阅读说明：本技术 室温固化性有机聚硅氧烷组合物和结构体以及该组合物的固化状态的判别方法 (Room temperature-curable organopolysiloxane composition, structure, and method for determining cured state of the composition ) 是由 打它晃 坂本隆文 于 2018-12-27 设计创作，主要内容包括：本发明提供能够根据颜色的变化来视认固化程度的室温固化性有机聚硅氧烷组合物、其结构体和固化状态的判别方法。从未固化状态随着固化的进行而变色的、含有下述成分的室温固化性有机聚硅氧烷组合物。(A)由下述式(1)和/或(2)表示的有机聚硅氧烷：100质量份(式中,R为碳原子数1～10的未取代或卤素原子取代的一价烃基,n为10以上的整数)(式中,R和n如上所述,X为氧原子或碳原子数2～5的亚烷基,m独立地为0或1)；(B)(A)、(C)、(D)成分以外的、在一分子中具有至少3个硅原子结合水解性基团的有机硅化合物和/或其部分水解缩合物：0.1～50质量份；(C)固化催化剂：0.01～20质量份；(D)硅烷偶联剂：0.1～10质量份；(E)pH指示剂：0.01～10质量份。HO(SiR<Sub>2</Sub>O)<Sub>n</Sub>H (1)<Image he="94" wi="700" file="DDA0002643442380000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention provides a room temperature curing organopolysiloxane composition capable of visually confirming the curing degree according to the change of color, a structure thereof and a method for judging the curing state. A room temperature-curable organopolysiloxane composition which changes color from an uncured state as curing progresses and contains the following components. (A) An organopolysiloxane represented by the following formula (1) and/or (2): 100 parts by mass (wherein R represents the number of carbon atoms)1 to 10 monovalent hydrocarbon groups substituted with an unsubstituted or halogen atom, n is an integer of 10 or more) (wherein R and n are as defined above, X is an oxygen atom or an alkylene group having 2 to 5 carbon atoms, and m is independently 0 or 1); (B) an organosilicon compound having a hydrolyzable group bonded to at least 3 silicon atoms in one molecule and/or a partial hydrolysis condensate thereof, other than the components (A), (C), and (D): 0.1 to 50 parts by mass; (C) curing catalyst: 0.01 to 20 parts by mass; (D) silane coupling agent: 0.1 to 10 parts by mass; (E) pH indicator: 0.01 to 10 parts by mass. HO (SiR) 2 O) n H (1))

1. A room-temperature-curable organopolysiloxane composition which changes color from an uncured state as curing progresses, comprising:

(A) an organopolysiloxane represented by the following general formula (1) and/or (2): 100 parts by mass of a water-soluble polymer,

[ solution 1]

HO(SiR₂O)_nH (1)

Wherein R is the same or different C1-10 monovalent hydrocarbon group substituted by unsubstituted or halogen atom, n is an integer of 10 or more,

[ solution 2]

Wherein R and n are as defined above, X is an oxygen atom or an alkylene group having 2 to 5 carbon atoms, m is independently 0 or 1,

(B) an organosilicon compound having at least 3 hydrolyzable groups bonded to silicon atoms in one molecule and/or a partial hydrolysis condensate thereof, other than the components (A), (C) and (D): 0.1 to 50 parts by mass of a stabilizer,

(C) curing catalyst: 0.01 to 20 parts by mass of a stabilizer,

(D) silane coupling agent: 0.1 to 10 parts by mass of a stabilizer,

(E) pH indicator: 0.01 to 10 parts by mass.

2. The room-temperature-curable organopolysiloxane composition according to claim 1, further comprising 0.1 to 20 parts by mass of a solvent as component (F) per 100 parts by mass of component (A).

3. The room-temperature-curable organopolysiloxane composition according to claim 2, which is obtained by uniformly dispersing component (E) dissolved in component (F) in a mixture containing component (A), component (B), component (C), and component (D).

4. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 3, wherein component (D) is an alkaline silane coupling agent.

5. The room temperature-curable organopolysiloxane composition according to any one of claims 1 to 4, further comprising 1 to 500 parts by mass of at least one inorganic filler as component (G) per 100 parts by mass of component (A).

6. A room temperature-curable organopolysiloxane composition according to any one of claims 1 to 5, wherein component (E) is a pH indicator that changes color in the alkaline region.

7. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 6, wherein the degree of progress of curing can be visually confirmed by a color change.

