Silicone-based defoaming agent composition

Abstract

Provided is a silicone defoamer composition that not only has exceptional defoaming speed, but experiences no loss in defoaming performance even under repeated or prolonged use. The present invention is a silicone defoamer composition that contains a polyoxyalkylene-group-containing polyorganosiloxane polymer crosslinked material, said silicone defoamer composition containing partial structure (I) – R1–(R2 2SiO)d–R1– (where R1 is a C2-20 alkylene group that bonds with a silicon atom on a polysiloxane chain, R2 is a univalent hydrocarbon group, and d is a number within the range of 200–1000) and partial structure (II) –(CeH2e)–O–(EO)x–(PO)y–(BO)z–R3 (where: EO is an ethyleneoxy unit expressed by C2H4O; PO is a propyleneoxy unit expressed by C3H6O; BO is a butyleneoxy unit expressed by C4H8O; the left-end single bond bonds with a silicon atom on the polysiloxane chain; R3 is a hydrogen atom, an alkyl group, an aryl group, or an acyl group; e is a number within the range of 2–10; x+y+z is a number within the range of 40–100; x is a number within the range of 15–50; y is a number within the range of 15–50; and z is a number within the range of 0–50).

Description

Technical Field

[0001] The present invention relates to a silicone-based antifoaming agent composition.

Background Art

[0002] In industrial processes such as the process of treating or processing a liquid, an antifoaming agent is used to suppress the generation of foam. In particular, silicone-based antifoaming agents are widely used because they are chemically stable and have little influence on the object to which they are applied.

[0003] Various types of silicone-based antifoaming agents have been proposed. For example, Patent Document 1 describes a silicone antifoaming agent composition containing a polyorganosiloxane having a specific general formula and having a viscosity at 25°C of 20 cs to 100,000 cs, a silane, and a fine powder filler. Further, Patent Document 2 describes a silicone antifoaming agent composition characterized by containing a first component composed of a silicone-based antifoaming agent and a second component composed of a cross-linked product of a polyorganosiloxane polymer having a polyoxyalkylene group.

[0004] However, conventional antifoaming agent compositions may have a slow defoaming rate and insufficient initial defoaming performance. In addition, when repeatedly used or used for a relatively long time, the defoaming performance may decrease. Therefore, there has been a demand for the development of an antifoaming agent composition having a fast defoaming rate, no decrease in defoaming performance even when repeatedly used, and excellent persistence of defoaming properties. Furthermore, when the second component specifically described in Patent Document 2 is used, the dilution stability of the antifoaming agent composition is not sufficient, and further improvement is required.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made to solve the above problems of the prior art, and an object thereof is to provide a silicone defoaming agent composition that not only has excellent defoaming speed, but also does not deteriorate in defoaming performance even when repeatedly used or used for a long time, and further has excellent dilution stability.

Means for Solving the Problems

[0007] As a result of intensive studies on the above problems, the present inventors have reached the present invention. That is, the object of the present invention is, Partial structure (I): -R 1 -(R 2 2SiO) d -R 1 - (In the formula, R 1 is an alkylene group having 2 to 20 carbon atoms bonded to a silicon atom on the polysiloxane chain, R 2 is a monovalent hydrocarbon group, and d is a number in the range of 200 to 1000), and Partial structure (II): -(C e H 2e )-O-(EO) x -(PO) y -(BO) z -R 3 (In the formula, EO is an ethyleneoxy unit represented by C2H4O, PO is a propyleneoxy unit represented by C3H6O, BO is a butyleneoxy unit represented by C4H8O, The single bond at the left end is bonded to a silicon atom on the polysiloxane chain, and R 3 is a hydrogen atom, an alkyl group, an aryl group or an acyl group, e is a number in the range of 2 to 10, x + y + z is a number in the range of 40 to 100, x is a number in the range of 15 to 50, y is a number in the range of 15 to 50, and z is a number in the range of 0 to 50) This is achieved by a silicone defoamer composition containing a crosslinked polyorganosiloxane polymer having a polyoxyalkylene group.

[0008] In the aforementioned substructure (I), d is preferably a number in the range of 250 to 900.

[0009] In the aforementioned substructure (II), it is preferable that x is a number in the range of 20 to 40, y is a number in the range of 20 to 40, and z is 0.

[0010] The crosslinked polyorganosiloxane polymer having the polyoxyalkylene group has the following structural formula: [ka] (In the formula, a is a number between 10 and 200, b+c is a number in the range of 2 and 50, b and c are each a number of 1 or more, EO and PO are the same groups as described above, R is a hydrogen atom, alkyl group, aryl group or acyl group, and d, x and y are the same numbers as defined in substructures (I) and (II) above.) It is preferable that it be represented as follows:

[0011] The silicone-based defoaming agent composition of the present invention, (A) An essentially hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mPa·s at 25°C: 20 to 80 parts by mass, (B) Hydrophobic organopolysiloxane or cyclic organopolysiloxane containing silanol groups at least at both ends: 20 to 80 parts by mass, (C) Silane or silane condensate: 1 to 10 parts by mass, and (D) Specific surface area of ​​50 m 2 Fine silica powder of 2-10 parts by mass (1g or more): Preferably, the oil compound for silicone-based defoaming agents contains (A) and (B), with the total of (A) and (B) being 100 parts by mass.

[0012] (B) component is, (B1) A hydrophobic organopolysiloxane containing silanol groups at both ends with a pressure of 1,000 to 10,000,000 mPa·s, and (B2) Hydrophobic organopolysiloxanes or cyclic siloxanes containing silanol groups at both ends with a pressure of 1 to 1,000 mPa·s It is preferable that it includes.

[0013] The molar ratio of component (B) to the total amount of component (A) is preferably 0.7 or higher.

[0014] The molar ratio of component (B1) to the total amount of component (A) is preferably 0.2 or greater.

[0015] The oil compound for the silicone-based defoaming agent is preferably emulsified with a crosslinked polyorganosiloxane polymer having a polyoxyalkylene group.

[0016] The silicone-based defoaming agent oil compound preferably has a viscosity of 10,000 to 1,000,000 mPa·s at 25°C.

[0017] The particle size of the emulsion in the silicone defoaming agent composition of the present invention is preferably 0.1 to 10 μm.

