JP4680757B2 - Method for producing surface-treated titanate pigment and surface-treated titanate pigment - Google Patents

Description

  The present invention relates to a method for producing a surface-treated titanate pigment and a surface-treated titanate pigment, and more particularly to a scaly titanate pigment subjected to a hydrophobic surface treatment and a method for producing the same.

  In general, since titanium dioxide pigment has a hydrophilic surface, it is difficult to uniformly disperse the titanium dioxide pigment as it is in a highly hydrophobic mixture. Therefore, by forming a hydrophobic coating on the surface of the titanium dioxide pigment and using the titanium dioxide pigment that has been subjected to the hydrophobic surface treatment, it can be uniformly dispersed in the highly hydrophobic mixture for the first time. became.

  As a method for producing a hydrophobic surface-treated titanium dioxide pigment as described above, for example, in Patent Document 1, a coating layer containing an aluminum phosphate compound is formed on the surface of titanium dioxide particles, and the coating layer is further formed. After the aqueous slurry of titanium dioxide is acidified, an organic silane compound is added and heated to 45 to 100 ° C. above the hydrolysis temperature of the organic silane compound to form an organic silane compound on the coating layer containing the aluminum phosphate compound A method of forming a coating layer containing the hydrolysis product of has been proposed.

  Patent Document 2 proposes a method of hydrophobizing the surface of titanium dioxide particles with siloxanes in advance in order to obtain an aqueous dispersion of ultrafine titanium dioxide using a nonionic surfactant.

International Publication No. 01/019928 Pamphlet JP-A-7-247119

  In recent years, scaly titanate pigments, which are flakes than the titanium dioxide pigment, have attracted attention, and the inventors of the present application, for example, put the titanium dioxide pigment and titanate pigment in the same film thickness respectively. When it is contained, the scaly titanate pigment is more densely aligned in a higher orientation than the titanium dioxide pigment, and thus it has been found that the light resistance and design properties of the resulting coating film are excellent.

  However, as will be described later, titanate pigments are stably present in a scaly form in a solvent in a neutral to alkaline atmosphere, but the scaly titanate pigments aggregate in a solvent in a less neutral to acidic atmosphere. As a result, the ultrathin scale-like characteristics of the titanate pigment having a high aspect ratio are not exhibited. On the other hand, the above-described hydrophobizing treatment for the titanium dioxide pigment is carried out in an acidic solvent. Therefore, the hydrophobizing treatment method for the titanium dioxide pigment is diverted to the surface hydrophobizing treatment of the scaly titanate pigment. However, the surface of the scaly titanate pigment could not be subjected to a hydrophobic surface treatment.

  The present invention has been made in view of the above problems, and provides a surface-treated titanate pigment in which a hydrophobic coating is formed on the surface of a scaly titanate pigment and a method for producing the same.

  The method for producing a surface-treated titanate pigment and the surface-treated titanate pigment of the present invention have the following characteristics.

(1) a sol of flaky titanate pigment, were mixed by adding the surfactant and hydrophobicity, have a step of powdering and lyophilized, the surfactant, nonionic surfactants It is at least one selected from the group consisting of an activator and a titanate surfactant, and the hydrophobicity imparting agent is a method for producing a surface-treated titanate pigment which is a silane coupling agent or a silicone oil .

  The surfactant further promotes the action of the hydrophobicity-imparting agent adsorbing on the surface of the scaly titanate pigment while the sol-like titanate pigment is uniformly dispersed in scaly form. As a result, a necessary amount of the hydrophobicity-imparting agent is adsorbed on the surface of the scaly titanate pigment, and the hydrophobicity-imparting agent is physically adsorbed on the surface of the scaly titanate pigment by a subsequent freeze-drying treatment. As a result, a surface-treated titanic acid pigment having a hydrophobic coating formed on the surface of the titanic acid pigment can be obtained.

  (2) In the method for producing a surface-treated titanate pigment described in (1) above, the powdered surface-treated titanate pigment is further stirred in a mixed solution of a lower alcohol and water and then heated in a vacuum. Process.

  By performing the vacuum heating, the hydrophobicity imparting agent physically adsorbed on the surface of the scaly titanate pigment was fixed (chemical adsorption) to the titanate pigment surface, and a stronger hydrophobic film was formed. A surface-treated titanic acid pigment can be obtained.

