JPS6094687A - Pitch adsorbent for papermaking - 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 [Field of Application of the Invention] The present invention relates to a pitch adsorbent for paper manufacturing, and particularly to a pitch adsorbent for paper manufacturing that adsorbs pitch generated in the paper manufacturing process and removes it from the system.

[Prior art]

In the paper pulp manufacturing process, resins and other sticky substances contained in the pulp material, namely pitch, agglomerate at various points in the paper manufacturing process, staining tools, and causing pitch spots, reducing the quality of the product. Various pitch failures occur, such as causing the paper to break, or adversely affecting sheet formation and causing paper breakage.

The causative agents of pitch and the resulting pitch disorders differ depending on the type of pulp material. For example, in domestic pine wood, which is the raw material for sulfide pulp, the pitch content is calcium fatty acids, calcium resinates, and unsaponifiable materials, which are The problem was solved to some extent by excessive injection of sulfuric acid band. Douglas fir, which is an imported chip, has a large amount of unsaponifiable matter, and even after kraft cooking, a high proportion of pitch remains in the pulp, making pitch failure particularly likely.

Furthermore, southern woods such as lauan and rubber trees contain several times as much pitch as Douglas fir, and their ingredients are mainly comprised of highly sticky polymeric unsaponifiables. Even after treatment, it remains in the pulp, causing pitch problems that are different from conventional ones, such as difficulty in bleaching and deterioration of weather resistance. In addition, in old newspapers and miscellaneous paper, even after deinking, etc., the resin content of printing ink and spine remains as pitch, and in the case of used cardboard, the resin content of adhesive tapes and adhesives remains, creating new A pitch problem has occurred.

Various additives have been proposed to prevent these pitch defects. However, among these, anionic polymer additives have a high pitch adhesion prevention effect, but because they are anions, they do not react with other additives, such as cationic polymers such as paper strength agents, furnace water properties improvers, and retention improvers. This reduces the pitch adhesion prevention effect. However, nonionic surfactants have a low pinch adhesion prevention effect and affect sizing agents. Furthermore, inorganic adsorbents such as kaolin, talc, and Mistron paper (lipophilic talc produced in Montana, USA, hereinafter referred to as [fine powder talc-1)] are also used, but kaolin, talc, etc. have weak adsorption power and Although powdered talc shows good pitch adsorption power,
There may be problems with this.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide a pitch adsorbent for papermaking that has high pitch adsorption ability and does not affect other additives in the papermaking process. It is provided.

[Structure of the Invention] In order to achieve this object, the pitch adsorbent for paper manufacturing of the present invention contains hydrotalcites as an active ingredient, and is characterized in that it contains hydrotalcites. The gist is a pitch adsorbent for paper manufacturing.

The present invention will be explained in detail below.

The pitch adsorbent for backing paper of the present invention contains hydrotalcites.

Hydrotalcites refer to compounds represented by the following membrane composition formula.

(Mt-x””MX”(OH)z〕”(Ax/n”l
'ThHzo"l" - In the above formula, M2+ is Mg2+, zn
2+ represents a divalent metal ion such as Mn2+, Ni2+, etc., M3+ represents a trivalent metal ion such as A, 3+, Fe3+, Cr3+, etc., and A represents C1.

Indicates an n-valent anion such as NO3-1C03, oxalate ion, and salicylate ion. Further, X is a positive number within the range of 0<x<033, and n%m is a positive integer. Hydrotalcite is the most representative compound among hydrotalcites (Mg6Al(OH)+aco3.4.
H20) is a natural mineral that is produced as a mixture with benitrite, muscovite, etc. in limited areas such as the Sands, Norway's Snarm, and the Soviet Union's Urals. Note that hydrotalcite or other hydrotalcite compounds can also be produced by a known synthesis method.

Such hydrotalcites have anion exchange properties and normally adsorb negatively charged pitch with a strong adsorption force. Idrotalcites that have adsorbed pitch are incorporated into the paper and taken out of the papermaking process, so they do not remain in the system and become concentrated.

