JP2000034691A - Production of highly bulky pulp sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for affording a bulky pulp sheet without impairing the effect of the sizing agent used. SOLUTION: This method for affording a highly bulky pulp sheet comprises addition, at any point in the papermaking process, of an ester compound (except fatty acid sucrose esters) with the alcoholic OH groups 10-95 equivalent % ester-substituted per mol of the polyhydric alcohol, HLB number of 1-14 and melting point of <=100 deg.C selected from ester compounds each made from a polyhydric alcohol and a fatty acid and having 2-4C oxyalkylene groups at <12 mol (but>0 mol) on average per mol of the ester compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a bulky pulp sheet which improves the bulkiness of a sheet obtained by making a pulp raw material and does not reduce the effect of a sizing agent.

[0002]

2. Description of the Related Art In recent years, there has been a demand for paper of high quality, for example, excellent in printability and volume. The printability and voluminousness are closely related to the bulkiness of the paper, and various methods for improving the bulkiness have been tried in the past. For example, a crosslinked pulp is used (for example, JP-A-4-185792), a method of mixing with synthetic fibers (for example, JP-A-3-269199), or a filler such as an inorganic substance is filled between pulp fibers (for example, JP-A-3-185199). There is a method of producing voids (Japanese Patent Application Laid-Open No. 5-230798, etc.), but pulp cannot be recycled or the smoothness of paper is impaired. A bulking agent for paper containing a specific alcohol and / or a polyoxyalkylene adduct thereof (WO98 / 03730) is also disclosed, but the effect of a sizing agent usually used in combination may not be sufficiently exhibited. Furthermore, fatty acid polyamide polyamine type bulking agents are commercially available, but their performance is not sufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sufficient bulking effect even with a small amount of addition, and to use a specific compound which does not decrease the performance of the sizing agent added in the papermaking process. An object of the present invention is to provide a method for producing a bulky pulp sheet.

[0004]

According to the present invention, there is provided an ester compound of a polyhydric alcohol and a fatty acid and an ester compound of a polyhydric alcohol and a fatty acid in any one of the papermaking steps, wherein 0 mol per mol of the ester compound is averaged. More than 12 moles of OH in alcohol per mole of polyhydric alcohol selected from ester compounds having an oxyalkylene having 2 to 4 carbon atoms (hereinafter referred to as OA) group, which is ester-substituted, Provided is a method for producing a high-bulk pulp sheet to which an ester compound having an HLB of 1 to 14 and a melting point of 100 ° C. or less (excluding fatty acid sucrose ester) is added.

Further, the present invention provides an ester compound of a polyhydric alcohol and a fatty acid and an ester compound of a polyhydric alcohol and a fatty acid in any one of the papermaking steps, wherein an average of more than 0 mol and less than 12 mol per mol of the ester compound. OH in alcohol per mole of polyhydric alcohol selected from ester compounds having an OA group having 2 to 4 carbon atoms
Provided is a high bulk pulp sheet produced by adding an ester compound (excluding fatty acid sucrose ester) having a substitution of 10 to 95 equivalent%, an HLB of 1 to 14 and a melting point of 100 ° C. or less.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Ester compound used in the present invention (hereinafter sometimes referred to as the ester compound of the present invention)
Is an ester compound of a polyhydric alcohol and a fatty acid (an ester compound not containing an OA group), wherein 10 to 95 equivalent% of OH in the alcohol is ester-substituted per 1 mol of the polyhydric alcohol, and HLB is 1 to 14, Melting point not higher than 100 ° C. An ester compound of a polyhydric alcohol and a fatty acid,
OH in alcohol is 10 ~ per mole of polyhydric alcohol
It has 95 equivalent% of ester-substituted OA groups having 2 to 4 carbon atoms, more than 0 moles and less than 12 moles on average per mole of the ester compound, HLB of 1 to 14, and melting point of 100 ° C. or less. These may be used in combination, or two or more of each may be used.

