JP7148264B2 - Release agent for tire inner surface, release agent aqueous dispersion for tire inner surface, method for producing release agent for tire inner surface, method for producing tire, and tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a release agent for tire inner surface, an aqueous dispersion of the release agent for tire inner surface, a method for producing the release agent for tire inner surface, a method for producing a tire, and a tire.

One type of release agent for rubber is a release agent for the inner surface of a tire. For example, Patent Document 1 describes a release agent for tire inner surface containing an inorganic component (inorganic powder) made of powder, a silicone component, a surfactant, a polyhydric alcohol, and water.

JP 2012-228783 A

The release agent for tire inner surface is used in the following manner, for example, in the process of vulcanizing and molding an unvulcanized green tire, which is part of the tire manufacturing process. First, in the vulcanization molding step, for example, a rubber bag called a bladder is placed inside an unvulcanized green tire, and the bladder is inflated with hot air, hot water, or steam. As a result, the unvulcanized raw tire is pressed against the inside of the mold. In this state, the unvulcanized raw tire is vulcanized along with press-fitting. In order to smoothly carry out this vulcanization molding process, a release agent for tire inner surface is previously spray-coated on the inner liner surface (inner surface) of the unvulcanized raw tire. The release agent for tire inner surface is previously dispersed in water in a dedicated tank and stored as an aqueous dispersion for several days, for example. After being stored, the release agent for tire inner surface is redispersed in water and used.

It is extremely inefficient to prepare (manufacture) the release agent for tire inner surface each time immediately before use. Therefore, the release agent for tire inner surface is prepared in advance and stored for several days, for example, as described above. Therefore, it is important for the tire inner surface release agent to maintain performance after long-term storage. Specifically, for example, in a dispersion liquid of a release agent for the inner surface of a tire, it is important to suppress sedimentation of surface hydrophilic non-swelling inorganic powder such as mica (mica), which is a release component (release agent).

In the mold release agent for tire inner surface, for example, silicone oil is coated on the surface of mica in order to suppress sedimentation of mica. However, since surface-hydrophilic non-swelling inorganic powders such as mica have a low ability to support silicone oil on the surface, the silicone oil may separate when the tire inner surface release agent dispersion is stored for a long period of time. There is Then, after the dispersion liquid is spray-coated, oil spots that cause poor appearance may occur.

Therefore, the present invention provides a tire inner surface mold release agent that can suppress or prevent the occurrence of oil spots even after long-term storage, a tire inner surface mold release agent aqueous dispersion, and a method for producing a tire inner surface mold release agent. An object of the present invention is to provide a tire manufacturing method and a tire.

In order to achieve the above object, the tire inner surface release agent of the present invention is a tire inner surface release agent comprising a release agent and a surfactant, wherein the release agent is a surface hydrophilic non-swelling It contains an inorganic powder and silicone, the surface of the surface-hydrophilic non-swelling inorganic powder is hydrophobized by a surface-hydrophobizing agent, and the silicone is present on the surface of the surface-hydrophilic non-swelling inorganic powder. It is characterized by being non-reactive to

The tire inner surface releasing agent aqueous dispersion of the present invention is characterized by containing the tire inner surface releasing agent of the present invention and water.

The method for producing a tire inner surface release agent of the present invention comprises a hydrophobization step of hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder with the surface hydrophobizing agent, the release agent, the surfactant, and and a mixing step of mixing the lubricant.

The method for manufacturing a tire of the present invention includes a mold release pretreatment step of applying the tire inner surface release agent aqueous dispersion of the present invention to the inner surface of an unvulcanized rubber raw tire, and further volatilizing water; After the release pretreatment step, the bladder housed in the green tire is expanded in the mold to press the outer surface of the green tire against the inner surface of the mold, and in this state, the green tire is heated and applied. and a vulcanization step of vulcanizing.

The tire of the present invention is characterized in that the tire inner surface release agent of the present invention adheres to the tire inner surface. Alternatively, the tire of the present invention is characterized in that the tire inner surface release agent of the present invention is adhered to the inner surface of a green tire and vulcanized.

According to the release agent for tire inner surface, the aqueous dispersion of the release agent for tire inner surface, the method for producing the release agent for inner tire surface, the method for producing tire, and the tire of the present invention, oil spots are prevented even after long-term storage. can suppress or prevent the occurrence of

Hereinafter, the present invention will be described more specifically with reference to examples. However, the invention is not limited by the following description.

The tire inner surface release agent of the present invention may, for example, further contain a lubricant.

In the release agent for tire inner surface of the present invention, for example, the surface hydrophilic non-swelling inorganic powder may contain mica. The mica may be a part of the surface-hydrophilic non-swelling inorganic powder, or may be the whole (total amount).

The surface hydrophobizing agent may be, for example, at least one selected from the group consisting of modified silicones, silanes having reactive groups, and silane coupling agents.

The surface hydrophobizing agent may be, for example, at least one selected from the group consisting of amino-modified silicones, epoxy-modified silicones, hydrogen-modified silicones, silanes having reactive groups, and silane coupling agents.

The release agent for tire inner surface of the present invention is, for example, the surface hydrophilic non-swelling inorganic powder surface non-reactive silicone which is hydrophobized by the surface hydrophobizing agent. It may adhere to the surface of the powder.

The tire inner surface release agent of the present invention may, for example, further contain a surface-hydrophobic inorganic powder. Moreover, non-reactive silicone with respect to the surface of the surface-hydrophilic non-swelling inorganic powder may adhere to the surface of the surface-hydrophobic inorganic powder.

The method for producing a tire inner surface release agent of the present invention further comprises, prior to the mixing step, silicone non-reactive with respect to the surface of the hydrophilic non-swelling inorganic powder, and at least part of the surfactant. It may include a pre-mixing step of mixing with.

[1. Release agent for tire inner surface]
Each component in the tire inner surface release agent of the present invention is not particularly limited, and examples thereof are as follows.

[1-1. Release agent (release component)]
As described above, the tire inner surface release agent of the present invention contains a release agent (release component). In the following description, the releasing agent (releasing component) may be referred to as releasing agent (R) or component (R) for convenience. As described above, the release agent (R) comprises a surface-hydrophilic non-swelling inorganic powder hydrophobized by a surface-hydrophobizing agent and a non-reactive silicone to the surface of the surface-hydrophilic non-swelling inorganic powder. including. Hereinafter, in the release agent (R), the surface hydrophilic non-swelling inorganic powder is referred to as surface hydrophilic non-swelling inorganic powder (A) or component (A), and the surface hydrophobizing agent is surface hydrophobic. The agent (B) or component (B) is used to add non-reactive silicone to the surface of the surface hydrophilic non-swelling inorganic powder surface to component (C) or the surface hydrophilic non-swelling inorganic powder surface. It is called reactive silicone (C). Alternatively, the surface hydrophilic non-swelling inorganic powder (A) hydrophobized by the surface hydrophobizing agent (B) may be treated with the component (AB) or the surface hydrophilic non-swelling inorganic powder hydrophobized by the surface hydrophobizing agent. (AB). The respective components in the release agent (R) are not particularly limited, but are, for example, as follows.

[1-1-1. Surface hydrophilic non-swelling inorganic powder (AB) hydrophobized by a surface hydrophobizing agent]
The component (AB) is, as described above, a surface hydrophilic non-swelling inorganic powder (AB) hydrophobized with a surface hydrophobizing agent. That is, in the release agent for tire inner surface of the present invention, the surface of the surface hydrophilic non-swelling inorganic powder (A) is hydrophobized by the surface hydrophobizing agent (B). As a result, the oil (hydrophobic component) is less likely to separate even after long-term storage of the tire inner surface release agent dispersion. Therefore, according to the present invention, as described above, it is possible to suppress or prevent the occurrence of oil spots.

The surface hydrophilic non-swelling inorganic powder (A), the surface hydrophobizing agent (B), and the method for producing the component (AB) using them are not particularly limited, but are as follows.

[1-1-1-1. Surface hydrophilic non-swelling inorganic powder (A)]
In the component (AB), the surface-hydrophilic non-swelling inorganic powder (A) (component (A)) is not particularly limited. acids and the like. Component (A) may contain mica, as described above. Further, the mica may be a part of the component (A), or may be the whole (total amount). In the following, when the component (A) contains mica, the mica may be referred to as mica (A). In the present invention, mica (A) is not particularly limited. Examples of the mica (A) include muscovite, sericite, muscovite, biotite, phlogopite, illite, color mica, and the like. The mica (A) may contain only one type of mica, or two or more types of mica may be used in combination.

The amount of the surface-hydrophilic non-swelling inorganic powder (A) or mica (A) used in the production of the tire inner surface release agent of the present invention is not particularly limited. 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, relative to the total mass of all components other than water in the agent, 60% by mass or less, It may be 55% by mass or less, 50% by mass or less, 45% by mass or less, or 40% by mass or less.

