JP2010084127A - Bulk polymerization method by recirculation loop reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polymer, in particular, an adhesive based on a bulk polymerization method by using a recirculating loop reactor. <P>SOLUTION: The reactor is equipped with one or more mixers to mix feed stock with a polymerized material recirculating in the reactor. In another embodiment, one or more static mixers 28, 35, 40, 42, 50, and 60 and one or more planetary roller extruders (PRE) are used in combination mutually. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  This application is a continuation-in-part of US Application No. 11/845807, filed on August 28, 2007, US Provisional Application No. 60/841079, filed August 30, 2006, and 2006. Claim the benefit of US Provisional Application No. 60/85578, filed Oct. 23, 1987. The entire contents thereof are also included in the present application by reference.

  The present application relates to a continuous bulk polymerization process and related apparatus for preparing a polymer composition using a recirculating tubular loop reactor system, and in particular, a recirculating tubular with a planetary roller extruder (PRE). The present invention relates to a continuous bulk polymerization method for preparing a polymer composition such as an adhesive using a loop reactor and an apparatus related thereto.

  As a method for producing an adhesive by polymerization, a conventional bulk polymerization method is known. One of the methods uses a stirring tank type reactor, which is provided with a cooling jacket for removing heat generated by an exothermic reaction from the container. Such a conventional method is somewhat effective when the conversion rate is low. However, when the conversion rate is high and the viscosity is high, the substance easily adheres to the heat transfer surface, and therefore, the temperature cannot be controlled and the runaway reaction is likely to occur. Implementing at a low conversion does not provide an economic solution to this problem. It is necessary to remove the excess amount of monomer used in the operation at a low conversion rate from the polymer finally by a method such as drying or liquefaction. This is because it causes an increase.

  In one aspect of the invention, the polymerization process using a recirculating tubular loop reactor comprises: (a) activation of at least one monomer when heated to at least one initiator (the initiator is heated above its activation temperature). And (b) heating the mixture to at least the activation temperature of the initiator to produce a partially polymerized intermediate, and (c) a partially polymerized intermediate. Recirculating a portion of the reactor in the loop reactor; (d) directing the remaining polymerization intermediate to a stream removed from the loop reactor; and (e) starting the recirculating intermediate. Cooling to a temperature lower than the activation temperature of the agent; (f) mixing the cooled recycled intermediate with the added feedstock; and (g) not drying, liquefying, etc. Reactant (monomer) Including the optional step of removing from an intermediate and an optional step of applying a (h) above the remainder of the polymer intermediates reticulated material. According to a particular embodiment of the invention, the reaction may proceed with a small amount or absence of solvent. More specifically, the reaction may proceed when the solvent is less than about 5%, the solvent may be less than about 3%, and the solvent may be absent.

  In one embodiment of the present invention, a static mixer is used in the loop reactor to mix the feedstock and to mix the mixed feedstock and the recycled partially polymerized intermediate. In other embodiments, a planetary roller extruder is used in the loop reactor for this purpose.

  Static mixers are preferably used in loop reactors. Because a static mixer can accommodate a relatively large amount of reactants, a certain degree of polymer conversion is desired at a particular stage of the loop reactor, but it is necessary to obtain this certain degree of polymer conversion. This is because the residence time can be obtained. However, as the reactants polymerize in a static mixer, their molecular weight and melt viscosity increase. This can make it more difficult to circulate the polymerized material in the loop reactor. In one embodiment, the pressure in the reactor may be greater than about 200 pounds per square inch. In certain embodiments, the pressure may be greater than about 3,500 pounds per square inch and no greater than about 10,000 pounds per square inch. The pressure is affected by many factors such as tube diameter, intermediate product linear velocity, intermediate product viscosity, free volume, and static mixer configuration. According to one embodiment, the reactor may be operated at conditions that produce plug flow. Since plug flow reduces the variation in residence time, a product with a low gel content can be obtained with a more constant molecular weight and conversion.

  In one embodiment, it has been found desirable to replace one (or more) of the static mixers of the loop reactor with a dynamic mixer such as a twin screw extruder or planetary roller extruder (PRE). Dynamic mixers such as PRE often have less retention than static mixers, but because the reaction mixture is shredded by shear, the melt viscosity of the reaction mixture is lowered and the polymerized material is moved in the loop reactor. Make it easier. A dynamic mixer such as PRE is preferred because it efficiently mixes the reactants and reduces local deposition of unreacted material (monomer) in the reactants.

  Thus, another method of preparing a polymeric material using a loop reactor is to: (a) feed a feed containing at least one monomer and at least one activated initiator into an extruder, particularly a planetary roller. Introducing into a dynamic mixer installed in a reaction loop such as an extruder, (b) introducing a partially polymerized intermediate into the dynamic mixer to produce a polymerizable mixture, and (c) step (b) Heating the mixture from at least to the activation temperature of the initiator to polymerize the monomers in the feedstock with the polymerization intermediate, and (d) re-reacting the first part of the product of step (c) in the reactor. A step of circulating, (e) a step of directing the remainder of the product of step (c) to the stream removed from the loop reactor, and (f) a portion of the product of step (c) being recycled is added. Mixing with the prepared feedstock.

