TW201737990A - Air filters comprising polymeric sorbents for aldehydes - Google Patents

Abstract

An air filter including a filter support that supports polymeric sorbent particles. The polymeric sorbent is the reaction product of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound.

Description

Air filter containing a polymeric sorbent for aldehydes

What is often desired is the removal of gaseous substances such as, for example, formaldehyde from the air.

Broadly speaking, disclosed herein is an air filter comprising a filter holder comprising polymeric sorbent particles. The polymeric sorbent is the reaction product of a divinylbenzene/maleic anhydride precursor polymeric material and a nitrogen containing compound. These and other aspects will be apparent from the following detailed description. However, this broad disclosure should not be construed as limiting the subject matter of the claim, whether it is within the scope of the patent application for the initial application, or within the scope of the patent application filed during the revision or application process. .

1‧‧‧Air filter

10‧‧‧Filter bracket/filter bracket layer

11‧‧‧air inlet

12‧‧‧ air outlet

13‧‧‧ Internal

15‧‧‧Hive

21‧‧‧ solid part

22‧‧‧through hole

23‧‧‧ upstream side

24‧‧‧ downstream side

28‧‧‧Adhesive

40‧‧‧Filter media

43‧‧‧ first major surface

44‧‧‧Second major surface

60‧‧‧Filter mask respirator/respirator mask

63‧‧‧Folding line

70‧‧‧ Peripheral framework

100‧‧‧ sorbent particles

1 depicts a portion of an exemplary air filter that includes a filter holder that contains sorbent particles as disclosed herein.

Figure 2 depicts a portion of another exemplary air filter.

Figure 3 depicts a portion of another exemplary air filter.

Figure 4 depicts a portion of another exemplary air filter.

Figure 5 depicts a portion of another exemplary air filter.

6 depicts an exemplary respirator including a filter holder comprising sorbent particles as disclosed herein.

Figure 7 discloses another exemplary respirator.

Figure 8 discloses a framed pleated air filter comprising a filter holder comprising sorbent particles as disclosed herein.

Figure 9 shows the formaldehyde capture efficiency data for the working examples and comparative examples.

Figure 10 presents formaldehyde capture efficiency data for the working example of Figure 9, where the x-axis is normalized by the mass of sorbent per unit area.

Figure 11 presents formaldehyde capture efficiency data for another working example and comparative example in which the x-axis is normalized by the mass of sorbent per unit area.

Figure 12 presents formaldehyde capture efficiency data for another working example and comparative example in which the x-axis is normalized by the mass of sorbent per unit area.

vocabulary

The term "air filter" means any device or device that presents a polymeric sorbent supported herein by a filter holder to air (eg, a moving air stream) such that gaseous species can be removed from the air. . The term "filter support" means that the sorbent particles can be held and presented to, for example, a moving air stream, but does not necessarily perform any structure for filtering microscopic particles from moving air. The term "filter media" means a filter holder that is capable of filtering microscopic particles. "micro The microscopic "particles" have particles having an average diameter (or equivalent diameter, in the case of non-spherical particles) of less than 100 microns. "Fine" particles are particles having an average diameter or equivalent diameter of less than 10 microns.

The terms "polymeric sorbent" and "porous polymeric sorbent" refer to a porous polymeric material that sorbs a gaseous substance such as, for example, an aldehyde. Porous materials such as polymeric sorbents can be characterized based on, for example, their pore size. The term "micropores" means a pore having a diameter of less than 2 nanometers. The term "mesopores" refers to a hole having a diameter in the range of 2 to 50 nm. The term "macropores" refers to a hole having a diameter greater than 50 nanometers.

The term "upstream" applies to the case where the filter is exposed to moving air and refers to the direction in which the moving air encounters the filter; "downstream" refers to the direction in which the filtered air exits the filter.

The term "netting" refers to a filter holder that contains relatively few layers (five layers or less, often one layer) of solid material (eg, filaments).

The term "fibrous web" refers to a filter holder comprising a plurality of layers (eg, more than five layers) of fibers.

The term "meltblown" means a fiber (and resulting fibrous web) formed by extruding a stream of molten polymer into a stream of concentrated high velocity air, the concentrated high velocity air stream being positioned adjacent to the extrusion orifice The blast hole is introduced. Those of ordinary skill will appreciate that meltblown fibers and webs will characteristically exhibit features and characteristics that distinguish such fibers and webs from other types of webs (eg, molecules that make up the fibers) The difference in orientation is as shown, for example, by optical properties such as birefringence, melting behavior, and the like.

The air filter 1 shown in the general representation of Fig. 1 is disclosed herein. The air filter 1 can expose the polymeric sorbent particles 100 disclosed herein to air, such as a moving air stream (wherein the general direction of the gas flow is in the exemplary embodiment by the square arrows in Figure 1 and other figures) Indicative), any device or device that allows gaseous species (such as aldehydes, such as formaldehyde) to be removed from the air.

The air filter 1 comprises at least one filter holder 10. The filter holder 10 can support any structure of the sorbent particles 100 in such a manner that the sorbent particles 100 are exposed to the air while retaining the sorbent particles such that the sorbent particles do not pass through even if the air moves. Move the air to remove it. If the air moves, it may encounter individual sorbent particles when in the form of a laminar flow or when in the form of a turbulent flow, or may transition between flowing states, for example, as it passes through a collection of sorbent particles. . In one general type of embodiment, the filter holder 10 can take the form of a substrate on which the sorbent particles 100 are provided (e.g., attached to its major surface) and, for example, a moving air stream can traverse Across the substrate, as shown in the general representation in FIG. In some embodiments of this type, the filter holder 10 can hold the sorbent particles 100, for example, by attaching (eg, adhering) the sorbent particles to the filter holder. In another general type of embodiment, the filter holder 10 can hold the sorbent particles 100, for example, by mechanically retaining the sorbent particles within the filter holder, as shown in the general representation of FIG. (In other words, in such embodiments, the sorbent particles may not necessarily be attached to the filter holder, but the filter holder may physically obstruct the removal and removal of sorbent particles from the filter holder.) In some implementations In one example, a combination of mechanical retention and attachment (e.g., bonding) of the sorbent particles to the filter holder can be employed.

In some embodiments, the air filter 1 can be a filter holder 10 that includes sorbent particles 100 (eg, can consist essentially of it) (eg, a separate piece of such a filter holder can be assembled to, for example, indoor air In the purifier). In other embodiments, the air filter 1 may include other layers (other than the at least one filter holder 10) as desired for any purpose, and/or may additionally include any other auxiliary components such as, for example, a perimeter frame, Or a plurality of reinforcing or stabilizing members, one or more outer casing members, and the like. Various specific illustrative embodiments and arrangements are discussed in detail herein later.

As noted with reference to Figure 1, in some embodiments, the filter holder can take the form of a substrate (which may be gas impermeable or gas permeable), the sorbent particles 100 being disposed (e.g., attached) at On the main surface of the substrate. An air filter of this type may comprise, for example, a planar substrate with sorbent particles attached to its major surface; a hollow tube in which sorbent particles are attached to its inner surface; or a flow channel An array provided by a stacked or nested microstructured substrate (eg, of the general type described in U.S. Patent No. 7,955,570 to Insley) wherein sorbent particles are attached to the inner surface of the flow channel; . In some embodiments, the sorbent particles 100 can be provided on the surface of the substrate at least substantially in a single layer (eg, as shown in FIG. 1), except as may be statistically, for example, on any industrial scale deposition process. This kind of accidental stacking occurs in the middle.

Referring to Figure 2, the term filter holder broadly encompasses any container that is designed to hold the sorbent particles 100 therein and includes: at least one air inlet 11 for allowing air to enter the interior 13 of the container; And at least one air outlet 12 to allow The treated air leaves the container. Such a typical type of stent can include a well-known filter cartridge in which the sorbent particles 100 are held within a crucible housing made of, for example, one or more injection molded outer casing parts. In such a filter cartridge, a single air inlet and/or air outlet may be provided; or a plurality of through holes may be provided in the filter housing to collectively provide an air inlet or an air outlet. Such vias may be sized to prevent sorbent particles from passing therethrough; and/or in some embodiments, a gas permeable protective layer (eg, a mesh or mesh) may be provided to ensure sorbent particle retention Inside the 匣 housing. In some embodiments, the filter holder may be gas impermeable (eg, may not contain a through hole) in the vicinity of the stent (eg, supporting and retaining) the sorbent particles, as in the form of the design of FIG. . In other embodiments, the filter holder may be gas permeable (e.g., may include one or more through holes) in the vicinity of the sorbent particles, as in the design of Figure 2. In some embodiments, a filter holder in the form of a container (eg, a filter cartridge) can include, for example, one or more injection molded housing parts that are assembled together and in addition to (the one or more The air inlet and the (one or more) air outlets may be airtight. Such outer casing parts may conveniently be made, for example, from thermoplastic or thermoset polymers or copolymers selected from, for example, polyamines, polystyrenes, ABS polymers, polyolefins, and the like. Such containers may also include ancillary components such as, for example, one or more resilient pads, latches, splash guards, connectors (eg, as needed to connect the fistula to, for example, a personal respiratory protection device), and the like.

It should be emphasized that the filter holder 10 in the form of a container (as in, for example, Figure 2) does not necessarily have to take the form of a rigid jaw made, for example, of an injection molded part. Rather, in some embodiments, such a container may take, for example, two air transport "walls" Form, at least one of which is made of a relatively flexible material (eg, a porous substrate such as a fibrous web, a perforated or microperforated flexible polymer film, etc.) wherein the sorbent particles are sandwiched between the two Between the walls. Such a container (which may still generally be referred to as a filter "cartridge") may take the form of, for example, a bag or a pouch.

Still further, the term filter holder also broadly encompasses any porous gas permeable material on which the sorbent particles 100 are disposed or within the porous gas permeable material. (Porous gas permeable material means a material comprising internal porosity that is interconnected to allow gas flow through the material, as distinguished from, for example, a closed cell foam.) Such materials may be, for example, of any suitable type. a porous foam material; or such material may be a microporous film; for example, a phase change film, a track etch film (for example, having the type exemplified by various products available from various Whatman under the trade name NUCLEPORE); or, Stretch-expandable films (e.g., of the type exemplified by various products available from WL Gore and Associates under the trade designation GORE-TEX and available under the trade designation CELGARD from the Celgard corporation.) It should be understood that this general type of filter holder 10 It is not limited to use, for example, in pairs, in order to define an interval therebetween as described above. In some embodiments, such a filter holder 10 can take the form of a sheet of material that exhibits a major plane and exhibits a thickness of less than about 8, 5, 3, or 1 mm, regardless of the particular mode of use, and It is configured to allow airflow therethrough at least in a direction that is at least substantially perpendicular to the major plane of the sheet of material.

It will be understood from the above discussion that a filter holder as disclosed herein broadly encompasses any material or arrangement in any form or geometry (and whether by a single entity such as a non-porous substrate, a gas permeable net, or a porous foam). Composition, or by common An assembled assembly of filter elements is formed that can present sorbent particles to the air, such as a moving air stream. In some embodiments, the filter holder can be configured such that moving air can flow, for example, at least substantially parallel to the main surface of the stent with the sorbent particles (eg, as in the arrangement of Figure 1). In some embodiments, the moving air can flow at least substantially perpendicular to the major surface of the stent (eg, as in the arrangement of Figure 2). In some embodiments, moving air may flow in a direction intermediate between the two extremes. In some embodiments, the gas flow in both directions and/or in the middle between the two extremes may occur, for example, in different portions of the air filter.

In a typical type of embodiment illustrated in the exemplary manner of FIG. 3, the air filter 1 can include a filter holder 10 in the form of a "honeycomb" 15. Those of ordinary skill will recognize the hive as a flow-through support structure that includes a plurality of macroscopic through-holes that allow airflow therethrough, the voids being separated from each other by a partition (wall) of the honeycomb structure. (Although the term honeycomb is used herein for convenience, it will be understood by those of ordinary skill that the structure can have any geometric shape (e.g., having a square, triangle, circle, etc.) and can exhibit a slightly irregular appearance. Rather than being strictly limited to the regular hexagonal geometry shown in the exemplary design of FIG. 3). Often, such honeycombs may comprise through-holes having a relatively large diameter or equivalent diameter (e.g., 10 to 15 mm) in contrast to the stacked microstructured substrates described above, which may often comprise only a few millimeters, for example. Or smaller diameter or equivalent diameter flow channels. The walls of the honeycomb can be made of any suitable material, such as molded or extruded plastic, cardboard or cardboard, metal, and the like.

In some embodiments, the sorbent particles can be attached to an inner wall that defines the pores of the honeycomb. However, in some embodiments, it may be convenient to utilize the sorbent particles in part or at least substantially fill the pores of the honeycomb as in the case of filling behavior, depending on, for example, the average of the sorbent particles. Size, size distribution, and shape). In this case, the honeycomb may have upstream and downstream gas permeable substrates (eg, suitable meshes or screens) that allow gas to enter and exit the honeycomb's through-holes and also retain sorbent particles in the hive. Inside the hole. (The direction of the gas flow in the exemplary honeycomb of Figure 3 is as shown by the circle/dot arrows.) In some embodiments, the sorbent particles can be loosely packed within the pores, for example to enable the particles to move slightly or shift. In other embodiments, the sorbent particles can be combined with each other (eg, by using an adhesive, a heat activated adhesive, etc., in an amount sufficient to bind the particles to each other at the point of contact, but the amount will not unacceptably clog Particles affect their ability to capture gaseous species, for example, to minimize migration or settling of particles within the pores. In other words, in some embodiments (not necessarily limited to use in a honeycomb), the sorbent particles 100 may be provided by a single piece of gas permeable mass (in any desired size and by agglomeration of the combined particles). The form of the shape is provided instead of being provided as individual particles. Manufacturing such a monolithic structure (which again can have any suitable size and shape for incorporation into any desired air filter, for example for mating into a container such as, for example, a crucible or can, or for use An exemplary method for forming a layer such as a respirator is discussed, for example, in U.S. Patent 5,033,465, to Braun. A method of bonding sorbent particles together to produce a structure that is particularly at least semi-flexible (and thus may be particularly suitable for use in, for example, a flexible respiratory mask) is discussed, for example, in U.S. Patent No. 6,391,429 to Senkus.

It will be understood by those of ordinary skill that there may not necessarily be a strong dividing line between some of the above-mentioned embodiments (e.g., provided between the sorbent particles within the hollow tube, provided by the stacked micro Within the channels defined by the structured substrate, provided within the pores of the honeycomb). All such designs and arrangements, as well as combinations thereof, are encompassed within the general concept of an air filter comprising one or more filter holders as disclosed herein. It is particularly noteworthy that in some embodiments, the air filter 1 as disclosed herein may comprise a partial fill or at least substantially fill to any suitable container (with any geometric form and by any material (whether rigid or at least) The sorbent particles in the interior of the semi-flexible) are formed to form, for example, a packed bed. In some embodiments, such a container may take the form of a hollow tube, such as a tube similar to a gas detection tube, often referred to as a Dräger tube.

