Aldimine-modified silicone, moisture-curable silicone resin composition containing same, and method for producing said aldimine-modified silicone

Abstract

The present invention is an aldimine-modified silicone represented by formula (1). Formula (1): (AR1 2SiO1 / 2)a(R1 2SiO2 / 2)b(R1SiO3 / 2)c(SiO4 / 2)d (In this formula, A is an aldimine group represented by formula (2), each R1 is independently a C1-10 monovalent hydrocarbon group, a satisfies 2 ≤ a ≤ 5, b satisfies 0 < b ≤ 200, c satisfies 0 ≤ c ≤ 1, d satisfies 0 ≤ d ≤ 1, and 2 ≤ a + b + c + d ≤ 200 is satisfied.)　Formula (2): -Q1-CH=N-R2 (In this formula, Q1 is a C2-10 divalent hydrocarbon group, and R2 is a C1-10 monovalent hydrocarbon group.)　In view of the above, provided are an aldimine-modified silicone and a method for producing said aldimine-modified silicone which make long-term single-liquid storage of a silicone resin composition possible without chemically modifying a polyamine compound.

Description

Aldimine-modified silicone, moisture-curable silicone resin composition containing the same, and method for producing the aldimine-modified silicone

[0001] The present invention relates to an aldimine-modified silicone, a moisture-curable silicone resin composition containing the aldimine-modified silicone, and a method for producing the aldimine-modified silicone.

[0002] Silicone resin compositions are known that contain modified silicones containing reactive functional groups such as aldehydes, acid anhydrides, acrylics, maleimides, and epoxy groups, and polyamine compounds as crosslinkers. However, because the reaction rate of these compositions is fast, they are difficult to store for long periods of time in the form of a mixture known as a one-component composition.

[0003] A method for improving the storage stability of the one-component composition is known, in which a ketone compound is reacted with the polyamine compound to form a polyketimine compound (Patent Documents 1 and 2). However, the polyketimine compound is not suitable for long-term storage over several months to several years because the nitrogen atoms on the ketimine group still have nucleophilicity.

[0004] JP-A-5-271389 JP-A-10-060227

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an aldimine-modified silicone that enables long-term storage of a one-component silicone resin composition without chemically modifying the polyamine compound, and a method for producing the same.

[0006] In order to solve the above problems, the present invention provides the following aldimine-modified silicone, a moisture-curable silicone resin composition containing the same, and a method for producing the aldimine-modified silicone.

[0007] That is, the present invention provides an aldimine-modified silicone represented by the following formula (1): (AR １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO４／２ ) d (1) (wherein A is an aldimine group represented by the following formula (2), and R １ are independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, a is 2≦a≦5, b is 0<b≦200, c is 0≦c≦1, and d is 0≦d≦1, provided that 2≦a+b+c+d≦200. １ -CH=N-R ２ (2) (wherein, Q １ is a divalent hydrocarbon group having 2 to 10 carbon atoms, and R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0008] The aldimine-modified silicone of the above formula (1) is preferably one represented by the following formula (3): (Wherein, A and R １ is the same as the above formula (1), and e is a number from 1 to 150.

[0009] These aldimine-modified silicones have excellent storage stability when made into moisture-curable silicone resin compositions containing polyamine compounds, and are well balanced with respect to the rate of moisture-induced curing.

[0010] The present invention provides a moisture-curable silicone resin composition comprising the aldimine-modified silicone of the present invention and a polyamine compound.

[0011] In the moisture-curable silicone resin composition of the present invention, the polyamine compound is preferably an amino-modified silicone represented by the following formula (7): (In the formula, R １ are independently the same as in formula (1), and R Ａ is an amino group represented by the following formula (8), where f is a number from 1 to 200, and g is a number from 2 to 50. (In the formula, Q ２ is an alkylene group having 1 to 8 carbon atoms, and h is an integer of 0 to 4.

[0012] The moisture-curable silicone resin composition of the present invention has the property of curing in the atmosphere, yet can remain liquid at room temperature in a sealed container.

