RU2374062C2 - Method of structured abrasive product formation - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention relates to abrasive machining and can be used in structured abrasive products manufacturing. The product padding is covered by binding material composition. Partial hardening of the binding material composition and forming of a pattern in the partially hardened binding material composition follow.

EFFECT: treatment efficiency is increased due to providing for the intense allowance removal with simultaneous keeping of high quality of the surface being treated.

15 cl, 2 dwg, 5 ex, 5 tbl

Description

Technical field

The present invention generally relates to the creation of methods and systems for forming structured abrasive products.

BACKGROUND OF THE INVENTION

Abrasive products, such as flexible abrasive tools (abrasives deposited on a substrate) and bonded abrasives (bonded abrasives), are used in various industries for various machining of workpieces, such as grinding, grinding or polishing. Machining using abrasive products has received wide industrial distribution from the optical industry, repair and painting in the automotive industry to metal production. In each of these examples, production equipment with abrasives is used to remove a layer of the workpiece material or change the surface characteristics of the products.

Surface characteristics include gloss, texture and uniformity. For example, manufacturers of metal components use abrasive products to clean and polish surfaces, and often wish to obtain a uniformly (uniformly) smooth surface. Similarly, manufacturers of optical components use abrasive products to produce defect-free surfaces to prevent diffraction and light scattering.

Manufacturers also wish to have abrasive products that provide high stock removal rates in some applications. However, it is often necessary to find a compromise between the intensity of stock removal and surface quality. Fine grain abrasive products (fine-grained abrasive products) usually produce smoother surfaces, but they provide lower stock removal rates. Lower stock removal rates result in lower productivity and higher production costs.

Manufacturers of abrasive products, especially flexible abrasive tools, use surface structures to improve the rate of stock removal while maintaining high surface quality. Flexible abrasive tools having surface structures or a pattern in the form of protruding abrasive layers, which are often referred to as designed or structured abrasives, typically have enhanced service life.

However, typical techniques for forming structured abrasive products are unreliable and suffer from quality limitations. A typical process for forming a structured abrasive product involves coating the substrate with a viscous binder, coating the viscous binder with a functional powder, and embossing or knurling structural patterns in a viscous binder. Functional powder does not allow adhesive to adhere to drawing tools. After carrying out these operations, the binder is cured.

Defects in the coating of viscous binder with functional powder lead to adhesion of the binder to the drawing tools. Adhesion of the binder leads to poor structures, which leads to a deterioration in product performance and loss of product.

The choice of binders suitable for typical structured abrasive forming techniques is limited by the process. Typical binders contain a large load (have a high content) of traditional fillers, which increases the viscosity of the binder. Such conventional fillers act on the mechanical properties of the binder. For example, a large load of traditional fillers can adversely affect such characteristics of the binder material as tensile strength, Young's modulus and elongation at break. Poor mechanical characteristics of the binder, allowing the loss of abrasive grains, lead to scratches and dullness on the surfaces and reduce the service life of the abrasive product.

Loss of grains also affects the performance of abrasive products, which increases the frequency of product replacement. Frequent replacement of an abrasive product is expensive for manufacturers. Thus, it is desirable to have improved abrasive products and methods for manufacturing abrasive products.

SUMMARY OF THE INVENTION

A method for forming a structured abrasive product is provided, which comprises coating the substrate with a binder composition, partially curing the binder composition and forming (forming) a pattern in the partially cured binder composition.

In accordance with another embodiment, a method for forming a structured abrasive article is provided, which comprises coating the substrate with an abrasive slurry that contains a binder and abrasive grains, partially curing the abrasive slurry, and patterning in a partially cured abrasive slurry.

In accordance with another embodiment, a method for forming a structured abrasive product is provided, which comprises partially curing the binder composition to a viscosity index of at least about 1.1, patterning the structures in a partially cured binder composition, and further curing the partially cured binder composition.

The foregoing and other features of the invention will be more apparent from the following detailed description, given by way of example, not of a restrictive nature and given with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 shows an exemplary abrasive product.

Figure 2 shows an exemplary device for manufacturing a structured abrasive product.

DETAILED DESCRIPTION OF THE INVENTION

A method is provided for forming an abrasive article, such as a structured abrasive article, which comprises coating a substrate with a binder composition, partially curing the binder composition, and forming a pattern in the partially cured binder composition. The binder composition may be incorporated into an abrasive slurry that contains a binder composition and abrasive grains. The suspension may be applied to the coating. According to an exemplary embodiment, the binder composition is partially cured to a viscosity index of at least about 1.1. The method may further include fully curing the drawing (curly) and partially cured binder composition. In an exemplary embodiment, the composition of the binder material is a nanocomposite composition of the binder material.

Designed or structured abrasives typically contain a pattern of abrasive structures located on a substrate or support. Exemplary structured abrasives are disclosed in US Pat. 6,293,980. An exemplary embodiment of a designed or structured abrasive is shown in FIG. The structured abrasive has a substrate 102 and a layer 104 containing abrasive grains. Typically, the layer 104 is shaped to form surface structures 106.

The substrate 102 may be flexible or rigid. The substrate 102 can be made of any number of different materials, including those that are usually used as substrates in the manufacture of abrasive flexible tools. An exemplary flexible substrate comprises a polymer film (eg, a print film), such as a polyolefin film (eg, polypropylene, including biaxially oriented polypropylene), a polyester film (eg, polyethylene terephthalate), a polyamide film, or a cellulose ether film; metal foil; a grid; foamed material (e.g., natural porous material or foam urethane); fabric (for example, fabric made from fibers or yarn containing polyester, nylon, silk, cotton, poly-cotton or man-made fiber); paper; vulcanized paper; vulcanizate; fiber, nonwoven fabric; or combinations thereof; or their processed options. The fabric backing may be woven or stitched together. In accordance with specific examples, the substrate is selected from the group consisting of paper, polymer film, fabric, cotton, poly-cotton, artificial fiber, polyester, poly-nylon, vulcanizate, fiber, metal foil, and combinations thereof. According to other examples, the substrate comprises a polypropylene film or a polyethylene terephthalate (PET) film.

The substrate 102 may optionally have at least one layer selected from the group consisting of a saturated layer, a front dimension layer or a rear dimension layer. These layers typically serve to seal the substrate 102 or to protect the yarn or fibers in the substrate 102. If the substrate 102 is made of woven material, at least one of these layers is typically used. Adding a front dimension layer or a back dimension layer further provides a smoother surface on the front or back side of the substrate. If necessary, other known layers can also be used (for example, a screed layer; see, for example, US Pat. No. 5,700,302).

Antistatic material may be included in the fabric processing means for the substrate. The addition of an antistatic material reduces the tendency for an abrasive flexible tool to accumulate static electricity when processing wood and other similar materials. Additional information regarding antistatic substrates and their processing can be found, for example, in US patents Nos. 5,108,463; 5,137,542; 5,328,716; and 5,560,753.

The substrate 102 may be made of fiber reinforced thermoplastic, as described, for example, in US patent No. 5,417,726; or may be in the form of an endless spliced belt, as described, for example, in US Pat. 5,573,619. Similarly, the substrate 102 can be made in the form of a polymer base having protruding hooks from it, as described, for example, in US Pat. 5,505,747. Similarly, the substrate 102 can be made in the form of a loop of fabric, as described, for example, in US patent No. 5,565,011.

In accordance with some other examples, a pressure sensitive adhesive is introduced into the rear side of the abrasive flexible tool, so that the resulting abrasive flexible tool can be attached to the pad. An exemplary pressure-sensitive adhesive contains rubber latex, rosin, acrylic polymer or copolymer, including polyacrylate ether (e.g. poly (butyl acrylate)), vinyl ether (e.g. poly (vinyl n-butyl ether)), alkyd adhesive, rubber adhesive (e.g. natural rubber and chlorinated rubber) or mixtures thereof.

An exemplary rigid substrate comprises a metal plate, ceramic plate, or other similar element. Another example of a suitable rigid substrate is described, for example, in US Pat. 5,417,726.

Layer 104 may be formed as one or more coating layers. For example, layer 104 may comprise a structural coating and possibly a dimensional coating. Layer 104 typically contains abrasive grains and a binder. According to one exemplary embodiment, the abrasive grains are mixed with a binder composition to form an abrasive slurry. Alternatively, abrasive grains are applied (injected) into the binder after coating the binder with a coating on the substrate 102. If necessary, functional powder can be applied over the layer 104 to prevent the layer 104 from sticking to the patterning tool. Alternatively, a pattern may be formed in layer 104 containing no functional powder.

The binder material of the structural coating or dimensional coating can be formed from a single polymer or from a mixture of polymers. For example, a binder material may be formed from epoxy resin, polyacrylate, or a combination thereof. In addition, the binder material may contain a filler, such as a nanoscale filler, or a combination of a nanoscale filler and a micron sized filler. In a specific embodiment, the binder material is a colloidal binder material in which the composition that is cured to form a binder material is a colloidal suspension containing a powder filler. Alternatively or additionally, the binder material may be a nanocomposite binder material that contains a submicron powder filler.

