JP4367632B2 - Silphenylene compound having photopolymerization initiating group and method for producing the same - Google Patents

Description

  The present invention relates to a silphenylene compound having a radical polymerization initiating group and a method for producing the same, and more particularly, a resin having a (meth) acryl functional group, in particular, a photopolymerization initiator of (meth) acryl-modified silicone resin and epoxy acrylate. The present invention relates to a silphenylene compound having a novel photopolymerization initiating group having high compatibility with a resin and in which a photopolymerization initiator does not separate and precipitate from a resin component even at low temperatures, and a method for producing the same.

  Conventionally, photopolymerization initiators have been properly used depending on the type of resin to be mixed and the application, but in practice, the optimum initiator may be selected by examining among various commercially available photoinitiators. Many. Therefore, inconveniences such as poor compatibility with the resin to be mixed may occur.

  Thus, a case has been reported in which a photoinitiator that can be chemically modified is reacted with various compounds according to the purpose to synthesize a new photoinitiator. 4- (2-Hydroxyethoxy) phenyl-2-hydroxy-2-propylketone (Irgacure 2959, trade name of Ciba Specialty Chemicals), which has the advantage of low volatility and low odor, can be chemically modified This compound is often used as a polymerization initiator for (meth) acrylic groups. For example, it has the disadvantage of being deposited at low temperatures after being dissolved in a silicone resin, resulting in the storage stability in winter. There is a problem. Moreover, since it is solid at normal temperature, there also exists a problem that it is hard to melt | dissolve in resin.

  The present invention has been made in view of the above circumstances, and has good compatibility with (meth) acryl-modified silicone resin and epoxy acrylate, and is liquid at room temperature without precipitation of a photoinitiator from the resin component at low temperature, It is an object of the present invention to provide a novel compound having a silphenylene skeleton useful as a photoinitiator and a method for producing the same.

  As a result of intensive studies to achieve the above object, the present inventors have found that a compound having a photopolymerization initiation group and a hydroxy group represented by the following general formula (2) and the following general formula (3-1) or ( 3-2) a novel silphenylene compound having a photopolymerization initiating group represented by the following general formula (1-1) or (1-2) obtained by reacting with a silphenylene compound represented by It is liquid at normal temperature, has good compatibility with (meth) acryl-modified silicone resins and epoxy acrylates, and has a useful radical polymerization initiating ability for (meth) acrylic groups without precipitation of photoinitiators from the resin even at low temperatures. As a result, the present invention has been completed.

（式中、Ｒ¹及びＲ²は炭素数１〜１０の１価の有機基を示し、ｎは１〜３の整数を示す。）

(Wherein, R ¹ and R ² represents a monovalent organic group having 1 to 10 carbon atoms, n represents an integer of 1-3.)

（式中、Ｒ¹は炭素数１〜１０の１価の有機基を示す。）

(In the formula, R ¹ represents a monovalent organic group having 1 to 10 carbon atoms.)

（式中、Ｒ²は炭素数１〜１０の１価の有機基を示す。）

(In the formula, R ² represents a monovalent organic group having 1 to 10 carbon atoms.)

Accordingly, the present invention provides the following silphenylene compounds and methods for producing the same.
[1] A silphenylene compound having a photopolymerization initiating group represented by the general formula (1-1) or (1-2).
[2] A compound having a photopolymerization initiating group and a hydroxy group represented by the general formula (2) is reacted with a silphenylene compound represented by the general formula (3-1) or (3-2). [1] The process for producing a silphenylene compound having a photopolymerization initiating group as described in [1].

  The photopolymerization initiating group-containing silphenylene compound of the present invention is liquid at normal temperature and has good compatibility with (meth) acryl-modified silicone resins and epoxy acrylates. ) Useful as a photopolymerization initiator for acrylic-modified resins.

  The novel photopolymerization initiating group-containing silphenylene compound of the present invention is represented by the following general formulas (1-1) and (1-2), and is important for generating radicals at both ends of the silphenylene skeleton. It contains a photopolymerization initiating group that plays an important role.