As described above, the mica (A) is not particularly limited, but mica having an L ^* value of less than 90 is preferable from the viewpoint of suppressing whitening of the inner surface of the tire and improving the appearance of the inner surface of the tire. In the present invention, the L ^* value is based on the L ^* a ^* b ^* color system (CIE1976 (L ^* a ^* b ^* ) color system standardized by the International Commission on Illumination (CIE) in 1976. (See JIS Z 8729.) This L ^* value can be measured, for example, by the following method.

(Method for measuring L ^* value of mica (A))
Mica (A) is placed in a glass cell, L ^* value is measured three times in reflection mode with Color meter ZE6000 (product name of Nippon Denshoku Industries Co., Ltd.), and the average value is calculated.

Examples of mica having an L ^* value of less than 90 include, but are not limited to, biotite, phlogopite, illite, and colored mica. Examples of chemical structural formulas of biotite, phlogopite and illite and L ^* values measured by the above method are shown in Table 1 below.

The mica (A) may contain mica having an L ^* value of less than 90, may not contain mica, or may consist of mica having an L ^* value of less than 90. Further, the mica (A) may have an L ^{* value of less than 90 or an L* value} of 90 or more as a whole by using two or more types of mica in combination. As described above, from the viewpoint of suppressing the whitening of the inner surface of the tire and improving the appearance of the inner surface of the tire, it is preferable that the L ^* value of the mica (A) as a whole is less than 90. The L ^* value of the mica (A) as a whole may be, for example, less than 86, 83 or less, or 75 or less. The lower limit of the L ^* value is not particularly limited, and may be, for example, 5 or more, 10 or more, or 15 or more.

Also, the mica (A) may be, for example, mica containing magnesium. For example, biotite and phlogopite shown in Table 1 above correspond to this. In addition, although not shown in one example of the chemical structural formula shown in Table 1, the aforementioned illite may also contain magnesium. If the mica (A) is magnesium-containing mica, for example, the appearance can be further improved.

In addition, in the surface-hydrophilic non-swelling inorganic powder (A), "non-swelling" means that it hardly swells in water or an organic solvent. Specifically, in the present invention, that the inorganic powder is "non-swelling" means that the swelling power in water or an organic solvent is less than 5 mL/2 g, and in particular, the swelling power in water is less than 5 mL/2 g. It means less than 5mL/2g.
The "swelling power" in the present invention can be measured by the Japan Bentonite Industry Association Standard Test Method: Bentonite (Granular) Swelling Test Method (JBAS-104-77).

[1-1-1-2. Surface Hydrophobizing Agent (B)]
The surface hydrophobizing agent (B) (component (B)) is not particularly limited, but examples thereof include modified silicones, silanes having reactive groups, and silane coupling agents, as described above. Examples of the modified silicone include amino-modified silicone, epoxy-modified silicone, and hydrogen-modified silicone, as described above. Hydrogen-modified silicone is also called "hydrogen silicone". In addition, the surface hydrophobizing agent (B) may contain only one type of surface hydrophobizing agent, or two or more types of surface hydrophobizing agents may be used in combination.

The modified silicone, the silane having a reactive group, and the silane coupling agent are not particularly limited. may An example will be described below.

The modified silicone may be, for example, a compound obtained by introducing a functional group into silicone. The silicone is not particularly limited, but may be, for example, polysiloxane. In general, one with a relatively low molecular weight is referred to as "polysiloxane" and one with a relatively high molecular weight is referred to as "silicone" in some cases, but in the present invention, there is no particular distinction. The silicone may be represented, for example, by the following chemical formula (1).

In the chemical formula (1), R is a substituent, such as a hydrocarbon group. Moreover, each R may be the same or different. For example, all R in the chemical formula (1) may be a hydrocarbon group, and in this case each R may be the same or different. The hydrocarbon group may, for example, be linear or branched, saturated or unsaturated, and may or may not contain a cyclic structure. The cyclic structure may be, for example, a non-aromatic ring or an aromatic ring. The number of carbon atoms in the hydrocarbon group may be, for example, 1 or more, 2 or more, or 3 or more, or may be 22 or less, 18 or less, 10 or less, or 8 or less. R can be, for example, a linear or branched alkyl group or an aromatic substituent. The number of carbon atoms in the linear or branched alkyl group may be, for example, 1 or more, 2 or more, or 3 or more, or 18 or less, 10 or less, or 8 or less. Examples of the linear or branched alkyl group include methyl group, ethyl group, normal propyl group, isopropyl group, butyl group and the like. The number of carbon atoms in the aromatic substituent may be, for example, 6 or more, or 18 or less. Examples of the aromatic substituent include phenyl group, 1-naphthyl group, 2-naphthyl group, tristyrenated phenyl group and the like.

In the chemical formula (1), l is the degree of polymerization and is an arbitrary positive integer. l may be, for example, 1 or more, 2 or more, 3 or more, or 2000 or less, 1000 or less, 500 or less, or 400 or less.

The silicone may be, for example, dimethylsilicone (dimethylpolysiloxane). The dimethylsilicone is, for example, a compound in which, in the chemical formula (1), all Rs other than the terminal are methyl groups, or a compound in which all Rs including the terminal are methyl groups.

The modified silicone may be, for example, a compound in which at least part of R in the chemical formula (1) is replaced with an organic group or a hydrogen atom. Since the hydrogen atom is a hydrogen atom directly bonded to a silicon atom, it functions as, for example, a reactive functional group. Examples of the modified silicone include side chain type, both end type, single end type, and side chain both end type modified silicones, and one type may be used alone or two or more types may be used in combination.

The side chain type modified silicone is represented, for example, by the following chemical formula (2).

In the chemical formula (2), R is the same as R in the chemical formula (1). Q is an organic group or a hydrogen atom. When Q is plural, it may be the same or different. m is the degree of polymerization and is any positive integer. m may be, for example, 1 or more, 5 or more, 10 or more, 15 or more, or 20 or more, or may be 5000 or less, 3000 or less, 1000 or less, or 800 or less. n is the degree of polymerization and is any positive integer. n may be, for example, 1 or more, 5 or more, 10 or more, or 20 or more, or may be 5000 or less, 3000 or less, 1000 or less, or 800 or less.
Moreover, the structure of the modified silicone represented by the chemical formula (2) may be a block copolymer or a random copolymer. That is, Q may exist at any position other than the terminal in the modified silicone of the chemical formula (2). Moreover, when there are multiple Qs, the Qs may be adjacent to each other or may be separated from each other.

The double-ended modified silicone is represented, for example, by the following chemical formula (3).

In the chemical formula (3), R and l are the same as in the chemical formula (1). Moreover, Q is an organic group or a hydrogen atom, and each Q may be the same or different.

The single-ended modified silicone is represented, for example, by the following chemical formula (4).

In the chemical formula (4), R and l are the same as in the chemical formula (1). Also, Q is an organic group or a hydrogen atom.

The modified silicone having both side chain ends is represented by the following chemical formula (5), for example.

In the chemical formula (5), R is the same as R in the chemical formula (1). Q is an organic group or a hydrogen atom, and each Q may be the same or different. m and n are the same as in the chemical formula (2). Moreover, the structure of the modified silicone represented by the chemical formula (5) may be a block copolymer or a random copolymer. That is, in the modified silicone of the chemical formula (5), the Qs other than the terminals may be present at any position, and when there is a plurality of Qs, they may be adjacent to each other or separated from each other.

The amino-modified silicone is not particularly limited, and may be, for example, a monoamine type or a diamine type. In the monoamine type, for example, in the chemical formulas (1) to (5), the organic group (eg, Q in the chemical formulas (2) to (5)) is a group represented by the following chemical formula (6). There may be. In the diamine type, for example, in the chemical formulas (1) to (5), the organic group may be a group represented by the following chemical formula (7). Also, the groups represented by the following chemical formulas (6) and (7) may be present either alone or both in the same molecule of the modified silicone, for example.

In chemical formulas (6) and (7), R ¹ and R ² may each be, for example, a linear or branched alkylene group, an aralkylene group, an arylene group, or a phenylene group. R ¹ and R ² may be the same or different from each other. In addition, when multiple R ¹ are present in one molecule, they may be the same or different, and when multiple R ² are present in one molecule, they may be the same or different. The number of carbon atoms in the linear or branched alkylene group may be, for example, 1 or more, 2 or more, or 3 or more, or 18 or less, 10 or less, or 8 or less. Examples of the linear or branched alkylene group include methylene group, dimethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group and the like.

^{The viscosity} of the ^{amino -} modified ^silicone is not particularly limited. s or less, 50 mm ² /s or more, 100 mm ² /s or more, 150 mm ² /s or more, or 200 mm ² /s or more. The kinematic viscosity is a numerical value obtained by dividing the viscosity by the density. Also, 1 mm ² /s is equal to 1 cSt (centistokes). From the viewpoint of coating uniformity on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the viscosity is not too high. It is preferable that the viscosity is not too low from the viewpoint of supportability on the surface-hydrophilic non-swelling inorganic powder.

