Organopolysiloxane and surface treatment agent

Abstract

This organopolysiloxane having a structural unit ratio represented by formula (1) has excellent heat resistance and can impart corrosion resistance to a metal surface. (1): (SiO4 / 2)a(R1SiO3 / 2)b1(R2SiO3 / 2)b2(R1 2SiO2 / 2)c1 (R1R2SiO2 / 2)c2(R1 3SiO1 / 2)d1(R1 2R2SiO1 / 2)d2(R3O1 / 2)e [R1 represents a hydrogen atom or a monovalent hydrocarbon group having 1-10 carbon atoms, R2 represents a group represented by -(CH2)m-X (X represents a monovalent group having a nitrogen-containing heterocyclic ring, and m represents an integer of 1-20), R3 represents a hydrogen atom or a methyl, ethyl, n-propyl, i-propyl, or acetyl group, a, b1, b2, c1, c2, d1, and d2 represent numbers that satisfy 0≤a<1, 0≤b1<1, 0<b2≤1, 0≤c1<1, 0≤c2<1, 0≤d1<1, 0≤d2<1, and a+b1+b2+c1+c2+d1+d2=1, and e represents a number that satisfies 0≤e≤2.]

Description

Organopolysiloxane and surface treatment agent

[0001] The present invention relates to an organopolysiloxane and a surface treatment agent.

[0002] BACKGROUND ART For the purpose of preventing metal rust, development of chromium-free (non-chromate) metal surface treatment agents has been promoted as an alternative to chromium-based surface treatment agents such as toxic chromate and chromate phosphate.

[0003] Patent Documents 1 and 2 propose the use of imidazole ring-containing organosilicon compounds and benzotriazole ring-containing organosilicon compounds as surface treatment agents for metals and the like, but the corrosion resistance, adhesion, etc., of these compounds are insufficient.

[0004] Furthermore, Patent Document 3 discloses a metal surface treatment agent containing a silane coupling agent having a benzotriazole ring and a urea bond. The benzotriazole ring and the urea bond form a coordinate bond to form a sparingly soluble complex, thereby exhibiting rust prevention properties, and the hydrolyzable silyl group provides excellent processing adhesion. However, there is room for improvement in heat resistance, corrosion resistance, and adhesiveness.

[0005] JP 2000-297093 A JP 6-279463 A JP 2016-79130 A

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an organopolysiloxane that has excellent heat resistance and is capable of imparting corrosion resistance to metal surfaces, and a surface treatment agent that uses this organopolysiloxane.

[0007] As a result of extensive research conducted by the present inventors to achieve the above object, they discovered that a specific organopolysiloxane has excellent heat resistance and can impart corrosion resistance to metal surfaces, and thus completed the present invention.

[0008] That is, the present invention provides: 1. an organopolysiloxane having a constitutional unit ratio represented by the following formula (1), (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b1 (R 2 SiO3 / 2 ) b2 (R 1 2SiO 2 / 2 ) c1 (R 1 R 2 SiO 2 / 2 ) c2 (R 1 3SiO 1 / 2 ) d1 (R 1 2nd Race 2 SiO 1 / 2 ) d2 (R 3 O 1 / 2 ) e (1) [wherein, R 1 are each independently a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently -(CH2) m -X (X represents a monovalent group having a nitrogen-containing heterocycle, and m is an integer of 1 to 20), and R 3 represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or an acetyl group, and a, b1, b2, c1, c2, d1, and d2 are numbers that satisfy 0≦a<1, 0≦b1<1, 0<b2≦1, 0≦c1<1, 0≦c2<1, 0≦d1<1, and 0≦d2<1, and a+b1+b2+c1+c2+d1+d2=1, and e is a number that satisfies 0≦e≦2. 2. An organopolysiloxane of 1, wherein X is a group selected from the following formulas (2) to (6): (In the formula, R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and the wavy line portion represents a bond to an adjacent atom.) 3. An organopolysiloxane of 1, wherein b2 is a number satisfying 0.4≦b2≦1; 4. A surface treatment agent containing any of the organopolysiloxanes of 1 to 3; and 5. An article treated with any of the organopolysiloxanes of 1 to 3.