8. A structure having a cured product layer of the room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 7.

9. A method for determining the cured state of a room-temperature-curable organopolysiloxane composition, comprising the steps of: it is considered that the room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 7 is cured at room temperature by moisture in the atmosphere to obtain a silicone rubber cured product that changes color from the hue of the composition in an uncured state.

Technical Field

The present invention relates to a room-temperature-curable organopolysiloxane composition that can visually recognize (judge) the degree of curing from a change in color as curing progresses from an uncured state, a structure using the composition, and a method for judging the cured state of the composition.

Background

Conventionally, room temperature-curable organopolysiloxane compositions and the like have been known as compositions that crosslink and cure by condensation reaction with atmospheric moisture. Room temperature-curable organopolysiloxane compositions are widely used in construction, transportation, electrical and electronic parts, and the like because of their excellent safety, durability as rubbers, and adhesiveness. These moisture-curable room-temperature-curable organopolysiloxane compositions are curing systems that gradually undergo crosslinking (curing reaction) by moisture in the air, and therefore, a certain amount of time is required after application to the site of use until completion of curing. Therefore, in order to determine whether or not the applied composition has cured, it cannot be determined unless it is confirmed by touching with a finger or waiting for a certain time that the composition has become rubbery.

However, when the degree of curing is checked by touching with a finger or the like, if dirt adheres to the finger or the like, the cured product may be contaminated. In addition, when the mobile terminal is in standby for a certain time, the following problems occur: the work takes a long time, the productivity is reduced, and a storage place for the components to be constructed and the like becomes necessary. Further, when a curable composition is used as an adhesive, if the adherend is moved before curing, a normal adhesive force cannot be obtained, and the degree of curing cannot be confirmed.

In addition, the moisture-curable room-temperature-curable organopolysiloxane composition is also affected in the degree of curing by the amount used, the period of use (summer, winter, plum rain, etc.), the shape of the member used, and the like. Therefore, it is very difficult to accurately determine whether or not the moisture-curable room-temperature-curable organopolysiloxane composition has been completely cured. Therefore, in the case of using a moisture-curable room-temperature-curable organopolysiloxane composition, it is an important subject to establish a method by which the degree of curing can be easily confirmed.

In order to overcome the above problem, in recent years, patent document 1 (japanese patent application laid-open No. 2006-213780) uses the following method: by using an organic titanyl catalyst and an organic compound having at least 1 hydroxyl group bonded to a benzene ring in the molecule, a substance obtained by reacting the titanium catalyst with the hydroxyl group is colored, and the color of the composition is decolored or discolored by hydrolysis with moisture in the air, and the degree of curing can be visually confirmed. This publication is effective for a room-temperature-curable organopolysiloxane composition of the dealcoholization type, but cannot be applied to room-temperature-curable organopolysiloxane compositions of the deoximation type and room-temperature-curable organopolysiloxane compositions of the deacetone type which are generally used, and therefore, there is a limit to the application fields in which the degree of curing can be visually confirmed using this composition.

Patent document 2 (japanese patent No. 5882851) proposes the following: by adding cobalt chloride to the room temperature-curable organopolysiloxane composition, the room temperature-curable organopolysiloxane composition changes from gray to cyan while being cured with moisture, and the degree of cure can be determined. However, cobalt chloride has high toxicity, and it is not desirable to use a compound having high toxicity from the viewpoint of recent operator and environmental protection.

The degree of change in hue of the composition accompanying the progress of curing is not clear, and it is not always easy to accurately determine the degree of curing by visual observation.

Further, patent document 3 (japanese patent No. 3743004) reports: in a composition comprising an organic compound having at least one silicon group having a hydroxyl group or a hydrolyzable group, a basic compound, a benzotriazole derivative, and a plasticizer for dissolving the benzotriazole derivative, the color changes from yellow to colorless with curing. However, these compositions require the same or more parts by mass of a plasticizer as the base polymer in the composition, which is an organic compound having at least one or more silicon groups having a hydroxyl group or a hydrolyzable group, and have the following problems: there is a fear that excessive addition of the plasticizer causes deterioration of rubber properties of a cured product and oil bleeding.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a room temperature curable organopolysiloxane composition in which the color tone (hue) of the composition greatly changes when the composition is cured at room temperature by moisture in the atmosphere, the degree of cure of the composition can be accurately and easily visually recognized (determined), a highly toxic compound is not contained, safety is excellent, and the obtained cured product (silicone rubber cured product) has good physical properties, a structure using the composition, and a method for determining the cured state of the composition.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that: the present inventors have completed the present invention by adding a pH indicator, preferably a pH indicator which changes color in the basic region, and a silane coupling agent, preferably a basic silane coupling agent, to a moisture-curable room-temperature-curable resin composition to obtain a room-temperature-curable organopolysiloxane composition which is not restricted by the curing type of the composition (i.e., dealcoholization type, deoximation type, deacetonization type, deacetylation type, deamination type, etc.) and which has a clear color change accompanying curing even without using a highly toxic compound.

