, stainless steel ball diameter 7.938 mm). Relative hardness N was calculated by the equation
H = t / t ₁ ,
where t is the decay time from a deviation of 5 ^o to a deviation of 2 ^o on a coating deposited on a glass base, t ₁ is the decay time from a deviation of 5 ^o to a deviation of 2 ^o on a glass base without coating.

6. The nominal viscosity of the dispersions was determined viscometrically using a VZ-4 viscometer according to GOST 8420-74 (funnel volume 120 ± 1 cm ³ , orifice diameter 4 mm).

 7. The light transmittance was determined using a photometer in accordance with GOST 15875-80.

 8. The stickiness of the coating was determined by a quality test. A sheet of standard writing paper was applied to a coating with a thickness of at least 100 μm applied to a flat glass surface and pressed to the coating with a force of 0.005 MPa. A coating is considered not sticky if there is no trace of paper adhering to the coating.

где q_n - массовая доля мономера n,
Т_ст..n - температура стеклования полимера n.9. The glass transition temperature T _article copolymers calculated according to Fox equation

where q _n is the mass fraction of monomer n,
T _st..n - the glass transition temperature of the polymer n.

 10. The minimum film-forming temperature (MTP) was determined as the boundary of the transition between the continuous and discrete parts of the film during the formation of a dispersed coating on the horizontal surface of the device with a linear temperature gradient.

где А - энергия, затрачиваемая на разрушение образца (Дж),
А₀ - энергия, затрачиваемая на извлечение подвижного зажима (Дж),
b - ширина образца (мм),
h - толщина образца (мм).11. The shock tension of the films was determined by a specially developed technique. To test the impact resistance of the films, a shock pendulum was used in accordance with DIN 53448. Samples of films 0.3-0.8 mm thick were tested. The sample shown in the drawing, 0.3-0.8 mm thick, was fixed on the basis of the instrument measuring the impact resistance with two clamps, one of which is rigidly fixed to the bed, and the other is movable. The movable clamp has a protrusion in the transverse direction, on which a U-shaped hammer strikes. The movable clamp moves under the action of a shock impulse from the hammer, and the sample is destroyed. Sample clamps are of great importance. If the sample is loosely fixed by clamps, it begins to move, and friction energy is lost. Another source of loss is the work done by removing the movable clamp with sample residue. This energy is determined by blank experiments. The tensile strength Q _{t was} determined in kJ / m ² according to the formula

where A is the energy spent on the destruction of the sample (J),
And ₀ is the energy spent on the extraction of the movable clamp (J),
b is the width of the sample (mm),
h is the thickness of the sample (mm).

12. The impact resistance of glass products with a coating based on the proposed dispersion was determined by the method of destruction of thick-walled glass tubes (length 300 mm, diameter 36 mm, wall thickness 1.5 mm) with a coating of a thickness of at least 100 μm when they fall from a height of 1.5 m on a massive concrete base. The coating was considered to pass the test, if there were no breaks and delamination of the polymer shell during the destruction of the glass, as well as the deformation of the glass product. All glass fragments remained in the polymer shell. Coatings on glass tubes were prepared by dipping them into a dispersion, followed by drying at 90 ^{° C.} for 2 hours.

 The invention is illustrated by the following examples 1-13, which illustrate the composition of the proposed dispersion and method for its preparation. In all examples, the process is described in three stages to obtain dispersions, the particles of which contain a core, an intermediate and an outer shell.

Example 1
Stage 1
45 g of deionized water, in which 0.9 g of anionic surfactant Elfan OS-46 (C ₁₄ -C ₁₆ sodium alkyl sulfonate; product of Akzo Nobel), is dissolved in nitrogen reactor, are loaded with nitrogen, heated to 80 ^o C and 22.17 g of n-butyl acrylate (BA) and 0.07 g of ethylene glycol dimethacrylate (DMEG) are charged, stirred for 5 minutes, a solution of 0.13 g of ammonium persulfate (PA) dissolved in 10 g of water is added, and the seed process is carried out copolymerization for 30 minutes

 An emulsion of monomers is prepared separately: BA 66.5 g, DMEG 0.20 g, Elfan OS-46 (37% solution) 2.71 g, water 28 g.

A solution of 0.13 g of PA in 5 g of water is added to the obtained seed dispersion, stirred for 5 minutes and the emulsion of monomers is dispensed at a rate of 0.812 g / min. The total dosing time is 120 minutes After dosing, the resulting dispersion is maintained at 80 ^{° C.} for 30 minutes.