  In addition, the powdered and hydrophobic surface-treated titanic acid pigment is redispersed in a mixed solution of lower alcohol and water and then heated in a vacuum to fix the hydrophobic coatings on the pigment surface by heating. As a result, aggregation or agglomeration of the pigments can be prevented.

  As will be described later, the titanate pigment is stably present in a scale-like shape in a solvent in a neutral to alkaline atmosphere. On the other hand, the hydrophobicity-imparting agent adheres to the pigment in a solvent in a neutral to acidic atmosphere. Therefore, by using a nonionic surfactant as the surfactant, it is possible to make only the interface portion between the scaly titanate pigment and the solvent neutral while keeping the titanate pigment in a sol form in the solvent. As a result, adsorption of the hydrophobicity-imparting agent to the scaly titanate pigment surface can be promoted in this neutral range.

  In addition, titanate-based surfactants have a high affinity with titanate pigments and hydrophobicity-imparting agents while keeping the sol-form titanate pigments in the form of scales, so they exist at the interface between titanate pigments and solvents. To do. Further, since the titanate-based surfactant forms a state in which the hydrophobicity-imparting agent is also likely to be present at the interface portion, adsorption of the hydrophobicity-imparting agent to the scaly titanate pigment surface is also promoted.

( 3 ) In the method for producing a surface-treated titanic acid pigment according to ( 1 ) or (2) , the silane coupling agent is selected from the group consisting of an epoxy silane coupling agent and an NCO silane coupling agent. At least one selected.

( 4 ) In the method for producing a surface-treated titanic acid pigment according to ( 1 ) or (2) , the silicone oil is at least one selected from the group consisting of epoxy / silanol-based silicones or amine-based silicones. .

( 5 ) A surface-treated titanate pigment produced using the method for producing a surface-treated titanate pigment according to any one of (1) to ( 4 ) above.

  According to the present invention, a scaly surface-treated titanic acid pigment that has been subjected to a hydrophobic surface treatment can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Method for producing surface-treated titanate pigment]
The surface-treated titanic acid pigment according to a preferred embodiment of the present invention is manufactured by the following manufacturing method.

  First, a sol-like pigment of ultrathin scaly titanic acid is produced as follows. That is, the layered titanate is treated with an acid to form layered titanic acid, and then, as shown in FIG. 1, the organic basic compound is allowed to act to peel the layers.

The layered titanate K _0.8 Li _0.27 Ti _1.73 O ₄ is treated with acid, and the exchangeable metal cation is replaced with hydrogen ion or hydronium ion to form layered titanate (for example, H _1.07 Ti _1.73 O ₄ .nH ₂ O ) Is obtained. An organic basic compound is allowed to act on the layered titanic acid and the layers are peeled to obtain an aqueous medium dispersion (peeled sol) of flaky titanic acid. As the organic basic compound, dimethylethanolamine (DMEA) is desirable.

  As shown in FIG. 1, the flaky titanic acid of the obtained aqueous medium dispersion (peeling sol) is obtained as flaky titanic acid in which about 1 nm of titanic acid is laminated in a single layer or a plurality of layers.

<Synthesis of flaky titanic acid dispersion>
(Synthesis example)
A raw material in which 67.01 g of titanium oxide, 26.78 g of potassium carbonate, 12.04 g of potassium chloride and 5.08 g of lithium hydroxide were pulverized and mixed in a dry process was calcined at 1020 ° C. for 4 hours. 7.9 kg of 10.9% aqueous slurry of the obtained powder was prepared, 470 g of 10% aqueous sulfuric acid solution was added and stirred for 2 hours, and the pH of the slurry was adjusted to 7.0. What was separated and washed with water was dried at 110 ° C. and then calcined at 600 ° C. for 12 hours. The obtained white powder was layered titanate K _0.6 Li _0.27 Ti _1.73 O _3.9 and had an average major axis of 15 μm.

65 g of this layered titanate was dispersed and stirred in 5 kg of 3.5% hydrochloric acid, reacted at 40 ° C. for 2 hours, separated by suction filtration, and washed with water. The obtained layered titanic acid had a K ₂ O remaining amount of 2.0% and a metal ion exchange rate of 94%.

  While dispersing and stirring the total amount of layered titanic acid obtained in 1.6 kg of deionized water, a solution prepared by dissolving 34.5 g of dimethylethanolamine in 0.4 kg of deionized water was added and stirred at 40 ° C. for 12 hours. Thus, a flaky titanic acid dispersion having a pH of 9.9 was obtained. The concentration was adjusted to 5.0% by weight by centrifugation at 10,000 rpm for 10 minutes. The obtained flaky titanic acid dispersion did not show solid sedimentation even after standing for a long time, and the solid content obtained by drying it at 110 ° C. for 12 hours showed a weight loss of 200 ° C. or more by TG / DTA analysis. Was 14.7% by weight, and the interlayer distance was 10.3 mm by XRD analysis.

