JP2000247982A - Production of isocyanatodisiloxane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain in high yield and selectivity the subject compound useful as a surface modifier or crosslinking agent for inorganic and organic materials, a raw rnaterial for adhesives, etc., by reaction of a specific isocyanatosilane with water in the presence (absence) of an organic solvent in a gaseous phase to reduce by-product oligomer formation. SOLUTION: This compound of the formula: [R(NCO)2Si]2O (e.g. 1,3- dimethyl-1,1,3,3-tetraisocyanatodisiloxane) is obtained by reaction of an isocyanatosilane of the formula: RSi(NCO)3 (R is a 1-6C alkyl, alkenyl, alkynyl or the like) (e.g. methyltriisocyanatosilane) in the presence (absence) of an organic solvent such as 1,4-dioxane with (C) water in a gaseous phase pref. at 100-200 deg.C and a pressure of normal pressure to 1 mmHg or so; wherein it is preferable that the amount of the component C to be used is 0.3-0.5 equivalent based on the component A and that of the component B to be used 5-15 wt. times based on the component C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel method for producing isocyanatodisiloxane.

[0002]

2. Description of the Related Art The number of silicon-functional disiloxane compounds synthesized so far is extremely small, and mainly reported are a chloro group, an alkoxy group and a chloro group at the 1,3-position. It is a bifunctional disiloxane compound having a hydroxy group or the like, and among them, only a few are available as general-purpose materials. A tetrafunctional silicon-functional compound having high reactivity and good condensation stability, particularly an isocyanatodisiloxane compound, is an excellent raw material compound as a surface treating agent in the future, and development of a synthesis method thereof is expected.

The above isocyanatodisiloxane compound has the following general formula (II) [R (NCO) ₂ Si] ₂ O (II) (wherein R is an alkyl group or alkenyl group having 1 to 6 carbon atoms, Alkynyl group, aryl group having 6 to 12 carbon atoms or isocyanato group), which is a typical silane compound represented by the following general formula (III) RSix ₃ (III) (where R is X Is a chlorine-free reagent with respect to the compound of the formula (1), does not cause corrosion of the apparatus, has higher reactivity than the compound of the above formula (III) where X is alkoxy, Unlike the compound represented by (III), the film formed on the surface has a higher molecular weight due to a dimer (dimer) structure, and has advantages such as an increase in film strength and adhesion. Therefore, this compound can be used as a surface modifier for inorganic and organic materials, a cross-linking agent, a raw material for an adhesive, a reaction reagent for organic synthesis, a coupling agent, and a precursor for polysiloxane synthesis.

[0004] Isocyanatodisiloxane [R (NCO)
_{As a} method for producing 2Si] ₂ O (R = methyl, vinyl, NCO), a method of reacting RSi (NCO) ₃ (R = methyl, vinyl, NCO) with water in an organic solvent has been known so far. , Tenhiro Gunji, Yoshibe Abe, The Chemical Society of Japan Chugoku-Shikoku and Kyushu Branch Joint Conference, Abstracts, 1D06, p1
04, 1995; Tenji Gunji, Kazue Asakura, Akira Setogawa, Yoshibe Abe, The 70th Annual Meeting of the Chemical Society of Japan, Abstracts, 4H
213, p1146, 1996; only reported in Tenji Gunji, Kazue Asakura, Yoshibe Abe, The 74th Annual Meeting of the Chemical Society of Japan, Abstracts of Lectures, 4C301, P815, 1997.

A conventionally reported method for synthesizing isocyanatodisiloxane [R (NCO) ₂ Si] ₂ O (R = methyl, vinyl, NCO) is based on isocyanatosilane RSi
(NCO) ₃ (R = methyl, vinyl, NCO) and water are reacted in an organic solvent. However, in this method, a trimer or more oligosiloxane is by-produced, the isocyanatodisiloxane yield is at most about 50%, and a trimer or more oligomer is by-produced in a large amount. Therefore, the separation operation is complicated, and the yield is low, so that it cannot be an industrial production method of isocyanatodisiloxane.

