Resin-linear structure-containing organopolysiloxane, composition comprising same, and method for producing same

Abstract

This resin-linear structure-containing organopolysiloxane having a constituent unit ratio represented by formula (1) and a weight average molecular weight of 1,000,000-20,000,000 exhibits excellent film-forming properties and no stickiness at room temperature and provides a cured film that can achieve both hardness and flexibility. (In the formula, R1, R3, R3, R4 and R5 are each independently a hydrogen atom or a C1-C20 hydrocarbon group, m is an integer of 0-50, a, b, c, d and e are numbers satisfying 0≤a≤0.25, 0.05≤b≤(m+2)≤0.3, 0≤c≤0.25, 0.7≤d≤0.95, 0≤e≤0.25, and a+b×(m+2)+c+d+e=1, and x is a number satisfying 0<x≤0.1.)

Description

Resin-linear structure-containing organopolysiloxane, composition containing the same, and method for producing the same

[0001] The present invention relates to a resin-linear structure-containing organopolysiloxane, a composition containing the same, and a method for producing the same.

[0002] Silicone resins containing silanol groups in their polymer structure have traditionally been used as heat-resistant and weather-resistant coatings, taking advantage of their excellent heat resistance, weather resistance, and rigidity. Furthermore, these silicone resins are also useful as modification raw materials for producing hybrid resins by reacting them with various organic resins, and have been used in a wide range of fields.

[0003] Especially SiO 4 / 2 Units (Q units) and RSiO 3 / 2 Organopolysiloxanes, which have a three-dimensional crosslinked structure and are mainly composed of units (T units) (where R is an organic group such as an alkyl group or aryl group), are called silicone resins and are widely used in paints, coatings, and binders by utilizing the formation of siloxane bonds through the dehydration condensation reaction of silanol groups and their crosslinking curability.

[0004] However, while such silicone resins have the advantage of good curability and high surface hardness due to their three-dimensional crosslinking structure, they also have the problem of insufficient flexibility and bending resistance due to their high crosslinking density, which can lead to cracks forming in the cured product over time after film formation or when external stress is applied.

[0005] To improve this flexibility and bending resistance, diorganosiloxane (R2SiO) is added to the polymer structure of the silicone resin. 2 / 2 A commonly known method involves incorporating units (D units). However, in this case, since D units are randomly incorporated into the structure, a large number of D units must be added to impart flexibility, which leads to a decrease in the excellent curability and surface hardness that are advantages of silicone resin.

[0006] Furthermore, as a method for introducing D units, a method has been proposed in which silicone oil, whose molecular ends are sealed with tetraethoxysilane which has reactivity with silanol groups, is added to silicone resin (Non-Patent Literature 1). However, silicone oil has low compatibility with silicone resin, which has caused clouding and repelling of the coating film.

[0007] To solve these problems, a technique has been proposed to chemically bond a silicone resin structure and a linear silicone structure to form an organopolysiloxane. For example, Patent Document 1 proposes a resin-linear structure-containing organopolysiloxane obtained by hydrosilylation reaction between a linear polysiloxane having hydrosilyl groups at its ends and a silicone resin having olefin groups and alkoxysilyl groups. Patent Document 2 also proposes a resin-linear structure-containing organopolysiloxane obtained by hydrolyzing and condensing a polydimethylsiloxane having silanol groups at both ends with a highly reactive tri- or tetrafunctional hydrolyzable silane monomer.

[0008] However, the organopolysiloxane in Patent Document 1 has a relatively long-chain, high-molecular-weight linear structure. While it is effective when added as a crack-resistant agent, its hardness is insufficient when cured on its own, making it difficult to use alone for coating applications. Furthermore, while Patent Document 2 introduces a linear structure to reduce stickiness derived from the resin component, it does not consider aspects such as crack prevention through improved flexibility or improved curability, leaving room for improvement in these properties.

[0009] As methods for producing silanol-containing silicone resins with ensured reactivity, continuous and batch hydrolysis condensation methods (sol-gel methods) are widely known. For example, Patent Documents 3 and 4 disclose a continuous hydrolysis process, while Patent Document 5 discloses a batch hydrolysis process.