  The scaly titanic acid obtained as described above has a scaly longitudinal length (particle size) of 10 to 30 μm, and the aspect ratio (thickness and longitudinal length) of the scaly titanic acid. The ratio is from 100 to 30000, preferably from 100 to 600 since the thickness of the scaly titanic acid is from 1 to 100 nm.

  As shown in FIG. 3, the layered titanic acid is intercalated (delaminated) with an amine such as DMEA to form an amine stripping sol (ie, DMEA stripping titanate sol). In particular, when it becomes less than neutral to acidic, and when heated, particularly when heated to 70 ° C. or more, aggregation occurs, and particularly when pH changes, it returns to layered titanic acid. Therefore, it becomes impossible to form a hydrophobic film on the surface of the scaly titanate pigment as shown in FIG. Therefore, in the present invention, in particular, in order to make the surface of the scaly titanate pigment hydrophobic, the pH of only the vicinity of the surface of the titanate pigment is made neutral while keeping the pH of the amine stripping sol in an alkaline atmosphere. The treatment is performed at a temperature at which aggregation does not occur.

  The flaky titanic acid dispersion is a dispersion in which sol-like titanic acid is dispersed in the form of ultrathin scaly, and will be described below using “DMEA exfoliated titanate sol” as an example.

  Next, as shown in FIG. 2, a surfactant and a hydrophobicity-imparting agent are added to and mixed with DMEA exfoliated titanate sol, and then freeze-dried to obtain a surface-treated titanate pigment (S100). .

  The surfactant promotes the action of the hydrophobicity-imparting agent adsorbing on the surface of the scaly titanate pigment while the titanate pigment in the DMEA exfoliated titanate sol is uniformly dispersed in scaly form. As a result, a necessary amount of the hydrophobicity-imparting agent is adsorbed on the surface of the scaly titanate pigment, and the hydrophobicity-imparting agent is physically adsorbed on the surface of the scaly titanate pigment by a subsequent freeze-drying treatment. As a result, a surface-treated titanic acid pigment having a hydrophobic coating formed on the surface of the titanic acid pigment can be obtained.

  The surfactant is at least one selected from the group consisting of a nonionic surfactant and a titanate surfactant, and examples of the nonionic surfactant include sucrose fatty acid ester, sorbitan fatty acid ester, Oxyethylene sorbitan fatty acid ester, fatty acid alkanolamide, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, poly (oxyethylene) = octyl phenyl ether (also known as “Triton X-100”, Cas No. 9002-93-1) Among them, poly (oxyethylene) = octylphenyl ether (also known as “Triton X-100”, Cas No. 9002-93-1) is preferable. In addition, as the titanate-based surfactant, for example, “KR ET” (manufactured by Ajinomoto Fine Techno) of the “Preneact” series is preferable.

  The DMEA exfoliated titanate sol described above is a dispersion in an alkaline atmosphere, and the titanate pigment is stably present in a scale shape in a solvent in a neutral to alkaline atmosphere. On the other hand, the hydrophobicity-imparting agent adheres to the pigment in a solvent in a neutral to acidic atmosphere. Therefore, by using a nonionic surfactant as the surfactant, it is possible to make only the interface portion between the scaly titanate pigment and the solvent neutral while keeping the titanate pigment in a sol form in the solvent. As a result, adsorption of the hydrophobicity-imparting agent to the scaly titanate pigment surface can be promoted in this neutral range.

  In addition, titanate-based surfactants have a high affinity with titanate pigments and hydrophobicity-imparting agents while keeping the sol-form titanate pigments in the form of scales, so they exist at the interface between titanate pigments and solvents. To do. Further, since the titanate-based surfactant forms a state in which the hydrophobicity-imparting agent is also likely to be present at the interface portion, adsorption of the hydrophobicity-imparting agent to the scaly titanate pigment surface is also promoted.

  In addition, various hydrophobicity-imparting agents can be used. For example, siloxanes such as dimethylpolysiloxane, methylhydrogen polysiloxane, organically modified silicone oil, silicone oil (organopolysiloxane), and silane couplings. Agents, coupling agents such as titanate coupling agents, aluminum coupling agents, and fluorine coupling agents.

