JPS61119797A - Papermaking size agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a sizing agent for paper manufacturing. More specifically, the present invention relates to a paper sizing agent that not only has excellent emulsifying properties and stability after emulsification and exhibits excellent sizing effects, but also can significantly improve staining during paper making.

[Prior Art] In general, large quantities of fillers such as talc and clay are used in paper manufacturing to improve printability, whiteness, and impart opacity. There is a growing movement to use calcium carbonate, which exists in large quantities and is available at low cost.

However, so-called anionic sizing agents such as rosin-based sizing agents, which have been commonly used as papermaking sizing agents, are used in an acidic sizing method in which they are fixed to the pulp with sulfuric acid. The disadvantage is that calcium carbonate decomposes due to its acidity.

Therefore, in order to solve this problem, various so-called neutral sizing agents have been proposed that can perform sizing in a neutral region or an alkaline region without using sulfate.

For example, in Japanese Patent Publication No. 39-2305, -1lpo-formula (R is a dimethylene group and a trimethylene group, R' is a carbon number of 5 or more) - is selected from an alkyl group, an alkenyl group, an aralkyl group, and an aralkenyl group, respectively. A neutral sizing agent represented by
Publication No. 3-28526 describes -n formula % formula % (wherein R9 and R) are each an alkyl group containing 4 to 10 carbon atoms. ) A sizing agent consisting of a reaction product of an internal olefin and maleic anhydride has been proposed.

In addition, Japanese Patent Application Laid-open No. 57-154495 discloses that the number of carbon atoms is 8 to
A sizing agent consisting of a mixed alkenyl succinic anhydride obtained by adding maleic anhydride to a linear internal olefin mixture has been proposed, in which double bonds are almost evenly distributed at each position except for the α-position of 18. 179″8
No. 98 discloses that the proportion of olefins having 14 to 36 carbon atoms and double bonds at the 2nd, 3rd, and 4th positions is 10 to 65 mol%, and the total is 70%.
Sizing agents have been proposed that contain a reaction product obtained by addition reaction of a linear olefin mixture with maleic anhydride and/or a hydrogenated product of the reaction product.

[Problems to be Solved by the Invention] The above-mentioned conventional sizing agents usually use a water-soluble polymer compound such as cationized starch or a surfactant such as polyoxyalkylene aryl ether, and are emulsified using a homomixer, homogenizer, etc. They are added to paper stocks in the form of aqueous emulsions, but both have insufficient emulsifying properties and stability after emulsification, so they may not produce satisfactory sizing effects or may stain the papermaking system. There are some problems.

Furthermore, the internal oleline disclosed in Japanese Patent Publication No. 53-28526 is obtained by a disproportionation reaction of α-olefin, and has the drawbacks of being accompanied by various difficulties in its production and being expensive.

On the other hand, the internal olefin disclosed in JP-A No. 57-154495 is a linear internal olefin of 400 to
It can be obtained by dehydrogenating at θOO℃ to form a linear internal olefin and then adsorbing and separating it from unreacted paraffin using a molecular sieve, or by isomerizing an α-olefin, which is a low molecular weight polymer of ethylene, and subsequently disproportionating it. It not only contains α-olefin, which is not preferable as a raw material for a sizing agent, but also requires a complicated and expensive process, and has the drawbacks of being expensive.

Furthermore, the linear olefin mixture disclosed in JP-A-59-179898 is obtained by treating α-olefin with an acid catalyst, but the method using this acid catalyst produces heavy polymers. The resulting olefin contains polymers and/or α-olefins because the α-olefins are not completely converted to internal olefins and remain if the production of polymers is suppressed.

Therefore, sizing agents made from this raw material have insufficient emulsifying properties and stability after emulsification, and do not exhibit satisfactory sizing effects.
Another disadvantage is that it tends to stain the papermaking system.

The present inventors have conducted extensive research in order to overcome the above-mentioned drawbacks of conventional sizing agents and develop a neutral sizing agent that not only exhibits excellent sizing effects but also has excellent emulsifying properties and stability after emulsification. As a result, the size effect, emulsifying property, and stability after emulsification of a neutral sizing agent made of an addition reaction product of an olefin and maleic anhydride are determined by the structure of the olefin used as a raw material, double bond distribution, and α-olefin content. In the case of linear olefins, only those with as low an α-olefin and heavy content as possible and with a specific double bond distribution have size effects, emulsifying properties and It has been found that it can be used as a raw material for a sizing agent with excellent stability after emulsification.