Accordingly, the present invention provides the following room-temperature-curable organopolysiloxane composition, a structure having a cured product layer of the composition, and a method for determining the cured state of the composition.

[1] A room-temperature-curable organopolysiloxane composition which changes color from an uncured state as curing progresses, comprising:

(A) an organopolysiloxane represented by the following general formula (1) and/or (2): 100 parts by mass of a water-soluble polymer,

[ solution 1]

HO(SiR2O)H (1)

(wherein R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which is unsubstituted or substituted with a halogen atom, and n is an integer of 10 or more.) though the same or different

[ solution 2]

(wherein R and n are as defined above, X is an oxygen atom or an alkylene group having 2 to 5 carbon atoms, and m is independently 0 or 1.)

(B) An organosilicon compound having at least 3 hydrolyzable groups bonded to silicon atoms in one molecule and/or a partial hydrolysis condensate thereof, other than the components (A), (C) and (D): 0.1 to 50 parts by mass of a stabilizer,

(C) curing catalyst: 0.01 to 20 parts by mass of a stabilizer,

(D) silane coupling agent: 0.1 to 10 parts by mass of a stabilizer,

(E) pH indicator: 0.01 to 10 parts by mass.

[2] [1] the room-temperature-curable organopolysiloxane composition further comprises, as component (F), 0.1 to 20 parts by mass of a solvent per 100 parts by mass of component (A).

[3] [2] the room-temperature-curable organopolysiloxane composition described above, which is obtained by uniformly dispersing component (E) dissolved in component (F) in a mixture containing component (A), component (B), component (C), and component (D).

[4] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [3], wherein the component (D) is a basic silane coupling agent.

[5] The room-temperature-curable organopolysiloxane composition of any one of [1] to [4], further comprising 1 to 500 parts by mass of at least one inorganic filler as component (G) per 100 parts by mass of component (A).

[6] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [5], wherein the component (E) is a pH indicator that changes color in a basic region.

[7] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [6], wherein the degree of progression of curing can be visually confirmed by a change in color.

[8] A structure having a cured product layer of the room-temperature-curable organopolysiloxane composition according to any one of [1] to [7 ].

[9] A method for determining the cured state of a room-temperature-curable organopolysiloxane composition, comprising the steps of: it is considered that the room-temperature-curable organopolysiloxane composition according to any one of [1] to [7] is cured at room temperature by atmospheric moisture to obtain a silicone rubber cured product that changes color from the hue of the composition in an uncured state.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a room-temperature-curable organopolysiloxane composition in which the degree of curing can be visually recognized (judged) from a change in color as curing proceeds from an uncured state, a structure using the composition, and a method for judging the cured state of the composition.

Further, the resin composition can be used in the same manner as conventional products because workability and rubber properties are not changed as compared with conventional room-temperature-curable organopolysiloxanes. The present invention can be suitably used in the fields of construction, transportation, and electrical/electronic components, and particularly in the fields where it is necessary to check the presence or absence of curing in a relatively short time (transportation, electrical/electronic components, and the like).

Specifically, the room-temperature-curable organopolysiloxane composition of the present invention as described above can impart a function of changing sharply the color tone at the completion of curing from the uncured state as the curing proceeds to a moisture-curable room-temperature-curable organopolysiloxane composition. In the present invention, "room temperature" means 23 ℃. + -. 15 ℃.

Further, the room temperature-curable organopolysiloxane composition changes color as curing proceeds from an uncured state, and the degree of progress of curing (completion of curing) can be visually confirmed.

Such an organopolysiloxane composition that changes color with curing can be expected to reduce contamination of the cured product by touch confirmation and improve work efficiency.

The room temperature-curable organopolysiloxane composition can be added with a solvent that dissolves (E) as component (F).

