JPH0135116B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oil-proofing agent for paper, and more specifically to a novel oil-proofing agent for paper comprising a reaction product of a perfluoroalkyl phosphate ester and a specific water-soluble polymer compound such as polyethyleneimine. Conventionally, oil-proofing agents for paper made of perfluoroalkyl phosphate esters have been widely known. For example, see Japanese Patent Publication No. 48-4770, Japanese Patent Publication No. 56-29875, etc. However, such conventional phosphate ester type oil resistance agents are generally used for internal addition treatment, and external addition treatment has not been able to impart sufficient oil resistance to paper. That is, although an effect was observed in the internal addition process in which paper is made by adding and mixing an oil resistant agent to pulp, a sufficient effect was not observed in an external addition process in which paper made from pulp is impregnated with an oil resistant agent. In the conventional internal addition treatment using a phosphate ester type oil-proofing agent, it is usually necessary to use various fixing agents together, and the applicability to low-grade pulp such as deinked newspaper waste and unbleached pulp is limited. There are some drawbacks, and there is also the drawback that oil resistance decreases when a sizing agent is present. The present inventor has developed various methods for treating paper by reacting a perfluoroalkyl phosphate ester with a water-soluble polymer compound having a reactive NH group such as polyethyleneimine and using the resulting reaction product for oil-proofing paper. We have discovered that the difficulties can be resolved. That is, the oil resistance agent made of the reaction product has excellent effects not only in internal addition treatment but also in external addition treatment. Furthermore, it is not necessarily necessary to use a fixing agent in the internal addition treatment, which increases applicability to low-grade pulp and improves workability.
Of course, it is also possible to use a fixing agent in combination, and it is also possible to further improve the performance by using a small amount of the fixing agent. Further, in the external addition treatment, it is possible to impart sufficient oil resistance, and the resulting oil-resistant treated paper has the advantage of being excellent in suitability for gravure printing. Thus, the present invention was completed based on the above findings, and consists of a phosphate ester having a perfluoroalkyl group having 4 to 16 carbon atoms and an OH group, and a water-soluble polymer compound having a reactive NH group. The purpose of the present invention is to provide a new oil-proofing agent for paper made of a reaction product of The oil-resistant agent of the present invention is usually prepared in water by a phosphoric acid ester having a perfluoroalkyl group (hereinafter referred to as FP).
(hereinafter abbreviated as AP) and a specific water-soluble polymer compound such as polyethyleneimine (hereinafter abbreviated as AP). In this case, the reaction product is obtained in the form of an aqueous dispersion. and,
Such aqueous dispersions have excellent chemical stability;
It has the advantage that it is not easily affected by contaminant ions, the dispersed state is not destroyed, and scum does not occur. In addition, it has high mechanical stability, and the dispersed state will not be destroyed even when subjected to mechanical shock such as liquid dropping, stirring, or shearing. Furthermore, it has excellent freezing stability, and even after repeated freezing and thawing, the dispersion state is not impaired, and oil resistance is not affected. Therefore, in the present invention, the FP is usually a general formula

