Continuous production of aqueous organic peroxide emulsions

Abstract

To provide a continuous process and a system for producing aqueous organic peroxide emulsions comprising organic peroxides that have a low self-accelerating decomposition temperature.SOLUTION: A continuous process comprises: a) a pre-emulsion mixture comprising at least one organic peroxide having a self-accelerating decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one anti-freeze agent, water, and optionally at least one emulsifier, wherein the pre-emulsion mixture is fed to an inlet of an in-line emulsifier at a temperature of at least 12°C lower than the SADT of the organic peroxide; and b) transferring the emulsion from an outlet of the in-line emulsifier to a heat exchanger downstream of the outlet of the in-line emulsifier, wherein the heat exchanger reduces the temperature of the aqueous organic peroxide emulsion to a temperature of at least 12°C lower than the SADT of the organic peroxide.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a continuous process for producing an aqueous organic peroxide emulsion containing an organic peroxide having a low self-accelerating decomposition temperature, and a system for carrying out the continuous process.

Background Art

[0002] In the technical field of manufacturing aqueous organic peroxide emulsions, there are many conventional methods. For example, International Patent Publication No. 99 / 31194 describes that the emulsification step can be carried out by using any conventional dispersing device, such as a mechanical rotary stirrer of paddle type, propeller type, or turbine type, a homogenizer such as a colloid mill, an ultrasonic homogenizer, a high-speed shearing device, and a line mixer.

[0003] These conventional options can be used to prepare aqueous emulsions of organic peroxides that are stable over a wide range of temperatures, but the currently available options are much more limited for organic peroxides with low thermal stability. In that regard, for organic peroxides having a low self-accelerating decomposition temperature (SADT, e.g., about 25 °C or lower), the emulsification processes used so far are batch processes. This is because it is necessary to maintain the organic peroxide mixture at a low temperature (usually around 0 °C) to prevent the rapid decomposition of the organic peroxide mixture during the emulsification process, which can be extremely dangerous (e.g., it can lead to an explosion). Therefore, attempts to continuously produce aqueous emulsions of these peroxides on an industrial scale have been considered too dangerous.

[0004] U.S. Patent No. 6,350,835 discloses an aqueous emulsion of a peroxyester that is liquid at -20°C. While Patent No. 6,350,835 describes the preference for the emulsification process to be carried out at a temperature below the SADT of the peroxyester, it does not describe how the emulsification process may be carried out in a safe and continuous manner. The processing examples in Patent No. 6,350,835 only provide a conventional batch process for producing such an aqueous emulsion of a peroxyester.

[0005] U.S. Patent No. 4,734,135 discloses aqueous emulsions of peroxydicarbonates and diacylperoxides. Similar to U.S. Patent No. 6,350,835, the processing examples in U.S. Patent No. 4,734,135 only provide conventional batch processes for producing aqueous emulsions of such peroxides. U.S. Patent No. 4,734,135 infers that the emulsion process may be carried out continuously by an emulsifying device such as a line mixer, attached to a cooling device (i.e., a jacketed (cooling jacket) in-line mixer), but this is not illustrated in U.S. Patent No. 4,734,135, nor does it provide any further technical details that would enable a person skilled in the art to implement this in a simple manner for any peroxide (and certainly not having low SADT).

[0006] Many advantages of continuous processes over batch processes are well known. For example, continuous processes increase productivity and generally require less equipment footprint. However, to the best of our knowledge, no successful industrial-scale continuous process for producing aqueous emulsions of organic peroxides with low SADT has yet been developed.

[0007] Therefore, the objective of this disclosure was to develop a continuous process for producing aqueous emulsions of organic peroxides having low SADT. A further objective was to achieve this goal without the need to develop new specialized equipment. [Overview of the project]

[0008] The inventors have found that these objectives can be achieved using readily available equipment. In this regard, by cooling an organic peroxide-containing pre-emulsion mixture before feeding it into an in-line emulsifier, and then cooling the organic peroxide emulsion using a downstream heat exchanger, the inventors have developed a relatively simple but highly effective process and apparatus configuration that solves the long-standing need for producing aqueous emulsions of organic peroxides having low SADT.