Further, the room-temperature-curable organopolysiloxane composition is more preferably a composition in which the component (E) dissolved in the component (F) is uniformly dispersed in a mixture containing the components (a) to (D).

In this way, if the component (E) is dissolved in the component (F) in advance, the dispersibility of the mixture containing the components (A) to (D) can be improved.

In addition, the room temperature-curable organopolysiloxane composition of the present invention can contain an inorganic filler as component (G) within a range that does not impair the functions of the present invention.

Further, the present invention can provide a structure in which a cured product layer of a room-temperature-curable organopolysiloxane composition is adhered (has the cured product layer), and a method for determining the cured state of a room-temperature-curable organopolysiloxane composition, comprising the steps of: it was confirmed that the room temperature-curable organopolysiloxane composition was cured at room temperature by atmospheric moisture to obtain a silicone rubber cured product that had been discolored from the hue of the composition in an uncured state.

Therefore, the room temperature-curable organopolysiloxane composition of the present invention can be suitably used as an adhesive for various members used in transportation equipment such as automobiles, an adhesive for electric and electronic components, a sealing material, a coating agent for fiber products, glass products, metal products, plastic products, and the like, an adhesive, and an application as a sealing material for buildings.

In the room-temperature-curable organopolysiloxane composition of the present invention, the mechanism of discoloration associated with curing is discoloration due to a pH indicator. In general, since a room-temperature-curable organopolysiloxane composition is cured by the progress of a condensation reaction (crosslinking reaction) caused by moisture (moisture) in the atmosphere, when the composition is stored in an uncured state, when the composition is stored in a state of being blocked from the atmosphere (outside air) and cured, and the composition is exposed to the atmosphere containing moisture (moisture), by containing a pH indicator and a specific silane coupling agent having acidity or basicity in the composition (making them coexist), so that when the composition adsorbs moisture (water) in the atmosphere from the surface, the adsorbed moisture (water) permeates into the system of the composition (or cured product), when effective moisture is present in the system (in the composition or in the cured product), discoloration occurs due to a change in pH caused by the coexistence of the moisture and the silane coupling agent. However, in the moisture-curable resin composition before the start of the curing reaction and/or in the middle of the progress of the curing reaction (before the completion of the curing reaction), since moisture in the atmosphere that enters the composition system (in the matrix) from the surface of the composition is preferentially consumed by the curing reaction (condensation reaction) of the composition until the completion of the curing of the composition, effective moisture that contributes to the color development of the pH indicator is not present in the system (in the matrix), the color is not changed until the completion of the curing reaction, and the color development starts after the completion of the curing reaction. That is, in the room temperature-curable organopolysiloxane composition of the present invention, the color tone (hue) of the composition (or cured product) changes from the hue of the composition itself (usually colorless and transparent, or the hue of the filler itself other than white or white due to the presence of the filler in the case where a filler such as an inorganic filler is contained) in which the influence of the color development of the pH indicator does not exist, to the hue of the color development of the pH indicator after the time point when the curing reaction is completed. Therefore, if the discoloration mechanism of the present invention is used, a more definite uncured/cured state can be visually recognized (discriminated) than in the prior art.

Detailed Description

The present invention will be described in more detail below.

< Room temperature-curable organopolysiloxane composition >

The room-temperature-curable organopolysiloxane composition of the present invention contains the following components (a) to (E).

[ (A) component ]

The organopolysiloxane of component (a) used in the room-temperature-curable organopolysiloxane composition of the present invention functions as a main agent (base polymer) of the composition of the present invention and is represented by general formula (1) and/or (2) below.

[ solution 3]

HO(SiR₂O)_nH (1)

(wherein R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which is unsubstituted or substituted with a halogen atom, and n is an integer of 10 or more.) though the same or different

[ solution 4]

(wherein R is the same or different C1-10 unsubstituted or halogen atom-substituted monovalent hydrocarbon group, n is an integer of 10 or more, X is an oxygen atom or C2-5 alkylene group, and m is independently 0 or 1.)

In the general formulae (1) and (2), R is a monovalent hydrocarbon group having 1 to 10 carbon atoms and being unsubstituted or substituted with a halogen atom, and examples thereof include alkyl groups such as methyl, ethyl, and propyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl; and those in which a hydrogen atom bonded to a carbon atom is partially substituted with a halogen atom, for example, 3, 3, 3-trifluoropropyl group. Among these, methyl, vinyl, phenyl and 3, 3, 3-trifluoropropyl are preferred, and methyl is particularly preferred. The plural R in the general formulae (1) and (2) may be the same group or different groups.