[0013] The present invention provides a method for producing the aldimine-modified silicone of the present invention represented by the above formula (1) below, which method comprises reacting an aldehyde-modified silicone represented by the following formula (4) with a primary amine compound represented by the following formula (6): (A'R １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO ４／２ )d (4) (wherein, R １ are independently the same as those in the formula (1), a, b, c and d are also the same as those in the formula (1), and A′ is a group represented by the following formula (5) (wherein, Q １ is the same as the above formula (2). ) is an aldehyde group represented by the formula (2). -Q １ -CH=O (5) H ２ N-R ２ (6) (wherein, R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0014] The above production method makes it possible to produce an aldimine-modified silicone suitable for use in the moisture-curable silicone resin composition of the present invention.

[0015] The aldimine-modified silicone of the present invention has excellent storage stability when made into a moisture-curable silicone resin composition containing a polyamine compound, and has a good balance with the moisture-induced cure rate. The moisture-curable silicone resin composition can be used as a resin modifier, sealant, pressure-sensitive adhesive, adhesive, etc.

[0016] As described above, there has been a need for the development of a moisture-curable silicone resin composition that can be stored for a long period of time as a one-component silicone resin composition without chemically modifying the polyamine compound.

[0017] As a result of extensive research aimed at solving the above problems, the present inventors discovered that an aldimine-modified silicone obtained from an aldehyde-modified silicone and a primary amine can be stored for a long period of time as a one-part composition when combined with a polyamine compound, and thus completed the present invention.

[0018] That is, the present invention relates to an aldimine-modified silicone represented by the above formula (1), a moisture-curable silicone resin composition containing the same, and a method for producing the aldimine-modified silicone.

[0019] The present invention will be described in detail below, but the present invention is not limited thereto.

[0020] [Aldimine-modified silicone] The aldimine-modified silicone of the present invention is represented by the following formula (1): (AR １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO ４／２ ) d (1)

[0021] In the above formula (1), R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, preferably selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms. Examples of alkyl groups having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl; and cycloalkyl groups such as cyclopentyl and cyclohexyl. Examples of aryl groups having 6 to 10 carbon atoms include phenyl, tolyl, xylyl, and naphthyl. Examples of aralkyl groups having 7 to 10 carbon atoms include benzyl and phenethyl. Among these, methyl, butyl, phenyl, and benzyl are preferred, and methyl and butyl are more preferred.

[0022] In the above formula (1), a is 2≦a≦5, preferably 2, b is 0<b≦200, preferably 1≦b≦100, more preferably 5≦b≦60, c is 0≦c≦1, preferably 0, and d is 0≦d≦1, preferably 0, provided that 2≦a+b+c+d≦200, preferably 2≦a+b+c+d≦100, more preferably 2≦a+b+c+d≦60.

[0023] In the above formula (1), if a is less than 2, the moisture curing properties of the silicone resin composition will be insufficient, and if it exceeds 5, the stability of the raw material aldehyde-modified silicone (4) will deteriorate, making preparation difficult, which is undesirable. Also, if b exceeds 200, compatibility with the polyamine compound will deteriorate, and if c and d exceed 1, the viscosity will increase, making handling difficult, which is undesirable.

[0024] Furthermore, in the above formula (1), if a+b+c+d is less than 2, the number of siloxane bonds will be less than the minimum required number, and if it exceeds 200, compatibility with the polyamine compound will be insufficient and handleability will be impaired due to an increase in viscosity, which is not preferable.

[0025] A in the above formula (1) is an aldimine group represented by the following formula (2): １ -CH=N-R ２ (2)

[0026] In the above formula (2), Q １ is a divalent hydrocarbon group having 2 to 10 carbon atoms, preferably an alkylene group having 2 to 10 carbon atoms. Examples of the alkylene group having 2 to 10 carbon atoms include an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, and a decamethylene group. Of these, an ethylene group and a heptamethylene group are preferred, and a heptamethylene group is more preferred.

[0027] In the above formula (2), R ２is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and is preferably an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl; and cycloalkyl groups such as cyclopentyl and cyclohexyl.

[0028] Furthermore, a linear aldimine-modified silicone represented by the following formula (3), in which c=d=0 in the above formula (1), is preferred. (Wherein, A and R １ is the same as in the above formula (1), and e is a number from 1 to 150.) In the above formula (3), e is a number from 1 to 150, preferably from 1 to 100, and more preferably from 5 to 60. When e is in the range of 1 or more and 150 or less, excellent compatibility with many polyamine compounds is achieved, and a viscosity that is easy to handle is thus preferred.

