GB2108111A - A maleic anhydride derivative used as a paper sizing agent - Google Patents

Abstract

A paper sizing agent which is excellent in sizing effect and hard water dispersibility consists essentially of water-soluble salts of reaction products and/or their hydrogenated products, which reaction products are prepared by adding maleic anhydride to straight chain internal olefins represented by the following general formula: R1-CH=CH-R2 wherein each of the symbols R1 and R2 is a straight chain alkyl group having 1 to 11 carbon atoms and the sum of the carbon atoms of R1 and R2 is 6 to 12, inclusive. The water soluble salt may be prepared by saponifying the above neutron product.

Description

SPECIFICATION Paper sizing agent (1) Field of the Invention This invention relates to an internal sizing agent for manufacturing paper. More particularly, the invention relates to a synthetic sizing agent which is excellent in sizing effects and dispersing property in hard water.

(2) Description of Prior Art In the paper manufacturing industry, the sizing agents that are prepared from natural rosins or modified rosins, especially fortified rosin sizing agents which are prepared by saponifying maleicmodified rosins, are regarded as most preferable ones and are widely used.

The natural rosin, however, is in unstable supply, and in addition, the price of rosin is on the severe advance. Accordingly, various kinds of synthetic sizing agents as substitutes are investigated.

Water-soluble salts of alkyl or alkenylsuccinic acid are proposed in U.S.P. No. 3,139,373 and methods to use, as sizing agents, alkyl- or alkenylsuccinic acid and its acid anhydrides by dispersing them in water with dispersing agents are proposed in U.S.P. No. 3,102,064 and No. 3,821,069.

However, the former one is unsatisfactory to some extent in view of sizing effect and dispersibility in hard water. The latter ones are defective in storage stability of obtained sizing agents.

In order to eliminate the defects in these alkyl- or alkenylsuccinic acid-type sizing agents, the inventors of the present application have made earnest investigations, thereby accomplishing the present invention, in which it has been found that, among the succinic acid-type compounds, certain water-soluble salts have especially excellent properties not only in sizing effect but also in dispersibility in hard water.

BRIEF SUMMARY OF THE INVENTION It is, therefore, the primary object of the present invention to eliminate the disadvantages of sizing agents used or proposed in the prior art.

Another object of the present invention is to provide a novel and useful sizing agent which is excellent in sizing effect and dispersibility in hard water.

A further object of the present invention is to provide a synthetic sizing agent which can be prepared without difficulty and used in like manner as the ordinary rosin-type sizing agents.

According to the present invention, the paper sizing agent consists essentially of water-soluble salts of reaction products and/or their hydrogenated products, which reaction products are prepared by adding maleic anhydride to straight chain internal olefins represented by the following general formula (I): R1-CH=CH-R2 (I) wherein each of the symbols R and R2 is a straight chain alkyl group having 1 to 11 carbon atoms and the sum of the carbon atom numbers of R1 and R2 is 6 to 12, inclusive.

DETAILED DESCRIPTION OF THE INVENTION The compounds used as starting materials for the sizing agent of the present invention are those having 8 to 14 carbon atoms as defined by the foregoing formula (I). When the carbon atom number of a starting material is 7 or less, even though the dispersibility in hard water (hereinafter referred to as "hard water dispersibility") is good, the sizing effect is not good enough. Further, a starting material having 1 5 or more carbon atoms is undesirable because both the sizing effect and hard water dispersibility are not good. Within the above-mentioned range of carbon atom number of the olefin as a starting material, 10 to 12 is most preferable. As will be seen from the general formula (I), the double bond may exist any place except the terminal a-position.These olefins can be used singly or in combination of two kinds or more. From the economical point of view, it is desirable to use mixed straight chain internal olefins having double bonds at various position.