The structured abrasive article 100 may optionally include a pliable coating and a back coating (not shown). These coatings can fulfill the function described above and can be formed from compositions of a binder material.

The binder material typically has a polymer matrix that binds abrasive grains to a substrate or pliable coating, if any. Typically, a binder material is formed from a cured binder composition. According to an exemplary embodiment, the binder composition comprises a polymer component and a dispersed phase.

The binder composition may contain one or more reaction structural constituents or polymer structural constituents for preparing the polymer. The polymer structural component may contain monomeric molecules, polymer molecules, as well as combinations thereof. The binder composition may further comprise components selected from the group consisting of solvents, plasticizers, chain transfer agents, catalysts, stabilizers, dispersing agents, curing agents, reaction mediators, and dispersion flow agents.

Polymeric structural components can form thermoplastics or thermosets. As an example, it is possible to indicate that the polymer structural components may contain monomers and resins to form polyurethane, polyurea, polymerized epoxy resin, polyester, polyimide, polysiloxanes (silicones), polymerized alkyd, butadiene and styrene copolymer, acrylonitrile butadiene copolymer or, generally speaking , reactive resins for the production of thermosetting polymers. As another example, it can be pointed out that the structural components contain an acrylate or methacrylate polymer structural component. The polymeric structural component precursor typically is a curable organic material (i.e., a polymer, monomer or material capable of polymerizing or crosslinking when exposed to heat or another energy source, such as an electron beam, ultraviolet radiation, visible radiation, and the like). or over time with the addition of a chemical catalyst, moisture, or another agent that causes the polymer to cure or polymerize). An exemplary polymer structural component precursor comprises a reactive structural component to form an amino polymer or an aminoplast polymer, such as an alkylated form-urea polymer, a form-melamine polymer, and an alkylated form-benzoguanamine polymer; acrylate polymer which contains acrylate and methacrylate polymer, alkyl acrylate, acrylate epoxy resin, acrylate urethane, acrylate polyester, vinyl ether, acrylate oil or acrylate silicone; an alkyd polymer such as urethane alkyd polymer; polyester polymer; reactive urethane polymer; a phenolic polymer such as resole and novolak; phenolic / latex polymer; an epoxy polymer such as diphenol epoxy polymer; isocyanate; isocyanurate; polysiloxane polymer, including alkyl alkoxysilane polymer; or a reactive vinyl polymer. The binder composition may contain a monomer, oligomer, polymer, as well as combinations thereof. In accordance with a specific embodiment, the composition of the binder material contains monomers of at least two types of polymers, which upon curing can form a transverse (intermolecular) bond. For example, a binder composition may contain epoxy structural components and acrylic structural components that, when cured, form an epoxy / acrylic polymer.

According to an exemplary embodiment, the polymer reaction components comprise anionically and cationically polymerizable precursors. For example, a binder composition may contain at least one cationically curable component, for example at least one cyclic ether component, a cyclic lactone component, a cyclic acetal component, a cyclic thioether component, a spiro orthoester component, an epoxy (epoxy) functional component or an oxetane ( oxetane) functional component. Typically, the binder composition contains at least one component selected from the group consisting of epoxy functional components and oxetane functional components. The binder composition may comprise, based on the total weight of the binder composition, at least about 10 wt.% Cationically curable components, for example at least about 20 wt.%, Typically at least about 40 wt.%, Or at least about 50 wt.%. Typically, the binder composition contains, in terms of total weight, the binder composition of approximately not more than 95% by weight of cationically curable components, for example, approximately not more than 90% by weight, approximately not more than 80% by weight, or approximately not more than 70% by weight .

The binder composition may contain at least one epoxy functional component, for example, an aromatic epoxy functional component ("aromatic epoxy resin") or an aliphatic epoxy functional component ("aliphatic epoxy resin"). Epoxy-functional components are components that contain one or more epoxy groups, that is, one or more three-element ring structures (oxiranes).

Aromatic epoxy components contain one or more epoxy groups and one or more aromatic rings. The binder composition may contain one or more aromatic epoxy components. An exemplary aromatic epoxy component contains an aromatic epoxy resin derived from polyphenol, for example bisphenols such as bisphenol A (4,4'-isopropylidene diphenol), bisphenol F (bis [4-hydroxyphenyl] methane), bisphenol S (4,4'- sulfonyl diphenol), 4,4'-cyclohexesilidene bisphenol, 4,4'-biphenol, or 4,4 '- (9-fluorinylidene) diphenol. Bisphenol can be alkoxylated (e.g. ethoxylated or propoxylated) or halogenated (e.g. brominated). Examples of bisphenol epoxy resins include bisphenol diglycidyl ethers, such as Bisphenol A or Bisphenol F diglycidyl ether.

An additional example of an aromatic epoxy resin is triphenylolmethane triglycidyl ether, 1,1,1-tris (p-hydroxyphenyl) ethane triglycidyl ether, or an aromatic epoxy resin derived from monophenol, e.g. ) Another example is nonylphenyl glycidyl ether.

In addition, an example of an aromatic epoxy resin is epoxy novolak, for example phenol epoxy novolak and cresol epoxy novolak. Examples of commercially available cresol epoxy novolac samples include EPICLON N-660, N-665, N-667, N-670, N-673, N-680, N-690 or N-695, available from Dainippon Ink and Chemicals, Inc. Examples of commercially available phenol epoxy novolac samples include EPICLON N-740, N-770, N-775, or N-865 available from Dainippon Ink and Chemicals, Inc.

In one embodiment, the binder composition may comprise, based on the total weight of the binder composition, at least 10% by weight of one or more aromatic epoxy resins.

Aliphatic epoxy components have one or more epoxy groups and do not contain aromatic rings. The binder composition may contain one or more aliphatic epoxy resins. An example of an aliphatic epoxy is C2-C30 alkyl glycidyl ether; 1.2 C3-C30 alkyl epoxy; mono- or multiglycidyl ether of an aliphatic alcohol or polyol such as 1,4-butanediol, neopentyl glycol, cyclohexane dimethanol, dibromo-neophenyl glycol, trimethylol propane, polytetramethylene oxide, polyethylene oxide, polypropylene oxide, glycerol, and alkoxylated; or polyols.

In one embodiment, the aliphatic epoxy resin contains one or more cycloaliphatic ring structures. For example, an aliphatic epoxy resin may have one or more cyclohexane oxide structures, for example, two cyclohexane oxide structures. An example of a ring-shaped aliphatic epoxy is hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, bis (4-hydroxycyclohexyl) methane diglycidyl-4-ether-3-glycidyl-ether-4-glycidyl ether-4 -epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, di (3,4-epoxycyclohexylmethyl) hexanedioate, di (3,4-epoxy-6-methylcyclohexyl ) g xandioate, ethylene bis (3,4-epoxycyclohexanecarboxylate), ethanedioldi (3,4-epoxycyclohexylmethyl) ether, or 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-1,3 dioxane. Examples of aliphatic epoxy are also shown in US Pat. 6,410,127.

In one embodiment, the binder composition, based on the total weight of the binder composition, comprises at least about 5 weight percent of one or more aliphatic epoxy resins, for example at least about 10 weight percent or at least about 20 weight .% aliphatic epoxy. Typically, the binder composition contains, based on the total weight of the binder composition, about 70 wt.% Aliphatic epoxy resin, for example, about 50 wt.%, About 40 wt.%.

Typically, the binder composition comprises one or more mono or poly glycidyl ethers of aliphatic alcohols, aliphatic polyols or polyether polyols. An example of such a component is 1,4-butanediol diglycidyl ether, polyoxyethylene glycidyl ether or polyoxypropylene glycol or triol with a molecular weight of from about 200 to about 10,000; glycidyl ether polytetramethylene glycol or poly (oxyethylene-oxybutylene) random or block copolymers. Examples of commercially available glycidyl ethers include polyfunctional glycidyl ethers such as Heloxy 48, Heloxy 67, Heloxy 68, Heloxy 107 and Grilonit F713; or monofunctional glycidyl ethers such as Heloxy 71, Heloxy 505, Heloxy 7, Heloxy 8 and Heloxy 61 (sold by Resolution Performances, www.resins.com).

The binder composition may contain from about 3 wt.% To about 40 wt.%, Typically from about 5 wt.% To 20 wt.% Mono- or polyglycidyl ethers of aliphatic alcohol, aliphatic polyol or polyether polyol.

The binder composition contains one or more oxetane-functional components ("oxetanes"). Oxetanes are components having one or more oxetane groups, that is, one or more four-element ring structures containing one oxygen and three carbon elements.

