JP3825175B2 - Method for promoting hydrosilylation - Google Patents

Description

【００２８】
本発明の方法でヒドロシリル化反応を行うと１５時間で反応率が１００％であったが、比較例１、２の従来法では１５時間での反応転化率は低く、反応完了までに３０時間を要した。これによって本発明方法の反応促進効果が示されている。
反応完了時におけるシリル官能化率は比較例１、２にくらべて実施例１、２の方が高い値であり、この効果でゴム状硬化物の架橋による引っ張り応力が強い結果が得られている。
【００２９】
【発明の効果】
本発明の方法でアルケニル基を有する化合物のヒドロシリル化を行うことによって従来の反応促進法では不十分であった系についても、十分な反応速度の促進が可能になり、反応生成物を安定的に得ることができた。本発明の方法を用いることにより、触媒消費量を最少化して費用低減が達成できるとともに製品中の残留触媒量が減少するため、製品純度を上げることができる。
【００３０】
また、アルケニル基を有する高分子のヒドロシリル化により架橋可能なシリル基を有する高分子化合物を製造する場合は、反応促進によりシリル基の導入率が向上し、優れた物性を示す硬化物を得ることが可能となった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for hydrosilylation of a compound having an alkenyl group (carbon-carbon unsaturated bond) with a silicon hydride compound. More specifically, the present invention relates to a method for promoting a hydrosilation reaction.
[0002]
[Prior art]
The hydrosilylation reaction is known as a method of reacting an unsaturated compound with silicon hydride.
One of the main problems known in the technical field using this reaction is that the speed is lowered during the reaction or the reaction is stopped under each reaction condition. Onopchenko. A. (J. Org. Chem., 52, 4118, (1987)) and Lewis. L. N. (J. Am. Chem. Soc., 112, 5998, (1990)) and JP-A-5-213972, when the platinum catalyst is deactivated, oxygen is used to reactivate the catalyst. There is a method of using (Japanese Patent Laid-Open No. 8-283339). As for the method of adding an effective substance for promoting the reaction, addition of acetylene alcohols (JP-A-8-231563), addition of unsaturated secondary and tertiary alcohols (JP-A-8-291118), tertiary alcohol There are proposed methods such as addition of benzene (JP-A-8-333373), addition of unsaturated ketones (JP-A-8-2088838), addition of ene-in unsaturated compounds (JP-A-9-25281), and the like.
[0003]
[Problems to be solved by the invention]
Generally, when the unsaturated compound is a polymer, when the unsaturated group concentration is low, when the reaction solution is highly viscous, when reacting with an internal olefin having a hydrosilylation activity lower than that of the terminal olefin, or When the reaction raw material or solvent contains a reaction inhibitor, the hydrosilylation reaction often does not proceed efficiently.
[0004]
In such a system in which the reaction activity decreases, side reaction takes precedence when the reaction time is lengthened. Therefore, in order to increase the reaction yield, it is necessary to use a large amount of expensive noble metal catalyst or reactant, which is very costly. Disadvantageous.
However, it has been clarified that conventionally known methods for promoting a hydrosilylation reaction cannot obtain a sufficient effect under the above-described disadvantageous conditions for hydrosilylation.
[0005]
An object of the present invention is to provide a new method for promoting the hydrosilylation reaction more effectively.
[0006]
[Means for Solving the Problems]
As a result of intensive studies by the present inventors, the hydrosilylation reaction is promoted by carrying out the hydrosilylation reaction in the presence of a substance extracted from soil, clay minerals, activated clay or coal with an organic solvent. And the present invention was completed. Since it has not been conventionally known that such an organic solvent extract can serve as an accelerator for hydrosilylation, the present invention is completely novel. Moreover, since the extract of the present invention is inexpensive, the present invention is extremely practical.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
That is, the present invention
(A) A silicon compound represented by the formula RaXbHcSi (R is an alkyl group having 1 to 20 carbon atoms, and when a is 2 or more, they may be the same or different. X is a halogen, an alkoxy group, an acyloxy group or A hydroxyl group, and when b is 2 or more, they may be the same or different, a and b are integers of 0 to 3 , c is an integer of 1 to 3, and a + b + c = 4)
(B) Compound containing alkenyl group (carbon-carbon unsaturated bond) (C) Catalyst containing Group 8 metal (D) In the presence of a substance extracted from soil, clay mineral, activated clay or coal by an organic solvent In the hydrosilylation process.