The adsorbent of the present invention can be used in all paper manufacturing processes in which paper and paperboard are made from raw wood or waste paper such as old newspapers and cardboard.

In these papermaking processes, the adsorbent of the present invention may be added at any point before the papermaking process, but preferably at a place where the pulp slurry is well stirred before papermaking.

It is particularly suitable to add to pulpers, machine chests, etc.

The amount of the adsorbent of the present invention added varies depending on the amount of pitch contained in the pulp to be treated, but it is preferably 0.01% by weight or more, particularly 0.1 to 5% by weight, based on the pulp.

There are no particular restrictions on the method of adding the adsorbent, but it is preferable to suspend it in distilled water or the like and add it in the form of a slurry.

Further, the pitch adsorbent of the present invention may be used in combination with other pitch control agents, such as fatty acid amide type, anionic polymer type, nonionic surfactant, etc., and each exhibits its own effects.

[Embodiments of the invention]

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 Preparation of pitch liquid: 3 g of pitch made by blending 65% by weight of rosin and 35% by weight of tall oil was dissolved in 11 ethyl alcohol to prepare a pitch liquid.

Preparation of adsorbent slurry: An adsorbent slurry was prepared by suspending 10 g of hydrotalcite in 400 ml of distilled water.

Adsorption test: The above adsorbent slurry! J 10 ml s The above pitch liquid and distilled water were mixed by changing the wrinkles of the pitch liquid and stirred. By centrifuging the resulting mixture, an adsorbent adsorbing pitch was obtained. After drying the obtained adsorbent for 17 days, it was mixed with 10 ml of an extraction solvent (a mixture of chloroform and acetic anhydride at a ratio (volume) of 1:1), stirred, and centrifuged again. 0.2 ml of concentrated sulfuric acid was added to 5 TrLg of the supernatant obtained by centrifugation, and after standing for 4 minutes, the absorbance (4001 m) was measured to determine the amount of pitch adsorbed.

The relationship between the amount of added pitch and the amount of adsorbed pitch that was subjected to the adsorption test is shown in Figure 1 (■).

Comparative Example 1 The relationship with the amount of added pitch was determined in the same manner as in Example 1, except that the adsorbent slurry was prepared using finely powdered Merck instead of hydrotalcite. The results are shown in Figure 1 (mouth seal).

From FIG. 1, it is recognized that the adsorbent of the present invention has pitch adsorption capacity that is more than twice that of the conventionally used adsorbent of fine powder talc.

Example 2 Hydrotalcite was added to a paper manufacturing system in which newspapers were made by blending 70% by weight of deinking bulbs obtained from waste newspapers. The addition point was the machine chest, and the amount added was 0.5% by weight based on the amount of pulp.

Conventionally, pitch derived from used newspapers adhered to various parts of the paper manufacturing process, causing problems such as pinholes and paper breaks in the product, but when hydrotalcite was added as described above, pitch adhesion was reduced. The amount of paper has been reduced significantly, and the number of times paper is cut out has been reduced from 34 times/month to 6 times/month, improving productivity.

〔Effect of the invention〕

As described in detail above, according to the papermaking pitch adsorbent of the present invention, pitch generated in various papermaking processes can be adsorbed with strong adsorption force and can be taken out of the papermaking system together with the paper. Furthermore, the adsorbent of the present invention does not affect or is not affected by other additives such as sizing agents, reactor water quality improvers, and retention improvers. Since the adsorption capacity is still extremely high, the effect can be sufficiently exerted even with a small amount added.

Therefore, by using the pitch adsorbent for paper manufacturing of the present invention, the incidence of pitch failure in the paper manufacturing process can be significantly reduced, and extremely high quality paper valves can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the results in Example 1 and Comparative Example 1, where the horizontal axis shows the amount of added pitch and the vertical axis shows the adsorption pitch. Agent Patent Attorney Tsuyoshi Shigeno (9)

Claims (2)

[Claims] (1) A pitch adsorbent for paper manufacturing, characterized by containing hydrotalcites. (2) The adsorbent according to claim 1, wherein the hydrotalcite is hydrotalcite.