Exemplary oxetanes contain components having the following formula:

wherein

Q1 represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms (such as methyl, ethyl, propyl or butyl group), a fluoroalkyl group having from 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group or a thienyl group a group;

Q2 represents an alkylene group having from 1 to 6 carbon atoms (such as a methylene, ethylene, propylene or butylene group) or an alkylene group having an ether bond, for example an oxyalkylene group such as an oxyethylene, oxypropylene or oxybutylene group;

Z represents an oxygen atom or a sulfur atom; and

R2 represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms (such as a methyl group, an ethyl group, a propyl group or a butyl group), an alkyl group having 2-6 carbon atoms (such as a 1-propenyl group, 2 a propenyl group, a 2-methyl-1-propenyl group, a 2-methyl-2-propenyl group, a 1-butenyl group, a 2-butenyl group or a 3-butenyl group), an aryl group having 6-18 carbon atoms (such as phenyl group, naphthyl group, oranyl group or phenanthyl group), substituted or unsubstituted aralkyl group having 7-18 carbon atoms (such as a benzyl group, fluorobenzyl group, methoxy benzyl group, phenethyl group, styryl group, cinnamyl group, ethoxy benzyl group), an aryloxy group (such as phenoxymethyl group or phenoxyethyl group), an alkylcarbonyl group having 2-6 carbon atoms (such as an ethylcarbonyl group, a propylcarbonyl group or a butylcarbonyl group), an alkoxy carbonyl group having 2-6 carbon atoms (such as an ethoxycarbonyl group, a propoxycarbonyl group or butoxycarbonyl group), an N-alkylcarbamoyl group PU having 2-6 carbon atoms (such as ethylcarbamoyl group, propylcarbamoyl group, butylcarbamoyl group, or pentylcarbamoyl group), or a polyether group having 2-1000 carbon atoms. A particularly useful oxetane is 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane.

In addition to or instead of one or more cationically curable components, the binder composition may contain one or more free radical curable components, for example one or more free radical polymerizable components having one or more ethylenically unsaturated groups, such as (meth) acrylate ( there is acrylate or methacrylate) functional components.

As examples of monofunctional ethylenically unsaturated components, acrylamide, N, N-dimethylacrylamide, (meth) acryloylmorpholine, 7-amino-3,7-dimethyloctyl (meth) acrylate, isobutoxymethyl (meth) acrylamide, isobornyloxyethyl (meth) acrylate, meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl diethylene glycol (meth) acrylate, t-octyl (meth) acrylamide, diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, lauryl (meth) acrylate , dicyclopentadiene (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, N, N-dimethyl (meth) acrylamide tetrachlorophenyl (meth) acrylate, 2-tetrachlorophenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, tetra bromophenyl (meth) acrylate, 2-tetrabromophenoxyethyl (meth) acrylate, 2 trichlorophenoxyethyl (meth) acrylate, tribromophenyl (meth) acrylate, 2-tribromophenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, vinylcaprolactam, N-vinylpyrrolidone, phenoxyethyl (meth) acrylate (meth) acrylate, pentachlorophenyl (meth) acrylate, pentabromophenyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, bornyl (meth) acrylate, methyltriethylene diglycol (meth) acrylate, as well as combinations thereof.

Examples of polyfunctional ethylenically unsaturated components include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, tricyclodecandiyl dimethylene di (meth) acrylate, trimethylolpropane tri ( ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, both terminal adducts of (meth) acrylic acid bisphenol A diglycidyl ether 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, functional derivatives of pentaerythritol (meth) acrylate (e.g. pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate or dipentaerythritol tetra (meth) acrylate), ditrimethylolpropane tetra (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol acrylate, ethoxylated hydrogenated bisphenol A di (meth) acrylate, propoxy th e - modified hydrogenated bisphenol A di (meth) acrylate, ethoxylated bisphenol F di (meth) acrylate, and combinations thereof.

In one embodiment, the binder composition comprises one or more components having at least 3 (meth) acrylate groups, for example, from 3 to 6 (meth) acrylate groups or from 5 to 6 (meth) acrylate groups.

In accordance with specific options, the composition contains, in terms of the total weight of the composition of the binder material, at least about 3 wt.% One or more free radical polymerizable components, for example at least about 5 wt.% Or at least about 9 wt. % As a rule, the continuous phase contains approximately no more than 50% by weight of free radical polymerizable components, for example approximately no more than 35%, approximately no more than 25%, approximately no more than 20% or approximately no more than 15% .

Typically, polymeric reaction structural moieties or their precursors have an average of at least two functional groups, for example an average of at least 2.5 or at least 3.0 functional groups. For example, an epoxy precursor may have 2 or more epoxy functional groups. According to another example, an acrylic precursor may have 2 or more methacrylate functional groups.

It was unexpectedly discovered that a binder composition that contains a component having a polyester backbone shows excellent mechanical (strength) properties after curing the binder composition. Examples of a composition having a polyester backbone include polytetramethylene diol, polytetramethylene diol glycidyl ether, polytetramethylene diol acrylate, polytetramethylene diol containing one or more polycarbonate groups, and combinations thereof. In one embodiment, the composition of the binder material comprises from 5 wt.% To 20 wt.% Of the composition having a polyester backbone.

The binder composition may also contain catalysts and initiators. For example, a cationic initiator can catalyze reactions between cationic polymerizable structural moieties. The radical initiator can activate the free radical polymerization of the radically polymerizable structural components. The initiator can be activated by thermal energy or actinic radiation. For example, the initiator may contain a cationic photoinitiator, which catalyzes the cationic polymerization reaction when exposed to actinic radiation. In accordance with another example, the initiator may contain a radical photoinitiator, which initiates the reaction of free radical polymerization when exposed to actinic radiation. Actinic radiation is radiation with or without particles and includes electron beam radiation and electromagnetic radiation. According to a specific embodiment, electromagnetic radiation is radiation having at least one wavelength in the range of approximately 100 nm to 700 nm and, in particular, wavelengths in the ultraviolet region of the spectrum of electromagnetic radiation.

Typically, cationic photoinitiators are materials that form active species when exposed to actinic radiation and which are capable of at least partially polymerizing epoxy resins or oxetanes. For example, a cationic photoinitiator may, when exposed to actinic radiation, form cations that can initiate reactions of cationically polymerizable components, such as epoxies or oxetanes.

Examples of cationic photoinitiators include onium salts with weak nucleophilic anions, such as the halonium salt, iodonium salt or sulfonium salt described in European Patent Application EP 153904 and WO 98/28663, sulfoxonium salt described, for example, in European patent applications EP 35969, 44274, 54509 and 164314, or the diazonium salt described, for example, in US patents 3,708,296 and 5,002,856. As another example of a cationic photoinitiator, the metallocene salt described, for example, in European Patent Application Laid-open No. EP 94914 and 94915.

In accordance with exemplary options, the composition of the binder material contains one or more photoinitiators having the formula (1) or (2):

in which

Q3 represents a hydrogen atom, an alkyl group having from 1 to 18 carbon atoms, or an alkoxyl group having from 1 to 18 carbon atoms;

M represents a metal atom, for example antimony;

Z represents a halogen atom, for example fluorine; and

t represents the valence number of the metal, for example 5 in the case of antimony.

In accordance with specific examples, the composition of the binder material, calculated on the total weight of the composition of the binder material, is from about 0.1 wt.% To 15 wt.% Of one or more cationic photoinitiators, for example, from about 1 wt.% To 10 wt.%.

Typically, a photoinitiator in the form of an onium salt contains an iodonium complex salt or a sulfonium complex salt. Useful aromatic onium complex salts are described, for example, in US Pat. 4,256,828. An exemplary aromatic iodonium complex salt contains diaryl iodonium hexafluorophosphate or diaryl iodonium hexafluoroantimonate. An exemplary aromatic sulfonium complex salt contains triphenyl sulfonium hexafluoroantimonate, p-phenyl (thiophenyl) diphenyl sulfonium hexafluoroantimonate or sulfonium (thiodio-4,1-phenylene) bis (diphenyl bis ((OS-6-11) hexafluoroantimonate)).

Aromatic onium salts are typically photosensitive only in the ultraviolet region of the spectrum. However, they can be sensitized in the near ultraviolet region of the spectrum and in the optical region of the spectrum using sensitizers with known organic halogen structural components. An exemplary sensitizer that contains an aromatic amine or a colored aromatic polycyclic hydrocarbon is described, for example, in US Pat. 4,250,053.

Suitable radiation-activated organometallic complex salts are described, for example, in US Pat. Nos. 5,059,701; 5,191.101; and 5,252,694. An exemplary organometallic complex salt, which is used as a radiation activated initiator, contains: (η ⁶ -benzene) (η ⁵ -cyclopentadienyl)

Fe ⁺¹ SbF ₆ ^- , (η ⁶ -toluene) (η ⁵ -cyclopentadienyl) Fe ⁺¹ AsF ₆ ^- , (η ⁶ -xylene) (η ⁵ -cyclopentadienyl) Fe ^{+ l} SbF ₆ , (η ⁶ -cumol) (η ⁵ -cyclopentadienyl) Fe ^{+ l} PF ₆ ^- , (η ⁶ -xylene (mixed isomers) (η ⁵ -cyclopentadienyl) Fe ^{+ l} SbF ₆ ^- , (η ⁶ -xylene (mixed isomers) (η ^5- cyclopentadienyl) Fe ^{+ l} PF ₆ ^- , (η ⁶ -o-xylene) (η ^5- cyclopentadienyl) Fe ^{+ l} CF ₃ SO ₃ ^- , (η ⁶ -m-xylene) (η ^5- cyclopentadienyl) Fe ^{+ l} BF ₄ ^- , (η ^6- mesitylene) (η ^5- cyclopentadienyl) Fe ^{+ l} SbF ₆ ^- , (η ^6- hexamethylbenzene) (η ^5- cyclopentadienyl) Fe ^{+ l} SbF ₅ OH ^- , (η ^6- fluorine) (η ⁵ - cyclopentadienyl) Fe ^{+ l} SbF ₆ ^- , as well as combinations thereof.