[0010] Generally, these patent documents use chlorosilanes or alkoxysilanes as reactive silane monomers. In particular, in systems with a high proportion of resin components that provide three-dimensional crosslinking, such as Q-units or T-units, controlling the reaction during hydrolysis is difficult. The aforementioned patent documents on manufacturing methods attempt to suppress the formation of solvent-insoluble gel components by measures such as adjusting the reaction temperature, using alcohols in combination, and setting a lower target molecular weight for the resin structure. However, when increasing the proportion of resin components and aiming for a higher target molecular weight, further improvements to the manufacturing conditions are required to suppress gelation and improve the stability of the resulting resin.

[0011] Japanese Patent Publication No. Hei 6-271650, International Publication No. 2018 / 66572, Japanese Patent Publication No. 2016-521804, Japanese Patent Publication No. 2019-533752, Japanese Patent Publication No. 2007-314671

[0012] Polymeric Materials Science and Engineering, 1998, Vol. 79,192

[0013] The present invention has been made in view of the above circumstances, and aims to provide a resin-linear structure-containing organopolysiloxane that exhibits excellent film-forming properties and non-stickiness at room temperature, and provides a cured film that is capable of both hardness and flexibility, a composition containing the same, and a method for producing the same.

[0014] As a result of diligent research to solve the above problems, the inventors of the present invention have found that a predetermined resin-linear structure-containing organopolysiloxane provides the desired film properties, and that this resin-linear structure-containing organopolysiloxane can be stably obtained by hydrolysis and condensation of organopolysiloxanes having chlorosilane and chlorosilyl groups in a predetermined reaction solvent composition, thereby completing the present invention.

[0015] In other words, the present invention relates to: 1. A resin-linear structure-containing organopolysiloxane having a constituent unit ratio represented by the following formula (1) and a weight-average molecular weight of 1,000,000 to 20,000,000. (In the formula, R 1 , R 2 , R 3, R 4 and R 5 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, m is an integer of 0 to 50, and a, b, c, d, and e are such that 0 ≦ a ≦ 0.25, 0.05 ≦ b×(m + 2) ≦ 0.3, 0 ≦ c ≦ 0.25, 0.7 ≦ d ≦ 0.95, 0 ≦ e ≦ 0.25, and a + b×(m + 2) + c + d + e = 1, and x is a number such that 0 < x ≦ 0.1. 2. The above R 1 , R 2 , R 3 and R 4 in which the monovalent hydrocarbon group having 1 to 20 carbon atoms is a methyl group, a resin-linear structure-containing organopolysiloxane of 1. 3. A resin-linear structure-containing organopolysiloxane of 1 in which m is an integer of 10 to 50 and a, c, and e are 0. 4. 29 In the Si-NMR spectrum, the chemical shift of the signal attributed to the D unit is detected in the range of -15 to -25 ppm, and the peak detection width of the signal (the difference between the chemical shift of the detection start point and the chemical shift of the detection end point) is 3 to 8 ppm, a resin-linear structure-containing organopolysiloxane of 1. 5. A composition comprising any one of the resin-linear structure-containing organopolysiloxanes of 1 to 4 and an organic solvent, and having a pH of the extracted water in the range of 3.5 to 6.0. 6. The composition of 5 in which the organic solvent is an aliphatic hydrocarbon. 7. The composition of 5 containing a carboxylic acid. 8. A method for producing a composition according to any one of 1 to 5, comprising hydrolytically condensing a silane compound having a chlorine atom bonded to a silicon atom and a linear organopolysiloxane having chlorine atoms bonded to silicon atoms at both ends of the molecular chain in a mixed medium layer composed of water, a hydrophilic organic solvent having a water solubility of 50 to 1000 g / L at 25°C, and a hydrophobic organic solvent having a water solubility of 1 g / L or less at 25°C, and adjusting the pH of the extracted water to be in the range of 3.5 to 6.0. 9. The method for producing a composition of 8 in which the linear organopolysiloxane is a linear organopolysiloxane represented by the following formula (2). (wherein m is an integer from 0 to 50.) 10. A method for producing composition 8, wherein the hydrophilic organic solvent is one or more selected from 1-propanol, 2-propanol, 1-butanol, and isobutanol. 11. A method for producing composition 8, wherein the hydrophobic organic solvent is one or more selected from hexane, heptane, octane, cyclohexane, methylcyclohexane, and ethylcyclohexane. 12. A coating agent comprising composition 5. 13. An article having a cured film of the coating agent of 12.

