CN118215559A

CN118215559A - Abrasive backing and method of making same

Info

Publication number: CN118215559A
Application number: CN202280070562.6A
Authority: CN
Inventors: P·J·维弗卡; C·鲁科特; J·托马西; R·拉西拉
Original assignee: Nina Co
Current assignee: Nina Co
Priority date: 2021-10-21
Filing date: 2022-10-20
Publication date: 2024-06-18
Also published as: US20230127264A1; AU2022370042A1; CA3235377A1; WO2023069623A1

Abstract

Generally, an abrasive backing is provided. In some embodiments, the abrasive backing comprises: a substrate comprising wood fibers, synthetic fibers, cellulose filaments, a saturating agent, wherein the saturating agent comprises two or more latex polymers and a cross-linking agent, and the substrate comprises a first surface and an opposing second surface; a barrier coating adjacent the first surface of the substrate; and a back-side coating adjacent to the opposing second surface of the substrate. A method of making an abrasive backing is also provided.

Description

Abrasive backing and method of making same

Technical Field

The present disclosure relates to an abrasive backing having improved strength properties.

Background

When using an abrasive backing for sanding applications, a common problem is that the backing tears after a certain number of sanding cycles. A further common problem is that after a certain number of folds the backing tears and is no longer usable. When the abrasive backing is used with sandpaper on a power plant, a significant amount of internal heat build-up can negatively impact the material removal rate when the plant is in use. In addition, the sandpaper softens or recovers (rejuVenated) in water to flush the sanded material out of the grit, which can cause the sandpaper to lose some of its strength properties from soaking or cleaning.

Accordingly, there is a need for an abrasive backing having improved strength properties. In particular, there is a need for an abrasive backing that allows for an increased number of sanding cycles or folds before the backing tears. There is also a need for an abrasive backing that improves material removal and maintains its strength properties when immersed or cleaned.

Disclosure of Invention

An abrasive backing is generally provided. In some embodiments, the abrasive backing comprises a substrate (including a first surface and an opposing second surface) comprising wood fibers, synthetic fibers, cellulose filaments, a saturating agent (wherein the saturating agent comprises two or more latex polymers and a cross-linking agent), a barrier coating adjacent the first surface of the substrate, and a back coating adjacent the opposing second surface of the substrate. The barrier coating may be impermeable to liquid water and allow for gas transport. In some embodiments, the abrasive backing may have two or more barrier coatings applied adjacent to the first surface of the substrate. The abrasive backing can have grit applied adjacent a surface of the barrier coating opposite the first surface of the substrate. The back-side coating may be water-resistant. In other embodiments, the abrasive backing may have a layer comprising a plurality of loops or a plurality of hooks on a surface of the backcoating opposite the second surface.

In some embodiments, the substrate may comprise wood fibers comprising hardwood fibers, softwood fibers, or a combination thereof. In some embodiments, the substrate may comprise wood fibers in the substrate comprising a blend of softwood fibers and hardwood fibers, for example, a blend of 30 to 70 weight percent softwood fibers and 70 to 30 weight percent hardwood fibers, each based on the weight of the wood fibers and cellulose filaments in the substrate. The substrate may also comprise jute fibers, straw fibers, cotton fibers, hemp fibers, bagasse fibers, bamboo fibers, reed fibers, sisal fibers, abaca fibers, kenaf fibers, flax fibers, or a combination thereof.

In other embodiments, the substrate may have two or more latex polymers in an amount of 55 wt% to 99.9 wt% of the saturating agent, based on the weight of dry solids in the saturating agent. In some embodiments, two of the two or more latex polymers may be crosslinkable. The saturating agent may comprise a third latex polymer. The two or more latex polymers may include copolymers prepared from monomers comprising styrene and butadiene. In some embodiments, the latex polymer is selected from the group consisting of latex polymers having a Tg of-40 ℃ to-20 ℃ and latex polymers having a Tg of-12 ℃ to 8 ℃. The latex polymer may also comprise a latex polymer having a Tg of 32 ℃ to 52 ℃. The latex polymer may comprise 10 to 50 wt% of the latex polymer having a Tg of-40 to-20 ℃,50 to 90 wt% of the latex polymer having a Tg of-12 to 8 ℃, and 10 to 50 wt% of the latex polymer having a Tg of 32 to 52 ℃, based on the total dry weight of the latex polymer. In other embodiments, the saturating agent may comprise the cross-linking agent in an amount of 0.25 wt% to 1.5 wt% of the saturating agent, based on the weight of dry solids in the saturating agent. The crosslinking agent may include an aziridine crosslinking agent, glyoxal type crosslinking agent, ammonium zirconium carbonate, carbodiimide, aliphatic polyglycidyl ether, hexamethoxymethyl melamine, zinc diethyldithiocarbamate, or a combination thereof. For example, the crosslinker may comprise an aziridine crosslinker.

In some embodiments, the substrate may comprise cellulose filaments in an amount of 1 wt% to 5 wt%, based on the weight of the lignocellulosic and cellulose filaments in the substrate. The cellulose filaments may have an aspect ratio of 200 to 5000 and a width of 30nm to 500nm. In addition, the substrate may have 2 to 8 weight percent synthetic fibers based on the weight of the lignocellulosic and cellulosic filaments in the substrate. The synthetic fibers may include polyester fibers such as polyethylene terephthalate (PET) fibers. The abrasive backing may have a basis weight of 75gsm to 155gsm.

Methods for forming abrasive backings are also generally provided. In one embodiment, the method includes providing a substrate comprising wood fibers, synthetic fibers, cellulose filaments, and a saturating agent comprising two or more latex polymers and a cross-linking agent; applying a barrier coating to a first surface of a substrate; and applying a back-side coating to a second surface of the substrate opposite the first surface of the substrate. The method may further include providing a substrate made of wood fibers, synthetic fibers, and cellulose filaments; saturating the substrate with a saturating agent comprising two or more latex polymers and a cross-linking agent; and drying the saturated substrate. The method may further include providing a substrate by forming the substrate from a fibrous matrix comprising wood fibers, synthetic fibers, and cellulosic filaments; and drying the substrate. Then, the substrate is rolled after being saturated with a saturating agent. The method of making an abrasive backing may include other features described above with respect to the abrasive backing.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and claims.

Drawings

This application includes reference to the accompanying drawings, in which:

FIG. 1A illustrates an exemplary abrasive backing; and

FIG. 1B shows an enlarged view of the example abrasive backing of FIG. 1A along line 1B.