Optionally, the organometallic salt catalysts can be used in conjunction with an accelerator such as tertiary alcohol ethyl oxalate. If it is, then the accelerator is preferably approximately from 0.1% to 4% by weight, calculated on the total weight of the binder composition of the binder material.

A useful commercially available cationic photoinitiator that contains an aromatic sulfonium complex salt is sold, for example, under the trade name "FX-512" by Minnesota Mining and Manufacturing Company, St. Paul, Minn., And under the trade name "UVI-6974" by Dow Chemical Co., or Chivacure 1176.

The binder composition, if necessary, may contain photoinitiators useful for the photocuring of free radical polyfunctional acrylates. Examples of free radical photoinitiators include benzophenone (for example, alkyl substituted benzophenone or alkoxy substituted benzophenone); benzoic compounds (for example, benzoic esters such as benzoic methyl ether, benzoic ethyl ether, benzoic isopropyl ether, benzoic phenyl ether and benzoic acetate); acetophenone such as 2,2-dimethoxyacetophenone, 4- (phenylthio) acetophenone and 1,1-dichloroacetophenone; benzyl ketal such as benzyl dimethyl ketal and benzyl diethyl ketal; anthraquinone such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; triphenylphosphine; benzoylphosphine oxides, such as, for example, 2,4,6-trimethylbenzoyl diphenylphosphine oxide; thioxantone or xanton; acridine derivative; phenacene derivative; quinoxaline derivative; 1-phenyl-1,2-propadion-2-0-benzoyloxy; 1-aminophenyl ketone or 1-hydroxyphenyl ketone, such as 1-hydroxycyclohexyl phenyl ketone, phenyl (1-hydroxyisopropyl) ketone and 4-isopropylphenyl (1-hydroxyisopropyl) ketone; or a triazine compound, for example 4 ″ methyl thiophenyl-1-di (trichloromethyl) -3,5-8-triazine, S-triazine-2- (stilbene) -4,6-bistrichloromethyl or parametoxy styryl triazine.

An exemplary photoinitiator comprises a benzoic resin or its derivatives, such as α-methylbenzoin; U-phenylbenzoin; α-allylbenzoin; α-benzylbenzoin; benzoic esters such as benzyl dimethyl ketal (which can be purchased, for example, from Ciba Specialty Chemicals under the trade name "IRGACURE 651"), benzoic methyl ether, benzoic ethyl ether, benzoic n-butyl ether; acetophenone or its derivatives, such as 2-hydroxy-2-methyl-1-phenyl-1-propanone (which can be purchased, for example, from Ciba Specialty Chemicals under the trade name "DAROCUR 1173") and 1-hydroxycyclohexyl phenyl ketone ( which can be purchased, for example, from Ciba Specialty Chemicals under the trade name "IRGACURE 184"); 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone (which can be purchased, for example, from Ciba Specialty Chemicals under the trade name "IRGACURE 907"); 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone (which can be purchased, for example, from Ciba Specialty Chemicals under the trade name "IRGACURE 369"); as well as mixtures thereof.

Another suitable free radical photoinitiator contains the composition of an ionic dye - a counteracting ion that can absorb actinic rays and create free radicals that can initiate the polymerization of acrylates. Such a photoinitiator is described, for example, in European Patent Application Laid-Open No. 223587 and in US Pat. Nos. 4,751,102, 4,772,530 and 4,772,541.

The photoinitiator may be present in an amount of approximately not more than 20% by weight, for example, approximately not more than 10% by weight, and typically approximately not more than 5% by weight, based on the total weight of the binder composition. For example, the photoinitiator may be present in an amount of from 0.1 wt.% To 20.0 wt.%, For example from 0.1 wt.% To 5.0 wt.%, Or, most typically, from 0.1 wt.% To 2.0 wt.% In terms of full the weight of the binder composition, although other amounts outside the ranges indicated are possible. In one example, the photoinitiator is present in an amount of at least about 0.1 wt.%, For example at least about 1.0 wt.% Or in an amount of from 1.0 wt.% To 10.0 wt.%.

If necessary, a thermal hardener may be included in the composition of the binder material. Such a thermal hardener is usually thermally stable at temperatures at which the components are mixed. Exemplary thermal hardeners for epoxy resins and acrylates are well known in the art and are described, for example, in US Pat. 6,258,138. A thermal hardener may be present in the binder precursor in any effective amount. Such amounts typically lie in the range of about 0.01 wt.% To 5.0 wt.%, Mainly in the range of about 0.025 wt.% To 2.0 wt.%, Calculated on the weight of the binder composition, although quantities outside of these may be used. ranges.

The binder composition may also contain other components, such as solvents, plasticizers, crosslinkers, chain transfer agents, stabilizers, dispersing agents, curing agents, reaction agents and agents for influencing the dispersion flow. For example, a binder composition may contain one or more chain transfer agents selected from the group consisting of polyol, polyamine, linear or branched polyglycol ether, polyester and polylactone.

According to another example, the binder composition may contain additional components, such as a hydroxy functional or amine functional component and an additive. As a rule, a specific hydroxy functional component does not contain curable groups (such as, for example, acrylate, epoxy or oxetane groups) and is not selected from the group consisting of photoinitiators.

The binder composition may contain one or more hydroxy functional components. Hydroxy functional components may be useful for further fine-tuning the mechanical properties of the binder composition after curing. The hydroxy functional component contains a monol (hydroxy functional component containing one hydroxyl group) or a polyol (hydroxy functional component containing several hydroxyl groups).

Representative examples of hydroxy functional components are alkanol, monoalkyl ether of polyoxyalkylene glycol, monoalkyl ether of alkylene glycol, alkylene glycol and arylalkylene glycol such as 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,3-heptantriol, 2 6-dimethyl-1,2,6-hexanetriol, (2R, 3R) - (-) - 2-benzyloxy-1,3,4-butanetriol, 1,2,3-hexanetriol, 1,2,3-butanetriol , 3-methyl-1,3,5-pentantriol, 1,2,3-cyclohexanetriol, 1,3,5-cyclohexanetriol, 3,7,11,15-tetramethyl-1,2,3-hexadecantriol, 2-hydroxymethyltetrahydropyran -3,4,5-triol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,3-c clopentanediol, trans-1,2-cyclooctanediol, 1,16-hexadecanediol, 3,6-dithia-1,8-octanediol, 2-butyn-1,4-diol, 1,2- or 1,3-propanediol, 1 2- or 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1-phenyl-1,2-ethanediol, 1,2-cyclohexanediol, 1,5-decalindiol, 2,5-dimethyl-3-hexine-2,5-diol, 2,2,4-trimethylpentane-1,3-diol, neopentyl glycol, 2-ethyl-1, 3-hexanediol, 2,7-dimethyl-3,5-octadin-2-7-diol, 2,3-butanediol, 1,4-cyclohexanedimethanol, polyoxyethylene or polyoxypropylene glycols or triodes with a molecular weight of about 200 to 10,000, polytetramethylene glik oli with different molecular weights, poly (oxyethylene-oxybutylene) random or block copolymers, copolymers containing suspended hydroxyl groups formed by hydrolysis or partial hydrolysis of vinyl acetate copolymers, polyvinyl acetal resins containing suspended hydroxyl groups, hydroxy functional (e.g. hydroxy complete) polyesters or hydroxy functional (e.g. hydroxy complete) polylactones, aliphatic polycarbonate polyols (e.g. aliphatic polycarbonate diol), hydro xy functional (e.g. hydroxy complete) polyesters (e.g. polytetrahydrofuran polyols having a weight average molecular weight in the range of 150-4000 g / mol, 150-1500 g / mol or 150-750 g / mol), as well as combinations thereof. An exemplary polyol further comprises an aliphatic polyol, such as glycerol, trimethylpropane, or a sugar alcohol, such as erythritol, xylitol, mannitol, or sorbitol. In accordance with specific embodiments, the binder composition contains one or more alicyclic polyols, such as 1,4-cyclohexane-dimethanol, sucrose, or 4,8-bis (hydroxymethyl) tricyclo (5.2.1.0) decane.

A suitable polyester for the binder composition is, in particular, a linear or branched polyglycol ether obtained by ring-opening polymerization of a cyclic ether in the presence of a polyol, for example the aforementioned polyol; polyglycol ether, polyethylene glycol, polypropylene glycol or polytetramethylene glycol or a copolymer thereof.

