JPS6323320B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for suppressing pitch damage in a paper manufacturing process. For more details, the general formula: (In the formula, R ¹ is a saturated or unsaturated alkyl group having 10 to 22 carbon atoms, and the sum of m and n is 16
The present invention relates to a method for suppressing pitch damage, which comprises adding an ethylene oxide nonionic surfactant represented by (an integer of 60 to 60) to a paper manufacturing process to suppress pitch damage. In the wood pulp and paper manufacturing process, pitch (however, pitch is usually small spherical particles made mainly of organic matter derived from natural resin or gummy pitch or other additives released from wood cells during the paper pulp manufacturing process). (meaning sticky aggregates) are generated, and such pitches aggregate and adhere to various parts of the papermaking machinery and equipment such as cheeseboards, beaters, and wires during the above manufacturing process, reducing work efficiency, or contaminating the product. This results in various pitch defects such as causing stains or holes in the pulp sheet or paper. Conventionally, various methods have been attempted as measures to prevent such pit damage. For example, inorganic salts such as alkalis, lime, and heavy metal oxides; Attempts have been made to add activators to the pulp slurry used in the papermaking process, but these methods have not always yielded satisfactory results. Regarding ethylene oxide nonionic surfactants, Japanese Patent Publication No. 22606/1983 describes secondary alcohol ethoxy whose alkyl group has 10 to 16 carbon atoms and the number of moles of ethylene oxide added is 8 to 15 for the purpose of removing resin from pulp. A method has been proposed in which a rate is added during alkali treatment in the pulping process. However, in the method of Japanese Patent Publication No. 50-22606, resin removal is still insufficient, and the resin content that could not be completely removed even by dispersion and washing during alkali treatment is caused by changes in liquid properties during bleaching and paper-making processes. It has been difficult to completely suppress pitch damage due to precipitation due to changes in pH from alkalinity to acidity. For this reason, the surfactant described in Japanese Patent Publication No. 50-22606 was added during the alkali treatment in the papermaking process to disperse and wash the pitch, and then the same surfactant was used experimentally in the cooking pulp selection process and in the papermaking process. Adding 0.2 to 0.6% by weight of pulp to the pulp during the process not only does not necessarily give the expected results regarding the dispersion effect of pitch, but also has a serious effect on paper quality, especially reducing paper sizing, resulting in poor workability due to foaming, etc. It has become clear that this can lead to unfavorable results. That is, by adding the compound of the above-mentioned known invention in a predetermined amount as described in the specification, it is possible to obtain a certain degree of meritorious effect in dispersing and cleaning pitch during the alkali treatment in the pulping process. However, even if it is applied to each process other than alkali treatment (ie, cooking) in order to further improve pitch damage, good results are not necessarily obtained. As a result of intensive studies to solve the above-mentioned drawbacks, the inventors of the present invention have discovered that when the compound defined by the above formula (1) is added to pulp slurry in the paper-making process, especially in the paper-making process, paper quality, especially The present invention was achieved by discovering that a remarkable pitch suppression effect can be obtained without adversely affecting the sizing. Any compound to be added in this invention can achieve the desired effect as long as it is within the range of the above defined formula, but specifically,
Examples of alkyl groups represented by R ¹ include: n-decyl, l-methyl-n-nonyl, l-ethyl-n-nonyl, l-n
-propyl-n-heptyl, l-n-butyl-n
-hexyl; n-undecyl, l-methyl-n-
Decyl, l-n-propyl-n-octyl, l-
n-butyl-n-heptyl, l-n-amyl-n
-hexyl; n-dodecyl, l-methyl-n-undecyl, l-ethyl-n-decyl, l-n-propyl-n-nonyl, l-n-butyl-n-octyl, l-n-amyl-n -heptyl; n-tridecyl, l-methyl-n-dodecyl, l-ethyl-n-undecyl, l-n-propyl-n-decyl, l-n-butyl-n-nonyl, l-n-amyl-n -octyl, l-n-hexyl-n-heptyl; n-tetradecyl, l-methyl-n-dodecyl, l-ethyl-n-dodecyl, l-n-propyl-n-undecyl, l-n-butyl-n −
Decyl, l-n-amyl-n-nonyl, l-n-
hexyl-n-octyl; n-pentadecyl, l
-Methyl-n-tetradecyl, l-ethyl-n-
tridecyl, l-n-propyl-n-dodecyl,
l-n-butyl-n-undecyl, l-n-amyl-n-decyl, l-n-hexyl-n-nonyl, l-n-heptyl-n-octyl; n-hexadecyl, l-methyl-n- Pentadecyl, l-
Ethyl-n-tetradecyl, l-n-propyl-
n-tridecyl, l-n-butyl-n-dodecyl, l-n-amyl-n-undecyl, l-n-
hexyl-n-decyl, l-n-heptyl-n-
Nonyl; n-octadecyl, n-eicosyl, n
-Docosyl; Groups such as oleyl can be mentioned. Further, the compound added in the present invention may be a mixture obtained by adding ethylene oxide to mixed alkyl, alcohol, or mixed alkyl amine by known means; examples of such compounds include, for example, carbon Those derived from primary or secondary saturated alcohols synthesized from α-olefins or n-paraffins having 10 to 22 atoms by the oxo method or oxidation; those derived from natural oils and fats such as coconut oil or coconut fat, beef tallow, etc. Examples include things such as The compound represented by the above general formula (), which is the pitch-controlling active ingredient of this invention, foams when added to any papermaking process, including cooking, screening, and bleaching papermaking processes.
Although it is possible to obtain an excellent effect of suppressing pitch damage without causing a deterioration in paper quality, it is possible to prevent pitch damage by adopting a multi-stage addition method, such as a two-stage addition method in which the addition is performed in the cooking process and then in the papermaking process. Furthermore, it can be suppressed to a large extent. Furthermore, in this multi-stage addition method, various modifications can be adopted, such as using a surfactant other than the present invention in the cooking process and further using the surfactant according to the present invention in the papermaking process. The quantitative usage range of the nonionic surfactant of this invention is as follows:
Although it varies slightly depending on the amount of pitch present in the papermaking process, a sufficient effect can be obtained by adding 0.001 to 0.2% by weight to the pulp, and addition of 0.01 to 0.03% by weight is preferable. Of course, it is possible to use the nonionic surfactant of the present invention in a larger amount than this, but this is not desirable because it increases the cost and has an adverse effect on the paper quality despite its effectiveness in suppressing pitch damage. Further, in the present invention, the above-mentioned active ingredient can be dissolved or dispersed in a suitable solvent such as alcohol, water, etc., and if necessary, an emulsifier, a dispersant, etc. can be added to form a formulation, and then used. Next, the present invention will be explained with reference to Examples. Example 1 Take 10g of unbleached wet pulp in absolute dry terms and mix with 500ml of pure water for 3 minutes with a high-speed mixer.
I passed it naturally with two papers. 500 ml of the filtrate was placed in a beaker (No. 2), 20 mg of various surfactants were added, the lining was lined with well-washed felt 10 cm x 35 cm, and the pH was adjusted to 2 with sulfuric acid. After stirring at 1000 rpm for 1 hour, the resin adhering to the felt was extracted with a mixture of alcohol and benzene (volume ratio 1:2), and the amount of pitch was measured. The results are shown in Table 1.