N is an integer of 10 or more, particularly an integer in which the viscosity of the diorganopolysiloxane at 25 ℃ is in the range of 25 to 500000 mPas, preferably in the range of 500 to 100000 mPas. In the present invention, the viscosity is a value at 25 ℃ measured by a rotational viscometer (for example, a BL type, BH type, BS type, cone type, rheometer, etc.). The value of n for imparting such a viscosity is, specifically, usually 10 to 2000, preferably 20 to 1500, and more preferably an integer of about 50 to 1000. In the present invention, the polymerization degree (or molecular weight) can be generally determined as a number average polymerization degree (number average molecular weight) in terms of polystyrene in Gel Permeation Chromatography (GPC) analysis using toluene or the like as a developing solvent.

In the general formula (2), X represents an oxygen atom or an alkylene group having 2 to 5 carbon atoms, and examples of the alkylene group having 2 to 5 carbon atoms include an ethylene group, a propylene group, and a butylene group. Among these, an oxygen atom and an ethylene group are preferable as X.

m is independently 0 or 1.

[ (B) component ]

The component (B) used in the room-temperature-curable organopolysiloxane composition of the present invention functions as a crosslinking agent (curing agent) and is a hydrolyzable organosilicon compound and/or a partial hydrolysis condensate thereof other than the component (a) and the components (C) and (D) described later, having at least 3 hydrolyzable groups bonded to silicon atoms in one molecule, and as the organosilicon compound, a hydrolyzable organosilane compound and/or a partial hydrolysis condensate thereof represented by the following general formula (3) (i.e., an organosiloxane oligomer having at least 2, preferably 3 or more residual hydrolyzable groups in the molecule, which is produced by partially hydrolytically condensing the organosilane compound) is preferred.

[ solution 5]

R⁴ _cSiR⁵ _4-c(3)

(in the formula, R⁴Is an unsubstituted monovalent hydrocarbon radical, R⁵Is a hydrolyzable group. c is 0 or 1, preferably 1. )

In the general formula (3), as the hydrolyzable group R⁵Examples thereof include a ketoximino group, an alkoxy group, an acyloxy group, and an alkenyloxy group. Specifically, examples thereof include ketoximino groups having 3 to 8 carbon atoms such as dimethylketoximino group, methylethylketoximino group and methylisobutylketonximino group, acyloxy groups having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group and tert-butoxy group, particularly acyloxy groups having 2 to 4 carbon atoms such as 1 or 2 alkoxy group, acetoxy group and propionyloxy group, and alkenyloxy groups having 2 to 4 carbon atoms such as vinyloxy group, allyloxy group, propenyloxy group and isopropenyloxy group.

In addition, the residual group R bonded to the silicon atom other than the hydrolyzable group⁴The monovalent hydrocarbon group is not particularly limited as long as it is an unsubstituted monovalent hydrocarbon group, and specifically, an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, an alkenyl group such as a vinyl group, or an aryl group such as a phenyl group is exemplified. Of these, methyl, ethyl, vinyl and phenyl are preferable.

Specific examples of the component (B) include ketoximinosilanes such as tetrakis (methylethylketoximo) silane, methyltris (dimethylketoximo) silane, methyltris (methylethylketoximo) silane, ethyltris (methylethylketoximo) silane, methyltris (methylisobutylketonximo) silane and vinyltris (methylethylketoximo) silane, methyltrimethoxysilane, vinyltrimethoxysilane and phenyltrimethoxysilane, alkoxysilanes such as tetramethoxysilane, vinyltriethoxysilane, and tetraethoxysilane, acetoxysilanes such as methyltriacetoxysilane and vinyltriacetoxysilane, isopropenoxysilanes such as methyltriisopropenoxysilane, vinyltriisopropenoxysilane, and phenyltriisopropenoxysilane, and partial hydrolysis condensates of these silanes. These can be used alone 1 or more than 2.

Furthermore, the first and second electrodes are provided with,(B) the component having no moiety of formula (SiR)₂O)_nThe repeating structure of the linear diorganosiloxane unit is clearly different from the component (A), and the repeating structure of the linear diorganosiloxane unit is clearly different from the component (D) described later, in that the repeating structure does not contain a 1-valent hydrocarbon group having a functional group containing a heteroatom such as nitrogen, oxygen, or sulfur in the molecule.

