JP7816183B2 - Acrylic and alkenyl group-containing organopolysiloxane and method for producing same - Google Patents

Description

The present invention relates to organopolysiloxanes containing acrylic and alkenyl groups that have specific properties and a method for producing the same.

Traditionally, the synthesis of acrylic group-containing organopolysiloxanes has been carried out using strong acidic catalysts, as the equilibration reaction hardly progresses with basic catalysts. Examples of catalysts used include sulfuric acid and trifluoromethanesulfonic acid. However, synthesis using sulfuric acid or trifluoromethanesulfonic acid takes time for the equilibration reaction of acrylic group-containing organopolysiloxanes to proceed, requiring more than 360 minutes for the percentage of residual raw material peaks calculated by toluene GPC to fall below 10% of the total. Furthermore, if the amount of sulfuric acid or trifluoromethanesulfonic acid is increased too much to speed up the reaction, the acrylic groups decompose into hydroxyl groups, and these hydroxyl groups condense with each other, resulting in high molecular weight and high viscosity.

The use of solid acid catalysts such as ion exchange resins has been reported as a highly productive production method. Patent Document 1 (JP 2012-512272 A) describes a method for producing siloxanes, which involves reacting at least two siloxanes in the presence of an ion exchange resin catalyst containing 6 to 19% by mass of water relative to the dry mass of the ion exchange resin catalyst. By specifying the water content in the ion exchange resin, it is possible to shorten the reaction time and reuse the ion exchange resin catalyst. However, water is used because the raw materials used are siloxanes or silanes containing alkoxy groups or hydroxyl groups, which are then condensed. As a result, the resulting siloxanes contain a high proportion of remaining alkoxy groups and hydroxyl groups, making them more likely to be polymerized.

Patent Document 2 (JP 2011-219647 A) describes a method for producing silanol-containing organosilanes and organopolysiloxanes in which organoalkoxysilanes and water are continuously passed through a cylindrical container filled with a cation exchange resin. Continuous passage through the cylindrical container improves the reaction rate. However, when acrylic groups are present, as in this patent, the acrylic groups may be broken down into hydroxyl groups by moisture and heat. Furthermore, the hydroxyl groups may polymerize with each other, resulting in a high molecular weight.

Patent Document 3 (WO 2021/210333) describes polymerizing organopolysiloxanes using a cation exchange resin that is substantially free of water. This method is no problem for synthesizing siloxanes containing alkyl or alkenyl groups, but in the case of siloxanes containing acrylic groups, it is necessary to reduce the amount of water not only in the cation exchange resin but also in the siloxane itself, as, as mentioned above, moisture can easily cause decomposition of the acrylic groups and subsequent polymerization of the hydroxyl groups.

By combining acrylic and alkenyl group-containing siloxanes with organohydrogensiloxanes, platinum catalysts, and peroxides, an addition reaction and radical polymerization occur when heated, creating a tough elastomer.

Special Publication No. 2012-512272 JP 2011-219647 A International Publication No. 2021/210333

The equilibration reaction of low-molecular-weight acrylic group-containing organopolysiloxanes, low-molecular-weight alkylpolysiloxanes, and alkenyl group-containing organopolysiloxanes proceeds slowly when sulfuric acid or trifluoromethanesulfonic acid is used as a catalyst. At reaction times of 50 minutes or less, the polymerization of the alkylpolysiloxanes and alkenyl group-containing organopolysiloxanes proceeds rapidly, while the polymerization of the acrylic group-containing organopolysiloxanes does not proceed, often resulting in the low-molecular-weight compounds remaining. On the other hand, raising the temperature above 90°C to accelerate the reaction is undesirable, as it can cause decomposition and polymerization of the acrylic groups. If the acrylic groups are not sufficiently equilibrated, the resulting liquid will range from slightly cloudy to milky white, and when the alkenyl group- and acrylic group-containing organopolysiloxanes are cured, the coating will have both hard and soft regions, resulting in insufficient mechanical strength.

Solid acid catalysts are effective in shortening reaction times, but because acrylic-containing organopolysiloxanes have poor compatibility with alkylpolysiloxanes and alkenyl-containing organopolysiloxanes, even when the temperature is raised and the mixture is stirred, some of the acrylic-containing siloxanes settle to the bottom of the stirring layer, making it difficult to deliver a uniform liquid and resulting in differences in acrylic group concentration. For this reason, when a mixture of acrylic-containing siloxanes, alkylpolysiloxanes, and alkenyl-containing organopolysiloxanes is reacted by continuously passing it through a cylindrical vessel filled with a solid acid catalyst, the reaction tends to become pulsating, and the resulting compound is often cloudy. This is due to the coexistence of acrylic-rich siloxanes and acrylic-free alkylpolysiloxanes and alkenyl-containing organopolysiloxanes.

Furthermore, if the resulting alkenyl- and acrylic-group-containing organopolysiloxane contains more than 500 ppm of residual hydroxyl and alkoxy groups, it will be prone to moisture absorption, resulting in a high water concentration in the system. Water is also generated during the condensation reaction. In the case of acrylic-group-containing organopolysiloxane, the presence of water in the solid acid causes decomposition of the acrylic groups, converting them to hydroxyl groups. The hydroxyl groups then condense with each other or with alkoxy groups, resulting in a high molecular weight.

As a result of extensive research to achieve the above-mentioned objective, the inventors discovered that by equilibrating and polymerizing raw materials, such as an organopolysiloxane represented by the following formula (1) and a low-molecular-weight acrylic group-containing organopolysiloxane represented by the following formula (2), in the presence of a solid acid catalyst, with the water content and dissolved oxygen concentration in the reaction system within specific ranges, it is possible to produce an acrylic group- and alkenyl group-containing organopolysiloxane represented by formula (3) with well-dispersed acrylic groups, which led to the completion of the present invention.