  In another embodiment, step (d) further comprises (g) cooling the product of step (c) to a temperature below the activation temperature of the initiator. In another embodiment, the method further includes (h) an optional step of further reacting the remainder of the partial polymer and further proceeding the polymerization before the removal in step (e). Furthermore, in another embodiment, the method further includes the step (i) of removing unreacted substances (monomer) from the remainder of the product by drying, liquefaction, etc. before the removal in step (e). . In another embodiment, the method further includes the step of (j) applying the polymerized product to the reticulated material.

  In another aspect of the invention, a combination of a recirculation loop reactor and a dynamic mixer, such as an extruder, in particular a planetary roller extruder, is used in a method for preparing a polymer material, the method comprising at least (a) at least Introducing a feedstock comprising one monomer and at least one initiator into a loop reactor in which the partially polymerized intermediate is recycled to form a polymerizable mixture; and (b) step (a ) At least to the activation temperature of the initiator to polymerize the monomer with the partially polymerized intermediate, and (c) the polymerized intermediate from step (b) above the activation temperature of the initiator. Circulating in the reactor while cooling to a low temperature, (d) mixing the cooled recycled polymerization intermediate from step (c) and the added feedstock, and mixing the monomer with the intermediate Further polymerization process (E) removing part of the further polymerized material from the loop reactor; (f) further reacting the polymerized polymer material in a planetary roller extruder to reduce unreacted substances (monomer); including. Furthermore, in another embodiment, the method further includes (g) a step of removing unreacted substances (monomer) by drying, liquefaction or the like. In another embodiment, the method further includes the step of (h) applying the polymerized product to the reticulated material.

  In another aspect, an adhesive composition that is the reaction product of at least one alkyl acrylate monomer containing at least one radical polymerization moiety and an initiator activated by heat is prepared according to the method described above. To manufacture. According to a particular embodiment of the invention, the composition has a molecular weight of about 1,500 to 1,000,000, more particularly about 200,000 to 400,000, as measured by gel permeation chromatography. Has a molecular weight.

  In another embodiment, the adhesive composition may be applied to the reticulated material using an applicator such as a slot die applicator, and the adhesive composition may be crosslinked after application.

1 is a schematic diagram of one embodiment of a method using the disclosed recirculation tubular reactor. FIG. It is a control diagram in the process of FIG. 1 is a schematic diagram of one embodiment of a method using a combination of the disclosed recirculating tubular loop reactor and a planetary roller extruder. FIG. FIG. 4 is a schematic diagram of another embodiment of a method using a combination of the disclosed recirculating tubular loop reactor and a planetary roller extruder.

  According to one embodiment, an adhesive (eg, an acrylic acid-based pressure sensitive adhesive) can be prepared by step 10 using the recirculating tubular reactor shown in FIG. As main raw materials, the first monomer 12 (for example, butyl acrylate, “BA”), the second monomer 13 (for example, vinyl acetate, “VA”), and the third monomer 14 (for example, acrylic acid, “AA”) , And thermal polymerization initiator 15 (for example, azodiisobutyronitrile, “AIBN”). The supply amounts of the monomers 12, 13, 14 and the initiator 15 are controlled by pumps 16, 17, 18, 19 such as double diaphragm pumps, respectively. What is necessary is just to control the flow volume of each pump 16, 17, 18, 19 by the frequency and / or stroke length of the piston which each pump 16, 17, 18, 19 does not show in figure, for example.

  However, the amount, quality, and type of monomer and initiator are determined by the desired end product, and the process shown in FIG. 1 using three types of monomers 12, 13, 14 and one type of initiator 15 is an example. Those skilled in the art will understand that it is only. You may add and use another initiator. One or more monomers may also be used. It is not necessary for the monomer and initiator to be pre-mixed before flowing into the feed stream 25, but they may be fed and mixed in a mixer on the loop.

  Monomers useful in the disclosed step 10 include, but are not limited to, alkyl acrylate monomers or mixtures of alkyl acrylate monomers, such as alkyl acrylate monomers containing an alkyl group and from about 2 to about 20, preferably 4-10. A mixture with a carbon atom is mentioned. Preferred alkyl acrylate monomers include 2-ethylhexyl acrylate, butyl acrylate (BA), isooctyl acrylate, isodecyl acrylate, and other monomers known to those skilled in the art and mixtures thereof. A divinyl monomer may be used to increase the molecular weight or the internal strength of the polymer skeleton, and may be applied as an embodiment of Step 10. Further, as one practical form, a divinyl monomer may be used up to 11% based on the weight of the acrylic polymer. Styrene, acrylic acid (AA), α-methyl styrene, tetraethylene glycol diacrylate, hydroxyethyl methacrylate, methyl methacrylate, ethyl acrylate, methyl acrylate, propyl acrylate are vinyl monomers that are suitably used in carrying out the predetermined embodiment. , Propyl methacrylate, hexyl acrylate, hexyl methacrylate, and vinyl acetate (VA).

  In one embodiment, the polymerization initiator 15 suitably used in the disclosed step 10 is any compound, composition, or compound and / or compound that releases a free radical when heated to the activation or decomposition temperature. Alternatively, any combination with the composition may be used. For example, useful initiators 15 include organic peroxides and azo compounds, including but not limited to lauroyl peroxide, t-butylperoxy (ethyl 2-hexanoate), benzoyl peroxide, 1,1 -Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, azo-diisobutyronitrile, and azobis-2-methylbutyronitrile. As another embodiment, any material or method may be used as the initiator 15 as long as it generates free radicals such as light (for example, ultraviolet rays), radiation, and chemical interaction.