Based on the knowledge obtained from these results, we conducted further studies and found that linear olefins obtained by isomerizing α-olefins using a specific method do not contain any α-olefins and are heavy. Not only is the production of minute amounts extremely small, but
Because it has a double bond distribution suitable for a sizing agent raw material without going through the disproportionation process, sizing agents made from this raw material have excellent sizing effects, emulsifying properties, and stability after emulsification, and are resistant to stains in papermaking systems. The inventors have found that the occurrence of oxidation is also significantly improved, and have completed the present invention.

[Means for Solving the Problems] That is, the present invention provides (A) a salt of an organic acid of a transition metal of group 1 of the periodic table or a complex of a transition metal of group 1 of the periodic table, and (B) an organoaluminum compound. A linear internal olefin or a mixture thereof that does not contain an α-olefin, obtained by isomerizing a linear α-olefin having 16 to 20 carbon atoms or a mixture thereof using a catalyst consisting of and a carbon number of 16 to 20 in which the proportion of olefins having a double bond at the 4-position is 35 mol% or less, and the total is 55 mol% or more and less than 70 mol%.
The present invention relates to a paper sizing agent containing a reaction product obtained by the addition reaction of a linear internal olefin or a mixture thereof with maleic anhydride.

As mentioned above, the linear internal olefin or mixture thereof, which is the raw material for the neutral sizing agent in the present invention, is obtained by isomerizing a linear α-olefin having a carbon number within a specific range using a specific catalyst. It is characterized by the content of olefins having double bonds at specific positions, but it is also characterized in that it does not contain any α-olefins and contains almost no polymers, Extremely excellent as a raw material for neutral sizing agents.

That is, the linear internal olefin or the mixture thereof in the present invention is characterized in that it is produced using a novel catalyst that has not been previously used in the production of paper sizing agent raw materials. Therefore, unlike the production of conventionally used neutral sizing agent raw material olefins, in the production of linear internal olefins in the present invention, due to the unique performance of the catalyst used, a disproportionation process is not required. Not only can olefins with a double bond distribution clearly distinguishable from olefins be easily obtained, but also α-olefins can be completely converted into internal olefins with almost no polymerization.

Therefore, the sizing agent of the present invention made from a linear internal olefin or a mixture thereof has extremely superior emulsification and post-emulsification stability compared to sizing agents made from conventional olefins. , which not only shows an excellent size effect, but also can significantly improve the occurrence of stains in the papermaking system.

The linear internal olefin or mixture thereof used in the present invention is a linear α-olefin having a single carbon number or two or more carbon atoms in the range of 16 to 20 carbon atoms, or a mixture thereof. Obtained by isomerization using a catalyst. When the number of carbon atoms is 15 or less, not only the effect of the resulting sizing agent is insufficient, but also a polymer is likely to be formed during isomerization, and when the number of carbon atoms is 21 or more, unused particles are formed after the reaction with maleic acid. It is difficult to completely remove the reacted oil, and unreacted oil remains in the maleic acid adduct.
In either case, the stability after emulsification deteriorates.

Further, the ratio of double bond positions in the linear internal olefin or mixture thereof used in the present invention is 2-position, 3-position, and 4-position.
35 mol% or less, preferably 30 mol% or less, and the total amount is 55 mol% or more and less than 70 mol%.

If the total amount of the 2nd, 3rd, and 4th positions is less than 55 mol %, a polymer is likely to be formed in the isomerization of α-olefin, whereas if it is 70 mol % or more, the size effect will be poor.

Specific examples of organic acid salts of Group I transition metals of the Periodic Table or complexes of Group τ transition metals of the Periodic Table, which are used as component (A) of the isomerization catalyst in the present invention, include nickel octoate, Nickel naphthenate, nickel acetate, nickel lactate, iron malonate, iron acetylacetonate, cobalt benzoate, cobalt stearate, π-allyl nickel, nickel dimethylglyoxime, kotsukeru carbonyl, iron carbonyl, cobalt carbonyl, etc. However, it is preferable to use ninkel as the metal because it has the highest isomerization ability and produces less polymers.