Thus, the present invention provides a method for producing an isocyanatodisiloxane from an isocyanatosilane, which reduces the amount of oligomer by-products and can produce the isocyanatodisiloxane with high yield and high selectivity. It is intended to provide.

According to the research and experiments of the present inventors, it is possible to use a large amount of organic solvent without using a large amount of organic solvent as in the conventional liquid phase reaction.
It has been found that the above object can be achieved by reacting in a gas phase system.

[0008]

Accordingly, the present invention provides a compound represented by the general formula (I): RSi (NCO) ₃ (I) wherein R is an alkyl group having 1 to 6 carbon atoms, an alkenyl group, an alkynyl group, and 6 carbon atoms. Is an aryl group or an isocyanato group of the formula (II) [R (NCO) ₂ Si] ₂ O by reacting in the gas phase with water in the absence or presence of an organic solvent. (II) The present invention relates to a method for producing an isocyanatodisiloxane, which comprises producing an isocyanatodisiloxane having (R is as described above).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

As described above, in the present invention, the isocyanatodisiloxane of the general formula (II) is reacted with water in the gas phase in the absence or presence of an organic solvent to produce the isocyanatodisiloxane of the general formula (I). It is to be produced, and this is represented by the following reaction formula. The raw material isocyanatosilane RSi (N
CO) ₃ (R = alkyl group having 1 to 6 carbon atoms, alkenyl group, alkynyl group, allyl group having 6 to 12 carbon atoms or isocyanato group) methyltriisocyanatosilane, ethyltriisocyanatosilane, n- Examples thereof include propyl triisocyanato silane, i-propyl triisocyanato silane, vinyl triisocyanato silane, phenyl triisocyanato silane, and tetraisocyanato silane.

In the present invention, the water used for the isocyanatosilane RSi (NCO) _{3 as the} raw material represented by the general formula I is 0.1.
Two equivalents to 0.7 equivalents are preferred, and 0.3 to 0.5 equivalents are most preferred. If the molar ratio of water is higher than this, the isocyanatodisiloxane [R (NCO) ₂
Si] ₂ O (R is as described above) is further hydrolyzed to produce a trimeric or higher oligosiloxane as a by-product, and the yield is significantly reduced.

Organic solvents can be used to reduce the concentration of water that reacts as a gas, and that the starting isocyanatosilane reacts stoichiometrically with water at the molecular level to minimize side reactions. Organic solvent is acetone mixed with water,
Ketones such as methyl ethyl ketone and methyl isopropyl ketone, diethyl ether, tetrahydrofuran, 1,
Ethers such as 4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and acetonitrile are used, but they are mixed with water at an arbitrary ratio, and methyl ethyl ketone and methyl isopropyl having similar boiling points and vapor pressures are used. Ketone, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and acetonitrile are desirable. The amount of organic solvent used is 5
To 15 times by weight, and when the amount of the organic solvent used is larger than this, the volumetric efficiency is reduced.

The reaction temperature is a temperature at which the raw material isocyanatosilane is vaporized under a predetermined pressure, and the heating temperature of water and the solvent is a temperature at which the mixture is vaporized at a predetermined pressure, flow rate, and time as a mixed gas. The reaction temperature is generally between 80 ° C and 250 ° C, preferably between 100 ° C and 200 ° C.

The reaction pressure is preferably from normal pressure to about 1 mmHg. When performing under reduced pressure, the pressure is particularly 20 to 50 mm.
Hg is preferred.

[0015] The reaction time is sufficient to complete the introduction of water or a mixture of water and an organic solvent into the reaction system at a predetermined pressure and flow rate. Further, the isocyanatodisiloxane represented by the general formula (II) obtained by the present invention [R
(NCO) ₂ Si] ₂ O (R = as described above) can be easily isolated by distillation under reduced pressure. In addition, cyanic acid (H
NCO) is by-produced and can be removed from the reaction system during the reaction as a gas or as an insoluble solid by polymerization.

