Vinyl acetate-ethylene copolymer and dispersion and coating composition containing same

Abstract

The present invention relates to a vinyl acetate-ethylene copolymer (VAE), and a dispersion and a coating composition comprising the same, the VAE copolymer having a relative molecular weight distribution curve map obtained by determination with a gel permeation chromatography, the map comprising: a map area ML having a relative molecular weight of 10,000 to 100,000, and a map area MH having a relative molecular weight of 100,000 to 2,500,000, the map area ML having a relative molecular weight of 10,000 to 100,000, and the map area MH having a relative molecular weight of 2,000,000 to 2,000,000, the map area MH having a relative molecular weight of 2,000,000 to 2,000,000, and the map area MH having a relative molecular weight of 2,000,000 to 2,000,000, and the map area MH having a relative molecular weight of 10,000 to 2,000,000. Wherein the ratio of MH to ML is from 2.33 to 4.71. The VAE copolymer disclosed by the invention has excellent freeze-thaw resistance.

Description

Technical Field

[0001] The present application relates to a vinyl acetate-ethylene copolymer, and in particular to a vinyl acetate-ethylene copolymer and a dispersion and a coating composition containing the same, but is not limited thereto. Background Art

[0002] Vinyl acetate-ethylene (VAE) copolymers are formed by copolymerizing vinyl acetate and ethylene. They are easily emulsified and dispersed in water to form stable aqueous dispersions. These VAE copolymer emulsions offer excellent performance and are widely used.

[0003] This VAE copolymer is commonly used in applications such as construction, packaging, toys, home furnishings, textiles, and electronic components. Specifically, due to its free-flowing nature, VAE copolymer emulsions offer excellent convenience and reliability during handling and storage. Furthermore, since they can be mixed and stirred with powdered materials (such as cement, sand, and lightweight aggregate), they can be used as a binder in construction materials and adhesives. Summary of the Invention

[0004] Vinyl acetate-ethylene (VAE) copolymers (hereinafter referred to as VAE copolymers) are typically stored in low-temperature environments during transportation in high-latitude regions with cold winters (average temperatures ranging from 0°C to -10°C). However, the inventors have discovered that when the temperature of conventional VAE copolymers is raised from low temperatures to room temperature, they often form lumps, flocculation, or separation, affecting the performance of the VAE copolymers and, in turn, negatively impacting their subsequent processability and applicability.

[0005] To solve the above technical problems, the present application provides a vinyl acetate-ethylene (VAE) copolymer, which is measured by gel permeation chromatography to obtain a relative molecular weight distribution curve, comprising: a graph area M with a relative molecular weight of 10,000 to 100,000 L , and a chromatographic area M with a relative molecular weight of 100,001 to 2,500,000 H Among them, M H / M L 2.33 to 4.71.

[0006] In one or more embodiments, the VAE copolymer has a bimodal molecular weight distribution profile, and the molecular weight distribution profile is plotted from a first profile by a first and a second data conversion, wherein the first profile has a Y-axis of signal intensity corresponding to an elution time of 0 to 25 minutes as measured by a gel permeation chromatograph, and an X-axis of elution time; wherein the first data conversion divides each of the signal intensity by a maximum signal intensity (Ymax) in the first profile to obtain a signal intensity ratio (Yx), and converts the Y-axis of the first profile to the signal intensity ratio; wherein the second data conversion obtains a relationship between a relative molecular weight and an elution time based on a calibration curve prepared from a standard, and converts the X-axis of the first profile to the relative molecular weight.

[0007] In one or more embodiments, the VAE copolymer has a weight average relative molecular weight (Mw) / number average relative molecular weight (Mn) of 1.59 to 2.20.

[0008] In one or more embodiments, the VAE copolymer has a Mw / Mn of 1.64 to 2.18.

[0009] In one or more embodiments, the VAE copolymer has a molecule located in the area M L with a Mn of 44,000 to 74,000.

[0010] In one or more embodiments, the VAE copolymer has a molecule located in the area M H with a Mw / Mn less than or equal to 1.55.

[0011] Another aspect of the present application provides a dispersion comprising: the VAE copolymer as described above, and a dispersion medium.

[0012] In one or more embodiments, the dispersion system is in an emulsion form.

[0013] In one or more embodiments, the residue derived from vinyl acetate (VAM) is less than or equal to 0.1000 wt% based on the total weight of the dispersion.

[0014] In one or more embodiments, the dispersion medium comprises polyvinyl alcohol, water, hydroxyethyl cellulose (HEC), an emulsifier, a dispersant, or a combination thereof.

[0015] Another aspect of the present application provides a coating composition comprising the dispersion as described above.

[0016] In one or more embodiments, the coating composition further comprises a powder component, and the powder component is dispersed in the dispersion; or the powder component is independently packaged outside the dispersion.

[0017] The VAE copolymers of this application are suitable for a variety of applications, particularly dispersions and coating compositions. The advantages of the VAE copolymers of this application are that, with one cycle consisting of raising the temperature from low temperature to room temperature, the VAE copolymers undergo multiple cycles without forming lumps, flocculation, or separation, exhibiting excellent freeze-thaw resistance.

[0018] More specifically, the inventors of the present application have found that controlling the VAE copolymer to be located in the absorption spectrum area M H By controlling the Mw / Mn ratio within a specific range, the freeze-thaw resistance of the VAE copolymer can be further improved over time. DETAILED DESCRIPTION

[0019] In order to make the description of this application more detailed and complete, the following is an illustrative description of the implementation methods and specific examples of this application, but this is not the only form of implementing or using the specific examples of this application. The various embodiments disclosed below can be combined or replaced with each other where beneficial, and other embodiments can be added to one embodiment without further recording or explanation. In the following description, many specific details will be described in detail so that the reader can fully understand the following embodiments; however, the embodiments of the contents disclosed in this application can be practiced without such specific details. In addition, in this specification and the scope of the attached patent application, unless the context otherwise indicates, "one" and "the" can also be interpreted as multiple.

[0020] Although the numerical ranges and parameters used to define the present invention are approximate, the numerical values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inherently contains inevitably standard deviations resulting from individual testing methods.

[0021] Although a series of operations or steps are used below to illustrate the method disclosed herein, the order in which these operations or steps are shown should not be construed as limiting the present application. For example, certain operations or steps may be performed in a different order or simultaneously with other steps. Furthermore, it is not necessary to perform all operations, steps, or features to achieve the embodiments of the present application. Furthermore, each operation or step described herein may include several sub-steps or actions.

[0022] Unless otherwise specified, "room temperature" as used herein refers to a temperature of 25° C.; and "normal pressure" as used herein refers to a pressure of 1 atmosphere (atm).