Specific examples of organoaluminum compounds used as the component (B) of the α-olefin isomerization catalyst in the present invention include triethylaluminum, diethylaluminum chloride, triethylaluminum sesquichloride, ethylaluminum dichloride, etc. Examples include homologues in which chlorine is substituted with fluorine, bromine, iodine, etc., and homologs in which ethyl group is substituted with an alkyl group such as methyl group or propyl group.

In addition, in the isomerization reaction of α-olefin in the present invention, in addition to the isomerization catalyst components (A) and (B), other catalyst components such as a phosphine compound may be added to improve the catalytic activity. is also possible.

The amount of component (A) used in the isomerization reaction is not particularly limited, but the molar concentration of metal relative to α-olefin is preferably 0.1 to 50,000 pPm, more preferably 1 to 5,0 OOPpff10'). You can choose as appropriate.

In addition, the amount of isomerization catalyst W (B) component used was
) is preferably used in an amount of at least 0.5 times the number of moles of the metal in the component.

Since the isomerization catalyst used in the present invention has extremely high isomerization activity, reaction conditions can be selected from a wide range of reaction temperature -50°C to 200°C and reaction time 10 minutes to 10 hours. In order to suppress the reaction, it is preferable to carry out the reaction in the range of 0 to 80°C.

The isomerization reaction can be carried out in a batch method, a semi-patch method, a continuous method, or the like. Note that the isomerization reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon, and it is preferable to avoid mixing in large amounts of air or moisture.

In addition, the α-olefin isomerization reaction in the present invention is carried out using a very small amount of catalyst and under mild temperature conditions, so unlike the production of internal olefins using conventional acid catalysts, α-olefins are completely removed. Even when converted to internal olefins, polymers of dimers or higher are hardly produced, and linear internal olefins are obtained which are most suitable as raw materials for sizing agents.

Incidentally, since the amount of the dimer and other polymers produced as a by-product during the isomerization of the present invention is usually 1% by weight or less, it is natural that it is not necessary to remove this when used as a raw material for a sizing agent.

The addition reaction product of a linear internal olefin or a mixture thereof and maleic anhydride in the present invention is obtained by combining both without a catalyst, preferably under an inert atmosphere such as nitrogen gas, under normal pressure or increased pressure. It is obtained by heating to ~25 Q'O and reacting at that temperature for 1 to 30 hours, preferably 3 to 20 hours. The molar ratio of the two to be charged is not particularly limited, but it is desirable to use 5 to 3 moles of anhydrous maleic MO per 1 mole of linear internal olefin. After the reaction is completed, the unreacted linear internal olefin and maleic anhydride are removed by radical distillation, resulting in the reaction product of the present invention,
That is, a maleic anhydride addition reaction product having a relatively low viscosity is obtained.

Note that some by-products may be produced depending on the reaction conditions. In that case, the by-product can be removed as a distillation residue by further distillation under reduced pressure, but since the amount is small, removal of the by-product is not necessarily necessary in the present invention.

[Function] When sizing pulp using the papermaking sizing agent of the present invention containing the addition reaction product of the linear internal olefin and maleic anhydride obtained as described above, this size is usually used. This is done by adding the agent to the paper stock as an emulsion in which the agent is uniformly dispersed in water.

In order to improve dispersion in water, various emulsifiers such as polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene sorbitol fatty acid ester, polyoxyalkylene alkyl ether, polyoxyalkylene alkylaryl ether, fatty acid ester of polyhydric alcohol are used. , sulfuric ester salts of polyoxyalkylene alkyl ethers, etc., and various cationic compounds such as cationized starch, cationic polyacrylamide, etc. can be used together as Qi-forming agents.

The amount of emulsifier used in combination with the maleic anhydride addition reaction product of the present invention is determined by taking into account the type of emulsification equipment and dispersibility, etc. The amount is preferably 1 to 30% by weight, more preferably 3 to 20% by weight based on the reaction product.

Further, when a cationic compound is used as a suspending agent, the amount used is usually 30 to 600%, more preferably 100 to 300%, based on the addition reaction product of a linear internal olefin and maleic anhydride. %.

The method of emulsifying the i.1 addition reaction product of the linear internal olefin and maleic anhydride of the present invention in water is as follows: (1) Uniformly mixing the maleic anhydride addition reaction product and an emulsifier; A method of obtaining an emulsion by dispersing a mixture in water (2) A method of obtaining an emulsion by dispersing an emulsifier and/or a suspending agent in water and then adding a maleic anhydride addition reaction product. Both methods are possible, but among them (
The method 1) is preferred because it is the simplest, a good emulsion can be obtained with a small amount of emulsifier, and an excellent size effect can be obtained.