The amino functional group equivalent of the amino-modified silicone is not particularly limited, but may be, for example, 300 g/mol or more, 500 g/mol or more, or 600 g/mol or more, 30000 g/mol or less, 20000 g/mol or less, or It may be 10000 g/mol or less. From the viewpoint of coating uniformity on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the amino functional group equivalent is as high as possible. On the other hand, it is preferable that the amino functional group equivalent is not too high from the viewpoint of supportability on the surface-hydrophilic non-swelling inorganic powder. In addition, an amino functional group equivalent can be measured and calculated by the following method, for example.

(Method for measuring amino functional group equivalent)
About 1.0 g of the sample is accurately weighed in a clean beaker (capacity 100 ml), then about 60 ml of isopropyl alcohol is added and thoroughly stirred to dissolve the sample. Thereafter, titration is performed with an N/5 isopropyl alcoholic hydrochloric acid solution (reagent grade 1) using an automatic titrator, and the amine value of the sample is calculated by the following formula [1]. In addition, "amine value" is synonymous with amino functional group equivalent. Also, "N/5" means 1/5 normality (hydrochloric acid concentration), which is equal to the HCl concentration of 0.2 mol/L.

Amine value = (mL number of N/5HCl) x F x 11.22/(sample g number) [1]

In the formula [1], "N/5HCl" means the N/5 isopropyl alcoholic hydrochloric acid solution (first grade reagent). F is the titer of N/5HCl.

Specific examples of the amino-modified silicone include Shin-Etsu Silicone (registered trademark of Shin-Etsu Chemical Co., Ltd.) KF-8004, KF-869, KF-8005, KF-393 (all trade names), Momentive - TSF4704 (trade name) of Performance Materials, WACKER L655 (trade name) of Asahi Kasei Wacker Silicone Co., Ltd., and the like.

Although the epoxy-modified silicone is not particularly limited, for example, in the chemical formulas (1) to (5), the organic group may be a group represented by the following chemical formula (8).

In the chemical formula (8), R ³ may be, for example, a linear or branched alkylene group, an aralkylene group, an arylene group, or a phenylene group. Further, when a plurality of R ³ are present in one molecule, they may be the same or different, and the linear or branched alkylene group may have, for example, 1 or more, 2 or more, or 3 or more carbon atoms. but may be 18 or less, 10 or less, or 8 or less. Examples of the linear or branched alkylene group include methylene group, dimethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group and the like.

^{The viscosity} of the ^{epoxy -} modified ^silicone is not particularly limited. s or less, 20 mm ² /s or more, 25 mm ² /s or more, 50 mm ² /s or more, 100 mm ² /s or more, or 200 mm ² /s or more. From the viewpoint of coating uniformity on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the viscosity is not too high. It is preferable that the viscosity is not too low from the viewpoint of supportability on the surface-hydrophilic non-swelling inorganic powder.

The epoxy functional group equivalent of the epoxy-modified silicone is not particularly limited. There may be. From the viewpoint of coating uniformity on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the epoxy functional group equivalent is as high as possible. On the other hand, from the viewpoint of cost, it is preferable that the epoxy functional group equivalent weight is not too high. In addition, an epoxy functional group equivalent can be measured and calculated by the following method, for example.

(Method for measuring epoxy functional group equivalent)
1.0 g of sample is placed in a 100 ml beaker, and 15 ml of hydrochloric acid-dioxane solution is added with a whole pipette to dissolve. After standing for 5 minutes, 20 ml of ethanol and 5-6 drops of phenolphthalein are added. On the other hand, titration is performed with 0.1N (0.1 mol/L) NaOH. The end point of this titration is taken as colorless to pink. Separately, perform a blank titration in the same manner. Then, the epoxy value of the sample is calculated based on the following formula [2]. In addition, "epoxy value" is synonymous with epoxy functional group equivalent.

Epoxy value (g/mol) = 0.1 (BT) / 1000W [2]

The meanings of the symbols in the formulas are as follows.

B: NaOH titer (ml) required for blank
T: NaOH titer (ml) required for the sample
W: Sample collection amount (g)

Specific examples of the epoxy-modified silicone include X-22-343 and KF-1001 (both trade names) of Shin-Etsu Silicone (registered trademark of Shin-Etsu Chemical Co., Ltd.), or Momentive Performance Materials. and YF3965 (trade name) available from the same company.

The hydrogen-modified silicone (hydrogensilicone) may be, for example, a compound in which at least one of R in the chemical formula (1) is replaced with a hydrogen atom. , Q is a hydrogen atom.

^{The viscosity} of the hydrogen ^- modified ^silicone is not particularly limited. s or more, 10 mm ² /s or more, or 20 mm ² /s or more. From the viewpoint of coating uniformity on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the viscosity is not too high. It is preferable that the viscosity is not too low from the viewpoint of supportability on the surface-hydrophilic non-swelling inorganic powder.

The hydrogen functional group equivalent of the hydrogen-modified silicone is not particularly limited, but may be, for example, 20 g/mol or more, 30 g/mol or more, or 50 g/mol or more, and 200 g/mol or less and 180 g/mol or less. , or 160 g/mol or less. From the viewpoint of supportability on the surface-hydrophilic non-swelling inorganic powder, it is preferable that the hydrogen functional group equivalent is as high as possible. On the other hand, from the viewpoint of cost, it is preferable that the hydrogen functional group equivalent is not too high. The hydrogen functional group equivalent can be measured and calculated, for example, by the method of the amino functional group equivalent and the epoxy functional group equivalent.

Specific examples of the hydrogen-modified silicone include Shin-Etsu Silicone (registered trademark of Shin-Etsu Chemical Co., Ltd.) KF-99 and KF-9901 (both trade names).

The silane having a reactive group may be, for example, a compound in which at least one hydrogen atom of silane is substituted with a reactive group. In a narrow sense, silane may refer only to SiH ₄ , but in the present invention, it includes, for example, silicon hydrides in general, and is represented, for example, by the composition formula Si _n H _2n+2 . In the silane having a reactive group, the "reactive group" refers to a functional group capable of reacting with some other substance, for example, it may be a functional group capable of reacting with surface hydrophilic non-swelling inorganic powder. . Examples of the reactive group include, but are not limited to, fluoro, chloro, bromo, iodo, methoxy, vinyl, amino, and imino groups.

Specific examples of the silanes having reactive groups include alkoxysilanes, silazanes, chlorosilanes, etc. More specifically, for example, LS of Shin-Etsu Silicone (registered trademark of Shin-Etsu Chemical Co., Ltd.) -10, LS-190, LS-530 (all trade names), or company's.

The silane coupling agent is not particularly limited, and may be, for example, the same as or similar to a general silane coupling agent. Silane coupling agents contain, for example, in their molecules reactive groups for organic substances (functional groups capable of reacting with organic substances) and reactive groups for inorganic substances (functional groups capable of reacting with inorganic substances). , can combine organic and inorganic substances.

As the silane coupling agent, specifically, for example, Shin-Etsu Silicone (registered trademark of Shin-Etsu Chemical Co., Ltd.) KBM-303, KBM-602 (both trade names), or Momentive Performance Materials A-137, A-171 (both trade names) and the like.

The amount of the surface hydrophobizing agent (B) used in the production of the tire inner surface release agent of the present invention is not particularly limited. On the other hand, it may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, or 2.0% by mass or more, 10% by mass or less, 9 % by mass or less, 8% by mass or less, 7% by mass or less, or 6% by mass or less.

[1-1-1-3. Method for producing surface hydrophilic non-swelling inorganic powder (AB) hydrophobized by surface hydrophobizing agent]
Next, a method for producing the surface-hydrophilic non-swelling inorganic powder (AB) (component (AB)) hydrophobized by a surface-hydrophobizing agent will be described with an example. The method for producing the component (AB) is not particularly limited, but is, for example, as follows.

The component (AB) can be produced by hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder (A) (component (A)) with the surface hydrophobizing agent (B) (component (B)). can. In the production of the component (AB), the mass ratio of the surface hydrophilic non-swelling inorganic powder (A) (component (A)) and the surface hydrophobizing agent (B) (component (B)) is particularly limited. However, the component (B)/component (A) (mass ratio) may be, for example, 0.01 or more, 0.02 or more, or 0.03 or more, and may be 20 or less, 18 or less, 16 14 or less, or 12 or less. The range of component (B)/component (A) (mass ratio) may be, for example, 0.01-20.