[0023] [VAE copolymer]

[0024] The present application provides a VAE copolymer having a relative molecular weight distribution curve, comprising: a relative molecular weight of 10,000 to 100,000 M L , and a relative molecular weight of 100,001 to 2,500,000 M H ; wherein M H / M L is 2.33 to 4.71. The present inventors have found that when the M H / M L is within a certain range, the VAE copolymer has excellent freeze-thaw resistance, thereby improving its subsequent processability and applicability. Specifically, the VAE copolymer of the present application has a relative molecular weight distribution curve measured by a gel permeation chromatograph, comprising a relative molecular weight of 10,000 to 100,000 M L , and a relative molecular weight of 100,001 to 2,500,000 M H , wherein M H / M L is 2.33 to 4.71, for example but not limited to 2.33, 2.34, 2.35, 2.36, 2.37, 2.38, 2.39, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3.65, 3.70, 3.75, 3.80, 3.85, 3.90, 3.95, 4.00, 4.05, 4.10, 4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, 4.50, 4.55, 4.60, 4.65, 4.70, or 4.71, or any value within the range formed by any two of the above values. In at least one embodiment of the present application, preferably the M H / M L is 2.33, 2.70, 2.76, 2.80, 2.86, 3.73, 3.78, 3.95, 4.00, 4.22, or 4.71.

[0025] According to at least one embodiment of the present application, the relative molecular weight distribution profile is bimodal, and the relative molecular weight distribution profile is plotted from a first profile by first and second data conversions, wherein the first profile has a Y-axis of signal intensity corresponding to elution time of 0 to 25 minutes measured by a gel permeation chromatograph, and an X-axis of elution time in minutes; wherein the first data conversion divides each of the signal intensity by a maximum signal intensity (Ymax) in the first profile to obtain a signal intensity ratio (Yx), and converts the Y-axis of the first profile to the signal intensity ratio (i.e., Yx); wherein the second data conversion obtains a relationship between relative molecular weight and elution time based on a calibration curve made from a standard, and converts the X-axis of the first profile to relative molecular weight. According to at least one embodiment of the present application, the first peak of the bimodal distribution is between relative molecular weight of 10,000 to 100,000, and the second peak is between relative molecular weight of 100,001 to 2,500,000, and the second peak is higher than the first peak.

[0026] According to at least one embodiment of the present application, the VAE copolymer has a weight average relative molecular weight (hereinafter referred to as Mw) / number average relative molecular weight (hereinafter referred to as Mn) of 1.59 to 2.20, such as but not limited to 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.70, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.80, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.90, 1.91, 1.92, 1.93, 1.94, 1.95, 1.96, 1.97, 1.98, 1.99, 2.00, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.10, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, or 2.20, or any value within a range formed by any two of the above values. In at least one embodiment of the present application, preferably, the VAE copolymer has a Mw / Mn of 1.64 to 2.18, such as but not limited to 1.64, 1.67, 1.77, 1.78, 1.85, 1.89, 1.90, 1.91, 1.92, 2.13, or 2.18, or any value within a range formed by any two of the above values.

[0027] According to at least one embodiment of the present application, the VAE copolymer has a weight average relative molecular weight (hereinafter referred to as Mw) / number average relative molecular weight (hereinafter referred to as Mn) of 1.59 to 2.20, such as but not limited to 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.70, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.80, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.90, 1.91, 1.92, 1.93, 1.94, 1.95, 1.96, 1.97, 1.98, 1.99, 2.00, 2.01, 2.02, 2.03, 2.04, 2.05, 2.06, 2.07, 2.08, 2.09, 2.10, 2.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.18, 2.19, or 2.20, or any value within a range formed by any two of the above values. In at least one embodiment of the present application, preferably, the VAE copolymer has a Mw / Mn of 1.64 to 2.18, such as but not limited to 1.64, 1.67, 1.77, 1.78, 1.85, 1.89, 1.90, 1.91, 1.92, 2.13, or 2.18, or any value within a range formed by any two of the above values. L44,000 to 74,000, such as, but not limited to, 44,000, 45,000, 46,000, 47,000, 48,000, 49,000, 50,000, 51,000, 52,000, 53,000, 54,000, 55,000, 56,000, 57,000, 58,000, 59,000, 60,000, 61,000, 62,000, 63,000, 64,000, 65,000, 66,000, 67,000, 68,000, 69,000, 70,000, 71,000, 72,000, 73,000, 74,000, or any value within the range bounded by any two of the foregoing values. In at least one embodiment of the application, preferably the polymer molecules having a relative molecular weight of 10,000 to 100,000 in the VAE copolymer have an Mn of 44,526, 45,495, 45,522, 46,022, 47,373, 47,542, 47,761, 47,812, 48,823, 48,929, 53,213, or 73,233.

[0028] Without being bound by theory, the inventors of the present application believe that the VAE copolymer can further be enabled to achieve excellent resistance to freeze-thaw cycling when the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is within a particular range. According to at least one embodiment of the present application, the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is less than or equal to 1.55, such as, but not limited to, less than or equal to 1.55, less than or equal to 1.54, less than or equal to 1.53, or less than or equal to 1.52. According to at least one embodiment of the present application, preferably the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is 1.30 to 1.55. According to at least one embodiment of the present application, more preferably the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is 1.35 to 1.53. According to at least one embodiment of the present application, even more preferably the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is 1.39 to 1.52. According to at least one embodiment of the present application, the Mw / Mn of the polymer molecules having a relative molecular weight of 100,001 to 2,500,000 in the VAE copolymer is, for example, but not limited to, 1.39, 1.40, 1.42, 1.48, 1.49, 1.50, 1.51, or 1.52.

[0029] [Method for manufacturing dispersion containing VAE copolymer]

[0030] The VAE copolymer of the present application can be obtained by copolymerizing vinyl acetate and ethylene. Generally, the method for copolymerizing vinyl acetate and ethylene roughly comprises a premixing step, a polymerization reaction step, a defoaming step, and a post-adding step as needed. For example, the VAE copolymer dispersion of the present application can be prepared by a method comprising the following steps: in the premixing step, dissolving polyvinyl alcohol in water at a temperature of not less than 80°C, and, as needed, adding dropwise a catalyst (such as copper sulfate, ethylenediaminetetraacetic acid, or a combination thereof), an emulsifier, a pH buffer, a chelating agent, or a combination thereof, and placing in a reactor to mix at a temperature of 25 to 60°C to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight (hereinafter referred to as the polyvinyl alcohol weight ratio) is 0.20 to 2.00, specifically, for example: 0.20, 0.40, 0.60, 0.80, 1.00, 1.20, 1.40, 1.60, 1.80, 2.00, or a range between any two of the above values; on the other hand, the polyvinyl alcohol with a large relative molecular weight described herein specifically refers to polyvinyl alcohol with a relative molecular weight of 110,000 to 160,000, and the polyvinyl alcohol with a small relative molecular weight described herein specifically refers to polyvinyl alcohol with a relative molecular weight of 15,000 to 50,000. According to some embodiments of the present application, preferably, the polyvinyl alcohol weight ratio is 0.25 to 1.96, specifically, for example: 0.25, 0.67, 1.66, 1.71, 1.77, 1.91, or 1.96.