The straight chain internal olefins themselves are used as starting materials for the preparation of the sizing agent of the present invention. However, the straight chain internal olefin composition containing 25 wt% or less, preferably 5 wt% or less, of a-olefin having similar number of carbon atoms may also be used. Such the straight chain internal olefin containing a small amount of a-olefin is the one containing the a-olefin generated as a by-product in the preparation of straight chain internal olefin or a mixture obtained by mixing -olefin into straight chain internal olefin.

The straight chain internal olefins which are used in the present invention can be prepared by the following methods: (a) Isomerization of a-olefins having 8 to 14 carbon atoms in the presence of acid catalysts such as silica alumina, alumina and aluminium chloride.

(b) Dehydrogenation of n-paraffins in the presence of oxide catalysts such as Cr203.AI20a, MOO3.AI2Og, Fe2O3AI2O and Pt.Li2O.AI2O3.

(c) Disproporation of two molecules of lower molecular a-olefins in the presence of catalysts such as Rue207, WO3.SiO2, MoO3.AI203 and CoO.MoO3.AI203.

The addition of maleic anhydride to the straight chain internal olefin may be carried out according to the present invention in the following manner. That is, the straight chain internal olefin is reacted with maleic anhydride in the presence of a catalyst or without using any catalyst, preferably in an inert atmosphere such as nitrogen gas, at atmospheric pressure or at an elevated pressure, at temperatures in the range from 180 to 2500 C, preferably 190 to 2200 C, and for 1 to 50 hours, preferably 10 to 36 hours. It is not necessary to restrict the molar ratio of maleic anhydride to the olefin, howev"r, it is preferable to use 0.4 to 2 moles of maleic anhydride to 1 mole of the olefin. The reaction product of the present invention can be obtained by removing unreacted olefin and maleic anhydride by distillation after the reaction.

The greater part of the product in this addition reaction is one-to-one adduct, alkenylsuccinic anhydride, as represented by the following general formula (ill):

In the above formula (II), the symbol R' represents a straight chain alkyl group having 1 to 11 carbon atoms, R" represents a hydrogen atom or a straight chain alkyl group having 1 to 10 carbon atoms, and the sum of carbon atoms of R' and R" is 5 to 11. However, small quantities of one-to-two adduct, olefin/maleic anhydride copolymer and maleic anhydride polymer are produced as byproducts. These byproducts may be used together with the one-to-one adduct without being removed. It is of course possible to use only the alkenylsuccinic anhydride by removing the byproducts.From the economical point of view, these byproducts are not removed and the crude reaction product may directly be saponified to obtain a sizing agent. Alkylsuccinic anhydrides are obtained by hydrogenating the foregoing alkenylsuccinic anhydrides without difficulty, which belong to the scope of the present invention.

The alkenylsuccinic anhydride or alkylsuccinic anhydride is then saponified and dissolved by using an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and/or ammonia to obtain a transparent sizing agent.

The sizing agent prepared according to the present invention can be used in quite the same way as the well known rosin-type sizing agent. For example, this internal sizing agent is added to pulp slurry during the beating step or after the beating treatment. Aluminium sulfate is then added and pH is adjusted to about 4.0 to 5.5, preferably 4.2 to 5.0, thereby fixing the sizing agent to the pulp. The quantity of use of the sizing agent of the present invention depends upon the kind and use of paper, however, it is generally about 0.1 to 3 wt% to the pulp.

The sizing agent prepared according to the present invention is quite excellent in sizing effect and hard water dispersibility which are advantageous in paper manufacturing. The sizing agent of the invention can be employed, of course, not only in single but also in combination in any ratio with the ordinary rosin-type sizing agents, petroleum-origin sizing agents, water-soluble salts of a-olefinic alkenylsuccinic acids, water-soluble salts of branched olefinic alkenylsuccinic acids or paper reinforcing agents. Further, the defects such as iow hard water dispersibility in conventional sizing agents can be improved by combinedly,,using the sizing agent of the present invention.

The preparation and uses of the sizing agent of the present invention will be described in more detail in the following Examples. It should be noted, however, that the present invention be limited not by the specific disclosure herein but only by the appended claims.