[0008]
The present invention also relates to the above hydrosilylation method, wherein (A) is a compound selected from methyldichlorosilane, dimethoxymethylsilane, diethoxymethylsilane, trimethoxysilane, and triethoxysilane.
Moreover, this invention is an organic polymer in which said (B) contains the alkenyl group of molecular weight 500-200000,
(E) It is related with the said hydrosilylation method made to react in presence of the paraffinic plasticizer whose average molecular weight is 200-800.
[0009]
The present invention also relates to the above hydrosilylation method wherein the amount of (D) is 0.0000001 to 0.1 times based on the weight of the compound (B).
The present invention also relates to the above hydrosilylation method, wherein (D) is a substance extracted from activated clay.
Specific examples of the silicon compound [RaXbHcSi, component (A)] used in the present invention include halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and trimethylsiloxydichlorosilane, trimethoxysilane, and triethoxy. Silane, dimethoxymethylsilane, methoxydimethylsilane, dimethoxyphenylsilane, alkoxysilanes such as 1,3,3,5,5,7,7-heptamethyl-1,1-dimethoxytetrasiloxane, methyldiacetoxysilane, trimethylsiloxy In the molecule such as acyloxysilanes such as methylacetoxysilane, dimethylsilane, trimethylsiloxymethylsilane, 1,1,3,3-tetramethyldisiloxane, 1,3,5-trimethylcyclotrisiloxane Hydrosilanes having two or more bonds, alkenyloxysilanes such as methyldi (isopropenyloxy) silane, and the like. Among these, methyldichlorosilane, dimethoxymethylsilane, diethoxymethylsilane, trimethoxysilane, Triethoxysilane or the like is preferable, but is not limited thereto.
[0010]
The amount of the silicon compound (RaXbHcSi) used in the present invention is not particularly limited, but is usually 0.1 to 20 mol with respect to 1 mol of the alkenyl group, and considers economics on an industrial scale. In some cases, 0.5-3 mol is preferred.
The catalyst used in the present invention has a group 8 metal of the periodic table, such as cobalt, nickel, ruthenium, rhodium, palladium, iridium, and platinum (platinum). Complex. Specifically, for example, platinum metal, chloroplatinic acid, a complex of chloroplatinic acid and alcohol, aldehyde, ketone, etc. on a carrier in which solid platinum is supported on a carrier such as simple substance of platinum, alumina, silica, carbon black, etc. Platinum compounds, platinum-olefin complexes [e.g. Pt (CH2 = CH2) 2 (PPh3), Pt (CH2 = CH2) 2Cl2], platinum-vinylsiloxane complexes [Pt {(vinyl) Me2SiOSiMe2 (vinyl)}, Pt {Me (Vinyl) SiO} 4], platinum-phosphine complexes [Ph (PPh3) 4, Pt (PBu3) 4], platinum-phosphite complexes [Pt {P (OPh) 3} 4], etc. Applies to Examples include dicarbonyldichloroplatinum and platinum-hydrocarbon complexes described in Ashby US Pat. Nos. 3,159,601 and 3,159,622, and platinum-alcoholate catalysts described in Lamoreaux US Pat. No. 3,220,972. . Further, the platinum chloride-olefin complex described in Modic US Pat. No. 3,516,946 is also useful in the present invention.
[0011]
These catalysts may be used alone or in combination of two or more. From the viewpoint of reaction activity, chloroplatinic acid, platinum-olefin complex, platinum-acetylacetonate complex, platinum-vinylsiloxane. Complexes are preferred.