In some embodiments, the filter holder 10 can comprise a thin sheet of material having a plurality of through holes 22 that allow airflow therethrough, as shown in the illustrative general representation in FIG. In various embodiments, the filter holder 10 can take the form of any suitable netting, mesh, screen, sliver, woven or knitted material, melt spun material, microperforated film, and the like. For ease of describing any such material, the term netting will be used herein to include relatively few (five or fewer; often a single layer as in Figure 4) filament layer (or usually in wear). a layer of solid material between the openings). Often, the diameter of such filaments (or a sheet-like filter scaffold material such as a solid portion of a microperforated membrane) or its equivalent is relatively large (e.g., 0.1, 0.2, or 0.5 mm, or greater). Such a netting may comprise any suitable material such as an organic polymer, an inorganic material (eg, glass or ceramic), or a metal or metal alloy.

In such embodiments, the gas flow may occur primarily through the through holes 22 between the solid portions 21 (eg, filaments) of the netting such that the gas flow is oriented at least substantially perpendicular to the scaffold; however, if desired, the gas flow may be at least It occurs roughly parallel to the netting. In the case of a substantially vertical flow of air through the netting, it may be convenient for the sorbent particles to be located on the upstream side 23 of the netting (as in Figure 4). However, if desired, the sorbent particles can be located on the downstream side 24 of the netting. In a particular embodiment, the sorbent particles can be located on either side of the netting. In some embodiments, a netting comprising sorbent particles (or generally any substrate that is sufficiently permeable) can be used in an "open-face" form, as in the illustrative embodiments of Figures 1 and 4. in. In other embodiments, a sufficiently permeable secondary retention layer (eg, a second netting layer, or a fibrous web layer, a microporous film, or the like) can be placed on top of the sorbent particles to help retain the sorbent The particles are in place. (In other words, the sorbent particles can be sandwiched between the netting and the secondary retaining layer.)

In many embodiments, the sorbent particles 100 can be, for example, by means of an adhesive provided on at least one major surface on one side of the netting (eg, a pressure sensitive adhesive, a hot melt adhesive, an epoxy adhesive, And the like) 28 binds (eg, bonds) to the solid material of the netting (eg, filaments). The sorbent particles can each be bonded to, for example, a single filament, or can be bonded to a plurality of filaments. If desired, the average diameter of the filaments and the average size of the through-holes between the filaments can be selected in view of the average size of the sorbent particles. In various embodiments, such netting can exhibit an average filament diameter in the range of, for example, 0.2 mm to about 2.0 mm. In various embodiments, the opening of the netting can range, for example, from a minimum dimension of about 0.5 mm to a longest dimension of about 5 mm, and can be selected in view of the particle size of the sorbent. By way of a specific example, a netting having an opening in the range of about 1 to 2 mm is well suited and exhibitable A particle size sorbent in the range of 8 x 20 mesh is used together. Exemplary nettings that may be suitable for use as disclosed herein include various products commercially available from Delstar Technologies; for example, under the trade names KX215P, R0412-10PR, RB0404-10P, N02014-90PP, RB0404-28P, N03011-90PP And products purchased by TK16-SBSH.

In a particular embodiment, a suitable pressure sensitive adhesive 28 can be provided on the major surface of the netting (in other words, the pressure sensitive adhesive can be provided in a filament that provides the major surface of the net together) On the surface). This can be done, for example, by applying a pressure sensitive adhesive precursor to the network and then converting the precursor to a pressure sensitive adhesive. The precursor may be, for example, a solution of one or more organic solvents, an emulsion, a hot melt composition, and the like. Such precursors can be converted, for example, by drying to remove solvent and/or water, by cooling to solidify the hot melt composition, and the like. Deposition and conversion should be carried out in a manner that avoids unacceptable filling or blocking of the through-holes of the netting (unless the gas stream does not pass through the netting in the ordinary use of the filter).

It should be understood that in some embodiments, the particles disposed on the knot network may be attached to the netting primarily due to, for example, bonding (rather than via mechanical entanglement, for example). In some embodiments, the sorbent particles can be present on the filter holder at least substantially in the form of a single layer. In other embodiments, the sorbent particles may be present in multiple layers (eg, by adhering the first sorbent particle layer to the major surface of the netting, at the first sorbent particle) An additional adhesive is applied to the top of the layer to deposit more sorbent particles, and the process will be repeated to create a collection of sorbent particles of any desired depth.

In some embodiments, the filter holder 10 can comprise a sheet of material comprising a plurality of fibers that are often entangled with one another and often present in many In the "layer" (for example, more than five layers), as shown in the exemplary embodiment in FIG. For ease of describing any such material, a term web will be used herein. It will of course be understood that due to the random nature of many such webs, the fibers may not necessarily (and often will not) be present in discrete layers (e.g., layers that may be peeled from each other); however, if, for example, from the first of such networks This will be apparent when the major surface 43 traverses its thickness (depth) to a cross section of five or more separate fibers or fibers in its second major surface 44 (as in Figure 5). Any material exhibiting such a fiber arrangement falls under the definition of a web as used herein.

Often, the diameter of such fibers or their equivalents may be relatively small (eg, less than 100, 80, 60, 40, 20, 10, 5, or 2 [mu]m). Mixtures of fibers having various diameters can of course be used. Such webs may be of any suitable type, such as non-woven webs in which the fibers are relatively randomly arranged (e.g., such as may occur in the case of, for example, carded webs and in certain types of fiber deposition methods). Part of the amount of fiber is aligned). Alternatively, such webs may comprise a knitted or woven web in which the fibers are provided in a sufficient number of layers. In general, air will flow through the mesh by passing through the interstitial space between the plurality of fibers of the mesh; often such airflow is oriented as at least substantially perpendicular to the major plane of the web in Figure 5. However, if desired, the gas stream can occur at least substantially parallel to the major plane of the web. The fibers of such webs can be bonded to each other in any suitable manner (so that the web has sufficient mechanical integrity for processing and handling). Such binding methods can be selected, for example, from hydroentanglement, needle sticking, calendering, and the like. In some embodiments, the fibers can be self-engaged with one another, which means that the fibers are obtained at elevated temperatures, such as in an oven, or by so-called through-air bonding agents, such as at point bonding or pressure. No solid contact pressure is applied to the extension. In a particular embodiment, the fibers may be bonded using a conventional type of auto-bonding process as described in U.S. Patent No. 7,947, 142 to Fox, in which a stream of heated air passes through a collection of fibers followed by intense quenching. Alternatively, one or more binders (whether fibers, solid particles, water-born emulsions, etc.) may be added and then activated (eg, by heating) to bond the fibers together to form the final web. As indicated below, any such bonding operation (whether primarily mechanically by entanglement of fibers, or by fusion bonding using fibers and/or by the use of added binders) may additionally be used to The particles of the agent are bonded to the net or to the web.

In some embodiments, the sorbent particles may be deposited predominantly or exclusively on the major surface of the web (eg, the primary upstream surface) in a manner similar to the arrangement of the particles on the knot network of FIG. In some embodiments, at least some of the sorbent particles can at least partially penetrate into the interior of the web. (This is in contrast to the case with a netting provided by, for example, a single layer of filaments as in Figure 4, in which case the scaffold has little or no "interior" that the sorbent particles can penetrate. In some such embodiments, the sorbent particles may be primarily found in the region of the web adjacent to or in which the major surface of the sorbent particles are deposited. However, in many embodiments, it may be desirable to provide the sorbent particles 100 widely distributed throughout the thickness of the web (as shown in the illustrative embodiment of Figure 5) rather than by particles. For example, it is deposited onto a surface such that it remains on the surface or only penetrates into the interior of the web for a short distance. Suitable methods of forming a web of sorbent particles that are widely (e.g., randomly) distributed throughout the interior of the web are discussed later herein.

In a particular embodiment, the web filter holder can be a non-woven web. By definition, nonwoven webs do not encompass, for example, woven or knitted webs or microperforated films. Such a network can borrow Made by any suitable method and can be of any suitable type. For example, such nonwoven webs may be: carded webs; wet-laid webs (eg, made by a papermaking process); dry-laid webs, such as by conventional airlaid processes such as well known Rando-Webber process, or by a gravity-laid process as described in U.S. Patent No. 8,834,759 to Lalouch; or a melt-spun mesh (e.g., spunbond, spunlace, etc.). (It should be understood that depending on, for example, the depth of the dropped fibers, certain, for example, spunbonded webs or spunlaced webs may be considered as netting, rather than fibrous webs.) In particular embodiments, the nonwoven web may be a meltblown web, The methods and resulting webs will be well known to those of ordinary skill. Any combination of layers of these various materials (including combinations with layers that are not non-woven mesh) can be used. The fibers can be made of any suitable material, such as thermoplastic organic fibers (such as, for example, polyolefin fibers, cellulose fibers, polyester fibers, nylon fibers, etc.), inorganic fibers (such as, for example, glass fibers or ceramic fibers), metal fibers, and the like. .

The sorbent particles can be provided on and/or within a porous material (e.g., a fibrous web such as a nonwoven web) by any suitable means to form a filter holder for the air filter disclosed herein. In some embodiments, the sorbent particles can be deposited on or in an off-the-shelf web. For example, in some embodiments, the nonwoven web may comprise one or more bonding components, such as a bondable fiber and/or a non-fibrous binder (the non-fibrous binder may take the form of, for example, particles, emulsions, or latex, etc.) . The web can be heated to a temperature to soften and activate the binding component(s), and the sorbent particles can then be deposited onto the major surface of the nonwoven web to be bonded. It should be understood that many such processes may preferentially result in the presence of sorbent particles on or near the major surface of the nonwoven web on which the sorbent particles are deposited. If needed, This method is repeated multiple times in which successive layers are bonded together to form a multilayer product in which sorbent particles are included.

In other embodiments, the sorbent particles can be introduced into the nonwoven web during the manufacturing process of the web. For example, if a nonwoven web is produced by meltblowing, it may be convenient to introduce the sorbent particles into the flowing initial fiber stream (in the beginning of the term fiber means that the solids may or may not have begun to solidify into fibers or complete solidification. Melt flow of fibers). A general method of performing such an operation is disclosed in U.S. Patent Application Publication No. 20120272829, the disclosure of which is incorporated herein by reference. The initial fibers can be deposited under conditions in which the initial fibers are at least slightly viscous (adhesive) (e.g., on a secondary collection surface or as a secondary web retained as part of the filter holder). Such an arrangement may provide that at least some of the fibers of the meltblown nonwoven web are bonded (eg, melt bonded) to the sorbent particles. In this way, a meltblown web containing sorbent particles therein can be fabricated in a single operation.

Of course, other methods can be used to introduce the sorbent particles into the mixture of fibers prior to collecting the fibers as a web. For example, the sorbent particles can be mixed with fibers that are fed to a web forming process (e.g., the gravity-laid web forming process mentioned above) to form a fibrous block containing the collected sorbent particles therein. Such methods can include adding a binder (whether in the form of fibers or a non-fibrous binder, such as particles, emulsions, etc.) to the input material such that the collected fiber pieces can be heated to bond the fibers together to form The mesh and/or the sorbent particles are incorporated into the mesh. Regardless of which method is used, the primary mechanism by which the sorbent particles are incorporated into or onto the web can be the same or different than the bonding mechanism used to bond the fibers together to form a web.

With particular regard to meltblown webs, a variety of fibers can be used to form polymeric materials to form such fibers. At least some of the fibers can be made from materials that exhibit sufficient bonding (adhesion) properties under conditions used in the manufacture of nonwoven webs (e.g., meltblown conditions). Examples include thermoplastic plastics such as polyurethane elastomers, polybutylene elastomers, polyester elastomers, polyether block copolymerized polyamide elastomers, polyolefin-based elastomers (for example, available under the trade name VERSIFY from Dow And elastomeric styrenic block copolymers (for example, available under the trade designation KRATON from Kraton Polymers, Houston, TX). Multicomponent fibers (eg, core-sheath fibers, splittable or side-by-side bicomponent fibers, and so-called "islands in the sea" fibers) may also be used, wherein at least one exposed surface of the fibers (eg, The sheath portion of the core-sheath fiber) exhibits sufficient adhesive properties.

In some embodiments, the fibers that can be bonded to the sorbent particles 100 can be the only fibers present in the meltblown web. In other embodiments, other fibers may be present (eg, such that they do not participate in binding sorbent particles to any significant extent), for example, as long as sufficient binder fibers are present. In various embodiments, the bondable fibers can comprise at least about 2 weight percent, at least about 4 weight percent, and at least about 6 weight percent of the meltblown nonwoven web. In further embodiments, the bondable fibers can comprise no more than about 20 weight percent, no more than about 17 weight percent, and no more than about 15 weight percent of the meltblown nonwoven web. Any non-bondable fibers present in the web can be of any suitable type and composition; for example, any of the well-known polyolefin fibers (e.g., polypropylene, polyethylene, and the like) can be used, as can any known polyester fiber. . In at least some embodiments, the nonwoven web is substantially free of any added binder of any kind. That is, in such cases, substantially all of the adhesion of the sorbent particles (to hold them in the meltblown nonwoven web) is It can be performed in combination with fibers. Thus, such embodiments preclude the presence of binders in the form of, for example, particles or powders, liquids such as latexes, emulsions, suspensions, or solutions.

It should be understood that the above discussion relates to a method in which the combination of fibers and sorbent particles is used, at least in part, to retain particles within a nonwoven web. The physical entanglement of the sorbent particles within the fibers can also help retain the sorbent particles within the nonwoven fabric. In some embodiments, a secondary gas permeable layer (eg, a sliver or inner welt) can be applied (eg, bonded) to one or more major surfaces of the nonwoven web to minimize any sorbent particles from non- The opportunity to remove the web. In fact, in some embodiments, it may be convenient to deposit the initial fibers forming the meltblown nonwoven web (along with the sorbent particles incorporated into the initial fiber stream) into a secondary web (eg, slivers) On the major surface of the yarn or inner gusset, the meltblown web is bonded to the secondary web in the manufacture of the meltblown web.

In some embodiments, the air filter 1 can include at least one filter media 40. The filter media is a filter holder 10 that retains the sorbent particles 100 and exposes them to air; in addition, the filter media is a specific type of filter holder that is capable of filtering a significant amount of filtered air from the moving air. Microscopic particles (ie, particles having an average diameter of 100 microns or less). The filter media 40 can comprise any material that provides a gas permeable mesh structure and, in addition, is capable of filtering microscopic particles by itself, and sorbent particles can be incorporated into or onto the gas permeable mesh structure to present the sorbent particles to positive Air flow through the gas permeable mesh structure. Such filter media can be, for example, a nonwoven web, which is a meltblown web and/or a belt grid.

As indicated, the filter media is capable of capturing significant amounts of microscopic particles (100 [mu]m or less in diameter). In a particular embodiment, the filter media may be capable of capturing a significant amount in the range of, for example, 10 [mu]m or less or even in the range of 2.5 [mu]m or less. Fine particles inside. In a particular embodiment, the filter media may be capable of performing HEPA filtration. It will be appreciated that the use of an electret (charged) material as described below can substantially enhance the ability to perform, for example, fine particle filtration or HEPA filtration. In various embodiments, the filter media 40 can exhibit a penetration percentage of less than about 80, 70, 60, 50, 40, 30, 20, 10, or 5 (designated herein as using dioctyl phthalate as The material was challenged and tested using the method described in US Pat. No. 7,947,142 to Fox). All of the processes described herein with respect to filter holders (e.g., fiber bonding, charging, pleating, and the like), parameters, and characterization can be specifically applied to filter media.