The polyhydric alcohol constituting the ester compound of the present invention has a total carbon number of 2 which may contain an ether group.
-24 to 2-14 alcohols are preferred. As the dihydric alcohol, the total number of carbon atoms which may contain an ether group is 2 to 2.
10 alcohols, for example, propylene glycol, dipropylene glycol, butylene glycol, dibutylene glycol, ethylene glycol, diethylene glycol, and polyethylene glycol, as a trivalent or higher valent alcohol, may have an ether and have a total carbon number of 3 to 24. Alcohol, total number of hydroxyl groups in one molecule / total number of carbons = 0.4 to 1
For example, glycerin, poly (n = 2 to 5) glycerin, pentaerythritol, dipentaerythritol, arabitol, sorbitol, stachyose, erythritol, arabit, mannitol, glucose and the like can be mentioned. Preferably, ethylene glycol, diethylene glycol, propylene glycol, an alcohol having a total of 3 to 12 carbon atoms which may have an ether group, and a trivalent or higher alcohol having a hydroxyl number / total carbon number in one molecule of 0.5 to 1 It is. More preferred are glycerin, poly (n = 2 to 4) glycerin, and pentaerythritol.

The fatty acids constituting the ester compound of the present invention include fatty acids having 1 to 24 carbon atoms, preferably 10 to 22 carbon atoms, and may be any of saturated, unsaturated, straight-chain and branched chains. Particularly, straight-chain saturated fatty acids are preferred. More preferred are lauric acid, stearic acid, palmitic acid, myristic acid, and behenic acid.

The ester compound of the present invention can be obtained by performing a conventionally known esterification reaction and alkylene oxide addition reaction. For example, if necessary for a mixture of a fatty acid and a polyhydric alcohol, an esterification catalyst may be added, and
An ester compound is obtained by reacting at -250 ° C, and an alkylene oxide adduct is obtained by adding an alkylene oxide in the presence of an alkali catalyst or the like. Further, after adding an alkylene oxide to a fatty acid or a polyhydric alcohol, esterification may be performed.
Furthermore, it may be obtained by only adding an alkylene oxide to a fatty acid.

The average degree of substitution of the ester compound of the present invention per mole of polyhydric alcohol is
OH is ester-substituted by 10 to 95 equivalent%, particularly preferably one having 1 to 2 mol of fatty acid groups per 1 mol of polyhydric alcohol.

In the present invention, when an ester compound containing an OA group having 2 to 4 carbon atoms is used, the number thereof is more than 0 mol and less than 12 mol on average per 1 mol of the ester compound.
Mol or less, specifically 0.1 to 6 mol. In addition,
When polyhydric alcohols that can be OA groups, such as ethylene glycol, are used, they are also included in the number of OA groups. The OA group is formed by adding an alkylene oxide having 2 to 4 carbon atoms. As the alkylene oxide, ethylene oxide (EO) and propylene oxide (PO) are preferable. These may be any of EO, PO or a mixture of EO and PO. In the present invention, it is particularly preferable to use an ester compound containing no OA group.

The ester compound of the present invention has an HLB of 1 to 1
4, preferably 1.5 to 10, more preferably 2.5 to 6. HLB is a measure of the hydrophilicity of a surfactant,
The higher the value, the higher the hydrophilicity. In the present invention, the HLB of each compound is calculated by the following formula according to the method of Griffin.

[0013]

(Equation 1)

However, the hydrophilic group in the present invention means the following group in the ester compound. (1)-(CH ₂ CH ₂ O) _m-

[0015]

Embedded image

(3) Trihydric or higher alcohols having a total of 3 to 24 carbon atoms which may have an ether group, wherein the total number of hydroxyl groups / the total number of carbon atoms in one molecule is 0.4 to 1. Derived groups. (4) An oxygen atom adjacent to the carbonyl group.