EXAMPLE 1 A stainless steel continuous reaction vessel was filled with 1 80 ml of silica alumina and the temperature in the reaction vessel was maintained at 1 500C. n-Decane-1 was then fed into the reaction vessel at a flow rate of 3 ml/min. The obtained liquid reaction product was subjected to infrared spectrum analysis. The absorption band of vinyl groups (910 cm-1) decreased, while the absorption band of vinylene groups (965 cm-') newly appeared.The obtained reaction product was internal olefin containing 4.6 wt% of a-olefin. 280 g (2 moles) of the thus obtained n-decene and 1 96 g (2 moles) of maleic anhydride were fed into 1 liter autoclave and the atmosphere in the reaction system was completely replaced with nitrogen gas, which was followed by reaction at 1 900C for 24 hours. The reaction mixture was then put in a reduced pressure distillation apparatus to remove unreacted n decene and maleic an hydride. According to the results of gas chromatography and gel-permeation chromatography on the obtained reaction product, it was determined that the reaction product consisted of 96% of alkenylsuccinic an hydroxide and 4% of one-to-two adduct.It was then saponified with an aqueous solution of potassium hydroxide to obtain a sizing agent of 40% in solid content.

EXAMPLE 2 A stainless steel continuous reaction vessel was filled with 30 ml of Re207.AI203 and n-hexene-1 was fed thereto at a flow rate of 5 ml/min at room temperature. According to the gas chromatographic . analysis of the obtained reaction product, the conversion rate from n-hexene-1 to n-decene-5 was 52%.

The n-decene-5 was recovered from the reaction product by distillation. To a 1 liter autoclave were fed 280 g (2 moles) of the thus obtained n-decene-5 and 196 g (2 moles) of maleic anhydride and the atmosphere in the reaction system was completely replaced with nitrogen gas, which was followed by reaction at 2200C for 24 hours. The reaction mixture was then put in a reduced pressure distillation . apparatus to remove unchanged n-decene and maleic anhydride. According to the results of gas chromatographic analysis and gel-permeation chromatographic analysis on the obtained reaction product, it was determined that the reaction product consisted of 98% of alkenylsuccinic anhydride and 2% of one-to-two adduct.It was then saponified with an aqueous solution of,potassium hydroxide to obtain a sizing agent of 40% in solid content.

COMPARATIVE EXAMPLE 1 n-Decene-1 was modified with maleic anhydride in like manner as Example 2 to prepare an alkqnylsuccinic anhydride. This was saponified with an aqueous solution of potassium hydroxide, thereby obtaining a sizing agent of 40% in solid content.

COMPARATIVE EXAMPLE 2 Oligomerization of isobutylene was carried out in a conventional method by using aluminium chloride as a catalyst. The obtained product was subjected to distillation to recover a fraction of 165-1 840C in boiling point. By mass spectrography and gas chromatography, it was confirmed that the fraction was a mixture of branched olefins of 20%, 60% and 20% of olefins having carbon atoms of 10, 11 and 12, respectively. In like manner as Example 2, the olefin mixture was modified by maleic anhydride to obtain alkenylsuccinic anhydride, which was followed by saponification with an aqueous solution of potassium hydroxide, thereby obtaining a sizing agent of 40% in solid content.

EXAMPLE 3 A reaction vessel was filled with 30 ml of a catalyst, Pt.Li20.Al203 and dehydrogenation was carried out by feeding therein 15 ml/min of n-paraffin mixture (C,O: 8%, C11: 25%, C12 28%, C13: 28%, C,4: 1 1 %) and hydrogen gas.The molar ratio of hydrogen gas to n-paraffins (Hln-paraffins) was 8 and the temperature in the reaction vessel was maintained at 4700 C. The rate of conversion into olefins in the effluent oil was about 12%. The distribution of carbon numbers of the converted defins was determined by gas chromatography, the results of which were C1O: 11%, C1,: 28%, C,2: 25%, C13: 26% and Ca4: 10%. Further, it was confirmed by infrared spectrum analysis that the olefin fraction was a mixture of internal olefins containing 4 wt% of a-olefin.