The method for hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder (A) with the surface hydrophobizing agent (B) is not particularly limited. The surface hydrophobizing agent (B) may simply be stirred and mixed. As the device for stirring, for example, a Henschel mixer (trade name) can be used, but it is not limited to this and any device can be used. Instead of the Henschel mixer, the stirring device may be, for example, a Lödige mixer, a high speed mixer, a Nauta mixer, a Newgra machine, a Shugi mixer, a Proshare mixer, a Spartan mixer, a Pag mixer, or a turbulizer (any (trade name), a horizontal cylindrical mixer, a kneading extruder, a horizontal continuous kneader, a closed consolidation apparatus, and the like can also be used. The stirring speed is not particularly limited. good too. The stirring time is not particularly limited, but may be, for example, 5 minutes or more, 10 minutes or more, 15 minutes or more, 20 minutes or more, or 25 minutes or more, and 60 minutes or less, 55 minutes or less, or 50 minutes or less. , 45 minutes or less, or 40 minutes or less. Further, during the stirring, the mixture may be stirred only at room temperature without heating or the like, but heating or the like may be performed as necessary. The temperature during the stirring is not particularly limited. 55° C. or lower, or 50° C. or lower. Thus, the surface of the surface hydrophilic non-swelling inorganic powder (A) is hydrophobized by the surface hydrophobizing agent (B), and the surface hydrophilic non-swelling inorganic powder hydrophobized by the surface hydrophobizing agent. (AB) (Component (AB)) can be produced.

In the stirring and mixing, as described above, only the surface hydrophilic non-swelling inorganic powder (A) and the surface hydrophobizing agent (B) may be stirred and mixed. Alternatively, using another liquid or the like, the surface hydrophilic non-swelling inorganic powder (A) is dispersed in the liquid, and the surface hydrophobizing agent (B) is dispersed or dissolved, and stirred and mixed. may Examples of the liquid include water and an organic solvent, and one type may be used alone, or two or more types may be used in combination. The organic solvent is not particularly limited, but an organic solvent in which the surface hydrophobizing agent (B) has a high solubility is preferable. The organic solvent may be, for example, an alcohol. The alcohol may be a monohydric alcohol or a polyhydric alcohol. Examples of the alcohol include methanol, ethanol, normal propanol, isopropanol, ethylene glycol, propylene glycol and the like.

Further, the component (AB) may be obtained by hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder (A) with the surface hydrophobizing agent (B). The powder (A) and the surface hydrophobizing agent (B) may or may not react. Specifically, for example, a covalent bond may be formed between the surface-hydrophilic non-swelling inorganic powder (A) and the surface-hydrophobizing agent (B) through a reaction between them. In addition, for example, the surface hydrophilic non-swelling inorganic powder (A) and the surface hydrophobizing agent (B) do not react, and the surface hydrophilic non-swelling powder (A) and the surface hydrophobizing agent (B) do not react, and the electrostatic attraction, intermolecular force, etc. between the two causes the surface hydrophilic non-swelling The surface of the organic powder (A) may be coated with the surface hydrophobizing agent (B).

In the component (AB), the surface of the surface hydrophilic non-swelling inorganic powder (A) is hydrophobized by the surface hydrophobizing agent (B), for example, the component (AB) is dispersed in water. This can be confirmed by visually inspecting. Specifically, when the surface of the surface-hydrophilic non-swelling inorganic powder is not hydrophobized, the surface-hydrophilic non-swelling inorganic powder is easily dispersed in water (the degree of dispersion of the surface-hydrophilic non-swelling inorganic powder is high), which reduces the transparency of the water. On the other hand, when the surface of the surface-hydrophilic non-swelling inorganic powder is hydrophobized, the surface-hydrophilic non-swelling inorganic powder is difficult to disperse in water (the degree of dispersion of the surface-hydrophilic non-swelling inorganic powder is low). ), the transparency of water is less likely to decrease. For example, a surface-hydrophilic non-swelling inorganic powder is dispersed in water in a container, and the transparency of the water is judged by the visibility of the other side of the container. You can check the presence or absence. More specifically, for example, it can be confirmed whether or not the surface of mica is hydrophobized by the "mica surface hydrophobization evaluation method" described in Examples below. When the surface-hydrophilic non-swelling inorganic powder contains other than mica, or when it consists only of other than mica (i.e., does not contain mica), the same method as in the above-mentioned "method for evaluating surface hydrophobicity of mica" It can be confirmed whether the surface of the surface-hydrophilic non-swelling inorganic powder is hydrophobized.

Furthermore, for example, as described in the examples below, in the release agent for tire inner surface or the aqueous dispersion of the release agent for tire inner surface of the present invention, the occurrence of oil spots is suppressed or prevented. It can be confirmed that the surface of the surface hydrophilic non-swelling inorganic powder (A) is hydrophobized by the surface hydrophobizing agent (B).

[1-1-2. Surface hydrophilic non-swelling inorganic powder surface non-reactive silicone (C)]
The non-reactive silicone (C) (component (C)) with respect to the surface of the surface-hydrophilic non-swelling inorganic powder is, as described above, part of the release agent (release component) (R). The component (C) is not particularly limited, and examples thereof include organopolysiloxanes. The organopolysiloxanes are concepts including silicone oil, silicone rubber, and silicone resin. More specifically, the organopolysiloxanes include, for example, [1] alkylpolysiloxanes such as dimethylpolysiloxane, diethylpolysiloxane, methylisopropylpolysiloxane and methyldodecylpolysiloxane, [2] methylphenylpolysiloxane, Alkylphenylpolysiloxanes such as dimethylsiloxane/methylphenylpolysiloxane copolymers and dimethylsiloxane/diphenylsiloxane copolymers, [3] alkylaralkylpolysiloxanes such as methyl(phenylethyl)polysiloxane and methyl(phenylpropyl)polysiloxane , [4] 3,3,3-trifluoropropylmethylpolysiloxane and the like. Only one type of the silicone component may be used, or a plurality of types may be used in combination.

When part or all of the surface hydrophobizing agent (B) is non-reactive silicone with respect to the surface of the surface hydrophilic non-swelling inorganic powder, The content of reactive silicone is not included in the content of component (C), but included in the content of component (B). That is, in the release agent for tire inner surface of the present invention, even when part or all of the surface hydrophobizing agent (B) is non-reactive silicone with respect to the mica surface, the surface hydrophobizing agent (B) Separately from (other than the surface hydrophobizing agent (B)), the component (C) is included. In this case, in the surface hydrophobizing agent (B), the non-reactive silicone with respect to the surface of the surface hydrophilic non-swelling inorganic powder may be the same substance as the component (C), or may be a different substance.

The component (C) can further suppress the generation of oil spots, for example, by being supported on the components (AB) and (E). Also, the component (C) may be, for example, a silicone emulsion containing a silicone component and a surfactant. When the component (C) is the silicone emulsion, the content of the surfactant contained therein is not included in the content of the surfactant (D) (component (D)) described later, and the content of the component It shall be included in the content of (C). In the silicone emulsion, the silicone component preferably has a straight-chain molecular structure, a low degree of polymerization, and fluidity at room temperature, for example, from the viewpoint of releasability (mold releasability). The viscosity of the silicone component is not particularly limited, and is, for example, 1,000 to 100,000 mPa·s and 5,000 to 50,000 mPa·s at 25° C. from the viewpoint of the balance between releasability and product stability.

The surfactant contained in the silicone emulsion is not particularly limited, and may be a cationic surfactant, an anionic surfactant, or a nonionic surfactant, but at least one of an anionic surfactant and a nonionic surfactant is preferably included. The anionic surfactant is not particularly limited. Carboxylic acid type such as salt, [2] higher alcohol sulfate salt, polyoxyalkylene higher alcohol sulfate salt, alkylphenyl ether sulfate salt, polyoxyalkylene alkylphenyl ether sulfate salt, glycerin fatty acid ester monosulfate salt, etc. [3] Sulfonic acid type such as alkanesulfonate, α-olefin sulfonate, linear alkylbenzene sulfonate, α-sulfo fatty acid ester salt, dialkyl sulfosuccinate, [4] Alkyl phosphate Ester salts, polyoxyalkylene alkyl phosphate ester salts, polyoxyalkylene alkyl phenyl phosphate ester salts, phosphate ester types such as glycerin fatty acid ester monophosphate ester salts, and the like. The nonionic surfactant is also not particularly limited. and polyoxyalkylene alkylphenyl ether such as phenyl ether. Only one type of the surfactant may be used, or a plurality of types may be used in combination.

