JPH0154478B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel and useful reactive sizing agents based on substituted succinic anhydrides that can be used effectively in both neutral and alkaline conditions. More specifically, the present invention can produce paper that absorbs less water and ink and has greater resistance to acid and alkaline aqueous solutions. The present invention relates to a sizing agent that is also fully miscible with various fillers, pigments, and other chemicals. Currently, anionic sizing agents such as rosin-based sizing agents, which are most commonly used, are fixed to the pulp on the acidic side by sulfuric acid bands, so they have various drawbacks such as printing effects and paper strength. Therefore, there has been a desire to develop a sizing agent that can be used to make paper in the neutral range, and various suitable sizing agents have been developed, but none have yet been found that are fully satisfactory. Among the sizing agents that can be used to make paper in this neutral region are "reactive sizing agents," such as those based on alkyl ketene dimers or alkenyl succinic anhydrides. also has some drawbacks. That is, alkyl ketene dimers require advanced technology to synthesize and are therefore expensive as sizing agents.Although they have excellent chemical stability after emulsification in water, on the other hand, the reaction rate with cellulose fibers is extremely slow. It's late. On the other hand, sizing agents based on alkenylsuccinic anhydride have a high reaction rate with cellulose fibers, contrary to alkyl ketene dimers, but have poor chemical stability after emulsification in water (generally, sizing agents based on succinic anhydride The period is
It is said to take about 30 minutes). Moreover, it is an oily material, and strict conditions are imposed on it to emulsify it during use, and it must be used immediately after emulsification, requiring an expensive emulsifying device in the paper making machine. On the other hand, maleic anhydrides of alkyl oleates, such as the maleic anhydride of n-octyl oleate disclosed in Japanese Patent Application Publication No. 1987-38902, can be emulsified more easily than alkenylsuccinic anhydrides.
The chemical stability of the emulsion is also relatively good, and the reaction rate with cellulose fibers is also very satisfactory, making it a noteworthy compound. but,
There are some problems with ease of emulsification, raw material cost, size, etc. That is, in order for this type of sizing agent to surpass the existing rosin-based sizing agents, in addition to the extremely superior sizing degree, the difficulty of emulsification and the price are considered to be major factors. The object of the present invention is to avoid the above-mentioned drawbacks of alkyl ketene dimers and alkenyl succinic anhydrides, and to achieve various physical properties (size, emulsification, The purpose of the present invention is to provide a sizing agent that surpasses the difficulty level of In other words, it is possible to easily produce an emulsion that is chemically stable for a long time, requires only ordinary emulsification equipment, requires minimal special equipment and skilled workers, and uses easily available and inexpensive raw materials. The purpose of the present invention is to provide a reaction product that is compatible with conventional sizing agents and has sufficient compatibility with conventional sizing agents. The paper sizing agent of the present invention is made by reacting maleic anhydride with an unsaturated carboxylic acid diester corresponding to the general formula below while minimizing the formation of polymers, and converting at least one reaction product into an aqueous solution. General formula for emulsification: (In the formula, R ₁ is the formula -(A-O) _o A-, (However, A is
The compound HO-A-OH is ethylene glycol,
selected from the group consisting of propylene glycol, butanediol, neopentyl glycol, and bisphenol A, where n is a number from 0 to 2;
When the compound HO-A-OH is butanediol, neopentyl glycol or bisphenol A, a divalent group represented by n=0), R ₂ , R ₃
One is an unsaturated carboxylic acid residue having 10 to 22 carbon atoms, and the other is an unsaturated or saturated carboxylic acid residue having 10 to 22 carbon atoms). The fatty acids (R ₂ and R ₃ ) containing an unsaturated carboxylic acid having 10 to 22 carbon atoms constituting the unsaturated carboxylic acid diester of the present invention include beef tallow, fish oil, tung oil,
Fatty acids include olive oil, castor oil, tall oil, and cottonseed oil (which also contain 10 to 22 saturated carboxylic acids), but preferably those with a high content of oleic acid or linoleic acid. Above HO-A
-OH compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, neopentyl glycol, and bisphenol A, but there are ether bonds and ester bonds in glycol. The hydrophobicity of the diester decreases accordingly, and the degree of size also decreases accordingly, so ethylene glycol, propylene glycol, and butanediol neopentyl glycol are preferred. In the present invention, the reaction between the ester and maleic anhydride can be carried out by any conventionally known method, but according to one embodiment of the present invention, maleic anhydride and a diester having the above structure are reacted with hydroquinone under atmospheric pressure. The reaction is carried out at 180-220°C. The reaction ratio (molar ratio) of maleic anhydride/diester is about 0.5 to 6.0, and the optimum value varies depending on the structure of the diester and the degree of unsaturation of the fatty acid, but for example, ethylene glycol of an unsaturated fatty acid with an iodine value of about 100. For esters, good sizing can be obtained when the value is 3.0 to 4.0. A small amount of unreacted maleic anhydride has little effect on the sizing degree, so it may be used as it is as a sizing agent, but it is preferably removed.
Examples of the removal method include a method of removing by distillation, and a method of reacting with a second reaction raw material that easily produces an adduct by reaction and mixing this adduct into the emulsion. Here, the second reaction raw material is preferably one that has a conjugated double bond and that its maleic anhydride adduct does not have a negative effect on the sizing degree. The sizing agent of the present invention is preferably used in combination with a cationizing agent, and effective cationic agents include polymeric cationic activators such as cationized starch and cationized cellulose. The novel reactive sizing agent of the present invention does not require special emulsification conditions compared to alkenylsuccinic anhydrides, and the chemical stability of its emulsion is much longer than the lifetime estimated from its structure. It also does not have the disadvantages of slow reactivity towards cellulose fibers found in ketene dimers. Therefore, switching from the currently commonly used anionic sizing agent to the new sizing agent can be performed extremely easily. In addition, the paper produced using the new sizing agent has a significantly higher sizing degree than that produced using the anionic sizing agent, and exhibits excellent resistance to acidic and alkaline aqueous solutions. It has the advantage of being less affected by paper manufacturing conditions such as water temperature. Furthermore, compared to the reaction product of n-octyl oleate and maleic anhydride, it is easier to emulsify and has the same or higher size, minimizing the use of petroleum-based raw materials whose prices and supplies are unstable, and using mainly natural Since animal and plant materials can be used, it can be produced at low cost. The present invention will be specifically explained below with reference to Examples and Comparative Examples. Example 1 4 moles of maleic anhydride were added to 1 mole of ethylene glycol diester of slightly hydrogenated fish oil fatty acid (iodine value 98) under a hydroquinone catalyst of 0.1% by weight.
After reacting for 6 hours at atmospheric pressure and a temperature of 200 to 220°C, unreacted maleic anhydride was removed by distillation under reduced pressure (200°C, 10 mmHg). The resulting product is dark in color and contains a significant amount of polymer. This product was used directly as a sizing agent. Example 2 A maleic anhydride was synthesized in the same manner as in Example 1 except that dipropylene glycol diester was used instead of ethylene glycol diester. Example 3 A maleic anhydride was synthesized in the same manner as in Example 1 except that neopentyl glycol diester was used instead of ethylene glycol diester. Example 4 A maleic anhydride was synthesized in the same manner as in Example 1 except that 1,4-butanediol diester was used instead of ethylene glycol diester. Example 5 A maleic anhydride was synthesized in the same manner as in Example 1 except that bisphenol A diester was used instead of ethylene glycol diester. Example 6 A maleic anhydride was synthesized in the same manner as in Example 1 except that tripropylene glycol diester was used instead of ethylene glycol diester. Example 7 A maleic anhydride was synthesized in the same manner as in Example 1 except that ethylene glycol dioleate was used instead of the ethylene glycol diester of slightly hydrogenated fish oil fatty acid. Comparative Example 1 0.2% by weight of hydroquinone was added as a catalyst to 1 mol of methyl oleate and 2 mol of maleic anhydride, and after reacting for 9 hours at a temperature of 200 to 220°C under atmospheric pressure, as in Example 1, A composition obtained by vacuum distillation (200° C., 10 mmHg) of maleic anhydride in the reaction was used as it was as a sizing agent. Comparative Example 2 In Comparative Example 1, n instead of methyl oleate
A maleic anhydride was synthesized using octyl oleate in the same manner as in Example 1. Next, sized paper was made using the new sizing agent shown in the example, the sizing agent of the comparative example, and a commercially available rosin-based sizing agent, and the sizing effects were compared. The sizing agent used in the Examples and Comparative Examples was commercially available cationized cellulose with a ratio of 25% to the sizing agent.
Emulsions were emulsified for 10 minutes using % by weight, and then allowed to stand for 30 minutes. 0.2, 0.5, and 1.0% by weight of each emulsion were added to a 1% pulp aqueous solution, and after stirring for 5 minutes, papermaking was carried out. In the case of a rosin-based sizing agent, a certain amount was added to a 1% pulp aqueous solution, the pH was adjusted to 4.5 with a sulfuric acid band, and papermaking was performed after fixing.

