JPH01157973A - Production of alkenylsuccinic acid anhydride - Google Patents

Abstract

PURPOSE:To suppress formation of tarry by-products and to obtain the title compound useful as an additive for lubricating oil, curing agent for epoxy resin, etc., having excellent tint, by subjecting an olefin and maleic anhydride to thermal addition reaction in the presence of a specific polymer under a specific condition. CONSTITUTION:In obtaining an alkenylsuccinic acid anhydride by subjecting an olefin and maleic anhydride to thermal addition reaction, 5-30wt.%., preferably 10-20wt.% polymer (e.g., polymer obtained by copolymerizing 6-60C alpha-olefin with maleic anhydride in the presence of a radical polymerization initiator) shown by the formula (R is H or 4-58C alkyl; n is 2-30) exists in the reaction mixture, concentration of maleic anhydride in the reaction solution is maintained at 50-30wt.%, preferably 10-20wt.% based on the number of total mols of the olefin and maleic anhydride fed, the reaction is carried out at <=210 deg.C until the reaction ratio of maleic anhydride becomes at least 30% and then the reaction is done by raising temperature by at least >=5 deg.C.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing alkenylsuccinic anhydrides.

Specifically, the present invention suppresses the formation of tar-like byproducts and produces alkenylsuccinic anhydride with a good hue by conducting the total heat addition reaction between an olefin and maleic anhydride under specific conditions. Relating to a method of manufacturing.

[Conventional technology]

Alkenylsuccinic anhydride is a compound that has been attracting attention recently because it has a wide range of uses such as lubricating oil additives, epoxy resin curing agents, resin modifiers, plasticizers, dispersants, and rust inhibitors.

Generally, alkenylsuccinic anhydride is f/10-2 between olefin and maleic anhydride! ; Manufactured by a thermal addition reaction under heating at 0°C, but at this time, by-products such as tar-like substances and high molecular weight polymers are produced, and significant coloring occurs, deteriorating the quality of the product and causing product damage. restrictions will be placed on the use of.

[Problem that the invention seeks to solve]

Various methods have been proposed to suppress the production of the above-mentioned byproducts. For example, the method of adding hydroxy aromatic compounds or amine aromatic compounds (U.S. Patent No. s, ttl
ziii), a method of adding a sterically hindered phenol compound (US Pat.
33720), method of adding phosphorus-containing organometallic ion sequestering agent or orthophosphoric acid (Japanese Patent Publication No. 1989-24.22/
No.), method of adding organic chlorine compounds (Tokuko Sho Taco-2
, 3AAt No.), a method of adding a halogen or a halogen compound (JP-KOKAI SHO jt2-.39A7 (No. 1), a method of adding an organic phosphite ester (JP-KOKAI SHO, !; A-/, t
, 3g No. 2), etc. have been reported.

Although these methods are effective in suppressing the production of the above-mentioned by-products, the effects cannot necessarily be said to be sufficient. Particularly when the reaction temperature is 200'C or higher, methods that add organic chlorine compounds or halogen compounds may have little effect in suppressing by-product formation. It is highly toxic, and although it is not desirable from the viewpoint of work management, it is as corrosive as the tensioning under high temperature conditions, so it is necessary to use equipment made of special materials. shall be.

[Means for solving problems]

In view of the state of the prior art, the present inventors have conducted intensive studies to suppress the production of by-products such as tar-like substances during the thermal addition reaction between olefins and maleic anhydride. By carrying out a thermal addition reaction with and under specific reaction conditions in the presence of a specific polymer, it is possible to suppress the formation of the above tar-like by-products and improve the color and quality problems of the product. The present invention was achieved by discovering that

That is, the gist of the present invention is to provide a method for producing alkenylsuccinic anhydride by subjecting an olefin to a thermal addition reaction with maleic anhydride, in which the reaction system contains the general formula (1): (wherein R is a hydrogen atom or a carbon atom) 41!-3g of an alkyl group, and n represents an integer of 2 to 30) is present in the reaction mixture at a concentration of 3 to 30% by weight, and maleic anhydride in the reaction mixture is The concentration is maintained below 30 moles based on the total moles of charged olefin and maleic anhydride, and the reaction is carried out at a reaction temperature below -10'C until the conversion of maleic anhydride is at least 30%, and then Reduce the reaction temperature to at least &'C
A method for producing alkenylsuccinic anhydride, which is characterized in that the reaction is carried out by raising the temperature of the alkenylsuccinic anhydride.

Next, the present invention will be explained in detail.