[0016] The resin-linear structure-containing organopolysiloxane of the present invention exhibits excellent film-forming properties, efficiently demonstrating flexibility despite its high T-unit ratio, thanks to the introduction of a linear structure. Furthermore, the film obtained from a composition containing the resin-linear structure-containing organopolysiloxane of the present invention is suitable as a coating agent because it can achieve both hardness and flexibility (crack resistance).

[0017] The present invention will be described in detail below. [Resin-Linear Structure-Containing Organopolysiloxane] The resin-linear structure-containing organopolysiloxane according to the present invention has a constituent unit ratio represented by the following general formula (1).

[0018]

[0019] In equation (1), R 1 , R 2 , R 3 , R 4 and R 5 Each of these is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. 1 , R 2 , R 3 and R 4Specific examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms in R include alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-decyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl, allyl, butenyl, hexenyl, and octenyl groups; and aryl groups such as phenyl and naphthyl groups. Among these, methyl, ethyl, n-propyl, and phenyl groups are preferred, methyl and ethyl groups are more preferred, and methyl groups are even more preferred. 5 Specific examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms in the above are the same as those mentioned above, but alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, and t-butyl groups are preferred, and n-butyl, s-butyl, i-butyl, and t-butyl groups are more preferred.

[0020] In formula (1), m is an integer from 0 to 50, and is preferably an integer from 10 to 40 from the viewpoint of achieving the desired flexibility. a, b, c, d, and e represent the molar ratio of each constituent unit, and are numbers that satisfy 0 ≤ a ≤ 0.25, 0.05 ≤ b × (m + 2) ≤ 0.3, 0 ≤ c ≤ 0.25, 0.7 ≤ d ≤ 0.95, 0 ≤ e ≤ 0.25, and a + b × (m + 2) + c + d + e = 1. From the viewpoint of achieving both hardness and flexibility, it is preferable that c and e are 0, and more preferable that a, c, and e are 0.

[0021] In formula (1), x is the number of moles of hydroxyl groups or organoxy groups bonded to 1 mole of Si atoms, satisfying the condition 0 < x ≤ 0.1. When x is 0, it means that there are no structural groups to undergo dehydration or dealcoholization condensation crosslinking. While this is excellent in terms of polymer stability, it is undesirable because it lacks curability, thus reducing the durability of the resulting cured film. On the other hand, when x is greater than 0.1, curability is excellent, but the stability of the polymer may decrease.

[0022] The weight-average molecular weight of the resin-linear structure-containing organopolysiloxane of the present invention is 1,000,000 to 20,000,000, from the viewpoint of film-forming properties and non-stickiness of the cured film. More preferably, it is 1,500,000 to 10,000,000, and even more preferably, 2,000,000 to 8,000,000. The weight-average molecular weight in the present invention is the standard polystyrene equivalent value obtained by gel permeation chromatography (GPC) measured under the following conditions. [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.5 mL / min Detector: Differential refractive index detector (RI) Column: Two of the following columns are used in direct connection. TSKgel GMH HR -H(30) (7.8 mm I.D. × 30 cm × 1) (Manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 200 μL (20 g / L THF solution)

[0023] The resin-linear structure-containing organopolysiloxane of the present invention has a linear organopolysiloxane structure, and as an indicator thereof 29 This can be determined by detecting signals in the Si-NMR spectrum that belong to structures corresponding to a predetermined range of chemical shifts. 29 In Si-NMR spectra, signals originating from D units are detected in the range of -10 to -50 ppm. However, in the resin-linear structure-containing organopolysiloxane of the present invention, the chemical shift of the signal attributed to D units derived from the linear organopolysiloxane structure is detected in the range of -15 to -25 ppm. Furthermore, the detection width of the above signal peak (the difference between the chemical shift at the detection start point and the chemical shift at the detection end point) is in the range of 3 to 8 ppm. A narrower detection width of the signal peak indicates that the linear siloxane structure is maintained while being introduced into the polymer, while a larger detection width means that the proportion of continuous D units in the polymer is small. 29 The Si-NMR spectrum was obtained by measuring a solution sample with a sample concentration of 20% by mass using a 300 MHz NMR analyzer manufactured by JEOL Ltd., under conditions of 25°C.