In some embodiments, a nonwoven web (eg, a meltblown nonwoven web) that acts as a filter holder (or particularly as a filter media) can include electrostatically charged fibers. The charging of such fibers can be imparted to the nonwoven web by any suitable means, such as by the use of water as taught in U.S. Patent No. 5, 546, 057, issued to the name of U.S. Pat. The charge is coming. Non-woven electret webs can also be produced by corona charging as described in U.S. Patent No. 4,588, 537 to Klaase, or by mechanically imparting a charge to the fibers as described in U.S. Patent No. 4,798,850, the entire disclosure of which is incorporated herein. Any combination of such methods can be used. The fibers can be charged prior to forming the nonwoven web or after forming the nonwoven web. (In any case, for pleating, any such charging can be conveniently performed before the air filter media pleats.) The air filter includes a particle filter layer that is a different layer than the filter holder 10. In the case (as described below), such a particle filtration layer can be charged, for example, by any of the above methods, if desired.

If the filter holder (either stand-alone or part of a multi-layer assembly) is pleated, the pleat formation and pleat spacing can be performed using any suitable technique. The disclosures are disclosed in U.S. Patent No. 4,798,575 to Siversson, U.S. Patent No. 4,976,677 to Siversson, and U.S. Patent No. 5,389,175 to Wenz. Pleated treatment procedures that can be used are also described in, for example, U.S. Patent No. 7,235,115 to Duffy. (However, it should be understood that in at least some embodiments, the use of score-pleating may be avoided because the scoring process can be used to comminute at least some of the sorbent particles.) In various embodiments, pleating The air filter holder can include from about 0.5 to about 5 pleats per 2.5 cm. More specifically, the pleat spacing can be, for example, about 6, 8, 10, or 12 mm to about 50, 40, 30, 20, or 15 mm. In various embodiments, the pleat height can be, for example, from about 15, 20, 25, or 30 mm to about 100, 80, 60, or 40 mm.

The air filter 1 may comprise a filter holder 10 consisting of a single layer (by definition, which supports at least some of the polymeric sorbent particles 100); or a plurality of filter holders 10 layers (eg, each layer comprising at least some polymerizability) The sorbent particles 100) may be present in the air filter 1. In particular, if the filter holder(s) 10 are not themselves an air filter medium as defined herein, the air filter 1 may include one or more (in addition to the at least one filter holder layer 10) The particle filter layer (for example, capable of filtering microscopic particles, fine particles, and/or HEPA filtration) does not include the polymerizable sorbent particles 100. Such a particle filter layer can be electrostatically charged (if desired) and can exhibit a percent penetration of less than about 80, 70, 60, 50, 40, 30, 20, 10, or 5 in various embodiments. (Using particles broadly encompasses, for example, aerosols, dust, fumes, smoke, smoke, mildew, bacteria, spores, pollen, etc.) In particular embodiments, such particulate filter layers can be highly fluffy spunbonded nonwovens. a net, which is described, for example, in U.S. Patent No. 8,240,484, to Fox. Type, and comprising less than 8% to about 4% solidity, and comprising melt spun fibers that are substantially free of crimped fibers, gap formed fibers, and bicomponent fibers.

Regardless of the presence or absence of any particle filter layer, the air filter 1 may comprise (in addition to at least one filter support layer 10 and any optional particle filter layer) one or more, for example, as a cover layer, a coarse pre-filter, a carrier layer Secondary layers of skin contact layers (eg, slivers, netting, coverings, etc.) to provide mechanical support or stiffness and the like. That is, typically, and regardless of the particular type, configuration, or configuration of the filter support layer 10, such a filter support layer can be provided as a layer of a plurality of layers of gas permeable components (stacks) that can collectively provide an air filter 1 . As described herein, any such multi-layer stack can of course be pleated, framed, and the like.

The sorbent particles disclosed herein (whether, for example, dispersed within a nonwoven web, disposed on a surface of a substrate, filled into a socket (eg, forming a filled bed), can be sorbed with any secondary The agent particles are used in combination to be configured to capture any desired components (eg, hazardous gases/vapors) present in the air. In some embodiments, such secondary sorbent particles can be present in separate layers, such as upstream or downstream of the polymeric sorbent particles 100. In other embodiments, the sorbent particles 100 and any desired secondary sorbent particles(s) may be mixed together. The secondary sorbent particles (whether for separate layers or as a miscible mixture with polymeric sorbent particles 100) may be selected, for example, from activated carbon, alumina and other metal oxides, clay, cholera, ions Exchange resins, molecular sieves, and zeolites, cerium oxide, sodium bicarbonate, and the like, including combinations of any of these materials. In a particular embodiment, the secondary sorbent particles (e.g., activated carbon) can be impregnated with sorbent particles, which are suitably impregnated with, for example, any desired metal salt. Or a compound. Various particles, including impregnated particles, which may be suitable for use as secondary sorbent particles are described in detail in U.S. Patent Application Publication No. 2015/0306, the entire disclosure of which is hereby incorporated by reference. Any combination of any of these particles can be used.

In some embodiments, an air filter 1 comprising sorbent particles 100 as disclosed herein can be used in combination with a secondary air filter that is provided separately from the air filter 1. In some embodiments, the air filter 1 and the secondary air filter may be separately assembled into different regions of the air treatment device. (For example, the air filter 1 and the secondary air filter may each be a frame type air filter, and may be separately inserted into, for example, an indoor air cleaner.) Alternatively, the air filter 1 and the secondary air filter may be They are assembled together (for example, attached to each other) before being assembled, for example, to an air handling device. The air filter 1 can be placed upstream or downstream of, for example, a secondary air filter (if the air filter 1 is upstream, it can be used as a pre-filter such as a secondary filter). In some exemplary embodiments, the secondary air filter may be configured to capture, for example, fine particles, and may exhibit, for example, a penetration of less than about 80, 70, 50, 60, 40, 30, 20, 10, or 5 percentage.

The filter holder 10 comprising the sorbent particles 100 disclosed herein can be used with any type of air filter 1 that is configured for any suitable end use. By way of a specific example, the filter holder 10 can be used, for example, in an air filter that is a personal respiratory protection device or a portion thereof. It has been pointed out that the filter holder 10 can take the form of a filter cartridge that can be fluidly coupled to the mask body to provide a personal respiratory protection device (eg, a filter tethered, and the mask main system is shaped to fit use The face of the person and the piece being held, and the replacement filter 附 is attached to the mask body at an appropriate time). In other embodiments, the filter holder 10 can be incorporated into a "filtering face-piece" respirator mask 60. In such a typical type of product, the mask body itself provides a filtering function. That is, unlike using a mask body with a respirator to which a filter cartridge or the like can be attached, the filter mask respirator is designed such that the filter layer(s) are present throughout most or substantially all of the entire mask body. This eliminates the need to assemble or replace the filter cartridge. (i.e., in a filtered facepiece respirator, the mask body itself performs a filtering function rather than relying on one or more ports attached thereto.) The filtering facepiece respirator 60 often appears in one of two configurations: mode Made (for example, shaped into a generally cup shape to fit the user's face), as shown in the illustrative representation in Figure 6; and flat-fold, which may be provided in flat or near flat conditions, and then It can be deployed and stretched to fit the user's face, as shown by the illustrative representation in FIG.

Such a respirator mask (whether, for example, a flat-fold respirator or a molded respirator) 60 can comprise any desired auxiliary layer (eg, one or more cover layers, a stiff layer, a pre-filter layer, and the like) And components (such as one or more exhaust valves, attachment straps or strings, nasal masks, etc.). If used in a flat-fold respirator mask, the filter holder 10 can often take the form of a relatively flexible layer (e.g., one or more preferential fold lines 63 are provided to make the material more foldable). If the filter holder 10 is used to mold a respirator mask (which is not designed to be foldable), the filter holder 10 can be, for example, a slightly semi-rigid material (however, it should be noted that due to the many molded cup respirators) Most of the stiffness in the mask may be provided by a stiff layer separate from the filter layer(s), so the filter holder 10 may not necessarily be rigid, or even semi-rigid, for use in such products).

It should be understood that the above-mentioned uses mainly fall within the category of so-called "negative-pressure" respirators; that is, the motive power for moving the air is the user's breathing rather than the separately provided electric fan product. Such negative pressure respirators are often configured, for example, as full respirators, half-face respirators, and covers (eg, escape covers, hoods, and the like). All such products are covered by the term negative pressure respirator as used herein, and the filter holder 10 can be used with any such product.

In other embodiments, the filter holder 10 can be used to move a regenerator of an air powered electric fan or blower. Such products may include, for example, PAPR (Powered Air Purifying Respirators). In such products, the filter holder 10 (and, typically, the air filter 1) can be positioned near the face or head of the user; or it can be positioned remotely (eg, in the socket of the belt worn outer casing).

In some embodiments as shown in the exemplary embodiment of FIG. 8, the filter holder 10 (eg, whether pleated or not, whether or not including any other layers, such as a particle filter layer, etc.) may be Into the air filter 1, the air filter 1 includes a perimeter frame 70 (eg, a stiffening or support frame) that can be disposed, for example, around a peripheral edge region of the filter holder. Suitable materials for the frame include chipboard, or cardboard, synthetic plastic materials, and metals. A suitable frame construction may be selected from the "pinch" frame construction shown in Figures 1 to 4 of U.S. Patent No. 6,126,707 to Pitzen, and the "box" shown in Figures 5 and 6 of the '707 patent. Frame construction, the split frame construction shown in Figures 7 to 11 of the '707 patent, any of the frame constructions disclosed in U.S. Patent No. 7,503,953 to Sundet, and any of the disclosures of U.S. Patent No. 7,235,115 to Duffy. Frame construction. Any such frame can be attached to the filter holder by any suitable method (eg, hot melt bonding, room temperature glue, etc.).

The air filter 1 including the filter holder 10 (whether or not framed) can be advantageously used in any suitable powered air handling system (eg, in an HVAC system) (eg, often used in residential, office buildings, Moving air is filtered in forced air heating, cooling, and/or heating/cooling systems in retail locations and the like. Such filters can also be used in indoor air purifiers, electric vehicles (such as in cabin air filtration, such as automobiles), clean rooms, studios, and the like. In some embodiments, as noted above, the air filter 1 (eg, as part of the filter cartridge) can be inserted into the air passage of the powered air purifying respirator. While air filter 1 may not necessarily be a frame air filter in any or all such applications, in many such applications it may be advantageous for air filter 1 to be a frame air filter.

The above discussion relates to the provision of polymeric sorbent particles 100 on a suitable filter holder 10 to provide an air filter 1, and to position the air filter such that the supported sorbent particles are exposed to air (used in a wide range of air systems) It also covers any gas or mixture of gases, such as nitrogen, dehumidified nitrogen or air, oxygen-enriched air, air including anesthetic gases or gas mixtures, and the like. In many embodiments, the air exposed by the sorbent particles is in the form of a moving air stream. In some cases (which may be referred to as "active" filtering), such moving air may be propelled by an electric blower, fan, or the like. In other cases (which may be referred to as "passive" filtering), such moving air may be propelled, for example, by human breathing rather than by any motor. The term "passive" filtering also encompasses the exposure of the air filter 1 to, for example, an ambient atmosphere, The case of eddy currents, and the like. Such airflows and eddies may take the form of, for example, wind (such as an outer surface that may impact the filter holder 10 in the form of, for example, a screen window). Alternatively, in an indoor environment, such airflows and eddies may take the form of convection, random airflow, etc. that occur periodically within the interior of the building (due to, for example, door opening and closing, human movement, and the like). Accordingly, it should be understood that the air filter 1 as disclosed herein encompasses devices such as a crucible, bag, pouch, can, or generally any type of container that holds the sorbent particles 100 therein and has at least one The gas permeable walls allow air to enter the container and contact the sorbent particles and then exit the container, whether or not such devices are used with any kind of mechanical blower or for any kind of respirator.

Broadly speaking, the air filter 1 as described herein can be used in any suitable application where it is desirable to remove at least some of the aldehyde molecules from the air. Such uses may involve personal devices designed for use by a single user (eg, personal respiratory protection devices), or collective devices designed for use in, for example, buildings, vehicles, and other locations, whether living, working, or gathering. (eg indoor air purifiers, HVAC systems, etc.). As noted, such uses may involve "active" or "passive" filtering, and may use air filtering configured in any of a variety of geometric formats and including any of a variety of materials. Device 1. It is also noted that in addition to the polymeric sorbent particles 100 described herein, one or more secondary sorbents may be used, whether mixed with the particles 100 and/or provided in separate layers. As further indicated, the air filter 1 can include at least one layer (in addition to the at least one scaffold layer 10 supporting the polymeric sorbent particles 100) that provides fine particle filtration and/or some of its capture of non- aldehydes Gas/vapour. In addition to or as an add-on to this, in addition to the air filter 1, a secondary air The gas filter, for example, performs filtration of fine particles and/or captures some other gas/vapor. Further, a combination of any of the above embodiments of the filter holder can be used. For example, the polymeric sorbent particles 100 can be disposed within the web or onto the surface of the netting, which can be placed, for example, within the outer casing to provide a filter crucible.

The polymerizable sorbent particles 100 are a reaction product of a divinylbenzene/maleic anhydride precursor polymeric material and a nitrogen-containing compound. The nitrogen-containing compound becomes covalently attached to the polymeric material. Polymeric sorbents are typically provided in the form of porous particles in which the pore size is often in the range of mesopores and/or microvoids. Polymeric sorbents can be used to sorb volatile aldehydes at room temperature or under conditions of use. Suitable aldehydes generally have the formula (I) R ₂ -(CO)-H (I) wherein R ₂ is hydrogen, alkyl, vinyl, or aryl. The molecular weight of the aldehyde having the formula (I) is generally not more than 200 g/mole. In some embodiments, the aldehyde is formaldehyde (R ₂ -based hydrogen) or acetaldehyde (R ₂ -based methyl).

As indicated above, the polymeric sorbent is obtained by the reaction of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen containing compound. The precursor polymeric material is synthesized from a polymerizable composition comprising a monomer mixture comprising maleic anhydride, divinylbenzene, and optionally a styrenic monomer. More specifically, the precursor polymeric material is formed from a monomer mixture comprising: 1) 8 to 65 weight percent maleic anhydride, 2) 30 to 85 weight percent divinylbenzene, and 3) 0 to 40 A percentage by weight of a styrenic monomer, wherein the styrene type is a single system styrene, an alkyl substituted styrene, or a combination thereof. The amount is based on the total weight of the monomers in the monomer mixture, which is equal to the polymerizable composition The total weight of the monomers. When a precursor polymeric material is used to form a polymeric sorbent that is particularly effective at absorbing an aldehyde, the monomer mixture often contains 1) 15 to 65 weight percent maleic anhydride, and 2) 30 to 85 weight percent divinyl benzene. And 3) 0 to 40 weight percent of a styrene type monomer, wherein the styrene type single system styrene, the alkyl substituted styrene, or a combination thereof.

The maleic anhydride included in the monomer mixture results in the formation of the maleic anhydride monomer unit of formula (II) in the precursor polymeric material. This formula and the asterisks in other formulae encompassed herein refer to the attachment position of a monomer unit to another monomer unit or terminal group.