The emulsified sizing agent of the Sanki invention can be added to the pulp slurry at any step of the papermaking process.

The amount of the sizing agent of the present invention depends on the type of pulp used,
Although it varies depending on the paper-making conditions and the use of the paper, it is usually preferable to use 0.05 to 3.0% by weight based on the dry weight of the pulp.

In addition, in order to fix the sizing agent of the present invention to pulp, cationic compounds such as cationized starch, cationic polyacrylamide, polyamine polyamide epichlorohydrin resin, etc. are usually used as a fixing agent, but the amount used is limited to the pulp. It is preferably o, oi to 5.0%, more preferably 0.03 to 3.0%, based on the dry weight. Any of these fixing agents can be added at the same time, before or after the addition of the sizing agent. However, it is preferably added after the sizing agent for optimum fixing effect.

Note that the sizing agent of the present invention can be used in combination with various sizing agents other than the present invention in any ratio if desired, and when sizing, talc, clay, titanium oxide, calcium carbonate, Of course, all kinds of fillers can be used, such as calcium sulfate, aluminum hydroxide, etc.

As explained above, the sizing agent of the present invention uses a linear internal olefin that has a carbon number and double bond distribution within a specific range, does not contain any α-olefin, and contains almost no heavy components. As a result, it has extremely excellent emulsifying properties in water and stability after emulsification, and not only shows excellent size effects, but also can significantly improve the occurrence of stains in the papermaking system.

[Example 1] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples.

The double bond positions of the linear olefins in the following Examples and Comparative Examples were analyzed using C-N M R4.

That is, the chemical shifts of the carbon at the double bond position of the α-olefin are 114.2 ppm and 139. lppm,
124.5 ppm and 131.8 ppm for trans-2-olefins, 123, 13 ppm and 131.0 ppm for cis-2-olefins, and 129.5 ppm and 1 for trans-3-olefins.
32.0 ppm4 and 12 for cis 3-olefins.
9, 4ppm and 131.6ppm, trans 4
- 130.2 ppm and 130.2 ppm for olefins.
7ppm, and 129.7p for cis-4-olefin.
pm and 130.2 ppffl, trans olefins at the 5th or higher position appear at 130.5ppm, and cis olefins at the 5th or higher position appear at 130.0pP16. Based on the intensity ratio of these chemical shifts, the 1st, 2nd, 3rd,
The composition of an olefin having double bonds at the 4- and 5-positions can be determined.

Example 1 48 ml of n-hexadecene-1 was added to a glass flask.
8g, nickel octoate 0. θIg was charged with 1,500 ppm molar concentration of nickel relative to olefins, and after exchanging the argon head, 2.25 g of triethylaluminum sesquichloride (3 times the mole relative to nickel) was added under stirring, and the mixture was reacted at 30°C for 2 hours.

Next, the catalyst was decomposed with IN aqueous sodium hydroxide solution,
Removed. When the polymer in the reaction solution was analyzed by gas chromatography, it was found to be 0.5% by weight. The composition of n-hexadecene determined by C-NMR was as shown in Table 1.

Table 1 350 g of this n-hexadecene (containing 0.5% by weight of polymer) and 145 g of maleic anhydride were heated to 215° C. in a nitrogen gas atmosphere in an autoclave, and reacted without a catalyst for 8 hours. Unreacted olefin and maleic anhydride were removed from the reaction solution by vacuum distillation to obtain 374 g of a maleic anhydride addition reaction product.

Example 2 α having 16 to 18 carbon atoms obtained by polymerization of ethylene
-Olefin (carbon number 18: 57% by weight, carbon number 1
8: 43% by weight) 472g, nickel octoate 0.81g and nickel molar concentration of olefin 1.50
Example 1
The reaction was carried out at 30°C for 3 hours in the same manner as above, and the catalyst was decomposed and removed.

The polymer content in the resulting reaction solution was 0.5% by weight, and the composition of the olefin having 16 to 18 carbon atoms was as shown in Table 2.

Table 2 368 g of linear internal olefin (containing 0.5% by weight of polymer) obtained! 1: 145 g of maleic anhydride was reacted under the same conditions as in Example 1, and unreacted substances were removed to obtain 388 g of a maleic anhydride addition reaction product.

