JPH06299499A - Neutralized paper - Google Patents

Abstract

PURPOSE:To obtain neutralized paper using a size setting agent in place of cationic starch. CONSTITUTION:This neutralized paper is produced by adding a neutral rosin as a sizing agent, a specific amount of polyacrylamide containing a cyclic secondary amine as a functional group as a setting agent for the neutral rosin and preferably aluminum sulfate as an auxiliary for developing sizing effect to pulp slurry and making the mixture into paper. Furthermore, the neutral rosin is preferably an emulsion emulsified by anionic protective colloids. Since problems accompanied by addition of the cationic starch are avoided by using this setting agent, the neutralized paper has sufficient sizing property.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neutral paper which uses a neutral rosin as a sizing agent and a specific size fixing agent which is effective even in a small addition amount.

[0002]

2. Description of the Related Art In recent years, pH is adjusted to 6 to 9 for papermaking because it is advantageous in preventing deterioration of paper over time, improving water consumption per unit of production, saving energy, and preventing machine corrosion. The so-called neutral paper has been widely used in place of conventional acid paper.

As the sizing agent used for the neutral paper, there are alkyl ketene dimer, alkenyl succinic anhydride, etc. in addition to the neutral rosin. By the way, conventionally used alkyl ketene dimer and alkenyl succinic anhydride are designed so as to express sizing property by reacting with the hydroxyl group of pulp, and the alkyl ketene dimer, which has a relatively slow reaction, has a rise in size. Poor, also, the relatively fast reaction of alkenyl succinic anhydride decomposes by reacting with water, chest of raw materials and piping, the problem of fouling the roll of the machine, or when using alkyl ketene dimer, If the added amount is large, there is a problem that the surface of the paper is likely to slip because some of the crystals crystallize on the surface.
Therefore, recently, a so-called neutral rosin, which is a rosin-based sizing agent that can be used for neutral paper, has been developed.

By the way, in the papermaking of neutral paper, it is common practice to add a modified starch having a cationic group, a so-called positive starch, for the purpose of fixing the sizing agent and improving the yield of the filler. However, in order to obtain a sufficient effect, a relatively large amount of addition is required. Therefore, the dewatering property in the wire part and the water squeezing property in the press part are reduced, and the drying efficiency is reduced accordingly. Deterioration of
There is a problem such as slime generation due to fungi, and particularly when trying to increase the recovery rate of white water for the purpose of saving water and the like, starch is concentrated and becomes nutrient-rich, and the occurrence of slime due to fungi becomes a serious problem.

[0005]

In order to solve various problems associated with the addition of the positive starch such as the decrease in the drying efficiency, the deterioration of the drainage, the generation of slime, etc., the positive starch is not added to the raw material, Alternatively, even when it is added, it is necessary to secure sufficient fixing of the sizing agent and the yield of the filler while limiting the amount thereof. However, the reduction of the amount of the positive starch has resulted in the deterioration of the sizing property by impairing the fixing of the sizing agent.

[0006] That is, an object of the present invention is to provide a neutral paper having sufficient sizing property while adding no positive starch to the raw material or limiting the amount of the positive starch. .

[0007]

The present inventor has invented the neutral paper of the present invention as a result of intensive research. That is, the neutral paper of the present invention is a pulp slurry obtained by adding neutral rosin as a sizing agent and polyacrylamide containing a cyclic secondary amine as a functional group as a size fixing agent, and the addition amount of the polyacrylamide. But to pulp 0.05
% To 0.15% by weight, and the pulp slurry is used to make paper.

Further, it is characterized by containing a sulfuric acid band as an auxiliary agent of neutral rosin.

Further, the present invention is characterized in that the neutral rosin is an emulsion emulsified with an anionic protective colloid.

The neutral paper of the present invention will be described in detail below. In inventing the neutral paper of the present invention, even if the positive starch is removed or the amount thereof is reduced, the type of the sizing agent or the size fixing agent and its As a result of examining the combination, by adding neutral rosin as a sizing agent and adding a specific amount of polyacrylamide containing a cyclic secondary amine as a functional group as a size fixing agent, the positive starch was removed or reduced. However, it has been found that sufficient sizeability can be obtained without impairing the fixing of the sizing agent.