[0029] [Moisture-Curable Silicone Resin Composition] The moisture-curable silicone resin composition of the present invention is characterized by containing the aldimine-modified silicone and a polyamine compound.

[0030] The polyamine compound used in the moisture-curable silicone resin composition of the present invention has a structure containing three or more primary or secondary amines, and may be any compound compatible with the aldimine-modified silicone. For example, an amino-modified silicone represented by the following formula (7) can be used. Here, R in formula (7) Ａ is an amino group represented by the following formula (8). (In the formula, R Ａ is an amino group represented by the following formula (8):

[0031] In the above formula (7), f is a number from 1 to 200, preferably a number from 1 to 100, and more preferably a number from 20 to 80. Furthermore, g is a number from 2 to 50, preferably a number from 2 to 25, and more preferably a number from 2 to 10. When f is in the range of 1 or more and 200 or less, the viscosity becomes easy to handle, which is preferable. Furthermore, when g is in the range of 2 or more and 50 or less, the compatibility with the aldimine-modified silicone becomes good, which is preferable.

[0032] In the above formula (8), Q ２is an alkylene group having 1 to 8 carbon atoms, preferably a propylene group, and h is a number from 0 to 4, preferably 0 to 1. When h is 4 or less, compatibility with the aldimine-modified silicone is improved, which is preferable.

[0033] In addition to the above-mentioned main components, the moisture-curable silicone resin composition of the present invention may contain various additives, such as antioxidants such as titanium oxide, pigments such as carbon, fillers such as calcium carbonate, ultraviolet absorbers, plasticizers, etc. These additives may be added in any amounts and in various combinations depending on the intended use of the silicone composition.

[0034] The moisture-curable silicone resin composition of the present invention contains the aldimine-modified silicone of the present invention and a polyamine compound. Therefore, moisture causes the aldimine-modified silicone to produce an aldehyde-modified silicone in the system, which then exhibits addition reactivity with the polyamine compound, thereby exhibiting a curing action. The aldimine-modified silicone blocks moisture, thereby suppressing the production of the aldehyde-modified silicone, thereby improving storage stability.

[0035] [Method for Producing Aldimine-Modified Silicone] The method for producing aldimine-modified silicone of the present invention (hereinafter sometimes abbreviated as "the production method of the present invention") is characterized by having a production step in which the aldehyde group of an aldehyde-modified silicone represented by the following formula (4) is reacted with a primary amine represented by the following formula (6): (A'R １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO ４／２ ) d (4) H ２ N-R ２ (6) (wherein, R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0036] In the above formula (4), R １are preferably independently selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl; and cycloalkyl groups such as cyclopentyl and cyclohexyl. Examples of the aryl group having 6 to 10 carbon atoms include phenyl, tolyl, xylyl, and naphthyl. Examples of the aralkyl group having 7 to 10 carbon atoms include benzyl and phenethyl. Among these, methyl, butyl, phenyl, or benzyl is preferred, with methyl or butyl being more preferred.

[0037] In the above formula (4), a is 2≦a≦5, preferably 2, b is 0<b≦200, preferably 1≦b≦100, more preferably 5≦b≦60, c is 0≦c≦1, preferably 0, and d is 0≦d≦1, preferably 0, provided that 2≦a+b+c+d≦200, preferably 2≦a+b+c+d≦100, more preferably 2≦a+b+c+d≦60.

[0038] In the above formula (6), R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl, and butyl; and cycloalkyl groups such as cyclopentyl and cyclohexyl. Of these, butyl, hexyl, and octyl groups are preferred, with octyl being more preferred.

[0039] A' in the above formula (4) is an aldehyde group represented by the following formula (5): -Q １ —CH═O (5)

[0040] In the above formula (5), Q １is a divalent hydrocarbon group having 2 to 10 carbon atoms, preferably an alkylene group having 2 to 10 carbon atoms. Examples of the alkylene group having 2 to 10 carbon atoms include an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, and a decamethylene group. Of these, an ethylene group and a heptamethylene group are preferred, and a heptamethylene group is more preferred.