[0009] The organopolysiloxane of the present invention has a structure in which a nitrogen-containing heterocycle is bonded to a silicon atom via an alkylene group, and therefore exhibits good rust-preventing performance due to the formation of coordinate bonds on the metal surface, and also has excellent heat resistance. Because the organopolysiloxane of the present invention has these characteristics and does not contain chromium, it can be suitably used as a surface treatment agent for various materials, such as a surface treatment agent for metals.

[0010] The present invention will be described in detail below. [Organopolysiloxane] The organopolysiloxane of the present invention has a constitutional unit ratio represented by the following formula (1): (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b1 (R 2 SiO 3 / 2 ) b2 (R 1 2SiO 2 / 2 ) c1 (R 1 R 2 SiO 2 / 2 ) c2 (R 1 3SiO 1 / 2 ) d1 (R 1 2nd Race 2 SiO 1 / 2 ) d2 (R 3 O 1 / 2 ) e (1)

[0011] In formula (1), R 1 R each independently represents a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms. 1Examples of the monovalent hydrocarbon group include alkyl groups preferably having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, and n-hexyl groups; cycloalkyl groups preferably having 5 to 8 carbon atoms, such as cyclohexyl groups; alkenyl groups preferably having 2 to 8 carbon atoms, such as vinyl, allyl, hexenyl, and octenyl groups; aryl groups preferably having 6 to 10 carbon atoms, such as phenyl and tolyl groups; aralkyl groups preferably having 7 to 10 carbon atoms, such as benzyl groups; and monovalent hydrocarbon groups having 1 to 10 carbon atoms in which some or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with hydroxy groups, amino groups, cyano groups, halogen atoms, alkoxysilyl groups, polyoxyalkylene groups, epoxy groups, carboxyl groups, acryloyl groups, methacryloyl groups, acryloyloxy groups, methacryloyloxy groups, and the like. Among these, R 1 is preferably a methyl group or a phenyl group.

[0012] R 2 are each independently -(CH2) m-X (m is an integer of 1 to 20). In the above formula, X represents a monovalent group having a nitrogen-containing heterocycle, which may be a heteroaromatic ring or a heterocycle that is partially or completely saturated, and may have either a monocyclic structure or a polycyclic structure (including a spirocyclic structure). The nitrogen-containing heterocycle may further contain an oxygen atom and / or a sulfur atom within the ring. Specific examples of the nitrogen-containing heteroaromatic ring include pyrrole, maleimide, imidazole, pyrazole, pyrazolone, triazole, tetrazole, pyridine, pyridone, pyrazine, pyrimidine, pyridazine, triazine, tetrazine, azepine, diazepine, oxazole, isoxazole, thiazole, thiazolinone, isothiazole, isothiazolinone, furazan, oxadiazole, oxazine, oxadiazine, oxazepine, oxadiazepine, thiadiazole, thiazine, thiazepine, thiadiazepine, indole, isoindole, indolizine, indazole, pyrindine, quinoline, isoquinoline, quinolizine, purine, phthalazine, pteridine, naphthyridine, quinoxaline, quinazoline, cinnoline, benzoxazole, benzothiazole, benzimidazole, benzofurazan, benzothiadiazole, and benzotriazole rings.