Figures 2A and 2B provide data from examples demonstrating the abrasive backings described herein.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

Detailed Description

The present disclosure generally provides an abrasive backing and a method of forming the same. In certain embodiments, the abrasive backing comprises a substrate comprising wood fibers, synthetic fibers, cellulose filaments, and a saturating agent, wherein the saturating agent comprises two or more latex polymers and a cross-linking agent. The substrate includes a first surface and an opposing second surface. Adjacent to the first surface of the substrate is a barrier coating and adjacent to the opposite second surface is a back-side coating.

Referring to fig. 1A, an exemplary abrasive backing 10 is shown formed from a substrate 12 having a first surface 11 and a second surface 13. The barrier coating 22 is adjacent the first surface 11 of the substrate. The back-side coating 20 is adjacent to the second surface 13 of the substrate 12.

Fig. 1B shows an enlarged view of the abrasive backing 10 of fig. 1A. In the illustrated embodiment, the base sheet 12 comprises a plurality of fibers including softwood fibers 14, hardwood fibers 16, and synthetic fibers 24. The substrate 12 also includes cellulose filaments 26. The substrate 12 also includes latex particles 18 provided by two or more polymers in the saturating agent.

Each of the components of the abrasive backing 10 provided herein will be discussed in more detail below with respect to an abrasive backing and a method of forming an abrasive backing.

The substrate 12 comprises a plurality of fibers including wood fibers, synthetic fibers, and cellulose filaments that are bonded together by a polymer matrix formed from the reaction of two or more latex polymers and a cross-linking agent. As discussed herein, the polymer matrix is provided by a saturating agent that saturates the plurality of fibers in the substrate. In some embodiments, hydroxyl groups present in the fibers and cellulose filaments may form hydrogen bonds with pendant groups present in the latex polymer provided in the saturating agent (e.g., when the latex polymer is carboxylated).

The wood fibers in the substrate may comprise softwood fibers 14, hardwood fibers 16, or a blend thereof. In certain embodiments, the wood fibers may comprise a blend of softwood fibers and hardwood fibers. The basesheet may comprise from 5 wt% to 95 wt%, from 10 wt% to 90 wt%, from 20 wt% to 80 wt%, or from 30 wt% to 70 wt% softwood fibers based on the weight of the lignocellulosic and cellulosic filaments in the basesheet. The substrate may comprise 5 to 95 wt%, 10 to 90 wt%, 20 to 80 wt%, or 30 to 70 wt% of the hardwood fibers based on the weight of the lignocellulosic and cellulosic filaments in the substrate.

Examples of softwood fibers include northern bleached softwood kraft pulp (NBSK), examples of which are provided in table 1. In some embodiments, the length weighted average fiber length of the softwood fibers may be from 1.99mm to 2.30mm. Examples of hardwood fibers include Northern Bleached Hardwood Kraft (NBHK), examples of which are provided in table 2, NBHK. In some embodiments, the length weighted average fiber length of the hardwood fibers may be from 0.58mm to 1.11mm. In some embodiments, eucalyptus bleached kraft (EuBK) may also be used in place of NBHK.

In some embodiments, the plurality of fibers may comprise additional fibers. The additional fibers may include jute fibers, straw fibers, cotton fibers, hemp fibers, bagasse fibers, bamboo fibers, reed fibers, sisal fibers, abaca fibers, kenaf fibers, flax fibers, or a combination thereof.

The additional fibers may replace 1 wt% or more, 5wt% or more, 10 wt% or more, 20 wt% or more, 30 wt% or more, or 40 wt% or more, or 50 wt% or less, 40 wt% or less, 30 wt% or less, 20 wt% or less, 10 wt% or less, or 5wt% or less of the wood fibers in the substrate. For example, straw fibers may be used to replace all or part of the hardwood fibers used in the hardwood/softwood fiber blend.

The substrate 12 may comprise cellulose filaments. For example, cellulose filaments may be formed from the breakdown of wood fibers to provide individual filaments. The cellulose filaments may have an aspect ratio of 200 to 5000 and a width of 30nm to 500nm. One exemplary source of cellulose filaments is FILOCELL ^TM CF, which is commercially available from Kruger Biomaterials inc. Cellulose filaments may be provided in the basesheet in an amount of 0.1 wt% to 10 wt%, 0.5 wt% to 7.5 wt%, or 1 wt% to 5 wt% based on the weight of the lignocellulosic and cellulose filaments in the basesheet.

The plurality of fibers may comprise synthetic fibers to provide additional properties to the substrate. For example, synthetic fibers may work in concert with wood fibers to increase tear resistance of the substrate. The synthetic fibers may be formed from any suitable material and have any suitable size and shape, so long as the resulting synthetic fibers are used as high tensile strength fibers. Examples of such synthetic fibers may include polyolefins (e.g., polyethylene, polypropylene, polybutylene, etc.); polytetrafluoroethylene; polyesters (e.g., polyethylene terephthalate); polyvinyl acetate; polyvinyl chloride vinyl acetate; polyvinyl butyral; acrylic resins (e.g., polyacrylate, polymethacrylate, polymethyl methacrylate, etc.); polyamides (e.g., nylon 6/6, nylon 4/6, nylon 11, nylon 12, nylon 6/10, and nylon 12/12); polyvinyl chloride; polyvinylidene chloride; a polystyrene; polyvinyl alcohol; polyurethane; polylactic acid; and combinations thereof. In certain embodiments, the synthetic fibers comprise a polyester, such as polyethylene terephthalate (PET) 24. Synthetic PET fibers include those commercially available from Toray Industries, inc. In some embodiments, the synthetic fibers have a length of 1mm to 10mm or 2mm to 8mm. In some embodiments, the denier of the synthetic fibers may be from 0.5dpf (single fiber denier) to 6.0dpf or from 3.0dpf to 6.0dpf. Synthetic fibers are provided in the basesheet in an amount of 0.5 wt% to 15 wt%, 1 wt% to 12 wt%, 2 wt% to 10 wt%, or 2 wt% to 8 wt%, based on the weight of the lignocellulosic and cellulosic filaments in the basesheet.

Various additives may be applied to the various fibers (e.g., to the dried fibers) during formation of the fiber web or after formation of the base sheet 12. For example, wet strength agents may be used to improve the strength properties of the web during formation. The wet strength agent may be present in an amount of 0.001 to 5 wt% or 0.01 to 2 wt% based on the weight of the lignocellulosic and cellulosic filaments in the substrate. Wet strength agents are typically water-soluble, cationic oligomer or polymer resins capable of binding to cellulosic fibers. For example, some suitable wet strength agents are polyamine-epichlorohydrin, polyamide-epichlorohydrin or polyamide-amine epichlorohydrin resins (collectively "PAE" resins). Other wet strength agents may also be used in certain embodiments. For example, other suitable wet strength agents may include dialdehyde starch, polyethylenimine, mannogalactan, glyoxal resin, polyisocyanate, and dialdehyde mannans. In some embodiments, the wet-strength resin comprises a polyamide epichlorohydrin (PAE) resin.