[0031] In the polymerization reaction step, the temperature of the premixing reaction solution is raised to 50 to 80°C, and ethylene gas is introduced to raise the pressure to 40 to 70 kgf / cm 2 ; then, a small amount of initiator is added dropwise, and a small amount of vinyl acetate monomer is added dropwise to perform a preliminary reaction for 0.5 hours; then, as needed, a reducing agent is added dropwise, and the pressure is raised by 5 kgf / cm 2; maintaining the ventilation of ethylene, and performing the polymerization reaction for a total reaction time of 300 to 520 minutes, specifically for example: 300 minutes, 320 minutes, 340 minutes, 360 minutes, 380 minutes, 400 minutes, 420 minutes, 440 minutes, 460 minutes, 480 minutes, 500 minutes, 520 minutes, or a range between any two of the aforementioned values. Specifically, during the polymerization reaction, the remaining initiator, and the vinyl acetate monomer are added dropwise, and after the addition is completed, the ventilation of ethylene is stopped, and then the temperature and pressure are naturally restored to room temperature and normal pressure, to obtain a defoaming product, and the defoaming product comprises a protective colloid polyvinyl alcohol. Among them, the addition time of the initiator is 100 to 200 minutes, specifically for example: 100 minutes, 120 minutes, 140 minutes, 160 minutes, 180 minutes, 200 minutes, or a range between any two of the aforementioned values; and the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 3.90 to 5.10, specifically for example: 3.90, 3.91, 3.92, 3.93, 3.94, 3.95, 3.96, 3.97, 3.98, 3.99, 4.00, 4.01, 4.02, 4.03, 4.04, 4.05, 4.06, 4.07, 4.08, 4.09, 4.10, 4.11, 4.12, 4.13, 4.14, 4.15, 4.16, 4.17, 4.18, 4.19, 4.20, 4.21, 4.22, 4.23, 4.24, 4.25, 4.26, 4.27, 4.28, 4.29, 4.30, 4.31, 4.32, 4.33, 4.34, 4.35, 4.36, 4.37, 4.38, 4.39, 4.40, 4.41, 4.42, 4.43, 4.44, 4.45, 4.46, 4.47, 4.48, 4.49, 4.50, 4.51, 4.52, 4.53, 4.54, 4.55, 4.56, 4.57, 4.58, 4.59, 4.60, 4.61, 4.62, 4.63, 4.64, 4.65, 4.66, 4.67, 4.68, 4.69, 4.70, 4.71, 4.72, 4.73, 4.74, 4.75, 4.76, 4.77, 4.78, 4.79, 4.80, 4.81, 4.82, 4.83, 4.84, 4.85, 4.86, 4.87, 4.88, 4.89, 4.90, 4.91, 4.92, 4.93, 4.94, 4.95, 4.96, 4.97, 4.98, 4.99, 5.00, 5.01, 5.02, 5.03, 5.04, 5.05, 5.06, 5.07, 5.08, 5.09, 5.10, or a range between any two of the aforementioned values.According to some embodiments of the present application, preferably, the total reaction time of the polymerization reaction is 327 to 518 minutes, specifically for example: 327 minutes, 389 minutes, 443 minutes, 446 minutes, 450 minutes, 486 minutes, 490 minutes, 500 minutes, 503 minutes, 512 minutes, or 518 minutes. According to other embodiments of the present application, preferably, the duration of the initiator addition is 101 to 175 minutes, specifically for example: 101 minutes, 108 minutes, 109 minutes, 115 minutes, 120 minutes, 126 minutes, 128 minutes, 136 minutes, 145 minutes, 167 minutes, or 175 minutes.

[0032] In the defoaming step, the un-defoamed product is cooled to 55°C and placed in a degassing tank for defoaming. A defoaming agent is added to the degassing tank, stirred and left to stand for 30 minutes, and then cooled to 20°C to obtain a dispersion comprising a VAE copolymer. The dispersion comprising a VAE copolymer comprises a VAE copolymer, and a dispersion matrix; wherein the VAE copolymer is dispersed in the dispersion matrix.

[0033] According to some embodiments of the present application, the emulsifier includes, but is not limited to, an anionic emulsifier, a cationic emulsifier, or a non-ionic emulsifier. Examples of the anionic emulsifier include, but are not limited to, C8 to C18 alkyl sulfate, alkyl or alkyl aryl ether sulfate having C8 to C18 hydrophobic group and up to 40 units of ethylene oxide or propylene oxide, C8 to C18 alkyl or alkyl aryl sulfonate, or ester or half-ester of sulfosuccinic acid with monohydric alcohol or alkyl phenol. Examples of the non-ionic surfactant include, but are not limited to, alkyl or alkyl aryl polyglycol ether having 8 to 40 units of ethylene oxide. Specific examples of the non-ionic surfactant include, but are not limited to, C6 to C12 alkyl phenol ethoxylate and ethylene oxide / propylene oxide block copolymer. The amount of the emulsifier can be 0.1 wt.% to 5.0 wt.% based on the total weight of the VAE copolymer, for example, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%, 0.6 wt.%, 0.7 wt.%, 0.8 wt.%, 0.9 wt.%, 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, or 5.0 wt.%, or within a range between any two of the aforementioned values.

[0034] According to some embodiments of the present application, the chelating agent includes, but is not limited to, ethylenediaminetetraacetic acid (EDTA) and its salts, diethylenetriaminepentaacetic acid (DTPA) and its salts, N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) and its salts, nitrilotriacetic acid (NTA) and its salts, 2,3-dimercaptosuccinic acid (DMSA) and its salts, N,N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA), trisodium dicarboxymethylalaninate (MGDA), ethanol diglycinic acid disodium salt (EDG), glucoheptonic sodium salt, or a combination thereof. The amount of the chelating agent can be in a range of 1 ppm to 10000 ppm, for example, 1 ppm, 10 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 1000 ppm, 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, 6000 ppm, 7000 ppm, 8000 ppm, 9000 ppm, 10000 ppm, or a range between any two of the aforementioned values, based on the total weight of the VAE copolymer.

[0035] According to some embodiments of the present application, the initiator includes, but is not limited to, hydrogen peroxide, tertiary butyl peroxide (e.g., tertiary butyl hydroperoxide), potassium persulfate, sodium persulfate, ammonium persulfate, potassium peroxodisulfate, benzoyl peroxide, lauryl peroxide, zinc peroxide, tertiary butyl pentanoate, cumyl hydroperoxide, azobis isobutyronitrile, or a combination thereof. The initiator can be used in an amount of 0.01 wt.% to 8.00 wt.%, based on the total weight of the VAE copolymer, such as 0.01 wt.%, 0.05 wt.%, 0.10 wt.%, 0.50 wt.%, 1.00 wt.%, 2.00 wt.%, 3.00 wt.%, 4.00 wt.%, 5.00 wt.%, 6.00 wt.%, 7.00 wt.%, 8.00 wt.%, or within a range between any two of the foregoing values.