Accordingly, the present invention provides the following method for producing organopolysiloxanes.
1. (A) The following formula (1)
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
a is 0≦a≦8, b is 0≦b≦100, c is 0≦c≦8, and d is 0≦d≦3. However, a and b cannot be 0 at the same time.
and a component represented by
(B) Formula (2) below
(In the formula, each R is independently ^an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms; ^R is an acrylic group-containing organic group represented by _CH2 = ^CR2COR3- ; R2 is a hydrogen atom or a methyl group; ^R3 is a divalent organic group represented by ^OR4 or ^R4 ; ^R4 is a divalent alkylene group or arylene group having 1 to 20 carbon atoms, which may have a branched or cyclic structure and may contain an epoxy group, an ester group, a urethane group, an ether group, or an isocyanate group; e and ^f are numbers satisfying 0 or 0≦e+f≦6; g is a number satisfying 0≦g<10; h is a number satisfying 0<h<20; i is a number satisfying 0≦i≦4; j is a number satisfying 0≦i≦4; and k is a number satisfying 0≦k≦2.)
and a component represented by
The method comprises a step of equilibrating and polymerizing in the presence of a solid acid catalyst in a state where the water content in the reaction system is 200 ppm or less and the dissolved oxygen concentration in the reaction system is ^10-3 to ¹⁰³ volume %.
The following formula (3)
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
It may have an aliphatic unsaturated bond. R ^A is an acrylic group-containing organic group represented by CH ₂ ═CR ² COR ³ —, R ² is a hydrogen atom or a methyl group, R ³ is a divalent organic group represented by OR ⁴ or R ⁴ , and R ⁴ is a divalent alkylene group, aryl group, or aralkyl group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and which may contain an epoxy group, ester group, urethane group, ether group, or isocyanate group.
m and o are 0 or a number in the range of 2≦m+o≦6, p is 10≦p<220, and q is 0<q<20.
r is 0≦r≦4, s is 0≦s≦4, and t is 0≦t≦2.
is expressed as
A method for producing an organopolysiloxane containing acrylic and alkenyl groups, which has a haze of 10% or less, hydroxyl and alkoxy groups of 5 mol% or less relative to all functional groups bonded to silicon atoms in the siloxane as detected by ^13C -NMR measurement, and a viscosity at 25°C measured by Ostwald method of 10 to 1,000 mm ² /s.
2. The method for producing organopolysiloxane according to 1, wherein the equilibration and polymerization step is carried out in the presence of 1 to 5,000 ppm of a polymerization inhibitor.
3. The method for producing organopolysiloxane according to 1 or 2, wherein component (B) is a copolymer of an alkylsiloxane and an alkylacrylsiloxane.
4. The method for producing organopolysiloxane according to any one of 1 to 3, wherein the equilibration and polymerization temperature is 30 to 90°C.
5. The method for producing organopolysiloxane according to any one of 1 to 4, wherein the solid acid catalyst is a cation exchange resin.
6. The method for producing organopolysiloxane according to any one of 1 to 4, wherein the solid acid catalyst is a mixture of a cation exchange resin and an anion exchange resin.
7. The method for producing an organopolysiloxane according to any one of 1 to 6, wherein the equilibration and polymerization step is a step of continuously passing component (A) and component (B) through a vessel filled with a solid acid catalyst to effect equilibration and polymerization.

The acrylic and alkenyl group-containing organopolysiloxane of the present invention can be produced in a short time, and because the acrylic groups are dispersed rather than unevenly distributed, it has excellent transparency. As a result, the reaction product obtained by polymerizing the acrylic and alkenyl group-containing organopolysiloxane retains sufficient strength and is able to form a uniform cured coating. Furthermore, because the amount of residual hydroxyl and alkoxy groups is low, the decomposition of acrylic groups and the generation of hydroxyl groups over time, which leads to the resulting high molecular weight due to condensation, do not occur, allowing for long-term storage.

FIG. 1 is a schematic diagram of an apparatus used in the examples.

The present invention will be described in detail below.
That is, the present invention comprises the step of equilibrating and polymerizing component (A) represented by formula (1) and component (B) represented by formula (2) in the presence of a solid acid catalyst, with the water content in the reaction system kept at 200 ppm or less and the dissolved oxygen concentration in the reaction system at ^10-3 to ¹⁰³ volume %. This production method produces an acrylic- and ^alkenyl -containing organopolysiloxane represented by formula (3), which has a haze of 10% or less, hydroxyl and alkoxy groups accounting for 5 mol% or less of all functional groups bonded to silicon atoms in the siloxane as detected by 13C-NMR analysis, and a viscosity at 25°C measured by Ostwald analysis of 10 to 1,000 ^mm2 /s.

[Component (A)]
The component (A) of the present invention is represented by the following formula (1):
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
a is 0≦a≦8, b is 0≦b≦100, c is 0≦c≦8, and d is 0≦d≦3. However, a and b cannot be 0 at the same time.
These are components represented by the formula (I) and can be used alone or in combination of two or more.

R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms, and examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, and dodecyl; alkenyl groups represented by -( _CH2 ) _n -CH= _CH2 (n is 0 or a positive number of 6 or less), such as vinyl, allyl, butenyl, propenyl, hexenyl, and octenyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, naphthyl, and tolyl; and aralkyl groups such as benzyl and phenethyl. Among these, from the viewpoints of water repellency, flowability, and cost, it is preferable that 80 mol% or more of the total number of Rs be methyl groups. R also includes cases where alkoxy groups or hydroxyl groups remain in trace amounts due to decomposition of functional groups or in the raw materials. Generally, when there are many remaining hydroxyl groups or alkoxy groups, the pH shifts to acidic or alkaline, or metal components are present, condensation between hydroxyl groups or between hydroxyl groups and alkoxy groups occurs over time, resulting in high molecular weight. If the viscosity becomes too high due to high molecular weight, handling becomes difficult and reactivity may decrease. The viscosity of component (A) is preferably 50 to 600 mPa·s, and more preferably 100 to 500 mPa·s. Setting the viscosity at or above the lower limit facilitates uniform application to the substrate. The above viscosity is measured at 25°C using a BM-type rotational viscometer. The rotor and rotation speed are appropriately selected depending on the viscosity. The total amount of hydroxyl groups and alkoxy groups remaining in component (A) is preferably 500 ppm (mass%) of the total amount of component (A), more preferably 100 ppm or less. The total amount of hydroxyl groups and alkoxy groups can be calculated by ¹ H-NMR (test conditions: 10%-CDCL3, 128 scans).

a is 0≦a≦8, and preferably 2≦a≦4. b is 0≦b≦100, and preferably 0≦b≦10. c is 0≦c≦8, and preferably 0≦c≦3. d is 0≦d≦3, and preferably 0≦d≦1. However, a and b cannot be 0 at the same time.

A specific example of the structure of the compound of formula (1) is a siloxane having the following structure:
{(CH ₃ ) ₃ SiO _1/2 } ₂
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₂
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₃
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₄
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₆
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₁₀
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₂
{(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 }
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } ₂
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ )φSiO _2/2 } ₃
The above φ represents a phenyl group.
{(CH ₃ ) ₂ SiO _2/2 } ₃
{(CH ₃ ) ₂ SiO _2/2 } ₄
{(CH ₃ ) ₂ SiO _2/2 } ₅
{(CH ₃ ) ₂ SiO _2/2 } ₆
{(CH ₃ ) ₂ SiO _2/2 } ₈
{(CH ₃ ) ₂ SiO _2/2 } ₃ {(CH=CH)(CH)SiO _2/2 }
{( _CH2 =CH)( _CH3 )SiO}
{(CH ₃ ) ₃ SiO _1/2 } ₃ {(CH ₃ )SiO _3/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₃ {(CH ₃ ) ₂ SiO _2/2 } {(CH ₃ )SiO _3/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₄ {(CH ₃ ) ₂ SiO _2/2 } ₅ {SiO _4/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₄ {(CH ₃ ) ₂ SiO _2/2 } ₅ {(CH ₃ )SiO _3/2
The component (A) can be obtained by a known method.