The amount of component (B) is 0.1 to 50 parts by mass, preferably 5 to 30 parts by mass, based on 100 parts by mass of component (A). If the amount is less than 0.1 part by mass, sufficient crosslinking is not obtained, and it is difficult to obtain a desired composition having rubber elasticity, and if it exceeds 50 parts by mass, the mechanical properties of the obtained cured product tend to be deteriorated.

[ (C) ingredient ]

The component (C) used in the room-temperature-curable organopolysiloxane composition of the present invention is a curing catalyst. As the curing catalyst, a condensation catalyst which has been generally used as a curing accelerator for moisture (condensation) curable compositions can be used. Examples thereof include organic tin compounds such as dibutyltin methoxide, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dioctyltin dioctanoate, dimethoxydimethyltin and dimethyltin diacetate; organic titanium compounds such as tetrapropyl titanate, tetrabutyl titanate, tetra-2-ethylhexyl titanate, dimethoxytitanium diacetone, and the like; amine compounds such as hexylamine, 3-aminopropyltrimethoxysilane and tetramethylguanidinopropyltrimethoxysilane, and salts thereof, and 1 of these may be used alone or 2 or more may be used in combination.

The amount of component (C) is 0.01 to 20 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of component (A). If the amount of component (C) is less than 0.01 parts by mass, which is the lower limit, the catalytic effect cannot be obtained. If the amount of component (C) exceeds 20 parts by mass, which is the upper limit, the room temperature-curable organopolysiloxane composition may have reduced adhesiveness or poor storage stability.

[ (D) component ]

The component (D) used in the room-temperature-curable organopolysiloxane composition of the present invention is a silane coupling agent (i.e., a hydrolyzable silane compound containing a functional group (so-called a carbon-functional silane compound) having, in 1 molecule, a 1-valent hydrocarbon group having a functional group containing a heteroatom such as nitrogen, oxygen, or sulfur and a plurality of (2 or 3) hydrolyzable groups, and/or a partial hydrolysis condensate thereof). The purpose of adding the silane coupling agent is to promote the discoloration of the pH indicator at the completion of curing described later by adjusting the pH in the composition (to a specific range), and to improve the adhesiveness of a cured product (silicone rubber) obtained by curing the composition.

As the component (D), a generally used silane coupling agent can be used. Examples of the component (D) include gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, gamma-aminopropylmethyldimethoxysilane, gamma-aminopropylmethyldiethoxysilane, N-beta-aminoethyl-gamma-aminopropylmethyldimethoxysilane, N-benzyl-gamma-aminopropyltrimethoxysilane, N-phenyl-gamma-aminopropyltrimethoxysilane, beta-aminoethylaminomethylphenethyltrimethoxysilane, N- [ m-aminomethylphenylmethyl ] -gamma-aminopropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-epoxycyclohexyl) ethyltrimethoxysilane, and mixtures thereof, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, mercapto 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, tetramethylguanidinopropyltrimethoxysilane, tetramethylguanidinopropylmethyldimethoxysilane, and partial/cohydrolyzates thereof. Further, 1 of these may be used alone or 2 or more may be used in combination.

The type of the component (D) is particularly preferably an alkaline silane coupling agent, and particularly preferably one having one or more primary amino groups, secondary amino groups, tertiary amino groups, or guanidine groups in the molecule. Examples of the silane coupling agent (basic silane coupling agent, particularly an amino group-containing silane coupling agent) include γ -aminopropyltriethoxysilane, γ -aminopropyltrimethoxysilane, γ -aminopropylmethyldimethoxysilane, γ -aminopropylmethyldiethoxysilane, N- β -aminoethyl- γ -aminopropylmethyldimethoxysilane, N-benzyl- γ -aminopropyltrimethoxysilane, N-phenyl- γ -aminopropyltrimethoxysilane, β -aminoethylaminomethylphenethyltrimethoxysilane, N- [ m-aminomethylphenylmethyl ] - γ -aminopropyltrimethoxysilane tetramethylguanidinopropyltrimethoxysilane, tetramethylguanidinopropylmethyldimethoxysilane and the like, these silane coupling agents may be used alone or in combination of 2 or more, and these silane coupling agents may be used in combination with a non-basic, particularly neutral silane coupling agent.

