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EP0257757A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Coated abrasive having radiation curable binder

Assignee: 3M Co
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Filing: 1987-07-10
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Granted: —
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Expires: 2007-07-10
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Abstract

Abstract This invention relates to coated abrasive products, and, in particular, to coated abrasive products having a radiation-curable binder. Radiation-curable coated abrasives heretofore known exhibit the shortcoming of poor adhesion of abrasive granules to the backing because the binder does not cure in areas where the granules screen out radiation, unless high dosages of ionizing radiation are employed. High dosages of radiation can adversely affect the backing. The poor adhesion of the abrasive granules results in a large loss of abrasive granules, i.e. "shelling", from the backing upon flexing and grinding. Attempts to improve the adhesion of the abrasive granules by curing by ionizing radiation, e.g., electron beam, through the backside of the backing often leads to degradation of the backing. This invention provides a coated abrasive product and a process for producing same. The coated abrasive product comprises a backing, a make coat, and a size coat, and may contain an optional backsize coat, or any combination of said optional coats, in which at least one coat is formed from a composition curable by electromagnetic radiation comprising: (A) a curable portion containing both ethylenically unsaturated groups and 1,2-epoxide groups, which groups can be in the same compound or in different compounds, and (b) a photoinitiator portion. The photoinitiator portion activates both free-radical and cationic curing mechanisms. The use of the radiation curable composition of this invention overcomes the problem of poor adhesion of abrasive granules resulting from incomplete cure of the binder by combining a cationic curing mechanism with a free-radical curing mechanism.

Inventors

  • 👤 Michael L. C/O Minnesota Mining And Tumey
  • 👤 Donna W. C/O Minnesota Mining And Bange
  • 👤 Aida F. C/O Minnesota Mining And Robbins

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 19:33
CPC Classifications
C; C08; C08J; C08J5/00; C08G; C08G59/00; C08G59/18; C08G59/68; B; B24; B24D; B24D3/00; B24D3/001; B24D3/002; B24D3/02; B24D3/20; B24D3/28; B24D3/34; B24D3/342; B24D3/344; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/31504; Y10T428/31511