  In one embodiment, initiator 15 may be used in the range of about 0.002 to about 2.0 wt%, particularly about 0.01 to about 1.0 wt%, based on the total monomer weight.

  The temperature of the polymerization reaction depends on the type of monomer used, the decomposition temperature of the initiator and / or the desired polymer product. For example, when AIBN is used as the initiator 15, the polymerization reaction may be performed at about 100 to about 140 ° C.

  According to one embodiment, the method converts at least 50% of the monomer to a polymer product, in particular, the method converts at least 95% of the monomer, more specifically, more than 99% of the monomer to the polymer product. Converted into These high conversions can be achieved with relatively short residence times as in other embodiments of the invention. For example, the residence time may be about 15 to 600 minutes, more specifically about 60 to 180 minutes.

  Returning to FIG. 1, the monomers 12, 13, 14 and the initiator 15 are thoroughly mixed in the first static mixer 28. According to one embodiment, the initiator 15 is fed to the first monomer 12 before flowing into the bulk feed stream 25 (indicated by the symbol F in FIG. 1 and expressed in units of weight per hour) and fed to the mixer 28. The mixture 24 may be prepared in advance. As a modification, the initiator 15 may be premixed with the maximum amount of monomer to be treated, which facilitates dispersion of the initiator.

In static mixer 28, there is sufficient residence time τ ₁ to thoroughly mix monomers 12, 13, 14 and initiator 15 to produce output stream 30. Here, when it is desirable to raise or lower the temperature of the feedstock as it passes through the mixer 28, a jacket 26 or other heat transfer device for heating / cooling is attached to the static mixer 28. May be. The residence time of the tubular reactor is generally represented by τ and is defined by the ratio between the free volume of the reaction vessel and the volume supply amount. Although the static mixer is located outside the loop in FIG. 1, those skilled in the art will appreciate that the mixer 28 may be incorporated into the loop.

From the overall mass balance of step 10 shown in FIG. 1, it can be said that the polymer product amount P is equal to the flow rate F of monomer and initiator. The feed stream 30 is at a flow rate F and is combined with a recirculation polymer stream 48 at a flow rate R to produce a polymer / monomer / initiator mixture stream 32. The polymer / monomer / initiator mixture stream 32 is fed to a static mixer 35. In this static mixer 35 there is sufficient residence time τ ₂ to mix the mixed stream 32 thoroughly. At the output destination of the container 35, an output flow 36 is obtained. A jacket 34 for heating and / or cooling may be attached to the static mixer 35 as required.

  The recirculation flow rate R is represented by the amount of fluid that has returned to the reaction loop (eg, the point where streams 30 and 48 merge). The recirculation ratio RR is represented by the ratio of R and P.

A gear pump 37 is connected to allow fluid to flow in the flow path between the flow 36 of the static mixer 35 and the inlet flow 38 to the static mixer 40. In static mixer 40 there is sufficient residence time τ ₃ to mix / react stream 38 to produce stream 41. The volume flow rate of the gear pump 37 is the sum of F and R.

According to one embodiment, heating the stream 38 in the mixer 40 to a temperature above the activation temperature of the initiator can initiate the radical polymerization reaction and at least partially convert the monomer to a polymer. (e.g., stream 41 is degree of conversion is _{X 1).} In this case, a jacket 39 for heating / cooling the streams 38 and 41 is attached to the mixer 40.

The degree of partial conversion of liquid monomer to adhesive polymer is generally expressed as _Xn and is determined as follows.
_{X n = 1- (C n /} C 0)
Here, X _n includes a numerical value between 0 and 1. For example, X ₁ is obtained as follows:
X ₁ = 1− (C ₁ / C ₀ )
Where C ₀ is the concentration of the reactant (monomer) in stream 32 and C ₁ is the concentration of the reactant (monomer) in stream 41. Similarly, X ₂ is determined in the following manner,
_{X 2 = 1- (C 2 /} C 0)
Where C ₂ is the concentration of reactant (monomer) in stream 44. Similarly, X ₃ is determined in the following manner,
X ₃ = 1− (C ₃ / C ₀ )
Where C ₃ is the concentration of the reactant (monomer) in stream 50.

For example, when BA, VA, and AA are reacted with AIBN using Step 10 to produce an acrylic acid-based PSA, the degree of conversion X ₁ is about 0.8, the degree of conversion X ₂ is 0.95, and the degree of conversion X ₃ becomes 0.99. One skilled in the art will appreciate that the actual degree of conversion will vary depending on the flow rates F, R, P and the containers 28, 35, 40, 42, 50, 60 and other factors.