[0036] According to some embodiments of the present application, the reducing agent includes, but is not limited to, sulfites of alkali metals or ammonium, bisulfites (e.g., sodium sulfite), derivatives of sulfoxylates (e.g., zinc formaldehyde sulfoxylate or sodium formaldehyde sulfoxylate), sulfinic acids and salts thereof (e.g., 2-hydroxy-2-sulfinatoacetic acid, 2-hydroxy-2-sulfinatoacetic acid disodium salt, 2-hydroxy-2-sulfinatoacetic acid zinc salt, or 2-hydroxy-2-sulfinatopropionic acid disodium salt), ascorbic acid and salts thereof (e.g., sodium ascorbate), erythorbic acid and salts thereof (e.g., sodium erythorbate or tartaric acid), or a combination thereof. Preferred embodiments of the reducing agent can be sulfinic acids and salts thereof, ascorbic acid and salts thereof, erythorbic acid and salts thereof, or a combination thereof. The reducing agent can be used in an amount of 0.01 wt.% to 2.00 wt.%, based on the total weight of the VAE copolymer, such as 0.01 wt.%, 0.02 wt.%, 0.03 wt.%, 0.04 wt.%, 0.05 wt.%, 0.06 wt.%, 0.07 wt.%, 0.08 wt.%, 0.09 wt.%, 0.10 wt.%, 0.20 wt.%, 0.30 wt.%, 0.40 wt.%, 0.50 wt.%, 0.60 wt.%, 0.70 wt.%, 0.80 wt.%, 0.90 wt.%, 1.00 wt.%, 1.10 wt.%, 1.20 wt.%, 1.30 wt.%, 1.40 wt.%, 1.50 wt.%, 1.60 wt.%, 1.70 wt.%, 1.80 wt.%, 1.90 wt.%, 2.00 wt.%, or within a range between any two of the foregoing values.

[0037] According to at least one embodiment of the present application, the defoaming agent is, for example but not limited to, a mineral oil-based defoaming agent, a higher alcohol-based defoaming agent, a polyether-based defoaming agent, an organic-based defoaming agent, an organosiloxane defoaming agent, a polyether defoaming agent, a silicon and ether grafted defoaming agent, an amine-containing defoaming agent, an imine-containing defoaming agent, an amide-containing defoaming agent, or a combination thereof; preferably, the defoaming agent is an organic-based defoaming agent, such as TEGO Antifoam 2290 (purchased from Evonik).

[0038] In addition, the method of manufacturing the dispersion comprising the VAE copolymer can further comprise a post-adding step. In the post-adding step, a post-adding additive can be added to the VAE copolymer as needed without violating the intended effects of the present application.

[0039] According to at least one embodiment of the present application, the post-adding additive is, for example but not limited to, a lignin sulfonate-based water reducing agent, a naphthalene-based water reducing agent, a melamine-based water reducing agent, an aminosulfonate-based water reducing agent, a fatty acid-based water reducing agent, a polycarboxylate-based water reducing agent, or a combination thereof. According to another embodiment of the present application, the amount of the post-adding additive can be 0 to 5 wt.%, for example but not limited to 0 wt.%, 0.1 wt.%, 1.0 wt.%, 2.0 wt.%, 3.0 wt.%, 4.0 wt.%, 5.0 wt.%, or a range between any two of the aforementioned values, based on the total weight of the dispersion comprising the VAE copolymer.

[0040] According to at least one embodiment of the present application, the dispersion comprising the VAE copolymer can further comprise a mildewcide, and examples of the mildewcide include but are not limited to 1,2-benzisothiazolin-3-one (BIT), 2-methyl-4-isothiazolin-3-one (MIT) based mildewcide, isothiazolinone, LXE fungicide, or a combination thereof.

[0041] According to at least one embodiment of the present application, the dispersion comprising the VAE copolymer can further comprise a dispersant, and examples of the dispersant include but are not limited to a polycarboxylic compound, a polyester compound, a polycarboxylate compound, an unsaturated polyamide compound, a polycarboxylic alkyl salt compound, a polyacrylic compound, a polyethyleneimine compound, a polyurethane compound, or a combination thereof.

[0042] According to at least one embodiment of the present application, the dispersion exhibits an emulsion form. According to some other embodiments of the present application, the dispersion medium comprises, for example but not limited to, polyvinyl alcohol, water, hydroxyethyl cellulose (HEC), emulsifier, dispersant, or a combination thereof. According to some other embodiments of the present application, the particle size distribution D50 of the particles formed by the VAE copolymer and the dispersion medium is in the range of 0.80 to 1.00 microns, for example but not limited to 0.80 microns, 0.81 microns, 0.82 microns, 0.83 microns, 0.84 microns, 0.85 microns, 0.86 microns, 0.87 microns, 0.88 microns, 0.89 microns, 0.90 microns, 0.91 microns, 0.92 microns, 0.93 microns, 0.94 microns, 0.95 microns, 0.96 microns, 0.97 microns, 0.98 microns, 0.99 microns, or 1.00 microns, or any value within the range between any two of the aforementioned values.

[0043] According to at least one embodiment of the present application, the content of residual unreacted vinyl acetate (VAM) in the dispersion (hereinafter referred to as the VAM content) is less than or equal to 0.1000 wt.%, based on the total weight of the dispersion; specifically, for example, less than or equal to 0.1000 wt.%, less than or equal to 0.0900 wt.%, less than or equal to 0.0800 wt.%, less than or equal to 0.0700 wt.%, less than or equal to 0.0600 wt.%, less than or equal to 0.0500 wt.%, less than or equal to 0.0400 wt.%, less than or equal to 0.0300 wt.%, or less than or equal to 0.0200 wt.%; preferably, the VAM content is less than or equal to 0.0990 wt.%; more preferably, less than or equal to 0.0995 wt.%. According to at least one preferred embodiment of the present application, the VAM content is 0.0111 wt.%, 0.0198 wt.%, 0.0400 wt.%, 0.0451 wt.%, 0.0524 wt.%, 0.0626 wt.%, 0.0754 wt.%, 0.0954 wt.%, 0.0967 wt.%, or 0.0982 wt.%, based on the total weight of the dispersion.

[0044] The dispersion can further include an additive, such as, but not limited to, a plasticizer, without violating the objects of the present application. According to some embodiments of the present application, the plasticizer is, for example, but not limited to, di-n-butyl phthalate (DBP), di-iso-butyl phthalate (DIBP), di-(2-ethylhexyl) phthalate (DEHP), di-iso-nonyl phthalate (DINP), di-iso-decyl phthalate (DIDP), butyl phenyl phthalate (BBP), di-iso-octyl phthalate (DIOP), di-n-octyl phthalate (DNOP), di-ethyl phthalate (DEP), di-n-hexyl phthalate (DNHP), or a combination thereof.

[0045] [Coating composition and method of manufacturing the same]

[0046] Another aspect of the present application provides a coating composition comprising the dispersion as described above. According to at least one embodiment of the present application, the coating composition further comprises a powder component, and the powder component is dispersed in the dispersion; or the powder component is separately packaged outside the dispersion. According to some other embodiments of the present application, the powder component is, for example, but not limited to, Portland cement, quartz sand, calcium carbonate, talc, calcium chloride, gypsum, or a combination thereof. According to some preferred embodiments of the present application, the Portland cement is white cement, black cement, or a combination thereof. The method of manufacturing the coating composition of the present application is not particularly limited, and one skilled in the art can select a suitable manufacturing method based on the disclosure of the present application.