This reaction is carried out, for example, using the apparatus shown in FIGS. FIG. 1 shows the case where the reaction is carried out under reduced pressure, and FIG. 2 shows the case where the reaction is carried out at normal pressure.

In FIG. 1, reference numeral 1 denotes a four-necked flask having a fixed volume, and a ball inlet cooler 3 equipped with a two-way cock 2 is connected to a central opening. The two-way cock 2 is connected to a vacuum pump (not shown). One mouth of the four-necked flask 1 is connected via a two-way cock 4 to a two-necked flask 7 equipped with a flow meter 5 with a needle valve and a two-way cock 6. 8
Is a mechanical stirrer used in the four-necked flask 1 and operated by an external power supply to agitate the liquid in the flask 1, and 9 and 10 are thermometers attached to the flask 1 and the flask 7, respectively.

When operating the reactor of FIG.
A fixed amount of the raw material isocyanatosilane is placed in a one-necked flask 1, while an appropriate amount of water or a mixture of water and an organic solvent is placed in a two-necked flask 7. The four-necked flask 1 is heated and reduced to a predetermined temperature and a predetermined pressure. Under this pressure, the two-way cock 4 is adjusted from the two-necked flask 7 maintained at a predetermined temperature, and water is used as a gas or water is used as a mixed gas with an organic solvent so as to have a predetermined flow rate with the flowmeter 5. 4
It is introduced into a one-necked flask 1. In the four-necked flask 1, the raw material isocyanatosilane is vaporized under heating and reduced pressure, and an adjusted amount of water is introduced into the gas as a gas or a mixed gas of water and an organic solvent. Always reacts with water at a lower molar ratio in the gas phase of the four-necked flask 1 and the ball inlet cooler 3 to give the general formula II
The target compound isocyanatodisiloxane represented by is produced. After the introduction of water or the mixed gas is completed, the unreacted substances and the solvent are removed, and then distillation under reduced pressure is performed to obtain a target compound. The produced isocyanatodisiloxane has a lower boiling point than that of the raw material isocyanatosilane, so it is liquefied. Further, a side reaction of contacting with water vapor and hydrolyzing to produce a trimeric or higher oligosiloxane is kept to a minimum.

In FIG. 2 showing an apparatus for performing a reaction under normal pressure, the same parts as those in FIG. 1 are denoted by the same reference numerals. In FIG. 2, the two-way cock 4 of the four-necked flask is directly connected to the three-necked flask 11. One port of the three-necked flask 11 is connected to a nitrogen supply source via a flowmeter 5 with a needle valve and a two-way cock 6. During operation, the two-way cock 4 is closed, and the reaction system is purged with nitrogen. Next, the raw material compound isocyanatosilane is supplied to the four-necked flask 1, the cock 2 is opened, the cock 4 is closed, and the raw material compound is heated to reflux. Next, water or water and an organic solvent are charged into a three-necked flask 11. The cock 4 connected to the flask 11 is opened, and nitrogen is allowed to flow while adjusting the flow meter 5 with a needle valve. Water or water and an organic solvent are introduced, and then unreacted substances and the solvent are removed under reduced pressure, followed by distillation under reduced pressure to obtain the target compound isocyanatodisiloxane.

As described above, when isocyanatodisiloxane is produced by reacting isocyanatosilane with water in the gas phase according to the present invention, a large amount of solvent is not required unlike the case of reacting in a liquid phase system, By-products of oligomers larger than the isomer are greatly suppressed, and the by-product cyanic acid (HNCO) is easily separated and removed. Therefore, the target isocyanatodisiloxane compound has a high yield of as much as 80%. Can be obtained at

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples of the present invention. Thus, it will be apparent that the target compound can be obtained in a high yield according to the method of the present invention even in the conventional method.