[0018] The silicone defoaming agent composition of the present invention is preferably used in metalworking fluids. [Effects of the Invention]

[0019] The silicone defoaming agent composition of the present invention provides an antifoaming agent composition that not only exhibits excellent initial defoaming performance due to its superior defoaming speed, but also maintains its defoaming performance even after repeated use or prolonged use. [Modes for carrying out the invention]

[0020] The silicone defoaming agent composition of the present invention is Substructure (I):-R1 -(R 2 2SiO) d -R 1 - (In the formula, R 1 R is an alkylene group with 2 to 20 carbon atoms bonded to a silicon atom on a polysiloxane chain, 2 (where is a monovalent hydrocarbon group and d is a number in the range of 200 to 1000), and Substructure (II):-(C e H 2e )-O-(EO) x -(PO) y -(BO) z -R 3 (In the formula, EO is an ethylene oxy unit represented by C2H4O, PO is a propyleneoxy unit represented by C3H6O, BO is a butylene oxy unit represented by C4H8O, The single bond on the far left is bonded to a silicon atom on the polysiloxane chain, R 3 (where x is a hydrogen atom, alkyl group, aryl group, or acyl group, e is a number in the range of 2 to 10, x + y + z is a number in the range of 40 to 100, x is a number in the range of 15 to 50, y is a number in the range of 15 to 50, and z is a number in the range of 0 to 50) It contains a crosslinked polyorganosiloxane polymer having a polyoxyalkylene group.

[0021] In substructure (I), R 1 This is an alkylene group having 2 to 20 carbon atoms bonded to a silicon atom on a polysiloxane chain. The alkylene group having 2 to 20 carbon atoms may be linear or branched, and examples include methylmethylene group, ethylene group, methylethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, and octylene group.

[0022] In substructure (I), R 2 R is a monovalent hydrocarbon group. 2It is preferable that the group is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and these may be the same or different. 2 Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as styryl and α-methylstyryl groups; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, or hydroxyl groups.

[0023] In substructure (I), d is a number in the range of 200 to 1000, preferably in the range of 250 to 900, and more preferably in the range of 270 to 800. In the present invention, by selecting the above range for d and combining it with a specific range of chain lengths for (EO)(PO) in substructure (II) described later, the defoaming performance and dilution stability of the defoaming agent emulsified by a polyorganosiloxane polymer crosslinked product having a polyoxyalkylene group are greatly improved.

[0024] Substructure (II) is one of the characteristic structures of the present invention, and is a polyoxyalkylene group bonded to a silicon atom via an alkylene group having e carbon atoms, and always contains a certain number of ethylene oxy units and a certain number of propylene oxy units, and optionally may also contain butylene oxy units. More specifically, in substructure (II), EO is an ethylene oxy unit represented by C2H4O, and an ethylene oxy unit represented by CH2CH2O is preferred. PO is a propylene oxy unit represented by C3H6O, and may be either a propylene oxy unit represented by CH2CH(CH3)O or a propylene oxy unit represented by CH2CH2CH2O, and is preferred. BO is a butylene oxy unit represented by C4H8O, and like the propylene oxy unit, may be a linear or branched butylene structure. 3 The atoms are a hydrogen atom, an alkyl group, an aryl group, or an acyl group. The alkyl group may be an unsubstituted or substituted alkyl group having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl groups. The aryl group may be an aryl group having 6 to 20 carbon atoms, and examples include phenyl and tolyl groups. The acyl group may be an acyl group having 2 to 12 carbon atoms, and examples include acetyl, propionyl, and benzoyl groups.

[0025] In substructure (II), e is a number in the range of 2 to 10, preferably a number in the range of 3 to 8. e H 2e An alkylene group having e carbon atoms, preferably an alkylene group having 3 to 8 carbon atoms, may have a partially branched structure or a linear structure.

[0026] In substructure (II), x+y+z is a number in the range of 40 to 100, x is a number in the range of 15 to 50, y is a number in the range of 15 to 50, and z is a number in the range of 0 to 50. Preferably, x is a number in the range of 20 to 45, y is a number in the range of 20 to 45, and z is a number in the range of 0 to 25. More preferably, x is a number in the range of 20 to 40, y is a number in the range of 20 to 40, and z is 0. In the present invention, by selecting the above ranges for x, y, and x+y (z may be 0) and combining them with a polysiloxane structure having a chain length in a specific range in the aforementioned substructure (I), the defoaming performance and dilution stability of the defoaming agent emulsified with a polyorganosiloxane polymer crosslinked product having a polyoxyalkylene group are greatly improved.

[0027] A crosslinked polyorganosiloxane polymer having a polyoxyalkylene group, containing substructure (I) and substructure (II), has the following structural formula: [ka] It is preferable that it be represented as follows:

[0028] In the formula, A is a substructure (I): -R 1 -(R 2 2SiO) d -R 1 - and R 4 ~R 7 and R 9 ~R 12 Each of these is independently a monovalent hydrocarbon group, and R 8 and R 13 is a substructure (II):-(C e H 2e )-O-(EO) x -(PO) y -(BO) z -R 3 The preferred range for the variables a to c, which represent the number of repetitions, is as follows:

[0029] a: 1 ≤ a ≤ 1000, preferably 1 ≤ a ≤ 500, most preferably 1 ≤ a ≤ 250 b: 0 < b ≤ 30, preferably 0 < b ≤ 20, most preferably 0 < b ≤ 15 c: 1 ≤ c ≤ 20, preferably 1 ≤ c ≤ 15, most preferably 0 ≤ c ≤ 10

[0030] R 4 ~R 7 and R 9 ~R 12 The monovalent hydrocarbon groups of R and ~R are preferably unsubstituted or substituted monovalent hydrocarbon groups having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and these may be the same or different. The monovalent hydrocarbon group of R 2 , specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, etc., cycloalkyl groups such as cyclohexyl group, alkenyl groups such as vinyl group, allyl group, etc., aryl groups such as phenyl group, tolyl group, etc., aralkyl groups such as styryl group, α-methylstyryl group, etc., or a part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, hydroxyl groups, such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, cyanoethyl group, 3-aminopropyl group, N-(β-aminoethyl)-γ-aminopropyl group, etc. An alkyl group is preferred, and a methyl group is particularly preferred.

[0031] The polyorganosiloxane polymer crosslink having a polyoxyalkylene group and containing substructure (I) and substructure (II) has the following structural formula:

Chemical formula

[0032] In the above structural formula, R is R in substructure (II). 3 The group is similar to the above, and is a hydrogen atom, an alkyl group, an aryl group, or an acyl group. The alkyl group may be an unsubstituted or substituted alkyl group having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and examples include the methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, and octadecyl group. The aryl group may be an aryl group having 6 to 20 carbon atoms, and examples include the phenyl group and the tolyl group. The acyl group may be an acyl group having 2 to 12 carbon atoms, and examples include the acetyl group, propionyl group, and benzoyl group.

[0033] The crosslinked polyorganosiloxane polymer having polyoxyalkylene groups contained in the silicone defoaming agent composition of the present invention is obtained by the following reaction.