The silicone emulsion (silicone emulsion) may be produced, for example, by dispersing the silicone component in water using the surfactant and emulsifying it. Dispersion and emulsification methods are not particularly limited, and general dispersion and emulsification methods may be used. For example, first, at least one of a nonionic surfactant and an anionic surfactant is mixed with a silicone component. On the other hand, a specified amount of water is put into a container in which an emulsifier is installed in advance. Next, while stirring the water with the emulsifier, the mixed liquid of the silicone component and the surfactant is added little by little (for example, over 1 hour) and dispersed. Furthermore, the above-mentioned silicone emulsion (silicone emulsion) is produced by stirring until emulsified. The emulsifier is not particularly limited, and may be a general emulsifier such as Homomixer and Homodisper (both are trade names). As the silicone emulsion, for example, a commercially available silicone emulsion may be used as it is. Examples of commercially available silicone emulsions include KM-862T (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., FZ-4157 (trade name) manufactured by Dow Corning Toray Co., Ltd., and the like. Only one type of the silicone emulsion may be used, or a plurality of types may be used in combination.

Although not particularly limited, the residue mass after drying the silicone emulsion at 120° C. for 1 hour is, for example, 20 to 80% by mass relative to the total mass of the silicone emulsion before drying. , 30 to 70% by weight, or 30 to 65% by weight.

The content of the component (C) in the tire inner surface release agent of the present invention is not particularly limited, but for example, 3 % by mass or more, 4% by mass or more, or 5% by mass or more, 6% by mass or more, or 7% by mass or more, and 15% by mass or less, 14% by mass or less, 13% by mass or less, or 12% by mass or less , or 11% by mass or less.

[1-1-3. Other release ingredients]
The release agent (release component) (R) may or may not contain other release agents (release components) in addition to the components (AB) and (C). It doesn't have to be. The other release agent (release component) is not particularly limited. It may be a component obtained. Further, when the release agent (release component) (R) contains the other release agent (release component), the other release agent (release component) may be of one type or a plurality of types. .

[1-2. Surfactant]
In the tire inner surface release agent of the present invention, the surfactant functions, for example, as a component that imparts emulsion stability. In addition, the said surfactant is called surfactant (D) or component (D) below for convenience. Further, the "emulsion stability" refers to the stability of the emulsion when the aqueous dispersion of the releasing agent for tire inner surface of the present invention is an emulsion. The emulsion is preferably an emulsion in which each component of the release agent for tire inner surface of the present invention is dispersed in water. Such an emulsion is an oil-in-water type emulsion (emulsion).

In the component (D), the surfactant is not particularly limited, and may be a cationic surfactant, a nonionic surfactant, or an anionic surfactant. At least one of a nonionic surfactant and an anionic surfactant is preferred. Examples of the nonionic surfactants include [1] polyoxyalkylene alkyl ethers such as polyoxyethylene cetyl ether and polyoxyethylene lauryl ether; [2] polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether; Polyoxyalkylene alkylphenyl ether, [3] Polyoxyalkylene fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monooleate, [4] Polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, etc. polyoxyalkylene sorbitan fatty acid ester, [5] polyoxyalkylene hydrogenated castor oil, [6] polyoxyalkylene sorbitol fatty acid ester, [7] polyglycerin fatty acid ester, [8] alkyl glycerin ether, [9] polyoxyalkylene cholesteryl ether , [10] alkyl polyglucoside, [11] sucrose fatty acid ester, [12] polyoxyalkylene alkylamine, [13] oxyethylene-oxypropylene block polymer, and the like. Examples of the anionic surfactant include [1] fatty acid salts such as sodium oleate, potassium palmitate, and triethanolamine oleate; [2] sodium lauryl sulfate, ammonium lauryl sulfate, sodium stearyl sulfate, sodium cetyl sulfate, and the like; Alkyl sulfates, [3] Polyoxyalkylene alkyl ether acetates such as sodium polyoxyethylene tridecyl ether acetate, [4] Alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, [5] Polyoxyalkylene alkyl ether sulfates salts, [6] higher fatty acid amide sulfonates such as Na stearoylmethyltaurate, Na lauroylmethyltaurate, Na myristoylmethyltaurate, Na palmitoylmethyltaurate, [7] N-acylsarcosine salts such as sodium lauroylsarcosinate, [8] Alkyl phosphates such as sodium monostearyl phosphate, [9] Polyoxyalkylene alkyl ether phosphate salts such as sodium polyoxyethylene oleyl ether phosphate and sodium polyoxyethylene stearyl ether phosphate, [10] Di-2 -long-chain sulfosuccinates such as sodium ethylhexyl sulfosuccinate and sodium dioctyl sulfosuccinate, [11] long-chain N-acylglutamates such as monosodium N-lauroyl glutamate and disodium N-stearoyl-L-glutamate, and the like. be done. Component (D) may contain only one surfactant, or two or more surfactants may be used in combination.

The content of the component (D) in the tire inner surface release agent of the present invention can be selected according to the purpose. It may be from 1 to 17 wt%, from 1 to 15 wt%, or from 2 to 13 wt%. From the viewpoint of the emulsification stability of the release agent for tire inner surface, and from the viewpoint of preventing the phenomenon of repelling due to a decrease in wettability to the raw tire or bladder, the content of the component (D) is 1% by mass. The above is preferable. In addition, from the viewpoint of adhesion and release properties of the release agent for the inner surface of the tire, and from the viewpoint of preventing the phenomenon that the release agent enters the bonded portion of the tire and causes adhesion inhibition, the component (D) is included. The ratio is preferably 17% by mass or less.

Part or all of the component (D) may be mixed with the component (C) (silicone non-reactive to the surface of the surface hydrophilic non-swelling inorganic powder) in the preliminary mixing step. . The pre-mixing step may or may not be performed. The pre-mixing step is preferable because the component (C) is easily mixed with other components in the subsequent mixing step. In the following description, of the component (D), the component used in the preliminary mixing step may be referred to as "component (D1)".

As described above, when the pre-mixing step is performed, the component (C) is easily mixed uniformly with the inorganic powder (inorganic powder), which is another component of the release agent for the tire inner surface, in the subsequent mixing step. It is preferable because Although the reason is not necessarily clear, by mixing the component (C) and the component (D1), a silicone emulsion is formed by the mixture of the component (C) and the component (D1), and the component This is probably because (C) becomes easier to uniformly adhere to the surface of the inorganic powder. The component (D1) may be all of the component (D), but is preferably a part of the component (D). A silicone emulsion made of a mixture of the component (C) and the component (D1) tends to have high stability (emulsion stability) when the amount of the component (D1) is large. is too high, the component (C) is rather difficult to adhere to the surface of the inorganic powder. When the stability (emulsion stability) of the silicone emulsion is moderately low due to a small amount of the component (D1), the emulsification is likely to be destroyed, and the component (C) tends to adhere to the surface of the inorganic powder. Conceivable. It is believed that this makes it easier for the component (C) (silicone) to be carried on the surface of the inorganic powder, making it difficult to redisperse. Then, the component (D) other than the component (D1) makes it easier for the inorganic powder to which the component (C) adheres to disperse in the tire inner surface release agent or the aqueous dispersion of the tire inner surface release agent. Conceivable. Examples of the inorganic powder include the component (AB) and the surface-hydrophobic inorganic powder (E) described below.

The amount of the component (D1) is not particularly limited. 1.0% by mass or more, or 1.5% by mass or more, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, It may be 1.5% by mass or less, or 1.0% by mass or less. Further, the surfactant (D1) is not particularly limited, but an anionic surfactant is preferable. The anionic surfactant is, for example, [1] carboxylic acids such as higher fatty acid salts, alkyl ether carboxylates, polyoxyalkylene ether carboxylates, alkyl (or alkenyl) amide ether carboxylates, acylamino carboxylates, etc. [2] Sulfuric acid ester types such as higher alcohol sulfates, polyoxyalkylene higher alcohol sulfates, alkylphenyl ether sulfates, polyoxyalkylene alkylphenyl ether sulfates, and glycerin fatty acid ester monosulfate salts, [3] Alkanesulfonates, α-olefinsulfonates, linear alkylbenzenesulfonates, α-sulfofatty acid ester salts, sulfonic acid types such as dialkylsulfosuccinates, [4] Alkyl phosphate salts, polyoxy Phosphate esters such as alkylene alkyl phosphates, polyoxyalkylene alkylphenyl phosphates, glycerin fatty acid ester monophosphates, and the like, among which higher alcohol sulfates and alkylphenyl ether sulfates , alkanesulfonates, α-olefinsulfonates, linear alkylbenzenesulfonates, and α-sulfofatty acid ester salts are preferred.

[1-3. Surface Hydrophobic Inorganic Powder]
As described above, the tire inner surface release agent of the present invention may further contain a surface-hydrophobic inorganic powder. In the tire inner surface mold release agent of the present invention, the surface hydrophobic inorganic powder is an optional component and may or may not be contained. ) etc., it is preferable to include. Hereinafter, the surface-hydrophobic inorganic powder is referred to as surface-hydrophobic inorganic powder (E) or component (E) for convenience. The surface-hydrophobic inorganic powder (E) (component (E)) is not particularly limited, and may be, for example, a surface-hydrophobic inorganic powder that is commonly used as a release agent for the inner surface of a tire. Examples of the component (E) include talc and the like, and these may be natural products or synthetic products. In addition, talc or the like is considered to work as, for example, a lubricant in the release agent for tire inner surface. In addition, talc or the like, for example, is thought to work as a lubricant and also work to enhance the releasability of the tire inner surface release agent. It can be said that the lubricant having such a function is also part of the mold release agent (mold release component).