[0013] Specific examples of partially or fully saturated nitrogen-containing heterocycles include pyrroline, pyrrolidone, pyrrolidine, pyrrolizidine, succinimide, imidazoline, imidazolidine, imidazolidone, triazoline, triazolidine, tetrazoline, tetrazolidine, pyrazoline, pyrazolidine, pyrazolidone, dihydropyridine, tetrahydropyridine, piperidine, piperidone, dihydropyrazine, tetrahydropyrazine, piperazine, dihydropyrimidine, tetrahydropyrimidine, perhydropyrimidine, dihydropyridazine, tetrahydropyridazine, and paclitaxel. -hydropyridazine, triazinane, triazinanetrione (isocyanuric acid), dihydroazepine, tetrahydroazepine, perhydroazepine, dihydrodiazepine, tetrahydrodiazepine, perhydrodiazepine, dihydrooxazole, tetrahydrooxazole (oxazolidine), dihydroisoxazole, tetrahydroisoxazole (isoxazolidine), dihydrothiazole (thiazoline), tetrahydrothiazole (thiazolidine), thiazolidinone, dihydroisothiazole (isothiazoline), tetrahydroisothiazoline dihydrooxazepine, tetrahydrooxazepine, perhydrooxazepine, dihydrooxadiazepine, tetrahydrooxadiazepine, perhydrooxadiazepine, dihydrooxadiazepine, dihydrothiadiazole, tetrahydrothiadiazole (thiadiazolidine), dihydrothiazolidine Azine, tetrahydrothiazine, dihydrothiadiazine, tetrahydrothiazepine, tetrahydrothiazepine, perhydrothiazepine, dihydrothiadiazepine, tetrahydrothiadiazepine, perhydrothiadiazepine, morpholine, thiomorpholine, indoline, isoindoline, dihydroindazole, perhydroindazole, dihydroquinoline, tetrahydroquinoline, perhydroquinoline, dihydroisoquinoline, tetrahydroisoquinoline, perhydroisoquinoline, dihydrophthalazine, tetrahydrophthalazine,Examples of such an alkyl group include perhydrophthalazine, dihydronaphthyridine, tetrahydronaphthyridine, perhydronaphthyridine, dihydroquinoxaline, tetrahydroquinoxaline, perhydroquinoxaline, dihydroquinazoline, tetrahydroquinazoline, perhydroquinazoline, dihydrocinnoline, tetrahydrocinnoline, perhydrocinnoline, dihydrobenzoxazine, dihydrobenzothiazine, pyrazinomorpholine, dihydrobenzoxazole, perhydrobenzoxazole, dihydrobenzothiazole, perhydrobenzothiazole, dihydrobenzimidazole, and a perhydrobenzimidazole ring.

[0014] Specific examples of spiro-bonded bicyclic nitrogen-containing heterocycles and bridged bicyclic nitrogen-containing heterocycles include azaspiro[4.4]nonane, oxazaspiro[4.4]nonane, azaspiro[4.5]decane, oxazaspiro[4.5]decane, azabicyclo[2.2.1]heptane, azabicyclo[3.1.1]heptane, azabicyclo[3.2.1]octane, azabicyclo[2.2.2]octane, and azabicyclo[2.2.2]octane rings.

[0015] Among these, nitrogen-containing heteroaromatic rings containing neither oxygen nor sulfur atoms are preferred, and imidazole, benzimidazole, triazole (1,2,3-triazole or 1,2,4-triazole), and benzotriazole rings are more preferred.

[0016] That is, the above X is preferably a group selected from the following formulas (2) to (6).

[0017] (In the formula, the wavy lines represent bonds to adjacent atoms.)

[0018] R 4 R each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms. 4The alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, etc. Specific examples of the aryl group having 6 to 10 carbon atoms include phenyl, tolyl, xylyl, etc.

[0019] Specific examples of X are shown below, but are not limited to these.

[0020] (In the formula, the wavy lines represent bonds to adjacent atoms.)

[0021] m represents an integer of 1 to 20, preferably an integer of 1 to 10. If m exceeds 20, the heterocyclic ring content per unit mass decreases, which may result in decreased corrosion resistance and adhesiveness.

[0022] In formula (1), R 3 represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or an acetyl group, and among these, a hydrogen atom, a methyl group, or an ethyl group is preferred.

[0023] a, b1, b2, c1, c2, d1, and d2 are numbers that satisfy 0≦a<1, 0≦b1<1, 0<b2≦1, 0≦c1<1, 0≦c2<1, 0≦d1<1, and 0≦d2<1, and a+b1+b2+c1+c2+d1+d2=1. From the viewpoint of coatability and corrosion resistance, a range of 0.4≦b2≦1 is preferred, and a range of 0.4≦b2≦0.8 and a range of 0.2≦d1≦0.6 are more preferred. e is a number that satisfies 0≦e≦2, but from the viewpoint of the storage stability and corrosion resistance of the organopolysiloxane, a range of 0.05≦e≦1 is preferred, and a range of 0.10≦e≦1 is more preferred.