Various other additives may also be used in the substrate 12. The additive may be provided with the fibers during formation of the substrate or applied to the substrate with a saturating agent. Suitable additives may include defoamers, processing aids, surfactants and dispersants. For example, kaolin pigments may be included in the substrate to increase opacity. Various pigments and dyes may also be added to impart color to the substrate. The pigments and dyes may be added during formation of the substrate, may be provided with the saturating agent when the substrate is saturated, or may be provided as a separate coating onto the substrate after saturation.

As discussed herein, a plurality of fibers are provided in a polymer matrix in the substrate 12. The polymer matrix is provided by a saturating agent or saturating agent composition that is used to saturate the fibers during or after formation of the substrate. In certain embodiments, the saturating agent is provided after the substrate is formed to saturate the substrate. As discussed herein, the polymer matrix is formed by using at least two latex polymers and a cross-linking agent. In certain embodiments, two or more of the at least two latex polymers are crosslinkable, so they can react with the crosslinking agent in the saturating agent or with other latex polymers. The reaction of the latex polymer and the crosslinking agent may occur by heating or by removing water from the saturating agent in the substrate. In addition to physically binding the plurality of fibers in the substrate, the one or more latex polymers and cross-linking agents may also bind with the plurality of fibers or cellulose filaments, for example, by hydrogen bonding.

The saturating agent comprises at least two latex polymers 18, at least three latex polymers, or more. In some embodiments, the saturating agent comprises three latex polymers. In some embodiments, two or more latex polymers can be crosslinked to form a polymer matrix upon reaction with a crosslinking agent. In some embodiments, all three latex polymers are crosslinkable. Suitable latex polymers include styrene-butadiene copolymers (formed primarily by the reaction of styrene and butadiene monomers), styrene-acrylic acid copolymers (formed primarily by the reaction of styrene and (meth) acrylic acid and/or (meth) acrylate monomers), pure acrylic acid copolymers (formed primarily by the reaction of (meth) acrylic acid and/or (meth) acrylate monomers), or mixtures thereof. For example, the neat acrylic copolymer may be a polyacrylate, such as zinc polyacrylate. Other suitable latex polymers include N-methylolacrylamide, ethylene-vinyl acetate copolymers, nitrile rubber, acrylonitrile-butadiene copolymers, poly (vinyl chloride) copolymers, poly (vinyl acetate) copolymers, ethylene-acrylate copolymers, vinyl acetate-acrylate copolymers, neoprene or trans-1, 4-polychloroprene, cis-1, 4-polyisoprene, butadiene rubber, cis-and trans-1, 4-polybutadiene, ethylene-propylene copolymers, or mixtures thereof. In certain embodiments, the latex polymer may be crosslinkable and may include functional groups configured to allow the latex polymer to crosslink with a crosslinking agent, another latex polymer, or both. For example, the latex polymer may comprise crosslinkable groups, such as carboxyl groups, amine groups, pyridinyl groups, or combinations thereof. In some embodiments, the crosslinkable latex polymer can include one or more carboxylated styrene-butadiene copolymers. In some embodiments, the latex polymer particles may have a particle size of 100nm to 300nm or 140nm to 210nm.

In some embodiments, the saturating agent may comprise two or more latex polymers 18in an amount of 55 wt.% to 99.9 wt.% or 70 wt.% to 99.75 wt.%, based on the weight of dry solids in the saturating agent. The at least two latex polymers may comprise a latex polymer having a Tg of-40 ℃ to-20 ℃ and a latex polymer having a Tg of-12 ℃ to 8 ℃. In certain embodiments, the latex polymer may have a Tg of 32 ℃ to 52 ℃. For example, the latex polymer may comprise 10 wt.% to 50 wt.% of the latex polymer having a Tg of-40 ℃ to-20 ℃, 50 wt.% to 90 wt.% of the latex polymer having a Tg of-12 ℃ to 8 ℃, and 0 wt.% (or 10 wt.%) to 50 wt.% of the latex polymer having a Tg of 32 ℃ to 52 ℃, based on the total dry weight of the latex polymer in the saturating agent. Depending on the particle size, gel content, glass transition temperature, and the number of crosslinking groups (e.g., degree of carboxylation), certain properties may be imparted to the substrate 12 by using different polymer latices.

The saturating agent may comprise a cross-linking agent. In certain embodiments, the crosslinking agent may include an aziridine crosslinking agent, glyoxal type crosslinking agent, ammonium zirconium carbonate, carbodiimide, aliphatic polyglycidyl ether, hexamethoxymethyl melamine, zinc diethyldithiocarbamate, or a combination thereof. In certain embodiments, the crosslinker may comprise an aziridine crosslinker. The saturating agent may comprise the cross-linking agent in an amount of 0.1 wt% to 2.5 wt%, 0.2 wt% to 2 wt%, or 0.25 wt% to 1.5 wt% based on the weight of dry solids in the saturating agent. The cross-linking agent having an aziridine skeleton achieves both wet and dry properties by covalently bonding with molecules having carboxylic acid groups, such as carboxylated styrene-butadiene latex, to form a cross-linked network.

Other components may be included in the saturating composition, as desired. For example, an antioxidant compound may be included in the saturating agent composition. Antioxidants help to inhibit oxidation of the saturating composition during the curing process. Oxidation can discolor the saturating agent composition and reduce its final physical properties. Examples of antioxidants include substituted phenolic compounds such as butylated dihydroxyanisole, di-t-butyl-p-cresol, and propyl gallate. Other examples of antioxidants include aromatic amines such as di-beta-naphthylp-phenylenediamine and phenyl-beta-naphthylamine. If used, antioxidants may be included in the formulation at a concentration of less than 10 wt%, less than 5 wt%, less than 2wt%, less than 1 wt%, or less than 0.5 wt%, based on the weight of dry solids in the saturating agent. In a specific embodiment, a phenolic antioxidant may be included in the saturating agent composition.

Additional materials such as fillers, emulsifiers, water repellents and film forming resins may be included in the saturating composition if desired. Suitable fillers may include silica or silicates, clays and borates. The filler may be included in the saturating agent in an amount of greater than 0 wt% to 45 wt% or 5 wt% to 30 wt% based on the weight of dry solids in the saturating agent. Fillers (e.g., clay) may act to reduce moisture and air permeation of the substrate. Examples of suitable clays include the high brightness kaolin No. 1, high brightness ultrafine clay No. 1, high brightness clay No. 2, normal brightness ultrafine clay No. 1, normal brightness clay No. 2, and combinations thereof provided in table 3.