The content of the component (E) in the tire inner surface release agent of the present invention can be selected according to the purpose. It may be from 20 to 70% by weight, or from 25 to 65% by weight.

In the tire inner surface release agent of the present invention, the ratio (Aw/Ew) of the mass (content ratio Aw) of the component (A) to the mass (content ratio Ew) of the component (E) is not particularly limited. for example, 0.1 to 5, 0.1 to 3, or 0.2 to 1.1.

In the present invention, whether the surface of the inorganic powder is hydrophilic or hydrophobic can be confirmed, for example, by the same method as the "mica surface hydrophobization evaluation method" described in Examples below.

[1-4. Other optional ingredients, etc.]
As described above, the tire inner surface release agent of the present invention contains the surface hydrophobic inorganic powder (E) as an optional component in addition to the release agent (R) and the surfactant (D). may or may not be included. In addition, the release agent for tire inner surface of the present invention may or may not contain optional components other than the surface-hydrophobic inorganic powder (E). Examples of other optional components include thickeners, water retention agents, polyhydric alcohols that can contribute to improving transparency, water, various antifoaming agents such as silicone antifoaming agents and mineral oil antifoaming agents, and various antifoaming agents. Preservatives and the like are included.

Examples of the thickener include water-swellable inorganic powders. Examples of the water-swellable inorganic powder include, but are not limited to, water-swellable clay minerals, montmorillonite, beidellite, nontronite, saponite, hectorite, stevensite, and bentonite containing montmorillonite.

The water-retaining agent is not particularly limited, and may be, for example, the same water-retaining agent used as a general release agent for the inner surface of a tire. More specific examples include polyhydric alcohols, alginic acid, sodium polyacrylate, and the like, which will be described later.

The polyhydric alcohol is not particularly limited. , tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol and other polypropylene glycols, [3] dibutylene glycol, tributylene glycol, tetrabutylene glycol, pentabutylene glycol, hexabutylene glycol and other polybutylene glycols, [4] Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,6-hexane Diol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonane Diol, 1,2-nonanediol, 1,10-decanediol, 1,2-decanediol, 1,12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol , 1,16-hexadecanediol, 1,2-hexadecanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 3- Methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-dimethylpentanediol, 2,2-diethyl-1,3-propanediol , 2,2,4-trimethyl-1,3-pentanediol, dimethyloloctane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1, 8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4 -cyclohexanedimethanol, 1,2-cycloheptanediol, tricyclodecanedimethanol, glycerin, trimethylolpropane, 1,2,6-hexanetriol, 3 -methylpentane-1,3,5-triol, hydroxymethylhexanediol, trimethyloloctane, and copolymers of two or more of these. One type of these polyhydric alcohols may be used, or a plurality of types may be used in combination.

The bulk density of the tire inner surface release agent of the present invention is not particularly limited, but may be, for example, 0.70 to 1.5 g/cm ³ . When the tire inner surface release agent of the present invention has a bulk density within the above range, for example, sedimentation suppression over time and uniform application by spraying are further improved. Said bulk density may be, for example, between 0.75 and 1.45 g/cm ³ , or between 0.80 and 1.40 g/cm ³ . The bulk density can be measured, for example, by the following method.

(Method for measuring bulk density)
A release agent for tire inner surface is placed in a bag so that the volume is 40% by volume or less. Next, air is taken into the bag and shaken about 20 times. Then, the contents of the bag are put into a 120 mL cup that has been weighed in advance while shaking the bag using a spatula. The cup contents are then weighed after the top of the cup has been scraped off. The mass per 100 mL of the contents of the cup at this time is calculated and taken as the bulk density.

[2. Manufacturing method of release agent for tire inner surface]
The method for producing the release agent for tire inner surface of the present invention is not particularly limited, but for example, it can be produced by the above-described method for producing the release agent for tire inner surface of the present invention. Specifically, the tire inner surface release agent of the present invention can be produced (prepared) as follows, for example.

First, the hydrophobizing step of hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder (A) with the surface hydrophobizing agent (B) is carried out. For this hydrophobization step, for example, the above [1-1-1-3. Production method of surface hydrophilic non-swelling inorganic powder (AB) hydrophobized by surface hydrophobizing agent].

Next, prior to the mixing step of mixing the components (R), (D) and (E), the component (C) (silicone non-reactive to the surface of the surface hydrophilic non-swelling inorganic powder) and , the pre-mixing step of mixing with at least part of the component (D) (surfactant) may or may not be performed. As described above, the preliminary mixing step is preferable because the component (C) is easily mixed with other components in the subsequent mixing step. Moreover, as described above, the component (D1) may be a part of the component (D) or may be the whole component, but is preferably a part of the component (D).

The pre-mixing step is not particularly limited, and for example, the components (C) and (D1) may simply be mixed. The mass ratio between the component (C) and the component (D1) is not particularly limited, but may be, for example, 5 or more, 7 or more, or 10 or more. The component (C)/component (D1) (mass ratio) is, for example, 100 or less, 90 or less, 80 or less, 70 or less, 60 or less, 50 or less, 40 or less, 30 or less, or 20 or less. good too. The method of mixing the components (C) and (D1) is also not particularly limited, but for example, they may be mixed by stirring with a stirring device. The device for stirring is not particularly limited, but may be, for example, a general emulsifying machine such as Homomixer, Homodisper (both trade names), and the like. The stirring speed is not particularly limited. good too. The stirring time is not particularly limited, but may be, for example, 0.5 minutes or longer, 1 minute or longer, 2 minutes or longer, 3 minutes or longer, or 4 minutes or longer. minutes or less, or 15 minutes or less. Further, during the stirring, the mixture may be stirred only at room temperature without heating or the like, but heating or the like may be performed as necessary. The temperature during the stirring is not particularly limited. 45° C. or lower, or 40° C. or lower. Thus, the pre-mixing step of mixing the components (C) and (D1) can be performed.

Next, the mixing step of mixing the components (R), (D) and (E) is performed. The component (R) is, as described above, a mold release agent (mold release component) and includes the components (AB) and (C). The components (AB) and (C) may be mixed in advance prior to the mixing step, or the components (AB) and (C) may be mixed in the mixing step. Further, the component (C) may be mixed in advance with the component (D1) in the preliminary mixing step, as described above.

The mixing step is not particularly limited, and for example, the components (R), (D) and (E) may simply be mixed. Further, for example, optional components may be further mixed. For the optional component, for example, the above [1-4. Optional components, etc.].

In the mixing step, the method of mixing each component is not particularly limited as described above, but for example, it may be carried out as follows. That is, first, the component (AB) and the component (E), which are powder components, and other optional powder components as necessary are placed in a stirring device and stirred at 100 to 4000 rpm (e.g., 1000 rpm). Stir for 3-50 minutes (eg, 5 minutes). As the device for stirring, for example, a Henschel mixer (trade name) can be used, but it is not limited to this and any device can be used. Instead of the Henschel mixer, the stirring device may be, for example, a Lödige mixer, a high speed mixer, a Nauta mixer, a Newgra machine, a Shugi mixer, a Proshare mixer, a Spartan mixer, a Pag mixer, or a turbulizer (any (trade name), a horizontal cylindrical mixer, a kneading extruder, a horizontal continuous kneader, a closed consolidation apparatus, and the like can also be used. Next, the component (C) and the component (D), which are liquid components, and, if necessary, any other liquid component, are sequentially added to the stirring device while stirring, and then 100 Stir at ~4000 rpm (eg 1000 rpm) for 10-30 minutes. In this manner, the mixing step is carried out to manufacture (preparate) the tire inner surface release agent of the present invention. The agitation Froude number in the agitation after all ingredients are added may be, for example, 0.5-25, or 0.9-20. When the agitation Froude number is 0.5 or more, deterioration of aqueous dispersion stability and sprayability can be suppressed. Further, when the agitation fluid number is set to 25 or less, the high cost of equipment can be suppressed. The stirring Froude number (Fr) is defined, for example, by the following formula (I). The product P of the stirring Froude number and the stirring time (unit: minutes) (that is, P=stirring Froude number×stirring time (minutes)) may be, for example, 5 to 200, or 10 to 150.