Stream 41 from static mixer 40 flows into the static mixer 42, there is sufficient residence time tau ₄ to obtain the static mixer 42, the monomer to the polymer by continuously converting degree of conversion X ₂ . The vessel 42 is fitted with a jacket 43 to obtain a means for heating / cooling the stream 41. The flow 44 has a flow rate composed of the sum of F and R, and is divided into a flow 45 at a flow rate P and a flow 46 at a flow rate R. The volume of this split flow is controlled by a gear pump 51, and the gear pump 51 is connected so that fluid flows through the flow path between the flows 50 and 52. Here, P is a volume flow rate of the gear pump 51. Instead of the gear pump 51, a three-way valve (not shown) may be installed at a point where the flow 45 branches from the flow 46, and the recirculation flow rate R may be controlled by the three-way valve. A three-way valve may be used together with the pump 51. Stream 45 flows into a static mixer 60, the monomers a further reacted and the degree of conversion X ₃ in. The container 60 has a sufficient residence time tau _6, there is a heating / cooling means for varying the flow 45 degree of conversion X ₂ at a flow rate P to the flow 50 of the degree of conversion X ₃ of the flow rate P (e.g., a jacket 58) .

The loop process cycle with the tubular reactor can be terminated with a flow 46 entering the static mixer 50 at a flow rate R, where the residence time sufficient to cool the entire flow to a temperature below the starting temperature. there is a τ _5. While substantially maintaining the degree of conversion X _2, outlet flow 48 flows out from the container 50. The static mixer / cooler 50 is fitted with a jacket 54 to facilitate cooling the stream 46.

According to one embodiment, the total loop residence time is the sum of τ ₂ , τ ₃ , τ ₄ , and τ ₅ . For example, if the polymer mixture is recirculated in a loop about 3 times per hour, the total loop residence time is about 20 minutes. In other embodiments, the gear pumps 37, 51 may be adjusted so that the total loop residence time is about 1 to about 4 recirculations per hour. It will be appreciated by those skilled in the art that the total residence time will depend on the desired product and will vary depending on the type of desired polymer ultimately obtained and the monomers and initiator used.

  According to one embodiment, product stream 52 (eg, final product) may be applied to the reticulated material using an applicator such as a slot die applicator. However, those skilled in the art will appreciate that the recirculating tubular reactor process 10 described herein can be used to produce a variety of polymeric materials for a variety of different applications. For example, the step 10 described here is performed using a release agent, a primer coating, a non-PSA adhesive, a sealant, a caulking material, an acrylic hybrid PSA, and a non-PSA paint such as a urethane acrylic resin, an epoxy acrylic resin, or a styrene acrylic resin. You may use for manufacture.

  In a static mixer such as a continuous tube reactor, the supply of reactants and the withdrawal of products are performed continuously at the same time. The reactant flows in from one end of the reaction vessel, and the product flows out from the other end. During this period, the composition of the mixture during the reaction changes continuously. Heat transfer to and / or from the tubular reaction vessel can be performed by a jacket or shell and tube design. In a static mixer, the liquid medium self-mixes through a series of splitting and recombination. Since static mixers have no moving parts, maintenance and operating costs can be significantly reduced. The energy required for mixing is obtained by pumps 37 and 51 that cause fluid to flow into the container. In the tubular reaction vessel, the flow of the fluid passing through the reaction vessel is actually in order, and some elements of the fluid do not precede and other elements in front or behind do not mix.

  The gear pumps 37 and 51 described here include a housing (not shown) that defines a cavity of the pump, a pair of gears (not shown) that are rotatably arranged in the cavity of the pump, A mounting shaft (not shown) extending in the axial direction of the gear provided in the gear and a bearing means (not shown) for rotatably supporting the shaft of the gear are provided. The bearing means includes a radial surface disposed opposite the gear and a pair of axial openings for rotatably supporting the shaft of the gear. The gear pumps 37 and 51 are driven by rotating the drive shafts of the pumps 37 and 51 from the outside with a motor (not shown). Since material passes through the gear pumps 37, 51, rotation by or to the gear is directly proportional to the amount of material that has passed through the gear. Therefore, the gear functions as a precise device for measuring the amount of intermediate product flowing through the flow path. The number of gear mechanisms varies with the size of the gear or the axial thickness of the gear.

  The containers 28, 35, 40, 42, 50, 60 described here are used for two purposes: (1) to raise and / or lower the temperature of the fluid passing through them; The purpose is to mix the fluids that pass through. Vessels 28, 35, 40, 42, 50, 60 are “residence time reactors”, which provide additional time for the reactants to reach the activation temperature and further mix the reactants. Because it becomes possible to do.

  Here, it will be understood by those skilled in the art that the containers 28, 35, 40, 42, 50, 60 may be increased or decreased in the step 10. For example, the containers 40 and 42 may be separate containers or connected to form a single container.

  For example, in the bulk feed stream 25, the BA monomer stream 12 has a flow rate of 6.83 kg / hr, the VA monomer stream 13 has a flow rate of 0.6 kg / hr, the AA monomer stream has a flow rate of 68 g / hr, and the AIBN initiator 15 It is contained at a flow rate of 2 g / hr. In this case, the product stream 52 is an acrylic acid-based PSA having a flow rate P of 7.5 kg / hr.

In the static mixer / heater 35, the low viscosity monomer / initiator will be mixed with the high viscosity polymer. At 70 ° C., the initiator (AIBN) and monomer coexist but do not react with each other. Here, the recycle stream 48 0.042m ³ / ^hr, and 900kg / m 3, 700Pas, the flow ^{30 0.00833m 3 / hr, 900kg /} m 3, 0.01Pas, the flow 32 0.05 m ³ / hr, 900 kg / m ³ , 583 Pas. As shown in FIG. 2, the static mixer / heater 35 includes CSE-X / 8, DN49.5, 18 elements, Δp = about 21 bar, shear rate 10.5 s ⁻¹ , residence time 104 seconds, length The thing of about 900 mm is used.