[0024] [Composition containing a resin-linear structure-containing organopolysiloxane] The resin-linear structure-containing organopolysiloxane of the present invention can be prepared as a composition dissolved in an organic solvent, but the pH of the extracted water must be in the acidic range of 3.5 to 6. By adjusting the pH of the extracted water to this range, it is possible to obtain a stable composition that does not cause gelation or the like over a long period of time.

[0025] To adjust the pH of the extracted water, for example, an acid can be used. Examples of acids include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; carboxylic acids such as formic acid, acetic acid, propionic acid, citric acid, succinic acid, and maleic acid; and sulfonic acids such as methanesulfonic acid and trifluoromethanesulfonic acid. Among these, carboxylic acids are preferred.

[0026] The organic solvent in the composition of the present invention is not particularly limited, but examples include aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, decane, isododecane, and isoparaffin compounds, and aromatic hydrocarbons such as toluene and xylene. From the viewpoint of environmental impact, aliphatic hydrocarbons are preferred, hexane, heptane, octane, cyclohexane, methylcyclohexane, and ethylcyclohexane are more preferred, and hexane, heptane, and ethylcyclohexane are even more preferred.

[0027] [Method for producing a composition containing a resin-linear structure-containing organopolysiloxane] The composition containing a resin-linear structure-containing organopolysiloxane of the present invention can be produced, for example, by a production method comprising the steps of hydrolyzing and condensing a silane compound having a chlorine atom bonded to a silicon atom and a linear organopolysiloxane having chlorine atoms bonded to silicon atoms at both ends of the molecular chain in a mixed medium layer consisting of water, a hydrophilic organic solvent with a water solubility of 50 to 1000 g / L at 25°C and a hydrophobic organic solvent with a water solubility of 1 g / L or less at 25°C, and adjusting the pH of the extracted water to 3.5 to 6.0.

[0028] Specific examples of the above hydrophilic organic solvents include alcohols, ketones, esters, and ether compounds. Specifically, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol (isobutanol), 2-methyl-2-propanol (t-butanol), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, etc. may be mentioned. Among these, from the viewpoints of reaction control during hydrolysis condensation and suppression of the formation of insoluble substances, 1-propanol, 2-propanol, 1-butanol, and isobutanol are preferred.

[0029] Specific examples of the above hydrophobic organic solvents include aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, decane, isododecane, and isoparaffin compounds; aromatic hydrocarbons such as toluene and xylene, etc. Among these, from the viewpoints of reaction control during hydrolysis condensation, block structure maintenance, solubility of the resin to be produced, etc., hexane, heptane, octane, cyclohexane, methylcyclohexane, and ethylcyclohexane are preferred, and hexane, heptane, and ethylcyclohexane are more preferred.

[0030] In the above mixed medium layer, the composition ratio is preferably 10 to 30 parts by mass of the hydrophilic organic solvent and 10 to 30 parts by mass of the hydrophobic organic solvent with respect to 100 parts by mass of water. Within such a range, insoluble substances in the solvent are suppressed and productivity is excellent.

[0031] Specific examples of the silane compound having a chlorine atom bonded to the silicon atom include chlorosilane compounds such as tetrachlorosilane, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, methylphenyldichlorosilane, trimerylchlorosilane, and triphenylchlorosilane. In addition to these chlorosilane compounds, an alkoxysilane compound capable of constituting each siloxane unit in the above formula (1) such as methyltrimethoxysilane may be used in combination for co-hydrolysis condensation.

[0032] The linear organopolysiloxane having chlorine atoms bonded to the silicon atom at both ends of the molecular chain can be any one that gives the constituent unit "b" in formula (1) above, and in particular, the linear organopolysiloxane represented by the following formula (2) is preferred.

[0033] (In the formula, m has the same meaning as above.)