Fr=V/[(R×g) ^0.5 ] (I)
V: Peripheral speed of tip of stirring blade (m/s)
R: radius of rotation of stirring blade (m)
g: gravitational acceleration (m/s ² )

The average particle size of the tire inner surface release agent produced according to the present invention is not particularly limited, but may be, for example, 0.1 to 10 mm, or 0.2 to 8 mm. When the average particle size is 0.1 mm or more, deterioration of aqueous dispersion stability and sprayability can be suppressed. Further, when the average particle size is 10 mm or less, deterioration of solubility can be suppressed. The average particle size is, for example, a 50% size in a mass-based integrated fraction measured using a sieve method. Specifically, the average particle diameter is, for example, 6 stages of sieves with openings of 16000 μm (16 mm), 9500 μm (9.5 mm), 5000 μm (5.0 mm), 1000 μm, 500 μm and 100 μm (0.10 mm) , is measured by a classification operation using a saucer. In the classification operation, the tray is stacked in order from sieves with small mesh openings to sieves with large mesh openings, 100 g / time of sample (releasing agent for tire inner surface) is put from the top of the uppermost sieve, and the lid is closed. attached to a low tap type sieve shaker (manufactured by Iida Seisakusho Co., Ltd., tapping: 156 times / minute, rolling: 290 times / minute) and vibrated for 10 minutes. sample) is collected for each sieve mesh. The mass of the classified sample of each particle size is measured, and the mass frequency (%) is calculated. When obtaining the average particle size, the first sieve opening at which the cumulative mass frequency is 50% or more is "a (μm)", and the sieve opening one step larger than a (μm) is "b ( μm)”, the integrated value of the mass frequency from the tray to the sieve with opening a (μm) is “c (%)”, and the mass frequency on the sieve with opening a (μm) is “d (%) ”, and the average particle size (50% by mass particle size) determined by the following formula (II) is defined as the average particle size.

Average particle size (50 mass% particle size)
=10 ^{[50-{cd/(logb-loga)*logb}]/{d/(logb-loga)}} (II)

In the tire inner surface release agent produced according to the present invention, the proportion of particles that do not pass through a 9.5 mm sieve is preferably less than 50% by mass, more preferably less than 30% by mass. In the produced release agent for tire inner surface, the proportion of particles passing through a sieve with an opening of 0.10 mm is preferably less than 50% by mass, more preferably less than 30% by mass.

The order of addition of the component (C), the component (D) and the other optional liquid components is not particularly limited. For example, the agitation includes Henschel mixer, Redige mixer, high speed mixer, Nauta mixer, Nugra machine, Shugi mixer, Proshare mixer, Spartan mixer, Pag mixer, Turbulizer (all trade names), horizontal cylinder A release agent for the inner surface of a tire having a high bulk density can be obtained by using a high-speed rotatable agitating device such as a die mixer, a kneading extruder, a horizontal continuous kneader, or a closed compaction processing device.

The form of the tire inner surface release agent of the present invention is not particularly limited. For example, it may be in the form of powder or the like. It may be a substance (aqueous dispersion). The form of the aqueous dispersion of the tire inner surface releasing agent of the present invention is also not particularly limited. Preferably.

The method for producing (preparing) the aqueous dispersion of the tire inner surface release agent of the present invention is also not particularly limited, and for example, the tire inner surface release agent of the present invention may be simply mixed with water and dispersed. In the tire inner surface release agent aqueous dispersion of the present invention, the concentration of the tire inner surface release agent of the present invention is not particularly limited, and is, for example, 20 to 75% by mass, 30 to 70% by mass, or 30 to 75% by mass. It may be 65% by mass.

The method of using the release agent for tire inner surface of the present invention is also not particularly limited, and may be, for example, the same as for general release agents for tire inner surface. Specifically, for example, the release agent for tire inner surface of the present invention is sprayed in a state of undiluted solution or diluted with water to at least the inner surface of the unvulcanized rubber raw tire and the outer surface of the bladder. What is necessary is just to apply|coat to one side and to use it.

As described above, the tire inner surface release agent of the present invention may be an emulsion (emulsion, aqueous dispersion). The average particle size of the emulsion is not particularly limited, and may be, for example, 50 to 2000 nm, 100 to 1500 nm, or 150 to 1300 nm. From the viewpoint of preventing deterioration in adhesion and release properties due to an increase in the required compounding amount of the surfactant, and from the viewpoint of preventing adhesion inhibition when the release agent enters the bonding part, the average of the emulsion The particle diameter is preferably 50 nm or more. In addition, from the viewpoint of preventing creaming and coalescence of emulsion particles, and from the viewpoint of preventing poor product stability due to separation of water-soluble and oil-soluble components, the average particle size of the emulsion is 2000 nm or less. is preferred. In the present invention, the average particle size of the emulsified product is measured by measuring the volume distribution of the emulsified particles using, for example, a submicron particle analyzer (laser diffraction/scattering method) manufactured by BECKMAN. The average particle size can be calculated based on the volume distribution. However, this measuring method is an example, and the present invention is not limited by this measuring method.

[3. Tire manufacturing method and tire]
The tire manufacturing method and tire of the present invention are as described above. These are also not particularly limited. Except for using the dispersion liquid or the release agent for the inner surface of the tire, the manufacturing method of a general tire and the tire may be the same. In the tire manufacturing method of the present invention, examples of the mold include a mold. In the tire manufacturing method of the present invention, in addition to the release pretreatment step and the vulcanization step described above, release is performed between the vulcanized tire and the bladder and between the vulcanized tire and the mold. You may have a mold release treatment process to process.

Next, examples of the present invention will be described. However, the present invention is not limited to the following examples.

Using the raw materials shown in Table 2 below, release agents for the inner surface of tires of Examples 1 to 16 and Comparative Examples 1 and 2, which will be described later, were produced, and their performance was evaluated. In Table 2 below, "hydrogensilicone" in B-3-1 and B-3-2 is hydrogen-activated silicone. "Silane" of B-4-1, B-4-2 and B-4-3 is a silane having a reactive group. "Product name" is the product name (trade name) of the raw material. The “manufacturer” is the name of the company that sells the raw material. However, "Momentive" is Momentive Performance Materials, Inc., and "Shin-Etsu Silicone" is a registered trademark of Shin-Etsu Chemical Co., Ltd., the distributor. Moreover, "bulk specific gravity" is synonymous with "bulk density".

[Examples 1 to 17]
The release agents for tire inner surface of Examples 1 to 17 were produced as follows.

First, the surface of the component (A) (component (A), mica, surface hydrophilic non-swelling inorganic powder) described in Table 3 below was coated with the component (B) described in Table 3 below (component (B), the surface hydrophobizing agent) (hydrophobizing step). Specifically, first, the component (A), which is a powder component, was placed in a Henschel mixer (trade name) and stirred at 1000 rpm. Next, the component (B) was added while stirring at 1000 rpm, and the mixture was further stirred for 5 minutes to make the surface of the component (A) (mica) hydrophobic. Thus, component (AB), i.e. mica hydrophobized by a surface hydrophobizing agent, was produced.

It was confirmed that the surface of the mica (component (AB)) whose surface had been hydrophobized by the hydrophobization step was hydrophobized by the following evaluation method for surface hydrophobization of mica.

(Method for evaluating surface hydrophobicity of mica)
5 g of mica (component (AB)) whose surface was hydrophobized by the hydrophobizing step was dispersed in 100 g of water in a 200 mL glass bottle (inner diameter: 4 cm). A 1 mm wide by 2 cm long crosshair mark was then placed 1 cm away from one side of the vial. When the crosshairs were clearly visible from the opposite side of the glass bottle, it was evaluated as ◯, and when it was not visible, it was evaluated as x. Those with ◯ were evaluated as having a hydrophobized mica surface.

Next, the component (C) described in Table 3 below (component (C), a non-reactive silicone with respect to the mica surface) and the component (D1) described in Table 3 below (part of component (D) , surfactant) were mixed by stirring at 5000 rpm for 10 minutes with a homomixer (trade name) (pre-mixing step). Thus, a silicone emulsion (silicone emulsion), which is a mixture of the component (C) and the component (D1), was obtained. The life (stability) of this silicone emulsion was evaluated by the following method.

(Silicone emulsion life evaluation method)
The state of the silicone emulsion (silicone emulsion) produced in the preliminary mixing step was observed after standing for 5 minutes. ◯ indicates that the layer was separated into two layers after 5 minutes, and x indicates that the layer was uniform. Those evaluated as ◯ were evaluated as silicone emulsions with desired performance.

Furthermore, a mixing step of mixing the release agent (R) (the component (AB) and the component (C)), the component (D) and the component (E) was performed as follows, and Examples 1 to 16 were performed. A release agent for the inner surface of a tire was produced. That is, first, among the raw materials of the release agent for the tire inner surface, the powder component was placed in a Henschel mixer (trade name) and mixed by stirring at 1000 rpm for 5 minutes. In this example, the powder components are mica (component (AB)) whose surface has been hydrophobized by the hydrophobization step, and component (E) described in Table 3 below (component (E), surface hydrophobic inorganic powder ) and two. Further, after that, while continuing stirring at 1000 rpm with the Henschel mixer, the liquid component mixed in the pre-mixing step and other liquid components were added to the powder. In this example, the "other liquid component" is the component (D) (remainder of component (D), surfactant) and other components (water retention agent and thickener) shown in Table 3 below. . After that, they were further mixed by stirring at 1000 rpm for 10 minutes with the Henschel mixer. As described above, the mixing step was carried out to produce the tire inner surface release agents of Examples 1 to 16.