A phosphoric acid ester represented by the formula is used. R _f has 4 to 16 carbon atoms,
In particular, it is represented by 6 to 12 perfluoroalkyl groups (CnF _2o+1 ), and n is 4 to 16, especially 6 to
R is an integer of 12), R has 1 to 4 carbon atoms, especially 1
-2 divalent alkylene groups (represented by -C _n H _2n -, where m is an integer of 1 to 4, particularly 1 to 2). R _f and R may be linear or branched. Alternatively, a mixture of R _f having different carbon numbers may be used. When x is 2, the oil resistance effect is higher than when x is 1, so when used as a mixture, it is desirable to use one with an average value of x of 1.5 or more. When x is 3, there is no reactivity with AP, but since it only has a diluting effect, x as a mixture
Those with an average value of 2 or more to 2.5 can be adopted. Therefore, in the present invention, x has an average value of 1 to
2.5 can be adopted. In the present invention, APs having various molecular weights can be used, but usually 10,000 to 10,000 to 10,000
A molecular weight of approximately 30,000 to 50,000 is particularly preferable. A typical preferred example of AP is polyethyleneimine (hereinafter abbreviated as PEI), but in the present invention, any water-soluble polymer compound having a reactive NH group that can react with the OH group of FP can be used. , and various other types may be adopted. The content of NH groups in AP can be varied over a wide range of about 1 to 40 parts by weight per 100 parts by weight of AP. Specific examples of AP include, in addition to the PEI, polypropylene imine, cationic polyacrylamide, chitosan, a copolymer of diethylenetriamine and adipic acid, and a copolymer of methyl acrylate and diethylenetriamine. The oil resistance agent of the present invention is composed of a reaction product of FP and AP, and as described above, is usually synthesized by reacting the two in water. For example, it can be obtained in the form of an aqueous dispersion by adding FP powder or FP melt to an AP aqueous solution and reacting AP and FP while stirring. Since FP and the reaction product have self-emulsifying properties, the aqueous dispersion is in the form of an emulsion. The reaction temperature in this case is selected from the range of room temperature to about 150°C, but at too low a temperature the reaction will be slow and it will take a long time to complete the reaction, and at too high a temperature the reaction will be rapid and the produced latex particles will not coalesce. occurs,
The tendency for precipitation to form as a by-product increases. Furthermore, if the reaction temperature is low, the viscosity of the produced latex will be high, which will be disadvantageous in terms of workability during oil-proofing treatment. In the present invention, 80~
A reaction temperature of about 130°C is suitable, especially 100°C to
Approximately 120℃ is desirable. In the present invention, the reaction ratio of FP and AP can be adopted over a wide range, but if the ratio of AP is too low, the product will not be completely emulsified, and the tendency to produce a precipitate will increase. Further, although it is possible to increase the proportion of AP, if it is too large, oil resistance will be disadvantageous. Usually, the weight ratio of AP/FP is 0.5/1 to 2/1, preferably 0.8/1 to
A reaction ratio of 1.5/1 may be adopted. The oil resistance agent of the present invention is preferably obtained in the form of an aqueous dispersion (emulsion) as described above, and the concentration of the specific reaction product is usually 5 to 40% by weight, particularly 10 to 30% by weight. It is desirable to synthesize the Of course,
It is also possible to suitably dilute the emulsion when used in the oil-proofing treatment of paper. As mentioned above, the oil-resistant agent of the present invention can be used for both internal addition treatment and external addition treatment, and can be adjusted to an appropriate concentration for each. That is, in the internal addition method of adding to the pulp during papermaking, it is desirable to use an emulsion diluted to a specific reaction product concentration of 0.1 to 5% by weight. In this method, it is preferable to use an emulsion diluted to a reaction product concentration of 0.05 to 5% by weight. The oil-resistant agent in the form of an emulsion of the present invention can be made to have low foaming properties by adding phosphoric acid. That is, an aqueous phosphoric acid solution is added to and mixed with the FP/AP reactant emulsion. The amount of phosphoric acid added is
5 to 100 parts by weight of FP/AP reactant solid content
It can be selected from a range of about 40 parts by weight, preferably about 10 to 30 parts by weight. The oil-resistant agent of the present invention is effectively used for oil-proofing paper and paperboard, and is widely applicable to, for example, wallpaper, paper bags, paper cartons, iron plate plywood, rust-proof paper, and the like. It is particularly effective for oil-proofing wrapping paper or wrapping paper containers for oil-based foods such as margarine, donuts, tyokolate, and dog food. Next, examples of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such description. In addition, various performance measurements in the following examples were carried out as follows. In addition, the proportions are by weight unless otherwise specified. The printing suitability test was carried out using the Printing Bureau type gravure printing test method for the foreign-added paper. The ink used was chlorinated rubber-based CPZ, and its printability was evaluated on the following five levels. 5: Good 4: Fairly good 3: Fair 2: Fairly poor 1: Poor Oil resistance was measured as follows. Place one drop of the test oil shown in Table 1 on the treated paper and observe the state of oil penetration after 15 seconds. The highest number that does not penetrate is considered the oil resistance of the treated paper. The higher the number, the better the oil resistance.