As the silicone oil of the carbon chain length of 3 or more carbon atoms (C ₃ or higher), at least one selected from the group consisting of epoxy / silanol silicone or amine-based silicone, as the epoxy / silanol silicone For example, “MAC2101” (manufactured by Nihon Unicar) is preferable, and as the amine-based silicone, for example, “FZ4658” (manufactured by Nihon Unicar) is preferable.

  The silane coupling agent is at least one selected from the group consisting of epoxy silane coupling agents and NCO silane coupling agents. Examples of the epoxy silane coupling agent include γ-glycol. Sidoxypropyltrimethoxysilane (for example, “KBM403” (manufactured by Shin-Etsu Chemical Co., Ltd.)) is preferable. As the NCO silane coupling agent, for example, 3-isocyanatopropyltrimethoxysilane (for example, “KBE9007” ( Shin-Etsu Chemical Co., Ltd.)) is preferred.

  The concentration of the sol-like titanic acid pigment in the flaky titanic acid dispersion is 1 to 5% by weight, preferably 3 to 5% by weight. When the concentration exceeds 5% by weight, the viscosity of the flaky titanic acid dispersion becomes too high, and the hydrophobicity imparting agent is sufficiently adsorbed on the surface of the flaky titanic acid pigment even when the surfactant is added. There is a risk that it will not be possible.

  The weight ratio of the titanate pigment to the surfactant is preferably 1 to 50% by weight, more preferably 3 to 30% by weight based on the titanate pigment solid content. When the amount of the surfactant is too small outside the above weight ratio range, the interface between the titanate pigment and the dispersion is not sufficiently neutral, so that a sufficient amount of hydrophobicity imparting agent for the titanate pigment is obtained. Is not physically adsorbed and a pigment having a desired hydrophobicity cannot be obtained. On the other hand, if it is outside the above weight ratio range and the amount of the surfactant is too large, the freeze-drying time may be prolonged because the titanate pigment is powdered in the next step.

  The weight ratio between the hydrophobicity-imparting agent and the surfactant is preferably 9: 1 to 9: 5. When the amount of the surfactant is too much outside the above weight ratio range, the freeze-drying time may be prolonged because the titanate pigment is powdered in the next step. On the other hand, when the amount of the hydrophobicity-imparting agent is outside the above weight ratio range and is too large, the amount of the hydrophobicity-imparting agent over the amount required for the titanate pigment surface is added, which is economically undesirable. .

  Examples of the stirring device for adding and stirring the surfactant and the hydrophobicity-imparting agent to the flaky titanic acid dispersion (for example, DMEA exfoliated titanate sol) include a blade-type stirrer, a disper, a homomixer, etc. Any stirrer may be used as long as the hydrophobicity imparting agent has a stirring force that does not cause separation due to the shear stress of stirring after the hydrophobic imparting agent is physically adsorbed on the surface of the scaly titanate pigment. it can.

  Next, after the hydrophobicity imparting agent is physically adsorbed on the surface of the scaly titanate pigment in the dispersion, the dispersion is 5 to 20 at room temperature (25 ° C.) under a reduced pressure of 4 to 5 Pa. Freeze-dry for hours. As an apparatus for performing the freeze-drying, for example, a freeze-dryer “FDU-2000” (manufactured by Tokyo Rika Machinery Co., Ltd.) can be used.

  The water content of the surface-treated titanic acid pigment after the freeze-drying treatment is preferably 0.1 ppm or less. The water content was measured using the Karl Fischer method, for example, using an automatic moisture measuring device “AQV-7” (manufactured by Hiranuma Sangyo Co., Ltd.).

  Next, as shown in FIG. 2, the surface-treated titanic acid pigment pulverized by freeze-drying is stirred in a mixed solution of lower alcohol and water, and then heated in a vacuum.

  By performing the vacuum heating, the hydrophobicity imparting agent physically adsorbed on the surface of the scaly titanate pigment was fixed (chemical adsorption) to the titanate pigment surface, and a stronger hydrophobic film was formed. A surface-treated titanic acid pigment can be obtained. In addition, the powdered and hydrophobic surface-treated titanic acid pigment is redispersed in a mixed solution of lower alcohol and water and then heated in a vacuum to fix the hydrophobic coatings on the pigment surface by heating. As a result, aggregation or agglomeration of the pigments can be prevented.