Stage 2
A solution of 0.16 g of PA in 3 g of water is loaded into the dispersion obtained in stage 1, it is stirred for 5 minutes and a mixture of monomers consisting of 5.32 g of methyl methacrylate (MMA), 11.44 g of n-butyl methacrylate (BMA) is started to be dosed. 0.88 g of methacrylic acid (MAA) and 0.09 g of DMEG, at a rate of 0.296 g / min. Total dosing time 60 minutes After dosing, the resulting dispersion is maintained at 80 ^{° C.} for 30 minutes.

Stage 3
An emulsion of monomers is prepared separately: MMA 1.33 g, BMA 23.34 g, MAK 2.0 g, Elfan OS-46 (37% solution) 1.3 g, water 12 g.

A solution of 0.05 g of PA in 9 g of water is loaded into the dispersion obtained in stage 2, it is stirred for 5 minutes and the emulsion of monomers is dispensed at a rate of 0.222 g / min. The total dosing time of 180 minutes 90 minutes after the start of dosing, a solution of 0.05 g of PA in 9 g of water is loaded into the dispersion. After dosing, the monomer emulsions were dispersed at 80 ^{° C.} for 30 minutes. The content of residual monomers in the dispersion: BA, MAK, DMEG, MMA - absence; BMA - 0.01 wt.%. The dispersion is cooled and neutralized by 1.61 g of a 24.5% aqueous solution of ammonia.

 The total process time is 500 minutes

 The compositions of the downloads for this and subsequent examples are shown in table 1, the compositions and properties of dispersions and coatings based on them are shown in table 2.

Example 2
Stage 1
Carried out as in example 1.

Stage 2
A solution of 0.09 g of PA in 9.9 g of water is loaded into the dispersion obtained in stage 1, which is used as a seed dispersion, stirred for 5 min, and a mixture of monomers consisting of 5.60 g of MMA, 3.61 g of BMA, 0 , 76 g of MAA and 0.20 g of DMEG at a rate of 0.1695 g / min. Total dosing time 60 minutes After the dosing of the monomer mixture, the dispersion was maintained at 80 ^{° C.} for 30 minutes.

Stage 3
A monomer emulsion and an aqueous phase are prepared separately. The composition of the emulsion: MMA 14.26 g, BMA 13.33 g, MAK 2.24 g, Elfan OS-46 (37% solution) 1.21 g, water 10 g. Composition of the aqueous phase: PA 0.09 g, Elfan OS-46 (37% solution) 0.20 g, water 12.2 g.

In the dispersion obtained in stage 2, used as a seed, at the same time, the emulsion of monomers is started to be dosed at a rate of 0.1710 g / min and the aqueous phase at a rate of 0.0520 g / min. Total dosing time 240 min. After the dosing of the monomers and the aqueous phase is completed, the dispersion is maintained at 80 ^{° C.} for 30 minutes. After this, the dispersion is cooled and neutralized 1.81 g of a 24.5% aqueous solution of ammonia.

 The total process time is 555 minutes

Example 3
Differs from example 1 in the recipe for loading the components in the stages of the process. The temperature of the process is 90 ^o C. The total process time is 470 minutes

Example 4
It differs from Example 1 in the recipe for loading the components according to the stages of the process and in that zinc acetate in the form of a 0.05 M aqueous solution is used instead of ammonia solution. To enhance stabilization of the dispersion, OS-20 nonionic surfactant (C ₁₆ -C ₁₈ ethoxylated aliphatic alcohol) is introduced in the form of a 5% aqueous solution. The total duration of the process is 500 minutes

Example 5
It differs from example 2 in the recipe for loading the components according to the stages of the process and in that zinc acetate in the form of a 0.05 M aqueous solution is used instead of ammonia solution. To enhance stabilization of the dispersion, OS-20 nonionic surfactant is introduced in the form of a 5% aqueous solution. The total duration of the process 535 minutes

Example 6
Differs from example 1 in the recipe for loading the components in the stages of the process. The total duration of the process is 500 minutes

Example 7
It differs from Example 2 in the recipe for loading the components according to the stages of the process and in that instead of DMEG, ethylene glycol diacrylic ester (DAEG) is used. The total duration of the process 540 minutes

Example 8
It differs from Example 2 in the recipe for loading the components according to the stages of the process and in that acrylic acid (AK) is used instead of methacrylic acid. The total duration of the process is 500 minutes

Example 9
Stage 1
Carried out as in example 1.