Although there is no restriction | limiting in particular as a usage-amount of a catalyst, Usually, it is preferable to use the platinum catalyst in 10-1 to 10-8 mol with respect to 1 mol of alkenyl groups, and to use it in the range of 10-3 to 10-6 mol. . If the amount is less than 10-8 mol, the hydrosilylation reaction may not proceed sufficiently. Moreover, it is preferable not to exceed 10-1 mol from a viewpoint of economical efficiency and the corrosiveness of a catalyst.
[0012]
The catalyst is also diluted in an inert solvent for ease of handling and stabilization. The solvent is preferably a hydrocarbon solvent such as benzene, toluene or xylene, or a halogenated hydrocarbon, alcohol, glycols, ethers, esters or the like.
Specific examples of the compound having an alkenyl group (carbon-carbon unsaturated bond) subjected to the reaction in the method of the present invention include alpha olefins such as ethylene, propylene, 1-butene and 1-hexene, cyclohexene, trans There are 2-hexene, butadiene, decadiene, and allyltrimethylsilane.
[0013]
By performing hydrosilylation of a polymer compound having an alkenyl group (carbon-carbon unsaturated bond), a polymer compound having a silyl group (that is, a group having a silicon atom) at the terminal can be obtained. For example, when methyldimethoxysilane is used, a polymer compound having a dimethoxysilyl group which is a hydrolyzable silyl group at the terminal can be obtained. A polymer having a hydrolyzable silyl group at its terminal is useful because it can form a crosslinked product by a silanol condensation reaction with moisture in the air (Japanese Patent Laid-Open No. 63-6041). Such a polymer compound having a silyl group is used in applications requiring weather resistance, heat resistance, and moisture permeability, such as adhesives, pressure-sensitive adhesives, paints, sealing materials, and waterproofing materials.
[0014]
The main chain component of the polymer compound having an alkenyl group (carbon-carbon unsaturated bond) includes a hydrocarbon main chain, a halogenated hydrocarbon main chain, a saturated hydrocarbon main chain, a polyether main chain, and a polyester. Examples thereof include, but are not limited to, system main chains, polyamide main chains, and polyimide main chains. Preferred as the main chain component of the polymer compound having a silyl group are isobutylene, olefins having 5 to 12 carbon atoms, conjugated dienes, nonconjugated dienes, vinyl ethers, aromatic vinyl compounds, norbornenes, and cyclopentadiene. And polymers such as dicyclopentadiene and vinylsilane, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.
[0015]
Examples of particularly preferred polymer compounds having an alkenyl group (carbon-carbon unsaturated bond) include polypropylene oxide having an allyl group at the end and polyisobutylene having an allyl group at the end. Known methods for synthesizing polyisobutylene having an allyl group at its terminal include reaction of polyisobutylene with allyltrimethylsilane (JP-A 63-105005) and reaction with dienes (JP-A 4-288309). .
[0016]
The hydrosilylation reaction of the present invention can be carried out in the absence of a solvent or in the presence of a solvent. As the solvent for the hydrosilylation reaction, hydrocarbons, halogenated hydrocarbons, ethers and esters can be usually used, but heptane, hexane, benzene, toluene, xylene and the like are preferably used. In particular, when hydrosilylation of a polymer compound is performed, a method using a solvent for liquefaction or viscosity reduction is preferred. A plasticizer added in the step of commercializing the polymer compound can be used as a reaction solvent. When the molecular weight of the polymer compound having an alkenyl group is 500 to 200,000, for example, a paraffinic plasticizer having a molecular weight of 200 to 800 is preferably used as the reaction solvent. Examples of such a plasticizer include a mixture having a composition ratio of 50 to 90% paraffin, 10 to 50% naphthene, and about 1% aroma. Specific examples of such a plasticizer include polybutene, hydrogenated polybutene, α-methylstyrene oligomer, biphenyl, triphenyl, triaryldimethane, alkylene triphenyl, liquid polybutadiene, hydrogenated liquid polybutadiene, and alkyldiphenyl. Hydrocarbon compounds such as BAA-15 (Daihachi Chemical), P-103, W320 (Dainippon Ink), PN-150 (Adeka Argus), adipate compounds, TOTM, TITM (New Japan Rika), W Petroleum process oils such as trimellitic acid ester compounds such as NS-700 (Dainippon Ink), NS-100, NM-26, NP-24, PS-32, PW-32, PX-32 (Idemitsu Kosan) Alkene-68 (Nippon Petroleum Detergent), BF-1000 (Adeka Argus), KE-82 (Arakawa Chemical), DOTP (New Nippon Rika), etc. are preferable, and alkene-68, PS-32, PW-32, PX-32, DOTP, NS-100, TOTM, etc. are particularly preferable in that the loss on heating is small. However, it is not necessarily limited to these.