  As the lower alcohol, an alcohol having 4 or less carbon atoms is preferable. For example, any one of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, and butyl alcohol or a combination thereof can be used.

  The weight ratio of the lower alcohol to water in the mixed solution is preferably 1: 1 to 1: 3, and it is desirable to appropriately select the weight ratio according to the type of the lower alcohol. When the amount is lower than the above weight ratio and the amount of the lower alcohol is too large, the powdered titanate pigment is not dispersed in the mixed solution and aggregates. On the other hand, if it is out of the above weight ratio range and the amount of water is too large, the vacuum drying time in the next step may be prolonged.

  As the stirring device used for redispersing the powdered surface-treated titanate pigment in the mixed solution, the above-described stirring device can be used. Here, the concentration of the surface-treated titanic acid pigment that can be redispersed in the mixed solution is preferably 3 to 5% by weight. When the concentration is exceeded, the viscosity of the redispersion liquid becomes too high, and the powdered surface-treated titanic acid pigment may not be uniformly redispersed.

Next, after filtering the re-dispersed liquid and washing the obtained surface-treated titanate pigment, the hydrophobicity imparting agent physically adsorbed on the surface of the powdered surface-treated titanate pigment is obtained by heating in vacuum. Chemical adsorption (fixation) on the titanate pigment surface. Here, vacuum heating is 400-20000 Pa, Comprising: It is preferable to heat to the temperature of room temperature (25 degreeC)-80 degreeC. As hydrophobicity, for example, dimethyl polysiloxane, methyl hydrogen polysiloxane, an organic modified silicone oil, when the carbon chain length is a silicone oil or a silane coupling agent having 3 or more carbon atoms (C ₃ or higher) A hydrophobic film having a siloxane bond as shown in FIG. 4 is formed on the surface of the scaly titanate pigment.

  Further, when redispersion and vacuum heating are performed after the freeze-drying described above, the weight ratio of the hydrophobicity-imparting agent and the surfactant can be 9: 1 to 1: 3, and vacuum Compared with the surface treatment only with drying, the amount of the hydrophobicity-imparting agent added can be reduced. In addition, when it is outside the range of the above weight ratio and the amount of the surfactant is too large, there is a possibility that the vacuum heating time will be prolonged. On the other hand, when the amount of the hydrophobicity-imparting agent is outside the above weight ratio range and is too large, the amount of the hydrophobicity-imparting agent over the amount required for the titanate pigment surface is added, which is economically undesirable. .

[Surface treatment titanate pigment]
The surface-treated titanic acid pigment according to a preferred embodiment of the present invention is produced by the production method described above. Further, in the surface-treated titanate pigment of the present embodiment, as shown in FIG. 4, a film made of a compound having a siloxane bond (Si—O bond) was formed on the surface of the scaly titanate pigment substrate. Pigment.

  Hereinafter, the surface-treated titanate pigment of the present invention will be described with reference to examples. The addition amount of the surfactant and the hydrophobicity imparting agent to the titanate sol is% by weight with respect to the titanate solid content.

Example 1.
As shown in FIG. 2, a DMEA exfoliated titanate sol having a scaly titanate pigment concentration of 5% by weight, poly (oxyethylene) = octylphenyl ether (also known as “Triton X-100”, Cas No. 9002-93-1) is added by 4% by weight, and γ-glycidoxypropyltrimethoxysilane (“KBM403” (manufactured by Shin-Etsu Chemical Co., Ltd.)) as an epoxy silane coupling agent is added by 36% by weight, and a conditioning mixer is added. After stirring for 5 minutes ("Rotating: 800 rpm, Revolving: 2000 rpm)" using "(Foam removal Nitataro AR250" (Sinky Co., Ltd.)), defoaming (Rotating: 60 rpm, Revolving: 2200 rpm) was performed. Went for a minute.

  The sol after the agitation adsorption reaction was freeze-dried "FDU-2000" (manufactured by Tokyo Rika Kikai Co., Ltd.) at room temperature (25 ° C) at a pressure of 4-5 Pa, and an externally provided volatile solution trap was -80 ° C. The surface-treated dry titanic acid obtained by lyophilization for 18 hours while removing the solution, removing the solution (mainly water) in the sol, and adsorbing the surfactant and epoxysilane coupling agent used on the surface. A powder pigment (A) [no heat treatment] was obtained.

Examples 2-4.
According to Example 1, except that the epoxy silane coupling agent used in Example 1 was changed to the NCO silane coupling agent or silicone oil shown in Table 1, the surface-treated dry titanate powder pigment (A) [ Without heat treatment].

