JPS626039B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for suppressing pitch injury. More specifically, this invention is based on the general formula (): R ¹ COOR ² () (wherein R ¹ is a saturated or unsaturated aliphatic hydrocarbon group having 10 to 19 carbon atoms, and R ² is a saturated or unsaturated aliphatic hydrocarbon group having 6 or less carbon atoms. A composition containing as a main component one or more compounds represented by (a saturated or unsaturated aliphatic hydrocarbon group) is added to the pulp slurry during the papermaking process to suppress pitch damage. The present invention relates to a method for suppressing pitch disorder characterized by: In recent years, as the proportion of South Sea wood used in the production of wood pulp has increased, pitch has been used in the paper manufacturing process (however, pitch here refers to natural resin or gummy pitch or other types of wood released from wood cells during the paper pulp manufacturing process). (meaning small spherical sticky aggregates mainly composed of organic substances derived from additives) are increasingly being formed. This pitch aggregates and adheres to papermaking machine equipment such as cheeseboards, beaters, wires, felts, and rolls during the papermaking process, lowering work efficiency, or getting mixed into the product, causing stains or holes on pulp sheets or paper. This can lead to a variety of problems, including the need to stop operations in extreme cases. Conventionally, various methods have been adopted as measures to prevent such pitch failures. For example, polyphosphates, various surfactants, emulsifiers, or adsorbents such as fine talc or kaolin are used. Ethylene oxide nonionic surfactants are generally widely used as the above-mentioned surfactants, but in recent years, as the degree of recycling of white water in the papermaking process has increased in order to save industrial water, the paper quality of the produced paper has increased. These surfactants have come to show adverse effects. In order to eliminate the above-mentioned drawbacks, Japanese Patent Publication No. 40-964 proposed papermaking using N/N-dimethylamide, a straight-chain carboxylic acid having 18 carbon atoms and at least one double bond between carbons. It is proposed to be used in the process. The main effect of this straight-chain unsaturated carboxylic acid N-N-dimethylamide is to coat the small spherical pitches or, throughout the papermaking process, to the tendency of the molecules to agglomerate to obstructive sizes or the various types of metals. The purpose is to significantly reduce the tendency of the material to adhere to surfaces and other materials. However, the N.N-dimethylamide disclosed in Japanese Patent Publication No. 40-964 is not necessarily advantageous in terms of cost since dimethylamine is used in the process for producing the compound itself. The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and surprisingly, they found that the compound represented by the above general formula ( In addition to exhibiting the above-mentioned pitch disorder suppressing effect, it does not cause phenomena that adversely affect the paper quality, such as a decrease in foaming properties or the fixation of sizing agents, and is also relatively easy to obtain and inexpensive. This is what led to this invention. In this invention, any compound added as an active ingredient to the pulp slurry in the papermaking process can achieve the desired effect as long as it is within the range defined by the general formula (). Examples of R ¹ COOH constituting ) are undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, petroselic acid, oleic acid, elaidic acid, linoleic acid, and linolenic acid. , stearolic acid, ricinoleic acid, lysine stearolic acid, nonadecanoic acid, and arachidic acid. Examples of R ² OH constituting the defining formula () include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, amyl alcohol, isoamyl alcohol, hexyl alcohol, and the like. The compound represented by the general formula () is preferably liquid at room temperature, and more preferably liquid at around 4°C. Furthermore, when added as an active ingredient in this invention,
A single compound may be added, or the general formula ()
may be added as a mixture of compounds falling within the definition of , examples of which may be added as a mixture include esters of mixed fatty acids forming natural fats and oils, such as coconut oil, tall oil, soybean oil, rice sugar oil, etc. can be mentioned. Furthermore, 1 ethylene oxide nonionic surfactant is added to 99 to 75 parts by weight of the compound of general formula ().
~25 parts by weight, preferably a compound of general formula () 90
By adding 10 to 20 parts by weight to ~80 parts by weight, the pitch suppressing effect of the compound of general formula () can be further increased, and the ethylene oxide nonionic surfactant can be used alone when recycling white water. It is possible to create a composition that eliminates the above-mentioned adverse effects on paper quality that sometimes occur. Ethylene oxide nonionic surfactants that can be used include polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ether, fatty acid ester of polyoxyethylene glycol, reaction product of fatty acid amide and ethylene oxide, and reaction product of alkanesulfonamide and ethylene oxide. Examples include reaction products, N-polyoxyethylenealkylamine, and the like. Among these, polyoxyethylene alkyl phenol ether is preferably used, and polyoxyethylene nonyl phenol ether to which 10 to 16 moles of ethylene oxide are added is particularly preferably used. The reason why such an ethylene oxide nonionic surfactant exhibits an excellent combination effect is that this surfactant disperses the water-insoluble active ingredient in a colloidal manner, increasing the chance of collision with pitch particles. This is thought to be because the effect of suppressing pitch of the active ingredient can be effectively brought out. Furthermore, since only a small amount of the ethylene oxide nonionic surfactant is added, foaming of the slurry liquid does not occur, and it is thought that an adverse effect on the paper quality can be suppressed. The quantitative usage range of the compound defined by the general formula () of this invention depends on the amount of pitch present in the pulp slurry, but with respect to the pulp,
Sufficient effects can be achieved by adding 0.001 to 0.5% by weight, and addition of 0.01 to 0.1% by weight is preferred. Furthermore, in this invention, each of the above components includes alcohol,
It can be used by dissolving or dispersing it in a suitable solvent such as water and formulating it. Next, the present invention will be explained with reference to Examples. Test example 1 Take 10g of unbleached wet pulp (bone dry equivalent),
Stir 500ml of tap water with a high-speed mixer for 3 minutes, separate with a metal cloth, and put 500ml of the liquid into beaker 2.
Add 30 mg of pitch control agent, line with well-washed felt 10 cm x 35 cm, and add sulfuric acid.
Adjusted to PH2. After stirring at a rotation speed of 1000 rpm for 1 hour, the resin attached to the felt was washed with alcohol.
The amount of pitch was measured using a Soxhlet extractor with a benzene (1:2 volume) mixture. Table 1 shows the results.
Shown below.