[0047] Embodiments

[0048] In the following, the present application will be further described in detail with specific embodiments. However, it should be understood that these specific embodiments are only used to help one to more easily understand the present application, and are not used to limit the scope of the present application.

[0049] 1. Preparation of a dispersion comprising a VAE copolymer

[0050] Herein, the present application provides a non-limiting method of manufacturing a dispersion comprising a VAE copolymer. According to the method disclosed below, a non-limiting dispersion comprising a VAE copolymer (Examples 1 to 12) and a comparative dispersion comprising a VAE copolymer (Comparative Examples 1 to 3) were prepared.

[0051] Example 1: 88 grams of polyvinyl alcohol was dissolved in water at a temperature of 88 °C and put into a reactor to be mixed at a temperature of 25 to 60 °C to obtain a pre-mixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight was 1.91.

[0052] Next, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 Next, a preliminary reaction was performed for 0.5 hours by adding a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer; then, under conditions in which ethylene was being introduced, a polymerization reaction was performed for a total of 446 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was complete, the introduction of ethylene was stopped, and the temperature and pressure were allowed to return naturally to room temperature and normal pressure, thereby obtaining a product that had not been defoamed, wherein the initiator was added for a period of 108 minutes; and wherein the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 4.05, calculated in terms of weight.

[0053] Next, in the defoaming step, the product that had not been defoamed was cooled to 55°C and placed in a degassing tank to be defoamed, a defoaming agent was added to the degassing tank, it was stirred and left to stand for 30 minutes, and then it was cooled to 20°C, thereby obtaining a dispersion containing a VAE copolymer.

[0054] In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and placed in a reactor to be mixed at a temperature of 25 to 60°C, thereby obtaining a pre-mixed reaction solution; wherein the ratio of the weight of polyvinyl alcohol having a large relative molecular weight to the weight of polyvinyl alcohol having a small relative molecular weight in the aforementioned polyvinyl alcohol was 1.71.

[0055] Next, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 Next, a preliminary reaction was performed for 0.5 hours by adding a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer; then, under conditions in which ethylene was being introduced, a polymerization reaction was performed for a total of 518 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was complete, the introduction of ethylene was stopped, and the temperature and pressure were allowed to return naturally to room temperature and normal pressure, thereby obtaining a product that had not been defoamed, wherein the initiator was added for a period of 175 minutes; and wherein the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 4.16, calculated in terms of weight.

[0056] Next, in the defoaming step, the product that had not been defoamed was cooled to 55°C and placed in a degassing tank to be defoamed, a defoaming agent was added to the degassing tank, it was stirred and left to stand for 30 minutes, and then it was cooled to 20°C, thereby obtaining a dispersion containing a VAE copolymer.

[0057] Example 3: In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and mixed in a reactor at a temperature of 25 to 60°C to obtain a pre-mixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight was 1.66.

[0058] Next, in the polymerization reaction step, the temperature of the pre-mixing reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate was added as an initiator and a small amount of vinyl acetate monomer was added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction was carried out for a total reaction time of 503 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was completed, the introduction of ethylene was stopped, and the temperature and pressure were naturally returned to room temperature and normal pressure to obtain a product without defoaming, wherein the length of time for adding the initiator was 167 minutes; wherein, calculated by weight, the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 3.98.

[0059] Next, in the defoaming step, the product without defoaming was cooled to 55°C and placed in a degassing tank for defoaming, a defoaming agent was added in the degassing tank, stirred and left to stand for 30 minutes, and then cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0060] Example 4: In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and mixed in a reactor at a temperature of 25 to 60°C to obtain a pre-mixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight was 1.77.

[0061] Next, in the polymerization reaction step, the temperature of the pre-mixing reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate was added as an initiator and a small amount of vinyl acetate monomer was added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction was carried out for a total reaction time of 503 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was completed, the introduction of ethylene was stopped, and the temperature and pressure were naturally returned to room temperature and normal pressure to obtain a product without defoaming, wherein the length of time for adding the initiator was 167 minutes; wherein, calculated by weight, the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 3.98.

[0062] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank to be defoamed, a defoaming agent is added into the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0063] Example 5: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C and put into a reactor to be mixed at a temperature of 25 to 60°C to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight is 1.91.

[0064] Subsequently, in the polymerization reaction step, the temperature of the premixing reaction solution is raised to 70°C and ethylene gas is introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate is added as an initiator and a small amount of vinyl acetate monomer is added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction is carried out for a total reaction time of 450 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer are added dropwise, and after the addition is completed, the introduction of ethylene is stopped, and the temperature and pressure are naturally returned to room temperature and normal pressure to obtain an un-defoamed product; wherein, the initiator is added for 136 minutes; wherein, the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer is 3.97 by weight.

[0065] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank to be defoamed, a defoaming agent is added into the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0066] Example 6: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C and put into a reactor to be mixed at a temperature of 25 to 60°C to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight is 1.91.

[0067] Subsequently, in the polymerization reaction step, the temperature of the premixing reaction solution is raised to 70°C and ethylene gas is introduced to raise the pressure to 60 kgf / cm 2; then, a preliminary reaction for 0.5 hours is performed by dropping a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer; then, a polymerization reaction for a total of 450 minutes is performed under a condition of maintaining the ventilation of ethylene; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer are dropped, and after the dropping is completed, the ventilation of ethylene is stopped, and the temperature and pressure are naturally returned to room temperature and normal pressure, to obtain an un-defoamed product, wherein the length of time for adding the initiator is 128 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 3.96 in terms of weight.

[0068] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank to perform defoaming, a defoaming agent is added in the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C, to obtain a dispersion containing a VAE copolymer.

[0069] Example 7: In the premixing step, 88 grams of polyvinyl alcohol is dissolved in water at a temperature of 88°C and put into a reactor to be mixed at a temperature of 25 to 60°C, to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight is 1.96.

[0070] Subsequently, in the polymerization reaction step, the temperature of the premixing reaction solution is raised to 70°C, and ethylene gas is introduced to raise the pressure to 60 kgf / cm 2 ; then, a preliminary reaction for 0.5 hours is performed by dropping a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer; then, a polymerization reaction for a total of 443 minutes is performed under a condition of maintaining the ventilation of ethylene; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer are dropped, and after the dropping is completed, the ventilation of ethylene is stopped, and the temperature and pressure are naturally returned to room temperature and normal pressure, to obtain an un-defoamed product, wherein the length of time for adding the initiator is 101 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 4.05 in terms of weight.

[0071] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank to perform defoaming, a defoaming agent is added in the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C, to obtain a dispersion containing a VAE copolymer.

[0072] Example 8: In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and mixed in the reactor at a temperature of 25 to 60°C to obtain a pre-mixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight was 1.77.