[0009] Therefore, in a first aspect, the present invention relates to a continuous process for generating an organic peroxide emulsion, wherein the process is: a) Supplying a preemulsification mixture to the inlet of an inline emulsifier, wherein the preemulsification mixture comprises at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, and the preemulsification mixture is supplied to the inlet at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably at about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide, and b) Transferring an aqueous organic peroxide emulsion from the outlet of an inline emulsifier to a heat exchanger located downstream of the outlet of the inline emulsifier, wherein the heat exchanger reduces the temperature of the aqueous organic peroxide emulsion to a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, and most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, about 15°C to about 20°C lower than the SADT of the organic peroxide.

[0010] In a second aspect, the present invention relates to a system for continuously generating an organic peroxide emulsion, wherein the system is At least one container for preparing and / or receiving a preemulsification mixture comprising at least one organic peroxide having a self-accelerating decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, wherein the at least one container is equipped with means for preparing the preemulsification mixture and for cooling and / or maintaining the preemulsification mixture at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably at about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide. An inline emulsifier having at least one inlet and at least one outlet, wherein the inline emulsifier is in fluid communication with at least one vessel, is located downstream of at least one vessel, and is configured to receive a pre-emulsion mixture at at least one inlet at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably at about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at a temperature of about 15°C to about 20°C lower than the SADT of the organic peroxide, A heat exchanger in fluid communication with an inline emulsifier and located downstream of the inline emulsifier, wherein the heat exchanger is configured to reduce the temperature of the aqueous organic peroxide emulsion obtained from at least one outlet of the inline emulsifier to a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, to a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide, and The system comprises a pack-out unit that optionally communicates with the heat exchanger and is located downstream of the heat exchanger.

[0011] By using a specific supply temperature in combination with the introduction of a heat exchanger downstream of the outlet of the inline emulsifier, the safety profile of the emulsification process is now significantly improved to the extent that it can be safely implemented in a continuous and highly scalable manner (i.e., continuously at an industrial scale).

[0012] To avoid any misunderstanding, a "pre-emulsion mixture" is a mixture of components that have not been subjected to emulsification conditions (and therefore are not yet in the form of a stable emulsion).

[0013] The cooled aqueous organic peroxide emulsion obtained in step b) can be used directly (i.e., manufactured and used on-site) or transferred to a pack-out unit located downstream of the heat exchanger (packaged and shipped). In this respect, the present invention provides a small-floor, easily installable system for on-site continuous production of aqueous organic peroxide emulsions having low SADT. This represents a significant improvement in ease of production, cost, safety, and environmental impact (smaller amount of raw materials to be transported).

[0014] SADT is the lowest ambient temperature at which self-accelerated decomposition occurs in a product within packaging used for transport. The method for determining the SADT of organic peroxides is described in detail in the United Nations Manual of Test Methods and Criteria, 7th Revision (2019), Test Series H.4: Thermal Storage Test, and this manual and test method are incorporated herein by reference. This method determines the lowest constant ambient temperature at which a thermally unstable substance undergoes exothermic decomposition under the conditions representing the substance when packaged. The method is based on the Semiyonov theory of thermal explosion, i.e., the primary resistance to heat flow is considered to be in the container walls. The method is applied to IBCs and small tanks (up to 2m). 3 It can be used to determine the SADT of substances in the packaging, including ). To avoid any doubt, the SADT values ​​referred to herein are determined for organic peroxides in high-density polyethylene (HDPE) packaging with a volume of 20-30 liters, according to the method described in the United Nations manual (Test Series H.4: Thermal Storage Test) referenced above.

[0015] The emulsion contains at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or lower, preferably 20°C or lower, preferably 15°C or lower, preferably 10°C or lower, preferably 5°C or lower, and may be about 0°C or lower. Preferred organic peroxides include peroxyesters, peroxydicarbonates, and diacyl peroxides. Peroxyesters and diacyl peroxides are preferred. Examples of preferred organic peroxides for use in accordance with the present invention include diisobutyryl peroxide (SADT 0°C), di-n-propyl peroxydicarbonate (SADT 0°C), diisopropyl peroxydicarbonate (SADT 5°C), di-n-butyl peroxydicarbonate (SADT 0°C), di-sec-butyl peroxydicarbonate (SADT 0°C), di(2-ethoxyethyl) peroxydicarbonate (SADT 10°C), di(2-ethylhexyl) peroxydicarbonate (SADT 5°C), 1,3-di(prop-2,2-diyl)benzene bis(neodecanoyl)peroxide (SADT 10°C), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (SADT 15°C), 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (SADT 10°C), and tert-amyl peroxyneodecanoate (SADT 15°C). These include cumyl peroxyneodecanoate (SADT 10°C), di-n-butyryl peroxide (SADT 25°C), tert-butyl peroxyneodecanoate (SADT 20°C), 1,1,3,3-tetramethylbutyl peroxypivalate (SADT 20°C); tert-amyl peroxypivalate (SADT 25°C), tert-butyl peroxypivalate (SADT 25°C), di(3,5,5-trimethylhexanoyl) peroxide (SADT 25°C), or mixtures thereof.