The saturating agent may also contain other additives for providing the saturating agent composition with the desired quality. Examples may include chemicals or surfactants for pH adjustment.

Trisodium phosphate may be included in the saturating agent composition as an emulsifier and/or thickener to help control the pH of the emulsion.

The barrier coating 22 may be applied to the substrate 12 after saturation. The barrier coating 22 may be applied from a composition that may independently comprise any of the materials discussed above with respect to the saturant composition. Suitable latex polymer binders for the barrier coating may include acrylic latex binders. Suitable polyacrylic latex binders may include polymethacrylates, poly (acrylic acid), poly (methacrylic acid), and various acrylates and copolymers of methacrylates with free acids; ethylene acrylate copolymers; and vinyl acetate-acrylate copolymers.

The latex polymer binder used for the saturant and the barrier coating may be the same or different. The latex polymer of the barrier coating is typically selected to adhere or bond well to the surface of the saturated substrate. In addition, the latex polymer binder of the barrier coating may be configured to flow sufficiently well during any subsequent calendering (e.g., soft calendering or super calendering). For example, latex polymer binders having viscosities of 10 centipoise to 100 centipoise can be expected to flow sufficiently well.

The thickness of the barrier coating 22 may vary depending on the intended use of the resulting adhesive backing. For example, thinner barrier coatings may be used in grit abrasive products, such as abrasives having a particle size of 200 mesh or greater (the term "mesh" as used herein refers to U.S. standard screens). On the other hand, thicker barrier coatings may be used for finer grit products to be used for polishing or fine surface finish. The actual minimum layer thickness is 10 microns and the actual maximum layer thickness is 250 microns. However, thinner or thicker layers may be employed if desired, provided that the layers are continuous. Inherently rigid thermoplastic polymer compositions will be more suitable for grit products, while softer or elastic thermoplastic polymer compositions, such as ethylene-vinyl acetate copolymers and polyurethanes, will be more suitable for grit products such as fine sand and polishing cloths.

In another exemplary barrier coating, a tie layer can be on the first surface and a barrier coating can be on the tie layer as disclosed in U.S. patent application serial No. 14/245,342 entitled "ultra-smooth paper backing for fine sand abrasives and methods of use and application thereof," VerVacke filed on 4 months 2014, which is incorporated herein by reference.

In certain embodiments, the barrier coating 22 may be impermeable to liquid water and allow for gas transport. In certain embodiments, the barrier coating 22 allows for the transport of gases and liquids. In some embodiments, the abrasive backing may have two or more barrier coatings applied adjacent to the first surface of the substrate. Exemplary abrasive backings can include make coatings applied adjacent to barrier coatings and grit coatings applied adjacent to make coatings. In some embodiments, the make coating may comprise a liquid phenolic thermoset resin, a hydroxyl-containing polyester, a polyester polyol, an aromatic polyisocyanate, butyl acetate, sorbitol laurate, or a combination thereof. In some embodiments, the make coating comprises a liquid phenolic thermoset resin. The make coat anchors the grit to the substrate 12 of the abrasive backing 10.

The back-side coating 20 may be any suitable layer or coating on the second surface that is not configured to have a layer of abrasive particles thereon. Any such back-coating may be used and tailored for a particular application, as is known in the art. Such a back-coating may be applied from a composition that may independently comprise any of the materials discussed above with respect to the saturating agent. In some embodiments, the back-coating 20 may be waterproof, and in some embodiments, may comprise a coating comprising a plurality of loops or a plurality of hooks (e.g.) Is a layer of (c). The layer comprising the plurality of loops or the plurality of hooks may be discontinuous and provided only where needed to mate with a sanding device having a corresponding plurality of loops (in the case of the back-coating 20 having a plurality of hooks) or a plurality of hooks (in the case of the back-coating having a plurality of loops). The back-side coating 20 may include latex polymers and various other additives. Suitable additives may include defoamers, pigments, processing aids, dispersants and matting agents. In some embodiments, the back-coating 20 may include a filler such as diatomaceous earth. Diatomaceous earth may increase the feel of the back-coating 20 when used in manual sanding applications.

Exemplary abrasive backings 10 may be formed by the following methods: comprising providing a substrate 12 comprising wood fibers, synthetic fibers, and cellulose filaments, and a saturating agent comprising two or more latex polymers and a cross-linking agent; applying a barrier coating 22 to the first surface 11 of the substrate 12; and applying a back-side coating 20 to a second surface 13 of the substrate 12 opposite said first surface 11 of the substrate 12. For certain embodiments of the abrasive backing, providing the substrate 12 may include providing a substrate 12 comprising wood fibers, synthetic fibers, and cellulose filaments; saturating the substrate 12 with a saturating agent comprising two or more latex polymers and a cross-linking agent; and drying the saturated substrate 12. In other embodiments, providing the substrate 12 may include forming the substrate 12 from a fibrous matrix comprising wood fibers, synthetic fibers, and fibrous filaments, and drying the substrate. In some embodiments of the abrasive backing 10, the forming method can include calendaring the substrate 12.

In certain embodiments, the abrasive backing 10 is formed by a process that includes a barrier coating 22 that is impermeable to liquid water and allows for gas transport. The method may also include a barrier coating 22 that allows for the transport of gases and liquids. Two or more barrier coatings 22 may also be applied adjacent the first surface 11 of the substrate 12. The abrasive backing 10 may also be formed by applying grit adjacent to a surface of the barrier coating 22 opposite the first surface 11 of the substrate 12. In some embodiments, the abrasive backing 10 is formed by a process comprising a layer comprising a plurality of loops or a plurality of hooks provided on a surface of the back-side coating 20 opposite the second surface 13.

In certain embodiments, the abrasive backing 10 comprises an abrasive backing base paper having a basis weight of 75gsm to 155gsm, which comprises a-C weight sandpaper.

To form the substrate 12, a plurality of fibers including wood fibers, optional additional fibers, cellulosic filaments, and synthetic fibers are mixed together. The various fibers are typically placed in a conventional papermaking fiber stock preparation mixer or pulper containing water. The fibrous material feedstock is typically maintained under continuous agitation to form a suspension. If desired, the cellulose filaments and/or wood fibers may also be subjected to one or more refining steps to provide various benefits, including improved tensile and porosity properties of the substrate. Refining results in an increase in the amount of intimate contact of the fiber surface and may be performed using means known in the art, such as a disc refiner, a twin disc refiner, a conical refiner (Jordan refiner), a large taper refiner (CLAFLIN REFINER), or a Valley type refiner.