[0024] The weight average molecular weight (Mw) of component (A) in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 1,000 to 50,000, and more preferably 1,500 to 30,000. A weight average molecular weight of 1,000 or more provides excellent storage stability, coatability, and film-forming properties, while a weight average molecular weight of 50,000 or less can suppress the occurrence of unevenness and coating irregularities during coating.

[0025] [Method for Producing Organopolysiloxane] The method for producing the organopolysiloxane of the present invention is not particularly limited, and it can be obtained, for example, by (co)hydrolytic condensation of a silane compound represented by the following formula (7) and, if necessary, a silane compound represented by the following formula (8).

[0026] (In the formula, R 1 , R 3 , X, and m have the same meanings as above, and n is an integer of 1 to 3.

[0027] (In the formula, R 1 and R 3 has the same meaning as above, and k is an integer of 1 to 4.

[0028] The silane compound represented by the above formula (7) can be obtained, for example, by reacting (A) a halogenated alkyl group-containing organosilicon compound (hereinafter referred to as compound (A)) with (B) a nitrogen-containing heterocyclic compound (hereinafter referred to as compound (B)) in air or in an inert gas atmosphere such as nitrogen.

[0029] Specific examples of compound (A) include chloromethyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 4-chlorobutyltrimethoxysilane, 4-chlorobutyltriethoxysilane, 4-bromobutyltrimethoxysilane, 4-bromobutyltriethoxysilane, 6-chlorohexyltrimethoxysilane, 6-chlorohexyltriethoxysilane, 6-bromohexyltrimethoxysilane, 6-bromohexyltriethoxysilane, 8-chlorooctyltrimethoxysilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyldimethoxymethylsilane, 8-chlorooctyldiethoxymethylsilane, 8-bromooctyltrimethoxysilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyldimethoxymethylsilane, 8-chlorooctyldiethoxymethylsilane, 8-bromooctyltriethoxysilane, 8-chloro ...triethoxymethylsilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyltriethoxymethylsilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyltriethoxymethylsilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyltriethoxymethylsilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyltriethoxymethylsilane, 8-chlorooctyltriethoxymethylsilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyltriethoxymethyl butyltrimethoxysilane, 8-bromooctyltriethoxysilane, 8-bromooctyldimethoxymethylsilane, 8-bromooctyldiethoxymethylsilane, 10-chlorodecyltrimethoxysilane, 10-chlorodecyltriethoxysilane, 10-bromodecyltrimethoxysilane, 10-bromodecyltriethoxysilane, 11-chloroundecyltrimethoxysilane, 11-chloroundecyltriethoxysilane, 11-bromoundecyltrimethoxysilane, 11-bromoundecyltriethoxysilane, 12-chlorododecyltrimethoxysilane, 12-chlorododecyltriethoxysilane, 12-bromododecyltrimethoxysilane, 12-bromododecyltriethoxysilane, etc. These may be used alone or in combination of two or more. Among these, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 4-chlorobutyltrimethoxysilane, 4-chlorobutyltriethoxysilane, 6-chlorohexyltrimethoxysilane, 6-chlorohexyltriethoxysilane, 8-chlorooctyltrimethoxysilane, 8-chlorooctyltriethoxysilane, 8-chlorooctyldimethoxymethylsilane, 8-chlorooctyldiethoxymethylsilane, 11-chloroundecyltrimethoxysilane, and 11-chloroundecyltriethoxysilane are preferred, and 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane are more preferred.

[0030] Specific examples of compound (B) include imidazole, 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, 4(5)-ethylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-phenylimidazole, 2-phenylimidazole, 2-undecylimidazole, 4-methyl-2-phenylimidazole, 1,2,4-triazole, 1,2,3-triazole, 5,6-dimethylbenzimidazole, 2-ethyl-1H-benzimidazole, 2-methylbenzimidazole, 5-methylbenzimidazole, 2-nonylbenzimidazole, 2-phenylbenzimidazole, benzimidazole, benzotriazole, 5,6-dimethylazimidobenzene, and 5-methylbenzotriazole. These may be used alone or in combination of two or more. Among these, imidazole and benzimidazole are preferred.