[0041] The production method of the present invention is characterized by obtaining an aldimine-modified silicone by reacting an aldehyde-modified silicone with a primary amine. Here, the mixing molar ratio of the aldehyde-modified silicone to the primary amine is preferably in the range of 1.0 to 5.0 moles of primary amine per mole of aminoaldehyde-modified silicone, and more preferably in the range of 1.0 to 2.0 moles. This is because if the number of moles of primary amine per mole of aldehyde-modified silicone is less than this range, highly reactive aldehyde groups derived from the raw aldehyde-modified silicone tend to remain in the final product, while if it exceeds this range, the pot yield during production becomes too low, which is disadvantageous in terms of cost.

[0042] The reaction between the aldehyde-modified silicone and the primary amine proceeds without heating, but may be carried out under heating. The temperature is usually in the range of 10°C to 120°C, and more preferably in the range of 10°C to 60°C.

[0043] In the production method of the present invention, the reaction time is not particularly limited, but is preferably 1 to 24 hours, more preferably 2 to 12 hours, and most preferably 2 to 4 hours.

[0044] The present invention will be explained in more detail below with reference to examples and comparative examples, but modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0045] < １ H-NMR> Described in the examples １H-NMR was measured using an AVANCE-III 400 MHz (manufactured by BRUKER) using deuterated chloroform as a solvent and TMS (tetramethylsilane) as a standard substance.

[0046] Example 1-1 An aldimine-modified silicone represented by the following formula (10) was produced. Specifically, 10.0 g (4.5 mmol) of the aldehyde-modified silicone represented by the following formula (9) was charged, and then 0.59 g (1.0 equivalent) of octylamine was added under a nitrogen atmosphere at 25°C with stirring, and the reaction was carried out at 23°C for 2 hours. １ In H-NMR, the peak at 9.8 ppm derived from the aldehyde group disappeared and a new peak derived from the aldimine group appeared at 7.7 ppm, confirming that an aldimine-modified silicone represented by the following formula (10) was produced.

[0047] Example 1-2 3.83 g (1.0 equivalent) of an amino-modified silicone represented by the following formula (11) was added to the aldimine-modified silicone (formula (10)) obtained in Example 1-1, and the mixture was stirred for 10 minutes at 23° C. to obtain a moisture-curable silicone resin composition. The obtained moisture-curable silicone resin composition had the property of curing in 24 hours in the atmosphere, yet could remain liquid for more than a year at room temperature (25° C.) in a sealed container.

[0048] Example 2-1 In the above Example 1-1, the aldehyde-modified silicone (formula (9)) was changed to the aldehyde-modified silicone represented by the following formula (12), and an aldimine-modified silicone represented by the following formula (13) was obtained by the method described in the above Example 1-1.

[0049] Example 2-2 A moisture-curable silicone resin composition was obtained from aldimine-modified silicone (formula (13)) and amino-modified silicone (formula (11)) by the method described in Example 1-2. The obtained silicone resin composition had the property of curing in 24 hours in the atmosphere, yet could remain liquid at room temperature in a sealed container for more than one year.

[0050] Example 3-1 In the above Example 1-1, the aldehyde-modified silicone (formula (9)) was changed to the aldehyde-modified silicone represented by the following formula (14), and an aldimine-modified silicone represented by the following formula (15) was obtained by the method described in the above Example 1-1.

[0051] Example 3-2 A moisture-curable silicone resin composition was obtained from aldimine-modified silicone (15) and amino-modified silicone (11) by the method described in Example 1-2. The obtained silicone resin composition had the property of curing in 24 hours in the atmosphere, but could remain liquid at room temperature in a sealed container for more than one year.

[0052] Comparative Example 1 In the above Example 1-2, the aldimine-modified silicone (formula (10)) was changed to an aldehyde-modified silicone (formula (9)), and a silicone resin composition was obtained by the method described in the above Example 1-2. The obtained silicone resin composition gelled after 1 minute in a sealed container at room temperature.

[0053] Comparative Example 2 In the above Example 1-2, the aldimine-modified silicone (formula (10)) was changed to an acid anhydride-modified silicone (16) of the following formula (16), and a silicone resin composition was obtained by the method described in the above Example 1-2. The obtained silicone resin composition gelled after 1 minute in a sealed container at room temperature.