[(B) Component]
The component (B) is represented by the following formula (2):
(In the formula, each R is independently ^an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms; ^R is an acrylic group-containing organic group represented by _CH2 = ^CR2COR3- ; R2 is a hydrogen atom or a methyl group; ^R3 is a divalent organic group represented by ^OR4 or ^R4 ; ^R4 is a divalent alkylene group or arylene group having 1 to 20 carbon atoms, which may have a branched or cyclic structure and may contain an epoxy group, an ester group, a urethane group, an ether group, or an isocyanate group; e and ^f are numbers satisfying 0 or 0≦e+f≦6; g is a number satisfying 0≦g<10; h is a number satisfying 0<h<20; i is a number satisfying 0≦i≦4; j is a number satisfying 0≦i≦4; and k is a number satisfying 0≦k≦2.)
It is a low molecular weight intermediate compound containing an acrylic group and is synthesized by hydrolysis and condensation of various silanes. The component (B) can be used alone or in combination of two or more.

R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms. ^R is an acrylic group-containing organic group represented by CH ₂ ═CR ² COR ³ —. R ² is a hydrogen atom or a methyl group. R ³ is a divalent organic group represented by OR ⁴ or R ⁴ , where R ⁴ is a divalent alkylene group or arylene group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and may contain an epoxy group, ester group, urethane group, ether group, or isocyanate group. Examples of ^R4 include divalent hydrocarbon groups such as linear alkylene groups such as methylene, ethylene, propylene, butylene, hexamethylene, octamethylene, and decylene, branched alkylene groups such as methylethylene and methylpropylene, cyclic alkylene groups such as cyclohexylene, alkenylene groups such as propenylene, arylene groups such as phenylene, and aralkylene groups such as methylenephenylene and methylenephenylenemethylene. The divalent hydrocarbon group may be interposed with an ester group, a urethane group, an ether group, or an isocyanate group, and these groups may also be used in combination. Among these, a propylene group is preferred as ^R4 .

E and f are 0 or a number in the range 0≦e+f≦6, with 0≦e+f≦3 being preferred. g is 0≦g<10, with 0≦g<5 being preferred. h is 0<h<20, with 0<h<10 being preferred, with 0<h<5 being more preferred. i is 0≦i≦4, with 0≦i≦1 being preferred. j is 0≦j≦4, with 0≦j≦1 being preferred. k is 0≦k≦2, with 0≦k≦1 being preferred.

The kinematic viscosity of component (B) at 25°C measured with an Ostwald viscometer is preferably 0.1 to 100 ^mm /s, more preferably 0.2 to 50 ^mm /s, and even more preferably 0.5 to 30 ^mm /s. By keeping the viscosity within this range, the speed at which it flows through the solid acid increases.

Specific examples of acrylic group-containing silanes, which are raw materials for synthesizing component (B), include 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, and 3-acryloxypropylmethyldiethoxysilane. In addition to the above acrylic group-containing silanes, it is preferable to incorporate alkylalkoxysilanes such as dimethyldimethoxysilane. When acrylic group-containing alkoxysilanes react with water under acidic conditions, a hydrolysis reaction occurs, generating silanol groups. The resulting silanol groups then condense to synthesize intermediate compounds. The hydrolysis reaction also occurs under alkaline conditions, followed by a condensation reaction to synthesize intermediate compounds. Specific examples of chlorosilanes include 3-acryloxypropyltrichlorosilane and 3-acryloxypropylmethyldichlorosilane. When chlorosilanes are added dropwise to water, they react with hydrochloric acid to form silanols. These silanols then condense to synthesize intermediate compounds.

As component (B), by using not only an acrylic group-containing siloxane unit but also a copolymer of an acrylic group-containing siloxane and an alkylsiloxane, the acrylic group-containing organopolysiloxane can be dissolved without separation in the other raw materials, alkylpolysiloxane and alkenyl group-containing organopolysiloxane.Among these, a copolymer of an alkylsiloxane and an alkylacrylsiloxane is preferred, and the following structure can be given as an example of the specific structure of component (B).
{(CH ₃ ) ₃ SiO _1/2 } ₂ {CH ₃ R ^A SiO _2/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₂ {CH ₃ R ^A SiO _2/2 } {(CH ₃ ) ₂ SiO _2/2 } ₃
{(CH ₃ ) ₃ SiO _1/2 } ₂ {CH ₃ ^RA SiO _2/2 } ₃ {(CH ₃ ) ₂ SiO _2/2 } ₃
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₂ {(CH ₃ ) ₂ SiO _2/2 } {CH ₃ R ^A SiO _2/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₂ {(CH ₃ )φSiO _2/2 } ₃ {CH ₃ R ^A SiO _2/2 }
The above φ represents a phenyl group.
{CH ₃ R ^A SiO _2/2 } ₄
{CH ₃ R ^A SiO _2/2 } ₅
{(CH ₃ ) ₂ SiO _2/2 } {CH ₃ R ^A SiO _2/2 } ₂
{(CH ₃ ) ₂ SiO _2/2 } {CH ₃ R ^A SiO _2/2 } ₃
{(CH ₃ ) ₂ SiO _2/2 } ₃ {CH ₃ R ^A SiO _2/2 }
{(CH ₃ ) ₂ SiO _2/2 } ₄ {CH ₃ R ^A SiO _2/2 }
{(CH ₃ ) ₂ SiO _2/2 } ₃ {(CH ₂ =CH) (CH ₃ )SiO _2/2 } {CH ₃ R ^A SiO _2/2 }
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₃ {CH ₃ R ^A SiO _2/2 } {(CH ₃ )SiO _3/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₄ {(CH ₃ ) ₂ SiO _2/2 } ₅ {CH ₃ R ^A SiO _2/2 } {SiO _4/2 }
{(CH ₃ ) ₃ SiO _1/2 } ₄ {(CH ₃ ) ₂ SiO _2/2 } ₅ {CH ₃ R ^A SiO _2/2 } {(CH ₃ )SiO _3/2 } ₂
The above R ^A represents CH ₂ ═CR ² COR ³ —.