[0031] The reaction may be carried out in a solvent as needed, as long as the reaction is not inhibited. Examples of the solvent include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and decane; ether solvents such as tetrahydrofuran and 1,4-dioxane; amide solvents such as formamide, dimethylformamide, and N-methylpyrrolidone; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

[0032] The above reaction is an exothermic reaction, and side reactions may occur at high temperatures. Therefore, the reaction temperature during production is preferably 20 to 150°C, more preferably 30 to 130°C, and even more preferably 40 to 110°C. The reaction time for the above reaction is not particularly limited as long as it allows temperature control of the above-mentioned exothermic reaction and is the time required for the exothermic reaction to be completed, but is preferably 10 minutes to 24 hours, and more preferably 1 to 10 hours.

[0033] Specific examples of the silane compound represented by the above formula (7) include 1-[3(trimethoxysilyl)propyl]-1H-imidazole, 2-methyl-1-[3(trimethoxysilyl)propyl]-1H-imidazole, 1-[3(trimethoxysilyl)propyl]-1H-benzimidazole, 1-[3(trimethoxysilyl)hexyl]-1H-imidazole, 1-[3(trimethoxysilyl)hexyl]-1H-benzimidazole, 1-[3(trimethoxysilyl)octyl]-1H-imidazole, and 1-[3(trimethoxysilyl)octyl]-1H-benzimidazole.

[0034] Specific examples of the silane compound represented by the above formula (8) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, octadecyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, 3-acryloyloxysilane, methyltrieth ... Examples thereof include propyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, trimethoxysilane, triethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethylphenylmethoxysilane, dimethylphenylethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, trivinylmethoxysilane, trivinylethoxysilane, dimethylmethoxysilane, and dimethylethoxysilane.

[0035] The conditions for the hydrolysis reaction are not particularly limited, but can be, for example, at 20 to 150°C for about 0.5 to 6 hours, preferably at 20 to 100°C for about 1 to 4 hours. In this case, a solvent can be added as needed. Examples of the solvent include alcohol solvents such as methanol, ethanol, and isopropyl alcohol; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and aromatic nonpolar solvents such as benzene, toluene, and xylene.

[0036] An acidic catalyst may be used to promote the hydrolysis reaction. A strong acid is preferred as the acidic catalyst, and although no particular limitation is placed on the type, hydrochloric acid, sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, etc. are preferably used. The amount of acidic catalyst added is preferably 100 to 10,000 ppm, more preferably 500 to 5,000 ppm, based on the total mass of the mixed silanes.

[0037] [Surface Treatment Agent] The surface treatment agent of the present invention contains the organopolysiloxane represented by the above formula (1), and can impart corrosion resistance to various materials, articles, etc. Specific examples of the materials and articles include various articles made of various metallic materials such as iron, stainless steel, aluminum, nickel, zinc, and copper.

[0038] Other components contained in the surface treatment agent of the present invention include organic solvents that dissolve the organopolysiloxane. Examples of organic solvents include alcohol solvents such as methanol and ethanol; amide solvents such as formamide, N,N-dimethylformamide, pyrrolidone, and N-methylpyrrolidone; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; saturated hydrocarbon solvents such as pentane, hexane, and heptane; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene, with methanol and ethanol being preferred.

[0039] The amount of organopolysiloxane represented by the above formula (1) is preferably 1 to 40% by mass, more preferably 10 to 30% by mass, based on the surface treatment agent of the present invention, from the viewpoints of corrosion resistance and liquid stability.

[0040] The present invention will be described in more detail below with reference to synthesis examples, working examples, and comparative examples, but the present invention is not limited to these examples. In the following, Me represents a methyl group, Ph represents a phenyl group, and Pr represents an n-propyl group. The weight-average molecular weight (Mw) is a polystyrene-equivalent value determined by gel permeation chromatography (GPC) measurement.