[0073] Next, in the polymerization reaction step, the temperature of the pre-mixing reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate was added as an initiator and a small amount of vinyl acetate monomer was added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction was carried out for a total reaction time of 490 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was completed, the introduction of ethylene was stopped, and the temperature and pressure were naturally restored to room temperature and normal pressure to obtain a product without defoaming, wherein the length of time for adding the initiator was 115 minutes; wherein, calculated by weight, the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 4.04.

[0074] Next, in the defoaming step, the product without defoaming was cooled to 55°C and placed in a degassing tank for defoaming, a defoaming agent was added in the degassing tank, stirred and left to stand for 30 minutes, and then cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0075] Example 9: In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and mixed in the reactor at a temperature of 25 to 60°C to obtain a pre-mixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight was 1.77.

[0076] Next, in the polymerization reaction step, the temperature of the pre-mixing reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate was added as an initiator and a small amount of vinyl acetate monomer was added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction was carried out for a total reaction time of 512 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was completed, the introduction of ethylene was stopped, and the temperature and pressure were naturally restored to room temperature and normal pressure to obtain a product without defoaming, wherein the length of time for adding the initiator was 145 minutes; wherein, calculated by weight, the ratio of protective colloid polyvinyl alcohol to vinyl acetate monomer was 4.03.

[0077] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank for defoaming, a defoaming agent is added into the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C to obtain a dispersion containing the VAE copolymer.

[0078] Example 10: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C and put into a reactor for mixing at a temperature of 25 to 60°C to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight is 1.77.

[0079] Subsequently, in the polymerization reaction step, the temperature of the premixing reaction solution is raised to 70°C and ethylene gas is introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate is added as an initiator and a small amount of vinyl acetate monomer is added for a preliminary reaction with a reaction time of 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction is carried out for a total reaction time of 500 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer are added dropwise, and after the addition is completed, the introduction of ethylene is stopped, and the temperature and pressure are naturally restored to room temperature and normal pressure to obtain an un-defoamed product; wherein the initiator is added for 126 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 4.03 by weight.

[0080] Subsequently, in the defoaming step, the un-defoamed product is cooled to 55°C and put into a degassing tank for defoaming, a defoaming agent is added into the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C to obtain a dispersion containing the VAE copolymer.

[0081] Example 11: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C to obtain a polyvinyl alcohol solution, and 0.06 g of copper sulfate as a catalyst, the aforementioned polyvinyl alcohol solution, 25.1 g of an emulsifier (fatty alcohol polyoxyethylene ether, type: 6530, purchased from Rhodia Solvay Group, which is a water solution of tridecyl alcohol ethoxylate containing 30 ethylene oxide units, with an active ingredient of 64 to 66 wt.%, and a hydrophilic-lipophilic balance (HLB) value of 17.2), vinyl acetate monomer (25% of the total amount of vinyl acetate), pH buffer and chelating agent are put into a reactor and mixed at a temperature of 25 to 60°C to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight is 0.67.

[0082] Subsequently, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 55 kgf / cm 2 ; then, a small amount of sodium erythorbate was added as a reducing agent, followed by the addition of a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer, and a preliminary reaction was performed for 0.5 hours; then, the pressure was raised to 60 kgf / cm 2 and a total polymerization reaction was performed for 327 minutes under the condition of maintaining the introduction of ethylene; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer were added dropwise, and after the addition was completed, the introduction of ethylene was stopped, and the temperature and pressure were allowed to return to room temperature and normal pressure naturally, to obtain a non-defoamed product, wherein the addition time of the initiator was 120 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer was 4.49 by weight.

[0083] Subsequently, in the defoaming step, the non-defoamed product was cooled to 55°C and placed in a degassing tank for defoaming, a defoaming agent was added in the degassing tank, stirred and allowed to stand for 30 minutes, and then cooled to 20°C, to obtain a dispersion containing a VAE copolymer.

[0084] In the pre-mixing step, 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C to obtain a polyvinyl alcohol solution, and 0.06 g of copper sulfate as a catalyst, the aforementioned polyvinyl alcohol solution, 25.1 g of an emulsifier (fatty alcohol polyoxyethylene ether, type: 6530, purchased from Rhodia Solvay Group, which is an aqueous solution of tridecyl alcohol ethoxylate containing 30 ethylene oxide units, with an active ingredient of 64 to 66 wt.%, and a hydrophilic-lipophilic balance (HLB) value of 17.2), vinyl acetate monomer (25% of the total amount of vinyl acetate), a pH buffer and a chelating agent were placed in a reactor and mixed at a temperature of 25 to 60°C to obtain a pre-mixed reaction solution; wherein in the aforementioned polyvinyl alcohol, the ratio of the weight of the large relative molecular weight polyvinyl alcohol to the weight of the small relative molecular weight polyvinyl alcohol was 0.25.

[0085] Subsequently, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 55 kgf / cm 2 ; then, a small amount of sodium erythorbate was added as a reducing agent, followed by the addition of a small amount of potassium persulfate as an initiator and a small amount of vinyl acetate monomer, and a preliminary reaction was performed for 0.5 hours; then, the pressure was raised to 60 kgf / cm 2and the temperature and pressure are naturally returned to room temperature and normal pressure after the addition is completed, to obtain a non-defoamed product, wherein the addition time of the initiator is 120 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 5.03 in terms of weight.

[0086] Subsequently, in the defoaming step, the non-defoamed product is cooled to 55°C and placed in a degassing tank to perform defoaming, a defoaming agent is added in the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C, to obtain a dispersion containing a VAE copolymer.

[0087] Comparative Example 1: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C and placed in a reactor to be mixed at a temperature of 25 to 60°C, to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight is 1.86.

[0088] Subsequently, in the polymerization reaction step, the temperature of the premixing reaction solution is raised to 70°C and ethylene gas is introduced to raise the pressure to 60 kgf / cm 2 ; then, a small amount of potassium persulfate is added as an initiator and a small amount of vinyl acetate monomer is added to perform a preliminary reaction for 0.5 hours; then, under the condition of maintaining the introduction of ethylene, a polymerization reaction is performed for a total reaction time of 521 minutes; specifically, during the polymerization reaction, the remaining initiator and vinyl acetate monomer are added dropwise, and after the addition is completed, the introduction of ethylene is stopped, and the temperature and pressure are naturally returned to room temperature and normal pressure, to obtain a non-defoamed product, wherein the addition time of the initiator is 155 minutes; wherein the ratio of the protective colloid polyvinyl alcohol to the vinyl acetate monomer is 4.03 in terms of weight.

[0089] Subsequently, in the defoaming step, the non-defoamed product is cooled to 55°C and placed in a degassing tank to perform defoaming, a defoaming agent is added in the degassing tank, stirred and left for 30 minutes, and then cooled to 20°C, to obtain a dispersion containing a VAE copolymer.

[0090] Comparative Example 2: In the premixing step, 88 g of polyvinyl alcohol is dissolved in water at a temperature of 88°C and placed in a reactor to be mixed at a temperature of 25 to 60°C, to obtain a premixing reaction solution; wherein, in the aforementioned polyvinyl alcohol, the ratio of the weight of the polyvinyl alcohol with a large relative molecular weight to the weight of the polyvinyl alcohol with a small relative molecular weight is 1.80.