Examples 5-8.
In accordance with Examples 1 to 5, except that the amount of poly (oxyethylene) = octylphenyl ether added as the surfactant used in Examples 1 to 4 was changed from 4% by weight to 20% by weight. A dry titanic acid powder pigment (B) [no heat treatment] was obtained.

Examples 9-12.
Except that poly (oxyethylene) = octylphenyl ether as the surfactant used in Examples 6 to 10 was changed to “KR ET” (manufactured by Ajinomoto Fine-Techno Co., Ltd.) of “Preneact” series which is a titanate surfactant. In accordance with Examples 5 to 8, surface-treated dry titanic acid powder pigment (C) [no heat treatment] was obtained.

Example 13
As shown in FIG. 2, a DMEA exfoliated titanate sol having a scaly titanate pigment concentration of 5% by weight, poly (oxyethylene) = octylphenyl ether (also known as “Triton X-100”, Cas No. 9002-93-1) is added by 20% by weight, and γ-glycidoxypropyltrimethoxysilane (“KBM403” (manufactured by Shin-Etsu Chemical Co., Ltd.)) as an epoxy silane coupling agent is added by 7% by weight, and a conditioning mixer is added. After stirring for 5 minutes ("Rotating: 800 rpm, Revolving: 2000 rpm)" using "(Foam removal Nitataro AR250" (Sinky Co., Ltd.)), defoaming (Rotating: 60 rpm, Revolving: 2200 rpm) was performed. Went for a minute.

  The sol after the agitation adsorption reaction was freeze-dried "FDU-2000" (manufactured by Tokyo Rika Kikai Co., Ltd.) at room temperature (25 ° C) at a pressure of 4-5 Pa, and an externally provided volatile solution trap was -80 ° C. The surface-treated dry titanic acid obtained by lyophilization for 18 hours while removing the solution, removing the solution (mainly water) in the sol, and adsorbing the surfactant and epoxysilane coupling agent used on the surface. A powder pigment (D) [no heat treatment] was obtained.

The surface-treated dry titanic acid powder pigment (D) [no heat treatment] was added to a mixed solution of ethyl alcohol: H ₂ O = 1: 1 (weight ratio) so as to be 5% by weight. After using a conditioning mixer ("Awatake Kentaro AR250" (manufactured by Sinky Co., Ltd.)), stirring (rotation: 800 rpm, revolution: 2000 rpm) at 25 ° C. for 15 minutes, and filtering and washing the resulting slurry Then, drying is performed for 12 hours while pulling at 2800 Pa with an aspirator at room temperature (25 ° C.). Thereafter, the pressure is reduced to 1000 Pa using a vacuum pump, and vacuum heating is performed at 80 ° C. for 2 hours. With heat treatment].

Examples 14-16.
According to Example 13, except that the epoxysilane coupling agent used in Example 13 was changed to an NCO silane coupling agent or silicone oil shown in Table 1, respectively, the surface-treated dry titanate powder pigment (E) [ With heat treatment].

Examples 17-20.
As the surfactant used in Examples 13 to 16, the addition amount of poly (oxyethylene) = octylphenyl ether was changed from 20% by weight to 4% by weight, and the silane-based cups shown in Table 1 used in Examples 13 to 16 were used. A surface-treated dry titanic acid powder pigment (F) [with heat treatment] was obtained in accordance with Examples 13 to 16 except that the amount of ring agent or silicone oil added was changed from 7% by weight to 36% by weight.

Examples 21-24.
Except that poly (oxyethylene) = octylphenyl ether as the surfactant used in Examples 13 to 16 was changed to “KR ET” (manufactured by Ajinomoto Fine-Techno Co., Ltd.) of “Preneact” series which is a titanate surfactant. In accordance with Examples 13 to 16, surface-treated dry titanic acid powder pigment (G) [with heat treatment] was obtained.

Comparative Example 1
36 gamma-glycidoxypropyltrimethoxysilane ("KBM403" (manufactured by Shin-Etsu Chemical Co., Ltd.)) as an epoxy silane coupling agent was added to DMEA exfoliated titanate sol having a scaly titanic acid pigment concentration of 5% by weight. % By weight was added, and stirring (autorotation: 800 rpm, revolution: 2000 rpm) was performed for 5 minutes using a conditioning mixer ("Awatake Kentaro AR250" (manufactured by Shinky Co., Ltd.)). Thereafter, the titanate sol was adjusted to pH 3, the precipitated aggregate was filtered and separated, and the separated pigment was vacuum dried at 80 ° C. for 2 hours to obtain a titanate pigment (H).