[0016] Organic peroxide emulsions typically contain 25–70% by weight of organic peroxide, based on the total weight of the emulsion. The amount of organic peroxide in the emulsion is preferably 30–65% by weight, more preferably 35–60% by weight, and most preferably 40–60% by weight. The organic peroxide may be introduced into the emulsification process disclosed herein in the form of phosphorylated organic peroxide. In this regard, the peroxide, such as an inert desensitizing solvent, may be diluted and / or dissolved using any suitable desensitizing agent. Such inert desensitizing solvents are well known in the art and include, for example, isododecane and mineral oil. For example, 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (SADT 10°C) is commercially available from Nouryon® in a lean form as a 75% solution of odorless mineral spirits ("Trigonox® 193-CH75").

[0017] The amount of water in the emulsion is typically in the range of 20-70% by weight, more preferably 25-50% by weight, and most preferably 25-40% by weight, relative to the total weight of the emulsion.

[0018] The emulsion contains at least one antifreeze agent, and may contain a combination of two or more antifreeze agents. Any conventional antifreeze agent can be used. Preferably, the agents used are methanol, ethanol, isopropanol, (ethylene) glycol, propanediol, glycerol, and mixtures thereof, more preferably methanol, ethanol, propanediol, and mixtures thereof. These agents are known to have little effect on the polymerization process. For those skilled in the art, balancing the water-to-antifreeze ratio is not difficult. Typically, the amount of antifreeze used in the emulsion according to the present invention is less than the amount of water.

[0019] The emulsion also contains at least one protective colloid. Any conventional protective colloid can be used. Suitable protective colloids include partially hydrolyzed (or saponified) polyvinyl acetate, polyvinylpyrrolidone, polyacrylate, cellulose, cellulose derivatives, starch, and starch derivatives. Particularly useful are partially hydrolyzed / saponified polyvinyl acetate, cellulose, cellulose derivatives, starch, and starch derivatives. Typically, a polyvinyl acetate (PVA) component is used, preferably PVA with a degree of hydrolysis of 50-90 mol%, more preferably 55-80 mol%, and most preferably 60-70 mol%. The amount of protective colloid used in the emulsion according to the present invention depends on the type and amount of organic peroxide, as well as the desired viscosity of the final emulsion, but is typically used in an amount of about 0.1 to about 5% by weight, based on the total weight of the emulsion.

[0020] The emulsion according to the present invention may contain at least one conventional emulsifier. Suitable emulsifiers are known to those skilled in the art and include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, as well as mixtures thereof. They may be incorporated in typical amounts, such as about 0.05 to about 4% by weight, based on the total weight of the emulsion. Preferably, a nonionic surfactant having an HLB (hydrophilic-lipophilic balance) value of 7 or higher, and more preferably 16 or higher, is used. Alternatively, the emulsion according to the present invention may contain a very small amount of emulsifier, or may contain none at all. It has been found that substantially or completely removing emulsifiers, particularly in the form of nonionic, anionic, cationic, and amphoteric surfactants, from peroxide emulsions is very beneficial in the production of polyvinyl chloride (PVC). In this regard, such “emulsifier-free” emulsions of low SADT peroxides (particularly diisobutyryl peroxide, SADT 0°C) have been found to produce high-quality PVC from vinyl chloride monomer (VCM) with an unexpected improvement in the drying properties of the polymer (the drying rate of the resulting PVC polymer is substantially increased, and therefore the drying time of the polymer is reduced, which is important for the industrial-scale production of PVC). Accordingly, in preferred embodiments, the emulsion according to the present invention may contain an emulsifier in a total amount of 0% to 0.17% by weight, based on the total weight of the emulsion. More preferably, the emulsion according to the present invention may contain a (nonionic) surfactant having an HLB (hydrophilic-lipophilic balance) value of 7 or more (based on the total weight of the emulsion), in an amount of 0% to 0.17% by weight, more preferably 0% by weight. Accordingly, the emulsion according to the present invention may contain an emulsifier in a total amount of 0% to about 4% by weight, based on the total weight of the emulsion.

