JP5651859B2 - Fluorescence inhibitor and fluorescence suppression method - Google Patents

Description

  The present invention relates to a fluorescence inhibitor and a fluorescence suppression method for waste paper or waste paper pulp, and more particularly to a processing method for providing a fluorescence inhibitor that is highly effective even by an external addition method.

  In recent years, in the paper industry, there has been a tendency to increase the amount of used paper due to increased interest in resource protection and the environment. As the proportion of used paper increases, the quality of the paper tends to deteriorate due to the inclusion of many pulp fibers with short fiber length and weak strength. In addition, the amount of water used has been reduced due to environmental impact and cost, and the use of closed water has progressed. As a result, the internal size added during papermaking, such as increased white water electrical conductivity and increased anion trash, etc. It has become an environment in which internal additives such as chemicals are difficult to exert. Therefore, in place of internal additives with low yield, the amount of external additives with high yield is increasing more and more to compensate for the lack of effectiveness of internal agents.

  In the case of paper products that require whiteness, the whiteness is increased by using a fluorescent whitening agent in order to obtain whiteness. As a result, used white paper with high whiteness often contains fluorescent whitening agents.

  However, since it is not desirable to recycle food-related paper products that may come into direct contact with food, sanitary paper, heat-sensitive paper, and pressure-sensitive paper that may come into direct contact with recycled paper, these papers In the case of producing a virgin pulp, virgin pulp was used, or as a physical method, a very small amount of used paper containing a fluorescent brightening agent was used together to reduce the overall fluorescence intensity to a usable range. However, this method has a problem that it is difficult to completely erase the fluorescent color, the amount of use is limited, and it takes much time and effort.

  As a chemical method for suppressing fluorescence, Patent Document 1 discloses a method using sodium dichloroisocyanurate in used paper slurry, and Patent Document 2 describes a method using chlorine dioxide in used paper slurry. Patent Document 3 discloses a method of treating waste paper pulp with ozone. Patent Document 4 proposes a method for decomposing a fluorescent whitening agent in waste paper pulp with an enzyme.

  Patent Document 5 discloses a polyimidazoline compound or naphthaleneperidicarboxylic acid imide as a fluorescence inhibitor for fiber products, and Patent Document 6 discloses a hydrolyzate of an N-vinylformamide polymer.

Japanese Patent No. 3118087 Japanese Patent Publication No.8-19630 Japanese Patent Publication No.7-880 JP 2003-117469 A JP-A-4-289280 JP 2005-42270 A

  The chemical fluorescence inhibitor, dichloroisocyanurate sodium of Patent Document 1 and chlorine dioxide of Patent Document 2, are decomposed and a large amount of toxic chlorine gas is discharged into the air or waste water, which may cause environmental problems. The The method using ozone of Patent Document 3 requires an advanced apparatus, and requires a high level of balance between damage to the pulp and bleaching, and there are many economical and technical problems. In addition, the toxicity of ozone gas is also a problem. The method using the enzyme of Patent Document 4 requires special equipment and has insufficient performance, and is not suitable for producing inexpensive waste paper pulp.

  The hydrolyzate of the polyimidazoline compound, naphthaleneperidicarboxylic acid imide of Patent Document 5 and N-vinylformamide polymer of Patent Document 6 is effective in the internal addition method, but is an anionic drug in the external addition method. There is a problem in that the compatibility of the fluorescent light is poor and the fluorescence suppression effect is not sufficient. An object of the present invention is to provide a fluorescence inhibitor that is highly effective even in the external addition method under such circumstances.

（但し、式中Ｒ１、Ｒ２はＨ、ＣＨ_３またはＣ_２Ｈ_５であり、ＹはＣｌ⁻、Ｂｒ⁻、ＳＯ_４ ⁻⁻、ＣＨ_３ＳＯ^３−、ＮＯ_３ ⁻、又はＰＯ_４ ⁻⁻⁻ で表わされる陰イオンを示す。） In order to solve the above-mentioned problems, the present invention facilitates a paper with suppressed fluorescence by adding the following compound, general formula (1), to the recycle processing step of the fluorescent whitening agent-containing waste paper or waste paper pulp. Can be manufactured.