[0034] The total concentration of the silane compound having a chlorine atom bonded to a silicon atom and the linear organopolysiloxane having chlorine atoms bonded to silicon atoms at both ends of the molecular chain during the hydrolysis condensation reaction is preferably 10 to 30% by mass relative to the entire reaction system. Within this range, unwanted substances in the solvent are suppressed, and productivity is excellent.

[0035] Furthermore, from the viewpoint of reaction control and productivity, the temperature during the hydrolysis condensation reaction is preferably in the range of 10 to 80°C, and the pH is preferably in the range of 1 to 3.

[0036] In the manufacturing method of the present invention, it is preferable to perform a step of allowing the reaction solution to stand to separate it into an organic phase and an aqueous phase, and then removing the aqueous phase, before the step of adjusting the pH of the extracted water to 3.5 to 6.0. This step efficiently adjusts the pH by removing hydrogen chloride and hydrochloric acid generated by the hydrolysis of silane compounds having chlorine atoms bonded to silicon atoms, and linear organopolysiloxanes having chlorine atoms bonded to silicon atoms at both ends of the molecular chain. Furthermore, it is preferable to repeatedly wash the aqueous phase with water until it becomes neutral in order to remove any remaining hydrogen chloride and hydrochloric acid in the organic phase.

[0037] To adjust the pH of the extracted water, for example, an acid can be used. Examples of acids include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid; carboxylic acids such as formic acid, acetic acid, propionic acid, citric acid, succinic acid, and maleic acid; and sulfonic acids such as methanesulfonic acid and trifluoromethanesulfonic acid. Among these, carboxylic acids are preferred. The pH of the extracted water is in the acidic range of 3.5 to 6. By adjusting it to this range, a stable composition can be obtained without causing gelation or other problems over a long period of time.

[0038] [Coating agent and article having a cured coating film of the coating agent] The composition containing the resin-linear structure-containing organopolysiloxane of the present invention can be used as a coating agent, and by applying it to the surface of a solid substrate and curing it, an article having a cured coating film can be obtained.

[0039] The application method is not particularly limited, and can be appropriately selected from known methods such as spray coating, spin coating, dip coating, roller coating, brush coating, bar coating, and flow coating.

[0040] The material and shape of the solid substrate are not particularly limited, and specific examples include epoxy resins, phenolic resins, polycarbonates and polycarbonate blends, acrylic resins such as poly(methyl methacrylate), polyester resins such as poly(ethylene terephthalate), poly(butylene terephthalate), and unsaturated polyester resins, polyamide resins, polyimide resins, acrylonitrile-styrene copolymers, styrene-acrylonitrile-butadiene copolymers, polyvinyl chloride resins, polystyrene resins, blends of polystyrene and polyphenylene ether, cellulose acetate butyrate, polyethylene resins and other organic polymer substrates, metal substrates such as steel plates, painted surfaces, glass, ceramics, concrete, slate, textiles, wood, stone, roof tiles, inorganic fillers such as (hollow) silica, titania, zirconia, and alumina, and glass fiber products such as glass cloth, glass tape, glass mat, and glass paper.

[0041] The resin-linear structure-containing organopolysiloxane of the present invention has a linear siloxane structure and a high molecular weight. Therefore, a cured film made from a composition containing this has good strength and flexibility, and can be suitably used for coating, sealing, and other applications.

[0042] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited to these. In the following examples, "parts" and "%" mean "parts by mass" and "mass%", respectively.

[0043] [1] Synthesis of Resin-Linear Structure-Containing Organopolysiloxane [Example 1] (1) Step 1 In a 5 L three-necked flask equipped with a stirrer, condenser, dropping funnel and thermometer, 2700 g of deionized water, 400 g of isobutanol (solubility in water at 25°C: 87 g / L), and 300 g of heptane (solubility in water at 25°C: 0.05 g / L) were added. While stirring at 25°C, a mixture of 650 g (4.3 mol) of methyltrichlorosilane, 70 g (0.9 mol in Si equivalent) of a linear organopolysiloxane represented by the following formula (3), and 300 g of heptane was added dropwise over 2 hours while controlling the temperature so that the internal temperature did not exceed 40°C.