【table】

[Table] As can be seen from Table 1, in the general formula ()
Those in which the number of carbon atoms in R ¹ was about 18 and the number of moles of ethylene oxide added were about 30 showed particularly excellent pitch adhesion prevention effects. In addition, those having an adhesion inhibition rate of 50% or more can be used as pitch suppressants. Example 2 Unbleached pulp slurry (pulp concentration 3.3%) 700ml
A predetermined amount of nonionic activator was added in the form of a 15% aqueous solution to the mixture and stirred for 2 minutes. Then, 0.2% by weight of a 30% aqueous solution of a sizing agent [Sizepine SPN-700, manufactured by Arakawa Chemical Co., Ltd.] was added to the pulp, and after 2 minutes, a 2.2% aqueous solution of sulfuric acid was added, and after another 2 minutes, a paper A 7.5% aqueous solution of a force enhancer [Polystron 117, manufactured by Arakawa Chemical Co., Ltd.] was added at 2.5% by weight and 0.1% by weight, respectively, based on the pulp. The total amount with water is 7
After diluting the paper, 365 ml of the paper was hand-printed, pressed for 7 minutes, and then dried in a rotary dryer at 100° C. for 1 minute to obtain paper strips with a basis weight of 58 g/m ² . The Steckigt size degree (seconds) was measured for this piece of paper using a conventional method (Japanese Industrial Standards, JIS P8122). The results are shown in Table 2.