The mixture of n-paraffins and n-olefins obtained through the foregoing procedure was modified by maleic anhydride in like manner as Example 1 (n-olefin/maleic anhydride = 1/1 in mole). After the reaction, n-paraffin and unreacted n-olefin and maleic anhydride were removed by distillation to obtain alkenyisuccinic an hydride. It was confirmed by analysis that the product contained no one-to-two adduct. After that, the product was saponified with an aqueous solution of potassium hydroxide to obtain a sizing agent of 40% in solid content.

EXAMPLE 4 A 500 ml autoclave was fed with 260 g of alkenylsuccinic anhydride obtained in Example 3 and 4.0 g of Pd-activated carbon catalyst (Pd: 1.0 wt%) and hydrogenation was carried out at 1 200C for 8 hours at a hydrogen pressure of 60 Kg/cm2, thereby preparing 255 g of alkylsuccinic anhydride. The reaction product was then saponified with an aqueous solution of potassium to obtain a sizing agent of 40% in solid content.

EXAMPLE 5 n-Dodecene-1 was isomerized in like manner as Example 1 and after that the product was modified by maleic anhydride. After the reaction, unreacted n-dodecene and maleic anhydride were removed by distillation to obtain alkenylsuccinic anhydride. An analytical result showed that the obtained product was 100% alkenylsuccinic anhydride. It was then saponified with an aqueous solution of potassium hydroxide to obtain a sizing agent of 40% in solid content.

EXAMPLE 6 Disproportionation was carried out in like manner as Example 2 using n-heptene-1 to obtain ndodecene-6. The rate of conversion was 40%. A 500 ml autoclave was fed with 168 g (1 mole) of ndodecene-6 that was recovered by distillation and 59 g (0.6 mole) of maleic anhydride, and after the atmosphere in the reaction system was completely replaced with nitrogen gas, the contents were caused to react at 1 900C for 36 hours. Unreacted n-dodecene-6 and maleic anhydride were removed from the reaction mixture to obtain 145 g of reaction product. The reaction product was saponified with an aqueous solution of potassium hydroxide to obtain a sizing agent of 40% in solid content.

COMPARATIVE EXAMPLE 3 n-Dodecene-1 was modified by maleic anhydride in like manner as Comparative Example 1 to obtain an alkenylsuccinic anhydride which was then saponified with an aqueous solution of potassium hydroxide, thereby obtaining a sizing agent of 40% in solid content.

COMPARATIVE EXAMPLE 4 Dehydrogenation of n-pentadecane was carried out in like manner as Example 3, wherein the content of n-pentadecene in effluent oil was 1 0%. The mixture of n-pentadecane and n-pentadecene was modified by maleic anhydride in like manner as Example 3 and an alkenylsuccinic anhydride was recovered by distillation. A sizing agent of 40% in solid content was prepared from the above product.

COMPARATIVE EXAMPLE 5 In like manner as Comparative Example 4, n-heptane was subjected to dehydrogenation and maleic modification to obtain an alkenylsuccinic anhydride. A sizing agent of 40% in solid content was prepared from the alkenylsuccinic anhydride.

EXAMPLE 7 A sizing agent was prepared by mixing 80 parts of the sizing agent obtained in Example 5 with 20 parts of the sizing agent obtained in Comparative Example 3.

EXAMPLE 8 A mixture of n-a-olefins (Ca: 1 1.1%, C9 12.3%, C,O: 17.10/0, Cur,: 14.7%, C,2: 15.4%, C13 14.3to, C1: 15.1%) was isomerized in like manner as Example 1 to obtain a mixture of straight chain internal olefins containing 6% of cr-olefin. The mixture was caused to react with maleic anhydride in the same conditions as those in Example 1. The reaction product was saponified with an aqueous solution of potassium hydroxide to obtain a sizing agent of 40% in solid content.