[0044]

[0045] (2) Step 2 After the completion of Step 1, the mixture was allowed to stand to separate into an organic phase and an aqueous phase, and the aqueous phase was removed. (3) Step 3 After the completion of Step 2, 20 g of 36% hydrochloric acid was added to the organic phase, and the mixture was heated at 60°C for 3 hours to carry out a condensation polymerization reaction. After cooling to 25°C, heptane was added to the organic phase to adjust the concentration. (4) Step 4 After the completion of Step 3, the aqueous phase was repeatedly washed with saline solution until it became neutral, and then 0.03% citric acid was added to the solution to obtain a solution of resin-linear structure-containing organopolysiloxane.

[0046] [Example 2] The same procedure as in Example 1 was followed, except that in step 3 of Example 1, the condensation polymerization reaction conditions were changed to 60°C for 5 hours, in order to obtain a solution of resin-linear structure-containing organopolysiloxane.

[0047] [Example 3] The same procedure as in Example 1 was followed, except that heptane was replaced with isododecane (water solubility at 25°C: 0.001 g or less / L) in steps 1 and 3 of Example 1, to obtain a solution of resin-linear structure-containing organopolysiloxane.

[0048] [Example 4] In step 1 of Example 1, the amount of linear organopolysiloxane represented by formula (3) added was changed to 35 g (0.45 moles in terms of Si), but the same procedure as in Example 1 was performed to obtain a resin-linear structure-containing organopolysiloxane solution.

[0049] [Example 5] In step 1 of Example 1, the amount of linear organopolysiloxane represented by formula (3) added was changed to 123 g (1.6 moles in terms of Si), but the same procedure as in Example 1 was performed to obtain a resin-linear structure-containing organopolysiloxane solution.

[0050] [Example 6] In Example 1, the same procedure was followed as in Example 1, except that heptane was replaced with isododecane (water solubility at 25°C: 0.001 g / L or less) in steps 1 and 3, and the condensation polymerization reaction conditions were set to 60°C for 5 hours, in order to obtain a resin-linear structure-containing organopolysiloxane solution.

[0051] [Example 7] In step 1 of Example 1, a solution of resin-linear structure-containing organopolysiloxane was obtained by performing the same steps as in Example 1, except that a mixture of methyltrichlorosilane and heptane was added dropwise, followed by the addition of the linear organopolysiloxane represented by formula (3) above.

[0052] [Example 8] In Example 1, after the completion of step 4, 10 g (0.1 mol) of triethylamine and 8 g (0.07 mol) of trimethylchlorosilane were added to the organic phase and the reaction was carried out by heating at 60°C for 3 hours. After that, the aqueous phase was repeatedly washed with saline solution until it became neutral, and then 0.03% citric acid was added to the solution to obtain a solution of resin-linear structure-containing organopolysiloxane.

[0053] [Example 9] In Example 1, after the completion of step 4, 10 g (0.1 mol) of triethylamine and 9 g (0.07 mol) of vinyldimethylchlorosilane were added to the organic phase and the reaction was carried out by heating at 60°C for 3 hours. After that, the aqueous phase was repeatedly washed with saline solution until it became neutral, and then 0.03% citric acid was added to the solution to obtain a solution of resin-linear structure-containing organopolysiloxane.

[0054] [Comparative Example 1] A solution of organopolysiloxane was obtained by performing the same steps as in Example 1, except that in step 1 of Example 1, the linear organopolysiloxane represented by formula (3) above was replaced with an equimolar amount of dimethyldichlorosilane in terms of Si atoms.

[0055] [Comparative Example 2] A solution of organopolysiloxane was obtained by performing the same steps as in Example 1, except that in step 1 of Example 1, the linear organopolysiloxane represented by formula (3) above was not used, and in steps 1 and 3, heptane was replaced with toluene (water solubility at 25°C: 0.5 g / L).

[0056] [Comparative Example 3] In step 1 of Example 1, the amount of linear organopolysiloxane represented by formula (3) added was changed to 330 g (4.3 moles in terms of Si), and in steps 1 and 3, heptane was changed to isododecane (water solubility at 25°C: 0.001 g or less / L). Otherwise, the same steps as in Example 1 were performed to obtain a resin-linear structure-containing organopolysiloxane solution.

[0057] [Comparative Example 4] A solution of resin-linear structure-containing organopolysiloxane was obtained by performing the same steps as in Example 1, except that step 4 was performed instead of step 3.