In the present invention, the amount of polyacrylamide containing a cyclic secondary amine as a functional group is 0.05 to 0.15% by weight based on the pulp. here,
If the addition amount is less than 0.05% by weight, sufficient effect of fixing the sizing agent cannot be obtained, and if it exceeds 0.15% by weight,
Not only the effect of fixing the sizing agent further than that is not obtained, but also the disintegration property at the time of collecting the broke is significantly deteriorated.

In the present invention, in order to effectively bring out the effect of the neutral rosin used as a sizing agent, it is preferable to add an appropriate amount of sulfate band.

In the present invention, the neutral rosin sizing agent is preferably an emulsion emulsified with an anionic protective colloid. When the neutral rosin is an emulsion emulsified with a cationic protective colloid, it has a self-fixing effect on the pulp slurry, and therefore polyacrylamide containing a cyclic secondary amine as a fixing agent as a functional group. Effect is hard to appear.

The neutral rosin sizing agent used in the present invention is disclosed in Japanese Examined Patent Publication No. 3-79480 and Japanese Unexamined Patent Publication No. 3-1081.
As disclosed in Japanese Patent Laid-Open No. 96-96, in weakly acidic to alkaline, by modifying a part or all of the rosin, which is difficult to express the size effect, etc., the size effect originally possessed by the rosin is not impaired, and its application range is The range is from weakly acidic to alkaline.

The polyacrylamide containing a cyclic secondary amine as a functional group used in the present invention means an inorganic or organic acid salt of secondary diallylamine and an acrylamide compound can be copolymerized with the secondary diallylamine salt and the acrylamide compound. Is a polymer compound obtained by copolymerization in the absence or presence of another polymerizable vinyl monomer.

The sulfuric acid band used in the present invention has conventionally been used for the purpose of fixing dyes, chemicals, etc., improving drainage in the wire part and dehydration property in the press part, adjusting pH, and preventing deposits. Widely used in papermaking systems. In the present invention, in addition to these effects, the main purpose is to promote the expression of the size effect of neutral rosin.

The pulp used for the neutral paper of the present invention includes NBKP, LBKP, NBSP, LBSP, CG.
P, TMP, GP, DIP, various non-wood pulp, etc. are mentioned.

The neutral paper of the present invention contains, if necessary, dyes, fillers, dry paper strengthening agents and the like, which are usually used in papermaking, and other sizing agents and fixing agents. further,
It is also possible to apply starch, polyvinyl alcohol or the like on the surface by a size press or the like. It is also possible to provide a coating layer on the surface if necessary, for the coating at that time, blade coating method, air knife coating method, bar coating method, curtain coating method, die coating method, gravure coating method Are used.

The neutral paper according to the present invention is used as a printing paper, a writing paper, a thin paper, a transfer paper for electrophotography, a thermal transfer image-receiving paper or the like which is used in an uncoated state, or a coated paper for printing, a thermal recording paper, It is used as a base paper for pressure-sensitive paper, inkjet paper, magnetic recording paper, etc.

[0020]

The neutral paper of the present invention to which a neutral rosin is added as a sizing agent and a specific amount of polyacrylamide containing a cyclic secondary amine as a functional group is added as a fixing agent is excellent in fixing of the sizing agent. , Sufficient size can be obtained.

[0021]

EXAMPLES The present invention will be described in detail below with reference to examples. The present invention is not limited to the examples.
All parts and% in the following are by weight.

Examples 1 to 3 Light calcium carbonate (Tamapearl 121, manufactured by Okutama Kogyo Co., Ltd.) per 100 parts of pulp mixed with LBKP and NBKP in a weight ratio of 85:15, beaten to a freeness of 300 ml.
Was added to 10 parts of polyacrylamide containing cyclic secondary amine as a functional group in an amount of 0.05
Parts, 0.1 parts, and 0.15 parts, sulfuric acid band 1.0
Part, neutral rosin sizing agent (KS-767, manufactured by Arakawa Chemical Co., Ltd.) was used in an orientation sheet former (Kumagaya Riki Kogyo Co., Ltd.) to obtain a basis weight of 50 to 50.
52 g / m ² neutral paper was produced. These samples were used as neutral papers of Example 1, Example 2, and Example 3 in order from the one having the smallest addition amount of polyacrylamide containing a cyclic secondary amine as a functional group.