  In one embodiment, the gear pump 37 is capable of extruding a polymer having a viscosity of about 1,000 Pas at a pressure of about 50 bar at about 50 kg / hr. The flow is controlled with the accuracy of the pump 37 (a flow meter may optionally be added). In one embodiment, the recirculation rate R is about 1 to about 5 times the feed rate F.

The homogenized mixture 38 consisting of monomer / polymer / initiator is heated in a mixer / heat exchanger 40. The polymerization reaction is initiated by raising the temperature from about 70 ° C to about 120 ° C. The generated heat is partially absorbed by the bulk polymer and increases by, for example, about 20 to about 40 ° C. due to the polymerization reaction. A Marotherm® L heat transfer fluid may be supplied to the jacket 39 of the reaction vessel at, for example, about 120 ° C. for heating. Once the reaction has begun, the reaction vessel jacket 39 is used as a cooler for temperature control. The mixture (stream 41) has 0.005 m ³ / hr, 900 kg / m ³ , 700 Pas, Cp (heat capacity) of 2,300 J / kg / K, and λ (latent heat) of 0.15 W / m / K. As shown in FIG. 2, the mixer / heat exchanger 40 has CSE-XR, DN80, 8 elements, Δp = about 5 bar, shear rate 4 s ⁻¹ , residence time 170 seconds, length about 750 to 1,100 mm. Something is used.

  Marlotherm (R) LH is a high-performance synthetic organic heat transfer medium that is used in a forced circulation unpressurized heat exchange mechanism in a closed system at an operating temperature of about 0 to about 280 ° C. in a liquid state. . Marlotherm (R) heat transfer fluid is provided by Sasol Olefines & Surfactants (Marl, Germany). The reaction temperature is set to about 120 ° C. so as to be suitable for the AIBN initiator. However, when different thermal polymerization initiators or a mixture of thermal polymerization initiators are used, they are set to different reaction temperatures.

The container 42 is a double-jacket mixer, and a further residence time can be obtained and mixing can be further performed in order to improve the production amount and product quality. The polymer streams 41, 44 are kept constant, for example at 120 ° C. Mixture (stream ^{44), 0.05m 3 / hr, 900kg /} m 3, the 700Pas. As shown in FIG. 2, the mixer / heat exchanger 42 includes CSE-X / 4, DN80, 15 elements, Δp = about 3 bar, shear rate 1.6 s ⁻¹ , residence time 390 seconds, length about 1, A 200 mm one is used.

By cooling the monomer / polymer / initiator mixture from about 120 ° C. to about 70 ° C. by vessel 50 in the recycle loop, further polymerization can be reduced or suppressed. For example, Marlotherm® L is supplied to the jacket 54 of the container 50 at about 60 ° C., and cooling is performed in the container 50 using this. The mixture (stream 48) would be 0.005 m ³ / hr, 900 kg / m ³ , 700 Pas, Cp 2,300 J / kg / K, and λ 0.15 W / m / K. As shown in FIG. 2, the mixer / heat exchanger 50 is CSE-XR, DN80, 18 elements, Δp = about 11 bar, shear rate 4 s ⁻¹ , residence time 390 seconds, length about 1,600 mm. Used.

Vessel 60 is a double jacket mixer and further obtain the residence time, to further perform the mixing, degree of conversion increases from X ₂ to X _3. The gear pump 51 controls the flow rate P to be 7.5 kg / hr. Mixture (stream ^{52), 0.00833m 3 / hr, 900kg /} m 3, the 700Pas. As shown in FIG. 2, the mixer / heat exchanger 60 has CSE-X / 4, DN40, 15 elements, Δp = about 6 bar, shear rate 2.7 s ⁻¹ , residence time 265 seconds, length about 700 mm. Something is used.

  As shown in FIG. 2, a flow rate, temperature, pressure, container liquid level, melt viscosity and power sensor reader, and various control systems are provided so that the operator can easily control the process. Other process control features include pressure-resistant piping, pressure-resistant valves, process start mechanisms, process stop mechanisms, three-way valves, polymer concentration and residual monomer measurement mechanisms, and the like.

  In one embodiment, the polymer product (e.g., acrylic pressure sensitive adhesive (PSA)) is manufactured using a planetary roller extruder (PRE) by step 110 shown in FIG. Although the PRE is shown in FIG. 3, other dynamic mixers and extruders may be used instead or in combination with the PRE. As main raw materials, the first monomer 120 (eg, butyl acrylate, “BA”), the second monomer 130 (eg, vinyl acetate, “VA”), and the third monomer 140 (eg, acrylic acid, “AA”) , And a thermal polymerization initiator 150 (eg, azodiisobutyronitrile, “AIBN”). The supply amounts of the monomers 120, 130, and 140 and the liquid initiator or the liquid solid initiator 150 are controlled by pumps 160, 170, 180, and 190 such as a double diaphragm pump, respectively. The flow rate of each pump 160, 170, 180, 190 is controlled by, for example, the frequency and / or stroke length of each pump 160, 170, 180, 190.