[0021] The aqueous organic peroxide emulsion of the present invention may also optionally contain other additives, including phosphate buffer and citrate buffer, sequestering agents, biocides, such as bactericides, ozone degradation inhibitors, antioxidants, degradation inhibitors, ultraviolet stabilizers, co-agents, comonomers, antistatic agents, foaming agents, mold release agents, and pH adjusters such as process oils. These additives may be added in normal amounts.

[0022] The processes and systems of this disclosure require an inline emulsifier. Suitable inline emulsifiers for use in this process are well known in the art, including, but not limited to, those discussed in International Publication No. 99 / 31194 and those described in U.S. Patent No. 2004 / 223407. Suitable inline emulsifiers are widely available, including, but not limited to, the Process Pilot 2000 and DRS 2000, commercially available from IKA®-WERKE GmbH & Co KG, and their various configurations and scaled-up equivalents. While these well known inline emulsifiers are typically not used at low operating temperatures (e.g., sub-zero), routine modifications to accommodate low temperatures are readily available (e.g., by changing the material of replaceable components such as O-rings to one known to be mechanically stable at very low temperatures). Such routine modifications are within the scope of routine capability for those skilled in the art.

[0023] The residence time of the organic peroxide mixture in the inline emulsifier is preferably about 1 to about 10 seconds, preferably about 2 to about 8 seconds, and more preferably about 3 to about 6 seconds, such as about 3.8 to about 5.5 seconds.

[0024] The in-line emulsifier preferably comprises at least one mill head, preferably at least two mill heads, and may also comprise at least three mill heads. The in-line emulsifier may comprise mill heads in a rotor-stator arrangement, may be configured as a single-stage rotor-stator system, or may be configured as a multi-stage (e.g., two or three) rotor-stator system. The mill heads may be of a coarse type, a medium type, a fine type, or a combination thereof. In a preferred embodiment, the tip speed of the mill head or each mill head is from about 15 meters per second (m / s) to about 50 m / s, preferably from about 20 m / s to about 45 m / s, more preferably from about 25 m / s to about 40 m / s.

[0025] Configuring an in-line emulsifier known in the art to operate within these operating parameters is within the routine capabilities of those skilled in the art.

[0026] Thus, in a preferred embodiment, the continuous process for producing an organic peroxide emulsion is a) Supplying a pre-emulsion mixture to the inlet of an in-line emulsifier, the in-line emulsifier comprising at least one mill head, preferably at least two mill heads, the tip speed of the mill head or each mill head being from 15 m / s to 50 m / s, preferably from about 20 m / s to about 45 m / s, more preferably from about 25 m / s to about 40 m / s, the pre-emulsion mixture comprising at least one organic peroxide having a self-accelerating decomposition temperature (SADT) of 25 °C or less, at least one protective colloid, at least one antifreeze agent, water, and optionally at least one emulsifier, the pre-emulsion mixture being supplied to the inlet at a temperature at least 12 °C lower than the SADT of the organic peroxide, preferably at least 14 °C lower than the SADT of the organic peroxide, more preferably from about 15 °C to about 35 °C lower than the SADT of the organic peroxide, most preferably from about 15 °C to about 25 °C lower than the SADT of the organic peroxide, for example, from about 15 °C to about 20 °C lower than the SADT of the organic peroxide, and b) transferring the aqueous organic peroxide emulsion from the outlet of the in-line emulsifier to a heat exchanger located downstream of the outlet of the in-line emulsifier, the heat exchanger reducing the temperature of the aqueous organic peroxide emulsion to a temperature at least 12 °C lower than the SADT of the organic peroxide, preferably at least 14 °C lower than the SADT of the organic peroxide, more preferably about 15 °C to about 35 °C lower than the SADT of the organic peroxide, most preferably about 15 °C to about 25 °C lower than the SADT of the organic peroxide, for example, about 15 °C to about 20 °C lower than the SADT of the organic peroxide, including transferring the pre-emulsion mixture in the in-line emulsifier having a residence time of about 1 to about 10 seconds, preferably about 2 to about 8 seconds, more preferably about 3 to about 6 seconds, for example, about 3.8 to about 5.5 seconds.

