Abstract: The present invention provides a water-soluble lubricating oil including a water-soluble base (A) and a corrosion inhibitor (B). The water-soluble base (A) contains at least one polyether (A1). A 0.1% by weight aqueous solution of the water-soluble lubricating oil has a surface tension of 31 mN/m or higher.

Abstract: A water-soluble cutting fluid for slicing silicon ingots is characterized in that it includes a monoprotic or diprotic aliphatic carboxylic acid (A) having a carbon number (including the carbon in the carbonyl group) of 4˜10, and either a polyprotic organic acid (B) with ?pKa of 0.9˜2.3 as defined by the following formula (1) or a salt (BA) of said organic acid (B) as essential components: ?pKa=(pKa2)?(pKa1)??(1) wherein the dissociation stage, at which the organic acid (B) denoted as n-protic acid HnA, becomes Hn-1A+H+ is numbered 1 with an acid dissociation constant expressed as pKa1, and the dissociation stage at which the organic acid (B) becomes Hn-2A+H+ is numbered as 2 with an acid dissociation constant expressed as pKa2.

Abstract: The present invention provides a water-soluble lubricating oil including a water-soluble base (A) and a corrosion inhibitor (B). The water-soluble base (A) contains at least one polyether (A1). A 0.1% by weight aqueous solution of the water-soluble lubricating oil has a surface tension of 31 mN/m or higher.

Abstract: A water-soluble cutting fluid for slicing silicon ingots is characterized in that it includes a monoprotic or diprotic aliphatic carboxylic acid (A) having a carbon number (including the carbon in the carbonyl group) of 4˜10, and either a polyprotic organic acid (B) with ?pKa of 0.9˜2.3 as defined by the following formula (1) or a salt (BA) of said organic acid (B) as essential components: ?pKa=(pKa2)?(pKa1) ??(1) wherein the dissociation stage, at which the organic acid (B) denoted as n-protic acid HnA, becomes Hn-1A+H+ is numbered 1 with an acid dissociation constant expressed as pKa1, and the dissociation stage at which the organic acid (B) becomes Hn-2A+H+ is numbered as 2 with an acid dissociation constant expressed as pKa2.

Abstract: A straw with a mouthpiece includes a straw main body having openings at both ends thereof and a mouthpiece integrally connected with a tip portion of the straw main body. The tip portion of the straw main body is provided with at least one engaging aperture penetrating a peripheral wall constituting the straw main body, and the mouthpiece is provided with at least one engaging protrusion inwardly protruded from an inner peripheral surface thereof. The engaging protrusion is engaged with the engaging aperture, whereby the mouthpiece is integrally connected with the straw main body so as not to be detached therefrom.

Abstract: A straw with a mouthpiece includes a straw main body having openings at both ends thereof and a mouthpiece integrally connected with a tip portion of the straw main body. The tip portion of the straw main body is provided with at least one engaging aperture penetrating a peripheral wall constituting the straw main body, and the mouthpiece is provided with at least one engaging protrusion inwardly protruded from an inner peripheral surface thereof. The engaging protrusion is engaged with the engaging aperture, whereby the mouthpiece is integrally connected with the straw main body so as not to be detached therefrom.