The resulting fiber suspension may then be diluted and ready to be formed into a fiber web using conventional papermaking techniques. For example, the web may be formed by distributing the suspension onto a forming surface (e.g., filaments) and then removing water from the distributed suspension to form the web. The process may include transferring the suspension to a discharge tank, a pulping tank, a cleaning storage tank, a low density cleaner, a headbox, etc., as is known in the art. After formation, the fibrous web may be dried using any known technique, such as by using convection ovens, radiant heat, infrared radiation, forced air ovens, and heated rolls or cans to produce a substrate. Drying may also include centralized steam drying followed by contact drying. Drying may also be carried out by air drying without the addition of thermal energy.

In some embodiments, the components of the saturating agent are provided as stirrer additives, so they are present in the fiber suspension used to produce the substrate. In some embodiments, a saturating agent may be used to saturate the already formed substrate. Any known saturation technique may be used, such as brushing, dip-coating saturation, doctor blade coating, spraying, and direct and offset gravure coating. For example, the plurality of fibers may be exposed to an excess of the solution and then extruded. Extrusion of excess saturating agent from the plurality of fibers may be accomplished by passing the plurality of fibers between rollers. Excess saturating agent may be returned to the supply for further use if desired. After extruding the excess material, the saturated plurality of fibers may then be dried. Other suitable techniques for saturating multiple fibers with saturating agents are described in U.S. patent No. 5,595,828 to Weber and U.S. patent application publication No. 2002/0168508 to Reed et al, which are incorporated herein by reference in their entirety for all purposes.

The amount of saturating agent applied may vary depending on the desired properties of the various fibers, such as the desired permeability. The saturating agent is typically present at an add-on level of 10 wt% to 40 wt%, in some embodiments, 10 wt% to 25 wt% of the "portion of the belt" or PPU. The PPU addition level was calculated by dividing the dry weight of the applied saturating agent by the dry weight of the various fibers prior to treatment and multiplying the result by 100. The PPU can be calculated by the formula:

Where BW _{Fiber + Saturating agent} and BW _Fiber are all dry (moisture free) measurements of the basis weight of the substrate, BW _Fiber is a measurement of the pre-size press stage, and BW _{Fiber + Saturating agent} is a measurement after size press when the sheet is saturated.

In one embodiment, the saturated substrate 12 is calendered after saturation. Calendering a saturated substrate can increase the softness and smoothness of the sheet. The saturated substrate 12 may be calendered according to any process, when desired. Calendering typically involves pressing a saturated substrate in a nip formed by first and second calender rolls. The effect of calendaring on a saturated substrate depends on the temperature, the pressure applied and the duration of the pressure. For purposes herein, calendering may be performed at ambient or elevated temperatures. Suitable calendering pressures may be 50 to 2000 pounds per linear inch (pli), 100 to 1600pli, 300 to 1000pli, or 400 to 600pli. Suitable temperatures may be 20 ℃ to 240 ℃,20 ℃ to 140 ℃, or 20 ℃ to 90 ℃.

The duration of calendering can be varied along with the nip pressure and/or the composition of the calender rolls to produce the desired smoothness of the paper backing of the sheet. For example, softer calender rolls (such as fiber-filled rolls) tend to compress to form a larger contact area in the nip, thereby increasing the duration of calendering. The hard steel rolls compress more, thereby shortening the duration of the calendering. In one arrangement, the calender nip includes a steel roll and a soft fiber fill roll. In another arrangement, for example, the production of the supercalender may comprise more than two rolls stacked on top of each other in a vertical arrangement, desirably nine to eleven rolls. Desirably, the stack rolls alternate between steel rolls and fiber filled rolls. With such an arrangement, the paper may be exposed to various pressures, up to 1600pli, and multiple nips, e.g., one to eight, to form the desired level of smoothness.

The saturated, calendered substrate 12 may be dried to remove the solvent from the saturating agent composition. For example, the saturated substrate 12 may be heated to a temperature of at least 100 ℃, in some embodiments, at least 150 ℃, such as at least 200 ℃. Suitable drying techniques may include heating with a conventional oven, microwave oven, forced air, heated rollers, cans, or by air drying. Drying may also include centralized steam drying followed by contact drying.

In addition, the saturated, calendered substrate 12 may be cured such that the latex polymer of the saturant composition reacts with the crosslinking agent to crosslink and form a three-dimensional polymer structure. Thus, the crosslinked latex polymer may help to mechanically and/or chemically bind the fibers of the substrate together.

Regardless of the particular processing step of the substrate, the substrate 12 is maintained at a temperature below the softening or melting point of the synthetic fibers so that the synthetic fibers maintain their shape and physical configuration as laid down in the final ply sheet orientation (and the resulting abrasive backing laminate). Thus, the structural and physical integrity of the synthetic fibers remains intact in the individual ply sheets to allow the synthetic fibers to provide strength properties to the ply sheets.

A back-side coating 20 and a barrier coating 22 may be applied to the substrate 12. The back-side coating 20 may be tailored to provide specific properties. In particular, the back-side coating 20 may be printed on, may have a hand sanded feel, or may be pre-coated for a pressure sensitive adhesive.

The abrasive backing 10 also exhibits 100% to 200% improvement in wet properties, which allows sandpaper products made from the abrasive backing 10 to retain strength properties while being soaked or cleaned to flush sanded material out of the grit. While not wishing to be bound by a particular theory, it is believed that these improvements are due to the use of a combination of two or more latex polymers, cross-linking agents, wood fibers, cellulose filaments, and synthetic fibers. The latex polymer provides reinforcement to the fibers, thereby improving the strength properties and durability of the abrasive backing 10. The improvement in wet sandability is also due to the barrier coating and the back coating, which reduce permeability because the use of saturating agents increases the tightness of the sheet.

The abrasive backing 10 can withstand demanding uses in both manual sanding and power tool applications, both wet and dry sanding applications. The strength improvement of the abrasive backing 10 is manifested in both in-plane and out-of-plane strength properties. This is evidenced by a Root Mean Square (RMS) tensile index greater than 95Nm/g (e.g., 95Nm/g to 100 Nm/g). The out-of-plane delamination force is 150 grams force to 1000 grams force or 450 grams force to 750 grams force. It is believed that the cellulose filaments and synthetic fibers provide additional tear strength by entanglement and bonding with the wood fibers.

The abrasive backing 10 has a high delamination force in the wet state after a1 hour or 24 hour soak cycle, which allows the abrasive backing to better retain its strength properties after soaking or cleaning. Wet sanding life is improved because the abrasive backing 10 retains strength properties when periodically cleaned in a suitable polar cleaning solvent (e.g., water). After one hour of soaking in water, the improved backing retains 40% to 60% of dry tensile strength. The improved backing does not require any increase in the substrate refining energy, thus allowing the same level of refining as the densification and strength properties of the backing to be improved.