(However, wherein R1, R2 is H, CH ₃ or _C 2 _{H 5,} Y is ^{_{Cl -, Br -, SO 4}} -, CH 3 SO 3-, NO 3 -, or PO ₄ ^--- An anion represented by

  According to the present invention, it becomes possible to use hygienic paper and food packaging paper that do not particularly need to contain fluorescence without sorting used paper containing a fluorescent brightener and not used paper. It is also possible to apply waste paper pulp to raw materials such as general printing paper, paperboard and cardboard.

  The raw material of the used paper pulp to be treated by the method of the present invention is not particularly limited as long as it is a used paper containing a fluorescent brightening agent. For example, used newspaper, used paper, printed paper, used pigment-coated paper, magazines Examples include waste paper, cardboard waste paper, paperboard waste paper, and factory waste paper.

  Examples of the optical brightener include bis (triazinylaminostilbene) disulfonic acid derivatives, pyrazonin derivatives, coumarin derivatives, bisbenzoxalyl derivatives, bisstyryl biphenyl derivatives, etc., but bis (triazinylaminostilbene) Disulfonic acid derivatives dominate.

  Recycle processing of waste paper is carried out by various processes such as disaggregation, sorting, deinking, dust removal, washing, fine selection, bleaching, paper making, and surface treatment. The chemical used at the time of paper making is called an internal additive, and the chemical used at the surface treatment after paper making is called an external additive. The fluorescence inhibitor of the present invention is used in the external addition method performed in the surface treatment step among these steps.

  There are various treatment methods for the treatment agent in the external addition method, and examples thereof include 2-roll size press coating, gate roll coating, and rod metering size press coating.

  Examples of the compound of the general formula (1) used in the present invention include 1-benzylpyridinium salt, 2-methylbenzylpyridinium salt, 3-methylbenzylpyridinium salt, 4-methylbenzylpyridinium salt, 2-ethylbenzylpyridinium salt, 3-ethylbenzylpyridinium salt, 4-ethylbenzylpyridinium salt, 2,4-dimethylbenzylpyridinium salt, 2,6-dimethylbenzylpyridinium salt, 3,5-dimethylbenzylpyridinium salt, 2,4-diethylbenzylpyridinium salt, 3,5-diethylbenzylpyridinium salt and the like can be mentioned. These may be used alone or in combination. When the alkyl group becomes larger than the ethyl group, the effect becomes worse.

  These compounds of the present invention can be easily produced by reacting the corresponding pyridine derivative with benzyl halide. As the salt, chloride and bromide are often used for ease of production. The anionic counter ion can be easily changed by passing a strongly basic anion exchange resin or an ion exchange membrane.

  The amount of the compound represented by the general formula (1) is 0.05% to 10.0%, preferably 0.3% to 5.0%, based on the paper. If the amount used is less than this range, a sufficient fluorescence suppression effect is not exhibited, and even if it is used excessively, there will be no benefit if the cost is high.

  When processing paper pulp by the external addition method, a treatment solution is applied or sprayed at normal temperature to 50 ° C. under normal pressure to give a predetermined amount of fluorescence inhibitor, and then heated and dried at 100 ° C. to 180 ° C. .

  In the treatment liquid used in the present invention, as an optional component, a surface sizing agent, a surface paper strength agent, a surface processing agent, a chemical for information paper, an antistatic agent, a penetrating agent, an antifoaming agent, a crosslinking agent, a functional agent, Dyes, coloring pigments, and the like can be added as long as the object of the present invention is not impaired. Many of these external additives are anionic.