[0022]

[Embodiment 1] Internal volume 200 m shown in FIG.
l, a four-necked flask 1, a mechanical stirrer 8, a ball-in cooler 3 equipped with a two-way cock 2, thermometers 9 and 100
A two-way cock 4 equipped with a flow meter 5 with a needle valve was connected to a mold flask 7 having a two-ml bottle, and the inside of the reaction system was purged with nitrogen. After 67.67 g (0.40 mol) of methyltriisocyanatosilane was put into the four-necked flask 1, the cock 2 was opened and the cock 4 was closed.
Methyltriisocyanatosilane was heated and refluxed at 05 ° C. Next, 3.60 g (0.20 mol) of water was added, and 35
The cock 4 connected to the 100 ml two-necked flask 7 kept at a temperature of 2 ° C. was slowly opened, and the flow rate was 2
The needle valve was adjusted to 50 ml / min. After completion of the introduction of water, unreacted substances and the solvent were removed under reduced pressure, and the mixture was distilled under reduced pressure to obtain 1,3-dimethyl-1,1,3,3-.
43. Tetraisocyanatodisiloxane (MTIDS)
56 g (80.0% yield) (Bp. 128.1-12)
9.9 ° C./13 mmHg). [Example 2] A mechanical stirrer 8 and a two-way cock 2 were placed in a four-necked flask 1 shown in FIG.
A two-way cock 4 equipped with a flowmeter 5 with a needle valve was connected to a bulb-containing cooler 3, a thermometer 9, and a 100-ml two-necked flask 7 equipped with a, and the inside of the reaction system was purged with nitrogen.
Methyl triisocyanatosilane 6 in four-necked flask 1
After charging 7.67 g (0.40 mol), cock 2 was opened and cock 4 was closed, and then methyltriisocyanatosilane was heated and refluxed at 25 mmHg and 105 ° C. Next, the cock 4 connected to a 100 ml two-necked flask 7 containing 3.60 g (0.20 mol) of water and 40 ml of 1,4-dioxane and kept at 35 ° C. was slowly opened, and the flow rate was adjusted to 500 ml by a flow meter. / Min was adjusted for the needle valve. After the introduction of the gas mixture,
The unreacted substances and the solvent were removed under reduced pressure, and MTI was distilled under reduced pressure.
DS 45.95 g (85.0% yield) (B.p. 12)
8.2-129.8 ° C./13 mmHg). Example 3 A 200-ml four-necked flask 1 shown in FIG.
A bulb 4 equipped with a flowmeter 5 equipped with a needle valve was connected to a bulb cooler 3, a thermometer 9, and a 100-mL two-neck flask 7 to replace the inside of the reaction system with nitrogen. In a four-necked flask 1, 72.4 vinyltriisocyanatosilane
After charging 7 g (0.40 mol), cock 2 was opened and cock 4 was closed, and then vinyl triisocyanatosilane was heated and refluxed at 25 mmHg and 110 ° C. Next, 3.60 g (0.20 mol) of water and 1,4-dioxane 4
The cock 4 connected to the 100 ml two-necked flask 7 containing 0 ml and kept at 35 ° C. was slowly opened, and the needle valve was adjusted with a flow meter so that the flow rate became 500 ml / min. After completion of the introduction of the mixed gas, unreacted substances and the solvent were removed under reduced pressure, followed by distillation under reduced pressure to obtain a boiling point of 90.
47.09 g of a 9-94.2 ° C./0.9 mmHg fraction was obtained. Figure 3 The infrared absorption spectrum of this fraction, ¹ H N
FIG. 4 shows the MR spectrum and FIG. 5 shows the ¹³ C NMR spectrum.
FIG. 6 shows the ²⁹ Si NMR spectrum, and Table 1 shows the assignment of these spectra. From these results, it was confirmed that this fraction was 1,3-divinyl-1,1,3,3-tetraisocyanatodisiloxane (VTIDS).
In addition, as a result of mass spectrometry (MS), 1, 3
A peak of 267, in which one vinyl group was eliminated from divinyl-1,1,3,3-tetraisocyanatodisiloxane, was observed, and the silicon content by a wet method was 18.9% (theoretical value: 19.1%). All matched VTIDS. VTI
The yield of DS was 80.0%.