[0034] Addition reaction between component (a) and component (b) below (a) Component: Polyorganosiloxane having two or more Si-H groups in the side chain of one molecule (b) Components: Polyorganosiloxanes with vinyl or alkenyl groups sealed at both ends.

[0035] Specifically, a crosslinked polyorganosiloxane polymer having polyoxyalkylene groups can be produced by (i) hydrosilylation of a polyorganosiloxane having two or more Si-H groups in the side chains of one molecule and a polyorganosiloxane with both ends sealed with vinyl or alkenyl groups, using a platinum catalyst in isopropyl alcohol or toluene to obtain a crosslinked siloxane; (ii) reacting the product obtained in step (i) with an allyl polyether, also using a platinum catalyst, in isopropyl alcohol or toluene to obtain a crosslinked polyether-modified silicone; and (iii) removing the reaction solvent by heating under reduced pressure to 100-150°C. Steps (i) and (ii) can be carried out at a temperature of 80-100°C.

[0036] The crosslinked polyorganosiloxane polymer having polyoxyalkylene groups contained in the silicone defoaming agent composition of the present invention is characterized by the formation of a three-dimensional crosslinked structure by the reaction of component (a) and component (b) above, and the addition reaction between their Si-H groups and vinyl groups or alkenyl groups, and by having fluidity. Here, a three-dimensional crosslinked structure refers to a structure in which two or more polyorganosiloxane molecules are linked via two or more branched structures.

[0037] The method for obtaining a specific siloxane crosslinked product having the above characteristics is not limited to this, and can be used by either obtaining a crosslinked product of a polyorganosiloxane polymer and adding polyoxyalkylene groups thereto, or by obtaining a linear polyorganosiloxane to which polyoxyalkylene groups have been added and crosslinking it.

[0038] The crosslinked polyorganosiloxane polymer having polyoxyalkylene groups contained in the silicone defoaming agent composition of the present invention preferably has a viscosity of 100 to 100,000 mPa·s at 25°C.

[0039] The silicone defoaming agent composition of the present invention is (A) An essentially hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mPa·s at 25°C: 20 to 80 parts by mass, (B) Hydrophobic organopolysiloxane or cyclic organopolysiloxane containing silanol groups at least at both ends: 20 to 80 parts by mass, (C) Silane or silane condensate: 1 to 10 parts by mass, and (D) Specific surface area of ​​50 m 2 Fine silica powder of 2-10 parts by mass (1g or more): Preferably, the oil compound for silicone-based defoaming agents contains (A) and (B), with the total of (A) and (B) being 100 parts by mass.

[0040] [An essentially hydrophobic organopolysiloxane with a viscosity of 10 to 100,000 mPa·s at 25°C] The organopolysiloxane of component (A) is essentially hydrophobic. Here, essentially hydrophobic means that even if some of the functional groups contain hydrophilic groups, the organopolysiloxane as a whole exhibits hydrophobicity.

[0041] The essentially hydrophobic organopolysiloxane (A) may be linear or branched, but the one shown in the following average composition formula (I) is preferred. R 1 g SiO (4-g) / 2 (I)

[0042] In the above equation (I), R 1 R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and these may be the same or different. 1Specifically, monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as styryl and α-methylstyryl groups; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, or hydroxyl groups. However, from the standpoint of antifoaming properties and economic efficiency, all R 1 It is preferable that 80 mol% or more, and particularly 90 mol% or more, of the compound consists of methyl groups.

[0043] g is a positive number such that 1.9 ≤ g ≤ 2.2, preferably 1.95 ≤ g ≤ 2.15.

[0044] Furthermore, the terminal end of organopolysiloxane is R 1 Even when blocked by a triorganosilyl group represented by 3Si-, (HO)R 1 It may be encapsulated with a diorganohydroxysilyl group represented by 2Si-.

[0045] (A) The viscosity of an essentially hydrophobic organopolysiloxane measured at 25°C using a rotational viscometer is 10 to 100,000 mPa·s, and may be 100 to 100,000 mPa·s, preferably 2,500 to 50,000 mPa·s, more preferably 3,000 to 45,000 mPa·s, and most preferably 4,000 to 40,000 mPa·s, from the viewpoint of defoaming rate and persistence of defoaming performance. Below the lower limit, the defoaming performance may decrease, and above the upper limit, the viscosity of the silicone-based defoaming agent oil compound may increase, resulting in poor workability.

[0046] Component (A) is usually produced by ring-opening polymerization of a cyclic low molecular weight siloxane such as octamethylcyclotetrasiloxane using a catalyst. However, since the polymerized product contains the cyclic low molecular weight siloxane that was the raw material, it is preferable to use a product obtained by distilling off the siloxane while passing an inert gas through during the reaction under heating and reduced pressure.

[0047] (A) Examples of specific structural representations of component (A) include, but are not limited to, those shown below. In the following formulas, Me, Vi, and Ph represent a methyl group, a vinyl group, and a phenyl group, respectively.

[0048] [ka] (In the equation, n ≥ 10 and o ≥ 1.)

[0049] Component (A) may be an essentially hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mPa·s at 25°C, used alone or as a mixture of two or more.

[0050] [Hydrophobic organopolysiloxanes or cyclic organopolysiloxanes containing silanol groups at least at both ends] The organopolysiloxane of component (B) is hydrophobic or cyclic, containing silanol groups at least at both ends. Here, hydrophobic means that, as with component (A), the organopolysiloxane as a whole is hydrophobic even if some of its functional groups contain hydrophilic groups.

[0051] The hydrophobic organopolysiloxane (B), which contains silanol groups at least at both ends, may be linear or branched, but the one shown in the following average composition formula (II) is preferred. R 2 p (R 3 O) q SiO (4-p-q) / 2 (II)

[0052] In the above equation (II), R2 R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and these may be the same or different. 2 Specifically, examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, and octadecyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as styryl and α-methylstyryl groups; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, or hydroxyl groups. 3 These are hydrogen atoms or monovalent hydrocarbon groups having 1 to 18 carbon atoms, particularly 1 to 15 carbon atoms, and these may be the same or different.

[0053] The average value of p+q is preferably 1.9 to 2.2, where q is a sufficient value to provide silanol groups at both ends, and at least one OH group is present at each end.

[0054] The structure of cyclic siloxanes is not particularly limited, but examples include those represented by the following average empirical formula (III).

[0055] [ka]

[0056] In the above equation (III), R 4 R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 15 carbon atoms, especially 1 to 10 carbon atoms, and these may be the same or different. 4Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, and tetradecyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as styryl and α-methylstyryl groups; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, or hydroxyl groups.

[0057] r is preferably an integer between 3 and 20, and more preferably an integer between 3 and 10.