[0027] In a preferred embodiment, a system for continuously producing an organic peroxide emulsion comprises · at least one container (e.g., at least one (continuous) stirred tank reactor) for preparing and / or receiving a pre-emulsion mixture comprising at least one organic peroxide having a self-accelerating decomposition temperature (SADT) of 25 °C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, the at least one container comprising means (e.g., internal and / or external cooling coils, external cooling jackets, etc.) for cooling and / or maintaining the pre-emulsion mixture at a temperature at least 12 °C lower than the SADT of the organic peroxide, preferably at least 14 °C lower than the SADT of the organic peroxide, more preferably about 15 °C to about 35 °C lower than the SADT of the organic peroxide, most preferably about 15 °C to about 25 °C lower than the SADT of the organic peroxide, for example, about 15 °C to about 20 °C lower than the SADT of the organic peroxide; An inline emulsifier having at least one inlet and at least one outlet, wherein the inline emulsifier comprises at least one mill head, preferably at least two mill heads, and the tip velocity of the mill head or each mill head is 15 m / s to 50 m / s, preferably about 20 m / s to about 45 m / s, more preferably about 25 m / s to about 40 m / s, and the inline emulsifier is in fluid communication with at least one vessel and is located downstream of at least one vessel, and is configured to receive the preemulsification mixture at at least one inlet at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, about 15°C to about 20°C lower than the SADT of the organic peroxide, A heat exchanger in fluid communication with an inline emulsifier and located downstream of the inline emulsifier, wherein the heat exchanger is configured to reduce the temperature of the aqueous organic peroxide emulsion obtained from at least one outlet of the inline emulsifier to a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, to a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide, and Optionally, the system includes a pack-out unit located downstream of the heat exchanger. The system is configured such that the residence time of the pre-emulsification mixture in the in-line emulsifier is about 1 to about 10 seconds, preferably about 2 to about 8 seconds, more preferably about 3.8 to about 5.5 seconds, for example, about 3 to about 6 seconds.

[0028] In a preferred embodiment, the system further comprises at least one mixing device located upstream of at least one vessel and in fluid communication with at least one vessel for preparing and / or receiving a preemulsification mixture. In the above embodiment, at least one mixing device prepares a mixture comprising a protective colloid, an antifreeze, water, and optionally an emulsifier. The mixture is then transferred to at least one vessel, where it is mixed with at least one organic peroxide having a SADT of 25°C or less to form a preemulsification mixture. In one embodiment, the mixing device may be a continuous stirred tank reactor (CSTR). In another embodiment, the mixing device may be an inline static mixer comprising one or more static mixer elements. Such mixers are well known to those skilled in the art.

[0029] Therefore, in a preferred embodiment, the present invention relates to a system for continuously generating an organic peroxide emulsion, wherein the system is • At least one mixing apparatus for preparing a mixture comprising at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, • At least one container having fluid communication with at least one mixing device and positioned downstream of at least one mixing device, and configured to receive a mixture comprising at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, wherein the at least one container separately receives at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or less, and the mixture comprises at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier. The present invention further comprises means for preparing a preemulsification mixture comprising selectively at least one emulsifier, wherein at least one container is equipped with means for cooling and / or maintaining the preemulsification mixture at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably at about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at least one container equipped with means for cooling and / or maintaining the preemulsification mixture at a temperature at about 15°C to about 20°C lower than the SADT of the organic peroxide, An inline emulsifier having at least one inlet and at least one outlet, wherein the inline emulsifier is in fluid communication with at least one vessel, is located downstream of at least one vessel, and is configured to receive a pre-emulsion mixture at at least one inlet at a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably at about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at a temperature of about 15°C to about 20°C lower than the SADT of the organic peroxide, A heat exchanger in fluid communication with an inline emulsifier and located downstream of the inline emulsifier, wherein the heat exchanger is configured to reduce the temperature of the aqueous organic peroxide emulsion obtained from at least one outlet of the inline emulsifier to a temperature at least 12°C lower than the SADT of the organic peroxide, preferably at least 14°C lower than the SADT of the organic peroxide, more preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, to a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide, and The system comprises a pack-out unit that optionally communicates with the heat exchanger and is located downstream of the heat exchanger.

[0030] It should be noted that various elements of the present invention, including but not limited to preferred ranges of various parameters, can be combined as long as they are not mutually exclusive.