Stage 2
A solution of 0.16 g of PA in 5 g of water is loaded into the dispersion obtained in stage 1, it is stirred for 5 minutes and the mixture of monomers consisting of 5.32 g of MMA, 11.44 g of BMA, 0.88 g of MAA and 0.09 is started to be dosed. g DMEG at a rate of 0.296 g / min. Total dosing time 60 minutes Separately, the aqueous phase is prepared: PA 0.08 g, Elfan OS-46 (37% solution) 0.12 g, water - 3 g.

At the same time, the aqueous phase is dosed into the dispersion at a rate of 0.053 g / min and a mixture of monomers consisting of 4.47 g MMA, 3.98 g BMA, 0.45 g MAA and 0.04 g DMEG at a rate of 0.149 g / min. Total dosing time 60 minutes After dosing, the dispersion is maintained at 80 ^o With 30 minutes

Stage 3
Carried out as in example 2.

 The total duration of the process is 620 minutes.

Example 10
It differs from Example 1 in the recipe for loading the components according to the stages of the process and in that methyl acrylate (MA) is used instead of BA.

 The total duration of the process is 500 minutes

Example 11
It differs from Example 1 in the recipe for loading the components according to the process steps, the conditions for stage 1. After the seed copolymerization is carried out, the monomer mixture is dosed in the obtained seed dispersion instead of the emulsion of monomers at a rate of 0.556 g / min and that 2-ethylhexyl acrylate (EGA) is used instead of BA, instead of DMEG, allyl methacrylate (AMA).

Example 12
It differs from Example 1 in that instead of MAK, monobutyl maleate is used, and sodium dodecylbenzenesulfonate as a surfactant at all stages.

Example 13
Stage 1
45 g of deionized water, in which 0.12 g of Elfan OS-46 is dissolved, are purged with nitrogen, heated to 80 ^° C and loaded with 8.87 g of BA and 0.03 g of DMEG, stirred for 5 minutes a solution of 0.13 g of PA dissolved in 10 g of water is added, and a seed copolymerization process is carried out for 30 minutes.

 An emulsion of monomers is prepared separately: BA 79.8 g, DMEG 0.24 g, Elfan OS-46 0.70 g, water 28 g.

A solution of 0.17 g of PA in 5 g of water is added to the obtained seed dispersion, stirred for 5 minutes and the emulsion of monomers is dispensed at a rate of 0.812 g / min. Total dosing time 135 minutes After dosing, the resulting dispersion is maintained at 80 ^{° C.} for 30 minutes.

 The remaining stages of the process are carried out as in example 1.

 The total process time is 515 minutes.

 As can be seen from the data in the examples, heteropolymer aqueous dispersions obtained, unlike the prototype, using simplified technology, provide transparent, hard, non-sticky and impact-resistant coatings.

Claims (7)