Another suitable polyester for the binder composition is a polyester based on polyols and aliphatic, cycloaliphatic or aromatic polyfunctional carbolic acids (e.g. dicarboxylic acids), or which specifically contains all the corresponding saturated polyesters that are liquid at temperatures from 18 ° C to 300 ° C, typically from 18 ° C to 150 ° C: typically amber ether, glutaric ether, adipic ether, lemon ether, phthalic ether, isophthalic ether, terephthalic ether or ether, respectively etstvuyuschih hydrogenation products, with the alcohol component being composed of monomeric or polymeric polyols, for example polyols of the aforementioned kind.

Another possible polyester contains an aliphatic polylactone, such as ε-polycaprolactone, or polycarbonate, which, for example, can be obtained by polycondensation of the diol with phosgene. For the binder composition, bisphenol A polycarbonate typically having a weight average molecular weight of 500 to 100,000 is typically used.

To affect the viscosity of the composition of the binder material and, in particular, to reduce the viscosity or liquefaction, the polyol, polyester or saturated polyester or mixtures thereof can, if necessary, be mixed with suitable additives, in particular with a solvent, plasticizer, diluent, etc. . In accordance with one embodiment, the compositions may comprise, based on the total weight of the binder composition, approximately no more than 15% by weight, for example, approximately no more than 10% by weight, approximately no more than 6% by weight, approximately no more than 4% by weight , approximately not more than 2 wt.% or about 0 wt.% hydroxy-functional component. In accordance with one example, the composition of the binder material does not contain significant amounts of a hydroxy functional component. The absence of significant quantities of hydroxy functional components may reduce the hygroscopicity of the compositions of the binder material or products derived from them.

An exemplary hydroxy or amine functional organic compound for the preparation of a condensation product (cure) with alkylene oxide contains a polyol having from 3 to 20 carbon atoms (C1-C8) alkanol amides (C8-C18) fatty acids such as ethanol fatty acid amides fatty alcohols, alkyl phenol or diamine having from 2 to 5 carbon atoms. Such compounds react with alkylene oxide, such as ethylene oxide, propylene oxide, or mixtures thereof. The reaction can take place at a molar ratio of hydroxy or amine of the organic compound to alkylene oxide, which is, for example, from 1: 2 to 1:65. The condensation product typically has a weight average molecular weight of about 500 to 10,000 and can be a branched, cyclic, linear homopolymer, copolymer or terpolymer.

The binder composition may further comprise a dispersing agent for reacting with the surface of the powder filler to modify it. For example, this dispersing agent may contain organosiloxane, functionalized organosiloxane, an alkyl substituted pyrrolidone, polyoxyalkylene ether, a copolymer of ethylene oxide and propylene oxide, as well as combinations thereof. In the case of various powder fillers and, in particular, a filler in the form of silicon dioxide, a suitable surface modifier contains siloxane.

An example of a siloxane is a functionalized or non-functionalized siloxane. Exemplary siloxane has a composition corresponding to the following formula:

in which each R represents independently substituted or unsubstituted linear, branched or cyclic C1-10 alkyl, C1-10 alkoxy, a group containing substituted or unsubstituted aryl, aryloxy, trialoalkyl, cyanoalkyl or vinyl; B1 or B2 represents hydrogen, a group containing siloxy, vinyl, silanol, alkoxy, amine, epoxy, hydroxy, (meth) acrylate, mercapto or solvent repellent groups, such as lipophilic or hydrophilic (for example, anionic, cationic) groups; and n is an integer from about 1 to about 10,000, in particular from about 1 to about 100.

Generally speaking, functionalized siloxane is a compound having a molecular weight in the range of about 300 to 20,000. Such compounds can be purchased, for example, from General Electric Company or Goldschmidt, Inc. A typical functionalized siloxane is an amine functionalized siloxane in which functionalization typically completes the siloxane.

Exemplary organosilaxanes are sold under the trade name Silwet by Witco Corporation. Such organosilaxanes typically have a weight average molecular weight of about 350 to 15,000, have hydrogen or C1-C4 alkyl ends, and can be hydrolyzable or non-hydrolyzable. Typical organosilaxanes sold under the trade name Silwet L-77, L-7602, L-7604 and L-7605 are polyalkylene oxide modified dialkyl polysiloxanes.

Examples of suitable anionic dispersing agents include (C8-C16) alkylbenzene sulfonate, (C8-C16) alkane sulfonate, (C8-C18) α-olefin sulfonate, α-sulfo methyl ether (C8-C16) fatty acid, sulfate (C8-C16) fatty acids, mono- or dialkyl sulfosuccinate, each alkyl independently being a (C8-C16) alkyl group, an alkyl ether sulfate, (C8-C16) carboxylic acid salt or isothionate having an approximate fatty chain 8 to 18 carbon atoms, e.g. sodium diethylhexyl sulfosuccinate, methyl nzol sodium sulfonate, or sodium bis (2-ethylhexyl) sulfosuccinate (e.g. Aerosol OT or AOT).

A typical dispersant is a compound selected from the group consisting of organosilaxane, functionalized organosilaxane, alkyl substituted pyrrolidone, polyoxyalkylene ether, or a block copolymer of ethylene oxide and propylene oxide.

Cyclic organosilicones (e.g., SF1204, SF1256, SF1328, SF1202 (decamethyl-cyclopentasiloxane (pentamer)), SF1258, SF1528, Dow Coming 245 fluids, Dow Coming 246 fluids, dodecamethyl-cyclohex can be mentioned as examples of serial dispersing agents (heximer), and SF1173), a copolymer of polydimethylsiloxane and polyoxyalkylene oxide (e.g., SF1488 and SF1288); linear silicones, including oligomers (e.g. Dow Coming 200 (R) fluids); Silwet L-7200, Silwet L-7600, Silwet L-7602, Silwet L-7605, Silwet L-7608 or Silwet L-7622; non-ionic surfactants (e.g. Triton X-100, Igepal CO-630, PVP Series, Airvol 125, Airvol 305, Airvol 502 and Airvol 205); organic polyesters (e.g. Surfynol 420, Surfynol 440 and Surfynol 465); or Solsperse 41000.

As another example of serial dispersing agents, SF1173 (GE Silicones); an organic polyester such as Surfynol 420, Surfynol 440 and Surfynol 465 (Air Products Inc); Silwet L-7200, Silwet L-7600, Silwet L-7602, Silwet L-7605, Silwet L-7608 or Silwet L-7622 (Witco); or a nonionic surfactant such as Triton X-100 (Dow Chemicals), Igepal CO-630 (Rhodia), PVP Series (ISP Technologies) and Solsperse 41000 (Avecia).

The amount of dispersing agent ranges from 0 wt.% To 5 wt.%, And more typically ranges from 0.1 wt.% To 2 wt.%. Silanes are typically used at concentrations from 40 mol. % to 200 mol. % and, in particular, from 60 mol. % to 150 mol. % in terms of the molecular amount of surface-active sites on the surface of the nanoscale powder filler. Typically, the binder composition contains approximately not more than 5 wt.% Dispersing agent, for example, from about 0.1 wt.% To 5.0 wt.% Dispersing agent, calculated on the total weight of the binder composition.

The binder composition may further comprise a dispersed phase suspended in a continuous phase. The continuous phase typically contains polymer structural components. The dispersed phase usually contains a powder filler. The powder filler may be formed from inorganic particles, such as, for example, metal particles (such as, for example, steel, silver or gold) or particles of a metal complex, such as, for example, metal oxide, metal hydroxide, metal sulfide, metal- halogen, metal carbide, metal phosphate, particles of an inorganic salt (such as, for example, CaCO ₃ ), ceramics, or combinations thereof. Examples of metal oxides include ZnO, CdO, SiO ₂ , TiO ₂ , ZrO ₂ , CeO ₂ , SnO ₂ , MoO ₃ , WO ₃ , Al ₂ O ₃ , In ₂ O ₃ , La ₂ O ₃ , Fe ₂ O ₃ , CuO, Ta ₂ O ₅ , Sb ₂ O ₃ , Sb ₂ O ₅ , as well as combinations thereof. Mixed oxides that contain various metals may also be present. Nanoparticles can be, for example, particles from a material selected from the group consisting of ZnO, SiO ₂ , TiO ₂ , ZrO ₂ , SnO ₂ , Al ₂ O ₃ , co-formed silica and alumina, as well as mixtures thereof. Particles of nanometer size may also have an organic component, such as, for example, carbon black; firmly crosslinked core shell polymeric nanoparticles; organically modified particles of nanometer size, etc. Such excipients are described, for example, in US Pat. 6,467,897 and in WO 98/51747.

A powder filler formed by solution-based processes, such as sol formed and sol-gel formed ceramics, is particularly suitable for use in a composite binder. Suitable sols are commercially available. For example, colloidal silicas in aqueous solutions are commercially available under such trademarks as “LUDOX” (EI DuPont de Nemours and Co., Inc. Wilmington, Del.), “NYACOL” (Nyacol Co., Ashland, MA.) and "NALCO" (Naico Chemical Co., Oak Brook, I11.). Many commercially available sols are basic and are stabilized with alkali, such as sodium hydroxide, potassium hydroxide or ammonium hydroxide. Further examples of suitable colloidal silicas (silica) are described in US Pat. No. 5,126,394. Particularly suitable is the sol formed by silica and the sol formed by alumina. Sols can be formed by introducing into the reaction one or more appropriate surface treatment agents with inorganic oxide base particles in the sol.