Among the above, raw materials consisting solely of acrylic group-containing organopolysiloxanes such as { _CH3RASiO2 ^/ ₂ } ₄ and { _CH3RASiO2 ^/ ₂ } ₅ are incompatible with other alkylpolysiloxanes or alkenyl group-containing organopolysiloxanes during the synthesis of acrylic group- and alkenyl group-containing siloxanes in the next step, and may partially separate and settle to the bottom of the container. For this reason, it is preferable to use copolymers of acrylic group-containing ^siloxanes and dialkylsiloxanes such as { _{( CH3} ) _{2SiO2 / 2} }{ _{CH3RASiO2/ 2 } 2} or {( _CH3 )2SiO2/2}{ ^CH3RASiO2 _/ 2} ₃ , because they are compatible with alkylpolysiloxanes and alkenyl group-containing organopolysiloxanes.

[Solid acid catalyst]
Solid acid catalysts are widely used to promote diesel cracking reactions and organic synthesis. Examples of solid acid catalysts include cation exchange resins, zeolites, silica alumina, alumina, titania, silica gel, alumina, or diatomaceous earth modified with sulfonic acid groups or phosphoric acid, mesoporous materials, heteropolyacids, sulfated zirconia, and sulfated nanographene. These can be used alone or in combination. Among these, cation exchange resins are preferred for the polymerization of siloxane compounds. Examples of cation exchange resins include styrene or styrene-divinylbenzene copolymers modified with sulfonic acid or carboxylic acid functional groups, and are available in gel or bead form.

Specific examples of cation exchange resins include DIAION SK104H, DIAION KS1BH, DIAION PK208LH, DIAION PK212LH, DIAION PK216LH, DIAION PK228LH, RCP145H, RCP160H, UBK08H (manufactured by Mitsubishi Chemical Corporation), Amberlyst 15DRY, Amberlyst 15JWET, Amberlyst 16WET, Amberlyst 33, Amberlyst 35WET, Amberlyst A21, Amberlyst SGC650, Amberlyst SSTC60, and Amberlyst SSTC60 H, Amberlyst SSTC80C (manufactured by Organo Corporation), C100, C100E, C120E, C100x10, C100x12, C100x16MBH, C145S, C150, C160 (manufactured by Purolite), etc.

In addition, cation exchange resins can sometimes cause strong acids to leach into the reaction solution, and the strong acid can cause the polymerization reaction to proceed too quickly. In such cases, using a mixture of cation exchange resin and anion exchange resin is preferable, as it neutralizes the leaching strong acid. A specific example of a mixture of cation exchange resin and anion exchange resin is a mixture of resin particles bonded with sulfonic acid and resin particles bonded with tertiary amine (MSPS2-1DRY, manufactured by Organo Corporation).

The amount of solid acid catalyst used is preferably 1 to 10,000 parts by mass per 100 parts by mass of silicone.

[Polymerization inhibitor]
As a means for suppressing radical polymerization of the acrylic group, it is preferable to carry out equilibration and polymerization in the presence of a polymerization inhibitor, and it is more preferable to use a polymerization inhibitor and a retarder in combination. Furthermore, a polymerization inhibitor may be added to suppress radical polymerization of the acrylic group during the equilibration and polymerization reaction and during distillation under reduced pressure at high temperatures. The polymerization inhibitors may be used alone or in combination of two or more.

Examples of polymerization inhibitors include dibutylhydroxytoluene, N,N'-diphenyl-p-phenylenediamine, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 2,2-diphenyl-1-picrylhydrazyl (DPPH), tert-butylhydroquinone, 1,4-benzoquinone, hydroquinone, 4-methoxyphenol, phenothiazine, tert-butylbenzoquinone, tert-butylxylenol, tert-butylphenol, tert-butylcresol, tert-butylpyrocatechol, and copper(II) dibutyldithiocarbamate. Among these, dibutylhydroxytoluene and N,N'-diphenyl-p-phenylenediamine are preferred.

The amount of polymerization inhibitor blended is preferably 1 to 5,000 ppm (by mass) relative to the total mass of the reaction liquid, more preferably 100 to 3,000 ppm, and even more preferably 200 to 2,000 ppm. By using an amount of polymerization inhibitor of 1 ppm or more, an increase in the viscosity of the product can be further suppressed.

[Moisture content]
When polymerizing an acrylic group-containing organopolysiloxane in the presence of a solid acid catalyst, attention must be paid to the amount of water contained in the solid acid catalyst and the siloxane composition corresponding to the reaction system. The amount of water in the reaction system is 200 ppm (by mass) or less, preferably 100 ppm or less, more preferably 50 ppm or less, and even more preferably 30 ppm or less. If the water content exceeds 200 ppm, the acrylic groups in the solid acid catalyst decompose and become hydroxyl groups. This reduces the amount of acrylic groups. Furthermore, the resulting hydroxyl groups react with each other by condensation, resulting in a high molecular weight. The lower limit of the water content is not particularly limited, and it may be 0 ppm.

An effective method for reducing moisture content is bubbling with dry nitrogen gas. Bubbling with dry nitrogen gas can reduce the moisture content in siloxane in a short period of time. Moisture content is determined using a Karl Fischer moisture meter, such as the MOISTAR-A18 (manufactured by HIRANUMA). The moisture content in this invention is determined by the volumetric method of the Karl Fischer method. A sample is placed in stirred methanol and KF reagent is added dropwise. The iodine in the KF reagent reacts with water, and the moisture content in the sample is determined from the amount of KF reagent consumed. In this invention, the measurement temperature is 25°C.

[Dissolved oxygen concentration]
It is known that the polymerization of acrylic groups is inhibited by the generation of peroxide radicals by oxygen. The dissolved oxygen concentration in the reaction system is ^10-3 to ¹⁰³ volume %. It is known that the polymerization of acrylic groups is inhibited by the generation of peroxide radicals by oxygen, which acts as an inhibitor. Since the steady-state concentration of radicals is thought to be ^10-7 volume % or less, radical polymerization can be inhibited by bubbling nitrogen gas containing 2% oxygen by mass and adjusting the dissolved oxygen concentration in the reaction system to ^10-3 to ¹⁰³ volume % as calculated from the bubbling amount. The dissolved oxygen concentration in the reaction system is preferably ^10-2 to ^102. The dissolved oxygen concentration is measured using the diaphragm galvanic electrode method. While there are no particular limitations on the equipment used for this measurement method, a portable dissolved oxygen meter, such as the LAQUA D-210D (manufactured by HORIBA), can be used. This oxygen meter determines the oxygen concentration using the diaphragm galvanic electrode method.

The advantages of solid acid catalysts are that they can be used repeatedly and can carry out reactions in a short time, reducing costs. The temperature when polymerizing siloxane raw materials in a solid acid catalyst is preferably 30 to 90°C, more preferably 40 to 90°C, and even more preferably 50 to 80°C. By carrying out the reaction at 30°C or higher, the reaction progresses quickly, and the reaction time for the siloxane composition to pass through the solid acid catalyst tower can be reduced to less than 60 minutes. On the other hand, by carrying out the reaction at 90°C or lower, the solid acid has sufficient heat resistance, further suppressing the decomposition and polymerization of acrylic groups.