The amount of maleic anhydride used to form the precursor polymeric material affects the amount of nitrogen-containing compound that can react with the precursor polymeric material to form a polymeric sorbent. The nitrogen-containing compound will react with the anhydride group to become covalently attached to the polymeric material that is a polymeric sorbent.

In some embodiments, the amount of maleic anhydride included in the monomer mixture is at least 8 weight percent, at least 10 weight percent, at least 12 weight percent, at least 15 weight percent, or at least 20 weight percent. The amount of maleic anhydride can be up to 65 weight percent, up to 60 weight percent, up to 55 weight percent, up to 50 weight percent, up to 45 weight percent, up to 40 weight percent, up to 35 weight percent, up to 30 weight percent, or up to 25 Weight percentage. For example: maleic anhydride can be present in an amount from 8 to 65 weight percent, from 15 to 65 weight percent, from 15 to 60 weight percent Fraction, 15 to 50 weight percent, 15 to 40 weight percent, 20 to 65 weight percent, 20 to 60 weight percent, 20 to 50 weight percent, 20 to 40 weight percent, 30 to 65 weight percent, 30 to 60 weight percent 30 to 50 weight percent, 40 to 65 weight percent, or 40 to 60 weight percent. The amount is based on the total weight of the monomers in the monomer mixture contained in the polymerizable composition used to form the precursor polymeric material.

In other words, the precursor polymeric material comprises monomer units of formula (II) in an amount of from 8 to 65 weight percent, from 15 to 65 weight percent, from 15 to 60 weight percent, from 15 to 50 weight percent, from 15 to 40 weight percent, from 20 to 65 Weight percentage, 20 to 60 weight percent, 20 to 50 weight percent, 20 to 40 weight percent, 30 to 65 weight percent, 30 to 60 weight percent, 30 to 50 weight percent, 40 to 65 weight percent, or 40 to 60 weight Within the percentage range. These amounts are based on the total weight of monomer units in the precursor polymeric material.

The divinylbenzene included in the monomer mixture results in the formation of a divinylbenzene monomer unit of formula (III) in the precursor polymeric material.

The two groups attached to the phenyl ring may be ortho, meta or para-aligned to each other. The monomer units of formula (III) contribute to a high crosslink density and contribute to the formation of a hard polymeric material having microvoids and/or mesopores.

The amount of divinylbenzene used to form the precursor polymeric material can have a strong effect on the BET specific surface area of both the precursor polymeric material and the polymeric sorbent. When the amount of divinylbenzene in the monomer mixture for forming the precursor polymeric material and the amount of the monomer unit of the formula (III) in the polymerizable sorbent are increased, the BET specific surface area tends to increase. If the amount of divinylbenzene is less than 30% by weight, the polymerizable sorbent may not have a sufficiently high BET specific surface area. On the other hand, if the amount of divinylbenzene is more than 85 wt%, the occluded amount of the aldehyde may be degraded because the number of nitrogen-containing groups in the polymerizable sorbent is small. In some embodiments, the amount of divinylbenzene included in the monomer mixture is at least 30 weight percent, at least 35 weight percent, at least 40 weight percent, or at least 45 weight percent. The amount of divinylbenzene can be up to 85 weight percent, up to 80 weight percent, up to 75 weight percent, up to 70 weight percent, up to 65 weight percent, up to 60 weight percent, or up to 50 weight percent. For example, the amount may be 30 to 85 weight percent, 30 to 80 weight percent, 30 to 75 weight percent, 30 to 70 weight percent, 30 to 65 weight percent, 30 to 60 weight percent, 30 to 55 weight percent, 30 to 50 weight percent Weight percentage, 35 to 80 weight percent, 35 to 70 weight percent, 35 to 60 weight percent, 40 to 85 weight percent, 40 to 80 weight percent, 40 to 70 weight percent, or 40 to 60 weight percent. The amount is based on the total weight of the monomers in the monomer mixture contained in the polymerizable composition used to form the precursor polymeric material.

In other words, the monomer unit of formula (III) contained in the precursor polymeric material is 30 to 85 weight percent, 30 to 80 weight percent, 30 to 75 weight percent, 30 to 70 weight percent, 30 to 65 weight percent, 30 to 60 weight percent, 30 to 55 weight percent, 30 to 50 weight percent, 35 to 80 weight percent, 35 to 70 weight percent, 35 to 60 weight percent, 40 to 85 weight percent, 40 to 80 weight percent, 40 to 70 weight Percentage, or range of 40 to 60 weight percent. These amounts are based on the total weight of monomer units in the precursor polymeric material.

Divinylbenzene is difficult to obtain in pure form. For example, commercially available divinylbenzene often has a purity as low as 55 weight percent. It may be quite difficult and/or expensive to obtain divinylbenzene having a purity greater than about 80 weight percent. The impurities accompanying divinylbenzene are typically styrenic monomers such as styrene, alkyl substituted styrenes (e.g., ethyl styrene), or mixtures thereof. Thus, styrenic monomers are often associated with the presence of divinylbenzene and maleic anhydride in the monomer mixture contained in the polymerizable composition used to form the precursor polymeric material. The monomer mixture typically contains from 0 to 40 weight percent of the styrenic monomer based on the total weight of the monomers in the monomer mixture. If the styrene type monomer content is more than 40% by weight, the crosslinking density may be too low, and/or the distance between crosslinking may be too large to provide a desired BET specific surface area (for example, at least 25 m ² /g). A polymeric sorbent. As the crosslink density decreases, polymeric sorbents tend to be less rigid and less porous. Generally, a divinylbenzene having a purity of 55 weight percent is not suitable for use in a monomer mixture used to form a precursor polymeric material because the styrene monomer impurity content is too high. That is, in order to provide a monomer mixture having a minimum amount of divinylbenzene, the purity of divinylbenzene is often at least about 80 weight percent. The use of divinylbenzene having a purity of less than about 80 weight percent may result in an undesirable low BET specific surface area for the formed precursor polymeric material and/or polymeric sorbent.

The styrenic monomer included in the monomer mixture results in the presence of the styrenic monomer unit of formula (IV) in the precursor polymeric material.

The group R ₃ is hydrogen or an alkyl group (for example, an alkyl group having 1 to 10 carbon atoms, 1 to 6 carbon atoms or 1 to 4 carbon atoms).

In some embodiments, the amount of styrenic monomer used to form the precursor polymeric material is at least 1 weight percent, at least 2 weight percent, or at least 5 weight percent. The amount of styrenic monomer can be up to 40 weight percent, up to 30 weight percent, up to 20 weight percent, or up to 10 weight percent. For example, the amount may be from 0 to 40 weight percent, from 1 to 40 weight percent, from 5 to 40 weight percent, from 10 to 40 weight percent, from 0 to 30 weight percent, from 1 to 30 weight percent, from 5 to 30 weight percent, from 10 to 30 Weight percentage, 0 to 20 weight percent, 1 to 20 weight percent, 5 to 20 weight percent, or 10 to 20 weight percent. The amount is based on the total weight of the monomers in the monomer mixture contained in the polymerizable composition used to form the precursor polymeric material.

In other words, the monomer unit of formula (IV) contained in the precursor polymeric material is from 0 to 40 weight percent, from 1 to 40 weight percent, from 5 to 40 weight percent, 10 Up to 40% by weight, 0 to 30% by weight, 1 to 30% by weight, 5 to 30% by weight, 10 to 30% by weight, 0 to 20% by weight, 1 to 20% by weight, 5 to 20% by weight, or 10% Within the range of 20 weight percent. These amounts are based on the total weight of monomer units in the precursor polymeric material.

In summary, the precursor polymeric material is formed from a polymerizable composition comprising a monomer mixture comprising from 8 to 65 weight percent maleic anhydride, from 30 to 85 weight percent divinylbenzene, and from 0 to 40 weight percent Styrene monomer. In some embodiments, the monomer mixture contains 15 to 65 weight percent maleic anhydride, 30 to 85 weight percent divinylbenzene, and 0 to 40 weight percent (or 5 to 40 weight percent) styrene type body. Some embodiments contain 25 to 65 weight percent maleic anhydride, 30 to 75 weight percent divinylbenzene, and 1 to 20 weight percent (or 5 to 20 weight percent) styrene monomer. Some embodiments contain 25 to 60 weight percent maleic anhydride, 30 to 75 weight percent divinylbenzene, and 1 to 30 weight percent (or 5 to 30 weight percent or 10 to 30 weight percent) styrene type body. In still other embodiments, the monomer mixture contains 30 to 65 weight percent maleic anhydride, 30 to 70 weight percent divinylbenzene, and 1 to 20 weight percent (or 5 to 20 weight percent or 10 to 20 weight percent) Percentage of styrene monomer. In still other embodiments, the monomer mixture contains 30 to 60 weight percent maleic anhydride, 30 to 65 weight percent divinylbenzene, and 1 to 20 weight percent (or 5 to 20 weight percent or 10 to 20 weight percent) Percentage of styrene monomer. In a further embodiment, the monomer mixture contains 40 to 60 weight percent maleic anhydride, 30 to 55 weight percent divinylbenzene, and 1 to 20 weight percent (or 5 to 20 weight percent, or 10 to 20 weight percent of the styrene type monomer. In still further embodiments, the monomer mixture contains 20 to 40 weight percent maleic anhydride, 50 to 70 weight percent divinylbenzene, and 1 to 20 weight percent (or 5 to 20 weight percent or 10 to 20 weight percent) Percentage of styrene monomer. The weight percent value is based on the total weight of the monomers in the monomer mixture used to form the precursor polymeric material.

The monomer mixture included in the polymerizable composition used to form the precursor polymeric material typically contains at least 95 weight percent of monomers selected from the group consisting of maleic anhydride, divinylbenzene, and styrenic monomers. For example, at least 97 weight percent, at least 98 weight percent, at least 99 weight percent, at least 99.5 weight percent, at least 99.9 weight percent, or 100 weight percent of the single system in the monomer mixture is selected from the group consisting of maleic anhydride, divinylbenzene, With styrene type monomers. In some embodiments using high purity divinylbenzene, the monomer mixture contains only divinylbenzene and maleic anhydride. That is, the total amount of divinylbenzene and maleic anhydride is 100% by weight.

In addition to the monomer mixture, the polymerizable composition used to form the precursor polymeric material also includes an organic solvent. The polymerizable composition is in a single phase prior to polymerization. In other words, the polymerizable composition is not a suspension prior to polymerization. The organic solvent selected should dissolve the monomers included in the monomer mixture and dissolve the precursor polymeric material at the beginning of formation. Organic solvents typically include ketones, esters, acetonitrile, or mixtures thereof.

The organic solvent can act as a porogen during the formation of the precursor polymeric material. The organic solvent selected can strongly influence the BET specific surface area and pore size formed in the precursor polymeric material. The use of organic solvents that are miscible with both the monomer and the polymer formed tends to form microvoids and mesopores in the precursor polymeric material. Monomer and The good solvent tendency of the formed polymer tends to result in a large proportion of the porosity of the final polymerizable sorbent in the form of micropores and mesopores.

Particularly suitable organic solvents include ketones, esters, acetonitrile, and mixtures thereof. Other organic solvents may accompany such a kind of one or more added solvents, but with the proviso that at least equal to 100m ² / g BET specific surface area of the precursor of polymeric material produced. Examples of suitable ketones include, but are not limited to, alkyl ketones such as methyl ethyl ketone and methyl isobutyl ketone. Examples of suitable esters include, but are not limited to, acetates such as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, and tertiary butyl acetate.

Any desired amount of organic solvent can be used. The percentage of solids of the polymerizable composition is often in the range of from 1 to 75 weight percent (i.e., the polymer composition contains from 25 to 99 weight percent organic solvent). If the percentage of solids is too low, the polymerization time may become undesirably long. The percentage of solids is often at least 1 weight percent, at least 2 weight percent, at least 5 weight percent, at least 10 weight percent, or at least 15 weight percent. However, if the weight percentage of the solid is too high, the monomer cannot form a single phase with the organic solvent. In addition, increasing the percent solids tends to result in the formation of a polymeric material prior to the lower BET specific surface area. The percentage of solids can be up to 75 weight percent, up to 70 weight percent, up to 60 weight percent, up to 50 weight percent, up to 40 weight percent, up to 30 weight percent, or up to 25 weight percent. For example, the percentage of solids can range from 5 to 75 weight percent, 5 to 70 weight percent, 5 to 60 weight percent, 5 to 50 weight percent, 5 to 40 weight percent, 5 to 30 weight percent, or 5 to 25 weight percent. Inside.

In addition to the monomer mixture and the organic solvent, the polymerizable composition used to form the precursor polymeric material typically includes an initiator for the free radical polymerization. Any suitable free radical initiator can be used. Suitable free radical initiators are generally selected to be miscible with the monomers included in the polymerizable composition. In some embodiments, the free radical initiator is a thermal initiator that can be activated at temperatures above room temperature. In other embodiments, the free radical initiator is a redox initiator. Since the polymerization reaction is a radical reaction, it is desirable to minimize the amount of oxygen in the polymerizable composition.

Both the type and amount of initiator can affect the rate of polymerization. In general, increasing the initial dose tends to lower the BET specific surface area; however, if the starting dose is too low, it may be difficult to convert the conversion of the monomer into a polymeric material to be high. The free radical initiator is typically present in an amount of from 0.05 to 10 weight percent, from 0.05 to 8 weight percent, from 0.05 to 5 weight percent, from 0.1 to 10 weight percent, from 0.1 to 8 weight percent, from 0.1 to 5 weight percent, from 0.5 to 10 weight percent Percent, 0.5 to 8 weight percent, 0.5 to 5 weight percent, 1 to 10 weight percent, 1 to 8 weight percent, or 1 to 5 weight percent. The weight percentages are based on the total weight of the monomers in the polymerizable composition.

Suitable thermal starters include organic peroxides and azo compounds. Examples of azo compounds include, but are not limited to, those available from EI du Pont de Nemours Co. (Wilmington, DE) under the trade name VAZO, such as VAZO 64 (2,2'-azobis(isobutyronitrile)) (often It is called AIBN), and VAZO 52 (2,2'-azobis(2,4-dimethylvaleronitrile)). Other azo compounds are commercially available from Wako Chemicals USA, Inc. (Richmond, VA), such as V-601 (2,2'-azobis(2-methylpropionic acid) dimethyl ester), V-65. (2,2'-azobis(2,4-dimethylvaleronitrile)), and V-59 (2,2'-azobis(2-methylbutyl) Nitrile)). Organic peroxides include, but are not limited to, bis(1-oxoaryl) peroxides (such as benzamidine peroxide (BPO)), bis(1-oxoalkyl) peroxides (such as lauric acid peroxide). And a mixture with a dialkyl peroxide such as dicumyl peroxide or di-tertiary butyl peroxide. The temperature required to activate the hot starter is often in the range of 25 ° C to 160 ° C, in the range of 30 ° C to 150 ° C, in the range of 40 ° C to 150 ° C, in the range of 50 ° C to 150 ° C, It is in the range of 50 ° C to 120 ° C, or in the range of 50 ° C to 110 ° C.