[0017]
In the present invention, the gas phase part of the reactor for carrying out the hydrosilylation reaction may be composed of only an inert gas such as nitrogen or helium, or can be carried out in the presence of oxygen. When performing a hydrosilylation reaction, the reactor gas-phase part may be implemented in presence of inert gas, such as nitrogen and helium, from a safety viewpoint. However, when the hydrosilylation reaction of the present invention is performed, if the gas phase part of the reactor is used in the presence of an inert gas such as nitrogen or helium, the hydrosilylation reaction rate tends to decrease.
[0018]
In the present invention, the hydrosilylation reaction can be promoted safely in the presence of oxygen by setting the oxygen concentration in the gas phase of the reactor to a value that avoids the explosive mixture composition. The oxygen concentration in the gas phase part of the reactor can be, for example, 0.5 to 10%.
Furthermore, in this invention, in order to suppress that a reaction solvent and a plasticizer are oxidized with oxygen, hydrosilylation reaction can be performed in presence of antioxidant. As the antioxidant, a phenolic antioxidant having a function of a radical chain inhibitor, such as 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4- Dimethyl-6-tert-butylphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), tetrakis {methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate} methane, 1,1,3-tris (2-methyl-4 -Hydroxy-5-tert-butylphenyl) butane and the like can be used. As the same radical chain inhibitor, amine-based antioxidants such as phenyl-β-naphthylamine, α-naphthylamine, N, N′-di-sec-butyl-p-phenylenediamine, phenothiazine, N, N′-diphenyl- Although p-phenylenediamine etc. can also be used, it is not limited to these.
[0019]
In the present invention, the hydrosilylation reaction temperature is usually 30 ° C. or higher and 200 ° C. or lower, and preferably 50 ° C. or higher and 120 ° C. or lower.
In the present invention, any conventionally known soil, clay mineral, activated clay, or coal can be used.
The activated clay used in the present invention is an acid-treated natural clay called acid clay, and contains silicon, aluminum, iron and the like as constituent elements. A particle size of about 15 to 200 mesh is commercially available, but a suitable one can be selected from powder and granules according to the contact method.
[0020]
As the organic solvent used in the extraction in the present invention, hydrocarbons, halogenated hydrocarbons, ethers, and esters can be usually used. Preferred are hydrocarbons such as hexane, heptane, toluene, and xylene. Mention may be made of solvents.
In the present invention, soil, clay mineral, activated clay or coal is a natural organic component or inorganic component, and components soluble in organic solvents are extracted with hydrocarbon solvents such as hexane and toluene. In addition, the solvent can be concentrated. In the present invention, it is also possible to extract natural organic components or inorganic components in soil, clay minerals, activated clay, or coal using a reaction substrate for hydrosilylation reaction or a reaction solvent for hydrosilylation reaction. In one aspect of the present invention, the amount of a substance extracted from soil, clay mineral, activated clay, or coal by an organic solvent used in the reaction can be 0.000001 wt% to 50 wt% based on the weight of the reaction substrate. More preferably, it is 0.00001 wt%-10 wt%. If the addition amount is more than 50%, the reaction promoting effect is hardly improved, and if it is less than 0.000001%, a sufficient reaction promoting effect cannot be obtained. In the present invention, the “amount of the extracted substance” does not include the amount of organic solvent or plasticizer used in the extraction.
[0021]
【Example】
Next, more specific explanation will be given by giving examples of the method of the present invention. In this example, the molecular weight of the polymer was confirmed by GPC measurement (polystyrene standard, polystyrene gel column used, mobile phase was chloroform).
