Patent GB-963334-A (GB)
Title: Phenolic resin bonded grinding wheels
IPC: C08L61/10
Filed: 1960-07-21
Abstract: The surface of abrasive grains is coated with a polysiloxane in order to facilitate bonding of the grains with a phenolic resin.  The polysiloxane is derived from a silane of formula: <FORM:0963334/C3/1> in which R is reactive with phenolic resin and is amino-substituted aryl or alkyl, an alkyl group carrying a vicinal epoxy grouping, substituted phenoxy, formyl, an alkyl, aryl or furyl radical carrying an aldehyde grouping, or hydroxy phenyl; C is a hydrolisable group, e.g. alkoxy or halogen; and A and B are the same or different and are any of the groups listed for R or C, or are non-hydrolysable groups non-reactive towards phenolic resins.  The grains may be coated directly with pure silicone or treated with a solution or suspension of the polysiloxane and the vehicle removed by drying, or the polysiloxane may be added to a liquid used to coat the abrasive before bonding, e.g. a plasticizer or a liquid phenolic resin which aids bonding of the phenolic resin bond to the coated grains.  In typical examples (I) Aluminium oxide grit was treated with a solution of gamma-amino propyl triethoxy silane in aqueous ethanol, dried, wetted with furfural and treated with powdered two-stage phenolic resin, cryolite and lime. Neutral anthracene oil was added to complete wetting of the bonding resin, and the mixture moulded to form grinding wheels.  (VIII) The silicone concentrate was mixed with liquid phenolic resin before application to the abrasive grains. Two-stage powdered phenolic resin, cryolite and neutral anthracene oil was added to the treated grains and the mixture moulded to form abrasive wheels. (X) The gamma-amino-propyl triethoxy silane was mixed with some vinyl triethoxy silane before use.  (XI) An allyl trichlorosilane-resorcinol reaction product in xylene was used to treat the abrasive grains.  Silicon carbide is used in place of aluminium oxide in some examples.  Conventional fillers and additives may be included in the abrasive compositions according to the examples.ALSO:The surface of abrasive grains is coated with a polysiloxane in order to facilitate bonding of the grains with a phenolic resin. The polysiloxane is derived from a silane of formula <FORM:0963334/C4-C5/1> in which R is reactive with phenolic resin and is amino-substituted aryl or alkyl, an alkyl group carrying a vicinal epoxy grouping, substituted phenoxy, formyl, an alkyl, aryl or furyl radical carrying an aldehyde grouping, or hydroxy phenyl; C is a hydrolysable group, e.g. alkoxy or halogen; and A and B are the same or different and are any of the groups listed for R or C, or are non-hydrolysable groups non-reactive towards phenolic resins. The grains may be coated directly with pure silicone or treated with a solution or suspension of the polysiloxane and the vehicle removed by drying, or the polysiloxane may be added to a liquid used to coat the abrasive before bonding, e.g. a plasticizer or a liquid phenolic resin which aids bonding of the phenolic resin bond to the coated grains.  In typical Example I aluminium oxide grit was treated with a solution of gamma-amino propyl triethoxy silane in aqueous ethanol, dried, wetted with furfural and treated with powdered two-stage phenolic resin, cryolite and lime.  Neutral anthracene oil was added to complete wetting of the bonding resin, and the mixture moulded to form grinding wheels. VIII.  The silicone concentrate was mixed with liquid phenolic resin before application to the abrasive grains. Two-stage powdered phenolic resin, cryolite and neutral anthracene oil was added to the treated grains and the mixture moulded to form abrasive wheels. X.  The gamma-aminopropyl triethoxy silane was mixed with some vinyl triethoxy silane before use. XI.  An allyl trichlorosilane-resorcinol reaction product in xylene was used to treat the abrasive grains.  Silicon carbide is used in place of aluminium oxide in some examples.  Conventional fillers and additives may be included in the abrasive compositions according to the examples.