【table】

[Table] From the table, the new sizing agent of the present invention not only has a significantly superior sizing degree compared to commercially available rosin-based sizing agents, but also in Examples 1, 3, 4, and 5, in which the glycol does not contain an ether bond. Comparative Example 2 of n-octyl oleate maleic anhydride
It can be seen that there is a difference in sizing degree, especially when the amount of sizing agent used is small. The new sizing agent does not reduce the sizing degree much, whereas the comparison example and the rosin-based sizing agent significantly reduce the sizing degree. .

Claims (1)

[Claims] 1. A sizing agent for paper manufacturing containing as an active ingredient at least one compound obtained by the reaction of maleic anhydride and an unsaturated carboxylic acid diester corresponding to the following general formula: (In the formula, R ₁ is the formula -(A-O) _o A-, (However, A is
The compound HO-A-OH is ethylene glycol,
selected from the group consisting of propylene glycol, butanediol, neopentyl glycol, and bisphenol A, where n is a number from 0 to 2;
When the compound HO-A-OH is butanediol, neopentyl glycol or bisphenol A, a divalent group represented by n=0), R ₂ , R ₃
One is an unsaturated carboxylic acid residue having 10 to 22 carbon atoms, and the other is an unsaturated or saturated carboxylic acid residue having 10 to 22 carbon atoms).