R ¹ and R ² in the formulas (1-1) and (1-2) are monovalent organic groups having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and are preferably saturated or unsaturated hydrocarbon groups. For example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, alkyl group such as heptyl group, alkenyl group such as vinyl group, allyl group, phenyl group, tolyl group, xylyl group, An aryl group such as a naphthyl group, an aralkyl group such as a benzyl group and a phenethyl group, an unsubstituted or halogen-substituted monovalent hydrocarbon group such as a chloromethyl group, a 3-chloropropyl group, and a 3,3,3-trifluoropropyl group And may include an ether structure or an ester structure. N is an integer of 1 to 3, and n = 1 is particularly preferable.

  The silphenylene compound having a photopolymerization initiating group represented by the general formulas (1-1) and (1-2) is represented by the following general formula (2).

（式中、Ｒ¹は炭素数１〜１０の１価の有機基を示す。）
で表される光重合開始基及びヒドロキシ基を有する化合物と、下記一般式（３−１）あるいは（３−２）

(In the formula, R ¹ represents a monovalent organic group having 1 to 10 carbon atoms.)
A compound having a photopolymerization initiating group and a hydroxy group represented by the following general formula (3-1) or (3-2):

（式中、Ｒ²は炭素数１〜１０の１価の有機基を示す。）
で表されるシルフェニレン化合物とを反応させることにより製造することができる。

(In the formula, R ² represents a monovalent organic group having 1 to 10 carbon atoms.)
It can manufacture by making the silphenylene compound represented by these react.

  Here, the compound having a polymerization initiating group and a hydroxy group represented by the general formula (2) contains at least one polymerization initiating group at the molecular end and also contains a hydroxy group (preferably a primary hydroxyl group and only one. Including —OH group of carboxylic acid or —OH group bonded to α-position carbon of carbonyl group).

R ¹ in formula (2) is a monovalent organic group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and is preferably a saturated or unsaturated hydrocarbon group, such as a methyl group, an ethyl group, Alkyl groups such as propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group and heptyl group, alkenyl groups such as vinyl group and allyl group, aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, benzyl group And unsubstituted or substituted monovalent hydrocarbon groups such as an aralkyl group such as a phenethyl group, a chloromethyl group, a 3-chloropropyl group, and a 3,3,3-trifluoropropyl group. Among these, an alkyl group such as a methyl group is preferable.

The silphenylene compound represented by the general formula (3-1) or (3-2) has a silyl chloride structure at both molecular ends.
R ² in formulas (3-1) and (3-2) is a monovalent organic group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, preferably a saturated or unsaturated hydrocarbon group, For example, alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, alkenyl group such as vinyl group, allyl group, phenyl group, tolyl group, xylyl group, naphthyl Aryl groups such as benzyl groups, aralkyl groups such as benzyl groups and phenethyl groups, and unsubstituted or substituted monovalent hydrocarbon groups such as chloromethyl groups, 3-chloropropyl groups and 3,3,3-trifluoropropyl groups. In addition, an ether structure or an ester structure may be included. Among these, a methyl group is preferable.

  The reaction ratio of the compound represented by the above formula (2) and the silphenylene compound represented by the above formula (3-1) or (3-2) is represented by the formula (3-1) or (3-2). The reaction is preferably carried out using 1.0 to 2.4 mol, particularly 1.8 to 2.2 mol of the compound of formula (2) per mol of the compound. If the amount of the compound of formula (2) is too small, a silphenylene compound having no photopolymerization initiating group may be contained, and if it is too large, it may take time to remove unreacted substances.

  This reaction is usually carried out in an organic solvent, and examples of such an organic solvent include tetrahydrofuran (THF), toluene, acetone and the like. This reaction is a de-HCl reaction, and it is preferable to trap HCl as an ammonium salt with an amine. As the amine, a known amine can be used, and examples thereof include triethylamine. The usage-amount of an amine is 2.0-2.4 mol normally with respect to 1 mol of said silphenylene compounds (3-1) or (3-2).

  This reaction is usually performed in the dark, at room temperature (eg, 0 to 45 ° C., preferably 5 to 40 ° C.) for 30 minutes to 4 hours, preferably 1 to 2 hours.

  In this way, a silphenylene compound having a novel photopolymerization initiating group represented by the general formula (1) is obtained. Since the photopolymerization initiating group-containing silphenylene compound has a photopolymerization initiating group, a radical can be generated by light, and a compound having a (meth) acryl group can be polymerized.