The olefin as a raw material in the method of the present invention is a compound having an ethylenically unsaturated double bond, and the number of carbon atoms thereof is usually 2 to SOO, preferably q to ? 00. More preferably, it is g to 100. The olefin may be a single product or a mixture of olefins having different numbers of carbon atoms. For example, a mixture of α-olefins having /co and /4′ carbon atoms (for example, “Dialene /2′l” (registered trademark) manufactured by Mitsubishi Chemical Industries, Ltd.), 76 and 7 carbon atoms,
g of α-olefin mixture (also “dialene 1
4g''), α-olefin mixture with 20-.2g of carbon atoms (also ``Dialene 20g''), 3 with carbon atoms
A mixture of α-olefins having a molecular weight of 0 to 60 (also /''Dialene 30) and the like are preferably used.

In the present invention, when the above-mentioned olefin and maleic anhydride are subjected to a thermal addition reaction, the reaction system is expressed by the following general formula (I): , n represents an integer from 1 to 3o) is present in a specific amount.

A preferable polymer represented by the above general formula (1) is one in which R in the general formula (1) is an alkyl group having a carbon number of 5 g to 5 o, and n is 3 to 20. Good luck!
1-/, 1.

The polymer represented by the above general formula (1) is generally prepared by combining an α-olefin having 6 to 10 carbon atoms and maleic anhydride with a radical polymerization initiator such as di-t-butyl peroxide, t-butyl hydroperoxide, etc. A product obtained by copolymerizing in the presence of a radical generator is used.

The amount of the polymer represented by the above general formula (1) used is 3 to 30% by weight in the reaction mixture, preferably 10-20% by weight.
% by weight. If the amount used is less than the above lower limit, the effect of suppressing the production of by-products such as the tar-like substance will gradually decline as the amount used is reduced. In addition, if the usage amount exceeds the upper limit above, even if the usage amount is increased, the effect of suppressing the production of the above-mentioned byproducts will not change, and on the contrary, it will cause an increase in costs.
This is also undesirable because it causes problems such as deterioration of product quality.

The polymer represented by the above general formula (1) is usually used by being mixed in advance with either an olefin or maleic anhydride and then added to the reaction system.

In the method of the present invention, when a predetermined amount of the polymer represented by the above general formula (1) is present in the reaction system and the olefin and maleic anhydride are subjected to a thermal addition reaction, the concentration of maleic anhydride in the reaction solution is adjusted to The reaction rate of maleic anhydride is at least 30 L%, preferably at least 30 L% based on the total number of moles of the charged olefin and maleic anhydride, and more preferably SO -75%, the reaction temperature is lower than 270°C, preferably 770-200'C, more preferably 1
The first stage reaction is carried out while maintaining the temperature in the range of 70 to 190°C.

In the first stage reaction above, if the concentration of maleic anhydride in the reaction system is higher than the above upper limit, the production of by-products such as the above-mentioned tar-like substances will increase significantly, and the reaction rate of maleic anhydride will decrease. If the temperature shifts to the second stage reaction below the above lower limit, by-products such as the above-mentioned tar-like substances will increase in the second stage reaction, and furthermore, the reaction temperature in the first stage reaction will rise below the above upper limit. If it is too high, by-products such as the above-mentioned tar-like substances will increase significantly, which is not preferable.

As for the method of the first stage reaction, preferably, a predetermined amount of olefin is charged into a reactor in advance, and maleic anhydride is continuously or A method of intermittently adding and reacting is adopted. The charging molar ratio of olefin to maleic anhydride in the above reaction is usually /: 00. t~
l:2, preferably /:θ2g to /:2, more preferably /:l-7:2. Also, the reaction is usually
It is carried out without solvent. Furthermore, although it is usually preferable to carry out the reaction under atmospheric pressure, it can also be carried out under increased pressure or reduced pressure.

The first stage reaction solution is then subjected to a second stage reaction,
By carrying out the reaction at a temperature higher than the reaction temperature of the first stage reaction by 5°C or more, preferably at a temperature 1-10°C higher, and more preferably at a temperature higher by 10-eo°C, maleic anhydride can be produced. The reaction rate can be increased to zao~ioo@.

In addition, unreacted maleic anhydride and olefin can be removed by heating under reduced pressure, if necessary.

The alkenylsuccinic anhydride thus obtained does not produce tar-like by-products, has a good color, and has a melting point of usually -50-9! ; 'C range, also/
The viscosity at 00'C is typically 10-1000 cp. In particular, when α-olefin with a carbon number of 2 g or more is used, the melting point is 55°C to 95° (:,, the viscosity at 100°C is 30 to 50 Cp, and the resin modifier, dispersant, Advantageously used as a rust preventive agent, etc.

〔Example〕

Next, embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

In addition, the method of measuring each physical property in the following examples is as follows.

Melting point: Measured using an automatic melting point measuring device (Mettler FP).

Penetration: ASTM-D-t,? Measured at 25°C according to Co/-6/T.

Saponification value: Measured according to JISK ooqo.

Molecular weight: Measured by GPC under the following conditions.

Equipment - GPC Zu000 column manufactured by Toyo Soda Kogyo ■
TSK gel G (10oo+, 2oo.

+3ooo+ttooo)HXL.