Example 1
40 kg of allyl group-terminated polyisobutylene (molecular weight 15000, number of allyl groups per polymer molecule of 2.0) is reacted with 1.4 kg of dimethoxymethylsilane. As a reaction solvent, 20 kg of process oil PS-32 (Idemitsu Petroleum) was used. As the catalyst, 2.8 g of platinum vinylsiloxane complex (0.00000831 mmol / μL xylene solution) was added. The gas phase part of the reactor was charged with nitrogen containing 5 vol% oxygen to a pressure of 5 atm. 12 g of 2,6-di-tert-butyl-p-cresol was added as an antioxidant. 3 kg of activated clay and 4 kg of toluene were brought into contact with each other to elute the reaction promoting substance into toluene, and the toluene was evaporated and concentrated 100 times to add 0.04 kg to the reactor.
[0022]
After the reaction was started by adding dimethoxymethylsilane, mixing and stirring were continued at 70 ° C. for 15 hours.
In order to evaluate the hydrosilylation reaction conversion rate of the allyl group, a sample of the reaction solution was taken and the concentration of the allyl functional group was measured by an infrared spectrophotometer. As a result, the remaining allyl group was not detected, and therefore the reaction conversion rate was 100. %Met. When the introduction rate of dimethoxymethylsilane was measured for this sample by 1H-NMR measurement, 1.5 silyl groups were introduced per molecule of polymer.
[0023]
The thus-prepared silyl group-terminated polymer was subjected to condensation crosslinking to produce a regular (JIS No. 3 dumbbell: width 5 mm × thickness 2 mm) rubber-like cured product, and the cured product modulus was evaluated by an extension test. Condensation crosslinking was carried out at 50 ° C. for 20 hours by mixing at a weight ratio of 0.67 water and 2.5 tin octylate to 100 weight mixture of silyl group-terminated polymer and plasticizer PS-32. This rubber-like cured product was subjected to a tensile test, and the tensile stress at 50% elongation was 1.2 kg / cm 2. The results are summarized in Table 1.
Example 2
In 150 kg of a toluene / ethylcyclohexane (8/2 volume ratio) mixed solution, 40 kg of allyl group-terminated polyisobutylene (molecular weight: 15,000, allyl functionalization rate: 2.0 number of terminal allyl groups per polymer molecule) The reaction promoting substance contained in the activated clay was eluted by circulating the solution through the activated clay packed bed (10 kg). Thereafter, the toluene / ethylcyclohexane solvent was removed by evaporation to remove the allyl group-terminated polyisobutylene, and the hydrosilylation reaction was carried out for 15 hours in the same manner as in Example 1 except that the reaction accelerator was not added again.
[0024]
As a result of collecting a sample of the reaction solution and measuring the concentration of the allyl functional group in the same manner as in Example 1, no residual allyl group was detected, and thus the reaction conversion rate was 100%. When the introduction rate of dimethoxymethylsilane was measured for this sample, 1.4 silyl groups were introduced per polymer molecule.
The thus-prepared silyl group-terminated polymer was subjected to condensation crosslinking to prepare a standard rubber-like cured product, and the cured product modulus was evaluated by an extension test. This rubber-like cured product was subjected to a tensile test, and the tensile stress at 50% elongation was 1.1 kg / cm 2. The results are summarized in Table 1.
Comparative Example 1
In Example 1, the hydrosilylation reaction was carried out for 15 hours without adding the reaction accelerator.
[0025]
As in Example 1, a sample of the reaction solution was collected and the concentration of the remaining allyl functional group was measured. As a result, the reaction conversion rate was 70%. When the introduction rate of dimethoxymethylsilane was measured for this sample, 0.7 silyl groups were introduced per polymer molecule.