[0031] The present invention is illustrated by the following embodiments, but is not limited thereto. [Brief explanation of the drawing]

[0032] [Figure 1] This is a schematic diagram of the system according to the present invention. [Modes for carrying out the invention]

[0033] Referring to Figure 1, a continuous process was developed for the continuous production of an aqueous emulsion of diisobutyryl peroxide (SADT 0°C).

[0034] A pre-emulsion mixture containing methanol (15% by weight), polyvinyl acetate having a degree of hydrolysis of 50-75 mol% (1.5% by weight), a nonionic surfactant (1% by weight), diisobutyryl peroxide (40% by weight), and water, is placed in a container. 1 It was cooled to -15°C while being stirred inside.

[0035] container 1 Cooled pre-emulsification mixture from -15°C in an in-line emulsifier 2 It was continuously supplied to the inlet. The inline emulsifier applied shear force to the pre-emulsion mixture to form a stable emulsion of diisobutyryl peroxide. The emulsified product was discharged from the outlet of the inline emulsifier and into the heat exchanger. 3 The product was then transferred to a pack-out buffer tank and cooled to -15°C. 4 It was supplied and then packed out from the downstream pack line.

[0036] No safety concerns were observed at any point during the continuous emulsification process.

[0037] Device Features Description: 1. A container equipped with a stirrer and an external cooling coil configured to cool the pre-emulsion mixture contained inside to -15°C. 2. A DISPAX-REACTOR® Type DRS 2000 / 10 equipped with at least two mill heads, each operating at a tip velocity of approximately 40 m / s and having a peroxide residence time of 3.8 to 5.5 seconds. 3. Heat exchanger configured to reduce the temperature of the organic peroxide emulsion to -15°C 4. Packaging unit (buffer tank and downstream packaging container)