Evaluation of Sizing Agents The sizing agents prepared in Examples 1 to 8 and Comparative Examples 1 to 5 were tested through the following test methods to determine their "hard water dispersibilities" and "sizing degrees".

"Hard Water Dispersibility Test" The sizing agent (90 ppm) was dispersed in hard water of 300DH (Ca+2: 214 ppm) and the colloidal state was observed.

"Sizing Test" Paper Making Method (1) Pulp (laubholz bleached kraft pulp, 430 ml in Canadian standard freeness) was dispersed in city water (50do) to prepare 1% pulp slurry and 0.2 wt% of sizing agent was added, then 2.5 wt% (both relative to the pulp) of aluminium sulfate was added thereto. With the pulp slurry, paper of 60 g/m2 in basis weight was made using a TAPPI standard sheet machine and city water (50DH, pH 4.5). After dehydration of wet paper by compression, it was dried at 800C for 5 minutes. The moisture content of paper was adjusted by putting it into an atmosphere of 65% R. H. at 200C for 24 hours to prepare test pieces. The Stchigt sizing degree was then determined according to JIS P 8122.

Paper Making Method (2) Tests were carried out in like manner as the above Paper Making Method (1) except that the water for the sheet machine was hard water (200do, pH 4.5).

The results of the foregoing tests are shown in the following Table 1.

TABLE 1

Sizing Degree (sec.) Hard Water Paper Making Paper Making Sizing Agent Dispersibility Method (1) Method (2) Example 1 Transparent 18.0 18.2 2 2 .. 17.5 17.3 Comparative Example 1 Cloudy 14.3 9.3 .. 2 Transparent 7.4 6.7 Example 3 Colloidal Dispersion 18.3 17.8 Example 4 4 , . 17.0 17.2 .l 5 Transparent 17.2 16.8 .. 6 Colloidal Dispersion 16.8 16.5 Comparative Cloudy Example 3 Coagulation 7.6 3.5 ~ A 4 .. 2.3 0.0 . . ~~ ~ .. 5 Transparent 0.0 0.0 Example 7 .. 17.1 15.2 .. 8 8 15.6 14.3 As will be understood from the above Table 1, the sizing agents according to the present invention are excellent not only in the sizing degree but also in the hard water dispersibility.

Claims (8)

1. A paper sizing agent consisting essentially of at least one water-soluble salt of a reaction product and/or product of hydrogenating said reaction product, which reaction product is prepared by adding maleic anhydride to at least one straight chain internal olefin represented by the following general formula (I): R1-CH=CH-R2 (I) wherein each of the symbols R1 and R2 is a straight chain alkyl group having 1 to 11 carbon atoms and the sum of the carbon atoms of R1 and R2 is 6 to 12, inclusive.

2. The paper sizing agent in claim 1, wherein the carbon atom number of each of said R, and R2 is 1 to 9 and the sum of the carbon atoms of R1 and R2 is 8 to 10.

3. The paper sizing agent in claim 1, wherein said straight chain internal olefin of the general formula (I) is n-decene-5.

4. The paper sizing agent in claim 1, wherein said straight chain internal olefin of the general formula (I) is n-dodecene-6.

5. The paper sizing agent in any one of claims 1 to 4, wherein said addition of maleic anhydride to said at least one straight chain internal olefin is carried out by reacting them at 180 to 2500C for 1 to 50 hours in an inert atmosphere.

6. The paper sizing agent in any one of claims 1 to 5, wherein said at least one water-soluble salt is prepared by saponifying said reaction product and/or product of hydrogenating said reaction product by using an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and/or ammonia.

7. A paper sizing agent as claimed in claim 1, substantially as hereinbefore described with particular reference to the Examples.

8. A paper sizing agent as claimed in claim 1, substantially as illustrated in any one of the Examples.