According to a specific embodiment, the powder filler has a submicron size. For example, the powder filler may be a nanoscale powder filler, such as a powder filler, having an average particle size of from about 3 nm to about 500 nm. According to an exemplary embodiment, the powder filler has an average particle size of approximately 3 nm to 200 nm, for example approximately 3 nm to 100 nm, approximately 3 nm to 50 nm, approximately 8 nm to 30 nm, or approximately 10 nm to 25 nm In accordance with specific options, the average particle size is approximately not more than 500 nm, for example, approximately not more than 200 nm, approximately less than 100 nm, or approximately not more than 50 nm. The average particle size of the powder filler can be defined as the particle size corresponding to the peak volume fraction in the distribution curve for low angle neutron scattering (SANS), or as the particle size corresponding to 0.5 accumulated volume fraction in the SANS distribution curve.

Powder filler can also be characterized using a narrow distribution curve, half the width of which approximately does not exceed twice the average particle size. For example, half the width may not exceed approximately 1.5 or approximately no more than 1.0 of the average particle size. Half the width of the distribution curve is measured at half its height, which corresponds to half the fraction of particles at the peak of the distribution curve. In accordance with a specific embodiment, the particle size distribution curve is monomodal. In an alternative embodiment, the particle size distribution is bimodal or has several peaks.

In accordance with a specific embodiment, the composition of the binder material may contain at least two powder fillers. Each of the powder fillers can be formed from the materials described above for powder fillers. Powder fillers may contain the same material or different materials. For example, each of the powder fillers may be formed from silica. In an alternative example, one filler may be formed from silica, and another filler may be formed from alumina. In accordance with one example, each of the powder fillers has a particle size distribution having an average particle size of approximately not more than 1000 nm, for example, approximately not more than 500 nm, or approximately less than 100 nm. In another example, one of the powder fillers has a particle size distribution having an average particle size of approximately not more than 1000 nm, for example approximately not more than 500 nm or approximately less than 100 nm, while the second powder filler has an average particle size of approximately more than 1 μm, for example, approximately 1 μm to 10 μm, or approximately 1 μm to 5 μm. Alternatively, the second powder filler may have a large average particle size such as 1,500 microns. In a specific embodiment, a binder composition that contains a first powder filler having a submicron average particle size and a second powder filler having an average particle size of greater than 1 μm advantageously provides improved mechanical properties after curing to form a binder material.

Typically, the second powder filler has a low aspect ratio. For example, the second powder filler may have a shape factor of approximately no more than 2, for example about 1, with the particles being almost spherical. As a rule, the second powder filler is not subjected to processing and does not harden due to various types of processing. In contrast, abrasive grains are typically hardened and have a shape factor of at least about 2 and sharp edges.

When a second powder filler is selected, the deposition rate and viscosity are usually taken into account. As the particle size in the powder filler increases, the deposition rate increases, and the viscosity decreases with increasing load. In addition, the refractive index of the powder filler is sometimes taken into account. For example, a powder filler with a refractive index of at least about 1.35 may be selected. In addition, a powder filler may be selected that does not contain a basic residue, since the basic residue may adversely affect the polymerization of cationically polymerizable structural components.

The powder filler is typically dispersed in a binder composition. Prior to curing, the powder filler is colloidal dispersed in a suspension of binder material and forms a colloidal composite binder material after curing. For example, the powder material can be dispersed so that the Brownian motion supports the powder filler in suspension. As a rule, the powder filler mainly does not contain particle agglomerates. For example, the powder filler can be mainly monodisperse, so that the powder filler is dispersed as separate particles and, in accordance with specific examples, has only a small number of particle agglomerates, if any.

In a specific embodiment, the particulate filler particles are mainly spherical. Alternatively, the particles may have a primary shape factor of greater than 1, for example at least about 2, at least about 3, or at least about 6, the primary shape factor being the ratio of the longest to smallest size orthogonal to the longest size . Particles can also be characterized by a secondary shape factor, which is the ratio of orthogonal dimensions in a plane, mainly perpendicular to the longest size. The particles can be needle-shaped, with a primary shape factor of at least about 2 and a secondary shape factor of about 2, for example, about 1. Alternatively, the particles can have a plate shape, with a primary shape factor of at least about 2 and a secondary shape factor of at least about 2.

According to an exemplary embodiment, a powder filler is prepared in an aqueous solution and mixed with a suspension binder composition. The process of preparing such a suspension involves the use of an aqueous solution, such as an aqueous solution of silicate; polycondensation of silicate to a particle size of from 3 nm to 50 nm; finishing the obtained silica sol to alkaline pH; possibly a thickening of the sol; mixing the sol with the structural components of the external liquid phase of the suspension and, possibly, removing water or other solvent components from the suspension. For example, an aqueous silicate solution, such as an alkali metal silicate solution (for example, a sodium silicate or potassium silicate solution) with a concentration in the range of 20 wt.% To 50 wt.%, Based on the weight of the solution, is added. Then, silicate is polycondensed to particles ranging in size from 3 to 50 nm, for example, by treating the silicate solution with acid ion exchangers. The resulting silicate sol is adjusted to an alkaline pH (e.g., pH> 8) to prevent further polycondensation or agglomeration of existing particles. It is possible that the sol is concentrated, for example, by distillation, typically up to a SiO ₂ concentration of approximately 30 to 40% by weight. Then the sol is mixed with the structural components of the external liquid phase. After that, water or other solvent components are removed from the suspension. According to a specific embodiment, the suspension is substantially water free.

The continuous phase fraction in the pre-cured binder composition typically contains organic polymer structural components, so that the proportion of the binder composition can be from about 20% to 95% by weight, for example from about 30% to 95% by weight, typically from about 50% up to 95% by weight, and even better, roughly from 55% to 80% by weight. The phase fraction of the dispersed powder filler can be from about 5% to 80% by weight, for example from about 5% to 70% by weight, typically from about 5% to 50% by weight, and even better, from about 20% to 45% by weight. The colloidal dispersed and submicron powder fillers described hereinabove are particularly useful at concentrations of at least about 5 wt.%, For example at least about 10 wt.%, At least about 15 wt.%, At least about 20 wt. .% or up to 40 wt.% or higher. Unlike traditional fillers, nanocomposites formed in solution have a low viscosity and improved processing characteristics at a higher load. The number of components is expressed in weight percent, calculated on the total weight of the composition of the binder material, unless otherwise specified.

In accordance with a specific embodiment, the composition of the binder material contains approximately 10 wt.% To 90 wt.% Cationically polymerizable compounds, approximately no more than 40 wt.% Radically polymerizable compounds and approximately 5 wt.% To 80 wt.% Powder aggregate in terms of the total weight of the binder composition. It should be borne in mind that the sum of the quantities of the components of the composition of the binder material is added up to 100 wt.% And, thus, when the quantities of one or more components are specified, the quantities of the other components will be such that the sum of the quantities is not more than 100 wt.%.

The cationically polymerizable compound contains, for example, an epoxy functional component or an oxetane functional component. For example, a binder composition may comprise from about 10 wt.% To 60 wt.% Of a cationically polymerizable compound, for example from about 20 wt.% To 50 wt.% Of a cationically polymerizable compound, based on the weight of the binder composition. An exemplary binder composition may contain approximately no more than 20% by weight, for example, approximately 5% to 20% by weight of mono- or polyglycidyl ethers of aliphatic alcohol, aliphatic polyols, polyether polyol or polyether polyol. An exemplary binder composition may contain approximately no more than 50% by weight, for example, approximately 5% to 50% by weight, of a component having a polyester backbone, such as polytetramethylene diol, polytetramethylene diol glycidylethers, polytetramethylene diol acrylates or one or more polytetramethylene diol acrylates groups.

The radical polymerizable composition according to the above example contains, for example, components having one or more methacrylate groups, for example, components having at least 3 methacrylate groups. According to another example, the composition of the binder material contains approximately no more than 30% by weight, for example approximately no more than 20% by weight, approximately no more than 10% by weight, or approximately no more than 5% by weight of a radically polymerizable composition.

The binder composition may further comprise approximately not more than 20% by weight of a cationic photoinitiator, for example from approximately 0.1% to 20% by weight, or approximately not more than 20% by weight of a radical photoinitiator, for example from approximately 0.1% to 20% the weight.%. For example, the composition of the binder material may contain approximately no more than 10 wt.%, For example, approximately no more than 5 wt.% Cationic photoinitiator. In accordance with another example, the composition of the binder material may contain approximately no more than 10 wt.%, For example, approximately no more than 5 wt.% Free radical photoinitiator.