[0038] In this specification, unless expressly indicated otherwise, the term “or” is used to mean an operator that returns true when either or both of the stated conditions are met, as opposed to the “exclusive or” operator which requires only one of the conditions to be met. The word “comprising” is used to mean “including” and not “consisting of.” All prior teachings identified above are incorporated herein by reference. No acknowledgment of any document previously published herein should be construed as an acknowledgment or representation that such teaching was common knowledge in Europe or elsewhere as of the date of this specification. The present invention includes the following embodiments. Section 1. A continuous process for generating organic peroxide emulsions, a) Supplying a pre-emulsification mixture to the inlet of an inline emulsifier, wherein the pre-emulsification mixture comprises at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, and the pre-emulsification mixture is supplied to the inlet at a temperature at least 12°C lower than the SADT of the organic peroxide. b) A method comprising transferring an aqueous organic peroxide emulsion from the outlet of the inline emulsifier to a heat exchanger downstream of the outlet of the inline emulsifier, wherein the heat exchanger reduces the temperature of the aqueous organic peroxide emulsion to a temperature at least 12°C lower than the SADT of the organic peroxide. Section 2. The method according to claim 1, wherein the preemulsion mixture of step a) is supplied to the inlet at a temperature at least 14°C lower than the SADT of the organic peroxide, preferably at a temperature about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably at a temperature about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, at a temperature about 15°C to about 20°C lower than the SADT of the organic peroxide. Section 3. The method according to any one of claims 1 to 2, wherein in step b), the heat exchanger reduces the temperature of the organic peroxide emulsion to a temperature at least 14°C lower than the SADT of the organic peroxide, preferably about 15°C to about 35°C lower than the SADT of the organic peroxide, most preferably about 15°C to about 25°C lower than the SADT of the organic peroxide, for example, about 15°C to about 20°C lower than the SADT of the organic peroxide. Section 4. The method according to any one of claims 1 to 3, further comprising transferring the cooled aqueous organic peroxide emulsion of step b) to a pack-out unit located downstream of the heat exchanger. Section 5. The method according to any one of claims 1 to 4, wherein the organic peroxide has a self-accelerated decomposition temperature (SADT) of 20°C or less, preferably 15°C or less, preferably 10°C or less, and preferably 5°C or less. Section 6. The method according to any one of claims 1 to 5, wherein the organic peroxide is selected from peroxyesters, peroxydicarbonates, diacyl peroxides, or mixtures thereof. Section 7. The aforementioned organic peroxides are diisobutyryl peroxide (SADT 0°C), di-n-propyl peroxydicarbonate (SADT 0°C), diisopropyl peroxydicarbonate (SADT 5°C), di-n-butyl peroxydicarbonate (SADT 0°C), di-sec-butyl peroxydicarbonate (SADT 0°C), di(2-ethoxyethyl)peroxydicarbonate (SADT 10°C), di(2-ethylhexyl) peroxydicarbonate (SADT 5°C), 1,3-di(prop-2,2-diyl)benzene bis(neodecanoyl)peroxide (SADT 10°C), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (SADT 15°C), 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (SADT 10°C), and tert-amyl peroxyneodecanoate (SADT The method according to any one of claims 1 to 6, selected from: cumyl peroxyneodecanoate (SADT 10°C), di-n-butyryl peroxide (SADT 25°C), tert-butyl peroxyneodecanoate (SADT 20°C), 1,1,3,3-tetramethylbutyl peroxypivalate (SADT 20°C); tert-amyl peroxypivalate (SADT 25°C), tert-butyl peroxypivalate (SADT 25°C), di(3,5,5-trimethylhexanoyl) peroxide (SADT 25°C), or a mixture thereof. Section 8. The method according to any one of claims 1 to 7, wherein the preemulsion mixture contains 25 to 70% by weight of an organic peroxide based on the total weight of the preemulsion mixture. Section 9. The method according to any one of claims 1 to 8, wherein the at least one protective colloid is selected from partially hydrolyzed (or saponified) polyvinyl acetate, polyvinylpyrrolidone, polyacrylate, cellulose, cellulose derivatives, starch, and starch derivatives, preferably partially hydrolyzed (or saponified) polyvinyl acetate. Section 10. The method according to any one of claims 1 to 9, wherein the at least one emulsifier is omitted from the preemulsion mixture, or is selected from nonionic, anionic, cationic, and amphoteric surfactants, and mixtures thereof, preferably nonionic surfactants. Section 11. The method according to any one of claims 1 to 10, wherein the at least one antifreeze is selected from methanol, ethanol, isopropanol, (ethylene) glycol, propanediol, glycerol, and mixtures thereof. Section 12. The method according to any one of claims 1 to 11, wherein the inline emulsifier comprises at least one mill head, preferably at least two mill heads, and the tip speed of the or each mill head is about 15 meters / second (m / s) to about 50 m / s, preferably about 20 m / s to about 45 m / s, more preferably about 25 m / s to about 40 m / s. Section 13. The method according to any one of claims 1 to 12, wherein the residence time of the pre-emulsification mixture in the in-line emulsifier is about 1 to about 10 seconds, preferably about 2 to about 8 seconds, more preferably about 3 to about 6 seconds, for example, about 3.8 to about 5.5 seconds. Section 14. A system for continuously generating organic peroxide emulsions, At least one container for preparing and / or receiving a pre-emulsion mixture comprising at least one organic peroxide having a self-accelerating decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, wherein the at least one container includes means for cooling and / or maintaining the pre-emulsion mixture at a temperature at least 12°C lower than the SADT of the organic peroxide, An inline emulsifier comprising at least one inlet and at least one outlet, wherein the inline emulsifier is in fluid communication with the at least one container, is located downstream of the at least one container, and is configured to receive the pre-emulsified mixture at a temperature at least 12°C lower than the SADT of the organic peroxide, and A device comprising: a heat exchanger that is in fluid communication with the inline emulsifier and is located downstream of the inline emulsifier, wherein the heat exchanger is configured to reduce the temperature of the aqueous organic peroxide emulsion obtained from the at least one outlet of the inline emulsifier to a temperature at least 12°C lower than the SADT of the organic peroxide. Section 15. The system according to item 14, further comprising a pack-out unit located downstream of the heat exchanger.

Claims

1. A continuous process for generating organic peroxide emulsions, Step a) A step of supplying a pre-emulsification mixture to the inlet of an inline emulsifier, wherein the inline emulsifier comprises at least one mill head in a rotor-stator configuration, the pre-emulsification mixture comprises at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or less, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, and the pre-emulsification mixture is supplied to the inlet at a temperature at least 12°C lower than the SADT of the organic peroxide. A method comprising step b) transferring an aqueous organic peroxide emulsion from the outlet of the inline emulsifier to a heat exchanger downstream of the outlet of the inline emulsifier, wherein the heat exchanger reduces the temperature of the aqueous organic peroxide emulsion to a temperature at least 12°C lower than the SADT of the organic peroxide.