[Table] As is clear from Table 2, trial No. 1 (comparison)
have a significant negative impact on sizing, while none within the scope of this invention have a significant impact on sizing. Example 3 N-polyoxyethylene alkylamine (alkyl carbon number: 18, number of added moles of ethylene oxide
30) Kraft paper composition consisting of 20% water and 80%
0.5% by weight of the pulp, that is, a component concentration of 0.01% by weight, was added to the outlet of a low-concentration chiest in a paper manufacturing system that produces paper at a rate of 300 tons/day. There was no effect on sizing or paper quality, and the sticky pitches that had occurred on the wire and press roll were reduced, eliminating any trouble. Although a 12 mole adduct of ethylene oxide of a secondary alcohol having 13 carbon atoms was added to low-concentration CHEST at 0.1% by weight based on the pulp, sticky pitches adhered to the wire, and the wire was cleaned more than once a day. It was necessary to stop the machine. Example 4 N-polyoxyethylene alkylamine (alkyl carbon number: 18, number of added moles of ethylene oxide
30) Kraft paper composition consisting of 20% water and 80%
When 0.1% by weight of the pulp, that is, 0.05% by weight in component concentration, was added to the outlet of a pulpless filter in the selection process of a paper manufacturing system that produces 200 tons of paper per day, the pitches occurring on the wire were reduced. Tall oil fatty acid N,N dimethylamide to pulp 0.015
When added in combination to the wt% white water fan pump part, the pitches adhering to the press roll and blanket disappeared, and a synergistic effect was obtained, indicating that this is an effective pitch control method. Of course, no decrease in size or influence on paper quality was observed. Example 5 0.01% by weight of N-polyoxyethylene (number of alkyl carbons: 18, number of added moles of ethylene oxide: 16) was added to the papermaking process machine chest section of a certain paper mill that produces 50 tons/day of medium-quality paper per pulp. The sticky pitches that conventionally occurred and adhered to the press rolls and caused paper breakage did not adhere at all, making it possible for the paper machine to operate continuously. Example 6 N-polyoxyethylene tallow alkylamine (30 moles of ethylene oxide added) 20%, water 80%
A composition consisting of 0.03% by weight of E ₂ was added to the outlet of stage C of the bleaching process to produce 200 tons/day of bleached kraft pulp.
When 0.05% by weight was added to the opening of the column, the pitch that had occurred in the bleached kraft pulp disappeared.
The bleaching process at this factory is stage C (chlorine), stage E ₁ (alkali), stage H (hypo), stage E ₂ (alkali), and stage D ₁ (2).
chlorine oxide) and D ₂ (chlorine dioxide). Example 7 The composition used in Example 3 was added in an amount of 0.2% based on the pulp to the middle layer raw material pulper section of a paperboard machine producing 90 tons/day. Waste newspaper was used as the raw material for the middle layer, and pitches caused by the ink were generated on the wire, but the pitches that had adhered to the wire disappeared 8 hours after the composition was added.

Claims (1)

[Claims] 1. General formula: (In the formula, R ¹ is a saturated or unsaturated alkyl group having 10 to 22 carbon atoms, and the sum of m and n is 16
A method for suppressing pitch damage, which comprises adding an ethylene oxide nonionic surfactant represented by (an integer of ~60) to a paper manufacturing process to suppress pitch damage. 2. The method according to claim 1, wherein the nonionic surfactant represented by formula () is added in an amount of 0.001 to 0.2% by weight based on the pulp. 3. The method according to claim 1 or 2, wherein the addition is carried out once or twice or more at any step in the papermaking process. 4. The method according to any one of claims 1 to 3, wherein the addition is performed at least during the papermaking process. 5. The method according to any one of claims 1 to 4, wherein R ¹ in formula () has 12 to 18 carbon atoms and the total number of moles of ethylene oxide added is 18 to 30.