  The amount, quality, and type of monomer and initiator depend on the desired end product, and the process shown in FIG. 3 uses three types of monomers 120, 130, 140 and one type of initiator 150. One skilled in the art will appreciate that this is only an example. The number of monomers and initiators is used depending on the product.

  Monomers 120, 130, 140 and polymerization initiator 150 useful in the disclosed step 110 include those previously described in the disclosed step 10.

  In one embodiment, when initiator 150 is used in the range of about 0.002 to about 2.0 wt%, particularly about 0.01 to about 1.0 wt%, based on the total weight of the feed monomer. Good.

  In FIG. 3, the reactor loop labeled 110 is used, for example, to produce an acrylate polymer product. Monomers 120, 130, 140 and liquid initiator or liquid solid initiator 150 are fed by pumps 160, 170, 180, 190, respectively, to produce bulk feed stream 200 at flow rate F (shown in FIG. 3).

  Feed stream 200 is fed to a first planetary roller barrel 270 where it is mixed with recycled polymer stream 370 at a recirculation flow rate R (shown in FIG. 3) and heated to about 25 to about 240 ° C. to effect a radical reaction step. Let it begin. In this embodiment, mixture 300 is fed to barrel 280 of the second planetary roller extruder and barrel 290 of the third planetary roller extruder, where the final residual monomer concentration of polymer stream 300 is minimized at a preset residence time. To. As with the feed stream 200, the injection of each monomer 120, 130, 140 may be anywhere along the length of the PRE, but it is fed by an injection valve inserted into the spray ring before the first PRE barrel. Most preferred. The injection valve may be inserted into the dispersion ring before or after any PRE barrel, or may be inserted into a side port directly connected to the barrel, or another internal or external supply mechanism. Feed of regenerated polymer stream 370 may take place anywhere along the length of the PRE, but most preferably uses a circulation port on the side of the PRE barrel. Also, the injection valve may be specially designed to handle such viscous material in the same ring used for monomer addition, and the regenerated polymer stream 370 may be fed from any of the injection valves, You may supply using an external supply mechanism. One skilled in the art will appreciate that the use of three PRE barrels is an example, and barrels may be added or reduced depending on the desired product. The temperature is always controlled within the regions 270, 280, 290 and maintained, for example, by a heating / cooling medium flowing through the barrel walls 220, 230, 240 as well as the central hole 250 of the main shaft 260. In one embodiment, the temperature of the polymer process is maintained at a temperature below 240 ° C. (eg, the lowest decomposition temperature of acrylic polymers and copolymers).

The degree of partial conversion of liquid monomer to adhesive polymer is generally expressed as Y _n and is determined in step 110 as follows.
Y _n = 1− (C ′ _n / C ′ ₀ )
Here, Y _n includes a numerical value between 0 and 1. For example, Y ₁ is obtained as follows:
Y ₁ = 1− (C ′ ₁ / C ′ ₀ )
Where C ′ ₀ is the concentration of the reactant (monomer) in the mixed stream 200 and 370 and C ′ ₁ is the concentration of the reactant (monomer) in the stream 300. Similarly, Y ₂ is determined in the following manner,
Y ₂ = 1− (C ′ ₂ / C ′ ₀ )
Where C ′ ₂ is the concentration of the reactant (monomer) in stream 350. Similarly, Y ₃ is determined in the following manner,
Y ₃ = 1− (C ′ ₃ / C ′ ₀ )
Here, C ′ ₃ is the concentration of the reactant (monomer) in stream 400.

Stream 300 has a degree of conversion Y ₁ and the flow rate is the sum of stream F from the feed and recycled material stream R. Gear pump 310 is coupled so that fluid flows in the flow path between flow 300 and flow 320 to static mixer 340. The volume flow rate of pump 310 is the sum of F and R, but this need not be the case. Those skilled in the art can vary the flow rate of the pump 310 not only according to the compression effect adjustable in the loop reactor, but also according to the shredding effect caused by shear generated in the PRE and other volume changes associated with the mixing of the reactants. You can understand. In general, the purpose of the pump 310 is to minimize flow rate fluctuations. The static mixer 340 is provided with a jacket 330 and / or other heat exchange device as means for heating / cooling the stream 320.

Stream 350 has a degree of conversion Y ₂ and is split into a flow 360 at a flow rate P and a flow 370 at a flow rate R. The amount of diversion is controlled by a pump 410, which is connected so that fluid flows through the flow path between the streams 400 and 420. The volume flow rate of the pump 410 is represented by P. Supplying a stream 360 to a static mixer 390, the monomers reacted further to the conversion of Y ₃ in. Static mixer 390 is capable of heating / cooling (for example, provided with a jacket 380), changing the degree of conversion _{Y 2} streams 360 flow P to degree of conversion _{Y 3} streams 400 flow P.

  In this way, the incorporation of at least one PRE in the loop reactor makes the previously described reactor and process more versatile. If the mixer is only a static mixer, mixing will depend on the linear speed of the polymer material, and higher speeds will require sufficient shear to effectively mix. With a dynamic mixer, the mixing efficiency is less dependent on the linear speed of the polymer material. Thus, the selective use of PRE in a loop reactor increases the diversity of mixing and heat exchange throughout the reactor mechanism.