[0041] [1] Synthesis of Silane Compound [Synthesis Example 1] 102.12 g (1.5 mol) of imidazole and 500 g of dimethylformamide were placed in a 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer. 81.03 g (1.5 mol) of sodium methoxide was added while stirring at 10°C, and the mixture was heated to 120°C. 403.28 g (1.5 mol) of 8-chlorooctyltrimethoxysilane was added dropwise thereto, and the mixture was stirred at 120°C for 3 hours. The reaction was then terminated by confirming by gas chromatography (GC) that the peak of the starting imidazole had completely disappeared. Distillation was then performed to obtain a pale yellow liquid silane compound represented by the following formula (9):

[0042]

[0043] Synthesis Example 2 The same procedure as in Synthesis Example 1 was carried out, except that imidazole was changed to 177.21 g (1.5 mol) of benzimidazole, to obtain a colorless, transparent liquid silane compound represented by the following formula (10).

[0044]

[0045] [2] Production of a surface treatment agent containing organopolysiloxane [Example 1-1] Into a nitrogen-purged 100 mL pressure reaction vessel were added 27 g of the silane compound (9) obtained in Synthesis Example 1, 9 g of dimethoxydimethylsilane (KBM-22, manufactured by Shin-Etsu Chemical Co., Ltd.; the same applies hereinafter), 7 g of methanol, and 15 g of water, and the mixture was stirred at 25°C for 1 hour. The water-methanol mixed solvent was then distilled off until the internal temperature reached 100°C, and methanol was then added to give a concentration of 30% by mass, thereby preparing a surface treatment agent containing organopolysiloxane (Mw: 1,590) represented by the following formula (11):

[0046]

[0047] Example 1-2 To a nitrogen-purged 100 mL pressure reaction vessel were added 20 g of the silane compound (9) obtained in Synthesis Example 1, 14 g of dimethoxydiphenylsilane (KBM-202SS, manufactured by Shin-Etsu Chemical Co., Ltd.; the same applies hereinafter), 7 g of methanol, and 11 g of water, and the mixture was stirred at 25°C for 1 hour. The water-methanol mixed solvent was then distilled off until the internal temperature reached 100°C, and methanol was then added to give a concentration of 30% by mass, thereby preparing a surface treatment agent containing an organopolysiloxane (Mw: 1,180) represented by the following formula (12):

[0048]

[0049] Example 1-3 A 100 mL pressure reaction vessel, the inside of which had been purged with nitrogen, was charged with 33 g of the silane compound (10) obtained in Synthesis Example 2, 9 g of dimethoxydimethylsilane, 8 g of methanol, and 15 g of water, and the mixture was stirred at 25°C for 1 hour. The water-methanol mixed solvent was then distilled off until the internal temperature reached 100°C, and methanol was then added to give a concentration of 30% by mass, thereby preparing a surface treatment agent containing an organopolysiloxane (Mw: 1,380) represented by the following formula (13).

[0050]

[0051] Example 1-4 A 100 mL pressure reaction vessel, the inside of which had been purged with nitrogen, was charged with 25 g of the silane compound (10) obtained in Synthesis Example 2, 14 g of dimethoxydiphenylsilane, 7 g of methanol, and 11 g of water, and the mixture was stirred at 25°C for 1 hour. The water-methanol mixed solvent was then distilled off until the internal temperature reached 100°C, and methanol was then added to give a concentration of 30% by mass, thereby preparing a surface treatment agent containing an organopolysiloxane (Mw: 1,120) represented by the following formula (14):

[0052]

[0053] Comparative Example 1-1: A 100 mL pressure reaction vessel purged with nitrogen was charged with 19 g of n-propyltrimethoxysilane (KBM-3033, manufactured by Shin-Etsu Chemical Co., Ltd.; the same applies hereinafter), 9 g of dimethoxydimethylsilane, 5 g of methanol, and 15 g of 0.05 N aqueous HCl solution, and the mixture was stirred at 65° C. for 2 hours. 0.7 g of a 10% aqueous AcONa solution was then added, and the mixture was stirred at 65° C. for 2 hours. The water-methanol mixed solvent was then distilled off until the internal temperature reached 100° C., and methanol was then added to a concentration of 30% by mass, thereby preparing a surface treatment agent containing an organopolysiloxane (Mw: 1,480) represented by the following formula (15):