Sandpaper using the improved abrasive backing 10 is more durable in both manual and power sanding applications. When used in a power plant, the improved sandpaper will reduce internal heat build-up, thereby improving energy transfer from the power plant to the material. Thus, when the same grit and make coat are applied to the abrasive backing, the material removal rate will also increase.

The abrasive backings will now be further described by way of the following non-limiting examples. Parts and percentages are by weight unless otherwise indicated.

Test method

Sample conditioning

Prior to any of the following test methods, the samples were conditioned using TAPPI T402 sp-13 with an additional step of passing conditioned air through the samples for at least 20 minutes.

Basis weight

The basis weight was measured using TAPPI T410, however, the samples were four, with a total area of 412.3in ² instead of the smallest 800in ².

Thickness of (L)

Thickness was measured using TAPPI T411 om-15.

Tensile Strength, tensile Energy Absorption (TEA),% tensile and RMS tensile index

Tensile strength, TEA and% stretch were measured using TAPPI T494-om-01. RMS tensile is the square root of MD tensile plus CD tensile.

MD aged wet tensile strength and MD aged wet stretch

MD aged wet tensile strength and MD aged wet stretch were measured using TAPPI T456 om-15, however, the samples were aged at 145°f for 5 minutes prior to measurement.

Tearing off

Tear was measured using TAPPI T414 om-21, however, the result was a tear of sixteen layers in grams force instead of one layer.

Gurley porosity

Gurley porosity was measured using TAPPI T460 using one or four sheets.

Yarn smoothness

Thread smoothness was measured using TAPPI T538 om-16.

Layering

The delamination was measured using the following procedure:

The Twing-Albert Vantage NX EJA series of testers are suitably calibrated testers, which can be operated in a displacement control mode, with a constant displacement rate of 30.5cm/min. The testing machine was equipped with two opposing clamps for securing the ends of the heat seal tape bonded to the abrasive backing sample. The test vehicle load sender is capable of indicating the total load carried by the test sample, in this case using a 500N load cell. The device has substantially no inertial hysteresis at a prescribed test rate and indicates load with an accuracy within + -1% of the indicated value over a target load range. The data is stored digitally and post-processed. At least five samples were tested under each test condition. The accuracy of all measurement devices goes through the latest authentication calibration when the devices are used. The samples were stored and tested in a standard laboratory environment at 23.+ -. 3 ℃ and 50.+ -. 10% relative humidity.

1. The width of each abrasive backing sample and heat seal belt was 15mm.

2. The delamination force was measured along the center plane of the sample by applying the heat seal tape at a pressure of 45.5gm/cm ² for 20 seconds, laminating the cloth heat seal tape to both sides of the abrasive backing at a temperature of 312 °f ± 12°f, and used to bond the opposite sides of the abrasive backing sample.

3. After heat sealing the abrasive backing sample and prior to loading it into the clamp block, delamination was initiated by manually pulling the two heat seal strips apart from each other at 180 ° until a pre-layering of at least 2.54 cm.

4. The ends of the heat seal tape on the pre-stratified sample are mounted in the clamps of the loader, ensuring that the sample is aligned and centered.

5. The sample was loaded at a constant crosshead speed of 30.5 cm/min.

6. The load and displacement values are recorded continuously.

7. The test load stopped after a test distance of 5.08 em.

8. The sample was unloaded at a constant crosshead speed of 30.5 cm/min.

9. After sample unloading, the average force (grams) over the 5.08em test distance was calculated.

1 Hour wet delamination

The equipment, test methods and instrument parameters are exactly the same as the layering method described above, but with the addition of a soaking step. The samples were immersed in 10g/l of a non-ionic surfactant (C ₁₄H₂₂O(C₂H₄O)_n) impregnating solution for 1 hour prior to testing.

1. The sample was blotted with a paper towel to remove excess moisture.

2. The sample soaked for 1 hour is subjected to a pre-layering step and a loading step specified in the layering method.

3. After the test was completed, the average delamination force of the sample immersed for 1 hour over a test distance of 50.8cm was calculated as performed in the delamination method.

4. The wet delamination force in grams is reported for 1 hour and the wet/dry test ratio in percent is reported for 1 hour.

24 Hour wet layering

The 24-hour wet stratification was measured using the same test as the 1-hour wet stratification, but the samples were immersed in the impregnating solution for 24 hours instead of 1 hour.

Sheffield porosity

Sheffield porosity was measured using TAPPI T547 om-18.

Felt smoothness

Felt smoothness was measured using TAPPI T538 om-16.

Felt gloss

The Felt gloss was measured using TAPPI T480 om-15.

Turpentine penetration

Turpentine penetration was measured using the following test:

1. Xylene and heptane were mixed in a 3:1 volume ratio and 0.25g of sudan red IV was added per 400ml of total xylene/heptane to produce the solvent.

2. The solvent was brushed on the barrier coated side of the sample with a2 "wide paint brush.

3. The sample was left to stand for 10 seconds while the solvent was applied, and then wiped clean.

4. The permeation level was evaluated on a scale of 1,3, or 4, where 1 indicates that the amount of permeation was minimal and 4 indicates that the solvent permeated to the side opposite the barrier coating.

Density of

The density was calculated by using the basis weight measured as above and the thickness measured as above.

Examples

Example 1

Eight different coated saturated substrate samples were prepared and then the properties between the samples were compared. The same process was performed for each prepared sample, but the materials used for the substrate and saturating agent were changed. A sample of the coated saturated substrate was prepared according to the following method:

The unsaturated substrates having the composition according to table 4 were refined for 15 minutes.

TABLE 4 Table 4

The dried sheet was saturated with a saturating agent according to the composition of table 5 to the appropriate liquid.

TABLE 5

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The composition according to table 6 was used to provide a barrier coating and a back-side coating on opposite sides of the substrate.

TABLE 6

The properties of the different abrasive backings are provided in fig. 2A and 2B.

As shown in fig. 2A and 2B, performance was improved when the control samples a_b30 and a_b35 were compared to the abrasive backings provided herein. For example, the Root Mean Square (RMS) tensile index increases from about 80Nm/g for A_B30 to a range of up to 95Nm/g to 100Nm/g as shown for samples B_P30 and B_P35. This indicates that the abrasive backing can withstand demanding uses in both manual sanding and power tool applications, in wet and dry sanding applications. For saturated sandpaper products, there is also 15% to 30% improvement in strength properties (e.g., in-plane tensile strength and tear) and 100% improvement in out-of-plane properties (e.g., z-direction tensile and out-of-plane delamination forces).