The amount of component (D) is 0.1 to 10 parts by mass, preferably 0.3 to 8 parts by mass, and more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of component (A). If the amount of the component (D) is less than 0.1 part by mass, which is the lower limit, sufficient discoloration and adhesion may not be obtained. If the amount of component (D) exceeds 10 parts by mass, which is the upper limit, the physical properties of the room temperature-curable organopolysiloxane composition may deteriorate or storage stability may deteriorate.

[ (E) ingredient ]

The component (E) used in the room-temperature-curable organopolysiloxane composition of the present invention is a pH indicator. (E) The component (c) is used in combination with the silane coupling agent of the component (D), preferably a basic silane coupling agent, to impart the following functions to the moisture-curable resin according to the above-described mechanism: with curing, the color changes upon completion of curing.

As the component (E), a commonly used pH indicator can be used. (E) The pH indicator of the component (a) may be solid or liquid at room temperature, and is preferably a liquid pH indicator in view of dispersibility, discoloration, and the like.

(E) The pH indicator of the component (A) preferably changes color in an alkaline pH range, and particularly, the pH change range is 7 to 14, more preferably 7.5 to 13, and still more preferably 8 to 12.

Examples of the pH indicator of the component (E) having such a pH variable region include phenolphthalein, thymolphthalein, alizarin yellow R, cresolphthalein, cresol red, phenol red, bromothymol blue, and the like, and 1 of these may be used alone or 2 or more may be used in combination. The pH indicator of component (E) may be a product obtained by dissolving component (F) in a solvent.

The amount of component (E) is 0.01 to 10 parts by mass, preferably 0.1 to 8 parts by mass, and more preferably 1 to 6 parts by mass, per 100 parts by mass of component (A). If the amount of the component (E) is less than 0.1 part by mass, which is the lower limit, sufficient discoloration may not be obtained. If the amount of component (E) exceeds 10 parts by mass, which is the upper limit value, the pH indicator may precipitate on the surface of the cured product of the room-temperature-curable organopolysiloxane composition or the appearance of the cured product may deteriorate.

[ (F) ingredient ]

The component (F) used in the room-temperature-curable organopolysiloxane composition of the present invention is an optional component that can be blended as needed, and is a solvent for dissolving the component (E). If the component (E) alone is not well dispersed in the component (A), the dispersibility can be improved by adding the component (F) or by adding a product obtained by dissolving the component (E) in the component (F) in advance.

As the component (F), a generally used organic solvent can be used. For example, the component (F) may be a polar or nonpolar organic solvent such as methanol, ethanol, acetone, cyclohexanone, tetrahydrofuran, benzene, toluene, xylene, dimethylformamide, acetonitrile, ethyl acetate, cyclohexane, methylcyclohexane, or the like, and 1 of them may be used alone or 2 or more of them may be used in combination.

When component (F) is blended, the blending amount is 0.1 to 20 parts by mass, preferably 0.5 to 15 parts by mass, and more preferably 1 to 10 parts by mass, relative to 100 parts by mass of component (A). If the amount of the component (F) is less than 0.1 part by mass, which is the lower limit, the effect of dispersing the component (E) may not be sufficiently obtained. If the amount of component (F) is more than 20 parts by mass, which is the upper limit, the physical properties of the room-temperature-curable organopolysiloxane cured product may deteriorate.

[ (G) ingredient ]

The inorganic filler (G) is an optional component which may be blended as necessary, and is a reinforcing filler or a non-reinforcing filler for imparting rubber properties to the cured product of the room-temperature-curable organopolysiloxane composition of the present invention which changes color with curing.

The present filler may be exemplified by inorganic fillers having been surface-treated or not treated as follows. That is, examples of the silica-based filler include dry silica such as fumed silica and fumed silica, precipitated silica, wet silica such as sol-gel silica, and the like; carbon black, talc, bentonite, calcium carbonate, zinc carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, aluminum hydroxide, and the like. Among them, calcium carbonate, fumed silica, precipitated silica, carbon black, and alumina are preferable, and calcium carbonate, fumed silica, precipitated silica, carbon black, and alumina, in which the surface of the inorganic filler is hydrophobized, are more preferable. In this case, the inorganic filler preferably has a small water content. The type, amount, treatment method, and the like of the surface treatment agent are not particularly limited, and a known treatment method using a treatment agent such as an organosilicon compound such as chlorosilane, alkoxysilane, or organosilazane, a fatty acid, paraffin, a silane coupling agent, or a titanium coupling agent can be typically used. One of these may be used alone or two or more of these may be used in combination.