Further, the ester compound used in the present invention has a melting point of 100 from the viewpoint of handleability and retention of size performance.
° C or lower, preferably -15 ° C or higher and 80 ° C or lower, more preferably 20 ° C or higher and 70 ° C or lower. Melting point was determined by using a differential scanning calorimeter (D
The temperature at which the peak rises when measured in (SC) (heating rate 2 ° C / min).

The ester compound of the present invention preferably has an HLB of 2 to 8 and a melting point of 10 to 70 ° C, more preferably an HLB of 2 to 7 and a melting point of 45 to 70 ° C. In this range, favorable results can be obtained due to the bulking effect and the size effect (maintaining the effect of the sizing agent).

The ester compound of the present invention is added in any of the papermaking processes, and a liquid product may be added as it is, but a solid product may be pulverized or melted by heating or diluted with water or the like. May be added. If necessary, nonionic, anionic, cationic, polymer,
Preferably, a nonionic surfactant may be used as an emulsifier or a dispersant. In this case, the ratio of the ester compound of the present invention to the surfactant is [ester compound of the present invention] /surfactant=99.5/0.5 to 70/30 (weight ratio), preferably 98/2 to 80/20. It is.

The pulp raw material to which the ester compound of the present invention can be applied includes virgin pulp such as mechanical pulp such as TMP (thermomechanical pulp), chemical pulp such as LBKP (hardwood bleached pulp), and various kinds of used paper pulp. It is widely applicable to pulp in general. The place where the ester compound of the present invention is added is not particularly limited as long as it is a papermaking process until the diluted liquid of the pulp raw material is drained while traveling on the wire mesh and forms a paper layer. In the factory, refiners, machine chests,
A place where it can be uniformly blended with the pulp raw material, such as by adding it in a head box, is desirable. After the ester compound of the present invention is added to the pulp raw material, the paper is made as it is and remains on the paper. The amount of the ester compound of the present invention is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the pulp raw material.
However, depending on the system, an excellent bulking effect can be obtained even by adding a small amount of 0.1 to 1% by weight.

The pulp sheet obtained by using the ester compound of the present invention has a higher tenacity (measuring method:
More preferably, it is 5% or more, preferably 7% or more.

At the time of paper making, a filler, a retention improver, a drainage improver, a paper strength improver and the like may be added in addition to sizing agents such as rosin, alkyl ketene dimer, gelatin, starch, latex and the like. The sizing agent is used to block water and ink from penetrating the surface and inside of the paper with a water-resistant substance, and to be added to the pulp slurry (internal sizing) or applied to the paper made (surface sizing). Is processed by The sizing agent is usually added in an amount of 0.01 to 1.0% by weight based on the pulp raw material, depending on the type of paper. The ester compound of the present invention is also excellent in the effect of maintaining sizing performance, and thus is suitable for a production method for obtaining a high-bulk pulp sheet using a sizing agent in combination.

[0023]

EXAMPLES Examples 1 to 23 and Comparative Examples 1 to 10 [Pulp Raw Materials] As the pulp raw materials, the following wastepaper pulp and virgin pulp were used. <Recovered paper pulp> Recovered paper pulp consists of raw paper recovered from the market (newspaper / flyer = 70/30%), hot water and sodium hydroxide (based on raw materials) 1% (based on weight, the same applies hereinafter), sodium silicate (based on raw materials) 3%, 30% hydrogen peroxide water (based on raw material) 3%,
Tallow / glycerin (1: 1) EO70 mol PO as deinking agent
A 10% block adduct (average number of moles) of 0.3% (based on raw material) was added, and a 1% deinked pulp slurry which had been subjected to flotation treatment, water washing and concentration adjustment after defibration was used. The freeness of this product was 220 ml. <Virgin pulp> Virgin pulp is obtained by disintegrating and beaten LBKP (hardwood bleached pulp) with a beater at room temperature.
% Of LBKP slurry was used. The freeness of this product was 420 ml.