Further, hydrosilylation was continued, and a sample of the reaction solution was collected 30 hours after the start of the reaction, and the concentration of the remaining allyl functional group was measured. As a result, the reaction conversion rate was 95%. When the introduction rate of dimethoxymethylsilane was measured for this sample, 0.8 silyl groups were introduced per polymer molecule. The thus-prepared silyl group-terminated polymer was subjected to condensation crosslinking to prepare a standard rubber-like cured product, and the cured product modulus was evaluated by an extension test. This rubber-like cured product was subjected to a tensile test, and the tensile stress at 50% elongation was 0.7 kg / cm 2. The results are summarized in Table 1.
Comparative Example 2
Instead of adding the reaction accelerator in Example 1, 0.04 kg of toluene was added and the hydrosilylation reaction was carried out for 15 hours.
A sample of the reaction solution was collected in the same manner as in Example 1 and the concentration of the remaining allyl functional group was measured. As a result, the reaction conversion rate was 75%. When the introduction rate of dimethoxymethylsilane was measured for this sample, 0.8 silyl groups were introduced per polymer molecule.
[0026]
Further, hydrosilylation was continued and 30 hours after the start of the reaction, a sample of the reaction solution was collected and the concentration of the remaining allyl functional group was measured. As a result, the reaction conversion rate was 100%. When the introduction rate of dimethoxymethylsilane was measured for this sample, 1.1 silyl groups were introduced per molecule of polymer. The thus-prepared silyl group-terminated polymer was subjected to condensation crosslinking to prepare a standard rubber-like cured product, and the cured product modulus was evaluated by an extension test. This rubber-like cured product was subjected to a tensile test, and the tensile stress at 50% elongation was 0.8 kg / cm 2. The results are summarized in Table 1.
[0027]
[Table 1]

[0028]
When the hydrosilylation reaction was carried out by the method of the present invention, the reaction rate was 100% in 15 hours, but in the conventional methods of Comparative Examples 1 and 2, the reaction conversion rate in 15 hours was low, and 30 hours were required for completion of the reaction. It cost. This shows the reaction promoting effect of the method of the present invention.
The silyl functionalization rate at the completion of the reaction is higher in Examples 1 and 2 than in Comparative Examples 1 and 2, and this effect has resulted in strong tensile stress due to crosslinking of the rubber-like cured product. .
[0029]
【The invention's effect】
By carrying out the hydrosilylation of a compound having an alkenyl group by the method of the present invention, it becomes possible to accelerate the reaction rate sufficiently even for a system that has been insufficient by the conventional reaction accelerating method, and the reaction product can be stably stabilized. I was able to get it. By using the method of the present invention, the catalyst consumption can be minimized to achieve cost reduction and the amount of residual catalyst in the product can be reduced, so that the product purity can be increased.
[0030]
In the case of producing a polymer compound having a silyl group capable of crosslinking by hydrosilylation of a polymer having an alkenyl group, the introduction rate of the silyl group is improved by promoting the reaction, and a cured product having excellent physical properties is obtained. Became possible.

Claims (5)

(A), (B), (C), hydrosilylation method in the presence of component (D).
(A) A silicon compound represented by the formula RaXbHcSi (R is an alkyl group having 1 to 20 carbon atoms, and when a is 2 or more, each may be the same or different. X is a halogen, an alkoxy group, an acyloxy group or And when b is 2 or more, they may be the same or different, a and b are integers of 0 to 3, c is an integer of 1 to 3, and a + b + c = 4)
(B) Compound containing alkenyl group (carbon-carbon unsaturated bond) (C) Catalyst containing Group 8 metal (D) Substance extracted from soil, clay mineral, activated clay or coal by organic solvent  The method according to claim 1, wherein (A) is a compound selected from methyldichlorosilane, dimethoxymethylsilane, diethoxymethylsilane, trimethoxysilane, and triethoxysilane.  The method according to claim 1, wherein (B) is an organic polymer containing an alkenyl group having a molecular weight of 500 to 200,000 and (E) is reacted in the presence of a paraffinic plasticizer having an average molecular weight of 200 to 800.  The method according to claim 1, wherein the amount of (D) is 0.0000001 to 0.1 times based on the weight of the compound of (B).  The method according to claim 1, wherein (D) is a substance extracted from activated clay.