  In FIG. 4, an alternative process is represented by 120 and can be used to manufacture acrylic polymer products. Monomers 500, 510, 520 and liquid initiator or liquid solid initiator 530 are fed by pumps 540, 550, 560, and 570, respectively, to produce bulk feed stream 580 (symbol F in FIG. 4).

  In one embodiment, stream 580 is at flow rate F and is combined with flow rate R of recycled polymer stream 740 to produce a polymer / monomer / initiator mixed stream 590. The polymer / monomer / initiator mixture stream 590 is fed to a static mixer 600 designed to thoroughly mix the mixture stream 590. The discharge of the static mixer 600 results in an output stream 620. A jacket 610 for heating and / or cooling may be attached to the static mixer 600 as needed. A gear pump 630 is coupled for fluid flow in the flow path between the flow 620 of the static mixer 600 and the inlet flow 640 to the static mixer 650. Static mixer 650 is designed to mix / react stream 640 to produce stream 670. The volume flow rate of the gear pump 37 is about the sum of F and R, but as described above, the flow rate may be changed.

Partial conversion degree to adhesive polymer of liquid monomer, typically, is determined as follows in step 120 is represented by Z _n.
Z _n = 1− (C ″ _n / C ″ ₀ )
Here, Z _n includes a numerical value between 0 and 1. For example, Z ₁ is obtained as follows:
Z ₁ = 1− (C ″ ₁ / C ″ ₀ )
Where C ″ ₀ is the concentration of reactant (monomer) in stream 590 and C ″ ₁ is the concentration of reactant (monomer) in stream 670. Similarly, Z ₂ is determined in the following manner,
Z ₂ = 1− (C ″ ₂ / C ″ ₀ )
Where C ″ ₂ is the concentration of the reactant (monomer) in stream 700. Similarly, Z ₃ is determined as follows.
Z ₃ = 1− (C ″ ₃ / C ″ ₀ )

Where C ″ ₃ is the concentration of the reactant (monomer) in stream 840.

As before, the inlet stream 640 is heated in the static mixer 650 to a temperature above the activation temperature of the initiator. This can initiate a radical polymerization reaction, at which time the monomer is at least partially converted to a polymer (eg, stream 670 has a degree of conversion Z ₁ ). A jacket 660 and / or other heat exchange device is provided in the static mixer 650 to obtain the heating / cooling means of the streams 640, 670.

Stream 670 discharged from static mixer 650 is fed to static mixer 680. Static mixer 680, there is sufficient residence time such that the flow 700 monomers continuously converted to polymer is the degree of conversion Z _2. The static mixer 680 is provided with a jacket 690 and / or other heat exchange device to provide a means for heating / cooling the streams 670, 700. Stream 700 is split into product flow P stream 750 and flow R recirculated stream 710. The amount of product removed from the reactor loop 120 is controlled by a pump 850 that is coupled to fluid flow in the flow path between streams 840 and 860. The volume flow rate of the pump 850 is represented by P. Stream 710 is fed to static mixer 720 to further proceed with the monomer reaction. The static mixer 720 has sufficient residence time and cooling function to change the flow rate R flow 710 to a flow 740 at a temperature lower than the activation temperature, and to achieve a conversion Z ₄ (where C " ₄ is the concentration of reactant (monomer) in stream 740).

The degree of conversion _{Z 2} stream 750 is supplied to the first planetary roller barrel 760, to maintain the radical reaction step and heated to about 25 to about 240 ° C.. The mixture is fed to the second planetary roller barrel 770 and the third planetary roller barrel 780 where the final residual monomer concentration in the polymer stream 840 is minimized at a preset residence time. The temperature in the barrels 760, 770, 780 is accurately controlled by flowing a heating / cooling medium not only in the central hole 830 of the main shaft 820 but also in the vicinity of the meshing surfaces or in the barrel walls 790, 800, 810. In the polymer process, the temperature is maintained below the decomposition temperature of the polymer material (eg, 240 ° C. for butyl acrylate). The planetary roller barrels 760, 770, 780 change the flow 750 at the conversion rate Z _{2 at} the flow rate P to the flow 840 at the conversion rate Z _{3 at} the flow rate P.

  According to one embodiment, the product streams 52, 420, and 860 from each step 10, 110, 120 may be applied to the reticulated material by an applicator such as a slot die applicator, other application methods or doctor methods.

  Those skilled in the art will appreciate that the steps 10, 110, 120 described herein can be used to make various polymeric materials for a variety of different applications. For example, it can be used for the production of release agents, primer coatings, adhesives, PSA, non-PSA, sealants, caulking materials, architectural coatings, and the like. Furthermore, these adhesives and paints may be polymerized with various chemical substances. In particular, the chemical substances include, but are not limited to, acrylic monomers, polyols, isocyanates, vinyl materials, epoxies, and the like.

  According to one embodiment, the polymer composition produced in steps 10, 110, 120 may be crosslinked using electron beam or ultraviolet energy, which is a known method. For example, an appropriate ultraviolet accelerator may be added to crosslink the polymer material using ultraviolet energy (for example, a photoinitiator such as a peroxide). It is desirable to add UV accelerators or actinic radiation initiators in the recirculation tubular reactor process without exceeding the scope of the present invention.