[Organic solvent]
Because the siloxane raw material and product flow through the solid acid catalyst at a constant rate, a low viscosity is preferable, and the addition of an organic solvent can be effective in lowering viscosity. Examples of organic solvents that can be used include toluene, hexane, xylene, methyl ethyl ketone (also known as 2-butanone), acetone, ethanol, isopropyl alcohol, cyclohexanol, and ethyl acetate. The use of an organic solvent reduces the viscosity of the reaction system, enabling stable production; however, the organic solvent must be added in an amount of 30% by mass or less relative to the siloxane, resulting in a lower yield.

Equilibration and Polymerization Step
The equilibration and polymerization step is preferably a method in which the components (A) and (B) are continuously passed through a vessel filled with a solid acid catalyst. Specifically, a method in which a mixed solution in which the acrylic group-containing organopolysiloxane represented by formula (2) is uniformly dispersed in the organopolysiloxane represented by formula (1) is continuously passed through the solid acid catalyst is preferred. This allows the equilibration and polymerization reaction to proceed in a short period of time. The reaction time of the mixed solution is preferably 10 seconds to less than 60 minutes.

The resulting product is preferably purified by vacuum concentration or filtration. For example, vacuum concentration is performed by reducing the pressure to 0-100 mmHg using a vacuum pump or similar, and heating the surroundings of the container to 40-160°C using a jacket or oil bath with steam or a heat medium flowing in. Filtration is performed using filter paper or a filter plate to remove solids, salts, and impurities.

[Acrylic group- and alkenyl group-containing organopolysiloxane]
The resulting product is represented by the following formula (3):
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
It may have an aliphatic unsaturated bond. R ^A is an acrylic group-containing organic group represented by CH ₂ ═CR ² COR ³ —, R ² is a hydrogen atom or a methyl group, R ³ is a divalent organic group represented by OR ⁴ or R ⁴ , and R ⁴ is a divalent alkylene group, aryl group, or aralkyl group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and which may contain an epoxy group, ester group, urethane group, ether group, or isocyanate group.
m and o are 0 or a number in the range of 2≦m+o≦6, p is 10≦p<220, and q is 0<q<20.
r is 0≦r≦4, s is 0≦s≦4, and t is 0≦t≦2.
is expressed as
The organopolysiloxane contains acrylic and alkenyl groups and has a haze of 10% or less, a content of hydroxyl and alkoxy groups of 5 mol% or less of all functional groups bonded to silicon atoms of the siloxane as detected by ^13C -NMR measurement, and a viscosity at 25°C measured by Ostwald method of 10 to 1,000 mm ² /s.

In formula (3), each R is independently ^an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms, which may have an aliphatic unsaturated bond. ^RA is an acrylic group-containing organic group represented by _CH2 = ^CR2COR3- . ^R2 is a hydrogen atom. ^R3 is a divalent organic group represented by ^OR4 or ^R4 , and each ^R4 is independently a divalent alkylene group or arylene group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and which may contain an epoxy group, ester group, urethane group, ether group, or isocyanate group.

Examples of ^R4 include divalent hydrocarbon groups such as linear alkylene groups such as methylene, ethylene, propylene, butylene, hexamethylene, octamethylene, and decylene, branched alkylene groups such as methylethylene and methylpropylene, cyclic alkylene groups such as cyclohexylene, alkenylene groups such as propenylene, arylene groups such as phenylene, and aralkylene groups such as methylenephenylene and methylenephenylenemethylene. The divalent hydrocarbon group may be interposed with an ester group, a urethane group, an ether group, or an isocyanate group, and these groups may also be used in combination. Among these, a propylene group is preferred as ^R4 .

m and o are 0 or a number in the range 2≦m+o≦6, preferably 2≦m+o≦4. p is 10≦p<220, preferably 20≦p<180. q is 0<q<20, preferably 0<q<10, more preferably 0<q<5. r is 0≦r≦4, preferably 0≦r≦2. s is 0≦s≦4, preferably 0≦s≦2. t is 0≦t≦2, preferably 0≦t≦1.

If p is less than 10, the crosslink density of the cured product will be too high, making it brittle. If p is 220 or more, the kinematic viscosity of the product at 25°C will exceed 1,000 mm ² /s, and the siloxane flowing through the solid acid column filled with solid acid will tend to become turbulent, with the flow speed varying depending on the location, resulting in a difference in the time it takes to flow through the solid acid. Locations that take a long time may experience an increase in the viscosity of the siloxane, which is undesirable. A more preferred viscosity range for the product is 20 to 600 mm ² /s.

Specific examples of the acrylic and alkenyl group-containing organopolysiloxane include siloxanes having the following structure as the product structure:
{(CH ₂ = CH) (CH ₃ ) ₂ SiO _1/2 } ₂ {CH ₃ R ^A SiO ^2/2 } ^0.1 {(CH ³ ) ₂ SiO ^2/2 } ¹⁵⁰
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₂ {CH ³ R ^A SiO _2/2 } _1.5 {(CH ₃ ) ₂ SiO _2/2 } ₁₀₀
{(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 } ₄ {CH ₃ R ^A SiO _2/2 } ₅ {(CH ₃ ) ₂ SiO _2/2 } ₁₂₀ {(CH ₃ )SiO _3/2 } ₂
{(CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 } ₂ {CH ₃ R ^A SiO _2/2 } ₁₀ {(CH ₃ ) ₂ SiO2 _/2 } ₁₅₀
{(CH ₂ =CH)(CH ₃ ) ₂ SiO _1/2 } ₂ {CH ₃ R ^A SiO _2/2 } ₁ {(CH ₃ )φSiO _2/2 } ₃ {(CH ₃ ) ₂ SiO _2/2 } ₁₅₀
φ represents a phenyl group {(CH ₂ ═CH)(CH ₃ ) ₂ SiO _1/2 } _2.2 {CH ₃ R ^A SiO _2/2 } ₅ {(CH ₃ ) ₂ SiO _2/2 } ₁₀₀ {SiO _4/2 } _0.1

The product characteristics are as follows:
The haze is 10% or less, and can be 5% or less. The lower limit can be 0%. Haze is measured by dissolving approximately 30 mg of a sample in deuterated chloroform and placing it in a dedicated NMR tube. The number of measurements is 1,000. Of all functional groups bonded to silicon atoms in the siloxane detected in ¹³ C-NMR measurement, hydroxyl groups and alkoxy groups account for 5 mol% or less, preferably 3 mol% or less. The viscosity at 25°C measured by Ostwald spectroscopy is 10 to 1,000 mm ² /s, preferably 50 to 600 mm ² /s.