  EXAMPLES Hereinafter, although an Example and a reference example are shown and this invention is demonstrated more concretely, this invention is not limited to the following Example. In the formulas in the following examples, Me represents a methyl group.

[Example 1]
0.20 mol of 1,4-bis (dimethylchlorosilyl) benzene was dissolved in 250 ml of THF and stirred (solution 1), and Irgacure 2959 (Ciba Specialty Chemicals) A solution obtained by stirring and mixing 44 mol in 150 ml of THF (solution 2) was added to solution 1 at room temperature. The reaction solution became cloudy due to precipitation of (C ₂ H ₅ ) ₃ NH ⁺ Cl ⁻ , and the solution temperature rose from 20 ° C. to 40 ° C. After stirring in a room temperature atmosphere for 2 hours, the ammonium salt was removed by suction filtration, and the filtrate was heated under reduced pressure (50 ° C., 1 mmHg) with a rotary evaporator until no fraction was produced. ) Was obtained.

Next, GPC, IR, ¹ H-NMR, and ²⁹ Si-NMR of the obtained reaction product were measured. The results are shown in FIGS. GPC (FIG. 1) showed one peak, and ²⁹ Si-NMR (FIG. 4) also showed a single peak at 9.9 ppm. IR (NEAT) (FIG. 2) showed a peak 1664 cm ⁻¹ (carbonyl C═O stretching) derived from Irgacure 2959 and a peak 1137 cm ⁻¹ (Si—C ₆ H ₄ ) derived from silphenylene.

[Reference Example 1]
1.5 parts by mass of the silphenylene compound having a photopolymerization initiating group synthesized in Example 1 was uniformly mixed with 100 parts by mass of both-end acrylic modified silicone oil (weight average molecular weight: about 4,000), and photocurability was obtained. A silicone resin composition (A) was obtained.

[Comparative Reference Example 1]
As a comparison, 3 parts by weight of a photoinitiator (Irgacure 2959) was uniformly mixed with 100 parts by weight of both terminal acrylic-modified silicone oil (weight average molecular weight: about 4,000) to obtain a photocurable silicone resin composition (B). Got.

These photocurable silicone resin compositions (10 cm × 10 cm, thickness 1 mm) were exposed (400 mJ / cm ² ) with a metal halide lamp and cured. The physical properties of the cured product are as shown in Table 1, and no difference was observed in photocurability. Moreover, when it preserve | saved for 6 months at 0 degreeC, the change of the external appearance was not seen by (A), but (B) confirmed the white precipitate (Irgacure 2959).

＊引張強さ及び伸びはオートグラフを用いて測定した（引張速度：５００ｍｍ／ｍｉｎ）。

* Tensile strength and elongation were measured using an autograph (tensile speed: 500 mm / min).

It is a GPC measurement result of the reaction product obtained in the Example of this invention. It is IR measurement result of the reaction product obtained in the Example of this invention. It is a < ¹ > H-NMR measurement result of the reaction product obtained in the Example of this invention. It is a ²⁹ Si-NMR measurement result of the reaction product obtained in the Example of this invention.

Claims (2)

A silphenylene compound having a photopolymerization initiating group represented by the following general formula (1-1) or (1-2).

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms , an alkenyl group, an aryl group, an aralkyl group unsubstituted or a halogen-substituted monovalent hydrocarbon group, and n represents an integer of 1 to 3. .) The following general formula (2)

(Wherein R ¹ represents an unsubstituted or halogen-substituted monovalent hydrocarbon group of an alkyl group, alkenyl group, aryl group or aralkyl group having 1 to 10 carbon atoms.)
A compound having a photopolymerization initiating group and a hydroxy group represented by the following general formula (3-1) or (3-2):

(In the formula, R ² represents an unsubstituted or halogen-substituted monovalent hydrocarbon group of an alkyl group, alkenyl group, aryl group or aralkyl group having 1 to 10 carbon atoms.)
The method for producing a silphenylene compound having a photopolymerization initiating group according to claim 1, wherein the compound is reacted with a silphenylene compound represented by the formula:

Images