When the component (G) is blended, the blending amount thereof is in the range of 1 to 500 parts by mass, preferably 20 to 300 parts by mass, relative to 100 parts by mass of the organopolysiloxane of the component (A). If the amount of component (G) is less than 1 part by mass, which is the lower limit, the room-temperature-curable organopolysiloxane composition obtained cannot have sufficient rubber strength. Further, if the blending amount of the component (G) exceeds 500 parts by mass, which is the upper limit value, the discharge from the ink cartridge is deteriorated and the storage stability may be lowered.

In addition, in the room temperature-curable organopolysiloxane composition of the present invention, generally known additives can be used in addition to the above components within a range that does not impair the object of the present invention. Examples of the additive include polyether as a thixotropy enhancer, silicone oil as a plasticizer, isoparaffin, and the like, and if necessary, a colorant such as a pigment, a dye, a fluorescent brightener, and the like, a colorant such as a fungicide, an antibacterial agent, a marine organism repellent, and the like, a surface modifier such as phenyl silicone oil, fluorosilicone oil, an organic liquid incompatible with silicone, and the like as a penetrating oil, a solvent volatile oil, low-boiling isoparaffin, an organic resin filler, and the like can be added.

< preparation and shaping of the composition >

The room-temperature-curable organopolysiloxane composition of the present invention can be prepared by mixing components (a) to (E) that constitute the essential components of the composition, and components (F) and (G) that are optional components added as needed, using a known mixing machine such as a kneader, a banbury mixer, or a two-roll mixer. As described above, when the component (E) alone is not well dispersed in the component (a), the dispersibility can be improved by adding the component (F) or a product obtained by dissolving the component (E) in the component (F) in advance. In this case, it is preferable that a product obtained by dissolving the component (E) in the component (F) is uniformly dispersed in a mixture containing the components (a) to (D).

As the molding method, a known molding method can be selected according to the shape and size of the target molded article. Examples of the method include casting, compression molding, injection molding, calendering, and extrusion. The molding thickness is usually 0.1 to 100mm, preferably 1 to 50 mm.

The curing conditions for the color of the composition may be known conditions in the molding method used, and can be confirmed with the naked eye in an atmosphere of 23. + -.15 ℃ and 50. + -.20% RH, preferably 23. + -.5 ℃ and 50. + -.10% RH, usually 1 to 10 days, preferably 3 to 7 days from the initial stage of molding. Among them, it is necessary for a cured product of the composition to be confirmed by touch; the rubber has good physical properties and less aggregates. The physical properties (hardness, elongation, and tensile strength) of the rubber were evaluated in accordance with JIS-K6249.

< Structure Using composition and method for determining curing State >

The present invention can provide a structure having a cured product of a room-temperature-curable organopolysiloxane composition. Examples of such a structure include transportation equipment such as automobiles including engine units, water pumps, transmission units, etc. obtained by sealing, bonding, or coating fiber products, glass products, metal products, plastic products, etc. with a cured product of the composition; electric and electronic components such as engine control units, which are obtained by sealing, bonding, or coating components such as electronic boards and cases with a cured product of the composition; or building members such as building exterior walls, window frames, water-use parts (kitchens, toilets, bathrooms), display cases, etc. which are obtained by sealing, bonding, or coating fiber products, glass products, metal products, plastic products, etc. with a cured product of the above composition. Particularly, it is applicable to a transport facility, an electric/electronic component, and the like, which require a relatively short time to check the presence or absence of curing.

The present invention can also provide a method for determining the cured state of a room-temperature-curable organopolysiloxane composition, comprising the steps of: it was confirmed that a cured silicone rubber product in which the hue of a room temperature-curable organopolysiloxane composition was changed from the uncured state was obtained by curing the composition at room temperature using moisture in the atmosphere. This makes it possible to easily determine the uncured/cured state of the composition by visual observation. The mechanism of discoloration associated with curing is as described above.

Therefore, the room temperature-curable organopolysiloxane composition of the present invention can be suitably used as an adhesive for various members used in transportation equipment such as automobiles, a sealing material for electric and electronic components, an adhesive, a coating agent for moisture proofing, a coating agent for fiber products, glass products, metal products, plastic products, and the like, an adhesive, and an application as a sealing material for buildings, and can provide a useful structure and a method for easily determining the uncured/cured state by visual observation.