[0058] In particular, component (B) is (B1) A hydrophobic organopolysiloxane containing silanol groups at both ends with a pressure of 1,000 to 10,000,000 mPa·s, and (B2) Hydrophobic organopolysiloxanes or cyclic siloxanes containing silanol groups at both ends with a pressure of 1 to 1,000 mPa·s It is preferable that it includes.

[0059] (B1) The viscosity of a hydrophobic organopolysiloxane containing silanol groups at both ends, as measured by a rotational viscometer at 25°C, is preferably 2,000 to 1,000,000 mPa·s, and more preferably 5,000 to 100,000 mPa·s. Also, (B2) The viscosity of a hydrophobic organopolysiloxane containing silanol groups at both ends, as measured by a rotational viscometer at 25°C, is preferably 5 to 500 mPa·s, and more preferably 10 to 100 mPa·s.

[0060] Component (B) can be used in an amount of 20 to 80 parts by mass relative to 20 to 80 parts by mass of component (A), with the total of component (A) and component (B) being 100 parts by mass. Preferably, component (B) can be used in an amount of 30 to 70 parts by mass relative to 30 to 70 parts by mass of component (A), with the total of component (A) and component (B) being 100 parts by mass.

[0061] The molar ratio of component (B) to the total amount of component (A) is preferably 0.7 or higher, more preferably 0.75 or higher, and most preferably 0.8 or higher.

[0062] The molar ratio of component (B1) to the total amount of component (A) is preferably 0.2 or higher, more preferably 0.25 or higher, and most preferably 0.3 or higher.

[0063] [Silane or silane condensates] The structure of component (C) silane or silane condensate is not particularly limited, but examples include those shown in the following average composition formula (IV).

[0064] R 5 s SiX 4-s (IV)

[0065] In the above equation (IV), R 5 R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 15 carbon atoms, especially 1 to 10 carbon atoms, and these may be the same or different. 5Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, and tetradecyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as styryl and α-methylstyryl groups; or chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, cyanoethyl, 3-aminopropyl, and N-(β-aminoethyl)-γ-aminopropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms, cyano groups, amino groups, or hydroxyl groups.

[0066] X is a hydrolyzable group, examples of which include -OR', -OYOR', -NR'R'', -ON=CR'R'', -OOCR', -OCR'=CR'R'', -ONR'R'', and -NR'-CO-R''. R' and R'' represent hydrogen or a monovalent hydrocarbon group, and as a monovalent hydrocarbon group, R 5 Similar groups can be cited. Y is an unsubstituted or substituted divalent hydrocarbon group having 1 to 15 carbon atoms, particularly 1 to 10 carbon atoms, such as an alkylene group. Note that R' and R'' in -ON=CR'R'' may be bonded to each other to form the following structure.

[0067] [ka]

[0068] In the formula, Z is an unsubstituted or substituted divalent hydrocarbon group having 1 to 15 carbon atoms, particularly 1 to 10 carbon atoms, such as an alkylene group.

[0069] The mean value of s is less than or equal to 1, therefore, R 5 This means that it is either SiX3 or SiX4 alone, or a mixture thereof.

[0070] The silane component (C) is a compound well known to those skilled in the art, and examples include the following compounds.

[0071] CH3Si(OCH3)3, CH3Si(OC2H5)3, CH2=CHSi(OCH3)3, C6H5Si(OC2H5)3, Si(OC2H5)4, Si(OC3H7)4, CH2=CHSi(OC2H5)3, Si(OC2H4OC2H5)4, CH3Si(N(C4H9)2)3, CH3Si(ON=C(CH3)2)3, CH3Si(OOCCH3)3, CH3Si(OC(CH3)=CH2)3, and CH3Si(ON(C2H5)2)3.

[0072] Furthermore, the silane in component (C) may be a partially hydrolyzed condensate thereof.

[0073] Component (C) may be the silane or silane condensate described above, either alone or as a mixture of two or more.

[0074] Component (C) can be used in amounts of 1 to 10 parts by mass per 100 parts by mass of the total of components (A) and (B), preferably in amounts of 2 to 5 parts by mass.

[0075] [Specific surface area is 50m 2 [fine silica powder of / g or more] (D) The fine silica powder of component (D) is preferably hydrophilic silica such as fumed silica or precipitated silica, and these can be used alone or in combination of two or more types. The specific surface area (BET method) of the fine silica powder is 50 m². 2 The amount is 100-700 m or more. 2 / g, and more preferably 150-500m 2 It is / g. The specific surface area is 50m². 2 By setting the value to 1 / g or higher, desirable defoaming performance can be obtained.

[0076] Examples of commercially available component (D) that can be used in the present invention include AEROSIL (registered trademark) 300 (hydrophilic fumed silica having a BET specific surface area of 300 m 2 / g) available from Nippon Aerosil Co., Ltd., AEROSIL (registered trademark) 200 (hydrophilic fumed silica having a BET specific surface area of 200 m 2 / g), and NIPSIL (registered trademark) L-250 (hydrophilic precipitated silica having a BET specific surface area of 170 m 2 / g) available from Tosoh Silica Corporation.

[0077] The proportion of component (D) is 2 to 10 parts by mass, preferably 3 to 5 parts by mass, based on 100 parts by mass in total of components (A) and (B). If it is less than 2 parts by mass, sufficient defoaming performance cannot be obtained, and if it exceeds 10 parts by mass, the viscosity of the oil compound for silicone-based defoamer increases and the workability deteriorates.

[0078] [Method for Producing Oil Compound for Silicone-Based Defoamer] The oil compound for silicone-based defoamer is (1) a step of kneading all or part of the components of the oil compound for silicone-based defoamer, (2) a step of heat-treating the kneaded product obtained in step (1) at 50 to 300 °C, (3) a step of adding an alkali catalyst or an acid catalyst to the kneaded product obtained in step (2) and kneading, (4) a step of adding, if present, the remaining components of the oil compound for silicone-based defoamer to the kneaded product obtained in step (3) and kneading, and (5) a step of neutralizing the catalyst in the kneaded product obtained in step (4) can be produced by a method including these steps.

[0079] The alkali catalyst or acid catalyst used in step (3) of the method for producing an oil compound for silicone-based defoaming agents is not particularly limited. As an alkali catalyst, known alkali catalysts used in the equilibrium reaction of polysiloxanes, such as oxides, hydroxides, alkoxides, or silanolates of alkali metals or alkaline earth metals, can be used, and potassium silanolate and potassium hydroxide are preferred. As an acid catalyst, examples include organic acids such as acetic acid, butyric acid, maleic acid, and citric acid, and inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid. As a catalyst, an alkali catalyst is preferred over an acid catalyst.