? Jm φ
y (o, g 7 mol) and α-olefin/maleic anhydride copolymer (α in the general formula (1) where R is an alkyl group having 2 g-kg of carbon atoms and n is an integer of S to 10) - Olefin/maleic anhydride copolymer) 9, A g (/, t% based on the total weight of α-olefin and maleic anhydride) was charged into a Pyrex glass reactor and heated to 100°C. The atmosphere was sufficiently replaced with nitrogen gas. Thereafter, maleic anhydride ff & /i (0.g 7 mol) was continuously added dropwise to this at a constant rate over a period of 5 hours.

The concentration of residual maleic anhydride in the reaction solution immediately after the dropwise addition of maleic anhydride was 76.9 moles based on the total number of moles of the charged olefin and maleic anhydride, and the reaction rate of maleic anhydride was 166. Met.

Next, the above reaction solution was further heated for 30 q hours at a temperature of 210°C.
It was allowed to react for a minute. The resulting reaction solution had a reaction rate of maleic anhydride of q ti, s%.

Then pressure! ; mm H? ', temperature/b, 2
Unreacted substances were removed from the reaction solution at ℃.

The resulting reaction solution had no tar-like by-products and had a good color. Its physical properties are shown below.

Melting point: 73. soC Saponification value = 703 Molecular weight 2-7 hiro0 Penetration degree: 5 Comparative example - α-olefin mixture with 3 O-AO carbon atoms ("Daikiren 30") 59 g (0,1) 2 mol) and maleic anhydride? 9. A! ! (o, gt2 mole) fj! : The mixture was charged into a Virex glass reactor, heated to 700'C, and thoroughly purged with nitrogen gas. Next, set this to a temperature of 21
Heat to 0°C, 7. When the reaction was carried out for θ hours, the reaction rate of maleic anhydride was 9A, 0H.

Thereafter, unreacted substances were removed from the reaction solution using a pressure cuff arm HP and a temperature of 40°C.

The resulting reaction solution had a layer of tar-like by-products that settled at the bottom. After removing this tar-like by-product, the product was as shown below.

Melting point: 73. ! ;°C Saponification value: //g Molecular weight: CoSSO Needle size 29.5 Comparative example-2 α-olefin mixture of carbon a3o-go (“Daikiren 30”) and Examples-
The same α-olefin/maleic anhydride copolymer used in 7 q, g i (is% based on the total weight of α-olefin and maleic anhydride) and maleic anhydride, 9 g (0 , 49.7 mol) was placed in a Hilex glass reactor, heated to 1000C, and thoroughly purged with nitrogen gas. Next, heat this to a temperature of 270°C,
When the reaction was carried out for 7.0 hours, the reaction rate of maleic anhydride was 98/m2.

Thereafter, unreacted substances were removed from the reaction solution using a pressure cuff (H) and a temperature of AO°C.

The resulting reaction solution contained very little tar-like byproducts.

Melting point: 7<4.5°C Saponification value: //Otsu Molecular weight: , zi/.

Penetration: 6.0 Comparative Example-3 A mixture of α-olefins having 30 to 60 carbon atoms (“Dialene 30”) Otsu 96I (9 mol) was charged into a Pyrex glass reactor and io.

It was heated to ℃ and sufficiently replaced with nitrogen gas. Thereafter, this was mixed with maleic anhydride/02 g (/
, 0 gmol) was continuously added dropwise at a constant rate over 2.9 hours. The concentration of residual maleic anhydride in the reaction solution immediately after the dropwise addition of maleic anhydride is proportional to the total number of moles of the charged olefin and maleic anhydride, and the reaction rate of maleic anhydride is! A. It was 2%.

The reaction rate was 9.0 g.

The resulting reaction solution contained very little tar-like byproducts.

Melting point = Rita℃ Saponification value 2/2/ Molecular weight: 37θ [Effects of the invention] By-products when producing alkenylconanhydride by thermal addition reaction of olefin and maleic anhydride according to the method of the present invention The formation of is suppressed, and the color and quality of the product are improved.

Patent applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent attorney - Others/names

Claims (1)

[Claims] (1) In a method for producing alkenylsuccinic anhydride by subjecting an olefin to a thermal addition reaction with maleic anhydride,
General formula (I) in the reaction system: ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I
) (wherein, R represents a hydrogen atom or an alkyl group having 4 to 58 carbon atoms, and n represents an integer of 2 to 30) at a concentration of 5 to 30 in the reaction mixture.
The concentration of maleic anhydride in the reaction solution is maintained at 30 mol% or less based on the total number of moles of the charged olefin and maleic anhydride, and the reaction rate of maleic anhydride is at least 30%. 1. A method for producing alkenylsuccinic anhydride, characterized in that the reaction is carried out at a reaction temperature of up to 210°C or less, and then the reaction is carried out by raising the reaction temperature by at least 5°C.