Suitable redox initiators include aryl sulfinates, triarylsulfonium salts, or N , N -dialkylanilines in combination with metals, peroxides, or persulfates in an oxidized state (eg, N , N -dimethylaniline). Specific aryl sulfinates include tetraalkylammonium arylsulfinates such as tetrabutylammonium 4-ethoxycarbonylbenzenesulfinate, tetrabutylammonium 4-trifluoromethylbenzenesulfinate, and 3 -Tributylammonium trifluoromethylbenzenesulfinate. Specific triarylsulfonium salts include those having a triphenylphosphonium cation and having an anion selected from the group consisting of PF ₆ ^- , AsF ₆ ^- , and SbF ₆ ^- . Suitable metal ions include, for example, Group III metal ions, transition metal ions, and lanthanide metal ions. Specific metal ions include, but are not limited to, iron (III), cobalt (III), silver (I), silver (II), copper (II), cerium (III), aluminum (III), molybdenum (VI), and Zinc (II). Suitable peroxides include benzammonium peroxide, lauric acid peroxide, and the like. Suitable persulphates include, for example, ammonium persulfate, tetraalkylammonium persulfate (e.g., tetrabutylammonium persulfate), and the like.

The polymerizable composition is generally free or substantially free of surfactant. The term "substantially free" as used herein with reference to a surfactant means that no surfactant is intentionally added to the polymerizable composition, and any surfactant that may be present is polymerizable. One of the components of the composition is caused by impurities (example For example, in an organic solvent or an impurity in one of the monomers). The polymerizable composition typically contains less than 0.5 weight percent, less than 0.3 weight percent, less than 0.2 weight percent, less than 0.1 weight percent, less than 0.05 weight percent, or less than 0.01 weight percent of the surfactant based on the total weight of the polymerizable composition. The absence of surfactants is advantageous because these materials tend to limit the entry of microvoids and mesopores in the precursor polymeric material, and in some cases fill the micro and mesopores.

When the polymerizable composition is heated in the presence of a radical initiator, polymerization of the monomers in the monomer mixture occurs. The BET specific surface area equal to at least 100 m ² /g of the precursor can be prepared by balancing the amount of each monomer in the monomer mixture and by selecting an organic solvent that can dissolve all of the monomers and the growing polymeric material at an early stage of formation. Polymeric material. The polymeric material precursor BET specific surface area may be based at least 150m ² / g, at least 200m ² / g, or at least 300m ² / g. BET specific surface area may be, for example: up to 1000m ² / g or more, up to 900m ² / g, up to 800m ² / g, up to 750m ² / g, or up to 700m ² / g.

The precursor polymeric material is the reaction product of the polymerizable composition. The precursor polymer material formed from the polymerizable composition contains (a) 8 to 65 weight percent of the first monomer unit of formula (II), (b) 30 to 85 weight percent of the second monomer unit of formula (III), and (c) 0 to 40% by weight of the third monomer unit of the formula (IV), wherein R ₃ is hydrogen or alkyl (for example, having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4) An alkyl group of carbon atoms).

In many embodiments, to be a polymeric sorbent particularly effective for aldehydes, the precursor polymeric material comprises (a) 15 to 65 weight percent of the first monomer unit of formula (II), (b) 30 to 85 The second monomer unit of the formula (III) in weight percentage, and (c) 0 to 40 weight percent (or 5 to 40 weight percent) of the third monomer unit of the formula (IV). Each weight percentage value is based on the total weight of the monomer units in the precursor polymeric material.

Some embodiments of the precursor polymeric material contain 25 to 65 weight percent of the first monomer unit of formula (II), 30 to 75 weight percent of the second monomer unit of formula (III), and from 1 to 20 weight percent (or 5 Up to 20% by weight of the fourth monomer unit of formula (IV). Some embodiments contain 25 to 60 weight percent of the first monomer unit of formula (II), 30 to 75 weight percent of the second monomer unit of formula (III), and 1 to 30 weight percent (or 5 to 30 weight percent or 10 to 30 weight percent of the fourth monomer unit of formula (IV). in In still other embodiments, the monomer mixture contains from 30 to 65 weight percent of the first monomer unit of formula (II), from 30 to 70 weight percent of the second monomer unit of formula (III), and from 1 to 20 weight percent (or 5 to 20 weight percent or 10 to 20 weight percent of the fourth monomer unit of formula (IV). In still other embodiments, the monomer mixture contains from 30 to 60 weight percent of the first monomer unit of formula (II), from 30 to 65 weight percent of the second monomer unit of formula (III), and from 1 to 20 weight percent ( Or 5 to 20 weight percent or 10 to 20 weight percent of the fourth monomer unit of formula (IV). In a further embodiment, the monomer mixture contains 40 to 60 weight percent of the first monomer unit of formula (II), 30 to 55 weight percent of the second monomer unit of formula (III), and from 1 to 20 weight percent (or 5 to 20 weight percent or 10 to 20 weight percent of the fourth monomer unit of formula (IV). In still further embodiments, the monomer mixture contains from 20 to 40 weight percent of the first monomer unit of formula (II), from 50 to 70 weight percent of the second monomer unit of formula (III), and from 1 to 20 weight percent ( Or 5 to 20 weight percent or 10 to 20 weight percent of the fourth monomer unit of formula (IV). The weight percent value is based on the total weight of monomer units used in the precursor polymeric material.

The polymeric sorbent is formed by reacting a precursor polymeric material with a nitrogen-containing compound. The normally basic nitrogen-containing compound will react with the anhydride groups in the precursor polymeric material. That is, the nitrogen-containing compound will react with the monomer unit of formula (II) in the precursor polymeric material. This reaction results in the formation of a covalent bond that bonds the nitrogen-containing compound to the polymeric material.

The nitrogen-containing compound is ammonia, a compound having a single primary amine group (-NH ₂ ), or a compound having two or more groups of the formula -NHR wherein R is hydrogen or an alkyl group. Suitable alkyl R groups (i.e., alkyl monovalent alkane groups) often have from 1 to 20 carbon atoms. For example, an alkyl group can have at least 1 carbon atom, at least 2 carbon atoms, or at least 4 carbon atoms, and can have up to 20 carbon atoms, up to 18 carbon atoms, up to 16 carbon atoms, up to 10 carbons Atom, or up to 6 carbon atoms. In some embodiments, an alkyl group has from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, or from 1 to 4 carbon atoms.

The nitrogen-containing compound having a single primary amine group is a primary amine compound and generally does not include other primary and/or secondary amine groups. That is, there is a single nitrogen-containing group and it is -NH ₂ . The nitrogen-containing compound having at least two of the formula -NHR amine groups may have two or more primary amine groups (wherein R is equal to hydrogen), may have two or more secondary amine groups (wherein R is equal to the alkyl group), or There may be at least one primary amine group plus at least one secondary amine group.

Many suitable nitrogen-containing compounds have the formula (V).

R ₄ NHR ₁ (V) In the formula (V), the group R ₁ is hydrogen or an alkyl group. The group R ₄ is hydrogen, alkyl, or a -R ₅ -NHR ₆ group, or -(C=NH)-NH ₂ . The group R ₅ is a covalent bond, an alkylene group, an aryl group, an aralkyl group, a heteroalkyl group having one or more oxygen (-O-) groups, or one or more -NH- groups. The group is a heteroalkyl group. The group R ₆ is hydrogen, alkyl, or -(C=NH)-NH ₂ .

When both R ₁ and R ₄ are hydrogen, formula (V) is equal to ammonia. When R ₁ is hydrogen and R ₄ is alkyl, formula (V) is equivalent to a compound having a single primary amine group. When R ₄ is -R ₅ -NHR ₆ or when R ₄ is -(C=NH)-NH ₂ , formula (V) is equivalent to a compound having two or more groups of the formula -NHR.

The alkyl group suitable for R ₁ in formula (V) may have at least 1 carbon atom, at least 2 carbon atoms, or at least 4 carbon atoms, and may have up to 20 carbon atoms, up to 18 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, or up to 6 carbon atoms. In some embodiments, an alkyl group has from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, or from 1 to 4 carbon atoms.

In some embodiments, R ₄ in formula (V) is an alkyl group. To be suitable as a nitrogen-containing compound, when R ₄ is an alkyl group, R ₁ is equal to hydrogen. That is, the compound of the formula (V) is a primary amine compound. Alkyl groups suitable for R ₄ often have at least 1 carbon atom, at least 2 carbon atoms, or at least 4 carbon atoms, and may have up to 20 carbon atoms, up to 18 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, or up to 6 carbon atoms. In some embodiments, an alkyl group has from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, or from 1 to 4 carbon atoms. Examples of suitable primary amine compounds include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, and cyclohexylamine.

In some embodiments, R ₄ in formula (V) is a group of formula -R ₅ -NHR ₆ and the nitrogen-containing compound has formula (V-1).

R ₆ HN-R ₅ -NHR ₁ (V-1) These compounds have at least two amine groups of the formula -NHR. The alkyl group suitable for R ₆ in formula (V-1) may have at least 1 carbon atom, at least 2 carbon atoms, or at least 4 carbon atoms, and may have up to 20 carbon atoms and up to 18 carbon atoms. , up to 12 carbon atoms, up to 10 carbon atoms, or up to 6 carbon atoms. In some embodiments, an alkyl group has from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, or from 1 to 4 carbon atoms. The group R ₅ may be a covalent bond (ie, a nitrogen-containing compound ruthenium compound), or an alkylene group (ie, an alkyl group-derived divalent alkane group), an extended aryl group, an extended aralkyl group, having one or more An alkylene group having an oxygen (-O-) group or a heteroalkyl group having one or more -NH- groups.

Suitable alkylene R ₅ groups of formula (V-1) typically have at least 1 carbon atom, at least 2 carbon atoms, at least 3 carbon atoms, or at least 4 carbon atoms, and may have up to 20 A carbon atom, up to 16 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, or up to 6 carbon atoms. Some nitrogen-containing compounds have the formula (V-1), and R ₁ is hydrogen, and R ₅ is an alkyl group, and R ₆ is hydrogen. Examples of such nitrogen-containing compounds are alkyl diamines such as, for example, methylene diamine, ethylene diamine, propylene diamine, and butyl diamine. The nitrogen-containing compound of the formula (V-1) wherein R ₁ and R _{6 are both} equal to an alkyl group includes N , N '-dimethylethylenediamine.

In other embodiments of the compound of formula (V-1), the group R ₅ is a heteroalkyl group having at least one chain-O- or -NH- group (ie, a heteroalkyl group) a heteroaromatic hydrocarbon group having an alkane having a hetero atom in the chain). In other words, the heteroalkyl R ₃ group has one or more of the formula -R _a -[OR _b ] _n - or -R _a -[NH-R _b ] _n - groups, wherein each R _a and each R _b The alkyl group is independently alkyl, and n is an integer in the range of 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 6, or 1 to 4. Suitable R _a and R _b alkyl groups often have from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms. Heteroalkyl groups often have up to 30 carbon atoms and up to 16 heteroatoms, up to 20 carbon atoms and up to 11 heteroatoms, or up to 10 carbon atoms and up to 6 heteroatoms. These nitrogen-containing compounds can be represented by the formulae (V-2) and (V-3).

R ₆ HN-R _a -[OR _b ] _n -NHR ₁ (V-2)

R ₆ HN-R _a -[NH-R _b ] _n -NHR ₁ (V-3)

Some nitrogen-containing compounds have the formula (V-2), and R ₁ is hydrogen, R ₅ is a heteroalkyl group having a -O- group, and R ₆ is hydrogen. Examples of such nitrogen-containing compounds are poly(oxyalkylene)diamines such as polyethylene glycol diamine and polypropylene glycol diamine. The additional nitrogen-containing compound has the formula (V-3), and R ₁ is hydrogen, R ₅ is a heteroalkyl group having a -NH- group, and R ₆ is hydrogen. Such nitrogen-containing compounds may be, for example, compounds of the formula H ₂ N—[(CH ₂ ) _x NH] _y —(CH ₂ ) _x NH ₂ wherein x is an integer in the range from 1 to 4 and y is in the range 1 to An integer in the range of 10. Examples include diethylenetriamine, triethylenetetramine, and tetraethyleneamine.

The R ₅ group in the formula (V-1) may also be an aryl group or an aralkyl group. Suitable extended aryl groups (i.e., divalent groups of carbocyclic aromatic compounds) R ₅ groups typically have from 6 to 12 carbons and are often pendant phenyl or extended phenyl. Suitable extended aralkyl R ₅ groups refer to divalent groups having an aryl-substituted alkylene group, an alkyl-substituted extended aryl group, or an extended aryl group bonded to an alkylene group. The alkyl or alkyl moiety of the aralkyl group often has from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, or from 1 to 4 carbon atoms. The aryl or extended aryl moiety of the aralkyl group often has from 6 to 12 carbon atoms and is often phenyl or phenyl. Examples of the nitrogen-containing compound of the formula (V-1) wherein both R ₁ and R ₆ are hydrogen and the R ₅ is an aryl group include, but are not limited to, phenylenediamine.

Still other nitrogen-containing compounds have the formula (V-1) wherein R ₆ is as -(C=NH)-NH ₂ as shown in formula (V-4).

NH ₂ -(C=NH)-HN-R ₅ -NHR ₁ (V-4) For example, in some compounds, R ₁ is hydrogen and R ₅ is alkyl. One such compound is agmatine. Spermine may also be represented by other resonance structures, but is considered to be within the range of both formulae (V-1) and (V-4).

In other embodiments of formula (V), the R ₄ group is -(C=NH)-NH ₂ . The obtained compound has the formula (V-5).

H ₂ N-(C=NH)-NHR ₁ (V-5) When R ₁ is hydrogen, this compound is hydrazine.

Other suitable nitrogen-containing compounds are polyamines having at least three groups of the formula -NHR ¹ wherein R ¹ is hydrogen or alkyl. These compounds may have formula (VI).

R ₇ -(NHR ₁ ) _z (VI)

In formula (V), R ₁ is as defined above, and variable z is equal to at least 3 and may be up to 10, up to 8, up to 6, or up to 4. The R ₇ group is often a z-valent alkane group or a z-valent heteroalkane group. Suitable divalent alkane group of z often have a branched carbon atoms, and groups of four adjacent lines of at least three -CH ₂ -. Suitable z-valent heteroalkane groups often have a branched nitrogen atom and have three adjacent carbon atoms (eg, three are pendant alkyl or alkyl adjacent groups); or have a branched carbon atom and At least three of the four adjacent atoms are carbon (eg, three are adjacent groups of alkyl or alkyl groups). These z-valent heteroalkane groups often include one or more groups of the formula -R _c -[NH-R _d ] _p - wherein each R _{c is} independently alkyl to each R _d and the p is from 1 to 50 An integer ranging from 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 6, or 1 to 4. Suitable R _c and R _d alkyl groups often have from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms. a z-valent alkane group often has at least 2 carbon atoms, at least 3 carbon atoms, at least 4 carbon atoms, or at least 5 carbon atoms, and up to 20 carbon atoms, up to 16 carbon atoms, up to 12 carbon atoms , or up to 8 carbon atoms. The z-valent heteroalkane group often has up to 30 carbon atoms and up to 16 heteroatoms, up to 20 carbon atoms and up to 11 heteroatoms, or up to 10 carbon atoms and up to 6 heteroatoms.