Comparative Example 2
36 gamma-glycidoxypropyltrimethoxysilane ("KBM403" (manufactured by Shin-Etsu Chemical Co., Ltd.)) as an epoxy silane coupling agent was added to DMEA exfoliated titanate sol having a scaly titanic acid pigment concentration of 5% by weight. % By weight, and using a conditioning mixer ("Nawataro Kentaro AR250" (manufactured by Sinky Corp.)), stirring at room temperature (25 ° C) (rotation: 800 rpm, revolution: 2000 rpm) for 5 minutes, This sol solution was freeze-dried to obtain titanate pigment (I).

  Surface-treated dry titanic acid powder pigment (A) [without heat treatment] obtained from Examples 1 to 24 to surface-treated dry titanic acid powder pigment (G) [with heat treatment], and titanate pigments of Comparative Examples 1 and 2 (H) and (I) were stirred for 5 to 10 minutes using the above conditioning mixer, dispersed in water, resolded, and mixed with a base resin (base resin) to form a paint.

  Next, a coating film was formed using the pigments described in the above Examples and Comparative Examples, and the coating film adhesion test, particularly the water resistance adhesion test was performed. The coating materials used for forming the coating film shown in FIG. 5 are as follows. As the intermediate coating material, a coating material using a polyester resin and a melamine resin as a base resin was used. Moreover, surface treatment dry titanic acid powder from the surface treatment dry titanic acid powder pigment (A) [no heat treatment] obtained in Examples 1 to 24 described above was used as a base coating material with an acrylic resin and a melamine resin as a base resin. Pigment (G) [with heat treatment], and paint containing titanate pigments (H) and (I) of Comparative Examples 1 and 2 at a content ratio PWC (pigment wright content: solid content to paint resin) of 20% Using. Further, as the clear paint, a paint containing three kinds of base resin composed of acrylic resin / melamine resin / acid acrylic resin / epoxy resin / 2-component urethane resin was used.

  The method for forming a coating film using the pigments described in the present examples and comparative examples will be described with reference to FIGS. First, an intermediate coating without pigment was applied to an electrodeposited steel sheet so as to have a film thickness of 35 μm, and baked at a maximum temperature of 140 ° C. for 18 minutes. Next, the surface-treated scale-like titanate pigment-containing base paint is applied with a film thickness of 13 μm when the base paint is an aqueous base paint, and is applied with a film thickness of 15 μm when the base paint is a solvent-based base paint. did. Here, when a water-based base paint was used, preheating was performed for 10 minutes at a maximum temperature of 80 ° C., and when a solvent-based base paint was used, a flash time was provided for 1 minute. Here, the flash time refers to the time from applying the base paint to applying the clear paint. Thereafter, a clear paint was applied on the base coating film so as to have a film thickness of 35 μm, and baked by holding at a maximum reached temperature of 140 ° C. for 18 minutes. As a result, two tests were conducted in which the intermediate coating film 10, the titanate pigment-containing base coating film 12, and the clear coating film 14 were sequentially laminated to form two types of multilayer coating films using aqueous and solvent-based base coatings. I got a piece.

  The titanate pigment-containing base coating film 12 in the multi-layer coating film formed as described above has a highly oriented surface-like scaly titanate pigment as a very large number of pigments, as shown in FIG. It can be seen that the coating film exists in a densely arranged state.

[Coating adhesion test evaluation method]
The coating film adhesion test evaluation method shown below performs the “water resistance adhesion test” shown below, and then uses the following “cross-cut test method” to determine the superiority or inferiority of the adhesion of the coating film to the fabric. Examined.

(Water adhesion test)
A constant temperature water tank is also filled with distilled water or deionized water and kept at 40 ° C. (or 80 ° C.) so that at least half of the test piece is immersed in water. When testing two or more specimens with consent, the test specimens were spaced so as not to contact during the test. Remove the test piece that has been tested for the specified time (240 hours at 40 ° C, 1 hour at 80 ° C) from the water tank, wipe off water droplets / contamination with a cloth (waste), and so on. Then, the presence of peeling, gloss reduction, and discoloration is examined, and a cross cut test is performed within 1 hour at room temperature.