[0091] Subsequently, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 Subsequently, in the defoaming step, the un-defoamed product was cooled to 55°C and placed in a degassing tank to be defoamed. After adding a defoaming agent, stirring and standing for 30 minutes, it was cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0092] Subsequently, in the defoaming step, the un-defoamed product was cooled to 55°C and placed in a degassing tank to be defoamed. After adding a defoaming agent, stirring and standing for 30 minutes, it was cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0093] Comparative Example 3: 88 g of polyvinyl alcohol was dissolved in water at a temperature of 88°C and placed in a reactor to be mixed at a temperature of 25 to 60°C to obtain a pre-mixed reaction solution. In the aforementioned polyvinyl alcohol, the ratio of the weight of polyvinyl alcohol with a large relative molecular weight to the weight of polyvinyl alcohol with a small relative molecular weight was 1.96.

[0094] Subsequently, in the polymerization step, the temperature of the pre-mixed reaction solution was raised to 70°C and ethylene gas was introduced to raise the pressure to 60 kgf / cm 2 Subsequently, in the defoaming step, the un-defoamed product was cooled to 55°C and placed in a degassing tank to be defoamed. After adding a defoaming agent, stirring and standing for 30 minutes, it was cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0095] Subsequently, in the defoaming step, the un-defoamed product was cooled to 55°C and placed in a degassing tank to be defoamed. After adding a defoaming agent, stirring and standing for 30 minutes, it was cooled to 20°C to obtain a dispersion containing a VAE copolymer.

[0096] In the preparation methods of Examples 1 to 12 and Comparative Examples 1 to 3, the total amount of vinyl acetate was 1700 g, the total amount of ethylene was 360 g, and the total amount of potassium persulfate was 20.1 g.

[0097] 2. Analysis method

[0098] In this application, the analysis and determination methods of the VAE copolymers of Examples 1 to 12 and Comparative Examples 1 to 3 and the dispersions containing the same are provided.

[0099] [Relative molecular weight analysis and gel permeation chromatography]

[0100] (First spectrum)

[0101] Sample pretreatment: The dispersion containing the VAE copolymer prepared by the above-mentioned manufacturing method was dried to remove the protective colloid (wherein the protective colloid of Examples 1 to 10 and Comparative Examples 1 to 3 was polyvinyl alcohol and water, and the protective colloid of Examples 11 and 12 was polyvinyl alcohol, water, and emulsifier), to obtain a VAE copolymer. Moreover, the sample pretreatment must meet the following criteria: whether the aforementioned VAE copolymer can be further prepared into a sample can be determined by dissolving the VAE copolymer in dimethylformamide (DMF) to obtain a 0.1 wt.% solution, and then filtering the solution through a 0.22 μm PTFE water filter into a sample bottle to obtain a sample. 1 H-NMR analysis and the signal values at 3.8 ppm to 4.0 ppm and 4.6 ppm to 5.0 ppm in the H-NMR spectrum. 1 H-NMR spectrum of the VAE copolymer, the signal at 4.6 ppm to 5.0 ppm has an integral value A, the signal at 3.8 ppm to 4.0 ppm has an integral value C, and the ratio of the integral value C to the integral value A is less than 0.050, for example, it can be 0.040, 0.030, 0.020, 0.010, 0.009, 0.008, 0.006, 0.004, 0.002, 0, or within the range formed by any two of the above-mentioned values. In this application, the ratio of the integral value C to the integral value A is controlled to be less than 0.050. 1 H-NMR spectrum of the VAE copolymer, the signal at 4.6 ppm to 5.0 ppm has an integral value A, the signal at 3.8 ppm to 4.0 ppm has an integral value C, and the ratio of the integral value C to the integral value A is less than 0.050, for example, it can be 0.040, 0.030, 0.020, 0.010, 0.009, 0.008, 0.006, 0.004, 0.002, 0, or within the range formed by any two of the above-mentioned values. In this application, the ratio of the integral value C to the integral value A is controlled to be less than 0.050.

[0102] Sample preparation: The VAE copolymer was prepared into a 0.1 wt.% dimethylformamide (DMF) solution, and filtered through a 0.22 μm PTFE water filter into a sample bottle to obtain a sample.

[0103] Instrument: Gel permeation chromatograph, model LC-2010AHT / CHT, instrument manufacturer Shimadzu, and detector Refractive Index Detector (RID).

[0104] Test conditions: injection volume: 40 μL; elution solution: DMF; elution flow rate: 1 mL / min; elution temperature: 50°C; elution time: 25 min.

[0105] Test method: The sample was placed in a gel permeation chromatography instrument and the absorption spectrum was measured from 0 to 25 minutes using a differential refractive index detector. The resolution of the Fourier transform infrared spectrometer was 1 cm -1 The spectrum was scanned 12 times, and the spectral absorption intensity is the absorbance of the peak at a specified wavelength (arbitrary units). Based on this, a first spectrum was obtained, with the X-axis representing the elution time and the Y-axis representing the signal intensity corresponding to the elution time from 0 to 25 minutes.

[0106] (First data conversion)

[0107] The first data conversion divides each signal intensity of the first spectrum by a maximum signal intensity (Ymax) in the first spectrum to obtain a signal intensity ratio (Yx), and converts the Y axis of the first spectrum into the signal intensity ratio.

[0108] (Second data conversion)

[0109] Standard: Shodex STANDARD SM-105 (polystyrene, relative molecular weight range 1,300 to 2,630,000)

[0110] The second data conversion is based on a standard sample to prepare a calibration curve and obtain the relationship between relative molecular weight and elution time, and the X-axis of the first spectrum is converted into relative molecular weight.

[0111] Based on this, the relative molecular weight distribution curve is obtained after the first and second data conversions. The graph area M of the relative molecular weight of 10,000 to 100,000 is calculated based on the relative molecular weight distribution curve. L / Spectrum area M with relative molecular weight of 100,001 to 2,500,000 H The ratio (hereinafter referred to as M H / M L ), located in the map area M H The molecular Mw (hereinafter referred to as Mw H ) and located in the spectrum area M H The molecular weight of Mn (hereinafter referred to as Mn H ) and their ratio (hereinafter referred to as Mw H / Mn H ), located in the map area M L The molecular weight of Mn (hereinafter referred to as Mn L ), Mw and Mn of the VAE copolymer and their ratio (hereinafter referred to as Mw / Mn).

[0112] [Analysis of the content of residual unreacted vinyl acetate (VAM) in the dispersion (hereinafter referred to as the content of VAM)]

[0113] Test method: (1) titrate the dispersion containing VAE copolymer prepared by the above manufacturing method with 0.1 N bromine water; (2) take the reverse point of the oxidation-reduction potential curve as the titration end point, i.e. the equivalent point; and (3) calculate the content of VAM from the bromine water equivalent.