Specifically, the R ₇ -(NHR ₁ ) _z polyamine includes various different polyimines. Some polyvalent imine comprises a plurality of branches or nitrogen atoms, and each of the three branches nitrogen atom of formula _{-R c - [NH-R d} ] p - group. The terminal groups of each branched segment are often of the formula -NHR ₁ group, such as -NH ₂ . Examples include a variety of different branched polyethylenimines. Another specific polyamine is 2-(aminomethyl)-2-methyl-1,3-propanediamine, wherein R ₇ is a trivalent alkane group (ie, a carbon branching atom utilizes three adjacent ones) An alkyl group and an adjacent methyl group are attached to four carbon atoms), each R ₁ is hydrogen, and z is equal to 3.

In many embodiments, nitrogen-containing compounds such as Formula (V) (including Formulas V-1 through V-5) and Formula (VI) have a molecular weight (or weight average molecular weight) of no greater than 2000 Daltons (Da). . For example, the molecular weight (or weight average molecular weight) is not more than 1500 Da, not more than 1000 Da, not more than 750 Da, not more than 500 Da, or not more than 250 Da.

The nitrogen-containing compound will react with the monomer unit of formula (II) in the precursor polymeric material. This reaction Will cause the nitrogen-containing compound to be covalently bonded to the polymeric material, and the reaction site is a single monomer of formula (II) Anhydride group in the element

(-(CO)-O-(CO)-). The ring structure will generally open to form a monomeric unit of formula (VII), formula (VIII), or a mixture thereof.

(VII)

In the formulae (VII) and (VIII), if a nitrogen-containing compound of the formula (V) is used, the group A is equal to -NR ₁ R ₄ , and if a nitrogen-containing compound of the formula (VI) is used, the group A is equal to -NR ₁ -R ₇ (NHR ₁ ) _z-1 . Alternatively, a ring structure may be formed, such as shown in formula (IX), wherein A ₁ is a divalent group and is equivalent to a compound of formula (V) or a compound of formula (VI) equal to the removal of two hydrogen atoms.

In the precursor polymeric material, up to 2 moles of nitrogen-containing compound may be added per mole of the (II) monomer unit. That is, based on the total number of moles of the monomer units of formula (II), up to 200 mole percent of the nitrogen-containing compound can be reacted with the precursor polymeric material. In some embodiments, the nitrogen-containing compound is added in an amount of up to 175 mole percent, up to 150 mole percent, up to 125 mole percent, or at most, based on the total moles of monomeric units of formula (II) in the precursor polymeric material. 100 mole percentage. The amount of nitrogen-containing compound may be at least 1 mole percent, at least 2 mole percent, at least 5 mole percent, at least 10 mole percent, at least 20, based on the total moles of monomeric units of formula (II) in the precursor polymeric material. Percent of moles, at least 50 mole percent, at least 75 mole percent, or at least 100 mole percent. In some embodiments, the amount of nitrogen-containing compound is in the range of from 1 to 200 mole percent, based on the total moles of monomer units of formula (II) in the precursor polymeric material, from 10 to 200 moles. Within the range of percentages of ears, in the range of 50 to 200 mole percent, in the range of 50 to 150 mole percent, in the range of 75 to 150 mole percent, in the range of 75 to 125 mole percent, Or within the range of 100 to 200 moles.

In order to react a nitrogen-containing compound with a precursor polymeric material, the nitrogen-containing compound is often dissolved in water and/or a suitable organic solvent. Suitable organic solvents are those which can dissolve nitrogen-containing compounds but do not react therewith. Examples of organic solvents include, but are not limited to, alcohols, ethers (such as tetrahydrofuran and diethyl ether), and various chlorinated solvents (such as dichloromethane and chloroform). The concentration of the nitrogen-containing compound in water and/or organic solvent may be any suitable amount depending on the solubility of the nitrogen-containing compound. In some embodiments, the concentration of the nitrogen-containing compound in water and/or organic solvent is in the range of 1 to 40 weight percent, in the range of 1 to 30 weight percent, and in the range of 1 to 20 weight percent, Or in the range of 1 to 10 weight percent.

The solution of the nitrogen-containing compound is mixed with the precursor polymeric material. The reaction between the nitrogen-containing compounds can occur at room temperature or can occur by heating the mixture to a temperature above room temperature. For example, the mixture can be heated at a temperature ranging from 30 to 120 ° C for several hours to several days. In some embodiments, the suspension is heated at 30 to 100 ° C, 40 to 90 ° C, 50 to 90 ° C, or 60 to 80 ° C for 12 to 24 hours.

The particle size of the sorbent particles used with the filter holder (having any type) can vary as desired. In various embodiments, the sorbent particles can have a particle size of at least about 4 mesh (ie, a particle size nominally less than 4.8 mm), 6 mesh (nominal particle size less than 3.4 mm), and 8 mesh (less than about 2.4 mm). Particle size), 12 mesh (less than about 1680 microns), at least about 16 mesh (<1190 microns), at least about 20 mesh Standard US mesh size (grade) of (<840 microns), at least about 40 mesh (<425 microns), or at least about 60 mesh (<250 microns). In a further embodiment, the sorbent particles can have a particle size of no greater than about 325 mesh (ie, nominally greater than 44 microns); 230 mesh (>63 microns), 140 mesh (>105 microns), 100 mesh (> Standard US mesh grade of 150 micron), 80 mesh (>180 micron), 60 mesh (>250 micron), 50 mesh (>300 micron), or 45 mesh (>355 micron).

It will be understood by those of ordinary skill that all such mesh sizes correspond to nominal grades rather than absolute standards; for example, if the material is described as a 12 mesh material, about 95% or more of the particles will pass through the 12 mesh screen (and Thus the size will be nominally less than about 1680 microns). If the material is described as 12 x 20 mesh, then 95% or more of the material will pass through the 12 mesh screen (ie, particles less than about 1680 microns will pass through the 12 mesh screen) and be held by the 20 mesh screen (ie, greater than Particles of approximately 841 microns will not pass through the 20 mesh screen). Mixtures of sorbent particles having different size ranges (e.g., bimodal mixtures) can be employed if desired. The sorbent particles 100 can be processed to have any desired particle size distribution. Such processing can include, for example, sieving particles and/or mechanically grinding the particles as desired.

The porosity of the polymeric sorbent can be characterized by an adsorption isotherm of the porous material to an inert gas such as nitrogen or argon under low temperature conditions (e.g., liquid nitrogen at 77 °K). The adsorption isotherm is typically obtained by measuring the sorption of a porous polymeric sorbent against an inert gas such as argon at multiple relative pressures ranging from about 10 ^-6 to about 0.98 + 0.01. The isotherm is then analyzed using a variety of methods, such as calculating the specific surface area using the BET (Brunauer-Emmett-Teller) method, and characterizing the porosity using, for example, Density Functional Theory (DFT). With pore size distribution.

The term "surface area" refers to the total area of the surface of the material, and the surface includes an inner surface that can enter the hole. The surface area is generally determined from the adsorption of an inert gas (for example, nitrogen or argon) on the surface of the material under a relatively low pressure condition (for example, under liquid nitrogen at 77 °K). Isothermal map is calculated. The term "BET specific surface area" is the surface area per gram of material (usually m ² /g), which is usually calculated from the adsorption isothermal data of an inert gas at a relative pressure of 0.05 to 0.30 using the BET method. get.

The polymeric sorbent typically has a lower BET specific surface area than the polymeric material of the precursor. Opening the anhydride group to form the monomer units of the formulae (VII) and (VIII) may sufficiently increase the degree of freedom of configuration in the main chain, resulting in a decrease in porosity. Furthermore, hydrogen bonding between the nitrogen-containing groups in the monomeric units of formula (VII), (VIII), and (IX) may limit or block the entry of pores. Because of this reduced porosity, it is often desirable to prepare an anhydride group precursor polymer material that has the highest BET specific surface area but still has sufficient reactivity with the nitrogen-containing compound.

The polymeric sorbent typically has a BET specific surface area equal to at least 25 m ² /gram. In some embodiments, the BET specific surface area is at least 50 m ² /gram, at least 75 m ² /gram, or at least 100 m ² /gram. The BET specific surface area may be up to 700 m ² /g or more, up to 600 m ² /g, up to 500 m ² /g, up to 400 m ² /g, up to 300 m ² /g, or up to 200 m ² /g. In some embodiments, the BET specific surface area is in the range of 25 to 600 m ² /g, in the range of 25 to 500 m ² /g, in the range of 25 to 400 m ² /g, in the range of 25 to 300 m ² /gram, It is in the range of 50 to 300 m ² /g, in the range of 50 to 200 m ² /g, in the range of 75 to 200 m ² /g, or in the range of 50 to 100 m ² /g.

The BET specific surface area is at least partially due to the presence of microvoids and/or mesopores in the polymeric sorbent. The argon adsorption isotherm of the polymeric sorbent (at 77 °K) shows that a large amount of argon is adsorbed when the relative pressure is less than 0.1, which means that micropores are present. When at a relative pressure of between 0.1 and about 0.95, the adsorption will gradually increase. This increase indicates that the majority of the mesopores have a large pore size distribution.

In some embodiments, at least 20 percent of the BET specific surface area of the polymeric sorbent is due to the presence of microvoids and/or mesopores. The percentage of BET specific surface area due to the presence of microvoids and/or mesopores may be at least 25 percent, at least 30 percent, at least 40 percent, at least 50 percent, or at least 60 percent. In some embodiments, the percentage of BET specific surface area due to the presence of microvoids and/or mesopores may be up to 90 percent or more, up to 80 percent or more, or up to 75 percent or more.

The porous polymeric sorbent has a total pore volume equal to at least 0.05 cm ³ /gram. The total pore volume is calculated from the argon adsorption amount at a liquid nitrogen temperature (77 °K) at a relative pressure (p/p°) equal to about 0.98 (e.g., 0.98 + 0.01). In some embodiments, the total pore volume based at least 0.075cm ³ / g, at least 0.10cm ³ / g, at least 0.15cm ³ / g, at least 0.20cm ³ / g, at least 0.25cm ³ / g, or at least 0.30cm ³ /g. The total pore volume can be tied up to 1.0cm ³ / g or even higher, up to 0.9cm ³ / g, up to 0.8cm ³ / g, up to 0.7cm ³ / g, up to 0.6cm ³ / g, up to 0.5cm ³ / g Up to 0.4 cm ³ /g, up to 0.3 cm ³ /g, or up to 0.2 cm ³ /g. The pore volume is often in the range of 0.05 to 1 cm ³ /g, in the range of 0.05 to 0.8 cm ³ /g, in the range of 0.05 to 0.6 cm ³ /g, in the range of 0.05 to 0.4 cm ³ /g, in the range of 0.05 to 0.2. Within the range of cm ³ /gram, or in the range of 0.75 to 0.2 cm ³ /gram.

The structure of the divinylbenzene/maleic anhydride polymeric material is particularly suitable for use as a precursor polymeric material for porous polymeric sorbents. If the monomer unit of formula (IV) from the styrenic monomer is low in content, the divinylbenzene/maleic anhydride precursor polymeric material has alternating monomer units derived from divinylbenzene and maleic anhydride. This structure results in a high degree of cross-linking and contributes to the formation of a porous polymeric material, especially a porous polymeric material having a high microvoid and/or mesoporous content.

In some embodiments, the polymeric sorbent further comprises an acid-base indicator. The acid-base colorimetric indicator (i.e., the dye which is discolored when converted from an acid to a basic form (usually an organic dye) may be added simultaneously with the nitrogen-containing compound or may be added after the addition of the nitrogen-containing compound. The choice of the acid - base typically has a pK _b of the colorimetric indicator is lower than the pK _b of the nitrogen-containing compound. That is, when all or a significant portion of the available nitrogen-containing groups on the polymeric sorbent have reacted with the aldehyde, the selected acid-base colorimetric indicator will transition from the first color to the second color. This color change indicates that the sorption capacity of the polymeric sorbent for the aldehyde has been reached or nearly reached. As used herein, the term "close to being reached" means that at least 60 percent or more of the capacity has been reached (ie, at least 60 percent or more of the available sorbing sites have been used for sorption). aldehyde). For example, at least 70 percent, at least 80 percent, at least 90 percent, or at least 95 percent of the sorption sites have been used to sorb aldehydes.

Since pK _{b of} nitrogen-containing compounds is known, one having ordinary knowledge in the art can easily select an acid-base colorimetric indicator having a lower pK _b value. In some applications, the pK _b value of pH than at least the difference between the nitrogen-containing compound-based pK _b of a color indicator, at least 2, at least 3, or at least 4. The pK _{b of the} acid-base colorimetric indicator is often in the range of 3 to 10.

Examples of acid-base colorimetric indicators include, but are not limited to, methyl red, bromoxylenol blue, pararosaniline, chrysoidine, thymol blue, Methyl yellow, bromophenyl blue, Congo red, methyl orange, bromocresol green, azolitmin, bromocresol purple, bromothymol blue, phenol red, neutral red, Naphtholphthalein, cresol red, phenolphthalein, and thymolphthalein.

The acid-base colorimetric indicator can be added to the polymeric sorbent by any suitable method. In some embodiments, the polymeric sorbent is immersed in the solution of the acid-base colorimetric indicator for at least 10 minutes, at least 20 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 4 hours, or at least 8 hour. The solution of the acid-base colorimetric indicator is often in the range of 5 to 10 mg/ml. Approximately 0.5 g of a polymeric sorbent is often soaked in about 10 ml of this solution.

Polymeric sorbents offer significant advantages over immersion trap based sorbents. The capture agent is typically simply adsorbed onto a matrix material such as, for example, activated carbon. That is, the capture agent is typically not covalently attached to the matrix material and may migrate. In contrast, the polymeric sorbents described herein have covalently attached nitrogen-containing groups that will interact with the aldehyde and will not migrate.

In some embodiments in which an acid-base indicator is present, the action of the polymeric sorbent particles 100 can provide, at least in part or predominantly, a visual indication that a gaseous aldehyde (eg, formaldehyde) is present in the polymeric sorbent particles. In the exposed air. That is, the collection of such polymeric sorbent particles 100 present on a suitable filter holder 10 can provide similar functionality to, for example, a well-known gas detection device of the type exemplified by the Dräger tube.

In another aspect, a method of sorbing an aldehyde by a polymeric sorbent particle 100 supported on a filter holder 10 of an air filter 1 is provided. The polymeric sorbent is in the form of particles and is the reaction product of (a) the precursor polymeric material and (b) the nitrogen containing compound. As noted above, the sorbent can be, for example, ground and/or sieved to any suitable particle size distribution. The precursor polymeric material comprises a polymeric product of a polymerizable composition comprising (1) from 8 to 65 weight percent of maleic anhydride based on the total weight of the monomers in the polymerizable composition, (2) based on The total weight of the monomers in the polymerizable composition, from 30 to 85 weight percent of divinylbenzene, and (3) from 0 to 40 weight percent of the styrene type based on the total weight of the monomers in the polymerizable composition The styrene type single system styrene, alkyl substituted styrene, or a combination thereof. The nitrogen-containing compound is selected from the group consisting of ammonia, a compound having a single primary amine group (-NH ₂ ), or a compound having at least two amine groups of the formula -NHR wherein R is hydrogen or an alkyl group. Suitable nitrogen-containing compounds generally have the formulae (V) and (VI) as described above.