Powder filler contains dispersed submicron particles. Typically, the binder composition contains from 5 wt.% To 80 wt.%, For example from 5 wt.% To 60 wt.%, From 5 wt.% To 50 wt.% Or from 20 wt.% To 45 wt. % submicron powder filler. In accordance with specific embodiments, the binder composition contains at least about 5 wt.% Powder filler, for example at least about 10 wt.% Or at least about 20 wt.%. According to a specific embodiment, the powder filler is a silica powder formed in solution and can be colloidally dispersed in the polymer component. An exemplary binder composition may further comprise approximately not more than 5 wt.% Dispersing agent, for example from 0.1 wt.% To 5 wt.% Dispersing agent selected from the group consisting of organosilaxane, functionalized organosilaxane, alkyl substituted pyrrolidone, polyoxyalkylene ether and block is a copolymer of ethylene oxide and propylene oxide.

According to a specific embodiment, the binder composition is formed by mixing a nanocomposite epoxy or acrylate precursor, that is, a precursor that contains a submicron powder filler. For example, the binder composition may contain approximately no more than 90 wt.% Nanocomposite epoxy resin and may contain an acrylic precursor, for example, no more than 50 wt.% Acrylic precursor. In accordance with another example, a nanocomposite acrylic precursor may be mixed with an epoxy resin.

A binder composition that contains polymer or monomeric structural components and contains dispersed powder filler can be used to form (form) a structural coating, dimensional coating, malleable coating or back coating of an abrasive flexible tool. In an exemplary method of forming a structural coating, the binder material composition is coated onto a substrate, abrasive grains are applied over the structural coating, and the structural coating is partially cured prior to the formation of the pattern. A dimensional coating can be applied over a structural coating and abrasive grains. In accordance with another exemplary embodiment, the binder composition is mixed with abrasive grains to form an abrasive slurry that is coated onto a substrate, partially cured, and patterned.

Abrasive grains can be abrasive grains formed from any material or combination of materials, the material being silica, alumina (fused or sintered), zirconia, fused zirconia and alumina, silicon carbide, garnet, diamond, cubic boron nitride , silicon nitride, cerium dioxide, titanium dioxide, titanium diboride, boron carbide, tin oxide, tungsten carbide, titanium carbide, iron oxide, chromium oxide, powdered quartz and corundum. For example, the abrasive grain material may be selected from the group consisting of silica, alumina, zirconia, silicon carbide, silicon nitride, boron nitride, garnet, diamond, fused alumina and zirconia, cerium dioxide, titanium diboride, carbide boron, powdered quartz, corundum, aluminum nitride, and also mixtures thereof. In particular embodiments, dense abrasive grains that mainly comprise alpha alumina can be used.

Abrasive grains can also have a special shape. Examples of such a shape include a rod, a triangle, a pyramid, a cone, a solid sphere, a hollow sphere, etc. Alternatively, abrasive grains may have a random shape.

Abrasive grains usually have an average grain size of not more than 2000 microns, for example, approximately not more than 1500 microns. In accordance with another example, the average grain size is approximately not more than 750 microns, for example, approximately not more than 350 microns. For example, the average grain size may be at least 0.1 μm, for example, approximately from 0.1 μm to 1500 μm, and more typically approximately from 0.1 μm to 200 μm, or approximately 1 μm to 100 μm. The abrasive grain size is typically set as the longest abrasive grain size. As a rule, there is a range of grain size distribution. In some cases, the grain size distribution is carefully controlled.

In a mixed abrasive slurry containing abrasive grains and a binder composition, the abrasive grains comprise approximately 10% to 90%, for example approximately 30% to 80%, based on the weight of the abrasive suspension.

The abrasive slurry may further comprise a grinding aid to increase grinding efficiency and increase cutting speed. A useful grinding aid may be an inorganic base, such as a halide salt, for example sodium cryolite and potassium tetrafluoroborate; or an organic base such as chlorinated wax, for example polyvinyl chloride. In a particular embodiment, cryolite and potassium tetrafluoroborate are used with particle sizes ranging from 1 μm to 80 μm, and most typically from 5 μm to 30 μm. The content of the grinding aid is usually approximately not more than 50 wt.%, For example, approximately from 0 wt.% To 50 wt.%, And most typically approximately from 10 wt.% To 30 wt.% In terms of the total weight of the abrasive slurry (including abrasive grain).

A binder composition can be used to form a structured abrasive article. For example, the composition of a binder material can be applied to a substrate, partially cured and made curly (converted into a pattern) to form abrasive structures. According to a specific embodiment, a structured abrasive article may be formed without using functional powder.

Figure 2 shows an exemplary process. Substrate 202 is deployed from roll 204. Substrate 202 is coated with a binder composition 208 dispensed from a coating device 206. An exemplary coating device comprises a coating device with a drop die, a doctor blade for coating, an irrigation coating device , a coating device with a vacuum stamp or a coating device with a stamp. Coating methodologies may include contact or non-contact methods. In such methods, 2 rollers, 3 reversible rollers, a knife on top of the roller, a slot die, gravure printing, extrusion or spray coating can be used.

In a specific embodiment, the binder composition 208 is a suspension that contains the composition and abrasive grains. Alternatively, the binder composition 208 is distributed separately from the abrasive grains. Abrasive grains can be applied after coating the substrate 202 with the binder composition 208, after partially curing the binder composition 208, after drawing a pattern on the binder composition 208, or after completely curing the binder composition 208. Abrasive grains, for example, can be applied using techniques such as electrostatic coating, drop coating or mechanical throwing.

The binder composition is partially cured using an energy source 210. The choice of energy source 210 partially depends on the chemical composition of the binder material composition. The energy source 210 may be a source of thermal energy or actinic radiation energy, such as an electron beam, ultraviolet radiation, or visible radiation. The amount of energy used depends on the chemical nature of the reactive groups in the precursor of the polymer structural components, as well as on the thickness and density of the binder material composition 208. In the case of a heat energy source, a furnace temperature of approximately 75 ° C to 150 ° C and a processing time of approximately 5 minutes to 60 minutes are usually sufficient. Emission of an electron beam or ionizing radiation can be used with an energy level of approximately 0.1 mrad to 100 mrad, in particular with an energy level of approximately 1 mrad to 10 mrad. Ultraviolet radiation is radiation having a wavelength in the range of approximately 200 nm to 400 nm, in particular in the range of approximately 250 nm to 400 nm. Visible radiation is radiation having a wavelength in the range of approximately 400 nm to 800 nm, in particular in the range of approximately 400 nm to 550 nm. Curing parameters, such as exposure, usually depend on the composition and can be set by changing the lamp power and speed of the conveyor belt.

In an exemplary embodiment, the energy source 210 generates actinic radiation to partially cure the binder material composition 208 covering the substrate. In another embodiment, the binder material composition 208 is thermally curable and the energy source 210 creates heat for heat treatment. In another embodiment, the binder composition 208 may comprise actinic radiation curable components and thermally curable components. The binder composition itself can be partially cured by using the first thermal cure and actinic radiation curing and completely cured by using the second thermal curing and actinic radiation curing. For example, the epoxy structural component of the binder composition can be partially cured by the use of ultraviolet radiation, and the acrylic structural component of the binder composition can then be cured by the use of thermal curing.

According to a specific embodiment, the binder composition 208 has a viscosity of not more than 3000 centipoise at room temperature (21 ° C, or 70 ° F). For example, the composition 208 of the binder material 208 prior to curing may have a viscosity of approximately not more than 2000 centipoise, for example, approximately not more than 1500 centipoise, approximately not more than 1000 centipoise, or approximately not more than 500 centipoise at room temperature. Alternatively, the binder composition 208 may have a viscosity in excess of 3000 centipoise. The uncured binder composition alone or in an abrasive slurry is usually fluid at the temperature and pressure at which the coating process is carried out. For example, an uncured binder composition may be fluid at temperatures of approximately not more than 60 ° C (140 ° F). The binder composition 208 may be partially cured prior to patterning to a viscosity of, for example, at least about 10,000 centipoise, such as at least about 20,000 centipoise or at least about 50,000 centipoise when measured at room temperature. For example, a partially cured binder composition may have a viscosity of at least about 100,000 centipoise, such as about 500,000 centipoise or higher when measured at room temperature. Alternatively, the partially cured binder composition may have a viscosity of less than 10,000 centipoise. The partially cured binder composition typically is a viscous liquid that can flow when temperature and pressure are applied. For example, a pattern may be printed on a partially cured binder composition under pressure. Typically, a partially cured binder composition has a higher viscosity than a binder composition (before curing). In particular, the partially cured binder composition has a viscosity index, defined here as the ratio of the viscosity of the partially cured binder composition at room temperature to the viscosity of the uncured binder composition at room temperature of at least about 1.1. For example, a partially cured binder composition may have a viscosity index of at least about 2.0, for example at least about 5.0, or at least about 10.0. In accordance with a specific embodiment, nanocomposite binders and in particular sol-formed nanocomposite binders are particularly well suited for use in such applications.