[0058] [Comparative Example 5] A solution of resin-linear structure-containing organopolysiloxane was obtained by performing the same procedure as in Example 1, except that the condensation polymerization reaction conditions in step 3 of Example 1 were set to 60°C for 1 hour.

[0059] [Comparative Example 6] A solution of resin-linear structure-containing organopolysiloxane was obtained by performing the same steps as in Example 1, except that citric acid was not added in step 4 of Example 1.

[0060] [Comparative Example 7] A solution of resin-linear structure-containing organopolysiloxane was obtained by performing the same steps as in Example 1, except that step 4 was omitted.

[0061] [Comparative Example 8] In step 1 of Example 1, when isobutanol was not added and the amount of heptane added was doubled, a large amount of insoluble material precipitated during the hydrolysis reaction, and it was not possible to obtain an organopolysiloxane solution.

[0062] [Comparative Example 9] In step 1 of Example 1, when isobutanol was changed to methanol (water solubility at 25°C: over 1000 g / L) and heptane was changed to toluene (water solubility at 25°C: 0.5 g / L), a large amount of insoluble material precipitated during the hydrolysis reaction, and it was not possible to obtain an organopolysiloxane solution.

[0063] The constituent unit ratios of the organopolysiloxanes obtained in Examples 1 to 9 and Comparative Examples 1 to 7 above, 29 Information on signals attributed to D units in Si-NMR spectra, weight-average molecular weight determined by GPC, and physical properties of organopolysiloxane solutions were measured using the following methods. The results are shown in Table 1.

[0064] (1) Nuclear magnetic resonance spectrum ( 29 (1) Si-NMR Instrument: JEOL Ltd. 300MHz-NMR Solvent: CDCl3 Sample concentration: 20% Internal standard: Tetramethylsilane (TMS) (2) Gel permeation chromatography (GPC) Instrument: Tosoh Corporation HLC-8320GPC Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.5 mL / min Detector: Differential refractive index detector (RI) Column: Two of the following columns are used in direct connection. TSKgel GMH HR -H(30) (7.8 mm I.D. × 30 cm × 1) (Manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 200 μL (THF solution with a concentration of 20 g / L) Standard: Monodisperse polystyrene (3) pH of extracted water 30 g of organopolysiloxane solution and 30 g of distilled water were placed in a 100 ml polyethylene bottle, stirred for 30 minutes, and then allowed to stand. The pH of the separated aqueous layer was measured. (4) Non-volatile content The non-volatile content was calculated from the change in mass before and after drying the organopolysiloxane solution at 105°C for 3 hours. (5) Kinematic viscosity The kinematic viscosity of the organopolysiloxane solution was measured at 25°C using a Cannon-Fenske viscometer in accordance with JIS Z 8803:2011. (6) Storage Stability The fluidity of the organopolysiloxane solution was checked after storage at 50°C for one month, and the following evaluation was performed. ○: Fluidity present ×: Gelated and not fluid

[0065]

[0066] As shown in Table 1, Comparative Example 2, which used an organopolysiloxane composed solely of T units, and Comparative Examples 6 and 7, in which the pH of the extracted water was outside the range of the present invention, showed poor storage stability.

[0067] The organopolysiloxane solutions obtained in Examples 1-9 and Comparative Examples 1-7 were applied to glass substrates (except for polished steel plates used for the flexibility test) using bar coater No. 14, and allowed to stand at 25°C for 3 hours to form a coating film. The results of the evaluation of the obtained coating films are shown in Table 2.

[0068] (1) The condition of the curable coating film was checked by touch and evaluated according to the following criteria. ◎: No tack, fully cured. Slippery. ○: No tack, fully cured. Not slippery. ×: Curing abnormalities such as tack. (2) After storing the heat-resistant coating film in a 200°C oven for 12 hours, the surface was visually inspected to determine if there were any abnormalities. ○: No abnormalities ×: Abnormalities such as cracks. (3) Adhesion In accordance with JIS K5600, 25 grids were created by making 6 vertical and 6 horizontal cuts at 2 mm intervals in the coating film using a razor blade, and after firmly adhering cellophane tape (registered trademark, manufactured by Nichiban Co., Ltd.), when it was rapidly peeled off in a 90° direction towards the user, the number of squares (X) that remained without peeling off the coating film was expressed as X / 25. (4) Pencil hardness was measured by applying a load of 750g in accordance with the pencil scratch test described in JIS K5600-5-4. (5) Test specimens with a hardened coating formed on a flexible polished steel plate were measured using a cylindrical mandrel (Type 1) in accordance with the method described in JIS K 5600-5-1.