The porous polymerizable sorbent adsorbs aldehyde. Suitable aldehydes have the formula (I).

R ₂ -(CO)-H (I) wherein R ₂ is hydrogen, alkyl, vinyl, aryl, or alkyl substituted aryl. Suitable alkyl groups generally have from 1 to 10 carbon atoms, from 1 to 6 carbon atoms, from 1 to 4 carbon atoms, from 1 to 3 carbon atoms, or from 1 carbon atom. The aryl group can have up to 12 carbon atoms or up to 6 carbon atoms. The aryl group is often a phenyl group. The aryl group may be substituted with an alkyl group such as an alkyl group having 1 to 4 carbon atoms or 1 to 3 carbon atoms.

The aldehyde is adsorbed by a polymeric sorbent when it is in the form of a gas or a vapor. Thus, the molecular weight of the aldehyde is generally no greater than 200 grams per mole, no greater than 150 grams per mole, no greater than 100 grams per mole, no greater than 75 grams per mole, or no greater than 50 grams per mole. Suitable aldehydes include, but are not limited to, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentanal (valeraldehyde), isovaleraldehyde, hexanal, benzaldehyde, 2,5-dimethylbenzaldehyde , 2,4-dimethylbenzaldehyde, 2,3-dimethylbenzaldehyde, tolualdehyde (o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, and mixtures thereof), acrolein, and crotonaldehyde .

The aldehyde can be adsorbed at room temperature or at any desired temperature, such as in the range of -30 ° C to 150 ° C, -30 ° C to 100 ° C, or in the range of -20 ° C to 50 ° C.

In another aspect, a composition is provided comprising a porous polymeric sorbent supported on a filter holder and an aldehyde adsorbed on the porous polymeric sorbent. The polymerizable sorbent and the aldehyde system are the same as those described above. The aldehyde can be reacted with any of the primary or secondary amine groups present on the polymeric sorbent. In some embodiments, the polymeric sorbent uses a compound of any one of formula (V), (V-1), (V-4), (V-5), or (VI) as the nitrogen-containing compound. Compounds are formed.

List of exemplary embodiments

Embodiment 1 is an air filter comprising a filter holder supporting polymeric sorbent particles, wherein the polymeric sorbent comprises the following reaction product: (a) a precursor of a polymerization product comprising a polymerizable composition a polymeric material comprising (1) from 8 to 65 weight percent of maleic anhydride based on the total weight of the monomers in the polymerizable composition; (2) based on the total amount of monomers in the polymerizable composition a weight of 30 to 85 weight percent of divinylbenzene; and (3) from 0 to 40 weight percent of the styrene monomer based on the total weight of the monomers in the polymerizable composition, wherein the styrene type single system Styrene, alkyl-substituted styrene, or a combination thereof; and (b) a nitrogen-containing compound selected from the group consisting of ammonia, a compound having a single primary amine group (-NH2), or having at least two formulas NHR An amine group compound wherein R is hydrogen or an alkyl group, and wherein the polymerizable sorbent is present in the form of porous particles.

Embodiment 2 is the air filter of embodiment 1, wherein the filter holder comprises a substrate having at least one major surface, at least some of the polymeric sorbent particles being disposed on the at least one major surface. Embodiment 3 is the air filter of embodiment 2, wherein the polymerizable sorbent particles are present in a single layer on the major surface of the substrate. Embodiment 4 is the air filter of embodiment 1, wherein the filter holder comprises a porous gas permeable material having polymerizable sorbent particles disposed on a major surface thereof and/or disposed The interior of the material is at least in the vicinity of one of the major surfaces of the material, the polymeric sorbent particles. Embodiment 5 is the air filter of Embodiment 4, wherein the polymerizable sorbent particles are disposed inside the entire porous gas permeable material.

Embodiment 6 is the air filter of any of embodiments 1 to 5, wherein the air filter consists essentially of the filter holder. Embodiment 7 is Embodiments 1 to 6 The air filter of any of the preceding claims, wherein the filter holder comprises a sheet of material exhibiting a major plane and exhibiting a thickness of less than about 3 mm, and configured to allow the airflow to be at least substantially perpendicular to the The filter holder is passed through one of the major planes of the sheet material. Embodiment 8 is the air filter of any one of embodiments 1 to 3 and 6 to 7, wherein the filter holder comprises a netting having a major surface to which at least some of the polymeric sorbent particles adhere .

Embodiment 9 is the air filter of any of embodiments 1 to 7, wherein the filter holder comprises a web exhibiting an interior, and wherein the polymeric sorbent particles are disposed within the interior of the web At least part of it. Embodiment 10 is the air filter of embodiment 9, wherein the polymerizable sorbent particles are disposed throughout the interior of the fiber web. Embodiment 11 is the air filter of any of embodiments 9 to 10, wherein the mesh is a nonwoven web. Embodiment 12 is the air filter of Embodiment 11, wherein the nonwoven web is a meltblown web. The air filter of any one of embodiments 9 to 12, wherein at least some of the fibers of the fiber web are each bonded to at least one polymerizable sorbent particle.

Embodiment 14 is the air filter of any of embodiments 1 to 13, wherein the filter holder is a layer of a plurality of gas permeable components. Embodiment 15 is the air filter of embodiment 14, wherein the multilayer venting component comprises at least one layer different from the filter holder and which exhibits a particle filtration layer of less than 50 percent penetration. Embodiment 16 is the air filter of embodiment 15, wherein the particle filter layer comprises an electret portion.

The air filter of any one of embodiments 1 to 16, wherein the filter holder exhibits a filter medium that is less than 50 percent penetration.

Embodiment 18 is the air filter of any of embodiments 1 to 17, wherein the filter holder is pleated.

The air filter of any one of embodiments 1 to 18, wherein the air filter is a frame type air filter configured to be inserted into an air filter socket of an air treatment device, The air treatment device is selected from the group consisting of a forced air heating unit, a forced air cooling unit, a forced air heating/cooling unit, an indoor air purifier, and a cabin air filter for an electric vehicle. unit.

Embodiment 20 is the air filter of any of embodiments 1, 6, and 14 to 16, wherein the filter holder comprises a honeycomb having a through hole in which the sorbent particles are disposed.

Embodiment 21 is the air filter of any of embodiments 1 to 5 and 7 to 18, wherein the filter holder provides a layer of a filtered facepiece respirator. Embodiment 22 is the air filter of embodiment 21, wherein the filtering facepiece respirator is selected from the group consisting of a flat-fold respirator and a molded respirator.

The air filter of any one of embodiments 4 to 18, wherein the filter holder comprises a container having an interior in which the polymerizable sorbent particles are disposed and having at least one Air port and at least one air outlet. Embodiment 24 is the air filter of embodiment 23, wherein the filter holder comprises a filter cartridge. Embodiment 25 is the air filter of embodiment 24, wherein the filter is configured for use with a personal protective device selected from the group consisting of: a half-face negative pressure respirator, a total negative pressure Respirators, escape hoods, and powered air purifying respirators.

Embodiment 26 is a method of capturing at least some aldehyde from air, the method comprising: positioning an air filter comprising a filter holder, the filter holder comprising the polymeric sorption of any one of embodiments 1 to 25. The particles are such that the polymeric sorbent particles are exposed to air and at least some of the aldehyde present in the air is adsorbed onto the polymeric sorbent particles, wherein the aldehyde has the formula (I): R2 -(CO)-H, wherein R2 is hydrogen, alkyl, vinyl, or aryl, and wherein the molecular weight of the aldehyde of formula (I) is no greater than 200 g/mole. Embodiment 27 is the method of embodiment 26, wherein R2 is hydrogen or methyl.

The method of any one of embodiments 26 to 27, wherein the filter holder exhibits a major surface, and wherein the air is present in the form of a flow of air moving in one direction, the direction being at least substantially One of the major surfaces of the filter holder is planarly aligned. The method of any one of embodiments 26 to 27, wherein the filter holder allows a gas stream to pass therethrough, and wherein the air is present in the form of an air stream that is at least substantially perpendicular to the filtration At least a portion of the filter holder passes through one of the major surfaces of the holder.

Embodiment 30 is the method of any one of embodiments 26 to 27, which is performed using the air filter of any one of embodiments 1 to 25.

Embodiment 31 is a method of making an air filter comprising a filter holder comprising polymer sorbent particles, the method comprising: (a) providing a precursor of a polymeric product comprising a polymerizable composition a polymeric material comprising (1) from 8 to 65 weight percent of maleic anhydride based on the total weight of the monomers in the polymerizable composition; (2) based on the total weight of the monomers in the polymerizable composition 30 to 85 weight percent of divinylbenzene; and (3) 0 to 40 based on the total weight of the monomers in the polymerizable composition a percentage by weight of a styrenic monomer, wherein the styrene-type single system styrene, an alkyl-substituted styrene, or a combination thereof; and (b) reacting the precursor polymeric material with a nitrogen-containing compound to form the a polymerizable sorbent selected from the group consisting of ammonia, a compound having a single primary amine group (-NH2), or a compound having at least two amine groups of the formula -NHR, wherein R is hydrogen or an alkyl group, Wherein the polymeric sorbent has a covalently attached nitrogen-containing group and is in the form of particles; and (c) the polymeric sorbent particles are supported on a filter holder.

Embodiment 32 is the air filter of any of embodiments 1 to 25, wherein the air filter further comprises at least one secondary sorbent. Embodiment 33 is the air filter of embodiment 32, wherein the at least one secondary sorbent comprises activated carbon.

The air filter of any one of embodiments 1 to 25 and 32 to 33, wherein the polymerizable composition comprises 15 to 65 weight percent of maleic anhydride, 30 to 85 weight percent of divinylbenzene, And 0 to 40% by weight of the styrene type monomer. The air filter of any one of embodiments 1 to 25 and 32 to 33, wherein the polymerizable composition comprises 25 to 65 weight percent of maleic anhydride, 30 to 75 weight percent of divinylbenzene, With 1 to 20 weight percent of the styrene type monomer. Embodiment 36 is the air filter of any one of embodiments 1 to 25 and 32 to 33, wherein the polymerizable composition comprises 30 to 65 weight percent of maleic anhydride, 30 to 70 weight percent of divinylbenzene, With 1 to 20 weight percent of the styrene type monomer.

Example 37 lines 1 to 25 and 32 to 36 in an air filter of any one of embodiment, wherein the nitrogen-containing compound having the formula _{(V): R 4 NHR 1} , in which R ₁ hydrogen or alkyl train; R ₄ lines Hydrogen, alkyl, formula -R ₅ -NHR ₆ group, or -(C=NH)-NH ₂ ; R ₅ is a covalent bond, an alkylene group, an aryl group, an aralkyl group, having one or more a heteroalkyl group of an oxygen (-O-) group, or a heteroalkyl group having one or more -NH- groups; and R ₆ is hydrogen, an alkyl group, or -(C=NH)-NH ₂ . Embodiment 38 is the air filter of Embodiment 37, wherein the nitrogen-containing compound of the formula (V) has a molecular weight of not more than 2000 Daltons.

The air filter of any one of embodiments 1 to 25 and 32 to 36, wherein the nitrogen-containing compound has the formula (VI): R ₇ -(NHR ₁ ) _z , wherein R ₇ is a z-valent alkane group a group or a z-valent heteroalkane group; and z is an integer in the range of from 3 to 10.

Embodiment 40 is the air filter of any one of embodiments 1 to 25 and 32 to 39, wherein the polymerizable sorbent further comprises an acid-base dye.

Instance Analysis and characterization program

Porosity and gas adsorption experiments are performed in a procedure similar to that described in U.S. Provisional Patent Application Serial No. 62/269,613, the disclosure of which is incorporated herein by reference.

Working example A

A batch of precursor polymeric material is produced in a substantially similar manner as described in Example 14 of U.S. Provisional Patent Application Serial No. 62/269,613, issued toW. The precursor polymer material has a BET specific surface area (SA _BET ) in the range of about 320 m ² /g, and a total pore volume in the range of about 0.250 cm ³ /g (partial pressure (p/p° equal to 0.98). Under measurement).

The polymeric precursor material was sieved to 8 x 12 mesh. In a 32 ounce jar, 164 mL (2.45 moles) of ethylenediamine (EDA) was dissolved in 492 mL of ethanol (EtOH). 100 g of a polymerizable precursor material was added to this solution. The wide mouth bottle is capped and placed on the drum. The jar was rolled at room temperature for 18 hours. The solid was isolated by vacuum filtration and then washed with EtOH. The solid was placed in a 32 oz wide mouth bottle and then 500 mL of EtOH was added to the wide mouth bottle. The solid was allowed to stand in EtOH for 4 hours. The solid was again separated by vacuum filtration and then washed with EtOH. The solid was then dried in a batch oven at 120 ° C for 3 hours. This product (polymeric sorbent) has a BET specific surface area (SA _BET ) in the range of about 140 m ² /g, and a total pore volume (p/p° equals 0.98) in the range of about 0.17 cm ³ /g.

An air filter (sold for use with an indoor air purifier designated as KJEA-400 available from 3M Company, Shanghai, China) was obtained. The filter as obtained comprises a honeycomb scaffold filled with a sorbent, the sorbent being activated carbon and which appears to be in the form of particles in the range of 6 x 12 mesh. The protective screen is removed from one of the main sides of the honeycomb and the activated carbon is discarded (from each of the through holes of the honeycomb) and replaced by a substantially equivalent volume of the above polymeric sorbent. (However, since the density of the polymeric sorbent is significantly lower, the total weight of the polymeric sorbent used is only about 40% by weight of the activated carbon it replaces.) Replace the protective screen to provide Working example A air filter.

A similar honeycomb-based air filter (if the supplied activated carbon remained therein) was obtained and used as a comparative example.

A formaldehyde capture efficiency test was performed on the challenge of two filter samples for 50 parts per million (by volume) of formaldehyde at 50% relative humidity and 156 LPM airflow. Formaldehyde is produced by heating the paraformaldehyde solution in a 50% humid air stream. The formaldehyde concentration was measured using a photoacoustic detector from California Analytical Instruments. The formaldehyde capture efficiency is calculated by efficiency % = 100 * (1-C _downstream (filter in use) / C _downstream (unused filter)), where the concentration of formaldehyde in the C-system flowing air stream. Figure 9 presents (for each air filter/sorbent sample) a graph of formaldehyde capture efficiency as a function of time; Figure 10 presents the data of Figure 9, where the time (x) axis is used per unit area using each sorbent The quality (g/m2) is normalized.

The total formaldehyde loading capacity at 95% formaldehyde breakthrough was obtained from the formaldehyde capture efficiency map. This is done by fitting the line to the graph using a standard fitting method and extrapolating the line to the x-axis point when the formaldehyde capture efficiency has dropped to 5% (using normalized data). The area under the line is then calculated and multiplied by the mass flow rate of formaldehyde and the mass of the sorbent per unit area to obtain the formaldehyde capacity (reported in grams of formaldehyde absorbed per square meter of filtration area).