[Table] Example 1 Powdered fluorine-containing phosphate ester was placed in the pressure-resistant reaction vessel of 1.

[Formula] 63g, 210g of a 30% aqueous solution of polyethyleneimine (number average molecular weight 45,000), and 427g of ion-exchanged water were added and the container was sealed. The contents were reacted at 110° C. for 6 hours while stirring at 300 rpm. The product is a translucent emulsion with a viscosity of 410 cp and an average particle size of
It was 0.26 μm. This emulsion was diluted with water to prepare a treatment bath with a solid content concentration of 0.5% by weight, and unsized paper (basis weight 40 g/m ² ) was immersed in it using a size press at a speed that gave a squeezing rate of 50%. Processed. Then, dry it in a drum dryer heated to 80℃ for 15 minutes.
Dry for seconds. This processed paper treated with external additives showed an oil resistance level of 12. In addition, 0.72 g of a treatment liquid with a solid content concentration of 1.0 wt% was added to 40 g of bleached pulp (3 wt% aqueous dispersion).
After stirring for several minutes, paper was made using a standard hand skimmer according to JIS-P-8209. Wet paper was pressed between sheets of paper, and after thoroughly absorbing water, it was dried for 1 minute using a drum dryer heated to 100°C. This internally added processed paper showed an oil resistance of 12. Examples 2 to 4 Various reaction products were synthesized in the same manner as in Example 1, except that the reaction temperature was changed, and their oil resistance was measured. The results are shown in Table 2.

[Table] Examples 5 to 8 Various reactants were synthesized in the same manner as in Example 1, except that the reaction ratio of FP and PEI was changed, and their oil resistance was measured. The results are summarized in Table 3.

[Table] Example 9 The emulsion of Example 1 can be defoamed by adding phosphoric acid. Table 4 shows the relationship between the amount of phosphoric acid added and the foam height at an emulsion solid content of 1% by weight.

[Measurement method of foaming property]

1% up to 70mm on a colorimetric tube with a diameter of 24mm and a height of 215mm
Immediately after adding the emulsion and shaking for 1 minute, and 10 minutes later, the height of the foam was measured. Example 10 (Application to low-grade pulp) Using low-grade pulp, the reaction product of Example 1 was internally added. On the other hand, as a comparative example, commercially available fluorine-containing phosphate ester oil resistance agents A and B were fixed with an equal weight of polyethyleneimine (the solid content of the pulp was 0.6% as in Example 1) and added internally. Processed. Table 5 shows the oil resistance of the obtained processed paper.

[Table] It was found that this product exhibited superior performance compared to commercially available products. Example 11 (Suitability for gravure printing) The reaction products of Example 1, commercial product A, and commercial product B were externally added to bleached kraft paper so that the oil resistance was 5 and 10. Table 6 shows the results of measuring the suitability for gravure printing of the obtained oil-resistant treated paper.

[Table] It was found that the material exhibited excellent suitability for gravure printing.

Claims (1)

[Scope of Claims] 1. An oil-proofing agent for paper comprising a reaction product of a phosphoric acid ester having a perfluoroalkyl group having 4 to 16 carbon atoms and an OH group and a water-soluble polymer compound having a reactive NH group. 2 Phosphate ester has the general formula [Formula] (However, R _f is a perfluoroalkyl group having 4 to 16 carbon atoms, R is a divalent alkylene group having 1 to 4 carbon atoms, and X is an average value of 1 to 2.5 The oil-resistant agent according to claim 1, which is a compound represented by the following formula: 3. The oil-resistant agent according to claim 1, wherein the water-soluble polymer compound is polyethyleneimine having a molecular weight of 10,000 to 100,000. 4. The oil-resistant agent according to claim 1, wherein the reaction weight ratio of water-soluble polymer compound/phosphoric acid ester is 0.5/1 to 2/1.