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 118 words
A coated abrasive product comprising abrasive granules which are supported on and adherently bonded to at least one major surface of a backing by a resinous binder material, said resinous binder material formed from a composition curable by electromagnetic radiation comprising ethylenically-unsaturated groups and 1,2-epoxide groups, and a photoinitiator portion, in an amount sufficient to cure the composition, comprising at least one polymerization photoinitiator selected from the group consisting of (1) salts having an onium cation and a halogen-containing anion of a metal or metalloid, and (2) a mixture of (a) at least one salt having an organometallic complex cation and a halogen-containing complex anion of a metal or metalloid, and (b) at least one free-radical polymerization initiator.
Claim 2
Dependent Claim 118 words
A coated abrasive product comprising abrasive granules which are supported on and adherently bonded to at least one major surface of a backing by a resinous binder material, said resinous binder material formed from a composition curable by electromagnetic radiation comprising ethylenically-unsaturated groups and 1,2-epoxide groups, and a photoinitiator portion, in an amount sufficient to cure the composition, comprising at least one polymerization photoinitiator selected from the group consisting of (1) salts having an onium cation and a halogen-containing anion of a metal or metalloid, and (2) a mixture of (a) at least one salt having an organometallic complex cation and a halogen-containing complex anion of a metal or metalloid, and (b) at least one free-radical polymerization initiator.
Claim 3
Dependent Claim 69 words
A coated abrasive product according to claim 1 which comprises a backing, a make coat, a layer of abrasive grains, and a size coat wherein optionally said backing has at least one of a saturant coat, a presize coat, or a backsize coat, wherein at least one of the make coat, size coat, saturant coat, presize coat or backsize coat is formed from said composition curable by electromagnetic radiation.
Claim 4
Dependent Claim 143 words
A coated abrasive product according to either of claims 1 and 2 wherein said composition curable by electromagnetic radiation comprises (A) at least one bireactive compound containing at least one ethylenically-unsaturated group and at least one 1,2-­epoxide group. (B) at least one ethylenically-unsaturated compound and at least one compound containing at least one 1,2-epoxide group. (C) at least one bireactive compound containing at least one ethylenically-unsaturated group and at least one 1,2-­epoxide group, and at least one ethylenically-unsaturated compound, (D) at least one bireactive compound containing at least one ethylenically-unsaturated group and at least one 1,2-epoxide group, and at least one compound containing at least one 1,2-epoxide group, and (E) at least one bireactive compound containing at least one ethylenically-unsaturated group and at least one 1,2-­epoxide group, at least one ethylenically-unsaturated compound, and at least one compound containing at least one 1,2-epoxide group.
Claim 5
Dependent Claim 28 words
A product according to any one of claims 1 to 3 wherein the etylenically-unsaturated groups are provided by esters of aliphatic hydroxy group-containing compounds and unsaturated carboxylic acids.
Claim 6
Dependent Claim 20 words
A product according to claim 4 wherein said ethylenically-unsaturated groups are provided by an ester of acrylic or methacrylic acid.
Claim 7
Dependent Claim 43 words
A product according to any one of claims 1 to 3 wherein the ethylenically unsaturated groups are provided by compounds selected from ethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, diacrylate of bisphenol A, ethoxylated diacrylate of bisphenol A, aliphatic urethane acrylate, and N-vinyl-2-­pyrrolidone.
Claim 8
Dependent Claim 38 words
A product according to any one of claims 1 to 6 wherein the 1,2-epoxide groups are provided by compounds selected from 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane­carboxylate, 3,4-epoxy-2-methylcyclohexylmethyl 3,4-epoxy-2-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2,2-bis[4-(2,3-epoxypropoxy)phenyl])propane, butyl glycidyl ether, neopentylglycol diglycidyl ether, and resorcinol diglycidyl ether.
Claim 9
Dependent Claim 48 words
A product according to any one of claims 1 to 3 wherein the ethylenically-unsaturated groups and 1,2-epoxide groups are provided by bireactive compounds which are the reaction product of compounds having at least two 1,2-epoxide groups with a stoichiometric deficiency of an ethylenically-unsaturated compound that contains active hydrogen.
Claim 10
Dependent Claim 57 words
A product according to claim 8 wherein said bireactive compounds are the reaction product of 0.4 to 0.6 weight equivalents of acrylic acid and one mole of a member selected from diglycidyl ether of bisphenol A, diglycidyl ether of 1,4-butanediol, polyglycidyl ether of phenol-formaldehyde novolac, polyglycidyl ether of cresol-formaldehyde novolac, diglycidyl terephthalate, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane­carboxylate, and bis(3,4-epoxy-6-methylcyclohexyl)methyl adipate.
Claim 11
Dependent Claim 19 words
A product according to any one of claims 1 to 9 further containing a latent thermally activated polymerization initiator.
Claim 12
Dependent Claim 35 words
A product according to any one of claims 1 to 10 wherein said composition comprises at least 0.2 equivalent of ethylenically-­unsaturated group and at least 0,05 equivalent of 1,2-epoxide group per 100 grams of composition.
Claim 13
Dependent Claim 32 words
A coated abrasive product according to any one of claims 1 to 11 wherein the total amount of photoinitiator ranges from 0.05 to 10 parts by weight of said radiation curable composition.
Claim 14
Dependent Claim 31 words
A coated abrasive product according to any one of claims 1 to 12 wherein at least one of said make coat and said size coat is formed from a phenolic resin.
Claim 15
Dependent Claim 112 words
Method of preparing the coated abrasive product of claim 2 comprising the steps of (1) providing a backing optionally having at least one of a saturant coat, a presize coat, or a backsize coat, (2) applying a make coat over said backing, (3) applying a layer of abrasive grains over said make coat, (4) applying a size coat over said layer of abrasive grains, (5) curing at least one of said saturant coat, presize coat, backsize coat, make coat or size coat by means of electromagnetic radiation, the saturant coat, presize coat, or backsize coat being cured before application of the make coat (6) curing said make coat and said size coat.

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