[0080] The amount of alkaline catalyst or acid catalyst used is 0.001 to 5 parts by mass per 100 parts by mass of component (A), preferably 0.01 to 5 parts by mass, more preferably 0.01 to 3 parts by mass, and even more preferably 0.05 to 3 parts by mass. Amounts less than 0.001 parts by mass do not provide sufficient catalytic effect, and amounts exceeding 5 parts by mass do not significantly improve the catalytic effect, making it cost-inefficient.

[0081] In the method for producing an oil compound for silicone-based defoaming agents, the neutralizing agent used in step (5) for the alkaline catalyst can be hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, or a carboxylic acid that is solid at room temperature, preferably a carboxylic acid that is solid at room temperature. Examples of carboxylic acids that are solid at room temperature include monocarboxylic acids such as benzoic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, and tricarboxylic acids such as citric acid, isocitric acid, oxalosuccinic acid, and aconitic acid. Among these, succinic acid is preferred because it has a small acid dissociation constant, is a strong acid, and is readily available. Furthermore, as a neutralizing agent for the acid catalyst, oxides, hydroxides, alkoxides, or silanolates of alkali metals or alkaline earth metals can be used, preferably potassium silanolate and potassium hydroxide. The amount of neutralizing agent used should be sufficient to neutralize the alkali catalyst or acid catalyst.

[0082] In step (1) of the method for manufacturing an oil compound for silicone-based defoaming agents, components (A) to (C) or components (A) to (D) are kneaded at a temperature of preferably 100°C or lower, more preferably 80°C or lower. There is no need to heat from the outside, and the kneading can be done at room temperature (e.g., 10 to 30°C). It is preferable to adjust the temperature, which rises due to the heat generated in the system by frictional resistance during kneading, to 100°C or lower, and especially 80°C or lower. The processing time for step (1) depends greatly on the kneading equipment and scale and cannot be specified in general terms, but it is usually 0.1 to 3 hours, and especially 0.5 to 2 hours is desirable.

[0083] In the method for manufacturing an oil compound for silicone-based defoaming agents, step (2) involves heat-treating the mixture obtained in step (1) at 50 to 300°C, preferably 70 to 200°C, preferably while mixing. By setting the heat treatment temperature within the above range, excellent defoaming performance can be obtained. The processing time for step (2) depends greatly on the mixing equipment and scale and cannot be specified in general terms, but it is usually 0.1 to 4 hours, and particularly preferably 0.5 to 2 hours.

[0084] Step (3) in the method for producing an oil compound for silicone-based defoaming agents involves adding an alkaline catalyst or an acidic catalyst to the mixture obtained in step (2) and mixing it to make the oil compound system alkaline or acidic. Step (3) can be carried out at 10 to 300°C, preferably 20 to 200°C. The processing time for step (3) also depends greatly on the mixing equipment and scale and cannot be specified in general terms, but it is usually 0.05 to 3 hours, and particularly preferably 0.1 to 2 hours.

[0085] Step (4) in the method for manufacturing an oil compound for silicone-based defoaming agents is a step in which the remaining components of the oil compound for silicone-based defoaming agents, if present, such as a portion of component (B) and component (D), are added to the mixture obtained in step (3) and mixed, and this step is for immobilizing the reactive groups of each component on the surface of fine silica powder. Step (4) can be carried out at 50 to 300°C, preferably 70 to 200°C. The processing time for step (4) also depends greatly on the mixing equipment and scale and cannot be specified in general terms, but it is usually 0.05 to 6 hours, and particularly preferably 0.1 to 4 hours.

[0086] Step (5) in the method for manufacturing an oil compound for silicone-based defoaming agents is a step of neutralizing the catalyst in the compound obtained in step (4), and can be carried out at 10 to 300°C, preferably 20 to 200°C. The processing time for step (3) also depends greatly on the mixing equipment and scale and cannot be specified in general terms, but it is usually 0.1 to 4 hours, and particularly 0.5 to 3 hours is desirable.

[0087] In the method for manufacturing an oil compound for silicone-based defoaming agents, examples of kneaders used for mixing include, but are not limited to, planetary mixers, kneaders, pressure kneaders, twin-screw kneaders, intensive mixers, adi-homogenized mixers, dispersers, and planetary dispersers. These kneaders can be used in any of steps (1) to (5).

[0088] The viscosity of the final silicone-based defoaming agent oil compound, measured at 25°C using a rotational viscometer, is 10,000 to 1,000,000 mPa·s, preferably 20,000 to 100,000 mPa·s, and more preferably 30,000 to 50,000 mPa·s.

[0089] The silicone defoaming agent composition of the present invention is preferably emulsified by a polyorganosiloxane polymer crosslinked product having a polyoxyalkylene group containing partial structures (I) and (II) with an oil compound for silicone defoaming agents. The viscosity of the defoaming agent may be appropriately designed according to its emulsification conditions, viscosity, etc.

[0090] The polyorganosiloxane polymer crosslinked product having a polyoxyalkylene group containing partial structures (I) and (II) may be used alone or as a mixture of two or more. However, its content is preferably 5 to 95% by mass of the whole silicone defoaming agent composition, more preferably 10 to 70% by mass. If the content is too large, the defoaming performance of the defoaming agent composition may be inferior. In addition, when formulating, it can be an effective amount, but it is preferably formulated at 20% by mass or more.

[0091] Also, in the silicone defoaming agent composition, HO-[PO] 35 -H, HO-[PO] 70 -H, HO-[EO]4-[PO] 30 -H, HO-[EO] 25 -[PO] 35 -H, HO-[PO] 30 -H, CH2=CHCH2O-[EO] 32 -[PO]8-H, CH2=CHCH2O-[EO] 22 -[PO] 22 -C4H9, CH2=CHCH2O-[EO] 10 -CH3 (In the above formulas, EO is an ethyleneoxy unit represented by C2H4O, and an ethyleneoxy unit represented by CH2CH2O is preferred. PO is a propyleneoxy unit represented by C3H6O, and may be either a propyleneoxy unit represented by CH2CH(CH3)O or CH2CH2CH2O, and is preferred.) Nonionic surfactants such as polyoxyalkylene polymers as exemplified above, sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene oxypropylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene propylene glycol fatty acid esters, polyoxyethylene castor oil, and polyoxyethylene hydrogenated castor oil may also be used.

[0092] Polyoxyalkylene polymers are added to improve the dispersibility of oil compounds for silicone-based defoamers. They may be used alone or as a mixture of two or more polymers, but their content is preferably 0 to 95% by mass of the total silicone defoamer composition, and more preferably 0 to 70% by mass. If the content is too high, the defoaming performance of the defoamer composition may be poor. When added, the amount can be an effective amount, but it is preferable to add 20% by mass or more.