  Examples of the sizing agent include styrene maleic acid copolymer, styrene acrylic acid copolymer, olefin maleic acid copolymer, alkenyl succinic anhydride, alkyl ketene dimer, stearate chromic chloride, and rosin compound. Examples of surface paper strength agents include glue, gelatin, casein, starch, modified starch, starch derivatives, polyacrylamide, and polyvinyl alcohol. Examples of the surface finishing agent include paraffin emulsion, silicon resin, fluororesin, urea resin, latex and the like. Examples of chemicals for information paper include amine-based polymers, polyvinyl alcohol, polyester resins, maleic acetate copolymers, and polyvinyl acetate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Unless otherwise indicated, parts and% in the examples are parts by weight and% by weight.

Synthesis example 1
79.1 g of pyridine was added to a four-necked glass container equipped with a stirrer, a nitrogen gas inlet tube, and a thermometer, and 127 g of benzyl chloride was added through nitrogen gas, followed by reaction at 105 ° C. for 8 hours. Next, 382.7 g of water was added and reacted at 100 ° C. for 2 hours to obtain a yellow liquid of 1-benzylpyridinium chloride having a concentration of 34%.

Synthesis example 2
4-methylpyridine 93.1g was added to a four-necked glass container equipped with a stirrer, a nitrogen gas inlet tube, and a thermometer, and 127 g of benzyl chloride was added through nitrogen gas, followed by reaction at 105 ° C for 8 hours. Next, 408.7 g of water was added and reacted at 100 ° C. for 2 hours to obtain a tan liquid of 4-methylbenzylpyridinium chloride having a concentration of 34%.

Comparative Synthesis Example 1
To a four-necked glass vessel equipped with a stirrer, a nitrogen gas inlet tube, and a thermometer, 213 g of dimethyllaurylamine was added, 127 g of benzyl chloride was added through nitrogen gas, and the reaction was carried out at 105 ° C. for 8 hours. Next, 631 g of water was added and reacted at 100 ° C. for 2 hours to obtain a tan liquid of dimethyl lauryl benzyl ammonium chloride having a concentration of 34%.

Comparative Synthesis Example 2
166 g of terephthalic acid and 146 g of triethylenetetramine were added to a four-necked glass container equipped with a stirrer, a nitrogen gas introduction tube, a thermometer, and a dehydration tube, and a dehydration condensation reaction was performed at 250 ° C. for 8 hours through nitrogen gas. Next, 104 g of concentrated hydrochloric acid and 483 g of water were added to obtain a brown polyimidazoline derivative having a concentration of 34%.

Comparative Synthesis Example 3
To a four-necked glass container equipped with a stirrer, a nitrogen gas inlet tube, and a thermometer, 300 g of N-vinylformamide, 1.5 g of sodium hypophosphite, and 664 g of water are added, and 2,2-azobis is used as a catalyst through nitrogen gas. 4.5 g of (2-amidinopropane) hydrochloride was added and reacted at 70 ° C. for 8 hours to obtain a yellow polyvinylformamide solution having a concentration of 30%. 30 g of sodium hydroxide was added, the mixture was stirred at 70 ° C. for 7 hours, and the pH was adjusted to 4 with hydrochloric acid. A brown polyvinylformamide hydrolyzate having a concentration of 28% was obtained.

Example 1
Using virgin pulp consisting of 70% hardwood bleached kraft pulp (LBKP) and 30% softwood bleached kraft pulp (NBKP), 2% fluorescent whitening agent (Kayahor 3BS Liq .: manufactured by Nippon Kayaku Co., Ltd.) for paper Paper with a basis weight of 100 g / m ² was made with a tappi paper machine using a liquid consisting of 1% sizing agent (size pine E-50: manufactured by Arakawa Chemical Co., Ltd.) and 5% sulfuric acid band.

  Next, with a size press machine, the fluorescence inhibitor composed of the compound of Synthesis Example 1 is 0.5% solid, and the paper strength agent is oxidized starch (Oji Ace C: manufactured by Oji Cornstarch Co., Ltd.) 5.0% solid. An anionic styrene acrylic surface sizing agent (SE2018: manufactured by Seiko PMC) was applied by an external addition method so as to be 0.2% solids, and dried at 120 ° C.