【table】

[Table] As can be seen from Table 1, compounds or mixtures thereof that are liquid at room temperature and satisfy R ¹ and R ² of the general formula () exhibit a pitch adhesion prevention effect, and the commonly used polyoxyethylene nonyl It can be seen that the addition of a small amount of phenol ether improves the anti-pitch adhesion effect of the above compounds or mixtures thereof. Test Example 2 A 0.01% aqueous solution 1 of the pitch control agent of the present invention was placed in a vinyl chloride box measuring 14 cm x 19 cm x 20 cm (height), and a pump having a discharge rate of 35/min was connected to the box. The liquid was then circulated to determine the foaming properties of the pitch control agent of the present invention. The results are shown in Table 2.

【table】

[Table] *Surfactant Polyoxyethylene Nonylph
Enol ether (EO addition moles
Number 11)
Satisfying R ¹ and R ² of the general formula () of the present invention,
Natural fat and oil fatty acid esters, which are considered to be compounds or mixtures thereof, have almost no foaming properties and have 15
% of the nonionic surfactant, there is no practical problem with the foaming properties of the composition. Example 1 At a factory that manufactures 200 tons of kraft paper per day, PH
When making paper from pulp slurry with a temperature of 3 to 5 and a temperature of 15°C to 40°C, a large amount of pitch was deposited on the wire of the papermaking material within 10 hours when no pitch control agent was added. Removal of this deposited pitch required stopping the machine and cleaning the wire. Before resuming work, tall oil fatty acid methyl was added to the pulp in the stock box that feeds the stock into the paper making head box.
0.1% by weight, or 20 parts per million parts of slurry, was added. In this case, no pitches were observed on the wire or press roll even 24 hours after the start of work. Example 2 In a paper manufacturing system that produces 250 tons of kraft paperboard per day, in which the pH of the slurry is 4.0 to 6.0 and the temperature is 40°C, deposits are generated on the head box and are removed after a certain period of time. It was then carried onto press rolls to tear the sheet. For this reason, cleaning was required once every two days. When this sediment was extracted with alcohol benzene, the extraction rate was 50
It was %. Tall oil fatty acid methyl ester (85 parts) and polyoxyethylene nonylphenol ether (EO
When a composition consisting of 11) (15%) of added moles was added to the white water pit fan pump side in an amount of 0.01% by weight per pulp, there was no need to clean the machine even after one week had passed. Example 3 Methyl oleate was added in an amount of 0.05% by weight based on the pulp into the outlet of a pulp press filter in the selection process of a paper manufacturing system that produces 300 tons of newspaper per day. When the methyl oleate of the present invention was not added, the wire cleaning due to pitch damage was once or twice a day, but with the addition of the methyl oleate, the cleaning was reduced to once every four days. Furthermore, no adverse effects on size or paper quality were observed. Test Example 3 Methyl oleate was added to pulp with the following composition.
Drug A (Example) consisting of 85% by weight of oleic acid N-N-dimethylamide and 15% by weight of polyoxyethylene nonyl phenyl ether (number of moles of EO added is 10), and 85% by weight of oleic acid N/N-dimethylamide and polyoxyethylene nonyl phenyl ether. Drug B consisting of 15% by weight (same as above)
(Comparative Example) was added in a predetermined amount. (Sizing agent) Harima Kasei Kogyo Co., Ltd. Ha-Size L-50 (rosin-based sizing agent) (Fixing agent) Asada Chemical Co., Ltd. Liquid sulfuric acid band (contains 8% as Al ₂ O ₃ ) (Pulp) Commercially available LBKP pulp (3 water degrees SR = 54) From this pulp, paper samples ( Basis weight
65g) were produced respectively. The water absorption of each sample was measured according to JIS P8140 (paper and paperboard water absorption test method), and the results are shown in the table below.

【table】

[Table] As shown in the results, in the method of the present invention, no increase in water absorption due to the addition of chemicals was observed, indicating that the adhesion of the sizing agent was not adversely affected. On the other hand, in the case of N.N-dimethylamide, the amount of water absorbed increases with the amount added, and it is found that this has an adverse effect on the adhesion of the sizing agent.

Claims (1)

[Claims] 1 General formula (): R ¹ COOR ² () (In the formula, R ¹ is a saturated or unsaturated aliphatic hydrocarbon group having 10 to 19 carbon atoms, and R ² is a carbon number of 6 or less. A composition containing as a main component one or more compounds represented by (a saturated or unsaturated aliphatic hydrocarbon group) is added to pulp slurry during the papermaking process to suppress pitch damage. A method for suppressing pitch disorder characterized by: 2 Compound 99 whose composition is represented by general formula ()
The method according to claim 1, wherein 1 to 25 parts by weight of an ethylene oxide nonionic surfactant is blended to 75 parts by weight. 3. The method according to claim 1 or 2, wherein the compound represented by the general formula () is added in an amount of 0.001 to 0.5% by weight to the pulp during the papermaking process.