(Cross-cut test method)
(1) Preparation of test piece The test piece is prepared by coating and drying by the method described above.

(2) Cutting the grids A cutter knife is vertically applied to the surface of the test piece, and 11 parallel lines that reach the substrate are drawn, and 11 parallel lines that intersect these parallel lines are drawn. Draw 100 squares surrounded by 4 straight lines. The interval between the parallel lines is 1 mm.

(3) Peeling test At a temperature of 20 ± 2 ° C. and a humidity of 65 ± 5%, the adhesive tape (width 24 mm) is uniformly crimped with a fingertip so as not to include bubbles on the surface when the cross section of the test piece is cut. At this time, do not press the adhesive tape strongly with your nails. Hold one end of the adhesive tape and pull it abruptly to peel the tape from the specimen. The pulling direction is as shown in FIG. In principle, a translucent pressure-sensitive adhesive tape (width: 24 mm) (here, Nichibansello tape (registered trademark) L pack 24) having an adhesive strength of 0.44 ± 0.05 kgf / mm was used as the adhesive tape.

(4) Evaluation The number of peeled surfaces of 50% or more of each square coating film and the interface where the peeling occurred are examined.

  The evaluation results are shown in Tables 1 and 2 below. In addition, about the comparative example, it evaluated visually also about the designability of the obtained pigment, and the result was shown in Table 2.

註)
* 1: Epoxysilane coupling agent; γ-glycidoxypropyltrimethoxysilane “KBM403” (manufactured by Shin-Etsu Chemical Co., Ltd.)
* 2: NCO silane coupling agent; 3-isocyanatopropyltrimethoxysilane “KBE9007” (manufactured by Shin-Etsu Chemical Co., Ltd.)
* 3: Epoxy / silanol-based silicone; “MAC2101” (Nihon Unicar)
* 4: Amine-based silicone; “FZ4658” (manufactured by Nihon Unicar)

  As shown in Tables 1 and 2, it was found that the multilayer coating film having the titanate pigment surface-treated according to the present invention exhibits excellent water resistance.

  The method for producing a surface-treated titanate pigment and the surface-treated titanate pigment of the present invention are effective in any application as long as they are used to form a water-resistant coating film. In particular, as a coating film for a vehicle, it can be used for forming a coating film for a vehicle exterior.

It is a figure explaining one aspect | mode of the preparation method of the sol used for the manufacturing method of the surface treatment titanate pigment of this invention. It is a flowchart of the process of 1 aspect of the manufacturing method of the surface treatment titanate pigment of this invention. It is a figure explaining the state which the amine peeling sol which is a sol of scaly titanic acid returns to layered titanic acid. It is a schematic diagram of the surface treatment state of the surface treatment titanate pigment of this invention. It is a figure explaining the structure of an example of the multilayer coating film for evaluating the surface treatment titanate pigment of this invention. It is a flowchart which shows an example of the formation process of the multilayer coating film using the surface treatment titanate pigment of this invention. It is the scanning microscope picture which image | photographed the cross section of the base coating film containing the surface treatment titanate pigment of this invention. It is a figure explaining the peeling operation | work in a cross cut test method.

Explanation of symbols

  10 intermediate coating film, 12 base coating film, 14 clear coating film.

Claims (5)

The sol-like flaky titanate pigment, were mixed by adding the surfactant and hydrophobicity, have a step of powdering and lyophilized,
The surfactant is at least one selected from the group consisting of a nonionic surfactant and a titanate surfactant,
The method for producing a surface-treated titanic acid pigment, wherein the hydrophobicity imparting agent is a silane coupling agent or silicone oil . In the manufacturing method of the surface treatment titanate pigment of Claim 1,
The method for producing a surface-treated titanate pigment further comprises a step of stirring the powdered surface-treated titanate pigment in a mixed solution of lower alcohol and water, followed by vacuum heating. In the manufacturing method of the surface treatment titanate pigment of Claim 1 or Claim 2 ,
The method for producing a surface-treated titanate pigment, wherein the silane coupling agent is at least one selected from the group consisting of an epoxy silane coupling agent and an NCO silane coupling agent. In the manufacturing method of the surface treatment titanate pigment of Claim 1 or Claim 2 ,
The method for producing a surface-treated titanic acid pigment, wherein the silicone oil is at least one selected from the group consisting of epoxy / silanol-based silicones or amine-based silicones. The surface treatment titanate pigment manufactured using the manufacturing method of the surface treatment titanate pigment of any one of Claims 1-4 .