[0093] Furthermore, nonionic surfactants are added to improve the dispersibility of the oil compound for silicone-based defoamers. They may be used alone or as a mixture of two or more types, but their content is preferably 0 to 95% by mass of the total silicone defoamer composition, and more preferably 0 to 70% by mass. If the content is too high, the defoaming performance as a defoamer may be poor. When adding them, the amount can be an effective amount, but it is preferable to add 20% by mass or more.

[0094] Furthermore, the content of the silicone-based defoaming agent oil compound is preferably 5 to 80% by mass of the total silicone defoaming agent composition, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass. If the content of the silicone-based defoaming agent oil compound is too low, the defoaming performance of the defoaming agent composition may be poor, and if it is too high, the objective of improving the dispersibility of the silicone-based defoaming agent oil compound may not be satisfied.

[0095] In a silicone defoaming agent composition, it is necessary to add water to emulsify each component, such as a silicone-based defoaming agent oil compound, a crosslinked polyorganosiloxane polymer having a polyoxyalkylene group, a polyoxyalkylene polymer, and a nonionic surfactant. The amount of water added is the remainder relative to the total content of each component, preferably 50 to 2,000 parts by mass, more preferably 80 to 400 parts by mass, per 100 parts by mass of the total of each component.

[0096] The silicone defoaming agent composition can be prepared by mixing predetermined amounts of each component other than water, and stirring and emulsifying the mixture using a known mixing and dispersing machine such as a homomixer, homogenizer, or colloid mill while heating as needed. In particular, a method is preferred in which predetermined amounts of each component other than water are uniformly mixed and dispersed, then a portion of the water is added, stirred and emulsified, and then the remaining water is added and uniformly stirred and mixed.

[0097] Furthermore, small amounts of preservatives and disinfectants may be optionally added to the silicone defoaming agent composition for preservative purposes. Specific examples of these preservatives and disinfectants include sodium hypochlorite, sorbic acid, potassium sorbate, salicylic acid, sodium salicylate, benzoic acid, sodium benzoate, parabens, and isothiazolino compounds. The amount of these added is preferably 0 to 0.5% by mass of the total silicone defoaming agent composition, and particularly preferably 0.005 to 0.5% by mass.

[0098] Furthermore, a small amount of thickener may be optionally added to the silicone defoaming agent composition for the purpose of increasing thickness. Specific examples of such thickeners include polyacrylic acid, sodium polyacrylate, acrylic acid / methacrylic acid copolymer, sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, xanthan gum, and guar gum. The amount of this thickener added is preferably 0 to 1.0% by mass of the total silicone defoaming agent composition, and particularly preferably 0.01 to 0.5% by mass.

[0099] The particle size of the emulsion of the silicone defoamer composition is preferably 0.1 to 10 μm, more preferably 0.5 to 8 μm, and most preferably 0.7 to 6 μm. The particle size of the emulsion is the median diameter (particle size corresponding to 50% of the cumulative distribution, based on the number of particles) and can be measured by a laser diffraction particle size analyzer.

[0100] The silicone defoaming agent composition of the present invention is preferably used in metalworking oils such as cutting oils, grinding oils, plastic working oils, heat treatment oils, and electrical discharge machining oils; engine oils such as gasoline engine oils, diesel engine oils, and gas engine oils; automotive gear oils such as automatic transmission oils and manual transmission oils; industrial gear oils; turbine oils; bearing oils; and rust-preventive oils. [Examples]

[0101] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0102] [Viscosity measurement] Measurements were taken using a rotational viscometer (manufactured by Shibaura Semtec Co., Ltd., product name: Bismetron VDA-2) at a rotational speed of 12 rpm and rotor No. 4.

[0103] [Measurement of average particle size] The self-emulsifying compound was dispersed in water and measured using a laser diffraction particle size analyzer (Beckman Coulter LS-230). The median diameter (the particle size corresponding to 50% of the cumulative distribution, the 50% particle size) was defined as the average particle size.

[0104] [Evaluation of defoaming performance] For the evaluation of defoaming performance, NS Cut S-20 (soluble water-soluble cutting fluid, 20% active ingredient, manufactured by NS Chemical Co., Ltd.) was used as the foaming solution, diluted four times with tap water heated to 23°C. The viscosity of the foaming solution at this time was 3.5 mPa·s. The defoaming agent to be evaluated was added at a solid content of 25 ppm.

[0105] 400g of the above effervescent solution was added to a 1000mL tall beaker, and the mixture was stirred at 8000rpm for 10 minutes using a homomixer (Primix Corporation, HV-M type) to induce foaming. The baffle height was set to 10cm from the bottom of the homomixer and 11cm from the bottom of the flask. After stirring stopped, a foam layer formed on top of the liquid, and the change in the thickness of this foam layer over time was measured. The time it took for the foam layer thickness to decrease to 4mm was defined as t (minutes), and the results were evaluated as shown in the table below.

[0106] [Table 1]

[0107] To confirm the persistence of the defoaming performance, this operation was repeated four times and the defoaming performance was evaluated each time.

[0108] [Manufacturing Example 1] 12.59 g of component (a) of the linear organopolysiloxane represented by chemical formula 1 below (j=110, k=10) and 4.57 g of component (b) of the linear organopolysiloxane represented by chemical formula 2 below (m=290) were heated and mixed at 60°C. After homogeneous mixing, 0.002 g of chloroplatinic acid and 0.15 g of isopropyl alcohol were added in a mixture, and the mixture was reacted at 60°C for 3 hours to obtain a clear, viscous liquid. To the obtained viscous liquid, 0.01 g of sodium acetate and 82.84 g of allyl polyether with terminal hydrogen groups of ethylene oxide: 22 moles - propylene oxide: 22 moles were added, and the mixture was reacted at 80-90°C for 3 hours. After the reaction, the isopropyl alcohol in the viscous liquid was removed by heating at 80°C under reduced pressure for 1 hour. A brown, viscous liquid was obtained.

[0109] [ka]

[0110] [Manufacturing Example 2] 12.20 g of component (a) of the linear organopolysiloxane represented by chemical formula 1 (j=110, k=10), 7.51 g of component (b) of the linear organopolysiloxane represented by chemical formula 2 (m=493), and 20.00 g of toluene were heated and mixed at 60°C. After homogeneous mixing, 0.002 g of chloroplatinic acid and 0.15 g of isopropyl alcohol were added in a mixture, and the mixture was reacted at 60°C for 3 hours to obtain a clear, viscous liquid. 0.01 g of sodium acetate and 80.29 g of allyl polyether with terminal hydrogen groups of ethylene oxide: 22 moles - propylene oxide: 22 moles were added to the obtained viscous liquid, and the mixture was reacted at 80-90°C for 3 hours. After the reaction, isopropyl alcohol and toluene in the viscous liquid were removed by heating at 100°C under reduced pressure for 3 hours. A brown, viscous liquid was obtained.