[0054]

[0055] Comparative Example 1-2: 14 g of n-propyltrimethoxysilane, 14 g of dimethoxydiphenylsilane, 5 g of methanol, and 11 g of 0.05 N aqueous HCl solution were added to a nitrogen-purged 100 mL pressure reaction vessel and stirred for 2 hours at 65° C., after which 0.5 g of a 10% aqueous AcONa solution was added and stirred for 2 hours at 65° C. Thereafter, the water-methanol mixed solvent was distilled off until the internal temperature reached 100° C., and then methanol was added to a concentration of 30% by mass, thereby preparing a surface treatment agent containing an organopolysiloxane (Mw: 1,160) represented by the following formula (16):

[0056]

[0057] [3] Production of Treated Articles [Examples 2-1 to 2-5, Comparative Examples 2-1 and 2-2] A commercially available copper plate (manufactured by KDS Corporation; 70 × 150 × 1 mm) was pretreated by immersing it in a 30% by mass HSO aqueous solution for 30 seconds and then drying. The pretreated copper plate was coated with the surface treatment agents obtained in Examples 1-1 to 1-4 and Comparative Examples 1-1 and 1-2 using a bar coater 5 and dried in an oven at 105°C for 60 minutes to obtain test plates with a coating film formed on the copper plate. The heat resistance and corrosion resistance of the obtained test plates were evaluated according to the evaluation methods below, and the results are shown in Table 1.

[0058] [Evaluation of Heat Resistance] The test plate was heat treated in an oven at 150° C. for 24 hours, and then the appearance was visually evaluated as follows: ⊚: No discoloration ◯: Slight discoloration to orange or yellow ×: Discoloration to dark brown

[0059] [Evaluation of corrosion resistance] The obtained test plates were subjected to a salt spray test based on JIS Z 2371:2015 for 50 hours, 100 hours, and 200 hours, after which the corroded area was measured and the corrosion resistance was evaluated according to the following method: A: Corroded area is 0% B: Corroded area is more than 0% but less than 30% C: Corroded area is 30% or more but less than 50% D: Corroded area is 50% or more but less than 70% E: Corroded area is 70% or more

[0060]

[0061] As shown in Table 1, the treated copper plates of Examples 2-1 to 2-4 are superior in heat resistance and rust prevention (corrosion resistance) to those of Comparative Examples 2-1 and 2-2.

Claims

1. An organopolysiloxane having a structural unit ratio represented by the following formula (1): (SiO 4 / 2 ) a (R 1 SiO 3 / 2 ) b1 (R 2 SiO 3 / 2 ) b2 (R 1 2SiO 2 / 2 ) c1 (R 1 R 2 SiO 2 / 2 ) c2 (R 1 3SiO 1 / 2 ) d1 (R 1 2nd Race 2 SiO 1 / 2 ) d2 (R 3 O 1 / 2 ) e (1) [wherein, R 1 are each independently a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently -(CH2) m -X (X represents a monovalent group having a nitrogen-containing heterocycle, and m is an integer of 1 to 20), and R 3 represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or an acetyl group, and a, b1, b2, c1, c2, d1, and d2 are numbers that satisfy 0≦a<1, 0≦b1<1, 0<b2≦1, 0≦c1<1, 0≦c2<1, 0≦d1<1, and 0≦d2<1, and a+b1+b2+c1+c2+d1+d2=1, and e is a number that satisfies 0≦e≦2.] 2. The organopolysiloxane according to claim 1, wherein X is a group selected from the following formulas (2) to (6): (In the formula, R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and the wavy line represents a bond to an adjacent atom.

3. The organopolysiloxane according to claim 1, wherein b2 is a number satisfying the relationship 0.4≦b2≦1.

4. A surface treatment agent containing the organopolysiloxane according to any one of claims 1 to 3.

5. An article treated with the organopolysiloxane of any one of claims 1 to 3.

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