Friction element

Claim 2

1° A substantially completely cured particulate resin characterised in that it comprises:- (I) a mixture of phenols said mixture comprised of from 25 to 100 mole percent of tri- and/or tetrafunctional phenols and from 0 to 75 mole percent of difunctional phenols; (II) from 1.1 to 3 moles per mole of phenol moiety of an aldehyde containing from 1 to 11 carbon atoms; (III) from 0 to 1 mole per mole of phenol moiety of a reaction promoting compound chosen from the group of the primary, secondary and tertiary amines having up to 10 carbon atoms; and (IV) from 0.05 to 6 weight percent of protective colloid based on the weight of components (I), (II), and (III).

Claim 3

A particulate resin as claimed in claim 1, characterised in that said mixture of phenols (I) is comprised of from 55 to 100 mole percent of tri- and/or tetrafunctional phenol and from 0 to 45 mole percent of difunctional phenol.

Claim 4

A particulate resin as claimed in claim 1 characterised in that said tri- and/or tetrafunctional phenol is monohydroxybenzene.

Claim 5

A particulate resin as claimed in claim 1, characterised in that said difunctional-phenol is p-nonylphenol, p-t-butylphenol, styrenated phenol, linseed oil substituted phenol.or linseed oil-tung oil substituted phenol.

Claim 6

A particulate resin as claimed in any one of the preceding claims, characterised in that said mixture of phenols (I) is comprised of about 78 mole percent phenol and about 22 mole percent p-nonylphenol.

Claim 7

6° A particulate resin as claimed in any one of the preceding claims, characterised in that said aldehyde (II) is present in a concentration of from 1.1 to 2 mole per mole of phenol moiety.

Claim 8

A particulate resin as claimed in any one of the preceding claims, characterised in that said aldehyde (II) is formaldehyde.

Claim 9

A particulate resin as claimed in any one of the preceding claims, characterised in that said reaction promoting compound (III) is present in a concentration of from 0.01 to 0.2 mole per mole of phenol moiety.

Claim 10

A particulate resin as claimed in any one of the preceding claims, characterised in that said reaction promoting compound (III) is hexamethylenetetramine.

Claim 11

A particulate resin as claimed in any one of the preceding claims, characterised in that said protective colloid (IV) is present in a concentration of from 001 to 5 weight percent.

Claim 12

A particulate resin as claimed in any one of the preceding claims, characterised in that said protective colloid (IV) is present in a concentration of from 2 to 3 weight percent.

Claim 13

A particulate resin as claimed in any one of the preceding claims, characterised in that said protective colloid (IV) is a mixture of protective colloids.

Claim 14

A particulate resin as claimed in any one of claims 1 to 11, characterised in that said protective colloid (IV) is gum arabic, jaguar gum or a mixture of gum arabic and jaguar gum.

Claim 15

A friction particle, characterised by comprising a substantially completely cured particulate resin as claimed in any one of the preceding claims.

Claim 16

A friction element characterised by being formulated with from about 1 to about 25 weight percent of a friction particle as claimed in claim 14.

Claim 17

A friction element as claimed in claim 15, characterised by being formulated with from 5 to 15 weight percent of said friction particle.

Claim 18

A process for the production of substantially completely cured resin particles characterised by comprising the steps of: (A) reacting, in an aqueous medium at from about 50°C to about 100°C, (I) a mixture of phenols, said mixture comprised of from 25 to 100 mole percent of tri-and/or tetrafunctional phenols and from 0 to 75 mole percent of difunctional phenols; (II) from 1.1 to 3 moles per mole of phenol moiety of an aldehyde containing from 1 to 11 carbon atoms, (III) from 0.01 to 1 mole per mole of phenol moiety of a reaction promoting compound chosen from the group of alkali and alkaline earth hydroxides and oxides and the primary, secondary and tertiary amines having up to 10 carbon atoms and (IV) from 0005 to 6 weight percent of a protective colloid based on the weight of compounds (I), (II) and (III); for a period of time such that a particulate, heat reactive, and substantially water-insoluble phenolic resin is formed which is dispersed in said. aqueous medium; (B) adding an acid compound to the aqueous dispersion of step (A) in an amount such that the pH of the aqueous dispersion is from 0 to 4; and (C) substantially completely curing the resin particles.

Claim 19

A process for the production of substantially completely cured resin particles characterised by comprising the steps of: (A) reacting, in an aqueous medium at from about 50°C to about 100°C, (I) a mixture of phenols, said mixture comprised of from 25 to 100 mole percent of tri-and/or tetrafunctional phenols and from 0 to 75 mole percent of difunctional phenols; (II) from 1.1 to 3 moles per mole of phenol moiety of an aldehyde containing from 1 to 11 carbon atoms, (III) from 0.01 to 1 mole per mole of phenol moiety of a reaction promoting compound chosen from the group of alkali and alkaline earth hydroxides and oxides and the primary, secondary and tertiary amines having up to 10 carbon atoms and (IV) from 0005 to 6 weight percent of a protective colloid based on the weight of compounds (I), (II) and (III); for a period of time such that a particulate, heat reactive, and substantially water-insoluble phenolic resin is formed which is dispersed in said. aqueous medium; (B) adding an acid compound to the aqueous dispersion of step (A) in an amount such that the pH of the aqueous dispersion is from 0 to 4; and (C) substantially completely curing the resin particles.

Claim 20

A process as claimed in claim 17, characterised in that the reaction temperature of step (A) is from 90°C to 100°C.

Claim 21

A process as claimed in claim 17 or 18, characterised in that the reaction temperature of step (A) is the temperature of atmospheric reflux.

Claim 22

20 0 A process as claimed in any one of claims 17 to 19, characterised in that in step (B) the acidic compound is added in an amount such that the pH of the aqueous dispersion is from 1 to 3.

Claim 23

A process as claimed in any one of claims 17 to 20, characterised in that the acidic compound of step (B) is sulfuric acid.

Claim 24

22 0 A process as claimed in any one of claims 17 to 21, characterised in that the curing step (0) is accomplished by the application of external heat.