[0023]

[Table 1] [Example-4] A mechanical stirrer 8 and a two-way cock 2 were placed in a four-necked flask 1 shown in FIG.
A bulb 4 equipped with a flowmeter 5 equipped with a needle valve was connected to a bulb cooler 3, a thermometer 9, and a 100-mL two-neck flask 7 to replace the inside of the reaction system with nitrogen. In a four-necked flask 1 phenyl triisocyanatosilane 92.
After charging 4 g (0.40 mol), the cock 2 was opened and the cock 4 was closed, and then phenyltriisocyanatosilane was heated and refluxed at 25 mmHg and 110 ° C. Next, 3.60 g (0.20 mol) of water and 1,4-dioxane 4
The cock 4 connected to the 100 ml two-necked flask 7 containing 0 ml and kept at 35 ° C. was slowly opened, and the needle valve was adjusted with a flow meter so that the flow rate became 500 ml / min. After completion of the introduction of the mixed gas, unreacted substances and the solvent were removed under reduced pressure, and the mixture was distilled under reduced pressure, and 61.34 g of 1,3-diphenyl-1,1,3,3-tetraisocyanatodisiloxane (PTIDS) was obtained (yield 77). .8%)
(B.p. 123.2-128.3 ° C / 4.5 mmH
g) was obtained. [Example-5] A mechanical stirrer 8 and a two-way cock 2 were placed in a four-necked flask 1 having an inner volume of 200 ml as shown in FIG.
A bulb 4 equipped with a flowmeter 5 equipped with a needle valve was connected to a bulb cooler 3, a thermometer 9, and a 100-mL two-neck flask 7 to replace the inside of the reaction system with nitrogen. 78.46 g of tetraisocyanatosilane in the four-necked flask 1
(0.40 mol), the cock 2 was opened and the cock 4 was closed, and then the tetraisocyanatosilane was heated and refluxed at 20 mmHg and 140 ° C. Next, 3.60 g of water
(0.20 mol) and 40 ml of 1,4-dioxane, and a 100 ml two-necked flask kept at 35 ° C.
Was slowly opened, and the needle valve was adjusted with a flow meter so that the flow rate became 500 ml / min. After the completion of the introduction of the mixed gas, unreacted substances and the solvent were removed under reduced pressure, and distilled under reduced pressure to obtain 40.13 g of hexaisocyanatodisiloxane (HIDS) (yield 61.9%).
(B.p. 123.3-128.3 ° C / 4.5 mmH
g) was obtained. [Example-6] A mechanical stirrer 8 and a two-way cock 2 were placed in a four-neck flask 1 having an inner volume of 200 ml as shown in FIG.
A flowmeter with a needle valve 5, a thermometer 10, and a two-way cock 4 were attached to a ball-in cooler 3, a thermometer 9, and a 100 ml three-necked flask 11 equipped with
connected to the four-necked flask. The two-way cock 4 was closed, and the inside of the reaction system was replaced with nitrogen. 67.67 g (0.40 mol) of methyltriisocyanatosilane in the four-necked flask 1
Then, the cock 2 was opened and the cock 4 was closed, and then methyltriisocyanatosilane was heated to 165 ° C. and refluxed. Next, 3.60 g (0.20 mol) of water and 1,4-
100 ml with 40 ml of dioxane and kept at 35 ° C
The cock 4 connected to the three-necked flask 11 was slowly opened, and the flow rate of the nitrogen gas was 440 ml / min.
The needle valve was adjusted so that After the introduction of the mixed gas was completed, unreacted substances and the solvent were removed under reduced pressure, and distilled under reduced pressure to obtain 41.21 g (75.0%) of MTIDS. Comparative Example 1 Method for Producing MTIDS in Liquid Phase A 200-ml four-necked flask equipped with a mechanical stirrer, a condenser and a dropping funnel was purged with nitrogen in the reaction system. 33.84 g (0.20 mol) of methyltriisocyanatosilane and 40 ml of tetrahydrofuran were charged into the flask and kept at 0 ° C. Here, 1.80 g (0.10 mol) of water and tetrahydrofuran 4
0 ml of the mixture was added dropwise from the dropping funnel over 1 hour.
After completion of the dropwise addition, the mixture was stirred for 2 hours while maintaining the temperature at 0 ° C, and then refluxed at 70 ° C for 2 hours. After the generated solid was separated by filtration, the solvent was removed under reduced pressure. Unreacted monomer 8 is contained in this concentrate.
%, The desired dimer isocyanatodisiloxane was 58%, and the trimer or higher oligomer was 34%. This concentrated liquid was distilled under reduced pressure to obtain MTIDS 12.37.
g (45.8% yield). Comparative Example 2 Method for Producing VTIDS in Liquid Phase A 200-ml four-necked flask equipped with a mechanical stirrer, a condenser and a dropping funnel was purged with nitrogen in the reaction system. 36.20 g (0.20 mol) of vinyl triisocyanatosilane and 40 ml of tetrahydrofuran were charged into the flask and kept at 0 ° C. Here, 1.80 g (0.10 mol) of water and tetrahydrofuran 4
0 ml of the mixture was added dropwise from the dropping funnel. After dropping,
The mixture was stirred for 2 hours while maintaining the temperature at 0 ° C, and then refluxed at 70 ° C for 2 hours. After the solid was separated by filtration, the solvent was removed under reduced pressure. The concentrated solution contained 15% of unreacted monomer, 41% of a target disiloxane, and 44% of a trimer or higher oligomer. This concentrated solution is distilled under reduced pressure to obtain VTIDS1.
2.37 g (45.8% yield) were obtained. Comparative Example 3 Method for Producing HIDS in Liquid Phase A mechanical stirrer, a condenser, and a dropping funnel were attached to a 200-ml four-necked flask, and the inside of the reaction system was purged with nitrogen. In this flask, 39.23 g (0.20 mol) of tetraisocyanatosilane and 40 parts of benzene were added.
ml was added and kept at 0 ° C. Here, 1.80 g of water
A mixture of (0.10 mol) and 40 ml of benzene was dropped from a dropping funnel. After the completion of dropping, keep the temperature at 0 ° C for 2 hours.
Stirred for hours. After the solid was separated by filtration, the solvent was removed under reduced pressure. The concentrated solution was distilled under reduced pressure to obtain 8.11 g of HIDS (yield: 25.
0%).