The fluorescence intensity was determined by measuring the whiteness using a spectrocolorimeter CM-3600d (manufactured by Konica Minolta), and the fluorescence cut rate was calculated from the following formula. The fluorescence suppression effect was determined based on the fluorescence intensity and the fluorescence cut rate.

  The fluorescence intensity of the base paper when no fluorescence inhibitor was added was 47. The results are shown in Table-1. Table 1 also shows the compatibility of the coating liquid when mixing the fluorescence inhibitor, the paper strength agent and the surface sizing agent.

Example 2
Synthesis Example 1 The same procedure as in Example 1 was conducted except that the fluorescence inhibitor composed of the compound was applied to a solid content of 1.0%. The results are shown in Table-1.

Example 3
Synthesis Example 1 The same procedure as in Example 1 was conducted, except that the fluorescence inhibitor composed of the compound was applied to a solid content of 2.0% and oxidized starch to a solid content of 8.0%. The results are shown in Table-1.

Example 4
The same procedure as in Example 1 was performed except that the compound of Synthesis Example 1 was changed to the compound of Synthesis Example 2. The results are shown in Table-1.

Example 5
Synthesis Example 2 The same procedure as in Example 4 was performed except that the fluorescence inhibitor composed of the compound was applied to a solid content of 1.0%. The results are shown in Table-1.

Example 6
Synthesis Example 2 The same procedure as in Example 4 was conducted, except that the fluorescence inhibitor composed of the compound was applied to a solid content of 2.0% and oxidized starch to a solid content of 8.0%. The results are shown in Table-1.

Comparative Example 1
The same procedure as in Example 1 was performed except that the compound of Synthesis Example 1 was changed to the compound of Comparative Synthesis Example 1. The results are shown in Table-1.

Comparative Example 2
The same procedure as in Example 1 was performed except that the compound of Synthesis Example 1 was replaced with the compound of Comparative Synthesis Example 2. The results are shown in Table-1.

Comparative Example 3
The same procedure as in Example 1 was performed except that the compound of Synthesis Example 1 was replaced with the compound of Comparative Synthesis Example 3. The results are shown in Table-1.

Comparative Example 4
The same procedure as in Example 1 was conducted except that the compound of Synthesis Example 1 was replaced with Caltarex 2L (polyimidazoline series: manufactured by Clariant). The results are shown in Table-1.

Examples 7-12
Fluorescent whitening agent was obtained from Kayahor 3BS Liq. To Kayahor TAC Liq. It carried out similarly to Examples 1-6 except having changed to (made by Nippon Kayaku Co., Ltd.). The results are shown in Table-2. The fluorescence intensity of the base paper when no fluorescence inhibitor was added was 45. The results are shown in Table-2. Table 2 also shows the compatibility of the coating solution when the fluorescence inhibitor, paper strength agent and surface sizing agent are mixed.

Comparative Examples 5-8
Fluorescent whitening agent was obtained from Kayahor 3BS Liq. To Kayahor TAC Liq. The procedure was the same as in Comparative Examples 1 to 3, except that The results are shown in Table-2.

  As is clear from Tables 1 and 2, the examples of the present invention showed excellent fluorescence suppression effects by the external addition method, but the comparative examples conventionally used in the internal addition method have a fluorescence suppression effect. It was not enough.

Claims (3)

A fluorescence inhibitor comprising a compound having a structure represented by the following general formula (1).

(In the formula, R 1 and R 2 are H, CH ₃ or C ₂ H ₅ , and Y is Cl ⁻ , Br ⁻ , SO ₄ ⁻⁻ , CH ₃ SO ₃ ⁻ , NO ₃ ⁻ , or PO ₄ ^−−−. An anion represented by
  A method for suppressing fluorescence, comprising using the fluorescence inhibitor according to claim 1 when recycling used paper containing a fluorescent brightening agent.   The fluorescence suppression method according to claim 2, wherein the fluorescence suppression agent is added by an external addition method.