  If more viscosity and / or adhesion is required, resins, oils and / or other additives may be added to the reactants and / or final product. If color or other properties need to be changed, pigments, dyes, fillers, antidegradants, and / or other additives may be added to the reactants and / or final product.

  General tackifying resins include, but are not limited to, partially or wholly hydrogenated wood, gum, or tall oil rosin, esterified wood, gum, or tall oil rosin, alpha and beta pinene resins, And polyterpene resins. The resin is supplied in a solid state or in a liquid state. For example, the resin is supplied in a solution, a dispersion, and / or a molten state, although not limited to the following. Common antioxidants include antioxidants, UV absorbers, and UV stabilizers. Common crosslinking agents include peroxides, ion-containing materials, thermally active resins, isocyanates, ultraviolet light, and / or electron beam active curing agents. Common colorants include titanium dioxide and other various metal pigments. When the use of a solvent is desired, common solvents include liquid carboxylates such as ethyl acetate and n-butyl acetate, ketones such as acetone, dimethyl ketone and cyclohexanone, benzene, toluene, and xylene. Aromatic hydrocarbons, petroleum fractions having a boiling point of about 50 to 150 ° C., especially about 60 to 100 ° C., liquid aliphatic compounds and cycloaliphatic hydrocarbons such as cyclohexane, dioxane, tetrahydrofuran, di-t-butyl ether, etc. Or a mixture thereof. In particular, solvents useful for the polymer compositions in the present invention include ethyl acetate, cyclohexane, and mixtures of acetone and petroleum ether (eg, having a boiling point of about 60 to about 95 ° C.).

  It is particularly advantageous to apply a polymer material to a reticulated material using a slot die as compared to conventional application methods such as roll-over-roll, reverse-roll, knife-over-roll, and the like. At the reticulated coating speed, using the conventional method, the viscosity is limited to a polymer material having a viscosity of 40,000 cPs or less, and is difficult to apply to a high solid polymer material. On the other hand, when the slot die coating technique is used, the coating speed can be about 1,000 m / min or more, particularly when used with a high solid polymer material produced by a process using a recirculation tubular reactor.

  The polymer produced by the disclosed method and the reticulated substrate are integrated to produce a reticulated product, but any known substrate may be used by selecting the substrate according to the desired use of the reticulated product. The base material may or may not have been subjected to an appropriate chemical or physical surface treatment on the coated surface, or an appropriate physical treatment or paint for preventing adhesion may be applied to the opposite side of the coated surface. It may or may not be applied. Representative examples include crepe or non-crepe release paper, polyethylene, polypropylene, uniaxial or biaxially oriented polypropylene film, polyester, polyamide, PVC, release paper or other film, and also foam materials, fabrics, knitted fabrics, and polyolefins Examples thereof include a net-like nonwoven fabric.

  Although the disclosed polymerization method has been described using specific aspects and embodiments, variations based on the contents of this specification are possible. The disclosed polymerization process also includes all such variations. In particular, although the manufacture of adhesives has been described herein in the embodiments, those skilled in the art will appreciate that the present invention is applicable to the manufacture of general polymeric materials.

Claims (15)

The following steps a) to f)
a) Producing a reaction mixture by feeding a feedstock containing at least one monomer and at least one activation initiator to a recirculation loop reactor in which the partially polymerized material circulates. And a process of
b) polymerizing the reaction mixture by heating to at least the activation temperature of the initiator to produce a polymerization intermediate;
c) recycling a portion of the polymerization intermediate in the loop reactor and directing the remainder of the polymerization intermediate to a removal stream;
d) cooling the recycled portion of the intermediate to a temperature lower than the activation temperature of the initiator;
e) mixing the cooled recirculated portion of the intermediate with the feedstock;
f) A method comprising a step of further reacting the remainder of the polymerization intermediate to produce a polymerization product.   The method according to claim 1, wherein the reaction loop includes a plurality of static mixers, and at least one of the static mixers has a heat exchange function.   3. The method of claim 2, wherein the loop comprises a planetary roller extruder and feeds the feedstock to the planetary roller extruder.   4. The method of claim 3, wherein the residence time in the loop reactor or the monomer is about 1-5 recycles / hour.   5. A method according to claim 4, wherein the amount of recycle part of the polymerization intermediate and the remainder thereof is controlled by a gear pump provided in the removal stream.   The method of claim 1, wherein the reaction mixture contains less than about 5% solvent.   The method of claim 6, wherein the pressure in the recirculation loop reactor is greater than about 200 pounds per square inch.   The method of claim 7, wherein the pressure in the loop reactor is from about 3,500 pounds per square inch to about 10,000 pounds per square inch or less.   9. The method of claim 8, wherein the polymerization intermediate is circulated as a plug flow through the recycle loop reactor.   The method of claim 6, wherein the polymerization product has a molecular weight of about 1,500 to 1,000,000.   The method of claim 10, wherein the polymerization product has a molecular weight of about 200,000 to 400,000.   The method of claim 1 wherein the method converts at least 50% of the monomer to a polymerization product.   13. The method of claim 12, wherein the method converts at least 95% of the monomer to a polymerization product.   The method of claim 3, wherein the monomer resides in the recycle loop reactor for about 15 to 600 minutes. 4. The method of claim 3, wherein the polymerization product is an adhesive composition, and the adhesive composition contains a polymerization reaction product of at least one alkyl acrylate monomer.

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