[0024]

As is apparent from the above description, when isocyanatosilane and water are reacted in the gas phase under normal pressure or reduced pressure according to the present invention, a large amount of reaction is required as in the case of the liquid phase system. The solvent is not required, the by-product of the oligomer is largely suppressed, and the target product, isocyanatodisiloxane, can be obtained in a high yield and a high selectivity.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an apparatus for implementing the method of the present invention.

FIG. 2 is an explanatory view showing another example of an apparatus for performing the method of the present invention.

FIG. 3 is an infrared absorption spectrum of the product of Example 3 of the present invention.

FIG. 4 is a ¹ H NMR spectrum of the same product.

FIG. 5 is a ¹³ C NMR spectrum of the same product.

FIG. 6 is a ²⁹ Si NMR spectrum of the same product.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Miho Watanabe 4-830-45 Nonoshita, Nagareyama-shi, Chiba F-term (reference) 4H049 VN01 VP02 VQ44 VQ78 VR21 VR53 VR54 VS44 VT32 VT33 VU21 VU36 VV21 VV23 VW02 VW33

Claims (2)

[Claims] 1. A compound of the general formula (I) RSi (NCO) ₃ (I) wherein R is an alkyl group having 1 to 6 carbon atoms, an alkenyl group, an alkynyl group, an aryl group having 6 to 12 carbon atoms or an isocyanato group. Is reacted with water in the gas phase in the absence or presence of an organic solvent to produce a compound of the general formula (II) [R (NCO) ₂ Si] ₂ O (II) (R is as described above) A method for producing an isocyanatodisiloxane, comprising producing an isocyanatodisiloxane having the formula (1). 2. The method according to claim 1, wherein the reaction is carried out under normal pressure or reduced pressure.