The abrasive backing allows for an increase in the number of sanding cycles prior to tensile or tear failure of the abrasive backing. This improvement is demonstrated by the increase in Tensile Energy Absorption (TEA) from 219.8J/m ² for sample A_B30 to 311.9J/m ² for sample B_P35, as provided in FIG. 2A. This improvement was also demonstrated by an average fold endurance of 4,194 fold cycles for conditioned and unaged b_35p, and an average fold endurance of 6,513 fold cycles for conditioned b_35P aged at 120 ℃ for 30 minutes, as provided in table 7.

TABLE 7

Example 2

The properties of sample b_p35 were tested on a commercial paper machine 3.15 meters wide. This embodiment of the abrasive backing employs a substrate having a composition according to substrate B in table 4 and a saturating agent having a composition according to saturating formulation P in table 5. The components of the substrates according to table 4 were supplied to the paper machine stock transfer system, formed on a fourdrinier table, wet pressed, dried and saturated with a saturating agent according to table 5 at a PPU of 28. The barrier coating was applied commercially on a 3.15 meter paper machine and had a composition according to table 6. The back-side coating was applied offline to sample b_p35_bc and had a composition according to table 6.

The experimentally derived property measurements are provided in table 8. The property improvement is based on the current corresponding commercial control level.

TABLE 8

Abrasive backing samples and corresponding compositions are provided in Table 9Performance Materials and Monadnock PAPER MILLS, inc. Corresponding abrasive backings are manufactured on a commercial scale, and the data provided are published and publicly available.

TABLE 9

Sample b_p35 was combined with sample b_p35 as shown in table 9Performance Materials and Monadnock PAPER MILLS, inc. For example, the RMS tensile index increases from 63.8Nm/g for the product in Table 9 Monadnock PAPER MILLS, inc. to 106.1Nm/g for B_P35. The difference in RMS tensile index between b_p35_bc in table 8 and b_p35 in table 9 is due to the back coating applied to b_p35_bc, increasing its basis weight from the basis weight of b_p35 of 108.7gsm to 115gsm.

The compositions and methods of the appended claims are not limited in scope by the specific compositions and methods described herein, which are intended to illustrate several aspects of the claims, and any compositions and methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications to the compositions and methods, other than those shown and described herein, are intended to fall within the scope of the appended claims. Furthermore, while only certain representative compositions and method steps disclosed herein are specifically described, other combinations of compositions and method steps are also intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components or moieties may be explicitly mentioned or less mentioned herein, however, other combinations of steps, elements, components and moieties are included even if not explicitly stated. The term "comprising" and variants thereof as used herein is synonymous with the term "including" and variants thereof, and is an open, non-limiting term. While the terms "comprising" and "including" have been used herein to describe various embodiments, the terms "consisting essentially of" and "consisting of" may be used in place of "comprising" or "including" to provide more specific embodiments of the invention and are also disclosed. Except in the examples, or where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being at least, and are not intended to limit the application of the doctrine of equivalents to the scope of the claims, to be construed in light of the number of significant digits and by ordinary rounding techniques.

Claims

1. An abrasive backing, the abrasive backing comprising:

A substrate comprising wood fibers, synthetic fibers, cellulose filaments, and a saturating agent comprising two or more latex polymers and a cross-linking agent, the substrate comprising a first surface and an opposing second surface;

a barrier coating adjacent to the first surface of the substrate; and

A back side coating adjacent to an opposing second surface of the substrate.

2. The abrasive backing of any one of the preceding claims, wherein the barrier coating is impermeable to liquid water and allows for gas transport.

3. The abrasive backing of any one of the preceding claims, wherein two or more barrier coatings are applied adjacent to a first surface of the substrate.

4. The abrasive backing of any one of the preceding claims, wherein grit is applied adjacent a surface of the barrier coating opposite the first surface of the substrate.

5. The abrasive backing of any one of the preceding claims, wherein the backcoating is water-resistant.

6. The abrasive backing of any one of the preceding claims, wherein a layer comprising a plurality of loops or a plurality of hooks is provided on a surface of the backcoating opposite the second surface.

7. The abrasive backing of any one of the preceding claims, wherein the wood fibers comprise hardwood fibers.

8. The abrasive backing of any one of the preceding claims, wherein the wood fibers comprise softwood fibers.

9. The abrasive backing of any one of the preceding claims, wherein the wood fibers in the base sheet comprise a blend of softwood fibers and hardwood fibers, wherein the blend comprises 30 to 70 weight percent softwood fibers and 70 to 30 weight percent hardwood fibers, each fiber based on the weight of wood fibers and cellulose filaments in the base sheet.

10. The abrasive backing of any one of the preceding claims, wherein the substrate further comprises jute fibers, straw fibers, cotton fibers, hemp fibers, bagasse fibers, bamboo fibers, reed fibers, sisal fibers, abaca fibers, kenaf fibers, flax fibers, or a combination thereof.

11. The abrasive backing of any one of the preceding claims, wherein two or more latex polymers comprise from 55 wt% to 99.9 wt% of the dry solids weight in the saturating agent.

12. The abrasive backing of any one of the preceding claims, wherein at least two of the two or more latex polymers are crosslinkable.

13. The abrasive backing of any one of the preceding claims, wherein the saturating agent further comprises a third latex polymer.

14. The abrasive backing of any one of the preceding claims, wherein the latex polymer is a copolymer prepared from monomers comprising styrene and butadiene.

15. The abrasive backing of any one of the preceding claims, wherein the latex polymer is selected from the group consisting of latex polymers having a Tg of-40 ℃ to-20 ℃ and latex polymers having a Tg of-12 ℃ to 8 ℃.

16. The abrasive backing of claim 15, wherein the latex polymer further comprises a latex polymer having a Tg of 32 ℃ to 52 ℃.

17. The abrasive backing of claim 15 or 16, wherein the latex polymer comprises 10 wt.% to 50 wt.% of the latex polymer having a Tg of-40 ℃ to-20 ℃, 50 wt.% to 90 wt.% of the latex polymer having a Tg of-12 ℃ to 8 ℃, and 10 wt.% to 50 wt.% of the latex polymer having a Tg of 32 ℃ to 52 ℃, based on the total dry weight of the latex polymer.

18. The abrasive backing of any one of the preceding claims, wherein the crosslinker comprises from 0.25 wt.% to 1.5 wt.% of the saturating agent, based on the weight of dry solids in the saturating agent.

19. The abrasive backing of any one of the preceding claims, wherein the crosslinker comprises an aziridine crosslinker, a glyoxal-based crosslinker, zirconium ammonium carbonate, carbodiimide, aliphatic polyglycidyl ether, hexamethoxymethyl melamine, zinc diethyldithiocarbamate, or a combination thereof.