Referring again to FIG. 2, it is shown that after partially curing the binder composition 208, a pattern is formed in the partially cured binder material, for example, by rotogravure printing 212. Alternatively, the pattern in the partially cured binder material can be embossed or pressing. Typically, an embossing roller creates the desired surface structure in continuous web processes. The embossing roller used in rotary coating lines is in fact a device with gripping (clamping) rollers, in which one roller is a support roller and the other is an “etched” or embossed roller. The compression of the coated web in this clamping device allows the transfer of a “positive” image of the embossed roller onto the web. Such embossing rollers often have recesses that distinguish them from standard gravure rollers or anilox rollers that are used in the printing industry.

Exemplary drawing tools may be heated. Typically, the pattern forms a repeating pattern of abrasive structures. In accordance with a specific embodiment, the formation of the pattern is carried out without functional powder. Alternatively, the functional powder may be applied on top of the binder composition 208 before or after partial curing of the binder composition 208.

The printed binder composition is then fully cured or cured to achieve the desired mechanical properties. Curing can be done using an energy source, or the binder composition can cure over time. For example, a printed binder composition may be further cured using an energy source 214. An energy source 214 may supply actinic radiation or thermal energy to the binder composition depending on the curing mechanism of the binder composition.

After curing the binder composition, a structured abrasive article is formed. Alternatively, a dimensional coating may be applied over patterned abrasive structures. According to a specific embodiment, the structured abrasive article is wound into a roll 216. In accordance with other embodiments, complete curing can be performed after winding the partially cured abrasive article.

In alternative embodiments, a dimensional coating can be applied over a composition of a binder material and abrasive grains. For example, a dimensional coating may be applied prior to partially curing the binder composition, after partially curing the binder composition, after forming a pattern in the binder composition, or after additional curing of the binder composition. Dimensional coating can be applied, for example, using a roller or by spraying. Depending on the composition of the dimensional coating and the moment of application, the dimensional coating can be cured together with the composition of the binder material or can be cured separately. An oversized coating that contains grinding aids can be applied over the dimensional coating and the cured binder composition and can be cured together with the dimensional coating or can be cured separately.

Specific embodiments of the process described above are preferred for the manufacture of structured abrasive products. Such options make it possible to obtain abrasive products containing binder materials having improved mechanical properties. In particular, some options lead to lower mechanical stresses in the abrasive product and to improved performance of the abrasive product, such as dullness and surface quality. Variants of the method described here above also allow for an increased loading of abrasive grains, which leads to an increase in the service life of the abrasive product and the intensity of stock removal.

EXAMPLES

Examples of compositions of a binder material

Examples 1-5 show exemplary compositions of a binder material that contain polymer structural components and a nanosized powder filler.

Example 1

Exemplary binder compositions contain Nanopox XP 22/0314, which can be purchased from Hanse Chemie, an epoxy resin that contains 3,4-epoxy cyclohexyl methyl-3,4-epoxy cyclohexyl carboxylate and 40 wt.% Colloidal powder filler silica. The binder compositions also contain UVR 6105, which contains 3,4-epoxy cyclohexyl methyl-3,4-epoxy cyclohexyl carboxylate and does not contain a powder filler. The binder compositions further comprise a polyol (4,8-bis (hydroxymethyl) tricyclo (5,2,1,0) decane, a cationic photoinitiator (Chivacure 1176), a radical photoinitiator (Irgacure 2022, which can be purchased from Ciba®), and an acrylate precursor (SR 399, dipentaerythritol pentaacrylate, which can be purchased from Atofina-Sartomer.Exton, PA). Table 1 shows the concentration of the components in the binder compositions.

Example 2

According to another example, the binder compositions contain one polyol selected from the group consisting of Terathane 250, Terafhane 1000, 4,8-bis (hydroxymethyl) tricyclo (5,2,1,0) decane, 2-ethyl-1 , 3-hexanediol and 1,5-pentanediol. The selected polyol is mixed with Nanopox XP 22/0314, Irgacure 2022, Chivacure 1176 and Nanocryl XP 21/0940. Nanocryl XP 21/0940 is a precursor of acrylate (tetraacrylate) which contains 50% by weight of a colloidal silica powder filler, which can be purchased from Hanse Chemie, Berlin. Concentrations are shown in Table 2.

Example 3

In this example, three polyacrylates (Nanocryl XP 21/0940 (tetraacrylate), Nanocryl XP 21/0930 (diacrylate) and Nanocryl 21/0954 (trimethylolpropane ethoxy triacrylate) were tested, each containing 50% by weight of a colloidal silica powder filler and each of which can be purchased from Hanse Chemie). The binder compositions further comprise Nanopox XP 22/0314, 1,5-pentanediol, Irgacure 2022 and Chivacure 1176. The compositions are shown in Table 3.

Table 3 INGREDIENT 3.4
the weight.% 3.5
the weight.% 3.6
the weight.% Nanopox XP 22/0314 77.28 77.28 77.28 1,5-pentanediol 15.46 15.46 15.46 Irgacure 2022 0.52 0.52 0.52 Chivacure 1176 1.50 1.50 1.50 Nanocryl XP 21/0940 5.15 Nanocryl XP 21/0930 5.15 Nanocryl XP 21/0954 5.15 RESULTS Filler,% 33.49 33.49 33.49

Example 4

In accordance with this example, the concentrations of two epoxy components (Nanopox XP 22/0314 and Nanopox 22/0516 (bisphenol A digicidyl ether), each of which can be purchased from Hanse Chemie), having a powder filler in the form of nanosized silica (silicon dioxide) were varied. ) In addition, the oxetane component OXT-212 (3-ethyl-3- (2-ethylhexyloxymethyl) oxetane) was introduced. A polyol (Terathane 250) and a photocatalyst (Chivacure 1176) were also introduced. The compositions are shown in Table 4.

Table 4 INGREDIENT 4.1
the weight.% 4.2
the weight.% 4.3
the weight.% 4.4
the weight.% Nanopox XP 22/0314 67.89 58.19 48.50 38.80 Nanopox XP 22/0516 9.70 19.40 10/29 38.80 Terathane 250 9.70 9.70 9.70 9.70 OHT-212 9.70 9.70 9.70 9.70 Chivacure 1176 2.91 2.91 2.91 2.91 RESULTS Filler,% 04/31 04/31 04/31 04/31

Example 5

In accordance with this example, a sample was prepared using a dimensional coating having a binder composition shown in Table 5. The binder composition includes both nano-sized filler particles obtained from Nanopox 610 additive and micron-sized filler particles (NT-30 and ATH S-3) having an approximate average particle size of 3 μm. NP-30 contains spherical silica particles having an average particle size of about 3 microns. ATH S-3 contains nonspherical particles of aluminum anhydride having an average particle size of about 3 microns. The sample has a Young's modulus of 8.9 GPa (1300 ksi), a tensile strength of 77.2 MPa (11.2 ksi) and an elongation at break of 1%.

Table 5 INGREDIENT The weight.% UVR-6105 0.71 Heloxy 67 6.50 SR-351 2.91 DPHA 1.80 (3-glycidoxypropyl) trimethoxysilane 1.17 Chivacure 184 0.78 NP-30 46.71 ATH S-3 7.78 Nanopox A 610 27.75 Chivacure 1176 3.89 SDA 5688 0.00072

Despite the fact that a preferred embodiment of the invention has been described, it is very clear that it will be modified and supplemented by those skilled in the art that are not beyond the scope of the claims.

Claims (15)

1. A method of forming a structured abrasive product, comprising coating the substrate with a binder composition, partially curing the binder composition, and patterning the surface structure in the partially cured binder composition. 2. The method according to claim 1, which further provides for the complete curing of the composition of the binder material after the formation of said pattern. 3. The method according to claim 2, in which the complete curing of the composition of the binder material after the formation of the aforementioned figure involves exposure to the composition of the binder material using actinic radiation. 4. The method according to claim 2, in which the complete curing of the composition of the binder material after the formation of the aforementioned figure includes thermal curing. 5. The method according to claim 1, which further comprises applying abrasive grains on top of the binder composition. 6. The method according to claim 5, in which the application of abrasive grains is carried out before the partial curing of the composition of the binder material. 7. The method according to claim 5, which further comprises applying a dimensional coating on top of the abrasive grains. 8. The method according to claim 7, in which the application of dimensional coatings is carried out before the partial curing of the composition of the binder material. 9. The method according to claim 1, in which the partial curing of the composition of the binder material involves exposure to the composition of the binder material using actinic radiation. 10. The method according to claim 1, in which the partial curing of the composition of the binder material provides for partial curing of the composition of the binder material to a viscosity index of at least about 1.1. 11. The method according to claim 1, which further provides for mixing the composition of the binder material with abrasive grains to form an abrasive suspension. 12. The method according to claim 1, in which the formation of said pattern is carried out using a heated tool to form a pattern. 13. The method according to claim 1, in which the formation of the said pattern is carried out using rotational intaglio printing. 14. The method according to claim 1, in which the formation of said pattern is carried out by embossing. 15. The method according to claim 1, which further comprises coating the substrate with a compliant coating previously coated with a binder composition.

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