Example 3 α-olefin 4 having 16 to 18 carbon atoms used in Example 2
72 g of nickel octoate, 0.30 g of nickel octoate, 740 PPI11) of nickel to olefin molar concentration, and 2.20 g of triethylaluminum sesquichloride (6 times the mole of nickel) were heated at 30°C in the same manner as in Example 1.
The reaction was carried out for 8 hours, and the catalyst was decomposed and removed.

The polymer content in the obtained reaction solution was 0.3% by weight, and the composition of the olefin having 16 to 18 carbon atoms was as shown in Table 3.

Table 3 389 g of the obtained linear internal olefin (containing 0.3% by weight of polymer) and 145 g of maleic anhydride were reacted under the same conditions as in Example 1, unreacted substances were removed, and maleic anhydride 387 g of acid addition reaction product was obtained.

Comparative example l 350g of n-hexadecene-1 and maleic anhydride 14
5 g was reacted at 215° C. for 5 hours in the same manner as in the example, and unreacted substances were removed to obtain 376 g of anhydrous maleic reaction product.

Comparative Example 2 Filled with 150 mJlj of synthetic silica alumina, I 4
Example 2 was placed in a flow-type stainless steel reaction tube maintained at 0.000
450m of α-olefin with 16 to 18 carbon atoms used in
Oil was passed at a flow rate of M/h.

The polymer content in the obtained reaction solution was 3% by weight, and the number of carbon atoms was 1.
The compositions of the olefins having numbers 6 to 18 were as shown in Table 4.

Table 4 Comparative Example 3 n-hexadecane with hydrogen, rPte Li0z
・Supplied to a stainless steel reactor filled with Al103j catalyst, reaction temperature 480°C, flow rate 50 m/min,
The dehydrogenation reaction was carried out under the conditions of hydrogen/n-hexadecane = 10.0 (molar ratio). The composition of the n-hexadecene olefin obtained by treating this reaction solution with a molecular sieve was as shown in Table 5.

Table 5 350 g of this olefin and 145 g of maleic anhydride were reacted under the same conditions as in Example 1, and unreacted substances were removed to obtain 383 g of a maleic anhydride addition reaction product.

Comparative Example 4 Same as Example 1, using 488 g of n-hexadecene-■, 0.012 g of nickel octoate, 30 ppm molar concentration of nickel to olefin), and 0.59 g of triethylaluminum sesquichloride (40 times the molar amount to nickel). The reaction was carried out at 30°C for 5 hours, and the catalyst was decomposed and removed.

The polymer in the obtained reaction solution was 0.3% by weight, and n-
The composition of hexadecene was as shown in Table 6.

n-hexadecene in the table (containing 0.3% by weight of polymer)
350 g of maleic anhydride were reacted with 145 g of maleic anhydride under the same conditions as in Example 1, and unreacted substances were removed to obtain 479 g of a maleic anhydride addition reaction product.

Comparative Example 5 α-olefin having 16 to 18 carbon atoms used in Example 2 (
Carbon number: 18: 57% by weight, Carbon number: 18: 43% by weight
) 472 g, nickel octoate 0.03 g, nickel to olefin molar concentration 74 ppm), ) ethylaluminum sesquichloride 0.82 g (25 times the nickel mole) were used, and 30 g was prepared in the same manner as in Example 1.
The reaction was carried out at ℃ for 3 hours, and the catalyst was decomposed and removed.

The polymer content in the obtained reaction solution was 0.4% by weight, and the composition of the olefin having 16 to 18 carbon atoms was as shown in Table 7.

Table 7 389 g of the obtained linear internal olefin (containing 0.4% by weight of polymer) and 145 g of maleic anhydride were reacted under the same conditions as in Example 1, and unreacted substances were removed. 382 g of acid addition reaction product was obtained.

Comparative Example 6 α-olefin having 16 to 18 carbon atoms used in Example 2 (
Carbon number: 16: 57% by weight, carbon number: 18: 43% by weight
), 472 g of nickel octoate, 0.61 g of nickel octoate, 1,500 ppm molar concentration of nickel to olefin), and 2.25 g of triethylaluminum sesquichloride (3 times the mole of nickel), and heated at 30° in the same manner as in Example 1.
C. for 1.5 hours, and the catalyst was decomposed and removed.

The amount of polymer in the obtained reaction solution was 0.4% by weight, and the composition of the olefin having 16 to 18 carbon atoms was as shown in Table 8.