[Paper making method] The pulp was weighed so that the sheet after weighing 1% pulp slurry was 60 g / m ² , and the pH was adjusted to 4.5 with a sulfuric acid band.
Then, various bulking agents shown in Tables 1 and 2 were added to pulp at 0.8.
%, And rosin size as a sizing agent was added to the pulp at 0.5%. After stirring, paper was formed on a square tappi paper machine with an 80 mesh wire to obtain a sheet. The sheet after paper making is 3.5 kg / cm
^The mixture was pressed with a press machine for 2 minutes at 2 and dried at 105 ° C. for 1 minute using a mirror-surface dryer. Dry the sheet at 20 ℃,
After conditioning for one day under the condition of a humidity of 65%, the bulkiness and sizing degree of the paper were measured by the following methods. The measured value is the average of 10 measurements. Table 3 shows the results.

<Evaluation Items and Methods> Bulkness (Tightness) The weighed (g / m ² ) and thickness (mm) of the conditioned sheet were measured, and the tightness (g / cm ³ ) was calculated by the following formula. I asked. Calculation formula: bulkiness (tensity) = (weighing) / (thickness) x 0.001 The smaller the absolute value of the strain, the higher the bulk, and the difference of 0.02 in the strain is sufficiently recognized as a significant difference. .・ Sizing properties The paper was tested according to the JIS P 8122-54 paper Stechig sizing test method. That is, a test piece (2 cm × 2 cm) of a paper made on a 2% rhodan ammonium solution at 20 ± 1 ° C. in a petri dish.
At the same time, float a drop of 1% ferric chloride solution at the same temperature with a pipette on the specimen, and measure the number of seconds from when three red spots appear on the specimen. Is defined as the size degree. It is preferable from the standpoint of operation that the sizing degree keeps a value of 80% or more of the blank (Comparative Example 1).

[0026]

[Table 1]

(Note) The composition of Example 23 is a 10% emulsion of Example 3 / polyoxyethylene (average number of moles of EO added: 10) sorbitan monolaurate = 95/5 (weight ratio).

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

According to the present invention, an excellent bulking effect can be obtained even with a small amount of addition, and a bulky pulp sheet can be obtained without impairing the effect of the sizing agent.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoyuki Ikenaga, 1334 Minato 1334, Minato, Wakayama-shi, Kao Co., Ltd. Person Yoichi Ishibashi 1334 Minato, Wakayama City, Wakayama Prefecture Kao Corporation (72) Inventor Yasuo Ishii 1334 Minato, Wakayama City, Wakayama Prefecture Kao Corporation

Claims (3)

[Claims] In one of the papermaking processes, an ester compound of a polyhydric alcohol and a fatty acid and an ester compound of a polyhydric alcohol and a fatty acid having an average of more than 0 mol and less than 12 mol of carbon atoms per mol of the ester compound. OH in the alcohol per mole of polyhydric alcohol selected from ester compounds having from 4 to 4 oxyalkylene groups
10-95 equivalent% ester-substituted, HLB 1-14, melting point
A method for producing a high-bulk pulp sheet to which an ester compound (excluding fatty acid sucrose ester) having a temperature of 100 ° C or lower is added. 2. The method according to claim 1, further comprising adding a sizing agent in any of the papermaking steps. 3. An ester compound of a polyhydric alcohol and a fatty acid and an ester compound of a polyhydric alcohol and a fatty acid having an average of more than 0 moles and less than 12 moles per mole of the ester compound in any one of the papermaking steps. OH in the alcohol per mole of polyhydric alcohol selected from ester compounds having from 4 to 4 oxyalkylene groups
A high bulk pulp sheet produced by adding an ester compound (excluding fatty acid sucrose ester) having a substitution of 10 to 95 equivalent%, an HLB of 1 to 14 and a melting point of 100 ° C. or less.