20. The abrasive backing of any one of the preceding claims, wherein the crosslinker comprises an aziridine crosslinker.

21. The abrasive backing of any one of the preceding claims, wherein the cellulose filaments comprise from 1 wt% to 5 wt% based on the weight of wood fibers and cellulose filaments in the substrate.

22. The abrasive backing of any one of the preceding claims, wherein the cellulose filaments have an aspect ratio of 200 to 5000 and a width of 30nm to 500nm.

23. The abrasive backing of any one of the preceding claims, wherein the synthetic fibers comprise 2 to 8 wt% based on the weight of wood fibers and cellulosic filaments in the substrate.

24. The abrasive backing of any one of the preceding claims, wherein the synthetic fibers comprise polyester fibers.

25. The abrasive backing of claim 24, wherein the synthetic fibers comprise polyethylene terephthalate (PET).

26. The abrasive backing of any one of the preceding claims, having a basis weight of 75gsm to 155gsm.

27. A method of making an abrasive backing, the method comprising:

Providing a substrate comprising wood fibers, synthetic fibers, and cellulose filaments, and a saturating agent comprising two or more latex polymers and a crosslinking agent;

applying a barrier coating to a first surface of the substrate; and

A back-side coating is applied to a second surface of the substrate opposite the first surface of the substrate.

28. The method of claim 27, wherein providing a substrate further comprises:

providing a substrate comprising wood fibers, synthetic fibers, and cellulose filaments;

Saturating the substrate with a saturating agent comprising two or more latex polymers and a cross-linking agent; and

The saturated substrate is dried.

29. The method of claim 28, wherein providing a substrate further comprises:

Forming a substrate from a fibrous matrix comprising wood fibers, synthetic fibers, and cellulosic filaments; and drying the substrate.

30. The method of making an abrasive backing of claim 28 or 29, further comprising calendaring the substrate after saturating the substrate with a saturating agent.

31. The method of making an abrasive backing according to any one of claims 27 to 30, wherein the barrier coating is impermeable to liquid water and allows for gas transport.

32. The method of making an abrasive backing according to any one of claims 27 to 31, wherein two or more barrier coatings are applied adjacent to the first surface of the substrate.

33. The method of making an abrasive backing of any one of claims 27 to 32, wherein grit is applied adjacent a surface of the barrier coating opposite the first surface of the substrate.

34. The method of making an abrasive backing according to any one of claims 27 to 33, wherein the back-side coating is water-resistant.

35. The method of making an abrasive backing according to any one of claims 27 to 34, wherein a layer comprising a plurality of loops or a plurality of hooks is applied to a surface of the back-side coating opposite the second surface.

36. The method of making an abrasive backing according to any one of claims 27 to 35, wherein the wood fibers comprise hardwood fibers.

37. The method of making an abrasive backing according to any one of claims 27 to 36, wherein the wood fibers comprise softwood fibers.

38. The method of making an abrasive backing according to any one of claims 27 to 37, wherein the wood fibers in the base sheet comprise a blend of softwood fibers and hardwood fibers, wherein the blend comprises 30 to 70 weight percent softwood fibers and 70 to 30 weight percent hardwood fibers, each based on the weight of wood fibers and cellulose filaments in the base sheet.

39. The method of making an abrasive backing according to any one of claims 27 to 38, wherein the substrate further comprises jute fibers, straw fibers, cotton fibers, hemp fibers, bagasse fibers, bamboo fibers, reed fibers, sisal fibers, abaca fibers, kenaf fibers, flax fibers, or a combination thereof.

40. The method of making an abrasive backing according to any one of claims 27 to 39, wherein the two or more latex polymers comprise 55 wt.% to 99.9 wt.% of the saturating agent, based on the weight of dry solids in the saturating agent.

41. The method of making an abrasive backing according to any one of claims 27 to 40, wherein at least two of the two or more latex polymers are crosslinkable.

42. The method of making an abrasive backing according to any one of claims 27 to 41, wherein the saturating agent further comprises a third latex polymer.

43. The method of making an abrasive backing according to any one of claims 27 to 42, wherein the latex polymer is a copolymer prepared from monomers comprising styrene and butadiene.

44. The method of making an abrasive backing according to any one of claims 27 to 43, wherein the latex polymer is selected from the group consisting of latex polymers having a Tg of-40 ℃ to-20 ℃ and latex polymerizations having a Tg of-12 ℃ to 8 ℃.

45. The method of making an abrasive backing according to any one of claims 27 to 44, wherein the latex polymer further comprises a latex polymer having a Tg of 32 ℃ to 52 ℃.

46. The method of making an abrasive backing according to claim 44 or 45, wherein the latex polymer comprises 10 to 50wt% of the latex polymer having a Tg of-40 ℃ to-20 ℃,50 to 90wt% of the latex polymer having a Tg of-12 ℃ to 8 ℃, and 10 to 50wt% of the latex polymer having a Tg of 32 ℃ to 52 ℃, based on the total dry weight of the latex polymer.

47. The method of making an abrasive backing according to any one of claims 27 to 46, wherein the cross-linking agent comprises from 0.25 wt% to 1.5 wt% of the saturating agent, based on the weight of dry solids in the saturating agent.

48. The method of making an abrasive backing according to any one of claims 27 to 47, wherein the crosslinker comprises an aziridine crosslinker, a glyoxal-type crosslinker, ammonium zirconium carbonate, a carbodiimide, an aliphatic polyglycidyl ether, hexamethoxymethyl melamine, zinc diethyldithiocarbamate, or a combination thereof.

49. The method of making an abrasive backing according to any one of claims 27 to 48, wherein the crosslinker comprises an aziridine crosslinker.

50. The method of making an abrasive backing according to any one of claims 27 to 49, wherein the cellulose filaments comprise 1 to 5 wt% based on the weight of wood fibers and cellulose filaments in the base sheet.

51. The method of making an abrasive backing according to any one of claims 27 to 50, wherein the cellulose filaments have an aspect ratio of 200 to 5000 and a width of 30nm to 500nm.

52. The method of making an abrasive backing according to any one of claims 27 to 51, wherein the synthetic fibers comprise 2 to 8wt% based on the weight of wood fibers and cellulose filaments in the base sheet.

53. The method of making an abrasive backing according to any one of claims 27 to 52, wherein the synthetic fibers comprise polyester fibers.

54. The method of making an abrasive backing according to any one of claims 27 to 53, wherein the synthetic fibers comprise polyethylene terephthalate (PET).

55. The method of making an abrasive backing according to any one of claims 27 to 54, wherein the abrasive backing has a basis weight of 75gsm to 155gsm.