[0054] Comparative Example 3 In Example 1-2, the aldimine-modified silicone (formula (10)) was changed to an acrylic-modified silicone (17) of the following formula (17), and a silicone resin composition was obtained by the method described in Example 1-2. The obtained silicone resin composition gelled after 10 minutes in a sealed container at room temperature.

[0055] Comparative Example 4 In Example 1-2, the aldimine-modified silicone (formula (10)) was changed to a maleimide-modified silicone (18) of the following formula (18), and a silicone resin composition was obtained by the method described in Example 1-2. The obtained silicone resin composition gelled after 10 minutes in a sealed container at room temperature.

[0056] Comparative Example 5 In the above Example 1-2, the aldimine-modified silicone (formula (10)) was changed to the epoxy-modified silicone (19) shown below in formula (19), and a silicone resin composition was obtained by the method described in the above Example 1-2. The obtained silicone resin composition gelled after 7 days in a sealed container at room temperature.

[0057] Comparative Example 6 In the above Example 1-2, the aldimine-modified silicone (formula (10)) was changed to the aldimine-modified silicone (20) of the following formula (20), and a silicone resin composition was obtained by the method described in the above Example 1-2. The obtained silicone resin composition did not cure in the air.

[0058] Comparative Example 7 In the above Example 1-2, the aldimine-modified silicone (formula (10)) was changed to an aldehyde-modified silicone (formula (9)), and the amino-modified silicone (formula (11)) was changed to a ketimine-modified silicone represented by the following formula (21), and a silicone resin composition was obtained by the method described in the above Example 1-2. The obtained silicone resin composition gelled after 1 minute in a sealed container at room temperature.

[0059] As shown in Examples 1-2 to 3-2, moisture-curable silicone resin compositions containing the aldimine-modified silicone of the present invention were able to cure in 24 hours in the atmosphere, yet remained liquid for more than a year in a sealed container at room temperature. On the other hand, as shown in Comparative Examples 1 to 7, silicone resin compositions lacking the aldimine-modified silicone of the present invention either gelled in a short time in a sealed container at room temperature, or did not cure in the atmosphere.

[0060] Thus, the aldimine-modified silicone of the present invention has excellent storage stability when made into a moisture-curable silicone resin composition containing a polyamine compound, and a good balance with the moisture-induced cure rate. Furthermore, the present invention has made it possible to obtain a moisture-curable silicone resin composition containing an aldimine-modified silicone that allows for long-term storage of the silicone resin composition in a one-component form without chemically modifying the polyamine compound.

[0061] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

1. An aldimine-modified silicone represented by the following formula (1): (AR １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO ４／２ ) d (1) (wherein A is an aldimine group represented by the following formula (2), R １ are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, a is 2≦a≦5, b is 0<b≦200, c is 0≦c≦1, and d is 0≦d≦1, provided that 2≦a+b+c+d≦200. １ -CH=N-R ２ (2) (wherein, Q １ is a divalent hydrocarbon group having 2 to 10 carbon atoms, R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

2. The aldimine-modified silicone according to claim 1, wherein the aldimine-modified silicone of formula (1) is represented by the following formula (3): (Wherein, A and R １ is the same as in formula (1), and e is a number from 1 to 150.

3. A moisture-curable silicone resin composition comprising the aldimine-modified silicone according to claim 1 and a polyamine compound.

4. The moisture-curable silicone resin composition according to claim 3, wherein the polyamine compound is an amino-modified silicone represented by the following formula (7): (In the formula, R １ are independently the same as those in formula (1), and R Ａ is an amino group represented by the following formula (8), f is a number from 1 to 200, and g is a number from 2 to 50. (In the formula, Q ２ is an alkylene group having 1 to 8 carbon atoms, and h is an integer of 0 to 4.

5. A method for producing the aldimine-modified silicone represented by formula (1) of claim 1, comprising reacting an aldehyde-modified silicone represented by formula (4) below with a primary amine compound represented by formula (6) below. (A'R １ ２ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) c(SiO ４／２ )d (4) (wherein, R １ are independently the same as those in the formula (1), a, b, c and d are also the same as those in the formula (1), and A′ is represented by the following formula (5) (wherein, Q １ is the same as the above formula (2). １ -CH=O (5) H ２ N-R ２ (6) (wherein, R ２ is a monovalent hydrocarbon group having 1 to 10 carbon atoms.

Images