[0111] [Manufacturing Example 3] 11.71 g of component (a) of the linear organopolysiloxane represented by chemical formula 1 (j=110, k=10), 11.19 g of component (b) of the linear organopolysiloxane represented by chemical formula 2 (m=766), and 12.82 g of toluene were heated and mixed at 60°C. After homogeneous mixing, 0.002 g of chloroplatinic acid and 0.15 g of isopropyl alcohol were added in a mixture, and the mixture was reacted at 60°C for 3 hours to obtain a clear, viscous liquid. 0.01 g of sodium acetate and 77.10 g of allyl polyether with terminal hydrogen groups of ethylene oxide: 22 moles - propylene oxide: 22 moles were added to the obtained viscous liquid, and the mixture was reacted at 80-90°C for 3 hours. After the reaction, isopropyl alcohol and toluene in the viscous liquid were removed by heating at 100°C under reduced pressure for 3 hours. A brown, viscous liquid was obtained.

[0112] [Comparative Manufacturing Example 1] 21.46 g of component (a) of the linear organopolysiloxane represented by chemical formula 1 with j=110 and k=10, and 4.58 g of component (b) of the linear organopolysiloxane represented by chemical formula 2 with m=179, were heated and mixed at 60°C. After homogeneous mixing, 0.002 g of chloroplatinic acid and 0.15 g of isopropyl alcohol were added in a mixture, and the mixture was reacted at 60°C for 3 hours to obtain a clear, viscous liquid. To the obtained viscous liquid, 0.01 g of sodium acetate and 73.80 g of allyl polyether with terminal hydrogen groups of ethylene oxide: 18 moles - propylene oxide: 18 moles were added, and the mixture was reacted at 80-90°C for 3 hours. After the reaction, the isopropyl alcohol in the viscous liquid was removed by heating at 80°C under reduced pressure for 1 hour. A brown, viscous liquid was obtained.

[0113] [Comparative Manufacturing Example 2] 12.81 g of component (a) of the linear organopolysiloxane represented by chemical formula 1 with j=110 and k=10, and 2.88 g of component (b) of the linear organopolysiloxane represented by chemical formula 2 with m=179, were heated and mixed at 60°C. After homogeneous mixing, 0.002 g of chloroplatinic acid and 0.15 g of isopropyl alcohol were added in a mixture, and the mixture was reacted at 60°C for 3 hours to obtain a clear, viscous liquid. To the obtained viscous liquid, 0.01 g of sodium acetate and 84.31 g of allyl polyether with terminal hydrogen groups of ethylene oxide: 22 moles - propylene oxide: 22 moles were added, and the mixture was reacted at 80-90°C for 3 hours. After the reaction, the isopropyl alcohol in the viscous liquid was removed by heating at 80°C under reduced pressure for 1 hour. A brown, viscous liquid was obtained.

[0114] [Table 2]

[0115] [Oil compound for silicone-based defoamers #1] Silicone-based defoaming agent oil compound #1 was prepared by the following method: In a 1 L three-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas injection, 59.10 parts by mass of trimethylsilyl-terminated polydimethylsiloxane (viscosity 1,000 mPa·s at 25°C), 30.60 parts by mass of silanol-terminated polydimethylsiloxane (viscosity 12,500 mPa·s at 25°C), and 3.06 parts by mass of polyethyl silicate ("Silbond 50," manufactured by Evonik) were added, and the mixture was heated to 110°C while stirring. At 110°C, a mixture of 1.54 parts by mass of potassium dimethylsilanolate catalyst, 5.15 parts by mass of trimethylsilyl group-terminated polydimethylsiloxane (viscosity 1,000 mPa·s at 25°C), and 0.08 parts by mass of ethanol, which had been mixed beforehand, was added, and stirring was continued at 110°C for 30 minutes. Next, silica ("Aerosil 200" with a specific surface area of ​​200 m²) was added. 2A mixture of polyether-modified silicone 501W (manufactured by Evonik) was added and heated at 110°C for 30 minutes, then uniformly dispersed using a homomixer. A mixture of 0.02 parts by mass of polyether-modified silicone 501W and 0.13 parts by mass of deionized water was added and stirred. Then, 5.15 parts by mass of silanol-terminated polydimethylsiloxane (viscosity 40 mPa·s at 25°C) was added and the temperature was raised to 190°C. 1.05 parts by mass of potassium dimethylsilanolate catalyst was added and the mixture was reacted at 190°C for 1 hour. The resulting reaction product was neutralized, and 0.02 parts by mass of polyether-modified silicone 501W and 1.83 parts by mass of deionized water were added and uniformly mixed to obtain a silicone-based defoaming oil compound. The entire process was carried out under nitrogen gas purging. The viscosity of the obtained silicone-based defoaming oil compound was 15,000 mPa·s.

[0116] [Example 1] After mixing 45 parts by mass of a polyorganosiloxane polymer crosslinked product having polyoxyalkylene groups, produced in Production Examples 1 to 3 and Comparative Production Examples 1 and 2, with 25 parts by mass of EOPOEO copolymer (Adeka Pluronic® L-31), 30 parts by mass of the above-mentioned silicone-based defoaming agent oil compound #1 was added, and a self-emulsifying defoaming agent composition was obtained using a homomixer. The diluted appearance of the obtained defoaming agent composition was a slightly bluish emulsion.

[0117] [Examples 2 and 3, and Comparative Examples 1 and 2] An antifoaming agent composition was prepared in the same procedure as in Example 1, except that the crosslinked polyorganosiloxane polymer having polyoxyalkylene groups was changed as shown in Table 3. The diluted appearance of the obtained antifoaming agent composition was a slightly bluish emulsion.

[0118] [Table 3]

[0119] As can be seen from Table 3, which summarizes the results of each example and comparative example, when a silicone defoaming agent composition containing a polyorganosiloxane polymer crosslinked with polyoxyalkylene groups containing partial structures (I) and (II) of the present invention was used, it was found that the defoaming rate was fast from the first test, the defoaming performance was excellent, and practical defoaming performance could be obtained even after repeating the test four times. On the other hand, in the comparative example with a small number of repeating siloxane units in partial structure (I), a sufficient defoaming rate was not obtained, and it was found that the defoaming performance decreased with repeated tests. From these results, it is thought that the polyorganosiloxane polymer crosslinked with polyoxyalkylene groups shown in the examples improves the dilution and shear force performance of the defoaming agent, and improvement in defoaming persistence can be expected.