[Comparative Example 1]
The release agent for tire inner surface of Comparative Example 1 was prepared in the same manner as in Examples 1 to 16 except that the component (B) (component (B), surface hydrophobizing agent) was not used and the hydrophobizing step was not performed. manufactured. That is, in Comparative Example 1, instead of the mica hydrophobized by a surface hydrophobizing agent (component (AB)), mica whose surface was not hydrophobized (component (A)) was used. -16. In addition, when the mica (component (A)) whose surface was not hydrophobized used in Comparative Example 1 was evaluated by the above-described mica surface hydrophobization evaluation method, the evaluation result was × (the surface was not hydrophobized )Met.

The raw material code of each component in Table 3 below is the same as the raw material code in Table 2 above. The numbers are mass ratios (parts by mass) of each component. The total (% by mass) is the sum of components (A) to (E) and other components (water retention agent and thickener) and is 100% by mass. The (B)/(A) ratio (mass ratio) is a numerical value obtained by dividing the mass of component (B) (component (B), surface hydrophobizing agent) by the mass of component (A) (component (A), mica). is expressed as a percentage (%). The evaluation method and evaluation criteria for oil spots and releasability will be described later.

[Performance evaluation of release agent for tire inner surface]
Using the tire inner surface release agents of Examples 1 to 17 and Comparative Example 1, tire inner surface release agent aqueous dispersions were produced in the following manner, and performance was evaluated. Table 3 shows the evaluation results of oil spots and releasability.

(Method for producing aqueous dispersion of release agent for inner surface of tire)
After charging 450 g of tap water in a 2 L glass beaker, the mixture was stirred at a speed of 20 rpm with a stirrer equipped with three propeller blades with a diameter of 5 cm. Into the water, while stirring, 550 g of the powdery tire inner surface release agent produced in any one of Examples 1 to 16 and Comparative Example 1 was added, and stirred for 30 minutes to disperse. An aqueous release agent dispersion was prepared.

(Oil spot evaluation method)
Using a spray gun with a nozzle diameter of φ1.0 mm, each of the tire inner surface releasing agent aqueous dispersions was continuously sprayed onto the surface of the unvulcanized inner liner rubber sheet at an air pressure of 0.5 MPa for 10 seconds. After drying, an area of 4 cm×7 cm on the spray-coated surface was visually observed and judged. Specifically, the presence or absence of oil spots (oil droplets) was evaluated according to the following criteria. Evaluation results of Grade 3 or higher (from Grade 3 to Grade 5) were determined to be acceptable.

Oil spot judgment criteria:
Grade 5: 5 or less oil spots of less than 1 mm (no oil spots of 1 mm or more).
Grade 4: 6 or more and 10 or less oil spots of less than 1 mm (no oil spots of 1 mm or more).
Grade 3: 5 or less oil spots of 1 mm or more, or 11 to 20 oil spots of 1 mm or more.
Grade 2: 20 or less oil spots of 1 mm or more, or 21 or more oil spots of 1 mm or more.
Grade 1: 21 or more oil spots of 1 mm or more.

(Oil spot evaluation method (after 7 days))
Each of the tire inner surface release agent aqueous dispersions was stored at 25° C. for 7 days. Thereafter, each of the tire inner surface release agent aqueous dispersions was stirred for 2 minutes at a speed of 20 rpm with a stirrer equipped with three propeller blades with a diameter of 5 cm. Immediately after stirring, the presence or absence of oil spots was evaluated by the same method and criteria as in the "oil spot evaluation method". Evaluation results of Grade 3 or higher (from Grade 3 to Grade 5) were determined to be acceptable.

(Releasability evaluation method)
Each of the tire inner surface release agent aqueous dispersions was spray-coated on an unvulcanized inner liner rubber sheet of 4 cm×7 cm×0.2 cm so that the coating amount after drying was 10 g/m ² . Next, this unvulcanized rubber sheet was overlaid with a bladder rubber sheet of the same size, set in a tabletop test press, and vulcanized by pressing for 20 minutes at a mold temperature of 180° C. and a pressure of 20 kg/cm ² . . After that, the vulcanized rubber sheet was peeled off. The releasability (mold releasability) at the time of peeling was evaluated according to the following criteria. Evaluation results of Grade 3 or higher (from Grade 3 to Grade 5) were determined to be acceptable.

Releasability Criteria:
Grade 5: Easy peeling (releasing) without adhesion Grade 4: Peeling (releasing) Grade 3: Peeling force was large but releasing was possible Grade 2: Partially adhered and peeled (releasing) ) was difficult to remove Grade 1: Those that adhered to the entire surface and could not be peeled off (released)

As shown in Table 3 above, the tire inner surface release agents of Examples 1 to 17 all passed the oil spot evaluation results of grades 3 to 5, and the release property evaluation results were all good. Met. On the other hand, the release agent for tire inner surface of Comparative Example 1, in which the mica surface was not hydrophobized, had good release performance evaluation results, but the oil spot evaluation results were all poor at grade 1. .

In addition, for the tire inner surface release agent aqueous dispersions produced from the tire inner surface release agents of Examples 1 to 17 and Comparative Example 1, the oil spot immediately after production (adjustment) and after storage for 7 days, respectively. Evaluation and the mold releasability evaluation were performed. However, the evaluation results, as shown in Table 3, did not change immediately after production (adjustment) and after storage for 7 days. This shows that the release agents for tire inner surface of Examples 1 to 16 could suppress or prevent the occurrence of oil spots even after the aqueous dispersion of the release agent for tire inner surface was stored for a long time. show.

Claims (9)

A tire inner surface release agent comprising a release agent and a surfactant,
The release agent contains mica, which is a surface-hydrophilic non-swelling inorganic powder, and silicone, which is non-reactive with respect to the surface of the surface-hydrophilic non-swelling inorganic powder,
the surface of the surface-hydrophilic non-swelling inorganic powder is hydrophobized with a modified silicone that is a surface hydrophobizing agent, and the modified silicone is at least one of amino-modified silicone and epoxy-modified silicone;
The amino-modified silicone has a kinematic viscosity at 25° C. of 50 mm ² /s or more and 50000 mm ² /s or less, and an amino functional group equivalent weight of 300 g/mol or more and 30000 g/mol or less;
The epoxy-modified silicone has a kinematic viscosity at 25° C. of 20 mm ² /s or more and 50000 mm ² /s or less, and an epoxy functional group equivalent of 200 g/mol or more and 4000 g/mol or less,
The amount of mica used is 10% by mass or more and 60% by mass or less with respect to the total mass of all components other than water in the tire inner surface release agent,
The amount of the modified silicone used is 0.1% by mass or more and 10% by mass or less with respect to the total mass of all components other than water in the tire inner surface release agent.
A release agent for the inner surface of a tire characterized by: The release agent for tire inner surface according to claim 1, further comprising a lubricant. The mold release agent for tire inner surface according to claim 1 or 2, wherein the modified silicone is an amino-modified silicone. Furthermore, it contains a surface-hydrophobic inorganic powder,
4. The release agent for tire inner surface according to any one of claims 1 to 3, wherein a non-reactive silicone with respect to the surface of said surface-hydrophilic non-swelling inorganic powder adheres to said surface-hydrophobic inorganic powder. . An aqueous dispersion of a release agent for tire inner surface, comprising the release agent for tire inner surface according to any one of claims 1 to 4 and water. a hydrophobizing step of hydrophobizing the surface of the surface hydrophilic non-swelling inorganic powder with the surface hydrophobizing agent;
a mixing step of mixing the release agent, the surfactant, and the surface-hydrophobic inorganic powder;
The method for producing a tire inner surface release agent according to claim 4, comprising: 7. The method according to claim 6, further comprising a pre-mixing step of mixing non-reactive silicone with respect to the surface of said surface-hydrophilic non-swelling inorganic powder and at least part of said surfactant prior to said mixing step. Production method. Adhering the tire inner surface release agent aqueous dispersion according to claim 5 to the inner surface of the unvulcanized rubber raw tire,
Furthermore, a release pretreatment step for volatilizing water,
After the release pretreatment step, the bladder housed in the green tire is expanded in the mold to press the outer surface of the raw tire against the inner surface of the mold, and heat the green tire in that state. a vulcanization step of vulcanizing;
A method of manufacturing a tire, comprising: A tire comprising the release agent for tire inner surface according to any one of claims 1 to 4 adhered to the inner surface of the tire.