The organopolysiloxane of the present invention can be mixed with organohydrogensiloxane, a platinum catalyst, and peroxide, and then molded under heat to produce a silicone rubber with excellent strength and elongation.

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "%" in the composition means "% by mass." All kinematic viscosities are values ( ^mm2 /s) measured at 25°C using an Ostwald viscometer. Haze was measured by dissolving approximately 30 mg of a sample in deuterated chloroform and placing it in a dedicated NMR tube. The cumulative number of measurements was 1,000.

[Example 1]
18.6 g of 1,3-divinyltetramethyldisiloxane (A-1) and 1,080.4 g of octamethylcyclotetrasiloxane (A-2) as component (A), 64 g of dimethylsiloxane and methylacryloxypropylsiloxane copolymer (4) as component (B), 0.53 g of dibutylhydroxytoluene (7) as a polymerization inhibitor, and 0.01 g of N,N'-diphenyl-p-phenylenediamine (8) were placed in a 3 L Erlenmeyer flask. A PTFE stirrer was placed in the flask, and the mixture was stirred with a magnetic stirrer. 2% oxygen-containing nitrogen gas was bubbled into the Erlenmeyer flask at a flow rate of 0.05 L/min for 10 minutes. At this stage, the water content in the reaction system was 12 ppm, and the dissolved oxygen concentration was 2.8% by volume. This will be further explained using the apparatus shown in Figure 1. The above silicone composition in Erlenmeyer flask 1 was pumped up through tube 3 using diaphragm pump 2. The silicone composition was sent to a SUS pipe 4 connected to a tube 3. The area around the SUS pipe 4 was heated to 60°C by a ribbon heater 5.

The resulting silicone composition was sent to solid acid tower 6 (cylindrical, 22 mm diameter, 240 mm height), where it flowed through a solid acid catalyst (Amberlyst 15DRY, manufactured by Organo Corporation, an ion exchange resin with a styrene-based microporous base and sulfonic acid functional groups) packed into solid acid tower 6, and the reaction product was recovered. Solid acid tower 6 was covered with ribbon heater 5 and heated to 60°C.

The flow rate was 2 g/min, and the time spent in the solid acid (reaction time) was 50 minutes. The recovered reaction product was neutralized with Kyoward 500SH for 1 hour and then filtered using a filter plate. The reaction rate calculated from the peak of the remaining raw material in GPC (gel permeation chromatography) using toluene as the developing solvent (hereinafter sometimes referred to as toluene GPC; the measurement method is the same) was 93%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were: kinematic viscosity 418 ^mm /s, volatile content 0.2% (tested at 105°C for 3 hours), vinyl value 0.020 mol/100 g, structure calculated from ^H -NMR: M ^Vi ₂ D ₁₄₉ D ^A ₂ , proportion of hydroxyl and alkoxy groups to ^all functional groups bonded to silicon atoms calculated from C-NMR: 2.1 mol%, and haze: 2%.

[Example 2]
18.6 g of 1,3-divinyltetramethyldisiloxane (1) and 888 g of octamethylcyclotetrasiloxane (2) as component (A), 394 g of dimethylsiloxane and methylacryloxypropylsiloxane copolymer (5) as component (B), 0.53 g of dibutylhydroxytoluene (7) as a polymerization inhibitor, and 0.01 g of N,N'-diphenyl-p-phenylenediamine (8) were placed in a 3 L Erlenmeyer flask. A PTFE stirrer was placed in the flask and the mixture was stirred with a magnetic stirrer. Nitrogen gas containing 2% oxygen was bubbled into the Erlenmeyer flask at a flow rate of 0.05 L/min for 10 minutes. The water content in the reaction system at this stage was 14 ppm, and the dissolved oxygen concentration was 2.8% by volume.
The above-mentioned composition was reacted in the same manner as in Example 1. The reaction rate of the reactant was 90%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing siloxane were a kinematic viscosity of 580 ^mm /s, a volatile content of 0.4% (105°C, ³ hours), a vinyl value of 0.019 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₁₆₀ D ^A ₁₀ , the proportion of hydroxyl and alkoxy groups in all functional groups bonded to silicon atoms calculated from C-NMR of 2.1 mol%, and a haze of 2%.

[Example 3]
18.6 g of 1,3-divinyltetramethyldisiloxane (1) and 1,108.5 g of octamethylcyclotetrasiloxane (2) as component (A), 3.2 g of dimethylsiloxane and methylacryloxypropylsiloxane copolymer (4) as component (B), 0.53 g of dibutylhydroxytoluene (7) as a polymerization inhibitor, and 0.01 g of N,N'-diphenyl-p-phenylenediamine (8) were placed in a 3 L Erlenmeyer flask. A PTFE stirrer was placed in the flask and the mixture was stirred with a magnetic stirrer. Nitrogen gas containing 2% oxygen was bubbled into the Erlenmeyer flask at a flow rate of 0.05 L/min. The water content in the reaction system at this stage was 10 ppm, and the dissolved oxygen concentration was 2.8% by volume.
The above-mentioned composition was reacted in the same manner as in Example 1. The reaction rate was 94%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were a kinematic viscosity of 395 ^mm /s, a volatile content of 0.2% (tested at 105°C for 3 hours), a vinyl value of 0.020 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₁₅₁ D ^A _0.1 , the proportion of hydroxyl and alkoxy groups in ^all functional groups bonded to silicon atoms calculated from C-NMR of 2.1 mol%, and a haze of 2%.

[Example 4]
Synthesis was carried out using the same raw material composition and conditions as in Example 1, except that the solid acid catalyst was changed to Amberlyst MSPS2-1, a mixture of cation exchange resin and anion exchange resin. The composition used in the reaction had a moisture content of 12 ppm and a dissolved oxygen concentration of 2.8% by volume. The reaction rate was 92%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing siloxane were a kinematic viscosity of 386 ^mm /s, a volatile content of 0.4% (tested at 105°C for 3 hours), a vinyl value of 0.019 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₁₄₅ D ^A ₂ , the proportion of hydroxyl and alkoxy groups in ^all functional groups bonded to silicon atoms calculated from C-NMR of 0.4 mol%, and a haze of 0.7%.