[0069]

[0070] As shown in Table 2, the coatings obtained from the organopolysiloxane solutions of Examples 1 to 9 exhibit excellent curability, heat resistance, adhesion, hardness, and flexibility. On the other hand, Comparative Examples 1 and 2, which do not contain linear organopolysiloxane moieties, showed poor heat resistance in the coatings, and in particular, the coating of Comparative Example 2, which does not contain D units, showed significantly poor flexibility. Furthermore, the organopolysiloxane solutions of Comparative Example 3, which contain an excess of linear organopolysiloxane moieties, and Comparative Examples 4 and 5, which have low molecular weights, showed poor curability, and the coating obtained from the organopolysiloxane solution of Comparative Example 7, where the extract water pH is 1.0, showed poor heat resistance.

Claims

1. A resin-linear structure-containing organopolysiloxane having a constituent unit ratio represented by the following formula (1) and a weight-average molecular weight of 1,000,000 to 20,000,000. (In the formula, R 1 , R 2 , R 3 , R 4 and R 5 Each of the elements is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, m is an integer from 0 to 50, a, b, c, d, and e are numbers satisfying the following conditions: 0 ≤ a ≤ 0.25, 0.05 ≤ b × (m + 2) ≤ 0.3, 0 ≤ c ≤ 0.25, 0.7 ≤ d ≤ 0.95, 0 ≤ e ≤ 0.25, and a + b × (m + 2) + c + d + e = 1, and x is a number where 0 < x ≤ 0.

1.

2. The R 1 , R 2 , R 3 and R 4 in the resin-linear structure-containing organopolysiloxane according to claim 1, wherein the monovalent hydrocarbon group having 1 to 20 carbon atoms is a methyl group.

3. The resin-linear structure-containing organopolysiloxane according to claim 1, wherein m is an integer between 10 and 50, and a, c, and e are 0.

4. 29 The resin-linear structure-containing organopolysiloxane according to claim 1, wherein, in the Si-NMR spectrum, the chemical shift of the signal attributed to the D unit is detected in the range of -15 to -25 ppm, and the peak detection width of the signal (the difference between the chemical shift at the detection start point and the chemical shift at the detection end point) is 3 to 8 ppm.

5. A composition comprising a resin-linear structure-containing organopolysiloxane according to any one of claims 1 to 4, and an organic solvent, wherein the pH of the extracted water is in the range of 3.5 to 6.

0.

6. The composition according to claim 5, wherein the organic solvent is an aliphatic hydrocarbon.

7. The composition according to claim 5, comprising a carboxylic acid.

8. A method for producing the composition according to claim 5, comprising the steps of hydrolyzing and condensing a silane compound having a chlorine atom bonded to a silicon atom and a linear organopolysiloxane having chlorine atoms bonded to silicon atoms at both ends of its molecular chain in a mixed medium layer comprising water, a hydrophilic organic solvent having a water solubility of 50 to 1000 g / L at 25°C and a hydrophobic organic solvent having a water solubility of 1 g / L or less at 25°C, and adjusting the pH of the extracted water to 3.5 to 6.

0.

9. A method for producing the composition according to claim 8, wherein the linear organopolysiloxane is a linear organopolysiloxane represented by the following formula (2). (In the formula, m is an integer between 0 and 50.) 10. A method for producing the composition according to claim 8, wherein the hydrophilic organic solvent is one or more selected from 1-propanol, 2-propanol, 1-butanol, and isobutanol.

11. A method for producing the composition according to claim 8, wherein the hydrophobic organic solvent is one or more selected from hexane, heptane, octane, cyclohexane, methylcyclohexane, and ethylcyclohexane.

12. A coating agent comprising the composition according to claim 5.

13. An article having a cured coating film of the coating agent according to claim 12.

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