In Table A, the test area is the total area of the pores exposed to the honeycomb of the moving gas stream (same for both filter samples). Formaldehyde capacity is from the above The formaldehyde loading capacity obtained under the breakthrough of 95% formaldehyde was obtained. The sorbent weight is the sorbent load per unit area of the filter sample. The sorbent capacity is the formaldehyde capacity divided by the sorbent weight, so the sorbent capacity is reported as (by percentage) the mass of formaldehyde captured per sorbent mass used. The initial efficiency is obtained by extending the formaldehyde capture efficiency map (Figure 10) to the x-axis zero value to provide an estimate of the efficiency of the sorbent in capturing formaldehyde when the sorbent is initially exposed to formaldehyde.

Working example B

A batch of precursor polymerizable material was fabricated in a manner substantially similar to that described above for Working Example A. This procedure was repeated a total of six times to accumulate 1256 grams of a 20x60 mesh sieved polymeric precursor material. In a 5 gallon plastic vessel, 2056 mL (30.8 moles) of EDA was dissolved in 8225 mL of EtOH. 1256 g of a polymerizable precursor material was added to this solution. The vessel is capped and placed on the drum. The vessel was rolled at room temperature for 18 hours. The solid was isolated by vacuum filtration and then washed with EtOH. The solid was placed in a 5 gallon plastic vessel and then 8.0 L of EtOH was added to the vessel. The solid was allowed to stand in EtOH for four hours. The solid was again separated by vacuum filtration and then washed with EtOH. The solid was then dried in a batch oven at 120 ° C for 3 hours. This product (polymeric sorbent) has a BET specific surface area (SA _BET ) in the range of about 140 m ² /g, and a total pore volume (p/p° equals 0.98) in the range of about 0.17 cm ³ /g.

A three-layer stack is formed in a process similar to that described in U.S. Patent Application Publication No. 2012272829, the entire disclosure of which is incorporated herein by reference. In short, the first cover layer is unwound to the mobile On the surface of the collector, a hybrid mixture of thermoplastic meltblown fibers and polymeric sorbent particles is deposited onto the first cover layer, and the second cover layer is formed while the meltblown fibers are still relatively warm and viscous Contact with the meltblown fiber/sorbent particle layer. As a result, the intermediate meltblown fiber/sorbent particle layer is melt bonded to the first cover layer and the second cover layer.

The first type of cover is a static-type, melt-spun nonwoven nonwoven medium of the general type disclosed in US Pat. No. 7,947,142. The first cover layer was quite stiff and exhibited the following properties (measured as a flat web): basis weight of 107 g/m ² , solidity of 10%, and percent penetration of 20 (DOP). The second cover layer is a spunbonded polypropylene nonwoven medium of the general type described in U.S. Provisional Patent Application Serial No. 61/873,110, the entire disclosure of which is incorporated herein. The second layer had minimal stiffness, had a basis weight of 44 g/m ² , and exhibited a drag resistance of 0.34 mm H ₂ O at a test speed of 14 cm/s. Meltblown fibers are made from a thermoplastic elastomer available from Dow under the trade designation VERSIFY 4301; the meltblown fibers comprise about 16% by weight of the intermediate (meltblown fibers/sorbent) layer under the meltblown conditions employed.

The resulting three-layer web exhibited an area weight of 533 g/m ² , an 8.41 mm H ₂ O flow resistance at a test speed of 14 cm/s, and a total sorbent content of 321 g/m ² . The web was formed into a pleated configuration using a flap pleating machine having a pleat height of 25 mm and a pleat spacing of 12.5 mm. The web can be directly pleated during manufacture and does not require lamination of any reinforcing layer (eg, wire mesh eye) to successfully form and maintain the shape of the pleats, except for attachment to maintain a consistent pleat spacing Beyond the thin strip of the pleat tip. Most of the network stiffness appears to be contributed by the first overlay.

The formaldehyde capture efficiency test was performed on the pleated working example B air filter sample; the results are shown in Fig. 11 together with the above comparative example (honey-activated carbon). In this case Next, the best fit of the working example B data is found to be an exponential curve rather than a linear fit. Necessary is to extrapolate the honeycomb (comparative) data to the point where the formaldehyde capture efficiency has dropped to 5%; however, the actual data for Work Case B is obtained at this time, so there is little or no extrapolation required. .

Working example C

A batch of precursor polymerizable material was fabricated in a manner substantially similar to that described above for Working Example A. The difference is that the batch size is much smaller (programs are performed in 300 cc vessels instead of 2.0L vessels) and are performed at higher solids percentages; however, the monomer composition is the same (34 wt. % divinylbenzene, 57.5) Wt. % maleic anhydride, and 8.5 wt.% styrene monomer).

In a 32 ounce jar, 115 mL (1.72 moles) of EDA was dissolved in 230 mL of EtOH. To this solution was added 17.5 g of a polymerizable precursor material (screened to 8 x 12 mesh). The jar was capped and placed in a sand bath at 80 °C. The suspension was heated at this temperature for 18 hours. The solid was isolated by vacuum filtration and then washed with EtOH. The solid was placed in an 8 oz wide mouth bottle and then 200 mL of EtOH was added to the wide mouth bottle. The solid was allowed to stand in EtOH for 4 hours. The solid was again separated by vacuum filtration and then washed with EtOH. The solid was then dried at 80 ° C under high vacuum for 8 hours. This product (polymeric sorbent) has a BET specific surface area (SA _BET ) in the range of about 140 m ² /g, and a total pore volume (p/p° equals 0.98) in the range of about 0.17 cm ³ /g.

Netting based brand name DELNET R0412-10PR available from Delstar Technologies; reportedly netting having 60g / m ² of weight group. The netting comprises two sets of filaments oriented substantially perpendicular to each other to form an array of substantially rectangular through holes (openings) each having a size of about 1.7 x 0.7 mm. A pressure sensitive adhesive precursor (coating solution) was applied to both sides of the netting, and the solvent was dried to leave the (acrylic) PSA at a basis weight of about 30 g/m ² on each side in the netting On the side. The coated netting was also formed in the form of pleats on a flap pleating machine with a pleat height of 25 mm and a pleat spacing of 12.5 mm. After the pleating process is completed, the sorbent particles are manually sprayed onto both sides of the pleated netting such that the sorbent particles adhere to the PSA present on the major surface of the pleated netting. The sorbent was provided at a basis weight of about 800 g/m ² (the sorbent particles on both sides were counted).

The formaldehyde capture efficiency test was performed on the pleated working example C air filter sample; the results are shown in Fig. 12 together with the above comparative example (honeycomb-activated carbon). It is necessary to extrapolate the honeycomb (comparative) data to the point where the formaldehyde capture efficiency has dropped to 5%; however, the actual data of the work example C is obtained at this time, so the extrapolation required is little or no extrapolation is required. .

As demonstrated in the above working examples, the polymeric sorbent particles disclosed herein can exhibit enhanced when disposed on a filter holder to form an air filter, as compared to, for example, a representative activated carbon sorbent. The ability to capture formaldehyde. This has been demonstrated on a variety of filter holders (eg, honeycombs, netting, and fiber webs), the ability to enhance the polymeric sorbent particles is consistent across all filter holder formats, and for example, in sorption The agent capacity parameters are particularly noticeable.

The scope of the present application is incorporated by reference in its entirety to U.S. Provisional Patent Application Serial No. 62/269, 613, the disclosure of which is incorporated herein by reference. This application contains (in addition to working example 14, its composition and procedures are similar to those of the above working examples), many other working examples in which various monomer ratios are used (eg, divinylbenzene, Maleic anhydride, and styrene type monomers) using various amines (for example, ammonium hydroxide, hydrazine monohydrate, ethylenediamine, and N,N' -dimethylethylenediamine), and under various reaction conditions A polymeric sorbent is produced. Although such work cases are not reproduced in this document for the sake of brevity, those working examples of the '613 application are characterized by polymeric sorbents (such as porosity, surface area, total pore volume, and special It is the adsorption of formaldehyde that will allow those of ordinary skill to anticipate the properties exhibited by the sorbents of such work cases (especially the enhanced ability to adsorb formaldehyde) will similarly exhibit these materials in any manner disclosed herein. Suitable filter holder.

The foregoing examples are provided for the sake of clarity and are not to be construed as limiting. The tests and test results described in the examples are intended to be illustrative rather than predictive, and variations in the test procedure can be expected to yield different results. In view of the well-known tolerances involved in the procedures used, all quantitative values in the examples are to be understood as approximation.

It will be understood by those of ordinary skill in the art that the presently disclosed embodiments may be modified and/or combined in many embodiments. Such changes and combinations are considered to be within the scope of the present invention by the inventors of the present invention, and not only those representative designs selected as illustrative. Therefore, the scope of the invention is not limited to the specific exemplified structures described herein, but extends to the scope of the claims and the equivalents of the structures. Any of the elements that are specifically described in this specification as being a substitute may be explicitly included in the scope of the patent application or excluded from the scope of the patent application in any combination as desired. Any element or combination of elements described in the open language (eg, including its derivatives) in this specification may be considered as a closed language (eg, composition and its derivatives) and a plural closed type. The language (for example: main composition, and its derivatives) is described. Although various theories and possible mechanisms may have been discussed herein, such statements should not be used in any way to limit the claimed subject matter. In the event of any conflict or discrepancy between the disclosure of this specification and any documents incorporated by reference in this specification, the content of this specification shall prevail.

1‧‧‧Air filter

10‧‧‧Filter bracket/filter bracket layer

100‧‧‧ sorbent particles

Claims (30)

An air filter comprising a filter holder supporting polymeric sorbent particles, wherein the polymeric sorbent comprises the following reaction product: (a) a polymeric precursor material comprising a polymerizable composition, The polymerizable composition comprises (1) from 8 to 65 weight percent of maleic anhydride based on the total weight of the monomers in the polymerizable composition; (2) based on the total weight of the monomers in the polymerizable composition, 30 to 85 wt% of divinylbenzene; and (3) from 0 to 40% by weight, based on the total weight of the monomers in the polymerizable composition, of a styrene type monomer, wherein the styrene type single system styrene, An alkyl-substituted styrene, or a combination thereof; and (b) a nitrogen-containing compound selected from the group consisting of ammonia, a compound having a single primary amine group (-NH ₂ ), or having at least two amine groups of the formula -NHR A compound wherein R is hydrogen or an alkyl group, and wherein the polymerizable sorbent is present in the form of porous particles. The air filter of claim 1, wherein the filter holder comprises a substrate having at least one major surface, at least some of the polymeric sorbent particles being disposed on the at least one major surface. The air filter of claim 2, wherein the polymeric sorbent particles are present in a single layer on the major surface of the substrate. The air filter of claim 1, wherein the filter holder comprises a porous gas permeable material having polymerizable sorbent particles disposed on a major surface thereof and/or disposed on the material The interior is at least in the vicinity of one of the major surfaces of the material, the polymeric sorbent particles. The air filter of claim 4, wherein the polymerizable sorbent particles are disposed throughout the interior of the porous gas permeable material. An air filter according to claim 1, wherein the air filter consists essentially of the filter holder. The air filter of claim 1, wherein the filter holder comprises a sheet of material exhibiting a major plane and exhibiting a thickness of less than about 3 mm, and configured to allow the airflow to be at least substantially perpendicular to the The filter holder is passed through one of the major planes of the sheet material. The air filter of claim 1, wherein the filter holder comprises a netting having a major surface to which at least some of the polymeric sorbent particles adhere. The air filter of claim 1 wherein the filter holder comprises a web exhibiting an interior, and wherein the polymeric sorbent particles are disposed within at least a portion of the interior of the web. The air filter of claim 9, wherein the polymeric sorbent particles are disposed throughout the interior of the web. An air filter according to claim 9 wherein the mesh is a nonwoven web. The air filter of claim 11, wherein the nonwoven web is a meltblown web. The air filter of claim 9, wherein at least some of the fibers of the web are each bonded to at least one polymeric sorbent particle. An air filter according to claim 1, wherein the filter holder is a layer of a plurality of gas permeable members. The air filter of claim 14 wherein the multilayer venting component comprises at least one layer different from the filter holder and which exhibits a particle filtration layer of less than 50 percent penetration. The air filter of claim 15 wherein the particle filter layer comprises an electret portion. The air filter of claim 1 wherein the filter holder exhibits a filter medium that is less than 50 percent penetration. An air filter according to claim 1, wherein the filter holder is pleated. The air filter of claim 1, wherein the air filter is a frame air filter configured to be inserted into an air filter receptacle of an air treatment device, the air treatment device being selected from the group consisting of Group: a forced air heating unit, a forced air cooling unit, a forced air heating/cooling unit, an indoor air purifier, and a cabin air filter unit for an electric vehicle. The air filter of claim 1, wherein the filter holder comprises a honeycomb having a through hole, and the sorbent particles are disposed in the honeycomb. The air filter of claim 1, wherein the filter holder provides a layer of a filtered mask respirator. The air filter of claim 21, wherein the filtering facepiece respirator is selected from the group consisting of a flat-fold respirator and a molded respirator. The air filter of claim 1, wherein the filter holder comprises a container having an interior, the polymeric sorbent particles being disposed within the interior and having at least one gas inlet and at least one gas outlet. The air filter of claim 23, wherein the filter holder comprises a filter cartridge. The air filter of claim 24, wherein the filter is configured for use with a personal protective device selected from the group consisting of a half-face negative pressure respirator, a full-pressure negative pressure respirator , escape hood, and powered air purifying respirator. A method of capturing at least some aldehyde from air, the method comprising: positioning an air filter comprising a filter holder, the filter holder comprising the polymeric sorbent particles of claim 1 such that the polymeric absorption The agent particles are exposed to the air, and at least some of the aldehyde present in the air is adsorbed onto the polymeric sorbent particles, wherein the aldehyde has the formula (I) R2-(CO)-H (I) Wherein R ₂ is hydrogen, alkyl, vinyl, or aryl, and wherein the aldehyde having the formula (I) has a molecular weight of not more than 200 g/mol. The method of claim 26, wherein R ₂ is hydrogen or methyl. The method of claim 26, wherein the filter holder exhibits a major surface, and wherein the air is present in the form of a flow of air moving in one direction, the direction being at least substantially flush with one of the major surfaces of the filter holder Face alignment. The method of claim 26, wherein the filter holder allows airflow therethrough, and wherein the air is present in the form of an air flow in a direction at least substantially perpendicular to a major surface of the filter holder Pass through at least a portion of the filter holder. A method of making an air filter comprising a filter holder comprising polymer sorbent particles, the method comprising: (a) providing a polymeric product precursor polymer comprising a polymerizable composition, the The polymeric composition comprises (1) from 8 to 65 weight percent of maleic anhydride based on the total weight of the monomers in the polymerizable composition; (2) from 30 to 85 weight based on the total weight of the monomers in the polymerizable composition a percentage of divinylbenzene; and (3) from 0 to 40 weight percent of the styrene monomer based on the total weight of the monomers in the polymerizable composition, wherein the styrene type single system styrene, alkyl group Substituting styrene, or a combination thereof; and (b) reacting the precursor polymeric material with a nitrogen-containing compound to form the polymeric sorbent, the nitrogen-containing compound being selected from the group consisting of ammonia, having a single primary amine group (- a compound of NH ₂ ), or a compound having at least two amine groups of the formula NNR, wherein R is hydrogen or an alkyl group, wherein the polymeric sorbent has a covalently attached nitrogen-containing group and is in the form of particles And (c) supporting the polymeric sorbent particles On a filter holder.