[Example 5]
The same procedure as in Example 1 was used to prepare the reaction mixture, except that 18.6 g of 1,3-divinyltetramethyldisiloxane (1) and 1,110 g of octamethylcyclotetrasiloxane (2) were used as component (A), and 34.4 g of tetramethyltetraacryloxypropylcyclotetrasiloxane (6) was used as component (B). Nitrogen gas containing 2% oxygen was bubbled into the Erlenmeyer flask at a flow rate of 0.05 L/min. The water content in the reaction system at this state was 11 ppm, and the dissolved oxygen concentration was 2.8% by volume. Synthesis was carried out in the same manner as in Example 1, and the recovered reaction product was neutralized with Kyoward 500SH for 1 hour and then filtered using a filter plate. The conversion calculated from the residual raw material peak in toluene GPC was 90%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were a kinematic viscosity of 497 ^mm /s, a volatile content of 0.3% (tested at 105°C for 3 hours), a vinyl value of 0.018 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₁₆₃ D ^A _1.3 , the proportion of ^hydroxyl and alkoxy groups in all functional groups bonded to silicon atoms calculated from C-NMR of 2.9 mol%, and a haze of 9.8%.

[Example 6]
18.6 g of 1,3-divinyltetramethyldisiloxane (1) and 1,080.4 g of octamethyltetrasiloxane (2) as component (A), and 64 g of dimethylsiloxane and methylacryloxypropylsiloxane copolymer (4) as component (B) were placed in a 3 L Erlenmeyer flask. No polymerization inhibitor was added. A PTFE stirrer was placed in the flask and the mixture was stirred with a magnetic stirrer. Nitrogen gas containing 2% oxygen was bubbled into the Erlenmeyer flask at a flow rate of 0.05 L/min. The water content in the reaction system at this stage was 12 ppm, and the dissolved oxygen concentration was 2.8% by volume.
The synthesis was carried out in the same manner as in Example 1, and the recovered reaction product was neutralized with Kyoward 500SH for 1 hour and then filtered through a filter plate. The reaction rate was 92%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were: kinematic viscosity 590 ^mm /s, volatile content 0.2% (105°C, ³ hours), vinyl value 0.019 mol/100 g, structure calculated from ^H -NMR: M ^Vi ₂ D ₁₇₇ D ^A _1.8 , ratio of hydroxyl and alkoxy groups to all functional groups bonded to silicon atoms calculated from C-NMR: 2.9 mol%, and haze: 8.9%.

[Example 7]
A mixture of 594.1 g of the raw silicone composition of Example 1 and 405.9 g of the raw silicone composition of Comparative Example 3 had a water content of 150 ppm and a dissolved oxygen concentration of 2.8% by volume.
Synthesis, filtration, and vacuum concentration were carried out in the same manner as in Example 1, and the resulting acrylic and alkenyl group-containing organopolysiloxane had a reaction rate of 91%, and its physical properties were a kinematic viscosity of 589 ^mm2 /s, a volatile content of 0.2% (105°C, 3 hours), a vinyl value of 0.019 _mol / ₁₀₀ g, a structure calculated from ^1H - ^NMR of ^{MVi2D173DA1.9} , the proportion of ^{hydroxyl groups and alkoxy groups among all functional groups bonded to silicon atoms calculated from 13C} _- NMR of 2.6 mol%, and a haze of 6.8%.

[Example 8]
The same formulation as in Example 1 was used, except that 18.6 g of 1,3-divinyltetramethyldisiloxane (1), 1080.4 g of octamethylcyclotetrasiloxane (2), and 17.2 g of tetramethyltetravinylcyclotetrasiloxane (3) were used as component (A). The water content of the silicone composition was 13 ppm, and the dissolved oxygen concentration was 2.8% by volume. Synthesis was carried out using the same procedure as in Example 1, and after neutralization, filtration and vacuum concentration were carried out using the same methods as in Experimental Example 1. The reaction rate was 92%.
The physical properties of the resulting acrylic and alkenyl group-containing organopolysiloxane were a kinematic viscosity of 590 ^mm /s, a volatile content of 0.2% (105°C, 3 hours), a vinyl value of 0.019 mol/ _{100 g} , a structure calculated from ^1H - ^NMR of ^{MVi2D147DVi2DA2} , the proportion of ^hydroxyl groups and alkoxy groups among all functional groups bonded to silicon atoms calculated from ^13C -NMR of 2.2 _mol %, _and a haze of 2.1%.

[Comparative Example 1]
18.6 g of 1,3-divinyltetramethyldisiloxane (1) and 1,080.4 g of octamethylcyclotetrasiloxane (2) as component (A), 64 g of a dimethylsiloxane and methylacryloxypropylsiloxane copolymer (4) as component (B), 0.53 g of dibutylhydroxytoluene (7) as a polymerization inhibitor, and 0.01 g of N,N'-diphenyl-p-phenylenediamine (8) were placed in a 2 L separable flask and stirred with a glass stirring rod.
The bubbling of the 2% oxygen-containing nitrogen gas was stopped, and 15 g of trifluoromethanesulfonic acid was added to the above composition under a sealed condition, and the reaction was allowed to proceed at 60°C. 50 minutes after heating to 60°C, the reaction rate (toluene GPC) was 78%. A portion of the mixture was sampled and neutralized for 1 hour with 6 times the amount of Kyoward 500SH, followed by filtration. The resulting filtrate was distilled under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing siloxane were a kinematic viscosity of 308 ^mm2 /s, a water content of 11 ppm, a dissolved oxygen concentration of 2.9%, a hydroxyl to alkoxy group ratio of 8.9 mol%, and a haze of 18%.

The reaction was checked every hour, and after 360 minutes, the reaction rate exceeded 90% and reached 91%. It was not possible to complete the reaction within 60 minutes. Kyoward 500SH was added in a six-fold amount, neutralized for one hour, and then filtered. The resulting filtrate was distilled under reduced pressure at 150°C and 10 mmHg for three hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were: kinematic viscosity ₃₈₂ ^mm2 /s, volatile content 0.8% (tested at 105°C for three hours), water content 11 ^ppm , dissolved oxygen concentration _2.9 %, vinyl value 0.020 _mol /100g, structure calculated from ^1H -NMR: ^{MVi2D149DA2.2} , ratio of hydroxyl groups and alkoxy groups to all functional groups bonded to silicon atoms calculated from ^13C -NMR: 4.1 mol%, haze: 2.5%.

[Comparative Example 2]
The bubbling of 2% oxygen-containing dry nitrogen gas at a flow rate of 0.05 L/min was replaced with bubbling of dry nitrogen gas at 0.05 L/min, and the other steps were carried out in the same manner as in Example 1. The water content in the reaction system under this condition was 9 ppm, and the dissolved oxygen concentration was 0% by volume. The recovered reaction product was neutralized with Kyoward 500SH for 1 hour and then filtered using a filter plate. The reaction rate calculated from the peak of the remaining raw material in toluene GPC was 91%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were a kinematic viscosity of 1,010 ^mm /s, a volatile content of 0.2% (tested at 105°C for 3 hours), a vinyl value of 0.017 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₂₂₁ D ^A _1.4 , the proportion of hydroxyl and alkoxy groups in ^all functional groups bonded to silicon atoms calculated from C-NMR of 2.3 mol%, and a haze of 2.8%.