[0120] [Oil compound for silicone-based defoamers #2] In a 1 L three-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas injection, 59.1 parts by mass of trimethylsilyl-terminated polydimethylsiloxane (viscosity 5,000 mPa·s at 25°C), 30.60 parts by mass of silanol-terminated polydimethylsiloxane (viscosity 12,500 mPa·s at 25°C), and 3.06 parts by mass of polyethyl silicate ("Silbond 50," manufactured by Evonik) were added, and the mixture was heated to 110°C while stirring. At 110°C, a pre-mixed mixture of 1.54 parts by mass of potassium dimethylsilanolate catalyst, 5.15 parts by mass of trimethylsilyl-terminated polydimethylsiloxane (viscosity 5,000 mPa·s at 25°C), and 0.08 parts by mass of ethanol was added, and stirring was continued at 110°C for 30 minutes. Next, silica ("Aerosil 200" specific surface area 200m²) 2A mixture of polyether-modified silicone 501W (manufactured by Evonik) was added and heated at 110°C for 30 minutes, then uniformly dispersed using a homomixer. A mixture of 0.1 parts by mass of polyether-modified silicone 501W and 0.13 parts by mass of deionized water was added and stirred. Then, 5.15 parts by mass of silanol-terminated polydimethylsiloxane (viscosity 40 mPa·s at 25°C) was added and the temperature was raised to 190°C. 1.25 parts by mass of potassium dimethylsilanolate catalyst was added and the mixture was reacted at 190°C for 1 hour. The resulting reaction product was neutralized, and 0.02 parts by mass of polyether-modified silicone 501W and 2.19 parts by mass of deionized water were added and uniformly mixed to obtain a silicone-based defoaming oil compound. The entire process was carried out under nitrogen gas purging. The viscosity of the obtained silicone-based defoaming oil compound was 33,500 mPa·s.

[0121] [Examples 4-6] As shown in Table 4, the defoaming agent compositions of Examples 4 to 6 were prepared using the same procedure as in Example 1, except that the above-mentioned silicone-based defoaming agent oil compound #2 was used instead of silicone-based defoaming agent oil compound #1, and the evaluation results are shown in Table 4.

[0122] [Table 4]

[0123] When the polyorganosiloxane polymer crosslinked according to the present invention is used in combination with silicone-based defoaming agent oil compound #2 using trimethylsilyl group-terminated polydimethylsiloxane (viscosity of 5,000 mPa·s at 25°C) having a slightly longer chain length, as shown in Table 4 (Examples 4-6), in addition to improved dilution stability against shear stress, the defoaming persistence is further enhanced. Therefore, it is expected that even better defoaming performance can be achieved by using the defoaming agent oil compound according to the present invention in combination with a polyorganosiloxane polymer crosslinked with polyoxyalkylene groups having an optimized structure.

Claims

1. A silicone defoaming agent composition comprising a crosslinked polyorganosiloxane polymer having a polyoxyalkylene group and an oil compound for silicone-based defoaming agents, The aforementioned polyorganosiloxane polymer crosslinked product is Partial construction (I): -R １ - (R) ２ ２ SiO) ｄ -R １ - (In the formula, R １ R is an alkylene group having 2 to 20 carbon atoms bonded to a silicon atom on a polysiloxane chain, ２ (where is a monovalent hydrocarbon group and d is a number in the range of 250 to 900), and Partial construction (II): -(C) ｅ H ２ｅ )-O-(EO) ｘ - (PO) ｙ - (BO) ｚ -R ３ (In the formula, EO is C ２ H ４ It is an ethylene oxy unit represented by O, PO is C ３ H ６ It is a propyleneoxy unit represented by O, BO is C ４ H ８ It is a butylene oxy unit represented by O, The single bond on the far left is bonded to a silicon atom on the polysiloxane chain, R ３ (where is a hydrogen atom, an alkyl group, an aryl group, or an acyl group, e is a number in the range of 2 to 10, x + y + z is a number in the range of 40 to 100, x is a number in the range of 20 to 40, y is a number in the range of 20 to 40, and z is 0) It contains, The aforementioned silicone-based defoaming agent oil compound is (A) An essentially hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mPa·s at 25°C: 20 to 80 parts by mass, (B) Hydrophobic organopolysiloxane or cyclic organopolysiloxane containing silanol groups at least at both ends: 20 to 80 parts by mass, (C) Silane or silane condensate: 1 to 10 parts by mass, and (D) Fine silica powder with a specific surface area of ​​50 m² / g or more: 2 to 10 parts by mass It includes, and the total of (A) and (B) is 100 parts by mass. Silicone defoaming agent composition.

2. The silicone defoaming agent composition according to Claim 1, further comprising 80 to 400 parts by mass of water per 100 parts by mass of the total of each component.

3. The aforementioned crosslinked polyorganosiloxane polymer having a polyoxyalkylene group has the following structural formula: 【Chemistry 1】 (In the formula, a is a number between 10 and 200, b + c is a number in the range of 2 and 50, b and c are each a number of 1 or more, EO and PO are the same groups as described above, R is a hydrogen atom, alkyl group, aryl group or acyl group, and d, x and y are the same numbers as defined in substructures (I) and (II) above.) A silicone defoaming agent composition according to claim 1 or 2, as represented by the above.

4. (B) Component is (B1) A hydrophobic organopolysiloxane containing silanol groups at both ends, with a pressure of 1,000 to 10,000,000 mPa·s, and (B2) Hydrophobic organopolysiloxanes or cyclic siloxanes containing silanol groups at both ends, with a pressure of 1 to 1000 mPa·s. A silicone defoaming agent composition according to any one of claims 1 to 3, comprising:

5. A silicone defoaming agent composition according to any one of claims 1 to 4, wherein the molar ratio of component (B) to the total amount of component (A) and component (B) is 0.7 or more.

6. The silicone defoaming agent composition according to claim 4, wherein the molar ratio of component (B1) to the total amount of component (A) and component (B1) is 0.2 or more.

7. The silicone defoaming agent composition according to any one of claims 1 to 6, wherein the silicone-based defoaming agent oil compound is emulsified with a polyorganosiloxane polymer crosslinked product having a polyoxyalkylene group.

8. The silicone defoaming agent composition according to any one of claims 1 to 7, wherein the viscosity of the silicone-based defoaming agent oil compound at 25°C is 10,000 to 1,000,000 mPa·s.

9. The silicone defoaming agent composition according to claim 7, wherein the particle size of the emulsion is 0.1 to 10 μm.

10. A silicone defoaming agent composition according to any one of claims 1 to 9, for use in metalworking oils.

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