2. The method according to claim 1, wherein the preemulsory mixture of step a) is supplied to the inlet at a temperature 15°C to 35°C lower than the SADT of the organic peroxide.

3. The method according to claim 1, wherein in step b), the heat exchanger lowers the temperature of the organic peroxide emulsion to a temperature 15°C to 35°C lower than the SADT of the organic peroxide.

4. The method according to claim 1, further comprising step c) transferring the cooled aqueous organic peroxide emulsion of step b) to a pack-out unit located downstream of the heat exchanger.

5. The method according to claim 1, wherein the organic peroxide has a self-accelerated decomposition temperature (SADT) of 10°C or lower.

6. The method according to claim 1, wherein the organic peroxide is selected from peroxyesters, peroxydicarbonates, diacyl peroxides, or mixtures thereof.

7. The aforementioned organic peroxides are diisobutyryl peroxide (SADT 0°C), di-n-propyl peroxydicarbonate (SADT 0°C), diisopropyl peroxydicarbonate (SADT 5°C), di-n-butyl peroxydicarbonate (SADT 0°C), di-sec-butyl peroxydicarbonate (SADT 0°C), di(2-ethoxyethyl)peroxydicarbonate (SADT 10°C), di(2-ethylhexyl) peroxydicarbonate (SADT 5°C), 1,3-di(prop-2,2-diyl)benzene bis(neodecanoyl)peroxide (SADT 10°C), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (SADT 15°C), and 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate (SADT The method according to claim 1, selected from tert-amyl peroxyneodecanoate (SADT 20°C), cumyl peroxyneodecanoate (SADT 10°C), di-n-butyryl peroxide (SADT 25°C), tert-butyl peroxyneodecanoate (SADT 20°C), 1,1,3,3-tetramethylbutyl peroxypivalate (SADT 20°C); tert-amyl peroxypivalate (SADT 25°C), tert-butyl peroxypivalate (SADT 25°C), di(3,5,5-trimethylhexanoyl) peroxide (SADT 25°C), or a mixture thereof.

8. The method according to claim 1, wherein the preemulsion mixture contains 25 to 70% by weight of an organic peroxide based on the total weight of the preemulsion mixture.

9. The method according to claim 1, wherein the at least one protective colloid is selected from partially hydrolyzed (or saponified) polyvinyl acetate, polyvinylpyrrolidone, polyacrylate, cellulose, cellulose derivatives, starch, and starch derivatives.

10. The method according to claim 1, wherein the at least one emulsifier is omitted from the preemulsion mixture or is selected from nonionic, anionic, cationic, and amphoteric surfactants, and mixtures thereof.

11. The method according to claim 1, wherein the at least one antifreeze is selected from methanol, ethanol, isopropanol, (ethylene) glycol, propanediol, glycerol, and mixtures thereof.

12. The method according to claim 1, wherein the tip speed of the above or each mill head is 15 meters / second (m / s) to 50 m / s.

13. The method according to claim 1, wherein the residence time of the pre-emulsification mixture in the in-line emulsifier is 1 to 10 seconds.

14. A system for continuously generating organic peroxide emulsions, - At least one container for preparing and / or receiving a pre-emulsion mixture comprising at least one organic peroxide having a self-accelerated decomposition temperature (SADT) of 25°C or lower, at least one protective colloid, at least one antifreeze, water, and optionally at least one emulsifier, wherein the at least one container includes means for cooling and / or maintaining the pre-emulsion mixture at a temperature at least 12°C lower than the SADT of the organic peroxide, - An inline emulsifier comprising at least one inlet and at least one outlet, wherein the inline emulsifier comprises at least one mill head in a rotor stator configuration, the inline emulsifier is in fluid communication with the at least one container and is located downstream of the at least one container, and is configured to receive the pre-emulsion mixture at the at least one inlet at a temperature at least 12°C lower than the SADT of the organic peroxide, and A device comprising: a heat exchanger that is in fluid communication with the inline emulsifier and is located downstream of the inline emulsifier, wherein the heat exchanger is configured to reduce the temperature of the aqueous organic peroxide emulsion obtained from the at least one outlet of the inline emulsifier to a temperature at least 12°C lower than the SADT of the organic peroxide.

15. The system according to claim 14, further comprising a pack-out unit located downstream of the heat exchanger.

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