[Comparative Example 3]
3 g of distilled water was added and stirred into the same composition as in Example 1. In this test, bubbling of 2% oxygen-containing dry nitrogen gas or dry nitrogen gas was not performed.
After stirring for 1 hour, the water content in the reaction system was 352 ppm, and the dissolved oxygen concentration was 23% by volume.
The synthesis was carried out in the same manner as in Example 1, except that the addition of water and the supply of dry gas were not performed. The recovered reaction product was neutralized with Kyoward 500SH for 1 hour and then filtered through a filter plate. The reaction rate calculated from the peak of the remaining raw material in toluene GPC was 85%.
The filtrate was evaporated under reduced pressure at 150°C and 10 mmHg for 3 hours. The physical properties of the resulting acrylic- and alkenyl-containing organopolysiloxane were a kinematic viscosity of 1,205 ^mm /s, a volatile content of 0.2% (tested at 105°C for 3 hours), a vinyl value of 0.015 mol/100 g, a structure calculated from ^H -NMR of M ^Vi ₂ D ₂₄₇ D ^A _1.0 , the proportion of hydroxyl and alkoxy groups in ^all functional groups bonded to silicon atoms calculated from C-NMR of 5.8 mol%, and a haze of 11%.

[Component (A)]
{(CH ₂ ═CH)(CH ₃ ) ₂ SiO _1/2 } ₂ : 1,3-divinyltetramethyldisiloxane (1)
{( _CH3 ) _{2SiO2 /2} } ₄ : Octamethylcyclotetrasiloxane (2)
{(CH ₂ ═CH)(CH ₃ )SiO _2/2 } ₄ : tetramethyltetravinylcyclotetrasiloxane (3)
[(B) Component]
{(CH ₃ ) ₂ SiO _2/2 } ₂ {CH ₃ R ^A SiO _2/2 }
: Dimethylsiloxane and methylacryloxypropylsiloxane copolymer (4)
{(CH ₃ ) ₂ SiO _2/2 } ₃ {CH ₃ R ^A SiO _2/2 }
: Dimethylsiloxane and methylacryloxypropylsiloxane copolymer (5)
{CH ₃ R ^A SiO _2/2 } ₄ : tetramethyltetraacryloxypropylcyclotetrasiloxane (6)
[Polymerization inhibitor]
Dibutylhydroxytoluene (7)
N,N'-diphenyl-p-phenylenediamine (8)

^MVi : ( _CH2 =CH)( _CH3 ) _{2SiO1 /2}
D: ( _CH3 ) _{2SiO2 /2}
^DVi : ( _CH2 =CH)( _CH3 )SiO2 _/2
D ^A :CH ₃ R ^A SiO _2/2
(R ^A is CH ₂ =CHCOO(CH ₂ ) ₃ -

[Moisture content]
The moisture content was determined using MOISTAR-A18 (manufactured by HIRANUMA).
[Dissolved oxygen concentration]
Measurements were made using a portable dissolved oxygen meter, LAQUA D-210D (manufactured by HORIBA).

1 Erlenmeyer flask 2 Diaphragm pump 3 Tube 4 SUS piping 5 Ribbon heater 6 Solid acid catalyst

Claims (7)

(A) Formula (1) below
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
a is 0≦a≦8, b is 0≦b≦100, c is 0≦c≦8, and d is 0≦d≦3. However, a and b cannot be 0 at the same time.
and a component represented by
(B) Formula (2) below
(In the formula, each R is independently ^an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms; ^R is an acrylic group-containing organic group represented by _CH2 = ^CR2COR3- ; R2 is a hydrogen atom or a methyl group; ^R3 is a divalent organic group represented by ^OR4 or ^R4 ; ^R4 is a divalent alkylene group or arylene group having 1 to 20 carbon atoms, which may have a branched or cyclic structure and may contain an epoxy group, an ester group, a urethane group, an ether group, or an isocyanate group; e and ^f are numbers satisfying 0 or 0≦e+f≦6; g is a number satisfying 0≦g<10; h is a number satisfying 0<h<20; i is a number satisfying 0≦i≦4; j is a number satisfying 0≦i≦4; and k is a number satisfying 0≦k≦2.)
and a component represented by
The ^method comprises a step of equilibrating and polymerizing in the presence of a solid acid catalyst which is an ion exchange resin having sulfonic acid groups attached as functional groups , in a state in which the water content in the reaction system is 200 ppm or less and the dissolved oxygen concentration in the reaction system is ^10-3 to 103 volume %.
The following formula (3)
(wherein R are each independently an unsubstituted or substituted hydrocarbon group having 1 to 12 carbon atoms;
It may have an aliphatic unsaturated bond. R ^A is an acrylic group-containing organic group represented by CH ₂ ═CR ² COR ³ —, R ² is a hydrogen atom or a methyl group, R ³ is a divalent organic group represented by OR ⁴ or R ⁴ , and R ⁴ is a divalent alkylene group, aryl group, or aralkyl group having 1 to 20 carbon atoms, which may have a branched or cyclic structure, and which may contain an epoxy group, ester group, urethane group, ether group, or isocyanate group.
m and o are 0 or a number in the range of 2≦m+o≦6, p is 10≦p<220, and q is 0<q<20.
r is 0≦r≦4, s is 0≦s≦4, and t is 0≦t≦2.
is expressed as
A method for producing an organopolysiloxane containing acrylic and alkenyl groups, which has a haze of 10% or less, hydroxyl and alkoxy groups of 5 mol% or less relative to all functional groups bonded to silicon atoms in the siloxane as detected by ^13C -NMR measurement, and a viscosity at 25°C measured by Ostwald method of 10 to 1,000 mm ² /s. The method for producing organopolysiloxane according to claim 1, wherein the equilibration and polymerization step is carried out in the presence of 1 to 5,000 ppm of a polymerization inhibitor. The method for producing organopolysiloxane according to claim 1, wherein component (B) is a copolymer of alkylsiloxane and alkylacrylsiloxane. The method for producing organopolysiloxane according to claim 1, wherein the equilibration and polymerization temperature is 30 to 90°C. 2. The method for producing organopolysiloxane according to claim 1, wherein the solid acid catalyst is a cation exchange resin having sulfonic acid groups attached as functional groups . 2. The method for producing organopolysiloxane according to claim 1, wherein the solid acid catalyst is a mixture of cation exchange resin particles having sulfonic acid bonded thereto and anion exchange resin particles having tertiary amine bonded thereto. The method for producing an organopolysiloxane according to any one of claims 1 to 6 , wherein the equilibration and polymerization step comprises continuously passing component (A) and component (B) through a vessel filled with a solid acid catalyst to effect equilibration and polymerization.