1. An aqueous heteropolymer dispersion for the manufacture of coatings, the particles of which contain copolymers including acrylic monomer units and consist of a core and at least one outer shell, characterized in that its particles consist of a core, an intermediate shell and an outer shell, a core copolymer is a copolymer of a (meth) acrylic ester or a mixture of (meth) acrylic esters, an ethylenically unsaturated monomer containing two or three C = C bonds, and possibly an ethylenically unsaturated monomer containing carboxyl groups, and has a tempera uru glass transition of less than 7 ^o C, the intermediate shell copolymer is a copolymer of a methacrylic ester or a mixture of methacrylic esters, ethylenically unsaturated monomer containing two or three C = C bond, and optionally, an ethylenically unsaturated monomer containing a carboxyl group and has a glass transition temperature of 50-85 ^o C, and the outer shell copolymer is a copolymer of a methacrylic ester or a mixture of methacrylic esters and the ethylenically unsaturated monomer containing a carboxyl group and has a glass transition temperature of 25-70 ^o C, with a weight ratio of the nucleus copolymers, intermediate and outer shells is in the range (60-75): (7,5-20) (10-22,5), and the average diameter of the dispersion particles is 50-220 nm. 2. An aqueous heteropolymer dispersion according to claim 1, characterized in that as the (meth) acrylic ester, a compound selected from the group consisting of compounds of the general formula CH ₂ = C (R) -C (O) OR ₁ , where R = H or CH ₃ , R ₁ - C ₁ -C ₁₈ alkyl, di (meth) acrylate of ethylene, diethylene or triethylene glycol, allyl (meth) acrylate, trimethylolpropane trimethacrylate are used as ethylenically unsaturated monomer containing two or three C = C bonds , triallyl cyanurate, divinylbenzene, and as an ethylenically unsaturated monomer containing carboxyl groups, acryl is used lovic acid or its α- (C ₁ -C ₅ alkyl) -substituted, maleic, fumaric, itaconic acids or their mono (C ₁ -C ₄ alkyl) esters.  3. The aqueous heteropolymer dispersion according to claim 2, characterized in that the copolymer of the core is a copolymer of (meth) acrylic ester or a mixture of (meth) acrylic esters, di (meth) acrylic ester and, optionally, (meth) acrylic acid, contains 0, 1-0.5 wt. % units of di (meth) acrylic ester and 0-5.0 wt. % units of (meth) acrylic acid, the intermediate shell copolymer is a copolymer of methacrylic ester or a mixture of methacrylic esters, di (meth) acrylic ester and, possibly, (meth) acrylic acid, contains 0.5-2.0 wt. % units of di (meth) acrylic ester and 0-7.5 wt. % units of (meth) acrylic acid, and the copolymer of the outer shell is a copolymer of methacrylic ester or a mixture of methacrylic esters and (meth) acrylic acid and contains 7.5-10.0 wt. % units of (meth) acrylic acid. 4. A method of obtaining an aqueous heteropolymer dispersion for the manufacture of coatings, the particles of which contain copolymers including acrylic monomer units, and consist of a core and at least one outer shell, by multistage emulsion copolymerization, comprising sequential stages of emulsion copolymerization of core monomers and shell monomers at a temperature less than 100 ^o C in the presence of water soluble free radical initiator and anionic surfactant (surfactant), characterized in that the article The preparation of the core copolymer is carried out in two stages, in the first of which emulsion copolymerization is carried out in the presence of an initiator and anionic surfactant with a simultaneous loading of 10-30% of the total amount of the monomeric mixture of the core, and in the second stage, the remaining portion of the core monomers is metered into or the emulsion of this part of the core monomers stabilized by an anionic surfactant, the stage of preparation of the copolymer of the intermediate shell is carried out by continuous dosing of the monomer mixture forming the intermediate shell cu, into the dispersion of the core copolymer, and before the start of this stage, an aqueous solution of the initiator is introduced into the dispersion of the core copolymer, the step of obtaining the outer shell copolymer is carried out by emulsion copolymerization of the monomers forming the outer shell in the presence of the dispersion obtained in the previous step, and the loading of the outer shell monomers carried out either in two equal portions, while introducing into the dispersion aqueous solutions of the initiator and anionic surfactant before loading the monomers of the outer shell, or by continuous an aqueous emulsion of monomers stabilized by an anionic surfactant, while dosing an aqueous initiator solution that may contain a dissolved anionic surfactant, the mixture of monomers at least in one of the stages comprising an ethylenically unsaturated monomer containing carboxyl groups, and after completion of the process, the resulting the dispersion is injected with an aqueous solution of ammonia, a volatile aliphatic amine, or a water-soluble hydroxide or divalent metal salt in an amount of 0.1-1.0 mol per 1 mol of ethylenically unsaturated units Nogo monomer containing a carboxyl group.  5. A method of producing an aqueous heteropolymer dispersion according to claim 4, characterized in that before the introduction of a hydroxide or a salt of a divalent metal, a nonionic surfactant is added to the dispersion in an amount of 0.5-1.0% by weight of the copolymer.  6. A method of obtaining an aqueous heteropolymer dispersion according to paragraphs. 4 and 5, characterized in that the preparation of the copolymer of the intermediate shell is carried out in two stages, and the compositions of the monomer mixture at these stages differ.  7. A method of obtaining an aqueous heteropolymer dispersion according to paragraphs. 4-6, characterized in that the water-soluble initiator and the anionic surfactant are introduced into the reaction mixture, respectively, in an amount of 0.3-0.4 and 0.2-2.0% by weight of the monomers upon receipt of the core copolymer, 0.3- 0.9 and 0-0.5% by weight of monomers upon receipt of the intermediate shell copolymer, 0.3-1.2 and 0.3-3.0% by weight of monomers upon receipt of the outer shell copolymer.

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