Metal working fluid composition and method of detecting fluid deterioration

Patent metadata

Field	Value
Publication number	US-9778242-B2
Application number	US-201414466320-A
Country	US
Kind code	B2
Filing date	Aug 22, 2014
Priority date	Aug 30, 2013
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A wear-indicating metalworking fluid is provided that includes a lubricant base; and a wear-indicating agent. A method of determining wear in a metalworking fluid includes providing wear-indicating metalworking fluid that contains a lubricant base and a wear indicating agent; and observing the visual appearance of the metalworking fluid. A change in visual appearance of the metalworking fluid when compared to an unused metalworking fluid indicates wear of the metalworking fluid.

First claim

The invention claimed is:

1. A wear-indicating metalworking fluid, comprising:
a lubricant base in a continuous aqueous phase and having an initial pH; and
a first wear-indicating agent dissolved in the lubricant base, the wear-indicating agent changing to a first wear-indicating agent color in response to a change in pH and is colormetrically reversible when the pH is restored to the initial pH; and
a second wear-indicating agent dissolved in the lubricant base, the second wear-indicating agent changing to a second wear-indicating agent color in response to a change in the pH, the second wear-indicating agent color being different than the first wear-indicating agent color and at a different value in the pH relative to the first wear-indicating agent;
wherein the lubricant base and the first and second wear-indicating agents collectively define a fluid color, the first and second wear-indicating agents acting as an efficacy indicator when the pH is in an acceptable operating range with an initial color for the fluid color, and as the pH moves below the accepted operating range of the pH, the fluid color changes from the initial color to other hues when the pH is between 9.00 and 8.32 wherein the fluid color change from the initial color to other hues is due to the color changes of the first wear-indicating agent and when the pH is between about 7.56 and about 8.09 for the metalworking fluid the fluid color is a terminal color, the terminal color is associated with the color changes of the second wear indicating agent and the terminal color is different than the initial color and is also different than the other hues associated with the color changes of the first wear-indicating agent.

2. The fluid of claim 1 wherein the first and second wear indicating agents are each independently selected from the group consisting of: curry powder, thymol blue, pentamethoxy red, tropaeolin OOO, tetrabromophenol blue, bromothymol blue, para-nitrophenol, azolitmin, phenol red, neutral red, cresol red, naphtholphthalein, phenolphthalein, naphtholbenzein, extracts from: blackberries, carrots, cherries, delphinium petals, geranium petals, grapes, grape seeds, horse chestnut leaves, morning glories, pansy petals, petunia petals, primrose, poppy petals, purple peonies, red radish, red cabbage, rhubarb, rose petals, strawberries, tea, turmeric, tulip petals, thyme, violet petals, and vanilla.

3. The fluid of claim 1 wherein upon return of the pH of the metalworking fluid to the initial pH, the visual appearance of the metalworking fluid is restored.

4. The fluid of claim 1 further comprising at least one of: a metal deactivator, a corrosion inhibitor, an antimicrobial agent, an extreme pressure agent, an antifriction agent, a bactericide, an antioxidant, a chelating agent, a pH buffer.

5. A method of determining wear in a metalworking fluid, comprising:
providing wear-indicating metalworking fluid, comprising a lubricant base in a continuous aqueous phase and having an initial pH and a first wear indicating agent dissolved in the lubricant base, the wear-indicating agent changing to a first wear-indicating agent color in response to a change in pH and is colormetrically reversible when the pH is restored to the initial pH; and
providing a second wear-indicating agent dissolved in the lubricant base, the second wear-indicating agent changing to a second wear-indicating agent color in response to a change in the pH, the second wear-indicating agent color being different than the first wear-indicating agent color and at a different value in the pH relative to the first wear-indicating agent;
observing the visual appearance of the metalworking fluid over time, whereby change in visual appearance of the metalworking fluid when compared to an unused metalworking fluid indicates wear of the metalworking fluid; and
wherein the lubricant base and the first and second wear-indicating agents collectively define a fluid color, the first and second wear-indicating agents acting as an efficacy indicator when the pH is in an acceptable operating range with an initial color for the fluid color, and as the pH moves below the accepted operating range of the pH, the fluid color changes from the initial color to other hues when the pH is between 9.00 and 8.32 wherein the fluid color change from the initial color to other hues is due to the color changes of the first wear-indicating agent and when the pH is between about 7.56 and about 8.09 for the metalworking fluid the fluid color is a terminal color, the terminal color is associated with the color changes of the second wear indicating agent and the terminal color is different than the initial color and is also different than the other hues associated with the color changes of the first wear-indicating agent.

6. The fluid of claim 5 wherein the first and second wear indicating agents are each independently selected from the group consisting of: curry powder, thymol blue, pentamethoxy red, tropaeolin OOO, tetrabromophenol blue, bromothymol blue, para-nitrophenol, azolitmin, phenol red, neutral red, cresol red, naphtholphthalein, phenolphthalein, naphtholbenzein, extracts from: blackberries, carrots, cherries, delphinium petals, geranium petals, grapes, grape seeds, horse chestnut leaves, morning glories, pansy petals, petunia petals, primrose, poppy petals, purple peonies, red radish, red cabbage, rhubarb, rose petals, strawberries, tea, turmeric, tulip petals, thyme, violet petals, and vanilla.

Assignees

• Illinois Tool Works
• Illinois Tool Works

Inventors

• Gibbons Emily J
• Badger Ii Steven M
• Hitchcock Leroy N
• Harkey Jacob F

Classifications

• C10N2040/244

  of specific metals · CPC title

• C10M173/00

  Lubricating compositions containing more than 10% water · CPC title

• C10N2040/246

  Iron or steel · CPC title

• C10N2040/245

  Soft metals, e.g. aluminum · CPC title

• C10M171/007

  Coloured or dyes-containing lubricant compositions · CPC title