Example 4 In Example 2, except that 0.5 part of a positive starch (Excel NO4, manufactured by Nitto Kagaku) was added before adding polyacrylamide containing a cyclic secondary amine as a functional group. A neutral paper was manufactured in the same manner as in Example 2.
This sample was used as the neutral paper of Example 4.

Example 5 A neutral paper was produced in the same manner as in Example 2, except that the sulfuric acid band was not added.
This sample was used as the neutral paper of Example 5.

Example 6 In Example 5, the neutral rosin sizing agent was changed to KS-767.
Neutral paper was manufactured in the same manner as in Example 5, except that New Size 770 (manufactured by Harima Kasei) was used instead of (Arakawa Chemical Co., Ltd.). This sample was used as the neutral paper of Example 6.

Example 7 In Example 2, the neutral rosin sizing agent was replaced with KS-767.
Neutral paper was produced in the same manner as in Example 2 except that Size Pine NTS (Arakawa Chemical Co., Ltd., cationic emulsion) was used instead of (Arakawa Chemical Co., Ltd., anionic emulsion). This sample was used as the neutral paper of Example 7.

Comparative Example 1 The same method as in Example 1 except that the amount of polyacrylamide containing a cyclic secondary amine as a functional group was changed to 0.05 part instead of 0.05 part. To produce neutral paper. This sample was used as the neutral paper of Comparative Example 1.

Comparative Example 2 The same method as in Example 1 except that the amount of polyacrylamide containing a cyclic secondary amine as a functional group in Example 1 was changed to 0.2 part instead of 0.05 part. To produce neutral paper. This sample was used as the neutral paper of Comparative Example 2.

Comparative Examples 3 to 5 In Example 1, positive starch (Excel N) was used instead of polyacrylamide containing a cyclic secondary amine as a functional group.
O4, manufactured by Nippon Starch Chemical Co., Ltd.) was used to produce a neutral paper in the same manner as in Example 1 except that 0.25 parts, 0.5 parts and 1.0 part were added. These samples were used as the neutral papers of Comparative Example 3, Comparative Example 4, and Comparative Example 5 in order from the one with the smallest addition amount of positive starch.

Comparative Example 6 In Example 1, polyacrylamide containing a cyclic secondary amine as a functional group was not added, and the neutral rosin sizing agent was replaced with KS-767 (Arakawa Chemical Co., Ltd., anionic emulsion). Example 1 except that the size pine NTS (Arakawa Chemical Co., Ltd., cationic emulsion) was used.
A neutral paper was produced in the same manner as in. This sample was used as the neutral paper of Comparative Example 6.

The above results are summarized in Table 1. In addition,
The degree of bump size is a value measured by the water absorption test method for paper and paperboard described in JIS-P-8140, with the contact time of water being 10 seconds. The required value of the degree of Cobb sizing varies depending on the amount of the sizing agent added and the degree of required sizing property, but in the examples and comparative examples of the present invention, it is preferably 25 g / m ² or more. .

[0032]

[Table 1]

[0033]

From the above results, the neutral paper of the present invention, which is produced by using the neutral rosin sizing agent and the specific polyacrylamide in the pulp slurry in combination, has sufficient sizing property and shows positive starch. It is possible to avoid various problems associated with the addition of.

Claims (3)

[Claims] 1. A pulp slurry obtained by adding a neutral rosin as a sizing agent and a polyacrylamide containing a cyclic secondary amine as a functional group as a size fixing agent, and the addition amount of the polyacrylamide is 0 relative to the pulp. .05
0.15% by weight, and a neutral paper obtained by making paper using the pulp slurry. 2. The neutral paper according to claim 1, which contains a sulfuric acid band as an auxiliary agent for the neutral rosin. 3. The neutral paper according to claim 1 or 2, wherein the neutral rosin is an emulsion emulsified with an anionic protective colloid.