[0114] 3. Evaluation method and results

[0115] [Freeze-thaw stability evaluation]

[0116] Standard method: GB / T 9268-2008 Determination of freeze-thaw resistance of latex paint

[0117] Sample preparation: take 150 grams of the dispersion containing VAE copolymer prepared by the above manufacturing method and place it in a 300 mL jar.

[0118] Test method: (1) after sealing the bottle mouth, place it in a freezer and on a shelf to avoid contact with the wall or bottom of the freezer; (2) keep the temperature at -7℃ ± 2℃ and place it for 18 hours; (3) take the sealed sample bottle out of the freezer and place it in an environment with a temperature of 25℃ ± 2℃ and let it stand for 6 hours; steps (1) to (3) are one cycle, and a total of 3 cycles are performed, which is one freeze-thaw test. And, the freeze-thaw test is performed on the first day, the second day and the third day respectively; that is, 1 freeze-thaw test is performed on the first day, 2 freeze-thaw tests are performed on the second day, and 3 freeze-thaw tests are performed on the third day.

[0119] Evaluation criteria:

[0120] Open the sample bottle after the above freeze-thaw test, observe the sample bottle after thorough stirring, and evaluate it according to the following criteria:

[0121] : No hardening, flocculation or separation occurs

[0122] : Slightly viscous

[0123] : Difficult to stir

[0124] ╳: Caking

[0125] Further, the freeze-thaw stability of the VAE copolymers of Examples 1 to 12 and Comparative Examples 1 to 3 of the present application is evaluated in combination with the M H / M L , Mw H , Mn H , Mw H / MnH 、Mn L , Mw, Mn, Mw / Mn, the residue derived from vinyl acetate (VAM) in the dispersion, and the particle size distribution D50 of the particles formed by the VAE copolymer and the dispersion matrix (the dispersion matrix of Examples 1 to 10 and Comparative Examples 1 to 3 is polyvinyl alcohol and water, and the dispersion matrix of Examples 11 and 12 is polyvinyl alcohol, water and an emulsifier) ​​are collectively presented in Table 1.

[0126] Table 1

[0127]

[0128] *: Since Example 9 formed lumps on the second day of freeze-thaw stability evaluation, no record was made on the third day.

[0129] Table 1 (continued)

[0130]

[0131] *: Since Comparative Examples 1 to 3 formed lumps on the first day of the freeze-thaw stability evaluation, the second and third days were not recorded.

[0132] According to Table 1, the M values ​​of the VAE copolymers of Examples 1 to 12 are as follows: H / M L The M values ​​of the VAE copolymers of Comparative Examples 1 to 3 were all within the range of 2.33 to 4.71. It was observed that no lumps, flocculation or separation occurred in the freeze-thaw stability evaluation on the first day of the experiment, and the copolymers had excellent freeze-thaw resistance. H / M L If the M values ​​of the VAE copolymers do not fall within the above-mentioned ideal range, the VAE copolymers will clump during the freeze-thaw stability evaluation on the first day and will not achieve the above-mentioned technical effects. H / M L Only by controlling it within the ideal range can the freeze-thaw resistance of the VAE copolymer be improved.

[0133] Furthermore, without being bound by a particular theory, the inventors of the present application have found that when the Mw of the VAE copolymer is H / Mn H The Mw of the VAE copolymers of Examples 1 to 6, 11 and 12 is controlled to be less than or equal to 1.55, and the VAE copolymers have excellent freeze-thaw resistance over time. H / Mn HVAE copolymers of Examples 7 to 10 and 12 to 14, whose Mw / Mn H / Mn H all do not fall within the above-mentioned ideal range, the VAE copolymers of these Examples have a little hard lump, flocculation or separation phenomenon to occur and are difficult to stir or caking in the freeze-thaw stability evaluation on the second or third day.

[0134] In summary, the VAE copolymers of the present application have excellent freeze-thaw resistance; and, when the Mw / Mn H / Mn H of the VAE copolymers of the present application are controlled within a certain range, further excellent freeze-thaw resistance over time can be obtained.

[0135] In the present application, all ranges provided are intended to include every particular range within the given range and combinations of sub-ranges within the given range. In addition, unless otherwise indicated, all ranges provided herein include the endpoints of the range. Thus, ranges 1 to 5 specifically include 1, 2, 3, 4 and 5, as well as sub-ranges such as 2 to 5, 3 to 5, 2 to 3, 2 to 4, 1 to 4, etc.

[0136] All publications and patent applications cited in this specification are herein incorporated by reference, and for any purpose the citation of any publication or patent application is not to be construed as an admission that it is prior art relative to the present application. In the case of inconsistencies between any publications or patent applications incorporated by reference and the disclosure herein, the disclosure herein will prevail.

Claims

1. A vinyl acetate-ethylene copolymer, characterized in that The relative molecular weight distribution curve obtained by gel permeation chromatography includes: A chromatogram area M with a relative molecular weight of 10,000 to 100,000 L ,and A chromatogram area M with a relative molecular weight of 100,001 to 2,500,000 H ; Among them, M H / M L 2.33 to 4.

71.

2. The VAE copolymer of claim 1 , wherein the relative molecular weight distribution curve exhibits a bimodal distribution and is plotted from a first graph through first and second data conversions, wherein the Y-axis of the first graph represents signal intensity corresponding to elution times of 0 to 25 minutes as measured by gel permeation chromatography, and the X-axis represents elution time; in, The first data conversion is performed by dividing each signal intensity by a maximum signal intensity (Ymax) in the first spectrum to obtain a signal intensity ratio (Yx), and the Y axis of the first spectrum is converted to the signal intensity ratio. The second data conversion is performed by preparing a calibration curve based on a standard and obtaining the relationship between relative molecular weight and elution time, and the X axis of the first spectrum is converted to relative molecular weight.

3. The VAE copolymer according to claim 1, wherein The weight average relative molecular weight Mw / number average relative molecular weight Mn of the VAE copolymer is 1.59 to 2.

20.

4. The VAE copolymer according to claim 3, wherein The VAE copolymer has an Mw / Mn of 1.64 to 2.

18.

5. The VAE copolymer according to any one of claims 1 to 4, wherein The VAE copolymer is located in the spectral area M L The molecules have an Mn of 44,000 to 74,000.

6. The VAE copolymer according to any one of claims 1 to 4, wherein The VAE copolymer is located in the spectral area M H The molecule has an Mw / Mn ratio of less than or equal to 1.

55.

7. A dispersion, characterized in that Include: The VAE copolymer according to any one of claims 1 to 6, and A dispersion matrix. The dispersion according to claim 7 , which is in the form of an emulsion.

9. The dispersion of claim 7, wherein the content of residual unreacted vinyl acetate in the dispersion is less than or equal to 0.1000 wt. %, based on the total weight of the dispersion.

10. The dispersion of claim 7, wherein the dispersion matrix comprises polyvinyl alcohol, water, hydroxyethyl cellulose, an emulsifier, a dispersant, or a combination thereof.

11. A coating composition, characterized in that Comprising the dispersion according to claim 7.

12. The coating composition of claim 11, further comprising a powder component, and The powder component is dispersed in the dispersion; or The powder component is packaged independently outside the dispersion.

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