Table 8 369 g of the obtained linear internal olefin (containing 0.4% polymerization) and 145 g of maleic anhydride were reacted under the same conditions as in Example 1, unreacted materials were removed, and anhydrous 388 g of maleic acid addition reaction product was obtained.

Comparative Example 7 α-olefin having 16 to 18 carbon atoms used in Example 2 (
Carbon number: 18: 57% by weight, Carbon number: 18: 43% by weight
), 0.81 g of nickel octoate, molar concentration of nickel to olefin (1,500 ppm), and 2.25 g of triethylaluminum sesquichloride (3 times the mole of nickel) to prepare 3Q' in the same manner as in Example 1.
The reaction was carried out at 0 for 7 hours, and the catalyst was decomposed and removed.

The amount of polymer in the obtained reaction solution was 0.6% by weight, and the composition of the olefin having 16 to 18 carbon atoms was as shown in Table 9.

Table 9 Obtained linear internal olefin (containing 0.6% by weight of polymer) 3f (9 g and 145 g of maleic anhydride were reacted under the same conditions as in Example 1, and unreacted materials were removed. 385 g of maleic anhydride addition reaction product was obtained.

Example 4 A sizing test was conducted on the maleic anhydride addition reaction products obtained in Examples 1 to 3 and Comparative Examples 1 to 7. The test method is as follows.

Polyoxyethylene nonylphenyl ether (HLB 1) was added as an emulsifier to 10 g of the maleic anhydride addition reaction product.
3) After adding 0.5 g and mixing well, 89 g of water was added to 1 g of this mixture and emulsified with a homomixer to obtain a sizing agent emulsion. The obtained emulsion was mixed into a 1% pulp slurry (L, B, KP, 430 mu c, s, F) with a di-maleic anhydride addition reaction product of 0.1, 0.15 or 0.
．． After adding 0.8% by weight (based on pulp solids) of cationized starch while stirring, the amount is 2% by weight (based on pulp solids).
, 0.03% by weight (based on pulp solid content) of cationic polyacrylamide was added, and paper was made using a conventional IJ TAPPI standard sheet machine.

The filler used was heavy calcium carbonate, and the amount used was 20% by weight (based on the solid content of the pulp).

Next, the obtained wet paper was compressed and dehydrated, and dried in a rotary dryer for 1
The sample was dried by heating at 05°C for 3 minutes, and the humidity was controlled indoors at 20°C and relative humidity of 65% for 24 hours. The basis weight of the obtained handmade paper after humidity conditioning is equivalent to 65 g/d. The sizing of this handmade paper was measured by the Stekicht sizing test method of JIS P 8122. Further, after the prepared sizing agent emulsion was left to stand for 5 hours, hand-formed paper was prepared using the same in the same manner as above, and the degree of sizing was measured.

These results are shown in Table 10.

Table 10 As is clear from the results in Table 10, the sizing agent of the present invention not only has superior sizing effect compared to the sizing agent of the comparative example, but also has extremely good stability after emulsification, and There is little decrease in size even if left for a long time.

[Effects of the Invention] As explained below, the present invention exhibits the following excellent effects.

The sizing agent of the present invention uses a linear internal olefin obtained by isomerizing a linear α-olefin with a limited carbon number range as a raw material using a specific catalyst, and this internal olefin has limited double bonds. It has excellent emulsifying properties and stability after emulsification, as it has no α-olefin and has an extremely low polymer content, and not only has excellent size effects, but also has excellent resistance to stains in paper making systems. can improve the occurrence of

Claims (2)

[Claims] (1) Using a catalyst consisting of (A) an organic acid salt of a Group VIII transition metal of the Periodic Table or a complex of a Group VIII transition metal of the Periodic Table and (B) an organoaluminum compound,
A linear internal olefin containing no α-olefin or a mixture thereof obtained by isomerizing a linear α-olefin having 20 or a mixture thereof, which has double bonds at the 2-, 3- and 4-positions. By an addition reaction between maleic anhydride and a linear internal olefin having 16 to 20 carbon atoms or a mixture thereof, in which the proportion of olefins is 35 mol% or less, and the total is 55 mol% or more and less than 70 mol%. A paper sizing agent containing the resulting reaction product. (2) The paper sizing agent according to claim 1, wherein the Group VIII transition metal of the periodic table is nickel.